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Sample records for spontaneously generated light

  1. Spontaneous light emission from fibers in MINOS

    International Nuclear Information System (INIS)

    Avvakumov, S.; Barrett, W.L.; Belias, T.; Bower, C.; Erwin, A.; Kordosky, M.; Lang, K.; Lee, R.; Liu, J.; Miller, W.; Mualem, L.; Nichol, R.; Nelson, J.; Pearce, G.; Proga, M.; Rebel, B.; Ruddick, K.; Smith, C.; Thomas, J.; Vahle, P.; Webb, R.

    2005-01-01

    We report on the observation and measurements of unexpected background rates in the MINOS Far Detector. The noise level at the Far Detector is significantly greater than that expected from natural radioactivity and intrinsic photomultiplier dark current. We have conducted a series of additional tests which demonstrate that the excess rate is caused by spontaneous light emission in the wavelength-shifting fibers, which are used to read out signals from scintillator strips. This noise due to fibers exhibits an exponential fall off with time with a decay time constant of the order of 100 days

  2. Spontaneous prediction error generation in schizophrenia.

    Directory of Open Access Journals (Sweden)

    Yuichi Yamashita

    Full Text Available Goal-directed human behavior is enabled by hierarchically-organized neural systems that process executive commands associated with higher brain areas in response to sensory and motor signals from lower brain areas. Psychiatric diseases and psychotic conditions are postulated to involve disturbances in these hierarchical network interactions, but the mechanism for how aberrant disease signals are generated in networks, and a systems-level framework linking disease signals to specific psychiatric symptoms remains undetermined. In this study, we show that neural networks containing schizophrenia-like deficits can spontaneously generate uncompensated error signals with properties that explain psychiatric disease symptoms, including fictive perception, altered sense of self, and unpredictable behavior. To distinguish dysfunction at the behavioral versus network level, we monitored the interactive behavior of a humanoid robot driven by the network. Mild perturbations in network connectivity resulted in the spontaneous appearance of uncompensated prediction errors and altered interactions within the network without external changes in behavior, correlating to the fictive sensations and agency experienced by episodic disease patients. In contrast, more severe deficits resulted in unstable network dynamics resulting in overt changes in behavior similar to those observed in chronic disease patients. These findings demonstrate that prediction error disequilibrium may represent an intrinsic property of schizophrenic brain networks reporting the severity and variability of disease symptoms. Moreover, these results support a systems-level model for psychiatric disease that features the spontaneous generation of maladaptive signals in hierarchical neural networks.

  3. Light Beam Generation

    DEFF Research Database (Denmark)

    2007-01-01

    The invention relates to a method and a system for synthesizing a set of controllable light beams by provision of a system for synthesizing a set of light beams, comprising a spatially modulated light source for generation of electromagnetic radiation with a set of replicas of a predetermined......(x-xs, y-ys), a Fourier transforming lens for Fourier transforming the electromagnetic radiation, a first spatial light modulator for phase shifting the Fourier transformed electromagnetic radiation with the phase -F(u, v) of S*, S* is the complex conjugate of the Fourier transformed symbol s, a Fourier...... transforming lens for Inverse Fourier transforming the spatially modulated radiation, whereby a set of light beams are formed propagating through the inverse Fourier plane (x', y') at desired positions (x's, y's), and a controller for controlling the position of a replica of the symbol, s, for movement...

  4. Next Generation Light Robotics

    DEFF Research Database (Denmark)

    Glückstad, Jesper

    Light Robotics is a new field of research where ingredients from photonics, nanotechnology and biotechnology are put together in new ways to realize light-driven robotics at the smallest scales to solve major challenges primarily within the nanobio-domain but not limited hereto. Exploring the full...... potential of this new ‘drone-like’ light-printed, light-driven, light-actuated micro- and nano-robotics in challenging geometries requires a versatile and real-time reconfigurable light addressing that can dynamically track a plurality of tiny tools in 3D to ensure real-time continuous light...

  5. Spontaneous generation in medieval Jewish philosophy and theology.

    Science.gov (United States)

    Gaziel, Ahuva

    2012-01-01

    The concept of life forms emerging from inanimate matter--spontaneous generation--was widely accepted until the nineteenth century. Several medieval Jewish scholars acknowledged this scientific theory in their philosophical and religious contemplations. Quite interestingly, it served to reinforce diverse, or even opposite, theological conclusions. One approach excluded spontaneously-generated living beings form the biblical account of creation or the story of the Deluge. Underlying this view is an understanding that organisms that generate spontaneously evolve continuously in nature and, therefore, do not require divine intervention in their formation or survival during disastrous events. This naturalistic position reduces the miraculous dimension of reality. Others were of the opinion that spontaneous generation is one of the extraordinary marvels exhibited in this world and, accordingly, this interpretation served to accentuate the divine aspect of nature. References to spontaneous generation also appear in legal writings, influencing practical applications such as dietary laws and actions forbidden on the Sabbath.

  6. Controlling spontaneous emission of light by photonic crystals

    DEFF Research Database (Denmark)

    Lodahl, Peter

    2005-01-01

    Photonic bandgap crystals were proposed almost two decades ago as a unique tool for controlling propagation and emission of light. Since then the research field of photonic crystals has exploded and many beautiful demonstrations of the use of photonic crystals and fibers for molding light...... propagation have appeared that hold great promises for integrated optics. These major achievements solidly demonstrate the ability to control propagation of light. In contrast, an experimental demonstration of the use of photonic crystals for timing the emission of light has so far lacked. In a recent...... publication in Nature, we have demonstrated experimentally that both the direction and time of spontaneous emission can be controlled, thereby confirming the original proposal by Eli Yablonovich that founded the field of photonic crystals. We believe that this work opens new opportunities for solid...

  7. Model for spontaneous generation of gauge structure and matter

    International Nuclear Information System (INIS)

    Chan, H.-M.; Tsou, S.T.

    1983-09-01

    Based on a special topological property of R 4 , it is argued that in a 4 + 1 - dimensional pure Einstein theory, the world will tend to find itself in a Kaluza-Klein mode with one compactified spatial dimension populated by singly charged solitons, so that both gauge structure and matter are spontaneously generated. (author)

  8. Method of generating chemiluminescent light

    Science.gov (United States)

    Spurlin, S.R.; Yeung, E.S.

    1986-03-11

    A method of chemiluminescently determining a sulfide which is either hydrogen sulfide or methyl mercaptan by reacting the sulfide with chlorine dioxide at low pressure and under conditions which allow a longer reaction time in emission of a single photon for every two sulfide containing species, and thereafter, chemiluminescently detecting and determining the sulfide. The invention also relates not only to the detection method, but the novel chemical reaction that generates chemiluminescent light and a specifically designed chemiluminescence detection cell for the reaction. 4 figs.

  9. 30 years of squeezed light generation

    DEFF Research Database (Denmark)

    Andersen, Ulrik Lund; Gehring, Tobias; Marquardt, Christoph

    2016-01-01

    Squeezed light generation has come of age. Significant advances on squeezed light generation have been made over the last 30 years—from the initial, conceptual experiment in 1985 till today’s top-tuned, application-oriented setups. Here we review the main experimental platforms for generating...... quadrature squeezed light that have been investigated in the last 30 years....

  10. Light extraction from organic light-emitting diodes enhanced by spontaneously formed buckles

    Science.gov (United States)

    Koo, Won Hoe; Jeong, Soon Moon; Araoka, Fumito; Ishikawa, Ken; Nishimura, Suzushi; Toyooka, Takehiro; Takezoe, Hideo

    2010-04-01

    Most of the light in conventional organic light-emitting diodes is confined to high-refractive-index layers (such as an organic medium, indium tin oxide and glass substrate) resulting in a low light extraction efficiency of ~20% (refs 1,2). Many studies have used wavelength-scale periodic gratings to increase the external efficiency of organic light-emitting diodes. However, the efficiency is only enhanced at particular wavelengths satisfying the Bragg condition. Here, we demonstrate that a quasi-periodic buckling structure with broad distribution and directional randomness can enhance the light extraction efficiency without introducing spectral changes and directionality. Organic light-emitting diodes corrugated by buckles showed improved current and power efficiencies and an electroluminescence spectrum enhanced by at least a factor of two across the entire visible wavelength regime. These buckling patterns are formed spontaneously on elastic materials with a thin metallic film. The buckled organic light-emitting diode devices are practical and attractive for use in fabricating full colour and white organic light-emitting diodes.

  11. Amplified spontaneous emission pulses for high-power supercontinuum generation

    Directory of Open Access Journals (Sweden)

    Huan Huan Liu

    2016-03-01

    Full Text Available The authors demonstrate an incoherent light source based on a reflective semiconductor optical amplifier as pump for high-power supercontinuum generation for the first time. The obtained power level is about 160 mW and 20 dB spectral bandwidth is around 170 nm.

  12. Effects of spontaneously generated coherence on the group velocity in a V system

    International Nuclear Information System (INIS)

    Bai Yanfeng; Guo Hong; Han, Dingan; Sun Hui

    2005-01-01

    We show how the application of an incoherent pumping can produce a variety of effects on the propagation of a weak electromagnetic pulse in a V system with spontaneously generated coherence (SGC). There exists an incoherent pumping rate which makes the group velocity reach the extremum near the region of two-photon resonant excitation. The existence of SGC is just the cause for the occurrence of the extremum, and it may also be regarded as a knob which can be used to manipulate light propagation from subluminal to superluminal

  13. Origin of spontaneous wave generation in an oscillatory chemical system

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Yi-Xue; Foerster, P.; Ross, J. [Stanford Univ., CA (United States)

    1992-10-29

    The origin of spontaneously generated chemical waves in an oscillatory Belousov-Zhabotinskii reaction has been investigated by numerical calculations of the deterministic reaction-diffusion equations of a modified Oregonator model and by equilibrium stochastic calculations. From numerical calculations, we obtain threshold perturbations in the phase of oscillations and in the concentrations of HBrO{sub 2} and Br{sup {minus}} within areas of space with varying radii necessary to initiate trigger waves. Inward propagating trigger waves initiated by a phase shift in the perturbed region with respect to the bulk solution have been observed in the calculations for the first time. Perturbations smaller than the threshold perturbations or in regions with smaller radii lead to phase-diffusion waves. Our equilibrium stochastic calculations show that the recurrence time for a thermal fluctuation to induce a change in the HBrO{sub 2} concentration of sufficient magnitude within a sufficient volume for a trigger wave to propagate is many orders of magnitude larger than the observation time of traveling wave experiments. We concluded that an internal thermal fluctuation is highly unlikely to generate a trigger wave in an oscillatory chemical solution. 22 refs., 5 figs., 7 tabs.

  14. The next generation of ultraviolet light technologies

    International Nuclear Information System (INIS)

    Roy, K.A.

    1990-01-01

    According to this article, the next generation of ultraviolet (UV) light technologies into the environmental spotlight. Researchers have long recognized the potential of UV light, nestled between the longer radiation wavelengths of the visible spectrum and the shorter ones in the x-ray region, to effect chemical change. Environmentally, UV light made its debut as a water purification tool. As the technology improved, researchers incorporated UV light in wastewater treatment systems and, later, in remediation techniques

  15. Terahertz wave generation from spontaneously formed nanostructures in silver nanoparticle ink.

    Science.gov (United States)

    Kato, Kosaku; Takano, Keisuke; Tadokoro, Yuzuru; Nakajima, Makoto

    2016-05-01

    We demonstrate terahertz pulse generation from silver nanoparticle ink, originally developed for printed electronics, under irradiation by femtosecond laser pulses. Using metal nanoparticle ink, metallic nanostructures can be easily made in a large area without lithographic techniques. Terahertz pulses were emitted from the baked ink, having spontaneously formed nanostructures of ∼100  nm. From the results of the baking temperature dependence and the polarization measurement, the terahertz generation is attributed to the nonlinear polarization induced by the enhanced local fields around these nanostructures. This study paves the way for the future development of terahertz emitters which have resonances in both the near-infrared light and the terahertz wave, by combining micrometer-scale structures drawn by an inkjet printer and nanometer-scale structures formed during the baking process.

  16. Influence of local field on spontaneous light emission by nanoparticles

    DEFF Research Database (Denmark)

    Keller, Ole; Lozovski, V.; Iezhokin, I.

    2009-01-01

    A self-consistent approach based on the local-field concept has been proposed to calculate the direction patterns of light emission by nanoparticles with various shapes. The main idea of the method consists in constructing self-consistent equations for the electromagnetic field at any point of th...... demonstrated to interact as almost point dipoles at distances that exceed their linear dimensions. This fact can be used to substantiate applications of the dipole approximation to studying the optical properties of submonolayer molecular coatings.......A self-consistent approach based on the local-field concept has been proposed to calculate the direction patterns of light emission by nanoparticles with various shapes. The main idea of the method consists in constructing self-consistent equations for the electromagnetic field at any point...

  17. Influence of local field on spontaneous light emission by nanoparticles

    DEFF Research Database (Denmark)

    Keller, Ole; Lozovski, V.; Iezhokin, I.

    2009-01-01

    A self-consistent approach based on the local-field concept has been proposed to calculate the direction patterns of light emission by nanoparticles with various shapes. The main idea of the method consists in constructing self-consistent equations for the electromagnetic field at any point...... demonstrated to interact as almost point dipoles at distances that exceed their linear dimensions. This fact can be used to substantiate applications of the dipole approximation to studying the optical properties of submonolayer molecular coatings....

  18. White Light Generation in Human Saliva

    Science.gov (United States)

    Santhosh, C.; Dharmadhikari, A. K.; Dharmadhikari, J. A.; Alti, K.; Mathur, D.

    2011-07-01

    Interaction of intense, femto-second pulses of infrared light (800 nm) with water generates white light supercontinuum due to nonlinear optical effects. This supercontinuum was found to be suppressed by the addition of alpha amylase, a major protein in the human saliva. We have studied the suppression of supper continuum by human saliva, collected from healthy subjects with and without smoking habits. Suppression of the blue-sided components was observed significantly in non-smokers saliva than chain smokers.

  19. Contribution of spontaneous polarization and its fluctuations to refraction of light in ferroelectrics

    Czech Academy of Sciences Publication Activity Database

    Markovin, P.A.; Trepakov, Vladimír; Tagantsev, A. K.; Dejneka, Alexandr; Andreev, D. A.

    2016-01-01

    Roč. 58, č. 1 (2016), 134-139 ISSN 1063-7834 R&D Projects: GA ČR GA15-13778S Institutional support: RVO:68378271 Keywords : contribution * spontaneous polarization * fluctuations * refraction * light * ferroelectrics Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 0.860, year: 2016

  20. Slow-light enhancement of spontaneous emission in active photonic crystal waveguides

    DEFF Research Database (Denmark)

    Ek, Sara; Chen, Yaohui; Semenova, Elizaveta

    2012-01-01

    Photonic crystal defect waveguides with embedded active layers containing single or multiple quantum wells or quantum dots have been fabricated. Spontaneous emission spectra are enhanced close to the bandedge, consistently with the enhancement of gain by slow light effects. These are promising...

  1. Simulating spontaneous parametric down-conversion using classical light: Conference paper

    CSIR Research Space (South Africa)

    Zhang, Y

    2014-08-01

    Full Text Available of SPIE Volume 9194, Laser Beam Shaping XV, San Diego USA, August 2014 Simulating spontaneous parametric down-conversion using classical light Yingwen Zhanga, Melanie McLarena,b, Filippus S. Rouxa and Andrew Forbesa,b aCSIR National Laser Centre...

  2. Spontaneous Rayleigh-Brillouin scattering of ultraviolet light in nitrogen, dry and moist air

    NARCIS (Netherlands)

    Witschas, B.; Vieitez, M.O.; van Duijn, E.-J.; Reitebuch, O.; Van de Water, W.; Ubachs, W.M.G.

    2010-01-01

    Atmospheric lidar techniques for the measurement of wind, temperature, and optical properties of aerosols rely on the exact knowledge of the spectral line shape of the scattered laser light on molecules. We report on spontaneous Rayleigh-Brillouin scattering measurements in the ultraviolet at a

  3. Spontaneous generation and reversals of mean flows in a convectively-generated internal gravity wave field

    Science.gov (United States)

    Couston, Louis-Alexandre; Lecoanet, Daniel; Favier, Benjamin; Le Bars, Michael

    2017-11-01

    We investigate via direct numerical simulations the spontaneous generation and reversals of mean zonal flows in a stably-stratified fluid layer lying above a turbulent convective fluid. Contrary to the leading idealized theories of mean flow generation by self-interacting internal waves, the emergence of a mean flow in a convectively-generated internal gravity wave field is not always possible because nonlinear interactions of waves of different frequencies can disrupt the mean flow generation mechanism. Strong mean flows thus emerge when the divergence of the Reynolds stress resulting from the nonlinear interactions of internal waves produces a strong enough anti-diffusive acceleration for the mean flow, which, as we will demonstrate, is the case when the Prandtl number is sufficiently low, or when the energy input into the internal wavefield by the convection and density stratification are sufficiently large. Implications for mean zonal flow production as observed in the equatorial stratospheres of the Earth, Saturn and Jupiter, and possibly occurring in other geophysical systems such as planetary and stellar interiors will be briefly discussed. Funding provided by the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation program through Grant Agreement No. 681835-FLUDYCO-ERC-2015-CoG.

  4. Quantitative analysis of directional spontaneous emission spectra from light sources in photonic crystals

    International Nuclear Information System (INIS)

    Nikolaev, Ivan S.; Lodahl, Peter; Vos, Willem L.

    2005-01-01

    We have performed angle-resolved measurements of spontaneous-emission spectra from laser dyes and quantum dots in opal and inverse opal photonic crystals. Pronounced directional dependencies of the emission spectra are observed: angular ranges of strongly reduced emission adjoin with angular ranges of enhanced emission. It appears that emission from embedded light sources is affected both by the periodicity and by the structural imperfections of the crystals: the photons are Bragg diffracted by lattice planes and scattered by unavoidable structural disorder. Using a model comprising diffuse light transport and photonic band structure, we quantitatively explain the directional emission spectra. This work provides detailed understanding of the transport of spontaneously emitted light in real photonic crystals, which is essential in the interpretation of quantum optics in photonic-band-gap crystals and for applications wherein directional emission and total emission power are controlled

  5. Photoelectrochemical water splitting and hydrogen generation by a spontaneously formed InGaN nanowall network

    Energy Technology Data Exchange (ETDEWEB)

    Alvi, N. H., E-mail: nhalvi@isom.upm.es, E-mail: r.noetzel@isom.upm.es; Soto Rodriguez, P. E. D.; Kumar, Praveen; Gómez, V. J.; Aseev, P.; Nötzel, R., E-mail: nhalvi@isom.upm.es, E-mail: r.noetzel@isom.upm.es [ISOM Institute for Systems Based on Optoelectronics and Microtechnology, ETSI Telecomunicación, Universidad Politécnica de Madrid, Ciudad Universitaria s/n, 28040 Madrid (Spain); Alvi, A. H. [Department of Physics, Government College University, Faisalabad (Pakistan); Alvi, M. A. [Department of Chemistry, Government College University, Faisalabad (Pakistan); Willander, M. [Department of Science and Technology (ITN), Campus Norrköping, Linköping University, 60174 Norrköping (Sweden)

    2014-06-02

    We investigate photoelectrochemical water splitting by a spontaneously formed In-rich InGaN nanowall network, combining the material of choice with the advantages of surface texturing for light harvesting by light scattering. The current density for the InGaN-nanowalls-photoelectrode at zero voltage versus the Ag/AgCl reference electrode is 3.4 mA cm{sup −2} with an incident-photon-to-current-conversion efficiency (IPCE) of 16% under 350 nm laser illumination with 0.075 W·cm{sup −2} power density. In comparison, the current density for a planar InGaN-layer-photoelectrode is 2 mA cm{sup −2} with IPCE of 9% at zero voltage versus the Ag/AgCl reference electrode. The H{sub 2} generation rates at zero externally applied voltage versus the Pt counter electrode per illuminated area are 2.8 and 1.61 μmol·h{sup −1}·cm{sup −2} for the InGaN nanowalls and InGaN layer, respectively, revealing ∼57% enhancement for the nanowalls.

  6. Withdrawal of voluntary inhibition unravels the off state of the spontaneous blink generator.

    Science.gov (United States)

    Moraitis, Timoleon; Ghosh, Arko

    2014-12-01

    Involuntary movements such as spontaneous eye blinks can be successfully inhibited at will. Little do we know how the voluntary motor circuits countermand spontaneous blinks. Do the voluntary inhibitory commands act to pause or to turn off the endogenous blink generator, or does inhibition intersect and counter the generator׳s excitatory outputs? In theory, the time taken for the system to generate an after-inhibition blink will reflect onto the form of inhibition. For instance, if voluntary commands were to turn the blink generator off then the after-blink latency would be fixed to the inhibition offset and reflect the time it takes for the generator to rebound and turn on. In this study we measured the after-blink latency from the offset of voluntary inhibition. Volunteers inhibited their blinks in response to sound tones of randomly varying durations. At the offset volunteers withdrew the inhibition and relaxed. Interestingly, the spontaneous after-blinks were fixed to the offset of the inhibition as if the generator rebounded from an off state. The after-blink latency was not related to the duration of the inhibition, and inhibiting even for a small fraction of the mean inter-blink interval generated an after-blink time-locked to the inhibition offset. Interestingly, the insertion of voluntary blinks after inhibition further altered the blink generator by delaying the spontaneous after-blinks. We propose that the inhibition of spontaneous blinks at the level of the generator allows for highly effective voluntary countermanding. Nevertheless, the withdrawal of such inhibition was strongly associated with motor excitation. Copyright © 2014 Elsevier Ltd. All rights reserved.

  7. Triple photonic band-gap structure dynamically induced in the presence of spontaneously generated coherence

    International Nuclear Information System (INIS)

    Gao Jinwei; Bao Qianqian; Wan Rengang; Cui Cuili; Wu Jinhui

    2011-01-01

    We study a cold atomic sample coherently driven into the five-level triple-Λ configuration for attaining a dynamically controlled triple photonic band-gap structure. Our numerical calculations show that three photonic band gaps with homogeneous reflectivities up to 92% can be induced on demand around the probe resonance by a standing-wave driving field in the presence of spontaneously generated coherence. All these photonic band gaps are severely malformed with probe reflectivities declining rapidly to very low values when spontaneously generated coherence is gradually weakened. The triple photonic band-gap structure can also be attained in a five-level chain-Λ system of cold atoms in the absence of spontaneously generated coherence, which however requires two additional traveling-wave fields to couple relevant levels.

  8. Second Harmonic Generation of Unpolarized Light

    Science.gov (United States)

    Ding, Changqin; Ulcickas, James R. W.; Deng, Fengyuan; Simpson, Garth J.

    2017-11-01

    A Mueller tensor mathematical framework was applied for predicting and interpreting the second harmonic generation (SHG) produced with an unpolarized fundamental beam. In deep tissue imaging through SHG and multiphoton fluorescence, partial or complete depolarization of the incident light complicates polarization analysis. The proposed framework has the distinct advantage of seamlessly merging the purely polarized theory based on the Jones or Cartesian susceptibility tensors with a more general Mueller tensor framework capable of handling partial depolarized fundamental and/or SHG produced. The predictions of the model are in excellent agreement with experimental measurements of z -cut quartz and mouse tail tendon obtained with polarized and depolarized incident light. The polarization-dependent SHG produced with unpolarized fundamental allowed determination of collagen fiber orientation in agreement with orthogonal methods based on image analysis. This method has the distinct advantage of being immune to birefringence or depolarization of the fundamental beam for structural analysis of tissues.

  9. Toward a fourth-generation light source

    International Nuclear Information System (INIS)

    Moncton, D. E.

    1999-01-01

    Historically, x-ray research has been propelled by the existence of urgent and compelling scientific questions and the push of powerful and exquisite source technology. These two factors have gone hand in hand since Rontgen discovered x-rays. Here we review the progress being made with existing third-generation synchrotron-radiation light sources and the prospects for a fourth-generation light source with dramatically improved laser-like beam characteristics. The central technology for high-brilliance x-ray beams is the x-ray undulator, a series of alternating-pole magnets situated above and below the particle beam. When the particle beam is oscillated by the alternating magnetic fields, a set of. interacting and interfering wave fronts is produced, which leads to an x-ray beam with extraordinary properties. Third-generation sources of light in the hard x-ray range have been constructed at three principal facilities: the European Synchrotrons Radiation Facility (ESRF) in France; the Super Photon Ring 8-GeV (or Spring-8) in Japan; and the Advanced Photon Source (APS) in the US. Undulator technology is also used on a number of low-energy machines for radiation in the ultraviolet and soft x-ray regimes. At the APS, these devices exceed all of our original expectations for beam brilliance, tunability, spectral range, and operational flexibility. Shown in Fig. 1 are the tuning curves of the first few harmonics, showing x-ray production from a few kV to better than 40 keV. High-brilliance radiation extends to over 100 keV

  10. The epileptic human hippocampal cornu ammonis 2 region generates spontaneous interictal-like activity in vitro.

    Science.gov (United States)

    Wittner, Lucia; Huberfeld, Gilles; Clémenceau, Stéphane; Eross, Loránd; Dezamis, Edouard; Entz, László; Ulbert, István; Baulac, Michel; Freund, Tamás F; Maglóczky, Zsófia; Miles, Richard

    2009-11-01

    The dentate gyrus, the cornu ammonis 2 region and the subiculum of the human hippocampal formation are resistant to the cell loss associated with temporal lobe epilepsy. The subiculum, but not the dentate gyrus, generates interictal-like activity in tissue slices from epileptic patients. In this study, we asked whether a similar population activity is generated in the cornu ammonis 2 region and examined the electrophysiological and neuroanatomical characteristics of human epileptic cornu ammonis 2 neurons that may be involved. Hippocampal slices were prepared from postoperative temporal lobe tissue derived from epileptic patients. Field potentials and multi-unit activity were recorded in vitro using multiple extracellular microelectrodes. Pyramidal cells were characterized in intra-cellular records and were filled with biocytin for subsequent anatomy. Fluorescent immunostaining was made on fixed tissue against the chloride-cation cotransporters sodium-potassium-chloride cotransporter-1 and potassium-chloride cotransporter-2. Light and electron microscopy were used to examine the parvalbumin-positive perisomatic inhibitory network. In 15 of 20 slices, the hippocampal cornu ammonis 2 region generated a spontaneous interictal-like activity, independently of population events in the subiculum. Most cornu ammonis 2 pyramidal cells fired spontaneously. All cells fired single action potentials and burst firing was evoked in three cells. Spontaneous excitatory postsynaptic potentials were recorded in all cells, but hyperpolarizing inhibitory postsynaptic potentials were detected in only 27% of the cells. Two-thirds of cornu ammonis 2 neurons showed depolarizing responses during interictal-like events, while the others were inhibited, according to the current sink in the cell body layer. Two biocytin-filled cells both showed a pyramidal-like morphology with axons projecting to the cornu ammonis 2 and cornu ammonis 3 regions. Expression of sodium

  11. Soluble epoxide hydrolase in the generation and maintenance of high blood pressure in spontaneously hypertensive rats

    NARCIS (Netherlands)

    Koeners, Maarten P.; Wesseling, Sebastiaan; Ulu, Arzu; Lopez Sepulveda, Rocio; Morisseau, Christophe; Braam, Branko; Hammock, Bruce D.; Joles, Jaap A.

    Koeners MP, Wesseling S, Ulu A, Sepulveda RL, Morisseau C, Braam B, Hammock BD, Joles JA. Soluble epoxide hydrolase in the generation and maintenance of high blood pressure in spontaneously hypertensive rats. Am J Physiol Endocrinol Metab 300: E691-E698, 2011. First published January 25, 2011; doi:

  12. The entangled photons generation in third order nonlinearity of spontaneous parametric down conversion by whispering gallery mode resonator

    Science.gov (United States)

    Cao, Jingming; Xiaver, Jolly

    2017-10-01

    We manipulated the simulation and apparatus to generate the entangled quantum photons by the enhanced higher quality factor in waveguide of whispering gallery mode resonator in silica microsphere. As the several nonlinear optics effects have been validated in micro-disk (lithium niobate materials based), others micro-cavity (microfiber and micro ring on the chip) and second harmonic generation (SHG) on the surface of silica microsphere because of the characterization of enhanced higher quality factor Q and smaller volume mode in these resonator. However until now for the second third nonlinearity of spontaneous parametric down conversion (SPDC), third order nonlinearity of spontaneous parametric down conversion (TOSPDC) and spontaneous four wave mixing (SFWM) in whispering gallery mode (WGM) resonator of silica microsphere rarely have not been fully investigated and verified to generate the triple and pair entangled photons where are widely applied on the applications of biosensor, quantum communications and spectroscopy, respectively. Specially, the features of silica microsphere have attracted many applications due to the simple fabrication, simplified materials melted by silica fiber. The work we demonstrated in this paper based on the breaking of the dispersion rules to make perfect phase matching in normal dispersion in silica microsphere depending on the blue laser spectrum in visible spectrum, then manipulated the modified size of microsphere to detune the pump laser of free spectral range (FSR) and both shift the geometrical dispersion are characterized in the variation of FSR given by (see PDF for equation), where n is refractive index, R is the microspheres radius and m is mode numbers in resonator, to compensate the materials dispersion given by (see PDF for equation), where c is the speed of light and λ is pump laser wavelength to fulfill the perfect phase matching in parametric down conversion regimes and the modeling fabrication coupling results also

  13. A green-light-emitting, spontaneously blinking fluorophore based on intramolecular spirocyclization for dual-colour super-resolution imaging.

    Science.gov (United States)

    Uno, Shin-Nosuke; Kamiya, Mako; Morozumi, Akihiko; Urano, Yasuteru

    2017-12-19

    We have developed the first green-light-emitting, spontaneously blinking fluorophore (SBF), HEtetTFER. In combination with our near-infrared-light-emitting SBF (HMSiR), HEtetTFER allows dual-colour single-molecule localization microscopy (SMLM) in buffer solution without any additive and without photoactivation.

  14. The Role of Cellular Coupling in the Spontaneous Generation of Electrical Activity in Uterine Tissue

    Science.gov (United States)

    Xu, Jinshan; Menon, Shakti N.; Singh, Rajeev; Garnier, Nicolas B.; Sinha, Sitabhra; Pumir, Alain

    2015-01-01

    The spontaneous emergence of contraction-inducing electrical activity in the uterus at the beginning of labor remains poorly understood, partly due to the seemingly contradictory observation that isolated uterine cells are not spontaneously active. It is known, however, that the expression of gap junctions increases dramatically in the approach to parturition, by more than one order of magnitude, which results in a significant increase in inter-cellular electrical coupling. In this paper, we build upon previous studies of the activity of electrically excitable smooth muscle cells (myocytes) and investigate the mechanism through which the coupling of these cells to electrically passive cells results in the generation of spontaneous activity in the uterus. Using a recently developed, realistic model of uterine muscle cell dynamics, we investigate a system consisting of a myocyte coupled to passive cells. We then extend our analysis to a simple two-dimensional lattice model of the tissue, with each myocyte being coupled to its neighbors, as well as to a random number of passive cells. We observe that different dynamical regimes can be observed over a range of gap junction conductances: at low coupling strength, corresponding to values measured long before delivery, the activity is confined to cell clusters, while the activity for high coupling, compatible with values measured shortly before delivery, may spread across the entire tissue. Additionally, we find that the system supports the spontaneous generation of spiral wave activity. Our results are both qualitatively and quantitatively consistent with observations from in vitro experiments. In particular, we demonstrate that the increase in inter-cellular electrical coupling observed experimentally strongly facilitates the appearance of spontaneous action potentials that may eventually lead to parturition. PMID:25793276

  15. Spontaneous mutability and light-induced mutagenesis in Salmonella typhimurium: effects of an R-plasmid

    International Nuclear Information System (INIS)

    Valdivia, L.

    1979-01-01

    The UV-protecting plasmid R46 was transferred by conjugation to a genetically marked mouse-virulent Salmonella typhimurium strain, not derived from LT2; in this host the plasmid conferred UV protection and enhanced UV mutagenesis just as it does in LT2 lines. Tra - derivatives of R46 encountered during transduction retained UV-protecting and mutagenesis-enhancing ability. Stored strains carrying the R46-derived plasmids with strong mutator effect but not UV-protecting had lost most of their original streptomycin resistance but were slightly resistant to spectinomycin; attempts to transfer such plasmids failed. R46 enhanced the weak mutagenic effect of visible light on several his and trp mutants of strain LT2, including some whose frequency of spontaneous reversion was not increased by the plasmid. A mutagenic effect was produced by visible-light irradiation of hisG46(R46), either growing cells or nonmultiplying (histidine-deprived cells at 10 0 C). Presence of catalase or cyanide during irradiation did not prevent mutagenesis, which excludes some hypothetical mechanisms. Visible-light irradiation of hisG46 or hisG46(R46) under strict anaerobiosis had little or no mutagenic effect (controls showed that revertants if produced would have been detected). This is as expected if visible-light irradiation in air causes photodynamic damage to DNA and mutations are produced during error-prone, plasmid-enhanced repair

  16. Effects of imatinib mesylate on the spontaneous activity generated by the guinea-pig prostate.

    Science.gov (United States)

    Lam, Michelle; Dey, Anupa; Lang, Richard J; Exintaris, Betty

    2013-08-01

    What's known on the subject? and what does the study add?: Several studies have examined the functional role of tyrosine kinase receptors in the generation of spontaneous activity in various segments of the gastrointestinal and urogenital tracts through the application of its inhibitor, imatinib mesylate (Glivec®), but results are fairly inconsistent. This is the first study detailing the effects of imatinib mesylate on the spontaneous activity in the young and ageing prostate gland. As spontaneous electrical activity underlies the spontaneous rhythmic prostatic contractions that occur at rest, elucidating the mechanisms involved in the regulation of the spontaneous electrical activity and the resultant phasic contractions could conceivably lead to the identification of better targets and the development of more specific therapeutic agents to treat prostate conditions. To investigate the effect of imatinib mesylate, a tyrosine kinase receptor inhibitor, in the generation of spontaneous electrical and contractile activity in the young and ageing guinea-pig prostate. Standard tension and intracellular recording were used to measure spontaneous contractions and slow waves, respectively from the guinea-pig prostate at varying concentrations of imatinib mesylate (1-50 μm). Imatinib mesylate (1-10 μm), did not significantly affect slow waves recorded in the prostate of both age groups but at 50 μm, the amplitude of slow waves from the ageing guinea-pig prostate was significantly reduced (P imatinib mesylate attenuated the amplitude and slowed the frequency of contractions in ageing guinea-pigs to 5.15% and 3.3% at 1 μm (n = 6); 21.1% and 20.8% at 5 μm (n = 8); 58.4% and 8.8% at 10 μm (n = 11); 72.7% and 60% at 50 μm (n = 5). A significant reduction in contractions but persistence of slow waves suggests imatinib mesylate may affect the smooth muscle contractile mechanism. Imatinib mesylate also significantly reduced contractions in the prostates of younger guinea

  17. Putative role of border cells in generating spontaneous morphological activity within Kölliker's organ.

    Science.gov (United States)

    Dayaratne, M W Nishani; Vlajkovic, Srdjan M; Lipski, Janusz; Thorne, Peter R

    2015-12-01

    Kölliker's organ is a transient epithelial structure, comprising a major part of the organ of Corti during pre-hearing stages of development. The auditory system is spontaneously active during development, which serves to retain and refine neural connections. Kölliker's organ is considered a key candidate for generating such spontaneous activity, most likely through purinergic (P2 receptor) signalling and inner hair cell (IHC) activation. Associated with the spontaneous neural activity, ATP released locally by epithelial cells induces rhythmic morphological changes within Kölliker's organ, the purpose of which is not understood. These changes are accompanied by a shift in cellular refractive index, allowing optical detection of this activity in real-time. Using this principle, we investigated the origin of spontaneous morphological activity within Kölliker's organ. Apical turns of Wistar rat cochleae (P9-11) were dissected, and the purinergic involvement was studied following acute tissue exposure to a P2 receptor agonist (ATPγS) and antagonist (suramin). ATPγS induced a sustained darkening throughout Kölliker's organ, reversed by suramin. This effect was most pronounced in the region closest to the inner hair cells, which also displayed the highest frequency of intrinsic morphological events. Additionally, suramin alone induced swelling of this region, suggesting a tight regulation of cell volume by ATP-mediated mechanisms. Histological analysis of cochlear tissues demonstrates the most profound volume changes in the border cell region immediately adjacent to the IHCs. Together, these results underline the role of purinergic signalling in initiating morphological events within Kölliker's organ, and suggest a key involvement of border cells surrounding IHCs in regulating this spontaneous activity. Copyright © 2015. Published by Elsevier B.V.

  18. Spontaneous large-scale autolysis in Clostridium acetobutylicum contributes to generation of more spores

    Directory of Open Access Journals (Sweden)

    Zhen eLiu

    2015-09-01

    Full Text Available Autolysis is a widespread phenomenon in bacteria. In batch fermentation of Clostridium acetobutylicum ATCC 824, there is a spontaneous large-scale autolysis phenomenon with significant decrease of cell density immediately after exponential phase. To unravel the role of autolysis, an autolysin-coding gene, CA_C0554, was disrupted by using ClosTron system to obtain the mutant C. acetobutylicum lyc::int(72. The lower final cell density and faster cell density decrease rate of C. acetobutylicum ATCC 824 than those of C. acetobutylicum lyc::int(72 indicates that CA_C0554 was an important but not the sole autolysin-coding gene responding for the large-scale autolysis. Similar glucose utilization and solvents production but obvious lower cell density of C. acetobutylicum ATCC 824 comparing to C. acetobutylicum lyc::int(72 suggests that lysed C. acetobutylicum ATCC 824 cells were metabolic inactive. On the contrary, the spore density of C. acetobutylicum ATCC 824 is 26.1% higher than that of C. acetobutylicum lyc::int(72 in the final culture broth of batch fermentation. We speculated that spontaneous autolysis of metabolic-inactive cells provided nutrients for the sporulating cells. The present study suggests that one important biological role of spontaneous large-scale autolysis in C. acetobutylicum ATCC 824 batch fermentation is contributing to generation of more spores during sporulation.

  19. Spontaneous large-scale autolysis in Clostridium acetobutylicum contributes to generation of more spores.

    Science.gov (United States)

    Liu, Zhen; Qiao, Kai; Tian, Lei; Zhang, Quan; Liu, Zi-Yong; Li, Fu-Li

    2015-01-01

    Autolysis is a widespread phenomenon in bacteria. In batch fermentation of Clostridium acetobutylicum ATCC 824, there is a spontaneous large-scale autolysis phenomenon with significant decrease of cell density immediately after exponential phase. To unravel the role of autolysis, an autolysin-coding gene, CA_C0554, was disrupted by using ClosTron system to obtain the mutant C. acetobutylicum lyc::int(72). The lower final cell density and faster cell density decrease rate of C. acetobutylicum ATCC 824 than those of C. acetobutylicum lyc::int(72) indicates that CA_C0554 was an important but not the sole autolysin-coding gene responding for the large-scale autolysis. Similar glucose utilization and solvents production but obvious lower cell density of C. acetobutylicum ATCC 824 comparing to C. acetobutylicum lyc::int(72) suggests that lysed C. acetobutylicum ATCC 824 cells were metabolic inactive. On the contrary, the spore density of C. acetobutylicum ATCC 824 is 26.1% higher than that of C. acetobutylicum lyc::int(72) in the final culture broth of batch fermentation. We speculated that spontaneous autolysis of metabolic-inactive cells provided nutrients for the sporulating cells. The present study suggests that one important biological role of spontaneous large-scale autolysis in C. acetobutylicum ATCC 824 batch fermentation is contributing to generation of more spores during sporulation.

  20. Iranian Light Source Facility, A third generation light source laboratory

    Directory of Open Access Journals (Sweden)

    J Rahighi

    2015-09-01

    Full Text Available The Iranian Light Source Facility (ILSF project is the first large scale accelerator facility which is currently under planning in Iran. On the basis of the present design, circumference of the 3 GeV storage ring is 528 m. Beam current and natural beam emittance are 400 mA and 0.477 nm.rad, respectively. Some prototype accelerator components such as high power solid state radio frequency amplifiers, low level RF system, thermionic RF gun, H-type dipole and quadruple magnets, magnetic measurement laboratory and highly stable magnet power supplies have been constructed at ILSF R&D laboratory

  1. Spontaneous emission high-gain harmonic generation free-electron laser

    Science.gov (United States)

    Xing, Qingzi; Xu, Xinlu; Feng, Chao; Tang, Chuanxiang

    2011-05-01

    A scheme, spontaneous emission high-gain harmonic generation (SEHG) free-electron laser (FEL), is proposed and analyzed for generating the X-ray FEL. The SEHG scheme works in a similar mechanism as high-gain harmonic generation (HGHG), but without the need for a seed laser. The scheme requires two undulators. The 1st undulator must be sufficiently long so that the energies of electrons are modulated within the bunch, but still away from saturation. A dispersion section is followed to transfer energy modulation into density modulation. The 2nd undulator simply serves as a radiator. A simple, one-dimensional, analytical estimation of SEHG is given to show the process of energy modulation and optimize the system parameters. The three-dimensional FEL simulation code, GENESIS, has been used to simulate, verify, and optimize the SEHG scheme for the soft X-ray free-electron laser (SXFEL) project in China. The simulation results are presented in comparison with the self-amplified spontaneous emission (SASE) and HGHG schemes. At 9 nm radiation wavelength, up to 120 MW of output power can be achieved by the SEHG scheme, with a total length of 47.3 m long undulators. Though the undulator length is comparable with the SASE scheme, the output bandwidth of the SEHG scheme is smaller. Moreover, it is tunable and does not require a seed laser. The SEHG scheme offers an attractive alternative option for the X-ray FEL.

  2. Spontaneous generation of auroral arcs in a three dimensionally coupled magnetosphere-ionosphere system

    International Nuclear Information System (INIS)

    Watanabe, Kunihiko; Sato, Tetsuya.

    1988-01-01

    This paper presents the first full three-dimensional dynamic simulation of auroral arc formation. The magnetospheric and ionospheric dynamics are represented by one-fluid magnetohydrodynamic equations and two-fluid weakly ionized plasma equations, respectively. The feedback coupling between magnetospheric Alfven waves and ionospheric density waves are self-consistently and three-dimensionally solved. Obtained is a spontaneous generation of longitudinally elongated striations of field-aligned currents and ionospheric electron densities, which compare very well with many features of quiet auroral arcs. (author)

  3. Controllable optical bistability and multistability in asymmetric double quantum wells via spontaneously generated coherence

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Yuan; Deng, Li [Department of Applied Physics, East China Jiaotong University, Nanchang, 330013 (China); Chen, Aixi, E-mail: aixichen@ecjtu.jx.cn [Department of Applied Physics, East China Jiaotong University, Nanchang, 330013 (China); Institute for Quantum Computing, University of Waterloo, Ontario N2L 3G1 (Canada)

    2015-02-15

    We investigate the nonlinear optical phenomena of the optical bistability and multistability via spontaneously generated coherence in an asymmetric double quantum well structure coupled by a weak probe field and a controlling field. It is shown that the threshold and hysteresis cycle of the optical bistability can be conveniently controlled only by adjusting the intensity of the SGC or the controlling field. Moreover, switching between optical bistability and multistability can be achieved. These studies may have practical significance for the preparation of optical bistable switching device.

  4. Controllable optical bistability and multistability in asymmetric double quantum wells via spontaneously generated coherence

    International Nuclear Information System (INIS)

    Chen, Yuan; Deng, Li; Chen, Aixi

    2015-01-01

    We investigate the nonlinear optical phenomena of the optical bistability and multistability via spontaneously generated coherence in an asymmetric double quantum well structure coupled by a weak probe field and a controlling field. It is shown that the threshold and hysteresis cycle of the optical bistability can be conveniently controlled only by adjusting the intensity of the SGC or the controlling field. Moreover, switching between optical bistability and multistability can be achieved. These studies may have practical significance for the preparation of optical bistable switching device

  5. Photoelectric charging of dust particles: Effect of spontaneous and light induced field emission of electrons

    International Nuclear Information System (INIS)

    Sodha, M. S.; Dixit, A.

    2009-01-01

    The authors have analyzed the charging of dust particles in a plasma, taking into account the electron/ion currents to the particles, electron/ion generation and recombination, electric field emission, photoelectric emission and photoelectric field emission of electrons under the influence of light irradiation; the irradiance has been assumed to be at a level, which lets the particles retain the negative sign of the charge. Numerical results and discussion conclude the papers.

  6. Synchronization System for Next Generation Light Sources

    Energy Technology Data Exchange (ETDEWEB)

    Zavriyev, Anton [MagiQ Technologies, Inc., Somerville, MA (United States)

    2014-03-27

    An alternative synchronization technique – one that would allow explicit control of the pulse train including its repetition rate and delay is clearly desired. We propose such a scheme. Our method is based on optical interferometry and permits synchronization of the pulse trains generated by two independent mode-locked lasers. As the next generation x-ray sources will be driven by a clock signal derived from a mode-locked optical source, our technique will provide a way to synchronize x-ray probe with the optical pump pulses.

  7. Spontaneous and Widespread Electricity Generation in Natural Deep-Sea Hydrothermal Fields.

    Science.gov (United States)

    Yamamoto, Masahiro; Nakamura, Ryuhei; Kasaya, Takafumi; Kumagai, Hidenori; Suzuki, Katsuhiko; Takai, Ken

    2017-05-15

    Deep-sea hydrothermal vents discharge abundant reductive energy into oxidative seawater. Herein, we demonstrated that in situ measurements of redox potentials on the surfaces of active hydrothermal mineral deposits were more negative than the surrounding seawater potential, driving electrical current generation. We also demonstrated that negative potentials in the surface of minerals were widespread in the hydrothermal fields, regardless of the proximity to hydrothermal fluid discharges. Lab experiments verified that the negative potential of the mineral surface was induced by a distant electron transfer from the hydrothermal fluid through the metallic and catalytic properties of minerals. These results indicate that electric current is spontaneously and widely generated in natural mineral deposits in deep-sea hydrothermal fields. Our discovery provides important insights into the microbial communities that are supported by extracellular electron transfer and the prebiotic chemical and metabolic evolution of the ocean hydrothermal systems. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Broadband photon pair generation in green fluorescent proteins through spontaneous four-wave mixing

    Science.gov (United States)

    Shi, Siyuan; Thomas, Abu; Corzo, Neil V.; Kumar, Prem; Huang, Yuping; Lee, Kim Fook

    2016-04-01

    Recent studies in quantum biology suggest that quantum mechanics help us to explore quantum processes in biological system. Here, we demonstrate generation of photon pairs through spontaneous four-wave mixing process in naturally occurring fluorescent proteins. We develop a general empirical method for analyzing the relative strength of nonlinear optical interaction processes in five different organic fluorophores. Our results indicate that the generation of photon pairs in green fluorescent proteins is subject to less background noises than in other fluorophores, leading to a coincidence-to-accidental ratio ~145. As such proteins can be genetically engineered and fused to many biological cells, our experiment enables a new platform for quantum information processing in a biological environment such as biomimetic quantum networks and quantum sensors.

  9. A developmentally plastic adult mouse kidney cell line spontaneously generates multiple adult kidney structures

    International Nuclear Information System (INIS)

    Webb, Carol F.; Ratliff, Michelle L.; Powell, Rebecca; Wirsig-Wiechmann, Celeste R.; Lakiza, Olga; Obara, Tomoko

    2015-01-01

    Despite exciting new possibilities for regenerative therapy posed by the ability to induce pluripotent stem cells, recapitulation of three-dimensional kidneys for repair or replacement has not been possible. ARID3a-deficient mouse tissues generated multipotent, developmentally plastic cells. Therefore, we assessed the adult mouse ARID3a−/− kidney cell line, KKPS5, which expresses renal progenitor surface markers as an alternative cell source for modeling kidney development. Remarkably, these cells spontaneously developed into multicellular nephron-like structures in vitro, and engrafted into immunocompromised medaka mesonephros, where they formed mouse nephron structures. These data implicate KKPS5 cells as a new model system for studying kidney development. - Highlights: • An ARID3a-deficient mouse kidney cell line expresses multiple progenitor markers. • This cell line spontaneously forms multiple nephron-like structures in vitro. • This cell line formed mouse kidney structures in immunocompromised medaka fish kidneys. • Our data identify a novel model system for studying kidney development

  10. A developmentally plastic adult mouse kidney cell line spontaneously generates multiple adult kidney structures

    Energy Technology Data Exchange (ETDEWEB)

    Webb, Carol F., E-mail: carol-webb@omrf.org [Department of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK (United States); Immunobiology and Cancer Research, Oklahoma Medical Research Foundation, Oklahoma City, OK (United States); Department of Microbiology and Immunology, University of Oklahoma Health Sciences Center, Oklahoma City, OK (United States); Ratliff, Michelle L., E-mail: michelle-ratliff@omrf.org [Immunobiology and Cancer Research, Oklahoma Medical Research Foundation, Oklahoma City, OK (United States); Powell, Rebecca, E-mail: rebeccapowell@gmail.com [Department of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK (United States); Wirsig-Wiechmann, Celeste R., E-mail: celeste-wirsig@ouhsc.edu [Department of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK (United States); Lakiza, Olga, E-mail: olga-lakiza@ouhsc.edu [Department of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK (United States); Obara, Tomoko, E-mail: tomoko-obara@ouhsc.edu [Department of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK (United States)

    2015-08-07

    Despite exciting new possibilities for regenerative therapy posed by the ability to induce pluripotent stem cells, recapitulation of three-dimensional kidneys for repair or replacement has not been possible. ARID3a-deficient mouse tissues generated multipotent, developmentally plastic cells. Therefore, we assessed the adult mouse ARID3a−/− kidney cell line, KKPS5, which expresses renal progenitor surface markers as an alternative cell source for modeling kidney development. Remarkably, these cells spontaneously developed into multicellular nephron-like structures in vitro, and engrafted into immunocompromised medaka mesonephros, where they formed mouse nephron structures. These data implicate KKPS5 cells as a new model system for studying kidney development. - Highlights: • An ARID3a-deficient mouse kidney cell line expresses multiple progenitor markers. • This cell line spontaneously forms multiple nephron-like structures in vitro. • This cell line formed mouse kidney structures in immunocompromised medaka fish kidneys. • Our data identify a novel model system for studying kidney development.

  11. Heavy-heavy and heavy-light quarks interactions generated by QCD vacuum

    Directory of Open Access Journals (Sweden)

    Musakhanov Mirzayusuf

    2017-01-01

    Full Text Available The QCD vacuum is populated by instantons that correspond to the tunneling processes in the vacuum. This mechanism creates the strong vacuum gluon fields. As result, the QCD vacuum instantons induce very strong interactions between light quarks, initially almost massless. Such a strong interactions bring a large dynamical mass M of the light quarks and bound them to produce almost massless pions in accordance with the spontaneous breaking of the chiral symmetry (SBCS. On the other hand, the QCD vacuum instantons also interact with heavy quarks and responsible for the generation of the heavy-heavy and heavy-light quarks interactions, with a traces of the SBCS. If we take the average instanton size ρ¯=0.33$\\bar \\rho = 0.33$ fm, and the average inter-instanton distance R¯=1$\\bar R = 1$ fm we obtain the dynamical light quark mass to be M = 365 MeV and the instanton media contribution to the heavy quark mass ΔM=70 MeV. These factors define the coupling between heavy-light and heavy-heavy quarks induced by the QCD vacuum instantons. We consider first the instanton effects on the heavy-heavy quarks potential, including its spin-dependent part. We also discuss those effects on the masses of the charmonia and their hyperfine mass splittings. At the second part we discuss the interaction between a heavy and light quarks generated by instantons and it’s effects.

  12. High-dimensional atom localization via spontaneously generated coherence in a microwave-driven atomic system.

    Science.gov (United States)

    Wang, Zhiping; Chen, Jinyu; Yu, Benli

    2017-02-20

    We investigate the two-dimensional (2D) and three-dimensional (3D) atom localization behaviors via spontaneously generated coherence in a microwave-driven four-level atomic system. Owing to the space-dependent atom-field interaction, it is found that the detecting probability and precision of 2D and 3D atom localization behaviors can be significantly improved via adjusting the system parameters, the phase, amplitude, and initial population distribution. Interestingly, the atom can be localized in volumes that are substantially smaller than a cubic optical wavelength. Our scheme opens a promising way to achieve high-precision and high-efficiency atom localization, which provides some potential applications in high-dimensional atom nanolithography.

  13. The 4th Generation Light Source at Jefferson Lab

    Energy Technology Data Exchange (ETDEWEB)

    Stephen Benson; George Biallas; James Boyce; Donald Bullard; James Coleman; David Douglas; H. Dylla; Richard Evans; Pavel Evtushenko; Albert Grippo; Christopher Gould; Joseph Gubeli; David Hardy; Carlos Hernandez-Garcia; Kevin Jordan; John Klopf; Steven Moore; George Neil; Thomas Powers; Joseph Preble; Daniel Sexton; Michelle D. Shinn; Christopher Tennant; Richard Walker; Shukui Zhang; Gwyn Williams

    2007-04-25

    A number of "Grand Challenges" in Science have recently been identified in reports from The National Academy of Sciences, and the U.S. Dept. of Energy, Basic Energy Sciences. Many of these require a new generation of linac-based light source to study dynamical and non-linear phenomena in nanoscale samples. In this paper we present a summary of the properties of such light sources, comparing them with existing sources, and then describing in more detail a specific source at Jefferson Lab. Importantly, the JLab light source has developed some novel technology which is a critical enabler for other new light sources.

  14. The 4th Generation Light Source at Jefferson Lab

    International Nuclear Information System (INIS)

    Stephen Benson; George Biallas; James Boyce; Donald Bullard; James Coleman; David Douglas; H. Dylla; Richard Evans; Pavel Evtushenko; Albert Grippo; Christopher Gould; Joseph Gubeli; David Hardy; Carlos Hernandez-Garcia; Kevin Jordan; John Klopf; Steven Moore; George Neil; Thomas Powers; Joseph Preble; Daniel Sexton; Michelle Shinn; Christopher Tennant; Richard Walker; Shukui Zhang; Gwyn Williams

    2007-01-01

    A number of 'Grand Challenges' in Science have recently been identified in reports from The National Academy of Sciences, and the U.S. Dept. of Energy, Basic Energy Sciences. Many of these require a new generation of linac-based light source to study dynamical and non-linear phenomena in nanoscale samples. In this paper we present a summary of the properties of such light sources, comparing them with existing sources, and then describing in more detail a specific source at Jefferson Lab. Importantly, the JLab light source has developed some novel technology which is a critical enabler for other new light sources

  15. Light-front quantized field theory (an introduction): spontaneous symmetry breaking. Phase transition in φ4 theory

    International Nuclear Information System (INIS)

    Srivastava, Prem P.

    1994-01-01

    The Dirac procedure is used to construct the Hamiltonian formulation of the scalar field theory on the light-front. The theory is quantized and the mechanism of the spontaneous symmetry breaking in the front form and the instant form dynamics are compared. The phase transition in (φ 4 )2 theory is also discussed and found to be of the second order. (author). 36 refs

  16. Spontaneous emission of a cesium atom near a nanofiber: Efficient coupling of light to guided modes

    International Nuclear Information System (INIS)

    Le Kien, Fam; Hakuta, K.; Dutta Gupta, S.; Balykin, V.I.

    2005-01-01

    We study the spontaneous emission of a cesium atom in the vicinity of a subwavelength-diameter fiber. We show that the confinement of the guided modes and the degeneracy of the excited and ground states substantially affect the spontaneous emission process. We demonstrate that different magnetic sublevels have different decay rates. When the fiber radius is about 200 nm, a significant fraction (up to 28%) of spontaneous emission by the atom can be channeled into guided modes. Our results may find applications for developing nanoprobes for atoms and efficient couplers for subwavelength-diameter fibers

  17. Generation and characterization of a spontaneously immortalized endothelial cell line from mice microcirculation.

    Science.gov (United States)

    Loiola, Rodrigo A; Torres, Tathiany C; Aburaya, Carla M; Landgraf, Maristella A; Landgraf, Richardt G; Bosco Pesquero, João; Fernandes, Liliam

    2013-05-01

    Endothelial cells from microvasculature are directly involved in a large number of vascular diseases; however, culture of these cells is problematic, since most methodologies employ proteolytic enzymes or mechanical techniques, leading to cell damage and contamination of endothelial cultures with other cellular types. Besides, primary cultured cells have a short life span in vitro and undergo replicative senescence after 3-4 passages, limiting long-term studies. In the present work we report the generation of a spontaneously immortalized endothelial culture obtained from mice pulmonary capillaries. Firstly, primary (third passage) and immortalized (100th) cultures were established. Further, monoclonal populations were obtained by serial dilutions from immortalized cultures. Cells were analyzed according to: (1) morphological appearance, (2) expression of specific endothelial markers by fluorescent staining [von Willebrand Factor (vWF), endothelial nitric oxide synthase (eNOS), angiotensin converting enzyme (ACE) and Ulex europaeus (UEA-1)] and by flow cytometry (endoglin, VE-cadherin and VCAM-1), and (3) release of nitric oxide (NO), assessed by the specific fluorescent dye DAF-2 DA, and prostacyclin (PGI2), quantified by enzyme immune assay. In both cultures cells grew in monolayers and presented cobblestone appearance at confluence. Positive staining for vWF, eNOS, ACE and UEA-1 was detected in cloned as well as in early-passage cultured cells. Similarly, cultures presented equal expressions of endoglin, VE-cadherin and VCAM-1. Values of NO and PGI2 levels did not differ between cultures. From these results we confirm that the described spontaneously immortalized endothelial cell line is capable of unlimited growth and retains typical morphological and functional properties exhibited by primary cultured cells. Therefore, the endothelial cell line described in the present study can become a suitable tool in the field of endothelium research and can be useful for

  18. Effects of harman and norharman on spontaneous and ultraviolet light-induced mutagenesis in cultured Chinese hamster cells

    International Nuclear Information System (INIS)

    Chang, C.C.; Castellazzi, M.; Glover, T.W.; Trosko, J.E.

    1978-01-01

    Nontoxic concentrations of harman and norharman were tested in cultured Chinese hamster cells for their effects on DNA repair and mutagenesis. The following effects of harman were observed: (a) the survival of ultraviolet light- or x-ray-damaged cells was reduced; (b) the ultraviolet light-induced unscheduled DNA synthesis was slightly inhibited; and (c) the frequency of spontaneous or ultraviolet light-induced ouabain-resistant (ouar) or 6-thioguanine-resistant (6-TGr) mutations was reduced. Furthermore, the effect of harman on survival and mutagenesis was greater than that of norharman and was detected primarily in treatments in which cells were exposed to harman immediately following ultraviolet light irradiation. Our data clearly indicate that harman decreases the capacity to repair DNA damage and fix mutations in Chinese hamster cells, possibly because of the intercalation properties of this compound

  19. The POLIS interferometer for ponderomotive squeezed light generation

    Energy Technology Data Exchange (ETDEWEB)

    Calloni, Enrico [Dipartimento di Fisica, Università degli Studi di Napoli “Federico II”, Napoli (Italy); INFN, Sezione di Napoli (Italy); Conte, Andrea [Dipartimento di Fisica, Università di Roma “Sapienza”, Roma (Italy); INFN, Sezione di Roma1 (Italy); De Laurentis, Martina, E-mail: martina.delaurentis@na.infn.it [Dipartimento di Fisica, Università degli Studi di Napoli “Federico II”, Napoli (Italy); INFN, Sezione di Napoli (Italy); Naticchioni, Luca [Dipartimento di Fisica, Università di Roma “Sapienza”, Roma (Italy); INFN, Sezione di Roma1 (Italy); Puppo, Paola [INFN, Sezione di Roma1 (Italy); Ricci, Fulvio [Dipartimento di Fisica, Università di Roma “Sapienza”, Roma (Italy); INFN, Sezione di Roma1 (Italy)

    2016-07-11

    POLIS (POnderomotive LIght Squeezer) is a suspended interferometer, presently under construction, devoted to the generation of ponderomotive squeezed light and to the study of the interaction of non classical quantum states of light and macroscopic objects. The interferometer is a Michelson whose half-meter long arms are constituted by high-finesse cavities, suspended to a seismic isolation chain similar to the Virgo SuperAttenuator. The mass of the suspended cavity mirrors are chosen to be tens of grams: this value is sufficiently high to permit the use of the well-tested Virgo suspension techniques but also sufficiently small to generate the coupling among the two phase quadratures with a limited amount of light in the cavity, of the order of few tens of kW. In this short paper the main features of the interferometer are shown, together with the expected sensitivity and squeezing factor.

  20. Light-Patterned Current Generation in a Droplet Bilayer Array

    Science.gov (United States)

    Restrepo Schild, Vanessa; Booth, Michael J.; Box, Stuart J.; Olof, Sam N.; Mahendran, Kozhinjampara R.; Bayley, Hagan

    2017-04-01

    We have created a 4 × 4 droplet bilayer array comprising light-activatable aqueous droplet bio-pixels. Aqueous droplets containing bacteriorhodopsin (bR), a light-driven proton pump, were arranged on a common hydrogel surface in lipid-containing oil. A separate lipid bilayer formed at the interface between each droplet and the hydrogel; each bilayer then incorporated bR. Electrodes in each droplet simultaneously measured the light-driven proton-pumping activities of each bio-pixel. The 4 × 4 array derived by this bottom-up synthetic biology approach can detect grey-scale images and patterns of light moving across the device, which are transduced as electrical current generated in each bio-pixel. We propose that synthetic biological light-activatable arrays, produced with soft materials, might be interfaced with living tissues to stimulate neuronal pathways.

  1. Permanent magnet based dipole magnets for next generation light sources

    Directory of Open Access Journals (Sweden)

    Takahiro Watanabe

    2017-07-01

    Full Text Available We have developed permanent magnet based dipole magnets for the next generation light sources. Permanent magnets are advantageous over electromagnets in that they consume less power, are physically more compact, and there is a less risk of power supply failure. However, experience with electromagnets and permanent magnets in the field of accelerators shows that there are still challenges to replacing main magnets of accelerators for light sources with permanent magnets. These include the adjustability of the magnetic field, the temperature dependence of permanent magnets, and the issue of demagnetization. In this paper, we present a design for magnets for future light sources, supported by experimental and numerical results.

  2. Comparison of the heat generation of light curing units.

    Science.gov (United States)

    Bagis, Bora; Bagis, Yildirim; Ertas, Ertan; Ustaomer, Seda

    2008-02-01

    The aim of this study was to evaluate the heat generation of three different types of light curing units. Temperature increases were recorded from a distance of 1 mm from a thermocouple to the tip of three different types of light curing units including one quartz-tungsten halogen (QTH), one plasma arc (PAC), and one light emitting diode (LED) unit. An experimental model was designed to fix the 1 mm distance between the tip of the light curing units and the thermocouple wire. Temperature changes were recorded in 10 second intervals up to 40 seconds. (10, 20, 30, and 40 seconds). Temperature measurements were repeated three times for every light curing unit after a one hour standby period. Statistical analysis of the results was performed using the analysis of variance (ANOVA) and the Bonferroni Test. The highest temperature rises (54.4+/-1.65 degrees C) occurred during activation of a PAC light curing unit for every test period (p<.05). The least temperature increase (11.8+/-1.3 degrees C) occurred with a LED curing unit for each tested period except for the measurement of the temperature rise using the QTH curing unit at the tenth second interval (p<.05). These results indicate the choice of light activation unit and curing time is important when polymerizing light activated resin based restorations to avoid any thermal damage to the pulp.

  3. Compact quantum random number generator based on superluminescent light-emitting diodes

    Science.gov (United States)

    Wei, Shihai; Yang, Jie; Fan, Fan; Huang, Wei; Li, Dashuang; Xu, Bingjie

    2017-12-01

    By measuring the amplified spontaneous emission (ASE) noise of the superluminescent light emitting diodes, we propose and realize a quantum random number generator (QRNG) featured with practicability. In the QRNG, after the detection and amplification of the ASE noise, the data acquisition and randomness extraction which is integrated in a field programmable gate array (FPGA) are both implemented in real-time, and the final random bit sequences are delivered to a host computer with a real-time generation rate of 1.2 Gbps. Further, to achieve compactness, all the components of the QRNG are integrated on three independent printed circuit boards with a compact design, and the QRNG is packed in a small enclosure sized 140 mm × 120 mm × 25 mm. The final random bit sequences can pass all the NIST-STS and DIEHARD tests.

  4. Generation of multicolor spatial solitons with pulsed light

    OpenAIRE

    Carrasco Rodríguez, Sílvia; Pérez Torres, Juan; Artigas García, David; Torner Sabata, Lluís

    2001-01-01

    The impact of temporal effects to the generation of multiple wave quadratic spatial solitons with pulsed light is shown. We examine soliton formation under conditions of second-harmonic generation but our conclusions are relevant to soliton formation in all parametric processes. It is shown how group-velocity mismatch between the multiple interacting signals prevents spatial soliton formation with too short pulses. Illustrative examples of the minimum pulse width allowed for soliton generatio...

  5. Spontaneous angular momentum generation of two-dimensional fluid flow in an elliptic geometry

    NARCIS (Netherlands)

    Keetels, G.H.; Clercx, H.J.H.; van Heijst, G.J.F.

    2008-01-01

    Spontaneous spin-up, i.e., the significant increase of the total angular momentum of a flow that initially has no net angular momentum, is very characteristic for decaying two-dimensional turbulence in square domains bounded by rigid no-slip walls. In contrast, spontaneous spin-up is virtually

  6. Sub-Poissonian-light generation by postselection from twin beams

    Czech Academy of Sciences Publication Activity Database

    Peřina Jr., J.; Haderka, O.; Michálek, Václav

    2013-01-01

    Roč. 21, č. 16 (2013), 19387-19394 ISSN 1094-4087 R&D Projects: GA ČR GAP205/12/0382 Institutional support: RVO:68378271 Keywords : twin beams * Sub-Poissonian-light generation Subject RIV: BH - Optics, Masers, Lasers Impact factor: 3.525, year: 2013

  7. Quantitative analysis of directional spontaneous emission spectra from light sources in photonic crystals

    NARCIS (Netherlands)

    Nikolaev, I.; Lodahl, P.; Vos, Willem L.

    2005-01-01

    We have performed angle-resolved measurements of spontaneous-emission spectra from laser dyes and quantum dots in opal and inverse opal photonic crystals. Pronounced directional dependencies of the emission spectra are observed: angular ranges of strongly reduced emission adjoin with angular ranges

  8. Real-time Image Generation for Compressive Light Field Displays

    International Nuclear Information System (INIS)

    Wetzstein, G; Lanman, D; Hirsch, M; Raskar, R

    2013-01-01

    With the invention of integral imaging and parallax barriers in the beginning of the 20th century, glasses-free 3D displays have become feasible. Only today—more than a century later—glasses-free 3D displays are finally emerging in the consumer market. The technologies being employed in current-generation devices, however, are fundamentally the same as what was invented 100 years ago. With rapid advances in optical fabrication, digital processing power, and computational perception, a new generation of display technology is emerging: compressive displays exploring the co-design of optical elements and computational processing while taking particular characteristics of the human visual system into account. In this paper, we discuss real-time implementation strategies for emerging compressive light field displays. We consider displays composed of multiple stacked layers of light-attenuating or polarization-rotating layers, such as LCDs. The involved image generation requires iterative tomographic image synthesis. We demonstrate that, for the case of light field display, computed tomographic light field synthesis maps well to operations included in the standard graphics pipeline, facilitating efficient GPU-based implementations with real-time framerates.

  9. Brain-machine interfaces in space: Using spontaneous rather than intentionally generated brain signals

    NARCIS (Netherlands)

    Coffey, E.B.J.; Brouwer, A.M.; Wilschut, E.S.; Erp, J.B.F. van

    2010-01-01

    De auteurs bespreken de beperkingen en mogelijkheden van gesuggereerde BMI toepassingen in een ruimtevaart en breken een lans voor BMIs die zijn gebaseerd op spontane in plaats van op doelbewuste hersensignalen

  10. Diamond Light Source - A Next Generation SR Facility

    International Nuclear Information System (INIS)

    Materlik, G.

    2004-01-01

    After the very successful start and the by now almost 10 years operation of the 3rd generation x-ray sources ESRF, APS and Spring-8 smaller storage rings are being planned and constructed with properties emphasising applications with photon energies around the 10 keV spectral region. In the UK the Government and the medical foundation Wellcome Trust have decided to build the Diamond Light Source Facility in the South of Oxfordshire right next to the Rutherford Appleton Laboratory. The joint venture company Diamond Light Source Limited has been created to plan, construct, and operate this facility. (author)

  11. Spontaneous generation of bending waves in isolated Milky Way-like discs

    Science.gov (United States)

    Chequers, Matthew H.; Widrow, Lawrence M.

    2017-12-01

    We study the spontaneous generation and evolution of bending waves in N-body simulations of two isolated Milky Way-like galaxy models. The models differ by their disc-to-halo mass ratios, and hence by their susceptibility to the formation of a bar and spiral structure. Seeded from shot noise in the particle distribution, bending waves rapidly form in both models and persist for many billions of years. Waves at intermediate radii manifest as corrugated structures in vertical position and velocity that are tightly wound, morphologically leading and dominated by the m = 1 azimuthal Fourier component. A spectral analysis of the waves suggests they are a superposition of modes from two continuous branches in the Galactocentric radius-rotational frequency plane. The lower frequency branch is dominant and is responsible for the corrugated, leading and warped structure. Over time, power in this branch migrates outward, lending credence to an inside-out formation scenario for the warp. Our power spectra qualitatively agree with results from linear perturbation theory and a WKB analysis, both of which include self-gravity. Thus, we conclude that the waves in our simulations are self-gravitating and not purely kinematic. These waves are reminiscent of the wave-like pattern recently found in Galactic star counts from the Sloan Digital Sky Survey and smoothly transition to a warp near the disc's edge. Velocity measurements from Gaia data will be instrumental in testing the true wave nature of the corrugations. We also compile a list of 'minimum requirements' needed to observe bending waves in external galaxies.

  12. Controlled and spontaneous magnetic field generation in a gun-driven spheromak

    International Nuclear Information System (INIS)

    Woodruff, S.; Cohen, B.I.; Hooper, E.B.; Mclean, H.S.; Stallard, B.W.; Hill, D.N.; Holcomb, C.T.; Romero-Talamas, C.; Wood, R.D.; Cone, G.; Sovinec, C.R.

    2005-01-01

    In the Sustained Spheromak Physics Experiment, SSPX [E. B. Hooper, D. Pearlstein, and D. D. Ryutov, Nucl. Fusion 39, 863 (1999)], progress has been made in understanding the mechanisms that generate fields by helicity injection. SSPX injects helicity (linked magnetic flux) from 1 m diameter magnetized coaxial electrodes into a flux-conserving confinement region. Control of magnetic fluctuations (δB/B∼1% on the midplane edge) yields T e profiles peaked at >200 eV. Trends indicate a limiting beta (β e ∼4%-6%), and so we have been motivated to increase T e by operating with stronger magnetic field. Two new operating modes are observed to increase the magnetic field: (A) Operation with constant current and spontaneous gun voltage fluctuations. In this case, the gun is operated continuously at the threshold for ejection of plasma from the gun: stored magnetic energy of the spheromak increases gradually with δB/B∼2% and large voltage fluctuations (δV∼1 kV), giving a 50% increase in current amplification, I tor /I gun . (B) Operation with controlled current pulses. In this case, spheromak magnetic energy increases in a stepwise fashion by pulsing the gun, giving the highest magnetic fields observed for SSPX (∼0.7 T along the geometric axis). By increasing the time between pulses, a quasisteady sustainment is produced (with periodic good confinement), comparing well with resistive magnetohydrodynamic simulations. In each case, the processes that transport the helicity into the spheromak are inductive and exhibit a scaling of field with current that exceeds those previously obtained. We use our newly found scaling to suggest how to achieve higher temperatures with a series of pulses

  13. Controlled and Spontaneous Magnetic Field Generation in a Gun-Driven Spheromak

    International Nuclear Information System (INIS)

    Woodruff, S; Cohen, B I; Hooper, E B; McLean, H S; Stallard, B W; Hill, D N; Holcomb, C T; Romero-Talamas, C; Wood, R D; Cone, G; Sovinec, C R

    2005-04-01

    In the Sustained Spheromak Physics Experiment, SSPX, progress has been made in understanding the mechanisms that generate fields by helicity injection. SSPX injects helicity (linked magnetic flux) from 1-m diameter magnetized coaxial electrodes into a flux-conserving confinement region. Control of magnetic fluctuations ((delta)B/B∼1% on the midplane edge) yields T e profiles peaked at > 200eV. Trends indicate a limiting beta (β e ∼ 4-6%), and so we have been motivated to increase T e by operating with stronger magnetic field. Two new operating modes are observed to increase the magnetic field: (A) Operation with constant current and spontaneous gun voltage fluctuations. In this case, the gun is operated continuously at the threshold for ejection of plasma from the gun: stored magnetic energy of the spheromak increases gradually with (delta)B/B ∼2% and large voltage fluctuations ((delta)V ∼ 1kV), giving a 50% increase in current amplification, I tor /I gun . (B) Operation with controlled current pulses. In this case, spheromak magnetic energy increases in a stepwise fashion by pulsing the gun, giving the highest magnetic fields observed for SSPX (∼0.7T along the geometric axis). By increasing the time between pulses, a quasi-steady sustainment is produced (with periodic good confinement), comparing well with resistive MHD simulations. In each case, the processes that transport the helicity into the spheromak are inductive and exhibit a scaling of field with current that exceeds those previously obtained. We use our newly found scaling to suggest how to achieve higher temperatures with a series of pulses

  14. Dynamic generation of light states with discrete symmetries

    Science.gov (United States)

    Cordero, S.; Nahmad-Achar, E.; Castaños, O.; López-Peña, R.

    2018-01-01

    A dynamic procedure is established within the generalized Tavis-Cummings model to generate light states with discrete point symmetries, given by the cyclic group Cn. We consider arbitrary dipolar coupling strengths of the atoms with a one-mode electromagnetic field in a cavity. The method uses mainly the matter-field entanglement properties of the system, which can be extended to any number of three-level atoms. An initial state constituted by the superposition of two states with definite total excitation numbers, |ψ〉 M1,and |ψ〉 M 2, is considered. It can be generated by the proper selection of the time of flight of an atom passing through the cavity. We demonstrate that the resulting Husimi function of the light is invariant under cyclic point transformations of order n =| M1-M2| .

  15. Dynamic light scattering on bioconjugated laser generated gold nanoparticles.

    Directory of Open Access Journals (Sweden)

    Massimo Zimbone

    Full Text Available Gold nanoparticles (AuNPs conjugated to DNA are widely used for biomedical targeting and sensing applications. DNA functionalization is easily reached on laser generated gold nanoparticles because of their unique surface chemistry, not reproducible by other methods. In this context, we present an extensive investigation concerning the attachment of DNA to the surface of laser generated nanoparticles using Dynamic Light Scattering and UV-Vis spectroscopy. The DNA conjugation is highlighted by the increase of the hydrodynamic radius and by the UV-Vis spectra behavior. Our investigation indicates that Dynamic Light Scattering is a suitable analytical tool to evidence, directly and qualitatively, the binding between a DNA molecule and a gold nanoparticle, therefore it is ideal to monitor changes in the conjugation process when experimental conditions are varied.

  16. Efficient lighting in a coal fired generating station

    Energy Technology Data Exchange (ETDEWEB)

    Panchal, B. [Ontario Power Generation, Toronto, ON (Canada)

    2001-02-01

    Upgrading the lighting in one of Ontario Power Generation's (formerly Ontario Hydro) coal-fired generating plants by replacing the open strip Very High Output (VHO) and F40 fixtures with metal halide fixtures (30-40 watt and 10-25 watt fixtures, respectively) is discussed. The wholesale replacement was preceded by a one year long trial in which 81 VHO and 79 F40 were replaced with 40 metal halide fixtures. The subsequent choice of metal halide for the entire plant was based on the results of this pilot project. Results showed a four-fold increase in light levels, a significant reduction in the number and types of lamps and ballasts used, a 60 per cent reduction in energy consumption and a 50 per cent reduction in maintenance costs. 2 photos.

  17. Prospects for Next-Generation Storage Ring Light Sources

    Science.gov (United States)

    Borland, Michael

    2015-04-01

    Storage ring light sources are among the most productive large-scale scientific user facilities in existence, owing to a combination of broad tunability, mature technology, high capacity, remarkable reliability, and high performance. The most commonly-used performance measure is the photon beam brightness, which is proportional to the flux per unit volume in six-dimensional phase space. The brightness is generally maximized by minimizing the transverse phase space area, or emittance, of the electron beam that generates the photons. Since the 1990's, most storage ring light sources have used a variant of the Chasman-Green, or double-bend-achromat (DBA), lattice, which produces transverse emittances of several nanometers. Presently, several light sources are under construction based on more challenging multi-bend-achromat (MBA) concepts, which promise an order of magnitude reduction in the emittance. Somewhat larger reductions are contemplated for upgrades of the largest facilities. This talk briefly surveys the relevant concepts in light source design, then explains both the mechanism and challenge of achieving next-generation emittances. Other factors, such as improved radiation-emitting devices, are also described. Work supported by the U.S. Department of Energy, Office of Science, under Contract No. DE-AC02-06CH11357.

  18. Spontaneous class switch recombination in B cell lymphopoiesis generates aberrant switch junctions and is increased after VDJ rearrangement.

    Science.gov (United States)

    Edry, Efrat; Koralov, Sergei B; Rajewsky, Klaus; Melamed, Doron

    2007-11-15

    Mature B cells replace the mu constant region of the H chain with a downstream isotype in a process of class switch recombination (CSR). Studies suggest that CSR induction is limited to activated mature B cells in the periphery. Recently, we have shown that CSR spontaneously occur in B lymphopoiesis. However, the mechanism and regulation of it have not been defined. In this study, we show that spontaneous CSR occurs at all stages of B cell development and generates aberrant joining of the switch junctions as revealed by: 1) increased load of somatic mutations around the CSR break points, 2) reduced sequence overlaps at the junctions, and 3) excessive switch region deletion. In addition, we found that incidence of spontaneous CSR is increased in cells carrying VDJ rearrangements. Our results reveal major differences between spontaneous CSR in developing B cells and CSR induced in mature B cells upon activation. These differences can be explained by deregulated expression or function of activation-induced cytidine deaminase early in B cell development.

  19. Observation of magnetic flux generated spontaneously during a rapid quench of superconducting films

    International Nuclear Information System (INIS)

    Maniv, A.; Polturak, E.; Koren, G.

    2003-01-01

    We report observations of spontaneous formation of magnetic flux lines during a rapid quench of YBa 2 Cu 3 O 7-δ films through T c . This effect is predicted according to the Kibble-Zurek mechanism of creation of topological defects of the order parameter during a symmetry-breaking phase transition. Our previous experiment, at a quench rate of 20 K/s, gave null results. In the present experiment, the quench rate was increased to >10 8 K/s. The amount of spontaneous flux increases weakly with the cooling rate

  20. Spontaneous mutations in the flhD operon generate motility heterogeneity in Escherichia coli biofilm.

    Science.gov (United States)

    Horne, Shelley M; Sayler, Joseph; Scarberry, Nicholas; Schroeder, Meredith; Lynnes, Ty; Prüß, Birgit M

    2016-11-08

    Heterogeneity and niche adaptation in bacterial biofilm involve changes to the genetic makeup of the bacteria and gene expression control. We hypothesized that i) spontaneous mutations in the flhD operon can either increase or decrease motility and that ii) the resulting motility heterogeneity in the biofilm might lead to a long-term increase in biofilm biomass. We allowed the highly motile E. coli K-12 strain MC1000 to form seven- and fourteen-day old biofilm, from which we recovered reduced motility isolates at a substantially greater frequency (5.4 %) than from a similar experiment with planktonic bacteria (0.1 %). Biofilms formed exclusively by MC1000 degraded after 2 weeks. In contrast, biofilms initiated with a 1:1 ratio of MC1000 and its isogenic flhD::kn mutant remained intact at 4 weeks and the two strains remained in equilibrium for at least two weeks. These data imply that an 'optimal' biofilm may contain a mixture of motile and non-motile bacteria. Twenty-eight of the non-motile MC1000 isolates contained an IS1 element in proximity to the translational start of FlhD or within the open reading frames for FlhD or FlhC. Two isolates had an IS2 and one isolate had an IS5 in the open reading frame for FlhD. An additional three isolates contained deletions that included the RNA polymerase binding site, five isolates contained point mutations and small deletions in the open reading frame for FlhC. The locations of all these mutations are consistent with the lack of motility and further downstream within the flhD operon than previously published IS elements that increased motility. We believe that the location of the mutation within the flhD operon determines whether the effect on motility is positive or negative. To test the second part of our hypothesis where motility heterogeneity in a biofilm may lead to a long-term increase in biofilm biomass, we quantified biofilm biomass by MC1000, MC1000 flhD::kn, and mixtures of the two strains at ratios of 1:1, 10

  1. Volatile metabolite profiling reveals the changes in the volatile compounds of new spontaneously generated loquat cultivars.

    Science.gov (United States)

    Besada, C; Sanchez, G; Gil, R; Granell, A; Salvador, A

    2017-10-01

    In recent years, the advantageous traits of three new loquat cultivars have drawn the attention of breeders and growers. All three have spontaneously arisen from the 'Algerie' cultivar: the new 'Xirlero' cultivar is a bud mutant of 'Algerie', while 'Amadeo' and 'Raúl' arose as chance seedlings. Following a non-targeted approach based on HS-SPME-GC-MS, the volatile compounds profile of the fruits from the new cultivars were obtained and compared to the original 'Algerie' cultivar. Carboxylic acids clearly dominated the volatile profile of all the loquat cultivars, but esters, aldehydes, ketones and alcohols were also predominant compounds. Interestingly when the bud mutant event did not lead to marked changes in the volatile compounds complement, pronounced changes in the volatile composition of chance seedling-generated cultivars 'Amadeo' and 'Raúl' were observed. 'Amadeo' fruits showed lower levels of 2-methyl butanoic acid and much higher levels of methylhexanoate, methylbutanoate and 2-hydroxy-5-methylacetophenone. The 'Raúl' cultivar also had a distinctive volatile profile characterised by high levels of C6-aldehydes, (E)-2-hexanal, 2-hexenal, (Z)-3-hexenal and hexanal, and several carotenoid-derived volatiles; e.g. 2-pentene-1,4-dione 1-(1,2,2-trimethylcyclopentyl), (S)-dihydroactinidiolide, isodurene, cis-geranyl acetone, β-damascenone, β-ionone, α-ionone and 3,4-dehydro-β-ionone. These changes in volatiles were associated with a more intense flavour in cultivars 'Amadeo' and 'Raúl', according to the sensory evaluation of the flavour intensity carried out by a semi-trained panel. A metabolomic correlation network analysis provided insights as to how volatiles were regulated, and revealed that the compounds modified in 'Amadeo' were uncoupled from the rest of the volatilome, while the volatiles modified in 'Raul' changed according to specific groups. To conclude, this work provides a holistic view of how the loquat volatilome was affected, and this

  2. Power generation versus fuel production in light water hybrid reactors

    International Nuclear Information System (INIS)

    Greenspan, E.

    1977-06-01

    The economic potentials of fissile-fuel-producing light-water hybrid reactors (FFP-LWHR) and of fuel-self-sufficient (FSS) LWHR's are compared. A simple economic model is constructed that gives the capital investment allowed for the hybrid reactor so that the cost of electricity generated in the hybrid based energy system equals the cost of electricity generated in LWR's. The power systems considered are LWR, FSS-LWHR, and FFP-LWHR plus LWR, both with and without plutonium recycling. The economic potential of FFP-LWHR's is found superior to that of FSS-LWHR's. Moreover, LWHR's may compete, economically, with LWR's. Criteria for determining the more economical approach to hybrid fuel or power production are derived for blankets having a linear dependence between F and M. The examples considered favor the power generation rather than fuel production

  3. Generating Selected Color using RGB, Auxiliary Lights, and Simplex Search

    Directory of Open Access Journals (Sweden)

    Kim HyungTae

    2015-01-01

    Full Text Available A mixed light source generates various colors, with the potential to adjust intensities of multiple LEDs, which makes it possible to generate arbitrary colors. Currently, PCs and OSs provide color selection windows that can obtain the RGB or HSL color coordinates of a user’s selection. Mixed light sources are usually composed of LEDs in the primary colors, with LEDs in auxiliary colors such as white and yellow used in a few cases. When using auxiliary color LEDs, the number of LED inputs, the dimming levels, is larger than the number of elements in the color coordinate, which causes an under-determined problem. This study proposed how to determine the dimming levels of LEDs based on the selected color. Commercial LEDs have di_erent optical power values and impure color coordinates, even if they are RGB. Hence, the characteristics of the LEDs were described using a linear model derived from the tri-stimulus values (an XYZ color coordinate model and dimming levels. Color mixing models were derived for the arbitrary number of auxiliary color LEDs. The under-determined problem was solved using a simplex search method without an inverse matrix operation. The proposed method can be applied to a machine vision system and an RGBW light mixer for semiconductor inspection. The dimming levels, obtained using the proposed method were better than derived using other methods.

  4. Application of Foam-gel Technique to Control CO Exposure Generated During Spontaneous Combustion of Coal in Coal Mines.

    Science.gov (United States)

    Ren, Xing W; Wang, Feng Z; Guo, Qing; Zuo, Zhao B; Fang, Qi S

    2015-01-01

    In China, 47.3% of state-owned coal mines are located in coal seams that are prone to spontaneous combustion. The spontaneous combustion of coal is the main cause of the generation of a large amount of carbon monoxide, which can cause serious health issues to miners. A new technique using foam-gel formation was developed to effectively control the spontaneous combustion of coal. The gel can capture more than 90% of the water in the grout and at the same time the foam can cover dangerous areas in the goaf by stacking and cooling of foam in all directions. In this study, a mechanism of foam-gel formation was introduced and the optimal proportions of additives were defined based on experiments of different foaming properties, gelling time and water loss rate as the main index parameters. The results of a field application in a coal mine promise that this new technique would effectively prevent coal oxidation in the goaf and reduce the generation of carbon monoxide.

  5. Generation of an induced pluripotent stem cell line from chorionic villi of a Turner syndrome spontaneous abortion.

    Science.gov (United States)

    Parveen, Shagufta; Panicker, M M; Gupta, Pawan Kumar

    2017-03-01

    A major cause of spontaneous abortions is chromosomal abnormality of foetal cells. We report the generation of an induced pluripotent stem cell line from the fibroblasts isolated from chorionic villi of an early spontaneously aborted foetus with Turner syndrome. The Turner syndrome villus induced pluripotent stem cell line is transgene free, retains the original XO karyotype, expresses pluripotency markers and undergoes trilineage differentiation. This pluripotent stem cell model of Turner syndrome should serve as a tool to study the developmental abnormalities of foetus and placenta that lead to early embryo lethality and profound symptoms like infertility in 45 XO survivors. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

  6. Light-front quantized field theory: (an introduction). Spontaneous symmetry breaking. Phase transition in φ4 theory

    International Nuclear Information System (INIS)

    Srivastava, P.P.

    1993-01-01

    The field theory quantized on the light-front is compared with the conventional equal-time quantized theory. The arguments based on the micro causality principle would imply that the light-front field theory may become nonlocal with respect to the longitudinal coordinate even though the corresponding equal-time formulation is local. This is found to be the case for the scalar theory. The conventional instant form theory is sometimes required to be constrained by invoking external physical considerations; the analogous conditions seem to be already built in the theory on the light-front. In spite of the different mechanisms of the spontaneous symmetry breaking in the two forms of dynamics they result in the same physical content. The phase transition in (φ 4 ) 2 theory is also discussed. The symmetric vacuum state for vanishingly small couplings is found to turn into an unstable symmetric one when the coupling is increased and may result in a phase transition of the second order in contrast to the first order transition concluded from the usual variational methods. (author)

  7. New generation of light sources: Present and future

    International Nuclear Information System (INIS)

    Couprie, M.E.

    2014-01-01

    Spectroscopy and imaging in the VUV–X-ray domain are very sensitive tools for the investigation of the properties of matter [1–3]. Time-resolved studies enable to follow the movies of ultra-fast reactions. More than fifty years after the laser discovery [4], VUVX light sources are actively developed around the world. Among them, high order harmonics generated in gas, X-ray lasers, synchrotron radiation, free electron lasers are providing a wide offer, from laboratory size sources to large scale facilities, with various features, suitable for different types of experiments. The properties of these sources are here reviewed. Quest of new performances and flexibility is also discussed

  8. Characterization of the spontaneous light emission of the PMTs used in the Double Chooz experiment

    Science.gov (United States)

    Abe, Y.; Abrahão, T.; Alt, C.; Appel, S.; Bekman, I.; Bergevin, M.; Bezerra, T. J. C.; Bezrukov, L.; Blucher, E.; Brugière, T.; Buck, C.; Busenitz, J.; Cabrera, A.; Calvo, E.; Camilleri, L.; Carr, R.; Cerrada, M.; Chauveau, E.; Chimenti, P.; Collin, A. P.; Conover, E.; Conrad, J. M.; Crespo-Anadón, J. I.; Crum, K.; Cucoanes, A. S.; Damon, E.; Dawson, J. V.; de Kerret, H.; Dhooghe, J.; Dietrich, D.; Djurcic, Z.; dos Anjos, J. C.; Dracos, M.; Etenko, A.; Fallot, M.; Felde, J.; Fernandes, S. M.; Fischer, V.; Franco, D.; Franke, M.; Furuta, H.; Gil-Botella, I.; Giot, L.; Göger-Neff, M.; Gomez, H.; Gonzalez, L. F. G.; Goodenough, L.; Goodman, M. C.; Haag, N.; Hara, T.; Haser, J.; Hellwig, D.; Hofmann, M.; Horton-Smith, G. A.; Hourlier, A.; Ishitsuka, M.; Jiménez, S.; Jochum, J.; Jollet, C.; Kaether, F.; Kalousis, L. N.; Kamyshkov, Y.; Kaneda, M.; Kaplan, D. M.; Kawasaki, T.; Kemp, E.; Kryn, D.; Kuze, M.; Lachenmaier, T.; Lane, C. E.; Lasserre, T.; Letourneau, A.; Lhuillier, D.; Lima, H. P., Jr.; Lindner, M.; López-Castaño, J. M.; LoSecco, J. M.; Lubsandorzhiev, B.; Lucht, S.; Maeda, J.; Mariani, C.; Maricic, J.; Martino, J.; Matsubara, T.; Mention, G.; Meregaglia, A.; Miletic, T.; Minotti, A.; Nagasaka, Y.; Navas-Nicolás, D.; Novella, P.; Nunokawa, H.; Obolensky, M.; Onillon, A.; Osborn, A.; Palomares, C.; Pepe, I. M.; Perasso, S.; Porta, A.; Pronost, G.; Reichenbacher, J.; Reinhold, B.; Röhling, M.; Roncin, R.; Rybolt, B.; Sakamoto, Y.; Santorelli, R.; Schilithz, A. C.; Schönert, S.; Schoppmann, S.; Shaevitz, M. H.; Sharankova, R.; Shrestha, D.; Sibille, V.; Sinev, V.; Skorokhvatov, M.; Smith, E.; Soiron, M.; Spitz, J.; Stahl, A.; Stancu, I.; Stokes, L. F. F.; Strait, M.; Suekane, F.; Sukhotin, S.; Sumiyoshi, T.; Sun, Y.; Svoboda, R.; Terao, K.; Tonazzo, A.; Trinh Thi, H. H.; Valdiviesso, G.; Vassilopoulos, N.; Verdugo, A.; Veyssiere, C.; Vivier, M.; von Feilitzsch, F.; Wagner, S.; Walsh, N.; Watanabe, H.; Wiebusch, C.; Wurm, M.; Yang, G.; Yermia, F.; Zimmer, V.

    2016-08-01

    During the commissioning of the first of the two detectors of the Double Chooz experiment, an unexpected and dominant background caused by the emission of light inside the optical volume has been observed. A specific study of the ensemble of phenomena called Light Noise has been carried out in-situ, and in an external laboratory, in order to characterize the signals and to identify the possible processes underlying the effect. Some mechanisms of instrumental noise originating from the PMTs were identified and it has been found that the leading one arises from the light emission localized on the photomultiplier base and produced by the combined effect of heat and high voltage across the transparent epoxy resin covering the electric components. The correlation of the rate and the amplitude of the signal with the temperature has been observed. For the first detector in operation the induced background has been mitigated using online and offline analysis selections based on timing and light pattern of the signals, while a modification of the photomultiplier assembly has been implemented for the second detector in order to blacken the PMT bases.

  9. Spontaneous mutation 7B-1 in tomato impairs blue light-induced stomatal opening

    Czech Academy of Sciences Publication Activity Database

    Hlavinka, J.; Nauš, J.; Fellner, Martin

    2013-01-01

    Roč. 209, č. 2013 (2013), s. 75-80 ISSN 0168-9452 R&D Projects: GA ČR GD522/08/H003 Grant - others:GA ČR(CZ) GAP501/10/0785 Program:GA Institutional research plan: CEZ:AV0Z50380511 Keywords : ABA * Anion-channel blocker * Blue light Subject RIV: ED - Physiology Impact factor: 4.114, year: 2013

  10. Spontaneous and artificial generation of sheared flow in oblate FRCs in TS-3 and 4 FRC experiments

    International Nuclear Information System (INIS)

    Matsuyama, T.; Kawamori, E.; Ono, Y.; Tsuruda, M.; Sato, K.; Yamanoue, T.; Arimoto, K.; Itagaki, T.; Katsurai, M.

    2003-01-01

    Spontaneous formation of toroidal flow was measured for the first time in oblate FRCs produced in TS-3 and 4 experiments. The toroidal ion flow (V i ∼10km/sec) was found to peak around the magnetic axis, indicating formation of high flow shear inside the separatrix. The toroidal flow was observed to deform the magnetic field lines of the FRC, producing bipolar toroidal field profile. In high-s FRC (averaged number of ion gyro-radius 's'=4.5) with slow flow, its n=1 mode kept growing, causing collapse of the whole configuration. However, in low-s FRC (s=3) with fast flow, the rotating n=2 mode (saturated) became dominant after n=1 mode saturation. The spontaneous formation of flow shear possibly transformed the n=1 mode into the n=2 mode, suggesting a new sheared flow stabilization of n=1 mode. The flow shear was also generated artificially using the 'sling shot' effect of the counter helicity reconnection. The n=1 and 2 mode amplitudes were reduced down to 1/5-1/10 due to the generated flow shear. A new method for continuous sheared-flow generation was proposed for stabilization and heating of FRC by use of intermittent merging of spheromaks with opposing B t . (author)

  11. Spontaneous symmetry breaking of (1+1)-dimensional φ4 theory in light-front field theory. II

    International Nuclear Information System (INIS)

    Pinsky, S.S.; van de Sande, B.

    1994-01-01

    We discuss spontaneous symmetry breaking of (1+1)-dimensional φ 4 theory in light-front field theory using a Tamm-Dancoff truncation. We show that, even though light-front field theory has a simple vacuum state which is an eigenstate of the full Hamiltonian, the field can develop a nonzero vacuum expectation value. This occurs because the zero mode of the field must satisfy an operator-valued constraint equation. In the context of (1+1)-dimensional φ 4 theory we present solutions to the constraint equation using a Tamm-Dancoff truncation to a finite number of particles and modes. We study the behavior of the zero mode as a function of coupling and Fock space truncation. The zero mode introduces new interactions into the Hamiltonian which breaks the Z 2 symmetry of the theory when the coupling is stronger than the critical coupling. We investigate the energy spectrum in the symmetric and broken phases, show that the theory does not break down in the vicinity of the critical coupling, and discuss the connection to perturbation theory. Finally, we study the spectrum of the field φ and show that, in the broken phase, the field is localized away from φ=0 as one would expect from equal-time calculations. We explicitly show that tunneling occurs

  12. Exploring Spontaneous Imitation in Infancy: A Three Generation Inter-Familial Study

    Directory of Open Access Journals (Sweden)

    Theano Kokkinaki

    2013-05-01

    Full Text Available With the aim to advance our understanding regarding the role of the extended family interactional context for early mother-infant communication, we compared spontaneous early imitative exchanges in dyadic interactions between mothers and infants (Group 1, N = 26 who had no frequent contact with maternal grandmothers, to imitations in two familial subgroups (Group 2, N = 48: (a dyadic interactions of infants with their mothers, and (b with their grandmothers–persons who had frequent contact with the infant. Spontaneous dyadic interactions of infants with their mothers and grandmothers were video-recorded at home from the 2nd to the 10th month of their life. Both comparisons provided evidence of similar frequency of imitative exchanges and developmental trajectories of infant imitations, but also differences in the structure of imitation, the kinds of imitated behaviors and the temporal patterns of imitative components. In the frame of the theory of Innate Intersubjectivity, we assume that differential early family interaction may be related to variations in three fundamental dimensions of infant-significant other communication: “kinematics” (temporal patterns, “physiognomics” (spatial patterns or forms and “energetics” (force or effort. These variations may affect the child’s ability for regulation and negotiation of interpersonal challenges within and outside the family context.

  13. Light bulb heat exchanger for magnetohydrodynamic generator applications - Preliminary evaluation

    Science.gov (United States)

    Smith, J. M.; Hwang, C. C.; Seikel, G. R.

    1974-01-01

    The light-bulb heat-exchanger concept is investigated as a possible means of using a combustion heat source to supply energy to an inert gas MHD power generator system. In this concept, combustion gases flow through a central passage which consists of a duct with transparent walls through which heat is transferred by radiation to a radiation receiver which in turn heats the inert gas by convection. The effects of combustion-gas emissivity, transparent-wall-transmissivity, radiation-receiver emissivity, and the use of fins in the inert gas coolant passage are studied. The results indicate that inert gas outlet temperatures of 2500 K are possible for combustion temperatures of 3200 K and that sufficient energy can be transferred from the combustion gas to reduce its temperature to approximately 2000 K. At this temperature more conventional heat exchangers can be used.

  14. The potential and limitations of third generation light sources

    International Nuclear Information System (INIS)

    Hormes, Josef

    2011-01-01

    To date, 3rd generation Light Sources, i.e. electron storage rings where mainly radiation from insertion devices (wigglers and undulators) is used for synchrotron radiation experiments are the 'workhorses' for basic and applied VUV/X-ray research. Several machine parameters. i.e. the energy of the electrons, the emittance and the circumference of the machine, together with the specification of the corresponding insertion devices determine the 'quality' of a facility and a specific beamline. In this talk, several of these aspects are discussed mainly from a users' point of view, i.e. what are the required specifications to carry out 'state-of-the-art' experiments in various areas, e.g. protein crystallography, Resonant Elastic and Inelastic X-ray Scattering (REIXS), Micro-/nanospectroscopy, and time resolved experiments in the femtosecond time domain. (author)

  15. A Next Generation Light Source Facility at LBNL

    International Nuclear Information System (INIS)

    Corlett, J.N.; Austin, B.; Baptiste, K.M.; Byrd, J.M.; Denes, P.; Donahue, R.; Doolittle, L.; Falcone, R.W.; Filippetto, D.; Fournier, S.; Li, D.; Padmore, H.A.; Papadopoulos, C.; Pappas, C.; Penn, G.; Placidi, M.; Prestemon, S.; Prosnitz, D.; Qiang, J.; Ratti, A.; Reinsch, M.; Sannibale, F.; Schlueter, R.; Schoenlein, R.W.; Staples, J.W.; Vecchione, T.; Venturini, M.; Wells, R.; Wilcox, R.; Wurtele, J.; Charman, A.; Kur, E.; Zholents, A.A.

    2011-01-01

    The Next Generation Light Source (NGLS) is a design concept, under development at LBNL, for a multibeamline soft x-ray FEL array powered by a ∼2 GeV superconducting linear accelerator, operating with a 1 MHz bunch repetition rate. The CW superconducting linear accelerator is supplied by a high-brightness, high-repetition-rate photocathode electron gun. Electron bunches are distributed from the linac to the array of independently configurable FEL beamlines with nominal bunch rates up to 100 kHz in each FEL, and with even pulse spacing. Individual FELs may be configured for EEHG, HGHG, SASE, or oscillator mode of operation, and will produce high peak and average brightness x-rays with a flexible pulse format, with pulse durations ranging from sub-femtoseconds to hundreds of femtoseconds.

  16. Light third-generation squarks from flavour gauge messengers

    Energy Technology Data Exchange (ETDEWEB)

    Brümmer, Felix [SISSA/ISAS,Via Bonomea 265, Trieste I-34136 (Italy); Deutsches Elektronen-Synchrotron DESY,Notkestrasse 85, D-22607 Hamburg (Germany); McGarrie, Moritz [Deutsches Elektronen-Synchrotron DESY,Notkestrasse 85, D-22607 Hamburg (Germany); National Institute for Theoretical Physics, School of Physics,and Centre for Theoretical Physics, University of the Witwatersrand,Johannesburg, WITS 2050 (South Africa); Weiler, Andreas [Deutsches Elektronen-Synchrotron DESY,Notkestrasse 85, D-22607 Hamburg (Germany); CERN Theory Division,CH-1211 Geneva 23 (Switzerland)

    2014-04-10

    We study models of gauge-mediated supersymmetry breaking with a gauged horizontal SU(3){sub F} symmetry acting on the quark superfields. If SU(3){sub F} is broken non-supersymmetrically by F-term vacuum expectation values, the massive gauge bosons and gauginos become messengers for SUSY breaking mediation. These gauge messenger fields induce a flavour-dependent, negative contribution to the soft masses of the squarks at one loop. In combination with the soft terms from standard gauge mediation, one obtains large and degenerate first- and second-generation squark masses, while the stops and sbottoms are light. We discuss the implications of this mechanism for the superparticle spectrum and for flavour precision observables. We also provide an explicit realization in a model with simultaneous SUSY and SU(3){sub F} breaking.

  17. Light third-generation squarks from flavour gauge messengers

    Energy Technology Data Exchange (ETDEWEB)

    Bruemmer, Felix [International School for Advanced Studies, Trieste (Italy); Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); McGarrie, Moritz [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Univ. of the Witwatersrand, Johannesburg (South Africa). School of Physics and Centre for Theoretical Physics; Weiler, Andreas [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); CERN - European Organization for Nuclear Research, Geneva (Switzerland). Theory Div.

    2014-04-15

    We study models of gauge-mediated supersymmetry breaking with a gauged horizontal SU(3){sub F} symmetry acting on the quark superfields. If SU(3){sub F} is broken non-supersymmetrically by F-term vacuum expectation values, the massive gauge bosons and gauginos become messengers for SUSY breaking mediation. These gauge messenger fields induce a flavour-dependent, negative contribution to the soft masses of the squarks at one loop. In combination with the soft terms from standard gauge mediation, one obtains large and degenerate first- and second-generation squark masses, while the stops and sbottoms are light. We discuss the implications of this mechanism for the superparticle spectrum and for flavour precision observables. We also provide an explicit realization in a model with simultaneous SUSY and SU(3){sub F} breaking.

  18. Dead reckoning (path integration) requires the hippocampal formation: evidence from spontaneous exploration and spatial learning tasks in light (allothetic) and dark (idiothetic) tests.

    Science.gov (United States)

    Whishaw, I Q; Hines, D J; Wallace, D G

    2001-12-14

    Animals navigate using cues generated by their own movements (self-movement cues or idiothetic cues), as well as the cues they encounter in their environment (distal cues or allothetic cues). Animals use these cues to navigate in two different ways. When dead reckoning (deduced reckoning or path integration), they integrate self-movement cues over time to locate a present position or to return to a starting location. When piloting, they use allothetic cues as beacons, or they use the relational properties of allothetic cues to locate places in space. The neural structures involved in cue use and navigational strategies are still poorly understood, although considerable attention is directed toward the contributions of the hippocampal formation (hippocampus and associated pathways and structures, including the fimbria-fornix and the retrosplenial cortex). In the present study, using tests in allothetic and idiothetic paradigms, we present four lines of evidence to support the hypothesis that the hippocampal formation plays a central role in dead reckoning. (1) Control but not fimbria-fornix lesion rats can return to a novel refuge location in both light and dark (infrared) food carrying tasks. (2). Control but not fimbria-fornix lesion rats make periodic direct high velocity returns to a starting location in both light and dark exploratory tests. Control but not fimbria-fornix rats trained in the light to carry food from a fixed location to a refuge are able to maintain accurate outward and homebound trajectories when tested in the dark. (3). Control but not fimbria-fornix rats are able to correct an outward trajectory to a food source when the food source is moved when allothetic cues are present. These, tests of spontaneous exploration and foraging suggest a role for the hippocampal formation in dead reckoning.

  19. Coherent interference effects and squeezed light generation in optomechanical systems

    Science.gov (United States)

    Qu, Kenan

    My Ph.D. dissertation is on the fundamental effects in optomechanical systems (OMS) and their important applications. The OMS are based on the possibility of the mechanical motion produced by few photons incident on the mechanical device. This dissertation presents several applications of the OMS in the area of storage of light in long-lived phonons, single mode optomechanical Ramsey interferometry, and generation of large amount of squeezing in the output radiation. The long-lived phonons can be monitored and controlled via optical means as was experimentally demonstrated. To show this, I develop the theory of transient electromagnetically induced transparency (EIT). For further applications like state transfer, especially over very different frequency regimes, I consider double-cavity OMS, where the two cavities can correspond to different spectral domains, yet the state transfer is possible via phonons. The state transfer is based on a new effect, electromagnetically induced absorption (EIA), where one uses a second control field from the other cavity to produce an absorption peak inside the EIT window. All these involve the interference of various path ways via which a final state is reached. The following chapter shows how Fano-like interference can arise in OMS. A Fano asymmetry parameter for OMS was defined. The last two chapters deal with the question if OMS can be efficient generators of squeezed light. I show by blue and red tuning the two cavities in a double-cavity OMS, one can generate effectively a two-mode parametric interaction which yields two-mode squeezed output with the squeezing magnitude of the order of 10dB. This requires a bath temperature of 10mK. Such temperatures obtained by using Helium dilution refrigerator are routinely used with superconducting OMS. The major part of this dissertation is devoted to the dispersive optomechanical interaction. However, the interaction can also be dissipative, where the mechanical displacement modulates

  20. Light absorption properties of laboratory generated tar ball particles

    Science.gov (United States)

    Hoffer, A.; Tóth, A.; Nyirő-Kósa, I.; Pósfai, M.; Gelencsér, A.

    2015-06-01

    Tar balls (TBs) are a specific particle type which is abundant in the global troposphere, in particular in biomass smoke plumes. These particles belong to the family of atmospheric brown carbon (BrC) which can absorb light in the visible range of the solar spectrum. Albeit TBs are typically present as individual particles in biomass smoke plumes, their absorption properties have been only indirectly inferred from field observations or calculations based on their electron energy-loss spectra. This is because in biomass smoke TBs coexist with various other particle types (e.g. organic particles with inorganic inclusions and soot, the latter is emitted mainly during flaming conditions) from which they cannot be physically separated; thus, a direct experimental determination of their absorption properties is not feasible. Very recently we have demonstrated that TBs can be generated in the laboratory from droplets of wood tar that resemble atmospheric TBs in all of their observed properties. As a follow-up study we have installed on-line instruments to our laboratory set-up generating pure TB particles to measure the absorption and scattering, as well as size distribution of the particles. In addition, samples were collected for transmission electron microscopy (TEM) and total carbon (TC) analysis. The effects of experimental parameters were also studied. The mass absorption coefficients of the laboratory generated TBs were found to be in the range of 0.8-3.0 m2 g-1 at 550 nm, with absorption Ångström exponents (AAE) between 2.7 and 3.4 (average 2.9) in the wavelength range 467-652 nm. The refractive index of TBs as derived from Mie calculations was about 1.84-0.21i at 550 nm. In the brown carbon continuum these values fall closer to those of soot than to other light-absorbing species such as humic-like substances (HULIS). Considering the abundance of TBs in biomass smoke and the global magnitude of biomass burning emissions, these findings may have substantial

  1. Light absorption properties of laboratory-generated tar ball particles

    Science.gov (United States)

    Hoffer, A.; Tóth, A.; Nyirő-Kósa, I.; Pósfai, M.; Gelencsér, A.

    2016-01-01

    Tar balls (TBs) are a specific particle type that is abundant in the global troposphere, in particular in biomass smoke plumes. These particles belong to the family of atmospheric brown carbon (BrC), which can absorb light in the visible range of the solar spectrum. Albeit TBs are typically present as individual particles in biomass smoke plumes, their absorption properties have been only indirectly inferred from field observations or calculations based on their electron energy-loss spectra. This is because in biomass smoke TBs coexist with various other particle types (e.g., organic particles with inorganic inclusions and soot, the latter emitted mainly during flaming conditions) from which they cannot be physically separated; thus, a direct experimental determination of their absorption properties is not feasible. Very recently we have demonstrated that TBs can be generated in the laboratory from droplets of wood tar that resemble atmospheric TBs in all of their observed properties. As a follow-up study, we have installed on-line instruments to our laboratory set-up, which generate pure TB particles to measure the absorption and scattering, as well as the size distribution of the particles. In addition, samples were collected for transmission electron microscopy (TEM) and total carbon (TC) analysis. The effects of experimental parameters were also studied. The mass absorption coefficients of the laboratory-generated TBs were found to be in the range of 0.8-3.0 m2 g-1 at 550 nm, with absorption Ångström exponents (AAE) between 2.7 and 3.4 (average 2.9) in the wavelength range 467-652 nm. The refractive index of TBs as derived from Mie calculations was about 1.84 - 0.21i at 550 nm. In the brown carbon continuum, these values fall closer to those of soot than to other light-absorbing species such as humic-like substances (HULIS). Considering the abundance of TBs in biomass smoke and the global magnitude of biomass burning emissions, these findings may have

  2. Light absorption properties of laboratory-generated tar ball particles

    Directory of Open Access Journals (Sweden)

    A. Hoffer

    2016-01-01

    Full Text Available Tar balls (TBs are a specific particle type that is abundant in the global troposphere, in particular in biomass smoke plumes. These particles belong to the family of atmospheric brown carbon (BrC, which can absorb light in the visible range of the solar spectrum. Albeit TBs are typically present as individual particles in biomass smoke plumes, their absorption properties have been only indirectly inferred from field observations or calculations based on their electron energy-loss spectra. This is because in biomass smoke TBs coexist with various other particle types (e.g., organic particles with inorganic inclusions and soot, the latter emitted mainly during flaming conditions from which they cannot be physically separated; thus, a direct experimental determination of their absorption properties is not feasible. Very recently we have demonstrated that TBs can be generated in the laboratory from droplets of wood tar that resemble atmospheric TBs in all of their observed properties. As a follow-up study, we have installed on-line instruments to our laboratory set-up, which generate pure TB particles to measure the absorption and scattering, as well as the size distribution of the particles. In addition, samples were collected for transmission electron microscopy (TEM and total carbon (TC analysis. The effects of experimental parameters were also studied. The mass absorption coefficients of the laboratory-generated TBs were found to be in the range of 0.8–3.0 m2 g−1 at 550 nm, with absorption Ångström exponents (AAE between 2.7 and 3.4 (average 2.9 in the wavelength range 467–652 nm. The refractive index of TBs as derived from Mie calculations was about 1.84 − 0.21i at 550 nm. In the brown carbon continuum, these values fall closer to those of soot than to other light-absorbing species such as humic-like substances (HULIS. Considering the abundance of TBs in biomass smoke and the global magnitude of biomass burning

  3. Simulation of white light generation and near light bullets using a novel numerical technique

    Science.gov (United States)

    Zia, Haider

    2018-01-01

    An accurate and efficient simulation has been devised, employing a new numerical technique to simulate the derivative generalised non-linear Schrödinger equation in all three spatial dimensions and time. The simulation models all pertinent effects such as self-steepening and plasma for the non-linear propagation of ultrafast optical radiation in bulk material. Simulation results are compared to published experimental spectral data of an example ytterbium aluminum garnet system at 3.1 μm radiation and fits to within a factor of 5. The simulation shows that there is a stability point near the end of the 2 mm crystal where a quasi-light bullet (spatial temporal soliton) is present. Within this region, the pulse is collimated at a reduced diameter (factor of ∼2) and there exists a near temporal soliton at the spatial center. The temporal intensity within this stable region is compressed by a factor of ∼4 compared to the input. This study shows that the simulation highlights new physical phenomena based on the interplay of various linear, non-linear and plasma effects that go beyond the experiment and is thus integral to achieving accurate designs of white light generation systems for optical applications. An adaptive error reduction algorithm tailor made for this simulation will also be presented in appendix.

  4. Characterization of a spontaneously generated murine retinal pigmented epithelium cell line; a model for in vitro experiments

    Energy Technology Data Exchange (ETDEWEB)

    Ranaei Pirmardan, Ehsan [Department of Molecular Genetics, Faculty of Biological Sciences, Tarbiat Modares University, Tehran (Iran, Islamic Republic of); Soheili, Zahra-Soheila [Department of Molecular Medicine, National Institute of Genetic Engineering and Biotechnology, Tehran (Iran, Islamic Republic of); Samiei, Shahram [Blood Transfusion Research Center, High Institute for Research and Education in Transfusion Medicine, Tehran (Iran, Islamic Republic of); Ahmadieh, Hamid [Ophthalmic Research Center, Shahid Beheshti University of Medical Sciences, Tehran (Iran, Islamic Republic of); Mowla, Seyed Javad [Department of Molecular Genetics, Faculty of Biological Sciences, Tarbiat Modares University, Tehran (Iran, Islamic Republic of); Ezzati, Razie [Department of Molecular Medicine, National Institute of Genetic Engineering and Biotechnology, Tehran (Iran, Islamic Republic of); Naseri, Marzieh [Department of Molecular Medicine, Faculty of Advanced Technology, Iran University of Medical Sciences, Tehran (Iran, Islamic Republic of)

    2016-10-01

    Retinal pigmented epithelium (RPE), the outermost layer of the retina, has a key role in maintaining retinal cells’ functions. Severity of the culture of RPE cells has exerted many limitations to both in vitro and in vivo studies and its therapeutic applications. Therefore, establishment of RPE cell lines with high proliferative potential can considerably improve study of RPE cell biology. Here we report generation of a spontaneously immortalized murine RPE cell line in primary mouse RPE cell culture. Founded colonized cells were picked up and expression of RPE and retinal progenitor cells’ (RPC) markers were studied using immunocytochemistry (ICC). Emerged cells cultured over 35 passages and population doubling times in different serum concentrations were calculated. We also investigated the ability of cells for becoming transfected by calcium-phosphate method and for becoming infected by adeno-associated virus serotype 2 (AAV2) using flow cytometry. Data showed that the cobblestone constituent cells expressed RPE65, cytokeratin and ZO1 and moreover several progenitor markers such as Pax6, Sox2, Nestin and Chx10. It revealed that, despite primary RPE cells, the newly emerged cells were easily transfectable and were highly infectable when compared with HEK293T cells. Our data indicated that the emerged mouse RPE cell line pretended RPC-like phenotype and also simultaneously expressed RPE markers. It would be a promising model for leading studies on RPE and RPC cells and substantially confirmed the great RPE plasticity and its invaluable potential in research studies. - Highlights: • Isolation of a spontaneously generated retinal pigmented epithelium cell line is reported. • The cells express some of the retinal progenitor cell markers in addition to the RPE markers. • The aforesaid cell line is highly transfecable and considerably infectable by AAV2. • These results confirm the great RPE plasticity and its invaluable potential in research studies.

  5. Next Generation Luminaires: Recognizing Innovative, Energy-Efficient Commercial Lighting Luminaires

    Energy Technology Data Exchange (ETDEWEB)

    None

    2013-04-01

    Fact sheet that describes the Next Generation Luminaires SSL lighting design competition, which recognizes excellence in technical innovation and design of high-quality, energy-efficient commercial lighting, both indoor and outdoor.

  6. Spontaneous Generation of Electromotive Force in Thin Film Al/Nanosilicon/Al Structures

    Directory of Open Access Journals (Sweden)

    Sergey G. Dorofeev

    2017-10-01

    Full Text Available Contemporary pursuits in electronics include the miniaturization as well as flexibilization of devices. Although there are a large number of different thin and flexible electrochemical batteries, only a few can boast the possibility of working in high humidity conditions. This paper reports on the fabrication of structures consisting of films of silicon nanoparticles encased between two aluminium electrodes. The value of electromotive force (emf measured depends on the temperature of the sample and on the pressure of water vapor in the storage atmosphere and reaches approximately 1 V. Volt-ampere characteristics were investigated at different conditions to yield a model of emf generation in these structures. It was found that the reaction of water with silicon nanoparticles is the prime reason behind emf generation. Such a source may be introduced into electronic paper, and employed in the next generation of smart cards. The structure may also be manufactured directly on the surface of silicon chips, such as on the back of crystals in microschemes.

  7. A method for the rapid generation of nonsequential light-response curves of chlorophyll fluorescence.

    Science.gov (United States)

    Serôdio, João; Ezequiel, João; Frommlet, Jörg; Laviale, Martin; Lavaud, Johann

    2013-11-01

    Light-response curves (LCs) of chlorophyll fluorescence are widely used in plant physiology. Most commonly, LCs are generated sequentially, exposing the same sample to a sequence of distinct actinic light intensities. These measurements are not independent, as the response to each new light level is affected by the light exposure history experienced during previous steps of the LC, an issue particularly relevant in the case of the popular rapid light curves. In this work, we demonstrate the proof of concept of a new method for the rapid generation of LCs from nonsequential, temporally independent fluorescence measurements. The method is based on the combined use of sample illumination with digitally controlled, spatially separated beams of actinic light and a fluorescence imaging system. It allows the generation of a whole LC, including a large number of actinic light steps and adequate replication, within the time required for a single measurement (and therefore named "single-pulse light curve"). This method is illustrated for the generation of LCs of photosystem II quantum yield, relative electron transport rate, and nonphotochemical quenching on intact plant leaves exhibiting distinct light responses. This approach makes it also possible to easily characterize the integrated dynamic light response of a sample by combining the measurement of LCs (actinic light intensity is varied while measuring time is fixed) with induction/relaxation kinetics (actinic light intensity is fixed and the response is followed over time), describing both how the response to light varies with time and how the response kinetics varies with light intensity.

  8. Generation of Light with Multimode Time-Delayed Entanglement Using Storage in a Solid-State Spin-Wave Quantum Memory.

    Science.gov (United States)

    Ferguson, Kate R; Beavan, Sarah E; Longdell, Jevon J; Sellars, Matthew J

    2016-07-08

    Here, we demonstrate generating and storing entanglement in a solid-state spin-wave quantum memory with on-demand readout using the process of rephased amplified spontaneous emission (RASE). Amplified spontaneous emission (ASE), resulting from an inverted ensemble of Pr^{3+} ions doped into a Y_{2}SiO_{5} crystal, generates entanglement between collective states of the praseodymium ensemble and the output light. The ensemble is then rephased using a four-level photon echo technique. Entanglement between the ASE and its echo is confirmed and the inseparability violation preserved when the RASE is stored as a spin wave for up to 5  μs. RASE is shown to be temporally multimode with almost perfect distinguishability between two temporal modes demonstrated. These results pave the way for the use of multimode solid-state quantum memories in scalable quantum networks.

  9. Schrodinger cat state generation using a slow light

    International Nuclear Information System (INIS)

    Ham, B. S.; Kim, M. S.

    2003-01-01

    We show a practical application of giant Kerr nonlinearity to quantum information processing based on superposition of two distinct macroscopic states- Schrodinger cat state. The giant Kerr nonlinearity can be achieved by using electromagnetically induced transparency, in which light propagation should be slowed down so that a pi-phase shift can be easily obtained owing to increased interaction time.

  10. Illuminating Solar Decathlon Homes: Exploring Next Generation Lighting Technology - Light Emitting Diodes

    Energy Technology Data Exchange (ETDEWEB)

    Gordon, Kelly L.; Gilbride, Theresa L.

    2008-05-22

    This report was prepared by PNNL for the US Department of Energy Building Technologies Program, Solid-State Lighting Program. The report will be provided to teams of university students who are building houses for the 2009 Solar Decathlon, a home design competition sponsored in part by DOE, to encourage teams to build totally solar powered homes. One aspect of the competition is lighting. This report provides the teams with information about LED lighting that can help them determine how they incorporate LED lighting into their homes. The report provides an overview of LED technology, a status of where LED technology is today, questions and answers about lighting quality, efficiency, lifetime etc.; numerous examples of LED products; and several weblinks for further research.

  11. Using Nonuniform Fiber to Generate Slow Light via SBS

    Directory of Open Access Journals (Sweden)

    Wenhai Li

    2008-01-01

    Full Text Available The data pulse delay based on slow light induced by stimulated Brillouin scattering (SBS in a nonuniform dispersion decreasing fiber (DDF is demonstrated experimentally, and the distortions of data pulses at different beat frequencies are studied. We found that a delay exceeding a pulse width can be achieved at particular beat frequency, and the DDF has larger delay versus gain slope coefficient with much better output pulse quality than single-mode fiber.

  12. Spontaneous emission spectra and quantum light-matter interactions from a strongly coupled quantum dot metal-nanoparticle system

    DEFF Research Database (Denmark)

    Van Vlack, C.; Kristensen, Philip Trøst; Hughes, S.

    2012-01-01

    the dot to the detector, we demonstrate that the strong-coupling regime should be observable in the far-field spontaneous emission spectrum, even at room temperature. The vacuum-induced emission spectra show that the usual vacuum Rabi doublet becomes a rich spectral triplet or quartet with two of the four...

  13. Cylindrical plasmas generated by an annular beam of ultraviolet light

    Energy Technology Data Exchange (ETDEWEB)

    Thomas, D. M., E-mail: dmt107@imperial.ac.uk [Blackett Laboratory, Imperial College London, Prince Consort Road, London SW7 2BW (United Kingdom); Allen, J. E., E-mail: John.Allen@maths.ox.ac.uk [Blackett Laboratory, Imperial College London, Prince Consort Road, London SW7 2BW (United Kingdom); University College, University of Oxford, Oxford OX1 4BH, United Kingdom and OCIAM, Mathematical Institute, University of Oxford, Oxford OX2 6GG (United Kingdom)

    2015-07-15

    We investigate a cylindrical plasma system with ionization, by an annular beam of ultraviolet light, taking place only in the cylinder's outer region. In the steady state, both the outer and inner regions contain a plasma, with that in the inner region being uniform and field-free. At the interface between the two regions, there is an infinitesimal jump in ion density, the magnitude approaching zero in the quasi-neutral (λ{sub D} → 0) limit. The system offers the possibility of producing a uniform stationary plasma in the laboratory, hitherto obtained only with thermally produced alkali plasmas.

  14. Atomic physics research with second and third generation synchrotron light sources

    International Nuclear Information System (INIS)

    Johnson, B.M.

    1990-10-01

    This contribution to these proceedings is intended to provide an introduction and overview for other contributions on atomic (and related) physics research at existing and planned synchrotron light sources. The emphasis will be on research accomplishments and future opportunities, but a comparison will be given of operating characteristics for first, second, and third generation machines. First generation light sources were built to do research with the primary electron and positron beams, rather than with the synchrotron radiation itself. Second generation machines were specifically designed to be dedicated synchrotron-radiation facilities, with an emphasis on the use of bending-magnet radiation. The new third generation light sources are being designed to optimize radiation from insertion devices, such as undulators and wigglers. Each generation of synchrotron light source offers useful capabilities for forefront research in atomic physics and many other disciplines. 27 refs., 1 fig., 3 tabs

  15. Novel hybrid light emitting diodes with multiple assemblies of nanocrystals to generate and tune white light

    OpenAIRE

    Nizamoğlu, Sedat

    2007-01-01

    Cataloged from PDF version of article. Today approximately one third of the world population (about two billion people) in under-developed countries has no access to electricity and relies on unhealthy, costly and low-quality fuel-based lighting for home illumination. In the rest of the world, lighting consumes a large portion (20%) of the total electricity production, which significantly contributes to global warming problem. Also given limited resources, such large energy ...

  16. 3D computer generated medical holograms using spatial light modulators

    Directory of Open Access Journals (Sweden)

    Ahmed Sheet

    2014-09-01

    Full Text Available The aim of this work is to electronically generate the diffraction patterns of medical images and then trying to optically reconstruct the corresponding holographs to be displayed in space. This method is proposed in a trial to find a smart alternative of the expensive and perishable recording plates.

  17. High-power green light generation by second harmonic generation of single-frequency tapered diode lasers

    DEFF Research Database (Denmark)

    Jensen, Ole Bjarlin; Andersen, Peter E.; Sumpf, Bernd

    2010-01-01

    laser emits in excess of 9 W single-frequency output power with a good beam quality. The output from the tapered diode laser is frequency doubled using periodically poled MgO:LiNbO3. We investigate the modulation potential of the green light and improve the modulation depth from 1:4 to 1:50.......We demonstrate the generation of high power (>1.5W) and single-frequency green light by single-pass second harmonic generation of a high power tapered diode laser. The tapered diode laser consists of a DBR grating for wavelength selectivity, a ridge section and a tapered section. The DBR tapered...

  18. GHG PSD Permit: Cheyenne Light, Fuel & Power / Black Hills Power, Inc. – Cheyenne Prairie Generating Station

    Science.gov (United States)

    This page contains the final PSD permit for the Cheyenne Light, Fuel & Power / Black Hills Power, Inc. Cheyenne Prairie Generating Station, located in Laramie, Wyoming, and operated by Black Hills Service Company.

  19. Fundamental Scaling of Microplasmas and Tunable UV Light Generation.

    Energy Technology Data Exchange (ETDEWEB)

    Manginell, Ronald P. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Sillerud, Colin Halliday [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Hopkins, Matthew M. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Yee, Benjamin Tong [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Moorman, Matthew W. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Schwindt, Peter [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Anderson, John Moses [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Pfeifer, Nathaniel Bryant [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2016-11-01

    The temporal evolution of spectral lines from microplasma devices (MD) was studied, including impurity transitions. Long-wavelength emission diminishes more rapidly than deep UV with decreasing pulse width and RF operation. Thus, switching from DC to short pulsed or RF operation, UV emissions can be suppressed, allowing for real-time tuning of the ionization energy of a microplasma photo-ionization source, which is useful for chemical and atomic physics. Scaling allows MD to operate near atmospheric pressure where excimer states are efficiently created and emit down to 65 nm; laser emissions fall off below 200 nm, making MD light sources attractive for deep UV use. A first fully-kinetic three-dimensional model was developed that explicitly calculates electron-energy distribution function. This, and non-continuum effects, were studied with the model and how they are impacted by geometry and transient or DC operation. Finally, a global non-dimensional model was developed to help explain general trends MD physics.

  20. Amazon forest structure generates diurnal and seasonal variability in light utilization

    Science.gov (United States)

    Douglas C. Morton; Jeremy Rubio; Bruce D. Cook; Jean-Philippe Gastellu-Etchegorry; Marcos Longo; Hyeungu Choi; Maria Hunter; Michael Keller

    2016-01-01

    The complex three-dimensional (3-D) structure of tropical forests generates a diversity of light environments for canopy and understory trees. Understanding diurnal and seasonal changes in light availability is critical for interpreting measurements of net ecosystem exchange and improving ecosystem models. Here, we used the Discrete Anisotropic Radiative Transfer (DART...

  1. Lowering the pump power requirement for squeezed light generation using a periodically poled crystal

    DEFF Research Database (Denmark)

    Andersen, Ulrik Lund; Buchhave, Preben

    2003-01-01

    Observations of continuous wave bright squeezed light from an intra-cavity periodically poled KTP second harmonic generator are presented. The experiment includes characterization of the classical as well as the quantum properties of the system.......Observations of continuous wave bright squeezed light from an intra-cavity periodically poled KTP second harmonic generator are presented. The experiment includes characterization of the classical as well as the quantum properties of the system....

  2. Blue light irradiation-induced oxidative stress in vivo via ROS generation in rat gingival tissue.

    Science.gov (United States)

    Yoshida, Ayaka; Shiotsu-Ogura, Yukako; Wada-Takahashi, Satoko; Takahashi, Shun-suke; Toyama, Toshizo; Yoshino, Fumihiko

    2015-10-01

    It has been reported that oxidative stress with reactive oxygen species (ROS) generation is induced by blue light irradiation to a living body. Only limited research has been reported in dental field on the dangers of blue light, mostly focusing on cytotoxicity associated with heat injury of dental pulp. We thus performed an in vivo study on oral tissue exposed to blue light. ROS generated upon blue light irradiation of flavin adenine dinucleotide were measured by electron spin resonance spectroscopy. After blue light irradiation, the palatal gingiva of Wistar rats were isolated. Collected samples were subjected to biochemical analysis of lipid peroxidation and glutathione. Singlet oxygen was generated by blue light irradiation, but was significantly quenched in an N-acetyl-L-cysteine (NAC) concentration-dependent manner. Blue light significantly accelerated oxidative stress and increased the oxidized glutathione levels in gingival tissue. These effects were also inhibited by NAC pre-administration. The results suggest that blue light irradiation at clinical levels of tooth bleaching treatment may enhance lipid peroxidation by the induction of oxidative stress and the consumption of a significant amount of intracellular glutathione. In addition, NAC might be an effective supplement for the protection of oral tissues against blue light irradiation-induced oxidative damage. Copyright © 2015 Elsevier B.V. All rights reserved.

  3. A Versatile and Simple Approach to Generate Light Emission in Semiconductors Mediated by Electric Double Layers

    KAUST Repository

    Pu, Jiang

    2017-04-18

    The light-emitting device is the primary device for current light sources. In principle, conventional light-emitting devices need heterostructures and/or intentional carrier doping to form a p-n junction. This junction formation is, however, very difficult to achieve for most emerging semiconductors, and the fabrication of light-emitting devices is invariably a significant challenge. This study proposes a versatile and simple approach to realize light-emitting devices. This proposed device requires only a semiconducting film with two electrodes that are covered with an electrolyte. This unique structure achieves light emission at a voltage slightly larger than the bandgap energy of materials. This study applies this concept to emerging direct bandgap semiconductors, such as transition metal dichalcogenide monolayers and zinc oxide single crystals. These devices generate obvious light emission and provide sufficient evidence of the formation of a dynamic p-i-n junction or tunneling junction, presenting a versatile technique to develop optoelectronic devices.

  4. Comparison of the bonding strengths of second- and third-generation light-emitting diode light-curing units.

    Science.gov (United States)

    Lee, Hee-Min; Kim, Sang-Cheol; Kang, Kyung-Hwa; Chang, Na-Young

    2016-11-01

    With the introduction of third-generation light-emitting diodes (LEDs) in dental practice, it is necessary to compare their bracket-bonding effects, safety, and efficacy with those of the second-generation units. In this study, 80 extracted human premolars were randomly divided into eight groups of 10 samples each. Metal or polycrystalline ceramic brackets were bonded on the teeth using second- or third-generation LED light-curing units (LCUs), according to the manufacturers' instructions. The shear bond strengths were measured using the universal testing machine, and the adhesive remnant index (ARI) was scored by assessing the residual resin on the surfaces of debonded teeth using a scanning electron microscope. In addition, curing times were also measured. The shear bond strengths in all experimental groups were higher than the acceptable clinical shear bond strengths, regardless of the curing unit used. In both LED LCU groups, all ceramic bracket groups showed significantly higher shear bond strengths than did the metal bracket groups except the plasma emulation group which showed no significant difference. When comparing units within the same bracket type, no differences in shear bond strength were observed between the second- and third-generation unit groups. Additionally, no significant differences were observed among the groups for the ARI. The bracket-bonding effects and ARIs of second- and third-generation LED LCUs showed few differences, and most were without statistical significance; however, the curing time was shorter for the second-generation unit.

  5. Light-Induced Acid Generation on a Gatekeeper for Smart Nitric Oxide Delivery.

    Science.gov (United States)

    Choi, Hyung Woo; Kim, Jihoon; Kim, Jinhwan; Kim, Yonghwi; Song, Hyun Beom; Kim, Jeong Hun; Kim, Kimoon; Kim, Won Jong

    2016-04-26

    We report herein the design of a light-responsive gatekeeper for smart nitric oxide (NO) delivery. The gatekeeper is composed of a pH-jump reagent as an intermediary of stimulus and a calcium phosphate (CaP) coating as a shielding layer for NO release. The light irradiation and subsequent acid generation are used as triggers for uncapping the gatekeeper and releasing NO. The acids generated from a light-activated pH-jump agent loaded in the mesoporous nanoparticles accelerated the degradation of the CaP-coating layers on the nanoparticles, facilitating the light-responsive NO release from diazeniumdiolate by exposing a NO donor to physiological conditions. Using the combination of the pH-jump reagent and CaP coating, we successfully developed a light-responsive gatekeeper system for spatiotemporal-controlled NO delivery.

  6. Entangled photon pair generation by spontaneous parametric down-conversion in finite-length one-dimensional photonic crystals

    Czech Academy of Sciences Publication Activity Database

    Centini, M.; Peřina ml., Jan; Sciscione, L.; Sibilia, C.; Scalora, M.; Bloemer, M.J.; Bertolotti, M.

    2005-01-01

    Roč. 72, 03 (2005), 033806/1-033806/11 ISSN 1050-2947 R&D Projects: GA MŠk(CZ) OC P11.003 Institutional research plan: CEZ:AV0Z10100522 Keywords : photon pair * photonic crystals * spontaneous parametric down-conversion Subject RIV: BH - Optics, Masers, Lasers Impact factor: 2.997, year: 2005

  7. Role of volume and surface spontaneous parametric down-conversion in the generation of photon pairs in layered media

    Czech Academy of Sciences Publication Activity Database

    Javůrek, D.; Peřina ml., Jan

    2017-01-01

    Roč. 95, č. 4 (2017), s. 1-13, č. článku 043828. ISSN 2469-9926 Institutional support: RVO:68378271 Keywords : surface spontaneous * parametric down-conversion * photon pairs * layered media Subject RIV: BH - Optics, Masers, Lasers OBOR OECD: Optics (including laser optics and quantum optics) Impact factor: 2.925, year: 2016

  8. Supplemental material: afterburner for generating light (anti-)nuclei with QCD-inspired event generators in pp collisions

    CERN Document Server

    2017-01-01

    This note complements the paper titled: ``Production of deuterons, tritons, $^{3}$He nuclei and their anti-nuclei in pp collisions at $\\sqrt{s}$~=~0.9, 2.76 and 7~TeV'' with additional material related to Monte Carlo simulations necessary to compare the results with lower energy experiments. It describes a coalescence-based afterburner for QCD-inspired event generators, which allows the generation of light nuclei, hyper-nuclei and their charge conjugates in proton--proton (pp) collisions at LHC energies. The event generators with the afterburner are able to reproduce the differential cross sections of light (anti-)nuclei ($A<4)$ with the same degree of agreement as those of protons and anti-protons at the same momentum per nucleon. They also explain the transverse momentum dependence of the coalescence parameters as the result of hard scattering effects.

  9. Generation of pulsed light in the visible spectral region based on non-linear cavity dumping

    DEFF Research Database (Denmark)

    Johansson, Sandra; Andersen, Martin; Tidemand-Lichtenberg, Peter

    We propose a novel generic approach for generation of pulsed light in the visible spectrum based on sum-frequency generation between the high circulating intra-cavity power of a high finesse CW laser and a single-passed pulsed laser. For demonstration, we used a CW 1342 nm laser mixed with a pass...

  10. Diatom growth responses to photoperiod and light are predictable from diel reductant generation.

    Science.gov (United States)

    Li, Gang; Talmy, David; Campbell, Douglas A

    2017-02-01

    Light drives phytoplankton productivity, so phytoplankton must exploit variable intensities and durations of light exposure, depending upon season, latitude, and depth. We analyzed the growth, photophysiology and composition of small, Thalassiosira pseudonana, and large, Thalassiosira punctigera, centric diatoms from temperate, coastal marine habitats, responding to a matrix of photoperiods and growth light intensities. T. pseudonana showed fastest growth rates under long photoperiods and low to moderate light intensities, while the larger T. punctigera showed fastest growth rates under short photoperiods and higher light intensities. Photosystem II function and content responded primarily to instantaneous growth light intensities during the photoperiod, while diel carbon fixation and RUBISCO content responded more to photoperiod duration than to instantaneous light intensity. Changing photoperiods caused species-specific changes in the responses of photochemical yield (e - /photon) to growth light intensity. These photophysiological variables showed complex responses to photoperiod and to growth light intensity. Growth rate also showed complex responses to photoperiod and growth light intensity. But these complex responses resolved into a close relation between growth rate and the cumulative daily generation of reductant, across the matrix of photoperiods and light intensities. © 2016 The Authors. Journal of Phycology published by Wiley Periodicals, Inc. on behalf of Phycological Society of America.

  11. Singly-resonant sum frequency generation of visible light in a semiconductor disk laser

    DEFF Research Database (Denmark)

    Andersen, Martin Thalbitzer; Schlosser, P.J.; Hastie, J.E.

    2009-01-01

    In this paper a generic approach for visible light generation is presented. It is based on sum frequency generation between a semiconductor disk laser and a solid-state laser, where the frequency mixing is achieved within the cavity of the semiconductor disk laser using a singlepass of the solid......-state laser light. This exploits the good beam quality and high intra-cavity power present in the semiconductor disk laser to achieve high conversion efficiency. Combining sum frequency mixing and semiconductor disk lasers in this manner allows in principle for generation of any wavelength within the visible...

  12. Visible light-driven photocatalytic generation of sulfonamidyl radicals for alkene hydroamination of unsaturated sulfonamides.

    Science.gov (United States)

    Chen, Jun; Guo, Hong-Mei; Zhao, Quan-Qing; Chen, Jia-Rong; Xiao, Wen-Jing

    2018-02-05

    A visible light-driven photocatalytic generation of sulfonamidyl radicals, and application to intramolecular alkene hydroamination, has been accomplished, providing a mild and efficient approach to various functionalized isoxazolidines. The success of this protocol is based on the strategy of oxidative deprotonation electron transfer by merging the base and the photocatalyst under visible light irradiation, obviating installation of a photolabile handle or stoichiometric external oxidants.

  13. Broadband light generation at ~1300 nm through spectrally recoiled solitons and dispersive waves

    DEFF Research Database (Denmark)

    Falk, Peter Andreas; Frosz, Michael Henoch; Bang, Ole

    2008-01-01

    We experimentally study the generation of broadband light at ~1300 nm from an 810 nm Ti:sapphire femtosecond pump laser. We use two photonic crystal fibers with a second infrared zero-dispersion wavelength (λZ2) and compare the efficiency of two schemes: in one fiber λZ2=1400 nm and the light...... at 1300 nm is composed of spectrally recoiled solitons; in the other fiber λZ2=1200 nm and the light at 1300 nm is composed of dispersive waves....

  14. Curing performance of a new-generation light-emitting diode dental curing unit.

    Science.gov (United States)

    Wiggins, Kim M; Hartung, Martin; Althoff, Olaf; Wastian, Christine; Mitra, Sumita B

    2004-10-01

    BACKGROUND; Recent technological advances have resulted in the marketing of high-powered, or HP, battery-operated light-emitting diode, or LED, dental curing lights. The authors examine the curing efficiency and peak polymerization temperature, or Tp, of a new HP LED curing light. The authors studied four visible light-curing, or VLC, units: HP LED (A), first-generation LED (B), conventional halogen (C) and high-intensity halogen (D). They determined the depth of cure, or DOC; adhesion; and Tp of three types of VLC resin-based composites after exposure to each light. The exposure times for units A and D were one-half those for units B and C. The power density of unit A was 1,000 milliwatts per square centimeter, which was comparable to that of unit D with turbo charge. The DOC and adhesion attained for all three resin-based composites after being light cured by unit A for a 10-second exposure time were equivalent to those after being light cured by unit D for a 10-second exposure time and to those after being light cured by units B and C for 20-second exposure times. The resin-based composites light cured by unit A attained significantly lower Tps than did those light cured by unit D at equivalent cure, or exposure, times and by unit C at twice the cure time. The authors found that Unit A effectively cured the resin-based composites at one-half the cure time of units B and C and at the same time as unit D, while maintaining low Tp. The battery-operated HP LED curing light might be an effective, time-saving alternative for clinicians to use in light curing resin-based composites.

  15. Phase study of the generated surface plasmon waves in light transmission through a subwavelength aperture

    DEFF Research Database (Denmark)

    Hashemi, Mahdieh; Xiao, Sanshui; Farzad, Mahmood Hosseini

    2014-01-01

    Interference of surface plasmon (SP) waves plays a key role in light transmission through a subwavelength aperture surrounded by groove structures. In order to characterize interference of the hole and groove-generated SP waves, their phase information was carefully investigated using finite...... difference time domain simulations. In a structure with only one groove, constructive interference of the generated SP waves will enhance transmitted light by a factor of 5.4 compared with that of a single hole. Increasing the groove number to 3 in the design, which supports constructive interference of SP...... waves, will enhance the transmission coefficient to 10.5 times that for the single-hole transmission coefficient....

  16. Spontaneous Ag-Nanoparticle Growth at Single-Walled Carbon Nanotube Defect Sites: A Tool for In Situ Generation of SERS Substrate

    Directory of Open Access Journals (Sweden)

    Jason Maley

    2011-01-01

    Full Text Available Silver nanoparticles were spontaneously formed on pristine and oxidized single-wall nanotubes. Nanoparticles were observed on carbon nanotubes with AFM, and the presence of Ag nanoparticles were confirmed by ESR experiments. Raman spectroscopy of the Ag-treated carbon nanotubes had a 4–10X enhancement of intensity compared to untreated carbon nanotubes. Ag nanoparticles formed at defect sites on the CNT surface, where free electrons located at the defect sites reduced Ag+ to Ag. A mechanism for the propagation of the nanoparticles is through a continual negative charge generation on the nanoparticle by electron transfer from doublet oxygen (O2−.

  17. Design mechanic generator under speed bumper to support electricity recourse for urban traffic light

    Science.gov (United States)

    Sabri, M.; Lauzuardy, Jason; Syam, Bustami

    2018-03-01

    The electrical energy needs for the traffic lights in some cities of developing countries cannot be achieved continuously due to limited capacity and interruption of electricity distribution, the main power plant. This issues can lead to congestion at the crossroads. To overcome the problem of street chaos due to power failure, we can cultivate to provide electrical energy from other sources such as using the bumper to generate kinetic energy, which can be converted into electrical energy. This study designed a generator mechanic that will be mounted on the bumper construction to generate electricity for the purposes of traffic lights at the crossroads. The Mechanical generator is composed of springs, levers, sprockets, chains, flywheel and customize power generator. Through the rotation of the flywheel, we can earned 9 Volt DC voltage and electrical current of 5.89 Ampere. This achievement can be used to charge the accumulator which can be used to power the traffic lights, and to charge the accumulator capacity of 6 Ah, the generator works in the charging time for 1.01 hours.

  18. Effect of loss on slow-light-enhanced second-harmonic generation in periodic nanostructures

    DEFF Research Database (Denmark)

    Saravi, Sina; Quintero-Bermudez, Rafael; Setzpfandt, Frank

    2016-01-01

    We theoretically analyze the dependence of second-harmonic generation efficiency on the group index in periodic optical waveguides with loss. We investigate different possible scenarios of using slow light to enhance the efficiency of this process and show that in some cases there exists a maxima...

  19. Photocatalytic generation of hydrogen under visible light on La2CuO4

    Indian Academy of Sciences (India)

    1043–1048. c Indian Academy of Sciences. Photocatalytic generation of hydrogen under visible light on La2CuO4 .... phase was identified by X-ray diffraction using Cu Kα radi- ation (λ = 0.154178 nm). The diffuse ..... Omeiri S, Allalou N, Rekhila G, Bessekhouad Y and Trari M. 2013 Appl. Nanosci. 1 8. 10. Tiwari S and ...

  20. Ultraviolet Light Generation and Transport in the Final Optics Assembly of the National Ignition Facility

    Energy Technology Data Exchange (ETDEWEB)

    Wegner, P. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Hackel, L. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Feit, M. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Parham, T. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Kozlowski, M. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Whitman, P. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2015-02-12

    The design of the National Ignition Facility (NIF) includes a Final Optics Assembly (FOA) subsystem for ultraviolet (UV) light generation and transport for each of the 192 beamlines. Analytical and experimental work has been done to help understand and predict the performance of FOA.

  1. An Enantioselective Synthetic Route toward Second-Generation Light-Driven Rotary Molecular Motors

    NARCIS (Netherlands)

    Pijper, Thomas C.; Pijper, Dirk; Pollard, Michael M.; Dumur, Frederic; Davey, Stephen G.; Meetsma, Auke; Feringa, Ben L.

    2010-01-01

    Controlling the unidirectional rotary process of second-gene ration molecular motors demands access to these motors in their enantiomerically Pure form. In this paper, we describe an enantioselective route to three new second-generation light-driven molecular motors. Their synthesis starts with the

  2. Quilotórax espontâneo associado a atividade física leve Spontaneous chylothorax associated with light physical activity

    Directory of Open Access Journals (Sweden)

    José Carlos Miranda Torrejais

    2006-12-01

    Full Text Available O quilotórax ocorre quando há ruptura, laceração ou obstrução do ducto torácico, com liberação de quilo no espaço pleural. Pode acontecer em malformações linfáticas congênitas, linfomas, tumores de mediastino, doenças infecciosas, procedimentos cirúrgicos, traumas automobilísticos, ou ser idiopático. Apresenta sinais clínicos de dispnéia, hipotensão, edema generalizado e cianose. O diagnóstico geralmente é feito por toracocentese e o tratamento é conservador. O quilotórax espontâneo é uma condição incomum de derrame pleural, e somente é hipótese diagnóstica após a exclusão das demais causas. Descrevemos um caso de quilotórax espontâneo associado a atividade física leve em academia de ginástica.Chylothorax occurs when there is rupture, laceration or obstruction of the thoracic duct, resulting in the release of chyle into the pleural space. Chylothorax can occur in cases of congenital lymphatic malformation, lymphoma, mediastinal tumor and infectious disease, as well as during surgical procedures and after traffic accident-related trauma. It can also be idiopathic. The condition presents clinical signs of dyspnea, hypotension, generalized edema and cyanosis. The diagnosis is usually made through thoracocentesis, and the treatment is conservative. Spontaneous chylothorax is an uncommon form of pleural effusion, and its diagnosis should be hypothesized only after all other causes have been ruled out. Herein, we describe a case of spontaneous chylothorax associated with light physical activity at a fitness center.

  3. White Light Generation and Anisotropic Damage in Gold Films near Percolation Threshold

    DEFF Research Database (Denmark)

    Novikov, Sergey M.; Frydendahl, Christian; Beermann, Jonas

    2017-01-01

    damage with TPL images being sensitive to both wavelength and polarization of illuminating light. We relate these effects to thermally induced morphological changes observed with scanning electron microscopy images. Exciting physics involved in light interaction with near-percolation metal films along...... in vanishingly small gaps between gold islands in thin films near the electrically determined percolation threshold. Optical explorations using two-photon luminescence (TPL) and near-field microscopies reveals supercubic TPL power dependencies with white-light spectra, establishing unequivocally...... that the strongest TPL signals are generated close to the percolation threshold films, and occurrence of extremely confined (similar to 30 nm) and strongly enhanced (similar to 100 times) fields at the illumination wavelength. For linearly polarized and sufficiently powerful light, we observe pronounced optical...

  4. A Versatile and Simple Approach to Generate Light Emission in Semiconductors Mediated by Electric Double Layers.

    Science.gov (United States)

    Pu, Jiang; Fujimoto, Taiyo; Ohasi, Yuki; Kimura, Shota; Chen, Chang-Hsiao; Li, Lain-Jong; Sakanoue, Tomo; Takenobu, Taishi

    2017-06-01

    The light-emitting device is the primary device for current light sources. In principle, conventional light-emitting devices need heterostructures and/or intentional carrier doping to form a p-n junction. This junction formation is, however, very difficult to achieve for most emerging semiconductors, and the fabrication of light-emitting devices is invariably a significant challenge. This study proposes a versatile and simple approach to realize light-emitting devices. This proposed device requires only a semiconducting film with two electrodes that are covered with an electrolyte. This unique structure achieves light emission at a voltage slightly larger than the bandgap energy of materials. This study applies this concept to emerging direct bandgap semiconductors, such as transition metal dichalcogenide monolayers and zinc oxide single crystals. These devices generate obvious light emission and provide sufficient evidence of the formation of a dynamic p-i-n junction or tunneling junction, presenting a versatile technique to develop optoelectronic devices. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Modeling and Analysis of Entropy Generation in Light Heating of Nanoscaled Silicon and Germanium Thin Films

    Directory of Open Access Journals (Sweden)

    José Ernesto Nájera-Carpio

    2015-07-01

    Full Text Available In this work, the irreversible processes in light heating of Silicon (Si and Germanium (Ge thin films are examined. Each film is exposed to light irradiation with radiative and convective boundary conditions. Heat, electron and hole transport and generation-recombination processes of electron-hole pairs are studied in terms of a phenomenological model obtained from basic principles of irreversible thermodynamics. We present an analysis of the contributions to the entropy production in the stationary state due to the dissipative effects associated with electron and hole transport, generation-recombination of electron-hole pairs as well as heat transport. The most significant contribution to the entropy production comes from the interaction of light with the medium in both Si and Ge. This interaction includes two processes, namely, the generation of electron-hole pairs and the transferring of energy from the absorbed light to the lattice. In Si the following contribution in magnitude comes from the heat transport. In Ge all the remaining contributions to entropy production have nearly the same order of magnitude. The results are compared and explained addressing the differences in the magnitude of the thermodynamic forces, Onsager’s coefficients and transport properties of Si and Ge.

  6. Spontaneous pneumothorax

    Directory of Open Access Journals (Sweden)

    Davari R

    1996-07-01

    Full Text Available A case with bilateral spontaneous pneumothorax was presented. Etiology, mechanism, and treatment were discussed on the review of literature. Spontaneous Pneumothorax is a clinical entity resulting from a sudden non traumatic rupture of the lung. Biach reported in 1880 that 78% of 916 patients with spontaneous pneumothorax had tuberculosis. Kjergaard emphasized 1932 the primary importance of subpleural bleb disease. Currently the clinical spectrum of spontaneous pneumothorax seems to have entered a third era with the recognition of the interstitial lung disease and AIDS as a significant etiology. Standard treatment is including: observation, thoracocentesis, tube thoracostomy. Chemical pleurodesis, bullectomy or wedge resection of lung with pleural abrasion and occasionally pleurectomy. Little information has been reported regarding the efficacy of such treatment in spontaneous pneumothorax secondary to non bleb disease

  7. Spontaneous dimensional reduction?

    Science.gov (United States)

    Carlip, Steven

    2012-10-01

    Over the past few years, evidence has begun to accumulate suggesting that spacetime may undergo a "spontaneous dimensional reduction" to two dimensions near the Planck scale. I review some of this evidence, and discuss the (still very speculative) proposal that the underlying mechanism may be related to short-distance focusing of light rays by quantum fluctuations.

  8. Parametric Processes for Generation and Low Noise Detection of Infrared Light

    DEFF Research Database (Denmark)

    Høgstedt, Lasse

    . The first chapter of the thesis introduces and motivates the work with frequency conversion, sketching the potential of the noise properties for upconversion based detection systems and the increased wavelength availability for parametric light sources. A selection of prior work is presented to give...... an overview of the focus in the field and to place the thesis in a general context. The second chapter introduces the basic concepts of nonlinear parametric interaction in the context of this work, where phasematching is a key factor in the work on both light sources and detection systems. Third chapter...... presents the work on infrared light sources. An optical parametric generator was constructed, and worked as an optical parametric amplifier for both a near- and a mid-infrared seed. The setups are analyzed spectrally and temporally, and discussed with respect to spectroscopic applications. It is concluded...

  9. A simple sub-nanosecond ultraviolet light pulse generator with high repetition rate and peak power.

    Science.gov (United States)

    Binh, P H; Trong, V D; Renucci, P; Marie, X

    2013-08-01

    We present a simple ultraviolet sub-nanosecond pulse generator using commercial ultraviolet light-emitting diodes with peak emission wavelengths of 290 nm, 318 nm, 338 nm, and 405 nm. The generator is based on step recovery diode, short-circuited transmission line, and current-shaping circuit. The narrowest pulses achieved have 630 ps full width at half maximum at repetition rate of 80 MHz. Optical pulse power in the range of several hundreds of microwatts depends on the applied bias voltage. The bias voltage dependences of the output optical pulse width and peak power are analysed and discussed. Compared to commercial UV sub-nanosecond generators, the proposed generator can produce much higher pulse repetition rate and peak power.

  10. Green bright squeezed light from a cw periodically poled KTP second harmonic generator

    DEFF Research Database (Denmark)

    Andersen, Ulrik Lund; Buchhave, Preben

    2002-01-01

    We present the experimental observation of bright amplitude squeezed light from a singly resonant second harmonic generator (SHG) based on a periodically poled potassium titanyl phosphate (KTP) crystal. Contrary to conventional SHG, the interacting waves in this device couple efficiently using...... quasi phase matching (QPM) and more importantly QPM allows access to higher valued elements of the nonlinear tensor than is possible under the constraint of birefringence phase matching. We observe a noise reduction of 13% below the shot noise limit in the generated second harmonic field. This noise...

  11. Light-induced electric field generated by photovoltaic substrates investigated through liquid crystal reorientation

    Science.gov (United States)

    Lucchetti, L.; Kushnir, K.; Reshetnyak, V.; Ciciulla, F.; Zaltron, A.; Sada, C.; Simoni, F.

    2017-11-01

    Liquid crystal reorientation is exploited to analyze the electric field generated by light irradiation in iron-doped lithium niobate crystals. The evaluation of the strength of this light-induced field is based on the measurement of the phase shift induced in a probe light beam by a liquid crystal cell built with two z-cut iron-doped lithium niobate crystals as substrates. Then, the field profile has been determined starting from a Gaussian-like surface charge density following the model described in the text. The director profile corresponding to the modelled electric field is in good agreement with the director reorientation evaluated experimentally by means of the light-induced phase shift. This investigation gives a new approach to study the effects based on the photovoltaic response of lithium niobate crystals. Moreover, the characterization of the electric field optically generated inside the LC layer is highly desirable in view of the realization of new all-optical devices to be integrated in optofluidic platforms.

  12. The generation of flat-top beams by complex amplitude modulation with a phase-only spatial light modulator

    CSIR Research Space (South Africa)

    Hendriks, A

    2012-08-01

    Full Text Available Phase-only spatial light modulators are now ubiquitous tools in modern optics laboratories, and are often used to generate so-called structured light. In this work we outline the use of a phase-only spatial light modulator to achieve full complex...

  13. Advances in light-curing units: four generations of LED lights and clinical implications for optimizing their use: Part 2. From present to future.

    Science.gov (United States)

    Shortall, Adrian C; Palin, Will M; Jacquot, Bruno; Pelissier, Bruno

    2012-01-01

    The first part of this series of two described the history of light curing in dentistry and developments in LED lights since their introduction over 20 years ago. Current second- and third-generation LED light units have progressively replaced their halogen lamp predecessors because of their inherent advantages. The background to this, together with the clinical issues relating to light curing and the possible solutions, are outlined in the second part of this article. Finally, the innovative features of what may be seen as the first of a new fourth-generation of LED lights are described and guidance is given for the practitioner on what factors to consider when seeking to purchase a new LED light activation unit. Adequate curing in depth is fundamental to clinical success with any light-activated restoration. To achieve this goal predictably, an appropriate light source needs to be combined with materials knowledge, requisite clinical skills and attention to detail throughout the entire restoration process. As dentists increasingly use light-cured direct composites to restore large posterior restorations they need to appreciate the issues central to effective and efficient light curing and to know what to look for when seeking to purchase a new light-curing unit.

  14. 76 FR 26284 - FirstLight Hydro Generating Company, City of Norwich Dept. of Public Utilities; Notice of Meeting

    Science.gov (United States)

    2011-05-06

    ... will meet with FirstLight Hydro Generating Company and the City of Norwich Dept. of Public Utilities to... Energy Regulatory Commission FirstLight Hydro Generating Company, City of Norwich Dept. of Public Utilities; Notice of Meeting a. Date and Time of Meeting: Tuesday, May 17, 2011 from 10 a.m. to 12 p.m. EDT...

  15. A new approach to sum frequency generation of single-frequency blue light in a coupled ring cavity

    DEFF Research Database (Denmark)

    Jensen, Ole Bjarlin; Petersen, Paul Michael

    2014-01-01

    We present a generic approach for the generation of tunable single-frequency light and demonstrate generation of more than 300 mW tunable light around 460 nm. One tapered diode laser is operated in a coupled ring cavity containing the nonlinear crystal and another tapered diode laser is sent thro...

  16. The ARC-EN-CIEL French 4th Generation Light Source

    Science.gov (United States)

    Bruni, C.; Couprie, M. E.; Chubar, O.; Loulergue, A.; Nahon, L.; Carré, B.; Garzella, D.; Labat, M.; Lambert, G.; Monot, P.; Jablonka, M.; Méot, F.; Mosnier, A.; Marquès, J. R.; Ortega, J. M.; Nutarelli, D.

    2007-01-01

    ARC-EN-CIEL (Accelerator-Radiation Complex for Enhanced Coherent Intense Extended Light) proposal is based on a CW 1 GeV superconducting linear accelerator delivering high charge, subpicosecond, low emittance electron bunches with a high repetition rate (1 kHz). The FEL uses High Harmonics Generation in gases in a High Gain Harmonic Generation scheme, leading to a rather compact solution. The radiation extends down to 0.8 nm with the non-linear harmonics and reproduces the good longitudinal and transverse coherence of the harmonics generated in gas. Optional beam loops, foreseen to increase the beam current or the energy, will accommodate infrared CSR source, femtosecond undulator sources in the VUV and X-ray ranges, and a FEL oscillator in the 10 nm range. An important synergy is expected between accelerator and laser communities, in particular for electron plasma acceleration tests.

  17. Compact Quantum Random Number Generator with Silicon Nanocrystals Light Emitting Device Coupled to a Silicon Photomultiplier

    Science.gov (United States)

    Bisadi, Zahra; Acerbi, Fabio; Fontana, Giorgio; Zorzi, Nicola; Piemonte, Claudio; Pucker, Georg; Pavesi, Lorenzo

    2018-02-01

    A small-sized photonic quantum random number generator, easy to be implemented in small electronic devices for secure data encryption and other applications, is highly demanding nowadays. Here, we propose a compact configuration with Silicon nanocrystals large area light emitting device (LED) coupled to a Silicon photomultiplier to generate random numbers. The random number generation methodology is based on the photon arrival time and is robust against the non-idealities of the detector and the source of quantum entropy. The raw data show high quality of randomness and pass all the statistical tests in national institute of standards and technology tests (NIST) suite without a post-processing algorithm. The highest bit rate is 0.5 Mbps with the efficiency of 4 bits per detected photon.

  18. Compact Quantum Random Number Generator with Silicon Nanocrystals Light Emitting Device Coupled to a Silicon Photomultiplier

    Directory of Open Access Journals (Sweden)

    Zahra Bisadi

    2018-02-01

    Full Text Available A small-sized photonic quantum random number generator, easy to be implemented in small electronic devices for secure data encryption and other applications, is highly demanding nowadays. Here, we propose a compact configuration with Silicon nanocrystals large area light emitting device (LED coupled to a Silicon photomultiplier to generate random numbers. The random number generation methodology is based on the photon arrival time and is robust against the non-idealities of the detector and the source of quantum entropy. The raw data show high quality of randomness and pass all the statistical tests in national institute of standards and technology tests (NIST suite without a post-processing algorithm. The highest bit rate is 0.5 Mbps with the efficiency of 4 bits per detected photon.

  19. Efficient generation of 509 nm light by sum-frequency mixing between two tapered diode lasers

    DEFF Research Database (Denmark)

    Tawfieq, Mahmoud; Jensen, Ole Bjarlin; Hansen, Anders Kragh

    2015-01-01

    We demonstrate a concept for visible laser sources based on sum-frequency generation of beam com- bined tapered diode lasers. In this specific case, a 1.7 W sum-frequency generated green laser at 509 nm is obtained, by frequency adding of 6.17 W from a 978 nm tapered diode laser with 8.06 W from...... a 1063 nm tapered diode laser, inside a periodically poled MgO doped lithium niobate crystal. This corresponds to an optical to optical conversion ef fi ciency of 12.1%. As an example of potential applica- tions, the generated nearly diffraction-limited green light is used for pumping a Ti:sapphire laser...

  20. Spontaneous Charge Generation in Flowing Albumin Solutions at 35 °C and 38 °C

    Directory of Open Access Journals (Sweden)

    Yuri D. Ivanov

    2017-12-01

    Full Text Available The time dependence of a charge accumulation in a 10−15 M albumin solution, flowing through a measuring cell of an analytical flow system injector, had a nonlinear character under certain conditions, within a human physiological temperature range. Sharp charge increases depended on albumin concentration. This effect must be taken into consideration when generating models that describe electrokinetic phenomena in flowing protein solutions and when developing analytical flow systems for the registration of biomolecules in low concentration ranges.

  1. Generating the Nighttime Light of the Human Settlements by Identifying Periodic Components from DMSP/OLS Satellite Imagery.

    Science.gov (United States)

    Letu, Husi; Hara, Masanao; Tana, Gegen; Bao, Yuhai; Nishio, Fumihiko

    2015-09-01

    Nighttime lights of the human settlements (hereafter, "stable lights") are seen as a valuable proxy of social economic activity and greenhouse gas emissions at the subnational level. In this study, we propose an improved method to generate the stable lights from Defense Meteorological Satellite Program/Operational Linescan System (DMSP/OLS) daily nighttime light data for 1999. The study area includes Japan, China, India, and other 10 countries in East Asia. A noise reduction filter (NRF) was employed to generate a stable light from DMSP/OLS time-series daily nighttime light data. It was found that noise from amplitude of the 1-year periodic component is included in the stable light. To remove the amplitude of the 1-year periodic component noise included in the stable light, the NRF method was improved to extract the periodic component. Then, new stable light was generated by removing the amplitude of the 1-year periodic component using the improved NRF method. The resulting stable light was evaluated by comparing it with the conventional nighttime stable light provided by the National Oceanic and Atmosphere Administration/National Geophysical Data Center (NOAA/NGDC). It is indicated that DNs of the NOAA stable light image are lower than those of the new stable light image. This might be attributable to the influence of attenuation effects from thin warm water clouds. However, due to overglow effect of the thin cloud, light area in new stable light is larger than NOAA stable light. Furthermore, the cumulative digital numbers (CDNs) and number of light area pixels (NLAP) of the generated stable light and NOAA/NGDC stable light were applied to estimate socioeconomic variables of population, electric power consumption, gross domestic product, and CO2 emissions from fossil fuel consumption. It is shown that the correlations of the population and CO2FF with new stable light data are higher than those in NOAA stable light data; correlations of the EPC and GDP with NOAA

  2. 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...

  3. Generation of human bispecific common light chain antibodies by combining animal immunization and yeast display.

    Science.gov (United States)

    Krah, Simon; Schröter, Christian; Eller, Carla; Rhiel, Laura; Rasche, Nicolas; Beck, Jan; Sellmann, Carolin; Günther, Ralf; Toleikis, Lars; Hock, Björn; Kolmar, Harald; Becker, Stefan

    2017-04-01

    Bispecific antibodies (bsAbs) pave the way for novel therapeutic modes of action along with potential benefits in several clinical applications. However, their generation remains challenging due to the necessity of correct pairings of two different heavy and light chains and related manufacturability issues. We describe a generic approach for the generation of fully human IgG-like bsAbs. For this, heavy chain repertoires from immunized transgenic rats were combined with either a randomly chosen common light chain or a light chain of an existing therapeutic antibody and screened for binders against tumor-related targets CEACAM5 and CEACAM6 by yeast surface display. bsAbs with subnanomolar affinities were identified, wherein each separate binding arm mediated specific binding to the respective antigen. Altogether, the described strategy represents a combination of in vivo immunization with an in vitro selection method, which allows for the integration of existing therapeutic antibodies into a bispecific format. © The Author 2017. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  4. SESAME-A 3rd Generation Synchrotron Light Source for the Middle East

    Science.gov (United States)

    Winick, Herman

    2010-02-01

    Developed under the auspices of UNESCO and modeled on CERN, SESAME (Synchrotron-light for Experimental Science and Applications in the Middle East) is an international research center in construction in Jordan. It will enable world class research by scientists from the region, reversing the brain drain. It will also build bridges between diverse societies, contributing to a culture of peace through international cooperation in science. The centerpiece is a synchrotron light source originating from BESSY I, a gift by Germany. The upgraded machine, a 2.5 GeV 3rd Generation Light Source (133m circumference, 26nm-rad emittance and 12 places for insertion devices), will provide light from infra-red to hard X-rays, offering excellent opportunities to train local scientists and attract those working abroad to return. The SESAME Council meets twice each year and presently has nine Members (Bahrain, Cyprus, Egypt, Iran, Israel, Jordan, Pakistan, Palestinian Authority, Turkey). Members have responsibility for the project and provide the annual operations budget (1.5M US dollars in 2009, expected to rise to about 5M when operation starts in 2012-13). Jordan provided the site, building, and infrastructure. A staff of 20 is installing the 0.8 GeV BESSY I injection system. The facility will have the capacity to serve 30 or more experiments operating simultaneously. See www.sesame.org.jo )

  5. White light generation using Förster resonance energy transfer between 3-hydroxyisoquinoline and Nile Red.

    Science.gov (United States)

    Joshi, Neeraj K; Polgar, Alexander M; Steer, Ronald P; Paige, Matthew F

    2016-05-11

    Simple composite films consisting of a polymer blended with organic emitters have the potential for broad-band "white" light emission that can be used for general lighting applications. In the present work, a simple mixture of 3-hydroxyisoquinoline (HIQ) with Nile Red (NR) in a polymeric matrix of polyvinyl alcohol (PVA) is used to generate white light through a non-radiative excitation energy transfer (NREET) mechanism. NREET between HIQ and NR doped in PVA films is investigated using a combination of steady state and time resolved fluorescence spectroscopic methods. It is observed that NR has very weak fluorescence in the PVA film upon excitation at 400 nm, but upon mixing NR with HIQ, sensitized emission of NR is observed with decreased emission of HIQ. The behavior of the sensitized emission of NR is consistent with Förster resonance energy transfer (FRET) between the donor HIQ and acceptor NR. By adjusting the relative fractions of HIQ and NR in the films, the extent of FRET could be regulated and the overall film emission color could be manipulated to enable overall "white" (CIE color coordinates 0.34, 0.38) emission. The films showed excellent photostability with 405 nm diode illumination, along with mechanical flexibility, suggesting good potential utility as a down converting element for lighting applications.

  6. Probing Cherenkov and Scintillation Light Separation for Next-Generation Neutrino Detectors

    Science.gov (United States)

    Caravaca, J.; Descamps, F. B.; Land, B. J.; Orebi Gann, G. D.; Wallig, J.; Yeh, M.

    2017-09-01

    The ability to separate Cherenkov and scintillation signals in liquid scintillator detectors would enable outstanding background rejection for next-generation neutrino experiments. Reconstruction of directional information, ring imaging, and sub-Cherenkov threshold detection all have the potential to substantially improve particle and event identification. The Cherenkov-Scintillation Separation (CHESS) experiment uses an array of small, fast photomultipliers (PMTs) and state-of-the-art electronics to demonstrate the reconstruction of a Cherenkov ring in a scintillation medium based on photon hit times and detected charge. This setup has been used to characterize the ability to detect Cherenkov light in a range of target media. We show results with pure organic scintillator (LAB) and the prospects with scintillators with a secondary fluor (LAB/PPO). There are future plans to deploy the newly developed water-based liquid scintillator, a medium with a higher Cherenkov/Scintillation light yield ratio than conventional pure liquid scintillators, enhancing the visibility of the less abundant Cherenkov light in the presence of scintillation light. These results can inform the development of future large-scale detectors, such as the proposed Theia experiment, or other large detectors at underground laboratories such as the far-site of the new Long Baseline Neutrino Facility at the Sanford Underground Research Facility. CHESS detector calibrations and commissioning will be discussed, and the latest results will be presented.

  7. 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...

  8. Large diameter permanent-magnets-expanded plasma source for spontaneous generation of low-energy ion beam.

    Science.gov (United States)

    Takahashi, Kazunori; Suzuki, Tatsuya; Ando, Akira

    2014-02-01

    Diameter of a permanent-magnets-expanded, radiofrequency (rf) plasma source is enlarged up to ∼13 cm for an application to a space propulsion device and tested with being attached to a diffusion chamber. The source is operated at 13.56 MHz 300 W rf power in low-pressure (40 mPa) argon. Measurement of ion energy distribution functions downstream of the source exit shows generation of a supersonic ion beam of about 20 eV. The detailed radial measurements demonstrate that the diameter and energy of the ion beam corresponds to the source tube diameter and the potential difference between the source and downstream plasmas, and that the radial profile of the beam flux is similar to the plasma density profile in the source cavity.

  9. Long Wavelength Electromagnetic Light Bullets Generated by a 10.6 micron CO2 Ultrashort Pulsed Source

    Science.gov (United States)

    2016-11-29

    AFRL-AFOSR-VA-TR-2016-0365 Long Wavelength Electromagnetic Light Bullets Generated by a 10.6 micron CO2 Ultrashort Pulsed Source Jerome Moloney...SUBTITLE "Long Wavelength Electromagnetic Light Bullets Generated by a 10.6 micron CO2 Ultrashort Pulsed Source 5a. CONTRACT NUMBER FA9550-15-1-0272 5b...Wavelength Electromagnetic Light Bullets Generated by a 10 µm CO2 Ultrashort Pulsed Source Grant/Contract Number AFOSR assigned control number. It must

  10. Experimental generation of non-Kolmogorov turbulence using a liquid crystal spatial light modulator

    Science.gov (United States)

    Toselli, Italo; Agrawal, Brij N.; Wilcox, Christopher C.; Restaino, Sergio

    2011-09-01

    Several experiments showed that the classical Kolmogorov power spectral density of the refractive-index sometimes does not properly describe the statistics of the atmosphere. In this paper we show an experimental testbed able to generate non-classical Kolmogorov turbulence by using a liquid crystal spatial light modulator. The testbed is used at Naval Postgraduate School for laboratory investigation of laser beam propagation in maritime environment where a power law different from classical Kolmogorov, 11/ 3, could be present. Applications of this testbed are ship to-ship free space optical communication, imaging and high energy laser weapons.

  11. The Advanced Light Source: A third-generation Synchrotron Radiation Source

    Energy Technology Data Exchange (ETDEWEB)

    Robinson, Arthur L.

    2002-08-14

    The Advanced Light Source (ALS) at the E.O. Lawrence Berkeley National Laboratory (Berkeley Lab) of the University of California is a ''third-generation'' synchrotron radiation source optimized for highest brightness at ultraviolet and soft x-ray photon energies. It also provides world-class performance at hard x-ray photon energies. Berkeley Lab operates the ALS for the United States Department of Energy as a national user facility that is available 24 hours/day around the year for research by scientists from industrial, academic, and government laboratories primarily from the United States but also from abroad.

  12. Compact solar autoclave based on steam generation using broadband light-harvesting nanoparticles.

    Science.gov (United States)

    Neumann, Oara; Feronti, Curtis; Neumann, Albert D; Dong, Anjie; Schell, Kevin; Lu, Benjamin; Kim, Eric; Quinn, Mary; Thompson, Shea; Grady, Nathaniel; Nordlander, Peter; Oden, Maria; Halas, Naomi J

    2013-07-16

    The lack of readily available sterilization processes for medicine and dentistry practices in the developing world is a major risk factor for the propagation of disease. Modern medical facilities in the developed world often use autoclave systems to sterilize medical instruments and equipment and process waste that could contain harmful contagions. Here, we show the use of broadband light-absorbing nanoparticles as solar photothermal heaters, which generate high-temperature steam for a standalone, efficient solar autoclave useful for sanitation of instruments or materials in resource-limited, remote locations. Sterilization was verified using a standard Geobacillus stearothermophilus-based biological indicator.

  13. Simulation of light generation in cholesteric liquid crystals using kinetic equations: Time-independent solution

    Energy Technology Data Exchange (ETDEWEB)

    Shtykov, N. M., E-mail: nshtykov@mail.ru; Palto, S. P.; Umanskii, B. A. [Russian Academy of Sciences, Shubnikov Institute of Crystallography (Russian Federation)

    2013-08-15

    We report on the results of calculating the conditions for light generation in cholesteric liquid crystals doped with fluorescent dyes using kinetic equations. Specific features of spectral properties of the chiral cholesteric medium as a photonic structure and spatially distributed type of the feedback in the active medium are taken into account. The expression is derived for the threshold pump radiation intensity as a function of the dye concentration and sample thickness. The importance of taking into account the distributed loss level in the active medium for calculating the optimal parameters of the medium and for matching the calculated values with the results of experiments is demonstrated.

  14. Ebastine in the light of CONGA recommendations for the development of third-generation antihistamines

    Directory of Open Access Journals (Sweden)

    S Rico

    2009-08-01

    Full Text Available S Rico1,2, RM Antonijoan1,3, MJ Barbanoj1,2,31Centre d’lnvestigació de Medicaments, Institut de Recerca; Servei de Farmacologia Clínica, Hospital de la Santa Creu i Sant Pau, Barcelona, Spain; 2Departament de Farmacologia i Terapèutica, Universitat Autònoma de Barcelona, Barcelona, Spain; 3Centro de investigación Biomédica en Red de Salud Mental CIBERSAM, SpainAbstract: In 2003 a consensus group on new-generation antihistamines (CONGA defined the characteristics required for a third-generation H1 antihistamine as there had been much controversy about this issue since the early 1990s. One of the antihistamines that had been claimed to belong to such a group is the second-generation antihistamine, ebastine. The objective of this review is to analyze the pharmacology of ebastine, in light of the CONGA recommendations for the development of new-generation antihistamines: (1 anti-inflammatory properties, (2 potency, efficacy and effectiveness, (3 lack of cardiotoxicity, (4 lack of drug interactions, (5 lack of CNS effects, and (6 pharmacological approach. Ebastine seems to have anti-inflammatory properties that help to ameliorate nasal congestion, though this has not yet been conclusively demonstrated. Its pharmacological–therapeutic profile does not differ greatly from that of other second-generation antihistamines. Its cardiac safety has been widely assessed and no cardiac toxicity has been found at therapeutic doses despite initial concerns. The risk of potentially relevant drug interactions has been investigated and ruled out. Ebastine does not produce sedation at therapeutic doses and drug interaction studies with classical CNS depressants have not demonstrated a synergistic effect. Pharmacologically, ebastine is an H1 inverse agonist. Perhaps the answer to the quest for new-generation antihistamines lies not only in H1 but in a combined approach with other histamine receptors.Keywords: ebastine, antihistamines, third-generation, CONGA

  15. Second-generation PVCC design with a dielectric light injector and polyhedron interior cavity

    Science.gov (United States)

    Ortabasi, Ugur; Winston, Roland; Ellis, Scott

    2006-08-01

    The Photovoltaic Cavity Converter (PVCC) under development is a novel approach to convert highly concentrated solar radiation into electricity via a photon entrapment process and subsequent spectral stripping. Equipped with a multi-bandgap, single junction cell system PVCC circumvents most of the present limitations of the four (or more)-junction cell systems with vertical architecture. Our previous studies have shown that the PVCC concept has the potential to reach a collective conversion efficiency of 50% in the near term. Based on our past experiences regarding the cavity geometry and the light injection method we have developed a second generation design for the PVCC that overcomes the limitations of the first generation prototype.

  16. Highly efficient tandem organic light-emitting devices employing an easily fabricated charge generation unit

    Science.gov (United States)

    Yang, Huishan; Yu, Yaoyao; Wu, Lishuang; Qu, Biao; Lin, Wenyan; Yu, Ye; Wu, Zhijun; Xie, Wenfa

    2018-02-01

    We have realized highly efficient tandem organic light-emitting devices (OLEDs) employing an easily fabricated charge generation unit (CGU) combining 1,4,5,8,9,11-hexaazatriphenylene-hexacarbonitrile with ultrathin bilayers of CsN3 and Al. The charge generation and separation processes of the CGU have been demonstrated by studying the differences in the current density–voltage characteristics of external-carrier-excluding devices. At high luminances of 1000 and 10000 cd/m2, the current efficiencies of the phosphorescent tandem device are about 2.2- and 2.3-fold those of the corresponding single-unit device, respectively. Simultaneously, an efficient tandem white OLED exhibiting high color stability and warm white emission has also been fabricated.

  17. PANI/NaTaO3 composite photocatalyst for enhanced hydrogen generation under UV light irradiation

    Directory of Open Access Journals (Sweden)

    Zielińska Beata

    2017-09-01

    Full Text Available A PANI/NaTaO3 composite was successfully synthesized by an oxidative polymerization of aniline monomer in hydrochloric acid solution containing sodium tantalate. NaTaO3 at a monoclinic structure was produced via hydrothermal method. The photocatalytic activities of the unmodified NaTaO3 and PANI/NaTaO3 were evaluated for hydrogen generation from an aqueous HCOOH solution and under UV light irradiation. The results showed that the evolution rate of H2 increased significantly when NaTaO3 was modified with PANI. The enhancement of the photocatalytic activity of PANI/NaTaO3 composite was ascribed to the effective charge transfer and separation between NaTaO3 and PANI, which reduced their recombination. This indicates that PANI modification of tantalate photocatalysts may open up a new way to prepare highly efficient catalytic materials for H2 generation.

  18. Single-frequency blue light generation by single-pass sum-frequency generation in a coupled ring cavity tapered laser

    DEFF Research Database (Denmark)

    Jensen, Ole Bjarlin; Petersen, Paul Michael

    2013-01-01

    A generic approach for generation of tunable single frequency light is presented. 340 mW of near diffraction limited, single-frequency, and tunable blue light around 459 nm is generated by sum-frequency generation (SFG) between two tunable tapered diode lasers. One diode laser is operated in a ring...... cavity and another tapered diode laser is single-passed through a nonlinear crystal which is contained in the coupled ring cavity. Using this method, the single-pass conversion efficiency is more than 25%. In contrast to SFG in an external cavity, the system is entirely self-stabilized with no electronic...

  19. Gastric Tissue Damage Analysis Generated by Ischemia: Bioimpedance, Confocal Endomicroscopy, and Light Microscopy

    Directory of Open Access Journals (Sweden)

    Nohra E. Beltran

    2013-01-01

    Full Text Available The gastric mucosa ischemic tissular damage plays an important role in critical care patients’ outcome, because it is the first damaged tissue by compensatory mechanism during shock. The aim of the study is to relate bioimpedance changes with tissular damage level generated by ischemia by means of confocal endomicroscopy and light microscopy. Bioimpedance of the gastric mucosa and confocal images were obtained from Wistar male rats during basal and ischemia conditions. They were anesthetized, and stain was applied (fluorescein and/or acriflavine. The impedance spectroscopy catheter was inserted and then confocal endomicroscopy probe. After basal measurements and biopsy, hepatic and gastric arteries clamping induced ischemia. Finally, pyloric antrum tissue was preserved in buffered formaldehyde (10% for histology processing using light microscopy. Confocal images were equalized, binarized, and boundary defined, and infiltrations were quantified. Impedance and infiltrations increased with ischemia showing significant changes between basal and ischemia conditions (. Light microscopy analysis allows detection of general alterations in cellular and tissular integrity, confirming gastric reactance and confocal images quantification increments obtained during ischemia.

  20. Design of segmented thermoelectric generator based on cost-effective and light-weight thermoelectric alloys

    International Nuclear Information System (INIS)

    Kim, Hee Seok; Kikuchi, Keiko; Itoh, Takashi; Iida, Tsutomu; Taya, Minoru

    2014-01-01

    Highlights: • Segmented thermoelectric (TE) module operating at 500 °C for combustion engine system. • Si based light-weight TE generator increases the specific power density [W/kg]. • Study of contact resistance at the bonding interfaces maximizing output power. • Accurate agreement of the theoretical predictions with experimental results. - Abstract: A segmented thermoelectric (TE) generator was designed with higher temperature segments composed of n-type Mg 2 Si and p-type higher manganese silicide (HMS) and lower temperature segments composed of n- and p-type Bi–Te based compounds. Since magnesium and silicon based TE alloys have low densities, they produce a TE module with a high specific power density that is suitable for airborne applications. A two-pair segmented π-shaped TE generator was assembled with low contact resistance materials across bonding interfaces. The peak specific power density of this generator was measured at 42.9 W/kg under a 498 °C temperature difference, which has a good agreement with analytical predictions

  1. Spontaneous deregulation

    NARCIS (Netherlands)

    Edelman, Benjamin; Geradin, Damien

    Platform businesses such as Airbnb and Uber have risen to success partly by sidestepping laws and regulations that encumber their traditional competitors. Such rule flouting is what the authors call “spontaneous private deregulation,” and it’s happening in a growing number of industries. The authors

  2. Influence of generator structure on pinch reflex diode operation for light ion production

    International Nuclear Information System (INIS)

    Bernard, A.; Bourgeois, C.; Camarcat, N.; Tournier, B.

    1983-01-01

    Light ion beams with characteristics 1 MV, 185 kA, 100 ns FWHM have been accelerated in a pinch-reflex diode driven by the SIDONIX II generator pulsed in positive polarity. The diode impedance of 2 ohms remains higher than the water line impedance of 1.3 ohms, and consequently, the ion efficiency is limited to 25%. This effect is attributed to the slow current rise time and fast anode plasma expansion since the machine does not have an intermediate store to reduce the 100 ns FWHM power pulse. Published data on Hydra, Reiden IV, Gamble II A support this hypothesis. Preliminary results of focusing experiments, when the beam is injected into a 1 Torr air cell downstream the cathode, indicate that 60 kA end up on a 3 cm diameter target. These results should be improved by adding an intermediate store to the generator, giving a 1.3 TW, 45 ns FWHM power pulse for 180 kJ of stored energy in the Marx. We expect that the increase in diode electrical power will lead to an increase in total ion current. For GAMBLE II A, 500 kA of light ion are extracted when the diode power reaches 1.4 TW, for equivalent Marx energies

  3. [Study of exciton generation region of phosphorescent light emitting devices based on the changing electric field].

    Science.gov (United States)

    Liu, Xu-dong; Zhao, Su-ling; Song, Dan-dan; Zhan, Hong-ming; Yuan, Guang-cai; Xu, Zheng

    2009-09-01

    The changes of exciton generation region are influenced by varying electric field, which affect the color and efficiency performance of devices. Firstly, The authors fabricated two types of phosphorescent light emitting devices, device 1:ITO/PEDOT : PSS/PVK : Ir(ppy)s : DCJTB (100:2:1 wt)/BCP(10 nm)/Alq3 (15 nm)/Al, and device 2: ITO/PEDOT : PSS/ PVK : Ir(ppy)3 (100:2 wt)/BCP (10 nm)/Alq3(15 nm)/Al. The authors investigated the influences of electric field on exciton generation region in single-layer and multi-doped structure devices. Analysis of the electroluminescence spectrum under different voltages indicates that the emitting of Ir(ppy)3, PVK and DCJTB was enhanced with the increase in applied voltages. Compared to Ir(ppy)3, the emitting of PVK and DCJTB was prominently enhanced. This is because under high electric field it is easier high energy carrier to generate high energy exciton, and the emitting of wide-band-gap material PVK is stronger; on the other hand, the authors investigated the results from the aspect of energy band gap. DCJTB is narrow-band-gap material, which can capture carrier comparatively easily and emit stronger light. At the same time, we obtained a new emission peak located at 460 nm, which becomes comparatively weak with increasing voltage. In order to explore the reason, we fabricated the device: ITO/ PEDOT: PSS/PVK : BCP : Ir(ppy)3 (x:y:2 wt)/Alq3 (15 nm)/Al. The 460 nm emission peak doesn't disappear by changing the mass ratio of x and y. The authors speculate that the emission peak relates to PVK and BCP.

  4. Generating picosecond x-ray pulses in synchrotron light sources using dipole kickers

    Directory of Open Access Journals (Sweden)

    W. Guo

    2007-02-01

    Full Text Available The duration of the x-ray pulse generated at a synchrotron light source is typically tens of picoseconds. Shorter pulses are highly desired by the users. In electron storage rings, the vertical beam size is usually orders of magnitude less than the bunch length due to radiation damping; therefore, a shorter pulse can be obtained by slitting the vertically tilted bunch. Zholents proposed tilting the bunch using rf deflection. We found that tilted bunches can also be generated by a dipole magnet kick. A vertical tilt is developed after the kick in the presence of nonzero chromaticity. The tilt was successfully observed and a 4.2-ps pulse was obtained from a 27-ps electron bunch at the Advanced Photon Source. Based on this principle, we propose a short-pulse generation scheme that produces picosecond x-ray pulses at a repetition rate of 1–2 kHz, which can be used for pump-probe experiments.

  5. Technique for the comparison of light spectra from natural and laboratory generated lightning current arcs

    Science.gov (United States)

    Mitchard, D.; Clark, D.; Carr, D.; Haddad, A.

    2016-08-01

    A technique was developed for the comparison of observed emission spectra from lightning current arcs generated through self-breakdown in air and the use of two types of initiation wire, aluminum bronze and nichrome, against previously published spectra of natural lightning events. A spectrograph system was used in which the wavelength of light emitted by the lightning arc was analyzed to derive elemental interactions. A lightning impulse of up to 100 kA was applied to a two hemispherical tungsten electrode configuration which allowed the effect of the lightning current and lightning arc length to be investigated. A natural lightning reference spectrum was reconstructed from literature, and generated lightning spectra were obtained from self-breakdown across a 14.0 mm air gap and triggered along initiation wires of length up to 72.4 mm. A comparison of the spectra showed that the generated lightning arc induced via self-breakdown produced a very similar spectrum to that of natural lightning, with the addition of only a few lines from the tungsten electrodes. A comparison of the results from the aluminum bronze initiation wire showed several more lines, whereas results from the nichrome initiation wire differed greatly across large parts of the spectrum. This work highlights the potential use for spectrographic techniques in the study of lightning interactions with surrounding media and materials, and in natural phenomena such as recently observed ball lightning.

  6. Technique for the comparison of light spectra from natural and laboratory generated lightning current arcs

    Energy Technology Data Exchange (ETDEWEB)

    Mitchard, D., E-mail: mitcharddr@cardiff.ac.uk; Clark, D.; Carr, D.; Haddad, A. [Morgan-Botti Lightning Laboratory, Advanced High Voltage Research Centre, School of Engineering, Cardiff University, CF24 3AA Wales (United Kingdom)

    2016-08-29

    A technique was developed for the comparison of observed emission spectra from lightning current arcs generated through self-breakdown in air and the use of two types of initiation wire, aluminum bronze and nichrome, against previously published spectra of natural lightning events. A spectrograph system was used in which the wavelength of light emitted by the lightning arc was analyzed to derive elemental interactions. A lightning impulse of up to 100 kA was applied to a two hemispherical tungsten electrode configuration which allowed the effect of the lightning current and lightning arc length to be investigated. A natural lightning reference spectrum was reconstructed from literature, and generated lightning spectra were obtained from self-breakdown across a 14.0 mm air gap and triggered along initiation wires of length up to 72.4 mm. A comparison of the spectra showed that the generated lightning arc induced via self-breakdown produced a very similar spectrum to that of natural lightning, with the addition of only a few lines from the tungsten electrodes. A comparison of the results from the aluminum bronze initiation wire showed several more lines, whereas results from the nichrome initiation wire differed greatly across large parts of the spectrum. This work highlights the potential use for spectrographic techniques in the study of lightning interactions with surrounding media and materials, and in natural phenomena such as recently observed ball lightning.

  7. Interactive Light Stimulus Generation with High Performance Real-Time Image Processing and Simple Scripting

    Directory of Open Access Journals (Sweden)

    László Szécsi

    2017-12-01

    Full Text Available Light stimulation with precise and complex spatial and temporal modulation is demanded by a series of research fields like visual neuroscience, optogenetics, ophthalmology, and visual psychophysics. We developed a user-friendly and flexible stimulus generating framework (GEARS GPU-based Eye And Retina Stimulation Software, which offers access to GPU computing power, and allows interactive modification of stimulus parameters during experiments. Furthermore, it has built-in support for driving external equipment, as well as for synchronization tasks, via USB ports. The use of GEARS does not require elaborate programming skills. The necessary scripting is visually aided by an intuitive interface, while the details of the underlying software and hardware components remain hidden. Internally, the software is a C++/Python hybrid using OpenGL graphics. Computations are performed on the GPU, and are defined in the GLSL shading language. However, all GPU settings, including the GPU shader programs, are automatically generated by GEARS. This is configured through a method encountered in game programming, which allows high flexibility: stimuli are straightforwardly composed using a broad library of basic components. Stimulus rendering is implemented solely in C++, therefore intermediary libraries for interfacing could be omitted. This enables the program to perform computationally demanding tasks like en-masse random number generation or real-time image processing by local and global operations.

  8. Enhancement and electric charge-assisted tuning of nonlinear light generation in bipolar plasmonics.

    Science.gov (United States)

    Ding, Wei; Zhou, Liangcheng; Chou, Stephen Y

    2014-05-14

    We propose and experimentally demonstrate a new plasmonic nonlinear light generation (NLG) structure, termed plasmonic-enhanced, charge-assisted second-harmonic generator (p-CASH), that not only achieves high second-harmonic generation (SHG) enhancement (76-fold), large SHG tunability by bias (8%/V), wide tuning range (280%), 7.8 × 10(-9) conversion efficiency, and high stability but also exhibits a SHG tuning, that is bipolar rather than unipolar, not due to the third-order nonlinear polarization term, hence fundamentally different from the classic electric field induced SHG-tuning (EFISH). We propose a new SHG tuning mechanism: the second-order nonlinear polarization term enhanced by plasmonic effects, changed by charge injection and negative oxygen vacancies movement, and is nearly 3 orders of magnitude larger than EFISH. p-CASH is a bipolar parallel-plate capacitor with thin layers of plasmonic nanostructures, a TiOx (semiconductor and nonlinear) and a SiO2 (insulator) sandwiched between two electrodes. Fabrication of p-CASH used nanoimprint on 4″ wafer and is scalable to wallpaper-sized areas. The new structure, new properties, and new understanding should open up various new designs and applications of NLG in various fields.

  9. Efficient green phosphorescent tandem organic light emitting diodes with solution processable mixed hosts charge generating layer

    Energy Technology Data Exchange (ETDEWEB)

    Talik, N.A.; Yeoh, K.H.; Ng, C.Y.B [Low Dimensional Research Center, Department of Physics, University Malaya, 50603 Kuala Lumpur (Malaysia); ItraMAS Corporation. Sdn. Bhd., 542A-B Mukim 1, Lorong Perusahaan Baru 2, Kawasan Perindustrian, Perai 13600, Penang (Malaysia); Yap, B.K. [Center of Microelectronic and Nanotechnology Engineering (CeMNE), College of Engineering, Universiti Tenaga Nasional, Jln. Uniten-Ikram, 4300 Kajang, Selangor (Malaysia); Woon, K.L., E-mail: ph7klw76@um.edu.my [Low Dimensional Research Center, Department of Physics, University Malaya, 50603 Kuala Lumpur (Malaysia)

    2014-10-15

    A novel solution processable charge generating layer (CGL) that consists of 1,4,5,8,9,11-hexaazatriphenylene hexacarbonitrile (HATCN{sub 6})/Poly(N-vinylcarbazole) (PVK): 1,1-bis-(4-bis(4-tolyl)-aminophenyl) cyclohexene (TAPC) for a tandem green phosphorescent organic light emitting diode (PHOLED) is demonstrated. The use of orthogonal solvent to dissolve HATCN{sub 6} and PVK:TAPC is the key to overcome the interface erosion problem for the solution processed CGL. The current efficiency of the 2 wt% TAPC mixed with PVK is the highest at 24.2 cd/A, which is more than three-folds higher than that of the single device at 1000 cd/m{sup 2}. - Highlights: • A solution processable tandem OLED is built using a novel charge generating layer. • HATCN{sub 6} and PVK:TAPC are shown to be effective charge generating layers. • The turn on voltages for tandem devices are almost similar to single unit. • 2 wt% TAPC blended with PVK exhibits three-folds increase in efficiency.

  10. SESAME — A 3rd Generation Synchrotron Light Source for the Middle East

    Science.gov (United States)

    Å°lkü, Dinçer; Rahighi, Javad; Winick, Herman

    2007-01-01

    SESAME (Synchrotron-light for Experimental Science and Applications in the Middle East) will be the Middle East's first international research center. It is a cooperative venture by the scientists and governments of the region with founding members Bahrain, Egypt, Israel, Jordan, Pakistan, Palestine Authority, and Turkey. Iran is in the process of finalizing its formal membership. Other countries (Cyprus, Morocco, and the United Arab Emirates) are also expected to join. The permanent Council of member states has full responsibility for the project. Members provide the annual operating budget. Observer countries are Germany, Greece, Italy, Kuwait, Portugal, Russian Federation, Sweden, the UK, and the US. SESAME is being developed under the umbrella of UNESCO. Jordan was selected as the building site. SESAME will offer excellent opportunities for training of Middle East scientists and attract those working abroad to consider returning. SESAME will be a 2.5GeV 3rd Generation light source (emittance 26nm-rad, circumference ˜133m), providing excellent performance for structural molecular biology, molecular environmental science, surface and interface science, microelectromechanical devices, x-ray imaging, archaeological microanalysis, and materials characterization. It will cover a broad spectral range from the infrared to hard x-rays and will have 12 straight sections for insertion devices (average length 2.75m). The injector will be the BESSY I 0.8 GeV booster synchrotron which has been given as a gift from Germany. Four committees advise the Council and assist in developing the technical design, beam lines, user community, and scientific Program. The SESAME building, now in construction with funds and a site provided by Jordan, is scheduled for completion in late 2006 after which the BESSY I injector will be installed. First stored beam in the new 2.5 GeV ring is planned for 2009 with six initial beamlines planned. Some beamlines will be built by member countries

  11. SESAME - A 3rd Generation Synchrotron Light Source for the Middle East

    International Nuclear Information System (INIS)

    Ulkue, Dincer; Rahighi, Javad; Winick, Herman

    2007-01-01

    SESAME (Synchrotron-light for Experimental Science and Applications in the Middle East) will be the Middle East's first international research center. It is a cooperative venture by the scientists and governments of the region with founding members Bahrain, Egypt, Israel, Jordan, Pakistan, Palestine Authority, and Turkey. Iran is in the process of finalizing its formal membership. Other countries (Cyprus, Morocco, and the United Arab Emirates) are also expected to join. The permanent Council of member states has full responsibility for the project. Members provide the annual operating budget. Observer countries are Germany, Greece, Italy, Kuwait, Portugal, Russian Federation, Sweden, the UK, and the US. SESAME is being developed under the umbrella of UNESCO. Jordan was selected as the building site. SESAME will offer excellent opportunities for training of Middle East scientists and attract those working abroad to consider returning. SESAME will be a 2.5GeV 3rd Generation light source (emittance 26nm-rad, circumference ∼133m), providing excellent performance for structural molecular biology, molecular environmental science, surface and interface science, microelectromechanical devices, x-ray imaging, archaeological microanalysis, and materials characterization. It will cover a broad spectral range from the infrared to hard x-rays and will have 12 straight sections for insertion devices (average length 2.75m). The injector will be the BESSY I 0.8 GeV booster synchrotron which has been given as a gift from Germany. Four committees advise the Council and assist in developing the technical design, beam lines, user community, and scientific Program. The SESAME building, now in construction with funds and a site provided by Jordan, is scheduled for completion in late 2006 after which the BESSY I injector will be installed. First stored beam in the new 2.5 GeV ring is planned for 2009 with six initial beamlines planned. Some beamlines will be built by member countries

  12. SESAME - A 3rd Generation Synchrotron Light Source for the Middle East

    Science.gov (United States)

    U˝Lkü, Dinçer; Rahighi, Javad; Winick, Herman

    2007-01-01

    SESAME (Synchrotron-light for Experimental Science and Applications in the Middle East) will be the Middle East's first international research center. It is a cooperative venture by the scientists and governments of the region with founding members Bahrain, Egypt, Israel, Jordan, Pakistan, Palestine Authority, and Turkey. Iran is in the process of finalizing its formal membership. Other countries (Cyprus, Morocco, and the United Arab Emirates) are also expected to join. The permanent Council of member states has full responsibility for the project. Members provide the annual operating budget. Observer countries are Germany, Greece, Italy, Kuwait, Portugal, Russian Federation, Sweden, the UK, and the US. SESAME is being developed under the umbrella of UNESCO. Jordan was selected as the building site. SESAME will offer excellent opportunities for training of Middle East scientists and attract those working abroad to consider returning. SESAME will be a 2.5GeV 3rd Generation light source (emittance 26nm-rad, circumference ~133m), providing excellent performance for structural molecular biology, molecular environmental science, surface and interface science, microelectromechanical devices, x-ray imaging, archaeological microanalysis, and materials characterization. It will cover a broad spectral range from the infrared to hard x-rays and will have 12 straight sections for insertion devices (average length 2.75m). The injector will be the BESSY I 0.8 GeV booster synchrotron which has been given as a gift from Germany. Four committees advise the Council and assist in developing the technical design, beam lines, user community, and scientific Program. The SESAME building, now in construction with funds and a site provided by Jordan, is scheduled for completion in late 2006 after which the BESSY I injector will be installed. First stored beam in the new 2.5 GeV ring is planned for 2009 with six initial beamlines planned. Some beamlines will be built by member countries

  13. Review of single particle dynamics for third generation light sources through frequency map analysis

    Directory of Open Access Journals (Sweden)

    L. Nadolski

    2003-11-01

    Full Text Available Frequency map analysis [J. Laskar, Icarus 88, 266 (1990] is used here to analyze the transverse dynamics of four third generation synchrotron light sources: the ALS, the ESRF, the SOLEIL project, and Super-ACO. Time variations of the betatron tunes give additional information for the global dynamics of the beam. The main resonances are revealed; a one-to-one correspondence between the configuration space and the frequency space can be performed. We stress that the frequency maps, and therefore the dynamics optimization, are highly sensitive to sextupolar strengths and vary in a large amount from one machine to another. The frequency maps can thus be used to characterize the different machines.

  14. Charge generation layers for solution processed tandem organic light emitting diodes with regular device architecture.

    Science.gov (United States)

    Höfle, Stefan; Bernhard, Christoph; Bruns, Michael; Kübel, Christian; Scherer, Torsten; Lemmer, Uli; Colsmann, Alexander

    2015-04-22

    Tandem organic light emitting diodes (OLEDs) utilizing fluorescent polymers in both sub-OLEDs and a regular device architecture were fabricated from solution, and their structure and performance characterized. The charge carrier generation layer comprised a zinc oxide layer, modified by a polyethylenimine interface dipole, for electron injection and either MoO3, WO3, or VOx for hole injection into the adjacent sub-OLEDs. ToF-SIMS investigations and STEM-EDX mapping verified the distinct functional layers throughout the layer stack. At a given device current density, the current efficiencies of both sub-OLEDs add up to a maximum of 25 cd/A, indicating a properly working tandem OLED.

  15. Modernized Approach for Generating Reproducible Heterogeneity Using Transmitted-Light for Flow Visualization Experiments

    Science.gov (United States)

    Jones, A. A.; Holt, R. M.

    2017-12-01

    Image capturing in flow experiments has been used for fluid mechanics research since the early 1970s. Interactions of fluid flow between the vadose zone and permanent water table are of great interest because this zone is responsible for all recharge waters, pollutant transport and irrigation efficiency for agriculture. Griffith, et al. (2011) developed an approach where constructed reproducible "geologically realistic" sand configurations are deposited in sandfilled experimental chambers for light-transmitted flow visualization experiments. This method creates reproducible, reverse graded, layered (stratified) thin-slab sand chambers for point source experiments visualizing multiphase flow through porous media. Reverse-graded stratification of sand chambers mimic many naturally occurring sedimentary deposits. Sandfilled chambers use light as nonintrusive tools for measuring water saturation in two-dimensions (2-D). Homogeneous and heterogeneous sand configurations can be produced to visualize the complex physics of the unsaturated zone. The experimental procedure developed by Griffith, et al. (2011) was designed using now outdated and obsolete equipment. We have modernized this approach with new Parker Deadel linear actuator and programed projects/code for multiple configurations. We have also updated the Roper CCD software and image processing software with the latest in industry standards. Modernization of transmitted-light source, robotic equipment, redesigned experimental chambers, and newly developed analytical procedures have greatly reduced time and cost per experiment. We have verified the ability of the new equipment to generate reproducible heterogeneous sand-filled chambers and demonstrated the functionality of the new equipment and procedures by reproducing several gravity-driven fingering experiments conducted by Griffith (2008).

  16. Visible light carrier generation in co-doped epitaxial titanate films

    Energy Technology Data Exchange (ETDEWEB)

    Comes, Ryan B.; Smolin, Sergey Y.; Kaspar, Tiffany C.; Gao, Ran; Apgar, Brent A.; Martin, Lane W.; Bowden, Mark E.; Baxter, Jason; Chambers, Scott A.

    2015-03-02

    Perovskite titanates such as SrTiO3 (STO) exhibit a wide range of important functional properties, including high electron mobility, ferroelectricity—which may be valuable in photovoltaic applications—and excellent photocatalytic performance. The wide optical band gap of titanates limits their use in these applications, however, making them ill-suited for integration into solar energy harvesting technologies. Our recent work has shown that by doping STO with equal concentrations of La and Cr we can enhance visible light absorption in epitaxial thin films while avoiding any compensating defects. In this work, we explore the optical properties of photoexcited carriers in these films. Using spectroscopic ellipsometry, we show that the Cr3+ dopants, which produce electronic states immediately above the top of the O 2p valence band in STO reduce the direct band gap of the material from 3.75 eV to between 2.4 and 2.7 eV depending on doping levels. Transient reflectance measurements confirm that optically generated carriers have a recombination lifetime comparable to that of STO and are in agreement with the observations from ellipsometry. Finally, through photoelectrochemical yield measurements, we show that these co-doped films exhibit enhanced visible light photocatalysis when compared to pure STO.

  17. Visible light carrier generation in co-doped epitaxial titanate films

    Energy Technology Data Exchange (ETDEWEB)

    Comes, Ryan B., E-mail: ryan.comes@pnnl.gov; Kaspar, Tiffany C.; Chambers, Scott A. [Fundamental and Computational Sciences Directorate, Pacific Northwest National Laboratory, Richland, Washington 99354 (United States); Smolin, Sergey Y.; Baxter, Jason B. [Department of Chemical and Biological Engineering, Drexel University, Philadelphia, Pennsylvania 19104 (United States); Gao, Ran [Department of Materials Science and Engineering, University of California-Berkeley, Berkeley, California 94720 (United States); Apgar, Brent A. [Department of Materials Science and Engineering, University of California-Berkeley, Berkeley, California 94720 (United States); Department of Materials Science and Engineering, University of Illinois at Urbana-Champaign, Champaign, Illinois 61801 (United States); Martin, Lane W. [Department of Materials Science and Engineering, University of California-Berkeley, Berkeley, California 94720 (United States); Materials Science Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Bowden, Mark E. [Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland, Washington 99354 (United States)

    2015-03-02

    Perovskite titanates such as SrTiO{sub 3} (STO) exhibit a wide range of important functional properties, including ferroelectricity and excellent photocatalytic performance. The wide optical band gap of titanates limits their use in these applications; however, making them ill-suited for integration into solar energy harvesting technologies. Our recent work has shown that by doping STO with equal concentrations of La and Cr, we can enhance visible light absorption in epitaxial thin films while avoiding any compensating defects. In this work, we explore the optical properties of photoexcited carriers in these films. Using spectroscopic ellipsometry, we show that the Cr{sup 3+} dopants, which produce electronic states immediately above the top of the O 2p valence band in STO reduce the direct band gap of the material from 3.75 eV to 2.4–2.7 eV depending on doping levels. Transient reflectance spectroscopy measurements are in agreement with the observations from ellipsometry and confirm that optically generated carriers are present for longer than 2 ns. Finally, through photoelectrochemical methylene blue degradation measurements, we show that these co-doped films exhibit enhanced visible light photocatalysis when compared to pure STO.

  18. Double-channel vector spatial light modulator for generation of arbitrary complex vector beams.

    Science.gov (United States)

    Guo, Cheng-Shan; Rong, Zhen-Yu; Wang, Shu-Zhen

    2014-01-15

    We propose an approach for implementation of an arbitrary vector beam based on a vector spatial light modulator (VSLM), which is simply composed by a phase-only spatial light modulator (SLM) and a composed half-wave plate with checkerboard structure. In combination with a four-phase encoding algorithm, the VSLM can transform a linear polarized Gaussian beam or a plane wave into a vector beam with both arbitrary spatial polarization and complex amplitude distributions in two dimensions. It is demonstrated that the VSLM can directly transform pure phase values into two orthogonal polarized complex values with high-diffraction efficiency. Compared with the existing methods for generation of vector beams with SLMs, our approach is on-axis and common-path with simple structure and only involves the zero-order diffraction. The proposed structure is also easier to make an integration and design portable device since it abstains from using optical elements such as special gratings, prisms, and reflectors.

  19. Generating Hydrated Electrons for Chemical Syntheses by Using a Green Light-Emitting Diode (LED).

    Science.gov (United States)

    Naumann, Robert; Lehmann, Florian; Goez, Martin

    2018-01-22

    We present the first working system for accessing and utilizing laboratory-scale concentrations of hydrated electrons by photoredox catalysis with a green light-emitting diode (LED). Decisive are micellar compartmentalization and photon pooling in an intermediate that decays with second-order kinetics. The only consumable is the nontoxic and bioavailable vitamin C. A turnover number of 1380 shows the LED method to be on par with electron generation by high-power pulsed lasers, but at a fraction of the cost. The extreme reducing power of the electron and its long unquenched life as a ground-state species are synergistic. We demonstrate the applicability to the dechlorination, defluorination, and hydrogenation of compounds that are inert towards all other visible-light photoredox catalysts known to date. A comprehensive mechanistic investigation from microseconds to hours yields results of general validity for photoredox catalysis with photon pooling, allowing optimization and upscaling. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. PSFGAN: a generative adversarial network system for separating quasar point sources and host galaxy light

    Science.gov (United States)

    Stark, Dominic; Launet, Barthelemy; Schawinski, Kevin; Zhang, Ce; Koss, Michael; Turp, M. Dennis; Sartori, Lia F.; Zhang, Hantian; Chen, Yiru; Weigel, Anna K.

    2018-03-01

    The study of unobscured active galactic nuclei (AGN) and quasars depends on the reliable decomposition of the light from the AGN point source and the extended host galaxy light. The problem is typically approached using parametric fitting routines using separate models for the host galaxy and the point spread function (PSF). We present a new approach using a Generative Adversarial Network (GAN) trained on galaxy images. We test the method using Sloan Digital Sky Survey (SDSS) r-band images with artificial AGN point sources added which are then removed using the GAN and with parametric methods using GALFIT. When the AGN point source PS is more than twice as bright as the host galaxy, we find that our method, PSFGAN, can recover PS and host galaxy magnitudes with smaller systematic error and a lower average scatter (49%). PSFGAN is more tolerant to poor knowledge of the PSF than parametric methods. Our tests show that PSFGAN is robust against a broadening in the PSF width of ±50% if it is trained on multiple PSF's. We demonstrate that while a matched training set does improve performance, we can still subtract point sources using a PSFGAN trained on non-astronomical images. While initial training is computationally expensive, evaluating PSFGAN on data is more than 40 times faster than GALFIT fitting two components. Finally, PSFGAN it is more robust and easy to use than parametric methods as it requires no input parameters.

  1. Visible Light Photocatalysis for the Generation and Use of Reactive Azolyl and Polyfluoroaryl Intermediates.

    Science.gov (United States)

    Arora, Amandeep; Weaver, Jimmie D

    2016-10-18

    Photocatalysis offers several mechanistically unique pathways that are not rivaled by mainstream catalysis. Primarily, the ability to convert photochemical energy into single electron oxidation and reduction events provides a new dimension for chemists to consider when choosing how to activate a molecule or approach a complex synthesis. Since most organic molecules do not absorb light in the visible region, they are impervious to direct visible light photochemistry, which provides an opportunity for photocatalysis in which a visible light absorbing compound can serve as a mediator. In this Account, we discuss the consequences of catalyst mediated, photoinduced electron transfer to several classes of reducible arenes. While the bulk of the work discussed within this Account utilizes iridium-based photocatalysts, in principle the chemistry is not limited to this class of photocatalyst, and the principles should be more general. Instead, this Account focuses largely on the consequences of single electron transfer to poly- and perfluorinated arenes and 2-halo azoles. Electron transfer converts these stable molecules into reactive intermediates whose behavior often depends entirely on the identity of the halogen that undergoes substitution. The result is both diverse chemistry and an alternative way of thinking about the chemical reactivity of these motifs. Specifically, we discuss our efforts and those of others to develop strategies for the generation of radicals or radical anions from perfluoroarenes and azoles and the behavior of these intermediates as implied by reactions in which they participate. The divergent pathway is illustrated by 2-bromoazoles, which yield azolyl radicals and can be utilized for addition to π-bonds, while use of the 2-chloroazole substrate leads to an entirely different reaction profile. Under the appropriate reaction conditions, the reactive and transient intermediates are useful coupling partners and often provide unrivaled access to new

  2. Involvement of plasma membrane Ca2+ channels, IP3 receptors, and ryanodine receptors in the generation of spontaneous rhythmic contractions of the cricket lateral oviduct.

    Science.gov (United States)

    Tamashiro, Hirotake; Yoshino, Masami

    2014-12-01

    In the present study, the isolated cricket (Gryllus bimaculatus) lateral oviduct exhibited spontaneous rhythmic contractions (SRCs) with a frequency of 0.29±0.009 Hz (n=43) and an amplitude of 14.6±1.25 mg (n=29). SRCs completely disappeared following removal of extracellular Ca2+ using a solution containing 5mM EGTA. Application of the non-specific Ca2+ channel blockers Co2+, Ni2+, and Cd2+ also decreased both the frequency and amplitude of SRCs in dose-dependent manners, suggesting that Ca2+ entry through plasma membrane Ca2+ channels is essential for the generation of SRCs. Application of ryanodine (30 μM), which depletes intracellular Ca2+ by locking ryanodine receptor (RyR)-Ca2+ channels in an open state, gradually reduced the frequency and amplitude of SRCs. A RyR antagonist, tetracaine, reduced both the frequency and amplitude of SRCs, whereas a RyR activator, caffeine, increased the frequency of SRCs with a subsequent increase in basal tonus, indicating that RyRs are essential for generating SRCs. To further investigate the involvement of phospholipase C (PLC) and inositol 1,4,5-trisphosphate receptors (IP3Rs) in SRCs, we examined the effect of a PLC inhibitor, U73122, and an IP3R antagonist, 2-aminoethoxydiphenyl borate (2-APB), on SRCs. Separately, U73122 (10 μM) and 2-APB (30-50 μM) both significantly reduced the amplitude of SRCs with little effect on their frequency, further indicating that the PLC/IP3R signaling pathway is fundamental to the modulation of the amplitude of SRCs. A hypotonic-induced increase in the frequency and amplitude of SRCs and a hypertonic-induced decrease in the frequency and amplitude of SRCs indicated that mechanical stretch of the lateral oviduct is involved in the generation of SRCs. The sarcoplasmic reticulum Ca2+-pump ATPase inhibitors thapsigargin and cyclopiazonic acid impaired or suppressed the relaxation phase of SRCs. Taken together, the present results indicate that Ca2+ influx through plasma membrane Ca2

  3. The Development of the Advanced Light Water Reactor in Korea - The Korean Next Generation Reactor -

    Energy Technology Data Exchange (ETDEWEB)

    Kim, H.G.; Park, Y.S.; Kim, B.S.; Cho, S.J. [Korea Electric Power Research Institute, Taejon (Korea)

    1999-07-01

    Korean next generation reactor (KNGR), which is to be designed as a standard evolutionary advanced light water reactor (ALWR) in Korea, has been developed from 1992 as one of long-term government projects. The major characteristics of the KNGR are as follows; KNGR is 2-loop PWR and its design lift time is 60 years. The CDF and the CFF will be much lower than 10{sup -5}/RY and 10{sup -6}/RY, respectively. For the design improvement, KNGR adopted inconel-690 as a steam generator tube material, four train ECCS, refueling water storage tank inside containment, and double cylindrical concrete containment. For more reliable and easier control, compact workstations have been adopted in the design of main control complex and digital I and C technology is used for protection, control, and monitoring. In addition, KNGR has some passive design features such as fluidic device in safety injection tank, passive secondary condensing system, and passive auto-catalytic hydrogen recombiner to enhance safety. (author). 4 refs., 4 figs.

  4. Generation of Attosecond Light Pulses from Gas and Solid State Media

    Directory of Open Access Journals (Sweden)

    Stefanos Chatziathanasiou

    2017-03-01

    Full Text Available Real-time observation of ultrafast dynamics in the microcosm is a fundamental approach for understanding the internal evolution of physical, chemical and biological systems. Tools for tracing such dynamics are flashes of light with duration comparable to or shorter than the characteristic evolution times of the system under investigation. While femtosecond (fs pulses are successfully used to investigate vibrational dynamics in molecular systems, real time observation of electron motion in all states of matter requires temporal resolution in the attosecond (1 attosecond (asec = 10−18 s time scale. During the last decades, continuous efforts in ultra-short pulse engineering led to the development of table-top sources which can produce asec pulses. These pulses have been synthesized by using broadband coherent radiation in the extreme ultraviolet (XUV spectral region generated by the interaction of matter with intense fs pulses. Here, we will review asec pulses generated by the interaction of gas phase media and solid surfaces with intense fs IR laser fields. After a brief overview of the fundamental process underlying the XUV emission form these media, we will review the current technology, specifications and the ongoing developments of such asec sources.

  5. 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...

  6. Generating shaped femtosecond pulses in the far infrared using a spatial light modulator and difference frequency generation

    CSIR Research Space (South Africa)

    Botha, N

    2010-08-31

    Full Text Available Femtosecond pulse shaping can be done by different kinds of pulse shapers, such as liquid crystal spatial light modulators (LC SLM), acousto optic modulators (AOM) and deformable and movable mirrors. A few applications where pulse shaping...

  7. [Spontaneous bacterial peritonitis].

    Science.gov (United States)

    Strauss, Edna; Caly, Wanda Regina

    2003-01-01

    Spontaneous bacterial peritonitis occurs in 30% of patients with ascites due to cirrhosis leading to high morbidity and mortality rates. The pathogenesis of spontaneous bacterial peritonitis is related to altered host defenses observed in end-stage liver disease, overgrowth of microorganisms, and bacterial translocation from the intestinal lumen to mesenteric lymph nodes. Clinical manifestations vary from severe to slight or absent, demanding analysis of the ascitic fluid. The diagnosis is confirmed by a number of neutrophils over 250/mm3 associated or not to bacterial growth in culture of an ascites sample. Enterobacteriae prevail and Escherichia coli has been the most frequent bacterium reported. Mortality rates decreased markedly in the last two decades due to early diagnosis and prompt antibiotic treatment. Third generation intravenous cephalosporins are effective in 70% to 95% of the cases. Recurrence of spontaneous bacterial peritonitis is common and can be prevented by the continuous use of oral norfloxacin. The development of bacterial resistance demands the search for new options in the prophylaxis of spontaneous bacterial peritonitis; probiotics are a promising new approach, but deserve further evaluation. Short-term antibiotic prophylaxis is recommended for patients with cirrhosis and ascites shortly after an acute episode of gastrointestinal bleeding.

  8. Light

    CERN Document Server

    Rivera, Andrea

    2017-01-01

    Light is all around us. Learn how it is used in art, technology, and engineering. Five easy-to-read chapters explain the science behind light, as well as its real-world applications. Vibrant, full-color photos, bolded glossary words, and a key stats section let readers zoom in even deeper. Aligned to Common Core Standards and correlated to state standards. Abdo Zoom is a division of ABDO.

  9. Generating structured light with phase helix and intensity helix using reflection-enhanced plasmonic metasurface at 2 μm

    Science.gov (United States)

    Zhao, Yifan; Du, Jing; Zhang, Jinrun; Shen, Li; Wang, Jian

    2018-04-01

    Mid-infrared (2-20 μm) light has been attracting great attention in many areas of science and technology. Beyond the extended wavelength range from visible and near-infrared to mid-infrared, shaping spatial structures may add opportunities to grooming applications of mid-infrared photonics. Here, we design and fabricate a reflection-enhanced plasmonic metasurface and demonstrate efficient generation of structured light with the phase helix and intensity helix at 2 μm. This work includes two distinct aspects. First, structured light (phase helix, intensity helix) generation at 2 μm, which is far beyond the ability of conventional spatial light modulators, is enabled by the metasurface with sub-wavelength engineered structures. Second, the self-referenced intensity helix against environmental noise is generated without using a spatially separated light. The demonstrations may open up advanced perspectives to structured light applications at 2 μm, such as phase helix for communications and non-communications (imaging, sensing) and intensity helix for enhanced microscopy and advanced metrology.

  10. Numerical simulation of generation of optical vortices at light beam propagation through a layer of a nematic liquid crystal

    Science.gov (United States)

    Galev, Roman; Kudryavtsev, Alexey; Trashkeev, Sergey

    2017-10-01

    Light beam propagation through an anisotropic liquid crystal medium is numerically simulated. The Maxwell equations are solved by the FDTD method on computational grids with up to 6 . 108 nodes. Propagation of the fundamental mode HE11 of the fiber-optical light guide through a layer of a nematic liquid crystal filling a transverse gap in the optical fiber and containing a disclination. The behavior of the angular moment as a function of the layer thickness and disclination power is studied. System parameters that ensure the most effective generation of twisted light beams are found.

  11. Light

    CERN Document Server

    Ditchburn, R W

    1963-01-01

    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

  12. Recent developments at 3rd generation storage ring light sources (3/4)

    CERN Multimedia

    CERN. Geneva

    2009-01-01

    Over the last decade, many 3rd generation storage ring light sources have been built and put into operation. Progressively, significant improvements have been brought to the machine performances and experiences developed at the first facilities have benefited to the most recently built ones. Most of the recent facilities are now featuring small emittances, high current together with high position stability. The small sizes of the electron beam at the source points impose achieving position stabilities in the sub micron range. The technology to build the insertion devices that produce the photon beams has reached a very mature state and enables 3 GeV medium energy /medium size machines to produce high brilliance beams up to the hard X-Ray range (10 - 30 keV). The designing of the optical set-up of a beamline includes now the choice of the best suited undulator. All these facilities are operated as “photon factories” and deliver their beams to many beamlines over several thousands hours per year. Some re...

  13. Recent developments at 3rd generation storage ring light sources (4/4)

    CERN Multimedia

    CERN. Geneva

    2009-01-01

    Over the last decade, many 3rd generation storage ring light sources have been built and put into operation. Progressively, significant improvements have been brought to the machine performances and experiences developed at the first facilities have benefited to the most recently built ones. Most of the recent facilities are now featuring small emittances, high current together with high position stability. The small sizes of the electron beam at the source points impose achieving position stabilities in the sub micron range. The technology to build the insertion devices that produce the photon beams has reached a very mature state and enables 3 GeV medium energy /medium size machines to produce high brilliance beams up to the hard X-Ray range (10 - 30 keV). The designing of the optical set-up of a beamline includes now the choice of the best suited undulator. All these facilities are operated as “photon factories” and deliver their beams to many beamlines over several thousands hours per year. Some re...

  14. Recent developments at 3rd generation storage ring light sources (2/4)

    CERN Multimedia

    CERN. Geneva

    2009-01-01

    Over the last decade, many 3rd generation storage ring light sources have been built and put into operation. Progressively, significant improvements have been brought to the machine performances and experiences developed at the first facilities have benefited to the most recently built ones. Most of the recent facilities are now featuring small emittances, high current together with high position stability. The small sizes of the electron beam at the source points impose achieving position stabilities in the sub micron range. The technology to build the insertion devices that produce the photon beams has reached a very mature state and enables 3 GeV medium energy /medium size machines to produce high brilliance beams up to the hard X-Ray range (10 - 30 keV). The designing of the optical set-up of a beamline includes now the choice of the best suited undulator. All these facilities are operated as “photon factories” and deliver their beams to many beamlines over several thousands hours per year. Some re...

  15. Recent developments at 3rd generation storage ring light sources (1/4)

    CERN Multimedia

    CERN. Geneva

    2009-01-01

    Over the last decade, many 3rd generation storage ring light sources have been built and put into operation. Progressively, significant improvements have been brought to the machine performances and experiences developed at the first facilities have benefited to the most recently built ones. Most of the recent facilities are now featuring small emittances, high current together with high position stability. The small sizes of the electron beam at the source points impose achieving position stabilities in the sub micron range. The technology to build the insertion devices that produce the photon beams has reached a very mature state and enables 3 GeV medium energy /medium size machines to produce high brilliance beams up to the hard X-Ray range (10 - 30 keV). The designing of the optical set-up of a beamline includes now the choice of the best suited undulator. All these facilities are operated as “photon factories” and deliver their beams to many beamlines over several thousands hours per year. Some re...

  16. Treatment of ground water contaminated with volatile organic compounds using second generation ultraviolet light technology

    International Nuclear Information System (INIS)

    Lyandres, S.E.; Rees, J.T.; Folsom, E.N.; Boegel, A.J.

    1991-03-01

    Pilot tests, using a second generation ultraviolet (UV) light technology, were run on ground water samples taken f rom two separate aquifers contaminated with volatile organic compounds (VOCS) at the Lawrence Livermore National Laboratory (LLNL) in Alameda County, California. The VOCs included gasoline, TCE, and 1,2-DCA. VOC concentrations in the ground water ranged from 11 to 1,000 ppB. Discharges of treated ground water at LLNL are not to exceed 5 ppb total VOCs under a Federal National Pollution Discharge Elimination System discharge permit. Test results indicated that double-bonded VOCS, including aromatic compounds and TCE, were decomposed quickly and efficiently to low or nondetectable levels (<0.5 ppB, analyzed with a gas chromatograph). An equivalent level of degradation for 1,2-DCA required a moderately higher UV energy input and greater concentrations of additives. Concentrations of peroxide tested ranged between 10 and 60 ppM; however, those above 30 ppM did not significantly increase the rate of VOC destruction

  17. Parity generator and parity checker in the modified trinary number system using savart plate and spatial light modulator

    Science.gov (United States)

    Ghosh, Amal K.

    2010-09-01

    The parity generators and the checkers are the most important circuits in communication systems. With the development of multi-valued logic (MVL), the proposed system with parity generators and checkers is the most required using the recently developed optoelectronic technology in the modified trinary number (MTN) system. This system also meets up the tremendous needs of speeds by exploiting the savart plates and spatial light modulators (SLM) in the optical tree architecture (OTA).

  18. Femtosecond timing distribution and control for next generation accelerators and light sources

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Li -Jin [Idesta Quantum Electronics, LLC, Newton, NJ (United States)

    2014-03-31

    Femtosecond Timing Distribution At LCLS Free-electron-lasers (FEL) have the capability of producing high photon flux from the IR to the hard x-ray wavelength range and to emit femtosecond and eventually even attosecond pulses. This makes them an ideal tool for fundamental as well as applied re-search. Timing precision at the Stanford Linear Coherent Light Source (LCLS) between the x-ray FEL (XFEL) and ultrafast optical lasers is currently no better than 100 fs RMS. Ideally this precision should be much better and could be limited only by the x-ray pulse duration, which can be as short as a few femtoseconds. An increasing variety of science problems involving electron and nuclear dynamics in chemical and material systems will become accessible as the timing improves to a few femtoseconds. Advanced methods of electron beam conditioning or pulse injection could allow the FEL to achieve pulse durations less than one femtosecond. The objective of the work described in this proposal is to set up an optical timing distribution system based on mode locked Erbium doped fiber lasers at LCLS facility to improve the timing precision in the facility and allow time stamping with a 10 fs precision. The primary commercial applications for optical timing distributions systems are seen in the worldwide accelerator facilities and next generation light sources community. It is reasonable to expect that at least three major XFELs will be built in the next decade. In addition there will be up to 10 smaller machines, such as FERMI in Italy and Maxlab in Sweden, plus the market for upgrading already existing facilities like Jefferson Lab. The total market is estimated to be on the order of a 100 Million US Dollars. The company owns the exclusive rights to the IP covering the technology enabling sub-10 fs synchronization systems. Testing this technology, which has set records in a lab environment, at LCLS, hence in a real world scenario, is an important corner stone of bringing the

  19. Self-sufficient energy recycling of light emitter diode/thermoelectric generator module for its active-cooling application

    International Nuclear Information System (INIS)

    Tsai, Huan-Liang; Le, Phuong Truong

    2016-01-01

    Highlights: • A novel light emitting diode/thermoelectric generator module is implemented. • The waste heat recycling for both self-sufficient and active-cooling functions is validated. • The improvements in the illuminance and working temperature of the lighting device are demonstrated. - Abstract: This paper presents the energy recycling and self-sufficient application of a novel high-power light emitting diode integrating with a thermoelectric generator module. The proposed lighting module in which a thermoelectric generator device is sandwiched between light emitting diode device and heat sink autonomously recycles the waste heat to self-sufficiently support for its active cooling with an electrical fan. The start-up responses of illuminance, temperature, current and power for the proposed module were evaluated through experimental measurement. The corresponding mathematical model was derived and simulation model was built using MATLAB/Simulink for verification. The illuminance, electrical, and thermal performances have a close agreement between experiment and simulation results. The technological viability about both autonomous operation and self-sufficient energy recycling for the novel module with the active cooling was validated. Compared with passive-cooling devices, the proposed module declines the working temperature and improves illuminance simultaneously.

  20. Ethanol fumigation combined with and without nitrogen gas delays potato greening and inhibits Glycoalkaloid generation under light

    Science.gov (United States)

    Postharvest potato greening under light accompanied by the generation of toxic glycoalkaloids results in a potential serious health risk and great postharvest losses. This study examined the inhibiting effects of ethanol fumigation and ethanol fumigation combined with N2 treatment on potato greening...

  1. Efficient generation of continuous-wave yellow-orange light using sum-frequency in periodically poled KTP

    DEFF Research Database (Denmark)

    Janousek, Jiri; Johansson, Sandra; Tidemand-Lichtenberg, Peter

    We present highly efficient sum-frequency generation between two CW 1064 and 1342 nm laser lines of two Nd:YVO4 lasers using periodically poled KTP. This is an all solid-state light source in the yellow-orange spectral range....

  2. 76 FR 35886 - Notice Updating Procedural Schedule for Licensing; FirstLight Hydro Generating Company, City of...

    Science.gov (United States)

    2011-06-20

    ... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Project No. 2662-012; Project No. 12968-001] Notice Updating Procedural Schedule for Licensing; FirstLight Hydro Generating Company, City of... Hydroelectric Project No. 2662 and Scotland Hydroelectric Project No. 12968 has been updated. Subsequent...

  3. 76 FR 18217 - FirstLight Hydro Generating Company, City of Norwich Department of Public Utilities; Notice...

    Science.gov (United States)

    2011-04-01

    ... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Project No. 2662-012; Project No. 12968-001] FirstLight Hydro Generating Company, City of Norwich Department of Public Utilities; Notice... Scotland Hydroelectric Project No. 2662 and Scotland Hydroelectric Project No. 12968 has been updated...

  4. 78 FR 4843 - FirstLight Hydro Generating Company, City of Norwich Dept. of Public Utilities; Notice of...

    Science.gov (United States)

    2013-01-23

    ... Public Utilities (Norwich Public Utilities). Staff has prepared a final environmental assessment (EA... and Norwich Public Utilities, and concludes that licensing the project with either proposal, with... Energy Regulatory Commission FirstLight Hydro Generating Company, City of Norwich Dept. of Public...

  5. Efficient concept for generation of diffraction-limited green light by sum-frequency generation of spectrally combined tapered diode lasers

    DEFF Research Database (Denmark)

    Müller, André; Jensen, Ole Bjarlin; Hasler, Karl-Heinz

    2012-01-01

    In order to increase the power of visible diode laser systems in an efficient manner, we propose spectral beam combining with subsequent sum-frequency generation. We show that this approach, in comparison with second harmonic generation of single emitters, can enhance the available power signific......In order to increase the power of visible diode laser systems in an efficient manner, we propose spectral beam combining with subsequent sum-frequency generation. We show that this approach, in comparison with second harmonic generation of single emitters, can enhance the available power...... significantly. By combining two distributed Bragg reflector tapered diode lasers we achieve a 2.5–3.2 fold increase in power and a maximum of 3.9 W of diffraction-limited green light. At this power level, green diode laser systems have a high application potential, e.g., within the biomedical field. Our concept...

  6. Critical roles for LIGHT and its receptors in generating T cell-mediated immunity during Leishmania donovani infection.

    Directory of Open Access Journals (Sweden)

    Amanda C Stanley

    2011-10-01

    Full Text Available LIGHT (TNFSF14 is a member of the TNF superfamily involved in inflammation and defence against infection. LIGHT signals via two cell-bound receptors; herpes virus entry mediator (HVEM and lymphotoxin-beta receptor (LTβR. We found that LIGHT is critical for control of hepatic parasite growth in mice with visceral leishmaniasis (VL caused by infection with the protozoan parasite Leishmania donovani. LIGHT-HVEM signalling is essential for early dendritic cell IL-12/IL-23p40 production, and the generation of IFNγ- and TNF-producing T cells that control hepatic infection. However, we also discovered that LIGHT-LTβR interactions suppress anti-parasitic immunity in the liver in the first 7 days of infection by mechanisms that restrict both CD4(+ T cell function and TNF-dependent microbicidal mechanisms. Thus, we have identified distinct roles for LIGHT in infection, and show that manipulation of interactions between LIGHT and its receptors may be used for therapeutic advantage.

  7. Fast and slow light generated by surface plasmon wave and gold grating coupling effects

    Science.gov (United States)

    Amiri, Iraj S.; Ariannejad, M. M.; Tajdidzadeh, M.; Sorger, Volker J.; Ling, Xi; Yupapin, P.

    2018-01-01

    We present here the results of a simulation of the effect of gold and graphene coatings on silicon micro-ring resonators. We studied the effect of different radii of graphene on the time delay, from which one an interesting aspect of light pulse behaviors, such as fast light, was numerically investigated. The obtained results indicate that the time delay can be varied, which is in good agreement with theoretical predictions. Fast and slow light pulse trains can be obtained by modifying the throughput port, which forms the gold grating length. The temporal gaps between the fast and slow light in the used graphene and gold are 140 and 168 fs, respectively, which can be tuned by varying the radius or grating length. The obtained results show that such a device may be useful in applications requiring fast and slow light pulse train pairs, such as optical switching, sensors, communications, and security applications.

  8. Spontaneous ultra-weak light emissions from wheat seedlings are rhythmic and synchronized with the time profile of the local gravimetric tide.

    Science.gov (United States)

    Moraes, Thiago A; Barlow, Peter W; Klingelé, Emile; Gallep, Cristiano M

    2012-06-01

    Semi-circadian rhythms of spontaneous photon emission from wheat seedlings germinated and grown in a constant environment (darkened chamber) were found to be synchronized with the rhythm of the local gravimetric (lunisolar) tidal acceleration. Time courses of the photon-count curves were also found to match the growth velocity profile of the seedlings. Pair-wise analyses of the data--growth, photon count, and tidal--by local tracking correlation always revealed significant coefficients (P > 0.7) for more than 80% of any of the time periods considered. Using fast Fourier transform, the photon-count data revealed periodic components similar to those of the gravimetric tide. Time courses of biophoton emissions would appear to be an additional, useful, and innovative tool in both chronobiological and biophysical studies.

  9. Photonic linear chirped microwave signal generation based on the ultra-compact spectral shaper using the slow light effect

    DEFF Research Database (Denmark)

    Yan, Siqi; Gao, Shengqian; Zhou, Feng

    2017-01-01

    A novel concept to generate a linear chirped microwave signal is proposed and experimentally demonstrated. The frequency to time mapping method is employed, where the photonic crystal waveguide Mach-Zehnder interferometer structure acts as the spectral shaper thanks to the slow light effect. By o....... The utilization of the slow light effect brings in significant advantages, including the ultra-small footprint of 0.096 mm(2) and simple structure to our scheme, which may be of great importance towards its potential applications. (C) 2017 Optical Society of America...

  10. Development of Advanced Fourth Generation Light Sources for the Accelerator Science Laboratory

    OpenAIRE

    Chanwattana, Thakonwat; Bartolini, Riccardo; Seryi, Andrei; Tsesmelis, Emmanuel

    2015-01-01

    The John Adams Institute for Accelerator Science (JAI) has proposed the realisation of the Accelerator Science Laboratory (ASL) at the University of Oxford as a facility for the development of advanced compact light sources enabling accelerator science research and applications. The installation of a compact light source in the ASL is planned with two options for the accelerating technologies. Firstly, a conventional RF based accelerator is considered to be a driver for a short pulse THz cohe...

  11. Light generation and manipulation from nonlinear randomly distributed domains in SBN

    OpenAIRE

    Yao, Can

    2014-01-01

    Disordered media with refractive index variations can be found in the atmosphere, the ocean, and in many materials or biological tissues. Several technologies that make use of such random media, as image formation, satellite communication, astronomy or microscopy, must deal with an unavoidable light scattering or diffusion. This is why for many years light propagation through random media has been a subject of intensive study. Interesting phenomena such as speckle, coherent backscattering or ...

  12. New Perspectives on Spontaneous Brain Activity: Dynamic Networks and Energy Matter

    Science.gov (United States)

    Tozzi, Arturo; Zare, Marzieh; Benasich, April A.

    2016-01-01

    Spontaneous brain activity has received increasing attention as demonstrated by the exponential rise in the number of published article on this topic over the last 30 years. Such “intrinsic” brain activity, generated in the absence of an explicit task, is frequently associated with resting-state or default-mode networks (DMN)s. The focus on characterizing spontaneous brain activity promises to shed new light on questions concerning the structural and functional architecture of the brain and how they are related to “mind”. However, many critical questions have yet to be addressed. In this review, we focus on a scarcely explored area, specifically the energetic requirements and constraints of spontaneous activity, taking into account both thermodynamical and informational perspectives. We argue that the “classical” definitions of spontaneous activity do not take into account an important feature, that is, the critical thermodynamic energetic differences between spontaneous and evoked brain activity. Spontaneous brain activity is associated with slower oscillations compared with evoked, task-related activity, hence it exhibits lower levels of enthalpy and “free-energy” (i.e., the energy that can be converted to do work), thus supporting noteworthy thermodynamic energetic differences between spontaneous and evoked brain activity. Increased spike frequency during evoked activity has a significant metabolic cost, consequently, brain functions traditionally associated with spontaneous activity, such as mind wandering, require less energy that other nervous activities. We also review recent empirical observations in neuroscience, in order to capture how spontaneous brain dynamics and mental function can be embedded in a non-linear dynamical framework, which considers nervous activity in terms of phase spaces, particle trajectories, random walks, attractors and/or paths at the edge of the chaos. This takes us from the thermodynamic free-energy, to the realm

  13. Adaptive Generation and Diagnostics of Linear Few-Cycle Light Bullets

    Directory of Open Access Journals (Sweden)

    Martin Bock

    2013-02-01

    Full Text Available Recently we introduced the class of highly localized wavepackets (HLWs as a generalization of optical Bessel-like needle beams. Here we report on the progress in this field. In contrast to pulsed Bessel beams and Airy beams, ultrashort-pulsed HLWs propagate with high stability in both spatial and temporal domain, are nearly paraxial (supercollimated, have fringe-less spatial profiles and thus represent the best possible approximation to linear “light bullets”. Like Bessel beams and Airy beams, HLWs show self-reconstructing behavior. Adaptive HLWs can be shaped by ultraflat three-dimensional phase profiles (generalized axicons which are programmed via calibrated grayscale maps of liquid-crystal-on-silicon spatial light modulators (LCoS-SLMs. Light bullets of even higher complexity can either be freely formed from quasi-continuous phase maps or discretely composed from addressable arrays of identical nondiffracting beams. The characterization of few-cycle light bullets requires spatially resolved measuring techniques. In our experiments, wavefront, pulse and phase were detected with a Shack-Hartmann wavefront sensor, 2D-autocorrelation and spectral phase interferometry for direct electric-field reconstruction (SPIDER. The combination of the unique propagation properties of light bullets with the flexibility of adaptive optics opens new prospects for applications of structured light like optical tweezers, microscopy, data transfer and storage, laser fusion, plasmon control or nonlinear spectroscopy.

  14. Occlusion processing for computer generated hologram by conversion between the wavefront and light-ray information

    Science.gov (United States)

    Wakunami, Koki; Yamaguchi, Masahiro

    2013-02-01

    In the field of computational holography for three-dimensional (3D) display, the mutual occlusion of objects is one of the crucial issues. We propose a new mutual occlusion processing that is achieved by the conversion between the light-ray and wavefront on a virtual plane called ray-sampling (RS) plane located at near the interrupting object. The wavefront coming from background scene is converted into light-ray information at the RS plane by using Fourier transform based on the angular spectrum theory, then the converted light-rays are overwritten with those from interrupting object in the light-ray domain as an occlusion culling process. The ray information after the occlusion process is reconverted into wavefront by inverse Fourier transform at each RS point, then wave propagation from RS plane to hologram is computed by general light diffraction computation techniques. Since the light-ray information is used for the occlusion processing, our approach can realize a correct occlusion effect by a simple algorithm. In addition, high resolution 3D image can be reconstructed with wavefront-based technique. In the numerical simulation, we demonstrate that our approach for deep 3D scene with plural objects can realize a correct occlusion culling for varying observation angle and focusing distance.

  15. Donor doping process and white light generation in CaMoO4 powders with multivalence Pr codoping

    International Nuclear Information System (INIS)

    Zhu Fang; Xiao Zhisong; Zhang Feng; Yan Lu; Huang Anping

    2011-01-01

    Both trivalent praseodymium (Pr 3+ ) and quadrivalent praseodymium (Pr 4+ ) were doped in molybdate powders. Visible emission from matrix was enhanced by multivalent Pr codoping. It was proposed that Pr 3+ ions was donor and supplied quasi-free electron when Pr 3+ took place the Pr 4+ sites. The result showed that multivalence codoping would be an effective way to enhance emission of CaMoO 4 . White light can be generated from Ca 0.98 Pr 0.02 MoO 4 powder via combination of broadband emissions originated from CaMoO 4 matrix and radiative transition of Pr 3+ . It showed warm white light with T c of 3450 K that implies promising application in white light emitting diodes (LEDs).

  16. Generation of shock fronts in the interaction of short pulses of intense laser light in supercritical plasma

    International Nuclear Information System (INIS)

    Lopez V, V.E.; Ondarza R, R.

    2004-01-01

    The investigation of the laser interaction with plasma has been carried out mainly in laboratories of Europe, Japan and United States during the last decades. This studies concern the propagation of intense light laser in a non homogeneous plasma, the radiation absorption and the generation of suprathermal electrons, among others. Numerical simulations made by Denavit, for radiation pulses for up of 10 20 W/cm 2 on solid targets, have allowed to observe the generation of ionic crash fronts with high propagation speeds. In this work it is expanded the study of this effect through algorithms of particles simulation. (Author)

  17. Efficient generation of 3.9 W of diffraction-limited green light with spectrally combined tapered diode lasers

    DEFF Research Database (Denmark)

    Müller, André; Jensen, Ole Bjarlin; Andersen, Peter E.

    We propose an efficient concept increasing the power of diode laser systems in the visible spectral range. In comparison with second harmonic generation of single emitters, spectral beam combining with subsequent sum-frequency generation enhances the available power significantly. Combining two...... 1060 nm tapered diode lasers, we achieve a 2.5-3.2 fold increase of green light with a maximum power of 3.9 Watts in a diffraction-limited beam. At this level, diode lasers have a high application potential, for example, within the biomedical field. In order to enhance the power even further, our...

  18. Efficient concept generating 3.9 W of diffraction-limited green light with spectrally combined tapered diode lasers

    DEFF Research Database (Denmark)

    Müller, André; Jensen, Ole Bjarlin; Hasler, Karl-Heinz

    2013-01-01

    We propose an efficient concept increasing the power of diode laser systems in the visible spectral range. In comparison with second harmonic generation of single emitters, we show that spectral beam combining with subsequent sumfrequency generation enhances the available power significantly....... Combining two 1060 nm distributed Bragg reflector tapered diode lasers (M 24σ ≤ 5.2), we achieve a 2.5-3.2 fold increase of green light with a maximum power of 3.9 Watts in a diffraction-limited beam (M 24σ ≤ 1.3). Without any further stabilization the obtained power stability is within ± 2.6 %. The electro...

  19. Involvement of cyclic nucleotide-gated channels in spontaneous activity generated in isolated interstitial cells of Cajal from the rabbit urethra.

    Science.gov (United States)

    Sancho, Maria; Bradley, Eamonn; Garcia-Pascual, Angeles; Triguero, Domingo; Thornbury, Keith D; Hollywood, Mark A; Sergeant, Gerard P

    2017-11-05

    Cyclic nucleotide-gated (CNG) channels are non-selective cation channels that mediate influx of extracellular Na + and Ca 2+ in various cell types. L-cis-Diltiazem, a CNG channel blocker, inhibits contraction of urethral smooth muscle (USM), however the mechanisms underlying this effect are still unclear. We investigated the possibility that CNG channels contribute to spontaneous pacemaker activity in freshly isolated interstitial cells of Cajal (ICC) isolated from the rabbit urethra (RUICC). Using immunocytochemistry, we found intense CNG1-immunoreactivity in vimentin-immunoreactive RUICC, mainly within patches of the cellular body and processes. In contrast, α-actin immunoreactive smooth muscle cells (SMC) did not show significant reactivity to a specific CNGA1 antibody. Freshly isolated RUICC, voltage clamped at -60mV, developed spontaneous transient inward currents (STICs) that were inhibited by L-cis-Diltiazem (50µM). Similarly, L-cis-Diltiazem (50µM) also inhibited Ca 2+ waves in isolated RUICC, recorded using a Nipkow spinning disk confocal microscope. L-cis-Diltiazem (50µM) did not affect caffeine (10mM)-induced Ca 2+ transients, but significantly reduced phenylephrine-evoked Ca 2+ oscillations and inward currents in in RUICC. L-type Ca 2+ current amplitude in isolated SMC was reduced by ~18% in the presence of L-cis-Diltiazem (50µM), however D-cis-Diltiazem, a recognised L-type Ca 2+ channel blocker, abolished L-type Ca 2+ current but did not affect Ca 2+ waves or STICs in RUICC. These results indicate that the effects of L-cis-diltiazem on rabbit USM could be mediated by inhibition of CNG1 channels that are present in urethral ICC and therefore CNG channels contribute to spontaneous activity in these cells. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. Enhancement of efficiencies for tandem green phosphorescent organic light-emitting devices with a p-type charge generation layer

    Energy Technology Data Exchange (ETDEWEB)

    Yoo, Byung Soo; Jeon, Young Pyo; Lee, Dae Uk; Kim, Tae Whan, E-mail: twk@hanayng.ac.kr

    2014-10-15

    The operating voltage of the tandem green phosphorescent organic light-emitting device with a 1,4,5,8,9,11-hexaazatriphenylene-hexacarbonitrile layer was improved by 3% over that of the organic light-emitting device with a molybdenum trioxide layer. The maximum brightness of the tandem green phosphorescent organic light-emitting device at 21.9 V was 26,540 cd/m{sup 2}. The dominant peak of the electroluminescence spectra for the devices was related to the fac-tris(2-phenylpyridine) iridium emission. - Highlights: • Tandem OLEDs with CGL were fabricated to enhance their efficiency. • The operating voltage of the tandem OLED with a HAT-CN layer was improved by 3%. • The efficiency and brightness of the tandem OLED were 13.9 cd/A and 26,540 cd/m{sup 2}. • Efficiency of the OLED with a HAT-CN layer was lower than that with a MoO{sub 3} layer. - Abstract: Tandem green phosphorescent organic light-emitting devices with a 1,4,5,8,9,11-hexaazatriphenylene-hexacarbonitrile or a molybdenum trioxide charge generation layer were fabricated to enhance their efficiency. Current density–voltage curves showed that the operating voltage of the tandem green phosphorescent organic light-emitting device with a 1,4,5,8,9,11-hexaazatriphenylene-hexacarbonitrile layer was improved by 3% over that of the corresponding organic light-emitting device with a molybdenum trioxide layer. The efficiency and the brightness of the tandem green phosphorescent organic light-emitting device were 13.9 cd/A and 26,540 cd/m{sup 2}, respectively. The current efficiency of the tandem green phosphorescent organic light-emitting device with a 1,4,5,8,9,11-hexaazatriphenylene-hexacarbonitrile layer was lower by 1.1 times compared to that of the corresponding organic light-emitting device with molybdenum trioxide layer due to the decreased charge generation and transport in the 1,4,5,8,9,11-hexaazatriphenylene-hexacarbonitrile layer resulting from triplet–triplet exciton annihilation.

  1. The generation of short-wave UV light in cells under the action of ultrashort pulses of intense visible radiation

    Science.gov (United States)

    Kovarsky, V. A.; Philipp, B. S.; Kovarsky, E. V.

    1997-02-01

    The action of intense laser pulses ( λ = 0.53 μm) on E.coli cells is considered (the cells are transparent in this range). The transformation of laser radiation into UV light due to the high-harmonics generation on the protein molecules (the dipole moment is 100-1000 D) leads to the appearance of thymine dimers in bacterial DNA and results in a lethal effect for strains of E.coli which are highly sensitive to UV radiation.

  2. What makes single-helical metamaterials generate "pure" circularly polarized light?

    Science.gov (United States)

    Wu, Lin; Yang, ZhenYu; Zhao, Ming; Zhang, Peng; Lu, ZeQing; Yu, Yang; Li, ShengXi; Yuan, XiuHua

    2012-01-16

    Circular polarizers with left-handed helical metamaterials can transmit right-handed circularly polarized (RCP) light with few losses. But a certain amount of left-handed circularly polarized (LCP) light will occur in the transmitted light, which is the noise of the circular polarizer. Therefore, we defined the ratio of the RCP light intensity to the LCP light intensity as the signal-to-noise (S/N) ratio. In our previous work, it's found that circular polarizers with multi-helical metamaterials have two orders higher S/N ratios than that of single-helical metamaterials. However, it has been a great challenge to fabricate such multi-helical structures with micron or sub-micron feature sizes. Is it possible for the single-helical metamaterials to obtain equally high S/N ratios as the multi-helical ones? To answer this question, we systematically investigated the influences of structure parameters of single-helical metamaterials on the S/N ratios using the finite-different time-domain (FDTD) method. It was found that the single-helical metamaterials can also reach about 30dB S/N ratios, which are equal to the multi-helical ones. Furthermore, we explained the phenomenon by the antenna theory and optimized the performances of the single-helical circular polarizers.

  3. Heat generation and light scattering of green fluorescent protein-like pigments in coral tissue

    Science.gov (United States)

    Lyndby, Niclas H.; Kühl, Michael; Wangpraseurt, Daniel

    2016-05-01

    Green fluorescent protein (GFP)-like pigments have been proposed to have beneficial effects on coral photobiology. Here, we investigated the relationships between green fluorescence, coral heating and tissue optics for the massive coral Dipsastraea sp. (previously Favia sp.). We used microsensors to measure tissue scalar irradiance and temperature along with hyperspectral imaging and combined imaging of variable chlorophyll fluorescence and green fluorescence. Green fluorescence correlated positively with coral heating and scalar irradiance enhancement at the tissue surface. Coral tissue heating saturated for maximal levels of green fluorescence. The action spectrum of coral surface heating revealed that heating was highest under red (peaking at 680 nm) irradiance. Scalar irradiance enhancement in coral tissue was highest when illuminated with blue light, but up to 62% (for the case of highest green fluorescence) of this photon enhancement was due to green fluorescence emission. We suggest that GFP-like pigments scatter the incident radiation, which enhances light absorption and heating of the coral. However, heating saturates, because intense light scattering reduces the vertical penetration depth through the tissue eventually leading to reduced light absorption at high fluorescent pigment density. We conclude that fluorescent pigments can have a central role in modulating coral light absorption and heating.

  4. Generation of picosecond pulsed coherent state superpositions

    DEFF Research Database (Denmark)

    Dong, Ruifang; Tipsmark, Anders; Laghaout, Amine

    2014-01-01

    We present the generation of approximated coherent state superpositions-referred to as Schrodinger cat states-by the process of subtracting single photons from picosecond pulsed squeezed states of light. The squeezed vacuum states are produced by spontaneous parametric down-conversion (SPDC...

  5. Energy transfer and colour tunability in UV light induced Tm3+/Tb3+/Eu3+: ZnB glasses generating white light emission.

    Science.gov (United States)

    Naresh, V; Gupta, Kiran; Parthasaradhi Reddy, C; Ham, Byoung S

    2017-03-15

    A promising energy transfer (Tm 3+ →Tb 3+ →Eu 3+ ) approach is brought forward to generate white light emission under ultraviolet (UV) light excitation for solid state lightening. Tm 3+ /Tb 3+ /Eu 3+ ions are combinedly doped in zinc borate glass system in view of understanding energy transfer process resulting in white light emission. Zinc borate (host) glass displayed optical and luminescence properties due to formation of Zn(II) x -[O(-II)] y centres in the ZnB glass matrix. At 360nm (UV) excitation, triply doped Tm 3+ /Tb 3+ /Eu 3+ : ZnB glasses simultaneously shown their characteristic emission bands in blue (454nm: 1 D 2 → 3 F 4 ), green (547nm: 5 D 4 → 7 F 5 ) and red (616nm: 5 D 0 → 7 F 2 ) regions. In triple ions doped glasses, energy transfer dynamics is discussed in terms of Forster-Dexter theory, excitation & emission profiles, lifetime curves and from partial energy level diagram of three ions. The role of Tb 3+ in ET from Tm 3+ →Eu 3+ was discussed using branch model. From emission decay analysis, energy transfer probability (P) and efficiency (η) were evaluated. Colour tunability from blue to white on varying (Tb 3+ , Eu 3+ ) content is demonstrated from Commission Internationale de L'Eclairage (CIE) chromaticity coordinates. Based on chromaticity coordinates, other colour related parameters like correlated colour temperature (CCT) and colour purity are also computed for the studied glass samples. An appropriate blending of such combination of rare earth ions could show better suitability as potential candidates in achieving multi-colour and warm/cold white light emission for white LEDs application in the field of solid state lightening. Copyright © 2016 Elsevier B.V. All rights reserved.

  6. The 'spontaneous' acoustic emission of the shock front in a perfect fluid: solving a riddle

    International Nuclear Information System (INIS)

    Brun, Louis

    2013-06-01

    In the fifties, S. D'yakov discovered that theory allows for suitable EOS shock fronts to emit acoustic waves 'spontaneously'. Section 90 of Fluid Mechanics of Landau and Lifshitz, 2. Ed., deals with the phenomenon, leaving it unexplained. This open question was chosen to introduce a monograph in progress about 'the shock front in the perfect fluid'. The novelty of our approach consists in having the phenomenon generated - which means it is non-spontaneous -- from an appropriate solicitation of the front and studying its development analytically. The non classical source and mechanism of the emission are thus brought to light. (author)

  7. Innovative Development of Next Generation and Energy Efficient Solid State Light Sources for General Illumination

    Energy Technology Data Exchange (ETDEWEB)

    Ian Ferguson

    2006-07-31

    This two year program resulted in a novel broadband spectrally dynamic solid state illumination source (BSDLED) that uses a dual wavelength light emitting diode (LED) and combinations of phosphors to create a broadband emission that is real-time controllable. Four major focuses of this work were as follows: (1) creation of a two terminal dual wavelength LED with control of the relative intensities of the two emission peaks, (2) bandgap modeling of the two terminal dual LED to explain operation based on the doping profile, (3) novel use of phosphor combinations with dual LEDs to create a broadband spectral power distribution that can be varied to mimic a blackbody radiator over a certain range and (4) investigation of novel doping schemes to create tunnel junctions or equivalent buried current spreading layers in the III-nitrides. Advances were achieved in each of these four areas which could lead to more efficient solid state light sources with greater functionality over existing devices. The two-terminal BSDLED is an important innovation for the solid-state lighting industry as a variable spectrum source. A three-terminal dual emitter was also investigated and appears to be the most viable approach for future spectrally dynamic solid state lighting sources. However, at this time reabsorption of emission between the two active regions limits the usefulness of this device for illumination applications.

  8. Asymmetric Synthesis of Second-Generation Light-Driven Molecular Motors

    NARCIS (Netherlands)

    van Leeuwen, Thomas; Danowski, Wojciech; Otten, Edwin; Wezenberg, Sander J; Feringa, Ben L

    2017-01-01

    The enantiomeric homogeneity of light-driven molecular motors based on overcrowded alkenes is crucial in their application as either unidirectional rotors or as chiral multistate switches. It was challenging to obtain these compounds as single enantiomers via the established synthetic procedures due

  9. Experimental Study on Light Flash Radiant Intensity Generated by Strong Shock 2A12 Aluminum Plate

    Science.gov (United States)

    Tang, Enling; Zhang, Lijiao; Zhang, Qingming; Shi, Xiaohan; Wang, Meng; Wang, Di; Xiang, Shenghai; Xia, Jin; Han, Yafei; Xu, Mingyang; Wu, Jin; Zhang, Shuang; Yuan, Jianfei

    2015-07-01

    In order to study the light flash radiant intensity produced by strong shock on a 2A12 aluminum target at the same projectile incidence angles and different shock velocities, experimental measurements were conducted for light flash phenomena of a 2A12 aluminum projectile impacting a 2A12 aluminum target under the conditions of different impact velocity and the same projectile incidence angles of 45° by using an optical pyrometer measurement system and a two-stage light gas gun loading system. Experimental results show that the peak values of the light flash radiant intensity for the wavelength of 550 nm are largest in the wavelength ranges of 600 nm, 650 nm and 700 nm when a 2A12 aluminum projectile impacts a double-layer 2A12 aluminum plate in the present experimental conditions. supported by National Natural Science Foundation of China (Nos. 10972145, 11272218, 11472178), State Key Program of National Natural Science of China (No. 11032003), Program for Liaoning Excellent Talents in University, China (No. LR2013008)

  10. Efficient concept for generation of diffraction-limited green light by sum-frequency generation of spectrally combined tapered diode lasers.

    Science.gov (United States)

    Müller, André; Jensen, Ole Bjarlin; Hasler, Karl-Heinz; Sumpf, Bernd; Erbert, Götz; Andersen, Peter E; Petersen, Paul Michael

    2012-09-15

    In order to increase the power of visible diode laser systems in an efficient manner, we propose spectral beam combining with subsequent sum-frequency generation. We show that this approach, in comparison with second harmonic generation of single emitters, can enhance the available power significantly. By combining two distributed Bragg reflector tapered diode lasers we achieve a 2.5-3.2 fold increase in power and a maximum of 3.9 W of diffraction-limited green light. At this power level, green diode laser systems have a high application potential, e.g., within the biomedical field. Our concept can be expanded combining multiple diode lasers to increase the power even further.

  11. White light generation in Dy3+-and Ce3+/Dy3+-doped zinc–sodium–aluminosilicate glasses

    International Nuclear Information System (INIS)

    Caldiño, U.; Lira, A.; Meza-Rocha, A.N.; Pasquini, E.; Pelli, S.; Speghini, A.; Bettinelli, M.; Righini, G.C.

    2015-01-01

    A spectroscopic investigation of 1% Dy 2 O 3 -singly doped and 0.5% Ce 2 O 3 -1.0% Dy 2 O 3 -codoped zinc–sodium–aluminosilicate glasses was performed by analyzing their absorption and photoluminescence spectra, and decay times. Warm white yellow light emission, with (0.419, 0.440) CIE1931 chromaticity coordinates and 3579 K color temperature, is obtained in the Dy 3+ -singly doped glass excited at 399 nm, which fits to the requirements of GaN LEDs. A quantum efficiency of 74% and a very high optical gain (38.7×10 −25 cm 2 s) were estimated for the dysprosium 4 F 9/2 level luminescence, which might also make the Dy 3+ -doped glass a promising gain medium for solid state yellow laser pumped by GaN LEDs. In the Ce 3+ /Dy 3+ -codoped glass a radiative energy transfer from Ce 3+ to Dy 3+ is observed upon UV excitation (310–365 nm), with a Ce 3+ to Dy 3+ interaction distance that could be greater than 6–12 Å. The emission color from the codoped glass can be tuned with the excitation wavelength from blue light (0.247, 0.245), upon 310 nm excitation, to cold white light (0.284, 0.300), with a 9052 K color temperature, upon 365 nm excitation. - Highlights: • Zinc–sodium–aluminosilicate (ZN) glasses are optically activated with Dy 3+ (ZNDy). • ZN glasses are optically activated with Ce 3+ /Dy 3+ (ZNCeDy). • Dy 3+ is sensitized by Ce 3+ through a radiative energy transfer. • ZNDy glass can generate 3579 K warm white yellow light emission. • ZNCeDy glass can generate 9052 K cold white light emission

  12. One-Time Password Generation and Two-Factor Authentication Using Molecules and Light.

    Science.gov (United States)

    Naren, Gaowa; Li, Shiming; Andréasson, Joakim

    2017-07-05

    Herein, we report the first example of one-time password (OTP) generation and two-factor authentication (2FA) using a molecular approach. OTPs are passwords that are valid for one entry only. For the next login session, a new, different password is generated. This brings the advantage that any undesired recording of a password will not risk the security of the authentication process. Our molecular realization of the OTP generator is based on a photochromic molecular triad where the optical input required to set the triad to the fluorescent form differs depending on the initial isomeric state. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Light in complex dielectrics

    NARCIS (Netherlands)

    Schuurmans, F.J.P.

    1999-01-01

    In this thesis the properties of light in complex dielectrics are described, with the two general topics of "modification of spontaneous emission" and "Anderson localization of light". The first part focuses on the spontaneous emission rate of an excited atom in a dielectric host with variable

  14. Phosphors for near UV-Emitting LED's for Efficacious Generation of White Light

    Energy Technology Data Exchange (ETDEWEB)

    McKittrick, Joanna [Univ. of California, San Diego, CA (United States)

    2013-09-30

    1) We studied phosphors for near-UV (nUV) LED application as an alternative to blue LEDs currently being used in SSL systems. We have shown that nUV light sources could be very efficient at high current and will have significantly less binning at both the chip and phosphor levels. We identified phosphor blends that could yield 4100K lamps with a CRI of approximately 80 and LPWnUV,opt equal to 179 for the best performing phosphor blend. Considering the fact that the lamps were not optimized for light coupling, the results are quite impressive. The main bottleneck is an optimum blue phosphor with a peak near 440 nm with a full width half maximum of about 25 nm and a quantum efficiency of >95%. Unfortunately, that may be a very difficult task when we want to excite a phosphor at ~400 nm with a very small margin for Stokes shift. Another way is to have all the phosphors in the blend having the excitation peak at 400 nm or slightly shorter wavelength. This could lead to a white light source with no body color and optimum efficacy due to no self-absorption effects by phosphors in the blend. This is even harder than finding an ideal blue phosphor, but not necessarily impossible. 2) With the phosphor blends identified, light sources using nUV LEDs at high current could be designed with comparable efficacy to those using blue LEDs. It will allow us to design light sources with multiple wattages using the same chips and phosphor blends simply by varying the input current. In the case of blue LEDs, this is not currently possible because varying the current will lower the efficacy at high current and alter the color point. With improvement of phosphor blends, control over CRI could improve. Less binning at the chip level and also at the phosphor blend level could reduce the cost of SSL light sources. 3) This study provided a deeper understanding of phosphor characteristics needed for LEDs in general and nUV LEDs in particular. Two students received Ph.D. degrees and three

  15. Semi-intelligent trigger-generation scheme for Cherenkov light imaging cameras

    International Nuclear Information System (INIS)

    Bhat, C.L.; Tickoo, A.K.; Koul, R.; Kaul, I.K.

    1994-01-01

    We propose here an improved trigger-generation scheme for TeV gamma-ray imaging telescopes. Based on a memory-based Majority Coincidence Circuit, this scheme involves deriving two-or three-pixel nearest-neighbour coincidences as against the conventional approach of generating prompt coincidences using any two photomultiplier detector pixels of an imaging-camera. As such, the new method can discriminate better against shot-noise-generated triggers and, to a significant extent, also against cosmic-ray and local-muon-generated background events, without compromising on the telescope response to events of γ-ray origin. An optional feature of the proposed scheme is that a suitably scaled-up value of the chance-trigger rate can be independently derived, thereby making it possible to use this parameter reliably for keeping a log of the ''health'' of the experimental system. (orig.)

  16. Semi-intelligent trigger-generation scheme for Cherenkov light imaging cameras

    Science.gov (United States)

    Bhat, C. L.; Tickoo, A. K.; Koul, R.; Kaul, I. K.

    1994-02-01

    We propose here an improved trigger-generation scheme for TeV gamma-ray imaging telescopes. Based on a memory-based Majority Coincidence Circuit, this scheme involves deriving two- or three-pixel nearest-neighbour coincidences as against the conventional approach of generating prompt coincidences using any two photomultiplier detector pixels of an imaging-camera. As such, the new method can discriminate better against shot-noise-generated triggers and, to a significant extent, also against cosmic-ray and local-muon-generated background events, without compromising on the telescope response to events of γ-ray origin. An optional feature of the proposed scheme is that a suitably scaled-up value of the chance-trigger rate can be independently derived, thereby making it possible to use this parameter reliably for keeping a log of the ``health'' of the experimental system.

  17. Spectral tunability of two-photon states generated by spontaneous four-wave mixing: fibre tapering, temperature variation and longitudinal stress

    Science.gov (United States)

    Ortiz-Ricardo, E.; Bertoni-Ocampo, C.; Ibarra-Borja, Z.; Ramirez-Alarcon, R.; Cruz-Delgado, D.; Cruz-Ramirez, H.; Garay-Palmett, K.; U'Ren, A. B.

    2017-09-01

    We explore three different mechanisms designed to controllably tune the joint spectrum of photon pairs produced by the spontaneous four-wave mixing (SFWM) process in optical fibres. The first of these is fibre tapering, which exploits the modified optical dispersion resulting from reducing the core radius. We have presented a theory of SFWM for tapered fibres, as well as experimental results for the SFWM coincidence spectra as a function of the reduction in core radius due to tapering. The other two techniques that we have explored are temperature variation and application of longitudinal stress. While the maximum spectral shift observed with these two techniques is smaller than for fibre tapering, they are considerably simpler to implement and have the important advantage that they are based on the use of a single, suitably controlled, fibre specimen.

  18. Super-hydrophilic copper sulfide films as light absorbers for efficient solar steam generation under one sun illumination

    Science.gov (United States)

    Guo, Zhenzhen; Ming, Xin; Wang, Gang; Hou, Baofei; Liu, Xinghang; Mei, Tao; Li, Jinhua; Wang, Jianying; Wang, Xianbao

    2018-02-01

    Solar steam technology is one of the simplest, most direct and effective ways to harness solar energy through water evaporation. Here, we report the development using super-hydrophilic copper sulfide (CuS) films with double-layer structures as light absorbers for solar steam generation. In the double-layer structure system, a porous mixed cellulose ester (MCE) membrane is used as a supporting layer, which enables water to get into the CuS light absorbers through a capillary action to provide continuous water during solar steam generation. The super-hydrophilic property of the double-layer system (CuS/MCE) leads to a thinner water film close to the air-water interface where the surface temperature is sufficiently high, leading to more efficient evaporation (∼80 ± 2.5%) under one sun illumination. Furthermore, the evaporation efficiencies still keep a steady value after 15 cycles of testing. The super-hydrophilic CuS film is promising for practical application in water purification and evaporation as a light absorption material.

  19. Generation of light with controllable spatial patterns via the sum frequency in quasi-phase matching crystals

    Science.gov (United States)

    Zhou, Zhi-Yuan; Li, Yan; Ding, Dong-Sheng; Jiang, Yun-Kun; Zhang, Wei; Shi, Shuai; Shi, Bao-Sen; Guo, Guang-Can

    2014-07-01

    Light beams with extraordinary spatial structures, such as the Airy beam (AB), the Bessel-Gaussian beam (BGB) and the Laguerre-Gaussian beam (LGB), are widely studied and applied in many optical scenarios. We report on preparation of light beams with controllable spatial structures through sum frequency generation (SFG) using two Gaussian pump beams in a quasi-phase matching (QPM) crystal. The spatial structures, including multi-ring-like BGB, donut-like LGB, and super-Gaussian-like beams, can be controlled periodically via crystal phase mismatching by tuning the pump frequency or crystal temperature. This phenomenon has not been reported or discussed previously. Additionally, we present numerical simulations of the phenomenon, which agree very well with the experimental observations. Our findings give further insight into the SFG process in QPM crystals, provide a new way to generate light with unusual spatial structures, and may find applications in the fields of laser optics, all-optical switching, and optical manipulation and trapping.

  20. Sacrificial hydrogen generation from aqueous triethanolamine with Eosin Y-sensitized Pt/TiO2 photocatalyst in UV, visible and solar light irradiation.

    Science.gov (United States)

    Chowdhury, Pankaj; Gomaa, Hassan; Ray, Ajay K

    2015-02-01

    In this paper, we have studied Eosin Y-sensitized sacrificial hydrogen generation with triethanolamine as electron donor in UV, visible, and solar light irradiation. Aeroxide TiO2 was loaded with platinum metal via solar photo-deposition method to reduce the electron hole recombination process. Photocatalytic sacrificial hydrogen generation was influenced by several factors such as platinum loading (wt%) on TiO2, solution pH, Eosin Y to Pt/TiO2 mass ratio, triethanolamine concentration, and light (UV, visible and solar) intensities. Detailed reaction mechanisms in visible and solar light irradiation were established. Oxidation of triethanolamine and formaldehyde formation was correlated with hydrogen generation in both visible and solar lights. Hydrogen generation kinetics followed a Langmuir-type isotherm with reaction rate constant and adsorption constant of 6.77×10(-6) mol min(-1) and 14.45 M(-1), respectively. Sacrificial hydrogen generation and charge recombination processes were studied as a function of light intensities. Apparent quantum yields (QYs) were compared for UV, visible, and solar light at four different light intensities. Highest QYs were attained at lower light intensity because of trivial charge recombination. At 30 mW cm(-2) we achieved QYs of 10.82%, 12.23% and 11.33% in UV, visible and solar light respectively. Copyright © 2014 Elsevier Ltd. All rights reserved.

  1. Research on voltage characteristic of the third generation low-light-level image intensifier tube's output signal to noise ratio

    Science.gov (United States)

    Bai, Xiaofeng; Yin, Lei; Hu, Wen; Shi, Feng; Hou, Zhipeng; Shi, Hongli; He, Yingping

    2012-10-01

    Signal to noise ratio is an important parameter to evaluate the 3rd generation low-light-level image intensifier. In this article, voltage in different poles have been changed respectively, output signal to noise ratio referring to different voltages have been studied, and the relationship between each voltage and output signal to noise ratio has been analyzed. The study results show that voltage of photocathode is not less than 150 V, voltage of MCP is between 800 V and 900 V, and voltage of screen is between 5000 V and 6000 V while output signal to noise ratio of filmed image intensifier is optimized. The study in this article is worthwhile for developing signal to noise ratio of the 3rd low-light-level image intensifier sufficiently.

  2. Design and Fabrication of the Second-Generation KID-Based Light Detectors of CALDER

    Science.gov (United States)

    Colantoni, I.; Cardani, L.; Casali, N.; Cruciani, A.; Bellini, F.; Castellano, M. G.; Cosmelli, C.; D'Addabbo, A.; Di Domizio, S.; Martinez, M.; Tomei, C.; Vignati, M.

    2018-04-01

    The goal of the cryogenic wide-area light detectors with excellent resolution project is the development of light detectors with large active area and noise energy resolution smaller than 20 eV RMS using phonon-mediated kinetic inductance detectors (KIDs). The detectors are developed to improve the background suppression in large-mass bolometric experiments such as CUORE, via the double readout of the light and the heat released by particles interacting in the bolometers. In this work we present the fabrication process, starting from the silicon wafer arriving to the single chip. In the first part of the project, we designed and fabricated KID detectors using aluminum. Detectors are designed by means of state-of-the-art software for electromagnetic analysis (SONNET). The Al thin films (40 nm) are evaporated on high-quality, high-resistivity (> 10 kΩ cm) Si(100) substrates using an electron beam evaporator in a HV chamber. Detectors are patterned in direct-write mode, using electron beam lithography (EBL), positive tone resist poly-methyl methacrylate and lift-off process. Finally, the chip is diced into 20 × 20 mm2 chips and assembled in a holder OFHC (oxygen-free high conductivity) copper using PTFE support. To increase the energy resolution of our detectors, we are changing the superconductor to sub-stoichiometric TiN (TiN x ) deposited by means of DC magnetron sputtering. We are optimizing its deposition by means of DC magnetron reactive sputtering. For this kind of material, the fabrication process is subtractive and consists of EBL patterning through negative tone resist AR-N 7700 and deep reactive ion etching. Critical temperature of TiN x samples was measured in a dedicated cryostat.

  3. Astigmatism inducing the degenerate effect in nearly hemispherical cavities: generation of three-dimensional structured light

    Science.gov (United States)

    Tung, J. C.; Hsieh, Y. H.; Liang, H. C.; Su, K. W.; Huang, K. F.; Chen, Y. F.

    2017-04-01

    We originally perform an analytical form to explore the influence of the astigmatism on the degenerate effect in nearly hemispherical cavities. The frequency spectrum near hemispherical cavities clearly reveals that not only the difference of cavity lengths between each degeneracies but also frequency gaps have significant difference from non-hemispherical cavities. We further thoroughly demonstrate the laser experiment under the condition of nearly hemispherical cavities to confirm the theoretical exploration that the transverse topology of three-dimensional (3D) structured light in the degenerate cavities is well localized on the Lissajous curves.

  4. Generation of high-power blue light in periodically poled LiNbO3

    NARCIS (Netherlands)

    Ross, Graeme W.; Pollnau, Markus; Smith, Peter G.R.; Clarkson, W. Andrew; Britton, Paul E.; Hanna, David C.

    1998-01-01

    We report the generation of 450-mW average blue (473-nm) power by frequency doubling of a diode-pumped 946-nm Nd:YAG laser. We achieved pulsed operation at a high repetition rate (~160 kHz) by driving the relaxation oscillations of the laser. A 40% conversion efficiency to the second harmonic was

  5. Generation of electromagnetic pulses from plasma channels induced by femtosecond light strings

    OpenAIRE

    Cheng, Chung-Chieh; Wright, E. M.; Moloney, J. V.

    2000-01-01

    We present a model that elucidates the physics underlying the generation of an electromagnetic pulse from a femtosecond laser induced plasma channel. The radiation pressure force from the laser pulse spatially separates the ionized electrons from the heavier ions and the induced dipole moment subsequently oscillates at the plasma frequency and radiates an electromagnetic pulse.

  6. Human Detection Based on the Generation of a Background Image by Using a Far-Infrared Light Camera

    Directory of Open Access Journals (Sweden)

    Eun Som Jeon

    2015-03-01

    Full Text Available The need for computer vision-based human detection has increased in fields, such as security, intelligent surveillance and monitoring systems. However, performance enhancement of human detection based on visible light cameras is limited, because of factors, such as nonuniform illumination, shadows and low external light in the evening and night. Consequently, human detection based on thermal (far-infrared light cameras has been considered as an alternative. However, its performance is influenced by the factors, such as low image resolution, low contrast and the large noises of thermal images. It is also affected by the high temperature of backgrounds during the day. To solve these problems, we propose a new method for detecting human areas in thermal camera images. Compared to previous works, the proposed research is novel in the following four aspects. One background image is generated by median and average filtering. Additional filtering procedures based on maximum gray level, size filtering and region erasing are applied to remove the human areas from the background image. Secondly, candidate human regions in the input image are located by combining the pixel and edge difference images between the input and background images. The thresholds for the difference images are adaptively determined based on the brightness of the generated background image. Noise components are removed by component labeling, a morphological operation and size filtering. Third, detected areas that may have more than two human regions are merged or separated based on the information in the horizontal and vertical histograms of the detected area. This procedure is adaptively operated based on the brightness of the generated background image. Fourth, a further procedure for the separation and removal of the candidate human regions is performed based on the size and ratio of the height to width information of the candidate regions considering the camera viewing direction

  7. Generating high-peak-power structured lights in selectively pumped passively Q-switched lasers with astigmatic mode transformations

    Science.gov (United States)

    Chang, C. C.; Hsieh, Y. H.; Lee, C. Y.; Sung, C. L.; Tuan, P. H.; Tung, J. C.; Liang, H. C.; Chen, Y. F.

    2017-12-01

    Various high-order Hermite–Gaussian (HG) modes with high repetition rates and high peak powers are systematically generated by designing the cavity configuration to satisfy the criterion of the passive Q-switching. For the HG m,0 modes with the order m  =  1–9, the pulse repetition rate can exceed 100 kHz with peak power higher than 0.3 kW. For the HG m,m modes with the order m  =  1–10, the pulse repetition rate can be up to 37 kHz with peak power higher than 0.35 kW. Furthermore, the high-order HG beams is transformed by using an astigmatic mode converter to generate various structured lights with optical vortices. Experimental patterns of the transformed high-order HG beams in the propagation are theoretically analyzed and the phase structures are numerically manifested.

  8. Generation of broadband mid-IR and UV light in gas-filled single-ring hollow-core PCF.

    Science.gov (United States)

    Cassataro, Marco; Novoa, David; Günendi, Mehmet C; Edavalath, Nitin N; Frosz, Michael H; Travers, John C; Russell, Philip St J

    2017-04-03

    We report generation of an ultrafast supercontinuum extending into the mid- infrared in gas-filled single-ring hollow-core photonic crystal fiber (SR-PCF) pumped by 1.7 µm light from an optical parametric amplifier. The simple fiber structure offers shallow dispersion and flat transmission in the near and mid-infrared, enabling the generation of broadband spectra extending from 270 nm to 3.1 µm, with a total energy of a few µJ. In addition, we demonstrate the emission of ultraviolet dispersive waves whose frequency can be tuned simply by adjusting the pump wavelength. SR-PCF thus constitutes an effective means of compressing and delivering tunable ultrafast pulses in the near and mid-infrared spectral regions.

  9. Time delay generation at high frequency using SOA based slow and fast light.

    Science.gov (United States)

    Berger, Perrine; Bourderionnet, Jérôme; Bretenaker, Fabien; Dolfi, Daniel; Alouini, Mehdi

    2011-10-24

    We show how Up-converted Coherent Population Oscillations (UpCPO) enable to get rid of the intrinsic limitation of the carrier lifetime, leading to the generation of time delays at any high frequencies in a single SOA device. The linear dependence of the RF phase shift with respect to the RF frequency is theoretically predicted and experimentally evidenced at 16 and 35 GHz. © 2011 Optical Society of America

  10. Plasmas generated by ultra-violet light rather than electron impact

    Energy Technology Data Exchange (ETDEWEB)

    Franklin, R. N. [Department of Astronomy and Physics, The Open University, Milton Keynes MK7 6AA (United Kingdom); Allen, J. E. [University College, University of Oxford, Oxford OX1 4BH, United Kingdom and OCIAM, Mathematical Institute, University of Oxford, Oxford OX2 6GG (United Kingdom); Blackett Laboratory, Imperial College London, Prince Consort Road, London SW7 2BW (United Kingdom); Thomas, D. M. [Blackett Laboratory, Imperial College London, Prince Consort Road, London SW7 2BW (United Kingdom); Benilov, M. S. [Departamento de Fisica, CCCEE, Universidade de Madeira, Largo do Municipio, 9000 Funchal (Portugal)

    2013-12-15

    We analyze, in both plane and cylindrical geometries, a collisionless plasma consisting of an inner region where generation occurs by UV illumination, and an un-illuminated outer region with no generation. Ions generated in the inner region flow outwards through the outer region and into a wall. We solve for this system's steady state, first in the quasi-neutral regime (where the Debye length λ{sub D} vanishes and analytic solutions exist) and then in the general case, which we solve numerically. In the general case, a double layer forms where the illuminated and un-illuminated regions meet, and an approximately quasi-neutral plasma connects the double layer to the wall sheath; in plane geometry, the ions coast through the quasi-neutral section at slightly more than the Bohm speed c{sub s}. The system, although simple, therefore has two novel features: a double layer that does not require counter-streaming ions and electrons, and a quasi-neutral plasma where ions travel in straight lines with at least the Bohm speed. We close with a précis of our asymptotic solutions of this system, and suggest how our theoretical conclusions might be extended and tested in the laboratory.

  11. Fundamental Understanding of Crack Growth in Structural Components of Generation IV Supercritical Light Water Reactors

    Energy Technology Data Exchange (ETDEWEB)

    Iouri I. Balachov; Takao Kobayashi; Francis Tanzella; Indira Jayaweera; Palitha Jayaweera; Petri Kinnunen; Martin Bojinov; Timo Saario

    2004-11-17

    This work contributes to the design of safe and economical Generation-IV Super-Critical Water Reactors (SCWRs) by providing a basis for selecting structural materials to ensure the functionality of in-vessel components during the entire service life. During the second year of the project, we completed electrochemical characterization of the oxide film properties and investigation of crack initiation and propagation for candidate structural materials steels under supercritical conditions. We ranked candidate alloys against their susceptibility to environmentally assisted degradation based on the in situ data measure with an SRI-designed controlled distance electrochemistry (CDE) arrangement. A correlation between measurable oxide film properties and susceptibility of austenitic steels to environmentally assisted degradation was observed experimentally. One of the major practical results of the present work is the experimentally proven ability of the economical CDE technique to supply in situ data for ranking candidate structural materials for Generation-IV SCRs. A potential use of the CDE arrangement developed ar SRI for building in situ sensors monitoring water chemistry in the heat transport circuit of Generation-IV SCWRs was evaluated and proved to be feasible.

  12. Generation of the second harmonics of Bessel light beams in a KTP crystal

    International Nuclear Information System (INIS)

    Belyi, V N; Kazak, N S; Kondratyuk, N V; Khilo, N A; Shagov, A A

    1998-01-01

    Theoretical and experimental investigations were made of the characteristic features of doubling the frequency of Bessel light beams by the oe - e interaction in a KTP crystal. All possible and scalar interactions of plane-wave components of Bessel beams were observed experimentally. The spatial structure of the second harmonic in the far zone consisted of a central spot and a concentric ring. The diffraction divergence of the central beam was weak ( ∼ 1.7 mrad). The energy conversion efficiency was ∼ 21% for a Bessel beam, which was three times higher than the efficiency of conversion of the initial laser beam. A theoretical model was based on representation of the field of the second harmonic as a superposition of Bessel beams, which provided a correct description of the observed spatial and energy characteristics of the second harmonic. (nonlinear optical phenomena and devices)

  13. A Visible-Light-Active Heterojunction with Enhanced Photocatalytic Hydrogen Generation.

    Science.gov (United States)

    Adhikari, Shiba P; Hood, Zachary D; More, Karren L; Chen, Vincent W; Lachgar, Abdou

    2016-07-21

    A visible-light-active carbon nitride (CN)/strontium pyroniobate (SNO) heterojunction photocatalyst was fabricated by deposition of CN over hydrothermally synthesized SNO nanoplates by a simple thermal decomposition process. The microscopic study revealed that nanosheets of CN were anchored to the surface of SNO resulting in an intimate contact between the two semiconductors. Diffuse reflectance UV/Vis spectra show that the resulting CN/SNO heterojunction possesses intense absorption in the visible region. The structural and spectral properties endowed the CN/SNO heterojunction with remarkably enhanced photocatalytic activity. Specifically, the photocatalytic hydrogen evolution rate per mole of CN was found to be 11 times higher for the CN/SNO composite compared to pristine CN. The results clearly show that the composite photocatalyst not only extends the light absorption range of SNO but also restricts photogenerated charge-carrier recombination, resulting in significant enhancement in photocatalytic activity compared to pristine CN. The relative band positions of the composite allow the photogenerated electrons in the conduction band of CN to migrate to that of SNO. This kind of charge migration and separation leads to the reduction in the overall recombination rate of photogenerated charge carriers, which is regarded as one of the key factors for the enhanced activity. A plausible mechanism for the enhanced photocatalytic activity of the heterostructured composite is proposed based on observed activity, photoluminescence, time-resolved fluorescence emission decay, electrochemical impedance spectroscopy, and band position calculations. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Spontaneous pneumothorax in weightlifters.

    Science.gov (United States)

    Marnejon, T; Sarac, S; Cropp, A J

    1995-06-01

    Spontaneous pneumothorax is infrequently caused by strenuous exertion. To our knowledge there has only been one case of spontaneous pneumothorax associated with weightlifting reported in the medical literature. We describe three consecutive cases of spontaneous pneumothorax associated with weightlifting. We postulate that spontaneous pneumothorax in these patients may be secondary to improper breathing techniques. It is important that physicians and weight trainers be aware of the association between weight lifting and spontaneous pneumothorax and assure that proper instruction is given to athletes who work with weights.

  15. Blue-Violet Light Irradiation Dose Dependently Decreases Carotenoids in Human Skin, Which Indicates the Generation of Free Radicals

    Directory of Open Access Journals (Sweden)

    Staffan Vandersee

    2015-01-01

    Full Text Available In contrast to ultraviolet and infrared irradiation, which are known to facilitate cutaneous photoaging, immunosuppression, or tumour emergence due to formation of free radicals and reactive oxygen species, potentially similar effects of visible light on the human skin are still poorly characterized. Using a blue-violet light irradiation source and aiming to characterize its potential influence on the antioxidant status of the human skin, the cutaneous carotenoid concentration was measured noninvasively in nine healthy volunteers using resonance Raman spectroscopy following irradiation. The dose-dependent significant degradation of carotenoids was measured to be 13.5% and 21.2% directly after irradiation at 50 J/cm² and 100 J/cm² (P<0.05. The irradiation intensity was 100 mW/cm². This is above natural conditions; the achieved doses, though, are acquirable under natural conditions. The corresponding restoration lasted 2 and 24 hours, respectively. The degradation of cutaneous carotenoids indirectly shows the amount of generated free radicals and especially reactive oxygen species in human skin. In all volunteers the cutaneous carotenoid concentration dropped down in a manner similar to that caused by the infrared or ultraviolet irradiations, leading to the conclusion that also blue-violet light at high doses could represent a comparably adverse factor for human skin.

  16. In Situ Fluorine Doping of TiO2 Superstructures for Efficient Visible-Light Driven Hydrogen Generation.

    Science.gov (United States)

    Zhang, Peng; Tachikawa, Takashi; Fujitsuka, Mamoru; Majima, Tetsuro

    2016-03-21

    With the aid of breakthroughs in nanoscience and nanotechnology, it is imperative to develop metal oxide semiconductors through visible light-driven hydrogen generation. In this study, TiOF2 was incorporated as an n-type F-dopant source to TiO2 mesocrystals (TMCs) with visible-light absorption during the topotactic transformation. The crystal growth, structural change, and dynamic morphological evolution, from the initial intermediate NH4 TiOF3 to HTiOF3, TiOF2, and F-doped TMCs, were verified through in situ temperature-dependent techniques to elucidate the doping mechanism from intermediate TiOF2. The visible-light efficiencies of photocatalytic hydrogen were dependent on the contents of the dopant as compared with the pure TMC and a controled reference. Using femtosecond time-resolved diffuse reflectance spectroscopy, the charge-transfer dynamics were monitored to confirm the improvement of charge separation after doping. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. Generation of random mutants to improve light-use efficiency of Nannochloropsis gaditana cultures for biofuel production.

    Science.gov (United States)

    Perin, Giorgio; Bellan, Alessandra; Segalla, Anna; Meneghesso, Andrea; Alboresi, Alessandro; Morosinotto, Tomas

    2015-01-01

    The productivity of an algal culture depends on how efficiently it converts sunlight into biomass and lipids. Wild-type algae in their natural environment evolved to compete for light energy and maximize individual cell growth; however, in a photobioreactor, global productivity should be maximized. Improving light use efficiency is one of the primary aims of algae biotechnological research, and genetic engineering can play a major role in attaining this goal. In this work, we generated a collection of Nannochloropsis gaditana mutant strains and screened them for alterations in the photosynthetic apparatus. The selected mutant strains exhibited diverse phenotypes, some of which are potentially beneficial under the specific artificial conditions of a photobioreactor. Particular attention was given to strains showing reduced cellular pigment contents, and further characterization revealed that some of the selected strains exhibited improved photosynthetic activity; in at least one case, this trait corresponded to improved biomass productivity in lab-scale cultures. This work demonstrates that genetic modification of N. gaditana has the potential to generate strains with improved biomass productivity when cultivated under the artificial conditions of a photobioreactor.

  18. Real-time convolution method for generating light diffusion profiles of layered turbid media.

    Science.gov (United States)

    Kim, Hoe-Min; Ko, Kwang Hee; Lee, Kwan H

    2011-06-01

    In this paper we present a technique to obtain a diffusion profile of layered turbid media in real time by using the quasi fast Hankel transform (QFHT) and the latest graphics processing unit technique. We apply the QFHT to convolve the diffusion profiles of each layer so as to dramatically reduce the time for the convolution step while maintaining the accuracy. In addition, we also introduce an accelerated technique to generate individual discrete diffusion profiles for each layer through parallel processing. The proposed method is 2 orders of magnitude faster than the existing method, and we validate its efficiency by comparing it with Monte Carlo simulation and another relevant methods.

  19. Narrow-band laser amplifier system for tunable UV light generation

    International Nuclear Information System (INIS)

    Matsuoka, Leo; Hashimoto, Masashi; Yokoyama, Keiichi

    2013-01-01

    We developed a Ti:Sapphire narrow-band laser amplifier system for efficient third harmonic generation. The amplifier system was composed of a wavelength tunable narrow-band regenerative amplifier and a broadband multi-pass amplifier. With a pumping of ∼17 mJ by the second harmonics of a Nd:YLF laser, mode-locked seed pulses were amplified to ∼1.0 mJ at 1-kHz repetition. We obtained the third harmonic wave of ∼208-μJ pulse energy after the wavelength conversion by two β-BBO crystals. (author)

  20. Coherence-vortex lattice formed via Mie scattering of partially coherent light by several dielectric nanospheres.

    Science.gov (United States)

    Marasinghe, Madara L; Paganin, David M; Premaratne, Malin

    2011-03-15

    We previously demonstrated that Mie scattering of stationary partially coherent light by dielectric spheres generates coherence vortices. In this Letter, we demonstrate that a lattice of coherence vortices can be generated by Mie scattering of partially coherent electromagnetic waves by a system of three coplanar dielectric spheres. Spontaneous coherence-vortex creation and destruction is observed in our computer modeling of this system.

  1. Amplified spontaneous emission from ZnO in n-ZnO/ZnO nanodots-SiO(2) composite/p-AlGaN heterojunction light-emitting diodes.

    Science.gov (United States)

    Shih, Ying Tsang; Wu, Mong Kai; Li, Wei Chih; Kuan, Hon; Yang, Jer Ren; Shiojiri, Makoto; Chen, Miin Jang

    2009-04-22

    This study demonstrates amplified spontaneous emission (ASE) of the ultraviolet (UV) electroluminescence (EL) from ZnO at lambda~380 nm in the n-ZnO/ZnO nanodots-SiO(2) composite/p- Al(0.12)Ga(0.88)N heterojunction light-emitting diode. A SiO(2) layer embedded with ZnO nanodots was prepared on the p-type Al(0.12)Ga(0.88)N using spin-on coating of SiO(2) nanoparticles followed by atomic layer deposition (ALD) of ZnO. An n-type Al-doped ZnO layer was deposited upon the ZnO nanodots-SiO(2) composite layer also by the ALD technique. High-resolution transmission electron microscopy (HRTEM) reveals that the ZnO nanodots embedded in the SiO(2) matrix have diameters of 3-8 nm and the wurtzite crystal structure, which allows the transport of carriers through the thick ZnO nanodots-SiO(2) composite layer. The high quality of the n-ZnO layer was manifested by the well crystallized lattice image in the HRTEM picture and the low-threshold optically pumped stimulated emission. The low refractive index of the ZnO nanodots-SiO(2) composite layer results in the increase in the light extraction efficiency from n-ZnO and the internal optical feedback of UV EL into n-ZnO layer. Consequently, significant enhancement of the UV EL intensity and super-linear increase in the EL intensity, as well as the spectral narrowing, with injection current were observed owing to ASE in the n-ZnO layer.

  2. High Brightness Electron Guns for Next-Generation Light Sources and Accelerators

    International Nuclear Information System (INIS)

    H. Bluem; M.D. Cole; J. Rathke; T. Schultheiss; A.M.M. Todd; I. Ben-Zvi; T. Srinivasan-Rao; P. Colestock; D.C. Nguyen; R.L. Wood; L. Young; D. Janssen; J. Lewellen; G. Neil; H.L. Phillips; J.P. Preble

    2004-01-01

    Advanced Energy Systems continues to develop advanced electron gun and injector concepts. Several of these projects have been previously described, but the progress and status of each will be updated. The project closest to completion is an all superconducting RF (SRF) gun, being developed in collaboration with the Brookhaven National Laboratory, that uses the niobium of the cavity wall itself as the photocathode material. This gun has been fabricated and will shortly be tested with beam. The cavity string for a closely-coupled DC gun and SRF cavity injector that is expected to provide beam quality sufficient for proposed ERL light sources and FELs will be assembled at the Jefferson Laboratory later this year. We are also collaboration with Los Alamos on a prototype CW normal-conducting RF gun with similar performance, that will undergo thermal testing in late 2004. Another CW SRF gun project that uses a high quantum efficiency photocathode, similar to the FZ-Rossendorf approach, has just begun. Finally, we will present the RF design and cold test results for a fully axisymmetric, ultra-high-brightness x-band RF gun

  3. Diffusion voltage in polymer light emitting diodes measured with electric field induced second harmonic generation

    Energy Technology Data Exchange (ETDEWEB)

    Kristensen, P.K.; Rafaelsen, J.; Pedersen, T.G.; Pedersen, K. [Department of Physics and Nanotechnology, Aalborg University, Pontoppidanstraede 103, 9220 Aalborg East (Denmark)

    2005-12-01

    We apply electric field induced second harmonic (EFISH) to polymer light emitting diodes (PLEDs) and demonstrate the ability to determine the diffusion voltage in PLED devices. The EFISH signal is proportional to the square of the effective field, which is the sum of the diffusion voltage and the applied voltage. By minimizing the EFISH-signal as a function of the applied voltage, the diffusion voltage is determined by measuring the applied voltage that cancels out the diffusion voltage. The PLEDs are fabricated with indium tin oxide (ITO) as the hole injecting contact and two different electron injecting contacts, namely aluminum and calcium. The diffusion voltage originates from the rearranged charges caused by the difference in Fermi levels in the materials in the PLEDs. Different contacts will thus cause different diffusion voltages. We demonstrate here that the EFISH signal is proportional to the square of the effective field in both reverse and forward bias, and discuss the dependence on contact materials. (copyright 2005 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  4. Experimental and theoretical studies in non-linear optical applications. Fiber oscillatiors, regenerative amplifiers, simulations on white-light generation

    Energy Technology Data Exchange (ETDEWEB)

    Zia, Haider

    2015-12-15

    Compact and stable ultrafast laser sources for electron diffraction experiments are the first step in accomplishing the dream experiment of producing a molecular movie. This thesis work focuses on developing new robust laser sources to enable arbitrary scaling in laser repetition rate, pulse energy, duration and stability as needed to provide sufficient integrated detected electrons for high quality diffraction patterns that can be inverted to real space movies. In chapter 2, the construction of a novel stable and high power stretched pulse fiber oscillator outputting 300 mW at 31 MHz and compressible pulses to below 90 fs will be described. Chapter 3 describes the construction of a solid-state regenerative amplifier that was developed to achieve pulse energies above 1mJ with 0.40 mJ already achieved at 1 kHz. Novel simulation techniques were explored that aided the construction of the amplifier. Chapter 4 derives a new, fast and powerful numerical theory that is implemented for generalized non-linear Schrodinger equations in all spatial dimensions and time. This new method can model complicated terms in these equations that outperforms other numerical methods with respect to minimizing numerical error and increased speed. These advantages are due to this method's Fourier nature. A simulation tool was created, employing this numerical technique to simulate white-light generation in bulk media. The simulation matches extremely well with published experimental data, and is superior to the original simulation method used to match the experiment. The use of this tool enables accurate calculations of continuum or white light generation as needed for different experimental protocols and serves as the primary input to generate wide bandwidth coherent light.This work has solved the problem of predictably designing continuum generation within targeted wavelength ranges. This information is needed as part of an overall scheme in laser source development to coherently

  5. Experimental and theoretical studies in non-linear optical applications. Fiber oscillatiors, regenerative amplifiers, simulations on white-light generation

    International Nuclear Information System (INIS)

    Zia, Haider

    2015-12-01

    Compact and stable ultrafast laser sources for electron diffraction experiments are the first step in accomplishing the dream experiment of producing a molecular movie. This thesis work focuses on developing new robust laser sources to enable arbitrary scaling in laser repetition rate, pulse energy, duration and stability as needed to provide sufficient integrated detected electrons for high quality diffraction patterns that can be inverted to real space movies. In chapter 2, the construction of a novel stable and high power stretched pulse fiber oscillator outputting 300 mW at 31 MHz and compressible pulses to below 90 fs will be described. Chapter 3 describes the construction of a solid-state regenerative amplifier that was developed to achieve pulse energies above 1mJ with 0.40 mJ already achieved at 1 kHz. Novel simulation techniques were explored that aided the construction of the amplifier. Chapter 4 derives a new, fast and powerful numerical theory that is implemented for generalized non-linear Schrodinger equations in all spatial dimensions and time. This new method can model complicated terms in these equations that outperforms other numerical methods with respect to minimizing numerical error and increased speed. These advantages are due to this method's Fourier nature. A simulation tool was created, employing this numerical technique to simulate white-light generation in bulk media. The simulation matches extremely well with published experimental data, and is superior to the original simulation method used to match the experiment. The use of this tool enables accurate calculations of continuum or white light generation as needed for different experimental protocols and serves as the primary input to generate wide bandwidth coherent light.This work has solved the problem of predictably designing continuum generation within targeted wavelength ranges. This information is needed as part of an overall scheme in laser source development to coherently

  6. The Role of Next-Generation Sequencing in Sarcomas: Evolution From Light Microscope to Molecular Microscope.

    Science.gov (United States)

    Groisberg, Roman; Roszik, Jason; Conley, Anthony; Patel, Shreyaskumar R; Subbiah, Vivek

    2017-10-13

    Sarcomas are rare, heterogeneous group of soft tissue and bone tumors. Precise diagnosis of specific subtypes is challenging using conventional methods. Herein, we review the role of next-generation sequencing (NGS) technology that is used for rapid sequencing of DNA and RNA. Recent sarcoma specific studies recommend that molecular genetic testing should be added at diagnosis for appropriate clinical management in addition to diagnosis by expert pathologists. NGS has already been used to identify potentially actionable mutations, copy number alterations, and gene fusions. Rationally, choosing a drug based on an individual patient profile aka: "precision oncology" has been so far limited to few case reports in sarcomas. As we improve our ability to deliver personalized medicine using all modalities including conventional therapy, more patients may eventually benefit. As the cost and capacity of NGS outpace Moore's law, so does the probability of success.

  7. Next Generation Car — Example of Function Integration at the Light Urban Vehicle (LUV) Vehicle Concept

    Science.gov (United States)

    Kopp, G.; Brückmann, S.; Kriescher, M.; Friedrich, H. E.

    In times of climate change vehicle emissions have to be reduced clearly. One possibility is to reduce the mass of the body in white using lightweight sandwich structures. The department `Lightweight and Hybrid Design Methods' of the Institute of Vehicle Concepts develops a vehicle body structure by using sandwiches with aluminum top layers and polyurethane foam as core material. For that the foam and the sandwiches were investigated under different load cases, e.g. pressure loading and in-plane tests. In tests with components the high potential of the sandwich materials were shown. On the dynamic component test facility of the institute, vehicle front structures were tested successfully. The results of all investigations regarding sandwich materials, integration of functions (e.g. crash, thermal) in vehicle structures and the concept LUV are developed under the research program of Next Generation Car of the DLR. We will show the development and results of the LUV.

  8. Aging of secondary organic aerosol generated from the ozonolysis of α-pinene: effects of ozone, light and temperature

    Science.gov (United States)

    Denjean, C.; Formenti, P.; Picquet-Varrault, B.; Camredon, M.; Pangui, E.; Zapf, P.; Katrib, Y.; Giorio, C.; Tapparo, A.; Temime-Roussel, B.; Monod, A.; Aumont, B.; Doussin, J. F.

    2015-01-01

    A series of experiments was conducted in the CESAM (French acronym for Experimental Multiphasic Atmospheric Simulation Chamber) simulation chamber to investigate the evolution of the physical and chemical properties of secondary organic aerosols (SOAs) during different forcings. The present experiments represent a first attempt to comprehensively investigate the influence of oxidative processing, photochemistry, and diurnal temperature cycling upon SOA properties. SOAs generated from the ozonolysis of α-pinene were exposed under dry conditions (ozone concentrations, (2) light (under controlled temperature conditions) or (3) light and heat (6 °C light-induced temperature increase), and the resultant changes in SOA optical properties (i.e. absorption and scattering), hygroscopicity and chemical composition were measured using a suite of instrumentation interfaced to the CESAM chamber. The complex refractive index (CRI) was derived from integrated nephelometer measurements of 525 nm wavelength, using Mie scattering calculations and measured number size distributions. The particle size growth factor (GF) was measured with a hygroscopic tandem differential mobility analyzer (H-TDMA). An aerosol mass spectrometer (AMS) was used for the determination of the f44 / f43 and O : C ratio of the particles bulk. No change in SOA size or chemical composition was observed during O3 and light exposure at constant temperature; in addition, GF and CRI of the SOA remained constant with forcing. On the contrary, illumination of SOAs in the absence of temperature control led to an increase in the real part of the CRI from 1.35 (±0.03) to 1.49 (±0.03), an increase of the GF from 1.04 (±0.02) to 1.14 (±0.02) and an increase of the f44 / f43 ratio from 1.73 (±0.03) to 2.23 (±0.03). The simulation of the experiments using the master chemical mechanism (MCM) and the Generator for Explicit Chemistry and Kinetics of Organics in the Atmosphere (GECKO-A) shows that these changes resulted

  9. Linear microfocus bremsstrahlung generated in light and heavy narrow targets in B-18 betatron

    Science.gov (United States)

    Rychkov, M. M.; Kaplin, V. V.; Malikov, E. L.; Smolyanskiy, V. A.; Stepanov, I. B.; Lutsenko, A. S.; Gentsel'man, V.; Vas'kovskii, I. K.

    2017-08-01

    The first results of studying the properties of X- and G-ray beams generated at the grazing incidence of 18-MeV electrons with the 50 and 8-μm-thick Si crystals and a 13-μm-thick Ta foil of 4 mm in length along the electron beam are presented. The target has been placed in a goniometer inside the chamber of a B-18 betatron. The results exhibit strong changes in the angular distribution of radiation at the variation of the orientation of the target. This effect is not observed in the case of the normal incidence of electrons on the surface of a thin target. Images of a reference microstructure have been obtained with a high resolution of details of the microstructure owing to the smallness of the source of radiation. The dependence of the contrast of an image on the position of the microstructure in the radiation cone has been demonstrated, which is determined by the change in the effective size of the radiation source when the emission angle of the source is changed.

  10. Spontaneous Trait Inferences on Social Media.

    Science.gov (United States)

    Levordashka, Ana; Utz, Sonja

    2017-01-01

    The present research investigates whether spontaneous trait inferences occur under conditions characteristic of social media and networking sites: nonextreme, ostensibly self-generated content, simultaneous presentation of multiple cues, and self-paced browsing. We used an established measure of trait inferences (false recognition paradigm) and a direct assessment of impressions. Without being asked to do so, participants spontaneously formed impressions of people whose status updates they saw. Our results suggest that trait inferences occurred from nonextreme self-generated content, which is commonly found in social media updates (Experiment 1) and when nine status updates from different people were presented in parallel (Experiment 2). Although inferences did occur during free browsing, the results suggest that participants did not necessarily associate the traits with the corresponding status update authors (Experiment 3). Overall, the findings suggest that spontaneous trait inferences occur on social media. We discuss implications for online communication and research on spontaneous trait inferences.

  11. Production of 10.4 W of single frequency coherent light at 780 nm by second harmonic generation

    Science.gov (United States)

    Lichtman, Martin; Piotrowicz, Michal; Saffman, Mark

    2013-05-01

    We have developed a high power, 10.4 W single frequency source at 780 nm, using second harmonic generation in a double-pass arrangement through a 50 mm long PPLN crystal. The source power is from a 20 W erbium-doped fiber amplifier at 1560 nm, giving a conversion efficiency of 52%. Comparison of the conversion efficiency with calculations based on a modified Boyd-Kleinman theory and numerical solution of the non-linear Schrödinger equation will be presented. The 780 nm light is used to create an array of blue-detuned traps for quantum computing experiments with Cs atoms. This work was supported by IARPA through ARO and DARPA through AFOSR.

  12. 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.

  13. Influence of light energy density on heat generation during photoactivation of dental composites with different dentin and composite thickness

    Directory of Open Access Journals (Sweden)

    Ricardo Danil Guiraldo

    2009-08-01

    Full Text Available OBJECTIVE: The aim of this study was to determine the influence of different energy densities on the heat generated during photoactivation of Filtek Z250 (3M/ESPE and Z100 (3M/ESPE composite resins with different dentin and composite thickness. MATERIAL AND METHODS: The temperature increase was registered with a type-K thermocouple connected to a digital thermometer (Iopetherm 46. A chemically polymerized acrylic resin base was prepared to serve as a guide for the thermocouple and as a support for 0.5-, 1.0-, and 1.5-mm-thick bovine dentin discs. Circular elastomer molds (1.0 mm-height x 3.0-mm diameter or 2.0-mm height x 3.0-mm diameter were adapted on the acrylic resin base to standardize the composite resin thickness. A conventional halogen light-curing unit (XL 2500, 3M/ESPE was used with light intensity of 700 mW/cm². Energy density was calculated by the light intensity applied during a certain time with values of 28 J/cm² for Z100 and 14 J/cm² for Filtek Z250. The temperature change data were subjected to three-way ANOVA and Tukey's test at 5% level. RESULTS: The higher energy density (Z100 promoted greater temperature increase (p<0.05 than the lower energy density (Filtek Z250. For both composites and all composite thicknesses, the lowest dentin thickness (0.5 mm yielded significantly higher (p<0.05 temperature increase than the other two dentin thicknesses. The 1-mm-thick composite resin layer yielded significantly higher (p<0.05 temperature changes for both composites and all dentin thicknesses. CONCLUSIONS: Temperature increase was influenced by higher energy density and dentin/composite thickness.

  14. Beyond the Lambertian limit: Novel low-symmetry gratings for ultimate light trapping enhancement in next-generation photovoltaics

    Energy Technology Data Exchange (ETDEWEB)

    Birkmire, Robert [Univ. of Delaware, Newark, DE (United States); Hu, Juejun [Univ. of Delaware, Newark, DE (United States); Richardson, Kathleen [Univ. of Central Florida, Orlando, FL (United States). College of Optics and Photonics, Center for Research and Education in Optics and Lasers (CREOL)

    2016-05-20

    This project aims at addressing the efficiency limit and high fabrication cost of current light trapping methods by developing novel low-symmetry gratings (LSG) for next-generation thin c-Si photovoltaic (PV) cells. The LSG design achieves light trapping enhancement exceeding the 4n2 Lambertian limit and can be fabricated over large areas using low-cost, single-step nanoimprint techniques. We further explored the use of deposited high-refractive-index glass materials for low-temperature LSG processing, which enables direct imprint sculpting of even complex grating geometries in glass without requiring an additional pattern transfer step, which minimizes processing cost and surface damage to PV cells. In the project, we have demonstrated fabrication and integration of sub-wavelength LSG with thin c-Si wafers and bifacial solar cells with low defect density. Optical absorption measurements indicate that LSGs demonstrated superior absorption enhancement compared to their traditional symmetric counterparts as predicted by our simulations. Efficiency enhancement was observed in solar cells integrated with LSGs although fabrication yield of the LSG-integrated cells remains a challenge

  15. Nanostructured N-doped orthorhombic Nb2O5as an efficient stable photocatalyst for hydrogen generation under visible light.

    Science.gov (United States)

    Kulkarni, Aniruddha K; Praveen, C S; Sethi, Yogesh A; Panmand, Rajendra P; Arbuj, Sudhir S; Naik, Sonali D; Ghule, Anil V; Kale, Bharat B

    2017-11-07

    The synthesis of orthorhombic nitrogen-doped niobium oxide (Nb 2 O 5-x N x ) nanostructures was performed and a photocatalytic study carried out in their use in the conversion of toxic H 2 S and water into hydrogen under UV-Visible light. Nanostructured orthorhombic Nb 2 O 5-x N x was synthesized by a simple solid-state combustion reaction (SSCR). The nanostructural features of Nb 2 O 5-x N x were examined by FESEM and HRTEM, which showed they had a porous chain-like structure, with chains interlocked with each other and with nanoparticles sized less than 10 nm. Diffuse reflectance spectra depicted their extended absorbance in the visible region with a band gap of 2.4 eV. The substitution of nitrogen in place of oxygen atoms as well as Nb-N bond formation were confirmed by X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy. A computational study (DFT) of Nb 2 O 5-x N x was also performed for investigation and conformation of the crystal and electronic structure. N-Substitution clearly showed a narrowing of the band gap due to N 2p bands cascading above the O 2p band. Considering the band gap in the visible region, Nb 2 O 5-x N x exhibited enhanced photocatalytic activity toward hydrogen evolution (3010 μmol h -1 g -1 ) for water splitting and (9358 μmol h -1 g -1 ) for H 2 S splitting under visible light. The enhanced photocatalytic activity of Nb 2 O 5-x N x was attributed to its extended absorbance in the visible region due to its electronic structure being modified upon doping, which in turn generates more electron-hole pairs, which are responsible for higher H 2 generation. More significantly, the mesoporous nanostructure accelerated the supression of electron and hole recombination, which also contributed to the enhancement of its activity.

  16. Combining model and satellite data to investigate the effect of light absorbing impurities on snow melt and discharge generation

    Science.gov (United States)

    Matt, F.; Burkhart, J. F.

    2017-12-01

    Light absorbing impurities in snow and ice (LAISI) originating from atmospheric deposition enhance snow melt by increasing the absorption of solar radiation. The consequences are a shortening of the snow cover duration due to increased snow melt and, with respect to hydrologic processes, a temporal shift in the discharge generation. However, the effects as simulated in numerical models have large uncertainties. These uncertainties originate mainly from uncertainties in the wet and dry deposition of light absorbing aerosols, limitations in the model representation of the snowpack, and the lack of observable variables required to estimate model parameters. This leads to high uncertainties in the additional energy absorbed by the snow due to the presence of LAISI (the so called radiative forcing of LAISI), a key variable in understanding snowpack energy-balance dynamics. In this study, we present an approach combining distributed model simulations on the catchment scale and remotely sensed radiative forcing from LAISI in order to evaluate and improve model predictions. In a case study, we assess the effect of LAISI on snow melt and discharge generation in a high mountain catchment located in the western Himalaya using the distributed hydrologic model, Shyft. The snow albedo is hereby calculated from a radiative transfer model for snow, taking the increased absorption of solar radiation by LAISI into account. LAISI mixing ratios in snow are determined from atmospheric aerosol deposition rates. To asses the quality of our simulations, we model the instantaneous clear sky radiative forcing at MODIS overpass times, and compare it to the MODIS Dust Radiative Forcing in Snow (MODDRFS) satellite product. By scaling the deposition input to the model, we can optimize the simulated radiative forcing towards the satellite observations.

  17. Narrowband NIR-Induced In Situ Generation of the High-Energy Trans Conformer of Trichloroacetic Acid Isolated in Solid Nitrogen and its Spontaneous Decay by Tunneling to the Low-Energy Cis Conformer

    Directory of Open Access Journals (Sweden)

    R. F. G. Apóstolo

    2015-12-01

    Full Text Available The monomeric form of trichloroacetic acid (CCl3COOH; TCA was isolated in a cryogenic nitrogen matrix (15 K and the higher energy trans conformer (O=C–O–H dihedral: 180° was generated in situ by narrowband near-infrared selective excitation the 1st OH stretching overtone of the low-energy cis conformer (O=C–O–H dihedral: 0°. The spontaneous decay, by tunneling, of the generated high-energy conformer into the cis form was then evaluated and compared with those observed previously for the trans conformers of acetic and formic acids in identical experimental conditions. The much faster decay of the high-energy conformer of TCA compared to both formic and acetic acids (by ~35 and ca. 25 times, respectively was found to correlate well with the lower energy barrier for the trans→cis isomerization in the studied compound. The experimental studies received support from quantum chemistry calculations undertaken at the DFT(B3LYP/cc-pVDZ level of approximation, which allowed a detailed characterization of the potential energy surface of the molecule and the detailed assignment of the infrared spectra of the two conformers.

  18. Generated carrier dynamics in V-pit enhanced InGaN/GaN light emitting diode

    KAUST Repository

    Ajia, Idris A.

    2017-12-18

    We investigate the effects of V-pits on the optical properties of a state-of-the art highly efficient, blue InGaN/GaN multi-quantum-well (MQW) light emitting diode (LED) with high internal quantum efficiency (IQE) of > 80%. The LED is structurally enhanced by incorporating pre-MQW InGaN strain-relief layer with low InN content and patterned sapphire substrate. For comparison, a conventional (unenhanced) InGaN/GaN MQW LED (with IQE of 46%) grown under similar conditions was subjected to the same measurements. Scanning transmission electron microscopy (STEM) reveals the absence of V-pits in the unenhanced LED, whereas in the enhanced LED, V-pits with {10-11} facets, emerging from threading dislocations (TDs) were prominent. Cathodoluminescence mapping reveals the luminescence properties near the V-pits, showing that the formation of V-pit defects can encourage the growth of defect-neutralizing barriers around TD defect states. The diminished contribution of TDs in the MQWs allows indium-rich localization sites to act as efficient recombination centers. Photoluminescence and time-resolved spectroscopy measurements suggest that the V-pits play a significant role in the generated carrier rate and droop mechanism, showing that the quantum confined Stark effect is suppressed at low generated carrier density, after which the carrier dynamics and droop are governed by the carrier overflow effect.

  19. The (perceived) meaning of spontaneous thoughts.

    Science.gov (United States)

    Morewedge, Carey K; Giblin, Colleen E; Norton, Michael I

    2014-08-01

    Spontaneous thoughts, the output of a broad category of uncontrolled and inaccessible higher order mental processes, arise frequently in everyday life. The seeming randomness by which spontaneous thoughts arise might give people good reason to dismiss them as meaningless. We suggest that it is precisely the lack of control over and access to the processes by which they arise that leads people to perceive spontaneous thoughts as revealing meaningful self-insight. Consequently, spontaneous thoughts potently influence judgment. A series of experiments provides evidence supporting two hypotheses. First, we hypothesize that the more a thought is perceived to be spontaneous, the more it is perceived to provide meaningful self-insight. Participants perceived more spontaneous kinds of thought (e.g., intuition) to reveal greater self-insight than did more controlled kinds of thought in Study 1 (e.g., deliberation). In Studies 2 and 3, participants perceived thoughts with the same content and target to reveal greater self-insight when spontaneously rather than deliberately generated (i.e., childhood memories and impressions formed). Second, we hypothesize that the greater self-insight attributed to thoughts that are (perceived to be) spontaneous leads those thoughts to more potently influence judgment. Participants felt more sexually attracted to an attractive person whom they thought of spontaneously than deliberately in Study 4, and reported their commitment to a current romantic relationship would be more affected by the spontaneous rather than deliberate recollection of a good or bad experience with their romantic partner in Study 5. PsycINFO Database Record (c) 2014 APA, all rights reserved.

  20. Spontaneous uterine rupture

    African Journals Online (AJOL)

    ABSTRACT. Rupture of a gravid uterus is a surgical emergency. Predisposing factors include a scarred uterus. Spontaneous rupture of an unscarred uterus during pregnancy is a rare occurrence. We hereby present the case of a spontaneous complete uterine rupture at a gestational age of 34 weeks in a 35 year old patient ...

  1. Spontaneous intracranial hypotension.

    LENUS (Irish Health Repository)

    Fullam, L

    2012-01-31

    INTRODUCTION: Spontaneous\\/primary intracranial hypotension is characterised by orthostatic headache and is associated with characteristic magnetic resonance imaging findings. CASE REPORT: We present a case report of a patient with typical symptoms and classical radiological images. DISCUSSION: Spontaneous intracranial hypotension is an under-recognised cause of headache and can be diagnosed by history of typical orthostatic headache and findings on MRI brain.

  2. Next generation light robotic

    DEFF Research Database (Denmark)

    Villangca, Mark Jayson; Palima, Darwin; Banas, Andrew Rafael

    2017-01-01

    Conventional robotics provides machines and robots that can replace and surpass human performance in repetitive, difficult, and even dangerous tasks at industrial assembly lines, hazardous environments, or even at remote planets. A new class of robotic systems no longer aims to replace humans...

  3. Full in-vitro analyses of new-generation bulk fill dental composites cured by halogen light.

    Science.gov (United States)

    Tekin, Tuçe Hazal; Kantürk Figen, Aysel; Yılmaz Atalı, Pınar; Coşkuner Filiz, Bilge; Pişkin, Mehmet Burçin

    2017-08-01

    The objective of this study was to investigate the full in-vitro analyses of new-generation bulk-fill dental composites cured by halogen light (HLG). Two types' four composites were studied: Surefill SDR (SDR) and Xtra Base (XB) as bulk-fill flowable materials; QuixFill (QF) and XtraFill (XF) as packable bulk-fill materials. Samples were prepared for each analysis and test by applying the same procedure, but with different diameters and thicknesses appropriate to the analysis and test requirements. Thermal properties were determined by thermogravimetric analysis (TG/DTG) and differential scanning calorimetry (DSC) analysis; the Vickers microhardness (VHN) was measured after 1, 7, 15 and 30days of storage in water. The degree of conversion values for the materials (DC, %) were immediately measured using near-infrared spectroscopy (FT-IR). The surface morphology of the composites was investigated by scanning electron microscopes (SEM) and atomic-force microscopy (AFM) analyses. The sorption and solubility measurements were also performed after 1, 7, 15 and 30days of storage in water. In addition to his, the data were statistically analyzed using one-way analysis of variance, and both the Newman Keuls and Tukey multiple comparison tests. The statistical significance level was established at p<0.05. According to the ISO 4049 standards, all the tested materials showed acceptable water sorption and solubility, and a halogen light source was an option to polymerize bulk-fill, resin-based dental composites. Copyright © 2017 Elsevier B.V. All rights reserved.

  4. Present state of new technologies of nuclear power generation, and technological development of fast-breeder reactor and next-generation light water reactor

    International Nuclear Information System (INIS)

    Aoyagi, Toshihiro; Ando, Masato

    2014-01-01

    This paper introduces the present state of development of FBR in Japan and international cooperation, the development of HP-ABWR and HP-APWR as the next-generation light water reactors, and SMR development in the United States. As for FBR, the following situations are described: (1) history of development in Japan in the past, (2) history of change due to the readjustment of development plan caused by the accident of Fukushima Daiichi Nuclear Power Station, in which shift to FaCT phase 2 was suspended, and the approach to the establishment of safety standards for sodium-cooled FBR and its international standardization was adopted, and (3) future challenges. As for the Japan - France fast-breeder reactor development cooperation, the conclusion of the Japan - France inter-government agency agreement, and Japan's cooperation plan and system are described. Next, as for HP-ABWR and HP-APWR, the development goal and concept of each plant, and the element technologies required for the success are described. On the other hand, the small reactor development in the United States started with the aim of the securement of domestic technology base, contribution to reduction in carbon dioxide emissions, and its export to new entry countries for nuclear energy. This project aimed the practical use of SMR, and started 'financial support program for small reactors' to allocate about 452 million dollars to maximum two units of SMRs in the next five years. This project is outlined. (A.O.)

  5. Comparison of the Amount of Temperature Rise in the Pulp Chamber of Teeth Treated With QTH, Second and Third Generation LED Light Curing Units: An In Vitro Study.

    Science.gov (United States)

    Mahant, Rajesh Harivadanbhai; Chokshi, Shraddha; Vaidya, Rupal; Patel, Pruthvi; Vora, Asima; Mahant, Priyanka

    2016-01-01

    Introduction: This in vitro study was designed to measure and compare the amount of temperature rise in the pulp chamber of the teeth exposed to different light curing units (LCU), which are being used for curing composite restorations. Methods: The study was performed in two settings; first, an in vitro and second was mimicking an in vivo situation. In the first setup of the study, three groups were formed according to the respective three light curing sources. i.e. quartz-tungsten-halogen (QTH) unit and two light-emitting diode (LED) units (second and third generations). In the in vitro setting, direct thermal emission from three light sources at 3 mm and 6 mm distances, was measured with a k-type thermocouple, and connected to a digital thermometer. For a simulation of an in vivo situation, 30 premolar teeth were used. Class I Occlusal cavity of all the teeth were prepared and they were restored with incremental curing of composite, after bonding agent application. While curing the bonding agent and composite in layers, the intrapulpal temperature rise was simultaneously measured with a k-type thermocouple. Results: The first setting of the study showed that the heat produced by irradiation with LCU was significantly less at 6 mm distance when compared to 3 mm distance. The second setting of the study showed that the rise of intrapulpal temperature was significantly less with third generation LED light cure units than with second generation LED and QTH light cure units. Conclusion: As the distance from the light source increases, less irradiation heat is produced. Third generation LED lights cause the least temperature change in the pulp chamber of single rooted teeth.

  6. Efficient generation of 3.5W laser light at 515nm by frequency doubling a single-frequency high power DBR tapered diode laser

    DEFF Research Database (Denmark)

    Jensen, Ole Bjarlin; Hansen, Anders Kragh; Müller, André

    2017-01-01

    More than 3.5 W of green light at 515 nm is generated by frequency doubling a single-frequency high power DBR tapered diode laser. The frequency doubling is performed in a cascade of PPMgLN and PPMgSLT crystals in order to reach high power and avoid thermal effects present in PPMgLN at high power....... The green light is diffraction limited (M2

  7. White light generation via up-conversion and blue tone in Er3+/Tm3+/Yb3+-doped zinc-tellurite glasses

    Science.gov (United States)

    Rivera, V. A. G.; Ferri, F. A.; Nunes, L. A. O.; Marega, E.

    2017-05-01

    Yb3+, Er3+ and Tm3+ triply doped zinc-tellurite glass have been prepared containing up to 3.23 wt% of rare-earth ion oxides, were characterized by absorption spectroscopy, excitation, emission and up-conversion spectra. Transparent and homogeneous glasses have been produced, managing the red, green and blue emission bands, in order to generate white light considering the human eye perception. The energy transfer (resonant or non-resonant) between those rare-earth ions provides a color balancing mechanism that maintains the operating point in the white region, generating warm white light, cool white light and artificial daylight through the increase of the 976/980 nm diode laser excitation power from 4 to 470 mW. A light source at 4000 K is obtained under the excitation at 980 nm with 15 mW, providing a white light environment that is comfortable to the human eye vision. The spectroscopic study presented in this work describes the white light generation by the triply-doped zinc-tellurite glass, ranging from blue, green and red, by controlling the laser excitation power and wavelength at 976/980 nm. Such white tuning provokes healthy effects on human health throughout the day, especially the circadian system.

  8. Strongly Interacting Light Dark Matter

    Directory of Open Access Journals (Sweden)

    Sebastian Bruggisser, Francesco Riva, Alfredo Urbano

    2017-09-01

    Full Text Available In the presence of approximate global symmetries that forbid relevant interactions, strongly coupled light Dark Matter (DM can appear weakly coupled at small energy and generate a sizable relic abundance. Fundamental principles like unitarity restrict these symmetries to a small class, where the leading interactions are captured by effective operators up to dimension-8. Chiral symmetry, spontaneously broken global symmetries and non-linearly realized supersymmetry are examples of this. Their DM candidates (composite fermions, pseudo Nambu-Goldstone Bosons and Goldstini are interesting targets for LHC missing-energy searches.

  9. Strongly interacting light dark matter

    International Nuclear Information System (INIS)

    Bruggisser, Sebastian; Riva, Francesco; Urbano, Alfredo

    2016-07-01

    In the presence of approximate global symmetries that forbid relevant interactions, strongly coupled light Dark Matter (DM) can appear weakly coupled at small-energy and generate a sizable relic abundance. Fundamental principles like unitarity restrict these symmetries to a small class, where the leading interactions are captured by effective operators up to dimension-8. Chiral symmetry, spontaneously broken global symmetries and non-linearly realized supersymmetry are examples of this. Their DM candidates (composite fermions, pseudo-Nambu-Goldstone Bosons and Goldstini) are interesting targets for LHC missing-energy searches.

  10. Carbonate-based Janus micromotors moving in ultra-light acidic environment generated by HeLa cells in situ

    Science.gov (United States)

    Guix, Maria; Meyer, Anne K.; Koch, Britta; Schmidt, Oliver G.

    2016-02-01

    Novel approaches to develop naturally-induced drug delivery in tumor environments in a deterministic and controlled manner have become of growing interest in recent years. Different polymeric-based microstructures and other biocompatible substances have been studied taking advantage of lactic acidosis phenomena in tumor cells, which decrease the tumor extracellular pH down to 6.8. Micromotors have recently demonstrated a high performance in living systems, revealing autonomous movement in the acidic environment of the stomach or moving inside living cells by using acoustic waves, opening the doors for implementation of such smart microengines into living entities. The need to develop biocompatible motors which are driven by natural fuel sources inherently created in biological systems has thus become of crucial importance. As a proof of principle, we here demonstrate calcium carbonate Janus particles moving in extremely light acidic environments (pH 6.5), whose motion is induced in conditioned acidic medium generated by HeLa cells in situ. Our system not only obviates the need for an external fuel, but also presents a selective activation of the micromotors which promotes their motion and consequent dissolution in presence of a quickly propagating cell source (i.e. tumor cells), therefore inspiring new micromotor configurations for potential drug delivery systems.

  11. Generation of sinusoidal fringes with a holographic phase grating and a phase-only spatial light modulator

    International Nuclear Information System (INIS)

    Berberova, Natalia; Stoykova, Elena; Sainov, Ventseslav

    2012-01-01

    A variety of pattern projection methods for the three-dimensional capture of objects is based on the generation of purely sinusoidal fringes. This is not an easy task, especially when a portable non-interferometric system for outdoor usage is required. The use of phase gratings with coherent illumination as a possible solution has the advantage of providing good stability and a large measurement volume. In this work, we analyze the quality of fringes projected with two sinusoidal phase gratings. The first grating is recorded on a silver-halide holographic plate by means of a Michelson interferometer. The spatial resolution of the silver-halide material used is greater than 6000 lines per millimeter, and the recorded grating is practically analogous to a smooth variation of the phase profile. The second grating is formed as a sinusoidal phase variation on a liquid crystal-on-silicon phase-only reflective display with a resolution of 1920×1080 pixels, a pixel pitch of 8 μm and 256 phase levels. The frequency content of the fringes projected with both gratings is analyzed and compared on the basis of the calculated Fresnel diffraction pattern, taking into account that the sinusoidal phase distribution in the case of a spatial light modulator is both sampled and quantized. Experimental fringe patterns projected using both gratings are also provided.

  12. Need for spontaneous breakdown of chiral symmetry

    International Nuclear Information System (INIS)

    Salomone, A.; Schechter, J.; Tudron, T.

    1981-01-01

    The question of whether the chiral symmetry of the theory of strong interactions (with massless quarks) is required to be spontaneously broken is examined in the framework of a previously discussed effective Lagrangian for quantum chromodynamics. The assumption that physical masses of the theory be finite leads in a very direct way to the necessity of spontaneous breakdown. This result holds for all N/sub F/> or =2, where N/sub F/ is the number of different flavors of light quarks. The atypical cases N/sub F/ = 1,2 are discussed separately

  13. Spontaneous noncollinear second harmonic generation in GUHP

    Czech Academy of Sciences Publication Activity Database

    Kroupa, Jan; Fridrichová, M.

    2011-01-01

    Roč. 13, č. 3 (2011), s. 1-7 ISSN 2040-8978 R&D Projects: GA ČR GA203/09/0878 Institutional research plan: CEZ:AV0Z10100520 Keywords : nonlinear optics * scattering , polarization * nterference * crystal optics Subject RIV: BH - Optics, Masers, Lasers Impact factor: 1.573, year: 2011 http://iopscience.iop.org/2040-8986

  14. Dendritic multiporphyrin arrays as light-harvesting antennae: effects of generation number and morphology on intramolecular energy transfer.

    Science.gov (United States)

    Choi, Myung-Seok; Aida, Takuzo; Yamazaki, Tomoko; Yamazaki, Iwao

    2002-06-17

    A series of star- and cone-shaped dendritic multiporphyrin arrays, (nPZn)4PFB and (nPZn)1PFB, respectively, that contain energy-donating dendritic zinc porphyrin (PZn) wedges of different numbers (n = 1, 3, and 7) of the PZn units, attached to an energy-accepting free-base porphyrin (PFB) core, were synthesized by a convergent growth approach. For the cone-shaped series ((nPZn)1PFB), the efficiency of energy transfer (phi ENT) from the photoexcited PZn units to the focal PFB core, as evaluated from the fluorescence lifetimes of the PZn units, considerably decreased as the generation number increased: (1PZn)1PFB (86%), (3PZn)1PFB (66%), and (7PZn)1PFB (19%). In sharp contrast, the star-shaped series ((nPZn)4PFB) all showed high phi ENT values: (1PZn)4PFB (87%), (3PZn)4PFB (80%), and (7PZn)4PFB (71%). Energy transfer efficiencies of (3PZn)4-ester-PFB, (1PZn)4-ester-PFB, and (3PZn)1-ester-PFB, whose dendritic PZn wedges are connected by an ester linkage to the PFB core, were almost comparable to those of the corresponding ether-linked versions. Fluorescence depolarization (P) studies showed much lower P values for star-shaped (7PZn)4PFB and (3PZn)4PFB than cone-shaped (7PZn)1PFB and (3PZn)1PFB, respectively, indicating a highly efficient energy migration among the PZn units in the star-shaped series. Such a morphology-assisted photochemical event is probably responsible for the excellent light-harvesting activity of large (7PZn)4PFB molecules.

  15. Enhanced visible light generation in an active microcavity via third-harmonic conversion beyond the non-depletion approximation

    Science.gov (United States)

    Yu, Rong; Ding, Chunling; Wang, Jiangpeng; Zhang, Duo

    2017-12-01

    We explore the possibility of using an active doubly resonant microtoroid resonator to produce high-efficiency third-harmonic generation (THG) by exploiting optical third-order nonlinearity. In a microresonator, the active fundamental mode is coherently driven with a continuous-wave input laser at the telecommunication wavelength (1550 nm), and then, the visible THG signal (517 nm) is monitored via an individual bus waveguide. We thoroughly compare our results with those obtained from the conventional passive (i.e., loss) microtoroid resonator by a systematic analysis and detailed numerical simulations based on the Heisenberg-Langevin equations of motion. It is shown that the achievable THG spectrum features an ultralow critical input power. The THG power transmission can be significantly enhanced by about three orders of magnitude at a low input power of 0.1 μ W as compared with the obtained results in the passive microtoroid resonator THG system. Moreover, the THG efficiency can reach up to 100% with optical critical input power as low as a few microwatts. In turn, the analytical expressions of the critical intracavity intensity of the light in the microcavity, the critical input pump power, and the maximum THG efficiency are obtained. The enhanced THG power transmission and high conversion efficiency are attributed to a gain-induced loss compensation in the microtoroid resonator, reducing the effective loss felt by the resonator photons. With state-of-the art technologies in the field of solid-state resonators, including but not limited to microtoroids, the proposed THG scheme is experimentally realizable.

  16. Generation of shock fronts in the interaction of the short pulses of intense laser light in supercritical plasma

    International Nuclear Information System (INIS)

    Lopez V, V.E.

    2004-01-01

    The plasma is the state of the matter but diffused in the nature. The sun and the stars big heaps of hot plasma can be considered. The external surface of the terrestrial atmosphere this recovered by a layer of plasma. All gassy discharge (lightning spark arch etc.) this related with the formation of plasma. This way, 99 percent of our environment this formed almost of plasma. It is denominated plasma to the ionized gas in the one which all or most of the atoms have lost one or several of the electrons that belonged him, becoming positive ions and free electrons. In the plasma certain physical characteristics exist as for their behavior like they are the collective movements the quasi neutrality, the Debye length, the uncertainty etc. All these behaviors make that the study of the plasma is complex. For this they exist technical of numeric simulation joined to the technological advance of big computers of more capacity and prosecution speed. The simulation techniques of particles are those where a numeric code is built based on a model or theory of a system that it is wanted to investigate. This way through the simulation the results are compared with those theoretical predictions based on an analytic model. The applications of the physics of the plasma are multiple however we focus ourselves in the interaction laser-plasma. Both finish decades of investigation in the interaction of lasers with plasma they have been carried out in laboratories of Europe, Japan, United States. This studies concern the propagation of intense light laser in dense plasma homogeneous, the radiation absorption in cold plasma and problems related with the generation of suprathermal electrons among others. Other areas of the physics of the plasma-laser interaction that it has been considerable attention is the broadly well-known field as parametric uncertainties induced instabilities by the light and that they include the dispersions for example stimulated Raman and Brillouin being able to

  17. Spontaneous Atraumatic Mediastinal Hemorrhage

    Directory of Open Access Journals (Sweden)

    Morkos Iskander BSc, BMBS, MRCS, PGCertMedEd

    2013-04-01

    Full Text Available Spontaneous atraumatic mediastinal hematomas are rare. We present a case of a previously fit and well middle-aged lady who presented with acute breathlessness and an increasing neck swelling and spontaneous neck bruising. On plain chest radiograph, widening of the mediastinum was noted. The bruising was later confirmed to be secondary to mediastinal hematoma. This life-threatening diagnostic conundrum was managed conservatively with a multidisciplinary team approach involving upper gastrointestinal and thoracic surgeons, gastroenterologists, radiologists, intensivists, and hematologists along with a variety of diagnostic modalities. A review of literature is also presented to help surgeons manage such challenging and complicated cases.

  18. Enhanced two-channel nonlinear imaging by a highly polarized supercontinuum light source generated from a nonlinear photonic crystal fiber with two zero-dispersion wavelengths

    Science.gov (United States)

    Tao, Wei; Bao, Hongchun; Gu, Min

    2011-05-01

    Real-time monitoring the variation of chlorophyll distributions and cellular structures in leaves during plant growth provides important information for understanding the physiological statuses of plants. Two-photon-excited autofluorescence imaging and second harmonic generation imaging of leaves can be used for monitoring the nature intrinsic fluorophores distribution and cellular structures of leaves by the use of the near-infrared region of light which has minimal light absorption by endogenous molecules and thus increases tissue penetration. However, the two-photon absorption peak of intrinsic fluorophores of a ficus benjamina leaf is 50 nm away from the second harmonic generation excitation wavelength, which cannot be effectively excited by a femtosecond laser beam with one central wavelength. This paper shows that a highly polarized supercontinuum light generated from a birefringent nonlinear photonic crystal fiber with two zero-dispersion wavelengths can effectively excite two-photon autofluorescence as well as second harmonic generation signals for simultaneously monitoring intrinsic fluorophore distributions and non-centrosymmetric structures of leaves.

  19. Design and development of a new generation of UV-visible-light-driven nanosized codoped titanium dioxide photocatalysts and biocides/sporocides, and environmental applications

    Science.gov (United States)

    Hamal, Dambar B.

    For solar environmental remediation, a new generation of nanosized (activities for acetaldehyde degradation under visible light (wavelength > 420 nm). It was concluded that high visible-light-activities for acetaldehyde degradation over codoped titanium dioxide were attributed to an interplay of anatase crystallinity, high-surface area, reduced band-gap (activities of metal doped/codoped photocatalysts under UV light (wavelength pollutants. Indium demonstrated beneficial effects in both textural and photocatalytic properties. Gallium and indium codoped titanium dioxide photocatalysts displayed even better performance in the CO oxidation reaction under UV light. Notably, titanium dioxide codoped with Ga, In, and Pt, exhibited unique photoactivities for the CO oxidation under both UV and visible light irradiation, indicating that this system could have promise for the water-gas shift reaction for hydrogen production. Silver-based nanostructured titanium dioxide samples were developed for killing human pathogens (Escherichia coli cells and Bacillus subtilis spores). Biocidal tests revealed that silver, carbon, and sulfur codoped titanium dioxide nanoparticles (antimicrobial actions on both E. coli (logarithmic kill > 8) and B. subtilis spores (logarithmic kill > 5) for 30 minute exposures in dark conditions compared with Degussa P25. It was believed that the carbon and sulfur codoped titanium dioxide support and Ag species acted synergistically during deactivation of both E. coli and B. subtilis spores. Thus, titanium dioxide codoped with silver, carbon, sulfur can serve as a multifunctional generic biocide and a visible-light-active photocatalyst.

  20. Independent and arbitrary generation of spots in the 3D space domain with computer generated holograms written on a phase-only liquid crystal spatial light modulator

    International Nuclear Information System (INIS)

    Wang, Dong; Zhang, Jian; Xia, Yang; Wang, Hao

    2012-01-01

    An improved multiple independent iterative plane algorithm, based on a projection optimization idea, is proposed for the independent and arbitrary generation of one spot or multiple spots in a speckle-suppressed 3D work-area. Details of the mathematical expressions of the algorithm are given to theoretically show how it is improved for 3D spot generation. Both simulations and experiments are conducted to investigate the performance of the algorithm for independent and arbitrary 3D spot generation in several different cases. Simulation results agree well with experimental results, which validates the effectiveness of the algorithm proposed. Several additional experiments are demonstrated for fast and independent generation of four or more spots in the 3D space domain, which confirms the capabilities and practicalities of the algorithm further. (paper)

  1. Searching for light Higgs scalar boson in the next generation of electron-positron collider at LEP

    International Nuclear Information System (INIS)

    Chukwumah, G.C.

    1985-11-01

    The e + e - -collider facilities at LEP II, with the cm energy √S in the range 100-170 GeV may be able to detect ''light'' Higgs bosons, assuming a high luminosity. In this paper, we have calculated production cross-sections of a light Higgs boson H 0 in association with the neutral gauge boson Z 0 , for varying ranges of the cm energy expected to be available to LEP II and VLEEP (Novosibirsk) and for various values of the light Higgs mass. It is found out that production cross-sections are sizeable in comparison with those for the very massive Higgs bosons in proton-anti(proton) super-colliders, Tevatron, Spp-barS and SSC, respectively. The implication of this feature is pointed out. Further, prospects for light Higgs production in association with the charged gauge boson, W - in ultra energetic neutrino beams are examined. (author)

  2. Spontaneous Appendicocutaneous Fistula I

    African Journals Online (AJOL)

    M T0k0de* MB, BS and. Dr 0. A. AWOj0bi+ FMCS (Nig). ABSTRACT. Ruptured appendicitis is not a common cause of spontaneous enterocutaneous fistula. A case of ruptured retrocaecal appendicitis presenting as an enterocutaneous fistula in a Nigerian woman is presented. The literature on this disorder is also reviewed.

  3. Spontaneous Grammar Explanations.

    Science.gov (United States)

    Tjoo, Hong Sing; Lewis, Marilyn

    1998-01-01

    Describes one New Zealand university language teacher's reflection on her own grammar explanations to university-level students of Bahasa Indonesian. Examines form-focused instruction through the teacher's spontaneous answers to students' questions about the form of the language they are studying. The teacher's experiences show that it takes time…

  4. EDITORIAL SPONTANEOUS BACTERIAL PERITONITIS ...

    African Journals Online (AJOL)

    hi-tech

    Spontaneous bacterial peritonitis (SBP) frequent]y occurs in patients with liver cirrhosis and ascites. It is defined as an infection of previously sterile ascitic fluid without any demonstrable intrabdominal source of infection. It is now internationally agreed that a polymorphonuclear (PMN) cell count in the ascitic fluid of over 250 ...

  5. Generation of 3.5 W of diffraction-limited green light from SHG of a single tapered diode laser in a cascade of nonlinear crystals

    DEFF Research Database (Denmark)

    Hansen, Anders Kragh; Jensen, Ole Bjarlin; Sumpf, Bernd

    2014-01-01

    frequency conversion of infrared tapered diode lasers. Here, we describe the generation of 3.5 W of diffraction-limited green light from SHG of a single tapered diode laser, itself yielding 10 W at 1063 nm. This SHG is performed in single pass through a cascade of two PPMgO:LN crystals with re...... power of 3.5 W corresponds to a power enhancement greater than 2 compared to SHG in each of the crystals individually and is the highest visible output power generated by frequency conversion of a single diode laser. Such laser sources provide the necessary pump power for biophotonics applications...

  6. Long-term stable stacked CsPbBr3 quantum dot films for highly efficient white light generation in LEDs.

    Science.gov (United States)

    Song, Young Hyun; Yoo, Jin Sun; Kang, Bong Kyun; Choi, Seung Hee; Ji, Eun Kyung; Jung, Hyun Suk; Yoon, Dae Ho

    2016-12-01

    We report highly efficient ethyl cellulose with CsPbBr 3 perovskite QD films for white light generation in LED application. Ethyl cellulose with CsPbBr 3 quantum dots is applied with Sr 2 Si 5 N 8  : Eu 2+ red phosphor on an InGaN blue chip, achieving a highly efficient luminous efficacy of 67.93 lm W -1 under 20 mA current.

  7. Generation of circularly polarized radiation from a compact plasma-based extreme ultraviolet light source for tabletop X-ray magnetic circular dichroism studies

    Energy Technology Data Exchange (ETDEWEB)

    Wilson, Daniel; Rudolf, Denis, E-mail: d.rudolf@fz-juelich.de; Juschkin, Larissa [RWTH Aachen University, Experimental Physics of EUV, Steinbachstraße 15, 52074 Aachen (Germany); Forschungszentrum Jülich GmbH, Peter Grünberg Institut (PGI-9), JARA-FIT, 52425 Jülich (Germany); Weier, Christian; Adam, Roman; Schneider, Claus M. [Forschungszentrum Jülich GmbH, Peter Grünberg Institut (PGI-6), JARA-FIT, 52425 Jülich (Germany); Winkler, Gerrit; Frömter, Robert [Institut für Angewandte Physik, Universität Hamburg, Jungiusstraße 11, 20355 Hamburg (Germany); Danylyuk, Serhiy [RWTH Aachen University, Chair for Technology of Optical Systems, JARA-FIT, Steinbachstraße 15, 52074 Aachen (Germany); Bergmann, Klaus [Fraunhofer Institute for Laser Technology, Steinbachstrasse 15, 52074 Aachen (Germany); Grützmacher, Detlev [Forschungszentrum Jülich GmbH, Peter Grünberg Institut (PGI-9), JARA-FIT, 52425 Jülich (Germany)

    2014-10-15

    Generation of circularly polarized light in the extreme ultraviolet (EUV) spectral region (about 25 eV–250 eV) is highly desirable for applications in spectroscopy and microscopy but very challenging to achieve in a small-scale laboratory. We present a compact apparatus for generation of linearly and circularly polarized EUV radiation from a gas-discharge plasma light source between 50 eV and 70 eV photon energy. In this spectral range, the 3p absorption edges of Fe (54 eV), Co (60 eV), and Ni (67 eV) offer a high magnetic contrast often employed for magneto-optical and electron spectroscopy as well as for magnetic imaging. We simulated and designed an instrument for generation of linearly and circularly polarized EUV radiation and performed polarimetric measurements of the degree of linear and circular polarization. Furthermore, we demonstrate first measurements of the X-ray magnetic circular dichroism at the Co 3p absorption edge with a plasma-based EUV light source. Our approach opens the door for laboratory-based, element-selective spectroscopy of magnetic materials and spectro-microscopy of ferromagnetic domains.

  8. Theoretical analysis of hard x-ray generation by nonperturbative interaction of ultrashort light pulses with a metal

    Directory of Open Access Journals (Sweden)

    Jannick Weisshaupt

    2015-03-01

    Full Text Available The interaction of intense femtosecond pulses with metals allows for generating ultrashort hard x-rays. In contrast to plasma theories, tunneling from the target into vacuum is introduced as electron generation step, followed by vacuum acceleration in the laser field and re-entrance into the target to generate characteristic x-rays and Bremsstrahlung. For negligible space charge in vacuum, the Kα flux is proportional to the incident intensity and the wavelength squared, suggesting a strong enhancement of the x-ray flux by mid-infrared driving pulses. This prediction is in quantitative agreement with experiments on femtosecond Cu Kα generation.

  9. Theoretical analysis of hard x-ray generation by nonperturbative interaction of ultrashort light pulses with a metal.

    Science.gov (United States)

    Weisshaupt, Jannick; Juvé, Vincent; Holtz, Marcel; Woerner, Michael; Elsaesser, Thomas

    2015-03-01

    The interaction of intense femtosecond pulses with metals allows for generating ultrashort hard x-rays. In contrast to plasma theories, tunneling from the target into vacuum is introduced as electron generation step, followed by vacuum acceleration in the laser field and re-entrance into the target to generate characteristic x-rays and Bremsstrahlung. For negligible space charge in vacuum, the Kα flux is proportional to the incident intensity and the wavelength squared, suggesting a strong enhancement of the x-ray flux by mid-infrared driving pulses. This prediction is in quantitative agreement with experiments on femtosecond Cu Kα generation.

  10. Dynamic generation and coherent control of beating stationary light pulses by a microwave coupling field in five-level cold atoms

    Science.gov (United States)

    Bao, Qian-Qian; Zhang, Yan; Cui, Cui-Li; Meng, Shao-Ying; Fang, You-Wei; Tian, Xue-Dong

    2018-04-01

    We propose an efficient scheme for generating and controlling beating stationary light pulses in a five-level atomic sample driven into electromagnetically induced transparency condition. This scheme relies on an asymmetrical procedure of light storage and retrieval tuned by two counter-propagating control fields where an additional coupling field, such as the microwave field, is introduced in the retrieval stage. A quantum probe field, incident upon such an atomic sample, is first transformed into spin coherence excitation of the atoms and then retrieved as beating stationary light pulses exhibiting a series of maxima and minima in intensity due to the alternative constructive and destructive interference. It is convenient to control the beating stationary light pulses just by manipulating the intensity and detuning of the additional microwave field. This interesting phenomenon involves in fact the coherent manipulation of dark-state polaritons and could be explored to achieve the efficient temporal splitting of stationary light pulses and accurate measurement of the microwave intensity.

  11. Spontaneous healing of spontaneous coronary artery dissection.

    Science.gov (United States)

    Almafragi, Amar; Convens, Carl; Heuvel, Paul Van Den

    2010-01-01

    Spontaneous coronary artery dissection (SCAD) is a rare cause of acute coronary syndrome and sudden cardiac death. It should be suspected in every healthy young woman without cardiac risk factors, especially during the peripartum or postpartum periods. It is important to check for a history of drug abuse, collagen vascular disease or blunt trauma of the chest. Coronary angiography is essential for diagnosis and early management. We wonder whether thrombolysis might aggravate coronary dissection. All types of treatment (medical therapy, percutaneous intervention or surgery) improve the prognosis without affecting survival times if used appropriately according to the clinical stability and the angiographic features of the involved coronary arteries. Prompt recognition and targeted treatment improve outcomes. We report a case of SCAD in a young female free of traditional cardiovascular risk factors, who presented six hours after thrombolysis for ST elevation myocardial infarction. Coronary angiography showed a dissection of the left anterior descending and immediate branch. She had successful coronary artery bypass grafting, with complete healing of left anterior descending dissection.

  12. Exploiting light chains for the scalable generation and platform purification of native human bispecific IgG

    Science.gov (United States)

    Fischer, Nicolas; Elson, Greg; Magistrelli, Giovanni; Dheilly, Elie; Fouque, Nicolas; Laurendon, Amélie; Gueneau, Franck; Ravn, Ulla; Depoisier, Jean-François; Moine, Valery; Raimondi, Sylvain; Malinge, Pauline; Di Grazia, Laura; Rousseau, François; Poitevin, Yves; Calloud, Sébastien; Cayatte, Pierre-Alexis; Alcoz, Mathias; Pontini, Guillemette; Fagète, Séverine; Broyer, Lucile; Corbier, Marie; Schrag, Delphine; Didelot, Gérard; Bosson, Nicolas; Costes, Nessie; Cons, Laura; Buatois, Vanessa; Johnson, Zoe; Ferlin, Walter; Masternak, Krzysztof; Kosco-Vilbois, Marie

    2015-01-01

    Bispecific antibodies enable unique therapeutic approaches but it remains a challenge to produce them at the industrial scale, and the modifications introduced to achieve bispecificity often have an impact on stability and risk of immunogenicity. Here we describe a fully human bispecific IgG devoid of any modification, which can be produced at the industrial scale, using a platform process. This format, referred to as a κλ-body, is assembled by co-expressing one heavy chain and two different light chains, one κ and one λ. Using ten different targets, we demonstrate that light chains can play a dominant role in mediating specificity and high affinity. The κλ-bodies support multiple modes of action, and their stability and pharmacokinetic properties are indistinguishable from therapeutic antibodies. Thus, the κλ-body represents a unique, fully human format that exploits light-chain variable domains for antigen binding and light-chain constant domains for robust downstream processing, to realize the potential of bispecific antibodies. PMID:25672245

  13. 76 FR 43679 - FirstLight Hydro Generating Company; City of Norwich Department of Public Utilities; Notice of...

    Science.gov (United States)

    2011-07-21

    ...Light); and Competitor--City of Norwich Department of Public Utilities (Norwich Public Utilities). e... 06103. For Project No. 12968: John F. Bilda, General Manager, Norwich Public Utilities, 16 South Golden...'s proposal would increase capacity by 1.026 MW. Norwich Public Utilities' proposal would increase...

  14. Optomechanical design and construction of a vacuum-compatible optical parametric oscillator for generation of squeezed light.

    Science.gov (United States)

    Wade, A R; Mansell, G L; McRae, T G; Chua, S S Y; Yap, M J; Ward, R L; Slagmolen, B J J; Shaddock, D A; McClelland, D E

    2016-06-01

    With the recent detection of gravitational waves, non-classical light sources are likely to become an essential element of future detectors engaged in gravitational wave astronomy and cosmology. Operating a squeezed light source under high vacuum has the advantages of reducing optical losses and phase noise compared to techniques where the squeezed light is introduced from outside the vacuum. This will ultimately provide enhanced sensitivity for modern interferometric gravitational wave detectors that will soon become limited by quantum noise across much of the detection bandwidth. Here we describe the optomechanical design choices and construction techniques of a near monolithic glass optical parametric oscillator that has been operated under a vacuum of 10(-6) mbar. The optical parametric oscillator described here has been shown to produce 8.6 dB of quadrature squeezed light in the audio frequency band down to 10 Hz. This performance has been maintained for periods of around an hour and the system has been under vacuum continuously for several months without a degradation of this performance.

  15. [Characteristics of laser light].

    Science.gov (United States)

    Takac, S; Stojanović, S

    1999-01-01

    Laser is one of the greatest technical discoveries of the 20th century. It is important in basic sciences, but particularly in diagnosis and therapy of various pathologic conditions of human organism. It is electromagnetic radiation, not X-irradiation and, as such, it is not expected to produce new generation of iatrogenic malignancies. Laser falls between infrared and ultraviolet on the spectrum mainly in the visible light spectrum. Properties of laser light are: monochromacity (the same color), coherence (all of the light waves are in phase both spatially and temporally), collimation (all rays are parallel to each other and do not diverge significantly even over long distances). Lasers were first conceived by Einstein in 1917 when he wrote his "Zur Quantum Theorie der Strahlung" (the quantum theory of radiation) which enumerated concepts of stimulated and spontaneous emission and absorption. Drs. Arthur Schawlow and Charles Townes, in 1956, extended lasers into the optical frequency range and Maiman, in 1960, operated the first laser using ruby as the active medium (ruby laser). Laser is an acronym for Light Amplification by Stimulated Emission of Radiation. To understand the acronym, it is necessary to understand the basic physics of the atom. However, if the atom that is in the excited state is struck by another photon of energy before it returns to the ground state, two photons of equal frequency and energy, travelling in the same direction and in perfect spatial and temporal harmony, are produced. This phenomenon is termed stimulated emission of radiation. An external power source hyperexcites the atoms in the laser medium so that the number of atoms possessing upper energy levels exceeds the number of atoms in a power energy level, a condition termed a population inversion. This "pumping system" which imparts additional energy to the atoms may be optical, mechanical, or chemical. These atoms in a hyperexcited state spontaneously emit photons of light. The

  16. Spontaneous spinal epidural abscess.

    LENUS (Irish Health Repository)

    Ellanti, P

    2011-10-01

    Spinal epidural abscess is an uncommon entity, the frequency of which is increasing. They occur spontaneously or as a complication of intervention. The classical triad of fever, back pain and neurological symptoms are not always present. High index of suspicion is key to diagnosis. Any delay in diagnosis and treatment can have significant neurological consequences. We present the case of a previously well man with a one month history of back pain resulting from an epidural abscess.

  17. MoS{sub 2}-coated microspheres of self-sensitized carbon nitride for efficient photocatalytic hydrogen generation under visible light irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Gu, Quan [Key Laboratory of Applied Surface and Colloid Chemistry, Ministry of Education, School of Chemistry and Chemical Engineering, Shaanxi Normal University, Xi’an, 710062 (China); School of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798 (Singapore); Sun, Huaming; Xie, Zunyuan; Gao, Ziwei [Key Laboratory of Applied Surface and Colloid Chemistry, Ministry of Education, School of Chemistry and Chemical Engineering, Shaanxi Normal University, Xi’an, 710062 (China); Xue, Can, E-mail: cxue@ntu.edu.sg [School of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798 (Singapore)

    2017-02-28

    Highlights: • Successful coating of MoS{sub 2} onto self-sensitized carbon nitride microspheres. • The carbon nitride@MoS{sub 2} core-shell structure show enhanced H{sub 2} generation in visible light. • Synergistic effect of surface dyes and MoS{sub 2} coating enhances photocatalytic activities. - Abstract: We have successfully coated the self-sensitized carbon nitride (SSCN) microspheres with a layer of MoS{sub 2} through a facile one-pot hydrothermal method by using (NH{sub 4}){sub 2}MoS{sub 4} as the precursor. The resulted MoS{sub 2}-coated SSCN photocatalyst appears as a core-shell structure and exhibits enhanced visible-light activities for photocatalytic H{sub 2} generation as compared to the un-coated SSCN and the standard g-C{sub 3}N{sub 4} reference with MoS{sub 2} coating. The photocatalytic test results suggest that the oligomeric s-triazine dyes on the SSCN surface can provide additional light-harvesting capability and photogenerated charge carriers, and the coated MoS{sub 2} layer can serve as active sites for proton reduction towards H{sub 2} evolution. This synergistic effect of surface triazine dyes and MoS{sub 2} coating greatly promotes the activity of carbon nitride microspheres for vishible-light-driven H{sub 2} generation. This work provides a new way of future development of low-cost noble-metal-free photocatalysts for efficient solar-driven hydrogen production.

  18. Combining the catalytic enantioselective reaction of visible-light-generated radicals with a by-product utilization system.

    Science.gov (United States)

    Huang, Xiaoqiang; Luo, Shipeng; Burghaus, Olaf; Webster, Richard D; Harms, Klaus; Meggers, Eric

    2017-10-01

    We report an unusual reaction design in which a chiral bis-cyclometalated rhodium(iii) complex enables the stereocontrolled chemistry of photo-generated carbon-centered radicals and at the same time catalyzes an enantioselective sulfonyl radical addition to an alkene. Specifically, employing inexpensive and readily available Hantzsch esters as the photoredox mediator, Rh-coordinated prochiral radicals generated by a selective photoinduced single electron reduction are trapped by allyl sulfones in a highly stereocontrolled fashion, providing radical allylation products with up to 97% ee. The hereby formed fragmented sulfonyl radicals are utilized via an enantioselective radical addition to form chiral sulfones, which minimizes waste generation.

  19. Dye-sensitized MIL-101 metal organic frameworks loaded with Ni/NiO{sub x} nanoparticles for efficient visible-light-driven hydrogen generation

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Xin-Ling; Wang, Rong; Yuan, Yu-Peng, E-mail: yupengyuan@ahu.edu.cn, E-mail: cxue@ntu.edu.sg [School of Chemistry and Chemical Engineering, and Innovation Lab for Clean Energy and Green Catalysis, Anhui University, Hefei 230036 (China); Zhang, Ming-Yi [Key Laboratory for Photonic and Electronic Bandgap Materials, Ministry of Education, School of Physics and Electronic Engineering, Harbin Normal University, Harbin 150025 (China); Xue, Can, E-mail: yupengyuan@ahu.edu.cn, E-mail: cxue@ntu.edu.sg [Solar Fuels Lab, School of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798 (Singapore)

    2015-10-01

    The Ni/NiO{sub x} particles were in situ photodeposited on MIL-101 metal organic frameworks as catalysts for boosting H{sub 2} generation from Erythrosin B dye sensitization under visible-light irradiation. The highest H{sub 2} production rate of 125 μmol h{sup −1} was achieved from the system containing 5 wt. % Ni-loaded MIL-101 (20 mg) and 30 mg Erythrosin B dye. Moreover, the Ni/NiO{sub x} catalysts show excellent stability for long-term photocatalytic reaction. The enhancement on H{sub 2} generation is attributed to the efficient charge transfer from photoexcited dye to the Ni catalyst via MIL-101. Our results demonstrate that the economical Ni/NiO{sub x} particles are durable and active catalysts for photocatalytic H{sub 2} generation.

  20. Dye-sensitized MIL-101 metal organic frameworks loaded with Ni/NiOx nanoparticles for efficient visible-light-driven hydrogen generation

    Directory of Open Access Journals (Sweden)

    Xin-Ling Liu

    2015-10-01

    Full Text Available The Ni/NiOx particles were in situ photodeposited on MIL-101 metal organic frameworks as catalysts for boosting H2 generation from Erythrosin B dye sensitization under visible-light irradiation. The highest H2 production rate of 125 μmol h−1 was achieved from the system containing 5 wt. % Ni-loaded MIL-101 (20 mg and 30 mg Erythrosin B dye. Moreover, the Ni/NiOx catalysts show excellent stability for long-term photocatalytic reaction. The enhancement on H2 generation is attributed to the efficient charge transfer from photoexcited dye to the Ni catalyst via MIL-101. Our results demonstrate that the economical Ni/NiOx particles are durable and active catalysts for photocatalytic H2 generation.

  1. An adaptive-binning method for generating constant-uncertainty/constant-significance light curves with Fermi-LAT data

    International Nuclear Information System (INIS)

    Lott, B.; Escande, L.; Larsson, S.; Ballet, J.

    2012-01-01

    Here, we present a method enabling the creation of constant-uncertainty/constant-significance light curves with the data of the Fermi-Large Area Telescope (LAT). The adaptive-binning method enables more information to be encapsulated within the light curve than with the fixed-binning method. Although primarily developed for blazar studies, it can be applied to any sources. Furthermore, this method allows the starting and ending times of each interval to be calculated in a simple and quick way during a first step. The reported mean flux and spectral index (assuming the spectrum is a power-law distribution) in the interval are calculated via the standard LAT analysis during a second step. In the absence of major caveats associated with this method Monte-Carlo simulations have been established. We present the performance of this method in determining duty cycles as well as power-density spectra relative to the traditional fixed-binning method.

  2. Effect of reduced exposure times on the microhardness of nanocomposites polymerized by QTH and second-generation LED curing lights.

    Science.gov (United States)

    Marchan, S M; White, D; Smith, W A; Raman, V; Coldero, L; Dhuru, V

    2011-01-01

    This study investigated the effectiveness of polymerization of various curing regimes on five nanocomposite restorative materials—Z350, Grandio, Clearfil Majesty Esthetic, Ice and Tetric EvoCeram—by utilizing microhardness measurements. Five (n=5) disc-shaped specimens of each material were subjected to one of three curing regimes: curing with a halogen light for 20 seconds, curing with an LED light for 20 seconds and curing with an LED light for 10 seconds. Immediately following curing, hardness measurements were made with a Vickers indenter at five different locations on both the top and bottom surfaces of each disc. The mean for each surface was calculated. Data were analyzed using a one-way ANOVA and post-hoc Tukey HSD (α=0.05). The results demonstrated that among the Z350 composite samples, top and bottom microhardness values showed no statistical differences when cured with the halogen 20 second or LED 20 second regimes (p>0.05). Comparison of the top and bottom values of discs cured with the LED 10 second regime demonstrated significant differences (pGrandio samples cured with the halogen 20 second regime showed no statistical differences between top and bottom microhardness values (p>0.05); however, the bottom values of Grandio discs cured with the LED 20 second and 10 second regimes were significantly lower when compared with top surface values (p=0.001 and pGrandio, while they were adequate for curing Clearfil Majesty Esthetic, Ice and Tetric EvoCeram.

  3. Multiple shape light sources generated in LiNbO3 nonlinear photonic crystals with Sierpinski fractal superlattices

    Science.gov (United States)

    Ma, Boqin; Chen, Baoqin; Liu, Rongjuan; Li, Zhiyuan

    2015-08-01

    LiNbO3 nonlinear photonic crystals with two kinds of Sierpinski fractal superlattice structures, in which their domain walls are circle and square cylindrical surfaces for the second order, respectively, are successfully fabricated. Quasi-phase matching and nonlinear Čerenkov harmonics under pulse laser beams are measured. The spot- and line-shaped light sources are realized by quasi-phase matching harmonics. Ten kinds of spot-shaped outputs can be accomplished, in which the quasi-phase matching harmonic conversion efficiency for the fundamental wavelength 1.352 μm reaches 27%. A green line-shaped light source with expansion angle of about 3° is observed, which originates from the coexistence of imperfect collinear and non-collinear quasi-phase matching processes. In addition, the ring-shaped light sources of continuous wavebands from 425 nm to 675 nm are obtained by nonlinear Čerenkov harmonics. The optical properties of quasi-phase matching and Čerenkov harmonics in two kinds of crystals are highly similar to each other.

  4. White light generation through Zn(PO3)2 glass activated with Eu3+ and Dy3+

    International Nuclear Information System (INIS)

    Meza-Rocha, A.N.; Speghini, A.; Bettinelli, M.; Caldiño, U.

    2016-01-01

    A spectroscopic investigation of Zn(PO 3 ) 2 glass activated with Eu 3+ and Dy 3+ ions is carried out from photoluminescence data. White light emission is obtained in the glass phosphor, and it is due mainly to europium 5 D 0 → 7 F 2 and dysprosium 4 F 9/2 → 6 H 15/2,13/2 emissions, being Eu 3+ sensitized by Dy 3+ through a non-radiative energy transfer. Non-radiative energy transfer from Eu 3+ to Dy 3+ is also observed upon Eu 3+ excitation at 414 nm. An electric quadrupole–quadrupole interaction might be the dominant mechanism in the energy transfer among Dy 3+ and Eu 3+ ions, as it was revealed from decay time data. The tonality of the white phosphor can be shifted from neutral white (0.364, 0.387) of 4522 K, upon 348 nm excitation, to warm white (0.393, 0.394) of 3811 K, upon 445 nm excitation. Excitations at 348–445 nm range can be attained with InGaN based LED chips, so that Eu 3+ and Dy 3+ codoped Zn(PO 3 ) 2 glasses excited by these LED chips could be appropriated for solid state lighting technology as neutral and warm white light sources.

  5. MoS2-coated microspheres of self-sensitized carbon nitride for efficient photocatalytic hydrogen generation under visible light irradiation

    Science.gov (United States)

    Gu, Quan; Sun, Huaming; Xie, Zunyuan; Gao, Ziwei; Xue, Can

    2017-02-01

    We have successfully coated the self-sensitized carbon nitride (SSCN) microspheres with a layer of MoS2 through a facile one-pot hydrothermal method by using (NH4)2MoS4 as the precursor. The resulted MoS2-coated SSCN photocatalyst appears as a core-shell structure and exhibits enhanced visible-light activities for photocatalytic H2 generation as compared to the un-coated SSCN and the standard g-C3N4 reference with MoS2 coating. The photocatalytic test results suggest that the oligomeric s-triazine dyes on the SSCN surface can provide additional light-harvesting capability and photogenerated charge carriers, and the coated MoS2 layer can serve as active sites for proton reduction towards H2 evolution. This synergistic effect of surface triazine dyes and MoS2 coating greatly promotes the activity of carbon nitride microspheres for vishible-light-driven H2 generation. This work provides a new way of future development of low-cost noble-metal-free photocatalysts for efficient solar-driven hydrogen production.

  6. Coherent generation and dynamic manipulation of double stationary light pulses in a five-level double-tripod system of cold atoms

    International Nuclear Information System (INIS)

    Bao Qianqian; Zhang Xiaohang; Gao Junyan; Zhang Yan; Cui Cuili; Wu Jinhui

    2011-01-01

    We study a five-level double-tripod system of cold atoms for efficiently manipulating the dynamic propagation and evolution of a quantum probe field by modulating four classical control fields. Our numerical results show that it is viable to transform the quantum probe field into a pair of two-color stationary light pulses mutually coupled through two wave packets of atomic spin coherence. The pair of stationary light pulses can be released either from the sample entrance and exit synchronously or just from the sample exit with a controlled time delay. In addition, the two-color stationary light pulses are immune to the fast decay originating from the higher-order Fourier components of atomic spin and optical coherence, and may exhibit the quantum limited beating signals with their characteristic frequency determined by detunings of the four classical control fields. These results could be explored to design novel photonic devices, such as optical routing, beam splitter, and beat generator, for manipulating a quantum light field.

  7. An evaluation of light water breeder reactor system (LWBR) as an alternative for nuclear power generation in Brazil

    International Nuclear Information System (INIS)

    Sauer, I.L.

    1981-01-01

    The LWBR system as an alternative for nuclear power generation in Brazil, was technically and economically evaluated. The LWBR system has been characterized comparatively with the Pressurized Water Reactors through technological and investment cost analysis and through the analysis of the processes and unit costs of the fuel cycle stages. The characteristics of the LWBR system in comparison to the PWR system, with respect to utilization and cumulative consumption of uranium and thorium resources, fuel cycle processes and associated costs have been determined for possible alternatives of nuclear power participation in the Brazilian hidro-thermal electricity generating system. The analysis concluded that the LWBR system does not represent an attractive alternative for nuclear power generation in Brazil and even has no potential to compete with conventional Pressurized Water Reactors. (Author) [pt

  8. Photonics at the frontiers. Generation of few-cycle light pulses via NOPCPA and real-time probing of charge transfer in hybrid photovoltaics

    Energy Technology Data Exchange (ETDEWEB)

    Herrmann, Daniel

    2011-11-11

    In the first part of this thesis the methodics of the non-collinear, optically parametric amplification of chirped light pulses (NOPCPA) for the generation of few-cycle light pulses in the visible (Vis) and near infrared (NIR) with of 5-8 fs half-width are essential further developed. Fundamental parametric influences, like the existence of a parametrically induced phase and the generation of optically parametric fluorescence (OPF), are studied both by theoretical analyses and numerical simulations and by concrete experiments. Experimentally in the framework of this thesis fwe-cycle light pulses with a pulse width of 7.9 fs, 130 mJ energy, at 805 nm central wavelength and a very high seed-pulse-limited prepulse contrast of 11 and 8 orders of magnitude are reached at 30 ps and approximately 3 ps. One the one hand it has been succeeded to accelerate with the broad-band pulse amplifier quasi-monoenergetic electrons with energies of up to 50 MeV. For this the light pulse is focussed to relativistic intensities of several W/cm{sup 2} in a helium gas jet. On the other hand XUV light was produced up to the 20th harmonic of the generated light pulse from the broad-band pulse amplifier by its sub-cycle interaction with solid surfaces. In the framework of this thesis furthermore new, extended concepts for still broader-band NOPCPA over one octave were developed and characterized, which contain the application of two pump pulses in one NOPCPA stage and the application of two different pump wavelength in two subsequent NOPCPA stages. In the second part of this thesis broad-band white-light spectra and by means of NOPCPA spectrally tunable light pulses are applied in order to realize a transient absorption spectrometer with multichannel detection. This new excitation-query construction combines a very broad-band UV-Vis-NIR query with a high time resolution of 40 fs and high sensitivity for the transient change of the optical density of less than 10{sup -4}. By this it has in

  9. Reconsidering the European regulation of merchant transmission investment in light of the third energy package: The role of dominant generators

    International Nuclear Information System (INIS)

    Hauteclocque, Adrien de; Rious, Vincent

    2011-01-01

    The regulation of merchant transmission investment (MTI) has become an important issue in the EU electricity sector, subsequent to the granting of authorizations by European authorities to five merchant projects: BritNed, Estlink, the East West Cables, NorGer and recently a merchant line connecting Italy and Austria. The creation of a new Agency for the Cooperation of Energy Regulators (ACER) at the EU level, which has decision-making powers on MTI, therefore presents a unique opportunity to question and re-design the current European policy. This paper shows that the recent decisions concerning MTI may suffer a strong bias against dominant electricity generators while incumbent Transmission System Operators (TSOs) or new entrant TSOs are generally favored by national regulators and the European Commission (EC). This strategy is misguided as it fails to recognize both the new incentives of generators to develop MTI and the conflict of interest between the regulated and non-regulated activities of incumbent TSOs. Letting dominant generators undertake MTI is indeed generally beneficial as long as potential abuses of dominance are mitigated. To deter possible anti-competitive effects, we propose a new and feasible allocation of regulatory powers based on a clear demarcation between the market monitoring powers of ACER and the antitrust powers of the EC. - Highlights: → We compare TSOs and generators as merchant transmission investors in Europe. → We find a bias among regulators against the involvement of generators. → The conflict of interest with the regulated activities of TSOs is under-estimated. → Investment by generators is preferable provided market manipulation is deterred. → We propose a new allocation of regulatory powers to make it possible.

  10. Generation of more than 300 mW diffraction-limited light at 405 nm by second-harmonic generation of a tapered diode laser with external cavity feedback

    DEFF Research Database (Denmark)

    Jensen, Ole Bjarlin; Holm, J.; Sumpf, B.

    2007-01-01

    We have constructed a blue laser source consisting of a single-frequency tapered diode laser with external cavity feedback that is frequency doubled by a quasi-phase matched KTP (PPKTP) in a bowtie ring cavity and extract more than 360 mW of power at 405 nm. The conversion efficiency from fundame...... fundamental laser power to second harmonic power is 35 %, while it is 64 % from coupled fundamental power to extracted blue light. Thermal effects and gray tracking set an upper limit on the amount of generated blue light.......We have constructed a blue laser source consisting of a single-frequency tapered diode laser with external cavity feedback that is frequency doubled by a quasi-phase matched KTP (PPKTP) in a bowtie ring cavity and extract more than 360 mW of power at 405 nm. The conversion efficiency from...

  11. Spontaneous sensorimotor coupling with multipart music.

    Science.gov (United States)

    Hurley, Brian K; Martens, Peter A; Janata, Petr

    2014-08-01

    Music often evokes spontaneous movements in listeners that are synchronized with the music, a phenomenon that has been characterized as being in "the groove." However, the musical factors that contribute to listeners' initiation of stimulus-coupled action remain unclear. Evidence suggests that newly appearing objects in auditory scenes orient listeners' attention, and that in multipart music, newly appearing instrument or voice parts can engage listeners' attention and elicit arousal. We posit that attentional engagement with music can influence listeners' spontaneous stimulus-coupled movement. Here, 2 experiments-involving participants with and without musical training-tested the effect of staggering instrument entrances across time and varying the number of concurrent instrument parts within novel multipart music on listeners' engagement with the music, as assessed by spontaneous sensorimotor behavior and self-reports. Experiment 1 assessed listeners' moment-to-moment ratings of perceived groove, and Experiment 2 examined their spontaneous tapping and head movements. We found that, for both musically trained and untrained participants, music with more instruments led to higher ratings of perceived groove, and that music with staggered instrument entrances elicited both increased sensorimotor coupling and increased reports of perceived groove. Although untrained participants were more likely to rate music as higher in groove, trained participants showed greater propensity for tapping along, and they did so more accurately. The quality of synchronization of head movements with the music, however, did not differ as a function of training. Our results shed new light on the relationship between complex musical scenes, attention, and spontaneous sensorimotor behavior.

  12. Spontaneous Thigh Compartment Syndrome

    Directory of Open Access Journals (Sweden)

    Khan, Sameer K

    2011-02-01

    Full Text Available A young man presented with a painful and swollen thigh, without any history of trauma, illness, coagulopathic medication or recent exertional exercise. Preliminary imaging delineated a haematoma in the anterior thigh, without any fractures or muscle trauma. Emergent fasciotomies were performed. No pathology could be identified intra-operatively, or on follow-up imaging. A review of thigh compartment syndromes described in literature is presented in a table. Emergency physicians and traumatologists should be cognisant of spontaneous atraumatic presentations of thigh compartment syndrome, to ensure prompt referral and definitive management of this limb-threatening condition. [West J Emerg Med. 2011;12(1:134-138].

  13. 75 FR 55317 - FirstLight Hydro Generating Company; City of Norwich Department of Public Utilities; Notice of...

    Science.gov (United States)

    2010-09-10

    ... Utilities (Norwich Public Utilities). e. Name of Project: Scotland Hydroelectric Project. f. Location: On..., Hartford, CT 06103. For Project No. 12968: John F. Bilda, General Manager, Norwich Public Utilities, 16... turbine and generator in the existing powerhouse. Norwich Public Utilities' proposal would increase...

  14. Nonclassical photon streams using rephased amplified spontaneous emission

    International Nuclear Information System (INIS)

    Ledingham, Patrick M.; Naylor, William R.; Longdell, Jevon J.; Beavan, Sarah E.; Sellars, Matthew J.

    2010-01-01

    We present a fully quantum mechanical treatment of optically rephased photon echoes. These echoes exhibit noise due to amplified spontaneous emission; however, this noise can be seen as a consequence of the entanglement between the atoms and the output light. With a rephasing pulse one can get an 'echo' of the amplified spontaneous emission, leading to light with nonclassical correlations at points separated in time, which is of interest in the context of building wide bandwith quantum repeaters. We also suggest a wideband version of DLCZ protocol based on the same ideas.

  15. WOW: light print, light propel, light point

    DEFF Research Database (Denmark)

    Glückstad, Jesper; Bañas, Andrew Rafael; Aabo, Thomas

    2012-01-01

    We are presenting so-called Wave-guided Optical Waveguides (WOWs) fabricated by two-photon polymerization and capable of being optically manipulated into any arbitrary orientation. By integrating optical waveguides into the structures we have created freestanding waveguides which can be positioned...... 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...

  16. Spontaneous Tumor Lysis Syndrome

    Directory of Open Access Journals (Sweden)

    Alicia C. Weeks MD

    2015-08-01

    Full Text Available Tumor lysis syndrome (TLS is a known complication of malignancy and its treatment. The incidence varies on malignancy type, but is most common with hematologic neoplasms during cytotoxic treatment. Spontaneous TLS is thought to be rare. This case study is of a 62-year-old female admitted with multisystem organ failure, with subsequent diagnosis of aggressive B cell lymphoma. On admission, laboratory abnormalities included renal failure, elevated uric acid (20.7 mg/dL, and 3+ amorphous urates on urinalysis. Oliguric renal failure persisted despite aggressive hydration and diuretic use, requiring initiation of hemodialysis prior to chemotherapy. Antihyperuricemic therapy and hemodialysis were used to resolve hyperuricemia. However, due to multisystem organ dysfunction syndrome with extremely poor prognosis, the patient ultimately expired in the setting of a terminal ventilator wean. Although our patient did not meet current TLS criteria, she required hemodialysis due to uric acid nephropathy, a complication of TLS. This poses the clinical question of whether adequate diagnostic criteria exist for spontaneous TLS and if the lack of currently accepted guidelines has resulted in the underestimation of its incidence. Allopurinol and rasburicase are commonly used for prevention and treatment of TLS. Although both drugs decrease uric acid levels, allopurinol mechanistically prevents formation of the substrate rasburicase acts to solubilize. These drugs were administered together in our patient, although no established guidelines recommend combined use. This raises the clinical question of whether combined therapy is truly beneficial or, conversely, detrimental to patient outcomes.

  17. Direct probing of charge carrier behavior in multilayered organic light-emitting diode devices by time-resolved electric-field-induced sum-frequency generation spectroscopy

    Science.gov (United States)

    Miyamae, Takayuki; Takada, Noriyuki; Ohata, Hiroshi; Tsutsui, Tetsuo

    2017-10-01

    Time-resolved electric-field-induced sum-frequency generation (EFI-SFG) spectroscopy was employed to study the charge behavior of multilayer organic light-emitting diodes (OLEDs). Through application of the square wave pulse bias to the OLEDs, compensation for the polarization charges in the electron transport layer and the generation of 4,4‧-bis[N-(1-naphthyl-N-phenylamino)-biphenyl] (α-NPD) cations were observed. When the pulse voltage was turned off, the α-NPD cations immediately disappeared, confirming that charge recombination occurs at the interfaces. We therefore concluded that time-resolved EFI-SFG is useful for directly probing the carrier behavior in OLEDs in addition to identifying the origin of the charge carriers present in OLEDs.

  18. RBS analysis of ions implanted in light substrates exposed to hot plasmas laser-generated at PALS

    Czech Academy of Sciences Publication Activity Database

    Torrisi, L.; Gammino, S.; Picciotto, A.; Wolowski, J.; Krása, Josef; Láska, Leoš; Calcagnile, L.; Quarta, G.

    2005-01-01

    Roč. 160, 10-12 (2005), s. 685-695 ISSN 1042-0150. [Workshop PIBHI 2005 /2./. Giardini Naxos, 08.06.06-11.06.06] R&D Projects: GA MŠk(CZ) LC528 Institutional research plan: CEZ:AV0Z10100523 Keywords : RBS analysis * ion implantation * plasma-generated by lasers Subject RIV: BH - Optics, Masers, Lasers Impact factor: 0.353, year: 2005

  19. Linac-augmented light sources an incremental concept for enhancing the capabilities of existing 3rd-generation storage rings.

    CERN Document Server

    Lewellen, J W

    2003-01-01

    Planned and proposed 4th-generation x-ray sources, such as energy-recovery linacs (ERLs) and single-pass x-ray free-electron lasers (X-FELs) offer a number of potential advantages, including small source size, higher peak brightness, ultrashort pulses, and potentially temporally and transversely coherent pulses. While offering unique capabilities, such facilities will also offer several important limitations, including limited numbers of user beamlines (for FELs) and a pulse-repetition rate that may be too high for many dynamics experiments (ERLs). In addition, there are many technical challenges associated with both types of facilities. A third type of facility, exemplified by the Short Pulse Photon Source (SPPS) at SLAC [1], would support neither a large number of users simultaneously nor generate coherent pulses, but would generate very intense, short x-ray pulses. Such a facility could serve as the starting point for either an ERL or an X-FEL, or a combined, hybrid machine. For the foreseeable future, how...

  20. On the origin of nonclassical light generation upon resonant excitation of a GaAs semiconductor microcavity

    Science.gov (United States)

    Demenev, A. A.; Domaretskii, D. R.; Parakhonskii, A. L.; Lebedev, M. V.

    2017-10-01

    It was shown in JETP Lett. 102, 508 (2015) that the intensity correlation function of the emission from a high-quality-factor semiconductor microcavity under resonant optical pumping exhibits an oscillatory behavior with an unexpectedly long oscillation period and a long decay time, which fall in the nanosecond range. A further investigation demonstrates that the origin of these oscillations is not related to the weak Rabi interaction between long-lived localized exciton states in the quantum well and the electromagnetic field of the microcavity mode. It proves that the semiconductor microcavity plays a secondary role in the observation of nonclassical light: it provides the spectral selection of the modes of the pump laser. We believe that intrinsic instabilities lead to the chaotic excitation of spiking in the laser modes under a constant operating current.

  1. Efficient second harmonic generation of double-end diffusion-bonded Nd:YVO4 self-Raman laser producing 7.9 W yellow light.

    Science.gov (United States)

    Zhu, Haiyong; Duan, Yanmin; Zhang, Ge; Huang, Chenghui; Wei, Yong; Shen, Hongyuan; Zheng, Yiqun; Huang, Lingxiong; Chen, Zhenqiang

    2009-11-23

    A high power and efficient 588 nm yellow light is demonstrated through intracavity frequency doubling of an acousto-optic Q-switched self-frequency Raman laser. A 30-mm-length double-end diffusion-bonded Nd:YVO(4) crystal was utilized for efficient self-Raman laser operation by reducing the thermal effects and increasing the interaction length for the stimulated Raman scattering. A 15-mm-length LBO with non-critical phase matching (theta = 90 degrees, phi = 0 degrees) cut was adopted for efficient second-harmonic generation. The focus position of incident pump light and both the repetition rate and the duty cycle of the Q-switch have been optimized. At a repetition rate of 110 kHz and a duty cycle of 5%, the average power of 588 nm light is up to 7.93 W while the incident pump power is 26.5 W, corresponding to an overall diode-yellow conversion efficiency of 30% and a slope efficiency of 43%.

  2. The influence of bubble populations generated under windy conditions on the blue-green light transmission in the upper ocean: An exploratory approach

    Science.gov (United States)

    Wang, Chengan; Tan, Jianyu; Lai, Qingzhi

    2016-12-01

    The “blue-green window” in the ocean plays an important role in functions such as communication between vessels, underwater target identification, and remote sensing. In this study, the transmission process of blue-green light in the upper ocean is analyzed numerically using the Monte Carlo method. First, the effect of total number of photons on the numerical results is evaluated, and the most favorable number is chosen to ensure accuracy without excessive costs for calculation. Then, the physical and mathematical models are constructed. The rough sea surface is generated under windy conditions and the transmission signals are measured in the far field. Therefore, it can be conceptualized as a 1D slab with a rough boundary surface. Under windy conditions, these bubbles form layers that are horizontally homogeneous and decay exponentially with depth under the influence of gravity. The effects of bubble populations on the process of blue-green light transmission at different wind speeds, wavelengths, angle of incidence and chlorophyll-a concentrations are studied for both air-incident and water-incident cases. The results of this study indicate that the transmission process of blue-green light is significantly influenced by bubbles under high wind-speed conditions.

  3. White light generation in Dy{sup 3+}-and Ce{sup 3+}/Dy{sup 3+}-doped zinc–sodium–aluminosilicate glasses

    Energy Technology Data Exchange (ETDEWEB)

    Caldiño, U., E-mail: cald@xanum.uam.mx [Departamento de Física, Universidad Autónoma Metropolitana-Iztapalapa, P.O. Box 55-534, 09340 México, D.F. (Mexico); Lira, A. [Departamento de Física , Facultad de Ciencias, Universidad Autónoma del estado de México, C.P. 50000 Toluca (Mexico); Meza-Rocha, A.N. [Departamento de Física, Universidad Autónoma Metropolitana-Iztapalapa, P.O. Box 55-534, 09340 México, D.F. (Mexico); Pasquini, E. [Istituto di Fisica Applicata Nello Carrara, C.N.R., Via Madonna del Piano 10, Sesto Fiorentino, 50019 Firenze (Italy); Dipartimento di Fisica e Astronomia, Università di Firenze, Via Sansone 1, Sesto Fiorentino, 50019 Firenze (Italy); Pelli, S. [Istituto di Fisica Applicata Nello Carrara, C.N.R., Via Madonna del Piano 10, Sesto Fiorentino, 50019 Firenze (Italy); Speghini, A. [Istituto di Fisica Applicata Nello Carrara, C.N.R., Via Madonna del Piano 10, Sesto Fiorentino, 50019 Firenze (Italy); Dipartimento di Biotecnologie, Università di Verona, and INSTM, UdR Verona, Strada Le Grazie 15, I-37314 Verona (Italy); Bettinelli, M. [Dipartimento di Biotecnologie, Università di Verona, and INSTM, UdR Verona, Strada Le Grazie 15, I-37314 Verona (Italy); Righini, G.C. [Istituto di Fisica Applicata Nello Carrara, C.N.R., Via Madonna del Piano 10, Sesto Fiorentino, 50019 Firenze (Italy); Museo Storico della Fisica e Centro Studi e Ricerche “Enrico Fermi”, Piazza del Viminale 2, 00184 Roma (Italy)

    2015-11-15

    A spectroscopic investigation of 1% Dy{sub 2}O{sub 3}-singly doped and 0.5% Ce{sub 2}O{sub 3}-1.0% Dy{sub 2}O{sub 3}-codoped zinc–sodium–aluminosilicate glasses was performed by analyzing their absorption and photoluminescence spectra, and decay times. Warm white yellow light emission, with (0.419, 0.440) CIE1931 chromaticity coordinates and 3579 K color temperature, is obtained in the Dy{sup 3+}-singly doped glass excited at 399 nm, which fits to the requirements of GaN LEDs. A quantum efficiency of 74% and a very high optical gain (38.7×10{sup −25} cm{sup 2} s) were estimated for the dysprosium {sup 4}F{sub 9/2} level luminescence, which might also make the Dy{sup 3+}-doped glass a promising gain medium for solid state yellow laser pumped by GaN LEDs. In the Ce{sup 3+}/Dy{sup 3+}-codoped glass a radiative energy transfer from Ce{sup 3+} to Dy{sup 3+} is observed upon UV excitation (310–365 nm), with a Ce{sup 3+} to Dy{sup 3+} interaction distance that could be greater than 6–12 Å. The emission color from the codoped glass can be tuned with the excitation wavelength from blue light (0.247, 0.245), upon 310 nm excitation, to cold white light (0.284, 0.300), with a 9052 K color temperature, upon 365 nm excitation. - Highlights: • Zinc–sodium–aluminosilicate (ZN) glasses are optically activated with Dy{sup 3+} (ZNDy). • ZN glasses are optically activated with Ce{sup 3+}/Dy{sup 3+} (ZNCeDy). • Dy{sup 3+} is sensitized by Ce{sup 3+} through a radiative energy transfer. • ZNDy glass can generate 3579 K warm white yellow light emission. • ZNCeDy glass can generate 9052 K cold white light emission.

  4. Properties of photocatalytically generated oxygen species produced by Ag2Se-graphene oxide heterojunction and its application for the visible-light degradation of ammonia

    Science.gov (United States)

    Meng, Ze-Da; Zhao, Wei; Kim, Sukyoung

    2017-11-01

    Reactive oxygen species (ROS) can be produced by the interactions between sunlight and light-absorbing substances in aqueous environments, and these ROS are capable of destroying various organic pollutants in wastewater. In this study, the photocatalytic degradation of ammonia in petrochemical wastewater was investigated by solar light photocatalysis. We used graphene oxide modified Ag2Se nanoparticles to enhance the activity of photochemically generated oxygen (PGO) species. There was a catastrophic decrease in the surface area and pore volume of the Ag2Se-graphene oxide (Ag2Se-G) samples because of the deposition of Ag2Se. The generation of ROS was detected by the oxidation of 1,5- diphenyl carbazide (DPCI) to 1,5-diphenyl carbazone (DPCO). It was revealed that the photocurrent density and PGO effect increased with the graphene oxide modified. The experimental results indicate that this heterogeneous catalyst achieved a degradation of 88.43% under visiblelight irradiation. The NH3 degradation product was N2 and neither NO2- nor NO3- were detected.[Figure not available: see fulltext.

  5. Enhanced Emission by Accumulated Charges at Organic/Metal Interfaces Generated during the Reverse Bias of Organic Light Emitting Diodes

    Directory of Open Access Journals (Sweden)

    Soichiro Nozoe

    2017-10-01

    Full Text Available A high frequency rectangular alternating voltage was applied to organic light emitting diodes (OLEDs with the structure ITO/TPD/Alq3/Al and ITO/CoPc/Alq3/Al, where ITO is indium-tin-oxide, TPD is 4,4′-bis[N-phenyl-N-(m-tolylamino]biphenyl, CoPc is cobalt phthalocyanine, and Alq3 is Tris(8-quinolinolatoaluminum, and the effect on emission of the reverse bias was examined. The results reveal that the emission intensity under an alternating reverse-forward bias is greater than that under an alternating zero-forward bias. The difference in the emission intensity (∆I increased both for decreasing frequency and increasing voltage level of the reverse bias. In particular, the change in emission intensity was proportional to the voltage level of the reverse bias given the same frequency. To understand ΔI, this paper proposes a model in which an OLED works as a capacitor under reverse bias, where positive and negative charges accumulate on the metal/organic interfaces. In this model, the emission enhancement that occurs during the alternating reverse-forward bias is rationalized as a result of the charge accumulation at the organic/metal interfaces during the reverse bias, which possibly modulates the vacuum level shifts at the organic/metal interfaces to reduce both the hole injection barrier at the organic/ITO interface and the electron injection barrier at the organic/Al interface under forward bias.

  6. Breaking the Carnot limit without violating the second law: A thermodynamic analysis of off-resonant quantum light generation

    Science.gov (United States)

    Boukobza, E.; Ritsch, H.

    2013-06-01

    The Carnot limit, formulated in 1824, represents the maximal efficiency of a classical heat engine. In this work we present a thermodynamical analysis of a light amplifier based on a three-level atom coupled off-resonantly to a single quantized cavity mode and to two heat reservoirs with positive temperatures. Based on standard work and heat flow equilibrium, we show that for a cavity blue-detuned with respect to the atomic resonance, the system can surpass the Carnot limit. Nevertheless, the second law of thermodynamics is still obeyed, as the total entropy always increases. By analyzing a semiclassical version of the model, we derive a formula for the critical frequency for which the Carnot limit is broken and a formula for the amplifier efficiency which agrees with its quantum counterpart. In the semiclassical regime, however, the second law is not satisfied and hence it does not offer a physically acceptable description of the system. Finally, we show that breaking the Carnot limit occurs also in a blue-detuned quantum amplifier with output coupling, which represents a realistic model of a laser or maser.

  7. Spontaneous Intracranial Hypotension

    International Nuclear Information System (INIS)

    Joash, Dr.

    2015-01-01

    Epidemiology is not only rare but an important cause of new daily persistent headaches among young & middle age individuals. The Etiology & Pathogenesis is generally caused by spinal CSF leak. Precise cause remains largely unknown, underlying structural weakness of spinal meninges is suspected. There are several MR Signs of Intracranial Hypotension that include:- diffuse pachymeningeal (dural) enhancement; bilateral subdural, effusion/hematomas; Downward displacement of brain; enlargement of pituitary gland; Engorgement of dural venous sinuses; prominence of spinal epidural venous plexus and Venous sinus thrombosis & isolated cortical vein thrombosis. The sum of volumes of intracranial blood, CSF & cerebral tissue must remain constant in an intact cranium. Treatment in Many cases can be resolved spontaneously or by use Conservative approach that include bed rest, oral hydration, caffeine intake and use of abdominal binder. Imaging Modalities for Detection of CSF leakage include CT myelography, Radioisotope cisternography, MR myelography, MR imaging and Intrathecal Gd-enhanced MR

  8. Spontaneous wave packet reduction

    International Nuclear Information System (INIS)

    Ghirardi, G.C.

    1994-06-01

    There are taken into account the main conceptual difficulties met by standard quantum mechanics in dealing with physical processes involving macroscopic system. It is stressed how J.A.Wheeler's remarks and lucid analysis have been relevant to pinpoint and to bring to its extreme consequences the puzzling aspects of quantum phenomena. It is shown how the recently proposed models of spontaneous dynamical reduction represent a consistent way to overcome the conceptual difficulties of the standard theory. Obviously, many nontrivial problems remain open, the first and more relevant one being that of generalizing the model theories considered to the relativistic case. This is the challenge of the dynamical reduction program. 43 refs, 2 figs

  9. Microbial fuel cell assisted band gap narrowed TiO2for visible light-induced photocatalytic activities and power generation.

    Science.gov (United States)

    Khan, Mohammad Ehtisham; Khan, Mohammad Mansoob; Min, Bong-Ki; Cho, Moo Hwan

    2018-01-29

    This paper reports a simple, biogenic and green approach to obtain narrow band gap and visible light-active TiO 2 nanoparticles. Commercial white TiO 2 (w-TiO 2 ) was treated in the cathode chamber of a Microbial Fuel Cell (MFC), which produced modified light gray TiO 2 (g-TiO 2 ) nanoparticles. The DRS, PL, XRD, EPR, HR-TEM, and XPS were performed to understand the band gap decline of g-TiO 2 . The optical study revealed a significant decrease in the band gap of the g-TiO 2 (E g  = 2.80 eV) compared to the w-TiO 2 (E g  = 3.10 eV). The XPS revealed variations in the surface states, composition, Ti 4+ to Ti 3+ ratio, and oxygen vacancies in the g-TiO 2 . The Ti 3+ and oxygen vacancy-induced enhanced visible light photocatalytic activity of g-TiO 2 was confirmed by degrading different model dyes. The enhanced photoelectrochemical response under visible light irradiation further supported the improved performance of the g-TiO 2 owing to a decrease in the electron transfer resistance and an increase in charge transfer rate. During the TiO 2 treatment process, electricity generation in MFC was also observed, which was ~0.3979 V corresponding to a power density of 70.39 mW/m 2 . This study confirms narrow band gap TiO 2 can be easily obtained and used effectively as photocatalysts and photoelectrode material.

  10. Investigating the effect and uncertainties of light absorbing impurities in snow and ice on snow melt and discharge generation using a hydrologic catchment model and satellite data

    Science.gov (United States)

    Matt, Felix; Burkhart, John F.

    2017-04-01

    Light absorbing impurities in snow and ice (LAISI) originating from atmospheric deposition enhance snow melt by increasing the absorption of short wave radiation. The consequences are a shortening of the snow cover duration due to increased snow melt and, with respect to hydrologic processes, a temporal shift in the discharge generation. However, the magnitude of these effects as simulated in numerical models have large uncertainties, originating mainly from uncertainties in the wet and dry deposition of light absorbing aerosols, limitations in the model representation of the snowpack, and the lack of observable variables required to estimate model parameters and evaluate the simulated variables connected with the representation of LAISI. This leads to high uncertainties in the additional energy absorbed by the snow due to the presence of LAISI, a key variable in understanding snowpack energy-balance dynamics. In this study, we assess the effect of LAISI on snow melt and discharge generation and the involved uncertainties in a high mountain catchment located in the western Himalayas by using a distributed hydrological catchment model with focus on the representation of the seasonal snow pack. The snow albedo is hereby calculated from a radiative transfer model for snow, taking the increased absorption of short wave radiation by LAISI into account. Meteorological forcing data is generated from an assimilation of observations and high resolution WRF simulations, and LAISI mixing ratios from deposition rates of Black Carbon simulated with the FLEXPART model. To asses the quality of our simulations and the related uncertainties, we compare the simulated additional energy absorbed by the snow due to the presence of LAISI to the MODIS Dust Radiative Forcing in Snow (MODDRFS) algorithm satellite product.

  11. Singlet molecular oxygen generation by light-activated DHN-melanin of the fungal pathogen Mycosphaerella fijiensis in black Sigatoka disease of bananas.

    Directory of Open Access Journals (Sweden)

    Miguel J Beltrán-García

    Full Text Available In pathogenic fungi, melanin contributes to virulence, allowing tissue invasion and inactivation of the plant defence system, but has never been implicated as a factor for host cell death, or as a light-activated phytotoxin. Our research shows that melanin synthesized by the fungal banana pathogen Mycosphaerella fijiensis acts as a virulence factor through the photogeneration of singlet molecular oxygen O2 (1Δg. Using analytical tools, including elemental analysis, ultraviolet/infrared absorption spectrophometry and MALDI-TOF mass spectrometry analysis, we characterized both pigment content in mycelia and secreted to the culture media as 1,8-dihydroxynaphthalene (DHN-melanin type compound. This is sole melanin-type in M. fijiensis. Isolated melanins irradiated with a Nd:YAG laser at 532 nm produced monomol light emission at 1270 nm, confirming generation of O2 (1Δg, a highly reactive oxygen specie (ROS that causes cellular death by reacting with all cellular macromolecules. Intermediary polyketides accumulated in culture media by using tricyclazole and pyroquilon (two inhibitors of DHN-melanin synthesis were identified by ESI-HPLC-MS/MS. Additionally, irradiation at 532 nm of that mixture of compounds and whole melanized mycelium also generated O2 (1Δg. A pigmented-strain generated more O2 (1Δg than a strain with low melanin content. Banana leaves of cultivar Cavendish, naturally infected with different stages of black Sigatoka disease, were collected from field. Direct staining of the naturally infected leaf tissues showed the presence of melanin that was positively correlated to the disease stage. We also found hydrogen peroxide (H2O2 but we cannot distinguish the source. Our results suggest that O2 (1Δg photogenerated by DHN-melanin may be involved in the destructive effects of Mycosphaerella fijiensis on banana leaf tissues. Further studies are needed to fully evaluate contributions of melanin-mediated ROS to microbial pathogenesis.

  12. Singlet molecular oxygen generation by light-activated DHN-melanin of the fungal pathogen Mycosphaerella fijiensis in black Sigatoka disease of bananas.

    Science.gov (United States)

    Beltrán-García, Miguel J; Prado, Fernanda M; Oliveira, Marilene S; Ortiz-Mendoza, David; Scalfo, Alexsandra C; Pessoa, Adalberto; Medeiros, Marisa H G; White, James F; Di Mascio, Paolo

    2014-01-01

    In pathogenic fungi, melanin contributes to virulence, allowing tissue invasion and inactivation of the plant defence system, but has never been implicated as a factor for host cell death, or as a light-activated phytotoxin. Our research shows that melanin synthesized by the fungal banana pathogen Mycosphaerella fijiensis acts as a virulence factor through the photogeneration of singlet molecular oxygen O2 (1Δg). Using analytical tools, including elemental analysis, ultraviolet/infrared absorption spectrophometry and MALDI-TOF mass spectrometry analysis, we characterized both pigment content in mycelia and secreted to the culture media as 1,8-dihydroxynaphthalene (DHN)-melanin type compound. This is sole melanin-type in M. fijiensis. Isolated melanins irradiated with a Nd:YAG laser at 532 nm produced monomol light emission at 1270 nm, confirming generation of O2 (1Δg), a highly reactive oxygen specie (ROS) that causes cellular death by reacting with all cellular macromolecules. Intermediary polyketides accumulated in culture media by using tricyclazole and pyroquilon (two inhibitors of DHN-melanin synthesis) were identified by ESI-HPLC-MS/MS. Additionally, irradiation at 532 nm of that mixture of compounds and whole melanized mycelium also generated O2 (1Δg). A pigmented-strain generated more O2 (1Δg) than a strain with low melanin content. Banana leaves of cultivar Cavendish, naturally infected with different stages of black Sigatoka disease, were collected from field. Direct staining of the naturally infected leaf tissues showed the presence of melanin that was positively correlated to the disease stage. We also found hydrogen peroxide (H2O2) but we cannot distinguish the source. Our results suggest that O2 (1Δg) photogenerated by DHN-melanin may be involved in the destructive effects of Mycosphaerella fijiensis on banana leaf tissues. Further studies are needed to fully evaluate contributions of melanin-mediated ROS to microbial pathogenesis.

  13. Assessment of noise level and noise propagation generated by light-lift helicopters in mountain natural environments.

    Science.gov (United States)

    Grigolato, Stefano; Mologni, Omar; Proto, Andrea Rosario; Zimbalatti, Giuseppe; Cavalli, Raffaele

    2018-01-20

    The use of helicopter rises discussion about environmental noise propagation especially when it operates in proximity of environmentally sensitive areas (ESAs) for an extended period because of its potential implications in wildlife behaviours. In order to support decisions on helicopter logging operation management in proximity of ESAs, this study focused on (i) analysing the noise spectrum of a light-lift helicopter during logging operations and on (ii) assessing the noise propagation in the surrounding environments. This study investigated a helicopter logging operation for wood fuel extraction in the eastern part of the Italian Alps. The potential disturbance area covered for the entire helicopter logging operation was evaluated by a specific GIS application according to hearing sensitivity of the most sensitive wildlife species in the study area (different strigiform species). The noise level at the ground appeared to be affected by the location regardless both the use of equivalent continuous sound pressures level dB(A) (LAeq) and the single-event level (SEL) noise metrics. The lowest values were recorded when the helicopter was flown over the sound meter level located under the forest canopy, while the highest was recorded when the helicopter was unhooking the loads at the landing. The GIS application highlighted the consistent of the exceeded noise area (weighted to strigiform hearing range and sensitivity) for the lower frequency bands (0.016-0.250 kHz). A more restricted exceeded noise area concerned instead the most sensitive frequency bands" for the strigiform (1-2 kHz). Graphical abstract ᅟ.

  14. Interactions of light gravitinos

    International Nuclear Information System (INIS)

    Clark, T.E.; Lee, T.; Love, S.T.; Wu, G.

    1998-01-01

    In models of spontaneously broken supersymmetry, certain light gravitino processes are governed by the coupling of their Goldstino components. The rules for constructing SUSY and gauge invariant actions involving the Goldstino couplings to matter and gauge fields are presented. The explicit operator construction is found to be at variance with some previously reported claims. A phenomenological consequence arising from light gravitino interactions in supernova is reexamined and scrutinized. copyright 1998 The American Physical Society

  15. Spontaneous compactification to homogeneous spaces

    International Nuclear Information System (INIS)

    Mourao, J.M.

    1988-01-01

    The spontaneous compactification of extra dimensions to compact homogeneous spaces is studied. The methods developed within the framework of coset space dimensional reduction scheme and the most general form of invariant metrics are used to find solutions of spontaneous compactification equations

  16. Screening for spontaneous preterm birth

    NARCIS (Netherlands)

    van Os, M.A.; van Dam, A.J.E.M.

    2015-01-01

    Preterm birth is the most important cause of perinatal morbidity and mortality worldwide. In this thesis studies on spontaneous preterm birth are presented. The main objective was to investigate the predictive capacity of mid-trimester cervical length measurement for spontaneous preterm birth in a

  17. Effects of radiant exposure values using second and third generation light curing units on the degree of conversion of a lucirin-based resin composite.

    Science.gov (United States)

    Cardoso, Kelly Antonieta Oliveira Rodrigues de Faria; Zarpellon, Driellen Christine; Madruga, Camila Ferreira Leite; Rodrigues, José Augusto; Arrais, Cesar Augusto Galvão

    2017-01-01

    Using Fourier transform infrared analysis (FTIR) in vitro, the effects of varying radiant exposure (RE) values generated by second and third generation LED LCUs on the degree of conversion (DC) and maximum rate of polymerization (Rpmax) of an experimental Lucirin TPO-based RC were evaluated. 1 mm or 2 mm thick silicon molds were positioned on a horizontal attenuated total reflectance (ATR) unit attached to an infrared spectroscope. The RC was inserted into the molds and exposed to varying REs (18, 36 and 56 J/cm2) using second (Radii Plus, SDI) and third generation LED LCUs (Bluephase G2/Ivoclar Vivadent) or a quartz tungsten based LCU (Optilux 501/SDS Kerr). FTIR spectra (n=7) were recorded for 10 min (1 spectrum/s, 16 scans/spectrum, resolution 4 cm-1) immediately after their application to the ATR. The DC was calculated using standard techniques for observing changes in aliphatic to aromatic peak ratios both prior to, and 10 min after curing, as well as during each 1 second interval. DC and Rpmax data were analyzed using 3-way ANOVA and Tukey's post-hoc test (p=0.05). No significant difference in DC or Rpmax was observed between the 1 mm or 2 mm thick specimens when RE values were delivered by Optilux 501 or when the 1 mm thick composites were exposed to light emitted by Bluephase G2, which in turn promoted a lower DC when 18 J/cm2 (13 s) were delivered to the 2 mm thick specimens. Radii Plus promoted DC and Rpmax values close to zero under most conditions, while the delivery of 56 J/cm2 (40 s) resulted in low DC values. The third generation LCU provided an optimal polymerization of Lucirin TPO-based RC under most tested conditions, whereas the second generation LED-curing unit was useless regardless of the RE.

  18. Effects of radiant exposure values using second and third generation light curing units on the degree of conversion of a lucirin-based resin composite

    Directory of Open Access Journals (Sweden)

    Kelly Antonieta Oliveira Rodrigues de Faria CARDOSO

    Full Text Available Abstract Alternative photoinitiators with different absorption wavelengths have been used in resin composites (RCs, so it is crucial to evaluate the effectiveness of light-curing units (LCUs on these products. Objective Using Fourier transform infrared analysis (FTIR in vitro, the effects of varying radiant exposure (RE values generated by second and third generation LED LCUs on the degree of conversion (DC and maximum rate of polymerization (Rpmax of an experimental Lucirin TPO-based RC were evaluated. Material and Methods 1 mm or 2 mm thick silicon molds were positioned on a horizontal attenuated total reflectance (ATR unit attached to an infrared spectroscope. The RC was inserted into the molds and exposed to varying REs (18, 36 and 56 J/cm2 using second (Radii Plus, SDI and third generation LED LCUs (Bluephase G2/Ivoclar Vivadent or a quartz tungsten based LCU (Optilux 501/SDS Kerr. FTIR spectra (n=7 were recorded for 10 min (1 spectrum/s, 16 scans/spectrum, resolution 4 cm-1 immediately after their application to the ATR. The DC was calculated using standard techniques for observing changes in aliphatic to aromatic peak ratios both prior to, and 10 min after curing, as well as during each 1 second interval. DC and Rpmax data were analyzed using 3-way ANOVA and Tukey’s post-hoc test (p=0.05. Results No significant difference in DC or Rpmax was observed between the 1 mm or 2 mm thick specimens when RE values were delivered by Optilux 501 or when the 1 mm thick composites were exposed to light emitted by Bluephase G2, which in turn promoted a lower DC when 18 J/cm2 (13 s were delivered to the 2 mm thick specimens. Radii Plus promoted DC and Rpmax values close to zero under most conditions, while the delivery of 56 J/cm2 (40 s resulted in low DC values. Conclusions The third generation LCU provided an optimal polymerization of Lucirin TPO-based RC under most tested conditions, whereas the second generation LED-curing unit was useless

  19. Spontaneous Pneumomediastinum: Hamman Syndrome

    Directory of Open Access Journals (Sweden)

    Tushank Chadha, BS

    2018-04-01

    significant fat stranding. The image also showed an intraluminal stent traversing the gastric antrum and gastric pylorus with no indication of obstruction. Circumferential mural thickening of the gastric antrum and body were consistent with the patient’s history of gastric adenocarcinoma. The shotty perigastric lymph nodes with associated fat stranding, along the greater curvature of the distal gastric body suggested local regional nodal metastases and possible peritoneal carcinomatosis. The thoracic CT scans showed extensive pneumomediastinum that tracked into the soft tissues of the neck, which given the history of vomiting also raised concern for esophageal perforation. There was still no evidence of mediastinal abscess or fat stranding. Additionally, a left subclavian vein port catheter, which terminates with tip at the cavoatrial junction of the superior vena cava can also be seen on the image. Discussion: Spontaneous Pneumomediastinum, also known as Hamman syndrome, is defined by the uncommon incidence of free air in the mediastinum due to the bursting of alveoli, as a result of extended spells of shouting, coughing, or vomiting.1,2 The condition is diagnosed when a clear cause (aerodigestive rupture, barotrauma, infection secondary to gas-forming organisms3 for pneumomediastinum cannot be clearly identified on diagnostic studies. Macklin and Macklin were the first to note the pathogenesis of the syndrome and explained that the common denominator to spontaneous pneumomediastinum was that increased alveolar pressure leads to alveolar rupture.3 Common clinical findings for spontaneous pneumomediastinum include: chest pain, dyspnea, cough, and emesis.4 The condition is not always readily recognized on initial presentation in part for its rare incidence, estimated to be approximately 1 in every 44,500 ED patients3and also because of the non-specific presenting symptoms. For this patient, there was no clear singular cause, and therefore she received care for spontaneous

  20. Photoactivation by visible light of CdTe quantum dots for inline generation of reactive oxygen species in an automated multipumping flow system.

    Science.gov (United States)

    Ribeiro, David S M; Frigerio, Christian; Santos, João L M; Prior, João A V

    2012-07-20

    Quantum dots (QD) are semiconductor nanocrystals able to generate free radical species upon exposure to an electromagnetic radiation, usually in the ultraviolet wavelength range. In this work, CdTe QD were used as highly reactive oxygen species (ROS) generators for the control of pharmaceutical formulations containing epinephrine. The developed approach was based on the chemiluminometric monitoring of the quenching effect of epinephrine on the oxidation of luminol by the produced ROS. Due to the relatively low energy band-gap of this chalcogenide a high power visible light emitting diode (LED) lamp was used as photoirradiation element and assembled in a laboratory-made photocatalytic unit. Owing to the very short lifetime of ROS and to ensure both reproducible generation and time-controlled reaction implementation and development, all reactional processes were implemented inline by using an automated multipumping micro-flow system. A linear working range for epinephrine concentration of up to 2.28×10(-6) mol L(-1) (r=0.9953; n=5) was verified. The determination rate was about 79 determinations per hour and the detection limit was about 8.69×10(-8) mol L(-1). The results obtained in the analysis of epinephrine pharmaceutical formulations by using the proposed methodology were in good agreement with those furnished by the reference procedure, with relative deviations lower than 4.80%. Copyright © 2012 Elsevier B.V. All rights reserved.

  1. Influence of the electrode wear on the EUV generation of a discharge based extreme ultraviolet light source

    Science.gov (United States)

    Vieker, Jochen; Bergmann, Klaus

    2017-08-01

    Reliability and a long maintenance interval are major requirements for the industrial use of an extreme ultraviolet (EUV) source. In this paper we present results on the influence of the electrode erosion on the EUV generation and its lifetime limiting characteristics. The geometry of the electrodes and their influence on the gas pressure distribution within the electrode system have been found to be the key variables to characterize the regime of operation. This better understanding allows for an optimization of device parameters (e.g. gas flow or pulse energy) to counteract the erosion process, in order to increase the maintenance interval and EUV output. The EUV source under investigation is based on a hollow cathode triggered pinch plasma. A new trigger concept is introduced that enables free adjustment of the gas pressure during operation, thus enabling the operation with a high conversion efficiency of up to  >0.7 %/2πsr at 13.5 nm and 2% bandwidth. The efficiency for the peak brilliance is up to ~2.6 W kW-1 mm-2sr-1 while the maximum electrical input power of the system is 15 kW.

  2. Next Generation Sequencing of Chromosome-Specific Libraries Sheds Light on Genome Evolution in Paleotetraploid Sterlet (Acipenser ruthenus).

    Science.gov (United States)

    Andreyushkova, Daria A; Makunin, Alexey I; Beklemisheva, Violetta R; Romanenko, Svetlana A; Druzhkova, Anna S; Biltueva, Larisa B; Serdyukova, Natalya A; Graphodatsky, Alexander S; Trifonov, Vladimir A

    2017-11-10

    Several whole genome duplication (WGD) events followed by rediploidization took place in the evolutionary history of vertebrates. Acipenserids represent a convenient model group for investigation of the consequences of WGD as their representatives underwent additional WGD events in different lineages resulting in ploidy level variation between species, and these processes are still ongoing. Earlier, we obtained a set of sterlet (Acipenser ruthenus) chromosome-specific libraries by microdissection and revealed that they painted two or four pairs of whole sterlet chromosomes, as well as additional chromosomal regions, depending on rediploidization status and chromosomal rearrangements after genome duplication. In this study, we employed next generation sequencing to estimate the content of libraries derived from different paralogous chromosomes of sterlet. For this purpose, we aligned the obtained reads to the spotted gar (Lepisosteus oculatus) reference genome to reveal syntenic regions between these two species having diverged 360 Mya. We also showed that the approach is effective for synteny prediction at various evolutionary distances and allows one to clearly distinguish paralogous chromosomes in polyploid genomes. We postulated that after the acipenserid-specific WGD sterlet karyotype underwent multiple interchromosomal rearrangements, but different chromosomes were involved in this process unequally.

  3. Second harmonic generation in resonant optical structures

    Energy Technology Data Exchange (ETDEWEB)

    Eichenfield, Matt; Moore, Jeremy; Friedmann, Thomas A.; Olsson, Roy H.; Wiwi, Michael; Padilla, Camille; Douglas, James Kenneth; Hattar, Khalid Mikhiel

    2018-01-09

    An optical second-harmonic generator (or spontaneous parametric down-converter) includes a microresonator formed of a nonlinear optical medium. The microresonator supports at least two modes that can be phase matched at different frequencies so that light can be converted between them: A first resonant mode having substantially radial polarization and a second resonant mode having substantially vertical polarization. The first and second modes have the same radial order. The thickness of the nonlinear medium is less than one-half the pump wavelength within the medium.

  4. Anapole nanolasers for mode-locking and ultrafast pulse generation

    KAUST Repository

    Gongora, J. S. Totero

    2017-05-31

    Nanophotonics is a rapidly developing field of research with many suggestions for a design of nanoantennas, sensors and miniature metadevices. Despite many proposals for passive nanophotonic devices, the efficient coupling of light to nanoscale optical structures remains a major challenge. In this article, we propose a nanoscale laser based on a tightly confined anapole mode. By harnessing the non-radiating nature of the anapole state, we show how to engineer nanolasers based on InGaAs nanodisks as on-chip sources with unique optical properties. Leveraging on the near-field character of anapole modes, we demonstrate a spontaneously polarized nanolaser able to couple light into waveguide channels with four orders of magnitude intensity than classical nanolasers, as well as the generation of ultrafast (of 100 fs) pulses via spontaneous mode locking of several anapoles. Anapole nanolasers offer an attractive platform for monolithically integrated, silicon photonics sources for advanced and efficient nanoscale circuitry.

  5. Light-Front Quantization of Gauge Theories

    Energy Technology Data Exchange (ETDEWEB)

    Brodsky, Stanley J.

    2003-03-25

    Light-front wavefunctions provide a frame-independent representation of hadrons in terms of their physical quark and gluon degrees of freedom. The light-front Hamiltonian formalism provides new nonperturbative methods for obtaining the QCD spectrum and eigensolutions, including resolvant methods, variational techniques, and discretized light-front quantization. A new method for quantizing gauge theories in light-cone gauge using Dirac brackets to implement constraints is presented. In the case of the electroweak theory, this method of light-front quantization leads to a unitary and renormalizable theory of massive gauge particles, automatically incorporating the Lorentz and 't Hooft conditions as well as the Goldstone boson equivalence theorem. Spontaneous symmetry breaking is represented by the appearance of zero modes of the Higgs field leaving the light-front vacuum equal to the perturbative vacuum. I also discuss an ''event amplitude generator'' for automatically computing renormalized amplitudes in perturbation theory. The importance of final-state interactions for the interpretation of diffraction, shadowing, and single-spin asymmetries in inclusive reactions such as deep inelastic lepton-hadron scattering is emphasized.

  6. Light-Front Quantization of Gauge Theories

    Energy Technology Data Exchange (ETDEWEB)

    Brodskey, Stanley

    2002-12-01

    Light-front wavefunctions provide a frame-independent representation of hadrons in terms of their physical quark and gluon degrees of freedom. The light-front Hamiltonian formalism provides new nonperturbative methods for obtaining the QCD spectrum and eigensolutions, including resolvant methods, variational techniques, and discretized light-front quantization. A new method for quantizing gauge theories in light-cone gauge using Dirac brackets to implement constraints is presented. In the case of the electroweak theory, this method of light-front quantization leads to a unitary and renormalizable theory of massive gauge particles, automatically incorporating the Lorentz and 't Hooft conditions as well as the Goldstone boson equivalence theorem. Spontaneous symmetry breaking is represented by the appearance of zero modes of the Higgs field leaving the light-front vacuum equal to the perturbative vacuum. I also discuss an ''event amplitude generator'' for automatically computing renormalized amplitudes in perturbation theory. The importance of final-state interactions for the interpretation of diffraction, shadowing, and single-spin asymmetries in inclusive reactions such as deep inelastic lepton-hadron scattering is emphasized.

  7. Potential of the FLASH FEL technology for the construction of a kW-scale light source for the next generation lithography

    Energy Technology Data Exchange (ETDEWEB)

    Schneidmiller, E.A.; Vogel, V.F.; Weise, H.; Yurkov, M.V.

    2011-08-15

    The driving engine of the Free Electron Laser in Hamburg (FLASH) is an L-band superconducting accelerator. It is designed to operate in burst mode with 800 microsecond pulse duration at a repetition rate of 10 Hz. The maximum accelerated beam current during the macropulse is 9 mA. Our analysis shows that the FLASH technology has great potential since it is possible to construct a FLASH like free electron laser operating at the wavelength of 13.5 and 6.8 nanometer with an average power up to 2.6 kW. Such a source meets the physical requirements for the light source for the next generation lithography. (orig.)

  8. Status report on light electric vehicles: Market introduction makes sense only with environmentally acceptable electric power generation; LEM-Zwischenbilanz: Markteinfuehrung nur mit umweltgerechter Stromproduktion sinnvoll

    Energy Technology Data Exchange (ETDEWEB)

    Pulfer, M. [Bundesamt fuer Energie (BFE) (Switzerland). Bereich Verkehr

    1998-06-01

    Since mid-1995, a fleet test of light electric motor cars has been running at Mendrisio. In contrast to other fleet tests, it is the users` acceptance that is being tested. This pilot and demonstration project was initiated by the BFE (Federal Office of Energy) in order to accelerate the market introduction of electric vehicles now produced by the motor car industry. From the ecological point of view, the power generation process is most important. (orig.) [Deutsch] In Mendrisio laeuft seit Mitte 1995 ein Grossversuch mit Leichtelektromobilen (LEM). Im Gegensatz zu anderen Flottentests stehen hier nicht die Fahrzeuge im Vordergrund, sondern das Kauf- und Nutzerverhalten. Damit soll dieses vom Bundesamt fuer Energie (BFE) lancierte Pilot- und Demonstrationsprogramm die Markteinfuehrung der seit kurzem von der Automobilindustrie angebotenen Elektrofahrzeuge beschleunigt werden. Aus oekologischer Sicht ist dabei entscheidend, wie der Strom in Zukunft produziert werden wird. (orig.)

  9. Degradation of blue-phosphorescent organic light-emitting devices involves exciton-induced generation of polaron pair within emitting layers.

    Science.gov (United States)

    Kim, Sinheui; Bae, Hye Jin; Park, Sangho; Kim, Wook; Kim, Joonghyuk; Kim, Jong Soo; Jung, Yongsik; Sul, Soohwan; Ihn, Soo-Ghang; Noh, Changho; Kim, Sunghan; You, Youngmin

    2018-03-23

    Degradation of organic materials is responsible for the short operation lifetimes of organic light-emitting devices, but the mechanism by which such degradation is initiated has yet to be fully established. Here we report a new mechanism for degradation of emitting layers in blue-phosphorescent devices. We investigate binary mixtures of a wide bandgap host and a series of novel Ir(III) complex dopants having N-heterocyclocarbenic ligands. Our mechanistic study reveals the charge-neutral generation of polaron pairs (radical ion pairs) by electron transfer from the dopant to host excitons. Annihilation of the radical ion pair occurs by charge recombination, with such annihilation competing with bond scission. Device lifetime correlates linearly with the rate constant for the annihilation of the radical ion pair. Our findings demonstrate the importance of controlling exciton-induced electron transfer, and provide novel strategies to design materials for long-lifetime blue electrophosphorescence devices.

  10. Spontaneous breaking of supersymmetry

    Energy Technology Data Exchange (ETDEWEB)

    Zumino, B.

    1981-12-01

    There has been recently a revival of interest in supersymmetric gauge theories, stimulated by the hope that supersymmetry might help in clarifying some of the questions which remain unanswered in the so called Grand Unified Theories and in particular the gauge hierarchy problem. In a Grand Unified Theory one has two widely different mass scales: the unification mass M approx. = 10/sup 15/GeV at which the unification group (e.g. SU(5)) breaks down to SU(3) x SU(2) x U(1) and the mass ..mu.. approx. = 100 GeV at which SU(2) x U(1) is broken down to the U(1) of electromagnetism. There is at present no theoretical understanding of the extreme smallness of the ratio ..mu../M of these two numbers. This is the gauge hierarchy problem. This lecture attempts to review the various mechanisms for spontaneous supersymmetry breaking in gauge theories. Most of the discussions are concerned with the tree approximation, but what is presently known about radiative correction is also reviewed.

  11. Spontaneous intracranial hypotension

    International Nuclear Information System (INIS)

    Haritanti, A.; Karacostas, D.; Drevelengas, A.; Kanellopoulos, V.; Paraskevopoulou, E.; Lefkopoulos, A.; Economou, I.; Dimitriadis, A.S.

    2009-01-01

    Spontaneous intracranial hypotension (SIH) is an uncommon but increasingly recognized syndrome. Orthostatic headache with typical findings on magnetic resonance imaging (MRI) are the key to diagnosis. Delayed diagnosis of this condition may subject patients to unnecessary procedures and prolong morbidity. We describe six patients with SIH and outline the important clinical and neuroimaging findings. They were all relatively young, 20-54 years old, with clearly orthostatic headache, minimal neurological signs (only abducent nerve paresis in two) and diffuse pachymeningeal gadolinium enhancement on brain MRI, while two of them presented subdural hygromas. Spinal MRI was helpful in detecting a cervical cerebrospinal fluid leak in three patients and dilatation of the vertebral venous plexus with extradural fluid collection in another. Conservative management resulted in rapid resolution of symptoms in five patients (10 days-3 weeks) and in one who developed cerebral venous sinus thrombosis, the condition resolved in 2 months. However, this rapid clinical improvement was not accompanied by an analogous regression of the brain MR findings that persisted on a longer follow-up. Along with recent literature data, our patients further point out that SIH, to be correctly diagnosed, necessitates increased alertness by the attending physician, in the evaluation of headaches

  12. Spontaneous lateral temporal encephalocele.

    Science.gov (United States)

    Tuncbilek, Gokhan; Calis, Mert; Akalan, Nejat

    2013-01-01

    A spontaneous encephalocele is one that develops either because of embryological maldevelopment or from a poorly understood postnatal process that permits brain herniation to occur. We here report a rare case of lateral temporal encephalocele extending to the infratemporal fossa under the zygomatic arch. At birth, the infant was noted to have a large cystic mass in the right side of the face. After being operated on initially in another center in the newborn period, the patient was referred to our clinic with a diagnosis of temporal encephalocele. He was 6 months old at the time of admission. Computerized tomography scan and magnetic resonance imaging studies revealed a 8 × 9 cm fluid-filled, multiloculated cystic mass at the right infratemporal fossa. No intracranial pathology or connection is seen. The patient was operated on to reduce the distortion effect of the growing mass. The histopathological examination of the sac revealed well-differentiated mature glial tissue stained with glial fibrillary acid protein. This rare clinical presentation of encephaloceles should be taken into consideration during the evaluation of the lateral facial masses in the infancy period, and possible intracranial connection should be ruled out before surgery to avoid complications.

  13. Photoactivation by visible light of CdTe quantum dots for inline generation of reactive oxygen species in an automated multipumping flow system

    Energy Technology Data Exchange (ETDEWEB)

    Ribeiro, David S.M.; Frigerio, Christian; Santos, Joao L.M. [Requimte, Department of Chemical Sciences, Laboratory of Applied Chemistry, Faculty of Pharmacy, University of Porto, Rua de Jorge Viterbo Ferreira no. 228, 4050-313 Porto (Portugal); Prior, Joao A.V., E-mail: joaoavp@ff.up.pt [Requimte, Department of Chemical Sciences, Laboratory of Applied Chemistry, Faculty of Pharmacy, University of Porto, Rua de Jorge Viterbo Ferreira no. 228, 4050-313 Porto (Portugal)

    2012-07-20

    Highlights: Black-Right-Pointing-Pointer CdTe quantum dots generate free radical species upon exposure to visible radiation. Black-Right-Pointing-Pointer A high power visible LED lamp was used as photoirradiation element. Black-Right-Pointing-Pointer The laboratory-made LED photocatalytic unit was implemented inline in a MPFS. Black-Right-Pointing-Pointer Free radical species oxidize luminol producing a strong chemiluminescence emission. Black-Right-Pointing-Pointer Epinephrine scavenges free radical species quenching chemiluminescence emission. - Abstract: Quantum dots (QD) are semiconductor nanocrystals able to generate free radical species upon exposure to an electromagnetic radiation, usually in the ultraviolet wavelength range. In this work, CdTe QD were used as highly reactive oxygen species (ROS) generators for the control of pharmaceutical formulations containing epinephrine. The developed approach was based on the chemiluminometric monitoring of the quenching effect of epinephrine on the oxidation of luminol by the produced ROS. Due to the relatively low energy band-gap of this chalcogenide a high power visible light emitting diode (LED) lamp was used as photoirradiation element and assembled in a laboratory-made photocatalytic unit. Owing to the very short lifetime of ROS and to ensure both reproducible generation and time-controlled reaction implementation and development, all reactional processes were implemented inline by using an automated multipumping micro-flow system. A linear working range for epinephrine concentration of up to 2.28 Multiplication-Sign 10{sup -6} mol L{sup -1} (r = 0.9953; n = 5) was verified. The determination rate was about 79 determinations per hour and the detection limit was about 8.69 Multiplication-Sign 10{sup -8} mol L{sup -1}. The results obtained in the analysis of epinephrine pharmaceutical formulations by using the proposed methodology were in good agreement with those furnished by the reference procedure, with

  14. Analysis of oil-biodiesel samples by high performance liquid chromatography using the normal phase column of new generation and the evaporative light scattering detector.

    Science.gov (United States)

    Fedosov, Sergey N; Fernandes, Natalia A; Firdaus, Mohd Y

    2014-01-24

    Conversion of vegetable oil to biodiesel is usually monitored by gas chromatography. This is not always convenient because of (i) an elaborate derivatization of the samples; (ii) inhibition of this process by methanol and water; (iii) low stability of the derivatives under storage. HPLC methods are apparently more convenient, but none of the described variants had won a wide recognition so far. This can be ascribed to the problems of reproducibility (in the case of normal phase chromatography) and limited separation of some analytes (in the case of reverse phase chromatography). Here we report an HPLC procedure suitable for separation of biodiesel, free fatty acids, glycerides, glycerol and lecithin. The normal phase column of new generation (Poroshell 120 HILIC) and the novel gradient were used. The method was tested on both the artificial mixtures and the crude reaction samples. Elution of the analytes was monitored by an evaporative light scattering detector. This method is usually confined to a very limited range of masses, where only a part of the complex calibration curve is used. We have analyzed the light scattering signal within a very broad range of masses, whereupon the calibration curves were produced. The data were approximated by the appropriate equations used afterward to recalculate the signal to the mass in a convenient way. An experimental conversion of rapeseed oil to biodiesel was performed by a liquid lipase formulation. This process was monitored by HPLC to illustrate advantages of the suggested registration method. Copyright © 2013 Elsevier B.V. All rights reserved.

  15. Group-theoretic condition for spontaneous CP violation

    Science.gov (United States)

    Haber, Howard E.; Surujon, Ze'ev

    2012-10-01

    We formulate the necessary conditions for a scalar potential to exhibit spontaneous CP violation. Associated with each complex scalar field is a U(1) symmetry that may be explicitly broken by terms in the scalar potential (called spurions). In order for CP-odd phases in the vacuum to be physical, these phases must be related to spontaneously broken U(1) generators that are also explicitly broken by a sufficient number of inequivalent spurions. In the case where the vacuum is characterized by a single complex phase, our result implies that the phase must be associated with a U(1) generator that is broken explicitly by at least two inequivalent spurions. A suitable generalization of this result to the case of multiple complex phases has also been obtained. These conditions may be used both to distinguish models capable of spontaneous CP violation and as a model building technique for obtaining spontaneously CP-violating deformations of CP-conserving models. As an example, we analyze the generic two Higgs doublet model, where we also carry out a complete spurion analysis. We also comment on other models with spontaneous CP violation, including the chiral Lagrangian, a minimal version of the Nelson-Barr model, and little Higgs models with spontaneous CP violation.

  16. Spontaneous T Cell Proliferation: A Physiologic Process to Create and Maintain Homeostatic Balance and Diversity of the Immune System

    Science.gov (United States)

    Min, Booki

    2018-01-01

    Naive T lymphocytes undergo heterogeneous proliferative responses when introduced into lymphopenic hosts, referred to as “homeostatic proliferation” and “spontaneous proliferation.” Spontaneous proliferation is a unique process through which the immune system generates memory phenotype cells with increasing T cell receptors repertoire complexity. Here, the mechanisms that initiate and control spontaneous proliferation are discussed. PMID:29616038

  17. Bilateral spontaneous carotid artery dissection.

    Science.gov (United States)

    Townend, Bradley Scott; Traves, Laura; Crimmins, Denis

    2005-06-01

    Bilateral internal carotid artery dissections have been reported, but spontaneous bilateral dissections are rare. Internal carotid artery dissection can present with a spectrum of symptoms ranging from headache to completed stroke. Two cases of spontaneous bilateral carotid artery dissection are presented, one with headache and minimal symptoms and the other with a stroke syndrome. No cause could be found in either case, making the dissections completely spontaneous. Bilateral internal carotid artery dissection (ICAD) should be considered in young patients with unexplained head and neck pain with or without focal neurological symptoms and signs. The increasing availability of imaging would sustain the higher index of suspicion.

  18. Simulating Supernova Light Curves

    Energy Technology Data Exchange (ETDEWEB)

    Even, Wesley Paul [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Dolence, Joshua C. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-05-05

    This report discusses supernova light simulations. A brief review of supernovae, basics of supernova light curves, simulation tools used at LANL, and supernova results are included. Further, it happens that many of the same methods used to generate simulated supernova light curves can also be used to model the emission from fireballs generated by explosions in the earth’s atmosphere.

  19. Public transit generates new physical activity: Evidence from individual GPS and accelerometer data before and after light rail construction in a neighborhood of Salt Lake City, Utah, USA.

    Science.gov (United States)

    Miller, Harvey J; Tribby, Calvin P; Brown, Barbara B; Smith, Ken R; Werner, Carol M; Wolf, Jean; Wilson, Laura; Oliveira, Marcelo G Simas

    2015-11-01

    Poor health outcomes from insufficient physical activity (PA) are a persistent public health issue. Public transit is often promoted for positive influence on PA. Although there is cross-sectional evidence that transit users have higher PA levels, this may be coincidental or shifted from activities such as recreational walking. We use a quasi-experimental design to test if light rail transit (LRT) generated new PA in a neighborhood of Salt Lake City, Utah, USA. Participants (n=536) wore Global Positioning System (GPS) receivers and accelerometers before (2012) and after (2013) LRT construction. We test within-person differences in individuals' PA time based on changes in transit usage pre- versus post-intervention. We map transit-related PA to detect spatial clustering of PA around the new transit stops. We analyze within-person differences in PA time based on daily transit use and estimate the effect of daily transit use on PA time controlling for socio-demographic variables. Results suggest that transit use directly generates new PA that is not shifted from other PA. This supports the public health benefits from new high quality public transit such as LRT. Copyright © 2015 Elsevier Ltd. All rights reserved.

  20. Visible-light-driven TiO2/Ag3PO4/GO heterostructure photocatalyst with dual-channel for photo-generated charges separation

    International Nuclear Information System (INIS)

    Lu, Bingqing; Ma, Ni; Wang, Yaping; Qiu, Yiwei; Hu, Haihua; Zhao, Jiahuan; Liang, Dayu; Xu, Sheng; Li, Xiaoyun; Zhu, Zhiyan; Cui, Can

    2015-01-01

    Highlights: • TiO 2 /Ag 3 PO 4 /GO was synthesized with a facile two-step method. • TiO 2 /Ag 3 PO 4 /GO exhibit superior photocatalytic activity and stability. • TiO 2 /Ag 3 PO 4 /GO has dual-channel for photo-generated charges separation. • TiO 2 /Ag 3 PO 4 /GO composite reduces the consumption of Ag. - Abstract: A novel triple-component TiO 2 /Ag 3 PO 4 /graphene oxide (TiO 2 /Ag 3 PO 4 /GO) photocatalyst with dual channels for photo-generated charges separation has been synthesized to improve the photocatalytic activity and stability of Ag 3 PO 4 under visible light. The synthesis involved in-situ growth of Ag 3 PO 4 nanoparticles on GO sheets to form Ag 3 PO 4 /GO, and then deposited TiO 2 nanocrystals on the surface of Ag 3 PO 4 by hydrolysis of Ti(SO 4 ) 2 at low-temperature hydrothermal condition. The TiO 2 /Ag 3 PO 4 /GO exhibited superior photocatalytic activity and stability to bare Ag 3 PO 4 , TiO 2 /Ag 3 PO 4 and Ag 3 PO 4 /GO in degradation of Rhodamine B and phenol solutions under visible light. It is suggested that the photo-generated electrons in the conduction band of Ag 3 PO 4 can be quickly transferred to GO, while the holes in the valence band of Ag 3 PO 4 can be transferred to the valence band of TiO 2 . The dual transfer channels at the interfaces of TiO 2 /Ag 3 PO 4 /GO result in effective charges separation, leading to enhanced photocatalytic activity and stability. Furthermore, the content of noble metal Ag significantly reduces from 77 wt% in bare Ag 3 PO 4 to 55 wt% in the nanocomposite. The concept of establishing dual channels for charges separation in a triple-component heterostructure provides a promising way to develop photocatalysts with high efficiency

  1. Spontaneous emergence of free-space optical and atomic patterns

    International Nuclear Information System (INIS)

    Schmittberger, Bonnie L; Gauthier, Daniel J

    2016-01-01

    The spontaneous formation of patterns in dynamical systems is a rich phenomenon that transcends scientific boundaries. Here, we report our observation of coupled optical–atomic pattern formation, which results in the creation of self-organized, multimode structures in free-space laser-driven cold atoms. We show that this process gives rise to spontaneous three-dimensional Sisyphus cooling even at very low light intensities and the emergence of self-organized structures on both sub- and super-wavelength scales. (paper)

  2. Spontaneous intraorbital hematoma: case report

    Directory of Open Access Journals (Sweden)

    Vinodan Paramanathan

    2010-12-01

    Full Text Available Vinodan Paramanathan, Ardalan ZolnourianQueen's Hospital NHS Foundation Trust, Burton on Trent, Staffordshire DE13 0RB, UKAbstract: Spontaneous intraorbital hematoma is an uncommon clinical entity seen in ophthalmology practice. It is poorly represented in the literature. Current evidence attributes it to orbital trauma, neoplasm, vascular malformations, acute sinusitis, and systemic abnormalities. A 65-year-old female presented with spontaneous intraorbital hematoma manifesting as severe ocular pains, eyelid edema, proptosis, and diplopia, without a history of trauma. Computer tomography demonstrated a fairly well defined extraconal lesion with opacification of the paranasal sinuses. The principal differential based on all findings was that of a spreading sinus infection and an extraconal tumor. An unprecedented finding of a spontaneous orbital hematoma was discovered when the patient was taken to theater. We discuss the rarity of this condition and its management.Keywords: hemorrhage, ophthalmology, spontaneous, intra-orbital, hematoma

  3. Spontaneous ischaemic stroke in dogs

    DEFF Research Database (Denmark)

    Gredal, Hanne Birgit; Skerritt, G. C.; Gideon, P.

    2013-01-01

    Translation of experimental stroke research into the clinical setting is often unsuccessful. Novel approaches are therefore desirable. As humans, pet dogs suffer from spontaneous ischaemic stroke and may hence offer new ways of studying genuine stroke injury mechanisms.......Translation of experimental stroke research into the clinical setting is often unsuccessful. Novel approaches are therefore desirable. As humans, pet dogs suffer from spontaneous ischaemic stroke and may hence offer new ways of studying genuine stroke injury mechanisms....

  4. Spontaneity and international marketing performance

    OpenAIRE

    Souchon, Anne L.; Hughes, Paul; Farrell, Andrew M.; Nemkova, Ekaterina; Oliveira, Joao S.

    2016-01-01

    The file attached to this record is the author's final peer reviewed version. The Publisher's final version can be found by following the DOI link. Purpose – The purpose of this paper is to ascertain how today’s international marketers can perform better on the global scene by harnessing spontaneity. Design/methodology/approach – The authors draw on contingency theory to develop a model of the spontaneity – international marketing performance relationship, and identify three potential m...

  5. Advanced Light Source (ALS)

    Data.gov (United States)

    Federal Laboratory Consortium — The Advanced Light Source (ALS), a world leader in soft x-ray science, generates light in the wavelengths needed for examining the atomic and electronic structure of...

  6. WOW: light print, light propel, light point

    Science.gov (United States)

    Glückstad, Jesper; Bañas, Andrew; Aabo, Thomas; Palima, Darwin

    2012-10-01

    We are presenting so-called Wave-guided Optical Waveguides (WOWs) fabricated by two-photon polymerization and capable of being optically manipulated into any arbitrary orientation. By integrating optical waveguides into the structures we have created freestanding waveguides which can be positioned 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. In a broader context, this research shows that optically trapped micro-fabricated structures can potentially help bridge the diffraction barrier. This structure-mediated paradigm may be carried forward to open new possibilities for exploiting beams from far-field optics down to the sub-wavelength domain.

  7. Effect of some operational parameters on the hydrogen generation efficiency of Ni-ZnO/PANI composite under visible-light irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Nsib, Mohamed Faouzi, E-mail: Mohamed.faouzi.ncib@gmail.com [URCMEP (UR11ES85), Faculty of Sciences, University of Gabès, 6029 Gabès (Tunisia); National School of Engineers (ENIG), University of Gabès, 6029 Gabès (Tunisia); Naffati, Naima [URCMEP (UR11ES85), Faculty of Sciences, University of Gabès, 6029 Gabès (Tunisia); Rayes, Ali; Moussa, Noomen [URCMEP (UR11ES85), Faculty of Sciences, University of Gabès, 6029 Gabès (Tunisia); National School of Engineers (ENIG), University of Gabès, 6029 Gabès (Tunisia); Houas, Ammar [URCMEP (UR11ES85), Faculty of Sciences, University of Gabès, 6029 Gabès (Tunisia); Al Imam Mohammad Ibn Saud Islamic University (IMSIU), College of Sciences, Department of Chemistry, Riyadh 11623 (Saudi Arabia)

    2015-10-15

    Graphical abstract: UV–vis spectra of PANI, ZnO, Ni{sub 0.01}Zn{sub 0.99}O, Ni{sub 0.01}Zn{sub 0.99}O/PANI3 and Ni{sub 0.1}Zn{sub 0.9}O/PANI{sub 10} nanocomposites. - Highlights: • Ni{sub x}Zn{sub 1−x}O/PANI{sub y} photocatalysts are synthesized by the impregnation method. • Ni{sup 2+} amount control the morphology of ZnO and enhances its photoactivity. • Both Ni{sup 2+} and PANI extend the light absorption of ZnO toward the visible region. • Both Ni{sup 2+} and PANI enhance the electron–hole separation. - Abstract: Ni{sub x}Zn{sub 1−x}O/Polyaniline hybrid photocatalysts are synthesized and used for the experiments of hydrogen production from water-splitting under visible irradiation. XRD, UV–vis DRS and SEM are used to characterize the prepared materials. It is shown that the Ni{sup 2+} amount doped into ZnO controls its morphology and enhances its photoactivity for H{sub 2} generation. Polyaniline (PANI) is shown to sensitize ZnO and to extend its light absorption toward the visible region. The hybrid photocatalyst with 10 mol% Ni{sup 2+} and 10 wt.% PANI shows the maximum photocatalytic H{sub 2} production for one hour of visible irradiation: ∼558 μmol while only ∼178 μmol in the presence of pure ZnO. Additives like sacrificial electron donors and carbonate salts are found to play a key role in the improvement of H{sub 2} evolution. Thus, the hydrogen photoproduction efficiency increases in the order: thiosulfate > sulfide > propanol and HCO{sub 3}{sup −} > CO{sub 3}{sup 2−}.

  8. Efficient trigger signal generation from wasted backward amplified stimulated emission at optical amplifiers for optical coherence tomography

    Directory of Open Access Journals (Sweden)

    Kim Seung Taek

    2015-01-01

    Full Text Available This paper propose an optical structure to generate trigger signals for optical coherence tomography (OCT using backward light which is usually disposed. The backward light is called backward amplified stimulated emission generated from semiconductor optical amplifier (SOA when using swept wavelength tunable laser (SWTL. A circulator is applied to block undesirable lights in the SWTL instead of an isolator in common SWTL. The circulator also diverts backward amplified spontaneous lights, which finally bring out trigger signals for a high speed digitizer. The spectra of the forward lights at SOA and the waveform of the backward lights were measured to check the procedure of the trigger formation in the experiment. The results showed that the trigger signals from the proposed SWTL with the circulator was quite usable in OCT.

  9. Heat radiation approach for harnessing heat of the cook stove to generate electricity for lighting system and charging of mobile phone

    Science.gov (United States)

    Muñoz, Rodrigo C., Jr.; Manansala, Chad Deo G.

    2018-01-01

    This study is based on the potential of thermoelectric coupling such as the thermoelectric cooler module. A thermoelectric cooler converts the heat coming from the cook stove into electricity and store in a battery. A dc-dc boost converter will be used to produce enough voltage to light a minimum house dwelling or charge phone battery. This device will be helpful to those that faces a problem on electricity especially in the isolated areas. The study aims (1) to harness heat from the cook stove up to 110 °C (2) To automatically cool-off the system to protect the thermoelectric cooler from damage due to excessive heat using an electronic solenoid; (3) To store energy harnessed in the battery; (4) To amplify the output voltages of the battery using DC to DC boost converter for lighting system and charging of mobile phone battery. From various tests conducted, it can fully charge a mobile phone in 3 hours observing the unit’s battery voltage drop from 4.06V to 3.98V. In the testing it used different orientation of steel rod by conduction to transfer heat and by radiation through tubular steel with its different dimensions. Most recent testing proved that the 2x2x9 tubular steel by radiation had the best result. The temperature reached more than a hundred degree Celsius that met the objective. The test resulted of boosting the voltage of the battery output from 3.7V to 4.96V on the average. The boosted voltage decrease as the system’s cool-off mechanism operated when the temperature reached above 110 degree Celsius decreasing output voltage to 0.8V resulting the boosted voltage to drop to zero. Therefore, the proponents concluded that heat waste can be converted to electrical energy by harnessing heat through radiation, with the help of TEC that generates voltage for lighting and can be boosted to be used for mobile charging. Furthermore, the study proved that the excess heat can damaged the TEC which was prevented by using of cooling-off mechanism, making it more

  10. Planning for spontaneous evacuation during a radiological emergency

    International Nuclear Information System (INIS)

    Johnson, J.H. Jr.

    1984-01-01

    The Federal Emergency Management Agency's (FEMA's) radiological emergency preparedness program ignores the potential problem of spontaneous evacuation during a nuclear reactor accident. To show the importance of incorporating the emergency spatial behaviors of the population at risk in radiological emergency preparedness and response plans, this article presents empirical evidence that demonstrates the potential magnitude and geographic extent of spontaneous evacuation in the event of an accident at the Long Island Lighting Company's Shoreham Nuclear Power Station. The results indicate that, on the average, 39% of the population of Long Island is likely to evacuate spontaneously and thus to cast an evacuation shadow extending at least 25 miles beyond the plant. On the basis of these findings, necessary revisions to FEMA's radiological emergency preparedness program are outlined

  11. General theory of spontaneous emission near exceptional points.

    Science.gov (United States)

    Pick, Adi; Zhen, Bo; Miller, Owen D; Hsu, Chia W; Hernandez, Felipe; Rodriguez, Alejandro W; Soljačić, Marin; Johnson, Steven G

    2017-05-29

    We present a general theory of spontaneous emission at exceptional points (EPs)-exotic degeneracies in non-Hermitian systems. Our theory extends beyond spontaneous emission to any light-matter interaction described by the local density of states (e.g., absorption, thermal emission, and nonlinear frequency conversion). Whereas traditional spontaneous-emission theories imply infinite enhancement factors at EPs, we derive finite bounds on the enhancement, proving maximum enhancement of 4 in passive systems with second-order EPs and significantly larger enhancements (exceeding 400×) in gain-aided and higher-order EP systems. In contrast to non-degenerate resonances, which are typically associated with Lorentzian emission curves in systems with low losses, EPs are associated with non-Lorentzian lineshapes, leading to enhancements that scale nonlinearly with the resonance quality factor. Our theory can be applied to dispersive media, with proper normalization of the resonant modes.

  12. Synchrotron light

    International Nuclear Information System (INIS)

    2001-01-01

    'Synchrotron Light' is an interactive and detailed introduction to the physics and technology of the generation of coherent radiation from accelerators as well as to its widespread high-tech applications in science, medicine and engineering. The topics covered are the interaction of light and matter, the technology of synchrotron light sources, spectroscopy, imaging, scattering and diffraction of X-rays, and applications to materials science, biology, biochemistry, medicine, chemistry, food and pharmaceutical technology. All synchrotron light facilities are introduced with their home-page addresses. 'Synchrotron Light' provides an instructive and comprehensive multimedia learning tool for students, experienced practitioners and novices wishing to apply synchrotron radiation in their future work. Its multiple-entry points permit an easy exploration of the CD-Rom according to the users knowledge and interest. 2-D and 3-D animations and virtual reconstruction with computer-generated images guide visitors into the scientific and technical world of a synchrotron and into the applications of synchrotron radiation. This bilingual (English and French) CD-Rom can be used for self-teaching and in courses at various levels in physics, chemistry, engineering, and biology. (author)

  13. Quantum random number generator

    Science.gov (United States)

    Pooser, Raphael C.

    2016-05-10

    A quantum random number generator (QRNG) and a photon generator for a QRNG are provided. The photon generator may be operated in a spontaneous mode below a lasing threshold to emit photons. Photons emitted from the photon generator may have at least one random characteristic, which may be monitored by the QRNG to generate a random number. In one embodiment, the photon generator may include a photon emitter and an amplifier coupled to the photon emitter. The amplifier may enable the photon generator to be used in the QRNG without introducing significant bias in the random number and may enable multiplexing of multiple random numbers. The amplifier may also desensitize the photon generator to fluctuations in power supplied thereto while operating in the spontaneous mode. In one embodiment, the photon emitter and amplifier may be a tapered diode amplifier.

  14. A case of spontaneous ventriculocisternostomy

    International Nuclear Information System (INIS)

    Yamane, Kanji; Yoshimoto, Hisanori; Harada, Kiyoshi; Uozumi, Tohru; Kuwabara, Satoshi.

    1983-01-01

    The authors experienced a case of spontaneous ventriculocisternostomy diagnosed by CT scan with metrizamide and Conray. Patient was 23-year-old male who had been in good health until one month before admission, when he began to have headache and tinnitus. He noticed bilateral visual acuity was decreased about one week before admission and vomiting appeared two days before admission. He was admitted to our hospital because of bilateral papilledema and remarkable hydrocephalus diagnosed by CT scan. On admission, no abnormal neurological signs except for bilateral papilledema were noted. Immediately, right ventricular drainage was performed. Pressure of the ventricle was over 300mmH 2 O and CSF was clear. PVG and PEG disclosed an another cavity behind the third ventricle, which was communicated with the third ventricle, and occlusion of aqueduct of Sylvius. Metrizamide CT scan and Conray CT scan showed a communication between this cavity and quadrigeminal and supracerebellar cisterns. On these neuroradiological findings, the diagnosis of obstructive hydrocephalus due to benign aqueduct stenosis accompanied with spontaneous ventriculocisternostomy was obtained. Spontaneous ventriculocisternostomy was noticed to produce arrest of hydrocephalus, but with our case, spontaneous regression of such symptoms did not appeared. By surgical ventriculocisternostomy (method by Torkildsen, Dandy, or Scarff), arrest of hydrocephalus was seen in about 50 to 70 per cent, which was the same results as those of spontaneous ventriculocisternostomy. It is concluded that VP shunt or VA shunt is thought to be better treatment of obstructive hydrocephalus than the various kinds of surgical ventriculocisternostomy. (J.P.N.)

  15. Optical antenna enhanced spontaneous emission.

    Science.gov (United States)

    Eggleston, Michael S; Messer, Kevin; Zhang, Liming; Yablonovitch, Eli; Wu, Ming C

    2015-02-10

    Atoms and molecules are too small to act as efficient antennas for their own emission wavelengths. By providing an external optical antenna, the balance can be shifted; spontaneous emission could become faster than stimulated emission, which is handicapped by practically achievable pump intensities. In our experiments, InGaAsP nanorods emitting at ∼ 200 THz optical frequency show a spontaneous emission intensity enhancement of 35 × corresponding to a spontaneous emission rate speedup ∼ 115 ×, for antenna gap spacing, d = 40 nm. Classical antenna theory predicts ∼ 2,500 × spontaneous emission speedup at d ∼ 10 nm, proportional to 1/d(2). Unfortunately, at d antenna efficiency drops below 50%, owing to optical spreading resistance, exacerbated by the anomalous skin effect (electron surface collisions). Quantum dipole oscillations in the emitter excited state produce an optical ac equivalent circuit current, I(o) = qω|x(o)|/d, feeding the antenna-enhanced spontaneous emission, where q|x(o)| is the dipole matrix element. Despite the quantum-mechanical origin of the drive current, antenna theory makes no reference to the Purcell effect nor to local density of states models. Moreover, plasmonic effects are minor at 200 THz, producing only a small shift of antenna resonance frequency.

  16. Constraints and Hamiltonian in light-front quantized field theory

    International Nuclear Information System (INIS)

    Srivastava, P.P.

    1993-01-01

    Self-consistent hamiltonian formulation of scalar theory on the null plane is constructed and quantized following the Dirac procedure. The theory contains also constraint equations which would give, if solved, to a nonlocal Hamiltonian. In contrast to the equal-time formulation we obtain a different description of the spontaneous symmetry breaking in the continuum and the symmetry generators are found to annihilate the light-front vacuum. Two examples are given where the procedure cannot be applied self-consistently. The corresponding theories are known to be ill-defined from the equal-time quantization. (author)

  17. Constrained gauge fields from spontaneous Lorentz violation

    DEFF Research Database (Denmark)

    Chkareuli, J. L.; Froggatt, C. D.; Jejelava, J. G.

    2008-01-01

    Spontaneous Lorentz violation realized through a nonlinear vector field constraint of the type AµAµ=M2 (M is the proposed scale for Lorentz violation) is shown to generate massless vector Goldstone bosons, gauging the starting global internal symmetries in arbitrary relativistically invariant...... theories. The gauge invariance appears in essence as a necessary condition for these bosons not to be superfluously restricted in degrees of freedom, apart from the constraint due to which the true vacuum in a theory is chosen by the Lorentz violation. In the Abelian symmetry case the only possible theory...... couplings when expressed in terms of the pure Goldstone vector modes. However, they do not lead to physical Lorentz violation due to the simultaneously generated gauge invariance. Udgivelsesdato: June 11...

  18. Spontaneous subcapsular and perirrenal hemorrhage

    International Nuclear Information System (INIS)

    Fuster, M.J.; Saez, J.; Perez-Paya, F.J.; Fernandez, F.

    1997-01-01

    To assess the role of CT in the etiologic diagnosis of spontaneous subcapsular and perirrenal hemorrhage. The CT findings are described in 13 patients presenting subcapsular and perirrenal hemorrhage. Those patients in whom the bleeding was not spontaneous were excluded. Surgical confirmation was obtained in nine cases. In 11 of the 13 cases (84.6%), involving five adenocarcinomas, five angiomyolipoma, two complicated cysts and one case of panarterities nodosa, CT disclosed the underlying pathology. In two cases (15.4%), it only revealed the extension of the hematoma, but gave no clue to its origin. CT is the technique of choice when spontaneous subcapsular and perirrenal hemorrhage is suspected since, in most cases, it reveals the underlying pathology. (Author)

  19. Light curing through glass ceramics with a second- and a third-generation LED curing unit: effect of curing mode on the degree of conversion of dual-curing resin cements.

    Science.gov (United States)

    Flury, Simon; Lussi, Adrian; Hickel, Reinhard; Ilie, Nicoleta

    2013-12-01

    The aim of this study was to measure the degree of conversion (DC) of five dual-curing resin cements after different curing modes with a second- and a third-generation light-emitting diode (LED) curing unit. Additionally, irradiance of both light curing units was measured at increasing distances and through discs of two glass ceramics for computer-aided design/manufacturing (CAD/CAM). Irradiance and spectra of the Elipar FreeLight 2 (Standard Mode (SM)) and of the VALO light curing unit (High Power Mode (HPM) and Xtra Power Mode (XPM)) were measured with a MARC radiometer. Irradiance was measured at increasing distances (control) and through discs (1.5 to 6 mm thickness) of IPS Empress CAD and IPS e.max CAD. DC of Panavia F2.0, RelyX Unicem 2 Automix, SpeedCEM, BisCem, and BeautiCem SA was measured with an attenuated total reflectance-Fourier transform infrared spectrometer when self-cured (negative control) or light cured in SM for 40 s, HPM for 32 s, or XPM for 18 s. Light curing was performed directly (positive control) or through discs of either 1.5- or 3-mm thickness of IPS Empress CAD or IPS e.max CAD. DC was analysed with Kruskal-Wallis tests followed by pairwise Wilcoxon rank sum tests (α = 0.05). Maximum irradiances were 1,545 mW/cm(2) (SM), 2,179 mW/cm(2) (HPM), and 4,156 mW/cm(2) (XPM), and all irradiances decreased by >80 % through discs of 1.5 mm, ≥95 % through 3 mm, and up to >99 % through 6 mm. Generally, self-curing resulted in the lowest DC. For some cements, direct light curing did not result in higher DC compared to when light cured through ceramic discs. For other cements, light curing through ceramic discs of 3 mm generally reduced DC. Light curing was favourable for dual-curing cements. Some cements were more susceptible to variations in curing mode than others. When light curing a given cement, the higher irradiances of the third-generation LED curing unit resulted in similar DC compared to the second-generation one, though at shorter

  20. Spontaneous isolated celiac artery dissection

    Directory of Open Access Journals (Sweden)

    Tuba Cimilli Ozturk

    2011-01-01

    Full Text Available Dyspepsia with mild, stabbing epigastric discomfort without history of trauma is a very common symptom that emergency physicians see in their daily practice. Vascular emergencies, mostly the aortic dissection and aneurysm, are always described in the differential diagnosis with persistent symptoms. Isolated celiac artery dissection occurring spontaneously is a very rare diagnosis. The involvement of branch vessels is generally observed and patients show various clinical signs and symptoms according to the involved branch vessel. Here we are presenting a case with spontaneous isolated celiac artery dissection, without any branch vessel involvement or visceral damage, detected by computed tomography scans taken on admission.

  1. Spontaneous waves in muscle fibres

    Energy Technology Data Exchange (ETDEWEB)

    Guenther, Stefan; Kruse, Karsten [Department of Theoretical Physics, Saarland University, 66041 Saarbruecken (Germany); Max Planck Institute for the Physics of Complex Systems, Noethnitzer Street 38, 01187 Dresden (Germany)

    2007-11-15

    Mechanical oscillations are important for many cellular processes, e.g. the beating of cilia and flagella or the sensation of sound by hair cells. These dynamic states originate from spontaneous oscillations of molecular motors. A particularly clear example of such oscillations has been observed in muscle fibers under non-physiological conditions. In that case, motor oscillations lead to contraction waves along the fiber. By a macroscopic analysis of muscle fiber dynamics we find that the spontaneous waves involve non-hydrodynamic modes. A simple microscopic model of sarcomere dynamics highlights mechanical aspects of the motor dynamics and fits with the experimental observations.

  2. Evaluation of mass distribution data from 252Cf spontaneous fission

    International Nuclear Information System (INIS)

    Liu Tingjin

    2003-01-01

    The mass distribution data of 252 Cf spontaneous fission were evaluated based on 7 sets of available experimental data. The measured data were corrected for the standards and γ intensity used by using the new evaluated ones. The errors were made necessary adjusting. The evaluated experimental data were fitted with spline function without any restriction and with symmetric restriction. These two sets of fit data were recommended as reference data of the mass distribution of 252 Cf spontaneous fission. The errors of the recommended data were considerably reduced comparing with the measured ones. The light and heavy peaks are not completely symmetric. Also there are fine structures on the right side of the light peak at A=109-111 and left side of the heavy peak at A=137-139. These should be paid attention and studied further. (author)

  3. Using Motion Tracking to Detect Spontaneous Movements in Infants

    DEFF Research Database (Denmark)

    Olsen, Mikkel Damgaard; Herskind, Anna; Nielsen, Jens Bo

    2015-01-01

    We study the characteristics of infants’ spontaneous movements, based on data obtained from a markerless motion tracking system. From the pose data, the set of features are generated from the raw joint-angles of the infants and different classifiers are trained and evaluated using annotated data....... Furthermore, we look at the importance of different features and outline the most significant features for detecting spontaneous movements of infants. Using these findings for further analysis of infants’ movements, this might be used to identify infants in risk of cerebral palsy....

  4. Human Papillomavirus Infection as a Possible Cause of Spontaneous Abortion and Spontaneous Preterm Delivery

    DEFF Research Database (Denmark)

    Ambühl, Lea Maria Margareta; Baandrup, Ulrik; Dybkær, Karen

    2016-01-01

    , and 10.9% (95% CI; 10.1–11.7) for umbilical cord blood. Summary estimates for HPV prevalence of spontaneous abortions and spontaneous preterm deliveries, in cervix (spontaneous abortions: 24.5%, and pretermdeliveries: 47%, resp.) and placenta (spontaneous abortions: 24.9%, and preterm deliveries: 50......%, resp.), were identified to be higher compared to normal full-term pregnancies (푃 spontaneous abortion, spontaneous preterm...

  5. Spontaneous emission by moving atoms

    International Nuclear Information System (INIS)

    Meystre, P.; Wilkens, M.

    1994-01-01

    It is well known that spontaneous emission is not an intrinsic atomic property, but rather results from the coupling of the atom to the vacuum modes of the electromagnetic field. As such, it can be modified by tailoring the electromagnetic environment into which the atom can radiate. This was already realized by Purcell, who noted that the spontaneous emission rate can be enhanced if the atom placed inside a cavity is resonant with one of the cavity is resonant with one of the cavity modes, and by Kleppner, who discussed the opposite case of inhibited spontaneous emission. It has also been recognized that spontaneous emission need not be an irreversible process. Indeed, a system consisting of a single atom coupled to a single mode of the electromagnetic field undergoes a periodic exchange of excitation between the atom and the field. This periodic exchange remains dominant as long as the strength of the coupling between the atom and a cavity mode is itself dominant. 23 refs., 6 figs

  6. Spontaneous Development of Moral Concepts

    Science.gov (United States)

    Siegal, M.

    1975-01-01

    Moral competence is more difficult to attain than scientific competence. Since language comprehension plays a central role in conceptual development, and moral language is difficult to learn, there is a common deficiency in moral conceptual development. This suggests a theory of non-spontaneous solutions to moral problems. (Author/MS)

  7. Shell theorem for spontaneous emission

    DEFF Research Database (Denmark)

    Kristensen, Philip Trøst; Mortensen, Jakob Egeberg; Lodahl, Peter

    2013-01-01

    and therefore is given exactly by the dipole approximation theory. This surprising result is a spontaneous emission counterpart to the shell theorems of classical mechanics and electrostatics and provides insights into the physics of mesoscopic emitters as well as great simplifications in practical calculations....

  8. Prediction of Spontaneous Preterm Birth

    NARCIS (Netherlands)

    Dijkstra, Karolien

    2002-01-01

    Preterm birth is a leading cause of neonatal morbidity and mortality. It is a major goal in obstetrics to lower the incidence of spontaneous preterm birth (SPB) and related neonatal morbidity and mortality. One of the principal objectives is to discover early markers that would allow us to identify

  9. EAMJ Dec. Spontaneous.indd

    African Journals Online (AJOL)

    2008-12-12

    Dec 12, 2008 ... surgical abortion at one month gestation without any complication. The second pregnancy which was a year prior resulted in a spontaneous miscarriage at two months followed by evacuation of retained products of conception with no post abortion complications. Antibiotics were taken following both.

  10. Spontaneous fission of superheavy nuclei

    Indian Academy of Sciences (India)

    the Yukawa-plus-exponential potential. The microscopic shell and pairing corrections are obtained using the Strutinsky and BCS approaches and the cranking formulae yield the inertia tensor. Finally, the WKB method is used to calculate penetrabilities and spontaneous fission half-lives. Calculations are performed for the ...

  11. Blazards variability detected by the spatial Fermi-LAT telescope. Study of 3C454.3 and development of an optimised light curves generation method

    International Nuclear Information System (INIS)

    Escande, L.

    2012-01-01

    The Fermi Gamma-ray Space Telescope was launched on 2008 June 11, carrying the Large Area Telescope (LAT), sensitive to gamma-rays in the 20 MeV - 300 GeV energy range. The data collected since then allowed to multiply by a factor of 10 the number of Active Galactic Nuclei (AGN) detected in the GeV range. Gamma-rays observed in AGNs come from energetic precesses bringing into play very high energy charged particles. These particles are confined in a magnetized plasma jet rising in a region close to the supermassive black hole in the center of the host galaxy. This jet moves away with velocities as high as 0.9999 c, forming in many cases radio lobes on kilo-parsec or even mega-parsec scales. Among the AGNs, those whose jet inclination angle to the line of sight is small are called blazars. The combination of this small inclination angle with relativistic ejection speeds led to relativistic effects: apparent superluminal motions, amplification of the luminosity and modification of the time scales. Blazars are characterized by extreme variability at all wavelengths, on time scales from a few minutes to several months. A temporal and spectral study of the most luminous of those detected by the LAT, 3C 454.3, was done so as to constrain emission models. A new method for generating adaptive-binning light curves is also suggested in this thesis. It allows to extract the maximum of information from the LAT data whatever the flux state of the source. (author)

  12. Lighting Control System (ILCS)

    African Journals Online (AJOL)

    2017-08-08

    Aug 8, 2017 ... advanced control system for reducing the energy consumption of public street lighting systems, research by [20] analyzed ... This is accomplished by generating a square wave. The duty cycle of the .... luminosity sensor is an advanced digital light sensor, which ideal for use in a wide range of light situations.

  13. Curing light burns.

    Science.gov (United States)

    Spranley, Thomas J; Winkler, Mark; Dagate, John; Oncale, David; Strother, Elizabeth

    2012-01-01

    This study sought to reveal the potential heat generated by a light-emitting diode (LED) curing light, which has generally been considered to be relatively cool. It is likely that similarly designed curing lights will produce a similar level of heat and have the potential to cause damage to soft tissue.

  14. Mesoscale Architecture Shapes Initiation and Richness of Spontaneous Network Activity.

    Science.gov (United States)

    Okujeni, Samora; Kandler, Steffen; Egert, Ulrich

    2017-04-05

    Spontaneous activity in the absence of external input, including propagating waves of activity, is a robust feature of neuronal networks in vivo and in vitro The neurophysiological and anatomical requirements for initiation and persistence of such activity, however, are poorly understood, as is their role in the function of neuronal networks. Computational network studies indicate that clustered connectivity may foster the generation, maintenance, and richness of spontaneous activity. Since this mesoscale architecture cannot be systematically modified in intact tissue, testing these predictions is impracticable in vivo Here, we investigate how the mesoscale structure shapes spontaneous activity in generic networks of rat cortical neurons in vitro In these networks, neurons spontaneously arrange into local clusters with high neurite density and form fasciculating long-range axons. We modified this structure by modulation of protein kinase C, an enzyme regulating neurite growth and cell migration. Inhibition of protein kinase C reduced neuronal aggregation and fasciculation of axons, i.e., promoted uniform architecture. Conversely, activation of protein kinase C promoted aggregation of neurons into clusters, local connectivity, and bundling of long-range axons. Supporting predictions from theory, clustered networks were more spontaneously active and generated diverse activity patterns. Neurons within clusters received stronger synaptic inputs and displayed increased membrane potential fluctuations. Intensified clustering promoted the initiation of synchronous bursting events but entailed incomplete network recruitment. Moderately clustered networks appear optimal for initiation and propagation of diverse patterns of activity. Our findings support a crucial role of the mesoscale architectures in the regulation of spontaneous activity dynamics. SIGNIFICANCE STATEMENT Computational studies predict richer and persisting spatiotemporal patterns of spontaneous activity in

  15. Intersecting circuits generate precisely patterned retinal waves.

    Science.gov (United States)

    Akrouh, Alejandro; Kerschensteiner, Daniel

    2013-07-24

    The developing retina generates spontaneous glutamatergic (stage III) waves of activity that sequentially recruit neighboring ganglion cells with opposite light responses (ON and OFF RGCs). This activity pattern is thought to help establish parallel ON and OFF pathways in downstream visual areas. The circuits that produce stage III waves and desynchronize ON and OFF RGC firing remain obscure. Using dual patch-clamp recordings, we find that ON and OFF RGCs receive sequential excitatory input from ON and OFF cone bipolar cells (CBCs), respectively. This input sequence is generated by crossover circuits, in which ON CBCs control glutamate release from OFF CBCs via diffusely stratified inhibitory amacrine cells. In addition, neighboring ON CBCs communicate directly and indirectly through lateral glutamatergic transmission and gap junctions, both of which are required for wave initiation and propagation. Thus, intersecting lateral excitatory and vertical inhibitory circuits give rise to precisely patterned stage III retinal waves. Copyright © 2013 Elsevier Inc. All rights reserved.

  16. Spontaneous Retropharyngeal Emphysema: A Case Report | Chi ...

    African Journals Online (AJOL)

    ... is a rare clinical condition in pediatric otolaryngology. The predominant symptoms are sore throat, odynophagia, dysphagia, and neck pain. Here, we report a case of spontaneous retropharyngeal emphysema. Keywords: Iatrogenic injury, retropharyngeal emphysema, spontaneous retropharyngeal emphysem, trauma ...

  17. La maladie de Grisel : Spontaneous atlantoaxial subluxation

    NARCIS (Netherlands)

    Meek, MF; Robinson, PH; Hermens, RAEC

    Objective: "La maladie de Grisel" (Grisel's syndrome) is a spontaneously occurring atlantoaxial subluxation with torticollis. We present a case of atlantoaxial subluxation occurring in a 20-year period of pharyngoplasty surgery. The occurrence of a "spontaneous" atlantoaxial subluxation after oral

  18. Signal Processing Methods for Liquid Rocket Engine Combustion Spontaneous Stability and Rough Combustion Assessments

    Science.gov (United States)

    Kenny, R. Jeremy; Casiano, Matthew; Fischbach, Sean; Hulka, James R.

    2012-01-01

    Liquid rocket engine combustion stability assessments are traditionally broken into three categories: dynamic stability, spontaneous stability, and rough combustion. This work focuses on comparing the spontaneous stability and rough combustion assessments for several liquid engine programs. The techniques used are those developed at Marshall Space Flight Center (MSFC) for the J-2X Workhorse Gas Generator program. Stability assessment data from the Integrated Powerhead Demonstrator (IPD), FASTRAC, and Common Extensible Cryogenic Engine (CECE) programs are compared against previously processed J-2X Gas Generator data. Prior metrics for spontaneous stability assessments are updated based on the compilation of all data sets.

  19. Modulation response of quantum dot nanolight-emitting-diodes exploiting purcell-enhanced spontaneous emission

    DEFF Research Database (Denmark)

    Skovgård, Troels Suhr; Gregersen, Niels; Lorke, Michael

    2011-01-01

    The modulation bandwidth for a quantum dot light-emitting device is calculated using a detailed model for the spontaneous emission including the optical and electronic density-of-states. We show that the Purcell enhancement of the spontaneous emission rate depends critically on the degree...... of inhomogeneous broadening relative to the cavity linewidth and can improve the modulation speed only within certain parameter regimes....

  20. Constrained Gauge Fields from Spontaneous Lorentz Violation

    CERN Document Server

    Chkareuli, J L; Jejelava, J G; Nielsen, H B

    2008-01-01

    Spontaneous Lorentz violation realized through a nonlinear vector field constraint of the type $A_{\\mu}^{2}=M^{2}$ ($M$ is the proposed scale for Lorentz violation) is shown to generate massless vector Goldstone bosons, gauging the starting global internal symmetries in arbitrary relativistically invariant theories. The gauge invariance appears in essence as a necessary condition for these bosons not to be superfluously restricted in degrees of freedom, apart from the constraint due to which the true vacuum in a theory is chosen by the Lorentz violation. In the Abelian symmetry case the only possible theory proves to be QED with a massless vector Goldstone boson naturally associated with the photon, while the non-Abelian symmetry case results in a conventional Yang-Mills theory. These theories, both Abelian and non-Abelian, look essentially nonlinear and contain particular Lorentz (and $CPT$) violating couplings when expressed in terms of the pure Goldstone vector modes. However, they do not lead to physical ...

  1. Systematics of spontaneous positron lines

    International Nuclear Information System (INIS)

    Mueller, U.; Reus, T. de; Reinhardt, J.; Mueller, B.; Greiner, W.

    1985-08-01

    Dynamical and spontaneous positron emission are investigated for heavy-ion collisions with long time delay using a semiclassical description. Numerical results and analytical expressions for the characteristic quantities of the resulting spontaneous positron line, i.e., its position, width, and cross section, are compared. The expected behaviour of the line position and cross section and its visibility against the spectrum of dynamically created positrons is discussed in dependence of the united charge Zsub(u) of projectile and target nucleus in a range of systems from Zsub(u)=180 up to Zsub(u)=188. The results are confronted with presently available experimental data, and possible implications on further experiments are worked out. (orig.)

  2. Spontaneous Rotational Inversion in Phycomyces

    KAUST Repository

    Goriely, Alain

    2011-03-01

    The filamentary fungus Phycomyces blakesleeanus undergoes a series of remarkable transitions during aerial growth. During what is known as the stagea IV growth phase, the fungus extends while rotating in a counterclockwise manner when viewed from above (stagea IVa) and then, while continuing to grow, spontaneously reverses to a clockwise rotation (stagea IVb). This phase lasts for 24-48Ah and is sometimes followed by yet another reversal (stageAIVc) before the overall growth ends. Here, we propose a continuum mechanical model of this entire process using nonlinear, anisotropic, elasticity and show how helical anisotropy associated with the cell wall structure can induce spontaneous rotation and, under appropriate circumstances, the observed reversal of rotational handedness. © 2011 American Physical Society.

  3. Spontaneous regression of colon cancer.

    Science.gov (United States)

    Kihara, Kyoichi; Fujita, Shin; Ohshiro, Taihei; Yamamoto, Seiichiro; Sekine, Shigeki

    2015-01-01

    A case of spontaneous regression of transverse colon cancer is reported. A 64-year-old man was diagnosed as having cancer of the transverse colon at a local hospital. Initial and second colonoscopy examinations revealed a typical cancer of the transverse colon, which was diagnosed as moderately differentiated adenocarcinoma. The patient underwent right hemicolectomy 6 weeks after the initial colonoscopy. The resected specimen showed only a scar at the tumor site, and no cancerous tissue was proven histologically. The patient is alive with no evidence of recurrence 1 year after surgery. Although an antitumor immune response is the most likely explanation, the exact nature of the phenomenon was unclear. We describe this rare case and review the literature pertaining to spontaneous regression of colorectal cancer. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  4. Management of intractable spontaneous epistaxis

    Science.gov (United States)

    Rudmik, Luke

    2012-01-01

    Background: Epistaxis is a common otolaryngology emergency and is often controlled with first-line interventions such as cautery, hemostatic agents, or anterior nasal packing. A subset of patients will continue to bleed and require more aggressive therapy. Methods: Intractable spontaneous epistaxis was traditionally managed with posterior nasal packing and prolonged hospital admission. In an effort to reduce patient morbidity and shorten hospital stay, surgical and endovascular techniques have gained popularity. A literature review was conducted. Results: Transnasal endoscopic sphenopalatine artery ligation and arterial embolization provide excellent control rates but the decision to choose one over the other can be challenging. The role of transnasal endoscopic anterior ethmoid artery ligation is unclear but may be considered in certain cases when bleeding localizes to the ethmoid region. Conclusion: This article will focus on the management of intractable spontaneous epistaxis and discuss the role of endoscopic arterial ligation and embolization as it pertains to this challenging clinical scenario. PMID:22391084

  5. New fluorophosphate glasses co-doped with Eu{sup 3+} and Tb{sup 3+} as candidates for generating tunable visible light

    Energy Technology Data Exchange (ETDEWEB)

    Queiroz, T.B. de, E-mail: thiago.branquinho-de-queiroz@uni-bayreuth.de [Physics Institute of São Carlos, University of São Paulo, 13566-590 São Carlos, SP (Brazil); Theoretical Physics IV, University of Bayreuth, 95440 Bayreuth (Germany); Botelho, M.B.S. [Physics Institute of São Carlos, University of São Paulo, 13566-590 São Carlos, SP (Brazil); University of Brasilia, 70910-900 Brasilia, DF (Brazil); Gonçalves, T.S.; Dousti, M. Reza [Physics Institute of São Carlos, University of São Paulo, 13566-590 São Carlos, SP (Brazil); Camargo, A.S.S. de, E-mail: andreasc@ifsc.usp.br [Physics Institute of São Carlos, University of São Paulo, 13566-590 São Carlos, SP (Brazil)

    2015-10-25

    A series of optically active Eu{sup 3+} and Tb{sup 3+} doped fluorophosphate glasses with compositions (BaF{sub 2}){sub 0.25}(SrF{sub 2}){sub 0.25}(AlF{sub 3}){sub 0.10}[Al(PO{sub 3}){sub 3}]{sub 0.20}(YF{sub 3}){sub 0.20-x}(EuF{sub 3} and/or TbF{sub 3}){sub x} (x = 0 to 0.04) was prepared and characterized by optical spectroscopy. While embedded in the oxyfluoride host, the cited rare earth (RE) ions exhibit improved spectroscopic properties such as longer excited state lifetimes than in oxide glasses and intense emissions in the red ({sup 5}D{sub 0} → {sup 7}F{sub 2}, Eu{sup 3+}), green and blue ({sup 5}D{sub 4} → {sup 7}F{sub 5} and {sup 5}D{sub 3},{sup 5}G{sub 6} → {sup 7}F{sub 5},{sup 7}F{sub 4}, Tb{sup 3+}) spectral regions. Based on this fact, co-doped samples can be designed with appropriate concentrations of these two ions and generate tunable and white light upon excitation with suitable wavelengths, dispensing the need for a third blue emitting RE ion. Four co-doped samples with equal amounts of EuF{sub 3} and TbF{sub 3} and total concentration of 0.3, 0.5, 1.0 and 1.5 mol% were tested. Their CIE chromaticity coordinates were calculated for various excitation wavelengths in the region from 350 to 360 nm allowing tuned emission from blue to red. The long lifetime values of the emitting levels in these co-doped samples (τ ≈ 3.1 ms for Eu{sup 3+5}D{sub 0}, and τ ≈ 4.0 ms for Tb{sup 3+5}D{sub 4}), associated with fairly high quantum yields (Q.Y. = 5–12%) of the samples indicate that these materials could be efficiently pumped by high power LEDs around 355 nm. - Highlights: • Fluorophosphate glasses doped with Eu{sup 3+} and Tb{sup 3+} and excellent optical properties. • Tunable visible emission and white emission in co-doped samples. • Rare earth bonding preference to fluoride rather than phosphate ions.

  6. The generation of 4-hydroxynonenal, an electrophilic lipid peroxidation end product, in rabbit cornea organ cultures treated with UVB light and nitrogen mustard

    Energy Technology Data Exchange (ETDEWEB)

    Zheng, Ruijin; Po, Iris; Mishin, Vladimir; Black, Adrienne T. [Pharmacology and Toxicology, Rutgers University, Piscataway, NJ (United States); Heck, Diane E. [Environmental Science, New York Medical College, Valhalla, NY (United States); Laskin, Debra L. [Pharmacology and Toxicology, Rutgers University, Piscataway, NJ (United States); Sinko, Patrick J. [Pharmaceutics, Rutgers University, Piscataway, NJ (United States); Gerecke, Donald R.; Gordon, Marion K. [Pharmacology and Toxicology, Rutgers University, Piscataway, NJ (United States); Laskin, Jeffrey D., E-mail: jlaskin@eohsi.rutgers.edu [Environmental and Occupational Medicine, UMDNJ-Robert Wood Johnson Medical School, Piscataway, NJ (United States)

    2013-10-15

    The cornea is highly sensitive to oxidative stress, a process that can lead to lipid peroxidation. Ultraviolet light B (UVB) and nitrogen mustard (mechlorethamine) are corneal toxicants known to induce oxidative stress. Using a rabbit air-lifted corneal organ culture model, the oxidative stress responses to these toxicants in the corneal epithelium was characterized. Treatment of the cornea with UVB (0.5 J/cm{sup 2}) or nitrogen mustard (100 nmol) resulted in the generation of 4-hydroxynonenal (4-HNE), a reactive lipid peroxidation end product. This was associated with increased expression of the antioxidant, heme oxygenase-1 (HO-1). In human corneal epithelial cells in culture, addition of 4-HNE or 9-nitrooleic acid, a reactive nitrolipid formed during nitrosative stress, caused a time-dependent induction of HO-1 mRNA and protein; maximal responses were evident after 10 h with 30 μM 4-HNE or 6 h with 10 μM 9-nitrooleic acid. 4-HNE and 9-nitrooleic acid were also found to activate Erk1/2, JNK and p38 MAP kinases, as well as phosphoinositide-3-kinase (PI3)/Akt. Inhibition of p38 blocked 4-HNE- and 9-nitrooleic acid-induced HO-1 expression. Inhibition of Erk1/2, and to a lesser extent, JNK and PI3K/Akt, suppressed only 4-HNE-induced HO-1, while inhibition of JNK and PI3K/Akt, but not Erk1/2, partly reduced 9-nitrooleic acid-induced HO-1. These data indicate that the actions of 4-HNE and 9-nitrooleic acid on corneal epithelial cells are distinct. The sensitivity of corneal epithelial cells to oxidative stress may be an important mechanism mediating tissue injury induced by UVB or nitrogen mustard. - Highlights: • UVB or nitrogen mustard causes rabbit corneal epithelial injury. • 4-Hydroxynonenal (4-HNE) was formed and heme oxygenase-1 (HO-1) was increased. • 4-HNE induced HO-1 mRNA and protein expression in human corneal epithelial cells. • The induction of HO-1 by 4-HNE was through MAP kinase activation.

  7. Spontaneous baryogenesis in warm inflation

    OpenAIRE

    Brandenberger, Robert H.; Yamaguchi, Masahide

    2003-01-01

    We discuss spontaneous baryogenesis in the warm inflation scenario. In contrast with standard inflation models, radiation always exists in the warm inflation scenario, and the inflaton must be directly coupled to it. Also, the transition to the post-inflationary radiation dominated phase is smooth and the entropy is not significantly increased at the end of the period of inflation. In addition, after the period of warm inflation ends, the inflaton does not oscillate coherently but slowly roll...

  8. Spontaneous Splenic Rupture in Melanoma

    Directory of Open Access Journals (Sweden)

    Hadi Mirfazaelian

    2014-01-01

    Full Text Available Spontaneous rupture of spleen due to malignant melanoma is a rare situation, with only a few case reports in the literature. This study reports a previously healthy, 30-year-old man who came with chief complaint of acute abdominal pain to emergency room. On physical examination, abdominal tenderness and guarding were detected to be coincident with hypotension. Ultrasonography revealed mild splenomegaly with moderate free fluid in abdominopelvic cavity. Considering acute abdominal pain and hemodynamic instability, he underwent splenectomy with splenic rupture as the source of bleeding. Histologic examination showed diffuse infiltration by tumor. Immunohistochemical study (positive for S100, HMB45, and vimentin and negative for CK, CD10, CK20, CK7, CD30, LCA, EMA, and chromogranin confirmed metastatic malignant melanoma. On further questioning, there was a past history of a nasal dark skin lesion which was removed two years ago with no pathologic examination. Spontaneous (nontraumatic rupture of spleen is an uncommon situation and it happens very rarely due to neoplastic metastasis. Metastasis of malignant melanoma is one of the rare causes of the spontaneous rupture of spleen.

  9. Kinetics of pulpal temperature rise during light curing of 6 bonding agents from different generations, using light emitting diode and quartz-tungsten-halogen units: An in-vitro simulation

    Science.gov (United States)

    Khaksaran, Najmeh Khatoon; Kashi, Tahereh Jafarzadeh; Rakhshan, Vahid; Zeynolabedin, Zahra Sadat; Bagheri, Hossein

    2015-01-01

    Background: Application of bonding agents (BA) into deep cavities and light curing them might increase pulpal temperature and threaten its health. The purpose of this study was to evaluate temperature rise of pulp by light curing six BA using two different light curing units (LCU), through a dent in wall of 0.5 mm. Materials and Methods: This in vitro experiment was carried out on 96 slices of the same number of human third molars (6 BAs × 2 LCUs × 8 specimens in each group). There were 6 groups of BAs: N Bond, G-Bond, OptiBond XTR, Clearfil SE, Adper Single Bond 2 and V Bond. Each group of BA (n = 16) had two subgroups of light emitting diode (LED) and quartz-tungsten-halogen light cure units (n = 8). Each of these 16 specimens were subjected to light emitting for 20 s, once without any BAs (control) and later when a BA was applied to surface of disk. Temperature rises in 140 s were evaluated. Their mean temperature change in first 20 s were calculated and analyzed using two-way repeated-measures and one-way analysis of variance (ANOVA) and Tukey (α = 0.05). Furthermore rate of temperature increase was calculated for each material and LCU. Results: Minimum and maximum temperature rises in all subgroups were 1.7 and 2.8°C, respectively. Repeated measures ANOVA showed that both of adhesive and LCU types had significant effect on temperature rise after application of adhesives. Tukey post-hoc analysis showed Clearfil SE showed significantly higher temperature rise in comparison with Adper Single bond 2 (P = 0.047) and N Bond (P = 0.038). Temperature rose in a linear fashion during first 30-40 s and after that it was non-linear. Conclusion: 20 s of light curing seems safe for pulpal health (with critical threshold of 5.5°C). However, in longer durations and especially when using LED units, the process should be broken to two sessions. PMID:25878684

  10. Generation of shock fronts in the interaction of short pulses of intense laser light in supercritical plasma; Generacion de frentes de choque en la interaccion de pulsos cortos de luz laser intensa en plasmas supercriticos

    Energy Technology Data Exchange (ETDEWEB)

    Lopez V, V.E. [ITESST, 52650 Estado de Mexico (Mexico); Ondarza R, R. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico)

    2004-07-01

    The investigation of the laser interaction with plasma has been carried out mainly in laboratories of Europe, Japan and United States during the last decades. This studies concern the propagation of intense light laser in a non homogeneous plasma, the radiation absorption and the generation of suprathermal electrons, among others. Numerical simulations made by Denavit, for radiation pulses for up of 10{sup 20} W/cm{sup 2} on solid targets, have allowed to observe the generation of ionic crash fronts with high propagation speeds. In this work it is expanded the study of this effect through algorithms of particles simulation. (Author)

  11. Hoechst 33258 dye generates DNA-protein cross-links during ultraviolet light-induced photolysis of bromodeoxyuridine in replicated and repaired DNA

    Energy Technology Data Exchange (ETDEWEB)

    Guo Xicang; Morgan, W.F.; Cleaver, J.E.

    1986-08-01

    Substitution of bromodeoxyuridine for thymidine in the DNA of mammalian cells sensitizes them to a range of wavelengths of ultraviolet light. Cells are also sensitized to photochemical reactions involving dyes such as Hoechst 33258, which is used to produce differential staining of chromatids according to their bromodeoxyuridine content. Irradiation with 313 nm light of human and hamster cells containing bromodeoxyuridine in their DNA produced single-strand breaks but no DNA-protein cross-links. Irradiation with 360 nm light in the presence of Hoechst 33258 produced extensive DNA-protein cross-linkage as well as single-strand breaks. These cross-links were observed in DNA containing bromodeoxyuridine incorporated by either semiconservative or repair replication. When the protein was removed with proteinase K, bromodeoxyuridine in repair patches after irradiation by doses of ultraviolet (254 nm) light as low as 0.26 J/m/sup 2/ could readily be detected. Hoechst 33258-mediated photolysis, therefore, provides a sensitive new technique for measuring repair replication after ultraviolet light irradiation.

  12. Electrical current nanogeneration driven by spontaneous nanofluidic oscillations.

    Science.gov (United States)

    Gimenez, R; Mercuri, M; Berli, C L A; Bellino, M G

    2018-02-15

    Exploiting natural phenomena is a central route for providing electricity to sustainably drive wearable electronics. Here we report a nano-scale water-driven energy generator that produces tiny electrical currents from spontaneous wetting-drying oscillations in mesoporous thin films. The system was fabricated with a wormlike mesoporous silica film, which was packed in between Cu and silicon contacts. The nanogenerator runs autonomously when a water droplet is laid over the film close to the Cu electrode, as water infiltration into the film under the electrode produces a direct-current. Wetting-drying cycles, which are spontaneously triggered by water evaporation, are perfectly correlated to the generated electrical current. The autonomous water displacement through the film yields a sustained energy conversion until the droplet reservoir vanishes. This novel water-driven nanogenerator opens new alternatives for versatile, mobile and cost-effective self-powering of nanosystems and nanodevices.

  13. Spatial quantum correlations in the fluorescence of traveling-wave second-harmonic generation

    International Nuclear Information System (INIS)

    Scotto, Pierre

    2003-01-01

    We investigate theoretically the spatial quantum correlations of the light produced by spontaneous emission in type-I second-harmonic generation in the traveling-wave configuration. It is first shown that spontaneous emission occurs at both fundamental and second-harmonic frequency. Considering the quantum fluctuations of the intensities collected in symmetrical parts of the far-field plane, nonclassical correlations below the shot noise are predicted not only at fundamental frequency, but also at second-harmonic frequency. The latter cannot be traced back to any twin-photon emission mechanism, but are generated by a secondary process acting on twin photons. This mechanism also creates correlations between fundamental and second-harmonic field, at a given transverse wave number, and at opposite wave numbers. The analysis of a simplified few-mode model, on a quantum level, provides a good qualitative understanding of these correlations

  14. High-efficiency electroluminescence and amplified spontaneous emission from a thermally activated delayed fluorescent near-infrared emitter

    Science.gov (United States)

    Kim, Dae-Hyeon; D'Aléo, Anthony; Chen, Xian-Kai; Sandanayaka, Atula D. S.; Yao, Dandan; Zhao, Li; Komino, Takeshi; Zaborova, Elena; Canard, Gabriel; Tsuchiya, Youichi; Choi, Eunyoung; Wu, Jeong Weon; Fages, Frédéric; Brédas, Jean-Luc; Ribierre, Jean-Charles; Adachi, Chihaya

    2018-02-01

    Near-infrared organic light-emitting diodes and semiconductor lasers could benefit a variety of applications including night-vision displays, sensors and information-secured displays. Organic dyes can generate electroluminescence efficiently at visible wavelengths, but organic light-emitting diodes are still underperforming in the near-infrared region. Here, we report thermally activated delayed fluorescent organic light-emitting diodes that operate at near-infrared wavelengths with a maximum external quantum efficiency of nearly 10% using a boron difluoride curcuminoid derivative. As well as an effective upconversion from triplet to singlet excited states due to the non-adiabatic coupling effect, this donor-acceptor-donor compound also exhibits efficient amplified spontaneous emission. By controlling the polarity of the active medium, the maximum emission wavelength of the electroluminescence spectrum can be tuned from 700 to 780 nm. This study represents an important advance in near-infrared organic light-emitting diodes and the design of alternative molecular architectures for photonic applications based on thermally activated delayed fluorescence.

  15. Spontaneous oscillations in microfluidic networks

    Science.gov (United States)

    Case, Daniel; Angilella, Jean-Regis; Motter, Adilson

    2017-11-01

    Precisely controlling flows within microfluidic systems is often difficult which typically results in systems being heavily reliant on numerous external pumps and computers. Here, I present a simple microfluidic network that exhibits flow rate switching, bistablity, and spontaneous oscillations controlled by a single pressure. That is, by solely changing the driving pressure, it is possible to switch between an oscillating and steady flow state. Such functionality does not rely on external hardware and may even serve as an on-chip memory or timing mechanism. I use an analytic model and rigorous fluid dynamics simulations to show these results.

  16. General features of spontaneous baryogenesis

    Science.gov (United States)

    Arbuzova, Elena

    2017-04-01

    The classical version of spontaneous baryogenesis is studied in details. It is shown that the relation between the time derivative of the (pseudo)goldstone field and the baryonic chemical potential essentially depends upon the representation chosen for the fermionic fields with non-zero baryonic number (quarks). The kinetic equation, used for the calculations of the cosmological baryon asymmetry, is generalized to the case of non-stationary background. The effects of the finite interval of the integration over time are also included into consideration.

  17. Spontaneous osteonecrosis of the knee

    Energy Technology Data Exchange (ETDEWEB)

    Kattapuram, Taj M. [Department of Radiology, Massachusetts General Hospital (United States); Kattapuram, Susan V. [Department of Radiology, Massachusetts General Hospital (United States)], E-mail: skattapuram@partners.org

    2008-07-15

    Spontaneous osteonecrosis of the knee presents with acute onset of severe, pain in elderly patients, usually female and usually without a history of trauma. Originally described as idiopathic osteonecrosis, the exact etiology is still debated. Evidence suggests that an acute fracture occurs as a result of chronic stress or minor trauma to a weakened subchondral bone plate. The imaging characteristics on MR reflect the age of the lesion and the symptoms. More appropriate terminology may be ' subchondral insufficiency fracture of the knee' or 'focal subchondral osteonecrosis'.

  18. Bridging generation gaps in medical education : a "light bulb moment" at the Association for Medical Education in Europe annual conference in Barcelona

    NARCIS (Netherlands)

    van Dam, Marjel; Noben, Cindy; Higgins, Mary

    2017-01-01

    Generation gaps have been described before and so have ways to deal with them. But they were mainly focused on the teachers. We would like to bridge these generation gaps, not only by creating awareness but also by learning from each other. This leads to better equipped doctors across all

  19. Ceria Supported Pt/PtO-Nanostructures: Efficient Photocatalyst for Sacrificial Donor Assisted Hydrogen Generation under Visible-NIR Light Irradiation

    Czech Academy of Sciences Publication Activity Database

    Manwar, N.R.; Chilkalwar, A.A.; Nanda, K.K.; Chaudhary, Y.S.; Šubrt, Jan; Rayalu, S.S.; Labhsetwar, N.K.

    2016-01-01

    Roč. 4, č. 4 (2016), s. 2323-2332 ISSN 2168-0485 Institutional support: RVO:61388980 Keywords : Pt/Ceria * Photocatalysis * Water splitting * Visible-NIR light Subject RIV: CA - Inorganic Chemistry Impact factor: 5.951, year: 2016

  20. Radiological evaluation of spontaneous pneumoperitoneum

    International Nuclear Information System (INIS)

    Kim, H. S.; Kim, J. D.; Rhee, H. S.

    1982-01-01

    112 cases of spontaneous penumoperitoneum, the causes of which were confirmed by clinical and surgical procedure at Presbyterian Medical Center from January, 1977 to July, 1981 were reviewed radiologically. The results were as follows: 1. Perforation of duodenal ulcer (46/112: 41.1%), stomach ulcer (22/112: 19.6%), and stomach cancer (11/112: 9.8%) were the three most common causes of spontaneous penumoperitoneum. These were 70.5% of all causes. 2. The most common site of free gas was both subdiaphragmatic areas (46: 41.1%). Others were Rt. subdiaphragmatic only (31: 27.7%), both subdiaphragmatic with subhepatic (16: 14.3%), Rt. subdiaphragmatic with subhepatic (7: 6.2%), Rt. subdiaphragmatic only (5: 4.4%), diffuse in abdomen (4: 3.6%), and subhepatic only (3: 2.7%). So 92.0% (103/112) were located in RUQ. 3. The radiological shape of free gas was classified: crescent (52: 46.4%) of small amount; half-moon (21: 18.8%) of moderate amount; large or diffuse (39: 34.8%) of large amount.4. The age between 31 and 60 occupied 69.1% (77/112), and male was predominant (5.2 times). 5. The patient's position showing free air most frequently was erect

  1. A Case of Multiple Spontaneous Keloid Scars

    Directory of Open Access Journals (Sweden)

    Abdulhadi Jfri

    2015-07-01

    Full Text Available Keloid scars result from an abnormal healing response to cutaneous injury or inflammation that extends beyond the borders of the original wound. Spontaneous keloid scars forming in the absence of any previous trauma or surgical procedure are rare. Certain syndromes have been associated with this phenomenon, and few reports have discussed the evidence of single spontaneous keloid scar, which raises the question whether they are really spontaneous. Here, we present a 27-year-old mentally retarded single female with orbital hypertelorism, broad nasal bridge, repaired cleft lip and high-arched palate who presented with progressive multiple spontaneous keloid scars in different parts of her body which were confirmed histologically by the presence of typical keloidal collagen. This report supports the fact that keloid scars can appear spontaneously and are possibly linked to a genetic factor. Furthermore, it describes a new presentation of spontaneous keloid scars in the form of multiple large lesions in different sites of the body.

  2. Spontaneity of communication in individuals with autism.

    Science.gov (United States)

    Chiang, Hsu-Min; Carter, Mark

    2008-04-01

    This article provides an examination of issues related to spontaneity of communication in children with autism. Deficits relating to spontaneity or initiation are frequently reported in individuals with autism, particularly in relation to communication and social behavior. Nevertheless, spontaneity is not necessarily clearly conceptualized or measured. Several approaches to conceptualization of communicative spontaneity are examined with a particular focus on the continuum model and how it might be practically applied. A range of possible explanations for deficits in spontaneity of communication in children with autism is subsequently explored, including external factors (highly structured teaching programs, failure to systematically instruct for spontaneity) and intrinsic characteristics (intellectual disability, stimulus overselectivity, weak central coherence). Possible implications for future research are presented.

  3. Spontaneous cryptococcal peritonitis in cirrhotic patients.

    Directory of Open Access Journals (Sweden)

    Sungkanuparph S

    2002-07-01

    Full Text Available Spontaneous bacterial peritonitis is a common complication in patients with cirrhosis and ascites. However, spontaneous peritonitis caused by Cryptococcus neoformans is uncommon. Delayed diagnosis of cryptococcal peritonitis often results in death. We describe three cases of spontaneous cryptococcal peritonitis in patients with decompensated cirrhosis. One case had associated symptomatic human immunodeficiency virus infection. Clinical awareness of this entity may lead to the early diagnosis and proper treatment.

  4. Spontaneous Intracranial Hypotension without Orthostatic Headache

    Directory of Open Access Journals (Sweden)

    Tülay Kansu

    2009-03-01

    Full Text Available We report 2 cases of spontaneous intracranial hypotension that presented with unilateral abducens nerve palsy, without orthostatic headache. While sixth nerve palsies improved without any intervention, subdural hematoma was detected with magnetic resonance imaging. We conclude that headache may be absent in spontaneous intracranial hypotension and spontaneous improvement of sixth nerve palsy can occur, even after the development of a subdural hematoma

  5. Spontaneous renal hematoma - a case report

    International Nuclear Information System (INIS)

    Obrzut, M.; Obrzut, M.; Homa, J.; Obrzut, B.

    2006-01-01

    Spontaneous pararenal hematoma is a rare pathology most frequently coexisting with renal tumours, vascular anomalies and inflammatory processes. In some cases one cannot establish its etiology. The paper describes a case of a 58-year-old man with a spontaneous pararenal hematoma and presents a diagnostic algorithm. Ultrasonography and CT play an important role in diagnostics of spontaneous pararenal haemorrhages. These methods enable a precise evaluation of size and location of hematoma and its evolution. (author)

  6. Comparative investigations of the spontaneous and stimulated emissions from nitrogen molecules in air with femtosecond laser excitation pulses

    International Nuclear Information System (INIS)

    Li, Ziting; Wang, Zhanshan; Chu, Wei; Zeng, Bin; Yao, Jinping; Li, Guihua; Xie, Hongqiang; Cheng, Ya

    2016-01-01

    We report on experimental investigations on the spontaneous and stimulated emissions from excited nitrogen molecules generated in both linearly and circularly polarized intense laser fields. The spontaneous emission is measured from the side direction of the laser-induced filament whereas the stimulated emission generated by seed amplification is measured in the forward direction of the laser propagation. The comparison between the signal intensities of the spontaneous fluorescence emission and the seed-amplified stimulated emission provides an insight into the population inversion generated in nitrogen molecules with circularly polarized femtosecond laser pulses. (paper)

  7. Ultra-compact optical auto-correlator based on slow-light enhanced third harmonic generation in a silicon photonic crystal waveguide

    OpenAIRE

    Monat, Christelle; Grillet, Christian; Collins, Matthew; Clark, Alex; Schroeder, Jochen; Xiong, Chunle; Li, Juntao; O'Faolain, Liam; Krauss, Thomas F.; Eggleton, Benjamin J.; Moss, David J.

    2014-01-01

    We acknowledge the financial support of the European Commission through the Marie Curie program (FP7, ALLOPTICS), as well as the Faculty of Science at the University of Sydney and the Australian Research Council (ARC) through the Centre of Excellence (CUDOS), Discovery project (DP110100003) and DECRA programs (DE120100226, DE120101329, DE130101148). J.L. was supported by the grant of NKBRSF (G2010CB923200), NNSFC (11204386) and GNSF (S2012040007812). The ability to use coherent light for m...

  8. Light Sources and Lighting Circuits

    Science.gov (United States)

    Honda, Hisashi; Suwa, Takumi; Yasuda, Takeo; Ohtani, Yoshihiko; Maehara, Akiyoshi; Okada, Atsunori; Komatsu, Naoki; Mannami, Tomoaki

    means of using filler gas with a higher atomic weight. Regarding fluorescent lamps, studies and developments for longer operating life and improvement in the lumen maintenance factor for the straight-type and circular-type fluorescent lamps were actively pursued. Regarding self-ballasted fluorescent lamps, the main stream of development was aimed at reducing lamp size and increasing energy conservation, and the development of new products that took advantage of these features proceeded. In regard to LED light sources, basic research and product development, including new application development, were vigorously implemented. In basic research, studies were reported, not only on efficacy improvements through optimization of the LED chips, phosphor layers, and packaging technology, but also on photometry, colorimetry, and visual psychology. In the field of application, applications were studied for general lighting sources and also for a wide range of fields, such as automotive headlights and visible light communication. Also, many academic conferences and exhibitions were held domestically and overseas, and the high level of interest suggests high expectations for this next-generation light source. Regarding HID lamps, there was much activity in research and development and in the commercialization of the ceramic metal halide lamp product, and products were commercialized with features such as higher efficiency (130 lm/W) and higher color rendering properties (R9 ≥ 90). In the high-pressure sodium lamps, there were many study reports concerning plant growth and insect pest control using its low insect-attracting characteristics. With high-pressure mercury lamps, there were many reports on reducing lamp size and increasing intensity for use as a light source for projectors.

  9. Thoughts and sensations, twin galaxies of the inner space: The propensity to mind-wander relates to spontaneous sensations arising on the hands.

    Science.gov (United States)

    Michael, George A; Tapiero, Isabelle; Gálvez-García, Germán; Jacquot, Laurence

    2017-10-01

    Sensations and thoughts have been described as potentially related to self-awareness. We therefore asked whether sensations that arise in the absence of external triggers, i.e., spontaneous sensations (SPS), which were shown to relate to interoception and perception of the self, vary as a function of the individual propensity to generate spontaneous thoughts, i.e., mind-wandering. The Mind Wandering Questionnaire (MWQ) was used as a specific tool to assess the frequency and propensity to mind-wander several weeks before completing an SPS task. Correlational analyses between the MWQ score and SPS showed that greater propensity to mind-wander coincided with widespread perception of SPS, while lesser propensity to mind-wander coincided with more spatially restricted perception of SPS. The results are interpreted in light of the role of spontaneous thoughts and sensations in self-awareness. The potential psychological processes and the way they might regulate the relation between mind-wandering and the perception of SPS are discussed. Copyright © 2017 Elsevier Inc. All rights reserved.

  10. The MHV Lagrangian for a spontaneously broken gauge theory

    Science.gov (United States)

    Buchta, Sebastian; Weinzierl, Stefan

    2010-09-01

    Starting from the standard Lagrangian for a SU(2) × U(1) gauge theory plus a Higgs field we derive the corresponding "maximal helicity violating" (MHV) Lagrangian. From this MHV Lagrangian one deduces simple diagrammatic rules for the calculation of multi-particle scattering amplitudes. We arrive at the MHV Lagrangian by a canonical change of the field variables in the light-cone gauge. We comment on the modifications which occur in a spontaneously broken gauge theory as compared to a pure (unbroken) Yang-Mills theory.

  11. Biomarkers of spontaneous preterm birth

    DEFF Research Database (Denmark)

    Polettini, Jossimara; Cobo, Teresa; Kacerovsky, Marian

    2017-01-01

    predictors of pregnancy outcome. This systematic review was conducted to synthesize the knowledge on PTB biomarkers identified using multiplex analysis. Three electronic databases (PubMed, EMBASE and Web of Science) were searched for studies in any language reporting the use of multiplex assays for maternal......Despite decades of research on risk indicators of spontaneous preterm birth (PTB), reliable biomarkers are still not available to screen or diagnose high-risk pregnancies. Several biomarkers in maternal and fetal compartments have been mechanistically linked to PTB, but none of them are reliable......) followed by MIP-1β, GM-CSF, Eotaxin, and TNF-RI (two studies) were reported more than once in maternal serum. However, results could not be combined due to heterogeneity in type of sample, study population, assay, and analysis methods. By this systematic review, we conclude that multiplex assays...

  12. Spontaneous Strategies in Innovation Networks

    DEFF Research Database (Denmark)

    Plesner, Ursula; Husted, Emil Krastrup

    and a site ontology, we show how physical sites and objects become constitutive of the inside of virtual worlds through innovation processes. This argument is in line with ANT’s perspective on strategy, where sites and objects are considered a strategically relevant resource in the innovation process...... of materiality in relation to the organization and structuring of virtual worlds. We examine various innovation processes in five Danish entrepreneurial companies where actors continuously struggle to stabilize virtual worlds as platforms for professional communication. With inspiration from actor-network theory....... Empirically, the analysis is founded on descriptive accounts from the five entrepreneurs. By highlighting the spontaneous strategies described by actors, we show how sites and objects are actively used as an element in their strategy, and also how the sites and objects end up facilitating new ways of thinking...

  13. Recurrent spontaneous attacks of dizziness.

    Science.gov (United States)

    Lempert, Thomas

    2012-10-01

    This article describes the common causes of recurrent vertigo and dizziness that can be diagnosed largely on the basis of history. Ninety percent of spontaneous recurrent vertigo and dizziness can be explained by six disorders: (1) Ménière disease is characterized by vertigo attacks, lasting 20 minutes to several hours, with concomitant hearing loss, tinnitus, and aural fullness. Aural symptoms become permanent during the course of the disease. (2) Attacks of vestibular migraine may last anywhere from minutes to days. Most patients have a previous history of migraine headaches, and many experience migraine symptoms during the attack. (3) Vertebrobasilar TIAs affect older adults with vascular risk factors. Most attacks last less than 1 hour and are accompanied by other symptoms from the posterior circulation territory. (4) Vestibular paroxysmia is caused by vascular compression of the eighth cranial nerve. It manifests itself with brief attacks of vertigo that recur many times per day, sometimes with concomitant cochlear symptoms. (5) Orthostatic hypotension causes brief episodes of dizziness lasting seconds to a few minutes after standing up and is relieved by sitting or lying down. In older adults, it may be accompanied by supine hypertension. (6) Panic attacks usually last minutes, occur in specific situations, and are accompanied by choking, palpitations, tremor, heat, and anxiety. Less common causes of spontaneous recurrent vertigo and dizziness include perilymph fistula, superior canal dehiscence, autoimmune inner ear disease, otosclerosis, cardiac arrhythmia, and medication side effects. Neurologists need to venture into otolaryngology, internal medicine, and psychiatry to master the differential diagnosis of recurrent dizziness.

  14. Crows spontaneously exhibit analogical reasoning.

    Science.gov (United States)

    Smirnova, Anna; Zorina, Zoya; Obozova, Tanya; Wasserman, Edward

    2015-01-19

    Analogical reasoning is vital to advanced cognition and behavioral adaptation. Many theorists deem analogical thinking to be uniquely human and to be foundational to categorization, creative problem solving, and scientific discovery. Comparative psychologists have long been interested in the species generality of analogical reasoning, but they initially found it difficult to obtain empirical support for such thinking in nonhuman animals (for pioneering efforts, see [2, 3]). Researchers have since mustered considerable evidence and argument that relational matching-to-sample (RMTS) effectively captures the essence of analogy, in which the relevant logical arguments are presented visually. In RMTS, choice of test pair BB would be correct if the sample pair were AA, whereas choice of test pair EF would be correct if the sample pair were CD. Critically, no items in the correct test pair physically match items in the sample pair, thus demanding that only relational sameness or differentness is available to support accurate choice responding. Initial evidence suggested that only humans and apes can successfully learn RMTS with pairs of sample and test items; however, monkeys have subsequently done so. Here, we report that crows too exhibit relational matching behavior. Even more importantly, crows spontaneously display relational responding without ever having been trained on RMTS; they had only been trained on identity matching-to-sample (IMTS). Such robust and uninstructed relational matching behavior represents the most convincing evidence yet of analogical reasoning in a nonprimate species, as apes alone have spontaneously exhibited RMTS behavior after only IMTS training. Copyright © 2015 Elsevier Ltd. All rights reserved.

  15. Spontaneous ignition of biodiesel: A potential fire risk

    Directory of Open Access Journals (Sweden)

    Shibata Yasuhito

    2008-01-01

    Full Text Available The spontaneous ignition of biodiesel was for the first time suspected to be the cause of a recent fire in Japan. We herein present experimental evidence implying this potential risk of biodiesel. Thus, three independent biodiesel samples were subjected to a series of experiments, including a thermogravimetry-differential thermal analysis, a differential scanning calorimetry analysis and a modified wire basket test. The results were comparatively evaluated with reference to vegetable oils, of which spontaneous ignition has been well reported as a cause of fires. The heat onset temperature of biodiesel samples was determined to be ~100 °C, which was ~45 °C lower than those of vegetable oils. Furthermore, under the isothermal condition at 100 °C, the inner temperature of biodiesel samples rose rapidly with the generation of smoke after short induction periods owing to their exothermal decomposition, whereas for vegetable oils neither change in the inside temperature nor generation of smoke was observed even after 10 hours. It was therefore concluded that biodiesel possesses the higher risk of spontaneous ignition than vegetable oils. This is very important information to minimize the fire risk in biodiesel production facilities and so on. .

  16. Generating single microwave photons in a circuit.

    Science.gov (United States)

    Houck, A A; Schuster, D I; Gambetta, J M; Schreier, J A; Johnson, B R; Chow, J M; Frunzio, L; Majer, J; Devoret, M H; Girvin, S M; Schoelkopf, R J

    2007-09-20

    Microwaves have widespread use in classical communication technologies, from long-distance broadcasts to short-distance signals within a computer chip. Like all forms of light, microwaves, even those guided by the wires of an integrated circuit, consist of discrete photons. To enable quantum communication between distant parts of a quantum computer, the signals must also be quantum, consisting of single photons, for example. However, conventional sources can generate only classical light, not single photons. One way to realize a single-photon source is to collect the fluorescence of a single atom. Early experiments measured the quantum nature of continuous radiation, and further advances allowed triggered sources of photons on demand. To allow efficient photon collection, emitters are typically placed inside optical or microwave cavities, but these sources are difficult to employ for quantum communication on wires within an integrated circuit. Here we demonstrate an on-chip, on-demand single-photon source, where the microwave photons are injected into a wire with high efficiency and spectral purity. This is accomplished in a circuit quantum electrodynamics architecture, with a microwave transmission line cavity that enhances the spontaneous emission of a single superconducting qubit. When the qubit spontaneously emits, the generated photon acts as a flying qubit, transmitting the quantum information across a chip. We perform tomography of both the qubit and the emitted photons, clearly showing that both the quantum phase and amplitude are transferred during the emission. Both the average power and voltage of the photon source are characterized to verify performance of the system. This single-photon source is an important addition to a rapidly growing toolbox for quantum optics on a chip.

  17. Neutron angular distribution in plutonium-240 spontaneous fission

    Energy Technology Data Exchange (ETDEWEB)

    Marcath, Matthew J., E-mail: mmarcath@umich.edu [Department of Nuclear Engineering and Radiological Sciences, University of Michigan, 2355 Bonisteel Boulevard, Ann Arbor, MI 48109 (United States); Shin, Tony H.; Clarke, Shaun D. [Department of Nuclear Engineering and Radiological Sciences, University of Michigan, 2355 Bonisteel Boulevard, Ann Arbor, MI 48109 (United States); Peerani, Paolo [European Commission at the Joint Research Centre, Ispra (Italy); Pozzi, Sara A. [Department of Nuclear Engineering and Radiological Sciences, University of Michigan, 2355 Bonisteel Boulevard, Ann Arbor, MI 48109 (United States)

    2016-09-11

    Nuclear safeguards applications require accurate fission models that exhibit prompt neutron anisotropy. In the laboratory reference frame, an anisotropic neutron angular distribution is observed because prompt fission neutrons carry momentum from fully accelerated fission fragments. A liquid organic scintillation detector array was used with pulse shape discrimination techniques to produce neutron-neutron cross-correlation time distributions and angular distributions from spontaneous fission in a {sup 252}Cf, a 0.84 g {sup 240}Pu{sub eff} metal, and a 1.63 g {sup 240}Pu{sub eff} metal sample. The effect of cross-talk, estimated with MCNPX-PoliMi simulations, is removed from neutron-neutron coincidences as a function of the angle between detector pairs. Fewer coincidences were observed at detector angles near 90°, relative to higher and lower detector angles. As light output threshold increases, the observed anisotropy increases due to spectral effects arising from fission fragment momentum transfer to emitted neutrons. Stronger anisotropy was observed in Cf-252 spontaneous fission prompt neutrons than in Pu-240 neutrons. - Highlights: • Pu-240 prompt fission fast-neutron anisotropy was quantified for the first time. • MCNPX-PoliMi and MPPost codes were used to remove cross-talk neutron detections from experiment results. • Cf-252 spontaneous fission neutrons were found to be more anisotropic than Pu-240 neutrons.

  18. White light generation from YAG/YAM:Ce{sup 3+}, Pr{sup 3+}, Cr{sup 3+} nanophosphors mixed with a blue dye under 340 nm excitation

    Energy Technology Data Exchange (ETDEWEB)

    Oliva, J. [Centro de Investigaciones en Optica, A.P. 1-948, León, Gto 37150, México (Mexico); De la Rosa, E., E-mail: elder@cio.mx [Centro de Investigaciones en Optica, A.P. 1-948, León, Gto 37150, México (Mexico); Diaz-Torres, L.A [Centro de Investigaciones en Optica, A.P. 1-948, León, Gto 37150, México (Mexico); Torres, A. [Universidad Autónoma de Nuevo León, A.P. 126-F, Monterrey, NL 66450, México (Mexico); Salas, P. [Centro de Física Aplicada y Tecnología Avanzada, Universidad Nacional Autónoma de México, A.P. 1-1010, Juriquilla, Qro. 76000, México (Mexico); Meza, O. [Benemérita Universidad Autónoma de Puebla, 4 Sur 104 Centro Historico, 72000 Puebla, México (Mexico)

    2014-10-15

    The structural and luminescent properties of Y{sub 3}Al{sub 5}O{sub 12}/Y{sub 4}Al{sub 2}O{sub 9}:Ce{sup 3+}(0.1%)–Pr{sup 3+}(0.1%) –Cr{sup 3+} (trace impurities) nanophosphors synthesized by a simple hydrothermal method were studied. The crystalline phase was composed of Yttrium Aluminum Garnet (YAG) and Yttrium Aluminum Monoclinic (YAM) depending on the ammonia concentration and annealing temperature. Ammonia increased the stabilization of YAG from 55 wt% to 63 wt% in the samples annealed at 900 °C, and an increment of 83% of the overall emission under 460 nm excitation was observed. Quenching of the emitted signal after annealing at 1100 °C was observed in spite of single YAG crystalline phase stabilization, due to the formation of Ce{sup 4+}, Pr{sup 4+}, and color centers. In addition to the green–yellow emission from Ce{sup 3+}, all samples present a broad red emission band produced by the relaxations from the broad band {sup 4}T{sub 2} toward the {sup 4}A{sub 2} energy level of Cr{sup 3+} impurities, under 340 nm excitation. By taking advantage of this broad green–yellow–red emission and using a blue dye, white light with CIE coordinates of (0.30, 0.36) under 340 nm excitation was produced. - Highlights: • YAG/YAM:Ce{sup 3+}, Pr{sup 3+}, Cr{sup 3+} nanophosphors were synthesized with a hydrothermal method. • Ammonia introduced during the synthesis increased the emission of nanophosphors. • White light was obtained by combining the emissions of a blue dye and nanophosphors. • The CIE coordinates for this white light are (0.30, 0.36)

  19. Associations of light and moderate maternal alcohol consumption with fetal growth characteristics in different periods of pregnancy: the Generation R Study.

    Science.gov (United States)

    Bakker, Rachel; Pluimgraaff, Liane E; Steegers, Eric A P; Raat, Hein; Tiemeier, Henning; Hofman, Albert; Jaddoe, Vincent W V

    2010-06-01

    Excessive alcohol consumption during pregnancy has adverse effects on fetal growth and development. Less consistent associations have been shown for the associations of light-to-moderate maternal alcohol consumption during pregnancy with health outcomes in the offspring. Therefore, we examined the associations of light-to-moderate maternal alcohol consumption with various fetal growth characteristics measured in different periods of pregnancy. This study was based on 7333 pregnant women participating in a population-based cohort study. Alcohol consumption habits and fetal growth were assessed in early (gestational age or =25 weeks). We assessed the effects of different categories of alcohol consumption (no; less than one drink per week; one to three drinks per week; four to six drinks per week; one drink per day and two to three drinks per day) on repeatedly measured fetal head circumference, abdominal circumference and femur length. In total, 37% of all mothers continued alcohol consumption during pregnancy, of whom the majority used less than three drinks per week. We observed no differences in growth rates of fetal head circumference, abdominal circumference or femur length between mothers with and without continued alcohol consumption during pregnancy. Compared with mothers without alcohol consumption, mothers with continued alcohol consumption during pregnancy had an increased fetal weight gain [difference 0.61 g (95% confidence interval: 0.18, 1.04) per week]. Cross-sectional analyses in mid- and late pregnancy showed no consistent associations between the number of alcoholic consumptions and fetal growth characteristics. All analyses were adjusted for potential confounders. Light-to-moderate maternal alcohol consumption during pregnancy does not adversely affect fetal growth characteristics. Further studies are needed to assess whether moderate alcohol consumption during pregnancy influences organ growth and function in postnatal life.

  20. Audio-visual Classification and Fusion of Spontaneous Affect Data in Likelihood Space

    NARCIS (Netherlands)

    Nicolaou, Mihalis A.; Gunes, Hatice; Pantic, Maja

    2010-01-01

    This paper focuses on audio-visual (using facial expression, shoulder and audio cues) classification of spontaneous affect, utilising generative models for classification (i) in terms of Maximum Likelihood Classification with the assumption that the generative model structure in the classifier is

  1. Ensemble spontaneous activity alterations detected by CISA approach.

    Science.gov (United States)

    Boudaoud, Sofiane; Rix, Hervé; Meste, Olivier; Cazals, Yves

    2007-01-01

    In this paper, we propose a method for detecting alterations in the Ensemble Spontaneous Activity (ESA), a random signal representing the composite spontaneous contribution of the auditory nerve recorded on the round window. The proposed method is based on shape analysis of the ESA amplitude histogram. For this task, we use a recent approach, the Corrected Integral Shape Averaging (CISA). Using this approach, a shape clustering algorithm is proposed to classify healthy and pathological ESA signals generated by a recent ESA model. This model allows a precise simulation of neural mechanisms occurring in the auditory nerve. The obtained results demonstrate that this shape analysis is very sensitive for detecting a small number of fibers with correlated firing, supposed to occur during a particular type of tinnitus. In comparison, the classical spectral index fails in this detection.

  2. Inertial Spontaneous Symmetry Breaking and Quantum Scale Invariance

    Energy Technology Data Exchange (ETDEWEB)

    Ferreira, Pedro G. [Oxford U.; Hill, Christopher T. [Fermilab; Ross, Graham G. [Oxford U., Theor. Phys.

    2018-01-23

    Weyl invariant theories of scalars and gravity can generate all mass scales spontaneously, initiated by a dynamical process of "inertial spontaneous symmetry breaking" that does not involve a potential. This is dictated by the structure of the Weyl current, $K_\\mu$, and a cosmological phase during which the universe expands and the Einstein-Hilbert effective action is formed. Maintaining exact Weyl invariance in the renormalised quantum theory is straightforward when renormalisation conditions are referred back to the VEV's of fields in the action of the theory, which implies a conserved Weyl current. We do not require scale invariant regulators. We illustrate the computation of a Weyl invariant Coleman-Weinberg potential.

  3. Spontaneous Bacterial Peritonitis Caused by Infection with Listeria monocytogenes

    Directory of Open Access Journals (Sweden)

    Michael Vincent F. Tablang

    2008-11-01

    Full Text Available Spontaneous bacterial peritonitis is a severe and life-threatening complication in patients with ascites caused by advanced liver disease. The organisms most commonly involved are coliform bacteria and third-generation cephalosporins are the empiric antibiotics of choice. This is an uncommon case of spontaneous bacterial peritonitis caused by Listeria monocytogenes in a female patient with liver cirrhosis from autoimmune hepatitis. She did not improve with ceftriaxone and her course was complicated by hepatic encephalopathy, seizures and multi-organ failure. This case emphasizes that a high index of suspicion should be maintained for timely diagnosis and treatment. Listerial peritonitis should be suspected in patients with end-stage liver disease and inadequate response to conventional antibiotics within 48–72 h. Ampicillin/sulbactam should be initiated while awaiting results of ascitic fluid or blood culture.

  4. Stabiliteit spontane taal bij chronische milde afasie

    NARCIS (Netherlands)

    Wolthuis, Nienke; Mendez Orellana, Carolina; Nouwens, Femke; Jonkers, Roel; Visch-Brink, Evy; Bastiaanse, Roelien

    2014-01-01

    In aphasia, an analysis of spontaneous speech provides opportunities to establish the linguistic and communicative abilities, to create suitable therapy plans and to measure language progress. The current study investigated the stability of spontaneous speech within an interview of ten mild aphasic

  5. Spontaneously broken abelian gauge invariant supersymmetric model

    International Nuclear Information System (INIS)

    Mainland, G.B.; Tanaka, K.

    A model is presented that is invariant under an Abelian gauge transformation and a modified supersymmetry transformation. This model is broken spontaneously, and the interplay between symmetry breaking, Goldstone particles, and mass breaking is studied. In the present model, spontaneously breaking the Abelian symmetry of the vacuum restores the invariance of the vacuum under a modified supersymmetry transformation. (U.S.)

  6. Spontaneous Achilles tendon rupture in alkaptonuria | Mohammed ...

    African Journals Online (AJOL)

    Spontaneous Achilles tendon ruptures are uncommon. We present a 46-year-old man with spontaneous Achilles tendon rupture due to ochronosis. To our knowledge, this has not been previously reported in Sudan literature. The tendon of the reported patient healed well after debridement and primary repairs.

  7. Spontaneous rupture of choledochal cyst: case report

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Ho Seob; Nam, Kyung Jin; Lee, Jin Hwa; Kim, Chan Sung; Choi, Jong Cheol; Oh, Jong Young [Dong-a University College of Medicine, Pusan (Korea, Republic of)

    2002-11-01

    Spontaneous rupture of a choledochal cyst leading to biliary peritonitis is a rare complication which can be fatal if not promptly diagnosed. The authors report the ultrasound and CT findings of two cases of spontaneous choledochal cystic rupture and the biliary peritonitis which ensued.

  8. Spontaneity and Equilibrium II: Multireaction Systems

    Science.gov (United States)

    Raff, Lionel M.

    2014-01-01

    The thermodynamic criteria for spontaneity and equilibrium in multireaction systems are developed and discussed. When N reactions are occurring simultaneously, it is shown that G and A will depend upon N independent reaction coordinates, ?a (a = 1,2, ..., N), in addition to T and p for G or T and V for A. The general criteria for spontaneity and…

  9. Efficient generation of 1.9  W yellow light by cascaded frequency doubling of a distributed Bragg reflector tapered diode

    DEFF Research Database (Denmark)

    Hansen, Anders Kragh; Christensen, Mathias; Noordegraaf, Danny

    2016-01-01

    Watt-level yellow emitting lasers are interesting for medical applications, due to their high hemoglobin absorption, and for efficient detection of certain fluorophores. In this paper, we demonstrate a compact and robust diode-based laser system in the yellow spectral range. The system generates ...

  10. The effects of hydrothermal temperature on the photocatalytic performance of ZnIn2S4 for hydrogen generation under visible light irradiation

    International Nuclear Information System (INIS)

    Tian, Fei; Zhu, Rongshu; Song, Kelin; Niu, Minli; Ouyang, Feng; Cao, Gang

    2015-01-01

    Highlights: • The ZnIn 2 S 4 (120, 140, 160, 180, and 200 °C) was prepared. • The activities splitting water to hydrogen under visible light were evaluated. • The activity achieved the best when hydrothermal temperature was 160 °C. • The activity order is related to the surface morphology and surface defects. - Abstract: A series of ZnIn 2 S 4 photocatalysts were successfully synthesized using the hydrothermal method with different hydrothermal temperatures (120, 140, 160, 180, and 200 °C) and characterized by various analysis techniques, such as UV–vis, XRD, SEM, BET and PL. The results indicated that these photocatalysts had a similar band gap. The hydrothermal temperature had a huge influence on the properties of the photocatalysts such as the BET surface area, the total pore volume, the average pore diameter, the defects and the morphology. The photocatalytic activities of ZnIn 2 S 4 were evaluated based on photocatalytic hydrogen production from water under visible-light irradiation. The activity order is attributed to the coefficient of the surface morphology and the surface defects. The hydrogen production efficiency achieved the best when the hydrothermal temperature was 160 °C. On the basis of the characterization of the catalysts, the effects of the hydrothermal temperature on the photocatalytic activity of ZnIn 2 S 4 were discussed

  11. Early pregnancy angiogenic markers and spontaneous abortion

    DEFF Research Database (Denmark)

    Andersen, Louise B; Dechend, Ralf; Karumanchi, S Ananth

    2016-01-01

    BACKGROUND: Spontaneous abortion is the most commonly observed adverse pregnancy outcome. The angiogenic factors soluble Fms-like kinase 1 and placental growth factor are critical for normal pregnancy and may be associated to spontaneous abortion. OBJECTIVE: We investigated the association between...... maternal serum concentrations of soluble Fms-like kinase 1 and placental growth factor, and subsequent spontaneous abortion. STUDY DESIGN: In the prospective observational Odense Child Cohort, 1676 pregnant women donated serum in early pregnancy, gestational week ..., interquartile range 71-103). Concentrations of soluble Fms-like kinase 1 and placental growth factor were determined with novel automated assays. Spontaneous abortion was defined as complete or incomplete spontaneous abortion, missed abortion, or blighted ovum

  12. Non-exponential spontaneous emission dynamics for emitters in a time-dependent optical cavity

    NARCIS (Netherlands)

    Thyrrestrup Nielsen, Henri; Hartsuiker, A.; Gerard, J.M.; Vos, Willem L.

    2013-01-01

    We have theoretically studied the effect of deterministic temporal control of spontaneous emission in a dynamic optical microcavity. We propose a new paradigm in light emission: we envision an ensemble of two-level emitters in an environment where the local density of optical states is modified on a

  13. Light Pollution

    Science.gov (United States)

    Riegel, Kurt W.

    1973-01-01

    Outdoor lighting is light pollution which handicaps certain astronomical programs. Protective measures must be adopted by the government to aid observational astronomy without sacrificing legitimate outdoor lighting needs. (PS)

  14. Estimating spontaneous mutation rates at enzyme loci in Drosophila melanogaster

    International Nuclear Information System (INIS)

    Mukai, Terumi; Yamazaki, Tsuneyuki; Harada, Ko; Kusakabe, Shin-ichi

    1990-04-01

    Spontaneous mutations were accumulated for 1,620,826 allele-generations on chromosomes that originated from six stem second chromosomes of Drosophila melanogaster. Only null-electromorph mutations were detected. Band-electromorph mutations were not found. The average rate of null-electromorph mutations was 2.71 x 10 -5 per locus per generation. The 95% confidence interval (μ n ) was 1.97 x 10 -5 n -5 per locus per generation. The upper 95% confidence limit of the band-electromorph mutation rate (μ B ) was 2.28 x 10 -6 per locus per generation. It appeared that null mutations were induced by movable genetic elements and that the mutation rates were different from chromosome to chromosome. (author)

  15. LED lighting and the Next Generation of Greenhouse for Tomatoes. Proof of Principle; LED belichting en Het Nieuwe Telen bij tomaat. Proof of Principle

    Energy Technology Data Exchange (ETDEWEB)

    Dueck, T.; Janse, J.; Eveleens, B. [Wageningen UR Glastuinbouw, Wageningen (Netherlands); Nieboer, S.; Valstar, W.; Grootscholten, M. [GreenQ Improvement Centre, Bleiswijk (Netherlands)

    2012-08-15

    In this Proof of Principle project a tomato crop was grown under artificial lighting with the aim of 30% energy saving at the same level of production. Tomatoes (cultivar Komeett) were illuminated with 110 {mu}mol m{sup -2} s{sup -1} HPS (High Pressure Sodium) above the crop and 85 {mu}mol m{sup -2} s{sup -1} LED interlighting. The LEDs hung in 2 rows, approximately 40 cm above the lower leaves and the second strand at 40 or 70 cm above that. There were two types of LEDs used: production LEDs (light efficiency 1.6 {mu}mol m{sup -2} s{sup -1}, 87% red/13% blue) and inter-lighting LEDs (light efficiency 1.9 {mu}mol m{sup -2} s{sup -1}, 95% red/5% blue), with the same light intensity. At the start, the crop was given as much light as it could handle, and because the crop developed so well, the stem density was increased relatively early. This resulted in high fruit load, while insufficient light was available to compensate for the low levels of sunlight in the winter. In the 192 cm row spacing system the plants were too close to each other. Additional problems occurred with trace elements, lesser bumble bee activity, and a moist greenhouse climate which weakened the crop in the winter. Thus Botrytis occurred on the leaves and stems. The crop struggled with its recovery until early spring with more sunlight. Compared to a reference crop with 79 kg m{sup -2} tomatoes, 75 kg m{sup -2} were produced under-production LEDs, and 80 kg m{sup -2} under the interlighting LEDs, mainly because latter LEDs were used longer during the summer. 30% of the energy for dehumidification and heat energy, and 27% of the electricity was saved, relative to the reference crop. Thus it appears possible to save 30% energy with a near identical production [Dutch] In dit Proof of Principle project is een belichte tomatenteelt geteeld met als doel 30% energiebesparing bij een gelijke productie. Tomaten van het ras Komeett werden belicht met 110 {mu}mol m{sup -2} s{sup -1} SON-T belichting boven

  16. Thrombin generation, ProC(®)Global, prothrombin time and activated partial thromboplastin time in thawed plasma stored for seven days and after methylene blue/light pathogen inactivation.

    Science.gov (United States)

    Thiele, Thomas; Hron, Gregor; Kellner, Sarah; Wasner, Christina; Westphal, Antje; Warkentin, Theodore E; Greinacher, Andreas; Selleng, Kathleen

    2016-01-01

    Methylene blue pathogen inactivation and storage of thawed plasma both lead to changes in the activity of several clotting factors. We investigated how this translates into a global loss of thrombin generation potential and alterations in the protein C pathway. Fifty apheresis plasma samples were thawed and each divided into three subunits. One subunit was stored for 7 days at 4 °C, one was stored for 7 days at 22 °C and one was stored at 4 °C after methylene blue/light treatment. Thrombin generation parameters, ProC(®)Global-NR, prothrombin time and activated partial thromboplastin time were assessed on days 0 and 7. The velocity of thrombin generation increased significantly after methylene blue treatment (increased thrombin generation rate; time to peak decreased) and decreased after storage (decreased thrombin generation rate and peak thrombin; increased lag time and time to peak). The endogenous thrombin generation potential remained stable after methylene blue treatment and storage at 4 °C. Methylene blue treatment and 7 days of storage at 4 °C activated the protein C pathway, whereas storage at room temperature and storage after methylene blue treatment decreased the functional capacity of the protein C pathway. Prothrombin time and activated partial thromboplastin time showed only modest alterations. The global clotting capacity of thawed plasma is maintained at 4 °C for 7 days and directly after methylene blue treatment of thawed plasma. Thrombin generation and ProC(®)Global are useful tools for investigating the impact of pathogen inactivation and storage on the clotting capacity of therapeutic plasma preparations.

  17. Competition for light and water increases tree carbon allocation to fine roots and leaves in a next-generation dynamic vegetation model

    Science.gov (United States)

    Lichstein, J. W.; Zhang, T.; Weng, E.; Farrior, C.; Dybzinski, R.; Birdsey, R.; Pacala, S. W.

    2015-12-01

    The response of the terrestrial carbon (C) cycle to climate change is a key uncertainty in land models. An important component of this uncertainty concerns plant functional diversity, which is typically represented in land models by ~10 functional types (PFTs) with fixed traits. However, few land models include the individual-level competitive mechanisms that largely determine how plant functional traits are distributed in time and space in real ecosystems. We have developed a new land model that represents height-structured competition for light with a simple canopy space-filling algorithm, the perfect plasticity approximation (PPA). The new land model, LM3-PPA, allows for an arbitrary number of PFTs (or 'species') whose spatial-temporal distributions are determined by the outcome of competition for light and water. We performed experiments with a modified version of LM3-PPA in 10 eastern U.S. grid cells and across simulated precipitation gradients to determine how competition for light and water affects tree C allocation to leaves, fine roots, and wood across climate gradients and in response to episodic drought. We studied the performance of 16 allocational types ('species') in monoculture and in competition with each other to determine the competitively-optimal, NPP-maximizing, and biomass-maximizing C allocation strategy under different environmental conditions. Under chronically moist conditions, competitively-optimal, NPP-maximizing, and biomass-maximizing trees all had similar C allocation. However, under chronically dry conditions, competitively-optimal trees allocated more C to both fine roots and leaves, and less C to wood, compared to NPP- or biomass-maximizing strategies. When subject to episodic drought, the most drought-tolerant allocational strategies had relatively low allocation to leaves (and thus low leaf area and low water demand). Thus, the "over-investment" in leaves that results from resource competition increases the vulnerability of

  18. Comparison of silorane and methacrylate-based composites on the polymerization heat generated with different light-curing units and dentin thicknesses.

    Science.gov (United States)

    Guiraldo, Ricardo Danil; Consani, Simonides; Consani, Rafael Leonardo Xediek; Berger, Sandrine Bittencourt; Correr, Américo Bortolazzo; Sinhoreti, Mário Alexandre Coelho; Correr-Sobrinho, Lourenço

    2013-01-01

    This study evaluated the temperature variation in the pulp chamber during photoactivation of two restorative composite resins (Filtek P90 silorane-based composite and Heliomolar methacrylate-based composite) with either a quartz-tungsten-halogen (QTH) or light-emitting diodes (LED) light-curing unit (LCU) and using dentin thicknesses (0.5 and 1.0 mm). Standardized cavities (2x2x2 mm) were prepared in 80 bovine incisors, which were randomly assigned to 8 groups according to the photoactivation method and dentin thickness. Filtek P90 and Heliomolar (both in shade A3) were used with their respective adhesive systems (P90 self-etch primer / P90 adhesive bond and Excite adhesive). All experiments were carried out in a controlled environment (37°C). The temperature variations (°C) were recorded using a digital thermometer attached to a K-type thermocouple. The results were analyzed statistically by ANOVA and Tukey's test (α=0.05). For composite/dentin thickness interaction, temperature increase was significantly higher in 0.5 mm dentin thickness (40.07°C) compared with 1.0 mm dentin thickness (39.61°C) for Filtek P90. For composite/LCU interaction, the temperature increase was significantly higher for Filtek P90 (39.21°C - QTH and 40.47°C - LED) compared with Heliomolar (38.40°C - QTH and 39.30°C - LED). The silorane-based composite promoted higher temperature increase in the pulp chamber than the methacrylate-based composite.

  19. Modulation of neutrophil superoxide generation by inhibitors of protein kinase C, calmodulin, diacylglycerol and myosin light chain kinases, and peptidyl prolyl cis-trans isomerase.

    Science.gov (United States)

    Bergstrand, H; Eriksson, T; Hallberg, A; Johansson, B; Karabelas, K; Michelsen, P; Nybom, A

    1992-12-01

    To assess the role of protein kinase C (PKC) in the respiratory burst of adherent human polymorphonuclear leukocytes (PMNL), reduction of ferricytochrome C by cells triggered with a phorbol ester (PMA), ionophore A23187, serum-treated zymosan (STZ) or three lipid derivatives, 3-decanoyl-sn-glycerol (G-3-OCOC9), (R,R)-1,4-diethyl-2-O-decyl-L-tartrate (Tt-2-OC10) and 3-decyloxy-5-hydroxymethylphenol (DHP) was examined in a microtiter plate procedure in the presence of inhibitors of PKC and, for comparison, inhibitors of calmodulin, diacylglycerol and myosin light chain kinases and the peptidyl-prolyl cis-trans isomerase activity of fujiphilin. 1) Of the protein kinase inhibitors examined, Ro 31-7549 and staurosporine reduced responses to all stimuli except possibly STZ; in contrast, K252a and the myosin light chain kinase inhibitors ML-7 and ML-9 blocked responses to A23187 and STZ better than those triggered by PMA. H-7 reduced responses to A23187, DHP and G-3-OCOC9, and calphostin, palmitoyl carnitine, sphingosine and the multifunctional drugs TMB-8 and W-7 reduced A23187; they also, when examined, reduced decane derivative-induced O2- production more effectively than PMA- and STZ-triggered responses. Polymyxin B, 4 alpha-PMA and retinal displayed no inhibitory capacity. 2) Of the selective calmodulin antagonists, CGS 9343B, Ro 22-4839 and calmidazolium did not inhibit the oxidative response irrespective of the stimulus used, whereas metofenazate reduced those evoked by A23187, DHP, G-3-OCOC9 and STZ.(ABSTRACT TRUNCATED AT 250 WORDS)

  20. Potential for electric power generation and gas lighting through the use of biogas from landfill; Potencial de geracao de energia eletrica e iluminacao a gas por meio do aproveitamento de biogas proveniente de aterro sanitario

    Energy Technology Data Exchange (ETDEWEB)

    Pecora, V.; Figueiredo, N.J.V.; Coelho, S.T. [Universidade de Sao Paulo (CENBIO/USP), SP (Brazil). Inst. de Eletrotecnica e Energia. Centro Nacional de Referencia em Biomassa; Velazquez, S.M.S.G. [Universidade Presbiteriana Mackenzie, Sao Paulo, SP (Brazil). Dept. de Engenharia Mecanica

    2008-07-01

    Global warming has become an important topic of global discussions due to the increasing concentration of greenhouse gases in the atmosphere, coming mainly on the burning of fossil fuels. The search for alternatives that promote the replacement of these fuels by renewable sources has been intensified in recent decades and several studies are being undertaken to ensure, for example, the efficient management and minimization of solid waste, seen as a serious problem of large Brazilians urban centers nowadays. The incorrect final disposal of solid waste entails in uncontrolled emission of gases, generated in its decomposition, and the infiltration of percolated liquid in the soil; resulting on negative impacts on people's health and on the environment, also contributing to the worsening of the greenhouse effect. In this context, this article presents the project of exploitation of biogas from the treatment of urban solid waste for generating electric power and gas lighting, developed by the Brazilian Reference Center on Biomass (CENBIO), at Caieiras Waste Treatment Centre (Essencis CTR - Caieiras). This paper describes the activities developed by CENBIO for determining the potential of electricity generation and gas lighting and, through the results, may be defined other landfills for implementation of a similar project. The use of biogas for energy generation provides the rational use of available sources, reducing dependence on external energy sources and, as the conversion of methane into carbon dioxide, promotes the reduction of emissions of greenhouse gases, since methane has the global warming potential about 20 times higher when compared to carbon dioxide. (author)