WorldWideScience

Sample records for high spin slide

  1. Frictional coupling between sliding and spinning motion

    OpenAIRE

    Farkas, Zeno; Bartels, Guido; Unger, Tamas; Wolf, Dietrich E.

    2002-01-01

    We show that the friction force and torque, acting at a dry contact of two objects moving and rotating relative to each other, are inherently coupled. As a simple test system, a sliding and spinning disk on a horizontal flat surface is considered. We calculate, and also measure, how the disk is slowing down, and find that it always stops its sliding and spinning motion at the same moment. We discuss the impact of this coupling between friction force and torque on the physics of granular mater...

  2. High spin states in Cu

    Indian Academy of Sciences (India)

    up of high-spin configurations outlined above, a detailed and careful study of the medium spin, near yrast states in this nucleus is important for reliable assignments of spins and parities to states in superdeformed bands [1,6] in mass region 60. Also, the observation of direct proton decay from excited states in Cu nuclei [14] ...

  3. Observer-based adaptive sliding mode backstepping output-feedback DSC for spin-stabilized canard-controlled projectiles

    Directory of Open Access Journals (Sweden)

    Yuanchuan SHEN

    2017-06-01

    Full Text Available This article presents a complete nonlinear controller design for a class of spin-stabilized canard-controlled projectiles. Uniformly ultimate boundedness and tracking are achieved, exploiting a heavily coupled, bounded uncertain and highly nonlinear model of longitudinal and lateral dynamics. In order to estimate unmeasurable states, an observer is proposed for an augmented multiple-input-multiple-output (MIMO nonlinear system with an adaptive sliding mode term against the disturbances. Under the frame of a backstepping design, an adaptive sliding mode output-feedback dynamic surface control (DSC approach is derived recursively by virtue of the estimated states. The DSC technique is adopted to overcome the problem of “explosion of complexity” and relieve the stress of the guidance loop. It is proven that all signals of the MIMO closed-loop system, including the observer and controller, are uniformly ultimately bounded, and the tracking errors converge to an arbitrarily small neighborhood of the origin. Simulation results for the observer and controller are provided to illustrate the feasibility and effectiveness of the proposed approach.

  4. High-spin nuclear spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Diamond, R.M.

    1986-07-01

    High-spin spectroscopy is the study of the changes in nuclear structure, properties, and behavior with increasing angular momentum. It involves the complex interplay between collective and single-particle motion, between shape and deformation changes, particle alignments, and changes in the pairing correlations. A review of progress in theory, experimentation, and instrumentation in this field is given. (DWL)

  5. A high performance switching audio amplifier using sliding mode control

    OpenAIRE

    Pillonnet, Gael; Cellier, Rémy; Abouchi, Nacer; Chiollaz, Monique

    2008-01-01

    International audience; The switching audio amplifiers are widely used in various portable and consumer electronics due to their high efficiency, but suffers from low audio performances due to inherent nonlinearity. This paper presents an integrated class D audio amplifier with low consumption and high audio performances. It includes a power stage and an efficient control based on sliding mode technique. This monolithic class D amplifier is capable of delivering up to 1W into 8Ω load at less ...

  6. High-field spin dynamics of antiferromagnetic quantum spin chains

    DEFF Research Database (Denmark)

    Enderle, M.; Regnault, L.P.; Broholm, C.

    2000-01-01

    The characteristic internal order of macroscopic quantum ground states in one-dimensional spin systems is usually not directly accessible, but reflected in the spin dynamics and the field dependence of the magnetic excitations. In high magnetic fields quantum phase transitions are expected. We...... present recent work on the high-field spin dynamics of the S = I antiferromagnetic Heisenberg chains NENP (Haldane ground state) and CsNiCl3 (quasi-1D HAF close to the quantum critical point), the uniform S = 1/2 chain CTS, and the spin-Peierls system CuGeO3. (C) 2000 Elsevier Science B,V. All rights...

  7. A high-temperature quantum spin liquid with polaron spins

    Science.gov (United States)

    Klanjšek, Martin; Zorko, Andrej; Žitko, Rok; Mravlje, Jernej; Jagličić, Zvonko; Biswas, Pabitra Kumar; Prelovšek, Peter; Mihailovic, Dragan; Arčon, Denis

    2017-11-01

    The existence of a quantum spin liquid (QSL) in which quantum fluctuations of spins are sufficiently strong to preclude spin ordering down to zero temperature was originally proposed theoretically more than 40 years ago, but its experimental realization turned out to be very elusive. Here we report on an almost ideal spin liquid state that appears to be realized by atomic-cluster spins on the triangular lattice of a charge-density wave state of 1T-TaS2. In this system, the charge excitations have a well-defined gap of ~0.3 eV, while nuclear quadrupole resonance and muon-spin-relaxation experiments reveal that the spins show gapless QSL dynamics and no long-range magnetic order at least down to 70 mK. Canonical T2 power-law temperature dependence of the spin relaxation dynamics characteristic of a QSL is observed from 200 K to Tf = 55 K. Below this temperature, we observe a new gapless state with reduced density of spin excitations and high degree of local disorder signifying new quantum spin order emerging from the QSL.

  8. Slide 1

    Indian Academy of Sciences (India)

    Click here to start. Table of contents. Slide 1 · Slide 2 · Slide 3 · Slide 4 · Slide 5 · Slide 6 · Slide 7 · Slide 8 · Slide 9 · Slide 10 · Slide 11 · Slide 12 · Slide 13 · Slide 14 · Slide 15 · Slide 16 · Slide 17.

  9. High spin isomer beam line at RIKEN

    Energy Technology Data Exchange (ETDEWEB)

    Kishida, T.; Ideguchi, E.; Wu, H.Y. [Institute of Physical and Chemical Research, Saitama (Japan)] [and others

    1996-12-31

    Nuclear high spin states have been the subject of extensive experimental and theoretical studies. For the production of high spin states, fusion reactions are usually used. The orbital angular momentum brought in the reaction is changed into the nuclear spin of the compound nucleus. However, the maximum induced angular momentum is limited in this mechanism by the maximum impact parameter of the fusion reaction and by the competition with fission reactions. It is, therefore, difficult to populate very high spin states, and as a result, large {gamma}-detector arrays have been developed in order to detect subtle signals from such very high spin states. The use of high spin isomers in the fusion reactions can break this limitation because the high spin isomers have their intrinsic angular momentum, which can bring the additional angular momentum without increasing the excitation energy. There are two methods to use the high spin isomers for secondary reactions: the use of the high spin isomers as a target and that as a beam. A high spin isomer target has already been developed and used for several experiments. But this method has an inevitable shortcoming that only {open_quotes}long-lived{close_quotes} isomers can be used for a target: {sup 178}Hf{sup m2} (16{sup +}) with a half-life of 31 years in the present case. By developing a high spin isomer beam, the authors can utilize various short-lived isomers with a short half-life around 1 {mu}s. The high spin isomer beam line of RIKEN Accelerator Facility is a unique apparatus in the world which provides a high spin isomer as a secondary beam. The combination of fusion-evaporation reaction and inverse kinematics are used to produce high spin isomer beams; in particular, the adoption of `inverse kinematics` is essential to use short-lived isomers as a beam.

  10. Slide 1

    Indian Academy of Sciences (India)

    Slide 5 · Slide 6 · Slide 7 · Immunology of VL · Slide 9 · Slide 10 · Slide 11 · Slide 12 · Slide 13 · Slide 14 · Strategies To Design Drugs · Slide 16 · Slide 17 · Slide 18 · Slide 19 · Slide 20 · Slide 21 · Slide 22 · Slide 23 · Slide 24 · Slide 25 · Slide 26 · Slide 27 · Slide 28 · Slide 29 · Slide 30 · Slide 31 · Slide 32 · Slide 33 · Slide 34.

  11. Slide 1

    Indian Academy of Sciences (India)

    Gene Expression in Eukaryotic Cells · Slide 3 · Slide 4 · Slide 5 · Slide 6 · Slide 7 · Slide 8 · Slide 9 · Slide 10 · Slide 11 · Slide 12 · Slide 13 · Slide 14 · Slide 15 · Slide 16 · Slide 17 · Slide 18 · Slide 19 · Slide 20 · Slide 21 · Slide 22 · Slide 23 · Slide 24 · Slide 25 · Slide 26 · Slide 27 · Slide 28 · Slide 29. Author: Office.

  12. Slide 1

    Indian Academy of Sciences (India)

    Slide 5 · Slide 6 · Second Question How Did this Shift in ToT Come About? Slide 8 · Second Question How Did this Shift in ToT Come About? Slide 10 · Slide 11 · Slide 12 · Slide 13 · Slide 14 · Slide 15 · Slide 17 · Slide 20 · Slide 21 · Slide 22 · Slide 23 · Slide 24 · Slide 25 · Slide 26 · Slide 27 · Slide 30 · India's Globalization.

  13. An Ultra-High Speed Whole Slide Image Viewing System

    Directory of Open Access Journals (Sweden)

    Yukako Yagi

    2012-01-01

    Full Text Available Background: One of the goals for a Whole Slide Imaging (WSI system is implementation in the clinical practice of pathology. One of the unresolved problems in accomplishing this goal is the speed of the entire process, i.e., from viewing the slides through making the final diagnosis. Most users are not satisfied with the correct viewing speeds of available systems. We have evaluated a new WSI viewing station and tool that focuses on speed.

  14. High-Order Sliding Mode Control for DFIG-Based Wind Turbine Fault Ride-Through

    OpenAIRE

    Benbouzid, Mohamed; Beltran, Brice; Amirat, Yassine; Gang, Yao; Jingang, Han; Mangel, Hervé

    2013-01-01

    International audience; This paper deals with the Fault Ride-Through (FRT) capability assessment of a Doubly-Fed Induction Generator (DFIG)-based Wind Turbine (WT) using High-Order Sliding Mode (HOSM) control. Indeed, it has been recently suggested that sliding mode control is a solution of choice to the FRT problem. In this context, this paper proposes HOSM as an improved solution that handle the classical sliding mode chattering problem. Indeed, the main and attractive features of HOSMs are...

  15. High spin properties of Ba

    Indian Academy of Sciences (India)

    Abstract. The 124Ba nucleus is investigated on the basis of the method of statistical mechanics by assuming the nucleons to move in triaxially deformed Nilsson potential. The variation in the Fermi energies of protons and neutrons is studied as a function of spin and temperature. The Fermi energies determined as a function ...

  16. Sliding Malar Bone Augmentation Technique with a High Le Fort I ...

    African Journals Online (AJOL)

    2017-05-16

    May 16, 2017 ... osteotomy design, including the malar bones, which allows segment sliding over the zygoma and forces the osteotomized ... Sliding Malar Bone Augmentation Technique with a High Le Fort I. Surgically Assisted Rapid Maxillary Expansion .... or Crouzon syndrome.[19] Kim et al.'s study investigating.

  17. Slide 1

    Indian Academy of Sciences (India)

    Slide 25 · Life course epidemiology and chronic diseases · Models · Slide 28 · Slide 29 · Slide 30 · New Delhi Birth Cohort · New Delhi Birth Cohort (NDBC) · Slide 33 · Slide 34 · Slide 35 · Slide 36 · Slide 37 · Slide 38 · Slide 39 · CONCLUSIONS Urban Children and Adolescents · CONCLUSIONS New Delhi Birth Cohort.

  18. High-Spin Cobalt Hydrides for Catalysis

    Energy Technology Data Exchange (ETDEWEB)

    Holland, Patrick L. [Univ. of Rochester, NY (United States)

    2013-08-29

    Organometallic chemists have traditionally used catalysts with strong-field ligands that give low-spin complexes. However, complexes with a weak ligand field have weaker bonds and lower barriers to geometric changes, suggesting that they may lead to more rapid catalytic reactions. Developing our understanding of high-spin complexes requires the use of a broader range of spectroscopic techniques, but has the promise of changing the mechanism and/or selectivity of known catalytic reactions. These changes may enable the more efficient utilization of chemical resources. A special advantage of cobalt and iron catalysts is that the metals are more abundant and cheaper than those currently used for major industrial processes that convert unsaturated organic molecules and biofeedstocks into useful chemicals. This project specifically evaluated the potential of high-spin cobalt complexes for small-molecule reactions for bond rearrangement and cleavage reactions relevant to hydrocarbon transformations. We have learned that many of these reactions proceed through crossing to different spin states: for example, high-spin complexes can flip one electron spin to access a lower-energy reaction pathway for beta-hydride elimination. This reaction enables new, selective olefin isomerization catalysis. The high-spin cobalt complexes also cleave the C-O bond of CO2 and the C-F bonds of fluoroarenes. In each case, the detailed mechanism of the reaction has been determined. Importantly, we have discovered that the cobalt catalysts described here give distinctive selectivities that are better than known catalysts. These selectivities come from a synergy between supporting ligand design and electronic control of the spin-state crossing in the reactions.

  19. Spinnability Investigation of High Strength Steel in Draw-spinning and Flow-spinning

    Science.gov (United States)

    Shi, L.; Xiao, H.; Xu, D. K.

    2017-09-01

    High strength steels are difficult to process in spinning due to their high yield and tensile strength, poor ductility and large springback. In this paper, formability of dual phase steel has been investigated on the basis of spinnability evaluation in draw-spinning and flow-spinning processes. The influences of key process parameters such as feed ratio and wheel fillet radius on forming limit coefficient in draw-spinning and maximum thinning ratio in flow-spinning are studied in detail.

  20. Spin structure in high energy processes

    Science.gov (United States)

    Deporcel, L.; Dunwoodie, C.

    1994-12-01

    This report contains papers of the following topics: Spin, Mass, and Symmetry; physics with polarized Z(sup 0)s; spin and precision electroweak physics; polarized electron sources; polarization phenomena in quantum chromodynamics; polarized lepton-nucleon scattering; polarized targets in high energy physics; spin dynamics in storage rings and linear accelerators; spin formalism and applications to new physics searches; precision electroweak physics at LEP; recent results on heavy flavor physics from LEP experiments using 1990--1992 data; precise measurement of the left-right cross section asymmetry in Z boson production by electron-positron collisions; preliminary results on heavy flavor physics at SLD; QCD tests with SLD and polarized beams; recent results from TRISTAN at KEK; recent B physics results from CLEO; searching for the H dibaryon at Brookhaven; recent results from the compton observatory; the spin structure of the deuteron; spin structure of the neutron ((sup 3)HE) and the Bjoerken sum rule; a consumer's guide to lattice QCD results; top ten models constrained by b yields sy; a review of the Fermilab fixed target program; results from the D0 experiment; results from CDF at FNAL; quantum-mechanical suppression of bremsstrahlung; report from the ZEUS collaboration at HERA; physics from the first year of H1 at HERA, and hard diffraction. These papers have been cataloged separately elsewhere.

  1. Spin structure in high energy processes: Proceedings

    Energy Technology Data Exchange (ETDEWEB)

    DePorcel, L.; Dunwoodie, C. [eds.

    1994-12-01

    This report contains papers as the following topics: Spin, Mass, and Symmetry; physics with polarized Z{sup 0}s; spin and precision electroweak physics; polarized electron sources; polarization phenomena in quantum chromodynamics; polarized lepton-nucleon scattering; polarized targets in high energy physics; spin dynamics in storage rings and linear accelerators; spin formalism and applications to new physics searches; precision electroweak physics at LEP; recent results on heavy flavor physics from LEP experiments using 1990--1992 data; precise measurement of the left-right cross section asymmetry in Z boson production by electron-positron collisions; preliminary results on heavy flavor physics at SLD; QCD tests with SLD and polarized beams; recent results from TRISTAN at KEK; recent B physics results from CLEO; searching for the H dibaryon at Brookhaven; recent results from the compton observatory; the spin structure of the deuteron; spin structure of the neutron ({sup 3}HE) and the Bjoerken sum rule; a consumer`s guide to lattice QCD results; top ten models constrained by b {yields} sy; a review of the Fermilab fixed target program; results from the D0 experiment; results from CDF at FNAL; quantum-mechanical suppression of bremsstrahlung; report from the ZEUS collaboration at HERA; physics from the first year of H1 at HERA, and hard diffraction. These papers have been cataloged separately elsewhere.

  2. Insights from new high-resolution data from the Traenadjupet Slide on the Norwegian margin

    Science.gov (United States)

    Mozzato, Alessandro; Tappin, David; Talling, Peter; Cartigny, Matthieu; Long, David; Hunt, James; Watts, Camilla; Pope, Ed; Allin, Joshua; Stanford, Jennifer; Dowdeswell, Julian

    2015-04-01

    Submarine landslides are among the largest mass flows on Earth and can be far larger than landslides on land. They can generate tsunami and therefore represent a significant geohazard. A series of large submarine landslides have been studied previously in unusual detail along the Norwegian continental margin, including the Storegga and Traenadjupet Slides. The most closely studied is the Storegga slide(1,2) which occurred 8.2k BP and moved >3,000 km3 of sediment(2). A tsunami with run up heights sometimes reaching 20m high has been identified from deposits mapped along the Norwegian, Shetland and mainland Scottish coasts (1). The Traenadjupet Slide is the second largest slide on the Norwegian margin with a volume of about 900km3. It has been dated to ~4k BP(3,4). The volume is comparable to that of the Storegga Slide. However, no major tsunami deposit at 4ka has yet been mapped that links to the Traenadjupet Slide (Stein Bondevik, pers. comm.). The purpose of this study is to obtain new insights into how the Traenadjupet Slide was emplaced. In particular, why did movement of 900km3 of sediment during the Traenadjupet Slide fail to produce a major tsunami at 4ka? We present a new field dataset for the Traendajupet Slide including MBES bathymetry, sub-bottom profiles, and piston cores acquired during the 64PE391 research expedition in July 2014, together with data acquired previously during the JCR51 cruise. These datasets cover a large part of Traenadjupet slide and give new insights into the mechanism of the slide failure. The Traenadjupet Slide morphology is very different to that of the Storegga Slide. The Storegga Slide disintegrated generating debris flows and turbidity currents that propagated for hundreds of kilometres. The Traenadjupet Slide, on the other hand, appears not to have disintegrated in a similar manner, but rather left thick mounded deposits at the foot of the slope(5). Several distinct lobes covered with 500m-scale sediment blocks are visible

  3. High resolution spin- and angle-resolved photoelectron spectroscopy for 3D spin vectorial analysis

    Science.gov (United States)

    Okuda, Taichi; Miyamoto, Koji; Kimura, Akio; Namatame, Hirofumi; Taniguchi, Masaki

    2013-03-01

    Spin- and angle-resolved photoelectron spectroscopy (SARPES) is the excellent tool which can directly observe the band structure of crystals with separating spin-up and -down states. Recent findings of new class of materials possessing strong spin orbit interaction such as Rashba spin splitting systems or topological insulators stimulate to develop new SARPES apparatuses and many sophisticated techniques have been reported recently. Here we report our newly developed a SARPES apparatus for spin vectorial analysis with high precision at Hiroshima Synchrotron Radiation Center. Highly efficient spin polarimeter utilizing very low energy electron diffraction (VLEED) makes high resolution (ΔE Japan Society for the Promotion of Science.

  4. High spin spectroscopy of 139 Pr

    Indian Academy of Sciences (India)

    Home; Journals; Pramana – Journal of Physics; Volume 57; Issue 1. High spin spectroscopy of 139Pr. S Chanda Sarmishtha Bhattacharyya Tumpa Bhattacharjee S S Ghugre Swapan Kumar Basu S Muralithar R P Singh B Mukherjee R K Bhowmik S N Ray. Contributed Papers : Nuclear spectroscopy Volume 57 Issue 1 July ...

  5. High spin rotational bands in Zn

    Indian Academy of Sciences (India)

    July 2001 physics pp. 181–184. High spin rotational bands in. 65. Zn. B MUKHERJEE, S MURALITHAR, R P SINGH, R KUMAR, K RANI and. R K BHOWMIK. Nuclear Science Centre, Aruna Asaf Ali Marg, P.B. No. .... resolved due to poor resolution of the detectors used. The measured DCO ratios for the 835,. 988, 1074 ...

  6. Nuclear structure of Ra at high spin

    Indian Academy of Sciences (India)

    However, nuclear structure at high spin and excitation energies (∼ 6 MeV) would require a coupling of excited 1p–1h with 208Pb core. The coupling between single- particle orbitals and collective vibrations of core complicates the simple shell model picture. With increasing neutron number, Ra isotopes show an abrupt ...

  7. Slide 1

    Indian Academy of Sciences (India)

    Natural Disasters & Floods · Slide 6 · Slide 7 · Slide 8 · Slide 9 · Slide 10 · Indira Gandhi Canal in Rajasthan · Slide 12 · Epidemic Strains · Parasite strains in India · Questions · Slide 16 · Slide 17 · Slide 18 · Slide 19 · Slide 20 · Plasmodium falciparum CQ RESISTANCE TRANSPORTER PROTEIN (PfCRT) · pfcrt mutations.

  8. Spin Transport in High-Quality Suspended Graphene Devices

    NARCIS (Netherlands)

    Guimaraes, Marcos H. D.; Veligura, A.; Zomer, P. J.; Maassen, T.; Vera-Marun, I. J.; Tombros, N.; van Arees, B. J.; Wees, B.J. van

    We measure spin transport in high mobility suspended graphene (mu approximate to 10(5)cm(2)/(V s)), obtaining a (spin) diffusion coefficient of 0.1 m(2)/s and giving a lower bound on the spin relaxation time (tau(s) approximate to 150 ps) and spin relaxation length (lambda(s) = 4.7 mu m) for

  9. Strontium Oxide Tunnel Barriers for High Quality Spin Transport and Large Spin Accumulation in Graphene.

    Science.gov (United States)

    Singh, Simranjeet; Katoch, Jyoti; Zhu, Tiancong; Wu, Ryan J; Ahmed, Adam S; Amamou, Walid; Wang, Dongying; Mkhoyan, K Andre; Kawakami, Roland K

    2017-11-16

    The quality of the tunnel barrier at the ferromagnet/graphene interface plays a pivotal role in graphene spin valves by circumventing the impedance mismatch problem, decreasing interfacial spin dephasing mechanisms and decreasing spin absorption back into the ferromagnet. It is thus crucial to integrate superior tunnel barriers to enhance spin transport and spin accumulation in graphene. Here, we employ a novel tunnel barrier, strontium oxide (SrO), onto graphene to realize high quality spin transport as evidenced by room-temperature spin relaxation times exceeding a nanosecond in graphene on silicon dioxide substrates. Furthermore, the smooth and pinhole-free SrO tunnel barrier grown by molecular beam epitaxy (MBE), which can withstand large charge injection current densities, allows us to experimentally realize large spin accumulation in graphene at room temperature. This work puts graphene on the path to achieve efficient manipulation of nanomagnet magnetization using spin currents in graphene for logic and memory applications.

  10. High spin ↔ low spin ultrafast excitation and relaxation of an isolated iron(II complex.

    Directory of Open Access Journals (Sweden)

    Létard J.F.

    2013-03-01

    Full Text Available Picosecond and femtosecond time resolved pump-probe experiments make it possible to study both the low spin (LS to high spin (HS and high spin to low spin excitation and relaxation processes in the same isolated iron(II complex. We demonstrate that both LS → HS and HS → LS can be recorded by changing the pump wavelength and occur on the same time scale.

  11. High-spin structure in 40K

    Science.gov (United States)

    Söderström, P.-A.; Recchia, F.; Nyberg, J.; Gadea, A.; Lenzi, S. M.; Poves, A.; Ataç, A.; Aydin, S.; Bazzacco, D.; Bednarczyk, P.; Bellato, M.; Birkenbach, B.; Bortolato, D.; Boston, A. J.; Boston, H. C.; Bruyneel, B.; Bucurescu, D.; Calore, E.; Cederwall, B.; Charles, L.; Chavas, J.; Colosimo, S.; Crespi, F. C. L.; Cullen, D. M.; de Angelis, G.; Désesquelles, P.; Dosme, N.; Duchêne, G.; Eberth, J.; Farnea, E.; Filmer, F.; Görgen, A.; Gottardo, A.; Grębosz, J.; Gulmini, M.; Hess, H.; Hughes, T. A.; Jaworski, G.; Jolie, J.; Joshi, P.; Judson, D. S.; Jungclaus, A.; Karkour, N.; Karolak, M.; Kempley, R. S.; Khaplanov, A.; Korten, W.; Ljungvall, J.; Lunardi, S.; Maj, A.; Maron, G.; Męczyński, W.; Menegazzo, R.; Mengoni, D.; Michelagnoli, C.; Molini, P.; Napoli, D. R.; Nolan, P. J.; Norman, M.; Obertelli, A.; Podolyak, Zs.; Pullia, A.; Quintana, B.; Redon, N.; Regan, P. H.; Reiter, P.; Robinson, A. P.; Şahin, E.; Simpson, J.; Salsac, M. D.; Smith, J. F.; Stézowski, O.; Theisen, Ch.; Tonev, D.; Unsworth, C.; Ur, C. A.; Valiente-Dobón, J. J.; Wiens, A.

    2012-11-01

    High-spin states of 40K have been populated in the fusion-evaporation reaction 12C(30Si,np)40K and studied by means of γ-ray spectroscopy techniques using one triple-cluster detector of the Advanced Gamma Tracking Array at the Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali di Legnaro. Several states with excitation energy up to 8 MeV and spin up to 10- have been discovered. These states are discussed in terms of J=3 and T=0 neutron-proton hole pairs. Shell-model calculations in a large model space have shown good agreement with the experimental data for most of the energy levels. The evolution of the structure of this nucleus is here studied as a function of excitation energy and angular momentum.

  12. 16th Workshop on High Energy Spin Physics

    CERN Document Server

    2016-01-01

    The Workshop will cover a wide range of spin phenomena at high and intermediate energies such as: recent experimental data on spin physics the nucleon spin structure and GPD's spin physics and QCD spin physics in the Standard Model and beyond T-odd spin effects polarization and heavy ion physics spin in gravity and astrophysics the future spin physics facilities spin physics at NICA polarimeters for high energy polarized beams acceleration and storage of polarized beams the new polarization technology related subjects The Workshop will be held in the Bogoliubov Laboratory of Theoretical Physics of the Joint Institute for Nuclear Research, 141980 Dubna, Moscow Region, Russia. The program of the workshop will include plenary and parallel (if necessary) sessions. Plenary sessions will be held in the Conference Hall. Parallel sections will take place in the same building. There will be invited talks (up to 40 min) and original reports (20 min). The invited speakers will present new experimental and theoretical re...

  13. Novel method for the high-throughput processing of slides for the comet assay.

    Science.gov (United States)

    Karbaschi, Mahsa; Cooke, Marcus S

    2014-11-26

    Single cell gel electrophoresis (the comet assay), continues to gain popularity as a means of assessing DNA damage. However, the assay's low sample throughput and laborious sample workup procedure are limiting factors to its application. "Scoring", or individually determining DNA damage levels in 50 cells per treatment, is time-consuming, but with the advent of high-throughput scoring, the limitation is now the ability to process significant numbers of comet slides. We have developed a novel method by which multiple slides may be manipulated, and undergo electrophoresis, in batches of 25 rather than individually and, importantly, retains the use of standard microscope comet slides, which are the assay convention. This decreases assay time by 60%, and benefits from an electrophoresis tank with a substantially smaller footprint, and more uniform orientation of gels during electrophoresis. Our high-throughput variant of the comet assay greatly increases the number of samples analysed, decreases assay time, number of individual slide manipulations, reagent requirements and risk of damage to slides. The compact nature of the electrophoresis tank is of particular benefit to laboratories where bench space is at a premium. This novel approach is a significant advance on the current comet assay procedure.

  14. High Order Sliding Mode Control of Doubly-fed Induction Generator under Unbalanced Grid Faults

    DEFF Research Database (Denmark)

    Zhu, Rongwu; Chen, Zhe; Wu, Xiaojie

    2013-01-01

    This paper deals with a doubly-fed induction generator-based (DFIG) wind turbine system under grid fault conditions such as: unbalanced grid voltage, three-phase grid fault, using a high order sliding mode control (SMC). A second order sliding mode controller, which is robust with respect...... to matched internal or external disturbances, fast transient response and finite reaching time, is employed to reduce chattering phenomenon caused by high frequency switching of SMC, which serious exists in lower order SMC, and to overcome parameter dependence of traditional proportional integral (PI...

  15. Slide 1

    Indian Academy of Sciences (India)

    Potency of Stem Cells · Slide 3 · Slide 4 · Slide 5 · World Wide Clinical trials using MSCs · Slide 7 · Bone Marrow derived Human MSCs (hMSC) in culture · Slide 9 · Slide 10 · Slide 11 · Slide 12 · Slide 13 · Fetal MSCs · Morphology of murine fetal heart derived stem cells (fHSCs) · Growth Kinetics of fHSCs · Phenotype of ...

  16. Sliding malar bone augmentation technique with a high le fort I ...

    African Journals Online (AJOL)

    The purpose of this report is to evaluate the effectiveness of a high Le Fort I osteotomy design, including the malar bones, which allows segment sliding over the zygoma and forces the osteotomized segment to move forward with distraction. Two patients (male, 23- and 30-year-old) with malar deficiency underwent high Le ...

  17. Avoidance High-Frequency Chattering Second-Order Sliding Mode Controller Design: Buck Converter in Wind Power System

    Directory of Open Access Journals (Sweden)

    Yigeng Huangfu

    2012-01-01

    Full Text Available This paper mainly discussed a method of high-frequency second-order sliding mode control for Buck converter in wind power systems. Because the wind energy of nature is always unpredictable and intermittent, the robust control such as sliding mode control is adopted in past literatures. In order to remove the high frequency chattering problem when the traditional sliding mode achieves convergence, the second order sliding mode algorithm is reviewed firstly. Meanwhile, the Buck converter taken as a step-down converter is usually adopted in wind power system, because of its simple structure and good linearity. Under those conditions, the second order sliding mode controller is designed based on Buck converter, especially in high-power wind generation system. The experimental results illustrate that the theory of second order sliding mode can be used in high-power Buck converter. It provides one novel avoidance high frequency chattering method for the technology development of new energy generation system.

  18. High spin-filter efficiency and Seebeck effect through spin-crossover iron-benzene complex.

    Science.gov (United States)

    Yan, Qiang; Zhou, Liping; Cheng, Jue-Fei; Wen, Zhongqian; Han, Qin; Wang, Xue-Feng

    2016-04-21

    Electronic structures and coherent quantum transport properties are explored for spin-crossover molecule iron-benzene Fe(Bz)2 using density functional theory combined with non-equilibrium Green's function. High- and low-spin states are investigated for two different lead-molecule junctions. It is found that the asymmetrical T-shaped contact junction in the high-spin state behaves as an efficient spin filter while it has a smaller conductivity than that in the low-spin state. Large spin Seebeck effect is also observed in asymmetrical T-shaped junction. Spin-polarized properties are absent in the symmetrical H-shaped junction. These findings strongly suggest that both the electronic and contact configurations play significant roles in molecular devices and metal-benzene complexes are promising materials for spintronics and thermo-spintronics.

  19. High order sliding mode control of a DFIM supplied by two power inverters

    Directory of Open Access Journals (Sweden)

    Zinelaabidine Boudjema

    2015-06-01

    Full Text Available Traditional vector control structures which include proportional-integral (PI regulator for the speed of a doubly fed induction motor (DFIM driven have some disadvantages such as parameter tuning complications, mediocre dynamic performances and reduced robustness. Thus, based on the analysis of the mathematical model of a DFIM supplied by two indirect inverters, this paper addresses a nonlinear control algorithm based on high order sliding mode. The conventional sliding mode control has large chattering on the electromagnetic torque developed by the DFIM. In order to solve this problem, the second order sliding mode technique is used. The simulation results show the effectiveness of the proposed method especially in chattering-free behavior, response to sudden load torque variations and robustness against machine parameters variations.

  20. Failure mechanism of coated biomaterials under high impact-sliding contact stresses

    Science.gov (United States)

    Chen, Ying

    This study uses a newly developed testing method--- inclined cyclic impact-sliding test to investigate the failure behaviors of different types of biomaterials, (SS316L, Ti6Al4V and CoCr) coated by different coatings (TiN, DLC and PEO), under extremely high dynamic contact stress conditions. This test method can simulate the combined impact and sliding/rolling loading conditions, which is very practical in many aspects of commercial usages. During the tests, fatigue cracking, chipping, peeling and material transferring were observed in damaged area. This research is mainly focused on the failure behaviors of load-bearing materials which cyclic impacting and sliding are always involved. This purpose was accomplished in the three stages: First, impact-sliding test was carried out on TiN coated unhardened M2. It was found that soft substrate can cause early failure of coating due to the considerable plastic deformation in the substrate. In this case, stronger substrate is required to support coating better when tested under high contact stresses. Second, PEO coated Ti-6Al-4V was tested under pure sliding and impact-sliding wear conditions. PEO coating was found not strong enough to afford the high contact pressure under cyclic impact-sliding wear test due to its porous surface structure. However, the wear performance of PEO coating was enhanced due to the sub-stoichiometric oxide. To sum up, for load-bearing biomedical implants involved in high impacting movement, PEO coating may not be a promising surface protection. Third, the dense, smooth PVD/CVD bio-inert coatings were reconsidered. DLC and TiN coatings, combined by different substrates together with different interface materials were tested under the cyclic impact-sliding test using a set of proper loading. The results show that to choose a proper combination of coating, interface and substrate based on their mechanical properties is of great importance under the test condition. Hard substrates provide support

  1. Investigation of transient temperature's influence on damage of high-speed sliding electrical contact rail surface

    Science.gov (United States)

    Zhang, Yuyan; Sun, Shasha; Guo, Quanli; Yang, Degong; Sun, Dongtao

    2016-11-01

    In the high speed sliding electrical contact with large current, the temperature of contact area rises quickly under the coupling action of the friction heating, the Joule heating and electric arc heating. The rising temperature seriously affects the conductivity of the components and the yield strength of materials, as well affects the contact state and lead to damage, so as to shorten the service life of the contact elements. Therefore, there is vital significance to measure the temperature accurately and investigate the temperature effect on damage of rail surface. Aiming at the problem of components damage in high speed sliding electrical contact, the transient heat effect on the contact surface was explored and its influence and regularity on the sliding components damage was obtained. A kind of real-time temperature measurement method on rail surface of high speed sliding electrical contact is proposed. Under the condition of 2.5 kA current load, based on the principle of infrared radiation non-contact temperature sensor was used to measure the rail temperature. The dynamic distribution of temperature field was obtained through the simulation analysis, further, the connection between temperature changes and the rail surface damage morphology, the damage volume was analyzed and established. Finally, the method to reduce rail damage and improve the life of components by changing the temperature field was discussed.

  2. Application of strength reduction method to dynamic anti-sliding stability analysis of high gravity dam with complex dam foundation

    OpenAIRE

    Deng-hong Chen; Cheng-bin Du

    2011-01-01

    Considering that there are some limitations in analyzing the anti-sliding seismic stability of dam-foundation systems with the traditional pseudo-static method and response spectrum method, the dynamic strength reduction method was used to study the deep anti-sliding stability of a high gravity dam with a complex dam foundation in response to strong earthquake-induced ground action. Based on static anti-sliding stability analysis of the dam foundation undertaken by decreasing the shear streng...

  3. Dynamics of High-Speed Rotors Supported in Sliding Bearings

    Science.gov (United States)

    Šimek, J.; Svoboda, R.

    The higher the operating speed, the more serious are problems with rotor stability. Three basic groups of rotors are analyzed and some methods of suppressing instability are shown. In the first group are classical elastic rotors supported in hydrodynamic bearings. Practically all high-speed rotors now run in tilting pad bearings, which are inherently stable, but in specific conditions even tiling pad bearings may not ensure rotor stability. The second group is composed of combustion engines turbocharger rotors, which are characteristic by heavy impellers at both overhung ends of elastic shaft. These rotors are in most cases supported in floating ring bearings, which bring special features to rotor behaviour. The third group of rotors with gas bearings exhibits special features.

  4. High spins in gamma-soft nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Leander, G.A.; Frauendorf, S.; May, F.R.

    1982-01-01

    Nuclei which are soft with respect to the ..gamma.. shape degree of freedom are expected to have many different structures coexisting in the near-yrast regime. In particular, the lowest rotational quasi-particle in a high-j shell exerts a strong polarizing effect on ..gamma... The ..gamma.. to which it drives is found to vary smoothly over a 180/sup 0/ range as the position of the Fermi level varies. This simple rule is seen to have a direct connection with the energy staggering of alternate spin states in rotational bands. A diagram is presented which provides a general theoretical reference for experimental tests of the relation between ..gamma.., spin staggering, configuration, and nucleon number. In a quasicontinuum spectrum, the coexistence of different structures are expected to make several unrelated features appear within any one slice of sum energy and multiplicity. However, it is also seen that the in-band moment of inertia may be similar for many bands of different ..gamma...

  5. Sliding-Mode Control Applied for Robust Control of a Highly Unstable Aircraft

    Science.gov (United States)

    Vetter, Travis Kenneth

    2002-01-01

    An investigation into the application of an observer based sliding mode controller for robust control of a highly unstable aircraft and methods of compensating for actuator dynamics is performed. After a brief overview of some reconfigurable controllers, sliding mode control (SMC) is selected because of its invariance properties and lack of need for parameter identification. SMC is reviewed and issues with parasitic dynamics, which cause system instability, are addressed. Utilizing sliding manifold boundary layers, the nonlinear control is converted to a linear control and sliding manifold design is performed in the frequency domain. An additional feedback form of model reference hedging is employed which is similar to a prefilter and has large benefits to system performance. The effects of inclusion of actuator dynamics into the designed plant is heavily investigated. Multiple Simulink models of the full longitudinal dynamics and wing deflection modes of the forward swept aero elastic vehicle (FSAV) are constructed. Additionally a linear state space models to analyze effects from various system parameters. The FSAV has a pole at +7 rad/sec and is non-minimum phase. The use of 'model actuators' in the feedback path, and varying there design, is heavily investigated for the resulting effects on plant robustness and tolerance to actuator failure. The use of redundant actuators is also explored and improved robustness is shown. All models are simulated with severe failure and excellent tracking, and task dependent handling qualities, and low pilot induced oscillation tendency is shown.

  6. High-resolution Slide Spotlight SAR Imaging by BP Algorithm and Heterogeneous Parallel Implementation

    Directory of Open Access Journals (Sweden)

    Tang Jiangwen

    2017-08-01

    Full Text Available High-resolution synthetic aperture radar presents a significant challenge to imaging algorithms and computing power. Slide spotlight is an important mode that has both high resolution and wide azimuth swath. Generally, in the slide spotlight mode, the performance of conventional frequency domain imaging algorithms degrades because of orbit curvature, the time-variant azimuth chirp rate, and other factors. We adopt the Back-Projection (BP algorithm in this study to counteract this limitation. We also propose a CPU/GPU heterogeneous BP algorithm to deal with the high computing complexity O(N3 of the BP algorithm. This heterogeneous BP algorithm makes full use of computing resources and accelerates imaging progress, and the design of a scheduling thread improves the flexibility of the algorithm.

  7. Slide 1

    Indian Academy of Sciences (India)

    Problem 1: Direct Materials Procurement at GM · Slide 8 · Slide 9 · Slide 10 · Game Theory · Strategic Form Games (Normal Form Games) · Example : Prisoner's Dilemma · Dominant Strategy Equilibrium · Nash Equilibrium · Nash's Theorem · Slide 17 · Slide 18 · Example 1: Mechanism Design Fair Division of a Cake.

  8. Slide 1

    Indian Academy of Sciences (India)

    Brewster angle microscopy (BAM) Images · Interaction of NPEA with DPPC: DSC · NPEA:DPPC mixtures: Phase Diagram from DSC data · Structures of Phases: 31P-NMR · Structures of Phases: SAXS · Long spacings from SAXS · Slide 38 · Slide 39 · Slide 40 · Slide 41 · Slide 42 · Slide 43 · Summary · THANKS TO ... Author: ...

  9. High Spin Baryons in Quantum Mechanical Chromodynamics

    Science.gov (United States)

    Kirchbach, M.; Compean, C. B.

    2009-04-01

    A framework of quantum mechanical chromodynamics (QMCD) is developed with the aim to place the description of the nucleon on a comparable footing with Schrödinger's quantum mechanical treatment of the hydrogen atom. Such indeed turns out to be possible upon replacing the (e--p) by a (q-qq) system, on the one hand, and the Coulomb potential by the recently reported by us exactly solvable trigonometric extension of the Cornell (TEC) potential, on the other. The TEC potential translates the inverse distance potential in ordinary flat space to a space of constant positive curvature, the 3D hypersphere, a reason for which both potentials have the SO(4) and SO(2, 1) symmetries in common. In effect, the nucleon spectrum, inclusive its Δ branch, acquire the degeneracy patterns of the electron excitations with spin in 1H without copying them, however. There are two essential differences between the N(Δ) and H atom spectra. The first concerns the parity of the states which can be unnatural for the N and Δ excitations due to compositeness of the diquark, the second refers to the level splittings in the baryon spectra which contain besides the Balmer term also its inverse of opposite sign. Our scheme reproduces the complete number of states (except the hybrid Δ(1600)), predicts a total of 33 new resonances, and explains the splittings of the N and Δ levels containing high-spin resonances. It also describes accurately the proton electric charge form factor. We here calculate the potential in momentum space (instantaneous effective gluon propagator) as a Fourier transform of the TEC potential and show that the concept of curvature allows to avoid the integral divergences suffered by schemes based on power potentials. We find a propagator that is finite at origin, likely to produce confinement. The advocated new potential picture allows for deconfinement too as effect of space flattening in the limit of infinite radius of the 3D hypersphere. The potential's SO(4)/SO(2, 1

  10. Slide 1

    Indian Academy of Sciences (India)

    Slide 39 · Slide 40 · Slide 41 · Slide 42 · Confocal images of HLE3B Cells transfected with various pEGFP-recombinant constructs · LIMBAL STEM CELL CULTURE TO RESTORE VISION Clinical Trials - 500 cases · Limbal stem cell cultures · Limbal Stem Cell Cultures · Why use HAM? Limbal Stem Cell Transplantation.

  11. Friction properties and deformation mechanisms of halite(-mica) gouges from low to high sliding velocities

    Science.gov (United States)

    Buijze, Loes; Niemeijer, André R.; Han, Raehee; Shimamoto, Toshihiko; Spiers, Christopher J.

    2017-01-01

    The evolution of friction as a function of slip rate is important in understanding earthquake nucleation and propagation. Many laboratory experiments investigating friction of fault rocks are either conducted in the low velocity regime (10-8-10-4 ms-1) or in the high velocity regime (0.01-1 m s-1). Here, we report on the evolution of friction and corresponding operating deformation mechanisms in analog gouges deformed from low to high slip rates, bridging the gap between these low and high velocity regimes. We used halite and halite-muscovite gouges to simulate processes, governing friction, active in upper crustal quartzitic fault rocks, at conditions accessible in the laboratory. The gouges were deformed over a 7 orders of magnitude range of slip rate (10-7-1 m s-1) using a low-to-high velocity rotary shear apparatus, using a normal stress of 5 MPa and room-dry humidity. Microstructural analysis was conducted to study the deformation mechanisms. Four frictional regimes as a function of slip rate could be recognized from the mechanical data, showing a transitional regime and stable sliding (10-7-10-6 m s-1), unstable sliding and weakening (10-6-10-3 m s-1), hardening (10-2-10-1 m s-1) and strong weakening (10-1-1 m s-1). Each of the four regimes can be associated with a distinct microstructure, reflecting a transition from mainly brittle deformation accompanied by pressure solution healing to temperature activated deformation mechanisms. Additionally, the frictional response of a sliding gouge to a sudden acceleration of slip rate to seismic velocities was investigated. These showed an initial strengthening, the amount of which depended on the friction level at which the step was made, followed by strong slip weakening.

  12. Study on dynamic anti-sliding stability of a high gravity dam considering complex dam foundation

    Directory of Open Access Journals (Sweden)

    Deng-hong CHEN

    2011-06-01

    Full Text Available There existed some limitations when analyzing the anti-sliding seismic stability of dam-foundation system by traditional pseudo-static method and response spectrum method. The dynamic strength reduction method was used to study on the deep anti-sliding stability of a high gravity dam considering complex dam foundation under strong earthquake-induced ground action. The static analysis was firstly carried out by reducing the shear strength parameters of the dam foundation’s rock mass with equal proportion. Then, the time-history seismic analysis was carried out based on the static analysis. It was proposed as one of dynamic instability criterions that the peak values of the dynamic displacements and plastic strain energy change suddenly with increasing strength reduction coefficient. The elasto-plastic behavior of the dam foundation was idealized using Drucker–Prager yield criterion based on associated flow rule assumption. Through the static, dynamic strength reduction analysis and dynamic linear elastic analysis of the overflow dam monolith of a high gravity dam, the results’ reliability of elastic-plastic time history analysis was confirmed. The results also showed that the rock mass strength of the high gravity dam foundation has higher strength reserve coefficient. The instability criterions of dynamic strength reduction method proposed were feasible. Although the static anti-slide analysis methods and standards of gravity dam based on the numerical methods are being discussed at present, the dynamic calculation method and instability criterions proposed in this paper would provide some meaningful suggestions for the dynamic analysis of the similar projects.

  13. Synchronization of a coupled Hodgkin-Huxley neurons via high order sliding-mode feedback

    Energy Technology Data Exchange (ETDEWEB)

    Aguilar-Lopez, R. [Division de Ciencias Basicas e Ingenieria, Universidad Autonoma Metropolitana, Av. San Pablo No. 180, Reynosa-Tamaulipas, 02200 Azcapotzalco, Mexico, D.F. (Mexico)], E-mail: raguilar@correo.azc.uam.mx; Martinez-Guerra, R. [Departamento de Control Automatico, CINVESTAV-IPN, Apartado Postal 14-740, Mexico, D.F. C.P. 07360 (Mexico)], E-mail: rguerra@ctrl.cinvestav.mx

    2008-07-15

    This work deals with the synchronizations of two both coupled Hodgkin-Huxley (H-H) neurons, where the master neuron posses inner noise and the slave neuron is considered in a resting state, (without inner noise) and an exciting state (with inner noise). The synchronization procedure is done via a feedback control, considering a class of high order sliding-mode controller which provides chattering reduction and finite time synchronization convergence, with a satisfactory performance. Theoretical analysis is done in order to show the closed-loop stability of the proposed controller and the calculated finite time for convergence. The main results are illustrated via numerical experiments.

  14. Application of Orthopedic Dual Sliding Compression Plate (ODSCP) in High Medial Tibial Open Wedge Osteotomies.

    Science.gov (United States)

    Samani, Seyed Salman; Kachooei, Amir Reza; Ebrahimzadeh, Mohammad Hosein; Omidi Kashani, Farzad; Mahdavian Naghashzargar, Reza; Razi, Shiva

    2013-04-01

    Angular deformities about the knee are one of the common disorders. High Tibial osteotomy is a way of correcting the deformity. Although the general agreement is focused toward the open wedge technique, discussion about the type of device is a subject to debate. This current study has attempted to evaluate the results of Orthopedic Dual Sliding Compression Plate (ODSCP) in high medial open wedge osteotomies of the tibia. In this cross-sectional study, 16 patients with genuvarum undergone high medial tibial open wedge osteotomy and fixed by Orthopedic Dual Sliding Compression Plate. At the time of the last follow up visit, Lysholm score was gathered. The mean follow-up time was 9.33 ± 1.87 month. The average age was 45.13 ± 7.25 years. Three patients were male and 13 patients were female. The lysholm score showed a significant difference before and after surgery. The ODSCP has many advantages over the other type of plates. It can help the surgeon to operate with a relaxed mind and it is advisable for high tibial medial open wedge osteotomies.

  15. High spin properties of 124 Ba

    Indian Academy of Sciences (India)

    The 124Ba nucleus is investigated on the basis of the method of statistical mechanics by assuming the nucleons to move in triaxially deformed Nilsson potential. The variation in the Fermi energies of protons and neutrons is studied as a function of spin and temperature. The Fermi energies determined as a function of ...

  16. High reproducibility of histological characterization by whole virtual slide quantification; an example using carotid plaque specimens.

    Directory of Open Access Journals (Sweden)

    Joyce E P Vrijenhoek

    Full Text Available Tissue biobanks are an important source for discovery and validation studies aiming for new proteins that are causally related with disease development. There is an increasing demand for accurate and reproducible histological characterization, especially for subsequent analysis and interpretation of data in association studies. We assessed reproducibility of one semiquantative and two quantitative methods for histological tissue characterization. We introduce a new automated method for whole digital slide quantification. Carotid atherosclerotic plaques were used to test reproducibility.50 atherosclerotic plaques that were obtained during carotid endarterectomy were analysed. For the semiquantitative analysis, 6 different plaque characteristics were scored in categories by two independent observers, and Cohen's κ was used to test intra- and interobserver reproducibility. The computer-aided method (assessed by two independent observers and automated method were tested on CD68 (for macrophages and α smooth muscle actin (for smooth muscle cells stainings. Agreement for these two methods (done on a continuous scale was assessed by intraclass correlation coefficients (ICCs.For the semiquantitative analysis, κ values ranged from 0.55 to 0.69 for interobserver variability, and were slightly higher for intraobserver reproducibility in both observers. The computer-aided method yielded intra- and interobserver ICCs between 0.6 and 0.9. The new automated method performed most optimal regarding reproducibility, with ICCs ranging from 0.92 to 0.97.The analysis of performance of three methods for histological slide characterization on carotid atherosclerotic plaques showed high precision and agreement in repeated measurements for the automated method for whole digital slide quantification. We suggest that this method can fulfill the need for reproducible histological quantification.

  17. High PRF ultrafast sliding compound doppler imaging: fully qualitative and quantitative analysis of blood flow.

    Science.gov (United States)

    Kang, Jinbum; Jang, Won Seuk; Yoo, Yangmo

    2018-01-15

    Ultrafast compound Doppler imaging based on plane-wave excitation (UCDI) can be used to evaluate cardiovascular diseases using high frame rates. In particular, it provides a fully quantifiable flow analysis over a large region of interest with high spatio-temporal resolution. However, the pulse-repetition frequency (PRF) in the UCDI method is limited for high-velocity flow imaging since it leverages between the number of plane-wave angles (N) and acquisition time. In this paper, we present high PRF ultrafast sliding compound Doppler imaging method (HUSDI) to improve quantitative flow analysis. With the HUSDI method, full scanline images (i.e., each tilted plane wave data) in a Doppler frame buffer are consecutively summed using a sliding window to create high-quality ensemble data so that there is no reduction in frame rate and flow sensitivity. In addition, by updating a new compounding set with a certain time difference (i.e., sliding window step size or L), the HUSDI method allows various Doppler PRFs with the same acquisition data to enable a fully qualitative, retrospective flow assessment. To evaluate the performance of the proposed HUSDI method, simulation, in vitro and in vivo studies were conducted under diverse flow circumstances. In the simulation and in vitro studies, the HUSDI method showed improved hemodynamic representations without reducing either temporal resolution or sensitivity compared to the UCDI method. For the quantitative analysis, the root mean squared velocity error (RMSVE) was measured using 9 angles (-12° to 12°) with L of 1 to 9, and the results were found to be comparable to those of the UCDI method (L=N=9), i.e., ≤ 0.24 cm/s, for all L values. For the in vivo study, the flow data acquired from a full cardiac cycle of the femoral vessels of a healthy volunteer were analyzed using a PW spectrogram, and arterial and venous flows were successfully assessed with

  18. Slide Paintings

    Science.gov (United States)

    Marshall, Sally J.

    1972-01-01

    Article describes and illustrates elementary students' paintings on 2 x 2 slides, using felt tip pens and drawing inks as well as paints to achieve experimental effects. Slides were then viewed through a projector. (PD)

  19. Observational Signature of High Spin at the Event Horizon Telescope

    Science.gov (United States)

    Gralla, Samuel E.; Lupsasca, Alexandru; Strominger, Andrew

    2018-01-01

    We analytically compute the observational appearance of an isotropically emitting point source orbiting near a rapidly spinning black hole. The primary image moves on a vertical line segment, in contrast to the primarily horizontal motion of the spinless case. Secondary images, also on the vertical line, display a rich caustic structure. If detected, this unique signature could serve as a "smoking gun" for a high spin black hole in nature.

  20. Continuous high order sliding mode controller design for a flexible air-breathing hypersonic vehicle.

    Science.gov (United States)

    Wang, Jie; Zong, Qun; Su, Rui; Tian, Bailing

    2014-05-01

    This paper investigates the problem of tracking control with uncertainties for a flexible air-breathing hypersonic vehicle (FAHV). In order to overcome the analytical intractability of this model, an Input-Output linearization model is constructed for the purpose of feedback control design. Then, the continuous finite time convergence high order sliding mode controller is designed for the Input-Output linearization model without uncertainties. In addition, a nonlinear disturbance observer is applied to estimate the uncertainties in order to compensate the controller and disturbance suppression, where disturbance observer and controller synthesis design is obtained. Finally, the synthesis of controller and disturbance observer is used to achieve the tracking for the velocity and altitude of the FAHV and simulations are presented to illustrate the effectiveness of the control strategies. Copyright © 2014 ISA. Published by Elsevier Ltd. All rights reserved.

  1. Grain boundary sliding mechanism during high temperature deformation of AZ31 Magnesium alloy

    Energy Technology Data Exchange (ETDEWEB)

    Roodposhti, Peiman Shahbeigi, E-mail: pshahbe@ncsu.edu [North Carolina State University (United States); University of Connecticut (United States); Sarkar, Apu; Murty, Korukonda Linga [North Carolina State University (United States); Brody, Harold [University of Connecticut (United States); Scattergood, Ronald [North Carolina State University (United States)

    2016-07-04

    High temperature tensile creep tests were conducted on AZ31 Magnesium alloy at low stress range of 1–13 MPa to clarify the existence of grain boundary sliding (GBS) mechanism during creep deformation. Experimental data within the GBS regime shows the stress exponent is ~2 and the activation energy value is close to that for grain boundary diffusion. Analyses of the fracture surface of the sample revealed that the GBS provides many stress concentrated sites for diffusional cavities formation and leads to premature failure. Scanning electron microscopy images show the appearances of both ductile and brittle type fracture mechanism. X-ray diffraction line profile analysis (based on Williamson-Hall technique) shows a reduction in dislocation density due to dynamic recovery (DRV). A correlation between experimental data and Langdon's model for GBS was also demonstrated.

  2. High-order sliding mode observer for fractional commensurate linear systems with unknown input

    KAUST Repository

    Belkhatir, Zehor

    2017-05-20

    In this paper, a high-order sliding mode observer (HOSMO) is proposed for the joint estimation of the pseudo-state and the unknown input of fractional commensurate linear systems with single unknown input and a single output. The convergence of the proposed observer is proved using a Lyapunov-based approach. In addition, an enhanced variant of the proposed fractional-HOSMO is introduced to avoid the peaking phenomenon and thus to improve the estimation results in the transient phase. Simulation results are provided to illustrate the performance of the proposed fractional observer in both noise-free and noisy cases. The effect of the observer’s gains on the estimated pseudo-state and unknown input is also discussed.

  3. Flexible sliding seal

    Science.gov (United States)

    Wallenhorst, E. L.

    1980-01-01

    Circular seal both slides and flexes to accomodate relative motion between two sealed members. Originally developed for Space Shuttle orbiter, it contains sliding seal to accommodate engine gimbaling and flexible seal that absorbs forward motion at high thrust of engine heat shield relative to airframe. Other possible applications are in support structures of heavy machinery and vehicle engines. Flexible sliding seal is ring about 7 feet in diameter and can withstand temperatures up to 1,600 F.

  4. Automated high throughput whole slide imaging using area sensors, flash light illumination and solid state light engine.

    Science.gov (United States)

    Varga, Viktor Sebestyén; Molnár, Béla; Virág, Tibor

    2012-01-01

    Whole Slide Imagers or digital slide scanners have developed very rapidly in the last 8 years and went through three generations. Third generation instruments have just reached the market which have the stability and throughput to be used for routine clinical work. We describe in this article the technical background and reasoning behind engineering decisions we made during the development of 3DHISTECH's 3rd generation combined brightfield and fluorescent scanner. The Panoramic 250 FLASH utilizes Plan-Apochromat 20x and 40x objectives, a 2 megapixel 3CCD camera for brightfield and a monochrome scientific CMOS camera for fluorescent scanning. A solid state light engine for fluorescent and a strobe light for bright field illumination are used. The system can scan 1cm2 including focusing at 45x resolution in 1 minute. It can scan a well stained DAPI, FITC, TRIC, 1cm2 fluorescent slide in 11 minutes. It can load and scan 250 slides in walk away mode. Using the latest camera technology and electronics, state of the art computer and standard microscope optical components high throughput high quality whole slide imaging is feasible and is sufficient for most of the routine diagnostic work. Extended depth of field and Z-stack scanning is possible with the use of area scan technology.

  5. High-spin rotational bands in 123I

    Science.gov (United States)

    Singh, Purnima; Singh, A. K.; Wilson, A. N.; Ragnarsson, I.; Hübel, H.; Bürger, A.; Carpenter, M. P.; Chmel, S.; Fallon, P.; Hagemann, G. B.; Herskind, B.; Ha, Hoa; Janssens, R. V. F.; Juhász, K.; Kardan, A.; Khoo, T. L.; Kondev, G.; Korichi, A.; Lauritsen, T.; Nyakó, B. M.; Rogers, J.; Sletten, G.; Timár, J.; Zhu, S.

    2012-12-01

    High-spin states in 123I were populated in the reaction 80Se(48Ca,p4n)123I at a beam energy of 207 MeV and γ-ray coincidence events were measured using the Gammasphere spectrometer. Three weakly populated, high-spin rotational bands have been discovered with characteristics similar to those of the long collective bands recently observed in other nuclei of this mass region. Configuration assignments are proposed based on calculations within the framework of the cranked Nilsson-Strutinsky approach.

  6. High-power 95 GHz pulsed electron spin resonance spectrometer

    Science.gov (United States)

    Hofbauer, W.; Earle, K. A.; Dunnam, C. R.; Moscicki, J. K.; Freed, J. H.

    2004-05-01

    High-field/high-frequency electron spin resonance (ESR) offers improved sensitivity and resolution compared to ESR at conventional fields and frequencies. However, most high-field/high-frequency ESR spectrometers suffer from limited mm-wave power, thereby requiring long mm-wave pulses. This precludes their use when relaxation times are short, e.g., in fluid samples. Low mm-wave power is also a major factor limiting the achievable spectral coverage and thereby the multiplex advantage of Fourier transform ESR (FTESR) experiments. High-power pulses are needed to perform two-dimensional (2D) FTESR experiments, which can unravel the dynamics of a spin system in great detail, making it an excellent tool for studying spin and molecular dynamics. We report on the design and implementation of a high-power, high-bandwidth, pulsed ESR spectrometer operating at 95 GHz. One of the principal design goals was the ability to investigate dynamic processes in aqueous samples at physiological temperatures with the intent to study biological systems. In initial experiments on aqueous samples at room temperature, we achieved 200 MHz spectral coverage at a sensitivity of 1.1×1010√s spins and a dead time of less than 50 ns. 2D-electron-electron double resonance experiments on aqueous samples are discussed to demonstrate the practical application of such a spectrometer.

  7. Continuing Medical Education Speakers with High Evaluation Scores Use more Image-based Slides

    Directory of Open Access Journals (Sweden)

    Ferguson, Ian

    2017-01-01

    Full Text Available Although continuing medical education (CME presentations are common across health professions, it is unknown whether slide design is independently associated with audience evaluations of the speaker. Based on the conceptual framework of Mayer’s theory of multimedia learning, this study aimed to determine whether image use and text density in presentation slides are associated with overall speaker evaluations. This retrospective analysis of six sequential CME conferences (two annual emergency medicine conferences over a three-year period used a mixed linear regression model to assess whether postconference speaker evaluations were associated with image fraction (percentage of image-based slides per presentation and text density (number of words per slide. A total of 105 unique lectures were given by 49 faculty members, and 1,222 evaluations (70.1% response rate were available for analysis. On average, 47.4% (SD=25.36 of slides had at least one educationally-relevant image (image fraction. Image fraction significantly predicted overall higher evaluation scores [F(1, 100.676=6.158, p=0.015] in the mixed linear regression model. The mean (SD text density was 25.61 (8.14 words/slide but was not a significant predictor [F(1, 86.293=0.55, p=0.815]. Of note, the individual speaker [χ2 (1=2.952, p=0.003] and speaker seniority [F(3, 59.713=4.083, p=0.011] significantly predicted higher scores. This is the first published study to date assessing the linkage between slide design and CME speaker evaluations by an audience of practicing clinicians. The incorporation of images was associated with higher evaluation scores, in alignment with Mayer’s theory of multimedia learning. Contrary to this theory, however, text density showed no significant association, suggesting that these scores may be multifactorial. Professional development efforts should focus on teaching best practices in both slide design and presentation skills.

  8. Continuing Medical Education Speakers with High Evaluation Scores Use more Image-based Slides.

    Science.gov (United States)

    Ferguson, Ian; Phillips, Andrew W; Lin, Michelle

    2017-01-01

    Although continuing medical education (CME) presentations are common across health professions, it is unknown whether slide design is independently associated with audience evaluations of the speaker. Based on the conceptual framework of Mayer's theory of multimedia learning, this study aimed to determine whether image use and text density in presentation slides are associated with overall speaker evaluations. This retrospective analysis of six sequential CME conferences (two annual emergency medicine conferences over a three-year period) used a mixed linear regression model to assess whether post-conference speaker evaluations were associated with image fraction (percentage of image-based slides per presentation) and text density (number of words per slide). A total of 105 unique lectures were given by 49 faculty members, and 1,222 evaluations (70.1% response rate) were available for analysis. On average, 47.4% (SD=25.36) of slides had at least one educationally-relevant image (image fraction). Image fraction significantly predicted overall higher evaluation scores [F(1, 100.676)=6.158, p=0.015] in the mixed linear regression model. The mean (SD) text density was 25.61 (8.14) words/slide but was not a significant predictor [F(1, 86.293)=0.55, p=0.815]. Of note, the individual speaker [χ2(1)=2.952, p=0.003] and speaker seniority [F(3, 59.713)=4.083, p=0.011] significantly predicted higher scores. This is the first published study to date assessing the linkage between slide design and CME speaker evaluations by an audience of practicing clinicians. The incorporation of images was associated with higher evaluation scores, in alignment with Mayer's theory of multimedia learning. Contrary to this theory, however, text density showed no significant association, suggesting that these scores may be multifactorial. Professional development efforts should focus on teaching best practices in both slide design and presentation skills.

  9. Automated high-grade prostate cancer detection and ranking on whole slide images

    Science.gov (United States)

    Huang, Chao-Hui; Racoceanu, Daniel

    2017-03-01

    Recently, digital pathology (DP) has been largely improved due to the development of computer vision and machine learning. Automated detection of high-grade prostate carcinoma (HG-PCa) is an impactful medical use-case showing the paradigm of collaboration between DP and computer science: given a field of view (FOV) from a whole slide image (WSI), the computer-aided system is able to determine the grade by classifying the FOV. Various approaches have been reported based on this approach. However, there are two reasons supporting us to conduct this work: first, there is still room for improvement in terms of detection accuracy of HG-PCa; second, a clinical practice is more complex than the operation of simple image classification. FOV ranking is also an essential step. E.g., in clinical practice, a pathologist usually evaluates a case based on a few FOVs from the given WSI. Then, makes decision based on the most severe FOV. This important ranking scenario is not yet being well discussed. In this work, we introduce an automated detection and ranking system for PCa based on Gleason pattern discrimination. Our experiments suggested that the proposed system is able to perform high-accuracy detection ( 95:57% +/- 2:1%) and excellent performance of ranking. Hence, the proposed system has a great potential to support the daily tasks in the medical routine of clinical pathology.

  10. Sliding Mode Pulsed Averaging IC Drivers for High Brightness Light Emitting Diodes

    Energy Technology Data Exchange (ETDEWEB)

    Dr. Anatoly Shteynberg, PhD

    2006-08-17

    This project developed new Light Emitting Diode (LED) driver ICs associated with specific (uniquely operated) switching power supplies that optimize performance for High Brightness LEDs (HB-LEDs). The drivers utilize a digital control core with a newly developed nonlinear, hysteretic/sliding mode controller with mixed-signal processing. The drivers are flexible enough to allow both traditional microprocessor interface as well as other options such as “on the fly” adjustment of color and brightness. Some other unique features of the newly developed drivers include • AC Power Factor Correction; • High power efficiency; • Substantially fewer external components should be required, leading to substantial reduction of Bill of Materials (BOM). Thus, the LED drivers developed in this research : optimize LED performance by increasing power efficiency and power factor. Perhaps more remarkably, the LED drivers provide this improved performance at substantially reduced costs compared to the present LED power electronic driver circuits. Since one of the barriers to market penetration for HB-LEDs (in particular “white” light LEDs) is cost/lumen, this research makes important contributions in helping the advancement of SSL consumer acceptance and usage.

  11. Spins in the vortices of a high-temperature superconductor

    DEFF Research Database (Denmark)

    Lake, B.; Aeppli, G.; Clausen, K.N.

    2001-01-01

    Neutron scattering is used to characterize the magnetism of the vortices for the optimally doped high-temperature superconductor La2-xSrxCuO4 (x = 0.163) in an applied magnetic field. As temperature is reduced, Low-frequency spin fluctuations first disappear with the loss of vortex mobility......, but then reappear. We find that the vortex state can be regarded as an inhomogeneous mixture of a superconducting spin fluid and a material containing a nearly ordered antiferromagnet. These experiments show that as for many other properties of cuprate superconductors, the important underlying microscopic forces...

  12. High spin polarization and spin splitting in equiatomic quaternary CoFeCrAl Heusler alloy

    Energy Technology Data Exchange (ETDEWEB)

    Bainsla, Lakhan; Mallick, A.I. [Department of Physics, Indian Institute of Technology Bombay, Mumbai 400076 (India); Coelho, A.A. [Instituto de Física “Gleb Wataghin”, Universidade Estadual de Campinas-UNICAMP, SP 6165, Campinas 13 083-859, Sao Paulo (Brazil); Nigam, A.K. [DCMPMS, Tata Institute of Fundamental Research, Mumbai 4000052 (India); Varaprasad, B.S.D.Ch.S.; Takahashi, Y.K. [Magnetic Materials Unit, National Institute for Materials Science, Tsukuba 305-0047 (Japan); Alam, Aftab [Department of Physics, Indian Institute of Technology Bombay, Mumbai 400076 (India); Suresh, K.G., E-mail: suresh@phy.iitb.ac.in [Department of Physics, Indian Institute of Technology Bombay, Mumbai 400076 (India); Hono, K. [Magnetic Materials Unit, National Institute for Materials Science, Tsukuba 305-0047 (Japan)

    2015-11-15

    In this paper, we investigate CoFeCrAl alloy by means of ab-initio electronic structure calculations and various experimental techniques. The alloy is found to exist in the B2-type cubic Heusler structure, which is very similar to Y-type (or LiMgPdSn prototype) structure with space group F-43m (#216). Saturation magnetization (M{sub S}) of about 2 µ{sub B}/f.u. is observed at 8 K under ambient pressure, which is in good agreement with the Slater–Pauling rule. M{sub S} values are found to be independent of pressure, which is a prerequisite for half-metals. The ab-initio electronic structure calculations predict half-metallicity for the alloy with a spin slitting energy of 0.31 eV. Importantly, this system shows a high current spin polarization value of 0.67±0.02, as deduced from the point contact Andreev reflection measurements. Linear dependence of electrical resistivity with temperature indicates the possibility of reasonably high spin polarization at elevated temperatures (~150 K) as well. All these suggest that CoFeCrAl is a promising material for the spintronic devices. - Highlights: • The ab-initio calculations predict half-metallic nature for the alloy. • Saturation magnetization (M{sub S}) gives characteristics of half-metallic nature. • Current spin polarization (P) value of 0.67±0.02 is deduced from PCAR measurements. • Deduced P is higher than those obtained for many ternary and/or quaternary alloys. • Resistivity behavior gives signature of high P at elevated temperatures.

  13. High-spin structure of neutron-rich Dy isotopes

    Indian Academy of Sciences (India)

    Abstract. In view of recent experimental progress on production and spectroscopy of neutron-rich isotopes of Dy with mass number A. 166 and 168, we have made theoretical investigations on the structure of high spin states of164 170Dy isotopes in the cranked Hartree–Fock–Bogoliubov (CHFB) theory employing a ...

  14. High-spin structure of yrast-band in Kr

    Indian Academy of Sciences (India)

    are in good agreement with the earlier measurements. [4]. The lifetimes measured and the transition quadrupole measurements can be seen in table 1. The present measurements show a drop in transition quadrupole moments at high-spins. (. 16 ). It is shown that the bandcrossing frequencies and the variation in t values ...

  15. Observation of high spin levels in Cs from Ba decay

    Indian Academy of Sciences (India)

    Abstract. The γ- and conversion electron spectra following 131Ba ε-decay are investigated, using. HPGe detector and mini-orange electron spectrometer. Attention is particularly focussed on iden- tifying weak transitions associated with low energy high spin levels in 131Cs level scheme earlier inferred in reaction studies but ...

  16. Spin relaxation in high-spin iron(III) complexes of tretraphenylporphine

    Energy Technology Data Exchange (ETDEWEB)

    Ohya, Toshie; Sato, Mitsuo (Biophysics Div., Faculty of Pharmaceutical Sciences, Teikyo Univ., Sagamiko, Kanagawa (Japan))

    1993-04-01

    The Moessbauer spectra of Fe(por)X (por=tetraphenylporphinato, TPP, and tetrakis(p-chlorophenyl)porphinato, Tp-CIPP, dianions; X=Cl, Br and I) have been measured. They show varying quadrupolar pattern depending on the temperature: Asymmetric broadening of the high-velocity line at higher temperatures, a symmetric doublet at a temperature T[sub r], and a reversal in asymmetry below T[sub r]. The temperature dependence results from temperature-dependent spin-spin relaxation in high-spin iron(III) and the off-diagonal terms of the hyperfine operator, and reflects the ionic zero-field splitting. For a given X, T[sub r] is higher and the quadrupole splitting, [Delta]E[sub Q], is larger for Tp-CIPP derivatives than for TPP derivatives. The result is explained on the basis of the resonance effect of the p-chloro substituents of the meso-phenyl groups. When por is fixed, both the values of T[sub r] and [Delta]E[sub Q] are in the order Cl

  17. First example of a high-level correlated calculation of the indirect spin-spin coupling constants involving tellurium

    DEFF Research Database (Denmark)

    Rusakov, Yury Yu; Krivdin, Leonid B.; Østerstrøm, Freja From

    2013-01-01

    This paper documents a very first example of a high-level correlated calculation of spin-spin coupling constants involving tellurium taking into account relativistic effects, vibrational corrections and solvent effects for the medium sized organotellurium molecules. The 125Te-1H spin-spin coupling...... constants of tellurophene and divinyl telluride were calculated at the SOPPA and DFT levels in a good agreement with experiment. A new full-electron basis set av3z-J for tellurium derived from the "relativistic" Dyall's basis set, dyall.av3z, and specifically optimized for the correlated calculations...

  18. Spin polarization in high density quark matter

    DEFF Research Database (Denmark)

    Bohr, Henrik; Panda, Prafulla K.; Providênci, Constanca

    2013-01-01

    We investigate the occurrence of a ferromagnetic phase transition in high density hadronic matter (e.g., in the interior of a neutron star). This could be induced by a four-fermion interaction analogous to the one which is responsible for chiral symmetry breaking in the Nambu-Jona-Lasinio model, ...

  19. Effect of niobium interlayer on high-temperature sliding friction and wear of silver films on alumina

    Energy Technology Data Exchange (ETDEWEB)

    Erdemir, A.; Erck, R.A.

    1994-03-01

    We investigated the effect of a thin Nb bond layer (15--20 mn thick) on the high-temperature sliding friction and wear of silver films ({approx}1.5 {mu}m thick) produced on {alpha}-alumina (Al{sub 2}O{sub 3}) substrates by ion-beam assisted deposition. The friction coefficients of test pairs without an Ag film fluctuated between 0.8 to 1.1, whereas the friction coefficients of pairs with an Ag film were 0.32 to 0.5. The wear of uncoated Al{sub 2}O{sub 3} balls sliding against the Ag-coated flats was reduced by factors of 25 to {approx}2000, depending on test temperature and the presence or absence of an Nb bond layer. The wear of silver-coated flats was virtually unmeasurable after tests at temperatures up to 400C. At much higher temperatures (e.g., 600C), Ag films without an Nb bond layer delaminated from the sliding surfaces and lost their effectiveness; however, Ag films with an Nb bond layer remained intact on the sliding surfaces of the Al{sub 2}O{sub 3} substrates even at 600C and continued to impart low friction and low wear.

  20. Dynamic Sliding Mode Evolution PWM Controller for a Novel High-Gain Interleaved DC-DC Converter in PV System

    Directory of Open Access Journals (Sweden)

    Taizhou Bei

    2014-01-01

    Full Text Available Considering the disadvantages of the traditional high-gain DC-DC converter such as big size, high voltage stress of switches, and large input current ripple, a novel high-gain interleaved boost converter with coupled-inductor and switched-capacitor was proposed correspondingly and the operation principle together with the steady-state analysis of this converter was also described. Besides, a new control approach-dynamic sliding mode evolution PWM controller (DSME PWM for the novel topological converter based on both dynamic evolution and sliding mode control was also presented. From the simulation results and experimental validation the proposed converter can fulfill high-gain boost, low ripple of both the input current and the output voltage. Furthermore, MPPT technique can be also achieved in a short time by simulation. The efficiency and stability of the converter proposed in this paper can be improved.

  1. High temperature resistant nanofiber by bubbfil-spinning

    Directory of Open Access Journals (Sweden)

    Li Ya

    2015-01-01

    Full Text Available Heat-resisting nanofibers have many potential applications in various industries, and the bubbfil spinning is the best candidate for mass-production of such materials. Polyether sulfone/zirconia solution with a bi-solvent system is used in the experiment. Experimental result reveals that polyether sulfone/zirconia nanofibers have higher resistance to high temperature than pure polyether sulfone fibers, and can be used as high-temperature-resistant filtration materials.

  2. Island of high-spin isomers near N = 82

    Energy Technology Data Exchange (ETDEWEB)

    Pedersen, J.; Back, B.B.; Bernthal, F.M.; Bjornholm, S.; Borggreen, J.; Christensen, O.; Folkmann, F.; Herskind, B.; Khoo, T.L.; Neiman, M.; Puehlhofer, F.; Sletten, G.

    1977-10-17

    Experiments aimed at testing for the existence of yrast traps are reported. A search for delayed ..gamma.. radiation of lifetimes longer than approx. 10 ns and of high multiplicity has been performed by producing more than 100 compound nuclei between Ba and Pb in bombardments with /sup 40/Ar, /sup 50/Ti, and /sup 65/Cu projectiles. An island of high-spin isomers is found to exist in the region 64 < or approx. = Z > or approx. = 71 and N < or approx. = 82.

  3. Collective high spin states in {sup 45}Sc

    Energy Technology Data Exchange (ETDEWEB)

    Bednarczyk, P. [Institute of Nuclear Physics, Krakow (Poland)]|[INFN, Laboratori Nazionali di Legnaro, Legnaro (Italy); Styczen, J. [Institute of Nuclear Physics, Krakow (Poland); Broda, R. [Institute of Nuclear Physics, Krakow (Poland); Lach, M. [Institute of Nuclear Physics, Krakow (Poland); Meczynski, W. [Institute of Nuclear Physics, Krakow (Poland); Bazzacco, D. [Dipartimento di Fisica dell`Universita and INFN, Padova (Italy); Brandolini, F. [Dipartimento di Fisica dell`Universita and INFN, Padova (Italy); De Angelis, G. [INFN, Laboratori Nazionali di Legnaro, Legnaro (Italy); Lunardi, S. [Dipartimento di Fisica dell`Universita and INFN, Padova (Italy); Mueller, L. [Dipartimento di Fisica dell`Universita and INFN, Padova (Italy); Medina, N. [Dipartimento di Fisica dell`Universita and INFN, Padova (Italy); Petrache, C. [INFN, Laboratori Nazionali di Legnaro, Legnaro (Italy); Rossi-Alvarez, C. [Dipartimento di Fisica dell`Universita and INFN, Padova (Italy); Scarlassara, F. [Dipartimento di Fisica dell`Universita and INFN, Padova (Italy); Segato, G.F. [Dipartimento di Fisica dell`Universita and INFN, Padova (Italy); Signorini, C. [Dipartimento di Fisica dell`Universita and INFN, Padova (Italy); Soramel, F. [Dipartimento di Fisica dell`Universita and INFN, Udine (Italy)

    1995-02-06

    The high-spin states in {sup 45}Sc were studied with the GASP multidetector array. The nuclei were excited by the {sup 30}Si({sup 18}O,p2n){sup 45}Sc reaction at E{sub LAB}=60 MeV and separated with the Recoil Mass Spectrometer. Several new high-spin levels extending the known single-particle and collective structures were observed. Energies of the negative-parity states agree with the shell model predictions whereas the positive-parity-intruder rotational band extends up to very high rotational frequencies and continues beyond the maximum angular momentum available from the single-particle f{sub 7/2} configuration. ((orig.)).

  4. High-performance fractional order terminal sliding mode control strategy for DC-DC Buck converter.

    Science.gov (United States)

    Wang, Jianlin; Xu, Dan; Zhou, Huan; Bai, Anning; Lu, Wei

    2017-01-01

    This paper presents an adaption of the fractional order terminal sliding mode control (AFTSMC) strategy for DC-DC Buck converter. The following strategy aims to design a novel nonlinear sliding surface function, with a double closed-loop structure of voltage and current. This strategy is a fusion of two characteristics: terminal sliding mode control (TSMC) and fractional order calculation (FOC). In addition, the influence of "the controller parameters" on the "performance of double closed-loop system" is investigated. It is observed that the value of terminal power has to be chosen to make a compromise between start-up and transient response of the converter. Therefore the AFTSMC strategy chooses the value of the terminal power adaptively, and this strategy can lead to the appropriate number of fractional order as well. Furthermore, through the fractional order analysis, the system can reach the sliding mode surface in a finite time. And the theoretical considerations are verified by numerical simulation. The performance of the AFTSMC and TSMC strategies is tested by computer simulations. And the comparison simulation results show that the AFTSMC exhibits a considerable improvement in terms of a faster output voltage response during load changes. Moreover, AFTSMC obtains a faster dynamical response, smaller steady-state error rate and lower overshoot.

  5. High-performance fractional order terminal sliding mode control strategy for DC-DC Buck converter.

    Directory of Open Access Journals (Sweden)

    Jianlin Wang

    Full Text Available This paper presents an adaption of the fractional order terminal sliding mode control (AFTSMC strategy for DC-DC Buck converter. The following strategy aims to design a novel nonlinear sliding surface function, with a double closed-loop structure of voltage and current. This strategy is a fusion of two characteristics: terminal sliding mode control (TSMC and fractional order calculation (FOC. In addition, the influence of "the controller parameters" on the "performance of double closed-loop system" is investigated. It is observed that the value of terminal power has to be chosen to make a compromise between start-up and transient response of the converter. Therefore the AFTSMC strategy chooses the value of the terminal power adaptively, and this strategy can lead to the appropriate number of fractional order as well. Furthermore, through the fractional order analysis, the system can reach the sliding mode surface in a finite time. And the theoretical considerations are verified by numerical simulation. The performance of the AFTSMC and TSMC strategies is tested by computer simulations. And the comparison simulation results show that the AFTSMC exhibits a considerable improvement in terms of a faster output voltage response during load changes. Moreover, AFTSMC obtains a faster dynamical response, smaller steady-state error rate and lower overshoot.

  6. Slide system for machine tools

    Science.gov (United States)

    Douglass, S.S.; Green, W.L.

    1980-06-12

    The present invention relates to a machine tool which permits the machining of nonaxisymmetric surfaces on a workpiece while rotating the workpiece about a central axis of rotation. The machine tool comprises a conventional two-slide system (X-Y) with one of these slides being provided with a relatively short travel high-speed auxiliary slide which carries the material-removing tool. The auxiliary slide is synchronized with the spindle speed and the position of the other two slides and provides a high-speed reciprocating motion required for the displacement of the cutting tool for generating a nonaxisymmetric surface at a selected location on the workpiece.

  7. Preequilibrium spin effects in Feshbach-Kerman-Koonin and exciton models and application to high-spin isomer production

    Science.gov (United States)

    Chadwick, M. B.; Young, P. G.; Oblozinsky, P.; Marcinkowski, A.

    1994-06-01

    We describe how the Feshbach-Kerman-Koonin (FKK) theory can be used to obtain residual nucleus spin distributions following preequilibrium decay, by removing the assumption of zero intrinsic spins in multistep direct reactions. By making use of parallels between the exciton model and the FKK multistep direct theory we also obtain a straightforward method for determining spin distributions in the exciton model. We compare these two approaches and apply them to high-spin isomer production cross sections in 14 MeV neutron reactions on hafnium. We obtain reasonable agreement with measurements, though there is evidence that the FKK theory underpredicts high spin transfer reactions. Comparisions with the exciton model suggest that multistep processes in FKK are underestimated, and that an FKK formulation incorporating non-normal DWBA transitions may yield results in closer agreement with the exciton model, and with experiment.

  8. Metal-Ligand Multiple Bonds in High-Spin Complexes

    OpenAIRE

    King, Evan

    2012-01-01

    The chemistry of late first row transition metals supported by dipyrromethane and dipyrromethene ligands bearing sterically bulky substituents was explored. Transition metal complexes (Mn, Fe, Co, Ni, Zn) of the dipyrromethane ligand 1,9-dimesityl-5,5-dimethyldipyrromethane (dpma) were prepared. Structural and magnetic characterization (SQUID, EPR) of the bis-pyridine adducts \\((dpma)Mn(py)_2\\), \\((dpma)Fe(py)_2\\), and \\((dpma)Co(py)_2\\) showed each tetrahedral divalent ion to be high-spin, w...

  9. Surface layer structure of AISI 1020 steel at different stages of dry sliding under electric current of high density

    OpenAIRE

    Aleutdinov, K. A.; Rubtsov, Valery Evgenjevich; Fadin, V. V.; Aleutdinova, M. I.

    2016-01-01

    Wear intensity of the sliding electric contact steel 1020/steel 1045 depending on sliding time is presented at the contact current density higher than 100 A/cm{2} without lubricant. It is shown that wear intensity of 1020 steel decreases at increasing of sliding time. Wear intensity is stabilized after some sliding time. This time (burn-in time) decreases at reduction of current density. Structural changes are realized in surface layer. Signs of liquid phase are observed on sliding surface. T...

  10. Coefficient of Friction Measurements for Thermoplastics and Fiber Composites under Low Sliding Velocity and High Pressure

    DEFF Research Database (Denmark)

    Poulios, Konstantinos; Svendsen, G.; Hiller, Jochen

    2012-01-01

    Friction materials for typical brake applications are normally designed considering thermal stability as the major performance criterion. There are however brake applications with very limited sliding velocities, where the generated heat is insignificant. In such cases it is possible that friction...... materials which are untypical for brake applications, like thermoplastics and fiber composites, can offer superior performance in terms of braking torque, wear resistance and cost than typical brake linings. In this paper coefficient of friction measurements for various thermoplastic and fiber composite...... materials running against a steel surface are presented. All tests were carried out on a pin-on-disc test-rig at a fixed sliding speed and various pressure levels for both dry and grease lubricated conditions....

  11. High-order sliding mode control for sensorless trajectory tracking of a PMSM

    Science.gov (United States)

    Delpoux, R.; Floquet, T.

    2014-10-01

    The paper presents a new sensorless approach for permanent magnet synchronous motor. Current sensors are assumed available, but position and velocity sensors are not. Based on the electrical equations, sliding mode observers are designed to estimate the back-electro motive force (EMF) of the motor. These estimations are used to reconstruct the position and the velocity. From this estimation, a robust sliding mode control is developed which ensures the position tracking of the motor. A new reference frame is used that presents advantages similar to the standard (d - q) frame, but without the need for a position sensor. The efficiency of the algorithm is shown through experimental results. The approach is potentially applicable to other types of synchronous motors as well.

  12. Rheology of grain-boundary sliding and grain interlocking at high temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Sakai, M.; Muto, H. [Toyohashi Univ. of Technology (Japan). Dept. of Materials Science

    1999-03-01

    A two-dimensional array of elastic hexagonal grains embedded in an contiguous fluid is used as a model for grain-boundary sliding and grain interlocking. The viscoelastic constitutive equation, in a phenomenological sense, is of a nonlinear Maxwell type, comprising a strain-dependent dashpot and an elastic spring connected in series. The squeezing-in/out processes and mechanisms of grain-boundary fluid essentially give rise to the rheological nonlinearity. The experimental results in stress relaxation tests of a {beta}-spodumene glass-ceramic under simple shear are characterized in a light of the nonlinear constitutive equation. It is emphasized that stress relaxation test is one of the important test techniques which enable one to study quantitatively the rheological behavior of polycrystalline ceramics with grain-boundary sliding and grain interlocking without any difficulties and ambiguities accompanied by stress-induced grain-boundary cavities which so often appear in conventional creep tests. (orig.) 9 refs.

  13. GHG effects of spinning reserve for high penetration renewables

    Energy Technology Data Exchange (ETDEWEB)

    Louis Wibberley; Peter Scaife; Joe Winsen

    2008-03-15

    This study gives a high level assessment of the greenhouse gas cost implications of providing additional backup for intermittent renewable power at a high level (20%) of penetration. The report considers international experience with higher levels of renewable generation, the Australian electricity system, and the current and likely future levels of renewables on the grids. To enable coal to provide back up/spinning reserve with a high degree of flexibility it is proposed that direct injected coal engines and novel gasification/gas engine combinations be considered. 31 refs., 17 figs., 6 tabs.

  14. High Frequency QPOs due to Black Hole Spin

    Science.gov (United States)

    Kazanas, Demos; Fukumura, K.

    2009-01-01

    We present detailed computations of photon orbits emitted by flares at the innermost stable circular orbit (ISCO) of accretion disks around rotating black holes. We show that for sufficiently large spin parameter, i.e. a > 0.94 M, flare a sufficient number of photons arrive at an observer after multiple orbits around the black hole, to produce an "photon echo" of constant lag, i.e. independent of the relative phase between the black hole and the observer, of T approximates 14 M. This constant time delay, then, leads to a power spectrum with a QPO at a frequency nu approximates 1/14M, even for a totally random ensemble of such flares. Observation of such a QPO will provide incontrovertible evidence for the high spin of the black hole and a very accurate, independent, measurement of its mass.

  15. High-spin states in sup 183 Pt

    Energy Technology Data Exchange (ETDEWEB)

    Nyberg, J. (Manne Siegbahn Inst. of Physics, Stockholm (Sweden) Royal Inst. of Tech., Stockholm (Sweden). Physics Dept. 1 Niels Bohr Inst., Roskilde (Denmark). Tandem Accelerator Lab.); Johnson, A. (Manne Siegbahn Inst. of Physics, Stockholm (Sweden) Royal Inst. of Tech., Stockholm (Sweden). Physics Dept. 1); Carpenter, M.P.; Bingham, C.R.; Courtney, L.H.; Janzen, V.P.; Juutinen, S.; Larabee, A.J.; Liu, Z.M.; Riedinger, L.L. (Tennessee Univ., Knoxville (USA). Dept. of Physics); Baktash, C.; Halbert, M.L.; Johnson, N.R.; Lee, I.Y.; Schutz, Y. (Oak Ridge National Lab., TN (USA). Holifield Heavy Ion Research Facility); Waddington, J.C.; Popescu, D.G. (McMaster Univ., Hamilton, Ontario (Canada). Tandem Accelerator Lab.)

    1990-04-30

    High-spin states in {sup 183}Pt have been studied for the first time using the reactions {sup 154}Sm({sup 34}S, 5n) and {sup 170}Yb({sup 16}O,3n). Rotational bands built on the Nilsson configurations 1/2{sup -}(521), 7/2{sup -}(514) and 9/2{sup +}(624) were observed up to spin values of 39/2-49/2{Dirac h}. Quasiparticle alignments and band crossing frequencies were investigated in these bands. A large signature splitting was observed in the {nu}i{sub 13/2}-band structure. The experimental results were compared with total routhian surface calculations, in which the shape of the nucleus could be followed as a function of rotational frequency for different quasiparticle configurations. (orig.).

  16. High current gain silicon-based spin transistor

    CERN Document Server

    Dennis, C L; Ensell, G J; Gregg, J F; Thompson, S M

    2003-01-01

    A silicon-based spin transistor of novel operating principle has been demonstrated in which the current gain at room temperature is 1.4 (n-type) and 0.97 (p-type). This high current gain was obtained from a hybrid metal/semiconductor analogue to the bipolar junction transistor which functions by tunnel-injecting carriers from a ferromagnetic emitter into a diffusion driven silicon base and then tunnel-collecting them via a ferromagnetic collector. The switching of the magnetic state of the collector ferromagnet controls the collector efficiency and the current gain. Furthermore, the magnetocurrent, which is determined to be 98% (140%) for p-type (n-type) in -110 Oe, is attributable to the spin-polarized base diffusion current.

  17. Analysis of Heat Partitioning During Sliding Contact at High Speed and Pressure

    Science.gov (United States)

    2014-03-27

    rotating workpiece. For these tests, a pin of 2.5 mm diameter and 15 mm length was made of cemented tungsten carbide . The mass of the pin was...Internal friction : the force resisting motion between the elements making up a solid material while it undergoes deformation The magnitude of...other generating a mechanical deformation , which is transformed into internal energy. Heat produced upon the sliding of two solid materials, called

  18. Summary of the 9th international symposium on high energy spin-physics

    Energy Technology Data Exchange (ETDEWEB)

    Prescott, C.Y.

    1990-11-01

    Summarizing an international conference in high energy spin physics is never an easy task, because of the wide-ranging subjects in physics and technology that are involved. I have chosen to organize the topics of this conference into three broad categories relating to spin; intrinsic spin; composite spin; and spin, the experimental tool. In the first category, I will briefly revisit some historical and recent developments to set a background. In the second category, composite spin, I will discuss the status and developments in several areas, including magnetic moments of baryons, hyperon polarization in high energy high p {perpendicular} production, transverse polarization and asymmetries from transversely polarized targets in high p {perpendicular} scattering, spin structure of the proton, and the Bjorken sum rule. In the third category, I will discuss the steady, and at times rapid, progress in spin technology. In this part I include recent progress in high energy facilities, and comment on the highlights of the Workshops.

  19. Coefficient of Friction Measurements for Thermoplastics and Fibre Composites Under Low Sliding Velocity and High Pressure

    DEFF Research Database (Denmark)

    Poulios, Konstantinos; Svendsen, Gustav Winther; Hiller, Jochen

    2013-01-01

    Friction materials for typical brake applications are normally designed considering thermal stability as the major performance criterion. There are, however, brake applications with very limited sliding velocities, where the generated heat is insignificant. In such cases it is possible that frict......Friction materials for typical brake applications are normally designed considering thermal stability as the major performance criterion. There are, however, brake applications with very limited sliding velocities, where the generated heat is insignificant. In such cases it is possible...... that friction materials which are untypical for brake applications, like thermoplastics and fibre composites, can offer superior performance in terms of braking torque, wear resistance and cost than typical brake linings. In this paper coefficient of friction measurements for various thermoplastic and fibre...... composite materials running against a steel surface are presented. All tests were carried out on a pinon-disc test-rig in reciprocating operation at a fixed sliding speed and various pressure levels for both dry and grease lubricated conditions. Moreover, a generic theoretical framework is introduced...

  20. Slide 1

    Indian Academy of Sciences (India)

    Table of contents. Slide 1 · NATIONAL JALMA INSTITUTE FOR LEPROSY & OTHER MYCOBACTERIAL DISEASES : MAJOR THRUST AREAS · NJILOMD : THRUST AREAS · Model Rural Health Research Unit Ghatampur ( Kanpur) · Current scenario · Prevalence of drug resistance · Initial drug resistance in India : static or ...

  1. Slide 1

    Indian Academy of Sciences (India)

    Communications · Milestones in Communications · Internet · Speed · Broadband Access · Digital Subscriber Line (DSL) · Wireless Access · DSL · DMT DSL · Slide 11 · Lets Focus on Upstream (US) · Upstream Mathematical Model – tone wise · Crosstalk Characteristics · Performance loss due to FEXT * · Research Issues in ...

  2. Thermodynamical analysis of spin-state transitions in LaCo O3 : Negative energy of mixing to assist thermal excitation to the high-spin excited state

    Science.gov (United States)

    Kyômen, Tôru; Asaka, Yoshinori; Itoh, Mitsuru

    2005-01-01

    Magnetic susceptibility and heat capacity due to the spin-state transition in LaCoO3 were calculated by a molecular-field model in which the energy-level diagram of high-spin state reported by Ropka and Radwanski [Phys. Rev. B 67, 172401 (2003)] is assumed for the excited state, and the energy and entropy of mixing of high-spin Co ions and low-spin Co ions are introduced phenomenologically. The experimental data below 300K were well reproduced by this model, which proposes that the high-spin excited state can be populated even if the energy of high-spin state is much larger than that of low-spin state, because the negatively large energy of mixing reduces the net excitation energy. The stability of each spin state including the intermediate-spin state is discussed based on the present results and other reports.

  3. Sub-picosecond time resolved infrared spectroscopy of high-spin state formation in Fe(II) spin crossover complexes

    DEFF Research Database (Denmark)

    Døssing, Anders Rørbæk; Wolf, Matthias M. N.; Gross, Ruth

    2008-01-01

      The photoinduced low-spin (S = 0) to high-spin (S = 2) transition of the iron(II) spin-crossover systems [Fe(btpa)](PF6)2 and [Fe(b(bdpa))](PF6)2 in solution have been studied for the first time by means of ultrafast transient infrared spectroscopy at room temperature. Negative and positive...... infrared difference bands between 1000 and 1065 cm-1 that appear within the instrumental system response time of 350 fs after excitation at 387 nm display the formation of the vibrationally unrelaxed and hot high-spin 5T2 state. Vibrational relaxation is observed and characterized by the time constants 9.......4 ± 0.7 ps for [Fe(btpa)](PF6)2/acetone and 12.7 ± 0.7 ps for both [Fe(btpa)](PF6)2/acetonitrile and [Fe(b(bdpa)](PF6)2/acetonitrile. Vibrational analysis has been performed via DFT calculations of the low-spin and high-spin state normal modes of both compounds as well as their respective infrared...

  4. Advances in large, transportable, highly spin-polarized, solid HD targets operable in the frozen-spin mode in a 1-4K temperature environment

    Science.gov (United States)

    Lewis, Aaron Paul

    The development of large, portable highly spin-polarized solid HD targets has been in progress at Syracuse University for the past 5 years. These targets are scheduled for deployment at Brookhaven National Laboratory, bearing the acronym SPHICE (Spin-Polarized Hydrogen Ice), for studies of the electro-magnetic spin structure of the nucleus via scattering of polarized gammas from the HD polarized protons and deuterons. The target work has just reached the milestone demonstration of the complete system, including polarization of triple targets containing 4 moles of solid HD, aging of these targets so that they retain their polarization for months under storage at a temperature of 1.3K and in an 8 Tesla field, and for at least a week at operational conditions of 1.3K and 0.7 Tesla in an in-beam cryostat. Cold-transfers of the polarized targets to a storage cryostat have been successfully carried out, and the storage cryostat has been trucked from Syracuse to BNL with one polarized target, sufficient to test the in-beam operations there. The complete system is presented here, with emphasis on innovations for engagement and disengagement of multiple targets, a solution to the challenge of attaining sufficiently strong RF fields in the large volume probe coils at acceptable power dissipation in the cables, and the polarization production and monitoring in the highly inhomogeneous magnetic fields owing to the multiple targets and the large dimensions of the targets. In this first multiple target production and extraction-to-storage cycle, air-ice accumulation in the dilution refrigerator due to repetitive use of cold sliding o-ring seals resulted in a rupture of one of the inserted targets, and a consequent partial thermal short from a solid HD ice bridge. The o-ring fault was cured with double evacuatable o-ring seals, and the air-ice was successfully cleaned out. However, the refrigerator operating base temperature was substantially higher than that normally obtained

  5. Implementation of a sliding-mode-based position sensorless drive for high-speed micro permanent-magnet synchronous motors.

    Science.gov (United States)

    Chi, Wen-Chun; Cheng, Ming-Yang

    2014-03-01

    Due to issues such as limited space, it is difficult if it is not impossible to employ a position sensor in the drive control of high-speed micro PMSMs. In order to alleviate this problem, this paper analyzes and implements a simple and robust position sensorless field-oriented control method of high-speed micro PMSMs based on the sliding-mode observer. In particular, the angular position and velocity of the rotor of the high-speed micro PMSM are estimated using the sliding-mode observer. This observer is able to accurately estimate rotor position in the low speed region and guarantee fast convergence of the observer in the high speed region. The proposed position sensorless control method is suitable for electric dental handpiece motor drives where a wide speed range operation is essential. The proposed sensorless FOC method is implemented using a cost-effective 16-bit microcontroller and tested in a prototype electric dental handpiece motor. Several experiments are performed to verify the effectiveness of the proposed method. © 2013 ISA. Published by Elsevier Ltd. All rights reserved.

  6. High performance fuzzy sliding mode control of DFIG supplied by seven level NPC inverter

    Directory of Open Access Journals (Sweden)

    Mohamed BENKAHLA

    2017-09-01

    Full Text Available This article presents the powers control of a variable speed wind turbine (WT based on a doubly fed induction generator (DFIG because of their advantages in terms of economy and control. The considered system consists of a double fed induction generator whose stator is connected directly to the network and its rotor is supplied by seven-level inverter with structure NPC are well used to minimize the harmonics absorbed by the DFIG. In order to control the power flowing between the stator of the DFIG and the grid. Have been studied and compared two types of controllers : Sliding Mode Control (SMC and Fuzzy SMC (FSMC. Their respective performances are compared in terms of power reference tracking, response to sudden speed variations, sensitivity to perturbations and robustness against machine parameters variations.

  7. Surface layer structure of AISI 1020 steel at different stages of dry sliding under electric current of high density

    Science.gov (United States)

    Aleutdinov, K. A.; Rubtsov, V. Ye; Fadin, V. V.; Aleutdinova, M. I.

    2016-02-01

    Wear intensity of the sliding electric contact steel 1020/steel 1045 depending on sliding time is presented at the contact current density higher than 100 A/cm2 without lubricant. It is shown that wear intensity of 1020 steel decreases at increasing of sliding time. Wear intensity is stabilized after some sliding time. This time (burn-in time) decreases at reduction of current density. Structural changes are realized in surface layer. Signs of liquid phase are observed on sliding surface. This liquid isn't a result of melting. It is established using Auger spectrometry that the contact layer contains up to 50 at.% of oxygen.

  8. High-spin research with HERA (High Energy-Resolution Array)

    Energy Technology Data Exchange (ETDEWEB)

    Diamond, R.M.

    1987-06-01

    The topic of this report is high spin research with the High Energy Resolution Array (HERA) at Lawrence Berkeley Laboratory. This is a 21 Ge detector system, the first with bismuth germanate (BGO) Compton suppression. The array is described briefly and some of the results obtained during the past year using this detector facility are discussed. Two types of studies are described: observation of superdeformation in the light Nd isotopes, and rotational damping at high spin and excitation energy in the continuum gamma ray spectrum.

  9. Storing quantum information in spins and high-sensitivity ESR.

    Science.gov (United States)

    Morton, John J L; Bertet, Patrice

    2018-02-01

    Quantum information, encoded within the states of quantum systems, represents a novel and rich form of information which has inspired new types of computers and communications systems. Many diverse electron spin systems have been studied with a view to storing quantum information, including molecular radicals, point defects and impurities in inorganic systems, and quantum dots in semiconductor devices. In these systems, spin coherence times can exceed seconds, single spins can be addressed through electrical and optical methods, and new spin systems with advantageous properties continue to be identified. Spin ensembles strongly coupled to microwave resonators can, in principle, be used to store the coherent states of single microwave photons, enabling so-called microwave quantum memories. We discuss key requirements in realising such memories, including considerations for superconducting resonators whose frequency can be tuned onto resonance with the spins. Finally, progress towards microwave quantum memories and other developments in the field of superconducting quantum devices are being used to push the limits of sensitivity of inductively-detected electron spin resonance. The state-of-the-art currently stands at around 65 spins per Hz, with prospects to scale down to even fewer spins. Copyright © 2017. Published by Elsevier Inc.

  10. High-spin yrast structure of {sup 43}Sc

    Energy Technology Data Exchange (ETDEWEB)

    Morikawa, T [Department of Physics, Kyushu University, Hakozaki, Fukuoka 812-8581 (Japan); Nakamura, M [Department of Physics, Kyushu University, Hakozaki, Fukuoka 812-8581 (Japan); Sugimitsu, T [Department of Physics, Kyushu University, Hakozaki, Fukuoka 812-8581 (Japan); Kusakari, H [Faculty of Education, Chiba University, Chiba 263-8522 (Japan); Oshima, M [Japan Atomic Energy Research Institute, Tokai, Ibaraki 319-1195 (Japan); Toh, Y [Japan Atomic Energy Research Institute, Tokai, Ibaraki 319-1195 (Japan); Koizumi, M [Japan Atomic Energy Research Institute, Tokai, Ibaraki 319-1195 (Japan); Kimura, A [Japan Atomic Energy Research Institute, Tokai, Ibaraki 319-1195 (Japan); Goto, J [Japan Atomic Energy Research Institute, Tokai, Ibaraki 319-1195 (Japan); Hatsukawa, Y [Japan Atomic Energy Research Institute, Tokai, Ibaraki 319-1195 (Japan); Sugawara, M [Chiba Institute of Technology, Narashino, Chiba 275-0023 (Japan)

    2005-01-01

    High-spin yrast states in {sup 43}Sc were investigated by using in-beam {gamma}-ray technique with the {sup 27}Al({sup 19}F,p2n) reaction at 50 MeV. The positive-parity rotational band built on the 152-keV J{sup {pi}} = 3/2{sup +} state has been extended up to the terminating J{sup {pi}} = (27/2{sup +}) state. Several fast transitions feeding to the oblate-deformed J{sup {pi}} = 19/2{sup -} isomer have been also identified. the character of the observed levels and transition rates were discussed in comparison with the shell-model calculations.

  11. High-spin states in sup 166 Lu

    Energy Technology Data Exchange (ETDEWEB)

    Hojman, D.; Kreiner, A.J.; Davidson, M.; Davidson, J.; Debray, M.; Cybulska, E.W.; Pascholati, P.; Seale, W.A. (Departamento de Fisica, Comision Nacional de Energia Atomica, 1429 Buenos Aires, Buenos Aires (Argentina) Departamento de Fisica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires (Argentina) Instituto de Fisica, Universidade de Sao Paulo, Sao Paulo (Brazil))

    1992-01-01

    High-spin states belonging to {sup 166}Lu have been studied through the {sup 159}Tb({sup 12}C,5{ital n}) fusion-evaporation reaction in the energy range {ital E}({sup 12}C)=75--90 MeV. In-beam and activity singles spectra and {gamma}-{gamma}-{ital t} coincidences have been measured. A completely new level scheme is proposed. Each rotational band is interpreted on the basis of coupling scheme systematics. {ital g}-{ital S} crossing frequencies and alignments have been extracted. {ital B}({ital M}1)/{ital B}({ital E}2) reduced transition probability ratios have been calculated using a semiclassical method and compared to the experimental values.

  12. High-frequency EPR on high-spin transition-metal sites

    NARCIS (Netherlands)

    Mathies, Guinevere

    2012-01-01

    The electronic structure of transition-metal sites can be probed by electron-paramagnetic-resonance (EPR) spectroscopy. The study of high-spin transition-metal sites benefits from EPR spectroscopy at frequencies higher than the standard 9.5 GHz. However, high-frequency EPR is a developing field. In

  13. Control of Spinning Sidebands in High Resolution NMR Spectroscopy

    Science.gov (United States)

    Borer; Maple

    1998-04-01

    The presence of spinning sidebands can severely compromise the detection of low molarity analytes. Spinning sidebands have traditionally been minimized by improving the magnetic field homogeneity and by varying the spinning of the sample in a linear fashion during data acquisition. The effect of the latter is to spread the spinning sideband intensity over a range of frequencies so that the final result is a spinning sideband whose shape reflects the distribution of spinning speeds. We have designed a customized profile of spinner speed variation that optimizes the reduction of spinning sidebands. The customized profile is based on theoretical considerations of how the intensity of sidebands vary with the rate of sample rotation and also compensates for the mechanical design of the spinner mechanism. The result is a unique combination of an exponential increase in gas flow rate to balance the theoretical considerations coupled with a strategically placed rapid change in air flow to annul the sluggish response of the spinning mechanism to acceleration. The resulting sideband shape is a broad, flat, square step in the baseline that is least likely to interfere with low molarity analyte peaks. Copyright 1998 Academic Press.

  14. Measuring spin of black holes in the universe

    Indian Academy of Sciences (India)

    Table of contents. Measuring spin of black holes in the universe · What is black hole? Accretion Disk and Jet · What is black hole's spin? Accretion Disk · Black Hole's Potential · Light Curves: Photon Count Rate Vs Time · Quasi-Periodic Oscillation · Slide 9 · Model · Slide 11 · Slide 12 · Slide 13 · Summary.

  15. Complex narrow-line Seyfert 1s : high spin or high inclination?

    OpenAIRE

    Gardner, E.; Done, C.

    2015-01-01

    Complex narrow-line Seyfert 1s (NLS1s), such as 1H 0707−495, differ from simple NLS1s like PG 1244+026 by showing stronger broad spectral features at Fe K and larger amplitude flux variability. These are correlated: the strongest Fe K features are seen during deep dips in the light curves of complex NLS1s. There are two competing explanations for these features, one where a compact X-ray source on the spin axis of a highly spinning black hole approaches the horizon and the consequent strong r...

  16. Micro-compartmentalized cultivation of cyanobacteria for mutant screening using glass slides with highly water-repellent mark

    Directory of Open Access Journals (Sweden)

    Sayuri Arai

    2014-12-01

    Full Text Available Photosynthetic microorganisms such as cyanobacteria have attracted attention for their potential to produce biofuels and biochemicals directly from CO2. Cell isolation by colony has conventionally been used for selecting target cells. Colony isolation methods require a significant amount of time for cultivation, and the colony-forming ratio is potentially low for cyanobacteria. Here, we overcome such limitations by encapsulating and culturing cells in droplets with an overlay of dodecane using glass slides printed with highly water-repellent mark. In the compartmentalized culture, the oil phase protects the small volume of culture medium from drying and increases the CO2 supply. Since a difference in cell growth was observed with and without the addition of antibiotics, this compartmentalized culture method could be a powerful tool for mutant selection.

  17. Interplay between spin polarization and color superconductivity in high density quark matter

    DEFF Research Database (Denmark)

    Tsue, Yasuhiko; da Providência, João; Providência, Constança

    2013-01-01

    Here, it is suggested that a four-point interaction of the tensor type may lead to spin polarization in quark matter at high density. It is found that the two-flavor superconducting phase and the spin polarized phase correspond to distinct local minima of a certain generalized thermodynamical...... potential. It follows that a transition from one to the other phase occurs, passing through true minima with both a spin polarization and a color superconducting gap. It is shown that the quark spin polarized phase is realized at rather high density, while the two-flavor color superconducting phase...

  18. Convolutional neural networks for an automatic classification of prostate tissue slides with high-grade Gleason score

    Science.gov (United States)

    Jiménez del Toro, Oscar; Atzori, Manfredo; Otálora, Sebastian; Andersson, Mats; Eurén, Kristian; Hedlund, Martin; Rönnquist, Peter; Müller, Henning

    2017-03-01

    The Gleason grading system was developed for assessing prostate histopathology slides. It is correlated to the outcome and incidence of relapse in prostate cancer. Although this grading is part of a standard protocol performed by pathologists, visual inspection of whole slide images (WSIs) has an inherent subjectivity when evaluated by different pathologists. Computer aided pathology has been proposed to generate an objective and reproducible assessment that can help pathologists in their evaluation of new tissue samples. Deep convolutional neural networks are a promising approach for the automatic classification of histopathology images and can hierarchically learn subtle visual features from the data. However, a large number of manual annotations from pathologists are commonly required to obtain sufficient statistical generalization when training new models that can evaluate the daily generated large amounts of pathology data. A fully automatic approach that detects prostatectomy WSIs with high-grade Gleason score is proposed. We evaluate the performance of various deep learning architectures training them with patches extracted from automatically generated regions-of-interest rather than from manually segmented ones. Relevant parameters for training the deep learning model such as size and number of patches as well as the inclusion or not of data augmentation are compared between the tested deep learning architectures. 235 prostate tissue WSIs with their pathology report from the publicly available TCGA data set were used. An accuracy of 78% was obtained in a balanced set of 46 unseen test images with different Gleason grades in a 2-class decision: high vs. low Gleason grade. Grades 7-8, which represent the boundary decision of the proposed task, were particularly well classified. The method is scalable to larger data sets with straightforward re-training of the model to include data from multiple sources, scanners and acquisition techniques. Automatically

  19. Tunable Dirac points and high spin polarization in ferromagnetic-strain graphene superlattices.

    Science.gov (United States)

    Wu, Qing-Ping; Liu, Zheng-Fang; Chen, Ai-Xi; Xiao, Xian-Bo; Miao, Guo-Xing

    2017-11-07

    Spin-dependent energy bands and transport properties of ferromagnetic-strain graphene superlattices are studied. The high spin polarization appears at the Dirac points due to the presence of spin-dependent Dirac points in the energy band structure. A gap can be induced in the vicinity of Dirac points by strain and the width of the gap is enlarged with increasing strain strength, which is beneficial for enhancing spin polarization. Moreover, a full spin polarization can be achieved at large strain strength. The position and number of the Dirac points corresponding to high spin polarization can be effectively manipulated with barrier width, well width and effective exchange field, which reveals a remarkable tunability on the wavevector filtering behavior.

  20. Spin-offs of high energy physics to society

    CERN Document Server

    Amaldi, Ugo

    2000-01-01

    Scientists are more and more frequently asked about the spin-offs of fundamental research. To answer effectively, it is important to organise the multiple aspects of knowledge and technology transfer in a coherent scheme. In this paper the spin-offs of particle physics to other fields of science and to industries are grouped in four streams: usable knowledge, people, methods and technologies. After treating these four items, with examples and suggestions of ways to improve the quality and quantity of the spin-offs, the pathways through which the results and the techniques of fundamental science percolate to society are discussed. (33 refs).

  1. A new high-spin isomer in {sup 195}Bi

    Energy Technology Data Exchange (ETDEWEB)

    Roy, T.; Mukherjee, G.; Rana, T.K.; Bhattacharya, Soumik; Asgar, Md.A.; Bhattacharya, C.; Bhattacharya, S.; Bhattacharyya, S.; Pai, H. [Variable Energy Cyclotron Centre, Kolkata (India); Madhavan, N.; Bala, I.; Gehlot, J.; Gurjar, R.K.; Jhingan, A.; Kumar, R.; Muralithar, S.; Nath, S.; Singh, R.P.; Varughese, T. [Inter University Acclerator Centre, New Delhi (India); Basu, K.; Bhattacharjee, S.S.; Ghugre, S.S.; Raut, R.; Sinha, A.K. [UGC-DAE-CSR Kolkata Centre, Kolkata (India); Palit, R. [Tata Institute of Fundamental Research, Department of Nuclear and Atomic Physics, Mumbai (India)

    2015-11-15

    A new high-spin isomer has been identified in {sup 195}Bi at the focal plane of the HYbrid Recoil mass Analyser (HYRA) used in the gas-filled mode. The fusion evaporation reactions {sup 169}Tm ({sup 30}Si, x n) {sup 193,} {sup 195}Bi were used with the beam energies on targets of 168 and 146MeV for 6n and 4n channels, respectively. The evaporation residues, separated from the fission fragments, and their decays were detected at the focal plane of HYRA using MWPC, Si-Pad and clover HPGe detectors. The half-life of the new isomer in {sup 195}Bi has been measured to be 1.6(1) μs. The configuration of the new isomer has been proposed and compared with the other isomers in this region. The Total Routhian Surface (TRS) calculations for the three-quasiparticle configurations corresponding to the new isomer suggest an oblate deformation for this isomeric state. The same calculations for different configurations in {sup 195}Bi and for the even-even {sup 194}Pb core indicate that the proton i{sub 13/2} orbital has a large shape driving effect towards oblate shape in these nuclei. (orig.)

  2. A new high-spin isomer in 195Bi

    Science.gov (United States)

    Roy, T.; Mukherjee, G.; Madhavan, N.; Rana, T. K.; Bhattacharya, Soumik; Asgar, Md. A.; Bala, I.; Basu, K.; Bhattacharjee, S. S.; Bhattacharya, C.; Bhattacharya, S.; Bhattacharyya, S.; Gehlot, J.; Ghugre, S. S.; Gurjar, R. K.; Jhingan, A.; Kumar, R.; Muralithar, S.; Nath, S.; Pai, H.; Palit, R.; Raut, R.; Singh, R. P.; Sinha, A. K.; Varughese, T.

    2015-11-01

    A new high-spin isomer has been identified in 195Bi at the focal plane of the HYbrid Recoil mass Analyser (HYRA) used in the gas-filled mode. The fusion evaporation reactions 169Tm (30Si, x n) 193, 195Bi were used with the beam energies on targets of 168 and 146MeV for 6n and 4n channels, respectively. The evaporation residues, separated from the fission fragments, and their decays were detected at the focal plane of HYRA using MWPC, Si-Pad and clover HPGe detectors. The half-life of the new isomer in 195Bi has been measured to be 1.6(1)μs. The configuration of the new isomer has been proposed and compared with the other isomers in this region. The Total Routhian Surface (TRS) calculations for the three-quasiparticle configurations corresponding to the new isomer suggest an oblate deformation for this isomeric state. The same calculations for different configurations in 195Bi and for the even-even 194Pb core indicate that the proton i 13/2 orbital has a large shape driving effect towards oblate shape in these nuclei.

  3. Shape evolution in 76, 78Kr nuclei at high spins in tilted axis ...

    Indian Academy of Sciences (India)

    A two-dimensional tilted axis cranking Hartree–Fock–Bogoliubov (CHFB) calculation is performed for 76Kr and 78Kr nuclei up to high spins = 30 employing a pairing-plus-quadrupole (PPQ) model interaction Hamiltonian. Intricate details of the evolution of single particle structures and shapes as a function of spin have ...

  4. Shape evolution in 76,78Kr nuclei at high spins in tilted axis ...

    Indian Academy of Sciences (India)

    CHFB) calculation is performed for 76Kr and 78Kr nuclei up to high spins J = 30 employing a pairing-plus-quadrupole (PPQ) model interaction Hamiltonian. Intricate details of the evolution of single particle structures and shapes as a function of spin ...

  5. High Temperature Dry Sliding Friction and Wear Performance of Laser Cladding WC/Ni Composite Coating

    Directory of Open Access Journals (Sweden)

    YANG Jiao-xi

    2016-06-01

    Full Text Available Two different types of agglomerate and angular WC/Ni matrix composite coatings were deposited by laser cladding. The high temperature wear resistance of these composite coatings was tested with a ring-on-disc MMG-10 apparatus. The morphologies of the worn surfaces were observed using a scanning electron microscopy (SEM equipped with an energy dispersive spectroscopy (EDS for elemental composition. The results show that the high temperature wear resistance of the laser clad WC/Ni-based composite coatings is improved significantly with WC mass fraction increasing. The 60% agglomerate WC/Ni composite coating has optimal high temperature wear resistance. High temperature wear mechanism of 60% WC/Ni composite coating is from abrasive wear of low temperature into composite function of the oxidation wear and abrasive wear.

  6. Spin Torque Oscillator for High Performance Magnetic Memory

    Directory of Open Access Journals (Sweden)

    Rachid Sbiaa

    2015-06-01

    Full Text Available A study on spin transfer torque switching in a magnetic tunnel junction with perpendicular magnetic anisotropy is presented. The switching current can be strongly reduced under a spin torque oscillator (STO, and its use in addition to the conventional transport in magnetic tunnel junctions (MTJ should be considered. The reduction of the switching current from the parallel state to the antiparallel state is greater than in  the opposite direction, thus minimizing the asymmetry of the resistance versus current in the hysteresis loop. This reduction of both switching current and asymmetry under a spin torque oscillator occurs only during the writing process and does not affect the thermal stability of the free layer.

  7. High-Temperature Tribological and Self-Lubricating Behavior of Copper Oxide-Doped Y-TZP Composite Sliding Against Alumina

    NARCIS (Netherlands)

    Valefi, Mahdiar; de Rooij, Matthias B.; Schipper, Dirk J.; Winnubst, Aloysius J.A.

    2011-01-01

    The tribological behavior of 5 wt% copper oxide-doped tetragonal zirconia polycrystal composite has been investigated while it slides against an alumina counterface under high temperature conditions. The effects of load (1, 2.5, and 5 N) and velocity (0.05 and 0.1 m/s) on the wear mechanism have

  8. Problems and Progress in Covariant High Spin Description

    Science.gov (United States)

    Kirchbach, Mariana; Banda Guzmán, Víctor Miguel

    2016-10-01

    A universal description of particles with spins j > 1, transforming in (j, 0) ⊕ (0, j), is developed by means of representation specific second order differential wave equations without auxiliary conditions and in covariant bases such as Lorentz tensors for bosons, Lorentz-tensors with Dirac spinor components for fermions, or, within the basis of the more fundamental Weyl- Van-der-Waerden sl(2,C) spinor-tensors. At the root of the method, which is free from the pathologies suffered by the traditional approaches, are projectors constructed from the Casimir invariants of the spin-Lorentz group, and the group of translations in the Minkowski space time.

  9. Friction properties and deformation mechanisms of halite(-mica) gouges from low to high sliding velocities

    NARCIS (Netherlands)

    Buijze, Loes|info:eu-repo/dai/nl/411880306; Niemeijer, André R.|info:eu-repo/dai/nl/370832132; Han, Raehee; Shimamoto, Toshihiko; Spiers, Christopher J.|info:eu-repo/dai/nl/304829323

    2017-01-01

    The evolution of friction as a function of slip rate is important in understanding earthquake nucleation and propagation. Many laboratory experiments investigating friction of fault rocks are either conducted in the low velocity regime (10−810−8–View the MathML source10−4 ms−1) or in the high

  10. Friction properties and deformation mechanisms of halite(-mica) gouges from low to high sliding velocities

    NARCIS (Netherlands)

    Buijze, L.; Niemeijer, A.R.; Han, R.; Shimamoto, T.; Spiers, C.J.

    2017-01-01

    The evolution of friction as a function of slip rate is important in understanding earthquake nucleation and propagation. Many laboratory experiments investigating friction of fault rocks are either conducted in the low velocity regime (10−8–10−4 ms−1) or in the high velocity regime (0.01–1 m s−1).

  11. Influence of self-affine roughness on the friction coefficient of rubber at high sliding velocity

    NARCIS (Netherlands)

    Palasantzas, G

    2004-01-01

    In this work we investigate the influence of self-affine roughness on the friction coefficient of a rubber body onto a solid surface at high speeds. The roughness is characterized by the rms amplitude w, the correlation length xi, and the roughness exponent H. It is shown that the friction

  12. Theoretical studies of possible toroidal high-spin isomers in the light-mass region

    Directory of Open Access Journals (Sweden)

    Staszczak Andrzej

    2016-01-01

    Full Text Available We review our theoretical knowledge of possible toroidal high-spin isomers in the light mass region in 28≤A≤52 obtained previously in cranked Skyrme-Hartree-Fock calculations. We report additional toroidal high-spin isomers in 56Ni with I=114ħ and 140ħ, which follow the same (multi-particle–(multi-hole systematics as other toroidal high-spin isomers. We examine the production of these exotic nuclei by fusion of various projectiles on 20Ne or 28Si as an active target in time-projection-chamber (TPC experiments.

  13. High Temperature Sliding Wear of NiAl-based Coatings Reinforced by Borides

    Directory of Open Access Journals (Sweden)

    Oleksandr UMANSKYI

    2016-05-01

    Full Text Available The development of composite materials (CM in the systems “metal-refractory compound” is one of the up-to-date trends in design of novel materials aimed at operating under the conditions of significant loads at high temperature. To design such material, NiAl, which is widely used for deposition of protective coatings on parts of gas-turbine engines, was selected for a matrix. To strengthen a NiAl under the conditions of intense wear and a broad temperature range (up to 1000 °C, it is reasonable to add refractory inclusions. Introduction of refractory borides into matrix leads to a marked increase in metal wear resistance. In order to research the behavior of the designed composites at high temperatures and to study the influence of oxides on the friction processes, the authors carried out high temperature oxidation of CM of the above systems at 1000 °С for 90 min. It was determined that all of the composites were oxidized selectively and that the thickness of oxide layers formed on the boride inclusions is 3 – 7 times that on the oxides formed on the NiAl matrix. The mechanism of wear of gas-thermal coatings of the NiAl – МеB2 systems was studied for conditions of high temperature tribotests using the «pin-on-disc» technique. The obtained results indicate that introduction of TiB2, CrB2 and ZrB2 leads to their more intense oxidation during high temperature tribotests as compared to the matrix. The oxides formed on refractory borides act as solid lubricants, which promote a decrease in wear of the contact friction pairs. For more detailed investigation of the effect of tribo-oxidation products on the friction processes, tribotests were conducted for prior oxidized (at 900 °С coatings NiAl – 15 wt.% CrB2 (TiB2, ZrB2.DOI: http://dx.doi.org/10.5755/j01.ms.22.1.8093

  14. Rolling Contact Fatigue and Wear Behavior of High-Performance Railway Wheel Steels Under Various Rolling-Sliding Contact Conditions

    Science.gov (United States)

    Faccoli, Michela; Petrogalli, Candida; Lancini, Matteo; Ghidini, Andrea; Mazzù, Angelo

    2017-07-01

    An experimental investigation was carried out to study and compare the response to cyclic loading of the high-performance railway wheel steels ER8 EN13262 and SUPERLOS®. Rolling contact tests were performed with the same contact pressure, rolling speed and sliding/rolling ratio, varying the lubrication regime to simulate different climatic conditions. The samples, machined out of wheel rims at two depths within the reprofiling layer, were coupled with UIC 900A rail steel samples. The wear rates, friction coefficients and hardness were correlated with the deformation beneath the contact surface. The crack morphology was studied, and the damage mechanisms were identified. The distribution of crack length and depth at the end of the dry tests was analyzed to quantify the damage. The main difference between the steels lies in the response of the external samples to dry contact: SUPERLOS® is subjected to a higher wear and lower friction coefficient than ER8, and this reduces the density of surface cracks that can propagate under wet contact conditions. The analysis of feedback data from in-service wheels confirmed the experimental results.

  15. Effect of Heat Treatment on the Abrasive Wear Behavior of High Chromium Iron under Dry Sliding Condition

    Directory of Open Access Journals (Sweden)

    A.A. Ayeni

    2012-06-01

    Full Text Available The effect of heat treatment on the abrasive wear behavior of high chromium cast iron (NF253AHT under dry sliding condition has been investigated. Rectangular cross sectioned samples of the alloy were produced by sand casting. After casting, the samples were machined to equal dimensions of 50 mm x 15 mm x 10 mm and heat treated by annealing, hardening and tempering. Abrasive wear tests were carried out on the samples using the pin-on-disc wear test. The tests were carried out under restricted values of speed, load and time. Within this limit, the hardened sample displayed a superior wear resistance, while the annealed sample displayed the weakest wear resistance. A graphical model (wear map displaying all the wear regimes of the alloy, which may serve as a wear predictive tool was subsequently developed from the results of the wear tests. With the exception of the as-cast and annealed specimen, all other specimens (hardened and tempered have functioned adequately in wear prone environment, but with different degree of effectiveness. Hence, the hardened and tempered samples can be used in shot blast equipments and in the grinding of minerals.

  16. High spin injection polarization at an elevated dc bias in tunnel-junction-based lateral spin valves

    Science.gov (United States)

    Wang, X. J.; Zou, H.; Ocola, L. E.; Ji, Y.

    2009-07-01

    Submicron metallic lateral spin valves are fabricated with AlOx tunnel junctions as spin injection and detection barriers. The spin polarization is estimated to be ˜20%, determined by both Hanle effect and variations of device dimensions. The polarization is maintained at a large dc injection current density >2×106 A/cm2. Both the spin polarization and spin diffusion length are weakly temperature dependent.

  17. High-resolution NMR spectroscopy of biological tissues usingprojected Magic Angle Spinning

    Energy Technology Data Exchange (ETDEWEB)

    Martin, Rachel W.; Jachmann, Rebecca C.; Sakellariou, Dimitris; Nielsen, Ulla Gro; Pines, Alexander

    2005-01-27

    High-resolution NMR spectra of materials subject toanisotropic broadening are usually obtained by rotating the sample aboutthe magic angle, which is 54.7 degrees to the static magnetic field. Inprojected Magic Angle Spinning (p-MAS), the sample is spun about twoangles, neither of which is the magic angle. This provides a method ofobtaining isotropic spectra while spinning at shallow angles. The p-MASexperiment may be used in situations where spinning the sample at themagic angle is not possible due to geometric or other constraints,allowing the choice of spinning angle to be determined by factors such asthe shape of the sample, rather than by the spin physics. The applicationof this technique to bovine tissue samples is demonstrated as a proof ofprinciple for future biological or medical applications.

  18. Sliding Controller of Switched Reluctance Motor

    Directory of Open Access Journals (Sweden)

    Abdel Ghani AISSAOUI

    2008-06-01

    Full Text Available This paper presents an application of sliding mode control for switched reluctance motor (SRM speed. The sliding mode technique finds its stronger justification in the utilization of a robust control law to model uncertainties. A sliding mode controller of the motor speed is then designed and simulated. Digital simulation results shows that the designed sliding speed controller realises a good dynamic behaviour of the motor, a perfect speed tracking with no overshoot and a good rejection of impact loads disturbance. The results of applying the sliding mode controller to a SRM give best performances and high robustness than those obtained by the application of a conventional controller (PI.

  19. Recent trends in high spin sensitivity magnetic resonance

    Science.gov (United States)

    Blank, Aharon; Twig, Ygal; Ishay, Yakir

    2017-07-01

    new ideas, show how these limiting factors can be mitigated to significantly improve the sensitivity of induction detection. Finally, we outline some directions for the possible applications of high-sensitivity induction detection in the field of electron spin resonance.

  20. High spin states in odd-odd {sup 132}Cs

    Energy Technology Data Exchange (ETDEWEB)

    Hayakawa, Takehito [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment; Lu, J.; Furuno, K. [and others

    1998-03-01

    Excited states with spin larger than 5 {Dirac_h} were newly established in the {sup 132}Cs nucleus via the {sup 124}Sn({sup 11}B,3n) reaction. Rotational bands built on the {nu}h{sub 11/2} x {pi}d{sub 5/2}, {nu}h{sub 11/2} x {pi}g{sub 7/2} and {nu}h{sub 11/2} x {pi}h{sub 11/2} configurations were observed up to spin I {approx} 16 {Dirac_h}. The {nu}h{sub 11/2} x {pi}h{sub 11/2} band shows inverted signature splitting below I < 14 {Dirac_h}. A dipole band was firstly observed in doubly odd Cs nuclei. (author)

  1. Slide 4

    Indian Academy of Sciences (India)

    First page Back Continue Last page Overview Graphics. Non-hematopoietic Stem Cells. High Proliferative Potential. Multipotent: differentiate into cells of mesenchymal and non-mesenchymal lineages. Potent immunomodulatory properties and non immunogenic; thus can be transplanted across HLA barriers ...

  2. Slide 23

    Indian Academy of Sciences (India)

    Chart: India's export basket. This can be seen in the evolution of India's export basket – high-growth manufacturing and export areas including engineering goods and pharmaceuticals which are among the most capital-intensive sectors. In contrast, leather, gems and jewelry and textiles – which are more labour intensive ...

  3. A Class of Speed-Sensorless Sliding-Mode Observers for High-Performance Induction Motor Drives

    DEFF Research Database (Denmark)

    Lascu, Christian; Boldea, Ion; Blaabjerg, Frede

    2009-01-01

    A new family of speed-sensorless sliding-mode observers for induction motor drives has been developed. Three topologies are investigated in order to determine their feasibility, parameter sensitivity, and practical applicability. The most significant feature of all schemes is that they do...

  4. New high spin states and isomers in the {sup 208}Pb and {sup 207}Pb nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Broda, R.; Wrzesinski, J.; Pawlat, T. [and others

    1996-12-31

    The two most prominent examples of the heavy doubly closed shell (DCS) nuclei, {sup 208}Pb and {sup 132}Sn, are not accessible by conventional heavy-ion fusion processes populating high-spin states. This experimental difficulty obscured for a long time the investigation of yrast high-spin states in both DCS and neighboring nuclei and consequently restricted the study of the shell model in its most attractive regions. Recent technical development of multidetector gamma arrays opened new ways to exploit more complex nuclear processes which populate the nuclei of interest with suitable yields for gamma spectroscopy and involve population of moderately high spin states. This new possibility extended the range of accessible spin values and is a promising way to reach new yrast states. Some of these states are expected to be of high configurational purity and can be a source of important shell model parameters which possibly can be used later to check the validity of the spherical shell model description at yet higher spin and higher excitation energy. The nuclei in the closest vicinity of {sup 132}Sn are produced in spontaneous fission and states with spin values up to I=14 can be reached in fission gamma spectroscopy studies with the presently achieved sensitivity of gamma arrays. New results on yrast states in the {sup 134}Te and {sup 135}I nuclei populated in fission of the {sup 248}Cm presented at this conference illustrate such application of the resolving power offered by modern gamma techniques.

  5. High-spin level structure of the neutron-rich nucleus 91Y

    CERN Document Server

    He, Xiao-Feng; Fang, Yong-De; Liu, Min-Liang; Zhang, Yu-Hu; Wang, Kai-Long; Wang, Jian-Guo; Guo, Song; Qiang, Yun-Hua; Zheng, Yong; Zhang, Ning-Tao; Li, Guang-Shun; Gao, Bing-Shui; Wu, Xiao-Guang; He, Chuang-Ye; Zheng, Yun

    2015-01-01

    High-spin level structure of the neutron-rich nucleus 91Y has been reinvestigated via the 82Se(13C, p3n)91Y reaction. A newly constructed level scheme including several key levels clarifies the uncertainties in the earlier studies. These levels are characterized by the breaking of the Z=38 and N=56 subshell closures, which involves in the spin-isospin dependent central force and tensor force.

  6. X-ray Absorption Spectroscopic Studies of High-Spin Nonheme (Alkylperoxo)iron(III) Intermediates

    Energy Technology Data Exchange (ETDEWEB)

    Shan,X.; Rohde, J.; Koehntop, K.; Zhou, Y.; Bukowski, M.; Costas, M.; Fujisawa, K.; Que, Jr., L.

    2007-01-01

    The reactions of iron(II) complexes [Fe(Tpt-Bu,i-Pr)(OH)] (1a, Tpt-Bu,i-Pr = hydrotris(3-tert-butyl-5-isopropyl-1-pyrazolyl)borate), [Fe(6-Me2BPMCN)(OTf)2] (1b, 6-Me2BPMCN = N,N'-bis((2-methylpyridin-6-yl)methyl)-N,N'-dimethyl-trans-1,2-diaminocyclohexane), and [Fe(L8Py2)(OTf)](OTf) (1c, L8Py2 = 1,5-bis(pyridin-2-ylmethyl)-1,5-diazacyclooctane) with tert-BuOOH give rise to high-spin FeIII-OOR complexes. X-ray absorption spectra (XAS) of these high-spin species show characteristic features, distinct from those of low-spin Fe-OOR complexes. These include (1) an intense 1s {yields} 3d preedge feature, with an area around 20 units, (2) an edge energy, ranging from 7122 to 7126 eV, that is affected by the coordination environment, and (3) a 1.86-1.96 Angstroms Fe-OOR bond, compared to the 1.78 Angstroms Fe-OOR bond in low-spin complexes. These unique features likely arise from a flexible first coordination sphere in those complexes. The difference in Fe-OOR bond length may rationalize differences in reactivity between low-spin and high-spin FeIII-OOR species.

  7. Persistent high-energy spin excitations in iron-pnictide superconductors.

    Science.gov (United States)

    Zhou, Ke-Jin; Huang, Yao-Bo; Monney, Claude; Dai, Xi; Strocov, Vladimir N; Wang, Nan-Lin; Chen, Zhi-Guo; Zhang, Chenglin; Dai, Pengcheng; Patthey, Luc; van den Brink, Jeroen; Ding, Hong; Schmitt, Thorsten

    2013-01-01

    Motivated by the premise that superconductivity in iron-based superconductors is unconventional and mediated by spin fluctuations, an intense research effort has been focused on characterizing the spin-excitation spectrum in the magnetically ordered parent phases of the Fe pnictides and chalcogenides. For these undoped materials, it is well established that the spin-excitation spectrum consists of sharp, highly dispersive magnons. The fate of these high-energy magnetic modes upon sizable doping with holes is hitherto unresolved. Here we demonstrate, using resonant inelastic X-ray scattering, that optimally hole-doped superconducting Ba(0.6)K(0.4)Fe(2)As(2) retains well-defined, dispersive high-energy modes of magnetic origin. These paramagnon modes are softer than, though as intense as, the magnons of undoped antiferromagnetic BaFe(2)As(2). The persistence of spin excitations well into the superconducting phase suggests that the spin fluctuations in Fe-pnictide superconductors originate from a distinctly correlated spin state. This connects Fe pnictides to cuprates, for which, in spite of fundamental electronic structure differences, similar paramagnons are present.

  8. Fabrication of highly aligned fibrous scaffolds for tissue regeneration by centrifugal spinning technology

    Energy Technology Data Exchange (ETDEWEB)

    Loordhuswamy, Amalorpava Mary [Department of Textile Technology, Anna University, Chennai 600025 (India); Krishnaswamy, Venkat Raghavan; Korrapati, Purna Sai [Department of Biomaterials, CSIR-Central Leather Research Institute, Chennai 600020 (India); Thinakaran, Senthilram [Department of Textile Technology, Anna University, Chennai 600025 (India); Rengaswami, Giri Dev Venkateshwarapuram, E-mail: vrgiridev@yahoo.com [Department of Textile Technology, Anna University, Chennai 600025 (India)

    2014-09-01

    Centrifugal spinning (C-Spin) is an emerging technology which uses centrifugal force to produce ultrafine fibers. Being a voltage free technique it can overcome the limitations of electrospinning. Owing to the unique characteristic features such as high surface area to volume ratio, porosity, mechanical strength and fiber alignment, centrifugal spun (C-spun) fibrous mat has a wide range of scope in various biomedical applications. Higher degree of fiber alignment can be effortlessly achieved by the C-Spin process. In order to prove the versatility of C-Spin system with respect to fiber alignment, Polycaprolactone (PCL) and gelatin were spun taking them as model polymers. The morphological analysis revealed that highly aligned ultrafine fibers with smooth surface are achieved by C-Spinning. Hydrophilicity, porosity and mechanical property results confirm that the C-spun mat is more suitable for tissue engineering applications. In vitro and in vivo experiments proved that the scaffolds are biocompatible and can be efficiently used as a wound dressing material. - Highlights: • Highly aligned PCL/gelatin fibrous scaffolds were prepared by C-Spinning system. • Degree of fiber alignment was influenced by the proportion of gelatin in the blends. • Direction of cell growth was parallel to the direction of fiber alignment. • C-Spun matrices can efficiently accelerate faster wound healing.

  9. Sliding vane geometry turbines

    Science.gov (United States)

    Sun, Harold Huimin; Zhang, Jizhong; Hu, Liangjun; Hanna, Dave R

    2014-12-30

    Various systems and methods are described for a variable geometry turbine. In one example, a turbine nozzle comprises a central axis and a nozzle vane. The nozzle vane includes a stationary vane and a sliding vane. The sliding vane is positioned to slide in a direction substantially tangent to an inner circumference of the turbine nozzle and in contact with the stationary vane.

  10. Spin Seebeck effect and spin Hall magnetoresistance at high temperatures for a Pt/yttrium iron garnet hybrid structure.

    Science.gov (United States)

    Wang, Shuanhu; Zou, Lvkuan; Zhang, Xu; Cai, Jianwang; Wang, Shufang; Shen, Baogen; Sun, Jirong

    2015-11-14

    Based on unique experimental setups, the temperature dependences of the longitudinal spin Seebeck effect (LSSE) and spin Hall magnetoresistance (SMR) of the Pt/yttrium iron garnet (Pt/YIG) hybrid structure are determined in a wide temperature range up to the Curie temperature of YIG. From a theoretical analysis of the experimental relationship between the SMR and temperature, the spin mixing conductance of the Pt/YIG interface is deduced as a function of temperature. Adopting the deduced spin mixing conductance, the temperature dependence of the LSSE is well reproduced based on the magnon spin current theory. Our research sheds new light on the controversy about the theoretical models for the LSSE.

  11. Spiral spin state in high-temperature copper-oxide superconductors: Evidence from neutron scattering measurements

    DEFF Research Database (Denmark)

    Lindgård, Per-Anker

    2005-01-01

    An effective spiral spin phase ground state provides a new paradigm for the high-temperature superconducting cuprates. It accounts for the recent neutron scattering observations of spin excitations regarding both the energy dispersion and the intensities, including the "universal" rotation by 45...... degrees around the resonance energy E-res. The intensity has a 2D character even in a single twin crystal. The value of E-res is related to the nesting properties of the Fermi surface. The excitations above E-res are shown to be due to in-plane spin fluctuations, a testable difference from the stripe...... model. The form of the exchange interaction function reveals the effects of the Fermi surface, and the unique shape predicts large quantum spin fluctuations in the ground state....

  12. Real-time altitude control for a quadrotor helicopter using a super-twisting controller based on high-order sliding mode observer

    Directory of Open Access Journals (Sweden)

    Ivan Gonzalez-Hernandez

    2017-01-01

    Full Text Available This article addresses the problem of altitude tracking for unmanned aircraft system when the altitude velocity is unknown, because in a practical implementation, the available sensors used to measure the vehicle’s altitude (barometer, global positioning system, laser, etc. do not provide the altitude velocity. We propose a control strategy based on both the super-twisting sliding mode controller as well as a high-order sliding mode observer to control and to estimate the altitude velocity, respectively. A comprehensive stability analysis for the combined controller–observer based on the Lyapunov stability theory is presented, ensuring the asymptotic convergence of the tracking error under external bounded disturbances. To demonstrate the performance and the effectiveness of the proposed solution, an extensive set of real-time experimental tests performed at outdoor environments is presented.

  13. Redox thermodynamics of high-spin and low-spin forms of chlorite dismutases with diverse subunit and oligomeric structures.

    Science.gov (United States)

    Hofbauer, Stefan; Bellei, Marzia; Sündermann, Axel; Pirker, Katharina F; Hagmüller, Andreas; Mlynek, Georg; Kostan, Julius; Daims, Holger; Furtmüller, Paul G; Djinović-Carugo, Kristina; Oostenbrink, Chris; Battistuzzi, Gianantonio; Obinger, Christian

    2012-11-27

    Chlorite dismutases (Clds) are heme b-containing oxidoreductases that convert chlorite to chloride and dioxygen. In this work, the thermodynamics of the one-electron reduction of the ferric high-spin forms and of the six-coordinate low-spin cyanide adducts of the enzymes from Nitrobacter winogradskyi (NwCld) and Candidatus "Nitrospira defluvii" (NdCld) were determined through spectroelectrochemical experiments. These proteins belong to two phylogenetically separated lineages that differ in subunit (21.5 and 26 kDa, respectively) and oligomeric (dimeric and pentameric, respectively) structure but exhibit similar chlorite degradation activity. The E°' values for free and cyanide-bound proteins were determined to be -119 and -397 mV for NwCld and -113 and -404 mV for NdCld, respectively (pH 7.0, 25 °C). Variable-temperature spectroelectrochemical experiments revealed that the oxidized state of both proteins is enthalpically stabilized. Molecular dynamics simulations suggest that changes in the protein structure are negligible, whereas solvent reorganization is mainly responsible for the increase in entropy during the redox reaction. Obtained data are discussed with respect to the known structures of the two Clds and the proposed reaction mechanism.

  14. Accurate Sliding-Mode Control System Modeling for Buck Converters

    DEFF Research Database (Denmark)

    Høyerby, Mikkel Christian Wendelboe; Andersen, Michael Andreas E.

    2007-01-01

    This paper shows that classical sliding mode theory fails to correctly predict the output impedance of the highly useful sliding mode PID compensated buck converter. The reason for this is identified as the assumption of the sliding variable being held at zero during sliding mode, effectively...... approach also predicts the self-oscillating switching action of the sliding-mode control system correctly. Analytical findings are verified by simulation as well as experimentally in a 10-30V/3A buck converter....

  15. Devices and process for high-pressure magic angle spinning nuclear magnetic resonance

    Energy Technology Data Exchange (ETDEWEB)

    Hoyt, David W.; Sears, Jesse A.; Turcu, Romulus V. F.; Rosso, Kevin M.; Hu, Jian Zhi

    2017-12-05

    A high-pressure magic angle spinning (MAS) rotor is detailed that includes a high-pressure sample cell that maintains high pressures exceeding 150 bar. The sample cell design minimizes pressure losses due to penetration over an extended period of time.

  16. Observations on the effects of grooved surfaces on the interfacial torque in highly loaded rolling and sliding tests

    DEFF Research Database (Denmark)

    Janakiraman, Shravan; Klit, Peder; Jensen, Niels Steenfeldt

    2014-01-01

    Some efforts have been undertaken to study the effects of grooved surfaces on the interfacial film thickness and torque between two contacting non-conformal surfaces under heavy loads. Transverse grooves of micrometer scale depth were engraved on polished, flat ring surfaces using established ind...... wavelength, load, inlet speed and slide-roll ratio. Experimental results were then justified, in certain cases, based on a multigrid model predicting the interfacial pressure and film thickness....

  17. Dispersive high-energy spin excitations in iron pnictide superconductors investigated with RIXS

    Energy Technology Data Exchange (ETDEWEB)

    Schmitt, Thorsten; Zhou, Kejin; Monney, C.; Strocov, V.N. [Paul Scherrer Institut, Villigen (Switzerland); Huang, Y.B. [Paul Scherrer Institut, Villigen (Switzerland); IOP, CAS, Beijing (China); Brink, J. van den [IFW Dresden (Germany); Ding, H. [IOP, CAS, Beijing (China)

    2012-07-01

    The discovery of iron-based high temperature superconductivity has triggered tremendous research efforts in searching for novel high-T{sub c} superconductors. Unlike cuprates, which have long-range ordered antiferromagnetic Mott insulators as parent compounds, the parent compounds of iron-based superconductors are spin-density wave metals with delocalized electronic structure and more itinerant magnetism. Recent developments of the high-resolution resonant inelastic X-ray scattering (RIXS) technique have enabled investigations of magnetic excitations in cuprates, which show excellent agreement with results from Inelastic Neutron Scattering. In this presentation we demonstrate that RIXS can be used to measure collective magnetic excitations in iron-based superconductors despite their much stronger itinerancy compared to cuprates. The persistence of high-energy spin excitations even in optimally doped pnictide superconductors in a wide range of temperatures strongly suggests a spin-mediated Cooper pairing mechanism as proposed in cuprate superconductors.

  18. The rise and fall of spinning tops

    Science.gov (United States)

    Cross, Rod

    2013-04-01

    The motion of four different spinning tops was filmed with a high-speed video camera. Unlike pointed tops, tops with a rounded peg precess initially about a vertical axis that lies well outside the top, and then spiral inward until the precession axis passes through a point close to the center-of-mass. The center-of-mass of a top with a rounded peg can rise as a result of rolling rather than sliding friction, contrary to the explanation normally given for the rise of spinning tops. A tippe top was also filmed and was observed to jump vertically off a horizontal surface several times while the center-of-mass was rising, contrary to the usual assumption that the normal reaction force on a tippe top remains approximately equal to its weight. It was found that the center-of-mass of a tippe top rises as a result of rolling friction at low spin frequencies and as a result of sliding friction at high spin frequencies. It was also found that, at low spin frequencies, a tippe top can precess at two different frequencies simultaneously.

  19. Successful fabrication of a convex platform PMMA cell-counting slide using a high-precision perpendicular dual-spindle CNC machine tool

    Science.gov (United States)

    Chen, Shun-Tong; Chang, Chih-Hsien

    2013-12-01

    This study presents a novel approach to the fabrication of a biomedical-mold for producing convex platform PMMA (poly-methyl-meth-acrylate) slides for counting cells. These slides allow for the microscopic examination of urine sediment cells. Manufacturing of such slides incorporates three important procedures: (1) the development of a tabletop high-precision dual-spindle CNC (computerized numerical control) machine tool; (2) the formation of a boron-doped polycrystalline composite diamond (BD-PCD) wheel-tool on the machine tool developed in procedure (1); and (3) the cutting of a multi-groove-biomedical-mold array using the formed diamond wheel-tool in situ on the developed machine. The machine incorporates a hybrid working platform providing wheel-tool thinning using spark erosion to cut, polish, and deburr microgrooves on NAK80 steel directly. With consideration given for the electrical conductive properties of BD-PCD, the diamond wheel-tool is thinned to a thickness of 5 µm by rotary wire electrical discharge machining. The thinned wheel-tool can grind microgrooves 10 µm wide. An embedded design, which inserts a close fitting precision core into the biomedical-mold to create step-difference (concave inward) of 50 µm in height between the core and the mold, is also proposed and realized. The perpendicular dual-spindles and precision rotary stage are features that allow for biomedical-mold machining without the necessity of uploading and repositioning materials until all tasks are completed. A PMMA biomedical-slide with a plurality of juxtaposed counting chambers is formed and its usefulness verified.

  20. Mechanism of Tennis Racket Spin Performance

    Science.gov (United States)

    Kawazoe, Yoshihiko; Okimoto, Kenji; Okimoto, Keiko

    Players often say that some strings provide a better grip and more spin than others, but ball spin did not depend on string type, gauge, or tension in pervious laboratory experiments. There was no research work on spin to uncover what is really happening during an actual tennis impact because of the difficulty of performing the appropriate experiments. The present paper clarified the mechanism of top spin and its improvement by lubrication of strings through the use of high-speed video analysis. It also provided a more detailed explanation of spin behavior by comparing a racket with lubricated strings with the famous “spaghetti” strung racket, which was banned in 1978 by the International Tennis Federation because it used plastic spaghetti tubing over the strings to reduce friction, resulting in excessive ball spin. As the main strings stretch and slide sideways more, the ball is given additional spin due to the restoring force parallel to the string face when the main strings spring back and the ball is released from the strings. Herein, we also showed that the additional spin results in a reduction of shock vibrations of the wrist joint during impact.

  1. Generating highly polarized nuclear spins in solution using dynamic nuclear polarization

    DEFF Research Database (Denmark)

    Wolber, J.; Ellner, F.; Fridlund, B.

    2004-01-01

    and other low-γ nuclei. Subsequent to the DNP process, the solid sample is dissolved rapidly with a warm solvent to create a solution of molecules with highly polarized nuclear spins. Two main applications are proposed: high-resolution liquid state NMR with enhanced sensitivity, and the use...

  2. High resolution x-ray fluorescence spectroscopy - a new technique for site- and spin-selectivity

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Xin [Univ. of California, Davis, CA (United States). Dept. of Applied Science

    1996-12-01

    X-ray spectroscopy has long been used to elucidate electronic and structural information of molecules. One of the weaknesses of x-ray absorption is its sensitivity to all of the atoms of a particular element in a sample. Through out this thesis, a new technique for enhancing the site- and spin-selectivity of the x-ray absorption has been developed. By high resolution fluorescence detection, the chemical sensitivity of K emission spectra can be used to identify oxidation and spin states; it can also be used to facilitate site-selective X-ray Absorption Near Edge Structure (XANES) and site-selective Extended X-ray Absorption Fine Structure (EXAFS). The spin polarization in K fluorescence could be used to generate spin selective XANES or spin-polarized EXAFS, which provides a new measure of the spin density, or the nature of magnetic neighboring atoms. Finally, dramatic line-sharpening effects by the combination of absorption and emission processes allow observation of structure that is normally unobservable. All these unique characters can enormously simplify a complex x-ray spectrum. Applications of this novel technique have generated information from various transition-metal model compounds to metalloproteins. The absorption and emission spectra by high resolution fluorescence detection are interdependent. The ligand field multiplet model has been used for the analysis of K{alpha} and K{beta} emission spectra. First demonstration on different chemical states of Fe compounds has shown the applicability of site selectivity and spin polarization. Different interatomic distances of the same element in different chemical forms have been detected using site-selective EXAFS.

  3. Electron magnetic resonance data on high-spin Mn(III; S=2) ions in porphyrinic and salen complexes modeled by microscopic spin Hamiltonian approach.

    Science.gov (United States)

    Tadyszak, Krzysztof; Rudowicz, Czesław; Ohta, Hitoshi; Sakurai, Takahiro

    2017-10-01

    The spin Hamiltonian (SH) parameters experimentally determined by EMR (EPR) may be corroborated or otherwise using various theoretical modeling approaches. To this end semiempirical modeling is carried out for high-spin (S=2) manganese (III) 3d 4 ions in complex of tetraphenylporphyrinato manganese (III) chloride (MnTPPCl). This modeling utilizes the microscopic spin Hamiltonians (MSH) approach developed for the 3d 4 and 3d 6 ions with spin S=2 at orthorhombic and tetragonal symmetry sites in crystals, which exhibit an orbital singlet ground state. Calculations of the zero-field splitting (ZFS) parameters and the Zeeman electronic (Ze) factors (g || =g z , g ⊥ =g x =g y ) are carried out for wide ranges of values of the microscopic parameters using the MSH/VBA package. This enables to examine the dependence of the theoretically determined ZFS parameters b k q (in the Stevens notation) and the Zeeman factors g i on the spin-orbit (λ), spin-spin (ρ) coupling constant, and the ligand-field energy levels (Δ i ) within the 5 D multiplet. The results are presented in suitable tables and graphs. The values of λ, ρ, and Δ i best describing Mn(III) ions in MnTPPCl are determined by matching the theoretical second-rank ZFSP b 2 0 (D) parameter and the experimental one. The fourth-rank ZFS parameters (b 4 0 , b 4 4 ) and the ρ (spin-spin)-related contributions, which have been omitted in previous studies, are considered for the first time here and are found important. Semiempirical modeling results are compared with those obtained recently by the density functional theory (DFT) and/or ab initio methods. Copyright © 2017 Elsevier Inc. All rights reserved.

  4. Non-collective high-spin states in /sup 148/Dy

    Energy Technology Data Exchange (ETDEWEB)

    Dines, E.L.

    1985-04-01

    General physical concepts regarding nuclear high-spin states are given. The high-spin states in /sup 148/Dy(Z = 66, N = 82) were produced via the reaction /sup 112/Cd(Pb-backed)(/sup 40/Ar,4n) at E/sub lab/ = 175, at the 88-inch Cyclotron at Lawrence Berkeley Laboratory. Methods for placing gates on various transitions above and below the 480 nsec isomer at 10/sup +/(known from previous work), as well as for calculating transition intensities and their associated errors, are given. Calculations of angular correlations for multiple ..gamma..-ray cascades, assuming non-zero-width distributions in m-states for some given spin state, were done and compared to experimental values. Analysis of RF - Ge and Ge - Ge TAC spectra for transitions above the 480 nsec isomer implied lifetimes of less than or equal to 5 nsec (except for the 327.2 keV transition). Using such analysis, some 19 new ..gamma..-ray transitions were discovered above the isomer, thereby extending the /sup 148/Dy level scheme up to spin I = 31 h-bar. Assignments of spins and parities for the new levels are made based on information obtained from angular correlations and the lifetime limits. Previous work on the 11 transitions below the 480 nsec isomer is confirmed.

  5. Observation of high-spin oblate band structures in Pm141

    Science.gov (United States)

    Gu, L.; Zhu, S. J.; Wang, J. G.; Yeoh, E. Y.; Xiao, Z. G.; Zhang, S. Q.; Meng, J.; Zhang, M.; Liu, Y.; Ding, H. B.; Xu, Q.; Zhu, L. H.; Wu, X. G.; He, C. Y.; Li, G. S.; Wang, L. L.; Zheng, Y.; Zhang, B.

    2011-06-01

    The high-spin states of Pm141 have been investigated through the reaction Te126(F19,4n) at a beam energy of 90 MeV. A previous level scheme has been updated with spins up to 49/2ℏ. Six collective bands at high spins are newly observed. Based on the systematic comparison, one band is proposed as a decoupled band; two bands with strong ΔI=1 M1 transitions inside the bands are suggested as the oblate bands with γ ~-60°; three other bands with large signature splitting have been proposed with the oblate-triaxial deformation with γ~ -90°. The triaxial n-particle-n-hole particle rotor model calculations for one of the oblate bands in Pm141 are in good agreement with the experimental data. The other characteristics for these bands have been discussed.

  6. Complex narrow-line Seyfert 1s: high spin or high inclination?

    Science.gov (United States)

    Gardner, Emma; Done, Chris

    2015-04-01

    Complex narrow-line Seyfert 1s (NLS1s), such as 1H 0707-495, differ from simple NLS1s like PG 1244+026 by showing stronger broad spectral features at Fe K and larger amplitude flux variability. These are correlated: the strongest Fe K features are seen during deep dips in the light curves of complex NLS1s. There are two competing explanations for these features, one where a compact X-ray source on the spin axis of a highly spinning black hole approaches the horizon and the consequent strong relativistic effects focus the intrinsic flux on to the inner edge of a thin disc, giving a dim, reflection-dominated spectrum. The other is that the deep dips are caused by complex absorption by clumps close to the hard X-ray source. The reflection-dominated model is able to reproduce the very short 30 s soft lag from reverberation seen in the complex NLS1 1H 0707-495. However, it does not explain the characteristic switch to hard lags on longer time-scales. Instead, a full model of propagating fluctuations coupled to reverberation can explain the switch in the simple NLS1 PG 1244+026 using a low spin black hole. However, PG 1244+026 has a longer reverberation lag of ˜200 s. Here we extend the successful propagation-reverberation model for the simple NLS1 PG 1244+026 to include the effect of absorption from clumps in a turbulent region above the disc. The resulting occultations of the inner accretion flow can introduce additional hard lags when relativistic effects are taken into account. This dilutes the soft lag from reverberation and shifts it to higher frequencies, making a smooth transition between the 200 s lags seen in simple NLS1s to the 30 s lags in complex NLS1s. These two classes of NLS1 could then be determined by inclination angle with respect to a clumpy, probably turbulent, failed wind structure on the disc.

  7. Unexpected Spin-Crossover and a Low-Pressure Phase Change in an Iron(II)/Dipyrazolylpyridine Complex Exhibiting a High-Spin Jahn-Teller Distortion.

    Science.gov (United States)

    Kershaw Cook, Laurence J; Thorp-Greenwood, Flora L; Comyn, Tim P; Cespedes, Oscar; Chastanet, Guillaume; Halcrow, Malcolm A

    2015-07-06

    The synthesis of 4-methyl-2,6-di(pyrazol-1-yl)pyridine (L) and four salts of [FeL2]X2 (X(-) = BF4(-), 1; X(-) = ClO4(-), 2; X(-) = PF6(-), 3; X(-) = CF3SO3(-), 4) are reported. Powder samples of 1 and 2 both exhibit abrupt, hysteretic spin-state transitions on cooling, with T1/2↓ = 204 and T1/2↑ = 209 K (1), and T1/2↓ = 175 and T1/2↑ = 193 K (2). The 18 K thermal hysteresis loop for 2 is unusually wide for a complex of this type. Single crystal structures of 2 show it to exhibit a Jahn-Teller-distorted six-coordinate geometry in its high-spin state, which would normally inhibit spin-crossover. Bulk samples of 1 and 2 are isostructural by X-ray powder diffraction, and undergo a crystallographic phase change during their spin-transitions. At temperatures below T1/2, exposing both compounds to 10(-5) Torr pressure inside the powder diffractometer causes a reversible transformation back to the high-temperature crystal phase. Consideration of thermodynamic data implies this cannot be accompanied by a low → high spin-state change, however. Both compounds also exhibit the LIESST effect, with 2 exhibiting an unusually high T(LIESST) of 112 K. The salts 3 and 4 are respectively high-spin and low-spin between 3 and 300 K, with crystalline 3 exhibiting a more pronounced version of the same Jahn-Teller distortion.

  8. X-Ray Absorption Spectroscopic Studies of High-Spin Nonheme (Alkylperoxo)Iron(III) Intermediates

    Energy Technology Data Exchange (ETDEWEB)

    Shan, X.; Rohde, J.-U.; Koehntop, K.D.; Zhou, Y.; Bukowski, M.R.; Costas, M.; Fujisawa, K.; Que, L.; Jr.

    2009-06-04

    The reactions of iron(II) complexes [Fe(Tp{sup t-Bu,i-Pr})(OH)] (1a, Tp{sup t-Bu,i-Pr} = hydrotris(3-tert-butyl-5-isopropyl-1-pyrazolyl)borate), [Fe(6-Me{sub 2}BPMCN)(OTf){sub 2}] (1b, 6-Me{sub 2}BPMCN = N,N'-bis((2-methylpyridin-6-yl)methyl)-N,N'-dimethyl-trans-1,2-diaminocyclohexane), and [Fe(L{sup 8}Py{sub 2})(OTf)](OTf) (1c, L{sup 8}Py{sub 2} = 1,5-bis(pyridin-2-ylmethyl)-1,5-diazacyclooctane) with tert-BuOOH give rise to high-spin Fe{sup III}-OOR complexes. X-ray absorption spectra (XAS) of these high-spin species show characteristic features, distinct from those of low-spin Fe-OOR complexes (Rohde, J.-U.; et al. J. Am. Chem. Soc. 2004, 126, 16750--16761). These include (1) an intense 1s {yields} 3d preedge feature, with an area around 20 units, (2) an edge energy, ranging from 7122 to 7126 eV, that is affected by the coordination environment, and (3) a 1.86--1.96 {angstrom} Fe-OOR bond, compared to the 1.78 {angstrom} Fe-OOR bond in low-spin complexes. These unique features likely arise from a flexible first coordination sphere in those complexes. The difference in Fe-OOR bond length may rationalize differences in reactivity between low-spin and high-spin Fe{sup III}-OOR species.

  9. Universality, maximum radiation, and absorption in high-energy collisions of black holes with spin.

    Science.gov (United States)

    Sperhake, Ulrich; Berti, Emanuele; Cardoso, Vitor; Pretorius, Frans

    2013-07-26

    We explore the impact of black hole spins on the dynamics of high-energy black hole collisions. We report results from numerical simulations with γ factors up to 2.49 and dimensionless spin parameter χ=+0.85, +0.6, 0, -0.6, -0.85. We find that the scattering threshold becomes independent of spin at large center-of-mass energies, confirming previous conjectures that structure does not matter in ultrarelativistic collisions. It has further been argued that in this limit all of the kinetic energy of the system may be radiated by fine tuning the impact parameter to threshold. On the contrary, we find that only about 60% of the kinetic energy is radiated for γ=2.49. By monitoring apparent horizons before and after scattering events we show that the "missing energy" is absorbed by the individual black holes in the encounter, and moreover the individual black-hole spins change significantly. We support this conclusion with perturbative calculations. An extrapolation of our results to the limit γ→∞ suggests that about half of the center-of-mass energy of the system can be emitted in gravitational radiation, while the rest must be converted into rest-mass and spin energy.

  10. Spin-polarized high-energy scattering of charged leptons on nucleons

    Energy Technology Data Exchange (ETDEWEB)

    Burkardt, M. [New Mexico State Univ., Las Cruces, NM (United States). Dept. of Physics; Miller, C.A. [TRIUMF, Vancouver, BC (Canada); Nowak, W.D. [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany)

    2009-08-15

    The proton is a composite object with spin one-half, understood to contain highly relativistic spin one-half quarks exchanging spin-one gluons, each possibly with significant orbital angular momenta. While their fundamental interactions are well described by Quantum ChromoDynamics (QCD), our standard theory of the strong interaction, nonperturbative calculations of the internal structure of the proton based directly on QCD are beginning to provide reliable results. Most of our present knowledge of the structure of the proton is based on experimental measurements interpreted within the rich framework of QCD. An area presently attracting intense interest, both experimental and theoretical, is the relationship between the spin of the proton and the spins and orbital angular momenta of its constituents. While remarkable progress has been made, especially in the last decade, the discovery and investigation of new concepts have revealed that much more remains to be learned. This progress is reviewed and an outlook for the future is offered. (orig.)

  11. Physical limitations to efficient high-speed spin-torque switching in magnetic tunnel junctions

    Science.gov (United States)

    Heindl, R.; Rippard, W. H.; Russek, S. E.; Kos, A. B.

    2011-02-01

    We have investigated the physical limitations to efficient high-speed spin-torque switching by means of write error rates both experimentally as well as through macrospin simulations. The spin-torque-induced write operations were performed on in-plane MgO magnetic tunnel junctions. The write error rates were determined from up to 106 switching events as a function of pulse amplitude and duration (5 to 100 ns) for devices with different thermal stability factors. Both experiments and simulations show qualitatively similar results. In particular, the write error rates as a function of pulse voltage amplitude increase at higher rates for pulse durations below ≈50 ns. Simulations show that the write error rates can be reduced only to some extent by the use of materials with perpendicular anisotropy and reduced damping, whereas noncollinear orientation of the spin current polarization and the magnetic easy axis increases the write error rates. The cause for the write error rates is related to the underlying physics of spin-torque switching and the occurrence of the stagnation point on the magnetization switching trajectory where the spin-torque disappears and the device loses the energy needed to switch. The stagnation point can be accessed either during the initial magnetization distribution or by thermal diffusion during the switching process.

  12. Highly mobile gapless excitations in a two-dimensional candidate quantum spin liquid.

    Science.gov (United States)

    Yamashita, Minoru; Nakata, Norihito; Senshu, Yoshinori; Nagata, Masaki; Yamamoto, Hiroshi M; Kato, Reizo; Shibauchi, Takasada; Matsuda, Yuji

    2010-06-04

    The nature of quantum spin liquids, a novel state of matter where strong quantum fluctuations destroy the long-range magnetic order even at zero temperature, is a long-standing issue in physics. We measured the low-temperature thermal conductivity of the recently discovered quantum spin liquid candidate, the organic insulator EtMe3Sb[Pd(dmit)2]2. A sizable linear temperature dependence term is clearly resolved in the zero-temperature limit, indicating the presence of gapless excitations with an extremely long mean free path, analogous to excitations near the Fermi surface in pure metals. Its magnetic field dependence suggests a concomitant appearance of spin-gap-like excitations at low temperatures. These findings expose a highly unusual dichotomy that characterizes the low-energy physics of this quantum system.

  13. PROCEEDINGS OF RIKEN BNL RESEARCH CENTER WORKSHOP CIRCUM-PAN-PACIFIC RIKEN SYMPOSIUM ON HIGH ENERGY SPIN PHYSICS, VOLUME 25

    Energy Technology Data Exchange (ETDEWEB)

    KUMANO,S.; SHIBATA,T.A.; YAZAKI,K.

    2000-06-28

    The Circum-Pan-Pacific Riken Symposium on High Energy Spin Physics was held at Oukouchi Memorial Hall in Riken from November 3 through 6, 1999. It was held as a joint meeting of the 2nd Circum-Pan-Pacific Symposium on High Energy Spin Physics and the 3rd of the series of Riken Symposia related to the RHIC-SPIN. The 1st Circum-Pan-Pacific Symposium on High Energy Spin Physics was held at Kobe in 1996 and the RHIC-SPIN Riken Symposia had been held every two years since 1995. As Prof. Ozaki mentioned in his talk at the beginning of this meeting, the RHIC was ready for the first beam, physics experiments scheduled in 2000, and the RHIC-SPIN would start in 2001. It was therefore considered to be very timely for the researchers in the field of high energy spin physics to get together, clarifying the present status of the field and discussing interesting and important topics as well as experimental subjects to be pursued. It is especially important for the success of the RHIC-SPIN project that the researchers in the neighboring countries surrounding the Pacific are actively involved in it. This is why the above two series were joined in this. symposium. The subjects discussed in the symposium include: Hard processes probing spin-structure functions, polarization mechanisms in high energy reactions, lattice studies of polarized structure functions, theoretical models for the nucleon and its spin structure, RHIC and RHIC-SPIN projects, results and future projects of existing experimental facilities. Totally 73 scientists participated in the symposium, 27 from abroad and 46 from Japan. it consisted of 13 main sessions, with 33 invited and contributed talks, and 4 discussion sessions covering recent experimental and theoretical developments and important topics in high energy spin physics and closely related fields.

  14. Effect of high-frequency excitation on natural frequencies of spinning discs

    DEFF Research Database (Denmark)

    Hansen, Morten Hartvig

    2000-01-01

    The effect of high-frequency, non-resonant parametric excitation on the low-frequency response of spinning discs is considered. The parametric excitation is obtained through a non-constant rotation speed, where the frequency of the pulsating overlay is much higher than the lowest natural frequenc...

  15. Spin polarization versus color–flavor locking in high-density quark matter

    DEFF Research Database (Denmark)

    Tsue, Yasuhiko; da Providência, João; Providência, Constança

    2015-01-01

    It is shown that spin polarization with respect to each flavor in three-flavor quark matter occurs instead of color–flavor locking at high baryon density by using the Nambu–Jona-Lasinio model with four-point tensor-type interaction. Also, it is indicated that the order of phase transition between...

  16. Ill-defined block-spin transformations at arbitrarily high temperatures

    NARCIS (Netherlands)

    Enter, Aernout C.D. van

    Examples are presented of block-spin transformations which map the Gibbs measures of the Ising model in two or more dimensions at temperature intervals extending to arbitrarily high temperatures onto non-Gibbsian measures. In this way we provide the first example of this kind of pathology for very

  17. Towards better digital pathology workflows: programming libraries for high-speed sharpness assessment of Whole Slide Images.

    Science.gov (United States)

    Ameisen, David; Deroulers, Christophe; Perrier, Valérie; Bouhidel, Fatiha; Battistella, Maxime; Legrès, Luc; Janin, Anne; Bertheau, Philippe; Yunès, Jean-Baptiste

    2014-01-01

    Since microscopic slides can now be automatically digitized and integrated in the clinical workflow, quality assessment of Whole Slide Images (WSI) has become a crucial issue. We present a no-reference quality assessment method that has been thoroughly tested since 2010 and is under implementation in multiple sites, both public university-hospitals and private entities. It is part of the FlexMIm R&D project which aims to improve the global workflow of digital pathology. For these uses, we have developed two programming libraries, in Java and Python, which can be integrated in various types of WSI acquisition systems, viewers and image analysis tools. Development and testing have been carried out on a MacBook Pro i7 and on a bi-Xeon 2.7GHz server. Libraries implementing the blur assessment method have been developed in Java, Python, PHP5 and MySQL5. For web applications, JavaScript, Ajax, JSON and Sockets were also used, as well as the Google Maps API. Aperio SVS files were converted into the Google Maps format using VIPS and Openslide libraries. We designed the Java library as a Service Provider Interface (SPI), extendable by third parties. Analysis is computed in real-time (3 billion pixels per minute). Tests were made on 5000 single images, 200 NDPI WSI, 100 Aperio SVS WSI converted to the Google Maps format. Applications based on our method and libraries can be used upstream, as calibration and quality control tool for the WSI acquisition systems, or as tools to reacquire tiles while the WSI is being scanned. They can also be used downstream to reacquire the complete slides that are below the quality threshold for surgical pathology analysis. WSI may also be displayed in a smarter way by sending and displaying the regions of highest quality before other regions. Such quality assessment scores could be integrated as WSI's metadata shared in clinical, research or teaching contexts, for a more efficient medical informatics workflow.

  18. High-dimensional quantum state transfer through a quantum spin chain

    Science.gov (United States)

    Qin, Wei; Wang, Chuan; Long, Gui Lu

    2013-01-01

    In this paper, we investigate a high-dimensional quantum state transfer protocol. An arbitrary unknown high-dimensional state can be transferred with high fidelity between two remote registers through an XX coupling spin chain of arbitrary length. The evolution of the state transfer is determined by the natural dynamics of the chain without external modulation and coupling strength engineering. As a consequence, entanglement distribution with a high efficiency can be achieved. Also the strong field and high spin quantum number can partly counteract the effect of finite temperature to ensure the high fidelity of the protocol when the quantum data bus is in the thermal equilibrium state under an external magnetic field.

  19. Mailing microscope slides

    Science.gov (United States)

    Many insects feed agriculturally important crops, trees, and ornamental plants and cause millions of dollars of damage annually. Identification for some of these require the preparation of a microscope slide for examination. There are times when a microscope slide may need to be sent away to a speci...

  20. Population of high-spin isomeric states following fragmentation of 238U

    Science.gov (United States)

    Bowry, M.; Podolyák, Zs.; Pietri, S.; Kurcewicz, J.; Bunce, M.; Regan, P. H.; Farinon, F.; Geissel, H.; Nociforo, C.; Prochazka, A.; Weick, H.; Al-Dahan, N.; Alkhomashi, N.; Allegro, P. R. P.; Benlliure, J.; Benzoni, G.; Boutachkov, P.; Bruce, A. M.; Denis Bacelar, A. M.; Farrelly, G. F.; Gerl, J.; Górska, M.; Gottardo, A.; Grębosz, J.; Gregor, N.; Janik, R.; Knöbel, R.; Kojouharov, I.; Kubo, T.; Kurz, N.; Litvinov, Yu. A.; Merchan, E.; Mukha, I.; Naqvi, F.; Pfeiffer, B.; Pfützner, M.; Plaß, W.; Pomorski, M.; Riese, B.; Ricciardi, M. V.; Schmidt, K.-H.; Schaffner, H.; Scheidenberger, C.; Simpson, E. C.; Sitar, B.; Spiller, P.; Stadlmann, J.; Strmen, P.; Sun, B.; Tanihata, I.; Terashima, S.; Valiente Dobón, J. J.; Winfield, J. S.; Wollersheim, H.-J.; Woods, P. J.

    2013-08-01

    Isomeric ratios have been determined for 23 metastable states identified in A≈200 nuclei from Pt to Rn near the valley of stability following fragmentation of 238U. This includes high-spin states with angular momenta ranging from (39/2)ℏ to 25ℏ. The experimental results are discussed together with those of similar experiments performed in this mass region. Isomeric ratios are compared with theoretical predictions where the angular momentum of the fragment arises purely due to the angular momentum of nucleons removed from the projectile. The theoretical yield of low-spin states is generally overestimated. In these cases the assumption of 100% feeding of the isomer may require modification. However, the yield of high-spin isomeric states [Im ≥ (39/2)ℏ] is significantly underestimated and highlights the requirement for a more complete theoretical framework in relation to the generation of fragment angular momentum. The enhanced population of high-spin states reported here is advantageous to future studies involving isomeric beams at fragmentation facilities such as the Rikagaku Kenkyusho RI Beam Factory (Japan) and next-generation facilities at the Facility for Antiproton and Ion Research (Germany) and Facility for Rare Isotope Beams (USA).

  1. Perpendicular spin transfer torque magnetic random access memories with high spin torque efficiency and thermal stability for embedded applications (invited)

    Energy Technology Data Exchange (ETDEWEB)

    Thomas, Luc, E-mail: luc.thomas@headway.com; Jan, Guenole; Zhu, Jian; Liu, Huanlong; Lee, Yuan-Jen; Le, Son; Tong, Ru-Ying; Pi, Keyu; Wang, Yu-Jen; Shen, Dongna; He, Renren; Haq, Jesmin; Teng, Jeffrey; Lam, Vinh; Huang, Kenlin; Zhong, Tom; Torng, Terry; Wang, Po-Kang [TDK-Headway Technologies, Inc., Milpitas, California 95035 (United States)

    2014-05-07

    Magnetic random access memories based on the spin transfer torque phenomenon (STT-MRAMs) have become one of the leading candidates for next generation memory applications. Among the many attractive features of this technology are its potential for high speed and endurance, read signal margin, low power consumption, scalability, and non-volatility. In this paper, we discuss our recent results on perpendicular STT-MRAM stack designs that show STT efficiency higher than 5 k{sub B}T/μA, energy barriers higher than 100 k{sub B}T at room temperature for sub-40 nm diameter devices, and tunnel magnetoresistance higher than 150%. We use both single device data and results from 8 Mb array to demonstrate data retention sufficient for automotive applications. Moreover, we also demonstrate for the first time thermal stability up to 400 °C exceeding the requirement of Si CMOS back-end processing, thus opening the realm of non-volatile embedded memory to STT-MRAM technology.

  2. Environmentally friendly and highly productive bi-component melt spinning of thermoregulated smart polymer fibres with high latent heat capacity

    Directory of Open Access Journals (Sweden)

    Ch. Cherif

    2018-03-01

    Full Text Available A stable and reproducible bi-component melt spinning process on an industrial scale incorporating Phase Change Material (PCM into textile fibres has been successfully developed and carried out using a melt spinning machine. The key factor for a successful bi-component melt spinning process is that a deep insight into the thermal and rheological behaviour of PCM using Difference Scanning Calorimetry (DSC, Thermogravimetric Analysis (TGA, and an oscillatory rheological investigation. PCM is very sensitive to the temperature and residence time of the melt spinning process. It is found that the optimal process temperature of PCM is 210 °C. The textile-physical properties and the morphology of the melt spun and further drawn bi-component core and sheath fibres (bico fibres were investigated and interpreted. The heat capacities of PCM incorporated in bico fibres were also determined by means of DSC. The melt spun bico fibres integrating PCM provide a high latent heat of up to 22 J/g, which is three times higher than that of state-of-the-art fibres, which were also obtained using the melt spinning process. Therefore, they have the potential to be used as smart polymer fibres for textile and other technical applications.

  3. Endohedral Metallofullerene as Molecular High Spin Qubit: Diverse Rabi Cycles in Gd2@C79N.

    Science.gov (United States)

    Hu, Ziqi; Dong, Bo-Wei; Liu, Zheng; Liu, Jun-Jie; Su, Jie; Yu, Changcheng; Xiong, Jin; Shi, Di-Er; Wang, Yuanyuan; Wang, Bing-Wu; Ardavan, Arzhang; Shi, Zujin; Jiang, Shang-Da; Gao, Song

    2018-01-24

    An anisotropic high-spin qubit with long coherence time could scale the quantum system up. It has been proposed that Grover's algorithm can be implemented in such systems. Dimetallic aza[80]fullerenes M 2 @C 79 N (M = Y or Gd) possess an unpaired electron located between two metal ions, offering an opportunity to manipulate spin(s) protected in the cage for quantum information processing. Herein, we report the crystallographic determination of Gd 2 @C 79 N for the first time. This molecular magnet with a collective high-spin ground state (S = 15/2) generated by strong magnetic coupling (J Gd-Rad = 350 ± 20 cm -1 ) has been unambiguously validated by magnetic susceptibility experiments. Gd 2 @C 79 N has quantum coherence and diverse Rabi cycles, allowing arbitrary superposition state manipulation between each adjacent level. The phase memory time reaches 5 μs at 5 K by dynamic decoupling. This molecule fulfills the requirements of Grover's searching algorithm proposed by Leuenberger and Loss.

  4. Properties of neutron-rich hafnium high-spin isomers

    CERN Multimedia

    Tungate, G; Walker, P M; Neyens, G; Billowes, J; Flanagan, K; Koester, U H; Litvinov, Y

    It is proposed to study highly-excited multi-quasiparticle isomers in neutron-rich hafnium (Z=72) isotopes. Long half-lives have already been measured for such isomers in the storage ring at GSI, ensuring their accessibility with ISOL production. The present proposal focuses on:\\\\ (i) an on-line experiment to measure isomer properties in $^{183}$Hf and $^{184}$Hf, and\\\\ (ii) an off-line molecular breakup test using REXTRAP, to provide Hf$^{+}$ beams for future laser spectroscopy and greater sensitivity for the future study of more neutron-rich isotopes.

  5. Entanglement and magnetism in high-spin graphene nanodisks

    Science.gov (United States)

    Hagymási, I.; Legeza, Ö.

    2018-01-01

    We investigate the ground-state properties of triangular graphene nanoflakes with zigzag edge configurations. The description of zero-dimensional nanostructures requires accurate many-body techniques since the widely used density-functional theory with local density approximation or Hartree-Fock methods cannot handle the strong quantum fluctuations. Applying the unbiased density-matrix renormalization group algorithm we calculate the magnetization and entanglement patterns with high accuracy for different interaction strengths and compare them to the mean-field results. With the help of quantum information analysis and subsystem density matrices we reveal that the edges are strongly entangled with each other. We also address the effect of electron and hole doping and demonstrate that the magnetic properties of triangular nanoflakes can be controlled by an electric field, which reveals features of flat-band ferromagnetism. This may open up new avenues in graphene based spintronics.

  6. Spin conversion of cytochrome b559 in photosystem II induced by exogenous high potential quinone

    Science.gov (United States)

    Kropacheva, Tatyana N.; Feikema, W. Onno; Mamedov, Fikret; Feyziyev, Yashar; Styring, Stenbjorn; Hoff, Arnold J.

    2003-11-01

    The spin-state of cytochrome b559 (Cyt b559) was studied in photosystem II (PSII) membrane fragments by low-temperature EPR spectroscopy. Treatment of the membranes with 2,3-dichloro-5,6-dicyano- p-benzoquinone (DDQ) converts the native low-spin (LS) form of Cyt b559 to the high-spin (HS) form characterized with the g= 6.19 and g= 5.95 split signal. The HS Cyt b559 was pH dependent with the amplitude increasing toward more acidic pH values (pH 5.5-8.5). The HS state was not photochemically active upon 77 and 200 K continuous illumination under our conditions and was characterized by a low reduction potential (⩽0 V). It was also demonstrated that DDQ treatment damages the oxygen evolving complex, leading to inhibition of oxygen evolution, decrease of the S 2-state EPR multiline signal and release of Mn 2+. In parallel, studies of model systems containing iron(III) protoporphyrin IX chloride (Fe IIIPor), which is a good model compound for the Cyt b559 prosthetic group, were performed by using optical and EPR spectroscopy. The interaction of Fe IIIPor with imidazole (Im) in weakly polar solvent results in formation of bis-imidazole coordinated heme iron (Fe IIIPor Im 2) which mimic the bis-histidine axial ligation of Cyt b559. The reaction of DDQ with the LS Fe IIIPor Im 2 complex leads to its transformation into the HS state ( g⊥=5.95, g∥=2.00). It was shown that the spin conversion occurs due to the donor-acceptor interaction of coordinated imidazole with this high-potential quinone causing the displacement of imidazole from the axial position. The similar mechanism of DDQ-induced spin change is assumed to be valid for the native membrane Cyt b559 in PSII centers.

  7. Observation of high-spin bands with large moments of inertia in 124Xe

    Science.gov (United States)

    Nag, Somnath; Singh, A. K.; Hagemann, G. B.; Sletten, G.; Herskind, B.; Døssing, T.; Ragnarsson, I.; Hübel, H.; Bürger, A.; Chmel, S.; Wilson, A. N.; Rogers, J.; Carpenter, M. P.; Janssens, R. V. F.; Khoo, T. L.; Kondev, F. G.; Lauritsen, T.; Zhu, S.; Korichi, A.; Stefanova, E. A.; Fallon, P.; Nyakó, B. M.; Timár, J.; Juhász, K.

    2016-09-01

    High-spin states in 124Xe have been populated using the 80Se(48Ca,4 n ) reaction at a beam energy of 207 MeV and high-multiplicity, γ -ray coincidence events were measured using the Gammasphere spectrometer. Six high-spin bands with large moments of inertia, similar to those observed in neighboring nuclei, have been observed. The experimental results are compared with calculations within the framework of the cranked Nilsson-Strutinsky model. It is suggested that the configurations of the bands involve excitations of protons across the Z =50 shell gap coupled to neutrons within the N =50 -82 shell or excited across the N =82 shell closure.

  8. Vibration control of a ship engine system using high-load magnetorheological mounts associated with a new indirect fuzzy sliding mode controller

    Science.gov (United States)

    Phu, Do Xuan; Choi, Seung-Bok

    2015-02-01

    In this work, a new high-load magnetorheological (MR) fluid mount system is devised and applied to control vibration in a ship engine. In the investigation of vibration-control performance, a new modified indirect fuzzy sliding mode controller is formulated and realized. The design of the proposed MR mount is based on the flow mode of MR fluid, and it includes two separated coils for generating a magnetic field. An optimization process is carried out to achieve maximal damping force under certain design constraints, such as the allowable height of the mount. As an actuating smart fluid, a new plate-like iron-particle-based MR fluid is used, instead of the conventional spherical iron-particle-based MR fluid. After evaluating the field-dependent yield stress of the MR fluid, the field-dependent damping force required to control unwanted vibration in the ship engine is determined. Subsequently, an appropriate-sized MR mount is manufactured and its damping characteristics are evaluated. After confirming the sufficient damping force level of the manufactured MR mount, a medium-sized ship engine mount system consisting of eight MR mounts is established, and its dynamic governing equations are derived. A new modified indirect fuzzy sliding mode controller is then formulated and applied to the engine mount system. The displacement and velocity responses show that the unwanted vibrations of the ship engine system can be effectively controlled in both the axial and radial directions by applying the proposed control methodology.

  9. Nonlinear observation of internal states of fuel cell cathode utilizing a high-order sliding-mode algorithm

    Science.gov (United States)

    Xu, Liangfei; Hu, Junming; Cheng, Siliang; Fang, Chuan; Li, Jianqiu; Ouyang, Minggao; Lehnert, Werner

    2017-07-01

    A scheme for designing a second-order sliding-mode (SOSM) observer that estimates critical internal states on the cathode side of a polymer electrolyte membrane (PEM) fuel cell system is presented. A nonlinear, isothermal dynamic model for the cathode side and a membrane electrolyte assembly are first described. A nonlinear observer topology based on an SOSM algorithm is then introduced, and equations for the SOSM observer deduced. Online calculation of the inverse matrix produces numerical errors, so a modified matrix is introduced to eliminate the negative effects of these on the observer. The simulation results indicate that the SOSM observer performs well for the gas partial pressures and air stoichiometry. The estimation results follow the simulated values in the model with relative errors within ± 2% at stable status. Large errors occur during the fast dynamic processes (<1 s). Moreover, the nonlinear observer shows good robustness against variations in the initial values of the internal states, but less robustness against variations in system parameters. The partial pressures are more sensitive than the air stoichiometry to system parameters. Finally, the order of effects of parameter uncertainties on the estimation results is outlined and analyzed.

  10. WTP Pretreatment Facility Potential Design Deficiencies--Sliding Bed and Sliding Bed Erosion Assessment

    Energy Technology Data Exchange (ETDEWEB)

    Hansen, E. K. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2015-05-06

    This assessment is based on readily available literature and discusses both Newtonian and non-Newtonian slurries with respect to sliding beds and erosion due to sliding beds. This report does not quantify the size of the sliding beds or erosion rates due to sliding beds, but only assesses if they could be present. This assessment addresses process pipelines in the Pretreatment (PT) facility and the high level waste (HLW) transfer lines leaving the PT facility to the HLW vitrification facility concentrate receipt vessel.

  11. Structure of high-spin states in A {approx} 60 region

    Energy Technology Data Exchange (ETDEWEB)

    Nakada, Hitoshi [Chiba Univ. (Japan); Furutaka, K.; Hatsukawa, Y. [and others

    1998-03-01

    High-spin states in the proton-rich Cu-Zn nuclei are investigated by the experiments at JAERI. New levels and {gamma}-rays are identified by the particle-{gamma}-{gamma} coincidence, and J{sup P} assignments are made via the DCO ratio analysis. Yrast sequences are observed up to J {approx} 18 for {sup 62}Zn, and {sup 64}Zn, J {approx} 27/2 for {sup 61}Cu and J {approx} 23/2 for {sup 63}Cu. Though we cannot settle new J{sup P} values for {sup 61,63}Zn, their yrast sequence is also extended. In {sup 64}Zn, a doublet of {gamma}-rays is discovered at 1315 keV, clarifying the similarity in the level scheme between {sup 62}Zn and {sup 64}Zn. We reproduce the yrast levels by a shell-model calculation, by which structure of the high-spin states is further studied. A parity change in the yrast sequence is established, in which the unique-parity orbit 0g{sub 9/2} plays an essential role; one nucleon excitation to g{sub 9/2} gains high angular momentum with low seniority, at the cost of the single-parity energy. Second parity-change is also suggested by the calculation. Such parity change seems characteristic to spherical or nearly spherical nuclei. In {sup 61}Cu, concentration of the {gamma}-ray intensity is observed. This happens because a stretched 3-quasiparticle configuration including 0g{sub 9/2} is relatively stable, similarly to some isomers. Thus, by studying the structure of the high-spin states of the A {approx} 60 nuclei, we have clarified the role of unique-parity orbit in high-spin states, which may be generic to spherical and nearly spherical nuclei. (J.P.N.)

  12. High frequency magnetic eigen excitations in a spin valve submitted to CPP DC current

    Energy Technology Data Exchange (ETDEWEB)

    Mistral, Q. [Institut d' Electronique Fondamentale, CNRS UMR 8622, Bat 220, Universite Paris-Sud, Centre d' Orsay, F91405 Orsay Cedex (France)]. E-mail: mistral@ief.u-psud.fr; Deac, A. [SPINTEC, URA CEA/CNRS, CEA Grenoble/DRFMC, 17 Rue des Martyrs, 38054 Grenoble Cedex 9 (France); Grollier, J. [Institut d' Electronique Fondamentale, CNRS UMR 8622, Bat 220, Universite Paris-Sud, Centre d' Orsay, F91405 Orsay Cedex (France); Redon, O. [SPINTEC, URA CEA/CNRS, CEA Grenoble/DRFMC, 17 Rue des Martyrs, 38054 Grenoble Cedex 9 (France); Liu, Y. [Headway, 678 Hillview Dr., Milpitas, CA 95035 (United States); Li, M. [Headway, 678 Hillview Dr., Milpitas, CA 95035 (United States); Wang, P. [Headway, 678 Hillview Dr., Milpitas, CA 95035 (United States); Dieny, B. [SPINTEC, URA CEA/CNRS, CEA Grenoble/DRFMC, 17 Rue des Martyrs, 38054 Grenoble Cedex 9 (France); Devolder, T. [Institut d' Electronique Fondamentale, CNRS UMR 8622, Bat 220, Universite Paris-Sud, Centre d' Orsay, F91405 Orsay Cedex (France)

    2006-01-25

    We study the magnetization dynamics induced at low field by spin-transfer in a pillar-shaped spin valve. The spin valve is a square of 150 nmx 150 nm patterned from a film of IrMn 7 nm/CoFe, 2.4 nm/Ru, 0.8 nm/CoFe, 4.4 nm/Cu, 2.6 nm/CoFe, and 3.6 nm. The spin valve is studied in its anti-parallel state at 50 K. The high frequency voltage noise generated by the DC current flowing through the magneto-resistive device is used to identify the excitations induced by spin-transfer. Between an instability current of 1.72 mA and the switching current of 1.89 mA, we demonstrate the existence of pre-switch steady-state excitations, i.e. low amplitude precession. We study the frequency (10 GHz, red shift -1.46 GHz/mA) of this excitation, its line width (78-246 MHz), the power it carries (113 nW), and the current dependance thereof. We discuss those experimental findings using the formalism of Sun et al. and Valet et al., and show that the experimental behavior can be described by a macrospin approximation only at the very onset of the pre-switch excitations. The early saturation of the excitation power and the non-monotonic switching probability with the current are experimental indications that the pre-switch excitations are strongly non-uniform when approaching the switching current.

  13. Sliding Friction of Copper

    National Research Council Canada - National Science Library

    Liu, Tung

    1963-01-01

    .... With less clean surfaces, the coefficient of friction obtained was about 0.4. Since the degree of cleanliness cannot be controlled quantitatively, the friction - load curve of sliding copper pairs in air exhibits a bifurcation characteristic...

  14. Genome Engineering Workshop Slides

    OpenAIRE

    Macrae, Rhiannon

    2017-01-01

    These slides were presented at Genome Engineering 5.0, an annual workshop hosted by the Zhang Lab at the Broad Institute. They are designed to help new users get CRISPR-based tools working in their own hands.

  15. Equation-of-motion coupled cluster method for high spin double electron attachment calculations

    Energy Technology Data Exchange (ETDEWEB)

    Musiał, Monika, E-mail: musial@ich.us.edu.pl; Lupa, Łukasz; Kucharski, Stanisław A. [Institute of Chemistry, University of Silesia, Szkolna 9, 40-006 Katowice (Poland)

    2014-03-21

    The new formulation of the equation-of-motion (EOM) coupled cluster (CC) approach applicable to the calculations of the double electron attachment (DEA) states for the high spin components is proposed. The new EOM equations are derived for the high spin triplet and quintet states. In both cases the new equations are easier to solve but the substantial simplification is observed in the case of quintets. Out of 21 diagrammatic terms contributing to the standard DEA-EOM-CCSDT equations for the R{sub 2} and R{sub 3} amplitudes only four terms survive contributing to the R{sub 3} part. The implemented method has been applied to the calculations of the excited states (singlets, triplets, and quintets) energies of the carbon and silicon atoms and potential energy curves for selected states of the Na{sub 2} (triplets) and B{sub 2} (quintets) molecules.

  16. Sliding mode control and observation

    CERN Document Server

    Shtessel, Yuri; Fridman, Leonid; Levant, Arie

    2014-01-01

    The sliding mode control methodology has proven effective in dealing with complex dynamical systems affected by disturbances, uncertainties and unmodeled dynamics. Robust control technology based on this methodology has been applied to many real-world problems, especially in the areas of aerospace control, electric power systems, electromechanical systems, and robotics. Sliding Mode Control and Observation represents the first textbook that starts with classical sliding mode control techniques and progresses toward newly developed higher-order sliding mode control and observation algorithms and their applications. The present volume addresses a range of sliding mode control issues, including: *Conventional sliding mode controller and observer design *Second-order sliding mode controllers and differentiators *Frequency domain analysis of conventional and second-order sliding mode controllers *Higher-order sliding mode controllers and differentiators *Higher-order sliding mode observers *Sliding mode disturbanc...

  17. Spin-orbital nature of the high-field magnetic state in the Sr4Ru3O10

    Science.gov (United States)

    Granata, Veronica; Capogna, Lucia; Forte, Filomena; Lepetit, Marie-Bernadette; Fittipaldi, Rosalba; Stunault, Anne; Cuoco, Mario; Vecchione, Antonio

    2016-03-01

    We perform a spin-polarized neutron-diffraction study to investigate the nature of the high-field magnetic state of the trilayered Sr4Ru3O10 . The analysis indicates that a high field applied within the a b plane leads to an unbalance of the spin and orbital moments with a spatial profile that is strongly tied to the layers where the electrons are located in the unit cell. We provide evidence of a layer dependent magnetic anisotropy with the inner layers having larger spin and orbital magnetic moments than the outer ones and show that such behavior is robust to temperature variation being persistent above the Curie temperature. By means of an effective model that includes the coupling between the spin-orbital degrees of freedom at inequivalent Ru sites we ascribe the origin of the layer anisotropy to the cooperative effects between octahedral distortions, spin orbit, and Coulomb interactions.

  18. Spin-Circuit Representation of Spin Pumping

    Science.gov (United States)

    Roy, Kuntal

    2017-07-01

    Circuit theory has been tremendously successful in translating physical equations into circuit elements in an organized form for further analysis and proposing creative designs for applications. With the advent of new materials and phenomena in the field of spintronics and nanomagnetics, it is imperative to construct the spin-circuit representations for different materials and phenomena. Spin pumping is a phenomenon by which a pure spin current can be injected into the adjacent layers. If the adjacent layer is a material with a high spin-orbit coupling, a considerable amount of charge voltage can be generated via the inverse spin Hall effect allowing spin detection. Here we develop the spin-circuit representation of spin pumping. We then combine it with the spin-circuit representation for the materials having spin Hall effect to show that it reproduces the standard results as in the literature. We further show how complex multilayers can be analyzed by simply writing a netlist.

  19. Rhenium-phthalocyanine molecular nanojunction with high magnetic anisotropy and high spin filtering efficiency

    Energy Technology Data Exchange (ETDEWEB)

    Li, J. [State Key Laboratory of Surface Physics, Key Laboratory of Computational Physical Sciences, and Department of Physics, Fudan University, Shanghai 200433 (China); Institute of Nanomaterial and Nanostructure, Changsha University of Science and Technology, Changsha 410114 (China); Hu, J. [School of Physical Science and Technology, Soochow University, Suzhou, Jiangsu 215006 (China); Wang, H. [State Key Laboratory of Surface Physics, Key Laboratory of Computational Physical Sciences, and Department of Physics, Fudan University, Shanghai 200433 (China); Wu, R. Q., E-mail: wur@uci.edu [State Key Laboratory of Surface Physics, Key Laboratory of Computational Physical Sciences, and Department of Physics, Fudan University, Shanghai 200433 (China); Department of Physics and Astronomy, University of California, Irvine, California 92697-4575 (United States)

    2015-07-20

    Using the density functional and non-equilibrium Green's function approaches, we studied the magnetic anisotropy and spin-filtering properties of various transition metal-Phthalocyanine molecular junctions across two Au electrodes. Our important finding is that the Au-RePc-Au junction has both large spin filtering efficiency (>80%) and large magnetic anisotropy energy, which makes it suitable for device applications. To provide insights for the further experimental work, we discussed the correlation between the transport property, magnetic anisotropy, and wave function features of the RePc molecule, and we also illustrated the possibility of controlling its magnetic state.

  20. High-spin chloro mononuclear MnIII complexes: a multifrequency high-field EPR study.

    Science.gov (United States)

    Mantel, Claire; Chen, Hongyu; Crabtree, Robert H; Brudvig, Gary W; Pécaut, Jacques; Collomb, Marie-Noëlle; Duboc, Carole

    2005-03-01

    The isolation, structural characterization, and electronic properties of two six-coordinated chloromanganese (III) complexes, [Mn(terpy)(Cl)3] (1) and [Mn(Phterpy)(Cl)3] (2), are reported (terpy = 2,2':6'2"-terpyridine, Phterpy = 4'-phenyl-2,2':6',2"-terpyridine). These complexes complement a series of mononuclear azide and fluoride Mn(lll) complexes synthesized with neutral N-tridentate ligands, [Mn(L)(X)3] (X = F- or N3 and L = terpy or bpea [N,N-bis(2-pyridylmethyl)-ethylamine)], previously described. Similar to these previous complexes, 1 and 2 exhibit a Jahn-Teller distortion of the octahedron, characteristic of a high-spin Mn(III) complex (S = 2). The analysis of the crystallographic data shows that, in both cases, the manganese ion lies in the center of a distorted octahedron characterized by an elongation along the tetragonal axis. Their electronic properties were investigated by multifrequency EPR (190-475 GHz) performed in the solid state at different temperatures (5-15 K). This study confirms our previous results and further shows that: i) the sign of D is correlated with the nature of the tetragonal distortion; ii) the magnitude of D is not sensitive to the nature of the anions in our series of rhombic complexes, contrary to the porphyrinic systems; iii) the [E/D] values (0.124 for 1 and 0.085 for 2) are smaller compared to those found for the [Mn(L)(X)3] complexes (in the range of 0.146 to 0.234); and iv) the E term increases when the ligand-field strength of the equatorial ligands decreases.

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

    Directory of Open Access Journals (Sweden)

    P.-N. Seo

    2008-08-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2008-01-01

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

  3. Newly recognized submarine slide complexes in the southern California Bight

    Science.gov (United States)

    Conrad, J. E.; Lee, H. J.; Edwards, B. D.; McGann, M.; Sliter, R. W.

    2012-12-01

    New high-resolution bathymetric and seismic-reflection surveys have imaged large (7) individual overlapping slides along the western margin of Santa Cruz Basin (SCB slide); 2) a series of slumps and slide scars on the slope south of San Pedro shelf (SPS slide); and 3) a slope failure along the shelf edge in northern San Diego County, termed the Del Mar slide. The SCB slide complex extends for 30 km along the western slope of Santa Cruz Basin, with debris lobes extending 5-8 km into the basin. Head scarps of some of these slides are 50-75 m high. The SPS slide complex also appears to consist of multiple slides, which roughly parallel the Palos Verdes Fault and the San Gabriel Canyon submarine channel on the shelf edge and slope south of San Pedro shelf. Slide deposits associated with this complex are only partially mapped due to limited high-resolution bathymetric coverage, but extend to the south in the area SW of Lasuen Knoll. Seismic-reflection profiles show that some of these deposits are up to 20 m thick. The Del Mar slide is located about 10 km north of La Jolla Canyon and extends about 6 km along the shelf edge. The head scarp lies along the trend of a branch of the Rose Canyon Fault Zone. Radiocarbon ages of sediment overlying this slide indicate the Del Mar slide is approximately 12-16 ka. These large slide complexes have several characteristics in common. Nearly all occur in areas of tectonic uplift. All of the complexes show evidence of recurrent slide activity, exhibiting multiple headwall scarps and debris lobes, and where available, high-resolution seismic-reflection profiles of these slide areas provide evidence of older, buried mass transport deposits. Assuming typical sedimentation rates, the recurrence interval of major slide events appears to be on the order of tens of thousands of years. Most of the slide complexes do not appear to be located in areas of high sediment input. The SCB and Del Mar slides are in areas receiving relatively small

  4. Spin dephasing and photoinduced spin diffusion in a high-mobility two-dimensional electron system embedded in a GaAs-(Al,Ga)As quantum well grown in the [110] direction

    Science.gov (United States)

    Völkl, R.; Griesbeck, M.; Tarasenko, S. A.; Schuh, D.; Wegscheider, W.; Schüller, C.; Korn, T.

    2011-06-01

    We have studied spin dephasing and spin diffusion in a high-mobility two-dimensional electron system, embedded in a GaAs/AlGaAs quantum well grown in the [110] direction, by a two-beam Hanle experiment. For very low excitation density, we observe spin lifetimes of more than 16 ns, which rapidly decrease as the pump intensity is increased. Two mechanisms contribute to this decrease: The optical excitation produces holes, which lead to a decay of electron spin via the Bir-Aronov-Pikus mechanism and recombination with spin-polarized electrons. By scanning the distance between the pump and probe beams, we observe the diffusion of spin-polarized electrons over more than 20 μm. For high pump intensity, the spin polarization in a distance of several micrometers from the pump beam is larger than at the pump spot, due to the reduced influence of photogenerated holes.

  5. High-pressure, high-temperature magic angle spinning nuclear magnetic resonance devices and processes for making and using same

    Science.gov (United States)

    Hu, Jian Zhi; Hu, Mary Y.; Townsend, Mark R.; Lercher, Johannes A.; Peden, Charles H. F.

    2015-10-06

    Re-usable ceramic magic angle spinning (MAS) NMR rotors constructed of high-mechanic strength ceramics are detailed that include a sample compartment that maintains high pressures up to at least about 200 atmospheres (atm) and high temperatures up to about least about 300.degree. C. during operation. The rotor designs minimize pressure losses stemming from penetration over an extended period of time. The present invention makes possible a variety of in-situ high pressure, high temperature MAS NMR experiments not previously achieved in the prior art.

  6. PELDOR and RIDME Measurements on a High-Spin Manganese(II) Bisnitroxide Model Complex.

    Science.gov (United States)

    Meyer, Andreas; Schiemann, Olav

    2016-05-26

    A homoleptic bisnitroxide complex of manganese(II) was synthesized as a model system for EPR spectroscopic distance determinations involving high-spin metal ions and more than one distance. The performance of the RIDME experiment is compared with that of the more frequently used PELDOR experiment. It is shown that the PELDOR experiment yields both distances, Mn(II)-nitroxide and nitroxide-nitroxide, and that they can be separated to a certain extent, whereas the RIDME experiment yields only the Mn(II)-nitroxide distance. Both pulse sequences yield artifacts, either due to multispin effects or higher electron-spin transitions. Orientation selection is mostly introduced by the nitroxide signal and can be averaged out by variation of the observer field in the RIDME experiment. Thus, both methods might be used complementarily to obtain a reliable picture of an unknown system.

  7. High spin-polarization in ultrathin Co{sub 2}MnSi/CoPd multilayers

    Energy Technology Data Exchange (ETDEWEB)

    Galanakis, I., E-mail: galanakis@upatras.gr

    2015-03-01

    Half-metallic Co{sub 2}MnSi finds a broad spectrum of applications in spintronic devices either in the form of thin films or as spacer in multilayers. Using state-of-the-art ab-initio electronic structure calculations we exploit the electronic and magnetic properties of ultrathin Co{sub 2}MnSi/CoPd multilayers. We show that these heterostructures combine high values of spin-polarization at the Co{sub 2}MnSi spacer with the perpendicular magnetic anisotropy of binary compounds such as CoPd. Thus they could find application in spintronic/magnetoelectronic devices. - Highlights: • Ab-initio study of ultrathin Co{sub 2}MnSi/CoPd multilayers. • Large values of spin-polarization at the Fermi are retained. • Route for novel spintronic/magnetoelectronic devices.

  8. Spin polarization in high density quark matter under a strong external magnetic field

    DEFF Research Database (Denmark)

    Tsue, Yasuhiko; Da Providência, João; Providência, Constança

    2016-01-01

    In high density quark matter under a strong external magnetic field, possible phases are investigated by using the two-flavor Nambu-Jona-Lasinio (NJL) model with tensor-type four-point interaction between quarks, as well as the axial-vector-type four-point interaction. In the tensor......-type interaction under the strong external magnetic field, it is shown that a quark spin polarized phase is realized in all regions of the quark chemical potential under consideration within the lowest Landau level approximation. In the axial-vector-type interaction, it is also shown that the quark spin polarized...... phase appears in the wide range of the quark chemical potential. In both the interactions, the quark mass in zero and small chemical potential regions increases which indicates that the chiral symmetry breaking is enhanced, namely the magnetic catalysis occurs....

  9. Strongly Deformed Nuclear Shapes at Ultra-High Spin and Shape Coexistence in Nsim 90 Nuclei

    Science.gov (United States)

    Riley, M. A.; Aguilar, A.; Evans, A. O.; Hartley, D. J.; Lagergren, K.; Ollier, J.; Paul, E. S.; Pipidis, A.; Simpson, J.; Teal, C.; Twin, P. J.; Wang, X.; Appelbe, D. E.; Campbell, D. B.; Carpenter, M. P.; Clark, R. M.; Cromaz, M.; Darby, I. G.; Fallon, P.; Garg, U.; Janssens, R. V. F.; Joss, D. T.; Kondev, F. G.; Lauritsen, T.; Lee, I. Y.; Lister, C. J.; Macchiavelli, A. O.; Nolan, P. J.; Petri, M.; Rigby, S. V.; Thompson, J.; Unsworth, C.; Ward, D.; Zhu, S.; Ragnarsson, I.

    2009-03-01

    The N sim 90 region of the nuclear chart has featured prominently as the spectroscopy of nuclei at extreme spin has progressed. This talk will present recent discoveries from investigations of high spin behavior in the N sim 90 Er, Tm and Yb nuclei utilizing the Gammasphere gamma-ray spectrometer. In particular it will include discussion of the beautiful shape evolution and coexistence observed in these nuclei along with the identification of a remarkable new family of band structures. The latter are very weakly populated rotational sequences with high moment of inertia that bypass the classic terminating configurations near spin 40-50 hbar, marking a return to collectivity that extends discrete gamma -ray spectroscopy to well over 60 hbar. Establishing the nature of the yrast states in these nuclei beyond the oblate band-termination states has been a major goal for the past two decades. Cranking calculations suggest that these new structures most likely represent stable triaxial strongly deformed bands that lie in a valley of favored shell energy in deformation and particle-number space.

  10. Sliding mode control for synchronous electric drives

    CERN Document Server

    Ryvkin, Sergey E

    2011-01-01

    This volume presents the theory of control systems with sliding mode applied to electrical motors and power converters. It demonstrates the methodology of control design and the original algorithms of control and observation. Practically all semiconductor devices are used in power converters, that feed electrical motors, as power switches. A switching mode offers myriad attractive, inherent properties from a control viewpoint, especially a sliding mode. Sliding mode control supplies high dynamics to systems, invariability of systems to changes of their parameters and of exterior loads in combi

  11. Metal-biradical chains from a high-spin ligand and bis(hexafluoroacetylacetonato)copper(II).

    Science.gov (United States)

    Rajadurai, Chandrasekar; Enkelmann, Volker; Ikorskii, Vladimir; Ovcharenko, Victor I; Baumgarten, Martin

    2006-11-27

    The synthesis, X-ray crystal structure, and magnetic studies of a rare example of organic/inorganic spin hybrid clusters extended in infinite ladder-type chain [Cu(C5F6HO2)2]7(C35H35N5O4)2 ([Cu(hfac)2]7(pyacbisNN)2, 2) formed by the reaction of a high spin nitronylnitroxide biradical C35H35N5O4 (pyacbisNN, 1) and bis(hexafluroacetylacetonate)copper(II) = Cu(hfac)2 are described. Single-crystal X-ray structure analysis revealed the triclinic P1 space group of 2 with the following parameters: a = 10.6191(4) A, b = 19.6384(7) A, c = 21.941(9) A, alpha = 107.111(7) degrees, beta = 95.107(8) degrees, gamma = 94.208(0) degrees , Z = 2. Each repeating unit in 2 carries a centrosymmetric cyclic six spin and a linear five spin cluster with four different copper coordination environments having octahedral and square planar geometries. These clusters are interconnected to form infinite chains which are running along the crystallographic b axis. The magnetic measurements show nearly paramagnetic behavior with very small variations over a large temperature range. The magnetic properties are thus result of complex competitions of many weak ferro- and antiferromagnetic interactions, which appear as small deviations from quite linear mu(eff) vs T dependence at low temperature. At high temperature (300-14 K), antiferromagnetic behavior dominates a little, while at very low temperature (14-2 K), a small increase of mu(eff) was observed. The magnetic susceptibility data are described by the Curie-Weiss law [chi = C/(T - theta)] with the optimal parameters C = 4.32 +/- 0.01 emuK/mol and theta = - 0.6 +/- 0.3 K, where C is the Curie constant and theta is the Weiss temperature.

  12. Ultrathin Epitaxial Ferromagneticγ-Fe2O3Layer as High Efficiency Spin Filtering Materials for Spintronics Device Based on Semiconductors

    KAUST Repository

    Li, Peng

    2016-06-01

    In spintronics, identifying an effective technique for generating spin-polarized current has fundamental importance. The spin-filtering effect across a ferromagnetic insulating layer originates from unequal tunneling barrier heights for spin-up and spin-down electrons, which has shown great promise for use in different ferromagnetic materials. However, the low spin-filtering efficiency in some materials can be ascribed partially to the difficulty in fabricating high-quality thin film with high Curie temperature and/or partially to the improper model used to extract the spin-filtering efficiency. In this work, a new technique is successfully developed to fabricate high quality, ferrimagnetic insulating γ-Fe2O3 films as spin filter. To extract the spin-filtering effect of γ-Fe2O3 films more accurately, a new model is proposed based on Fowler–Nordheim tunneling and Zeeman effect to obtain the spin polarization of the tunneling currents. Spin polarization of the tunneled current can be as high as −94.3% at 2 K in γ-Fe2O3 layer with 6.5 nm thick, and the spin polarization decays monotonically with temperature. Although the spin-filter effect is not very high at room temperature, this work demonstrates that spinel ferrites are very promising materials for spin injection into semiconductors at low temperature, which is important for development of novel spintronics devices. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

  13. Highly efficient polymer solar cells with printed photoactive layer: rational process transfer from spin-coating

    KAUST Repository

    Zhao, Kui

    2016-09-05

    Scalable and continuous roll-to-roll manufacturing is at the heart of the promise of low-cost and high throughput manufacturing of solution-processed photovoltaics. Yet, to date the vast majority of champion organic solar cells reported in the literature rely on spin-coating of the photoactive bulk heterojunction (BHJ) layer, with the performance of printed solar cells lagging behind in most instances. Here, we investigate the performance gap between polymer solar cells prepared by spin-coating and blade-coating the BHJ layer for the important class of modern polymers exhibiting no long range crystalline order. We find that thickness parity does not always yield performance parity even when using identical formulations. Significant differences in the drying kinetics between the processes are found to be responsible for BHJ nanomorphology differences. We propose an approach which benchmarks the film drying kinetics and associated BHJ nanomorphology development against those of the champion laboratory devices prepared by spin-coating the BHJ layer by adjusting the process temperature. If the optimization requires the solution concentration to be changed, then it is crucial to maintain the additive-to-solute volume ratio. Emulating the drying kinetics of spin-coating is also shown to help achieve morphological and performance parities. We put this approach to the test and demonstrate printed PTB7:PC71BM polymer solar cells with efficiency of 9% and 6.5% PCEs on glass and flexible PET substrates, respectively. We further demonstrate performance parity for two other popular donor polymer systems exhibiting rigid backbones and absence of a long range crystalline order, achieving a PCE of 9.7%, the highest efficiency reported to date for a blade coated organic solar cell. The rational process transfer illustrated in this study should help the broader and successful adoption of scalable printing methods for these material systems.

  14. TOPICAL REVIEW: Highly spin-polarized materials and devices for spintronics

    Directory of Open Access Journals (Sweden)

    Koichiro Inomata et al.

    2008-01-01

    Full Text Available The performance of spintronics depends on the spin polarization of the current. In this study half-metallic Co-based full-Heusler alloys and a spin filtering device (SFD using a ferromagnetic barrier have been investigated as highly spin-polarized current sources. The multilayers were prepared by magnetron sputtering in an ultrahigh vacuum and microfabricated using photolithography and Ar ion etching. We investigated two systems of Co-based full-Heusler alloys, Co2Cr1 ? xFexAl (CCFA(x and Co2FeSi1 ? xAlx (CFSA(x and revealed the structure and magnetic and transport properties. We demonstrated giant tunnel magnetoresistance (TMR of up to 220% at room temperature and 390% at 5 K for the magnetic tunnel junctions (MTJs using Co2FeSi0.5Al0.5 (CFSA(0.5 Heusler alloy electrodes. The 390% TMR corresponds to 0.81 spin polarization for CFSA(0.5 at 5 K. We also investigated the crystalline structure and local structure around Co atoms by x-ray diffraction (XRD and nuclear magnetic resonance (NMR analyses, respectively, for CFSA films sputtered on a Cr-buffered MgO (001 substrate followed by post-annealing at various temperatures in an ultrahigh vacuum. The disordered structures in CFSA films were clarified by NMR measurements and the relationship between TMR and the disordered structure was discussed. We clarified that the TMR of the MTJs with CFSA(0.5 electrodes depends on the structure, and is significantly higher for L21 than B2 in the crystalline structure. The second part of this paper is devoted to a SFD using a ferromagnetic barrier. The Co ferrite is investigated as a ferromagnetic barrier because of its high Curie temperature and high resistivity. We demonstrate the strong spin filtering effect through an ultrathin insulating ferrimagnetic Co-ferrite barrier at a low temperature. The barrier was prepared by the surface plasma oxidization of a CoFe2 film deposited on a MgO (001 single crystal substrate, wherein the spinel structure of CoFe2O4 (CFO

  15. Monitoring and data acquisition of the high speed hydrogen pellet in SPINS

    Energy Technology Data Exchange (ETDEWEB)

    Mukherjee, Samiran Shanti, E-mail: samiran@ipr.res.in; Mishra, Jyotishankar; Gangradey, Ranjana; Dutta, Pramit; Rastogi, Naveen; Panchal, Paresh; Nayak, Pratik; Agarwal, Jyoti; Bairagi, Pawan; Patel, Haresh; Sharma, Hardik

    2016-11-15

    Highlights: • Pellet INjector System with monitoring and data acquisition is described. • A high speed camera was used to view pellet size, and its flight trajectory. • PXI based high speed control system is used data acquisition. • Pellets of length 2–4.8 mm and speed 250–750 m/s were obtained. - Abstract: Injection of solid hydrogen pellets is an efficient way of replenishing the spent fuel in high temperature plasmas. Aiming that, a Single Pellet INjector System (SPINS) is developed at Institute for Plasma Research (IPR), India, to initiate pellet injection related research in SST-1. The pellet injector is controlled by a PXI system based data acquisition and control (DAC) system for pellet formation, precise firing control, data collection and diagnostics. The velocity of high speed moving pellets is estimated by using two sets of light gate diagnostic. Apart from light gate, a fast framing camera is used to measure the pellet size and its speed. The pellet images are captured at a frame rate of ∼200,000 frames per second at (128 × 64) pixel resolution with an exposure time of 1 μs. Using these diagnostic, various cylindrical pellets of length ranging from 2 to 4.8 mm and speed 250–750 m/s were successfully obtained. This paper describes the control and data acquisition system of SPINS, the techniques for measurement of pellet velocity and capturing images of high speed moving pellet.

  16. Octupole shapes and shape changes at high spins in the Z approx 58, N approx 88 nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Nazarewicz, W. (Department of Physics, Florida State University, Tallahassee, Florida 32306 (United States) Joint Institute for Heavy Ion Research, Holifield Heavy Ion Research Facility, P.O. Box 2008, Oak Ridge, Tennessee 37831 (United States)); Tabor, S.L. (Department of Physics, Florida State University, Tallahassee, Florida 32306 (United States))

    1992-05-01

    The shapes of rotating Xe, Ba, Ce, Nd, and Sm nuclei (84{le}{ital N}{le}94) are calculated using the cranking model with the Woods-Saxon average potential and pairing. The lightest isotopes of Xe and Ba have nearly spherical ground states, but develop octupole and quadrupole deformations under rotation which remain up to very high spins. The ground states of the heavier isotopes have octupole and quadrupole deformations which persist up to medium spins ({ital I}{approx}12{h bar}). At higher spins, a shape transition is predicted to reflection-symmetric aligned many-quasiparticle configurations.

  17. Solution spinning of high-? oxide superconductors: part VII. The effect of polyvinyl alcohol spinning medium on the sintering of ? superconducting filaments

    Science.gov (United States)

    Tomita, Hisayo; Goto, Tomoko; Takahashi, Kiyohisa

    1996-05-01

    As basic research for the solution spinning of high-0953-2048/9/5/005/img8 oxide superconductor, the effect of poly(vinyl alcohol) (PVA) spinning medium on the sintering of 0953-2048/9/5/005/img9 filament was examined. A precursor filament was produced by dry-spinning starting from a homogeneous aqueous PVA solution of Y, Ba and Cu acetates. The as-drawn filament was pyrolysed to remove volatile components and sintered to generate a superconducting phase. The degree of polymerization (DP) of PVA and the content of acetates in the precursor filament affected the 0953-2048/9/5/005/img10 of the sintered filament. Although most filaments exhibited high 0953-2048/9/5/005/img10 greater than 0953-2048/9/5/005/img12 at 77 K and 0 T, superconductivity above 77 K was not observed for the filament spun from PVA solution of DP=2450 with [acetates]/[PVA]=2 and sintered at 900 and 0953-2048/9/5/005/img13C for 15 min. The filament had a dense structure due to liquid phase sintering. The filament with high 0953-2048/9/5/005/img10 had a skin - core structure, and the highest 0953-2048/9/5/005/img10 of 0953-2048/9/5/005/img16 at 77 K and 0 T was attained for the filament from DP=3500 with [acetates]/[PVA]=4.

  18. Resonance Raman frequencies and core size for low- and high-spin nickel porphyrins

    Energy Technology Data Exchange (ETDEWEB)

    Kim, D.; Su, Y.O.; Spiro, T.G.

    1986-10-22

    Resonance Raman (RR) spectra are reported with B- and Q-band excitation for nickel(II) complexes of octaethylporphyrin (OEP), protoporphyrin IX dimethyl ester (PP), and meso-tetraphenylporphine (TPP) in methylene chloride (4-coordinate, low spin) and piperidine (pip) (6-coordinate, high spin). The large core size expansion accompanying the formation of the 6-coordinate species (1.96-2.04 A) is reflected in large decreases, up to 40 cm/sup -1/ in the positions of high-frequency porphyrin skeletal modes. For NiOEP and NiPP, these are in near-quantitative accord with the core size correlations obtained previously for iron porphyrin complexes, although certain deviations due to differential coupling with the vinyl modes of protoporphyrin are noted. Contributions of a minority 5-coordinate complex to the RR spectrum of NiTPP in piperidine, previously noted on the basis of photolysis effects, are evaluated quantitatively from titration data. Formation of a monopiperidine adduct, detected previously via a RR study of NiTPP(pip)/sub 2/ photolysis, is examined for nickel meso-tetrakis(p-cyanophenyl)porphine. Equilibrium constants for successive addition of piperidine ligands, K/sub 1/ = 0.4 and K/sub 2/ = 2.5 M/sup -1/, are evaluated from optical titration data, and the absorptivities of the 5- and 6-coordinate species are found to be nearly the same, consistent with both having a high-spin configuration. The frequency of the 5-coordinate nu/sub 4/ RR band is likewise found to be much closer to the 6-coordinate than to the 4-coordinate frequency.

  19. Spin-on metal oxide materials with high etch selectivity and wet strippability

    Science.gov (United States)

    Yao, Huirong; Mullen, Salem; Wolfer, Elizabeth; McKenzie, Douglas; Rahman, Dalil; Cho, JoonYeon; Padmanaban, Munirathna; Petermann, Claire; Hong, SungEun; Her, YoungJun

    2016-03-01

    Metal oxide or metal nitride films are used as hard mask materials in semiconductor industry for patterning purposes due to their excellent etch resistances against the plasma etches. Chemical vapor deposition (CVD) or atomic layer deposition (ALD) techniques are usually used to deposit the metal containing materials on substrates or underlying films, which uses specialized equipment and can lead to high cost-of-ownership and low throughput. We have reported novel spin-on coatings that provide simple and cost effective method to generate metal oxide films possessing good etch selectivity and can be removed by chemical agents. In this paper, new spin-on Al oxide and Zr oxide hard mask formulations are reported. The new metal oxide formulations provide higher metal content compared to previously reported material of specific metal oxides under similar processing conditions. These metal oxide films demonstrate ultra-high etch selectivity and good pattern transfer capability. The cured films can be removed by various chemical agents such as developer, solvents or wet etchants/strippers commonly used in the fab environment. With high metal MHM material as an underlayer, the pattern transfer process is simplified by reducing the number of layers in the stack and the size of the nano structure is minimized by replacement of a thicker film ACL. Therefore, these novel AZ® spinon metal oxide hard mask materials can potentially be used to replace any CVD or ALD metal, metal oxide, metal nitride or spin-on silicon-containing hard mask films in 193 nm or EUV process.

  20. Spin-symmetry conversion and internal rotation in high J molecular systems

    Science.gov (United States)

    Mitchell, Justin; Harter, William

    2006-05-01

    Dynamics and spectra of molecules with internal rotation or rovibrational coupling is approximately modeled by rigid or semi-rigid rotors with attached gyroscopes. Using Rotational Energy (RE)^1 surfaces, high resolution molecular spectra for high angular momentum show two distinct but related phenomena; spin-symmetry conversion and internal rotation. For both cases the high total angular momentum allows for transitions that would otherwise be forbidden. Molecular body-frame J-localization effects associated with tight energy level-clusters dominate the rovibronic spectra of high symmetry molecules, particularly spherical tops at J>10. ^2 The effects include large and widespread spin-symmetry mixing contrary to conventional wisdom^3 about weak nuclear moments. Such effects are discussed showing how RE surface plots may predict them even at low J. Classical dynamics of axially constrained rotors are approximated by intersecting rotational-energy-surfaces (RES) that have (J-S).B.(J-S) forms in the limit of constraints that do no work. Semi-classical eigensolutions are compared to those found by direct diagonalization. ^1 W.G Hater, in Handbook of Atomic, Molecular and Optical Physics, edited by G.W.F Drake (Springer, Germany 2006) ^2 W. G. Harter, Phys. Rev. A24,192-262(1981). ^3 G. Herzberg, Infrared and Raman Spectra (VanNostrand 1945) pp. 458,463.

  1. RHIC SPIN FLIPPER

    Energy Technology Data Exchange (ETDEWEB)

    BAI,M.; ROSER, T.

    2007-06-25

    This paper proposes a new design of spin flipper for RHIC to obtain full spin flip with the spin tune staying at half integer. The traditional technique of using an rf dipole or solenoid as spin flipper to achieve full spin flip in the presence of full Siberian snake requires one to change the snake configuration to move the spin tune away from half integer. This is not practical for an operational high energy polarized proton collider like RHIC where beam lifetime is sensitive to small betatron tune change. The design of the new spin flipper as well as numerical simulations are presented.

  2. High precision measurements of the neutron spin structure in Hall A at Jlab

    Energy Technology Data Exchange (ETDEWEB)

    Annand, R M; Cates, G; Cisbani, E; Franklin, G B; Liyanage, N; Puckett, A; Rosner, G; Wojtsekhowski, B

    2012-04-01

    Conclusions of this presentation are: (1) JLab energy upgrade will offer new exciting opportunities to study the nucleon (spin) structure such as high precision, unexplored phase space, flavor decomposition; (2) Large technological efforts is in progress to optimally exploit these opportunities; (3) HallA will be the first hall to get the new beam, first experiment expected to run in 2014; (4) A1n likely one of the first experiments to take data in the new 12 GeV era; and (5) SIDIS exp. will follow in couple of years.

  3. High spin states above the 28{sup {minus}} isomer in {sup 152}Ho

    Energy Technology Data Exchange (ETDEWEB)

    Rizzutto, M.A.; Ribas, R.V.; Cybulska, E.W.; Oliveira, J.R.; Zahn, G.S.; Medina, N.H. [Instituto de Fisica, Universidade de Sao Paulo, Sao Paulo (Brazil); Bazzacco, D.; Medina, N.H.; Brandolini, F.; Burch, R.; Lunardi, S.; Pavan, P.; Alvarez, C.R. [Dipartimento di Fisica and INFN, Sezione di Padova, Padova (Italy); Spolaore, P. [INFN, Laboratori Nazionali di Legnaro (Italy)

    1997-03-01

    The structure of the high spin states above the 28{sup {minus}} isomer in the odd-odd {sup 152}Ho nucleus was investigated using the GASP {gamma}-ray spectrometer coupled to the recoil mass spectrometer CAMEL. The {sup 152}Ho nucleus was populated through the {sup 120}Sn({sup 37}Cl,5n) fusion reaction at a beam energy of 187 MeV. A complex level scheme above that isomer was established up to an excitation energy of 13 MeV and I{approx} 40{h_bar}. No rotational bands were observed. {copyright} {ital 1997} {ital The American Physical Society}

  4. Configuration assignments of yrare high-spin structures in sup 1 sup 2 sup 6 Cs

    CERN Document Server

    Li, X F; Lu, J B; Zhao, G Y; Yin, L C; Meng, R; Zhang, Z L; Wen, L J; Liu, Y Z; Zhou, X H; Guo, Y X; Lei, X G; Liu, Z; Zheng, Y; He, J J

    2003-01-01

    High-spin states in sup 1 sup 2 sup 6 Cs were populated in the reaction sup 1 sup 1 sup 6 Cd( sup 1 sup 4 N,4n) at a beam energy of 65 MeV. About 50 new transitions were placed in a level scheme that consists of six rotational structures, three of which have been observed for the first time. The newly observed bands and a previously reported but uninterpreted band were assigned configurations based on their population, aligned angular momentum, energy signature splitting and B(M1)/B(E2) ratios (for the strongly coupled bands). (orig.)

  5. Atomic masses above /sup 146/Gd derived from a shell model analysis of high spin states

    CERN Document Server

    Blomqvist, J; Daly, P J; Kleinheinz, P

    1981-01-01

    Using extensive spectroscopic data on high spin states involving aligned valence nucleons in very neutron deficient nuclei above /sup 146/Gd the authors have derived the ground state masses of /sup 146 /Gd, /sup 147,148/Tb, /sup 148,149,150/Dy, /sup 149,150,151/Ho, and /sup 150,151,152/Er from a shell model analysis. The mass values show a pronounced irregularity in the two-proton separation energies at /sup 146/Gd. The results also link nine alpha -decay chains to the known masses. (0 refs).

  6. Spin crossover and Mott—Hubbard transition under high pressure and high temperature in the low mantle of the Earth

    Science.gov (United States)

    Ovchinnikov, S. G.; Ovchinnikova, T. M.; Plotkin, V. V.; Dyad'kov, P. G.

    2015-11-01

    Effect of high pressure induced spin crossover on the magnetic, electronic and structural properties of the minerals forming the Earth's low mantle is discussed. The low temperature P, T phase diagram of ferropericlase has the quantum phase transition point Pc = 56 GPa at T = 0 confirmed recently by the synchrotron Mössbauer spectroscopy. The LDA+GTB calculated phase diagram describes the experimental data. Its extension to the high temperature resulted earlier in prediction of the metallic properties of the Earth's mantle at the depth 1400 km insulator transition and compare them with the experimental seismic and geomagnetic field data.

  7. Estimating mass-wasting processes in active earth slides – earth flows with time-series of High-Resolution DEMs from photogrammetry and airborne LiDAR

    Directory of Open Access Journals (Sweden)

    A. Corsini

    2009-03-01

    Full Text Available This paper deals with the use of time-series of High-Resolution Digital Elevation Models (HR DEMs obtained from photogrammetry and airborne LiDAR coupled with aerial photos, to analyse the magnitude of recently reactivated large scale earth slides – earth flows located in the northern Apennines of Italy. The landslides underwent complete reactivation between 2001 and 2006, causing civil protection emergencies. With the final aim to support hazard assessment and the planning of mitigation measures, high-resolution DEMs are used to identify, quantify and visualize depletion and accumulation in the slope resulting from the reactivation of the mass movements. This information allows to quantify mass wasting, i.e. the amount of landslide material that is wasted during reactivation events due to stream erosion along the slope and at its bottom, resulting in sediment discharge into the local fluvial system, and to assess the total volumetric magnitude of the events. By quantifying and visualising elevation changes at the slope scale, results are also a valuable support for the comprehension of geomorphological processes acting behind the evolution of the analysed landslides.

  8. Optimal control of fast and high-fidelity quantum state transfer in spin-1/2 chains

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Xiong-Peng [School of Physics, Beijing Institute of Technology, Beijing 100081 (China); Shao, Bin, E-mail: sbin610@bit.edu.cn [School of Physics, Beijing Institute of Technology, Beijing 100081 (China); Hu, Shuai; Zou, Jian [School of Physics, Beijing Institute of Technology, Beijing 100081 (China); Wu, Lian-Ao [Department of Theoretical Physics and History of Science, The Basque Country University (EHU/UPV), PO Box 644, 48080 Bilbao (Spain); Ikerbasque, Basque Foundation for Science, 48011 Bilbao (Spain)

    2016-12-15

    Spin chains are promising candidates for quantum communication and computation. Using quantum optimal control (OC) theory based on the Krotov method, we present a protocol to perform quantum state transfer with fast and high fidelity by only manipulating the boundary spins in a quantum spin-1/2 chain. The achieved speed is about one order of magnitude faster than that is possible in the Lyapunov control case for comparable fidelities. Additionally, it has a fundamental limit for OC beyond which optimization is not possible. The controls are exerted only on the couplings between the boundary spins and their neighbors, so that the scheme has good scalability. We also demonstrate that the resulting OC scheme is robust against disorder in the chain.

  9. High spin levels populated in multinucleon-transfer reactions with 480 MeV /sup 12/C

    Energy Technology Data Exchange (ETDEWEB)

    Kraus, L.; Boucenna, A.; Linck, I.; Lott, B.; Rebmeister, R.; Schulz, N.; Sens, J.C.; Mermaz, M.C.; Berthier, B.; Lucas, R.; and others

    1988-06-01

    Two- and three-nucleon stripping reactions induced by 480 MeV /sup 12/C have been studied on /sup 12/C, /sup 16/O, /sup 28/Si, /sup 40/Ca, and /sup 54/Fe target nuclei. Discrete levels are fed with cross sections up to 1 mbsr for d-transfer reactions and 1 order and 2 orders of magnitude less for 2p- and /sup 3/He-transfer reactions, respectively. These reactions preferentially populate high spin states with stretched configurations. Several spin assignments were known from transfer reactions induced by lighter projectiles at incident energies well above the Coulomb barrier. In the case of two-nucleon transfer reactions, the energy of these states is well reproduced by crude shell model calculations. Such estimates are of use in proposing spins of newly observed states especially as the shapes of the measured angular distributions are independent of the final spin of the residual nucleus.

  10. High-spin states and lifetime measurements in sup 1 sup 7 sup 1 Hf

    CERN Document Server

    Cullen, D M; Appelbe, D E; Wilson, A N; Paul, E S; Bergström, M H; Sharpey-Schafer, J F; Baktash, C; Frosch, I; Lee, I Y; Macchiavelli, A O; MacLeod, R W; Prevost, D; Theisen, C; Curien, D

    2000-01-01

    This paper describes the results of two complementary experiments which studied the properties of the well-deformed nucleus sup 1 sup 7 sup 1 Hf. The first experiment, with a thin self-supporting target, extended the rotational bands built upon the [633]7/2, [512]5/2 and [521]1/2 configurations up to spins of 73/2-85/2 Planck constant. The configurations of these bands and observed band crossings are discussed within the framework of the cranked-shell model. The second experiment employed a backed target in order to measure the lifetimes, by the Doppler Shift Attenuation method, and thereby establish deformations for some of the states in the collective rotational bands. The extracted deformations are found to be consistent with those predicted from theoretical Total Routhian Surface calculations. These deformations provide strong evidence that the high-spin states in sup 1 sup 7 sup 1 Hf, and perhaps more importantly, in the region where the high-K (K suppi=19/2 sup + and K suppi=23/2 sup -) isomeric states ...

  11. Beta decay of medium and high spin isomers in sup 9 sup 4 Ag

    CERN Document Server

    La Commara, M; Döring, J; Galanopoulos, S; Grawe, H; Harissopoulos, S V; Hellström, M; Janas, Z; Kirchner, R; Mazzocchi, C; Ostrowski, A N; Plettner, C; Rainovski, G; Roeckl, E; Schmidt, K

    2002-01-01

    The very neutron-deficient isotope sup 9 sup 4 Ag was produced at the GSI on-line mass separator by using the reaction sup 5 sup 8 Ni( sup 4 sup 0 Ca, p3n). The beta-decay properties of sup 9 sup 4 Ag were studied by detecting for the first time beta-delayed gamma rays and beta-gamma-gamma coincidences. Both the population of excited levels in the daughter nucleus sup 9 sup 4 Pd and the beta-decay half-life of sup 9 sup 4 Ag were investigated. The major part of the feeding was assigned to the decay of an I suppi=(7 sup +) isomer with a half-life of (0.36+-0.03) s. A weak beta-decay branch was found to populate high-spin levels in the sup 9 sup 4 Pd daughter with I>=18. It is tentatively assigned to the decay of a high-spin parent state in sup 9 sup 4 Ag with I>=17 and a half-life (0.3+-0.2) s. The measured beta-decay properties as well as the level structure of sup 9 sup 4 Ag and sup 9 sup 4 Pd are discussed in comparison with shell-model predictions.

  12. Study of spin-exchange optically pumped 3He cells with high polarisation and long lifetimes

    Science.gov (United States)

    Parnell, S. R.; Babcock, E.; Nünighoff, K.; Skoda, M. W. A.; Boag, S.; Masalovich, S.; Chen, W. C.; Georgii, R.; Wild, J. M.; Frost, C. D.

    2009-01-01

    We present a detailed investigation into 3He neutron spin filter cells polarised by spin exchange optical pumping (SEOP). We include measurements of the absolute 3He polarisation using neutron transmission and characterisation of both the X-factor and 3He relaxation times ( T1) for a number of cells. For one cell we calculated a maximum 3He polarisation of 79% with a T1 of 633 h. The measured X-factor of this cell, X=0.17±0.01, is low. For all cells polarisations of >71% are observed. In addition we present 3He relaxation data for a new design of magneto-static cavity with a field of high homogeneity ΔB/B0≈3.5×10-4 cm-1. This compact device provides a magnetic field in an orientation suitable for in situ optical pumping that minimises the field inhomogeneity contribution to the T1 to 930 h in a 1 bar cell, the longest reported on beam thus far. The results suggest that high 3He polarisation with long relaxation times can now be routinely obtained with SEOP, enabling time independent incident beam polarisation to be easily implemented across many different neutron scattering instruments.

  13. High-spin states and lifetime measurements in {sup 171}Hf

    Energy Technology Data Exchange (ETDEWEB)

    Cullen, D.M.; Reed, A.T.; Appelbe, D.E.; Wilson, A.N.; Paul, E.S.; Bergstroem, M.H.; Sharpey-Schafer, J.F.; Baktash, C.; Frosch, I.; Lee, I.Y.; Macchiavelli, A.O.; MacLeod, R.W.; Prevost, D.; Theisen, Ch.; Curien, D

    2000-06-19

    This paper describes the results of two complementary experiments which studied the properties of the well-deformed nucleus {sup 171}Hf. The first experiment, with a thin self-supporting target, extended the rotational bands built upon the [633]7/2, [512]5/2 and [521]1/2 configurations up to spins of 73/2-85/2{Dirac_h}. The configurations of these bands and observed band crossings are discussed within the framework of the cranked-shell model. The second experiment employed a backed target in order to measure the lifetimes, by the Doppler Shift Attenuation method, and thereby establish deformations for some of the states in the collective rotational bands. The extracted deformations are found to be consistent with those predicted from theoretical Total Routhian Surface calculations. These deformations provide strong evidence that the high-spin states in {sup 171}Hf, and perhaps more importantly, in the region where the high-K (K{sup {pi}}=19/2{sup +} and K{sup {pi}}=23/2{sup -}) isomeric states decay, retain their well-deformed axial symmetry.

  14. Preparation of CNTs rope by electrostatic and airflow field carding with high speed rotor spinning

    Science.gov (United States)

    Dai, J. F.; Liu, J. F.; Zou, J. T.; Dai, Y. L.

    2015-12-01

    The large-scale preparation of disorderly CNTs with a length larger than 3 mm using CVD method were aligned in polymer monomer airflow fields in a quartz tube with an internal diameter of 200 μm and a length of 1.5 m. The airflow aligned CNTs at the output end of the pipe connects to a copper nozzle with an electrostatic field of applied voltage 5x105 V/m and space length of 0.03 m, which were further realigned using via electrostatic spinning. End to end spray into the high speed rotor twisted single-stranded carbon nanotubes threads via rotor spinning technology. The essential component of this technique was the use of carbon nanotubes at a high rotory speed (200000 r/min) combined with the double twisting of filaments that were twisted together to increase the radial friction of the entire section. SEM micrography showed that carbon nanotube thread has a uniform diameter of approximately 200 μm. Its tensile strength was tested up to 2.7 Gpa, with a length of several meters.

  15. Fabrication of highly oriented nanoporous fibers via airflow bubble-spinning

    Science.gov (United States)

    Liu, Fujuan; Li, Shaokai; Fang, Yue; Zheng, Fangfang; Li, Junhua; He, Jihuan

    2017-11-01

    Highly oriented Poly(lactic acid) (PLA) nanofibers with nanoporous structures has been successfully fabricated via airflow bubble-spinning without electrostatic hazard. In this work, the volatile solvent was necessary for preparing the nanoporous fiber, which was attributed to the competition between phase separation and solvent evaporation. The interconnected porous structures were affected by the processing variables of solution concentration, airflow temperature, collecting distance and relative humidity (RH). Besides, the rheological properties of solutions were studied and the highly oriented PLA nanofibers with nanoporous structure were also completely characterized using scanning electron microscope (SEM). This study provided a novel technique that successfully gets rid of the potential safety hazards caused by unexpected static to prepare highly oriented nanoporous fibers, which would demonstrate an impressive prospect for the fields of adsorption and filtration.

  16. High Resolution Magic Angle Spinning 1H-NMR Metabolic Profiling of Nanoliter Biological Tissues at High Magnetic Field

    Energy Technology Data Exchange (ETDEWEB)

    Feng, Ju; Hu, Jian Z.; Burton, Sarah D.; Hoyt, David W.

    2013-03-05

    It is demonstrated that a high resolution magic angle spinning 1H-NMR spectrum of biological tissue samples with volumes as small as 150 nanoliters, or 0.15 mg in weight, can be acquired in a few minutes at 21.1 T magnetic field using a commercial 1.6 mm fast-MAS probe with minor modification of the MAS rotor. The strategies of sealing the samples inside the MAS rotor to avoid fluid leakage as well as the ways of optimizing the signal to noise are discussed.

  17. Glass slides functionalized by 1-carboxyethyl-3-methylimidazolium chloride for the determination of triazine herbicides in rice using high-performance liquid chromatography.

    Science.gov (United States)

    Li, Xinpei; Wei, Shigang; Sun, Ying; Sun, Qun; Liang, Li; Zhang, Bo; Piao, Huilan; Song, Daqian; Wang, Xinghua

    2016-12-01

    A novel and simple supported ionic-liquid-based solid-phase extraction method for the determination of triazine herbicides in rice was developed. Glass slides were functionalized by an ionic liquid, 1-carboxyethyl-3-methylimidazolium chloride, and were used for the simultaneous extraction of seven triazine herbicides in rice samples. The effects of the type of extraction solvent, the extraction time, the type and volume of loading solvent, and the type of eluting solvent on the extraction efficiency were investigated and optimized. Under the optimum operation conditions, the limits of detection for seven triazine herbicides in rice samples obtained by high-performance liquid chromatography were 3.16-5.42 ng/g, which were lower than the maximum residue levels established by various organizations. The linear correlation coefficients were higher than 0.9975 in the concentration range of 0.015-1.08 μg/g for the seven triazine herbicides. The recoveries of the seven triazine herbicides at the two concentration levels of 0.15 and 0.45 μg/g are between 82.47 and 104.21%, with relative standard deviations of 0.69-9.19%. The intra- and inter-day (n = 5) precisions for all triazine herbicides at the spiked level of 0.30 μg/g were 1.72-11.71%. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. High-frequency HYDRO-geophysical observations for an advanced understanding of clayey landSLIDES: the HYDROSLIDE research project

    Science.gov (United States)

    Malet, Jean-Philippe; Supper, Robert; Flores-Orozco, Adrian; Gautier, Stéphanie; Bogaard, Thom

    2017-04-01

    resistivity is difficult to identify. Therefore the extension of the concept of resistivity to Induced Polarization (IP) (both in the time and spectral domains) is proposed in order to better understand the relationships between physical and hydro(geo)logical properties of the slope material. To understand the landslide triggering mechanisms, surface and in-depth deformation have to be monitored. Up to now, most of the landslides monitoring sites are equipped with GNSS receivers and total station benchmarks at the surface or inclinometers at depths, which provide only point (1D) information and/or have limitations at high displacement rates. To solve interpretation ambiguities and to account for spatial changes, not only point information, but also horizontally and vertically (borehole) distributed displacement/strain observations are necessary. New approaches are suggested in the project, namely temperature and strain monitoring at high frequency with Fiber-Optic (FO) cables both at the surface and in boreholes, sensing of surface deformation with Ultra-High Resolution (UHR, 20 cm) optical images (time-lapse ground based cameras). The combined application of these methods for landslide monitoring is very rare and has not been tested rigorously. Further, the joint interpretation of electrical resistivity, soil temperature, hydrological and strain data need to be supported by coupled multi-physical modelling in order to quantitatively establish petrophysical relationships for several slope configurations, material properties and groundwater conditions. The applicability of the approach is discussed for landslide sites representative of different hydrological forcings: La Valette (South French Alps; Alpes-de-Haute-Provence) and Lodève (South Central Massif, Hérault).

  19. Presentation = Speech + Slides

    Directory of Open Access Journals (Sweden)

    Derik Badman

    2008-12-01

    Full Text Available Back in October, Aaron Schmidt posted “HOWTO give a good presentation” to his blog walking paper. His second bullet point of “thoughts” on good presentations is: Please don’t fill your slides with words. Find some relevant and pretty pictures to support what you’re saying. You can use the pictures to remind yourself what you’re going [...

  20. Structure of high-spin states in sup 1 sup 0 sup 0 Pd

    CERN Document Server

    Pérez, G E; Algora, A; Dombrádi, Z; Nyakó, B M; Timar, J; Zolnai, L; Wyss, R; Cederkäll, J; Johnson, A; Kérek, A; Klamra, W; Norlin, L O; Lipoglavsek, M; Fahlander, C; Likar, A; Palacz, M; Atac, A; Nyberg, J; Persson, J; Gizon, A; Gizon, J; Boston, A J; Paul, E S; Grawe, H; Schubart, R; Joss, D T; Juutinen, S; Maekelae, E; Kownacki, J P; De Poli, M; Bednarczyk, P; De Angelis, G; Seweryniak, D; Foltescu, D; Roth, H A; Skeppstedt, Ö; Jerrestam, D; Shizuma, T; Sletten, G; Toermaenen, S

    2001-01-01

    High-spin states of the neutron deficient sup 1 sup 0 sup 0 Pd nucleus have been investigated via the sup 5 sup 0 Cr( sup 5 sup 8 Ni, 4p alpha) and sup 7 sup 0 Zn( sup 3 sup 6 S,6n) heavy-ion induced reactions. For the detection of evaporated particles and gamma rays the NORDBALL array equipped with ancillary detectors and the EUROGAM II detector system were utilized. By the use of in-beam spectroscopic methods 89 transitions belonging to sup 1 sup 0 sup 0 Pd have been observed, 49 of which were identified for the first time. The level scheme has been extended up to E sub x approx 16 MeV excitation energy and I approx 25 Planck constant. The experimental results were compared with the predictions of cranked shell model calculations. Maximal spin alignments were found in the (pi g sub 9 sub / sub 2) sup - sup 4 sub 1 sub 2 sub sup + (nu d sub 5 sub / sub 2 ,g sub 7 sub / sub 2 sup 3 h sub 1 sub 1 sub / sub 2) sub 1 sub 3 sub sup - and (pi g sub 9 sub / sub 2 sup - sup 3 p sub 1 sub / sub 2) sub 1 sub 1 sub sup...

  1. Enhanced Central System of the Traversing Rod for High-Performance Rotor Spinning Machines

    Directory of Open Access Journals (Sweden)

    Valtera Jan

    2017-03-01

    Full Text Available The paper deals with the improvement of central traversing system on rotor spinning machines, where rectilinear motion with variable stroke is used. A new system of traversing rod with implemented set of magnetic-mechanical energy accumulators is described. Mathematical model of this system is analysed in the MSC. Software Adams/View and verified by an experimental measurement on a real-length testing rig. Analysis results prove the enhancement of devised traversing system, where the overall dynamic force is reduced considerably. At the same time, the precision of the traversing movement over the machine length is increased. This enables to increase machine operating speed while satisfying both the maximal tensile strength of the traversing rod and also output bobbin size standards. The usage of the developed mathematical model for determination of the optimal number and distribution of accumulators over the traversing rod of optional parameters is proved. The potential of the devised system for high-performance rotor spinning machines with longer traversing rod is also discussed.

  2. Equation-of-motion coupled cluster method for the description of the high spin excited states

    Energy Technology Data Exchange (ETDEWEB)

    Musiał, Monika, E-mail: musial@ich.us.edu.pl; Lupa, Łukasz; Kucharski, Stanisław A. [Institute of Chemistry, University of Silesia, Szkolna 9, 40-006 Katowice (Poland)

    2016-04-21

    The equation-of-motion (EOM) coupled cluster (CC) approach in the version applicable for the excitation energy (EE) calculations has been formulated for high spin components. The EE-EOM-CC scheme based on the restricted Hartree-Fock reference and standard amplitude equations as used in the Davidson diagonalization procedure yields the singlet states. The triplet and higher spin components require separate amplitude equations. In the case of quintets, the relevant equations are much simpler and easier to solve. Out of 26 diagrammatic terms contributing to the R{sub 1} and R{sub 2} singlet equations in the case of quintets, only R{sub 2} operator survives with 5 diagrammatic terms present. In addition all terms engaging three body elements of the similarity transformed Hamiltonian disappear. This indicates a substantial simplification of the theory. The implemented method has been applied to the pilot study of the excited states of the C{sub 2} molecule and quintet states of C and Si atoms.

  3. Evolution of spin excitations in a gapped antiferromagnet from the quantum to the high-temperature limit

    DEFF Research Database (Denmark)

    Kenzelmann, M.; Cowley, R.A.; Buyers, W.J.L.

    2002-01-01

    We have mapped from the quantum to the classical limit the spin excitation spectrum of the antiferromagnetic spin-1 Heisenberg chain system CsNiCl3 in its paramagnetic phase from T=5 to 200 K. Neutron scattering shows that the excitations are resonant and dispersive up to at least T=70 Ksimilar o...... and the experiment is not consistent with the random phase approximation for coupled quantum chains. At T=200 K, the structure factor and second energy moment of the excitation spectrum are in excellent agreement with the high-temperature series expansion.......We have mapped from the quantum to the classical limit the spin excitation spectrum of the antiferromagnetic spin-1 Heisenberg chain system CsNiCl3 in its paramagnetic phase from T=5 to 200 K. Neutron scattering shows that the excitations are resonant and dispersive up to at least T=70 Ksimilar...... is in agreement with quantum Monte Carlo calculations for the spin-1 chain. xi is also consistent with the single mode approximation, suggesting that the excitations are short-lived single particle excitations. Below T=12 K where three-dimensional spin correlations are important, xi is shorter than predicted...

  4. Observation of isomeric decays and the high spin states in doubly-odd 208Fr

    CERN Document Server

    Kanjilal, D; Goswami, A; Kshetri, R; Raut, R; Saha, S; Bhowmik, R K; Gehlot, J; Muralithar, S; Singh, R P; Jnaneswari, G; Mukherjee, G; Mukherjee, B

    2009-01-01

    Neutron deficient isotopes of Francium (Z=87, N=121-123) as excited nuclei were produced in the fusion-evaporation reaction: 197Au(16O,xn)[213-x]Fr at 100 MeV. The gamma-rays from the residues were observed through the high sensitivity Germanium Clover detector array INGA. The decay of the high spin states and the isomeric states of the doubly-odd 208Fr nuclei, identified from the known sequence of ground state transitions, were observed. The half lives of the 194(2) keV isomeric transition, known from earlier observations, was measured to be 233(18) ns. A second isomeric transition at 383(2) keV and half life of 33(7) ns was also found. The measured half lives were compared with the corresponding single particle estimates, based on a the level scheme obtained from the experiment.

  5. High spin states and isomeric decays in doubly-odd 208Fr

    Science.gov (United States)

    Kanjilal, D.; Bhattacharya, S.; Goswami, A.; Kshetri, R.; Raut, R.; Saha, S.; Bhowmik, R. K.; Gehlot, J.; Muralithar, S.; Singh, R. P.; Jnaneswari, G.; Mukherjee, G.; Mukherjee, B.

    2010-10-01

    Neutron deficient isotopes of francium ( Z=87, N˜121-123) as excited nuclei were produced in the fusion-evaporation reaction: 197Au( 16O, xn) 213 - xFr at 100 MeV. The γ rays from the residues were observed through the high sensitivity Germanium Clover detector array INGA. The decay of the high spin states and the isomeric states of the doubly-odd 208Fr nuclei, identified from the known sequence of ground state transitions, were observed. The half-lives of the E=194(2) keV isomeric transition, known from earlier observations, was measured to be T=233(18) ns. A second isomeric transition at E=383(2) keV and T=33(7) ns was also found. The measured half-lives were compared with the corresponding single particle estimates, based on the level scheme obtained from the experiment.

  6. A Study of Particle Beam Spin Dynamics for High Precision Experiments

    Energy Technology Data Exchange (ETDEWEB)

    Fiedler, Andrew J. [Northern Illinois Univ., DeKalb, IL (United States)

    2017-05-01

    In the search for physics beyond the Standard Model, high precision experiments to measure fundamental properties of particles are an important frontier. One group of such measurements involves magnetic dipole moment (MDM) values as well as searching for an electric dipole moment (EDM), both of which could provide insights about how particles interact with their environment at the quantum level and if there are undiscovered new particles. For these types of high precision experiments, minimizing statistical uncertainties in the measurements plays a critical role. \\\\ \\indent This work leverages computer simulations to quantify the effects of statistical uncertainty for experiments investigating spin dynamics. In it, analysis of beam properties and lattice design effects on the polarization of the beam is performed. As a case study, the beam lines that will provide polarized muon beams to the Fermilab Muon \\emph{g}-2 experiment are analyzed to determine the effects of correlations between the phase space variables and the overall polarization of the muon beam.

  7. Highly Nuclear-Spin-Polarized Deuterium Atoms from the UV Photodissociation of Deuterium Iodide

    Science.gov (United States)

    Sofikitis, Dimitris; Glodic, Pavle; Koumarianou, Greta; Jiang, Hongyan; Bougas, Lykourgos; Samartzis, Peter C.; Andreev, Alexander; Rakitzis, T. Peter

    2017-06-01

    We report a novel highly spin-polarized deuterium (SPD) source, via the photodissociation of deuterium iodide at 270 nm. I (P2 3 /2) photofragments are ionized with m -state selectivity, and their velocity distribution measured via velocity-map slice imaging, from which the D polarization is determined. The process produces ˜100 % electronically polarized D at the time of dissociation, which is then converted to ˜60 % nuclear D polarization after ˜1.6 ns . These production times for SPD allow collision-limited densities of ˜1 018 cm-3 and at production rates of ˜1 021 s-1 which are 1 06 and 1 04 times higher than conventional (Stern-Gerlach separation) methods, respectively. We discuss the production of SPD beams, and combining high-density SPD with laser fusion, to investigate polarized D-T, D -He 3 , and D-D fusion.

  8. High-quality cell block preparation from scraping of conventional cytology slide: a technical report on a modified cytoscrape cell block technique.

    Science.gov (United States)

    Choi, Y I; Jakhongir, M; Choi, S J; Kim, L; Park, I S; Han, J Y; Kim, J M; Chu, Y C

    2016-12-01

    Immunocytochemistry (ICC) on formalin-fixed paraffin embedded cell blocks is an ancillary tool commonly recruited for differential diagnoses of fine needle aspiration cytology (FNAC) samples. However, the quality of conventional cell blocks in terms of adequate cellularity and evenness of distribution of cytologic material is not always satisfactory for ICC. We introduce a modified agarose-based cytoscrape cell block (CCB) technique that can be effectively used for the preparation of cell blocks from scrapings of conventional FNAC slides. A decoverslipped FNAC slide was mounted with a small amount of water. The cytological material was scraped off the slide into a tissue mold by scraping with a cell scraper. The cytoscrape material was pelleted by centrifugation and pre-embedded in ultra-low gelling temperature agarose and then re-embedded in conventional agarose. The final agarose gel disk was processed and embedded in paraffin. The quality of the ICC on the CCB sections was identical to that of the immunohistochemical stains on histological sections. By scrapping and harvesting the entirety of the cytological material off the cytology slide into a compact agarose cell button, we could avoid the risk of losing diagnostic material during the CCB preparation. This modified CCB technique enables concentration and focusing of minute material while maintaining the entire amount of the cytoscrape material on the viewing spot of the CCB sections. We believe this technique can be effectively used to improve the level of confidence in diagnosis of FNAC especially when the FNAC slides are the only sample available.

  9. Myocardial perfusion magnetic resonance imaging using sliding-window conjugate-gradient highly constrained back-projection reconstruction for detection of coronary artery disease.

    Science.gov (United States)

    Ma, Heng; Yang, Jun; Liu, Jing; Ge, Lan; An, Jing; Tang, Qing; Li, Han; Zhang, Yu; Chen, David; Wang, Yong; Liu, Jiabin; Liang, Zhigang; Lin, Kai; Jin, Lixin; Bi, Xiaoming; Li, Kuncheng; Li, Debiao

    2012-04-15

    Myocardial perfusion magnetic resonance imaging (MRI) with sliding-window conjugate-gradient highly constrained back-projection reconstruction (SW-CG-HYPR) allows whole left ventricular coverage, improved temporal and spatial resolution and signal/noise ratio, and reduced cardiac motion-related image artifacts. The accuracy of this technique for detecting coronary artery disease (CAD) has not been determined in a large number of patients. We prospectively evaluated the diagnostic performance of myocardial perfusion MRI with SW-CG-HYPR in patients with suspected CAD. A total of 50 consecutive patients who were scheduled for coronary angiography with suspected CAD underwent myocardial perfusion MRI with SW-CG-HYPR at 3.0 T. The perfusion defects were interpreted qualitatively by 2 blinded observers and were correlated with x-ray angiographic stenoses ≥50%. The prevalence of CAD was 56%. In the per-patient analysis, the sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of SW-CG-HYPR was 96% (95% confidence interval 82% to 100%), 82% (95% confidence interval 60% to 95%), 87% (95% confidence interval 70% to 96%), 95% (95% confidence interval 74% to100%), and 90% (95% confidence interval 82% to 98%), respectively. In the per-vessel analysis, the corresponding values were 98% (95% confidence interval 91% to 100%), 89% (95% confidence interval 80% to 94%), 86% (95% confidence interval 76% to 93%), 99% (95% confidence interval 93% to 100%), and 93% (95% confidence interval 89% to 97%), respectively. In conclusion, myocardial perfusion MRI using SW-CG-HYPR allows whole left ventricular coverage and high resolution and has high diagnostic accuracy in patients with suspected CAD. Copyright © 2012 Elsevier Inc. All rights reserved.

  10. Summary: symmetries and spin

    Energy Technology Data Exchange (ETDEWEB)

    Haxton, W.C. (Institute for Nuclear Theory, Department of Physcis, FM-15, University of Washington, Seattle, Washington 98195 (US))

    1989-05-01

    I discuss a number of the themes of the Symmetries and Spin session of the 8th International Symposium on High Energy Spin Physics: parity non-conservation, CP/T nonconservation, and tests of charge symmetry and charge independence.

  11. Spin dynamics in high-T{sub C} superconducting cuprates; Dynamique de spins dans les oxydes de cuivre supraconducteurs a haute temperature critique

    Energy Technology Data Exchange (ETDEWEB)

    Bourges, Ph

    2003-07-01

    This work is dedicated to the detailed investigations of the magnetic resonance peak in the superconducting state of cuprates. The existence of such a peak could be the signature of a mechanism linked to magnetism that could explain high critical temperature superconductivity. Inelastic neutron scattering is an adequate tool for the understanding of cuprate properties because it reveals magnetic fluctuations whose behaviour and variety depend strongly on temperature and on the level of doping. The last part of this work is dedicated to the study of spin dynamics in YBa{sub 2}Cu{sub 3}O{sub 6+x} system.

  12. An auto-balancer device for high spin-drying frequencies (LoWash Project

    Directory of Open Access Journals (Sweden)

    Clerc Christian

    2015-01-01

    Full Text Available Auto-balancing or active control balancing can be efficient solutions for high speed rotors with changing out-of-balance loads like washing machines in spin-drying mode. In the LoWash EU project, Vibratec is in charge to design, to build and to validate a balancing system for reducing the vibrations at high spin-drying speeds. The system is based on two trolleys rolling in a ring linked to the drum. The trolley shape allows a ring cross section optimization and they are equipped with a mechanism for escaping the disadvantage encountered at low speeds by similar devices. Analytical and multi-body models are first made for understanding the mechanisms, highlighting the driving parameters and drawing the final design of a first prototype which is inserted in a washing machine drum. Different tests are carried out for different initial unbalances and different rotation speeds: the residual unbalance is measured by means of a set of accelerometers mounted on the tub, while the mobile masses behaviour is observed by means of a large aperture swift camera. The test results highlight the auto-balancer high efficiency but also the sensitivity to geometrical defects which should be corrected in the next systems. According the theory, the balancing is efficient when the rotation frequency is significantly greater than the hanging frequencies. The multi-body model relevance is also demonstrated. A washer-dryer prototype including an auto-balancer second prototype and two other innovations, regarding thermal exchange efficiency and drum insulation, will be tested in operating conditions.

  13. High-resolution electron microscopy in spin pumping NiFe/Pt interfaces

    Energy Technology Data Exchange (ETDEWEB)

    Ley Domínguez, D., E-mail: david.ley@cimav.edu.mx; Sáenz-Hernández, R. J.; Faudoa Arzate, A.; Arteaga Duran, A. I.; Ornelas Gutiérrez, C. E.; Solís Canto, O.; Botello-Zubiate, M. E.; Rivera-Gómez, F. J.; Matutes-Aquino, J. A. [Centro de Investigación en Materiales Avanzados, S.C., Miguel de Cervantes 120, Complejo Industrial Chihuahua, Chihuahua 31109 (Mexico); Azevedo, A.; Silva, G. L. da; Rezende, S. M. [Departamento de Física, Universidade Federal de Pernambuco, 50670-901 Recife, PE (Brazil)

    2015-05-07

    In order to understand the effect of the interface on the spin pumping and magnetic proximity effects, high resolution transmission electron microscopy and ferromagnetic resonance (FMR) were used to analyze Py/Pt bilayer and Pt/Py/Pt trilayer systems. The samples were deposited by dc magnetron sputtering at room temperature on Si (001) substrates. The Py layer thickness was fixed at 12 nm in all the samples and the Pt thickness was varied in a range of 0–23 nm. A diffusion zone of approximately 8 nm was found in the Py/Pt interfaces and confirmed by energy dispersive X-ray microanalysis. The FMR measurements show an increase in the linewidth and a shift in the ferromagnetic resonance field, which reach saturation.

  14. Spin-Orbit Torque from a Magnetic Heterostructure of High-Entropy Alloy

    Science.gov (United States)

    Chen, Tian-Yue; Chuang, Tsao-Chi; Huang, Ssu-Yen; Yen, Hung-Wei; Pai, Chi-Feng

    2017-10-01

    High-entropy alloy (HEA) is a family of metallic materials with nearly equal partitions of five or more metals, which might possess mechanical and transport properties that are different from conventional binary or tertiary alloys. In this work, we demonstrate current-induced spin-orbit torque (SOT) magnetization switching in a Ta-Nb-Hf-Zr-Ti HEA-based magnetic heterostructure with perpendicular magnetic anisotropy. The maximum dampinglike SOT efficiency from this particular HEA-based magnetic heterostructure is further determined to be |ζDLHEA | ≈0.033 by hysteresis-loop-shift measurements, while that for the Ta control sample is |ζDLTa | ≈0.04 . Our results indicate that HEA-based magnetic heterostructures can serve as an alternative group of potential candidates for SOT device applications due to the possibility of tuning buffer-layer properties with more than two constituent elements.

  15. Quantitative Temperature Dependence of Longitudinal Spin Seebeck Effect at High Temperatures

    Directory of Open Access Journals (Sweden)

    Ken-ichi Uchida

    2014-11-01

    Full Text Available We report temperature-dependent measurements of longitudinal spin Seebeck effects (LSSEs in Pt/Y_{3}Fe_{5}O_{12} (YIG/Pt systems in a high temperature range from room temperature to above the Curie temperature of YIG. The experimental results show that the magnitude of the LSSE voltage in the Pt/YIG/Pt systems rapidly decreases with increasing the temperature and disappears above the Curie temperature. The critical exponent of the LSSE voltage in the Pt/YIG/Pt systems at the Curie temperature is estimated to be 3, which is much greater than that for the magnetization curve of YIG. This difference highlights the fact that the mechanism of the LSSE cannot be explained in terms of simple static magnetic properties in YIG.

  16. Interpulse phase corrections for unbalanced pseudo-continuous arterial spin labeling at high magnetic field.

    Science.gov (United States)

    Hirschler, Lydiane; Debacker, Clément S; Voiron, Jérôme; Köhler, Sascha; Warnking, Jan M; Barbier, Emmanuel L

    2017-06-06

    To evaluate a prescan-based radiofrequency phase-correction strategy for unbalanced pseudo-continuous arterial spin labeling (pCASL) at 9.4 T in vivo and to test its robustness toward suboptimal shim conditions. Label and control interpulse phases were optimized separately by means of two prescans in rats. The mean perfusion as well as the interhemispherical symmetry were measured for several phase combinations (optimized versus theoretical phases) to evaluate the correction quality. Interpulse phases were also optimized under degraded shim conditions (i.e., up to four times the study shim values) to test the strategy's robustness. For all tested shim conditions, the full arterial spin labeling (ASL) signal could be restored. Without any correction, the relative ASL signal was 1.4 ± 1.7%. It increased to 3.6 ± 1.4% with an optimized label phase and to 5.3 ± 1.2% with optimized label and control phases. Moreover, asymmetry between brain hemispheres, which could be as high as 100% without phase optimization, was dramatically reduced to 1 ± 3% when applying optimized label and control phases. Pseudo-continuous ASL at high magnetic field is very sensitive to shim conditions. Label and control radiofrequency phase optimization based on prescans robustly maximizes the ASL signal obtained with unbalanced pCASL and minimizes the asymmetry between hemispheres. Magn Reson Med, 2017. © 2017 International Society for Magnetic Resonance in Medicine. © 2017 International Society for Magnetic Resonance in Medicine.

  17. Tuning the Spin State in LaCoO3 Thin Films for Enhanced High-Temperature Oxygen Electrocatalysis.

    Science.gov (United States)

    Hong, Wesley T; Gadre, Milind; Lee, Yueh-Lin; Biegalski, Michael D; Christen, Hans M; Morgan, Dane; Shao-Horn, Yang

    2013-08-01

    The slow kinetics of oxygen surface exchange hinders the efficiency of high-temperature oxygen electrocatalytic devices such as solid oxide fuel cells and oxygen separation membranes. Systematic investigations of material properties that link to catalytic activity can aid in the rational design of highly active cathode materials. Here, we explore LaCoO3 thin films as a model system for tuning catalytic activity through strain-induced changes in the Co spin state. We demonstrate that Raman spectroscopy can be used to probe the Co-O bond strength at different temperatures to determine the relative spin occupancies of LaCoO3. We find that strain can be used to reduce the spin transition temperature and promote the occupation of higher spin states that weaken the Co-O bond. The decrease in Co-O bond strength and increased spin moment of the thin films result in significant enhancements of the oxygen surface exchange kinetics by up to 2 orders of magnitude.

  18. Knowing When to Slide :: Efficient Scheduling for Sliding Window Processing

    OpenAIRE

    Salehi, Ali; Riahi, Mehdi; Michel, Sebastian; Aberer, Karl

    2009-01-01

    We consider sliding window query execution scheduling in stream processing engines. Sliding windows are an essential building block to limit the query focus at a particular part of the stream, based either on value count or time ranges. These so called sliding window predicates specify the execution condition for the query. Due to the often massive amount of registered queries, efficient algorithms to check these predicates are essential. While there exists a comprehensive set of work...

  19. Storytelling Slide Shows to Improve Diabetes and High Blood Pressure Knowledge and Self-Efficacy: Three-Year Results among Community Dwelling Older African Americans

    Science.gov (United States)

    Bertera, Elizabeth M.

    2014-01-01

    This study combined the African American tradition of oral storytelling with the Hispanic medium of "Fotonovelas." A staggered pretest posttest control group design was used to evaluate four Storytelling Slide Shows on health that featured community members. A total of 212 participants were recruited for the intervention and 217 for the…

  20. A high performance ceria based interdiffusion barrier layer prepared by spin-coating

    DEFF Research Database (Denmark)

    Plonczak, Pawel; Joost, Mario; Hjelm, Johan

    2011-01-01

    . The decomposition of the polymer precursor used in the spin-coating process was studied. The depositions were performed on anode supported half cells. By controlling the sintering temperature between each spin-coating process, dense and crack-free CGO films with a thickness of approximately 1 μm were obtained...

  1. Orientation and thickness dependence of magnetization at the interfacesof highly spin-polarized manganite thin films

    Energy Technology Data Exchange (ETDEWEB)

    Chopdekar, Rajesh V.; Arenholz, Elke; Suzuki, Y.

    2008-08-18

    We have probed the nature of magnetism at the surface of (001), (110) and (111)-oriented La{sub 0.7}Sr{sub 0.3}MnO{sub 3} thin films. The spin polarization of La{sub 0.7}Sr{sub 0.3}MnO{sub 3} thin films is not intrinsically suppressed at all surfaces and interfaces but is highly sensitive to both the epitaxial strain state as well as the substrate orientation. Through the use of soft x-ray spectroscopy, the magnetic properties of (001), (110) and (111)-oriented La{sub 0.7}Sr{sub 0.3}MnO{sub 3}/SrTiO{sub 3} interfaces have been investigated and compared to bulk magnetometry and resistivity measurements. The magnetization of (110) and (111)-oriented La{sub 0.7}Sr{sub 0.3}MnO{sub 3}/SrTiO{sub 3} interfaces are more bulk-like as a function of thickness whereas the magnetization at the (001)-oriented La{sub 0.7}Sr{sub 0.3}MnO{sub 3}/SrTiO{sub 3} interface is suppressed significantly below a layer thickness of 20 nm. Such findings are correlated with the biaxial strain state of the La{sub 0.7}Sr{sub 0.3}MnO{sub 3} films; for a given film thickness it is the tetragonal distortion of (001) La{sub 0.7}Sr{sub 0.3}MnO{sub 3} that severely impacts the magnetization, whereas the trigonal distortion for (111)-oriented films and monoclinic distortion for (110)-oriented films have less of an impact. These observations provide evidence that surface magnetization and thus spin polarization depends strongly on the crystal surface orientation as well as epitaxial strain.

  2. Highly Stretchable Core-Sheath Fibers via Wet-Spinning for Wearable Strain Sensors.

    Science.gov (United States)

    Tang, Zhenhua; Jia, Shuhai; Wang, Fei; Bian, Changsheng; Chen, Yuyu; Wang, Yonglin; Li, Bo

    2018-02-12

    Lightweight, stretchable, and wearable strain sensors have recently been widely studied for the development of health monitoring systems, human-machine interfaces, and wearable devices. Herein, highly stretchable polymer elastomer-wrapped carbon nanocomposite piezoresistive core-sheath fibers are successfully prepared using a facile and scalable one-step coaxial wet-spinning assembly approach. The carbon nanotube-polymeric composite core of the stretchable fiber is surrounded by an insulating sheath, similar to conventional cables, and shows excellent electrical conductivity with a low percolation threshold (0.74 vol %). The core-sheath elastic fibers are used as wearable strain sensors, exhibiting ultra-high stretchability (above 300%), excellent stability (>10 000 cycles), fast response, low hysteresis, and good washability. Furthermore, the piezoresistive core-sheath fiber possesses bending-insensitiveness and negligible torsion-sensitive properties, and the strain sensing performance of piezoresistive fibers maintains a high degree of stability under harsh conditions. On the basis of this high level of performance, the fiber-shaped strain sensor can accurately detect both subtle and large-scale human movements by embedding it in gloves and garments or by directly attaching it to the skin. The current results indicate that the proposed stretchable strain sensor has many potential applications in health monitoring, human-machine interfaces, soft robotics, and wearable electronics.

  3. Development of neutron resonance spin flipper for high resolution NRSE spectrometer

    Energy Technology Data Exchange (ETDEWEB)

    Kitaguchi, Masaaki [Research Reactor Institute, Kyoto University, Kumatori, Osaka 590-0494 (Japan)]. E-mail: kitaguch@rri.kyoto-u.ac.jp; Hino, Masahiro [Research Reactor Institute, Kyoto University, Kumatori, Osaka 590-0494 (Japan); Kawabata, Yuji [Research Reactor Institute, Kyoto University, Kumatori, Osaka 590-0494 (Japan); Hayashida, Hirotoshi [Faculty of Engineering, Kyoto University, Kyoto 606-8501 (Japan); Tasaki, Seiji [Faculty of Engineering, Kyoto University, Kyoto 606-8501 (Japan); Maruyama, Ryuji [JAEA, Tokai, Ibaraki 319-1195 (Japan); Yamazaki, Dai [JAEA, Tokai, Ibaraki 319-1195 (Japan); Ebisawa, Toru [JAEA, Tokai, Ibaraki 319-1195 (Japan); Torikai, Naoya [KEK, Tsukuba, Ibaraki 305-0801 (Japan)

    2006-11-15

    Neutron spin echo (NSE) is one of the techniques with the highest energy resolution for measurement of quasi-elastic scattering. In neutron resonance spin echo (NRSE), two separated neutron resonance spin flippers (RSFs) replace a homogeneous static magnetic field for spin precession in a conventional NSE. We have made a new type of RSF with pure aluminum wires in order to reduce the scattering from the surface. Test experiments have been performed at cold neutron beam line MINE1 at JRR-3M reactor in JAERI and the beam line CN3 at KUR The spin-flip probability was higher than 0.95 at a neutron wavelength of 0.81 nm and a RSF frequency of 100 kHz.

  4. High-efficiency control of spin-wave propagation in ultra-thin yttrium iron garnet by the spin-orbit torque

    Energy Technology Data Exchange (ETDEWEB)

    Evelt, M.; Demidov, V. E., E-mail: demidov@uni-muenster.de [Institute for Applied Physics and Center for Nanotechnology, University of Muenster, 48149 Muenster (Germany); Bessonov, V. [M.N. Miheev Institute of Metal Physics of Ural Branch of Russian Academy of Sciences, Yekaterinburg 620041 (Russian Federation); Demokritov, S. O. [Institute for Applied Physics and Center for Nanotechnology, University of Muenster, 48149 Muenster (Germany); M.N. Miheev Institute of Metal Physics of Ural Branch of Russian Academy of Sciences, Yekaterinburg 620041 (Russian Federation); Prieto, J. L. [Instituto de Sistemas Optoelectrónicos y Microtecnologa (UPM), Ciudad Universitaria, Madrid 28040 (Spain); Muñoz, M. [IMM-Instituto de Microelectrónica de Madrid (CNM-CSIC), PTM, E-28760 Tres Cantos, Madrid (Spain); Ben Youssef, J. [Laboratoire de Magnétisme de Bretagne CNRS, Université de Bretagne Occidentale, 29285 Brest (France); Naletov, V. V. [Service de Physique de l' État Condensé, CEA, CNRS, Université Paris-Saclay, CEA Saclay, 91191 Gif-sur-Yvette (France); Institute of Physics, Kazan Federal University, Kazan 420008 (Russian Federation); Loubens, G. de [Service de Physique de l' État Condensé, CEA, CNRS, Université Paris-Saclay, CEA Saclay, 91191 Gif-sur-Yvette (France); Klein, O. [INAC-SPINTEC, CEA/CNRS and Univ. Grenoble Alpes, 38000 Grenoble (France); Collet, M.; Garcia-Hernandez, K.; Bortolotti, P.; Cros, V.; Anane, A. [Unité Mixte de Physique CNRS, Thales, Univ. Paris Sud, Université Paris-Saclay, 91767 Palaiseau (France)

    2016-04-25

    We study experimentally with submicrometer spatial resolution the propagation of spin waves in microscopic waveguides based on the nanometer-thick yttrium iron garnet and Pt layers. We demonstrate that by using the spin-orbit torque, the propagation length of the spin waves in such systems can be increased by nearly a factor of 10, which corresponds to the increase in the spin-wave intensity at the output of a 10 μm long transmission line by three orders of magnitude. We also show that, in the regime, where the magnetic damping is completely compensated by the spin-orbit torque, the spin-wave amplification is suppressed by the nonlinear scattering of the coherent spin waves from current-induced excitations.

  5. NEMD simulations for ductile metal sliding

    Energy Technology Data Exchange (ETDEWEB)

    Hammerberg, James E [Los Alamos National Laboratory; Germann, Timothy C [Los Alamos National Laboratory; Ravelo, Ramon J [Los Alamos National Laboratory; Holian, Brad L [Los Alamos National Laboratory

    2011-01-31

    We have studied the sliding behavior for a 19 M Al(110)/Al(110) defective crystal at 15 GPa as a function of relative sliding velocity. The general features are qualitatively similar to smaller scale (1.4 M) atom simulations for Al(111)/Al(110) nondefective single crystal sliding. The critical velocity, v{sub c}, is approximately the same for the defective crystal as the size scaled v{sub c}. The lower velocity tangential force is depressed relative to the perfect crystal. The critical temperature, T*, is depressed relative to the perfect crystal. These conclusions are consistent with a lower value for f{sub c} for the defective crystal. The detailed features of structural transformation and the high velocity regime remain to be mapped.

  6. Quantum Spin Liquids

    OpenAIRE

    Savary, Lucile; Balents, Leon

    2016-01-01

    Quantum spin liquids may be considered "quantum disordered" ground states of spin systems, in which zero point fluctuations are so strong that they prevent conventional magnetic long range order. More interestingly, quantum spin liquids are prototypical examples of ground states with massive many-body entanglement, of a degree sufficient to render these states distinct phases of matter. Their highly entangled nature imbues quantum spin liquids with unique physical aspects, such as non-local e...

  7. High-Frequency and -Field Electron Paramagnetic Resonance of High-Spin Manganese(III) in Porphyrinic Complexes.

    Science.gov (United States)

    Krzystek, J.; Telser, Joshua; Pardi, Luca A.; Goldberg, David P.; Hoffman, Brian M.; Brunel, Louis-Claude

    1999-12-27

    High-field and -frequency electron paramagnetic resonance (HFEPR) spectroscopy has been used to study two complexes of high-spin manganese(III), d(4), S = 2. The complexes studied were (tetraphenylporphyrinato)manganese(III) chloride and (phthalocyanato)manganese(III) chloride. Our previous HFEPR study (Goldberg, D. P.; Telser, J.; Krzystek, J.; Montalban, A. G.; Brunel, L.-C.; Barrett, A. G. M.; Hoffman, B. M. J. Am. Chem. Soc. 1997, 119, 8722-8723) included results on the porphyrin complex; however, we were unable to obtain true powder pattern HFEPR spectra, as the crystallites oriented in the intense external magnetic field. In this work we are now able to immobilize the powder, either in an n-eicosane mull or KBr pellet and obtain true powder pattern spectra. These spectra have been fully analyzed using spectral simulation software, and a complete set of spin Hamiltonian parameters has been determined for each complex. Both complexes are rigorously axial systems, with relatively low magnitude zero-field splitting: D approximately -2.3 cm(-)(1) and g values quite close to 2.00. Prior to this work, no experimental nor theoretical data exist for the metal-based electronic energy levels in Mn(III) complexes of porphyrinic ligands. This lack of information is in contrast to other transition metal complexes and is likely due to the dominance of ligand-based transitions in the absorption spectra of Mn(III) complexes of this type. We have therefore made use of theoretical values for the electronic energy levels of (phthalocyanato)copper(II), which electronically resembles these Mn(III) complexes. This analogy works surprisingly well in terms of the agreement between the calculated and experimentally determined EPR parameters. These results show a significant mixing of the triplet (S = 1) excited state with the quintet (S = 2) ground state in Mn(III) complexes with porphyrinic ligands. This is in agreement with the experimental observation of lower spin ground states in

  8. Use of spin labels to study membrane proteins by high-frequency electron nuclear double resonance spectroscopy

    NARCIS (Netherlands)

    Orlinkskii, S.B.; Borovykh, I.V.; Zielke, V.; Steinhoff, H.J.

    2007-01-01

    The applicability of spin labels to study membrane proteins by high-frequency electron nuclear double resonance spectroscopy is demonstrated. With the use of bacteriorhodopsin embedded in a lipid membrane as an example, the spectra of protons of neighboring amino acids are recorded, electric field

  9. Entrepreneurship and prior experience as antecedents of absorptive capacity of high-tech academic spin-offs

    NARCIS (Netherlands)

    Khodaei, H.; Scholten, V.; Wubben, E.F.M.; Omta, S.W.F.

    2016-01-01

    We investigate the influence of entrepreneurial orientation and team efficacy, in addition to the impact of domain-specific industry and research experience of spin-off management teams, on absorptive capacity, both potential and realised. A multiple regression analysis in 95 Dutch high-tech

  10. Ultrafast high harmonics for probing the fastest spin and charge dynamics in magnetic materials

    Science.gov (United States)

    Grychtol, Patrick

    2015-03-01

    Ultrafast light based on the high-harmonic up-conversion of femtosecond laser pulses have been successfully employed to access resonantly enhanced magnetic contrast at the Mabsorption edges of the 3d ferromagnets Fe, Co and Ni in a table-top setup. Thus, it has been possible to study element-specific dynamics in magnetic materials at femtosecond time scales in a laboratory environment, providing a wealth of opportunities for a greater fundamental understanding of correlated phenomena in solid-state matter. However, these investigations have so far been limited to linear polarized harmonics, since most techniques by which circular soft x-rays can be generated are highly inefficient reducing the photon flux to a level unfit for scientific applications. Besides presenting key findings of our ultrafast studies on charge and spin dynamics, we introduce a simple setup which allows for the efficient generation of circular harmonics bright enough for XMCD experiments. Our work thus represents a critical advance that enables element-specific imaging and spectroscopy of multiple elements simultaneously in magnetic and other chiral media with very high spatial and temporal resolution on the tabletop. In collboration with Ronny Knut, Emrah Turgut, Dmitriy Zusin, Christian Gentry, Henry Kapteyn, Margaret Murnane, JILA, University of Colorado, Boulder; Justin Shaw, Hans Nembach, Tom Silva, Electromagnetics Division, NIST, Boulder, CO; and Ofer Kfir, Avner Fleischer, Oren Cohen, Extreme Nonlinear Optics Group, Solid State Institute, Technion, Israel.

  11. Electron spin resonance spectroscopy of high purity crystals at millikelvin temperatures

    Science.gov (United States)

    Farr, Warrick G.; Creedon, Daniel L.; Goryachev, Maxim; Benmessai, Karim; Tobar, Michael E.

    2013-12-01

    Progress in the emerging field of engineered quantum systems requires the development of devices that can act as quantum memories. The realisation of such devices by doping solid state cavities with paramagnetic ions imposes a trade-off between ion concentration and cavity coherence time. Here, we investigate an alternative approach involving interactions between photons and naturally occurring impurity ions in ultra-pure crystalline microwave cavities exhibiting exceptionally high quality factors. We implement a hybrid Whispering Gallery/Electron Spin Resonance method to perform rigorous spectroscopy of an undoped single-crystal sapphire resonator over the frequency range 8{19 GHz, and at external applied DC magnetic fields up to 0.9 T. Measurements of a high purity sapphire cooled close to 100 mK reveal the presence of Fe3+, Cr3+, and V2+ impurities. A host of electron transitions are measured and identified, including the two-photon classically forbidden quadrupole transition (Δms = 2) for Fe3+, as well as hyperfine transitions of V2+.

  12. Highly spin-polarized deuterium atoms from the UV dissociation of Deuterium Iodide

    CERN Document Server

    Sofikitis, D; Koumarianou, G; Jiang, H; Bougas, L; Samartzis, P C; Andreev, A; Rakitzis, T P

    2016-01-01

    Hyperpolarisation of deuterium (D) and tritium (T) nuclear spins increases the D-T fusion reaction rate by ~50%, thus lowering the breakeven limit for the achievement of self-sustained fusion, and controls the emission direction of the reaction products for improved reactor efficiency. However, the important D-D polarization-dependent fusion reaction has not yet been measured, due to the low density of conventional polarized deuterium beams of ~10$^{12}$ cm$^{-3}$, limited by collisions on the ms-timescale of production. Here we demonstrate that hyperpolarised D atoms are produced by the 270 nm photodissociation of deuterium iodide (DI), yielding ~60% nuclear D polarization after ~1.6 ns, ~10$^6$ times faster than conventional methods, allowing collision-limited densities of ~10$^{18}$ cm$^{-3}$. Such ultrahigh densities of polarized D atoms open the way for the study of high-signal polarized D-D reactions. We discuss the possibility of the production of high-density pulsed polarized beams, and of polarized D...

  13. High dynamic range magnetometry with a single nuclear spin in diamond

    Energy Technology Data Exchange (ETDEWEB)

    Waldherr, Gerald; Beck, Johannes; Neumann, Philipp; Nitsche, Matthias; Wrachtrup, Joerg [3. Physikalisches Institut, Universitaet Stuttgart, 70569 Stuttgart (Germany); Said, Ressa S. [Institut fuer Quanten-Informationsverarbeitung, Universitaet Ulm, 89081 Ulm (Germany); Twamley, Jason [Centre for Engineered Quantum Systems, Faculty of Science, Macquarie University, Sydney (Australia); Jelezko, Fedor [Institut fuer Quantenoptik, Universitaet Ulm, 89073 Ulm (Germany)

    2012-07-01

    Sensors based on the nitrogen-vacancy (NV) defect in diamond are being developed to measure weak magnetic and electric fields at nanoscale. However, such sensors rely on measurements of a shift in the Lamor frequency of the defect, so an accumulation of quantum phase causes the measurement signal to exhibit a periodic modulation. This means that the measurement time is either restricted to half of one oscillation period, which limits accuracy, or that the magnetic field range must be known in advance. Moreover, the precision increases only slowly, as T{sup -0.5}, with the measurement time T. We implement a quantum phase estimation algorithm on a single nuclear spin in diamond to combine both high sensitivity and high dynamic range. By achieving a scaling of the precision with time to T{sup -0.85}, we improve the sensitivity by a factor of 7.4, for an accessible field range of 16 mT, or alternatively, we improve the dynamic range by a factor of 130 for a sensitivity of 2.5 {mu}T/Hz{sup 0.5}. These methods are applicable to a variety of field detection schemes, and do not require entanglement.

  14. High-fidelity spin measurement on the nitrogen-vacancy center

    Science.gov (United States)

    Hanks, Michael; Trupke, Michael; Schmiedmayer, Jörg; Munro, William J.; Nemoto, Kae

    2017-10-01

    Nitrogen-vacancy (NV) centers in diamond are versatile candidates for many quantum information processing tasks, ranging from quantum imaging and sensing through to quantum communication and fault-tolerant quantum computers. Critical to almost every potential application is an efficient mechanism for the high fidelity readout of the state of the electronic and nuclear spins. Typically such readout has been achieved through an optically resonant fluorescence measurement, but the presence of decay through a meta-stable state will limit its efficiency to the order of 99%. While this is good enough for many applications, it is insufficient for large scale quantum networks and fault-tolerant computational tasks. Here we explore an alternative approach based on dipole induced transparency (state-dependent reflection) in an NV center cavity QED system, using the most recent knowledge of the NV center’s parameters to determine its feasibility, including the decay channels through the meta-stable subspace and photon ionization. We find that single-shot measurements above fault-tolerant thresholds should be available in the strong coupling regime for a wide range of cavity-center cooperativities, using a majority voting approach utilizing single photon detection. Furthermore, extremely high fidelity measurements are possible using weak optical pulses.

  15. Analysis of crystallographic slip and grain boundary sliding in a Ti–45Al–2Nb–2Mn (at%)–0.8 vol%TiB{sub 2} alloy by high temperature in situ mechanical testing

    Energy Technology Data Exchange (ETDEWEB)

    Muñoz-Moreno, R. [IMDEA Materials Institute, C/Eric Kandel 2, 28906 Getafe, Madrid (Spain); Department of Materials Science and Engineering, Universidad Carlos III de Madrid, Avda. Universidad 30, 28911 Leganés (Spain); Ruiz-Navas, E.M. [Department of Materials Science and Engineering, Universidad Carlos III de Madrid, Avda. Universidad 30, 28911 Leganés (Spain); Boehlert, C.J. [IMDEA Materials Institute, C/Eric Kandel 2, 28906 Getafe, Madrid (Spain); Department of Chemical Engineering and Materials Science, Michigan State University, 2527 Engineering Building, East Lansing, MI 48824 (United States); Llorca, J. [IMDEA Materials Institute, C/Eric Kandel 2, 28906 Getafe, Madrid (Spain); Department of Materials Science, Polytechnic University of Madrid, 28040 Madrid (Spain); Torralba, J.M. [IMDEA Materials Institute, C/Eric Kandel 2, 28906 Getafe, Madrid (Spain); Department of Materials Science and Engineering, Universidad Carlos III de Madrid, Avda. Universidad 30, 28911 Leganés (Spain); Pérez-Prado, M.T., E-mail: teresa.perez.prado@imdea.org [IMDEA Materials Institute, C/Eric Kandel 2, 28906 Getafe, Madrid (Spain)

    2014-06-01

    This work aims to contribute to a further understanding of the fundamentals of crystallographic slip and grain boundary sliding in the γ-TiAl Ti–45Al–2Nb–2Mn (at%)–0.8 vol%TiB{sub 2} intermetallic alloy, by means of in situ high-temperature tensile testing combined with electron backscatter diffraction (EBSD). Several microstructures, containing different fractions and sizes of lamellar colonies and equiaxed γ-grains, were fabricated by either centrifugal casting or powder metallurgy, followed by heat treatment at 1300 °C and furnace cooling. in situ tensile and tensile-creep experiments were performed in a scanning electron microscope (SEM) at temperatures ranging from 580 °C to 700 °C. EBSD was carried out in selected regions before and after straining. Our results suggest that, during constant strain rate tests, true twin γ/γ interfaces are the weakest barriers to dislocations and, thus, that the relevant length scale might be influenced by the distance between non-true twin boundaries. Under creep conditions both grain/colony boundary sliding (G/CBS) and crystallographic slip are observed to contribute to deformation. The incidence of boundary sliding is particularly high in γ grains of duplex microstructures. The slip activity during creep deformation in different microstructures was evaluated by trace analysis. Special emphasis was placed in distinguishing the compliance of different slip events with the Schmid law with respect to the applied stress.

  16. The spin-half XXZ antiferromagnet on the square lattice revisited: A high-order coupled cluster treatment

    Science.gov (United States)

    Bishop, R. F.; Li, P. H. Y.; Zinke, R.; Darradi, R.; Richter, J.; Farnell, D. J. J.; Schulenburg, J.

    2017-04-01

    We use the coupled cluster method (CCM) to study the ground-state properties and lowest-lying triplet excited state of the spin-half XXZ antiferromagnet on the square lattice. The CCM is applied to it to high orders of approximation by using an efficient computer code that has been written by us and which has been implemented to run on massively parallelized computer platforms. We are able therefore to present precise data for the basic quantities of this model over a wide range of values for the anisotropy parameter Δ in the range - 1 ≤ Δ 1) regimes, where Δ → ∞ represents the Ising limit. We present results for the ground-state energy, the sublattice magnetization, the zero-field transverse magnetic susceptibility, the spin stiffness, and the triplet spin gap. Our results provide a useful yardstick against which other approximate methods and/or experimental studies of relevant antiferromagnetic square-lattice compounds may now compare their own results. We also focus particular attention on the behaviour of these parameters for the easy-axis system in the vicinity of the isotropic Heisenberg point (Δ = 1) , where the model undergoes a phase transition from a gapped state (for Δ > 1) to a gapless state (for Δ ≤ 1), and compare our results there with those from spin-wave theory (SWT). Interestingly, the nature of the criticality at Δ = 1 for the present model with spins of spin quantum number s =1/2 that is revealed by our CCM results seems to differ qualitatively from that predicted by SWT, which becomes exact only for its near-classical large-s counterpart.

  17. High-Frequency Dynamics Modulated by Collective Magnetization Reversal in Artificial Spin Ice

    Energy Technology Data Exchange (ETDEWEB)

    Jungfleisch, Matthias B.; Sklenar, Joseph; Ding, Junjia; Park, Jungsik; Pearson, John E.; Novosad, Valentine; Schiffer, Peter; Hoffmann, Axel

    2017-12-01

    Spin-torque ferromagnetic resonance arises in heavy metal-ferromagnet heterostructures when an alternating charge current is passed through the bilayer stack. The methodology to detect the resonance is based on the anisotropic magnetoresistance, which is the change in the electrical resistance due to different orientations of the magnetization. In connected networks of ferromagnetic nanowires, known as artificial spin ice, the magnetoresistance is rather complex owing to the underlying collective behavior of the geometrically frustrated magnetic domain structure. Here, we demonstrate spin-torque ferromagnetic resonance investigations in a square artificial spin-ice system and correlate our observations to magneto-transport measurements. The experimental findings are described using a simulation approach that highlights the importance of the correlated dynamics response of the magnetic system. Our results open the possibility of designing reconfigurable microwave oscillators and magnetoresistive devices based on connected networks of nanomagnets.

  18. Using Scrap Slides for Art.

    Science.gov (United States)

    Hanlon, Heather

    1979-01-01

    Using scrap slides for an art lesson can be an exciting, creative experience for people of all ages, and many techniques are applicable in both primary and secondary grades. Scrap slides are an inexpensive means to unique, original, and stimulating discoveries about film as an art form. (Author)

  19. FY1995 study of high density near-contact magnetic recording using spin valve head; 1995 nendo spin valve head ni yoru chokomitsudo near contact jiki kiroku no kenkyu

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-03-01

    Development of high performance spin valves formed by amorphous magnetic layer and head-medium interface with nano-thickness molecular film for realizing an ultra-high density of 20 Gbit/in{sup 2} using contact recording. The giant magnetoresistance effect was investigated for spin valves using very thin amorphous magnetic layer. In amorphous-CoFeB/Cu/ Co spin valves, the maximum MR ratio of 6% was achieved at the thickness of the amorphous layer of 2 nm. The spin valves with the amorphous layer exhibit very good thermal stability. Design guideline for molecularly thin lubricant was established using newly derived lubrication equation considering lubricant porosity. Novel method for accurately measuring surface force due to molecularly thin lubricant was developed by using Michelson interferometry to detect cantilever displacement, which enabled two-dimensional transient force measurement. (NEDO)

  20. Optical cooling and trapping highly magnetic atoms: The benefits of a spontaneous spin polarization

    CERN Document Server

    Dreon, Davide; Bouazza, Chayma; Maineult, Wilfried; Dalibard, Jean; Nascimbene, Sylvain

    2016-01-01

    From the study of long-range-interacting systems to the simulation of gauge fields, open-shell Lanthanide atoms with their large magnetic moment and narrow optical transitions open novel directions in the field of ultracold quantum gases. As for other atomic species, the magneto-optical trap (MOT) is the working horse of experiments but its operation is challenging, due to the large electronic spin of the atoms. Here we present an experimental study of narrow-line Dysprosium MOTs. We show that the combination of radiation pressure and gravitational forces leads to a spontaneous polarization of the electronic spin. The spin composition is measured using a Stern-Gerlach separation of spin levels, revealing that the gas becomes almost fully spin-polarized for large laser frequency detunings. In this regime, we reach the optimal operation of the MOT, with samples of typically $3\\times 10^8$ atoms at a temperature of 20$\\,\\mu$K. The spin polarization reduces the complexity of the radiative cooling description, whi...

  1. High power all-metal spin torque oscillator using full Heusler Co{sub 2}(Fe,Mn)Si

    Energy Technology Data Exchange (ETDEWEB)

    Seki, Takeshi, E-mail: go-sai@imr.tohoku.ac.jp; Sakuraba, Yuya; Ueda, Masaki; Okura, Ryo; Takanashi, Koki [Institute for Materials Research, Tohoku University, Sendai 980-8577 (Japan); Arai, Hiroko; Imamura, Hiroshi [Spintronics Research Center, National Institute of Advanced Industrial Science and Technology, Tsukuba 305-8568 (Japan)

    2014-09-01

    We showed the high rf power (P{sub out}) emission from an all-metal spin torque oscillator (STO) with a Co{sub 2}Fe{sub 0.4}Mn{sub 0.6}Si (CFMS)/Ag/CFMS giant magnetoresistance (GMR) stack, which was attributable to the large GMR effect thanks to the highly spin-polarized CFMS. The oscillation spectra were measured by varying the magnetic field direction, and the perpendicular magnetic field was effective to increase P{sub out} and the Q factor. We simultaneously achieved a high output efficiency of 0.013%, a high Q of 1124, and large frequency tunability. CFMS-based all-metal STO is promising for overcoming the difficulties that conventional STOs are confronted with.

  2. Observation of Proton Radioactivity of the (21+) High-Spin Isomerin 94Ag

    Energy Technology Data Exchange (ETDEWEB)

    Mukha, I.; Roeckl, E.; Doring, J.; Batist, L.; Blazhev, A.; Grawe, H.; Hoffman, C.R.; Huyse, M.; Janas, Z.; Kirchner, R.; La Commara,M.; Mazzocchi, C.; Plettner, C.; Tabor, S.L.; Van Duppen, P.; Wiedeking, M.

    2005-07-05

    We have observed direct one-proton decay of the (21{sup +}) isomer in the N=Z nuclide {sup 94}Ag into high-spin states in {sup 93}Pd by detecting protons in coincidence with {gamma}-{gamma} correlations and applying {gamma} gates based on known {sup 93}Pd levels. Two decay branches have been identified, with proton energies of 0.79(3) and 1.01(3) MeV and branching ratios of 1.9(5)% and 2.2(4)%, respectively. The corresponding partial half-life values are 21(6) and 18(4) s. The Q value of the direct proton decay of the (21{sup +}) isomer was found to be 5.78(3) MeV. The very small reduced widths of the observed proton decays might reflect dominating collective configurations in the (21{sup +}) isomer, and the fine structure of the proton spectrum might indicate a strong deformation of this state.

  3. Spin dynamics in high-mobility two-dimensional electron systems embedded in GaAs/AlGaAs quantum wells

    Energy Technology Data Exchange (ETDEWEB)

    Griesbeck, Michael

    2012-11-22

    Since many years there has been great effort to explore the spin dynamics in low-dimensional electron systems embedded in GaAs/AlGaAs based heterostructures for the purpose of quantum computation and spintronics applications. Advances in technology allow for the design of high quality and well-defined two-dimensional electron systems (2DES), which are perfectly suited for the study of the underlying physics that govern the dynamics of the electron spin system. In this work, spin dynamics in high-mobility 2DES is studied by means of the all-optical time-resolved Kerr/Faraday rotation technique. In (001)-grown 2DES, a strong in-plane spin dephasing anisotropy is studied, resulting from the interference of comparable Rashba and Dresselhaus contributions to the spin-orbit field (SOF). The dependence of this anisotropy on parameters like the confinement length of the 2DES, the sample temperature, as well as the electron density is demonstrated. Furthermore, coherent spin dynamics of an ensemble of ballistically moving electrons is studied without and within an applied weak magnetic field perpendicular to the sample plane, which forces the electrons to move on cyclotron orbits. Finally, strongly anisotropic spin dynamics is investigated in symmetric (110)-grown 2DES, using the resonant spin amplification method. Here, extremely long out-of-plane spin dephasing times can be achieved, in consequence of the special symmetry of the Dresselhaus SOF.

  4. T-Slide Linear Actuators

    Science.gov (United States)

    Vranish, John

    2009-01-01

    T-slide linear actuators use gear bearing differential epicyclical transmissions (GBDETs) to directly drive a linear rack, which, in turn, performs the actuation. Conventional systems use a rotary power source in conjunction with a nut and screw to provide linear motion. Non-back-drive properties of GBDETs make the new actuator more direct and simpler. Versions of this approach will serve as a long-stroke, ultra-precision, position actuator for NASA science instruments, and as a rugged, linear actuator for NASA deployment duties. The T slide can operate effectively in the presence of side forces and torques. Versions of the actuator can perform ultra-precision positioning. A basic T-slide actuator is a long-stroke, rack-and-pinion linear actuator that, typically, consists of a T-slide, several idlers, a transmission to drive the slide (powered by an electric motor) and a housing that holds the entire assembly. The actuator is driven by gear action on its top surface, and is guided and constrained by gear-bearing idlers on its other two parallel surfaces. The geometry, implemented with gear-bearing technology, is particularly effective. An electronic motor operating through a GBDET can directly drive the T slide against large loads, as a rack and pinion linear actuator, with no break and no danger of back driving. The actuator drives the slide into position and stops. The slide holes position with power off and no brake, regardless of load. With the T slide configuration, this GBDET has an entire T-gear surface on which to operate. The GB idlers coupling the other two T slide parallel surfaces to their housing counterpart surfaces provide constraints in five degrees-of-freedom and rolling friction in the direction of actuation. Multiple GB idlers provide roller bearing strength sufficient to support efficient, rolling friction movement, even in the presence of large, resisting forces. T-slide actuators can be controlled using the combination of an off

  5. High-Resolution Spin-on-Patterning of Perovskite Thin Films for a Multiplexed Image Sensor Array.

    Science.gov (United States)

    Lee, Woongchan; Lee, Jongha; Yun, Huiwon; Kim, Joonsoo; Park, Jinhong; Choi, Changsoon; Kim, Dong Chan; Seo, Hyunseon; Lee, Hakyong; Yu, Ji Woong; Lee, Won Bo; Kim, Dae-Hyeong

    2017-10-01

    Inorganic-organic hybrid perovskite thin films have attracted significant attention as an alternative to silicon in photon-absorbing devices mainly because of their superb optoelectronic properties. However, high-definition patterning of perovskite thin films, which is important for fabrication of the image sensor array, is hardly accomplished owing to their extreme instability in general photolithographic solvents. Here, a novel patterning process for perovskite thin films is described: the high-resolution spin-on-patterning (SoP) process. This fast and facile process is compatible with a variety of spin-coated perovskite materials and perovskite deposition techniques. The SoP process is successfully applied to develop a high-performance, ultrathin, and deformable perovskite-on-silicon multiplexed image sensor array, paving the road toward next-generation image sensor arrays. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. Spin-sprayed ferrite films with high resistivity and high-frequency magnetic loss for GHz conducted noise suppressors

    Energy Technology Data Exchange (ETDEWEB)

    Subramani, A.K. [Materials and Structures Laboratory, Tokyo Institute of Technology, 4259 Nagatsuta, Midori, Yokohama (Japan)], E-mail: subramani.aa@m.titech.ac.jp; Matsushita, N. [Materials and Structures Laboratory, Tokyo Institute of Technology, 4259 Nagatsuta, Midori, Yokohama (Japan)], E-mail: matsushita@msl.titech.ac.jp; Watanabe, T. [Materials and Structures Laboratory, Tokyo Institute of Technology, 4259 Nagatsuta, Midori, Yokohama (Japan); Tada, M.; Abe, M. [Department of Physical Electronics, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro, Tokyo 152-8552 (Japan); Kondo, K. [NEC Tokin Corporation, 6-7-1 Koriyama, Taihaku-ku, Sendai, Miyagi 982-8510 (Japan); Yoshimura, M. [Materials and Structures Laboratory, Tokyo Institute of Technology, 4259 Nagatsuta, Midori, Yokohama (Japan)

    2008-02-25

    In the present study, crystallized ferrite (an intermediate between Fe{sub 3}O{sub 4} and {gamma}-Fe{sub 2}O{sub 3}) films prepared by spin-spray technique exhibited strong magnetic losses at high frequencies and are applicable as GHz conducted noise suppressors. The reaction (metal ions) and oxidizing (pH buffers and oxidizing agent) solutions were separately sprayed onto the substrates (90 deg. C) mounted on a rotating disc. Two types of films were prepared on the basis of the different oxidizing solutions; CH{sub 3}COONa + NaNO{sub 2} in the case of film-A and CH{sub 3}COONa + (NH{sub 4}){sub 2}CO{sub 3} + NaNO{sub 2} + NaOH for film-B. The as-prepared films were heat-treated under a condition similar to that of the reflow soldering process (265 deg. C). The effects of the preparation conditions and film morphology on the electrical and magnetic properties before and after the heat treatment were studied. The results revealed that film-B had a relatively smaller initial permeability ({mu}') compared to film-A. However, it had a high-imaginary permeability ({mu}''), resonance frequency (f{sub r}) and surface resistivity ({rho}{sub s}) even after heat treatment. Also, the noise suppressing properties of film-B were relatively good, hence ideal for use as conducted noise suppressors.

  7. High-field study of the spin-Peierls system CuGeO{sub 3}

    Energy Technology Data Exchange (ETDEWEB)

    Regnault, L.P. [CEA Centre d`Etudes de Grenoble, 38 (France)

    1997-04-01

    The one-dimensional spin-1/2 Heisenberg antiferromagnetic system coupled to a three-dimensional phonon field undergoes a structural distortion below a finite temperature T{sub sp} (spin-Peierls transition) which induces the formation of a non-magnetic singlet ground-state and the opening of a gap in the excitation spectrum at the antiferromagnetic point. The recent discovery of the germanate CuGeO{sub 3} as a spin-Peierls system has considerably renewed the interest is this fascinating phenomenon. Inelastic neutron scattering and neutron diffraction have brought very quantitative pieces of information which can be directly compared to the predictions of the standard model. (author). 6 refs.

  8. Spin spring behavior in exchange coupled soft and high-coercivity hard ferromagnets.

    Energy Technology Data Exchange (ETDEWEB)

    Shull, R. D.; Shapiro, A. J.; Gornakov, V. S.; Nikitenko, V. I.; Jiang, J. S.; Kaper, H.; Leaf, G.; Bader, S. D.

    2000-11-01

    The magnetization reversal processes in an epitaxial Fe/Sm{sub 2}Co{sub 7} structure were investigated using the magneto-optical indicator film technique. The dependence of the magnitude and the orientation of the structure average magnetization have been studied on both cycling and rotating the external magnetic field. It was discovered that the magnetization reversal of the soft ferromagnet can proceed by formation of not only one-dimensional, but also two-dimensional, exchange spin springs. Experimental data is compared with a theoretical estimation of the rotational hysteresis loop for a spin system containing a one-dimensional exchange spring.

  9. Absence of high-temperature ballistic transport in the spin-1/2 XXX chain within the grand-canonical ensemble

    Science.gov (United States)

    Carmelo, J. M. P.; Prosen, T.

    2017-01-01

    Whether in the thermodynamic limit, vanishing magnetic field h → 0, and nonzero temperature the spin stiffness of the spin-1/2 XXX Heisenberg chain is finite or vanishes within the grand-canonical ensemble remains an unsolved and controversial issue, as different approaches yield contradictory results. Here we provide an upper bound on the stiffness and show that within that ensemble it vanishes for h → 0 in the thermodynamic limit of chain length L → ∞, at high temperatures T → ∞. Our approach uses a representation in terms of the L physical spins 1/2. For all configurations that generate the exact spin-S energy and momentum eigenstates such a configuration involves a number 2S of unpaired spins 1/2 in multiplet configurations and L - 2 S spins 1/2 that are paired within Msp = L / 2 - S spin-singlet pairs. The Bethe-ansatz strings of length n = 1 and n > 1 describe a single unbound spin-singlet pair and a configuration within which n pairs are bound, respectively. In the case of n > 1 pairs this holds both for ideal and deformed strings associated with n complex rapidities with the same real part. The use of such a spin 1/2 representation provides useful physical information on the problem under investigation in contrast to often less controllable numerical studies. Our results provide strong evidence for the absence of ballistic transport in the spin-1/2 XXX Heisenberg chain in the thermodynamic limit, for high temperatures T → ∞, vanishing magnetic field h → 0 and within the grand-canonical ensemble.

  10. Method for estimating spin-spin interactions from magnetization curves

    Science.gov (United States)

    Tamura, Ryo; Hukushima, Koji

    2017-02-01

    We develop a method to estimate the spin-spin interactions in the Hamiltonian from the observed magnetization curve by machine learning based on Bayesian inference. In our method, plausible spin-spin interactions are determined by maximizing the posterior distribution, which is the conditional probability of the spin-spin interactions in the Hamiltonian for a given magnetization curve with observation noise. The conditional probability is obtained with the Markov chain Monte Carlo simulations combined with an exchange Monte Carlo method. The efficiency of our method is tested using synthetic magnetization curve data, and the results show that spin-spin interactions are estimated with a high accuracy. In particular, the relevant terms of the spin-spin interactions are successfully selected from the redundant interaction candidates by the l1 regularization in the prior distribution.

  11. High accuracy of arterial spin labeling perfusion imaging in differentiation of pilomyxoid from pilocytic astrocytoma

    Energy Technology Data Exchange (ETDEWEB)

    Nabavizadeh, S.A.; Assadsangabi, R.; Hajmomenian, M.; Vossough, A. [Perelman School of Medicine of the University of Pennsylvania, Department of Radiology, Children' s Hospital of Philadelphia, Philadelphia, PA (United States); Santi, M. [Perelman School of Medicine of the University of Pennsylvania, Department of Pathology, Children' s Hospital of Philadelphia, Philadelphia, PA (United States)

    2015-05-01

    Pilomyxoid astrocytoma (PMA) is a relatively new tumor entity which has been added to the 2007 WHO Classification of tumors of the central nervous system. The goal of this study is to utilize arterial spin labeling (ASL) perfusion imaging to differentiate PMA from pilocytic astrocytoma (PA). Pulsed ASL and conventional MRI sequences of patients with PMA and PA in the past 5 years were retrospectively evaluated. Patients with history of radiation or treatment with anti-angiogenic drugs were excluded. A total of 24 patients (9 PMA, 15 PA) were included. There were statistically significant differences between PMA and PA in mean tumor/gray matter (GM) cerebral blood flow (CBF) ratios (1.3 vs 0.4, p < 0.001) and maximum tumor/GM CBF ratio (2.3 vs 1, p < 0.001). Area under the receiver operating characteristic (ROC) curves for differentiation of PMA from PA was 0.91 using mean tumor CBF, 0.95 using mean tumor/GM CBF ratios, and 0.89 using maximum tumor/GM CBF. Using a threshold value of 0.91, the mean tumor/GM CBF ratio was able to diagnose PMA with 77 % sensitivity, 100 % specificity, and a threshold value of 0.7, provided 88 % sensitivity and 86 % specificity. There was no statistically significant difference between the two tumors in enhancement pattern (p = 0.33), internal architecture (p = 0.15), or apparent diffusion coefficient (ADC) values (p = 0.07). ASL imaging has high accuracy in differentiating PMA from PA. The result of this study may have important applications in prognostication and treatment planning especially in patients with less accessible tumors such as hypothalamic-chiasmatic gliomas. (orig.)

  12. Lodalen slide: a probabilistic assessment

    National Research Council Canada - National Science Library

    El-Ramly, H; Morgenstern, N R; Cruden, D M

    2006-01-01

    .... A probabilistic slope analysis methodology based on Monte Carlo simulation using Microsoft® Excel and @Risk software is applied to investigate the Lodalen slide that occurred in Norway in 1954...

  13. Spin current

    CERN Document Server

    Valenzuela, Sergio O; Saitoh, Eiji; Kimura, Takashi

    2012-01-01

    In a new branch of physics and technology called spin-electronics or spintronics, the flow of electrical charge (usual current) as well as the flow of electron spin, the so-called 'spin current', are manipulated and controlled together. This book provides an introduction and guide to the new physics and application of spin current.

  14. IN15 ultra-high-resolution spin-echo project. First experiment

    Energy Technology Data Exchange (ETDEWEB)

    Schleger, P.; Hayes, C. [Institut Max von Laue - Paul Langevin (ILL), 38 - Grenoble (France); Kollmar, A. [Forschungszentrum Juelich GmbH (Germany)

    1997-04-01

    The IN15 project is a collaboration between the ILL, HMI (Berlin), and FZ (Juelich) to construct a spin-echo spectrometer with a fourier time-range surpassing half a microsecond. Three different operational modes are possible: normal, with neutron focusing, and time-of-flight. Present status of the project is described. (author). 3 refs.

  15. Structure of high spin states of 76Kr and 78Kr nuclei

    Indian Academy of Sciences (India)

    Following a fully self-consistent cranked Hartree-Fock-Bogoliubov (CHFB) approach with a pairing+quadrupole+hexadecapole model interaction Hamiltonian the structure of the yrast states of 76,78Kr nuclei is studied up to angular momentum = 24. Evolution of the shape with spin, and rotation alignment of proton as well ...

  16. Probing spin-polarized tunneling at high bias and temperature with a magnetic tunnel transistor

    NARCIS (Netherlands)

    Park, B.G.; Banerjee, T.; Min, B.C.; Sanderink, Johannes G.M.; Lodder, J.C.; Jansen, R.

    2005-01-01

    The magnetic tunnel transistor (MTT) is a three terminal hybrid device that consists of a tunnel emitter, a ferromagnetic (FM) base, and a semiconductor collector. In the MTT with a FM emitter and a single FM base, spin-polarized hot electrons are injected into the base by tunneling. After

  17. Design and Implementation of a Magnetic Levitation System Controller using Global Sliding Mode Control

    Directory of Open Access Journals (Sweden)

    Rudi Uswarman

    2014-07-01

    Full Text Available This paper presents global sliding mode control and conventional sliding mode control for stabilization position of a levitation object. Sliding mode control will be robusting when in sliding mode condition. However, it is not necessarily robust at attaining phase. In the global sliding mode control, the attaining motion phase was eliminated, so that the robustness of the controller can be improved. However, the value of the parameter uncertainties needs to be limited. Besides that, the common problem in sliding mode control is high chattering phenomenon. If the chattering is too large, it can make the system unstable due the limited ability of electronics component. The strategy to overcome the chattering phenomenon is needed. Based on simulation and experimental results, the global sliding mode control has better performance than conventional sliding mode control.  

  18. Estimating the spin diffusion length and the spin Hall angle from spin pumping induced inverse spin Hall voltages

    Science.gov (United States)

    Roy, Kuntal

    2017-11-01

    There exists considerable confusion in estimating the spin diffusion length of materials with high spin-orbit coupling from spin pumping experiments. For designing functional devices, it is important to determine the spin diffusion length with sufficient accuracy from experimental results. An inaccurate estimation of spin diffusion length also affects the estimation of other parameters (e.g., spin mixing conductance, spin Hall angle) concomitantly. The spin diffusion length for platinum (Pt) has been reported in the literature in a wide range of 0.5-14 nm, and in particular it is a constant value independent of Pt's thickness. Here, the key reasonings behind such a wide range of reported values of spin diffusion length have been identified comprehensively. In particular, it is shown here that a thickness-dependent conductivity and spin diffusion length is necessary to simultaneously match the experimental results of effective spin mixing conductance and inverse spin Hall voltage due to spin pumping. Such a thickness-dependent spin diffusion length is tantamount to the Elliott-Yafet spin relaxation mechanism, which bodes well for transitional metals. This conclusion is not altered even when there is significant interfacial spin memory loss. Furthermore, the variations in the estimated parameters are also studied, which is important for technological applications.

  19. Sliding Window Empirical Mode Decomposition -its performance and quality

    Directory of Open Access Journals (Sweden)

    Stepien Pawel

    2014-12-01

    Proposed algorithm speeds up (about 10 times the computation with acceptable quality of decomposition. Conclusions Sliding Window EMD algorithm is suitable for decomposition of long signals with high sampling frequency.

  20. CMOS patterning over high-aspect ratio topographies for N10/N7 using spin-on carbon hardmasks

    Science.gov (United States)

    Hopf, Toby; Ercken, Monique; Mannaert, Geert; Kunnen, Eddy; Tao, Zheng; Vandenbroeck, Nadia; Sebaai, Farid; Kikuchi, Yoshiaki; Mertens, Hans; Kubicek, Stefan; Demuynck, Steven; Horiguchi, Naoto

    2017-03-01

    In this paper proof-of-principle demonstrations of spin-on carbon (SOC)/spin-on glass (SOG)-based lithography processes which could replace standard patterning stacks within the FEOL for upcoming advanced nodes like N10/N7 are presented. At these dimensions the standard lithography approaches that have been utilized within the previous nodes will begin to run into fundamental limitations as a result of the extremely high aspect ratios of the device topography, requiring both new materials as well as new patterning flows in order to allow for continued device scaling. Here, novel SOC/SOG-based patterning flows have been demonstrated which could be applied to implement Source Drain Extension implantations and epitaxial growth processes for CMOS FinFET device architectures even down at N10/N7 dimensions.

  1. High-resolution resonant inelastic extreme ultraviolet scattering from orbital and spin excitations in a Heisenberg antiferromagnet

    Science.gov (United States)

    Caretta, Antonio; Dell'Angela, Martina; Chuang, Yi-De; Kalashnikova, Alexandra M.; Pisarev, Roman V.; Bossini, Davide; Hieke, Florian; Wurth, Wilfried; Casarin, Barbara; Ciprian, Roberta; Parmigiani, Fulvio; Wexler, Surge; Wray, L. Andrew; Malvestuto, Marco

    2017-11-01

    We report a high-resolution resonant inelastic extreme ultraviolet (EUV) scattering study of the quantum Heisenberg antiferromagnet KCoF3. By tuning the EUV photon energy to the cobalt M23 edge, a complete set of low-energy 3 d spin-orbital excitations is revealed. These low-lying electronic excitations are modeled using an extended multiplet-based mean-field calculation to identify the roles of lattice and magnetic degrees of freedom in modifying the resonant inelastic x-ray scattering (RIXS) spectral line shape. We have demonstrated that the temperature dependence of RIXS features upon the antiferromagnetic ordering transition enables us to probe the energetics of short-range spin correlations in this material.

  2. High-spin Mn-oxo complexes and their relevance to the oxygen-evolving complex within photosystem II.

    Science.gov (United States)

    Gupta, Rupal; Taguchi, Taketo; Lassalle-Kaiser, Benedikt; Bominaar, Emile L; Yano, Junko; Hendrich, Michael P; Borovik, A S

    2015-04-28

    The structural and electronic properties of a series of manganese complexes with terminal oxido ligands are described. The complexes span three different oxidation states at the manganese center (III-V), have similar molecular structures, and contain intramolecular hydrogen-bonding networks surrounding the Mn-oxo unit. Structural studies using X-ray absorption methods indicated that each complex is mononuclear and that oxidation occurs at the manganese centers, which is also supported by electron paramagnetic resonance (EPR) studies. This gives a high-spin Mn(V)-oxo complex and not a Mn(IV)-oxy radical as the most oxidized species. In addition, the EPR findings demonstrated that the Fermi contact term could experimentally substantiate the oxidation states at the manganese centers and the covalency in the metal-ligand bonding. Oxygen-17-labeled samples were used to determine spin density within the Mn-oxo unit, with the greatest delocalization occurring within the Mn(V)-oxo species (0.45 spins on the oxido ligand). The experimental results coupled with density functional theory studies show a large amount of covalency within the Mn-oxo bonds. Finally, these results are examined within the context of possible mechanisms associated with photosynthetic water oxidation; specifically, the possible identity of the proposed high valent Mn-oxo species that is postulated to form during turnover is discussed.

  3. High-spin Mn–oxo complexes and their relevance to the oxygen-evolving complex within photosystem II

    Science.gov (United States)

    Gupta, Rupal; Taguchi, Taketo; Lassalle-Kaiser, Benedikt; Bominaar, Emile L.; Yano, Junko; Hendrich, Michael P.; Borovik, A. S.

    2015-01-01

    The structural and electronic properties of a series of manganese complexes with terminal oxido ligands are described. The complexes span three different oxidation states at the manganese center (III–V), have similar molecular structures, and contain intramolecular hydrogen-bonding networks surrounding the Mn–oxo unit. Structural studies using X-ray absorption methods indicated that each complex is mononuclear and that oxidation occurs at the manganese centers, which is also supported by electron paramagnetic resonance (EPR) studies. This gives a high-spin MnV–oxo complex and not a MnIV–oxy radical as the most oxidized species. In addition, the EPR findings demonstrated that the Fermi contact term could experimentally substantiate the oxidation states at the manganese centers and the covalency in the metal–ligand bonding. Oxygen-17–labeled samples were used to determine spin density within the Mn–oxo unit, with the greatest delocalization occurring within the MnV–oxo species (0.45 spins on the oxido ligand). The experimental results coupled with density functional theory studies show a large amount of covalency within the Mn–oxo bonds. Finally, these results are examined within the context of possible mechanisms associated with photosynthetic water oxidation; specifically, the possible identity of the proposed high valent Mn–oxo species that is postulated to form during turnover is discussed. PMID:25852147

  4. Production cross sections for Lee-Wick massive electromagnetic bosons and for spin-zero and spin-one W bosons at high energies.

    Science.gov (United States)

    Linsker, R.

    1972-01-01

    Production cross sections for three types of hypothetical particles are calculated in the presented paper. Several (Z, Z') cases were studied corresponding to elastic scattering off protons and neutrons (either free or embedded within a Fermi sea), coherent scattering off a nucleus, and inelastic scattering off a proton (in which case Z' denotes a nucleon resonance or hadronic system in the continuum). Detailed structure-function data are used to improve the accuracy of the inelastic scattering calculation. Results of calculations are given for beam energies between 50 and 10,000 GeV, and masses between 5 and 40 GeV for the massive Lee-Wick spin-1 boson. Cross sections were computed for resonant and semiweak processes. The production cross section of spin-zero weak intermediate bosons was found to be at least one order of magnitude smaller than for spin-1 weak bosons in nearly all regions of interest. The production cross section of spin-zero weak intermediate bosons for inelastic scattering off protons compares with that for elastic scattering in the regions of interest. In the case of massive spin-1 bosons and spin-1 weak intermediates, the main contribution to total production cross section off protons is elastic.

  5. High spin exotic states and new method for pairing energy; Etats exotiques a hauts spins et nouvelle methode pour l`energie d`appariement nucleaire

    Energy Technology Data Exchange (ETDEWEB)

    Molique, H.

    1996-01-19

    We present a new method called `PSY-MB`, initially developed in the framework of abstract group theory for the solution of the problem of strongly interacting multi-fermionic systems with particular to systems in an external rotating field. The validity of the new method (PSY-MB) is tested on model Hamiltonians. A detailed comparison between the obtained solutions and the exact ones is performed. The new method is used in the study of realistic nuclear Hamiltonians based on the Woods-Saxon potential within the cranking approximation to study the influence of residual monopole pairing interactions in the rare-earth mass region. In parallel with this new technique we present original results obtained with the Woods-Saxon mean-field and the self-consistent Hartree-Fock approximation in order to investigate such exotic effects as octupole deformations and hexadecapole C{sub 4}-polarizing deformations in the framework of high-spin physics. By developing these three approaches in one single work we prepare the ground for the nuclear structure calculations of the new generation - where the residual two-body interactions are taken into account also in the weak pairing limit. (author). 2370refs.

  6. High-spin {gamma}-ray spectroscopy of {sup 124}Ba, {sup 124}Xe and {sup 125}Xe

    Energy Technology Data Exchange (ETDEWEB)

    Al-Khatib, Ali

    2008-08-18

    Rotational spectra had been observed for the first time in excited atomic nuclei in 1938. This observation was attributed to the deviation from spherical shape. In quantum mechanics, when a perfectly spherical system rotates, it appears identical when it is viewed from any direction and no point of reference exists to which the change in position can be identified. Therefore, rotation cannot be defined for spherical nuclei. If the shape deviates from spherical symmetry, the nucleus can rotate and rotational spectra are observed. Many nucleons contribute to the rotation which is referred to as collective excitation. Depending on the mass region, nuclei have different deformations and, therefore, different shapes. Many nuclei show larger deformation with increasing excitation energy. Transitional nuclei between spherical and strongly deformed regions of the nuclear chart are usually soft with respect to deformation changes. In the mass region around A{proportional_to}125, which is the subject of this thesis, nuclei are predicted to be soft with respect to deformation. Rotational motion leads to Coriolis-induced alignments of high-j nucleons, which are in this mass region predominantly protons and neutrons from the h{sub 11/2} unique-parity intruder subshells. The proton Fermi level lies in the lower part of the h{sub 11/2} subshell which favours prolate shape whereas the neutron Fermi level lies in the upper part of the h{sub 11/2} subshell which favours oblate shape. According to the opposite shape-driving forces of protons and neutrons, shape co-existence is expected and the interplay between the h{sub 11/2} proton and neutron orbitals is of great interest for spectroscopic investigations. In addition, superdeformation has been established in this mass region. An interesting observation in this mass region is that nuclei undergo a shape-change from collective prolate to non-collective oblate states at high spins. In this spin range the transitions within the

  7. Active magnetic bearing system based on sliding mode control

    Science.gov (United States)

    Zhang, Yanhong

    2017-07-01

    A new sliding mode variable structure control algorithm suitable for active magnetic bearing is proposed, which is widely used for nonlinear control system. The model and controller is designed, simulation and experimental parts are also made, according to the switching function and the sliding mode control law. The current of electromagnet is adjusted to realize stable levitation of the rotor. The experimental result shows that the sliding mode variable structure controller is an effective way for magnetic bearing control, and the active magnetic bearing system is a highly nonlinear and advanced control method that can reduce the setting time and the cost.

  8. Application of fuzzy sliding-mode control in robot

    Science.gov (United States)

    Fu, Yongling; Wang, Yan

    2006-11-01

    The system of Pb-211 robot waist is a nonlinear hydraulic servo control system. It is very difficult to achieve speedy response without overshoot by the PID control algorithm for the system control. To improve the performance of the system, a new controller is designed with a fuzzy sliding-mode control algorithm, which makes use of the merits both the fuzzy control and the sliding-mode control algorithm. The simulation results show that the new controller is effective, which can achieve high speediness and steady accuracy without overshoot. The fuzzy sliding-mode control has obvious advantage compared the traditional PID algorithm, and it has strong robust too.

  9. Geomorphology, stability and mobility of the Currituck slide

    Science.gov (United States)

    Locat, J.; Lee, H.; ten Brink, Uri S.; Twichell, D.; Geist, E.; Sansoucy, M.

    2009-01-01

    Over the last 100,000??years, the U.S. Atlantic continental margin has experienced various types of mass movements some of which are believed to have taken place at times of low sea level. At one of these times of low sea level a significant trigger caused a major submarine mass movement off the coast of Virginia: the Currituck slide which is believed to have taken place between 24 and 50??ka ago. This slide removed a total volume of about 165??km3 from this section of the continental slope. The departure zone still shows a very clean surface that dips at 4?? and is only covered by a thin veneer of postglacial sediment. Multibeam bathymetric and seismic survey data suggest that this slide took place along three failures surfaces. The morphology of the source area suggests that the sediments were already at least normally consolidated at the time of failure. The slide debris covers an area as much as 55??km wide that extends 180??km from the estimated toe of the original slope. The back analysis of slide initiation indicates that very high pore pressure, a strong earthquake, or both had to be generated to trigger slides on such a low failure plane angle. The shape of the failure plane, the fact that the surface is almost clear of any debris, and the mobility analysis, all support the argument that the slides took place nearly simultaneously. Potential causes for the generation of high pore pressures could be seepage forces from coastal aquifers, delta construction and related pore pressure generation due to the local sediment loading, gas hydrates, and earthquakes. This slide, and its origin, is a spectacular example of the potential threat that submarine mass movements can pose to the US Atlantic coast and underline the need to further assess the potential for the generation of such large slides, like the Grand Banks 1927 landslide of similar volume. ?? 2008 Elsevier B.V.

  10. Photon Self-Induced Spin to Orbital Conversion in TGG crystal at high laser power

    CERN Document Server

    Mosca, S; Karimi, E; Piccirillo, B; Marrucci, L; De Rosa, R; Genin, E; Milano, L; Santamato, E

    2010-01-01

    In this paper, we present experimental evidence of a newly discovered third-order nonlinear optical process Self-Induced Spin-to-Orbital Conversion (SISTOC) of the photon angular momentum. This effect is the physical mechanism at the origin of the depolarization of very intense laser beams propagating in isotropic materials. The SISTOC process, like self-focusing, is triggered by laser heating leading to a radial temperature gradient in the medium. In this work we tested the occurrence of SISTOC in a terbium gallium garnet (TGG) rod for an impinging laser power of about 100~W. To study the SISTOC process we used different techniques: polarization analysis, interferometry and tomography of the photon orbital angular momentum. Our results confirm, in particular, that the apparent depolarization of the beam is due to the occurrence of maximal entanglement between the spin and orbital angular momentum of the photons undergoing the SISTOC process. This explanation of the true nature of the depolarization mechanism...

  11. Spinning Them Off: Entrepreneuring practices in Corporate Spin-Offs

    National Research Council Canada - National Science Library

    Hydle, Katja Maria; Meland, Kjersti Vikse; Haus-Reve, Silje

    2016-01-01

    .... We uncover the enacted aspects of knowledge, called knowing, through theories from seven cases of incumbent-backed spin-offs and find that the management of the parent firms are highly involved in the spin-offs...

  12. Point contact Andreev reflection and the measurement of spin polarization: high fields and novel materials (Conference Presentation)

    Science.gov (United States)

    Stamenov, Plamen; Borisov, Kiril

    2016-10-01

    Point Contact Andreev Reflection (PCAR) is one of the few available methods for the determination of the Fermi level spin polarisation in metals and degenerate semiconductors. It has traditionally been applied at fixed (liquid He) temperatures, using pure niobium as the superconductor, and at essentially zero applied magnetic fields, all of which limit the amount of information that it can provide - i.e. do not allow for the extraction of the sign of the spin polarisation and make the assignment of the transport regime to ballistic or diffusive almost impossible. Here a series of experiments is described, aimed at the expansion of this parameter space to higher magnetic fields and to higher temperatures. These require redesigned experimental setups and the use of higher performance superconductors. Demonstrations are described of the determination of the sign of the spin polarisation, at fields of more than 5 Tesla using a low-Z superconductor, as well as operations beyond 9.2 K. Doubts about the practical reliability of the PCAR technique are dispersed using systematic series of samples - the heavy rare-earths and comparisons with alternatives, such as spin-polarised field emission, photo-emission and Tedrow-Meservey tunnelling. The specific material examples presented include 3d-metals, order-disorder transition alloys and zero-moment half-metals - Fe, FeAl and MnRuGa, alternative low-Z and high-Z superconductors - MgB2 and NbTi, and magnetic topological insulators, such as Cr- and V-doped (Bi1-xSbx)2Te3.

  13. Probing the Impact of Solvation on Photoexcited Spin Crossover Complexes with High-Precision X-ray Transient Absorption Spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Cunming; Zhang, Jianxin [State; Lawson Daku, Latévi M. [Département; Gosztola, David; Canton, Sophie E. [ELI-ALPS, ELI-HU Non-Profit Ltd., Dugonics ter 13, Szeged 6720, Hungary; Attosecond; Zhang, Xiaoyi

    2017-11-17

    Investigating the photoinduced electronic and structural response of bistable molecular building blocks incorporating transition metals in solution phase constitutes a necessary stepping stone for steering their properties towards applications and perfomance optimizations. This work presents a detailed X-ray transient absorption (XTA) spectroscopy study of a prototypical spin crossover (SCO) complex [FeII(mbpy)3]2+ (where mbpy=4,4’-dimethyl-2,2’-bipyridine) with a [FeIIN6] first coordination shell in water (H2O) and acetonitrile (CH3CN). The unprecedented data quality of the XTA spectra together with the direct fitting of the difference spectra in k space using a large number of scattering paths enables resolving the subtle difference in the photoexcited structures of an FeII complex in two solvents for the first time. Compared to the low spin (LS) 1A1 state, the average Fe-N bond elongations for the photoinduced high spin (HS) 5T2 state are found to be 0.181 . 0.003 Å in H2O and 0.199 . 0.003 Å in CH3CN. This difference in structural response is attributed to ligand-solvent interactions that are stronger in H2O than in CH3CN for the HS excited state. Our studies demonstrate that, although the metal center of [FeII(mbpy)3]2+ could have been expected to be rather shielded by the three bidentate ligands with quasi-octahedral-coordination, the ligand field strength in the HS excited state is nevertheless indirectly affected by solvation that modifies the charge distribution within the Fe-N covalent bonds. More generally, this work highlights the importance of including solvation effects in order to develop a generalized understanding of the spin-state switching at the atomic level.

  14. Fabrication of highly spin-polarized Co2FeAl0.5Si0.5 thin-films

    Directory of Open Access Journals (Sweden)

    M. Vahidi

    2014-04-01

    Full Text Available Ferromagnetic Heusler Co2FeAl0.5Si0.5 epitaxial thin-films have been fabricated in the L21 structure with saturation magnetizations over 1200 emu/cm3. Andreev reflection measurements show that the spin polarization is as high as 80% in samples sputtered on unheated MgO (100 substrates and annealed at high temperatures. However, the spin polarization is considerably smaller in samples deposited on heated substrates.

  15. High-order standing spin wave modes in Fe{sub 19}Ni{sub 81} micron wire observed by homodyne method

    Energy Technology Data Exchange (ETDEWEB)

    Yamaguchi, A; Motoi, K; Miyajima, H [Department of Physics, Keio University, Hiyoshi, Yokohama 223-8522 (Japan); Uchiyama, T [Department of Electrical Engineering and Computer, Nagoya University, Chikusaku, Nagoya 464-8603 (Japan); Utsumi, Y, E-mail: yamaguch@phys.keio.ac.jp [Laboratory of Advanced Science and Technology fro Industry, University of Hyogo, Koto, Ako, Hyogo 678-1205 (Japan)

    2011-01-01

    The broadband spin dynamics of patterned ferromagnetic Fe{sub 19}Ni{sub 81} microwire with thickness of 80 nm has been investigated experimentally using broadband rectifying method. The rectifying effect provides a highly sensitive method to detect the high-order perpendicular standing spin wave (PSSW) mode. Present analytical calculation reproduces the observed relation between resonance frequency and applied magnetic field. The effective thickness is explained by the pinning condition of magnetic moment at the surface of the wire.

  16. Characterization of free radicals by electron spin resonance spectroscopy in biochars from pyrolysis at high heating rates and at high temperatures

    DEFF Research Database (Denmark)

    Trubetskaya, Anna; Jensen, Peter Arendt; Jensen, Anker Degn

    2016-01-01

    The concentration and type of free radicals from the decay (termination stage) of pyrolysis at slow and fast heating rates and at high temperatures (above 1000°C) in biomass char have been studied. A room temperature electron spin resonance spectroscopy study was conducted on original wood......, herbaceous biomass, holocelluloses, lignin and their chars, prepared at high temperatures in a wire mesh reactor, an entrained flow reactor, and a tubular reactor. The radical concentrations in the chars from the decay stage range up between 7·1016 and 1.5·1018 spins g -1. The results indicated....... The results show that at high temperatures, mostly aliphatic radicals (g = 2.0026-2.0028) and PAH radicals (g = 2.0027e2.0031) were formed....

  17. Single molecule study of a processivity clamp sliding on DNA

    Energy Technology Data Exchange (ETDEWEB)

    Laurence, T A; Kwon, Y; Johnson, A; Hollars, C; O?Donnell, M; Camarero, J A; Barsky, D

    2007-07-05

    Using solution based single molecule spectroscopy, we study the motion of the polIII {beta}-subunit DNA sliding clamp ('{beta}-clamp') on DNA. Present in all cellular (and some viral) forms of life, DNA sliding clamps attach to polymerases and allow rapid, processive replication of DNA. In the absence of other proteins, the DNA sliding clamps are thought to 'freely slide' along the DNA; however, the abundance of positively charged residues along the inner surface may create favorable electrostatic contact with the highly negatively charged DNA. We have performed single-molecule measurements on a fluorescently labeled {beta}-clamp loaded onto freely diffusing plasmids annealed with fluorescently labeled primers of up to 90 bases. We find that the diffusion constant for 1D diffusion of the {beta}-clamp on DNA satisfies D {le} 10{sup -14} cm{sup 2}/s, much slower than the frictionless limit of D = 10{sup -10} cm{sup 2}/s. We find that the {beta} clamp remains at the 3-foot end in the presence of E. coli single-stranded binding protein (SSB), which would allow for a sliding clamp to wait for binding of the DNA polymerase. Replacement of SSB with Human RP-A eliminates this interaction; free movement of sliding clamp and poor binding of clamp loader to the junction allows sliding clamp to accumulate on DNA. This result implies that the clamp not only acts as a tether, but also a placeholder.

  18. Mapping stain distribution in pathology slides using whole slide imaging

    Directory of Open Access Journals (Sweden)

    Fang-Cheng Yeh

    2014-01-01

    Full Text Available Background: Whole slide imaging (WSI offers a novel approach to digitize and review pathology slides, but the voluminous data generated by this technology demand new computational methods for image analysis. Materials and Methods: In this study, we report a method that recognizes stains in WSI data and uses kernel density estimator to calculate the stain density across the digitized pathology slides. The validation study was conducted using a rat model of acute cardiac allograft rejection and another rat model of heart ischemia/reperfusion injury. Immunohistochemistry (IHC was conducted to label ED1 + macrophages in the tissue sections and the stained slides were digitized by a whole slide scanner. The whole slide images were tessellated to enable parallel processing. Pixel-wise stain classification was conducted to classify the IHC stains from those of the background and the density distribution of the identified IHC stains was then calculated by the kernel density estimator. Results: The regression analysis showed a correlation coefficient of 0.8961 between the number of IHC stains counted by our stain recognition algorithm and that by the manual counting, suggesting that our stain recognition algorithm was in good agreement with the manual counting. The density distribution of the IHC stains showed a consistent pattern with those of the cellular magnetic resonance (MR images that detected macrophages labeled by ultrasmall superparamagnetic iron-oxide or micron-sized iron-oxide particles. Conclusions: Our method provides a new imaging modality to facilitate clinical diagnosis. It also provides a way to validate/correlate cellular MRI data used for tracking immune-cell infiltration in cardiac transplant rejection and cardiac ischemic injury.

  19. Virtual slides: application in pulmonary pathology consultations.

    Directory of Open Access Journals (Sweden)

    Michał Wojciechowski

    2008-02-01

    Full Text Available The Virtual Slide (VS is an interactive microscope emulator that presents a complete digitized tissue section via the Internet. A successful implementation of VS has been observed for educational, research venues and quality control. VS acquisition for consultative pathology is not so common. The purpose of this study was to explore the efficacy and usability of VS in the consultative pulmonary telepathology. 20 lung tumors entered the study. The performance was programmed for 2 medical centers specialized in pulmonary pathology (beginner and advancer in telepathology. A high-quality VSs were prepared by Coolscope (Nikon, Eclipsnet VSL, Japan, and were evaluated via the Internet. The cases were reviewed for the second time with conventional light microscope. VS diagnostic accuracy and the interobserver variability were evaluated. Also the time taken by examiners to render the diagnoses and time needed to scan the microscopic slide were analyzed. Percentage concordance between original glass-slides diagnosis and diagnosis for VSs was very high. Pathologists found the download speed of VSs adequate; experience in telepathology reduced the time of VS diagnosis. VS implementation suggests advantages for teleconsulation and education but also indicate some technical limitations. This is the first Polish trial of VS implementation in telepathology consultative service.

  20. Higher Spin Matrix Models

    Directory of Open Access Journals (Sweden)

    Mauricio Valenzuela

    2017-10-01

    Full Text Available We propose a hybrid class of theories for higher spin gravity and matrix models, i.e., which handle simultaneously higher spin gravity fields and matrix models. The construction is similar to Vasiliev’s higher spin gravity, but part of the equations of motion are provided by the action principle of a matrix model. In particular, we construct a higher spin (gravity matrix model related to type IIB matrix models/string theory that have a well defined classical limit, and which is compatible with higher spin gravity in A d S space. As it has been suggested that higher spin gravity should be related to string theory in a high energy (tensionless regime, and, therefore to M-Theory, we expect that our construction will be useful to explore concrete connections.

  1. Spin conversion of cytochrome b{sub 559} in photosystem II induced by exogenous high potential quinone

    Energy Technology Data Exchange (ETDEWEB)

    Kropacheva, Tatyana N.; Feikema, W. Onno; Mamedov, Fikret; Feyziyev, Yashar; Styring, Stenbjorn; Hoff, Arnold J

    2003-11-01

    The spin-state of cytochrome b{sub 559} (Cyt b{sub 559}) was studied in photosystem II (PSII) membrane fragments by low-temperature EPR spectroscopy. Treatment of the membranes with 2,3-dichloro-5,6-dicyano-p-benzoquinone (DDQ) converts the native low-spin (LS) form of Cyt b{sub 559} to the high-spin (HS) form characterized with the g= 6.19 and g= 5.95 split signal. The HS Cyt b{sub 559} was pH dependent with the amplitude increasing toward more acidic pH values (pH 5.5-8.5). The HS state was not photochemically active upon 77 and 200 K continuous illumination under our conditions and was characterized by a low reduction potential ({<=}0 V). It was also demonstrated that DDQ treatment damages the oxygen evolving complex, leading to inhibition of oxygen evolution, decrease of the S{sub 2}-state EPR multiline signal and release of Mn{sup 2+}. In parallel, studies of model systems containing iron(III) protoporphyrin IX chloride (Fe{sup III}Por), which is a good model compound for the Cyt b{sub 559} prosthetic group, were performed by using optical and EPR spectroscopy. The interaction of Fe{sup III}Por with imidazole (Im) in weakly polar solvent results in formation of bis-imidazole coordinated heme iron (Fe{sup III}Por Im{sub 2}) which mimic the bis-histidine axial ligation of Cyt b{sub 559}. The reaction of DDQ with the LS Fe{sup III}Por Im{sub 2} complex leads to its transformation into the HS state (g{sub perpendicular}=5.95, g{sub parallel}=2.00). It was shown that the spin conversion occurs due to the donor-acceptor interaction of coordinated imidazole with this high-potential quinone causing the displacement of imidazole from the axial position. The similar mechanism of DDQ-induced spin change is assumed to be valid for the native membrane Cyt b{sub 559} in PSII centers.

  2. Chemical profile of beans cultivars (Phaseolus vulgaris) by 1H NMR - high resolution magic angle spinning (HR-MAS);Perfil quimico de cultivares de feijao (Phaseolus vulgaris) pela tecnica de high resolution magic angle spinning (HR-MAS)

    Energy Technology Data Exchange (ETDEWEB)

    Liao, Luciano Morais; Choze, Rafael; Cavalcante, Pedro Paulo Araujo; Santos, Suzana da Costa; Ferri, Pedro Henrique, E-mail: luciano@quimica.ufg.b [Universidade Federal de Goias (UFG), Goiania, GO (Brazil). Inst. de Quimica; Ferreira, Antonio Gilberto [Universidade Federal de Sao Carlos (UFScar), SP (Brazil). Dept. de Quimica

    2010-07-01

    The application of one-dimensional proton high-resolution magic angle spinning ({sup 1}H HR-MAS) NMR combined with a typical advantages of solid and liquid-state NMR techniques was used as input variables for the multivariate statistical analysis. In this paper, different cultivars of beans (Phaseolus vulgaris) developed and in development by EMBRAPA - Arroz e Feijao were analyzed by {sup 1}H HR-MAS, which have been demonstrated to be a valuable tool in its differentiation according chemical composition and avoid the manipulation of the samples as used in other techniques. (author)

  3. Measurements of nuclear spin dynamics by spin-noise spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Ryzhov, I. I.; Poltavtsev, S. V.; Kozlov, G. G.; Zapasskii, V. S. [Spin Optics Laboratory, St. Petersburg State University, 1 Ul' anovskaya, Peterhof, St. Petersburg 198504 (Russian Federation); Kavokin, K. V.; Glazov, M. M. [Spin Optics Laboratory, St. Petersburg State University, 1 Ul' anovskaya, Peterhof, St. Petersburg 198504 (Russian Federation); Ioffe Institute, Russian Academy of Sciences, 26 Polytechnicheskaya, St.-Petersburg 194021 (Russian Federation); Vladimirova, M.; Scalbert, D.; Cronenberger, S. [Laboratoire Charles Coulomb UMR 5221 CNRS/Université de Montpellier, Place Eugene Bataillon, 34095 Montpellier Cedex 05 (France); Kavokin, A. V. [Spin Optics Laboratory, St. Petersburg State University, 1 Ul' anovskaya, Peterhof, St. Petersburg 198504 (Russian Federation); School of Physics and Astronomy, University of Southampton, SO17 1NJ Southampton (United Kingdom); Lemaître, A.; Bloch, J. [Laboratoire de Photonique et de Nanostructures, UPR CNRS, Route de Nozay, 91460 Marcoussis (France)

    2015-06-15

    We exploit the potential of the spin noise spectroscopy (SNS) for studies of nuclear spin dynamics in n-GaAs. The SNS experiments were performed on bulk n-type GaAs layers embedded into a high-finesse microcavity at negative detuning. In our experiments, nuclear spin polarisation initially prepared by optical pumping is monitored in real time via a shift of the peak position in the electron spin noise spectrum. We demonstrate that this shift is a direct measure of the Overhauser field acting on the electron spin. The dynamics of nuclear spin is shown to be strongly dependent on the electron concentration.

  4. Coexistence of magnetic fluctuations and superconductivity in the pnictide high temperature superconductor SmFeAsO1-xFx measured by muon spin rotation.

    Science.gov (United States)

    Drew, A J; Pratt, F L; Lancaster, T; Blundell, S J; Baker, P J; Liu, R H; Wu, G; Chen, X H; Watanabe, I; Malik, V K; Dubroka, A; Kim, K W; Rössle, M; Bernhard, C

    2008-08-29

    Muon spin rotation experiments were performed on the pnictide high temperature superconductor SmFeAsO1-xFx with x=0.18 and 0.3. We observed an unusual enhancement of slow spin fluctuations in the vicinity of the superconducting transition which suggests that the spin fluctuations contribute to the formation of an unconventional superconducting state. An estimate of the in-plane penetration depth lambda ab(0)=190(5) nm was obtained, which confirms that the pnictide superconductors obey an Uemura-style relationship between Tc and lambda ab(0);(-2).

  5. Quantification of Estrogen Receptor-Alpha Expression in Human Breast Carcinomas With a Miniaturized, Low-Cost Digital Microscope: A Comparison with a High-End Whole Slide-Scanner.

    Science.gov (United States)

    Holmström, Oscar; Linder, Nina; Lundin, Mikael; Moilanen, Hannu; Suutala, Antti; Turkki, Riku; Joensuu, Heikki; Isola, Jorma; Diwan, Vinod; Lundin, Johan

    2015-01-01

    A significant barrier to medical diagnostics in low-resource environments is the lack of medical care and equipment. Here we present a low-cost, cloud-connected digital microscope for applications at the point-of-care. We evaluate the performance of the device in the digital assessment of estrogen receptor-alpha (ER) expression in breast cancer samples. Studies suggest computer-assisted analysis of tumor samples digitized with whole slide-scanners may be comparable to manual scoring, here we study whether similar results can be obtained with the device presented. A total of 170 samples of human breast carcinoma, immunostained for ER expression, were digitized with a high-end slide-scanner and the point-of-care microscope. Corresponding regions from the samples were extracted, and ER status was determined visually and digitally. Samples were classified as ER negative (microscope and the manual scoring was good (r = 0.94, p microscope, all representing samples of low ER expression. Tumor ER status can be accurately quantified with a low-cost imaging device and digital image-analysis, with results comparable to conventional computer-assisted or manual scoring. This technology could potentially be expanded for other histopathological applications at the point-of-care.

  6. Energy of the surface layer deterioration of 1020 steel and copper at dry sliding against 1045 steel with a high electric current density

    Science.gov (United States)

    Fadin, V. V.; Aleutdinova, M. I.; Rubtsov, V. E.

    2016-11-01

    Dry sliding of copper and 1020 steel against 1045 steel under the influence of the contact current density higher than 250 A/cm2 is carried out by using the pin-on-ring testing scheme. The change in the surface layer structure and the formation of a tribolayer consisting of iron, copper, and FeO oxide are shown. It is noted that the thin contact layer contains near 40 at % of oxygen. The specific wear rate is calculated based on the data of wear and current-voltage characteristics of the contact. A limited applicability of this parameter for the description of the surface layer deterioration is shown. We propose a wear parameter close to it, which characterizes more correctly the specimen tribolayer deterioration. These wear characteristics increase with a current density increase. It is established that the work of tribolayer deterioration can be close to a half of energy generated in contact. Some increase in the work of tribolayer deterioration due to a reduction in heat flow to the specimen is noted. It is shown that these wear characteristics of copper are considerably lower than that of 1020 steel. It is explained by the presence of copper in the tribolayer of the copper specimen that allows an easier stress relaxation to be realized.

  7. Mechanism of opening a sliding clamp.

    Science.gov (United States)

    Douma, Lauren G; Yu, Kevin K; England, Jennifer K; Levitus, Marcia; Bloom, Linda B

    2017-09-29

    Clamp loaders load ring-shaped sliding clamps onto DNA where the clamps serve as processivity factors for DNA polymerases. In the first stage of clamp loading, clamp loaders bind and stabilize clamps in an open conformation, and in the second stage, clamp loaders place the open clamps around DNA so that the clamps encircle DNA. Here, the mechanism of the initial clamp opening stage is investigated. Mutations were introduced into the Escherichia coli β-sliding clamp that destabilize the dimer interface to determine whether the formation of an open clamp loader-clamp complex is dependent on spontaneous clamp opening events. In other work, we showed that mutation of a positively charged Arg residue at the β-dimer interface and high NaCl concentrations destabilize the clamp, but neither facilitates the formation of an open clamp loader-clamp complex in experiments presented here. Clamp opening reactions could be fit to a minimal three-step 'bind-open-lock' model in which the clamp loader binds a closed clamp, the clamp opens, and subsequent conformational rearrangements 'lock' the clamp loader-clamp complex in a stable open conformation. Our results support a model in which the E. coli clamp loader actively opens the β-sliding clamp. © The Author(s) 2017. Published by Oxford University Press on behalf of Nucleic Acids Research.

  8. Managing and querying whole slide images

    Science.gov (United States)

    Wang, Fusheng; Oh, Tae W.; Vergara-Niedermayr, Cristobal; Kurc, Tahsin; Saltz, Joel

    2012-02-01

    High-resolution pathology images provide rich information about the morphological and functional characteristics of biological systems, and are transforming the field of pathology into a new era. To facilitate the use of digital pathology imaging for biomedical research and clinical diagnosis, it is essential to manage and query both whole slide images (WSI) and analytical results generated from images, such as annotations made by humans and computed features and classifications made by computer algorithms. There are unique requirements on modeling, managing and querying whole slide images, including compatibility with standards, scalability, support of image queries at multiple granularities, and support of integrated queries between images and derived results from the images. In this paper, we present our work on developing the Pathology Image Database System (PIDB), which is a standard oriented image database to support retrieval of images, tiles, regions and analytical results, image visualization and experiment management through a unified interface and architecture. The system is deployed for managing and querying whole slide images for In Silico brain tumor studies at Emory University. PIDB is generic and open source, and can be easily used to support other biomedical research projects. It has the potential to be integrated into a Picture Archiving and Communications System (PACS) with powerful query capabilities to support pathology imaging.

  9. Multiple-quantum magic-angle spinning: high-resolution solid state NMR spectroscopy of half-integer quadrupolar nuclei

    CERN Document Server

    Goldbourt, A

    2002-01-01

    Experimental and theoretical aspects of the multiple-quantum magic-angle spinning experiment (MQMAS) are discussed in this review. The significance of this experiment, introduced by Frydman and Harwood, is in its ability to provide high-resolution NMR spectra of half-integer quadrupolar nuclei (I /geq 3/2). This technique has proved to be useful in various systems ranging from inorganic materials to biological samples. This review addresses the development of various pulse schemes aimed at improving the signal-to-noise ratio and anisotropic lineshapes. Representative spectra are shown to underscore the importance and applications of the MQMAS experiment. Refs. 97 (author)

  10. Low-lying levels and high-spin band structures in sup 1 sup 0 sup 2 Rh

    CERN Document Server

    Gizon, J; Timar, J; Cata-Danil, G; Nyakó, B M; Zolnai, L; Boston, A J; Joss, D T; Paul, E S; Semple, A T; O'Brien, N J; Parry, C M; Bucurescu, D; Brant, S; Paar, V

    1999-01-01

    Levels in sup 1 sup 0 sup 2 Rh have been populated in the reaction sup 7 sup 0 Zn+ sup 3 sup 6 S at 130 MeV. The level structure of sup 1 sup 0 sup 2 Rh has been investigated using the EUROGAM II array. Low-lying states and four high-spin bands have been identified. The configurations of low-lying levels and two-quasiparticle bands are interpreted in the frame of the interacting boson-fermion-fermion model. The four observed band structures are also compared with cranked shell model calculations using a modified oscillator potential.

  11. Magic angle spinning nuclear magnetic resonance apparatus and process for high-resolution in situ investigations

    Science.gov (United States)

    Hu, Jian Zhi; Sears, Jr., Jesse A.; Hoyt, David W.; Mehta, Hardeep S.; Peden, Charles H. F.

    2015-11-24

    A continuous-flow (CF) magic angle sample spinning (CF-MAS) NMR rotor and probe are described for investigating reaction dynamics, stable intermediates/transition states, and mechanisms of catalytic reactions in situ. The rotor includes a sample chamber of a flow-through design with a large sample volume that delivers a flow of reactants through a catalyst bed contained within the sample cell allowing in-situ investigations of reactants and products. Flow through the sample chamber improves diffusion of reactants and products through the catalyst. The large volume of the sample chamber enhances sensitivity permitting in situ .sup.13C CF-MAS studies at natural abundance.

  12. Intra-arterial high signals on arterial spin labeling perfusion images predict the occluded internal carotid artery segment

    Energy Technology Data Exchange (ETDEWEB)

    Sogabe, Shu; Satomi, Junichiro; Tada, Yoshiteru; Kanematsu, Yasuhisa; Kuwayama, Kazuyuki; Yagi, Kenji; Yoshioka, Shotaro; Mizobuchi, Yoshifumi; Mure, Hideo; Yamaguchi, Izumi; Kitazato, Keiko T.; Nagahiro, Shinji [Tokushima University Graduate School, Department of Neurosurgery, Tokushima (Japan); Abe, Takashi; Harada, Masafumi [Tokushima University Graduate School, Department of Radiology, Tokushima (Japan); Yamamoto, Nobuaki; Kaji, Ryuji [Tokushima University Graduate School, Department of Clinical Neurosciences, Institute of Biomedical Biosciences, Tokushima (Japan)

    2017-06-15

    Arterial spin labeling (ASL) involves perfusion imaging using the inverted magnetization of arterial water. If the arterial arrival times are longer than the post-labeling delay, labeled spins are visible on ASL images as bright, high intra-arterial signals (IASs); such signals were found within occluded vessels of patients with acute ischemic stroke. The identification of the occluded segment in the internal carotid artery (ICA) is crucial for endovascular treatment. We tested our hypothesis that high IASs on ASL images can predict the occluded segment. Our study included 13 patients with acute ICA occlusion who had undergone angiographic and ASL studies within 48 h of onset. We retrospectively identified the high IAS on ASL images and angiograms and recorded the occluded segment and the number of high IAS-positive slices on ASL images. The ICA segments were classified as cervical (C1), petrous (C2), cavernous (C3), and supraclinoid (C4). Of seven patients with intracranial ICA occlusion, five demonstrated high IASs at C1-C2, suggesting that high IASs could identify stagnant flow proximal to the occluded segment. Among six patients with extracranial ICA occlusion, five presented with high IASs at C3-C4, suggesting that signals could identify the collateral flow via the ophthalmic artery. None had high IASs at C1-C2. The mean number of high IAS-positive slices was significantly higher in patients with intra- than extracranial ICA occlusion. High IASs on ASL images can identify slow stagnant and collateral flow through the ophthalmic artery in patients with acute ICA occlusion and help to predict the occlusion site. (orig.)

  13. Fuzzy Backstepping Sliding Mode Control for Mismatched Uncertain System

    Directory of Open Access Journals (Sweden)

    H. Q. Hou

    2014-06-01

    Full Text Available Sliding mode controllers have succeeded in many control problems that the conventional control theories have difficulties to deal with; however it is practically impossible to achieve high-speed switching control. Therefore, in this paper an adaptive fuzzy backstepping sliding mode control scheme is derived for mismatched uncertain systems. Firstly fuzzy sliding mode controller is designed using backstepping method based on the Lyapunov function approach, which is capable of handling mismatched problem. Then fuzzy sliding mode controller is designed using T-S fuzzy model method, it can improve the performance of the control systems and their robustness. Finally this method of control is applied to nonlinear system as a case study; simulation results are also provided the performance of the proposed controller.

  14. Energy distributions at the high-spin ferric sites in myoglobin crystals.

    Science.gov (United States)

    Fiamingo, F G; Brill, A S; Hampton, D A; Thorkildsen, R

    1989-01-01

    The orientation and temperature dependence (4.2-2.5 K) of electron paramagnetic resonance (EPR) power saturation and spin-lattice relaxation rate, and the orientation dependence of signal linewidth, were measured in single crystals of the aquo complex of ferric sperm whale skeletal muscle myoglobin. The spin-packet linewidth was found to be temperature independent and to vary by a factor of seven within the heme plane. An analysis is presented which enables one to arrive at (a) hyperfine component line-widths and, from the in-plane angular variation of the latter, at (b) the widths of distributions in energy differences between low-lying electronic levels and (c) the angular spread in the in-plane principal g-directions. The values of the energy level distributions in crystals obtained from the measurements and analysis reported here are compared with those obtained by a different method for the same protein complex in frozen solution. The spread in the rhombic energy splitting is significantly greater in solution than in the crystal. PMID:2539208

  15. Analytical high-order post-Newtonian expansions for spinning extreme mass ratio binaries

    CERN Document Server

    Kavanagh, Chris; Wardell, Barry

    2016-01-01

    We present an analytic computation of Detweiler's redshift invariant for a point mass in a circular orbit around a Kerr black hole, giving results up to 8.5 post-Newtonian order while making no assumptions on the magnitude of the spin of the black hole. Our calculation is based on the functional series method of Mano, Suzuki and Takasugi, and employs a rigorous mode-sum regularization prescription based on the Detweiler-Whiting singular-regular decomposition. The approximations used in our approach are minimal; we use the standard self-force expansion to linear order in the mass ratio, and the standard post-Newtonian expansion in the separation of the binary. A key advantage of this approach is that it produces expressions that include contributions at all orders in the spin of the Kerr black hole. While this work applies the method to the specific case of Detweiler's redshift invariant, it can be readily extended to other gauge invariant quantities and to higher post-Newtonian orders.

  16. Effects of impurities and vortices on the low-energy spin excitations in high-Tc materials

    DEFF Research Database (Denmark)

    Andersen, Brian Møller; Graser, S.; Schmid, M.

    2011-01-01

    a quasi-long range ordered state. When correlations are sufficiently strong, disorder is unimportant for the generation of static magnetism but plays an additional role of pinning disordered stripe configurations. We calculate the spin excitations in a disordered spin-density wave phase, and show how...... disorder and/or applied magnetic fields lead to a slowing down of the dynamical spin fluctuations in agreement with neutron scattering and muon spin rotation (mSR) experiments....

  17. Slide-based ergometer rowing

    DEFF Research Database (Denmark)

    Vinther, Anders; Alkjær, T; Kanstrup, I-L

    2012-01-01

    Force production profile and neuromuscular activity during slide-based and stationary ergometer rowing at standardized submaximal power output were compared in 14 male and 8 female National Team rowers. Surface electromyography (EMG) was obtained in selected thoracic and leg muscles along with sy...

  18. SlideDog / Siim Sein

    Index Scriptorium Estoniae

    Sein, Siim

    2015-01-01

    SlideDog on multimeediumi esitluse tööriist, mis võimaldab ühendada PowerPointi esitlused, PDF-failid, Prezi esitlused, videoklipid, helifailid, veebilehed ja palju muud üheks sujuvaks esitluskogemuseks konverentsil, seminaril või muul üritusel

  19. PREFACE: Spin Electronics

    Science.gov (United States)

    Dieny, B.; Sousa, R.; Prejbeanu, L.

    2007-04-01

    Conventional electronics has in the past ignored the spin on the electron, however things began to change in 1988 with the discovery of giant magnetoresistance in metallic thin film stacks which led to the development of a new research area, so called spin-electronics. In the last 10 years, spin-electronics has achieved a number of breakthroughs from the point of view of both basic science and application. Materials research has led to several major discoveries: very large tunnel magnetoresistance effects in tunnel junctions with crystalline barriers due to a new spin-filtering mechanism associated with the spin-dependent symmetry of the electron wave functions new magnetic tunnelling barriers leading to spin-dependent tunnelling barrier heights and acting as spin-filters magnetic semiconductors with increasingly high ordering temperature. New phenomena have been predicted and observed: the possibility of acting on the magnetization of a magnetic nanostructure with a spin-polarized current. This effect, due to a transfer of angular momentum between the spin polarized conduction electrons and the local magnetization, can be viewed as the reciprocal of giant or tunnel magnetoresistance. It can be used to switch the magnetization of a magnetic nanostructure or to generate steady magnetic excitations in the system. the possibility of generating and manipulating spin current without charge current by creating non-equilibrium local accumulation of spin up or spin down electrons. The range of applications of spin electronics materials and phenomena is expanding: the first devices based on giant magnetoresistance were the magnetoresistive read-heads for computer disk drives. These heads, introduced in 1998 with current-in plane spin-valves, have evolved towards low resistance tunnel magnetoresistice heads in 2005. Besides magnetic recording technology, these very sensitive magnetoresistive sensors are finding applications in other areas, in particular in biology. magnetic

  20. Sliding-slab three-dimensional TSE imaging with a spiral-In/Out readout.

    Science.gov (United States)

    Li, Zhiqiang; Wang, Dinghui; Robison, Ryan K; Zwart, Nicholas R; Schär, Michael; Karis, John P; Pipe, James G

    2016-02-01

    T2 -weighted imaging is of great diagnostic value in neuroimaging. Three-dimensional (3D) Cartesian turbo spin echo (TSE) scans provide high signal-to-noise ratio (SNR) and contiguous slice coverage. The purpose of this preliminary work is to implement a novel 3D spiral TSE technique with image quality comparable to 2D/3D Cartesian TSE. The proposed technique uses multislab 3D TSE imaging. To mitigate the slice boundary artifacts, a sliding-slab method is extended to spiral imaging. A spiral-in/out readout is adopted to minimize the artifacts that may be present with the conventional spiral-out readout. Phase errors induced by B0 eddy currents are measured and compensated to allow for the combination of the spiral-in and spiral-out images. A nonuniform slice encoding scheme is used to reduce the truncation artifacts while preserving the SNR performance. Preliminary results show that each of the individual measures contributes to the overall performance, and the image quality of the results obtained with the proposed technique is, in general, comparable to that of 2D or 3D Cartesian TSE. 3D sliding-slab TSE with a spiral-in/out readout provides good-quality T2 -weighted images, and, therefore, may become a promising alternative to Cartesian TSE. © 2015 Wiley Periodicals, Inc.

  1. Study of spin-exchange optically pumped {sup 3}He cells with high polarisation and long lifetimes

    Energy Technology Data Exchange (ETDEWEB)

    Parnell, S.R. [Academic Unit of Radiology, University of Sheffield, Sheffield S10 2JF (United Kingdom); ISIS Neutron and Muon Facility, Rutherford Appleton Laboratory, Chilton, Didcot, Oxfordshire OX11 0QX (United Kingdom)], E-mail: s.r.parnell@sheffield.ac.uk; Babcock, E. [Insitut Laue-Langevin, 6, rue J. Horowitz, F-38042 Grenoble Cedex 9 (France); Nuenighoff, K. [Institut fuer Festkoerperforschung, Forschungszentrum Juelich, 52425 Juelich (Germany); Skoda, M.W.A.; Boag, S. [ISIS Neutron and Muon Facility, Rutherford Appleton Laboratory, Chilton, Didcot, Oxfordshire OX11 0QX (United Kingdom); Masalovich, S. [Neutronenforschungsquelle Heinz Maier-Leibnitz, Technische Universitaet Muenchen, Lichtenbergstr, 1, 85747 Garching (Germany); Chen, W.C. [National Institute of Standards and Technology (NIST), Gaithersburg, MD 20899 (United States); Georgii, R. [Neutronenforschungsquelle Heinz Maier-Leibnitz, Technische Universitaet Muenchen, Lichtenbergstr, 1, 85747 Garching (Germany); Wild, J.M. [Academic Unit of Radiology, University of Sheffield, Sheffield S10 2JF (United Kingdom); Frost, C.D. [ISIS Neutron and Muon Facility, Rutherford Appleton Laboratory, Chilton, Didcot, Oxfordshire OX11 0QX (United Kingdom)

    2009-01-21

    We present a detailed investigation into {sup 3}He neutron spin filter cells polarised by spin exchange optical pumping (SEOP). We include measurements of the absolute {sup 3}He polarisation using neutron transmission and characterisation of both the X-factor and {sup 3}He relaxation times (T{sub 1}) for a number of cells. For one cell we calculated a maximum {sup 3}He polarisation of 79% with a T{sub 1} of 633 h. The measured X-factor of this cell, X=0.17{+-}0.01, is low. For all cells polarisations of >71% are observed. In addition we present {sup 3}He relaxation data for a new design of magneto-static cavity with a field of high homogeneity {delta}B/B{sub 0}{approx}3.5x10{sup -4}cm{sup -1}. This compact device provides a magnetic field in an orientation suitable for in situ optical pumping that minimises the field inhomogeneity contribution to the T{sub 1} to 930 h in a 1 bar cell, the longest reported on beam thus far. The results suggest that high {sup 3}He polarisation with long relaxation times can now be routinely obtained with SEOP, enabling time independent incident beam polarisation to be easily implemented across many different neutron scattering instruments.

  2. Should three slide-touch print cytology replace pleural lavage cytology for detection of pleural micrometastases in cases of bronchogenic carcinoma?

    Science.gov (United States)

    Alayouty, Hamdy D; Amin, Morsy Mohamed; Aloukda, Ausama W; Bafakeer, Salim S; Sulieman, Dhafir Dawood

    2011-05-01

    A prospective study, including 112 patients, designed to estimate the sensitivity and specificity of slide-touch and pleural lavage cytology for diagnosis of pleural micrometastases in operable non-small cell lung cancer (NSCLC). Histopathologically, excised tumors showed P0 in 22 patients (19%), P1 in 44 patients (39%), P2 in 32 patients (29%), P3 in 14 patients (13%). Cytological examination of the three slide-touch prints from visceral pleura overlying the tumor (slide 1), parietal pleura facing tumor (slide 2), parietal pleura in paravertebral gutter (slide 3) resulted in: slide 1: positive in 60% (66/112) [this included p0 (2 out of 22), p1 (22 out of 44), p2 (32 out of 32) and p3 (10 out of 14)], slide 2: positive in 13% (14/112); all of them had P3, and slide 3 positive in 8% (9/112). Total positive slides 62% (70/112). Pleural lavage: positive in 19% (22/112), all of them were detected with slide 1 and/or slide 2. During follow-up, patients with negative slides had no local or distant metastases (truly negative), six recurrences among those with positive slide 1, including four with positive lavage. Thus, slide touch print is more sensitive than lavage cytology, both of prognostic significance. Slide 1 is a highly sensitive detector of visceral pleural micrometastases; slide 2 is a more sensitive detector of parietal pleural invasion; slide 3 is the least.

  3. Longitudinal double spin asymmetries in single hadron quasi-real photoproduction at high pT

    Directory of Open Access Journals (Sweden)

    C. Adolph

    2016-02-01

    Full Text Available We measured the longitudinal double spin asymmetries ALL for single hadron muoproduction off protons and deuterons at photon virtuality Q2<1(GeV/c2 for transverse hadron momenta pT in the range 1 GeV/c to 4 GeV/c. They were determined using COMPASS data taken with a polarised muon beam of 160 GeV/c or 200 GeV/c impinging on polarised 6LiD or NH3 targets. The experimental asymmetries are compared to next-to-leading order pQCD calculations, and are sensitive to the gluon polarisation ΔG inside the nucleon in the range of the nucleon momentum fraction carried by gluons 0.05

  4. Longitudinal double spin asymmetries in single hadron quasi-real photoproduction at high $p_T$

    CERN Document Server

    Adolph, C; Alexeev, M G; Alexeev, G D; Amoroso, A; Andrieux, V; Anosov, V; Augustyniak, W; Austregesilo, A; Azevedo, C D R; Badełek, B; Balestra, F; Barth, J; Beck, R; Bedfer, Y; Bernhard, J; Bicker, K; Bielert, E R; Birsa, R; Bisplinghoff, J; Bodlak, M; Boer, M; Bordalo, P; Bradamante, F; Braun, C; Bressan, A; Büchele, M; Burtin, E; Chang, W-C; Chiosso, M; Choi, I; Chung, S U; Cicuttin, A; Crespo, M L; Curiel, Q; Dalla Torre, S; Dasgupta, S S; Dasgupta, S; Denisov, O Yu; Dhara, L; Donskov, S V; Doshita, N; Duic, V; Dünnweber, W; Dziewiecki, M; Efremov, A; Eversheim, P D; Eyrich, W; Faessler, M; Ferrero, A; Finger, M; Finger jr , M; Fischer, H; Franco, C; du Fresne von Hohenesche, N; Friedrich, J M; Frolov, V; Fuchey, E; Gautheron, F; Gavrichtchouk, O P; Gerassimov, S; Giordano, F; Gnesi, I; Gorzellik, M; Grabmüller, S; Grasso, A; Grosse Perdekamp, M; Grube, B; Grussenmeyer, T; Guskov, A; Haas, F; Hahne, D; von Harrach, D; Hashimoto, R; Heinsius, F H; Herrmann, F; Hinterberger, F; Horikawa, N; d'Hose, N; Hsieh, C-Y; Huber, S; Ishimoto, S; Ivanov, A; Ivanshin, Yu; Iwata, T; Jahn, R; Jary, V; Joosten, R; Jörg, P; Kabuß, E; Ketzer, B; Khaustov, G V; Khokhlov, Yu A; Kisselev, Yu; Klein, F; Klimaszewski, K; Koivuniemi, J H; Kolosov, V N; Kondo, K; Königsmann, K; Konorov, I; Konstantinov, V F; Kotzinian, A M; Kouznetsov, O; Krämer, M; Kremser, P; Krinner, F; Kroumchtein, Z V; Kuchinski, N; Kuhn, R; Kunne, F; Kurek, K; Kurjata, R P; Lednev, A A; Lehmann, A; Levillain, M; Levorato, S; Lichtenstadt, J; Longo, R; Maggiora, A; Magnon, A; Makins, N; Makke, N; Mallot, G K; Marchand, C; Marianski, B; Martin, A; Marzec, J; Matoušek, J; Matsuda, H; Matsuda, T; Meshcheryakov, G; Meyer, W; Michigami, T; Mikhailov, Yu V; Miyachi, Y; Montuenga, P; Nagaytsev, A; Nerling, F; Neyret, D; Nikolaenko, V I; Nový, J; Nowak, W-D; Nukazuka, G; Nunes, A S; Olshevsky, A G; Orlov, I; Ostrick, M; Panzieri, D; Parsamyan, B; Paul, S; Peng, J-C; Pereira, F; Pešek, M; Peshekhonov, D V; Platchkov, S; Pochodzalla, J; Polyakov, V A; Pretz, J; Quaresma, M; Quintans, C; Ramos, S; Regali, C; Reicherz, G; Riedl, C; Rossiyskaya, N S; Ryabchikov, D I; Rychter, A; Samoylenko, V D; Sandacz, A; Santos, C; Sarkar, S; Savin, I A; Sbrizzai, G; Schiavon, P; Schmidt, K; Schmieden, H; Schönning, K; Schopferer, S; Selyunin, A; Shevchenko, O Yu; Silva, L; Sinha, L; Sirtl, S; Slunecka, M; Sozzi, F; Srnka, A; Stolarski, M; Sulc, M; Suzuki, H; Szabelski, A; Szameitat, T; Sznajder, P; Takekawa, S; Tessaro, S; Tessarotto, F; Thibaud, F; Tosello, F; Tskhay, V; Uhl, S; Veloso, J; Virius, M; Weisrock, T; Wilfert, M; ter Wolbeek, J; Zaremba, K; Zavertyaev, M; Zemlyanichkina, E; Ziembicki, M; Zink, A

    2016-01-01

    We measured the longitudinal double spin asymmetries $A_{LL}$ for single hadron muo-production off protons and deuterons at photon virtuality $Q^2$ < 1(GeV/$\\it c$)$^2$ for transverse hadron momenta $p_T$ in the range 0.7 GeV/$\\it c$ to 4 GeV/$\\it c$ . They were determined using COMPASS data taken with a polarised muon beam of 160 GeV/$\\it c$ or 200 GeV/$\\it c$ impinging on polarised $\\mathrm{{}^6LiD}$ or $\\mathrm{NH_3}$ targets. The experimental asymmetries are compared to next-to-leading order pQCD calculations, and are sensitive to the gluon polarisation $\\Delta G$ inside the nucleon in the range of the nucleon momentum fraction carried by gluons $0.05 < x_g < 0.2$.

  5. Whole slide imaging in pathology: advantages, limitations, and emerging perspectives

    Directory of Open Access Journals (Sweden)

    Farahani N

    2015-06-01

    Full Text Available Navid Farahani,1 Anil V Parwani,2 Liron Pantanowitz2 1Department of Pathology and Laboratory Medicine, Cedars-Sinai Medical Center, Los Angeles, CA, USA; 2Department of Pathology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA Abstract: Significant technologic gains have led to the adoption of innovative digital imaging solutions in pathology. Whole slide imaging (WSI, which refers to scanning of conventional glass slides in order to produce digital slides, is the most recent imaging modality being employed by pathology departments worldwide. WSI continues to gain traction among pathologists for diagnostic, educational, and research purposes. This article provides a technologic review of WSI platforms and covers clinical and nonclinical pathology applications of these imaging systems. Barriers to adoption of WSI include limiting technology, image quality, problems with scanning all materials (eg, cytology slides, cost, digital slide storage, inability to handle high-throughput routine work, regulatory barriers, ergonomics, and pathologists' reluctance. Emerging issues related to clinical validation, standardization, and forthcoming advances in the field are also addressed. Keywords: digital, imaging, microscopy, pathology, validation, whole slide image, telepathology

  6. Automobile Road Vibration Reproduction using Sliding Modes

    NARCIS (Netherlands)

    Monsees, G.; Scherpen, J.M.A.

    2001-01-01

    Sliding mode controllers have a reputation for their robustness against parameter variations, modeling errors and disturbances. They have been successfully applied in several practical situations which demonstrated the potential of sliding mode control for other control problems. However research

  7. Ball's motion, sliding friction, and internal load distribution in a high-speed ball bearing subjected to a combined radial, thrust, and moment load, applied to the inner ring's center of mass: Numerical procedure

    Science.gov (United States)

    César Ricci, Mário

    2015-10-01

    In a companion paper of this was introduced a set of non-linear algebraic equations for ball's motion, sliding friction and internal loading distribution computation in a high-speed, single-row, angular-contact ball bearing, subjected to a known combined radial, thrust and moment load, which must be applied to the inner ring's center of mass. It was shown there that it is required the iterative solution of 9Z + 3 simultaneous non-linear equations - where Z is the number of balls - to yield exact solution for contact angles, ball attitude angles, rolling radii, normal contact deformations and axial, radial, and angular deflections of the inner ring with respect the outer ring. The Newton-Rhapson method is to be used to solve the problem. This paper deals with the numerical procedure description. The numerical results derived from the described procedure shall be published later.

  8. Pressure-induced hysteresis in the high spin {r_reversible} low spin transition in bis(2,4-bis(pyridin-2-yl)thiazole) iron(II) tetrafluoroborate

    Energy Technology Data Exchange (ETDEWEB)

    Bhattacharjee, A; Ksenofontov, V; Guetlich, P [Institut fuer Anorganische Chemie und Analytische Chemie, Johannes-Gutenberg Universitaet, D-55099 Mainz (Germany); Goodwin, H A [School of Chemistry, University of New South Wales, Sydney, NSW 2052 (Australia)], E-mail: ashis.bhattacharjee@visva-bharati.ac.in, E-mail: guetlich@uni-mainz.de

    2009-01-14

    Studies of the spin transition behavior of the mononuclear compound [Fe(pythiaz){sub 2}](BF{sub 4}){sub 2} have been carried out under hydrostatic pressures up to 9.13 kbar in the 5-300 K temperature range. Under ambient pressure this compound exhibits an approximately half-step (incomplete) HS {r_reversible} LS transition with T{sub 1/2} = 146 K without any thermal hysteresis. At pressures up to 4.5 kbar the behavior remains similar but with an upward displacement of T{sub 1/2} and a slight decrease in the residual high spin fraction at low T. Application of higher pressures resulted in an almost complete two-step spin transition with several unusual pressure effects. Along with the expected pressure dependence of T{sub 1/2} the surprising appearance of hysteresis in the spin transition curves was observed. It is suggested that the likely origin of this unprecedented behavior is a pressure-induced structural change.

  9. Pressure-induced hysteresis in the high spin [Formula: see text] low spin transition in bis(2,4-bis(pyridin-2-yl)thiazole) iron(II) tetrafluoroborate.

    Science.gov (United States)

    Bhattacharjee, A; Ksenofontov, V; Goodwin, H A; Gütlich, P

    2009-01-14

    Studies of the spin transition behavior of the mononuclear compound [Fe(pythiaz)(2)](BF(4))(2) have been carried out under hydrostatic pressures up to 9.13 kbar in the 5-300 K temperature range. Under ambient pressure this compound exhibits an approximately half-step (incomplete) HS [Formula: see text] LS transition with T(1/2) = 146 K without any thermal hysteresis. At pressures up to 4.5 kbar the behavior remains similar but with an upward displacement of T(1/2) and a slight decrease in the residual high spin fraction at low T. Application of higher pressures resulted in an almost complete two-step spin transition with several unusual pressure effects. Along with the expected pressure dependence of T(1/2) the surprising appearance of hysteresis in the spin transition curves was observed. It is suggested that the likely origin of this unprecedented behavior is a pressure-induced structural change.

  10. Spin-flipping polarized electrons

    Directory of Open Access Journals (Sweden)

    V. S. Morozov

    2001-10-01

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

  11. Control over the magnetism and transition between high- and low-spin states of an adatom on trilayer graphene.

    Science.gov (United States)

    Zheng, Anmin; Gao, Guoying; Huang, Hai; Gao, Jinhua; Yao, Kailun

    2017-05-31

    Using density-functional theory, we investigate the electronic and magnetic properties of an adatom (Na, Cu and Fe) on ABA- and ABC-stacked (Bernal and rhombohedral) trilayer graphenes. In particular, we study the influence of an applied gate voltage on magnetism, as it modifies the electronic states of the trilayer graphene (TLG) as well as changes the adatom spin states. Our study performed for a choice of three different adatoms (Na, Cu, and Fe) shows that the nature of adatom-graphene bonding evolves from ionic to covalent in moving from an alkali metal (Na) to a transition metal (Cu or Fe). Applying an external electric field (EEF) to TLG systems with different stacking orders results in the transition between high- and low-spin states in the latter case (Cu, Fe) and induces a little of magnetism in the former (Na) without magnetism in the absence of an external electric field. Our study would be useful for controlled adatom magnetism and (organic) spintronic applications in nanotechnology.

  12. Spin-glass behavior in YCo 10- xNi xSi 2 with high Ni content

    Science.gov (United States)

    Tang, H.; Qiao, G. W.; Liu, J. P.; Sellmyer, D. J.; de Boer, F. R.; Buschow, K. H. J.

    2001-02-01

    The magnetic properties and the structure of YCo 10- xNi xSi 2 alloys with high Ni content have been investigated by means of measurements of X-ray diffraction, dc magnetization and ac-susceptibility. The samples are basically of single phase (with x=6, 7, 8, 8.5, 9, 10) and adopt the ThMn 12 type structure. With x≤7.0, the samples show ferromagnetic behavior below the Curie temperatures. For compounds YCo 2Ni 8Si 2 and YCo 1.5Ni 8.5Si 2, the ac-susceptibility and dc zero-field cooling (ZFC) M( T) curve show a cusp with decreasing temperature, and the dc ZFC and field cooling (FC) M( T) curves in lower fields exhibit thermal irreversibility at low temperatures. The magnetization curves at temperatures below the cusp temperature on the ZFC branches do not saturate in the field range of H≤55 kOe. Furthermore, the hysteresis loops at temperatures below the cusp temperature exhibit no coercivity after ZFC. All these features suggest a spin-glass ordering of the compounds YCo 10- xNi xSi 2 with x equal to 8 and 8.5. The spin-glass behavior can be understood in terms of a competition between ferromagnetic interactions involving close Co-Co neighbors and antiferromagnetic interactions involving more remote Co-Co neighbors.

  13. Linear Classification of Dairy Cattle. Slide Script.

    Science.gov (United States)

    Sipiorski, James; Spike, Peter

    This slide script, part of a series of slide scripts designed for use in vocational agriculture classes, deals with principles of the linear classification of dairy cattle. Included in the guide are narrations for use with 63 slides, which illustrate the following areas that are considered in the linear classification system: stature, strength,…

  14. Approved Practices in Dairy Reproduction. Slide Script.

    Science.gov (United States)

    Roediger, Roger D.; Barr, Harry L.

    This slide script, part of a series of slide scripts designed for use in vocational agriculture classes, deals with approved practices in dairy reproduction. Included in the guide are narrations for use with 200 slides dealing with the following topics: the importance of good reproduction, the male and female roles in reproduction, selection of…

  15. Antiferromagnetic spin Seebeck effect.

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Stephen M.; Zhang, Wei; KC, Amit; Borisov, Pavel; Pearson, John E.; Jiang, J. Samuel; Lederman, David; Hoffmann, Axel; Bhattacharya, Anand

    2016-03-03

    We report on the observation of the spin Seebeck effect in antiferromagnetic MnF2. A device scale on-chip heater is deposited on a bilayer of MnF2 (110) (30nm)/Pt (4 nm) grown by molecular beam epitaxy on a MgF2(110) substrate. Using Pt as a spin detector layer, it is possible to measure the thermally generated spin current from MnF2 through the inverse spin Hall effect. The low temperature (2–80 K) and high magnetic field (up to 140 kOe) regime is explored. A clear spin-flop transition corresponding to the sudden rotation of antiferromagnetic spins out of the easy axis is observed in the spin Seebeck signal when large magnetic fields (>9T) are applied parallel to the easy axis of the MnF2 thin film. When the magnetic field is applied perpendicular to the easy axis, the spin-flop transition is absent, as expected.

  16. Antiferromagnetic Spin Seebeck Effect.

    Science.gov (United States)

    Wu, Stephen M; Zhang, Wei; Kc, Amit; Borisov, Pavel; Pearson, John E; Jiang, J Samuel; Lederman, David; Hoffmann, Axel; Bhattacharya, Anand

    2016-03-04

    We report on the observation of the spin Seebeck effect in antiferromagnetic MnF_{2}. A device scale on-chip heater is deposited on a bilayer of MnF_{2} (110) (30  nm)/Pt (4 nm) grown by molecular beam epitaxy on a MgF_{2} (110) substrate. Using Pt as a spin detector layer, it is possible to measure the thermally generated spin current from MnF_{2} through the inverse spin Hall effect. The low temperature (2-80 K) and high magnetic field (up to 140 kOe) regime is explored. A clear spin-flop transition corresponding to the sudden rotation of antiferromagnetic spins out of the easy axis is observed in the spin Seebeck signal when large magnetic fields (>9  T) are applied parallel to the easy axis of the MnF_{2} thin film. When the magnetic field is applied perpendicular to the easy axis, the spin-flop transition is absent, as expected.

  17. Spin Injection in Indium Arsenide

    Directory of Open Access Journals (Sweden)

    Mark eJohnson

    2015-08-01

    Full Text Available In a two dimensional electron system (2DES, coherent spin precession of a ballistic spin polarized current, controlled by the Rashba spin orbit interaction, is a remarkable phenomenon that’s been observed only recently. Datta and Das predicted this precession would manifest as an oscillation in the source-drain conductance of the channel in a spin-injected field effect transistor (Spin FET. The indium arsenide single quantum well materials system has proven to be ideal for experimental confirmation. The 2DES carriers have high mobility, low sheet resistance, and high spin orbit interaction. Techniques for electrical injection and detection of spin polarized carriers were developed over the last two decades. Adapting the proposed Spin FET to the Johnson-Silsbee nonlocal geometry was a key to the first experimental demonstration of gate voltage controlled coherent spin precession. More recently, a new technique measured the oscillation as a function of channel length. This article gives an overview of the experimental phenomenology of the spin injection technique. We then review details of the application of the technique to InAs single quantum well (SQW devices. The effective magnetic field associated with Rashba spin-orbit coupling is described, and a heuristic model of coherent spin precession is presented. The two successful empirical demonstrations of the Datta Das conductance oscillation are then described and discussed.

  18. Spin current

    CERN Document Server

    Valenzuela, Sergio O; Saitoh, Eiji; Kimura, Takashi

    2017-01-01

    Since the discovery of the giant magnetoresistance effect in magnetic multilayers in 1988, a new branch of physics and technology, called spin-electronics or spintronics, has emerged, where the flow of electrical charge as well as the flow of electron spin, the so-called “spin current,” are manipulated and controlled together. The physics of magnetism and the application of spin current have progressed in tandem with the nanofabrication technology of magnets and the engineering of interfaces and thin films. This book aims to provide an introduction and guide to the new physics and applications of spin current, with an emphasis on the interaction between spin and charge currents in magnetic nanostructures.

  19. A technigue exploitation about anti-slide tire polyploid on ice-snow road in winter

    Science.gov (United States)

    Xiaojie, Qi; Qiang, Wang; Zhao, Yang; Yunlong, Wang; Guotian, Wang; Degang, Lv

    2017-04-01

    Present studies focus on improving anti-slide property of tyes on ice-snow road by changing material modification of tyre tread and designing groove. However, the basic reason causing starting slide, long braking distance, turning slide slip and so on of tyres used in winter is that tyre tread materials are unitary and homogenous rubber composite which can’t coordinate driving demands of tyres in winter under muti-work condition, and can’t exert their best property when starting, braking and sliding slip. In order to improve comprehensive anti-slide property of tyres, this paper discusses about changing structure, shape and distribution proportion among haploid materials of tyre tread rubber. Polyploid bubber tyre tread technique based on artificial neural network which is in favor of starting, braking and anti-slide slip is optimized and combined. Friction feature and anti-slide mechanism on ice-snow road of polyploid rubber tyre tread are studied using testing technique of low-temperature cabin and computer simulation. A set high anti-slide theories and realizing method systems of polyploid rubber composite formed from basic theory, models and technique method are developped which will be applied into solving anti-slide problem of winter tyres, provide theory instruction for studies on high anti-slide winter tyres, and promote development of application and usage safety of winter tyres.

  20. Magnetism and the spin state in cubic perovskite CaCo O3 synthesized under high pressure

    Science.gov (United States)

    Xia, Hailiang; Dai, Jianhong; Xu, Yuanji; Yin, Yunyu; Wang, Xiao; Liu, Zhehong; Liu, Min; McGuire, Michael A.; Li, Xiang; Li, Zongyao; Jin, Changqing; Yang, Yifeng; Zhou, Jianshi; Long, Youwen

    2017-07-01

    Cubic SrCo O3 with an intermediate spin state can only be stabilized by high pressure and high temperature (HPHT) treatment. It is metallic and ferromagnetic with the highest Curie temperature of the transition-metal perovskites. The chemical substitution by Ca on Sr sites would normally lower crystal symmetry from cubic to orthorhombic as seen in the perovskite family of Ca M O3 (M =M4 + of transition metals, G e4 + , S n4 + , and Z r4 + ) at room temperature. This structural change narrows the bandwidth, so as to further enhance the Curie temperature as the crossover to the localized electronic state is approached. We report a successful synthesis of the perovskite CaCo O3 with a HPHT treatment. Surprisingly, CaCo O3 crystallizes in a simple cubic structure that remains stable down to 20 K, the lowest temperature in the structural study. The new perovskite has been thoroughly characterized by a suite of measurements including transport, magnetization, specific heat, thermal conductivity, and thermoelectric power. Metallic CaCo O3 undergoes two successive magnetic transitions at 86 K and 54 K as temperature decreases. The magnetization at 5 K is compatible with the intermediate spin state t4e1 of C o4 + at the octahedral site. The thermal expansion of the Co-O bond length indicates that the population of high spin state t3e2 increases for T >100 K . The shortest Co-O bond length in cubic CaCo O3 is responsible for delocalizing electrons in the π*-band and itinerant-electron ferromagnetism at T <54 K . A comprehensive comparison between SrCo O3 and CaCo O3 and the justification of their physical properties by first-principles calculation have also been made in this report. Partially filled π* and σ* bands would make CaCo O3 suitable to study the Hund's coupling effect in a metal.

  1. Spin multiplicities

    Energy Technology Data Exchange (ETDEWEB)

    Curtright, T.L., E-mail: curtright@miami.edu [Department of Physics, University of Miami, Coral Gables, FL 33124-8046 (United States); Van Kortryk, T.S., E-mail: vankortryk@gmail.com [Department of Physics, University of Miami, Coral Gables, FL 33124-8046 (United States); High Energy Physics Division, Argonne National Laboratory, Argonne, IL 60439-4815 (United States); Zachos, C.K., E-mail: zachos@anl.gov [Department of Physics, University of Miami, Coral Gables, FL 33124-8046 (United States); High Energy Physics Division, Argonne National Laboratory, Argonne, IL 60439-4815 (United States)

    2017-02-05

    The number of times spin s appears in the Kronecker product of n spin j representations is computed, and the large n asymptotic behavior of the result is obtained. Applications are briefly sketched. - Highlights: • We give a self-contained derivation of the spin multiplicities that occur in n-fold tensor products of spin-j representations. • We make use of group characters, properties of special functions, and asymptotic analysis of integrals. • We emphasize patterns that arise when comparing different values of j, and asymptotic behavior for large n. • Our methods and results should be useful for various statistical and quantum information theory calculations.

  2. Spinning Them Off: Entrepreneuring Practices in Corporate Spin-Offs

    Directory of Open Access Journals (Sweden)

    Katja Maria Hydle

    2016-01-01

    Full Text Available This paper focuses on the practices between parent and child firms in corporate spinoffs. We uncover the enacted aspects of knowledge, called knowing, through theories from seven cases of incumbent-backed spin-offs and find that the management of the parent firms are highly involved in the spin-offs. The practices associated with spinning off are solving problems, involving multidisciplinary expertise and entrepreneuring management at the parent firm. We contribute to the spin-off literature by discussing the knowledge required for successfully spinning off child firms and to practice theory by empirically uncovering the practical understanding involved in the origin and perpetuation of an organization.

  3. Development of high heat resistant polyphenols applied to the spin-on carbon hardmask

    Science.gov (United States)

    Takigawa, Tomoaki; Horiuchi, Junya; Uchiyama, Naoya; Okada, Kana; Shimizu, Yoko; Makinoshima, Takashi; Sato, Takashi; Echigo, Masatoshi

    2017-03-01

    In this paper, we report on new polyphenols synthesized by the condensation compounds of phenols and aldehydes. The phenols were 4,4'-biphenol, 2,6-dihydroxynaphthalene and 2,7-dihydroxynaphthalene. The aldehydes were 4- phenylbenzaldehyde and 4,4'-biphenyldicarbaldehyde. And we evaluated basic properties for the Spin-On Carbon Hardmask [1]. We recognized 4,4'-biphenol was showed good applicability to the best raw material of the phenols for polyphenol, and 2,6-dihydroxynaphthalene was showed good applicability to better raw material for polyphenol than 2,7-dihydroxynaphthalene. 4,4'-biphenyldicaraldehyde was better raw material of the aldehydes for polyphenols than 4- phenylbenzaldehyde, in solubility. As for heat resistance, 2,6-dihydroxynaphthalene was the best raw material of the phenols for polyphenols, 2,7-dihydroxynaphthalene was better raw material for polyphenols than 4,4'-biphenol. However, NF7177 synthesized by the condensation of 4,4'-biphenol and 4-phenylbenzaldehyde and NF7A78 synthesized by the condensation of 4,4'-biphenol and 4,4'-biphenyldicarbaldehyde seem to be crosslinking by heating, whence the heat resistance of the polyphenols using 4,4'-biphenol might be improved by optimizing heating condition. These materials are low molecular weight of less than 1000, so we expected having good planarization and gap filling.

  4. High resolution magic angle spinning 1H NMR of childhood brain and nervous system tumours

    Directory of Open Access Journals (Sweden)

    Davies Nigel P

    2009-02-01

    Full Text Available Abstract Background Brain and nervous system tumours are the most common solid cancers in children. Molecular characterisation of these tumours is important for providing novel biomarkers of disease and identifying molecular pathways which may provide putative targets for new therapies. 1H magic angle spinning NMR spectroscopy (1H HR-MAS is a powerful tool for determining metabolite profiles from small pieces of intact tissue and could potentially provide important molecular information. Methods Forty tissue samples from 29 children with glial and primitive neuro-ectodermal tumours were analysed using HR-MAS (600 MHz Varian gHX nanoprobe. Tumour spectra were fitted to a library of individual metabolite spectra to provide metabolite values. These values were then used in a two tailed t-test and multi-variate analysis employing a principal component analysis and a linear discriminant analysis. Classification accuracy was estimated using a leave-one-out analysis and B632+ bootstrapping. Results Glial tumours had significantly (two tailed t-test p Conclusion HR-MAS identified key differences in the metabolite profiles of childhood brain and nervous system improving the molecular characterisation of these tumours. Further investigation of the underlying molecular pathways is required to assess their potential as targets for new agents.

  5. Double longitudinal spin asymmetries in single hadron photoproduction at high p_T at COMPASS

    CERN Document Server

    Levillain, Maxime

    This thesis presents a new study aiming at constraining the gluon contribution {\\Delta G} to the 1/2 nucleon spin. The collinear pQCD theoretical framework, on which it is based, deals with asymmetries calculated from cross-sections for single inclusive hadron in the regime of quasi-real photoproduction {Q^2 1 GeV/c). These calculations are done up to Next-to-Leading order with a foreseen inclusion of Next-to-Leading logarithm threshold gluon resummation, only performed for the unpolarised cross-sections yet. This makes the asymmetries sensitive to the gluon polarisation not only through Photon Gluon Fusion {\\gamma* g} but also through resolved {\\gamma*}g processes such as qg or gg. The measurement of the asymmetries is performed for all the COMPASS data available from 2002 to 2011 with a polarised muon beam at 160-200 GeV scattered off a longitudinally polarised target of deuteron ( {_6LiD} for 2002-2006) or proton ({NH_3} for 2007 and 2011). The asymmetries are presented in bins of pT and of pseudorapidity...

  6. High-field magnetic phase transitions and spin excitations in magnetoelectric LiNiPO4

    DEFF Research Database (Denmark)

    Toft-Petersen, Rasmus; Jensen, Jens; Jensen, Thomas Bagger Stibius

    2011-01-01

    The magnetically ordered phases and spin dynamics of magnetoelectric LiNiPO4 have been studied in fields up to 17.3 T along the c axis. Using neutron diffraction, we show that a previously proposed linearly polarized incommensurate (IC) structure exists only for temperatures just below the Neel...... temperature T-N. The ordered IC structure at the lowest temperatures is shown instead to be an elliptically polarized canted spiral for fields larger than 12 T. The transition between the two IC phases is of second order and takes place about 2 K below T-N. For mu H-0 > 16 T and temperatures below 10 K......, the spiral structure is found to lock in to a period of five crystallographic unit cells along the b axis. Based on the neutron-diffraction data, combined with detailed magnetization measurements along all three crystallographic axes, we establish the magnetic phase diagrams for fields up to 17.3 T along c...

  7. High frequency out-of-plane oscillation with large cone angle in mag-flip spin torque oscillators for microwave assisted magnetic recording

    Science.gov (United States)

    Bosu, S.; Sepehri-Amin, H.; Sakuraba, Y.; Kasai, S.; Hayashi, M.; Hono, K.

    2017-04-01

    We investigated spin torque induced magnetization dynamics in the mag-flip spin torque oscillators (STOs) of diameters D from 29 to 96 nm comprising of an in-plane magnetized field generation layer (FGL) Fe67Co33 (7 nm) with high saturation magnetization, μ0Ms ˜ 2.3 T, and perpendicular FePt(10 nm)/Co2FeGa0.5Ge0.5(3 nm) highly spin polarized spin injection layers. Out-of-plane high frequency, f ˜ 21-26 GHz, spin torque induced oscillation with a large cone angle in FGL was observed under nearly perpendicular external magnetic field μ0Hext of 1.1 T for the pillar D of 29 and 42 nm. Our micromagnetic simulation results indicated that ac magnetic fields of about 0.15 to 0.2 T are obtainable from the STOs having the same stacking structure and size as the experiment, which is large enough for the applications to microwave assisted magnetic recording technology.

  8. Hypersonic sliding target tracking in near space

    Directory of Open Access Journals (Sweden)

    Xiang-yu Zhang

    2015-12-01

    Full Text Available To improve the tracking accuracy of hypersonic sliding target in near space, the influence of target hypersonic movement on radar detection and tracking is analyzed, and an IMM tracking algorithm is proposed based on radial velocity compensating and cancellation processing of high dynamic biases under the earth centered earth fixed (ECEF coordinate. Based on the analysis of effect of target hypersonic movement, a measurement model is constructed to reduce the filter divergence which is caused by the model mismatch. The high dynamic biases due to the target hypersonic movement are approximately compensated through radial velocity estimation to achieve the hypersonic target tracking at low systematic biases in near space. The high dynamic biases are further eliminated by the cancellation processing of different radars, in which the track association problem can be solved when the dynamic biases are low. An IMM algorithm based on constant acceleration (CA, constant turning (CT and Singer models is used to achieve the hypersonic sliding target tracking in near space. Simulation results show that the target tracking in near space can be achieved more effectively by using the proposed algorithm.

  9. The Microseismicity of Glacier Sliding

    Science.gov (United States)

    Walter, Fabian; Röösli, Claudia; Kissling, Edi

    2017-04-01

    Our understanding of glacier and ice sheet basal motion remains incomplete. The past decades have witnessed a shift away from initially proposed hard bed theories towards soft, till-laden beds, which deform and thus participate in basal motion. The theoretical treatment of deformable beds is subject to debate, yet our capability to predict ice sheet flow and ultimately sea level rise is contingent upon correct parameterization of basal motion (Ritz et al., 2015). Both hard and soft bed theories neglect frictional sliding across distinct basal fault planes and elastic deformation in response to sudden dislocation. Over recent years, this view has been repeatedly challenged as more and more studies report seismogenic faulting associated with basal sliding. For instance, large parts of the Whillans Ice Stream at Antarctica's Siple Coast move nearly exclusively during sudden sliding episodes (Wiens et al., 2008). This "stick-slip motion" is difficult to explain with traditional glacier sliding theories but more analogous to earthquake dislocation on tectonic faults. Although the Whillans Ice Stream motion may be an extreme example, there exists evidence for much smaller microseismic stick-slip events beneath the Greenland Ice Sheet and non-polar glaciers (Podolskiy and Walter, 2016). This raises the question how relevant and widespread the stick-slip phenomenon is and if it is necessary to include it into ice sheet models. Here we discuss recent seismic deployments, which focused on detection of stick-slip events beneath the Greenland Ice Sheet and European Alpine Glaciers. For all deployments, a considerable challenge lies in detection of stick-slip seismograms in the presence of a dominant background seismicity associated with surface crevassing. Nevertheless, automatic search algorithms and waveform characteristics provide important insights into temporal variation of stick-slip activity as well as information about fault plane geometry and co-seismic sliding

  10. Solution spinning of high-T{sub c} oxide superconductors: part VII. The effect of polyvinyl alcohol spinning medium on the sintering of YBa{sub 2}Cu{sub 3}O{sub x} superconducting filaments

    Energy Technology Data Exchange (ETDEWEB)

    Tomita, Hisayo [Suzuka Junior College, 1250 Shono, Suzuka, Mie 513 (Japan); Goto, Tomoko; Takahashi, Kiyohisa [Department of Material Science and Engineering, Nagoya Institute of Technology, Gokiso-cho, Showa-ku, Nagoya 466 (Japan)

    1996-05-01

    As basic research for the solution spinning of high-T{sub c} oxide superconductor, the effect of poly(vinyl alcohol) (PVA) spinning medium on the sintering of YBa{sub 2}Cu{sub 3}O{sub x} filament was examined. A precursor filament was produced by dry-spinning starting from a homogeneous aqueous PVA solution of Y, Ba and Cu acetates. The as-drawn filament was pyrolysed to remove volatile components and sintered to generate a superconducting phase. The degree of polymerization (DP) of PVA and the content of acetates in the precursor filament affected the J{sub c} of the sintered filament. Although most filaments exhibited high J{sub c} greater than 10{sup 3} A cm{sup -3} at 77 K and 0 T, superconductivity above 77 K was not observed for the filament spun from PVA solution of DP=2450 with [acetates]/[PVA]=2 and sintered at 900 and 920{sup 0}C for 15 min. The filament had a dense structure due to liquid phase sintering. The filament with high J{sub c} had a skin-core structure, and the highest J{sub c} of 4.3x10{sup 3} A cm{sup -2} at 77 K and 0 T was attained for the filament from DP=3500 with [acetates]/[PVA]=4. (author)

  11. A high-resolution fast spin-echo inversion-recovery sequence for preoperative localization of the internal globus pallidus.

    Science.gov (United States)

    Reich, C A; Hudgins, P A; Sheppard, S K; Starr, P A; Bakay, R A

    2000-05-01

    A fast spin-echo inversion-recovery (FSE-IR) sequence is described for its utility regarding surgical planning for patients with Parkinson's disease (PD) who are undergoing microelectrode-guided internal globus pallidus (GPi) ablation. Images from thirty-seven adult patients with PD were reviewed and visualization of the GPi, globus pallidus externa (GPe), and the intervening lamina was noted. High-resolution images were acquired from all patients despite the external hardware and the patients' movement disorder. In all cases, the conventional surgical trajectory, determined indirectly by a fixed measurement from the anteroposterior commissure line, was modified by the ability to visualize the GPi and optic tract directly. This sequence facilitated accurate stereotactic targeting.

  12. Study of the odd-${A}$, high-spin isomers in neutron-deficient trans-lead nuclei with ISOLTRAP

    CERN Multimedia

    Herfurth, F; Blaum, K; Beck, D; Kowalska, M; Schwarz, S; Stanja, J; Huyse, M L; Wienholtz, F

    We propose to measure the excitation energy of the $\\frac{13^{+}}{2}$ isomers in the neutron-deficient isotopes $^{193,195,197}$Po with the ISOLTRAP mass spectrometer. The assignment of the low- and high-spin isomers will be made by measuring the energy of the $\\alpha$- particles emitted in the decay of purified beams implanted in a windmill system. Using $\\alpha$-decay information, it is then also possible to determine the excitation energy of the similar isomers in the $\\alpha$-daughter nuclei $^{189,191,193}$Pb, $\\alpha$-parent nuclei $^{197,199,201}$Rn, and $\\alpha$-grand-parent nuclei $^{201,203,205}$Ra. The polonium beams are produced with a UC$_{\\textrm{x}}$ target and using the RILIS.

  13. High-spin states and a new band based on the isomeric state in {sup 152}Nd

    Energy Technology Data Exchange (ETDEWEB)

    Yeoh, E.Y.; Wang, J.G.; Ding, H.B.; Gu, L.; Xu, Q.; Xiao, Z.G. [Tsinghua University, Department of Physics, Beijing (China); Zhu, S.J. [Tsinghua University, Department of Physics, Beijing (China); Vanderbilt University, Department of Physics, Nashville, TN (United States); Hamilton, J.H.; Ramayya, A.V.; Hwang, J.K.; Liu, S.H.; Li, K. [Vanderbilt University, Department of Physics, Nashville, TN (United States); Yang, Y.C.; Sun, Y. [Shanghai Jiao Tong University, Department of Physcis, Shanghai (China); Luo, Y.X. [Vanderbilt University, Department of Physics, Nashville, TN (United States); Lawrence Berkeley National Laboratory, Berkeley, CA (United States); Rasmussen, J.O.; Lee, I.Y. [Lawrence Berkeley National Laboratory, Berkeley, CA (United States); Ma, W.C. [Mississippi State University, Department of Physics, Mississippi State, MS (United States)

    2010-08-15

    High-spin states of the neutron-rich {sup 152}Nd nucleus have been reinvestigated by measuring the prompt {gamma} -rays in the spontaneous fission of {sup 252}Cf. The ground-state band and a side negative-parity band have been updated. A new band based on the 2243.7keV isomeric state has been identified. The half-life for the isomeric state has been measured to be 63(7)ns. The projected shell model is employed to study the band structure of this nucleus. The results show that the calculated levels of the bands are in good agreement with the experimental ones, and the isomeric state and the negative-parity band are based on the proton {pi} 5/2{sup -}[532] x {pi}9/2{sup +}[404] and neutron {nu} 3/2{sup -}[521] x {nu}5/2{sup +}[642] two-quasiparticles configurations, respectively. (orig.)

  14. International school on high field NMR spectroscopy for solids and liquids

    Energy Technology Data Exchange (ETDEWEB)

    Marion, D.; Meier, B.; Keeler, J.; Berthault, P.; Vedrine, P.; Grandinetti, P.; Delsuc, M.A.; Spiess, H

    2006-07-01

    The aim of the school is to offer high-level pedagogical courses on a wide range of liquid- and solid-state NMR concepts and techniques: theory, instrumentation (magnets and probes), data acquisition, processing and analysis, measurement of dipolar and quadrupolar couplings, spin relaxation and hyper-polarization. This document gathers only the slides of most presentations.

  15. High-Resolution Two-Dimensional Optical Spectroscopy of Electron Spins

    Directory of Open Access Journals (Sweden)

    M. Salewski

    2017-08-01

    Full Text Available Multidimensional coherent optical spectroscopy is one of the most powerful tools for investigating complex quantum mechanical systems. While it was conceived decades ago in magnetic resonance spectroscopy using microwaves and radio waves, it has recently been extended into the visible and UV spectral range. However, resolving MHz energy splittings with ultrashort laser pulses still remains a challenge. Here, we analyze two-dimensional Fourier spectra for resonant optical excitation of resident electrons to localized trions or donor-bound excitons in semiconductor nanostructures subject to a transverse magnetic field. Particular attention is devoted to Raman coherence spectra, which allow one to accurately evaluate tiny splittings of the electron ground state and to determine the relaxation times in the electron spin ensemble. A stimulated steplike Raman process induced by a sequence of two laser pulses creates a coherent superposition of the ground-state doublet which can be retrieved only optically because of selective excitation of the same subensemble with a third pulse. This provides the unique opportunity to distinguish between different complexes that are closely spaced in energy in an ensemble. The related experimental demonstration is based on photon-echo measurements in an n-type CdTe/(Cd,MgTe quantum-well structure detected by a heterodyne technique. The difference in the sub-μeV range between the Zeeman splittings of donor-bound electrons and electrons localized at potential fluctuations can be resolved even though the homogeneous linewidth of the optical transitions is larger by 2 orders of magnitude.

  16. Mn7 species with an S = 29/2 ground state: high-frequency EPR studies of a species at the classical/quantum spin interface.

    Science.gov (United States)

    Wang, Zhenxing; van Tol, Johan; Taguchi, Taketo; Daniels, Matthew R; Christou, George; Dalal, Naresh S

    2011-11-09

    A high spin (S) compound has been synthesized whose properties straddle the interface between the classical and quantum mechanical spin descriptions. The cluster [Mn(7)O(4)(pdpm)(6)(N(3))(4)](ClO(4))(2) (Mn(7)) has an unprecedented core structure comprising an octahedral [Mn(III)(6)(μ(4)-O)(μ(3)-O)(3)(μ(3)-N(3))(4)](6+) unit with one of its faces capped by a Mn(II) ion. Magnetization and susceptibility studies indicate an S = (29/2) ground state, the maximum possible. Variable-temperature, high-frequency electron paramagnetic resonance (HF-EPR) spectra on powder and single-crystal samples of Mn(7) exhibit sharp spectral features characteristic of a quantum spin that are well resolved in a certain temperature range but which transform to a continuum of peaks characteristic of a classical spin in another; these features have been well reproduced by computer simulations. A fast Fourier transform analysis of the sharp spectral features and the low temperature EPR spectra suggests that more than one spin state are involved.

  17. Streamers sliding on a water surface

    Science.gov (United States)

    Akishev, Yuri Semenov; Karalnik, Vladimir; Medvedev, Mikhail; Petryakov, Alexander; Trushkin, Nikolay; Shafikov, Airat

    2017-06-01

    The features of an electrical interaction between surface streamers (thin current filaments) sliding on a liquid and liquid itself are still unknown in many details. This paper presents the experimental results on properties of the surface streamers sliding on water with different conductivity (distilled and tap water). The streamers were initiated with a sharpened thin metallic needle placed above the liquid and stressed with a periodical or pulsed high voltage. Two electrode systems were used and tested. The first of them provides in advance the existence of the longitudinal electric field above the water. The second one imitates the electrode geometry of a pin-to-plane dielectric barrier discharge in which the barrier is a thick layer of liquid. The electrical and optical characteristics of streamers were complemented with data on the spectroscopic measurements. It was revealed that surface streamers on water have no spatial memory. Contribution to the topical issue "The 15th International Symposium on High Pressure Low Temperature Plasma Chemistry (HAKONE XV)", edited by Nicolas Gherardi and Tomáš Hoder

  18. Spin Electronics

    Science.gov (United States)

    2003-08-01

    spin resonance of rare earth and transition metal impurities in chalcopyrite semiconductors. They also have worked in diluted magnetic...past, the ferromagnetic injector had been a ferromagnetic metal or alloy containing 3d transition elements with fractional spin polarization of the...polarized carriers. There have been numerous attempts to inject transition metals or their alloys into semiconductors, either directly (Johnson and

  19. Exotic spin phases in the one-dimensional spin-1/2 quantum magnet LiCuSbO{sub 4} as seen by high-field NMR and ESR spectroscopies

    Energy Technology Data Exchange (ETDEWEB)

    Iakovleva, Margarita [IFW Dresden, Dresden (Germany); TU Dresden, Dresden (Germany); Zavoisky Physical Technical Institute, Kazan (Russian Federation); Grafe, Hans-Joachim; Kataev, Vladislav; Alfonsov, Alexey; Sturza, Mihai I.; Wurmehl, Sabine [IFW Dresden, Dresden (Germany); Vavilova, Evgeniia [Zavoisky Physical Technical Institute, Kazan (Russian Federation); Nojiri, Hiroyuki [Institute of Materials Research, Sendai (Japan); Buechner, Bernd [IFW Dresden, Dresden (Germany); TU Dresden, Dresden (Germany)

    2016-07-01

    We will present our recent results of high-field NMR and sub-THz ESR studies of the quantum magnet LiCuSbO{sub 4} (LCSO) that presents an excellent model system of a one-dimensional spin-1/2 quantum magnet with frustrated exchange interactions. Such networks are predicted to exhibit a plethora of novel ground states beyond classical ferro- or antiferromagnetic phases. In LCSO the absence of a long-range magnetic order down to sub-Kelvin temperatures is suggestive of the realization of a quantum spin liquid state. Our NMR and ESR measurements in strong magnetic fields up to 16 Tesla reveal clear indications for the occurrence of an exotic field-induced hidden phase which we will discuss in terms of multipolar physics.

  20. Spin glasses

    CERN Document Server

    Bovier, Anton

    2007-01-01

    Spin glass theory is going through a stunning period of progress while finding exciting new applications in areas beyond theoretical physics, in particular in combinatorics and computer science. This collection of state-of-the-art review papers written by leading experts in the field covers the topic from a wide variety of angles. The topics covered are mean field spin glasses, including a pedagogical account of Talagrand's proof of the Parisi solution, short range spin glasses, emphasizing the open problem of the relevance of the mean-field theory for lattice models, and the dynamics of spin glasses, in particular the problem of ageing in mean field models. The book will serve as a concise introduction to the state of the art of spin glass theory, usefull to both graduate students and young researchers, as well as to anyone curious to know what is going on in this exciting area of mathematical physics.

  1. Spin-inversion in nanoscale graphene sheets with a Rashba spin-orbit barrier

    Directory of Open Access Journals (Sweden)

    Somaieh Ahmadi

    2012-03-01

    Full Text Available Spin-inversion properties of an electron in nanoscale graphene sheets with a Rashba spin-orbit barrier is studied using transfer matrix method. It is found that for proper values of Rashba spin-orbit strength, perfect spin-inversion can occur in a wide range of electron incident angle near the normal incident. In this case, the graphene sheet with Rashba spin-orbit barrier can be considered as an electron spin-inverter. The efficiency of spin-inverter can increase up to a very high value by increasing the length of Rashba spin-orbit barrier. The effect of intrinsic spin-orbit interaction on electron spin inversion is then studied. It is shown that the efficiency of spin-inverter decreases slightly in the presence of intrinsic spin-orbit interaction. The present study can be used to design graphene-based spintronic devices.

  2. Effects of Exposure to Physique Slides on the Emotional Responses of Men and Women.

    Science.gov (United States)

    Hausenblas, Heather A.; Janelle, Christopher M.; Gardner, Rebecca Ellis; Hagan, Amy L.

    2002-01-01

    Examined high and low body dissatisfied (BD) men's and women's in-task emotional responses to acute exposure to sex-specific physique slides of the aesthetic ideal and of themselves. Participating college students reported their immediate in-task emotional responses to viewing the slides. Men and women, as well as high and low BD groups, reported…

  3. Evidence for Fast Electron Transfer between the High-Spin Haems in Cytochrome bd-I from Escherichia coli.

    Directory of Open Access Journals (Sweden)

    Sergey A Siletsky

    Full Text Available Cytochrome bd-I is one of the three proton motive force-generating quinol oxidases in the O2-dependent respiratory chain of Escherichia coli. It contains one low-spin haem (b558 and the two high-spin haems (b595 and d as the redox-active cofactors. In order to examine the flash-induced intraprotein reverse electron transfer (the so-called ''electron backflow'', CO was photolyzed from the ferrous haem d in one-electron reduced (b5583+b5953+d2+-CO cytochrome bd-I, and the fully reduced (b5582+b5952+d2+-CO oxidase as a control. In contrast to the fully reduced cytochrome bd-I, the transient spectrum of one-electron reduced oxidase at a delay time of 1.5 μs is clearly different from that at a delay time of 200 ns. The difference between the two spectra can be modeled as the electron transfer from haem d to haem b595 in 3-4% of the cytochrome bd-I population. Thus, the interhaem electron backflow reaction induced by photodissociation of CO from haem d in one-electron reduced cytochrome bd-I comprises two kinetically different phases: the previously unnoticed fast electron transfer from haem d to haem b595 within 0.2-1.5 μs and the slower well-defined electron equilibration with τ ~16 μs. The major new finding of this work is the lack of electron transfer at 200 ns.

  4. Nuclear inelastic scattering of 1D polymeric Fe(II) complexes of 1,2,4-aminotriazole in their high-spin and low-spin state

    Energy Technology Data Exchange (ETDEWEB)

    Wolny, Juliusz A., E-mail: wolny@physik.uni-kl.de; Rackwitz, Sergej [University of Kaiserslautern, Department of Physics (Germany); Achterhold, Klaus [Technische Universitaet Muenchen, Department of Physics (Germany); Muffler, Kai; Schuenemann, Volker [University of Kaiserslautern, Department of Physics (Germany)

    2012-03-15

    The vibrational properties of Fe(II) 1D spin crossover polymers have been characterized by nuclear inelastic scattering (NIS). The complexes under study were the tosylate and perchlorate salts of ([Fe(4-amino-1,2,4-triazole){sub 3}] <{sup +2}){sub n} complexes. The complexes have LS (S = 0) marker bands in the range of 300-500 cm{sup - 1}, while the marker bands corresponding to the HS (S = 2) state are detected between 200 cm{sup - 1} and 300 cm{sup - 1}, in line with the decreasing Fe-N bond strengths during the transition from LS to HS. Accompanying DFT calculations using the functional B3LYP and the basis set CEP-31G confirm these assignments.

  5. Applications of sliding mode control

    CERN Document Server

    Ghommam, Jawhar; Zhu, Quanmin

    2017-01-01

    This book presents essential studies and applications in the context of sliding mode control, highlighting the latest findings from interdisciplinary theoretical studies, ranging from computational algorithm development to representative applications. Readers will learn how to easily tailor the techniques to accommodate their ad hoc applications. To make the content as accessible as possible, the book employs a clear route in each paper, moving from background to motivation, to quantitative development (equations), and lastly to case studies/illustrations/tutorials (simulations, experiences, curves, tables, etc.). Though primarily intended for graduate students, professors and researchers from related fields, the book will also benefit engineers and scientists from industry. .

  6. Using computerized workflow simulations to assess the feasibility of whole slide imaging full adoption in a high-volume histology laboratory

    National Research Council Canada - National Science Library

    McClintock, David S; Lee, Roy E; Gilbertson, John R

    2012-01-01

    .... While WSI devices have become increasingly capable since their inception, there has been little consideration of how WSI will be implemented and subsequently affect the workflow of high volume histology laboratories...

  7. Ultra-high mobility transparent organic thin film transistors grown by an off-centre spin-coating method

    Science.gov (United States)

    Yuan, Yongbo; Giri, Gaurav; Ayzner, Alexander L.; Zoombelt, Arjan P.; Mannsfeld, Stefan C. B.; Chen, Jihua; Nordlund, Dennis; Toney, Michael F.; Huang, Jinsong; Bao, Zhenan

    2014-01-01

    Organic semiconductors with higher carrier mobility and better transparency have been actively pursued for numerous applications, such as flat-panel display backplane and sensor arrays. The carrier mobility is an important figure of merit and is sensitively influenced by the crystallinity and the molecular arrangement in a crystal lattice. Here we describe the growth of a highly aligned meta-stable structure of 2,7-dioctyl[1]benzothieno[3,2-b][1]benzothiophene (C8-BTBT) from a blended solution of C8-BTBT and polystyrene by using a novel off-centre spin-coating method. Combined with a vertical phase separation of the blend, the highly aligned, meta-stable C8-BTBT films provide a significantly increased thin film transistor hole mobility up to 43 cm2 Vs-1 (25 cm2 Vs-1 on average), which is the highest value reported to date for all organic molecules. The resulting transistors show high transparency of >90% over the visible spectrum, indicating their potential for transparent, high-performance organic electronics.

  8. Rolling Motion of a Ball Spinning about a Near-Vertical Axis

    Science.gov (United States)

    Cross, Rod

    2012-01-01

    A ball that is projected forward without spin on a horizontal surface will slide for a short distance before it starts rolling. Sliding friction acts to decrease the translation speed v and it acts to increase the rotation speed [omega]. When v = R[omega], where R is the ball radius, the ball will start rolling and the friction force drops almost…

  9. Designing for Damage: Robust Flight Control Design using Sliding Mode Techniques

    Science.gov (United States)

    Vetter, T. K.; Wells, S. R.; Hess, Ronald A.; Bacon, Barton (Technical Monitor); Davidson, John (Technical Monitor)

    2002-01-01

    A brief review of sliding model control is undertaken, with particular emphasis upon the effects of neglected parasitic dynamics. Sliding model control design is interpreted in the frequency domain. The inclusion of asymptotic observers and control 'hedging' is shown to reduce the effects of neglected parasitic dynamics. An investigation into the application of observer-based sliding mode control to the robust longitudinal control of a highly unstable is described. The sliding mode controller is shown to exhibit stability and performance robustness superior to that of a classical loop-shaped design when significant changes in vehicle and actuator dynamics are employed to model airframe damage.

  10. High-spin states and lifetimes in 33S and shell-model interpretation in the s d -f p space

    Science.gov (United States)

    Aydin, S.; Ionescu-Bujor, M.; Gavrilov, G. Tz.; Dimitrov, B. I.; Lenzi, S. M.; Recchia, F.; Tonev, D.; Bouhelal, M.; Kavillioglu, F.; Pavlov, P.; Bazzacco, D.; Bizzeti, P. G.; Bizzeti-Sona, A. M.; de Angelis, G.; Deloncle, I.; Farnea, E.; Gadea, A.; Gottardo, A.; Goutev, N.; Haas, F.; Huyuk, T.; Laftchiev, H.; Lunardi, S.; Marinov, Tz. K.; Mengoni, D.; Menegazzo, R.; Michelagnoli, C.; Napoli, D. R.; Petkov, P.; Sahin, E.; Singh, P. P.; Stefanova, E. A.; Ur, C. A.; Valiente-Dobón, J. J.; Yavahchova, M. S.

    2017-08-01

    The structure of the 33S nucleus was investigated in the 24Mg(14N,α p ) fusion-evaporation reaction using a 40-MeV 14N beam. The level scheme was extended up to an excitation energy of 11.7 MeV and spin 19 /2+ . Lifetimes of the intermediate- and high-spin states have been investigated by the Doppler shift attenuation method. Data were compared with different shell-model calculations where effective interactions involving two main shells, the sd and the fp, are used.

  11. Model for the high-temperature oxygen-ordering thermodynamics in YBa2Cu3O6+x - inclusion of electron spin and charge degrees of freedom

    DEFF Research Database (Denmark)

    Schleger, P.; Hardy, W.N.; Casalta, H.

    1994-01-01

    A lattice-gas model for the high temperature oxygen-ordering thermodynamics in YBa2Cu3O6+x is presented, which assumes constant effective pair interactions between oxygen atoms and includes in a simple fashion the effect of the electron spin and charge degrees of freedom. This is done using...... a commonly utilized picture relating the creation of mobile electron holes and unpaired spins to the insertion of oxygen into the basal plane. The model is solved using the nearest-neighbor square approximation of the cluster-variation method. In addition, preliminary Monte Carlo results using next...

  12. A study of spin-lattice relaxation rates of glucose, fructose, sucrose and cherries using high-T c SQUID-based NMR in ultralow magnetic fields

    Science.gov (United States)

    Liao, Shu-Hsien; Wu, Pei-Che

    2017-08-01

    We study the concentration dependence of spin-lattice relaxation rates, T 1 -1, of glucose, fructose, sucrose and cherries by using high-T c SQUID-based NMR at magnetic fields of ˜97 μT. The detected NMR signal, Sy (T Bp), is fitted to [1 - exp(-T Bp/T 1)] to derive T 1 -1, where Sy (T Bp) is the strength of the NMR signal, T Bp is the duration of pre-polarization and T 1 -1 is the spin-lattice relaxation rate. It was found that T 1 -1 increases as the sugar concentrations increase. The increased T 1 -1 is due to the presence of more molecules in the surroundings, which increases the spin-lattice interaction and in turn enhances T 1 -1. The T 1 -1 versus degrees Brix curve provides a basis for determining unknown Brix values for cherries as well as other fruits.

  13. High-spin configuration of Mn in Bi{sub 2}Se{sub 3} three-dimensional topological insulator

    Energy Technology Data Exchange (ETDEWEB)

    Wolos, Agnieszka, E-mail: agnieszka.wolos@fuw.edu.pl [Institute of Physics, Polish Academy of Sciences, Al. Lotnikow 32/46, 02-668 Warsaw (Poland); Faculty of Physics, University of Warsaw, ul. Pasteura 5, 02-093 Warsaw (Poland); Drabinska, Aneta [Faculty of Physics, University of Warsaw, ul. Pasteura 5, 02-093 Warsaw (Poland); Borysiuk, Jolanta [Institute of Physics, Polish Academy of Sciences, Al. Lotnikow 32/46, 02-668 Warsaw (Poland); Faculty of Physics, University of Warsaw, ul. Pasteura 5, 02-093 Warsaw (Poland); Sobczak, Kamil [Institute of Physics, Polish Academy of Sciences, Al. Lotnikow 32/46, 02-668 Warsaw (Poland); Kaminska, Maria [Faculty of Physics, University of Warsaw, ul. Pasteura 5, 02-093 Warsaw (Poland); Hruban, Andrzej [Institute of Physics, Polish Academy of Sciences, Al. Lotnikow 32/46, 02-668 Warsaw (Poland); Institute of Electronic Materials Technology, ul. Wolczynska 133, 01-919 Warsaw (Poland); Strzelecka, Stanislawa G.; Materna, Andrzej; Piersa, Miroslaw; Romaniec, Magdalena; Diduszko, Ryszard [Institute of Electronic Materials Technology, ul. Wolczynska 133, 01-919 Warsaw (Poland)

    2016-12-01

    Electron paramagnetic resonance was used to investigate Mn impurity in Bi{sub 2}Se{sub 3} topological insulator grown by the vertical Bridgman method. Mn in high-spin S=5/2, Mn{sup 2+}, configuration was detected regardless of the conductivity type of the host material. This means that Mn{sup 2+}(d{sup 5}) energy level is located within the valence band, and Mn{sup 1+}(d{sup 6}) energy level is outside the energy gap of Bi{sub 2}Se{sub 3}. The electron paramagnetic resonance spectrum of Mn{sup 2+} in Bi{sub 2}Se{sub 3} is characterized by the isotropic g-factor |g|=1.91 and large axial parameter D=−4.20 GHz h. This corresponds to the zero-field splitting of the Kramers doublets equal to 8.4 GHz h and 16.8 GHz h, respectively, which is comparable to the Zeeman splitting for the X-band. Mn in Bi{sub 2}Se{sub 3} acts as an acceptor, effectively reducing native-high electron concentration, compensating selenium vacancies, and resulting in p-type conductivity. However, Mn-doping simultaneously favors formation of native donor defects, most probably selenium vacancies. For high Mn-doping it may lead to the resultant n-type conductivity related with strong non-stoichiometry and degradation of the crystal structure - switching from Bi{sub 2}Se{sub 3} to BiSe phase. - Highlights: • We studied electron paramagnetic resonance in Bi{sub 2}Se{sub 3}:Mn. • We found Mn in high-spin Mn{sup 2+} configuration in both n-type and p-type samples. • The g-factor for Mn{sup 2+} equals to 1.91 and axial parameter D=−4.20 GHz h. • Mn acts as an acceptor. • Mn substitution affects formation of native donors.

  14. Influence of pairing on the ({ital p},{ital t}) transition strength between high-spin {ital K} isomers of Hf isotopes

    Energy Technology Data Exchange (ETDEWEB)

    Kuzmenko, N.K. [V. G. Khlopin Radium Institute, 2nd Murinsky Prosp. 28, St. Petersburg 194021 (Russian Federation); Mikhajlov, V.M. [Institute of Physics, St. Petersburg State University, St. Petersburg 19804 (Russian Federation)

    1995-05-01

    The influence of pairing on the probability of the two-nucleon-transfer transition between high-spin {ital K} isomers of Hf isotopes is discussed. Calculations of energies and cross sections are performed by using the particle number projection (FBCS method). In contrast with BCS, the FBCS method predicts that the pairing in many-quasiparticles states does not disappear.

  15. Phenomena of spin rotation and oscillation of particles (atoms, molecules) containing in a trap blowing on by wind of high energy particles in storage ring

    OpenAIRE

    Baryshevsky, Vladimir

    2013-01-01

    Spin rotation and oscillation phenomena of particles captured in a gas target through which beam of high energy particles passes is discussed. Such experiment arrangement make it realizable for storage ring and allows to study zero-angle scattering amplitude at highest possible energies.

  16. Exploring helical folding of oligoureas during chain elongation by high-resolution magic-angle-spinning (HRMAS) NMR spectroscopy.

    Science.gov (United States)

    Violette, Aude; Lancelot, Nathalie; Poschalko, Alexander; Piotto, Martial; Briand, Jean-Paul; Raya, Jesus; Elbayed, Karim; Bianco, Alberto; Guichard, Gilles

    2008-01-01

    The development of novel folding oligomers (foldamers) for biological and biomedical applications requires both precise structural information and appropriate methods to detect folding propensity. However, the synthesis and the systematic conformational investigation of large arrays of oligomers to determine the influence of factors, such as chain length, side chains, and surrounding environment, on secondary structure can be quite tedious. Herein, we show for 2.5-helical N,N'-linked oligoureas (gamma-peptide lineage) that the whole process of foldamer characterization can be accelerated by using high-resolution magic-angle-spinning (HRMAS) NMR spectroscopy. This was achieved by monitoring a simple descriptor of conformational homogeneity (e.g., chemical shift difference between diastereotopic main chain CH2 protons) at different stages of oligourea chain growth on a solid support. HRMAS NMR experiments were conducted on two sets of oligoureas, ranging from dimer to hexamer, immobilized on DEUSS, a perdeuterated poly(oxyethylene)-based solid support swollen in solvents of low to high polarity. One evident advantage of the method is that only minute amount of material is required. In addition, the resonance of the deuterated resin is almost negligeable. On-bead NOESY spectra of high quality and with resolution comparable to that of liquid samples were obtained for longer oligomers, thus allowing detailed structural characterization.

  17. Testing of newly developed functional surfaces under pure sliding conditions

    DEFF Research Database (Denmark)

    Godi, Alessandro; Mohaghegh, Kamran; Grønbæk, J.

    2013-01-01

    the surfaces in an industrial context. In this paper, a number of experimental tests were performed using a novel test rig, called axial sliding test, simulating the contact of surfaces under pure sliding conditions. The aim of the experiments is to evaluate the frictional behavior of a new typology...... of textured surfaces, the so-called multifunctional surfaces, characterized by a plateau area able to bear loads and a deterministic pattern of lubricant pockets. Six surface typologies, namely three multifunctional and three machined using classical processes, were chosen to slide against a mirror....... The results comparison showed clearly how employing multifunctional surfaces can reduce friction forces up to 50 % at high normal loads compared to regularly ground or turned surfaces. Friction coefficients approximately equal to 0.12 were found for classically machined surfaces, whereas the values were 0...

  18. Spin Physics at COMPASS

    CERN Document Server

    Schill, C

    2012-01-01

    The COMPASS experiment is a fixed target experiment at the CERN SPS using muon and hadron beams for the investigation of the spin structure of the nucleon and hadron spectroscopy. The main objective of the muon physics program is the study of the spin of the nucleon in terms of its constituents, quarks and gluons. COMPASS has accumulated data during 6 years scattering polarized muons off a longitudinally or a transversely polarized deuteron (6LiD) or proton (NH3) target. Results for the gluon polarization are obtained from longitudinal double spin cross section asymmetries using two different channels, open charm production and high transverse momentum hadron pairs, both proceeding through the photon-gluon fusion process. Also, the longitudinal spin structure functions of the proton and the deuteron were measured in parallel as well as the helicity distributions for the three lightest quark flavors. With a transversely polarized target, results were obtained with proton and deuteron targets for the Collins an...

  19. Cascade Control of Magnetic Levitation with Sliding Modes

    Directory of Open Access Journals (Sweden)

    Eroğlu Yakup

    2016-01-01

    Full Text Available The effectiveness and applicability of magnetic levitation systems need precise feedback control designs. A cascade control approach consisting of sliding mode control plus sliding mode control (SMC plus SMC is designed to solve position control problem and to provide a high control performance and robustness to the magnetic levitation plant. It is shown that the SMC plus SMC cascade controller is able to eliminate the effects of the inductance related uncertainties of the electromagnetic coil of the plant and achieve a robust and precise position control. Experimental and numerical results are provided to validate the effectiveness and feasibility of the method.

  20. Mixed Lubrication Solution of Dynamically Loaded Radial Slide Bearings

    Directory of Open Access Journals (Sweden)

    P. Novotny

    2017-03-01

    Full Text Available A solution of radial slide bearing dynamics and tribology incorporating the influences of real surface roughness contacts or the influence of surface roughness on bearing lubrication is presented in this paper. Finite difference method for Reynolds equation discretization, finite element method for calculation of elastic deformations, Gauss-Seidel’s method for iterative solution of discretized equations or Newmark’s algorithm are the methods employed in the proposed solution approach. The coupled structural-fluid solver considering mixed lubrication conditions of the radial bearings is the result. The proposed algorithms are presented for highly loaded radial slide bearing of internal combustion engine.

  1. Speed Control of Switched Reluctance Motor Using Fuzzy Sliding Mode

    Directory of Open Access Journals (Sweden)

    TAHOUR, A.

    2008-04-01

    Full Text Available In this paper, a fuzzy logic controller (FLC is designed, based on the similarity between the FLC and the sliding mode control (SMC, for a class of nonlinear system to tackle the nonlinear control problems with modelling uncertainties, plant parameters variations and external disturbances. The proposed scheme gives fast dynamic response with no overshoot and zero steady-state error. To show the validity and the effectiveness of the control method, simulations are performed for the speed control of a switched reluctance motor. The simulation results show that the controller designed is more effective than the conventional sliding mode controller in enhancing the robustness of control systems with high accuracy.

  2. TOPICAL REVIEW: Spin current, spin accumulation and spin Hall effect

    Directory of Open Access Journals (Sweden)

    Saburo Takahashi and Sadamichi Maekawa

    2008-01-01

    Full Text Available Nonlocal spin transport in nanostructured devices with ferromagnetic injector (F1 and detector (F2 electrodes connected to a normal conductor (N is studied. We reveal how the spin transport depends on interface resistance, electrode resistance, spin polarization and spin diffusion length, and obtain the conditions for efficient spin injection, spin accumulation and spin current in the device. It is demonstrated that the spin Hall effect is caused by spin–orbit scattering in nonmagnetic conductors and gives rise to the conversion between spin and charge currents in a nonlocal device. A method of evaluating spin–orbit coupling in nonmagnetic metals is proposed.

  3. Spin electronics

    CERN Document Server

    Buhrman, Robert; Daughton, James; Molnár, Stephan; Roukes, Michael

    2004-01-01

    This report is a comparative review of spin electronics ("spintronics") research and development activities in the United States, Japan, and Western Europe conducted by a panel of leading U.S. experts in the field. It covers materials, fabrication and characterization of magnetic nanostructures, magnetism and spin control in magnetic nanostructures, magneto-optical properties of semiconductors, and magnetoelectronics and devices. The panel's conclusions are based on a literature review and a series of site visits to leading spin electronics research centers in Japan and Western Europe. The panel found that Japan is clearly the world leader in new material synthesis and characterization; it is also a leader in magneto-optical properties of semiconductor devices. Europe is strong in theory pertaining to spin electronics, including injection device structures such as tunneling devices, and band structure predictions of materials properties, and in development of magnetic semiconductors and semiconductor heterost...

  4. Shifting gears higher - digital slides in graduate education - 4 years experience at Semmelweis University

    Directory of Open Access Journals (Sweden)

    Molnár Béla

    2010-11-01

    Full Text Available Abstract Background The spreading of whole slide imaging or digital slide systems in pathology as an innovative technique seems to be unstoppable. Successful introduction of digital slides in education has played a crucial role to reach this level of acceptance. Practically speaking there is no university institute where digital materials are not built into pathology education. At the 1st. Department of Pathology and Experimental Cancer Research, Semmelweis University optical microscopes have been replaced and for four years only digital slides have been used in education. The aim of this paper is to summarize our experiences gathered with the installation of a fully digitized histology lab for graduate education. Methods We have installed a digital histology lab with 40 PCs, two slide servers - one for internal use and one with external internet access. We have digitized hundreds of slides and after 4 years we use a set of 126 slides during the pathology course. A Student satisfaction questionnaire and a Tutor satisfaction questionnaire have been designed, both to be completed voluntarily to have feed back from the users. The page load statistics of the external slide server were evaluated. Results The digital histology lab served ~900 students and ~1600 hours of histology practice. The questionnaires revealed high satisfaction with digital slides. The results also emphasize the importance of the tutors' attitude towards digital microscopy as a factor influencing the students' satisfaction. The constantly growing number of page downloads from the external server confirms this satisfaction and the acceptance of digital slides. Conclusions We are confident, and have showed as well, that digital slides have got numerous advantages over optical slides and are more suitable in education.

  5. Shifting gears higher--digital slides in graduate education--4 years experience at Semmelweis University.

    Science.gov (United States)

    Fónyad, László; Gerely, László; Cserneky, Mária; Molnár, Béla; Matolcsy, András

    2010-11-22

    The spreading of whole slide imaging or digital slide systems in pathology as an innovative technique seems to be unstoppable. Successful introduction of digital slides in education has played a crucial role to reach this level of acceptance. Practically speaking there is no university institute where digital materials are not built into pathology education. At the 1st. Department of Pathology and Experimental Cancer Research, Semmelweis University optical microscopes have been replaced and for four years only digital slides have been used in education. The aim of this paper is to summarize our experiences gathered with the installation of a fully digitized histology lab for graduate education. We have installed a digital histology lab with 40 PCs, two slide servers - one for internal use and one with external internet access. We have digitized hundreds of slides and after 4 years we use a set of 126 slides during the pathology course. A Student satisfaction questionnaire and a Tutor satisfaction questionnaire have been designed, both to be completed voluntarily to have feed back from the users. The page load statistics of the external slide server were evaluated. The digital histology lab served ~900 students and ~1600 hours of histology practice. The questionnaires revealed high satisfaction with digital slides. The results also emphasize the importance of the tutors' attitude towards digital microscopy as a factor influencing the students' satisfaction. The constantly growing number of page downloads from the external server confirms this satisfaction and the acceptance of digital slides. We are confident, and have showed as well, that digital slides have got numerous advantages over optical slides and are more suitable in education.

  6. High-performance spinning device for DVD-based micromechanical signal transduction

    DEFF Research Database (Denmark)

    Hwu, En-Te; Chen, Ching-Hsiu; Bosco, Filippo

    2013-01-01

    mechanism, this device can simultaneously measure surface topography, mechanical deflections and resonance frequencies of several microfabricated beams at a high speed. In biochemical sensing applications, the OPU can measure bending changes of functionalized microcantilevers, providing a statistically...

  7. High-intensity polarized H- ion source for the RHIC SPIN physics

    Science.gov (United States)

    Zelenski, A.; Atoian, G.; Raparia, D.; Ritter, J.; Kolmogorov, A.; Davydenko, V.

    2017-08-01

    A novel polarization technique had been successfully implemented for the RHIC polarized H- ion source upgrade to higher intensity and polarization. In this technique a proton beam inside the high magnetic field solenoid is produced by ionization of the atomic hydrogen beam (from external source) in the He-gas ionizer cell. Further proton polarization is produced in the process of polarized electron capture from the optically-pumped Rb vapour. The use of high-brightness primary beam and large cross-sections of charge-exchange cross-sections resulted in production of high intensity H- ion beam of 85% polarization. High beam brightness and polarization resulted in 75% polarization at 23 GeV out of AGS and 60-65% beam polarization at 100-250 GeV colliding beams in RHIC. The status of un-polarized magnetron type (Cs-vapour loaded) BNL source is also discussed.

  8. Reading virtual slide using web viewers: results of subjective experience with three different solutions.

    Science.gov (United States)

    Rojo, Marcial García; Gallardo, Antonio J; González, Lucía; Peces, Carlos; Murillo, Cristina; González, Jesús; Sacristán, Jose

    2008-07-15

    Virtual slides are viewed using interactive software that enables the user to simulate the behaviour of a conventional optical microscope, like adjusting magnifications and navigating to any portion of the image. Nowadays, information about the performance and features of web-based solutions for reading slides in real environments is still scarce. The objective of this study is analyzing the subjective experience of pathologists with virtual slides, comparing the time needed to read slides using different web viewers and different network connections. Eight slides were randomly selected (4 biopsies and 2 cytologies) from Hospital General de Ciudad Real (HGCR) archives. Three different virtual slide web-viewing solutions were analyzed: Aperio web server, Olympus NetImage Server, and Aurora mScope. Five pathologists studied to time needed to access images of each virtual slide, selecting a panoramic view, 10 low magnification fields, and 20 high magnification fields. Aperio viewer is very efficient in overview images. Aurora viewer is especially efficient in lower magnifications (10x). For larger magnifications (20x and 40x) no significant differences were found between different vendors. Olympus was found to be the most user-friendly interface. When comparing Internet with intranet connections, despite being slower, users also felt comfortable using virtual slides through Internet connection. Available web solutions for virtual slides have different advantages, mainly in functionalities and optimization for different magnifications. Pathologists should select the solutions adapted to their needs.

  9. Metabolomics approach to thyroid nodules: a high-resolution magic-angle spinning nuclear magnetic resonance-based study.

    Science.gov (United States)

    Miccoli, Paolo; Torregrossa, Liborio; Shintu, Laetitia; Magalhaes, Alviclér; Chandran, JimaNambiath; Tintaru, Aura; Ugolini, Clara; Minuto, Michele N; Miccoli, Mario; Basolo, Fulvio; Caldarelli, Stefano

    2012-12-01

    Proton magnetic resonance spectroscopy of operative specimens has been reported to successfully differentiate normal tissue from malignant thyroid tissue. We used a new high-resolution magnetic resonance spectroscopy technique for the differentiation of benign and malignant thyroid neoplasms. Histological specimens from 72 patients undergoing a total thyroidectomy were processed into a 4-mm ZrO(2) high-resolution magic angle spinning (HRMAS) rotor with 5 μL of D(2)O. A Bruker Avance spectrometer operating at 400 MHz for the (1)H frequency and equipped with a (1)H/(13)C/(31)P HRMAS probe was used. Normal and neoplastic thyroid tissues could be discriminated from each other by different relative concentrations of several amino acids and lipids, as well as benign and malignant neoplasms, that differed in terms of a greater lactate and taurine and a lesser lipid choline, phosphocholine, myo-inositol, and scyllo-inositol levels in malignant samples. A statistical analysis with a receiver operating characteristic curve revealed that 77% of the samples were accurately predicted. Similar results were obtained with specimens obtained from ex vivo aspirates. A further development of this project will be to use the metabolomics approach on specimens obtained from aspirates in vivo after the resolution of technical problems attributable to possible contamination. Copyright © 2012 Mosby, Inc. All rights reserved.

  10. Sliding behavior of oil droplets on nanosphere stacking layers with different surface textures

    Science.gov (United States)

    Hsieh, Chien-Te; Wu, Fang-Lin; Chen, Wei-Yu

    2010-09-01

    Two facile coating techniques, gravitational sediment and spin coating, were applied for the creation of silica sphere stacking layers with different textures onto glass substrates that display various sliding abilities toward liquid drops with different surface tensions, ranged from 25.6 to 72.3 mN/m. The resulting silica surface exhibits oil repellency, long-period durability > 30 days, and oil sliding capability. The two-tier texture offers a better roll-off ability toward liquid drops with a wide range of γL, ranged from 30.2 to 72.3 mN/m, i.e., when the sliding angle (SA) surface. This improvement of sliding ability can be ascribed to the fact that the two-tier texture allows for air pockets (i.e., referred to as the Cassie state), thus favoring the self-cleaning ability. Taking Young-Duprè equation into account, a linearity relationship between sine SA and work of adhesion ( Wad) appears to describe the sliding behavior within the Wad region: 2.20-3.03 mN/m. The smaller Wad, the easier drop sliding (i.e., the smaller SA value) takes place on the surfaces. The Wad value ˜3.03 mN/m shows a critical kinetic barrier for drop sliding on the silica surfaces from stationary to movement states. This work proposes a mathematical model to simulate the sliding behavior of oil drops on a nanosphere stacking layer, confirming the anti-oil contamination capability.

  11. schistosomal appendicitis in a sliding hernia (case report)

    African Journals Online (AJOL)

    We report a rare case of a forty-seven year old Nigeria male with schistosomal appendicitis in a sliding hernia. The clinical and pathological features of the case are discussed, followed by a review of the literature. It is concluded that a high index of suspicion is necessary to diagnose unusual presentations of ...

  12. A grain boundary sliding model for cavitation, crack growth and ...

    African Journals Online (AJOL)

    A model is presented for cavity growth, crack propagation and fracture resulting from grain boundary sliding (GBS) during high temperature creep deformation. The theory of cavity growth by GBS was based on energy balance criteria on the assumption that the matrix is sufficiently plastic to accommodate misfit strains ...

  13. Lubricated sliding wear behaviour of Ni-P-W multilayered alloy coatings produced by pulse plating

    DEFF Research Database (Denmark)

    Panagopoulos, C. N.; Papachristos, V. D.; Christoffersen, Lasse

    2000-01-01

    The lubricated sliding wear behaviour of Ni-P-W multilayered alloy coatings sliding against hardened steel discs was studied, in a pin-on-disc set-up. The multilayered coatings had been deposited on mild steel pins by pulse plating and they consisted of ternary Ni-P-W layers of high and low W...

  14. Spin Funneling for Enhanced Spin Injection into Ferromagnets

    Science.gov (United States)

    Sayed, Shehrin; Diep, Vinh Q.; Camsari, Kerem Yunus; Datta, Supriyo

    2016-07-01

    It is well-established that high spin-orbit coupling (SOC) materials convert a charge current density into a spin current density which can be used to switch a magnet efficiently and there is increasing interest in identifying materials with large spin Hall angle for lower switching current. Using experimentally benchmarked models, we show that composite structures can be designed using existing spin Hall materials such that the effective spin Hall angle is larger by an order of magnitude. The basic idea is to funnel spins from a large area of spin Hall material into a small area of ferromagnet using a normal metal with large spin diffusion length and low resistivity like Cu or Al. We show that this approach is increasingly effective as magnets get smaller. We avoid unwanted charge current shunting by the low resistive NM layer utilizing the newly discovered phenomenon of pure spin conduction in ferromagnetic insulators via magnon diffusion. We provide a spin circuit model for magnon diffusion in FMI that is benchmarked against recent experiments and theory.

  15. Emergence of a 2d macro-spin liquid in a highly frustrated 3d quantum magnet

    Science.gov (United States)

    Sikkenk, Tycho; Coester, Kris; Buhrandt, Stefan; Fritz, Lars; Schmidt, Kai

    The classical Ising model on the frustrated 3d swedenborgite lattice has disordered spin liquid ground states for all ratios of inter- and intra-planar couplings. Quantum fluctuations due to a transverse field give rise to several exotic phenomena. In the limit of weakly coupled kagome layers we find a 3d version of disorder by disorder degeneracy lifting. For large out-of-plane couplings 1d macro-spins are formed, which realize a disordered macro-spin liquid phase on an emerging 2d triangular lattice. We speculate about a possibly exotic version of quantum criticality that connects the polarized phase to the macro-spin liquid. DFG FR 2627/3-1, D-ITP consortium.

  16. Slow Magic Angle Sample Spinning: A Non- or Minimally Invasive Method for High- Resolution 1H Nuclear Magnetic Resonance (NMR) Metabolic Profiling

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Jian Z.

    2011-05-01

    High resolution 1H magic angle spinning nuclear magnetic resonance (NMR), using a sample spinning rate of several kHz or more (i.e., high resolution-magic angle spinning (hr-MAS)), is a well established method for metabolic profiling in intact tissues without the need for sample extraction. The only shortcoming with hr-MAS is that it is invasive and is thus unusable for non-destructive detections. Recently, a method called slow-MAS, using the concept of two dimensional NMR spectroscopy, has emerged as an alternative method for non- or minimal invasive metabolomics in intact tissues, including live animals, due to the slow or ultra-slow-sample spinning used. Although slow-MAS is a powerful method, its applications are hindered by experimental challenges. Correctly designing the experiment and choosing the appropriate slow-MAS method both require a fundamental understanding of the operation principles, in particular the details of line narrowing due to the presence of molecular diffusion. However, these fundamental principles have not yet been fully disclosed in previous publications. The goal of this chapter is to provide an in depth evaluation of the principles associated with slow-MAS techniques by emphasizing the challenges associated with a phantom sample consisting of glass beads and H2O, where an unusually large magnetic susceptibility field gradient is obtained.

  17. Crocus sativus Petals: Waste or Valuable Resource? The Answer of High-Resolution and High-Resolution Magic Angle Spinning Nuclear Magnetic Resonance.

    Science.gov (United States)

    Righi, Valeria; Parenti, Francesca; Tugnoli, Vitaliano; Schenetti, Luisa; Mucci, Adele

    2015-09-30

    Intact Crocus sativus petals were studied for the first time by high-resolution magic angle spinning nuclear magnetic resonance (HR-MAS NMR) spectroscopy, revealing the presence of kinsenoside (2) and goodyeroside A (3), together with 3-hydroxy-γ-butyrolactone (4). These findings were confirmed by HR-NMR analysis of the ethanol extract of fresh petals and showed that, even though carried out rapidly, partial hydrolysis of glucopyranosyloxybutanolides occurs during extraction. On the other hand, kaempferol 3-O-sophoroside (1), which is "NMR-silent" in intact petals, is present in extracts. These results suggest to evaluate the utilization of saffron petals for phytopharmaceutical and nutraceutical purposes to exploit a waste product of massive production of commercial saffron and point to the application of HR-MAS NMR for monitoring bioactive compounds directly on intact petals, avoiding the extraction procedure and the consequent hydrolysis reaction.

  18. Characterization of Free Radicals By Electron Spin Resonance Spectroscopy in Biochars from Pyrolysis at High Heating Rates and at High Temperatures

    DEFF Research Database (Denmark)

    Trubetskaya, Anna; Jensen, Anker Degn; Larsen Andresen, Mogens

    of mathematical models that can predict yields, composition and rates of product (char, tar, light gases) formation from fast pyrolysis. The modeling of cross-linking and polymerization reactions in biomass pyrolysis includes the formation of free radicals and their disappearance. Knowledge about these radical...... reactions is important in order to achieve the high fuel conversion at short residence times. However, little is known about the extent of free radical reactions in pulverized biomass at fast pyrolysis conditions.The concentration and type of free radicals from the decay (termination stage) of pyrolysis...... reactor, an entrained-flow reactor, and a tubular reactor. The radical concentrations in the chars from the decay stage range up between 7x1018 and 1.5x1019 spins g-1.The results indicated that any differences in the biomass major constituents (cellulose, hemicellulose, lignin) had a minor effect...

  19. Experimental Flight Characterization of Spin Stabilized Projectiles at High Angle of Attack

    Science.gov (United States)

    2017-08-07

    about 2 m from the spark range entrance. The propelling charge used 1.18 kg of M1 propellant with about 30 gr of black powder for the primer. These...along with some wake flow structures trailing the body. Approved for public release; distribution is unlimited. 7 Fig. 2 Orthogonal...continuous polynomial does not represent the underlying flow phenomena at high angle of attack. There is little data in the literature on the axial force for

  20. High-spin states of the neutron-rich nucleus sup 1 sup 2 sup 5 Sb

    CERN Document Server

    Liu Zhong; Ma Yin Gjun; Sasaki, Y; Yamada, K; Oshima, H; Yokose, S; Ishizuka, M; Komatsubara, T; Furuno, K

    2002-01-01

    High spin states of sup 1 sup 2 sup 5 Sb have been investigated for the first time by means of in-beam gamma-ray spectroscopy techniques via the sup 1 sup 2 sup 4 Sn( sup 7 Li, alpha 2n) reaction at 32 MeV beam energy. Based on the measurements of gamma-gamma coincidence and gamma-ray anisotropies, a level scheme including 21 new gamma-transitions and 14 new excited levels was established up to 23/2 sup +. Three isomers at 1970, 2110 and 2471 keV levels have been identified and proposed as three-quasiparticle pi g sub 7 sub / sub 2 nu(h sub 1 sub 1 sub / sub 2 s sub 1 sub / sub 2), pi g sub 7 sub / sub 2 nu(h sub 1 sub 1 sub / sub 2 d sub 3 sub / sub 2) and pi g sub 7 sub / sub 2 nu(h sub 1 sub 1 sub / sub 2 sup 2) configurations, respectively. The level structure of sup 1 sup 2 sup 5 Sb is discussed in terms of particle-core coupling

  1. Alkylation of a bioinspired high spin Ni(II)N{sub 3}S{sub 2} complex with bifunctional reagents

    Energy Technology Data Exchange (ETDEWEB)

    Chohan, B. S., E-mail: bsc12@psu.edu [The Pennsylvania State University, Department of Chemistry (United States)

    2013-12-15

    Crystal structures of two S-alkylated complexes generated from the reaction of iodoacetamide and iodoethanol with an air and moisture sensitive high spin Ni(II) pentacoordinate triaminodithiolate complex, 1 are determined by X-ray structure analysis. Crystals of complex 2, [NiC{sub 16}H{sub 31}N{sub 5}O{sub 2}S{sub 2}]I{sub 2}, are triclinic, sp. gr. P-bar1 , Z = 2. Crystals of complex 3, [NiC{sub 16}H{sub 28}N{sub 3}O{sub 2}S{sub 2}]I{sub 2}, are monoclinic, sp. gr. P2{sub 1}/c, Z = 4. Structures of complexes 2 and 3 are very similar: one of the S-acetamide (2) or S-ethanol (3) groups coordinates to the Ni center through the oxygen atom forming N{sub 3}S{sub 2}O hexacoordination; the other group remains unbound to the Ni and left dangling. Crystal packing shows that complexes 2 and 3 interact with the iodide counterions, and that only complex 2 interact with neighboring molecules; some of these close intermolecular contacts include H-bonding interactions.

  2. Using Art and Architecture Slides in Sociology.

    Science.gov (United States)

    Barthel, Diane

    1987-01-01

    Describes how slides of architecture and classical art may be used to help students think sociologically, to understand not only what sociology is, but why it exists. Identifies eight themes on which slides of art and architecture may be used. Among the themes are: culture contact and change; concepts of self; the rise of industrial society;…

  3. Using Sliding Modes in Control Theory

    Directory of Open Access Journals (Sweden)

    Renata Wagnerová

    2008-03-01

    Full Text Available The paper deals with sliding modes control design. The described control algorithms were applied to position control of the levitating systems in magnetic field. The designed control algorithms were verified by using computer simulations. The results achieved confirm suitable technical means and synthesis by using sliding modes for nonlinear control tasks.

  4. The Cancer Digital Slide Archive - TCGA

    Science.gov (United States)

    Dr. David Gutman and Dr. Lee Cooper developed The Cancer Digital Slide Archive (CDSA), a web platform for accessing pathology slide images of TCGA samples. Find out how they did it and how to use the CDSA website in this Case Study.

  5. Evaluating the visibility of presentation slides

    Science.gov (United States)

    Sugawara, Genki; Umezu, Nobuyuki

    2017-03-01

    Presentations using slide software such as PowerPoint are widely performed in offices and schools. The improvement of presentation skills among ordinary people is required because these days such an opportunity of giving presentation is becoming so common. One of the key factors for making successful presentation is the visibility of the slides, as well as the contents themselves. We propose an algorithm to numerically evaluate the visibility of presentation slides. Our method receives a presentation as a set of images and eliminates the background from the slides to extract characters and figures. This algorithm then evaluates the visibility according to the number and size of characters, their colors, and figure layouts. The slide evaluation criteria are based on the series of experiments with 20 participants to parameterize typical values for visual elements in slides. The algorithm is implemented on an iMac and takes 0.5 sec. to evaluate a slide image. The evaluation score is given as a value between 0 and 100 and the users can improve their slide pages with lower scores. Our future work includes a series of experiments with various presentations and extending our method to publish as a web-based rating service for learning presentation skills.

  6. Surface Interactions and Confinement of Methane: A High Pressure Magic Angle Spinning NMR and Computational Chemistry Study

    Energy Technology Data Exchange (ETDEWEB)

    Ok, Salim; Hoyt, David W.; Andersen, Amity; Sheets, Julie; Welch, Susan A.; Cole, David R.; Mueller, Karl T.; Washton, Nancy M.

    2017-01-18

    Characterization and modeling of the molecular-level behavior of simple hydrocarbon gases, such as methane, in the presence of both nonporous and nano-porous mineral matrices allows for predictive understanding of important processes in engineered and natural systems. In this study, changes in local electromagnetic environments of the carbon atoms in methane under conditions of high pressure (up to 130 bar) and moderate temperature (up to 346 K) were observed with 13C magic-angle spinning (MAS) NMR spectroscopy while the methane gas was mixed with two model solid substrates: a fumed non-porous, 12 nm particle size silica and a mesoporous silica with 200 nm particle size and 4 nm average pore diameter. Examination of the interactions between methane and the silica systems over temperatures and pressures that include the supercritical regime was allowed by a novel high pressure MAS sample containment system, which provided high resolution spectra collected under in situ conditions. For pure methane, no significant thermal effects were found for the observed 13C chemical shifts at all pressures studied here (28.2 bar, 32.6 bar, 56.4 bar, 65.1 bar, 112.7 bar, and 130.3 bar). However, the 13C chemical shifts of resonances arising from confined methane changed slightly with changes in temperature in mixtures with mesoporous silica. The chemical shift values of 13C nuclides in methane change measurably as a function of pressure both in the pure state and in mixtures with both silica matrices, with a more pronounced shift when meso-porous silica is present. Molecular-level simulations utilizing GCMC, MD and DFT confirm qualitatively that the experimentally measured changes are attributed to interactions of methane with the hydroxylated silica surfaces as well as densification of methane within nanopores and on pore surfaces.

  7. Crossover from Spin Accumulation into Interface States to Spin Injection in the Germanium Conduction Band

    Science.gov (United States)

    Rojas-Sanchez, Juan-Carlos; Jain, Abhinav; Cubukcu, Murat; Peiro, Julian; Le Breton, Jean-Christophe; Prestat, Eric; Vergnaud, Céline; Bayle-Guillemaud, Pascale; Vila, Laurent; Attané, Jean-Philippe; Augendre, Emmanuel; Gambarelli, Serge; Jaffrès, Henri; George, Jean-Marie; Jamet, Matthieu

    2013-03-01

    Spin injection into semiconductors is crucial for exploring spin physics and new spintronic devices. Ge is of great interest for high carrier mobilities, long spin diffusion length and large spin-orbit coupling to perform electric field spin manipulation. However the exact role of interface states in spin injection mechanism in n-Ge has not been clarified yet. Here we show a clear transition from spin accumulation into interface states to spin injection in the Ge conduction band. For this purpose, we have grown CoFeB/MgO as a spin injector on Germanium On Insulator. We observe spin signal amplification at low temperature due to spin accumulation into interface states. At 150 K, we find a clear transition to spin injection in the conduction band up to room temperature: the measured spin signal is compatible with the spin diffusion model. We could in particular demonstrate spin signal modulation applying a back gate voltage and spin-pumping by the ferromagnetic resonance of the CoFeB layer which are clear manifestations of spin accumulation in the Ge conduction band.

  8. Low energy nuclear spin excitations in Ho metal investigated by high resolution neutron spectroscopy.

    Science.gov (United States)

    Chatterji, Tapan; Jalarvo, Niina

    2013-04-17

    We have investigated the low energy excitations in metallic Ho by high resolution neutron spectroscopy. We found at T = 3 K clear inelastic peaks in the energy loss and energy gain sides, along with the central elastic peak. The energy of this low energy excitation, which is 26.59 ± 0.02 μeV at T = 3 K, decreased continuously and became zero at TN ≈ 130 K. By fitting the data in the temperature range 100-127.5 K with a power law we obtained the power-law exponent β = 0.37 ± 0.02, which agrees with the expected value β = 0.367 for a three-dimensional Heisenberg model. Thus the energy of the low energy excitations can be associated with the order parameter.

  9. Quantum Spin Models for Copper Oxide Chains in High-T{sub c} Superconductors

    Energy Technology Data Exchange (ETDEWEB)

    Haugerud, H.

    1996-12-31

    This doctoral thesis presents some of the most important features of high temperature superconductors, emphasizing the properties of YBa{sub 2}Cu{sub 3}O{sub 6+x} (YBCO). The family of Hubbard-like models is considered and a simplified version of the Emery model derived. This model is applied to fermions on a cyclic chain and solved analytically in the strong correlation limit. For realistic model parameter values the effects of an external magnetic field is investigated by numerical diagonalization. Applying the Emery model to finite cyclic Cu-O chains it is shown that the behaviour of the chains is typical for a 1D Fermi-liquid. The relatively small difference between the values of the local charge and the local magnetic moment indicates that the degree of correlation in this system is very high. The ground state of the Emery model is shown to be antiferromagnetic for half and quarter filling, resembling the ground state of the Heisenberg model. The role of the ensemble of Cu-O chain fragments of the oxygen deficient planes of YBCO is addressed. By applying the Emery model to short Cu-O chains and calculating the free energy of the chains, the parameters of an Ising like lattice gas model are estimated. Several thermodynamical quantities are calculated by applying Monte Carlo technique to the model. The charge transfer from the chains to the planes is shown to correspond to the measured values of T{sub c}. The phase diagram and the average chain length agree well with experiments. The model is also capable of explaining the behaviour of the REBCO series of superconductors, where RE are various rare earth ions. A framework for simultaneously visualizing and computing numerical quantities from lattice simulations is presented and illustrated. 195 refs., 69 figs., 4 tabs.

  10. High resolution NMR study of T1 magnetic relaxation dispersion. III. Influence of spin 1/2 hetero-nuclei on spin relaxation and polarization transfer among strongly coupled protons

    NARCIS (Netherlands)

    Korchak, S.E.; Ivanov, K.L.; Pravdivtsev, A.N.; Yurkovskaya, A.V.; Kaptein, R.|info:eu-repo/dai/nl/074334603; Vieth, H.-M.

    2012-01-01

    Effects of spin-spin interactions on the nuclear magnetic relaxation dispersion (NMRD) of protons were studied in a situation where spin ½ hetero-nuclei are present in the molecule. As in earlier works [K. L. Ivanov, A. V. Yurkovskaya, and H.-M. Vieth, J. Chem. Phys. 129, 234513

  11. Nonsingular Terminal Sliding Mode Control of Uncertain Second-Order Nonlinear Systems

    Directory of Open Access Journals (Sweden)

    Minh-Duc Tran

    2015-01-01

    Full Text Available This paper presents a high-performance nonsingular terminal sliding mode control method for uncertain second-order nonlinear systems. First, a nonsingular terminal sliding mode surface is introduced to eliminate the singularity problem that exists in conventional terminal sliding mode control. By using this method, the system not only can guarantee that the tracking errors reach the reference value in a finite time with high-precision tracking performance but also can overcome the complex-value and the restrictions of the exponent (the exponent should be fractional number with an odd numerator and an odd denominator in traditional terminal sliding mode. Then, in order to eliminate the chattering phenomenon, a super-twisting higher-order nonsingular terminal sliding mode control method is proposed. The stability of the closed-loop system is established using the Lyapunov theory. Finally, simulation results are presented to illustrate the effectiveness of the proposed method.

  12. Protein sliding and hopping kinetics on DNA

    CERN Document Server

    DeSantis, Michael C; Wang, Y M

    2010-01-01

    Using Monte-Carlo simulations, we deconvolved the sliding and hopping kinetics of GFP-LacI proteins on elongated DNA from their experimentally observed seconds-long diffusion trajectories. Our simulations suggest the following results: (1) in each diffusion trajectory, a protein makes on average hundreds of alternating slides and hops with a mean sliding time of several tens of ms; (2) sliding dominates the root mean square displacement of fast diffusion trajectories, whereas hopping dominates slow ones; (3) flow and variations in salt concentration have limited effects on hopping kinetics, while in vivo DNA configuration is not expected to influence sliding kinetics; furthermore, (4) the rate of occurrence for hops longer than 200 nm agrees with experimental data for EcoRV proteins.

  13. Incipient- and Developed-Spin and Recovery Characteristics of a Modern High-Speed Fighter Design with Low Aspect Ratio as Determined from Dynamic-Model Tests

    Science.gov (United States)

    Lee, Henry A.; Libbey, Charles E.

    1961-01-01

    Incipient- and developed-spin and recovery characteristics of a modern high-speed fighter design with low aspect ratio have been investigated by means of dynamic model tests. A 1/7-scale radio-controlled model was tested by means of drop tests from a helicopter. Several 1/25-scale models with various configuration changes were tested in the Langley 20-foot free-spinning tunnel. Model results indicated that generally it would be difficult to obtain a developed spin with a corresponding airplane and that either the airplane would recover of its own accord from any poststall motion or the poststall motion could be readily terminated by proper control technique. On occasion, however, the results indicated that if a post-stall motion were allowed to continue, a fully developed spin might be obtainable from which recovery could range from rapid to no recovery at all, even when optimum control technique was used. Satisfactory recoveries could be obtained with a proper-size tail parachute or strake, application of pitching-, rolling-, or yawing-moment rockets, or sufficient differential deflection of the horizontal tail.

  14. Vaporization of Kitaev spin liquids.

    Science.gov (United States)

    Nasu, Joji; Udagawa, Masafumi; Motome, Yukitoshi

    2014-11-07

    The quantum spin liquid is an exotic quantum state of matter in magnets. This state is a spin analog of liquid helium that does not solidify down to the lowest temperature due to strong quantum fluctuations. In conventional fluids, the liquid and gas possess the same symmetry and adiabatically connect to each other by bypassing the critical end point. We find that the situation is qualitatively different in quantum spin liquids realized in a three-dimensional Kitaev model; both gapless and gapped quantum spin liquid phases at low temperatures are always distinguished from the high-temperature paramagnet (spin gas) by a phase transition. The results challenge the common belief that the absence of thermodynamic singularity down to the lowest temperature is a symptom of a quantum spin liquid.

  15. Spin liquids in frustrated magnets.

    Science.gov (United States)

    Balents, Leon

    2010-03-11

    Frustrated magnets are materials in which localized magnetic moments, or spins, interact through competing exchange interactions that cannot be simultaneously satisfied, giving rise to a large degeneracy of the system ground state. Under certain conditions, this can lead to the formation of fluid-like states of matter, so-called spin liquids, in which the constituent spins are highly correlated but still fluctuate strongly down to a temperature of absolute zero. The fluctuations of the spins in a spin liquid can be classical or quantum and show remarkable collective phenomena such as emergent gauge fields and fractional particle excitations. This exotic behaviour is now being uncovered in the laboratory, providing insight into the properties of spin liquids and challenges to the theoretical description of these materials.

  16. Postoperative arachnoiditis diagnosed by high resolution fast spin-echo MRI of the lumbar spine

    Energy Technology Data Exchange (ETDEWEB)

    Fitt, G.J. [St. Mary`s Hospital, London (United Kingdom). Dept. of Radiology; Stevens, J.M. [St. Mary`s Hospital, London (United Kingdom). Dept. of Radiology]|[National Hospital for Neurology and Neurosurgery, London (United Kingdom)

    1995-02-01

    Chronic adhesive arachnoiditis is cited as an important cause of recurrent pain and disability after extradural lumbar disc surgery. Myelography using oil-based or ionic water-soluble contrast media was a major contributing factor, and it was not possible to distinguish the prevalence of arachnoiditis probably due to surgery alone. Today it should be possible to make this distinction, which was the purpose of this study. Using high-resolution MRI in 129 patients symptomatic at least 1 year after surgery, a prevalence of arachnoiditis of 20% was found, which dropped to 3% when patients who had undergone oil-based myelography were excluded. Arachnoiditis was diffuse in 88% and focal in 12%. When oil-based media were involved it was focal in 13%, and when not, in one of three cases. It was concluded that arachnoiditis does occur after extradural lumbar disc surgery independently of the use of some myelographic contrast media, and that it may be diffuse or confined only to the operated level. Its prevalence was estimated at 4.6%, four cases focal and two cases diffuse. The causes and clinical significance can only be the subject of speculation. (orig.)

  17. Spin ejector

    Science.gov (United States)

    Andersen, John A.; Flanigan, John J.; Kindley, Robert J.

    1978-01-01

    The disclosure relates to an apparatus for spin ejecting a body having a flat plate base containing bosses. The apparatus has a base plate and a main ejection shaft extending perpendicularly from the base plate. A compressible cylindrical spring is disposed about the shaft. Bearings are located between the shaft and the spring. A housing containing a helical aperture releasably engages the base plate and surrounds the shaft bearings and the spring. A piston having an aperture follower disposed in the housing aperture is seated on the spring and is guided by the shaft and the aperture. The spring is compressed and when released causes the piston to spin eject the body.

  18. High resolution NMR study of T1 magnetic relaxation dispersion. III. Influence of spin 1/2 hetero-nuclei on spin relaxation and polarization transfer among strongly coupled protons.

    Science.gov (United States)

    Korchak, Sergey E; Ivanov, Konstantin L; Pravdivtsev, Andrey N; Yurkovskaya, Alexandra V; Kaptein, Robert; Vieth, Hans-Martin

    2012-09-07

    Effects of spin-spin interactions on the nuclear magnetic relaxation dispersion (NMRD) of protons were studied in a situation where spin ½ hetero-nuclei are present in the molecule. As in earlier works [K. L. Ivanov, A. V. Yurkovskaya, and H.-M. Vieth, J. Chem. Phys. 129, 234513 (2008); S. E. Korchak, K. L. Ivanov, A. V. Yurkovskaya, and H.-M. Vieth, ibid. 133, 194502 (2010)], spin-spin interactions have a pronounced effect on the relaxivity tending to equalize the longitudinal relaxation times once the spins become strongly coupled at a sufficiently low magnetic field. In addition, we have found influence of (19)F nuclei on the proton NMRD, although in the whole field range, studied protons and fluorine spins were only weakly coupled. In particular, pronounced features in the proton NMRD were found; but each feature was predominantly observed only for particular spin states of the hetero-nuclei. The features are explained theoretically; it is shown that hetero-nuclei can affect the proton NMRD even in the limit of weak coupling when (i) protons are coupled strongly and (ii) have spin-spin interactions of different strengths with the hetero-nuclei. We also show that by choosing the proper magnetic field strength, one can selectively transfer proton spin magnetization between spectral components of choice.

  19. High temperature spin state transitions in misfit-layered Ca{sub 3}Co{sub 4}O{sub 9}

    Energy Technology Data Exchange (ETDEWEB)

    Altin, S.; Aksan, M.A., E-mail: mehmet.aksan@inonu.edu.tr; Bayri, A.

    2014-02-25

    Highlights: • Ca{sub 3}Co{sub 4}O{sub 9} system has been fabricated using the solid-state technique. • There is an anomaly in magnetic the susceptibility χ between 680 and 920 K. • The anomaly is related to a critical threshold number of the high spin Co-ions. • The anomaly was also observed in the B and Sb-substituted Ca{sub 3}Co{sub 4}O{sub 9}. -- Abstract: This study reports high temperature magnetic properties of the unsubstituted one together with B and Sb-substituted Ca{sub 3}Co{sub 4}O{sub 9} system. The measured data indicated that there is an anomaly in the magnetic susceptibility, χ, between 680 and 920 K. It is believed that this anomaly is related to a critical threshold number of the high spin Co-ions such that when this threshold number is achieved, some exchange interactions between Co{sup 3+} and Co{sup 4+} take place which causes an abrupt increase in the χ–T curve. The anomaly was further investigated with B and Sb-substitutions. It is realized that both dopants promote more Co-ions in the rock salt unit cell to high spin state.

  20. Intrinsic parton motion soft mechanisms and the longitudinal spin asymmetry ALL in high energy pp → πX

    Science.gov (United States)

    Anselmino, M.; Boglione, M.; D'Alesio, U.; Leader, E.; Melis, S.; Murgia, F.

    2009-01-01

    The longitudinal double spin asymmetry ALL in the reaction pp → πX has been measured at RHIC with extremely interesting consequences. If the gluon polarization in a proton were as big as needed to resolve the famous 'spin crisis' then ALL would be large and positive. Latest RHIC results indicate that ALL is small and disfavour large positive values of the gluon polarization. We examine whether the soft mechanisms (Collins, Sivers, Boer-Mulders), essential for generating transverse single spin asymmetries, have any significant influence on ALL, and whether they could alter the conclusion that the gluon polarization is necessarily small. It turns out that the contribution from these effects is essentially negligible.

  1. Spin Superfluidity in Biaxial Antiferromagnetic Insulators

    Science.gov (United States)

    Qaiumzadeh, Alireza; Skarsvâg, Hans; Holmqvist, Cecilia; Brataas, Arne

    2017-03-01

    Antiferromagnets may exhibit spin superfluidity since the dipole interaction is weak. We seek to establish that this phenomenon occurs in insulators such as NiO, which is a good spin conductor according to previous studies. We investigate nonlocal spin transport in a planar antiferromagnetic insulator with a weak uniaxial anisotropy. The anisotropy hinders spin superfluidity by creating a substantial threshold that the current must overcome. Nevertheless, we show that applying a high magnetic field removes this obstacle near the spin-flop transition of the antiferromagnet. Importantly, the spin superfluidity can then persist across many micrometers, even in dirty samples.

  2. Wall Area of Influence and Growing Wall Heat Transfer due to Sliding Bubbles in Subcooled Boiling Flow

    Energy Technology Data Exchange (ETDEWEB)

    Yoo, Junsoo; Estrada-Perez, Carlos E.; Hassan, Yassin A.

    2016-04-01

    A variety of dynamical features of sliding bubbles and their impact on wall heat transfer were observed at subcooled flow boiling conditions in a vertical square test channel. Among the wide range of parameters observed, we particularly focus in this paper on (i) the sliding bubbles’ effect on wall heat transfer (supplemantry discussion to the authors’ previous work in Yoo et al. (2016a,b)) and (ii) the wall area influenced by sliding bubbles in subcooled boiling flow. At first, this study reveals that the degree of wall heat transfer improvement due to sliding bubbles depended less on the wall superheat condition as the mass flux increased. Also, the sliding bubble trajectory was found to be one of the critical factors in order to properly describe the wall heat transfer associated with sliding bubbles. In particular, the wall area influenced by sliding bubbles depended strongly on both sliding bubble trajectory and sliding bubble size; the sliding bubble trajectory was also observed to be closely related to the sliding bubble size. Importantly, these results indicate the limitation of current approach in CFD analyses especially for the wall area of bubble influence. In addition, the analyses on the temporal fraction of bubbles’ residence (FR) along the heated wall show that the sliding bubbles typically travel through narrow path with high frequency while the opposite was observed downstream. That is, both FR and sliding bubble trajectory depended substantially on the distance from nucleation site, which is expected to be similar for the quenching heat transfer mode induced by sliding bubbles.

  3. Whole slide imaging for educational purposes

    Directory of Open Access Journals (Sweden)

    Liron Pantanowitz

    2012-01-01

    Full Text Available Digitized slides produced by whole slide image scanners can be easily shared over a network or by transferring image files to optical or other data storage devices. Navigation of digitized slides is interactive and intended to simulate viewing glass slides with a microscope (virtual microscopy. Image viewing software permits users to edit, annotate, analyze, and easily share whole slide images (WSI. As a result, WSI have begun to replace the traditional light microscope, offering a myriad of opportunities for education. This article focuses on current applications of WSI in education and proficiency testing. WSI has been successfully explored for graduate education (medical, dental, and veterinary schools, training of pathology residents, as an educational tool in allied pathology schools (e.g., cytotechnology, for virtual tracking and tutoring, tele-education (tele-conferencing, e-learning, virtual workshops, at tumor boards, with interactive publications, and on examinations. WSI supports flexible and cost-effective distant learning and augments problem-oriented teaching, competency evaluation, and proficiency testing. WSI viewed on touchscreen displays and with tablet technology are especially beneficial for education. Further investigation is necessary to develop superior WSI applications that better support education and to design viewing stations with ergonomic tools that improve the WSI-human interface and navigation of virtual slides. Studies to determine the impact of training pathologists without exposure to actual glass slides are also needed.

  4. Whole slide imaging for educational purposes.

    Science.gov (United States)

    Pantanowitz, Liron; Szymas, Janusz; Yagi, Yukako; Wilbur, David

    2012-01-01

    Digitized slides produced by whole slide image scanners can be easily shared over a network or by transferring image files to optical or other data storage devices. Navigation of digitized slides is interactive and intended to simulate viewing glass slides with a microscope (virtual microscopy). Image viewing software permits users to edit, annotate, analyze, and easily share whole slide images (WSI). As a result, WSI have begun to replace the traditional light microscope, offering a myriad of opportunities for education. This article focuses on current applications of WSI in education and proficiency testing. WSI has been successfully explored for graduate education (medical, dental, and veterinary schools), training of pathology residents, as an educational tool in allied pathology schools (e.g., cytotechnology), for virtual tracking and tutoring, tele-education (tele-conferencing), e-learning, virtual workshops, at tumor boards, with interactive publications, and on examinations. WSI supports flexible and cost-effective distant learning and augments problem-oriented teaching, competency evaluation, and proficiency testing. WSI viewed on touchscreen displays and with tablet technology are especially beneficial for education. Further investigation is necessary to develop superior WSI applications that better support education and to design viewing stations with ergonomic tools that improve the WSI-human interface and navigation of virtual slides. Studies to determine the impact of training pathologists without exposure to actual glass slides are also needed.

  5. L-valley electrons in SiGe heterostructures: highly anisotropic and tunable Zeeman and Rashba-like spin splittings

    Science.gov (United States)

    Kiselev, A. A.; Baron, F. A.; Kim, K. W.; Wang, K. L.; Yablonovitch, E.

    2005-06-01

    We have conducted a detailed and systematic analysis of Zeeman and Rashba-like (structure-asymmetry-induced) spin splittings in SiGe heterostructures. The calculations were performed in the framework of a relevant kp model, developed specifically for the L point states of the group IV semiconductors. Effects of the alloy composition, crystallographic orientation, spatial confinement, strain, and electric field are accounted for and documented for a realistic structure design. Notable Rashba effect, considerable anisotropy and deviation of the g tensor components from their respective bulk values make the SiGe structures a friendly choice for the effective spin manipulation.

  6. Sliding-Mode Control of PEM Fuel Cells

    CERN Document Server

    Kunusch, Cristian; Mayosky, Miguel

    2012-01-01

    Recent advances in catalysis technologies and new materials make fuel cells an economically appealing and clean energy source with massive market potential in portable devices, home power generation and the automotive industry. Among the more promising fuel-cell technologies are proton exchange membrane fuel cells (PEMFCs). Sliding-Mode Control of PEM Fuel Cells demonstrates the application of higher-order sliding-mode control to PEMFC dynamics. Fuel-cell dynamics are often highly nonlinear and the text shows the advantages of sliding modes in terms of robustness to external disturbance, modelling error and system-parametric disturbance using higher-order control to reduce chattering. Divided into two parts, the book first introduces the theory of fuel cells and sliding-mode control. It begins by contextualising PEMFCs both in terms of their development and within the hydrogen economy and today’s energy production situation as a whole. The reader is then guided through a discussion of fuel-cell operation pr...

  7. Current Status of Whole-Slide Imaging in Education.

    Science.gov (United States)

    Saco, Adela; Bombi, Jose Antoni; Garcia, Adriana; Ramírez, Jose; Ordi, Jaume

    2016-01-01

    Conventional light microscopy (CLM) has classically been the basic tool to teach histology and pathology. In recent years, whole-slide imaging (WSI), which consists of generating a high-magnification digital image of an entire histological glass slide, has emerged as a useful alternative to CLM offering a myriad of opportunities for education. Navigation through the digitized slides closely simulates viewing glass slides with a microscope and is also referred to as virtual microscopy. WSI has many advantages for education. Students feel more comfortable with its use, and it can be used in any classroom as it only requires a computer with Internet access and it allows remote access from anywhere and from any device. WSI can be used simultaneously by a large number of people, stimulating cooperation between students and improving the interaction with the teachers. It allows making marks and annotations on specific fields, which enable specific directed questions to the teacher. Finally, WSI supports are cost-effective compared with CLM. Consequently, WSI has begun to replace CLM in many institutions. WSI has shown to be an extremely useful tool for undergraduate education (medical, dental and veterinary schools), for the training of residents of pathology, tele-education and in tumor boards. © 2016 S. Karger AG, Basel.

  8. Whole slide imaging: uses and limitations for surgical pathology and teaching.

    Science.gov (United States)

    Boyce, B F

    2015-07-01

    Advances in computer and software technology and in the quality of images produced by digital cameras together with development of robotic devices that can take glass histology slides from a cassette holding many slides and place them in a conventional microscope for electronic scanning have facilitated the development of whole slide imaging (WSI) systems during the past decade. Anatomic pathologists now have opportunities to test the utility of WSI systems for diagnostic, teaching and research purposes and to determine their limitations. Uses include rendering primary diagnoses from scanned hematoxylin and eosin stained tissues on slides, reviewing frozen section or routine slides from remote locations for interpretation or consultation. Also, WSI can replace physical storage of glass slides with digital images, storing images of slides from outside institutions, presenting slides at clinical or research conferences, teaching residents and medical students, and storing fluorescence images without fading or quenching of the fluorescence signal. Limitations include the high costs of the scanners, maintenance contracts and IT support, storage of digital files and pathologists' lack of familiarity with the technology. Costs are falling as more devices and systems are sold and cloud storage costs drop. Pathologist familiarity with the technology will grow as more institutions purchase WSI systems. The technology holds great promise for the future of anatomic pathology.

  9. Design and analysis of adaptive Super-Twisting sliding mode control for a microgyroscope

    Science.gov (United States)

    Feng, Zhilin

    2018-01-01

    This paper proposes a novel adaptive Super-Twisting sliding mode control for a microgyroscope under unknown model uncertainties and external disturbances. In order to improve the convergence rate of reaching the sliding surface and the accuracy of regulating and trajectory tracking, a high order Super-Twisting sliding mode control strategy is employed, which not only can combine the advantages of the traditional sliding mode control with the Super-Twisting sliding mode control, but also guarantee that the designed control system can reach the sliding surface and equilibrium point in a shorter finite time from any initial state and avoid chattering problems. In consideration of unknown parameters of micro gyroscope system, an adaptive algorithm based on Lyapunov stability theory is designed to estimate the unknown parameters and angular velocity of microgyroscope. Finally, the effectiveness of the proposed scheme is demonstrated by simulation results. The comparative study between adaptive Super-Twisting sliding mode control and conventional sliding mode control demonstrate the superiority of the proposed method. PMID:29298297

  10. An Ion Gel as a Low-Cost, Spin-Coatable, High-Capacitance Dielectric for Electrowetting-on-Dielectric (EWOD).

    Science.gov (United States)

    Narasimhan, Vinayak; Park, Sung-Yong

    2015-08-04

    For many practical electrowetting-on-dielectric (EWOD) applications, the use of high-capacitance dielectric materials is critically demanded to induce a large surface tension modulation. Thin-film dielectric layers such as Parylene C, silicon dioxide (SiO2), and aluminum oxide (Al2O3) have been commonly used for EWOD. However, these dielectric materials are fabricated by conventional integrated circuit (IC) processes which are typically time-consuming and require complex and expensive laboratory setups such as high-vacuum facilities. In this article, a novel ion gel material was demonstrated as a spin-coatable and high-capacitance dielectric for low-cost EWOD applications. The ion gel offers a 2 or 3 order higher capacitance (c ≈ 10 μF/cm(2)) than conventional dielectrics commonly used for EWOD while being fabricated through a simple low-cost spin-coating process. We discuss the fundamentals of an ion gel dielectric, its fabrication process of spin coating, and the interaction with a hydrophobic layer for practical EWOD applications. The ion gel films, which consist of a copolymer, poly(vinylidene fluoride-co-hexafluoropropylene) [P(VDF-HFP)], and an ionic liquid, 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide [EMIM][TFSI], were successfully deposited on ITO substrates by using a simple spin-coating process. The experimental demonstrations validated the theoretical modeling of the ion gel layer as a high-capacitance dielectric. The EWOD performance of the ion gel samples was compared to that of other conventional dielectric materials to show the performance improvement.

  11. Comparison of three high-flow single-stage impaction-based air samplers for bacteria quantification: DUO SAS SUPER 360, SAMPL'AIR and SPIN AIR

    OpenAIRE

    Sánchez-Muñoz, Marta; Muñoz-Vicente, María; Cobas, Guillermo; Portela, Raquel; Amils, Ricardo; Sánchez, Benigno

    2012-01-01

    Indoor Air Quality (IAQ) can be significantly deteriorated by high levels of bioaerosols that may cause adverse health effects in building occupants. There is no standard method for the quantification of this kind of pollutants and several protocols and sampling devices are used. The aim of this work was to compare three commonly used portable air samplers available in the market. DUO SAS SUPER 360, SAMPL'AIR and SPIN AIR units were tested simultaneously for bacteria quantification in a labor...

  12. Spin rotation and oscillations for high energy particles in a crystal and possibility to measure the quadrupole moments and tensor polarizabilities of elementary particles and nuclei

    OpenAIRE

    Baryshevsky, V. G.; Gurinovich, A. A.

    2005-01-01

    It is shown that particle motion in a bent (straight) crystal is accompanied by particle spin rotation and oscillations that allows to measure the tensor electric and magnetic polarizabilities of nuclei and elementary particles. It is shown that channelling of particles in either straight or bent crystal with the polarized nuclei could be used both to analyze polarization of high energy particles and polarize them.

  13. Switching ferromagnetic spins by an ultrafast laser pulse: Emergence of giant optical spin-orbit torque

    Science.gov (United States)

    Zhang, G. P.; Bai, Y. H.; George, Thomas F.

    2016-09-01

    Faster magnetic recording technology is indispensable to massive data storage and big data sciences. All-optical spin switching offers a possible solution, but at present it is limited to a handful of expensive and complex rare-earth ferrimagnets. The spin switching in more abundant ferromagnets may significantly expand the scope of all-optical spin switching. Here by studying 40000 ferromagnetic spins, we show that it is the optical spin-orbit torque that determines the course of spin switching in both ferromagnets and ferrimagnets. Spin switching occurs only if the effective spin angular momentum of each constituent in an alloy exceeds a critical value. Because of the strong exchange coupling, the spin switches much faster in ferromagnets than weakly coupled ferrimagnets. This establishes a paradigm for all-optical spin switching. The resultant magnetic field (65 T) is so big that it will significantly reduce high current in spintronics, thus representing the beginning of photospintronics.

  14. Spinning worlds

    NARCIS (Netherlands)

    Schwarz, H.

    2017-01-01

    The thesis "Spinning Worlds" is about the characterisation of two types of gas-giant exoplanets: Hot Jupiters, with orbital periods of fewer than five days, and young, wide-orbit gas giants, with orbital periods as long as thousands of years. The thesis is based on near-infrared observations of 1

  15. Gate-tunable black phosphorus spin valve with nanosecond spin lifetimes

    Science.gov (United States)

    Avsar, Ahmet; Tan, Jun Y.; Kurpas, Marcin; Gmitra, Martin; Watanabe, Kenji; Taniguchi, Takashi; Fabian, Jaroslav; Özyilmaz, Barbaros

    2017-09-01

    Two-dimensional materials offer new opportunities for both fundamental science and technological applications, by exploiting the electron's spin. Although graphene is very promising for spin communication due to its extraordinary electron mobility, the lack of a bandgap restricts its prospects for semiconducting spin devices such as spin diodes and bipolar spin transistors. The recent emergence of two-dimensional semiconductors could help overcome this basic challenge. In this letter we report an important step towards making two-dimensional semiconductor spin devices. We have fabricated a spin valve based on ultrathin (~5 nm) semiconducting black phosphorus (bP), and established fundamental spin properties of this spin channel material, which supports all electrical spin injection, transport, precession and detection up to room temperature. In the non-local spin valve geometry we measure Hanle spin precession and observe spin relaxation times as high as 4 ns, with spin relaxation lengths exceeding 6 μm. Our experimental results are in a very good agreement with first-principles calculations and demonstrate that the Elliott-Yafet spin relaxation mechanism is dominant. We also show that spin transport in ultrathin bP depends strongly on the charge carrier concentration, and can be manipulated by the electric field effect.

  16. Design of a triple resonance magic angle sample spinning probe for high field solid state nuclear magnetic resonance

    Science.gov (United States)

    Martin, Rachel W.; Paulson, Eric K.; Zilm, Kurt W.

    2003-06-01

    Standard design and construction practices used in building nuclear magnetic resonance (NMR) probes for the study of solid state samples become difficult if not entirely impractical to implement as the 1H resonance frequency approaches the self resonance frequency of commercial capacitors. We describe an approach that utilizes short variable transmission line segments as tunable reactances. Such an approach effectively controls stray reactances and provides a higher Q alternative to ceramic chip capacitors. The particular probe described is built to accommodate a 2.5 mm magic angle spinning rotor system, and is triply tuned to 13C, 15N, and 1H frequencies for use at 18.8 T (200, 80, and 800 MHz, respectively). Isolation of the three radio frequency (rf) channels is achieved using both a rejection trap and a transmission line notch filter. The compact geometry of this design allows three channels with high power handling capability to fit in a medium bore (63 mm) magnet. Extended time variable temperature operation is integral to the mechanical design, enabling the temperature control necessary for investigation of biological macromolecules. Accurate measurement of the air temperature near the sample rotor is achieved using a fiber optic thermometer, which does not interfere with the rf electronics. We also demonstrate that acceptable line shapes are only readily achieved using zero magnetic susceptibility wire in construction of the sample coil. Computer simulation of the circuit aided in the physical design of the probe. Representative data illustrating the efficiency, rf homogeneity, and signal to noise factor of the probe are presented.

  17. New State of Matter: Heavy Fermion Systems, Quantum Spin Liquids, Quasicrystals, Cold Gases, and High-Temperature Superconductors

    Science.gov (United States)

    Shaginyan, V. R.; Stephanovich, V. A.; Msezane, A. Z.; Schuck, P.; Clark, J. W.; Amusia, M. Ya.; Japaridze, G. S.; Popov, K. G.; Kirichenko, E. V.

    2017-12-01

    We report on a new state of matter manifested by strongly correlated Fermi systems including various heavy fermion (HF) metals, two-dimensional quantum liquids such as ^3He films, certain quasicrystals, and systems behaving as quantum spin liquids. Generically, these systems can be viewed as HF systems or HF compounds, in that they exhibit typical behavior of HF metals. At zero temperature, such systems can experience a so-called fermion condensation quantum phase transition (FCQPT). Combining analytical considerations with arguments based entirely on experimental grounds, we argue and demonstrate that the class of HF systems is characterized by universal scaling behavior of their thermodynamic, transport, and relaxation properties. That is, the quantum physics of different HF compounds is found to be universal, emerging irrespective of the individual details of their symmetries, interactions, and microscopic structure. This observed universal behavior reveals the existence of a new state of matter manifest in HF compounds. We propose a simple, realistic model to study the appearance of flat bands in two-dimensional ensembles of ultracold fermionic atoms, interacting with coherent resonant light. It is shown that signatures of these flat bands may be found in peculiarities in their thermodynamic and spectroscopic properties. We also show that the FCQPT, in generating flat bands and altering Fermi surface topology, is an essential progenitor of the exotic behavior of the overdoped high-temperature superconductors represented by La_{2-x}SrxxCuO_4, whose superconductivity differs from that predicted by the classical Bardeen-Cooper-Schrieffer theory. The theoretical results presented are in good agreement with recent experimental observations, closing the colossal gap between these empirical findings and Bardeen-Cooper-Schrieffer-like theories.

  18. New State of Matter: Heavy Fermion Systems, Quantum Spin Liquids, Quasicrystals, Cold Gases, and High-Temperature Superconductors

    Science.gov (United States)

    Shaginyan, V. R.; Stephanovich, V. A.; Msezane, A. Z.; Schuck, P.; Clark, J. W.; Amusia, M. Ya.; Japaridze, G. S.; Popov, K. G.; Kirichenko, E. V.

    2017-08-01

    We report on a new state of matter manifested by strongly correlated Fermi systems including various heavy fermion (HF) metals, two-dimensional quantum liquids such as ^3 He films, certain quasicrystals, and systems behaving as quantum spin liquids. Generically, these systems can be viewed as HF systems or HF compounds, in that they exhibit typical behavior of HF metals. At zero temperature, such systems can experience a so-called fermion condensation quantum phase transition (FCQPT). Combining analytical considerations with arguments based entirely on experimental grounds, we argue and demonstrate that the class of HF systems is characterized by universal scaling behavior of their thermodynamic, transport, and relaxation properties. That is, the quantum physics of different HF compounds is found to be universal, emerging irrespective of the individual details of their symmetries, interactions, and microscopic structure. This observed universal behavior reveals the existence of a new state of matter manifest in HF compounds. We propose a simple, realistic model to study the appearance of flat bands in two-dimensional ensembles of ultracold fermionic atoms, interacting with coherent resonant light. It is shown that signatures of these flat bands may be found in peculiarities in their thermodynamic and spectroscopic properties. We also show that the FCQPT, in generating flat bands and altering Fermi surface topology, is an essential progenitor of the exotic behavior of the overdoped high-temperature superconductors represented by La_{2-x}SrxxCuO_4 , whose superconductivity differs from that predicted by the classical Bardeen-Cooper-Schrieffer theory. The theoretical results presented are in good agreement with recent experimental observations, closing the colossal gap between these empirical findings and Bardeen-Cooper-Schrieffer-like theories.

  19. Architecture and sediment dynamics of the Mauritania Slide Complex

    Energy Technology Data Exchange (ETDEWEB)

    Henrich, Ruediger; Hanebuth, Till J.J.; Krastel, Sebastian [Faculty of Geosciences, University of Bremen, P.O. Box 330440, D-28334 Bremen (Germany); Neubert, Nadja [Faculty of Geosciences, University of Bremen, P.O. Box 330440, D-28334 Bremen (Germany); Institut fuer Geologie, Universitaet Bern, Baltzerstrasse 1-3, Bern (Switzerland); Wynn, Russell B. [National Oceanography Centre, European Way, Southampton, Hampshire, SO14 3ZH (United Kingdom)

    2008-01-15

    Large-scale mass wasting is an important sedimentary process along the northwest African margin, and is related to high sediment accumulation rates under an ocean margin upwelling regime. Although the margin is generally arid with limited fluvial input, additional sediment supply comes from wind-borne Saharan dust. Recent mapping of the margin off Mauritania has revealed a major sediment slide, here called the Mauritania Slide Complex, as it comprises elements of true sliding as well as more mobile distal debris flow. Seismic data image stacked slide deposits separated by undisturbed stratified sediments indicating that undisturbed sediment accumulation was interrupted by several phases of slope failure. A series of stepped headwalls, 25-100 m high, represents the source area of the youngest slide event, which most likely occurred as retrogressive type of failure. The area of seafloor affected by this mass movement is {proportional_to}30,000 km{sup 2}, while the deposit volume is {proportional_to}600 km{sup 3}. The uppermost debrite unit, which has been {sup 14}C dated at 10.5-10.9 ka, forms a broad tongue extending down to the lower slope. This debrite comprises a vertical succession of three different layers of matrix types, with a predominantly outer shelf source at the base and pelagite-dominated composition at the top. The complete sequence of three layers was deposited at a mid slope position, whereas only the upper layers reached the lower slope. A thick pile of sediments with outer shelf/upper slope derived biogenic and terrigenous debris-rich sediments at the base and hemipelagic sediments on top failed at an upper to mid slope location and disintegrated into a layered debris flow on its down-slope journey. (author)

  20. The Earth surface slide movement at Soledad

    Science.gov (United States)

    Moreno, A.

    1986-11-01

    The Earth surface slide movement at Soledad is a mountain-slide type of movement. Estimations of the thickness of the layer which is moving range between 10 and 100 m. There is no proof that the movement is water induced, but it could be influenced by the water household. The slope of the slide area is H: D = 1: 2. The height difference in the moving area studied, according to this paper, is 1 km. The actual rate of movement is about 12 cm/yr.

  1. Ergometer rowing with and without slides

    DEFF Research Database (Denmark)

    Larsen, Anders Holsgaard; Jensen, K

    2010-01-01

    A rowing ergometer can be placed on a slide to imitate 'on-water' rowing. The present study examines I) possible differences in biomechanical and physiological variables of ergometer rowing with and without slides and II) potential consequences on training load during exercise. 7 elite oars......-women rowed in a randomized order in a slide or stationary ergometer at 3 predefined submaximal and at maximal intensity. Oxygen uptake was measured and biomechanical variables of the rowing were calculated based upon handle force (force transducer) and velocity/length (potentiometer) of the stroke. Stroke...

  2. Numerical experiments with rubble piles : equilibrium shapes and spins

    NARCIS (Netherlands)

    Richardson, Derek C.; Elankumaran, Pradeep; Sanderson, Robyn E.

    2005-01-01

    We present numerical experiments investigating the shape and spin limits of self-gravitating "perfect" rubble piles that consist of identical, smooth, rigid, spherical particles with configurable normal coefficient of restitution and no sliding friction. Such constructs are currently employed in a

  3. Spin currents, spin torques, and the concept of spin superfluidity

    OpenAIRE

    Rückriegel, Andreas; Kopietz, Peter

    2017-01-01

    In magnets with non-collinear spin configuration the expectation value of the conventionally defined spin current operator contains a contribution which renormalizes an external magnetic field and hence affects only the precessional motion of the spin polarization. This term, which has been named angular spin current by Sun and Xie [Phys. Rev B 72, 245305 (2005)], does not describe the translational motion of magnetic moments. We give a prescription how to separate these two types of spin tra...

  4. Highly frustrated spin-lattice models of magnetism and their quantum phase transitions: A microscopic treatment via the coupled cluster method

    Science.gov (United States)

    Bishop, R. F.; Li, P. H. Y.; Campbell, C. E.

    2014-10-01

    We outline how the coupled cluster method of microscopic quantum many-body theory can be utilized in practice to give highly accurate results for the ground-state properties of a wide variety of highly frustrated and strongly correlated spin-lattice models of interest in quantum magnetism, including their quantum phase transitions. The method itself is described, and it is shown how it may be implemented in practice to high orders in a systematically improvable hierarchy of (so-called LSUBm) approximations, by the use of computer-algebraic techniques. The method works from the outset in the thermodynamic limit of an infinite lattice at all levels of approximation, and it is shown both how the "raw" LSUBm results are themselves generally excellent in the sense that they converge rapidly, and how they may accurately be extrapolated to the exact limit, m → ∞, of the truncation index m, which denotes the only approximation made. All of this is illustrated via a specific application to a two-dimensional, frustrated, spin-half J1XXZ-J2XXZ model on a honeycomb lattice with nearest-neighbor and next-nearest-neighbor interactions with exchange couplings J1 > 0 and J2 ≡ κJ1 > 0, respectively, where both interactions are of the same anisotropic XXZ type. We show how the method can be used to determine the entire zero-temperature ground-state phase diagram of the model in the range 0 ≤ κ ≤ 1 of the frustration parameter and 0 ≤ Δ ≤ 1 of the spin-space anisotropy parameter. In particular, we identify a candidate quantum spin-liquid region in the phase space.

  5. Evolution of spin and valence states of (Pr0.7Sm0.3)0.7Ca0.3CoO3 at high temperature and high pressure

    Science.gov (United States)

    Chen, J. M.; Lee, J. M.; Haw, S. C.; Chen, S. A.; Hardy, V.; Guillou, F.; Chen, S. W.; Kuo, C. Y.; Pao, C. W.; Lee, J. F.; Hiraoka, N.; Ishii, H.; Tsuei, K. D.; Hu, Z.

    2014-07-01

    The changes of physical properties occurring at a first-order-like transition among a wide family of (Pr1-yLny)1-xCaxCoO3 compounds (Ln being a lanthanide) are controversially discussed as a transition of Co3+ ions from states of low spin (LS) to intermediate spin (IS), or from LS to a mixture of LS and high spin (HS). The debate also includes the nature of the spin state of Co4+, as well as the degree of valence shift between Pr3+ and Pr4+ which accompanies this transition. In the present paper, we investigated the evolution of spin and valence states of Co ions and the valence state of Pr ions in (Pr0.7Sm0.3)0.7Ca0.3CoO3, at high temperature up to 750 K and under pressure up to 36.5 GPa. For this purpose, the data of three spectroscopic techniques were combined: high-resolution Co K-edge partial-fluorescence-yield x-ray absorption spectra, Pr L2-edge x-ray absorption spectra, and Co Kβ x-ray emission spectra. The spectral weight transfer of the pre-edge peaks of the Co K-edge spectra reveals a continuous redistribution of 3d electrons between the t2g and eg levels of Co ions, reflecting a gradual increase of the average Co spin state upon heating. This is further confirmed by Co Kβ x-ray emission spectra, which show an increase of HS Co3+ population when increasing temperature from 300 to 750 K. Applying high pressure at 300 K, the Co Kβ x-ray emission spectra indicate a relatively sharp increase of LS Co3+ population below 4 GPa. Pr L2-edge x-ray absorption spectra of (Pr0.7Sm0.3)0.7Ca0.3CoO3 exhibit a valence-state transition from Pr3+ to Pr3.26+, occurring predominantly upon applying pressure in the range ˜4 to ˜12 GPa. Owing to the charge balance, increasing pressure in this regime induces complex valence and spin-state transitions within the Co ions. Moreover, at high enough pressure, it is found that the Co4+ can also undergo a spin-state transition (from IS to LS), in addition to that affecting the Co3+ (HS to LS).

  6. The First Transverse Single Spin Measurement in High Energy Polarized Proton-Nucleus Collision at the PHENIX experiment at RHIC

    Science.gov (United States)

    Nakagawa, I.

    2016-08-01

    Large single spin asymmetries in very forward neutron production seen using the PHENIX zero-degree calorimeters are a long established feature of transversely polarized proton-proton collisions at RHIC. Neutron production near zero degrees is well described by the one-pion exchange framework. The absorptive correction to the OPE generates the asymmetry as a consequence of a phase shift between the spin flip and non-spin flip amplitudes. However, the amplitude predicted by the OPE is too small to explain the large observed asymmetries. A model introducing interference of pion and a 1-Reggeon exchanges has been successful in reproducing the experimental data. During the RHIC experiment in year 2015, RHIC delivered polarized proton collisions with Au and Al nuclei for the first time, enabling the exploration of the mechanism of transverse single-spin asymmetries with nuclear collisions. The observed asymmetries showed surprisingly strong A-dependence in the inclusive forward neutron production, while the existing framework which was successfull in p+p only predicts moderate A- dependence. Thus the observed data are absolutely unexpected and unpredicted. In this report, experimental and theoretical efforts are discussed to disentangle the observed A-dependence using somewhat semi-inclusive type measurements and Monte-Carlo study, respectively.

  7. SPIN-selling

    CERN Document Server

    Rackham, Neil

    1995-01-01

    True or false? In selling high-value products or services: "closing" increases your chance of success; it is essential to describe the benefits of your product or service to the customer; objection handling is an important skill; and open questions are more effective than closed questions. All false, says Neil Rackham. He and his team studied more than 35,000 sales calls made by 10,000 sales people in 23 countries over 12 years. Their findings revealed that many of the methods developed for selling low-value goods just don't work for major sales. Rackham went on to introduce his SPIN-selling method, where SPIN describes the whole selling process - Situation questions, Problem questions, Implication questions, Need-payoff questions. SPIN-selling provides you with a set of simple and practical techniques which have been tried in many of today's leading companies with dramatic improvements to their sales performance.

  8. Sliding regime of conduction in 'one-dimensional Wigner crystal'

    Energy Technology Data Exchange (ETDEWEB)

    Artemenko, S.N., E-mail: art@cplire.ru [V.A. Kotel' nikov Institute for Radio-engineering and Electronics of Russian Academy of Sciences, Mokhovaya str. 11-7, Moscow 125009 (Russian Federation); Shapiro, D.S.; Vakhitov, R.R.; Remizov, S.V. [V.A. Kotel' nikov Institute for Radio-engineering and Electronics of Russian Academy of Sciences, Mokhovaya str. 11-7, Moscow 125009 (Russian Federation)

    2012-06-01

    We study theoretically transport properties of one-dimensional system of interacting electrons pinned by an impurity. Long-range Coulomb interaction in such a system is known to induce a 4k{sub F} electron density modulation characterized by extremely slow, slower than any power law, decay of the density correlations which can be described as a one-dimensional Wigner crystal. We study non-stationary regime of conduction corresponding to sliding of the 1D Wigner crystal depinned by the applied voltage. In this regime the dc current is accompanied by current oscillations with frequency f=I{sup Macron}/e. We calculate I-V curves and ac current generated by sliding. Our approach is based on the ideas of Luttinger liquid. We study also the case of magnetic impurity and show that applied voltage induces not only the electrical current, but also the spin current as well, in other words, the current becomes spin polarized. We find that a spin bias applied to the system contributes to electric current both in case of magnetic and non-magnetic impurity, and this is related to violation of the spin-charge separation at the impurity site.

  9. Using a modified standard microscope to generate virtual slides.

    Science.gov (United States)

    Romer, David J; Yearsley, Kurtis H; Ayers, Leona W

    2003-05-01

    A standard microscope was reconfigured as a virtual slide generator by adding a Prior Scientific H101 robotic stage with H29 controller and 0.1 microm linear scales and a Hitachi HV-C20 3CCD camera. Media Cybernetics Image Pro Plus version 4 (IP4) software controlled stage movement in the X-, Y-, and Z-axis, whereas a Media Cybernetics Pro-Series Capture Kit captured images at 640 x 480 pixels. Stage calibration, scanning algorithms, storage requirements, and viewing modes were standardized. IP4 was used to montage the captured images into a large virtual slide image that was subsequently saved in TIF or JPEG format. Virtual slides were viewed at the workstation using the IP4 viewer as well as Adobe Photoshop and Kodak Imaging. MGI Zoom Server delivered the virtual slides to the Internet, and MicroBrightField's Neuroinformatica viewing software provided a browser-based virtual microscope interface together with labeling tools for annotating virtual slides. The images were served from a Windows 2000 platform with 2 GB RAM, 500 GB of disk storage, and a 1.0 GHz P4 processor. To conserve disk space on the image server, TIF files were converted to the FlashPix (FPX) file format using a compression ratio of 10:1. By using 4x, 10x, 20x, and 40x objectives, very large gigapixel images of tissue whole-mounts and tissue arrays with high quality and morphologic detail are now being generated for teaching, publication, research, and morphometric analysis. Technical details and a demonstration of our system can be found on the Web at http://virtualmicroscope.osu.edu. Copyright 2003 Wiley-Liss, Inc.

  10. The novel sliding mode speed control based on interior permanent magnet synchronous motor

    Science.gov (United States)

    Liu, Jiaxi; Li, Lili; Du, Pengcheng

    2013-01-01

    In order to overcome the effect of the nonlinear load and uncertain motor parameters of PMSM in high performance servo system, a high-order terminal sliding mode control method is proposed for the speed loop design. The sliding mode controller is stable with Lyapunov theory and the adaptive of sliding mode gain is obtained. This approach improves the robustness of system and steady response and eliminates the chattering phenomenon. The simulation and experiment system is built to prove the correctness of this method.

  11. Direct Observation of High-Spin States in Manganese Dimer and Trimer Cations by X-ray Magnetic Circular Dichroism Spectroscopy in an Ion Trap

    CERN Document Server

    Zamudio-Bayer, Vicente; Langenberg, Andreas; Kossick, Martin; Ławicki, Arkadiusz; Terasaki, Akira; von Issendorff, Bernd; Lau, J Tobias

    2015-01-01

    The electronic structure and magnetic moments of free Mn$_2^+$ and Mn$_3^+$ are characterized by $2p$ x-ray absorption and x-ray magnetic circular dichroism spectroscopy in a cryogenic ion trap that is coupled to a synchrotron radiation beamline. Our results show directly that localized magnetic moments of 5 $\\mu_B$ are created by $3d^5 (^6\\mathrm{S})$ states at each ionic core, which are coupled in parallel to form molecular high-spin states via indirect exchange that is mediated in both cases by a delocalized valence electron in a singly-occupied $4s$ derived orbital with an unpaired spin. This leads to total magnetic moments of 11 $\\mu_B$ for Mn$_2^+$ and 16 $\\mu_B$ for Mn$_3^+$, with no contribution of orbital angular momentum.

  12. Presence or absence of order by disorder in a highly frustrated region of the spin-1/2 Ising-Heisenberg model on triangulated Husimi lattices.

    Science.gov (United States)

    Strečka, Jozef; Ekiz, Cesur

    2015-05-01

    The geometrically frustrated spin-1/2 Ising-Heisenberg model on triangulated Husimi lattices is exactly solved by combining the generalized star-triangle transformation with the method of exact recursion relations. The ground-state and finite-temperature phase diagrams are rigorously calculated along with both sublattice magnetizations of the Ising and Heisenberg spins. It is evidenced that the Ising-Heisenberg model on triangulated Husimi lattices with two or three interconnected triangles-in-triangles units displays in a highly frustrated region a quantum disorder irrespective of temperature, whereas the same model on triangulated Husimi lattices with a greater connectivity of triangles-in-triangles units exhibits at low enough temperatures an outstanding quantum order due to the order-by-disorder mechanism. The quantum reduction of both sublattice magnetizations in the peculiar quantum ordered state gradually diminishes upon increasing the coordination number of the underlying Husimi lattice.

  13. Study of octupole-deformed K=1/2 bands in sup 2 sup 2 sup 7 Th High spin states

    CERN Document Server

    Hammond, N

    2002-01-01

    High spin states in sup 2 sup 2 sup 7 Th have been populated using the reaction sup 2 sup 2 sup 6 Ra(alpha,3n) sup 2 sup 2 sup 7 Th at a bombarding energy of 33 MeV. The high-spin rotational structures of this nucleus have been refined and extended. In addition, the linking of these structures with the low-spin states known from sup 2 sup 3 sup 1 U alpha decay has allowed a comprehensive decay scheme of this nucleus to be assembled for the first time. Four previously known rotational bands are interpreted as Coriolis-coupled K suppi = 1/2 sup + and K suppi = 1/2 sup - bands, in agreement with predictions using a reflection-asymmetric mean-field approach. The determination of decoupling parameters for these bands is consistent with the a(K suppi = 1/2 sup +) = -a(K suppi = 1/2 sup -) rigid-octupole-rotor expectation. A further rotational band is interpreted as having K suppi = 3/ sup - . Measured D sub 0 /Q sub 0 ratios are consistent with an interpolation, of the values given for neighbouring even-even nuclei...

  14. Dynamic TCP acknowledgment with sliding window

    National Research Council Canada - National Science Library

    Koga, Hisashi

    .... However, its framework does not consider the sliding window in the TCP protocol that restricts the maximum number of packets that the sender can inject into the network without an acknowledgement...

  15. SlideJ: An ImageJ plugin for automated processing of whole slide images.

    Directory of Open Access Journals (Sweden)

    Vincenzo Della Mea

    Full Text Available The digital slide, or Whole Slide Image, is a digital image, acquired with specific scanners, that represents a complete tissue sample or cytological specimen at microscopic level. While Whole Slide image analysis is recognized among the most interesting opportunities, the typical size of such images-up to Gpixels- can be very demanding in terms of memory requirements. Thus, while algorithms and tools for processing and analysis of single microscopic field images are available, Whole Slide images size makes the direct use of such tools prohibitive or impossible. In this work a plugin for ImageJ, named SlideJ, is proposed with the objective to seamlessly extend the application of image analysis algorithms implemented in ImageJ for single microscopic field images to a whole digital slide analysis. The plugin has been complemented by examples of macro in the ImageJ scripting language to demonstrate its use in concrete situations.

  16. Non magnetic neutron spin quantum precession using multilayer spin splitter and a phase-spin echo interferometer

    Energy Technology Data Exchange (ETDEWEB)

    Ebisawa, T.; Tasaki, S.; Kawai, T.; Akiyoshi, T. [Kyoto Univ., Kumatori, Osaka (Japan). Research Reactor Inst.; Achiwa, N.; Hino, M.; Otake, Y.; Funahashi, H.

    1996-08-01

    The authors have developed cold neutron optics and interferometry using multilayer mirrors. The advantages of the multilayer mirrors are their applicability to long wavelength neutrons and a great variety of the mirror performance. The idea of the present spin interferometry is based on nonmagnetic neutron spin quantum precession using multilayer spin splitters. The equation for polarized neutrons means that the polarized neutrons are equivalent to the coherent superposition of two parallel spin eigenstates. The structure and principle of a multilayer spin splitter are explained, and the nonmagnetic gap layer of the multilayer spin splitter gives rise to neutron spin quantum precession. The performance test of the multilayer spin splitter were made with a new spin interferometer, which is analogous optically to a spin echo system with vertical precession field. The spin interferometers were installed at Kyoto University research reactor and the JRR-3. The testing method and the results are reported. The performance tests on a new phase-spin echo interferometer are described, and its applications to the development of a high resolution spin echo system and a Jamin type cold neutron interferometer are proposed. (K.I.)

  17. Transverse dipole spin modes in quantum dots

    Science.gov (United States)

    Lipparini, E.; Barranco, M.; Emperador, A.; Pi, M.; Serra, Ll.

    1999-09-01

    We have carried out a systematic analysis of the transverse dipole spin response of a large-size quantum dot within time-dependent current density functional theory. Results for magnetic fields corresponding to integer filling factors are reported, as well as a comparison with the longitudinal dipole spin response. As in the two-dimensional electron gas, the spin response at high-spin magnetization is dominated by a low-energy transverse mode.

  18. On the Correctness of Sliding Window Protocols

    OpenAIRE

    van de Snepscheut, Jan L.A.

    1991-01-01

    In this note some struggles with the sliding window protocol and the special case known as the alternating bit protocol, are reported. We try to give a correctness proof, and discover that we cannot do so for one of the versions of the sliding window protocol. One may either require channels that satisfy stronger assumptions or, as we will do, adapt the protocol and stick to the weaker assumptions. The alternating bit protocol can be traced back to [Bartlett]. We have been unab...

  19. Tribology of the lubricant quantized sliding state.

    Science.gov (United States)

    Castelli, Ivano Eligio; Capozza, Rosario; Vanossi, Andrea; Santoro, Giuseppe E; Manini, Nicola; Tosatti, Erio

    2009-11-07

    In the framework of Langevin dynamics, we demonstrate clear evidence of the peculiar quantized sliding state, previously found in a simple one-dimensional boundary lubricated model [A. Vanossi et al., Phys. Rev. Lett. 97, 056101 (2006)], for a substantially less idealized two-dimensional description of a confined multilayer solid lubricant under shear. This dynamical state, marked by a nontrivial "quantized" ratio of the averaged lubricant center-of-mass velocity to the externally imposed sliding speed, is recovered, and shown to be robust against the effects of thermal fluctuations, quenched disorder in the confining substrates, and over a wide range of loading forces. The lubricant softness, setting the width of the propagating solitonic structures, is found to play a major role in promoting in-registry commensurate regions beneficial to this quantized sliding. By evaluating the force instantaneously exerted on the top plate, we find that this quantized sliding represents a dynamical "pinned" state, characterized by significantly low values of the kinetic friction. While the quantized sliding occurs due to solitons being driven gently, the transition to ordinary unpinned sliding regimes can involve lubricant melting due to large shear-induced Joule heating, for example at large speed.

  20. spin coating

    African Journals Online (AJOL)

    PROJET SOJA

    Intense UV photoluminescence is observed for intrinsic ZnO film. Keywords : thin films, oxidize zinc doped aluminium (ZnO:Al), sol-gel, spin coating, structural analysis, electric and optical properties. 1. Introduction. Depuis ces vingt dernières années les couches minces d'oxyde de zinc ont connu un intérêt croissant dans ...

  1. Research of the Quality of Quarry Dumpers Engine Crankshafts Sliding Bearings of Various Manufacturers

    National Research Council Canada - National Science Library

    Korotkov Alexander; Korotkova Lidiya; Vidin Denis

    2017-01-01

    Sliding bearings are an important part of many large and critical components. They are widely used in power equipment, high-capacity pumps, compressors, electric motors and internal combustion engines (ICE...

  2. Efficient thermal spin injection in metallic nanostructures

    Science.gov (United States)

    Nomura, Tatsuya; Ariki, Taisei; Hu, Shaojie; Kimura, Takashi

    2017-11-01

    Thermal spin injection is a unique and fascinating method for generating spin current. If magnetization can be controlled by thermal spin injection, various advantages will be provided in spintronic devices, through its wireless controllability. However, the generation efficiency of thermal spin injection is believed to be lower than that of electrical spin injection. Here, we explore a suitable ferromagnetic metal for an efficient thermal spin injection, via systematic experiments based on diffusive spin transport under temperature gradients. Since a ferromagnetic metal with strong spin splitting is expected to have a large spin-dependent Seebeck coefficient, a lateral spin valve based on CoFe electrodes has been fabricated. However, the superior thermal spin injection property has not been observed, because the CoFe electrode retained its crystalline signature—where s-like electrons dominate the transport property in the ferromagnet. To suppress the crystalline signature, we adopt a CoFeAl electrode, in which the Al impurity significantly reduces the contribution from s-like electrons. Highly efficient thermal spin injection has been demonstrated using this CoFeAl electrode. Further optimization for thermal spin injection has been demonstrated by adjusting the Co and Fe composition.

  3. Geometric spin echo under zero field

    Science.gov (United States)

    Sekiguchi, Yuhei; Komura, Yusuke; Mishima, Shota; Tanaka, Touta; Niikura, Naeko; Kosaka, Hideo

    2016-05-01

    Spin echo is a fundamental tool for quantum registers and biomedical imaging. It is believed that a strong magnetic field is needed for the spin echo to provide long memory and high resolution, since a degenerate spin cannot be controlled or addressed under a zero magnetic field. While a degenerate spin is never subject to dynamic control, it is still subject to geometric control. Here we show the spin echo of a degenerate spin subsystem, which is geometrically controlled via a mediating state split by the crystal field, in a nitrogen vacancy centre in diamond. The demonstration reveals that the degenerate spin is protected by inherent symmetry breaking called zero-field splitting. The geometric spin echo under zero field provides an ideal way to maintain the coherence without any dynamics, thus opening the way to pseudo-static quantum random access memory and non-invasive biosensors.

  4. Super-spinning compact objects and models of high-frequency quasi-periodic oscillations observed in Galactic microquasars. II. Forced resonances

    Science.gov (United States)

    Kotrlová, A.; Šrámková, E.; Török, G.; Stuchlík, Z.; Goluchová, K.

    2017-11-01

    In our previous work (Paper I) we applied several models of high-frequency quasi-periodic oscillations (HF QPOs) to estimate the spin of the central compact object in three Galactic microquasars assuming the possibility that the central compact body is a super-spinning object (or a naked singularity) with external spacetime described by Kerr geometry with a dimensionless spin parameter a ≡ cJ/GM2 > 1. Here we extend our consideration, and in a consistent way investigate implications of a set of ten resonance models so far discussed only in the context of a five of these models that involve Keplerian and radial epicyclic oscillations we find the existence of a unique specific QPO excitation radius. Consequently, there is a simple behaviour of dimensionless frequency M × νU(a) represented by a single continuous function having solely one maximum close to a ≳ 1. Only one of these models is compatible with the expectation of a ≳ 1. The other five models that involve the radial and vertical epicyclic oscillations imply the existence of multiple resonant radii. This signifies a more complicated behaviour of M × νU(a) that cannot be represented by single functions. Each of these five models is compatible with the expectation of a ≳ 1.

  5. High-spin transition quadrupole moments in neutron-rich Mo and Ru nuclei: Testing γ softness?

    Energy Technology Data Exchange (ETDEWEB)

    Snyder, J.B. [Physics Department, Washington University, St. Louis, MO 63130 (United States); Reviol, W., E-mail: reviol@wustl.edu [Chemistry Department, Washington University, St. Louis, MO 63130 (United States); Sarantites, D.G. [Chemistry Department, Washington University, St. Louis, MO 63130 (United States); Afanasjev, A.V. [Department of Physics and Astronomy, Mississippi State University, Starkville, MS 39762 (United States); Janssens, R.V.F. [Physics Division, Argonne National Laboratory, Argonne, IL 60439 (United States); Abusara, H. [Department of Physics, Faculty of Science, An-Najah National University, Nablus, Palestine (Country Unknown); Carpenter, M.P. [Physics Division, Argonne National Laboratory, Argonne, IL 60439 (United States); Chen, X. [Chemistry Department, Washington University, St. Louis, MO 63130 (United States); Chiara, C.J. [Physics Division, Argonne National Laboratory, Argonne, IL 60439 (United States); Department of Chemistry and Biochemistry, University of Maryland, College Park, MD 20742 (United States); Greene, J.P.; Lauritsen, T. [Physics Division, Argonne National Laboratory, Argonne, IL 60439 (United States); McCutchan, E.A. [Physics Division, Argonne National Laboratory, Argonne, IL 60439 (United States); National Nuclear Data Center, Brookhaven National Laboratory, Upton, NY 11973 (United States); Seweryniak, D.; Zhu, S. [Physics Division, Argonne National Laboratory, Argonne, IL 60439 (United States)

    2013-06-10

    The transition quadrupole moments, Q{sub t}, of rotational bands in the neutron-rich, even-mass {sup 102–108}Mo and {sup 108–112}Ru nuclei were measured in the 8–16 ℏ spin range with the Doppler-shift attenuation method. The nuclei were populated as fission fragments from {sup 252}Cf fission. The detector setup consisted of the Gammasphere spectrometer and the HERCULES fast-plastic array. At moderate spin, the Q{sub t} moments are found to be reduced with respect to the values near the ground states. Attempts to describe the observations in mean-field-based models, specifically cranked relativistic Hartree–Bogoliubov theory, illustrate the challenge theory faces and the difficulty to infer information on γ softness and triaxiality from the data.

  6. Robust excitation control design using sliding-mode technique for multimachine power systems

    Energy Technology Data Exchange (ETDEWEB)

    Colbia-Vega, A.; de Leon-Morales, J.; Salas-Pena, O.; Mata-Jimenez, M.T. [Mechanical and Electrical Engineering Faculty, Autonomous University of Nuevo Leon, Cd. Universitaria, 66450 San Nicolas de los Garza, N.L. (Mexico); Fridman, L. [Department of Control, Division of Electrical Engineering Faculty, National Autonomous University of Mexico, Cd. Universitaria, 04510 Mexico, D.F. (Mexico)

    2008-09-15

    An output feedback controller is proposed to enhance the transient stability of nonlinear multimachine power systems considered as a classical model with flux decay dynamics. Combining high-order sliding-mode techniques with a robust high-order sliding-mode differentiator, a robust decentralized controller is obtained. Numerical results are presented to illustrate the performance of the proposed control scheme and its robustness properties. (author)

  7. The Reloca Slide offshore Central Chile (35.5°S) - a Revision Based on Geotechnical Sliding Plane Characterization and Tsunami Modeling

    Science.gov (United States)

    Voelker, D.; Kopf, A.; Ikari, M.; Trütner, S.

    2015-12-01

    Reloca Slide is a submarine failure of ~ 24 km3 volume at the lower slope of the continental margin of Central Chile. The sliding event appears to be of post-Last Glacial Maximum (LGM) age. The evacuation site exhibits a 30° steep and 2000 m high failure plane, the slide deposits in the Chile Trench are preserved as scattered 10-600 m high angular blocks incorporated in a ~60 m high debris fan. The combination of a steep and high failure surface (high velocity) and the apparent cohesiveness of the displaced material (little disintegration) makes Reloca Slide a likely source for a local tsunami. Our numerical simulations show that a comparable event at the lower slope would generate waves of > 8 m offshore amplitude that would impact the Chilean coast within ~25 minutes. Reloca Slide is unique along the Central Chilean margin by its size and particular morphology. Yet, much of the unfailed lower slope along a ~1500 km long stretch shares general morphology, tectonic situation and sedimentary properties with the Reloca Slide source region. It is therefore of high relevance for risk mitigation to understand preconditioning factors and triggering mechanisms of as critical boundary conditions for similar potential future events. Core samples were taken directly from the failure plane, oedometer tests indicate a former burial depth of ~ 500 m. Samples are used to run geotechnical experiments for an improved understanding of the mechanics of the failure process. We are particularly interested in the question of whether the failure of the lowermost slope is a continuing process linked to the subduction of the Nazca Plate (e.g. a process needed to re-establish a critically tapered accretionary wedge), or, alternatively, if it is related to particular local conditions or an exceptional triggering event. We report on results from direct and rotary shear experiments to characterize frictional properties and strength of the materials at the detachment surface of the slide.

  8. Black Hole Spin Measurement Uncertainty

    Science.gov (United States)

    Salvesen, Greg; Begelman, Mitchell C.

    2018-01-01

    Angular momentum, or spin, is one of only two fundamental properties of astrophysical black holes, and measuring its value has numerous applications. For instance, obtaining reliable spin measurements could constrain the growth history of supermassive black holes and reveal whether relativistic jets are powered by tapping into the black hole spin reservoir. The two well-established techniques for measuring black hole spin can both be applied to X-ray binaries, but are in disagreement for cases of non-maximal spin. This discrepancy must be resolved if either technique is to be deemed robust. We show that the technique based on disc continuum fitting is sensitive to uncertainties regarding the disc atmosphere, which are observationally unconstrained. By incorporating reasonable uncertainties into black hole spin probability density functions, we demonstrate that the spin measured by disc continuum fitting can become highly uncertain. Future work toward understanding how the observed disc continuum is altered by atmospheric physics, particularly magnetic fields, will further strengthen black hole spin measurement techniques.

  9. slide positivity rate of malaria among patients attending two ...

    African Journals Online (AJOL)

    DR. AMINU

    ABSTRACT. Slide positivity rate of malaria among patients attending two hospitals in Kano metropolis was investigated during the wet season using four hundred blood films. A slide positvity rate of 250. (62.5%) was recorded with 117 (64.63) from slides of male patients and 133(60.70%) from slides of female patients ...

  10. Robust Sliding Mode Control of Permanent Magnet Synchronous Generator-Based Wind Energy Conversion Systems

    Directory of Open Access Journals (Sweden)

    Guangping Zhuo

    2016-12-01

    Full Text Available The subject of this paper pertains to sliding mode control and its application in nonlinear electrical power systems as seen in wind energy conversion systems. Due to the robustness in dealing with unmodeled system dynamics, sliding mode control has been widely used in electrical power system applications. This paper presents first and high order sliding mode control schemes for permanent magnet synchronous generator-based wind energy conversion systems. The application of these methods for control using dynamic models of the d-axis and q-axis currents, as well as those of the high speed shaft rotational speed show a high level of efficiency in power extraction from a varying wind resource. Computer simulation results have shown the efficacy of the proposed sliding mode control approaches.

  11. The friction and wear of ceramic/ceramic and ceramic/metal combinations in sliding contact

    Energy Technology Data Exchange (ETDEWEB)

    Sliney, H.E.; Dellacorte, C. (NASA Lewis Research Center, Cleveland, OH (United States))

    1994-07-01

    The tribological characteristics of ceramics sliding on ceramics are compared to those of ceramics sliding on a nickel-based turbine alloy. The friction and wear of oxide ceramics and silicon-based ceramics in air at temperatures from room ambient to 900 C (in a few cases to 1200 C) were measured for a hemispherically-tipped pin on a flat sliding contact geometry. In general, especially at high temperature, friction and wear were lower for ceramic/metal combinations than for ceramic/ceramic combinations. The better tribological performance for ceramic/metal combinations is attributed primarily to the lubricious nature of the oxidized surface of the metal.

  12. Sliding mode pulse-width modulation technique for direct torque controlled induction motor drive

    Science.gov (United States)

    Bounadja, M.; Belarbi, A. W.; Belmadani, B.

    2010-05-01

    This paper presents a novel pulse-width modulation technique based sliding mode approach for direct torque control of an induction machine drive. Methodology begins with a sliding mode control of machine's torque and stator flux to generate the reference voltage vector and to reduce parameters sensitivity. Then, the switching control of the three-phase inverter is developed using sliding mode concept to make the system tracking reference voltage inputs. The main features of the proposed methodologies are the high tracking accuracy and the much easier implementation compared to the space vector modulation. Simulations are carried out to confirm the effectiveness of proposed control algorithms.

  13. Sliding droplets on superomniphobic zinc oxide nanostructures.

    Science.gov (United States)

    Perry, Guillaume; Coffinier, Yannick; Thomy, Vincent; Boukherroub, Rabah

    2012-01-10

    This study reports on liquid-repellency of zinc oxide nanostructures (ZnO NS). The ZnO NS are synthesized by an easy and fast chemical bath deposition technique. Three different nanostructured surfaces consisting of nanorods, flowers, and particles are prepared, depending on the deposition time and the presence of ethanolamine in the reaction mixture. Chemical functionalization of the ZnO NS with 1H,1H,2H,2H-perfluorodecyltrichlorosilane (PFTS) in liquid (PFTS L) and vapor phase (PFTS V) or through octafluorobutane (C(4)F(8)) plasma deposition led to the formation of superomniphobic surfaces. A comprehensive characterization of the wetting properties (static contact angle and contact angle hysteresis) has been performed using liquids composed of deionized water and various concentrations of ethanol (surface tension between 35 and 72.6 mN/m). Depending on the nanostructures morphology, coating nature and liquid employed, high static apparent contact angles θ ≈ 150-160°, and low contact angle hysteresis Δθ ≈ 0° are obtained. The different ZnO NS are characterized using scanning electron microscopy (SEM) and contact angle measurements. The results reported in this work permit preparation of sliding omniphobic surfaces using a simple and low cost technique.

  14. Spin currents, spin torques, and the concept of spin superfluidity

    Science.gov (United States)

    Rückriegel, Andreas; Kopietz, Peter

    2017-03-01

    In magnets with noncollinear spin configuration the expectation value of the conventionally defined spin current operator contains a contribution which renormalizes an external magnetic field and hence affects only the precessional motion of the spin polarization. This term, which has been named angular spin current by Sun and Xie [Phys. Rev. B 72, 245305 (2005)], 10.1103/PhysRevB.72.245305, does not describe the translational motion of magnetic moments. We give a prescription for how to separate these two types of spin transport and show that the translational movement of the spin is always polarized along the direction of the local magnetization. We also show that at vanishing temperature the classical magnetic order parameter in magnetic insulators cannot carry a translational spin current and elucidate how this affects the interpretation of spin supercurrents.

  15. Spin-torque switching of a nano-magnet using giant spin hall effect

    Directory of Open Access Journals (Sweden)

    Ashish V. Penumatcha

    2015-10-01

    Full Text Available The Giant Spin Hall Effect(GSHE in metals with high spin-orbit coupling is an efficient way to convert charge currents to spin currents, making it well-suited for writing information into magnets in non-volatile magnetic memory as well as spin-logic devices. We demonstrate the switching of an in-plane CoFeB magnet using a combination of GSHE and an external magnetic field. The magnetic field dependence of the critical current is used to estimate the spin hall angle with the help of a thermal activation model for spin-transfer torque switching of a nanomagnet.

  16. Application of whole slide image markup and annotation for pathologist knowledge capture

    Directory of Open Access Journals (Sweden)

    Walter S Campbell

    2013-01-01

    Full Text Available Objective: The ability to transfer image markup and annotation data from one scanned image of a slide to a newly acquired image of the same slide within a single vendor platform was investigated. The goal was to study the ability to use image markup and annotation data files as a mechanism to capture and retain pathologist knowledge without retaining the entire whole slide image (WSI file. Methods: Accepted mathematical principles were investigated as a method to overcome variations in scans of the same glass slide and to accurately associate image markup and annotation data across different WSI of the same glass slide. Trilateration was used to link fixed points within the image and slide to the placement of markups and annotations of the image in a metadata file. Results: Variation in markup and annotation placement between WSI of the same glass slide was reduced from over 80 μ to less than 4 μ in the x-axis and from 17 μ to 6 μ in the y-axis ( P < 0.025. Conclusion: This methodology allows for the creation of a highly reproducible image library of histopathology images and interpretations for educational and research use.

  17. Application of whole slide image markup and annotation for pathologist knowledge capture.

    Science.gov (United States)

    Campbell, Walter S; Foster, Kirk W; Hinrichs, Steven H

    2013-01-01

    The ability to transfer image markup and annotation data from one scanned image of a slide to a newly acquired image of the same slide within a single vendor platform was investigated. The goal was to study the ability to use image markup and annotation data files as a mechanism to capture and retain pathologist knowledge without retaining the entire whole slide image (WSI) file. Accepted mathematical principles were investigated as a method to overcome variations in scans of the same glass slide and to accurately associate image markup and annotation data across different WSI of the same glass slide. Trilateration was used to link fixed points within the image and slide to the placement of markups and annotations of the image in a metadata file. Variation in markup and annotation placement between WSI of the same glass slide was reduced from over 80 μ to less than 4 μ in the x-axis and from 17 μ to 6 μ in the y-axis (P < 0.025). This methodology allows for the creation of a highly reproducible image library of histopathology images and interpretations for educational and research use.

  18. spin coating

    African Journals Online (AJOL)

    PROJET SOJA

    Dans ce travail nous avons préparé des couches minces de l'oxyde de zinc ZnO dopées à l'aluminium et non dopées par la technique Sol-Gel associée au « spin coating » sur des substrats en verre « pyrex » à partir de l'acétate de zinc dissous dans une solution de l'éthanol. Nous avons ensuite effectué des analyses ...

  19. Anomaly Detection in Test Equipment via Sliding Mode Observers

    Science.gov (United States)

    Solano, Wanda M.; Drakunov, Sergey V.

    2012-01-01

    Nonlinear observers were originally developed based on the ideas of variable structure control, and for the purpose of detecting disturbances in complex systems. In this anomaly detection application, these observers were designed for estimating the distributed state of fluid flow in a pipe described by a class of advection equations. The observer algorithm uses collected data in a piping system to estimate the distributed system state (pressure and velocity along a pipe containing liquid gas propellant flow) using only boundary measurements. These estimates are then used to further estimate and localize possible anomalies such as leaks or foreign objects, and instrumentation metering problems such as incorrect flow meter orifice plate size. The observer algorithm has the following parts: a mathematical model of the fluid flow, observer control algorithm, and an anomaly identification algorithm. The main functional operation of the algorithm is in creating the sliding mode in the observer system implemented as software. Once the sliding mode starts in the system, the equivalent value of the discontinuous function in sliding mode can be obtained by filtering out the high-frequency chattering component. In control theory, "observers" are dynamic algorithms for the online estimation of the current state of a dynamic system by measurements of an output of the system. Classical linear observers can provide optimal estimates of a system state in case of uncertainty modeled by white noise. For nonlinear cases, the theory of nonlinear observers has been developed and its success is mainly due to the sliding mode approach. Using the mathematical theory of variable structure systems with sliding modes, the observer algorithm is designed in such a way that it steers the output of the model to the output of the system obtained via a variety of sensors, in spite of possible mismatches between the assumed model and actual system. The unique properties of sliding mode control

  20. Virtual slides in peer reviewed, open access medical publication

    Directory of Open Access Journals (Sweden)

    Kayser Klaus

    2011-12-01

    article. The acceptance of VS by the reader is high as well as by the authors. Of specific value are the increased confidence to and reputation of authors as well as the presented information to the reader. Additional associated functions such as access to author-owned related image collections, reader-controlled automated image measurements and image transformations are in preparation. Virtual Slides The virtual slide(s for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1232133347629819.