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Sample records for light ions present

  1. Index of light ion inertial confinement fusion publications and presentations January 1989 through December 1993

    Energy Technology Data Exchange (ETDEWEB)

    Sweeney, M.A. [ed.

    1995-11-01

    This report lists publications and presentations that are related to inertial confinement fusion and were authored or coauthored by Sandians in the Pulsed Power Sciences Center from 1989 through 1993. The 661 publications and presentations are categorized into the following general topics: (1) reviews, (2) ion sources, (3) ion diodes, (4) plasma opening switches, (5) ion beam transport, (6) targets and deposition physics, (7) advanced driver and pulsed power technology development, (8) diagnostics, and (9) code development. Research in these areas is arranged by topic in chronological order, with the early efforts under each topic presented first. The work is also categorized alphabetically by first author. A list of acronyms, abbreviations, and definitions of use in understanding light ion inertial confinement fusion research is also included.

  2. Ions and light

    CERN Document Server

    Bowers, Michael T

    2013-01-01

    Gas Phase Ion Chemistry, Volume 3: Ions and Light discusses how ions are formed by electron impact, ion-molecule reactions, or electrical discharge. This book discusses the use of light emitted by excited molecules to characterize either the chemistry that formed the excited ion, the structure of the excited ion, or both.Organized into 10 chapters, this volume begins with an overview of the extension of the classical flowing afterglow technique to include infrared and chemiluminescence and laser-induced fluorescence detection. This text then examines the experiments involving molecules that ar

  3. Intercomparatives study of the detection characteristics of the CR-39 SSNTD for light ions: Present status of the Besancon-Dresden approaches

    CERN Document Server

    Brun, C; Jouffroy, M; Meyer, P; Groetz, J E; Abel, F; Chambaudet, A; Dörschel, B; Hermsdorf, D; Bretschneider, R; Kadner, K; Kuehne, H

    1999-01-01

    For the last few years, the Besancon and Dresden teams have been working in a parallel way on light ion (protons and alphas) registration characteristics for the CR-39 SSNTD. Even if the two groups use different approaches, the main part of both investigations concerns the study of the track etch rate (V sub T) and the consequences of the obtained results, which have provided us with greater understanding of detection limits. After recalling the methods used to determine the V sub T from both teams, we will show how fundamental data related to the registration properties of the CR-39 detector can be extracted. Indeed, the knowledge of an analytical relation for the V sub T enables the relationship between this velocity and the primary deposited energy to be examined with respect to the same spatial variable (the instantaneous depth of penetration (x) of the incoming particle). According to experimental uncertainties, the Bragg peak of the primary ionization coincides within a very close range with the maximum...

  4. Preparation of Light Ions for LHC and SPS Physics (S-LightIon Project)

    CERN Document Server

    Manglunki, D

    2011-01-01

    Now that ions are available for collisions in the LHC, several experiments have expressed interest in fixed-target heavy and light ions in the North Area of the SPS. Taking into account the demands of the LHC and other scheduling constraints, this document details the various possibilities for planning fixed target ion runs in the coming years, and the resources needed to achieve them.

  5. A Device Model for Polymer Light-Emitting Diodes with Mobile Ions

    NARCIS (Netherlands)

    Jong, M.J.M. de; Blom, P.W.M.

    1996-01-01

    A model is presented for the device operation of a polymer light-emitting diode (PLED) with mobile ions. It is calculated that the low efficiency of a PLED with a high injection barrier increases as the ions migrate.

  6. Optical cavity integrated surface ion trap for enhanced light collection

    Science.gov (United States)

    Benito, Francisco M.

    Ion trap systems allow the faithful storage and manipulation of qubits encoded in the energy levels of the ions, and can be interfaced with photonic qubits that can be transmitted to connect remote quantum systems. Single photons transmitted from two remote sites, each entangled with one quantum memory, can be used to entangle distant quantum memories by interfering on a beam splitter. Efficient remote entanglement generation relies upon efficient light collection from single ions into a single mode fiber. This can be realized by integrating an ion trap with an optical cavity and employing the Purcell effect for enhancing the light collection. Remote entanglement can be used as a resource for a quantum repeater for provably secure long-distance communication or as a method for communicating within a distributed quantum information processor. We present the integration of a 1 mm optical cavity with a micro-fabricated surface ion trap. The plano-concave cavity is oriented normal to the chip surface where the planar mirror is attached underneath the trap chip. The cavity is locked using a 780 nm laser which is stabilized to Rubidium and shifted to match the 369 nm Doppler transition in Ytterbium. The linear ion trap allows ions to be shuttled in and out of the cavity mode. The Purcell enhancement of spontaneous emission into the cavity mode would then allow efficient collection of the emitted photons, enabling faster remote entanglement generation.

  7. Hybrid ion, atom and light trap

    CERN Document Server

    Jyothi, S; Ram, N Bhargava; Rangwala, S A

    2013-01-01

    We present an unique experimental arrangement which permits the simultaneous trapping and cooling of ions and neutral atoms, within a Fabry-Perot (FP) cavity. The versatility of this hybrid trap experiment enables a variety of studies with trapped mixtures. The motivations behind the production of such a hybrid trap system are explained, followed by details of how the experiment is put together. Several experiments that have been performed with this system are presented and some opportunities with this system are discussed. However the primary emphasis is focussed on the aspects that pertain to the trapped ions, in this hybrid system.

  8. Synchronized ion acceleration by ultraintense slow light

    CERN Document Server

    Brantov, A V; Kovalev, V F; Bychenkov, V Yu

    2015-01-01

    An effective scheme of synchronized laser-triggered ion acceleration and the corresponding theoretical model are proposed for a slow light pulse of relativistic intensity, which penetrates into a near-critical-density plasma, strongly slows, and then increases its group velocity during propagation within a target. The 3D PIC simulations confirm this concept for proton acceleration by a femtosecond petawatt-class laser pulse experiencing relativistic self-focusing, quantify the characteristics of the generated protons, and demonstrate a significant increase of their energy compared with the proton energy generated from optimized ultrathin solid dense foils.

  9. Overview of Light-Ion Beam Therapy

    Energy Technology Data Exchange (ETDEWEB)

    Chu, William T.

    2006-03-16

    In 1930, Ernest Orlando Lawrence at the University of California at Berkeley invented the cyclotron. One of his students, M. Stanley Livingston, constructed a 13-cm diameter model that had all the features of early cyclotrons, accelerating protons to 80 keV using less than 1 kV on a semi-circular accelerating electrode, now called the ''dee''. Soon after, Lawrence constructed the first two-dee 27-Inch (69-cm) Cyclotron, which produced protons and deuterons of 4.8 MeV. In 1939, Lawrence constructed the 60-Inch (150-cm) Cyclotron, which accelerated deuterons to 19 MeV. Just before WWII, Lawrence designed a 184-inch cyclotron, but the war prevented the building of this machine. Immediately after the war ended, the Veksler-McMillan principle of phase stability was put forward, which enabled the transformation of conventional cyclotrons to successful synchrocyclotrons. When completed, the 184-Inch Synchrocyclotron produced 340-MeV protons. Following it, more modern synchrocyclotrons were built around the globe, and the synchrocyclotrons in Berkeley and Uppsala, together with the Harvard cyclotron, would perform pioneering work in treatment of human cancer using accelerated hadrons (protons and light ions). When the 184-Inch Synchrocyclotron was built, Lawrence asked Robert Wilson, one of his former graduate students, to look into the shielding requirements for of the new accelerator. Wilson soon realized that the 184-Inch would produce a copious number of protons and other light ions that had enough energy to penetrate human body, and could be used for treatment of deep-seated diseases. Realizing the advantages of delivering a larger dose in the Bragg peak when placed inside deep-seated tumors, he published in a medical journal a seminal paper on the rationale to use accelerated protons and light ions for treatment of human cancer. The precise dose localization provided by protons and light ions means lower doses to normal tissues adjacent to the

  10. Nonelastic nuclear reactions induced by light ions with the BRIEFF code

    CERN Document Server

    Duarte, H

    2010-01-01

    The intranuclear cascade (INC) code BRIC has been extended to compute nonelastic reactions induced by light ions on target nuclei. In our approach the nucleons of the incident light ion move freely inside the mean potential of the ion in its center-of-mass frame while the center-of-mass of the ion obeys to equations of motion dependant on the mean nuclear+Coulomb potential of the target nucleus. After transformation of the positions and momenta of the nucleons of the ion into the target nucleus frame, the collision term between the nucleons of the target and of the ion is computed taking into account the partial or total breakup of the ion. For reactions induced by low binding energy systems like deuteron, the Coulomb breakup of the ion at the surface of the target nucleus is an important feature. Preliminary results of nucleon production in light ion induced reactions are presented and discussed.

  11. Measuring perfusion with light (Conference Presentation)

    Science.gov (United States)

    Jansen, Sanne M. A.; de Bruin, Daniel M.; Faber, Dirk J.; van Leeuwen, Ton G.

    2016-03-01

    There is no gold standard test for perfusion evaluation in surgery. Optical Imaging techniques are able to image tissue at high resolution and in real-time. Laser Speckle Contrast Imaging, Optical Coherence Tomography, Sidestream Darkfield and Incident Darkfield all use the interaction of light with tissue to create an image. To test their feasibility and explore validity in a controlled setting, we created a phantom with the optical properties of tissue and microvascular channels of 30-400 micrometer. With a Hamilton Syringe Pump we mimicked blood flow velocities of 0-20 mm/sec. Images of all different modalities at different blood flow velocities were compared in terms of imaging depth, resoluation and hemodynamic parameters.

  12. A study of light ion accelerators for cancer treatment

    Energy Technology Data Exchange (ETDEWEB)

    Prelec, K.

    1997-07-01

    This review addresses several issues, such as possible advantages of light ion therapy compared to protons and conventional radiation, the complexity of such a system and its possible adaptation to a hospital environment, and the question of cost-effectiveness compared to other modalities for cancer treatment or to other life saving procedures. Characteristics and effects of different types of radiation on cells and organisms will be briefly described; this will include conventional radiation, protons and light ions. The status of proton and light ion cancer therapy will then be described, with more emphasis on the latter; on the basis of existing experience the criteria for the use of light ions will be listed and areas of possible medical applications suggested. Requirements and parameters of ion beams for cancer treatment will then be defined, including ion species, energy and intensity, as well as parameters of the beam when delivered to the target (scanning, time structure, energy spread). Possible accelerator designs for light ions will be considered, including linear accelerators, cyclotrons and synchrotrons and their basic features given; this will be followed by a review of existing and planned facilities for light ions. On the basis of these considerations a tentative design for a dedicated light ion facility will be suggested, a facility that would be hospital based, satisfying the clinical requirements, simple to operate and reliable, concluding with its cost-effectiveness in comparison with other modalities for treatment of cancer.

  13. Light ion components of the galactic cosmic rays: nuclear interactions and transport theory.

    Science.gov (United States)

    Cucinotta, F A; Townsend, L W; Wilson, J W; Shinn, J L; Badhwar, G D; Dubey, R R

    1996-01-01

    Light nuclei are present in the primary galactic cosmic rays (GCR) and are produced in thick targets due to projectile or target fragmentation from both nucleon and heavy ion induced reactions. In the primary GCR, 4He is the most abundant nucleus after 1H. However, there are also a substantial fluxes of 2H and 3He. In this paper we describe theoretical models based on quantum multiple scattering theory for the description of light ion nuclear interactions. The energy dependence of the light ion fragmentation cross section is considered with comparisons of inclusive yields and secondary momentum distributions to experiments described. We also analyze the importance of a fast component of lights ions from proton and neutron induced target fragmentation. These theoretical models have been incorporated into the cosmic ray transport code HZETRN and will be used to analyze the role of shielding materials in modulating the production and the energy spectrum of light ions.

  14. Light-ion production on silicon and electronics reliability

    Energy Technology Data Exchange (ETDEWEB)

    Tippawan, U. [Dept. of Neutron Research, Uppsala Univ. (Sweden); Tippawan, U.; Pomp, S.; Atac, A. [Dept. of Neutron Research, Uppsala Univ. (Sweden); Bergenwall, B.; Blomgren, J.; Hildebrand, A.; Johansson, C.; Klug, J.; Mermod, P.; Oesterlund, M.; Elmgren, K.; Olsson, N.; Jonsson, O.; Nilsson, L.; Prokofiev, A.V.; Renberg, P.U.; Nadel-Turonski, P.; Dangtip, S.; Corcalciuc, V.; Watanabe, Y.; Koning, A.

    2003-07-01

    Cosmic-ray neutrons create a reliability problem in modern electronics. A neutron can cause a nuclear reaction inside or near a chip, thus releasing free charge, which in turn could, e.g., flip the memory content or change the result of a logical operation. The magnitude of this problem is expected to increase in the near future. For assessment of the problem, and for identifying possible solutions to it, improved knowledge of the underlying nuclear physics is of major importance. New data on light-ion production on silicon at 96 MeV, acquired with the MEDLEY setup at TSL uppsala, are presented and compared with recent models. (orig.)

  15. Cyclotron resonance effects on stochastic acceleration of light ionospheric ions

    Science.gov (United States)

    Singh, N.; Schunk, R. W.; Sojka, J. J.

    1982-01-01

    The production of energetic ions with conical pitch angle distributions along the auroral field lines is a subject of considerable current interest. There are several theoretical treatments showing the acceleration (heating) of the ions by ion cyclotron waves. The quasi-linear theory predicts no acceleration when the ions are nonresonant. In the present investigation, it is demonstrated that the cyclotron resonances are not crucial for the transverse acceleration of ions by ion cyclotron waves. It is found that transverse energization of ionospheric ions, such as He(+), He(++), O(++), and O(+), is possible by an Electrostatic Hydrogen Cyclotron (EHC) wave even in the absence of cyclotron resonance. The mechanism of acceleration is the nonresonant stochastic heating. However, when there are resonant ions both the total energy gain and the number of accelerated ions increase with increasing parallel wave number.

  16. Photochronographic registration of fast light ions

    Science.gov (United States)

    Litvin, Dmitri N.; Lazarchuk, Valeri P.; Murugov, Vasili M.; Petrov, Sergei I.; Senik, Alexei V.

    1999-06-01

    A possibility of registration of fast ions (protons, alpha- particles) with the help of an X-ray streak camera is demonstrated. The spatial resolution of the device is 50 micrometer, the physical time resolution with the use of a CsJ-cathode is 7 ps. From (alpha) -emission a secondary electrons yield is determined of (eta) equals 8 el../part. The device sensitivity makes it possible to register separate (alpha) -particles and protons. On the basis of the device there have been elaborated techniques of spatial-spectral registering of radiation of fast ions emitted by laser thermonuclear targets. The techniques are destined to study processes of interaction of high-intensive laser radiation with an appliance Iskra-5 target.

  17. Temperature response of several scintillator materials to light ions

    Science.gov (United States)

    Rodríguez-Ramos, M.; Jiménez-Ramos, M. C.; García-Muñoz, M.; García López, J.

    2017-07-01

    Ion beam induced luminescence has been used to study the response of scintillator screens of Y2O3:Eu3+ (P56) and SrGa2S4:Eu2+ (TG-Green) when irradiated with light ions (protons, deuterium and helium particles). The absolute efficiency of the samples has been studied as a function of the ion energy (with energies up to 3.5 MeV), the beam current and the operating temperature. The evolution of the scintillator yield with ion fluence has been carried out for all the scintillators to estimate radiation damage. Finally, measurements of the decay time of these materials using a system of pulsed beam accelerated particles have been done. Among the screens under study, the TG-Green is the best suited material, in terms of absolute efficiency, temporal response and degradation with ion dose, for fast-ion loss detectors in fusion devices.

  18. Light nuclei production in heavy ion collisions

    CERN Document Server

    Khan, K H; Wazir, Z; Khan, E U; Haseeb, Mahnaz Q; Ajaz, M

    2009-01-01

    Light nuclei production as a result of nuclear coalescence effect can give some signals on final state of Quark Gluon Plasma formation. We are studying the behavior of nuclear modification factor as a function of different variables using the simulated data coming from the FASTMC generator. This data is necessary to extract information on coalescence mechanism from experimental data on high energy nuclear-nuclear interactions.

  19. Evidence of light guiding in ion-implanted diamond

    CERN Document Server

    Lagomarsino, S; Bosia, F; Vannoni, M; Calusi, S; Giuntini, L; Massi, M

    2016-01-01

    We demonstrate the feasibility of fabricating light-waveguiding microstructures in bulk single-crystal diamond by means of direct ion implantation with a scanning microbeam, resulting in the modulation of the refractive index of the ion-beam damaged crystal. Direct evidence of waveguiding through such buried microchannels is obtained with a phase-shift micro-interferometric method allowing the study of the multi-modal structure of the propagating electromagnetic field. The possibility of defining optical and photonic structures by direct ion writing opens a range of new possibilities in the design of quantum-optical devices in bulk single crystal diamond.

  20. Solar hydrogen: harvesting light and heat from sun (Presentation Recording)

    Science.gov (United States)

    Guo, Liejin; Jing, Dengwei

    2015-09-01

    My research group in the State Key Laboratory of Multiphase Flow in Power Engineering (SKLMF), Xi'an Jiaotong University has been focusing on renewable energy, especially solar hydrogen, for about 20 years. In this presentation, I will present the most recent progress in our group on solar hydrogen production using light and heat. Firstly, "cheap" photoelectrochemical and photocatalytic water splitting, including both nanostructured materials and pilot-scale demonstration in our group for light-driven solar hydrogen (artificial photosynthesis) will be introduced. Then I will make a deep introduction to the achievements on the thermal-driven solar hydrogen, i.e., biomass/coal gasification in supercritical water for large-scale and low-cost hydrogen production using concentrated solar light.

  1. Light ion production for a future radiobiological facility at CERN: preliminary studies.

    Science.gov (United States)

    Stafford-Haworth, Joshua; Bellodi, Giulia; Küchler, Detlef; Lombardi, Alessandra; Röhrich, Jörg; Scrivens, Richard

    2014-02-01

    Recent medical applications of ions such as carbon and helium have proved extremely effective for the treatment of human patients. However, before now a comprehensive study of the effects of different light ions on organic targets has not been completed. There is a strong desire for a dedicated facility which can produce ions in the range of protons to neon in order to perform this study. This paper will present the proposal and preliminary investigations into the production of light ions, and the development of a radiobiological research facility at CERN. The aims of this project will be presented along with the modifications required to the existing linear accelerator (Linac3), and the foreseen facility, including the requirements for an ion source in terms of some of the specification parameters and the flexibility of operation for different ion types. Preliminary results from beam transport simulations will be presented, in addition to some planned tests required to produce some of the required light ions (lithium, boron) to be conducted in collaboration with the Helmholtz-Zentrum für Materialien und Energie, Berlin.

  2. A detection system for energetic light heavy ions

    NARCIS (Netherlands)

    Engelen, C.P.M. van; Jelmersma, R.; Brink, A. van den; Kamermans, R.

    1984-01-01

    A light heavy ion detection system which consists of a gas-filled ionization chamber (IC) connected to a scattering chamber via a time-of-flight (TOF) system has been constructed. The entrance window of the IC has an area of 14 × 40 cm2, the active depth is 115 cm. Filled with CF4 at a pressure of 3

  3. Role of ions in the regulation of light-harvesting

    Directory of Open Access Journals (Sweden)

    Radek Kana

    2016-12-01

    Full Text Available Regulation of photosynthetic light harvesting in the thylakoids is one of the major key factors affecting the efficiency of photosynthesis. Thylakoid membrane is negatively charged and influences both the structure and the function of the primarily photosynthetic reactions through its electrical double layer. Further, there is a heterogeneous organization of soluble ions (K+, Mg2+, Cl- attached to the thylakoid membrane that, together with fixed charges (negatively charged amino acids, lipids, provides an electrical field. The electrical double layer is affected by the valence of the ions and interferes with the regulation of state transitions, protein interactions, and excitation energy spillover from Photosystem II to Photosystem I. These effects are reflected in changes in the intensity of chlorophyll a fluorescence, which is also a measure of photoprotective non-photochemical quenching of the excited state of chlorophyll a. A triggering of non-photochemical quenching proceeds via lumen acidification and is coupled to the export of positive counter-ions (Mg2+, K+ to the stroma or/and negative ions (e.g., Cl- into the lumen. The effect of protons and anions in the lumen and of the cations (Mg2+, K+ in the stroma are, thus, functionally tightly interconnected. In this review, we discuss the consequences of the model of electrical double layer, proposed by James Barber (J. Barber (1980 Biochim Biophys Acta 594:253-308 in light of light-harvesting regulation. Further, we explain differences between electrostatic screening and neutralization, and we emphasize the opposite effect of monovalent (K+ and divalent (Mg2+ ions on light-harvesting and on screening of the negative charges on the thylakoid membrane; this effect needs to be incorporated in all future models of photosynthetic regulation by ion channels and transporters.

  4. Characterizing Ion Profiles in Dynamic Junction Light-Emitting Electrochemical Cells

    Energy Technology Data Exchange (ETDEWEB)

    Shoji, Tyko D.; Zhu, Zihua; Leger, Janelle M.

    2013-11-27

    Organic semiconductors have the unique ability to conduct both ionic and electronic charge carriers in thin films, an emerging advantage in applications such as light-emitting devices, transistors, and electrochromic devices, among others. Evidence suggests that the profiles of ions and electrochemical doping in the polymer film during operation significantly impact the performance and stability of the device. However, few studies have directly characterized ion profiles within LECs. Here, we present profiles of ion distributions in LECs following application of voltage, via time-of-flight secondary ion mass spectrometry. Ion distributions were characterized with regard to film thickness, salt concentration, applied voltage, and relaxation over time. Results provide insight into the correlation between ion profiles and device performance, as well as potential approaches to tuning electrochemical doping processes in LECs.

  5. Predictive Models of Li-ion Battery Lifetime (Presentation)

    Energy Technology Data Exchange (ETDEWEB)

    Smith, K.; Wood, E.; Santhanagopalan, S.; Kim, G.; Shi, Y.; Pesaran, A.

    2014-09-01

    Predictive models of Li-ion battery reliability must consider a multiplicity of electrochemical, thermal and mechanical degradation modes experienced by batteries in application environments. Complicating matters, Li-ion batteries can experience several path dependent degradation trajectories dependent on storage and cycling history of the application environment. Rates of degradation are controlled by factors such as temperature history, electrochemical operating window, and charge/discharge rate. Lacking accurate models and tests, lifetime uncertainty must be absorbed by overdesign and warranty costs. Degradation models are needed that predict lifetime more accurately and with less test data. Models should also provide engineering feedback for next generation battery designs. This presentation reviews both multi-dimensional physical models and simpler, lumped surrogate models of battery electrochemical and mechanical degradation. Models are compared with cell- and pack-level aging data from commercial Li-ion chemistries. The analysis elucidates the relative importance of electrochemical and mechanical stress-induced degradation mechanisms in real-world operating environments. Opportunities for extending the lifetime of commercial battery systems are explored.

  6. Pionic fusion in light-ion systems

    Energy Technology Data Exchange (ETDEWEB)

    Joulaeizadeh, L., E-mail: l.joulaeizadeh@tudelft.n [KVI, University of Groningen, Groningen (Netherlands); Gasparic, I. [Rudjer Boskovic Institute, Zagreb (Croatia); Amir-Ahmadi, H.R.; Bacelar, J. [KVI, University of Groningen, Groningen (Netherlands); Caplar, R. [Rudjer Boskovic Institute, Zagreb (Croatia); Eslami-Kalantari, M.; Kalantar-Nayestanaki, N.; Loehner, H.; Mardanpour, H.; Messchendorp, J.G.; Moeini, H.; Ramazani-Moghaddam-Arani, A.; Shende, S.V. [KVI, University of Groningen, Groningen (Netherlands); Stephan, E. [Institute of Physics, University of Silesia, Katowice (Poland)

    2011-01-03

    The role of pions in the nuclear interaction has been studied in pionic fusion experiments using the AGOR accelerator facility at KVI. Pionic fusion is a highly coherent process in which two nuclei fuse to a united nucleus and the available centre-of-mass (C.M.) energy is emitted through the pion channel. The examined reactions were {sup 4}He({sup 3}He, {pi}{sup 0}){sup 7}Be and {sup 6}Li({sup 4}He, {pi}{sup 0}){sup 10}B{sup *} and both reactions were performed at C.M. energies about 10 MeV above the coherent pion production threshold. Here, the experimental results for the {sup 6}Li({sup 4}He, {pi}{sup 0}){sup 10}B{sup *} reaction will be presented and discussed. In order to provide sensitivity to the full dynamics and relevant processes involved in the pionic fusion reaction, almost the full angular distribution of neutral pions has been determined. In a phenomenological analysis, the contributions of Legendre polynomials to reproduce the behaviour of the angular distribution have been studied. The results of this analysis confirm the importance of the clustering correlations for the {sup 6}Li({sup 4}He, {pi}{sup 0}){sup 10}B{sup *} reaction. The mass dependence of the pionic fusion reaction is in agreement with the results of the existing models extrapolated to this reaction.

  7. Pionic fusion in light-ion systems

    Science.gov (United States)

    Joulaeizadeh, L.; Gašparić, I.; Amir-Ahmadi, H. R.; Bacelar, J.; Čaplar, R.; Eslami-Kalantari, M.; Kalantar-Nayestanaki, N.; Löhner, H.; Mardanpour, H.; Messchendorp, J. G.; Moeini, H.; Ramazani-Moghaddam-Arani, A.; Shende, S. V.; Stephan, E.

    2011-01-01

    The role of pions in the nuclear interaction has been studied in pionic fusion experiments using the AGOR accelerator facility at KVI. Pionic fusion is a highly coherent process in which two nuclei fuse to a united nucleus and the available centre-of-mass (C.M.) energy is emitted through the pion channel. The examined reactions were 4He(3He, π0)7Be and 6Li(4He, π0)10B* and both reactions were performed at C.M. energies about 10 MeV above the coherent pion production threshold. Here, the experimental results for the 6Li(4He, π0)10B* reaction will be presented and discussed. In order to provide sensitivity to the full dynamics and relevant processes involved in the pionic fusion reaction, almost the full angular distribution of neutral pions has been determined. In a phenomenological analysis, the contributions of Legendre polynomials to reproduce the behaviour of the angular distribution have been studied. The results of this analysis confirm the importance of the clustering correlations for the 6Li(4He, π0)10B* reaction. The mass dependence of the pionic fusion reaction is in agreement with the results of the existing models extrapolated to this reaction.

  8. Wearable light management system for light stimulated healing of large area chronic wounds (Conference Presentation)

    Science.gov (United States)

    Kallweit, David; Mayer, Jan; Fricke, Sören; Schnieper, Marc; Ferrini, Rolando

    2016-03-01

    Chronic wounds represent a significant burden to patients, health care professionals, and health care systems, affecting over 40 million patients and creating costs of approximately 40 billion € annually. We will present a medical device for photo-stimulated wound care based on a wearable large area flexible and disposable light management system consisting of a waveguide with incorporated micro- and nanometer scale optical structures for efficient light in-coupling, waveguiding and homogeneous illumination of large area wounds. The working principle of this innovative device is based on the therapeutic effects of visible light to facilitate the self-healing process of chronic wounds. On the one hand, light exposure in the red (656nm) induces growth of keratinocytes and fibroblasts in deeper layers of the skin. On the other hand, blue light (453nm) is known to have antibacterial effects predominately at the surface layers of the skin. In order to be compliant with medical requirements the system will consist of two elements: a disposable wound dressing with embedded flexible optical waveguides for the light management and illumination of the wound area, and a non-disposable compact module containing the light sources, a controller, a rechargeable battery, and a data transmission unit. In particular, we will report on the developed light management system. Finally, as a proof-of-concept, a demonstrator will be presented and its performances will be reported to demonstrate the potential of this innovative device.

  9. Measuring Light Air Ions in a Speleotherapeutic Cave

    Science.gov (United States)

    Roubal, Z.; Bartušek, K.; Szabó, Z.; Drexler, P.; Überhuberová, J.

    2017-02-01

    The paper deals with a methodology proposed for measuring the concentration of air ions in the environment of speleotherapeutic caves, and with the implementation of the AK-UTEE-v2 ionmeter. Speleotherapy, in the context of its general definition, is the medical therapy that utilizes the climate of selected caves to treat patients with health problems such as asthma. These spaces are characterized by the presence of high air humidity and they make extreme demands on the execution of the measuring device, the Gerdien tube (GT in the following) in particular, and on the amplifier electronics. The result is an automated measuring system using a GT with low-volume air flow, enabling long-term measuring of air ion concentration and determination of spectral ion characteristics. Interesting from the instrumentation viewpoint are the GT design, active shielding, and execution of the electrometric amplifier. A specific method for the calculation of spectral ion characteristics and the mode of automatic calibration were proposed and a procedure of automatic measurement in the absence of attendants was set up. The measuring system is designed for studying and long-term monitoring of the concentration of light negative ions in dependence on climatic conditions and on the mobility of ions occurring in the cave.

  10. Using neutral beams as a light ion beam probe (invited)

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Xi, E-mail: chenxi@fusion.gat.com [Oak Ridge Institute for Science and Education, Oak Ridge, Tennessee 37831 (United States); Heidbrink, W. W. [University of California Irvine, Irvine, California 92697 (United States); Van Zeeland, M. A.; Pace, D. C.; Petty, C. C.; Fisher, R. K. [General Atomics, P.O. Box 85608, San Diego, California 92186-5608 (United States); Kramer, G. J.; Nazikian, R. [Princeton Plasma Physics Laboratory, P.O. Box 451, Princeton, New Jersey 08543 (United States); Austin, M. E. [University of Texas at Austin, Austin, Texas 78712 (United States); Hanson, J. M. [Columbia University, New York, New York 10027 (United States); Zeng, L. [University of California Los Angeles, Los Angeles, California 90095 (United States)

    2014-11-15

    By arranging the particle first banana orbits to pass near a distant detector, the light ion beam probe (LIBP) utilizes orbital deflection to probe internal fields and field fluctuations. The LIBP technique takes advantage of (1) the in situ, known source of fast ions created by beam-injected neutral particles that naturally ionize near the plasma edge and (2) various commonly available diagnostics as its detector. These born trapped particles can traverse the plasma core on their inner banana leg before returning to the plasma edge. Orbital displacements (the forces on fast ions) caused by internal instabilities or edge perturbing fields appear as modulated signal at an edge detector. Adjustments in the q-profile and plasma shape that determine the first orbit, as well as the relative position of the source and detector, enable studies under a wide variety of plasma conditions. This diagnostic technique can be used to probe the impact on fast ions of various instabilities, e.g., Alfvén eigenmodes (AEs) and neoclassical tearing modes, and of externally imposed 3D fields, e.g., magnetic perturbations. To date, displacements by AEs and by externally applied resonant magnetic perturbation fields have been measured using a fast ion loss detector. Comparisons with simulations are shown. In addition, nonlinear interactions between fast ions and independent AE waves are revealed by this technique.

  11. ENLIGHT: The European Network for Light Ion Hadron Therapy.

    Science.gov (United States)

    Dosanjh, Manjit; Cirilli, Manuela; Greco, Virginia; Meijer, Annelie E

    2012-11-01

    The European Network for Light Ion Hadron Therapy (ENLIGHT) was established in 2002 to coordinate European efforts on hadron therapy (radiotherapy performed with protons and light ions instead of high-energy photons). The ENLIGHT network is formed by the European Hadron Therapy Community, with more than 300 participants from 20 different countries. A major success of ENLIGHT has been uniting traditionally separate communities so that clinicians, physicists, biologists, and engineers with experience and interest in particle therapy work together. ENLIGHT has been a successful initiative in forming a common European platform and bringing together people from diverse disciplines. ENLIGHT demonstrates the advantages of regular and organized exchanges of data, information, and best practices, as well as determining and following strategies for future needs in research and technological development in the hadron therapy field.

  12. Light ion irradiation for unfavorable soft tissue sarcoma

    Energy Technology Data Exchange (ETDEWEB)

    Linstadt, D.; Castro, J.R.; Phillips, T.L.; Petti, P.L.; Collier, J.M.; Daftari, I.; Schoethaler, R.; Rayner, A.

    1990-09-01

    Between 1978 and 1989, 32 patients with unfavorable soft tissue sarcoma underwent light ion (helium, neon) irradiation with curative intent at Lawrence Berkeley Laboratory. The tumors were located in the trunk in 22 patients and head and neck in 10. Macroscopic tumor was present in 22 at the time of irradiation. Two patients had tumors apparently induced by previous therapeutic irradiation. Follow-up times for surviving patients ranged from 4 to 121 months (median 27 months). The overall 3-year actuarial local control rate was 62%; the corresponding survival rate was 50%. The 3-year actuarial control rate for patients irradiated with macroscopic tumors was 48%, while none of the patients with microscopic disease developed local recurrence (100%). The corresponding 3-year actuarial survival rates were 40% (macroscopic) and 78% (microscopic). Patients with retroperitoneal sarcoma did notably well; the local control rate and survival rate were 64% and 62%, respectively. Complications were acceptable; there were no radiation related deaths, while two patients (6%) required operations to correct significant radiation-related injuries. These results appear promising compared to those achieved by low -LET irradiation, and suggest that this technique merits further investigation.

  13. Selected List of Low Energy Beam Transport Facilities for Light-Ion, High-Intensity Accelerators

    Energy Technology Data Exchange (ETDEWEB)

    Prost, L. R. [Fermi National Accelerator Laboratory (FNAL), Batavia, IL (United States)

    2016-02-17

    This paper presents a list of Low Energy Beam Transport (LEBT) facilities for light-ion, high-intensity accelerators. It was put together to facilitate comparisons with the PXIE LEBT design choices. A short discussion regarding the importance of the beam perveance in the choice of the transport scheme follows.

  14. Stomatal Blue Light Response Is Present in Early Vascular Plants.

    Science.gov (United States)

    Doi, Michio; Kitagawa, Yuki; Shimazaki, Ken-ichiro

    2015-10-01

    Light is a major environmental factor required for stomatal opening. Blue light (BL) induces stomatal opening in higher plants as a signal under the photosynthetic active radiation. The stomatal BL response is not present in the fern species of Polypodiopsida. The acquisition of a stomatal BL response might provide competitive advantages in both the uptake of CO2 and prevention of water loss with the ability to rapidly open and close stomata. We surveyed the stomatal opening in response to strong red light (RL) and weak BL under the RL with gas exchange technique in a diverse selection of plant species from euphyllophytes, including spermatophytes and monilophytes, to lycophytes. We showed the presence of RL-induced stomatal opening in most of these species and found that the BL responses operated in all euphyllophytes except Polypodiopsida. We also confirmed that the stomatal opening in lycophytes, the early vascular plants, is driven by plasma membrane proton-translocating adenosine triphosphatase and K(+) accumulation in guard cells, which is the same mechanism operating in stomata of angiosperms. These results suggest that the early vascular plants respond to both RL and BL and actively regulate stomatal aperture. We also found three plant species that absolutely require BL for both stomatal opening and photosynthetic CO2 fixation, including a gymnosperm, C. revoluta, and the ferns Equisetum hyemale and Psilotum nudum.

  15. Advanced light ion source extraction system for a new electron cyclotron resonance ion source geometry at Saclay.

    Science.gov (United States)

    Delferrière, O; Gobin, R; Harrault, F; Nyckees, S; Sauce, Y; Tuske, O

    2012-02-01

    One of the main goal of intense light ion injector projects such as IPHI, IFMIF, or SPIRAL2, is to produce high current beams while keeping transverse emittance as low as possible. To prevent emittance growth induced in a dual solenoid low energy transfer line, its length has to be minimized. This can be performed with the advanced light ion source extraction system concept that we are developing: a new ECR 2.45 GHz type ion source based on the use of an additional low energy beam transport (LEBT) short length solenoid close to the extraction aperture to create the resonance in the plasma chamber. The geometry of the source has been considerably modified to allow easy maintenance of each component and to save space in front of the extraction. The source aims to be very flexible and to be able to extract high current ion beams at energy up to 100 kV. A specific experimental setup for this source is under installation on the BETSI test bench, to compare its performances with sources developed up to now in the laboratory, such as SILHI, IFMIF, or SPIRAL2 ECR sources. This original extraction source concept is presented, as well as electromagnetic simulations with OPERA-2D code. Ion beam extraction in space charge compensation regime with AXCEL, and beam dynamics simulation with SOLMAXP codes show the beam quality improvement at the end of the LEBT.

  16. Advanced light ion source extraction system for a new electron cyclotron resonance ion source geometry at Saclaya)

    Science.gov (United States)

    Delferrière, O.; Gobin, R.; Harrault, F.; Nyckees, S.; Sauce, Y.; Tuske, O.

    2012-02-01

    One of the main goal of intense light ion injector projects such as IPHI, IFMIF, or SPIRAL2, is to produce high current beams while keeping transverse emittance as low as possible. To prevent emittance growth induced in a dual solenoid low energy transfer line, its length has to be minimized. This can be performed with the advanced light ion source extraction system concept that we are developing: a new ECR 2.45 GHz type ion source based on the use of an additional low energy beam transport (LEBT) short length solenoid close to the extraction aperture to create the resonance in the plasma chamber. The geometry of the source has been considerably modified to allow easy maintenance of each component and to save space in front of the extraction. The source aims to be very flexible and to be able to extract high current ion beams at energy up to 100 kV. A specific experimental setup for this source is under installation on the BETSI test bench, to compare its performances with sources developed up to now in the laboratory, such as SILHI, IFMIF, or SPIRAL2 ECR sources. This original extraction source concept is presented, as well as electromagnetic simulations with OPERA-2D code. Ion beam extraction in space charge compensation regime with AXCEL, and beam dynamics simulation with SOLMAXP codes show the beam quality improvement at the end of the LEBT.

  17. Trapped-ion probing of light-induced charging effects on dielectrics

    Energy Technology Data Exchange (ETDEWEB)

    Harlander, M; Brownnutt, M; Haensel, W; Blatt, R, E-mail: max.harlander@uibk.ac.a [Institut fuer Experimentalphysik, Universitaet Innsbruck, Technikerstrasse 25, A-6020 Innsbruck (Austria)

    2010-09-15

    We use a string of confined {sup 40}Ca{sup +} ions to measure perturbations to a trapping potential which are caused by the light-induced charging of an antireflection-coated window and of insulating patches on the ion-trap electrodes. The electric fields induced at the ions' position are characterized as a function of distance to the dielectric and as a function of the incident optical power and wavelength. The measurement of the ion-string position is sensitive to as few as 40 elementary charges per {radical}(Hz) on the dielectric at distances of the order of millimetres, and perturbations are observed for illuminations with light of wavelengths as large as 729 nm. This has important implications for the future of miniaturized ion-trap experiments, notably with regard to the choice of electrode material and the optics that must be integrated in the vicinity of the ion. The method presented here can be readily applied to the investigation of charging effects beyond the context of ion-trap experiments.

  18. LIGHT - from laser ion acceleration to future applications

    Science.gov (United States)

    Roth, Markus; Light Collaboration

    2013-10-01

    Creation of high intensity multi-MeV ion bunches by high power lasers became a reliable tool during the last 15 years. The laser plasma source provides for TV/m accelerating field gradients and initially sub-ps bunch lengths. However, the large envelope divergence and the continuous exponential energy spectrum are substential drawbacks for many possible applications. To face this problem, the LIGHT collaboration was founded (Laser Ion Generation, Handling and Transport). The collaboration consists of several university groups and research centers, namely TU Darmstadt, JWGU Frankfurt, HI Jena, HZDR Dresden and GSI Darmstadt. The central goal is building a test beamline for merging laser ion acceleration with conventional accelerator infrastructure at the GSI facility. In the latest experiments, low divergent proton bunches with a central energy of up to 10 MeV and containing >109 particles could be provided at up to 2.2 m behind the plasma source, using a pulsed solenoid. In a next step, a radiofrequency cavity will be added to the beamline for phase rotation of these bunches, giving access to sub-ns bunch lengths and reaching highest intensities. An overview of the LIGHT objectives and the recent experimental results will be given. This work was supported by HIC4FAIR.

  19. Two-gluon correlations in heavy-light ion collisions

    Science.gov (United States)

    Wertepny, Douglas E.

    2014-11-01

    We derive the cross-section for two-gluon production in heavy-light ion collisions in the saturation/Color Glass Condensate framework. This calculation includes saturation effects to all orders in one of the nuclei (heavy ion) along with a single saturation correction in the projectile (light ion). The calculation of the correlation function predicts (qualitatively) two identical ridge-like correlations, near- and away-side. This prediction was later supported by experimental findings in p + A collisions at the LHC. Concentrating on the energy and geometry dependence of the correlation functions we find that the correlation function is nearly center-of-mass energy independent. The geometry dependence of the correlation function leads to an enhancement of near- and away-side correlations for the tip-on-tip U + U collisions when compared with side-on-side U + U collisions, an exactly opposite behavior from the correlations generated by the elliptic flow of the quark-gluon plasma.

  20. Two-gluon correlations in heavy–light ion collisions

    Energy Technology Data Exchange (ETDEWEB)

    Wertepny, Douglas E., E-mail: wertepny.1@osu.edu

    2014-11-15

    We derive the cross-section for two-gluon production in heavy–light ion collisions in the saturation/Color Glass Condensate framework. This calculation includes saturation effects to all orders in one of the nuclei (heavy ion) along with a single saturation correction in the projectile (light ion). The calculation of the correlation function predicts (qualitatively) two identical ridge-like correlations, near- and away-side. This prediction was later supported by experimental findings in p + A collisions at the LHC. Concentrating on the energy and geometry dependence of the correlation functions we find that the correlation function is nearly center-of-mass energy independent. The geometry dependence of the correlation function leads to an enhancement of near- and away-side correlations for the tip-on-tip U + U collisions when compared with side-on-side U + U collisions, an exactly opposite behavior from the correlations generated by the elliptic flow of the quark–gluon plasma.

  1. Two-Particle Correlations in Heavy-Light Ion Collisions

    CERN Document Server

    Wertepny, Douglas E

    2016-01-01

    We study the initial, high-energy scatterings in heavy ion collisions using the saturation/Color Glass Condensate framework. We focus on two-particle long-range rapidity correlations which are modeled as two-gluon correlations. We calculate the two-gluon production cross section using the saturation framework in the heavy-light ion regime, including all-order saturation effects in the heavy nucleus while considering only two-orders in the light ion. The two-gluon production cross section generates four types of long-range in rapidity correlations: (i) geometric correlations, (ii) Hanbury Brown and Twiss (HBT) like correlations accompanied by a back-to-back maximum, (iii) near-side correlations, and (iv) away-side azimuthal correlations. The geometric correlations (i) are due to the fact that nucleons are correlated by simply being confined within the same nucleus. Correlations (iii) and (iv) have exactly the same amplitudes along with azimuthal and rapidity shapes: one centered around $\\Delta \\phi =0$ and the...

  2. Temporal evolution of helix hydration in a light-gated ion channel correlates with ion conductance.

    Science.gov (United States)

    Lórenz-Fonfría, Víctor A; Bamann, Christian; Resler, Tom; Schlesinger, Ramona; Bamberg, Ernst; Heberle, Joachim

    2015-10-27

    The discovery of channelrhodopsins introduced a new class of light-gated ion channels, which when genetically encoded in host cells resulted in the development of optogenetics. Channelrhodopsin-2 from Chlamydomonas reinhardtii, CrChR2, is the most widely used optogenetic tool in neuroscience. To explore the connection between the gating mechanism and the influx and efflux of water molecules in CrChR2, we have integrated light-induced time-resolved infrared spectroscopy and electrophysiology. Cross-correlation analysis revealed that ion conductance tallies with peptide backbone amide I vibrational changes at 1,665(-) and 1,648(+) cm(-1). These two bands report on the hydration of transmembrane α-helices as concluded from vibrational coupling experiments. Lifetime distribution analysis shows that water influx proceeded in two temporally separated steps with time constants of 10 μs (30%) and 200 μs (70%), the latter phase concurrent with the start of ion conductance. Water efflux and the cessation of the ion conductance are synchronized as well, with a time constant of 10 ms. The temporal correlation between ion conductance and hydration of helices holds for fast (E123T) and slow (D156E) variants of CrChR2, strengthening its functional significance.

  3. The LILIA (laser induced light ions acceleration) experiment at LNF

    Energy Technology Data Exchange (ETDEWEB)

    Agosteo, S. [Energy Department, Polytechnic of Milan and INFN, Milan (Italy); Anania, M.P. [INFN LNF Frascati, Frascati (Italy); Caresana, M. [Energy Department, Polytechnic of Milan and INFN, Milan (Italy); Cirrone, G.A.P. [INFN LNS Catania, Catania (Italy); De Martinis, C. [Physics Department, University of Milan and INFN, Milan (Italy); Delle Side, D. [LEAS, University of Salento and INFN, Lecce (Italy); Fazzi, A. [Energy Department, Polytechnic of Milan and INFN, Milan (Italy); Gatti, G. [INFN LNF Frascati, Frascati (Italy); Giove, D. [Physics Department, University of Milan and INFN, Milan (Italy); Giulietti, D. [Physics Department, University of Pisa and INFN, Pisa (Italy); Gizzi, L.A.; Labate, L. [INO-CNR and INFN, Pisa (Italy); Londrillo, P. [Physics Department, University of Bologna and INFN, Bologna (Italy); Maggiore, M. [INFN LNL, Legnaro (Italy); Nassisi, V., E-mail: vincenzo.nassisi@le.infn.it [LEAS, University of Salento and INFN, Lecce (Italy); Sinigardi, S. [Physics Department, University of Bologna and INFN, Bologna (Italy); Tramontana, A.; Schillaci, F. [INFN LNS Catania, Catania (Italy); Scuderi, V. [INFN LNS Catania, Catania (Italy); Institute of Physics of the ASCR, Prague (Czech Republic); Turchetti, G. [Physics Department, University of Bologna and INFN, Bologna (Italy); and others

    2014-07-15

    Laser-matter interaction at relativistic intensities opens up new research fields in the particle acceleration and related secondary sources, with immediate applications in medical diagnostics, biophysics, material science, inertial confinement fusion, up to laboratory astrophysics. In particular laser-driven ion acceleration is very promising for hadron therapy once the ion energy will attain a few hundred MeV. The limited value of the energy up to now obtained for the accelerated ions is the drawback of such innovative technique to the real applications. LILIA (laser induced light ions acceleration) is an experiment now running at LNF (Frascati) with the goal of producing a real proton beam able to be driven for significant distances (50–75 cm) away from the interaction point and which will act as a source for further accelerating structure. In this paper the description of the experimental setup, the preliminary results of solid target irradiation and start to end simulation for a post-accelerated beam up to 60 MeV are given.

  4. The LILIA (laser induced light ions acceleration) experiment at LNF

    Science.gov (United States)

    Agosteo, S.; Anania, M. P.; Caresana, M.; Cirrone, G. A. P.; De Martinis, C.; Delle Side, D.; Fazzi, A.; Gatti, G.; Giove, D.; Giulietti, D.; Gizzi, L. A.; Labate, L.; Londrillo, P.; Maggiore, M.; Nassisi, V.; Sinigardi, S.; Tramontana, A.; Schillaci, F.; Scuderi, V.; Turchetti, G.; Varoli, V.; Velardi, L.

    2014-07-01

    Laser-matter interaction at relativistic intensities opens up new research fields in the particle acceleration and related secondary sources, with immediate applications in medical diagnostics, biophysics, material science, inertial confinement fusion, up to laboratory astrophysics. In particular laser-driven ion acceleration is very promising for hadron therapy once the ion energy will attain a few hundred MeV. The limited value of the energy up to now obtained for the accelerated ions is the drawback of such innovative technique to the real applications. LILIA (laser induced light ions acceleration) is an experiment now running at LNF (Frascati) with the goal of producing a real proton beam able to be driven for significant distances (50-75 cm) away from the interaction point and which will act as a source for further accelerating structure. In this paper the description of the experimental setup, the preliminary results of solid target irradiation and start to end simulation for a post-accelerated beam up to 60 MeV are given.

  5. Light-matter interactions in engineered optical media (Conference Presentation)

    Science.gov (United States)

    Litchinitser, Natalia M.; Walasik, Wiktor T.; Silahli, Salih Z.

    2016-09-01

    The emergence of metamaterials also has a strong potential to enable a plethora of novel nonlinear light-matter interactions and even new nonlinear materials. In particular, nonlinear focusing and defocusing effects are of paramount importance for manipulation of the minimum focusing spot size of structured light beams necessary for nanoscale trapping, manipulation, and fundamental spectroscopic studies. Colloidal suspensions offer as a promising platform for engineering polarizibilities and realization of large and tunable nonlinearities. We will present our recent studies of the phenomenon of spatial modulational instability leading to laser beam filamentation in an engineered soft-matter nonlinear media as well as in negative index metamaterials. We will also discuss the possibilities of guiding, manipulating, and processing radio-and microwave-frequency radiation using photonic structures built of filaments in air. In particular, we introduce so-called virtual hyperbolic metamaterials formed by an array of plasma channels in air as a result of self-focusing of an intense laser pulse, and show that such structure can be used to manipulate microwave beams in a free space. Generation of virtual hyperbolic metamaterials requires a regular and spatially invariant distribution of plasma channels. Therefore, we discuss the generation of such large regular arrays of filaments and consider the interactions between multiple filaments, multiple filament formation, and phase-controlled structured filaments.

  6. Anomalous absorption of laser light on ion acoustic fluctuations

    Science.gov (United States)

    Rozmus, Wojciech; Bychenkov, Valery Yu.

    2016-10-01

    Theory of laser light absorption due to ion acoustic turbulence (IAT) is discussed in high Z plasmas where ion acoustic waves are weakly damped. Our theory applies to the whole density range from underdense to critical density plasmas. It includes an absorption rate for the resonance anomalous absorption due to linear conversion of electromagnetic waves into electron plasma oscillations by the IAT near the critical density in addition to the absorption coefficient due to enhanced effective electron collisionality. IAT is driven by large electron heat flux through the return current instability. Stationary spectra of IAT are given by weak plasma turbulence theory and applied in description of the anomalous absorption in the inertial confinement fusion plasmas at the gold walls of a hohlraum. This absorption is anisotropic in nature due to IAT angular anisotropy and differs for p- and s-polarization of the laser radiation. Possible experiments which could identify the resonance anomalous absorption in a laser heated plasma are discussed.

  7. Multifragmentation with GeV light-ion beams

    CERN Document Server

    Kwiatkowski, K; Wang, G; Lefort, T; Bracken, D S; Cornell, E; Foxford, E R; Ginger, D S; Viola, V E; Yoder, N R; Korteling, R G; Pollacco, E C; Legrain, R; Volant, C; Gimeno-Nogues, F; Laforest, R; Martin, E; Ramakrishnan, E; Rowland, D; Ruangma, A; Winchester, E M; Yennello, S J; Lynch, W G; Tsang, M B; Xi, H; Breuer, H; Morley, K B; Gushue, S; Remsberg, L P; Pienkowski, L; Brzychczyk, J; Botvina, A; Friedman, W A

    1999-01-01

    Multifragmentation studies with GeV light-ion beams indicate that for the most violent collisions, complex fragments are emitted during expansion of the hot source, followed by near simultaneous breakup of the system near rho/rho sub o approx ((1)/(3)). The results are compared with hybrid INC/EES and INC/SMM models. Preliminary data for the 8 GeV/c pi sup - and p-bar reactions on sup 1 sup 9 sup 7 Au show enhanced deposition energy for the antiproton beam.

  8. Light and heavy ion beam analysis of thin biological sections

    Science.gov (United States)

    Lee, Joonsup; Siegele, Rainer; Pastuovic, Zeljko; Hackett, Mark J.; Hunt, Nicholas H.; Grau, Georges E.; Cohen, David D.; Lay, Peter A.

    2013-07-01

    The application of ion beam analysis (IBA) techniques to thin biological sections (ThBS) presents unique challenges in sample preparation, data acquisition and analysis. These samples are often the end product of expensive, time-consuming experiments, which involve many steps that require careful attention. Analysis via several techniques can maximise the information that is collected from these samples. Particle-induced X-ray emission (PIXE) and Rutherford backscattering (RBS) spectroscopy are two generally non-destructive IBA techniques that use the same MeV ions and can be performed simultaneously. The use of heavy ion PIXE applied to thick samples has, in the past, resulted in X-ray spectra of a poorer quality when compared to those obtained with proton beams. One of the reasons for this is the shorter probing depth of the heavy ions, which does not affect thin sample analysis. Therefore, we have investigated and compared 3-MeV proton and 36-MeV carbon ion beams on 7-μm thick mouse brain sections at the ANSTO Heavy ion microprobe (HIMP). The application of a 36-MeV C4+ ion beam for PIXE mapping of ThBS on thin Si3N4 substrate windows produced spectra of high quality that displayed close to a nine-times gain in signal yield (Z2/q) when compared to those obtained for 3-MeV protons for P, S, Cl and K but not for Fe, Cu and Zn. Image quality was overall similar; however, some elements showed better contrast and features with protons whilst others showed improved contrast with a carbon ion beam. RBS spectra with high enough counting statistics were easily obtained with 3-MeV proton beams resulting in high resolution carbon maps, however, the count rate for nitrogen and oxygen was too low. The results demonstrate that on thin samples, 36-MeV C4+ will produce good quality PIXE spectra in less time; therefore, carbon ions may be advantageous depending on which element is being studied. However, these advantages may be outweighed by the inherent disadvantages including

  9. Light and heavy ion beam analysis of thin biological sections

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Joonsup, E-mail: joonsup.lee@sydney.edu.au [School of Chemistry, The University of Sydney, NSW 2006 (Australia); Siegele, Rainer, E-mail: rainer.siegele@ansto.gov.au [Institute for Environmental Research, ANSTO, NSW 2234 (Australia); Pastuovic, Zeljko, E-mail: zeljko.pastuovic@ansto.gov.au [Institute for Environmental Research, ANSTO, NSW 2234 (Australia); Hackett, Mark J., E-mail: mark.hackett@usask.ca [School of Chemistry, The University of Sydney, NSW 2006 (Australia); Hunt, Nicholas H., E-mail: nhunt@med.usyd.edu.au [Molecular Immunopathology Unit, Bosch Institute and School of Medical Sciences, The University of Sydney, NSW 2006 (Australia); Grau, Georges E., E-mail: georges.grau@sydney.edu.au [Vascular Immunology Unit, Bosch Institute and School of Medical Sciences, The University of Sydney, NSW 2006 (Australia); Cohen, David D., E-mail: david.cohen@ansto.gov.au [Institute for Environmental Research, ANSTO, NSW 2234 (Australia); Lay, Peter A., E-mail: peter.lay@sydney.edu.au [School of Chemistry, The University of Sydney, NSW 2006 (Australia)

    2013-07-01

    The application of ion beam analysis (IBA) techniques to thin biological sections (ThBS) presents unique challenges in sample preparation, data acquisition and analysis. These samples are often the end product of expensive, time-consuming experiments, which involve many steps that require careful attention. Analysis via several techniques can maximise the information that is collected from these samples. Particle-induced X-ray emission (PIXE) and Rutherford backscattering (RBS) spectroscopy are two generally non-destructive IBA techniques that use the same MeV ions and can be performed simultaneously. The use of heavy ion PIXE applied to thick samples has, in the past, resulted in X-ray spectra of a poorer quality when compared to those obtained with proton beams. One of the reasons for this is the shorter probing depth of the heavy ions, which does not affect thin sample analysis. Therefore, we have investigated and compared 3-MeV proton and 36-MeV carbon ion beams on 7-μm thick mouse brain sections at the ANSTO Heavy ion microprobe (HIMP). The application of a 36-MeV C{sup 4+} ion beam for PIXE mapping of ThBS on thin Si{sub 3}N{sub 4} substrate windows produced spectra of high quality that displayed close to a nine-times gain in signal yield (Z{sup 2}/q) when compared to those obtained for 3-MeV protons for P, S, Cl and K but not for Fe, Cu and Zn. Image quality was overall similar; however, some elements showed better contrast and features with protons whilst others showed improved contrast with a carbon ion beam. RBS spectra with high enough counting statistics were easily obtained with 3-MeV proton beams resulting in high resolution carbon maps, however, the count rate for nitrogen and oxygen was too low. The results demonstrate that on thin samples, 36-MeV C{sup 4+} will produce good quality PIXE spectra in less time; therefore, carbon ions may be advantageous depending on which element is being studied. However, these advantages may be outweighed by the

  10. The measurements of light high-energy ions in NINA-2 experiment

    Directory of Open Access Journals (Sweden)

    A. Leonov

    2007-10-01

    Full Text Available The flux of energetic light ions at low altitude is both an important input and output for self-consistent calculations of albedo particles resulting from the interaction of trapped and cosmic ray particles, with the upper atmosphere. In addition, data on the flux of light ions are needed to evaluate radiation damages on space-borne instruments and on space mission crews. In spite of that, sources of data on the flux of energetic ions at LEO are roughly limited to the AP-8 model, CREME/CREME96 codes and the SAMPEX, NOAA/TIROS satellites. The existing and operational European SAC-C/ICARE and PROBA-1/SREM instruments could also be potential sources for proton data at LEO. Although AP-8 and SAMPEX/PSB97 may be publicly accessed through the SPENVIS, they exhibit an order of magnitude difference in low altitude proton fluxes and they do not contain helium fluxes. Therefore, improved light ion radiation models are still needed.

    In this paper we present a procedure to identify and measure the energy of ions that are not stopped in the NINA-2 instrument. Moreover, problems related to particles that cross the instrument in the opposite direction are addressed and shown to be a possible cause of particle misidentification. Measuring fluxes of low abundance elements like energetic helium ions requires a good characterisation of all possible sources of backgrounds in the detector. Hints to determine the several contributions to the background are presented herein and may be applied to extract an order of magnitude of energetic ions fluxes from existing data sets, while waiting for dedicated high performance instruments.

  11. Light-Activated Ion Channels for Remote Control of Neural Activity

    OpenAIRE

    Chambers, James J.; Richard H Kramer

    2008-01-01

    Light-activated ion channels provide a new opportunity to precisely and remotely control neuronal activity for experimental applications in neurobiology. In the past few years, several strategies have arisen that allow light to control ion channels and therefore neuronal function. Light-based triggers for ion channel control include caged compounds, which release active neurotransmitters when photolyzed with light, and natural photoreceptive proteins, which can be expressed exogenously in neu...

  12. Adaptive Optics and Lucky Imager (AOLI): presentation and first light

    CERN Document Server

    Velasco, S; Mackay, C; Oscoz, A; King, D L; Crass, J; Díaz-Sánchez, A; Femenía, B; González-Escalera, V; Labadie, L; López, R L; Garrido, A Pérez; Puga, M; Rodríguez-Ramos, L F; Zuther, J

    2015-01-01

    In this paper we present the Adaptive Optics Lucky Imager (AOLI), a state-of-the-art instrument which makes use of two well proved techniques for extremely high spatial resolution with ground-based telescopes: Lucky Imaging (LI) and Adaptive Optics (AO). AOLI comprises an AO system, including a low order non-linear curvature wavefront sensor together with a 241 actuators deformable mirror, a science array of four 1024x1024 EMCCDs, allowing a 120x120 down to 36x36 arcseconds field of view, a calibration subsystem and a powerful LI software. Thanks to the revolutionary WFS, AOLI shall have the capability of using faint reference stars ({\\it I\\/} $\\sim$ 16.5-17.5), enabling it to be used over a much wider part of the sky than with common Shack-Hartmann AO systems. This instrument saw first light in September 2013 at William Herschel Telescope. Although the instrument was not complete, these commissioning demonstrated its feasibility, obtaining a FWHM for the best PSF of 0.151$\\pm$0.005 arcsec and a plate scale o...

  13. A semi-analytical radiobiological model may assist treatment planning in light ion radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Kundrat, Pavel [Institute of Physics, Academy of Sciences of the Czech Republic, Na Slovance 2, CZ-182 21 Prague 8 (Czech Republic)

    2007-12-07

    A semi-analytical model of light ions' Bragg peaks is presented and used in conjunction with a detailed probabilistic radiobiological module to predict the biological effectiveness of light ion irradiation for hadrontherapy applications. The physical Bragg peak model is based on energy-loss calculations with the SRIM code and phenomenological formulae for the energy-loss straggling. Effects of nuclear reactions are accounted for on the level of reducing the number of primary particles only. Reaction products are not followed at all and their contribution to dose deposition is neglected. Beam widening due to multiple scattering and calculations of spread-out Bragg peaks are briefly discussed. With this simple physical model, integral depth-dose distributions are calculated for protons, carbon, oxygen and neon ions. A good agreement with published experimental data is observed for protons and lower energy ions (with ranges in water up to approximately 15 cm), while less satisfactory results are obtained for higher energy ions due to the increased role of nuclear reaction products, neglected in this model. A detailed probabilistic radiobiological module is used to complement the simple physical model and to estimate biological effectiveness along the penetration depth of Bragg peak irradiation. Excellent agreement is found between model predictions and experimental data for carbon beams, indicating potential applications of the present scheme in treatment planning in light ion hadrontherapy. Due to the semi-analytical character of the model, leading to high computational speed, applications are foreseen in particular in the fully biological optimization of multiple irradiation fields and intensity-modulated beams.

  14. A semi-analytical radiobiological model may assist treatment planning in light ion radiotherapy.

    Science.gov (United States)

    Kundrát, Pavel

    2007-12-07

    A semi-analytical model of light ions' Bragg peaks is presented and used in conjunction with a detailed probabilistic radiobiological module to predict the biological effectiveness of light ion irradiation for hadrontherapy applications. The physical Bragg peak model is based on energy-loss calculations with the SRIM code and phenomenological formulae for the energy-loss straggling. Effects of nuclear reactions are accounted for on the level of reducing the number of primary particles only. Reaction products are not followed at all and their contribution to dose deposition is neglected. Beam widening due to multiple scattering and calculations of spread-out Bragg peaks are briefly discussed. With this simple physical model, integral depth-dose distributions are calculated for protons, carbon, oxygen and neon ions. A good agreement with published experimental data is observed for protons and lower energy ions (with ranges in water up to approximately 15 cm), while less satisfactory results are obtained for higher energy ions due to the increased role of nuclear reaction products, neglected in this model. A detailed probabilistic radiobiological module is used to complement the simple physical model and to estimate biological effectiveness along the penetration depth of Bragg peak irradiation. Excellent agreement is found between model predictions and experimental data for carbon beams, indicating potential applications of the present scheme in treatment planning in light ion hadrontherapy. Due to the semi-analytical character of the model, leading to high computational speed, applications are foreseen in particular in the fully biological optimization of multiple irradiation fields and intensity-modulated beams.

  15. Multiphoton microscopy and image guided light activated therapy using nanomaterials (Conference Presentation)

    Science.gov (United States)

    Prasad, Paras N.

    2017-02-01

    This talk will focus on design and applications of nanomaterials exhibiting strong multiphoton upconversion for multiphoton microscopy as well as for image-guided and light activated therapy .1-3 Such processes can occur by truly nonlinear optical interactions proceeding through virtual intermediate states or by stepwise coupled linear excitations through real intermediate states. Multiphoton processes in biocompatible multifunctional nanoparticles allow for 3D deep tissue imaging. In addition, they can produce in-situ photon conversion of deep tissue penetrating near IR light into a needed shorter wavelength light for photo-activated therapy at a targeted site, thus overcoming the limited penetration of UV or visible light into biological media. We are using near IR emitters such as silicon quantum dots which also exhibit strong multiphoton excitation for multiphoton microscopy. Another approach involves nonlinear nanocrystals such as ZnO which can produce four wave mixing, sum frequency generation as well as second harmonic generation to convert a deep tissue penetrating Near IR light at the targeted biological site to a desired shorter wavelength light suitable for bio imaging or activation of a therapy. We have utilized this approach to activate a photosensitizer for photodynamic therapy. Yet another type of upconversion materials is rare-earth ion doped optical nanotransformers which transform a Near IR (NIR) light from an external source by sequential single photon absorption, in situ and on demand, to a needed wavelength. Applications of these nanotransformers in multiphoton photoacoustic imaging will also be presented. An exciting direction pursued by us using these multiphoton nanoparticles, is functional imaging of brain. Simultaneously, they can effect optogenetics for regioselective stimulation of neurons for providing an effective intervention/augmentation strategy to enhance the cognitive state and lead to a foundation for futuristic vision of super

  16. Increased Serum Free Light Chains Precede the Presentation of Immunoglobulin Light Chain Amyloidosis

    Science.gov (United States)

    Weiss, Brendan M.; Hebreo, Joseph; Cordaro, Daniel V.; Roschewski, Mark J.; Baker, Thomas P.; Abbott, Kevin C.; Olson, Stephen W.

    2014-01-01

    Purpose Patients with immunoglobulin light chain amyloidosis (AL amyloidosis) generally present with advanced organ dysfunction and have a high risk of early death. We sought to characterize monoclonal immunoglobulin (M-Ig) light chains before clinical presentation of AL amyloidosis. Patients and Methods We obtained prediagnostic sera from 20 cases with AL amyloidosis and 20 healthy controls matched for age, sex, race, and age of serum sample from the Department of Defense Serum Repository. Serum protein electrophoresis with immunofixation and serum free light chain (FLC) analysis were performed on all samples. Results An M-Ig was detected in 100% of cases and 0% of controls (P diff) was higher in cases compared with controls at all time periods, less than 4 years (174.8 v 0.3 mg/L; P diff was greater than 23 mg/L in 85% of cases and 0% of controls (P diff level increased more than 10% per year in 84% of cases compared with 16% of controls (P < .001). Conclusion Increase of FLCs, including within the accepted normal range, precedes the development of AL amyloidosis for many years. PMID:25024082

  17. Good vibrations: Controlling light with sound (Conference Presentation)

    Science.gov (United States)

    Eggleton, Benjamin J.; Choudhary, Amol

    2016-10-01

    One of the surprises of nonlinear optics, is that light may interact strongly with sound. Intense laser light literally "shakes" the glass in optical fibres, exciting acoustic waves (sound) in the fibre. Under the right conditions, it leads to a positive feedback loop between light and sound termed "Stimulated Brillouin Scattering," or simply SBS. This nonlinear interaction can amplify or filter light waves with extreme precision in frequency which makes it uniquely suited to solve key problems in the fields of defence, biomedicine, wireless communications, spectroscopy and imaging. We have achieved the first demonstration of SBS in compact chip-scale structures, carefully designed so that the optical fields and the acoustic fields are simultaneously confined and guided. This new platform has opened a range of new functionalities that are being applied in communications and defence with breathtaking performance and compactness. My talk will introduce this new field and review our progress and achievements, including silicon based optical phononic processor.

  18. Light Detection and Ranging Point Cloud Data: 2000 - Present

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — LIDAR (Light Detection and Ranging) discrete-return point cloud data are available in the American Society for Photogrammetry and Remote Sensing (ASPRS) LAS format....

  19. Light Detection and Ranging Point Cloud Data: 2000 - Present

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — LIDAR (Light Detection and Ranging) discrete-return point cloud data are available in the American Society for Photogrammetry and Remote Sensing (ASPRS) LAS format....

  20. Asymmetric Functional Conversion of Eubacterial Light-driven Ion Pumps.

    Science.gov (United States)

    Inoue, Keiichi; Nomura, Yurika; Kandori, Hideki

    2016-05-06

    In addition to the well-known light-driven outward proton pumps, novel ion-pumping rhodopsins functioning as outward Na(+) and inward Cl(-) pumps have been recently found in eubacteria. They convert light energy into transmembrane electrochemical potential difference, similar to the prototypical archaeal H(+) pump bacteriorhodopsin (BR) and Cl(-) pump halorhodopsin (HR). The H(+), Na(+), and Cl(-) pumps possess the conserved respective DTE, NDQ, and NTQ motifs in the helix C, which likely serve as their functional determinants. To verify this hypothesis, we attempted functional interconversion between selected pumps from each category by mutagenesis. Introduction of the proton-pumping motif resulted in successful Na(+) → H(+) functional conversion. Introduction of the respective characteristic motifs with several additional mutations leads to successful Na(+) → Cl(-) and Cl(-) → H(+) functional conversions, whereas remaining conversions (H(+) → Na(+), H(+) → Cl(-), Cl(-) → Na(+)) were unsuccessful when mutagenesis of 4-6 residues was used. Phylogenetic analysis suggests that a H(+) pump is the common ancestor of all of these rhodopsins, from which Cl(-) pumps emerged followed by Na(+) pumps. We propose that successful functional conversions of these ion pumps are achieved exclusively when mutagenesis reverses the evolutionary amino acid sequence changes. Dependence of the observed functional conversions on the direction of evolution strongly suggests that the essential structural mechanism of an ancestral function is retained even after the gain of a new function during natural evolution, which can be evoked by a few mutations. By contrast, the gain of a new function needs accumulation of multiple mutations, which may not be easily reproduced by limited mutagenesis in vitro.

  1. Increased serum free light chains precede the presentation of immunoglobulin light chain amyloidosis.

    Science.gov (United States)

    Weiss, Brendan M; Hebreo, Joseph; Cordaro, Daniel V; Roschewski, Mark J; Baker, Thomas P; Abbott, Kevin C; Olson, Stephen W

    2014-09-01

    Patients with immunoglobulin light chain amyloidosis (AL amyloidosis) generally present with advanced organ dysfunction and have a high risk of early death. We sought to characterize monoclonal immunoglobulin (M-Ig) light chains before clinical presentation of AL amyloidosis. We obtained prediagnostic sera from 20 cases with AL amyloidosis and 20 healthy controls matched for age, sex, race, and age of serum sample from the Department of Defense Serum Repository. Serum protein electrophoresis with immunofixation and serum free light chain (FLC) analysis were performed on all samples. An M-Ig was detected in 100% of cases and 0% of controls (P < .001). The M-Ig was present in 100%, 80%, and 42% of cases at less than 4 years, 4 to 11 years, and more than 11 years before diagnosis, respectively. The median FLC differential (FLC-diff) was higher in cases compared with controls at all time periods, less than 4 years (174.8 v 0.3 mg/L; P < .001), 4 to 11 years (65.1 v 2.2 mg/L; P < .001), and more than 11 years (4.5 v 0.4 mg/L; P = .03) before diagnosis. The FLC-diff was greater than 23 mg/L in 85% of cases and 0% of controls (P < .001). The FLC-diff level increased more than 10% per year in 84% of cases compared with 16% of controls (P < .001). Increase of FLCs, including within the accepted normal range, precedes the development of AL amyloidosis for many years. © 2014 by American Society of Clinical Oncology.

  2. ESS-Bilbao light-ion linear accelerator and neutron source: design and applications

    Science.gov (United States)

    Abad, E.; Arredondo, I.; Badillo, I.; Belver, D.; Bermejo, F. J.; Bustinduy, I.; Cano, D.; Cortazar, D.; de Cos, D.; Djekic, S.; Domingo, S.; Echevarria, P.; Eguiraun, M.; Etxebarria, V.; Fernandez, D.; Fernandez, F. J.; Feuchtwanger, J.; Garmendia, N.; Harper, G.; Hassanzadegan, H.; Jugo, J.; Legarda, F.; Magan, M.; Martinez, R.; Megia, A.; Muguira, L.; Mujika, G.; Muñoz, J. L.; Ortega, A.; Ortega, J.; Perlado, M.; Portilla, J.; Rueda, I.; Sordo, F.; Toyos, V.; Vizcaino, A.

    2011-10-01

    The baseline design for the ESS-Bilbao light-ion linear accelerator and neutron source has been completed and the normal conducting section of the linac is at present under construction. The machine has been designed to be compliant with ESS specifications following the international guidelines of such project as described in Ref. [1]. The new accelerator facility in Bilbao will serve as a base for support of activities on accelerator physics carried out in Spain and southern Europe in the frame of different ongoing international collaborations. Also, a number of applications have been envisaged in the new Bilbao facility for the outgoing light ion beams as well as from fast neutrons produced by low-energy neutron-capture targets, which are briefly described.

  3. Collisional cooling of light ions by co-trapped heavy atoms

    CERN Document Server

    Dutta, Sourav; Rangwala, S A

    2015-01-01

    The most generic cooling and thermalization pathway at the lowest temperatures is via elastic collisions. In hybrid ion-atom traps, ion cooling to temperatures where low partial wave collisions dominate require the collisional cooling mechanism to be well understood and controlled. There exists great uncertainty on whether cooling of light ions by heavier neutral atoms is possible. Here we experimentally demonstrate the cooling of light ions by co-trapped heavy atoms for the first time. We show that trapped 39K+ ions are cooled by localized ultracold neutral 85Rb atoms for an ion-atom mass ratio where most theoretical models predict ion heating. We demonstrate, based on detailed numerical simulation of our ion-cooling model, which is in excellent agreement with experiments, that cooling of ions by localized cold atoms is possible for any mass ratio. Our result opens up the possibility of studying quantum collisions and chemistry in trapped atom-ion systems.

  4. High Energy Laboratory Astrophysics Experiments using electron beam ion traps and advanced light sources

    Science.gov (United States)

    Brown, Gregory V.; Beiersdorfer, Peter; Bernitt, Sven; Eberle, Sita; Hell, Natalie; Kilbourne, Caroline; Kelley, Rich; Leutenegger, Maurice; Porter, F. Scott; Rudolph, Jan; Steinbrugge, Rene; Traebert, Elmar; Crespo-Lopez-Urritia, Jose R.

    2015-08-01

    We have used the Lawrence Livermore National Laboratory's EBIT-I electron beam ion trap coupled with a NASA/GSFC microcalorimeter spectrometer instrument to systematically address problems found in the analysis of high resolution X-ray spectra from celestial sources, and to benchmark atomic physics codes employed by high resolution spectral modeling packages. Our results include laboratory measurements of transition energies, absolute and relative electron impact excitation cross sections, charge exchange cross sections, and dielectronic recombination resonance strengths. More recently, we have coupled to the Max-Plank Institute for Nuclear Physics-Heidelberg's FLASH-EBIT electron beam ion trap to third and fourth generation advanced light sources to measure photoexcitation and photoionization cross sections, as well as, natural line widths of X-ray transitions in highly charged iron ions. Selected results will be presented.

  5. Misfolded Amyloid Ion Channels Present Mobile β-Sheet Subunits in Contrast to Conventional Ion Channels

    OpenAIRE

    Jang, Hyunbum; Arce, Fernando Teran; Capone, Ricardo; Ramachandran, Srinivasan; Lal, Ratnesh; Nussinov, Ruth

    2009-01-01

    In Alzheimer's disease, calcium permeability through cellular membranes appears to underlie neuronal cell death. It is increasingly accepted that calcium permeability involves toxic ion channels. We modeled Alzheimer's disease ion channels of different sizes (12-mer to 36-mer) in the lipid bilayer using molecular dynamics simulations. Our Aβ channels consist of the solid-state NMR-based U-shaped β-strand-turn-β-strand motif. In the simulations we obtain ion-permeable channels whose subunit mo...

  6. Micro-hardness evaluation of a micro-hybrid composite resin light cured with halogen light, light-emitting diode and argon ion laser.

    Science.gov (United States)

    Rode, Katia M; de Freitas, Patricia M; Lloret, Patricia R; Powell, Lynn G; Turbino, Miriam L

    2009-01-01

    This in vitro study aimed to determine whether the micro-hardness of a composite resin is modified by the light units or by the thickness of the increment. Composite resin disks were divided into 15 groups (n = 5), according to the factors under study: composite resin thickness (0 mm, 1 mm, 2 mm , 3 mm and 4 mm) and light units. The light activation was performed with halogen light (HL) (40 s, 500 mW/cm(2)), argon ion laser (AL) (30 s, 600 mW/cm(2)) or light-emitting diode (LED) (30 s, 400 mW/cm(2)). Vickers micro-hardness tests were performed after 1 week and were carried out on the top surface (0 mm-control) and at different depths of the samples. Analysis of variance (ANOVA) and Tukey tests (P hardness values than the LED. In groups with 3 mm and 4 mm thickness, the HL also showed higher micro-hardness values than the groups activated by the AL and the LED. Only the HL presented satisfactory polymerization with 3 mm of thickness. With a 4 mm increment no light unit was able to promote satisfactory polymerization.

  7. Li-ion battery materials: present and future

    Directory of Open Access Journals (Sweden)

    Naoki Nitta

    2015-06-01

    Full Text Available This review covers key technological developments and scientific challenges for a broad range of Li-ion battery electrodes. Periodic table and potential/capacity plots are used to compare many families of suitable materials. Performance characteristics, current limitations, and recent breakthroughs in the development of commercial intercalation materials such as lithium cobalt oxide (LCO, lithium nickel cobalt manganese oxide (NCM, lithium nickel cobalt aluminum oxide (NCA, lithium iron phosphate (LFP, lithium titanium oxide (LTO and others are contrasted with that of conversion materials, such as alloying anodes (Si, Ge, Sn, etc., chalcogenides (S, Se, Te, and metal halides (F, Cl, Br, I. New polyanion cathode materials are also discussed. The cost, abundance, safety, Li and electron transport, volumetric expansion, material dissolution, and surface reactions for each type of electrode materials are described. Both general and specific strategies to overcome the current challenges are covered and categorized.

  8. Photocatalytic performance of Fe-, Ni-, or Cu-ion implanted TiO{sub 2} films under UV light, visible light and sunlight irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Qin, L.Z., E-mail: qin8394@163.com [School of Material Science and Engineering, Southwest University, Chongqing 400715 (China); Liang, H.; Liao, B.; Liu, A.D.; Wu, X.Y. [Key Laboratory of Beam Technology and Material Modification of Ministry of Education, Beijing Normal University, Beijing 100875 (China); Sun, J. [School of Material Science and Engineering, Southwest University, Chongqing 400715 (China)

    2013-07-15

    TiO{sub 2} thin films were fabricated on microscope glass slides by sol–gel method. Then Fe, Ni or Cu ions were implanted in the films. XRD, XPS and UV–Vis spectrophotometer technologies were used to characterize the films. The results of photodegradation of methyl orange in aqueous solution demonstrate: (1) the films are of visible light response photocatalytic activity; (2) under UV light and sunlight excitation, all the films present less efficient than pure TiO{sub 2} film. The photodegradation effects of transition metal ion implanted TiO{sub 2} thin films were discussed.

  9. Morphing dynamics in light-triggered LC polymers (Conference Presentation)

    Science.gov (United States)

    Broer, Dirk J.

    2017-02-01

    Polymers that can change shape or surface topography in response to a trigger have a wide application potential varying from micro-robotics to avionics. Preferably this morphing proceeds fast and reversibly. We developed new morphing principles based on in-situ photopolymerized liquid crystal networks and on hybrid low molecular weight liquid crystals and liquid crystal networks. Commonly the triggers are temperature, light, pH or the presence of chemicals or other moisture. In the lecture we will focus on UV actuation and demonstrate that by accurate positioning of molecules over all three dimensions of a thin film or coating, the deformation figures can be pre-engineered. They can vary from simple gratings to very complex such as fingerprints that can be switched between off (flat surface) and on (corrugated surface) by light. The underlying principles are based on photo-induced changes in the degree of order of liquid crystal polymer networks and the accompanying changes in density by the formation of free volume. The surfaces can be switched with frequencies of the order of 0.1 Hz. In the lecture we will discuss several methods to fabricate the responsive layers as well as some of the most eye-catching properties. Also the mechanism of free volume generation will be addressed in terms of molecular dynamics and resonance.

  10. The measurements of light high-energy ions in NINA-2 experiment

    NARCIS (Netherlands)

    Leonov, A.; Cyamukungu, M.; Cabrera, J.; Leleux, P.; Gregoire, Gh.; Benck, S.; Mikhailov, V.; Bakaldin, A.; Galper, A.; Koldashov, S.; Voronov, S.; Casolino, M.; De Pascale, M. P.; Picozza, P.; Sparvoli, R.; Ricci, M.

    2007-01-01

    The flux of energetic light ions at low altitude is both an important input and output for self-consistent calculations of albedo particles resulting from the interaction of trapped and cosmic ray particles, with the upper atmosphere. In addition, data on the flux of light ions are needed to evaluat

  11. Elastic scattering and total reaction cross sections with low-energy light radioactive ion beams.

    Directory of Open Access Journals (Sweden)

    Guimarães Valdir

    2011-10-01

    Full Text Available Elastic scattering experiments have being performed with low-energy radioactive ion beams produced by the RIBRAS facility in Sao Paulo, Brazil. Here I present the results for elastic scattering of 6He on several targets and light beams on 12C target. Special emphasis is given to the analysis of experiments were angular distributions for the elastic scattering of beryllium isotopes projectiles, 7Be, 9Be and 10Be, on a light target 12C were obtained. These elastic scattering angular distributions have been analysed in terms of optical model using the double-folding Sao Paulo potential. From this analysis, the total reaction cross section were also deduced and compared to the total reaction cross sections for many other light projectiles on 12C target. The comparison was made in terms of Universal Function reduction method.

  12. Light-Ion-Induced Multifragmentation: The ISiS Project

    CERN Document Server

    Viola, V E

    2006-01-01

    An extensive study of GeV light-ion-induced multifragmentation and its possible interpretation in terms of a nuclear liquid-gas phase transition has been performed with the Indiana Silicon Sphere (ISiS)4 pi detector array. Measurements were performed with 5-15 GeV/c p, pbar, and pion beams incident on $^{197}$Au and 2-5 GeV $^3$He incident on $^{nat}$Ag and $^{197}$Au targets. Both the reaction dynamics and the subsequent decay of the heavy residues have been explored. The data provide evidence for a dramatic change in the reaction observables near an excitation energy of E*/A = 4-5 MeV per residue nucleon. In this region, fragment multiplicities and energy spectra indicate emission from an expanded/dilute source on a very short time scale (20-50 fm/c). These properties, along with caloric curve and scaling-law behavior, yield a pattern that is consistent with a nuclear liquid-gas phase transition.

  13. Light-ion-induced multifragmentation: The ISiS project

    Science.gov (United States)

    Viola, V. E.; Kwiatkowski, K.; Beaulieu, L.; Bracken, D. S.; Breuer, H.; Brzychczyk, J.; de Souza, R. T.; Ginger, D. S.; Hsi, W.-C.; Korteling, R. G.; Lefort, T.; Lynch, W. G.; Morley, K. B.; Legrain, R.; Pienkowski, L.; Pollacco, E. C.; Renshaw, E.; Ruangma, A.; Tsang, M. B.; Volant, C.; Wang, G.; Yennello, S. J.; Yoder, N. R.

    2006-11-01

    An extensive study of GeV light-ion-induced multifragmentation and its possible interpretation in terms of a nuclear liquid-gas phase transition has been performed with the Indiana Silicon Sphere (ISiS) 4π detector array. Measurements were performed with 5-15 GeV/ c p, pbar, and π- beams incident on 197Au and 2-5 GeV 3He incident on natAg and 197Au targets. Both the reaction dynamics and the subsequent decay of the heavy residues have been explored. The data provide evidence for a dramatic change in the reaction observables near an excitation energy of E*/A=4-5 MeV/residue nucleon. In this region, fragment multiplicities and energy spectra indicate emission from an expanded/dilute source on a very short time scale (20-50 fm/ c). These properties, along with caloric curve and scaling-law behavior, yield a pattern that is consistent with a nuclear liquid-gas phase transition.

  14. Misfolded amyloid ion channels present mobile beta-sheet subunits in contrast to conventional ion channels.

    Science.gov (United States)

    Jang, Hyunbum; Arce, Fernando Teran; Capone, Ricardo; Ramachandran, Srinivasan; Lal, Ratnesh; Nussinov, Ruth

    2009-12-02

    In Alzheimer's disease, calcium permeability through cellular membranes appears to underlie neuronal cell death. It is increasingly accepted that calcium permeability involves toxic ion channels. We modeled Alzheimer's disease ion channels of different sizes (12-mer to 36-mer) in the lipid bilayer using molecular dynamics simulations. Our Abeta channels consist of the solid-state NMR-based U-shaped beta-strand-turn-beta-strand motif. In the simulations we obtain ion-permeable channels whose subunit morphologies and shapes are consistent with electron microscopy/atomic force microscopy. In agreement with imaged channels, the simulations indicate that beta-sheet channels break into loosely associated mobile beta-sheet subunits. The preferred channel sizes (16- to 24-mer) are compatible with electron microscopy/atomic force microscopy-derived dimensions. Mobile subunits were also observed for beta-sheet channels formed by cytolytic PG-1 beta-hairpins. The emerging picture from our large-scale simulations is that toxic ion channels formed by beta-sheets spontaneously break into loosely interacting dynamic units that associate and dissociate leading to toxic ionic flux. This sharply contrasts intact conventional gated ion channels that consist of tightly interacting alpha-helices that robustly prevent ion leakage, rather than hydrogen-bonded beta-strands. The simulations suggest why conventional gated channels evolved to consist of interacting alpha-helices rather than hydrogen-bonded beta-strands that tend to break in fluidic bilayers. Nature designs folded channels but not misfolded toxic channels.

  15. The present status of the Shanghai electron beam ion trap

    Institute of Scientific and Technical Information of China (English)

    GUO Pan-Lin; WANG Xin-Cheng; ZHU Xi-Kai; JIANG Di-Kui; HUTTON R; ZOU Ya-Ming; HU Wei; GONG Pei-Rong; LU Di; HE Mian-Hong; WU Shimin; YAO Ke; HUANG Min; ZHANG Xue-Mei

    2005-01-01

    In this report, an introduction to the structure of Shanghai EBIT, a brief description of the status of Shanghai EBIT project, and a short discussion of the first results of Shanghai EBIT are presented.

  16. Anderson localization to enhance light-matter interaction (Conference Presentation)

    Science.gov (United States)

    Garcia, Pedro David

    2016-04-01

    Deliberately introducing disorder in low-dimensional nanostructures like photonic crystal waveguides (PCWs) [1] or photonic crystals (PCs) [2] leads to Anderson localization where light is efficiently trapped by random multiple scattering with the lattice imperfections. These disorder-induced optical modes hace been demonstrated to be very promising for cavity-quantum electrodynamics (QED) experiments where the radiative emission rate of single quantum emitters can be controlled when tuned through resonance with one of these random cavities. Our statistical analysis of the emission dynamics from single quantum dots embeded in disordered PCWs [3] provides detailed insigth about the statistical properties of QED in these complex nanostructures. In addition, using internal light sources reveals new physics in the form of nonuniversal intensity correlations between the different scattered paths within the structure which imprint the local QED properties deep inside the complex structure onto the far-field intensity pattern [2]. Finally, increasing the optical gain in PCWs allows on-chip random nanolasing where the cavity feedback is provided by the intrinsic disorder which enables highly efficient, stable, and broadband tunable lasers with very small mode volumes [4]. The figure of merit of these disorder-induced cavities is their localization length which determines to a large degree the coupling efficiency of a quantum emitter to a disorder-induced cavity as well as the efficiency of random lasing and reveals a strongly dispersive behavior and a non-trivial dependence on disorder in PCWs [5]. [1] L. Sapienza, H. Thyrrestrup, S. Stobbe, P.D. Garcia, S. Smolka, and P. Lodahl, Science 327, 1352 (2010). [2] P. D. García, S. Stobbe, I. Soellner and P. Lodahl, Physical Review Letters 109, 253902 (2012). [3] A. Javadi, S. Maibom, L. Sapienza, H. Thyrrestrup, P.D. Garcia, and P. Lodahl, Opt. Express 22, 30992 (2014). [4] J. Liu, P. D. Garcia, S. Ek, N. Gregersen, T. Suhr, M

  17. An improved extraction for the multicusp-type light ion-ion source apparatus

    Science.gov (United States)

    Reijonen, J.; Heikkinen, P.; Liukkonen, E.; ńrje, J.

    1998-02-01

    A new ion extraction system has been developed for use with the light ion source apparatus (LIISA) of the Accelerator Laboratory. The aim of the new extraction system is to have a more intense and better quality beam. For simulation of the beam behavior at the extraction region a computer code IGUNe has been used. The simulation shows that a simple triode extraction would be efficient enough to extract total beam intensities of around 5 mA at an extraction voltage of 10-15 kV. At the same time, with the carefully designed plasma electrode, the emittance could be decreased significantly from the original design. The new extraction was installed in May 1997 and the results have been encouraging. The transport efficiency of the extracted beam to the first Faraday cup (at a distance of 1.2 m) was 100% and the maximum proton current obtained was 2.0 mA. The maximum proton current in the cyclotron inflector is 1.0 mA, which is eight times larger than the previous record.

  18. Collisional Cooling of Light Ions by Cotrapped Heavy Atoms.

    Science.gov (United States)

    Dutta, Sourav; Sawant, Rahul; Rangwala, S A

    2017-03-17

    We experimentally demonstrate cooling of trapped ions by collisions with cotrapped, higher-mass neutral atoms. It is shown that the lighter ^{39}K^{+} ions, created by ionizing ^{39}K atoms in a magneto-optical trap (MOT), when trapped in an ion trap and subsequently allowed to cool by collisions with ultracold, heavier ^{85}Rb atoms in a MOT, exhibit a longer trap lifetime than without the localized ^{85}Rb MOT atoms. A similar cooling of trapped ^{85}Rb^{+} ions by ultracold ^{133}Cs atoms in a MOT is also demonstrated in a different experimental configuration to validate this mechanism of ion cooling by localized and centered ultracold neutral atoms. Our results suggest that the cooling of ions by localized cold atoms holds for any mass ratio, thereby enabling studies on a wider class of atom-ion systems irrespective of their masses.

  19. Development of niobium spoke cavities for a superconducting light-ion Linac.

    Energy Technology Data Exchange (ETDEWEB)

    Shepard, K. W.

    1998-11-18

    This paper reports the development of 350 MHz niobium superconducting cavities for the velocity range 0.2< v/c <0.6. Such cavities could be used to form a linac of exceptional flexibility, capable of efficiently accelerating beams of either protons, deuterons, or any of a wide range of light ions, at intensities sufficient for a production beam for a radioactive beam facility. Results of numerical modeling for several resonator geometries are presented. The design and construction status of prototype niobium cavities is discussed.

  20. Shaping laser accelerated ions for future applications – The LIGHT collaboration

    Energy Technology Data Exchange (ETDEWEB)

    Busold, S., E-mail: s.busold@gsi.de [Institut für Kernphysik, Technische Universität Darmstadt, Schloßgartenstraße 9, D-64289 Darmstadt (Germany); Almomani, A. [Institut für angewandte Physik, Johann-Wolfgang-Goethe-Universität Frankfurt, Max von Laue Straße 1, D-60438 Frankfurt (Germany); Bagnoud, V. [GSI Helmholtzzentrum für Schwerionenforschung, Planckstraße 1, D-64291 Darmstadt (Germany); Helmholtz Institut Jena, Fröbelstieg 3, D-07734 Jena (Germany); Barth, W. [GSI Helmholtzzentrum für Schwerionenforschung, Planckstraße 1, D-64291 Darmstadt (Germany); Bedacht, S. [Institut für Kernphysik, Technische Universität Darmstadt, Schloßgartenstraße 9, D-64289 Darmstadt (Germany); Blažević, A. [GSI Helmholtzzentrum für Schwerionenforschung, Planckstraße 1, D-64291 Darmstadt (Germany); Helmholtz Institut Jena, Fröbelstieg 3, D-07734 Jena (Germany); Boine-Frankenheim, O. [GSI Helmholtzzentrum für Schwerionenforschung, Planckstraße 1, D-64291 Darmstadt (Germany); Institut für Theorie Elektromagnetischer Felder, Technische Universität Darmstadt, Schloßgartenstraße 8, D-64289 Darmstadt (Germany); and others

    2014-03-11

    The generation of intense ion beams from high-intensity laser-generated plasmas has been the focus of research for the last decade. In the LIGHT collaboration the expertise of heavy ion accelerator scientists and laser and plasma physicists has been combined to investigate the prospect of merging these ion beams with conventional accelerator technology and exploring the possibilities of future applications. We report about the goals and first results of the LIGHT collaboration to generate, handle and transport laser driven ion beams. This effort constitutes an important step in research for next generation accelerator technologies.

  1. Quantitative Probing of Cu(2+) Ions Naturally Present in Single Living Cells.

    Science.gov (United States)

    Lee, Junho; Lee, Hwa-Rim; Pyo, Jaeyeon; Jung, Youngseob; Seo, Ji-Young; Ryu, Hye Guk; Kim, Kyong-Tai; Je, Jung Ho

    2016-06-01

    Quantitative probing of Cu(2+) ions naturally present in single living cells is realized by developing a quantum-dot-embedded nanowire-waveguide probe. The intracellular Cu(2+) ion concentration is quantified by direct monitoring of photoluminescence quenching during the insertion of the nanowire in a living neuron. The measured intracellular Cu(2+) ion concentration is 3.34 ± 1.04 × 10(-6) m (mean ± s.e.m.) in single hippocampal neurons.

  2. Photons shedding light on electron capture by highly charged ions

    NARCIS (Netherlands)

    Hoekstra, Romke Anne

    1990-01-01

    In this thesis charge transfer is studied in collisions of highly charged ions (Aq+) with neutral particles (B). Because the electron is captured resonantly (i.e. without its binding energy) by the ion, a limited number of highly excited states (characterized by the quantum numbers nlm) is preferent

  3. Photons shedding light on electron capture by highly charged ions

    NARCIS (Netherlands)

    Hoekstra, Romke Anne

    1990-01-01

    In this thesis charge transfer is studied in collisions of highly charged ions (Aq+) with neutral particles (B). Because the electron is captured resonantly (i.e. without its binding energy) by the ion, a limited number of highly excited states (characterized by the quantum numbers nlm) is

  4. Fast ion collective Thomson scattering - present results and plans for ITER

    DEFF Research Database (Denmark)

    Korsholm, Søren Bang; Bindslev, Henrik; Furtula, Vedran;

    scattering (CTS) provides the possibility of revealing the velocity distribution of the confined fast ions along a given direction – resolved both in time and space. Recently, the ITER baseline design has been expanded to include a fast ion CTS diagnostic. The design of this diagnostic was provided...... and results, and present the expectations for the ITER CTS diagnostic....

  5. Temperature behavior of damage in sapphire implanted with light ions

    Energy Technology Data Exchange (ETDEWEB)

    Alves, E. [Ion Beam Laboratory, Instituto Tecnologico e Nuclear, Sacavem 2686-953 (Portugal); Centro de Fisica Nuclear da Universidade de Lisboa, Lisbon (Portugal)], E-mail: ealves@itn.pt; Marques, C. [Ion Beam Laboratory, Instituto Tecnologico e Nuclear, Sacavem 2686-953 (Portugal); Centro de Fisica Nuclear da Universidade de Lisboa, Lisbon (Portugal); Safran, G. [Research Institute for Technical Physics and Materials Science, H-1525 Budapest (Hungary); McHargue, Carl J. [University of Tennessee, Knoxville, TN 37996-0750 (United States)

    2009-05-01

    In this study, we compare and discuss the defect behavior of sapphire single crystals implanted with different fluences (1 x 10{sup 16}-1 x 10{sup 17} cm{sup -2}) of carbon and nitrogen with 150 keV. The implantation temperatures were RT, 500 deg. C and 1000 deg. C to study the influence of temperature on the defect structures. For all the ions the Rutherford backscattering-channeling (RBS-C) results indicate a surface region with low residual disorder in the Al-sublattice. Near the end of range the channeled spectrum almost reaches the random indicating a high damage level for fluences of 1 x 10{sup 17} cm{sup -2}. The transmission electron microscopy (TEM) photographs show a layered contrast feature for the C implanted sample where a buried amorphous region is present. For the N implanted sample the Electron Energy Loss Spectroscopy (EELS) elemental mapping give evidence for the presence of a buried damage layer decorated with bubbles. Samples implanted at high temperatures (500 deg. C and 1000 deg. C) show a strong contrast fluctuation indicating a defective crystalline structure of sapphire.

  6. CNAO--The Italian Centre for Light-Ion Therapy.

    Science.gov (United States)

    Amaldi, Ugo

    2004-12-01

    In 1991 the author involved the Italian institute of nuclear physics (INFN) in R&D work in the field of hadrontherapy. In 1992 the TERA Foundation was created with the purpose of forming and employing people fully devoted to the design, promotion and construction of hadrontherapy centres in Italy and in Europe. The present contribution describes the main project of TERA, the CNAO (Centro Nazionale di Adroterapia Oncologica), and the status of its construction in Pavia. The Italian Centre is based on the optimised medical synchrotron designed in the framework of the "Proton Ion Medical Machine Study" (PIMMS) carried out at CERN from 1996 to 2000 with CERN, the Med-AUSTRO project, Oncology 2000 (Prague) and TERA as partners. In the following years TERA introduced modifications and improvements in the original PIMMS design producing what is now dubbed the PIMMS/TERA design. Since 2001 the construction of CNAO has been endorsed by the Italian government to the CNAO Foundation formed by five major hospitals, seated in Milan and Pave, and by TERA. Since 2003 INFN is an Institutional Participant. The site chosen at the beginning of 2003 (37,000 m2) is in the close vicinities of one of the five hospitals, the San Matteo University Hospital of Pave. The construction plan foresees the treatment of the first patient at the end of 2007.

  7. Microsecond pulse width, intense, light-ion beam accelerator

    Science.gov (United States)

    Rej, D. J.; Bartsch, R. R.; Davis, H. A.; Faehl, R. J.; Greenly, J. B.; Waganaar, W. J.

    1993-10-01

    A relatively long-pulse width (0.1-1 μs) intense ion beam accelerator has been built for materials processing applications. An applied Br, magnetically insulated extraction ion diode with dielectric flashover ion source is installed directly onto the output of a 1.2 MV, 300-kJ Marx generator. The diode is designed with the aid of multidimensional particle-in-cell simulations. Initial operation of the accelerator at 0.4 MV indicates satisfactory performance without the need for additional pulse shaping. The effect of a plasma opening switch on diode behavior is considered.

  8. Ultraviolet Photodissociation Induced by Light-Emitting Diodes in a Planar Ion Trap.

    Science.gov (United States)

    Holden, Dustin D; Makarov, Alexander; Schwartz, Jae C; Sanders, James D; Zhuk, Eugene; Brodbelt, Jennifer S

    2016-09-26

    The first application of light-emitting diodes (LEDs) for ultraviolet photodissociation (UVPD) mass spectrometry is reported. LEDs provide a compact, low cost light source and have been incorporated directly into the trapping cell of an Orbitrap mass spectrometer. MS/MS efficiencies of over 50 % were obtained using an extended irradiation period, and UVPD was optimized by modulating the ion trapping parameters to maximize the overlap between the ion cloud and the irradiation volume.

  9. Light-fronts approach to electron-positron pair production in ultrarelativistic heavy-ion collisions

    Energy Technology Data Exchange (ETDEWEB)

    Wells, J.C. [Oak Ridge National Lab., TN (United States). Center for Computational Sciences; Segev, B. [Harvard-Smithsonian Center for Astrophysics, Cambridge, MA (United States). Inst. for Theoretical Atomic and Molecular Physics

    1998-03-01

    The authors solve, in an ultrarelativistic limit, the time-dependent Dirac equation describing electron-positron pair production in peripheral relativistic heavy ion collisions using light front variables and a light-fronts representation, obtaining nonperturbative results for the free pair-creation amplitudes in the collider frame. Their result reproduces the result of second-order perturbation theory in the small charge limit while nonperturbative effects arise for realistic charges of the ions.

  10. Light-by-light scattering in ultraperipheral heavy-ion collisions at the LHC

    CERN Document Server

    Szczurek, Antoni; Lebiedowicz, Piotr

    2016-01-01

    We present cross sections for diphoton production in (semi)exclusive $PbPb$ collisions, relevant for the LHC. The calculation is based on equivalent photon approximation in the impact parameter space. The cross sections for elementary elastic scattering $\\gamma \\gamma \\to \\gamma \\gamma$ subprocess are calculated including two mechanisms: box diagrams with leptons and quarks in the loops and a mechanism based on vector-meson dominance (VDM-Regge) model with virtual intermediate vector-like excitations of the photons. We get measureable cross sections in $PbPb$ collisions. We present many interesting differential distributions which could be measured by the ALICE, CMS or ATLAS Collaborations at the LHC. We study whether a separation of box and VDM-Regge contributions is possible. We find that the cross section for elastic $\\gamma \\gamma$ scattering could be measured in the heavy-ion collisions for subprocess energies smaller than $W_{\\gamma\\gamma} \\approx 15-20$~GeV.

  11. Light emission of a polyfluorene derivative containing complexed europium ions.

    Science.gov (United States)

    Turchetti, Denis Augusto; Nolasco, Mariela Martins; Szczerbowski, Daiane; Carlos, Luís Dias; Akcelrud, Leni Campos

    2015-10-21

    The photophysical properties of a new alternating copolymer containing fluorene, terpyridine, and complexed sites with trivalent europium (Eu(3+)) ions (LaPPS66Eu) were investigated, using the non-complexed backbone (LaPPS66) and a low molecular weight compound of similar chemical structure of the ligand/Eu(3+) site (LaPPS66M) as a model compound. The analogous gadolinium complex (LaPPS66Gd) was also synthesized to determine the triplet state of the complex. (1)H and (13)C nuclear magnetic resonance (NMR) analysis, Fourier transform infrared (FT-IR) spectroscopy, inductively coupled plasma optical emission spectroscopy (ICP-OES), elemental analyses, differential scanning calorimetry (DSC), and thermogravimetric analysis (TGA) characterized the chemical structure and thermal properties of the synthesized materials. A level of Eu(3+) insertion of 37% (molar basis) in the polymer backbone was achieved. The photoluminescence studies were performed in the solid state showing the occurrence of polymer-to-Eu(3+) energy transfer brought about by the spectral overlap between the absorption spectra of the Eu(3+) complex and the emission of the polymer backbone. A detailed theoretical photoluminescence study performed using time-dependent DFT (TD-DFT) calculations and the recently developed LUMPAC luminescence package is also presented. The high accuracy of the theoretical calculations was achieved on comparison with the experimental values. Aiming at a deeper level of understanding of the photoluminescence process, the ligand-to-Eu(3+) intramolecular energy transfer and back-transfer rates were predicted. The complexed materials showed a dominant pathway involving the energy transfer between the triplet of the dbm (dibenzoylmethane) ligand and the (5)D1 and (5)D0 Eu(3+) levels.

  12. Hydroxyl radicals cause fluctuation in intracellular ferrous ion levels upon light exposure during photoreceptor cell death.

    Science.gov (United States)

    Imamura, Tomoyo; Hirayama, Tasuku; Tsuruma, Kazuhiro; Shimazawa, Masamitsu; Nagasawa, Hideko; Hara, Hideaki

    2014-12-01

    Iron accumulation is a potential pathogenic event often seen in age-related macular degeneration (AMD) patients. In this study, we focused on the relationship between AMD pathology and concentrations of ferrous ion, which is a highly reactive oxygen generator in biological systems. Murine cone-cells-derived 661 W cells were exposed to white fluorescence light at 2500 lx for 1, 3, 6, or 12 h. Levels of ferrous ions, reactive oxygen species (ROS), and hydroxyl radicals were detected by RhoNox-1, a novel fluorescent probe for the selective detection of ferrous ion, 5-(and-6)-chloromethyl-2',7'-dichlorodihydrofluorescein diacetate, acetyl ester (CM-H2DCFDA), and 3'-p-(aminophenyl) fluorescein, respectively. Reduced glutathione, total iron levels and photoreceptor cell death were also measured. Two genes related to iron metabolism, transferrin receptor 1 (TfR1) and H ferritin (HFt), were quantified by RT-PCR. The effects of ferrous ion on cell death and hydroxyl radical production were determined by treatment with a ferrous ion chelating agent, 2,2'-bipyridyl. We found that the ferrous ion level decreased with light exposure in the short time frame, whereas it was upregulated during a 6-h light exposure. Total iron, ROS, cell death rate, and expression of TfR and HFt genes were significantly increased in a time-dependent manner in 661 W cells exposed to light. Chelation with 2,2'-bipyridyl reduced the level of hydroxyl radicals and protected against light-induced cell death. These results suggest that light exposure decreases ferrous ion levels and enhances iron uptake in photoreceptor cells. Ferrous ion may be involved in light-induced photoreceptor cell death through production of hydroxyl radicals. Copyright © 2014 Elsevier Ltd. All rights reserved.

  13. Relativistic Tennis with Photons: Frequency Up-Shifting, Light Intensification and Ion Acceleration with Flying Mirrors

    Science.gov (United States)

    Bulanov, S. V.; Esirkepov, T. Zh.; Kando, M.; Koga, J. K.; Pirozhkov, A. S.; Rosanov, N. N.; Zhidkov, A. G.

    2011-01-01

    We formulate the Flying Mirror Concept for relativistic interaction of ultra-intense electromagnetic waves with plasmas, present its theoretical description and the results of computer simulations and laboratory experiments. In collisionless plasmas, the relativistic flying mirrors are thin and dense electron or electron-ion layers accelerated by the high intensity electromagnetic waves up to velocity close to the speed of light in vacuum; in nonlinear-media and in nonlinear vacuum they are the ionization fronts and the refraction index modulations induced by a strong electromagnetic wave. The reflection of the electromagnetic wave at the relativistic mirror results in its energy and frequency change due to the double Doppler effect. In the co-propagating configuration, in the radiation pressure dominant regime, the energy of the electromagnetic wave is transferred to the ion energy providing a highly efficient acceleration mechanism. In the counter-propagation configuration the frequency of the reflected wave is multiplied by the factor proportional to the gamma-factor squared. If the relativistic mirror performs an oscillatory motion as in the case of the electron motion at the plasma-vacuum interface, the reflected light spectrum is enriched with high order harmonics.

  14. Cooling atomic ions with visible and infra-red light

    CERN Document Server

    Lindenfelser, F; Negnevitsky, V; Ragg, S; Home, J P

    2016-01-01

    We demonstrate the ability to load, cool and detect singly-charged calcium ions in a surface electrode trap using only visible and infrared lasers for the trapped-ion control. As opposed to the standard methods of cooling using dipole-allowed transitions, we combine power broadening of a quadrupole transition at 729 nm with quenching of the upper level using a dipole allowed transition at 854 nm. By observing the resulting 393 nm fluorescence we are able to perform background-free detection of the ion. We show that this system can be used to smoothly transition between the Doppler cooling and sideband cooling regimes, and verify theoretical predictions throughout this range. We achieve scattering rates which reliably allow recooling after collision events and allow ions to be loaded from a thermal atomic beam. This work is compatible with recent advances in optical waveguides, and thus opens a path in current technologies for large-scale quantum information processing. In situations where dielectric materials...

  15. EPA Presentation Regarding the Advanced Light-Duty Powertrain and Hybrid Analysis (ALPHA) Tool

    Science.gov (United States)

    This page contains a selection of the presentations that EPA has publicly presented about our work on the Midterm Evaluation (MTE). It highlights EPA's benchmarking and modeling activities relating to light duty greenhouse gas (GHG) emissions.

  16. Visible Light Photocatalysis: The Development of Photocatalytic Radical Ion Cycloadditions.

    Science.gov (United States)

    Yoon, Tehshik P

    2013-05-03

    Photochemistry has the potential to significantly impact multiple aspects of chemical synthesis, in part because photoinduced reactions can be used to construct molecular architectures that would otherwise be difficult to produce. Nevertheless, organic chemists have been slow to embrace photochemical synthesis because of technical complications associated with the use of ultraviolet light. Our laboratory has been part of an effort to design synthetically useful reactions that utilize visible light. This strategy enables the synthesis of a diverse range of organic structures by generation of a variety of reactive intermediates under exceptionally mild conditions. This Perspective article describes the reasoning that led to the conception of our first experiments in this area, the features of our reaction design that have been most powerful in the discovery of new processes, and a few of the possible future areas in which visible light photocatalysis might have a large impact.

  17. Ion implantation, a method for fabricating light guides in polymers

    Science.gov (United States)

    Kulish, J. R.; Franke, H.; Singh, Amarjit; Lessard, Roger A.; Knystautas, Emile J.

    1988-04-01

    Li+ and N+ ions were implanted into aliphatic polymethylmethacrylate (PMMA), polyvinylalcohol (PVA), and aromatic polyimide (PI) polycarbonate (PC) polymers in the energy range of 100-130 keV. Planar optical waveguides guiding between one and three modes were formed. For low implantation doses (≤ 1014 ions/cm2), total waveguide loss values at λ=633 nm were found to be less than 2 dB/cm. The changes in the refractive index were found to be very large (Δn≥0.05) in the case of PMMA and PVA. We interpret this change in refractive index as being due to the formation of aromatic compounds in the regions of electronic scattering.

  18. Light

    DEFF Research Database (Denmark)

    Prescott, N.B.; Kristensen, Helle Halkjær; Wathes, C.M.

    2004-01-01

    This chapter presents the effect of artificial light environments (light levels, colour, photoperiod and flicker) on the welfare of broilers in terms of vision, behaviour, lameness and mortality......This chapter presents the effect of artificial light environments (light levels, colour, photoperiod and flicker) on the welfare of broilers in terms of vision, behaviour, lameness and mortality...

  19. Analysis of light-induced transmembrane ion gradients and membrane potential in Photosystem I proteoliposomes.

    Science.gov (United States)

    Pennisi, Cristian Pablo; Greenbaum, Elias; Yoshida, Ken

    2010-01-01

    Photosystem I (PSI) complexes can support a light-driven electrochemical gradient for protons, which is the driving force for energy-conserving reactions across biological membranes. In this work, a computational model that enables a quantitative description of the light-induced proton gradients across the membrane of PSI proteoliposomes is presented. Using a set of electrodiffusion equations, a compartmental model of a vesicle suspended in aqueous medium was studied. The light-mediated proton movement was modeled as a single proton pumping step with backpressure of the electric potential. The model fits determinations of pH obtained from PSI proteoliposomes illuminated in the presence of mediators of cyclic electron transport. The model also allows analysis of the proton gradients in relation to the transmembrane ion fluxes and electric potential. Sensitivity analysis enabled a determination of the parameters that have greater influence on steady-state levels and onset/decay rates of transmembrane pH and electric potential. This model could be used as a tool for optimizing PSI proteoliposomes for photo-electrochemical applications.

  20. Analysis of Light-Induced Transmembrane Ion Gradients and Membrane Potential in Photosystem I Proteoliposomes

    Energy Technology Data Exchange (ETDEWEB)

    Pennisi, Cristian P. [Aalborg University, Aalborg, Denmark; Greenbaum, Elias [ORNL; Yoshida, Ken [Aalborg University, Aalborg, Denmark

    2010-01-01

    Photosystem I (PSI) complexes can support a light-driven electrochemical gradient for protons, which is the driving force for energy-conserving reactions across biological membranes. In this work, a computational model that enables a quantitative description of the light-induced proton gradients across the membrane of PSI proteoliposomes is presented. Using a set of electrodiffusion equations, a compartmental model of a vesicle suspended in aqueous medium was studied. The light-mediated proton movement was modeled as a single proton pumping step with backpressure of the electric potential. The model fits determinations of pH obtained from PSI proteoliposomes illuminated in the presence of mediators of cyclic electron transport. The model also allows analysis of the proton gradients in relation to the transmembrane ion fluxes and electric potential. Sensitivity analysis enabled a determination of the parameters that have greater influence on steady-state levels and onset/decay rates of transmembrane pH and electric potential. This model could be used as a tool for optimizing PSI proteoliposomes for photo-electrochemical applications.

  1. Ferric ion mediated photochemical decomposition of perfluorooctanoic acid (PFOA) by 254 nm UV light

    Energy Technology Data Exchange (ETDEWEB)

    Wang Yuan [State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Science, Chinese Academy of Science, Beijing 100085 (China); Department of Environmental Science and Engineering, Tsinghua University, Beijing 100084 (China); Zhang Pengyi [Department of Environmental Science and Engineering, Tsinghua University, Beijing 100084 (China)], E-mail: zpy@tsinghua.edu.cn; Pan Gang; Chen Hao [State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Science, Chinese Academy of Science, Beijing 100085 (China)

    2008-12-15

    The great enhancement of ferric ion on the photochemical decomposition of environmentally persistent perfluorooctanoic acid (PFOA) under 254 nm UV light was reported. In the presence of 10 {mu}M ferric ion, 47.3% of initial PFOA (48 {mu}M) was decomposed and the defluorination ratio reached 15.4% within 4 h reaction time. While the degradation and defluorination ratio greatly increased to 80.2% and 47.8%, respectively, when ferric ion concentration increased to 80 {mu}M, and the corresponding half-life was shortened to 103 min. Though the decomposition rate was significantly lowered under nitrogen atmosphere, PFOA was efficiently decomposed too. Other metal ions like Cu{sup 2+} and Zn{sup 2+} also slightly improved the photochemical decomposition of PFOA under irradiation of 254 nm UV light. Besides fluoride ion, other intermediates during PFOA decomposition including formic acid and five shorter-chain perfluorinated carboxylic acids (PFCAs) with C7, C6, C5, C4 and C3, respectively, were identified and quantified by IC or LC/MS. The mixture of PFOA and ferric ion had strong absorption around 280 nm. It is proposed that PFOA coordinates with ferric ion to form a complex, and its excitation by 254 nm UV light leads to the decomposition of PFOA in a stepwise way.

  2. ECR Light Ion Sources at CEA/Saclay%CEA/Saclay的ECR轻离子离子源

    Institute of Scientific and Technical Information of China (English)

    R.Gobin; P-A.Leroy; O.Tuske; D.Uriot; P-Y.Beauvais; A.Ben Ismail; D.Bogard; O.Delferriere; D.de Menezes; R.Duperrier; Y.Gauthier; F.Harrault

    2007-01-01

    In the beginning of the 90s,T.Taylor and his collaborators demonstrated ECR sources operating at low frequency (I.e.2.45GHz) are able to produce very intense single charge light ion beams.At CEA/Saclay,the SILHI source developments started in 1995.Since 1997 more than 100mA proton or deuteron beams are routinely produced in pulsed or continuous mode.To comply with ADS reliability constraint,important improvements have been performed to increase the installation reliability.Moreover,to optimize the beam transport in the low energy beam line,the extraction system was carefully designed and space charge compensation studies were undertaken.An important step has been reached in 2005 with the development of a permanent magnet source able to produce a total beam of 109mA at 85kV.A new test bench named BETSI,especially dedicated to permanent magnet source developments,is presently under construction.It will allow analysing positive or negative extracted beams up to 50keV and 100mA.In addition,for several years work has been done to optimize the production of negative hydrogen ion beam with such an ECR source.Recent analysis pushed towards the construction of a new set up based on a multicusp magnetic configuration.After a brief overview of the CEA/Saclay source developments,this article will point out on the recent results and present status.

  3. Improved charge breeding efficiency of light ions with an electron cyclotron resonance ion source

    Energy Technology Data Exchange (ETDEWEB)

    Vondrasek, R.; Kutsaev, Sergey [Argonne National Laboratory, Argonne, Illinois 60439 (United States); Delahaye, P.; Maunoury, L. [Grand Accelerateur National d' Ions Lourds (GANIL), CEA/DSM-CNRS/IN2P3, Blvd Henri Becquerel, 14076 Caen (France)

    2012-11-15

    The Californium Rare Isotope Breeder Upgrade is a new radioactive beam facility for the Argonne Tandem Linac Accelerator System (ATLAS). The facility utilizes a {sup 252}Cf fission source coupled with an electron cyclotron resonance ion source to provide radioactive beam species for the ATLAS experimental program. The californium fission fragment distribution provides nuclei in the mid-mass range which are difficult to extract from production targets using the isotope separation on line technique and are not well populated by low-energy fission of uranium. To date the charge breeding program has focused on optimizing these mid-mass beams, achieving high charge breeding efficiencies of both gaseous and solid species including 14.7% for the radioactive species {sup 143}Ba{sup 27+}. In an effort to better understand the charge breeding mechanism, we have recently focused on the low-mass species sodium and potassium which up to present have been difficult to charge breed efficiently. Unprecedented charge breeding efficiencies of 10.1% for {sup 23}Na{sup 7+} and 17.9% for {sup 39}K{sup 10+} were obtained injecting stable Na{sup +} and K{sup +} beams from a surface ionization source.

  4. Independent-particle models for light negative atomic ions

    Science.gov (United States)

    Ganas, P. S.; Talman, J. D.; Green, A. E. S.

    1980-01-01

    For the purposes of astrophysical, aeronomical, and laboratory application, a precise independent-particle model for electrons in negative atomic ions of the second and third period is discussed. The optimum-potential model (OPM) of Talman et al. (1979) is first used to generate numerical potentials for eight of these ions. Results for total energies and electron affinities are found to be very close to Hartree-Fock solutions. However, the OPM and HF electron affinities both depart significantly from experimental affinities. For this reason, two analytic potentials are developed whose inner energy levels are very close to the OPM and HF levels but whose last electron eigenvalues are adjusted precisely with the magnitudes of experimental affinities. These models are: (1) a four-parameter analytic characterization of the OPM potential and (2) a two-parameter potential model of the Green, Sellin, Zachor type. The system O(-) or e-O, which is important in upper atmospheric physics is examined in some detail.

  5. Light-Weight, Low-Cost, Single-Phase, Liquid-Cooled Cold Plate (Presentation)

    Energy Technology Data Exchange (ETDEWEB)

    Narumanchi, S.

    2013-07-01

    This presentation, 'Light-Weight, Low-Cost, Single-Phase Liquid-Cooled Cold Plate,' directly addresses program goals of increased power density, specific power, and lower cost of power electronics components through improved thermal management.

  6. Light-Induced Ion Rectification in Zigzag Nanochannels.

    Science.gov (United States)

    Li, Chuanshuai; Hu, Shimin; Yang, Lei; Fan, Jiajie; Yao, Zhiqiang; Zhang, Yiqiang; Shao, Guosheng; Hu, Junhua

    2015-12-01

    Ion transport through nanoporous systems has attracted broad interest due to its crucial role in physiological processes in living organisms and artificial bionic devices. In this work, a nanochannel system with a zigzag inner surface was fabricated by using a two-step anodizing technique. The rectification performance of the zigzag channels was observed by I-V measurement in KCl solution. Unlike channels with asymmetric geometry, the mechanism was analyzed based on the "point effect" of charge distribution and "shape effect" of the zigzag channel. The current rectification ratio decreases from nearly 3.0 to 1.0 when the KCl concentration increased from 0.1 mM to 100 mM. The fabrication of different nanopore systems and exploration of novel mechanisms will help to develop biomimetic membranes for practical applications.

  7. A novel sensor of potassium ions based on mode-filtered light detection

    Institute of Scientific and Technical Information of China (English)

    Xiao Hong Zhao; Li Ping Yang; Suo Zhu Wu; Wen Ping Cheng; Shao Min Shuang; Chuan Dong

    2010-01-01

    A novel potassium ions sensor based on mode-filtered light detection was reported.The analyzer was consisting of an optical fiber immobilized with a dye of bromocresol green and a fused-silica capillary.It was found that mode-filtered light intensity decreased with the concentration of potassium ions and a linear detection range of 0.25-20 mmol/L(R2 = 0.9977)was obtained with a detection limit of 9 × 10-5 mol/L as well as fast response,good reproducibility and reversibility in the working concentration range.

  8. Heavy ions light flashes and brain functions: recent observations at accelerators and in spaceflight

    Science.gov (United States)

    Narici, L.

    2008-07-01

    Interactions between ionizing radiation in space and brain functions, and the related risk assessments, are among the major concerns when programming long permanence in space, especially when outside the protective shield of the Earth's magnetosphere. The light flashes (LF) observed by astronauts in space, mostly when dark adapted, are an example of these interactions; investigations in space and on the ground showed that these effects can originate with the action of ionizing radiation in the eye. Recent findings from ALTEA, an interdisciplinary and multiapproach program devoted to the study of different aspects of the radiation-brain functions interaction, are presented in this paper. These include: (i) study of radiation passing through the astronauts' eyes in the International Space Station (≈20 ions min-1, excluding H and fast and very slow He), measured in conjunction with reporting of the perception of LF; (ii) preliminary electrophysiological evidence of these events in astronauts and in patients during heavy ion therapy; and (iii) in vitro results showing the radiation driven activation of rhodopsin at the start of the phototransduction cascade in the process of vision. These results are in agreement with our previous work on mice. A brief but complete summary of the earlier works is also reported to permit a discussion of the results.

  9. Light charged particle emission in heavy-ion reactions – What have we learnt?

    Indian Academy of Sciences (India)

    S Kailas

    2001-07-01

    Light charged particles emitted in heavy-ion induced reactions, their spectra and angular distributions measured over a range of energies, carry the signature of the underlying reaction mechanisms. Analysis of data of light charged particles, both inclusive and exclusive measured in coincidence with gamma rays, fission products, evaporation residues have yielded interesting results which bring out the influence of nuclear structure, nuclear mean field and dynamics on the emission of these particles.

  10. Excitation of heavy hydrogen-like ions by light atoms in relativistic collisions with large momentum transfers

    CERN Document Server

    Najjari, B

    2012-01-01

    We present a theory for excitation of heavy hydrogen-like projectile-ions by light target-atoms in collisions where the momentum transfers to the atom are very large on the atomic scale. It is shown that in this process the electrons and the nucleus of the atom behave as (quasi-) free particles with respect to each other and that their motion is governed by the field of the nucleus of the ion. The effect of this field on the atomic particles can be crucial for the contribution to the excitation of the ion caused by the electrons of the atom. Due to comparatively very large nuclear mass, however, this field can be neglected in the calculation of the contribution to the excitation due to the nucleus of the atom.

  11. Polarized light ions and spectator nucleon tagging at EIC

    Energy Technology Data Exchange (ETDEWEB)

    Guzey, Vadim [Petersburg Nuclear Physics Institute, Gatchina, 188300, Russia; Higinbotham, Dougas W. [JLAB; Hyde, Charles [Old Dominion University, Norfolk, VA 23529, USA; Nadel-Turonski, Pawel A. [JLAB; Park, Kijun [Old Dominion University, Norfolk, VA 23529, USA; Sargsian, Misak M. [Florida International University, Miami, FL 33199, USA; Strikman, Mark [Pennsylvania State University, University Park, PA 16802, USA; Weiss, Christian [JLAB

    2014-10-01

    The neutron's deep-inelastic structure functions provide essential information for the flavor separation of the nucleon parton densities, the nucleon spin decomposition, and precision studies of QCD phenomena in the flavor-singlet and nonsinglet sectors. Traditional inclusive measurements on nuclear targets are limited by dilution from scattering on protons, Fermi motion and binding effects, final-state interactions, and nuclear shadowing at x ll 0.1. An Electron-Ion Collider (EIC) would enable next-generation measurements of neutron structure with polarized deuteron beams and detection of forward-moving spectator protons over a wide range of recoil momenta (0 < p(R) < several 100MeV in the nucleus rest frame). The free neutron structure functions could be obtained by extrapolating the measured recoil momentum distributions to the on-shell point. The method eliminates nuclear modifications and can be applied to polarized scattering, as well as to semi-inclusive and exclusive final states. We review the prospects for neutron structure measurements with spectator tagging at EIC, the status of R&D efforts, and the accelerator and detector requirements.

  12. Light distribution properties in spinal cord for optogenetic stimulation (Conference Presentation)

    Science.gov (United States)

    GÄ secka, Alicja; Bahdine, Mohamed; Lapointe, Nicolas; Rioux, Veronique; Perez-Sanchez, Jimena; Bonin, Robert P.; De Koninck, Yves; Côté, Daniel

    2016-03-01

    Optogenetics is currently one of the most popular technique in neuroscience. It enables cell-selective and temporally-precise control of neuronal activity. Good spatial control of the stimulated area and minimized tissue damage requires a specific knowledge about light scattering properties. Light propagation in cell cultures and brain tissue is relatively well documented and allows for a precise and reliable delivery of light to the neurons. In spinal cord, light must pass through highly organized white matter before reaching cell bodies present in grey matter, this heterogenous structure makes it difficult to predict the propagation pattern. In this work we investigate the light distribution properties through mouse and monkey spinal cord. The light propagation depends on a fibers orientation, leading to less deep penetration profile in the direction perpendicular to the fibers and lower attenuation in the direction parallel to the fibers. Additionally, the use of different illumination wavelengths results in variations of the attenuation coefficient. Next, we use Monte-Carlo simulation to study light transport. The model gives a full 3-D simulation of light distribution in spinal cord and takes into account different scattering properties related to the fibers orientation. These studies are important to estimate the minimum optical irradiance required at the fiber tip to effectively excite the optogenetic proteins in a desired region of spinal cord.

  13. Fusion at the barrier with light radioactive ion beams

    CERN Document Server

    Signorini, C

    2001-01-01

    The experimental results recently obtained for fusion reactions at energies close to the Coulomb barrier with light radioactive (loosely bound) beams are reviewed and critically discussed. There have been two conflicting views on the effect of the loose binding of the projectile on the fusion cross section. On the one hand one expects an enhancement of the fusion cross section due to the loose binding while, on the other hand, the easy breakup of the projectile is expected to inhibit the fusion cross section. We critically discuss these two aspects of loose binding by comparing the experimental results for a number of radioactive beams. The data for sup 1 sup 7 F (where the last neutron binding energy S sub n =0.601 MeV), neither show breakup effects nor enhancement when compared with the fusion of the nucleus sup 1 sup 9 F. The data for a sup 6 He beam (S sub 2 sub n =0.975 MeV) show enhancement, very strong in one case, and the strong breakup (BU)+transfer cross section may be related to this. The fusion da...

  14. Light ion EDM search in magnetic storage rings

    NARCIS (Netherlands)

    Onderwater, C. J. G.

    2006-01-01

    Permanent electric dipole moments (EDMs) violate parity and time-reversal symmetry. Within the Standard Model (SM), they require CP violation and are many orders of magnitude below present experimental sensitivity. Many extensions of the SM predict much larger EDMs, which are therefore an excellent

  15. Dynamics of light, intermediate, heavy and superheavy nuclear systems formed in heavy-ion collisions

    Indian Academy of Sciences (India)

    Manoj K Sharma; Gurvinder Kaur

    2014-05-01

    The dynamical description of light, intermediate, heavy and superheavy nuclei formed in heavy-ion collisions is worked out using the dynamical cluster decay model (DCM), with reference to various effects such as deformation and orientation, temperature, angular momentum etc. Based on the quantum mechanical fragmentation theory (QMFT), DCM has been applied to understand the decay mechanism of a large number of nuclei formed in low-energy heavy-ion reactions. Various features related to the dynamics of competing decay modes of nuclear systems are explored by addressing the experimental data of a number of reactions in light, intermediate, heavy and superheavy mass regions. The DCM, being a non-statistical description for the decay of a compound nucleus, treats light particles (LPs) or equivalently evaporation residues (ERs), intermediate mass fragments (IMFs) and fission fragments on equal footing and hence, provides an alternative to the available statistical model approaches to address fusion–fission and related phenomena.

  16. Preferential heating of light ions during an ionospheric Ar(+) injection experiment

    Science.gov (United States)

    Pollock, C. J.; Chandler, M. O.; Moore, T. E.; Arnoldy, R. L.; Kintner, P. M.; Chesney, S.; Cahill, L. J., Jr.

    1995-01-01

    The Argon Release for Controlled Studies (ARCS) 4 sounding rocket was launched northward into high altitude from Poker Flat Research Range on February 23, 1990. The vehicle crossed geomagnetic field lines containing discrete auroral activity. An instrumented subpayload released 100-eV and 200-eV Ar(+) ion beams sequentially, in a direction largely perpendicular to both the local geomagnetic field and the subpayload spin axis. The instrumented main payload was separated along field lines from the beam emitting subpayload by a distance which increased at a steady rate of approximately 2.4 m/s. Three dimensional mass spectrometric ion observations of ambient H(+) and O(+) ions, obtained on board the main payload, are presented. Main payload electric field observations in the frequency range 0-16 kHz, are also presented. These observations are presented to demonstrate the operation of transverse ion acceleration, which was differential with respect to ion mass, primarily during 100-eV beam operations. The preferential transverse acceleration of ambient H(+) ions, as compared with ambient O(+) ions, during the second, third, fourth, and fifth 100-eV beam operations, is attributed to a resonance among the injected Ar(+) ions, beam-generated lower hybrid waves, and H(+) ions in the tail of the ambient thermal distribution. This work provides experimental support of processes predicted by previously published theory and simulations.

  17. Heavy ion irradiation effects of polymer film on absorption of light

    Energy Technology Data Exchange (ETDEWEB)

    Kasai, Noboru; Seguchi, Tadao [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment; Arakawa, Tetsuhito

    1997-03-01

    Ion irradiation effects on the absorption of light for three types of polymer films; polyethylene-terephthalate (PET), polyethylene-naphthalate (PEN), and polyether-ether-ketone (PEEK) were investigated by irradiation of heavy ions with Ni{sup 4+}(15MeV), O{sup 6+}(160MeV), and Ar{sup 8+}(175MeV), and compared with electron beams(EB) irradiation. The change of absorption at 400nm by a photometer was almost proportional to total dose for ions and EB. The absorption per absorbed dose was much high in Ni{sup 4+}, but rather small in O{sup 6+} and Ar{sup 8+} irradiation, and the absorption by EB irradiation was accelerated by the temperature of polymer film during irradiation. The beam heating of materials during ion irradiation was assumed, especially for Ni ion irradiation. The heavy ion irradiation effect of polymers was thought to be much affected by the ion beam heating than the linear energy transfer(LET) of radiation source. (author)

  18. Collective effects in light-heavy ion collisions

    CERN Document Server

    Schenke, Bjoern

    2014-01-01

    We present results for the azimuthal anisotropy of charged hadron distributions in A+A, p+A, d+A, and He3+A collisions within the IP-Glasma+MUSIC model. Obtained anisotropies are due to the fluid dynamic response of the system to the fluctuating initial geometry of the interaction region. While the elliptic and triangular anisotropies in peripheral Pb+Pb collisions at root-s=2.76 TeV are well described by the model, the same quantities in root-s=5.02 TeV p+Pb collisions underestimate the experimental data. This disagreement can be due to neglected initial state correlations or the lack of a detailed description of the fluctuating spatial structure of the proton, or both. We further present predictions for azimuthal anisotropies in p+Au, d+Au, and He3+Au collisions at root-s=200 GeV. For d+Au and 3He+Au collisions we expect the detailed substructure of the nucleon to become less important.

  19. Collective effects in light-heavy ion collisions

    Science.gov (United States)

    Schenke, Björn; Venugopalan, Raju

    2014-11-01

    We present results for the azimuthal anisotropy of charged hadron distributions in A+A, p+A, d+A, and 3He+A collisions within the IP-Glasma+MUSIC model. Obtained anisotropies are due to the fluid dynamic response of the system to the fluctuating initial geometry of the interaction region. While the elliptic and triangular anisotropies in peripheral Pb+Pb collisions at √{ s} = 2.76 TeV are well described by the model, the same quantities in √{ s} = 5.02 TeV p+Pb collisions underestimate the experimental data. This disagreement can be due to neglected initial state correlations or the lack of a detailed description of the fluctuating spatial structure of the proton, or both. We further present predictions for azimuthal anisotropies in p+Au, d+Au, and 3He+Au collisions at √{ s} = 200 GeV. For d+Au and 3He+Au collisions we expect the detailed substructure of the nucleon to become less important.

  20. Initial state fluctuations in collisions between light and heavy ions

    CERN Document Server

    Welsh, Kevin; Heinz, Ulrich W

    2016-01-01

    In high energy collisions involving small nuclei (p+p or x+Au collisions where x=p, d, or $^3$He) the fluctuating size, shape and internal gluonic structure of the nucleon is shown to have a strong effect on the initial size and shape of the fireball of new matter created in the collision. A systematic study of the eccentricity coefficients describing this initial fireball state for several semi-realistic models of nucleon substructure and for several practically relevant collision systems involving small nuclei is presented. The key importance of multiplicity fluctuations in such systems is pointed out. Our results show large differences from expectations based on conventional Glauber model simulations of the initial state created in such collisions.

  1. Luminescent ion pairs with tunable emission colors for light-emitting devices and electrochromic switches.

    Science.gov (United States)

    Guo, Song; Huang, Tianci; Liu, Shujuan; Zhang, Kenneth Yin; Yang, Huiran; Han, Jianmei; Zhao, Qiang; Huang, Wei

    2017-01-01

    Most recently, stimuli-responsive luminescent materials have attracted increasing interest because they can exhibit tunable emissive properties which are sensitive to external physical stimuli, such as light, temperature, force, and electric field. Among these stimuli, electric field is an important external stimulus. However, examples of electrochromic luminescent materials that exhibit emission color change induced by an electric field are limited. Herein, we have proposed a new strategy to develop electrochromic luminescent materials based on luminescent ion pairs. Six tunable emissive ion pairs (IP1-IP6) based on iridium(iii) complexes have been designed and synthesized. The emission spectra of ion pairs (IPs) show concentration dependence and the energy transfer process is very efficient between positive and negative ions. Interestingly, IP6 displayed white emission at a certain concentration in solution or solid state. Thus, in this contribution, UV-chip (365 nm) excited light-emitting diodes showing orange, light yellow and white emission colors were successfully fabricated. Furthermore, IPs displayed tunable and reversible electrochromic luminescence. For example, upon applying a voltage of 3 V onto the electrodes, the emission color of the solution of IP1 near the anode or cathode changed from yellow to red or green, respectively. Color tunable electrochromic luminescence has also been realized by using other IPs. Finally, a solid-film electrochromic switch device with a sandwiched structure using IP1 has been fabricated successfully, which exhibited fast and reversible emission color change.

  2. Track structure based modelling of light ion radiation effects on nuclear and mitochondrial DNA

    Science.gov (United States)

    Schmitt, Elke; Ottolenghi, Andrea; Dingfelder, Michael; Friedland, Werner; Kundrat, Pavel; Baiocco, Giorgio

    2016-07-01

    and SRIM calculations. Preliminary studies regarding the biological endpoints DSB (cluster) and chromosomal aberrations have been performed for selected light ions up to neon. Validation with experimental data as well as further calculations are underway and final results will be presented at the meeting. Mitochondrial alterations have been implicated in radiation-induced cardiovascular effects. To extend the applicability of PARTRAC biophysical tool towards effects on mitochondria, the nuclear DNA and chromatin as the primary target of radiation has been complemented by a model of mitochondrial DNA (mtDNA) to mimic a coronary cell with thousand mitochondria contained in the cytoplasm. Induced mtDNA damage (SSB, DSB) has been scored for 60Co photons and 5 MeV alpha-particle irradiation, assuming alternative radical scavenging capacities within the mitochondria. While direct radiation effects in mtDNA are identical to nuclear DNA, indirect effects in mtDNA are in general larger due to lower scavenging and the lack of DNA-protecting histones. These simulations complement the scarce experimental data on radiation-induced mtDNA damage and help elucidate the relative roles of initial mtDNA versus nuclear DNA damage and of pathways that amplify their respective effects. Ongoing and planned developments of PARTRAC include coupling with a radiation transport code and track-structure based calculations of cell killing for RBE studies on macroscopic scales within a mixed ion field. [1] Friedland, Dingfelder et al. (2011): "Track structures, DNA targets and radiation effects in the biophysical Monte Carlo simulation code PARTRAC", Mutat. Res. 711, 28-40 [2] Friedland et al. (2013): "Track structure based modelling of chromosome aberrations after photon and alpha-particle irradiation", Mutat. Res. 756, 213-223 [3] Schmid, Friedland et al. (2015): "Sub-micrometer 20 MeV protons or 45 MeV lithium spot irradiation enhances yields of dicentric chromosomes due to clustering of DNA

  3. Pulsed ion hall accelerator for investigation of reactions between light nuclei in the astrophysical energy range

    Science.gov (United States)

    Bystritsky, V. M.; Bystritsky, Vit. M.; Dudkin, G. N.; Nechaev, B. A.; Padalko, V. N.

    2017-07-01

    The factors defining the constraints on the current characteristics of the magnetically insulated ion diode (IDM) are considered. The specific current parameters close to the maximum possible ones are obtained for the particular IDM-40 design assigned for acceleration of light ions and investigation of nuclear reactions with small cross sections in the astrophysical energy range (2-40 keV) in the entrance channel. It is experimentally demonstrated that the chosen optimal operation conditions for IDM-40 units provide high stability of the parameters (energy distribution and composition of accelerated particle beams, degree of neutralization) of the accelerated particle flux, which increases during the working pulse.

  4. PHEV/EV Li-Ion Battery Second-Use Project (Presentation)

    Energy Technology Data Exchange (ETDEWEB)

    Neubauer, J.; Pesaran, A.

    2010-04-01

    Accelerated development and market penetration of plug-in hybrid electric vehicles (PHEVs) and electric vehicles (Evs) are restricted at present by the high cost of lithium-ion (Li-ion) batteries. One way to address this problem is to recover a fraction of the battery cost via reuse in other applications after the battery is retired from service in the vehicle, if the battery can still meet the performance requirements of other energy storage applications. In several current and emerging applications, the secondary use of PHEV and EV batteries may be beneficial; these applications range from utility peak load reduction to home energy storage appliances. However, neither the full scope of possible opportunities nor the feasibility or profitability of secondary use battery opportunities have been quantified. Therefore, with support from the Energy Storage activity of the U.S. Department of Energy's Vehicle Technologies Program, the National Renewable Energy Laboratory (NREL) is addressing this issue. NREL will bring to bear its expertise and capabilities in energy storage for transportation and in distributed grids, advanced vehicles, utilities, solar energy, wind energy, and grid interfaces as well as its understanding of stakeholder dynamics. This presentation introduces NREL's PHEV/EV Li-ion Battery Secondary-Use project.

  5. Argon-krypton ion laser as light source for medical photocoagulation applications

    Science.gov (United States)

    Kamiński, Wojciech; Warda, Piotr; Kasprzak, Jan; Kesik, Jerzy

    2013-01-01

    Photocoagulators are one of the most popular laser devices in medicine. Due to different kind of interaction of particular wavelength range of laser light with live tissues, sources of laser radiation which can cover as much as possible of visible spectrum are still very wanted (see [1,2]). In last years it also can be observed the intensive developing works on new photocoagulation technique called "micropulse coagulation" [3,4]. The most critical feature of lasers for micropulse coagulation is the possibility of fast switching between two selected laser power values. It seems that the good proposal for these applications can be ion laser filled with argon-krypton mixture. Authors previously have indicated the possibility of improvement of generation conditions in this type of laser in presence of buffer gases [5,6] and with use developed by authors pulse supply regime [7,8]. These improvements allow to obtain output power values of most important argon and krypton laser lines in laser filled with mixture of both gases, similar to values available in laser filled with pure gases. Presented in this paper the following researches are concerned on verification of possibilities of use of the developed laser system in photocoagulation with possibility of use of the laser system in micropulse coagulation technique.

  6. Clinical and radiobiological advantages of single-dose stereotactic light-ion radiation therapy for large intracranial arteriovenous malformations. Technical note.

    Science.gov (United States)

    Andisheh, Bahram; Brahme, Anders; Bitaraf, Mohammad A; Mavroidis, Panayiotis; Lind, Bengt K

    2009-11-01

    Radiation treatment of large arteriovenous malformations (AVMs) remains difficult and not very effective, even though seemingly promising methods such as staged volume treatments have been proposed by some radiation treatment centers. In symptomatic patients harboring large intracranial AVMs not amenable to embolization or resection, single-session high-dose stereotactic radiation therapy is a viable option, and the special characteristics of high-ionization-density light-ion beams offer several treatment advantages over photon and proton beams. These advantages include a more favorable depth-dose distribution in tissue, an almost negligible lateral scatter of the beam, a sharper penumbra, a steep dose falloff beyond the Bragg peak, and a higher probability of vascular response due to high ionization density and associated induction of endothelial cell proliferation and/or apoptosis. Carbon ions were recently shown to be an effective treatment for skull-base tumors. Bearing that in mind, the authors postulate that the unique physical and biological characteristics of light-ion beams should convey considerable clinical advantages in the treatment of large AVMs. In the present meta-analysis the authors present a comparison between light-ion beam therapy and more conventional modalities of radiation treatment with respect to these lesions. Dose-volume histograms and data on peripheral radiation doses for treatment of large AVMs were collected from various radiation treatment centers. Dose-response parameters were then derived by applying a maximum likelihood fitting of a binomial model to these data. The present binomial model was needed because the effective number of crucial blood vessels in AVMs (the number of vessels that must be obliterated to effect a cure, such as large fistulous nidus vessels) is low, making the Poisson model less suitable. In this study the authors also focused on radiobiological differences between various radiation treatments. Light-ion

  7. Light-Assisted Cold Chemical Reactions of Barium Ions with Rubidium Atoms

    CERN Document Server

    Hall, Felix H J; Raoult, Maurice; Dulieu, Olivier; Willitsch, Stefan

    2013-01-01

    Light-assisted reactive collisions between laser-cooled Ba+ ions and Rb atoms were studied in an ion-atom hybrid trap. The reaction rate was found to strongly depend on the electronic state of the reaction partners with the largest rate constant (7(2) x 10^-11 cm^3 s^-1) obtained for the excited Ba+(6s)+Rb(5p) reaction channel. Similar to the previously studied Ca+ + Rb system, charge transfer and radiative association were found to be the dominant reactive processes. The generation of molecular ions by radiative association could directly be observed by their sympathetic cooling into a Coulomb crystal. Potential energy curves up to the Ba+(6s)+Rb(5p) asymptote and reactive-scattering cross sections for the radiative processes were calculated. The theoretical rate constant obtained for the lowest reaction channel Ba+(6s)+Rb(5s) is compatible with the experimental estimates obtained thus far.

  8. Vacuum and magnetic field constraints in a H -/light ion synchrotron

    Science.gov (United States)

    Arduini, G.; Martin, R. L.; Rossi, S.; Silari, M.

    1994-08-01

    Acceleration of H - ions in a synchrotron imposes severe restrictions on the level of residual pressure in the vacuum chamber and the maximum magnetic field in the magnets of the ring. Significant vacuum requirements are also imposed by the acceleration of ions. This paper discusses these two aspects of the design of a combined H -/light ion synchrotron for radiation therapy. The fractional loss of the accelerated beam induced by the two processes is evaluated on the basis of a general treatment of the physics of these phenomena. The values of the vacuum and magnetic field necessary for normal operation of the machine are specified and a discussion is given of the behaviour of the above quantities as a function of several parameters such as beam energy, composition and pressure of the residual gas in the vacuum chamber and beam extraction time.

  9. Elastic forward analysis using sup 7 Li ions A useful tool for H and light elements determination

    CERN Document Server

    Romero, S; Murillo, G; Berdejo, H M

    2002-01-01

    Films of CN sub x /Si, TiN sub x /AISI 304 and AlO sub x /Si were analyzed with sup 7 Li ions from 4.0 to 4.5 MeV and an experimental arrangement that, through detection of scattered projectiles and recoils by a single detector, allows quantification of H, light elements and heavier ones. A discussion is presented of the capabilities of Rutherford backscattering spectrometry (RBS) and conventional elastic recoil detection analysis (ERDA) compared to elastic forward analysis.

  10. [The French project ETOILE: review of clinical data for light ion hadrontherapy].

    Science.gov (United States)

    Pommier, P; Balosso, J; Bolla, M; Gérard, J P

    2002-12-01

    The Lawrence Berkeley Laboratory was the pioneer in light ions hadrontherapy with almost 2500 patients treated between 1957 and 1993 with Helium and Neon. The NIRS (National Institute For Radiological Science, Chiba, Japan) was the first dedicated medical centre for cancer with more than 1200 patients exclusively treated with carbon ion from 1994. A three-year 70 to 100% local control was reported for radio-resistant cancers, supporting the use of high LET particles. Hypo-fractionation was particularly explored for lung cancers and hepatocarcinoma (4 sessions only). Dose escalation studies demonstrated a tumour dose-effect and permitted to precise dose constraints for healthy tissues especially for the rectum. More than 140 patients were treated with carbon ion exclusively or associated with photons since 1997 in the GSI laboratory Gesellschaft Für Schwerionenforschung, Darmstadt, Germany). A very high local control was also obtained for radioresistant cancer of the base of the skull. Preliminary clinical data seem to confirm the expected therapeutic gain with light ions, due to their ballistic and radio-biological properties, and justify the European projects for the construction of dedicated medical facilities for cancers. The French "Etoile" project will be integrated in the European hadrontherapy network "Enlight", with the objectives to coordinate technologic, medical and economic features.

  11. Systemic immunoglobulin light-chain amyloidosis presenting hematochezia as the initial symptom.

    Science.gov (United States)

    Kon, Tetsuo; Nakagawa, Naoki; Yoshikawa, Fumitsugu; Haba, Kazunao; Kitagawa, Nagako; Izumi, Michihiro; Kumazaki, Setsuo; Ishida, Satoshi; Aikawa, Ryuichi

    2016-08-01

    Immunoglobulin light-chain (AL) amyloidosis is characterized by the deposition of insoluble fibrils composed of immunoglobulin light chains secreted by monoclonal plasma cells. Given the recent advances in the therapy of AL amyloidosis, it is important to diagnose this disease as early as possible. Herein, we describe the case of a 62-year-old man with hepatitis C virus (HCV)-related cirrhosis presenting with hematochezia. Colonoscopy showed multiple submucosal hematomas within the region ranging from the transverse colon to the sigmoid colon. Kappa immunoglobulin light-chain amyloid deposition was also detected. Bone marrow examination revealed a monoclonal abnormal plasma cell population. Thus, the patient was diagnosed with systemic immunoglobulin light-chain amyloidosis. The hematochezia was conservatively managed. However, because of liver failure caused by liver cirrhosis, the patient developed massive pleural effusion and died of respiratory failure. Postmortem examination revealed amyloid deposition in the esophagus, stomach, duodenum, ileum, descending colon, pancreas, heart, and lung. In these organs, amyloid deposition was limited to the vascular wall. We concluded that AL amyloidosis can present hematochezia arising from submucosal hematoma in the large colon before other systemic symptoms appear.

  12. Visible-light excitation of iminium ions enables the enantioselective catalytic β-alkylation of enals

    Science.gov (United States)

    Silvi, Mattia; Verrier, Charlie; Rey, Yannick P.; Buzzetti, Luca; Melchiorre, Paolo

    2017-09-01

    Chiral iminium ions—generated upon condensation of α,β-unsaturated aldehydes and amine catalysts—are used extensively by chemists to make chiral molecules in enantioenriched form. In contrast, their potential to absorb light and promote stereocontrolled photochemical processes remains unexplored. This is despite the fact that visible-light absorption by iminium ions is a naturally occurring event that triggers the mechanism of vision in higher organisms. Herein we demonstrate that the direct excitation of chiral iminium ions can unlock unconventional reaction pathways, enabling enantioselective catalytic photochemical β-alkylations of enals that cannot be realized via thermal activation. The chemistry uses readily available alkyl silanes, which are recalcitrant to classical conjugate additions, and occurs under illumination by visible-light-emitting diodes. Crucial to success was the design of a chiral amine catalyst with well-tailored electronic properties that can generate a photo-active iminium ion while providing the source of stereochemical induction. This strategy is expected to offer new opportunities for reaction design in the field of enantioselective catalytic photochemistry.

  13. Simulation study on light ions identification methods for carbon beams from 95 to 400 MeV/A

    CERN Document Server

    Salvador, S; Fontbonne, J M; Dudouet, J; Colin, J; Cussol, D

    2013-01-01

    Monte Carlo simulations have been performed in order to evaluate the efficiencies of several light ions identification techniques. The detection system was composed with layers of scintillating material to measure either the deposited energy or the time-of-flight of ions produced by nuclear reactions between 12C projectiles and a PMMA target. Well known techniques such as (DELTA) E--Range, (DELTA) E--E--ToF and (DELTA)E--E are presented and their particle identification efficiencies are compared one to another regarding the generated charge and mass of the particle to be identified. The simulations allowed to change the beam energy matching the ones proposed in an hadron therapy facility, namely from 95 to 400 MeV/A.

  14. Precise atomic-scale investigations of material sputtering process by light gas ions in pre-threshold energy region

    CERN Document Server

    Suvorov, A L

    2002-01-01

    Foundation and prospects of the new original technique of the sputtering yield determination of electro-conducting materials and sub-atomic layers on their surface by light gas ions the pre-threshold energy region (from 10 to 500 eV) are considered. The technique allows to identify individual surface vacancies, i.e., to count individual sputtered atoms directly. A short review of the original results obtained by using the developed techniques is given. Data are presented and analyzed concerning energy thresholds of the sputtering onset and energy dependences of sputtering yield in the threshold energy region for beryllium, tungsten, tungsten oxide, alternating tungsten-carbon layers, three carbon materials as well as for sub-atomic carbon layers on surface of certain metals at their bombardment by hydrogen, deuterium and/or helium ions

  15. Interfacing ion-exchanged waveguide for the efficient excitation of surface plasmons (Presentation Recording)

    Science.gov (United States)

    Beltran Madrigal, Josslyn; Berthel, Martin; Gardillou, Florent; Tellez Limon, Ricardo; Couteau, Christophe; Barbier, Denis; Drezet, Aurelien; Salas-Montiel, Rafael; Huant, Serge; Blaize, Sylvain

    2015-09-01

    Several works have already shown that the excitation of plasmonic structures through waveguides enables a strong light confinement and low propagation losses [1]. This kind of excitation is currently exploited in areas such as biosensing [2], nanocircuits[3] and spectroscopy[4]. Efficient excitation of surface plasmon modes (SPP) with guided modes supported by high-index-contrast waveguides, such as silicon-on-insulator waveguides, had already been shown [1,5], however, the use of weak-confined guided modes of an ion exchanged waveguide on glass as a source of excitation of SPP represents a scientific and technological breakthrough. This is because the integration of plasmonic structures into low-index-contrast waveguide increases the bandwidth of operation and compatibility with conventional optical fibers. In this work, we describe how an adiabatic tapered coupler formed by an intermediate high-index-contrast layer placed between a plasmonic structure and an ion-exchanged waveguide decreases the mismatch between effective indices, size, and shape of the guided modes. This hybrid structure concentrates the electromagnetic energy from the micrometer to the nanometer scale with low coupling losses to radiative modes. The electromagnetic mode confined to the high-index-contrast waveguide then works as an efficient source of SPP supported by metallic nanostructures placed on its surface. We theoretically studied the modal properties and field distribution along the adiabatic coupler structure. In addition, we fabricated a high-index-contrast waveguide by electron beam lithography and thermal evaporation on top of an ion-exchanged waveguide on glass. This structure was characterized with the use of near field scanning optical microscopy (NSOM). Numerical simulations were compared with the experimental results. [1] N. Djaker, R. Hostein, E. Devaux, T. W. Ebbesen, and H. Rigneault, and J. Wenger, J. Phys. Chem. C 114, 16250 (2010). [2] P. Debackere, S. Scheerlinck, P

  16. Ion-exchangeable titanate nanotubes with visible light responsive photocatalytic activities for dyes degradation.

    Science.gov (United States)

    Li, Xiukai; Zhong, Yushu

    2014-09-01

    Sn(2+)- and Pb(2+)-substituted NaHTi3O7 nanotubes were prepared by a hydrothermal synthesis method followed by ion-exchange reaction. The samples were characterized by XRD, SEM, TEM, XPS and UV-visible diffuse reflectance spectroscopy. The photocatalytic activities were investigated for the photodegradation of methylene orange (MO) and methylene blue (MB) under visible light irradiation. The results indicate that Sn2+ and Pb2+ substitutions could have significant impacts on the optical properties and photocatalytic activities of samples. Both Sn(2+)- and Pb(2+)-substituted NaHTi3O7 nanotubes show activities for methylene orange and methylene blue photodegradation under visible light irradiation. With better absorption of visible light, the Sn-NaHTi3O7 sample showed higher activity than Pb-NaHTi3O7.

  17. Ion-induced ionization and capture cross sections for DNA nucleobases impacted by light ions

    Science.gov (United States)

    Champion, Christophe; Galassi, Mariel E.; Weck, Philippe F.; Fojón, Omar; Hanssen, Jocelyn; Rivarola, Roberto D.

    2012-11-01

    Two quantum mechanical models (CB1 and CDW-EIS) are here presented for describing electron ionization and electron capture induced by heavy charged particles in DNA bases. Multiple differential and total cross sections are determined and compared with the scarce existing experimental data.

  18. Atomic spectroscopy on fusion relevant ions and studies of light impurities in the JET tokamak

    Energy Technology Data Exchange (ETDEWEB)

    Tunklev, M

    1999-03-01

    The spectrum and energy levels of C IV and the 3l-4l system of the Mg-like ions in the iron group elements have been investigated. This has led to several hundred identified transitions, many of them previously unknown. Using the Charge Exchange Diagnostic system at JET, ion temperatures, rotation velocities and densities have been derived from visible spectroscopic measurements on fully ionised light impurities, such as He, C, N and Ne. The existence of plume contribution from beam produced hydrogen-like ions has been proven beyond any doubt to affect the deduction of the active charge exchange signal of He II. In the case of C VI the plume signal was estimated to be at least a factor of five lower than the active charge exchange signal. Line integrated passive charge exchange emission between neutral background atoms and fully stripped impurity ions has been investigated and modelled. When the synthetic spectrum is fitted into the experimentally detected spectra the neutral background density can be deduced. The importance of including background atoms (H, D and T) as charge exchange donors, not only in state 2s, but also in state 1s, has shown to be crucial in high temperature shots. Transport of light impurities has been studied with gas puff injections into steady state H-mode plasmas. The results suggest that light impurities are transported as described by the neo-classical Pfirsch-Schlueter regime at the edge, whilst in the centre, sawtoothing, preferably to Banana transport, is mixing the plasma and increases the measured values on the diffusion. For the peaking of impurities in a steady state plasma an anomalous treatment was more in agreement with the experimental data. Certain confinement information, previously predicted theoretically as a part of the peaking equation, has been experimentally verified

  19. Hybrid metal-dielectric nanostructures for advanced light-field manipulation (Conference Presentation)

    Science.gov (United States)

    Staude, Isabelle; Guo, Rui; Rusak, Evgenia; Dominguez, Jason; Decker, Manuel; Rockstuhl, Carsten; Brener, Igal; Neshev, Dragomir N.; Pertsch, Thomas; Kivshar, Yuri S.

    2017-02-01

    All-dielectric and plasmonic nanostructures have complementary advantages regarding their capabilities for controlling light fields at the nanoscale [1]. While all-dielectric nanostructures can provide near-unity efficiency, plasmonic nanostructures are more compact and offer strong near-field enhancement. Combination of photonic nanostructures of both types offers a promising route towards compact optical elements that unify low absorption losses with small footprints, while at the same time providing a high versatility in engineering the optical response of the hybrid system towards specific functionalities. This talk aims to review our recent progress in coupling designed plasmonic nanoantennas to high-index dielectric nanostructures. Following a general analysis of coupling of plasmonic and high-refractive-index dielectric nanoresonators, various specific hybrid nanostructure designs will be discussed. For the fabrication of designed hybrid metal-dielectric nanostructures we use a two-step electron-beam lithography (EBL) procedure [2]. The first step of EBL is used in combination with reactive-ion etching to define the dielectric nanostructures. The second step of EBL is followed by evaporation of gold and a lift-off process, and serves to define the plasmonic elements. Between the two steps, a precision alignment procedure is performed in order to allow for the precise positioning of the gold nanostructures with respect to the silicon nanostructures. Using this approach, we realize and optically characterize various hybrid metal-dielectric nanostructures designed to support a range of novel functionalities, including directional emission enhancement [2] and on-chip light routing. [1] E. Rusak et al., Appl. Phys. Lett. 105, 221109 (2014). [2] R. Guo et al., ACS Photonics 3, 349-353 (2016).

  20. Nanowires: Quantitative Probing of Cu(2+) Ions Naturally Present in Single Living Cells (Adv. Mater. 21/2016).

    Science.gov (United States)

    Lee, Junho; Lee, Hwa-Rim; Pyo, Jaeyeon; Jung, Youngseob; Seo, Ji-Young; Ryu, Hye Guk; Kim, Kyong-Tai; Je, Jung Ho

    2016-06-01

    Quantitative probing of the Cu(2+) ions naturally present in single living cells is accomplished by a probe made from a quantum-dot-embedded-nanowire waveguide. After inserting the active nanowire-based waveguide probe into single living cells, J. H. Je and co-workers directly observe photoluminescence (PL) quenching of the embedded quantum dots by the Cu(2+) ions diffused into the probe as described on page 4071. This results in quantitative measurement of intracellular Cu(2+) ions.

  1. Imaging and modeling of collagen architecture in living tissue with polarized light transfer (Conference Presentation)

    Science.gov (United States)

    Ramella-Roman, Jessica C.; Stoff, Susan; Chue-Sang, Joseph; Bai, Yuqiang

    2016-03-01

    The extra-cellular space in connective tissue of animals and humans alike is comprised in large part of collagen. Monitoring of collagen arrangement and cross-linking has been utilized to diagnose a variety of medical conditions and guide surgical intervention. For example, collagen monitoring is useful in the assessment and treatment of cervical cancer, skin cancer, myocardial infarction, and non-arteritic anterior ischemic optic neuropathy. We have developed a suite of tools and models based on polarized light transfer for the assessment of collagen presence, cross-linking, and orientation in living tissue. Here we will present some example of such approach applied to the human cervix. We will illustrate a novel Mueller Matrix (MM) imaging system for the study of cervical tissue; furthermore we will show how our model of polarized light transfer through cervical tissue compares to the experimental findings. Finally we will show validation of the methodology through histological results and Second Harmonic imaging microscopy.

  2. Degradation of Methylammonium Lead Iodide Perovskite Structures through Light and Electron Beam Driven Ion Migration.

    Science.gov (United States)

    Yuan, Haifeng; Debroye, Elke; Janssen, Kris; Naiki, Hiroyuki; Steuwe, Christian; Lu, Gang; Moris, Michèle; Orgiu, Emanuele; Uji-I, Hiroshi; De Schryver, Frans; Samorì, Paolo; Hofkens, Johan; Roeffaers, Maarten

    2016-02-04

    Organometal halide perovskites show promising features for cost-effective application in photovoltaics. The material instability remains a major obstacle to broad application because of the poorly understood degradation pathways. Here, we apply simultaneous luminescence and electron microscopy on perovskites for the first time, allowing us to monitor in situ morphology evolution and optical properties upon perovskite degradation. Interestingly, morphology, photoluminescence (PL), and cathodoluminescence of perovskite samples evolve differently upon degradation driven by electron beam (e-beam) or by light. A transversal electric current generated by a scanning electron beam leads to dramatic changes in PL and tunes the energy band gaps continuously alongside film thinning. In contrast, light-induced degradation results in material decomposition to scattered particles and shows little PL spectral shifts. The differences in degradation can be ascribed to different electric currents that drive ion migration. Moreover, solution-processed perovskite cuboids show heterogeneity in stability which is likely related to crystallinity and morphology. Our results reveal the essential role of ion migration in perovskite degradation and provide potential avenues to rationally enhance the stability of perovskite materials by reducing ion migration while improving morphology and crystallinity. It is worth noting that even moderate e-beam currents (86 pA) and acceleration voltages (10 kV) readily induce significant perovskite degradation and alter their optical properties. Therefore, attention has to be paid while characterizing such materials using scanning electron microscopy or transmission electron microscopy techniques.

  3. Evidence for light-by-light scattering in heavy-ion collisions with the ATLAS detector at the LHC

    CERN Document Server

    Aaboud, Morad; Abbott, Brad; Abdallah, Jalal; Abdinov, Ovsat; Abeloos, Baptiste; Abidi, Syed Haider; AbouZeid, Ossama; Abraham, Nicola; Abramowicz, Halina; Abreu, Henso; Abreu, Ricardo; Abulaiti, Yiming; Acharya, Bobby Samir; Adachi, Shunsuke; Adamczyk, Leszek; Adelman, Jahred; Adersberger, Michael; Adye, Tim; Affolder, Tony; Agatonovic-Jovin, Tatjana; Agheorghiesei, Catalin; Aguilar-Saavedra, Juan Antonio; Ahlen, Steven; Ahmadov, Faig; Aielli, Giulio; Akatsuka, Shunichi; Akerstedt, Henrik; Åkesson, Torsten Paul Ake; Akimov, Andrei; Alberghi, Gian Luigi; Albert, Justin; Alconada Verzini, Maria Josefina; Aleksa, Martin; Aleksandrov, Igor; Alexa, Calin; Alexander, Gideon; Alexopoulos, Theodoros; Alhroob, Muhammad; Ali, Babar; Aliev, Malik; Alimonti, Gianluca; Alison, John; Alkire, Steven Patrick; Allbrooke, Benedict; Allen, Benjamin William; Allport, Phillip; Aloisio, Alberto; Alonso, Alejandro; Alonso, Francisco; Alpigiani, Cristiano; Alshehri, Azzah Aziz; Alstaty, Mahmoud; Alvarez Gonzalez, Barbara; Άlvarez Piqueras, Damián; Alviggi, Mariagrazia; Amadio, Brian Thomas; Amaral Coutinho, Yara; Amelung, Christoph; Amidei, Dante; Amor Dos Santos, Susana Patricia; Amorim, Antonio; Amoroso, Simone; Amundsen, Glenn; Anastopoulos, Christos; Ancu, Lucian Stefan; Andari, Nansi; Andeen, Timothy; Anders, Christoph Falk; Anders, John Kenneth; Anderson, Kelby; Andreazza, Attilio; Andrei, George Victor; Angelidakis, Stylianos; Angelozzi, Ivan; Angerami, Aaron; Anghinolfi, Francis; Anisenkov, Alexey; Anjos, Nuno; Annovi, Alberto; Antel, Claire; Antonelli, Mario; Antonov, Alexey; Antrim, Daniel Joseph; Anulli, Fabio; Aoki, Masato; Aperio Bella, Ludovica; Arabidze, Giorgi; Arai, Yasuo; Araque, Juan Pedro; Araujo Ferraz, Victor; Arce, Ayana; Ardell, Rose Elisabeth; Arduh, Francisco Anuar; Arguin, Jean-Francois; Argyropoulos, Spyridon; Arik, Metin; Armbruster, Aaron James; Armitage, Lewis James; Arnaez, Olivier; Arnold, Hannah; Arratia, Miguel; Arslan, Ozan; Artamonov, Andrei; Artoni, Giacomo; Artz, Sebastian; Asai, Shoji; Asbah, Nedaa; Ashkenazi, Adi; Asquith, Lily; Assamagan, Ketevi; Astalos, Robert; Atkinson, Markus; Atlay, Naim Bora; Augsten, Kamil; Avolio, Giuseppe; Axen, Bradley; Ayoub, Mohamad Kassem; Azuelos, Georges; Baas, Alessandra; Baca, Matthew John; Bachacou, Henri; Bachas, Konstantinos; Backes, Moritz; Backhaus, Malte; Bagiacchi, Paolo; Bagnaia, Paolo; Baines, John; Bajic, Milena; Baker, Oliver Keith; Baldin, Evgenii; Balek, Petr; Balestri, Thomas; Balli, Fabrice; Balunas, William Keaton; Banas, Elzbieta; Banerjee, Swagato; Bannoura, Arwa A E; Barak, Liron; Barberio, Elisabetta Luigia; Barberis, Dario; Barbero, Marlon; Barillari, Teresa; Barisits, Martin-Stefan; Barklow, Timothy; Barlow, Nick; Barnes, Sarah Louise; Barnett, Bruce; Barnett, Michael; Barnovska-Blenessy, Zuzana; Baroncelli, Antonio; Barone, Gaetano; Barr, Alan; Barranco Navarro, Laura; Barreiro, Fernando; Barreiro Guimarães da Costa, João; Bartoldus, Rainer; Barton, Adam Edward; Bartos, Pavol; Basalaev, Artem; Bassalat, Ahmed; Bates, Richard; Batista, Santiago Juan; Batley, Richard; Battaglia, Marco; Bauce, Matteo; Bauer, Florian; Bawa, Harinder Singh; Beacham, James; Beattie, Michael David; Beau, Tristan; Beauchemin, Pierre-Hugues; Bechtle, Philip; Beck, Hans~Peter; Becker, Kathrin; Becker, Maurice; Beckingham, Matthew; Becot, Cyril; Beddall, Andrew; Beddall, Ayda; Bednyakov, Vadim; Bedognetti, Matteo; Bee, Christopher; Beermann, Thomas; Begalli, Marcia; Begel, Michael; Behr, Janna Katharina; Bell, Andrew Stuart; Bella, Gideon; Bellagamba, Lorenzo; Bellerive, Alain; Bellomo, Massimiliano; Belotskiy, Konstantin; Beltramello, Olga; Belyaev, Nikita; Benary, Odette; Benchekroun, Driss; Bender, Michael; Bendtz, Katarina; Benekos, Nektarios; Benhammou, Yan; Benhar Noccioli, Eleonora; Benitez, Jose; Benjamin, Douglas; Benoit, Mathieu; Bensinger, James; Bentvelsen, Stan; Beresford, Lydia; Beretta, Matteo; Berge, David; Bergeaas Kuutmann, Elin; Berger, Nicolas; Beringer, Jürg; Berlendis, Simon; Bernard, Nathan Rogers; Bernardi, Gregorio; Bernius, Catrin; Bernlochner, Florian Urs; Berry, Tracey; Berta, Peter; Bertella, Claudia; Bertoli, Gabriele; Bertolucci, Federico; Bertram, Iain Alexander; Bertsche, Carolyn; Bertsche, David; Besjes, Geert-Jan; Bessidskaia Bylund, Olga; Bessner, Martin Florian; Besson, Nathalie; Betancourt, Christopher; Bethani, Agni; Bethke, Siegfried; Bevan, Adrian John; Bianchi, Riccardo-Maria; Bianco, Michele; Biebel, Otmar; Biedermann, Dustin; Bielski, Rafal; Biesuz, Nicolo Vladi; Biglietti, Michela

    2017-08-14

    Light-by-light scattering ($\\gamma\\gamma\\rightarrow\\gamma\\gamma$) is a quantum-mechanical process that is forbidden in the classical theory of electrodynamics. This reaction is accessible at the Large Hadron Collider thanks to the large electromagnetic field strengths generated by ultra-relativistic colliding lead (Pb) ions. Using 480 $\\mu$b$^{-1}$ of Pb+Pb collision data recorded at a centre-of-mass energy per nucleon pair of 5.02 TeV by the ATLAS detector, the ATLAS Collaboration reports evidence for the $\\gamma\\gamma\\rightarrow\\gamma\\gamma$ reaction. A total of 13 candidate events are observed with an expected background of $2.6\\pm0.7$ events. After background subtraction and analysis corrections, the fiducial cross section of the process $\\textrm{Pb+Pb}\\,(\\gamma\\gamma)\\rightarrow \\textrm{Pb}^{(\\ast)}\\textrm{+}\\textrm{Pb}^{(\\ast)}\\,\\gamma\\gamma$, for photon transverse energy $E_{\\mathrm{T}}>3$ GeV, photon absolute pseudorapidity $|\\eta|<2.4$, diphoton invariant mass greater than 6 GeV, diphoton transver...

  4. Evidence for light-by-light scattering in heavy-ion collisions with the ATLAS detector at the LHC

    CERN Document Server

    Sydorenko, Alexander; The ATLAS collaboration

    2017-01-01

    LHCC 2017 POSTER. Light-by-light scattering ($\\gamma\\gamma\\rightarrow\\gamma\\gamma$) is a quantum-mechanical process that is forbidden in the classical theory of electrodynamics. This reaction is accessible at the Large Hadron Collider thanks to the large electromagnetic field strengths generated by ultra-relativistic colliding lead (Pb) ions. Using 480$\\mu \\text{b}^{-1}$ of Pb+Pb collision data recorded at a centre-of-mass energy per nucleon pair of $5.02$ TeV by the ATLAS detector, the ATLAS Collaboration reports evidence for the $\\gamma\\gamma\\rightarrow\\gamma\\gamma$ reaction. A total of $13$ candidate events are observed with an expected background of $2.6\\pm0.7$ events. After background subtraction and analysis corrections, the fiducial cross section of the process $\\textrm{Pb+Pb}\\,(\\gamma\\gamma)\\rightarrow \\textrm{Pb}^{(\\ast)}\\textrm{+}\\textrm{Pb}^{(\\ast)}\\,\\gamma\\gamma$, for photon transverse energy $E_{\\text{T}}>3$ GeV, photon absolute pseudorapidity $|\\eta|<2.4$, diphoton invariant mass greater than...

  5. Minibeam Therapy With Protons and Light Ions: Physical Feasibility and Potential to Reduce Radiation Side Effects and to Facilitate Hypofractionation

    Energy Technology Data Exchange (ETDEWEB)

    Dilmanian, F. Avraham, E-mail: avraham.dilmanian@stonybrook.edu [Departments of Radiation Oncology, Neurology, and Radiology, Stony Brook University Medical Center, Stony Brook, New York (United States); Eley, John G. [Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Krishnan, Sunil [Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States)

    2015-06-01

    Purpose: Despite several advantages of proton therapy over megavoltage x-ray therapy, its lack of proximal tissue sparing is a concern. The method presented here adds proximal tissue sparing to protons and light ions by turning their uniform incident beams into arrays of parallel, small, or thin (0.3-mm) pencil or planar minibeams, which are known to spare tissues. As these minibeams penetrate the tissues, they gradually broaden and merge with each other to produce a solid beam. Methods and Materials: Broadening of 0.3-mm-diameter, 109-MeV proton pencil minibeams was measured using a stack of radiochromic films with plastic spacers. Monte Carlo simulations were used to evaluate the broadening in water of minibeams of protons and several light ions and the dose from neutron generated by collimator. Results: A central parameter was tissue depth, where the beam full width at half maximum (FWHM) reached 0.7 mm, beyond which tissue sparing decreases. This depth was 22 mm for 109-MeV protons in a film stack. It was also found by simulations in water to be 23.5 mm for 109 MeV proton pencil minibeams and 26 mm for 116 MeV proton planar minibeams. For light ions, all with 10 cm range in water, that depth increased with particle size; specifically it was 51 mm for Li-7 ions. The ∼2.7% photon equivalent neutron skin dose from the collimator was reduced 7-fold by introducing a gap between the collimator and the skin. Conclusions: Proton minibeams can be implemented at existing particle therapy centers. Because they spare the shallow tissues, they could augment the efficacy of proton therapy and light particle therapy, particularly in treating tumors that benefit from sparing of proximal tissues such as pediatric brain tumors. They should also allow hypofractionated treatment of all tumors by allowing the use of higher incident doses with less concern about proximal tissue damage.

  6. Stomatal Blue Light Response Is Present in Early Vascular Plants1[OPEN

    Science.gov (United States)

    Doi, Michio; Kitagawa, Yuki; Shimazaki, Ken-ichiro

    2015-01-01

    Light is a major environmental factor required for stomatal opening. Blue light (BL) induces stomatal opening in higher plants as a signal under the photosynthetic active radiation. The stomatal BL response is not present in the fern species of Polypodiopsida. The acquisition of a stomatal BL response might provide competitive advantages in both the uptake of CO2 and prevention of water loss with the ability to rapidly open and close stomata. We surveyed the stomatal opening in response to strong red light (RL) and weak BL under the RL with gas exchange technique in a diverse selection of plant species from euphyllophytes, including spermatophytes and monilophytes, to lycophytes. We showed the presence of RL-induced stomatal opening in most of these species and found that the BL responses operated in all euphyllophytes except Polypodiopsida. We also confirmed that the stomatal opening in lycophytes, the early vascular plants, is driven by plasma membrane proton-translocating adenosine triphosphatase and K+ accumulation in guard cells, which is the same mechanism operating in stomata of angiosperms. These results suggest that the early vascular plants respond to both RL and BL and actively regulate stomatal aperture. We also found three plant species that absolutely require BL for both stomatal opening and photosynthetic CO2 fixation, including a gymnosperm, C. revoluta, and the ferns Equisetum hyemale and Psilotum nudum. PMID:26307440

  7. Visible light emission in collisions between O5+ ions and He atoms

    Institute of Scientific and Technical Information of China (English)

    李大万; 潘广炎; 杨锋; 刘占稳; 周嗣信; 张文; 张雪珍; 郭晓虹; 王友德; 杨治虎; 马新文; 刘惠萍; 赵孟春

    1997-01-01

    Visible light emission spectra during collisions between O5 + ions and He atoms in the range of 200-800 nm at different projectile energies (4.06-5.31 keV·u 1) have been measured. Emission spectra show that there arc three channels of excitation in the O5+ -He collision system; (i) single-electron capture into excited states; (ii) double-electron capture into excited states; (iii) direct excitation of target atoms. There are transitions between states with comparably high quantum numbers nl The absolute emission cross-sections of every spectral line are calculated. The relations of these cross-sect ions with the energy of the projectiles are studied.

  8. Decontamination Characteristics of Stainless Steel Surface Contaminated with Cs{sup +} Ion by Light Ablation

    Energy Technology Data Exchange (ETDEWEB)

    Baigalmaa, Byambatseren; Won, Hui-Jun; Moon, Jei-Kwon; Jung, Chong-Hun [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Hyun, Jae-Hyuk [Chungnam National University, Daejeon (Korea, Republic of)

    2008-05-15

    The characteristics of decontamination method by light ablation are the remote operation, a short application time, and the high removal efficiency. Furthermore, the generation of the secondary waste is negligible. The radioactivity of hot cells in DFDF (Dupic Fuel Development Facility) is presumed to be very high and the predominant radionuclide is Cs-137. A series of laser decontamination studies by the fabricated Qswitched Nd-YAG laser system were performed on the stainless steel specimens artificially contaminated with Cs{sup +} ion. Decontamination characteristics of the stainless steel were analyzed by SEM and EPMA.

  9. Simple estimates of excitation energy sharing between heavy and light fragments in heavy-ion reactions

    Energy Technology Data Exchange (ETDEWEB)

    Dasso, C.H.; Lozano, M.; Pollarolo, G.

    1985-12-01

    Qualitative arguments are used to estiamte the ratio of excitation energies between heavy and light fragments for asymmetric heavy-ion collisions. The value of this quantity is linked to the relative role played by inelastic and transfer degrees of freedom and thereby to an approximate function of the total kinetic energy loss. A numerical analysis that confirms the trends anticipated by the simple arguments is performed for the reactions /sup 56/Fe+ /sup 238/U and /sup 86/Kr+ /sup 208/Pb at bombarding energies in the laboratory of 476 and 1565 MeV, respectively.

  10. Biodegradable Polycaprolactone as Ion Solvating Polymer for Solution-Processed Light-Emitting Electrochemical Cells

    Science.gov (United States)

    Jürgensen, Nils; Zimmermann, Johannes; Morfa, Anthony John; Hernandez-Sosa, Gerardo

    2016-11-01

    In this work, we demonstrate the use of the biodegradable polymer polycaprolactone (PCL) as the ion solvating polymer in solution-processed light-emitting electrochemical cells (LEC). We show that the inclusion of PCL in the active layer yields higher ionic conductivities and thus contributes to a rapid formation of the dynamic p-i-n junction and reduction of operating voltages. PCL shows no phase separation with the emitter polymer and reduces film roughness. The devices show light-emission at voltages as low as 3.2 V and lifetimes on the order of 30 h operating above 150 cd m‑2 with turn-on times <20 s and current and luminous efficacies of 3.2 Cd A‑1 and 1.5 lm W‑1 respectively.

  11. Extraction of alginate biopolymer present in marine alga sargassum filipendula and bioadsorption of metallic ions

    Directory of Open Access Journals (Sweden)

    Sirlei Jaiana Kleinübing

    2013-04-01

    Full Text Available This paper studies the bioadsorption of Pb2+, Cu2+, Cd2+ and Zn2+ ions by marine alga Sargassum filipendula and by the alginate biopolymer extracted from this alga. The objective is to evaluate the importance of this biopolymer in removing different metallic ions by the marine alga S. filipendula. In the equilibrium study, the same affinity order was observed for both bioadsorbents: Pb2+ > Cu2+ > Zn2+ > Cd2+. For Pb2+ and Cu2+ ions when the alginate is isolated and acting as bioadsorbents, adsorption capacities greater than those found for the alga were observed, indicating that it is the main component responsible for the removal of metallic ions. For Zn2+ and Cd2+ ions, greater bioadsorption capacities were observed for the alga, indicating that other functional groups of the alga, such as sulfates and amino, are also important in the bioadsorption of these ions.

  12. Resonant absorption effects induced by polarized laser light irradiating thin foils in the TNSA regime of ion acceleration

    Science.gov (United States)

    Torrisi, L.; Badziak, J.; Rosinski, M.; Zaras-Szydlowska, A.; Pfeifer, M.; Torrisi, A.

    2016-04-01

    Thin foils were irradiated by short pulsed lasers at intensities of 1016-19W/cm2 in order to produce non-equilibrium plasmas and ion acceleration from the target-normal-sheath-acceleration (TNSA) regime. Ion acceleration in forward direction was measured by SiC detectors and ion collectors used in the time-of-flight configuration. Laser irradiations were employed using p-polarized light at different incidence angles with respect to the target surface and at different focal distances from the target surface. Measurements demonstrate that resonant absorption effects, due to the plasma wave excitations, enhance the plasma temperature and the ion acceleration with respect to those performed without to use of p-polarized light. Dependences of the ion flux characteristics on the laser energy, wavelength, focal distance and incidence angle will be reported and discussed.

  13. Wavefront coding for fast, high-resolution light-sheet microscopy (Conference Presentation)

    Science.gov (United States)

    Olarte, Omar E.; Licea-Rodriguez, Jacob; Loza-Alvarez, Pablo

    2017-02-01

    Some biological experiments demand the observation of dynamics processes in 3D with high spatiotemporal resolution. The use of wavefront coding to extend the depth-of-field (DOF) of the collection arm of a light-sheet microscope is an interesting alternative for fast 3D imaging. Under this scheme, the 3D features of the sample are captured at high volumetric rates while the light sheet is swept rapidly within the extended DOF. The DOF is extended by coding the pupil function of the imaging lens by using a custom-designed phase mask. A posterior restoration step is required to decode the information of the captured images based on the applied phase mask [1]. This hybrid optical-digital approach is known as wavefront coding (WFC). Previously, we have demonstrated this method for performing fast 3D imaging of biological samples at medium resolution [2]. In this work, we present the extension of this approach for high-resolution microscopes. Under these conditions, the effective DOF of a standard high NA objective is of a few micrometers. Here we demonstrate that by the use of WFC, we can extend the DOF more than one order of magnitude keeping the high-resolution imaging. This is demonstrated for two designed phase masks using Zebrafish and C. elegans samples. [1] Olarte, O.E., Andilla, J., Artigas, D., and Loza-Alvarez, P., "Decoupled Illumination-Detection Microscopy. Selected Optics in Year 2105," in Optics and Photonics news 26, p. 41 (2015). [2] Olarte, O.E., Andilla, J., Artigas, D., and Loza-Alvarez, P., "Decoupled illumination detection in light sheet microscopy for fast volumetric imaging," Optica 2(8), 702 (2015).

  14. submitter Light Extraction From Scintillating Crystals Enhanced by Photonic Crystal Structures Patterned by Focused Ion Beam

    CERN Document Server

    Modrzynski, Pawel; Knapitsch, Arno; Kunicki, Piotr; Lecoq, Paul; Moczala, Magdalena; Papakonstantinou, Ioannis; Auffray, Etiennette

    2016-01-01

    “Photonic Crystals (PhC)” have been used in a variety of fields as a structure for improving the light extraction efficiency from materials with high index of refraction. In previous work we already showed the light extraction improvement of several PhC covered LYSO crystals in computer simulations and practical measurements. In this work, new samples are made using different materials and techniques which allows further efficiency improvements. For rapid prototyping of PhC patterns on scintillators we tested a new method using “Focused Ion Beam (FIB)” patterning. The FIB machine is a device similar to a “Scanning Electron Microscope (SEM)”, but it uses ions (mainly gallium) instead of electrons for the imaging of the samples' surface. The additional feature of FIB devices is the option of surface patterning in nano-scale which was exploited for our samples. Three samples using FIB patterning have been produced. One of them is a direct patterning of the extraction face of a 0.8×0.8×10 $mm^3$ LYS...

  15. Optogenetics in Developmental Biology: using light to control ion flux-dependent signals in Xenopus embryos.

    Science.gov (United States)

    Spencer Adams, Dany; Lemire, Joan M; Kramer, Richard H; Levin, Michael

    2014-01-01

    Developmental bioelectricity, electrical signaling among non-excitable cells, is now known to regulate proliferation, apoptosis, gene expression, and patterning during development. The extraordinary temporal and spatial resolution offered by optogenetics could revolutionize the study of bioelectricity the same way it has revolutionized neuroscience. There is, however, no guide to adapting optogenetics to patterning systems. To fill this gap, we used optogenetic reagents, both proteins and photochemical switches, to vary steady-state bioelectrical properties of non-spiking embryonic cells in Xenopus laevis. We injected mRNA for various proteins, including Channelrhodopsins and Archaerhodopsin, into 1-8 cell embryos, or soaked embryos in media containing photochemical switches, then examined the effect of light and dark on membrane voltage (Vmem) using both electrodes and fluorescent membrane voltage reporters. We also scored tadpoles for known effects of varying Vmem, including left-right asymmetry disruption, hyperpigmentation, and craniofacial phenotypes. The majority of reagents we tested caused a significant increase in the percentage of light-exposed tadpoles showing relevant phenotypes; however, the majority of reagents also induced phenotypes in controls kept in the dark. Experiments on this "dark phenotype" yielded evidence that the direction of ion flux via common optogenetic reagents may be reversed, or unpredictable in non-neural cells. When used in combination with rigorous controls, optogenetics can be a powerful tool for investigating ion-flux based signaling in non-excitable systems. Nonetheless, it is crucial that new reagents be designed with these non-neural cell types in mind.

  16. Serum levels of immunoglobulin free light chains in patients with chronic hepatitis C presenting cryoglobulinemia.

    Science.gov (United States)

    Oliveira, Isabela S; Cabral, Milena S; Jesus, Larissa S; Paraná, Raymundo; Atta, Ajax M; Sousa Atta, Maria Luiza B

    2014-01-01

    Hepatitis C virus (HCV) infects B-lymphocytes, provokes cellular dysfunction and causes lymphoproliferative diseases such as cryoglobulinemia and non-Hodgkin's B-cell lymphoma. In the present study, we investigated the serum levels of kappa and lambda free light chains (FLC) of immunoglobulins and the kappa/lambda FLC ratio in Brazilian patients with chronic HCV infection and cryoglobulinemia. We also analyzed the immunochemical composition of the cryoglobulins in these patients. Twenty-eight cryoglobulinemic HCV patients composed the target group, while 37 HCV patients without cryoglobulinemia were included as controls. The median levels of kappa and lambda FLC were higher in patients with cryoglobulinemia compared to controls (p=0.001 and p=0.003, respectively), but the kappa/lambda FLC ratio was similar in patients with and without cryoglobulinemia (p>0.05). The median FLC ratio was higher in HCV patients presenting with advanced fibrosis of the liver compared to HCV patients without fibrosis (p=0.004). Kappa and lambda FLC levels were strongly correlated with the IgA, IgG and IgM levels in the patients with cryoglobulinemia. In patients without cryoglobulinemia, the kappa FLC level was only correlated with the IgG level, whereas the lambda FLC were weakly correlated with the IgA, IgG and IgM levels. An immunochemical pattern of mixed cryoglobulins (MC), predominantly IgM, IgG, IgA and kappa light chain, was verified in these immune complexes. We concluded that HCV-infected patients presenting cryoglobulinemia have vigorous polyclonal B-lymphocyte activation due to chronic HCV infection and persistent immune stimulation.

  17. Halo collimation of light and heavy ions in the FAIR synchrotron SIS100

    Energy Technology Data Exchange (ETDEWEB)

    Prokhorov, Ivan [TU Darmstadt (Germany); Strasik, Ivan [GSI, Darmstadt (Germany); Boine-Frankenheim, Oliver [TU Darmstadt (Germany); GSI, Darmstadt (Germany)

    2013-07-01

    The halo collimation system in the FAIR synchrotron SIS100 is needed to prevent an interception of the beam halo particles by the accelerator structure. The two-stage betatron collimation system is considered for operation with protons and fully-stripped ions. An adequate numerical simulation of the collimation system performance taking into account a precise description of the following processes: 1) particle scattering by the primary collimator; 2) inelastic nuclear interaction of the ions with the collimator foil; 3) momentum losses during the interaction with the collimator foil; 4) multi-turn tracking of the particles with the collimation optics included. The concept of the halo collimation, the current status of research and future plans are presented. Scattering processes and momentum losses were analytically estimated for various ion species and energies; analytical results were compared with the numerical simulations by the ATIMA code. Preliminary results of particle tracking using MAD-X code were obtained.

  18. A Mathematical Devoloped Model for Light Ion Beam Interactions with Plasma

    CERN Document Server

    Mirfayzi, S R

    2011-01-01

    Light Ion Beams are providing an efficient system for high energy applications using confinement reaction (ICF). This paper will demonstrate the mathematical properties of ion beams leaving ICF reactors and hitting a solid target. A single Hydrogen heavy nucleus current has been demonstrated using Child-Langmuir in an infinite radius as it leaves the reactor chamber. The maximum energy emission has been recorded by examining the total energy loss of the beam pulse using Bethe-Bloch (dE/dx) where it hits the target and forming plasma. Also the target has been analysed by measuring the induction energy, drift and collision current. A set of formula has been developed for charge and current neutrality, the ion beam is being rotated in azimuthal direction, this induces self-magnetism in this purposes. The concept of self-magnetism Er and Br also has been introduced to the rotating-propagating beam inverse to the beam current through ionized and neutral gas. This has been advanced by developing a set of magnetic f...

  19. Visible Light Induced Photocatalysis of Cerium Ion Modified Titania Sol and Nanocrystallites

    Institute of Scientific and Technical Information of China (English)

    Yibing XIE; Chunwei YUAN

    2004-01-01

    The cerium ion(Ce4+) doped titania sol and nanocrystallites were prepared by chemical coprecipitation-peptization and hydrothermal synthesis methods, respectively. The X-ray diffraction pattern shows that Ce4+-TiO2 xerogel powder has semicrystalline structure and thermal sintering sample has crystalline structure. Ce4+-TiO2 nanocrystallites are composed of the major anatase phase titania (88.82 wt pct) and a small amount of crystalline cerium titanate.AFM micrograph shows that primary particle size of well-dispersed ultrafine sol particles is below 15 nm in diameter.The particle sizes are 30 nm for xerogel sample and 70 nm for nanocrystallites sample, which is different from the estimated values (2.41 nm and 4.53 nm) by XRD Scherrer's formula. The difference is mainly due to aggregation of nanocrystallites. The experimental results exhibit that photocatalysts of Ce4+-TiO2 sol and nanocrystallites have the ability to photodegrade reactive brilliant red dye (X-3B) under visible light irradiation with the ion-TiO2/VIS/dye system. Moreover, Ce4+ doped titania sol has shown higher efficiency than the nanocrystallites sample in respect of potocatalytic activity. Meanwhile, dye photodegradation mechanisms are proposed to different photocatalytic reaction systems, which are dye photosensitization, ion-dye photosensitization and interband photocatalysis & dye photosensitization with respect to TiO2 nanocrystallites, Ce4+-TiO2 sol and Ce4+-TiO2 nanocrystallites system.

  20. Tunable high-refractive index hybrid for solution-processed light management devices (Conference Presentation)

    Science.gov (United States)

    Bachevillier, Stefan

    2016-10-01

    After the use of highly efficient but expensive inorganic optical materials, solution-processable polymers and hybrids have drawn more and more interest. Our group have recently developed a novel polymer-based hybrid optical material from titanium oxide hydrate exhibiting an outstanding set of optical and material properties. Firstly, their low cost, processability and cross-linked states are particularly attractive for many applications. Moreover, a high refractive index can be repeatedly achieved while optical losses stays considerably low over the entire visible and near-infrared wavelength regime. Indeed, the formation of inorganic nanoparticles, usually present in nanocomposites, is avoided by a specific formulation process. Even more remarkably, the refractive index can be tuned by either changing the inorganic content, using different titanium precursors or via a low-temperature curing process. A part of our work is focused on the reliable optical characterization of these properties, in particular a microscope-based setup allowing in-situ measurement and sample mapping has been developed. Our efforts are also concentrated on various applications of these exceptional properties. This hybrid material is tailored for photonic devices, with a specific emphasis on the production of highly efficient solution processable Distributed Bragg Reflectors (DBR) and anti-reflection coatings. Furthermore, waveguides can be fabricated from thin films along with in-coupling and out-coupling structures. These light managements structures are particularly adapted to organic photovoltaic cells (OPVs) and light emitting diodes (OLEDs).

  1. Recent advances in the science and engineering of organic light-emitting diodes (Conference Presentation)

    Science.gov (United States)

    Kippelen, Bernard; Gaj, Michael P.; Zhang, Xiaoqing; Choi, Sangmoo; Fuentes-Hernandez, Canek; Zhang, Yadong; Barlow, Stephen; Marder, Seth R.; Voit, Walter E.; Wei, Andrew

    2016-09-01

    In this talk, we will discuss recent advances in the science and engineering of organic light-emitting diodes (OLEDs). First, we will focus on materials in which light emission involves the process of thermally activated delayed fluorescence (TADF). In these materials, triplet excited states can convert into optically emissive singlet excited states by reverse intersystem crossing, allowing for nearly 100% internal quantum efficiency. This process can be used to design a new class of materials that are all organic, offering a lower cost alternative to conventional electrophosphorescent materials that contain heavy and expensive elements such as Pt and Ir. We will discuss molecular design strategies and present examples of materials that can be used as emitters or hosts in the emissive layer. In a second part of this talk, we will review recent progress in fabricating OLEDs on shape memory polymer substrates (SMPs). SMPs are mechanically active, smart materials that can exhibit a significant drop in modulus once an external stimulus such as temperature is applied. In their rubbery state upon heating, the SMP can be easily deformed by external stresses into a temporary geometric configuration that can be retained even after the stress is removed by cooling the SMP to below the glass transition temperature. Reheating the SMP causes strain relaxation within the polymer network and induces recovery of its original shape. We will discuss how these unique mechanical properties can also be extended to a new class of OLEDs.

  2. [Study on the orientation of liquid crystals presented on the glass substrates spin-coated and functionalized with copper ions].

    Science.gov (United States)

    Wang, Shiming; Xiong, Xingliang; Zhang, Yan; Li, Guang; Chen, Mengmeng

    2013-06-01

    A stable, uniform, easily implemented, LC-based chemical and biological sensor substrate for orientations of liquid crystals (LCs) for a long-term is urgently needed for medical applications of the sensors. We proposed a use of spin-coating of copper perchlorate (Cu(ClO4)2), with five different concentrations(0-100mmol/L), directly on glass slides for fabricating a layer of chemically-sensitive copper ions. Observing the transmitted light with a polarized microscope, we found the luminosity of the light propagated through sensors deposited with copper ions started to weaken gradually after a certain time. The higher was the concentration of copper ions covered on the glass substrates of the sensors, the faster the weakening occurred, and the less time was needed for transmitted light to turn completely dark. But there was no change in luminosity of the transmitted light for the sensors without Cu(ClO4)2 spin-coating even after stored at room temperature (25 degrees C) for a whole day. When the Cu(ClO4)2 deposited sensors were stored within a drying oven at room temperature (25 degrees C) for 2 months, it was found that there vas almost no change in luminosity of the transmitted lights. The results showed that all the thin films of LC on glass slides functionalized with Cu(ClO4)2 could keep homeotropic and stable orientation for a long time; the concentration of Cu (ClO4)2I has an influence on the orientation response speed of LC from planar to perpendicular orientation.

  3. Theoretical predictions for ionization cross sections of DNA nucleobases impacted by light ions

    Energy Technology Data Exchange (ETDEWEB)

    Champion, C; Lekadir, H; Hanssen, J [Laboratoire de Physique Moleculaire et des Collisions, ICPMB (FR CNRS 2843), Institut de Physique, Universite Paul Verlaine-Metz, 1 bd Arago, 57078 Metz Cedex 3 (France); Galassi, M E; Fojon, O; Rivarola, R D, E-mail: champion@univ-metz.f [Instituto de Fisica Rosario, CONICET and Universidad Nacional de Rosario, Avenida Pellegrini 250, 2000 Rosario (Argentina)

    2010-10-21

    Induction of DNA double strand breaks after irradiation is considered of prime importance for producing radio-induced cellular death or injury. However, up to now ion-induced collisions on DNA bases remain essentially experimentally approached and a theoretical model for cross section calculation is still lacking. Under these conditions, we here propose a quantum mechanical description of the ionization process induced by light bare ions on DNA bases. Theoretical predictions in terms of differential and total cross sections for proton, {alpha}-particle and bare ion carbon beams impacting on adenine, cytosine, thymine and guanine bases are then reported in the 10 keV amu{sup -1}-10 MeV amu{sup -1} energy range. The calculations are performed within the first-order Born approximation (FBA) with biological targets described at the restricted Hartree-Fock level with geometry optimization. Comparisons to recent theoretical data for collisions between protons and cytosine point out huge discrepancies in terms of differential as well as total cross sections whereas very good agreement is shown with our previous classical predictions, especially at high impact energies (E{sub i} {>=} 100 keV amu{sup -1}). Finally, in comparison to the rare existing experimental data a systematic underestimation is observed in particular for adenine and thymine whereas a good agreement is reported for cytosine. Thus, further improvements appear as necessary, in particular by using higher order theories like the continuum-distorted-wave one in order to obtain a better understanding of the underlying physics involved in such ion-DNA reactions.

  4. Gold nanoparticle-decorated keggin ions/TiO2 photococatalyst for improved solar light photocatalysis.

    Science.gov (United States)

    Pearson, Andrew; Jani, Harit; Kalantar-zadeh, Kourosh; Bhargava, Suresh K; Bansal, Vipul

    2011-06-07

    We demonstrate a facile localized reduction approach to synthesizing a Au nanoparticle-decorated Keggin ion/TiO(2) photococatalyst for improved solar light photocatalysis application. This has been achieved by exploiting the ability of TiO(2)-bound Keggin ions to act as a UV-switchable, highly localized reducing agent. Notably, the approach proposed here does not lead to contamination of the resultant cocatalyst with free metal nanoparticles during aqueous solution-based synthesis. The study shows that for Keggin ions (phosphotungstic acid, PTA), being photoactive molecules, the presence of both Au nanoparticles and PTA on the TiO(2) surface in a cocatalytic system can have a dramatic effect on increasing the photocatalytic performance of the composite system, as opposed to a TiO(2) surface directly decorated with metal nanoparticles without a sandwiched PTA layer. The remarkable increase in the photocatalytic performance of these materials toward the degradation of a model organic Congo red dye correlates to an increase of 2.7-fold over that of anatase TiO(2) after adding Au to it and 4.3-fold after introducing PTA along with Au to it. The generalized localized reduction approach to preparing TiO(2)-PTA-Au cocatalysts reported here can be further extended to other similar systems, wherein a range of metal nanoparticles in the presence of different Keggin ions can be utilized. The composites reported here may have wide potential implications toward the degradation of organic species and solar cell applications.

  5. Removal of chromium and toxic ions present in mine drainage by Ectodermis of Opuntia

    Energy Technology Data Exchange (ETDEWEB)

    Barrera, Hector [Universidad Autonoma del Estado de Mexico, Facultad de Quimica, Paseo Colon interseccion Paseo Tollocan S/N, C.P. 50120, Toluca, Estado de Mexico (Mexico); Urena-Nunez, Fernando [Instituto Nacional de Investigaciones Nucleares, A.P.18-1027, Col. Escandon, Delegacion Miguel Hidalgo, C.P. 11801, Mexico, D.F. (Mexico); Bilyeu, Bryan [University of North Texas, Department of Materials Science and Engineering, P.O. Box 305310, Denton, TX 76203-5310 (United States); Barrera-Diaz, Carlos [Universidad Autonoma del Estado de Mexico, Facultad de Quimica, Paseo Colon interseccion Paseo Tollocan S/N, C.P. 50120, Toluca, Estado de Mexico (Mexico)]. E-mail: cbarrera@uaemex.mx

    2006-08-25

    This work presents conditions for hexavalent and trivalent chromium removal from aqueous solutions using natural, protonated and thermally treated Ectodermis of Opuntia. A removal of 77% of Cr(VI) and 99% of Cr(III) can be achieved. The sorbent material is characterized using scanning electron microscopy, energy dispersive X-ray spectroscopy, infrared spectroscopy, thermogravimetric analysis, before and after the contact with the chromium containing aqueous media. The results obtained from the characterization techniques indicate that the metal ion remains on the surface of the sorbent material. The percentage removal is found to depend on the initial chromium concentration and pH. The Cr(VI) and Cr(III) uptake process is maximum at pH 4, using 0.1 g of sorbent per liter of aqueous solution. The natural Ectodermis of Opuntia showed a chromium adsorption capacity that was adequately described by the Langmuir adsorption isotherm. Finally, an actual mine drainage sample that contained Cd, Cr, Cu, Fe Zn, Ni and Pb was tested under optimal conditions for chromium removal and Ectodermis of Opuntia was found to be a suitable sorbent material. The use of this waste material for the treatment of metal-containing aqueous solutions as well as mine drainage is effective and economical.

  6. Multi Dark Lens Simulations: weak lensing light-cones and data base presentation

    Science.gov (United States)

    Giocoli, Carlo; Jullo, Eric; Metcalf, R. Benton; de la Torre, Sylvain; Yepes, Gustavo; Prada, Francisco; Comparat, Johan; Göttlober, Stefan; Kyplin, Anatoly; Kneib, Jean-Paul; Petkova, Margarita; Shan, Huan Yuan; Tessore, Nicolas

    2016-09-01

    In this paper we present a large data base of weak lensing light cones constructed using different snapshots from the Big MultiDark simulation (BigMDPL). The ray-tracing through different multiple plane has been performed with the GLAMER code accounting both for single source redshifts and for sources distributed along the cosmic time. This first paper presents weak lensing forecasts and results according to the geometry of the VIPERS-W1 and VIPERS-W4 field of view. Additional fields will be available on our data base and new ones can be run upon request. Our data base also contains some tools for lensing analysis. In this paper we present results for convergence power spectra, one point and high order weak lensing statistics useful for forecasts and for cosmological studies. Covariance matrices have also been computed for the different realizations of the W1 and W4 fields. In addition we compute also galaxy-shear and projected density contrasts for different halo masses at two lens redshift according to the CFHTLS source redshift distribution both using stacking and cross-correlation techniques, finding very good agreement.

  7. Extraction of alginate biopolymer present in marine alga sargassum filipendula and bioadsorption of metallic ions

    OpenAIRE

    Sirlei Jaiana Kleinübing; Frederico Gai; Caroline Bertagnolli; Meuris Gurgel Carlos da Silva

    2013-01-01

    This paper studies the bioadsorption of Pb2+, Cu2+, Cd2+ and Zn2+ ions by marine alga Sargassum filipendula and by the alginate biopolymer extracted from this alga. The objective is to evaluate the importance of this biopolymer in removing different metallic ions by the marine alga S. filipendula. In the equilibrium study, the same affinity order was observed for both bioadsorbents: Pb2+ > Cu2+ > Zn2+ > Cd2+. For Pb2+ and Cu2+ ions when the alginate is isolated and acting as bioadsorbents, ad...

  8. Experimental Study of an ion cyclon resonance accelerator presentation of his thesis

    CERN Document Server

    Ramsell, C T

    1999-01-01

    The Ion Cyclotron Resonance Accelerator (ICRA) uses the operating principles of cyclotrons and gyrotrons. The novel geometry of the ICRA allows an ion beam to drift axially while being accelerated in the azimuthal direction. Previous work on electron cyclotron resonance acceleration used waveguide modes to accelerate an electron beam [5]. This research extends cyclotron resonance acceleration to ions by using a high field superconducting magnet and an rf driven magnetron operating at a harmonic of the cyclotron frequency. The superconducting solenoid provides an axial magnetic field for radial confinement and an rf driven magnetron provides azimuthal electric fields for acceleration. The intent of the ICRA concept is to create an ion accelerator which is simple, compact, lightweight, and inexpensive. Furthermore, injection and extraction are inherently simple since the beam drifts through the acceleration region. However, use of this convenient geometry leads to an accelerated beam with a large energy spread....

  9. Light pattern preservation in rodent's cortical tissue during optogenetic neuro-stimulation (Conference Presentation)

    Science.gov (United States)

    Azimipour, Mehdi; Atry, Farid; Pashaie, Ramin

    2016-03-01

    Optogenetics provides a tool for modulating activity of specific cell types by light pulses. Different light delivery mechanisms such as single optical fiber implanted on a skull or patterned illumination can be employed to direct light to a target area. For a highly scattering medium such as brain tissue, light distribution significantly depends on the scattering parameters of the tissue as well as the inherent inhomogeneity of the specimen. For in vivo studies, blood vessels which have considerable absorption coefficient in the visible spectrum play a major role in producing such inhomogeneity. Therefore, detailed information about brain optical properties and network of blood vessels which was ignored in previous studies is necessary to accurately predict light distribution and designing light delivery mechanism during optogenetic experiments to achieve the desired optical stimulation. In this paper, light pattern preservation while considering the impact of blood vessels is investigated in a rat cortex. First, the typical optical properties of rat cortical tissue were extracted by employing double integrated sphere technique, and then, optical coherence tomography was employed to obtain structure of blood vessels on the cortex. By combining the extracted optical properties and the network of blood vessels, a three-dimensional model of a rat cortical tissue was developed. Then, a Monte Carlo simulation code was used to predict light distribution in this model for different light source configurations and wavelengths. The results confirm that presence of vessels can significantly impact the light pattern in the tissue and affect the practical depth of penetration.

  10. Study on the interactional behaviour of transition metal ions with myoglobin: A detailed calorimetric, spectroscopic and light scattering analysis

    Science.gov (United States)

    Kaur, Amandeep; Banipal, Parampaul K.; Banipal, Tarlok S.

    2017-03-01

    The energetics and the impact on the conformation of heme containing protein myoglobin (Mb) due to the binding of three transition metal ions (Zn2 +, Ni2 +, and Mn2 +) have been investigated using isothermal titration calorimetry (ITC), dynamic light scattering (DLS), UV-vis, and circular dichroism (CD) spectroscopy under physiological conditions. The binding affinity of the order of 104 M- 1 has been observed for all metal ions from calorimetry as well as from absorption spectroscopy. The binding of these metal ions with Mb is a spontaneous process that exposes the hydrophobic groups away from the protein core as exhibited by the negative Gibbs free energy change (ΔG) and positive heat capacity change (ΔCp) values. Both light scattering and CD results demonstrates that the binding of Zn2 + and Mn2 + ions with Mb results in the folding whereas Ni2 + ion results in the unfolding of the protein. No direct interactions among the transition metal ions and heme moiety of Mb has been observed from absorption study. The results of these studies reveals that Mn2 + ion influences the biological functions of Mb to a larger extent in spite of its lowest affinity followed by Zn2 + and Ni2 + ions.

  11. Presentation

    Directory of Open Access Journals (Sweden)

    Paulo Henrique Freire Vieira

    2013-12-01

    Full Text Available This dossier focuses on one of the essential debate topics today about the territorial dimension of the new development strategies concerned with the worsening of the global socioecological crisis, that is: the challenges related to the activation and integration in networks of localized agri-food systems. For its composition, some contributions presented and debated during the VI International Conference on Localized Agri-food System - The LAFS facing the opportunities and challenges of the new global context have been gathered. The event took place in the city of Florianópolis, from May 21th to 25th of 2013. The event was promoted by the Federal University of Santa Catarina (UFSC and by the Center for the International Cooperation on Agricultural Research for Development (CIRAD. Besides UFSC and CIRAD, EPAGRI, State University of Santa Catarina (UDESC, as well as research institutes and universities from other states (UFMG, IEA/SP, UFS, UFRGS and Mexican and Argentinian partners from the RED SIAL Latino Americana also participated in the organization of lectures, discussion tables and workshops.

  12. JT-60 negative ion beam NBI apparatus. Present state of its construction and initial experimental results

    Energy Technology Data Exchange (ETDEWEB)

    Kuriyama, Masaaki [Japan Atomic Energy Research Inst., Naka, Ibaraki (Japan). Naka Fusion Research Establishment

    1997-02-01

    The NBI (Neutral Beam Injection) apparatus used for negative ion at first in the world, has an aim to actually prove heating and electric current drive with high density plasma at the JT-60 and to constitute physical and technical bases for selection and design of heating apparatus of ITER (International Thermal Nuclear Fusion Experimental Reactor). Construction of 500 KeV negative ion NBI apparatus for the JT-60 started to operate on 1993 was completed at March, 1996. On the way, at a preliminary test on forming and acceleration of the negative ion beam using a portion of this apparatus, 400 KeV and 13.5 A/D of the highest deuterium negative ion beam acceleration in the world was obtained successfully, which gave a bright forecasting of the plasma heating and electric current drive experiment using the negative ion NBI apparatus. After March, 1996, some plans to begin beam incident experiment at the JT-60 using the negative ion NBI apparatus and to execute the heating and electric current drive experiment at the JT-60 under intending increase of beam output are progressed. (G.K.)

  13. Evaluation of anemia diagnosis based on elastic light scattering (Conference Presentation)

    Science.gov (United States)

    Tong, Lieshu; Wang, Xinrui; Xie, Dengling; Chen, Xiaoya; Chu, Kaiqin; Dou, Hu; Smith, Zachary J.

    2017-03-01

    Currently, one-third of humanity is still suffering from anemia. In China the most common forms of anemia are iron deficiency and Thalassemia minor. Differentiating these two is the key to effective treatment. Iron deficiency is caused by malnutrition and can be cured by iron supplementation. Thalassemia is a hereditary disease in which the hemoglobin β chain is lowered or absent. Iron therapy is not effective, and there is evidence that iron therapy may be harmful to patients with Thalassemia. Both anemias can be diagnosed using red blood cell morphology: Iron deficiency presents a smaller mean cell volume compared to normal cells, but with a wide distribution; Thalassemia, meanwhile, presents a very small cell size and tight particle size distribution. Several researchers have proposed diagnostic indices based on red cell morphology to differentiate these two diseases. However, these indices lack sensitivity and specificity and are constructed without statistical rigor. Using multivariate methods we demonstrate a new classification method based on red cell morphology that diagnoses anemia in a Chinese population with enough accuracy for its use as a screening method. We further demonstrate a low cost instrument that precisely measures red cell morphology using elastic light scattering. This instrument is combined with an automated analysis program that processes scattering data to report red cell morphology without the need for user intervention. Despite using consumer-grade components, when comparing our experimental results with gold-standard measurements, the device can still achieve the high precision required for sensing clinically significant changes in red cell morphology.

  14. Presentation

    Directory of Open Access Journals (Sweden)

    Eduardo Vicente

    2013-06-01

    Full Text Available In the present edition of Significação – Scientific Journal for Audiovisual Culture and in the others to follow something new is brought: the presence of thematic dossiers which are to be organized by invited scholars. The appointed subject for the very first one of them was Radio and the invited scholar, Eduardo Vicente, professor at the Graduate Course in Audiovisual and at the Postgraduate Program in Audiovisual Media and Processes of the School of Communication and Arts of the University of São Paulo (ECA-USP. Entitled Radio Beyond Borders the dossier gathers six articles and the intention of reuniting works on the perspectives of usage of such media as much as on the new possibilities of aesthetical experimenting being build up for it, especially considering the new digital technologies and technological convergences. It also intends to present works with original theoretical approach and original reflections able to reset the way we look at what is today already a centennial media. Having broadened the meaning of “beyond borders”, four foreign authors were invited to join the dossier. This is the first time they are being published in this country and so, in all cases, the articles where either written or translated into Portuguese.The dossier begins with “Radio is dead…Long live to the sound”, which is the transcription of a thought provoking lecture given by Armand Balsebre (Autonomous University of Barcelona – one of the most influential authors in the world on the Radio study field. It addresses the challenges such media is to face so that it can become “a new sound media, in the context of a new soundscape or sound-sphere, for the new listeners”. Andrew Dubber (Birmingham City University regarding the challenges posed by a Digital Era argues for a theoretical approach in radio studies which can consider a Media Ecology. The author understands the form and discourse of radio as a negotiation of affordances and

  15. Presentation

    Directory of Open Access Journals (Sweden)

    Helmut Renders

    2008-10-01

    Full Text Available We present to our esteemed readers the second edition of our journal for 2008. We have chosen the theme “The life and work of Prof. Dr. Jürgen Moltmann” as its special emphasis. It is our way to pay homage to J. Moltmann in the year the Universidade Metodista de São Paulo awards him an honorary Doctor Honoris Causa degree. Sincethe seventies, Moltmann and Latin America have been in dialog. In his emblematic work “A Theology of Liberation”, Gustavo Gutiérrez, the Catholic, discussed with Moltmann, the Reformed, the relationship between eschatology and history (GUTIÉRREZ, Gustavo.Teologia da Libertação. 5ª edição. Petrópolis, RJ: Vozes, 1985, p. 27, 137-139. A dialog held in the premises of IMS, which nowadays is called UMESP, has produced the little book “Passion for life” (MOLTMANN, Jürgen. Paixão pela vida. São Paulo, SP: ASTE - Associaçãode Seminários Teológicos Evangélicos, 1978.In the following years, the wide theological work of J. Moltmann went all the way from debates to congresses and has conquered the classrooms. Most probably, J. Moltmann is nowadays the most widely read European author in Brazilian theological seminaries. Thisrecognition can only be held in unison and the wide response to our request for articles confirms the huge repercussion that Moltmann’s work has been having up to today in Brazil. The ecumenical theologian J. Moltmann is ecumenically read. We believe that thisway we may be better equipped to answer to anyone who asks us for the reason there is hope in us. We have organized the articles on J. Moltmann’s theology according to the original publication date of the books dealt with in each essay. We also communicate that some articles which were originally requested for this edition of the journal will be published in the journal Estudos de Regilião in May 2009.As it is usual with the journal Caminhando, we have, besides this thematic emphasis, yet other contributions in the areas of

  16. Detailed analysis of the cell-inactivation mechanism by accelerated protons and light ions

    Energy Technology Data Exchange (ETDEWEB)

    Kundrat, Pavel [Institute of Physics, Academy of Sciences of the Czech Republic, Na Slovance 2, CZ-182 21 Praha 8 (Czech Republic)

    2006-03-07

    A detailed study of the biological effects of diverse quality radiations, addressing their biophysical interpretation, is presented. Published survival data for V79 cells irradiated by monoenergetic protons, helium-3, carbon and oxygen ions and for CHO cells irradiated by carbon ions have been analysed using the probabilistic two-stage model of cell inactivation. Three different classes of DNA damage formed by traversing particles have been distinguished, namely severe single-track lesions which might lead to cell inactivation directly, less severe lesions where cell inactivation is caused by their combinations and lesions of negligible severity that can be repaired easily. Probabilities of single ions forming these lesions have been assessed in dependence on their linear energy transfer (LET) values. Damage induction probabilities increase with atomic number and LET. While combined lesions play a crucial role at lower LET values, single-track damage dominates in high-LET regions. The yields of single-track lethal lesions for protons have been compared with Monte Carlo estimates of complex DNA lesions, indicating that lethal events correlate well with complex DNA double-strand breaks. The decrease in the single-track damage probability for protons of LET above approximately 30 keV {mu}m{sup -1}, suggested by limited experimental evidence, is discussed, together with the consequent differences in the mechanisms of biological effects between protons and heavier ions. Applications of the results in hadrontherapy treatment planning are outlined.

  17. Presentation

    Directory of Open Access Journals (Sweden)

    Nicanor Lopes

    2010-11-01

    Full Text Available The Journal Caminhando debuts with a new editorial format: eachmagazine will have a Dossier.In 2010 Christianity celebrated the centenary of Edinburgh. TheWorld Missionary Conference in Edinburgh in 1910 is regarded by manyas missiological watershed in the missionary and ecumenical movement.So the Faculty of Theology of the Methodist Church (FATEO decidedto organize a Wesleyan Week discussing the issue of mission. For anevent of this magnitude FATEO invited the Rev. Dr. Wesley Ariarajah,Methodist pastor and teacher of Sri Lanka with extensive experience inpastoral ministry in local churches and professor of History of Religionsand the New Testament at the Theological College of Lanka, maintainedby the Protestant Churches in Sri Lanka. In 1981 he was invited to jointhe World Council of Churches, where he presided for over ten years theCouncil of Interreligious Dialogue. From 1992 he served as Deputy GeneralSecretary of the WCC.The following texts are not the speeches of the Rev. Dr. WesleyAriarajah, for they will be published separately. Nevertheless, the journaldialogs with the celebrations of the centenary of Edinburgh, parting formthe intriguing theme: "Mission in the 21st century in Brazil". After all, howis it that mission takes place among us in personal, church, and communityactivities?Within the Dossier, as common to the journal, the textos are organizedas follows: Bible, Theology / History and Pastoral Care. Other items thatdo not fit within the Dossier, but, do articulate mission, can be found inthe section Declarations and Documents and Book Reviews.The authors of the Dossier have important considerations in buildinga contemporary missiological concept considering Brazilian reality.Anderson de Oliveira, in the Bible-Section, presents a significantexegeses of Matthew 26.6-13. What does it mean when Jesus is quotedwith the words: "For the poor always ye have with you, but me ye havenot always." Is this declaration challenging the gospels

  18. Theoretical investigations of electron emission after water vapour ionization by light ion impact

    Energy Technology Data Exchange (ETDEWEB)

    Champion, C. [Laboratoire de Physique Moleculaire et des Collisions, ICPMB (FR2843), Institut de Physique, Universite Paul Verlaine-Metz, 1 Boulevard Arago, 57078 Metz Cedex 3 (France)], E-mail: champion@univ-metz.fr; Dal Cappello, C. [Laboratoire de Physique Moleculaire et des Collisions, ICPMB (FR2843), Institut de Physique, Universite Paul Verlaine-Metz, 1 Boulevard Arago, 57078 Metz Cedex 3 (France)

    2009-03-15

    An ab initio quantum-mechanical treatment is applied for treating the ionization process of water vapour by light ions. In this theoretical model, the initial state of the system is composed of a projectile and a water target described by a plane wave and an accurate one-centre molecular wave function, respectively, whereas the final state is constituted by a slow ejected electron and a scattered projectile represented by a Coulomb wave and a plane wave, respectively. The obtained results are compared to available experimental data in terms of doubly differential cross sections (DDCS), singly differential cross sections (SDCS) and total cross sections (TCS). A good agreement is generally found especially for the SDCS and the TCS.

  19. Relativistic light-shift theory of few-electron systems: Heliumlike highly charged ions

    Science.gov (United States)

    Postavaru, O.; Scafes, A. C.

    2017-09-01

    The light-shift theory of many-electron systems in a laser field is described using the projection operators technique. In heavy ions, the electrons are tightly bound by the Coulomb potential of the nucleus, which prohibits ionization even by strong lasers. However, interaction with the monofrequent laser field leads to dynamic shifts of the electronic energy levels, and the process is treated by second-order time-dependent perturbation theory. In order to treat heliumlike systems, one decomposes the corresponding matrix elements into hydrogenlike matrix elements using the independent particle model. We are applying a fully relativistic description of the electronic states by means of the Dirac equation. Our formalism goes beyond the Stark long-wavelength dipole approximation and takes into account nondipole effects of retardation and interaction with the magnetic field components of the laser beam.

  20. Front versus rear side light-ion acceleration from high-intensity laser-solid interactions

    Science.gov (United States)

    Willingale, L.; Petrov, G. M.; Maksimchuk, A.; Davis, J.; Freeman, R. R.; Matsuoka, T.; Murphy, C. D.; Ovchinnikov, V. M.; Van Woerkom, L.; Krushelnick, K.

    2011-01-01

    The source of ions accelerated from high-intensity laser interactions with thin foil targets is investigated by coating a deuterated plastic layer either on the front, rear or both surfaces of thin foil targets. The originating surface of the deuterons is therefore known and this method is used to assess the relative source contributions and maximum energies using a Thomson parabola spectrometer to obtain high-resolution light-ion spectra. Under these experimental conditions, laser intensity of (0.5-2.5) × 1019 W cm-2, pulse duration of 400 fs and target thickness of 6-13 µm, deuterons originating from the front surface can gain comparable maximum energies as those from the rear surface and spectra from either side can deviate from Maxwellian. Two-dimensional particle-in-cell simulations model the acceleration and show that any presence of a proton rich contamination layer over the surface is detrimental to the deuteron acceleration from the rear surface, whereas it is likely to be less influential on the front side acceleration mechanism.

  1. Visible-Light Excitated Photocatalytic Activity of Rare Earth Metal-Ion-Doped Titania

    Institute of Scientific and Technical Information of China (English)

    谢一兵; 李萍; 袁春伟

    2002-01-01

    The rare earth ion Ce4+ doped TiO2 was prepared by sol-gel method. The average particle sizes are about 10 nm for sol phase and 55 nm for polycrystalline phase. The photocatalytic activities to degrade Reactive Brilliant Red Dye X-3B were investigated. The result reveals that the spectrum response of Ce4+-TiO2 has extended to visible region from the UV region(λ<387 nm) of pure TiO2. Amorphous phase Ce4+-TiO2 sol with an electron scavenger (1.0% atom fraction Ce4+ ion doping amount) shows the capability of the photocatalytic degradation of the dye X-3B as well as the nanocrystallite Ce4+-TiO2 with an interband trap site. Despite of the difference in the morphology of Ce4+-TiO2 photocatalyst, there is no apparent difference in respect of the decoloring effects. Whereas, polycrystalline phase Ce4+-TiO2 exhibits strong photomineralization power in comparison with the amorphous phase. The photocatalytic oxidation mechanisms of the dye molecule mainly involved in the self-photo-sensitization photolysis process by the first excited singlet oxygen (1O2) and photocatalysis process by hydroxyl radicals(*OH) under visible light irradiation.

  2. Cardiac Light Chain Amyloidosis: The Role of Metal Ions in Oxidative Stress and Mitochondrial Damage.

    Science.gov (United States)

    Diomede, Luisa; Romeo, Margherita; Rognoni, Paola; Beeg, Marten; Foray, Claudia; Ghibaudi, Elena; Palladini, Giovanni; Cherny, Robert A; Verga, Laura; Capello, Gian Luca; Perfetti, Vittorio; Fiordaliso, Fabio; Merlini, Giampaolo; Salmona, Mario

    2017-09-20

    The knowledge of the mechanism underlying the cardiac damage in immunoglobulin light chain (LC) amyloidosis (AL) is essential to develop novel therapies and improve patients' outcome. Although an active role of reactive oxygen species (ROS) in LC-induced cardiotoxicity has already been envisaged, the actual mechanisms behind their generation remain elusive. This study was aimed at further dissecting the action of ROS generated by cardiotoxic LC in vivo and investigating whether transition metal ions are involved in this process. In the absence of reliable vertebrate model of AL, we used the nematode Caenorhabditis elegans, whose pharynx is an "ancestral heart." LC purified from patients with severe cardiac involvement intrinsically generated high levels of ROS and when administered to C. elegans induced ROS production, activation of the DAF-16/forkhead transcription factor (FOXO) pathway, and expression of proteins involved in stress resistance and survival. Profound functional and structural ROS-mediated mitochondrial damage, similar to that observed in amyloid-affected hearts from AL patients, was observed. All these effects were entirely dependent on the presence of metal ions since addition of metal chelator or metal-binding 8-hydroxyquinoline compounds (chelex, PBT2, and clioquinol) permanently blocked the ROS production and prevented the cardiotoxic effects of amyloid LC. Innovation and Conclusion: Our findings identify the key role of metal ions in driving the ROS-mediated toxic effects of LC. This is a novel conceptual advance that paves the way for new pharmacological strategies aimed at not only counteracting but also totally inhibiting the vicious cycle of redox damage. Antioxid. Redox Signal. 27, 567-582.

  3. From light to mass: accessing the initial and present-day Galactic globular cluster mass functions

    CERN Document Server

    Bonatto, Charles

    2012-01-01

    The initial and present-day mass functions (ICMF and PDMF, respectively) of the Galactic globular clusters (GCs) are constructed based on their observed luminosities, the stellar evolution and dynamical mass-loss processes, and the mass-to-light ratio (MLR). Under these conditions, a Schechter-like ICMF is evolved for approximately a Hubble time and converted into the luminosity function (LF), which requires finding the values of 5 free parameters: the mean GC age (\\tA), the dissolution timescale of a $10^5 \\ms$ cluster ($\\tau_5$), the exponential truncation mass (\\mc) and 2 MLR parametrising constants. This is achieved by minimising the residuals between the evolved and observed LFs, with the minimum residuals and realistic parameters obtained with MLRs that increase with luminosity (or mass). The optimum PMDFs indicate a total stellar mass of $\\sim4\\times10^7$ \\ms\\ still bound to GCs, representing $\\sim15%$ of the mass in clusters at the beginning of the gas-free evolution. The corresponding ICMFs resemble ...

  4. High catalytic activity of heteropolynuclear cyanide complexes containing cobalt and platinum ions: visible-light driven water oxidation.

    Science.gov (United States)

    Yamada, Yusuke; Oyama, Kohei; Gates, Rachel; Fukuzumi, Shunichi

    2015-05-04

    A near-stoichiometric amount of O2 was evolved as observed in the visible-light irradiation of an aqueous buffer (pH 8) containing [Ru(II) (2,2'-bipyridine)3 ] as a photosensitizer, Na2 S2 O8 as a sacrificial electron acceptor, and a heteropolynuclear cyanide complex as a water-oxidation catalyst. The heteropolynuclear cyanide complexes exhibited higher catalytic activity than a polynuclear cyanide complex containing only Co(III) or Pt(IV) ions as C-bound metal ions. The origin of the synergistic effect between Co and Pt ions is discussed in relation to electronic and local atomic structures of the complexes.

  5. How Can a Lighting Designer Use Light in Buildings For Well-Being? - 'Presented as invited speaker'

    DEFF Research Database (Denmark)

    Christoffersen, Jens

    that these activities [Design Guidance] are unimportant and not rewarding. These forms of publication may not be among those counted towards tenure and promotion decisions, which constitutes a barrier to interdisciplinary research and to its application. Experience suggests that there are other rewards, most notably...... design. Summary: Adequate lighting, both natural and artificial, is important as part of a person's well-being. A description of a person's well-being may be context-specific depending on the building design and include a number of parameters such as daylight and sunlight penetration, window views...... and content of view, enclosed or open space, crowding, visual and acoustical privacy, personal control of ambient conditions etc. Successful daylighting requires trade-offs and optimisation between competing design aspects by skilful integration of the facade layout with the space configuration and the choice...

  6. A Novel Spin-Light Polarimeter for the Electron Ion Collider

    CERN Document Server

    Mohanmurthy, Prajwal

    2013-01-01

    A novel precision polarimeter will go a long way in satisfying the requirements of the precision experiments being planned for a future facility such as the Electron Ion Collider. A polarimeter based on the asymmetry in the spacial distribution of the spin light component of synchrotron radiation will make for a fine addition to the existing-conventional M{\\o}ller and Compton polarimeters. The spin light polarimeter consists of a set of wriggler magnet along the beam that generate synchrotron radiation. The spacial distribution of synchrotron radiation will be measured by an ionization chamber after being collimated. The up-down spacial asymmetry in the transverse plane is used to quantify the polarization of the beam. As a part of the design process, firstly, a rough calculation was drawn out to establish the validity of such an idea. Secondly, the fringe fields of the wriggler magnet was simulated using a 2-D magnetic field simulation toolkit called Poisson Superfish, which is maintained by Los Alamos Natio...

  7. Particle emission in the light heavy-ion fusion reactions: 14N, 16,18O+ 12C

    Science.gov (United States)

    Carlin Filho, N.; Coimbra, M. M.; Acquadro, J. C.; Liguori Neto, R.; Szanto, E. M.; Farrelly-Pessoa, E.; Szanto de Toledo, A.

    1985-01-01

    From the energy spectra of light particles produced in light-heavy-ion-induced reactions, level densities of the final nuclei as well as the critical angular momenta for fusion may be obtained. The 14N, 16,18O+ 12C reactions were investigated in the energy range 30 MeVJcr), offering an alternative method for the total fusion cross-section determination.

  8. Non-invasive red light optogenetic pacing and optical coherence microscopy (OCM) imaging for drosophila melanogaster (Conference Presentation)

    Science.gov (United States)

    Men, Jing; Li, Airong; Jerwick, Jason; Tanzi, Rudolph E.; Zhou, Chao

    2017-02-01

    Cardiac pacing could be a powerful tool for investigating mammalian cardiac electrical conduction systems as well as for treatment of certain cardiac pathologies. However, traditional electrical pacing using pacemaker requires an invasive surgical procedure. Electrical currents from the implanted electrodes can also cause damage to heart tissue, further restricting its utility. Optogenetic pacing has been developed as a promising, non-invasive alternative to electrical stimulation for controlling animal heart rhythms. It induces heart contractions by shining pulsed light on transgene-generated microbial opsins, which in turn activate the light gated ion channels in animal hearts. However, commonly used opsins in optogenetic pacing, such as channelrhodopsin-2 (ChR2), require short light wavelength stimulation (475 nm), which is strongly absorbed and scattered by tissue. Here, we performed optogenetic pacing by expression of recently engineered red-shifted microbial opsins, ReaChR and CsChrimson, in a well-established animal model, Drosophila melanogaster, using the 617 nm stimulation light pulses. The OCM technique enables non-invasive optical imaging of animal hearts with high speed and ultrahigh axial and transverse resolutions. We integrated a customized OCM system with the optical stimulation system to monitor the optogenetic pacing noninvasively. The use of red-sifted opsins enabled deeper penetration of simulating light at lower power, which is promising for applications of optogenetic pacing in mammalian cardiac pathology studies or clinical treatments in the future.

  9. Heavy and light ion irradiation damage effects in δ-phase Sc4Hf3O12

    Science.gov (United States)

    Wen, J.; Li, Y. H.; Tang, M.; Valdez, J. A.; Wang, Y. Q.; Patel, M. K.; Sickafus, K. E.

    2015-12-01

    Polycrystalline δ-phase Sc4Hf3O12 was irradiated with light and heavy ions to study the radiation stability of this compound. In order to explore the ion species spectrum effect, the irradiations were performed with 400 keV Ne2+ ions to fluences ranging from 1 × 1014 to 1 × 1015 ions/cm2, 600 keV Kr3+ ions to fluences ranging from 5 × 1014 to 5 × 1015 ions/cm2, and 6 MeV Xe26+ ions to fluences ranging from 2 × 1013 to 1 × 1015 ions/cm2. Irradiated samples were characterized by various techniques including grazing incidence X-ray diffraction (GIXRD) and transmission electron microscopy (TEM). A complete phase transformation from ordered rhombohedral to disordered fluorite was observed by a fluence of 1 × 1015 ions/cm2 with 400 keV Ne2+ ions, equivalent to a peak ballistic damage dose of ∼0.33 displacements per atom (dpa). Meanwhile, the same transformation was also observed by 600 keV Kr3+ ions at the same fluence of 1 × 1015 ions/cm2, which however corresponds to a peak ballistic damage dose of ∼2.2 dpa. Only a partial O-D transformation was observed for 6 MeV Xe26+ ions in the fluence range used. Experimental results indicated that the O-D transformation is observed under both electronic and nuclear stopping dominant irradiation regimes. It was also observed that light ions are more efficient than heavy ions in producing the retained defects that are presumably responsible for the O-D phase transformation. The O-D transformation mechanism is discussed in the context of anion oxygen Frenkel defects and cation antisite defects. We concluded that the irradiation induced O-D transformation is easier to occur in δ-phase compounds with partial order of cations than in that with fully disordered cation structures.

  10. Lightness of Munker-White illusion and Simultaneous-Contrast illusion: Establishing an ordinal lightness relation among minimum and split-frame presentations

    OpenAIRE

    Li, Ang; Tavantzis, Michael-John; Yazdanbakhsh, Arash

    2009-01-01

    The achromatic Munker-White illusion and the Simultaneous-Contrast illusion have been used extensively in vision studies to understand how the figural configuration of a stimulus can affect the perceived lightness of its components in human perception. Yet, previous modeling and psychophysics studies did not directly compare the illusions’ lightness with controlled parameters of minimum stripes and split-frame presentations, which are useful in testing model predictions and in correlating neu...

  11. Proceedings of the workshop on ion source issues relevant to a pulsed spallation neutron source: Part 2 workshop presentations

    Energy Technology Data Exchange (ETDEWEB)

    Schroeder, L.; Leung, Ka-Ngo; Alonso, J. [eds.

    1994-10-01

    As part of the Lawrence Berkeley Laboratory Pulsed Spallation Source study, this Workshop was convened to address ion-source technology`s present status with respect to the next-generation Pulsed Spallation Source in the 1-5 MW range for the neutron scattering community. Considerations of Low Energy Beam Transport (LEBT) parameters and designs were included in the discussions throughout the Workshop. Ion-source requirements and actually-achieved performances were assessed, resulting in a determination of research and development requirements to bridge the gap. Part 1 of these Proceedings summarizes the Workshop; Part 2 contains viewgraphs of Workshop presentations.

  12. Recent advances in head-mounted light field displays for virtual and augmented reality (Conference Presentation)

    Science.gov (United States)

    Hua, Hong

    2017-02-01

    Head-mounted light field displays render a true 3D scene by sampling either the projections of the 3D scene at different depths or the directions of the light rays apparently emitted by the 3D scene and viewed from different eye positions. They are capable of rendering correct or nearly correct focus cues and addressing the very well-known vergence-accommodation mismatch problem in conventional virtual and augmented reality displays. In this talk, I will focus on reviewing recent advancements of head-mounted light field displays for VR and AR applications. I will demonstrate examples of HMD systems developed in my group.

  13. Present and future sources of protons and heavy ions. [Medical facilities

    Energy Technology Data Exchange (ETDEWEB)

    Grunder, H.A.; Leemann, C.W.

    1976-09-13

    A brief outline of existing medical heavy-ion facilities is given. The beam specifications for future dedicated medical ion accelerators are discussed. Machines capable of delivering dose rates of approximately 1 krad/min in volumes of a few liters are shown to represent existing technology. A cost and performance analysis shows the synchrotrons to be the most economical source for the heavier ions while conventional cyclotrons seem optimal for an exclusive proton facility. It is seen that the incorporation of additional capabilities such as neutron generation or radioisotope production can be achieved at modest incremental costs. In addition to the accelerators, feasible layouts of hypothetical facilities are discussed, and three-dimensional beam scanning is shown to allow the irradiation of large volumes without sacrificing the precise dose localization capabilities of heavy-ion beams. Concepts of quality-controlled engineering and modern computer technology are introduced as a means to obtain the desired high degree of reliability and ease of operation and maintenance.

  14. Present and Near-Future Reflected Light Searches for Close-In Planets

    CERN Document Server

    Charbonneau, D; Charbonneau, David; Noyes, Robert W.

    2000-01-01

    Close-in extrasolar giant planets may be directly detectable by theirreflected light, due to the proximity of the planet to the illuminating star.The spectrum of the system will contain a reflected light component that variesin amplitude and Doppler shift as the planet orbits the star. Intensivesearches for this effect have been carried out for only one extrasolar planetsystem, tau Boo. There exist several other attractive targets, including thetransiting planet system HD 209458.

  15. A rigorous treatment of a follow-the-leader traffic model with traffic lights present

    Energy Technology Data Exchange (ETDEWEB)

    Argall, Brenna; Cheleshkin, Eugene; Greenberg, J.M.; Hinde, Colin; Lin, Pei-Jen

    2003-07-16

    Traffic flow on a unidirectional roadway in the presence of traffic lights is modeled. Individual car responses to green, yellow, and red lights are postulated and these result in rules governing the acceleration and deceleration of individual cars. The essence of the model is that only specific cars are directly affected by the lights. The other cars behave according to simple follow-the-leader rules which limit their speed by the spacing between it and the car directly ahead. The model has a number of desirable properties; namely cars do not run red lights, cars do not smash into one another, and cars exhibit no velocity reversals. In a situation with multiple lights operating in-phase we get, after an initial startup period, a constant number of cars through each light during any green-yellow period. Moreover, this flux is less by one or two cars per period than the flux obtained in discretized versions of the idealized Lighthill, Whitham, Richards model which allows for infinite accelerations.

  16. Shining new light on treating dementia: integrating EEG neurofeedback training and near infrared photobiomodulation (Conference Presentation)

    Science.gov (United States)

    Berman, Marvin H.

    2017-02-01

    Evidence from animal and human studies regarding the biological impact of near infrared light stimulation has significantly increased of late noting the disease modifying properties of photobiomodulation for improving physical and cognitive performance in subjects with a variety of neurodegenerative conditions. Concurrently we see a growing body of literature regarding the efficacy of operant conditioning of EEG amplitude and connectivity in remediating both cognitive and behavioral symptoms of both neuropsychiatric and neurodegenerative disorders including traumatic brain injury, ADHD, PTSD, and dementia. This presentation seeks to outline a treatment model combining these two treatment methods to stop the progression of neurodegeneration using pulsed (10hz), brief (5-20minutes) repeated (1-2x/daily) transcranial and intranasal photobiomodulation with 810nm and 1068nm near infrared phototherapy and operant conditioning of EEG amplitude and coherence. Our initial study on treating dementia with EEG biofeedback (N=37) showed neuroplasticity's potential for modifying cognitive and behavioral symptoms using the evidence from decades of neurological research that never felt the warm touch of a translational researcher's hand. The near infrared interventional studies clarified the order of treatment, i.e., tissue health and renewal were achieved, followed by neural connectivity enhancement. Significant improvements in both immediate and delayed recall and praxis memory as well as executive functioning and behavioral regulation were obtained with each intervention. The inferred synergistic impact of properly combining these approaches is what informs our current clinical applications and future research efforts examining the value of combined treatments for all dementias, parkinson's disease and age-related dry macular degeneration.

  17. Sub-diffuse structured light imaging provides macroscopic maps of microscopic tissue structure (Conference Presentation)

    Science.gov (United States)

    Kanick, Stephen C.

    2016-03-01

    The onset and progression of cancer introduces changes to the intra-cellular ultrastructural components and to the morphology of the extracellular matrix. While previous work has shown that localized scatter imaging is sensitive to pathology-induced differences in these aspects of tissue microstructure, wide adaptation this knowledge for surgical guidance is limited by two factors. First, the time required to image with confocal-level localization of the remission signal can be substantial. Second, localized (i.e. sub-diffuse) scatter remission intensity is influenced interchangeably by parameters that define scattering frequency and anisotropy. This similarity relationship must be carefully considered in order to obtain unique estimates of biomarkers that define either the scatter density or features that describe the distribution (e.g. shape, size, and orientation) of scatterers. This study presents a novel approach that uses structured light imaging to address both of these limitations. Monte Carlo data were used to model the reflectance intensity over a wide range of spatial frequencies, reduced scattering coefficients, absorption coefficients, and a metric of the scattering phase function that directly maps to the fractal dimension of scatter sizes. The approach is validated in tissue-simulating phantoms constructed with user-tuned scattering phase functions. The validation analysis shows that the phase function can be described in the presence of different scatter densities or background absorptions. Preliminary data from clinical tissue specimens show quantitative images of both the scatter density and the tissue fractal dimension for various tissue types and pathologies. These data represent a novel wide-field quantitative approach to mapping microscopic structural biomarkers that cannot be obtained with standard diffuse imaging. Implications for the use of this approach to assess surgical margins will be discussed.

  18. Ion Acceleration by Laser Plasma Interaction from Cryogenic Micro Jets - Oral Presentation

    Energy Technology Data Exchange (ETDEWEB)

    Propp, Adrienne [SLAC National Accelerator Lab., Menlo Park, CA (United States)

    2015-08-25

    Processes that occur in extreme conditions, such as in the center of stars and large planets, can be simulated in the laboratory using facilities such as SLAC National Accelerator Laboratory and the Jupiter Laser Facility (JLF) at Lawrence Livermore National Laboratory (LLNL). These facilities allow scientists to investigate the properties of matter by observing their interactions with high power lasers. Ion acceleration from laser plasma interaction is gaining greater attention today due to its widespread potential applications, including proton beam cancer therapy and fast ignition for energy production. Typically, ion acceleration is achieved by focusing a high power laser on thin foil targets through a mechanism called Target Normal Sheath Acceleration. Based on research and recent experiments, we hypothesized that a pure liquid cryogenic jet would be an ideal target for this type of interaction, capable of producing the highest proton energies possible with today’s laser technologies. Furthermore, it would provide a continuous, pure target, unlike metal foils which are consumed in the interaction and easily contaminated. In an effort to test this hypothesis and investigate new, potentially more efficient mechanisms of ion acceleration, we used the 527 nm split beam, frequency-doubled TITAN laser at JLF. Data from the cryogenic jets was limited due to the flow of current up the jet into the nozzle during the interaction, heating the jet and damaging the orifice. However, we acheived a pure proton beam with an indiciation of a monoenergetic feature. Furthermore, data from gold and carbon wires showed surprising and interesting results. Preliminary analysis of data from two ion emission diagnostics, Thomson parabola spectrometers (TPs) and radio chromic films (RCFs), suggests that shockwave acceleration occurred rather than target normal sheath acceleration, the standard mechanism of ion acceleration. Upon completion of the experiment at TITAN, I researched the

  19. Particle and light fragment emission in peripheral heavy ion collisions at Fermi energies

    Science.gov (United States)

    Piantelli, S.; Maurenzig, P. R.; Olmi, A.; Bardelli, L.; Bartoli, A.; Bini, M.; Casini, G.; Coppi, C.; Mangiarotti, A.; Pasquali, G.; Poggi, G.; Stefanini, A. A.; Taccetti, N.; Vanzi, E.

    2006-09-01

    A systematic investigation of the average multiplicities of light charged particles and intermediate mass fragments emitted in peripheral and semiperipheral collisions is presented as a function of the beam energy, violence of the collision, and mass of the system. The data have been collected with the FIASCO setup in the reactions Nb93+Nb93 at (17,23,30,38)A MeV and Sn116+Sn116 at (30,38)A MeV. The midvelocity emission has been separated from the emission of the projectile-like fragment. This last component appears to be compatible with an evaporation from an equilibrated source at normal density, as described by the statistical code GEMINI at the appropriate excitation energy. On the contrary, the midvelocity emission presents remarkable differences in both the dependence of the multiplicities on the energy deposited in the midvelocity region and the isotopic composition of the emitted light charged particles.

  20. Particle and light fragment emission in peripheral heavy ion collisions at Fermi energies

    CERN Document Server

    Piantelli, S; Olmi, A; Bardelli, L; Bartoli, A; Bini, M; Casini, G; Coppi, C; Mangiarotti, A; Pasquali, G; Poggi, G; Stefanini, A A; Taccetti, N; Vanzi, E

    2006-01-01

    A systematic investigation of the average multiplicities of light charged particles and intermediate mass fragments emitted in peripheral and semiperipheral collisions is presented as a function of the beam energy, violence of the collision and mass of the system. The data have been collected with the "Fiasco" setup in the reactions 93Nb+93Nb at 17, 23, 30, 38AMeV and 116Sn+116Sn at 30, 38AMeV. The midvelocity emission has been separated from the emission of the projectile-like fragment. This last component appears to be compatible with an evaporation from an equilibrated source at normal density, as described by the statistical code Gemini at the appropriate excitation energy. On the contrary, the midvelocity emission presents remarkable differences for what concerns both the dependence of the multiplicities on the energy deposited in the midvelocity region and the isotopic composition of the emitted light charged particles.

  1. Synthesis of crystalline gels on a light-induced polymerization 3D printer (Conference Presentation)

    Science.gov (United States)

    Gong, Jin; Mao, Yuchen; Miyazaki, Takuya; Zhu, Meifang

    2017-04-01

    3D printing, also knows as Additive Manufacturing (AM), was first commercialized in 1986, and has been growing at breakneck speed since 2009 when Stratasys' key patent expired. Currently the 3D printing machines coming on the market can be broadly classified into three categories from the material state point of view: plastic filament printers, powder (or pellet) printers, film printers and liquid photopolymer printers. Much of the work in our laboratory revolves around the crystalline gels. We have succeeded in developing them with high toughness, high flexibility, particularly with many functions as shape memory, energy storage, freshness-retaining, water-absorbing, etc. These crystalline gels are synthesized by light-induced radical polymerization that involves light-reactive monomer having the property of curing with light of a sufficient energy to drive the reaction from liquid to solid. Note that the light-induced polymerized 3D printing uses the same principle. To open up the possibilities for broader application of our crystalline functional gels, we are interested in making them available for 3D printing. In this paper, we share the results of our latest research on the 3D printing of crystalline gels on light-induced 3D printers.

  2. Photonic hypercrystals: new media for control of light-matter interaction (Conference Presentation)

    Science.gov (United States)

    Galfsky, Tal; Narimanov, Evgenii E.; Menon, Vinod M.

    2016-09-01

    Photonic crystals and metamaterials have emerged as the most widely used artificial media for controlling light-matter interaction in solid state systems. The former relies on Bragg scattering from wavelength sized periodic modulation in the dielectric environment while the latter has sub-wavelength sized sub-structures that are designed to give an effective medium response. Here we report a new class of artificial photonic media: "photonics hypercrystals" for control of light matter interaction. Hypercrystals are distinct from photonic crystals, as both material scales involved - the hypercrystal period and the unit cells of its material components - are sub-wavelength. And they are also not metamaterials, as their electromagnetic response is qualitatively different from the expected averaged behavior. This fundamental difference results in a number of nontrivial electromagnetic properties of the hypercrystals, that can be observed in experiment and even lead to practical devices - from broadband enhancement of spontaneous emission and light out-coupling which has never to date been demonstrated simultaneously in either metamaterials or photonic crystals, to Dirac physics and singularities in sub-wavelength sized lattice. Specifically, we demonstrate enhanced spontaneous emission rate (x20) and light out-coupling (x100) from a two-dimensional metal-dielectric hypercrystal embedded with quantum dots. Such designer photonic media with complete control over the optical properties provide a new platform for broadband control of light-matter interaction.

  3. Enhanced light extraction efficiency of chip-on board light-emitting diodes through micro-lens array fabricated by ion wind

    Science.gov (United States)

    Chu, Jingcao; Lei, Xiang; Wu, Jiading; Peng, Yang; Liu, Sheng; Yang, Qian; Zheng, Huai

    2017-03-01

    Low light extraction efficiency (LEE) is a key challenge of chip-on board (COB) packaging light-emitting diodes (LEDs). In this paper, a facile preparation of micro-lens array was proposed based on the ion wind patterning. The geometries and sizes of the micro-lens arrays were controlled through adjusting the voltage parameter of the ion wind generation. Consequently, the micro-lens array with the diameter of 180 μm and the gap distance of 15 μm has been fabricated. Benefitting from this micro-lens array, the LEE of COB packaging LEDs was enhanced by 9%. This facile fabrication of micro-lens array would be a promising method to improve the LEE of COB packaging LEDs.

  4. Development of niobium spoke cavities for a superconducting light-ion linac

    Energy Technology Data Exchange (ETDEWEB)

    Shepard, K W; Kedzie, M; Delayen, J R; Piller, C

    1998-08-01

    This paper reports the development of 350 MHz niobium superconducting cavities for the velocity range 0.2 < v/c < 0.6. Such cavities could be used to form a linac of exceptional flexibility, capable of efficiently accelerating beams of either protons, deuterons, or any of a wide range of ions, at intensities sufficient for a production beam for a radioactive facility. Results of numerical modeling for several resonator geometries are presented. The design and construction status of prototype niobium cavities is discussed.

  5. Magic wavelengths of Ca+ ion for linearly and circularly polarized light

    Science.gov (United States)

    Jiang, Jun; Jiang, Li; Wang, Xia; Shaw, Peter; Zhang, Deng-Hong; Xie, Lu-You; Dong, Chen Zhong

    2017-07-01

    The dynamic dipole polarizabilities of the low-lying states of Ca$^{+}$ for linearly and circularly polarized light are calculated by using relativistic configuration interaction plus core polarization (RCICP) approach. The magic wavelengths, at which the two levels of the transitions have the same ac Stark shifts, for $4s$-$4p_{j,m}$ and $4s$-$3d_{j,m}$ magnetic sublevels transitions are determined. The present magic wavelengths for linearly polarized light agree with the available results excellently. The polarizability for the circularly polarized light has the scalar, vector and tensor components. The dynamic polarizability is different for each of magnetic sublevels of the atomic state. Additional magic wavelengths have been found for the circularly polarized light. We recommend that the measurement of the magic wavelength near 850 nm for $4s-4p_{\\frac32,m=\\pm\\frac32,\\pm\\frac12}$ could be able to determine the oscillator strength ratio of $f_{4p_{\\frac32} \\to 3d_{\\frac32}}$ and $f_{4p_{\\frac32} \\to 3d_{\\frac52}}$.

  6. Rare earth ion modified TiO2 sols for photocatalysis application under visible light excitation

    Institute of Scientific and Technical Information of China (English)

    XIE Yibing; YUAN Chunwei

    2004-01-01

    TiO2 sols modified by rare earth (RE) ions (Ce4+, Eu3+, or Nd3+) were prepared by coprecipitation-peptization method. The photocatalysis activity was studied by investigating the photodegradation effects of active brilliant red dye X-3B. It is found that TiO2 sols modified by Ce4+, Eu3+, or Nd3+ have the anatase crystalline structure, which are prepared at 70°C. All REn+-TiO2 sol samples have uniform nanoparticles with similar morphology, which are homogenously distributed in aqueous colloidal systems. The particle sizes are 10, 8, and 12 nm for Nd3+-TiO2, Eu3+-TiO2, and Ce4+-TiO2, respectively.The character of ultrafine and positive charge sol particles contributes to the good adsorption of X-3B dye molecule on the surface of titania (about 30% X-3B adsorption amount). Experimental results exhibit that REn+-TiO2 sol photocatalysts have the capability to photodegrade X-3B under visible light irradiation. Nd3+-TiO2 and Eu3+-TiO2 show higher photocatalytic activity than Cea+-TiO2, which is due to the difference of standard redox potential of REn+/RE(n-1)+. REn+-TiO2 sols demonstrate more excellent interfacial adsorption and photodegradation effects to X-3B than P25 TiO2 crystallites. Moreover, the degradation mechanism of X-3B is proposed as dye photosensitization and electron scavenging by rare earth ions.

  7. Predictions for the energy loss of light ions in laser-generated plasmas at low and medium velocities.

    Science.gov (United States)

    Cayzac, W; Bagnoud, V; Basko, M M; Blažević, A; Frank, A; Gericke, D O; Hallo, L; Malka, G; Ortner, A; Tauschwitz, An; Vorberger, J; Roth, M

    2015-11-01

    The energy loss of light ions in dense plasmas is investigated with special focus on low to medium projectile energies, i.e., at velocities where the maximum of the stopping power occurs. In this region, exceptionally large theoretical uncertainties remain and no conclusive experimental data are available. We perform simulations of beam-plasma configurations well suited for an experimental test of ion energy loss in highly ionized, laser-generated carbon plasmas. The plasma parameters are extracted from two-dimensional hydrodynamic simulations, and a Monte Carlo calculation of the charge-state distribution of the projectile ion beam determines the dynamics of the ion charge state over the whole plasma profile. We show that the discrepancies in the energy loss predicted by different theoretical models are as high as 20-30%, making these theories well distinguishable in suitable experiments.

  8. Researching Classroom Interaction in the light of social justice. : [paper presentation

    NARCIS (Netherlands)

    Montesano-Montessori, Nicolina; Ponte, Petra

    2010-01-01

    A research into classroom interaction (behaviour and communication) between teachers and pupils in the light of social justice. The research is based on the concern that educational praxis, defined as 'practice which implies a conscious awareness of the practitioners that their actions are morally c

  9. A large-scale NEMS light-emitting array based on CVD graphene (Conference Presentation)

    Science.gov (United States)

    Kim, Hyungsik; Kim, Young Duck; Lee, Changhyuk; Lee, Sunwoo; Seo, Dong-jea; Jerng, Sahng-Kyoon; Chun, Seung-Hyun; Hone, James; Shepard, Kenneth L.

    2017-02-01

    Graphene has received much interest from optical communities largely owing to its photon-like linear energy band structure called Dirac cone. While majority of the recent research has dealt with plasmon and polariton of the two-dimensional material, a recently reported graphene light emitter could render a new dimension of applications, particularly in high-speed optical communication. Moreover chemical vapor deposition (CVD) growth technique for graphene is available today providing means for scalable high quality graphene. The reported graphene emitter provides broadband light emission from visible to mid-infrared which could be instrumental in multi-color display units and optical communications, however a truly large scale implementation has not previously been achieved. Here we demonstrate a CMOS-compatible 262,144 light-emitting pixels array (10 x 10 mm2) based on suspended CVD graphene nano-electro-mechanical systems (GNEMS). A single photoemission area is 19.6 µm2 and a unit pixel is consisting of 512 photoemission devices (16 x 16) where a multiplexer and a digital to analog converter (DAC) are used to control each pixel. This work clearly demonstrates scalability of multi-channel GNEMS light-emitting array, an atomically thin electro-optical module, and further paves a path for its commercial implementation transparent display or high-speed optical communication.

  10. Present status of coupled-channels calculations for heavy-ion subbarrier fusion reactions

    CERN Document Server

    Hagino, K

    2015-01-01

    The coupled-channels method has been a standard tool in analyzing heavy-ion fusion reactions at energies around the Coulomb barrier. We investigate three simplifications usually adopted in the coupled-channels calculations. These are i) the exclusion of non-collective excitations, ii) the assumption of coordinate independent coupling strengths, and iii) the harmonic oscillator approximation for multi-phonon excitations. In connection to the last point, we propose a novel microscopic method based on the beyond-mean-field approach in order to take into account the anharmonic effects of collective vibrations.

  11. Integrated ion sensor device applications based on printed hybrid material systems (Conference Presentation)

    Science.gov (United States)

    List-Kratochvil, Emil J. W.

    2016-09-01

    Comfortable, wearable sensors and computers will enhance every person's awareness of his or her health condition, environment, chemical pollutants, potential hazards, and information of interest. In agriculture and in the food industry there is a need for a constant control of the condition and needs of plants, animals, and farm products. Yet many of these applications depend upon the development of novel, cheap devices and sensors that are easy to implement and to integrate. Organic semiconductors as well as several inorganic materials and hybrid material systems have proven to combine a number of intriguing optical and electronic properties with simple processing methods. As it will be reviewed in this contribution, these materials are believed to find their application in printed electronic devices allowing for the development of smart disposable devices in food-, health-, and environmental monitoring, diagnostics and control, possibly integrated into arrays of sensor elements for multi-parameter detection. In this contribution we review past and recent achievements in the field. Followed by a brief introduction, we will focus on two topics being on the agenda recently: a) the use of electrolyte-gated organic field-effect transistor (EGOFET) and ion-selective membrane based sensors for in-situ sensing of ions and biological substances and b) the development of hybrid material based resistive switches and their integration into fully functional, printed hybrid crossbar sensor array structures.

  12. Room temperature strong light-matter coupling in 3D THz meta-atoms (Conference Presentation)

    Science.gov (United States)

    Paulillo, Bruno; Manceau, Jean-Michel; Li, Lianhe; Linfield, Edmund; Colombelli, Raffaele

    2016-04-01

    We demonstrate strong light-matter coupling at room temperature in the terahertz (THz) spectral region using 3D meta-atoms with extremely sub-wavelength volumes. Using an air-bridge fabrication scheme, we have implemented sub-wavelength 3D THz micro-resonators that rely on suspended loop antennas connected to semiconductor-filled patch cavities. We have experimentally shown that they possess the functionalities of lumped LC resonators: their frequency response can be adjusted by independently tuning the inductance associated the antenna element or the capacitance provided by the metal-semiconductor-metal cavity. Moreover, the radiation coupling and efficiency can be engineered acting on the design of the loop antenna, similarly to conventional RF antennas. Here we take advantage of this rich playground in the context of cavity electrodynamics/intersubband polaritonics. In the strong light-matter coupling regime, a cavity and a two-level system exchange energy coherently at a characteristic rate called the vacuum Rabi frequency ΩR which is dominant with respect to all other loss mechanisms involved. The signature, in the frequency domain, is the appearance of a splitting between the bare cavity and material system resonances: the new states are called upper and a lower polariton branches. So far, most experimental demonstrations of strong light-matter interaction between an intersubband transition and a deeply sub-wavelength mode in the THz or mid-infrared ranges rely on wavelength-scale or larger resonators such as photonic crystals, diffractive gratings, dielectric micro-cavities or patch cavities. Lately, planar metamaterials have been used to enhance the light-matter interaction and strongly reduce the interaction volume by engineering the electric and magnetic resonances of the individual subwavelength constituents. In this contribution we provide evidence of strong coupling between a THz intersubband transition and an extremely sub-wavelength mode (≈λ/10

  13. Classification of heavy metal ions present in multi-frequency multi-electrode potable water data using evolutionary algorithm

    Science.gov (United States)

    Karkra, Rashmi; Kumar, Prashant; Bansod, Baban K. S.; Bagchi, Sudeshna; Sharma, Pooja; Krishna, C. Rama

    2016-12-01

    Access to potable water for the common people is one of the most challenging tasks in the present era. Contamination of drinking water has become a serious problem due to various anthropogenic and geogenic events. The paper demonstrates the application of evolutionary algorithms, viz., particle swan optimization and genetic algorithm to 24 water samples containing eight different heavy metal ions (Cd, Cu, Co, Pb, Zn, Ar, Cr and Ni) for the optimal estimation of electrode and frequency to classify the heavy metal ions. The work has been carried out on multi-variate data, viz., single electrode multi-frequency, single frequency multi-electrode and multi-frequency multi-electrode water samples. The electrodes used are platinum, gold, silver nanoparticles and glassy carbon electrodes. Various hazardous metal ions present in the water samples have been optimally classified and validated by the application of Davis Bouldin index. Such studies are useful in the segregation of hazardous heavy metal ions found in water resources, thereby quantifying the degree of water quality.

  14. Molding the spin flow of light in valley photonic crystals (Conference Presentation)

    Science.gov (United States)

    Dong, Jian-Wen; Chen, Xiao-Dong; Zhu, Hanyu; Wang, Yuan; Zhang, Xiang

    2016-09-01

    Metamaterials offer unprecedented opportunity to engineer fundamental band dispersions which enable novel optoelectronic functionalities and devices. Precise control of photonic degrees of freedom can always succeed to manipulate the flow of light. For example, photonic net spin flows such as one-way transports and spin-directional locking have been realized at the boundary of topologically-protected photonic metacrystals. But this is not the only way to achieve net spin flow in solid state systems. Valley degree of freedom may provide a new route to modulate the spin flow in bulk crystals without the assist of boundary. Here, we show the molding of spin flow of light in valley photonic crystals. The coupled valley and spin physics is illustrated analytically. The associated photonic valley Hall effect and unidirectional net spin flow are well demonstrated inside the bulk crystals, instead of the assist of topologically non-triviality. We also show the independent control of valley and topology, resulting in a topologically protected flat edge state. Valley photonic crystals may open up a new route towards the discovery of fundamentally novel states of light and possible revolutionary applications.

  15. Attempts to use pulsed light as an emerging technology for inactivation of mould naturally present on rye

    Directory of Open Access Journals (Sweden)

    NICOLETA ARON MAFTEI

    2011-12-01

    Full Text Available Pulsed light technology was used to inactivate moulds, naturally present on rye. The experiments were performed on samples containing 3.5·104 CFU/g and 4.3·103 CFU/g. Treatments of different duration (5, 10, 15, 20, 30, and 40 pulses at intensity of 0.4 J·cm-2 per pulse were applied and mould inactivation was evaluated. Besides confirming the utilisation of pulsed light as decontamination method for cereals, this work contributes with new information regarding the effects of the spectral range of pulsed light, proving that the whole UV range of the spectrum accounts for the lethal effect against moulds. This research supports pulsed light as emerging technology in food preservation.

  16. Light and electron microscopic evaluation of hydrogen ion-induced brain necrosis.

    Science.gov (United States)

    Petito, C K; Kraig, R P; Pulsinelli, W A

    1987-10-01

    Excessive accumulation of hydrogen ions in the brain may play a pivotal role in initiating the necrosis seen in infarction and following hyperglycemic augmentation of ischemic brain damage. To examine possible mechanisms involved in hydrogen ion-induced necrosis, sequential structural changes in rat brain were examined following intracortical injection of sodium lactate solution (pH 4.5), as compared with injections at pH 7.3. Following pH 7.3 injection, neuronal swelling developed between 1 and 6 h, but only a needle track wound surrounded by a thin rim of necrotic neurons and vacuolated neuropil was present 24 h after injection. In contrast, pH 4.5 injection produced neuronal necrosis as soon as 1 h after injection, followed by necrosis of astrocytes and intravascular thrombi at 3 and 6 h. Alterations common to both groups included vascular permeability to horseradish peroxidase, dilation of extracellular spaces, astrocyte swelling, capillary compression, and vascular stasis. These data suggest that neurons, astrocytes, and endothelia can be directly damaged by increased acid in the interstitial space. Lethal injury initially appeared to affect neurons, while subsequent astrocyte necrosis and vascular occlusion may damage tissue by secondary ischemia.

  17. Understanding and predicting the orientation of heteroleptic phosphors in organic light-emitting materials (Conference Presentation)

    Science.gov (United States)

    Schmidt, Tobias D.; Jurow, Matthew; Mayr, Christian; Lampe, Thomas; Djurovic, Peter I.; Thompson, Mark E.; Brütting, Wolfgang

    2016-09-01

    Organic light-emitting diodes (OLEDs) have made tremendous progress in recent years. The internal quantum efficiency was continuously improved and is nowadays close to the ideal value of unity in state-of-the-art OLEDs. However, still only a small fraction of the internally generated power can be used for lighting aspects as most of the light is captured inside the device due to low outcoupling factors of typically 25%. One promising approach to increase this limiting factor is using an anisotropic orientation of the dye molecules. In particular, horizontal orientation of transition dipole vectors (TDV) of the emitting species is a powerful tool to improve the efficiency of OLEDs. In order to understand the underlying mechanisms for emitter orientation of heteroleptic phosphors, we compared the anisotropy factor of emissive guest/host systems prepared by thermal evaporation using different Ir-complexes incorporating coumarin and phenylpyridin based ligands. These molecules exhibit similar high permanent dipole moments and electrostatic surface potentials but differ in their molecular structure. Interestingly, only molecules with both aromatic and aliphatic ligands show non-isotropic distributions of their TDVs when co-deposited with a matrix material. From these findings we conclude that molecular orientation of heteroleptic Ir-complexes occurs instantaneously at the surface of the growing film and is driven by chemical interactions with the surrounding media, i.e. the vacuum and the aromatic matrix side. Furthermore, it is possible to predict the anisotropy factor for arbitrary molecular orientation with a mathematical model taking into account the geometrical distribution of the TDV on the molecules.

  18. Lighting

    Data.gov (United States)

    Federal Laboratory Consortium — Lighting Systems Test Facilities aid research that improves the energy efficiency of lighting systems. • Gonio-Photometer: Measures illuminance from each portion of...

  19. Can pneumocephalus present as flashes of light? A rare case report

    Directory of Open Access Journals (Sweden)

    Santanu Ghosh

    2017-01-01

    Full Text Available Orbital emphysema and associated pneumocephalus usually result from trauma to orbital bones or due to sinus disease, allowing air to travel from paranasal sinus into orbit and brain. However, it is extremely rare to have orbital emphysema and pneumocephalus in the absence of orbital wall fracture. In our case, a young male was admitted with severe eye pain, diminution of vision due to sudden exposure of compressed air gun. Examination revealed proptosed, emphysematous right eye with conjunctival laceration. Computed tomography scan of the head and orbit revealed multiple radiolucencies with air in the right orbit and brain extending up to the spinal canal without any evidence of orbital sinus or cranial bone fracture. Visual acuity recovered completely on follow–up; however, 2 weeks following injury, the patient developed disabling flashes of light which the patient perceived as central in location and resolved finally over a period of 3 months. Flashes of light, in our case, could be attributable to unnoticed damage to cerebral vasculature or connective tissue surrounding the optic nerve due to pneumocephalus.

  20. Organic semiconductor heterojunction and its application in organic light-emitting diodes (Conference Presentation)

    Science.gov (United States)

    Ma, Dongge

    2016-09-01

    Organic light-emitting diodes (OLEDs) have drawn increasing attention as the next generation displays and lighting sources. High efficiency and long lifetime are necessary for OLEDs in practical applications. In conventional OLEDs, the charge carriers are directly injected into the organic transport layers from electrodes, the injection barriers between the organic transport layers and electrodes are unavoidable due to the mismatch between the work function of metal electrode and the energy level of charge-transport layer, which greatly affects the performance of fabricated OLEDs. Furthermore, tandem OLEDs, which are fabricated by vertically connecting several individual electroluminescent (EL) units together in series via an appropriate charge generation layer (CGL) with the entire device driven by a single power source can significantly enhance current efficiency and stability, but their performance is strongly dependent on the used CGL, especially the power efficiency is difficult to enhance due to the increase of working voltage. Recently we found that organic semiconductor heterojunctions show efficient charge generation effect and as CGL, not only double the luminance and current efficiency, but also greatly improve the power efficiency, which is difficult in tandem OLEDs based on conventional CGLs. We also realized electrode-independent charge injection by using organic semiconductor heterojuncrions as injectors in OLEDs, and obtained comparable electroluminescent (EL) performance with that of conventional OLEDs. Here, we report the results of tandem OLEDs based on organic semiconductor heterojunctions as CGL and OLEDs using organic semiconductor heterojunctions as injectors, and discuss this working mechanism in detail.

  1. Efficient inverted organic light-emitting devices by amine-based solvent treatment (Presentation Recording)

    Science.gov (United States)

    Song, Myoung Hoon; Choi, Kyoung-Jin; Jung, Eui Dae

    2015-10-01

    The efficiency of inverted polymer light-emitting diodes (iPLEDs) were remarkably enhanced by introducing spontaneously formed ripple-shaped nanostructure of ZnO (ZnO-R) and amine-based polar solvent treatment using 2-methoxyethanol and ethanolamine (2-ME+EA) co-solvents on ZnO-R. The ripple-shape nanostructure of ZnO layer fabricated by solution process with optimal rate of annealing temperature improves the extraction of wave guide modes inside the device structure, and 2-ME+EA interlayer enhances the electron injection and hole blocking and reduces exciton quenching between polar solvent treated ZnO-R and emissive layer. As a result, our optimized iPLEDs show the luminous efficiency (LE) of 61.6 cd A-1, power efficiency (PE) of 19.4 lm W-1 and external quantum efficiency (EQE) of 17.8 %. This method provides a promising method, and opens new possibilities for not only organic light-emitting diodes (OLEDs) but also other organic optoelectronic devices such as organic photovoltaics, organic thin film transistors, and electrically driven organic diode laser.

  2. Selective control of small versus large diameter axons using infrared laser light (Conference Presentation)

    Science.gov (United States)

    Lothet, Emilie H.; Shaw, Kendrick M.; Horn, Charles C.; Lu, Hui; Wang, Yves T.; Jansen, E. Duco; Chiel, Hillel J.; Jenkins, Michael W.

    2016-03-01

    Sensory information is conveyed to the central nervous system via small diameter unmyelinated fibers. In general, smaller diameter axons have slower conduction velocities. Selective control of such fibers could create new clinical treatments for chronic pain, nausea in response to chemo-therapeutic agents, or hypertension. Electrical stimulation can control axonal activity, but induced axonal current is proportional to cross-sectional area, so that large diameter fibers are affected first. Physiologically, however, synaptic inputs generally affect small diameter fibers before large diameter fibers (the size principle). A more physiological modality that first affected small diameter fibers could have fewer side effects (e.g., not recruiting motor axons). A novel mathematical analysis of the cable equation demonstrates that the minimum length along the axon for inducing block scales with the square root of axon diameter. This implies that the minimum length along an axon for inhibition will scale as the square root of axon diameter, so that lower radiant exposures of infrared light will selectively affect small diameter, slower conducting fibers before those of large diameter. This prediction was tested in identified neurons from the marine mollusk Aplysia californica. Radiant exposure to block a neuron with a slower conduction velocity (B43) was consistently lower than that needed to block a faster conduction velocity neuron (B3). Furthermore, in the vagus nerve of the musk shrew, lower radiant exposure blocked slow conducting fibers before blocking faster conducting fibers. Infrared light can selectively control smaller diameter fibers, suggesting many novel clinical treatments.

  3. Coupling of light into the fundamental diffusion mode of a scattering medium (Conference Presentation)

    Science.gov (United States)

    Ojambati, Oluwafemi S.; Yılmaz, Hasan; Lagendijk, Ad; Mosk, Allard P.; Vos, Willem L.

    2016-03-01

    Diffusion equation describes the energy density inside a scattering medium such as biological tissues and paint [1]. The solution of the diffusion equation is a sum over a complete set of eigensolutions that shows a characteristic linear decrease with depth in the medium. It is of particular interest if one could launch energy in the fundamental eigensolution, as this opens the opportunity to achieve a much greater internal energy density. For applications in optics, an enhanced energy density is vital for solid-state lighting, light harvesting in solar cells, low-threshold random lasers, and biomedical optics. Here we demonstrate the first ever selective coupling of optical energy into a diffusion eigensolution of a scattering medium of zinc oxide (ZnO) paint. To this end, we exploit wavefront shaping to selectively couple energy into the fundamental diffusion mode, employing fluorescence of nanoparticles randomly positioned inside the medium as a probe of the energy density. We observe an enhanced fluorescence in case of optimized incident wavefronts, and the enhancement increases with sample thickness, a typical mesoscopic control parameter. We interpret successfully our result by invoking the fundamental eigensolution of the diffusion equation, and we obtain excellent agreement with our observations, even in absence of adjustable parameters [2]. References [1] R. Pierrat, P. Ambichl, S. Gigan, A. Haber, R. Carminati, and R. Rotter, Proc. Natl. Acad. Sci. U.S.A. 111, 17765 (2014). [2] O. S. Ojambati, H. Yilmaz, A. Lagendijk, A. P. Mosk, and W. L. Vos, arXiv:1505.08103.

  4. Perovskite nanocrystals for light-emitting and energy harvesting applications (Conference Presentation)

    Science.gov (United States)

    Urban, Alexander S.; Sichert, Jasmina A.; Tong, Yu; Hintermayr, Verena; Polavarapu, Lakshminarayana; Stolarczyk, Jacek K.; Feldmann, Jochen

    2016-09-01

    We focus on fabricating organic/inorganic halide perovskites with controlled dimensionality, size and composition and studying the optical and electrical properties of the resulting nanocrystals. By partially exchanging the most commonly used organic cation methylammonium for a cation with a larger chain we are able to fabricate two-dimensional nanoplatelets down to a single unit cell thickness.1 Through absorption and photoluminescence measurements we find that this leads to a strong-quantum size effect in the perovskites while additionally increasing the exciton bind energy to several hundreds of meV. We employ several fabrication techniques to increase the fluorescence quantum yield to be able to investigate single particles, and to study energy transport between individual nanocrystals by time-resolved spectroscopic methods. Our findings can lead to improvements in not only photovoltaic devices, but also for light-harvesting and light-emitting devices, such as LEDs and lasers. (1) Sichert, J. A.; Tong, Y.; Mutz, N.; Vollmer, M.; Fischer, S.; Milowska, K. Z.; García Cortadella, R.; Nickel, B.; Cardenas-Daw, C.; Stolarczyk, J. K.; Urban, A. S.; Feldmann, J. Nano Letters 2015, 15, 6521.

  5. White light emission from an exciplex interface with a single emitting layer (Conference Presentation)

    Science.gov (United States)

    Bernal, Wilson; Perez-Gutierrez, Enrique; Agular, Andres; Barbosa G, J. Oracio C.; Maldonado, Jose L.; Meneses-Nava, Marco Antonio; Rodriguez Rivera, Mario A.; Rodriguez, Braulio

    2017-02-01

    Efficient solid state lighting devices based in inorganic emissive materials are now available in the market meanwhile for organic emissive materials still a lot of research work is in its way. [1,2] In this work a new organic emissive material based on carbazole, N-(4-Ethynylphenyl) carba-zole-d4 (6-d4), is used as electron-acceptor and commercial PEDOT:PSS as the electron-donor to obtain white emission. Besides the HOMO-LUMO levels of materials the white emission showed dependence on the films thicknesses and applied voltages. In here it is reported that by diminishing the thickness of the PEDOT:PSS layer, from 60 to 35 nm, and by keeping the derivative carbazole layer constant at 100 nm the electro-luminescence (EL) changed from emissive exciton states to the mixture of emissive exciton and exciplex states. [3] For the former thicknesses no white light was obtained meanwhile for the later the EL spectra broadened due to the emission of exciplex states. Under this condition, the best-achieved CIE coordinate was (0.31,0.33) with a driving voltage of 8 V. To lower the driving voltage of the devices a thin film of LiF was added between the derivative of carbazol and cathode but the CIE coordinates changed. The best CIE coordinates for this case were (0.29, 0.34) and (0.32, 0.37) with driving voltage of about 6.5 V. Acknowledgments: CeMie-Sol/27 (Mexico) 207450 References [1] Timothy L Dawson, Society of Dyers and Colourists, Color. Technol., 126, 1-10 (2010), doi: 10.1111/j.1478-4408.2010.00220.x [2] G. M. Farinola, R. Ragni, Journal of Solid State Lighting, 2:9 (2015), doi: 10.1186/s40539-015-0028-7. [3] E. Angioni, et al, J. Mater. Chem. C, 2016, 4, 3851, doi: 10.1039/c6tc00750c.

  6. Modeling of organic light emitting diodes: from molecular to device properties (Conference Presentation)

    Science.gov (United States)

    Andrienko, Denis; Kordt, Pascal; May, Falk; Badinski, Alexander; Lennartz, Christian

    2016-09-01

    We will review the progress in modeling of charge transport in disordered organic semiconductors on various length-scales, from atomistic to macroscopic. This includes evaluation of charge transfer rates from first principles, parametrization of coarse-grained lattice and off-lattice models, and solving the master and drift-diffusion equations. Special attention is paid to linking the length-scales and improving the efficiency of the methods. All techniques will be illustrated on an amorphous organic semiconductor, DPBIC, a hole conductor and electron blocker used in state of the art organic light emitting diodes (OLEDs). The outlined multiscale scheme can be used to predict OLED properties without fitting parameters, starting from chemical structures of compounds.

  7. Guiding light by plasmonic resonant solitons in metallic nanosuspensions (Presentation Recording)

    Science.gov (United States)

    Kelly, Trevor S.; Samadi, Akbar; Bezryadina, Anna; Chen, Zhigang

    2015-09-01

    In typical colloidal suspensions, the corresponding optical polarizability is positive, and thus enhanced scattering takes place as optical beams tend to catastrophically collapse during propagation. Recently, light penetration deep inside scattering suspensions has been realized by engineering dielectric or plasmonic nanoparticle polarizibilities. In particular, we have previously demonstrated two types of soft-matter systems with tunable optical nonlinearities - the dielectric and metallic colloidal suspensions, in which the effects of diffraction and scattering were overcome, hence achieving deep penetration of a light needle through the suspension. In this work, we show that waveguides can be established in soft matter systems such as metallic nanosuspensions through the formation of plasmonic resonant solitons. First, we show that, due to plasmonic resonance, a 1064nm laser beam (probe) would not experience appreciable nonlinear self-action while propagating through 4cm cuvette containing the metallic nanosuspension of gold spheres (40nm), whereas a 532nm laser beam (pump) can readily form a spatial soliton due to nonlinear self-trapping. Second, we demonstrate effective guidance of the probe beam, which would otherwise diffract significantly through the nanosuspensions, due to the soliton-induced waveguide from the pump beam. Such guidance was observed when the power of the probe beam was varied from 20mW to 500mW at constant pump beam power, with more pronounced guidance realized from lower to higher probe beam power. Interestingly, due to the presence of the probe beam, the pump beam undergoes self-trapping at an even lower power. These results may bring about the possibility of engineering plasmonic soliton-based waveguides for many applications.

  8. Optical mapping of conduction in early embryonic quail hearts with light-sheet microscopy (Conference Presentation)

    Science.gov (United States)

    Ma, Pei; Gu, Shi; Wang, Yves T.; Jenkins, Michael W.; Rollins, Andrew M.

    2016-03-01

    Optical mapping (OM) using fluorescent voltage-sensitive dyes (VSD) to measure membrane potential is currently the most effective method for electrophysiology studies in early embryonic hearts due to its noninvasiveness and large field-of-view. Conventional OM acquires bright-field images, collecting signals that are integrated in depth and projected onto a 2D plane, not capturing the 3D structure of the sample. Early embryonic hearts, especially at looping stages, have a complicated, tubular geometry. Therefore, conventional OM cannot provide a full picture of the electrical conduction circumferentially around the heart, and may result in incomplete and inaccurate measurements. Here, we demonstrate OM of Hamburger and Hamilton stage 14 embryonic quail hearts using a new commercially-available VSD, Fluovolt, and depth sectioning using a custom built light-sheet microscopy system. Axial and lateral resolution of the system is 14µm and 8µm respectively. For OM imaging, the field-of-view was set to 900µm×900µm to cover the entire heart. 2D over time OM image sets at multiple cross-sections through the looping-stage heart were recorded. The shapes of both atrial and ventricular action potentials acquired were consistent with previous reports using conventional VSD (di-4-ANNEPS). With Fluovolt, signal-to-noise ratio (SNR) is improved significantly by a factor of 2-10 (compared with di-4-ANNEPS) enabling light-sheet OM, which intrinsically has lower SNR due to smaller sampling volumes. Electrophysiologic parameters are rate dependent. Optical pacing was successfully integrated into the system to ensure heart rate consistency. This will also enable accurately gated reconstruction of full four dimensional conduction maps and 3D conduction velocity measurements.

  9. Challenges Considering the Degradation of Cell Components in Commercial Lithium-Ion Cells: A Review and Evaluation of Present Systems.

    Science.gov (United States)

    Kleiner, Karin; Ehrenberg, Helmut

    2017-06-01

    individual cell components. Although the degradation of materials is the key consideration in achieving lower costs, a higher safety standard, higher energy densities and a longer lifetime, the degradation of the individual cell components in dependence on the operation conditions has hardly been investigated and is poorly understood. The present work reviews known material degradations in commercial lithium-ion cells, shows a way to analyze such degradations in dependence on the operation conditions and describes how these degradation processes lead to observed performance drops.

  10. Enhanced Visible Light Photocatalytic Activity of ZnO Nanowires Doped with Mn2+ and Co2+ Ions

    Science.gov (United States)

    Li, Wei; Wang, Guojing; Chen, Chienhua; Liao, Jiecui; Li, Zhengcao

    2017-01-01

    In this research, ZnO nanowires doped with Mn2+ and Co2+ ions were synthesized through a facile and inexpensive hydrothermal approach, in which Mn2+ and Co2+ ions successfully substituted Zn2+ in the ZnO crystal lattice without changing the morphology and crystalline structure of ZnO. The atomic percentages of Mn and Co were 6.29% and 1.68%, respectively, in the doped ZnO nanowires. The photocatalytic results showed that Mn-doped and Co-doped ZnO nanowires both exhibited higher photocatalytic activities than undoped ZnO nanowires. Among the doped ZnO nanowires, Co-doped ZnO, which owns a twice active visible-light photocatalytic performance compared to pure ZnO, is considered a more efficient photocatalyst material. The enhancement of its photocatalytic performance originates from the doped metal ions, which enhance the light absorption ability and inhibit the recombination of photo-generated electron-hole pairs as well. The effect of the doped ion types on the morphology, crystal lattice and other properties of ZnO was also investigated.

  11. Enhanced Visible Light Photocatalytic Activity of ZnO Nanowires Doped with Mn2+ and Co2+ Ions

    Directory of Open Access Journals (Sweden)

    Wei Li

    2017-01-01

    Full Text Available In this research, ZnO nanowires doped with Mn2+ and Co2+ ions were synthesized through a facile and inexpensive hydrothermal approach, in which Mn2+ and Co2+ ions successfully substituted Zn2+ in the ZnO crystal lattice without changing the morphology and crystalline structure of ZnO. The atomic percentages of Mn and Co were 6.29% and 1.68%, respectively, in the doped ZnO nanowires. The photocatalytic results showed that Mn-doped and Co-doped ZnO nanowires both exhibited higher photocatalytic activities than undoped ZnO nanowires. Among the doped ZnO nanowires, Co-doped ZnO, which owns a twice active visible-light photocatalytic performance compared to pure ZnO, is considered a more efficient photocatalyst material. The enhancement of its photocatalytic performance originates from the doped metal ions, which enhance the light absorption ability and inhibit the recombination of photo-generated electron-hole pairs as well. The effect of the doped ion types on the morphology, crystal lattice and other properties of ZnO was also investigated.

  12. Attempts to use pulsed light as an emerging technology for inactivation of mould naturally present on rye

    OpenAIRE

    NICOLETA ARON MAFTEI; ANA RAMOS-VILLARROEL; ANCA NICOLAU; OLGA MARTIN-BELLOSO

    2011-01-01

    Pulsed light technology was used to inactivate moulds, naturally present on rye. The experiments were performed on samples containing 3.5·104 CFU/g and 4.3·103 CFU/g. Treatments of different duration (5, 10, 15, 20, 30, and 40 pulses) at intensity of 0.4 J·cm-2 per pulse were applied and mould inactivation was evaluated. Besides confirming the utilisation of pulsed light as decontamination method for cereals, this work contributes with new information regarding the effects of the spectral ran...

  13. Full solution process approach for deterministic control of light emission at the nanoscale (Conference Presentation)

    Science.gov (United States)

    Jiménez-Solano, Alberto; Galisteo-López, Juan F.; Míguez, Hernán.

    2016-04-01

    Porous nanostructured photonic materials in the shape of periodic multilayers have demonstrated their potential in different fields ranging from photovoltaics[1] to sensing,[2] representing an ideal platform for flexible devices. When applications dealing with light absorption or emission are considered, knowledge on how the local density of states (LDOS) is distributed within them is mandatory[3] in order to realize a judicious design which maximizes light matter interaction. Using a combination of spin and dip-casting we report a detail study of how dye doped polystyrene nanospheres constitute an effective LDOS probe to study its distribution within nanostructured photonic media.[4] This full solution process approach allows to cover large areas keeping the photonics properties. Nanospheres with a diameter of 25 nm are incorporated in nanostructured multilayers (Fig. 1a).. This allows to place them at several positions of the structured sample (Fig. 1b). A combined use of photoluminescence spectroscopy and time resolved measurements are used to optically characterize the samples. While the former shows how depending on the probe position its PL intensity can be enhanced or suppressed, the latter allows to probe the LDOS changes within the sample, monitored via changes in its lifetime. We demonstrate how information on the local photonic environment can be retrieved with a spatial resolution of 25 nm (provided by the probe size) and relative changes in the decay rates as small as ca. 1% (Fig. 1c), evidencing the possibility of exerting a fine deterministic control on the photonic surroundings of an emitter. References [1] C. López-López, S. Colodrero, M. E. Calvo and H. Míguez, Energy Environ. Sci., 23, 2805 (2013). [2] A. Jiménez-Solano, C. López-López, O. Sánchez-Sobrado, J. M. Luque, M. E. Calvo, C. Fernández-López, A. Sánchez-Iglesias, L. M. Liz-Marzán and H. Míguez. Langmuir, 28, 9161 (2012). [3] N. Danz, R. Waldhäusl, A. Bräuer and R

  14. Light-matter interaction: conversion of the optical energy and momentum to mechanical vibrations and phonons (Conference Presentation)

    Science.gov (United States)

    Mansuripur, Masud

    2016-09-01

    Interactions between light and material media generally involve an exchange of energy and momentum. Whereas packets of electromagnetic radiation (i.e., photons) are known to carry energy as well as momentum, the eigen-modes of mechanical vibration (i.e., phonons) do not carry any momentum of their own. Considering that, in light-matter interactions, not only the total energy but also the total momentum (i.e., electromagnetic plus mechanical momentum) must be conserved, it becomes necessary to examine the momentum exchange mechanism in some detail. In this presentation, we describe the intricate means by which mechanical momentum is taken up and carried away by material media during reflection, refraction, and absorption of light pulses, thereby ensuring the conservation of linear momentum. Particular attention will be paid to periodically-structured media, which are capable of supporting acoustic as well as optical phonons.

  15. Gradient light interference microscopy (GLIM) for imaging thick specimens (Conference Presentation)

    Science.gov (United States)

    Nguyen, Tan H.; Kandel, Mikhail E.; Popescu, Gabriel

    2016-03-01

    Compared to the Phase Contrast, Differential Interference Contrast (DIC) has been known to give higher depth sectioning as well as a halo-free images when investigating transparent specimens. Thanks to relying on generating two slightly shifted replicas with a small amount of shift, within the coherence area, DIC is able to operate with very low coherence light. More importantly, the method is able to work with very large numerical aperture of the illumination, which offer comparable sectioning capability to bright field microscopy. However, DIC is still a qualitative method, which limits potential applications of the technique. In this paper, we introduce a method that extends the capability of DIC by combining it with a phase shifting module to extract the phase gradient information. A theoretical model of the image formation is developed and the possibility of integrating the gradient function is analyzed.. Our method is benchmarked on imaging embryos during their 7-day development, HeLa cells during mitosis, and control samples.

  16. Visible light optical coherence tomography measure retinal oxygen metabolic response to systemic oxygenation (Conference Presentation)

    Science.gov (United States)

    Yi, Ji; Liu, Wenzhong; Chen, Siyu; Backman, Vadim; Sheibani, Nader; Sorenson, Christine M.; Fawzi, Amani A.; Linsenmeier, Robert A.; Zhang, Hao F.

    2016-03-01

    The lack of capability to quantify oxygen metabolism noninvasively impedes both fundamental investigation and clinical diagnosis of a wide spectrum of diseases including all the major blinding diseases such as age-related macular degeneration, diabetic retinopathy, and glaucoma. Using visible light optical coherence tomography (vis-OCT), we demonstrated accurate and robust measurement of retinal oxygen metabolic rate (rMRO2) noninvasively in rat eyes. The rMRO2 was calculated by concurrent measurement of blood flow and blood oxygen saturation (sO2). Blood flow was calculated by the principle of Doppler optical coherence tomography, where the phase shift between two closely spaced A-lines measures the axial velocity. The distinct optical absorption spectra of oxy- and deoxy-hemoglobin provided the contrast for sO2 measurement, combined with the spectroscopic analysis of vis-OCT signal within the blood vessels. We continuously monitored the regulatory response of oxygen consumption to a progressive hypoxic challenge. We found that both oxygen delivery, and rMRO2 increased from the highly regulated retinal circulation (RC) under hypoxia, by 0.28+/-0.08 μL/min (pcompensated for the deficient oxygen supply from the poorly regulated choroidal circulation (CC).

  17. Lung gene therapy-How to capture illumination from the light already present in the tunnel.

    Science.gov (United States)

    Xia, Emily; Munegowda, Manjunatha Ankathatti; Cao, Huibi; Hu, Jim

    2014-09-01

    Gene therapy has been considered as the most ideal medical intervention for genetic diseases because it is intended to target the cause of diseases instead of disease symptoms. Availability of techniques for identification of genetic mutations and for in vitro manipulation of genes makes it practical and attractive. After the initial hype in 1990s and later disappointments in clinical trials for more than a decade, light has finally come into the tunnel in recent years, especially in the field of eye gene therapy where it has taken big strides. Clinical trials in gene therapy for retinal degenerative diseases such as Leber's congenital amaurosis (LCA) and choroideremia demonstrated clear therapeutic efficacies without apparent side effects. Although these successful examples are still rare and sporadic in the field, they provide the proof of concept for harnessing the power of gene therapy to treat genetic diseases and to modernize our medication. In addition, those success stories illuminate the path for the development of gene therapy treating other genetic diseases. Because of the differences in target organs and cells, distinct barriers to gene delivery exist in gene therapy for each genetic disease. It is not feasible for authors to review the current development in the entire field. Thus, in this article, we will focus on what we can learn from the current success in gene therapy for retinal degenerative diseases to speed up the gene therapy development for lung diseases, such as cystic fibrosis.

  18. Virtual 3D bladder reconstruction for augmented medical records from white light cystoscopy (Conference Presentation)

    Science.gov (United States)

    Lurie, Kristen L.; Zlatev, Dimitar V.; Angst, Roland; Liao, Joseph C.; Ellerbee, Audrey K.

    2016-02-01

    Bladder cancer has a high recurrence rate that necessitates lifelong surveillance to detect mucosal lesions. Examination with white light cystoscopy (WLC), the standard of care, is inherently subjective and data storage limited to clinical notes, diagrams, and still images. A visual history of the bladder wall can enhance clinical and surgical management. To address this clinical need, we developed a tool to transform in vivo WLC videos into virtual 3-dimensional (3D) bladder models using advanced computer vision techniques. WLC videos from rigid cystoscopies (1280 x 720 pixels) were recorded at 30 Hz followed by immediate camera calibration to control for image distortions. Video data were fed into an automated structure-from-motion algorithm that generated a 3D point cloud followed by a 3D mesh to approximate the bladder surface. The highest quality cystoscopic images were projected onto the approximated bladder surface to generate a virtual 3D bladder reconstruction. In intraoperative WLC videos from 36 patients undergoing transurethral resection of suspected bladder tumors, optimal reconstruction was achieved from frames depicting well-focused vasculature, when the bladder was maintained at constant volume with minimal debris, and when regions of the bladder wall were imaged multiple times. A significant innovation of this work is the ability to perform the reconstruction using video from a clinical procedure collected with standard equipment, thereby facilitating rapid clinical translation, application to other forms of endoscopy and new opportunities for longitudinal studies of cancer recurrence.

  19. The Unio Mystica of Teresa of Avila: two classical presentations in the light of psychology

    Directory of Open Access Journals (Sweden)

    Hans Åkerberg

    1982-01-01

    Full Text Available It is generally maintained within the Carmelite tradition that Teresa (1515-1582 showed an extraordinary facility in describing the stages of mysticism with experimential vigour and deep intensity, compared for example to John of the Cross, whose mystical presentation is of a more dogmatic and systematic nature. In this sense she would appear to be unsurpassed within the entire Roman Catholic mystic tradition. The author compares two classical presentations by Teresa of the significance of unio mystica, firstly her description of this in the Libro de la vida, and secondly her presentation of the same mystic element in the book Castillo interior o Las moradas.

  20. Accelerator mass spectrometry detection of beryllium ions in the antigen processing and presentation pathway.

    Science.gov (United States)

    Tooker, Brian C; Brindley, Stephen M; Chiarappa-Zucca, Marina L; Turteltaub, Kenneth W; Newman, Lee S

    2015-01-01

    Exposure to small amounts of beryllium (Be) can result in beryllium sensitization and progression to Chronic Beryllium Disease (CBD). In CBD, beryllium is presented to Be-responsive T-cells by professional antigen-presenting cells (APC). This presentation drives T-cell proliferation and pro-inflammatory cytokine (IL-2, TNFα, and IFNγ) production and leads to granuloma formation. The mechanism by which beryllium enters an APC and is processed to become part of the beryllium antigen complex has not yet been elucidated. Developing techniques for beryllium detection with enough sensitivity has presented a barrier to further investigation. The objective of this study was to demonstrate that Accelerator Mass Spectrometry (AMS) is sensitive enough to quantify the amount of beryllium presented by APC to stimulate Be-responsive T-cells. To achieve this goal, APC - which may or may not stimulate Be-responsive T-cells - were cultured with Be-ferritin. Then, by utilizing AMS, the amount of beryllium processed for presentation was determined. Further, IFNγ intracellular cytokine assays were performed to demonstrate that Be-ferritin (at levels used in the experiments) could stimulate Be-responsive T-cells when presented by an APC of the correct HLA type (HLA-DP0201). The results indicated that Be-responsive T-cells expressed IFNγ only when APC with the correct HLA type were able to process Be for presentation. Utilizing AMS, it was determined that APC with HLA-DP0201 had membrane fractions containing 0.17-0.59 ng Be and APC with HLA-DP0401 had membrane fractions bearing 0.40-0.45 ng Be. However, HLA-DP0401 APC had 20-times more Be associated with the whole cells (57.68-61.12 ng) than HLA-DP0201 APC (0.90-3.49 ng). As these findings demonstrate, AMS detection of picogram levels of Be processed by APC is possible. Further, regardless of form, Be requires processing by APC to successfully stimulate Be-responsive T-cells to generate IFNγ.

  1. Controlling light emission performance with hybrid phase-change plasmonic crystals (Conference Presentation)

    Science.gov (United States)

    Kao, Tsung Sheng

    2016-09-01

    In this paper, we demonstrate a novel approach in which the lattice resonances are tunable in a hybrid plasmonic crystal incorporating the phase-change material Ge2Sb2Te5 (GST) as a 20-nm-thick layer sandwiched between a gold nanodisk array and a quartz substrate. Non-volatile tuning of lattice resonances over a range Δλ of about 500 nm is achieved experimentally via intermediate phase states of the GST layer. This work demonstrates the efficacy and ease of resonance tuning via GST in the near infrared, suggesting the possibility to design broadband non-volatile tunable devices for optical modulation, switching, sensing and nonlinear optical devices. Also, with different nanostructure designs, the constituent plasmonic resonators can be selectively excited, generating isolated near-field energy hot-spots with selective excitation under a monochromatic plane wave illumination. Unlike other proposed techniques, our method for energy hot-spot positioning is based on a quantitative control of the crystalline proportions of the phase-change thin film rather than the complicated manipulations of an incident light beam. This makes such a near-field energy controllable template much easier to be implemented. This near-field energy controllable system consists of gold nano-antennas with deep subwavelength spacing and an underlying GST thin layer. Such a hybrid plasmonic system is easy to be implemented and the nanoscale energy hot-spot can be positioned in a large field of view by extending the system with different plasmon resonators, suggesting a further step toward applications such as nano-imaging, bio-assay addressing and nano-circuitry.

  2. Visible light optical coherence tomography for microvascular oximetry in ocular circulation (Conference Presentation)

    Science.gov (United States)

    Chen, Siyu; Yi, Ji; Zhang, Hao F.

    2016-03-01

    Visible light optical coherence tomography (vis-OCT) is intrinsically capable of optical determination of blood oxygen saturation (sO2). Thanks to its 3D sectioning ability, confounding factors that plaque multi-wavelength fundus photography can be avoided. We further supplemented it with motion-enhanced angiography (vis-OCTA), which allowed us to resolve retinal micro vessels without losing spectral information. As a result, spectroscopic vis-OCTA can extract microvascular sO2 which are generally inaccessible. Here we extend the theoretical formulation of vis-OCTA oximetry to include optical attenuation, scattering and motion contrast. The model allows robust estimation of sO2, while also promising reduction of illuminating power to 1/3 of current value of ~1 mW. To demonstrate the capability of our approach, we performed oxygen challenge while taking vis-OCTA measurements on rat ocular circulation in vivo. We supplied the experiment animal with the following gas mixture: normal air, 5% CO2 air, pure O2 and 10% O2 air. For each inhalation gas, the OCTA measurements were compared with peripheral capillary sO2 (spO2) provided by a pulse oximeter. The retinal artery sO2 measurements corresponded well with spO2 reading as expected (R2 = 0.87). We found that both retinal and choroidal circulation sO2 moderately increased when we supplied 5% CO2 air. 100% O2 inhalation significantly increased both artery and vein oxygenation. On the contrary, 10% O2 air could deplete the oxygen reservoir in the circulation and lead to low sO2 readings.

  3. High modulation bandwidth of a light-emitting diode with surface plasmon coupling (Conference Presentation)

    Science.gov (United States)

    Lin, Chun-Han; Tu, Charng-Gan; Yao, Yu-Feng; Chen, Sheng-Hung; Su, Chia-Ying; Chen, Hao-Tsung; Kiang, Yean-Woei; Yang, Chih-Chung

    2017-02-01

    Besides lighting, LEDs can be used for indoor data transmission. Therefore, a large modulation bandwidth becomes an important target in the development of visible LED. In this regard, enhancing the radiative recombination rate of carriers in the quantum wells of an LED is a useful method since the modulation bandwidth of an LED is related to the carrier decay rate besides the device RC time constant To increase the carrier decay rate in an LED without sacrificing its output power, the technique of surface plasmon (SP) coupling in an LED is useful. In this paper, the increases of modulation bandwidth by reducing mesa size, decreasing active layer thickness, and inducing SP coupling in blue- and green-emitting LEDs are illustrated. The results are demonstrated by comparing three different LED surface structures, including bare p-type surface, GaZnO current spreading layer, and Ag nanoparticles (NPs) for inducing SP coupling. In a single-quantum-well, blue-emitting LED with a circular mesa of 10 microns in radius, SP coupling results in a modulation bandwidth of 528.8 MHz, which is believed to be the record-high level. A smaller RC time constant can lead to a higher modulation bandwidth. However, when the RC time constant is smaller than 0.2 ns, its effect on modulation bandwidth saturates. The dependencies of modulation bandwidth on injected current density and carrier decay time confirm that the modulation bandwidth is essentially inversely proportional to a time constant, which is inversely proportional to the square-root of carrier decay rate and injected current density.

  4. Light trespass : causes, remedies and actions. Paper presented at the CIE / MBE Symposium "Lighting and Signalling for Transport", Budapest, 22-23 September 1986.

    NARCIS (Netherlands)

    Schreuder, D.A.

    1986-01-01

    Light trespass is the result of light that does not reach its destination, or that is reflected after having reached its destination or is scattered by the media in between source and destination: by light that is "spilled". Light trespass may disturb people for whom the lighting actually is

  5. Dosimetry auditing procedure with alanine dosimeters for light ion beam therapy

    DEFF Research Database (Denmark)

    Ableitinger, Alexander; Vatnitsky, Stanislav; Herrmann, Rochus

    2013-01-01

    fluence in the alanine detector. A pilot run was performed with protons and carbon ions at the Heidelberg Ion Therapy facility (HIT). Results The mean difference of the absolute physical dose measured with the alanine dosimeters compared with the expected dose from the treatment planning system was −2......Background and purpose In the next few years the number of facilities providing ion beam therapy with scanning beams will increase. An auditing process based on an end-to-end test (including CT imaging, planning and dose delivery) could help new ion therapy centres to validate their entire logistic...... chain of radiation delivery. An end-to-end procedure was designed and tested in both scanned proton and carbon ion beams, which may also serve as a dosimetric credentialing procedure for clinical trials in the future. The developed procedure is focused only on physical dose delivery and the validation...

  6. Ion optics of RHIC electron beam ion source

    Energy Technology Data Exchange (ETDEWEB)

    Pikin, A.; Alessi, J.; Beebe, E.; Kponou, A.; Okamura, M.; Raparia, D.; Ritter, J.; Tan, Y. [Brookhaven National Laboratory, Upton, New York 11973 (United States); Kuznetsov, G. [Budker Institute of Nuclear Physics, Novosibirsk 630090 (Russian Federation)

    2012-02-15

    RHIC electron beam ion source has been commissioned to operate as a versatile ion source on RHIC injection facility supplying ion species from He to Au for Booster. Except for light gaseous elements RHIC EBIS employs ion injection from several external primary ion sources. With electrostatic optics fast switching from one ion species to another can be done on a pulse to pulse mode. The design of an ion optical structure and the results of simulations for different ion species are presented. In the choice of optical elements special attention was paid to spherical aberrations for high-current space charge dominated ion beams. The combination of a gridded lens and a magnet lens in LEBT provides flexibility of optical control for a wide range of ion species to satisfy acceptance parameters of RFQ. The results of ion transmission measurements are presented.

  7. Measurements on semiconductor and scintillator detectors at the Advanced Light Source (Conference Presentation)

    Science.gov (United States)

    Camarda, Giuseppe S.; Bolotnikov, Aleksey E.; Cui, Yonggang; Gul, Rubi; Hossain, Anwar; Roy, Utpal N.; Yang, Ge; James, Ralph B.; Vanier, Peter E.

    2016-09-01

    During the transition period between closure of Beamline X27B at BNL's NSLS and the opening of Beamline MID at NSLS-II, we began operation of LBNL's ALS Beamline 3.3.2 to carry out our radiation detection materials RD. Measurements performed at this Beamline include, X-ray Detector Response Mapping and White Beam X-ray Diffraction Topography (WBXDT), among others. We will introduce the capabilities of the Beamline and present the most recent results obtained on CdZnTe and scintillators. The goal of the studies on CdZnTe is to understand the origin and effects of subgrain boundaries and help to visualize the presence of a higher concentration of impurities, which might be responsible for the deterioration of the energy resolution and response uniformity in the vicinity of the sub-grain boundaries. The results obtained in the second year of measurements will be presented.

  8. Light-cured polymer electrolytes for safe, low-cost and sustainable sodium-ion batteries

    Science.gov (United States)

    Colò, Francesca; Bella, Federico; Nair, Jijeesh R.; Gerbaldi, Claudio

    2017-10-01

    In this work we present a very simple preparation procedure of a poly(ethylene oxide) (PEO)-based crosslinked polymer electrolyte (XPE) for application in sodium-ion batteries (NIBs). The polymer electrolyte, containing NaClO4 as Na+ source, is prepared by rapid, energy saving, solvent-free photopolymerization technique, in a single step. Thermal, mechanical, morphological and electrochemical properties of the resulting XPE are thoroughly investigated. The highly ionic conducting (>1 mS cm-1 at 25 °C) polymer electrolyte is used in a lab-scale sodium cell with nanostructured TiO2 working electrode. The obtained results in terms of ambient temperature cycling behaviour (stable specific capacity of about 250 mAh g-1 at 0.1 mA cm-2 and overall remarkable stability, for a quasi-solid state Na polymer cell, upon very long term cycling exceeding 1000 reversible cycles at 0.5 mA cm-2 corresponding to > 5000 h of continuous operation) demonstrate the promising prospects of this novel XPE to be implemented in the next-generation NIBs conceived for large-scale energy storage systems, such as those connected to photovoltaic and wind factories.

  9. Simultaneous presentation of kappa-restricted chronic lymphocytic leukemia and lambda light chain AL amyloidosis.

    Science.gov (United States)

    von Keudell, Gottfried; Sanchorawala, Vaishali; O'Hara, Carl; C Seldin, David; Sloan, J Mark

    2014-06-01

    We report on a 58-year-old man who presented with simultaneous kappa-restricted chronic lymphocytic leukemia (CLL) and a lambda-restricted plasma cell dyscrasia causing AL amyloidosis involving the kidney and GI tract. While monoclonal immunoglobulins occasionally produced by CLL has previously been implicated in AL amyloidosis, this is the first case of AL amyloidosis resulting from a distinct plasma cell dyscrasia that is not clonally related to the concurrent CLL. Appropriate treatment depended on detailed pathologic diagnosis of both disease processes.

  10. Measurement of activation of rhodopsine with heavy ions irradiation in the ALTEA program: a possible mechanism responsible for light flash perceptions in space

    Science.gov (United States)

    Narici, Livio; Rinaldi, Adele; Sannita, Walter, , Prof; Paci, Maurizio; Brunetti, Valentina; de Martino, Angelo; Picozza, Piergiorgio

    Since late 60s astronauts in space have reported seeing flashes of light, more frequently when dark adapted. Experiments have been performed to characterize these phenomena, and to suggest possible mechanisms. High Z ions have been shown to be the most likely cause of these perceptions: when ionizing radiation hits the eye there is a high probability of a light flash perception. However the mechanisms behind this phenomenon are not fully understood yet. We show that one of these mechanisms is the activation of the rhodopsin (bleaching) by heavy ions. Rhodopsin is at the start of the photo-electronic cascade in the process of vision. It is one of the best molecular transducer to convert a visible photon into an electric signal. In this work we show that rhodopsine can also be activated by irradiation with 12C nuclei. In the frame of ALTEA program, aimed at studying the effects of cosmic radiation on brain functions, an investigation on the interaction between heavy ions and rhodopsin has been performed. Intact Rod Outer Segment (ROS) containing rhodopsin were isolated from bovine retina. Suspended rods were irradiated with 12C (200 MeV/n, well below the Cherenkov threshold) at GSI (Darmstadt FRG) with doses ranging from few mrem to several rem. Spectrophotometric measurements investigated the presence of non activated and activated rhodopsin. The functionality of the purified rods were checked by previous light irradiation and subsequent regeneration by the addition of external 11-cis-retinal, to confirm the reversibility of the process in vitro. We can show effective and reversible bleaching also following irradiation, thus proving that the rhodopsin was not damaged by radiation. Works are in progress to model this interaction. Latest analysis results and considerations about the underlying mechanism will be presented.

  11. Adiabatic mode coupler on ion-exchanged waveguides for the efficient excitation of surface plasmon modes (Presentation Recording)

    Science.gov (United States)

    Beltran Madrigal, Josslyn; Berthel, Martin; Gardillou, Florent; Tellez Limon, Ricardo; Couteau, Christophe; Barbier, Denis; Drezet, Aurelien; Salas-Montiel, Rafael; Huant, Serge; Blaize, Sylvain; Geng, Wei

    2015-10-01

    Several works have already shown that the excitation of plasmonic structures through waveguides enables a strong light confinement and low propagation losses [1]. This kind of excitation is currently exploited in areas such as biosensing [2], nanocircuits[3] and spectroscopy[4]. The efficient excitation of surface plasmon modes (SPP) with guided modes supported by high-index-contrast waveguides, such as silicon-on-insulator waveguides, had already been shown [1,5]. However, the use of weakconfined guided modes of a glass ion exchanged waveguide as a SPP excitation source represents a technological challenge, because the mismatch between the size of their respective electromagnetic modes is so high that the resultant coupling loss is unacceptable for practical applications. In this work, we describe how an adiabatic taper structure formed by an intermediate high-index-contrast layer placed between a plasmonic structure and an ion-exchanged waveguide decreases the mismatch between effective indices, size, and shape of the guided modes. This hybrid structure concentrates the electromagnetic energy from the micrometer to the nanometer scale with low coupling losses to radiative modes. The electromagnetic mode confined to the high-index-contrast waveguide then works as an efficient source of SPP supported by metallic nanostructures placed on its surface. We theoretically studied the modal properties and field distribution along the adiabatic coupler structure. In addition, we fabricated a high-index-contrast waveguide by electron beam lithography and thermal evaporation on top of an ion-exchanged waveguide on glass. This structure was characterized with the use of near field scanning optical microscopy (NSOM). Numerical simulations were compared with the experimental results. [1] N. Djaker, R. Hostein, E. Devaux, T. W. Ebbesen, and H. Rigneault, and J. Wenger, J. Phys. Chem. C 114, 16250 (2010). [2] P. Debackere, S. Scheerlinck, P. Bienstman, R. Baets, Opt. Express 14

  12. Hybrid nanowire ion-to-electron transducers for integrated bioelectronic circuitry (Conference Presentation)

    Science.gov (United States)

    Carrad, Damon J.; Mostert, Bernard; Meredith, Paul; Micolich, Adam P.

    2016-09-01

    A key task in bioelectronics is the transduction between ionic/protonic signals and electronic signals at high fidelity. This is a considerable challenge since the two carrier types exhibit intrinsically different physics. We present our work on a new class of organic-inorganic transducing interface utilising semiconducting InAs and GaAs nanowires directly gated with a proton transporting hygroscopic polymer consisting of undoped polyethylene oxide (PEO) patterned to nanoscale dimensions by a newly developed electron-beam lithography process [1]. Remarkably, we find our undoped PEO polymer electrolyte gate dielectric [2] gives equivalent electrical performance to the more traditionally used LiClO4-doped PEO [3], with an ionic conductivity three orders of magnitude higher than previously reported for undoped PEO [4]. The observed behaviour is consistent with proton conduction in PEO. We attribute our undoped PEO-based devices' performance to the small external surface and high surface-to-volume ratio of both the nanowire conducting channel and patterned PEO dielectric in our devices, as well as the enhanced hydration afforded by device processing and atmospheric conditions. In addition to studying the basic transducing mechanisms, we also demonstrate high-fidelity ionic to electronic conversion of a.c. signals at frequencies up to 50 Hz. Moreover, by combining complementary n- and p-type transducers we demonstrate functional hybrid ionic-electronic circuits can achieve logic (NOT operation), and with some further engineering of the nanowire contacts, potentially also amplification. Our device structures have significant potential to be scaled towards realising integrated bioelectronic circuitry. [1] D.J. Carrad et al., Nano Letters 14, 94 (2014). [2] D.J. Carrad et al., Manuscript in preparation (2016). [3] S.H. Kim et al., Advanced Materials 25, 1822 (2013). [4] S.K. Fullerton-Shirey et al., Macromolecules 42, 2142 (2009).

  13. Light and collisions: Julius von Bismark presents an update on his work after his CERN Residency

    CERN Multimedia

    2012-01-01

    On 27 June 2012, Julius von Bismarck, the first winner of the Prix Ars Electronica Collide@CERN, will give a special informal interim lecture for CERN on his ideas and work in progress.   Julius will disclose his personal reactions to his experiences at CERN, sharing with us how particle physics and the laboratory has started having an impact on his artistic practice. As he said when he won the prize at the first Collide@CERN public lecture: “For me, the Collide@CERN residency is a dream come true.” So has reality matched up with his dreams? And why in the first two weeks did he say: “For me already the residency is already a success.” What is his experience of the creative collisions between arts and science? There will be opportunities for the audience to ask questions, and the artist stresses that this will be a personal and informal presentation of ideas in progress. The lecture will take place in the Council Chamber (Room 503-1-001) from 4.3...

  14. Applications of focused MeV light ion beams for high resolution channeling contrast imaging

    Energy Technology Data Exchange (ETDEWEB)

    Jamieson, D.N.; Breese, M.B.H.; Prawer, S.; Dooley, S.P.; Allen, M.G.; Bettiol, A.A.; Saint, A. [Melbourne Univ., Parkville, VIC (Australia). School of Physics; Ryan, C.G. [Commonwealth Scientific and Industrial Research Organisation (CSIRO), North Ryde, NSW (Australia). Div. of Exploration Geoscience

    1993-12-31

    The technique of Nuclear Microscopy, utilizing a focused ion probe of typically MeV H{sup +} or He{sup +} ions, can produce images where the contrast depends on typical Ion Beam Analysis (lBA) processes. The probe forming lens system usually utilizes strong focusing, precision magnetic quadrupole lenses and the probe is scanned over the target to produce images. Originally, this imaging technique was developed to utilize backscattered particles with incident beam currents typically of a few nA, and the technique became known as Channeling Contrast Microscopy (CCM). Recently, the technique has been developed further to utilize the forward scattering of ions incident along a major crystal axis in thin crystals. This technique is known as Channeling Scanning Transmission Ion Microscopy (CSTIM). Since nearly all incident ions are detected, CSTIM is highly efficient and very low beam currents are sufficient for imaging, typically as low as a few fA. This allows probes as small as 50 nm to be used. In this paper we briefly review the recent applications of these emerging techniques to a variety of single crystal materials (authors). 13 refs., 5 figs.

  15. New light on ion channel imaging by total internal reflection fluorescence (TIRF microscopy

    Directory of Open Access Journals (Sweden)

    Hisao Yamamura

    2015-05-01

    Full Text Available Ion channels play pivotal roles in a wide variety of cellular functions; therefore, their physiological characteristics, pharmacological responses, and molecular structures have been extensively investigated. However, the mobility of an ion channel itself in the cell membrane has not been examined in as much detail. A total internal reflection fluorescence (TIRF microscope allows fluorophores to be imaged in a restricted region within an evanescent field of less than 200 nm from the interface of the coverslip and plasma membrane in living cells. Thus the TIRF microscope is useful for selectively visualizing the plasmalemmal surface and subplasmalemmal zone. In this review, we focused on a single-molecule analysis of the dynamic movement of ion channels in the plasma membrane using TIRF microscopy. We also described two single-molecule imaging techniques under TIRF microscopy: fluorescence resonance energy transfer (FRET for the identification of molecules that interact with ion channels, and subunit counting for the determination of subunit stoichiometry in a functional channel. TIRF imaging can also be used to analyze spatiotemporal Ca2+ events in the subplasmalemma. Single-molecule analyses of ion channels and localized Ca2+ signals based on TIRF imaging provide beneficial pharmacological and physiological information concerning the functions of ion channels.

  16. Description of Light Ion Production Cross Sections and Fluxes on the Mars Surface using the QMSFRG Model

    Science.gov (United States)

    Cucinotta, Francis A.; Kim, Myung-Hee; Schneider, Irene; Hassler, Donald M.

    2006-01-01

    The atmosphere of Mars significantly attenuates the heavy ion component of the primary galactic cosmic rays (GCR), however increases the fluence of secondary light ions (neutrons, and hydrogen and helium isotopes) because of particle production processes. We describe results of the quantum multiple scattering fragmentation (QMSFRG) model for the production of light nuclei through the distinct mechanisms of nuclear abrasion and ablation, coalescence, and cluster knockout. The QMSFRG model is shown to be in excellent agreement with available experimental data for nuclear fragmentation cross sections. We use the QMSFRG model and the space radiation transport code, HZETRN to make predictions of the light particle environment on the Martian surface at solar minimum and maximum. The radiation assessment detector (RAD) experiment will be launched in 2009 as part of the Mars Science Laboratory (MSL). We make predictions of the expected results for time dependent count-rates to be observed by RAD experiment. Finally, we consider sensitivity assessments of the impact of the Martian atmospheric composition on particle fluxes at the surface.

  17. Light ions radiobiological effects on human tumoral cells: measurements modelling and application to hadron-therapy; Mesures et modelisation des effets radiobiologiques des ions legers sur des cellules tumorales humaines: application a l'hadrontherapie

    Energy Technology Data Exchange (ETDEWEB)

    Jalade, P

    2005-11-15

    In classical radiotherapy, the characteristics of photons interactions undergo limits for the treatment of radioresistant and not well located tumours. Pioneering treatments of patients at the Lawrence Laboratory at Berkeley has demonstrated two advantages of hadrons beams: the Relative Biologic Effect (the RBE) and the ballistic of the beams. Since 1994, the clinical centre at Chiba, has demonstrated successfully the applicability of the method. A physics group, managed by G. Kraft, at Darmstadt in Germany, has underlined the advantages of carbon beams. An European pool, called ENGIGHT (European Network for LIGHt ion Therapy) has been created in which the French ETOILE project appeared. The purpose of the thesis concerns measurements and models of 'in vitro' human cells survival. In the first part, the nowadays situation in particles interactions, tracks and cells structures and radiobiology is presented here. The second is devoted to the models based on the beam tracks and localization of the physical dose. Discussion of sensitivity to various parameters of the model has been realized with the help of numerical simulations. Finally the predictions of the improved model has been compared to experimental irradiations of human cells with argon and carbon beams of the GANIL machine. Conclusion of such study shows the performance and limits of a local model for predicting the radiobiological efficiency of light ions in hadron-therapy. (author)

  18. Synergetic effects of I- ions and BiOI on visible-light-activity enhancement of wide-band-gap (BiO)2CO3

    Science.gov (United States)

    Liang, Lei; Cao, Jing; Lin, Haili; Guo, Xiaomin; Zhang, Meiyu; Chen, Shifu

    2017-08-01

    The wide-band-gap semiconductor (BiO)2CO3 was modified by interior doping with I- ions and surface loading with BiOI to prepare a highly efficient visible-light active photocatalyst for the degradation of methyl orange and phenol. The interior I- ions elevate the valence band position of (BiO)2CO3 and induce visible-light photocatalytic activity, while the in-situ-formed BiOI/I-(BiO)2CO3 heterojunction significantly improves the separation of photoinduced charge carriers. By the action of the reactive species h+ and rad O2-, methyl orange and phenol were degraded over the novel BiOI/I-(BiO)2CO3 composite at rates that were 18- and 4-times, respectively, those of unmodified (BiO)2CO3. Thus, the findings presented here may be widely applied in the development of wide-band-gap semiconductor photocatalytic systems for the highly efficient removal of contaminants from wastewater.

  19. Entrance-channel Mass-asymmetry Dependence of Compound-nucleus Formation Time in Light Heavy-ion Reactions

    CERN Document Server

    Szanto de Toledo, A; Beck, C; Thoennessen, M

    1996-01-01

    The entrance-channel mass-asymmetry dependence of the compound nucleus formation time in light heavy-ion reactions has been investigated within the framework of semiclassical dissipative collision models. the model calculations have been succesfully applied to the formation of the $^{38}$Ar compound nucleus as populated via the $^{9}$Be+$^{29}$Si, $^{11}$B+$^{27}$Al, $^{12}$C+$^{26}$Mg and $^{19}$F+$^{19}$F entrance channels. The shape evolution of several other light composite systems appears to be consistent with the so-called "Fusion Inhibition Factor" which has been experimentally observed. As found previously in more massive systems for the fusion-evaporation process, the entrance-channel mass-asymmetry degree of freedom appears to determine the competition between the different mechanisms as well as the time scales involved.

  20. Evaluation of excitation energy and spin from light charged particles multiplicities in heavy-ion collisions

    CERN Document Server

    Steckmeyer, J C; Grotowski, K; Pawowski, P; Aiello, S; Anzalone, A; Bini, M; Borderie, B; Bougault, R; Cardella, G; Casini, G; Cavallaro, S; Charvet, J L; Dayras, R; De Filippo, E; Durand, D; Femin, S; Frankland, J D; Galíchet, E; Geraci, M; Giustolisi, F; Guazzoni, P; Iacono-Manno, M; Lanzalone, G; Lanzan, G; Le Neindre, N; Lo Nigro, S; Lo Piano, F; Olmi, A; Pagano, A; Papa, M; Pârlog, M; Pasquali, G; Piantelli, S; Pirrone, S; Politi, G; Porto, F; Rivet, M F; Rizzo, F; Rosato, E; Roy, R; Sambataro, S; Sperduto, M L; Stefanini, A A; Sutera, C; Tamain, B; Vient, E; Volant, C; Wieleczko, J P; Zetta, L

    2005-01-01

    A simple procedure for evaluating the excitation energy and the spin transfer in heavy-ion dissipative collisions is proposed. It is based on a prediction of the GEMINI evaporation code : for a nucleus with a given excitation energy, the average number of emitted protons decreases with increasing spin, whereas the average number of alpha particles increases. Using that procedure for the reaction 107Ag+58Ni at 52 MeV/nucleon, the excitation energy and spin of quasi-projectiles have been evaluated. The results obtained in this way have been compared with the predictions of a model describing the primary dynamic stage of heavy-ion collisions.

  1. Light and Electron Microscopic Evaluation of Hydrogen Ion-Induced Brain Necrosis

    OpenAIRE

    Petito, C. K.; Kraig, R.P.; Pulsinelli, W. A.

    1987-01-01

    Excessive accumulation of hydrogen ions in the brain may play a pivotal role in initiating the necrosis seen in infarction and following hyperglycemic augmentation of ischemic brain damage. To examine possible mechanisms involved in hydrogen ion-induced necrosis, sequential structural changes in rat brain were examined following intracortical injection of sodium lactate solution (pH 4.5), as compared with injections at pH 7.3. Following pH 7.3 injection, neuronal swelling developed between 1 ...

  2. Dispersive coupling between light and a rare-earth-ion-doped mechanical resonator

    Science.gov (United States)

    Mølmer, Klaus; Le Coq, Yann; Seidelin, Signe

    2016-11-01

    By spectrally hole burning an inhomogeneously broadened ensemble of ions while applying a controlled perturbation, one can obtain spectral holes that are functionalized for maximum sensitivity to different perturbations. We propose to use such hole-burned structures for the dispersive optical interaction with rare-earth-ion dopants whose frequencies are sensitive to crystal strain due to the bending motion of a crystal cantilever. A quantitative analysis shows that good optical sensitivity to the bending motion is obtained if a magnetic-field gradient is applied across the crystal during hole burning and that the resulting optomechanical coupling strength is sufficient for observing quantum features such as zero-point vibrations.

  3. Design and optimization of the PBFA 2 vacuum interface and transmission lines for light ion fusion

    Science.gov (United States)

    McDaniel, D. B.; Stinnett, R. W.; Gray, E. W.

    1985-03-01

    The PBFA II vacuum insulator was originally designed for optimum coupling to a proton ion diode with minimum inductance. In July 1983 it was decided that lithium ions at 30 MeV would be the baseline for PBFA II. This requires the use of plasma opening switches (POS) and vacuum inductor to reach 30 MV. To achieve this, the vacuum magnetically insulated transmission lines had to be redesigned as an inductive energy store. To gain optimum coupling to this vacuum inductors, the output impedance of the water section was increased by the use of a water-dielectric transformer. The calculations leading to the final design will be discussed.

  4. Light

    CERN Document Server

    Robertson, William C

    2003-01-01

    Why is left right and right left in the mirror? Baffled by the basics of reflection and refraction? Wondering just how the eye works? If you have trouble teaching concepts about light that you don t fully grasp yourself, get help from a book that s both scientifically accurate and entertaining with Light. By combining clear explanations, clever drawings, and activities that use easy-to-find materials, this book covers what science teachers and parents need to know to teach about light with confidence. It uses ray, wave, and particle models of light to explain the basics of reflection and refraction, optical instruments, polarization of light, and interference and diffraction. There s also an entire chapter on how the eye works. Each chapter ends with a Summary and Applications section that reinforces concepts with everyday examples. Whether you need a deeper understanding of how light bends or a good explanation of why the sky is blue, you ll find Light more illuminating and accessible than a college textbook...

  5. Biological inspiration in optics and photonics: harnessing nature's light manipulation strategies for multifunctional optical materials (Conference Presentation)

    Science.gov (United States)

    Kolle, Mathias; Sandt, Joseph D.; Nagelberg, Sara N.; Zarzar, Lauren D.; Kreysing, Moritz; Vukusic, Peter

    2016-03-01

    The precise control of light-matter interactions is crucial for the majority of known biological organisms in their struggle to survive. Many species have evolved unique methods to manipulate light in their environment using a variety of physical effects including pigment-induced, spectrally selective absorption or light interference in photonic structures that consist of micro- and nano-periodic material morphologies. In their optical performance, many of the known biological photonic systems are subject to selection criteria not unlike the requirements faced in the development of novel optical technology. For this reason, biological light manipulation strategies provide inspiration for the creation of tunable, stimuli-responsive, adaptive material platforms that will contribute to the development of multifunctional surfaces and innovative optical technology. Biomimetic and bio-inspired approaches for the manufacture of photonic systems rely on self-assembly and bottom-up growth techniques often combined with conventional top-down manufacturing. In this regard, we can benefit in several ways from highly sophisticated material solutions that have convergently evolved in various organisms. We explore design concepts found in biological photonic architectures, seek to understand the mechanisms underlying morphogenesis of bio-optical systems, aim to devise viable manufacturing strategies that can benefit from insight in biological formation processes and the use of established synthetic routines alike, and ultimately strive to realize new photonic materials with tailor-made optical properties. This talk is focused on the identification of biological role model photonic architectures, a brief discussion of recently developed bio-inspired photonic structures, including mechano-sensitive color-tunable photonic fibers and reconfigurable fluid micro-lenses. Potentially, early-stage results in studying and harnessing the structure-forming capabilities of living cells that

  6. Photoelectrocatalytic properties of nitrogen doped TiO2/Ti photoelectrode prepared by plasma based ion implantation under visible light.

    Science.gov (United States)

    Han, Lei; Xin, Yanjun; Liu, Huiling; Ma, Xinxin; Tang, Guangze

    2010-03-15

    Nitrogen doped TiO(2)/Ti photoelectrodes were prepared by a sequence of anodization and plasma based ion implantation (PBII). The properties of this photoelectrode were characterized by scanning electronic microscopy (SEM), atomic force microscopy (AFM), X-ray diffraction (XRD), X-ray photoelectron spectrometry (XPS), Ultra violet/visible light diffuse reflectance spectra (UV/vis/DRS), surface photovoltage (SPV), etc. Photoelectrocatalytic (PEC) performance of N-doped TiO(2)/Ti photoelectrode was tested under visible light irradiation. Their photocatalytic activity was evaluated by degradation of Rhodamine B (Rh.B). The results of XPS showed that nitrogen element was in form of three species, i.e. beta-N, molecular gamma-N and O-Ti-N, which existed in the lattices of TiO(2) and gaps between molecules. The results of UV/vis/DRS spectra and SPV revealed that proper doping of nitrogen could expand the response of photoelectrodes towards visible light and diminish the recombination of photo-generated holes and electrons, respectively. The photoelectrocatalytic activity of N-doped TiO(2)/Ti photoelectrodes was superior to those of undoped one under visible light region irradiation.

  7. Dopant concentration dependence of the response of SiC Schottky diodes to light ions

    Energy Technology Data Exchange (ETDEWEB)

    De Napoli, M. [Dipartimento di Fisica e Astronomia, Universita degli Studi di Catania, Via S. Sofia 64, I-95123 Catania (Italy); Laboratori Nazionali del Sud, Via S. Sofia 62, I-95123 Catania (Italy); Giacoppo, F. [Laboratori Nazionali del Sud, Via S. Sofia 62, I-95123 Catania (Italy); Dipartimento di Fisica, Universita degli Studi di Messina, Via Salita Sperone 31, I-98166 Messina (Italy); Raciti, G. [Dipartimento di Fisica e Astronomia, Universita degli Studi di Catania, Via S. Sofia 64, I-95123 Catania (Italy); Isituto Nazionale di Fisica Nucleare, Sezione di Catania, Via S. Sofia 64, I-95123 Catania (Italy)], E-mail: raciti@lns.infn.it; Rapisarda, E. [Dipartimento di Fisica e Astronomia, Universita degli Studi di Catania, Via S. Sofia 64, I-95123 Catania (Italy); Isituto Nazionale di Fisica Nucleare, Sezione di Catania, Via S. Sofia 64, I-95123 Catania (Italy)

    2009-03-11

    The responses of Silicon Carbide (SiC) Schottky diodes of different dopant concentration to {sup 12}C ions at 14.2, 28.1 and 37.6 MeV incident energies are compared. The relation between the applied reverse bias and the thickness of the depleted epitaxial region is studied for different dopant concentrations. The experimental data show that SiC diodes with lower dopant concentration need lower reverse bias to be depleted. Moreover it has been observed that the energy resolution, measured as a function of the applied reverse bias and of the ions incident energies, does not depend on the dopant concentration. The radiation damage, produced by irradiating SiC diodes of different dopant concentration with {sup 16}O ions at 35.2 MeV, was evaluated by measuring the degradation of both the signal pulse-height and the energy resolution as a function of the {sup 16}O fluence. Diodes having a factor 20 lower dopant concentration exhibit a radiation hardness reduced by 60%. No inversion in the signal at the breakdown fluence was observed for {sup 16}O ions stopped inside the diode epitaxial region.

  8. Selective Aerobic Oxidation of Benzyl Alcohol Driven by Visible Light on Gold Nanoparticles Supported on Hydrotalcite Modified by Nickel Ion

    Directory of Open Access Journals (Sweden)

    Dapeng Guo

    2016-04-01

    Full Text Available A series of hydrotalcite (HT and hydrotalcite modified by the transition metal ion Ni(II was prepared with a modified coprecipitation method before being loaded with gold nanoparticles. The gold supported on Ni3Al hydrotalcite with a Ni2+/Al3+ molar ratio of 3:1 was investigated. Different techniques such as X-ray diffraction (XRD, X-ray photoelectron spectroscopy (XPS and UV-vis diffuse reflection spectrum (UV-vis DRS were applied to characterize the catalysts. A single-phase catalyst with high crystallinity, a layered structure and good composition was successfully fabricated. Good conversions and superior selectivities in the oxidation of benzyl alcohol and its derivatives were obtained with visible light due to the effect of localized surface plasmon resonance (LSPR of gold nanoparticles and the synergy of the transition metal ion Ni(II. This reaction was proven to be photocatalytic by varying the intensity and wavelength of the visible light. The catalyst can be recycled three times. A corresponding photocatalytic mechanism of the oxidation reaction of benzyl alcohol was proposed.

  9. Making Mass Spectrometry See the Light: The Promises and Challenges of Cryogenic Infrared Ion Spectroscopy as a Bioanalytical Technique.

    Science.gov (United States)

    Cismesia, Adam P; Bailey, Laura S; Bell, Matthew R; Tesler, Larry F; Polfer, Nicolas C

    2016-05-01

    The detailed chemical information contained in the vibrational spectrum of a cryogenically cooled analyte ion would, in principle, make infrared (IR) ion spectroscopy a gold standard technique for molecular identification in mass spectrometry. Despite this immense potential, there are considerable challenges in both instrumentation and methodology to overcome before the technique is analytically useful. Here, we discuss the promise of IR ion spectroscopy for small molecule analysis in the context of metabolite identification. Experimental strategies to address sensitivity constraints, poor overall duty cycle, and speed of the experiment are intimately tied to the development of a mass-selective cryogenic trap. Therefore, the most likely avenues for success, in the authors' opinion, are presented here, alongside alternative approaches and some thoughts on data interpretation.

  10. Investigation of low-resistivity from hydrogenated lightly B-doped diamond by ion implantation

    Directory of Open Access Journals (Sweden)

    Cui Xia Yan et al

    2008-01-01

    Full Text Available We have implanted boron (B ions (dosage: 5×1014 cm-2 into diamond and then hydrogenated the sample by implantating hydrogen ions at room temperature. A p-type diamond material with a low resistivity of 7.37 mΩ cm has been obtained in our experiment, which suggests that the hydrogenation of B-doped diamond results in a low-resistivity p-type material. Interestingly, inverse annealing, in which carrier concentration decreased with increasing annealing temperature, was observed at annealing temperatures above 600 °C. In addition, the formation mechanism of a low-resistivity material has been studied by density functional theory calculation using a plane wave method.

  11. Red light generation through the lead boro-telluro-phosphate glasses activated by Eu3+ ions

    Science.gov (United States)

    Selvi, S.; Marimuthu, K.; Suriya Murthy, N.; Muralidharan, G.

    2016-09-01

    Lead boro-telluro-phosphate glasses containing 0.05 to 2.0 wt% of Eu3+ ions were prepared through melt quenching technique. Structural characteristics of title glasses were identified through XRD, FTIR and Raman studies. The optical properties of the prepared glasses were studied using UV-Vis-NIR absorption and photoluminescence spectra. From the resultant spectra, we have obtained the bonding parameters (δ), nephelauxetic ratio (β), direct and indirect band gaps and Urbach energy (ΔE) values. A deep red luminescence due to 5D0 → 7F2 transition of Eu3+ ions could be observed for the title glasses. The local site symmetry around the Eu3+ ions and the degree of Eu3+-O2- covalence were assessed from the luminescence intensity ratio of 5D0 → 7F2/5D0 → 7F1 transitions. Judd-Ofelt intensity parameters, calculated from the luminescence spectra, were used to estimate the radiative parameters like transition probability (A), branching ratio (βexp, βcal) and stimulated emission cross-section (σPE) concerning the 5D0 → 7FJ (J = 0, 1, 2, 3 and 4) transitions. The important laser parameters, gain bandwidth and optical gain are also estimated. The decay curves associated with the transition from 5D0 state was found to be single-exponential at all Eu3+ ion concentrations. CIE colour coordinates and colour purity of the prepared glasses were estimated from the CIE chromaticity diagram.

  12. The stopping power and energy straggling of light ions in graphene oxide foils

    Science.gov (United States)

    Mikšová, R.; Macková, A.; Malinský, P.; Sofer, Z.

    2017-09-01

    Energy-loss and straggling experiments were performed using 2-4 MeV 1H+ and 7.4-9.0 MeV 4He2+ ions in graphene oxide foils by the transmission technique. The thickness of the graphene oxide foils was determined using a detailed image analysis of a graphene oxide cut, which was used to refine the graphene oxide density. The density was determined by the standard technique of micro-balance weighing. The stoichiometry of the graphene oxide foils before the irradiation was determined by Rutherford backscattering spectrometry (RBS) and elastic recoil detection analysis (ERDA) using 2 and 2.5 MeV 4He+. The measured energy stopping powers for hydrogen and helium ions in graphene oxide were compared with the predictions obtained from the SRIM-2013 code. The energy straggling was compared with that calculated using Bohr's, Bethe-Livingston and Yang predictions. The results show that the stopping power of graphene oxide foils irradiated by both ion species decreases with increasing energies, the differences between the measured and predicted values being below 3.8%. The energy straggling determined in our experiment is higher than Bohr's and Bethe-Livingston predicted values; the predictions by Yang are in better agreement with our experiment.

  13. Arthur L. Schawlow Prize in Laser Science Talk: Trapped Ion Quantum Networks with Light

    Science.gov (United States)

    Monroe, Christopher

    2015-05-01

    Laser-cooled atomic ions are standards for quantum information science, acting as qubit memories with unsurpassed levels of quantum coherence while also allowing near-perfect measurement. When qubit state-dependent optical dipole forces are applied to a collection of trapped ions, their Coulomb interaction is modulated in a way that allows the entanglement of the qubits through quantum gates that can form the basis of a quantum computer. Similar optical forces allow the simulation of quantum many-body physics, where recent experiments are approaching a level of complexity that cannot be modelled with conventional computers. Scaling to much larger numbers of qubits can be accomplished by coupling trapped ion qubits through optical photons, where entanglement over remote distances can be used for quantum communication and large-scale distributed quantum computers. Laser sources and quantum optical techniques are the workhorse for such quantum networks, and will continue to lead the way as future quantum hardware is developed. This work is supported by the ARO with funding from the IARPA MQCO program, the DARPA Quiness Program, the ARO MURI on Hybrid Quantum Circuits, the AFOSR MURIs on Quantum Transduction and Quantum Verification, and the NSF Physics Frontier Center at JQI.

  14. Full solar spectrum light driven thermocatalysis with extremely high efficiency on nanostructured Ce ion substituted OMS-2 catalyst for VOCs purification

    Science.gov (United States)

    Hou, Jingtao; Li, Yuanzhi; Mao, Mingyang; Yue, Yuanzheng; Greaves, G. Neville; Zhao, Xiujian

    2015-01-01

    The nanostructured Ce ion substituted cryptomelane-type octahedral molecular sieve (OMS-2) catalyst exhibits strong absorption in the entire solar spectrum region. The Ce ion substituted OMS-2 catalyst can efficiently transform the absorbed solar energy to thermal energy, resulting in a considerable increase of temperature. By combining the efficient photothermal conversion and thermocatalytic activity of the Ce ion substituted OMS-2 catalyst, we carried out full solar spectrum, visible-infrared, and infrared light driven catalysis with extremely high efficiency. Under the irradiation of full solar spectrum, visible-infrared, and infrared light, the Ce ion substituted OMS-2 catalyst exhibits extremely high catalytic activity and excellent durability for the oxidation of volatile organic pollutants such as benzene, toluene, and acetone. Based on the experimental evidence, we propose a novel mechanism of solar light driven thermocatalysis for the Ce ion substituted OMS-2 catalyst. The reason why the Ce ion substituted OMS-2 catalyst exhibits much higher catalytic activity than pure OMS-2 and CeO2/OMS-2 nano composite under the full solar spectrum irradiation is discussed.The nanostructured Ce ion substituted cryptomelane-type octahedral molecular sieve (OMS-2) catalyst exhibits strong absorption in the entire solar spectrum region. The Ce ion substituted OMS-2 catalyst can efficiently transform the absorbed solar energy to thermal energy, resulting in a considerable increase of temperature. By combining the efficient photothermal conversion and thermocatalytic activity of the Ce ion substituted OMS-2 catalyst, we carried out full solar spectrum, visible-infrared, and infrared light driven catalysis with extremely high efficiency. Under the irradiation of full solar spectrum, visible-infrared, and infrared light, the Ce ion substituted OMS-2 catalyst exhibits extremely high catalytic activity and excellent durability for the oxidation of volatile organic pollutants

  15. Characterization of surface modifications by white light interferometry: applications in ion sputtering, laser ablation, and tribology experiments.

    Science.gov (United States)

    Baryshev, Sergey V; Erck, Robert A; Moore, Jerry F; Zinovev, Alexander V; Tripa, C Emil; Veryovkin, Igor V

    2013-02-27

    In materials science and engineering it is often necessary to obtain quantitative measurements of surface topography with micrometer lateral resolution. From the measured surface, 3D topographic maps can be subsequently analyzed using a variety of software packages to extract the information that is needed. In this article we describe how white light interferometry, and optical profilometry (OP) in general, combined with generic surface analysis software, can be used for materials science and engineering tasks. In this article, a number of applications of white light interferometry for investigation of surface modifications in mass spectrometry, and wear phenomena in tribology and lubrication are demonstrated. We characterize the products of the interaction of semiconductors and metals with energetic ions (sputtering), and laser irradiation (ablation), as well as ex situ measurements of wear of tribological test specimens. Specifically, we will discuss: i. Aspects of traditional ion sputtering-based mass spectrometry such as sputtering rates/yields measurements on Si and Cu and subsequent time-to-depth conversion. ii. Results of quantitative characterization of the interaction of femtosecond laser irradiation with a semiconductor surface. These results are important for applications such as ablation mass spectrometry, where the quantities of evaporated material can be studied and controlled via pulse duration and energy per pulse. Thus, by determining the crater geometry one can define depth and lateral resolution versus experimental setup conditions. iii. Measurements of surface roughness parameters in two dimensions, and quantitative measurements of the surface wear that occur as a result of friction and wear tests. Some inherent drawbacks, possible artifacts, and uncertainty assessments of the white light interferometry approach will be discussed and explained.

  16. Surgical instrument biocontaminant fluorescence detection in ambient lighting conditions for hospital reprocessing and sterilization department (Conference Presentation)

    Science.gov (United States)

    Baribeau, François; Bubel, Annie; Dumont, Guillaume; Vachon, Carl; Lépine, André; Rochefort, Stéphane; Massicotte, Martin; Buteau-Vaillancourt, Louis; Gallant, Pascal; Mermut, Ozzy

    2017-03-01

    Hospitals currently rely on simple human visual inspection for assessing cleanliness of surgical instruments. Studies showed that surgical site infections are in part attributed to inadequate cleaning of medical devices. Standards groups recognize the need to objectively quantify the amount of residues on surgical instruments and establish guidelines. We developed a portable technology for the detection of contaminants on surgical instruments through fluorescence following cleaning. Weak fluorescence signals are usually detected in the obscurity only with the lighting of the excitation source. The key element of this system is that it works in ambient lighting conditions, a requirement to not disturb the normal workflow of hospital reprocessing facilities. A biocompatible fluorescent dye is added to the detergent and labels the proteins of organic residues. It is resistant to the harsh environment in a washer-disinfector. Two inspection devices have been developed with a 488nm laser as the excitation source: a handheld scanner and a tabletop station using spectral-domain and time-domain ambient light cancellation schemes. The systems are eye safe and equipped with image processing and interfacing software to provide visual or audible warnings to the operator based on a set of adjustable signal thresholds. Micron-scale residues are detected by the system which can also evaluate soil size and mass. Unlike swabbing, it can inspect whole tools in real-time. The technology has been validated in an independent hospital decontamination research laboratory. It also has potential applications in the forensics, agro-food, and space fields. Technical aspects and results will be presented and discussed.

  17. Crystal fields at light rare-earth ions in Y and Lu

    DEFF Research Database (Denmark)

    Touborg, P.; Nevald, Rolf; Johansson, Torben

    1978-01-01

    Crystal-field parameters have been deduced for the light rare-earth solutes Ce, Pr, and Nd in Y or Lu hosts from measurements of the paramagnetic susceptibilities. In the analysis all multiplets in the lowest LS term were included. For a given host, crystal-field parameters divided by Stevens fac...

  18. Light

    CERN Document Server

    Ditchburn, R W

    2011-01-01

    This classic study, available for the first time in paperback, clearly demonstrates how quantum theory is a natural development of wave theory, and how these two theories, once thought to be irreconcilable, together comprise a single valid theory of light. Aimed at students with an intermediate-level knowledge of physics, the book first offers a historical introduction to the subject, then covers topics such as wave theory, interference, diffraction, Huygens' Principle, Fermat's Principle, and the accuracy of optical measurements. Additional topics include the velocity of light, relativistic o

  19. Two-color above threshold ionization of atoms and ions in XUV Bessel beams and combined with intense laser light

    CERN Document Server

    Seipt, D; Surzhykov, A; Fritzsche, S

    2016-01-01

    The two-color above-threshold ionization (ATI) of atoms and ions is investigated for a vortex Bessel beam in the presence of a strong near-infrared (NIR) light field. While the photoionization is caused by the photons from the weak but extreme ultra-violet (XUV) vortex Bessel beam, the energy and angular distribution of the photoelectrons and their sideband structure are affected by the plane-wave NIR field. We here explore the energy spectra and angular emission of the photoelectrons in such two-color fields as a function of the size and location of the target (atoms) with regard to the beam axis. In addition, analogue to the circular dichroism in typical two-color ATI experiments with circularly polarized light, we define and discuss seven different dichroism signals for such vortex Bessel beams that arise from the various combinations of the orbital and spin angular momenta of the two light fields. For localized targets, it is found that these dichroism signals strongly depend on the size and position of t...

  20. Salts and nutrients present in regenerated waters induce changes in water relations, antioxidative metabolism, ion accumulation and restricted ion uptake in Myrtus communis L. plants.

    Science.gov (United States)

    Acosta-Motos, José R; Alvarez, Sara; Barba-Espín, Gregorio; Hernández, José A; Sánchez-Blanco, María J

    2014-12-01

    The use of reclaimed water (RW) constitutes a valuable strategy for the efficient management of water and nutrients in landscaping. However, RW may contain levels of toxic ions, affecting plant production or quality, a very important aspect for ornamental plants. The present paper evaluates the effect of different quality RWs on physiological and biochemical parameters and the recovery capacity in Myrtus communis L. plants. M. communis plants were submitted to 3 irrigation treatments with RW from different sources (22 weeks): RW1 (1.7 dS m(-1)), RW2 (4.0 dS m(-1)) and RW3 (8.0 dS m(-1)) and one control (C, 0.8 dS m(-1)). During a recovery period of 11 weeks, all plants were irrigated with the control water. The RW treatments did not negatively affect plant growth, while RW2 even led to an increase in biomass. After recovery,only plants irrigated with RW3 showed some negative effects on growth, which was related to a decrease in the net photosynthesis rate, higher Na accumulation and a reduction in K levels. An increase in salinity was accompanied by decreases in leaf water potential, relative water content and gas exchange parameters, and increases in Na and Cl uptake. Plants accumulated Na in roots and restricted its translocation to the aerial part. The highest salinity levels produced oxidative stress, as seen from the rise in electrolyte leakage and lipid peroxidation. The use of regenerated water together with carefully managed drainage practices, which avoid the accumulation of salt by the substrate, will provide economic and environmental benefits.

  1. Reference dosimetry for light-ion beams based on graphite calorimetry.

    Science.gov (United States)

    Rossomme, S; Palmans, H; Thomas, R; Lee, N; Duane, S; Bailey, M; Shipley, D; Bertrand, D; Romano, F; Cirrone, P; Cuttone, G; Vynckier, S

    2014-10-01

    Developments in hadron therapy require efforts to improve the accuracy of the dose delivered to a target volume. Here, the determination of the absorbed dose under reference conditions was analysed. Based on the International Atomic Energy Agency TRS-398 code of practice, for hadron beams, the combined standard uncertainty on absorbed dose to water under reference conditions, derived from ionisation chambers, is too large. This uncertainty is dominated by the beam quality correction factors, [Formula: see text], mainly due to the mean energy to produce one ion pair in air, wair. A method to reduce this uncertainty is to carry out primary dosimetry, using calorimetry. A [Formula: see text]-value can be derived from a direct comparison between calorimetry and ionometry. Here, this comparison is performed using a graphite calorimeter in an 80-MeV A(-1) carbon ion beam. Assuming recommended TRS-398 values of water-to-graphite stopping power ratio and the perturbation factor for an ionisation chamber, preliminary results indicate a wair-value of 35.5 ± 0.9 J C(-1). © The Author 2013. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  2. Full Solar Spectrum Light Driven Thermocatalysis with Extremely High Efficiency on Nanostructured Ce Ion Substituted OMS-2 Catalyst for VOCs Purification

    DEFF Research Database (Denmark)

    Hou, J.T.; Li, Y.Z.; Mao, M.Y.

    2015-01-01

    The nanostructured Ce ion substituted cryptomelane-type octahedral molecular sieve (OMS-2) catalyst exhibits strong absorption in the entire solar spectrum region. The Ce ion substituted OMS-2 catalyst can efficiently transform the absorbed solar energy to thermal energy, resulting...... in a considerable increase of temperature. By combining the efficient photothermal conversion and thermocatalytic activity of the Ce ion substituted OMS-2 catalyst, we carried out full solar spectrum, visible-infrared, and infrared light driven catalysis with extremely high efficiency. Under the irradiation of full...... solar spectrum, visible-infrared, and infrared light, the Ce ion substituted OMS-2 catalyst exhibits extremely high catalytic activity and excellent durability for the oxidation of volatile organic pollutants such as benzene, toluene, and acetone. Based on the experimental evidence, we propose a novel...

  3. Light ion facility projects in Europe: methodological aspects for the calculation of the treatment cost per protocol.

    Science.gov (United States)

    Pommier, Pascal; Zucca, Luciano; Näslund, Ingemar; Auberger, Thomas; Combs, Stephanie E; François, Guy; Heeren, Germaine; Rochat, Joël; Perrier, Lionel

    2004-12-01

    In the framework of the European Network for Research in Light Ion Hadron Therapy (ENLIGHT), the health economics group develops a methodology for assessing important investment and operating costs of this innovative treatment against its expected benefits. The main task is to estimate the cost per treated patient. The cost analysis is restricted to the therapeutic phase from the hospital point of view. An original methodology for cost assessment per treatment protocol is developed based on standard costs. Costs related to direct medical activity are based on the production process analysis, whereas indirect and non direct medical costs are allocated to each protocol using relevant cost-drivers. The resulting cost model will take into account the specificities of each therapeutic protocol as well as the particularities of each of the European projects.

  4. The relationship between visible light emission and species fraction of the hydrogen ion beams extracted from 2.45 GHz microwave discharge

    CERN Document Server

    Cortázar, O D; Tarvainen, O; Kalvas, T; Koivisto, H

    2015-01-01

    The relationship between Balmer-α and Fulcher-band emissions with extracted H +, H+2 , and H+3 ions is demonstrated for a 2.45 GHz microwave discharge. Ion mass spectra and optical measurements of Balmer-α and Fulcher-band emissions have been obtained with a Wien Filter having an optical view-port on the plasma chamber axis. The beam of approximately 1 mA is analyzed for different plasma conditions simultaneously with the measurement of light emissions both with temporal resolution. The use of visible light emissions as a valuable diagnostic tool for monitoring the species fraction of the extracted beams is proposed.

  5. Flexible inorganic light emitting diodes and transparent PEDOT:PSS/Parylene C for simultaneous optogenetics and electrocorticography (Conference Presentation)

    Science.gov (United States)

    Lee, Keundong; Ganji, Mehran; Hossain, Lorraine; Ro, Yun Goo; Lee, Sang Heon; Park, Jong-woo; Yoo, Dongha; Yoon, Jiyoung; Yi, Gyu-Chul; Dayeh, Shadi A.

    2017-02-01

    Electrocorticography (ECoG) is a powerful tool for direct mapping of local field potentials from the brain surface. Progress in development of high-fidelity materials such as poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) on thin conformal substrates such as parylene C enabled intimate contact with cortical surfaces and higher quality recordings from small volumes of neurons. Meanwhile, stimulation of neuronal activity is conventionally accomplished with electrical microstimulation and transcranial magnetic stimulation that can be combined with ECoG to form the basis of bidirectional neural interface. However, these stimulation mechanisms are less controlled and primitively understood on the local and cellular levels. With the advent of optogenetics, the localization and specificity of neuronal stimulation and inhibition is possible. Therefore, the development of integrated devices that can merge the sensitivity of ECoG or depth recording with optogenetic tools can lead to newer frontiers in understanding the neuronal activity. Herein, we introduce a hybrid device comprising flexible inorganic LED arrays integrated PEDOT:PSS/parylene C microelectrode arrays for high resolution bidirectional neuronal interfaces. The flexible inorganic LEDs have been developed by the metal-organic vapor phase epitaxy of position-controlled GaN microLEDs on ZnO nanostructured templates pre-grown at precise locations on a graphene layer. By transferring it onto the microelectrode arrays, it can provides the individual electrical addressability by light stimulation patterns. We will present experimental and simulation results on the optoelectronic characteristics and light activation capability of flexible microLEDs and their evaluation in vivo.

  6. The role of the counter-ions present in syntheses on the thermal stabilization of strontium and/or calcium apatites

    Energy Technology Data Exchange (ETDEWEB)

    Melo da Silva, Leila; Santos Menezes, Daniela dos; Almeida, Luis Eduardo [Laboratório de Biomateriais – P" 2CEM, Universidade Federal de Sergipe, Av. Marechal Rondon, s/n, São Cristóvão, 49100-000 Sergipe (Brazil); Anselme, Karine; Dentzer, Joseph [Institut de Science des Matériaux de Mulhouse (IS2M), CNRS UMR7361, Université de Haute-Alsace, 15, rue Jean Starcky, BP 2488, 68057 Mulhouse (France); Araujo dos Santos, Euler, E-mail: euler@ufs.br [Laboratório de Biomateriais – P" 2CEM, Universidade Federal de Sergipe, Av. Marechal Rondon, s/n, São Cristóvão, 49100-000 Sergipe (Brazil)

    2015-09-15

    Highlights: • Counter-ions present in syntheses can affect thermal stabilization of apatites. • Ions with different charges and sizes can stabilize the apatite structure. • Co-substitution is an important way to design biomimetic hydroxyapatites. - Abstract: The goal of this work was to study the thermal stabilization of calcium apatites in which the Ca{sup 2+} ions were substituted for Sr{sup 2+} in increasing concentrations via ionic co-substitutions. Two distinct standard syntheses were proposed for comparative purposes: one using counter-ions that were not easily incorporated into the apatite structure (NH{sub 4}{sup +}/NO{sub 3}{sup −}) and one using counter-ions that can be easily incorporated into the structure (Na{sup +}/Cl{sup −}). After calcination, only the apatites synthesized in the presence of NH{sub 4}{sup +}/NO{sub 3}{sup −} presented phase transformation. In contrast, the apatites synthesized in the presence of Na{sup +}/Cl{sup −} formed a solid solution after calcination, with Na{sup +}, Ca{sup 2+}, Sr{sup 2+} and Cl{sup −} sharing the same apatite lattice. Wavelength dispersive X-ray fluorescence spectroscopy (WDXRF), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and temperature-programmed desorption (TPD) techniques showed that the counter-ions present during the syntheses that are associated with CO{sub 3}{sup 2−} play an important role in the thermal stabilization of the apatites.

  7. Correlations between the fragmentation modes and light charged particles emission in heavy ion collisions

    CERN Document Server

    Zhang, Yingxun; Chen, Jixian; Wang, Ning; Zhao, Kai; Li, Zhuxia

    2015-01-01

    The correlations between the shape of rapidity distribution of the yield of light charged particles and the fragmentation modes in semi-peripheral collisions for $^{70}$Zn+$^{70}$Zn, $^{64}$Zn+$^{64}$Zn and $^{64}$Ni+$^{64}$Ni at the beam energy of 35MeV/nucleon are investigated based on ImQMD05 code. Our studies show there is an interplay between the binary, ternary and multi-fragmentation break-up modes. The binary and ternary break-up modes more prefer to emit light charged particles at middle rapidity and give larger values of $R_{yield}^{mid}$ compared with the multi-fragmentation break-up mode does. The reduced rapidity distribution for the normalized yields of p, d, t, $^3$He, $^4$He and $^6$He and the corresponding values of $R_{yield}^{mid}$ can be used to estimate the probability of multi-fragmentation break-up modes. By comparing to experimental data, our results illustrate that $\\ge$40\\% of the collisions events belong to the multi-fragmentation break-up mode for the reactions we studied.

  8. Correlation between the fragmentation modes and light charged particles emission in heavy ion collisions

    Institute of Scientific and Technical Information of China (English)

    ZHANG YingXun[1; ZHOU ChengShuang[1,2; CHEN JiXian[1,2; WANG Ning[2; ZHAO Kai[1; LI ZhuXia[1

    2015-01-01

    The correlation between the shape of rapidity distribution of the yield of light charged particles and the fragmentation modes in semi-peripheral collisions for 70Zn+70Zn, 64Zn+64Zn and 64Ni+64Ni at the beam energy of 35 MeV/nucleon is investigated based on ImQMD05 code. Our studies show there is an interplay between the binary, ternary and multi-fragmentation break-up modes. The binary and ternary break-up modes more prefer to emit light charged particles at middle rapidity and give larger values of Rmid compared with the multi-fragmentation break-up mode does. The reduced rapidity distribution for the normalized yields of yield p, d, t, 3He, 4He and 6He and the corresponding values ~ Rmid oI yield can be used to estimate the probability of multi-fragmentation break-up modes. By comparing to experimental data, our results illustrate that ~40% of the collisions events belong to the multi- fragmentation break-up mode for the reactions we studied.

  9. The search for electric dipole moments of light ions in storage rings

    Science.gov (United States)

    Rathmann, Frank; Saleev, Artem; Nikolaev, N. N.; Jedi; srEdm Collaborations

    2013-07-01

    The Standard Model (SM) of Particle Physics is not capable of accounting for the apparent matter-antimatter asymmetry of our universe. Physics beyond the SM is required and is searched for by (i) employing highest energies (e.g., at LHC), and (ii) striving for ultimate precision and sensitivity (e.g., in the search for electric dipole moments (EDMs)). Permanent EDMs of particles violate both time reversal (T) and parity (P) invariance, and are via the CPT-theorem also CP-violating. Finding an EDM would be a strong indication for physics beyond the SM, and reducing upper limits further provides crucial tests for any corresponding theoretical model, e.g., SUSY. Direct searches for proton and deuteron EDMs bear the potential to reach sensitivities beyond 10-29 e·cm. For an all-electric proton storage ring, this goal is pursued by the US-based srEDM collaboration [1], while the newly founded Jülich-based JEDI collaboration [2] is pursuing an approach using a combined electric-magnetic lattice, which shall provide access to the EDMs of protons, deuterons, and 3He ions in the same machine. In addition, JEDI has recently proposed making a direct measurement of the proton and/or deuteron EDM at COSY using resonant techniques involving Wien filters.

  10. Search for electric dipole moments of light ions in storage rings

    Science.gov (United States)

    Rathmann, F.; Saleev, A.; Nikolaev, N. N.

    2014-01-01

    The Standard Model (SM) of Particle Physics is not capable to account for the apparent matterantimatter asymmetry of our Universe. Physics beyond the SM is required and is searched for by (i) employing highest energies (e.g., at LHC), and (ii) striving for ultimate precision and sensitivity (e.g., in the search for electric dipole moments (EDMs)). Permanent EDMs of particles violate both time reversal ( T) and parity ( P) invariance, and are via the CPT-theorem also CP-violating. Finding an EDM would be a strong indication for physics beyond the SM, and pushing upper limits further provides crucial tests for any corresponding theoretical model, e.g., SUSY. Direct searches of proton and deuteron EDMs bear the potential to reach sensitivities beyond 10-29 e cm. For an all-electric proton storage ring, this goal is pursued by the US-based srEDM collaboration [2], while the newly found Julich-based JEDI collaboration [1] is pursuing an approach using a combined electric-magnetic lattice which shall provide access to the EDMs of protons, deuterons, and 3He ions in the same machine. In addition, JEDI has recently proposed to perform a direct measurement of the proton and/or deuteron EDM at COSY using resonant techniques involving Wien filters.

  11. High-fidelity functional and structural whole-brain imaging with Bessel-beam light-sheet microscopy (Conference Presentation)

    Science.gov (United States)

    Müllenbroich, Marie Caroline; Silvestri, Ludovico; Turrini, Lapo; Di Giovanna, Antonino Paolo; Alterini, Tommaso; Gheisari, Ali; Ricci, Pietro; Sacconi, Leonardo; Vanzi, Francesco; Pavone, Francesco S.

    2017-02-01

    Light-sheet microscopy (LSM) has proven a useful tool in neuroscience and is particularly well suited to image the entire brain with high frame rates at single cell resolution. On the one hand, LSM is employed in combination with tissue clearing methods like CLARITY which allows for the reconstruction of neuronal or vascular anatomy over cm-sized samples. On the other hand, LSM has been paired with intrinsically transparent samples for real-time recording of neuronal activity with single cell resolution across the entire brain, using calcium indicators like GCaMP6. Despite its intrinsic advantages in terms of high imaging speed and reduced photobleaching, LSM is very sensitive to residual opaque objects present in the sample, which cause dark horizontal stripes in the collected images. In the best case, these artefacts obscure the features of interest in structural imaging; in the worst case, dynamic shadowing introduced by red blood cells significantly alters the fluorescence signal variations related to neuronal activity. We show how the use of Bessel beams in LSM can dramatically reduce such artefacts even in conventional one-sided illumination schemes, thanks to their "self-healing" properties. On the functional side, Bessel-beam LSM allows recording neuronal activity traces without any disturbing flickering caused by the movement of red blood cells. On the structural side, our proposed method is capable of obtaining anatomical information across the entire volume of whole mouse brains allowing tracing blood vessels and neuronal projections also in poorly cleared specimens.

  12. Manipulating femtosecond laser interactions in bulk glass and thin-film with spatial light modulation (Conference Presentation)

    Science.gov (United States)

    Alimohammadian, Ehsan; Ho, Stephen; Ertorer, Erden; Gherghe, Sebastian; Li, Jianzhao; Herman, Peter R.

    2017-03-01

    Spatial Light Modulators (SLM) are emerging as a power tool for laser beam shaping whereby digitally addressed phase shifts can impose computer-generated hologram patterns on incoming laser light. SLM provide several additional advantages with ultrashort-pulsed lasers in controlling the shape of both surface and internal interactions with materials. Inside transparent materials, nonlinear optical effects can confine strong absorption only to the focal volume, extend dissipation over long filament tracks, or reach below diffraction-limited spot sizes. Hence, SLM beam shaping has been widely adopted for laser material processing applications that include parallel structuring, filamentation, fiber Bragg grating formation and optical aberration correction. This paper reports on a range of SLM applications we have studied in femtosecond processing of transparent glasses and thin films. Laser phase-fronts were tailored by the SLM to compensate for spherical surface aberration, and to further address the nonlinear interactions that interplay between Kerr-lens self-focusing and plasma defocusing effects over shallow and deep focusing inside the glass. Limits of strong and weak focusing were examined around the respective formation of low-loss optical waveguides and long uniform filament tracks. Further, we have employed the SLM for beam patterning inside thin film, exploring the limits of phase noise, resolution and fringe contrast during interferometric intra-film structuring. Femtosecond laser pulses of 200 fs pulse duration and 515 nm wavelength were shaped by a phase-only LCOS-SLM (Hamamatsu X10468-04). By imposing radial phase profiles, axicon, grating and beam splitting gratings, volume shape control of filament diameter, length, and uniformity as well as simultaneous formation of multiple filaments has been demonstrated. Similarly, competing effects of spherical surface aberration, self-focusing, and plasma de-focusing were studied and delineated to enable formation

  13. Presentation and comparison of experimental critical heat flux data at conditions prototypical of light water small modular reactors

    Energy Technology Data Exchange (ETDEWEB)

    Greenwood, M.S., E-mail: 1greenwoodms@ornl.gov; Duarte, J.P.; Corradini, M.

    2017-06-15

    Highlights: • Low mass flux and moderate to high pressure CHF experimental results are presented. • Facility uses chopped-cosine heater profile in a 2 × 2 square bundle geometry. • The EPRI, CISE-GE, and W-3 CHF correlations provide reasonable average CHF prediction. • Neural network analysis predicts experimental data and demonstrates utility of method. - Abstract: The critical heat flux (CHF) is a two-phase flow phenomenon which rapidly decreases the efficiency of the heat transfer performance at a heated surface. This phenomenon is one of the limiting criteria in the design and operation of light water reactors. Deviations of operating parameters greatly alters the CHF condition and must be experimentally determined for any new parameters such as those proposed in small modular reactors (SMR) (e.g. moderate to high pressure and low mass fluxes). Current open literature provides too little data for functional use at the proposed conditions of prototypical SMRs. This paper presents a brief summary of CHF data acquired from an experimental facility at the University of Wisconsin-Madison designed and built to study CHF at high pressure and low mass flux ranges in a 2 × 2 chopped cosine rod bundle prototypical of conceptual SMR designs. The experimental CHF test inlet conditions range from pressures of 8–16 MPa, mass fluxes of 500–1600 kg/m2 s, and inlet water subcooling from 250 to 650 kJ/kg. The experimental data is also compared against several accepted prediction methods whose application ranges are most similar to the test conditions.

  14. Deprotonation of g-C3N4 with Na ions for efficient nonsacrificial water splitting under visible light

    DEFF Research Database (Denmark)

    Guo, Feng; Chen, Jingling; Zhang, Minwei

    2016-01-01

    Developing a photocatalyst with the necessary characteristics of being cheap, efficient and robust for visible-light-driven water splitting remains a serious challenge within the photocatalysis field. Herein, an effective strategy, deprotonating g-C3N4 with Na ions from low-cost precursors...

  15. Controlled Energy Transfer from a Ligand to an Eu(III) Ion: A Unique Strategy To Obtain Bright-White-Light Emission and Its Versatile Applications.

    Science.gov (United States)

    Boddula, Rajamouli; Singh, Kasturi; Giri, Santanab; Vaidyanathan, Sivakumar

    2017-09-05

    A new diphenylamine-functionalized ancillary-ligand-coordinated europium(III) β-diketonate complex showed incomplete photoexcitation energy transfer from a ligand to a Eu(III) ion. A solvatochromism study led to a balancing of the primary colors to obtain single-molecule white-light emission. Thermal-sensing analysis of the europium complex was executed. The europium complex, conjugated with a near-UV-light-emitting diode (395 nm), showed appropriate white-light-emission CIE color coordinates (x = 0.34 and y = 0.33) with a 5152 K correlated color temperature.

  16. Experimental assessment of thermal effects of high power density light stimulation for optogenetics control of deep brain structures (Conference Presentation)

    Science.gov (United States)

    Senova, Suhan; Scisniak, Ilona; Chiang, Chih Chieh; Doignon, Isabelle; Martin, Claire; Palfi, Stephane; Chaillet, Antoine; Pain, Frederic

    2016-03-01

    2D surface maps of light distribution and temperature increase were recorded in wild type anesthetized rats brains during 90s light stimulation at 478nm (blue) and 638nm (red) with continuous or pulsed optical stimulations with corresponding power ranging from 100 up to 1200 mW/mm² at the output of an optical fiber. Post mortem maps were recorded in the same animals to assess the cooling effect of blood flow. Post mortem histological analysis were carried out to assess whether high power light stimulations had phototoxic effects or could trigger non physiological functional activation. Temperature increase remains below physiological changes (0,5 -1°) for stimulations up to 400mW/mm² at 40Hz. . Histology did not show significant irreversible modifications or damage to the tissues. The spatial profile of light distribution and heat were correlated and demonstrate as expected a rapid attenuation with diatnce to the fiber.

  17. Spatial control of in vivo optogenetic light stimulation and recording via an imaging fiber bundle (Conference Presentation)

    Science.gov (United States)

    Suárez, Javier I.; Sengupta, Parijat; Guo-Han Mun, Jonathan; Rhodes, Justin; Boppart, Stephen A.

    2017-02-01

    Light delivery in in vivo optogenetic applications are typically accomplished via a single multimode fiber that diffuses light over a large area of the brain, and relies heavily on the spatial distribution of transfected light-sensitive neurons for targeted control. In our investigations, an imaging fiber bundle (Schott, 1534702) containing 4,500 individual fibers, each with a diameter of 7.5 µm, and an overall outer bundle diameter of 530 µm, was used as the conduit for light delivery and optical recording/imaging in neuron cultures and in in vivo mouse brain. We demonstrated that the use of this fiber bundle, in contrast to a single multimode fiber, allowed for individually-addressable fibers, spatial selectivity at the stimulus site, precise control of light delivery, and full field-of-view imaging and/or optical recordings of neurons. An objective coupled the two continuous wave diode laser sources (561 nm/488 nm) for stimulation and imaging into the proximal end of the fiber bundle while a set of galvanometer-scanning mirrors was used to couple the light stimulus to distinct fibers. A micro lens aided in focusing the light at the neurons. In vivo studies utilized C1V1(E122T/E162T)-TS-p2A-mCherry (Karl Deisseroth, Stanford) and GCaMP6s transgenic mice (Jackson Labs) for this all-optical approach. Our results demonstrate that imaging fiber bundles provide superior control of spatial selectivity of light delivery to specific neurons, and function as a conduit for optical imaging and recording at the in vivo site of stimulation, in contrast to the use of single multimode fibers that diffusely illuminate tissue and lack in vivo imaging capabilities.

  18. Modeling Proton- and Light Ion-Induced Reactions at Low Energies in the MARS15 Code

    Energy Technology Data Exchange (ETDEWEB)

    Rakhno, I. L. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Mokhov, N. V. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Gudima, K. K. [National Academy of Sciences, Cisineu (Moldova)

    2015-04-25

    An implementation of both ALICE code and TENDL evaluated nuclear data library in order to describe nuclear reactions induced by low-energy projectiles in the Monte Carlo code MARS15 is presented. Comparisons between results of modeling and experimental data on reaction cross sections and secondary particle distributions are shown.

  19. Differences in neural circuitry guiding behavioral responses to polarized light presented to either the dorsal or ventral retina in Drosophila.

    Science.gov (United States)

    Velez, Mariel M; Gohl, Daryl; Clandinin, Thomas R; Wernet, Mathias F

    2014-01-01

    Linearly polarized light (POL) serves as an important cue for many animals, providing navigational information, as well as directing them toward food sources and reproduction sites. Many insects detect the celestial polarization pattern, or the linearly polarized reflections off of surfaces, such as water. Much progress has been made toward characterizing both retinal detectors and downstream circuit elements responsible for celestial POL vision in different insect species, yet much less is known about the neural basis of how polarized reflections are detected. We previously established a novel, fully automated behavioral assay for studying the spontaneous orientation response of Drosophila melanogaster populations to POL stimuli presented to either the dorsal, or the ventral halves of the retina. We identified separate retinal detectors mediating these responses: the 'Dorsal Rim Area' (DRA), which had long been implicated in celestial POL vision, as well as a previously uncharacterized 'ventral polarization area' (VPA). In this study, we investigate whether DRA and VPA use the same or different downstream circuitry, for mediating spontaneous behavioral responses. We use homozygous mutants, or molecular genetic circuit-breaking tools (silencing, as well as rescue of synaptic activity), in combination with our behavioral paradigm. We show that responses to dorsal versus ventral stimulation involve previously characterized optic lobe neurons, like lamina monopolar cell L2 and medulla cell types Dm8/Tm5c. However, using different experimental conditions, we show that important differences exist between the requirement of these cell types downstream of DRA versus VPA. Therefore, while the neural circuits underlying behavioral responses to celestial and reflected POL cues share important building blocks, these elements play different functional roles within the network.

  20. Quantificaion of ion diffusion in gallium arsenide-based spintronic Light-Emitting Diode devices using time-of-flight secondary ion mass spectrometry

    Science.gov (United States)

    Cogswell, Jeffrey Ryan

    Depth profiling using Secondary Ion Mass Spectrometry (SIMS) is a direct method to measure diffusion of atomic or molecular species that have migrated distances of nanometers/micrometers in a specific material. For this research, the diffusion of Mn, sequentially Ga ions, in Gallium Arsenide (GaAs)-based spin Light Emitting Diode (LED) devices is studied by quantitative Time-of-Flight (ToF) SIMS. The goal is to prove conclusively the driving force and mechanism behind Mn diffusion in GaAs by quantifying the diffusion of these ions in each device. Previous work has identified two competing processes for the movement of Mn in GaAs: diffusion and phase separation. The process is dependent on the temperature the sample is exposed to, either by post-annealing, or during the molecular beam epitaxy (MBE) growth process. The hypothesis is that Manganese Arsenide (MnAs) is thermodynamically more stable than randomly distributed Mn ions in GaAs, and that by annealing at a certain temperature, a pure MnAs layer can be produced from a GaMnAs layer in a working spin LED device. Secondly, the spin efficiencies will be measured and the difference will be related to the formation of a pure MnAs layer. The first chapter of this dissertation discusses the history of spintronic devices, including details on the established methods for characterization, the importance for potential application to the semiconductor industry, and the requirements for the full implementation of spintronic devices in modern-day computers. MnAs and GaMnAs devices are studied, their preparation and properties are described, and the study's experimental design is covered in the latter part of Chapter 1. Chapter 2 includes a review of diffusion in semiconductors, including the types of diffusion, mechanisms they follow, and the different established experimental methods for studying diffusion. The later sections include summaries of Mn diffusion and previous studies investigating Mn diffusion in different

  1. Surface Plasmon-Assisted Excitation of Atomic Visible Light Spectral Lines in the Impact of Highly Charged Ions 126Xeq+ on Solid Surfaces

    Institute of Scientific and Technical Information of China (English)

    张小安; 赵永涛; 李福利; 杨治虎; 肖国青; 詹文龙

    2003-01-01

    We measured the visible light spectral lines of sputtering atoms from solid surfaces of Al, Ti, Ni, Ta and Au which are impacted by 150keV126Xeq+ (6≤q≤30). It is found that intensities of the light spectral lines are greatly and suddenly enhanced when the charge state of the ion is raised up to a critical value. If assuming that potential energy released from the incidention due to capturing one electron is enough to excite a surface plasmon, we can estimate the critical charge states and obtain the results very well consistent with the measurements for the above-mentioned target materials. This means that a surface plasmon induced by one electron capture can enhance the excitation of atomic visible light spectral lines in the impact of a highly charged ion on a solid surface.

  2. Two-step flash light sintering process for enhanced adhesion between copper complex ion/silane ink and a flexible substrate

    Energy Technology Data Exchange (ETDEWEB)

    Jeon, Eun-Beom; Joo, Sung-Jun [Department of Mechanical Convergence Engineering, Hanyang University, Haengdang-dong, Seongdong-gu, Seoul 133-791 (Korea, Republic of); Ahn, Heejoon [Department of Organic and Nano Engineering, Hanyang University, Haengdang-dong, Seongdong-gu, Seoul 133-791 (Korea, Republic of); Kim, Hak-Sung, E-mail: kima@hanyang.ac.kr [Department of Mechanical Convergence Engineering, Hanyang University, Haengdang-dong, Seongdong-gu, Seoul 133-791 (Korea, Republic of); Institute of Nano Science and Technology, Hanyang University, Seoul 133-791 (Korea, Republic of)

    2016-03-31

    A copper complex ion ink (including copper nanoparticles, a copper precursor and a silane coupling agent) was synthesized to enhance the adhesion between the copper pattern and a polyimide (PI) substrate. Oxygen plasma treatment was performed on the polyimide substrate to initiate a chemical reaction between the complex ion ink and the polyimide. Then, a two-step flash light sintering method (consisting of preheating and main sintering) was used to sinter the copper complex ion ink. The copper complex ion patterns were characterized as a function of the weight fraction of silane coupling agent using scanning electron microscopy (SEM), a four-point probe method and adhesion testing. In addition, a bending fatigue test was performed to evaluate the reliability of the conductive copper pattern under cyclic bending. The copper pattern fabricated with copper complex ion ink containing 3 wt% silane coupling agent exhibited the highest adhesion level (5B), the lowest resistivity (7.6 μΩ·cm) and a low resistance change (18%) after the bending fatigue test. The two-step sintering method used to enhance the adhesion between the copper complex ion ink and polyimide substrate was also studied using X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FT-IR). - Highlights: • The copper complex ion ink with copper nanoparticles and copper precursor was fabricated. • The copper complex ion ink was sintered by two-step flash light sintering method. • The sintered copper pattern exhibited the highest adhesion level (5B). • The resistivity of sintered copper pattern was 7.6 μΩ·cm.

  3. Designing an upgrade of the Medley setup for light-ion production and fission cross-section measurements

    CERN Document Server

    Jansson, Kaj; Al-Adili, Ali; Hjalmarsson, Anders; Andersson-Sundén, Erik; Prokofiev, Alexander V; Tarrío, Diego; Pomp, Stephan

    2015-01-01

    Measurements of neutron-induced fission cross sections and light-ion production are planned in the energy range 1-40 MeV at the upcoming Neutrons For Science (NFS) facility. In order to prepare our detector setup for the neutron beam with continuous energy spectrum, a simulation software was written using the Geant4 toolkit for both measurement situations. The neutron energy range around 20 MeV is troublesome when it comes to the cross sections used by Geant4 since data-driven cross sections are only available below 20 MeV but not above, where they are based on semi-empirical models. Several customisations were made to the standard classes in Geant4 in order to produce consistent results over the whole simulated energy range. Expected uncertainties are reported for both types of measurements. The simulations have shown that a simultaneous precision measurement of the three standard cross sections H(n,n), $^{235}$U(n,f) and $^{238}$U(n,f) relative to each other is feasible using a triple layered target. As hig...

  4. Observation of intermediate bands in Eu3+ doped YPO4 host: Li+ ion effect and blue to pink light emitter

    Directory of Open Access Journals (Sweden)

    Abdul Kareem Parchur

    2012-09-01

    Full Text Available This article explores the tuning of blue to pink colour generation from Li+ ion co-doped YPO4:5Eu nanoparticles prepared by polyol method at ∼100-120 °C with ethylene glycol (EG as a capping agent. Interaction of EG molecules capped on the surface of the nanoparticles and/or created oxygen vacancies induces formation of intermediate/mid gap bands in the host structure, which is supported by UV-Visible absorption data. Strong blue and pink colors can be observed in the cases of as-prepared and 500 °C annealed samples, respectively. Co-doping of Li+ enhances the emission intensities of intermediate band as well as Eu3+. On annealing as-prepared sample to 500 °C, the intermediate band emission intensity decreases, whereas Eu3+ emission intensity increases suggesting increase of extent of energy transfer from the intermediate band to Eu3+ on annealing. Emission intensity ratio of electric to magnetic dipole transitions of Eu3+ can be varied by changing excitation wavelength. The X-ray photoelectron spectroscopy (XPS study of as-prepared samples confirms the presence of oxygen vacancies and Eu3+ but absence of Eu2+. Dispersed particles in ethanol and polymer film show the strong blue color, suggesting that these materials will be useful as probes in life science and also in light emitting device applications.

  5. Nuclear recoil corrections to the Lamb shift of hydrogen and light hydrogenlike ions

    Science.gov (United States)

    Yerokhin, V. A.; Shabaev, V. M.

    2016-06-01

    Accurate calculations of the nuclear recoil effect on the Lamb shift of hydrogenlike atoms are presented. Numerical results are reported for the n s states with n ≤5 and for the 2 p1 /2 and 2 p3 /2 states. The calculations are performed to the first order in the electron-nucleus mass ratio and to all orders in the nuclear binding strength parameter Z α (where Z is the nuclear charge number and α is the fine structure constant). The obtained results provide accurate predictions for the higher-order remainder beyond the known Z α -expansion terms. In the case of hydrogen, the remainder was found to be much larger than anticipated. This result resolves the previously reported disagreement between the numerical all-order and the analytical Z α -expansion approaches for the nuclear recoil effect on the hydrogen Lamb shift.

  6. Nuclear recoil corrections to the Lamb shift of hydrogen and light hydrogen-like ions

    CERN Document Server

    Yerokhin, V A

    2016-01-01

    Accurate calculations of the nuclear recoil effect to the Lamb shift of hydrogen-like atoms are presented. Numerical results are reported for the $ns$ states with $n \\leq 5$ and for the $2p_{1/2}$ and $2p_{3/2}$ states. The calculations are performed to the first order in the electron-nucleus mass ratio and to all orders in the nuclear binding strength parameter $Z\\alpha$ (where $Z$ is the nuclear charge number and $\\alpha$ is the fine structure constant). The obtained results provide accurate predictions for the higher-order remainder beyond the known $Z\\alpha$-expansion terms. In the case of hydrogen, the remainder was found to be much larger than anticipated. This result resolves the previously reported disagreement between the numerical all-order and the analytical $Z\\alpha$-expansion approaches for the nuclear recoil effect in the hydrogen Lamb shift.

  7. Antiradiation Vaccine: Technology Development- Radiation Tolerance,Prophylaxis, Prevention And Treatment Of Clinical Presentation After Heavy Ion Irradiation.

    Science.gov (United States)

    Popov, Dmitri; Maliev, Slava; Jones, Jeffrey

    Introduction: Research in the field of biological effects of heavy charged particles is necessary for both heavy-ion therapy (hadrontherapy) and protection from the exposure to galactic cosmic radiation in long-term manned space missions.[Durante M. 2004] In future crew of long-term manned missions could operate in exremely high hadronic radiation areas of space and will not survive without effective radiation protection. An Antiradiation Vaccine (AV) must be an important part of a countermeasures regimen for efficient radiation protection purposes of austronauts-cosmonauts-taukonauts: immune-prophylaxis and immune-therapy of acute radiation toxic syndromes developed after heavy ion irradiation. New technology developed (AV) for the purposes of radiological protection and improvement of radiation tolerance and it is quite important to create protective immune active status which prevent toxic reactions inside a human body irradiated by high energy hadrons.[Maliev V. et al. 2006, Popov D. et al.2008]. High energy hadrons produce a variety of secondary particles which play an important role in the energy deposition process, and characterise their radiation qualities [Sato T. et al. 2003] Antiradiation Vaccine with specific immune-prophylaxis by an anti-radiation vaccine should be an important part of medical management for long term space missions. Methods and experiments: 1. Antiradiation vaccine preparation standard, mixture of toxoid form of Radiation Toxins [SRD-group] which include Cerebrovascular RT Neurotoxin, Cardiovascular RT Neurotoxin, Gastrointestinal RT Neurotoxin, Hematopoietic RT Hematotoxin. Radiation Toxins of Radiation Determinant Group isolated from the central lymph of gamma-irradiated animals with Cerebrovascular, Cardiovascular, Gastro-intestinal, Hematopoietic forms of ARS. Devices for radiation are "Panorama", "Puma". 2. Heavy ion exposure was accomplished at Department of Research Institute of Nuclear Physics, Dubna, Russia. The heavy ions

  8. Motorway lighting under fog conditions : based on a paper presented at Japan Highway Corporation, Tokyo, 12 July 1990.

    NARCIS (Netherlands)

    Schreuder, D.A.

    1992-01-01

    This study defines fog as an aerosol consisting primarily of water droplets. The main effect on road traffic is the contrast reduction as a result of the scatter of light in the aerosol. Absorption plays only a small role. The effect of the contrast reduction is that many objects in the field of vie

  9. Motorway lighting under fog conditions : based on a paper presented at Japan Highway Corporation, Tokyo, 12 July 1990.

    NARCIS (Netherlands)

    Schreuder, D.A.

    1992-01-01

    This study defines fog as an aerosol consisting primarily of water droplets. The main effect on road traffic is the contrast reduction as a result of the scatter of light in the aerosol. Absorption plays only a small role. The effect of the contrast reduction is that many objects in the field of vie

  10. Production of multicharged iron and nitrogen ions and application to enhance photo-catalytic performance in visible light region on TiO{sub 2} thin films

    Energy Technology Data Exchange (ETDEWEB)

    Kato, Yushi [Department of Electronics and Informatics, Toyama Prefectural University 5180 Kurokawa, Kosugi, Toyama 939-0398 (Japan)]. E-mail: kato@eie.eng.osaka-u.ac.jp; Yoshinaga, Takashi [Department of Electronics and Informatics, Toyama Prefectural University 5180 Kurokawa, Kosugi, Toyama 939-0398 (Japan); Tomida, Masashi [Department of Electronics and Informatics, Toyama Prefectural University 5180 Kurokawa, Kosugi, Toyama 939-0398 (Japan); Kimpara, Shinichiro [Department of Electronics and Informatics, Toyama Prefectural University 5180 Kurokawa, Kosugi, Toyama 939-0398 (Japan)

    2005-08-01

    Multicharged iron and nitrogen ions have been produced from solid materials in a 2.45 GHz electron cyclotron resonance (ECR) ion source (TAIKO device, Toyama Prefectural University), and also large area TiO{sub 2} thin films are individually produced by reactive sputtering in an arched ECR plasma. We normally form the TiO{sub 2} thin film ({approx}100 nm) on the Si(1 0 0) substrates. We measure the X-ray diffraction for characterization of the TiO{sub 2} crystallinity and the contact angle of distilled water for estimation of photo-catalytic performance. The crystalline TiO{sub 2} thin films are anatase and rutile phases. Fe{sup 3+} and N{sup 3+} ions were implanted into TiO{sub 2} thin films on the Si substrates in order to enhance photo-catalytic performance in visible light region. The maximum efficiency of photo-catalytic performance has been obtained at the dose of about 2 x 10{sup 15} cm{sup -2}. We compared contact angles of distilled water on the TiO{sub 2} by illuminating fluorescent light for four hours before and after implantation. Photo-catalytic performance of the TiO{sub 2} thin film in visible light region after implantation is better than that before implantation without deterioration in ultraviolet light region.

  11. Nano Structure Plays an Important Role in the Present and Future Anode Materials of Li-ion Batteries

    Institute of Scientific and Technical Information of China (English)

    Tsutomu; Takamura

    2007-01-01

    1 ResultsLi-ion batteries are the most promising secondary batteries for IT and EV applications, where it is required to increase the capacity and power capability to a great extent. In responding to the demand we have been studied on the anode materials especially paying attention on the improved graphite active materials and modified silicon. In both cases we realized that the nano-structured design plays an important role. In this paper the examples of nano-size structure working in the actual materi...

  12. Characterization of carbon contamination under ion and hot atom bombardment in a tin-plasma extreme ultraviolet light source

    Energy Technology Data Exchange (ETDEWEB)

    Dolgov, A., E-mail: a.dolgov@utwente.nl [MESA+ Institute for Nanotechnology, University of Twente, Enschede (Netherlands); Lopaev, D. [Skobeltsyn Institute of Nuclear Physics, Moscow State University, Moscow (Russian Federation); Lee, C.J. [MESA+ Institute for Nanotechnology, University of Twente, Enschede (Netherlands); Zoethout, E. [Dutch Institute for Fundamental Energy Research (DIFFER), Nieuwegein (Netherlands); Medvedev, V. [MESA+ Institute for Nanotechnology, University of Twente, Enschede (Netherlands); Yakushev, O. [Institute for Spectroscopy Russian Academy of Sciences, Moscow (Russian Federation); Bijkerk, F. [MESA+ Institute for Nanotechnology, University of Twente, Enschede (Netherlands)

    2015-10-30

    Highlights: • Carbon film grown during exposure to EUV radiation and high energy ions was studied. • The carbon film is highly resistant to chemical and physical sputtering. • Surface contamination of plasma-facing components is similar to hydrogenated DLC. - Abstract: Molecular contamination of a grazing incidence collector for extreme ultraviolet (EUV) lithography was experimentally studied. A carbon film was found to have grown under irradiation from a pulsed tin plasma discharge. Our studies show that the film is chemically inert and has characteristics that are typical for a hydrogenated amorphous carbon film. It was experimentally observed that the film consists of carbon (∼70 at.%), oxygen (∼20 at.%) and hydrogen (bound to oxygen and carbon), along with a few at.% of tin. Most of the oxygen and hydrogen are most likely present as OH groups, chemically bound to carbon, indicating an important role for adsorbed water during the film formation process. It was observed that the film is predominantly sp{sup 3} hybridized carbon, as is typical for diamond-like carbon. The Raman spectra of the film, under 514 and 264 nm excitation, are typical for hydrogenated diamond-like carbon. Additionally, the lower etch rate and higher energy threshold in chemical ion sputtering in H{sub 2} plasma, compared to magnetron-sputtered carbon films, suggests that the film exhibits diamond-like carbon properties.

  13. Water fragmentation by bare and dressed light ions with MeV energies: Fragment-ion-energy and time-of-flight distributions

    Science.gov (United States)

    Wolff, W.; Luna, H.; Schuch, R.; Cariatore, N. D.; Otranto, S.; Turco, F.; Fregenal, D.; Bernardi, G.; Suárez, S.

    2016-08-01

    The energy and time-of-flight distributions of water ionic fragments produced by impact of fast atoms and bare and dressed ions; namely, H+, Li0 -3 +, C1 +, and C2 + are reported in this work. Fragment species as a function of emission energy and time-of-flight were recorded by using an electrostatic spectrometer and a time-of-flight mass spectrometer, respectively. An improved Coulomb explosion model coupled to a classical trajectory Monte Carlo (CTMC) simulation gave the energy centroids of the fragments for the dissociation channels resulting from the removal of two to five electrons from the water molecule. For the energy distribution ranging up to 50 eV, both the experiment and model reveal an isotropic production of multiple charged oxygen ions, as well as hydrogen ions. From the ion energy distribution, relative yields of the dissociation resulting from multiple ionization were obtained as a function of the charge state, as well as for several projectile energies. Multiple-ionization yields with charge state up to 4+, were extracted from the measurements of the time-of-flight spectra, focused on the production of single and multiple charged oxygen ions. The measurements were compared to ion-water collision experiments investigated at the keV energy range available in the literature, revealing differences and similarities in the fragment-ion energy distribution.

  14. Jan Rak and Michael J. Tannenbaum present the book "High-pT physics in the heavy ion era"

    CERN Multimedia

    2013-01-01

    Thursday 13 June 2013 from 4 p.m. to 5 p.m. in the Library, Bldg. 52 1-052 The book provides an overview of the basic concepts of large transverse momentum particle physics, with a focus on pQCD phenomena. It examines high-pT probes of relativistic heavy-ion collisions and will serve as a handbook for those working on RHIC and LHC data analyses. Starting with an introduction and review of the field, the authors look at basic observables and experimental techniques, concentrating on relativistic particle kinematics, before moving onto a discussion about the origins of high-pT physics. The main features of high-pT physics are placed within a historical context and the authors adopt an experimental outlook, highlighting the most important discoveries leading up to the foundation of modern QCD theory. High-pT physics in the heavy ion era, by Jan Rak and Michael J. Tannenbaum,  Cambridge University Press, 2013, ISBN  9780521190299. *Coffee will be served from 3 p.m.*

  15. Effect of Organic Solvents and Biologically Relevant Ions on the Light-Induced DNA Cleavage by Pyrene and Its Amino and Hydroxy Derivatives

    Directory of Open Access Journals (Sweden)

    Hongtao Yu

    2002-09-01

    Full Text Available Abstract: Polycyclic aromatic hydrocarbons (PAHs are a class of carcinogenic compounds that are both naturally and artificially produced. Many PAHs are pro-carcinogens that require metabolic activation. Recently, it has been shown that PAH can induce DNA single strand cleavage and formation of PAH-DNA covalent adduct upon irradiation with UVA light. The light-induced DNA cleavage parallels phototoxicity in one instance. The DNA photocleavage efficiency depends on the structure of the PAHs. This article reports the effect of both organic solvents and the presence of biologically relevant ions, Na+, Mg2+, Ca2+, K+, Fe3+, Cu2+, Zn+2, Mn2+, and I-, on the light-induced DNA cleavage by pyrene, 1-hydroxypyrene and 1-aminopyrene. Since both 1-hydroxypyrene (0.6 μM and 1-aminopyrene (6 μM dissolve well in the minimum organic solvents used (2% methanol, dimethylsulfoxide, and dimethylformamide, increasing the amount of the organic solvent resulted in the decrease of the amount of DNA single strand cleavage caused by the combination effect of 1-hydroxy or 1-aminopyrene and UVA light. The result with the less watersoluble pyrene shows that increase of the amount of the organic solvent can increase the amount of DNA single strand DNA photocleavage cause by the combination of pyrene and UVA light. Therefore, there are two effects by the organic solvents: (i to dissolve PAH and (ii to quench DNA photocleavage. The presence of Fe3+ and Zn2+ enhances, while the presence of Ca2+ and Mn2+ inhibits the DNA photocleavage caused by 1-aminopyrene and UVA light. Other metal ions have minimal effect. This means that the effect of ions on DNA photocleavage by PAHs is complex. The presence of KI enhances DNA photocleavage. This indicates that the triplet-excited state of 1-aminopyrene is involved in causing DNA cleavage

  16. Slow and fast light via two-wave mixing in the rare-earth doped optical fibers (Conference Presentation)

    Science.gov (United States)

    Stepanov, Serguei I.; Plata Sánchez, Marcos; Hernández, Eliseo

    2017-02-01

    Dynamic population Bragg gratings can be recorded in the rare-earth-doped (e.g. doped with erbium or ytterbium) optical fibers with mWatt-scale cw laser power. Two-wave mixing (TWM) via such gratings is utilized in single-frequency fiber lasers and in adaptive interferometric fiber sensors with automatic stabilization of the operation point. Slow and fast light propagation can also be observed in the vicinity of narrow ( 20-200Hz) spectral profile of stationary no-degenerate TWM. In particular, slow light propagation is observed for the purely amplitude grating, recorded in the erbium-doped fiber in spectral range 1510-1550nm. In its turn, in ytterbium-doped fibers at 1064nm (or in erbium-doped fiber at the wavelength below 1500nm) the dynamic grating has significant contribution of the phase component, the TWM profile has essentially asymmetric form, and both slow and fast (superluminal) light propagation is possible at different frequency off-sets between the counter-propagating interacting waves.

  17. Light Particle Emission Mechanisms in Heavy-Ion Reactions at 5-20 MeV/u

    Directory of Open Access Journals (Sweden)

    Fotina O.V.

    2010-03-01

    Full Text Available Light Charged Particle emission mechanisms were studied for different mass entrance channel nuclear reactions. The 300, 400, 500 MeV 64Ni + 68Zn and 130, 250 MeV 16O + 116Sn reactions were measured at the Legnaro National Laboratory using the beams from the TANDEM-ALPI acceleration system. Light Charged Particles were measured in coincidence with Evaporation Residues and their spectra were analyzed using the global moving source fit technique. The characterization of different emission sources (evaporative, pre-equilibrium, break-up is discussed. The behavior of pre-equilibrium emission as a function of projectile energy, excitation energy and mass-asymmetry in the entrance channel was studied, evaluating the energy, mass and charge lost by the composite systems and using Griffin exciton model for the pre-equilibrium neutron emission. The present results are compared with the systematics of the asymmetric mass entrance channel reactions. The present work shows that also at the onset the pre-equilibrium emission depends not only on the projectile velocity but also on the reaction entrance channel mass-asymmetry. The first attempt of the particle spectra analysis using the Griffin exciton model is demonstrated for the case of proton emission in the 130 MeV 16O + 116Sn reaction.

  18. Stable luminescent metal-organic frameworks as dual-functional materials to encapsulate ln(3+) ions for white-light emission and to detect nitroaromatic explosives.

    Science.gov (United States)

    Xie, Wei; Zhang, Shu-Ran; Du, Dong-Ying; Qin, Jun-Sheng; Bao, Shao-Juan; Li, Jing; Su, Zhong-Min; He, Wen-Wen; Fu, Qiang; Lan, Ya-Qian

    2015-04-06

    A stable porous carbazole-based luminescent metal-organic framework, NENU-522, was successfully constructed. It is extremely stable in air and acidic/basic aqueous solutions, which provides the strategy for luminescent material encapsulation of Ln(3+) ions with tunable luminescence for application in light emission. More importantly, Ln(3+)@NENU-522 can emit white light by encapsulating different molar ratios of Eu(3+) and Tb(3+) ions. Additionally, Tb(3+)@NENU-522 is found to be useful as a fluorescent indicator for the qualitative and quantitative detection of nitroaromatic explosives with different numbers of -NO2 groups, and the concentrations of complete quenching are about 2000, 1000, and 80 ppm for nitrobenzene, 1,3-dinitrobenzene, and 2,4,6-trinitrophenol, respectively. Meanwhile, Tb(3+)@NENU-522 displays high selectivity and recyclability in the detection of nitroaromatic explosives.

  19. Enhancing visible light photocatalytic and photocharge separation of (BiO){sub 2}CO{sub 3} plate via dramatic I{sup −} ions doping effect

    Energy Technology Data Exchange (ETDEWEB)

    Liang, Lei [College of Chemistry and Materials Science, Huaibei Normal University, Huaibei, 235000, Anhui (China); Cao, Jing [College of Chemistry and Materials Science, Huaibei Normal University, Huaibei, 235000, Anhui (China); Anhui Collaborative Innovation Center of Advanced Functional Composite, Huaibei, 235000, Anhui (China); Lin, Haili, E-mail: linhaili@mail.ipc.ac.cn [College of Chemistry and Materials Science, Huaibei Normal University, Huaibei, 235000, Anhui (China); Guo, Xiaomin; Zhang, Meiyu [College of Chemistry and Materials Science, Huaibei Normal University, Huaibei, 235000, Anhui (China); Chen, Shifu, E-mail: chshifu@chnu.edu.cn [College of Chemistry and Materials Science, Huaibei Normal University, Huaibei, 235000, Anhui (China); College of Chemistry and Materials Engineering, Anhui Science and Technology University, Fengyang, 233100, Anhui (China)

    2016-08-15

    Highlights: • Novel I-(BiO){sub 2}CO{sub 3} was prepared by a facile chemical precipitation method. • I{sup −} ions impurity level located on the top of valence band of (BiO){sub 2}CO{sub 3}. • I{sup −} ions doping largely improved photocatalytic activity of I-(BiO){sub 2}CO{sub 3}. • I-(BiO){sub 2}CO{sub 3} displayed excellent photocharge separation efficiency. - Abstract: Novel I{sup −} ions doped (BiO){sub 2}CO{sub 3} (I-(BiO){sub 2}CO{sub 3}) photocatalysts were successfully synthesized via a facile chemical precipitation method. Under visible light (λ > 400 nm), I-(BiO){sub 2}CO{sub 3} displayed much higher activity for rhodamine B and dichlorophenol degradation than the undoped (BiO){sub 2}CO{sub 3}. The pseudo-first-order rate constant k{sub app} of RhB degradation over 15.0% I-(BiO){sub 2}CO{sub 3} was 0.54 h{sup −1}, which is 11.3 times higher than that of (BiO){sub 2}CO{sub 3}. The doped I{sup −} ions formed an impurity level on the top of valence band of (BiO){sub 2}CO{sub 3} and induced much more visible light to be absorbed. The enhanced photocurrent and surface photovoltage properties were detected, which strongly ensures the efficient separation of electrons and holes in I-(BiO){sub 2}CO{sub 3} system under visible light. It provides a facile way to improve the photocatalytic activity of the wide-band-gap (BiO){sub 2}CO{sub 3} via intense doping effect of I{sup −} ions.

  20. Light propagation through random hyperbolic media: from a pile of sand to large scale structure of present day universe

    CERN Document Server

    Smolyaninov, Igor I

    2012-01-01

    We analyze electromagnetic field propagation through a random medium which consists of hyperbolic metamaterial domains separated by regions of normal "elliptic" space. This situation may occur in a problem as common as 9 micrometer light propagation through a pile of sand, or as exotic as electromagnetic field behavior in the early universe immediately after the electro-weak phase transition. We demonstrate that spatial field distributions in random hyperbolic and random "elliptic" media look strikingly different. This effect may potentially be used to evaluate the magnitude of magnetic fields which existed in the early universe.

  1. Eu{sup 3+} ions co-doped CLPO: Dy{sup 3+} single phase white-light emitting phosphors for near UV-based white LEDs

    Energy Technology Data Exchange (ETDEWEB)

    Jeon, Yong Il; Bharat, L. Krishna; Yu, Jae Su, E-mail: jsyu@khu.ac.kr

    2015-11-15

    CaLaP{sub 3}O{sub 10}: Dy{sup 3+}/Eu{sup 3+} phosphor powders were prepared by a facile sol–gel method. These samples were thermally treated at 900 °C for 6 h to get monazite type structure with monoclinic unit cell. The phase, morphology and optical properties of phosphor samples were characterized by X-ray diffraction patterns, Fourier transform infrared spectra, scanning/transmission electron microscope images, and photoluminescence excitation and emission spectra. The Dy{sup 3+}/Eu{sup 3+} ions co-doped samples showed warm white-light emissions with lower correlated color temperature values at higher Eu{sup 3+} ion concentrations. The near-ultraviolet (NUV) excitation and the effective energy transfer form Dy{sup 3+} to Eu{sup 3+} ions can make these phosphors as potential candidates for NUV excitation based white light-emitting diodes. - Highlights: • Single crystalline CLPO phosphors were successfully prepared by a sol–gel process. • CLPO has monazite type structure with monoclinic unit cells. • Eu{sup 3+} co-doped CLPO: Dy{sup 3+} samples give warm white-light emission with low CCT values. • The NUV excitation (392 nm) allows the use of this material for WLED applications.

  2. On-chip high-power porous silicon lithium ion batteries with stable capacity over 10000 cycles (Presentation Recording)

    Science.gov (United States)

    Westover, Andrew S.; Freudiger, Daniel; Gani, Zarif; Share, Keith; Oakes, Landon; Carter, Rachel E.; Pint, Cary L.

    2015-09-01

    We demonstrate the operation of a graphene-passivated on-chip porous silicon material as a high rate lithium ion battery anode with over 50x power density and 100x energy density improvement compared to identically prepared on-chip porous silicon supercapacitors. We demonstrate this Faradaic storage behavior to occur at fast charging rates (1-10 mA/cm2) where lithium locally intercalates into the nanoporous silicon, but not underlying bulk silicon material. This prevents the degradation and poor cycling performance that is commonly observed from deep storage in bulk silicon materials. As a result, this device exhibits cycling performance that exceeds 10,000 cycles with capacity above 0.1 mAh/cm2, without notable capacity fade. This work demonstrates a practical route toward high power, high energy, and long lifetime all-silicon on-chip storage systems relevant toward integration of energy storage into electronics, photovoltaics, and other silicon-based technology.

  3. Light-induced changes in hydrogen, calcium, potassium, and chloride ion fluxes and concentrations from the mesophyll and epidermal tissues of bean leaves. Understanding the ionic basis of light-induced bioelectrogenesis

    Science.gov (United States)

    Shabala; Newman

    1999-03-01

    Noninvasive, ion-selective vibrating microelectrodes were used to measure the kinetics of H+, Ca2+, K+, and Cl- fluxes and the changes in their concentrations caused by illumination near the mesophyll and attached epidermis of bean (Vicia faba L.). These flux measurements were related to light-induced changes in the plasma membrane potential. The influx of Ca2+ was the main depolarizing agent in electrical responses to light in the mesophyll. Changes in the net fluxes of H+, K+, and Cl- occurred only after a significant delay of about 2 min, whereas light-stimulated influx of Ca2+ began within the time resolution of our measurements (5 s). In the absence of H+ flux, light caused an initial quick rise of external pH near the mesophyll and epidermal tissues. In the mesophyll this fast alkalinization was followed by slower, oscillatory pH changes (5-15 min); in the epidermis the external pH increased steadily and reached a plateau 3 min later. We explain the initial alkalinization of the medium as a result of CO2 uptake by photosynthesizing tissue, whereas activation of the plasma membrane H+ pump occurred 1.5 to 2 min later. The epidermal layer seems to be a substantial barrier for ion fluxes but not for CO2 diffusion into the leaf.

  4. Light-Induced Changes in Hydrogen, Calcium, Potassium, and Chloride Ion Fluxes and Concentrations from the Mesophyll and Epidermal Tissues of Bean Leaves. Understanding the Ionic Basis of Light-Induced Bioelectrogenesis1

    Science.gov (United States)

    Shabala, Sergey; Newman, Ian

    1999-01-01

    Noninvasive, ion-selective vibrating microelectrodes were used to measure the kinetics of H+, Ca2+, K+, and Cl− fluxes and the changes in their concentrations caused by illumination near the mesophyll and attached epidermis of bean (Vicia faba L.). These flux measurements were related to light-induced changes in the plasma membrane potential. The influx of Ca2+ was the main depolarizing agent in electrical responses to light in the mesophyll. Changes in the net fluxes of H+, K+, and Cl− occurred only after a significant delay of about 2 min, whereas light-stimulated influx of Ca2+ began within the time resolution of our measurements (5 s). In the absence of H+ flux, light caused an initial quick rise of external pH near the mesophyll and epidermal tissues. In the mesophyll this fast alkalinization was followed by slower, oscillatory pH changes (5–15 min); in the epidermis the external pH increased steadily and reached a plateau 3 min later. We explain the initial alkalinization of the medium as a result of CO2 uptake by photosynthesizing tissue, whereas activation of the plasma membrane H+ pump occurred 1.5 to 2 min later. The epidermal layer seems to be a substantial barrier for ion fluxes but not for CO2 diffusion into the leaf. PMID:10069851

  5. Relativistically Induced Transparency Acceleration (RITA) of Protons and Light-ions with Ultrashort Laser Interaction with Heavy-ion Plasma Density Gradient

    CERN Document Server

    Sahai, Aakash A; Tableman, A R; Mori, W B; Katsouleas, T C

    2014-01-01

    The relativistically induced transparency acceleration (RITA) scheme of proton and ion acceleration using laser-plasma interactions is introduced, modeled, and compared to the existing schemes. Protons are accelerated with femtosecond relativistic pulses to produce quasimonoenergetic bunches with controllable peak energy. The RITA scheme works by a relativistic laser inducing transparency to densities higher than the cold-electron critical density, while the background heavy ions are stationary. The rising laser pulse creates a traveling acceleration structure at the relativistic critical density by ponderomotively driving a local electron density inflation, creating an electron snowplow and a co-propagating electrostatic potential. The snowplow advances with a velocity determined by the rate of the rise of the laser's intensity envelope and the heavy-ion-plasma density gradient scale length. The rising laser is incrementally rendered transparent to higher densities such that the relativistic-electron plasma ...

  6. Measurement of elliptic flow of light nuclei at √{sN N}=200 , 62.4, 39, 27, 19.6, 11.5, and 7.7 GeV at the BNL Relativistic Heavy Ion Collider

    Science.gov (United States)

    Adamczyk, L.; Adkins, J. K.; Agakishiev, G.; Aggarwal, M. M.; Ahammed, Z.; Alekseev, I.; Aparin, A.; Arkhipkin, D.; Aschenauer, E. C.; Attri, A.; Averichev, G. S.; Bai, X.; Bairathi, V.; Bellwied, R.; Bhasin, A.; Bhati, A. K.; Bhattarai, P.; Bielcik, J.; Bielcikova, J.; Bland, L. C.; Bordyuzhin, I. G.; Bouchet, J.; Brandenburg, J. D.; Brandin, A. V.; Bunzarov, I.; Butterworth, J.; Caines, H.; Calderón de la Barca Sánchez, M.; Campbell, J. M.; Cebra, D.; Chakaberia, I.; Chaloupka, P.; Chang, Z.; Chatterjee, A.; Chattopadhyay, S.; Chen, J. H.; Chen, X.; Cheng, J.; Cherney, M.; Christie, W.; Contin, G.; Crawford, H. J.; Das, S.; De Silva, L. C.; Debbe, R. R.; Dedovich, T. G.; Deng, J.; Derevschikov, A. A.; di Ruzza, B.; Didenko, L.; Dilks, C.; Dong, X.; Drachenberg, J. L.; Draper, J. E.; Du, C. M.; Dunkelberger, L. E.; Dunlop, J. C.; Efimov, L. G.; Engelage, J.; Eppley, G.; Esha, R.; Evdokimov, O.; Eyser, O.; Fatemi, R.; Fazio, S.; Federic, P.; Fedorisin, J.; Feng, Z.; Filip, P.; Fisyak, Y.; Flores, C. E.; Fulek, L.; Gagliardi, C. A.; Garand, D.; Geurts, F.; Gibson, A.; Girard, M.; Greiner, L.; Grosnick, D.; Gunarathne, D. S.; Guo, Y.; Gupta, S.; Gupta, A.; Guryn, W.; Hamad, A. I.; Hamed, A.; Haque, R.; Harris, J. W.; He, L.; Heppelmann, S.; Heppelmann, S.; Hirsch, A.; Hoffmann, G. W.; Horvat, S.; Huang, T.; Huang, X.; Huang, B.; Huang, H. Z.; Huck, P.; Humanic, T. J.; Igo, G.; Jacobs, W. W.; Jang, H.; Jentsch, A.; Jia, J.; Jiang, K.; Judd, E. G.; Kabana, S.; Kalinkin, D.; Kang, K.; Kauder, K.; Ke, H. W.; Keane, D.; Kechechyan, A.; Khan, Z. H.; Kikoła, D. P.; Kisel, I.; Kisiel, A.; Kochenda, L.; Koetke, D. D.; Kosarzewski, L. K.; Kraishan, A. F.; Kravtsov, P.; Krueger, K.; Kumar, L.; Lamont, M. A. C.; Landgraf, J. M.; Landry, K. D.; Lauret, J.; Lebedev, A.; Lednicky, R.; Lee, J. H.; Li, X.; Li, C.; Li, X.; Li, Y.; Li, W.; Lin, T.; Lisa, M. A.; Liu, F.; Ljubicic, T.; Llope, W. J.; Lomnitz, M.; Longacre, R. S.; Luo, X.; Ma, R.; Ma, G. L.; Ma, Y. G.; Ma, L.; Magdy, N.; Majka, R.; Manion, A.; Margetis, S.; Markert, C.; Matis, H. S.; McDonald, D.; McKinzie, S.; Meehan, K.; Mei, J. C.; Minaev, N. G.; Mioduszewski, S.; Mishra, D.; Mohanty, B.; Mondal, M. M.; Morozov, D. A.; Mustafa, M. K.; Nandi, B. K.; Nasim, Md.; Nayak, T. K.; Nigmatkulov, G.; Niida, T.; Nogach, L. V.; Noh, S. Y.; Novak, J.; Nurushev, S. B.; Odyniec, G.; Ogawa, A.; Oh, K.; Okorokov, V. A.; Olvitt, D.; Page, B. S.; Pak, R.; Pan, Y. X.; Pandit, Y.; Panebratsev, Y.; Pawlik, B.; Pei, H.; Perkins, C.; Pile, P.; Pluta, J.; Poniatowska, K.; Porter, J.; Posik, M.; Poskanzer, A. M.; Pruthi, N. K.; Putschke, J.; Qiu, H.; Quintero, A.; Ramachandran, S.; Raniwala, R.; Raniwala, S.; Ray, R. L.; Ritter, H. G.; Roberts, J. B.; Rogachevskiy, O. V.; Romero, J. L.; Ruan, L.; Rusnak, J.; Rusnakova, O.; Sahoo, N. R.; Sahu, P. K.; Sakrejda, I.; Salur, S.; Sandweiss, J.; Sarkar, A.; Schambach, J.; Scharenberg, R. P.; Schmah, A. M.; Schmidke, W. B.; Schmitz, N.; Seger, J.; Seyboth, P.; Shah, N.; Shahaliev, E.; Shanmuganathan, P. V.; Shao, M.; Sharma, M. K.; Sharma, B.; Shen, W. Q.; Shi, Z.; Shi, S. S.; Shou, Q. Y.; Sichtermann, E. P.; Sikora, R.; Simko, M.; Singha, S.; Skoby, M. J.; Smirnov, N.; Smirnov, D.; Solyst, W.; Song, L.; Sorensen, P.; Spinka, H. M.; Srivastava, B.; Stanislaus, T. D. S.; Stepanov, M.; Stock, R.; Strikhanov, M.; Stringfellow, B.; Sumbera, M.; Summa, B.; Sun, X. M.; Sun, Z.; Sun, Y.; Surrow, B.; Svirida, D. N.; Tang, Z.; Tang, A. H.; Tarnowsky, T.; Tawfik, A.; Thäder, J.; Thomas, J. H.; Timmins, A. R.; Tlusty, D.; Todoroki, T.; Tokarev, M.; Trentalange, S.; Tribble, R. E.; Tribedy, P.; Tripathy, S. K.; Tsai, O. D.; Ullrich, T.; Underwood, D. G.; Upsal, I.; Van Buren, G.; van Nieuwenhuizen, G.; Vandenbroucke, M.; Varma, R.; Vasiliev, A. N.; Vertesi, R.; Videbæk, F.; Vokal, S.; Voloshin, S. A.; Vossen, A.; Wang, Y.; Wang, G.; Wang, J. S.; Wang, H.; Wang, Y.; Wang, F.; Webb, G.; Webb, J. C.; Wen, L.; Westfall, G. D.; Wieman, H.; Wissink, S. W.; Witt, R.; Wu, Y.; Xiao, Z. G.; Xie, W.; Xie, G.; Xin, K.; Xu, H.; Xu, Z.; Xu, J.; Xu, Y. F.; Xu, Q. H.; Xu, N.; Yang, Y.; Yang, S.; Yang, C.; Yang, Y.; Yang, Y.; Yang, Q.; Ye, Z.; Ye, Z.; Yepes, P.; Yi, L.; Yip, K.; Yoo, I.-K.; Yu, N.; Zbroszczyk, H.; Zha, W.; Zhang, J.; Zhang, Y.; Zhang, X. P.; Zhang, Z.; Zhang, J. B.; Zhang, S.; Zhang, S.; Zhang, J.; Zhao, J.; Zhong, C.; Zhou, L.; Zhu, X.; Zoulkarneeva, Y.; Zyzak, M.; STAR Collaboration

    2016-09-01

    We present measurements of second-order azimuthal anisotropy (v2) at midrapidity (|y |<1.0 ) for light nuclei d ,t ,3He (for √{sN N}=200 , 62.4, 39, 27, 19.6, 11.5, and 7.7 GeV) and antinuclei d ¯ (√{sN N}=200 , 62.4, 39, 27, and 19.6 GeV) and ¯3He (√{sN N}=200 GeV) in the STAR (Solenoidal Tracker at RHIC) experiment. The v2 for these light nuclei produced in heavy-ion collisions is compared with those for p and p ¯. We observe mass ordering in nuclei v2(pT) at low transverse momenta (pT<2.0 GeV/c ). We also find a centrality dependence of v2 for d and d ¯. The magnitude of v2 for t and 3He agree within statistical errors. Light-nuclei v2 are compared with predictions from a blast-wave model. Atomic mass number (A ) scaling of light-nuclei v2(pT) seems to hold for pT/A <1.5 GeV /c . Results on light-nuclei v2 from a transport-plus-coalescence model are consistent with the experimental measurements.

  7. Theoretical Simulations of Reactive and Nonreactive Scattering of Light Diatomic Molecules from Metal Surfaces: Past, Present, and Future

    Directory of Open Access Journals (Sweden)

    C. Díaz

    2014-01-01

    Full Text Available In everyday life we are surrounded by surfaces and, therefore, by phenomena involving molecule-surface interactions. Furthermore, the processes of heterogeneous catalysis, which are governed by molecule-surface interactions, are of huge practical importance, because the production of most synthetic compounds involves catalytic processes, which explains the tremendous effort that surface science scientists have invested to understand the basic principles underlying elementary interactions between light molecules and surfaces. This effort was recognized in 2007 with the Nobel prize in chemistry awarded to Gerhard Ertl. Here we revise some of the most relevant studies performed so far in this field. We also point out the major challenges that the surface science community may face in this field in the years to come.

  8. Solid-core and hollow-core photonic crystal fiber for generation of bright ultraviolet light (Conference Presentation)

    Science.gov (United States)

    Joly, Nicolas Y.; Jiang, Xin; Travers, John C.; Ermolov, Alexey; Russell, Philip S.

    2016-09-01

    Over the last two decades the interest in photonic crystal fiber (PCF) has grown considerably, particularly in nonlinear optics where it allows enhanced control over the dispersion landscape. Although silica is the material most commonly used to fabricate PCF, its limited window of transmission and its susceptibility to optical damage at wavelengths below 350nm is driving the development of fibers made from glasses with transmission windows extending into the deep ultraviolet and the mid-infrared. An alternative is offered by gas-filled hollow-core fiber, in which the light propagates predominantly in the gas. In kagomé-style hollow-core PCF filled with noble gas, the weak anomalous dispersion of the empty fiber is balanced by the normal dispersion of the filling gas, resulting in a versatile system whose dispersion landscape can be adjusted in real time [Travers et al., JOSAB 28, A11 (2011)]. Under appropriate conditions the launched pulse undergoes soliton self-compression followed by emission of a band of dispersive radiation in the UV. UV light tunable down to 113 nm has been generated with this technique [Russell et al., Nat. Photon. 8, 278 (2014)]. Solid-core ZBLAN (fluorozirconate) glass PCF is transparent from 0.2 to 7.8µm. Launching 1nJ 140fs pulses at 1µm wavelength into a 1µm diameter core resulted, after 4cm of propagation, in generation of a supercontinuum spectrum extending from 210nm to beyond 2µm. In strong contrast to silica PCF, the ZBLAN PCF showed no signs of any solarization-related damage, even when operating over many hours [Jiang et al., Nat. Photon. 9, 133 (2015)].

  9. An analytic solution for energy loss and time-of-flight calculations for intermediate-energy light ions

    NARCIS (Netherlands)

    Snellings, RJM; Hulsbergen, W; Prendergast, EP; van den Brink, A; de Haas, AP; Habets, JJLM; Kamermans, R; Koopmans, M; Kuijer, PG; de Laat, CTAM; Ostendorf, RW; Peghaire, A; Rossewij, M

    1999-01-01

    Particle identification in intermediate heavy-ion collisions, using a modern 4 pi detector which contains several active layers, relies on a parametrisation or numerical integration of the energy loss in thick layers of detector material for different ions. Here an analytical solution applicable ove

  10. Towards a new test of time dilation: Laser spectroscopy on lithium ions stored at a velocity of 33.8 % of the speed of light

    OpenAIRE

    Novotny, Christian

    2008-01-01

    The subject of the presented thesis is the accurate measurement of time dilation, aiming at a quantitative test of special relativity. By means of laser spectroscopy, the relativistic Doppler shifts of a clock transition in the metastable triplet spectrum of ^7Li^+ are simultaneously measured with and against the direction of motion of the ions. By employing saturation or optical double resonance spectroscopy, the Doppler broadening as caused by the ions' velocity distribution is eliminated. ...

  11. Rapid MCNP simulation of DNA double strand break (DSB) relative biological effectiveness (RBE) for photons, neutrons, and light ions.

    Science.gov (United States)

    Stewart, Robert D; Streitmatter, Seth W; Argento, David C; Kirkby, Charles; Goorley, John T; Moffitt, Greg; Jevremovic, Tatjana; Sandison, George A

    2015-11-07

    To account for particle interactions in the extracellular (physical) environment, information from the cell-level Monte Carlo damage simulation (MCDS) for DNA double strand break (DSB) induction has been integrated into the general purpose Monte Carlo N-particle (MCNP) radiation transport code system. The effort to integrate these models is motivated by the need for a computationally efficient model to accurately predict particle relative biological effectiveness (RBE) in cell cultures and in vivo. To illustrate the approach and highlight the impact of the larger scale physical environment (e.g. establishing charged particle equilibrium), we examined the RBE for DSB induction (RBEDSB) of x-rays, (137)Cs γ-rays, neutrons and light ions relative to γ-rays from (60)Co in monolayer cell cultures at various depths in water. Under normoxic conditions, we found that (137)Cs γ-rays are about 1.7% more effective at creating DSB than γ-rays from (60)Co (RBEDSB  =  1.017) whereas 60-250 kV x-rays are 1.1 to 1.25 times more efficient at creating DSB than (60)Co. Under anoxic conditions, kV x-rays may have an RBEDSB up to 1.51 times as large as (60)Co γ-rays. Fission neutrons passing through monolayer cell cultures have an RBEDSB that ranges from 2.6 to 3.0 in normoxic cells, but may be as large as 9.93 for anoxic cells. For proton pencil beams, Monte Carlo simulations suggest an RBEDSB of about 1.2 at the tip of the Bragg peak and up to 1.6 a few mm beyond the Bragg peak. Bragg peak RBEDSB increases with decreasing oxygen concentration, which may create opportunities to apply proton dose painting to help address tumor hypoxia. Modeling of the particle RBE for DSB induction across multiple physical and biological scales has the potential to aid in the interpretation of laboratory experiments and provide useful information to advance the safety and effectiveness of hadron therapy in the treatment of cancer.

  12. Rapid MCNP simulation of DNA double strand break (DSB) relative biological effectiveness (RBE) for photons, neutrons, and light ions

    Science.gov (United States)

    Stewart, Robert D.; Streitmatter, Seth W.; Argento, David C.; Kirkby, Charles; Goorley, John T.; Moffitt, Greg; Jevremovic, Tatjana; Sandison, George A.

    2015-11-01

    To account for particle interactions in the extracellular (physical) environment, information from the cell-level Monte Carlo damage simulation (MCDS) for DNA double strand break (DSB) induction has been integrated into the general purpose Monte Carlo N-particle (MCNP) radiation transport code system. The effort to integrate these models is motivated by the need for a computationally efficient model to accurately predict particle relative biological effectiveness (RBE) in cell cultures and in vivo. To illustrate the approach and highlight the impact of the larger scale physical environment (e.g. establishing charged particle equilibrium), we examined the RBE for DSB induction (RBEDSB) of x-rays, 137Cs γ-rays, neutrons and light ions relative to γ-rays from 60Co in monolayer cell cultures at various depths in water. Under normoxic conditions, we found that 137Cs γ-rays are about 1.7% more effective at creating DSB than γ-rays from 60Co (RBEDSB  =  1.017) whereas 60-250 kV x-rays are 1.1 to 1.25 times more efficient at creating DSB than 60Co. Under anoxic conditions, kV x-rays may have an RBEDSB up to 1.51 times as large as 60Co γ-rays. Fission neutrons passing through monolayer cell cultures have an RBEDSB that ranges from 2.6 to 3.0 in normoxic cells, but may be as large as 9.93 for anoxic cells. For proton pencil beams, Monte Carlo simulations suggest an RBEDSB of about 1.2 at the tip of the Bragg peak and up to 1.6 a few mm beyond the Bragg peak. Bragg peak RBEDSB increases with decreasing oxygen concentration, which may create opportunities to apply proton dose painting to help address tumor hypoxia. Modeling of the particle RBE for DSB induction across multiple physical and biological scales has the potential to aid in the interpretation of laboratory experiments and provide useful information to advance the safety and effectiveness of hadron therapy in the treatment of cancer.

  13. Highly efficient and stable phosphorescent organic light-emitting diodes employing TADF materials as host (Conference Presentation)

    Science.gov (United States)

    Fukagawa, Hirohiko; Iwasaki, Yukiko; Shimizu, Takahisa

    2016-09-01

    The OLED is one of the key devices for realizing next-generation displays and lighting. The efficiency of OLEDs has been improved markedly by employing phosphorescent emitters. However, there are two main issues in the practical application of phosphorescent OLEDs (PHOLEDs): the relatively short operational lifetime of green/blue devices and the relatively high cost owing to the use of a costly emitter with a concentration of about 10% in the emitting layer. Here, we report on our success in resolving these issues by the utilization of thermally activated delayed fluorescent (TADF) materials as the host materials for phosphorescent emitters. Operationally stable green PHOLEDs are demonstrated by employing a TADF material as the host since the triplet excitons of the host, which are key elements in operational degradation, are transferred rapidly to the emitter following the Förster process via reverse intersystem crossing from the triplet to singlet states. In this case, the concentration of the emitter can be reduced to 1-3 wt%, similar to that in fluorescent OLEDs. Although an external quantum efficiency (EQE) of about 20% is obtained in many PHOLEDs regardless of the TADF host, the operational lifetime strongly depends on the host. Our optimized green PHOLED employing only 1 wt% phosphorescent emitter exhibits an EQE of over 20%, a small efficiency roll-off, and a long operational lifetime on the order of 10,000 h with an initial luminance of 1,000 cd/m2.

  14. Modeling short-range delivery and collection of light: incorporating the influence of the phase function (Conference Presentation)

    Science.gov (United States)

    Post, Anouk L.; Ruis, Roosje M.; Bloemen, Paul R.; van Leeuwen, Ton G.; Sterenborg, Henricus J. C. M.; Faber, Dirk J.

    2017-02-01

    The scattering phase function (the probability distribution of the scattering angle) is intimately associated with the cellular organization and ultrastructure of tissue. Since these physical parameters change during e.g. carcinogenesis; quantification of the phase function and related parameters may allow for improved non-invasive, in vivo discrimination between healthy and diseased tissue. Furthermore, for the derivation of models to interpret measured optical signals, assumptions about the phase function of tissue are often made - regularly assuming a Modified Henyey Greenstein. However, in contrast to other optical properties, the phase function has not yet been extensively measured for different tissue types. With conventional goniometers, the exact backscatter direction of 180 degrees cannot be measured. Especially for techniques that detect backscattered light - such as Optical Coherence Tomography and Elastic Scattering spectroscopy - the details of the backward part of the phase function will have a considerable impact on the measured signal. We have therefore developed a setup that can measure the backward part of the phase function: 134 to 180 degrees. Our design is based on full field Optical Coherence Tomography. We detect all angles simultaneously with a camera, while scanning the reference mirror. The phase function scales with the amplitude of the OCT signal for each angle. We will show our results for validation measurements on two silica bead samples of 200 nm and 400 nm beads.

  15. An update on the developmental status of the Spin-Light Polarimeter for the Electron Ion Collider

    CERN Document Server

    Mohanmurthy, Prajwal

    2014-01-01

    Precision experiments in the parity violating electron scattering (PVES) sector is one the leading methods to probe physics beyond the standard model (SM). A large part of the physics program being envisioned for future facilities such as the Electron Ion Collider (EIC) includes searching for physics beyond SM. Here, we present a novel technique which uses spacial asymmetry of synchrotron radiation produced by an electron beam passing through a wiggler magnet to trace the changes in beam polarization. Such a relative polarimeter could be vital if the goal of <0.5% polarimetry is to be achieved at EIC. In this paper, we update the discussion on the development of this technique supported by a Geant4 simulation. The polarimeter apparatus along with the underlying basic ideas are briefly introduced. As a part of the simulation, the effects of electron beam current and beam energy were studied which were found to be manageable over a wide range of electron beam energies and beam currents. It was found that suc...

  16. Proteasome particle-rich structures are widely present in human epithelial neoplasms: correlative light, confocal and electron microscopy study.

    Directory of Open Access Journals (Sweden)

    Vittorio Necchi

    Full Text Available A novel cytoplasmic structure has been recently characterized by confocal and electron microscopy in H. pylori-infected human gastric epithelium, as an accumulation of barrel-like proteasome reactive particles colocalized with polyubiquitinated proteins, H. pylori toxins and the NOD1 receptor. This proteasome particle-rich cytoplasmic structure (PaCS, a sort of focal proteasome hyperplasia, was also detected in dysplastic cells and was found to be enriched in SHP2 and ERK proteins, known to play a role in H. pylori-mediated gastric carcinogenesis. However, no information is available on its occurrence in neoplastic growths. In this study, surgical specimens of gastric cancer and various other human epithelial neoplasms have been investigated for PaCSs by light, confocal and electron microscopy including correlative confocal and electron microscopy (CCEM. PaCSs were detected in gastric cohesive, pulmonary large cell and bronchioloalveolar, thyroid papillary, parotid gland, hepatocellular, ovarian serous papillary, uterine cervix and colon adenocarcinomas, as well as in pancreatic serous microcystic adenoma. H. pylori bodies, their virulence factors (VacA, CagA, urease, and outer membrane proteins and the NOD1 bacterial proteoglycan receptor were selectively concentrated inside gastric cancer PaCSs, but not in PaCSs from other neoplasms which did, however, retain proteasome and polyubiquitinated proteins reactivity. No evidence of actual microbial infection was obtained in most PaCS-positive neoplasms, except for H. pylori in gastric cancer and capsulated bacteria in a colon cancer case. Particle lysis and loss of proteasome distinctive immunoreactivities were seen in some tumour cell PaCSs, possibly ending in sequestosomes or autophagic bodies. It is concluded that PaCSs are widely represented in human neoplasms and that both non-infectious and infectious factors activating the ubiquitin-proteasome system are likely to be involved in their origin

  17. Proteasome particle-rich structures are widely present in human epithelial neoplasms: correlative light, confocal and electron microscopy study.

    Science.gov (United States)

    Necchi, Vittorio; Sommi, Patrizia; Vanoli, Alessandro; Manca, Rachele; Ricci, Vittorio; Solcia, Enrico

    2011-01-01

    A novel cytoplasmic structure has been recently characterized by confocal and electron microscopy in H. pylori-infected human gastric epithelium, as an accumulation of barrel-like proteasome reactive particles colocalized with polyubiquitinated proteins, H. pylori toxins and the NOD1 receptor. This proteasome particle-rich cytoplasmic structure (PaCS), a sort of focal proteasome hyperplasia, was also detected in dysplastic cells and was found to be enriched in SHP2 and ERK proteins, known to play a role in H. pylori-mediated gastric carcinogenesis. However, no information is available on its occurrence in neoplastic growths. In this study, surgical specimens of gastric cancer and various other human epithelial neoplasms have been investigated for PaCSs by light, confocal and electron microscopy including correlative confocal and electron microscopy (CCEM). PaCSs were detected in gastric cohesive, pulmonary large cell and bronchioloalveolar, thyroid papillary, parotid gland, hepatocellular, ovarian serous papillary, uterine cervix and colon adenocarcinomas, as well as in pancreatic serous microcystic adenoma. H. pylori bodies, their virulence factors (VacA, CagA, urease, and outer membrane proteins) and the NOD1 bacterial proteoglycan receptor were selectively concentrated inside gastric cancer PaCSs, but not in PaCSs from other neoplasms which did, however, retain proteasome and polyubiquitinated proteins reactivity. No evidence of actual microbial infection was obtained in most PaCS-positive neoplasms, except for H. pylori in gastric cancer and capsulated bacteria in a colon cancer case. Particle lysis and loss of proteasome distinctive immunoreactivities were seen in some tumour cell PaCSs, possibly ending in sequestosomes or autophagic bodies. It is concluded that PaCSs are widely represented in human neoplasms and that both non-infectious and infectious factors activating the ubiquitin-proteasome system are likely to be involved in their origin. PaCS detection

  18. Development of a Novel Test Method for On-Demand Internal Short Circuit in a Li-Ion Cell (Presentation)

    Energy Technology Data Exchange (ETDEWEB)

    Keyser, M.; Long, D.; Jung, Y. S.; Pesaran, A.; Darcy, E.; McCarthy, B.; Patrick, L.; Kruger, C.

    2011-01-01

    This presentation describes a cell-level test method that simulates an emergent internal short circuit, produces consistent and reproducible test results, can establish the locations and temperatures/power/SOC conditions where an internal short circuit will result in thermal runaway, and provides relevant data to validate internal short circuit models.

  19. More than just a vulnerable pipeline: xylem physiology in the light of ion-mediated regulation of plant water transport.

    Science.gov (United States)

    Nardini, Andrea; Salleo, Sebastiano; Jansen, Steven

    2011-10-01

    Major restrictions to the hydraulic conductance of xylem (K(XYL)) in vascular plants have traditionally been attributed to anatomical constraints. More recently, changes in the cationic concentration of xylem sap have been suggested to be responsible for short-term changes in K(XYL) based on data for 35 dicot species, and very few gymnosperms and ferns, indicating that xylem water transport may no longer be considered as an entirely passive process. Recent studies have revealed that this so-called ionic effect: (i) varies from little or no increase to >30%, (ii) is species specific, (iii) changes on a seasonal basis, (iv) depends on the cationic concentration, (v) is enhanced in embolized stems, and (vi) is positively correlated with vessel grouping. Furthermore, the ionic effect has been suggested to play functional roles in planta with respect to: (i) phloem-mediated control of xylem hydraulic properties, (ii) compensation of cavitation-induced loss of hydraulic conductance, with the result of optimizing light and water utilization, and (iii) differential regulation of water delivery to branches exposed to different levels of light. Pits are likely to play a key role in the ionic effect, which has largely been explained as a consequence of the poly-electrolytic nature and hydrogel properties of the pectic matrix of interconduit pit membranes, despite little evidence that pit membrane pectins remain present after cell hydrolysis. More research is needed to address the ionic effect in more species, physico-chemical properties of pit membranes, and how the ionic effect may increase xylem hydraulic conductance 'on demand'.

  20. Presentation-Practice-Production and Task-Based Learning in the Light of Second Language Learning Theories.

    Science.gov (United States)

    Ritchie, Graeme

    2003-01-01

    Features of presentation-practice-production (PPP) and task-based learning (TBL) models for language teaching are discussed with reference to language learning theories. Pre-selection of target structures, use of controlled repetition, and explicit grammar instruction in a PPP lesson are given. Suggests TBL approaches afford greater learning…

  1. Presentation-Practice-Production and Task-Based Learning in the Light of Second Language Learning Theories.

    Science.gov (United States)

    Ritchie, Graeme

    2003-01-01

    Features of presentation-practice-production (PPP) and task-based learning (TBL) models for language teaching are discussed with reference to language learning theories. Pre-selection of target structures, use of controlled repetition, and explicit grammar instruction in a PPP lesson are given. Suggests TBL approaches afford greater learning…

  2. All Ca(2+)-binding loops of light-sensitive ctenophore photoprotein berovin bind magnesium ions: The spatial structure of Mg(2+)-loaded apo-berovin.

    Science.gov (United States)

    Burakova, Ludmila P; Natashin, Pavel V; Malikova, Natalia P; Niu, Fengfeng; Pu, Mengchen; Vysotski, Eugene S; Liu, Zhi-Jie

    2016-01-01

    Light-sensitive photoprotein berovin accounts for a bright bioluminescence of ctenophore Beroe abyssicola. Berovin is functionally identical to the well-studied Ca(2+)-regulated photoproteins of jellyfish, however in contrast to those it is extremely sensitive to the visible light. Berovin contains three EF-hand Ca(2+)-binding sites and consequently belongs to a large family of the EF-hand Ca(2+)-binding proteins. Here we report the spatial structure of apo-berovin with bound Mg(2+) determined at 1.75Å. The magnesium ion is found in each functional EF-hand loop of a photoprotein and coordinated by oxygen atoms donated by the side-chain groups of aspartate, carbonyl groups of the peptide backbone, or hydroxyl group of serine with characteristic oxygen-Mg(2+) distances. As oxygen supplied by the side-chain of the twelfth residue of all Ca(2+)-binding loops participates in the magnesium ion coordination, it was suggested that Ca(2+)-binding loops of berovin belong to the mixed Ca(2+)/Mg(2+) rather than Ca(2+)-specific type. In addition, we report an effect of physiological concentration of Mg(2+) on bioluminescence of berovin (sensitivity to Ca(2+), rapid-mixed kinetics, light-sensitivity, thermostability, and apo-berovin conversion into active protein). The different impact of physiological concentration of Mg(2+) on berovin bioluminescence as compared to hydromedusan photoproteins was attributed to different affinities of the Ca(2+)-binding sites of these photoproteins to Mg(2+).

  3. Fragmentation of the C60 molecule in collision with light ions studied by a multi-correlation technique. Cross-sections, electron spectroscopy; Fragmentation de la molecule C60 par impact d'ions legers etudiee en multicorrelation. Sections efficaces, spectroscopie d'electrons

    Energy Technology Data Exchange (ETDEWEB)

    Rentenier, A

    2004-04-01

    A quantitative study of the C60 fullerenes fragmentation in collision with light ions (H{sub n}{sup +} with n=1,2,3, He{sup q+} with q=1,2) in the velocity range 0,1 - 2,3 u.a.) is presented. The multi-correlation technique, developed between fragment ions and electrons with well defined energy, has enlightened some of the dependences and properties of fragmentation mechanisms (cross sections, electron spectroscopy, size distributions, kinetic energy of fragment ions, Campi's scatter plot, activation energies). The deposited energy hence appeared as an important parameter. Cross sections have been measured, for the first time, for all the collisional processes. Ionisation and capture only depends on the collision velocity. On the other hand, scaling laws with the deposited energy have been observed for the cross sections of multifragmentation, which depends on the collision energy and the nature of the projectile. The deposited energy has also been found as an essential parameter to understand the evolution of the charged fragment size distributions. The electron spectroscopy, achieved at an emission angle of 35 degrees, showed spectra peaked at important energies (from 5 to 20 eV). The spectra shape depends on the collision velocity. A first theoretical analysis points out the link between the observed energy distribution and the presence of a centrifugal potential barrier. Finally, correlation experiments between produced ions and electron energy reveal that electron energy increases with internal energy. (author)

  4. Relativistically induced transparency acceleration of light ions by an ultrashort laser pulse interacting with a heavy-ion-plasma density gradient

    Science.gov (United States)

    Sahai, Aakash A.; Tsung, Frank S.; Tableman, Adam R.; Mori, Warren B.; Katsouleas, Thomas C.

    2013-10-01

    The relativistically induced transparency acceleration (RITA) scheme of proton and ion acceleration using laser-plasma interactions is introduced, modeled, and compared to the existing schemes. Protons are accelerated with femtosecond relativistic pulses to produce quasimonoenergetic bunches with controllable peak energy. The RITA scheme works by a relativistic laser inducing transparency [Akhiezer and Polovin, Zh. Eksp. Teor. Fiz 30, 915 (1956); Kaw and Dawson, Phys. FluidsPFLDAS0031-917110.1063/1.1692942 13, 472 (1970); Max and Perkins, Phys. Rev. Lett.PRLTAO0031-900710.1103/PhysRevLett.27.1342 27, 1342 (1971)] to densities higher than the cold-electron critical density, while the background heavy ions are stationary. The rising laser pulse creates a traveling acceleration structure at the relativistic critical density by ponderomotively [Lindl and Kaw, Phys. FluidsPFLDAS0031-917110.1063/1.1693437 14, 371 (1971); Silva , Phys. Rev. E1063-651X10.1103/PhysRevE.59.2273 59, 2273 (1999)] driving a local electron density inflation, creating an electron snowplow and a co-propagating electrostatic potential. The snowplow advances with a velocity determined by the rate of the rise of the laser's intensity envelope and the heavy-ion-plasma density gradient scale length. The rising laser is incrementally rendered transparent to higher densities such that the relativistic-electron plasma frequency is resonant with the laser frequency. In the snowplow frame, trace density protons reflect off the electrostatic potential and get snowplowed, while the heavier background ions are relatively unperturbed. Quasimonoenergetic bunches of velocity equal to twice the snowplow velocity can be obtained and tuned by controlling the snowplow velocity using laser-plasma parameters. An analytical model for the proton energy as a function of laser intensity, rise time, and plasma density gradient is developed and compared to 1D and 2D PIC OSIRIS [Fonseca , Lect. Note Comput. Sci.9783

  5. Spectrometry of the Rutherford backscattering of ions and the Raman scattering of light in GaS single crystals irradiated with 140-keV H{sub 2}{sup +} ions

    Energy Technology Data Exchange (ETDEWEB)

    Garibov, A. A.; Madatov, R. S., E-mail: msrahim@mail.ru [Azerbaijan National Academy of Sciences, Institute of Radiation Problems (Azerbaijan); Komarov, F. F.; Pilko, V. V. [Belarus State University, RTCCU of “Nanotechnology and Physical Electronics” (Belarus); Mustafayev, Yu. M.; Akhmedov, F. I.; Jakhangirov, M. M. [Azerbaijan National Academy of Sciences, Institute of Radiation Problems (Azerbaijan)

    2015-05-15

    The methods of the Raman scattering of light and Rutherford backscattering are used to study the degree of structural disorder in layered GaS crystals before and after irradiation with 140-keV H{sub 2}{sup +} ions. It is shown that the distribution of the crystal’s components over depth is homogeneous; for doses as high as 5 × 10{sup 15} cm{sup −2}, the stoichiometric composition of the compound’s components is retained. The experimental value of the critical dose for the beginning of amorphization amounts to about 5 × 10{sup 15} cm{sup −2} and is in accordance with the calculated value. The results obtained by the method of the Raman scattering of light confirm conservation of crystalline structure and the start of the amorphization process.

  6. Synchronized ion acceleration by ultraintense slow light and electron source for x-ray production from low-density targets

    Science.gov (United States)

    Brantov, A. V.; Bychenkov, V. Yu

    2017-03-01

    Synchronized proton acceleration by ultraintense slow light in a low-density target Brantov et al (2016 Phys. Rev. Lett. 116 085004) is studied for a circularly polarized laser pulse. This study demonstrates the advantage of circularly polarized light compared with linearly polarized light used for high-energy proton generation. At the same time, high-energy electron production for gamma-ray generation is not sensitive to the polarization of the laser pulse. Both the proton and the electron sources are considered in application to petawatt-class lasers.

  7. Polarized negative ions

    Energy Technology Data Exchange (ETDEWEB)

    Haeberli, W.

    1981-04-01

    This paper presents a survey of methods, commonly in use or under development, to produce beams of polarized negative ions for injection into accelerators. A short summary recalls how the hyperfine interaction is used to obtain nuclear polarization in beams of atoms. Atomic-beam sources for light ions are discussed. If the best presently known techniques are incorporated in all stages of the source, polarized H/sup -/ and D/sup -/ beams in excess of 10 ..mu..A can probably be achieved. Production of polarized ions from fast (keV) beams of polarized atoms is treated separately for atoms in the H(25) excited state (Lamb-Shift source) and atoms in the H(1S) ground state. The negative ion beam from Lamb-Shift sources has reached a plateau just above 1 ..mu..A, but this beam current is adequate for many applications and the somewhat lower beam current is compensated by other desirable characteristics. Sources using fast polarized ground state atoms are in a stage of intense development. The next sections summarize production of polarized heavy ions by the atomic beam method, which is well established, and by optical pumping, which has recently been demonstrated to yield very large nuclear polarization. A short discussion of proposed ion sources for polarized /sup 3/He/sup -/ ions is followed by some concluding remarks.

  8. Characterization and photocatalytic performance evaluation of various metal ion-doped microstructured TiO2 under UV and visible light.

    Science.gov (United States)

    Sahoo, Chittaranjan; Gupta, Ashok K

    2015-01-01

    Commercially available microcrystalline TiO2 was doped with silver, ferrous and ferric ion (1.0 mol %) using silver nitrate, ferrous sulfate and ferric nitrate solutions following the liquid impregnation technology. The catalysts prepared were characterised by FESEM, XRD, FTIR, DRS, particle size and micropore analysis. The photocatalytic activity of the prepared catalysts was tested on the degradation of two model dyes, methylene blue (3,7-bis (Dimethylamino)-phenothiazin-5-ium chloride, a cationic thiazine dye) and methyl blue (disodium;4-[4-[[4-(4-sulfonatoanilino)phenyl]-[4-(4-sulfonatophenyl)azaniumylidenecyclohexa-2,5-dien-1-ylidene]methyl]anilino]benzene sulfonate, an anionic triphenyl methane dye) under irradiation by UV and visible light in a batch reactor. The efficiency of the photocatalysts under UV and visible light was compared to ascertain the light range for effective utilization. The catalysts were found to have the anatase crystalline structure and their particle size is in a range of 140-250 nm. In the case of Fe(2+) doped TiO2 and Fe(3+) doped TiO2, there was a greater shift in the optical absorption towards the visible range. Under UV light, Ag(+) doped TiO2 was the most efficient catalyst and the corresponding decolorization was more than 99% for both the dyes. Under visible light, Fe(3+) doped TiO2 was the most efficient photocatalyst with more than 96% and 90% decolorization for methylene blue and methyl blue, respectively. The kinetics of the reaction under both UV and visible light was investigated using the Langmuir-Hinshelwood pseudo-first-order kinetic model. Kinetic measurements confirmed that, Ag(+) doped TiO2 was most efficient in the UV range, while Fe(3+) doped TiO2 was most efficient in the visible range.

  9. Unpolarized, incoherent repumping light for prevention of dark states in a trapped and laser-cooled single ion

    CERN Document Server

    Lindvall, T; Tittonen, I; Merimaa, M

    2013-01-01

    Many ion species commonly used for laser-cooled ion trapping studies have a low-lying metastable 2D3/2 state that can become populated due to spontaneous emission from the 2P1/2 excited state. This requires a repumper laser to maintain the ion in the Doppler cooling cycle. Typically the 2D3/2 state, or some of its hyperfine components if the ion has nuclear spin, has a higher multiplicity than the upper state of the repumping transition. This can lead to dark states, which have to be destabilized by an external magnetic field or by modulating the polarization of the repumper laser. We propose using unpolarized, incoherent amplified spontaneous emission (ASE) to drive the repumping transition. An ASE source offers several advantages compared to a laser. It prevents the buildup of dark states without external polarization modulation even in zero magnetic field, it can drive multiple hyperfine transitions simultaneously, and it requires no frequency stabilization. These features make it very compact and robust, ...

  10. Impact of metal ions in porphyrin-based applied materials for visible-light photocatalysis: Key information from ultrafast electronic spectroscopy

    KAUST Repository

    Kar, Prasenjit

    2014-07-10

    ProtoporphyrinIX-zinc oxide (PP-ZnO) nanohybrids have been synthesized for applications in photocatalytic devices. High-resolution transmission electron microscopy (HRTEM), X-ray diffraction (XRD), and steady-state infrared, absorption, and emission spectroscopies have been used to analyze the structural details and optical properties of these nanohybrids. Time-resolved fluorescence and transient absorption techniques have been applied to study the ultrafast dynamic events that are key to photocatalytic activities. The photocatalytic efficiency under visible-light irradiation in the presence of naturally abundant iron(III) and copper(II) ions has been found to be significantly retarded in the former case, but enhanced in the latter case. More importantly, femtosecond (fs) transient absorption data have clearly demonstrated that the residence of photoexcited electrons from the sensitizer PP in the centrally located iron moiety hinders ground-state bleach recovery of the sensitizer, affecting the overall photocatalytic rate of the nanohybrid. The presence of copper(II) ions, on the other hand, offers additional stability against photobleaching and eventually enhances the efficiency of photocatalysis. In addition, we have also explored the role of UV light in the efficiency of photocatalysis and have rationalized our observations from femtosecond- to picosecond-resolved studies. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. Impact of metal ions in porphyrin-based applied materials for visible-light photocatalysis: key information from ultrafast electronic spectroscopy.

    Science.gov (United States)

    Kar, Prasenjit; Sardar, Samim; Alarousu, Erkki; Sun, Jingya; Seddigi, Zaki S; Ahmed, Saleh A; Danish, Ekram Y; Mohammed, Omar F; Pal, Samir Kumar

    2014-08-11

    Protoporphyrin IX-zinc oxide (PP-ZnO) nanohybrids have been synthesized for applications in photocatalytic devices. High-resolution transmission electron microscopy (HRTEM), X-ray diffraction (XRD), and steady-state infrared, absorption, and emission spectroscopies have been used to analyze the structural details and optical properties of these nanohybrids. Time-resolved fluorescence and transient absorption techniques have been applied to study the ultrafast dynamic events that are key to photocatalytic activities. The photocatalytic efficiency under visible-light irradiation in the presence of naturally abundant iron(III) and copper(II) ions has been found to be significantly retarded in the former case, but enhanced in the latter case. More importantly, femtosecond (fs) transient absorption data have clearly demonstrated that the residence of photoexcited electrons from the sensitizer PP in the centrally located iron moiety hinders ground-state bleach recovery of the sensitizer, affecting the overall photocatalytic rate of the nanohybrid. The presence of copper(II) ions, on the other hand, offers additional stability against photobleaching and eventually enhances the efficiency of photocatalysis. In addition, we have also explored the role of UV light in the efficiency of photocatalysis and have rationalized our observations from femtosecond- to picosecond-resolved studies. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. Two-Gluon Correlations in Heavy-Light Ion Collisions: Energy and Geometry Dependence, IR Divergences, and $k_T$-Factorization

    CERN Document Server

    Kovchegov, Yuri V

    2013-01-01

    We study the properties of the cross section for two-gluon production in heavy-light ion collisions derived in our previous paper on the subject in the saturation/Color Glass Condensate framework. Concentrating on the energy and geometry dependence of the corresponding correlation functions we find that the two-gluon correlator is a much slower function of the center-of-mass energy than the one- and two-gluon production cross sections. The geometry dependence of the correlation function leads to stronger azimuthal near- and away-side correlations in the tip-on-tip U+U collisions than in the side-on-side U+U collisions, an exactly opposite behavior from the correlations generated by the elliptic flow of the quark-gluon plasma: a study of azimuthal correlations in the U+U collisions may thus help to disentangle the two sources of correlations. We demonstrate that the cross section for two-gluon production in heavy-light ion collisions contains a power-law infrared (IR) divergence even for fixed produced gluon m...

  13. Analysis of the interaction between Bacillus coagulans and Bacillus thuringiensis S-layers and calcium ions by XRD, light microscopy, and FTIR.

    Science.gov (United States)

    Babolmorad, Ghazal; Emtiazi, Giti; Emamzadeh, Rahman

    2014-05-01

    S-layer is a self-assemble regularly crystalline surface that covers major cell wall component of many bacteria and archaea and exhibits a high metal-binding capacity. We have studied the effect of the calcium ions and type of solid support (glass or mica) on the structure of the S-layers from Bacillus coagulans HN-68 and Bacillus thuringiensis MH14 upon simple methods based on light microscopy and AFM. Furthermore, the Fourier transform infrared spectroscopy (FTIR) study is indicated that the calcium-S-layer interaction occurred mainly through the carboxylate groups of the side chains of aspartic acid (Asp) and glutamic acid (Glu) and nitrogen atoms of Lys, Asn, and histidine (His) amino acids and N-H groups of the peptide backbone. Studied FTIR revealed that inner faces of S-layer are mainly negative, and outer faces of S-layer are mainly positive. Probably, calcium ions with positive charges bound to the carboxyl groups of Glu and Asp. Accordingly, calcium ions are anchored in the space between the inner faces of S-layer with negative charge and the surface of mica with negative charge. This leads to regular arrangement of the S-layer subunits.

  14. Light-Controlled Release and Uptake of Zinc Ions in Solution by a Photochromic Terthiazole-Based Ligand.

    Science.gov (United States)

    Guérin, Juliette; Léaustic, Anne; Berthet, Jérôme; Métivier, Rémi; Guillot, Régis; Delbaere, Stéphanie; Nakatani, Keitaro; Yu, Pei

    2017-03-22

    We have synthesized and fully characterized a photochromic zinc complex with a terphenylthiazole-based ligand with a salen-like cavity. The solution stability of the complex was found to be greatly dependent on the state of the photochromic ligand and an interesting photo-triggered release and uptake of zinc ions was found as well as monitored by its fluorescence. The contrasting stability difference of the zinc complex between its two isomeric states was rationalized by DFT calculations.

  15. Formation of donor centers upon the annealing of silicon light-emitting structures implanted with oxygen ions

    Energy Technology Data Exchange (ETDEWEB)

    Sobolev, N. A., E-mail: nick@sobolev.ioffe.rssi.ru; Danilov, D. V. [Russian Academy of Sciences, Ioffe Physical-Technical Institute (Russian Federation); Aleksandrov, O. V. [St. Petersburg Electrotechnical University LETI (Russian Federation); Loshachenko, A. S.; Sakharov, V. I.; Serenkov, I. T.; Shek, E. I.; Trapeznikova, I. N. [Russian Academy of Sciences, Ioffe Physical-Technical Institute (Russian Federation)

    2015-03-15

    It is found that the implantation of silicon with oxygen ions and subsequent annealing at high temperatures are accompanied by the formation of electrically active donor centers and by the p-n conversion of the conductivity of silicon. The concentration and spatial distribution of these centers depend on the annealing temperature. The results are accounted for by the interaction of oxygen atoms with intrinsic point defects formed upon the annealing of implantation damages.

  16. Ultra-light Hierarchical Graphene Electrode for Binder-Free Supercapacitors and Lithium-Ion Battery Anodes.

    Science.gov (United States)

    Zuo, Zicheng; Kim, Tae Young; Kholmanov, Iskandar; Li, Huifeng; Chou, Harry; Li, Yuliang

    2015-10-07

    A mild and environmental-friendly method is developed for fabricating a 3D interconnected graphene electrode with large-scale continuity. Such material has interlayer pores between reduced graphene oxide nanosheets and in-plane pores. Hence, a specific surface area up to 835 m(2) g(-1) and a high powder conductivity up to 400 S m(-1) are achieved. For electrochemical applications, the interlayer pores can serve as "ion-buffering reservoirs" while in-plane ones act as "channels" for shortening the mass cross-plane diffusion length, reducing the ion response time, and prevent the interlayer restacking. As binder-free supercapacitor electrode, it delivers a specific capacitance up to 169 F g(-1) with surface-normalized capacitance close to 21 μF cm(-2) (intrinsic capacitance) and power density up to 7.5 kW kg(-1), in 6 m KOH aqueous electrolyte. In the case of lithium-ion battery anode, it shows remarkable advantages in terms of the initiate reversible Coulombic efficiency (61.3%), high specific capacity (932 mAh g(-1) at 100 mA g(-1)), and robust long-term retention (93.5% after 600 cycles at 2000 mAh g(-1)). © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. 2,4-D abatement from groundwater samples by photo-Fenton processes at circumneutral pH using naturally iron present. Effect of inorganic ions.

    Science.gov (United States)

    Gutiérrez-Zapata, Héctor M; Rojas, Karen L; Sanabria, Janeth; Rengifo-Herrera, Julián Andrés

    2017-03-01

    This study evaluated, at laboratory scale, if the using iron naturally present (0.3 mg L(-1)) and adding 10 mg L(-1) of hydrogen peroxide was effective to remove 24.3 mgL(-1) of 2,4-dichlorophenoxyacetic acid (2,4-D) from groundwater samples by simulated solar irradiation (global intensity = 300 W m(-2)). Under these conditions, the degradation of 2,4-D reached 75.2 % and the apparition of its main oxidation byproduct 2,4-dichlorophenol (DCP) was observed. On the other hand, pH exhibited an increasing from 7.0 to 8.3 during the experiment. Experiments using Milli-Q water at pH 7.0, iron, and H2O2 concentrations of 0.3 and 10 mg L(-1), respectively, were carried out in order to study the effect of ions such as carbonate species, phosphate, and fluoride in typical concentrations often found in groundwater. Ion concentrations were combined by using a factorial experimental design 2(3). Results showed that carbonates and fluoride did not produce a detrimental effect on the 2,4-D degradation, while phosphate inhibited the process. In this case, the pH increased also from 7.0 to 7.95 and 8.99. Effect of parameters such as pH, iron concentration, and hydrogen peroxide concentration on the 2,4-D degradation by the photo-Fenton process in groundwater was evaluated by using a factorial experimental design 2(3). Results showed that the pH was the main parameter affecting the process. This study shows for the first time that using the photo-Fenton process at circumneutral pH and iron naturally present seems to be a promising process to remove pesticides from groundwater.

  18. [Pollution Characteristics and Light Extinction Effects of Water-soluble Ions in PM2.5 During Winter Hazy Days at North Suburban Nanjing].

    Science.gov (United States)

    Zhou, Yao-yao; Ma, Yan; Zheng, Jun; Cui, Fen-ping; Wang, Li

    2015-06-01

    To investigate the characteristics of water-soluble ions in PM2.5 and their contribution to light extinction in haze days, on-line monitoring of PM2.5. was conducted at North Suburban Nanjing from 25 January through 3 February, 2013. Water-soluble components were collected with a particle-into-liquid sampler (PILS), and analyzed by ion chromatography (IC) for the contents of SO4(2-), NO3-, NH4+, Cl-, Na+, K+, Mg2+ and Ca2+ Simultaneously particle size distributions were measured using scanning mobility particle sizer (SMPS) and Aerodynamic Particle Sizer (APS). The absorption and scattering coefficients were measured by three-wavelength photoacoustic soot spectrometer (PASS-3). Trace gases (SO2, NO2 etc.) were also monitored. The results showed that the average concentrations of total water-soluble ions were 70.3 and 22.9 microg x m(-3) in haze and normal days, respectively. Secondary hygroscopic components including SO4(2-), NO3- and NH4+ were the major ionic pollutants. Hazy days favored the conversion of SO2 and NOx, to SO4(2-) and NO3-, respectively, and in particular the oxidation of NOx. Using multiple linear regression statistical method, the empirical relationship between the dry aerosol extinction coefficient and the chemical composition was established. NH4NO3 was found to be the largest contributor to aerosol extinction in winter in Nanjing, followed by (NH4)2SO4, OC and EC. In two heavy pollution events, the increase of ion concentrations was influenced by the increase of primary emissions and secondary transformation.

  19. Degree of conversion of different composite resins photo-activated with light-emitting diode and argon ion laser

    Science.gov (United States)

    Messias, A. M.; Galvão, M. R.; Boaventura, J. M. C.; Jacomassi, D. P.; Bernardi, M. I. B.; Bagnato, V. S.; Rastelli, A. N. S.; Andrade, M. F.

    2015-02-01

    This study evaluated the degree of conversion (DC%) of one experimental and different brands of composite resins light-cured by two light sources (one LED and one argon laser). The percentage of unreacted C = C was determined from the ratio of absorbance intensities of aliphatic C = C (peak at 1637 cm-1) against internal standards before and after curing: aromatic C-C (peak at 1610 cm-1) except for P90, where %C = C bonds was given for C-O-C (883 cm-1) and C-C (1257 cm-1). ANOVA and Tukey’s test revealed no statistically significant difference among Z350 (67.17), Z250 (69.52) and experimental (66.61  ±  2.03) with LED, just among them and Evolu-X (75.51) and P90 (32.05) that showed higher and lower DC%, respectively. For the argon laser, there were no differences among Z250 (70.67), Z350 (69.60), experimental (65.66) and Evolu-X (73, 37), however a significant difference was observed for P90 (36.80), which showed lowest DC%. The light sources showed similar DC%, however the main difference was observed regarding the composite resins. The lowest DC% was observed for the argon laser. P90 showed the lowest DC% for both light-curing sources.

  20. Heavy ion acceleration in the Breakout Afterburner regime

    CERN Document Server

    Petrov, G M; Thomas, A G R; Krushelnick, K; Beg, F N

    2015-01-01

    Theoretical study of heavy ion acceleration from an ultrathin (20 nm) gold foil irradiated by sub-picosecond lasers is presented. Using two dimensional particle-in-cell simulations we identified two highly efficient ion acceleration schemes. By varying the laser pulse duration we observed a transition from Radiation Pressure Acceleration to the Breakout Afterburner regime akin to light ions. The underlying physics and ion acceleration regimes are similar to that of light ions, however, nuances of the acceleration process make the acceleration of heavy ions more challenging. Two laser systems are studied in detail: the Texas Petawatt Laser and the Trident laser, the former having pulse duration 180 fs, intermediate between very short femtosecond pulses and picosecond pulses. Both laser systems generated directional gold ions beams (~10 degrees half-angle) with fluxes in excess of 1011 ion/sr and normalized energy >10 MeV/nucleon.

  1. Influence of ageing on Raman spectra and the conductivity of monolayer graphene samples irradiated by heavy and light ions

    Energy Technology Data Exchange (ETDEWEB)

    Butenko, A.; Zion, E.; Richter, V.; Sharoni, A. [Institute of Nanotechnology and Advanced Materials, Bar-Ilan University, Ramat Gan 52900 (Israel); Kaganovskii, Yu.; Wolfson, L.; Kogan, E.; Kaveh, M.; Shlimak, I. [Department of Physics, Jack and Pearl Resnick Institute, Bar-Ilan University, Ramat Gan 52900 (Israel)

    2016-07-28

    The influence of long-term ageing (about one year) on the Raman scattering (RS) spectra and the temperature dependence of conductivity has been studied in two series of monolayer graphene samples irradiated by different doses of C{sup +} and Xe{sup +} ions. It is shown that the main result of ageing consists of changes in the intensity and position of D- and G- and 2D-lines in RS spectra and in an increase of the conductivity. The observed effects are explained in terms of an increase of the radius of the “activated” area around structural defects.

  2. Yb3+ Ion Upconversion Luminescence from YbEr:ZBLAN Glass Excited by 966 nm Laser Light

    Institute of Scientific and Technical Information of China (English)

    CHEN Xiao-Bo; NIE Yu-Xin; WEN Ou

    2001-01-01

    The upconversion lumiuescence of several YbEr co-doped Zr-Ba-La-AI-Na (ZBLAN) glass samples (Er(0.5) Yb(3): ZBLAN, Er(0.5)Yb(1):ZBLAN and Er(0.5):ZBLAN) has been studied. A new kind of upconversion cooperative radiation fluorescence, which comes from coupled cluster states of two Yb3+ ions has been observed. This is significant in that it may lead to a new path to achieve blue upconversion luminescence, which has promising upconversion applications.

  3. Instrumentation: Ion Chromatography.

    Science.gov (United States)

    Fritz, James S.

    1987-01-01

    Discusses the importance of ion chromatography in separating and measuring anions. The principles of ion exchange are presented, along with some applications of ion chromatography in industry. Ion chromatography systems are described, as well as ion pair and ion exclusion chromatography, column packings, detectors, and programming. (TW)

  4. Impedimetric Sensing Proprieties of ITO Electrodes Functionalized with PEDOT:PSS/Azo-Calix[4]Arene for the Detection of Al3+ Ions Under Light Excitation

    Science.gov (United States)

    Echabaane, M.; Rouis, A.; Mahjoub, M. A.; Bonnamour, I.; Ben Ouada, H.

    2016-08-01

    This study describes an investigation of the sensitivity of the azo-calix[4]arene/poly(3,4-ethylenedioxythiophene)/poly-(styrenesulfonate) (PEDOT:PSS) thin film deposited on the indium tin oxide (ITO) electrode surface toward aluminum ions (Al3+) under light excitation. Thin films were deposited by the spin-coating technique. Adhesion of these films to the ITO surface was highlighted by performing contact angle measurements. Then, interfaces of the azo-calix[4]arene/PEDOT:PSS thin film were characterized by impedance measurements using electrochemical impedance spectroscopy. Obtained impedance spectra were fitted using an equivalent circuit. Finally, evolutions of the different components of this circuit were studied. These evolutions show that the sensitivity of the azo-calix[4]arene/PEDOT:PSS/ITO electrode is remarkably improved under illumination.

  5. Impedimetric Sensing Proprieties of ITO Electrodes Functionalized with PEDOT:PSS/Azo-Calix[4]Arene for the Detection of Al3+ Ions Under Light Excitation

    Science.gov (United States)

    Echabaane, M.; Rouis, A.; Mahjoub, M. A.; Bonnamour, I.; Ben Ouada, H.

    2017-01-01

    This study describes an investigation of the sensitivity of the azo-calix[4]arene/poly(3,4-ethylenedioxythiophene)/poly-(styrenesulfonate) (PEDOT:PSS) thin film deposited on the indium tin oxide (ITO) electrode surface toward aluminum ions (Al3+) under light excitation. Thin films were deposited by the spin-coating technique. Adhesion of these films to the ITO surface was highlighted by performing contact angle measurements. Then, interfaces of the azo-calix[4]arene/PEDOT:PSS thin film were characterized by impedance measurements using electrochemical impedance spectroscopy. Obtained impedance spectra were fitted using an equivalent circuit. Finally, evolutions of the different components of this circuit were studied. These evolutions show that the sensitivity of the azo-calix[4]arene/PEDOT:PSS/ITO electrode is remarkably improved under illumination.

  6. Weighted difference of g-factors of light Li-like and H-like ions for an improved determination of the fine-structure constant

    CERN Document Server

    Yerokhin, V A; Harman, Z; Tupitsyn, I I; Keitel, C H

    2016-01-01

    A weighted difference of the $g$-factors of the Li- and H-like ion of the same element is studied and optimized in order to maximize the cancellation of nuclear effects. To this end, a detailed theoretical investigation is performed for the finite nuclear size correction to the one-electron $g$-factor, the one- and two-photon exchange effects, and the QED effects. The coefficients of the $Z\\alpha$ expansion of these corrections are determined, which allows us to set up the optimal definition of the weighted difference. It is demonstrated that, for moderately light elements, such weighted difference is nearly free from uncertainties associated with nuclear effects and can be utilized to extract the fine-structure constant from bound-electron $g$-factor experiments with an accuracy competitive with or better than its current literature value.

  7. Operational Experience with The GTS-LHC Ion Source and Future Developments of The CERN Ion Injector

    CERN Document Server

    Kuchler, D; Lombardi, A; O'Neil, M; Scrivens, R; Stafford-Haworth, J; Thomae, R

    2012-01-01

    Since 2010 the GTS-LHC source delivers lead ions for heavy ion physics at the LHC. Several modifications allowed the improvement the source reliability and the beam stability. The attempts to improve the beam intensity were less successful. The different modifications and actual performance figures will be presented in this paper. In addition to the heavy ion physics program of the LHC new ion species will be requested for different experiments in the future. The fixed target experiment NA61 requires primary argon and xenon beams. And a future biomedical facility asks for light ions in the range helium to neon. Approaches to prepare these beams and to modify the ion injector towards a light ion front end are presented.

  8. Two-gluon correlations in heavy–light ion collisions: Energy and geometry dependence, IR divergences, and k{sub T}-factorization

    Energy Technology Data Exchange (ETDEWEB)

    Kovchegov, Yuri V., E-mail: kovchegov.1@asc.ohio-state.edu; Wertepny, Douglas E., E-mail: wertepny.1@osu.edu

    2014-05-15

    We study the properties of the cross section for two-gluon production in heavy–light ion collisions derived in our previous paper [1] in the saturation/Color Glass Condensate framework. Concentrating on the energy and geometry dependence of the corresponding correlation functions we find that the two-gluon correlator is a much slower function of the center-of-mass energy than the one- and two-gluon production cross sections. The geometry dependence of the correlation function leads to stronger azimuthal near- and away-side correlations in the tip-on-tip U+U collisions than in the side-on-side U+U collisions, an exactly opposite behavior from the correlations generated by the elliptic flow of the quark–gluon plasma: a study of azimuthal correlations in the U+U collisions may thus help to disentangle the two sources of correlations. We demonstrate that the cross section for two-gluon production in heavy–light ion collisions contains a power-law infrared (IR) divergence even for fixed produced gluon momenta: while saturation effects in the target regulate some of the power-law IR-divergent terms in the lowest-order expression for the two-gluon correlator, other power-law IR-divergent terms remain, possibly due to absence of saturation effects in the dilute projectile. Finally we rewrite our result for the two-gluon production cross-section in a k{sub T}-factorized form, obtaining a new factorized expression involving a convolution of one- and two-gluon Wigner distributions over both the transverse momenta and impact parameters. We show that the two-gluon production cross-section depends on two different types of unintegrated two-gluon Wigner distribution functions.

  9. Two-gluon correlations in heavy-light ion collisions: Energy and geometry dependence, IR divergences, and kT-factorization

    Science.gov (United States)

    Kovchegov, Yuri V.; Wertepny, Douglas E.

    2014-05-01

    We study the properties of the cross section for two-gluon production in heavy-light ion collisions derived in our previous paper [1] in the saturation/Color Glass Condensate framework. Concentrating on the energy and geometry dependence of the corresponding correlation functions we find that the two-gluon correlator is a much slower function of the center-of-mass energy than the one- and two-gluon production cross sections. The geometry dependence of the correlation function leads to stronger azimuthal near- and away-side correlations in the tip-on-tip U+U collisions than in the side-on-side U+U collisions, an exactly opposite behavior from the correlations generated by the elliptic flow of the quark-gluon plasma: a study of azimuthal correlations in the U+U collisions may thus help to disentangle the two sources of correlations. We demonstrate that the cross section for two-gluon production in heavy-light ion collisions contains a power-law infrared (IR) divergence even for fixed produced gluon momenta: while saturation effects in the target regulate some of the power-law IR-divergent terms in the lowest-order expression for the two-gluon correlator, other power-law IR-divergent terms remain, possibly due to absence of saturation effects in the dilute projectile. Finally we rewrite our result for the two-gluon production cross-section in a kT-factorized form, obtaining a new factorized expression involving a convolution of one- and two-gluon Wigner distributions over both the transverse momenta and impact parameters. We show that the two-gluon production cross-section depends on two different types of unintegrated two-gluon Wigner distribution functions.

  10. Presenting a new kinetic model for methanol to light olefins reactions over a hierarchical SAPO-34 catalyst using the Langmuir–Hinshelwood–Hougen–Watson mechanism

    Science.gov (United States)

    Javad Azarhoosh, Mohammad; Halladj, Rouein; Askari, Sima

    2017-10-01

    In this study, a new kinetic model for methanol to light olefins (MTO) reactions over a hierarchical SAPO-34 catalyst using the Langmuir–Hinshelwood–Hougen–Watson (LHHW) mechanism was presented and the kinetic parameters was obtained using a genetic algorithm (GA) and genetic programming (GP). Several kinetic models for the MTO reactions have been presented. However, due to the complexity of the reactions, most reactions are considered lumped and elementary, which cannot be deemed a completely accurate kinetic model of the process. Therefore, in this study, the LHHW mechanism is presented as kinetic models of MTO reactions. Because of the non-linearity of the kinetic models and existence of many local optimal points, evolutionary algorithms (GA and GP) are used in this study to estimate the kinetic parameters in the rate equations. Via the simultaneous connection of the code related to modelling the reactor and the GA and GP codes in the MATLAB R2013a software, optimization of the kinetic models parameters was performed such that the least difference between the results from the kinetic models and experiential results was obtained and the best kinetic parameters of MTO process reactions were achieved. A comparison of the results from the model with experiential results showed that the present model possesses good accuracy.

  11. Presenting a new kinetic model for methanol to light olefins reactions over a hierarchical SAPO-34 catalyst using the Langmuir-Hinshelwood-Hougen-Watson mechanism.

    Science.gov (United States)

    Azarhoosh, Mohammad Javad; Halladj, Rouein; Askari, Sima

    2017-10-25

    In this study, a new kinetic model for methanol to light olefins (MTO) reactions over a hierarchical SAPO-34 catalyst using the Langmuir-Hinshelwood-Hougen-Watson (LHHW) mechanism was presented and the kinetic parameters was obtained using a genetic algorithm (GA) and genetic programming (GP). Several kinetic models for the MTO reactions have been presented. However, due to the complexity of the reactions, most reactions are considered lumped and elementary, which cannot be deemed a completely accurate kinetic model of the process. Therefore, in this study, the LHHW mechanism is presented as kinetic models of MTO reactions. Because of the non-linearity of the kinetic models and existence of many local optimal points, evolutionary algorithms (GA and GP) are used in this study to estimate the kinetic parameters in the rate equations. Via the simultaneous connection of the code related to modelling the reactor and the GA and GP codes in the MATLAB R2013a software, optimization of the kinetic models parameters was performed such that the least difference between the results from the kinetic models and experiential results was obtained and the best kinetic parameters of MTO process reactions were achieved. A comparison of the results from the model with experiential results showed that the present model possesses good accuracy.

  12. Visible light emitting Ln{sup 3+} ion (Ln=Sm, Eu and Dy) as a structural probe: A case study with SrZrO{sub 3}

    Energy Technology Data Exchange (ETDEWEB)

    Gupta, Santosh K., E-mail: santufrnd@gmail.com [Radiochemistry Division, Bhabha Atomic Research Centre (India); Yadav, A.K.; Bhattacharya, D.; Jha, S.N. [Atomic and Molecular Physics Division, Bhabha Atomic Research Centre Trombay, Mumbai 400085 (India); Natarajan, V. [Radiochemistry Division, Bhabha Atomic Research Centre (India)

    2015-08-15

    Undoped and various rare earth ion doped SrZrO{sub 3} (SZO) perovskite based phosphors have been synthesized using the gel-combustion technique employing citric acid as a fuel. The phase purity of the sample is confirmed by the X-ray diffraction (XRD) technique. It was observed that average particle size of perovskite particle was around 100 nm. In order to probe the local structure and symmetry around lanthanide ions in SrZrO{sub 3}, detailed experimental investigation has been carried out. X-ray absorption near edge fine (XANES) measurements along with their respective emission spectroscopy confirm that on doping lanthanide ion; in cases they were found to get stabilized as trivalent species. Extensive time resolved emission spectroscopy (TRES) on doped samples shows that on doping Sm{sup 3+} in SZO; an efficient energy transfer takes place and Sm{sup 3+} ions are localized both in Sr and Zr positions of SZO. PL decay time shows the presence of two life time values in case of nanocrystalline SrZrO{sub 3}:Sm{sup 3+}: (i) Sm{sup 3+} at Zr{sup 4+} site (τ=500 µs) and (ii) Sm{sup 3+} at Sr{sup 2+} site (τ=1.2 ms) in the ratio of 3:1. Based on TRES for europium doped sample, it was inferred that, two different types of Eu{sup 3+} ions were present in the SZO matrix. The first type was a long lived species present at relatively higher symmetric site of 'Sr{sup 2+}' and the second was a short lived species present at relatively lower symmetric 'Zr{sup 4+}' site which gets selectively excited at 296 nm. Dysprosium ion specifically occupies Zr{sup 4+} site only in SZO. EXAFS studies supported the TRES results. - Highlights: • Site occupancy of lanthanide. • Time resolved emission is explored. • XANES is used for oxidation state determination. • EXAFS for local structure investigation.

  13. Light-cured dimethacrylate-based resins and their composites: comparative study of mechanical strength, water sorption and ion release

    Science.gov (United States)

    O’Donnell, J.N.R.; Langhorst, S.E.; Fow, M.D.; Antonucci, J.M.; Skrtic, D.

    2008-01-01

    This study explored how resin type affects selected physicochemical properties of complex methacrylate copolymers and their amorphous calcium phosphate (ACP)-filled and glass-filled composites. Two series of photo-polymerizable resin matrices were formulated employing 2,2-bis[p-(2’-hydroxy-3’-methacryloxypropoxy)phenyl]propane (Bis-GMA) or an ethoxylated bisphenol A dimethacrylate (EBPADMA) as the base monomer, Unfilled copolymers and composites filled with a mass fraction with 40 %, 35 % and 30 %, respectively, of ACP or the un-silanized glass were assessed for biaxial flexure strength (BFS), water sorption (WS) and mineral ion release upon immersion in HEPES-buffered saline solution for up to six months. Substituting EBPADMA for Bis-GMA significantly reduced the WS while only marginally affected the BFS of both dry and wet copolymers. Independent of the filler level, both dry and wet ACP composites formulated with either BTHM or ETHM resins were mechanically weaker than the corresponding copolymers. The BFS of ACP composite specimens after 1 month in saline did not further decrease with further aqueous exposure. The BFS of glass-filled composites decreased with the increased level of the glass filler and the time of aqueous exposure. After 6 months of immersion, the BFS of glass-filled BTHM and ETHM composites, respectively, remained 58 % and 41 % higher than the BFS of the corresponding ACP composites. Ion release data indicated that a minimum mass fraction of 35 % ACP was required to attain the desired solution supersaturation with respect to hydroxyapatite for both the BTHM and ETHM derived composites. PMID:18607513

  14. The lighting of traffic tunnels. A paper presented at a meeting of the Shanghai Association for Science and Technology SAST, October 9 and October 12, 1987.

    NARCIS (Netherlands)

    Schreuder, D.A.

    1988-01-01

    The major problems for the lighting of tunnels concentrate in the daytime lighting for the first part of the tunnel directly following the entrance. The steady state theory of tunnel lighting as developed by Schreuder and Narisada, and the straylight- theory, developed by Adrian, are discussed. Th

  15. De novo assembly of Aureococcus anophagefferens transcriptomes reveals diverse responses to the low nutrient and low light conditions present during blooms

    Directory of Open Access Journals (Sweden)

    Kyle R. Frischkorn

    2014-07-01

    Full Text Available Transcriptome profiling was performed on four treatments of the harmful algal bloom-forming pelagophyte Aureococcus anophagefferens strain CCMP 1850 to assess responses to common stressors for dense phytoplankton blooms: low inorganic nitrogen concentrations, low inorganic phosphorus concentrations, low light levels, and a replete control. The de novo assemblies of pooled reads from all treatments reconstructed ~ 54,000 transcripts using Trinity, and ~ 31,000 transcripts using ABySS. Comparison to the strain CCMP 1984 genome showed that the majority of the gene models were present in both de novo assemblies and that roughly 95% of contigs from both assemblies mapped to the genome, with Trinity capturing slightly more genome content. Sequence reads were mapped back to the de novo assemblies as well as the gene models and differential expression was analyzed using a Bayesian approach called Analysis of Sequence Counts (ASC. On average, 93% of significantly upregulated transcripts recovered by genome mapping were present in the significantly upregulated pool from both de novo assembly methods. Transcripts related to the transport and metabolism of nitrogen were upregulated in the low nitrogen treatment, transcripts encoding enzymes that hydrolyze organic phosphorus or relieve arsenic toxicity were upregulated in the low phosphorus treatment, and transcripts for enzymes that catabolize organic compounds, restructure lipid membranes, or are involved in sulfolipid biosynthesis were upregulated in the low light treatment. A comparison of this transcriptome to the nutrient regulated transcriptional response of CCMP 1984 identified conserved responses between these two strains. These analyses reveal the transcriptional underpinnings of physiological shifts that could contribute to the ecological success of this species in situ: organic matter processing, metal detoxification, lipid restructuring, and photosynthetic apparatus turnover.

  16. Tight control of light trapping in surface addressable photonic crystal membranes: application to spectrally and spatially selective optical devices (Conference Presentation)

    Science.gov (United States)

    Letartre, Xavier; Blanchard, Cédric; Grillet, Christian; Jamois, Cécile; Leclercq, Jean-Louis; Viktorovitch, Pierre

    2016-04-01

    Surface addressable Photonic Crystal Membranes (PCM) are 1D or 2D photonic crystals formed in a slab waveguides where Bloch modes located above the light line are exploited. These modes are responsible for resonances in the reflection spectrum whose bandwidth can be adjusted at will. These resonances result from the coupling between a guided mode of the membrane and a free-space mode through the pattern of the photonic crystal. If broadband, these structures represent an ideal mirror to form compact vertical microcavity with 3D confinement of photons and polarization selectivity. Among numerous devices, low threshold VCSELs with remarkable and tunable modal properties have been demonstrated. Narrow band PCMs (or high Q resonators) have also been extensively used for surface addressable optoelectronic devices where an active material is embedded into the membrane, leading to the demonstration of low threshold surface emitting lasers, nonlinear bistables, optical traps... In this presentation, we will describe the main physical rules which govern the lifetime of photons in these resonant modes. More specifically, it will be emphasized that the Q factor of the PCM is determined, to the first order, by the integral overlap between the electromagnetic field distributions of the guided and free space modes and of the dielectric periodic perturbation which is applied to the homogeneous membrane to get the photonic crystal. It turns out that the symmetries of these distributions are of prime importance for the strength of the resonance. It will be shown that, by molding in-plane or vertical symmetries of Bloch modes, spectrally and spatially selective light absorbers or emitters can be designed. First proof of concept devices will be also presented.

  17. Mapping whole-brain activity with cellular resolution by light-sheet microscopy and high-throughput image analysis (Conference Presentation)

    Science.gov (United States)

    Silvestri, Ludovico; Rudinskiy, Nikita; Paciscopi, Marco; Müllenbroich, Marie Caroline; Costantini, Irene; Sacconi, Leonardo; Frasconi, Paolo; Hyman, Bradley T.; Pavone, Francesco S.

    2016-03-01

    Mapping neuronal activity patterns across the whole brain with cellular resolution is a challenging task for state-of-the-art imaging methods. Indeed, despite a number of technological efforts, quantitative cellular-resolution activation maps of the whole brain have not yet been obtained. Many techniques are limited by coarse resolution or by a narrow field of view. High-throughput imaging methods, such as light sheet microscopy, can be used to image large specimens with high resolution and in reasonable times. However, the bottleneck is then moved from image acquisition to image analysis, since many TeraBytes of data have to be processed to extract meaningful information. Here, we present a full experimental pipeline to quantify neuronal activity in the entire mouse brain with cellular resolution, based on a combination of genetics, optics and computer science. We used a transgenic mouse strain (Arc-dVenus mouse) in which neurons which have been active in the last hours before brain fixation are fluorescently labelled. Samples were cleared with CLARITY and imaged with a custom-made confocal light sheet microscope. To perform an automatic localization of fluorescent cells on the large images produced, we used a novel computational approach called semantic deconvolution. The combined approach presented here allows quantifying the amount of Arc-expressing neurons throughout the whole mouse brain. When applied to cohorts of mice subject to different stimuli and/or environmental conditions, this method helps finding correlations in activity between different neuronal populations, opening the possibility to infer a sort of brain-wide 'functional connectivity' with cellular resolution.

  18. Kidney failure as an unusual initial presentation of biclonal gammopathy (IgD multiple myeloma associated with light chain disease: A case report

    Directory of Open Access Journals (Sweden)

    Rabrenović Violeta

    2015-01-01

    Full Text Available Introduction. Immunoglobulin D (IgD myeloma is a rare disease, about 2% of all myelomas, even rarer when accompanied with another multiple myeloma in biclonal gammopathy. We presented a case of biclonal gammopathy - associated manifestation of IgD myeloma and light chain disease in a patient who initially had renal failure. Case report. 37-year-old male approximately one month before hospitalization began to feel malaise and fatigue along with decreased urination. Laboratory analysis revealed azotemia. A dialysis catheter was placed and hemodialysis started. The patient was then admitted to our hospital for further tests and during admission, objective examination revealed pronounced paleness with hepatosplenomegaly and hypertension (170/95 mmHg. Laboratory analysis showed erythrocyte sedimentation rate 122 mm/h, expressed anemic syndrome (Hb 71 g/L and renal failure dialysis rank: creatinine 1,408 μmol/L, urea31.7 mmol/L. There was two M components in serum protein electrophoresis: IgD lambda and free light chain lambda. Proteinuria was nephrotic rank (5.4 g/24 h, whose electrophoresis revealed 2 M components - massive in α 2 fraction of 71%; 7% in the discrete β fraction, beta 2M /serum 110 mg/L, in urine 1.8 mg/L - extremely high; IgL kappa / lambda index 1 : 13 (reference value ratio 2 : 1. The findings pointed to double myeloma disease: IgD myeloma and Bence Jones lambda myeloma. Bone biopsy confirmed IgD myeloma lambda 100% infiltration medulla predominantly plasmablasts. The treatment continued with hemodialysis 3 times per week with chemotherapy protocol bortezomib, doxorubicin, dexamethasone. After 4 cycles of chemotherapy, there was a decrease of IgD, λ - light chains, reduction in proteinuria (1.03 g/24 h, so hemodialysis was reduced to once per week. Six months after treatment initiation the patient underwent autologous bone marrow transplantation. In a 2-year follow-up period double myeloma disease showed complete remission

  19. Microfabricated ion frequency standard

    Science.gov (United States)

    Schwindt, Peter; Biedermann, Grant; Blain, Matthew G.; Stick, Daniel L.; Serkland, Darwin K.; Olsson, III, Roy H.

    2010-12-28

    A microfabricated ion frequency standard (i.e. an ion clock) is disclosed with a permanently-sealed vacuum package containing a source of ytterbium (Yb) ions and an octupole ion trap. The source of Yb ions is a micro-hotplate which generates Yb atoms which are then ionized by a ultraviolet light-emitting diode or a field-emission electron source. The octupole ion trap, which confines the Yb ions, is formed from suspended electrodes on a number of stacked-up substrates. A microwave source excites a ground-state transition frequency of the Yb ions, with a frequency-doubled vertical-external-cavity laser (VECSEL) then exciting the Yb ions up to an excited state to produce fluorescent light which is used to tune the microwave source to the ground-state transition frequency, with the microwave source providing a precise frequency output for the ion clock.

  20. Complementary use of ion beam elastic backscattering and recoil detection analysis for the precise determination of the composition of thin films made of light elements

    Energy Technology Data Exchange (ETDEWEB)

    Climent-Font, A. [Departamento de Fisica Aplicada, Facultad de Ciencias, Universidad Autonoma de Madrid, Cantoblanco 28049, Madrid (Spain); Centro de Micro-Analisis de Materiales (CMAM), Universidad Autonoma de Madrid, Cantoblanco 28049, Madrid (Spain)], E-mail: acf@uam.es; Cervera, M.; Hernandez, M.J. [Departamento de Fisica Aplicada, Facultad de Ciencias, Universidad Autonoma de Madrid, Cantoblanco 28049, Madrid (Spain); Laboratorio de Microelectronica, Facultad de Ciencias, Universidad Autonoma de Madrid, Cantoblanco 28049, Madrid (Spain); Munoz-Martin, A. [Centro de Micro-Analisis de Materiales (CMAM), Universidad Autonoma de Madrid, Cantoblanco 28049, Madrid (Spain); Piqueras, J. [Departamento de Fisica Aplicada, Facultad de Ciencias, Universidad Autonoma de Madrid, Cantoblanco 28049, Madrid (Spain); Laboratorio de Microelectronica, Facultad de Ciencias, Universidad Autonoma de Madrid, Cantoblanco 28049, Madrid (Spain)

    2008-04-15

    Rutherford backscattering spectrometry (RBS) is a well known powerful technique to obtain depth profiles of the constituent elements in a thin film deposited on a substrate made of lighter elements. In its standard use the probing beam is typically 2 MeV He. Its capabilities to obtain precise composition profiles are severely diminished when the overlaying film is made of elements lighter than the substrate. In this situation the analysis of the energy of the recoiled element from the sample in the elastic scattering event, the ERDA technique may be advantageous. For the detection of light elements it is also possible to use beams at specific energies producing elastic resonances with these light elements to be analyzed, with a much higher scattering cross sections than the Rutherford values. This technique may be called non-RBS. In this work we report on the complementary use of ERDA with a 30 MeV Cl beam and non-RBS with 1756 keV H ions to characterize thin films made of boron, carbon and nitrogen (BCN) deposited on Si substrates.

  1. Adsorption of Pb(II) ions present in aqueous solution on the oxy hydroxides: boehmite (γ-AIOOH), goethite (α-FeOOH) and manganite (γ-MnOOH); Adsorcion de iones Pb(II) presentes en solucion acuosa sobre los oxihidroxidos: boehmita (γ-AlOOH), goetita (α-FeOOH) y manganita (γ-MnOOH)

    Energy Technology Data Exchange (ETDEWEB)

    Arreola L, J. E.

    2013-07-01

    Boehmite, goethite and manganite were synthesized by different methods and characterized using X-ray diffraction (XRD), infrared spectroscopy (IR), thermogravimetric study , N{sub 2} physisorption measurements, scanning electron microscopy (Sem), semiquantitative elemental analysis (EDS), as well as additional studies were determined the surface active sites concentration and zero point of charge. Furthermore, we studied the Pb(II) ion adsorption capacity present in aqueous solution on these synthesized materials by batch-type experiments at room temperature, as a function of contact time between the phases liquid-solid system (adsorption kinetics), initial concentration of the adsorbate (adsorption isotherms), ph and temperature. The adsorption equilibrium time of adsorption processes in these studied systems was found at 60 minutes for boehmite and 30 minutes for goethite and manganite respectively after contacting the solid-liquid phase systems. The adsorption capacity of the lead ions on these adsorbent materials depended of lead concentration, ph and temperature of the systems. Were evaluated lead adsorption capacities in these materials to different contact times using an initial concentration of 20 mg/L of Pb(II) ions at ph = 4, the results of three systems were adjusted to second pseudo kinetic model order. With respect to the study of the adsorbate concentration effect, boehmite-Pb(II) and goethite-Pb(II) systems were adjusted to Langmuir isotherm model which proposes that the adsorption is carried out in a monolayer, moreover manganite-Pb(II) system was adjusted Temp kin isotherm model, which assumes that the adsorption heat of all the molecules in the layer decreases linearly with coverage due to adsorbent-adsorbate interactions and adsorption is characterized by a uniform distribution of the binding energies. Were studied the ph effect of Pb(II) ions solution on the adsorption capacity of such adsorbents, it was found that as the ph increases lead

  2. Gelling process of sodium alginate with bivalent ions rich microsphere: Nature of bivalent ions

    Science.gov (United States)

    Mauri, Marco; Vicini, Silvia; Castellano, Maila

    2016-05-01

    In the paper we present a new approach for obtaining a controlled gelling process of sodium alginate, based on the quantity of bivalent ions rich alginate micro-beads added as crosslinkers. Typically, calcium ions are used in gelation of alginate solutions. In this study we present different gelling systems realized with alginate microspheres, made by electrospinning methodology, enriched with different bivalent ions (Ca2+, Ba2+ and Mg2+). The microspheres were characterized under the point of view of the morphology by OM and as the ions content. Realized gels were characterized in light of the amount of the ions added to the alginate solution, and in light of the different dimensions of the micro-beads, using rheological measurements to assess the variation in the storage modulus (G'), loss modulus (G″) and complex viscosity (η*).

  3. A techno-economic analysis and optimization of Li-ion batteries for light-duty passenger vehicle electrification

    Science.gov (United States)

    Sakti, Apurba; Michalek, Jeremy J.; Fuchs, Erica R. H.; Whitacre, Jay F.

    2015-01-01

    We conduct a techno-economic analysis of Li-ion NMC-G prismatic pouch battery and pack designs for electric vehicle applications. We develop models of power capability and manufacturing operations to identify the minimum cost cell and pack designs for a variety of plug-in hybrid electric vehicle (PHEV) and battery electric vehicle (BEV) requirements. We find that economies of scale in battery manufacturing are reached quickly at a production volume of ∼200-300 MWh annually. Increased volume does little to reduce unit costs, except potentially indirectly through factors such as experience, learning, and innovation. We also find that vehicle applications with larger energy requirements are able to utilize cheaper cells due in part to the use of thicker electrodes. The effect on cost can be substantial. In our base case, we estimate pack-level battery production costs of ∼545 kWh-1 for a PHEV with a 10 mile (16 km) all-electric range (PHEV10) and ∼230 kWh-1 for a BEV with a 200 mile (320 km) all-electric range (BEV200). This 58% reduction, from 545 kWh-1 to 230 kWh-1, is a larger effect than the uncertainty represented by our optimistic and pessimistic scenarios. Electrodes thicker than about 100 or 125 microns are not currently used in practice due to manufacturing and durability concerns, but relaxing this constraint could further lower the cost of larger capacity BEV200 packs by up to an additional 8%.

  4. Light-Weight Free-Standing Carbon Nanotube-Silicon Films for Anodes of Lithium Ion Batteries

    KAUST Repository

    Cui, Li-Feng

    2010-07-27

    Silicon is an attractive alloy-type anode material because of its highest known capacity (4200 mAh/g). However, lithium insertion into and extraction from silicon are accompanied by a huge volume change, up to 300%, which induces a strong strain on silicon and causes pulverization and rapid capacity fading due to the loss of the electrical contact between part of silicon and current collector. Si nanostructures such as nanowires, which are chemically and electrically bonded to the current collector, can overcome the pulverization problem, however, the heavy metal current collectors in these systems are larger in weight than Si active material. Herein we report a novel anode structure free of heavy metal current collectors by integrating a flexible, conductive carbon nanotube (CNT) network into a Si anode. The composite film is free-standing and has a structure similar to the steel bar reinforced concrete, where the infiltrated CNT network functions as both mechanical support and electrical conductor and Si as a high capacity anode material for Li-ion battery. Such free-standing film has a low sheet resistance of ∼30 Ohm/sq. It shows a high specific charge storage capacity (∼2000 mAh/g) and a good cycling life, superior to pure sputtered-on silicon films with similar thicknesses. Scanning electron micrographs show that Si is still connected by the CNT network even when small breaking or cracks appear in the film after cycling. The film can also "ripple up" to release the strain of a large volume change during lithium intercalation. The conductive composite film can function as both anode active material and current collector. It offers ∼10 times improvement in specific capacity compared with widely used graphite/copper anode sheets. © 2010 American Chemical Society.

  5. Solution processing of organic light emitting diodes: Presentation held at 9th International Symposium on Flexible Organic Electronics, ISFOE 2016, 04-07 July 2016, Thessaloniki

    OpenAIRE

    Boeffel, Christine; Kröpke, Stefan; Lange, Alexander; Wedel, Armin; Kim, Yohan

    2016-01-01

    Organic light emitting diodes (OLEDs) are often classified as a new generation of displays and lighting elements and have been the focus of research of development for over 20 years. The first products have been introduced into the market in applications such as displays for smart phones or TVs as well as solid state lighting. Typcially, most commercial products are produced via vacuum evaporation technologies. However, solution processing techniques for the production of OLEDs have a high po...

  6. Microwave-assisted aqueous synthesis of transition metal ions doped ZnSe/ZnS core/shell quantum dots with tunable white-light emission

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Jie [Laboratory of Advanced Materials, Fudan University, Shanghai 200438 (China); Chen, Qiuhang; Zhang, Wanlu; Mei, Shiliang; He, Liangjie; Zhu, Jiatao [Engineering Research Center of Advanced Lighting Technology, Ministry of Education, Institute for Electric Light Sources, Fudan University, Shanghai 200433 (China); Chen, Guoping [School of Information Science and Technology, Fudan University, Shanghai 200433 (China); Guo, Ruiqian, E-mail: rqguo@fudan.edu.cn [Engineering Research Center of Advanced Lighting Technology, Ministry of Education, Institute for Electric Light Sources, Fudan University, Shanghai 200433 (China)

    2015-10-01

    Highlights: • ZnSe-based QDs were formed via a microwave-assisted aqueous approach. • The stabilizer, ZnS coats and UV irradiation played a role in the PL enhancement. • Tunable white-light-emitting Mn:ZnSe QDs and Cu,Mn:ZnSe/ZnS QDs were synthesized. • The formation mechanism of Cu,Mn:ZnSe QDs was clarified. • The corresponding CIE color coordinates of different PL spectra were obtained. - Abstract: Synthesis of bright white-light emitting Mn and Cu co-doped ZnSe/ZnS core/shell quantum dots (QDs) (Cu,Mn:ZnSe/ZnS) was reported. Water-soluble ZnSe-based QDs with Mn and Cu doping were prepared using a versatile hot-injection method in aqueous solution with a microwave-assisted approach. Influence of the Se/S ratio, stabilizer, refluxing time and the concentration of Cu/Mn dopant ions on the particle size and photoluminescence (PL) were investigated. The as-prepared QDs in the different stages of growth were characterized by X-ray powder diffractometer (XRD), high-resolution transmission electron microscopy (HRTEM), UV–visible (UV–vis) spectrophotometer, and fluorescence spectrophotometer. It is found that these ZnSe-based QDs synthesized under mild conditions exhibit emission in the range of 390–585 nm. The PL quantum yield (QY) of the as-prepared water-soluble ZnSe QDs can be up to 24.3% after the UV-irradiation treatment. The band-gap emission of ZnSe is effectively restrained through Mn and Cu doping. The refluxing time influences the doping of not only Mn, but also Cu, which leads to the best refluxing time of Mn:ZnSe and the red-shift of the emission of Cu:ZnSe d-dots. Co-doping induced white-light emission (WLE) from Cu,Mn:ZnSe/ZnS core/shell QDs were obtained, which can offer the opportunity for future-generation white-light emitting diodes (LEDs)

  7. Spectroscopy of Ferric Heme and Protoporphyrin IX Ions In Vacuo

    DEFF Research Database (Denmark)

    Wyer, Jean; Nielsen, Steen Brøndsted

    2013-01-01

    This chapter deals with gas-phase spectroscopy of protoporphyrin IX and heme ions, two important biochromophores in nature. These ions strongly absorb blue and green light, which accounts for e.g. the red colour of blood. We present absorption spectra of four-coordinate ferric heme cations at room...

  8. Efficient removal of radioactive iodide ions from water by three-dimensional Ag{sub 2}O–Ag/TiO{sub 2} composites under visible light irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Shuaishuai; Wang, Na; Zhang, Yuchang; Li, Yaru [School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072 (China); Han, Zhuo [CECEP Environmental Protection Investment Development Co., Ltd., Jiangxi 3300969 (China); Na, Ping, E-mail: naping@tju.edu.cn [School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072 (China); Tianjin Co-Innovation Center of Chemical Science and Engineering, Tianjin 300072 (China)

    2015-03-02

    Highlights: • 3D Ag{sub 2}O–Ag/TiO{sub 2} composites have been synthesized through a facile method. • 3D Ag{sub 2}O–Ag/TiO{sub 2} composites exhibit large photocatalytic adsorption capacity, high selectivity, and excellent trace removal performance of I{sup −} under visible light. • 3D Ag{sub 2}O–Ag/TiO{sub 2} composites could be easily separated and regenerated. • The adsorption capacity of Ag{sub 2}O for I{sup −} is enlarged 4.4 times by the photooxidation of Ag/TiO{sub 2}. • The cooperative effects mechanism between Ag{sub 2}O and Ag/TiO{sub 2} is proposed and verified. - Abstract: Three-dimensional Ag{sub 2}O and Ag co-loaded TiO{sub 2} (3D Ag{sub 2}O–Ag/TiO{sub 2}) composites have been synthesized through a facile method, characterized using SEM, EDX, TEM, XRD, XPS, UV–vis DRS, BET techniques, and applied to remove radioactive iodide ions (I{sup −}). The photocatalytic adsorption capacity (207.6 mg/g) of the 3D Ag{sub 2}O–Ag/TiO{sub 2} spheres under visible light is four times higher than that in the dark, which is barely affected by other ions, even in simulated salt lake water where the concentration of Cl{sup −} is up to 590 times that of I{sup −}. The capability of the composites to remove even trace amounts of I{sup −} from different types of water, e.g., deionized or salt lake water, is demonstrated. The composites also feature good reusability, as they were separated after photocatalytic adsorption and still performed well after a simple regeneration. Furthermore, a mechanism explaining the highly efficient removal of radioactive I{sup −} has been proposed according to characterization analyses of the composites after adsorption and subsequently been verified by adsorption and desorption experiments. The proposed cooperative effects mechanism considers the interplay of three different phenomena, namely, the adsorption performance of Ag{sub 2}O for I{sup −}, the photocatalytic ability of Ag/TiO{sub 2} for oxidation

  9. Fast and complete degradation of Congo red under visible light with Er3+ and Nd3+ ions doped TiO2 nanocomposites

    Directory of Open Access Journals (Sweden)

    Himanshu Narayan

    2012-01-01

    Full Text Available We report fast and complete destruction of the dye Congo red (CR under visible light in the presence of Nd3+ and Er3+ doped TiO2 nanocomposites (NCs. TiO2 NCs with general composition TiO2[R2O3]x, {x=0.1, 0.2; R≡ Nd, Er} and particle size 12-16 nm were synthesized through co-precipitation/hydrolysis (CPH. A set of similar composites was also prepared through solid state reaction (SSR route, which produced 31- 47 nm particles. After characterization, visible light photocatalytic activity of all the samples was recorded for the degradation of CR. NCs with molar concentration x=0.2 of both doping types produced close to 100% degradation in 180 min. The apparent rate constant (kobs was found to be 2.91×10–2 min–1 and 2.36×10–2 min–1, for these Nd3+ and Er3+ doped NCs, respectively. The other NCs with x=0.1, also showed significant degradation of CR, but the samples prepared through SSR performed worse. The excellent degradation obtained with the NCs may be attributed to their small particle size. Moreover, the doping of Nd3+ and Er3+ ions further supported the photocatalysis through formation of intermediate energy levels within the band gap of TiO2. These new levels not only acted as electron traps for efficient suppression of the undesired e–/h+ recombination, but also facilitated to a certain extent the absorption of visible irradiation.

  10. WOW: light print, light propel, light point

    DEFF Research Database (Denmark)

    Glückstad, Jesper; Bañas, Andrew Rafael; Aabo, Thomas

    2012-01-01

    anywhere in a sample at any orientation using real-time 3D optical micromanipulation with six degrees of freedom. One of the key aspects of our demonstrated WOWs is the change in direction of in-coupled light and the marked increase in numerical aperture of the out-coupled light. Hence, each light...... propelled WOW can tap from a relatively broad incident beam and generate a much more tightly confined light at its tip. The presentation contains both numerical simulations related to the propagation of light through a WOW and preliminary experimental demonstrations on our BioPhotonics Workstation...

  11. Treatment of refractory seizures due to a benign mass present in the corpus callosum with an ion magnetic inductor: case report.

    Science.gov (United States)

    Mihajlovic-Madzarevic, Vera; Pappas, Panos

    2005-01-01

    A 39-year-old female patient was having episodes of body stiffness that affected her motor abilities. A lipoma in the corpus callosum was identified by computed tomography. Her condition deteriorated rapidly, and seizures were refractory to any treatment. Seizure frequency and severity increased, incapacitating the patient completely. When seizure control was not achieved by any other treatment, the patient decided to undergo experimental therapy with the ion magnetic inductor. Treatment with the ion magnetic inductor notably reduced the seizure frequency and intensity. After treatment the patient was able to return to work and other normal activities. The long-term effects are not yet known, but there have been no adverse events to date. The patient is still undergoing ion magnetic inductor treatment daily in the same way other epileptic patients must continue with the use of antiepileptic drugs for life. There is evidence in the literature that other types of electromagnetic therapy, such as repetitive transcranial magnetic stimulation (rTMS), may be useful for treating refractory seizures. The potential advantage of the ion magnetic inductor over rTMS is that there is no need to locate precisely the epileptogenic focus, making the treatment procedure simpler and faster.

  12. Using the Larval Zebrafish Locomotor Asssay in Functional Neurotoxicity Screening: Light Brightness and the Order of Stimulus Presentation Affect the Outcome

    Science.gov (United States)

    We are evaluating methods to screen/prioritize large numbers of chemicals using 6 day old zebrafish (Danio rerio) as an alternative model for detecting neurotoxic effects. Our behavioral testing paradigm simultaneously tests individual larval zebrafish under sequential light and...

  13. ITO films realized at room-temperature by ion beam sputtering for high-performance flexible organic light-emitting diodes

    Energy Technology Data Exchange (ETDEWEB)

    Lucas, B.; Rammal, W.; Moliton, A. [Limoges Univ., Faculte des Sciences et Techniques, CNRS, UMR 6172, Institut de Recherche XLIM, Dept. MINACOM, 87 - Limoges (France)

    2006-06-15

    Indium-tin oxide (ITO) thin layers are obtained by an IBS (Ion Beam Sputtering) deposition process. We elaborated ITO films on flexible substrates of polyethylene terephthalate (PET), under soft conditions of low temperatures and fulfilling the requirements of fabrication processes of the organic optoelectronic components. With a non thermally activated (20 Celsius degrees) ITO deposition assisted by an oxygen flow (1 cm{sup 3}/min), we got an optical transmittance of 90% in the visible range, a resistivity around 10{sup -3} {omega}.cm and a surface roughness lower than 1.5 mm. Thus we realized flexible organic light-emitting diodes (FOLEDs) with good performances: a maximum luminance of 12000 cd/m{sup 2} at a voltage of 19 V and a maximum luminous power efficiency around 1 lm/W at a voltage of 10 V (or a maximum current efficiency of 4 cd/A at 14 V) for the (PET(50 {mu}m) / ITO(200 nm) / TPD(40 nm) / Alq3(60 nm) / Ca / Al) structure. (authors)

  14. Kinetic Monte Carlo simulation of the efficiency roll-off, emission color, and degradation of organic light-emitting diodes (Presentation Recording)

    Science.gov (United States)

    Coehoorn, Reinder; van Eersel, Harm; Bobbert, Peter A.; Janssen, Rene A. J.

    2015-10-01

    The performance of Organic Light Emitting Diodes (OLEDs) is determined by a complex interplay of the charge transport and excitonic processes in the active layer stack. We have developed a three-dimensional kinetic Monte Carlo (kMC) OLED simulation method which includes all these processes in an integral manner. The method employs a physically transparent mechanistic approach, and is based on measurable parameters. All processes can be followed with molecular-scale spatial resolution and with sub-nanosecond time resolution, for any layer structure and any mixture of materials. In the talk, applications to the efficiency roll-off, emission color and lifetime of white and monochrome phosphorescent OLEDs [1,2] are demonstrated, and a comparison with experimental results is given. The simulations show to which extent the triplet-polaron quenching (TPQ) and triplet-triplet-annihilation (TTA) contribute to the roll-off, and how the microscopic parameters describing these processes can be deduced properly from dedicated experiments. Degradation is treated as a result of the (accelerated) conversion of emitter molecules to non-emissive sites upon a triplet-polaron quenching (TPQ) process. The degradation rate, and hence the device lifetime, is shown to depend on the emitter concentration and on the precise type of TPQ process. Results for both single-doped and co-doped OLEDs are presented, revealing that the kMC simulations enable efficient simulation-assisted layer stack development. [1] H. van Eersel et al., Appl. Phys. Lett. 105, 143303 (2014). [2] R. Coehoorn et al., Adv. Funct. Mater. (2015), publ. online (DOI: 10.1002/adfm.201402532)

  15. Fabrication and characterization of p-ZnO:(P,N)/n-ZnO:Al homojunction ultra-violet (UV) light emitting diodes (Presentation Recording)

    Science.gov (United States)

    Rafiudeen, Amiruddin; Reddy, T. Srinivasa; Cheemadan, Shaheer; Kumar, M. C. Santhosh

    2015-10-01

    ZnO possess distinctive characteristics such as low cost, wide band gap (3.36 eV) and large exciton binding energy (60meV). As the band gap lies in ultra violet (UV) region, ZnO is considered as a novel material for the fabrication of ultra violet light emitting diodes (UV-LEDs). However, ZnO being intrinsic n-type semiconductor the key challenge lies in realization of stable and reproducible p-type ZnO. In the present research dual acceptor group-V elements such as P and N are simultaneously doped in ZnO films to obtain the p-type characteristics. The deposition is made by programmable spray pyrolysis technique upon glass substrates at 697K. The optimum doping concentration of P and N were found to be 0.75 at% which exhibits hole concentration of 4.48 x 10^18 cm-3 and resistivity value of 9.6 Ω.cm. The deposited p-ZnO were found to be stable for a period over six months. Highly conducting n-type ZnO films is made by doping aluminum (3 at%) which exhibits higher electron concentration of 1.52 x 10^19 cm-3 with lower electrical resistivity of 3.51 x 10-2 Ω.cm. The structural, morphological, optical and electrical properties of the deposited n-ZnO and p-ZnO thin films are investigated. An efficient p-n homojunction has been fabricated using the optimum p-ZnO:(P,N) and n-ZnO:Al layers. The current-voltage (I-V) characteristics show typical rectifying characteristics of p-n junction with a low turn on voltage. Electroluminescence (EL) studies reveals the fabricated p-n homojunction diodes exhibits strong emission features in ultra-violet (UV) region around 378 nm.

  16. Over the light of darkness: memory and present meanings in anonymous visual heaps Sobre a luz da escuridão: memória e sentidos presentes em acervos visuais anônimos

    Directory of Open Access Journals (Sweden)

    Edson Luiz da Silva Viera

    2011-08-01

    Full Text Available This research presents some reflections about the actions developed by the project “Revelações da História” (History Revelation, an initiative constituted by photograph researchers in the city of Londrina (Paraná State, Brazil, between the years of 2005 and 2008, that resulted in the identification, formation, re-integration and diffusion of anonymous visual heaps, as well as the publishing of two books that inserted in Londrina´s community inedited visual collections: the Foto Estrela´s and the Armínio Kaiser´s heaps. Some reflections about fragments of these photographic collections were made in order to enlarge and to consolidate the importance of this preservation initiative starting from some contents not explored by the project “Revelações da História”. The theoretical discussions were made under the light of concepts from Vilém Flüsser philosophy, the linguistic theory of Mikhail Bakhtin and the French line of semiotics theory. The research also ratifies the importance of these heaps to the constitution of a visual memory about “sceneries and characters in Brazil” and about the building of social history as the researcher Boris Kossoy proposes. Moreover, the main lines of action from the project “Revelações da História” also were presented in relation to the theoretical bases, methods and instruments that have guided it, intending to be a reference to future projects of the same type. The results presented at this research ratify the importance and the value of the lightening up and democratization of anonymous pho tographic heaps to the universe of the knowledge. Esta pesquisa apresenta algumas reflexões em torno das ações realizadas pelo projeto “Revelações da História”, iniciativa constituída por pesquisadores da fotografia na cidade de Londrina, realizado entre 2005 e 2008, que resultou na identificação, formação, reintegração e difusão de acervos visuais anônimos, bem como na publica

  17. Probing of surface Eu{sup 3+} ions present in ZnO:Eu nanoparticles by covering ZnO:Eu core with Y{sub 2}O{sub 3} shell: Luminescence study

    Energy Technology Data Exchange (ETDEWEB)

    Singh, L. Robindro [Department of Physics, Manipur University, Canchipur 795003 (India)], E-mail: robindro001@yahoo.co.in; Ningthoujam, R.S. [Chemistry Division, Bhabha Atomic Research Centre, Mumbai 400085 (India)], E-mail: rsn@barc.gov.in; Sudarsan, V. [Chemistry Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Singh, S. Dorendrajit [Department of Physics, Manipur University, Canchipur 795003 (India); Kulshreshtha, S.K. [Chemistry Division, Bhabha Atomic Research Centre, Mumbai 400085 (India)

    2008-09-15

    Eu{sup 3+} doped ZnO nanoparticles are known to have significance extent of surface Eu{sup 3+} ions due to a large difference in ionic radii. Effect of such Eu{sup 3+} ions on the luminescence properties of ZnO:Eu nanoparticles has been understood from the luminescence studies of ZnO:Eu nanoparticles covered with Y{sub 2}O{sub 3} shell. Based on the asymmetric ratio of luminescence and extent of energy transfer, it is established that when ZnO:Eu nanoparticles are covered with Y{sub 2}O{sub 3} shell, a part of Eu{sup 3+} ions present with ZnO:Eu core migrate to Y{sub 2}O{sub 3} shell and occupy Y{sup 3+} lattice positions.

  18. The lighting of residential yards. Paper presented at the 19th Session of the Commission Internationale de l'Eclairage (CIE), Kyoto, Japan, 1979.

    NARCIS (Netherlands)

    Schreuder, D.A.

    1979-01-01

    The "woonerf" is conceived in order to enhance the amenity in residential districts. It is put into effect by a series of legal measures, road construction and traffic management measures, planning measures and social measures. The quality requirements for the public lighting include apart of

  19. The lighting of residential yards. Paper presented at the 19th Session of the Commission Internationale de l'Eclairage (CIE), Kyoto, Japan, 1979.

    NARCIS (Netherlands)

    Schreuder, D.A.

    1979-01-01

    The "woonerf" is conceived in order to enhance the amenity in residential districts. It is put into effect by a series of legal measures, road construction and traffic management measures, planning measures and social measures. The quality requirements for the public lighting include apart of amenit

  20. Study of Light Ion Collisions

    CERN Multimedia

    2002-01-01

    Inelastic and elastic pd, dd, p@a and @a@a interactions are studied at a nucleon-nucleon cm energy @]s^n^n = 31~GeV using the Split-Field-Magnet detector. The two forward telescopes have been upgraded by two calorimeters to tag spectator neutrons and by two MWPCs for improved detection of charged nuclear fragments. Several selective triggers are planned in addition to the minimum-bias trigger: 1) high p^t single hadron at 10|0, 20|0 and 45|0; 2) central particle production together with unfragmented projectiles; 3) nuclear break-up without particle production; 4) elastic interactions. This experiment is an extension of the @a-run in 1980; the new one will benefit from the direct comparisons of @a@a, dd, @ap and dp interactions; from expected higher integrated luminosity for @a@a interactions; the upgrading of the spectator tagging capability and the new high p^t triggers installed by R41

  1. Clustering effects and decay analysis of the light-mass N =Z and N ≠Z composite systems formed in heavy ion collisions

    Science.gov (United States)

    Kaur, Manpreet; Singh, BirBikram; Patra, S. K.; Gupta, Raj K.

    2017-01-01

    We investigate the clustering effects in light mass N =Z and N ≠Z composite systems *20Ne, *28Si, *40Ca and Ne,22*21, *39K, respectively, formed in low-energy heavy ion reactions at different excitation energies, within the collective clusterization approach of the dynamical cluster-decay model (DCM) of Gupta and collaborators based on quantum-mechanical fragmentation theory (QMFT). Considering quadrupole deformed and compact orientated nuclei, a comparative decay analysis of these systems has been undertaken for the emission of different intermediate mass fragments (IMFs) or clusters, specifically the IMFs having Z =3 , 4, and 5 (or Z =7 , 6, and 5 complimentary fragments from the *20Ne and Ne,22*21 composite systems) which are having the experimental data available for their Z distribution. Quite interestingly, the QMFT supports clustering in N =Z (*20Ne and *28Si) and N ≠Z (*21Ne and *22Ne) nuclear systems at excitation energies corresponding to their respective decay threshold or resonant-state energies for the 4 α , 16O cluster and non-α cluster 14C (more so in *22NeN ≠Z composite system), supported by the Ikeda diagrams, taking into account the proper pairing strength in the temperature-dependent liquid drop energies. Within the DCM, we notice that at higher excitation energies in addition to x α -type (where x is an integer) clusters from N =Z composite systems and x n -x α -type clusters from N ≠Z composite systems, n p -x α -type clusters are relatively quite dominant, with larger preformation probability due to the decreased pairing strength at higher temperatures in the liquid drop energies. Also, the study reveals the presence of competing reaction mechanisms of compound nucleus (fusion-fission, FF) and of noncompound nucleus origin (deep inelastic orbiting, DIO) in the decay of very-light-mass composite systems *20,21,22Ne and *28Si at different excitation energies. The DIO contribution in the IMF cross section σIMF is extracted for these

  2. Radioactive Ion Beam Development at the Holifield Radioactive Ion Beam Facility

    CERN Document Server

    Stracener, Dan; Beene, James R; Bilheux, Hassina Z; Bilheux, Jean-Christophe; Blackmon, Jeff C; Carter, Ken; Dowling, Darryl; Juras, Raymond; Kawai, Yoko; Kronenberg, Andreas; Liu, Yuan; Meigs, Martha; Müller, Paul; Spejewski, Eugene H; Tatum, A

    2005-01-01

    Radioactive beams are produced at the Holifield Radioactive Ion Beam Facility (HRIBF) at Oak Ridge National Laboratory using the Isotope Separator On-Line (ISOL) technique. Radioactive nuclei are produced in a thick target via irradiation with energetic light ions (protons, deuterons, helium isotopes) and then post-accelerated to a few MeV/nucleon for use in nuclear physics experiments. An overview of radioactive beam development at the HRIBF will be presented, including ion source development, improvements in the ISOL production targets, and a description of techniques to improve the quality (intensity and purity) of the beams. Facilities for radioactive ion beam development include two ion source test facilities, a target/ion source preparation and quality assurance facility, and an in-beam test facility where low intensity production beams are used. A new test facility, the High Power Target Laboratory, will be available later this year. At this facility, high intensity production beams will be available t...

  3. Electron Beam Ion Sources

    CERN Document Server

    Zschornacka, G.; Thorn, A.

    2013-12-16

    Electron beam ion sources (EBISs) are ion sources that work based on the principle of electron impact ionization, allowing the production of very highly charged ions. The ions produced can be extracted as a DC ion beam as well as ion pulses of different time structures. In comparison to most of the other known ion sources, EBISs feature ion beams with very good beam emittances and a low energy spread. Furthermore, EBISs are excellent sources of photons (X-rays, ultraviolet, extreme ultraviolet, visible light) from highly charged ions. This chapter gives an overview of EBIS physics, the principle of operation, and the known technical solutions. Using examples, the performance of EBISs as well as their applications in various fields of basic research, technology and medicine are discussed.

  4. Public lighting : the effectiveness for road transport. Paper presented at Institution of Public Lighting Engineers IPLE Diamond Jubilee Conference 1984, University of York, 2-4 October 1984, proceedings, p. 67-72.

    NARCIS (Netherlands)

    Schreuder, D.A.

    1984-01-01

    Drivers have a dual task in traffic, the parts of which overlap only in part: to arrive at the destination of their trip, and to do so without collisions. One of the major functions of public lighting is to support traffic participants (drivers) in performing these tasks at night. An overall result

  5. Light metal production

    Science.gov (United States)

    Fan, Qinbai

    2016-04-19

    An electrochemical process for the production of light metals, particularly aluminum. Such a process involves contacting a light metal source material with an inorganic acid to form a solution containing the light metal ions in high concentration. The solution is fed to an electrochemical reactor assembly having an anode side containing an anode and a cathode side containing a cathode, with anode side and the cathode side separated by a bipolar membrane, with the solution being fed to the anode side. Light metal ions are electrochemically transferred through the bipolar membrane to the cathode side. The process further involves reducing the light metal ions to light metal powder. An associated processing system is also provided.

  6. Laser photodissociation and spectroscopy of mass-separated biomolecular ions

    CERN Document Server

    Polfer, Nicolas C

    2014-01-01

    This lecture notes book presents how enhanced structural information of biomolecular ions can be obtained from interaction with photons of specific frequency - laser light. The methods described in the book ""Laser photodissociation and spectroscopy of mass-separated biomolecular ions"" make use of the fact that the discrete energy and fast time scale of photoexcitation can provide more control in ion activation. This activation is the crucial process producing structure-informative product ions that cannot be generated with more conventional heating methods, such as collisional activation. Th

  7. Integrated optical addressing of an ion qubit.

    Science.gov (United States)

    Mehta, Karan K; Bruzewicz, Colin D; McConnell, Robert; Ram, Rajeev J; Sage, Jeremy M; Chiaverini, John

    2016-12-01

    The long coherence times and strong Coulomb interactions afforded by trapped ion qubits have enabled realizations of the necessary primitives for quantum information processing and the highest-fidelity quantum operations in any qubit to date. Although light delivery to each individual ion in a system is essential for general quantum manipulations and readout, experiments so far have employed optical systems that are cumbersome to scale to even a few tens of qubits. Here we demonstrate lithographically defined nanophotonic waveguide devices for light routing and ion addressing that are fully integrated within a surface-electrode ion trap chip. Ion qubits are addressed at multiple locations via focusing grating couplers emitting through openings in the trap electrodes to ions trapped 50 μm above the chip; using this light, we perform quantum coherent operations on the optical qubit transition in individual (88)Sr(+) ions. The grating focuses the beam to a diffraction-limited spot near the ion position with 2 μm 1/e(2) radius along the trap axis, and we measure crosstalk errors between 10(-2) and 4 × 10(-4) at distances 7.5-15 μm from the beam centre. Owing to the scalability of the planar fabrication technique employed, together with the tight focusing and stable alignment afforded by the integration of the optics within the trap chip, this approach presents a path to creating the optical systems required for large-scale trapped-ion quantum information processing.

  8. Integrated optical addressing of an ion qubit

    Science.gov (United States)

    Mehta, Karan K.; Bruzewicz, Colin D.; McConnell, Robert; Ram, Rajeev J.; Sage, Jeremy M.; Chiaverini, John

    2016-12-01

    The long coherence times and strong Coulomb interactions afforded by trapped ion qubits have enabled realizations of the necessary primitives for quantum information processing and the highest-fidelity quantum operations in any qubit to date. Although light delivery to each individual ion in a system is essential for general quantum manipulations and readout, experiments so far have employed optical systems that are cumbersome to scale to even a few tens of qubits. Here we demonstrate lithographically defined nanophotonic waveguide devices for light routing and ion addressing that are fully integrated within a surface-electrode ion trap chip. Ion qubits are addressed at multiple locations via focusing grating couplers emitting through openings in the trap electrodes to ions trapped 50 μm above the chip; using this light, we perform quantum coherent operations on the optical qubit transition in individual 88Sr+ ions. The grating focuses the beam to a diffraction-limited spot near the ion position with 2 μm 1/e2 radius along the trap axis, and we measure crosstalk errors between 10-2 and 4 × 10-4 at distances 7.5-15 μm from the beam centre. Owing to the scalability of the planar fabrication technique employed, together with the tight focusing and stable alignment afforded by the integration of the optics within the trap chip, this approach presents a path to creating the optical systems required for large-scale trapped-ion quantum information processing.

  9. Measurement of a 2D fast-ion velocity distribution function by tomographic inversion of fast-ion D-alpha spectra

    DEFF Research Database (Denmark)

    Salewski, Mirko; Geiger, B.; Jacobsen, Asger Schou

    2014-01-01

    We present the first measurement of a local fast-ion 2D velocity distribution function f(v‖, v⊥). To this end, we heated a plasma in ASDEX Upgrade by neutral beam injection and measured spectra of fast-ion Dα (FIDA) light from the plasma centre in three views simultaneously. The measured spectra ...

  10. Ion Sources for MedAustron

    CERN Document Server

    Lettry, J; Wallner, J; Sargsyan, E; CERN. Geneva. BE Department

    2010-01-01

    The MedAustron Ion therapy center will be constructed in Wiener Neustadt (Austria) in the vicinity of Vienna. Its accelerator complex consists of four ion sources, a linear accelerator, a synchrotron and a beam delivery system to the three medical treatment rooms and to the research irradiation room. The ion sources shall deliver beams of H31+, C4+ and light ions with utmost reliability and stability. This paper describes the features of the ion sources presently planned for the MedAustron facility; such as ion source main parameters, gas injection, temperature control and cooling systems. A dedicated beam diagnostics technique is proposed in order to characterize ECR ions beams; in the first drift region after the ion source, a fraction of the mixed beam is selected via moveable aperture. With standard beam diagnostics, we then aim to produce position-dependant observables such as ion-current density, beam energy distribution and emittance for each charge states to be compared to simulations of ECR e-heating...

  11. Micron-focused ion beamlets

    Science.gov (United States)

    Chowdhury, Abhishek; Bhattacharjee, Sudeep

    2010-05-01

    A multiple beam electrode system (MBES) is used to provide focused ion beamlets of elements from a compact microwave plasma. In this study, a honeycomb patterned plasma electrode with micron size apertures for extracting ion beamlets is investigated. The performance of the MBES is evaluated with the help of two widely adopted and commercially available beam simulation tools, AXCEL-INP and SIMION, where the input parameters are obtained from our experiments. A simple theoretical model based upon electrostatic ray optics is employed to compare the results of the simulations. It is found that the results for the beam focal length agree reasonably well. Different geometries are used to optimize the beam spot size and a beam spot ˜5-10 μm is obtained. The multiple ion beamlets will be used to produce microfunctional surfaces on soft matter like polymers. Additionally, the experimental set-up and plans are presented in the light of above applications.

  12. Photon interactions in ultra-peripheral heavy-ion collisions in ATLAS

    CERN Document Server

    Webb, Samuel; The ATLAS collaboration

    2017-01-01

    Presentation slides for the PHOTON 2017 conference at CERN. The presentation covers the analyses "Photo-nuclear dijet production in ultra-peripheral Pb+Pb collisions" (ATLAS-CONF-2017-011) and "Evidence for light-by-light scattering in heavy-ion collisions with the ATLAS detector at the LHC" (HION-2016-05)

  13. Presentations to the SuperHILAC Program Advisory Committee

    Energy Technology Data Exchange (ETDEWEB)

    McDonald, R.J. (ed.)

    1987-09-01

    This paper contains viewgraphs on the SuperHILAC. The topics of these viewgraphs are: light charged particle emission as a probe of heavy-ion reactions; correlated charged-changing interactions and x-ray emission in ion-atom collisions; progress report on Sassy II and new nuclear chemistry experiments at the SuperHILAC; precision x-ray spectroscopy of heavy ions; 180/sup 0/-correlated equal energy photons from 5.9 MeV/N U + Th collisions; research statement of excited states of monatomic and molecular systems; search for entrance-channel effects in the production of superdeformed nuclei; present and future research with OASIS; relaxation mechanisms in damped heavy-ion reactions; excitation energy division and nucleon transfer; test of QED and relativistic effects for strongly-bound electrons; heavy-ion Coulomb excitation and transfer reactions as probes of nuclear structure; and preliminary design of the Dilepton spectrometer.

  14. Comparison of Single-Event Transients Induced in an Operational Amplifier (LM124) by Pulsed Laser Light and a Broad Beam of Heavy Ions

    Science.gov (United States)

    Buchner, Steve; McMorrow, Dale; Poivey, Christian; Howard, James, Jr.; Pease, Rom; Savage, Mark; Boulghassoul, Younis; Massengill, Lloyd

    2003-01-01

    A comparison of transients from heavy-ion and pulsed-laser testing shows good agreement for many different voltage configurations. The agreement is illustrated by comparing directly individual transients and plots of transient amplitude versus width.

  15. Generation of heavy ion beams using high-intensity short pulse lasers

    Science.gov (United States)

    Petrov, George; McGuffey, Chris; Thomas, Alec; Krushelnick, Karl; Beg, Farhat

    2016-10-01

    A theoretical study of ion acceleration from high-Z material irradiated by intense sub-picosecond lasers is presented. The underlying physics of beam formation and acceleration is similar for light and heavy ions, however, nuances of the acceleration process make the heavy ions more challenging. At least four technical hurdles have been identified: low charge-to-mass ratio, limited number of ions amenable to acceleration, delayed acceleration and poor energy coupling due to high reflectivity of the plasma. Using two dimensional particle-in-cell (PIC) simulations, we observed transitions from Radiation Pressure Acceleration (RPA) to the Breakout Afterburner regime (BoA) and to Target Normal Sheath Acceleration (TNSA) akin to light ions. The numerical simulations predict gold ions beams with high directionality (high fluxes (>1011 ions/sr) and energy (>10 MeV/nucleon) from laser systems delivering >20 J of energy on target.

  16. Enhancing luminescence of Lu{sub 2}MoO{sub 6}:Eu{sup 3+} phosphors by doping with Li{sup +} ions for near ultraviolet based solid state lighting

    Energy Technology Data Exchange (ETDEWEB)

    Li, Li, E-mail: lilic@cqupt.edu.cn [School of Sciences, Chongqing University of Posts and Telecommunications, Chongqing 400065 (China); Shen, Jun; Pan, Yu; Zhou, Xianju; Huang, He; Chang, Wenxuan; He, Qiwei [School of Sciences, Chongqing University of Posts and Telecommunications, Chongqing 400065 (China); Wei, Xiantao [Department of Physics, University of Science and Technology of China, Hefei 230026 (China)

    2016-06-15

    Graphical abstract: The emission spectra of Lu{sub 2}MoO{sub 6}:3%Eu{sup 3+}, x%Li{sup +} phosphors under 365 nm excitation. The inset represents emission intensity of 610 nm as a function of Li{sup +} molar concentration. - Highlights: • Lu{sub 2}MoO{sub 6}:3%Eu{sup 3+}, x%Li{sup +} phosphors were synthesized by solid-state reaction method. • All the prepared phosphors can be assigned to its monoclinic phase. • The optimal concentration of Li{sup +} ions is 30mol%. • The luminescent intensity of Lu{sub 2}MoO{sub 6}:Eu{sup 3+} phosphors has been greatly enhanced by codoping Li{sup +} ions. - Abstract: Lu{sub 2}MoO{sub 6}: 3% Eu{sup 3+} co-doped with x% Li{sup +} (x = 0–40 mol) phosphors were synthesized by high-temperature solid-state reaction method. The structure and luminescent properties of these phosphors were investigated. The X-ray diffraction (XRD) results show that all prepared phosphors can be assigned to monoclinic phase and codoping with Li{sup +} ions does not change their crystallographic structure. The excitation and emission spectra show that the samples can be effectively excited by the near ultraviolet light at 365 nm and exhibit strong red emission centered at 610 nm. The experimental results indicate the red luminescent intensity of Lu{sub 2}MoO{sub 6}:Eu{sup 3+} phosphors has been greatly enhanced by codoping with Li{sup +} ions. The enhancement of the luminescent intensity can be the consequence of the modification of the local field symmetry around the Eu{sup 3+} ion, improved crystallization, and the enlarged grain size induced by the Li{sup +} ions.

  17. Synthesis of Metal Ion-Doped TiO2 Nanoparticles Using Two-Phase Method and Their Photocatalytic Activity Under Visible Light Irradiation.

    Science.gov (United States)

    Nguyen, Duy-Trinh; Hong, Seong-Soo

    2016-02-01

    In this study, TiO2 and metal ion-doped TiO2 nanoparticles were successfully synthesized by solvothermal reaction of titanium butoxide precursor in the presence of oleic acid, oleylamine and vapor water and they were characterized by XRD, Raman, TEM and DRS. We also investigated the photocatalytic activity of these oxides for the decomposition of Rhodamine B. From XRD and Raman results, doping of the metal ion in the crystal lattice did not change the high crystallinity of the TiO2 structure, and all the metal ions were incorporated into the structures of titania as well as replaced titanium ion or located at interstitial site. The absorption band shifted to a higher wavelength on the metal ion-doped TiO2 samples compared to the pure TiO2 sample. The Ce ion- doped TiO2 catalysts showed the higher photocatalytic activity compared to the pure TiO2 and a commercial P-25 catalysts and 1% Ce-doped TiO2 showed the highest photocatalytic activity.

  18. Characterization of SrTiO3 target doped with Co ions, SrCoxTi1-xO3-δ, and their thin films prepared by pulsed laser ablation (PLA) in water for visible light response

    Science.gov (United States)

    Ichihara, Fumihiko; Murata, Yuma; Ono, Hiroshi; Choo, Cheow-keong; Tanaka, Katsumi

    2017-10-01

    SrTiO3 (STO) and Co-doped SrTiO3 (Co-STO) sintered targets were synthesized and were Ar+ sputtered to elucidate the charge compensation effect between Sr, Ti and Co cations following the reduction by oxygen desorption. Following exposure of the Ar+-sputtered target to the air, charge transfer reactions occurred among Co2+, Ti3+, O2- and Sr2+ species which were studied by their XPS spectra. Pulsed laser ablation (PLA) of these targets was carried out in water to prepare the nanoparticles which could be supplied to the thin films with much higher surface reactivity expected for photocatalytic reactions. The roles of Co ions were studied for the stoichiometry and crystallinity of the nanoparticles which constituted the thin films. Photo-degradation of methylene blue was carried out on the PLA thin films under very weak visible light at 460 nm. The PLA thin films showed the photocatalytic activities, which were enhanced by the presence of Co ions. Such the effect of Co ions was considered from viewpoint of the d-d transition and the charge-transfer between Co ions and the ligand oxygen.

  19. Modular cryostat for ion trapping with surface-electrode ion traps

    CERN Document Server

    Vittorini, Grahame; Brown, Kenneth R; Harter, Alexa W; Doret, S Charles

    2013-01-01

    We present a simple cryostat purpose built for use with surface-electrode ion traps, designed around an affordable, large cooling power commercial pulse tube refrigerator. A modular vacuum enclosure with a single vacuum space facilitates interior access, and enables rapid turnaround and flexiblity for future modifications. Long rectangular windows provide nearly 360 degrees of optical access in the plane of the ion trap, while a circular bottom window near the trap enables NA 0.4 light collection without the need for in-vacuum optics. We evaluate the system's mechanical and thermal characteristics, and we quantify ion trapping performance by trapping 40Ca+, finding small stray electric fields, long ion lifetimes, and low ion heating rates.

  20. Modular cryostat for ion trapping with surface-electrode ion traps

    Science.gov (United States)

    Vittorini, Grahame; Wright, Kenneth; Brown, Kenneth R.; Harter, Alexa W.; Doret, S. Charles

    2013-04-01

    We present a simple cryostat purpose built for use with surface-electrode ion traps, designed around an affordable, large cooling power commercial pulse tube refrigerator. A modular vacuum enclosure with a single vacuum space facilitates interior access and enables rapid turnaround and flexibility for future modifications. Long rectangular windows provide nearly 360° of optical access in the plane of the ion trap, while a circular bottom window near the trap enables NA 0.4 light collection without the need for in-vacuum optics. We evaluate the system's mechanical and thermal characteristics and we quantify ion trapping performance by trapping 40Ca+, finding small stray electric fields, long ion lifetimes, and low ion heating rates.

  1. Visible-light-driven Cu(II)-(Sr(1-y)Na(y))(Ti(1-x)Mo(x))O3 photocatalysts based on conduction band control and surface ion modification.

    Science.gov (United States)

    Qiu, Xiaoqing; Miyauchi, Masahiro; Yu, Huogen; Irie, Hiroshi; Hashimoto, Kazuhito

    2010-11-03

    Band-gap narrowing is generally considered to be a primary method in the design of visible-light-active photocatalysts because it can decrease the photo threshold to lower energies. However, controlling the valence band by up-shifting the top of the band or inducing localized levels above the band results in quantum efficiencies under visible light much lower than those under UV irradiation (such as those reported for N-doped TiO(2): Science 2001, 293, 269. J. Phys. Chem. B 2003, 107, 5483). Herein, we report a systematic study on a novel, visible-light-driven photocatalyst based on conduction band control and surface ion modification. Cu(II)-(Sr(1-y)Na(y))(Ti(1-x)Mo(x))O(3) photocatalysts were prepared by a soft chemical method in combination with an impregnation technique. It is found that Mo(6+) as well as Na(+) doping in the SrTiO(3) can lower the bottom of the conduction band and effectively extend the absorption edge to the visible light region. The Cu(II) clusters grafted on the surface act as a co-catalyst to efficiently reduce the oxygen molecules, thus consuming the excited electrons. Consequently, photocatalytic decomposition of gaseous 2-propanol into CO(2) is achieved, that is, CH(3)CHOHCH(3) + (9)/(2)O(2) → 3CO(2) + H(2)O. For Cu(II)-(Sr(1-y)Na(y))(Ti(1-x)Mo(x))O(3) at x = 2.0% under visible light irradiation, the maximum CO(2) generation rate can reach 0.148 μmol/h; the quantum efficiency under visible light is calculated to be 14.5%, while it is 10% under UV light irradiation. Our results suggest that high visible light photocatalytic efficiency can be achieved by combining conduction band control and surface ion modification, which provides a new approach for rational design and development of high-performance photocatalysts.

  2. Negative ions in liquid helium

    Science.gov (United States)

    Khrapak, A. G.; Schmidt, W. F.

    2011-05-01

    The structure of negative ions in liquid 4He is analyzed. The possibility of cluster or bubble formation around impurity ions of both signs is discussed. It is shown that in superfluid helium, bubbles form around negative alkaline earth metal ions and clusters form around halogen ions. The nature of "fast" and "exotic" negative ions is also discussed. It is assumed that "fast" ions are negative ions of helium excimer molecules localized inside bubbles. "Exotic" ions are stable negative impurity ions, which are always present in small amounts in gas discharge plasmas. Bubbles or clusters with radii smaller the radius of electron bubbles develop around these ions.

  3. Structural refinement, band-gap analysis and optical properties of GdAlO3 nanophosphors influenced by Dy3+ ion concentrations for white light emitting device applications

    Science.gov (United States)

    Jisha, P. K.; Naik, Ramachandra; Prashantha, S. C.; Nagaswarupa, H. P.; Nagabhushana, H.; Basavaraj, R. B.; Sharma, S. C.; Prasad, Daruka

    2016-04-01

    Nanosized GdAlO3 phosphors activated with Dy3+ were prepared by a combustion method. Synthesized phosphors were calcined at 1000 °C for 3 h in order to achieve crystallinity. Powder x-ray diffraction (XRD), scanning electron microscope (SEM) and transmission electron microscope (TEM) analysis was used to characterize the prepared product. The orthorhombic phase was observed in the XRD pattern. The particle size of the samples was calculated as around 25 nm. The SEM images show an irregular shape of the prepared nanophosphor. Functional groups of the phosphors were examined by Fourier transform infrared (FTIR) spectroscopy. Photoluminescence (PL) properties of Dy3+ doped GdAlO3 for near-ultraviolet excitation (352 nm) were studied in order to investigate the possibility of its use in white light emitting device applications. Judd-Ofelt intensity parameters, radiative transition rate (A T) and radiative lifetimes (τ rad) were evaluated from the emission spectrum by adopting a standard procedure. The Commission International de l’Eclairage (CIE) color coordinates and correlated color temperature (CCT) are studied for the optimized phosphor. It is found that the color coordinates of Dy3+ doped GdAlO3 powders fall in the white region of the CIE diagram, and the average CCT value was found to be about 6276 K. Therefore, the present phosphor is highly useful for display applications.

  4. Fourier Transform Ion Cyclotron Resonance Mass Spectrometer:Past, Present and Future%傅里叶变换离子回旋共振质谱仪:过去、现在与未来

    Institute of Scientific and Technical Information of China (English)

    李树奇; 鲍晓迪; 殷红; 孔祥蕾

    2015-01-01

    对傅里叶变换离子回旋共振高分辨率质谱仪的发展历程、串联质谱解离技术及最新的应用进行了详细描述,并对其发展趋势进行了展望。%The history and development of Fourier transform ion cyclotron resonance mass spectrometer ( FT ICR MS) is presented in detail. The dissociation technique for tandem mass spectrometry and the latest application are in-troduced. The development trend of FT ICR MS is discussed.

  5. Fast cooling of trapped ions using the dynamical Stark shift

    Energy Technology Data Exchange (ETDEWEB)

    Retzker, A [Institute for Mathematical Sciences, Imperial College London, SW7 2PE (United Kingdom); Plenio, M B [Institute for Mathematical Sciences, Imperial College London, SW7 2PE (United Kingdom)

    2007-08-15

    A laser cooling scheme for trapped ions is presented which is based on the fast dynamical Stark shift gate, described in (Jonathan et al 2000 Phys. Rev. A 62 042307). Since this cooling method does not contain an off resonant carrier transition, low final temperatures are achieved even in a traveling wave light field. The proposed method may operate in either pulsed or continuous mode and is also suitable for ion traps using microwave addressing in strong magnetic field gradients.

  6. ‘... conceived by the Holy Spirit and born of the Virgin Mary’: The exposition of the Heidelberg Catechism in the light of present-day criticism

    Directory of Open Access Journals (Sweden)

    Ignatius W.C. (Natie van Wyk

    2014-02-01

    Full Text Available The article is a contribution to the 450 year celebrations of the Heidelberg Catechism (HC. Sunday 14, Questions and Answers 35 and 36 receive attention. It deals with the two statements of the creed ‘… conceived by the Holy Spirit and born of the Virgin Mary’. The exposition of the HC is compared to the catechisms of Zacharias Ursinus and John Calvin in order to capture something about the historicity of the text. The exposition of the creed is an on-going process. Karl Barth, Eberhard Busch and Jan Milič Lochman are good examples of Reformed theologians who remain faithful to the intention of the HC, but who explain these statements with present-day criticism in mind. The exposition of Peter Berger is valuable because this sceptic argues that the opinion of modern, liberal Protestantism is of no value. The article concludes that the ‘virgin birth’ as such has no great value. It is only one aspect of the Christian gospel. It also does not proof the divinity of Christ. The divinity of Christ is presupposed.

  7. 自激荧光在污染水体中轻重金属离子检测研究%Research of Light and Heavy Metal Ions Detection in Polluted Water Under Self Excited Fluorescence

    Institute of Scientific and Technical Information of China (English)

    周鸿燕

    2014-01-01

    受污染水体中很少存在单一的污染源,导致污染水体中混合污染源难以确定与区分。研究一种在多污染源中各种金属离子的确定和检测问题。提出了采用自激荧光对受污染水体进行检测,对污染物中混有轻重金属的污染水体分别检测,对重金属污染物采用紫外光谱吸收与荧光光谱吸收检测,对轻金属污染物自激荧光光谱检测。形成了活泼金属离子的检测与治理方法,通过分析自激荧光在猝灭过程中产生的特殊光谱特性来进行不同污染物种的金属离子判断,采用紫外光对重金属离子进行二次判断,以达到快速检测的目标。实验结果表明,检测方法能有效检测污染水体中的各金属离子,对受污染水体的判断具有较好的指导性。%The contaminated source single rarely exist in the polluted water, leading to the polluted water in mixed source of pollution is difficult to determine and distinguish. The identification and detection of metal ions in multiple sources are re-searched. The self fluorescence of polluted water body were detected, respectively to detect pollutants mixed with water pol-lution of heavy metals on light, heavy metal pollutants using UV absorption detection and fluorescence spectra of light met-al pollutants, self fluorescence detection. The formation of the active metal ions detection and treatment methods, through the analysis of the special spectral characteristics of self-excited fluorescence in the quenching process for metal ion pollu-tion in different species of judgment, the UV two judgments on heavy metal ions, in order to achieve the goal of rapid detec-tion. The experimental results show that, the metal ion detection method can effectively detect pollution in water bodies, guiding better judgment of polluted water body.

  8. 电雷管脚线成型工艺设备现状与发展趋势%Present Situation and Trends of Process and Equipment of Winding Electric Detonator Lighting Blasting Cap Wire

    Institute of Scientific and Technical Information of China (English)

    杨民刚; 夏光; 杨宗玲

    2014-01-01

    Basing on the production process of winding electric detonator lighting blasting cap wire, the present situation of process and equipment were discussed. With the guidance on the progress of civilian explosives materials technology, the development direction and technical ideas of process technology and equipment for winding electric detonator lighting blasting cap wire were put forward.%在简述电雷管脚线打把生产工艺的基础上,对工艺技术与设备现状进行了分析评述,结合民用爆炸物品技术进步指导意见,提出了工业电雷管脚线制作的工艺技术与设备发展方向和技术思路。

  9. Ion tracking in photocathode rf guns

    Directory of Open Access Journals (Sweden)

    John W. Lewellen

    2002-02-01

    Full Text Available Projected next-generation linac-based light sources, such as PERL or the TESLA free-electron laser, generally assume, as essential components of their injector complexes, long-pulse photocathode rf electron guns. These guns, due to their design rf pulse durations of many milliseconds to continuous wave, may be more susceptible to ion bombardment damage of their cathodes than conventional rf guns, which typically use rf pulses of microsecond duration. This paper explores this possibility in terms of ion propagation within the gun, and presents a basis for future study of the subject.

  10. Multicolor light emitters based on energy exchange between Tb and Eu ions co-doped into ultrasmall β-NaYF 4 nanocrystals

    KAUST Repository

    Podhorodecki, Artur P.

    2012-01-01

    Multicolor emission is reported from ultrasmall (<10 nm) β-NaYF4:Eu,Tb nanocrystals depending on the excitation wavelengths or emission detection delay time. Detailed optical investigations of three samples (NaYF4:Eu, NaYF4:Tb and NaYF4:Eu,Tb) obtained by a co-thermolysis method have been carried out. Photoluminescence, photoluminescence excitation and emission decay time obtained at different excitation wavelengths have been measured. Excitation mechanisms of Eu and Tb ions have been explained based on the experimental results and calculations using Judd-Ofelt theory. It has been shown that efficient energy transfer from Tb to Eu ions accounts for the efficient red emission of NaYF4:Tb,Eu nanocrystals. © The Royal Society of Chemistry 2012.

  11. Factors Affecting the Efficiency of Excited-States Interactions of Complexes between Some Visible Light-Emitting Lanthanide Ions and Cyclophanes Containing Spirobiindanol Phosphonates

    Directory of Open Access Journals (Sweden)

    M. S. Attia

    2007-01-01

    Full Text Available The efficiency of excited-states interactions between lanthanide ions Tb3+ and Eu3+ and some new cyclophanes (I, II, and III has been studied in different media. High luminescence quantum yield values for terbium and europium complexes in DMSO and PMMA were obtained. The photophysical properties of the green and red emissive Tb3+ and Eu3+ complexes have been elucidated, respectively.

  12. Ion trap simulation tools.

    Energy Technology Data Exchange (ETDEWEB)

    Hamlet, Benjamin Roger

    2009-02-01

    Ion traps present a potential architecture for future quantum computers. These computers are of interest due to their increased power over classical computers stemming from the superposition of states and the resulting capability to simultaneously perform many computations. This paper describes a software application used to prepare and visualize simulations of trapping and maneuvering ions in ion traps.

  13. Study on the Orientation of Liquid Crystals Presented on the Glass Substrates Spin-coated and Functionalized with Copper Ions%铜离子功能化的基底表面上液晶取向的研究

    Institute of Scientific and Technical Information of China (English)

    王诗鸣; 熊兴良; 张琰; 李广; 陈萌梦

    2013-01-01

    在液晶型化学与生物传感器的研究中,构建一个能使液晶分子长时间呈稳定、均一的取向排列且制作方法简易的基底表面对于传感器的实用化至关重要.本研究通过将5种不同浓度(0~ 100 mmol/L)的高氯酸铜无水乙醇溶液直接旋转喷涂于载玻片上,制备成具有化学敏感性的铜离子基底表面;随后将5CB液晶滴加在该基底表面,制作成液晶盒(液晶传感器);利用偏光显微镜的直光和锥光模式观察液晶分子的取向排列情况.实验发现在经过较短的时间后,旋涂有高氯酸铜的所有传感器的透射光斑先后逐渐变暗;高氯酸铜的浓度越大,光斑变暗的速度越快,完全变暗所需的时间越短;而未喷涂高氯酸铜的传感器在室温环境(25℃)下静置ld后,其透射光斑亮度没有变化;室温环境下于烘箱中贮存2个月后,喷涂有高氯酸铜的传感器的透射光亮度基本没有变化.结果表明,玻璃表面上直接喷涂高氯酸铜的基底表面能使液晶分子长时间呈稳定、均一的垂直排列;高氯酸铜的浓度对液晶取向排列的响应速度有影响.%A stable,uniform,easily implemented,LC-based chemical and biological sensor substrate for orientations of liquid crystals (LCs) for a long-term is urgently needed for medical applications of the sensors.We proposed a use of spin-coating of copper perchlorate (Cu (ClO4)2),with five different concentrations (0-100mmol/L),directly on glass slides for fabricating a layer of chemically-sensitive copper ions.Observing the transmitted light with a polarized microscope,we found the luminosity of the light propagated through sensors deposited with copper ions started to weaken gradually after a certain time.The higher was the concentration of copper ions covered on the glass substrates of the sensors,the faster the weakening occurred,and the less time was needed for transmitted light to turn completely dark.But there was no change in

  14. Light from Exoplanets: Present and Future

    Science.gov (United States)

    Deming, Leo

    2010-01-01

    Measurements using the Spitzer Space Telescope have revealed thermal emission from planets orbiting very close to solar-type stars, primarily transiting "hot Jupiter" exoplanets. The thermal emission spectrum of these worlds has been measured by exploiting their secondary eclipse. Also, during transit of the planet, absorption signatures from atoms and molecules in the planet's atmosphere are imprinted onto the spectrum of the star. Results to date from transit and eclipse studies show that the hot Jupiters often have significant haze and cloud components in their atmospheres, and the temperature structure can often be inverted, i.e. temperature is rising with height. New and very strongly irradiated examples of hot Jupiters have been found that are being stripped of their atmospheres by tidal forces from the star. In parallel, transiting superEarth exoplanets are being discovered, and their atmospheres should also be amenable to study using transit techniques. The 2014 launch of the James Webb Space Telescope will clarify the physical nature of hot Jupiters, and will extend transit and eclipse studies to superEarths orbiting in the habitable zones of lower main sequence stars.

  15. Radioactive Ion Beams and Radiopharmaceuticals

    Science.gov (United States)

    Laxdal, R. E.; Morton, A. C.; Schaffer, P.

    2014-02-01

    Experiments performed at radioactive ion beam facilities shed new light on nuclear physics and nuclear structure, as well as nuclear astrophysics, materials science and medical science. The many existing facilities, as well as the new generation of facilities being built and those proposed for the future, are a testament to the high interest in this rapidly expanding field. The opportunities inherent in radioactive beam facilities have enabled the search for radioisotopes suitable for medical diagnosis or therapy. In this article, an overview of the production techniques and the current status of RIB facilities and proposals will be presented. In addition, accelerator-generated radiopharmaceuticals will be reviewed.

  16. Merging Visible Light Photoredox Catalysis with Metal Catalyzed C–H Activations: On the Role of Oxygen and Superoxide Ions as Oxidants

    Science.gov (United States)

    2016-01-01

    Conspectus The development of efficient catalytic systems for direct aromatic C–H bond functionalization is a long-desired goal of chemists, because these protocols provide environmental friendly and waste-reducing alternatives to classical methodologies for C–C and C–heteroatom bond formation. A key challenge for these transformations is the reoxidation of the in situ generated metal hydride or low-valent metal complexes of the primary catalytic bond forming cycle. To complete the catalytic cycle and to regenerate the C–H activation catalyst, (super)stoichiometric amounts of Cu(II) or Ag(I) salts have often been applied. Recently, “greener” approaches have been developed by applying molecular oxygen in combination with Cu(II) salts, internal oxidants that are cleaved during the reaction, or solvents or additives enabling the metal hydride reoxidation. All these approaches improved the environmental friendliness but have not overcome the obstacles associated with the overall limited functional group and substrate tolerance. Hence, catalytic processes that do not feature the unfavorable aspects described above and provide products in a streamlined as well as economically and ecologically advantageous manner would be desirable. In this context, we decided to examine visible light photoredox catalysis as a new alternative to conventionally applied regeneration/oxidation procedures. This Account summarizes our recent advances in this expanding area and will highlight the new concept of merging distinct redox catalytic processes for C–H functionalizations through the application of visible light photoredox catalysis. Photoredox catalysis can be considered as catalytic electron-donating or -accepting processes, making use of visible-light absorbing homogeneous and heterogeneous metal-based catalysts, as well as organic dye sensitizers or polymers. As a consequence, photoredox catalysis is, in principle, an ideal tool for the recycling of any given metal

  17. Photoluminescence properties of Tb{sup 3+} and Eu{sup 3+} ions co-doped SrMg{sub 2}La{sub 2}W{sub 2}O{sub 12} phosphors for solid state lighting applications

    Energy Technology Data Exchange (ETDEWEB)

    Pavani, K. [Department of Physics, Sri Venkateswara University, Tirupati 517 502 (India); Suresh Kumar, J., E-mail: jskphysics@yahoo.co.in [Department of Physics and I3N, University of Aveiro, 3810-193 Aveiro (Portugal); Rama Moorthy, L., E-mail: lrmphysics@yahoo.co.in [Department of Physics, Sri Venkateswara University, Tirupati 517 502 (India); Department of Physics, Chadalawada Ramanamma Engineering College, Renigunta Road, Tirupati 517 506 (India)

    2014-02-15

    Highlights: • Tb{sup 3+} and Eu{sup 3+} co-doped SrMg{sub 2}La{sub 2}W{sub 2}O{sub 12} phosphors were prepared by melt quench method. • Structure and photoluminescence properties of prepared phosphors were investigated. • Emission color changed with change of dopants' concentration. • CIE color coordinates and T{sub cct} values were estimated at different excitations. -- Abstract: In this paper, we report a series of Tb{sup 3+} and Eu{sup 3+} activated SrMg{sub 2}La{sub 2}W{sub 2}O{sub 12} phosphors synthesized by the solid state reaction method. The structural and photoluminescence properties have been characterized and analyzed by X-ray diffraction, Fourier transform infrared spectroscopy, photoluminescence and decay measurements. X-ray diffraction pattern confirms that the SrMg{sub 2}La{sub 2}W{sub 2}O{sub 12} powders were well indexed to orthorhombic structure (JCPDS card No. 35-0259). The excitation spectra monitored at 547 and 617 nm consist of a broad band in the region 250–370 nm pertaining to O → W ligand to metal charge transfer transition and several narrow bands related to Tb{sup 3+} and Eu{sup 3+} ions absorptions, respectively. The emission spectra of singly Tb{sup 3+} and Eu{sup 3+} doped SrMg{sub 2}La{sub 2}W{sub 2}O{sub 12} phosphors consist of narrow bands from 4f–4f emission transitions of {sup 5}D{sub 4} and {sup 5}D{sub 0} excited levels to several lower lying levels of Tb{sup 3+} and Eu{sup 3+} ions, respectively. The emission color of phosphors doped with Tb{sup 3+} and Eu{sup 3+} ions has been changed by varying concentrations and excitation wavelengths to obtain white light emission. The Commission Internationale de L’éclairage (CIE) chromaticity coordinates and correlated color temperatures (T{sub cct}) show that the SrMg{sub 2}La{sub 2}W{sub 2}O{sub 12}:TbEu phosphors can be tuned to exhibit white light emission ranging from 450 to 750 nm, when they are excited by ultraviolet (UV) light.

  18. Heavy stable isotope separation by ion cyclotron resonance

    Energy Technology Data Exchange (ETDEWEB)

    Louvet, P.; Compant La Fontaine, A.; Larousse, B.; Patris, M.

    1994-12-31

    The scientific feasibility of the ion cyclotron resonance process (ICR), as well as the technical one, has been investigated carefully for light metallic elements, whose masses lies between 40 and 100/1,2/. The present work deals mainly with the same demonstration for heavier elements such as ytterbium, gadolinium and barium. Recent results, as well as future prospects, are considered here. (authors).

  19. Studies of scintillation light nonproportionality of ZnSe(Te), CsI(Tl) and YAP(Ce) crystals using heavy ions

    CERN Document Server

    Klamra, W; Kapusta, M; Kérek, A; Moszynski, M; Norlin, L O; Novák, D; Possnert, G

    2002-01-01

    The scintillation light yield for ZnSe(Te), CsI(Tl) and YAP(Ce) crystals have been studied with alpha particles, sup 1 sup 2 C and sup 8 sup 1 Br in the energy region 2.8-42.2 MeV. A nonproportional behavior was observed, mostly pronounced for alpha particles on YAP(Ce). The results are understood in terms of delta-rays effect.

  20. Intrinsically stable light source at telecom wavelengths

    CERN Document Server

    Monteiro, Fernando; Sanguinetti, Bruno; Zbinden, Hugo

    2013-01-01

    We present a highly stable light source at telecom wavelengths, based on a short erbium doped fiber. The high stability arises from the high inversion of the Er3+ion population. This source is developed to work as a stable reference in radiometric applications and is useful in any application where high stability and/or a large bandwidth are necessary. The achieved long-term stability is 10 ppm.

  1. A perturbation of DC electric field caused by light ion adhesion to aerosols during the growth in seismic-related atmospheric radioactivity

    Directory of Open Access Journals (Sweden)

    V. M. Sorokin

    2007-01-01

    Full Text Available The influence of variations in conductivity and external electric current variations in the lower atmosphere on DC electric field over a seismic region is investigated. The external current is formed with the occurrence of convective upward transport of charged aerosols and their gravitational sedimentation in the atmosphere. This effect is related with the occurrence of ionization source due to seismic-related emanation of radon and other radioactive elements into the lower atmosphere. An increase in atmosphere radioactivity level results in the appearance of additional sources of ionization, and altitude dependence of the ion formation rate is calculated. Ionization source varies the atmospheric conductivity and the external current through appearance of ions with equilibrium number density and their adhesion to aerosols. We have calculated the perturbation of conductivity and external electric current as a function of altitude. Variation of conductivity and external current in the lower atmosphere leads to a perturbation of electric current which flows in the global atmosphere-ionosphere circuit. Finally, perturbations of DC electric field both on the Earth's surface and in the ionosphere are estimated.

  2. Monomolecular conversion of light alkanes over H-ZSM-5

    NARCIS (Netherlands)

    Narbeshuber, T.; Narbeshuber, Thomas F.; Vinek, Hannelore; Lercher, J.A.

    1995-01-01

    The monomolecular conversion of light n-alkanes (propane to n-hexane) over H-ZSM-5 was investigated between 723 and 823 K. The rates and energies of activation of the individual reactions were determined and a kinetic model for the conversion is presented. The results suggest that carbonium ions are

  3. Mass spectrometry. [in organic ion and biorganic chemistry and medicine

    Science.gov (United States)

    Burlingame, A. L.; Cox, R. E.; Derrick, P. J.

    1974-01-01

    Review of the present status of mass spectrometry in the light of pertinent recent publications spanning the period from December 1971 to January 1974. Following an initial survey of techniques, instruments, and computer applications, a sharp distinction is made between the chemistry of organic (radical-)ions and analytical applications in biorganic chemistry and medicine. The emphasis is on the chemistry of organic (radical-)ions at the expense of inorganic, organometallic, and surface ion chemistry. Biochemistry and medicine are chosen because of their contemporary importance and because of the stupendous contributions of mass spectroscopy to these fields in the past two years. In the review of gas-phase organic ion chemistry, special attention is given to studies making significant contributions to the understanding of ion chemistry.

  4. Heterogeneous photo catalytic degradation of anionic and cationic dyes over TiO(2) and TiO(2) doped with Mo(6+) ions under solar light: Correlation of dye structure and its adsorptive tendency on the degradation rate.

    Science.gov (United States)

    Gomathi Devi, L; Narasimha Murthy, B; Girish Kumar, S

    2009-08-01

    Degradation of synthetic dyes like Methyl Orange (MO), p-amino azo benzene (PAAB), Congo Red (CR), Brilliant Yellow (BY), Rhodamine-B (RB) and Methylene Blue (MB) under solar light were carried out using TiO(2) doped with Mo(6+) ions. The rate constant for the degradation of anionic dyes MO, PAAB, CR and BY was high at pH 5.6, while for cationic dyes the highest rate constant was obtained in the alkaline pH 8.0. These differences can be accounted to their adsorption capacity on the catalyst surface at different pH conditions. Among the photocatalyst used, Mo(6+) (0.06%)-TiO(2) showed enhanced activity due to the effective separation of charge carriers.

  5. Combining the UV-switchability of Keggin ions with a galvanic replacement process to fabricate TiO2-polyoxometalate-bimetal nanocomposites for improved surface enhanced raman scattering and solar light photocatalysis.

    Science.gov (United States)

    Pearson, Andrew; Bhosale, Sheshanath; Bhargava, Suresh K; Bansal, Vipul

    2013-08-14

    While the decoration of TiO2 surfaces with metal nanoparticles has been well-established, the modification of the composition of metal nanoparticles postdeposition onto TiO2 surfaces and applicability of such bimetallic systems for surface enhanced Raman scattering (SERS) and photocatalysis has not hitherto been investigated. In this work, we, for the first time, combine the unique UV-switchability of the Keggin ions of 12-phosphotungstic acid (PTA) to directly form metal nanoparticles (Ag and Cu) onto the colloidal TiO2 surface, with a galvanic replacement process to convert these predeposited metal nanoparticles into bimetallic systems (Ag/Au, Ag/Pt, Cu/Au, Cu/Pt, and Cu/Ag). We further demonstrate the applicability of these novel TiO2-polyoxometalate-bimetal nanocomposites toward improved SERS and solar light photocatalysis.

  6. Quantitative analysis of long chain fatty acids present in a Type I kerogen using electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry: compared with BF₃/MeOH methylation/GC-FID.

    Science.gov (United States)

    Kamga, Albert W; Behar, Fancoise; Hatcher, Patrick G

    2014-05-01

    Long chain fatty acids (LCFAs) are present in various natural samples and are easily detectable using electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry (ESI-FT-ICR-MS) in negative ion mode. The capability of the ESI-FT-ICR-MS for quantifying LCFAs was evaluated by performing a standard addition followed by an internal standard methodology to several kerogen extracts using n-C₂₀ fatty acid as standard. As the concentration of the standard increased, the magnitude of its peak (m/z 311.29525) increased linearly but with two separate slopes, leaving the entire mass spectra relatively unchanged, which shows evidence of reproducibility. Response factors of other LCFAs are obtained using a standard addition approach. We employed five LCFA standards (n-C₁₅, n-C₁₉, n-C₂₄, n-C₂₆, and n-C₃₀) with different carbon numbers. This allowed us to determine the response factor of all fatty acids (with carbon number between 15 and 30) by plotting the slope of each standard versus its carbon number. With the observed response factors and use of the internal standard, the concentrations of LCFAs in four kerogen extracts were measured by ESI-FT-ICR-MS and compared with those from GC-FID. The carbon number distribution obtained by ESI-FT-ICR-MS matched well the GC-FID distribution (5%–50%) with the exception of C₁₆ and C₁₈, considering that ESI-FT-ICR-MS does not differentiate between normal and branched LCFAs, whereas GC-FID does. This allows one to quantitatively compare samples with a relatively similar matrix for specific compounds such as LCFAs with no need of time-consuming derivatization procedures. Moreover, the calibration can be extended to higher carbon numbers with ESI-FT-ICR-MS, beyond the capabilities of GC/MS.

  7. Lighting: Green Light.

    Science.gov (United States)

    Maniccia, Dorine

    2003-01-01

    Explains that by using sustainable (green) building practices, schools and universities can make their lighting systems more efficient, noting that embracing green design principles can help schools attract students. Discusses lighting-control technologies (occupancy sensing technology, daylighting technology, and scheduling based technologies),…

  8. Lighting Design

    DEFF Research Database (Denmark)

    Hansen, Ellen Kathrine; Mullins, Michael

    2014-01-01

    Light as a multi-dimensional design element has fundamental importance for a sustainable environment. The paper discusses the need for an integration of scientific, technical and creative approaches to light and presents theory, methods and applications toward fulfilling this need. A theory...... of design developed from three experiments show how distinct qualitative and quantitative criteria in different disciplinary traditions can be integrated successfully, despite disparate technical/scientific, social scientific and art/humanities backgrounds. The model is applied to a pedagogical curriculum...

  9. Lighting Design

    DEFF Research Database (Denmark)

    Hansen, Ellen Kathrine; Mullins, Michael

    2014-01-01

    of design developed from three experiments show how distinct qualitative and quantitative criteria in different disciplinary traditions can be integrated successfully, despite disparate technical/scientific, social scientific and art/humanities backgrounds. The model is applied to a pedagogical curriculum......Light as a multi-dimensional design element has fundamental importance for a sustainable environment. The paper discusses the need for an integration of scientific, technical and creative approaches to light and presents theory, methods and applications toward fulfilling this need. A theory...

  10. Ion-Ion Neutralization.

    Science.gov (United States)

    1980-12-31

    plasma were identified using a downstream quadrupole mass spectrometer. In these experimento it is a simple matter to establish H+(H 2 0):f as the...pressure as predicted by the Thomson t2rnary mechanism whicK hzr been suownr to be valid experimentally at hiTh rrsurs (,han and Peron, 1:EI4 hereafter t...of NO , NO2 ions in various gases and the ternary recombination coefficients of these ions in the higher pres:;ure ( Thomson ) re"ie. Equation (5) cr>n

  11. Application of Surface Plasmonics for Semiconductor Light-Emitting Diodes

    DEFF Research Database (Denmark)

    Fadil, Ahmed

    This thesis addresses the lack of an efficient semiconductor light source at green emission colours. Considering InGaN based quantum-well (QW) light-emitters and light-emitting diodes (LEDs), various ways of applying surface plasmonics and nano-patterning to improve the efficiency, are investigated....... By placing metallic thin films or nanoparticles (NPs) in the near-field of QW light-emitters, it is possible to improve their internal quantum efficiency (IQE) through the Purcell enhancement effect. It has been a general understanding that in order to achieve surface plasmon (SP) coupling with QWs...... is presented to obtain light extraction efficiency (LEE) improvement through nano-patterning, and IQE improvement through SP-QW coupling. Considering the fabrication process aspect, dry-etching damage on the semiconductor light-emitters from the nano-patterning is also addressed. Different ion-damage treatment...

  12. Layer-by-Layer Self-Assembled Metal-Ion- (Ag-, Co-, Ni-, and Pd- Doped TiO2 Nanoparticles: Synthesis, Characterisation, and Visible Light Degradation of Rhodamine B

    Directory of Open Access Journals (Sweden)

    Mphilisi M. Mahlambi

    2012-01-01

    Full Text Available Metal-ion- (Ag, Co, Ni and Pd doped titania nanocatalysts were successfully deposited on glass slides by layer-by-layer (LbL self-assembly technique using a poly(styrene sulfonate sodium salt (PSS and poly(allylamine hydrochloride (PAH polyelectrolyte system. Solid diffuse reflectance (SDR studies showed a linear increase in absorbance at 416 nm with increase in the number of m-TiO2 thin films. The LbL assembled thin films were tested for their photocatalytic activity through the degradation of Rhodamine B under visible-light illumination. From the scanning electron microscope (SEM, the thin films had a porous morphology and the atomic force microscope (AFM studies showed “rough” surfaces. The porous and rough surface morphology resulted in high surface areas hence the high photocatalytic degradation (up to 97% over a 6.5 h irradiation period using visible-light observed. Increasing the number of multilayers deposited on the glass slides resulted in increased film thickness and an increased rate of photodegradation due to increase in the availability of more nanocatalysts (more sites for photodegradation. The LbL assembled thin films had strong adhesion properties which made them highly stable thus displaying the same efficiencies after five (5 reusability cycles.

  13. Cold Strontium Ion Source for Ion Interferometry

    Science.gov (United States)

    Jackson, Jarom; Durfee, Dallin

    2015-05-01

    We are working on a cold source of Sr Ions to be used in an ion interferometer. The beam will be generated from a magneto-optical trap (MOT) of Sr atoms by optically ionizing atoms leaking out a carefully prepared hole in the MOT. A single laser cooling on the resonant transition (461 nm) in Sr should be sufficient for trapping, as we've calculated that losses to the atom beam will outweigh losses to dark states. Another laser (405 nm), together with light from the trapping laser, will drive a two photon transition in the atom beam to an autoionizing state. Supported by NSF Award No. 1205736.

  14. Influence of metal ion on the chromatic light of reactive dyes%金属离子对活性染料色光的影响

    Institute of Scientific and Technical Information of China (English)

    展义臻; 赵雪; 王炜

    2015-01-01

    Effects of Ca2+、Cu2+、Fe2+ on the chromatic light 13 different reactive dyes were investigated. The results show that Cu2+ offers great influence on the dyeing chromatic light of black reactive dyes, bright red, dark red, Navy, brilliant yellow and Yellow EX-D4R, but it shows little influence on that of Brilliant Blue R, Turquoise Blue G, and Yellow 3RS. Fe3+ has a litter influence on reactive dyes except for Bright Red GG, Brilliant Yellow 3G and Turquoise Blue G. Ca2+ has a little influence on reactive dyes.%探讨了Ca2+、Cu2+、Fe3+3种金属离子对常用的13只活性染料色光的影响,结果表明:Cu2+对黑色活性染料、黄色调的大红和蓝色调的深红、藏青、嫩黄和活性EX-D4R黄等影响较大,而对活性R艳蓝、活性G翠蓝、活性3RS黄等影响相对较小。除了艳色调的活性GG大红、活性3G嫩黄和活性G翠蓝,Fe3+对活性染料影响相对较小。Ca2+对活性染料总体影响较小。

  15. Synthesis and luminescence properties of Eu{sup 3+}/Dy{sup 3+} ions co-doped Ca{sub 2}La{sub 8}(GeO{sub 4}){sub 6}O{sub 2} phosphors for white-light applications

    Energy Technology Data Exchange (ETDEWEB)

    Jeon, Yong Il; Krishna Bharat, L.; Yu, Jea Su, E-mail: jsyu@khu.ac.kr

    2015-01-25

    Highlights: • CLGO phosphors were successfully prepared by a pechini sol–gel process. • Eu{sup 3+} and Dy{sup 3+} ions single-doped CLGO phosphors provide red and cool white-light emissions. • Eu{sup 3+}/Dy{sup 3+} ions co-doping gives warm white light with increasing the Eu{sup 3+} ion concentration. • This single-phase white light is achieved by 361 nm (UV/NUV LEDs) excitation. - Abstract: Eu{sup 3+}/Dy{sup 3+} ions co-doped Ca{sub 2}La{sub 8}(GeO{sub 4}){sub 6}O{sub 2} (CLGO) phosphors were prepared by a pechini-type sol–gel method. The structural and morphological studies of the CLGO phosphors were carried out by measuring X-ray diffraction patterns and scanning electron microscope images. The photoluminescence (PL) spectra of the CLGO:Eu{sup 3+} phosphor exhibited the intense red emission due to the electric-dipole transition while the CLGO:Dy{sup 3+} phosphor showed the blue ({sup 4}F{sub 9/2} → {sup 6}H{sub 15/2}) and yellow ({sup 4}F{sub 9/2} → {sup 6}H{sub 13/2}) emissions with almost equal intensities. The Eu{sup 3+}/Dy{sup 3+} ions co-doped CLGO phosphor showed the improved white light by shifting towards the warm white region. The energy transfer from Dy{sup 3+} to Eu{sup 3+} ions was investigated by means of PL intensities. The lifetime measurements were also performed for single-doped and co-doped samples. The calculated chromaticity coordinates indicated that these phosphors may be suitable for the fabrication of near-UV excitation-based white light-emitting diodes.

  16. 共振光散射比浊法测定胶片废水中银离子的研究%Research on Determination of Argentum ions in the Waste Water of Film by Resonance Light Scattering Turbidimetric Method

    Institute of Scientific and Technical Information of China (English)

    刘勇; 潘可亮; 王川; 李树伟; 申金山

    2012-01-01

    氯化银胶体在375、496和565 nm产生3个明显的共振散射峰,其中496 nm处的散射峰强度最大且最稳定,适于进行共振光散射比浊法分析.探讨了共振光散射比浊法的机理,建立了在酸性氯化钠-乙二醇溶液中,共振光散射比浊法测定银离子的新方法.线性回归方程IRLS=7.60cAg+4-4.82,R=0.999 8:检出限0.04μg/mL.此方法用于实际样品测定,取得了满意效果.%Colloidal Argentum Chloride at 375,496,565 run has three significant resonance scattering peak in which the scattering peak intensity at 496 run is largest and most stable, and is suitable for the resonance light scattering turbidimetry method. In this paper , we discuss the mechanism of the resonance light scattering turbidimetry, and establish a new method for determination of Argentum ions in acidic sodium chloride-ethylere glycol solution using the resonance light scattering turbidimetry. In this linear regression equation, IRLS =7.60CAg- -4. 82, and R is 0.999 8, and detection limit is 0.04 μg/mL. This method is suitable when applied in real samples.

  17. Heavy ion storage rings

    Energy Technology Data Exchange (ETDEWEB)

    Schuch, R.

    1987-01-01

    A brief overview of synchrotron storage rings for heavy ions, which are presently under construction in different accelerator laboratories is given. Ions ranging from protons up to uranium ions at MeV/nucleon energies will be injected into these rings using multiturn injection from the accelerators available or being built in these laboratories. After injection, it is planned to cool the phase space distribution of the ions by merging them with cold electron beams or laser beams, or by using stochastic cooling. Some atomic physics experiments planned for these rings are presented.

  18. Ion-selective electrode reviews

    CERN Document Server

    Thomas, J D R

    1983-01-01

    Ion-Selective Electrode Reviews, Volume 5 is a collection of articles that covers ion-speciation. The book aims to present the advancements of the range and capabilities of selective ion-sensors. The topics covered in the selection are neutral carrier based ion-selective electrodes; reference electrodes and liquid junction effects in ion-selective electrode potentiometry; ion transfer across water/organic phase boundaries and analytical; and carbon substrate ion-selective electrodes. The text will be of great use to chemists and chemical engineers.

  19. Ce3+-ion-induced visible-light photocatalytic degradation and electrochemical activity of ZnO/CeO2 nanocomposite

    Science.gov (United States)

    Rajendran, Saravanan; Khan, Mohammad Mansoob; Gracia, F.; Qin, Jiaqian; Gupta, Vinod Kumar; Arumainathan, Stephen

    2016-08-01

    In this study, pure ZnO, CeO2 and ZnO/CeO2 nanocomposites were synthesized using a thermal decomposition method and subsequently characterized using different standard techniques. High-resolution X-ray photoelectron spectroscopy measurements confirmed the oxidation states and presence of Zn2+, Ce4+, Ce3+ and different bonded oxygen species in the nanocomposites. The prepared pure ZnO and CeO2 as well as the ZnO/CeO2 nanocomposites with various proportions of ZnO and CeO2 were tested for photocatalytic degradation of methyl orange, methylene blue and phenol under visible-light irradiation. The optimized and highly efficient ZnO/CeO2 (90:10) nanocomposite exhibited enhanced photocatalytic degradation performance for the degradation of methyl orange, methylene blue, and phenol as well as industrial textile effluent compared to ZnO, CeO2 and the other investigated nanocomposites. Moreover, the recycling results demonstrate that the ZnO/CeO2 (90:10) nanocomposite exhibited good stability and long-term durability. Furthermore, the prepared ZnO/CeO2 nanocomposites were used for the electrochemical detection of uric acid and ascorbic acid. The ZnO/CeO2 (90:10) nanocomposite also demonstrated the best detection, sensitivity and performance among the investigated materials in this application. These findings suggest that the synthesized ZnO/CeO2 (90:10) nanocomposite could be effectively used in various applications.

  20. Ce(3+)-ion-induced visible-light photocatalytic degradation and electrochemical activity of ZnO/CeO2 nanocomposite.

    Science.gov (United States)

    Rajendran, Saravanan; Khan, Mohammad Mansoob; Gracia, F; Qin, Jiaqian; Gupta, Vinod Kumar; Arumainathan, Stephen

    2016-08-16

    In this study, pure ZnO, CeO2 and ZnO/CeO2 nanocomposites were synthesized using a thermal decomposition method and subsequently characterized using different standard techniques. High-resolution X-ray photoelectron spectroscopy measurements confirmed the oxidation states and presence of Zn(2+), Ce(4+), Ce(3+) and different bonded oxygen species in the nanocomposites. The prepared pure ZnO and CeO2 as well as the ZnO/CeO2 nanocomposites with various proportions of ZnO and CeO2 were tested for photocatalytic degradation of methyl orange, methylene blue and phenol under visible-light irradiation. The optimized and highly efficient ZnO/CeO2 (90:10) nanocomposite exhibited enhanced photocatalytic degradation performance for the degradation of methyl orange, methylene blue, and phenol as well as industrial textile effluent compared to ZnO, CeO2 and the other investigated nanocomposites. Moreover, the recycling results demonstrate that the ZnO/CeO2 (90:10) nanocomposite exhibited good stability and long-term durability. Furthermore, the prepared ZnO/CeO2 nanocomposites were used for the electrochemical detection of uric acid and ascorbic acid. The ZnO/CeO2 (90:10) nanocomposite also demonstrated the best detection, sensitivity and performance among the investigated materials in this application. These findings suggest that the synthesized ZnO/CeO2 (90:10) nanocomposite could be effectively used in various applications.

  1. Nonlinear dust-ion-acoustic waves in a multi-ion plasma with trapped electrons

    Indian Academy of Sciences (India)

    S S Duha; B Shikha; A A Mamun

    2011-08-01

    A dusty multi-ion plasma system consisting of non-isothermal (trapped) electrons, Maxwellian (isothermal) light positive ions, warm heavy negative ions and extremely massive charge fluctuating stationary dust have been considered. The dust-ion-acoustic solitary and shock waves associated with negative ion dynamics, Maxwellian (isothermal) positive ions, trapped electrons and charge fluctuating stationary dust have been investigated by employing the reductive perturbation method. The basic features of such dust-ion-acoustic solitary and shock waves have been identified. The implications of our findings in space and laboratory dusty multi-ion plasmas are discussed.

  2. Comparison of optical localization techniques for optical coherence tomography of the hand for multi-fraction orthovoltage radiotherapy or photodynamic therapy: white light vs. optical surface imaging (Conference Presentation)

    Science.gov (United States)

    Jakubovic, Raphael; Bains, Amitpal; Ramjist, Joel; Babic, Steve; Chin, Lee; Barnes, Elizabeth; Yang, Victor X. D.

    2017-02-01

    Non-melanoma skin cancer (NMSC) is considered the most commonly diagnosed cancer in the United States and Canada. Treatment options include radiotherapy, surgical excision, radiotherapy, topical therapies, electrocautery, and cryotherapy. For patients undergoing fractionated orthovoltage radiation therapy or photodynamic therapy (PDT), the lesions are typically delineated by clinical markup prior to treatment without providing any information about the underlying tissue thus increasing the risk of geographic miss. The development of biomarkers for response in NMSC is imperative considering the current treatment paradigm is based on clinical examination and biopsy confirmation. Therefore, a non-invasive image-based evaluation of skin structure would allow for faster and potentially more comprehensive microscopic evaluation of the treated region at the point of care. To address this, our group is investigating the use of optical coherence tomography (OCT) for pre- and post- treatment evaluation of NMSC lesions during radiation therapy and PDT. Localization of the OCT probe for follow-up is complex, especially in the context of treatment response where the lesion is not present, precluding accurate delineation of the planning treatment area. Further, comparison to standard white light pre-treatment images is limited by the scale of the OCT probe (6 mm X 6 mm) relative to target region. In this study we compare the set-up accuracy of a typical OCT probe to detect a theoretical lesion on a patient's hand. White light images, optical surface imaging (OSI) and OCT will be obtained at baseline and used for probe set up on subsequent scans. Set-up error will be quantified using advanced image processing techniques.

  3. The site occupation and valence of Mn ions in the crystal lattice of Sr{sub 4}Al{sub 14}O{sub 25} and its deep red emission for high color-rendering white light-emitting diodes

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Lei, E-mail: shanggan2009@qq.com [School of Materials Science and Engineering, Hefei University of Technology, Hefei 230009 (China); Xue, Shaochan; Chen, Xiuling [School of Materials Science and Engineering, Hefei University of Technology, Hefei 230009 (China); Bahader, Ali [Department of Chemistry, Hazara University, Mansehra 21300 (Pakistan); Deng, Xiaorong; Zhao, Erlong; Jiang, Yang [School of Materials Science and Engineering, Hefei University of Technology, Hefei 230009 (China); Chen, Shifu, E-mail: chshifu@chnu.edu.cn [Department of Chemistry, Huaibei Normal University, Huaibei 235000 (China); Chan, Ting-Shan [National Synchrotron Radiation Research Center, Hsinchu 30076, Taiwan, ROC (China); Zhao, Zhi; Zhang, Wenhua [National Synchrotron Radiation Laboratory, University of Science and Technology, Hefei, Anhui 230026 (China)

    2014-12-15

    Highlights: • Different valences of Mn ions in Sr{sub 4}Al{sub 14}O{sub 25} were identified using XANES and EPR. • Red luminescence was attributed to Mn{sup 4+} occupying the center of AlO{sub 6} octahedron. • The Mn{sup 3+} incorporated in the center of AlO{sub 4} tetrahedron was non-luminescent. • The bond-valence theory was used to analyze the effective valences of cations. • A white LED device with CRI up to Ra 93.23 was packaged by using the red phosphor. - Abstract: The synthesis and component of red phosphor, Sr{sub 4}Al{sub 14}O{sub 25}: Mn, were optimized for application in white light-emitting diodes. The microstructure and morphology were investigated by the X-ray diffraction and scanning electron microscopy. Different valences of Mn ions in Sr{sub 4}Al{sub 14}O{sub 25} were discriminated using the electron paramagnetic resonance and X-ray absorption near-edge structure spectroscopy techniques. The bond-valence theory was used to analyze the effective valences of Sr{sup 2+} and Al{sup 3+} in Sr{sub 4}Al{sub 14}O{sub 25}. As a result, the strong covalence of Al{sup 3+} in the AlO{sub 4} tetrahedron other than in the AlO{sub 6} octahedron is disclosed. The deep red emission is attributed to Mn{sup 4+} occupying the center of AlO{sub 6} octahedron. The mechanism of energy transfer is mainly through dipole–dipole interaction, revealed by the analyses of critical distance and concentration quench. A high color rendering white LED prototype with color-rendering index up to Ra 93.23 packaged by using the red phosphor demonstrates its applicability.

  4. Poly(ionic liquid)/Ionic Liquid Ion-Gels with High "Free" Ionic Liquid Content: Platform Membrane Materials for CO2/Light Gas Separations.

    Science.gov (United States)

    Cowan, Matthew G; Gin, Douglas L; Noble, Richard D

    2016-04-19

    -films (ca. 100-nm-thick active layer). Traditional polymeric membrane materials are limited by a trade-off between permeability and selectivity empirically described by the "Robeson upper bound"-placing the desired membrane properties beyond reach. Therefore, the investigation of advanced and composite materials that can overcome the limitations of traditional polymeric materials is the focus of significant academic and industrial research. In particular, there has been substantial work on ionic-liquid (IL)-based materials due to their gas transport properties. This review provides an overview of our collaborative work on developing poly(ionic liquid)/ionic liquid (PIL/IL) ion-gel membrane technology. We detail developmental work on the preparation of PIL/IL composites and describe how this chemical technology was adapted to allow the roll-to-roll processing and preparation of membranes with defect-free active layers ca. 100 nm thick, CO2 permeances of over 6000 GPU, and CO2/N2 selectivity of ≥20-properties with the potential to reduce the cost of CO2 removal from coal-fired power plant flue gas to ca. $15 per ton of CO2 captured. Additionally, we examine the materials developments that have produced advanced PIL/IL composite membranes. These advancements include cross-linked PIL/IL blends, step-growth PIL/IL networks with facilitated transport groups, and PIL/IL composites with microporous additives for CO2/CH4 separations.

  5. Present time

    CERN Document Server

    Romero, Gustavo E

    2014-01-01

    The idea of a moving present or `now' seems to form part of our most basic beliefs about reality. Such a present, however, is not reflected in any of our theories of the physical world. I show in this article that presentism, the doctrine that only what is present exists, is in conflict with modern relativistic cosmology and recent advances in neurosciences. I argue for a tenseless view of time, where what we call `the present' is just an emergent secondary quality arising from the interaction of perceiving self-conscious individuals with their environment. I maintain that there is no flow of time, but just an ordered system of events.

  6. Tunable luminescence and white light emission of novel multiphase sodium calcium silicate nanophosphors doped with Ce{sup 3+}, Tb{sup 3+}, and Mn{sup 2+} ions

    Energy Technology Data Exchange (ETDEWEB)

    Mickens, Matthew A. [Energy and Environmental Systems, North Carolina A and T State University, Greensboro, NC 27411 (United States); Assefa, Zerihun, E-mail: zassefa@ncat.edu [Department of Chemistry, North Carolina A and T State University, Greensboro, NC 27411 (United States)

    2014-01-15

    This study reports the sol–gel synthesis of sodium calcium multiphase silicate (SCMS) nanophosphors. X-ray powder diffraction indicated the crystallization of devitrite (Na{sub 2}Ca{sub 3}Si{sub 6}O{sub 16}), wollastonite-2M (CaSiO{sub 3}), and cristobalite (SiO{sub 2}) phases that consistently occurred together upon repeated syntheses. The multiphase silicate system was used as a host matrix for varied concentrations of Ce{sup 3+}, Tb{sup 3+}, and Mn{sup 2+} dopant ions which resulted in tunable photoluminescence. A broad violet/UV emission band of Ce{sup 3+} (350–425 nm) combined with blue-green emissions of Tb{sup 3+} (488 and 545 nm) and a yellow-orange emission of Mn{sup 2+} (560 nm) resulted in the observance of white light (x=0.31, y=0.32, T{sub C}=6624 K) under midwave UV excitation (300–340 nm). Energy transfer from Ce{sup 3+}→Tb{sup 3+} and Ce{sup 3+}→Mn{sup 2+} was confirmed by steady state and time-resolved emission spectra, lifetime, and quantum yield measurements. The structural properties, morphology, and elemental composition of the nanophosphors were characterized by Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), and energy dispersive spectroscopy (EDS). -- Highlights: • White light-emitting multiphase silicate nanophosphors were prepared for the first time. • Multiple crystalline silicate phases were reproduced consistently by repeated syntheses. • Energy transfer from Ce{sup 3+}→Tb{sup 3+} and Ce{sup 3+}→Mn{sup 2+} was confirmed by PL, lifetime, and QY measurements.

  7. Lithium-ion batteries

    CERN Document Server

    Yoshio, Masaki; Kozawa, Akiya

    2010-01-01

    This book is a compilation of up-to-date information relative to Li-Ion technology. It provides the reader with a single source covering all important aspects of Li-Ion battery operations. It fills the gap between the old original Li-Ion technology and present state of the technology that has developed into a high state of practice. The book is designed to provide a single source for an up-to-date description of the technology associated with the Li-Ion battery industry. It will be useful to researchers interested in energy conversion for the direct conversion of chemical energy into electrica

  8. Microchip and wedge ion funnels and planar ion beam analyzers using same

    Science.gov (United States)

    Shvartsburg, Alexandre A; Anderson, Gordon A; Smith, Richard D

    2012-10-30

    Electrodynamic ion funnels confine, guide, or focus ions in gases using the Dehmelt potential of oscillatory electric field. New funnel designs operating at or close to atmospheric gas pressure are described. Effective ion focusing at such pressures is enabled by fields of extreme amplitude and frequency, allowed in microscopic gaps that have much higher electrical breakdown thresholds in any gas than the macroscopic gaps of present funnels. The new microscopic-gap funnels are useful for interfacing atmospheric-pressure ionization sources to mass spectrometry (MS) and ion mobility separation (IMS) stages including differential IMS or FAIMS, as well as IMS and MS stages in various configurations. In particular, "wedge" funnels comprising two planar surfaces positioned at an angle and wedge funnel traps derived therefrom can compress ion beams in one dimension, producing narrow belt-shaped beams and laterally elongated cuboid packets. This beam profile reduces the ion density and thus space-charge effects, mitigating the adverse impact thereof on the resolving power, measurement accuracy, and dynamic range of MS and IMS analyzers, while a greater overlap with coplanar light or particle beams can benefit spectroscopic methods.

  9. Effect of Ion Escape Velocity and Conversion Surface Material on H- Production

    Energy Technology Data Exchange (ETDEWEB)

    Tarvainen, Olli [University of Jyvaskyla; Kalvas, T. [University of Jyvaskyla; Komppula, J. [University of Jyvaskyla; Koivisto, H. [University of Jyvaskyla; Geros, E. [Los Alamos National Laboratory (LANL); Stelzer, J. [Los Alamos National Laboratory (LANL); Rouleau, G. [Los Alamos National Laboratory (LANL); Johnson, K.F. [Los Alamos National Laboratory (LANL); Carmichael, Justin R [ORNL

    2011-01-01

    According to generally accepted models surface production of negative ions depends on ion escape velocity and work function of the surface. We have conducted an experimental study addressing the role of the ion escape velocity on H- production. A converter-type ion source at Los Alamos Neutron Science Center was employed for the experiment. The ion escape velocity was affected by varying the bias voltage of the converter electrode. It was observed that due to enhanced stripping of H- no direct gain of extracted beam current can be achieved by increasing the converter voltage. The conversion efficiency of H- was observed to vary with converter voltage and follow the existing theories in qualitative manner. We present calculations predicting relative H- yields from different cesiated surfaces with comparison to experimental observations from different types of H- ion sources. Utilizing materials exhibiting negative electron affinity and exposed to UV-light is considered for Cesium-free H-/D- production.

  10. The design of lighting

    CERN Document Server

    Tregenza, Peter

    2013-01-01

    This fully updated edition of the successful book The Design of Lighting, provides the lighting knowledge needed by the architect in practice, the interior designer and students of both disciplines. The new edition offers a clear structure, carefully selected material and linking of lighting with other subjects, in order to provide the reader with a comprehensive and specifically architectural approach to lighting. Features of this new edition include:technical knowledge of lighting in the context of architectural design;an emphasis on imagination in architectural light and presentation of the

  11. Fast cooling of trapped ions using the dynamical Stark shift gate

    OpenAIRE

    Retzker, A.; Plenio, M. B.

    2006-01-01

    A laser cooling scheme for trapped ions is presented which is based on the fast dynamical Stark shift gate, described in [Jonathan etal, PRA 62, 042307]. Since this cooling method does not contain an off resonant carrier transition, low final temperatures are achieved even in traveling wave light field. The proposed method may operate in either pulsed or continuous mode and is also suitable for ion traps using microwave addressing in strong magnetic field gradients.

  12. Effects of source temperature and characteristics on the optical emission from a gallium liquid metal ion source

    Energy Technology Data Exchange (ETDEWEB)

    Hornsey, R.I.; Marriott, P.

    1989-05-14

    The light emitted from the region close to the tip of an emitting liquid metal ion source has been observed. It is shown that at high currents the light intensity rises almost as the cube of the current, but that the optical emission also depends on the source characteristics. A model based on the break-up of charged droplets is proposed to account for these results, thermal evaporation being found to be insignificant. Measurements of the effects of source temperature on light emission are also presented. From these measurements it is demonstrated that field ionisation cannot be responsible for the distortion of the total ion energy distribution seen at elevated temperatures. (author).

  13. Recent results from the ATLAS heavy ion program

    CERN Document Server

    Slovak, Radim; The ATLAS collaboration

    2017-01-01

    The heavy ion program in the ATLAS experiment at the Large Hadron Collider aims to probe and characterize the hot, dense matter created in relativistic lead-lead collisions, in the context of smaller collision systems involving nuclei and hadrons. This talk presents recent results based on LHC Run 1 and Run 2 data, including measurements of bulk collectivity, electroweak bosons, jet modifications, and quarkonium suppression. Results will also be presented on electromagnetic processes in ultra-peripheral collisions, including forward dilepton production and light-by-light scattering.

  14. CATCHY PRESENTATIONS

    DEFF Research Database (Denmark)

    Eriksen, Kaare; Tollestrup, Christian; Ovesen, Nis

    2011-01-01

    An important competence for designers is the ability to communicate and present ideas and proposals for customers, partners, investors and colleagues. The Pecha Kucha principle, developed by Astrid Klein and Mark Dytham, has become a widely used and easy format for the presentation of new concepts...

  15. Luminescent ion pairs with tunable emission colors for light-emitting devices and electrochromic switches† †Electronic supplementary information (ESI) available: Details of NMR and MS spectra. See DOI: 10.1039/c6sc02837c Click here for additional data file.

    Science.gov (United States)

    Guo, Song; Huang, Tianci; Liu, Shujuan; Zhang, Kenneth Yin; Yang, Huiran; Han, Jianmei

    2017-01-01

    Most recently, stimuli-responsive luminescent materials have attracted increasing interest because they can exhibit tunable emissive properties which are sensitive to external physical stimuli, such as light, temperature, force, and electric field. Among these stimuli, electric field is an important external stimulus. However, examples of electrochromic luminescent materials that exhibit emission color change induced by an electric field are limited. Herein, we have proposed a new strategy to develop electrochromic luminescent materials based on luminescent ion pairs. Six tunable emissive ion pairs (IP1–IP6) based on iridium(iii) complexes have been designed and synthesized. The emission spectra of ion pairs (IPs) show concentration dependence and the energy transfer process is very efficient between positive and negative ions. Interestingly, IP6 displayed white emission at a certain concentration in solution or solid state. Thus, in this contribution, UV-chip (365 nm) excited light-emitting diodes showing orange, light yellow and white emission colors were successfully fabricated. Furthermore, IPs displayed tunable and reversible electrochromic luminescence. For example, upon applying a voltage of 3 V onto the electrodes, the emission color of the solution of IP1 near the anode or cathode changed from yellow to red or green, respectively. Color tunable electrochromic luminescence has also been realized by using other IPs. Finally, a solid-film electrochromic switch device with a sandwiched structure using IP1 has been fabricated successfully, which exhibited fast and reversible emission color change. PMID:28451179

  16. A Multicusp Ion Source for Radioactive Ion Beams

    Science.gov (United States)

    Wutte, D.; Freedman, S.; Gough, R.; Lee, Y.; Leitner, M.; Leung, K. N.; Lyneis, C.; Picard, D. S.; Sun, L.; Williams, M. D.; Xie, Z. Q.

    1997-05-01

    In order to produce a radioactive ion beam of (14)O+, a 10-cm-diameter, 13.56 MHz radio frequency (rf) driven multicusp ion source is now being developed at Lawrence Berkeley National Laboratory. In this paper we describe the specific ion source design and the basic ion source characteristics using Ar, Xe and a 90types of measurements have been performed: extractable ion current, ion species distributions, gas efficiency, axial energy spread and ion beam emittance measurements. The source can generate ion current densities of approximately 60 mA/cm2 . In addition the design of the ion beam extraction/transport system for the actual experimental setup for the radioactive beam line will be presented.

  17. Cassini observations of ion cyclotron waves and ions anisotropy

    Science.gov (United States)

    Crary, F. J.; Dols, V. J.; Cassidy, T. A.; Tokar, R. L.

    2013-12-01

    In Saturn's equatorial, inner magnetosphere, the production of fresh ions in a pick-up distribution generates ion cyclotron waves. These waves are a sensitive indicator of fresh plasma production, but the quantitative relation between wave properties and ionization rates is nontrivial. We present a combined analysis of Cassini MAG and CAPS data, from a variety of equatorial orbits between 2005 and 2012. Using the MAG data, we determine the amplitude and peak frequency of ion cyclotron waves. From the CAPS data we extract the parallel and perpendicular velocity distribution of water group ions. We compare these results with hybrid simulations of the ion cyclotron instability and relate the observed wave amplitudes and ion velocity distributions to the production rate of pickup ions. The resulting relation between wave and plasma properties will allow us to infer ion production rates even at times when no direct ion measurements are available.

  18. Enhancing the light-matter interaction using slow light: towards the concept of dense light

    OpenAIRE

    Thévenaz, Luc; Dicaire, Isabelle; Chin, Sang Hoon

    2012-01-01

    A couple of experiments are here presented to clarify the impact of slow light on light-matter interaction. The experiments are designed, so that the process generating slow light and the probed light-matter interaction only present a marginal cross-effect. The impact of slow light on simple molecular absorption could be separately evaluated under either material or structural slow light propagation in the same medium and led to an entirely different response.

  19. Development of a superconducting CH-accelerator-structure for light and heavy ions; Entwicklung einer supraleitenden CH-Beschleuniger-Struktur fuer leichte und schwere Ionen

    Energy Technology Data Exchange (ETDEWEB)

    Liebermann, Holger

    2007-07-01

    This work deals with the development of the prototype of a superconducting CH accelerator structure. The simulations were calculated with the program CST Microwave Studio. It is based on the finite integration theory, which the Maxwell equations in a two-grid matrix form convicted so they can be solved numerically. In another chapter, a method for determining the coupling strength is discussed. The conditions that previously were created for the optimization of the prototype of the superconducting CH structure are described. It was for the optimization of the field distribution on the beam axis by adjusting the end cell design, optimization of support for the magnetic and electric fields, leading to reduction of the quadrupole component of the CH-structure, the coupling and, finally, the possibility of static tuning during the completion of the structure. On the basis of these investigations the completion of an initial prototype superconducting at the company ACCEL in Bergisch Gladbach was commissioned. Finally simulations for an operation accelerator facility, and a look at possible areas of the superconducting CH-structure are presented. The optimizations performed for the high power injector led to a more stable operation of the plant. Through this work it could be shown that the newly-CH structure is very well suited for use in superconducting accelerators. (orig.)

  20. EDITORIAL: Controlling light with light

    Science.gov (United States)

    Hesselink, Lambertus; Feinberg, Jack; Roosen, Gerald

    2008-11-01

    The field of photorefractive physics and optics is mature and, although there is no significant commercial activity using photorefractive media, researchers in the field have had an extraordinary impact on many related areas of research and development. For example, in the late 1990s many of the telecom innovations and products were based on the interaction between light and matter. Examples include optical switches, filters, gratings, routers and light sources. The theory of multiple interacting beams of light inside a photosensitive medium, many of which were developed or further explored in photorefractive media, has found application in medicine, engineering, communication systems, displays and other photonics devices. On the occasions of the 30th anniversary of the theory of coupled wave analysis and the 10th anniversary of the meetings on Photorefractive Effects and Devices, it seemed appropriate to the meeting organizers of PR'07 to broaden the scope to include other related fields. The name of the meeting was changed to Controlling Light with Light: Photorefractive Effects, Photosensitivity, Fiber Gratings, Photonic Materials and More to attract a larger audience than traditionally would attend the more narrowly focused photorefractive meeting. To further disseminate the results of the 2007 meeting, Gerald Roosen proposed a special publication of original full research articles arising from key presentations at the meeting. The selection of papers in this Cluster Issue of Journal of Physics D: Applied Physics is the result of that initiative. We would like to thank all the authors for their contributions, the committee members for their valuable insight and efforts in helping to organize the meeting, and the Optical Society of America for their professional assistance throughout the preparation period of the meeting as well as during the three beautiful days in Lake Tahoe, CA.

  1. Information Presentation

    Science.gov (United States)

    Holden, Kritina L.; Thompson, Shelby G.; Sandor, Aniko; McCann, Robert S.; Kaiser, Mary K.; Adelstein, Barnard D.; Begault, Durand R.; Beutter, Brent R.; Stone, Leland S.; Godfroy, Martine

    2009-01-01

    The goal of the Information Presentation Directed Research Project (DRP) is to address design questions related to the presentation of information to the crew. In addition to addressing display design issues associated with information formatting, style, layout, and interaction, the Information Presentation DRP is also working toward understanding the effects of extreme environments encountered in space travel on information processing. Work is also in progress to refine human factors-based design tools, such as human performance modeling, that will supplement traditional design techniques and help ensure that optimal information design is accomplished in the most cost-efficient manner. The major areas of work, or subtasks, within the Information Presentation DRP for FY10 are: 1) Displays, 2) Controls, 3) Procedures and Fault Management, and 4) Human Performance Modeling. The poster will highlight completed and planned work for each subtask.

  2. Information Presentation

    Science.gov (United States)

    Holden, K.L.; Boyer, J.L.; Sandor, A.; Thompson, S.G.; McCann, R.S.; Begault, D.R.; Adelstein, B.D.; Beutter, B.R.; Stone, L.S.

    2009-01-01

    The goal of the Information Presentation Directed Research Project (DRP) is to address design questions related to the presentation of information to the crew. The major areas of work, or subtasks, within this DRP are: 1) Displays, 2) Controls, 3) Electronic Procedures and Fault Management, and 4) Human Performance Modeling. This DRP is a collaborative effort between researchers at Johnson Space Center and Ames Research Center.

  3. Public lighting.

    NARCIS (Netherlands)

    Schreuder, D.A.

    1986-01-01

    The function of public lighting and the relationship between public lighting and accidents are considered briefly as aspects of effective countermeasures. Research needs and recent developments in installation and operational described. Public lighting is an efficient accident countermeasure, but

  4. Analytical applications of ion exchangers

    CERN Document Server

    Inczédy, J

    1966-01-01

    Analytical Applications of Ion Exchangers presents the laboratory use of ion-exchange resins. This book discusses the development in the analytical application of ion exchangers. Organized into 10 chapters, this book begins with an overview of the history and significance of ion exchangers for technical purposes. This text then describes the properties of ion exchangers, which are large molecular water-insoluble polyelectrolytes having a cross-linked structure that contains ionic groups. Other chapters consider the theories concerning the operation of ion-exchange resins and investigate th

  5. The ANSTO high energy heavy ion microprobe

    Science.gov (United States)

    Siegele, Rainer; Cohen, David D.; Dytlewski, Nick

    1999-10-01

    Recently the construction of the ANSTO High Energy Heavy Ion Microprobe (HIMP) at the 10 MV ANTARES tandem accelerator has been completed. The high energy heavy ion microprobe focuses not only light ions at energies of 2-3 MeV, but is also capable of focusing heavy ions at high energies with ME/ q2 values up to 150 MeV amu and greater. First performance tests and results are reported here.

  6. On the ions acceleration via collisionless magnetic reconnection in laboratory plasmas

    Science.gov (United States)

    Cazzola, E.; Curreli, D.; Markidis, S.; Lapenta, G.

    2016-11-01

    This work presents an analysis of the ion outflow from magnetic reconnection throughout fully kinetic simulations with typical laboratory plasma values. A symmetric initial configuration for the density and magnetic field is considered across the current sheet. After analyzing the behavior of a set of nine simulations with a reduced mass ratio and with a permuted value of three initial electron temperatures and magnetic field intensity, the best ion acceleration scenario is further studied with a realistic mass ratio in terms of the ion dynamics and energy budget. Interestingly, a series of shock wave structures are observed in the outflow, resembling the shock discontinuities found in recent magnetohydrodynamic simulations. An analysis of the ion outflow at several distances from the reconnection point is presented, in light of possible laboratory applications. The analysis suggests that magnetic reconnection could be used as a tool for plasma acceleration, with applications ranging from electric propulsion to production of ion thermal beams.

  7. Main magnetic focus ion source with the radial extraction of ions

    CERN Document Server

    Ovsyannikov, V P

    2015-01-01

    In the main magnetic focus ion source, atomic ions are produced in the local ion trap created by the rippled electron beam in focusing magnetic field. Here we present the novel modification of the room-temperature hand-size device, which allows the extraction of ions in the radial direction perpendicular to the electron beam across the magnetic field. The detected X-ray emission evidences the production of Ir$^{44+}$ and Ar$^{16+}$ ions. The ion source can operate as the ion trap for X-ray spectroscopy, as the ion source for the production of highly charged ions and also as the ion source of high brightness.

  8. EFFECT OF DIFFERENT AMOUNTS OF THE NONIONIC DETERGENTS C-10E(5) AND C-12E(5) PRESENT IN ELUENTS FOR ION-EXCHANGE HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY OF INTEGRAL MEMBRANE-PROTEINS OF SENDAI VIRUS

    NARCIS (Netherlands)

    WELLINGWESTER, S; FEIJLBRIEF, M; KOEDIJK, DGAM; BRAAKSMA, MA; DOUMA, BRK; WELLING, GW

    1993-01-01

    Non-ionic detergents (0.03-0.5%) are used as additives to the eluents when integral membrane proteins are subjected to ion-exchange high-performance liquid chromatography (HPIEC). It is not known whether this concentration should bear some relation to the critical micelle concentration (CMC) of a de

  9. Voting Present

    Directory of Open Access Journals (Sweden)

    James Lo

    2013-12-01

    Full Text Available During his time as a state senator in Illinois, Barack Obama voted “Present” 129 times, a deliberate act of nonvoting that subsequently became an important campaign issue during the 2008 presidential elections. In this article, I examine the use of Present votes in the Illinois state senate. I find evidence that Present votes can largely be characterized as protest votes used as a legislative tool by the minority party. Incorporating information from Present votes into a Bayesian polytomous item-response model, I find that this information increases the efficiency of ideal point estimates by approximately 35%. There is little evidence of significant moderation by Obama when Present votes are accounted for, though my results suggest that Obama’s voting record may have moderated significantly before his subsequent election to the U.S. Senate. My results also suggest that because legislative nonvoting may occur for a variety of reasons, naive inclusion of nonvoting behavior into vote choice models may lead to biased results.

  10. Ion Colliders

    CERN Document Server

    Fischer, W

    2014-01-01

    High-energy ion colliders are large research tools in nuclear physics to study the Quark-Gluon-Plasma (QGP). The range of collision energy and high luminosity are important design and operational considerations. The experiments also expect flexibility with frequent changes in the collision energy, detector fields, and ion species. Ion species range from protons, including polarized protons in RHIC, to heavy nuclei like gold, lead and uranium. Asymmetric collision combinations (e.g. protons against heavy ions) are also essential. For the creation, acceleration, and storage of bright intense ion beams, limits are set by space charge, charge change, and intrabeam scattering effects, as well as beam losses due to a variety of other phenomena. Currently, there are two operating ion colliders, the Relativistic Heavy Ion Collider (RHIC) at BNL, and the Large Hadron Collider (LHC) at CERN.

  11. Technical presentation

    CERN Multimedia

    FI Department

    2008-01-01

    RADIOSPARES, the leading catalogue distributor of components (electronic, electrical, automation, etc.) and industrial supplies will be at CERN on Friday 3 October 2008 (Main Building, Room B, from 9.00 a.m. to 3.00 p.m.) to introduce its new 2008/2009 catalogue. This will be the opportunity for us to present our complete range of products in more detail: 400 000 part numbers available on our web site (Radiospares France, RS International, extended range of components from other manufacturers); our new services: quotations, search for products not included in the catalogue, SBP products (Small Batch Production: packaging in quantities adapted to customers’ requirements); partnership with our focus manufacturers; demonstration of the on-line purchasing tool implemented on our web site in conjunction with CERN. RADIOSPARES will be accompanied by representatives of FLUKE and TYCO ELECTRONICS, who will make presentations, demonstrate materials and answer any technical questio...

  12. Overview Presentation

    Science.gov (United States)

    Lytle, John

    2001-01-01

    This report provides an overview presentation of the 2000 NPSS (Numerical Propulsion System Simulation) Review and Planning Meeting. Topics include: 1) a background of the program; 2) 1999 Industry Feedback; 3) FY00 Status, including resource distribution and major accomplishments; 4) FY01 Major Milestones; and 5) Future direction for the program. Specifically, simulation environment/production software and NPSS CORBA Security Development are discussed.

  13. Photo-Catalyzed Rare Earth Materials with Ability to Translate Free Radicals into Negative Ions

    Institute of Scientific and Technical Information of China (English)

    Jin Zongzhe; Zhang Zhili; Wei Gang; Huang Lirong

    2005-01-01

    Materials with function of producing negative ions effection,containing valency-variable rare earth elements and semiconductor oxide,were fabricated.Free radicals produced by the materials were tested.The result shows that the materials can produce quite a few free radicals as·O-2 no matter whether they are under illumination of ultraviolet radiation or under visible light radiation,or under no light radiation, demonstrating semiconductor oxide can be catalysed under the visible light radiation.At the same time the result shows there is direct relation between the number of free radicals and of the negative ion produced by the materials,which meant that during photo-catalyzed and redox process of valency-variable rare earth elements free radicals translate into negative ions. A circular model is presented involving circulating change of valency-variable rare earth elements and water and oxygen absorbed on the surface of materials under the condition of photocatalysis.

  14. Membranes in Lithium Ion Batteries

    Directory of Open Access Journals (Sweden)

    Junbo Hou

    2012-07-01

    Full Text Available Lithium ion batteries have proven themselves the main choice of power sources for portable electronics. Besides consumer electronics, lithium ion batteries are also growing in popularity for military, electric vehicle, and aerospace applications. The present review attempts to summarize the knowledge about some selected membranes in lithium ion batteries. Based on the type of electrolyte used, literature concerning ceramic-glass and polymer solid ion conductors, microporous filter type separators and polymer gel based membranes is reviewed.

  15. Membranes in lithium ion batteries.

    Science.gov (United States)

    Yang, Min; Hou, Junbo

    2012-07-04

    Lithium ion batteries have proven themselves the main choice of power sources for portable electronics. Besides consumer electronics, lithium ion batteries are also growing in popularity for military, electric vehicle, and aerospace applications. The present review attempts to summarize the knowledge about some selected membranes in lithium ion batteries. Based on the type of electrolyte used, literature concerning ceramic-glass and polymer solid ion conductors, microporous filter type separators and polymer gel based membranes is reviewed.

  16. Pionic fusion in light-ion systems

    NARCIS (Netherlands)

    Joulaeizadeh, L.; Gasparic, I.; Amir-Ahmadi, H. R.; Bacelar, J.; Caplar, R.; Eslami-Kalantari, M.; Kalantar-Nayestanaki, N.; Löhner, H.; Mardanpour, H.; Messchendorp, J. G.; Moeini, H.; Ramazani-Moghaddam-Arani, A. A.; Shende, S. V.; Stephan, E.

    2011-01-01

    The role of pions in the nuclear interaction has been studied in pionic fusion experiments using the AGOR accelerator facility at KVI. Pionic fusion is a highly coherent process in which two nuclei fuse to a united nucleus and the available centre-of-mass (C.M.) energy is emitted through the pion ch

  17. Inelastic Light Scattering Processes

    Science.gov (United States)

    Fouche, Daniel G.; Chang, Richard K.

    1973-01-01

    Five different inelastic light scattering processes will be denoted by, ordinary Raman scattering (ORS), resonance Raman scattering (RRS), off-resonance fluorescence (ORF), resonance fluorescence (RF), and broad fluorescence (BF). A distinction between fluorescence (including ORF and RF) and Raman scattering (including ORS and RRS) will be made in terms of the number of intermediate molecular states which contribute significantly to the scattered amplitude, and not in terms of excited state lifetimes or virtual versus real processes. The theory of these processes will be reviewed, including the effects of pressure, laser wavelength, and laser spectral distribution on the scattered intensity. The application of these processes to the remote sensing of atmospheric pollutants will be discussed briefly. It will be pointed out that the poor sensitivity of the ORS technique cannot be increased by going toward resonance without also compromising the advantages it has over the RF technique. Experimental results on inelastic light scattering from I(sub 2) vapor will be presented. As a single longitudinal mode 5145 A argon-ion laser line was tuned away from an I(sub 2) absorption line, the scattering was observed to change from RF to ORF. The basis, of the distinction is the different pressure dependence of the scattered intensity. Nearly three orders of magnitude enhancement of the scattered intensity was measured in going from ORF to RF. Forty-seven overtones were observed and their relative intensities measured. The ORF cross section of I(sub 2) compared to the ORS cross section of N2 was found to be 3 x 10(exp 6), with I(sub 2) at its room temperature vapor pressure.

  18. Detection and identification of 1-methylethyl and methyl radicals generated by irradiating tea tree (Melaleuca alternifolia) oil with visible light (436 nm) in the presence of flavin mononucleotide and ferrous ion.

    Science.gov (United States)

    Mori, H-M; Iwahashi, H

    2013-08-01

    Here, we determined the electron spin resonance (ESR) spectra of standard reaction mixtures (I) containing 25 μM flavin mononucleotide (FMN), 0.018% tea tree (Melaleuca alternifolia) oil, 1.9 M acetonitrile, 20 mM phosphate buffer (pH 7.4), 0.1 M α-(4-pyridyl-1-oxide)-N-tert-butylnitrone (4-POBN), and 1.0 mM FeSO₄(NH₄)₂SO₄ irradiated with 436 nm visible light (7.8 J/cm²). Prominent ESR signals (αN = 1.58 mT and αHβ = 0.26 mT) were detected, suggesting that free radicals form in the standard reaction. In order to know whether singlet oxygen (¹O₂) is involved in the radical formation or not, ESR measurement was performed for the standard D₂O reaction mixture (I) which contained 25 μM FMN, 0.0036% tea tree oil, 1.9 M acetonitrile-d3, 20 mM phosphate buffer (pH 7.4), 0.1 M 4-POBN and 1.0 mM FeSO₄ in D₂O. The ESR peak height of the standard D₂O reaction increased to 169 ± 24% of the control. Thus, ¹O₂ seems to be involved in the formation of the radicals because D₂O increases the lifetime of singlet oxygen. High-performance liquid chromatography-ESR-mass spectrometry analyses detected 1-methylethyl and methyl radicals in the standard reaction. The radicals appear to form through the reaction of ferrous ion with α-terpinene endoperoxide (ascaridole), which generated from the reaction of α-terpinene with ¹O₂. The 1-methylethyl and methyl radicals may exert a pro-oxidant effect under these conditions.

  19. Surface ion trap structures with excellent optical access for quantum information processing

    Science.gov (United States)

    Maunz, P.; Blain, M.; Benito, F.; Chou, C.; Clark, C.; Descour, M.; Ellis, R.; Haltli, R.; Heller, E.; Kemme, S.; Sterk, J.; Tabakov, B.; Tigges, C.; Stick, D.

    2013-05-01

    Microfabricated surface electrode ion traps are necessary for the advancement of trapped ion quantum information processing as it offers a scalable way for realizing complex trap structures capable of storing and controlling many ions. The most promising way of performing two-qubit quantum gates in a chain of trapped ions is to focus laser beams on individual ions of the chain to drive gates. However, in surface ion traps the close proximity of the ions to the surface and the size of the chips usually cannot accommodate the tightly focused laser beams necessary to address individual ions parallel to the chip surface. Here we present a surface electrode ion trap monolithically fabricated in standard silicon technology that implements a linear quadrupole trap on a bowtie shaped chip with a narrow section that is only 1.2 mm wide. Laser beams parallel to the surface can be focused down to a waist of 4 μm with enough separation from the trap chip to prevent light scattering. The trap structure incorporates two Y-junctions for reordering ions and is optimized for quantum information processing. This work was supported by the Intelligence Advanced Research Projects Activity (IARPA). Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the US Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.

  20. Status and Operation of the Linac4 Ion Source Prototypes

    CERN Document Server

    Lettry, J; Andersson, P; Bertolo, S; Butterworth, A; Coutron, Y; Dallocchio, A; Chaudet, E; Gil-Flores, J; Guida, R; Hansen, J; Koszar, I; Mahner, E; Mastrostefano, C; Mathot, S; Mattei, S; Midttun, O; Moyret, P; Nisbet, D; O’Neil, M; Paoluzzi, M; Pasquino, C; Pereira, H; Rochez, J; Sanchez Alvarez, J; Sanchez Arias, J; Scrivens, R; Steyaert, D; Thaus, N; Hatayama, A; Nishida, K; Shibata, T; Yamamot, T; Otha, M

    2014-01-01

    CERN’s Linac4 45 kV H- ion sources prototypes are installed at a dedicated ion source test stand and in the Linac4 tunnel. The operation of the pulsed hydrogen injection, RF sustained plasma and pulsed high voltages are described. The first experimental results of two prototypes relying on 2MHz RF- plasma heating are presented. The plasma is ignited via capacitive coupling, and sustained by inductive coupling. The light emitted from the plasma is collected by viewports pointing to the plasma chamber wall in the middle of the RF solenoid and to the plasma chamber axis. Preliminary measurements of optical emission spectroscopy and photometry of the plasma have been performed. The design of a cesiated ion source is presented. The volume source has produced a 45 keV H- beam of 16-22 mA which has successfully been used for the commissioning of the LEBT, RFQ and chopper of Linac4.