Science.gov

Sample records for 4th generation light

  1. Plasma-Based Studies on 4th Generation Light Sources

    SciTech Connect

    Lee, R W; Baldis, H A; Cauble, R C; Landen, O L; Wark, J S; Ng, A; Rose, S J; Lewis, C; Riley, D; Gauthier, J-C; Audebert, P

    2000-11-28

    The construction of a short pulse tunable x-ray laser source will be a watershed for plasma-based and warm dense matter research. The areas we will discuss below can be separated broadly into warn dense matter (WDM) research, laser probing of near solid density plasmas, and laser-plasma spectroscopy of ions in plasmas. The area of WDM refers to that part of the density-temperature phase space where the standard theories of condensed matter physics and/or plasma statistical physics are invalid. Warm dense matter, therefore, defines a region between solids and plasmas, a regime that is found in planetary interiors, cool dense stars, and in every plasma device where one starts from a solid, e.g., laser-solid matter produced plasma as well as all inertial fusion schemes. The study of dense plasmas has been severely hampered by the fact that laser-based methods have been unavailable. The single most useful diagnostic of local plasma conditions, e.g., the temperature (T{sub e}), the density (n{sub e}), and the ionization (Z), has been Thomson scattering. However, due to the fact that visible light will not propagate at electron densities, n{sub e}, {ge} 10{sup 22} cm{sup -3} implies dense plasmas can not be probed. The 4th generation sources, LCLS and Tesla will remove these restrictions. Laser-based plasma spectroscopic techniques have been used with great success to determine the line shapes of atomic transitions in plasmas, study the population kinetics of atomic systems embedded in plasmas, and look at redistribution of radiation. However. the possibilities end for plasmas with n{sub e} {ge} 10{sup 22} since light propagation through the medium is severely altered by the plasma. The entire field of high Z plasma kinetics from laser produced plasma will then be available to study with the tunable source.

  2. The 4th Generation Light Source at Jefferson Lab

    SciTech Connect

    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.

  3. A laboratory model of post-Newtonian gravity with high power lasers and 4th generation light sources

    NASA Astrophysics Data System (ADS)

    Gregori, G.; Levy, M. C.; Wadud, M. A.; Crowley, B. J. B.; Bingham, R.

    2016-04-01

    Using the post-Newtonian formalism of gravity, we attempt to calculate the x-ray Thomson scattering cross section of electrons that are accelerated in the field of a high intensity optical laser. We show that our results are consistent with previous calculations, suggesting that the combination of high power laser and 4th generation light sources may become a powerful platform to test models exploring high order corrections to the Newtonian gravity.

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

    SciTech Connect

    Bruni, C.; Couprie, M. E.; Chubar, O.; Loulergue, A.; Nahon, L.; Carre, B.; Garzella, D.; Labat, M.; Lambert, G.; Monot, P.; Jablonka, M.; Meot, F.; Ortega, J. M.; Nutarelli, D.

    2007-01-19

    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.

  5. Injector Beam Dynamics for a High-Repetition Rate 4th-Generation Light Source

    SciTech Connect

    Papadopoulos, C. F.; Corlett, J.; Emma, P.; Filippetto, D.; Penn, G.; Qiang, J.; Reinsch, M.; Sannibale, F.; Steier, C.; Venturini, M.; Wells, R.

    2013-05-20

    We report on the beam dynamics studies and optimization methods for a high repetition rate (1 MHz) photoinjector based on a VHF normal conducting electron source. The simultaneous goals of beamcompression and reservation of 6-dimensional beam brightness have to be achieved in the injector, in order to accommodate a linac driven FEL light source. For this, a parallel, multiobjective optimization algorithm is used. We discuss the relative merits of different injector design points, as well as the constraints imposed on the beam dynamics by technical considerations such as the high repetition rate.

  6. BEAM DYNAMICS STUDIES OF A HIGH-REPETITION RATE LINAC-DRIVER FOR A 4TH GENERATION LIGHT SOURCE

    SciTech Connect

    Ventturini, M.; Corlett, J.; Emma, P.; Papadopoulos, C.; Penn, G.; Placidi, M.; Qiang, J.; Reinsch, M.; Sannibale, F.; Steier, C.; Sun, C.; Wells, R.

    2012-05-18

    We present recent progress toward the design of a super-conducting linac driver for a high-repetition rate FEL-based soft x-ray light source. The machine is designed to accept beams generated by the APEX photo-cathode gun operating with MHz-range repetition rate and deliver them to an array of SASE and seeded FEL beamlines. We review the current baseline design and report results of beam dynamics studies.

  7. Testing quantum mechanics in non-Minkowski space-time with high power lasers and 4th generation light sources

    PubMed Central

    Crowley, B. J. B.; Bingham, R.; Evans, R. G.; Gericke, D. O.; Landen, O. L.; Murphy, C. D.; Norreys, P. A.; Rose, S. J.; Tschentscher, Th; Wang, C. H.-T; Wark, J. S.; Gregori, G.

    2012-01-01

    A common misperception of quantum gravity is that it requires accessing energies up to the Planck scale of 1019 GeV, which is unattainable from any conceivable particle collider. Thanks to the development of ultra-high intensity optical lasers, very large accelerations can be now the reached at their focal spot, thus mimicking, by virtue of the equivalence principle, a non Minkowski space-time. Here we derive a semiclassical extension of quantum mechanics that applies to different metrics, but under the assumption of weak gravity. We use our results to show that Thomson scattering of photons by uniformly accelerated electrons predicts an observable effect depending upon acceleration and local metric. In the laboratory frame, a broadening of the Thomson scattered x ray light from a fourth generation light source can be used to detect the modification of the metric associated to electrons accelerated in the field of a high power optical laser. PMID:22768381

  8. Probing ultra-fast processes with high dynamic range at 4th-generation light sources: Arrival time and intensity binning at unprecedented repetition rates

    PubMed Central

    Kovalev, S.; Green, B.; Golz, T.; Maehrlein, S.; Stojanovic, N.; Fisher, A. S.; Kampfrath, T.; Gensch, M.

    2017-01-01

    Understanding dynamics on ultrafast timescales enables unique and new insights into important processes in the materials and life sciences. In this respect, the fundamental pump-probe approach based on ultra-short photon pulses aims at the creation of stroboscopic movies. Performing such experiments at one of the many recently established accelerator-based 4th-generation light sources such as free-electron lasers or superradiant THz sources allows an enormous widening of the accessible parameter space for the excitation and/or probing light pulses. Compared to table-top devices, critical issues of this type of experiment are fluctuations of the timing between the accelerator and external laser systems and intensity instabilities of the accelerator-based photon sources. Existing solutions have so far been only demonstrated at low repetition rates and/or achieved a limited dynamic range in comparison to table-top experiments, while the 4th generation of accelerator-based light sources is based on superconducting radio-frequency technology, which enables operation at MHz or even GHz repetition rates. In this article, we present the successful demonstration of ultra-fast accelerator-laser pump-probe experiments performed at an unprecedentedly high repetition rate in the few-hundred-kHz regime and with a currently achievable optimal time resolution of 13 fs (rms). Our scheme, based on the pulse-resolved detection of multiple beam parameters relevant for the experiment, allows us to achieve an excellent sensitivity in real-world ultra-fast experiments, as demonstrated for the example of THz-field-driven coherent spin precession. PMID:28382317

  9. Probing ultra-fast processes with high dynamic range at 4th-generation light sources: Arrival time and intensity binning at unprecedented repetition rates.

    PubMed

    Kovalev, S; Green, B; Golz, T; Maehrlein, S; Stojanovic, N; Fisher, A S; Kampfrath, T; Gensch, M

    2017-03-01

    Understanding dynamics on ultrafast timescales enables unique and new insights into important processes in the materials and life sciences. In this respect, the fundamental pump-probe approach based on ultra-short photon pulses aims at the creation of stroboscopic movies. Performing such experiments at one of the many recently established accelerator-based 4th-generation light sources such as free-electron lasers or superradiant THz sources allows an enormous widening of the accessible parameter space for the excitation and/or probing light pulses. Compared to table-top devices, critical issues of this type of experiment are fluctuations of the timing between the accelerator and external laser systems and intensity instabilities of the accelerator-based photon sources. Existing solutions have so far been only demonstrated at low repetition rates and/or achieved a limited dynamic range in comparison to table-top experiments, while the 4th generation of accelerator-based light sources is based on superconducting radio-frequency technology, which enables operation at MHz or even GHz repetition rates. In this article, we present the successful demonstration of ultra-fast accelerator-laser pump-probe experiments performed at an unprecedentedly high repetition rate in the few-hundred-kHz regime and with a currently achievable optimal time resolution of 13 fs (rms). Our scheme, based on the pulse-resolved detection of multiple beam parameters relevant for the experiment, allows us to achieve an excellent sensitivity in real-world ultra-fast experiments, as demonstrated for the example of THz-field-driven coherent spin precession.

  10. Design of a Nb3Sn Magnet for a 4th Generation ECR Ion Source

    SciTech Connect

    Prestemon, S,; Trillaud, F.; Caspi, S.; Ferracin, P.; Sabbi, G. L.; Lyneis, C. M.; Leitner, D.; Todd, D. S.; Hafalia, R.

    2008-08-17

    The next generation of Electron Cyclotron Resonant (ECR) ion sources are expected to operate at a heating radio frequency greater than 40 GHz. The existing 3rd generation systems, exemplified by the state of the art system VENUS, operate in the 10-28 GHz range, and use NbTi superconductors for the confinement coils. The magnetic field needed to confine the plasma scales with the rf frequency, resulting in peak fields on the magnets of the 4th generation system in excess of 10 T. High field superconductors such as Nb{sub 3}Sn must therefore be considered. The magnetic design of a 4th. generation ECR ion source operating at an rf frequency of 56 GHz is considered. The analysis considers both internal and external sextupole configurations, assuming commercially available Nb{sub 3}Sn material properties. Preliminary structural design issues are discussed based on the forces and margins associated with the coils in the different configurations, leading to quantitative data for the determination of a final magnet design.

  11. [Analysis of the 4th generation outer space bred Angelica dahurica by FTIR spectroscopy].

    PubMed

    Zhu, Yan-ying; Wu, Peng-le; Liu, Mei-yi; Wang, Zhi-zhou; Guo, Xi-hua; Guan, Ying

    2012-03-01

    The major components of the 4th generation outer space bred angelica and the ground group were determined and analyzed by Fourier transform infrared spectroscopy (FTIR) and second derivative spectrum, considering the large mutation of the plants with space mutagenesis. The results show that the content of the coumarin (1741 cm(-1)), which is the main active components of the space angelica dahurica increased, and the content of the protein (1 459, 1 419 cm(-1)) and the fat (930 cm(-1)) increased slightly, whereas the content of the starch and the dietary fiber reduced drastically. There are obvious differences between the peak values of the second derivative spectra of the plants, revealing that the outer space angelica dahurica contained amine component at 1 279 cm(-1). Space mutation breeding is favor of breeding angelica with better idiosyncrasy.

  12. 4th generation of the 1st level surface detector trigger in the Pierre Auger Observator

    NASA Astrophysics Data System (ADS)

    Szadkowski, Z.

    The proposal of a new 4th generation of the Front-End with the advanced 1st level triggers for the Infill Array of the Pierre Auger Observatory and for the Auger North is described. Newest FPGA chips offer much higher capacity of logic registers and memories, as well as DSP blocks. The calibration channel, previously supported by an external dual-port RAM, has been fully implemented into FPGA chip, through a large internal memory. In turn DSP blocks allowed on implementation of much more sophisticated spectral trigger algorithms. A single chip simplified board design, newer architecture of FPGA reduced resouces utilization and power consumption. Higher sampling in the new Front- End in comparison with previous 40 MHz designs as well as free resources for new detection algotithms can be a good platform for CR radio detection technique at Auger enhancing a duty cycle for the detection of UHECR’s.

  13. Conditions for the generation of cytotoxic CD4+ Th cells that enhance CD8+ CTL-mediated tumor regression

    PubMed Central

    Li, Kunyu; Baird, Margaret; Yang, Jianping; Jackson, Chris; Ronchese, Franca; Young, Sarah

    2016-01-01

    Adoptive cell therapies (ACTs) using tumor-reactive T cells have shown clinical benefit and potential for cancer treatment. While the majority of the current ACT are focused on using CD8+ cytotoxic T lymphocytes (CTL), others have shown that the presence of tumor-reactive CD4+ T helper (Th) cells can greatly enhance the anti-tumor activity of CD8+ CTL. However, difficulties in obtaining adequate numbers of CD4+ Th cells through in vitro expansion can limit the application of CD4 Th cells in ACT. This study aims to optimize the culture conditions for mouse CD4 T cells to provide basic information for animal studies of ACT using CD4 T cells. Taking advantage of the antigen-specificity of CD4+ Th cells from OT-II transgenic mice, we examined different methodologies for generating antigen-specific CD4+ Th1 cells in vitro. We found that cells grown in complete advanced-DMEM/F12 medium supplemented with low-dose IL-2 and IL-7 induced substantial cell expansion. These Th cells were Th1-like, as they expressed multiple Th1-cytokines and exhibited antigen-specific cytotoxicity. In addition co-transfer of these CD4+ Th1-like cells with CD8+ CTL significantly enhanced tumor regression, leading to complete cure in 80% of mice bearing established B16-OVA. These observations indicate that the CD4+ Th1-like cells generated using the method we optimized are functionally active to eliminate their target cells, and can also assist CD8+ CTL to enhance tumor regression. The findings of this study provide valuable data for further research into in vitro expansion of CD4+ Th1-like cells, with potential applications to cancer treatment involving ACT. PMID:27588200

  14. Development of partially-coherent wavefront propagation simulation methods for 3rd and 4th generation synchrotron radiation sources

    NASA Astrophysics Data System (ADS)

    Chubar, Oleg; Berman, Lonny; Chu, Yong S.; Fluerasu, Andrei; Hulbert, Steve; Idir, Mourad; Kaznatcheev, Konstantine; Shapiro, David; Shen, Qun; Baltser, Jana

    2011-09-01

    Partially-coherent wavefront propagation calculations have proven to be feasible and very beneficial in the design of beamlines for 3rd and 4th generation Synchrotron Radiation (SR) sources. These types of calculations use the framework of classical electrodynamics for the description, on the same accuracy level, of the emission by relativistic electrons moving in magnetic fields of accelerators, and the propagation of the emitted radiation wavefronts through beamline optical elements. This enables accurate prediction of performance characteristics for beamlines exploiting high SR brightness and/or high spectral flux. Detailed analysis of radiation degree of coherence, offered by the partially-coherent wavefront propagation method, is of paramount importance for modern storage-ring based SR sources, which, thanks to extremely small sub-nanometer-level electron beam emittances, produce substantial portions of coherent flux in X-ray spectral range. We describe the general approach to partially-coherent SR wavefront propagation simulations and present examples of such simulations performed using "Synchrotron Radiation Workshop" (SRW) code for the parameters of hard X-ray undulator based beamlines at the National Synchrotron Light Source II (NSLS-II), Brookhaven National Laboratory. These examples illustrate general characteristics of partially-coherent undulator radiation beams in low-emittance SR sources, and demonstrate advantages of applying high-accuracy physical-optics simulations to the optimization and performance prediction of X-ray optical beamlines in these new sources.

  15. Reliability of a new 4th generation FloTrac algorithm to track cardiac output changes in patients receiving phenylephrine.

    PubMed

    Ji, Fuhai; Li, Jian; Fleming, Neal; Rose, David; Liu, Hong

    2015-08-01

    Phenylephrine is often used to treat intra-operative hypotension. Previous studies have shown that the FloTrac cardiac monitor may overestimate cardiac output (CO) changes following phenylephrine administration. A new algorithm (4th generation) has been developed to improve performance in this setting. We performed a prospective observational study to assess the effects of phenylephrine administration on CO values measured by the 3rd and 4th generation FloTrac algorithms. 54 patients were enrolled in this study. We used the Nexfin, a pulse contour method shown to be insensitive to vasopressor administration, as the reference method. Radial arterial pressures were recorded continuously in patients undergoing surgery. Phenylephrine administration times were documented. Arterial pressure recordings were subsequently analyzed offline using three different pulse contour analysis algorithms: FloTrac 3rd generation (G3), FloTrac 4th generation (G4), and Nexfin (nf). One minute of hemodynamic measurements was analyzed immediately before phenylephrine administration and then repeated when the mean arterial pressure peaked. A total of 157 (4.6 ± 3.2 per patient, range 1-15) paired sets of hemodynamic recordings were analyzed. Phenylephrine induced a significant increase in stroke volume (SV) and CO with the FloTrac G3, but not with FloTrac G4 or Nexfin algorithms. Agreement between FloTrac G3 and Nexfin was: 0.23 ± 1.19 l/min and concordance was 51.1%. In contrast, agreement between FloTrac G4 and Nexfin was: 0.19 ± 0.86 l/min and concordance was 87.2%. In conclusion, the pulse contour method of measuring CO, as implemented in FloTrac 4th generation algorithm, has significantly improved its ability to track the changes in CO induced by phenylephrine.

  16. Characterization of γ and γ' phases in 2nd and 4th generation single crystal nickel-base superalloys

    NASA Astrophysics Data System (ADS)

    Zietara, Maciej; Neumeier, Steffen; Göken, Mathias; Czyrska-Filemonowicz, Aleksandra

    2017-01-01

    A Ni based single crystal superalloy from the 2nd generation, PWA 1484, and one from the 4th generation, PWA 1497, were comparatively studied by scanning electron microscopy, energy dispersive X-ray spectroscopy and nanoindentation technique in an atomic force microscope (NI-AFM) after high temperature creep deformation. During primary creep of both generations of superalloys, γ' precipitates start to coalesce and grow directionally. Further creep deformation leads to the topological inversion and coarsening of the rafted microstructure. The NI-AFM technique was used for measurements of the hardness of the γ and γ' phases in as-received and creep deformed samples in various conditions. The g matrix of the PWA 1497 superalloy is on average 0.8 GPa harder than that of PWA 1484 that can be explained by higher content of Re and Ru, since they partition predominantly to the matrix phase.

  17. Rare decays of the Z and the standard model, 4th generation, and beyond

    SciTech Connect

    Weiler, T.J.

    1989-01-01

    Several issues in rare decays of the Z are addressed. The rate for flavor-changing Z decay grows as the fourth power of the fermion masses internal to the quantum loop, and so offers a window to the existence of ultraheavy (m > M{sub W}) fermions. In the standard model, with three generations, BR(Z {yields} bs) < 10{sup -7} and BR(Z{yields}tc)<10{sup -13}. With four generations, BR(Z {yields} bb{sub 4}) may be as large as 10{sup -5} if m{sub b4} < M{sub Z}; and similarly for BR(Z {yields} N{sub 4}v), where N{sub 4} is the possibly heavy fourth generation neutrino. In supersymmetric and other two Higgs doublet models, BR(Z {yields} tc) may be as large as 5 {times} 10{sup -6} in the three generation scheme. With minimal supersymmetry, the reaction Z {yields} H{gamma} is guaranteed to go, with a parameter-dependent branching ratio of 10{sup -6 {plus minus} 3}. With mirror fermions or exotic E{sub 6} fermions, the branching ratios for Z {yields} ct (70 GeV), Z {yields} {mu}{tau}, and Z {yields} bb{sub 4} (70 GeV) are typically 10{sup -4}, 10{sup -4}, and 10{sup -3} respectively, clearly measurable at LEP. Depending on unknown quark masses, the Z may mix with vector (b{sub 4}{bar b}{sub 4}) and the W may mix with vector (t{bar b}) or (t{bar s}). CP violating asymmetries in flavor-changing Z decay are immeasurably small in the standard model, but may be large in supersymmetric and other nonstandard models. 28 refs.

  18. Battling the "Hydra": Changing Operational Factors in 4th Generation War

    DTIC Science & Technology

    2007-11-02

    challenging us to change current doctrine and attempts to reduce war to algebraic formulae. Current Operational Doctrine Operational art, as advanced...over terrain -- the image and concept of ’classic’ war. A- 2 Armies turned to ’science," relying upon mathematical probabilities and algebraic formulae...Jominian war of algebraic formula and mathematical probabilities, vice accepting the 3d generation premise to cause and thrive within chaos. Lacking

  19. 4th Annual SATN Conference 2011: Curriculum Transformation at Universities of Technology: Towards Development of New Generation Universities

    ERIC Educational Resources Information Center

    Mthembu, T.

    2012-01-01

    The South African Technology Network (SATN) would like to thank the Editor of the "South African Journal of Higher Education" (SAJHE) for the opportunity to publish papers read at the 4th Annual SATN Conference that was hosted by Central University of Technology and held in Bloemfontein in November 2011. The journal makes it possible for…

  20. Biological Damage Threshold Induced by Ultrashort Fundamental, 2nd, and 4th Harmonic Light Pulses from a Mode-Locked Nd: Glass Laser.

    DTIC Science & Technology

    1980-12-01

    BY ULTRASHORT FUNDAMENTAL, 2ND, AND 4TH HARMONIC LIGHT PULSES 00 , FROM A MODE-LOCKED Nd:GLASS LASER C Adam P. Bruckner, Ph.D. J. Michael Schurr, Ph.D...Medicine, Aerospace Medical Division, AFSC, Brooks Air Force Base, Texas. Dr. Taboada (USAFSAM/RZL) was the Laboratory Project Scientist-in-Charge. When... TABOADA , Ph.D. /AONN E. PICKERING, M.S. Project Scientist Chief, Radiation Sciences Division ROY L. DEHART Colonel, USAF, MC Commander UNCLASSIFIED S

  1. Efficient 2(nd) and 4(th) harmonic generation of a single-frequency, continuous-wave fiber amplifier.

    PubMed

    Sudmeyer, Thomas; Imai, Yutaka; Masuda, Hisashi; Eguchi, Naoya; Saito, Masaki; Kubota, Shigeo

    2008-02-04

    We demonstrate efficient cavity-enhanced second and fourth harmonic generation of an air-cooled, continuous-wave (cw), single-frequency 1064 nm fiber-amplifier system. The second harmonic generator achieves up to 88% total external conversion efficiency, generating more than 20-W power at 532 nm wavelength in a diffraction-limited beam (M(2) < 1.05). The nonlinear medium is a critically phase-matched, 20-mm long, anti-reflection (AR) coated LBO crystal operated at 25 degrees C. The fourth harmonic generator is based on an AR-coated, Czochralski-grown beta-BaB(2)O(4) (BBO) crystal optimized for low loss and high damage threshold. Up to 12.2 W of 266-nm deep-UV (DUV) output is obtained using a 6-mm long critically phase-matched BBO operated at 40 degrees C. This power level is more than two times higher than previously reported for cw 266-nm generation. The total external conversion efficiency from the fundamental at 1064 nm to the fourth harmonic at 266 nm is >50%.

  2. Fifth generation light sources

    NASA Astrophysics Data System (ADS)

    Romaniuk, Ryszard S.

    2016-12-01

    Coherent light sources are one of the most fundamental research tools in biology, technology and in other areas. Synchrotron light source consists of a few basic parts: energy source - which is an electron beam accelerator, energy converter between electron and photon beams - which is an undulator, and photon user experimental lines. Each of these parts is separately a complex system, which is currently a subject to fast technological development. Future light sources of the fifth generation are based on completely new solutions of these fundamental parts, in comparison with the sources of the previous generations. Energy source is a new generation laser - plasma accelerator with electrical field in the area of multiple GV/m. A miniature undulator is tested in the MEMS technology from new materials. Classical light beam lines, vacuum, and difficult for management and beam distribution, change their meaning in the case of availability of miniature undulators positioned immediately at or even inside the experimental stations. After an introduction concerning the light sources of the previous generations, the article shows current research efforts on the mentioned key components of the fifth generation light sources. In some cases this is a continuation and modernization of the previous technologies, in the majority it is a brave endeavour to apply completely new technologies, like laser - plasma acceleration.

  3. Organization of the Topical Meeting on Short Wavelength Coherent Radiation: Generation and Applications (4th) Held in North Falmouth, Massachusetts

    DTIC Science & Technology

    1989-03-01

    spectrometer using coherent VUV generated by four -wave 8:30 AM (Invited Paper) sum mixing has been used to study autoionization in NO and MAI The A. C...tween n = 5, 4, and 3 excited levels are observed in a 100- ps TuC13 Capillary Discharge Plasmas as Extreme Ultraviolet laser-produced heliumlike Al plasma...Interference in Four -Wave TuC28 Gain Measurement on a 18.2-nm Carbon Recombin- Mixing, K. G. H. Baldwin. Australian National U. Constructive ation Laser

  4. Second-generation surveillance for HIV/AIDS in Pakistan: results from the 4th round of Integrated Behavior and Biological Survey 2011–2012

    PubMed Central

    Emmanuel, Faran; Salim, Momina; Akhtar, Naeem; Arshad, Salwa; Reza, Tahira Ezra

    2013-01-01

    Objectives In an effort to fully analyse and understand the HIV situation and its epidemiology in Pakistan, a bilateral collaboration between the National AIDS Control Program and the Canadian International Development Agency resulted in the establishment of an effective second-generation surveillance (SGS) system for HIV/AIDS between 2004 and 2012 in accordance with the published guidelines. This paper presents findings from the 4th round of SGS. Methods A mapping exercise was initially conducted for size estimations of the key vulnerable populations: people who inject drugs (PWIDs), male sex workers (MSWs), hijra sex workers (HSWs), and female sex workers (FSWs), followed by an Integrated Behavioral and Biological Surveillance in 20 selected cities across Pakistan. Results The estimated sizes of the four key populations mapped in the 20 cities were 89 178 FSWs, 46 351 PWIDs, 23 317 HSWs and 19 119 MSWs. The HIV sero-prevalence among PWIDs was the highest among all key populations surveyed at 37.8% (CI 37.3 to 38.3) nationally, followed by a prevalence of 7.2% (CI 6.8 to 7.5) among HSWs, 3.1% (CI 2.8 to 3.4) among MSWs and 0.8% (CI 0.4 to 1.0) for FSWs. Various key risk behaviours, that is, sharing of syringes by PWIDs and inconsistent use of condoms by sex workers, were documented. Conclusions Pakistan's HIV epidemic that once was characterised primarily by transmission among PWIDs is now increasingly characterised by significant sexual transmission, and all types of sex workers (male, hijra and female) exhibit epidemiological proportions of infection. There is a need to develop concrete strategic plans for each vulnerable subpopulation, initially focusing prevention resources on those with a higher risk or vulnerability. PMID:23912818

  5. Feasibility Study of Supercritical Light Water Cooled Fast Reactors for Actinide Burning and Electric Power Production, Progress Report for Work Through September 2002, 4th Quarterly Report

    SciTech Connect

    Mac Donald, Philip Elsworth

    2002-09-01

    The use of light water at supercritical pressures as the coolant in a nuclear reactor offers the potential for considerable plant simplification and consequent capital and O&M cost reduction compared with current light water reactor (LWR) designs. Also, given the thermodynamic conditions of the coolant at the core outlet (i.e. temperature and pressure beyond the water critical point), very high thermal efficiencies of the power conversion cycle are possible (i.e. up to about 45%). Because no change of phase occurs in the core, the need for steam separators and dryers as well as for BWR-type re-circulation pumps is eliminated, which, for a given reactor power, results in a substantially shorter reactor vessel and smaller containment building than the current BWRs. Furthermore, in a direct cycle the steam generators are not needed. If no additional moderator is added to the fuel rod lattice, it is possible to attain fast neutron energy spectrum conditions in a supercritical water-cooled reactor (SCWR). This type of core can make use of either fertile or fertile-free fuel and retain a hard spectrum to effectively burn plutonium and minor actinides from LWR spent fuel while efficiently generating electricity. One can also add moderation and design a thermal spectrum SCWR. The Generation IV Roadmap effort has identified the thermal spectrum SCWR (followed by the fast spectrum SCWR) as one of the advanced concepts that should be developed for future use. Therefore, the work in this NERI project is addressing both types of SCWRs.

  6. Parametric light generation.

    PubMed

    Ebrahimzadeh, M

    2003-12-15

    Since its invention more than 40 years ago, the laser has become an indispensable optical tool, capable of transforming light from its naturally incoherent state to a highly coherent state in space and time. Yet, due to fundamental limitations, operation of the laser remains confined to restricted spectral and temporal regions. Nonlinear optics can overcome this limitation by allowing access to new spectral and temporal regimes through the exploitation of suitable dielectric materials in combination with the laser. In particular, optical parametric oscillators are versatile coherent light sources with unique flexibility that can provide optical radiation across an entire spectral range from the ultraviolet to the far-infrared and over all temporal scales from continuous wave to the ultrafast femtosecond domain.

  7. Light beam frequency comb generator

    DOEpatents

    Priatko, G.J.; Kaskey, J.A.

    1992-11-24

    A light beam frequency comb generator uses an acousto-optic modulator to generate a plurality of light beams with frequencies which are uniformly separated and possess common noise and drift characteristics. A well collimated monochromatic input light beam is passed through this modulator to produce a set of both frequency shifted and unshifted optical beams. An optical system directs one or more frequency shifted beams along a path which is parallel to the path of the input light beam such that the frequency shifted beams are made incident on the modulator proximate to but separated from the point of incidence of the input light beam. After the beam is thus returned to and passed through the modulator repeatedly, a plurality of mutually parallel beams are generated which are frequency-shifted different numbers of times and possess common noise and drift characteristics. 2 figs.

  8. Light beam frequency comb generator

    DOEpatents

    Priatko, Gordon J.; Kaskey, Jeffrey A.

    1992-01-01

    A light beam frequency comb generator uses an acousto-optic modulator to generate a plurality of light beams with frequencies which are uniformly separated and possess common noise and drift characteristics. A well collimated monochromatic input light beam is passed through this modulator to produce a set of both frequency shifted and unshifted optical beams. An optical system directs one or more frequency shifted beams along a path which is parallel to the path of the input light beam such that the frequency shifted beams are made incident on the modulator proximate to but separated from the point of incidence of the input light beam. After the beam is thus returned to and passed through the modulator repeatedly, a plurality of mutually parallel beams are generated which are frequency-shifted different numbers of times and possess common noise and drift characteristics.

  9. The 4th Thermodynamic Principle?

    SciTech Connect

    Montero Garcia, Jose de la Luz; Novoa Blanco, Jesus Francisco

    2007-04-28

    It should be emphasized that the 4th Principle above formulated is a thermodynamic principle and, at the same time, is mechanical-quantum and relativist, as it should inevitably be and its absence has been one of main the theoretical limitations of the physical theory until today.We show that the theoretical discovery of Dimensional Primitive Octet of Matter, the 4th Thermodynamic Principle, the Quantum Hexet of Matter, the Global Hexagonal Subsystem of Fundamental Constants of Energy and the Measurement or Connected Global Scale or Universal Existential Interval of the Matter is that it is possible to be arrived at a global formulation of the four 'forces' or fundamental interactions of nature. The Einstein's golden dream is possible.

  10. Method of generating chemiluminescent light

    DOEpatents

    Spurlin, Stanford R.; Yeung, Edward S.

    1986-01-01

    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.

  11. Method of generating chemiluminescent light

    DOEpatents

    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.

  12. The Leap into 4th Grade

    ERIC Educational Resources Information Center

    Anderson, Mike

    2011-01-01

    Fourth grade is a pivotal year, in which students commonly face increased academic demands. According to Anderson, teachers can help students make a smooth transition to 4th grade by introducing these new challenges in ways that are in line with 4th graders' common developmental characteristics: incredible energy and emotion, industriousness and…

  13. Microwave generated plasma light source apparatus

    SciTech Connect

    Yoshizawa, K.; Ito, H.; Kodama, H.; Komura, H.; Minowa, Y.

    1985-02-05

    A microwave generated plasma light source including a microwave generator, a microwave cavity having a light reflecting member forming at least a portion of the cavity, and a member transparent to light and opaque to microwaves disposed across an opening of the cavity opposite the feeding opening through which the microwave generator is coupled. An electrodeless discharge bulb is disposed at a position in the cavity such that the cavity operates as a resonant cavity at least when the bulb is emitting light. In the bulb is encapsulated at least one discharge light emissive substance. The bulb has a shape and is sufficiently small that the bulb acts substantially as a point light source.

  14. Performance of new generation pole light

    NASA Astrophysics Data System (ADS)

    Foo, K. C.; Karunanithi, S.; Thio, G.

    2013-06-01

    This paper describes the design and implementation of a standalone photovoltaic power supply which caters for garden lighting scheme. New Generation Pole Light (NGPL) consists of three parts which are light dependent resistor (LDR) and pyroelectric infrared (PIR) sensors, microcontroller and light emitting diode (LED) and finally, solar charging system. During the night, LED is switched on with two operating modes which are ultra-bright lighting for a predetermine period (when human presence is detected) and dim lighting. Meanwhile, LED is switched off at day time and solar charging system will recover the capacity of discharged battery. NGPL provides portable, sustainable, environmental friendly and requires minimal maintenance for outdoor lighting scheme for both urban and rural areas.

  15. 166. GENERAL VIEW DOWN 4TH AVENUE. VIEW NORTHEAST DOWN 4TH ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    166. GENERAL VIEW DOWN 4TH AVENUE. VIEW NORTHEAST DOWN 4TH AVE. FROM BUILDING 44 SHOWING, FROM LEFT TO RIGHT, BUILDING 46, 48, 55, AND 50 (PART OF ENLISTED BARRACKS COMPLEX), AND BUILDINGS 17, 16, 484, 483, 374, AND 375 (IN THE WAREHOUSE COMPLEX). - Quonset Point Naval Air Station, Roger Williams Way, North Kingstown, Washington County, RI

  16. Peer Review Handbook 4th Edition, 2015

    EPA Pesticide Factsheets

    The 4th edition of EPA's Peer Review Handbook, 2015 is the most up to date version. It was prepared for the U.S. Environmental Protection Agency by Members of the Peer Review Advisory Group under the direction of EPA’s Science and Technology Policy Council

  17. Kids & Family Reading Report™. 4th Edition

    ERIC Educational Resources Information Center

    Scholastic Inc., 2013

    2013-01-01

    This report presents the 4th Edition of Scholastic's biannual study of children's and parents' attitudes and behaviors about reading. Much has changed since the first "Kids & Family Reading Report" was issued in 2006, but literacy remains the critical skill needed for school success. Today's children are growing up in a world full of…

  18. White Light Generation in Human Saliva

    NASA Astrophysics Data System (ADS)

    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. Generation and manipulation of attosecond light pulses

    NASA Astrophysics Data System (ADS)

    Gaarde, Mette

    2006-05-01

    Attosecond pulses of light can be generated in the extremely non-linear interactions between an ultrashort, intense laser pulse and a gas of atoms, via the process of high harmonic generation [1,2]. In one approach, a number of odd harmonics of rougly equal strength are combined to form a train of sub-femtosecond pulses. If the harmonics are locked in phase to each other, the train will consist of the emission of one attosecond pulse every half cycle of the driving laser field [1,3]. It is in general not trivial to ensure that the harmonics are phase-locked as they are generated with intrinsically different phases. These phases originate in the strong field dynamics of the light-matter interaction [4].We will discuss different ways of generating and manipulating attosecond pulses via high harmonic generation. We will show how the harmonics can be phase-locked and better synchronized so as to form optimal pulse trains [3]. We will also show that it is possible to generate trains of pulses separated by a full laser cycle, by combining the driving laser field with its second harmonic [5]. The strong field continuum dynamics driven by the two-color field is very different from that of the one-color field and varies strongly with the delay between the two laser fields [6]. (1) P. M. Paul et al, Science 292, 1689 (2001).(2) M. Hentschel et al, Nature 414, 509 (2001).(3) R. Lopez-Martens et al, PRL 94, 033001 (2005).(4) P. Antoine, A. L'Huillier, and M. Lewenstein, PRL 77, 1234 (1996).(5) J. Mauritsson et al, in preparation (2006).(6) M. B. Gaarde et al, in preparation (2006).

  20. Third-generation synchrotron light sources

    SciTech Connect

    Schlachter, A.S.; Wuilleumier, F.J.

    1993-09-01

    X rays are a powerful probe of matter because they interact with electrons in atoms, molecules, and solids. They are commonly produced by relativistic electrons or positrons stored in a synchrotron. Recent advances in technology are leading to the development of a new third generation of synchrotron radiation sources that produce vacuum-ultraviolet and x-ray beams of unprecedented brightness. These new sources are characterized by a very low electron-beam emittance and by long straight sections to accommodate permanent-magnet undulators and wigglers. Several new low-energy light sources, including the Advanced Light Source, presently under construction at the Lawrence Berkeley Laboratory, and ELETTRA, presently being constructed in Trieste, will deliver the world`s brightest synchrotron radiation in the VUV and soft x-ray regions of the spectrum. Applications include atomic and molecular physics and chemistry, surface and materials science, microscopy, and life sciences.

  1. Generating A Strobed Laser Light Sheet

    NASA Technical Reports Server (NTRS)

    Leighty, Bradley D.; Franke, John M.; Rhodes, David B.; Jones, Stephen B.

    1994-01-01

    An optoelectronic system generating synchronous, strobed sheet of laser light developed for use in making visible flow of air about model helicopter rotor. Used in wind-tunnel tests to determine actual locations of vortices for comparison with locations predicted by mathematical models to validate models. Each blade tip produces vortex. By establishing successive vortex locations, researcher determines trajectory of vortex pattern. Light-sheet strobe circuits provide selection of blade positions, strobe-pulse durations, and multiple pulses per revolution for rotors having two to nine blades. To make flow visible, vaporizing propylene glycol injected upstream of model. System also provides calibrated trigger delay of strobe pulses, adjustable strobe-pulse durations, selectable number of blades, and slip-sync mode to make flow visible as though in slow motion.

  2. ACSPRI 2014 4th International Social Science Methodology Conference Report

    DTIC Science & Technology

    2015-04-01

    behaviour (Ackland, 2014). Big Data and in particular, social media data, present both methodological challenges and opportunities in empirical social ...UNCLASSIFIED UNCLASSIFIED ACSPRI 2014 4th International Social Science Methodology Conference Report Elena Mazourenko Joint...interest to the Technology Forecasting and Futures (TFF) Group of JOAD presented at the ACSPRI 4th International Social Science Methodology conference

  3. NEXT GENERATION ENERGY EFFICIENT FLUORESCENT LIGHTING PRODUCT

    SciTech Connect

    Alok Srivastava; Anant Setlur

    2003-04-01

    This is the Final Report of the Next-Generation Energy Efficient Fluorescent Lighting Products program, Department of Energy (DOE). The overall goal of this three-year program was to develop novel phosphors to improve the color rendition and efficiency of compact and linear fluorescent lamps. The prime technical approach was the development of quantum-splitting phosphor (QSP) to further increase the efficiency of conventional linear fluorescent lamps and the development of new high color rendering phosphor blends for compact fluorescent lamps (CFLs) as potential replacements for the energy-hungry and short-lived incandescent lamps in market segments that demand high color rendering light sources. We determined early in the project that the previously developed oxide QSP, SrAl{sub 12}O{sub 19}:Pr{sup 3+}, did not exhibit an quantum efficiency higher than unity under excitation by 185 nm radiation, and we therefore worked to determine the physical reasons for this observation. From our investigations we concluded that the achievement of quantum efficiency exceeding unity in SrAl{sub 12}O{sub 19}:Pr{sup 3+} was not possible due to interaction of the Pr{sup 3+} 5d level with the conduction band of the solid. The interaction which gives rise to an additional nonradiative decay path for the excitation energy is responsible for the low quantum efficiency of the phosphor. Our work has led to the development of a novel spectroscopic method for determining photoionzation threshold of luminescent centers in solids. This has resulted in further quantification of the requirements for host phosphor lattice materials to optimize quantum efficiency. Because of the low quantum efficiency of the QSP, we were unable to demonstrate a linear fluorescent lamp with overall performance exceeding that of existing mercury-based fluorescent lamps. Our work on the high color rendering CFLs has been very successful. We have demonstrated CFLs that satisfies the EnergyStar requirement with color

  4. Venezuela as an Exporter of 4th Generation Warfare Instability

    DTIC Science & Technology

    2012-12-01

    Bolivia, Cuba, Ecuador, Nicaragua, and, possibly, Argentina ; 2) Iran and Russia; and, 3) at the very least, this alliance offers material and political...destabilize bourgeois regimes. Consequently, the CCB is reported to be active in, at the least, Argentina , Bolivia, Brazil, Chile, Cuba, the Dominican...Chavista populism in Venezuela”), in La democracia defraudada, Buenos Aires, Argentina : Grito Sagrado, 2005, pp. 115-139; Julio Alblert Cirino, “La Revo

  5. Generating artificial light curves: revisited and updated

    NASA Astrophysics Data System (ADS)

    Emmanoulopoulos, D.; McHardy, I. M.; Papadakis, I. E.

    2013-08-01

    The production of artificial light curves with known statistical and variability properties is of great importance in astrophysics. Consolidating the confidence levels during cross-correlation studies, understanding the artefacts induced by sampling irregularities, establishing detection limits for future observatories are just some of the applications of simulated data sets. Currently, the widely used methodology of amplitude and phase randomization is able to produce artificial light curves which have a given underlying power spectral density (PSD) but which are strictly Gaussian distributed. This restriction is a significant limitation, since the majority of the light curves, e.g. active galactic nuclei, X-ray binaries, gamma-ray bursts, show strong deviations from Gaussianity exhibiting `burst-like' events in their light curves yielding long-tailed probability density functions (PDFs). In this study, we propose a simple method which is able to precisely reproduce light curves which match both the PSD and the PDF of either an observed light curve or a theoretical model. The PDF can be representative of either the parent distribution or the actual distribution of the observed data, depending on the study to be conducted for a given source. The final artificial light curves contain all of the statistical and variability properties of the observed source or theoretical model, i.e. the same PDF and PSD, respectively. Within the framework of Reproducible Research, the code and the illustrative example used in this paper are both made publicly available in the form of an interactive MATHEMATICA notebook.

  6. Two-mirrored galvanometer laser light sheet generator

    NASA Technical Reports Server (NTRS)

    Leighty, B. D.; Franke, J. M.; Jones, S. B.; Rhodes, D. B.

    1988-01-01

    Light sheets generated with either laser or noncoherent sources have found widespread application to flow visualization. Previous light sheet generating systems were usually dedicated to a specific viewing geometry. The technique with the most flexibility is the galvanometer mirror based laser light sheet system. A two-mirrored system was designed and developed to provide flexibility and adaptability to a wide range of applications. The design includes the capability to control the size and location of the laser light sheet in real time, to generate horizontal or vertical sheets, to sweep the sheet repeatedly through a volume, to generate multiple sheets with controllable separation and to rotate single or multiple laser light sheets. The system is capable of producing up to 12 sheets of laser light at an angular divergence of + or - 20 degrees. Maximum scan rate of any one line is 500 Hertz. This system has proven to be uniquely versatile and a patent has been applied for.

  7. VLTI: First Light for the Second Generation

    NASA Astrophysics Data System (ADS)

    Woillez, J.; Gonté, F.; Abad, J. A.; Abadie, S.; Abuter, R.; Accardo, M.; Acuña, M.; Alonso, J.; Andolfato, L.; Avila, G.; Barriga, P. J.; Beltran, J.; Berger, J.-P.; Bollados, C.; Bourget, P.; Brast, R.; Bristow, P.; Caniguante, L.; Castillo, R.; Conzelmann, R.; Cortes, A.; Delplancke, F.; Dell Valle, D.; Derie, F.; Diaz, A.; Donoso, R.; Duhoux, Ph.; Dupuy, C.; Elao, C.; Egner, S.; Fuenteseca, E.; Fernandez, R.; Gaytan, D.; Glindemann, A.; Gonzales, J.; Guisard, S.; Hagenauer, P.; Haimerl, A.; Heinz, V.; Henriquez, J. P.; van der Heyden, P.; Hubin, N.; Huerta, R.; Jochum, L.; Kirchbauer, J.-P.; Leiva, A.; Lévêque, S.; Lizon, J.-P.; Luco, F.; Mardones, P.; Mellado, A.; Mérand, A.; Osorio, J.; Ott, J.; Pallanca, L.; Pavez, M.; Pasquini, L.; Percheron, I.; Pirard, J.-F.; Phan, D. T.; Pineda, J. C.; Pino, A.; Poupar, S.; Ramírez, A.; Reinero, C.; Riquelme, M.; Romero, J.; Rivinius, Th.; Rojas, C.; Rozas, F.; Salgado, F.; Schöller, M.; Schuhler, N.; Siclari, W.; Stephan, C.; Tamblay, R.; Tapia, M.; Tristram, K.; Valdes, G.; de Wit, W.-J.; Wright, A.; Zins, G.

    2015-12-01

    The Very Large Telescope Interferometer (VLTI) stopped operation on 4 March 2015 with the objective of upgrading its infrastructure in preparation for the second generation VLTI instruments GRAVITY and MATISSE. A brief account of the eight bustling months it took our interferometer to metamorphose into its second generation, under the supervision of the VLTI Facility Project, is presented.

  8. Synchronization System for Next Generation Light Sources

    SciTech Connect

    Zavriyev, Anton

    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.

  9. Next Generation Accelerator-Based Light Sources

    SciTech Connect

    Gwyn Williams

    2005-06-26

    We discuss the physics which is driving the evolution of new sources for microscopy and spectroscopy. A new generation of sources, called energy recovery linacs or ERL’s, will be described and reviewed with particular emphasis on the examples of imaging and spectroscopic applications enabled by them.

  10. Generation of Single-Cycle Light Pulses

    SciTech Connect

    Stuart, B C; Jovanovic, I; Armstrong, J P; Pyke, B; Crane, J K; Shuttlesworth, R

    2004-02-13

    Most optical pulses, even at the 10-femtosecond timescale, consist of several oscillations of the electric field. By producing and amplifying an ultra-broadband continuum, single cycle (e 3 fs) or shorter optical pulses may be generated. This requires a very challenging pulse-compression with sub-femtosecond accuracy. Production of these single-cycle pulses will lead to new generations of experiments in the areas of coherent control of chemical excitations and reactions, 0.1-fs high-order harmonic (XUV) generation for probing of materials and fast processes, and selective 3-D micron-scale material removal and modification. We activated the first stage of a planned three-stage optical parametric amplifier (OPA) that would ultimately produce sub-3 fs pulses. Active control with a learning algorithm was implemented to optimize the continuum generated in an argon-filled capillary and to control and optimize the final compressed pulse temporal shape. A collaboration was initiated to coherently control the population of different states upon dissociation of Rb{sub 2}. Except for one final optic, a pulse compressor and diagnostics were constructed to produce and characterize pulses in the 5-fs range from the first OPA stage.

  11. Twin-Mirrored-Galvanometer Laser-Light-Sheet Generator

    NASA Technical Reports Server (NTRS)

    Rhodes, David B.; Franke, John M.; Jones, Stephen B.; Leighty, Bradley D.

    1991-01-01

    Multiple, rotating laser-light sheets generated to illuminate flows in wind tunnels. Designed and developed to provide flexibility and adaptability to wide range of applications. Design includes capability to control size and location of laser-light sheet in real time, to generate horizontal or vertical sheets, to sweep sheet repeatedly through volume, to generate multiple sheets with controllable separation, and to rotate single or multiple laser-light sheets. Includes electronic equipment and laser mounted on adjustable-height platform. Twin-mirrored galvanometer unit supported by tripod to reduce vibration. Other possible applications include use in construction industry to align beams of building. Artistic or display applications also possible.

  12. Slow light and broadband coherent phonon generation

    NASA Astrophysics Data System (ADS)

    Wang, Zheng; Rakich, Peter; Reinke, Charles; Camacho, Ryan; Davids, Paul

    2012-03-01

    Recent advance in controlling optical forces using nanostructures suggests that nanoscale optical waveguides are capable of generating coherent acoustic phonons efficiently through a combination of radiation pressure and electrostriction. We discuss the critical roles of group velocity in such processes. This photon-phonon coupling would allow an acoustic intermediary to perform on-chip optical delay with a capacity 105 greater than photonic delay lines of the same size.

  13. A twin-mirrored galvanometer laser light sheet generator

    NASA Technical Reports Server (NTRS)

    Rhodes, David B.; Franke, John M.; Jones, Stephen B.; Leighty, Bradley D.

    1988-01-01

    A galvanometer mirror-based laser light sheet system has been developed for use in the Basic Aerodynamics Research Tunnel at NASA Langley. This system generates and positions single or multiple light sheets over aeronautical research models being tested in the low speed tunnel. This report describes a twin mirrored galvanometer laser light sheet generator and shows typical light sheet arrangements in use. With this system, illumination of smoke entrained in the flow over a delta wing model reveals the vortical flow produced by the separation of the flow at the leading edge of the model. The light sheet system has proven to be very adaptable and easy to use in sizing and positioning light sheets in wind tunnel applications.

  14. Generation of Coherent Light by a Moving Medium

    NASA Astrophysics Data System (ADS)

    Svidzinsky, Anatoly A.; Li, Fu; Zhang, Xiwen

    2017-03-01

    We show that steady nonuniform motion of a medium through an optical resonator can yield light amplification at the resonator frequency. High gain can be achieved if at the generated frequency the medium refractive index is close to zero or the medium has a very strong frequency dispersion. We also discuss an analogy between light amplification by a moving medium and the generation of sound waves when gas flows along a tube with acoustically closed-open boundaries.

  15. European Code against Cancer, 4th Edition: Tobacco and cancer.

    PubMed

    Leon, Maria E; Peruga, Armando; McNeill, Ann; Kralikova, Eva; Guha, Neela; Minozzi, Silvia; Espina, Carolina; Schüz, Joachim

    2015-12-01

    Tobacco use, and in particular cigarette smoking, is the single largest preventable cause of cancer in the European Union (EU). All tobacco products contain a wide range of carcinogens. The main cancer-causing agents in tobacco smoke are polycyclic aromatic hydrocarbons, tobacco-specific N-nitrosamines, aromatic amines, aldehydes, and certain volatile organic compounds. Tobacco consumers are also exposed to nicotine, leading to tobacco addiction in many users. Cigarette smoking causes cancer in multiple organs and is the main cause of lung cancer, responsible for approximately 82% of cases. In 2012, about 313,000 new cases of lung cancer and 268,000 lung cancer deaths were reported in the EU; 28% of adults in the EU smoked tobacco, and the overall prevalence of current use of smokeless tobacco products was almost 2%. Smokeless tobacco products, a heterogeneous category, are also carcinogenic but cause a lower burden of cancer deaths than tobacco smoking. One low-nitrosamine product, snus, is associated with much lower cancer risk than other smokeless tobacco products. Smoking generates second-hand smoke (SHS), an established cause of lung cancer, and inhalation of SHS by non-smokers is still common in indoor workplaces as well as indoor public places, and more so in the homes of smokers. Several interventions have proved effective for stopping smoking; the most effective intervention is the use of a combination of pharmacotherapy and behavioural support. Scientific evidence leads to the following two recommendations for individual action on tobacco in the 4th edition of the European Code Against Cancer: (1) "Do not smoke. Do not use any form of tobacco"; (2) "Make your home smoke-free. Support smoke-free policies in your workplace".

  16. 4(th) HUPO Brain Proteome Project Workshop in Munich, Germany.

    PubMed

    Hamacher, Michael; Stephan, Christian; Palacios Bustamante, Nadine; van Hall, Andre; Marcus, Katrin; Meyer, Helmut E

    2006-01-01

    More than 70 interested colleagues attended the 4(th) Workshop of HUPO's Brain Proteome Project. The project was presented within nine talks mainly focusing on two running pilot studies as well as on data re-processing. A bioinformatics jamboree in Hinxton, UK, and the 5th Workshop taking place in Dublin next February were announced.

  17. Wavelength conversion of incoherent light by sum-frequency generation.

    PubMed

    Arahira, Shin; Murai, Hitoshi

    2014-06-02

    In this paper, we reveal that some kinds of optical nonlinearities are further enhanced when incoherent light, instead of a laser, is used as a pump light. This idea was confirmed both theoretically and experimentally in the case of sum-frequency generation (SFG) using the optical second nonlinearity. The conversion efficiency of the SFG with incoherent light pumping increased as the bandwidth of the incoherent pump light decreased, finally reaching twice the conversion efficiency of conventional second harmonic generation (SHG) by laser pumping. This method dramatically relaxes the severe requirements of phase matching in the nonlinear optical process. The conversion efficiency became less sensitive to misalignment of the wavelength of pump light and also of device operation temperature when the bandwidth of the incoherent pump light was sufficiently broad, although the improvement of the conversion efficiency had an inverse relationship with the insensitivity to the phase-matching condition. The temperature tuning range was enhanced by more than two orders of magnitude in comparison with the conventional SHG method. As an example of a promising application of this new idea, we performed the generation of quantum entangled photon-pairs using cascaded optical nonlinearities (SFG and the subsequent spontaneous parametric down conversion) in a single periodically poled LiNbO3 waveguide device, in which the incoherent light was used as the pump source for both the parametric processes. We have achieved high fidelity exceeding 99% in quantum-state tomography experiments.

  18. The POLIS interferometer for ponderomotive squeezed light generation

    NASA Astrophysics Data System (ADS)

    Calloni, Enrico; Conte, Andrea; De Laurentis, Martina; Naticchioni, Luca; Puppo, Paola; Ricci, Fulvio

    2016-07-01

    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.

  19. Light pollution generated by laser guide star at Canarian Observatories

    NASA Astrophysics Data System (ADS)

    Chueca, Sergio; Fuensalida, Jesus J.

    2004-11-01

    A new generation of instrument using a launching laser is been developed to correct the atmospheric image blurring and to establish optical communication with space. Then, light pollution generated by laser will be a serious operational problem in next years. This laser could affect astronomical works of adjacent telescopes when the laser lay across the field of view of the observing telescope, this is a kind of light pollution. This could be avoided with an adequate operational politic to detect possible interference between the laser and the astronomical telescopes. In this paper is analysed the mathematical probability of a cross-event happen.

  20. 4th International Plant Biomechanics Conference Proceedings (Abstracts)

    SciTech Connect

    Frank W. Telewski; Lothar H. Koehler; Frank W. Ewers

    2003-07-20

    The 4th International Plant Biomechanics Conference facilitated an interdisciplinary exchange between scientists, engineers, and educators addressing the major questions encountered in the field of Plant Biomechanics. Subjects covered by the conference include: Evolution; Ecology; Mechanoreception; Cell Walls; Genetic Modification; Applied Biomechanics of Whole Plants, Plant Products, Fibers & Composites; Fluid Dynamics; Wood & Trees; Fracture Mechanics; Xylem Pressure & Water Transport; Modeling; and Introducing Plant Biomechanics in Secondary School Education.

  1. Summary of the 4th Nordic Symposium on Digital Pathology

    PubMed Central

    Lundström, Claes; Waltersson, Marie; Persson, Anders; Treanor, Darren

    2017-01-01

    The Nordic symposium on digital pathology (NDP) was created to promote knowledge exchange across stakeholders in health care, industry, and academia. In 2016, the 4th NDP installment took place in Linköping, Sweden, promoting development and collaboration in digital pathology for the benefit of routine care advances. This article summarizes the symposium, gathering 170 attendees from 13 countries. This summary also contains results from a survey on integrated diagnostics aspects, in particular radiology-pathology collaboration. PMID:28382222

  2. Fifth-Generation Free-Electron Laser Light Sources

    SciTech Connect

    Pellegrini, Claudio

    2011-03-02

    During the past few years, the Linac Coherent Light Source (LCLS) and the Free-Electron Laser in Hamburg (FLASH) have demonstrated the outstanding capability of free-electron lasers (FELs) as sources of coherent radiation in the soft and hard x-ray region. The high intensity, tens of GW, short pulses (few to less than 100 femtoseconds, and the unique transverse coherence properties are opening a new window to study the structure and dynamics of atomic and molecular systems. The LCLS, FLASH, and the other FELs now under construction are only the beginning of the development of these light sources. The next generations will reach new levels of performance: terawatt, atto-second, ultra-small line-width, high repetition rate, full longitudinal and transverse coherence. These future developments and the R&D needed to successfully build and operate the next generation of FEL light sources will be discussed.

  3. Electrically controlled nonlinear generation of light with plasmonics.

    PubMed

    Cai, Wenshan; Vasudev, Alok P; Brongersma, Mark L

    2011-09-23

    Plasmonics provides a route to develop ultracompact optical devices on a chip by using extreme light concentration and the ability to perform simultaneous electrical and optical functions. These properties also make plasmonics an ideal candidate for dynamically controlling nonlinear optical interactions at the nanoscale. We demonstrate electrically tunable harmonic generation of light from a plasmonic nanocavity filled with a nonlinear medium. The metals that define the cavity also serve as electrodes that can generate high direct current electric fields across the nonlinear material. A fundamental wave at 1.56 micrometers was frequency doubled and modulated in intensity by applying a moderate external voltage to the electrodes, yielding a voltage-dependent nonlinear generation with a normalized magnitude of ~7% per volt.

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

    NASA Astrophysics Data System (ADS)

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

    2013-02-01

    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.

  5. Digital phantoms generated by spectral and spatial light modulators

    PubMed Central

    Chon, Bonghwan; Tokumasu, Fuyuki; Lee, Ji Youn; Allen, David W.; Rice, Joseph P.; Hwang, Jeeseong

    2015-01-01

    Abstract. A hyperspectral image projector (HIP) based on liquid crystal on silicon spatial light modulators is explained and demonstrated to generate data cubes. The HIP-constructed data cubes are three-dimensional images of the spatial distribution of spectrally resolved abundances of intracellular light-absorbing oxyhemoglobin molecules in single erythrocytes. Spectrally and spatially resolved image data indistinguishable from the real scene may be used as standard data cubes, so-called digital phantoms, to calibrate image sensors and validate image analysis algorithms for their measurement quality, performance consistency, and interlaboratory comparisons for quantitative biomedical imaging applications. PMID:26502383

  6. Digital phantoms generated by spectral and spatial light modulators

    NASA Astrophysics Data System (ADS)

    Chon, Bonghwan; Tokumasu, Fuyuki; Lee, Ji Youn; Allen, David W.; Rice, Joseph P.; Hwang, Jeeseong

    2015-12-01

    A hyperspectral image projector (HIP) based on liquid crystal on silicon spatial light modulators is explained and demonstrated to generate data cubes. The HIP-constructed data cubes are three-dimensional images of the spatial distribution of spectrally resolved abundances of intracellular light-absorbing oxyhemoglobin molecules in single erythrocytes. Spectrally and spatially resolved image data indistinguishable from the real scene may be used as standard data cubes, so-called digital phantoms, to calibrate image sensors and validate image analysis algorithms for their measurement quality, performance consistency, and interlaboratory comparisons for quantitative biomedical imaging applications.

  7. Control of Laser High-Harmonic Generation with Counterpropagating Light

    NASA Astrophysics Data System (ADS)

    Voronov, S. L.; Kohl, I.; Madsen, J. B.; Simmons, J.; Terry, N.; Titensor, J.; Wang, Q.; Peatross, J.

    2001-09-01

    Relatively weak counterpropagating light is shown to disrupt the emission of laser high-harmonic generation. Harmonic orders ranging from the teens to the low thirties produced by a 30-femtosecond pulse in a narrow argon jet are ``shut down'' with a contrast as high as 2 orders of magnitude by a chirped 1-picosecond counterpropagating laser pulse (60 times less intense). Alternatively, under poor phase-matching conditions, the counterpropagating light boosts harmonic production by similar contrast through quasiphase matching where out-of-phase emission is suppressed.

  8. Report of the 4th European Zebrafish Principal Investigator Meeting.

    PubMed

    Lopes, Susana S; Distel, Martin; Linker, Claudia; Fior, Rita; Monteiro, Rui; Bianco, Isaac H; Portugues, Ruben; Strähle, Uwe; Saúde, Leonor

    2016-12-01

    The European Zebrafish Principal Investigator Meeting (EZPM) is an ideal forum for group leaders using this fantastic animal model not only to discuss science but also to strengthen their interactions, to push forward technological advances, and to define guidelines for the use of this fish in research. The city of Lisbon (Portugal) was voted by the European group leaders to be the setting for the 4th EZPM, and the organizing committee, composed by Leonor Saúde (iMM Lisboa, PT), Susana Lopes (CEDOC, PT), Michael Orger (Champalimaud Foundation, PT), Rui Oliveira (ISPA, PT), and António Jacinto (CEDOC, PT), was very enthusiastic to organize a productive event. The 4th EZPM took place from March 15 to 19 at Pavilhão do Conhecimento, a Science Museum and Educational Center winner of The Great Prize FAD of Arquitecture 1999 and The Society for Environmental Graphic Design Award 2011. Over 5 days, 135 group leaders (89 men and 46 women) coming from 19 different European countries and also from the United States, Turkey, Israel, Chile, and Singapore presented and discussed their recent research achievements. In addition to the scientific oral and poster presentations, the group leaders gathered in very lively community sessions on morphants versus mutants (chaired by Didier Stainier, Max Planck Institute for Heart and Lung Research, DE), funding issues (chaired by Uwe Strahle, KIT-ITG, DE), and gender equality (chaired by Corinne Houart, KCL, United Kingdom). One of the highlights of the 4th EZPM was the guided visit to Oceanário de Lisboa, an international award-winning place that celebrates life with a stunning display of living aquatic creatures.

  9. 4TH Marine Division Operation Plan Number 49-44

    DTIC Science & Technology

    1944-12-26

    I / i i -4- A. o. o o o 3 4-’ 4TH MARINE DIVISION 54 OPERATION PLAN NO. 49-44 DECLASSIFIED IAW CLIASSIFICATION $4...INTO ENEMY HANDS. LUISrAR! UNCLASS0FIDo .-O UNCLASSIFIED ri LL!n .. I . 155 - - o.- sr Report Documentation Page Form ApprovedOMB No. 0704-0188 Public...the remainder of O-1 within Z, repared or further OPN PLAN 49-44 - 1 - O1 :?’:¢ . ... ~·~:~ I I - I --" , I %,"_’,: A I 1-W_ , - I I ---. -

  10. Simplified Generation of High-Angular-Momentum Light Beams

    NASA Technical Reports Server (NTRS)

    Savchenkov, Anatoliy; Maleki, Lute; Matsko, Andrey; Strekalov, Dmitry; Grudinin, Ivan

    2007-01-01

    A simplified method of generating a beam of light having a relatively high value of angular momentum (see figure) involves the use of a compact apparatus consisting mainly of a laser, a whispering- gallery-mode (WGM) resonator, and optical fibers. The method also can be used to generate a Bessel beam. ( Bessel beam denotes a member of a class of non-diffracting beams, so named because their amplitudes are proportional to Bessel functions of the radii from their central axes. High-order Bessel beams can have high values of angular momentum.) High-angular-momentum light beams are used in some applications in biology and nanotechnology, wherein they are known for their ability to apply torque to make microscopic objects rotate. High-angular-momentum light beams could also be used to increase bandwidths of fiber-optic communication systems. The present simplified method of generating a high-angular-momentum light beam was conceived as an alternative to prior such methods, which are complicated and require optical setups that include, variously, holograms, modulating Fabry-Perot cavities, or special microstructures. The present simplified method exploits a combination of the complex structure of the electromagnetic field inside a WGM resonator, total internal reflection in the WGM resonator, and the electromagnetic modes supported by an optical fiber. The optical fiber used to extract light from the WGM resonator is made of fused quartz. The output end of this fiber is polished flat and perpendicular to the fiber axis. The input end of this fiber is cut on a slant and placed very close to the WGM resonator at an appropriate position and orientation. To excite the resonant whispering- gallery modes, light is introduced into the WGM resonator via another optical fiber that is part of a pigtailed fiber-optic coupler. Light extracted from the WGM resonator is transformed into a high-angular- momentum beam inside the extraction optical fiber and this beam is emitted from the

  11. Electron Beam Collimation for the Next Generation Light Source

    SciTech Connect

    Steier, C.; Emma, P.; Nishimura, H.; Papadopoulos, C.; Sannibale, F.

    2013-05-20

    The Next Generation Light Source will deliver high (MHz) repetition rate electron beams to an array of free electron lasers. Because of the significant average current in such a facility, effective beam collimation is extremely important to minimize radiation damage to undulators, prevent quenches of superconducting cavities, limit dose rates outside of the accelerator tunnel and prevent equipment damage. This paper describes the early conceptual design of a collimation system, as well as initial results of simulations to test its effectiveness.

  12. Rate of Missing Socioeconomic Factors in the 4th KNHANES.

    PubMed

    Park, Hyun Ah

    2012-11-01

    This study is to assess how missing values in socioeconomic status (SES) variables were handled in the Korean Journal of Family Medicine (KJFM) article using the Korea National Health and Nutrition Examination Survey (KNHANES) data and to estimate the rate of missing SES variables from the 4th KNHANES. We searched all original articles published in the KJFM from 2007 to 2011 and identified those that used KNHANES as their primary source of data. None of the 11 articles which presented KNHANES SES variables took into account of omitions in the analysis. The estimated rate of missing data on education, household income, marital status, and occupation data of the 4th KNHANES was 0.3 (0.05)%, 2.7 (0.2)%, 0.5 (0.1)%, and 9.4 (0.9)%, respectively. When all four variables were used simultaneously, the rates increased to 11.8 (0.9)%. Respondents with missing household income tended to be older (P < 0.001), less educated (P < 0.001), and more likely to be unemployed (P < 0.001), and widowed (P < 0.001). A similar relationship was shown for missing occupation data. Omissions in SES variables in KNHANES were related to certain characteristics of study participants. Researchers using KNHANES data should keep in mind the possible bias which can be introduced by missing SES values.

  13. Flashing light signaling circuit in sponges: endogenous light generation after tissue ablation in Suberites domuncula.

    PubMed

    Wiens, Matthias; Wang, Xiaohong; Unger, Andreas; Schröder, Heinz C; Grebenjuk, Vladislav A; Pisignano, Dario; Jochum, Klaus P; Müller, Werner E G

    2010-12-15

    The skeleton of siliceous sponges (phylum Porifera: classes Demospongiae and Hexactinellida), composed of tightly interacting spicules that assemble to a genetically fixed scaffold, is formed of bio-silica. This inorganic framework with the quality of quartz glass has been shown to operate as light waveguide in vitro and very likely has a similar function in vivo. Furthermore, the molecular toolkit for endogenous light generation (luciferase) and light/photon harvesting (cryptochrome) has been identified in the demosponge Suberites domuncula. These three components of a light signaling system, spicules-luciferase-cryptochrome, are concentrated in the surface layers (cortex) of the poriferan body. Specimens from which this cortex has been removed/ablated do not emit light. However, with regeneration and reconstitution of the cortex the animals re-gain the capacity to flash light. This newly discovered characteristic of sponges to generate light prompted us to investigate the genetic basis for the endogenous light signaling system. As a potential transcription factor involved in the expression of luciferase and cryptochrome, a SOX-related protein has been identified. In dark-adapted animals or in tissue from below the cortex region, the medulla, no gene or protein expression of SOX-related protein, luciferase, and cryptochrome could be detected. However, during the regeneration of the cortex, a stage-specific expression pattern was recorded: SOX-related protein > luciferase > cryptochrome. We conclude that a flashing light signaling circuit exists, which might control the retinoic acid-induced differentiation of stem cells into pulsating and contracting sponge cells, that is, pinacocytes and myocytes.

  14. Light Emitting Diode-Generated Blue Light Modulates Fibrosis Characteristics: Fibroblast Proliferation, Migration Speed, and Reactive Oxygen Species Generation

    PubMed Central

    Mamalis, Andrew; Garcha, Manveer; Jagdeo, Jared

    2016-01-01

    Background and Objective Blue light is part of the visible light spectrum that does not generate harmful DNA adducts associated with skin cancer and photoaging, and may represent a safer therapeutic modality for treatment of keloid scars and other fibrotic skin diseases. Our laboratory previously demonstrated that light-emitting diode (LED) red and infrared light inhibits proliferation of skin fibroblasts. Moreover, different wavelengths of light can produce different biological effects. Furthermore, the effects of LED blue light (LED-BL) on human skin fibroblasts are not well characterized. This study investigated the effects of LED-BL on human skin fibroblast proliferation, viability, migration speed, and reactive oxygen-species (ROS) generation. Methods and Materials Irradiation of adult human skin fibroblasts using commercially-available LED-BL panels was performed in vitro, and modulation of proliferation and viability was quantified using the trypan blue dye exclusion assay, migratory speed was assessed using time-lapse video microscopy, and intracellular ROS generation was measured using the dihydrorhodamine flow cytometry assay. Statistical differences between groups were determined by ANOVA and Student s t-test. Results Human skin fibroblasts treated with LED-BL fluences of 5, 30, 45, and 80 J/cm2 demonstrated statistically significant dose-dependent decreases in relative proliferation of 8.4%, 29.1%, 33.8%, 51.7%, and 55.1%, respectively, compared to temperature and environment matched bench control plates, respectively. LED-BL fluences of 5, 30, 45 and 80 J/cm2 decreased fibroblast migration speed to 95 ± 7.0% (p = 0.64), 81.3 ± 5.5% (p = 0.021), 48.5 ± 2.7% (p < 0.0001), and 32.3 ± 1.9% (p < 0.0001), respectively, relative to matched controls. LED fluences of 5, 10, 30, and 80 J/cm2 resulted in statistically significant increases in reactive oxygen species of 110.4%, 116.6%, 127.5%, and 130%, respectively, relative to bench controls. Conclusion At

  15. Special Issue: 4th International Workshop on Space Radiation (IWSRR)

    NASA Technical Reports Server (NTRS)

    Cucinotta, Francis A.

    2007-01-01

    This special issue of the journal "Radiation and Environmental Biophysics" contains 20 peer-reviewed papers contributed by leading space radiation researcher's world-wide attending the 4th IWSRR. Manuscripts cover a broad range of topics ranging from radiation environments and transport in shielding and planetary surfaces to new results in understanding the biological effects of protons and high-charge and energy (HZE) nuclei on the risk of cancer, and degenerative diseases such as central nervous system effects, heart disease, and cataracts. The issue provides a snapshot of the state-of-the-art of the research in this field, demonstrating both the important results gathered in the past few years with experiments at accelerators, and the need for more research to quantify the risk and develop countermeasures.

  16. 76 FR 37649 - Safety Zone; Northern California Annual Fireworks Events, July 4th Fireworks Display

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-28

    ... SECURITY Coast Guard 33 CFR Part 165 Safety Zone; Northern California Annual Fireworks Events, July 4th Fireworks Display AGENCY: Coast Guard, DHS. ACTION: Notice of enforcement of regulation. SUMMARY: The Coast Guard will enforce safety zone for the annual July 4th Fireworks Display (Tahoe City 4th of...

  17. Nonlocality-driven supercontinuum white light generation in plasmonic nanostructures

    PubMed Central

    Krasavin, A. V.; Ginzburg, P.; Wurtz, G. A.; Zayats, A. V.

    2016-01-01

    Structured plasmonic metals are widely employed for achieving nonlinear functionalities at the nanoscale due to their ability to confine and enhance electromagnetic fields and strong, inherent nonlinearity. Optical nonlinearities in centrosymmetric metals are dominated by conduction electron dynamics, which at the nanoscale can be significantly affected by the nonlocal effects. Here we show that nonlocal corrections, being usually small in the linear optical response, define nonlinear properties of plasmonic nanostructures. Using a full non-perturbative time-domain hydrodynamic description of electron plasma under femtosecond excitation, we numerically investigate harmonic generation in metallic Archimedean nanospirals, revealing the interplay between geometric and nonlocal effects. The quantum pressure term in the nonlinear hydrodynamic model results in the emergence of fractional nonlinear harmonics leading to broadband coherent white-light generation. The described effects present a novel class of nonlinear phenomena in metallic nanostructures determined by nonlocality of the electron response. PMID:27157982

  18. Nonlocality-driven supercontinuum white light generation in plasmonic nanostructures.

    PubMed

    Krasavin, A V; Ginzburg, P; Wurtz, G A; Zayats, A V

    2016-05-09

    Structured plasmonic metals are widely employed for achieving nonlinear functionalities at the nanoscale due to their ability to confine and enhance electromagnetic fields and strong, inherent nonlinearity. Optical nonlinearities in centrosymmetric metals are dominated by conduction electron dynamics, which at the nanoscale can be significantly affected by the nonlocal effects. Here we show that nonlocal corrections, being usually small in the linear optical response, define nonlinear properties of plasmonic nanostructures. Using a full non-perturbative time-domain hydrodynamic description of electron plasma under femtosecond excitation, we numerically investigate harmonic generation in metallic Archimedean nanospirals, revealing the interplay between geometric and nonlocal effects. The quantum pressure term in the nonlinear hydrodynamic model results in the emergence of fractional nonlinear harmonics leading to broadband coherent white-light generation. The described effects present a novel class of nonlinear phenomena in metallic nanostructures determined by nonlocality of the electron response.

  19. Nonlocality-driven supercontinuum white light generation in plasmonic nanostructures

    NASA Astrophysics Data System (ADS)

    Krasavin, A. V.; Ginzburg, P.; Wurtz, G. A.; Zayats, A. V.

    2016-05-01

    Structured plasmonic metals are widely employed for achieving nonlinear functionalities at the nanoscale due to their ability to confine and enhance electromagnetic fields and strong, inherent nonlinearity. Optical nonlinearities in centrosymmetric metals are dominated by conduction electron dynamics, which at the nanoscale can be significantly affected by the nonlocal effects. Here we show that nonlocal corrections, being usually small in the linear optical response, define nonlinear properties of plasmonic nanostructures. Using a full non-perturbative time-domain hydrodynamic description of electron plasma under femtosecond excitation, we numerically investigate harmonic generation in metallic Archimedean nanospirals, revealing the interplay between geometric and nonlocal effects. The quantum pressure term in the nonlinear hydrodynamic model results in the emergence of fractional nonlinear harmonics leading to broadband coherent white-light generation. The described effects present a novel class of nonlinear phenomena in metallic nanostructures determined by nonlocality of the electron response.

  20. Spectrum of second-harmonic radiation generated from incoherent light

    SciTech Connect

    Stabinis, A.; Pyragaite, V.; Tamosauskas, G.; Piskarskas, A.

    2011-10-15

    We report on the development of the theory of second-harmonic generation by an incoherent pump with broad angular and frequency spectra. We show that spatial as well as temporal walk-off effects in a nonlinear crystal result in angular dispersion of the second-harmonic radiation. We demonstrate that the acceptance angle in second-harmonic generation by incoherent light is caused by the width of the pump angular spectrum and the resulting angular dispersion of second-harmonic radiation but does not depend on crystal length. In this case the frequency spectrum of second-harmonic radiation is determined by its angular dispersion and the pump angular spectrum. The theory is supported by an experiment in which a LiIO{sub 3} crystal was pumped by a tungsten halogen lamp.

  1. 77 FR 56637 - FirstLight Hydro Generating Company; Notice of Authorization for Continued Project Operation

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-09-13

    .... 2662-000] FirstLight Hydro Generating Company; Notice of Authorization for Continued Project Operation On August 30, 2007, the FirstLight Hydro Generating Company, licensee for the Scotland Hydroelectric... annual license for Project No. 2662 [[Page 56638

  2. Managing haemophilia for life: 4th Haemophilia Global Summit.

    PubMed

    Astermark, J; Dolan, G; Hilberg, T; Jiménez-Yuste, V; Laffan, M; Lassila, R; Lobet, S; Martinoli, C; Perno, C-F

    2014-07-01

    The 4th Haemophilia Global Summit was held in Potsdam, Germany, in September 2013 and brought together an international faculty of haemophilia experts and delegates from multidisciplinary backgrounds. The programme was designed by an independent Scientific Steering Committee of haemophilia experts and explored global perspectives in haemophilia care, discussing practical approaches to the optimal management of haemophilia now and in the future. The topics outlined in this supplement were selected by the Scientific Steering Committee for their relevance and potential to influence haemophilia care globally. In this supplement from the meeting, Jan Astermark reviews current understanding of risk factors for the development of inhibitory antibodies and discusses whether this risk can be modulated and minimized. Factors key to the improvement of joint health in people with haemophilia are explored, with Carlo Martinoli and Víctor Jiménez-Yuste discussing the utility of ultrasound for the early detection of haemophilic arthropathy. Other aspects of care necessary for the prevention and management of joint disease in people with haemophilia are outlined by Thomas Hilberg and Sébastian Lobet, who highlight the therapeutic benefits of physiotherapy and sports therapy. Riitta Lassila and Carlo-Federico Perno describe current knowledge surrounding the risk of transmission of infectious agents via clotting factor concentrates. Finally, different types of extended half-life technology are evaluated by Mike Laffan, with a focus on the practicalities and challenges associated with these products.

  3. The 4th Concept Detector for the ILC

    NASA Astrophysics Data System (ADS)

    Mazzacane, A.

    2010-05-01

    The 4th Concept Detector is designed for high precision measurements of Physics processes accessible at ILC. It consists of four basic subsystems: a pixel vertex detector for high precision vertex definitions, impact parameter tagging and near-beam occupancy reduction; a cluster-counting low-mass drift chamber for robust pattern recognition with over 100 three-dimensional space-points each with about 55 μm resolution, 3.5% specific ionization measurement; a high precision dual-readout fiber calorimeter, complemented with an EM dual-readout crystal calorimeter, both with time-history readout, for the energy measurement of hadrons, jets, electrons, photons, missing momentum, and the tagging of muons; and, an iron-free dual-solenoid to return the flux and provide a second field region for the inverse direction bending of muons in a gas volume to achieve high acceptance and good muon momentum resolution. All four subsystems separately achieve the important scientific goal to be 2-to-10 times better than the already excellent LEP detectors, Aleph, Delphi, L3, and Opal. All four sub-detector will be described along with their performance and Physics capabilities obtained with full simulation studies.

  4. European Code against Cancer 4th Edition: Diet and cancer.

    PubMed

    Norat, Teresa; Scoccianti, Chiara; Boutron-Ruault, Marie-Christine; Anderson, Annie; Berrino, Franco; Cecchini, Michele; Espina, Carolina; Key, Tim; Leitzmann, Michael; Powers, Hilary; Wiseman, Martin; Romieu, Isabelle

    2015-12-01

    Lifestyle factors, including diet, have long been recognised as potentially important determinants of cancer risk. In addition to the significant role diet plays in affecting body fatness, a risk factor for several cancers, experimental studies have indicated that diet may influence the cancer process in several ways. Prospective studies have shown that dietary patterns characterised by higher intakes of fruits, vegetables, and whole-grain foods, and lower intakes of red and processed meats and salt, are related to reduced risks of death and cancer, and that a healthy diet can improve overall survival after diagnosis of breast and colorectal cancers. There is evidence that high intakes of fruit and vegetables may reduce the risk of cancers of the aerodigestive tract, and the evidence that dietary fibre protects against colorectal cancer is convincing. Red and processed meats increase the risk of colorectal cancer. Diets rich in high-calorie foods, such as fatty and sugary foods, may lead to increased calorie intake, thereby promoting obesity and leading to an increased risk of cancer. There is some evidence that sugary drinks are related to an increased risk of pancreatic cancer. Taking this evidence into account, the 4th edition of the European Code against Cancer recommends that people have a healthy diet to reduce their risk of cancer: they should eat plenty of whole grains, pulses, vegetables and fruits; limit high-calorie foods (foods high in sugar or fat); avoid sugary drinks and processed meat; and limit red meat and foods high in salt.

  5. A Next Generation Light Source Facility at LBNL

    SciTech Connect

    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.

    2011-03-23

    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, highrepetition- 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.

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

    NASA Technical Reports Server (NTRS)

    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.

  7. Blue light generation using periodically poled nonlinear crystals

    NASA Astrophysics Data System (ADS)

    Khademian, Ali; Shiner, David

    2013-05-01

    We have studied blue light generation using SHG of IR light. We have used single pass waveguides and bulk crystals with buildup cavities. The nonlinear crystals used were periodically poled Lithium Niobate (LN) and Potassium Titanyl Phosphate (KTP). Each of these approaches had limitations with regards to the maximum power handling and the stability of operation. Currently we are working on a different crystal in a new buildup cavity to circumvent some of the previous difficulties resulting from photorefractive damage and excessive heating due to blue absorption. Our initial measurements show that Lithium Tantalite (LT) has higher photorefractive threshold and much lower blue absorption (2% vs 15% for 20 mm crystal length). The new buildup cavity incorporates a more convenient commercial piezo mirror translator for feedback control. The buildup cavity can be operated with a minimum of 6 V as opposed to the 1000 V previously. We are exploring the use of a single DSP (digital signal processor) to perform all the locking and electronic control functions of the cavity. We are studying the coupling and propagation properties of the IR beams more carefully to minimize cavity and coupling losses, particularly due to front wave distortion caused by mirrors and lenses used in the setup. To optimize our cavity and to make the best and simplest choice of optical elements possible, different commercial (off the shelf) lenses and mirrors have been evaluated experimentally in our setup. This work is supported by NSF grant PHY-1068868.

  8. White light generation from Dy3+ doped tellurite glass

    NASA Astrophysics Data System (ADS)

    Damak, Kamel; Yousef, El Sayed; Rüssel, Christian; Maâlej, Ramzi

    2014-02-01

    This paper reports on the spectral results of Dy3+ (1.0 mol%) ions-doped TeO2-ZnO-PbO-PbF2-Na2O (TZPPN) glass. Raman spectrum measurements, differential thermal analysis (DTA) profiles of this rare-earth ion-doped glass were carried out. From the DTA thermogram, glass transition (Tg), crystallization (Tc) and melting (Tm) temperatures were evaluated. Direct and indirect optical band gaps were calculated based on the glasses UV absorption spectra. From the absorption spectra, Judd-Ofelt (J-O) intensity parameters, Ωk, were calculated. Using J-O intensity parameters, several radiative properties such as spontaneous transition probabilities (AR), radiative branching ratios (βR) and radiative lifetimes (τR) were determined for the excitation level 4F9/2. From the emission spectra, a strong yellow emission at 574 nm (4F9/2→6H13/2) was observed and it also showed a combination of blue and red emission bands for this glass. The stimulated emission cross-section σ(λp) was also evaluated for the 4F9/2→6HJ (J=11/2, 13/2, and 15/2) transitions. This study indicates that 1 mol% Dy2O3-doped tellurite glass can be considered for white light generation with the excitation of blue light (454 nm).

  9. PREFACE: 4th International Hadron Physics Conference (TROIA'14)

    NASA Astrophysics Data System (ADS)

    Dağ, Hüseyin; Erkol, Güray; Küçükarslan, Ayşe; Özpineci, Altuğ

    2014-11-01

    The 4th International Conference on Hadron Physics, TROIA'14, was held at Canakkale, Turkey on 1-5 July 2014. Ozyegin University, Middle East Technical University, Canakkale Onsekiz Mart University, Turkish Atomic Energy Authority and HadronPhysics2 Consortium sponsored the conference. It aimed at bringing together the experts and the young scientists working on experimental and theoretical hadron physics. About 50 participants from 10 countries attended the conference. The topics covered included: . Chiral Perturbation Theory . QCD Sum Rules . Effective Field Theory . Exotic Hadrons . Hadron Properties from Lattice QCD . Experimental Results and Future Perspectives . Hadronic Distribution Amplitudes The conference presentations were organized such that the morning sessions contained invited talks and afternoon sessions were devoted to contributed talks. The speakers of the invited talks were: C. Alexandrou, A. Gal, L. Tolos, J.R. Pelaez and M. Schindler. We had also guest speakers D. A. Demir and T. Senger. The conference venue was a resort hotel around Canakkale. As a social program, a guided full-day excursion to the excavation site of the ancient Troia town and Assos was organized. We believe that this conference provided a medium for young scientists and experts in the field to effectively communicate and share ideas. We would like to express our sincere thanks to supporting agencies and to all participants for their contributions and stimulating discussions. We are also grateful to the Scientific Secretary, Bora Işıldak, and all other members of the Organizing Committee for their patience and efforts. 30.10.2014 The Editors

  10. Light absorption properties of laboratory generated tar ball particles

    NASA Astrophysics Data System (ADS)

    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

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

    NASA Astrophysics Data System (ADS)

    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

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

    NASA Astrophysics Data System (ADS)

    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

  13. The ALS — A third-generation light source

    NASA Astrophysics Data System (ADS)

    Robinson, A. L.; Schlachter, A. S.

    1990-05-01

    The Advanced Light Source, a third-generation national synchrotron-radiation facility now under construction at the Lawrence Berkeley Laboratory, is scheduled to begin serving qualified users across a broad spectrum of research areas in April 1993. Based on a low-emittance electron storage ring optimized to operate at 1.5 GeV, the ALS will have 11 long straight sections available for insertion devices (undulators and wigglers). Undulators will generate high-brightness soft-X-ray and ultraviolet (XUV) radiation; wigglers will extend the spectrum generated into the hard-X-ray region, but at a lower brightness. Up to 48 bending-magnet ports will also be available. Engineering design has begun on a complement of three undulators with periods of 8.0, 5.0, and 3.9 cm. Among them, the photon-energy range from 5.4 eV to 2.5 keV will be covered when the first, third, and fifth undulator harmonics are used. Also being designed is a wiggler with a critical energy of 3.1 keV. Undulator beam lines will be based on high-resolution spherical-grating monochromators. A Call for Proposals has been issued for those who wish to participate in the design, development, commissioning, and operation of the initial complement of the ALS experimental facilities (insertion devices, beam lines, and experimental stations) as members of a participating research team. The deadline for receipt of proposals was August 15, 1989. Proposals are expected to reflect the Letters of Interest received from potential participating research teams (PRTs) during the previous year.

  14. European Code against Cancer, 4th Edition: Cancer screening.

    PubMed

    Armaroli, Paola; Villain, Patricia; Suonio, Eero; Almonte, Maribel; Anttila, Ahti; Atkin, Wendy S; Dean, Peter B; de Koning, Harry J; Dillner, Lena; Herrero, Rolando; Kuipers, Ernst J; Lansdorp-Vogelaar, Iris; Minozzi, Silvia; Paci, Eugenio; Regula, Jaroslaw; Törnberg, Sven; Segnan, Nereo

    2015-12-01

    In order to update the previous version of the European Code against Cancer and formulate evidence-based recommendations, a systematic search of the literature was performed according to the methodology agreed by the Code Working Groups. Based on the review, the 4th edition of the European Code against Cancer recommends: "Take part in organized cancer screening programmes for: Bowel cancer (men and women); Breast cancer (women); Cervical cancer (women)." Organized screening programs are preferable because they provide better conditions to ensure that the Guidelines for Quality Assurance in Screening are followed in order to achieve the greatest benefit with the least harm. Screening is recommended only for those cancers where a demonstrated life-saving effect substantially outweighs the potential harm of examining very large numbers of people who may otherwise never have, or suffer from, these cancers, and when an adequate quality of the screening is achieved. EU citizens are recommended to participate in cancer screening each time an invitation from the national or regional screening program is received and after having read the information materials provided and carefully considered the potential benefits and harms of screening. Screening programs in the European Union vary with respect to the age groups invited and to the interval between invitations, depending on each country's cancer burden, local resources, and the type of screening test used For colorectal cancer, most programs in the EU invite men and women starting at the age of 50-60 years, and from then on every 2 years if the screening test is the guaiac-based fecal occult blood test or fecal immunochemical test, or every 10 years or more if the screening test is flexible sigmoidoscopy or total colonoscopy. Most programs continue sending invitations to screening up to the age of 70-75 years. For breast cancer, most programs in the EU invite women starting at the age of 50 years, and not before the age

  15. Generating Coherent Phonons and Spin Excitations with Ultrafast Light Pulses

    NASA Astrophysics Data System (ADS)

    Merlin, Roberto

    2006-03-01

    Recent work on the generation of coherent low-lying excitations by ultrafast laser pulses will be reviewed, emphasizing the microscopic mechanisms of light-matter interaction. The topics covered include long-lived phonons in ZnO [C. Aku-Leh, J. Zhao, R. Merlin, J. Men'endez and M. Cardona, Phys. Rev.B 71, 205211 (2005)], squeezed magnons [J. Zhao, A. V. Bragas, D. J. Lockwood and R. Merlin, Phys. Rev. Lett. 93, 107203 (2004)], spin- and charge-density fluctuations [J. M. Bao et al., Phys. Rev. Lett. 92, 236601 (2004)] and cyclotron resonance [J. K. Wahlstrand, D. M. Wang, P. Jacobs, J. M. Bao, R. Merlin, K. W. West and L. N. Pfeiffer, AIP Conference Proceedings 772 (2005), p. 1313] in GaAs quantum wells. In addition, unpublished results on surface -avoiding phonons in GaAs-AlAs superlattices [M. Trigo et al., unpublished] and magnons in ferromagnetic Ga1-xMnxAs [D. M. Wang et al., unpublished] will be discussed. It will also be shown that frequencies can be measured using pump-probe techniques with a precision comparable to that of Brillouin scattering. It is now widely accepted that stimulated Raman scattering (SRS) is (often but not always) the mechanism responsible for the coherent coupling. Results will be presented showing that SRS is described by two separate tensors, one of which accounts for the excitation-induced modulation of the susceptibility, and the other one for the dependence of the amplitude of the oscillation on the light intensity [T. E. Stevens, J. Kuhl and R. Merlin, Phys. Rev. B 65, 144304 (2002)]. These tensors have the same real component, associated with impulsive coherent generation, but different imaginary parts. If the imaginary term dominates, that is, for strongly absorbing substances, the mechanism for two-band processes becomes displacive in nature, as in the DECP (displacive excitation of coherent phonons) model. It will be argued that DECP is not a separate mechanism, but a particular case of SRS. In the final part of the talk, an

  16. Monolithic LED arrays, next generation smart lighting sources

    NASA Astrophysics Data System (ADS)

    Lagrange, Alexandre; Bono, Hubert; Templier, François

    2016-03-01

    LED have become the main light sources of the future as they open the path for intelligent use of light in time, intensity and color. In many usages, strong energy economy is done by adjusting these properties. The smart lighting has three dimensions, energy efficiency brought by GaN blue emitting LEDs, integration of electronics, sensors, microprocessors in the lighting system and development of new functionalities and services provided by the light. Monolithic LED arrays allow two major innovations, the spatial control of light emission and the adjustment of the electrical properties of the source.

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

    SciTech Connect

    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.

  18. Physics Computing '92: Proceedings of the 4th International Conference

    NASA Astrophysics Data System (ADS)

    de Groot, Robert A.; Nadrchal, Jaroslav

    1993-04-01

    The Table of Contents for the book is as follows: * Preface * INVITED PAPERS * Ab Initio Theoretical Approaches to the Structural, Electronic and Vibrational Properties of Small Clusters and Fullerenes: The State of the Art * Neural Multigrid Methods for Gauge Theories and Other Disordered Systems * Multicanonical Monte Carlo Simulations * On the Use of the Symbolic Language Maple in Physics and Chemistry: Several Examples * Nonequilibrium Phase Transitions in Catalysis and Population Models * Computer Algebra, Symmetry Analysis and Integrability of Nonlinear Evolution Equations * The Path-Integral Quantum Simulation of Hydrogen in Metals * Digital Optical Computing: A New Approach of Systolic Arrays Based on Coherence Modulation of Light and Integrated Optics Technology * Molecular Dynamics Simulations of Granular Materials * Numerical Implementation of a K.A.M. Algorithm * Quasi-Monte Carlo, Quasi-Random Numbers and Quasi-Error Estimates * What Can We Learn from QMC Simulations * Physics of Fluctuating Membranes * Plato, Apollonius, and Klein: Playing with Spheres * Steady States in Nonequilibrium Lattice Systems * CONVODE: A REDUCE Package for Differential Equations * Chaos in Coupled Rotators * Symplectic Numerical Methods for Hamiltonian Problems * Computer Simulations of Surfactant Self Assembly * High-dimensional and Very Large Cellular Automata for Immunological Shape Space * A Review of the Lattice Boltzmann Method * Electronic Structure of Solids in the Self-interaction Corrected Local-spin-density Approximation * Dedicated Computers for Lattice Gauge Theory Simulations * Physics Education: A Survey of Problems and Possible Solutions * Parallel Computing and Electronic-Structure Theory * High Precision Simulation Techniques for Lattice Field Theory * CONTRIBUTED PAPERS * Case Study of Microscale Hydrodynamics Using Molecular Dynamics and Lattice Gas Methods * Computer Modelling of the Structural and Electronic Properties of the Supported Metal Catalysis

  19. Eshbach's handbook of engineering fundamentals /4th edition/

    NASA Astrophysics Data System (ADS)

    Tapley, Byron D.; Poston, Thurman R.

    Formulas, constants, design parameters for basic devices, and other information of practical use to engineers and scientists is compiled in handbook form. Sections are devoted to mathematical and physical units and standards; mathematics; the mechanics of rigid and deformable bodies; incompressible fluids; aeronautics; astronautics; automatic control; computer science; engineering thermodynamics and heat transfer; electromagnetics and circuits; electronics; light, radiation, and acoustics; chemistry; engineering economics; and the properties of materials.

  20. The school nutrition program's role in weight management of 4th grade elementary students

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We are attempting to uncover the school nutrition program's role in weight management of 4th grade elementary students. Data was collected within a time frame for the food frequency questionnaire (FFQ) set at two months at the WT Cheney Elementary School and South Wood Elementary for 4th grade stud...

  1. 76 FR 37650 - Safety Zone; 4th of July Festival Berkeley Marina Fireworks Display Berkeley, CA

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-28

    ... SECURITY Coast Guard 33 CFR Part 165 RIN 1625-AA00 Safety Zone; 4th of July Festival Berkeley Marina Fireworks Display Berkeley, CA AGENCY: Coast Guard, DHS. ACTION: Temporary final rule. SUMMARY: The Coast... Berkeley Pier, Berkeley, CA in support of the 4th of July Festival Berkeley Marina Fireworks...

  2. The Effects of Cooperative Learning Strategies on Vocabulary Skills of 4th Grade Students

    ERIC Educational Resources Information Center

    Bilen, Didem; Tavil, Zekiye Müge

    2015-01-01

    This study was carried out to investigate the effects of cooperative learning strategies on the vocabulary skills of 4th grade students. The study was also designed to ascertain the attitudes of the students in the experimental group towards cooperative learning. Out of 96 4th grade students enrolled in the private school where the study took…

  3. 75 FR 35649 - Safety Zone; Northern California Annual Fireworks Events, July 4th Fireworks Display

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-23

    ... SECURITY Coast Guard 33 CFR Part 165 Safety Zone; Northern California Annual Fireworks Events, July 4th Fireworks Display AGENCY: Coast Guard, DHS. ACTION: Notice of enforcement of regulation. SUMMARY: The Coast Guard will enforce the Tahoe City 4th of July Fireworks Display safety zone, from 9 a.m. through 10...

  4. Science Content Courses: Workshop in Food Chemistry for 4th Grade School Teachers

    ERIC Educational Resources Information Center

    Chaiyapechara, S.; Dong, F. M.

    2004-01-01

    A science content course in food chemistry was offered as a 4-day summer workshop from 1999 to 2001 to 4th grade school teachers in the Seattle School District. The objectives of the workshop were to increase the teachers' knowledge of food science, to perform simple experiments that could be used in the 4th grade classroom, and to help the…

  5. Suppression of white light generation (supercontinuum) in biological media: a pilot study using human salivary proteins

    NASA Astrophysics Data System (ADS)

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

    2007-02-01

    Propagation of ultrashort pulses of intense, infrared light through transparent medium gives rise to a visually spectacular phenomenon known as supercontinuum (white light) generation wherein the spectrum of transmitted light is very considerably broader than that of the incident light. We have studied the propagation of ultrafast (<45 fs) pulses of intense infrared light through biological media (water, and water doped with salivary proteins) which reveal that white light generation is severely suppressed in the presence of a major salivary protein, α-amylase.

  6. Next Generation Lighting Technologies (LBNL Summer Lecture Series)

    ScienceCinema

    Siminovittch, Micheal

    2016-07-12

    For the past several years, Michael Siminovittch, a researcher in the Environmental Energy Technologies Division of Lawrence Berkeley National Laboratory, has worked to package efficient lighting in an easy-to-use and good-looking lamp. His immensely popular "Berkeley Lamp" has redefined how America lights its offices.

  7. The 1992 4th NASA SERC Symposium on VLSI Design

    NASA Technical Reports Server (NTRS)

    Whitaker, Sterling R.

    1992-01-01

    Papers from the fourth annual NASA Symposium on VLSI Design, co-sponsored by the IEEE, are presented. Each year this symposium is organized by the NASA Space Engineering Research Center (SERC) at the University of Idaho and is held in conjunction with a quarterly meeting of the NASA Data System Technology Working Group (DSTWG). One task of the DSTWG is to develop new electronic technologies that will meet next generation electronic data system needs. The symposium provides insights into developments in VLSI and digital systems which can be used to increase data systems performance. The NASA SERC is proud to offer, at its fourth symposium on VLSI design, presentations by an outstanding set of individuals from national laboratories, the electronics industry, and universities. These speakers share insights into next generation advances that will serve as a basis for future VLSI design.

  8. Light generation via quantum interaction of electrons with periodic nanostructures

    NASA Astrophysics Data System (ADS)

    Tsesses, Shai; Bartal, Guy; Kaminer, Ido

    2017-01-01

    The Smith-Purcell effect is a hallmark of light-matter interactions in periodic structures, resulting in light emission with distinct spectral and angular distribution. We find yet undiscovered effects in Smith-Purcell radiation that arise due to the quantum nature of light and matter, through an approach based on exact energy and momentum conservation. The effects include emission cutoff, convergence of emission orders, and a possible second photoemission process, appearing predominantly in structures with nanoscale periodicities (a few tens of nanometers or less), accessible by recent nanofabrication advances. We further present ways to manipulate the effects by varying the geometry or by accounting for a refractive index. Our derivation emphasizes the fundamental relation between Smith-Purcell radiation and Čerenkov radiation, and paves the way to alternative kinds of light sources wherein nonrelativistic electrons create Smith-Purcell radiation in nanoscale, on-chip devices. Finally, the path towards experimental realizations of these effects is discussed.

  9. A Feasibility Study on Generation of Acoustic Waves Utilizing Evanescent Light

    NASA Astrophysics Data System (ADS)

    Matsuya, I.; Matozaki, K.; Kosugi, A.; Ihara, I.

    2014-06-01

    A new approach of generating acoustic waves utilizing evanescent light is presented. The evanescent light is a non-propagating electromagnetic wave that exhibits exponential decay with distance from the surface at which the total internal reflection of light is formed. In this research, the evanescent light during total internal reflection at prism surface is utilized for generating acoustic waves in aluminium and the feasibility for ultrasonic measurements is discussed. Pulsed Nd:YAG laser with 0.36 J/cm2 power density is used and the incident angle during the total internal reflection is arranged to be 69.0° for generating the evanescent light. It has been demonstrated that the amplitude of the acoustic waves by means of evanescent light is about 1/14 as large as the one generated by the conventional pulsed laser. This reveals the possibility of using a laser ultrasonic technique with near-field optics.

  10. 4th-International Symposium on Ultrafast Surface Science - Final Report

    SciTech Connect

    Hrvoje Petek

    2005-01-26

    The 4-th International Symposium on Ultrafast Surface Dynamics (UDS4) was held at the Telluride Summer Research Center on June 22-27, 2003. The International Organizing Committee consisting of Hrvoje Petek (USA), Xiaoyang Zhu (USA), Pedro Echenique (Spain) and Maki Kawai (Japan) brought together a total of 51 participants 16 of whom were from Europe, 10 from Japan, and 25 from the USA. The focus of the conference was on ultrafast electron or light induced processes at well-defined surfaces. Ultrafast surface dynamics concerns the transfer of charge and energy at solid surfaces on the femtosecond time scale. These processes govern rates of fundamental steps in surface reactions, interfacial electron transfer in molecular electronics, and relaxation in spin transport. Recent developments in femtosecond laser technology make it possible to measure by a variety of nonlinear optical techniques directly in the time domain the microscopic rates underlying these interfacial processes. Parallel progress in scanning probe microscopy makes it possible at a single molecular level to perform the vibrational and electronic spectroscopy measurements, to induce reactions with tunneling electrons, and to observe their outcome. There is no doubt that successful development in the field of ultrafast surface dynamics will contribute to many important disciplines.

  11. Micro-Structured Materials for Generation of Coherent Light and Optical Signal Processing

    DTIC Science & Technology

    2008-12-22

    within a laser linewidth of 1 GHz (matched to the doppler broadened bandwidth of the sodium layer) to provide enough return light to the wavefront...AND SUBTITLE Micro-Structured Materials for Generation of Coherent Light And Optical Signal Processing 5a. CONTRACT NUMBER 5b. GRANT NUMBER...2008 3. TITLE OF PROPOSAL: Micro-Structured Matenals for Generation of Coherent Light And Optical Signal Processing 4. LIST OF MANUSCRIPTS

  12. Generation of an incident focused light pulse in FDTD.

    PubMed

    Capoğlu, Ilker R; Taflove, Allen; Backman, Vadim

    2008-11-10

    A straightforward procedure is described for accurately creating an incident focused light pulse in the 3-D finite-difference time-domain (FDTD) electromagnetic simulation of the image space of an aplanatic converging lens. In this procedure, the focused light pulse is approximated by a finite sum of plane waves, and each plane wave is introduced into the FDTD simulation grid using the total-field/scattered-field (TF/SF) approach. The accuracy of our results is demonstrated by comparison with exact theoretical formulas.

  13. 4th Annual DOE-ERSP PI Meeting: Abstracts

    SciTech Connect

    Hazen, Terry C.

    2009-03-01

    This contains abstracts from the 2009 Annual Environmental Remediation Sciences Program (ERSP) Principal Investigators (PI) Meeting. The ERSP seeks to advance fundamental science to understand, predict, and mitigate the impacts of environmental contamination from past nuclear weapons production and provide a scientific basis for the long-term stewardship of nuclear waste disposal. These ambitious goals cannot be achieved by any one project alone. Therefore, ERSP funds a combination of research programs at the DOE national laboratories, individual projects at universities and federal agencies, and large long(er)-term field site research. Integration of these activities to advance the ERSP goals is a constant challenge, but made significantly simpler by bringing together all funded ERSP researchers once a year to discuss the very latest research results. It is at these meetings where new ideas and/or scientific advancements in support of ERSP goals can be discussed and openly debated among all PIs in the program. The ERSP thrives, in part, on the new ideas, concepts, scientific connections, and collaborations generated as a result of these meetings. The annual PI Meeting is very much a working meeting with three major goals: (1) to provide opportunities for scientific interaction among the ERSP scientists, a critical element for the program; (2) to provide the ERSP program staff with an opportunity to evaluate the progress of each program and project; and (3) to showcase the ERSP to interested parties within DOE and within other federal agencies In addition to program managers from within OBER, there will be representatives from other offices within DOE and other federal agencies in attandance at the meeting.

  14. 18. DETAILED OFFSHORE VIEW OF 4TH TEE, LOOKING NORTHWEST, SHOWING ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    18. DETAILED OFFSHORE VIEW OF 4TH TEE, LOOKING NORTHWEST, SHOWING TRANSITION FROM WOOD BENTS TO CONCRETE BENTS - Huntington Beach Municipal Pier, Pacific Coast Highway at Main Street, Huntington Beach, Orange County, CA

  15. Qualification of the 4th stage propulsor of the Brazilian launcher. SLV: A new sounding rocket

    NASA Astrophysics Data System (ADS)

    Boscov, Jayme; Toyama, Wilson Katsumi

    1989-06-01

    The development of the Satellite Launcher Vehicle (SLV) is presented. In particular, the attention is focused on the acquisition of the propulsion parameters of the 4th stage propulsor. The device feasibility analysis is considered. The system consists of a two staged sounding rocket. Its second stage contains the SVL, which can be launched by the 4th stage propulsor to a height range of about 50 to 60 km.

  16. White-light generation control with crossing beams of femtosecond laser pulses.

    PubMed

    Kolomenskii, A A; Strohaber, J; Kaya, N; Kaya, G; Sokolov, A V; Schuessler, H A

    2016-01-11

    We investigated the variations in generated white-light when crossing two femtosecond laser beams in a Kerr medium. By changing the relative delay of two interacting intense femtosecond laser pulses, we show that white-light generation can be enhanced or suppressed. With a decrease of the relative delay an enhancement of the white-light output was observed, which at even smaller delays was reverted to a suppression of white-light generation. Under choosen conditions, the level of suppression resulted in a white-light output lower than the initial level corresponding to large delays, when the pulses do not overlap in time. The enhancement of the white-light generation takes place in the pulse that is lagging. We found that the effect of the interaction of the beams depends on their relative orientation of polarization and increases when the polarizations are changed from perpendicular to parallel. The observed effects are explained by noting that at intermediate delays, the perturbations introduced in the path of the lagging beam lead to a shortening of the length of filament formation and enhancement of the white-light generation, whereas at small delays the stronger interaction and mutual rescattering reduces the intensity in the central part of the beams, suppressing filamentation and white-light generation.

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

    SciTech Connect

    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.

  18. Generation of isolated asymmetric umbilics in light's polarization

    NASA Astrophysics Data System (ADS)

    Galvez, Enrique J.; Rojec, Brett L.; Kumar, Vijay; Viswanathan, Nirmal K.

    2014-03-01

    Polarization-singularity C points, a form of line singularities, are the vectorial counterparts of the optical vortices of spatial modes and fundamental optical features of polarization-spatial modes. Their generation in tailored beams has been limited to so-called "lemon" and "star" C points that contain symmetric dislocations in state-of-polarization patterns. In this Rapid Communication we present the theory and laboratory measurements of two complementary methods to generate isolated asymmetric C points in tailored beams, of which symmetric lemon and star patterns are limiting cases; and we report on the generation of so-called "monstar" patterns, an asymmetric C point with characteristics of both lemons and stars.

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

    SciTech Connect

    Thomas, D. M.; Allen, J. E.

    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.

  20. The Generation of Lighting in the Solar Nebula

    NASA Technical Reports Server (NTRS)

    Cuzzi, Jeffrey; Desch, S. J.; DeVincenzi, Donald (Technical Monitor)

    1998-01-01

    The process that melted and formed the chondrules, mm-sized glassy beads within meteorites, has not been conclusively identified. Origin by lightning in the solar nebula is consistent with many features of chondrules, but no viable model of lightning has yet been advanced. We present a model demonstrating how lightning could be generated in the solar nebula which differs from previous models in three important aspects. First, we identify a new', powerful charging mechanism that is based on the differences in contact potentials between particles of different composition, a form of triboelectric charging. In the presence of fine silicate grains and fine iron metal grains, large silicate particles (the chondrules) can acquire charges of +10(exp 5) e. Second, we assume that the chondrule precursor particles are selectively concentrated in clumps 1 - 100 km in size by the turbulent concentration mechanism described by Cuzzi et al. (1996). The concentration of these highly charged particles into clumps, in a background of negatively charged metal grains, is what generates the strong electric fields. Third, we make refinements in the estimates of the breakdown electric field and the ionization rate. We calculate that electric fields large enough to trigger breakdown easily could have existed over regions large enough (approx. 100km) to generate very large discharges of electrical energy (approx. 10(exp 16)erg). The discharges would have been sufficiently energetic and frequent to have formed the chondrules. We place constraints on the generation of lightning and conclude that it could not be generated if the abundance of Al-26 in chondrules was as high as the level in the CAls. This conclusion is consistent with isotopic analyses of chondrules. This possibly implies that Al-26 was non-uniformly distributed in the solar nebula or that the chondrules formed several Myr after the CAIs.

  1. Hydroxyl radical generation by a light-dependent Fenton reaction.

    PubMed

    Van der Zee, J; Krootjes, B B; Chignell, C F; Dubbelman, T M; Van Steveninck, J

    1993-02-01

    Illumination of Fe3+, with light of a wavelength varying from 250 to 450 nm, in the presence of the iron chelators ethylenediamine N,N,N',N'-tetraacetic acid (EDTA), ethyleneglycol-bis-(beta-aminoethylether)N,N,N',N'-tetraacet ic acid (EGTA), diethylenetriamine-N,N,N',N',N'-pentaacetic acid (DTPA), or citrate resulted in the reduction of Fe3+ to Fe2+. Fe2+ formation was measured by the formation of its complex with bathophenanthroline disulfonic acid. In all cases Fe2+ formation was completely dependent on the presence of the iron chelator and on the wavelength used for illumination. A correlation was found between the absorption spectrum of the iron-chelator complex and the amount of Fe3+ reduced, suggesting that the absorption of light induced an electron transfer from the chelator to the iron ion. Exposure to oxygen, either during or after illumination, resulted in degradation of the chelator molecule. Illumination of the Fe(3+)-chelator complexes in the presence of H2O2 resulted in the formation of hydroxyl radicals, which could be determined by the formation of the 5,5-dimethyl-1-pyrroline N-oxide (DMPO)-hydroxyl radical adduct, using electron spin resonance spectroscopy. Formation of the spin adduct was inhibited by addition of catalase, mannitol, ethanol, or formate, whereas superoxide dismutase had no effect.

  2. Generation of blue light by sum-frequency generation of a spectrally combined broad-area diode laser array.

    PubMed

    Zhu, Zhanda; Jiang, Menghua; Yu, Haoyang; Hui, Yongling; Lei, Hong; Li, Qiang

    2016-10-15

    We present the first demonstration of a spectrally beam combined diode laser array with subsequent sum-frequency generation (SFG). The combined beam of the diode laser array with 19 emitters has the same beam quality as a single emitter, and the wavelength of each emitter is different. The blue light is generated by sum-frequency mixing of pairs of emitters in the diode laser array. About 93 mW of blue light power is produced using a PPLN crystal. Compared with the SFG of two emitters, this approach can increase the number of lasers participating in nonlinear frequency conversion. Thus, it can enhance the available power.

  3. Systematically frameshifting by deletion of every 4th or 4th and 5th nucleotides during mitochondrial transcription: RNA self-hybridization regulates delRNA expression.

    PubMed

    Seligmann, Hervé

    2016-01-01

    In mitochondria, secondary structures punctuate post-transcriptional RNA processing. Recently described transcripts match the human mitogenome after systematic deletions of every 4th, respectively every 4th and 5th nucleotides, called delRNAs. Here I explore predicted stem-loop hairpin formation by delRNAs, and their associations with delRNA transcription and detected peptides matching their translation. Despite missing 25, respectively 40% of the nucleotides in the original sequence, del-transformed sequences form significantly more secondary structures than corresponding randomly shuffled sequences, indicating biological function, independently of, and in combination with, previously detected delRNA and thereof translated peptides. Self-hybridization decreases delRNA abundances, indicating downregulation. Systematic deletions of the human mitogenome reveal new, unsuspected coding and structural informations.

  4. Support for the 4th Pan-American Congress on Plants and Bioenergy

    SciTech Connect

    Carpita, Nicholas C.

    2016-01-25

    Intellectual Merit: Following the success of the first three Pan-American Congresses on Plants and BioEnergy held biennially, the 4th congress will be held at the University of Guelph, Canada June 4-7, 2014. We aim to continue a tradition of showcasing major advances in energy crop improvement yet keep in perspective the realities of the economic drivers and pressures that govern the translation of scientific success into a commercial success. The congress is endorsed by the American Society of Plant Biologists and the Canadian Society of Plant Biologists. The program will cover a range of disciplines, including algal and plant systems for bioenergy, plant genetics and genomics, gene discovery for improvement of bioenergy production and quality, regulatory mechanisms of synthesis and degradation, strategies for 3rd generation biofuel production and the promise of synthetic biology in production of biofuels and bio-based products, cropping systems and productivity for biomass production, and mitigation of environmental impacts of bioenergy production. Broader Impacts: We are requesting support to generate stipends for domestic and permanent-resident students, post-doctorals, and pre-tenured faculty members to attend and benefit from the outstanding program. The stipends will be limited to registration and on-site lodging costs, with partial support for travel in instances of great need. So that as great a number can benefit as possible, airfare costs will be provided for only applicants with great need. ASPB has endorsed this meeting and will assist in advertising and promoting the meeting. ASPB has a long-standing commitment to increase participation and advance the careers in plant biology of women, minorities and underrepresented scientists, and they will assist us in identifying worthy candidates.

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

    EPA Pesticide Factsheets

    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.

  6. Generation of high-power laser light with Gigahertz splitting.

    PubMed

    Unks, B E; Proite, N A; Yavuz, D D

    2007-08-01

    We demonstrate the generation of two high-power laser beams whose frequencies are separated by the ground state hyperfine transition frequency in (87)Rb. The system uses a single master diode laser appropriately shifted by high frequency acousto-optic modulators and amplified by semiconductor tapered amplifiers. This produces two 1 W laser beams with a frequency spacing of 6.834 GHz and a relative frequency stability of 1 Hz. We discuss possible applications of this apparatus, including electromagnetically induced transparency-like effects and ultrafast qubit rotations.

  7. Modular approach to achieving the next-generation X-ray light source

    NASA Astrophysics Data System (ADS)

    Biedron, S. G.; Milton, S. V.; Freund, H. P.

    2001-12-01

    A modular approach to the next-generation light source is described. The "modules" include photocathode, radio-frequency, electron guns and their associated drive-laser systems, linear accelerators, bunch-compression systems, seed laser systems, planar undulators, two-undulator harmonic generation schemes, high-gain harmonic generation systems, nonlinear higher harmonics, and wavelength shifting. These modules will be helpful in distributing the next-generation light source to many more laboratories than the current single-pass, high-gain free-electron laser designs permit, due to both monetary and/or physical space constraints.

  8. Hydrogen storage and generation using light metal hydrides

    SciTech Connect

    Lynch, F.; Mork, B.J.; Wilkes, J.S.

    1998-07-01

    The storage of hydrogen for use in fuel cells employed as portable electric power sources is important. For many applications pressurized gas or cryogenic liquid storage is not acceptable from weight or safety standpoints. This is particularly true for moderate power systems in the 50--200 watt range. A potentially attractive technology for providing hydrogen for moderately sized fuel cell-based electric power supplies is chemical hydrides. In general, chemical hydrides are materials that store hydrogen that may be released by chemical reactions. The authors report here the use of light metal hydrides, such as lithium aluminum tetrahydride and trilithium aluminum hexahydride to store hydrogen in a very dense form; about four times the density of liquid hydrogen. The hydrogen can be released by reaction with simple chemical reagents, such as water or ammonia, at approximately atmospheric pressure and at modest temperatures. The reaction rate may be controlled to provide hydrogen at a rate appropriate to that needed by a fuel cell operating at the power levels mentioned above. Usually hydrogen is the sole gaseous product, along with several solid products.

  9. Optical pumping experiments on next-generation light sources

    NASA Astrophysics Data System (ADS)

    Moon, Stephen J.; Fournier, Kevin B.; Scott, H.; Chung, H.-K.; Lee, R. W.

    2004-11-01

    Laser-based plasma spectroscopic techniques have been used with great success to determine the line shapes of atomic transitions in plasmas, study the population kinetics of atomic systems embedded in plasmas, and look at the redistribution of radiation. However, the possibilities for optical lasers end for plasmas with ne > 1022 cm-3 as light propagation is severely altered by the plasma. The construction of the Tesla Test Facility (TTF) at DESY (Deutsche Elektronen-Synchrotron), a short pulse tunable free electron laser in the vacuum-ultraviolet and soft X-ray regime (VUV FEL), based on the SASE (self amplified spontaneous emission) process, will provide a major advance in the capability for dense plasma-related research. This source will provide 1013 photons in a 200 fs duration pulse that is tunable from ~6 nm to 100 nm. Since an VUV FEL will not have the limitation associated with optical lasers the entire field of high density plasmas kinetics in laser produced plasma will then be available to study with the tunable source. Thus, one will be able to use this and other FEL x-ray sources to pump individual transitions creating enhanced population in the excited states that can be easily monitored. We show two case studies illuminating different aspects of plasma spectroscopy.

  10. Optical Pumping Experiments on Next Generation Light Sources

    SciTech Connect

    Moon, S J; Fournier, K B; Scott, H; Chung, H K; Lee, R W

    2004-07-29

    Laser-based plasma spectroscopic techniques have been used with great success to determine the line shapes of atomic transitions in plasmas, study the population kinetics of atomic systems embedded in plasmas, and look at the redistribution of radiation. However, the possibilities for optical lasers end for plasmas with n{sub e}>10{sup 22}cm{sup -3} as light propagation is severely altered by the plasma. The construction of the Tesla Test Facility(TTF) at DESY(Deutsche Elektronen-Synchrotron), a short pulse tunable free electron laser in the vacuum-ultraviolet and soft X-ray regime (VUV FEL), based on the SASE(self amplified spontaneous emission) process, will provide a major advance in the capability for dense plasma-related research. This source will provide 10{sup 13} photons in a 200 fs duration pulse that is tunable from {approx} 6nm to 100nm. Since an VUV FEL will not have the limitation associated with optical lasers the entire field of high density plasmas kinetics in laser produced plasma will then be available to study with tunable source. Thus, one will be able to use this and other FEL x-ray sources to pump individual transitions creating enhanced population in the excited states that can easily be monitored. We show two case studies illuminating different aspects of plasma spectroscopy.

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

    SciTech Connect

    Manginell, Ronald P.; Sillerud, Colin Halliday; Hopkins, Matthew M.; Yee, Benjamin Tong; Moorman, Matthew W.; Schwindt, Peter; Anderson, John Moses; Pfeifer, Nathaniel Bryant

    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.

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

    PubMed

    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.

  13. High-order harmonic generation enhanced by XUV light

    SciTech Connect

    Buth, Christian; Kohler, Markus C.; Ullrich, Joachim; Keitel, Christoph H.

    2012-03-19

    The combination of high-order harmonic generation (HHG) with resonant XUV excitation of a core electron into the transient valence vacancy that is created in the course of the HHG process is investigated theoretically. In this setup, the first electron performs a HHG three-step process, whereas the second electron Rabi flops between the core and the valence vacancy. The modified HHG spectrum due to recombination with the valence and the core is determined and analyzed for krypton on the 3d {yields} 4p resonance in the ion. We assume an 800 nm laser with an intensity of about 10{sup 14} Wcm{sup 2} and XUV radiation from the Free Electron Laser in Hamburg (FLASH) with an intensity in the range 10{sup 13}-10{sup 16} Wcm{sup 2}. Our prediction opens perspectives for nonlinear XUV physics, attosecond x rays, and HHG-based spectroscopy involving core orbitals.

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

    PubMed Central

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

    2016-01-01

    Objective 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. Methods 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. Results 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. Conclusions 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. PMID:27896210

  15. Light-generated oligonucleotide arrays for rapid DNA sequence analysis.

    PubMed Central

    Pease, A C; Solas, D; Sullivan, E J; Cronin, M T; Holmes, C P; Fodor, S P

    1994-01-01

    In many areas of molecular biology there is a need to rapidly extract and analyze genetic information; however, current technologies for DNA sequence analysis are slow and labor intensive. We report here how modern photolithographic techniques can be used to facilitate sequence analysis by generating miniaturized arrays of densely packed oligonucleotide probes. These probe arrays, or DNA chips, can then be applied to parallel DNA hybridization analysis, directly yielding sequence information. In a preliminary experiment, a 1.28 x 1.28 cm array of 256 different octanucleotides was produced in 16 chemical reaction cycles, requiring 4 hr to complete. The hybridization pattern of fluorescently labeled oligonucleotide targets was then detected by epifluorescence microscopy. The fluorescence signals from complementary probes were 5-35 times stronger than those with single or double base-pair hybridization mismatches, demonstrating specificity in the identification of complementary sequences. This method should prove to be a powerful tool for rapid investigations in human genetics and diagnostics, pathogen detection, and DNA molecular recognition. Images PMID:8197176

  16. Porting LEON3FT/GRLIB to 4th Generation Flash-Based Devices

    NASA Astrophysics Data System (ADS)

    Andersson, Jan; Habinc, Sandi; Prinetto, Paolo; Trotta, Pascal

    2015-09-01

    Cobham Gaisler develops the LEON3FT SPARC V8 fault-tolerant microprocessor that is available both as IP cores part of an IP library (GRLIB) that allows users to design their own custom system-on-chip (SoC) designs, and also as part of ready-made designs and devices. Cobham Gaisler has recently added support for Microsemi IGLOO2, and experimental support for Microsemi radiation-tolerant RTG4, devices to GRLIB.

  17. Towards 4th generation biomaterials: a covalent hybrid polymer-ormoglass architecture

    NASA Astrophysics Data System (ADS)

    Sachot, N.; Mateos-Timoneda, M. A.; Planell, J. A.; Velders, A. H.; Lewandowska, M.; Engel, E.; Castaño, O.

    2015-09-01

    Hybrid materials are being extensively investigated with the aim of mimicking the ECM microenvironment to develop effective solutions for bone tissue engineering. However, the common drawbacks of a hybrid material are the lack of interactions between the scaffold's constituents and the masking of its bioactive phase. Conventional hybrids often degrade in a non-homogeneous manner and the biological response is far from optimal. We have developed a novel material with strong interactions between constituents. The bioactive phase is directly exposed on its surface mimicking the structure of the ECM of bone. Here, polylactic acid electrospun fibers have been successfully and reproducibly coated with a bioactive organically modified glass (ormoglass, Si-Ca-P2 system) covalently. In comparison with the pure polymeric mats, the fibers obtained showed improved hydrophilicity and mechanical properties, bioactive ion release, exhibited a nanoroughness and enabled good cell adhesion and spreading after just one day of culture (rMSCs and rEPCs). The fibers were coated with different ormoglass compositions to tailor their surface properties (roughness, stiffness, and morphology) by modifying the experimental parameters. Knowing that cells modulate their behavior according to the exposed physical and chemical signals, the development of this instructive material is a valuable advance in the design of functional regenerative biomaterials.Hybrid materials are being extensively investigated with the aim of mimicking the ECM microenvironment to develop effective solutions for bone tissue engineering. However, the common drawbacks of a hybrid material are the lack of interactions between the scaffold's constituents and the masking of its bioactive phase. Conventional hybrids often degrade in a non-homogeneous manner and the biological response is far from optimal. We have developed a novel material with strong interactions between constituents. The bioactive phase is directly exposed on its surface mimicking the structure of the ECM of bone. Here, polylactic acid electrospun fibers have been successfully and reproducibly coated with a bioactive organically modified glass (ormoglass, Si-Ca-P2 system) covalently. In comparison with the pure polymeric mats, the fibers obtained showed improved hydrophilicity and mechanical properties, bioactive ion release, exhibited a nanoroughness and enabled good cell adhesion and spreading after just one day of culture (rMSCs and rEPCs). The fibers were coated with different ormoglass compositions to tailor their surface properties (roughness, stiffness, and morphology) by modifying the experimental parameters. Knowing that cells modulate their behavior according to the exposed physical and chemical signals, the development of this instructive material is a valuable advance in the design of functional regenerative biomaterials. Electronic supplementary information (ESI) available. See DOI: 10.1039/c5nr04275e

  18. FIB–SEM tomography of 4th generation PWA 1497 superalloy

    SciTech Connect

    Ziętara, Maciej Kruk, Adam Gruszczyński, Adam Czyrska-Filemonowicz, Aleksandra

    2014-01-15

    The effect of creep deformation on the microstructure of the PWA 1497 single crystal Ni-base superalloy developed for turbine blade applications was investigated. The aim of the present study was to characterize quantitatively a superalloy microstructure and subsequent development of rafted γ′ precipitates in the PWA 1497 during creep deformation at 982 °C and 248 MPa up to rupture. The PWA1497 microstructure was characterized by scanning electron microscopy and FIB–SEM electron tomography. The 3D reconstruction of the PWA1497 microstructure is presented and discussed. - Highlights: • The microstructure of PWA1497 superalloy was examined using FIB–SEM tomography. • In case of modern single crystal superalloys, measurements of A{sub A} are adequate for V{sub V}. • During creep the γ channel width increases from 65 to 193 nm for ruptured specimen. • Tomography is a useful technique for quantitative studies of material microstructure.

  19. Highly efficient second harmonic generation of a light carrying orbital angular momentum in an external cavity.

    PubMed

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

    2014-09-22

    Traditional methods for generating a light carrying orbital angular momentum (OAM) include the use of holographic diffraction gratings, vortex phase plates and spatial light modulators. Here we report a new method for highly efficient second-harmonic generation (SHG) of a light with OAM. By properly aligning an external cavity that contains a quasi-phase matching nonlinear crystal and pumping it with a light carrying OAM, mode matching between the pump light and the cavity's higher order Laguerre-Gaussian (LG) mode is achieved, SHG with a conversion efficiency of up to 10.3% is obtained. We have demonstrated for the first time that the cavity can stably operate at its higher order LG mode similar to that of a Gaussian mode. The second harmonic generated light has an OAM value that is double with respected to the OAM value of the pump light. The parameters that affect the beam quality and conversion efficiency are discussed in detail. Our work opens a brand new field in laser optics and makes the first step toward high efficiency processing using a light carrying OAM.

  20. Light generation of intracellular Ca2+ signals by a genetically encoded protein BACCS

    PubMed Central

    Ishii, Tomohiro; Sato, Koji; Kakumoto, Toshiyuki; Miura, Shigenori; Touhara, Kazushige; Takeuchi, Shoji; Nakata, Takao

    2015-01-01

    Ca2+ signals are highly regulated in a spatiotemporal manner in numerous cellular physiological events. Here we report a genetically engineered blue light-activated Ca2+ channel switch (BACCS), as an optogenetic tool for generating Ca2+ signals. BACCS opens Ca2+-selective ORAI ion channels in response to light. A BACCS variant, dmBACCS2, combined with Drosophila Orai, elevates the Ca2+ concentration more rapidly, such that Ca2+ elevation in mammalian cells is observed within 1 s on light exposure. Using BACCSs, we successfully control cellular events including NFAT-mediated gene expression. In the mouse olfactory system, BACCS mediates light-dependent electrophysiological responses. Furthermore, we generate BACCS mutants, which exhibit fast and slow recovery of intracellular Ca2+. Thus, BACCSs are a useful optogenetic tool for generating temporally various intracellular Ca2+ signals with a large dynamic range, and will be applicable to both in vitro and in vivo studies. PMID:26282514

  1. 75 FR 34776 - Florida Power & Light Company; Turkey Point Nuclear Generating Plant, Units 3 and 4...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-18

    ... COMMISSION Florida Power & Light Company; Turkey Point Nuclear Generating Plant, Units 3 and 4; Environmental... licensee), for operation of the Turkey Point Nuclear Generating Plant, Units 3 and 4, located in Florida... consider approval of an exemption for Turkey Point, Units 3 and 4, from certain requirements of 10 CFR...

  2. Seismically induced liquefaction structures in La Magdalena archaeological site, the 4th century AD Roman Complutum (Madrid, Spain)

    NASA Astrophysics Data System (ADS)

    Rodríguez-Pascua, M. A.; Silva, P. G.; Perucha, M. A.; Giner-Robles, J. L.; Heras, C.; Bastida, A. B.; Carrasco, P.; Roquero, E.; Lario, J.; Bardaji, T.; Pérez-López, R.; Elez, J.

    2016-10-01

    The ancient Roman city of Complutum (Alcalá de Henares, Madrid), founded in the 1st century AD, was one of the most important cities of Hispania. The old Roman city was destroyed, abruptly abandoned, relocated close by and rebuilt during the late 4th century AD. Destruction of the city and its relocation has not yet been explained by archaeologists. In this paper, with our multidisciplinary approach, we identify and characterize earthquake archaeological effects (EAEs) affecting the archaeological site, the La Magdalena, an agricultural holding 4 km from the core of Complutum. The most important EAEs in the site are liquefactions (sand dikes and explosive sand-gravel craters) affecting Roman structures, such as water tanks (cisterns), houses and graves. Ground liquefaction generated significant ground cracks, explosive craters and folds in foundations of buildings. Several other Roman sites throughout the valley were also abandoned abruptly during the 4th century AD, in some cases with EAEs of similar origin. This suggests the occurrence of a 5.0-6.6 Mw seismic event in the zone, in accordance with the minimum empirical limit of seismically-induced liquefaction and the maximum surface rupture length of the Henares fault.

  3. A comparative study of two generation partial light intensity imager based on liquid crystal

    NASA Astrophysics Data System (ADS)

    Tang, Yuanhe; Yang, Xusan; Gao, Haiyang; Wu, Yong; Wang, Shuiwei; Cao, Xiangang; Jia, Wanli

    2013-06-01

    Two generations of prototype partial light intensity imager (PLII) based on liquid crystal (LC) are designed and implemented to achieve imaging of objects with strong light illuminations. They can both realize object imaging by controlling each pixel of the LC for a strong light intensity of larger than 2.2×105lx. There are two ways to control the LC's transmission. One way is to adjust the applied voltage to the LC selected (Sony LCX029AMT) that realizes an adjutable light transmission of 1.28-25.60%. Another way is to change the angle of polarization of either the polarizer or analyzer and obtain a range of the light transmission of 3.35-17.73%. The 1st generation of PLII uses a closed feedback loop to control the imaging system with one CCD which requires two frames of image to realize the image gating function. The 2nd generation is an upgraded version that employs two CCDs to improve the real-time imaging performance. While the 1st generation has a lower cost and smaller volume than the 2nd generation does, the 2nd generation has a capability to more easily realize image gating at a video frequency which only requires one single image frame because of the use of two CCDs. The modulate transfer function (MTF) of the two PLII systems using the two transmission control methods is 0.586 and 0.480 respectively.

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

    PubMed

    Saravi, Sina; Quintero-Bermudez, Rafael; Setzpfandt, Frank; Asger Mortensen, N; Pertsch, Thomas

    2016-07-01

    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 maximally achievable efficiency reached for finite values of the group index at the point of phase-matching. Furthermore, we identify situations for which slow light, surprisingly, does not enhance the second-harmonic generation efficiency. Our results are corroborated by rigorous nonlinear simulations of second-harmonic generation in periodic nanobeam waveguides with loss.

  5. Spectral and spatial characteristics of third-harmonic generation in conical light beams

    SciTech Connect

    Peet, V.E.; Shchemeljov, S.V.

    2003-01-01

    Generation of resonance-enhanced third harmonic in Bessel and other conical beams is analyzed from a simple picture, where the fundamental light field is decomposed into elementary configurations of crossed plain-wave sub-beams. We show that the overall harmonic output can be derived as a superposition of all partial harmonic components driven by elementary configurations of the fundamental field. Good agreement with experimental observations has been obtained in simulation of spectral and spatial characteristics of the generated third harmonic. Some peculiarities of harmonic generation in conical light fields are discussed.

  6. Analysis of condition for uniform lighting generated by array of light emitting diodes with large view angle.

    PubMed

    Qin, Zong; Wang, Kai; Chen, Fei; Luo, Xiaobing; Liu, Sheng

    2010-08-02

    In this research, the condition for uniform lighting generated by array of LEDs with large view angle was studied. The luminous intensity distribution of LED is not monotone decreasing with view angle. A LED with freeform lens was designed as an example for analysis. In a system based on LEDs designed in house with a thickness of 20mm and rectangular arrangement, the condition for uniform lighting was derived and the analytical results demonstrated that the uniformity was not decreasing monotonously with the increasing of LED-to-LED spacing. The illuminance uniformities were calculated with Monte Carlo ray tracing simulations and the uniformity was found to increase with the increasing of certain LED-to-LED spacings anomalously. Another type of large view angle LED and different arrangements were discussed in addition. Both analysis and simulation results showed that the method is available for LED array lighting system design on the basis of large view angle LED..

  7. Simultaneous generation and focus of radially polarized light with metal-dielectric grating metasurface

    NASA Astrophysics Data System (ADS)

    Luo, Jun; Zhang, Zuojun; Song, Maowen; He, Anguo; Yu, Honglin

    2017-01-01

    Simultaneous manipulation of light polarization and phase possesses great significance for modern optical technologies. Here we propose metal-dielectric gratings capable of tailoring the polarization and phase of light based on polarization filtering with the polarization extinction ratio exceeding 10 dB and the transmittance higher than 65%. The standard radially polarized (RP) light with axially symmetric polarization distribution can be generated by using arrayed grating with gradient phase under the illumination of circularly polarized (CP) light. Besides, a RP metasurface lens with high numerical aperture is presented, which can convert the CP light into the focused radially polarized light at wavelength of 632.8 nm. This compact and efficient approach would have potential applications in beam manipulation, super-resolution imaging and integrated optics system.

  8. Spatio-temporal control of femtosecond laser filamentation and white-light generation

    NASA Astrophysics Data System (ADS)

    Kaya, N.; Kaya, G.; Strohaber, J.; Kolomenskii, A.; Schuessler, H.

    2017-02-01

    Several possibilities are investigated to control spatio-temporal characteristics of the femtosecond filamentation process and the resulting white-light generation. We controlled the development of self-focusing, and resulting locations of filaments producing white-light in water by changing the transverse spatial phase of an initial Gaussian beam with a computer generated holographic technique and a spatial light modulator. We studied intense femtosecond filamentation and propagation of femtosecond pulses with different transverse modes in water. The filament propagation length was found to increase with Bessel-Gaussian modes of the beams, when more lateral lobes were used, under the conditions of the same peak intensity, pulse duration, and size of the central peak of the incident beam. We also investigated variations of white-light generation when the delay between the two pulses was varied. With a decrease of the relative delay, an enhancement of white-light output was observed, which at near-zero delays was reverted to a suppression of white-light generation.

  9. Using 4th order Runge-Kutta method for solving a twisted Skyrme string equation

    NASA Astrophysics Data System (ADS)

    Hadi, Miftachul; Anderson, Malcolm; Husein, Andri

    2016-03-01

    We study numerical solution, especially using 4th order Runge-Kutta method, for solving a twisted Skyrme string equation. We find numerically that the value of minimum energy per unit length of vortex solution for a twisted Skyrmion string is 20.37 × 1060 eV/m.

  10. Improving the Attitudes of 4th Graders toward Older People through a Multidimensional Intergenerational Program

    ERIC Educational Resources Information Center

    Lynott, Patricia P.; Merola, Pamela R.

    2007-01-01

    The purpose of this study was to examine the effects of an intergenerational program on children's attitudes toward older people. Four 4th grade classes, one each during the years 2002 through 2005, participated in the study. The elders and school children engaged in meaningful activities over a 5 month period, including the performance of a play…

  11. 75 FR 34639 - Safety Zone; Reedville July 4th Celebration, Cockrell's Creek, Reedville, VA

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-18

    ... SECURITY Coast Guard 33 CFR Part 165 RIN 1625-AA00 Safety Zone; Reedville July 4th Celebration, Cockrell's... establishing a temporary safety zone on Cockrell's Creek in the vicinity of Reedville, Virginia in support of... impracticable. Delaying the effective date would be contrary to the safety zone's intended objectives...

  12. 77 FR 56208 - Filing Dates for the Kentucky Special Election in the 4th Congressional District

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-09-12

    ... From the Federal Register Online via the Government Publishing Office FEDERAL ELECTION COMMISSION Filing Dates for the Kentucky Special Election in the 4th Congressional District AGENCY: Federal Election Commission. ACTION: Notice of filing dates for special election. SUMMARY: Kentucky has scheduled a...

  13. 77 FR 39408 - Safety Zone; Buffalo July 4th Fireworks, Lake Erie, Buffalo, NY

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-03

    ... SECURITY Coast Guard 33 CFR Part 165 RIN 1625-AA00 Safety Zone; Buffalo July 4th Fireworks, Lake Erie, Buffalo, NY AGENCY: Coast Guard, DHS. ACTION: Temporary final rule. SUMMARY: The Coast Guard is establishing a temporary safety zone on Lake Erie, Buffalo, NY. This safety zone is intended to...

  14. MAIN GATE, INTERSECTION OF 4TH AVE (200 NORTH) AND N ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    MAIN GATE, INTERSECTION OF 4TH AVE (200 NORTH) AND N STREET (895 EAST), SALT LAKE CITY, UT. VIEW LOOKING EAST THROUGH MAIN CEMETERY GATE TO CEMETERY'S MAIN STREET, REPHOTOGRAPH OF HISTORIC SHIPLER PHOTO # 18276, UTAH STATE HISTORICAL SOCIETY COLLECTION. - Salt Lake City Cemetery, 200 N Street, Salt Lake City, Salt Lake County, UT

  15. Polarimetric Microwave Emission from Snow Surface: 4th Strokes Component Analysis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The effect of ice on the polarimetric 4th Stokes component observations is investigated using WindSat data over Antarctica. The difference in the magnitude of the signal observed during (July 2003) and summer (February 2004) months is investigated using a second harmonic sine function of the azimuth...

  16. 33 CFR 165.166 - Safety Zone: Macy's July 4th Fireworks, East River, NY.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Fireworks, East River, NY. 165.166 Section 165.166 Navigation and Navigable Waters COAST GUARD, DEPARTMENT... § 165.166 Safety Zone: Macy's July 4th Fireworks, East River, NY. (a) Regulated area. The following area...) in length, carrying persons for the purpose of viewing the fireworks, may take position in an...

  17. 33 CFR 165.166 - Safety Zone: Macy's July 4th Fireworks, East River, NY.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Fireworks, East River, NY. 165.166 Section 165.166 Navigation and Navigable Waters COAST GUARD, DEPARTMENT... § 165.166 Safety Zone: Macy's July 4th Fireworks, East River, NY. (a) Regulated area. The following area...) in length, carrying persons for the purpose of viewing the fireworks, may take position in an...

  18. 33 CFR 165.166 - Safety Zone: Macy's July 4th Fireworks, East River, NY.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Fireworks, East River, NY. 165.166 Section 165.166 Navigation and Navigable Waters COAST GUARD, DEPARTMENT... § 165.166 Safety Zone: Macy's July 4th Fireworks, East River, NY. (a) Regulated area. The following area...) in length, carrying persons for the purpose of viewing the fireworks, may take position in an...

  19. 33 CFR 165.166 - Safety Zone: Macy's July 4th Fireworks, East River, NY.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Fireworks, East River, NY. 165.166 Section 165.166 Navigation and Navigable Waters COAST GUARD, DEPARTMENT... § 165.166 Safety Zone: Macy's July 4th Fireworks, East River, NY. (a) Regulated area. The following area...) in length, carrying persons for the purpose of viewing the fireworks, may take position in an...

  20. 33 CFR 165.166 - Safety Zone: Macy's July 4th Fireworks, East River, NY.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Fireworks, East River, NY. 165.166 Section 165.166 Navigation and Navigable Waters COAST GUARD, DEPARTMENT... § 165.166 Safety Zone: Macy's July 4th Fireworks, East River, NY. (a) Regulated area. The following area...) in length, carrying persons for the purpose of viewing the fireworks, may take position in an...

  1. 75 FR 33170 - Safety Zone; City of Martinez 4th of July Fireworks, Martinez, CA

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-11

    ... SECURITY Coast Guard 33 CFR Part 165 RIN 1625-AA00 Safety Zone; City of Martinez 4th of July Fireworks, Martinez, CA AGENCY: Coast Guard, DHS. ACTION: Temporary final rule. SUMMARY: The Coast Guard is establishing a temporary safety zone for the launching of fireworks being sponsored by the City of...

  2. 11. 4TH FLOOR, HOTEL SOAP LINE No. 6 TO NORTHEAST, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    11. 4TH FLOOR, HOTEL SOAP LINE No. 6 TO NORTHEAST, WITH WRAPPER (LEFT), PRESS (CENTER), AND CUTTER (RIGHT, BEHIND CHUTE); BUCKET CONVEYOR AT RIGHT MOVED WASTE FROM PRESS TO 5TH FLOOR FOR RE-MANUFACTURE - Colgate & Company Jersey City Plant, Building No. B-14, 54-58 Grand Street, Jersey City, Hudson County, NJ

  3. Reading Development and Achievement of 4th-Grade Hmong Students

    ERIC Educational Resources Information Center

    Mahowald, Megan; Loughnane, Megan

    2016-01-01

    Researchers and practitioners alike have noted that Hmong students in the United States do not achieve as well as their monolingual peers and other bilingual students. The current mixed-methods study is designed to describe reading development and achievement of 4th-grade Hmong students in one large, urban school district. This study explores the…

  4. 4th level of 1945 warehouse indicating drag conveyor. From here ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    4th level of 1945 warehouse indicating drag conveyor. From here screenings were pumped from the elevator leg to this conveyor. The grains were ground, then conveyed back down to the first floor for bagging. - Stewart Company Grain Elevator, 16 West Carson Street, Pittsburgh, Allegheny County, PA

  5. Generation of bright broadband-squeezed light and broadband quantum interferometry

    NASA Astrophysics Data System (ADS)

    Xie, Daruo

    Generation of bright broadband squeezed light is of great interest from the viewpoint of experimental and applied physics. Squeezed states of the light field can be used for ultrasensitive interferometry measurements. Broadband light squeezing also can find a direct application as classical channel capacity enhancement in broadband coherent optical communication. A degenerate (type-I) optical parametric amplifier (OPA), which is based on a periodically poled nonlinear crystal, has been built for research in quantum optics, to provide a source of broadband squeezed light. Through parametric down-conversion process in the nonlinear crystal, energy of pump light was converted to OPA's output 1064 nm light, and the output light is phase-quadrature broadband squeezed. Moreover, the OPA has been operated in the state of a free-running emitter with no servo loops for cavity length control and phase control to verify the intrinsic stability of the OPA. Sensitivity enhancement of optical interferometry has been observed by homodyne detection measurements with the OPO-generated broadband squeezed light as an input beam. This experiment is also a demonstration of the increase of the classical channel capacity beyond that of a coherent state in coherent optical communication.

  6. Attosecond Lighthouses: How To Use Spatiotemporally Coupled Light Fields To Generate Isolated Attosecond Pulses

    NASA Astrophysics Data System (ADS)

    Vincenti, H.; Quéré, F.

    2012-03-01

    Under the effect of even simple optical components, the spatial properties of femtosecond laser beams can vary over the duration of the light pulse. We show how using such spatiotemporally coupled light fields in high harmonic generation experiments (e.g., in gases or dense plasmas) enables the production of attosecond lighthouses, i.e., sources emitting a collection of angularly well-separated light beams, each consisting of an isolated attosecond pulse. This general effect opens the way to a new generation of light sources, particularly suitable for attosecond pump-probe experiments, and provides a new tool for ultrafast metrology, for instance, giving direct access to fluctuations of the carrier-envelope relative phase of even the most intense ultrashort lasers.

  7. Nanocrystal-based hybrid white light generation with tunable colour parameters

    NASA Astrophysics Data System (ADS)

    Nizamoglu, S.; Demir, H. V.

    2007-09-01

    We present the hybridization of CdSe/ZnS core shell nanocrystals (NCs) on InGaN/GaN based blue/near-UV LEDs to generate light widely tunable across the visible spectral range and especially within the white region of the CIE (1931) chromaticity diagram. We report on the design, growth, fabrication and characterization of these hybrid NC-LEDs. In 26 NC-LED samples, we experimentally show the effect of the NC concentration and NC film thickness on tuning the colour properties of the generated light (tristimulus coordinates, colour rendering index and correlated temperature) and further compare layer by layer assembly and blending of NCs for integration in LEDs. With greatly tunable colour properties, these hybrid white light sources hold promise for future lighting and display applications.

  8. FOREWORD: 4th International Workshop on New Computational Methods for Inverse Problems (NCMIP2014)

    NASA Astrophysics Data System (ADS)

    2014-10-01

    This volume of Journal of Physics: Conference Series is dedicated to the scientific contributions presented during the 4th International Workshop on New Computational Methods for Inverse Problems, NCMIP 2014 (http://www.farman.ens-cachan.fr/NCMIP_2014.html). This workshop took place at Ecole Normale Supérieure de Cachan, on May 23, 2014. The prior editions of NCMIP also took place in Cachan, France, firstly within the scope of ValueTools Conference, in May 2011 (http://www.ncmip.org/2011/), and secondly at the initiative of Institut Farman, in May 2012 and May 2013, (http://www.farman.ens-cachan.fr/NCMIP_2012.html), (http://www.farman.ens-cachan.fr/NCMIP_2013.html). The New Computational Methods for Inverse Problems (NCMIP) Workshop focused on recent advances in the resolution of inverse problems. Indeed, inverse problems appear in numerous scientific areas such as geophysics, biological and medical imaging, material and structure characterization, electrical, mechanical and civil engineering, and finances. The resolution of inverse problems consists of estimating the parameters of the observed system or structure from data collected by an instrumental sensing or imaging device. Its success firstly requires the collection of relevant observation data. It also requires accurate models describing the physical interactions between the instrumental device and the observed system, as well as the intrinsic properties of the solution itself. Finally, it requires the design of robust, accurate and efficient inversion algorithms. Advanced sensor arrays and imaging devices provide high rate and high volume data; in this context, the efficient resolution of the inverse problem requires the joint development of new models and inversion methods, taking computational and implementation aspects into account. During this one-day workshop, researchers had the opportunity to bring to light and share new techniques and results in the field of inverse problems. The topics of the

  9. Slow light enhanced correlated photon pair generation in photonic-crystal coupled-resonator optical waveguides.

    PubMed

    Matsuda, Nobuyuki; Takesue, Hiroki; Shimizu, Kaoru; Tokura, Yasuhiro; Kuramochi, Eiichi; Notomi, Masaya

    2013-04-08

    We demonstrate the generation of quantum-correlated photon pairs from a Si photonic-crystal coupled-resonator optical waveguide. A slow-light supermode realized by the collective resonance of high-Q and small-mode-volume photonic-crystal cavities successfully enhanced the efficiency of the spontaneous four-wave mixing process. The generation rate of photon pairs was improved by two orders of magnitude compared with that of a photonic-crystal line defect waveguide without a slow-light effect.

  10. 75 FR 55317 - FirstLight Hydro Generating Company; City of Norwich Department of Public Utilities; Notice of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-09-10

    ... Energy Regulatory Commission FirstLight Hydro Generating Company; City of Norwich Department of Public... Schedule for Licensing and Deadline for Submission of Final Amendments September 2, 2010. Take notice that...--FirstLight Hydro Generating Company (FirstLight); and Competitor--City of Norwich Department of...

  11. Generation of two-mode bright squeezed light using a noise-suppressed amplified diode laser.

    PubMed

    Zhang, Yun; Hayasaka, Kazuhiro; Kasai, Katsuyuki

    2006-12-25

    We present the generation of nonclassical state using an amplified diode laser as a light source. The intensity noise of an amplified diode laser was significantly suppressed and reached the shot noise limit at 15 MHz using both a filter cavity and resonant optical feedback. Frequency doubling efficiency of 66% and up to 120 mW output power of green has been achieved in cw second-harmonic generation from 1080 nm to 540 nm. Bright two-mode amplitude-squeezed state was generated from a type-II nondegenerate optical parametric amplifier pumped by generated green light. The measured noise reduction is 2.1+/-0.2 dB below the shot-noise level.

  12. Light Mediated Generation of Silver Nanoparticles by Spinach Thylakoids/Chloroplasts

    PubMed Central

    Shabnam, Nisha; Sharmila, P.; Kim, Hyunook; Pardha-Saradhi, P.

    2016-01-01

    The unique potential of chloroplasts/thylakoids to harness light energy to transport electrons from H2O to various entities was exploited for reduction of Ag+ to generate nanoparticles (NPs). Spinach thylakoids/chloroplasts turned AgNO3 solutions brown in light, but not in dark. Besides showing Ag-NPs specific surface plasmon resonance band, these brown solutions showed presence of 5–30 nm crystalline NPs composed of Ag. Powder X-ray diffraction (PXRD) analysis revealed that Ag-NPs were biphasic composed of face-centered cubic Ag0 and cubic Ag2O. X-ray photoelectron spectroscopy (XPS) data further corroborated the presence of Ag2O in Ag-NPs. Limited formation of Ag-NPs in dark and increased generation of Ag0/Ag2O–NPs with increase in light intensity (photon flux density) by thylakoids/chloroplasts, established the role of light-harvesting photosynthetic machinery in generation of Ag0/Ag2O-NPs. Potential of thylakoids/chloroplasts to generate Ag-NPs from Ag+ on exposure to red and blue wavelength regions of visible light of electromagnetic spectrum, further confirmed the involvement of photosynthetic electron transport in reduction of Ag+ and generation of Ag-NPs. While light energy mediated photosynthetic electron transport donates energized electrons extracted from H2O to Ag+ to form Ag0-NPs, O2 released as a by-product during photolysis of H2O oxidizes Ag0 to form Ag2O-NPs. Our findings furnish a novel, simple, economic and green method that can be exploited for commercial production of Ag0/Ag2O-NPs. PMID:27936248

  13. Effects of Public Preschool Expenditures on the Test Scores of 4th Graders: Evidence from TIMSS

    PubMed Central

    Waldfogel, Jane; Zhai, Fuhua

    2011-01-01

    This study examines the effects of public preschool expenditures on the math and science scores of 4th graders, holding constant child, family, and school characteristics, other relevant social expenditures, and country and year effects, in seven Organization for Economic Co-operation and Development (OECD) countries -- Australia, Japan, Netherlands, New Zealand, Norway, U.K., and U.S -- using data from the 1995 and 2003 Trends in International Mathematics and Science Study (TIMSS). Our results indicate that there are small but significant positive effects of public preschool expenditures on the math and science scores of 4th graders and preschool expenditures reduce the risk of children scoring at the low level of proficiency. We also find some evidence that children from low-resource homes and homes where the test language is not always spoken may tend to gain more from increased public preschool expenditures than other children,. PMID:21442008

  14. A Generalized 4th-Order Runge-Kutta Method for the Gross-Pitaevskii Equation

    NASA Astrophysics Data System (ADS)

    Kandes, Martin

    2015-04-01

    We present the implementation of a method-of-lines approach for numerically approximating solutions of the time-dependent Gross-Pitaevksii equation in non-uniformly rotating reference frames. Implemented in parallel using a hybrid MPI + OpenMP framework, which will allow for scalable, high-resolution numerical simulations, we utilize an explicit, generalized 4th-order Runge-Kutta time-integration scheme with 2nd- and 4th-order central differences to approximate the spatial derivatives in the equation. The principal objective of this project is to model the effect(s) of inertial forces on quantized vortices within weakly-interacting dilute atomic gas Bose-Einstein condensates in the mean-field limit of the Gross-Pitaevskii equation. Here, we discuss our work-to-date and preliminary results.

  15. 76 FR 8724 - First Light Hydro Generating Company; Notice of Application Accepted for Filing, Soliciting...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-02-15

    ... Request: First Light Hydro Generating Company proposes to add a solar array (encompassing approximately 10 acres of land) as a non-project use of project lands at the Northfield Pump Storage Project (P-2485-059). The applicant states that the proposed 2MW utility grade photovoltaic solar array will provide...

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

    SciTech Connect

    Wegner, P.; Hackel, L.; Feit, M.; Parham, T.; Kozlowski, M.; Whitman, P.

    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.

  17. Generation of the "perfect" optical vortex using a liquid-crystal spatial light modulator.

    PubMed

    Ostrovsky, Andrey S; Rickenstorff-Parrao, Carolina; Arrizón, Víctor

    2013-02-15

    We introduce the concept of the perfect optical vortex whose dark hollow radius does not depend on the topological charge. It is shown analytically and experimentally that such a vortex can be approximately generated in the Fourier transforming optical system with a computer-controlled liquid-crystal spatial light modulator.

  18. Sub-nanosecond light-pulse generation with waveguide-coupled carbon nanotube transducers

    PubMed Central

    Kovalyuk, Vadim; Hennrich, Frank; Kappes, Manfred M; Goltsman, Gregory N; Pernice, Wolfram H P; Krupke, Ralph

    2017-01-01

    Carbon nanotubes (CNTs) have recently been integrated into optical waveguides and operated as electrically-driven light emitters under constant electrical bias. Such devices are of interest for the conversion of fast electrical signals into optical ones within a nanophotonic circuit. Here, we demonstrate that waveguide-integrated single-walled CNTs are promising high-speed transducers for light-pulse generation in the gigahertz range. Using a scalable fabrication approach we realize hybrid CNT-based nanophotonic devices, which generate optical pulse trains in the range from 200 kHz to 2 GHz with decay times below 80 ps. Our results illustrate the potential of CNTs for hybrid optoelectronic systems and nanoscale on-chip light sources. PMID:28144563

  19. 11th National Meeting of Organic Chemistry and 4th Meeting of Therapeutic Chemistry

    PubMed Central

    Sousa, Maria Emília; Araújo, Maria João; do Vale, Maria Luísa; Andrade, Paula B.; Branco, Paula; Gomes, Paula; Moreira, Rui; Pinho e Melo, Teresa M.V.D.; Freitas, Victor

    2016-01-01

    For the first time under the auspices of Sociedade Portuguesa de Química, the competences of two important fields of Chemistry are brought together into a single event, the 11st National Organic Chemistry Meeting and the the 4th National Medicinal Chemistry Meeting, to highlight complementarities and to promote new synergies. Abstracts of plenary lectures, oral communications, and posters presented during the meeting are collected in this report. PMID:27102166

  20. LESSONS LEARNED, HEADQUARTERS, 4TH BATTALION (AW)(SP), 60TH ARTILLERY

    DTIC Science & Technology

    The 4th Battalion (AW)(SP) 60th Artillery with attached Battery E (MG), 41st Artillery, remained assigned to I Field Force Vietnam, attached to I ...Battalion (AW)(SP), 60th Artillery, with attached Battery E (MG), 41st Artillery, was detached from 41st Artillery Group and fully attached to I Field Force...States and Free World Military Assistance Forces throughout the II Corps Tactical Zone and the I Corps Tactical Zone.

  1. 10. 4TH FLOOR, HOTEL SOAP LINE No. 6 TO SOUTHWEST, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    10. 4TH FLOOR, HOTEL SOAP LINE No. 6 TO SOUTHWEST, WITH AUTOMATIC CUTTER (LEFT), PRESS (CENTER), AND WRAPPER (RIGHT); LARGE CHUTE AT CENTER FROM 5TH FLOOR BINS TO 3RD FLOOR SOAP MILLS; OVERHEAD AND FLOOR (LOWER RIGHT) FINISHED GOODS CONVEYORS TO G BLOCK (HAER NO. NJ-71-NN) - Colgate & Company Jersey City Plant, Building No. B-14, 54-58 Grand Street, Jersey City, Hudson County, NJ

  2. 11(th) National Meeting of Organic Chemistry and 4(th) Meeting of Therapeutic Chemistry.

    PubMed

    Sousa, Maria Emília; Araújo, Maria João; do Vale, Maria Luísa; Andrade, Paula B; Branco, Paula; Gomes, Paula; Moreira, Rui; Pinho E Melo, Teresa M V D; Freitas, Victor

    2016-03-17

    For the first time under the auspices of Sociedade Portuguesa de Química, the competences of two important fields of Chemistry are brought together into a single event, the 11st National Organic Chemistry Meeting and the the 4th National Medicinal Chemistry Meeting, to highlight complementarities and to promote new synergies. Abstracts of plenary lectures, oral communications, and posters presented during the meeting are collected in this report.

  3. First-generation hybrid solar lighting collector system development and operating experience

    NASA Astrophysics Data System (ADS)

    Beshears, David; Earl, D. D.; Muhs, Jeff; Maxey, L. Curt; Capps, Gary; Stellern, Scott; Bayless, David; Switzer, Shyler

    2004-01-01

    Research is underway at Oak Ridge National Laboratory (ORNL) that could lead to entirely new, highly energy-efficient ways of lighting buildings using the power of sunlight. In addition to providing light, the hybrid lighting system will convert sunlight to electricity much more efficiently than conventional solar technologies using thermo-photovoltaic cells. In commercial buildings today, lighting consumes more electric energy than any other building end-use. It accounts for more than a third of all electricity consumed for commercial use in the United States. Typically, less than 25% of that energy actually produces light; the rest generates heat that increases the need for air-conditioning. ORNL is developing a system to reduce the energy required for lighting and the air-conditioning loads associated with it, while generating power for other uses. The system uses roof-mounted concentrators to collect and separate the visible and infrared portions of sunlight. The visible portion is distributed through large-diameter optical fibers to hybrid luminaires. (Hybrid luminaires are lighting fixtures that contain both electric lamps and fiber optics for direct sunlight distribution.) When sunlight is plentiful, the fiber optics in the luminaries, provide all or most of the light needed in an area. Unlike conventional electric lamps, they produce little heat. During times of little or no sunlight, sensor-controlled electric lamps will operate to maintain the desired illumination level. A second use of the hybrid lighting collector system is to provide sunlight for enhanced practical photosynthesis carbon dioxide mitigation. In this project the hybrid lighting collector system is being used to provide sunlight to a lab-scale photobioreactor for growing algae that is being used for CO2 mitigation. The end goal of this project is to provide a photobioreactor that can be used to mitigate CO2 in fossil fuel fire power plants. This paper will discuss the development and

  4. Graphene-based materials for hydrogen generation from light-driven water splitting.

    PubMed

    Xie, Guancai; Zhang, Kai; Guo, Beidou; Liu, Qian; Fang, Liang; Gong, Jian Ru

    2013-07-26

    Hydrogen production from solar water splitting has been considered as an ultimate solution to the energy and environmental issues. Over the past few years, graphene has made great contribution to improving the light-driven hydrogen generation performance. This article provides a comprehensive overview of the recent research progress on graphene-based materials for hydrogen evolution from light-driven water splitting. It begins with a brief introduction of the current status and basic principles of hydrogen generation from solar water splitting, and tailoring properties of graphene for application in this area. Then, the roles of graphene in hydrogen generation reaction, including an electron acceptor and transporter, a cocatalyst, a photocatalyst, and a photosensitizer, are elaborated respectively. After that, the comparison between graphene and other carbon materials in solar water splitting is made. Last, this review is concluded with remarks on some challenges and perspectives in this emerging field.

  5. 78 FR 23866 - Safety Zone; Crescent City 4th of July Fireworks; Crescent City Harbor, Crescent City, CA

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-23

    ... SECURITY Coast Guard 33 CFR Part 165 RIN 1625-AA00 Safety Zone; Crescent City 4th of July Fireworks; Crescent City Harbor, Crescent City, CA AGENCY: Coast Guard, DHS. ACTION: Notice of proposed rulemaking... Crescent City, CA in support of the Crescent City 4th of July Fireworks on July 4, 2013. This safety...

  6. 78 FR 23869 - Safety Zone; Redwood City 4th of July Fireworks Show; Port of Redwood City, Redwood City, CA

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-23

    ... SECURITY Coast Guard 33 CFR Part 165 RIN 1625-AA00 Safety Zone; Redwood City 4th of July Fireworks Show; Port of Redwood City, Redwood City, CA AGENCY: Coast Guard, DHS. ACTION: Notice of proposed rulemaking... of Redwood City near Redwood City, CA in support of the Redwood City 4th of July Fireworks Show...

  7. Efficient blue light generation using periodically poled stoichiometric lithium tantalate via resonant frequency doubling

    NASA Astrophysics Data System (ADS)

    Khademian, Ali; Jadhav, Shilpa; Shiner, David

    2014-05-01

    Convenient high power blue diode lasers with single frequency operation are still under developments and are not as well developed and cost effective as IR laser sources. Harmonic generation of IR lasers provide a viable alternative source of blue and UV light. Magnesium oxide doped periodically poled Stoichiometric Lithium Tantalate (PPMgO:SLT) has been reported to have the lowest blue, IR and blue induced IR absorption (BLIIRA) among ferroelectric crystals such as Lithium Niobate (PPLN) and Potassium Titanyl Phosphate (PPKTP). All these properties, along with higher thermal conductivity, make this crystal an excellent candidate for efficient blue light generation using second harmonic generation (SHG) in a resonant buildup cavity. Efficient resonant doubling is very sensitive to various cavity and crystal loss mechanisms. Recently we obtained 400 mW of blue light at 486 nm with net conversion efficiency of 77% using a 515 mW fiber grating stabilized IR source. Sources of conversion loss have been identified and evaluated with various methods in our investigation. These include reflection, scattering, absorption, and polarization rotation of IR light in the crystal, as well as mode mismatching and spherical aberration due to focusing lenses. The locking and electronic control functions of the cavity are automated using an internally mounted single chip microcontroller with embedded DSP (digital signal processor). Work is supported by NSF grant.

  8. Enhanced third harmonic generation using the surface states of light in periodic photonic structures

    NASA Astrophysics Data System (ADS)

    Zaytsev, Kirill I.; Gorelik, Vladimir S.; Katyba, Gleb M.; Yurchenko, Stanislav O.

    2014-10-01

    Third harmonic generation enhancement in periodic photonic structures was experimentally observed and theoretically interpreted. Nonlinear optical effects in opal globular photonic crystals (PC) have been studied under the femtosecond laser pumping. Strong dependence of the third harmonic generation efficiency on the ratio between the central pumping wavelength and the spectral location of the PC band gaps was found. Numerical simulations based on the finite difference time-domain technique for the solution of the Maxwell's equations were applied for investigations of the observed phenomenon origin. The simulation results have shown that the origin of the efficient nonlinear conversion is related with the surface state of electromagnetic field in PC. Interacting with the PC surface the light wavefront distorts coherently, and the effect of structure light focusing appears. Coherent wavefront distortion leads to the strong optical field localization, hence the light intensity within the certain PC regions increases. In case of the band gap pumping dramatic light redistribution appears; very sharp peaks of light intensity emerge in the region of the quartz globules, which leads to the high-efficient PC pumping.

  9. Characterizing edge-generated stray light sources for TPF Coronagraph pupil masks

    NASA Astrophysics Data System (ADS)

    Ceperley, Daniel; Neureuther, Andrew; Lieber, Michael; Kasdin, Jeremy

    2005-08-01

    The edge generated stray-light from corner boundary conditions, interactions with the lower mask structure, and surface plasmon polaritons that may limit Terrestrial Planet Finder Coronagraph performance are characterized. Previously a number of stray light sources, unaccounted for by the ideal thin mask theory used to design the pupil-plane masks, were identified. In this paper we illustrate and quantify the most important outstanding stray-light sources in the near-field in order to improve the model of pupil-plane mask transmission used by the Integrated Telescope Model. Corner spikes, caused by the need to bring the ideal top-hat field into compliance with the boundary conditions set forth by Maxwell's equations, form the strongest source of stray-light, accounting for up to a 1λ shift in the effective opening width per edge. Undercutting mask edges by 20° reduces this source of stray-light by more than a factor of five. Interactions between light and the lower mask structure, a secondary effect, account for only a few percent of the stray-light in the TE polarization but account for up to 50% of the stray-light in the TM polarization due to surface plasmon polaritons. Surface plasmon polaritons, surface waves that run for tens of microns and radiate at corners, form the final stray-light source. On thin masks they may account for up to a 1λ shift in the effective opening width; however, their effects can be easily mitigated by choosing a poor surface plasmon material, such as Chrome. The results presented here are being used to facilitate end-to-end system modeling through the Integrated Telescope Model.

  10. Virtual viewpoint generation for three-dimensional display based on the compressive light field

    NASA Astrophysics Data System (ADS)

    Meng, Qiao; Sang, Xinzhu; Chen, Duo; Guo, Nan; Yan, Binbin; Yu, Chongxiu; Dou, Wenhua; Xiao, Liquan

    2016-10-01

    Virtual view-point generation is one of the key technologies the three-dimensional (3D) display, which renders the new scene image perspective with the existing viewpoints. The three-dimensional scene information can be effectively recovered at different viewing angles to allow users to switch between different views. However, in the process of multiple viewpoints matching, when N free viewpoints are received, we need to match N viewpoints each other, namely matching C 2N = N(N-1)/2 times, and even in the process of matching different baselines errors can occur. To address the problem of great complexity of the traditional virtual view point generation process, a novel and rapid virtual view point generation algorithm is presented in this paper, and actual light field information is used rather than the geometric information. Moreover, for better making the data actual meaning, we mainly use nonnegative tensor factorization(NTF). A tensor representation is introduced for virtual multilayer displays. The light field emitted by an N-layer, M-frame display is represented by a sparse set of non-zero elements restricted to a plane within an Nth-order, rank-M tensor. The tensor representation allows for optimal decomposition of a light field into time-multiplexed, light-attenuating layers using NTF. Finally, the compressive light field of multilayer displays information synthesis is used to obtain virtual view-point by multiple multiplication. Experimental results show that the approach not only the original light field is restored with the high image quality, whose PSNR is 25.6dB, but also the deficiency of traditional matching is made up and any viewpoint can obtained from N free viewpoints.

  11. Light generation at the anomalous dispersion high energy range of a nonlinear opal film.

    PubMed

    Botey, Muriel; Maymó, Marc; Molinos-Gómez, Alberto; Dorado, Luis; Depine, Ricardo A; Lozano, Gabriel; Mihi, Agustín; Míguez, Hernán; Martorell, Jordi

    2009-07-20

    We study experimentally and theoretically light propagation and generation at the high energy range of a close-packed fcc photonic crystal of polystyrene spheres coated with a nonlinear material. We observe an enhancement of the second harmonic generation of light that may be explained on the basis of amplification effects arising from propagation at anomalous group velocities. Theoretical calculations are performed to support this assumption. The vector KKR method we use allows us to determine, from the linear response of the crystal, the behavior of the group velocity in our finite photonic structures when losses introduced by absorption or scattering by defects are taken into account assuming a nonzero imaginary part for the dielectric constant. In such structures, we predict large variations of the group velocity for wavelengths on the order or smaller than the lattice constant of the structure, where an anomalous group velocity behavior is associated with the flat bands of the photonic band structure. We find that a direct relation may be established between the group velocity reduction and the enhancement of a light generation processes such as the second harmonic generation we consider. However, frequencies for which the enhancement is found, in the finite photonic crystals we use, do not necessarily coincide with the frequencies of flat high energy bands.

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

    NASA Astrophysics Data System (ADS)

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

    2016-04-01

    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) model to simulate leaf absorption of photosynthetically active radiation (lAPAR) for an Amazon forest. The 3-D model scene was developed from airborne lidar data, and local measurements of leaf reflectance, aerosols, and PAR were used to model lAPAR under direct and diffuse illumination conditions. Simulated lAPAR under clear-sky and cloudy conditions was corrected for light saturation effects to estimate light utilization, the fraction of lAPAR available for photosynthesis. Although the fraction of incoming PAR absorbed by leaves was consistent throughout the year (0.80-0.82), light utilization varied seasonally (0.67-0.74), with minimum values during the Amazon dry season. Shadowing and light saturation effects moderated potential gains in forest productivity from increasing PAR during dry-season months when the diffuse fraction from clouds and aerosols was low. Comparisons between DART and other models highlighted the role of 3-D forest structure to account for seasonal changes in light utilization. Our findings highlight how directional illumination and forest 3-D structure combine to influence diurnal and seasonal variability in light utilization, independent of further changes in leaf area, leaf age, or environmental controls on canopy photosynthesis. Changing illumination geometry constitutes an alternative biophysical explanation for observed seasonality in Amazon forest productivity without changes in canopy phenology.

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

    PubMed

    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.

  14. Towards Visible Light Hydrogen Generation: Quantum Dot-Sensitization via Efficient Light Harvesting of Hybrid-TiO2

    NASA Astrophysics Data System (ADS)

    Kim, Kwanghyun; Kim, Myeong-Jong; Kim, Sun-I.; Jang, Ji-Hyun

    2013-11-01

    We report pronounced enhancement of photoelectrochemical hydrogen generation of a quantum dot-sensitized hybrid-TiO2 (QD/H-TiO2) electrode that is composed of a mesoporous TiO2 layer sandwiched by a double sided energy harvesting layer consisting of a surface-textured TiO2 inverse opals layer on the bottom and a patterned mesoporous TiO2 layer on the top. CdSe/H-TiO2 exhibits a maximum photocurrent density of ~16.2 mA/cm2, which is 35% higher than that of the optimized control sample (CdSe/P25), achieved by matching of the bandgap of quantum dot-sensitization with the wavelength where light harvesting of H-TiO2 is observed. Furthermore, CdSe/H-TiO2 under filtered exposure conditions recorded current density of ~14.2 mA/cm2, the greatest value in the visible range. The excellent performance of the quantum dot-sensitized H-TiO2 suggests that alteration of the photoelectrodes to suitable nanostructures with excellent light absorption may offer optimal strategies for attaining maximum efficiency in a variety of photoconversion systems.

  15. Towards Visible Light Hydrogen Generation: Quantum Dot-Sensitization via Efficient Light Harvesting of Hybrid-TiO2

    PubMed Central

    Kim, Kwanghyun; Kim, Myeong-Jong; Kim, Sun-I; Jang, Ji-Hyun

    2013-01-01

    We report pronounced enhancement of photoelectrochemical hydrogen generation of a quantum dot-sensitized hybrid-TiO2 (QD/H-TiO2) electrode that is composed of a mesoporous TiO2 layer sandwiched by a double sided energy harvesting layer consisting of a surface-textured TiO2 inverse opals layer on the bottom and a patterned mesoporous TiO2 layer on the top. CdSe/H-TiO2 exhibits a maximum photocurrent density of ~16.2 mA/cm2, which is 35% higher than that of the optimized control sample (CdSe/P25), achieved by matching of the bandgap of quantum dot-sensitization with the wavelength where light harvesting of H-TiO2 is observed. Furthermore, CdSe/H-TiO2 under filtered exposure conditions recorded current density of ~14.2 mA/cm2, the greatest value in the visible range. The excellent performance of the quantum dot-sensitized H-TiO2 suggests that alteration of the photoelectrodes to suitable nanostructures with excellent light absorption may offer optimal strategies for attaining maximum efficiency in a variety of photoconversion systems. PMID:24270426

  16. Generation of extended light-sheets for single and multi-photon fluorescence microscopy

    NASA Astrophysics Data System (ADS)

    Purnapatra, Subhajit B.; Pratim Mondal, Partha

    2013-07-01

    We theoretically propose and computationally demonstrate the generation of extended light-sheet for fluorescence microscopy. This is made possible by the introduction of a specially designed double-window spatial filter that allows the light to pass through the periphery and center of a cylindrical lens. When illuminated with a plane wave, the proposed filter results in an extended depth-of-focus along with side-lobes which are due to other interferences in the transverse focal plane. Computational studies show a maximum extension of light-sheet by 3.38 times for single photon excitation and 3.68 times for multiphoton excitation as compared to state-of-art single plane illumination microscopy system. This technique may facilitate the study of large biological specimens (such as Zebrafish embryo and tissue) with high spatial resolution and reduced photobleaching.

  17. Generation of XUV light by resonant frequency tripling in a two-wiggler FEL amplifier

    NASA Astrophysics Data System (ADS)

    Bonifacio, R.; Desalvosouza, L.; Pierini, P.; Scharlemann, E. T.

    FEL operation at short wavelength is limited by electron beam quality, by the availability of mirrors for oscillators, and by the availability of input sources for FEL amplifiers. It is possible to use and FEL amplifier as a resonant frequency tripling device, generating light and strong bunching at the 3rd harmonic of a conventional input source in an initial section of wiggler, then using a second section of wiggler resonant at the tripled frequency to amplify the short wavelength light. Neither mirrors nor a short-wavelength input source are required, and some relaxation of electron beam quality appears to be possible. We illustrate the scheme with a one-dimensional model and then with NUTMEG simulations of an 80 nm FEL amplifier initiated by a 240 nm input signal, in which an efficiency of conversion of electron beam power to 80 nm light of nearly 10(exp -4) was obtained.

  18. Generation of XUV light by resonant frequency tripling in a two-wiggler FEL amplifier

    SciTech Connect

    Bonifacio, R.; de Salvo Souza, L.; Pierini, P. . Dipt. di Fisica Istituto Nazionale di Fisica Nucleare, Milan ); Scharlemann, E.T. )

    1989-01-01

    FEL operation at short wavelength is limited by electron beam quality, by the availability of mirrors for oscillators, and by the availability of input sources for FEL amplifiers. It is possible to use and FEL amplifier as a resonant frequency tripling device, generating light and strong bunching at the 3rd harmonic of a conventional input source in an initial section of wiggler, then using a second section of wiggler resonant at the tripled frequency to amplify the short wavelength light. Neither mirrors nor a short-wavelength input source are required, and some relaxation of electron beam quality appears to be possible. We illustrate the scheme with a one-dimensional model and then with NUTMEG simulations of an 80 nm FEL amplifier initiated by a 240 nm input signal, in which an efficiency of conversion of electron beam power to 80 nm light of nearly 10{sup -4} was obtained. 3 refs., 6 figs., 1 tab.

  19. Generation of XUV light by resonant frequency tripling in a two-wiggler FEL amplifier

    NASA Astrophysics Data System (ADS)

    Bonifacio, R.; De Salvo Souza, L.; Pierini, P.; Scharlemann, E. T.

    1990-10-01

    FEL operation at short wavelengths is limited by electron-beam quality, by the availability of mirrors for oscillators and by the availability of input sources for FEL amplifiers. It is possible to use an FEL amplifier as a resonant-frequency tripling device, generating light and strong bunching at the third harmonic of a conventional input source in an initial wiggler section, then using a second wiggler section resonant at the tripled frequency to amplify the short-wavelength light. Neither mirrors nor a short-wavelength input source are required, and some relaxation of the electron-beam quality appears to be possible. We illustrate the scheme with a one-dimensional model and then with NUTMEG simulations of an 80 nm FEL amplifier initiated by a 240 nm input signal, in which an efficiency of the electron-beam power conversion to 80 nm light of nearly 10-4 was obtained.

  20. Discontinuous space variant sub-wavelength structures for generating radially polarized light in visible region

    NASA Astrophysics Data System (ADS)

    Ghadyani, Z.; Dmitriev, S.; Lindlein, N.; Leuchs, G.; Rusina, O.; Harder, I.

    2011-08-01

    A discontinuous space variant sub-wavelength dielectric grating is designed and fabricated for generating radially polarized light in visible region (l = 632.8 nm). The design is based on sub-wavelength silicon nitride structures introducing a retardation of p/2 by form birefringence, with space variant orientation of the optical axis. The pattern is divided into concentric ring segments with constant structural parameters, therefore reducing electron-beam writing time significantly. The design avoids the technological challenges encountered in the generation of a continuous space variant grating while maintaining good quality of the resulting polarization mode.

  1. The Anomalous Effect of Interface Traps on Generation Current in Lightly Doped Drain nMOSFET's

    NASA Astrophysics Data System (ADS)

    Ma, Xiao-Hua; Gao, Hai-Xia; Cao, Yan-Rong; Chen, Hai-Feng; Hao, Yue

    2010-05-01

    The anomalous phenomenon of generation current IGD in the lightly doped drain (LDD) nMOSFET measured under the drain bias VD-step mode is reported. We propose an assumption of activated (A) and frozen (F) traps for the VD-step mode: The A traps contributes to IGD while the F process can make them lose the roles as generation centers. The A and F regions can form the F-A region. The comparison of the F and A regions decides the role of the F-A region. The experiments confirm the assumption.

  2. Light-scattering properties of plate and column ice crystals generated in a laboratory cold chamber.

    PubMed

    Barkey, Brian; Bailey, Matt; Liou, Kuo-Nan; Hallett, John

    2002-09-20

    Angular scattering properties of ice crystal particles generated in a laboratory cloud chamber are measured with a lightweight polar nephelometer with a diode laser beam. This cloud chamber produces distinct plate and hollow column ice crystal types for light-scattering experiments and provides a controlled test bed for comparison with results computed from theory. Ice clouds composed predominantly of plates and hollow columns generated noticeable 22 degrees and 46 degrees halo patterns, which are predicted from geometric ray-tracing calculations. With the measured ice crystal shape and size distribution, the angular scattering patterns computed from geometrical optics with a significant contribution by rough surfaces closely match those observed from the nephelometer.

  3. Slow-light enhanced correlated photon pair generation in a silicon photonic crystal waveguide.

    PubMed

    Xiong, C; Monat, Christelle; Clark, Alex S; Grillet, Christian; Marshall, Graham D; Steel, M J; Li, Juntao; O'Faolain, Liam; Krauss, Thomas F; Rarity, John G; Eggleton, Benjamin J

    2011-09-01

    We report the generation of correlated photon pairs in the telecom C-band at room temperature from a dispersion-engineered silicon photonic crystal waveguide. The spontaneous four-wave mixing process producing the photon pairs is enhanced by slow-light propagation enabling an active device length of less than 100 μm. With a coincidence to accidental ratio of 12.8 at a pair generation rate of 0.006 per pulse, this ultracompact photon pair source paves the way toward scalable quantum information processing realized on-chip.

  4. Can astronomy enhance UNESCO World Heritage recognition? The paradigm of 4th Dynasty Egyptian pyramids

    NASA Astrophysics Data System (ADS)

    Belmonte, Juan Antonio

    2015-08-01

    The pyramids of Egypt, notably those of the 4th Dinasty as Giza, have always be considered an unmistikable part of human world heritage as the only surviving wonders of the Ancient World. Their majesty, technical hability and innovative character have always beeen considered as representative of ancient Egyptian ingenuity. However, past and present fringe theories about the pyramids and astronomy have always polluted the role of our discipline in the design, construction and symbolism of these impressive monuments. This is indeed unfear. Fortunately, things have started to change in the last couple of decades and now astronomy is interpreted as a neccessary tool for the correct interpretation of the astral eschatology present in the 5th and 6th Dynasty Texts of the Pyramids. Although the pyramid complexes of the 4th Dynasty are mute, there is however recent research showing that a strong astral symbolism could be hidden in many aspects of the complex architecture and in the design of these exceptional monuments. This idea comes from several hints obtained not only from planning and construction, but also from epigraphy and the analysis of celestial and local landscapes. Chronology also plays a most relevant role on this. The pyramid complexes of the 4th Dynasty at Meidum, Dahshur, Giza and Abu Rowash -- all of which enjoy UNESCO World Heritage recognition -- willl be scrutinized. As a consequence, we will show how astronomy can certainly enhance the face value of these extraordinary monuments as a definitive proof of the ancient Egyptian quest for Ma'at, i.e. their perennial obsesion for Cosmic Order.

  5. HIGH BRIGHTNESS ELECTRON GUNS FOR NEXT-GENERATION LIGHT SOURCES AND ACCELERATORS.

    SciTech Connect

    BLUEM,H.P.; BEN-ZVI,I.; SRINIVASAN-RAO,T.; ET AL.

    2004-07-05

    Next-generation light sources and accelerators are being proposed that set unique requirements for the electron source parameters. No single source is suitable for the diverse applications, which have operating characteristics ranging from high-average-current, quasi-CW, to high-peak-current, single-pulse electron beams. Advanced Energy Systems, in collaboration with our various partners, is developing a variety of electron gun concepts for these important applications.

  6. Proceedings of the 4th International Conference and Exhibition: World Congress on Superconductivity, volume 1

    NASA Technical Reports Server (NTRS)

    Krishen, Kumar (Editor); Burnham, Calvin (Editor)

    1995-01-01

    The papers presented at the 4th International Conference Exhibition: World Congress on Superconductivity held at the Marriott Orlando World Center, Orlando, Florida, are contained in this document and encompass the research, technology, applications, funding, political, and social aspects of superconductivity. Specifically, the areas covered included: high-temperature materials; thin films; C-60 based superconductors; persistent magnetic fields and shielding; fabrication methodology; space applications; physical applications; performance characterization; device applications; weak link effects and flux motion; accelerator technology; superconductivity energy; storage; future research and development directions; medical applications; granular superconductors; wire fabrication technology; computer applications; technical and commercial challenges, and power and energy applications.

  7. Proceedings of the 4th International Workshop on Tritium Effects in Plasma Facing Components

    SciTech Connect

    R. A. Causey

    1999-02-01

    The 4th International Workshop on Tritium Effects in Plasma Facing Components was held in Santa Fe, New Mexico on May 14-15, 1998. This workshop occurs every two years, and has previously been held in Livermore/California, Nagoya/Japan, and the JRC-Ispra Site in Italy. The purpose of the workshop is to gather researchers involved in the topic of tritium migration, retention, and recycling in materials used to line magnetic fusion reactor walls and provide a forum for presentation and discussions in this area. This document provides an overall summary of the workshop, the workshop agenda, a summary of the presentations, and a list of attendees.

  8. Proceedings of the 4th International Conference and Exhibition: World Congress on Superconductivity, Volume 2

    NASA Technical Reports Server (NTRS)

    Krishen, Kumar (Editor); Burnham, Calvin (Editor)

    1995-01-01

    This document contains papers presented at the 4th International Conference Exhibition: World Congress on Superconductivity held June 27-July 1, 1994 in Orlando, Florida. These documents encompass research, technology, applications, funding, political, and social aspects of superconductivity. The areas covered included: high-temperature materials; thin films; C-60 based superconductors; persistent magnetic fields and shielding; fabrication methodology; space applications; physical applications; performance characterization; device applications; weak link effects and flux motion; accelerator technology; superconductivity energy; storage; future research and development directions; medical applications; granular superconductors; wire fabrication technology; computer applications; technical and commercial challenges; and power and energy applications.

  9. Multi-Dimensional Asymptotically Stable 4th Order Accurate Schemes for the Diffusion Equation

    NASA Technical Reports Server (NTRS)

    Abarbanel, Saul; Ditkowski, Adi

    1996-01-01

    An algorithm is presented which solves the multi-dimensional diffusion equation on co mplex shapes to 4th-order accuracy and is asymptotically stable in time. This bounded-error result is achieved by constructing, on a rectangular grid, a differentiation matrix whose symmetric part is negative definite. The differentiation matrix accounts for the Dirichlet boundary condition by imposing penalty like terms. Numerical examples in 2-D show that the method is effective even where standard schemes, stable by traditional definitions fail.

  10. [Global Health. Information for change. 4th report of the Italian Observatory on Global Health].

    PubMed

    2011-01-01

    Global Health. Information for change. 4th report of the Italian Observatory on Global Health. InformAzione (InformAction) is the title of the last OISG report (Italian observatory on Global Health), dedicated to information and education, the essential bases for a conscious action aimed at decreasing inequalities. Increasing the investments in information, education and interventions oriented to global health may broaden the number of aware and informed citizens, able to start a dialogue, to make pressures to increase the interventions in favor of those in need.

  11. 76 FR 26284 - FirstLight Hydro Generating Company, City of Norwich Dept. of Public Utilities; Notice of Meeting

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-05-06

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission FirstLight Hydro Generating Company, City of Norwich Dept. of Public... will meet with FirstLight Hydro Generating Company and the City of Norwich Dept. of Public Utilities...

  12. Spectral, noise and correlation properties of intense squeezed light generated by a coupling in two laser fields

    NASA Technical Reports Server (NTRS)

    Kryuchkyan, Gagik YU.; Kheruntsyan, Karen V.

    1994-01-01

    Two schemes of four-wave mixing oscillators with nondegenerate pumps are proposed for above-threehold generation of squeezed light with nonzero mean-field amplitudes. Noise and correlation properties and optical spectra of squeezed-light beams generated in these schemes are discussed.

  13. Communicating Science to Impact Learning? A Phenomenological Inquiry into 4th and 5th Graders' Perceptions of Science Information Sources

    NASA Astrophysics Data System (ADS)

    Gelmez Burakgazi, Sevinc; Yildirim, Ali; Weeth Feinstein, Noah

    2016-04-01

    Rooted in science education and science communication studies, this study examines 4th and 5th grade students' perceptions of science information sources (SIS) and their use in communicating science to students. It combines situated learning theory with uses and gratifications theory in a qualitative phenomenological analysis. Data were gathered through classroom observations and interviews in four Turkish elementary schools. Focus group interviews with 47 students and individual interviews with 17 teachers and 10 parents were conducted. Participants identified a wide range of SIS, including TV, magazines, newspapers, internet, peers, teachers, families, science centers/museums, science exhibitions, textbooks, science books, and science camps. Students reported using various SIS in school-based and non-school contexts to satisfy their cognitive, affective, personal, and social integrative needs. SIS were used for science courses, homework/project assignments, examination/test preparations, and individual science-related research. Students assessed SIS in terms of the perceived accessibility of the sources, the quality of the content, and the content presentation. In particular, some sources such as teachers, families, TV, science magazines, textbooks, and science centers/museums ("directive sources") predictably led students to other sources such as teachers, families, internet, and science books ("directed sources"). A small number of sources crossed context boundaries, being useful in both school and out. Results shed light on the connection between science education and science communication in terms of promoting science learning.

  14. Oxygen suppresses light-driven anodic current generation by a mixed phototrophic culture.

    PubMed

    Darus, Libertus; Ledezma, Pablo; Keller, Jürg; Freguia, Stefano

    2014-12-02

    This paper describes the detrimental effect of photosynthetically evolved oxygen on anodic current generation in the presence of riboflavin upon illumination of a mixed phototrophic culture enriched from a freshwater pond at +0.6 V vs standard hydrogen electrode. In the presence of riboflavin, the phototrophic biomass in the anodic compartment produced an electrical current in response to light/dark cycles (12 h/12 h) over 12 months of operation, generating a maximum current density of 17.5 mA x m(-2) during the dark phase, whereas a much lower current of approximately 2 mA x m(-2) was generated during illumination. We found that the low current generation under light exposure was caused by high rates of reoxidation of reduced riboflavin by oxygen produced during photosynthesis. Quantification of biomass by fluorescence in situ hybridization images suggested that green algae were predominant in both the anode-based biofilm (55.1%) and the anolyte suspension (87.9%) with the remaining biovolume accounted for by bacteria. Genus-level sequencing analysis revealed that bacteria were dominated by cyanobacterium Leptolyngbia (∼35%), while the prevailing algae were Dictyosphaerium, Coelastrum, and Auxenochlorella. This study offers a key comprehension of mediator sensitivity to reoxidation by dissolved oxygen for improvement of microbial solar cell performance.

  15. Characterization of material ablation driven by laser generated intense extreme ultraviolet light

    SciTech Connect

    Tanaka, Nozomi Masuda, Masaya; Deguchi, Ryo; Murakami, Masakatsu; Fujioka, Shinsuke; Yogo, Akifumi; Nishimura, Hiroaki; Sunahara, Atsushi

    2015-09-14

    We present a comparative study on the hydrodynamic behaviour of plasmas generated by material ablation by the irradiation of nanosecond extreme ultraviolet (EUV or XUV) or infrared laser pulses on solid samples. It was clarified that the difference in the photon energy deposition and following material heating mechanism between these two lights result in the difference in the plasma parameters and plasma expansion characteristics. Silicon plate was ablated by either focused intense EUV pulse (λ = 9–25 nm, 10 ns) or laser pulse (λ = 1064 nm, 10 ns), both with an intensity of ∼10{sup 9 }W/cm{sup 2}. Both the angular distributions and energy spectra of the expanding ions revealed that the photoionized plasma generated by the EUV light differs significantly from that produced by the laser. The laser-generated plasma undergoes spherical expansion, whereas the EUV-generated plasma undergoes planar expansion in a comparatively narrow angular range. It is presumed that the EUV radiation is transmitted through the expanding plasma and directly photoionizes the samples in the solid phase, consequently forming a high-density and high-pressure plasma. Due to a steep pressure gradient along the direction of the target normal, the EUV plasma expands straightforward resulting in the narrower angular distribution observed.

  16. PREFACE: 4th International Conference on Mathematical Modeling in Physical Sciences (IC-MSquare2015)

    NASA Astrophysics Data System (ADS)

    Vlachos, Dimitrios; Vagenas, Elias C.

    2015-09-01

    The 4th International Conference on Mathematical Modeling in Physical Sciences (IC-MSQUARE) took place in Mykonos, Greece, from Friday 5th June to Monday 8th June 2015. The Conference was attended by more than 150 participants and hosted about 200 oral, poster, and virtual presentations. There were more than 600 pre-registered authors. The 4th IC-MSQUARE consisted of different and diverging workshops and thus covered various research fields where Mathematical Modeling is used, such as Theoretical/Mathematical Physics, Neutrino Physics, Non-Integrable Systems, Dynamical Systems, Computational Nanoscience, Biological Physics, Computational Biomechanics, Complex Networks, Stochastic Modeling, Fractional Statistics, DNA Dynamics, Macroeconomics etc. The scientific program was rather intense as after the Keynote and Invited Talks in the morning, three parallel oral and one poster session were running every day. However, according to all attendees, the program was excellent with a high quality of talks creating an innovative and productive scientific environment for all attendees. We would like to thank the Keynote Speaker and the Invited Speakers for their significant contribution to IC-MSQUARE. We also would like to thank the Members of the International Advisory and Scientific Committees as well as the Members of the Organizing Committee.

  17. Computational aspects of the nonlinear normal mode initialization of the GLAS 4th order GCM

    NASA Technical Reports Server (NTRS)

    Navon, I. M.; Bloom, S. C.; Takacs, L.

    1984-01-01

    Using the normal modes of the GLAS 4th Order Model, a Machenhauer nonlinear normal mode initialization (NLNMI) was carried out for the external vertical mode using the GLAS 4th Order shallow water equations model for an equivalent depth corresponding to that associated with the external vertical mode. A simple procedure was devised which was directed at identifying computational modes by following the rate of increase of BAL sub M, the partial (with respect to the zonal wavenumber m) sum of squares of the time change of the normal mode coefficients (for fixed vertical mode index) varying over the latitude index L of symmetric or antisymmetric gravity waves. A working algorithm is presented which speeds up the convergence of the iterative Machenhauer NLNMI. A 24 h integration using the NLNMI state was carried out using both Matsuno and leap-frog time-integration schemes; these runs were then compared to a 24 h integration starting from a non-initialized state. The maximal impact of the nonlinear normal mode initialization was found to occur 6-10 hours after the initial time.

  18. Spiritual Health Scale 2011: Defining and Measuring 4th Dimension of Health

    PubMed Central

    Dhar, Neera; Chaturvedi, SK; Nandan, Deoki

    2011-01-01

    In the midst of physical comforts provided by the unprecedented developments in all spheres of life, the humanity is at cross roads and looking at something beyond these means. Spirituality has now been identified globally as an important aspect for providing answers to many questions related to health and happiness. The World Health Organization is also keen at looking beyond physical, mental and social dimensions of the health, and the member countries are actively exploring the 4th Dimension of the health i.e. the spiritual health and its impact on the overall health and happiness of an individual. National Institute of Health and Family Welfare (NIHFW), realized this need and initiated a research study in this direction. In this study, an effort was made to define this 4th Dimension of health from a common worldly person's perspective and measure it. 3 Domains, 6 Constructs and 27 Determinants of spiritual health were identified through a scientific process. A statistically reliable and valid Spiritual Health Scale (SHS 2011) containing 114 items has been developed. Construct validity and test- retest reliability has been established for urban educated adult population. The scale is first of its kind in the world to measure the spiritual health of a common worldly person, which is devoid of religious and cultural bias. Its items have universal applicability. PMID:22279257

  19. Ultrafast laser parallel microdrilling using multiple annular beams generated by a spatial light modulator

    NASA Astrophysics Data System (ADS)

    Kuang, Zheng; Perrie, Walter; Edwardson, Stuart P.; Fearon, Eamonn; Dearden, Geoff

    2014-03-01

    Ultrafast laser parallel microdrilling using diffractive multiple annular beam patterns is demonstrated in this paper. The annular beam was generated by diffractive axicon computer generated holograms (CGHs) using a spatial light modulator. The diameter of the annular beam can be easily adjusted by varying the radius of the smallest ring in the axicon. Multiple annular beams with arbitrary arrangement and multiple annular beam arrays were generated by superimposing an axicon CGH onto a grating and lenses algorithm calculated multi-beam CGH and a binary Dammann grating CGH, respectively. Microholes were drilled through a 0.03 mm thick stainless steel foil using the multiple annular beams. By avoiding huge laser output attenuation and mechanical annular scanning, the processing is ˜200 times faster than the normal single beam processing.

  20. Generating and Separating Twisted Light by gradient-rotation Split-Ring Antenna Metasurfaces.

    PubMed

    Zeng, Jinwei; Li, Ling; Yang, Xiaodong; Gao, Jie

    2016-05-11

    Nanoscale compact optical vortex generators promise substantially significant prospects in modern optics and photonics, leading to many advances in sensing, imaging, quantum communication, and optical manipulation. However, conventional vortex generators often suffer from bulky size, low vortex mode purity in the converted beam, or limited operation bandwidth. Here, we design and demonstrate gradient-rotation split-ring antenna metasurfaces as unique spin-to-orbital angular momentum beam converters to simultaneously generate and separate pure optical vortices in a broad wavelength range. Our proposed design has the potential for realizing miniaturized on-chip OAM-multiplexers, as well as enabling new types of metasurface devices for the manipulation of complex structured light beams.

  1. Generation of Vector Partially Coherent Optical Sources Using Phase-Only Spatial Light Modulators

    NASA Astrophysics Data System (ADS)

    Hyde, Milo W.; Bose-Pillai, Santasri; Voelz, David G.; Xiao, Xifeng

    2016-12-01

    A simple and flexible optical system for generating electromagnetic or vector partially coherent sources or beams is presented. The alternative design controls field amplitude (beam shape), coherence, and polarization using only spatial light modulators. This improvement makes the apparatus simpler to construct and significantly increases the flexibility of vector partially coherent source generators by allowing many different types of sources to be produced without changing the physical setup. The system's layout and theoretical foundations are thoroughly discussed. The utility and flexibility of the proposed system are demonstrated by producing a vector Schell-model and non-Schell-model source. The experimental results are compared to theoretical predictions to validate the design. Lastly, design aspects, which must be considered when building a vector partially coherent source generator for a specific application, are discussed.

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

    PubMed

    Rico, S; Antonijoan, Rm; Barbanoj, Mj

    2009-08-31

    In 2003 a consensus group on new-generation antihistamines (CONGA) defined the characteristics required for a third-generation H(1) 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 H(1) inverse agonist. Perhaps the answer to the quest for new-generation antihistamines lies not only in H(1) but in a combined approach with other histamine receptors.

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

    PubMed Central

    Rico, S; Antonijoan, RM; Barbanoj, MJ

    2009-01-01

    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. PMID:21437146

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

    PubMed

    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

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

    NASA Astrophysics Data System (ADS)

    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 )

  6. [Giant cell tumor of the 4th metacarpal bone of the left hand. Apropos of a case].

    PubMed

    Kamel, E J; Pinto, J A; Potenza, L; Michelena, A; Perez Signini, F; Fuenmayor, A

    1983-01-01

    He is a 46 year old patient that consults on a tumor that deforms the back of his left hand. The X-ray examination shows a bone osteolytic tumor with complete dis appearance of the 4th metacarpal. Surgical removal of the tumor was practiced with immediate reconstruction of the 4th metacarpal by an oseo-iliac graft. Anatomopathological examination. It is an ovoid tumor 6.5 long and irregular surface.

  7. Light-emitting nanocomposite CdS-polymer electrospun fibres via in situ nanoparticle generation

    NASA Astrophysics Data System (ADS)

    di Benedetto, Francesca; Camposeo, Andrea; Persano, Luana; Laera, Anna Maria; Piscopiello, Emanuela; Cingolani, Roberto; Tapfer, Leander; Pisignano, Dario

    2011-10-01

    We report on the simple, in situ generation of CdS nanocrystals inside electrospun polymer fibres by thermal decomposition of a cadmium thiolate precursor, leading to nanocomposite light-emitting fibres. The modifications induced in the precursor by the thermal decomposition are investigated by a morphological, structural and spectroscopic analysis of the resulting nanocomposite fibres. This approach allows us to overcome nanofabrication difficulties related to disfavoured micro- or nanofluidic molecular flow as given by the direct incorporation of particles in the electrospinning solution. This method therefore enables the synthesis of luminescent, CdS-based composite fibres with emission peaked in the visible range, suitable as building blocks for nanophotonic devices based on light-emitting nanomaterials.

  8. Phase-controllable spin wave generation in iron garnet by linearly polarized light pulses

    SciTech Connect

    Yoshimine, Isao; Iida, Ryugo; Shimura, Tsutomu; Satoh, Takuya; Stupakiewicz, Andrzej; Maziewski, Andrzej

    2014-07-28

    A phase-controlled spin wave was non-thermally generated in bismuth-doped rare-earth iron garnet by linearly polarized light pulses. We controlled the initial phase of the spin wave continuously within a range of 180° by changing the polarization azimuth of the excitation light. The azimuth dependences of the initial phase and amplitude of the spin wave were attributed to a combination of the inverse Cotton-Mouton effect and photoinduced magnetic anisotropy. Temporally and spatially resolved spin wave propagation was observed with a CCD camera, and the waveform was in good agreement with calculations. A nonlinear effect of the spin excitation was observed for excitation fluences higher than 100 mJ/cm{sup 2}.

  9. Quasi one-dimensional light beam generated by a graded-index microsphere.

    PubMed

    Kong, Soon-Cheol; Taflove, Allen; Backman, Vadim

    2009-03-02

    An optically illuminated micron-scale dielectric sphere can generate a photonic nanojet - a nonresonant propagating beam phenomenon of high amplitude, narrow waist, and substantial sensitivity to the presence of nanometer-scale particles and geometric features located within the beam. Via three-dimensional finite-difference time-domain computational electrodynamics modeling of illuminated graded-index microspheres, we have found that the useful length of a photonic nanojet can be increased by an order-of-magnitude to approximately 20 wavelengths. This is effectively a quasi one-dimensional light beam which may be useful for optical detection of natural or artificially introduced nanostructures deeply embedded within biological cells. Of particular interest in this regard is a potential application to visible-light detection of nanometer-scale anomalies within biological cells indicative of early-stage cancer.

  10. Quasi one-dimensional light beam generated by a graded-index microsphere

    PubMed Central

    Kong, Soon-Cheol; Taflove, Allen; Backman, Vadim

    2009-01-01

    An optically illuminated micron-scale dielectric sphere can generate a photonic nanojet – a nonresonant propagating beam phenomenon of high amplitude, narrow waist, and substantial sensitivity to the presence of nanometer-scale particles and geometric features located within the beam. Via three-dimensional finite-difference time-domain computational electrodynamics modeling of illuminated graded-index microspheres, we have found that the useful length of a photonic nanojet can be increased by an order-of-magnitude to approximately 20 wavelengths. This is effectively a quasi one-dimensional light beam which may be useful for optical detection of natural or artificially introduced nanostructures deeply embedded within biological cells. Of particular interest in this regard is a potential application to visible-light detection of nanometer-scale anomalies within biological cells indicative of early-stage cancer. PMID:19259213

  11. 30 CFR 72.502 - Requirements for nonpermissible light-duty diesel-powered equipment other than generators and...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... diesel-powered equipment other than generators and compressors. 72.502 Section 72.502 Mineral Resources... Requirements for nonpermissible light-duty diesel-powered equipment other than generators and compressors. (a... chapter), other than generators and compressors, introduced into an underground area of an...

  12. 30 CFR 72.502 - Requirements for nonpermissible light-duty diesel-powered equipment other than generators and...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... diesel-powered equipment other than generators and compressors. 72.502 Section 72.502 Mineral Resources... Requirements for nonpermissible light-duty diesel-powered equipment other than generators and compressors. (a... chapter), other than generators and compressors, introduced into an underground area of an...

  13. 30 CFR 72.502 - Requirements for nonpermissible light-duty diesel-powered equipment other than generators and...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... diesel-powered equipment other than generators and compressors. 72.502 Section 72.502 Mineral Resources... Requirements for nonpermissible light-duty diesel-powered equipment other than generators and compressors. (a... chapter), other than generators and compressors, introduced into an underground area of an...

  14. 30 CFR 72.502 - Requirements for nonpermissible light-duty diesel-powered equipment other than generators and...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... diesel-powered equipment other than generators and compressors. 72.502 Section 72.502 Mineral Resources... Requirements for nonpermissible light-duty diesel-powered equipment other than generators and compressors. (a... chapter), other than generators and compressors, introduced into an underground area of an...

  15. 30 CFR 72.502 - Requirements for nonpermissible light-duty diesel-powered equipment other than generators and...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... diesel-powered equipment other than generators and compressors. 72.502 Section 72.502 Mineral Resources... Requirements for nonpermissible light-duty diesel-powered equipment other than generators and compressors. (a... chapter), other than generators and compressors, introduced into an underground area of an...

  16. 1:1 Ground-track resonance in a uniformly rotating 4th degree and order gravitational field

    NASA Astrophysics Data System (ADS)

    Feng, Jinglang; Noomen, Ron; Hou, Xiyun; Visser, Pieter; Yuan, Jianping

    2017-01-01

    Using a gravitational field truncated at the 4th degree and order, the 1:1 ground-track resonance is studied. To address the main properties of this resonance, a 1-degree of freedom (1-DOF) system is firstly studied. Equilibrium points (EPs), stability and resonance width are obtained. Different from previous studies, the inclusion of non-spherical terms higher than degree and order 2 introduces new phenomena. For a further study about this resonance, a 2-DOF model which includes a main resonance term (the 1-DOF system) and a perturbing resonance term is studied. With the aid of Poincaré sections, the generation of chaos in the phase space is studied in detail by addressing the overlap process of these two resonances with arbitrary combinations of eccentricity ( e) and inclination ( i). Retrograde orbits, near circular orbits and near polar orbits are found to have better stability against the perturbation of the second resonance. The situations of complete chaos are estimated in the e-i plane. By applying the maximum Lyapunov Characteristic Exponent (LCE), chaos is characterized quantitatively and similar conclusions can be achieved. This study is applied to three asteroids 1996 HW1, Vesta and Betulia, but the conclusions are not restricted to them.

  17. Photocatalytic hydrogen generation from water under visible light using core/shell nano-catalysts.

    PubMed

    Wang, X; Shih, K; Li, X Y

    2010-01-01

    A microemulsion technique was employed to synthesize nano-sized photocatalysts with a core (CdS)/shell (ZnS) structure. The primary particles of the photocatalysts were around 10 nm, and the mean size of the catalyst clusters in water was about 100 nm. The band gaps of the catalysts ranged from 2.25 to 2.46 eV. The experiments of photocatalytic H(2) generation showed that the catalysts (CdS)(x)/(ZnS)(1-x) with x ranging from 0.1 to 1 were able to produce hydrogen from water photolysis under visible light. The catalyst with x=0.9 had the highest rate of hydrogen production. The catalyst loading density also influenced the photo-hydrogen production rate, and the best catalyst concentration in water was 1 g L(-1). The stability of the nano-catalysts in terms of size, morphology and activity was satisfactory during an extended test period for a specific hydrogen production rate of 2.38 mmol g(-1) L(-1) h(-1) and a quantum yield of 16.1% under visible light (165 W Xe lamp, lambda>420 nm). The results demonstrate that the (CdS)/(ZnS) core/shell nano-particles are a novel photo-catalyst for renewable hydrogen generation from water under visible light. This is attributable to the large band-gap ZnS shell that separates the electron/hole pairs generated by the CdS core and hence reduces their recombinations.

  18. STO-2: Support for 4th Year Operations, Recovery, and Science ASU Co-I

    NASA Astrophysics Data System (ADS)

    Groppi, Christopher

    This is a Co-Investigator proposal for "STO-2: Support for 4th Year Operations, Recovery, and Science" with Prof. Christopher K. Walker (University of Arizona) as PI. As a participant in the STO-2 mission, ASU will participate in instrument design and construction, mission I&T, flight operations and data analysis. ASU has unique capabilities in the field of direct metal micromachining, which it will bring to bear on the STO-2 cold optical assembly, flight mixers and LO hardware. In addition, our extensive experience with receiver integration and test will supplement the capabilities of the PI institution during the I&T phase at the University of Arizona, CSBF (Palestine, TX) and in Antarctica. Both the ASU PI and student will also participate in data analysis and publication after the flight.

  19. The 4th Bologna Winter School: Hot Topics in Structural Genomics

    PubMed Central

    2003-01-01

    The 4th Bologna Winter School on Biotechnologies was held on 9–15 February 2003 at the University of Bologna, Italy, with the specific aim of discussing recent developments in bioinformatics. The school provided an opportunity for students and scientists to debate current problems in computational biology and possible solutions. The course, co-supported (as last year) by the European Science Foundation program on Functional Genomics, focused mainly on hot topics in structural genomics, including recent CASP and CAPRI results, recent and promising genomewide predictions, protein–protein and protein–DNA interaction predictions and genome functional annotation. The topics were organized into four main sections (http://www.biocomp.unibo.it). PMID:18629078

  20. Beyond the genomics blueprint: the 4th Human Variome Project Meeting, UNESCO, Paris, 2012.

    PubMed

    Kohonen-Corish, Maija R J; Smith, Timothy D; Robinson, Helen M

    2013-07-01

    The 4th Biennial Meeting of the Human Variome Project Consortium was held at the headquarters of the United Nations Educational, Scientific and Cultural Organization (UNESCO) in Paris, 11-15 June 2012. The Human Variome Project, a nongovernmental organization and an official partner of UNESCO, enables the routine collection, curation, interpretation, and sharing of information on all human genetic variation. This meeting was attended by more than 180 delegates from 39 countries and continued the theme of addressing issues of implementation in this unique project. The meeting was structured around the four main themes of the Human Variome Project strategic plan, "Project Roadmap 2012-2016": setting normative function, behaving ethically, sharing knowledge, and building capacity. During the meeting, the members held extensive discussions to formulate an action plan in the key areas of the Human Variome Project. The actions agreed on were promulgated at the Project's two Advisory Council and Scientific Advisory Committee postconference meetings.

  1. Giant viruses in the oceans: the 4th Algal Virus Workshop.

    PubMed

    Claverie, Jean-Michel

    2005-06-20

    Giant double-stranded DNA viruses (such as record breaking Acanthamoeba polyphaga Mimivirus), with particle sizes of 0.2 to 0.6 microm, genomes of 300 kbp to 1.200 kbp, and commensurate complex gene contents, constitute an evolutionary mystery. They challenge the common vision of viruses, traditionally seen as highly streamlined genomes optimally fitted to the smallest possible--filterable--package. Such giant viruses are now discovered in increasing numbers through the systematic sampling of ocean waters as well as freshwater aquatic environments, where they play a significant role in controlling phyto- and bacterio- plankton populations. The 4th Algal Virus Workshop showed that the study of these ecologically important viruses is now massively entering the genomic era, promising a better understanding of their diversity and, hopefully, some insights on their origin and the evolutionary forces that shaped their genomes.

  2. General Chemistry Collection for Students (CD-ROM), Abstract of Special Issue 16, 4th Edition

    NASA Astrophysics Data System (ADS)

    2000-07-01

    The General Chemistry Collection contains both new and previously published JCE Software programs that are intended for use by introductory-level chemistry students. These peer-reviewed programs for Macintosh and for Windows are available on a single CD-ROM for convenient distribution to and access by students, and the CD may be adopted for students to purchase as they would a textbook. General Chemistry Collection covers a broad range of topics providing students with interesting information, tutorials, and simulations that will be useful to them as they study chemistry for the first time. There are 22 programs included in the General Chemistry Collection 4th Edition. Their titles and the general chemistry topics they cover are listed in Table 1. Features in This Edition General Chemistry Collection, 4th edition includes:

    • Lessons for Introductory Chemistry and INQUAL-S, two new programs not previously published by JCE Software (abstracts appear below)
    • Writing Electron Dot Structures (1) and Viscosity Measurement: A Virtual Experiment for Windows (2), two programs published individually by JCE Software
    • Periodic Table Live! LE, a limited edition of Periodic Table Live!, 2nd Edition (3) (this replaces Chemistry Navigator (4) and Illustrated Periodic Table (5))
    • Many of the programs from previous editions (6)1
    Hardware and Software Requirements System requirements are given in Table 2. Some programs have additional requirements. See the individual program abstracts at JCE Online, or documentation included on the CD-ROM for more specific information. Licensing and Discounts for Adoptions The General Chemistry Collection is intended for use by individual students. Institutions and faculty members may adopt General Chemistry Collection 4th Edition as they would a textbook. We can arrange for CDs to be packaged with laboratory manuals or other course materials or to be sold for direct distribution to students through the campus

  3. The Automatic Light Curves Generated by Danish 1.54m Telescope

    NASA Astrophysics Data System (ADS)

    Skoda, Petr

    2015-12-01

    We present the Ondřejov Southern Photometry Survey, being conducted at the Danish 1.54m telescope in remote observing mode by several groups of Czech stellar astronomers. The automatic astrometry and photometry pipelines run on every CCD frame combined with sophisticated parallelized cross-matching and clustering algorithms result in an on-the-fly generation of light curves of every single object in the field. To allow powerful querying and visualization of current database of more than half billion of measurements, the technology of Virtual Observatory is used, combining IVOA protocols and powerful visualization tools as Aladin, TOPCAT and SPLAT-VO.

  4. Multimode nonclassical light generation through the optical-parametric-oscillator threshold

    SciTech Connect

    Chalopin, B.; Scazza, F.; Fabre, C.; Treps, N.

    2010-06-15

    We show that an optical parametric oscillator which is simultaneously resonant for several modes, either spatial or temporal, generates both below and above threshold a multimode nonclassical state of light consisting of squeezed vacuum states in all the nonoscillating modes. We confirm this prediction by an experiment dealing with the degenerate TEM{sub 01} and TEM{sub 10} modes. We show the conservation of nonclassical properties when the threshold is crossed. The experiment is made possible by the implementation of a new method to lock the relative phase of the pump and the injected beam.

  5. Biological activity of photoproducts of merocyanine 540 generated by laser-light activation

    NASA Astrophysics Data System (ADS)

    Gulliya, Kirpal S.; Chanh, Tran C.; Pervaiz, Shazib; Harriman, Anthony; Matthews, James Lester

    1992-08-01

    Controlled exposure of photoactive compounds to light prior to their use in biological targets results in the formation of heretofore unknown photoproducts. This process of photoproduct generation, termed "preactivation," renders the photactive compound capable of systemic use without further dependence on light. Preactivation of mercyanin 540 (MC540) and several other photoactive compounds is achievable by exposure to CW and pulse laser radiation. The singlet oxygen generated at excited states attacks the dye molucule itself, resulting in the formation of biologically active photoproducts. For preactivated MC540 (photoproducts of MC540) generated by exposure to argon laser light (514 nm) and light from free-electron laser, we have demonstrated its effectiveness in selective killing of certain types of cultured tumor cells as well as human immunodeficiency virus type 1 (HIV-1) with very low, if any, damage to normal cells and tisues. For example, approximately 90% of the Burkitt's lymphoma Daudi cells and HL-60 leukemic cells are killed by preactivated MC540 at a concentration of 120 μg/ml. A two-hour treatment of cultured cells with buthionine sulfoxamine followed by the treatement with preactivated MC540 reults in 99.99% inhibition of clonogenic tumor stem cell growth. We also have demonstrated that preactivated MC540 is very effective in killing cell-free and cell-associated HIV-1. It also is very effective in killing HIV-1 and simian immunodeficiency virus (SIV) in virus-infected blood in vitro as determined by reverse transcriptase, P24, P17, core antigen expression and synctium formation. Treatment of HIV-1 with preactivated MC540 renders the treated HIV-1 incapable of binding to CD4 target molecules on T cells as determined by immunofluorescence and radioimmunoprecipitation assays. In vivo toxicology studies show that preactivated MC540 is very well tolerated and does not produce any signs of adverse reaction at the therapeutic doses, as determined by

  6. Short X-ray pulses from third-generation light sources.

    PubMed

    Stepanov, A G; Hauri, C P

    2016-01-01

    High-brightness X-ray radiation produced by third-generation synchrotron light sources (TGLS) has been used for numerous time-resolved investigations in many different scientific fields. The typical time duration of X-ray pulses delivered by these large-scale machines is about 50-100 ps. A growing number of time-resolved studies would benefit from X-ray pulses with two or three orders of magnitude shorter duration. Here, techniques explored in the past for shorter X-ray pulse emission at TGLS are reviewed and the perspective towards the realisation of picosecond and sub-picosecond X-ray pulses are discussed.

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

    PubMed Central

    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.

    2013-01-01

    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. PMID:23836642

  8. Rogue-wave-like statistics in ultrafast white-light continuum generation in sapphire.

    PubMed

    Majus, D; Jukna, V; Pileckis, E; Valiulis, G; Dubietis, A

    2011-08-15

    We experimentally study the statistics of the white-light continuum generated by focusing of 130 fs, 800 nm pulses in a sapphire plate and show that the statistical distributions of the spectral intensity of the blue-shifted continuum components obey the extreme-value statistics. This rogue-wave-like behavior is detected only within a narrow input-pulse energy interval. By the use of numerical simulations, we show that the observed rogue-wave-like behavior is associated with pulse splitting and build-up of intense trailing pulse. The extreme events are thereafter suppressed by the intensity clamping.

  9. Enhancing High-Order Harmonic Generation in Light Molecules by Using Chirped Pulses

    NASA Astrophysics Data System (ADS)

    Lara-Astiaso, M.; Silva, R. E. F.; Gubaydullin, A.; Rivière, P.; Meier, C.; Martín, F.

    2016-08-01

    One of the current challenges in high-harmonic generation is to extend the harmonic cutoff to increasingly high energies while maintaining or even increasing the efficiency of the high-harmonic emission. Here we show that the combined effect of down-chirped pulses and nuclear dynamics in light molecules allows one to achieve this goal, provided that long enough IR pulses are used to allow the nuclei to move well outside the Franck-Condon region. We also show that, by varying the duration of the chirped pulse or by performing isotopic substitution while keeping the pulse duration constant, one can control the extension of the harmonic plateau.

  10. Tunable VUV light generation for resonance ionization mass spectrometry of Krypton

    NASA Astrophysics Data System (ADS)

    Strashnov, I.; Blagburn, D. J.; Thonnard, N.; Gilmour, J. D.

    2009-03-01

    Tunable coherent VUV radiation from 115.8 to 116.9 nm has been produced by non-linear four-wave sum frequency mixing in a xenon-argon mixture. 116.5 nm light generated by this means has been used as the first step in a three color, doubly resonant ionization scheme for Kr. In the process of validating the system the xenon refractive index per atom (STP) at 116.5 nm has been determined to be (n(Xe) - 1)/NXe = -6.8(±0.8) × 10-23 cm3.

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

    SciTech Connect

    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. Black-light continuum generation in a silica-core photonic crystal fiber.

    PubMed

    Sylvestre, T; Ragueh, A R; Lee, M W; Stiller, B; Fanjoux, G; Barviau, B; Mussot, A; Kudlinski, A

    2012-01-15

    We report the observation of a broadband continuum spanning from 350 to 470 nm in the black-light region of the electromagnetic spectrum as a result of picosecond pumping a solid-core silica photonic crystal fiber at 355 nm. This was achieved despite strong absorption and a large normal dispersion of silica glass in the UV. Further investigations reveal that the continuum generation results from the interplay of intermodally phase-matched four-wave mixing and cascaded Raman scattering. We also discuss the main limitations in terms of bandwidth and power due to temporal walk-off, fiber absorption, and the photo darkening effect, and we suggest simple solutions.

  13. Light-RCV: a lightweight read coverage viewer for next generation sequencing data

    PubMed Central

    2015-01-01

    Background Next-generation sequencing (NGS) technologies has brought an unprecedented amount of genomic data for analysis. Unlike array-based profiling technologies, NGS can reveal the expression profile across a transcript at the base level. Such a base-level read coverage provides further insights for alternative mRNA splicing, single-nucleotide polymorphism (SNP), novel transcript discovery, etc. However, to our best knowledge, none of existing NGS viewers can timely visualize genome-wide base-level read coverages in an interactive environment. Results This study proposes an efficient visualization pipeline and implements a lightweight read coverage viewer, Light-RCV, with the proposed pipeline. Light-RCV consists of four featured designs on the path from raw NGS data to the final visualized read coverage: i) read coverage construction algorithm, ii) multi-resolution profiles, iii) two-stage architecture and iv) storage format. With these designs, Light-RCV achieves a < 0.5s response time on any scale of genomic ranges, including whole chromosomes. Finally, a case study was performed to demonstrate the importance of visualizing base-level read coverage and the value of Light-RCV. Conclusions Compared with multi-functional genome viewers such as Artemis, Savant, Tablet and Integrative Genomics Viewer (IGV), Light-RCV is designed only for visualization. Therefore, it does not provide advanced analyses. However, its backend technology provides an efficient kernel of base-level visualization that can be easily embedded to other viewers. This viewer is the first to provide timely visualization of genome-wide read coverage at the base level in an interactive environment. The software is available for free at http://lightrcv.ee.ncku.edu.tw. PMID:26680734

  14. Report of the 4th World Climate Research Programme International Conference on Reanalyses

    NASA Technical Reports Server (NTRS)

    Bosilovich, Michael G.; Rixen, Michel; van Oevelen, Peter; Asrar, Ghassem; Compo, Gilbert; Onogi, Kazutoshi; Simmons, Adrian; Trenberth, Kevin; Behringer, Dave; Bhuiyan, Tanvir Hossain; Capps, Shannon; Chaudhuri, Ayan; Chen, Junye; Chen, Linling; Colasacco-Thumm, Nicole; Escobar, Maria Gabriela; Ferguson, Craig R.; Ishibashi, Toshiyuki; Liberato, Margarida L. R.; Meng, Jesse; Molod, Andrea; Poli, Paul; Roundy, Joshua; Willett, Kate; Wollen, Jack

    2012-01-01

    The 4th WCRP International Conference on Reanalyses provided an opportunity for the international community to review and discuss the observational and modelling research, as well as process studies and uncertainties associated with reanalysis of the Earth System and its components. Characterizing the uncertainty and quality of reanalyses is a task that reaches far beyond the international community of producers, and into the interdisciplinary research community, especially those using reanalysis products in their research and applications. Reanalyses have progressed greatly even in the last 5 years, and newer ideas, projects and data are coming forward. While reanalysis has typically been carried out for the individual domains of atmosphere, ocean and land, it is now moving towards coupling using Earth system models. Observations are being reprocessed and they are providing improved quality for use in reanalysis. New applications are being investigated, and the need for climate reanalyses is as strong as ever. At the heart of it all, new investigators are exploring the possibilities for reanalysis, and developing new ideas in research and applications. Given the many centres creating reanalyses products (e.g. ocean, land and cryosphere research centres as well as NWP and atmospheric centers), and the development of new ideas (e.g. families of reanalyses), the total number of reanalyses is increasing greatly, with new and innovative diagnostics and output data. The need for reanalysis data is growing steadily, and likewise, the need for open discussion and comment on the data. The 4th Conference was convened to provide a forum for constructive discussion on the objectives, strengths and weaknesses of reanalyses, indicating potential development paths for the future.

  15. Food-based Science Curriculum Increases 4(th) Graders Multidisciplinary Science Knowledge.

    PubMed

    Hovland, Jana A; Carraway-Stage, Virginia G; Cela, Artenida; Collins, Caitlin; Díaz, Sebastián R; Collins, Angelo; Duffrin, Melani W

    2013-10-01

    Health professionals and policymakers are asking educators to place more emphasis on food and nutrition education. Integrating these topics into science curricula using hand-on, food-based activities may strengthen students' understanding of science concepts. The Food, Math, and Science Teaching Enhancement Resource (FoodMASTER) Initiative is a compilation of programs aimed at using food as a tool to teach mathematics and science. Previous studies have shown that students experiencing the FoodMASTER curriculum were very excited about the activities, became increasingly interested in the subject matter of food, and were able to conduct scientific observations. The purpose of this study was to: 1) assess 4(th) graders food-related multidisciplinary science knowledge, and 2) compare gains in food-related science knowledge after implementation of an integrated, food-based curriculum. During the 2009-2010 school year, FoodMASTER researchers implemented a hands-on, food-based intermediate curriculum in eighteen 4(th) grade classrooms in Ohio (n=9) and North Carolina (n=9). Sixteen classrooms in Ohio (n=8) and North Carolina (n=8), following their standard science curricula, served as comparison classrooms. Students completed a researcher-developed science knowledge exam, consisting of 13 multiple-choice questions administered pre- and post-test. Only subjects with pre- and post-test scores were entered into the sample (Intervention n=343; Control n=237). No significant differences were observed between groups at pre-test. At post-test, the intervention group scored (9.95±2.00) significantly higher (p=.000) than the control group (8.84±2.37) on a 13-point scale. These findings suggest the FoodMASTER intermediate curriculum is more effective than a standard science curriculum in increasing students' multidisciplinary science knowledge related to food.

  16. Food-based Science Curriculum Increases 4th Graders Multidisciplinary Science Knowledge

    PubMed Central

    Hovland, Jana A.; Carraway-Stage, Virginia G.; Cela, Artenida; Collins, Caitlin; Díaz, Sebastián R.; Collins, Angelo; Duffrin, Melani W.

    2013-01-01

    Health professionals and policymakers are asking educators to place more emphasis on food and nutrition education. Integrating these topics into science curricula using hand-on, food-based activities may strengthen students’ understanding of science concepts. The Food, Math, and Science Teaching Enhancement Resource (FoodMASTER) Initiative is a compilation of programs aimed at using food as a tool to teach mathematics and science. Previous studies have shown that students experiencing the FoodMASTER curriculum were very excited about the activities, became increasingly interested in the subject matter of food, and were able to conduct scientific observations. The purpose of this study was to: 1) assess 4th graders food-related multidisciplinary science knowledge, and 2) compare gains in food-related science knowledge after implementation of an integrated, food-based curriculum. During the 2009–2010 school year, FoodMASTER researchers implemented a hands-on, food-based intermediate curriculum in eighteen 4th grade classrooms in Ohio (n=9) and North Carolina (n=9). Sixteen classrooms in Ohio (n=8) and North Carolina (n=8), following their standard science curricula, served as comparison classrooms. Students completed a researcher-developed science knowledge exam, consisting of 13 multiple-choice questions administered pre- and post-test. Only subjects with pre- and post-test scores were entered into the sample (Intervention n=343; Control n=237). No significant differences were observed between groups at pre-test. At post-test, the intervention group scored (9.95±2.00) significantly higher (p=.000) than the control group (8.84±2.37) on a 13-point scale. These findings suggest the FoodMASTER intermediate curriculum is more effective than a standard science curriculum in increasing students’ multidisciplinary science knowledge related to food. PMID:25152539

  17. European Code against Cancer 4th Edition: Medical exposures, including hormone therapy, and cancer.

    PubMed

    Friis, Søren; Kesminiene, Ausrele; Espina, Carolina; Auvinen, Anssi; Straif, Kurt; Schüz, Joachim

    2015-12-01

    The 4th edition of the European Code against Cancer recommends limiting - or avoiding when possible - the use of hormone replacement therapy (HRT) because of the increased risk of cancer, nevertheless acknowledging that prescription of HRT may be indicated under certain medical conditions. Current evidence shows that HRT, generally prescribed as menopausal hormone therapy, is associated with an increased risk of cancers of the breast, endometrium, and ovary, with the risk pattern depending on factors such as the type of therapy (oestrogen-only or combined oestrogen-progestogen), duration of treatment, and initiation according to the time of menopause. Carcinogenicity has also been established for anti-neoplastic agents used in cancer therapy, immunosuppressants, oestrogen-progestogen contraceptives, and tamoxifen. Medical use of ionising radiation, an established carcinogen, can provide major health benefits; however, prudent practices need to be in place, with procedures and techniques providing the needed diagnostic information or therapeutic gain with the lowest possible radiation exposure. For pharmaceutical drugs and medical radiation exposure with convincing evidence on their carcinogenicity, health benefits have to be balanced against the risks; potential increases in long-term cancer risk should be considered in the context of the often substantial and immediate health benefits from diagnosis and/or treatment. Thus, apart from HRT, no general recommendations on reducing cancer risk were given for carcinogenic drugs and medical radiation in the 4th edition of European Code against Cancer. It is crucial that the application of these measures relies on medical expertise and thorough benefit-risk evaluation. This also pertains to cancer-preventive drugs, and self-medication with aspirin or other potential chemopreventive drugs is strongly discouraged because of the possibility of serious, potentially lethal, adverse events.

  18. Comparison of the Richmond HRR 4th edition and Farnsworth-Munsell 100 Hue Test for quantitative assessment of tritan color deficiencies.

    PubMed

    Foote, Katharina G; Neitz, Maureen; Neitz, Jay

    2014-04-01

    Drugs and environmental factors can induce tritan deficiencies. The Farnsworth-Munsell (FM) 100 Hue Test has become the gold standard in measuring these acquired defects. However, the test is time consuming, and color discrimination is confounded by concentration and patience. Here, we describe a test that compares six tritan plates from the HRR Pseudoisochromatic Plates 4th edition to 16 FM 100 Hue tritan caps. CIE Standard Illuminant C was reduced over five light intensities to simulate the effects of acquired losses in the S-cone pathway. Both tests showed quantitative differences in error rates with all light levels; thus they could serve equally well for assessing acquired deficiencies. However, compared to the FM 100, the HRR took subjects about 20-40 s per trial, making it more practical.

  19. Single-layer and multilayer mirrors for current and next-generation light sources

    NASA Astrophysics Data System (ADS)

    Störmer, Michael; Horstmann, Christian; Häussler, Dietrich; Spiecker, Erdmann; Siewert, Frank; Scholze, Frank; Hertlein, Frank; Jäger, Wolfgang; Bormann, Rüdiger

    2008-08-01

    Current and next-generation light sources, for instance third generation synchrotron sources, FLASH and the future project X-FEL require single-layer and multilayer mirrors with an active optical length of more than one meter. At the GKSS research centre, a new sputtering system for the deposition of single-layer and multilayers has been installed. This new system is able to manufacture mirrors with a maximum deposition length of 1.5m. In this paper we are going to present the first results of this challenging system. The mirror properties are investigated by means of X-ray reflectometry, transmission electron microscopy and interference microscopy. The performance of the mirrors is analyzed, considering X-ray reflectivity, film thickness, micro-roughness and the uniformity of these properties over the whole deposition length. The results will be discussed and compared with former results.

  20. INSTRUMENTS AND METHODS OF INVESTIGATION: Generation of squeezed (sub-Poissonian) light by a multimode laser

    NASA Astrophysics Data System (ADS)

    Kozlovskii, A. V.

    2007-12-01

    Theoretical and experimental results of investigations into the quantum noise of multimode laser radiation are considered. The feasibility of generating light with a photon-number-squeezed (sub-Poissonian) photon distribution by a multimode laser with a homogeneously broadened line is analyzed. The conditions of noisy and noiseless (regular) pumping are considered. Photon-number fluctuations of the net laser radiation summed over all generated modes are calculated in the approximation of equidistant equal modes, as are photon-number fluctuations in an individual mode inside and outside the resonator. Output-radiation noise spectra and photon-number fluctuations are calculated for solid-state (neodymium glass, Nd:YAG) and semiconductor lasers. Theoretical results are compared with a number of experimental data obtained for semiconductor lasers in recent years.

  1. Multi-point laser spark generation for internal combustion engines using a spatial light modulator

    NASA Astrophysics Data System (ADS)

    Lyon, Elliott; Kuang, Zheng; Cheng, Hua; Page, Vincent; Shenton, Tom; Dearden, Geoff

    2014-11-01

    This paper reports on a technique demonstrating for the first time successful multi-point laser-induced spark generation, which is variable in three dimensions and derived from a single laser beam. Previous work on laser ignition of internal combustion engines found that simultaneously igniting in more than one location resulted in more stable and faster combustion - a key potential advantage over conventional spark ignition. However, previous approaches could only generate secondary foci at fixed locations. The work reported here is an experimental technique for multi-point laser ignition, in which several sparks with arbitrary spatial location in three dimensions are created by variable diffraction of a pulsed single laser beam source and transmission through an optical plug. The diffractive multi-beam arrays and patterns are generated using a spatial light modulator on which computer generated holograms are displayed. A gratings and lenses algorithm is used to accurately modulate the phase of the input laser beam and create multi-beam output. The underpinning theory, experimental arrangement and results obtained are presented and discussed.

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

    PubMed Central

    Beltran, Nohra E.; Garcia, Laura E.; Garcia-Lorenzana, Mario

    2013-01-01

    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 (P < 0.01). Light microscopy analysis allows detection of general alterations in cellular and tissular integrity, confirming gastric reactance and confocal images quantification increments obtained during ischemia. PMID:23841094

  3. Organic Polymer Dots as Photocatalysts for Visible Light-Driven Hydrogen Generation.

    PubMed

    Wang, Lei; Fernández-Terán, Ricardo; Zhang, Lei; Fernandes, Daniel L A; Tian, Lei; Chen, Hong; Tian, Haining

    2016-09-26

    For the first time, organic semiconducting polymer dots (Pdots) based on poly[(9,9'-dioctylfluorenyl-2,7-diyl)-co-(1,4-benzo-{2,1',3} thiadiazole)] (PFBT) and polystyrene grafting with carboxyl-group-functionalized ethylene oxide (PS-PEG-COOH) are introduced as a photocatalyst towards visible-light-driven hydrogen generation in a completely organic solvent-free system. With these organic Pdots as the photocatalyst, an impressive initial rate constant of 8.3 mmol h(-1)  g(-1) was obtained for visible-light-driven hydrogen production, which is 5-orders of magnitude higher than that of pristine PFBT polymer under the same catalytic conditions. Detailed kinetics studies suggest that the productive electron transfer quench of the excited state of Pdots by an electron donor is about 40 %. More importantly, we also found that the Pdots can tolerate oxygen during catalysis, which is crucial for further application of this material for light-driven water splitting.

  4. Simultaneous Filtered and Unfiltered Light Scattering Measurements in Laser Generated Air Sparks

    NASA Astrophysics Data System (ADS)

    Limbach, Christopher; Miles, Richard

    2013-09-01

    Elastic laser light scattering may be used to measure the thermofluidic properties of gases and plasmas, including but not limited to density, temperature and velocity. Most of this information is contained within the spectra of the scattered radiation. This may be measured directly through dispersion or indirectly, by passing the light through an atomic or molecular vapor filter with known absorption features. In this work, filtered and unfiltered laser light scattering is used to diagnose air sparks generated by a 1064 nm Q-switched laser. The probe laser consists of a second Q-switched Nd:YAG laser frequency doubled to 532 nm. Simultaneous unfiltered and filtered images of the scattering are captured by a Princeton Instruments ICCD camera by using a 50 mm diameter concave re-imaging mirror. The filter consists of a well-characterized molecular Iodine cell. In the shock wave formed by the laser spark, spatially resolved measurements of density, temperature and radial velocity are extracted and compared with theory and models. Measurements in the spark core probe the ion feature of the electron Thomson scattering, from which ne and T can be extracted with the assumption Te =Ti . Partial funding was provided by General Electric Global Research Center: Niskayuna, New York. The first author is also supported by a National Defense Science and Engineering Graduate Fellowship.

  5. Optimal synthesis of double-phase computer generated holograms using a phase-only spatial light modulator with grating filter.

    PubMed

    Song, Hoon; Sung, Geeyoung; Choi, Sujin; Won, Kanghee; Lee, Hong-Seok; Kim, Hwi

    2012-12-31

    We propose an optical system for synthesizing double-phase complex computer-generated holograms using a phase-only spatial light modulator and a phase grating filter. Two separated areas of the phase-only spatial light modulator are optically superposed by 4-f configuration with an optimally designed grating filter to synthesize arbitrary complex optical field distributions. The tolerances related to misalignment factors are analyzed, and the optimal synthesis method of double-phase computer-generated holograms is described.

  6. 75 FR 9591 - FirstLight Hydro Generating Company; Notice of Application for Amendment of License and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-03

    ... Federal Energy Regulatory Commission FirstLight Hydro Generating Company; Notice of Application for Amendment of License and Soliciting Comments, Motions To Intervene, and Protests February 24, 2010. Take.... c. Date Filed: June 30, 2009 and supplemented on December 4, 2009. d. Applicant: FirstLight...

  7. 75 FR 4426 - Florida Power and Light Company; Turkey Point Nuclear Generating Units 3 and 4; Environmental...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-01-27

    ... COMMISSION Florida Power and Light Company; Turkey Point Nuclear Generating Units 3 and 4; Environmental... to Florida Power and Light Company (the licensee), for operation of the Turkey Point Units 3 and 4... the beltline region of the Turkey Point Units 3 and 4 reactor pressure vessels. Environmental...

  8. PREFACE: 4th International Conference on Safe Production and Use of Nanomaterials (Nanosafe2014)

    NASA Astrophysics Data System (ADS)

    Tardif, F.; Damlencourt, J.-F.; Schuster, F.; Gaultier, V.

    2015-05-01

    This volume contains a collection of contributions presented at the 4th International Conference on Safe Production and Use of Nanomaterials (NANOSAFE 2014) held in Grenoble, France, from 18th to 20th November 2014. The issues of fast progress in the field of Nanosafety are up to the potential benefits that nanotechnology can bring to mankind. Making more efficient - more sustainable - easier to share mineral resources, increasing the yields of new energy technologies, enabling drugs that act selectively and locally are just few examples of the wide range of nanomaterial applications that currently benefit humanity. Nevertheless, the dynamic development of nanomaterials requires the adhesion from the general public who rightly demand major progresses in Nanosafety as a prerequisite. This is our exciting responsibility and challenge! Following the successful outcome of the three past international conferences on safe production and use of nanomaterials: Nanosafe 2008, 2010 and 2012, the organizing committee has the pleasure to welcoming you again to Minatec, Grenoble with some of the most famous specialists in the field. This year, two new topics have been added dealing with the "New Application of Nanomaterials" and "Nano-responsible Development" in addition to the usual issues addressed in previous Nanosafe conferences such as Expology, Detection and Characterization, Toxicology, Environmental Interactions, Nanomaterials Release, Life Cycle Analysis, Regulation and Standardization, Risk Management. The debates in 2012 proved highly successful so this formula has been kept in 2014 with 3 round tables: Nano-Responsible Development, Risks and Benefits for the Environment, Toxicology Progress. In this 4th edition, there were more than 330 registered participants from 28 different countries including 160 oral presentation covering the whole Nanosafety issues in 12 sessions, satellite workshops and round tables. This high number of participants makes this edition one of

  9. EDITORIAL: Special issue containing papers presented at the 4th IAEA Technical Meeting on the Theory of Plasma Instabilities Special issue containing papers presented at the 4th IAEA Technical Meeting on the Theory of Plasma Instabilities

    NASA Astrophysics Data System (ADS)

    Itoh, K.; Wilson, H. R.

    2010-05-01

    The 4th IAEA technical meeting (TM) on the Theory of Plasma Instabilities was held in Kyoto, May 18th--20th 2009, following the first (Seeon), second (Trieste) and third (York) meetings in this series. This IAEA-TM was motivated by the recent advances in theoretical methodology, the rapid progress in observations of laboratory and astrophysical plasmas and the evolution of fusion research as we approach the ITER era. The international advisory committee (IAC) and local organizing committee (LOC), the members of which are listed below, collaborated to define the scope and the content of the scientific programme. Young scientists were actively encouraged to participate in this TM to help stimulate their future research careers and raise their international profiles. Through these young scientists, the IAEA-TM planned to identify the future directions of research. About 90 researchers, from 13 countries and the IAEA, participated in this IAEA-TM, with 72 scientific presentations. The talks and posters generated enthusiastic discussions, contributing to the vibrancy of the meeting. This special issue of Nuclear Fusion consists of a cluster of papers, reporting some of the main contributions to the IAEA-TM. The articles in this cluster are representative of the scientific width of presentations at the meeting, spanning topics from micro-turbulence to large-scale MHD dynamics and from transport to detailed analysis of diagnostics. They demonstrate the quality and depth of the research presented at the conference. List of IAC (alphabetical order): B. Breizman (USA), S. Guenter (Germany), T. S. Hahm (USA), K. Itoh (Japan, Chair of 2009), Ya. I. Kolesnichenko (Ukraine), A. G. Peeters (UK), H. Wilson (UK) List of LOC (alphabetical order): A. Fukuyama, R. Horiuchi, S.-I. Itoh, N. Kasuya, Y. Kishimoto (co-chair), K. Kusano, J. Li, K. Mima, S. Murakami, H. Naitou, N. Nakajima, Y. Nakamura, H. Ohtani, S. Okamura, T. Ozeki, S. Sudo (co-chair), H. Sugama, Y. Todo, S. Tokuda, S

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

    NASA Astrophysics Data System (ADS)

    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.

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

    SciTech Connect

    Ulkue, Dincer; Rahighi, Javad; Winick, Herman

    2007-01-19

    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 {approx}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

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

    NASA Astrophysics Data System (ADS)

    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

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

    NASA Astrophysics Data System (ADS)

    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

  14. Two-photon bioimaging utilizing supercontinuum light generated by a high-peak-power picosecond semiconductor laser source.

    PubMed

    Yokoyama, Hiroyuki; Tsubokawa, Hiroshi; Guo, Hengchang; Shikata, Jun-ichi; Sato, Ki-ichi; Takashima, Keijiro; Kashiwagi, Kaori; Saito, Naoaki; Taniguchi, Hirokazu; Ito, Hiromasa

    2007-01-01

    We developed a novel scheme for two-photon fluorescence bioimaging. We generated supercontinuum (SC) light at wavelengths of 600 to 1200 nm with 774-nm light pulses from a compact turn-key semiconductor laser picosecond light pulse source that we developed. The supercontinuum light was sliced at around 1030- and 920-nm wavelengths and was amplified to kW-peak-power level using laboratory-made low-nonlinear-effects optical fiber amplifiers. We successfully demonstrated two-photon fluorescence bioimaging of mouse brain neurons containing green fluorescent protein (GFP).

  15. Calculation method for computer-generated holograms with cylindrical basic object light by using a graphics processing unit.

    PubMed

    Sakata, Hironobu; Hosoyachi, Kouhei; Yang, Chan-Young; Sakamoto, Yuji

    2011-12-01

    It takes an enormous amount of time to calculate a computer-generated hologram (CGH). A fast calculation method for a CGH using precalculated object light has been proposed in which the light waves of an arbitrary object are calculated using transform calculations of the precalculated object light. However, this method requires a huge amount of memory. This paper proposes the use of a method that uses a cylindrical basic object light to reduce the memory requirement. Furthermore, it is accelerated by using a graphics processing unit (GPU). Experimental results show that the calculation speed on a GPU is about 65 times faster than that on a CPU.

  16. Efficient white-light continuum generation in transparent solid media using ˜250 fs, 1053 nm laser pulses

    NASA Astrophysics Data System (ADS)

    Imran, T.; Figueira, G.

    2010-04-01

    We report white-light continuum generation in solid-state media (fused silica and sapphire) using seed pulses centered at 1053 nm and at a repetition rate of 10 Hz. We have investigated the influence of different parameters, such as changing the focal position and the energy of the incident pulse within the medium to obtain optimal white-light continuum. Preliminary results indicate that for intense laser pulses, waist position inside the media and input energy are crucial for high efficiency white-light continuum generation over the wavelength range 400-1100 nm. It was also found that pulses centered at 1053 nm generate a flatter spectrum, with higher white-light continuum efficiency. Such a flat response over a broad bandwidth in the continuum has the potential to be efficiently compressed to shorter durations.

  17. Visible-Light-Initiated Thiol-Michael Addition Polymerizations with Coumarin-Based Photobase Generators: Another Photoclick Reaction Strategy.

    PubMed

    Zhang, Xinpeng; Xi, Weixian; Wang, Chen; Podgórski, Maciej; Bowman, Christopher N

    2016-02-16

    An efficient visible-light-sensitive photobase generator for thiol-Michael addition reactions was synthesized and evaluated. This highly reactive catalyst was designed by protecting a strong base (tetramethyl guanidine, TMG) with a visible-light-responsive group which was a coumarin derivative. The coumarin-coupled TMG was shown to exhibit extraordinary catalytic activity toward initiation of the thiol-Michael reaction, including thiol-Michael addition-based polymerization, upon visible-light irradiation, leading to a stoichiometric reaction of both thiol and vinyl functional groups. Owing to its features, this visible-light photobase generator enables homogeneous network formation in thiol-Michael polymerizations and also has the potential to be exploited in other visible-light-induced, base-catalyzed thiol-click processes such as thiol-isocynate and thiol-epoxy network-forming reactions.

  18. 4th annual primary care ethics conference: ethics education and lifelong learning

    PubMed Central

    Spicer, John; McKenzie-Edwards, Emma; Misselbrook, David

    2014-01-01

    Primary care ethics is a field of study that has recently found new life, with calls to establish the relevance of ethical discussion in general practice, to gather a body of literature and to carve out an intellectual space for primary care on the academic landscape of bioethics. In this report, we reflect on the key strands of the 4th primary care ethics conference held at the Royal Society of Medicine, on a theme of ethics education and lifelong learning: first, to produce insights that have relevance for policy and practice; and second, to illustrate the idea that not only is ethics relevant in primary care, but primary care is relevant in medical ethics. Core themes included the advantages and disadvantages of prescriptive ways of doing ethics in education, ethical reflection and potential risk to professional status, the need to deal with societal change and to take on board the insights gained from empirical work, whether this is about different kinds of fatherhood, or work on the causes of moral distress in healthcare workers. PMID:25949739

  19. European Code against Cancer 4th Edition: Ionising and non-ionising radiation and cancer.

    PubMed

    McColl, Neil; Auvinen, Anssi; Kesminiene, Ausrele; Espina, Carolina; Erdmann, Friederike; de Vries, Esther; Greinert, Rüdiger; Harrison, John; Schüz, Joachim

    2015-12-01

    Ionising radiation can transfer sufficient energy to ionise molecules, and this can lead to chemical changes, including DNA damage in cells. Key evidence for the carcinogenicity of ionising radiation comes from: follow-up studies of the survivors of the atomic bombings in Japan; other epidemiological studies of groups that have been exposed to radiation from medical, occupational or environmental sources; experimental animal studies; and studies of cellular responses to radiation. Considering exposure to environmental ionising radiation, inhalation of naturally occurring radon is the major source of radiation in the population - in doses orders of magnitude higher than those from nuclear power production or nuclear fallout. Indoor exposure to radon and its decay products is an important cause of lung cancer; radon may cause approximately one in ten lung cancers in Europe. Exposures to radon in buildings can be reduced via a three-step process of identifying those with potentially elevated radon levels, measuring radon levels, and reducing exposure by installation of remediation systems. In the 4th Edition of the European Code against Cancer it is therefore recommended to: "Find out if you are exposed to radiation from naturally high radon levels in your home. Take action to reduce high radon levels". Non-ionising types of radiation (those with insufficient energy to ionise molecules) - including extremely low-frequency electric and magnetic fields as well as radiofrequency electromagnetic fields - are not an established cause of cancer and are therefore not addressed in the recommendations to reduce cancer risk.

  20. A Teaching Model for Scaffolding 4th Grade Students' Scientific Explanation Writing

    NASA Astrophysics Data System (ADS)

    Yang, Hsiu-Ting; Wang, Kuo-Hua

    2014-08-01

    Improving students scientific explanations is one major goal of science education. Both writing activities and concept mapping are reported as effective strategies for enhancing student learning of science. The purpose of this study was to examine the effect of a teaching model, named the DCI model, which integrates a Descriptive explanation writing activity, Concept mapping, and an Interpretive explanation writing activity, is introduced in a 4th grade science class to see if it would improve students' scientific explanations and understanding. A quasi-experimental design, including a non-randomized comparison group and a pre- and post-test design, was adopted for this study. An experimental group of 25 students were taught using the DCI teaching model, while a comparison group received a traditional lecture teaching. A rubric and content analysis was used to assess students' scientific explanations. The independent sample t test was used to measure difference in conceptual understanding between the two groups, before and after instruction. Then, the paired t test analysis was used to understand the promotion of the DCI teaching model. The results showed that students in the experimental group performed better than students in the comparison group, both in scientific concept understanding and explanation. Suggestions for using concept mapping and writing activities (the DCI teaching model) in science classes are provided in this study.

  1. Cutting orientations for non-complex parts in 4th axis machining

    NASA Astrophysics Data System (ADS)

    Osman Zahid, M. N.; Case, K.; Watts, D. M.

    2016-02-01

    The application of Computer Numerically Controlled (CNC) machining for Rapid Manufacturing processes (CNC-RM) exploits the innate potential of 4th axis machining. The use of an indexer allows the workpiece to be rotated to various orientations which directly increased the region accessible to the cutting tool. However, in order to avoid thin webs and preserve tool life, cutting must be executed with a minimum of three orientations even for geometrically simple parts. Recent findings have suggested the separation of cutting orientations into roughing and finishing operations. Thus, the selection of orientations in finishing processes becomes more flexible and independent. This study was conducted to identify the effects of using a minimum of two cutting orientations in finishing operations for CNC-RM applications. This method is only applicable for non-complex parts where all the features can be machined from two directions. The results of the study illustrate the positive effects of minimizing the number of orientations. Despite improvement in machining operations, the complexity in defining the cutting orientations was also reduced.

  2. The relationship between snack intake and its availability of 4th-6th graders in Taiwan.

    PubMed

    Hang, Chi-Ming; Lin, Wei; Yang, Hsiao-Chi; Pan, Wen-Harn

    2007-01-01

    The purpose of this study was to examine the relationship between the snack intake and snack availability of elementary school children. Data analyzed were from 722 4th to 6th graders' food availability and food intake questionnaires collected in the Nutrition and Health Survey in Taiwan Elementary School Children 2001-2002. The snacks commonly eaten were divided into two groups. Healthy snacks included dairy products, 100% fruit juice and fresh fruits. Unhealthy snacks included high fat/sugar snacks, cookies, candy, carbonated/sugared beverages and fast food. Structural equating modeling was used to test the models that describe the availability and intake of two snack groups. Results indicated that parents' intake and children's preference were major predictors of children intake of both healthy and unhealthy snacks. Other than that, the intake of unhealthy snacks was positively associated with "purchase by children themselves" but not the intake of healthy snacks, which was influenced predominantly by "present in home". The results support the perception that a positive family food environment is important for improving children's diet quality. To build a healthy family food environment, parents have to not only provide healthy snacks but also limit the unhealthy snacks in home. In addition to that, the role modeling of parents as eating healthy snacks instead of unhealthy snacks themselves may help children to develop similar behaviors.

  3. A 4th-order reconfigurable analog baseband filter for software-defined radio applications

    NASA Astrophysics Data System (ADS)

    Weiwei, Wang; Xuegui, Chang; Xiao, Wang; Kefeng, Han; Xi, Tan; Na, Yan; Hao, Min

    2011-04-01

    This paper presents a 4th-order reconfigurable analog baseband filter for software-defined radios. The design exploits an active-RC low pass filter (LPF) structure with digital assistant, which is flexible for tunability of filter characteristics, such as cut-off frequency, selectivity, type, noise, gain and power. A novel reconfigurable operational amplifier is proposed to realize the optimization of noise and scalability of power dissipation. The chip was fabricated in an SMIC 0.13 μm CMOS process. The main filter and frequency calibration circuit occupy 1.8 × 0.8 mm2 and 0.48 × 0.25 mm2 areas, respectively. The measurement results indicate that the filter provides Butterworth and Chebyshev responses with a wide frequency tuning range from 280 kHz to 15 MHz and a gain range from 0 to 18 dB. An IIP3 of 29 dBm is achieved under a 1.2 V power supply. The input inferred noise density varies from 41 to 133 according to a given standard, and the power consumptions are 5.46 mW for low band (from 280 kHz to 3 MHz) and 8.74 mW for high band (from 3 to 15 MHz) mode.

  4. Putting agent-based modeling to work: results of the 4th International Project Albert Workshop

    NASA Astrophysics Data System (ADS)

    Horne, Gary E.; Bjorkman, Eileen A.; Colton, Trevor

    2002-07-01

    Project Albert is an initiative of the US Marine Corps which uses a series of new models and tools, multidisciplinary teams, and the scientific method to explore questions of interest to military planners. Project Albert attempts to address key areas that traditional modeling and simulation techniques often do not capture satisfactorily and uses two data management concepts, data farming and data mining, to assist in identifying areas of interest. The current suite of models used by Project Albert includes four agent-based models that allow agents to interact with each other and produce emergent behaviors. The 4th International Project Albert Workshop was held 6-9 August 2001 in Australia. Workshop participants split into five groups, each of which attempted to apply various combinations of the Project Albert models to answer a series of questions in five areas: Control Operations; Reconnaissance, Surveillance, and Intelligence Force Mix; Precision Maneuver; Mission Area Analysis; and Peace Support Operations. This paper focuses on the methodology used during the workshop, the results of the workshop, and a summary of follow-on work since the workshop.

  5. European Code against Cancer 4th Edition: Ultraviolet radiation and cancer.

    PubMed

    Greinert, Rüdiger; de Vries, Esther; Erdmann, Friederike; Espina, Carolina; Auvinen, Anssi; Kesminiene, Ausrele; Schüz, Joachim

    2015-12-01

    Ultraviolet radiation (UVR) is part of the electromagnetic spectrum emitted naturally from the sun or from artificial sources such as tanning devices. Acute skin reactions induced by UVR exposure are erythema (skin reddening), or sunburn, and the acquisition of a suntan triggered by UVR-induced DNA damage. UVR exposure is the main cause of skin cancer, including cutaneous malignant melanoma, basal-cell carcinoma, and squamous-cell carcinoma. Skin cancer is the most common cancer in fair-skinned populations, and its incidence has increased steeply over recent decades. According to estimates for 2012, about 100,000 new cases of cutaneous melanoma and about 22,000 deaths from it occurred in Europe. The main mechanisms by which UVR causes cancer are well understood. Exposure during childhood appears to be particularly harmful. Exposure to UVR is a risk factor modifiable by individuals' behaviour. Excessive exposure from natural sources can be avoided by seeking shade when the sun is strongest, by wearing appropriate clothing, and by appropriately applying sunscreens if direct sunlight is unavoidable. Exposure from artificial sources can be completely avoided by not using sunbeds. Beneficial effects of sun or UVR exposure, such as for vitamin D production, can be fully achieved while still avoiding too much sun exposure and the use of sunbeds. Taking all the scientific evidence together, the recommendation of the 4th edition of the European Code Against Cancer for ultraviolet radiation is: "Avoid too much sun, especially for children. Use sun protection. Do not use sunbeds."

  6. CD4(+) Th2 cells are directly regulated by IL-10 during allergic airway inflammation.

    PubMed

    Coomes, S M; Kannan, Y; Pelly, V S; Entwistle, L J; Guidi, R; Perez-Lloret, J; Nikolov, N; Müller, W; Wilson, M S

    2017-01-01

    Interleukin-10 (IL-10) is an important regulatory cytokine required to control allergy and asthma. IL-10-mediated regulation of T cell-mediated responses was previously thought to occur indirectly via antigen-presenting cells. However, IL-10 can act directly on regulatory T cells and T helper type 17 (Th17) cells. In the context of allergy, it is therefore unclear whether IL-10 can directly regulate T helper type 2 (Th2) cells and whether this is an important regulatory axis during allergic responses. We sought to determine whether IL-10 signaling in CD4(+) Th2 cells was an important mechanism of immune regulation during airway allergy. We demonstrate that IL-10 directly limits Th2 cell differentiation and survival in vitro and in vivo. Ablation of IL-10 signaling in Th2 cells led to enhanced Th2 cell survival and exacerbated pulmonary inflammation in a murine model of house dust mite allergy. Mechanistically, IL-10R signaling regulated the expression of several genes in Th2 cells, including granzyme B. Indeed, IL-10 increased granzyme B expression in Th2 cells and led to increased Th2 cell death, identifying an IL-10-regulated granzyme B axis in Th2 cells controlling Th2 cell survival. This study provides clear evidence that IL-10 exerts direct effects on Th2 cells, regulating the survival of Th2 cells and severity of Th2-mediated allergic airway inflammation.

  7. PREFACE: 4th National Conference on Processing and Characterization of Materials (NCPCM 2014)

    NASA Astrophysics Data System (ADS)

    2015-02-01

    This volume contains selected full length technical papers amongst forty oral presentations made in the 4th National Conference on Processing and Characterization of Materials (NCPCM 2014), NIT Rourkela, Rourkela, Odisha, India, December 5 - 6, 2014. The first conference of the NCPCM series was held at the same place in December 2011. Seeing the enthusiasm of the participants, it was decided to organize such conference in Rourkela every year. The basic idea was to establish a periodical national forum for multi-scale approaches in processing and characterization of materials in the eastern part of India. The conference NCPCM 2014 has successfully carried the tradition of previous conferences; more than fifty participants from twenty different organizations across India have registered. The conference was consisted of six technical sessions of about fifty contributory talks along with three keynote lectures. A metallography contest was also organized during the event. Out of these, thirty four best peer-reviewed contributions are published in this volume of IOP Conference Series: Materials Science and Engineering. We would like to thank all the contributors, members of the organizing committee, session chairs as well as colleagues and students who helped with the preparation of the conference and, particularly, with the preparation of this volume. We convey our heartiest gratitude to the sponsors and advertisers for their contribution.

  8. European Code against Cancer 4th Edition: 12 ways to reduce your cancer risk.

    PubMed

    Schüz, Joachim; Espina, Carolina; Villain, Patricia; Herrero, Rolando; Leon, Maria E; Minozzi, Silvia; Romieu, Isabelle; Segnan, Nereo; Wardle, Jane; Wiseman, Martin; Belardelli, Filippo; Bettcher, Douglas; Cavalli, Franco; Galea, Gauden; Lenoir, Gilbert; Martin-Moreno, Jose M; Nicula, Florian Alexandru; Olsen, Jørgen H; Patnick, Julietta; Primic-Zakelj, Maja; Puska, Pekka; van Leeuwen, Flora E; Wiestler, Otmar; Zatonski, Witold

    2015-12-01

    This overview describes the principles of the 4th edition of the European Code against Cancer and provides an introduction to the 12 recommendations to reduce cancer risk. Among the 504.6 million inhabitants of the member states of the European Union (EU28), there are annually 2.64 million new cancer cases and 1.28 million deaths from cancer. It is estimated that this cancer burden could be reduced by up to one half if scientific knowledge on causes of cancer could be translated into successful prevention. The Code is a preventive tool aimed to reduce the cancer burden by informing people how to avoid or reduce carcinogenic exposures, adopt behaviours to reduce the cancer risk, or to participate in organised intervention programmes. The Code should also form a base to guide national health policies in cancer prevention. The 12 recommendations are: not smoking or using other tobacco products; avoiding second-hand smoke; being a healthy body weight; encouraging physical activity; having a healthy diet; limiting alcohol consumption, with not drinking alcohol being better for cancer prevention; avoiding too much exposure to ultraviolet radiation; avoiding cancer-causing agents at the workplace; reducing exposure to high levels of radon; encouraging breastfeeding; limiting the use of hormone replacement therapy; participating in organised vaccination programmes against hepatitis B for newborns and human papillomavirus for girls; and participating in organised screening programmes for bowel cancer, breast cancer, and cervical cancer.

  9. Project ASTRO: Local Coalitions for Bringing Astronomers to 4th - 9th Grade Classrooms

    NASA Astrophysics Data System (ADS)

    Fraknoi, Andrew

    1998-05-01

    We report on Project ASTRO, an NSF and NASA funded program that now links professional and amateur astronomers with local 4th through 9th grade teachers in 10 sites around the country. Each site matches and trains about 20-25 astronomer-teacher partnerships per year, focusing on hands-on, age-appropriate activities, demonstrations of the scientific method, as well as family and community outreach. Over 10,000 copies of the project's 813-page UNIVERSE AT YOUR FINGERTIPS resource and activity notebook (published by the A.S.P) are now in use in educational institututions around the world. The project's HOW-TO-MANUAL is being used as a practical guide to establishing astronomer-teacher partnerships where no formal ASTRO site exists, and a 12-minute video explaining and demonstrating the project is also available. In each of the ten sites, a coalition of educational and scientific institutions is assisting the project with in-kind donations, publicity, personnel, training, materials, etc. We are conducting an experiment (at the behest of NSF) to see to what degree the sites can become self-supporting over time. (One site, in Salt Lake City, has already received full funding from a local foundation.) We will discuss the progress of the project and will have a variety of sample materials available, including our annotated catalog of national astronomy and space science education projects (see associated URL).

  10. Generation of Antibunched Light by Excited Molecules in a Microcavity Trap

    NASA Technical Reports Server (NTRS)

    DeMartini, F.; DiGiuseppe, G.; Marrocco, M.

    1996-01-01

    The active microcavity is adopted as an efficient source of non-classical light. By this device, excited by a mode-locked laser at a rate of 100 MHz, single-photons are generated over a single field mode with a nonclassical sub-poissonian distribution. The process of adiabatic recycling within a multi-step Franck-Condon molecular optical-pumping mechanism, characterized in our case by a quantum efficiency very close to one, implies a pump self-regularization process leading to a striking n-squeezing effect. By a replication of the basic single-atom excitation process a beam of quantum photon (Fock states) can be created. The new process represents a significant advance in the modern fields of basic quantum-mechanical investigation, quantum communication and quantum cryptography.

  11. Generation of broadband entangled light through cascading nondegenerate optical parametric amplifiers

    SciTech Connect

    He Wenping; Li Fuli

    2007-07-15

    We consider a system consisting of N nondegenerate optical parametric amplifiers (NOPAs) operating below threshold and linked with each other in a cascading way, each taking the output subharmonic fields from the previous one as the input fields. The entanglement properties of the subharmonic fields from these cascading nondegenerate optical parametric amplifiers (CNOPAs) are investigated. We find that, if the input subharmonic fields of the first NOPA in the cascading line are in the vacuum state, the output fields from the later NOPAs exhibit excellent broadband entanglement, and the entanglement frequency band is broadened notably with increased number of cascading NOPAs. We also discuss the application of the entangled light generated from the CNOPAs to broadband teleportation, and find that the maximum width of the fidelity spectrum of teleportation of broadband coherent states can be greatly broadened.

  12. Red, blue, and green laser-light generation from the NYAB nonlinear crystal

    NASA Astrophysics Data System (ADS)

    Jaque Garcia, Daniel; Capmany, Juan; Sole, Jose G.

    1999-11-01

    Continuous wave red, green, and blue laser light are generated under IR-pumping crystals of Nd3+:YAl3(BO3)4 by a Ti:sapphire laser. The red (669-nm) and green (532-nm) radiations are obtained by self-frequency doubling of the fundamental laser lines at 1338 nm (4F3/2 yields 4I13/2 channel) and 1062 nm (4F3/2 yields 4I11/2 channel), respectively. Blue laser radiation (458 nm) is achieved by self-sum-frequency mixing of the main laser line at 1062 nm and the pumping radiation at 807 nm. The main spectroscopic and nonlinear properties of this crystal are included. In addition, a simple model devoted to optimizing the blue radiation is provided.

  13. On-demand hydrogen generation using nanosilicon: splitting water without light, heat, or electricity.

    PubMed

    Erogbogbo, Folarin; Lin, Tao; Tucciarone, Phillip M; LaJoie, Krystal M; Lai, Larry; Patki, Gauri D; Prasad, Paras N; Swihart, Mark T

    2013-02-13

    We demonstrate that nanosize silicon (~10 nm diameter) reacts with water to generate hydrogen 1000 times faster than bulk silicon, 100 times faster than previously reported Si structures, and 6 times faster than competing metal formulations. The H(2) production rate using 10 nm Si is 150 times that obtained using 100 nm particles, dramatically exceeding the expected effect of increased surface to volume ratio. We attribute this to a change in the etching dynamics at the nanoscale from anisotropic etching of larger silicon to effectively isotropic etching of 10 nm silicon. These results imply that nanosilicon could provide a practical approach for on-demand hydrogen production without addition of heat, light, or electrical energy.

  14. Bright squeezed-light generation by a continuous-wave semimonolithic parametric amplifier.

    PubMed

    Schneider, K; Bruckmeier, R; Hansen, H; Schiller, S; Mlynek, J

    1996-09-01

    Continuous-wave amplitude-squeezed light at 1064 nm has been generated with excellent long-term stability by use of a dual-port type I degenerate optical parametric amplifier pumped by a frequency-doubled Nd:YAG laser. A seed wave at 1064 nm is resonantly injected through the low-transmission cavity port, whereas the parametrically deamplified and squeezed output wave is extracted from the high-transmission port. Amplitude noise reduction of as much as 4.3 dB is observed directly at an output power of 0.15 mW. Stable noise suppression exceeding 3.8 dB is obtained for several hours by phase locking of the pump wave. The longterm stability and simplicity make this device suitable for sub-shot-noise metrology.

  15. White-light emission from solid carbon in aqueous solution during hydrogen generation induced by nanosecond laser pulse irradiation

    NASA Astrophysics Data System (ADS)

    Akimoto, Ikuko; Yamamoto, Shota; Maeda, Kosuke

    2016-07-01

    We previously discovered a novel method of hydrogen generation from high-grade charcoal in an aqueous solution using nanosecond laser pulse irradiation. In this paper, white-light emission during this reaction is reported: A broad spectrum over the visible range is observed above a threshold excitation energy density. The white-light emission is a simultaneous product of the hydrogen generation reaction and is attributed to blackbody radiation in accordance with Planck's Law at a temperature above 3800 K. Consequently, we propose that hydrogen generation induced by laser irradiation proceeds similarly to classical coal gasification, which features reactions at high pressure and high temperature.

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

    SciTech Connect

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

    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.

  17. SESAME -- A third generation synchrotron light source for the Middle East

    NASA Astrophysics Data System (ADS)

    Winick, Herman

    2012-03-01

    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 centre in construction in Jordan, enabling world-class research while promoting peace through scientific cooperation. Its centerpiece, a new 2.5 GeV 3rd Generation Electron Storage Ring (133m circumference, 26nm-rad emittance, 12 places for insertion devices), will provide intense light from infra-red to hard X-rays. Members of the Council (Bahrain, Cyprus, Egypt, Iran, Israel, Jordan, Pakistan, Palestinian Authority,Turkey) provide the operations budget. Voluntary contributions by several Council Members that could amount to over 20 million over 5 years are now being finalized. This, plus funds from other sources, will enable acquisition of the technical components of the new ring and the upgrading of beamline equipment donated by several European and US labs. All concrete shielding is complete. The 0.8 GeV BESSY I injector system, a gift from Germany, is now being installed. A training program has been underway since 2000. SESAME is on track to start operation with four day-one beam lines in 2015.

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

    SciTech Connect

    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.

  19. SESAME, A 3rd Generation Synchrotron Light Source for the Middle East

    SciTech Connect

    Einfeld, D.; Hasnain, S.S.; Sayers, Z.; Schopper, H.; Winick, H.; Al-Dmour, E.

    2004-05-12

    Developed under the auspices of UNESCO, SESAME (Synchrotron-light for Experimental Science and Applications in the Middle East) will be a major international research centre in the Middle East and Mediterranean region. On 6th of January 2003, the official foundation of SESAME took place. The facility is located in Allan, Jordan, 30 km North-West of Amman. As of August 2003 the Founding Members are Bahrain, Egypt, Iran, Israel, Jordan, Pakistan, Palestine, Turkey and United Arabic Emirates, representing a population of over 300 million. SESAME will be a 2.5 GeV 3rd Generation light source (emittance 24.6 nm.rad, circumference {approx}125m). About 40% of the circumference is available for insertion devices (average length 2.75m) in 13 straight sections. Beam lines are up to 36m. The site and a building are provided by Jordan. Construction started in August 2003. The scientific program will start with up to 6 beam lines: MAD Protein Crystallography, SAXS and WAXS for polymers and proteins, Powder Diffraction for material science, UV/VUV/SXR Photoelectron Spectroscopy and Photoabsorption Spectroscopy, IR Spectroscopy, and EXAFS.

  20. Efficient photochemical generation of peroxycarboxylic nitric anhydrides with ultraviolet light-emitting diodes

    NASA Astrophysics Data System (ADS)

    Rider, N. D.; Taha, Y. M.; Odame-Ankrah, C. A.; Huo, J. A.; Tokarek, T. W.; Cairns, E.; Moussa, S. G.; Liggio, J.; Osthoff, H. D.

    2015-07-01

    Photochemical sources of peroxycarboxylic nitric anhydrides (PANs) are utilized in many atmospheric measurement techniques for calibration or to deliver an internal standard. Conventionally, such sources rely on phosphor-coated low-pressure mercury (Hg) lamps to generate the UV light necessary to photo-dissociate a dialkyl ketone (usually acetone) in the presence of a calibrated amount of nitric oxide (NO) and oxygen (O2). In this manuscript, a photochemical PAN source in which the Hg lamp has been replaced by arrays of ultraviolet light-emitting diodes (UV-LEDs) is described. The output of the UV-LED source was analyzed by gas chromatography (PAN-GC) and thermal dissociation cavity ring-down spectroscopy (TD-CRDS). Using acetone, diethyl ketone (DIEK), diisopropyl ketone (DIPK), or di-n-propyl ketone (DNPK), respectively, the source produces peroxyacetic (PAN), peroxypropionic (PPN), peroxyisobutanoic (PiBN), or peroxy-n-butanoic nitric anhydride (PnBN) from NO in high yield (> 90 %). Box model simulations with a subset of the Master Chemical Mechanism (MCM) were carried out to rationalize product yields and to identify side products. The present work demonstrates that UV-LED arrays are a viable alternative to current Hg lamp setups.

  1. Performance of a ruthenium beam separator used to separate soft x rays from light generated by a high-order harmonic light source.

    PubMed

    Ichimaru, Satoshi; Hatayama, Masatoshi; Ohchi, Tadayuki; Gullikson, Eric M; Oku, Satoshi

    2016-02-10

    We describe the design and fabrication of a ruthenium beam separator used to simultaneously attenuate infrared light and reflect soft x rays. Measurements in the infrared and soft x-ray regions showed the beam separator to have a reflectivity of 50%-85% in the wavelength region from 6 to 10 nm at a grazing incidence angle of 7.5 deg and 4.3% at 800 nm and the same angle of grazing incidence, indicating that the amount of attenuation is 0.05-0.09. These results show that this beam separator could provide an effective means for separating IR light from soft x rays in light generated by high-order harmonic generation sources.

  2. Humoral immunity and CD4+ Th1 cells are both necessary for a fully protective immune response upon secondary infection with Brucella melitensis.

    PubMed

    Vitry, Marie-Alice; Hanot Mambres, Delphine; De Trez, Carl; Akira, Shizuo; Ryffel, Bernhard; Letesson, Jean-Jacques; Muraille, Eric

    2014-04-15

    Brucella spp are intracellular bacteria that cause brucellosis, one of the most common zoonoses in the world. Given the serious medical consequences of this disease, a safe and effective human vaccine is urgently needed. Efforts to develop this vaccine have been hampered by our lack of understanding of what constitutes a protective memory response against Brucella. In this study, we characterize the cells and signaling pathways implicated in the generation of a protective immune memory response following priming by the injection of heat-killed or live Brucella melitensis 16M. Using a panel of gene-deficient mice, we demonstrated that during a secondary recall response, both the Brucella-specific humoral response and CD4+ Th1 cells must act together to confer protective immunity in the spleen to B. melitensis infection. Humoral protective immunity is induced by the inoculation of both heat-killed and live bacteria, and its development does not require T cells, MyD88/IL-12p35 signaling pathways, or an activation-induced deaminase-mediated isotype switch. In striking contrast, the presence of memory IFN-γ-producing CD4+ Th1 cells requires the administration of live bacteria and functional MyD88/IL-12p35 pathways. In summary, our work identifies several immune markers closely associated with protective immune memory and could help to define a rational strategy to obtain an effective human vaccine against brucellosis.

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

    PubMed

    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

  4. An enantioselective synthetic route toward second-generation light-driven rotary molecular motors.

    PubMed

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

    2010-02-05

    Controlling the unidirectional rotary process of second-generation 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 preparation of an optically active alpha-methoxy-substituted upper-half ketone involving an enzymatic resolution. The subsequent conversion of this ketone to the corresponding hydrazone by treatment with hydrazine led to full racemization. However, conversion to a TBDMS-protected hydrazone by treatment with bis-TBDMS hydrazine, prepared according to a new procedure, proceeds with nearly full retention of the stereochemical integrity. Oxidation of the TBDMS-protected hydrazone and subsequent coupling to a lower-half thioketone followed by recrystallization provided the molecular motors with >99% ee. As these are the first molecular motors that have a methoxy substituent at the stereogenic center, the photochemical and thermal isomerization steps involved in the rotary cycle of one of these new molecules were studied in detail with various spectroscopic techniques.

  5. Light

    NASA Astrophysics Data System (ADS)

    Vernon, C. G.

    2016-09-01

    Preface; 1. Historical; 2. Waves and wave-motion; 3. The behaviour of ripples; 4. The behaviour of light; 5. Refraction through glass blocks and prisms; 6. The imprinting of curvatures; 7. Simple mathematical treatment; 8. More advanced mathematical treatment; 9. The velocity of light; 10. The spectrum and colour; 11. Geometrical optics; 12. The eye and optical instruments; 13. Sources of light; 14. Interference, diffraction and polarisation; 15. Suggestions for class experiments; Index.

  6. The Ratio of 2nd to 4th Digit Length in Korean Alcohol-dependent Patients

    PubMed Central

    Han, Changwoo; Bae, Hwallip; Lee, Yu-Sang; Won, Sung-Doo; Kim, Dai Jin

    2016-01-01

    Objective The ratio of 2nd to 4th digit length (2D:4D) is a sexually dimorphic trait. Men have a relatively shorter second digit than fourth digit. This ratio is thought to be influenced by higher prenatal testosterone level or greater sensitivity to androgen. The purpose of this study is to investigate the relationship between alcohol dependence and 2D:4D in a Korean sample and whether 2D:4D can be a biologic marker in alcohol dependence. Methods In this study, we recruited 87 male patients with alcohol dependence from the alcohol center of one psychiatric hospital and 52 healthy male volunteers who were all employees in the same hospital as controls. We captured images of the right and left hands of patients and controls using a scanner and extracted data with a graphics program. We measured the 2D:4D of each hand and compared the alcohol dependence group with the control group. We analyzed these ratios using an independent-samples t-test. Results The mean 2D:4D of patients was 0.934 (right hand) and 0.942 (left hand), while the mean 2D:4D of controls was 0.956 (right hand) and 0.958 (left hand). Values for both hands were significantly lower for patients than controls (p<0.001, right hand; p=0.004, left hand). Conclusion Patients who are alcohol dependent have a significantly lower 2D:4D than controls, similar to the results of previous studies, which suggest that a higher prenatal testosterone level in the gonadal period is related to alcoholism. Furthermore, 2D:4D is a possible predictive marker of alcohol dependence. PMID:27121425

  7. PREFACE: 4th International Conference on: Preservation and Conservation Issues in Digital Printing and Digital Photography

    NASA Astrophysics Data System (ADS)

    Fricker, A.; Green, P.

    2010-04-01

    These conference proceedings contain the written papers of the contributions presented at the 4th International Conference on: Preservation and Conservation Issues in Digital Printing and Digital Photography. The conference was held at the Institute of Physics, London, UK on 27th-28th May 2010. Previous conferences in this series took place in 2000, 2003 and 2006. The aim of this conference series is to inform those responsible for the preservation of digitally printed materials about developments in digital photography and printing technologies. We aim to examine progress in research on inks and substrates and their significance for conservation and preservation issues and techniques. We also hope to develop links between related industries and the conservation/preservation world. Research areas explored in this conference include current developments and future trends in digital printing and photographic technologies; the effect of environmental, storage and salvage conditions on the durability of digital prints and photographs; image processing techniques; image permanence considerations and standards for fastness, permanence and the role of scanning and file formats. We would like to thank all participants for their contribution to the conference programme and these proceedings. Our thanks go to Ms C. Gu and Mr M. Sandy for chairing conference sessions. We are also grateful to Dawn Stewart and the Institute of Physics Conference Team for their invaluable support and assistance in arranging the conference and reception. Finally we would like to extend our thanks to the Society of Imaging Science and Technology (IS&T) for their sponsorship support. The Editors Acknowledgements Conference Organising Committee: Ms A Fricker and Dr. P Green (London College of Communication, University of the Arts London). Proceedings edited and compiled by Ms A Fricker and Dr. P Green.

  8. PREFACE: 4th International Workshop on Statistical Physics and Mathematics for Complex Systems (SPMCS)

    NASA Astrophysics Data System (ADS)

    Wang, Alexandre; Abe, Sumiyoshi; Li, Wei

    2015-04-01

    This volume contains 24 contributed papers presented at the 4th International Workshop on Statistical Physics and Mathematics for Complex Systems (SPMCS) held during October 12-16, 2014 in Yichang, China. Each paper was peer-reviewed by at least one referee chosen from a distinguished international panel. The previous three workshops of this series were organized in 2008, 2010, and 2012, in Le Mans, France, Wuhan, China, and Kazan, Russia, respectively. The SPMCS international workshop series is destined mainly to communicate and exchange research results and information on the fundamental challenges and questions in the vanguard of statistical physics, thermodynamics and mathematics for complex systems. More specifically, the topics of interest touch, but are not limited to, the following: • Fundamental aspects in the application of statistical physics and thermodynamics to complex systems and their modeling • Finite size and non-extensive system • Fluctuation theorems and equalities, quantum thermodynamics • Variational principle for random dynamics • Fractal geometry, fractional mathematics More than 50 participants from 7 countries participated in SPMCS-2014. 35 oral contributions were presented at the workshop. We would like to take this opportunity to thank the members of the Scientific Program Committee, many of whom acted as reviewers of the papers and responded promptly. We would also like to thank the organizing committee, the session chairs, the technicians and the students for the smooth running of the whole workshop. Thanks also go to China Three Gorges University who provided generous support for the conference venue, as well as exquisite refreshments for the tea breaks. The workshop was also partially supported by Central China Normal University and the Programme of Introducing Talents of Discipline to Universities under grant NO. B08033. Special thanks are due to Ms Juy Zhu who has done excellent editing work with great effort.

  9. Learning Natural Selection in 4th Grade with Multi-Agent-Based Computational Models

    NASA Astrophysics Data System (ADS)

    Dickes, Amanda Catherine; Sengupta, Pratim

    2013-06-01

    In this paper, we investigate how elementary school students develop multi-level explanations of population dynamics in a simple predator-prey ecosystem, through scaffolded interactions with a multi-agent-based computational model (MABM). The term "agent" in an MABM indicates individual computational objects or actors (e.g., cars), and these agents obey simple rules assigned or manipulated by the user (e.g., speeding up, slowing down, etc.). It is the interactions between these agents, based on the rules assigned by the user, that give rise to emergent, aggregate-level behavior (e.g., formation and movement of the traffic jam). Natural selection is such an emergent phenomenon, which has been shown to be challenging for novices (K16 students) to understand. Whereas prior research on learning evolutionary phenomena with MABMs has typically focused on high school students and beyond, we investigate how elementary students (4th graders) develop multi-level explanations of some introductory aspects of natural selection—species differentiation and population change—through scaffolded interactions with an MABM that simulates predator-prey dynamics in a simple birds-butterflies ecosystem. We conducted a semi-clinical interview based study with ten participants, in which we focused on the following: a) identifying the nature of learners' initial interpretations of salient events or elements of the represented phenomena, b) identifying the roles these interpretations play in the development of their multi-level explanations, and c) how attending to different levels of the relevant phenomena can make explicit different mechanisms to the learners. In addition, our analysis also shows that although there were differences between high- and low-performing students (in terms of being able to explain population-level behaviors) in the pre-test, these differences disappeared in the post-test.

  10. 4th International Conference on Energy and Environment 2013 (ICEE 2013)

    NASA Astrophysics Data System (ADS)

    Chakrabarty, Chandan Kumar; Shamsuddin, Abd Halim Bin; Ahmad, Ibrahim Bin; Desa, Mohamed Nor Bin Mohamed; Din, Norashidah Bte Md; Bte Mohd, Lariyah; Hamid, Nasri A.; See, Ong Hang; Hafiz Nagi, Farrukh; Yong, Lee Choon; Pasupuleti, Jagadeesh; Mei, Goh Su; Abdullah, Fairuz Bin; Satgunam, Meenaloshini

    2013-06-01

    The 4th International Conference on Energy & Environment 2013 (ICEE2013) was organized by the Universiti Tenaga Nasional (UNITEN) to provide a platform for creating and sharing ideas among engineers, researchers, scientists, industrialists and students in sustainable green energy and technologies. The theme 'Shaping a Sustainable Future through Advancement in Green Energy Technology' is in line with the University's vision to be a leading global energy university that shapes a sustainable future. The general scopes of the conference are renewable energy, smart grid, green technology, energy policies and economics, sustainable green energy and environment, sustainable education, international cooperation and innovation and technology transfer. Five international keynote speakers delivered their speeches in specialized areas of green energy technology and sustainability. In addition, the conference highlights several special parallel sessions by notable invited presenters in their niche areas, which are: Hybrid Energy Power Quality & Distributed Energy Smart Grid Nuclear Power & Technologies Geohazard Management Greener Environment for Sustainability Advances in Computational Fluid Dynamics The research papers presented in ICEE2013 are included in this volume of IOP Conference Series: Earth and Environmental Science (EES). EES is abstracted and indexed in SCOPUS, GeoBase, GeoRef, Compendex, Inspec, Chemical Abstracts Service, NASA Astrophysics Data System, and International Nuclear Information System (INIS). With the comprehensive programme outline, the organizing committee hopes that the ICEE2013 was a notable intellectual sharing session for the research and academic community in Malaysia and regionally. The organizing committee expresses gratitude to the ICEE2013 delegates for their great support and contributions to the event.

  11. PREFACE: CYGNUS 2013: 4th Workshop on Directional Detection of Dark Matter

    NASA Astrophysics Data System (ADS)

    Naka, Tatsuhiro; Miuchi, Kentaro

    2013-12-01

    It is a great pleasure to publish the proceedings of the 4th Workshop on Directional Detection of Dark Matter held in Toyama, Japan on 10-12 June 2013 (CYGNUS 2013). These proceedings contain written versions of the presentations made at CYGNUS 2013 as scientific outputs of the directional detection of dark matter. The GYGNUS workshop started in 2007 at Boulby Underground Laboratory (UK), followed by CYGNUS 2009 (MIT in Cambridge, Massachusetts, USA) and CYGNUS 2011 (AUSSOIS, France). CYGNUS 2013 was held by the combination of a two and a half days of scientific program and a half day visit to the underground laboratory (Kamioka Observatory) as a 'tradition' of CYGNUS workshops. The name 'CYGNUS' came from the fact that the 'dark matter wind' is expected to come from the direction of the constellation Cygnus due to the motion of the Solar system in the galaxy. A general aim of these CYGNUS workshops is to bring together the theoretical and experimental studies on the directional dark matter detection. Directional detection of dark matter is a promising approach to a 'clear detection' and also to 'further investigations' of galactic dark matter, or Weakly Interacting Massive Particles (WIMPs). Directional detection requires the simultaneous detection of the energy and track of low energy recoils. Among many technological challenges for the requirement above, three of them, namely size, background, and directionality (angular resolution and head-tail detection), are most important to demonstrate and improve the quality as a dark matter detector. In the workshop, up-to-date activities by the international reserchers are discussed. The workshop was a great success thanks to the oral contributions and fruitful discussions held throughout the workshop period. We hope that readers will remember and share the great enthusiasm shown during the CYGNUS 2013 workshop. The Editors Tatsuhiro Naka and Kentaro Miuchi

  12. European Code against Cancer 4th Edition: Environment, occupation and cancer.

    PubMed

    Espina, Carolina; Straif, Kurt; Friis, Søren; Kogevinas, Manolis; Saracci, Rodolfo; Vainio, Harri; Schüz, Joachim

    2015-12-01

    People are exposed throughout life to a wide range of environmental and occupational pollutants from different sources at home, in the workplace or in the general environment - exposures that normally cannot be directly controlled by the individual. Several chemicals, metals, dusts, fibres, and occupations have been established to be causally associated with an increased risk of specific cancers, such as cancers of the lung, skin and urinary bladder, and mesothelioma. Significant amounts of air pollutants - mainly from road transport and industry - continue to be emitted in the European Union (EU); an increased occurrence of lung cancer has been attributed to air pollution even in areas below the EU limits for daily air pollution. Additionally, a wide range of pesticides as well as industrial and household chemicals may lead to widespread human exposure, mainly through food and water. For most environmental pollutants, the most effective measures are regulations and community actions aimed at reducing and eliminating the exposures. Thus, it is imperative to raise awareness about environmental and occupational carcinogens in order to motivate individuals to be proactive in advocating protection and supporting initiatives aimed at reducing pollution. Regulations are not homogeneous across EU countries, and protective measures in the workplace are not used consistently by all workers all the time; compliance with regulations needs to be continuously monitored and enforced. Therefore, the recommendation on Environment and Occupation of the 4th edition of the European Code against Cancer, focusing on what individuals can do to reduce their cancer risk, reads: "In the workplace, protect yourself against cancer-causing substances by following health and safety instructions."

  13. 75 FR 34369 - Safety Zones; City of Chicago's July 4th Celebration Fireworks, Lake Michigan, Chicago, IL

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-17

    ... SECURITY Coast Guard 33 CFR Part 165 RIN 1625-AA00 Safety Zones; City of Chicago's July 4th Celebration Fireworks, Lake Michigan, Chicago, IL AGENCY: Coast Guard, DHS. ACTION: Temporary final rule. SUMMARY: The Coast Guard is establishing two temporary safety zones on Lake Michigan near Chicago, Illinois....

  14. 75 FR 22330 - Safety Zone; City of Chicago's July 4th Celebration Fireworks, Lake Michigan, Chicago, IL

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-04-28

    ... SECURITY Coast Guard 33 CFR Part 165 RIN 1625-AA00 Safety Zone; City of Chicago's July 4th Celebration Fireworks, Lake Michigan, Chicago, IL AGENCY: Coast Guard, DHS. ACTION: Notice of proposed rulemaking. SUMMARY: The Coast Guard proposes to establish a safety zone on Lake Michigan near Chicago, Illinois....

  15. Communicating Science to Impact Learning? A Phenomenological Inquiry into 4th and 5th Graders' Perceptions of Science Information Sources

    ERIC Educational Resources Information Center

    Gelmez Burakgazi, Sevinc; Yildirim, Ali; Weeth Feinstein, Noah

    2016-01-01

    Rooted in science education and science communication studies, this study examines 4th and 5th grade students' perceptions of science information sources (SIS) and their use in communicating science to students. It combines situated learning theory with uses and gratifications theory in a qualitative phenomenological analysis. Data were gathered…

  16. Examining General and Specific Factors in the Dimensionality of Oral Language and Reading in 4th-10th Grades

    ERIC Educational Resources Information Center

    Foorman, Barbara R.; Koon, Sharon; Petscher, Yaacov; Mitchell, Alison; Truckenmiller, Adrea

    2015-01-01

    The objective of this study was to explore dimensions of oral language and reading and their influence on reading comprehension in a relatively understudied population--adolescent readers in 4th through 10th grades. The current study employed latent variable modeling of decoding fluency, vocabulary, syntax, and reading comprehension so as to…

  17. Comparative analysis of 1st, 2nd, and 4th year MD students' attitudes toward Complementary Alternative Medicine (CAM)

    PubMed Central

    Riccard, Christopher P; Skelton, Michele

    2008-01-01

    Background To identify and report the attitudes and beliefs of 1st, 2nd, and 4th year medical students toward complementary alternative medicine (CAM). Methods The previously validated and reliability tested CHBQ was administered to medical students attending the University of South Florida School of Medicine. Results Significant changes were found between both 1st (46.0 ± 7.7) and 4th (37.8 ± 15.7) year students and 2nd (48.3 ± 7.8) and 4th (37.8 ± 15.7) year students. No significant difference was found between 1st (46.0 ± 7.7) and 2nd (48.3 ± 7.8) year students. When comparing scores based on gender, a significant difference was present between males (41.2 ± 12.2) and females (46.1 ± 11.0). Conclusion CHBQ scores were significantly more positive in both 1st and 2nd year medical students in comparison with 4th year student's scores. These findings suggest that as student exposure to allopathic techniques and procedures increases during the last year of medical school, their attitudes toward CAM decrease. Females were also significantly more likely to have stronger positive attitudes toward CAM than males, though both genders represented an overall positive attitude toward CAM. PMID:18799010

  18. 75 FR 34379 - Safety Zone; Mackinac Island 4th of July Fireworks, Lake Huron, Mackinac Island, MI

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-17

    ... SECURITY Coast Guard 33 CFR Part 165 RIN 1625-AA00 Safety Zone; Mackinac Island 4th of July Fireworks, Lake Huron, Mackinac Island, MI AGENCY: Coast Guard, DHS. ACTION: Temporary final rule. SUMMARY: The Coast Guard is establishing a temporary safety zone on Lake Huron, Mackinac Island, Michigan. This zone...

  19. Proceedings of the International Conference on Educational Data Mining (EDM) (4th, Eindhoven, the Netherlands, July 6-8, 2011)

    ERIC Educational Resources Information Center

    Pechenizkiy, Mykola; Calders, Toon; Conati, Cristina; Ventura, Sebastian; Romero, Cristobal; Stamper, John

    2011-01-01

    The 4th International Conference on Educational Data Mining (EDM 2011) brings together researchers from computer science, education, psychology, psychometrics, and statistics to analyze large datasets to answer educational research questions. The conference, held in Eindhoven, The Netherlands, July 6-9, 2011, follows the three previous editions…

  20. Using Inquiry-Based Instruction to Teach Research Methods to 4th-Grade Students in an Urban Setting

    ERIC Educational Resources Information Center

    Hamm, Ellen M.; Cullen, Rebecca; Ciaravino, Melissa

    2013-01-01

    When a college professor who teaches research methods to graduate education students was approached by a local public urban elementary school to help them teach research skills to 4th-graders, it was thought that the process would be simple--take what we did at the college level and differentiate it for the childhood classroom. This article will…

  1. Native American Students' Understanding of Geologic Time Scale: 4th-8th Grade Ojibwe Students' Understanding of Earth's Geologic History

    ERIC Educational Resources Information Center

    Nam, Younkyeong; Karahan, Engin; Roehrig, Gillian

    2016-01-01

    Geologic time scale is a very important concept for understanding long-term earth system events such as climate change. This study examines forty-three 4th-8th grade Native American--particularly Ojibwe tribe--students' understanding of relative ordering and absolute time of Earth's significant geological and biological events. This study also…

  2. 77 FR 39422 - Eighth Coast Guard District Annual Safety Zones; Niceville July 4th Fireworks Show; Boggy Bayou...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-03

    ... SECURITY Coast Guard 33 CFR Part 165 RIN 1625-AA00 Eighth Coast Guard District Annual Safety Zones; Niceville July 4th Fireworks Show; Boggy Bayou; Niceville, FL AGENCY: Coast Guard, DHS. ACTION: Notice of enforcement of regulation. SUMMARY: The Coast Guard will enforce a Safety Zone for the Niceville July...

  3. Impact of a Health and Media Literacy Curriculum on 4th-Grade Girls: A Qualitative Study

    ERIC Educational Resources Information Center

    Fuller, Heidi A.; Damico, Amy M.; Rodgers, Shannon

    2004-01-01

    Recent research indicates that young girls are preoccupied with their body size and that the media may be a contributing factor. This study aimed to discover the impact of an interdisciplinary media literacy intervention curriculum on 4th-grade girls in an urban elementary school. The authors developed and implemented a series of lessons that…

  4. Analysis of Lexical Quality and Its Relation to Writing Quality for 4th Grade, Primary School Students in Chile

    ERIC Educational Resources Information Center

    Gómez Vera, Gabriela; Sotomayor, Carmen; Bedwell, Percy; Domínguez, Ana María; Jéldrez, Elvira

    2016-01-01

    Few studies have addressed vocabulary quality in developing writing skill in Spanish. Even less addressed it within the Chilean educational system. The specific objective of this study was to characterize, using a comprehensive set of indicators, the quality of the vocabulary produced by Chilean 4th grade students. Based on a national writing…

  5. Teacher Implementation of Reform-Based Mathematics and Implications for Algebra Readiness: A Qualitative Study of 4th Grade Classrooms

    ERIC Educational Resources Information Center

    Sher, Stephen Korb

    2011-01-01

    This study looked at 4th grade classrooms to see "how" teachers implement NCTM standards-based or reform-based mathematics instruction and then analyzed it for the capacity to improve students' "algebra readiness." The qualitative study was based on classroom observations, teacher and administrator interviews, and teacher surveys. The study took…

  6. Hydrogen peroxide generated by NADPH oxidase is involved in high blue-light-induced chloroplast avoidance movements in Arabidopsis

    NASA Astrophysics Data System (ADS)

    Wen, Feng; Xing, Da; Zhang, Lingrui

    2009-08-01

    One of the most important functions of blue light is to induce chloroplast movements by reducing the damage to photosynthetic machinery under excess light. Hydrogen peroxide (H2O2), generated by various environmental stimuli, can act as a signaling molecule that regulates a number of developmental processes and environmental responses. To investigate whether H2O2 is involved in high blue light-induced chloroplast avoidance movements, we use luminescence spectrometer to observe H2O2 generation with the assistance of the fluorescence probe dichlorofluorescin diacetate (H2DCF-DA). After treatment with high blue light, a large quantity of H2O2 indicated by the fluorescence intensity of DCF is produced in a dose-dependent manner in leaf strip of Arabidopsis. Enzymatic assay shows that the activity of NADPH oxidase, which is a major site for H2O2 generation, also rapidly increases in treated strips. Exogenously applied H2O2 can promote the high blue light-induced chloroplast movements. Moreover, high blue light-induced H2O2 generation can be abolished completely by addition of exogenous catalase (CAT), and partly by diphenylene iodonium (DPI) and dichlorophenyl dimethylurea (DCMU), which are an NADPH oxidase inhibitor and a blocker of electron transport chain. And subsequent chloroplast movements can be abolished by CAT and DPI, but not by DCMU. These results presented here suggested that high blue light can induce oxidative burst, and NADPH oxidase as a major producer for H2O2 is involved in blue light-induced chloroplast avoidance movements.

  7. Light Harvesting and White-Light Generation in a Composite of Carbon Dots and Dye-Encapsulated BSA-Protein-Capped Gold Nanoclusters.

    PubMed

    Barman, Monoj Kumar; Paramanik, Bipattaran; Bain, Dipankar; Patra, Amitava

    2016-08-08

    Several strategies have been adopted to design an artificial light-harvesting system in which light energy is captured by peripheral chromophores and it is subsequently transferred to the core via energy transfer. A composite of carbon dots and dye-encapsulated BSA-protein-capped gold nanoclusters (AuNCs) has been developed for efficient light harvesting and white light generation. Carbon dots (C-dots) act as donor and AuNCs capped with BSA protein act as acceptor. Analysis reveals that energy transfer increases from 63 % to 83 % in presence of coumarin dye (C153), which enhances the cascade energy transfer from carbon dots to AuNCs. Bright white light emission with a quantum yield of 19 % under the 375 nm excitation wavelength is achieved by changing the ratio of components. Interesting findings reveal that the efficient energy transfer in carbon-dot-metal-cluster nanocomposites may open up new possibilities in designing artificial light harvesting systems for future applications.

  8. Interaction between hollow needles - electric field, light emission and ozone generation study in multineedle to plate electrical discharge

    NASA Astrophysics Data System (ADS)

    Kriha, Vitezslav

    2004-09-01

    Multi hollow needle to plate electrical discharges in air are studied as ozone sources. Dependence of ozone concentration as an function of applied voltage, discharge current, mutual hollow needles position and electrical connection, working gas flow rate, distances between needles tips and plate electrode, visible light emission was measured experimentally in these systems. Electric field was numerically modeled. Light emission and electrical field distributions were compared. Coming from light emission and electric field a model of energy density spatial distribution was built. This model was finally compared with ozone generation.

  9. Optimum projection pattern generation for grey-level coded structured light illumination systems

    NASA Astrophysics Data System (ADS)

    Porras-Aguilar, Rosario; Falaggis, Konstantinos; Ramos-Garcia, Ruben

    2017-04-01

    Structured light illumination (SLI) systems are well-established optical inspection techniques for noncontact 3D surface measurements. A common technique is multi-frequency sinusoidal SLI that obtains the phase map at various fringe periods in order to estimate the absolute phase, and hence, the 3D surface information. Nevertheless, multi-frequency SLI systems employ multiple measurement planes (e.g. four phase shifted frames) to obtain the phase at a given fringe period. It is therefore an age old challenge to obtain the absolute surface information using fewer measurement frames. Grey level (GL) coding techniques have been developed as an attempt to reduce the number of planes needed, because a spatio-temporal GL sequence employing p discrete grey-levels and m frames has the potential to unwrap up to pm fringes. Nevertheless, one major disadvantage of GL based SLI techniques is that there are often errors near the border of each stripe, because an ideal stepwise intensity change cannot be measured. If the step-change in intensity is a single discrete grey-level unit, this problem can usually be overcome by applying an appropriate threshold. However, severe errors occur if the intensity change at the border of the stripe exceeds several discrete grey-level units. In this work, an optimum GL based technique is presented that generates a series of projection patterns with a minimal gradient in the intensity. It is shown that when using this technique, the errors near the border of the stripes can be significantly reduced. This improvement is achieved with the choice generated patterns, and does not involve additional hardware or special post-processing techniques. The performance of that method is validated using both simulations and experiments. The reported technique is generic, works with an arbitrary number of frames, and can employ an arbitrary number of grey-levels.

  10. CarF Mediates Signaling by Singlet Oxygen, Generated via Photoexcited Protoporphyrin IX, in Myxococcus xanthus Light-Induced Carotenogenesis

    PubMed Central

    Galbis-Martínez, Marisa; Padmanabhan, S.; Murillo, Francisco J.

    2012-01-01

    Blue light triggers carotenogenesis in the nonphototrophic bacterium Myxococcus xanthus by inducing inactivation of an anti-σ factor, CarR, and the consequent liberation of the cognate extracytoplasmic function (ECF) σ factor, CarQ. CarF, the protein implicated earliest in the response to light, does not resemble any known photoreceptor. It interacts physically with CarR and is required for its light-driven inactivation, but the mechanism is unknown. Blue-light sensing in M. xanthus has been attributed to the heme precursor protoporphyrin IX (PPIX), which can generate the highly reactive singlet oxygen species (1O2) by energy transfer to oxygen. However, 1O2 involvement in M. xanthus light-induced carotenogenesis remains to be established. Here, we present genetic evidence of the involvement of PPIX as well as 1O2 in light-induced carotenogenesis in M. xanthus and of how these are linked to CarF in the signal transduction pathway. Response to light was examined in carF-bearing and carF-deficient M. xanthus strains lacking endogenous PPIX due to deletion of hemB or accumulating PPIX due to deletion of hemH (hemB and hemH are early- and late-acting heme biosynthesis genes, respectively). This demonstrated that light induction of the CarQ-dependent promoter, PQRS, correlated directly with cellular PPIX levels. Furthermore, we show that PQRS activation is triggered by 1O2 and is inhibited by exogenously supplied hemin and that CarF is essential for the action of 1O2. Thus, our findings indicate that blue light interaction with PPIX generates 1O2, which must be transmitted via CarF to trigger the transcriptional response underlying light-induced carotenogenesis in M. xanthus. PMID:22267513

  11. 4th Rare Disease South Eastern Europe (See) Meeting Skopje, Macedonia (November 14th, 2015).

    PubMed

    Gucev, Zoran; Tasic, Velibor; Polenakovic, Momir

    2015-01-01

    The 4th meeting on rare diseases in South Eastern Europe (SEE) was held in Skopje, at the Macedonian Academy of Sciences and Arts (MASA) on the 14(th) of November 2015. The focuses were metabolic, rare brain diseases as well as the rare dysmorphic syndrome. The authors of the report are particularly keen on stating that one of the main goals of the meeting, namely to help the treatment of patients with rare disease has begun to bear fruits. The talk on an iminosugar-based pharmacological chaperone compound as a drug candidate for the treatment of GM1-gangliosidosis and mucopolysaccharidosis IVB (Morquio disease type B) was enlightening. To date, there is no treatment available to be offered to patients, but chaperones lead mutated proteins to adopt a native-like conformation and to successfully traffic to their normal cellular destination. DORPHAN is developing an iminosugar-based pharmacological chaperone compound for the treatment of GM1-gangliosidosis and mucopolysaccharidosis IVB. A talk on recent developments in the laboratory diagnosis of mucopolysaccharidoses (MPS) was particularly interesting, covering the laboratory diagnosis of the MPS diseases by a strategy of clinical examination, biochemical analysis of urine samples, enzyme tests and genetic characterization of underlying mutations. New techniques were developed, including analysis of urinary glycosaminoglycans with tandem mass spectrometry, miniaturized enzyme tests or novel synthetic substrates for enzyme assays using mass spectrometry detection of products using dried blood spots. Feasibility and cost-effectiveness of these methods in newborn screening programs have been demonstrated. Neuromuscular RDs, and especially familial amyloid polyneuropathy (FAP) were a topic of the Bulgarian colleagues. Diagnosis, screening and the role of microglia were also topics of particular interest. In summary, this year RD meeting was exciting and productive on a wide range of diseases and on a novel insights on

  12. PREFACE: 4th Global Conference on Materials Science and Engineering (CMSE 2015)

    NASA Astrophysics Data System (ADS)

    Ruda, H. E.; Khotsianovsky, A.

    2015-12-01

    IOP Conference Series: Materials Science and Engineering is publishing a volume of conference proceedings that contains a selection of papers presented at the 4th Global Conference on Materials Science and Engineering (CMSE 2015), which is an annual event that started in 2012. CMSE 2015, technically supported by the Institute of Applied Physics and Materials Engineering of University of Macau, organized by Wuhan Advance Materials Society, was successfully held at the University of Macau-new campus located on Hengqin Island from August 3rd-6th, 2015. It aims to bring together leading academic scientists, researchers and scholars to exchange and share their experience and research results on all aspects of Materials Science and Engineering, and to discuss the practical challenges encountered and the solutions adopted. Macau, one of the two special administrative regions of the People's Republic of China, where East meets West, turned out to be an ideal meeting place for domestic and overseas participants of this annual international conference. The conference program included keynote presentations, special sessions, oral and poster contributions. From several hundred submissions, 52 of the most promising and mainstream, IOP-relevant, contributions were included in this volume. The submissions present original ideas or results of general significance, supported by clear reasoning, compelling evidence and methods, theories and practices relevant to the research. The authors state clearly the problems and the significance of their research to theory and practice. Being a successful conference, this event gathered more than 200 qualified and high-level researchers and experts from over 40 countries, including 10 keynote speakers from 6 countries, which created a good platform for worldwide researchers and engineers to enjoy the academic communication. Taking advantage of this opportunity, we would like to thank all participants of this conference, and particularly the

  13. The Effect of Primer Application Modifications on the Bond Strength of 4th Generation Adhesive Bonding Agents

    DTIC Science & Technology

    2012-03-30

    dentin. Methods: The coronal enamel of 120 extracted human third molars was removed with a low-speed saw. The teeth were mounted in PVC pipe with dental...LITERATURE REVIEW A. Background 1. Acid Etching in Dentistry. Buonocore demonstrated in 1955 that the preparation of dental enamel with an...The influence of deviations from the manufacturer’s instructions for the use of six adhesive systems on the bond strengths to enamel and dentin

  14. Computational Fluid Dynamics (CFD) study of the 4th generation prototype of a continuous flow Ventricular Assist Device (VAD).

    PubMed

    Song, Xinwei; Wood, Houston G; Olsen, Don

    2004-04-01

    The continuous flow ventricular assist device (VAD) is a miniature centrifugal pump, fully suspended by magnetic bearings, which is being developed for implantation in humans. The CF4 model is the first actual prototype of the final design product. The overall performances of blood flow in CF4 have been simulated using computational fluid dynamics (CFD) software: CFX, which is commercially available from ANSYS Inc. The flow regions modeled in CF4 include the inlet elbow, the five-blade impeller, the clearance gap below the impeller, and the exit volute. According to different needs from patients, a wide range of flow rates and revolutions per minute (RPM) have been studied. The flow rate-pressure curves are given. The streamlines in the flow field are drawn to detect stagnation points and vortices that could lead to thrombosis. The stress is calculated in the fluid field to estimate potential hemolysis. The stress is elevated to the decreased size of the blood flow paths through the smaller pump, but is still within the safe range. The thermal study on the pump, the blood and the surrounding tissue shows the temperature rise due to magnetoelectric heat sources and thermal dissipation is insignificant. CFD simulation proved valuable to demonstrate and to improve the performance of fluid flow in the design of a small size pump.

  15. Synthesis of fluorescent core-shell nanomaterials and strategies to generate white light

    SciTech Connect

    Singh, Amandeep; Kaur, Ramanjot; Pandey, O. P.; Wei, Xueyong; Sharma, Manoj E-mail: manojsharma@bilkent.edu.tr

    2015-07-28

    In this work, cadmium free core-shell ZnS:X/ZnS (X = Mn, Cu) nanoparticles have been synthesized and used for white light generation. First, the doping concentration of Manganese (Mn) was varied from 1% to 4% to optimize the dopant related emission and its optimal value was found to be 1%. Then, ZnS shell was grown over ZnS:Mn(1%) core to passivate the surface defects. Similarly, the optimal concentration of Copper (Cu) was found to be 0.8% in the range varied from 0.6% to 1.2%. In order to obtain an emission in the whole visible spectrum, dual doping of Mn and Cu was done in the core and the shell, respectively. A solid-solid mixing in different ratios of separately doped quantum dots (QDs) emitting in the blue green and the orange region was performed. Results show that the optimum mixture of QDs excited at 300 nm gives Commission Internationale del'Éclairage color coordinates of (0.35, 0.36), high color rendering index of 88, and correlated color temperature of 4704 K with minimum self-absorption.

  16. Magnetic field enhancement of generation-recombination and shot noise in organic light emitting diodes

    SciTech Connect

    Djidjou, T. K.; Basel, Tek; Rogachev, A.; Chen, Ying; Shinar, J.

    2015-03-21

    We have studied the effect of magnetic field on noise in series of 2-methoxy-5-(2′-ethylhexyloxy)-1,4-phenylenevinylene-based organic light emitting diodes with dominant hole injection, dominant electron injection, and balanced electron and hole injection. The noise spectra of the balanced devices revealed the generation-recombination (g-r) noise term, which we associated with bimolecular electron-hole recombination. The presence of the g-r noise term is correlated with the strong organic magnetoresistance (up to 25%) observed in the balanced devices. The noise spectra also have the shot noise contribution with the Fano factor 0.25–0.4. We found that time constant of the g-r term decreases and the magnitude of shot noise increases when magnetic field is applied. This behavior can be consistently explained within the polaron-polaron model of organic magnetoresistance. We have not found any evidence that the magnetoresistance in studied devices is affected by traps.

  17. Dynamic Stark effect, light emission, and entanglement generation in a laser-driven quantum optical system

    NASA Astrophysics Data System (ADS)

    Pagel, D.; Alvermann, A.; Fehske, H.

    2017-01-01

    We calculate the emission spectra, the Glauber g(2 ) function, and the entanglement of formation for two-level emitters coupled to a single cavity mode and subject to an external laser excitation. To evaluate these quantities we couple the system to environmental degrees of freedom, which leads to dissipative dynamics. Because of the periodic time dependence of the system Hamiltonian, the coefficients of the Markovian master equation are constant only if Floquet states are used as the computational basis. Studying the emission spectra, we show that the dynamic Stark effect first appears in second order of the laser intensity. For the Glauber function, we find clearly distinguished parameter regimes of super- and sub-Poissonian light emission and explain the additional features appearing for finite laser intensity in terms of the quasienergy spectrum of the driven emitter-cavity system. Finally, we analyze the temperature and emitter-cavity-coupling regimes where entanglement among the emitters is generated and show that the laser excitation leads to a decrease of entanglement.

  18. Generation of dark hollow femtosecond pulsed beam by phase-only liquid crystal spatial light modulator.

    PubMed

    Nie, Yongming; Ma, Haotong; Li, Xiujian; Hu, Wenhua; Yang, Jiankun

    2011-07-20

    Based on the refractive laser beam shaping system, the dark hollow femtosecond pulse beam shaping technique with a phase-only liquid crystal spatial light modulator (LC-SLM) is demonstrated. The phase distribution of the LC-SLM is derived by the energy conservation and constant optical path principle. The effects of the shaping system on the temporal properties, including spectral phase distribution and bandwidth of the femtosecond pulse, are analyzed in detail. Experimental results show that the hollow intensity distribution of the output pulsed beam can be maintained much at more than 1200 mm. The spectral phase of the pulse is changed, and the pulse width is expanded from 199 to 230 fs, which is caused by the spatial-temporal coupling effect. The coupling effect mainly depends on the phase-only LC-SLM itself, not on its loaded phase distribution. The experimental results indicate that the proposed shaping setup can generate a dark hollow femtosecond pulsed beam effectively, because the temporal Gaussian waveform is unchanged.

  19. Generation of 3-D surface maps in waste storage silos using a structured light source

    NASA Technical Reports Server (NTRS)

    Burks, B. L.; Rowe, J. C.; Dinkins, M. A.; Christensen, B.; Selleck, C.; Jacoboski, D.; Markus, R.

    1992-01-01

    Surface contours inside the large waste storage tanks typical of the Department of Energy (DOE) complex are, in general, highly irregular. In addition to pipes and other pieces of equipment in the tanks, the surfaces may have features such as mounds, fissures, crystalline structures, and mixed solid and liquid forms. Prior to remediation activities, it will be necessary to characterize the waste to determine the most effective remediation approaches. Surface contour data will be required both prior to and during remediation. The use is described of a structured light source to generate 3-D surface contour maps of the interior of waste storage silos at the Feed Materials Production Center at Fernald, OH. The landscape inside these large waste storage tanks bears a strong resemblance to some of the landscapes that might be encountered during lunar or planetary exploration. Hence, these terrestrial 3-D mapping techniques may be directly applicable to extraterrestrial exploration. In further development, it will be demonstrated that these 3-D data can be used for robotic task planning just as 3-D surface contour data of a satellite could be used to plan maintenance tasks for a space-based servicing robot.

  20. Synthesis of fluorescent core-shell nanomaterials and strategies to generate white light

    NASA Astrophysics Data System (ADS)

    Singh, Amandeep; Kaur, Ramanjot; Pandey, O. P.; Wei, Xueyong; Sharma, Manoj

    2015-07-01

    In this work, cadmium free core-shell ZnS:X/ZnS (X = Mn, Cu) nanoparticles have been synthesized and used for white light generation. First, the doping concentration of Manganese (Mn) was varied from 1% to 4% to optimize the dopant related emission and its optimal value was found to be 1%. Then, ZnS shell was grown over ZnS:Mn(1%) core to passivate the surface defects. Similarly, the optimal concentration of Copper (Cu) was found to be 0.8% in the range varied from 0.6% to 1.2%. In order to obtain an emission in the whole visible spectrum, dual doping of Mn and Cu was done in the core and the shell, respectively. A solid-solid mixing in different ratios of separately doped quantum dots (QDs) emitting in the blue green and the orange region was performed. Results show that the optimum mixture of QDs excited at 300 nm gives Commission Internationale del'Éclairage color coordinates of (0.35, 0.36), high color rendering index of 88, and correlated color temperature of 4704 K with minimum self-absorption.

  1. Method to generate high efficient devices which emit high quality light for illumination

    DOEpatents

    Krummacher, Benjamin C.; Mathai, Mathew; Choong, Vi-En; Choulis, Stelios A.

    2009-06-30

    An electroluminescent apparatus includes an OLED device emitting light in the blue and green spectrums, and at least one down conversion layer. The down conversion layer absorbs at least part of the green spectrum light and emits light in at least one of the orange spectra and red spectra.

  2. Proceedings of the Biennial EO/EEO Research Symposium (4th) Held in Cocoa Beach, Florida on December 5-7, 2001

    DTIC Science & Technology

    2003-01-01

    PROCEEDINGS 4th Biennial EO/EEO Research Symposium December 5-7, 2001 Cocoa Beach, Florida Published January 2003 DEOMI Research Report 03-01...distribution unlimited 13. SUPPLEMENTARY NOTES Proceedings 4th Biennial EO/EEO Research Symposium, Held in Cocoa Beach, Florida on December 5-7...Prescribed by ANSI Std Z39-18 ii Proceedings 4th Biennial EO/EEO Research Symposium December 5-7, 2001 Cocoa Beach, Florida Sponsored

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

    SciTech Connect

    Chen, Li -Jin

    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

  4. A Bifunctional Photosensitizer for Enhanced Fractional Photodynamic Therapy: Singlet Oxygen Generation in the Presence and Absence of Light.

    PubMed

    Turan, Ilke Simsek; Yildiz, Deniz; Turksoy, Abdurrahman; Gunaydin, Gurcan; Akkaya, Engin U

    2016-02-18

    The photosensitized generation of singlet oxygen within tumor tissues during photodynamic therapy (PDT) is self-limiting, as the already low oxygen concentrations within tumors is further diminished during the process. In certain applications, to minimize photoinduced hypoxia the light is introduced intermittently (fractional PDT) to allow time for the replenishment of cellular oxygen. This condition extends the time required for effective therapy. Herein, we demonstrated that a photosensitizer with an additional 2-pyridone module for trapping singlet oxygen would be useful in fractional PDT. Thus, in the light cycle, the endoperoxide of 2-pyridone is generated along with singlet oxygen. In the dark cycle, the endoperoxide undergoes thermal cycloreversion to produce singlet oxygen, regenerating the 2-pyridone module. As a result, the photodynamic process can continue in the dark as well as in the light cycles. Cell-culture studies validated this working principle in vitro.

  5. 1.5 W green light generation by single-pass second harmonic generation of a single-frequency tapered diode laser.

    PubMed

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

    2009-04-13

    More than 1.5 W of green light at 531 nm is generated by single-pass second harmonic generation in periodically poled MgO:LiNbO3. The pump laser is a high power tapered laser with a distributed Bragg reflector etched in the ridge section of the laser to provide wavelength selectivity. The output power of the single-frequency tapered laser is 9.3 W in continuous wave operation. A conversion efficiency of 18.5 % was achieved in the experiments.

  6. STO-2: Support for 4th Year Operations, Recovery, and Science (JPL co-I)

    NASA Astrophysics Data System (ADS)

    Kawamura, Jonathan

    Here we propose "STO-2: Support for 4th Year Operations, Recovery, and Science," a project being led by Dr. Christopher Walker of the University of Arizona. The Stratospheric TeraHertz Observatory was ready for its second Antarctic flight (STO-2) in the 2015-2016 austral summer. However, due to the late establishment of the stratospheric anti-cyclone and poor surface conditions, STO-2 was unable to launch. The decision was made to winter-over the STO-2 payload in its hangar for launch during the 2016-2017 Antarctic campaign. Funds to cover preparations and deployment of key members of the instrument team in support of the campaign are being provided by NASA under the existing grant. However, these funds are only sufficient to cover expenses up to December 31st, 2016. Here, we request resources for calendar year 2017 to support mission operations, payload recovery, and science operations. These elements will enable the team to deliver fully on STO-2's science mission, and maximize NASA's demonstrated investment in STO-2's success. STO-2 addresses a key problem in modern astrophysics: understanding the Life Cycle of the Interstellar Medium (ISM). STO-2 will survey approximately ˜ of the Southern Galactic Plane in the dominant interstellar cooling line [CII] (158 μm) and the important star formation tracer [NII] (205 μm). In addition, STO-2 will perform path finding observations of the 63 μm [OI] line toward selected regions. With 1 arcminute angular resolution, STO-2 will spatially resolve atomic, ionic and molecular clouds out to 10 kpc. The STO-2 survey will be conducted at unparalleled sensitivity levels. STO-2 will uniquely probe the pivotal formative and disruptive stages in the life cycle of interstellar clouds and the relationship between global star formation rates and the properties of the ISM. Combined with previous HI and CO surveys, STO-2 will create 3- dimensional maps of the structure, dynamics, turbulence, energy balance, and pressure of the Milky

  7. PREFACE: 4th Workshop on Theory, Modelling and Computational Methods for Semiconductors (TMCSIV)

    NASA Astrophysics Data System (ADS)

    Tomić, Stanko; Probert, Matt; Migliorato, Max; Pal, Joydeep

    2014-06-01

    These conference proceedings contain the written papers of the contributions presented at the 4th International Conference on Theory, Modelling and Computational Methods for Semiconductor materials and nanostructures. The conference was held at the MediaCityUK, University of Salford, Manchester, UK on 22-24 January 2014. The previous conferences in this series took place in 2012 at the University of Leeds, in 2010 at St William's College, York and in 2008 at the University of Manchester, UK. The development of high-performance computer architectures is finally allowing the routine use of accurate methods for calculating the structural, thermodynamic, vibrational, optical and electronic properties of semiconductors and their hetero- and nano-structures. The scope of this conference embraces modelling, theory and the use of sophisticated computational tools in semiconductor science and technology, where there is substantial potential for time-saving in R&D. Theoretical approaches represented in this meeting included: Density Functional Theory, Semi-empirical Electronic Structure Methods, Multi-scale Approaches, Modelling of PV devices, Electron Transport, and Graphene. Topics included, but were not limited to: Optical Properties of Quantum Nanostructures including Colloids and Nanotubes, Plasmonics, Magnetic Semiconductors, Photonic Structures, and Electronic Devices. This workshop ran for three days, with the objective of bringing together UK and international leading experts in the theoretical modelling of Group IV, III-V and II-VI semiconductors, as well as students, postdocs and early-career researchers. The first day focused on providing an introduction and overview of this vast field, aimed particularly at students, with several lectures given by recognized experts in various theoretical approaches. The following two days showcased some of the best theoretical research carried out in the UK in this field, with several contributions also from representatives of

  8. PREFACE: The 4th Symposium on the Mechanics of Slender Structures (MoSS2013)

    NASA Astrophysics Data System (ADS)

    Cao, Dengqing; Kaczmarczyk, Stefan

    2013-07-01

    This volume of Journal of Physics: Conference Series contains papers presented at the 4th Symposium on the Mechanics of Slender Structures (MoSS2013) run under the auspices of the Institute of Physics Applied Mechanics Group and hosted by Harbin Institute of Technology (China) from 7-9 January 2013. The conference has been organized in collaboration with the Technical Committee on Vibration and Sound of the American Society of Mechanical Engineers and follows a one day seminar on Ropes, Cables, Belts and Chains: Theory and Applications and the MoSS2006 symposium held at the University of Northampton (UK) in 2004 and 2006, respectively, the MoSS2008 symposium held at the University of Maryland Baltimore County (USA) in 2008 and the MoSS2010 symposium hosted by Mondragon University and held in San Sebastian (Spain) in 2010. The remit of the Symposium on the Mechanics of Slender Structures series involves a broad range of scientific areas. Applications of slender structures include terrestrial, marine and space systems. Moving elastic elements such as ropes, cables, belts and tethers are pivotal components of many engineering systems. Their lengths often vary when the system is in operation. The applications include vertical transportation installations and, more recently, space tether propulsion systems. Traction drive elevator installations employ ropes and belts of variable length as a means of suspension, and also for the compensation of tensile forces over the traction sheave. In cranes and mine hoists, cables and ropes are subject to length variation in order to carry payloads. Tethers experiencing extension and retraction are important components of offshore and marine installations, as well as being proposed for a variety of different space vehicle propulsion systems based on different applications of momentum exchange and electrodynamic interactions with planetary magnetic fields. Furthermore, cables and slender rods are used extensively in civil engineering

  9. R&W Club Frederick Hosts 4th Annual Golf Tournament Benefiting The Children’s Inn at NIH | Poster

    Cancer.gov

    The R&W Club Frederick’s 4th Annual Golf Tournament to benefit the Children’s Inn at NIH teed off on time despite cloudy weather and scattered showers. Employees from NCI at Frederick, the main NIH campus, and Leidos Biomed, along with family and friends, came to enjoy an afternoon at the beautiful Maryland National Golf Club in Middletown and to support a wonderful charity.

  10. Working Group on Ice Forces (4th) State-of-the-Art Report Held in Iowa City, Iowa in 1986.

    DTIC Science & Technology

    1989-02-01

    OTTAWA OF CANADA CANADA HYDRAULICS LABORATORY Preface The following papers comprise the contributions to the 4 th State-of-the-Art Report on Ice Forces...in developing an understanding of ice interacting with offshore structures. : Odes iili/or AjA Jordaan and McKenna follow with a description of the...and Moore follow with a more detailed look at ice impact loads on ship hulls. This review is based on full scale trials of several icebreaking vessels

  11. Multi-watt power blue light generation by intracavity sum- frequency-mixing in KTiOPO4 crystal.

    PubMed

    Haiyong, Zhu; Ge, Zhang; Chenghui, Huang; Yong, Wei; Lingxiong, Huang; Zhenqiang, Chen

    2008-03-03

    In this paper, a high power blue laser at 447 nm was obtained by intracavity sum-frequency-mixing of a diode-side-pumped Q-switched Nd:YAlO(3)(Nd:YAP) laser operating at 1341.4 nm. A type-I critical phase matching LiB(3)O(5) (LBO) crystal and type-II critical phase matching KTiOPO(4) (KTP) crystal were used for second harmonic generation and third harmonic generation, respectively. The phase matching condition of the KTP crystal was researched. The results show that the KTP has superiority in intracavity sum-frequency-mixing blue light generation. 4.76 W blue light output was achieved at 4.6 kHz with the pulse width of 190ns. The fluctuation of output power was better than 3% at the output power of 4.76 W during half an hour.

  12. Observation of propagating femtosecond light pulse train generated by an integrated array illuminator as a spatially and temporally continuous motion picture.

    PubMed

    Yamagiwa, Masatomo; Komatsu, Aya; Awatsuji, Yasuhiro; Kubota, Toshihiro

    2005-05-02

    We observed a propagating femtosecond light pulse train generated by an integrated array illuminator as a spatially and temporally continuous motion picture. To observe the light pulse train propagating in air, light-in-flight holography is applied. The integrated array illuminator is an optical device for generating an ultrashort light pulse train from a single ultrashort pulse. The experimentally obtained pulse width and pulse interval were 130 fs and 19.7 ps, respectively. A back-propagating femtosecond light pulse train, which is the -2 order diffracted light pulse from the array illuminator and which is difficult to observe using conventional methods, was observed.

  13. Quantum yield measurements of light-induced H₂ generation in a photosystem I-[FeFe]-H₂ase nanoconstruct.

    PubMed

    Applegate, Amanda M; Lubner, Carolyn E; Knörzer, Philipp; Happe, Thomas; Golbeck, John H

    2016-01-01

    The quantum yield for light-induced H2 generation was measured for a previously optimized bio-hybrid cytochrome c 6-crosslinked PSI(C13G)-1,8-octanedithiol-[FeFe]-H2ase(C97G) (PSI-H2ase) nanoconstruct. The theoretical quantum yield for the PSI-H2ase nanoconstruct is 0.50 molecules of H2 per photon absorbed, which equates to a requirement of two photons per H2 generated. Illumination of the PSI-H2ase nanoconstruct with visible light between 400 and 700 nm resulted in an average quantum yield of 0.10-0.15 molecules of H2 per photon absorbed, which equates to a requirement of 6.7-10 photons per H2 generated. A possible reason for the difference between the theoretical and experimental quantum yield is the occurrence of non-productive PSI(C13G)-1,8-octanedithiol-PSIC13G (PSI-PSI) conjugates, which would absorb light without generating H2. Assuming the thiol-Fe coupling is equally efficient at producing PSI-PSI conjugates as well as in producing PSI-H2ase nanoconstructs, the theoretical quantum yield would decrease to 0.167 molecules of H2 per photon absorbed, which equates to 6 photons per H2 generated. This value is close to the range of measured values in the current study. A strategy that purifies the PSI-H2ase nanoconstructs from the unproductive PSI-PSI conjugates or that incorporates different chemistries on the PSI and [FeFe]-H2ase enzyme sites could potentially allow the PSI-H2ase nanoconstruct to approach the expected theoretical quantum yield for light-induced H2 generation.

  14. Chloride conducting light activated channel GtACR2 can produce both cessation of firing and generation of action potentials in cortical neurons in response to light.

    PubMed

    Malyshev, A Y; Roshchin, M V; Smirnova, G R; Dolgikh, D A; Balaban, P M; Ostrovsky, M A

    2017-02-15

    Optogenetics is a powerful technique in neuroscience that provided a great success in studying the brain functions during the last decade. Progress of optogenetics crucially depends on development of new molecular tools. Light-activated cation-conducting channelrhodopsin2 was widely used for excitation of cells since the emergence of optogenetics. In 2015 a family of natural light activated chloride channels GtACR was identified which appeared to be a very promising tool for using in optogenetics experiments as a cell silencer. Here we examined properties of GtACR2 channel expressed in the rat layer 2/3 pyramidal neurons by means of in utero electroporation. We have found that despite strong inhibition the light stimulation of GtACR2-positive neurons can surprisingly lead to generation of action potentials, presumably initiated in the axonal terminals. Thus, when using the GtACR2 in optogenetics experiments, its ability to induce action potentials should be taken into account. Our results also open an interesting possibility of using the GtACR2 both as cell silencer and cell activator in the same experiment varying the pattern of light stimulation.

  15. White light generation using CdSe/ZnS core shell nanocrystals hybridized with InGaN/GaN light emitting diodes

    NASA Astrophysics Data System (ADS)

    Nizamoglu, S.; Ozel, T.; Sari, E.; Demir, H. V.

    2007-02-01

    We introduce white light generation using CdSe/ZnS core-shell nanocrystals of single, dual, triple and quadruple combinations hybridized with InGaN/GaN LEDs. Such hybridization of different nanocrystal combinations provides the ability to conveniently adjust white light parameters including the tristimulus coordinates (x,y), correlated colour temperature (Tc) and colour rending index (Ra). We present the design, growth, fabrication and characterization of our white hybrid nanocrystal-LEDs that incorporate combinations of (1) yellow nanocrystals (λPL = 580 nm) on a blue LED (λEL = 440 nm) with (x,y) = (0.37,0.25), Tc = 2692 K and Ra = 14.69; (2) cyan and red nanocrystals (λPL = 500 and 620 nm) on a blue LED (λEL = 440 nm) with (x,y) = (0.37,0.28), Tc = 3246 K and Ra = 19.65; (3) green, yellow and red nanocrystals (λPL = 540, 580 and 620 nm) on a blue LED (λEL = 452 nm) with (x,y) = (0.30,0.28), Tc = 7521 K and Ra = 40.95; and (4) cyan, green, yellow and red nanocrystals (λPL = 500, 540, 580 and 620 nm) on a blue LED (λEL = 452 nm) with (x,y) = (0.24,0.33), Tc = 11 171 K and Ra = 71.07. These hybrid white light sources hold promise for future lighting and display applications with their highly adjustable properties.

  16. Defense Attache Saigon: RVNAF Quarterly Assessment, 4th Quarter FY74

    DTIC Science & Technology

    1974-08-01

    Developmenti i Council CRIP Coastal Radar Improvement Plan CSB Combat Salvage Boat CSC Computer §ctence Corporation CTC Central Training Command CTD...Item Use Inspection ELTP English Language Training Program EM Enlisted Man FAC Foreign Aid Chapter FB Fuel Barge FEC Federal Electric Corporation FM...Lighter YLLC Salvage, Light Lift Craft YOG Yard Oiler FR Floating Repair YRBM Repair, Berthing and Messing Barge f YTL Small Harbor Tug YTM Medium

  17. Environmental Assessment for Destin 4th of July Fireworks and Beach Cleanup

    DTIC Science & Technology

    2008-06-01

    Leatherback turtles feed primarily on jellyfish but will occasionally eat sea urchins , squid, tunicates, fish, blue-green algae, and floating...will arrive at the Community Beach Center. After the day’s sea turtle survey is complete, a crew of four people, using pre- designated access routes...the night. Staff will be briefed to use minimal to no light on the beach due to sea turtle concerns. In addition to the setup, a preliminary trash

  18. Self-Phase-Matched Second-Harmonic and White-Light Generation in a Biaxial Zinc Tungstate Single Crystal

    PubMed Central

    Osewski, Pawel; Belardini, Alessandro; Petronijevic, Emilija; Centini, Marco; Leahu, Grigore; Diduszko, Ryszard; Pawlak, Dorota A.; Sibilia, Concita

    2017-01-01

    Second-order nonlinear optical materials are used to generate new frequencies by exploiting second-harmonic generation (SHG), a phenomenon where a nonlinear material generates light at double the optical frequency of the input beam. Maximum SHG is achieved when the pump and the generated waves are in phase, for example through birefringence in uniaxial crystals. However, applying these materials usually requires a complicated cutting procedure to yield a crystal with a particular orientation. Here we demonstrate the first example of phase matching under the normal incidence of SHG in a biaxial monoclinic single crystal of zinc tungstate. The crystal was grown by the micro-pulling-down method with the (102) plane perpendicular to the growth direction. Additionally, at the same time white light was generated as a result of stimulated Raman scattering and multiphoton luminescence induced by higher-order effects such as three-photon luminescence enhanced by cascaded third-harmonic generation. The annealed crystal offers SHG intensities approximately four times larger than the as grown one; optimized growth and annealing conditions may lead to much higher SHG intensities. PMID:28338074

  19. Self-Phase-Matched Second-Harmonic and White-Light Generation in a Biaxial Zinc Tungstate Single Crystal

    NASA Astrophysics Data System (ADS)

    Osewski, Pawel; Belardini, Alessandro; Petronijevic, Emilija; Centini, Marco; Leahu, Grigore; Diduszko, Ryszard; Pawlak, Dorota A.; Sibilia, Concita

    2017-03-01

    Second-order nonlinear optical materials are used to generate new frequencies by exploiting second-harmonic generation (SHG), a phenomenon where a nonlinear material generates light at double the optical frequency of the input beam. Maximum SHG is achieved when the pump and the generated waves are in phase, for example through birefringence in uniaxial crystals. However, applying these materials usually requires a complicated cutting procedure to yield a crystal with a particular orientation. Here we demonstrate the first example of phase matching under the normal incidence of SHG in a biaxial monoclinic single crystal of zinc tungstate. The crystal was grown by the micro-pulling-down method with the (102) plane perpendicular to the growth direction. Additionally, at the same time white light was generated as a result of stimulated Raman scattering and multiphoton luminescence induced by higher-order effects such as three-photon luminescence enhanced by cascaded third-harmonic generation. The annealed crystal offers SHG intensities approximately four times larger than the as grown one; optimized growth and annealing conditions may lead to much higher SHG intensities.

  20. Field-programmable gate array based arbitrary signal generator and oscilloscope for use in slow light and storage of light experiments

    NASA Astrophysics Data System (ADS)

    Nikolić, Stanko N.; Batić, Viktor; Panić, Bratimir; Jelenković, Branislav M.

    2013-06-01

    We present a field-programmable gate array (FPGA) based device that simultaneously generates two arbitrary analog voltage signals with the maximum sample rate of 1.25 MHz and acquires two analog voltage signals with the maximum sample rate of 2.5 MHz. All signals are synchronized with internal FPGA clock. The personal computer application developed for controlling and communicating with FPGA chip provides the shaping of the output signals by mathematical expressions and real-time monitoring of the input signals. The main advantages of FPGA based digital-to-analog and analog-to-digital cards are high speed, rapid reconfigurability, friendly user interface, and low cost. We use this module in slow light and storage of light experiments performed in Rb buffer gas cell.

  1. Field-programmable gate array based arbitrary signal generator and oscilloscope for use in slow light and storage of light experiments.

    PubMed

    Nikolić, Stanko N; Batić, Viktor; Panić, Bratimir; Jelenković, Branislav M

    2013-06-01

    We present a field-programmable gate array (FPGA) based device that simultaneously generates two arbitrary analog voltage signals with the maximum sample rate of 1.25 MHz and acquires two analog voltage signals with the maximum sample rate of 2.5 MHz. All signals are synchronized with internal FPGA clock. The personal computer application developed for controlling and communicating with FPGA chip provides the shaping of the output signals by mathematical expressions and real-time monitoring of the input signals. The main advantages of FPGA based digital-to-analog and analog-to-digital cards are high speed, rapid reconfigurability, friendly user interface, and low cost. We use this module in slow light and storage of light experiments performed in Rb buffer gas cell.

  2. Statistical properties of squeezed beams of light generated in parametric interactions

    NASA Technical Reports Server (NTRS)

    Vyas, Reeta

    1992-01-01

    Fluctuation properties of squeezed photon beams generated in three wave mixing processes such as second harmonic generation, degenerate and nondegenerate parametric oscillations, and homodyne detection are studied in terms of photon sequences recorded by a photodetector.

  3. Something going on in Milan: a review of the 4th International PhD Student Cancer Conference.

    PubMed

    Segré, C

    2010-01-01

    The 4th International PhD Student Cancer Conference was held at the IFOM-IEO-Campus in Milan from 19-21 May 2010 http://www.semm.it/events_researchPast.phpThe Conference covered many topics related to cancer, from basic biology to clinical aspects of the disease. All attendees presented their research, by either giving a talk or presenting a poster. This conference is an opportunity to introduce PhD students to top cancer research institutes across Europe.THE CORE PARTICIPANTING INSTITUTES INCLUDED: European School of Molecular Medicine (SEMM)-IFOM-IEO Campus, MilanBeatson Institute for Cancer Research (BICR), GlasgowCambridge Research Institute (CRI), Cambridge, UKMRC Gray Institute of Radiation Biology (GIROB), OxfordLondon Research Institute (LRI), LondonPaterson Institute for Cancer Research (PICR), ManchesterThe Netherlands Cancer Institute (NKI), Amsterdam'You organizers have crushed all my prejudices towards Italians. Congratulations, I enjoyed the conference immensely!' Even if it might have sounded like rudeness for sure this was supposed to be a genuine compliment (at least, that's how we took it), also considering that it was told by a guy who himself was the fusion of two usually antithetical concepts: fashion style and English nationality.The year 2010 has marked an important event for Italian research in the international scientific panorama: the European School of Molecular Medicine (SEMM) had the honour to host the 4th International PhD Student Cancer Conference, which was held from 19-21 May 2010 at the IFOM-IEO-Campus (http://www.semm.it/events_researchPast.php) in Milan.The conference was attended by more than one hundred students, coming from a selection of cutting edge European institutes devoted to cancer research. The rationale behind it is the promotion of cooperation among young scientists across Europe to debate about science and to exchange ideas and experiences. But that is not all, it is also designed for PhD students to get in touch

  4. Propagation of the light generated by quasi-homogeneous sources through quasi-homogeneous media

    NASA Astrophysics Data System (ADS)

    Li, Jia; Chen, Yan-Ru; Zhao, Qi; Zhou, Mu-Chun; Xu, Shi-Xue

    2010-01-01

    The spectral density of the quasi-homogeneous (QH) light has been known when it scatters on QH media or propagates in free space. The case that QH sources are surrounded by QH media is proposed in this paper. Under the paraxial approximation, the spectral density of the QH light propagating through QH media is derived. A modified scaling law for the propagation of the QH light through QH media is also obtained. This law also holds true in the far field beyond the paraxial approximation.

  5. Generating High-Brightness Light Ion Beams for Inertial Fusion Energy

    SciTech Connect

    Adams, R.G.; Bailey, J.E.; Cuneno, M.E.; Desjarlais, M.P.; Filuk, A.B.; Hanson, D.L.; Johnson, D.J.; Mehlohorn, T.A.; Menge, P.R.; Olson, C.L.; Pointon, T.D. Slutz, S.A.; Vesey, R.A.; Welch, D.R.; Wenger, D.F.

    1998-10-22

    Light ion beams may be the best option for an Inertial Fusion Energy (IFE) driver from the standpoint of ei%ciency, standoff, rep-rate operation and cost. This approach uses high-energy-density pulsed power to efficiently accelerate ions in one or two stages at fields of 0.5 to 1.0 GV/m to produce a medium energy (30 MeV), high-current (1 MA) beam of light ions, such as lithium. Ion beams provide the ability for medium distance transport (4 m) of the ions to the target, and standofl of the driver from high- yield implosions. Rep-rate operation of' high current ion sources has ako been demonstrated for industrial applications and couId be applied to IFE. Although (hese factors make light ions the best Iong-teml pulsed- power approach to IFE, light-ion research is being suspended this year in favor of a Z-pinch-driven approach which has the best opport lnity to most-rapidly achieve the U.S. Department of Energy sponsor's goal of high-yield fusion. This paper will summarize the status and most recent results of the light-ion beam program at Sandia National Laboratories (SNL), and document the prospects of light ions for future IFE driver development.

  6. Doppler shift generated by a moving diffraction grating under incidence by polychromatic diffuse light.

    PubMed

    Dossou, Kokou B

    2016-05-20

    We consider the spectral response of moving diffraction gratings, in which the incident light extends over a broad angular range and where the diffracted light is observed from a specific angle. We show that the dispersion relation between the frequency perceived by an observer who is looking at a moving grating and the incident frequency can exhibit some unique features, such as a flat band (i.e., a local minimum). An observer can see the light diffracted into a nonspecular diffraction order from a multitude of incident light rays, and the angle of incidence of each ray is frequency dependent; as a consequence, when the grating is moving, each incident ray experiences a Doppler shift in frequency that depends on its angle of incidence. We find that remarkable features appear near a Wood anomaly where the angle of incidence, for a given diffraction angle, can change very quickly with frequency. This means that light of multiple frequencies and incident from multiple angles can be mixed by the motion of the grating into the same diffracted ray and their frequencies can be compressed into a narrower range. The existence of a flat band means that a moving grating can be used as a device to increase the intensity of the perceived diffracted light due to spectral compression. The properties of a grating in motion in sunlight can also be relevant to the study of naturally occurring gratings which are typically in oscillatory motion.

  7. Far-infrared-light shadowgraphy for high extraction efficiency of extreme ultraviolet light from a CO2-laser-generated tin plasma

    NASA Astrophysics Data System (ADS)

    Matsukuma, Hiraku; Hosoda, Tatsuya; Suzuki, Yosuke; Yogo, Akifumi; Yanagida, Tatsuya; Kodama, Takeshi; Nishimura, Hiroaki

    2016-08-01

    The two-color, double-pulse method is an efficient scheme to generate extreme ultraviolet light for fabricating the next generation semiconductor microchips. In this method, a Nd:YAG laser pulse is used to expand a several-tens-of-micrometers-scale tin droplet, and a CO2 laser pulse is subsequently directed at the expanded tin vapor after an appropriate delay time. We propose the use of shadowgraphy with a CO2 laser probe-pulse scheme to optimize the CO2 main-drive laser. The distribution of absorption coefficients is derived from the experiment, and the results are converted to a practical absorption rate for the CO2 main-drive laser.

  8. Miniature light bulb reconstructible and large-sized computer-generated holograms recorded with an image setter

    NASA Astrophysics Data System (ADS)

    Kajiki, Yoshinori; Ueda, Hiroaki; Tanaka, Kazuyuki; Okamoto, Hideki; Shimizu, Eiji

    1995-07-01

    Visualization of 3D information or 3D displays are important subjects. We have been researching 3D displays using computer-generated holograms (CGHs). We set our sights on making large and high quality 3D displays. In this paper we present an approach to making large CGHs relatively easily, and at low cost, which are binary Fresnel holograms and are recorded by using a high resolution laser printer (an image setter). By using the image setter it is possible to draw large CGH patterns very easily. Furthermore, we found it was possible to reconstruct CGHs with light-emitting diodes or miniature light bulbs. Making good use of this advantage we propose a method of making larger 3D displays by the multiple comstruction using plural light sources and CGHs.

  9. Enhancement of second harmonic generation in NaNO{sub 2}-infiltrated opal photonic crystal using structural light focusing

    SciTech Connect

    Zaytsev, Kirill I. Yurchenko, Stanislav O.

    2014-08-04

    Experimental and numerical results for second harmonic generation (SHG) in photonic crystal (PC) based on NaNO{sub 2}-infiltrated opal matrix are presented. SHG is performed in reflection mode; thus, the direction of the SHG maximum is equal to the angle of mirror reflection. The PC was pumped with femtosecond optical pulses at different angles of incidence, allowing the dependence of the SHG efficiency on the location of the fundamental wavelength toward the PC band gap (BG) to be examined. The most efficient SHG was observed when pumping the BG of the PC. To interpret the experimental results, finite-difference time-domain numerical simulations of the light interaction with the PC were conducted. The observed effect of highly efficient SHG is associated with structural light focusing, and, as a consequence, with strong optical field localization within certain near-surface PC regions. Thus, SHG enhancement based on structural light focusing in PC was demonstrated.

  10. Real-time optical correlator using computer-generated holographic filter on a liquid crystal light valve

    NASA Technical Reports Server (NTRS)

    Chao, Tien-Hsin; Yu, Jeffrey

    1990-01-01

    Limitations associated with the binary phase-only filter often used in optical correlators are presently circumvented in the writing of complex-valued data on a gray-scale spatial light modulator through the use of a computer-generated hologram (CGH) algorithm. The CGH encodes complex-valued data into nonnegative real CGH data in such a way that it may be encoded in any of the available gray-scale spatial light modulators. A CdS liquid-crystal light valve is used for the complex-valued CGH encoding; computer simulations and experimental results are compared, and the use of such a CGH filter as the synapse hologram in a holographic optical neural net is discussed.

  11. Enhancement of second harmonic generation in NaNO2-infiltrated opal photonic crystal using structural light focusing

    NASA Astrophysics Data System (ADS)

    Zaytsev, Kirill I.; Yurchenko, Stanislav O.

    2014-08-01

    Experimental and numerical results for second harmonic generation (SHG) in photonic crystal (PC) based on NaNO2-infiltrated opal matrix are presented. SHG is performed in reflection mode; thus, the direction of the SHG maximum is equal to the angle of mirror reflection. The PC was pumped with femtosecond optical pulses at different angles of incidence, allowing the dependence of the SHG efficiency on the location of the fundamental wavelength toward the PC band gap (BG) to be examined. The most efficient SHG was observed when pumping the BG of the PC. To interpret the experimental results, finite-difference time-domain numerical simulations of the light interaction with the PC were conducted. The observed effect of highly efficient SHG is associated with structural light focusing, and, as a consequence, with strong optical field localization within certain near-surface PC regions. Thus, SHG enhancement based on structural light focusing in PC was demonstrated.

  12. Visible light photoredox catalysis: generation and addition of N-aryltetrahydroisoquinoline-derived α-amino radicals to Michael acceptors.

    PubMed

    Kohls, Paul; Jadhav, Deepak; Pandey, Ganesh; Reiser, Oliver

    2012-02-03

    The photoredox-catalyzed coupling of N-aryltetrahydroisoquinoline and Michael acceptors was achieved using Ru(bpy)(3)Cl(2) or [Ir(ppy)(2)(dtb-bpy)]PF(6) in combination with irradiation at 455 nm generated by a blue LED, demonstrating the trapping of visible light generated α-amino radicals. While intermolecular reactions lead to products formed by a conjugate addition, in intramolecular variants further dehydrogenation occurs, leading directly to 5,6-dihydroindolo[2,1-a]tetrahydroisoquinolines, which are relevant as potential immunosuppressive agents.

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

    NASA Astrophysics Data System (ADS)

    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.

  14. Light-triggered liposomal cargo delivery platform incorporating photosensitizers and gold nanoparticles for enhanced singlet oxygen generation and increased cytotoxicity

    PubMed Central

    Kautzka, Zofia; Clement, Sandhya; Goldys, Ewa M; Deng, Wei

    2017-01-01

    We developed light-triggered liposomes incorporating 3–5 nm hydrophobic gold nanoparticles and Rose Bengal (RB), a well-known photosensitizer used for photodynamic therapy. Singlet oxygen generated by these liposomes with 532 nm light illumination was characterized for varying the molar ratio of lipids and gold nanoparticles while keeping the amount of RB constant. Gold nanoparticles were found to enhance the singlet oxygen generation rate, with a maximum enhancement factor of 1.75 obtained for the molar ratio of hydrogenated soy l-α-phosphatidylcholine:1,2-dioleoyl-sn-glycero-3-phosphoethanolamine-N-(hexanoylamine):gold of 57:5:17 compared with liposomes loaded with RB alone. The experimental results could be explained by the local electric field enhancement caused by gold nanoparticles. We further assessed cellular cytotoxicity of gold-loaded liposomes by encapsulating an antitumor drug, doxorubicin (Dox); such Dox-loaded liposomes were applied to human colorectal cancer cells (HCT116) and exposed to light. Gold-loaded liposomes containing RB and Dox where Dox release was triggered by light were found to exhibit higher cytotoxicity compared with the liposomes loaded with RB and Dox alone. Our results indicate that gold-loaded liposomes incorporating photosensitizers may serve as improved agents in photodynamic therapy and chemotherapy. PMID:28203076

  15. DESIGN, SYNTHESIS AND STUDY OF MULTI-COMPONENT AND INTEGRATED SYSTEMS FOR LIGHT-DRIVEN HYDROGEN GENERATION

    SciTech Connect

    Professor Richard Eisenberg

    2012-07-18

    The research focussed on fundamental problems in the conversion of light to stored chemical energy. Specifically, work was completed on the design, synthesis and study of multi-component super- and supramolecular systems for photoinduced charge separation, one of the key steps in artificial photosynthesis, and on the use of these and related systems for the photochemical generation of H2 from water. At the center of these systems are chromophores comprised of square planar coordinated Pt(II) ions with arylacetylide and either diimine or terpyridyl ligands. Previous work had shown that the chromophores are photoluminescent in fluid solution with long-lived metal-to-ligand charge transfer (3MLCT) excited states that are necessarily directional. An advance which set the stage for a number of proposed studies was the light-driven production of hydrogen from water using a Pt(terpyridyl)(arylacetylide)+ chromophore and a sacrificial electron donor. The reaction is catalytic and appears to rival previously reported ruthenium bipyridyl systems in terms of H2 production. Variation of system components and mechanistic studies were conducted to understand better the individual steps in the overall process and how to improve its efficiency. Success with light driven H2 generation was employed as a key probe as new systems were constructed consisting of triads for photoinduced charge separation placed in close proximity to the H2 generating catalyst - a Pt colloid - through direct linkage or supramolecular interactions with the polymer used to stabilize the colloid. In order to prepare new donor-chromophore-acceptor (D-C-A) triads and associated D-C and C-A dyads, new ligands were synthesized having functional groups for different coupling reactions such as simple amide formation and Pd-catalyzed coupling. In these systems, the donor was attached to the arylacetylide ligands and the acceptor was linked to the diimine or terpyridyl chelate. Research under the contract proved

  16. Lighting

    SciTech Connect

    Audin, L.

    1994-12-31

    EPAct covers a vast territory beyond lighting and, like all legislation, also contains numerous {open_quotes}favors,{close_quotes} compromises, and even some sleight-of-hand. Tucked away under Title XIX, for example, is an increase from 20% to 28% tax on gambling winnings, effective January 1, 1993 - apparently as a way to help pay for new spending listed elsewhere in the bill. Overall, it is a landmark piece of legislation, about a decade overdue. It remains to be seen how the Federal Government will enforce upgrading of state (or even their own) energy codes. There is no mention of funding for {open_quotes}energy police{close_quotes} in EPAct. Merely creating such a national standard, however, provides a target for those who sincerely wish to create an energy-efficient future.

  17. Development of Optical Crystals for High Power and Tunable Visible and Infrared Light Generation

    DTIC Science & Technology

    2015-02-11

    and third order optical nonlinearities which are essential for second harmonic generation, optical parametric oscillation, optical switching, and...essential for second harmonic generation, optical parametric oscillation, optical switching, and wavelength conversion. In spite of being known and...compounds including LiInSe2 have been extensively studied for non-linear optical applications such as second harmonic generation.[1][2][3] We report on

  18. Caldecott 4th bore tunnel project: influence of ground water flows and inflows triggered by tectonic fault zones?

    NASA Astrophysics Data System (ADS)

    Neuhuber, G.; G. Neuhuber1, W. Klary1, A. Nitschke1, B. Thapa2, Chris Risden3, T. Crampton4, D. Zerga5

    2011-12-01

    The 4th Bore is a highway tunnel on California State Route 24 currently under construction. The 4th Bore is undertaken by the California State Department of Transportation (CALTRANS) and the Contra Costa County Transportation Commission (CCTC) to alleviate traffic congestion on SR24 connecting the cities of Oakland and Orinda in the San Francisco East Bay Area. The cost for the 4th Bore is estimated at $ 390.8 Mill. The 3,249 ft long 4th Bore tunnel will have excavated dimensions of approximately 40 ft height and 49 ft width. A total of 7 cross passages will run between the 3rd and the new 4th bore. Geology and Hydrogeology: The project is located in the Oakland Berkeley Hills of the SF Bay Area. The Caldecott Tunnels lie within the easterly assemblage of the Hayward fault zone province which consists of a sequence of sedimentary and volcanic rocks that accumulated in the interval between about 16 and 8.4 Ma (Miocene). The basal rocks of these Tertiary deposits consist of deep marine basin sediments of the Monterey Group. These rocks are overlain uncomfortably by an interbedded sequence of terrestrial sediments (Orinda Formation) and volcanic rocks (Moraga Formation). The Tertiary rocks have been folded into large amplitude, NW trending folds that are cut by N trending strike and slip faults. The SF Bay Region, which is crossed by 4 major faults (San Gregorio, San Andreas, Hayward, and Calaveras), is considered one of the more seismically active regions of the world. The active Hayward fault lies 0.9mi to the west of the Caldecott Tunnels and is the closest major fault to the project area. The tunnel is at the moment under top heading construction: West Portal (360ft) and East Portal (1,968.5ft). While major faults typically influence groundwater flow, characterization of such influences is extremely difficult because of the heterogeneity of the hydraulic systems and the different lithological parameters and influences. Four major inactive fault zones striking

  19. Compact high-power red-green-blue laser light source generation from a single lithium tantalate with cascaded domain modulation.

    PubMed

    Xu, P; Zhao, L N; Lv, X J; Lu, J; Yuan, Y; Zhao, G; Zhu, S N

    2009-06-08

    1W quasi-white-light source has been generated from a single lithium tantalate with cascaded domain modulation. The quasi-white-light is combined by proper proportion of the red, green and blue laser light. The red and the blue result from a compact self-sum frequency optical parametric oscillation when pumped by a single green laser. The efficiency of quasi-white-light from the green pump reaches 27%. This compact design can be employed not only as a stable and powerful RGB light source but also an effective blue laser generator.

  20. Highly efficient visible light-induced O₂ generation by self-assembled nanohybrids of inorganic nanosheets and polyoxometalate nanoclusters.

    PubMed

    Gunjakar, Jayavant L; Kim, Tae Woo; Kim, In Young; Lee, Jang Mee; Hwang, Seong-Ju

    2013-01-01

    Unusually high photocatalytic activity of visible light-induced O₂ generation can be achieved by electrostatically-derived self-assembly between exfoliated Zn-Cr-LDH 2D nanosheets and POM 0D nanoclusters (W₇O₂₄⁶⁻ and V₁₀O₂₈⁶⁻) acting as an electron acceptor. This self-assembly can provide a high flexibility in the control of the chemical composition and pore structure of the resulting LDH-based nanohybrids. The hybridization with POM nanoclusters remarkably enhances the photocatalytic activity of the pristine Zn-Cr-LDH, which is attributable to the formation of porous structure and depression of charge recombination. Of prime interest is that the excellent photocatalytic activity of the as-prepared Zn-Cr-LDH-POM nanohybrid for visible light-induced O₂ generation can be further enhanced by calcination at 200 °C, leading to the very high apparent quantum yield of ∼75.2% at 420 nm. The present findings clearly demonstrate that the self-assembly of LDH-POM is fairly powerful in synthesizing novel LDH-based porous nanohybrid photocatalyst for visible light-induced O₂ generation.

  1. Highly Efficient Visible Light-Induced O2 Generation by Self-Assembled Nanohybrids of Inorganic Nanosheets and Polyoxometalate Nanoclusters

    PubMed Central

    Gunjakar, Jayavant L.; Kim, Tae Woo; Kim, In Young; Lee, Jang Mee; Hwang, Seong-Ju

    2013-01-01

    Unusually high photocatalytic activity of visible light-induced O2 generation can be achieved by electrostatically-derived self-assembly between exfoliated Zn-Cr-LDH 2D nanosheets and POM 0D nanoclusters (W7O246− and V10O286−) acting as an electron acceptor. This self-assembly can provide a high flexibility in the control of the chemical composition and pore structure of the resulting LDH-based nanohybrids. The hybridization with POM nanoclusters remarkably enhances the photocatalytic activity of the pristine Zn-Cr-LDH, which is attributable to the formation of porous structure and depression of charge recombination. Of prime interest is that the excellent photocatalytic activity of the as-prepared Zn-Cr-LDH-POM nanohybrid for visible light-induced O2 generation can be further enhanced by calcination at 200 °C, leading to the very high apparent quantum yield of ∼75.2% at 420 nm. The present findings clearly demonstrate that the self-assembly of LDH–POM is fairly powerful in synthesizing novel LDH-based porous nanohybrid photocatalyst for visible light-induced O2 generation. PMID:23801108

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

    NASA Astrophysics Data System (ADS)

    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.

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

    PubMed Central

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

    2016-01-01

    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. PMID:27225857

  4. A light-assisted biomass fuel cell for renewable electricity generation from wastewater.

    PubMed

    Chamousis, Rachel L; Osterloh, Frank E

    2012-08-01

    A solar-energy-driven biomass fuel cell for the production of electricity from wastewater using only air and light as additional resources is described. The device consists of a photoelectrochemical cell that contains a nanostructured titanium dioxide or tungsten trioxide film as photoanode and a platinum air electrode as cathode, in separate compartments. The TiO(2) or WO(3) films are fabricated from TiO(2) nanocrystals or from sodium tungstate solutions on top of fluorine-doped tin dioxide. Devices were tested with electrolyte only, synthetic wastewater, or with aqueous glucose solution, under irradiation with sunlight, broad spectral illumination, and monochromatic light. Measured light conversion efficiencies were between 0.007 % and 1.7 %, depending on conditions. The highest efficiency (1.7 %) and power output (0.73 mW cm(-2)) are determined for TiO(2) electrodes under 395 nm illumination. In contrast to TiO(2), the WO(3) electrodes are active under visible light (>440 nm), but the IPCE value is low (2 %). Apart from limited visible-light absorption, the overall performance of the device is limited by the substrate concentration in the water and by transport resistance through the cell.

  5. International Symposium on Stratified Flows (4th) Held in Grenoble, France on June 29-July 2, 1994. Volume 3

    DTIC Science & Technology

    1994-10-10

    differential geometry aproach to geophysical flows " - to be published in Phys.Letters A 9 The structure of the turbulent wake and the random internal wave field... flows , the Sc effects should come into play especially when Re drop to values of the order of [(cX/tX2 ,n(Sc) -2; such low Reynolds numbers are not...proceedings 29 June - 2 July 1994 4. Title & subtitle 5a. Contract or Grant # 4th International Symposium on Stratified Flows N00014-94-J-9018 5b

  6. Synapses as Therapeutic Targets for Autism Spectrum Disorders: An International Symposium Held in Pavia on July 4th, 2014

    PubMed Central

    Curatolo, Paolo; Ben-Ari, Yehezkel; Bozzi, Yuri; Catania, Maria Vincenza; D’Angelo, Egidio; Mapelli, Lisa; Oberman, Lindsay M.; Rosenmund, Christian; Cherubini, Enrico

    2014-01-01

    New progresses into the molecular and cellular mechanisms of autism spectrum disorders (ASDs) have been discussed in 1 day international symposium held in Pavia (Italy) on July 4th, 2014 entitled “synapses as therapeutic targets for autism spectrum disorders” (satellite of the FENS Forum for Neuroscience, Milan, 2014). In particular, world experts in the field have highlighted how animal models of ASDs have greatly advanced our understanding of the molecular pathways involved in synaptic dysfunction leading sometimes to “synaptic clinical trials” in children. PMID:25324723

  7. 4th Quarter Transportation Report FY 2014: Radioactive Waste Shipments to and from the Nevada National Security Site (NNSS)

    SciTech Connect

    Gregory, Louis

    2014-12-02

    This report satisfies the U.S. Department of Energy (DOE), National Nuclear Security Administration Nevada Field Office (NNSA/NFO) commitment to prepare a quarterly summary report of radioactive waste shipments to and from the Nevada National Security Site (NNSS) Radioactive Waste Management Complex (RWMC) at Area 5. There were no shipments sent for offsite treatment and returned to the NNSS this quarter. There was one shipment of two drums sent for offsite treatment and disposal. This report summarizes the 4th quarter of Fiscal Year (FY) 2014 low-level radioactive waste (LLW) and mixed low-level radioactive waste (MLLW) shipments. This report also includes annual summaries for FY 2014.

  8. Synapses as therapeutic targets for autism spectrum disorders: an international symposium held in pavia on july 4th, 2014.

    PubMed

    Curatolo, Paolo; Ben-Ari, Yehezkel; Bozzi, Yuri; Catania, Maria Vincenza; D'Angelo, Egidio; Mapelli, Lisa; Oberman, Lindsay M; Rosenmund, Christian; Cherubini, Enrico

    2014-01-01

    New progresses into the molecular and cellular mechanisms of autism spectrum disorders (ASDs) have been discussed in 1 day international symposium held in Pavia (Italy) on July 4th, 2014 entitled "synapses as therapeutic targets for autism spectrum disorders" (satellite of the FENS Forum for Neuroscience, Milan, 2014). In particular, world experts in the field have highlighted how animal models of ASDs have greatly advanced our understanding of the molecular pathways involved in synaptic dysfunction leading sometimes to "synaptic clinical trials" in children.

  9. [Light-induced control of polymerization shrinkage of dental composites by generating temporary hardness gradients].

    PubMed

    Sommer, A P; Gente, M

    1999-10-01

    Irradiation of light-curing dental filling materials in a single direction results in a temporary hardness gradient in the direction of the irradiation. The photoactivated polymerisation process begins at the site of the highest light intensity. In the simplest possible model, the polymerizing composites irradiated in a single direction shows three adjacent co-existing phases: an almost hardened, a gelled and a still plastic phase. As long as all three phases are present, any shrinking of the contracting phases can be compensated by the plastic phase. A knowledge of the distribution of these phases and their spatial and temporal modulation by the selection of suitable curing light parameters provides simple techniques for reducing shrinkage gaps around voluminous fillings in large dental cavities.

  10. Report on the 4'th scientific meeting of the "Verein zur Förderung des Wissenschaftlichen Nachwuchses in der Neurologie" (NEUROWIND e.V.) held in Motzen, Germany, Nov. 2'nd - Nov. 4'th, 2012.

    PubMed

    Linker, Ralf A; Meuth, Sven G; Magnus, Tim; Korn, Thomas; Kleinschnitz, Christoph

    2012-11-22

    From November 2nd - 4th 2012, the 4th NEUROWIND e.V. meeting was held in Motzen, Brandenburg, Germany. Again more than 60 participants, predominantly at the doctoral student or postdoc level, gathered to share their latest findings in the fields of neurovascular research, neurodegeneration and neuroinflammation. Like in the previous years, the symposium provided an excellent platform for scientific exchange and the presentation of innovative projects in the stimulating surroundings of the Brandenburg outback. This year's keynote lecture on the pathophysiological relevance of neuronal networks was given by Christian Gerloff, Head of the Department of Neurology at the University Clinic of Hamburg-Eppendorf. Another highlight of the meeting was the awarding of the NEUROWIND e.V. prize for young scientists working in the field of experimental neurology. The award is donated by the Merck Serono GmbH, Darmstadt, Germany and is endowed with 20.000 Euro. This year the jury decided unanimously to adjudge the award to Michael Gliem from the Department of Neurology at the University Clinic of Düsseldorf (group of Sebastian Jander), Germany, for his outstanding work on different macrophage subsets in the pathogenesis of ischemic stroke published in the Annals of Neurology in 2012.

  11. Band-gap nonlinear optical generation: The structure of internal optical field and the structural light focusing

    SciTech Connect

    Zaytsev, Kirill I. Katyba, Gleb M.; Yakovlev, Egor V.; Yurchenko, Stanislav O.; Gorelik, Vladimir S.

    2014-06-07

    A novel approach for the enhancement of nonlinear optical effects inside globular photonic crystals (PCs) is proposed and systematically studied via numerical simulations. The enhanced optical harmonic generation is associated with two- and three-dimensional PC pumping with the wavelength corresponding to different PC band-gaps. The interactions between light and the PC are numerically simulated using the finite-difference time-domain technique for solving the Maxwell's equations. Both empty and infiltrated two-dimensional PC structures are considered. A significant enhancement of harmonic generation is predicted owing to the highly efficient PC pumping based on the structural light focusing effect inside the PC structure. It is shown that a highly efficient harmonic generation could be attained for both the empty and infiltrated two- and three-dimensional PCs. We are demonstrating the ability for two times enhancement of the parametric decay efficiency, one order enhancement of the second harmonic generation, and two order enhancement of the third harmonic generation in PC structures in comparison to the nonlinear generations in appropriate homogenous media. Obviously, the nonlinear processes should be allowed by the molecular symmetry. The criteria of the nonlinear process efficiency are specified and calculated as a function of pumping wavelength position towards the PC globule diameter. Obtained criterion curves exhibit oscillating characteristics, which indicates that the highly efficient generation corresponds to the various PC band-gap pumping. The highest efficiency of nonlinear conversions could be reached for PC pumping with femtosecond optical pulses; thus, the local peak intensity would be maximized. Possible applications of the observed phenomenon are also discussed.

  12. Proceedings of the 4th Conference on Aerospace Materials, Processes, and Environmental Technology

    NASA Technical Reports Server (NTRS)

    Griffin, D. E. (Editor); Stanley, D. C. (Editor)

    2001-01-01

    The next millennium challenges us to produce innovative materials, processes, manufacturing, and environmental technologies that meet low-cost aerospace transportation needs while maintaining US leadership. The pursuit of advanced aerospace materials, manufacturing processes, and environmental technologies supports the development of safer, operational, next-generation, reusable, and expendable aeronautical and space vehicle systems. The Aerospace Materials, Processes, and Environmental Technology Conference (AMPET) provided a forum for manufacturing, environmental, materials, and processes engineers, scientists, and managers to describe, review, and critically assess advances in these key technology areas.

  13. Weyl semimetal generated from Dirac semimetal using off-resonant light

    NASA Astrophysics Data System (ADS)

    Cao, Jie; Qi, Fenghua; Tang, Chi Pui

    2016-12-01

    We propose a simple realization of a three-dimensional Weyl semimetal phase using off-resonant circularly polarized light in the three dimensional Dirac semimetals. Using both analytical and numerical methods, we show that a fourfold degenerate Dirac node can be further evolved into two Weyl nodes in the context of low energy Hamiltonian. The distance between the two Weyl nodes in momentum space can be controlled by the intensity and frequency of the light. Meanwhile, because this distance is proportional to the relatively large Fermi velocity, the typical character of the Weyl semimetal, such as surface Fermi arc, can be observed obviously.

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

    PubMed

    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.

  15. Energy transfer and colour tunability in UV light induced Tm(3+)/Tb(3+)/Eu(3+): ZnB glasses generating white light emission.

    PubMed

    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)D2→(3)F4), green (547nm: (5)D4→(7)F5) and red (616nm: (5)D0→(7)F2) 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.

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

    NASA Astrophysics Data System (ADS)

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

    2017-03-01

    A promising energy transfer (Tm3 + → Tb3 + → Eu3 +) approach is brought forward to generate white light emission under ultraviolet (UV) light excitation for solid state lightening. Tm3 +/Tb3 +/Eu3 + 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 360 nm (UV) excitation, triply doped Tm3 +/Tb3 +/Eu3 +: ZnB glasses simultaneously shown their characteristic emission bands in blue (454 nm: 1D2 → 3F4), green (547 nm: 5D4 → 7F5) and red (616 nm: 5D0 → 7F2) 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 Tb3 + in ET from Tm3 + → Eu3 + 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 (Tb3 +, Eu3 +) 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.

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

    PubMed

    Naren, Gaowa; Li, Shiming; Andréasson, Joakim

    2017-03-02

    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.

  18. Generation of ultrashort coherent vacuum ultraviolet pulses using electron storage rings: a new bright light source for experiments.

    PubMed

    De Ninno, G; Allaria, E; Coreno, M; Curbis, F; Danailov, M B; Karantzoulis, E; Locatelli, A; Menteş, T O; Nino, M A; Spezzani, C; Trovò, M

    2008-08-01

    We demonstrate for the first time that seeded harmonic generation on electron storage rings can produce coherent optical pulses in the vacuum ultraviolet spectral range. The experiment is performed at Elettra, where coherent pulses are generated at 132 nm, with a duration of about 100 fs. The light source has a repetition rate of 1 kHz and adjustable polarization; it is very bright, with a peak power several orders of magnitude above that of spontaneous synchrotron radiation. Owing to high stability, the source is used in a test photoemission electron microscopy experiment. We anticipate that seeded harmonic generation on storage rings can lead to unprecedented developments in time-resolved femtosecond spectroscopy and microscopy.

  19. Generation of single frequency blue light by highly efficient harmonic generation of IR laser diodes in resonance build-up cavities using nonlinear crystals

    NASA Astrophysics Data System (ADS)

    Khademian, Ali; Danekar, Koustubh; Aflakian, Nafiseh; Shiner, David

    2012-06-01

    Blue and UV lasers have a wide variety of applications, including atomic spectroscopy. We are particularly interested in 486 nm and 243 nm for hydrogen spectroscopy. Blue and UV laser diodes are at the early stages of development. At this time, harmonic generations (HG) is a viable technique to produce blue and UV light with well developed fiber coupled IR laser diodes. We recently reported a polarization maintaining (PM) fiber to fiber conversion efficiency of 71 percent overall. We used a PPKTP (Periodically Poled Potassium Titanyl Phosphate) crystal in an external build-up cavity. The 600 mW of blue at 486 nm was generated from second HG of a 972 nm PM fiber coupled laser diode [1]. PPKTP presents blue absorption (BA) and blue light induced IR absorption (BLIIRA) which cause thermal instability and inefficiency in the buildup cavity. Another crystal, PPSLT (Periodically Poled Lithium Tantalite) promises less BA and less BLIIRA. Our latest results for producing 486 nm using PPSLT and comparison with PPKTP will be presented. [4pt] [1] Koustrubh Danekar, Ali Khademian, and David Shiner, Opt. Lett. 36, 294 (2011)

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

    SciTech Connect

    McKittrick, Joanna

    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

  1. Evolution of circadian rhythms in Drosophila melanogaster populations reared in constant light and dark regimes for over 330 generations.

    PubMed

    Shindey, Radhika; Varma, Vishwanath; Nikhil, K L; Sharma, Vijay Kumar

    2017-02-03

    Organisms are believed to have evolved circadian clocks as adaptations to deal with cyclic environmental changes, and therefore it has been hypothesized that evolution in constant environments would lead to regression of such clocks. However, previous studies have yielded mixed results, and evolution of circadian clocks under constant conditions has remained an unsettled topic of debate in circadian biology. In continuation of our previous studies, which reported persistence of circadian rhythms in Drosophila melanogaster populations evolving under constant light, here we intended to examine whether circadian clocks and the associated properties evolve differently under constant light and constant darkness. In this regard, we assayed activity-rest, adult emergence and oviposition rhythms of D. melanogaster populations which have been maintained for over 19 years (~330 generations) under three different light regimes - constant light (LL), light-dark cycles of 12:12 h (LD) and constant darkness (DD). We observed that while circadian rhythms in all the three behaviors persist in both LL and DD stocks with no differences in circadian period, they differed in certain aspects of the entrained rhythms when compared to controls reared in rhythmic environment (LD). Interestingly, we also observed that DD stocks have evolved significantly higher robustness or power of free-running activity-rest and adult emergence rhythms compared to LL stocks. Thus, our study, in addition to corroborating previous results of circadian clock evolution in constant light, also highlights that, contrary to the expected regression of circadian clocks, rearing in constant darkness leads to the evolution of more robust circadian clocks which may be attributed to an intrinsic adaptive advantage of circadian clocks and/or pleiotropic functions of clock genes in other traits.

  2. Tunable ultraviolet and blue light generation from Nd:YAB random laser bolstered by second-order nonlinear processes

    PubMed Central

    Moura, André L.; Carreño, Sandra J. M.; Pincheira, Pablo I. R.; Fabris, Zanine V.; Maia, Lauro J. Q.; Gomes, Anderson S. L.; de Araújo, Cid B.

    2016-01-01

    Ultraviolet and blue light were obtained by nonlinear frequency conversion in a random laser (RL) based on Nd0.10Y0.90Al3(BO3)4 nanocrystalline powder. RL operation at 1062 nm, due to the 4F3/2 → 4I11/2 transition of neodymium ions (Nd3+), was achieved by exciting the Nd3+ with a tunable beam from 680 to 920 nm covering the ground state absorption transitions to the 4F9/2, (4F7/2,4S3/2), (4F5/2,2H9/2), and 4F3/2 states. Light from 340 to 460 nm was obtained via the second-harmonic generation of the excitation beam while tunable blue light, from 417 to 486 nm, was generated by self-sum-frequency mixing between the excitation beam and the RL emission. PMID:27250647

  3. Tunable ultraviolet and blue light generation from Nd:YAB random laser bolstered by second-order nonlinear processes

    NASA Astrophysics Data System (ADS)

    Moura, André L.; Carreño, Sandra J. M.; Pincheira, Pablo I. R.; Fabris, Zanine V.; Maia, Lauro J. Q.; Gomes, Anderson S. L.; de Araújo, Cid B.

    2016-06-01

    Ultraviolet and blue light were obtained by nonlinear frequency conversion in a random laser (RL) based on Nd0.10Y0.90Al3(BO3)4 nanocrystalline powder. RL operation at 1062 nm, due to the 4F3/2 → 4I11/2 transition of neodymium ions (Nd3+), was achieved by exciting the Nd3+ with a tunable beam from 680 to 920 nm covering the ground state absorption transitions to the 4F9/2, (4F7/2,4S3/2), (4F5/2,2H9/2), and 4F3/2 states. Light from 340 to 460 nm was obtained via the second-harmonic generation of the excitation beam while tunable blue light, from 417 to 486 nm, was generated by self-sum-frequency mixing between the excitation beam and the RL emission.

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

    PubMed Central

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

    2014-01-01

    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. PMID:25007780

  5. Anisotropic Expansion of the Universe and Generation of Quantum Interference in Light Propagation

    NASA Astrophysics Data System (ADS)

    Fanizza, G.; Tedesco, L.

    2016-04-01

    We investigate the electrodynamic in a Bianchi type I cosmological model. This scenario reveals the possibility that photons, during their traveling, can make quantum interference. This effect is only due to the presence of two different axes of expansion in the cosmic evolution. In other word, it is possible to conclude that a purely metrical - or, equivalently, gravitational - phenomenon gives rise up to a quantum effect that manifests itself in the light propagation.

  6. Two-Photon Coherent State Light - Its Generation and Potential Applications

    DTIC Science & Technology

    1984-05-31

    SQL) on position sensing in a gravity-wave detecting interferometer . ..... .. - 14- RESEARCH SUMMARY A highly stabilized laser produces a light beam...Dolinar work [20]. Phase-Sensina Interferometry The performance of phase-sensing interferometers employin.: TCS and homo- dyne detection were analyzed...11], [12] and compared to the performance of systems employing direct detection [22]. Standard differenced direct-detection Michelson and Mach-Zehnder

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

    PubMed

    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.

  8. A Simple Model for the Light Curve Generated by a Shoemaker-Levy 9 Impact

    NASA Technical Reports Server (NTRS)

    Zahnle, Kevin; Mordecai-Mark, Mac Low

    1995-01-01

    The impact of a typical Shoemaker-Levy 9 fragment produced three light peaks as seen from Earth. The first peak is related to the entry of the fragment into the Jovian atmosphere. The second peak occurs when the exploding fireball rises above Jupiter's limb into direct view from Earth. The third peak, much the brightest, occurs when the ejecta plume falls back on the atmosphere. By contrast, Galileo, which had a direct view of the impacts, saw two peaks, one at entry, and one at plumefall. Here we present a simple, highly idealized model of a ballistic plume, which we then use to fit the observed light curve of the R impact as recorded at Mauna Kea and Mount Palomar. From the light curve we find that the nominal R fragment had diameter 450-500 m and mass approx. 2-3 x 10(exp 13) g. The uncertainty in the mass is probably about a factor of 3, with a smaller event more likely than a larger one.

  9. Light Harvesting and Photocurrent Generation in a Conjugated Polymer Nanoparticle-Reduced Graphene Oxide Composite.

    PubMed

    Patra, Amitava; Ghosh, Arnab; Jana, Bikash; Maiti, Sourav; Bera, Rajesh; Ghosh, Hiren

    2017-03-14

    Polymer - graphene nanocomposites are promising candidates towards light harvesting systems such as photocatalysis, photovoltaics; where significant charge separation occurs due to photoinduced electron transfer. Much attention has been paid to use reduced graphene oxide (r-GO) as template for anchoring various nanomaterials due to its efficient electron accepting and transport property. Here, we have prepared Poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylenevinylene] (MEH-PPV) nanoparticles from MEH-PPV polymer and investigate the change in photophysical properties due to formation of polymer nanoparticles from molecular state by using steady state and time resolved spectroscopy. Nanocomposites were designed by adding hexadecylamine (HDA) functionalized positively charged MEH-PPV PNP with negatively charged r-GO solution. Ultrafast femtosecond up-conversion and Transient absorption spectroscopy unequivocally confirms the electron transfer process from excited state of MEH-PPV PNP to r-GO at the interface of nanocomposite. Analysis reveals that the charge separation time is found to be pulse width limited (<100fs). Due to charge separation in these nanocomposites, an increment (2.6 fold) of photocurrent under visible light illumination is obtained. The fundamental understanding of the charge transfer dynamics open up new possibilities to design efficient light harvesting system based on inorganic-organic hybrid system.

  10. Application of the FUN3D Unstructured-Grid Navier-Stokes Solver to the 4th AIAA Drag Prediction Workshop Cases

    NASA Technical Reports Server (NTRS)

    Lee-Rausch, Elizabeth M.; Hammond, Dana P.; Nielsen, Eric J.; Pirzadeh, S. Z.; Rumsey, Christopher L.

    2010-01-01

    FUN3D Navier-Stokes solutions were computed for the 4th AIAA Drag Prediction Workshop grid convergence study, downwash study, and Reynolds number study on a set of node-based mixed-element grids. All of the baseline tetrahedral grids were generated with the VGRID (developmental) advancing-layer and advancing-front grid generation software package following the gridding guidelines developed for the workshop. With maximum grid sizes exceeding 100 million nodes, the grid convergence study was particularly challenging for the node-based unstructured grid generators and flow solvers. At the time of the workshop, the super-fine grid with 105 million nodes and 600 million elements was the largest grid known to have been generated using VGRID. FUN3D Version 11.0 has a completely new pre- and post-processing paradigm that has been incorporated directly into the solver and functions entirely in a parallel, distributed memory environment. This feature allowed for practical pre-processing and solution times on the largest unstructured-grid size requested for the workshop. For the constant-lift grid convergence case, the convergence of total drag is approximately second-order on the finest three grids. The variation in total drag between the finest two grids is only 2 counts. At the finest grid levels, only small variations in wing and tail pressure distributions are seen with grid refinement. Similarly, a small wing side-of-body separation also shows little variation at the finest grid levels. Overall, the FUN3D results compare well with the structured-grid code CFL3D. The FUN3D downwash study and Reynolds number study results compare well with the range of results shown in the workshop presentations.

  11. White light generation in Tb3+/Eu3+/Dy3+ triply-doped Zn(PO3)2 glass

    NASA Astrophysics Data System (ADS)

    Meza-Rocha, A. N.; Lozada-Morales, R.; Speghini, A.; Bettinelli, M.; Caldiño, U.

    2016-01-01

    A spectroscopic investigation of Tb3+/Eu3+/Dy3+ triply-doped Zn(PO3)2 glass focused on generation of white light is performed through photoluminescence spectra and decay time measurements. The white light emission obtained in the glass phosphor shows excitation wavelength dependent tunable tonality: neutral white (0.385, 0.441) of 4250 K and warm white (0.417, 0.412) of 3429 K, upon 445 and 322 nm excitations, respectively. A quantum yield of 26.1 ± 1.2% is attained upon Dy3+ excitation at 445 nm. The white luminescence is due mainly to terbium 5D4 → 7F5, dysprosium 4F9/2 → 6H15/2,13/2 and europium 5D0 → 7F2 transitions. It is demonstrated that non-radiative energy transfers Dy3+ to Tb3+ and Eu3+, and Tb3+ to Eu3+, take place in the glass phosphor excited at 445 or 322 nm. Tb3+/Eu3+/Dy3+ triply-doped Zn(PO3)2 glass, excited by AlGaN (322 nm) or InGaN (445 nm) LEDs, could then be appropriated for solid state lighting technology as neutral or warm white light phosphors.

  12. Spatiotemporal light bullets and supercontinuum generation in β-BBO crystal with competing quadratic and cubic nonlinearities.

    PubMed

    Šuminas, R; Tamošauskas, G; Valiulis, G; Dubietis, A

    2016-05-01

    We experimentally study filamentation and supercontinuum generation in a birefringent medium [beta-barium borate (β-BBO) crystal] pumped by intense 90 fs, 1.8 μm laser pulses whose carrier wavelength falls in the range of anomalous group velocity dispersion of the crystal. We demonstrate that the competition between the intrinsic cubic and cascaded-quadratic nonlinearities may serve as a useful tool for controlling the self-action effects via phase matching condition. In particular, we found that spectral superbroadening of the ordinary polarization is linked to three-dimensional self-focusing and formation of self-compressed spatiotemporal light bullets that could be accessed within a certain range of either positive or negative phase mismatch. In the extraordinary polarization, we detect giant spectral shifts of the second harmonic radiation, which are attributed to a light bullet-induced self-phase matching.

  13. Two stacked tandem white organic light-emitting diodes employing WO3 as a charge generation layer

    NASA Astrophysics Data System (ADS)

    Bin, Jong-Kwan; Lee, Na Yeon; Lee, SeungJae; Seo, Bomin; Yang, JoongHwan; Kim, Jinook; Yoon, Soo Young; Kang, InByeong

    2016-09-01

    Recently, many studies have been conducted to improve the electroluminescence (EL) performance of organic lightemitting diodes (OLEDs) by using appropriate organic or inorganic materials as charge generation layer (CGL) for their application such as full color displays, backlight units, and general lighting source. In a stacked tandem white organic light-emitting diodes (WOLEDs), a few emitting units are electrically interconnected by a CGL, which plays the role of generating charge carriers, and then facilitate the injection of it into adjacent emitting units. In the present study, twostacked WOLEDs were fabricated by using tungsten oxide (WO3) as inorganic charge generation layer and 1,4,5,8,9,11- hexaazatriphenylene hexacarbonitrile (HAT-CN) as organic charge generation layer (P-CGL). Organic P-CGL materials were used due to their ease of use in OLED fabrication as compared to their inorganic counterparts. To obtain high efficiency, we demonstrate two-stacked tandem WOLEDs as follows: ITO/HIL/HTL/HTL'/B-EML/ETL/N-CGL/P-CGL (WO3 or HAT-CN)/HTL″/YG-EML/ETL/LiF/Al. The tandem devices with blue- and yellow-green emitting layers were sensitive to the thickness of an adjacent layer, hole transporting layer for the YG emitting layer. The WOLEDs containing the WO3 as charge generation layer reach a higher power efficiency of 19.1 lm/W and the current efficiency of 51.2 cd/A with the white color coordinate of (0.316, 0.318) than the power efficiency of 13.9 lm/W, and the current efficiency of 43.7 cd/A for organic CGL, HAT-CN at 10 mA/cm2, respectively. This performance with inserting WO3 as CGL exhibited the highest performance with excellent CIE color coordinates in the two-stacked tandem OLEDs.

  14. Generation of supercontinuum light in micro-structured fiber and polarization study at different wavelengths

    NASA Astrophysics Data System (ADS)

    Valle-Atilano, F. J.; Estudillo-Ayala, J. M.; Filoteo-Razo, J. D.; Hernández-García, J. C.; Jáuregui-Vázquez, D.; Sierra-Hernández, J. M.; Rojas-Laguna, R.; Mata-Chavez, R. I.; Samano-Aguilar, L. F.

    2016-09-01

    In this work, we study the changes of polarization at different wavelengths in a supercontinuum source generated through a microchip laser in the IR spectrum. We use a microchip laser pulsed as pumped source, 1064 nm of wavelength, and a photonic crystal fiber by generated a supercontinuum spectrum. We twist the fiber to the purpose to induce birefringence and study the changes of the state of polarization, and through bandpass filters we observe a single wavelength of the broad spectrum obtained. Besides, ellipticity study for different filters and its relation with the supercontinuum results is discussed.

  15. Second-harmonic generation of light at 245 nm in a lithium tetraborate whispering gallery resonator.

    PubMed

    Fürst, Josef U; Buse, Karsten; Breunig, Ingo; Becker, Petra; Liebertz, Josef; Bohatý, Ladislav

    2015-05-01

    A millimeter-sized, monolithic whispering gallery resonator made of a lithium tetraborate, Li2B4O7, crystal was employed for doubly resonant second-harmonic generation with a continuous-wave laser source at 490 nm. An intrinsic quality factor of 2×10(8) was observed at the pump wavelength. A conversion efficiency of 2.2% was attained with 5.9 mW of mode-matched pump power. In the lithium tetraborate resonator, it is feasible to achieve phase-matching of second-harmonic generation for pump wavelengths between 486 and 506 nm.

  16. Generation of coherent waves by frequency up-conversion and down-conversion of incoherent light

    SciTech Connect

    Piskarskas, A.; Pyragaite, V.; Stabinis, A.

    2010-11-15

    It is revealed that the generation of a coherent wave by frequency conversion of incoherent waves is a characteristic feature of three-wave interaction in a nonlinear medium when angular dispersion of input waves is properly chosen. In this case the combining action of the pairs of spectral components of incoherent waves may result in the cumulative driving of a single plane monochromatic wave in up-conversion and down-conversion processes. As a fundamental result we point out an enhancement of the spectral radiance of the generated wave in comparison with incoherent waves.

  17. PREFACE: 4th International Workshop & Summer School on Plasma Physics 2010

    NASA Astrophysics Data System (ADS)

    2014-06-01

    Fourth International Workshop & Summer School on Plasma Physics 2010 The Fourth International Workshop & Summer School on Plasma Physics (IWSSPP'10) is organized by St. Kliment Ohridsky University of Sofia, with co-organizers TCPA Foundation, Association EURATOM/IRNRE, The Union of the Physicists in Bulgaria, and the Bulgarian Academy of Sciences. It was held in Kiten, Bulgaria, at the Black Sea Coast, from July 5 to July 10, 2010. The scientific programme covers the topics Fusion Plasma and Materials; Plasma Modeling and Fundamentals; Plasma Sources, Diagnostics and Technology. As the previous issues of this scientific meeting (IWSSPP'05, J. Phys.: Conf. Series 44 (2006) and IWSSPP'06, J. Phys.: Conf. Series 63 (2007), IWSSPP'08, J. Phys.: Conf. Series 207 (2010), its aim was to stimulate the creation and support of a new generation of young scientists for further development of plasma physics fundamentals and applications, as well as to ensure an interdisciplinary exchange of views and initiate possible collaborations by bringing together scientists from various branches of plasma physics. This volume of Journal of Physics: Conference Series includes 34 papers (invited lectures, contributed talks and posters) devoted to various branches of plasma physics, among them fusion plasma and materials, dc and microwave discharge modelling, transport phenomena in gas discharge plasmas, plasma diagnostics, cross sections and rate constants of elementary processes, material processing, plasma-chemistry and technology. Some of them have been presented by internationally known and recognized specialists in their fields; others are MSc or PhD students' first steps in science. In both cases, we believe they will raise readers' interest. We would like to thank the members of both the International Advisory Committee and the Local Organizing Committee, the participants who sent their manuscripts and passed through the (sometimes heavy and troublesome) refereeing and editing

  18. Solid State Ionic Materials - Proceedings of the 4th Asian Conference on Solid State Ionics

    NASA Astrophysics Data System (ADS)

    Chowdari, B. V. R.; Yahaya, M.; Talib, I. A.; Salleh, M. M.

    1994-07-01

    SO4 (X=Si, Ge, Ti) Systems * A DSC and Conductivity Study of the Influence of Cesium Ion on the Beta-Alpha Transition in Silver Iodide * Phase Diagrams, Stoichiometries and Properties of Bi4V2O11:M2+ Solid Electrolytes * Physical Properties of Electrodeposited Silver Chromotungstate * Pseudopotential Study of Bonding in the Superionic Material AgI: The Effect of Statistical Distribution of Mobile Ions * Cubic Phase Dominant Region in Submicron BaTiO3 Particles * The Crystallization of CoZr Amorphous Alloys via Electrical Resistivity * Cation Ratio Related Properties of Synthetic Mg/Al Layered Double Hydroxide and it's Nanocomposite * DC Conductivity of Nano-Particles of Silver Iodide * Effect of Anomalous Diffusion on Quasielastic Scattering in Superionic Conductors * Computer Simulation Study of Conductivity Enhancement in Superionic-Insulator Composites * Dynamics of Superionic Silver and Copper Iodide Salt Melts * Influence of Dopant Salt AgI, Glass Modifier Ag2O and Glass Formers (SeO3 + MoO3) on Electrical Conductivity in Quaternary Glassy System * Fast Ion Conductivity in the Presence of Competitive Network Formers * Role of Alkali Ions in Borate Glasses * Inelastic Light Scattering in Cadmium Borate Glasses * Investigation on Transport Properties of Mixed Glass System 0.75 [0.75AgI:0.25AgCl]. 0.25[Ag2O:CrO3] * Conduction Mechanism in Lithium Tellurite Glasses * Optimized Silver Tungstoarsenate Glass Electrolyte * Stabilized Superfine Zirconia Powder Prepared by Sol-Gel Process * Study of New PAN-based Electrolytes * Electrical and Thermal Characterization of PVA based Polymer Electrolytes * Conductive Electroactive Polymers: Versatile Solid State Ionic Materials * The Role of Ag2O Addition on the Superconducting Properties of Y-124 Compound * Absorption Spectra Studies of the C60 Films on Transition Metal Film Substrates * Effect of Alumina Dispersal on the Conductivity and Crystallite Size of Polymer Electrolyte * New Mixed Galss-Polymer Solid Electrolytes

  19. Optical imaging of Cerenkov light generation from positron-emitting radiotracers

    PubMed Central

    Robertson, R; Germanos, M S; Li, C; Mitchell, G S; Cherry, S R; Silva, M D

    2009-01-01

    Radiotracers labeled with high-energy positron-emitters, such as those commonly used for positron emission tomography (PET) studies, emit visible light immediately following decay in a medium. This phenomenon, not previously described for these imaging tracers, is consistent with Cerenkov radiation and has several potential applications, especially for in vivo molecular imaging studies. Herein we detail a new molecular imaging tool, Cerenkov Luminescence Imaging, the experiments conducted that support our interpretation of the source of the signal, and proof-of-concept in vivo studies that set the foundation for future application of this new method. PMID:19636082

  20. Human detection based on the generation of a background image by using a far-infrared light camera.

    PubMed

    Jeon, Eun Som; Choi, Jong-Suk; Lee, Ji Hoon; Shin, Kwang Yong; Kim, Yeong Gon; Le, Toan Thanh; Park, Kang Ryoung

    2015-03-19

    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 and perspective

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

    PubMed Central

    Jeon, Eun Som; Choi, Jong-Suk; Lee, Ji Hoon; Shin, Kwang Yong; Kim, Yeong Gon; Le, Toan Thanh; Park, Kang Ryoung

    2015-01-01

    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 and perspective

  2. An Ecological Study of Food Desert Prevalence and 4th Grade Academic Achievement in New York State School Districts

    PubMed Central

    Frndak, Seth E.

    2014-01-01

    Background This ecological study examines the relationship between food desert prevalence and academic achievement at the school district level. Design and methods Sample included 232 suburban and urban school districts in New York State. Multiple open-source databases were merged to obtain: 4th grade science, English and math scores, school district demographic composition (NYS Report Card), regional socioeconomic indicators (American Community Survey), school district quality (US Common Core of Data), and food desert data (USDA Food Desert Atlas). Multiple regression models assessed the percentage of variation in achievement scores explained by food desert variables, after controlling for additional predictors. Results The proportion of individuals living in food deserts significantly explained 4th grade achievement scores, after accounting for additional predictors. School districts with higher proportions of individuals living in food desert regions demonstrated lower 4th grade achievement across science, English and math. Conclusions Food deserts appear to be related to academic achievement at the school district level among urban and suburban regions. Further research is needed to better understand how food access is associated with academic achievement at the individual level. Significance for public health The prevalence of food deserts in the United States is of national concern. As poor nutrition in United States children continues to spark debate, food deserts are being evaluated as potential sources of low fruit and vegetable intake and high obesity rates. Cognitive development and IQ have been linked to nutrition patterns, suggesting that children in food desert regions may have a disadvantage academically. This research evaluates if an ecological relationship between food desert prevalence and academic achievement at the school district level can be demonstrated. Results suggest that food desert prevalence may relate to poor academic performance at

  3. Second-harmonic generation of light at 544 and 272 nm from an ytterbium-doped distributed-feedback fiber laser.

    PubMed

    Herskind, Peter; Lindballe, Jens; Clausen, Christoph; Sørensen, Jens Lykke; Drewsen, Michael

    2007-02-01

    We report external cavity second-harmonic generation of light at 544 and 272 nm based on an ytterbium-doped distributed-feedback fiber laser. The nonlinear crystal used to generate light at 544 nm is LiNbO3, and the maximum output of the cavity is 845 mW, corresponding to a conversion efficiency of 55%. In a second frequency-doubling step, using a beta-BaBa2O4 crystal, we generate up to 115 mW of light at 272 nm with a conversion efficiency of 14%.

  4. Numerical evaluation of multilayer holographic data storage with a varifocal lens generated with a spatial light modulator

    NASA Astrophysics Data System (ADS)

    Nobukawa, Teruyoshi; Nomura, Takanori

    2015-08-01

    A multilayer recording using a varifocal lens generated with a phase-only spatial light modulator (SLM) is proposed. A phase-only SLM is used for not only improving interference efficiency between signal and reference beams but also shifting a focus plane along an optical axis. A focus plane can be shifted by adding a spherical phase to a phase modulation pattern displayed on a phase-only SLM. A focal shift with adding a spherical phase was numerically confirmed. In addition, shift selectivity and recording performance of the proposed multilayer recording method were numerically evaluated in coaxial holographic data storage.

  5. Decreasing lateral diffusion of photo-generated carriers for light-addressable potentiometric array by using meshed working electrode

    NASA Astrophysics Data System (ADS)

    Chen, Dong; Liu, ShiBin; Yin, ShiMin; Liang, JinTao

    2016-09-01

    Lateral diffusion of photon-generated carriers is a critical factor affecting the signal stability and spatial resolution of light-addressable potentiometric sensor (LAPS) array. LAPS with meshed working electrode for rejecting lateral diffusion is presented. Simulation shows that using meshed working electrode can resist the lateral distribution. In an experiment, the inhibition of lateral distribution and the signal stability was studied. Results showed, using the meshed working electrode, the ability to reject the lateral distribution and the signal stability is obviously enhanced. Research in this paper may help to enhance spatial resolution and detection stability of LAPS.

  6. Generation of flower high-order Poincaré sphere laser beams from a spatial light modulator

    PubMed Central

    Lu, T. H.; Huang, T. D.; Wang, J. G.; Wang, L. W.; Alfano, R. R.

    2016-01-01

    We propose and experimentally demonstrate a new complex laser beam with inhomogeneous polarization distributions mapping onto high-order Poincaré spheres (HOPSs). The complex laser mode is achieved by superposition of Laguerre-Gaussian modes and manifests exotic flower-like localization on intensity and phase profiles. A simple optical system is used to generate a polarization-variant distribution on the complex laser mode by superposition of orthogonal circular polarizations with opposite topological charges. Numerical analyses of the polarization distribution are consistent with the experimental results. The novel flower HOPS beams can act as a new light source for photonic applications. PMID:28000779

  7. Real-time computer-generated hologram by means of liquid-crystal television spatial light modulator

    NASA Technical Reports Server (NTRS)

    Mok, Fai; Psaltis, Demetri; Diep, Joseph; Liu, Hua-Kuang

    1986-01-01

    The usefulness of an inexpensive liquid-crystal television) (LCTV) as a spatial light modulator for coherent-optical processing in the writing and reconstruction of a single computer-generated hologram has been demonstrated. The thickness nonuniformities of the LCTV screen were examined in a Mach-Zehnder interferometer, and the phase distortions were successfully removed using a technique in which the LCTV screen was submerged in a liquid gate filled with an index-matching nonconductive mineral oil with refractive index of about 1.45.

  8. Generation of flower high-order Poincaré sphere laser beams from a spatial light modulator

    NASA Astrophysics Data System (ADS)

    Lu, T. H.; Huang, T. D.; Wang, J. G.; Wang, L. W.; Alfano, R. R.

    2016-12-01

    We propose and experimentally demonstrate a new complex laser beam with inhomogeneous polarization distributions mapping onto high-order Poincaré spheres (HOPSs). The complex laser mode is achieved by superposition of Laguerre-Gaussian modes and manifests exotic flower-like localization on intensity and phase profiles. A simple optical system is used to generate a polarization-variant distribution on the complex laser mode by superposition of orthogonal circular polarizations with opposite topological charges. Numerical analyses of the polarization distribution are consistent with the experimental results. The novel flower HOPS beams can act as a new light source for photonic applications.

  9. Addressable, large-field second harmonic generation microscopy based on 2D acousto-optical deflector and spatial light modulator.

    PubMed

    Shao, Yonghong; Liu, Honghai; Qin, Wan; Qu, Junle; Peng, Xiang; Niu, Hanben; Gao, Bruce Z

    2012-09-01

    We present an addressable, large-field second harmonic generation microscope by combining a 2D acousto-optical deflector with a spatial light modulator. The SLM shapes an incoming mode-locked, near-infrared Ti:Sapphire laser beam into a multifocus array, which can be rapidly scanned by changing the incident angle of the laser beam using a 2D acousto-optical deflector. Compared to the single-beam-scan technique, the multifocus array scan can increase the scanning rate and the field-of-view size with the multi-region imaging ability.

  10. Addressable, large-field second harmonic generation microscopy based on 2D acousto-optical deflector and spatial light modulator

    PubMed Central

    Shao, Yonghong; Liu, Honghai; Qin, Wan; Qu, Junle; Peng, Xiang; Niu, Hanben

    2013-01-01

    We present an addressable, large-field second harmonic generation microscope by combining a 2D acousto-optical deflector with a spatial light modulator. The SLM shapes an incoming mode-locked, near-infrared Ti:Sapphire laser beam into a multifocus array, which can be rapidly scanned by changing the incident angle of the laser beam using a 2D acousto-optical deflector. Compared to the single-beam-scan technique, the multifocus array scan can increase the scanning rate and the field-of-view size with the multi-region imaging ability. PMID:24307756

  11. Optical four-wave mixing and generation of squeezed light in an optomechanical cavity driven by a bichromatic field

    NASA Astrophysics Data System (ADS)

    Garcés, Rafael; de Valcárcel, Germán. J.

    2014-05-01

    We show that an optomechanical cavity pumped by a bichromatic light beam can generate a signal whose frequency lies halfway between the two driving frequencies. This process can be understood as a degenerate four-wave mixing, in which two pump photons (one from each frequency) are combined to yield two identical signal photons. This process takes place between a lower and an upper threshold in terms of the pump intensity, which depend on the pump frequency difference. Close to the signal oscillation threshold a clear noise reduction in one of its quadratures is shown numerically.

  12. Conditions for invariant spectrum of light generated by scattering of partially coherent wave from quasi-homogeneous medium

    NASA Astrophysics Data System (ADS)

    Li, Jia; Wu, Pinghui; Chang, Liping

    2016-02-01

    Within the first-order Born approximation, the spectrum of light generated by the scattering of a partially coherent wave from a quasi-homogeneous (QH) medium is derived. In particular, the partially coherent incident wave is produced by Young's pinholes. It is shown that the spectrum of the scattered field is identical to the spectrum of incident plane waves if the Fourier transform of the normalized correlation coefficient (NCC) of the scattering potential satisfies a certain scaling law. The scaling law is valid when the medium size is sufficiently small compared with the space between Young' pinholes. Furthermore, comparisons are made between our conditions with the previous results.

  13. Improving proliferation resistance of high breeding gain generation 4 reactors using blankets composed of light water reactor waste

    SciTech Connect

    Hellesen, C.; Grape, S.; Haakanson, A.; Jacobson Svaerd, S.; Jansson, P.

    2013-07-01

    Fertile blankets can be used in fast reactors to enhance the breeding gain as well as the passive safety characteristics. However, such blankets typically result in the production of weapons grade plutonium. For this reason they are often excluded from Generation IV reactor designs. In this paper we demonstrate that using blankets manufactured directly from spent light water (LWR) reactor fuel it is possible to produce a plutonium product with non-proliferation characteristics on a par with spent LWR fuel of 30-50 MWd/kg burnup. The beneficial breeding and safety characteristics are retained. (authors)

  14. Preliminary Study on LiF4-ThF4-PuF4 Utilization as Fuel Salt of miniFUJI Molten Salt Reactor

    NASA Astrophysics Data System (ADS)

    Waris, Abdul; Aji, Indarta K.; Pramuditya, Syeilendra; Widayani; Irwanto, Dwi

    2016-08-01

    miniFUJI reactor is molten salt reactor (MSR) which is one type of the Generation IV nuclear energy systems. The original miniFUJI reactor design uses LiF-BeF2-ThF4-233UF4 as a fuel salt. In the present study, the use of LiF4-ThF4-PuF4 as fuel salt instead of LiF-BeF2-ThF4-UF4 will be discussed. The neutronics cell calculation has been performed by using PIJ (collision probability method code) routine of SRAC 2006 code, with the nuclear data library is JENDL-4.0. The results reveal that the reactor can attain the criticality condition with the plutonium concentration in the fuel salt is equal to 9.16% or more. The conversion ratio diminishes with the enlarging of plutonium concentration in the fuel. The neutron spectrum of miniFUJI MSR with plutonium fuel becomes harder compared to that of the 233U fuel.

  15. Nano-CdS by polymer-inorganic solid-state reaction: Visible light pristine photocatalyst for hydrogen generation

    SciTech Connect

    Kanade, K.G.; Baeg, Jin-OoK . E-mail: jobaeg@krict.re.kr; Mulik, U.P.; Amalnerkar, D.P.; Kale, B.B. . E-mail: kbbb1@yahoo.com

    2006-12-14

    We have explored the possibility of using environmentally stable nano-CdS embedded in thermally stable polymer matrix as an efficient photocatalyst for the hydrogen generation by photodecomposition of hydrogen sulphide under visible light irradiation. Initially, we restricted our attempt to the usage of nano-CdS synthesized by novel polymer-inorganic solid-state reaction between cadmium iodide and polyphenylene sulphide (PPS). The structural study revealed the formation of nanocrystallites of CdS with the particle size ranging from 6 to 28 nm entrapped in modified (cyclized) PPS matrix. A quantum yield of 19.7% for the H{sub 2} generation was accomplished with CdS-PPS nanocomposite in pristine state, which appears to be superior in comparison to that of the conventional Pt loaded CdS. We believe that this straightforward approach can be extended to synthesise other nano-metal sulphides in polymer network for photocatalytic and allied applications.

  16. Three-dimensional rendering of computer-generated holograms acquired from point-clouds on light field displays

    NASA Astrophysics Data System (ADS)

    Symeonidou, Athanasia; Blinder, David; Ceulemans, Beerend; Munteanu, Adrian; Schelkens, Peter

    2016-09-01

    Holograms, either optically acquired or simulated numerically from 3D datasets, such as point clouds, have special rendering requirements for display. Evaluating the quality of hologram generation techniques is not straightforward, since high-quality holographic display technologies are still immature, In this paper we present a framework for three-dimensional rendering of colour computer-generated holograms (CGHs) acquired from point-clouds, on high-end light field displays. This allows for the rendering of holographic content with horizontal parallax and wide viewing angle. We deploy prior work, namely a fast CGH method that inherently handles occlusion problems to acquire high quality colour holograms from point clouds. Our experiments showed that rendering holograms with the proposed framework provides 3D effect with depth disparity and horizontal-only with wide viewing angle. Therefore, it allows for the evaluation of CGH techniques regarding functional properties such as depth cues and efficient occlusion handling.

  17. Control of long electron quantum paths in high-order harmonic generation by phase-stabilized light pulses

    SciTech Connect

    Sansone, G.; Benedetti, E.; Caumes, J.-P.; Stagira, S.; Vozzi, C.; De Silvestri, S.; Nisoli, M.

    2006-05-15

    In this work we report on the first experimental demonstration of selection of the long electron quantum paths in the process of high-order harmonic generation by phase-stabilized multiple-cycle light pulses. A complete experimental investigation of the role of intensity and carrier-envelope phase of the driving pulses on the spectral characteristics of the long quantum paths is performed. Simulations based on the nonadiabatic saddle-point method and on a complete nonadiabatic three-dimensional model reproduce the main features of the experimental results. The use of phase-stabilized driving pulses allows one to control, on an attosecond temporal scale, the spectral and temporal characteristics associated with the electron quantum paths involved in the harmonic generation process.

  18. Slower carriers limit charge generation in organic semiconductor light-harvesting systems

    PubMed Central

    Stolterfoht, Martin; Armin, Ardalan; Shoaee, Safa; Kassal, Ivan; Burn, Paul; Meredith, Paul

    2016-01-01

    Blends of electron-donating and -accepting organic semiconductors are widely used as photoactive materials in next-generation solar cells and photodetectors. The yield of free charges in these systems is often determined by the separation of interfacial electron–hole pairs, which is expected to depend on the ability of the faster carrier to escape the Coulomb potential. Here we show, by measuring geminate and non-geminate losses and key transport parameters in a series of bulk-heterojunction solar cells, that the charge-generation yield increases with increasing slower carrier mobility. This is in direct contrast with the well-established Braun model where the dissociation rate is proportional to the mobility sum, and recent models that underscore the importance of fullerene aggregation for coherent electron propagation. The behaviour is attributed to the restriction of opposite charges to different phases, and to an entropic contribution that favours the joint separation of both charge carriers. PMID:27324720

  19. Attosecond dynamics of light-induced resonant hole transfer in high-order-harmonic generation

    NASA Astrophysics Data System (ADS)

    You, Jhih-An; Dahlström, Jan Marcus; Rohringer, Nina

    2017-02-01

    We present a study of high-order-harmonic generation (HHG) assisted by extreme ultraviolet (XUV) attosecond pulses, which can lead to the excitation of inner-shell electrons and the generation of a second HHG plateau. With the treatment of a one-dimensional model of krypton, based on time-dependent configuration interaction singles (TDCIS) of an effective two-electron system, we show that the XUV-assisted HHG spectrum reveals the duration of the semiclassical electron trajectories. The results are interpreted by the strong-field approximation (SFA) and the importance of the hole transfer during the tunneling process is emphasized. Finally, coherent population transfer between the inner and outer holes with attosecond pulse trains is discussed.

  20. STO-2: Support for 4th Year Operations, Recovery, and Science: Smithsonian Astrophysical Observatory Co-I

    NASA Astrophysics Data System (ADS)

    Stark, Antony

    The Lead Proposal for this investigation originates from the University of Arizona, Steward Observatory under Principal Investigator Dr. Christopher K. Walker. The Smithsonian Astrophysical Observatory (SAO) is pleased to submit this subsidiary proposal for engineering and scientific collaboration on the reflight of the Stratospheric TeraHertz Observatory (STO-2). This proposal covers Support for 4th Year Operations, Recovery, and Science as a result of the failure to launch due to weather in the 2015-2016 season. The Institutional Principal Investigator for the SAO effort is Antony A. Stark, and scientific Co-Investigators Gary Melnick, Volker Tolls, and Matthew Ashby. SAO will provide pre-flight engineering and flight monitoring support for the second Long Duration Flight (LDF) from McMurdo Sound in Antarctica. Subsequent to the flight, SAO Co-Is will contribute to data management and analysis, scientific interpretation, publication of results, and public distribution of data.

  1. 4th Annual Conference for African-American Researchers in the Mathematical Sciences (CAARMS4). Preliminary Program

    SciTech Connect

    Tapia, Richard

    1998-06-01

    In June, The Center for Research on Parallel Computation (CRPC), an NSF-funded Science and Technology Center, hosted the 4th Annual Conference for African-American Reserachers in the Mathematical Sciences (CAARMS4) at Rice University. The main goal of this conference was to highlight current work by African-American researchers and graduate students in mathematics. This conference strengthened the mathematical sciences by encouraging the increased participation of African-American and underrepresented groups into the field, facilitating working relationships between them and helping to cultivate their careers. In addition to the talks there was a graduate student poster session and tutorials on topics in mathematics and computer science. These talks, presentations, and discussions brought a broader perspective to the critical issues involving minority participation in mathematics.

  2. Medical Standby: An Experience at the 4(th) National Youth Camping and Motivation Program Organized by Maksak Malaysia.

    PubMed

    Zakaria, Mohd Idzwan; Isa, Ridzuan Mohd; Shah Che Hamzah, Mohd Shaharudin; Ayob, Noor Azleen

    2006-01-01

    Medical standby is the provision of emergency medical care and first aid for participants and/or spectators in a pre-planned event. This article describes the framework and the demographics of a medical standby at the 4(th) National Youth Camping and Motivation Program in Pasir Puteh, Kelantan from 30(th) July until the 3(rd) August 2004. The framework of the medical team is described based on the work process of any medical stand by. A medical encounter form was created for the medical standby defining the type of case seen (medical or trauma), name, age, race and diagnosis of the patient. We concluded that interagency collaboration during the initial planning and during the event itself is needed to ensure the smooth running of the medical standby. Most of the medical encounters were minor illnesses which are similar to previous studies and there was no case transferred to the hospital during that period.

  3. Macracanthorhynchus hirudinaceus Eggs in Canine Coprolite from the Sasanian Era in Iran (4th/5th Century CE)

    PubMed Central

    MOWLAVI, Gholamreza; MAKKI, Mahsasadat; HEIDARI, Zahra; REZAEIAN, Mostafa; MOHEBALI, Mehdi; ARAUJO, Adauto; BOENKE, Nicole; AALI, Abolfazl; STOLLNER, Thomas; MOBEDI, Iraj

    2015-01-01

    Present paper is the second publication introducing the paleoparasitological findings from animal coprolites obtained from archeological site of Chehrabad salt mine in northwestern Iran. The current archeological site is located in northwest of Iran, dated to the Sassanian Era (4th/5th century CE). In the summer 2012 the carnivore coprolite was obtained within the layers in the mine and were thoroughly analyzed for parasites using TSP rehydration technique. Eggs of 0 were successfully retrieved from the examined coprolite and were confidently identified based on reliable references. Identifying of M. hirudinaceus eggs in paleofeces with clear appearance as demonstrated herein, is much due to appropriate preservation condition has been existed in the salt mine .The present finding could be regarded as the oldest acanthocephalan infection in Iran. PMID:26246822

  4. Medical Standby: An Experience at the 4th National Youth Camping and Motivation Program Organized by Maksak Malaysia

    PubMed Central

    Zakaria, Mohd Idzwan; Isa, Ridzuan Mohd; Shah Che Hamzah, Mohd Shaharudin; Ayob, Noor Azleen

    2006-01-01

    Medical standby is the provision of emergency medical care and first aid for participants and/or spectators in a pre-planned event. This article describes the framework and the demographics of a medical standby at the 4th National Youth Camping and Motivation Program in Pasir Puteh, Kelantan from 30th July until the 3rd August 2004. The framework of the medical team is described based on the work process of any medical stand by. A medical encounter form was created for the medical standby defining the type of case seen (medical or trauma), name, age, race and diagnosis of the patient. We concluded that interagency collaboration during the initial planning and during the event itself is needed to ensure the smooth running of the medical standby. Most of the medical encounters were minor illnesses which are similar to previous studies and there was no case transferred to the hospital during that period. PMID:22589590

  5. Kinetic Modeling Sheds Light on the Mode of Action of Recombinant Factor VIIa on Thrombin Generation

    DTIC Science & Technology

    2011-01-01

    numerical model to generate activated factor VII (FVIIa) titration curves in the cases of normal blood composition, hemophilia A and B blood, blood...as a hemostatic agent for patients with hemophilia , congenital FVII deficiency, and Glanzmann’s thrombocytopenia [3]. Following its initial approval...normal blood composition, hemophilia A and B blood, blood lacking factor VII, blood lacking tissue factor pathway inhibitor, and diluted blood. We

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

    PubMed

    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.

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

    SciTech Connect

    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.

  8. A tunable azine covalent organic framework platform for visible light-induced hydrogen generation

    PubMed Central

    Vyas, Vijay S.; Haase, Frederik; Stegbauer, Linus; Savasci, Gökcen; Podjaski, Filip; Ochsenfeld, Christian; Lotsch, Bettina V.

    2015-01-01

    Hydrogen evolution from photocatalytic reduction of water holds promise as a sustainable source of carbon-free energy. Covalent organic frameworks (COFs) present an interesting new class of photoactive materials, which combine three key features relevant to the photocatalytic process, namely crystallinity, porosity and tunability. Here we synthesize a series of water- and photostable 2D azine-linked COFs from hydrazine and triphenylarene aldehydes with varying number of nitrogen atoms. The electronic and steric variations in the precursors are transferred to the resulting frameworks, thus leading to a progressively enhanced light-induced hydrogen evolution with increasing nitrogen content in the frameworks. Our results demonstrate that by the rational design of COFs on a molecular level, it is possible to precisely adjust their structural and optoelectronic properties, thus resulting in enhanced photocatalytic activities. This is expected to spur further interest in these photofunctional frameworks where rational supramolecular engineering may lead to new material applications. PMID:26419805

  9. Generation of photocurrent by visible-light irradiation of conjugated dawson polyoxophosphovanadotungstate-porphyrin copolymers.

    PubMed

    Azcarate, Iban; Huo, Zhaohui; Farha, Rana; Goldmann, Michel; Xu, Hualong; Hasenknopf, Bernold; Lacôte, Emmanuel; Ruhlmann, Laurent

    2015-05-26

    Four hybrid polyoxometalate-porphyrin copolymer films were obtained by the electrooxidation of zinc octaethylporphyrin in the presence of four different Dawson-type polyoxometalates bearing two pyridyl groups (POM(py)2) with various spacers. The POM monomers were designed around 1,3,5-trisubstituted benzene rings. Two of the substituents of the benzene ring are linked to the pyridyl groups, and the third is connected to the POM subunit. The four monomers vary in the relative positions of the nitrogen atoms of the pyridine rings or in the distance from the carbonyl group. The monomers were fully characterized by (1)H, (31)P, and (13)C NMR spectroscopy, electrospray mass spectrometry, IR and UV/Vis spectroscopy, and electrochemistry. The copolymers were characterized by UV/Vis spectroscopy, X-ray photoelectron spectroscopy, electrochemistry, and AFM. Their photovoltaic performance under visible light irradiation was investigated by photocurrent transient measurements under visible illumination.

  10. Coherent EUV light from high-order harmonic generation: Enhancement and applications to lensless diffractive imaging

    NASA Astrophysics Data System (ADS)

    Paul, Ariel J.

    2007-12-01

    The first half of this thesis presents the first demonstration of quasi-phase matching in the coherent high-order harmonic conversion of ultrafast laser pulses into the EUV region of the spectrum. To achieve this quasi-phase matching, a novel method of fabricating hollow waveguides with a modulated inner diameter was developed. This technique lead to significant enhancements of EUV flux at wavelengths shorter than were previously accessible by known phase-matching techniques. In the second half of this thesis, the first tabletop demonstration of lensless diffractive imaging with EUV light is presented using HHG in a gas-filled hollow waveguide to provide coherent illumination. This tabletop microscope shows a spatial resolution of ˜ 200 nm and a large depth of field. Furthermore, the technique is easily scalable to shorter wavelengths of interest to biological imaging.

  11. A tunable azine covalent organic framework platform for visible light-induced hydrogen generation

    NASA Astrophysics Data System (ADS)

    Vyas, Vijay S.; Haase, Frederik; Stegbauer, Linus; Savasci, Gökcen; Podjaski, Filip; Ochsenfeld, Christian; Lotsch, Bettina V.

    2015-09-01

    Hydrogen evolution from photocatalytic reduction of water holds promise as a sustainable source of carbon-free energy. Covalent organic frameworks (COFs) present an interesting new class of photoactive materials, which combine three key features relevant to the photocatalytic process, namely crystallinity, porosity and tunability. Here we synthesize a series of water- and photostable 2D azine-linked COFs from hydrazine and triphenylarene aldehydes with varying number of nitrogen atoms. The electronic and steric variations in the precursors are transferred to the resulting frameworks, thus leading to a progressively enhanced light-induced hydrogen evolution with increasing nitrogen content in the frameworks. Our results demonstrate that by the rational design of COFs on a molecular level, it is possible to precisely adjust their structural and optoelectronic properties, thus resulting in enhanced photocatalytic activities. This is expected to spur further interest in these photofunctional frameworks where rational supramolecular engineering may lead to new material applications.

  12. A tunable azine covalent organic framework platform for visible light-induced hydrogen generation.

    PubMed

    Vyas, Vijay S; Haase, Frederik; Stegbauer, Linus; Savasci, Gökcen; Podjaski, Filip; Ochsenfeld, Christian; Lotsch, Bettina V

    2015-09-30

    Hydrogen evolution from photocatalytic reduction of water holds promise as a sustainable source of carbon-free energy. Covalent organic frameworks (COFs) present an interesting new class of photoactive materials, which combine three key features relevant to the photocatalytic process, namely crystallinity, porosity and tunability. Here we synthesize a series of water- and photostable 2D azine-linked COFs from hydrazine and triphenylarene aldehydes with varying number of nitrogen atoms. The electronic and steric variations in the precursors are transferred to the resulting frameworks, thus leading to a progressively enhanced light-induced hydrogen evolution with increasing nitrogen content in the frameworks. Our results demonstrate that by the rational design of COFs on a molecular level, it is possible to precisely adjust their structural and optoelectronic properties, thus resulting in enhanced photocatalytic activities. This is expected to spur further interest in these photofunctional frameworks where rational supramolecular engineering may lead to new material applications.

  13. Accuracy Based Generation of Thermodynamic Properties for Light Water in RELAP5-3D

    SciTech Connect

    Cliff B. Davis

    2010-09-01

    RELAP5-3D interpolates to obtain thermodynamic properties for use in its internal calculations. The accuracy of the interpolation was determined for the original steam tables currently used by the code. This accuracy evaluation showed that the original steam tables are generally detailed enough to allow reasonably accurate interpolations in most areas needed for typical analyses of nuclear reactors cooled by light water. However, there were some regions in which the original steam tables were judged to not provide acceptable accurate results. Revised steam tables were created that used a finer thermodynamic mesh between 4 and 21 MPa and 530 and 640 K. The revised steam tables solved most of the problems observed with the original steam tables. The accuracies of the original and revised steam tables were compared throughout the thermodynamic grid.

  14. Optical Tweezers Array and Nimble Tweezers Probe Generated by Spatial- Light Modulator

    NASA Technical Reports Server (NTRS)

    Decker, Arthur J.; Jassemnejad, Baha; Seibel, Robin E.; Weiland, Kenneth E.

    2003-01-01

    An optical tweezers is being developed at the NASA Glenn Research Center as a visiblelight interface between ubiquitous laser technologies and the interrogation, visualization, manufacture, control, and energization of nanostructures such as silicon carbide (SiC) nanotubes. The tweezers uses one or more focused laser beams to hold micrometer-sized particles called tools (sometimes called tips in atomic-force-microscope terminology). A strongly focused laser beam has an associated light-pressure gradient that is strong enough to pull small particles to the focus, in spite of the oppositely directed scattering force; "optical tweezers" is the common term for this effect. The objective is to use the tools to create carefully shaped secondary traps to hold and assemble nanostructures that may contain from tens to hundreds of atoms. The interaction between a tool and the nanostructures is to be monitored optically as is done with scanning probe microscopes. One of the initial efforts has been to create, shape, and control multiple tweezers beams. To this end, a programmable spatial-light modulator (SLM) has been used to modify the phase of a laser beam at up to 480 by 480 points. One program creates multiple, independently controllable tweezer beams whose shapes can be tailored by making the SLM an adaptive mirror in an interferometer (ref. 1). The beams leave the SLM at different angles, and an optical Fourier transform maps these beams to different positions in the focal plane of a microscope objective. The following figure shows two arrays of multiple beams created in this manner. The patterns displayed above the beam array control the intensity-to-phase transformation required in programming the SLM. Three of the seven beams displayed can be used as independently controllable beams.

  15. Degradation of organic dyes by Si/SiOx core-shell nanowires: Spontaneous generation of superoxides without light irradiation.

    PubMed

    Cao, Yu; Gu, Xiaoyu; Yu, Hongkun; Zeng, Wei; Liu, Xiang; Jiang, Suhua; Li, Yuesheng

    2016-02-01

    Recently, silicon nanowires (SiNWs) have been proven to be highly active in the photocatalysis of dye degradation. However, the unstable hydrogen-terminated surface and the need for constant light irradiation hinder their extensive use. In this work, a stable silica shell was intentionally formed on the surface of SiNWs to produce Si/SiOx core-shell silicon nanowires (S-SiNWs). Light-illuminated or not, S-SiNWs showed almost identical degradation ability for the degradation of indigo carmine (IC) in both conditions, which meant neither hydrogen termination nor light irradiation was a prerequisite for the degradation activity of S-SiNWs. UV/Vis spectroscopy and liquid chromatography/mass spectrometry showed that IC was converted into isatin sulfonic acid in this process. Quenching studies and electron paramagnetic resonance spectroscopy revealed that this bleaching ability was highly dependent on superoxides. A possible mechanism was accordingly suggested. In addition, the recently discovered reductase-like activity of SiNWs can be explained by the superoxides generation.

  16. Efficient Light-driven Long Distance Charge Separation and H2 Generation in Semiconductor Quantum Rods and Nanoplatelets

    NASA Astrophysics Data System (ADS)

    Lian, Tianquan

    Quantum confined semiconductor nanocrystals (0D quantum dots, 1D quantum rods and 2D quantum platlets) have been intensively investigated as light harvesting and charge separation materials for photovoltaic and photocatalytic applications. The efficiency of these semiconductor nanocrystal-based devices depends on many fundamental processes, including light harvesting, carrier relaxation, exciton localization and transport, charge separation and charge recombination. The competition between these processes determines the overall solar energy conversion (solar to electricity or fuel) efficiency. Semiconductor nano-heterostructures, combining two or more material components, offer unique opportunities to control their charge separation properties by tailoring their compositions, dimensions and spatial arrangement. Further integration of catalysts (heterogeneous or homogeneous) to these materials form multifunctional nano-heterostructures. Using 0D, 1D and 2D CdSe/CdS/Pt heterostructures as model systems, we directly probe the above-mentioned fundamental exciton and carrier processes by transient absorption and time-resolved fluorescence spectroscopy. We are examining how to control these fundamental processes through the design of heterostructures to achieve long-lived charge separation and efficient H2 generation. In this talk, we will discuss a new model for exciton dissociation by charge transfer in quantum dots (i.e. Auger assisted electron transfer), mechanism of 1D and 2D exciton transport and dissociation in nanorods, and key factors limiting H2 generation efficiency in CdSe/CdS/Pt nanorod heterostructures.

  17. Retrieving squeezing from classically noisy light in second-harmonic generation

    NASA Astrophysics Data System (ADS)

    Ralph, T. C.; White, A. G.

    1995-05-01

    We report the results of a study of the quantum noise properties of a squeezing system involving a three-level laser pumping two similar second-harmonic-generating crystals. We show that squeezing that has been obscured by intensity and phase noise from the pump laser may be retrieved by difference detection of both second-harmonic outputs. Similarly, the squeezed vacuum formed by combining the two outputs on a 50/50 beam splitter will be squeezed at frequencies that are classically noisy in the individual beams.

  18. Generation-X: An X-ray observatory designed to observe first light objects

    NASA Astrophysics Data System (ADS)

    Windhorst, Rogier A.; Cameron, R. A.; Brissenden, R. J.; Elvis, M. S.; Fabbiano, G.; Gorenstein, P.; Reid, P. B.; Schwartz, D. A.; Bautz, M. W.; Figueroa-Feliciano, E.; Petre, R.; White, N. E.; Zhang, W. W.

    2006-03-01

    The new cosmological frontier will be the study of the very first stars, galaxies and black holes in the early Universe. These objects are invisible to the current generation of X-ray telescopes, such as Chandra. In response, the Generation-X ("Gen-X") Vision Mission has been proposed as a future X-ray observatory which will be capable of detecting the earliest objects. X-ray imaging and spectroscopy of such faint objects demands a large collecting area and high angular resolution. The Gen-X mission plans 100 m 2 collecting area at 1 keV (1000× that of Chandra), and with an angular resolution of 0.1″. The Gen-X mission will operate at Sun-Earth L2, and might involve four 8 m diameter telescopes or even a single 20 m diameter telescope. To achieve the required effective area with reasonable mass, very lightweight grazing incidence X-ray optics must be developed, having an areal density 100× lower than in Chandra, with mirrors as thin as 0.1 mm requiring active on-orbit figure control. The suite of available detectors for Gen-X should include a large-area high resolution imager, a cryogenic imaging spectrometer, and a grating spectrometer. We discuss use of Gen-X to observe the birth of the first black holes, stars and galaxies, and trace their cosmic evolution.

  19. Light Harvesting Proteins for Solar Fuel Generation in Bioengineered Photoelectrochemical Cells

    PubMed Central

    Ihssen, Julian; Braun, Artur; Faccio, Greta; Gajda-Schrantz, Krisztina; Thöny-Meyer, Linda

    2014-01-01

    The sun is the primary energy source of our planet and potentially can supply all societies with more than just their basic energy needs. Demand of electric energy can be satisfied with photovoltaics, however the global demand for fuels is even higher. The direct way to produce the solar fuel hydrogen is by water splitting in photoelectrochemical (PEC) cells, an artificial mimic of photosynthesis. There is currently strong resurging interest for solar fuels produced by PEC cells, but some fundamental technological problems need to be solved to make PEC water splitting an economic, competitive alternative. One of the problems is to provide a low cost, high performing water oxidizing and oxygen evolving photoanode in an environmentally benign setting. Hematite, α-Fe2O3, satisfies many requirements for a good PEC photoanode, but its efficiency is insufficient in its pristine form. A promising strategy for enhancing photocurrent density takes advantage of photosynthetic proteins. In this paper we give an overview of how electrode surfaces in general and hematite photoanodes in particular can be functionalized with light harvesting proteins. Specifically, we demonstrate how low-cost biomaterials such as cyanobacterial phycocyanin and enzymatically produced melanin increase the overall performance of virtually no-cost metal oxide photoanodes in a PEC system. The implementation of biomaterials changes the overall nature of the photoanode assembly in a way that aggressive alkaline electrolytes such as concentrated KOH are not required anymore. Rather, a more environmentally benign and pH neutral electrolyte can be used. PMID:24678669

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

    SciTech Connect

    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

    2004-07-01

    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.

  1. Light harvesting proteins for solar fuel generation in bioengineered photoelectrochemical cells.

    PubMed

    Ihssen, Julian; Braun, Artur; Faccio, Greta; Gajda-Schrantz, Krisztina; Thöny-Meyer, Linda

    2014-01-01

    The sun is the primary energy source of our planet and potentially can supply all societies with more than just their basic energy needs. Demand of electric energy can be satisfied with photovoltaics, however the global demand for fuels is even higher. The direct way to produce the solar fuel hydrogen is by water splitting in photoelectrochemical (PEC) cells, an artificial mimic of photosynthesis. There is currently strong resurging interest for solar fuels produced by PEC cells, but some fundamental technological problems need to be solved to make PEC water splitting an economic, competitive alternative. One of the problems is to provide a low cost, high performing water oxidizing and oxygen evolving photoanode in an environmentally benign setting. Hematite, α-Fe2O3, satisfies many requirements for a good PEC photoanode, but its efficiency is insufficient in its pristine form. A promising strategy for enhancing photocurrent density takes advantage of photosynthetic proteins. In this paper we give an overview of how electrode surfaces in general and hematite photoanodes in particular can be functionalized with light harvesting proteins. Specifically, we demonstrate how low-cost biomaterials such as cyanobacterial phycocyanin and enzymatically produced melanin increase the overall performance of virtually no-cost metal oxide photoanodes in a PEC system. The implementation of biomaterials changes the overall nature of the photoanode assembly in a way that aggressive alkaline electrolytes such as concentrated KOH are not required anymore. Rather, a more environmentally benign and pH neutral electrolyte can be used.

  2. Ribavirin exerts differential effects on functions of Cd4+ Th1, Th2, and regulatory T cell clones in hepatitis C.

    PubMed

    Langhans, Bettina; Nischalke, Hans Dieter; Arndt, Simone; Braunschweiger, Ingrid; Nattermann, Jacob; Sauerbruch, Tilman; Spengler, Ulrich

    2012-01-01

    Ribavirin improves outcomes of therapy in chronic hepatitis C but its mode of action has still remained unclear. Since ribavirin has been proposed to modulate the host's T cell responses, we studied its direct effects on CD4(+) T cell clones with diverse functional polarization which had been generated from patients with chronic hepatitis C. We analysed in vitro proliferation ([(3)H] thymidine uptake) and cytokine responses (IL-10, IFN-gamma) at varying concentrations of ribavirin (0-10 µg/ml) in 8, 9 and 7 CD4(+) TH1, TH2 and regulatory T cell (Treg) clones, respectively. In co-culture experiments, we further determined effects of ribarivin on inhibition of TH1 and TH2 effector cells by Treg clones. All clones had been generated from peripheral blood of patients with chronic hepatitis C in the presence of HCV core protein. Ribavirin enhanced proliferation of T effector cells and increased production of IFN-gamma in TH1 clones, but had only little effect on IL-10 secretion in TH2 clones. However, ribavirin markedly inhibited IL-10 release in Treg clones in a dose dependent fashion. These Treg clones suppressed proliferation of T effector clones by their IL-10 secretion, and in co-culture assays ribavirin reversed Treg-mediated suppression of T effector cells. Our in vitro data suggest that--in addition to its immunostimulatory effects on TH1 cells--ribavirin can inhibit functions of HCV-specific Tregs and thus reverses Treg-mediated suppression of T effector cells in chronic hepatitis C.

  3. Quantum teleportation of laser-generated photons with an entangled-light-emitting diode.

    PubMed

    Stevenson, R M; Nilsson, J; Bennett, A J; Skiba-Szymanska, J; Farrer, I; Ritchie, D A; Shields, A J

    2013-01-01

    Quantum teleportation can transfer information between physical systems, which is essential for engineering quantum networks. Of the many technologies being investigated to host quantum bits, photons have obvious advantages as 'pure' quantum information carriers, but their bandwidth and energy is determined by the quantum system that generates them. Here we show that photons from fundamentally different sources can be used in the optical quantum teleportation protocol. The sources we describe have bandwidth differing by a factor over 100, but we still observe teleportation with average fidelity of 0.77, beating the quantum limit by 10 standard deviations. Furthermore, the dissimilar nature of our sources exposes physics hidden in previous experiments, which we also predict numerically. These phenomena include converting qubits from Poissonian to Fock statistics, quantum interference, beats and teleportation for spectrally non-degenerate photons, and acquisition of evolving character following teleportation of a qubit.

  4. Light sources generating self-splitting beams and their propagation in non-Kolmogorov turbulence.

    PubMed

    Mei, Zhangrong

    2014-06-02

    A class of random sources producing far fields self-splitting intensity profiles with variable spacing between the x and y directions is introduced. The beam conditions for ensuring the sources to generate a beam are derived. Based on the derived analytical expression, the evolution behavior of the beams produced by these families of sources in free space and turbulence atmospheric are explored and comparatively analyzed. By changing the modulation parameters n and m, the degree of coherence of Gaussian Schell-model source in the x and y directions are modulated respectively, and then the number of splitting beams and the spacing between splitting beams can be adjusted. It is illustrated that the self-splitting intensity profile is stable when beams propagate in free space, but they eventually transformed into a Gaussian profiles when it passes at sufficiently large distances from its source through the turbulent atmosphere.

  5. Photocatalytic hydrogen generation over lanthanum doped TiO2 under UV light irradiation.

    PubMed

    Liu, Y; Xie, L; Li, Y; Qu, J L; Zheng, J; Li, X G

    2009-02-01

    TiO2 nanoparticles doped with different amount of lanthanum were obtained by sol-gel approach and followed annealing at different temperature. The crystal size of TiO2 doped with lanthanum was smaller than that of pure TiO2. Photocatalytic activity of TiO2 doped with lanthanum for water splitting into H2 was investigated. The photocatalytic activity of TiO2 doped with lanthanum for water splitting into H2 is higher than that of pure TiO2. It was found that the optimal photocatalyst was TiO2 doped with 2 wt% lanthanum and calcined at 600 degrees C for 4 h which had hydrogen generation rate 700.6 micromol h(-1).

  6. Excited states, generation of light, and photoprocesses in series of complex N, O, S polyatomic molecules

    NASA Astrophysics Data System (ADS)

    Obukhov, Alexandr E.

    1995-01-01

    The photophysical properties of some new and also some known complex organic molecules emission and generated radiations in the wavelength interval 340 - 560 nm have been studied in a wide range of organic solvent. Specifically, these molecules are based on phenyl, furyl-, thienyl-oxazoles and oxadiazoles to compile a quasihomological series. Using the measured values of the extinction (epsilonabs(nu )), the fluorescence quantum yields ((gamma) ), and the fluorescence lifetime ((tau) ), we calculated rate constants for radiative decay (Kfl), and intercombination conversion (KST), along with the cross sections for absorption ((sigma) 13max), and stimulated emission ((sigma) 31osc). We also found the longest pump-pulse rise time (tlp) for which generate of oscillations active molecules. A broad spectrum of singlet and triplet electronic states using the semiempirical SCF MO LCAO method (Parr-Pariser-Pople, PPP/CI, a model approximation of (pi) - electrons) and the complete and incomplete neglecting of differential overlap (CNDO/S-CI and INDO/S-CI, sp-electronic basis). In this paper, the photophysical parameters (gamma) , (tau) , (sigma) 31osc, (sigma) 3S*, (sigma) 2T*, tlp, Kfl, KST, Elp (the threshold of the pump energy density) in the quasi-gomologicals series of complex active molecules are treated as depending on the structural factors in different ways. The physical mechanism responsible for the improvement in the photophysical properties of the mono-, three- and pentacyclic phenyl-, furyl-, and thienylbisoxazoles and oxadiazoles is established. The improvement is observed in the case when the separation of the bands of emission ((sigma) 31osc) and induced absorption on the S1* yields Sn* ((sigma) 3S*) and T1 yields Tn ((sigma) 2T*) transitions is maximum.

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

    NASA Astrophysics Data System (ADS)

    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 (< 1% relative humidity) to (1) elevated 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

  8. Role of nonlinear refraction in the generation of terahertz field pulses by light fields

    SciTech Connect

    Zabolotskii, A. A.

    2013-07-15

    The generation of microwave (terahertz) pulses without any envelope in a four-level quasi-resonant medium is considered. Two intense quasi-monochromatic laser fields lead to a partial upper-level population. Microwave field pulses cause the transition between these levels. For appropriately chosen scales, the evolution of the fields is shown to be described by the pseudo-spin evolution equations in a microwave field with the inclusion of nonlinear refraction caused by an adiabatic upper-level population. The evolution of terahertz field pulses is described outside the scope of the slow-envelope approximation. When a number of standard approximations are taken into account, this system of equations is shown to be equivalent to an integrable version of the generalized reduced Maxwell-Bloch equations or to the generalized three-wave mixing equations. The soliton solution found by the inverse scattering transform method is used as an example to show that nonlinear refraction leads to a strong compression of the microwave (terahertz) field soliton.

  9. Optical element for full spectral purity from IR-generated EUV light sources

    NASA Astrophysics Data System (ADS)

    van den Boogaard, A. J. R.; Louis, E.; van Goor, F. A.; Bijkerk, F.

    2009-03-01

    Laser produced plasma (LLP) sources are generally considered attractive for high power EUV production in next generation lithography equipment. Such plasmas are most efficiently excited by the relatively long, infrared wavelengths of CO2-lasers, but a significant part of the rotational-vibrational excitation lines of the CO2 radiation will be backscattered by the plasma's critical density surface and consequently will be present as parasitic radiation in the spectrum of such sources. Since most optical elements in the EUV collecting and imaging train have a high reflection coefficient for IR radiation, undesirable heating phenomena at the resist level are likely to occur. In this study a completely new principle is employed to obtain full separation of EUV and IR radiation from the source by a single optical component. While the application of a transmission filter would come at the expense of EUV throughput, this technique potentially enables wavelength separation without loosing reflectance compared to a conventional Mo/Si multilayer coated element. As a result this method provides full spectral purity from the source without loss in EUV throughput. Detailed calculations on the principal of functioning are presented.

  10. Phenol degradation in heterogeneous system generating singlet oxygen employing light activated electropolymerized phenothiazines

    NASA Astrophysics Data System (ADS)

    Piwowar, Katarzyna; Blacha-Grzechnik, Agata; Bernas, Paulina; Zak, Jerzy

    2015-12-01

    Five selected amine-derivatives of phenothiazine were electropolymerized on an ITO/glass substrate and then used in the daylight-activated process to produce in situ singlet oxygen which degrades phenol in a solution. The phenothiazines were immobilized in a simple electrochemical procedure in an acidic solution which led to the formation of an ultrathin transparent polymeric film. All films obtained on the ITO substrate including azure A (AA), azure C (AC), methylene blue (MB), toluidine blue (TBO), and thionine (Th) had a comparable surface coverage at the level of picomoles/cm2. The activity of these materials was then compared and presented in terms of an efficiency of the phenol degradation process in an aqueous solution by photogenerated singlet oxygen. That efficiency was determined by the UV-vis spectroscopy employing a phenol/4-aminoantipyrine complex. All the phenothiazine ultrathin polymeric films were capable of generating the singlet oxygen in the aqueous solution under daylight activation, which was used in the consecutive process of phenol degradation. The highest efficiency at a level of 51.4% and 45.4% was found for the AC/ITO and MB/ITO layers, respectively.

  11. [A development of Byzantine Christian charities during the 4(th)-7(th) centuries and the birth of the hospital].

    PubMed

    Nam, Sung Hyun

    2015-04-01

    This study aims to examine the beginning and the development of Christian Charities during the 4(th)-6(th) centuries which would eventually result in the birth of the hospital in modern sense in the first half of the 7(th) century. For this purpose, I looked carefully into various primary sources concerning the early Christian institutions for the poor and the sick. Above all, it's proper to note that the first xenodocheion where hospitality was combined with a systematic caring, is concerned with the Trinitarian debate of the 4(th) century. In 356, Eustathios, one of the leaders of homoiousios group, established xenodocheion to care for the sick and the lepers in Sebaste of Armenia, whereas his opponent Aetios, doctor and leader of the heteroousios party, was reckoned to have combined the medical treatment with his clerical activities. Then, Basil of Caesarea, disciple of Eustathios of Sebaste, also founded in 372 a magnificent benevolent complex named 'Basileias' after its founder. I scrupulously analysed several contemporary materials mentioning the charitable institution of Caesarea which was called alternatively katagogia, ptochotropheion, xenodocheion. John Chrysostome also founded several nosokomeia in Constantinople at the end of the 4(th) century and the beginning of the 5(th) century. Apparently, the contemporary sources mention that doctors existed for these Charities, but there is no sufficient proof that these 'Christian Hospitals,' Basileias or nosokomeia of Constantinople were hospitals in modern sense. Imperial constitutions began to mention ptochotropheion, xenodocheion and orphanotropheion since the second half of the 5(th) century and then some Justinian laws evoked nosokomium, brephotrophia, gerontocomia. These laws reveal that 'Christian Hospitals' were well clarified and deeply rooted in Byzantine society already in these periods. And then, new benevolent institutions emerged in the 6(th) century: nosokomeia for a specific class and

  12. Overcoming CD4 Th1 Cell Fate Restrictions to Sustain Antiviral CD8 T Cells and Control Persistent Virus Infection.

    PubMed

    Snell, Laura M; Osokine, Ivan; Yamada, Douglas H; De la Fuente, Justin Rafael; Elsaesser, Heidi J; Brooks, David G

    2016-09-20

    Viral persistence specifically inhibits CD4 Th1 responses and promotes Tfh immunity, but the mechanisms that suppress Th1 cells and the disease consequences of their loss are unclear. Here, we demonstrate that the loss of CD4 Th1 cells specifically leads to progressive CD8 T cell decline and dysfunction during viral persistence. Therapeutically reconstituting CD4 Th1 cells restored CD4 T cell polyfunctionality, enhanced antiviral CD8 T cell numbers and function, and enabled viral control. Mechanistically, combined interaction of PD-L1 and IL-10 by suppressive dendritic cell subsets inhibited new CD4 Th1 cells in both acute and persistent virus infection, demonstrating an unrecognized suppressive function for PD-L1 in virus infection. Thus, the loss of CD4 Th1 cells is a key event leading to progressive CD8 T cell demise during viral persistence with important implications for restoring antiviral CD8 T cell immunity to control persistent viral infection.

  13. Optical generation of a spatially variant two-dimensional lattice structure by using a phase only spatial light modulator

    SciTech Connect

    Kumar, Manish Joseph, Joby

    2014-08-04

    We propose a simple and straightforward method to generate spatially variant lattice structures by optical interference lithography method. Using this method, it is possible to independently vary the orientation and period of the two-dimensional lattice. The method consists of two steps which are: numerical synthesis of corresponding phase mask by employing a two-dimensional integrated gradient calculations and experimental implementation of synthesized phase mask by making use of a phase only spatial light modulator in an optical 4f Fourier filtering setup. As a working example, we provide the experimental fabrication of a spatially variant square lattice structure which has the possibility to guide a Gaussian beam through a 90° bend by photonic crystal self-collimation phenomena. The method is digitally reconfigurable, is completely scalable, and could be extended to other kind of lattices as well.

  14. Dynamic generation of robust and controlled beating signals in an asymmetric procedure of light storage and retrieval.

    PubMed

    Bao, Qian-Qian; Gao, Jin-Wei; Cui, Cui-Li; Wang, Gang; Xue, Yan; Wu, Jin-Hui

    2011-06-06

    We propose an efficient scheme for the robust and controlled generation of beating signals in a sample of stationary atoms driven into the tripod configuration. This scheme relies on an asymmetric procedure of light storage and retrieval where the two classical coupling fields have equal detunings in the storage stage but opposite detunings in the retrieval stage. A quantum probe field, incident upon such an atomic sample, is first transformed into two spin coherence wave-packets and then retrieved with two optical components characterized by different time-dependent phases. Therefore the retrieved quantum probe field exhibits a series of maxima and minima (beating signals) in intensity due to the alternative constructive and destructive interference. This interesting phenomenon involves in fact the coherent manipulation of two dark-state polaritons and may be explored to achieve the fast quantum limited measurement.

  15. A non-iterative technique for determination of solar cell parameters from the light generated I-V characteristic

    NASA Astrophysics Data System (ADS)

    Kumar, Gaurav; Panchal, Ashish K.

    2013-08-01

    Accurate information about electrical parameters of a photovoltaic (PV) cell is many times essential for evaluating the performance of the cell when delivering power at its full capacity. This paper presents a technique for determining the cell parameters from the light generated current-voltage (I-V) characteristic with a valid assumption for any kind of cells. The technique neither involves any initial approximations nor iteration processes. The technique is employed for various PV cell technologies such as silicon, copper indium gallium selenide, organic, dye sensitized solar cell, and organic tandem cells, previously available in the literatures. Obtained I-V characteristics for the cells using the present technique are in well agreement with those of reported in the literature. The technique is further extended for the analysis of a silicon cell and a silicon module tested in the laboratory and the results obtained are very close to those of the experimental data.

  16. Generation of light-induced electrical potential from ion exchange membranes containing 4,4{prime}-bipyridine moiety

    SciTech Connect

    Sata, Toshikatsu

    1996-07-15

    Ion exchange membranes, which are some of the most advanced separation membranes, are widely used in industry, i.e., in electrodialysis processes, diffusion dialysis processes, as separators for electrolysis, solid polyelectrolytes for fuel cells, etc. Generation of photovoltage and photocurrent from ion exchange membranes containing a viologen moiety was examined, cation exchange membranes ion-exchanged with methyl viologen and anion exchange membranes to which a viologen moiety was bonded. After the membrane, swelled with ethylene glycol, had been clamped between two ITO electrodes and sealed, it was irradiated with a xenon lamp. In the case of the cation exchange membranes ion-exchanged with methyl viologen, 155.3 mV of photo-voltage was observed immediately after photoirradiation, and the voltage decreased and attained almost a constant value. The photovoltage of anion exchange membranes with the viologen moiety increased very slowly (maximum 81 mV, 405 nA; load resistance 200 K{Omega}) after beginning the irradiation. However, when the light was irradiated again on the membrane after interruption of the irradiation, almost the same photovoltage was generated immediately after the irradiation. Though the anion exchange membrane showed absorbance only at 320 nm in the UV-VIS spectrum, wavelengths between 300 and 400 nm were active to reduce the viologen moiety of the membrane. This might be due to a polymer effect. On the other hand, the electrical resistance between the ITO electrodes decreased upon photoirradiation because of radical formation. In order to accelerate generation of the voltage, an oxidative agent (ferric ions) or a reductive agent (triethanolamine) was added to the system. The photovoltage was generated immediately after irradiation in both cases. Ferric ions act as an electron acceptor and triethanolamine forms cation radicals in the membrane before the irradiation.

  17. Generations.

    PubMed

    Chambers, David W

    2005-01-01

    Groups naturally promote their strengths and prefer values and rules that give them an identity and an advantage. This shows up as generational tensions across cohorts who share common experiences, including common elders. Dramatic cultural events in America since 1925 can help create an understanding of the differing value structures of the Silents, the Boomers, Gen Xers, and the Millennials. Differences in how these generations see motivation and values, fundamental reality, relations with others, and work are presented, as are some applications of these differences to the dental profession.

  18. Next-generation high-reliability laser light engine by glass phosphor-converted layer (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Chang, Yung-Peng; Chang, Jin-Kai; Cheng, Wei-Chih; Liu, Chun-Nien; Chen, Li-Yin; Cheng, Wood-Hi

    2016-09-01

    A new scheme of high-reliability laser light engine (LLE) employing a novel glass-based phosphor-converted layer is proposed and demonstrated. The LLE module consists of a high-power blue light laser array and a color wheel, which includes two glass-based phosphor-converted layers of yellow Ce:YAG and green Ce:LuAG and a micro motor. The combinations of blue, yellow, and green lights produce high-purity phosphor-converted white-laser-diodes (PC-WLDs). The lumen degradation and chromaticity shift in the glass-based phosphor-converted layer under different laser powers are presented and compared with those of silicon-based PC-WLDs. The results showed that the glass based PC-WLDs exhibited in lower lumen loss and less chromaticity shifts than the silicon-based PC-WLDs. The long term reliability study evaluation in glass- and silicone-based PC-WLDs under high-power 120 W at room temperature for 20,000 hours is also presented and compared. The result showed that the silicone-based PC-WLDs exhibited 50% in lumen decay which failed in operation, while the glass-based PC-WLDs only exhibited 2% in lumen decay. This indicates that the proposed LLE modules are benefit to employ in the area where the silicone-based material fails to stand for long and strict reliability is highly required. This study demonstrates the advantages of adapting novel glass as a phosphor-converted color wheel in the LLE modules that provide unique high-reliability as well as better performance for use in the next-generation laser projector system.

  19. Solid-core and hollow-core photonic crystal fiber for generation of bright ultraviolet light (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Joly, Nicolas Y.; Jiang, Xin; Travers, John C.; Ermolov, Alexey; Russell, Philip S.

    2016-09-01

    Over the last two decades the interest in photonic crystal fiber (PCF) has grown considerably, particularly in nonlinear optics where it allows enhanced control over the dispersion landscape. Although silica is the material most commonly used to fabricate PCF, its limited window of transmission and its susceptibility to optical damage at wavelengths below 350nm is driving the development of fibers made from glasses with transmission windows extending into the deep ultraviolet and the mid-infrared. An alternative is offered by gas-filled hollow-core fiber, in which the light propagates predominantly in the gas. In kagomé-style hollow-core PCF filled with noble gas, the weak anomalous dispersion of the empty fiber is balanced by the normal dispersion of the filling gas, resulting in a versatile system whose dispersion landscape can be adjusted in real time [Travers et al., JOSAB 28, A11 (2011)]. Under appropriate conditions the launched pulse undergoes soliton self-compression followed by emission of a band of dispersive radiation in the UV. UV light tunable down to 113 nm has been generated with this technique [Russell et al., Nat. Photon. 8, 278 (2014)]. Solid-core ZBLAN (fluorozirconate) glass PCF is transparent from 0.2 to 7.8µm. Launching 1nJ 140fs pulses at 1µm wavelength into a 1µm diameter core resulted, after 4cm of propagation, in generation of a supercontinuum spectrum extending from 210nm to beyond 2µm. In strong contrast to silica PCF, the ZBLAN PCF showed no signs of any solarization-related damage, even when operating over many hours [Jiang et al., Nat. Photon. 9, 133 (2015)].

  20. Design and analysis of single-mode tellurite photonic crystal fibers for stimulated Brillouin scattering based slow-light generation.

    PubMed

    Jain, Varsha; Sharma, Shubham; Saini, Than Singh; Kumar, Ajeet; Sinha, Ravindra Kumar

    2016-09-01

    We theoretically examine two designs of single-mode (i) Er-doped tellurite and (ii) undoped tellurite photonic crystal fiber (PCF) for generation of slow light with tunable features based on stimulated Brillouin scattering. We obtained (i) Brillouin gain up to 91 dB and time delay of ∼145  ns at maximum allowable pump power of ∼775  mW in a 2 m Er-doped tellurite PCF and (ii) Brillouin gain up to ∼88  dB and time delay of ∼154  ns at maximum allowable pump power ∼21  mW in a 100 m undoped tellurite photonic crystal fiber. Simulated results clearly indicate that the doped tellurite PCF with Er enhances the maximum allowable pump power and comparable time delay can be obtained even with reduced photonic crystal fiber length. We believe that the carried out examination and simulation have potential impact on design and development of slow-light-based photonic devices applicable in telecommunication systems, enhancement of optical forces, and quantum computing.

  1. The St. Jude Cancer Education for Children Program Pilot Study: Determining the Knowledge Acquisition and Retention of 4th-Grade Students.

    PubMed

    Ayers, Katherine; Villalobos, Aubrey Van Kirk; Li, Zhenghong; Krasin, Matthew

    2016-03-01

    In 2006, St. Jude Children's Research Hospital began developing a school-based outreach program known as the St. Jude Cancer Education for Children Program (SJCECP). The program aimed to teach children about cancer and healthy habits that can prevent the formation of cancers into adulthood. During the 2010-2011 academic years, we conducted a pilot evaluation of the SJCECP curriculum, with the primary objective of evaluating the impact of the intervention on knowledge acquisition and retention among 4th-grade students participating in the program. Seven local schools and 481 students from the Memphis area participated in the program evaluation. The results of this study show that 4th-grade students are able to acquire gains in knowledge related to cells, cancer, and healthy living after receiving the SJCECP intervention. We conclude that the program can be a useful tool for improving knowledge of cancer concepts at the 4th-grade level.

  2. Quality of Education Predicts Performance on the Wide Range Achievement Test-4th Edition Word Reading Subtest

    PubMed Central

    Sayegh, Philip; Arentoft, Alyssa; Thaler, Nicholas S.; Dean, Andy C.; Thames, April D.

    2014-01-01

    The current study examined whether self-rated education quality predicts Wide Range Achievement Test-4th Edition (WRAT-4) Word Reading subtest and neurocognitive performance, and aimed to establish this subtest's construct validity as an educational quality measure. In a community-based adult sample (N = 106), we tested whether education quality both increased the prediction of Word Reading scores beyond demographic variables and predicted global neurocognitive functioning after adjusting for WRAT-4. As expected, race/ethnicity and education predicted WRAT-4 reading performance. Hierarchical regression revealed that when including education quality, the amount of WRAT-4's explained variance increased significantly, with race/ethnicity and both education quality and years as significant predictors. Finally, WRAT-4 scores, but not education quality, predicted neurocognitive performance. Results support WRAT-4 Word Reading as a valid proxy measure for education quality and a key predictor of neurocognitive performance. Future research should examine these findings in larger, more diverse samples to determine their robust nature. PMID:25404004

  3. A study of personality factors and interaction in 4th-year dental students and their teachers.

    PubMed

    Watts, T L; Millard, L

    1997-02-01

    No previous investigation has considered dental student and teaching staff opinions on their relationship with each other. In a day when students are increasingly asked for feedback on the quality of teaching by staff, such investigations are of particular interest. This exploratory study was designed to compare the personality characteristics of a clinical year of dental students with those of the teaching staff they most frequently encountered, and to investigate these factors for possible associations with the quality of perceived teaching-learning interaction between the 2 groups. A complete 4th year of dental students (n = 87), and those teachers whom they met regularly (n = 80), were asked to participate. Subjects completed a form of the Myers-Briggs personality questionnaire simplified for use in education, and were asked to assess their relationship with persons in the other group. All the students and 75% of the staff, after follow-up, returned usable data. There was close similarity between staff and student personality profiles, and perception of working relationships by both groups was largely independent of personality factors and temperament. There were differences in staff perception of their relationship with extrovert and introvert students. Students showed minor differences in their perception of staff relationships with respect to two other personality factors. These findings indicate a substantial similarity between staff and students, and suggest a mature and stable relationship between people in the 2 groups.

  4. 4th International Meeting on Single Nucleotide Polymorphism and Complex Genome Analysis. Various uses for DNA variations.

    PubMed

    Brookes, Anthony J

    2002-02-01

    At the 4th International Meeting on Single Nucleotide Polymorphism and Complex Genome Analysis (Stockholm, Sweden, 10th-14th October 2001), approximately 100 scientists from more than 20 nations undertook a probing review of latest developments in the field. Despite impressive and still ongoing activities towards SNP discovery and validation, plus efforts towards haplotype exploitation, it was clear that supporting technologies for genotyping are way behind where they need to be. Innate complexity and large variances in aspects of genome function together pose immense challenges that are difficult to surmount in the human situation. In contrast, studies in simpler organisms and population/evolutionary genetics studies are yielding important new insights. Breakthroughs that are being made in understanding the genetic etiology of complex disease tend to involve genes of larger effect or extremely well merited candidates. Linkage studies and proximal phenotypes are being recommended, though the best way forward is still hotly debated. Consequently, many diverse and ambitious projects are underway, from which the data itself will eventually show what is and is not possible.

  5. [Experience with percutaneous endoscopic gastrostomy in the nutrition of a patient with 3rd and 4th degree facial burns].

    PubMed

    Halmy, C; Szücs, A; Gyökeres, T; Dékány, K; Mezeine, T I; Kertész, E

    1998-05-17

    Recovery after thermal injury depends in great proportion on nutrition. A major problem is accounted in patients with facial burn, because they can not be nourished per vias naturales. Eliminating disadvantages of parenteral nutrition, but utilizing the advantages of enteral nutrition, we have tried a new method of treatment in a patient whose case is presented. On the second day after injury a percutaneous endoscopic gastrostomy was made. On the 7th day after injury and on the 4th day from the beginning of enteral nutrition complete intake of food and liquid was assured through the percutaneous endoscopic gastrostoma. We had no complication related to the gastrostoma. Nutrition through the percutaneous endoscopic gastrostoma at our patient provided a "natural" route to assure liquid, electrolite and energy balance, prevented atrophy of intestinal mucosa and its metabolic and immunologic complications. With the use of percutaneous endoscopic gastrostoma the possible complications of central line catheter were omitted. Our opinion is that percutaneous endoscopic gastrostomy is a safe and effective method for the clinical nutrition of burned patients.

  6. Identification of DRG-1 As a Melanoma-Associated Antigen Recognized by CD4+ Th1 Cells

    PubMed Central

    Kiniwa, Yukiko; Li, Jiang; Wang, Mingjun; Sun, Chuang; Lee, Jeffrey E.; Wang, Rong-Fu; Wang, Helen Y.

    2015-01-01

    Immunotherapy has emerged as a promising strategy for the treatment of metastatic melanoma. Clinical studies have demonstrated the feasibility of cancer immunotherapy using tumor antigens recognized by CD8+ T cells. However, the overall immune responses induced by these antigens are too weak and transient to induce tumor regression in the majority of patients who received immunization. A growing body of evidence suggests that CD4+ T helper (Th) cells play an important role in antitumor immunity. Therefore, the identification of MHC class II-restricted tumor antigens capable of stimulating CD4+ T cells may provide opportunities for developing effective cancer vaccines. To this end, we describe the identification of developmentally regulated GTP-binding protein 1 (DRG-1) as a melanoma-associated antigen recognized by HLA-DR11-restricted CD4+ Th1 cells. Epitope mapping analysis showed that the DRG1248-268 epitope of DRG-1 was required for T cell recognition. Reverse transcription-polymerase chain reaction revealed that DRG-1 was highly expressed in melanoma cell lines but not in normal tissues. DRG-1 knockdown by lentiviral-based shRNA suppressed melanoma cell proliferation and soft agar colony formation. Taken together, these data suggest that DRG-1 plays an important role in melanoma cell growth and transformation, indicating that DRG1 may represent a novel target for CD4+ T cell-mediated immunotherapy in melanoma. PMID:25993655

  7. Update from the 4th Edition of the World Health Organization Classification of Head and Neck Tumours: Odontogenic and Maxillofacial Bone Tumors.

    PubMed

    Wright, John M; Vered, Marilena

    2017-03-01

    The 4th edition of the World Health Organization's Classification of Head and Neck Tumours was published in January of 2017. This article provides a summary of the changes to Chapter 4 Tumours of the oral cavity and mobile tongue and Chapter 8 Odontogenic and maxillofacial bone tumours. Odontogenic cysts which were eliminated from the 3rd 2005 edition were included in the 4th edition as well as other unique allied conditons of the jaws. Many new tumors published since 2005 have been included in the 2017 classification.

  8. Comparative cytotoxicity and ROS generation by curcumin and tetrahydrocurcumin following visible-light irradiation or treatment with horseradish peroxidase.

    PubMed

    Atsumi, Toshiko; Tonosaki, Keiichi; Fujisawa, Seiichiro

    2007-01-01

    In order to clarify the cytotoxic mechanism of curcumin, a well-known chemopreventive agent, the cytotoxicity (by MTT method), intracellular glutathione (using GSH detection kit) and intracellular reactive oxygen species (ROS) levels (with a flow cytometer), were measured in curcumin- and tetrahydrocurcumin (TH-curcumin)-treated cancer (HSG) and normal (HGF) cells under two different oxidation conditions: irradiation with visible light (VL) and enzymatic oxidation with horseradish peroxidase (HRP)/H2O2. The cytotoxicity of curcumin was highly enhanced by VL-irradiation, whereas that of TH-curcumin was enhanced by HRP/H2O2 treatment. The cytotoxicity of curcumin against HGF cells was greater than that against HSG cells. Curcumin significantly reduced the intracellular GSH level significantly under VL-irradiation, and increased it under HRP/H2O2, whereas TH-curcumin had no effect with either oxidation treatment. HRP/H2O2 treatment of TH-curcumin enhanced generation of ROS; in contrast, VL-irradiation of curcumin was considered to produce ROS preferably. In conclusion, curcumin was highly photo-toxic, caused a decrease in GSH and mediated ROS generation. In contrast, the cytotoxicity of TH-curcumin was enhanced by enzymatic oxidation. A low-level pro-oxidant intracellular milieu induced by TH-curcumin could be effectively useful for cancer prevention.

  9. Benefits of a 4th Ice Class in the Simulated Radar Reflectivities of Convective Systems Using a Bulk Microphysics Scheme

    NASA Technical Reports Server (NTRS)

    Lang, Stephen E.; Tao, Wei-Kuo; Chern, Jiun-Dar; Wu, Di; Li, Xiaowen

    2015-01-01

    Numerous cloud microphysical schemes designed for cloud and mesoscale models are currently in use, ranging from simple bulk to multi-moment, multi-class to explicit bin schemes. This study details the benefits of adding a 4th ice class (hail) to an already improved 3-class ice bulk microphysics scheme developed for the Goddard Cumulus Ensemble model based on Rutledge and Hobbs (1983,1984). Besides the addition and modification of several hail processes from Lin et al. (1983), further modifications were made to the 3-ice processes, including allowing greater ice super saturation and mitigating spurious evaporationsublimation in the saturation adjustment scheme, allowing graupelhail to become snow via vapor growth and hail to become graupel via riming, and the inclusion of a rain evaporation correction and vapor diffusivity factor. The improved 3-ice snowgraupel size-mapping schemes were adjusted to be more stable at higher mixing rations and to increase the aggregation effect for snow. A snow density mapping was also added. The new scheme was applied to an intense continental squall line and a weaker, loosely-organized continental case using three different hail intercepts. Peak simulated reflectivities agree well with radar for both the intense and weaker case and were better than earlier 3-ice versions when using a moderate and large intercept for hail, respectively. Simulated reflectivity distributions versus height were also improved versus radar in both cases compared to earlier 3-ice versions. The bin-based rain evaporation correction affected the squall line case more but did not change the overall agreement in reflectivity distributions.

  10. [Level of smoking of 3rd and 4th grade students studying health and related factors: follow-up study].

    PubMed

    Göktalay, Tuğba; Cengiz Özyurt, Beyhan; Sakar Coşkun, Ayşin; Celik, Pinar

    2011-01-01

    The levels of smoking of 1st and 2nd year students at Faculty of Medicine and Manisa School of Health at Celal Bayar University were investigated in 2006-2007. This study is carried out in order to see if there is a change in the same students' level of smoking while they are in 3rd and 4th year. In addition, the study aimed to examine the factors affecting the level of use and attitudes towards the law effectuated in July 19, 2009. This is a follow-up study with 80.42% return rate. A 26-item structured questionnaire was administered. The participants filled out the questionnaires under supervision of the researchers in their classrooms. The University Institutional Review Board approved the study. The total of participants (263) of the follow-up study included 189 female and 74 male. The rate of experimenting with smoking was 49% with the mean age of 15.7 (SD= 4.01 years). The mean age of experimenting with smoking was the earliest on male students studying at faculty of medicine. The level of smoking was found to be the most on females, studying at faculty of medicine and staying at the dormitory, with smoking parents (p< 0.05). The most important reason to begin smoking was curiosity (55.2%) while bad breath and yellowing of teeth were the reasons to quit (91.7%). 83.3% of the students thought that the law will be effective on quit smoking. The level of both experimenting and use of smoking has been increased over time. It is suggested that medical students' awareness about the danger of smoking should be raised at earlier grades. In addition, lectures should be offered to students at School of Health and they should be encouraged to unite in order to fight with smoking.

  11. Visible light-driven photocatalytic H{sub 2}-generation activity of CuS/ZnS composite particles

    SciTech Connect

    Xiao, Liang; Chen, Hua; Huang, Jianhua

    2015-04-15

    Highlights: • Preparation of CuS/ZnS composite photocatalyst by cation-exchange reaction. • Visible light photocatalytic activity for H{sub 2} evolution without cocatalyst. • The H{sub 2}-evolution rate from water splitting depends on the CuS content. • The highest rate of H{sub 2} evolution is obtained with CuS (0.5 mol%)/ZnS composite. - Abstract: CuS/ZnS composite particles with diameter of 200–400 nm were successfully prepared by a simple cation-exchange reaction using ZnS spheres as a precursor. CuS nanoparticles with a few nanometers in diameter were observed on the surface of composite particles. The synthesized CuS/ZnS composite particles showed photocatalytic property effective for H{sub 2} evolution from an aqueous Na{sub 2}S and Na{sub 2}SO{sub 3} solution under visible light irradiation without any cocatalysts. The rate of H{sub 2} generation was found to be strongly dependent on the CuS content. The highest rate of H{sub 2} evolution reached 695.7 μmol h{sup −1} g{sup −1}, which was almost 7 times as high as that of the mechanical mixture of CuS and ZnS. The enhancement in the photocatalytic activity of CuS/ZnS composite particles is supposed to be due to the direct interfacial charge transfer of the CuS/ZnS heterojunction.

  12. 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

    PubMed Central

    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. PMID:28144440

  13. Generation of ultrabroadband femtosecond pulses in the mid-infrared by optical rectification of 15 fs light pulses at 100 MHz repetition rate

    NASA Astrophysics Data System (ADS)

    Bonvalet, A.; Joffre, M.; Martin, J. L.; Migus, A.

    1995-11-01

    Quasi-single-cycle near-infrared light pulses with a measured spectrum extending from 7 to 15 μm have been generated, opening up new perspectives in IR spectroscopy. The method is based on the rectification of 0.8 μm 10-15 fs light pulses from a 100 MHz oscillator, using the instantaneous second-order polarizability of bulk semiconductors such as GaAs.

  14. Field Responses of Anopheles gambiae Complex (Diptera: Culicidae) in Liberia using Yeast-Generated Carbon Dioxide and Synthetic Lure-Baited Light Traps

    DTIC Science & Technology

    2013-07-01

    VECTOR-BORNE DISEASES, SURVEILLANCE, PREVENTION Field Responses of Anopheles gambiae Complex (Diptera: Culicidae) in Liberia using Yeast-Generated...and light, bed-net, tent, andodor-baited traps (Mboera 2005). TheCenters forDiseaseControl and Prevention (CDC) light trap with its typical 4Ð6 W...using paper- clips. Although primarily developed and used to attract day ßying Stegomyia ( Aedes ) mosquitoes, blends of this lureÕs primary ingredients

  15. 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.

    PubMed

    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.

  16. Meeting Materials for the 4th NRC Meeting on the Guidance for and the Review of EPA's Toxicological Assessment of Inorganic Arsenic

    EPA Science Inventory

    On December 2-3, 2015, the National Research Council (NRC) hosted the 4th meeting of the committee formed to peer review the draft IRIS assessment of inorganic arsenic. EPA presented background and overview materials during the public session on December 2nd. This information co...

  17. The Attitude of the Students towards the Value of "Paying Attention to Being Healthy" in 4th Grade Elementary Social Sciences Course

    ERIC Educational Resources Information Center

    Tahiroglu, Mustafa; Cetin, Turhan

    2012-01-01

    This study was aimed to define the teaching of the value of "Paying Attention to Being Healthy" in 4th grade elementary Social Sciences course and to determine the students' attitude towards this value. To reach this goal, activities to teach the value of paying attention to being healthy were prepared and conducted. The effect of these…

  18. Autism: Proceedings of Annual Meeting of the National Society for Autistic Children (4th, June 22-24, 1972, Flint Michigan).

    ERIC Educational Resources Information Center

    National Society for Autistic Children, Syracuse, NY.

    Presented are proceedings of the 4th annual (1972) meeting of the National Society for Autistic Children including 11 papers given at the meeting. Listed are officers and board members of the society, the convention committee members, and recipients of citations and awards. The president's report notes past goals, accomplishments, and future…

  19. The Effect of Direct Instruction Strategy on Math Achievement of Primary 4th and 5th Grade Students with Learning Difficulties

    ERIC Educational Resources Information Center

    Al-Makahleh, Ahmad Abdulhameed Aufan

    2011-01-01

    This study seeks to verify the effect of direct instruction strategy on Math achievment of students with learning difficulties in the fourth and fifth grade levels and measure the improvement in their attitudes to Mathematics. Sample consisted of sixty (60) students with Math learning difficulties attending 4th and 5th grade level resource rooms…

  20. U.S. Dietary and Physical Activity Guideline Knowledge and Corresponding Behaviors among 4th and 5th Grade Students: A Multi-Site Pilot Study

    ERIC Educational Resources Information Center

    Bea, Jennifer W.; Martinez, Stephanie; Armstrong-Florian, Traci; Farrell, Vanessa; Martinez, Cathy; Whitmer, Evelyn; Hartz, Vern; Blake, Samuel; Nicolini, Ariana; Misner, Scottie

    2014-01-01

    Knowledge of U.S. dietary and physical activity recommendations and corresponding behaviors were surveyed among 4th and 5th graders in five Arizona counties to determine the need for related education in SNAP-Ed eligible schools. A <70% target response rate was the criterion. Participants correctly identified recommendations for: fruit, 20%;…