WorldWideScience

Sample records for multi-electron photochemistry devices

  1. Photochemistry on solid surfaces

    CERN Document Server

    Matsuura, T

    1989-01-01

    The latest developments in photochemistry on solid surfaces, i.e. photochemistry in heterogeneous systems, including liquid crystallines, are brought together for the first time in a single volume. Distinguished photochemists from various fields have contributed to the book which covers a number of important applications: molecular photo-devices for super-memory, photochemical vapor deposition to produce thin-layered electronic semiconducting materials, sensitive optical media, the control of photochemical reactions pathways, etc. Photochemistry on solid surfaces is now a major field and this

  2. Multi-electron transfer photochemistry: Caught in the act

    Science.gov (United States)

    Beiler, Anna M.; Moore, Gary F.

    2018-01-01

    The accumulation of multiple redox equivalents is essential in photo-driven catalytic reactions such as solar water splitting. However, direct spectroscopic observation of a twice-oxidized species under diffuse illumination has proved elusive until now.

  3. Atmospheric Photochemistry

    Science.gov (United States)

    Massey, Harrie; Potter, A. E.

    1961-01-01

    The upper atmosphere offers a vast photochemical laboratory free from solid surfaces, so all reactions take place in the gaseous phase. At 30 km altitude the pressure has fallen to about one-hundredth of that at ground level, and we shall, rather arbitrarily, regard the upper atmosphere as beginning at that height. By a little less than 100 km the pressure has fallen to 10(exp -3) mm Hg and is decreasing by a power of ten for every 15 km increase in altitude. Essentially we are concerned then with the photochemistry of a nitrogen-oxygen mixture under low-pressure conditions in which photo-ionization, as well as photodissociation, plays an important part. Account must also be taken of the presence of rare constituents, such as water vapour and its decomposition products, including particularly hydroxyl, oxides of carbon, methane and, strangely enough, sodium, lithium and calcium. Many curious and unfamiliar reactions occur in the upper atmosphere. Some of them are luminescent, causing the atmosphere to emit a dim light called the airglow. Others, between gaseous ions and neutral molecules, are almost a complete mystery at this time. Similar interesting phenomena must occur in other planetary atmospheres, and they might be predicted if sufficient chemical information were available.

  4. Photochemistry of Planetary Atmospheres

    Science.gov (United States)

    Yung, Y. L.

    2005-12-01

    The Space Age started half a century ago. Today, with the completion of a fairly detailed study of the planets of the Solar System, we have begun studying exoplanets (or extrasolar planets). The overriding question in is to ask whether an exoplanet is habitable and harbors life, and if so, what the biosignatures ought to be. This forces us to confront the fundamental question of what controls the composition of an atmosphere. The composition of a planetary atmosphere reflects a balance between thermodynamic equilibrium chemistry (as in the interior of giant planets) and photochemistry (as in the atmosphere of Mars). The terrestrial atmosphere has additional influence from life (biochemistry). The bulk of photochemistry in planetary atmospheres is driven by UV radiation. Photosynthesis may be considered an extension of photochemistry by inventing a molecule (chlorophyll) that can harvest visible light. Perhaps the most remarkable feature of photochemistry is catalytic chemistry, the ability of trace amounts of gases to profoundly affect the composition of the atmosphere. Notable examples include HOx (H, OH and HO2) chemistry on Mars and chlorine chemistry on Earth and Venus. Another remarkable feature of photochemistry is organic synthesis in the outer solar system. The best example is the atmosphere of Titan. Photolysis of methane results in the synthesis of more complex hydrocarbons. The hydrocarbon chemistry inevitably leads to the formation of high molecular weight products, giving rise to aerosols when the ambient atmosphere is cool enough for them to condense. These results are supported by the findings of the recent Cassini mission. Lastly, photochemistry leaves a distinctive isotopic signature that can be used to trace back the evolutionary history of the atmosphere. Examples include nitrogen isotopes on Mars and sulfur isotopes on Earth. Returning to the question of biosignatures on an exoplanet, our Solar System experience tells us to look for speciation

  5. Photochemistry research at NREL

    Energy Technology Data Exchange (ETDEWEB)

    Lyons, C.E.; Carlson, C.E. [National Renewable Energy Laboratory, Golden, CO (United States)

    1996-09-01

    Photochemistry research team at NREL conducts research and development work in all R&D areas, basic, applied, demonstration and transfer to commercialization. Basic research includes core PCO R&D and catalysts work as well as conducting research into new photochemistry areas such as photoinduced adsorption and high temperature solar PCO. Applied research work consists of remediation of chloroethylenes in gas phase, gas phase solar photoreactor development, and application research including indoor air quality, hybrid biological/PCO processes and more. We are demonstrating the PCO treatment technology in the gas phase with SEMATECH through CRADA work and remediation of organics in aqueous phase through the Solarchem Environmental Systems. We are working with IT through a CRADA to transfer the PCO gas phase remediation technology to IT to commercialize this promising -technology. Photochemistry research conducted at NREL spans the R&D spectrum from basic research through technology demonstration with the goal of technology commercialization.

  6. Photochemistry of the actinides

    International Nuclear Information System (INIS)

    Toth, L.M.; Bell, J.T.; Friedman, H.A.

    1979-01-01

    It has been found that all three major actinides have a useful variety of photochemical reactions which could be used to achieve a separations process that requires fewer reagents. Several features merit enumerating: (1) Laser photochemistry is not now as uniquely important in fuel reprocessing as it is in isotopic enrichment. The photochemistry can be successfully accomplished with conventional light sources. (2) The easiest place to apply photo-reprocessing is on the three actinides U, Pu, and Np. The solutions are potentially cleaner and more amenable to photoreactions. (3) Organic-phase photoreactions are probably not worth much attention because of the troublesome solvent redox chemistry associated with the photochemical reaction. (4) Upstream process treatment on the raffinate (dissolver solution) may never be too attractive since the radiation intensity precludes the usage of many optical materials and the nature of the solution is such that light transmission into it might be totally impossible

  7. Time ordering in multi-electron dynamics

    International Nuclear Information System (INIS)

    McGuire, J H; Godunov, A L; Shakov, Kh Kh; Shipakov, V A; Merabet, H; Bruch, R; Hanni, J

    2003-01-01

    Time ordering of interactions in dynamic quantum multi-electron systems provides a constraint that interconnects the time evolution of different electrons. In energy space, time ordering appears as the principal value contribution from the Green function, which corresponds to the asymptotic condition that specifies whether the system has outgoing (or possibly incoming) scattered waves. We report evidence of effects of time correlation found by comparing calculations to recent spectropolarimetric data

  8. Time ordering in multi-electron dynamics

    Energy Technology Data Exchange (ETDEWEB)

    McGuire, J H [Department of Physics, Tulane University, New Orleans, LA (United States); Godunov, A L [Department of Physics, Tulane University, New Orleans, LA (United States); Shakov, Kh Kh [Department of Physics, Tulane University, New Orleans, LA (United States); Shipakov, V A [Troitsk Institute for Innovation and Fusion Research, Troitsk (Russian Federation); Merabet, H [Department of Physics, University of Nevada Reno, Reno, NV (United States); Bruch, R [Department of Physics, University of Nevada Reno, Reno, NV (United States); Hanni, J [Department of Physics, University of Nevada Reno, Reno, NV (United States)

    2003-01-28

    Time ordering of interactions in dynamic quantum multi-electron systems provides a constraint that interconnects the time evolution of different electrons. In energy space, time ordering appears as the principal value contribution from the Green function, which corresponds to the asymptotic condition that specifies whether the system has outgoing (or possibly incoming) scattered waves. We report evidence of effects of time correlation found by comparing calculations to recent spectropolarimetric data.

  9. Radiation and photochemistry section

    International Nuclear Information System (INIS)

    1991-01-01

    The highlights of this past year in the Radiation and Photochemistry Section at Argonne include: (1) picosecond optical studies of radical cations and excited states produced in hydrocarbon radiolysis provided the first kinetic measurements of ion transformation and production of triplet and singlet excited states by ion recombination. (2) studies of radical cations of alkyl-substituted amines and sulfides provided insights into ion-molecule reactions of radical cations in the condensed phase. (3) studies of the behavior of strained alkane radical cations, such as cubane + ·, revealed new rearrangements and remarkable, medium-dependent differences in their structures. (4) H·atom reactions yielding e aq - provided the first reliable measurements of hydrated-electron enthalpy and entropy and forced the revision of some previous thinking about the driving force in aq - reactions

  10. Microwave Photochemistry II. Photochemistry of 2-tert-butylphenol

    Czech Academy of Sciences Publication Activity Database

    Církva, Vladimír; Kurfürstová, Jana; Karban, Jindřich; Hájek, Milan

    2004-01-01

    Roč. 168, č. 3 (2004), s. 197-204 ISSN 1010-6030 R&D Projects: GA ČR GA203/02/0879 Institutional research plan: CEZ:AV0Z4072921 Keywords : microwave photochemistry * electrodeless discharge lamp * 2-tert-Butylphenol Subject RIV: CC - Organic Chemistry Impact factor: 2.235, year: 2004

  11. Microwave Photochemistry III. Photochemistry of 4-tert-Butylphenol

    Czech Academy of Sciences Publication Activity Database

    Církva, Vladimír; Kurfürstová, J.; Karban, Jindřich; Hájek, Milan

    2005-01-01

    Roč. 174, č. 1 (2005), s. 38-44 ISSN 1010-6030 R&D Projects: GA ČR(CZ) GA203/02/0879; GA AV ČR(CZ) KSK4040110 Institutional research plan: CEZ:AV0Z40720504 Keywords : microwave photochemistry * electrodeless discharge lamp * 4-tert-Butylphenol Subject RIV: CC - Organic Chemistry Impact factor: 2.286, year: 2005

  12. Flow photochemistry: Old light through new windows

    Directory of Open Access Journals (Sweden)

    Jonathan P. Knowles

    2012-11-01

    Full Text Available Synthetic photochemistry carried out in classic batch reactors has, for over half a century, proved to be a powerful but under-utilised technique in general organic synthesis. Recent developments in flow photochemistry have the potential to allow this technique to be applied in a more mainstream setting. This review highlights the use of flow reactors in organic photochemistry, allowing a comparison of the various reactor types to be made.

  13. Vacuum ultraviolet photochemistry of polymers

    International Nuclear Information System (INIS)

    Skurat, Vladimir

    2003-01-01

    The interaction of vacuum UV radiation (wavelength range from 1 to 200 nm) with polymers is interesting for fundamental and applied sciences. This interest is stimulated by various reasons: - Wide applications of polymeric materials in semiconductor technology, where they are used as photoresist materials in combination with VUV light sources (lasers, excimer lamps, synchrotron radiation and others). - Polymers are widely used as spacecraft materials in the last 20 years. On near-Earth orbits, the polymeric materials of spacecraft surfaces are destroyed by solar radiation. - VUV radiation is one of the components of gas discharge plasmas, which are used for treatment of polymer, with the aim of modifying their surface properties. The main features of interaction of VUV radiation with polymers are discussed. The spectra of intrinsic absorption of saturated polymers (polyethylene, polypropylene, polytetrafluoroethylene and others) are situated mainly in the VUV region. The photochemistry of polymers in the VUV region is very different from their photochemistry at wavelengths longer than 200 nm, where the absorption spectra belong to impurities and polymer defects. The polymer photochemistry in the VUV region is wavelength-dependent. At wavelengths longer than about 140 nm, the main role is played by transformations of primary-formed singlet excited molecules. At shorter wavelengths the role of photoionization increases progressively and the main features of VUV photolysis become similar to the picture of radiolysis, with significant contributions of charge pairs and triplet excited molecules. Very important features of VUV light absorption in polymers are high absorption coefficients. Because of this, the surface layers absorb large doses of energy. This leads to very profound transformation of material on the polymer surface. In particular for polymers which are considered destroyed by radiation (for example, perfluoropolymers), this leads to VUV-induced erosion

  14. Quantum Hall Effect: proposed multi-electron tunneling experiment

    International Nuclear Information System (INIS)

    Kostadinov, I.Z.

    1985-11-01

    Here we propose a tunneling experiment for the fractional and Integral Quantum Hall Effect. It may demonstrate multi-electron tunneling and may provide information about the nature of the macroscopic quantum states of 2D electronic liquid or solid. (author)

  15. The photochemistry of the paleoatmosphere

    Science.gov (United States)

    Levine, J. S.

    1982-01-01

    Recent progress in the understanding of the chemistry and photochemistry of the paleoatmosphere is reviewed with emphasis on the application of photochemical models to the investigation of the evolution of the atmosphere. Photochemical calculations are presented which show that a primordial highly reducing atmosphere composed of methane and ammonia, if it formed at all, would be short-lived in the presence of solar ultraviolet radiation, giving way rapidly to a more mildly reducing atmosphere of carbon dioxide and nitrogen. Estimations of O2 produced from the photolysis of water vapor prior to the emergence of photosynthesis range from less than 10 to the -14th to 0.1 times the present atmospheric level, indicating the need for further research. A series of photochemical models of increasing complexity has been developed to study the evolution of atmospheric ozone taking into account reactions with O atoms, hydrogen oxides, nitrogen oxides, and chlorine as well as vertical transport, temperature and tropospheric chemistry so that the total content and vertical distribution of O3 may be determined for a specified level of paleoatmospheric O2.

  16. LOW POWER UPCONVERSION FOR SOLAR FUELS PHOTOCHEMISTRY

    Energy Technology Data Exchange (ETDEWEB)

    Castellano, Felix N. [Bowling Green State University

    2013-08-05

    Earth abundant copper(I) diimine complexes represent a renewable and economically feasible alternative to commonly used heavy metal containing chromophores. In the metal-to-ligand charge transfer (MLCT) excited state, copper(I) diimine complexes typically undergo a significant structural rearrangement, leading to molecules with large Stokes shifts and very short excited state lifetimes, thereby limiting their usefulness as sensitizers in bimolecular electron and triplet energy transfer reactions. Strategically placed bulky substituents on the coordinating phenanthroline ligands have proven useful in restricting the transiently produced excited state Jahn-Teller distortion, leading to longer-lived excited states. By combining bulky sec-butyl groups in the 2- and 9- positions with methyl groups in the 3-,4-, 7-, and 8- positions, a remarkably long-lived (2.8 μs in DCM) copper(I) bis-phenanthroline complex, [Cu(dsbtmp)2]+, has been synthesized and characterized. Unlike other copper(I) diimine complexes, [Cu(dsbtmp)2]+ also retains a μs lifetime in coordinating solvents such as acetonitrile and water as a result of the cooperative sterics inherent in the molecular design. Preliminary results on the use of this complex in hydrogen-forming homogeneous photocatalysis is presented. Photon upconversion based on sensitized triplet-triplet annihilation (TTA) represents a photochemical means to generate high-energy photons (or high-energy chemical products) from low-energy excitation, having potential applications in solar energy conversion and solar fuels producing devices. For the first time, synthetically facile and earth abundant Cu(I) MLCT sensitizers have been successfully incorporated into two distinct photochemical upconversion schemes, affording both red-to-green and orange-to-blue wavelength conversions. Preliminary results on aqueous-based photochemical upconversion as well as intramolecular Sn(IV) porphyrins containing axially coordinated aromatic hydrocarbon

  17. Enhanced photochemistry on metal surfaces

    International Nuclear Information System (INIS)

    Goncher, G.M.; Parsons, C.A.; Harris, C.B.

    1984-01-01

    Due to the fast relaxation of molecular excited states in the vicinity of a metal or semiconductor surface, few observations of surface photochemistry have been reported. The following work concerns the surface-enhanced photo-reactions of a variety of physisorbed molecules on roughened Ag surfaces. In summary, photodecomposition leads to a graphitic surface carbon product which is monitored via surface-enhanced Raman scattering. In most cases an initial two-photon molecular absorption step followed by further absorption and fragmentation is thought to occur. Enhancement of the incident fields occurs through roughness-mediated surface plasmon resonances. This mechanism provides the amplified electromagnetic surface fields responsible for the observed photodecomposition. The photodecomposition experiments are performed under ultra-high vacuum. Surface characterization of the roughened surfaces was done by Scanning Electron Microscopy (SEM), and electron-stimulated emission. The SEM revealed morphology on the order of 300-400 A. This size of roughness feature, when modelled as isolated spheres should exhibit the well-known Mie resonances for light of the correct wavelengths. For protrusions existing on a surface these Mie resonances can be thought of as a coupling of the light with the surface plasmon. Experimental verification of these resonances was provided by the electron-stimulated light emission results. These showed that a polished Ag surface emitted only the expected transition radiation at the frequency of the Ag bulk plasmon. Upon roughening, however, a broad range of lower frequencies extending well into the visible are seen from electron irradiation of the surface. Large enhancements are expected for those frequencies which are able to couple into the surface modes

  18. Surface-Plasmon-Driven Hot Electron Photochemistry.

    Science.gov (United States)

    Zhang, Yuchao; He, Shuai; Guo, Wenxiao; Hu, Yue; Huang, Jiawei; Mulcahy, Justin R; Wei, Wei David

    2017-11-30

    Visible-light-driven photochemistry has continued to attract heightened interest due to its capacity to efficiently harvest solar energy and its potential to solve the global energy crisis. Plasmonic nanostructures boast broadly tunable optical properties coupled with catalytically active surfaces that offer a unique opportunity for solar photochemistry. Resonant optical excitation of surface plasmons produces energetic hot electrons that can be collected to facilitate chemical reactions. This review sums up recent theoretical and experimental approaches for understanding the underlying photophysical processes in hot electron generation and discusses various electron-transfer models on both plasmonic metal nanostructures and plasmonic metal/semiconductor heterostructures. Following that are highlights of recent examples of plasmon-driven hot electron photochemical reactions within the context of both cases. The review concludes with a discussion about the remaining challenges in the field and future opportunities for addressing the low reaction efficiencies in hot-electron-induced photochemistry.

  19. Synthesis, characterization and photochemistry of a new ...

    Indian Academy of Sciences (India)

    The synthesis, crystal structure, redox characteristics and photochemistry of a new heptamolyb- ... The ability of [Mo7O24]−6 to function as a pure “inor- .... Abbreviations used: bpp = 1,3-bis(4-pyridyl)propane; 2-amp = 2-aminopyridine; DMSO ...

  20. Fifteenth DOE solar photochemistry research conference

    Energy Technology Data Exchange (ETDEWEB)

    1991-01-01

    This is a compilation of abstracts from the Fifteenth DOE Solar Photochemistry Research Conference hosted by the Solar Energy Research Institute which took place June 2--6, 1991. A large variety of topics pertinent to solar energy conversion are covered, including photoinduced electron transfer, photochemical energy conversion, and photosynthetic energy conversion. (GHH)

  1. Vertical sounding balloons for stratospheric photochemistry

    Science.gov (United States)

    Pommereau, J. P.

    The use of vertical sounding balloons for stratospheric photochemistry studies is illustrated by the use of a vertical piloted gas balloon for the search of NO2 diurnal variations. It is shown that the use of montgolfieres (hot air balloons) can enhance the vertical sounding technique. Particular attention is given to a sun-heated montgolfiere and to the more sophisticated infrared montgolfiere that is able to perform three to four vertical excursions per day and to remain aloft for weeks or months.

  2. Solid state photochemistry. Subpanel A-2(c): Challenges and opportunities in photochemistry

    Energy Technology Data Exchange (ETDEWEB)

    Czanderna, A.W. [National Renewable Energy Laboratory, Golden, CO (United States)

    1996-09-01

    In contrast with the prior two subsections, the topics in solid state photochemistry range from photo(thermal)-induced degradation to synthesizing new compounds with desirable functions or properties. We will therefore discuss the importance of each relative to existing technological barriers, recent progress, potential applications, and the advantages expected from new information from basic science, especially, as it relates to the DOE mission.

  3. The Electrodeless Discharge Lamp: A Prospective Tool for Photochemistry Part 3. The Microwave Photochemistry Reactor

    Czech Academy of Sciences Publication Activity Database

    Klán, P.; Hájek, Milan; Církva, Vladimír

    2001-01-01

    Roč. 140, č. 3 (2001), s. 185-189 ISSN 1010-6030 Institutional research plan: CEZ:AV0Z4072921 Keywords : photochemistry * electrodeless discharge lamp * microwave Subject RIV: CH - Nuclear ; Quantum Chemistry Impact factor: 1.038, year: 2001

  4. A personal perspective on the future of flow photochemistry

    NARCIS (Netherlands)

    Noël, Timothy

    2017-01-01

    Photochemistry and photoredox catalysis have witnessed a remarkable comeback in the last decade. Flow chemistry has been of pivotal importance to alleviate some of the classical obstacles associated with photochemistry. Herein, we analyze some of the most exciting features provided by photo flow

  5. Proceedings of the Nineteenth DOE Solar Photochemistry Research Conference

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-07-01

    This document is a compilation of reports presented at the Nineteenth DOE Solar Photochemistry Research Conference. Sessions included photophysical properties of transition metal complexes, cage effects on photochemistry, charge transfer, photo-induced charge separation in biomimetic molecules, photosynthesis, and electron transfer.

  6. Tunable lasers for waste management photochemistry applications

    International Nuclear Information System (INIS)

    Finch, F.T.

    1978-09-01

    A review of lasers with potential photochemical applications in waste management indicates that dye lasers, as a class, can provide tunable laser output through the visible and near-uv regions of the spectrum of most interest to photochemistry. Many variables can affect the performance of a specific dye laser, and the interactions of these variables, at the current state of the art, are complex. The recent literature on dye-laser characteristics has been reviewed and summarized, with emphasis on those parameters that most likely will affect the scaling of dye lasers in photochemical applications. Current costs are reviewed and correlated with output power. A new class of efficient uv lasers that appear to be scalable in both energy output and pulse rate, based on rare-gas halide excimers and similar molecules, is certain to find major applications in photochemistry. Because the most important developments are too recent to be adequately described in the literature or are the likely outcome of current experiments, the basic physics underlying the class of excimer lasers is described. Specific cost data are unavailable, but these new gas lasers should reflect costs similar to those of existing gas lasers, in particular, the pulsed CO 2 lasers. To complete the survey of tunable-laser characteristics, the technical characteristics of the various classes of lasers in the ir are summarized. Important developments in ir laser technology are being accelerated by isotope-separation research, but, initially at least, this portion of the spectrum is least likely to receive emphasis in waste-management-oriented photochemistry

  7. Photochemistry and photophysics concepts, research, applications

    CERN Document Server

    Balzani , Vincenzo; Juris, Alberto

    2014-01-01

    This textbook covers the spectrum from basic concepts of photochemistry and photophysics to selected examples of current applications and research.Clearly structured, the first part of the text discusses the formation, properties and reactivity of excited states of inorganic and organic molecules and supramolecular species, as well as experimental techniques. The second part focuses on the photochemical and photophysical processes in nature and artificial systems, using a wealth of examples taken from applications in nature, industry and current research fields, ranging from natural photosynth

  8. Photochemistry of materials in the stratosphere

    Energy Technology Data Exchange (ETDEWEB)

    Johnston, H.S. [Lawrence Berkeley Laboratories, CA (United States)

    1993-12-01

    This research is concerned with global change in the atmosphere, including photochemical modeling and, in the past, experimental gas-phase photochemistry involving molecular dynamics and laboratory study of atmospheric chemical reactions. The experimental work on this project concluded in August 1991, but there is a back-log of several journal articles to be written and submitted for publication. The theoretical work involves photochemical modeling in collaboration with Lawrence Livermore National Laboratory (LLNL) and advising the Upper Atmosphere Research Program on Atmospheric Effects of Stratospheric Aircraft, National Aeronautics and Space Administration (NASA).

  9. Microwave Photochemistry. Applications in Organic Synthesis

    Czech Academy of Sciences Publication Activity Database

    Církva, Vladimír; Relich, Stanislav

    2011-01-01

    Roč. 8, č. 3 (2011), s. 282-293 ISSN 1570-193X Institutional research plan: CEZ:AV0Z40720504 Keywords : microwave * photochemistry * electrodeless discharge lamp Subject RIV: CH - Nuclear ; Quantum Chemistry Impact factor: 2.406, year: 2011 http://www.scopus.com/record/display.url?eid=2-s2.0-79960013317&origin=resultslist&sort=plf-f&src=s&st1=cirkva%2cv&sid=95rFucNho6qr5iGwVeMnh_W%3a150&sot=b&sdt=b&sl=21&s=AUTHOR-NAME%28cirkva%2cv%29&relpos=0&relpos=0&searchTerm=AUTHOR-NAME(cirkva,v)

  10. Proceedings of the Fourteenth DOE solar photochemistry research conference

    Energy Technology Data Exchange (ETDEWEB)

    1989-01-01

    The central themes of this year's Solar Photochemistry Research Conference encompassed initial charge separation in photosynthesis, photoinduced charge separation in other organized assemblies, electron transfer, organic and inorganic photochemistry, and photoelectrochemistry. This volume contains a copy of the program the abstracts of 29 formal presentations and 47 posters, a record of the discussion following each presentation, and an address list for the 96 attendees. Individual projects are processed separately for the databases. .

  11. Proceedings of the Fourteenth DOE solar photochemistry research conference

    International Nuclear Information System (INIS)

    1989-01-01

    The central themes of this year's Solar Photochemistry Research Conference encompassed initial charge separation in photosynthesis, photoinduced charge separation in other organized assemblies, electron transfer, organic and inorganic photochemistry, and photoelectrochemistry. This volume contains a copy of the program the abstracts of 29 formal presentations and 47 posters, a record of the discussion following each presentation, and an address list for the 96 attendees. Individual projects are processed separately for the databases

  12. Molecular beam studies of stratospheric photochemistry

    Science.gov (United States)

    Moore, Teresa Anne

    1998-12-01

    Photochemistry of chlorine oxide containing species plays a major role in stratospheric ozone depletion. This thesis discusses two photodissociation studies of the key molecules ClONO2 and ClOOCl which were previously thought to only produce Cl-atom (ozone depleting) products at wavelengths relevant to the stratosphere. The development of a molecular beam source of ClOOCl and the photodissociation dynamics of the model system Cl2O are also discussed. In the first chapter, the photochemistry of ClONO2 is examined at 308 nm using the technique of photofragment translational spectroscopy. Two primary decomposition pathways, leading to Cl + NO3 and ClO + NO2, were observed, with a lower limit of 0.33 for the relative yield of ClO. The angular distributions for both channels were anisotropic, indicating that the dissociation occurs within a rotational period. Chapter two revisits the photodissociation dynamics of Cl2O at 248 and 308 nm, on which we had previously reported preliminary findings. At 248 nm, three distinct dissociation pathways leading to Cl + ClO products were resolved. At 308 nm, the angular distribution was slightly more isotropic that previously reported, leaving open the possibility that Cl2O excited at 308 nm lives longer than a rotational period. Chapter three describes the development and optimization of a molecular beam source of ClOOCl. We utilized pulsed laser photolysis of ClA2O to generate ClO radicals, and cooled the cell to promote three body recombination to form ClOOCl. The principal components in the beam were Cl2, Cl2O, and ClOOCl. In the fourth chapter, the photodissociation dynamics of ClOOCl are investigated at 248 and 308 nm. We observed multiple dissociation pathways which produced ClO + ClO and 2Cl + O2 products. The relative Cl:ClO product yields are 1.0:0.13 and 1.0:0.20 for ClOOCl photolysis at 248 and 308 nm, respectively. The upper limit for the relative yield of the ClO + ClO channel was 0.19 at 248 nm and 0.31 at 308 nm

  13. Mousse photochemistry formation; Formacao fotoquimica de mousse

    Energy Technology Data Exchange (ETDEWEB)

    Rangel, George W.M.; Nicodem, David E. [Universidade Federal, Rio de Janeiro, RJ (Brazil). Inst. de Quimica]. E-mail: gwallace_iq@yahoo.com.br; nicodem@iq.ufrj.br

    2003-07-01

    The petroleum, when spilled in the sea it forms an emulsion of water in oil could contain up to 90% of water. This emulsion, called Mousse of Chocolate, it can be very stable, taking to the increase of the environmental impact and impeding the microbiological degradation. It was observed that the petroleum, when irradiated with solar light, it forms Mousse more easily. However, same being known about the importance of the action of the light in the formation of Mousse, little it is known regarding the processes and conditions involved in the formation of Mousse. This project proposes the study of the process of formation of Mousse, in function of the suffered transformations for petroleum after solar irradiation. We will study the relationship between the stability and formation of Mousse and the present amount of asphaltenes in the petroleum as a result of the irradiation. We will develop a methodology for analysis of emulsions of water in petroleum, in way we know her/it the stability of the emulsion in function of the time and the amount of water in the same. We will study the behavior of a sample of Brazilian petroleum of Campos' Basin, already used in other photochemistry studies. We will analyze the effect of the time of irradiation in the asphaltenes formation and Mousse. We will also analyze other types of petroleum, for us to compare results with obtained them in the Brazilian petroleum. (author)

  14. Radiation Chemistry and Photochemistry of Ionic Liquids

    International Nuclear Information System (INIS)

    Wishart, J.F.; Takahaski, K.

    2010-01-01

    As our understanding of ionic liquids and their tunable properties has grown, it is possible to see many opportunities for ionic liquids to contribute to the sustainable use of energy. The potential safety and environmental benefits of ionic liquids, as compared to conventional solvents, have attracted interest in their use as processing media for the nuclear fuel cycle. Therefore, an understanding of the interactions of ionizing radiation and photons with ionic liquids is strongly needed. However, the radiation chemistry of ionic liquids is still a relatively unexplored topic although there has been a significant increase in the number of researchers in the field recently. This article provides a brief introduction to ionic liquids and their interesting properties, and recent advances in the radiation chemistry and photochemistry of ionic liquids. In this article, we will mainly focus on excess electron dynamics and radical reaction dynamics. Because solvation dynamics processes in ionic liquids are much slower than in molecular solvents, one of the distinguishing characteristics is that pre-solvated electrons play an important role in ionic liquid radiolysis. It will be also shown that the reaction dynamics of radical ions is significantly different from that observed in molecular solvents because of the Coulombic screening effects and electrostatic interactions in ionic liquids.

  15. Active molecular iodine photochemistry in the Arctic.

    Science.gov (United States)

    Raso, Angela R W; Custard, Kyle D; May, Nathaniel W; Tanner, David; Newburn, Matt K; Walker, Lawrence; Moore, Ronald J; Huey, L G; Alexander, Liz; Shepson, Paul B; Pratt, Kerri A

    2017-09-19

    During springtime, the Arctic atmospheric boundary layer undergoes frequent rapid depletions in ozone and gaseous elemental mercury due to reactions with halogen atoms, influencing atmospheric composition and pollutant fate. Although bromine chemistry has been shown to initiate ozone depletion events, and it has long been hypothesized that iodine chemistry may contribute, no previous measurements of molecular iodine (I 2 ) have been reported in the Arctic. Iodine chemistry also contributes to atmospheric new particle formation and therefore cloud properties and radiative forcing. Here we present Arctic atmospheric I 2 and snowpack iodide (I - ) measurements, which were conducted near Utqiaġvik, AK, in February 2014. Using chemical ionization mass spectrometry, I 2 was observed in the atmosphere at mole ratios of 0.3-1.0 ppt, and in the snowpack interstitial air at mole ratios up to 22 ppt under natural sunlit conditions and up to 35 ppt when the snowpack surface was artificially irradiated, suggesting a photochemical production mechanism. Further, snow meltwater I - measurements showed enrichments of up to ∼1,900 times above the seawater ratio of I - /Na + , consistent with iodine activation and recycling. Modeling shows that observed I 2 levels are able to significantly increase ozone depletion rates, while also producing iodine monoxide (IO) at levels recently observed in the Arctic. These results emphasize the significance of iodine chemistry and the role of snowpack photochemistry in Arctic atmospheric composition, and imply that I 2 is likely a dominant source of iodine atoms in the Arctic.

  16. Isoprene photochemistry over the Amazon rainforest

    Science.gov (United States)

    Liu, Yingjun; Brito, Joel; Dorris, Matthew R.; Rivera-Rios, Jean C.; Seco, Roger; Bates, Kelvin H.; Artaxo, Paulo; Duvoisin, Sergio; Keutsch, Frank N.; Kim, Saewung; Goldstein, Allen H.; Guenther, Alex B.; Manzi, Antonio O.; Souza, Rodrigo A. F.; Springston, Stephen R.; Watson, Thomas B.; McKinney, Karena A.

    2016-01-01

    Isoprene photooxidation is a major driver of atmospheric chemistry over forested regions. Isoprene reacts with hydroxyl radicals (OH) and molecular oxygen to produce isoprene peroxy radicals (ISOPOO). These radicals can react with hydroperoxyl radicals (HO2) to dominantly produce hydroxyhydroperoxides (ISOPOOH). They can also react with nitric oxide (NO) to largely produce methyl vinyl ketone (MVK) and methacrolein (MACR). Unimolecular isomerization and bimolecular reactions with organic peroxy radicals are also possible. There is uncertainty about the relative importance of each of these pathways in the atmosphere and possible changes because of anthropogenic pollution. Herein, measurements of ISOPOOH and MVK + MACR concentrations are reported over the central region of the Amazon basin during the wet season. The research site, downwind of an urban region, intercepted both background and polluted air masses during the GoAmazon2014/5 Experiment. Under background conditions, the confidence interval for the ratio of the ISOPOOH concentration to that of MVK + MACR spanned 0.4–0.6. This result implies a ratio of the reaction rate of ISOPOO with HO2 to that with NO of approximately unity. A value of unity is significantly smaller than simulated at present by global chemical transport models for this important, nominally low-NO, forested region of Earth. Under polluted conditions, when the concentrations of reactive nitrogen compounds were high (>1 ppb), ISOPOOH concentrations dropped below the instrumental detection limit (<60 ppt). This abrupt shift in isoprene photooxidation, sparked by human activities, speaks to ongoing and possible future changes in the photochemistry active over the Amazon rainforest. PMID:27185928

  17. Active molecular iodine photochemistry in the Arctic

    Energy Technology Data Exchange (ETDEWEB)

    Raso, Angela R.; Custard, Kyle D.; May, Nathaniel W.; Tanner, David; Newburn, Matthew K.; Walker, Lawrence R.; Moore, Ronald J.; Huey, L. G.; Alexander, Lizabeth; Shepson, Paul B.; Pratt, Kerri A.

    2017-09-05

    During springtime, the Arctic atmospheric boundary layer undergoes frequent rapid depletions in ozone and gaseous elemental mercury due to reactions with halogen atoms, influencing atmospheric composition and pollutant fate. Although bromine chemistry has been shown to initiate ozone depletion events, and it has long been hypothesized that iodine chemistry may contribute, no previous measurements of molecular iodine (I2) have been reported in the Arctic. Iodine chemistry also contributes to atmospheric new particle formation and therefore cloud properties and radiative forcing. Here we present Arctic atmospheric I2 and snowpack iodide (I-) measurements, which were conducted near Utqiagvik, AK, in February 2014. Using chemical ionization mass spectrometry, I2 was observed in the atmosphere at mole ratios of 0.3–1.0 ppt, and in the snowpack interstitial air at mole ratios up to 22 ppt under natural sunlit conditions and up to 35 ppt when the snowpack surface was artificially irradiated, suggesting a photochemical production mechanism. Further, snow meltwater I-measurements showed enrichments of up to ~1,900 times above the seawater ratio of I-/Na+, consistent with iodine activation and recycling. Modeling shows that observed I2 levels are able to significantly increase ozone depletion rates, while also producing iodine monoxide (IO) at levels recently observed in the Arctic. These results emphasize the significance of iodine chemistry and the role of snowpack photochemistry in Arctic atmospheric composition, and imply that I2 is likely a dominant source of iodine atoms in the Arctic.

  18. Photochemistry of modified proteins benzophenone-containing bovine serum albumin

    International Nuclear Information System (INIS)

    Mariano, P.S.; Glover, G.I.; Wilkinson, T.J.

    1976-01-01

    The results of exploratory and mechanistic studies of the photochemistry of poly-p-benzoyl-acetimido-bovine serum albumin, a modified protein containing photoreactive and photosensitizing groups, are reported. Specifically described are recent findings concerning (1) the synthesis and characterization of a modified bovine serum albumin that contains benzophenone-like moieties, (2) the photochemistry of this modified protein which appeared to involve photoreductive coupling of the benzophenone chromophores to the protein backbone, and (3) triplet energy transfer from modified bovine serum albumin to small molecule acceptors resulting in quenching of the photoreaction. (author)

  19. Promotion of multi-electron transfer for enhanced photocatalysis: A review focused on oxygen reduction reaction

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Changhua [Centre for Advanced Optoelectronic Functional Materials Research, and Key Laboratory for UV-Emitting Materials and Technology of Ministry of Education, Northeast Normal University, Changchun 130024 (China); College of Chemistry and Biology, Beihua University, Jilin 132013 (China); Zhang, Xintong, E-mail: xtzhang@nenu.edu.cn [Centre for Advanced Optoelectronic Functional Materials Research, and Key Laboratory for UV-Emitting Materials and Technology of Ministry of Education, Northeast Normal University, Changchun 130024 (China); Liu, Yichun [Centre for Advanced Optoelectronic Functional Materials Research, and Key Laboratory for UV-Emitting Materials and Technology of Ministry of Education, Northeast Normal University, Changchun 130024 (China)

    2015-12-15

    Highlights: • Oxygen reduction reaction (ORR) in photocatalysis process is focused. • Multi-electron transfer ORR is reviewed. • This review provides a guide to access to enhanced photocatalysis via multi-electron transfer. - Abstract: Semiconductor photocatalysis has attracted significant interest for solar light induced environmental remediation and solar fuel generation. As is well known, photocatalytic performance is determined by three steps: photoexcitation, separation and transport of photogenerated charge carriers, and surface reactions. To achieve higher efficiency, significant efforts have been made on improvement of efficiency of above first two steps, which have been well documented in recent review articles. In contrast, this review intends to focus on strategies moving onto the third step of improvement for enhanced photocatalysis wherein active oxygen species including superoxide radical, hydrogen peroxide, hydroxyl radical are in situ detected. Particularly, surface electron-transfer reduction of oxygen over single component photocatalysts is reviewed and systems enabling multi-electron transfer induced oxygen reduction reaction (ORR) are highlighted. It is expected this review could provide a guideline for readers to better understand the critical role of ORR over photocatalyst in charge carrier separation and transfer and obtain reliable results for enhanced aerobic photocatalysis.

  20. PHOTOCHEMISTRY IN TERRESTRIAL EXOPLANET ATMOSPHERES. I. PHOTOCHEMISTRY MODEL AND BENCHMARK CASES

    Energy Technology Data Exchange (ETDEWEB)

    Hu Renyu; Seager, Sara; Bains, William, E-mail: hury@mit.edu [Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States)

    2012-12-20

    We present a comprehensive photochemistry model for exploration of the chemical composition of terrestrial exoplanet atmospheres. The photochemistry model is designed from the ground up to have the capacity to treat all types of terrestrial planet atmospheres, ranging from oxidizing through reducing, which makes the code suitable for applications for the wide range of anticipated terrestrial exoplanet compositions. The one-dimensional chemical transport model treats up to 800 chemical reactions, photochemical processes, dry and wet deposition, surface emission, and thermal escape of O, H, C, N, and S bearing species, as well as formation and deposition of elemental sulfur and sulfuric acid aerosols. We validate the model by computing the atmospheric composition of current Earth and Mars and find agreement with observations of major trace gases in Earth's and Mars' atmospheres. We simulate several plausible atmospheric scenarios of terrestrial exoplanets and choose three benchmark cases for atmospheres from reducing to oxidizing. The most interesting finding is that atomic hydrogen is always a more abundant reactive radical than the hydroxyl radical in anoxic atmospheres. Whether atomic hydrogen is the most important removal path for a molecule of interest also depends on the relevant reaction rates. We also find that volcanic carbon compounds (i.e., CH{sub 4} and CO{sub 2}) are chemically long-lived and tend to be well mixed in both reducing and oxidizing atmospheres, and their dry deposition velocities to the surface control the atmospheric oxidation states. Furthermore, we revisit whether photochemically produced oxygen can cause false positives for detecting oxygenic photosynthesis, and find that in 1 bar CO{sub 2}-rich atmospheres oxygen and ozone may build up to levels that have conventionally been accepted as signatures of life, if there is no surface emission of reducing gases. The atmospheric scenarios presented in this paper can serve as the

  1. A multi-band, multi-level, multi-electron model for efficient FDTD simulations of electromagnetic interactions with semiconductor quantum wells

    Science.gov (United States)

    Ravi, Koustuban; Wang, Qian; Ho, Seng-Tiong

    2015-08-01

    We report a new computational model for simulations of electromagnetic interactions with semiconductor quantum well(s) (SQW) in complex electromagnetic geometries using the finite-difference time-domain method. The presented model is based on an approach of spanning a large number of electron transverse momentum states in each SQW sub-band (multi-band) with a small number of discrete multi-electron states (multi-level, multi-electron). This enables accurate and efficient two-dimensional (2-D) and three-dimensional (3-D) simulations of nanophotonic devices with SQW active media. The model includes the following features: (1) Optically induced interband transitions between various SQW conduction and heavy-hole or light-hole sub-bands are considered. (2) Novel intra sub-band and inter sub-band transition terms are derived to thermalize the electron and hole occupational distributions to the correct Fermi-Dirac distributions. (3) The terms in (2) result in an explicit update scheme which circumvents numerically cumbersome iterative procedures. This significantly augments computational efficiency. (4) Explicit update terms to account for carrier leakage to unconfined states are derived, which thermalize the bulk and SQW populations to a common quasi-equilibrium Fermi-Dirac distribution. (5) Auger recombination and intervalence band absorption are included. The model is validated by comparisons to analytic band-filling calculations, simulations of SQW optical gain spectra, and photonic crystal lasers.

  2. Radiation and Photochemistry Section annual report, October 1990--September 1991

    International Nuclear Information System (INIS)

    1991-12-01

    This report describes the radiation chemistry and photochemistry of reactive intermediates in the condensed phase. The section on the chemistry of ions treats condensed-phase reactions of radical cations, radical cations in zeolite matrices, high energy chemistry, ions and excited states in radiolysis, and photochemistry of the polymer imaging systems. The section on the role of solvent in chemical reactivity describes a study of atomic hydrogen and deuterium in water radiolysis, solvated electron thermodynamics and transport properties, solvent relaxation dynamics, and solvation of an excess electron in an aqueous solution of LiCl. A separate section outlines activities at the 20-MeV linac and the 3-MeV Van de Graaff accelerator

  3. The nature of light. A brief introduction to photochemistry

    OpenAIRE

    Font, Josep

    2017-01-01

    The first lecture of the seminar on Light, Darkness and Living Beings, held in Mataró in March 2015, was devoted to explaining the dual nature of light and the interaction of this electromagnetic radiation with matter, considering mainly the photochemical aspects. This article summarizes the lecture, offering a brief description of the basis of photochemistry and giving some examples of reactions that need light in order to occur. Examples related to biological systems (e.g. plant photosynthe...

  4. Photochemistry in Saturn’s Ring-Shadowed Atmosphere: Photochemistry and Haze Observations

    Science.gov (United States)

    Edgington, Scott G.; Atreya, Sushil K.; Baines, Kevin H.; West, Robert A.; Bjoraker, Gordon L.; Fletcher, Leigh; Momary, Thomas W.; Wilson, Eric; CIRS, ISS, UVIS, VIMS

    2017-10-01

    After 13 years of observing Saturn, Cassini would have ended nearly a half Saturnian year. During this epoch, the ring shadow has moved from covering much of the northern hemisphere to covering a large swath southern hemisphere. The net effect is that the intensity of both ultraviolet and visible sunlight penetrating through the rings to any particular latitude will vary depending on both Saturn’s axis relative to the Sun and the optical thickness of each ring system. In essence, the rings act like semi-transparent venetian blinds. This effect magnifies the effect due to axial tilt alone and acts to turn off photochemistry and haze generation. This effect is seen in both the presence of a bluish Rayleigh-scattering atmosphere in 2004 in the northern hemisphere and color change to blue in the northern hemisphere.Previous work examined the variation of the solar flux as a function of solar inclination, i.e. for each 7.25-year season at Saturn. We report on the impact of the oscillating ring shadow, in addition to variation due to axial tilt, on photolysis and production rates of hydrocarbons and phosphine in Saturn’s stratosphere and upper troposphere. The impact of these production and loss rates on the abundance of long-lived photochemical products leading to haze formation are explored. We assess their impact on a disequilibrium species whose presence in the upper troposphere can be used as a tracer of convective processes in the deeper atmosphere.We will also present our ongoing analysis of Cassini’s CIRS, UVIS, and VIMS datasets that provide an estimate of the evolving haze content. In particular, we will examine how the region inside Saturn’s famous hexagonal jet stream changes over time from a relatively clear atmosphere to a hazy one. We also explore how the hexagon acts like a barrier to transport, isolating Saturn’s north polar region from outside influences of photochemically-generated molecules and haze.The research described in this paper was

  5. Path integral molecular dynamics for exact quantum statistics of multi-electronic-state systems.

    Science.gov (United States)

    Liu, Xinzijian; Liu, Jian

    2018-03-14

    An exact approach to compute physical properties for general multi-electronic-state (MES) systems in thermal equilibrium is presented. The approach is extended from our recent progress on path integral molecular dynamics (PIMD), Liu et al. [J. Chem. Phys. 145, 024103 (2016)] and Zhang et al. [J. Chem. Phys. 147, 034109 (2017)], for quantum statistical mechanics when a single potential energy surface is involved. We first define an effective potential function that is numerically favorable for MES-PIMD and then derive corresponding estimators in MES-PIMD for evaluating various physical properties. Its application to several representative one-dimensional and multi-dimensional models demonstrates that MES-PIMD in principle offers a practical tool in either of the diabatic and adiabatic representations for studying exact quantum statistics of complex/large MES systems when the Born-Oppenheimer approximation, Condon approximation, and harmonic bath approximation are broken.

  6. Multi-Electron Production at High Transverse Momenta in ep Collisions at HERA

    CERN Document Server

    Aktas, A.; Anthonis, T.; Asmone, A.; Babaev, A.; Backovic, S.; Bahr, J.; Baranov, P.; Barrelet, E.; Bartel, W.; Baumgartner, S.; Becker, J.; Beckingham, M.; Behnke, O.; Behrendt, O.; Belousov, A.; Berger, C.; Berndt, T.; Bizot, J.C.; Bohme, J.; Boenig, M.O.; Boudry, V.; Bracinik, J.; Braunschweig, W.; Brisson, V.; Broker, H.B.; Brown, D.P.; Bruncko, D.; Busser, F.W.; Bunyatyan, A.; Buschhorn, G.; Bystritskaya, L.; Campbell, A.J.; Caron, S.; Cassol-Brunner, F.; Chekelian, V.; Clarke, D.; Collard, C.; Contreras, J.G.; Coppens, Y.R.; Coughlan, J.A.; Cousinou, M.C.; Cox, B.E.; Cozzika, G.; Cvach, J.; Dainton, J.B.; Dau, W.D.; Daum, K.; Delcourt, B.; Delerue, N.; Demirchyan, R.; De Roeck, A.; De Wolf, E.A.; Diaconu, C.; Dingfelder, J.; Dodonov, V.; Dowell, J.D.; Dubak, A.; Duprel, C.; Eckerlin, Guenter; Efremenko, V.; Egli, S.; Eichler, R.; Eisele, F.; Ellerbrock, M.; Elsen, E.; Erdmann, M.; Erdmann, W.; Faulkner, P.J.W.; Favart, L.; Fedotov, A.; Felst, R.; Ferencei, J.; Fleischer, M.; Fleischmann, P.; Fleming, Y.H.; Flucke, G.; Flugge, G.; Fomenko, A.; Foresti, I.; Formanek, J.; Franke, G.; Frising, G.; Gabathuler, E.; Gabathuler, K.; Garvey, J.; Gassner, J.; Gayler, Joerg; Gerhards, R.; Gerlich, C.; Ghazaryan, Samvel; Goerlich, L.; Gogitidze, N.; Gorbounov, S.; Grab, C.; Grabski, V.; Grassler, H.; Greenshaw, T.; Gregori, M.; Grindhammer, Guenter; Haidt, D.; Hajduk, L.; Haller, J.; Heinzelmann, G.; Henderson, R.C.W.; Henschel, H.; Henshaw, O.; Heremans, R.; Herrera, G.; Herynek, I.; Hildebrandt, M.; Hiller, K.H.; Hladky, J.; Hoting, P.; Hoffmann, D.; Horisberger, R.; Hovhannisyan, A.; Ibbotson, M.; Jacquet, M.; Janauschek, L.; Janssen, X.; Jemanov, V.; Jonsson, L.; Johnson, C.; Johnson, D.P.; Jung, H.; Kant, D.; Kapichine, M.; Karlsson, M.; Katzy, J.; Keil, F.; Keller, N.; Kennedy, J.; Kenyon, I.R.; Kiesling, Christian M.; Klein, M.; Kleinwort, C.; Kluge, T.; Knies, G.; Koblitz, B.; Kolya, S.D.; Korbel, V.; Kostka, P.; Koutouev, R.; Kropivnitskaya, A.; Kroseberg, J.; Kueckens, J.; Kuhr, T.; Landon, M.P.J.; Lange, W.; Lastovicka, T.; Laycock, P.; Lebedev, A.; Leissner, B.; Lemrani, R.; Lendermann, V.; Levonian, S.; List, B.; Lobodzinska, E.; Loktionova, N.; Lopez-Fernandez, R.; Lubimov, V.; Lueders, H.; Luders, S.; Luke, D.; Lytkin, L.; Makankine, A.; Malden, N.; Malinovski, E.; Mangano, S.; Marage, P.; Marks, J.; Marshall, R.; Martyn, H.U.; Martyniak, J.; Maxfield, S.J.; Meer, D.; Mehta, A.; Meier, K.; Meyer, A.B.; Meyer, H.; Meyer, J.; Michine, S.; Mikocki, S.; Milstead, D.; Moreau, F.; Morozov, A.; Morris, J.V.; Muller, K.; Murin, P.; Nagovizin, V.; Naroska, B.; Naumann, J.; Naumann, T.; Newman, Paul R.; Niebergall, F.; Niebuhr, C.; Nikitin, D.; Nowak, G.; Nozicka, M.; Olivier, B.; Olsson, J.E.; Ozerov, D.; Pascaud, C.; Patel, G.D.; Peez, M.; Perez, E.; Petrukhin, A.; Pitzl, D.; Poschl, R.; Povh, B.; Raicevic, N.; Rauschenberger, J.; Reimer, P.; Reisert, B.; Risler, C.; Rizvi, E.; Robmann, P.; Roosen, R.; Rostovtsev, A.; Rusakov, S.; Rybicki, K.; Sankey, D.P.C.; Sauvan, E.; Schatzel, S.; Scheins, J.; Schilling, F.P.; Schleper, P.; Schmidt, D.; Schmidt, S.; Schmitt, S.; Schneider, M.; Schoeffel, L.; Schoning, A.; Schroder, V.; Schultz-Coulon, H.C.; Schwanenberger, C.; Sedlak, K.; Sefkow, F.; Sheviakov, I.; Shtarkov, L.N.; Sirois, Y.; Sloan, T.; Smirnov, P.; Soloviev, Y.; South, D.; Spaskov, V.; Specka, Arnd E.; Spitzer, H.; Stamen, R.; Stella, B.; Stiewe, J.; Strauch, I.; Straumann, U.; Thompson, Graham; Thompson, P.D.; Tomasz, F.; Traynor, D.; Truoel, Peter; Tsipolitis, G.; Tsurin, I.; Turnau, J.; Turney, J.E.; Tzamariudaki, E.; Uraev, A.; Urban, Marcel; Usik, A.; Valkar, S.; Valkarova, A.; Vallee, C.; Van Mechelen, P.; Vargas Trevino, A.; Vassiliev, S.; Vazdik, Y.; Veelken, C.; Vest, A.; Vichnevski, A.; Volchinski, V.; Wacker, K.; Wagner, J.; Waugh, B.; Weber, G.; Weber, R.; Wegener, D.; Werner, C.; Werner, N.; Wessels, M.; Wessling, B.; Winde, M.; Winter, G.G.; Wissing, C.; Woehrling, E.E.; Wunsch, E.; Zacek, J.; Zalesak, J.; Zhang, Z.; Zhokin, A.; Zomer, F.; zur Nedden, M.

    2003-01-01

    Multi-electron production is studied at high electron transverse momentum in positron- and electron-proton collisions using the H1 detector at HERA. The data correspond to an integrated luminosity of 115 pb-1. Di-electron and tri-electron event yields are measured. Cross sections are derived in a restricted phase space region dominated by photon-photon collisions. In general good agreement is found with the Standard Model predictions. However, for electron pair invariant masses above 100 GeV, three di-electron events and three tri-electron events are observed, compared to Standard Model expectations of 0.30 pm 0.04 and 0.23 pm 0.04, respectively.

  7. Photochemistry of psoralen-DNA adducts, biological effects of psoralen-DNA adducts, applications of psoralen-DNA photochemistry

    Energy Technology Data Exchange (ETDEWEB)

    Shi, Yun-bo

    1988-03-01

    This thesis consists of three main parts and totally eight chapters. In Part I, The author will present studies on the photochemistry of psoralen-DNA adducts, specifically, the wavelength dependencies for the photoreversals of thymidine-HMT (4'-hydroxymethyl-4, 5', 8-trimenthylpsoralen) monoadducts and diadduct and the same adducts incorporated in DNA helices and the wavelength dependecies for the photocrossslinking of thymidine-HMT monoadducts in double-stranded helices. In Part II, The author will report some biological effects of psoralen-DNA adducts, i.e., the effects on double-stranded DNA stability, DNA structure, and transcription by E. coli and T7 RNA polymerases. Finally, The author will focus on the applications of psoralen-DNA photochemistry to investigation of protein-DNA interaction during transcription, which includes the interaction of E. coli and T7 RNA polymerases with DNA in elongation complexes arrested at specific psoralen-DNA adduct sites as revealed by DNase I footprinting experiments. 123 refs., 52 figs., 12 tabs.

  8. Photochemistry of psoralen-DNA adducts, biological effects of psoralen-DNA adducts, applications of psoralen-DNA photochemistry

    International Nuclear Information System (INIS)

    Shi, Yun-bo.

    1988-03-01

    This thesis consists of three main parts and totally eight chapters. In Part I, The author will present studies on the photochemistry of psoralen-DNA adducts, specifically, the wavelength dependencies for the photoreversals of thymidine-HMT (4'-hydroxymethyl-4, 5', 8-trimenthylpsoralen) monoadducts and diadduct and the same adducts incorporated in DNA helices and the wavelength dependecies for the photocrossslinking of thymidine-HMT monoadducts in double-stranded helices. In Part II, The author will report some biological effects of psoralen-DNA adducts, i.e., the effects on double-stranded DNA stability, DNA structure, and transcription by E. coli and T7 RNA polymerases. Finally, The author will focus on the applications of psoralen-DNA photochemistry to investigation of protein-DNA interaction during transcription, which includes the interaction of E. coli and T7 RNA polymerases with DNA in elongation complexes arrested at specific psoralen-DNA adduct sites as revealed by DNase I footprinting experiments. 123 refs., 52 figs., 12 tabs

  9. Room Temperature, Hybrid Sodium-Based Flow Batteries with Multi-Electron Transfer Redox Reactions

    Science.gov (United States)

    Shamie, Jack S.; Liu, Caihong; Shaw, Leon L.; Sprenkle, Vincent L.

    2015-01-01

    We introduce a new concept of hybrid Na-based flow batteries (HNFBs) with a molten Na alloy anode in conjunction with a flowing catholyte separated by a solid Na-ion exchange membrane for grid-scale energy storage. Such HNFBs can operate at ambient temperature, allow catholytes to have multiple electron transfer redox reactions per active ion, offer wide selection of catholyte chemistries with multiple active ions to couple with the highly negative Na alloy anode, and enable the use of both aqueous and non-aqueous catholytes. Further, the molten Na alloy anode permits the decoupled design of power and energy since a large volume of the molten Na alloy can be used with a limited ion-exchange membrane size. In this proof-of-concept study, the feasibility of multi-electron transfer redox reactions per active ion and multiple active ions for catholytes has been demonstrated. The critical barriers to mature this new HNFBs have also been explored. PMID:26063629

  10. A multi-electron redox mediator for redox-targeting lithium-sulfur flow batteries

    Science.gov (United States)

    Li, Guochun; Yang, Liuqing; Jiang, Xi; Zhang, Tianran; Lin, Haibin; Yao, Qiaofeng; Lee, Jim Yang

    2018-02-01

    The lithium-sulfur flow battery (LSFB) is a new addition to the rechargeable lithium flow batteries (LFBs) where sulfur or a sulfur compound is used as the cathode material against the lithium anode. We report here our evaluation of an organic sulfide - dimethyl trisulfide (DMTS), as 1) a catholyte of a LFB and 2) a multi-electron redox mediator for discharging and charging a solid sulfur cathode without any conductive additives. The latter configuration is also known as the redox-targeting lithium-sulfur flow battery (RTLSFB). The LFB provides an initial discharge capacity of 131.5 mAh g-1DMTS (1.66 A h L-1), which decreases to 59 mAh g-1DMTS (0.75 A h L-1) after 40 cycles. The RTLSFB delivers a significantly higher application performance - initial discharge capacity of 1225.3 mAh g-1sulfur (3.83 A h L-1), for which 1030.9 mAh g-1sulfur (3.23 A h L-1) is still available after 40 cycles. The significant increase in the discharge and charge duration of the LFB after sulfur addition indicates that DMTS is better used as a redox mediator in a RTLSFB than as a catholyte in a LFB.

  11. 3D printing of natural organic materials by photochemistry

    Science.gov (United States)

    Da Silva Gonçalves, Joyce Laura; Valandro, Silvano Rodrigo; Wu, Hsiu-Fen; Lee, Yi-Hsiung; Mettra, Bastien; Monnereau, Cyrille; Schmitt Cavalheiro, Carla Cristina; Pawlicka, Agnieszka; Focsan, Monica; Lin, Chih-Lang; Baldeck, Patrice L.

    2016-03-01

    In previous works, we have used two-photon induced photochemistry to fabricate 3D microstructures based on proteins, anti-bodies, and enzymes for different types of bio-applications. Among them, we can cite collagen lines to guide the movement of living cells, peptide modified GFP biosensing pads to detect Gram positive bacteria, anti-body pads to determine the type of red blood cells, and trypsin columns in a microfluidic channel to obtain a real time biochemical micro-reactor. In this paper, we report for the first time on two-photon 3D microfabrication of DNA material. We also present our preliminary results on using a commercial 3D printer based on a video projector to polymerize slicing layers of gelatine-objects.

  12. Formation of reactive nitrogen oxides from urban grime photochemistry

    Science.gov (United States)

    Baergen, Alyson M.; Donaldson, D. James

    2016-05-01

    Impervious surfaces are ubiquitous in urban environments and constitute a substrate onto which atmospheric constituents can deposit and undergo photochemical and oxidative processing, giving rise to "urban grime" films. HNO3 and N2O5 are important sinks for NOx in the lower atmosphere and may be deposited onto these films, forming nitrate through surface hydrolysis. Although such deposition has been considered as a net loss of NOx from the atmosphere, there is increasing evidence that surface-associated nitrate undergoes further reaction. Here, we examine the gas phase products of the photochemistry of real, field-collected urban grime using incoherent broadband cavity-enhanced absorption spectroscopy (IBBCEAS). Gas phase nitrogen oxides are emitted upon illumination of grime samples and their production increases with ambient relative humidity (RH) up to 35 % after which the production becomes independent of RH. These results are discussed in the context of water uptake onto and evaporation from grime films.

  13. Fluorescence Spectroscopy, Exciton Dynamics and Photochemistry of Single Allophycocyanin Trimers

    International Nuclear Information System (INIS)

    Ying, Liming; Xie, Xiaoliang

    1998-01-01

    We report a study of the spectroscopy and exciton dynamics of the allophycocyanin trimer (APC), a light harvesting protein complex from cyanobacteria, by room-temperature single-molecule measurements of fluorescence spectra, lifetimes, intensity trajectories and polarization modulation. Emission spectra of individual APC trimers are found to be homogeneous on the time scale of seconds. In contrast, their emission lifetimes are found to be widely distributed, because of generation of exciton traps during the course of measurements. The intensity trajectories and polarization modulation experiments indicate reversible ixciton trap formation within the three quasi-independent pairs of strong interacting a84 and B84 chromophores in APC, as well a photobleaching of individual chromophores. Comparison experiments under continuous wave and pulsed excitation reveal a two-photon mechanism for generating exciton traps and/or photobleaching, which involves exciton-exciton annihilation. These single-molecule experiments provide new insights into exciton dynamics and photochemistry of light-harvesting complexes

  14. Atmospheric chemistry of carboxylic acids: microbial implication versus photochemistry

    Science.gov (United States)

    Vaïtilingom, M.; Charbouillot, T.; Deguillaume, L.; Maisonobe, R.; Parazols, M.; Amato, P.; Sancelme, M.; Delort, A.-M.

    2011-08-01

    The objective of this work was to compare experimentally the contribution of photochemistry vs. microbial activity to the degradation of carboxylic acids present in cloud water. For this, we selected 17 strains representative of the microflora existing in real clouds and worked on two distinct artificial cloud media that reproduce marine and continental cloud chemical composition. Photodegradation experiments with hydrogen peroxide (H2O2) as a source of hydroxyl radicals were performed under the same microcosm conditions using two irradiation systems. Biodegradation and photodegradation rates of acetate, formate, oxalate and succinate were measured on both media at 5 °C and 17 °C and were shown to be on the same order of magnitude (around 10-10-10-11 M s-1). The chemical composition (marine or continental origin) had little influence on photodegradation and biodegradation rates while the temperature shift from 17 °C to 5 °C decreased biodegradation rates of a factor 2 to 5. In order to test other photochemical scenarios, theoretical photodegradation rates were calculated considering hydroxyl (OH) radical concentration values in cloud water estimated by cloud chemistry modelling studies and available reaction rate constants of carboxylic compounds with both hydroxyl and nitrate radicals. Considering high OH concentration ([OH] = 1 × 10-12 M) led to no significant contribution of microbial activity in the destruction of carboxylic acids. On the contrary, for lower OH concentration (at noon, [OH] = 1 × 10-14 M), microorganisms could efficiently compete with photochemistry and in similar contributions than the ones estimated by our experimental approach. Combining these two approaches (experimental and theoretical), our results led to the following conclusions: oxalate was only photodegraded; the photodegradation of formate was usually more efficient than its biodegradation; the biodegradation of acetate and succinate seemed to exceed their photodegradation.

  15. Dust ablation on the giant planets: Consequences for stratospheric photochemistry

    Science.gov (United States)

    Moses, Julianne I.; Poppe, Andrew R.

    2017-11-01

    Ablation of interplanetary dust supplies oxygen to the upper atmospheres of Jupiter, Saturn, Uranus, and Neptune. Using recent dynamical model predictions for the dust influx rates to the giant planets (Poppe et al., 2016), we calculate the ablation profiles and investigate the subsequent coupled oxygen-hydrocarbon neutral photochemistry in the stratospheres of these planets. We find that dust grains from the Edgeworth-Kuiper Belt, Jupiter-family comets, and Oort-cloud comets supply an effective oxygen influx rate of 1.0-0.7+2.2 ×107 O atoms cm-2 s-1 to Jupiter, 7.4-5.1+16 ×104 cm-2 s-1 to Saturn, 8.9-6.1+19 ×104 cm-2 s-1 to Uranus, and 7.5-5.1+16 ×105 cm-2 s-1 to Neptune. The fate of the ablated oxygen depends in part on the molecular/atomic form of the initially delivered products, and on the altitude at which it was deposited. The dominant stratospheric products are CO, H2O, and CO2, which are relatively stable photochemically. Model-data comparisons suggest that interplanetary dust grains deliver an important component of the external oxygen to Jupiter and Uranus but fall far short of the amount needed to explain the CO abundance currently seen in the middle stratospheres of Saturn and Neptune. Our results are consistent with the theory that all of the giant planets have experienced large cometary impacts within the last few hundred years. Our results also suggest that the low background H2O abundance in Jupiter's stratosphere is indicative of effective conversion of meteoric oxygen to CO during or immediately after the ablation process - photochemistry alone cannot efficiently convert the H2O into CO on the giant planets.

  16. Proceedings of the Seventeenth DOE Solar Photochemistry Research Conference

    Energy Technology Data Exchange (ETDEWEB)

    1993-12-31

    The Seventeenth DOE Solar Photochemistry Research Conference sponsored by the Division of Chemical Sciences, Office of Basic Energy Sciences, is being held June 6--10, 1993, at Cragun`s Lodge and Conference Center, Brainerd, Minnesota The meeting is hosted this year by the Ames Laboratory of Iowa State University. The purpose of the meeting is to foster cooperation, collaboration, and exchange of current research ideas among grantees and contractors of the DOE Division of Chemical Sciences engaged in fundamental research on solar photochemical energy conversion. This conference provides a special opportunity for interaction among investigators from diverse traditional chemistry disciplines who share the common good of providing the knowledge and concepts needed for production of low cost fuels and chemicals or electricity by photochemical conversion of solar energy. Our special guest plenary lecturer is Professor Graham Fleming, of the University of Chicago, who will speak on ultrafast spectroscopic studies of molecular dynamics in the condensed phase. The remaining presentations on Monday will feature further investigations of ultrafast phenomena in solvation, electron transfer, and charge separation at interfaces. These will lead into the topical sessions which follow on photosynthesis, molecular models, photoinduced charge transfer in homogeneous and heterogeneous solutions, inorganic photochemistry, and photoelectrochemistry. As an added feature, the photoelectrochemistry session will include six short introductory lectures for the benefit of nonspecialists on outstanding issues and problems in that field. In this volume may be found a copy of the program, the abstracts of 28 formal presentations and 59 posters, as well as an address listing of the 114 participants.

  17. Applications of continuous-flow photochemistry in organic synthesis, material science, and water treatment

    NARCIS (Netherlands)

    Cambié, D.; Bottecchia, C.; Straathof, N.J.W.; Hessel, V.; Noël, T.

    2016-01-01

    Continuous-flow photochemistry in microreactors receives a lot of attention from researchers in academia and industry as this technology provides reduced reaction times, higher selectivities, straightforward scalability, and the possibility to safely use hazardous intermediates and gaseous

  18. Electron emission relevant to inner-shell photoionization of condensed water studied by multi-electron coincidence spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Hikosaka, Y., E-mail: hikosaka@las.u-toyama.ac.jp [Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Toyama 930-0194 (Japan); Mashiko, R.; Konosu, Y.; Soejima, K. [Department of Environmental Science, Niigata University, Niigata 950-2181 (Japan); Shigemasa, E. [UVSOR Facility, Institute for Molecular Science, Okazaki 444-8585 (Japan); SOKENDAI, Okazaki 444-8585 (Japan)

    2016-11-15

    Highlights: • Multi-electron coincidence spectroscopy is applied to the study of electron emissions from condensed H2O molecules. • Coincidence Auger spectra are obtained for different photoelectron energies. • The energy distribution of the slow electrons ejected in the Auger decay is deduced from three-fold coincidences. - Abstract: Multi-electron coincidence spectroscopy using a magnetic-bottle electron spectrometer has been applied to the study of the Auger decay following O1s photoionization of condensed H{sub 2}O molecules. Coincidence Auger spectra are obtained for three different photoelectron energy ranges. In addition, the energy distribution of the slow electrons ejected in the Auger decay of the O1s core hole is deduced from three-fold coincidences.

  19. Microelectrode voltammetry of multi-electron transfers complicated by coupled chemical equilibria: a general theory for the extended square scheme.

    Science.gov (United States)

    Laborda, Eduardo; Gómez-Gil, José María; Molina, Angela

    2017-06-28

    A very general and simple theoretical solution is presented for the current-potential-time response of reversible multi-electron transfer processes complicated by homogeneous chemical equilibria (the so-called extended square scheme). The expressions presented here are applicable regardless of the number of electrons transferred and coupled chemical processes, and they are particularized for a wide variety of microelectrode geometries. The voltammetric response of very different systems presenting multi-electron transfers is considered for the most widely-used techniques (namely, cyclic voltammetry, square wave voltammetry, differential pulse voltammetry and steady state voltammetry), studying the influence of the microelectrode geometry and the number and thermodynamics of the (electro)chemical steps. Most appropriate techniques and procedures for the determination of the 'interaction' between successive transfers are discussed. Special attention is paid to those situations where homogeneous chemical processes, such as protonation, complexation or ion association, affect the electrochemical behaviour of the system by different stabilization of the oxidation states.

  20. Atmospheric chemistry of carboxylic acids: microbial implication versus photochemistry

    Directory of Open Access Journals (Sweden)

    M. Vaïtilingom

    2011-08-01

    Full Text Available The objective of this work was to compare experimentally the contribution of photochemistry vs. microbial activity to the degradation of carboxylic acids present in cloud water. For this, we selected 17 strains representative of the microflora existing in real clouds and worked on two distinct artificial cloud media that reproduce marine and continental cloud chemical composition. Photodegradation experiments with hydrogen peroxide (H2O2 as a source of hydroxyl radicals were performed under the same microcosm conditions using two irradiation systems. Biodegradation and photodegradation rates of acetate, formate, oxalate and succinate were measured on both media at 5 °C and 17 °C and were shown to be on the same order of magnitude (around 10−10–10−11 M s−1. The chemical composition (marine or continental origin had little influence on photodegradation and biodegradation rates while the temperature shift from 17 °C to 5 °C decreased biodegradation rates of a factor 2 to 5.

    In order to test other photochemical scenarios, theoretical photodegradation rates were calculated considering hydroxyl (OH radical concentration values in cloud water estimated by cloud chemistry modelling studies and available reaction rate constants of carboxylic compounds with both hydroxyl and nitrate radicals. Considering high OH concentration ([OH] = 1 × 10−12 M led to no significant contribution of microbial activity in the destruction of carboxylic acids. On the contrary, for lower OH concentration (at noon, [OH] = 1 × 10−14 M, microorganisms could efficiently compete with photochemistry and in similar contributions than the ones estimated by our experimental approach.

    Combining these two approaches (experimental and theoretical, our results led to the following conclusions: oxalate was only photodegraded; the photodegradation of formate was usually more

  1. Photodynamic Efficiency: From Molecular Photochemistry to Cell Death

    Directory of Open Access Journals (Sweden)

    Isabel O. L. Bacellar

    2015-08-01

    Full Text Available Photodynamic therapy (PDT is a clinical modality used to treat cancer and infectious diseases. The main agent is the photosensitizer (PS, which is excited by light and converted to a triplet excited state. This latter species leads to the formation of singlet oxygen and radicals that oxidize biomolecules. The main motivation for this review is to suggest alternatives for achieving high-efficiency PDT protocols, by taking advantage of knowledge on the chemical and biological processes taking place during and after photosensitization. We defend that in order to obtain specific mechanisms of cell death and maximize PDT efficiency, PSes should oxidize specific molecular targets. We consider the role of subcellular localization, how PS photochemistry and photophysics can change according to its nanoenvironment, and how can all these trigger specific cell death mechanisms. We propose that in order to develop PSes that will cause a breakthrough enhancement in the efficiency of PDT, researchers should first consider tissue and intracellular localization, instead of trying to maximize singlet oxygen quantum yields in in vitro tests. In addition to this, we also indicate many open questions and challenges remaining in this field, hoping to encourage future research.

  2. On the photophysics and photochemistry of the water dimer

    Energy Technology Data Exchange (ETDEWEB)

    Segarra-Marti, Javier; Merchan, Manuela [Instituto de Ciencia Molecular, Universitat de Valencia, P.O. Box 22085, 46071 Valencia (Spain); Roca-Sanjuan, Daniel; Lindh, Roland [Department of Chemistry - Angstroem, Theoretical Chemistry Program, Uppsala University, Box 518, 75120 Uppsala (Sweden)

    2012-12-28

    The photochemistry of the water dimer irradiated by UV light is studied by means of the complete active space perturbation theory//complete active space self-consistent field (CASPT2//CASSCF) method and accurate computational approaches like as minimum energy paths. Both electronic structure computations and ab initio molecular dynamics simulations are carried out. The results obtained show small shifts relative to a single water molecule on the vertical excitation energies of the dimer due to the hydrogen bond placed between the water donor (W{sub D}) and the water acceptor (W{sub A}). A red-shift and a blue-shift are predicted for the W{sub D} and W{sub A}, respectively, supporting previous theoretical and experimental results. The photoinduced chemistry of the water dimer is described as a process occurring between two single water molecules in which the effect of the hydrogen bond plays a minor role. Thus, the photoinduced decay routes correspond to two photodissociation processes, one for each water molecule. The proposed mechanism for the decay channels of the lowest-lying excited states of the system is established as the photochemical production of a hydrogen-bonded H{sub 2}O Horizontal-Ellipsis HO species plus a hydrogen H atom.

  3. The photochemistry of ring-substituted cinnamyl acetates

    International Nuclear Information System (INIS)

    Fleming, S.A.; Renault, L.; Grundy, E.C.; Pincock, J.A.

    2006-01-01

    The photochemistry of the (E)-cinnamyl acetates ((E)-1-aryl-3-propenyl acetates, 8a-8e) with substituents H, 4-CH 3 O, 3-CH 3 O, 4-CF 3 , and 3-CF 3 , respectively, was examined in both cyclohexane and methanol solvents. Alkene isomerization (E to Z) occurred more efficiently than other reactions and evidence is presented that this process occurs from the excited triplet state. In a slower process, 1,3-migration of the acetoxy group led to the rearranged 3-aryl-3-propenyl acetate isomers (9a-9e) as the major pathway, particularly in cylohexane. In methanol, the isomeric ethers 3-aryl-3-methoxypropene (14) and 1-aryl-3-methoxypropene (15) were formed by reaction of methanol with the photochemically generated cation. The combined yield of 14 and 15 (95% and 5%, respectively) was quantitative for the 4-methoxyphenyl compound (8b). Independent irradiations of the isomers 9a-9c demonstrated that the ethers 14 and 15 were primary photoproducts from 8 and not secondary photoproducts from 9. Fluorescence quantum yields and excited singlet state lifetimes indicated that the reactions, other than the E to Z isomerization, are from the excited singlet state. (author)

  4. Rice Photosynthetic Productivity and PSII Photochemistry under Nonflooded Irrigation

    Directory of Open Access Journals (Sweden)

    Haibing He

    2014-01-01

    Full Text Available Nonflooded irrigation is an important water-saving rice cultivation technology, but little is known on its photosynthetic mechanism. The aims of this work were to investigate photosynthetic characteristics of rice during grain filling stage under three nonflooded irrigation treatments: furrow irrigation with plastic mulching (FIM, furrow irrigation with nonmulching (FIN, and drip irrigation with plastic mulching (DI. Compared with the conventional flooding (CF treatment, those grown in the nonflooded irrigation treatments showed lower net photosynthetic rate (PN, lower maximum quantum yield (Fv/Fm, and lower effective quantum yield of PSII photochemistry (ΦPSII. And the poor photosynthetic characteristics in the nonflooded irrigation treatments were mainly attributed to the low total nitrogen content (TNC. Under non-flooded irrigation, the PN, Fv/Fm, and ΦPSII significantly decreased with a reduction in the soil water potential, but these parameters were rapidly recovered in the DI and FIM treatments when supplementary irrigation was applied. Moreover, The DI treatment always had higher photosynthetic productivity than the FIM and FIN treatments. Grain yield, matter translocation, and dry matter post-anthesis (DMPA were the highest in the CF treatment, followed by the DI, FIM, and FIN treatments in turn. In conclusion, increasing nitrogen content in leaf of rice plants could be a key factor to improve photosynthetic capacity in nonflooded irrigation.

  5. The photochemistry of neptunium in aqueous perchloric acid solutions

    International Nuclear Information System (INIS)

    Friedman, H.A.; Toth, L.M.; Osborne, M.M.

    1979-01-01

    The photochemistry of neptunium ions in aqueous perchloric acid has been investigated using 254 and 300 nm UV radiation. In the absence of other reagents, Np(IV) and (V) oxidized to Np(VI), in a stepwise fashion, with individual quantum efficiencies for each step that vary from 0.02 to 0.004. Decreasing acid concentration favors the Np(IV) → Np(V) reaction whereas it hinders the Np(V) → Np(VI) photo-oxidation. When ethanol, acetaldehyde and other mild reducing agents are added to neptunium-perchloric acid solutions which are then photolyzed, the Np species are reduced to Np(III) in a stepwise fashion with individual quantum efficiencies that vary from 0.07 to 0.006. The overall photoredox reactions of neptunium are subject to competing secondary product reactions that become significant as the photolysis products accumulate. Absorption spectrophotometry was used to monitor the changes in Np oxidation states and reference spectra of the various Np oxidation states are given for 1.0 N HClO 4 . The Np species have absorption bands in the 300 to 1320 nm region that obey Beer's law only when they were properly resolved. (author)

  6. Soft x-ray photochemistry in solid surfaces

    International Nuclear Information System (INIS)

    Sekiguchi, Tetsuhiro; Baba, Yuji

    2000-01-01

    Resent studies on photochemistry using synchrotron soft x-rays in solid surfaces are reviewed. A type of site-selective chemical reaction induced by inner-shell excitation is classified into two model systems that are referred to as 'Element-specific fragmentation' and 'Bonding-site-specific dissociation.' The former system uses difference of core-binding-energies in different elements and the latter is based on the existence of plural unoccupied molecular orbitals with different antibonding character. The selectivity of the reaction in respective systems is discussed in terms of mass-patterns of desorbed fragment-ions and photon-energy dependence of the ion yields. Also discussed are the fragmentation and desorption mechanisms which include intrinsic direct photofragmentation and indirect channels induced by secondary electrons. The latter process reduces the selectivity of the reaction. Furthermore, two experimental approaches, which have recently been performed to estimate the relative magnitude of contribution in the direct and indirect processes to the total yields, are described: (1) the layer-thickness dependence and (2) polarization-angle dependence in the photofragmentation. (author)

  7. Photochemistry in the Atmospheres of Denver and Mexico City

    Science.gov (United States)

    Cantrell, C. A.

    2016-12-01

    The composition of atmospheres in and downwind of urban centers has been the subject of study for decades. While early campaigns involved measurements exclusively from the ground, more recent studies have included airborne-based observations. Improved understanding has hinged critically on the development of instrumentation for better qualitifcation of pollutants, and measurement of previously unobserved species in the gas and particulate phases. Comprehensive, well-planned studies have, over time, led to more detailed understanding of chemical transformations and thus improved model representations and directions for further research. This presentation focuses on findings from two case studies of urban atmospheres, namely the MILAGRO study in the Mexico City metropolitan area and the FRAPPE study in the Denver metropolitan region. Both studies made use of extensive ground-based networks and multiple aircraft platforms. The data collected during these studies have been combined with numerical models to derive assessments of the evolution of atmospheric composition due to photochemistry, mixing, and surface processes. Here, analysis of MILAGRO data focuses on the evolution of outflow downwind of the urban region. In FRAPPE, the focus is the possible role of oil and gas exploration on urban air quality. These findings are used to assess the accuracy of current numerical models to reproduce observations, and to point toward areas possibly needing further study.

  8. Studies in organic and physical photochemistry - an interdisciplinary approach.

    Science.gov (United States)

    Oelgemöller, Michael; Hoffmann, Norbert

    2016-08-21

    Traditionally, organic photochemistry when applied to synthesis strongly interacts with physical chemistry. The aim of this review is to illustrate this very fruitful interdisciplinary approach and cooperation. A profound understanding of the photochemical reactivity and reaction mechanisms is particularly helpful for optimization and application of these reactions. Some typical reactions and particular aspects are reported such as the Norrish-Type II reaction and the Yang cyclization and related transformations, the [2 + 2] photocycloadditions, particularly the Paternò-Büchi reaction, photochemical electron transfer induced transformations, different kinds of catalytic reactions such as photoredox catalysis for organic synthesis and photooxygenation are discussed. Particular aspects such as the structure and reactivity of aryl cations, photochemical reactions in the crystalline state, chiral memory, different mechanisms of hydrogen transfer in photochemical reactions or fundamental aspects of stereoselectivity are discussed. Photochemical reactions are also investigated in the context of chemical engineering. Particularly, continuous flow reactors are of interest. Novel reactor systems are developed and modeling of photochemical transformations and different reactors play a key role in such studies. This research domain builds a bridge between fundamental studies of organic photochemical reactions and their industrial application.

  9. New Equations for Calculating Principal and Fine-Structure Atomic Spectra for Single and Multi-Electron Atoms

    Energy Technology Data Exchange (ETDEWEB)

    Surdoval, Wayne A. [National Energy Technology Lab. (NETL), Pittsburgh, PA, (United States); Berry, David A. [National Energy Technology Lab. (NETL), Morgantown, WV (United States); Shultz, Travis R. [National Energy Technology Lab. (NETL), Morgantown, WV (United States)

    2018-03-09

    A set of equations are presented for calculating atomic principal spectral lines and fine-structure energy splits for single and multi-electron atoms. Calculated results are presented and compared to the National Institute of Science and Technology database demonstrating very good accuracy. The equations do not require fitted parameters. The only experimental parameter required is the Ionization energy for the electron of interest. The equations have comparable accuracy and broader applicability than the single electron Dirac equation. Three Appendices discuss the origin of the new equations and present calculated results. New insights into the special relativistic nature of the Dirac equation and its relationship to the new equations are presented.

  10. Adenine and 2-aminopurine: paradigms of modern theoretical photochemistry.

    Science.gov (United States)

    Serrano-Andrés, Luis; Merchán, Manuela; Borin, Antonio C

    2006-06-06

    Distinct photophysical behavior of nucleobase adenine and its constitutional isomer, 2-aminopurine, has been studied by using quantum chemical methods, in particular an accurate ab initio multiconfigurational second-order perturbation theory. After light irradiation, the efficient, ultrafast energy dissipation observed for nonfluorescent 9H-adenine is explained here by the nonradiative internal conversion process taking place along a barrierless reaction path from the initially populated 1(pipi* La) excited state toward a low-lying conical intersection (CI) connected with the ground state. In contrast, the strong fluorescence recorded for 2-aminopurine at 4.0 eV with large decay lifetime is interpreted by the presence of a minimum in the 1(pipi* La) hypersurface lying below the lowest CI and the subsequent potential energy barrier required to reach the funnel to the ground state. Secondary deactivation channels were found in the two systems related to additional CIs involving the 1(pipi* Lb) and 1(npi*) states. Although in 9H-adenine a population switch between both states is proposed, in 7H-adenine this may be perturbed by a relatively larger barrier to access the 1(npi*) state, and, therefore, the 1(pipi* Lb) state becomes responsible for the weak fluorescence measured in aqueous adenine at approximately 4.5 eV. In contrast to previous models that explained fluorescence quenching in adenine, unlike in 2-aminopurine, on the basis of the vibronic coupling of the nearby 1(pipi*) and 1(npi*) states, the present results indicate that the 1(npi*) state does not contribute to the leading photophysical event and establish the prevalence of a model based on the CI concept in modern photochemistry.

  11. Performance and cost characteristics of multi-electron transfer, common ion exchange non-aqueous redox flow batteries

    Science.gov (United States)

    Laramie, Sydney M.; Milshtein, Jarrod D.; Breault, Tanya M.; Brushett, Fikile R.; Thompson, Levi T.

    2016-09-01

    Non-aqueous redox flow batteries (NAqRFBs) have recently received considerable attention as promising high energy density, low cost grid-level energy storage technologies. Despite these attractive features, NAqRFBs are still at an early stage of development and innovative design techniques are necessary to improve performance and decrease costs. In this work, we investigate multi-electron transfer, common ion exchange NAqRFBs. Common ion systems decrease the supporting electrolyte requirement, which subsequently improves active material solubility and decreases electrolyte cost. Voltammetric and electrolytic techniques are used to study the electrochemical performance and chemical compatibility of model redox active materials, iron (II) tris(2,2‧-bipyridine) tetrafluoroborate (Fe(bpy)3(BF4)2) and ferrocenylmethyl dimethyl ethyl ammonium tetrafluoroborate (Fc1N112-BF4). These results help disentangle complex cycling behavior observed in flow cell experiments. Further, a simple techno-economic model demonstrates the cost benefits of employing common ion exchange NAqRFBs, afforded by decreasing the salt and solvent contributions to total chemical cost. This study highlights two new concepts, common ion exchange and multi-electron transfer, for NAqRFBs through a demonstration flow cell employing model active species. In addition, the compatibility analysis developed for asymmetric chemistries can apply to other promising species, including organics, metal coordination complexes (MCCs) and mixed MCC/organic systems, enabling the design of low cost NAqRFBs.

  12. Selected topics in photochemistry of nucleic acids. Recent results and perspectives

    International Nuclear Information System (INIS)

    Loeber, G.; Kittler, L.

    1977-01-01

    Recent results on the following photoreactions of nucleic acids are reported: photochemistry of aza-bases and minor bases, formation of photoproducts of the non-cyclobutane type, formations of furocoumarin-pyrimidine photoadducts, fluorescence of dye-nucleic acid complexes and their role in chromosomal fluorescence staining, and mechanisms of the photochemical reaction. Results are discussed with respect to: (i) photobiological relevance of light-induced defects in nucleic acids; (ii) possibilities of achieving higher selectivity of light-induced defects in nucleic acids; (iii) the use of nucleic acid photochemistry to analyze genetic material. An extensive bibliography is included. (author)

  13. Applications of Continuous-Flow Photochemistry in Organic Synthesis, Material Science, and Water Treatment.

    Science.gov (United States)

    Cambié, Dario; Bottecchia, Cecilia; Straathof, Natan J W; Hessel, Volker; Noël, Timothy

    2016-09-14

    Continuous-flow photochemistry in microreactors receives a lot of attention from researchers in academia and industry as this technology provides reduced reaction times, higher selectivities, straightforward scalability, and the possibility to safely use hazardous intermediates and gaseous reactants. In this review, an up-to-date overview is given of photochemical transformations in continuous-flow reactors, including applications in organic synthesis, material science, and water treatment. In addition, the advantages of continuous-flow photochemistry are pointed out and a thorough comparison with batch processing is presented.

  14. Photochemistry, mixing and transport in Jupiter's stratosphere constrained by Cassini

    Science.gov (United States)

    Hue, V.; Hersant, F.; Cavalié, T.; Dobrijevic, M.; Sinclair, J. A.

    2018-06-01

    In this work, we aim at constraining the diffusive and advective transport processes in Jupiter's stratosphere, using Cassini/CIRS observations published by Nixon et al. (2007,2010). The Cassini-Huygens flyby of Jupiter on December 2000 provided the highest spatially resolved IR observations of Jupiter so far, with the CIRS instrument. The IR spectrum contains the fingerprints of several atmospheric constituents and allows probing the tropospheric and stratospheric composition. In particular, the abundances of C2H2 and C2H6, the main compounds produced by methane photochemistry, can be retrieved as a function of latitude in the pressure range at which CIRS is sensitive to. CIRS observations suggest a very different meridional distribution for these two species. This is difficult to reconcile with their photochemical histories, which are thought to be tightly coupled to the methane photolysis. While the overall abundance of C2H2 decreases with latitude, C2H6 becomes more abundant at high latitudes. In this work, a new 2D (latitude-altitude) seasonal photochemical model of Jupiter is developed. The model is used to investigate whether the addition of stratospheric transport processes, such as meridional diffusion and advection, are able to explain the latitudinal behavior of C2H2 and C2H6. We find that the C2H2 observations are fairly well reproduced without meridional diffusion. Adding meridional diffusion to the model provides an improved agreement with the C2H6 observations by flattening its meridional distribution, at the cost of a degradation of the fit to the C2H2 distribution. However, meridional diffusion alone cannot produce the observed increase with latitude of the C2H6 abundance. When adding 2D advective transport between roughly 30 mbar and 0.01 mbar, with upwelling winds at the equator and downwelling winds at high latitudes, we can, for the first time, reproduce the C2H6 abundance increase with latitude. In parallel, the fit to the C2H2 distribution is

  15. Kinetics and Photochemistry of Ruthenium Bisbipyridine Diacetonitrile Complexes: An Interdisciplinary Inorganic and Physical Chemistry Laboratory Exercise

    Science.gov (United States)

    Rapp, Teresa L.; Phillips, Susan R.; Dmochowski, Ivan J.

    2016-01-01

    The study of ruthenium polypyridyl complexes can be widely applied across disciplines in the undergraduate curriculum. Ruthenium photochemistry has advanced many fields including dye-sensitized solar cells, photoredox catalysis, lightdriven water oxidation, and biological electron transfer. Equally promising are ruthenium polypyridyl complexes…

  16. Photochemistry of Nitrophenol Molecules and Clusters: Intra- vs Intermolecular Hydrogen Bond Dynamics

    Czech Academy of Sciences Publication Activity Database

    Grygoryeva, Kateřina; Kubečka, J.; Pysanenko, Andriy; Lengyel, Jozef; Slavíček, Petr; Fárník, Michal

    2016-01-01

    Roč. 120, č. 24 (2016), s. 4139-4146 ISSN 1089-5639 R&D Projects: GA ČR(CZ) GA15-12386S Institutional support: RVO:61388955 Keywords : photochemistry * clusters * laser techniques Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 2.847, year: 2016

  17. Selected Contributions of the 4th International Conference on Semiconductor Photochemistry (5P4) Introduction.

    Czech Academy of Sciences Publication Activity Database

    Krýsa, J.; Klusoň, Petr; Malato, S.

    2014-01-01

    Roč. 230, JUL 2014 (2014), s. 1 ISSN 0920-5861 Grant - others:SMEC(ES) CTQ2012-38754-C03-01 Institutional support: RVO:67985858 Keywords : semiconductor photochemistry * catalysis * scientific applications Subject RIV: CC - Organic Chemistry OBOR OECD: Organic chemistry Impact factor: 3.893, year: 2014

  18. On the involvement of single-bond rotation in the primary photochemistry of photoactive yellow protein

    NARCIS (Netherlands)

    Stahl, A.D.; Hospes, M.; Singhal, K.; van Stokkum, I.; van Grondelle, R.; Groot, M.L.; Hellingwerf, K.J.

    2011-01-01

    Prior experimental observations, as well as theoretical considerations, have led to the proposal that C4-C7 single-bond rotation may play an important role in the primary photochemistry of photoactive yellow protein (PYP). We therefore synthesized an analog of this protein's 4-hydroxy-cinnamic acid

  19. PHOTOCHEMISTRY IN TERRESTRIAL EXOPLANET ATMOSPHERES. II. H{sub 2}S AND SO{sub 2} PHOTOCHEMISTRY IN ANOXIC ATMOSPHERES

    Energy Technology Data Exchange (ETDEWEB)

    Hu Renyu; Seager, Sara; Bains, William, E-mail: hury@mit.edu [Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States)

    2013-05-20

    Sulfur gases are common components in the volcanic and biological emission on Earth, and are expected to be important input gases for atmospheres on terrestrial exoplanets. We study the atmospheric composition and the spectra of terrestrial exoplanets with sulfur compounds (i.e., H{sub 2}S and SO{sub 2}) emitted from their surfaces. We use a comprehensive one-dimensional photochemistry model and radiative transfer model to investigate the sulfur chemistry in atmospheres ranging from reducing to oxidizing. The most important finding is that both H{sub 2}S and SO{sub 2} are chemically short-lived in virtually all types of atmospheres on terrestrial exoplanets, based on models of H{sub 2}, N{sub 2}, and CO{sub 2} atmospheres. This implies that direct detection of surface sulfur emission is unlikely, as their surface emission rates need to be extremely high (>1000 times Earth's volcanic sulfur emission) for these gases to build up to a detectable level. We also find that sulfur compounds emitted from the surface lead to photochemical formation of elemental sulfur and sulfuric acid in the atmosphere, which would condense to form aerosols if saturated. For terrestrial exoplanets in the habitable zone of Sun-like stars or M stars, Earth-like sulfur emission rates result in optically thick haze composed of elemental sulfur in reducing H{sub 2}-dominated atmospheres for a wide range of particle diameters (0.1-1 {mu}m), which is assumed as a free parameter in our simulations. In oxidized atmospheres composed of N{sub 2} and CO{sub 2}, optically thick haze, composed of elemental sulfur aerosols (S{sub 8}) or sulfuric acid aerosols (H{sub 2}SO{sub 4}), will form if the surface sulfur emission is two orders of magnitude more than the volcanic sulfur emission of Earth. Although direct detection of H{sub 2}S and SO{sub 2} by their spectral features is unlikely, their emission might be inferred by observing aerosol-related features in reflected light with future generation

  20. The impact of urban canopy meteorological forcing on summer photochemistry

    Science.gov (United States)

    Huszár, Peter; Karlický, Jan; Belda, Michal; Halenka, Tomáš; Pišoft, Petr

    2018-03-01

    The regional climate model RegCM4.4, including the surface model CLM4.5, was offline coupled to the chemistry transport model CAMx version 6.30 in order to investigate the impact of the urban canopy induced meteorological changes on the longterm summer photochemistry over central Europe for the 2001-2005 period. First, the urban canopy impact on the meteorological conditions was calculated performing a reference experiment without urban landsurface considered and an experiment with urban surfaces modeled with the urban parameterization within the CLM4.5 model. In accordance with expectations, strong increases of urban surface temperatures (up to 2-3 K), decreases of wind speed (up to -1 ms-1) and increases of vertical turbulent diffusion coefficient (up to 60-70 m2s-1) were found. For the impact on chemistry, these three components were considered. Additionally, we accounted for the effect of temperature enhanced biogenic emission increase. Several experiments were performed by adding these effects one-by-one to the total impact: i.e., first, only the urban temperature impact was considered driving the chemistry model; secondly, the wind impact was added and so on. We found that the impact on biogenic emission account for minor changes in the concentrations of ozone (O3), oxides of nitrogen NOx = NO + NO2 and nitric acid (HNO3). On the other hand, the dominating component acting is the increased vertical mixing, resulting in up to 5 ppbv increase of urban ozone concentrations while causing -2 to -3 ppbv decreases and around 1 ppbv increases of NOx and HNO3 surface concentrations, respectively. The temperature impact alone results in reduction of ozone, increase in NO, decrease in NO2 and increases of HNO3. The wind impact leads, over urban areas, to ozone decreases, increases of NOx and a slight increase in HNO3. The overall impact is similar to the impact of increased vertical mixing alone. The Process Analysis (PA) technique implemented in CAMx was adopted to

  1. 2009 Gordon Research Conference on Photochemistry: Formal Schedule and Speaker/Poster Program

    Energy Technology Data Exchange (ETDEWEB)

    Wasielewski, Michael [Northwestern Univ., Evanston, IL (United States)

    2009-07-05

    The impact of photochemistry on diverse fields ranging from materials and environmental science to biology and medicine has never been greater. The 2009 Gordon Conference on Photochemistry will highlight recent advances in these key areas while also presenting the latest research on new photochemical reactions and mechanistic studies. Session topics will include: development of new chromophores, light harvesting materials, solar energy conversion, photocontrolled biomolecules, light-triggered amplification reactions, and advanced bioimaging techniques. The Conference will continue its 45 year history of promoting interactions between fundamental and applied scientists, a hallmark of the Gordon Conferences. In addition, oral presentations, poster sessions and informal discussions will provide opportunities for junior scientists and students to present their own work and discuss their results with leaders in the field. Applicants to the Conference are encouraged to submit abstracts for poster presentations in order to gain visibility and feedback on their research. In addition, a number of poster abstracts will be selected for presentation as short talks.

  2. Photochemistry of the ozone-water complex in cryogenic neon, argon, and krypton matrixes.

    Science.gov (United States)

    Tsuge, Masashi; Tsuji, Kazuhide; Kawai, Akio; Shibuya, Kazuhiko

    2013-12-12

    The photochemistry of ozone-water complexes and the wavelength dependence of the reactions were studied by matrix isolation FTIR spectrometry in neon, argon, and krypton matrixes. Hydrogen peroxide was formed upon the irradiation of UV light below 355 nm. Quantitative analyses of the reactant and product were performed to evaluate the matrix cage effect of the photoreaction. In argon and krypton matrixes, a bimolecular O((1)D) + H2O → H2O2 reaction was found to occur to form hydrogen peroxide, where the O((1)D) atom generated by the photolysis of ozone diffused in the cryogenic solids to encounter water. In a neon matrix, hydrogen peroxide was generated through intracage photoreaction of the ozone-water complex, indicating that a neon matrix medium is most appropriate to study the photochemistry of the ozone-water complex.

  3. An overview of aquatic photochemistry as it relates to microbial production

    Energy Technology Data Exchange (ETDEWEB)

    Miller, W.L. [Dalhousie Univ., Halifax, NS (Canada). Inst. of Oceanography

    2000-07-01

    A review of fundamental photochemistry and its potential impact on microbial processes in natural waters was presented. It is a known fact that solar radiation alters chromophoric dissolved organic matter (CDOM) and results in the production of a complex mixture of reactive oxygen species, inorganic nutrients, and carbon photoproducts. In addition, it results in reduced average molecular weight and changes in water optical properties. The largest carbon product results from the direct photo-mineralization of dissolved organic carbon (DOC) to dissolved inorganic carbon (DIC), thereby bypassing the microbial web. Other studies demonstrated that growth was enhanced for heterotrophic bacteria in natural samples exposed to sunlight, that bacterial growth was absent when stimulated by photochemistry and that there was a marked reduction in the ability of DOC to support bacterial growth after exposure to ultraviolet radiation B (UV-B). 20 refs., 1 fig.

  4. High-Power 365 nm UV LED Mercury Arc Lamp Replacement for Photochemistry and Chemical Photolithography

    OpenAIRE

    H?lz, K.; Lietard, J.; Somoza, M. M.

    2016-01-01

    Ultraviolet light emitting diodes (UV LEDs) have become widespread in chemical research as highly efficient light sources for photochemistry and photopolymerization. However, in more complex experimental setups requiring highly concentrated light and highly spatially resolved patterning of the light, high-pressure mercury arc lamps are still widely used because they emit intense UV light from a compact arc volume that can be efficiently coupled into optical systems. Advances in the deposition...

  5. Solar photochemistry - twenty years of progress, what`s been accomplished, and where does it lead?

    Energy Technology Data Exchange (ETDEWEB)

    Blake, D M

    1995-01-01

    It has been more than 20 years since the first oil embargo. That event created an awareness of the need for alternative sources of energy and renewed interest in combining sunlight and chemistry to produce the chemicals and materials required by industry. This paper will review approaches that have been taken, progress that has been made, and give some projections for the near and longer term prospects for commercialization of solar photochemistry.

  6. Ultrafast Infrared and UV-vis Studies of the Photochemistry of Methoxycarbonylphenyl Azides in Solution

    OpenAIRE

    Xue, Jiadan; Luk, Hoi Ling; Eswaran, S. V.; Hadad, Christopher M.; Platz, Matthew S.

    2012-01-01

    The photochemistry of 4-methoxycarbonylphenyl azide (2a), 2-methoxycarbonylphenyl azide (3a) and 2-methoxy-6-methoxycarbonylphenyl azide (4a) were studied by ultrafast time-resolved infrared (IR) and UV-vis spectroscopies in solution. Singlet nitrenes and ketenimines were observed and characterized for all three azides. Isoxazole species 3g and 4g are generated after photolysis of 3a and 4a, respectively, in acetonitrile. Triplet nitrene 4e formation correlated with the decay of singlet nitre...

  7. A combined continuous microflow photochemistry and asymmetric organocatalysis approach for the enantioselective synthesis of tetrahydroquinolines

    Directory of Open Access Journals (Sweden)

    Erli Sugiono

    2013-11-01

    Full Text Available A continuous-flow asymmetric organocatalytic photocyclization–transfer hydrogenation cascade reaction has been developed. The new protocol allows the synthesis of tetrahydroquinolines from readily available 2-aminochalcones using a combination of photochemistry and asymmetric Brønsted acid catalysis. The photocylization and subsequent reduction was performed with catalytic amount of chiral BINOL derived phosphoric acid diester and Hantzsch dihydropyridine as hydrogen source providing the desired products in good yields and with excellent enantioselectivities.

  8. Matrix photochemistry of small molecules: Influencing reaction dynamics on electronically excited hypersurfaces

    Energy Technology Data Exchange (ETDEWEB)

    Laursen, S.L.

    1990-01-01

    Investigations of chemical reactions on electronically excited reaction surfaces are presented. The role of excited-surface multiplicity is of particular interest, as are chemical reactivity and energy transfer in systems in which photochemistry is initiated through a metal atom sensitizer.'' Two approaches are employed: A heavy-atom matrix affords access to forbidden triplet reaction surfaces, eliminating the need for a potentially reactive sensitizer. Later, the role of the metal atom in the photosensitization process is examined directly.

  9. Solar eclipse demonstrating the importance of photochemistry in new particle formation

    OpenAIRE

    Jokinen, Tuija; Kontkanen, Jenni; Lehtipalo, Katrianne; Manninen, Hanna E.; Aalto, Juho; Porcar-Castell, Albert; Garmash, Olga; Nieminen, Tuomo; Ehn, Mikael; Kangasluoma, Juha; Junninen, Heikki; Levula, Janne; Duplissy, Jonathan; Ahonen, Lauri R.; Rantala, Pekka

    2017-01-01

    Solar eclipses provide unique possibilities to investigate atmospheric processes, such as new particle formation (NPF), important to the global aerosol load and radiative balance. The temporary absence of solar radiation gives particular insight into different oxidation and clustering processes leading to NPF. This is crucial because our mechanistic understanding on how NPF is related to photochemistry is still rather limited. During a partial solar eclipse over Finland in 2015, we found that...

  10. Matrix photochemistry of small molecules: Influencing reaction dynamics on electronically excited hypersurfaces

    International Nuclear Information System (INIS)

    Laursen, S.L.

    1990-01-01

    Investigations of chemical reactions on electronically excited reaction surfaces are presented. The role of excited-surface multiplicity is of particular interest, as are chemical reactivity and energy transfer in systems in which photochemistry is initiated through a metal atom ''sensitizer.'' Two approaches are employed: A heavy-atom matrix affords access to forbidden triplet reaction surfaces, eliminating the need for a potentially reactive sensitizer. Later, the role of the metal atom in the photosensitization process is examined directly

  11. Separation and enrichment of isotopes using laser photochemistry - fundamentals and prospectives

    International Nuclear Information System (INIS)

    Guesten, H.

    1978-01-01

    Basic knowledge is summed up on isotope separation by laser photochemistry. The principal prerequisites are explained of the application of atomic and molecular spectroscopy for this purpose. Practical examples are given of isotope separation of uranium, nitrogen, chlorine, carbon, sulfur, and molybdenum showing the application of two basic techniques, i.e., of gradual atom photoionization or gradual molecule photodissociation and of selective photochemical reactions. (L.K.)

  12. Microwave Photochemistry IV: Preparation of the Electrodeless Discharge Lamps for Photochemical Applications

    Czech Academy of Sciences Publication Activity Database

    Církva, Vladimír; Vlková, Leona; Relich, Stanislav; Hájek, Milan

    2006-01-01

    Roč. 179, 1-2 (2006), s. 229-233 ISSN 1010-6030 R&D Projects: GA AV ČR KSK4040110; GA ČR GA203/02/0879 Institutional research plan: CEZ:AV0Z40720504 Keywords : microwave photochemistry * electrodeless discharge lamp * uv/vis source Subject RIV: CC - Organic Chemistry Impact factor: 2.098, year: 2006

  13. Delayed electron emission in strong-field driven tunnelling from a metallic nanotip in the multi-electron regime

    Science.gov (United States)

    Yanagisawa, Hirofumi; Schnepp, Sascha; Hafner, Christian; Hengsberger, Matthias; Kim, Dong Eon; Kling, Matthias F.; Landsman, Alexandra; Gallmann, Lukas; Osterwalder, Jürg

    2016-01-01

    Illuminating a nano-sized metallic tip with ultrashort laser pulses leads to the emission of electrons due to multiphoton excitations. As optical fields become stronger, tunnelling emission directly from the Fermi level becomes prevalent. This can generate coherent electron waves in vacuum leading to a variety of attosecond phenomena. Working at high emission currents where multi-electron effects are significant, we were able to characterize the transition from one regime to the other. Specifically, we found that the onset of laser-driven tunnelling emission is heralded by the appearance of a peculiar delayed emission channel. In this channel, the electrons emitted via laser-driven tunnelling emission are driven back into the metal, and some of the electrons reappear in the vacuum with some delay time after undergoing inelastic scattering and cascading processes inside the metal. Our understanding of these processes gives insights on attosecond tunnelling emission from solids and should prove useful in designing new types of pulsed electron sources. PMID:27786287

  14. Photochemistry of Fe(Iii)-Carboxylates in Polysaccharide-Based Materials with Tunable Mechanical Properties

    Science.gov (United States)

    Giammanco, Giuseppe E.

    We present the formulation and study of light-responsive materials based on carboxylate-containing polysaccharides. The functional groups in these natural polymers allow for strong interactions with transition metal ions such as Fe(III). The known photochemistry of hydroxycarboxylic acids in natural waters inspired us in exploring the visible light induced photochemistry of the carboxylates in these polysaccharides when coordinated to Fe(III) ions. Described in this dissertation are the design and characterization of the Fe(III)-polysaccharide materials, specifically the mechanistic aspects of the photochemistry and the effects that these reactions have on the structure of the polymer materials. We present a study of the quantitative photochemistry of different polysaccharide systems, where the presence of uronic acids was important for the photoreaction to take place. Alginate (Alg), pectate (Pec), hyaluronic acid (Hya), xanthan gum (Xan), and a polysaccharide extracted from the Noni fruit (NoniPs), were among the natural uronic acid-containing polysaccharide (UCPS) systems we analyzed. Potato starch, lacking of uronate groups, did not present any photochemistry in the presence of Fe(III); however, we were able to induce a photochemical response in this polysaccharide upon chemical manipulation of its functional groups. Important structure-function relationships were drawn from this study. The uronate moiety present in these polysaccharides is then envisioned as a tool to induce response to light in a variety of materials. Following this approach, we report the formulation of materials for controlled drug release, able to encapsulate and release different drug models only upon illumination with visible light. Furthermore, hybrid hydrogels were prepared from UPCS and non-responsive polymers. Different properties of these materials could be tuned by controlling the irradiation time, intensity and location. These hybrid gels were evaluated as scaffolds for tissue

  15. Chloroplast Movement May Impact Plant Phenotyping and Photochemistry Results

    Science.gov (United States)

    Malas, J.; Pleban, J. R.; Wang, D. R.; Riley, C.; Mackay, D. S.

    2017-12-01

    Investigating phenotypic responses of crop species across environmental conditions is vital to improving agricultural productivity. Crop production is closely linked with photosynthetic activity, which can be evaluated using parameters such as relative chlorophyll, SPAD, and variable chlorophyll fluorescence. Recently, a handheld device known as the MultispeQ emerged on the market as an open-source instrument that aims to provide high-output, high-quality field data at a low cost to the plant research community. MultispeQ takes measurements of both environmental conditions (light intensity, temperature, humidity, etc.) and photosynthetic parameters (relative chlorophyll, SPAD, photosystem II quantum efficiency (FII), and non-photochemical quenching (NPQ)). Data are automatically backed up and shared on the PhotosynQ network, which serves as a collaborative platform for researchers and professionals. Here, we used the instrument to quantify photosynthetic time-courses of two Brassica rapa genotypes in response to two contrasting nutrient management strategies (Control; High Nitrogen). Previous research found that chloroplast movement is one strategy plants use to optimize photosynthesis across varying light conditions. We were able to detect chloroplast movement throughout the day using the MultispeQ device. Our results support the idea that chloroplast movement serves both as an intrinsic feature of the circadian clock and as a light avoidance strategy. Under low light conditions (PAR 0-300) more light at the near-infrared and red regions was absorbed than under higher light conditions (PAR 500-800). In one genotype by treatment combination, absorbance at 730nm was around 60% at low light, versus only 30% at high light conditions. In light of our results that relative chlorophyll may change throughout a day, we suggest that it is important to take note of these effects when collecting photosynthesis efficiency data in order to avoid bias in measurements. We also

  16. Effects of climate change on surface-water photochemistry: a review.

    Science.gov (United States)

    De Laurentiis, Elisa; Minella, Marco; Maurino, Valter; Minero, Claudio; Vione, Davide

    2014-10-01

    Information concerning the link between surface-water photochemistry and climate is presently very scarce as only a few studies have been dedicated to the subject. On the basis of the limited knowledge that is currently available, the present inferences can be made as follows: (1) Warming can cause enhanced leaching of ionic solutes from the catchments to surface waters, including cations and more biologically labile anions such as sulphate. Preferential sulphate biodegradation followed by removal as organic sulphides in sediment could increase alkalinity, favouring the generation of the carbonate radical, CO3 (·-). However, this phenomenon would be easily offset by fluctuations of the dissolved organic carbon (DOC), which is strongly anticorrelated with CO3 (·-). Therefore, obtaining insight into DOC evolution is a key issue in understanding the link between photochemistry and climate. (2) Climate change could exacerbate water scarcity in the dry season in some regions. Fluctuations in the water column could deeply alter photochemistry that is usually favoured in shallower waters. However, the way water is lost would strongly affect the prevailing photoinduced processes. Water outflow without important changes in solute concentration would mostly favour reactions induced by the hydroxyl and carbonate radicals (·OH and CO3 (·-)). In contrast, evaporative concentration would enhance reactions mediated by singlet oxygen ((1)O2) and by the triplet states of chromophoric dissolved organic matter ((3)CDOM*). (3) In a warmer climate, the summer stratification period of lakes would last longer, thereby enhancing photochemical reactions in the epilimnion but at the same time keeping the hypolimnion water in the dark for longer periods.

  17. Evaluation of linear ozone photochemistry parametrizations in a stratosphere-troposphere data assimilation system

    Directory of Open Access Journals (Sweden)

    A. J. Geer

    2007-01-01

    Full Text Available This paper evaluates the performance of various linear ozone photochemistry parametrizations using the stratosphere-troposphere data assimilation system of the Met Office. A set of experiments were run for the period 23 September 2003 to 5 November 2003 using the Cariolle (v1.0 and v2.1, LINOZ and Chem2D-OPP (v0.1 and v2.1 parametrizations. All operational meteorological observations were assimilated, together with ozone retrievals from the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS. Experiments were validated against independent data from the Halogen Occultation Experiment (HALOE and ozonesondes. Additionally, a simple offline method for comparing the parametrizations is introduced. It is shown that in the upper stratosphere and mesosphere, outside the polar night, ozone analyses are controlled by the photochemistry parametrizations and not by the assimilated observations. The most important factor in getting good results at these levels is to pay attention to the ozone and temperature climatologies in the parametrizations. There should be no discrepancies between the climatologies and the assimilated observations or the model, but there is also a competing demand that the climatologies be objectively accurate in themselves. Conversely, in the lower stratosphere outside regions of heterogeneous ozone depletion, the ozone analyses are dominated by observational increments and the photochemistry parametrizations have little influence. We investigate a number of known problems in LINOZ and Cariolle v1.0 in more detail than previously, and we find discrepancies in Cariolle v2.1 and Chem2D-OPP v2.1, which are demonstrated to have been removed in the latest available versions (v2.8 and v2.6 respectively. In general, however, all the parametrizations work well through much of the stratosphere, helped by the presence of good quality assimilated MIPAS observations.

  18. Photochemistry of pyrene with water at low temperature: study of atmospherical and astrochemical interest.

    Science.gov (United States)

    Guennoun, Zohra; Aupetit, Christian; Mascetti, Joëlle

    2011-03-17

    Photochemistry of a polyaromatic hydrocarbon, pyrene C(16)H(10), with water has been investigated at cryogenic temperatures. Photoprocessing of this species, performed at λ > 235 nm, in argon matrices, adsorbed onto amorphous water surfaces, and trapped in solid water, led to the formation of ketonic isomers, C(16)H(10)O, and possibly quinones. These species have been identified for the first time by infrared spectroscopy with the support of isotopic substitution experiments and DFT calculations. These oxidized pyrene-like species, of atmospherical and astrochemical interest, most likely arise from a tautomeric rearrangement of their analogous hydroxylated molecules, these latter being formed by reaction of water with pyrene cations.

  19. On the relationship between the greenhouse effect, atmospheric photochemistry, and species distribution

    Science.gov (United States)

    Callis, L. B.; Boughner, R. E.; Natarajan, M.

    1983-01-01

    The coupling that exists between infrared opacity changes and tropospheric (and to a lesser extent stratospheric) chemistry is explored in considerable detail, and the effects arising from various perturbations are examined. The studies are carried out with a fully coupled one-dimensional radiative-convective-photochemical model (RCP) that extends from the surface to 53.5 km and has the capability of calculating surface temperature changes due to both chemical and radiative perturbations. The model encompasses contemporary atmospheric chemistry and photochemistry involving the O(x), HO(x), NO(x), and Cl(x) species.

  20. Reactivity of biogenic manganese oxide for metal sequestration and photochemistry: Computational solid state physics study

    Energy Technology Data Exchange (ETDEWEB)

    Kwon, K.D.; Sposito, G.

    2010-02-01

    Many microbes, including both bacteria and fungi, produce manganese (Mn) oxides by oxidizing soluble Mn(II) to form insoluble Mn(IV) oxide minerals, a kinetically much faster process than abiotic oxidation. These biogenic Mn oxides drive the Mn cycle, coupling it with diverse biogeochemical cycles and determining the bioavailability of environmental contaminants, mainly through strong adsorption and redox reactions. This mini review introduces recent findings based on quantum mechanical density functional theory that reveal the detailed mechanisms of toxic metal adsorption at Mn oxide surfaces and the remarkable role of Mn vacancies in the photochemistry of these minerals.

  1. Photochemistry of methane and the formation of hydrocyanic acid (HCN) in the earth's early atmosphere

    Science.gov (United States)

    Zahnle, K. J.

    1986-01-01

    A one-dimensional photochemical model is used to analyze the photochemistries of CH4 and HCN in the primitive terrestrial atmosphere. CH4, N2, and HCN photolysis are examined. The background atmosphere and boundary conditions applied in the analysis are described. The formation of HCN as a by-product of N2 and CH4 photolysis is investigated; the effects of photodissociation and rainfall on HCN is discussed. The low and high CH4 mixing ratios and radical densities are studied.

  2. HIGH-TEMPERATURE PHOTOCHEMISTRY IN THE ATMOSPHERE OF HD 189733b

    International Nuclear Information System (INIS)

    Line, M. R.; Yung, Y. L.; Liang, M. C.

    2010-01-01

    Recent infrared spectroscopy of hot exoplanets is beginning to reveal their atmospheric composition. Deep within the planetary atmosphere, the composition is controlled by thermochemical equilibrium. Photochemistry becomes important higher in the atmosphere, at levels above ∼1 bar. These two chemistries compete between ∼1 and 10 bars in hot-Jupiter-like atmospheres, depending on the strength of the eddy mixing and temperature. HD 189733b provides an excellent laboratory in which to study the consequences of chemistry of hot atmospheres. The recent spectra of HD 189733b contain signatures of CH 4 , CO 2 , CO, and H 2 O. Here we identify the primary chemical pathways that govern the abundances of CH 4 , CO 2 , CO, and H 2 O in the cases of thermochemical equilibrium chemistry, photochemistry, and their combination. Our results suggest that the disequilibrium mechanisms can significantly enhance the abundances of these species above their thermochemical equilibrium value, so some caution must be taken when assuming that an atmosphere is in strict thermochemical equilibrium.

  3. General patterns in the photochemistry of pregna-1,4-dien-3,20-diones.

    Science.gov (United States)

    Ricci, Andrea; Fasani, Elisa; Mella, Mariella; Albini, Angelo

    2003-05-30

    The photochemistry of six pregna-1,4-dien-3,20-diones has been compared and found to involve both the cyclohexadienone moiety in ring A and the isolated ketone at C-20. The two reactions take place proportionally to the fraction of light absorbed by each chromophore. The cross-conjugated ketone absorbs predominantly or exclusively at both 254 and 366 nm and undergoes the "lumi" rearrangement to bicyclo[3.1.0]hex-3-en-2-one. The quantum yield of the reaction diminished somewhat with increasing lambda(exc), e.g., for prednisolone Phi(254) (nm) = 0.42, Phi(366) (nm) = 0.3. A much stronger lowering is caused by halogen substitution in position 9 (by a factor of 3 for F, >50 for Cl), apparently due to a shortened triplet lifetime caused by heavy atom effect. At 310 nm, both chromophores absorb to a comparable degree and both may react. The reaction at C(20) ketone involves either quite efficient alpha-cleavage (C(17)-C(20)) for compounds bearing an acetal or hydroxyl function at C(17) or less effective (by a factor of ca. 10) hydrogen abstraction from the 18-methyl group in the other cases (finally resulting in Norrish II fragmentation or Yang cyclization). The results allow generalizing how the substitution pattern surrounding each chromophore affects the photoreactivity at that site and the competition between the two modes, allowing predicting the photochemistry of this family of antiinflammatory drugs.

  4. Modeling of synchrotron-based laboratory simulations of Titan's ionospheric photochemistry

    Science.gov (United States)

    Carrasco, Nathalie; Peng, Zhe; Pernot, Pascal

    2014-11-01

    The APSIS reactor has been designed to simulate in the laboratory with a VUV synchrotron irradiation the photochemistry occurring in planetary upper atmospheres. A N2-CH4 Titan-like gas mixture has been studied, whose photochemistry in Titan's ionospheric irradiation conditions leads to a coupled chemical network involving both radicals and ions. In the present work, an ion-neutral coupled model is developed to interpret the experimental data, taking into account the uncertainties on the kinetic parameters by Monte Carlo sampling. The model predicts species concentrations in agreement with mass spectrometry measurements of the methane consumption and product blocks intensities. Ion chemistry and in particular dissociative recombination are found to be very important through sensitivity analysis. The model is also applied to complementary environmental conditions, corresponding to Titan's ionospheric average conditions and to another existing synchrotron setup. An innovative study of the correlations between species concentrations identifies two main competitive families, leading respectively to saturated and unsaturated species. We find that the unsaturated growth family, driven by C2H2 , is dominant in Titan's upper atmosphere, as observed by the Cassini INMS. But the saturated species are substantially more intense in the measurements of the two synchrotron experimental setups, and likely originate from catalysis by metallic walls of the reactors.

  5. VUV spectroscopy and photochemistry of five interstellar and putative prebiotic molecules

    Science.gov (United States)

    Schwell, M.; Gaie-Levrel, F.; Bénilan, Y.; Gazeau, M.-C.; Fray, N.; Saul, G.; Champion, N.; Leach, S.; Guillemin, J.-C.

    2012-02-01

    For many years, our group has been investigating the VUV spectroscopy and photochemistry of molecules of astrophysical (Jochims et al. 2006a,b; Leach et al. 2008; Schwell et al. 2012) and prebiotic interest (Schwell et al. 2006). Polyynes and cyano-polyynes that are abundant in the interstellar medium (ISM) and in planetary atmospheres, have been investigated too (e.g. Fray et al. 2010). An aerosol source for reactive and thermo-labile compounds has been developed (Gaie-Levrel et al. 2011) to perform gas-phase measurements. These are necessary to measure intrinsic molecular properties and to compare to quantum chemical calculations. Besides measuring absolute absorption and photoionization cross sections, dissociative channels and their involved excited states are identified for a number of molecules of interstellar interest. Branching ratios of the respective elementary photoreactions are determined in order to understand and model the photochemistry occurring in the ISM. Some very recent results on the dissociative photoionization of methylformate (MF), glycolaldehyde (GA), dimethylether (DIM), aminoacetonitrile (AAC) and cyanoacetylene (CA), are presented here.

  6. Toward autonomous measurements of photosynthetic electron transport rates: An evaluation of active fluorescence-based measurements of photochemistry

    NARCIS (Netherlands)

    Silsbe, G.M.; Oxborough, K.; Suggett, D.J.; Forster, R.M.; Ihnken, S.; Komárek, O.; Lawrenz, E.; Prášil, O.; Röttgers, R.; Šicner, M.; Simis, S.G.H.; Van Dijk, M.A.; Kromkamp, J.C.

    2015-01-01

    This study presents a methods evaluation and intercalibration of active fluorescence-based measurements of the quantum yield ( inline image) and absorption coefficient ( inline image) of photosystem II (PSII) photochemistry. Measurements of inline image, inline image, and irradiance (E) can be

  7. The Electrodeless Discharge Lamp: a Prospective Tool for Photochemistry - Part 4. Temperature- and Envelope Material-Dependent Emission Characteristics

    Czech Academy of Sciences Publication Activity Database

    Müller, P.; Klán, P.; Církva, Vladimír

    2003-01-01

    Roč. 158, č. 1 (2003), s. 1-5 ISSN 1010-6030 R&D Projects: GA ČR GA203/02/0879 Institutional research plan: CEZ:AV0Z4072921 Keywords : photochemistry * microwave * electrodeless discharge lamp Subject RIV: CC - Organic Chemistry Impact factor: 1.693, year: 2003

  8. The Elecrodeless Discharge Lamp: A Prospective Tool for Photochemistry Part 5. Fill Material-Dependent Emission Characteristics

    Czech Academy of Sciences Publication Activity Database

    Müller, P.; Klán, P.; Církva, Vladimír

    2005-01-01

    Roč. 171, Vol.1 (2005), s. 51-57 ISSN 1010-6030 R&D Projects: GA ČR GA203/02/0879 Institutional research plan: CEZ:AV0Z4072921 Keywords : photochemistry * microwave * spectra Subject RIV: CC - Organic Chemistry Impact factor: 2.286, year: 2005

  9. Laser Photochemistry.

    Science.gov (United States)

    1981-07-01

    inverted by the first, i.e., at the moment of time t = T, such that i = (2n+)lT, where 0 is the Rabi frequency (Oraevski et al., 1976). . classical... anisotropic molecule present. CW HeNe, Ar+ and Kr+ lasers are used, and the filter method is necessary because of time-scales lo8 - 10ll Hz. Some general...e.g., truncated harmonic oscillator, square well, spherically symmetric Morse or Lennard-Jones, anisotropic (angle-dependent) Morse or Lennard-Jones

  10. EUV-VUV photochemistry in the upper atmospheres of Titan and the early Earth

    Science.gov (United States)

    Imanaka, H.; Smith, M. A.

    2010-12-01

    Titan, the organic-rich moon of Saturn, possesses a thick atmosphere of nitrogen, globally covered with organic haze layers. The recent Cassini’s INMS and CAPS observations clearly demonstrate the importance of complex organic chemistry in the ionosphere. EUV photon radiation is the major driving energy source there. Our previous laboratory study of the EUV-VUV photolysis of N2/CH4 gas mixtures demonstrates a unique role of nitrogen photoionization in the catalytic formation of complex hydrocarbons in Titan’s upper atmosphere (Imanaka and Smith, 2007, 2009). Such EUV photochemistry could also have played important roles in the formation of complex organic molecules in the ionosphere of the early Earth. It has been suggested that the early Earth atmosphere may have contained significant amount of reduced species (CH4, H2, and CO) (Kasting, 1990, Pavlov et al., 2001, Tian et al., 2005). Recent experimental study, using photon radiation at wavelengths longer than 110 nm, demonstrates that photochemical organic haze could have been generated from N2/CO2 atmospheres with trace amounts of CH4 or H2 (Trainer et al., 2006, Dewitt et al., 2009). However, possible EUV photochemical processes in the ionosphere are not well understood. We have investigated the effect of CO2 in the possible EUV photochemical processes in simulated reduced early Earth atmospheres. The EUV-VUV photochemistry using wavelength-tunable synchrotron light between 50 - 150 nm was investigated for gas mixtures of 13CO2/CH4 (= 96.7/3.3) and N2/13CO2/CH4 (= 90/6.7/3.3). The onsets of unsaturated hydrocarbon formation were observed at wavelengths shorter than the ionization potentials of CO2 and N2, respectively. This correlation indicates that CO2 can play a similar catalytic role to N2 in the formation of heavy organic species, which implies that EUV photochemistry might have significant impact on the photochemical generation of organic haze layers in the upper atmosphere of the early Earth.

  11. Photochemistry of fluorinated 4-iodophenylnitrenes: matrix isolation and spectroscopic characterization of phenylnitrene-4-yls.

    Science.gov (United States)

    Grote, Dirk; Sander, Wolfram

    2009-10-02

    The photochemistry of a series of fluorinated p-iodophenyl azides 2 has been investigated using matrix isolation IR and EPR spectroscopy. In all cases, the corresponding phenylnitrenes 1 were formed as primary photoproducts. Further irradiation of the nitrenes 1 resulted in the formation of azirines 3, ketenimines 4, and nitreno radicals 5. The yield of 5 depends on the number of ortho fluorine substituents: with two ortho fluorine atoms the highest yield is observed, whereas without fluorine atoms the yield is too low for IR spectroscopic detection. The interconversion between the isomers 1, 3, and 4 proved to be rather complex. If the fluorine atoms are distributed unsymmetrically, two isomers of azirines 3 and ketenimines 4 can be formed. The yields of these isomers depend critically on the irradiation conditions.

  12. New concepts in therapeutic photomedicine: photochemistry, optical targeting and the therapeutic window

    International Nuclear Information System (INIS)

    Parrish, J.A.

    1981-01-01

    Advances in optics technology, synthetic photochemistry, and the science of photobiology make it possible to think beyond phototherapy and photochemotherapy which is dependent on direct photochemical alteration of metabolites or direct phototoxic insult to cells. This report discusses another gender of photomedicine therapy which includes in vivo photoactivation of medicines, photon-dependent drug delivery, and manipulation of host and exposure source to maximize therapeutic index. These therapeutic manipulations are made possible because the skin is highly overperfused and because non-ionizing electromagnetic radiation that enters skin and blood has adequate photon energy to cause electronic excitation. Radiation of 320-800 nm is not very directly phototoxic, is absorbed by a variety of relatively nontoxic photolabile molecules and has an internal dosimetric depth profile. This radiation can therefore be used to activate, deactivate, bind, release or biotransform medications in vivo in skin or other organs. The photochemist, synthetic chemist and photobiologist can collaborate to significantly increase therapeutic possibilities

  13. Combined In Situ Illumination-NMR-UV/Vis Spectroscopy: A New Mechanistic Tool in Photochemistry.

    Science.gov (United States)

    Seegerer, Andreas; Nitschke, Philipp; Gschwind, Ruth M

    2018-06-18

    Synthetic applications in photochemistry are booming. Despite great progress in the development of new reactions, mechanistic investigations are still challenging. Therefore, we present a fully automated in situ combination of NMR spectroscopy, UV/Vis spectroscopy, and illumination to allow simultaneous and time-resolved detection of paramagnetic and diamagnetic species. This optical fiber-based setup enables the first acquisition of combined UV/Vis and NMR spectra in photocatalysis, as demonstrated on a conPET process. Furthermore, the broad applicability of combined UVNMR spectroscopy for light-induced processes is demonstrated on a structural and quantitative analysis of a photoswitch, including rate modulation and stabilization of transient species by temperature variation. Owing to the flexibility regarding the NMR hardware, temperature, and light sources, we expect wide-ranging applications of this setup in various research fields. © 2018 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA.

  14. Photochemistry of the α-Al2O3-PETN Interface

    Directory of Open Access Journals (Sweden)

    Roman V. Tsyshevsky

    2016-02-01

    Full Text Available Optical absorption measurements are combined with electronic structure calculations to explore photochemistry of an α-Al2O3-PETN interface formed by a nitroester (pentaerythritol tetranitrate, PETN, C5H8N4O12 and a wide band gap aluminum oxide (α-Al2O3 substrate. The first principles modeling is used to deconstruct and interpret the α-Al2O3-PETN absorption spectrum that has distinct peaks attributed to surface F0-centers and surface—PETN transitions. We predict the low energy α-Al2O3 F0-center—PETN transition, producing the excited triplet state, and α-Al2O3 F0-center—PETN charge transfer, generating the PETN anion radical. This implies that irradiation by commonly used lasers can easily initiate photodecomposition of both excited and charged PETN at the interface. The feasible mechanism of the photodecomposition is proposed.

  15. Bond selective photochemistry in CH2BrI through electronic excitation at 210 nm

    International Nuclear Information System (INIS)

    Butler, L.J.; Hintsa, E.J.; Lee, Y.T.

    1986-01-01

    To explore the possibility of bond selective photochemistry in an excited electronic state, we have studied the photolysis of CH 2 BrI in a molecular beam at 210 nm. Following the direct local excitation of a repulsive transition on the C--Br bond at 210 nm, the fragments were detected by time-of-flight mass spectrometry. The dominant channel was found to be C--Br fission (60%) releasing an average of 15 kcal/mol into translation with the remainder reacting to form CH 2 +IBr and CH 2 +I+Br. There was no evidence for the primary fission of the C--I bond, making this the first clear example of the selective cleavage of a stronger bond in a molecule over the weakest one

  16. Photochemistry at high temperatures - potential of ZnO as a high temperature photocatalyst

    Energy Technology Data Exchange (ETDEWEB)

    Schubnell, M; Beaud, P; Kamber, I [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1997-06-01

    Direct conversion of solar radiation into useful, storeable and transportable chemical products is the primary goal of solar chemistry. In this paper we discuss some fundamental aspects of photochemistry at elevated temperatures. We show that luminescence can serve as an indicator of the potential use of a system as a photoconverter. As an example we present experimental data on the chemical potential and on the lifetime of the excited states of ZnO. The low luminescence quantum yield together with a lifetime of about 200 ps indicate that an efficient photochemical conversion on ZnO is highly improbable. We believe this to be a general feature of chemical systems based on a semiconductor photocatalyst, in particular of photoreactions at a solid/gas interface. (author) 3 figs., 6 refs

  17. Modification of porous silicon rugate filters through thiol-yne photochemistry

    International Nuclear Information System (INIS)

    Soeriyadi, Alexander H.; Zhu, Ying; Gooding, J. Justin; Reece, Peter

    2014-01-01

    Porous silicon (PSi) has a considerable potential as biosensor platform. In particular, the ability to modify the surface chemistry of porous silicon is of interest. Here we present a generic method to modify the surface of porous silicon through thiol-yne photochemistry initiated by a radical initiator. Firstly, a freshly etched porous silicon substrate is modified through thermal hydrosilylation with 1,8-nonadiyne to passivate the surface and introduce alkyne functionalities. The alkyne functional surface could then be further reacted with thiol species in the presence of a radical initiator and UV light. Functionalization of the PSi rugate filter is followed with optical reflectivity measurements as well as high resolution X-ray photoelectron spectroscopy (XPS)

  18. Automatic generation of active coordinates for quantum dynamics calculations: Application to the dynamics of benzene photochemistry

    International Nuclear Information System (INIS)

    Lasorne, Benjamin; Sicilia, Fabrizio; Bearpark, Michael J.; Robb, Michael A.; Worth, Graham A.; Blancafort, Lluis

    2008-01-01

    A new practical method to generate a subspace of active coordinates for quantum dynamics calculations is presented. These reduced coordinates are obtained as the normal modes of an analytical quadratic representation of the energy difference between excited and ground states within the complete active space self-consistent field method. At the Franck-Condon point, the largest negative eigenvalues of this Hessian correspond to the photoactive modes: those that reduce the energy difference and lead to the conical intersection; eigenvalues close to 0 correspond to bath modes, while modes with large positive eigenvalues are photoinactive vibrations, which increase the energy difference. The efficacy of quantum dynamics run in the subspace of the photoactive modes is illustrated with the photochemistry of benzene, where theoretical simulations are designed to assist optimal control experiments

  19. Mechanistic reappraisal of early stage photochemistry in the light-driven enzyme protochlorophyllide oxidoreductase.

    Directory of Open Access Journals (Sweden)

    Derren J Heyes

    Full Text Available The light-driven enzyme protochlorophyllide oxidoreductase (POR catalyzes the reduction of protochlorophyllide (Pchlide to chlorophyllide (Chlide. This reaction is a key step in the biosynthesis of chlorophyll. Ultrafast photochemical processes within the Pchlide molecule are required for catalysis and previous studies have suggested that a short-lived excited-state species, known as I675*, is the first catalytic intermediate in the reaction and is essential for capturing excitation energy to drive subsequent hydride and proton transfers. The chemical nature of the I675* excited state species and its role in catalysis are not known. Here, we report time-resolved pump-probe spectroscopy measurements to study the involvement of the I675* intermediate in POR photochemistry. We show that I675* is not unique to the POR-catalyzed photoreduction of Pchlide as it is also formed in the absence of the POR enzyme. The I675* species is only produced in samples that contain both Pchlide substrate and Chlide product and its formation is dependent on the pump excitation wavelength. The rate of formation and the quantum yield is maximized in 50∶50 mixtures of the two pigments (Pchlide and Chlide and is caused by direct energy transfer between Pchlide and neighboring Chlide molecules, which is inhibited in the polar solvent methanol. Consequently, we have re-evaluated the mechanism for early stage photochemistry in the light-driven reduction of Pchlide and propose that I675* represents an excited state species formed in Pchlide-Chlide dimers, possibly an excimer. Contrary to previous reports, we conclude that this excited state species has no direct mechanistic relevance to the POR-catalyzed reduction of Pchlide.

  20. Proceedings of the twenty-first DOE solar photochemistry research conference

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-06-01

    The Solar Photochemistry Research Conference brings together grantees and contractors of the Division of Chemical Sciences who are engaged in fundamental research on solar photochemical energy conversion. The annual conference provides a focus for the program by allowing for the exchange of new information and ideas, identification of needs and opportunities, and fostering of collaborations among investigators of disparate chemistry backgrounds. The synergy that has been achieved is a major strength of the program. The research provides the foundations for future solar technologies, in which light-induced charge separation processes will be applied to conversion of light energy to chemical energy, e.g., production of alcohols from carbon dioxide, hydrogen from water, ammonia from atmospheric nitrogen, or other needed chemicals at lower cost of by using sunlight as the energy source. The program includes topical sessions on semiconductor nanoparticles, nanocrystalline films, and photoinduced charge separation at the semiconductor/liquid interface; photochemistry and photophysics of transition metal complexes; photoinduced charge separation in zeolites and lamellar assemblies; intramolecular charge separation and electron transfer; dynamics of solvation and solution interfaces; and photoconversion via porphyrins and biomimetic constructs. The special guest plenary lecturer is Professor Moungi Bawendi of the Massachusetts Institute of Technology, who spoke on semiconductor nanocrystallites (quantum dots). As an added feature, Tom Surek, the Photovoltaics Technology program manager at NREL, presented a status report on one of the most promising and heavily supported programs in solar energy conversion technology, solid state photovoltaics. This volume contains the agenda for the meeting, abstracts of the 31 formal presentations and 55 posters, as well as an address list for the 111 participants.

  1. Atmospheric photochemistry at a fatty acid coated air/water interface

    Science.gov (United States)

    George, Christian; Rossignol, Stéphanie; Passananti, Monica; Tinel, Liselotte; Perrier, Sebastien; Kong, Lingdong; Brigante, Marcello; Bianco, Angelica; Chen, Jianmin; Donaldson, James

    2017-04-01

    Over the past 20 years, interfacial processes have become increasingly of interest in the field of atmospheric chemistry, with many studies showing that environmental surfaces display specific chemistry and photochemistry, enhancing certain reactions and acting as reactive sinks or sources for various atmospherically relevant species. Many molecules display a free energy minimum at the air-water interface, making it a favored venue for compound accumulation and reaction. Indeed, surface active molecules have been shown to undergo specific photochemistry at the air-water interface. This presentation will address some recent surprises. Indeed, while fatty acids are believed to be photochemically inert in the actinic region, complex volatile organic compounds (VOCs) are produced during illumination of an air-water interface coated solely with a monolayer of carboxylic acid. When aqueous solutions containing nonanoic acid (NA) at bulk concentrations that give rise to just over monolayer NA coverage are illuminated with actinic radiation, saturated and unsaturated aldehydes are seen in the gas phase and more highly oxygenated products appear in the aqueous phase. This chemistry is probably initiated by triplet state NA molecules excited by direct absorption of actinic light at the water surface. As fatty acids covered interfaces are ubiquitous in the environment, such photochemical processing will have a significant impact on local ozone and particle formation. In addition, it was shown recently that a heterogeneous reaction between SO2 and oleic acid (OA; an unsaturated fatty acid) takes place and leads efficiently to the formation of organosulfur products. Here, we demonstrate that this reaction proceeds photochemically on various unsaturated fatty acids compounds, and may therefore have a general environmental impact. This is probably due to the chromophoric nature of the SO2 adduct with C=C bonds, and means that the contribution of this direct addition of SO2 could

  2. Solid-State Photochemistry as a Formation Mechanism for Titan's Stratospheric C4N2 Ice Clouds

    Science.gov (United States)

    Anderson, C. M.; Samuelson, R. E.; Yung, Y. L.; McLain, J. L.

    2016-01-01

    We propose that C4N2 ice clouds observed in Titan's springtime polar stratosphere arise due to solid-state photochemistry occurring within extant ice cloud particles of HCN-HC3N mixtures. This formation process resembles the halogen-induced ice particle surface chemistry that leads to condensed nitric acid trihydrate (NAT) particles and ozone depletion in Earth's polar stratosphere. As our analysis of the Cassini Composite Infrared Spectrometer 478 per centimeter ice emission feature demonstrates, this solid-state photochemistry mechanism eliminates the need for the relatively high C4N2 saturation vapor pressures required (even though they are not observed) when the ice is produced through the usual procedure of direct condensation from the vapor.

  3. Lifetimes of organic photovoltaics: photochemistry, atmosphere effects and barrier layers in ITO-MEHPPV:PCBM-aluminium devices

    DEFF Research Database (Denmark)

    Krebs, Frederik C; Carlé, Jon Eggert; Cruys-Bagger, N.

    2005-01-01

    Large area polymer photovoltaic cells based on poly[(2-methoxy-5-ethylhexyloxy)-1, 4-phenylenevinylene] (MEH-PPV) and [6,6]-phenyl-C-61-butyric acid methyl ester (PCBM) were prepared. The lifetimes of the photovoltaic cells were studied in terms of the atmosphere, handling, electrode treatment, m...

  4. Photochemistry and Gas-Phase FTIR Spectroscopy of Formic Acid Interaction with Anatase Ti18O2 Nanoparticles

    Czech Academy of Sciences Publication Activity Database

    Civiš, Svatopluk; Ferus, Martin; Zukalová, Markéta; Kubát, Pavel; Kavan, Ladislav

    2012-01-01

    Roč. 116, č. 20 (2012), s. 11200-11205 ISSN 1932-7447 R&D Projects: GA AV ČR IAAX00100903; GA AV ČR IAA400400804; GA AV ČR KAN200100801; GA ČR GAP208/10/1678; GA MŠk OC09044 Institutional support: RVO:61388955 Keywords : photochemistry * FTIR spectroscopy * nanoparticles Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 4.814, year: 2012

  5. Triplet state photochemistry and the three-state crossing of acetophenone within time-dependent density-functional theory

    Energy Technology Data Exchange (ETDEWEB)

    Huix-Rotllant, Miquel, E-mail: miquel.huix@gmail.com; Ferré, Nicolas, E-mail: nicolas.ferre@univ-amu.fr [Institut de Chimie Radicalaire (UMR-7273), Aix-Marseille Université, CNRS, 13397 Marseille Cedex 20 (France)

    2014-04-07

    Even though time-dependent density-functional theory (TDDFT) works generally well for describing excited states energies and properties in the Franck-Condon region, it can dramatically fail in predicting photochemistry, notably when electronic state crossings occur. Here, we assess the ability of TDDFT to describe the photochemistry of an important class of triplet sensitizers, namely, aromatic ketones. We take acetophenone as a test molecule, for which accurate ab initio results exist in the literature. Triplet acetophenone is generated thanks to an exotic three-state crossing involving one singlet and two triplets states (i.e., a simultaneous intersystem crossing and triplet conical intersection), thus being a stringent test for approximate TDDFT. We show that most exchange-correlation functionals can only give a semi-qualitative picture of the overall photochemistry, in which the three-state crossing is rather represented as a triplet conical intersection separated from the intersystem crossing. The best result overall is given by the double hybrid functional mPW2PLYP, which is even able to reproduce quantitatively the three-state crossing region. We rationalize this results by noting that double hybrid functionals include a larger portion of double excitation character to the excited states.

  6. Biweekly list of papers on radiation chemistry and photochemistry. Annual cumulation with keyword and author indexes. Volume 16. 1983

    International Nuclear Information System (INIS)

    Carmichael, I.C.; Helman, W.P.; Hug, G.L.; Ross, A.B.

    1983-01-01

    The Biweekly List of Papers on Radiation Chemistry and Photochemistry is a current-awareness service published by the Radiation Chemistry Data Center (RCDC), with special emphasis on the kinetics and other properties of transient ions, radicals, and excited species. Papers are included on the radiation chemistry and photochemistry of organic and inorganic systems, biological molecules and polymers, with references to ESR and luminescence studies. Complete coverage is attempted only for those studies which are initiated by light or ionizing radiation, and which provide quantitative physical chemical data such as quantum yields, specific rates, G values, etc. No attempt is made to cover topics such as mechanistic and preparative photochemistry, photosynthesis, photography, and irradiation of metals. The references listed herein are obtained from scanning about 60 current journals as well as Chemical Abstracts, INIS Atomindex and several other publications listing current references. The reference lists, which are issued biweekly, are cumulated annually with the addition of keyword and author indexes. Indexed cumulations were published semiannually for Vol. 4-6 (1971-73) and are published annually for Vol. 7+ (1974+); back copies are available from the National Technical Information Service (NTIS)

  7. Using the Flipchem Photochemistry Model When Fitting Incoherent Scatter Radar Data

    Science.gov (United States)

    Reimer, A. S.; Varney, R. H.

    2017-12-01

    The North face Resolute Bay Incoherent Scatter Radar (RISR-N) routinely images the dynamics of the polar ionosphere, providing measurements of the plasma density, electron temperature, ion temperature, and line of sight velocity with seconds to minutes time resolution. RISR-N does not directly measure ionospheric parameters, but backscattered signals, recording them as voltage samples. Using signal processing techniques, radar autocorrelation functions (ACF) are estimated from the voltage samples. A model of the signal ACF is then fitted to the ACF using non-linear least-squares techniques to obtain the best-fit ionospheric parameters. The signal model, and therefore the fitted parameters, depend on the ionospheric ion composition that is used [e.g. Zettergren et. al. (2010), Zou et. al. (2017)].The software used to process RISR-N ACF data includes the "flipchem" model, which is an ion photochemistry model developed by Richards [2011] that was adapted from the Field LineInterhemispheric Plasma (FLIP) model. Flipchem requires neutral densities, neutral temperatures, electron density, ion temperature, electron temperature, solar zenith angle, and F10.7 as inputs to compute ion densities, which are input to the signal model. A description of how the flipchem model is used in RISR-N fitting software will be presented. Additionally, a statistical comparison of the fitted electron density, ion temperature, electron temperature, and velocity obtained using a flipchem ionosphere, a pure O+ ionosphere, and a Chapman O+ ionosphere will be presented. The comparison covers nearly two years of RISR-N data (April 2015 - December 2016). Richards, P. G. (2011), Reexamination of ionospheric photochemistry, J. Geophys. Res., 116, A08307, doi:10.1029/2011JA016613.Zettergren, M., Semeter, J., Burnett, B., Oliver, W., Heinselman, C., Blelly, P.-L., and Diaz, M.: Dynamic variability in F-region ionospheric composition at auroral arc boundaries, Ann. Geophys., 28, 651-664, https

  8. High-Power 365 nm UV LED Mercury Arc Lamp Replacement for Photochemistry and Chemical Photolithography.

    Science.gov (United States)

    Hölz, K; Lietard, J; Somoza, M M

    2017-01-03

    Ultraviolet light emitting diodes (UV LEDs) have become widespread in chemical research as highly efficient light sources for photochemistry and photopolymerization. However, in more complex experimental setups requiring highly concentrated light and highly spatially resolved patterning of the light, high-pressure mercury arc lamps are still widely used because they emit intense UV light from a compact arc volume that can be efficiently coupled into optical systems. Advances in the deposition and p -type doping of gallium nitride have recently permitted the manufacture of UV LEDs capable of replacing mercury arc lamps also in these applications. These UV LEDs exceed the spectral radiance of mercury lamps even at the intense I-line at 365 nm. Here we present the successful exchange of a high-pressure mercury arc lamp for a new generation UV LED as a light source in photolithographic chemistry and its use in the fabrication of high-density DNA microarrays. We show that the improved light radiance and efficiency of these LEDs offer substantial practical, economic and ecological advantages, including faster synthesis, lower hardware costs, very long lifetime, an >85-fold reduction in electricity consumption and the elimination of mercury waste and contamination.

  9. Photochemistry of Coronene in Cosmic Water Ice Analogs at Different Concentrations

    Energy Technology Data Exchange (ETDEWEB)

    De Barros, A. L. F. [Departamento de Física, Centro Federal de Educação Tecnológica Celso Suckow da Fonseca, Av. Maracanã 229, 20271-110 Rio de Janeiro, RJ (Brazil); Mattioda, A. L.; Ricca, A.; Cruz-Diaz, G.A.; Allamandola, L. J. [NASA Ames Research Center, Mail Stop 245-6, Moffett Field, CA 94035-1000 (United States)

    2017-10-20

    This work presents the photochemistry of ultraviolet (UV) irradiated coronene in water ices at 15 K studied using mid-infrared Fourier transform (FTIR) spectroscopy for C{sub 24}H{sub 12}:H{sub 2}O at concentrations of (1:50), (1:150), (1:200), (1:300), and (1:400). Previous UV irradiation studies of anthracene:H{sub 2}O, pyrene:H{sub 2}O, and benzo[ghi]perylene:H{sub 2}O ices at 15 K have shown that aromatic alcohols and ketones, as well as CO{sub 2} and H{sub 2}CO, are formed at very low temperatures. Likewise, here, in addition to the coronene cation, hydroxy-, keto-, and protonated coronene (coronene H{sup +}) are formed. The rate constants for the decay of neutral coronene and for the formation of photoproducts have been derived. It is shown that Polycyclic Aromatic Hydrocarbons (PAHs) and their UV induced PAH:H{sub 2}O photoproducts have mid-infrared spectroscopic signatures in the 5–8 μ m region that can contribute to the interstellar ice components described by Boogert et al. as C1–C5. Our results suggest that oxygenated and hydrogenated PAHs could be in UV-irradiated regions of the interstellar medium where water-rich ices are important.

  10. The atmosphere simulation chamber SAPHIR: a tool for the investigation of photochemistry.

    Science.gov (United States)

    Brauers, T.; Bohn, B.; Johnen, F.-J.; Rohrer, R.; Rodriguez Bares, S.; Tillmann, R.; Wahner, A.

    2003-04-01

    On the campus of the Forschungszentrum Jülich we constructed SAPHIR (Simulation of Atmospheric PHotochemistry In a large Reaction Chamber) which was accomplished in fall 2001. The chamber consists of a 280-m^3 double-wall Teflon bag of cylindrical shape that is held by a steel frame. Typically 75% of the outside actinic flux (290~nm~--~420~nm) is available inside the chamber. A louvre system allows switching between full sun light and dark within 40 s giving the opportunity to study relaxation processes of the photo chemical system. The SAPHIR chamber is equipped with a comprehensive set of sensitive instruments including the measurements of OH, HO_2, CO, hydrocarbons, aldehydes, nitrogen-oxides and solar radiation. Moreover, the modular concept of SAPHIR allows fast and flexible integration of new instruments and techniques. In this paper we will show the unique and new features of the SAPHIR chamber, namely the clean air supply and high purity water vapor supply providing a wide range of trace gas concentrations being accessible through the experiments. We will also present examples from the first year of SAPHIR experiment showing the scope of application from high quality instrument inter-comparison and kinetic studies to the simulation of complex mixtures of trace gases at ambient concentrations.

  11. Photochemistry of Coronene in Cosmic Water Ice Analogs at Different Concentrations

    Science.gov (United States)

    de Barros, A. L. F.; Mattioda, A. L.; Ricca, A.; Cruz-Diaz, G. A.; Allamandola, L. J.

    2017-10-01

    This work presents the photochemistry of ultraviolet (UV) irradiated coronene in water ices at 15 K studied using mid-infrared Fourier transform (FTIR) spectroscopy for C24H12:H2O at concentrations of (1:50), (1:150), (1:200), (1:300), and (1:400). Previous UV irradiation studies of anthracene:H2O, pyrene:H2O, and benzo[ghi]perylene:H2O ices at 15 K have shown that aromatic alcohols and ketones, as well as CO2 and H2CO, are formed at very low temperatures. Likewise, here, in addition to the coronene cation, hydroxy-, keto-, and protonated coronene (coronene H+) are formed. The rate constants for the decay of neutral coronene and for the formation of photoproducts have been derived. It is shown that Polycyclic Aromatic Hydrocarbons (PAHs) and their UV induced PAH:H2O photoproducts have mid-infrared spectroscopic signatures in the 5-8 μm region that can contribute to the interstellar ice components described by Boogert et al. as C1-C5. Our results suggest that oxygenated and hydrogenated PAHs could be in UV-irradiated regions of the interstellar medium where water-rich ices are important.

  12. Photochemistry of Coronene in Cosmic Water Ice Analogs at Different Concentrations

    International Nuclear Information System (INIS)

    De Barros, A. L. F.; Mattioda, A. L.; Ricca, A.; Cruz-Diaz, G.A.; Allamandola, L. J.

    2017-01-01

    This work presents the photochemistry of ultraviolet (UV) irradiated coronene in water ices at 15 K studied using mid-infrared Fourier transform (FTIR) spectroscopy for C 24 H 12 :H 2 O at concentrations of (1:50), (1:150), (1:200), (1:300), and (1:400). Previous UV irradiation studies of anthracene:H 2 O, pyrene:H 2 O, and benzo[ghi]perylene:H 2 O ices at 15 K have shown that aromatic alcohols and ketones, as well as CO 2 and H 2 CO, are formed at very low temperatures. Likewise, here, in addition to the coronene cation, hydroxy-, keto-, and protonated coronene (coronene H + ) are formed. The rate constants for the decay of neutral coronene and for the formation of photoproducts have been derived. It is shown that Polycyclic Aromatic Hydrocarbons (PAHs) and their UV induced PAH:H 2 O photoproducts have mid-infrared spectroscopic signatures in the 5–8 μ m region that can contribute to the interstellar ice components described by Boogert et al. as C1–C5. Our results suggest that oxygenated and hydrogenated PAHs could be in UV-irradiated regions of the interstellar medium where water-rich ices are important.

  13. Energy transfer and photochemistry on a metal surface: Mo(CO)6 on Rh(100)

    International Nuclear Information System (INIS)

    Germer, T.A.; Ho, W.

    1989-01-01

    The occurrence of photoinduced reactions on solid surfaces depends on the relative rates between the excited-state decomposition and the energy transfer to the surface. In this study, the photodecomposition of Mo(CO) 6 on Rh(100) at 90 K by 325-nm UV irradiation has been studied as a function of coverage and surface preparation using thermal desorption spectroscopy, electron energy-loss spectroscopy, and photoinduced desorption spectroscopy. It is found that Mo(CO) 6 adsorbs dissociatively on Rh(100) into carbonyl fragments and CO in the first monolayer and molecularly in multilayers. Photoinduced desorption of CO is observed for the multilayers adsorbed onto the dissociated first layer via a nonthermal electronic excitation of adsorbed metal carbonyls. The presence of the metal surface prevents complete decarbonylation as in the gas phase; deexcitation of electronically excited carbonyls is not sufficiently fast to quench all the observed photochemistry. It is also found that Mo(CO) 6 adsorbs molecularly on a presaturated CO ordered overlayer on Rh(100) and undergoes photodissociation to a greater degree than on the dissociated and disordered surface of carbonyl fragments. The ordered CO layer effectively screens the interaction between the molecular carbonyls and the Rh(100) layer surface

  14. Interactive Photochemistry in Earth System Models to Assess Uncertainty in Ozone and Greenhouse Gases. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Prather, Michael J. [Univ. of California, Irvine, CA (United States); Hsu, Juno [Univ. of California, Irvine, CA (United States); Nicolau, Alex [Univ. of California, Irvine, CA (United States); Veidenbaum, Alex [Univ. of California, Irvine, CA (United States); Smith, Philip Cameron [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Bergmann, Dan [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2014-11-07

    Atmospheric chemistry controls the abundances and hence climate forcing of important greenhouse gases including N2O, CH4, HFCs, CFCs, and O3. Attributing climate change to human activities requires, at a minimum, accurate models of the chemistry and circulation of the atmosphere that relate emissions to abundances. This DOE-funded research provided realistic, yet computationally optimized and affordable, photochemical modules to the Community Earth System Model (CESM) that augment the CESM capability to explore the uncertainty in future stratospheric-tropospheric ozone, stratospheric circulation, and thus the lifetimes of chemically controlled greenhouse gases from climate simulations. To this end, we have successfully implemented Fast-J (radiation algorithm determining key chemical photolysis rates) and Linoz v3.0 (linearized photochemistry for interactive O3, N2O, NOy and CH4) packages in LLNL-CESM and for the first time demonstrated how change in O2 photolysis rate within its uncertainty range can significantly impact on the stratospheric climate and ozone abundances. From the UCI side, this proposal also helped LLNL develop a CAM-Superfast Chemistry model that was implemented for the IPCC AR5 and contributed chemical-climate simulations to CMIP5.

  15. Photophysics and Photochemistry of Canonical Nucleobases’ Thioanalogs: From Quantum Mechanical Studies to Time Resolved Experiments

    Directory of Open Access Journals (Sweden)

    Serra Arslancan

    2017-06-01

    Full Text Available Interest in understanding the photophysics and photochemistry of thiated nucleobases has been awakened because of their possible involvement in primordial RNA or their potential use as photosensitizers in medicinal chemistry. The interpretation of the photodynamics of these systems, conditioned by their intricate potential energy surfaces, requires the powerful interplay between experimental measurements and state of the art molecular simulations. In this review, we provide an overview on the photophysics of natural nucleobases’ thioanalogs, which covers the last 30 years and both experimental and computational contributions. For all the canonical nucleobase’s thioanalogs, we have compiled the main steady state absorption and emission features and their interpretation in terms of theoretical calculations. Then, we revise the main topographical features, including stationary points and interstate crossings, of their potential energy surfaces based on quantum mechanical calculations and we conclude, by combining the outcome of different spectroscopic techniques and molecular dynamics simulations, with the mechanism by which these nucleobase analogs populate their triplet excited states, which are at the origin of their photosensitizing properties.

  16. What do PANs Tell us about VOC-NOx Photochemistry in the Urban/Rural Interface?

    Science.gov (United States)

    Roberts, J. M.; Flocke, F. M.; Zheng, W.; Bertman, S.; Marchewka, M.; Williams, E.; Lerner, B.; Kuster, W.; Goldan, P.; Gilman, J.; Sommariva, R.; Trainer, M.; Fehsenfeld, F.

    2006-12-01

    Peroxycarboxylic Nitric Anhydrides (PANs) are co-products of the VOC-NOx photochemistry that is responsible for O3 and secondary organic aerosol (SOA) formation in the troposphere. The relative abundance of the various PAN type compounds can provide important diagnostic information as to the contribution of different VOC sources to these processes. Anthropogenic, biogenic and petrochemical VOC sources have shown distinct profiles of PAN, PPN, MPAN, PiBN, and APAN, which can be analyzed using simple numerical models and compared to the results of detailed chemical mechanisms. One result of these studies is that the PAN compounds can be used to better define the contribution of isoprene to O3 production in the urban/rural interface. Another result is that high relative concentrations of APAN are characteristic of high petrochemical source impact. In addition, changes in the relative abundance of PPN and PAN can indicate the aging of a continental photochemical plume. This paper will present selected results from five field experiments and modeling studies from the Nashville 1999 Southern Oxidant Study up through the TexAQS 2006 study, in and around Houston, TX.

  17. A novel synthesis of polymeric CO via useful hard X-ray photochemistry

    Directory of Open Access Journals (Sweden)

    Michael Pravica

    2016-12-01

    Full Text Available We report on the synchrotron hard X-ray-induced decomposition of strontium oxalate (SrC2O4 pressurized to 7 GPa inside a diamond anvil cell (DAC. After some 4 h of irradiation in a white X-ray synchrotron beam, a dark reddish/brown region formed in the area of irradiation which was surrounded by a yellowish brown remainder in the rest of the sample. Upon depressurization of the sample to ambient conditions, the reacted/decomposed sample was recoverable as a dark brown/red and yellow waxy solid. Synchrotron infrared spectroscopy confirmed the strong presence of CO2 even under ambient conditions with the sample exposed to air and other strongly absorbing regions, suggesting that the sample may likely be polymerized CO (in part with dispersed CO2 and SrO trapped within the polymer. These results will have significant implications in the ability to readily produce and trap CO2 in situ via irradiation of a simple powder for useful hard X-ray photochemistry and in the ability to easily manufacture polymeric CO (via loading of powders in a DAC or high volume press without the need for the dangerous and complex loading of toxic CO. A novel means of X-ray-induced polymerization under extreme conditions has also been demonstrated.

  18. Aerosols from fires: an examination of the effects on ozone photochemistry in the Western United States.

    Science.gov (United States)

    Jiang, Xiaoyan; Wiedinmyer, Christine; Carlton, Annmarie G

    2012-11-06

    This study presents a first attempt to investigate the roles of fire aerosols in ozone (O(3)) photochemistry using an online coupled meteorology-chemistry model, the Weather Research and Foresting model with Chemistry (WRF-Chem). Four 1-month WRF-Chem simulations for August 2007, with and without fire emissions, were carried out to assess the sensitivity of O(3) predictions to the emissions and subsequent radiative feedbacks associated with large-scale fires in the Western United States (U.S.). Results show that decreases in planetary boundary layer height (PBLH) resulting from the radiative effects of fire aerosols and increases in emissions of nitrogen oxides (NO(x)) and volatile organic compounds (VOCs) from the fires tend to increase modeled O(3) concentrations near the source. Reductions in downward shortwave radiation reaching the surface and surface temperature due to fire aerosols cause decreases in biogenic isoprene emissions and J(NO(2)) photolysis rates, resulting in reductions in O(3) concentrations by as much as 15%. Thus, the results presented in this study imply that considering the radiative effects of fire aerosols may reduce O(3) overestimation by traditional photochemical models that do not consider fire-induced changes in meteorology; implementation of coupled meteorology-chemistry models are required to simulate the atmospheric chemistry impacted by large-scale fires.

  19. The photochemistry of pyrimidine in realistic astrophysical ices and the production of nucleobases

    International Nuclear Information System (INIS)

    Nuevo, Michel; Materese, Christopher K.; Sandford, Scott A.

    2014-01-01

    Nucleobases, together with deoxyribose/ribose and phosphoric acid, are the building blocks of DNA and RNA for all known life. The presence of nucleobase-like compounds in carbonaceous chondrites delivered to the Earth raises the question of an extraterrestrial origin for the molecules that triggered life on our planet. Whether these molecules are formed in interstellar/protostellar environments, in small parent bodies in the solar system, or both, is currently unclear. Recent experiments show that the UV irradiation of pyrimidine (C 4 H 4 N 2 ) in H 2 O-rich ice mixtures that contain NH 3 , CH 3 OH, or CH 4 leads to the formation of the pyrimidine-based nucleobases uracil, cytosine, and thymine. In this work, we discuss the low-temperature UV irradiation of pyrimidine in realistic astrophysical ice mixtures containing H 2 O, CH 3 OH, and NH 3 , with or without CH 4 , to search for the production of nucleobases and other prebiotic compounds. These experiments show the presence of uracil, urea, glycerol, hexamethylenetetramine, small amino acids, and small carboxylic acids in all samples. Cytosine was only found in one sample produced from ices irradiated with a higher UV dose, while thymine was not found in any sample, even after irradiation with a higher UV dose. Results are discussed to evaluate the role of the photochemistry of pyrimidine in the inventory of organic molecules detected in meteorites and their astrophysical/astrobiological implications.

  20. Energy cascades, excited state dynamics, and photochemistry in cob(III)alamins and ferric porphyrins.

    Science.gov (United States)

    Rury, Aaron S; Wiley, Theodore E; Sension, Roseanne J

    2015-03-17

    Porphyrins and the related chlorins and corrins contain a cyclic tetrapyrrole with the ability to coordinate an active metal center and to perform a variety of functions exploiting the oxidation state, reactivity, and axial ligation of the metal center. These compounds are used in optically activated applications ranging from light harvesting and energy conversion to medical therapeutics and photodynamic therapy to molecular electronics, spintronics, optoelectronic thin films, and optomagnetics. Cobalt containing corrin rings extend the range of applications through photolytic cleavage of a unique axial carbon-cobalt bond, permitting spatiotemporal control of drug delivery. The photochemistry and photophysics of cyclic tetrapyrroles are controlled by electronic relaxation dynamics including internal conversion and intersystem crossing. Typically the electronic excitation cascades through ring centered ππ* states, ligand to metal charge transfer (LMCT) states, metal to ligand charge transfer (MLCT) states, and metal centered states. Ultrafast transient absorption spectroscopy provides a powerful tool for the investigation of the electronic state dynamics in metal containing tetrapyrroles. The UV-visible spectrum is sensitive to the oxidation state, electronic configuration, spin state, and axial ligation of the central metal atom. Ultrashort broadband white light probes spanning the range from 270 to 800 nm, combined with tunable excitation pulses, permit the detailed unravelling of the time scales involved in the electronic energy cascade. State-of-the-art theoretical calculations provide additional insight required for precise assignment of the states. In this Account, we focus on recent ultrafast transient absorption studies of ferric porphyrins and corrin containing cob(III)alamins elucidating the electronic states responsible for ultrafast energy cascades, excited state dynamics, and the resulting photoreactivity or photostability of these compounds. Iron

  1. Photochemistry Saturn's Atmosphere. 2; Effects of an Influx of External Oxygen

    Science.gov (United States)

    Moses, Julianne I.; Lellouch, Emmanuel; Bezard, Bruno; Gladstone, G. Randall; Allen, Mark

    2000-01-01

    We use a one-dimensional diurnally averaged model of photochemistry and diffusion in Saturn's stratosphere to investigate the influence of extraplanetary debris on atmospheric chemistry. In particular, we consider the effects of an influx of oxygen from micrometeoroid ablation or from ring-particle diffusion; the contribution from cometary impacts, satellite debris, or ring vapor is deemed to be less important. The photochemical model results are compared directly with Infrared Space Observatory (ISO) observations to constrain the influx of extraplanetary oxygen to Saturn. From the ISO observations, we determine that the column densities of CO2 and H2O above 10 mbar in Saturn's atmosphere are (6.3 +/- 1) x 10(exp 14) and (1.4 +/- 0.4) x 10(exp 15)/ square cm, respectively; our models indicate that a globally averaged oxygen influx of (4+/-2) x 10(exp 6) O atoms /sq cm/s is required to explain these observations. Models with a locally enhanced influx of H20 operating over a small fraction of the projected area do not provide as good a fit to the ISO H2O observations. If volatile oxygen compounds comprise one-third to one-half of the exogenic source by mass, then Saturn is currently being bombarded with (3 +/- 2) x 10(exp -16) g/square cm/s of extraplanetary material. To reproduce the observed CO2/H2O ratio in Saturn's stratosphere, some of the exogenic oxygen must arrive in the form of a carbon-oxygen bonded species such as CO or CO2. An influx consistent with the composition of cometary ices fails to reproduce the high observed CO2/H2O ratio, suggesting that (i) the material has ices that are slightly more carbon-rich than is typical for comets, (ii) a contribution from an organic-rich component is required, or (iii) some of the hydrogen-oxygen bonded material is converted to carbon-oxygen bonded material without photochemistry (e.g., during the ablation process). We have also reanalyzed the 5-micron CO observations of Noll and Larson and determine that the CO

  2. Aerosol effects on the photochemistry in Mexico City during MCMA-2006/MILAGRO campaign

    Directory of Open Access Journals (Sweden)

    G. Li

    2011-06-01

    Full Text Available In the present study, the impact of aerosols on the photochemistry in Mexico City is evaluated using the WRF-CHEM model for the period from 24 to 29 March during the MCMA-2006/MILAGRO campaign. An aerosol radiative module has been developed with detailed consideration of aerosol size, composition, and mixing. The module has been coupled into the WRF-CHEM model to calculate the aerosol optical properties, including optical depth, single scattering albedo, and asymmetry factor. Calculated aerosol optical properties are in good agreement with the surface observations and aircraft and satellite measurements during daytime. In general, the photolysis rates are reduced due to the absorption by carbonaceous aerosols, particularly in the early morning and late afternoon hours with a long aerosol optical path. However, with the growth of aerosol particles and the decrease of the solar zenith angle around noontime, aerosols can slightly enhance photolysis rates when ultraviolet (UV radiation scattering dominates UV absorption by aerosols at the lower-most model layer. The changes in photolysis rates due to aerosols lead to about 2–17 % surface ozone reduction during daytime in the urban area in Mexico City with generally larger reductions during early morning hours near the city center, resulting in a decrease of OH level by about 9 %, as well as a decrease in the daytime concentrations of nitrate and secondary organic aerosols by 5–6 % on average. In addition, the rapid aging of black carbon aerosols and the enhanced absorption of UV radiation by organic aerosols contribute substantially to the reduction of photolysis rates.

  3. Structure and UV-induced photochemistry of 2-furaldehyde dimethylhydrazone isolated in rare gas matrices

    Science.gov (United States)

    Araujo-Andrade, C.; Giuliano, B. M.; Gómez-Zavaglia, A.; Fausto, R.

    2012-11-01

    In this work, a combined matrix isolation FTIR and theoretical DFT(B3LYP)/6-311++G(d,p) study of 2-furaldehyde dimethylhydrazone (2FDH) was performed. According to calculations, two E and two Z conformers exist, the E forms having considerably lower energy than the Z forms. The absence of relevant sterical hindrance between the two substituents around the Cdbnd N bond (dimethylamino and 2-furyl) in the E structures and an extended π-p electron delocalization in the hydrazone moiety determines the higher stability of these species relatively to the Z structures. In the lowest energy form (E-AG) the O-C-Cdbnd N and Cdbnd N-N-Lp (Lp = lone electron pair of amine nitrogen atom) dihedral angles are predicted by the calculations to be -177.2° and 93.7°, respectively. The weak (Ndbnd C)-H⋯O hydrogen bond type interaction (H⋯O distance: 252.2 pm) in form E-AG, together with the absence in this form of the destabilizing interaction between the lone electron pairs of the oxygen and nitrogen atoms existing in E-SG, explains its lower energy in comparison with this latter form. Both E-AG and E-SG conformers could be trapped from room temperature gas phase in low temperature argon and xenon matrices. The high E-SG → E-AG energy barrier (>25 kJ mol-1) explains that, upon increasing the temperature of the matrices no conformational isomerization could be observed. After irradiation of 2FDH with UV-light at λ > 328 and λ > 234 nm, two different photochemistries were observed. Irradiation at lower energy (λ > 328 nm) induced the E-AG → E-SG isomerization. Further irradiation at higher energy (λ > 234 nm) led to a quick consumption of 2FDH and production of furan and dimethylisocyanide.

  4. Ultrafast infrared and UV-vis studies of the photochemistry of methoxycarbonylphenyl azides in solution.

    Science.gov (United States)

    Xue, Jiadan; Luk, Hoi Ling; Eswaran, S V; Hadad, Christopher M; Platz, Matthew S

    2012-06-07

    The photochemistry of 4-methoxycarbonylphenyl azide (2a), 2-methoxycarbonylphenyl azide (3a), and 2-methoxy-6-methoxycarbonylphenyl azide (4a) were studied by ultrafast time-resolved infrared (IR) and UV-vis spectroscopies in solution. Singlet nitrenes and ketenimines were observed and characterized for all three azides. Isoxazole species 3g and 4g are generated after photolysis of 3a and 4a, respectively, in acetonitrile. Triplet nitrene 4e formation correlated with the decay of singlet nitrene 4b. The presence of water does not change the chemistry or kinetics of singlet nitrenes 2b and 3b, but leads to protonation of 4b to produce nitrenium ion 4f. Singlet nitrenes 2b and 3b have lifetimes of 2 ns and 400 ps, respectively, in solution at ambient temperature. The singlet nitrene 4b in acetonitrile has a lifetime of about 800 ps, and reacts with water with a rate constant of 1.9 × 10(8) L·mol(-1)·s(-1) at room temperature. These results indicate that a methoxycarbonyl group at either the para or ortho positions has little influence on the ISC rate, but that the presence of a 2-methoxy group dramatically accelerates the ISC rate relative to the unsubstituted phenylnitrene. An ortho-methoxy group highly stabilizes the corresponding nitrenium ion and favors its formation in aqueous solvents. This substituent has little influence on the ring-expansion rate. These results are consistent with theoretical calculations for the various intermediates and their transition states. Cyclization from the nitrene to the azirine intermediate is favored to proceed toward the electron-deficient ester group; however, the higher energy barrier is the ring-opening process, that is, azirine to ketenimine formation, rendering the formation of the ester-ketenimine (4d') to be less favorable than the isomeric MeO-ketenimine (4d).

  5. Interfacial photochemistry of biogenic surfactants: a major source of abiotic volatile organic compounds.

    Science.gov (United States)

    Brüggemann, Martin; Hayeck, Nathalie; Bonnineau, Chloé; Pesce, Stéphane; Alpert, Peter A; Perrier, Sébastien; Zuth, Christoph; Hoffmann, Thorsten; Chen, Jianmin; George, Christian

    2017-08-24

    Films of biogenic compounds exposed to the atmosphere are ubiquitously found on the surfaces of cloud droplets, aerosol particles, buildings, plants, soils and the ocean. These air/water interfaces host countless amphiphilic compounds concentrated there with respect to in bulk water, leading to a unique chemical environment. Here, photochemical processes at the air/water interface of biofilm-containing solutions were studied, demonstrating abiotic VOC production from authentic biogenic surfactants under ambient conditions. Using a combination of online-APCI-HRMS and PTR-ToF-MS, unsaturated and functionalized VOCs were identified and quantified, giving emission fluxes comparable to previous field and laboratory observations. Interestingly, VOC fluxes increased with the decay of microbial cells in the samples, indicating that cell lysis due to cell death was the main source for surfactants and VOC production. In particular, irradiation of samples containing solely biofilm cells without matrix components exhibited the strongest VOC production upon irradiation. In agreement with previous studies, LC-MS measurements of the liquid phase suggested the presence of fatty acids and known photosensitizers, possibly inducing the observed VOC production via peroxy radical chemistry. Up to now, such VOC emissions were directly accounted to high biological activity in surface waters. However, the results obtained suggest that abiotic photochemistry can lead to similar emissions into the atmosphere, especially in less biologically-active regions. Furthermore, chamber experiments suggest that oxidation (O 3 /OH radicals) of the photochemically-produced VOCs leads to aerosol formation and growth, possibly affecting atmospheric chemistry and climate-related processes, such as cloud formation or the Earth's radiation budget.

  6. Photochemistry and photobiology of actinic erythema: defensive and reparative cutaneous mechanisms

    Directory of Open Access Journals (Sweden)

    A.C. Tedesco

    1997-05-01

    Full Text Available Sunlight is part of our everyday life and most people accept it as beneficial to our health. With the advance of our knowledge in cutaneous photochemistry, photobiology and photomedicine over the past four decades, the terrestrial solar radiation has become a concern of dermatologists and is considered to be a major damaging environmental factor for our skin. Most photobiological effects (e.g., sunburn, suntanning, local and systemic immunosuppression, photoaging or dermatoheliosis, skin cancer and precancer, etc. are attributed to ultraviolet radiation (UVR and more particularly to UVB radiation (290-320 nm. UVA radiation (320-400 nm also plays an important role in the induction of erythema by the photosensitized generation of reactive oxygen species (singlet oxygen (1O2, superoxide (O2.- and hydroxyl radicals (.OH that damage DNA and cellular membranes, and promote carcinogenesis and the changes associated with photoaging. Therefore, research efforts have been directed at a better photochemical and photobiological understanding of the so-called sunburn reaction, actinic or solar erythema. To survive the insults of actinic damage, the skin appears to have different intrinsic defensive mechanisms, among which antioxidants (enzymatic and non-enzymatic systems play a pivotal role. In this paper, we will review the basic aspects of the action of UVR on the skin: a photochemical reactions resulting from photon absorption by endogenous chromophores; b the lipid peroxidation phenomenon, and c intrinsic defensive cutaneous mechanisms (antioxidant systems. The last section will cover the inflammatory response including mediator release after cutaneous UVR exposure and adhesion molecule expression

  7. Photosystem II Photochemistry and Phycobiliprotein of the Red Algae Kappaphycus alvarezii and Their Implications for Light Adaptation

    OpenAIRE

    Guan, Xiangyu; Wang, Jinfeng; Zhu, Jianyi; Yao, Chunyan; Liu, Jianguo; Qin, Song; Jiang, Peng

    2013-01-01

    Photosystem II photochemistry and phycobiliprotein (PBP) genes of red algae Kappaphycus alvarezii, raw material of κ -carrageenan used in food and pharmaceutical industries, were analyzed in this study. Minimum saturating irradiance (I k ) of this algal species was less than 115  μ mol m−2 s−1. Its actual PSII efficiency (yield II) increased when light intensity enhanced and decreased when light intensity reached 200  μ mol m−2 s−1. Under dim light, yield II declined at first and then increas...

  8. Sunscreen synthesis and their immobilisation on polymethylmethacrylate: an integrated project in organic chemistry, polymer chemistry and photochemistry

    International Nuclear Information System (INIS)

    Murtinho, Dina Maria B.; Serra, Maria Elisa S.; Pineiro, Marta

    2010-01-01

    Dibenzalacetone and other aldol condensation products are known sunscreens commonly used in cosmetics. This type of compounds can easily be prepared in an Organic Chemistry Lab by reaction of aldehydes with ketones in basic medium. These compounds can be incorporated in poly(methyl methacrylate) and used as UV light absorbers, for example in sunglasses. This project has the advantage of using inexpensive reagents which are readily available in Chemistry Laboratories. This experiment can also be a base starting point for discussions of organic, polymer and photochemistry topics. (author)

  9. Photochemistry of 1,1,1-Trifluoroacetone on Rutile TiO2(110)

    International Nuclear Information System (INIS)

    Zehr, Robert T.; Deskins, N. Aaron; Henderson, Michael A.

    2010-01-01

    The ultraviolet (UV) photon-induced photodecomposition of 1,1,1-trifluoroacetone (TFA) adsorbed on the rutile TiO2(110) surface has been investigated with photon stimulated desorption (PSD), temperature programmed desorption (TPD) and density functional theory (DFT). TFA adsorbed molecularly on the reduced surface (8% oxygen vacancies) in states desorbing below 300 K with trace thermal decomposition observed in TPD. Adsorption of TFA on a preoxidized TiO2(110) surface (accomplished by pre-exposure with 20 L O2) led to formation of a new TFA desorption state at 350 K, assigned to decomposition of a TFA-diolate species ((CF3)(CH3)COO). No TFA photochemistry was detected on the reduced surface. UV irradiation of TFA on the oxidized surface depleted TFA in the 350 K state, with TFA molecules in other TPD states unaffected. PSD measurements reveal that both carbonyl substituents (CH3 and CF3), as well as CO, were liberated during UV exposure at 95 K. Post-irradiation TPD showed evidence for both acetate (evolving as ketene at 650 K) and trifluoroacetate (evolving as CO2 at 600 K) as surface-bound photodecomposition products. The CO PSD product was not due to adsorbed CO, to mass spectrometer cracking of a CO-containing PSD product, or from background effects, but originated from complete fragmentation of an unidentified adsorbed TFA species. Thermodynamic analysis using DFT indicated that the photodecomposition of the TFA-diolate was likely not driven by thermodynamics alone as both pathways (CH3+trifluoroacetate and CF3+acetate) were detected when thermodynamics shows a clear preference for only one (CF3+acetate). These observations are in contrast to the photochemical behavior of acetone, butanone and acetaldehyde on TiO2(110), where only one of the two carbonyl substituent groups was observed, with a stoichiometric amount of carboxylate containing the other substituent left on the surface. We conclude that fluorination significantly alters the electronic structure of

  10. Structure and photochemistry of a novel tetrazole-saccharyl conjugate isolated in solid argon

    Science.gov (United States)

    Ismael, A.; Borba, A.; Duarte, L.; Giuliano, B. M.; Gómez-Zavaglia, A.; Cristiano, M. L. S.

    2012-10-01

    A combined matrix isolation FTIR and theoretical DFT/B3LYP/6-311++G(3df,3pd) study of the novel synthesised tetrazole-saccharyl conjugate 2-[1-(1H-tetrazol-5-yl)ethyl]-1,2-benzisothiazol-3(2H)-one 1,1-dioxide [1-TE-BZT] was performed. In the gas phase, at room temperature, the compound exists as a mixture of six isomeric forms (four conformers of 1H tautomer and two conformers of 2H tautomer). According to theoretical calculations, conformers 1H were the most stable and the relative energies among the three most stable forms are lower than 4 kJ mol-1. These conformers benefit from stabilising intramolecular hydrogen bonds-like interactions involving the 1H of the tetrazole ring and the carbonyl oxygen of the saccharyl moiety. The photochemistry of 1-TE-BZT in solid argon was investigated and theoretical DFT/B3LYP/6-311++G(3df,3pd) calculations also helped in assignment of the experimental bands. A quick consumption of the compound occurred after irradiation of the matrix with UV laser light at λ = 275 nm. Three photofragmentation pathways were proposed, one leading to 2-[1-(1H-diaziren-3-yl)ethyl]-1,2-benzisothiazol-3(2H)-one 1,1-dioxide and molecular nitrogen, a second one giving 2-(1,1-dioxide-3-oxo-1,2-benzisothiazol-2(3H)-yl)propanenitrile and azide, and a third one involving loss of azide from the tetrazole ring and decarbonylation of the saccharyl ring of 1-TE-BZT to give acrylonitrile and 7-thia-8-azabicyclo[4.2.0] octa-1,3,5-triene 7,7 dioxide. The comparison of the relative intensities of the bands of the photoproducts obtained from the three channels allowed us to consider the latter pathway, involving an unprecedented photocleavage of the benzisothiazole (saccharyl) ring, as the preferred photodegradation channel of 1-TE-BZT.

  11. Exogenous Calcium Enhances the Photosystem II Photochemistry Response in Salt Stressed Tall Fescue.

    Science.gov (United States)

    Wang, Guangyang; Bi, Aoyue; Amombo, Erick; Li, Huiying; Zhang, Liang; Cheng, Cheng; Hu, Tao; Fu, Jinmin

    2017-01-01

    Calcium enhances turfgrass response to salt stress. However, little is known about PSII photochemical changes when exogenous calcium was applied in salinity-stressed turfgrass. Here, we probe into the rearrangements of PSII electron transport and endogenous ion accumulation in tall fescue ( Festuca arundinacea Schreber) treated with exogenous calcium under salt stress. Three-month-old seedlings of genotype "TF133" were subjected to the control (CK), salinity (S), salinity + calcium nitrate (SC), and salinity + ethylene glycol tetraacetic acid (SE). Calcium nitrate and ethylene glycol tetraacetic acid was used as exogenous calcium donor and calcium chelating agent respectively. At the end of a 5-day duration treatment, samples in SC regime had better photochemistry performance on several parameters than salinity only. Such as the Area (equal to the plastoquinone pool size), N (number of [Formula: see text] redox turnovers until F m is reached), ψE 0 , or δRo (Efficiencdy/probability with which a PSII trapped electron is transferred from Q A to Q B or PSI acceptors), ABS/RC (Absorbed photon flux per RC). All the above suggested that calcium enhanced the electron transfer of PSII (especially beyond [Formula: see text]) and prevented reaction centers from inactivation in salt-stressed tall fescue. Furthermore, both grass shoot and root tissues generally accumulated more C, N, Ca 2+ , and K + in the SC regime than S regime. Interrelated analysis indicated that ψE 0 , δRo, ABS/RC, C, and N content in shoots was highly correlated to each other and significantly positively related to Ca 2+ and K + content in roots. Besides, high salt increased ATP6E and CAMK2 transcription level in shoot at 1 and 5 day, respectively while exogenous calcium relieved it. In root, CAMK2 level was reduced by Salinity at 5 day and exogenous calcium recovered it. These observations involved in electron transport capacity and ion accumulation assist in understanding better the protective role

  12. Exogenous Calcium Enhances the Photosystem II Photochemistry Response in Salt Stressed Tall Fescue

    Directory of Open Access Journals (Sweden)

    Guangyang Wang

    2017-11-01

    Full Text Available Calcium enhances turfgrass response to salt stress. However, little is known about PSII photochemical changes when exogenous calcium was applied in salinity-stressed turfgrass. Here, we probe into the rearrangements of PSII electron transport and endogenous ion accumulation in tall fescue (Festuca arundinacea Schreber treated with exogenous calcium under salt stress. Three-month-old seedlings of genotype “TF133” were subjected to the control (CK, salinity (S, salinity + calcium nitrate (SC, and salinity + ethylene glycol tetraacetic acid (SE. Calcium nitrate and ethylene glycol tetraacetic acid was used as exogenous calcium donor and calcium chelating agent respectively. At the end of a 5-day duration treatment, samples in SC regime had better photochemistry performance on several parameters than salinity only. Such as the Area (equal to the plastoquinone pool size, N (number of QA- redox turnovers until Fm is reached, ψE0, or δRo (Efficiencdy/probability with which a PSII trapped electron is transferred from QA to QB or PSI acceptors, ABS/RC (Absorbed photon flux per RC. All the above suggested that calcium enhanced the electron transfer of PSII (especially beyond QA- and prevented reaction centers from inactivation in salt-stressed tall fescue. Furthermore, both grass shoot and root tissues generally accumulated more C, N, Ca2+, and K+ in the SC regime than S regime. Interrelated analysis indicated that ψE0, δRo, ABS/RC, C, and N content in shoots was highly correlated to each other and significantly positively related to Ca2+ and K+ content in roots. Besides, high salt increased ATP6E and CAMK2 transcription level in shoot at 1 and 5 day, respectively while exogenous calcium relieved it. In root, CAMK2 level was reduced by Salinity at 5 day and exogenous calcium recovered it. These observations involved in electron transport capacity and ion accumulation assist in understanding better the protective role of exogenous calcium in tall

  13. Heterogeneous photochemistry of imidazole-2-carboxaldehyde: HO2 radical formation and aerosol growth

    Directory of Open Access Journals (Sweden)

    L. González Palacios

    2016-09-01

    Full Text Available The multiphase chemistry of glyoxal is a source of secondary organic aerosol (SOA, including its light-absorbing product imidazole-2-carboxaldehyde (IC. IC is a photosensitizer that can contribute to additional aerosol ageing and growth when its excited triplet state oxidizes hydrocarbons (reactive uptake via H-transfer chemistry. We have conducted a series of photochemical coated-wall flow tube (CWFT experiments using films of IC and citric acid (CA, an organic proxy and H donor in the condensed phase. The formation rate of gas-phase HO2 radicals (PHO2 was measured indirectly by converting gas-phase NO into NO2. We report on experiments that relied on measurements of NO2 formation, NO loss and HONO formation. PHO2 was found to be a linear function of (1 the [IC]  ×  [CA] concentration product and (2 the photon actinic flux. Additionally, (3 a more complex function of relative humidity (25 %  <  RH  <  63 % and of (4 the O2 ∕ N2 ratio (15 %  <  O2 ∕ N2  <  56 % was observed, most likely indicating competing effects of dilution, HO2 mobility and losses in the film. The maximum PHO2 was observed at 25–55 % RH and at ambient O2 ∕ N2. The HO2 radicals form in the condensed phase when excited IC triplet states are reduced by H transfer from a donor, CA in our system, and subsequently react with O2 to regenerate IC, leading to a catalytic cycle. OH does not appear to be formed as a primary product but is produced from the reaction of NO with HO2 in the gas phase. Further, seed aerosols containing IC and ammonium sulfate were exposed to gas-phase limonene and NOx in aerosol flow tube experiments, confirming significant PHO2 from aerosol surfaces. Our results indicate a potentially relevant contribution of triplet state photochemistry for gas-phase HO2 production, aerosol growth and ageing in the atmosphere.

  14. Surface Photochemistry of Adsorbed Nitrate: The Role of Adsorbed Water in the Formation of Reduced Nitrogen Species on α-Fe2O3 Particle Surfaces

    NARCIS (Netherlands)

    Nanayakkara, C.E.; Jayaweera, P.M.; Rubasinghege, G; Baltrusaitis, Jonas; Grassian, V.H.

    2014-01-01

    The surface photochemistry of nitrate, formed from nitric acid adsorption, on hematite (α-Fe2O3) particle surfaces under different environmental conditions is investigated using X-ray photoelectron spectroscopy (XPS). Following exposure of α-Fe2O3 particle surfaces to gas-phase nitric acid, a peak

  15. Photovoltaic device

    Energy Technology Data Exchange (ETDEWEB)

    Reese, Jason A; Keenihan, James R; Gaston, Ryan S; Kauffmann, Keith L; Langmaid, Joseph A; Lopez, Leonardo; Maak, Kevin D; Mills, Michael E; Ramesh, Narayan; Teli, Samar R

    2017-03-21

    The present invention is premised upon an improved photovoltaic device ("PV device"), more particularly to an improved photovoltaic device with a multilayered photovoltaic cell assembly and a body portion joined at an interface region and including an intermediate layer, at least one interconnecting structural member, relieving feature, unique component geometry, or any combination thereof.

  16. Photovoltaic device

    Science.gov (United States)

    Reese, Jason A.; Keenihan, James R.; Gaston, Ryan S.; Kauffmann, Keith L.; Langmaid, Joseph A.; Lopez, Leonardo C.; Maak, Kevin D.; Mills, Michael E.; Ramesh, Narayan; Teli, Samar R.

    2015-06-02

    The present invention is premised upon an improved photovoltaic device ("PV device"), more particularly to an improved photovoltaic device with a multilayered photovoltaic cell assembly and a body portion joined at an interface region and including an intermediate layer, at least one interconnecting structural member, relieving feature, unique component geometry, or any combination thereof.

  17. Photovoltaic device

    Science.gov (United States)

    Reese, Jason A.; Keenihan, James R.; Gaston, Ryan S.; Kauffmann, Keith L.; Langmaid, Joseph A.; Lopez, Leonardo C.; Maak, Kevin D.; Mills, Michael E.; Ramesh, Narayan; Teli, Samar R.

    2015-09-01

    The present invention is premised upon an improved photovoltaic device ("PV device"), more particularly to an improved photovoltaic device (10) with a multilayered photovoltaic cell assembly (100) and a body portion (200) joined at an interface region (410) and including an intermediate layer (500), at least one interconnecting structural member (1500), relieving feature (2500), unique component geometry, or any combination thereof.

  18. Possible impact of multi-electron loss events on the average beam charge state in an HIF target chamber and a neutral beam approach

    Science.gov (United States)

    Grisham, L. R.

    2001-05-01

    Experiments were carried out during the early 1980s to assess the obtainable atomic neutralization of energetic beams of negative ions ranging from lithium to silicon. The experiments found (Grisham et al. Rev. Sci. Instrum. 53 (1982) 281; Princeton Plasma Physics Laboratory Report PPPL-1857, 1981) that, for higher atomic number elements than lithium, it appeared that a substantial fraction of the time more than one electron was being lost in a single collision. This result was inferred from the existence of more than one ionization state in the product beam for even the thinnest line densities at which any electron removal took place. Because of accelerator limitations, these experiments were limited to maximum energies of 7 MeV. However, based upon these results, it is possible that multi-electron loss events may also play a significant role in determining the average ion charge state of the much higher Z and more energetic beams traversing the medium in an heavy ion fusion chamber. This could result in the beam charge state being considerably higher than previously anticipated, and might require designers to consider harder vacuum ballistic focusing approaches, or the development of additional space charge neutralization schemes. This paper discusses the measurements that gave rise for these concerns, as well as a description of further measurements that are proposed to be carried out for atomic numbers and energies per amu which would be closer to those required for heavy ion fusion drivers. With a very low current beam of a massive, but low charge state energetic ion, the charge state distribution emerging from a target gas cell could be measured as a function of line density and medium composition. Varying the line density would allow one to simulate the charge state evolution of the beam as a function of distance into the target chamber. This paper also briefly discusses a possible alternative driver approach using photodetachment-neutralized atomic beams

  19. Thermally and vibrationally induced conformational isomerizations, infrared spectra, and photochemistry of gallic acid in low-temperature matrices

    Science.gov (United States)

    Justino, Licínia L. G.; Reva, Igor; Fausto, Rui

    2016-07-01

    Near-infrared (near-IR) narrowband selective vibrational excitation and annealing of gallic acid (3,4,5-trihydroxybenzoic acid) isolated in cryogenic matrices were used to induce interconversions between its most stable conformers. The isomerizations were probed by infrared spectroscopy. An extensive set of quantum chemical calculations, carried out at the DFT(B3LYP)/6-311++G(d,p) level of approximation, was used to undertake a detailed analysis of the ground state potential energy surface of the molecule. This investigation of the molecule conformational space allowed extracting mechanistic insights into the observed annealing- or near-IR-induced isomerization processes. The infrared spectra of the two most stable conformers of gallic acid in N2, Xe, and Ar matrices were fully assigned. Finally, the UV-induced photochemistry of the matrix isolated compound was investigated.

  20. Thermally and vibrationally induced conformational isomerizations, infrared spectra, and photochemistry of gallic acid in low-temperature matrices

    International Nuclear Information System (INIS)

    Justino, Licínia L. G.; Reva, Igor; Fausto, Rui

    2016-01-01

    Near-infrared (near-IR) narrowband selective vibrational excitation and annealing of gallic acid (3,4,5-trihydroxybenzoic acid) isolated in cryogenic matrices were used to induce interconversions between its most stable conformers. The isomerizations were probed by infrared spectroscopy. An extensive set of quantum chemical calculations, carried out at the DFT(B3LYP)/6-311++G(d,p) level of approximation, was used to undertake a detailed analysis of the ground state potential energy surface of the molecule. This investigation of the molecule conformational space allowed extracting mechanistic insights into the observed annealing- or near-IR-induced isomerization processes. The infrared spectra of the two most stable conformers of gallic acid in N 2 , Xe, and Ar matrices were fully assigned. Finally, the UV-induced photochemistry of the matrix isolated compound was investigated.

  1. Estimated SAGE II ozone mixing ratios in early 1993 and comparisons with Stratospheric Photochemistry, Aerosols and Dynamic Expedition measurements

    Science.gov (United States)

    Yue, G. K.; Veiga, R. E.; Poole, L. R.; Zawodny, J. M.; Proffitt, M. H.

    1994-01-01

    An empirical time-series model for estimating ozone mixing ratios based on Stratospheric Aerosols and Gas Experiment II (SAGE II) monthly mean ozone data for the period October 1984 through June 1991 has been developed. The modeling results for ozone mixing ratios in the 10- to 30- km region in early months of 1993 are presented. In situ ozone profiles obtained by a dual-beam UV-absorption ozone photometer during the Stratospheric Photochemistry, Aerosols and Dynamics Expedition (SPADE) campaign, May 1-14, 1993, are compared with the model results. With the exception of two profiles at altitudes below 16 km, ozone mixing ratios derived by the model and measured by the ozone photometer are in relatively good agreement within their individual uncertainties. The identified discrepancies in the two profiles are discussed.

  2. Thermally and vibrationally induced conformational isomerizations, infrared spectra, and photochemistry of gallic acid in low-temperature matrices

    Energy Technology Data Exchange (ETDEWEB)

    Justino, Licínia L. G., E-mail: liciniaj@ci.uc.pt; Reva, Igor; Fausto, Rui [CQC, Department of Chemistry, University of Coimbra, 3004-535 Coimbra (Portugal)

    2016-07-07

    Near-infrared (near-IR) narrowband selective vibrational excitation and annealing of gallic acid (3,4,5-trihydroxybenzoic acid) isolated in cryogenic matrices were used to induce interconversions between its most stable conformers. The isomerizations were probed by infrared spectroscopy. An extensive set of quantum chemical calculations, carried out at the DFT(B3LYP)/6-311++G(d,p) level of approximation, was used to undertake a detailed analysis of the ground state potential energy surface of the molecule. This investigation of the molecule conformational space allowed extracting mechanistic insights into the observed annealing- or near-IR-induced isomerization processes. The infrared spectra of the two most stable conformers of gallic acid in N{sub 2}, Xe, and Ar matrices were fully assigned. Finally, the UV-induced photochemistry of the matrix isolated compound was investigated.

  3. Compact Solid-State 213 nm Laser Enables Standoff Deep Ultraviolet Raman Spectrometer: Measurements of Nitrate Photochemistry.

    Science.gov (United States)

    Bykov, Sergei V; Mao, Michael; Gares, Katie L; Asher, Sanford A

    2015-08-01

    We describe a new compact acousto-optically Q-switched diode-pumped solid-state (DPSS) intracavity frequency-tripled neodymium-doped yttrium vanadate laser capable of producing ~100 mW of 213 nm power quasi-continuous wave as 15 ns pulses at a 30 kHz repetition rate. We use this new laser in a prototype of a deep ultraviolet (UV) Raman standoff spectrometer. We use a novel high-throughput, high-resolution Echelle Raman spectrograph. We measure the deep UV resonance Raman (UVRR) spectra of solid and solution sodium nitrate (NaNO3) and ammonium nitrate (NH4NO3) at a standoff distance of ~2.2 m. For this 2.2 m standoff distance and a 1 min spectral accumulation time, where we only monitor the symmetric stretching band, we find a solid state NaNO3 detection limit of ~100 μg/cm(2). We easily detect ~20 μM nitrate water solutions in 1 cm path length cells. As expected, the aqueous solutions UVRR spectra of NaNO3 and NH4NO3 are similar, showing selective resonance enhancement of the nitrate (NO3(-)) vibrations. The aqueous solution photochemistry is also similar, showing facile conversion of NO3(-) to nitrite (NO2(-)). In contrast, the observed UVRR spectra of NaNO3 and NH4NO3 powders significantly differ, because their solid-state photochemistries differ. Whereas solid NaNO3 photoconverts with a very low quantum yield to NaNO2, the NH4NO3 degrades with an apparent quantum yield of ~0.2 to gaseous species.

  4. Sources and photochemistry of volatile organic compounds in the remote atmosphere of western China: results from the Mt. Waliguan Observatory

    Directory of Open Access Journals (Sweden)

    L. K. Xue

    2013-09-01

    Full Text Available The chemistry of the natural atmosphere and the influence by long-range transport of air pollution are key issues in the atmospheric sciences. Here we present two intensive field measurements of volatile organic compounds (VOCs in late spring and summer of 2003 at Mt. Waliguan (WLG, 36.28° N, 100.90° E, 3816 m a.s.l., a baseline station in the northeast part of the Qinghai-Tibetan Plateau. Most VOC species exhibited higher concentrations in late spring than in summer. A typical diurnal variation was observed with higher nighttime levels, in contrast to results from other mountainous sites. Five different air masses were identified from backward trajectory analysis showing distinct VOC speciation. Air masses originating from the central Eurasian continent contained the lowest VOC levels compared to the others that were impacted by anthropogenic emissions from China and the Indian subcontinent. A photochemical box model based on the Master Chemical Mechanism (version 3.2 and constrained by a full suite of measurements was developed to probe the photochemistry of atmosphere at WLG. Our results show net ozone production from in situ photochemistry during both late spring and summer. Oxidation of nitric oxide (NO by the hydroperoxyl radical (HO2 dominates the ozone production relative to the oxidation by the organic peroxy radicals (RO2, and the ozone is primarily destroyed by photolysis and reactions with the HOx (HOx = OH + HO2 radicals. Ozone photolysis is the predominant primary source of radicals (ROx = OH + HO2 + RO2, followed by the photolysis of secondary oxygenated VOCs and hydrogen peroxides. The radical losses are governed by the self and cross reactions among the radicals. Overall, the findings of the present study provide insights into the background chemistry and the impacts of pollution transport on the pristine atmosphere over the Eurasian continent.

  5. Sealing device

    Science.gov (United States)

    Garcia-Crespo, Andres Jose

    2013-12-10

    A sealing device for sealing a gap between a dovetail of a bucket assembly and a rotor wheel is disclosed. The sealing device includes a cover plate configured to cover the gap and a retention member protruding from the cover plate and configured to engage the dovetail. The sealing device provides a seal against the gap when the bucket assemply is subjected to a centrifugal force.

  6. Microfluidic Device

    Science.gov (United States)

    Tai, Yu-Chong (Inventor); Zheng, Siyang (Inventor); Lin, Jeffrey Chun-Hui (Inventor); Kasdan, Harvey L. (Inventor)

    2017-01-01

    Described herein are particular embodiments relating to a microfluidic device that may be utilized for cell sensing, counting, and/or sorting. Particular aspects relate to a microfabricated device that is capable of differentiating single cell types from dense cell populations. One particular embodiment relates a device and methods of using the same for sensing, counting, and/or sorting leukocytes from whole, undiluted blood samples.

  7. Gauging device

    International Nuclear Information System (INIS)

    Qurnell, F.D.; Patterson, C.B.

    1979-01-01

    A gauge supporting device for measuring say a square tube comprises a pair of rods or guides in tension between a pair of end members, the end members being spaced apart by a compression member or members. The tensioned guides provide planes of reference for measuring devices moved therealong on a carriage. The device is especially useful for making on site dimensional measurements of components, such as irradiated and therefore radioactive components, that cannot readily be transported to an inspection laboratory. (UK)

  8. Fusion devices

    International Nuclear Information System (INIS)

    Fowler, T.K.

    1977-01-01

    Three types of thermonuclear fusion devices currently under development are reviewed for an electric utilities management audience. Overall design features of laser fusion, tokamak, and magnetic mirror type reactors are described and illustrated. Thrusts and trends in current research on these devices that promise to improve performance are briefly reviewed. Twenty photographs and drawings are included

  9. BRAKE DEVICE

    Science.gov (United States)

    O'Donnell, T.J.

    1959-03-10

    A brake device is described for utilization in connection with a control rod. The device comprises a pair of parallelogram link mechanisms, a control rod moveable rectilinearly therebetween in opposite directions, and shoes resiliently supported by the mechanism for frictional engagement with the control rod.

  10. PLASMA DEVICE

    Science.gov (United States)

    Gow, J.D.; Wilcox, J.M.

    1961-12-26

    A device is designed for producing and confining highenergy plasma from which neutrons are generated in copious quantities. A rotating sheath of electrons is established in a radial electric field and axial magnetic field produced within the device. The electron sheath serves as a strong ionizing medium to gas introdueed thereto and also functions as an extremely effective heating mechanism to the resulting plasma. In addition, improved confinement of the plasma is obtained by ring magnetic mirror fields produced at the ends of the device. Such ring mirror fields are defined by the magnetic field lines at the ends of the device diverging radially outward from the axis of the device and thereafter converging at spatial annular surfaces disposed concentrically thereabout. (AFC)

  11. Combined effect of diuron and simazine on photosystem II photochemistry in a sandy soil and soil amended with solid olive-mill waste.

    Science.gov (United States)

    Redondo-Gómez, Susana; Cox, Lucía; Cornejo, Juan; Figueroa, Enrique

    2007-01-01

    Diuron (3-(3,4-dichlorophenyl)- = 1,1-dimethylurea) and simazine (6-chloro-N(2), N(4)-diethyl-1,3,5-triazine-2,4-diamine) are soil-applied herbicides used in olive crops. The objective of this study is to investigate the effect of these herbicides on Photosystem II photochemistry of Olea europaea L., and whether the amendment of soil with an organic waste (OW) from olive oil production industry modifies this effect. For this purpose, herbicide soil adsorption studies, with unamended and OW-amended soil, and chlorophyll fluorescence measurements in adult olive leaves, after one, two and three weeks of soil herbicide treatment and/or OW amendment, were performed. Soil application of these herbicides reduced the efficiency of Photosystem II photochemistry of olive trees due to chronic photoinhibition, and this effect is counterbalanced by the addition of OW to the soil. OW reduces herbicide uptake by the plant due to an increase in herbicide adsorption.

  12. Secondary Organic Aerosol Formation from Acetylene (C2H2: seed effect on SOA yields due to organic photochemistry in the aerosol aqueous phase

    Directory of Open Access Journals (Sweden)

    P. J. Ziemann

    2009-03-01

    Full Text Available The lightest Non Methane HydroCarbon (NMHC, i.e., acetylene (C2H2 is found to form secondary organic aerosol (SOA. Contrary to current belief, the number of carbon atoms, n, for a NMHC to act as SOA precursor is lowered to n=2 here. The OH-radical initiated oxidation of C2H2 forms glyoxal (CHOCHO as the highest yield product, and >99% of the SOA from C2H2 is attributed to CHOCHO. SOA formation from C2H2 and CHOCHO was studied in a photochemical and a dark simulation chamber. Further, the experimental conditions were varied with respect to the chemical composition of the seed aerosols, mild acidification with sulphuric acid (SA, 3photochemistry in the liquid water associated with internally mixed inorganic/WSOC seed aerosols is found responsible for this seed effect. WSOC photochemistry enhances the SOA source from CHOCHO, while seeds containing amino acids (AA and/or SA showed among the lowest of all YSOA values, and largely suppress the photochemical enhancement on the rate of CHOCHO uptake. Our results give first evidence for the importance of heterogeneous photochemistry of CHOCHO in SOA formation, and identify a potential bias in the currently available YSOA data for other SOA precursor NMHCs. We demonstrate that SOA formation via the aqueous phase is not limited to cloud droplets, but proceeds also in the absence of clouds, i.e., does not stop once a cloud droplet evaporates. Atmospheric models need to be expanded to include SOA formation from WSOC photochemistry of CHOCHO, and possibly other α-dicarbonyls, in aqueous aerosols.

  13. Sealing devices

    International Nuclear Information System (INIS)

    Coulson, R.A.

    1980-01-01

    A sealing device for minimising the leakage of toxic or radioactive contaminated environments through a biological shield along an opening through which a flexible component moves that penetrates the shield. The sealing device comprises an outer tubular member which extends over a length not less than the maximum longitudinal movement of the component along the opening. An inner sealing block is located intermediate the length of the component by connectors and is positioned in the bore of the outer tubular member to slide in the bore and effect a seal over the entire longitudinal movement of the component. The cross-section of the device may be circular and the block may be of polytetrafluoroethylene or of nylon impregnated with molybdenum or may be metallic. A number of the sealing devices may be combined into an assembly for a plurality of adjacent longitudinally movable components, each adapted to sustain a tensile load, providing the various drives of a master-slave manipulator. (author)

  14. UV-Photochemistry of the Disulfide Bond: Evolution of Early Photoproducts from Picosecond X-ray Absorption Spectroscopy at the Sulfur K-Edge.

    Science.gov (United States)

    Ochmann, Miguel; Hussain, Abid; von Ahnen, Inga; Cordones, Amy A; Hong, Kiryong; Lee, Jae Hyuk; Ma, Rory; Adamczyk, Katrin; Kim, Tae Kyu; Schoenlein, Robert W; Vendrell, Oriol; Huse, Nils

    2018-05-30

    We have investigated dimethyl disulfide as the basic moiety for understanding the photochemistry of disulfide bonds, which are central to a broad range of biochemical processes. Picosecond time-resolved X-ray absorption spectroscopy at the sulfur K-edge provides unique element-specific insight into the photochemistry of the disulfide bond initiated by 267 nm femtosecond pulses. We observe a broad but distinct transient induced absorption spectrum which recovers on at least two time scales in the nanosecond range. We employed RASSCF electronic structure calculations to simulate the sulfur-1s transitions of multiple possible chemical species, and identified the methylthiyl and methylperthiyl radicals as the primary reaction products. In addition, we identify disulfur and the CH 2 S thione as the secondary reaction products of the perthiyl radical that are most likely to explain the observed spectral and kinetic signatures of our experiment. Our study underscores the importance of elemental specificity and the potential of time-resolved X-ray spectroscopy to identify short-lived reaction products in complex reaction schemes that underlie the rich photochemistry of disulfide systems.

  15. CHEM2D-OPP: A new linearized gas-phase ozone photochemistry parameterization for high-altitude NWP and climate models

    Directory of Open Access Journals (Sweden)

    J. P. McCormack

    2006-01-01

    Full Text Available The new CHEM2D-Ozone Photochemistry Parameterization (CHEM2D-OPP for high-altitude numerical weather prediction (NWP systems and climate models specifies the net ozone photochemical tendency and its sensitivity to changes in ozone mixing ratio, temperature and overhead ozone column based on calculations from the CHEM2D interactive middle atmospheric photochemical transport model. We evaluate CHEM2D-OPP performance using both short-term (6-day and long-term (1-year stratospheric ozone simulations with the prototype high-altitude NOGAPS-ALPHA forecast model. An inter-comparison of NOGAPS-ALPHA 6-day ozone hindcasts for 7 February 2005 with ozone photochemistry parameterizations currently used in operational NWP systems shows that CHEM2D-OPP yields the best overall agreement with both individual Aura Microwave Limb Sounder ozone profile measurements and independent hemispheric (10°–90° N ozone analysis fields. A 1-year free-running NOGAPS-ALPHA simulation using CHEM2D-OPP produces a realistic seasonal cycle in zonal mean ozone throughout the stratosphere. We find that the combination of a model cold temperature bias at high latitudes in winter and a warm bias in the CHEM2D-OPP temperature climatology can degrade the performance of the linearized ozone photochemistry parameterization over seasonal time scales despite the fact that the parameterized temperature dependence is weak in these regions.

  16. Ferroelectric devices

    CERN Document Server

    Uchino, Kenji

    2009-01-01

    Updating its bestselling predecessor, Ferroelectric Devices, Second Edition assesses the last decade of developments-and setbacks-in the commercialization of ferroelectricity. Field pioneer and esteemed author Uchino provides insight into why this relatively nascent and interdisciplinary process has failed so far without a systematic accumulation of fundamental knowledge regarding materials and device development.Filling the informational void, this collection of information reviews state-of-the-art research and development trends reflecting nano and optical technologies, environmental regulat

  17. Photochemistry of polycyclic aromatic hydrocarbons in cosmic water ice. II. Near UV/VIS spectroscopy and ionization rates

    Science.gov (United States)

    Bouwman, J.; Cuppen, H. M.; Steglich, M.; Allamandola, L. J.; Linnartz, H.

    2011-05-01

    Context. Mid-infrared emission features originating from polycyclic aromatic hydrocarbons (PAHs) are observed towards photon dominated regions in space. Towards dense clouds, however, these emission features are quenched. Observations of dense clouds show that many simple volatile molecules are frozen out on interstellar grains, forming thin layers of ice. Recently, observations have shown that more complex non-volatile species, presumably including PAHs, also freeze out and contribute to the ongoing solid-state chemistry. Aims: The study presented here aims at obtaining reaction rate data that characterize PAH photochemistry upon vacuum ultraviolet (VUV) irradiation in an interstellar H2O ice analogue to explore the potential impact of PAH:H2O ice reactions on overall interstellar ice chemistry. To this end, the experimental results are implemented in a chemical model under simple interstellar cloud conditions. Methods: Time-dependent near-UV/VIS spectroscopy on the VUV photochemistry of anthracene, pyrene, benzo[ghi]perylene and coronene containing interstellar H2O ice analogs is performed at 25 and 125 K, using an optical absorption setup. Results: Near-UV/VIS absorption spectra are presented for these four PAHs and their photoproducts including cationic species trapped in H2O ice. Oscillator strengths of the cation absorption bands are derived relative to the oscillator strength of the neutral parent PAH. The loss of the parent and growth of PAH photoproducts are measured as a function of VUV dose, yielding solid state reaction constants. The rate constants are used in an exploratory astrochemical model, to assess the importance of PAH:H2O ice photoprocessing in UV exposed interstellar environments, compared with the timescales in which PAH molecules are incorporated in interstellar ices. Conclusions: All four PAHs studied here are found to be readily ionized upon VUV photolysis when trapped in H2O ice and exhibit similar rates for ionization at astronomically

  18. Ancillary Ligand Effects upon the Photochemistry of Mn(bpy)(CO)3X Complexes (X = Br-, PhCC-).

    Science.gov (United States)

    Yempally, Veeranna; Moncho, Salvador; Hasanayn, Faraj; Fan, Wai Yip; Brothers, Edward N; Bengali, Ashfaq A

    2017-09-18

    The photochemistry of two Mn(bpy)(CO) 3 X complexes (X = PhCC - , Br - ) has been studied in the coordinating solvents THF (terahydrofuran) and MeCN (acetonitrile) employing time-resolved infrared spectroscopy. The two complexes are found to exhibit strikingly different photoreactivities and solvent dependencies. In MeCN, photolysis of 1-(CO)(Br) [1 = Mn(bpy)(CO) 2 ] affords the ionic complex [1-(MeCN) 2 ]Br as a final product. In contrast, photolysis of 1-(CO)(CCPh) in MeCN results in facial to meridional isomerization of the parent complex. When THF is used as solvent, photolysis results in facial to meridional isomerization in both complexes, though the isomerization rate is larger for X = Br - . Pronounced differences are also observed in the photosubstitution chemistry of the two complexes where both the rate of MeCN exchange from 1-(MeCN)(X) by THFA (tetrahydrofurfurylamine) and the nature of the intermediates generated in the reaction are dependent upon X. DFT calculations are used to support analysis of some of the experiments.

  19. Photosystem II Photochemistry and Phycobiliprotein of the Red Algae Kappaphycus alvarezii and Their Implications for Light Adaptation

    Directory of Open Access Journals (Sweden)

    Xiangyu Guan

    2013-01-01

    Full Text Available Photosystem II photochemistry and phycobiliprotein (PBP genes of red algae Kappaphycus alvarezii, raw material of κ-carrageenan used in food and pharmaceutical industries, were analyzed in this study. Minimum saturating irradiance (Ik of this algal species was less than 115 μmol m−2 s−1. Its actual PSII efficiency (yield II increased when light intensity enhanced and decreased when light intensity reached 200 μmol m−2 s−1. Under dim light, yield II declined at first and then increased on the fourth day. Under high light, yield II retained a stable value. These results indicate that K. alvarezii is a low-light-adapted species but possesses regulative mechanisms in response to both excessive and deficient light. Based on the PBP gene sequences, K. alvarezii, together with other red algae, assembled faster and showed a closer relationship with LL-Prochlorococcus compared to HL-Prochlorococcus. Many amino acid loci in PBP sequences of K. alvarezii were conserved with those of LL-Prochlorococcus. However, loci conserved with HL-Prochlorococcus but divergent with LL-Prochlorococcus were also found. The diversities of PE and PC are proposed to have played some roles during the algal evolution and divergence of light adaption.

  20. Photosystem II photochemistry and phycobiliprotein of the red algae Kappaphycus alvarezii and their implications for light adaptation.

    Science.gov (United States)

    Guan, Xiangyu; Wang, Jinfeng; Zhu, Jianyi; Yao, Chunyan; Liu, Jianguo; Qin, Song; Jiang, Peng

    2013-01-01

    Photosystem II photochemistry and phycobiliprotein (PBP) genes of red algae Kappaphycus alvarezii, raw material of κ -carrageenan used in food and pharmaceutical industries, were analyzed in this study. Minimum saturating irradiance (I k) of this algal species was less than 115 μmol m(-2) s(-1). Its actual PSII efficiency (yield II) increased when light intensity enhanced and decreased when light intensity reached 200 μmol m(-2) s(-1). Under dim light, yield II declined at first and then increased on the fourth day. Under high light, yield II retained a stable value. These results indicate that K. alvarezii is a low-light-adapted species but possesses regulative mechanisms in response to both excessive and deficient light. Based on the PBP gene sequences, K. alvarezii, together with other red algae, assembled faster and showed a closer relationship with LL-Prochlorococcus compared to HL-Prochlorococcus. Many amino acid loci in PBP sequences of K. alvarezii were conserved with those of LL-Prochlorococcus. However, loci conserved with HL-Prochlorococcus but divergent with LL-Prochlorococcus were also found. The diversities of PE and PC are proposed to have played some roles during the algal evolution and divergence of light adaption.

  1. New insights into the aquatic photochemistry of fluoroquinolone antibiotics: Direct photodegradation, hydroxyl-radical oxidation, and antibacterial activity changes.

    Science.gov (United States)

    Ge, Linke; Na, Guangshui; Zhang, Siyu; Li, Kai; Zhang, Peng; Ren, Honglei; Yao, Ziwei

    2015-09-15

    The ubiquity and photoreactivity of fluoroquinolone antibiotics (FQs) in surface waters urge new insights into their aqueous photochemical behavior. This study concerns the photochemistry of 6 FQs: ciprofloxacin, danofloxacin, levofloxacin, sarafloxacin, difloxacin and enrofloxacin. Methods were developed to calculate their solar direct photodegradation half-lives (td,E) and hydroxyl-radical oxidation half-lives (tOH,E) in sunlit surface waters. The td,E values range from 0.56 min to 28.8 min at 45° N latitude, whereas tOH,E ranges from 3.24h to 33.6h, suggesting that most FQs tend to undergo fast direct photolysis rather than hydroxyl-radical oxidation in surface waters. However, a case study for levofloxacin and sarafloxacin indicated that the hydroxyl-radical oxidation induced risky photochlorination and resulted in multi-degradation pathways, such as piperazinyl hydroxylation and clearage. Changes in the antibacterial activity of FQs caused by photodegradation in various waters were further examined using Escherichia coli, and it was found that the activity evolution depended on primary photodegradation pathways and products. Primary intermediates with intact FQ nuclei retained significant antibacterial activity. These results are important for assessing the fate and risk of FQs in surface waters. Copyright © 2015. Published by Elsevier B.V.

  2. Synthesis of Superparamagnetic Iron Oxide Nanoparticles Modified with MPEG-PEI via Photochemistry as New MRI Contrast Agent

    Directory of Open Access Journals (Sweden)

    Yancong Zhang

    2015-01-01

    Full Text Available Novel method for synthesis of superparamagnetic iron oxide nanoparticles (SPIONs coated with polyethylenimine (PEI and modified with poly(ethylene glycol methyl ether (MPEG, MPEG-PEI-SPIONs, was developed. PEI-SPIONs were successfully prepared in aqueous system via photochemistry, and their surface was modified with poly(ethylene glycol methyl ether (MPEG. The so-obtained MPEG-PEI-SPIONs had a uniform hydrodynamic particle size of 34 nm. The successful coating of MPEG-PEI on the SPIONs was ascertained from FT-IR analysis, and the PEI and MPEG fractions in MPEG-PEI-SPIONs were calculated to account for 31% and 12%, respectively. Magnetic measurement revealed that the saturated magnetization of MPEG-PEI-SPIONs reached 46 emu/g and the nanoparticles showed the characteristic of being superparamagnetic. The stability experiment revealed that the MPEG-PEI modification improved the nanoparticles stability greatly. T2 relaxation measurements showed that MPEG-PEI-SPIONs show similar R2 value to the PEI-SPIONs. The T2-weighted magnetic resonance imaging (MRI of MPEG-PEI-SPIONs showed that the magnetic resonance signal was enhanced significantly with increasing nanoparticle concentration in water. These results indicated that the MPEG-PEI-SPIONs had great potential for application in MRI.

  3. Guide device

    International Nuclear Information System (INIS)

    Brammer, C.M. Jr.

    1977-01-01

    Disclosed is a fuel handling guide tube centering device for use in nuclear reactors during fuel assembly handling operations. The device comprises an outer ring secured to the flange of a nuclear reactor pressure vessel, a rotatable table rotatably coupled to the outer ring, and a plurality of openings through the table. Truncated locating cones are positioned in each of the openings in the table, and the locating cones center the guide tube during fuel handling operations. The openings in the table are located such that each fuel assembly in the nuclear core may be aligned with one of the openings by a suitable rotation of the table. The locating cones thereby provide alignment between the fuel handling mechanism located in the guide tube and the individual fuel assemblies of the cone. The need for a device to provide alignment is especially critical for floating nuclear power plants, where wave motion may exist during fuel handling operations. 5 claims, 4 figures

  4. Medical Devices

    NARCIS (Netherlands)

    Verkerke, Gijsbertus Jacob; Mahieu, H.F.; Geertsema, A.A.; Hermann, I.F.; van Horn, J.R.; Hummel, J. Marjan; van Loon, J.P.; Mihaylov, D.; van der Plaats, A.; Schraffordt Koops, H.; Schutte, H.K.; Veth, R.P.H.; de Vries, M.P.; Rakhorst, G.; Shi, Donglu

    2004-01-01

    The development of new medical devices is a very time-consuming and costly process. Besides the time between the initial idea and the time that manufacturing and testing of prototypes takes place, the time needed for the development of production facilities, production of test series, marketing,

  5. Electrochemical device

    Science.gov (United States)

    Grimes, Patrick G.; Einstein, Harry; Bellows, Richard J.

    1988-01-12

    A tunnel protected electrochemical device features channels fluidically communicating between manifold, tunnels and cells. The channels are designed to provide the most efficient use of auxiliary power. The channels have a greater hydraulic pressure drop and electrical resistance than the manifold. This will provide a design with the optimum auxiliary energy requirements.

  6. Assistive Devices

    Science.gov (United States)

    If you have a disability or injury, you may use a number of assistive devices. These are tools, products or types of equipment that help you perform tasks and activities. They may help you move around, see, communicate, eat, or get ...

  7. Detection device

    Science.gov (United States)

    Smith, J.E.

    1981-02-27

    The present invention is directed to a detection device comprising: (1) an entrance chamber; (2) a central chamber; and (3) an exit chamber. The central chamber includes an ionizing gas, anode, and means for connecting the anode with an external power supply and pulse counter.

  8. Cooling device in thermonuclear device

    International Nuclear Information System (INIS)

    Honda, Tsutomu.

    1988-01-01

    Purpose: To prevent loss of cooling effect over the entire torus structure directly after accidental toubles in a cooling device of a thermonuclear device. Constitution: Coolant recycling means of a cooling device comprises two systems, which are alternately connected with in-flow pipeways and exit pipeways of adjacent modules. The modules are cooled by way of the in-flow pipeways and the exist pipeways connected to the respective modules by means of the coolant recycling means corresponding to the respective modules. So long as one of the coolant recycling means is kept operative, since every one other modules of the torus structure is still kept cooled, the heat generated from the module put therebetween, for which the coolant recycling is interrupted, is removed by means of heat conduction or radiation from the module for which the cooling is kept continued. No back-up emergency cooling system is required and it can provide high economic reliability. (Kamimura, M.)

  9. Solid state photochemistry. Subpanel A-2(b): Metastability in hydrogenated amorphous silicon

    Energy Technology Data Exchange (ETDEWEB)

    Carlson, D. [Solarex Corporation, Newton, PA (United States)

    1996-09-01

    All device quality amorphous silicon based materials exhibit degradation in electronic properties when exposed to sunlight. The photo-induced defects are associated with Si dangling bonds that are created by the recombination and/or trapping of photogenerated carriers. The defects are metastable and can be annealed out at temperatures of about 150 to 200 degrees Centigrade. The density of metastable defects is larger in films that are contaminated with > 10{sup 19} per cubic cm of impurities such as oxygen, carbon and nitrogen. However, recent experimental results indicate that some metastable defects are still present in films with very low impurity concentrations. The photo-induced defects typically saturate after 100 to 1000 hours of exposure to one sun illumination depending on the deposition conditions. There is also experimental evidence that photo-induced structural changes are occurring in the amorphous silicon based materials and that hydrogen may be playing an important role in both the photo-induced structural changes and in the creation of metastable defects.

  10. Thermonuclear device

    International Nuclear Information System (INIS)

    Tezuka, Masaru.

    1993-01-01

    Protrusions and recesses are formed to a vacuum vessel and toroidal magnetic coils, and they are engaged. Since the vacuum vessel is generally supported firmly by a rack or the like by support legs, the toroidal magnetic field coils can be certainly supported against tumbling force. Then, there can be attained strong supports for the toroidal magnetic field coils, in addition to support by wedges on the side of inboard and support by share panels on the side of outboard, capable of withstanding great electromagnetic forces which may occur in large-scaled next-generation devices. That is, toroidal magnetic field coils excellent from a view point of deformation and stress can be obtained, to provide a thermonuclear device of higher reliability. (N.H.)

  11. Thermonuclear device

    International Nuclear Information System (INIS)

    Oosaki, Osamu; Masuda, Kenju.

    1980-01-01

    Purpose: To provide excellent electric properties and high reliability in a thermonuclear device by improving a current collecting board connected to a coil device. Constitution: A current collecting board element perforated with an opening for enserting a connecting terminal is sized to be inserted into a plating tank, and is surface treated in the plating tank. Only the current collecting board element preferably surface treated is picked up. A plurality of such current collecting board elements are connected and welded to form a large current collecting board. In this manner, the current collecting board having several m 2 to several ten order m 2 in area can be obtained as preferably surface treated at the connecting terminal hole. The current collecting board element can be determined in shape with the existing facility without increasing the size of a surface treating tank. (Kamimura, M.)

  12. Thermonuclear device

    International Nuclear Information System (INIS)

    Yagi, Yasuomi; Takahashi, Ken; Hashimoto, Hiroshi.

    1984-01-01

    Purpose: To improve the plasma confining performances by bringing the irregular magnetic fields nearly to zero and decreasing the absolute value of the irregular magnetic fields at every positions. Constitution: The winding direction of a plurality of coil elements, for instance, double pan cake coils of toroidal coils in a torus type or mirror type thermonuclear device are reversed to each other in their laminating direction, whereby the irregular magnetic fields due to the coil-stepped portions in each toroidal coils are brought nearly to zero. This enables to bring the average irregular magnetic fields as a whole in the thermonuclear device nearly to zero, as well as, decrease the absolute value of the irregular magnetic fields in each positions. Thus, the plasma confining performances can be improved. (Moriyama, K.)

  13. "Distinvar" device

    CERN Multimedia

    CERN PhotoLab

    1965-01-01

    The alignment of one of the accelerator magnets being checked by the AR Division survey group. A "distinvar" device, invented by the group, using calibrated invar wires stretched between the fixed survey pillar (on the left) and a fixed point on the magnet. In two days it is thus possible to measure the alignment of the 100 magnets with an accuracy better than 1/10.

  14. Latching device

    Science.gov (United States)

    Ulrich, G. W. (Inventor)

    1975-01-01

    A latching device is suited for use in establishing a substantially motionless connection between a stationary receiver and a movable latching mechanism. The latching mechanism includes a pivotally supported restraining hook continuously urged into a capturing relationship with the receiver, characterized by a spring-biased pawl having a plurality of aligned teeth. The teeth are seated in the surface of the throat of the hook and positionable into restraining engagement with a rigid restraining shoulder projected from the receiver.

  15. Non-adiabatic Excited State Molecule Dynamics Modeling of Photochemistry and Photophysics of Materials

    Energy Technology Data Exchange (ETDEWEB)

    Nelson, Tammie Renee [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Tretiak, Sergei [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-01-06

    Understanding and controlling excited state dynamics lies at the heart of all our efforts to design photoactive materials with desired functionality. This tailor-design approach has become the standard for many technological applications (e.g., solar energy harvesting) including the design of organic conjugated electronic materials with applications in photovoltaic and light-emitting devices. Over the years, our team has developed efficient LANL-based codes to model the relevant photophysical processes following photoexcitation (spatial energy transfer, excitation localization/delocalization, and/or charge separation). The developed approach allows the non-radiative relaxation to be followed on up to ~10 ps timescales for large realistic molecules (hundreds of atoms in size) in the realistic solvent dielectric environment. The Collective Electronic Oscillator (CEO) code is used to compute electronic excited states, and the Non-adiabatic Excited State Molecular Dynamics (NA-ESMD) code is used to follow the non-adiabatic dynamics on multiple coupled Born-Oppenheimer potential energy surfaces. Our preliminary NA-ESMD simulations have revealed key photoinduced mechanisms controlling competing interactions and relaxation pathways in complex materials, including organic conjugated polymer materials, and have provided a detailed understanding of photochemical products and intermediates and the internal conversion process during the initiation of energetic materials. This project will be using LANL-based CEO and NA-ESMD codes to model nonradiative relaxation in organic and energetic materials. The NA-ESMD and CEO codes belong to a class of electronic structure/quantum chemistry codes that require large memory, “long-queue-few-core” distribution of resources in order to make useful progress. The NA-ESMD simulations are trivially parallelizable requiring ~300 processors for up to one week runtime to reach a meaningful restart point.

  16. New insights into the aquatic photochemistry of fluoroquinolone antibiotics: Direct photodegradation, hydroxyl-radical oxidation, and antibacterial activity changes

    Energy Technology Data Exchange (ETDEWEB)

    Ge, Linke; Na, Guangshui [Key Laboratory for Ecological Environment in Coastal Areas (SOA), National Marine Environmental Monitoring Center, Dalian 116023 (China); Zhang, Siyu [Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016 (China); Li, Kai [Key Laboratory for Ecological Environment in Coastal Areas (SOA), National Marine Environmental Monitoring Center, Dalian 116023 (China); Zhang, Peng, E-mail: pzhang@nmemc.org.cn [Key Laboratory for Ecological Environment in Coastal Areas (SOA), National Marine Environmental Monitoring Center, Dalian 116023 (China); Ren, Honglei; Yao, Ziwei [Key Laboratory for Ecological Environment in Coastal Areas (SOA), National Marine Environmental Monitoring Center, Dalian 116023 (China)

    2015-09-15

    The ubiquity and photoreactivity of fluoroquinolone antibiotics (FQs) in surface waters urge new insights into their aqueous photochemical behavior. This study concerns the photochemistry of 6 FQs: ciprofloxacin, danofloxacin, levofloxacin, sarafloxacin, difloxacin and enrofloxacin. Methods were developed to calculate their solar direct photodegradation half-lives (t{sub d,E}) and hydroxyl-radical oxidation half-lives (t{sub ·OH,E}) in sunlit surface waters. The t{sub d,E} values range from 0.56 min to 28.8 min at 45° N latitude, whereas t{sub ·OH,E} ranges from 3.24 h to 33.6 h, suggesting that most FQs tend to undergo fast direct photolysis rather than hydroxyl-radical oxidation in surface waters. However, a case study for levofloxacin and sarafloxacin indicated that the hydroxyl-radical oxidation induced risky photochlorination and resulted in multi-degradation pathways, such as piperazinyl hydroxylation and clearage. Changes in the antibacterial activity of FQs caused by photodegradation in various waters were further examined using Escherichia coli, and it was found that the activity evolution depended on primary photodegradation pathways and products. Primary intermediates with intact FQ nuclei retained significant antibacterial activity. These results are important for assessing the fate and risk of FQs in surface waters. - Highlights: • It is first reported on hydroxyl-radical oxidation of 6 fluoroquinolone antibiotics. • Methods were developed to assess photolysis and oxidation fate in surface waters. • The neutral form reacted faster with hydroxyl radical than protonated forms. • The main oxidation intermediates and transformation pathways were clarified. • The antibacterial activity changes depend on dominant photolysis pathways.

  17. New insights into the aquatic photochemistry of fluoroquinolone antibiotics: Direct photodegradation, hydroxyl-radical oxidation, and antibacterial activity changes

    International Nuclear Information System (INIS)

    Ge, Linke; Na, Guangshui; Zhang, Siyu; Li, Kai; Zhang, Peng; Ren, Honglei; Yao, Ziwei

    2015-01-01

    The ubiquity and photoreactivity of fluoroquinolone antibiotics (FQs) in surface waters urge new insights into their aqueous photochemical behavior. This study concerns the photochemistry of 6 FQs: ciprofloxacin, danofloxacin, levofloxacin, sarafloxacin, difloxacin and enrofloxacin. Methods were developed to calculate their solar direct photodegradation half-lives (t d,E ) and hydroxyl-radical oxidation half-lives (t ·OH,E ) in sunlit surface waters. The t d,E values range from 0.56 min to 28.8 min at 45° N latitude, whereas t ·OH,E ranges from 3.24 h to 33.6 h, suggesting that most FQs tend to undergo fast direct photolysis rather than hydroxyl-radical oxidation in surface waters. However, a case study for levofloxacin and sarafloxacin indicated that the hydroxyl-radical oxidation induced risky photochlorination and resulted in multi-degradation pathways, such as piperazinyl hydroxylation and clearage. Changes in the antibacterial activity of FQs caused by photodegradation in various waters were further examined using Escherichia coli, and it was found that the activity evolution depended on primary photodegradation pathways and products. Primary intermediates with intact FQ nuclei retained significant antibacterial activity. These results are important for assessing the fate and risk of FQs in surface waters. - Highlights: • It is first reported on hydroxyl-radical oxidation of 6 fluoroquinolone antibiotics. • Methods were developed to assess photolysis and oxidation fate in surface waters. • The neutral form reacted faster with hydroxyl radical than protonated forms. • The main oxidation intermediates and transformation pathways were clarified. • The antibacterial activity changes depend on dominant photolysis pathways

  18. Damping device

    International Nuclear Information System (INIS)

    Banks, E.L. Jr.; Dowell, T.P.

    1976-01-01

    The description is given of a damper which includes a pair of telescopic components interconnected by relative linear movement one in relation to the other, by a screw and ball nut device, with a braking surface on one of the components, a brake engaging the braking surface, an inertia mass entrained by the other components, non-deformable and distinct brake actuating gear, independently mobile in relation to the other braking system and fixed and controlled by the inertia mass, positively to engage the braking surface. This damper is for retaining the parts of a nuclear power station so that can withstand earthquakes [fr

  19. Thermonuclear device

    International Nuclear Information System (INIS)

    Inoue, Toyokazu; Murata, Toru.

    1983-01-01

    Purpose: To shield superconducting coils for use in the generation of magnetic field against neutron irradiation thereby preventing tritium contamination. Constitution: The thermonuclear device comprises, in its inside, a vacuum container for containing plasmas, superconducting coils disposed to the outside of the vacuum container and neutron absorbers disposed between the super-conducting coils and the vacuum container. since neutrons issued from the plasma are absorbed by neutron absorbers and not irradiated to the superconducting coils, generation of tritium due to the reaction between 3 He in the liquid helium as the coolants for the super-conducting coils and the neutrons is prevented. (Aizawa, K.)

  20. Strainer device

    International Nuclear Information System (INIS)

    Mokuya, Kenji.

    1975-01-01

    Object: To provide a strainer device, which is adapted to facilitate flushing and is particularly suited for installation in the cooling system of a liquid metal cooled fast breeding reactor. Structure: A casing accommodating a strainer and a blind plate for the selection of a flow path is provided at a suitable portion of the duct line. The blind plate is adapted to be rotated by an opening and closing means consisting of a rod. bellows, shaft and so forth. At the time of flushing, the duct line is sealed by the blind plate. (Nakamura, S.)

  1. Scalable devices

    KAUST Repository

    Krüger, Jens J.

    2014-01-01

    In computer science in general and in particular the field of high performance computing and supercomputing the term scalable plays an important role. It indicates that a piece of hardware, a concept, an algorithm, or an entire system scales with the size of the problem, i.e., it can not only be used in a very specific setting but it\\'s applicable for a wide range of problems. From small scenarios to possibly very large settings. In this spirit, there exist a number of fixed areas of research on scalability. There are works on scalable algorithms, scalable architectures but what are scalable devices? In the context of this chapter, we are interested in a whole range of display devices, ranging from small scale hardware such as tablet computers, pads, smart-phones etc. up to large tiled display walls. What interests us mostly is not so much the hardware setup but mostly the visualization algorithms behind these display systems that scale from your average smart phone up to the largest gigapixel display walls.

  2. Thermonuclear device

    International Nuclear Information System (INIS)

    Honda, Takuro; Maki, Koichi.

    1997-01-01

    The present invention provides a thermonuclear device, in which integrity of a measuring device is kept, the reactor wall temperature and wear of armour materials are monitored accurately even under intense radiation rays, so that the flow rate of coolants and plasma power can be controlled by using the signals. Infrared rays generated from the surface of the armour materials disposed on a first wall are detected to measure the reactor wall temperature. Coolant flow rate and plasma power are controlled based on the obtained reactor wall temperature. In addition, infrared rays generated from the back of the armour materials are detected to obtain the surface temperature in order to avoid intense radiation rays from plasmas. The coolant flow rate and the plasma power are controlled based on the obtained temperature on the surface of the reactor thereby controlling the temperature of the first wall and the armour material to 300degC or lower in a case of the first wall made of stainless steel and 1000degC or lower in a case of the armour material made of graphite. (I.S.)

  3. Thermonuclear device

    International Nuclear Information System (INIS)

    Kuriyama, Masaaki; Yamamoto, Masahiro; Furuyama, Masayuki; Saito, Ryusei.

    1981-01-01

    Purpose: To enable the efficient and rapid cooling of a vacuum vessel by cooling with gas when the temperature of the vacuum vessel is higher than the boiling point of water and cooling with water when the temperature is lower than the boiling point of water. Constitution: A cooling pipe is provided through an insulating pipe on the outer periphery of a vacuum vessel. The cooling pipe communicates through a cooling gas valve and a coolant valve with a cooling gas supply device and a coolant supply device, and a heat exchanger is disposed at the pipe. When the vessel is higher than the boiling point of the coolant the coolant valve is closed and the cooling gas valve is opened and gas is supplied to cool the vessel. The gas is recoverd through a heat exchanger. On the other hand, when the temperature of vessel is lower than the boiling point of the coolant, the gas valve is closed, the coolant valve is opened, and the vessel is cooled with coolant. The vacuum vessel can be cooled for short time employing both the gas and the coolant together. (Yoshino, Y.)

  4. Thermonuclear device

    International Nuclear Information System (INIS)

    Takano, Hirohisa; Nakamoto, Kazunari; Hanai, Satoshi.

    1984-01-01

    Purpose: To provide coils of high mechanical strength for use at the center of a torus type thermonuclear device. Constitution: A plurality of copper plates having cooling holes and bolt holes and insulation paper sheets of the same shape are prepared. The copper plate is different from the insulation paper sheet only in that the position-phase angle of the opening portion is larger by 15 - 30 0 . The copper plates and the insulation paper sheets are alternately stacked by a required number of turns while displacing the angle, and then clamped by bolts to form a mechanically strong coil with no metallurgical joining. Further, since the insulation paper sheets are not present in the radial direction and only one insulation paper sheet is inserted for each turn in the direction of the coil height, the space occupied by the coil can be decreased. According to this invention, the magnetic flux density at the center of the device can be increased as compared with the conventional case to thereby apply a higher voltage on the side of plasmas. (Moriyama, K.)

  5. Irradiation device

    International Nuclear Information System (INIS)

    Suzuki, Toshimitsu.

    1989-01-01

    In an irradiation device for irradiating radiation rays such as electron beams to pharmaceuticals, etc., since the distribution of scanned electron rays was not monitored, the electron beam intensity could be determined only indirectly and irradiation reliability was not satisfactory. In view of the above, a plurality of monitor wires emitting secondary electrons are disposed in the scanning direction near a beam take-out window of a scanning duct, signals from the monitor wires are inputted into a display device such as a cathode ray tube, as well as signals from the monitor wires at the central portion are inputted into counting rate meters to measure the radiation dose as well. Since secondary electrons are emitted when electron beams pass through the monitor wires and the intensity thereof is in proportion with the intensity of incident electron beams, the distribution of the radiation dose can be monitored by measuring the intensity of the emitted secondary electrons. Further, uneven irradiation, etc. can also be monitored to make the radiation of irradiation rays reliable. (N.H.)

  6. Practical microwave electron devices

    CERN Document Server

    Meurant, Gerard

    2013-01-01

    Practical Microwave Electron Devices provides an understanding of microwave electron devices and their applications. All areas of microwave electron devices are covered. These include microwave solid-state devices, including popular microwave transistors and both passive and active diodes; quantum electron devices; thermionic devices (including relativistic thermionic devices); and ferrimagnetic electron devices. The design of each of these devices is discussed as well as their applications, including oscillation, amplification, switching, modulation, demodulation, and parametric interactions.

  7. Thermonuclear device

    International Nuclear Information System (INIS)

    Furuyama, Masayuki.

    1979-01-01

    Purpose: To provide the subject device wherein a conductive short-circuiting ring is installed in the vicinity of the bonded part of bellows and thick portion of vacuum vessel in the small circumferential direction of torus, thereby to reduce the electromagnetic force generated at the bellows. Constitution: A conductive short-circuiting ring is provided in the vicinity of the connected part of a thick portion and bellows portion. By this organization, a saddle type current generated at the thick portion by a vertical magnetic field flows through the short-circuiting ring because the resistance at a part where the short-circuiting ring is provided is reduced, and the current flowing through the bellows is remarkably reduced. For this reason, the electromagnetic force generated at the bellows is reduced thereby to prevent the bellows from being destroyed by the electromagnetic force. (Yoshihara, H.)

  8. Electrophoresis device

    Science.gov (United States)

    Rhodes, P. H.; Snyder, R. S. (Inventor)

    1982-01-01

    A device for separating cellular particles of a sample substance into fractionated streams of different cellular species includes a casing having a distribution chamber, a separation chamber, and a collection chamber. The electrode chambers are separated from the separation chamber interior by means of passages such that flow variations and membrane variations around the slotted portion of the electrode chamber do not enduce flow perturbations into the laminar buffer curtain flowing in the separation chamber. The cellular particles of the sample are separated under the influence of the electrical field and the separation chamber into streams of different cellular species. The streams of separated cells enter a partition array in the collection chamber where they are fractionated and collected.

  9. Thermonuclear device

    International Nuclear Information System (INIS)

    Suzuki, Shohei

    1988-01-01

    Purpose: To obtain high voltage withstanding current introduction terminals not suffering from the effects of the reduction in the creeping voltage withstanding property by the application of magnetic fields. Constitution: This invention concerns a current introduction terminal for supplying electric current to coils for use in a thermonuclear device, etc. The conductor of the current introduction terminal on the side of vacuum is completely covered with solid insulator. This can eliminate the portion of securing the creeping withstanding voltage. The voltage withstanding characteristics of the solid insulator covering the portion of the conductor on the side of vacuum has a constant value irrespective of the atmosphere or the absence or presence of magnetic fields. Accordingly, the voltage withstanding characteristics of the current introduction terminal on the side of vacuum are determined by the property of the solid insulator, which is not reduced by the application of magnetic fields. (Ikeda, J.)

  10. Functionalization of the PEG Corona of Nanoparticles by Clip Photochemistry in Water: Application to the Grafting of RGD Ligands on PEGylated USPIO Imaging Agent.

    Science.gov (United States)

    Pourcelle, Vincent; Laurent, Sophie; Welle, Alexandre; Vriamont, Nicolas; Stanicki, Dimitri; Vander Elst, Luce; Muller, Robert N; Marchand-Brynaert, Jacqueline

    2015-05-20

    The fast development of nanomedicines requires more and more reliable chemical tools in order to accurately design materials and control the surface properties of the nano-objects used in biomedical applications. In this study we describe a smooth and simple photografting technique, i.e., the clip photochemistry, that allows the introduction of molecules of interest in inert polymers or on stealth nanoparticles directly in aqueous solution. First we developed the methodology on polyethylene glycol (PEG) and looked for critical parameters of the process (irradiation times, concentrations, washings) by using several molecular probes and adapted analytical techniques ((19)F qNMR, EA, LSC). We found that the clip photochemistry in water is a robust and efficient method to functionalize PEG. Second we applied it on PEGylated USPIO (USPIO-PEG) magnetic resonance imaging agent and succeeded in introducing RGD peptide and homemade peptidomimetics on their PEG segments. The magnetic abilities of the conjugated nanoparticles were unchanged by the derivatization process as evidenced by their relaxometric properties and their NMRD profile. When tested on Jurkat lymphocyte T Cells, which express αvβ3 integrins, the USPIO conjugated with RGD ligands leads to an increase of the transverse relaxation rate (R2) by a factor 10 to 14 as compared to USPIO-PEG. Consequently, it makes them good candidates for targeted imaging technology in cancer therapy.

  11. Two case studies on the interaction of large-scale transport, mesoscale photochemistry, and boundary-layer processes on the lower tropospheric ozone dynamics in early spring

    Energy Technology Data Exchange (ETDEWEB)

    Broennimann, S.; Siegrist, F.C.; Eugster, W.; Cattin, R.; Sidle, C.; Wanner, H. [Inst. of Geography, Univ. of Bern (Switzerland); Hirschberg, M.M. [Lehrstuhl fuer Bioklimatologie und Immissionsforschung, TU Muenchen, Freising-Weihenstephan (Germany); Schneiter, D. [MeteoSwiss, Station Aerologique, Payerne (Switzerland); Perego, S. [IBM Switzerland, Zuerich (Switzerland)

    2001-04-01

    The vertical distribution of ozone in the lower troposphere over the Swiss Plateau is investigated in detail for two episodes in early spring (February 1998 and March 1999). Profile measurements of boundary-layer ozone performed during two field campaigns with a tethered balloon sounding system and a kite are investigated using regular aerological and ozone soundings from a nearby site, measurements from monitoring stations at various altitudes, backward trajectories, and synoptic analyses of meteorological fields. Additionally, the effect of in situ photochemistry was estimated for one of the episodes employing the Metphomod Eulerian photochemical model. Although the meteorological situations were completely different, both cases had elevated layers with high ozone concentrations, which is not untypical for late winter and early spring. In the February episode, the highest ozone concentrations of 55 to 60 ppb, which were found at around 1100 m asl, were partly advected from Southern France, but a considerable contribution of in situ photochemistry is also predicted by the model. Below that elevation, the local chemical sinks and surface deposition probably overcompensated chemical production, and the vertical ozone distribution was governed by boundary-layer dynamics. In the March episode, the results suggest that ozone-rich air parcels, probably of stratospheric or upper tropospheric origin, were advected aloft the boundary layer on the Swiss Plateau. (orig.)

  12. Two case studies on the interaction of large-scale transport, mesoscale photochemistry, and boundary-layer processes on the lower tropospheric ozone dynamics in early spring

    Directory of Open Access Journals (Sweden)

    S. Brönnimann

    2001-04-01

    Full Text Available The vertical distribution of ozone in the lower troposphere over the Swiss Plateau is investigated in detail for two episodes in early spring (February 1998 and March 1999. Profile measurements of boundary-layer ozone performed during two field campaigns with a tethered balloon sounding system and a kite are investigated using regular aerological and ozone soundings from a nearby site, measurements from monitoring stations at various altitudes, backward trajectories, and synoptic analyses of meteorological fields. Additionally, the effect of in situ photochemistry was estimated for one of the episodes employing the Metphomod Eulerian photochemical model. Although the meteorological situations were completely different, both cases had elevated layers with high ozone concentrations, which is not untypical for late winter and early spring. In the February episode, the highest ozone concentrations of 55 to 60 ppb, which were found at around 1100 m asl, were partly advected from Southern France, but a considerable contribution of in situ photochemistry is also predicted by the model. Below that elevation, the local chemical sinks and surface deposition probably overcompensated chemical production, and the vertical ozone distribution was governed by boundary-layer dynamics. In the March episode, the results suggest that ozone-rich air parcels, probably of stratospheric or upper tropospheric origin, were advected aloft the boundary layer on the Swiss Plateau.Key words. Atmospheric composition and structure (pollution – urban and regional; troposphere – composition and  chemistry – Meteorology and atmospheric dynamics (mesoscale meteorology

  13. Safety device of thermonuclear device

    International Nuclear Information System (INIS)

    Aoki, Isao; Ueda, Shuzo; Seki, Yasushi; Sakurai, Akiko; Kasahara, Fumio; Obara, Atsushi; Yamauchi, Michinori.

    1997-01-01

    The present invention provides a safety device against an event of intrusion of coolants in a vacuum vessel. Namely, a coolant supply system comprises cooling tubes for supplying coolants to main reactor structure components including a vacuum vessel. A detection means detects leakage of coolants in the vacuum vessel. A coolant supply control means controls the supply of coolants to the main reactor structural components based on the leakage detection signals of the detection means. A stagnated material discharging means discharges stagnated materials in the main reactor structural components caused by the leakage of coolants. The leakage of coolants (for example, water) in the vacuum vessel can thus be detected by the water detection device in the vacuum vessel. A control value of a coolant supply means is closed by the leakage detection signals. The supply of coolants to the main reactor structural components is restricted to suppress the leakage. The stagnated materials are discharged to a tank by way of a water draining valve. (I.S.)

  14. Mechanism for the Coupled Photochemistry of Ammonia and Acetylene: Implications for Giant Planets, Comets and Interstellar Organic Synthesis

    Science.gov (United States)

    Keane, Thomas C.

    2017-09-01

    Laboratory studies provide a fundamental understanding of photochemical processes in planetary atmospheres. Photochemical reactions taking place on giant planets like Jupiter and possibly comets and the interstellar medium are the subject of this research. Reaction pathways are proposed for the coupled photochemistry of NH3 (ammonia) and C2H2 (acetylene) within the context Jupiter's atmosphere. We then extend the discussion to the Great Red Spot, Extra-Solar Giant Planets, Comets and Interstellar Organic Synthesis. Reaction rates in the form of quantum yields were measured for the decomposition of reactants and the formation of products and stable intermediates: HCN (hydrogen cyanide), CH3CN (acetonitrile), CH3CH = N-N = CHCH3 (acetaldazine), CH3CH = N-NH2 (acetaldehyde hydrazone), C2H5NH2 (ethylamine), CH3NH2 (methylamine) and C2H4 (ethene) in the photolysis of NH3/C2H2 mixtures. Some of these compounds, formed in our investigation of pathways for HCN synthesis, were not encountered previously in observational, theoretical or laboratory photochemical studies. The quantum yields obtained allowed for the formulation of a reaction mechanism that attempts to explain the observed results under varying experimental conditions. In general, the results of this work are consistent with the initial observations of Ferris and Ishikawa (1988). However, their proposed reaction pathway which centers on the photolysis of CH3CH = N-N = CHCH3 does not explain all of the results obtained in this study. The formation of CH3CH = N-N = CHCH3 by a radical combination reaction of CH3CH = N• was shown in this work to be inconsistent with other experiments where the CH3CH = N• radical is thought to form but where no CH3CH = N-N = CHCH3 was detected. The importance of the role of H atom abstraction reactions was demonstrated and an alternative pathway for CH3CH = N-N = CHCH3 formation involving nucleophilic reaction between N2H4 and CH3CH = NH is advanced.

  15. Mechanism for the Coupled Photochemistry of Ammonia and Acetylene: Implications for Giant Planets, Comets and Interstellar Organic Synthesis.

    Science.gov (United States)

    Keane, Thomas C

    2017-09-01

    Laboratory studies provide a fundamental understanding of photochemical processes in planetary atmospheres. Photochemical reactions taking place on giant planets like Jupiter and possibly comets and the interstellar medium are the subject of this research. Reaction pathways are proposed for the coupled photochemistry of NH 3 (ammonia) and C 2 H 2 (acetylene) within the context Jupiter's atmosphere. We then extend the discussion to the Great Red Spot, Extra-Solar Giant Planets, Comets and Interstellar Organic Synthesis. Reaction rates in the form of quantum yields were measured for the decomposition of reactants and the formation of products and stable intermediates: HCN (hydrogen cyanide), CH 3 CN (acetonitrile), CH 3 CH = N-N = CHCH 3 (acetaldazine), CH 3 CH = N-NH 2 (acetaldehyde hydrazone), C 2 H 5 NH 2 (ethylamine), CH 3 NH 2 (methylamine) and C 2 H 4 (ethene) in the photolysis of NH 3 /C 2 H 2 mixtures. Some of these compounds, formed in our investigation of pathways for HCN synthesis, were not encountered previously in observational, theoretical or laboratory photochemical studies. The quantum yields obtained allowed for the formulation of a reaction mechanism that attempts to explain the observed results under varying experimental conditions. In general, the results of this work are consistent with the initial observations of Ferris and Ishikawa (1988). However, their proposed reaction pathway which centers on the photolysis of CH 3 CH = N-N = CHCH 3 does not explain all of the results obtained in this study. The formation of CH 3 CH = N-N = CHCH 3 by a radical combination reaction of CH 3 CH = N• was shown in this work to be inconsistent with other experiments where the CH 3 CH = N• radical is thought to form but where no CH 3 CH = N-N = CHCH 3 was detected. The importance of the role of H atom abstraction reactions was demonstrated and an alternative pathway for CH 3 CH = N-N = CHCH 3 formation involving nucleophilic reaction

  16. Thermonuclear device

    International Nuclear Information System (INIS)

    Suzuki, Shohei.

    1980-01-01

    Purpose: To improve the plasma confining efficiency in a thermonuclear device having magnet coils using super-conducting wires by decreasing the uneven magnetic field resulted from current supply terminals and wirings. Constitution: Current introduction terminals of magnet coils using superconducting wires are short circuitted with a superconducting short circuit wire. Upon supplying current to the coils, the resistance of the coils is rendered superconductive and the resistance of the short circuit wire is rendered normally conductive heated by a heater and the switch is closed. In this case, most parts of the current are flown through the resistance of the coils and the switch is opened when the current arrives at a predetermined value to render the resistance of the short circuit wire superconductive. Then, the current transfers from the thyristor power source to the resistance of the short circuit wire, whereby the resistance of the coils and that of the short circuit wire from a permanent current loop. In this conditions, since current flows through the short circuit wire and the coils and not to the current introduction terminals, no uniform magnetic field is generated. (Kawakami, Y.)

  17. Reluctance device

    International Nuclear Information System (INIS)

    Claridge, A.N.; Smith, A.J.

    1983-01-01

    A reluctance device comprises two or more phases, each of which has a rotor mounted for rotation within a tubular member and an annular stator positioned externally of the tubular member. The rotor and the internal surface of the tubular member are each provided with aligned, axially spaced apart annular arrays of teeth, the teeth on the rotor confronting those on the tubular member in radially spaced apart relationship. The stator encloses a coil which, when electrically energised, creates a plurality of magnetic flux paths each of which extends radially between the rotor and stator via the confronting teeth and the tubular member, and axially along both the rotor and the portion of the stator located radially outwardly of the coil. The portion of the tubular member intermediate the teeth thereon is provided with a non-magnetic insert in order to resist the axial passage of magnetic flux therethrough. In one of the claims, the tubular member comprises a portion of a nuclear reactor which is adapted to contain a reactor control rod, the rotor constituting a portion of the drive mechanism for the control rod contained in operation within the tubular member. (author)

  18. Protection device for a thermonuclear device

    International Nuclear Information System (INIS)

    Kawashima, Shuichi.

    1986-01-01

    Purpose: To exactly detect the void coefficients of coolants even under high magnetic fields thereby detect the overheat of a thermonuclear device at an early stage. Constitution: The protecting device of this invention comprises a laser beam generation device, a laser beam detection device and an accident detection device. The laser generation device always generates laser beams, which are permeated through coolants and detected by the laser beam detection device, the optical amount of which is transmitted to the accident detection device. The accident detection device judges the excess or insufficiency of the detected optical amount with respect to the optical amount of the laser beams under the stationary state as a reference and issues an accident signal. Since only the optical cables that do not undergo the effect of the magnetic fields are exposed to high magnetic fields in the protection device of this invention, a high reliability can be maintained. (Kamimura, M.)

  19. Recent Advances in Photochemistry

    Indian Academy of Sciences (India)

    Unknown

    The next one was held in Taejon, Korea in 1999. Both the Conferences were highly successful. The third conference APC-2002 was awarded to India and was organized at the Hotel. Centaur, Juhu Beach, Mumbai, during 6–11 January 2002. Nearly 80 invited and 150 poster contributions were presented at the Conference.

  20. Photochemistry of comets

    International Nuclear Information System (INIS)

    Huebner, W.F.

    1985-01-01

    The classification of comets, chemically rich mixtures of volatile materials and refractory grains, is described. The developments of coma and tails, and the composition and structure of coma, plasma tails, dust, and nucleus are examined. The differences between comets and planetary atmospheres are investigated. Three hypotheses on the origin of comets are proposed; one states that comets formed in the region of the giant planets, the second theory has the development of comets occuring in the outer parts of the solar nebula, and the third states that comets formed in a companion fragment of the nebula. The use of radar, photometric, spectral, and laboratory measurements for modeling comets is discussed. The physics and main photolytic and chemical reaction processes of a collision-dominated coma are analyzed; the influence of the solar wind on the coma is studied. A comparison of the model with observed data is presented; good correlation of data is observed. The features of Halley's Comet and other comets with distinctive characteristics are examined. Future comet exploration missions and the need to improve comet models are discussed. 31 references

  1. Photochemistry at Interfaces

    Energy Technology Data Exchange (ETDEWEB)

    Eisenthal, Kenneth B [Columbia Univ., New York, NY (United States)

    2015-02-24

    We have advanced our capabilities to investigate ultrafast excited state dynamics at a liquid interface using a pump to excite molecules to higher electronic states and then probe the subsequent time evolution of the interfacial molecules with femtosecond time delayed vibrational SFG.

  2. High resolution inner-shell spectroscopies of atoms and molecules in gas phase using the soft x-ray photochemistry beamline at SPring-8

    International Nuclear Information System (INIS)

    Ueda, Kiyoshi

    2003-01-01

    This article describes recent activities on inner-shell spectroscopies of atoms and molecules on beamline 27SU, nicknamed soft X-ray photochemistry beamline, at SPring-8, an 8-GeV synchrotron radiation facility in Japan. This beamline provides linearly polarized monochromatic soft X-rays at the resolution higher than 10,000. The end station is designed so that one can perform various kinds of excitation and de-excitation spectroscopies as well as coincidence spectroscopies. Following the description of the beamline and the end station, we present recent results for inner-shell spectroscopies on Ne, CO 2 , BF 3 , and CF 4 . Emphasis is given to illustrate the strategy of the research on this beamline and performance of the beamline and the end station. (author)

  3. Differential acclimation of enzymatic antioxidant metabolism and photosystem II photochemistry in tall fescue under drought and heat and the combined stresses

    Directory of Open Access Journals (Sweden)

    Aoyue eBi

    2016-04-01

    Full Text Available Quality inferiority in cool-season turfgrass due to drought, heat and a combination of both stresses is predicted to be more prevalent in the future. Understanding the various response to heat and drought stress will assist in the selection and breeding of tolerant grass varieties. The objective of this study was to investigate the behavior of antioxidant metabolism and photosystem II (PSII photochemistry in two tall fescue genotypes (PI 234881 and PI 578718 with various thermotolerance capacities. Wide variations were found between heat-tolerant PI 578718 and heat-sensitive PI 234881 for leaf relative water content, malondialdehyde and electrolyte leakage under drought, high-temperature or a combination of both stresses. The sensitivity of PI 234881 exposed to combined stresses was associated with lower superoxide dismutase activity and higher H2O2 accumulation than that in PI 578718. Various antioxidant enzymes displayed positive correlation with chlorophyll content, but negative with membrane injury index at most of the stages in both tall fescue genotypes. The JIP-test analysis in PI 578718 indicated a significant improvement in ABS/RC, TR0/RC, RE0/RC, RE0/ABS values as compared to the control regime, which indicated that PI 578718 had a high potential to protect the PSII system under drought and high temperature stress. And the PS II photochemistry in PI 234881 was damaged significantly compared with PI578718. Moreover, quantitative RT-PCR revealed that heat and drought stresses deduced the gene expression of psbB and psbC, but induced the expression of psbA. These findings to some extent confirmed that the various adaptations of physiological traits may contribute to breeding in cold-season turfgrass in response to drought, high-temperature and a combination of both stresses.

  4. Two case studies on the interaction of large-scale transport, mesoscale photochemistry, and boundary-layer processes on the lower tropospheric ozone dynamics in early spring

    Directory of Open Access Journals (Sweden)

    S. Brönnimann

    Full Text Available The vertical distribution of ozone in the lower troposphere over the Swiss Plateau is investigated in detail for two episodes in early spring (February 1998 and March 1999. Profile measurements of boundary-layer ozone performed during two field campaigns with a tethered balloon sounding system and a kite are investigated using regular aerological and ozone soundings from a nearby site, measurements from monitoring stations at various altitudes, backward trajectories, and synoptic analyses of meteorological fields. Additionally, the effect of in situ photochemistry was estimated for one of the episodes employing the Metphomod Eulerian photochemical model. Although the meteorological situations were completely different, both cases had elevated layers with high ozone concentrations, which is not untypical for late winter and early spring. In the February episode, the highest ozone concentrations of 55 to 60 ppb, which were found at around 1100 m asl, were partly advected from Southern France, but a considerable contribution of in situ photochemistry is also predicted by the model. Below that elevation, the local chemical sinks and surface deposition probably overcompensated chemical production, and the vertical ozone distribution was governed by boundary-layer dynamics. In the March episode, the results suggest that ozone-rich air parcels, probably of stratospheric or upper tropospheric origin, were advected aloft the boundary layer on the Swiss Plateau.

    Key words. Atmospheric composition and structure (pollution – urban and regional; troposphere – composition and  chemistry – Meteorology and atmospheric dynamics (mesoscale meteorology

  5. Constraining the Volatile Composition and Coma Photochemistry in Jupiter Family Comet 41P/Tuttle-Giacobini-Kresak with High Resolution IR and Optical Spectroscopy

    Science.gov (United States)

    McKay, Adam; DiSanti, Michael; Cochran, Anita; Dello Russo, Neil; Bonev, Boncho; Vervack, Ronald; Gibb, Erika; Roth, Nathan; Kawakita, Hideyo

    2018-01-01

    Over the past 20 years optical and IR spectroscopy of cometary comae has expanded our understanding both of cometary volatile composition and coma photochemistry. However, these observations tend to be biased towards Nearly Isotropic Comets (NIC'S) from the Oort Cloud, rather than the generally fainter and less active Jupiter Family Comets (JFC's) that are thought to originate from the Scattered Disk. However, early 2017 provided a rare opportunity to study several JFC's. We present preliminary results from IR and optical spectroscopy of JFC 41P/Tuttle-Giacobini-Kresak obtained during its 2017 apparition. IR spectra were obtained with the NIRSPEC instrument on Keck II and the new iSHELL spectrograph on NASA IRTF. High spectral resolution optical spectra were obtained with the Tull Coude spectrograph on the 2.7-meter Harlan J. Smith Telescope at McDonald Observatory. We will discuss mixing ratios of HCN, NH3, C2H6, C2H2, H2CO, and CH3OH compared to H2O and compare these to previous observations of comets. Preliminary results from the NIRSPEC observations indicate that 41P has typical C2H2 and HCN abundances compared to other JFC's, while the C2H6 abundance is similar to that of NIC's, but is enriched compared to other JFC's. H2CO appears to be heavily depleted in 41P. Analysis of the iSHELL spectra is underway and we will include results from these observations, which complement those from NIRSPEC and extend the scope or our compositional study by measuring additional molecules. We will also present abundances for CN, C2, NH2, C3, and CH obtained from the optical spectra and discuss the implications for the coma photochemistry.This work is supported by the NASA Postdoctoral Program, administered by the Universities Space Research Association, with additional funding from the NSF and NASA PAST.

  6. Medical Device Safety

    Science.gov (United States)

    A medical device is any product used to diagnose, cure, or treat a condition, or to prevent disease. They ... may need one in a hospital. To use medical devices safely Know how your device works. Keep ...

  7. Implantable electronic medical devices

    CERN Document Server

    Fitzpatrick, Dennis

    2014-01-01

    Implantable Electronic Medical Devices provides a thorough review of the application of implantable devices, illustrating the techniques currently being used together with overviews of the latest commercially available medical devices. This book provides an overview of the design of medical devices and is a reference on existing medical devices. The book groups devices with similar functionality into distinct chapters, looking at the latest design ideas and techniques in each area, including retinal implants, glucose biosensors, cochlear implants, pacemakers, electrical stimulation t

  8. Hip supporting device

    DEFF Research Database (Denmark)

    2011-01-01

    The present invention relates to a device for limiting movements in one or more anatomical joints, such as a device for limiting movement in the human hip joint after hip replacement surgery. This is provided by a device for limiting movement in the human hip joint, said device comprising: at least...

  9. FLUIDICS DEVICE FOR ASSAY

    DEFF Research Database (Denmark)

    2007-01-01

    The present invention relates to a device for use in performing assays on standard laboratory solid supports whereon chemical entities are attached. The invention furthermore relates to the use of such a device and a kit comprising such a device. The device according to the present invention is a...

  10. Power source device for thermonuclear device

    International Nuclear Information System (INIS)

    Ozaki, Akira.

    1992-01-01

    The present invention provides a small sized and economical power source device for a thermonuclear device. That is, the device comprises a conversion device having a rated power determined by a power required during a plasma current excitation period and a conversion device having a rated power determined by a power required during a plasma current maintaining period, connected in series to each other. Then, for the former conversion device, power is supplied from an electric power generator and, for the latter, power is supplied from a power system. With such a constitution, during the plasma electric current maintaining period for substantially continuous operation, it is possible to conduct bypassing paired operation for the former conversion device while the electric power generator is put under no load. Further, since a short period rated power may be suffice for the former conversion device and the electric power generator having the great rated power required for the plasma electric current excitation period, they can be reduced in the size and made economical. On the other hand, since the power required for the plasma current maintaining period is relatively small, the capacity of the continuous rated conversion device may be small, and the power can be received from the power system. (I.S.)

  11. Response of atmospheric biomarkers to NO(x)-induced photochemistry generated by stellar cosmic rays for earth-like planets in the habitable zone of M dwarf stars.

    Science.gov (United States)

    Grenfell, John Lee; Grießmeier, Jean-Mathias; von Paris, Philip; Patzer, A Beate C; Lammer, Helmut; Stracke, Barbara; Gebauer, Stefanie; Schreier, Franz; Rauer, Heike

    2012-12-01

    Understanding whether M dwarf stars may host habitable planets with Earth-like atmospheres and biospheres is a major goal in exoplanet research. If such planets exist, the question remains as to whether they could be identified via spectral signatures of biomarkers. Such planets may be exposed to extreme intensities of cosmic rays that could perturb their atmospheric photochemistry. Here, we consider stellar activity of M dwarfs ranging from quiet up to strong flaring conditions and investigate one particular effect upon biomarkers, namely, the ability of secondary electrons caused by stellar cosmic rays to break up atmospheric molecular nitrogen (N(2)), which leads to production of nitrogen oxides (NO(x)) in the planetary atmosphere, hence affecting biomarkers such as ozone (O(3)). We apply a stationary model, that is, without a time dependence; hence we are calculating the limiting case where the atmospheric chemistry response time of the biomarkers is assumed to be slow and remains constant compared with rapid forcing by the impinging stellar flares. This point should be further explored in future work with time-dependent models. We estimate the NO(x) production using an air shower approach and evaluate the implications using a climate-chemical model of the planetary atmosphere. O(3) formation proceeds via the reaction O+O(2)+M→O(3)+M. At high NO(x) abundances, the O atoms arise mainly from NO(2) photolysis, whereas on Earth this occurs via the photolysis of molecular oxygen (O(2)). For the flaring case, O(3) is mainly destroyed via direct titration, NO+O(3)→NO(2)+O(2), and not via the familiar catalytic cycle photochemistry, which occurs on Earth. For scenarios with low O(3), Rayleigh scattering by the main atmospheric gases (O(2), N(2), and CO(2)) became more important for shielding the planetary surface from UV radiation. A major result of this work is that the biomarker O(3) survived all the stellar-activity scenarios considered except for the strong

  12. Response of Atmospheric Biomarkers to NOx-Induced Photochemistry Generated by Stellar Cosmic Rays for Earth-like Planets in the Habitable Zone of M Dwarf Stars

    Science.gov (United States)

    Grießmeier, Jean-Mathias; von Paris, Philip; Patzer, A. Beate C.; Lammer, Helmut; Stracke, Barbara; Gebauer, Stefanie; Schreier, Franz; Rauer, Heike

    2012-01-01

    Abstract Understanding whether M dwarf stars may host habitable planets with Earth-like atmospheres and biospheres is a major goal in exoplanet research. If such planets exist, the question remains as to whether they could be identified via spectral signatures of biomarkers. Such planets may be exposed to extreme intensities of cosmic rays that could perturb their atmospheric photochemistry. Here, we consider stellar activity of M dwarfs ranging from quiet up to strong flaring conditions and investigate one particular effect upon biomarkers, namely, the ability of secondary electrons caused by stellar cosmic rays to break up atmospheric molecular nitrogen (N2), which leads to production of nitrogen oxides (NOx) in the planetary atmosphere, hence affecting biomarkers such as ozone (O3). We apply a stationary model, that is, without a time dependence; hence we are calculating the limiting case where the atmospheric chemistry response time of the biomarkers is assumed to be slow and remains constant compared with rapid forcing by the impinging stellar flares. This point should be further explored in future work with time-dependent models. We estimate the NOx production using an air shower approach and evaluate the implications using a climate-chemical model of the planetary atmosphere. O3 formation proceeds via the reaction O+O2+M→O3+M. At high NOx abundances, the O atoms arise mainly from NO2 photolysis, whereas on Earth this occurs via the photolysis of molecular oxygen (O2). For the flaring case, O3 is mainly destroyed via direct titration, NO+O3→NO2+O2, and not via the familiar catalytic cycle photochemistry, which occurs on Earth. For scenarios with low O3, Rayleigh scattering by the main atmospheric gases (O2, N2, and CO2) became more important for shielding the planetary surface from UV radiation. A major result of this work is that the biomarker O3 survived all the stellar-activity scenarios considered except for the strong case, whereas the biomarker

  13. Photochemistry of Fe:H2O Adducts in Argon Matrixes: A Combined Experimental and Theoretical Study in the Mid-IR and UV-Visible Regions.

    Science.gov (United States)

    Deguin, Vincent; Mascetti, Joëlle; Simon, Aude; Ben Amor, Nadia; Aupetit, Christian; Latournerie, Sandra; Noble, Jennifer A

    2018-01-18

    The photochemistry of Fe:H 2 O adducts is of interest in fields as diverse as catalysis and astrochemistry. Industrially, iron can be used as a catalyst to convert H 2 O to H 2 , whereas in the interstellar medium it may be an important component of dust grains, influencing the chemistry on their icy surfaces. This study consisted of the deposition and spectral characterization of binary systems of atomic iron with H 2 O in cryogenic argon matrixes. In this way, we were able to obtain information about the interaction of the two species; we observed the formation of adducts of iron monomers and dimers with water molecules in the mid-IR and UV-visible spectral domains. Upon irradiation with a UV radiation source, the iron species were inserted into the water molecules to form HFeOH and HFe 2 OH, leading in some cases to the formation of FeO possibly accompanied by the production of H 2 . DFT and correlated multireference wave function calculations confirmed our attributions. This combination of IR and UV-visible spectroscopy with theoretical calculations allowed us to determine, for the first time, the spectral characteristics of iron adducts and their photoproducts in the UV-visible and in the OH stretching region of the mid-IR domain.

  14. PHOTOCHEMISTRY IN THE INNER LAYERS OF CLUMPY CIRCUMSTELLAR ENVELOPES: FORMATION OF WATER IN C-RICH OBJECTS AND OF C-BEARING MOLECULES IN O-RICH OBJECTS

    International Nuclear Information System (INIS)

    Agundez, Marcelino; Cernicharo, Jose; Guelin, Michel

    2010-01-01

    A mechanism based on the penetration of interstellar ultraviolet photons into the inner layers of clumpy circumstellar envelopes (CSEs) around asymptotic giant branch stars is proposed to explain the non-equilibrium chemistry observed in such objects. We show through a simple modeling approach that in CSEs with a certain degree of clumpiness or with moderately low mass loss rates (a few 10 -7 M sun yr -1 ) a photochemistry can take place in the warm and dense inner layers, inducing important changes in the chemical composition. In carbon-rich objects water vapor and ammonia would be formed with abundances of 10 -8 -10 -6 relative to H 2 , while in oxygen-rich envelopes ammonia and carbon-bearing molecules such as HCN and CS would form with abundances of 10 -9 -10 -7 relative to H 2 . The proposed mechanism would explain the recent observation of warm water vapor in the carbon-rich envelope IRC+10216 with the Herschel Space Observatory and predict that H 2 O should be detectable in other carbon-rich objects.

  15. Photogeneration of reactive transient species upon irradiation of natural water samples: Formation quantum yields in different spectral intervals, and implications for the photochemistry of surface waters.

    Science.gov (United States)

    Marchisio, Andrea; Minella, Marco; Maurino, Valter; Minero, Claudio; Vione, Davide

    2015-04-15

    Chromophoric dissolved organic matter (CDOM) in surface waters is a photochemical source of several transient species such as CDOM triplet states ((3)CDOM*), singlet oxygen ((1)O2) and the hydroxyl radical (OH). By irradiation of lake water samples, it is shown here that the quantum yields for the formation of these transients by CDOM vary depending on the irradiation wavelength range, in the order UVB > UVA > blue. A possible explanation is that radiation at longer wavelengths is preferentially absorbed by the larger CDOM fractions, which show lesser photoactivity compared to smaller CDOM moieties. The quantum yield variations in different spectral ranges were definitely more marked for (3)CDOM* and OH compared to (1)O2. The decrease of the quantum yields with increasing wavelength has important implications for the photochemistry of surface waters, because long-wavelength radiation penetrates deeper in water columns compared to short-wavelength radiation. The average steady-state concentrations of the transients ((3)CDOM*, (1)O2 and OH) were modelled in water columns of different depths, based on the experimentally determined wavelength trends of the formation quantum yields. Important differences were found between such modelling results and those obtained in a wavelength-independent quantum yield scenario. Copyright © 2015 Elsevier Ltd. All rights reserved.

  16. Multiphase modeling of nitrate photochemistry in the quasi-liquid layer (QLL: implications for NOx release from the Arctic and coastal Antarctic snowpack

    Directory of Open Access Journals (Sweden)

    A. Saiz-Lopez

    2008-08-01

    Full Text Available We utilize a multiphase model, CON-AIR (Condensed Phase to Air Transfer Model, to show that the photochemistry of nitrate (NO3− in and on ice and snow surfaces, specifically the quasi-liquid layer (QLL, can account for NOx volume fluxes, concentrations, and [NO]/[NO2] (γ=[NO]/[NO2] measured just above the Arctic and coastal Antarctic snowpack. Maximum gas phase NOx volume fluxes, concentrations and γ simulated for spring and summer range from 5.0×104 to 6.4×105 molecules cm−3 s−1, 5.7×108 to 4.8×109 molecules cm−3, and ~0.8 to 2.2, respectively, which are comparable to gas phase NOx volume fluxes, concentrations and γ measured in the field. The model incorporates the appropriate actinic solar spectrum, thereby properly weighting the different rates of photolysis of NO3− and NO2−. This is important since the immediate precursor for NO, for example, NO2−, absorbs at wavelengths longer than nitrate itself. Finally, one-dimensional model simulations indicate that both gas phase boundary layer NO and NO2 exhibit a negative concentration gradient as a function of height although [NO]/[NO2] are approximately constant. This gradient is primarily attributed to gas phase reactions of NOx with halogens oxides (i.e. as BrO and IO, HOx, and hydrocarbons, such as CH3O2.

  17. Implantable Medical Devices

    Science.gov (United States)

    ... Artery Disease Venous Thromboembolism Aortic Aneurysm More Implantable Medical Devices Updated:Sep 16,2016 For Rhythm Control ... a Heart Attack Introduction Medications Surgical Procedures Implantable Medical Devices • Life After a Heart Attack • Heart Attack ...

  18. Devices for hearing loss

    Science.gov (United States)

    ... the sounds you want to hear. Assistive listening devices bring certain sounds directly to your ears. This can ... a small room or on a stage. Other devices can bring the sound from your TV, radio, or music ...

  19. Novel Magnetic Devices

    National Research Council Canada - National Science Library

    Schuller, Ivan

    2007-01-01

    ...: ballistic magnetoresistance, magnetic field proximity effect and spin drag. These three phenomena would then be exploited for the design of novel device architectures and to investigate the physical principles behind these devices...

  20. Smart devices are different

    DEFF Research Database (Denmark)

    Stisen, Allan; Blunck, Henrik; Bhattacharya, Sourav

    2015-01-01

    research results. This is due to variations in training and test device hardware and their operating system characteristics among others. In this paper, we systematically investigate sensor-, device- and workload-specific heterogeneities using 36 smartphones and smartwatches, consisting of 13 different...... device models from four manufacturers. Furthermore, we conduct experiments with nine users and investigate popular feature representation and classification techniques in HAR research. Our results indicate that on-device sensor and sensor handling heterogeneities impair HAR performances significantly...

  1. Heterostructures and quantum devices

    CERN Document Server

    Einspruch, Norman G

    1994-01-01

    Heterostructure and quantum-mechanical devices promise significant improvement in the performance of electronic and optoelectronic integrated circuits (ICs). Though these devices are the subject of a vigorous research effort, the current literature is often either highly technical or narrowly focused. This book presents heterostructure and quantum devices to the nonspecialist, especially electrical engineers working with high-performance semiconductor devices. It focuses on a broad base of technical applications using semiconductor physics theory to develop the next generation of electrical en

  2. Rooting an Android Device

    Science.gov (United States)

    2015-09-01

    1. Overview The purpose of this document is to demonstrate how to gain administrative privileges on an Android device. The term “rooting” is...is applicable for the Samsung Galaxy S3 as well as many other Android devices, but there are several steps involved in rooting an Android device (as...root access has been granted. 4. Conclusion This document serves as a tutorial on how to grant user administrative privilege to an Android device by

  3. Photovoltaic device and method

    Science.gov (United States)

    Cleereman, Robert J; Lesniak, Michael J; Keenihan, James R; Langmaid, Joe A; Gaston, Ryan; Eurich, Gerald K; Boven, Michelle L

    2015-01-27

    The present invention is premised upon an improved photovoltaic device ("PVD") and method of use, more particularly to an improved photovoltaic device with an integral locator and electrical terminal mechanism for transferring current to or from the improved photovoltaic device and the use as a system.

  4. Radioactive waste processing device

    International Nuclear Information System (INIS)

    Inaguma, Masahiko; Takahara, Nobuaki; Hara, Satomi.

    1996-01-01

    In a processing device for filtering laundry liquid wastes and shower drains incorporated with radioactive materials, a fiber filtration device is disposed and an activated carbon filtration device is also disposed subsequent to the fiber filtration device. In addition, a centrifugal dewatering device is disposed for dewatering spent granular activated carbon in the activated carbon filtration device, and a minute filtering device is disposed for filtering the separated dewatering liquid. Filtrates filtered by the minute filtration device are recovered in a collecting tank. Namely, at first, suspended solid materials in laundry liquid wastes and shower drains are captured, and then, ingredients concerning COD are adsorbed in the activated carbon filtration device. The radioactive liquid wastes of spent granular activated carbon in the activated carbon filtration device are reduced by dewatering them by the centrifugal dewatering device, and then the granular activated carbon is subjected to an additional processing. Further, it is separated by filtration using the minute filtration device and removed as cakes. Since the filtrates are recovered to the collecting tank and filtered again, the water quality of the drains is not degraded. (N.H.)

  5. Inspection device in liquid

    International Nuclear Information System (INIS)

    Nagaoka, Etsuo.

    1996-01-01

    The present invention provides an inspection device in PWR reactor core in which inspection operations are made efficient by stabilizing a posture of the device in front-to-back, vertical and left-to-right directions by a simple structure. When the device conducts inspection while running in liquid, the front and the back directions of the device main body are inspected using a visual device while changing the posture by operating a front-to-back direction propulsion device and a right-to-left direction propulsion device, and a vertical direction propulsion device against to rolling, pitching and yawing of the device main body. In this case, a spherical magnet moves freely in the gravitational direction in a vibration-damping fluid in a non-magnetic spherical shell following the change of the posture of the device main body, in which the vibrations due to the movement of the spherical magnet is settled by the vibration-damping fluid thereby stabilizing the posture of the device main body. At a typical inspection posture, the settling effect is enhanced by the attraction force between the spherical magnets in the spherical shell and each of magnetic force-attracted magnetic members disposed to the outer circumference of the shell, and the posture of the device main body can be confirmed in front-to-back, right-to-left and vertical directions by each of the posture confirming magnetic sensors. (N.H.)

  6. Containment and surveillance devices

    International Nuclear Information System (INIS)

    Campbell, J.W.; Johnson, C.S.; Stieff, L.R.

    The growing acceptance of containment and surveillance as a means to increase safeguards effectiveness has provided impetus to the development of improved surveillance and containment devices. Five recently developed devices are described. The devices include one photographic and two television surveillance systems and two high security seals that can be verified while installed

  7. Radiation emitting devices act

    International Nuclear Information System (INIS)

    1970-01-01

    This Act, entitled the Radiation Emitting Devices Act, is concerned with the sale and importation of radiation emitting devices. Laws relating to the sale, lease or import, labelling, advertising, packaging, safety standards and inspection of these devices are listed as well as penalties for any person who is convicted of breaking these laws

  8. Solar panel foundation device

    Energy Technology Data Exchange (ETDEWEB)

    Hawley, W.W.

    1983-03-29

    A transportable solar panel foundation device which has a bottom member, at least one upstanding side member, and an essentially open top. The side members are angled to permit nesting of a plurality of the foundation devices, and reinforcement pads are carried by the foundation device to support legs for one or more solar panels.

  9. Articulating feedstock delivery device

    Science.gov (United States)

    Jordan, Kevin

    2013-11-05

    A fully articulable feedstock delivery device that is designed to operate at pressure and temperature extremes. The device incorporates an articulating ball assembly which allows for more accurate delivery of the feedstock to a target location. The device is suitable for a variety of applications including, but not limited to, delivery of feedstock to a high-pressure reaction chamber or process zone.

  10. Radiation emitting devices regulations

    International Nuclear Information System (INIS)

    1970-01-01

    The Radiation Emitting Devices Regulations are the regulations referred to in the Radiation Emitting Devices Act and relate to the operation of devices. They include standards of design and construction, standards of functioning, warning symbol specifications in addition to information relating to the seizure and detention of machines failing to comply with the regulations. The radiation emitting devices consist of the following: television receivers, extra-oral dental x-ray equipment, microwave ovens, baggage inspection x-ray devices, demonstration--type gas discharge devices, photofluorographic x-ray equipment, laser scanners, demonstration lasers, low energy electron microscopes, high intensity mercury vapour discharge lamps, sunlamps, diagnostic x-ray equipment, ultrasound therapy devices, x-ray diffraction equipment, cabinet x-ray equipment and therapeutic x-ray equipment

  11. Smart portable rehabilitation devices

    Directory of Open Access Journals (Sweden)

    Leahey Matt

    2005-07-01

    Full Text Available Abstract Background The majority of current portable orthotic devices and rehabilitative braces provide stability, apply precise pressure, or help maintain alignment of the joints with out the capability for real time monitoring of the patient's motions and forces and without the ability for real time adjustments of the applied forces and motions. Improved technology has allowed for advancements where these devices can be designed to apply a form of tension to resist motion of the joint. These devices induce quicker recovery and are more effective at restoring proper biomechanics and improving muscle function. However, their shortcoming is in their inability to be adjusted in real-time, which is the most ideal form of a device for rehabilitation. This introduces a second class of devices beyond passive orthotics. It is comprised of "active" or powered devices, and although more complicated in design, they are definitely the most versatile. An active or powered orthotic, usually employs some type of actuator(s. Methods In this paper we present several new advancements in the area of smart rehabilitation devices that have been developed by the Northeastern University Robotics and Mechatronics Laboratory. They are all compact, wearable and portable devices and boast re-programmable, real time computer controlled functions as the central theme behind their operation. The sensory information and computer control of the three described devices make for highly efficient and versatile systems that represent a whole new breed in wearable rehabilitation devices. Their applications range from active-assistive rehabilitation to resistance exercise and even have applications in gait training. The three devices described are: a transportable continuous passive motion elbow device, a wearable electro-rheological fluid based knee resistance device, and a wearable electrical stimulation and biofeedback knee device. Results Laboratory tests of the devices

  12. Smart portable rehabilitation devices.

    Science.gov (United States)

    Mavroidis, Constantinos; Nikitczuk, Jason; Weinberg, Brian; Danaher, Gil; Jensen, Katherine; Pelletier, Philip; Prugnarola, Jennifer; Stuart, Ryan; Arango, Roberto; Leahey, Matt; Pavone, Robert; Provo, Andrew; Yasevac, Dan

    2005-07-12

    The majority of current portable orthotic devices and rehabilitative braces provide stability, apply precise pressure, or help maintain alignment of the joints with out the capability for real time monitoring of the patient's motions and forces and without the ability for real time adjustments of the applied forces and motions. Improved technology has allowed for advancements where these devices can be designed to apply a form of tension to resist motion of the joint. These devices induce quicker recovery and are more effective at restoring proper biomechanics and improving muscle function. However, their shortcoming is in their inability to be adjusted in real-time, which is the most ideal form of a device for rehabilitation. This introduces a second class of devices beyond passive orthotics. It is comprised of "active" or powered devices, and although more complicated in design, they are definitely the most versatile. An active or powered orthotic, usually employs some type of actuator(s). In this paper we present several new advancements in the area of smart rehabilitation devices that have been developed by the Northeastern University Robotics and Mechatronics Laboratory. They are all compact, wearable and portable devices and boast re-programmable, real time computer controlled functions as the central theme behind their operation. The sensory information and computer control of the three described devices make for highly efficient and versatile systems that represent a whole new breed in wearable rehabilitation devices. Their applications range from active-assistive rehabilitation to resistance exercise and even have applications in gait training. The three devices described are: a transportable continuous passive motion elbow device, a wearable electro-rheological fluid based knee resistance device, and a wearable electrical stimulation and biofeedback knee device. Laboratory tests of the devices demonstrated that they were able to meet their design

  13. Regarding the use and misuse of retinal protonated Schiff base photochemistry as a test case for time-dependent density-functional theory

    Energy Technology Data Exchange (ETDEWEB)

    Valsson, Omar [Department of Chemistry and Applied Biosciences, ETH Zurich and Facoltà di Informatica, Instituto di Scienze Computationali, Università della Svizzera italiana, Via Giuseppe Buffi 13, CH-6900 Lugano (Switzerland); Filippi, Claudia, E-mail: c.filippi@utwente.nl [MESA+ Institute for Nanotechnology, University of Twente, P.O. Box 217, 7500 AE Enschede (Netherlands); Casida, Mark E., E-mail: mark.casida@ujf-grenoble.fr [Laboratoire de Chimie Théorique, Département de Chimie Moléculaire (DCM), Institut de Chimie Moléculaire de Grenoble (ICMG), Université Joseph Fourier, Grenoble I, F-3801 Grenoble (France)

    2015-04-14

    The excited-state relaxation of retinal protonated Schiff bases (PSBs) is an important test case for biological applications of time-dependent (TD) density-functional theory (DFT). While well-known shortcomings of approximate TD-DFT might seem discouraging for application to PSB relaxation, progress continues to be made in the development of new functionals and of criteria allowing problematic excitations to be identified within the framework of TD-DFT itself. Furthermore, experimental and theoretical ab initio advances have recently lead to a revised understanding of retinal PSB photochemistry, calling for a reappraisal of the performance of TD-DFT in describing this prototypical photoactive system. Here, we re-investigate the performance of functionals in (TD-)DFT calculations in light of these new benchmark results, which we extend to larger PSB models. We focus on the ability of the functionals to describe primarily the early skeletal relaxation of the chromophore and investigate how far along the out-of-plane pathways these functionals are able to describe the subsequent rotation around formal single and double bonds. Conventional global hybrid and range-separated hybrid functionals are investigated as the presence of Hartree-Fock exchange reduces problems with charge-transfer excitations as determined by the Peach-Benfield-Helgaker-Tozer Λ criterion and by comparison with multi-reference perturbation theory results. While we confirm that most functionals cannot render the complex photobehavior of the retinal PSB, do we also observe that LC-BLYP gives the best description of the initial part of the photoreaction.

  14. Photochemistry and photophysics of the amino and imino tautomers of 1-methylcytosine: tautomerisation as a side product of the radiationless decay.

    Science.gov (United States)

    Li, Quansong; Blancafort, Lluís

    2013-08-01

    The photochemistry and photophysics of the amino-oxo (AO) and imino-oxo (IO) tautomers of 1-methylcytosine are investigated with ab initio calculations, using the CASPT2//CASSCF approach. Our aim is to rationalize recent experimental results which show that the AO tautomer has an excited state lifetime of about 1 ps, similar to cytosine (J.-W. Ho, H.-C. Yen, W.-K. Chou, C.-N. Weng, L.-H. Cheng, H.-Q. Shi, S.-H. Lai and P.-Y. Cheng, J. Phys. Chem. A, 2011, 115, 8406-8418), and that irradiation with wavelengths shorter than 308 nm induces the AO→IO tautomerization (I. Reva, M. J. Nowak, L. Lapinski and R. Fausto, J. Phys. Chem. B, 2012, 116, 5703-5710). For the canonical AO tautomer we find two analogous decay mechanisms to those described previously for cytosine, involving a conical intersection of ethylenic type and one where the amino group is bent out of plane. Decay through these intersections provides an unreactive return path to the AO ground state species. More importantly, we have identified new decay paths that lead from the two intersections to the trans-IO tautomer, without a barrier. These paths provide the possibility of forming the IO tautomer, presumably in small yields, as a side product of the radiationless decay. Thus, we have established for the first time computationally the mechanism of the UV-induced tautomerization, which is compatible with the well-established decay mechanism for cytosine. For the IO tautomer, we also find a mechanism for the excited state interconversion of the cis and trans forms and for efficient radiationless decay through a conical intersection where the imino group is perpendicular to the ring and bent out of the plane. These results are likely to be valid also for cytosine.

  15. Aqueous Photochemistry of Secondary Organic Aerosol of α-Pinene and α-Humulene Oxidized with Ozone, Hydroxyl Radical, and Nitrate Radical

    Energy Technology Data Exchange (ETDEWEB)

    Romonosky, Dian E.; Li, Ying; Shiraiwa, Manabu; Laskin, Alexander; Laskin, Julia; Nizkorodov, Sergey

    2017-01-18

    Formation of secondary organic aerosols (SOA) from biogenic volatile organic compounds 13 (BVOC) occurs via O3- and OH-initiated reactions during the day and reactions with NO3 during the 14 night. We explored the effect of these three oxidation conditions on the molecular composition and 15 aqueous photochemistry of model SOA prepared from two common BVOC. A common monoterpene, α- 16 pinene, and sesquiterpene, α-humulene, were used to form SOA in a smog chamber via BVOC + O3, 17 BVOC + NO3, and BVOC + OH + NOx oxidation. Samples of SOA were collected, extracted in water, 18 and photolyzed in an aqueous solution in order to simulate the photochemical cloud processing of SOA. 19 The extent of change in the molecular level composition of SOA over 4 hours of photolysis (roughly 20 equivalent to 64 hours of photolysis under ambient conditions) was assessed with high-resolution 21 electrospray ionization mass spectrometry. The analysis revealed significant differences in the molecular 22 composition between monoterpene and sesquiterpene SOA formed by the different oxidation pathways. 23 The composition further evolved during photolysis with the most notable change corresponding to the 24 nearly-complete removal of nitrogen-containing organic compounds. Hydrolysis of SOA compounds also 25 occurred in parallel with photolysis. The preferential loss of larger SOA compounds during photolysis 26 and hydrolysis made the SOA compounds more volatile on average. This study suggests that cloud- and 27 fog-processing may under certain conditions lead to a reduction in the SOA loading as opposed to an 28 increase in SOA loading commonly assumed in the literature.

  16. Fluid circulation control device

    International Nuclear Information System (INIS)

    Benard, Henri; Henocque, Jean.

    1982-01-01

    Horizontal fluid circulation control device, of the type having a pivoting flap. This device is intended for being fitted in the pipes of hydraulic installation, particularly in a bleed and venting system of a nuclear power station shifting radioactive or contaminated liquids. The characteristic of this device is the cut-out at the top of the flap to allow the air contained in the pipes to flow freely [fr

  17. Mobile Device Encryption Systems

    OpenAIRE

    Teufl , Peter; Zefferer , Thomas; Stromberger , Christof

    2013-01-01

    Part 4: Software Security; International audience; The initially consumer oriented iOS and Android platforms, and the newly available Windows Phone 8 platform start to play an important role within business related areas. Within the business context, the devices are typically deployed via mobile device management (MDM) solutions, or within the bring-your-own-device (BYOD) context. In both scenarios, the security depends on many platform security functions, such as permission systems, manageme...

  18. Temperature indicating device

    International Nuclear Information System (INIS)

    Angus, J.P.; Salt, D.

    1988-01-01

    A temperature indicating device comprises a plurality of planar elements some undergoing a reversible change in appearance at a given temperature the remainder undergoing an irreversible change in appearance at a given temperature. The device is useful in indicating the temperature which an object has achieved as well as its actual temperature. The reversible change is produced by liquid crystal devices. The irreversible change is produced by an absorbent surface carrying substances e.g. waxes which melt at predetermined temperatures and are absorbed by the surface; alternatively paints may be used. The device is used for monitoring processes of encapsulation of radio active waste. (author)

  19. Ion trap device

    Science.gov (United States)

    Ibrahim, Yehia M.; Smith, Richard D.

    2016-01-26

    An ion trap device is disclosed. The device includes a series of electrodes that define an ion flow path. A radio frequency (RF) field is applied to the series of electrodes such that each electrode is phase shifted approximately 180 degrees from an adjacent electrode. A DC voltage is superimposed with the RF field to create a DC gradient to drive ions in the direction of the gradient. A second RF field or DC voltage is applied to selectively trap and release the ions from the device. Further, the device may be gridless and utilized at high pressure.

  20. Recoil transporter devices

    International Nuclear Information System (INIS)

    Madhavan, N.

    2005-01-01

    The study of sparsely produced nuclear reaction products in the direction of intense primary beam is a challenging task, the pursuit of which has given rise to the advent or several types of selective devices. These range from a simple parallel plate electrostatic deflector to state-of-the-art electromagnetic separators. There is no single device which can satisfy all the requirements of an ideal recoil transporter, simultaneously. An overview of such devices and their building blocks is presented, which may help in the proper choice of the device as per the experimental requirements. (author)

  1. Establishment Registration & Device Listing

    Data.gov (United States)

    U.S. Department of Health & Human Services — This searchable database contains establishments (engaged in the manufacture, preparation, propagation, compounding, assembly, or processing of medical devices...

  2. Virtual Training Devices Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — The Virtual Training Devices (VTD) Laboratory at the Life Cycle Software Engineering Center, Picatinny Arsenal, provides a software testing and support environment...

  3. High heat flux device of thermonuclear device

    International Nuclear Information System (INIS)

    Tachikawa, Nobuo.

    1994-01-01

    The present invention provides an equipments for high heat flux device (divertor) of a thermonuclear device, which absorbs thermal deformation during operation, has a high installation accuracy, and sufficiently withstands for thermal stresses. Namely, a heat sink member is joined to a structural base. Armour tiles are joined on the heat sink member. Cooling pipes are disposed between the heat sink member and the armour tiles. With such a constitution, the heat sink member using a highly heat conductive material having ductility, such as oxygen free copper, the cooling pipes using a material having excellent high temperature resistance and excellent elongation, such as aluminum-dispersed reinforced copper, and the armour tiles are completely joined on the structural base. Therefore, when thermal deformation tends to cause in the high heat flux device such as a divertor, cooling pipes cause no plastic deformation because of their high temperature resistance, but the heat sink member such as a oxygen free copper causes plastic deformation to absorb thermal deformation. As a result, the high heat flux device such as a divertor causes no deformation. (I.S.)

  4. Repairing method and device for thermonuclear device

    International Nuclear Information System (INIS)

    Sakurai, Akiko; Masumoto, Hiroshi; Tachikawa, Nobuo.

    1995-01-01

    The present invention provides a method of and a device for repairing a first wall and a divertor disposed in a vacuum vessel of a thermonuclear device. Namely, an armour tile of the divertor secured, by a brazing material, in a vacuum vessel of the thermonuclear device in which high temperature plasmas of deuterium and tritium are confined to cause fusion reaction is induction-heated or heated by microwaves to melt the brazing material. Only the armour tile is thus exchanged by its attachment/detachment. This device comprises, in the vacuum vessel, an armour tile attaching/detaching manipulator and a repairing manipulator comprising a heating manipulator having induction heating coils at the top end thereof. Induction heating coils are connected to an AC power source. According to the present invention, the armour tile is exchanged without taking the divertor out of the vacuum vessel. Therefore, cutting of a divertor cooling tube for taking the divertor out of the vacuum vessel and re-welding of the divertor for attaching it to the vacuum vessel again are no more necessary. (I.S.)

  5. Air emissions in France. Metropolitan area substances implied in acidification, eutrophication and photochemistry; Emissions dans l'air en France. Metropole substances impliquees dans les phenomenes d'acidification, d'eutrophisation et de photochimie

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2002-04-01

    Acidification, eutrophication and photochemistry: SO{sub 2}, NO{sub x}, NH{sub 3}, NMVOCs (total and speciation relating to more than 200 different compounds), CO, acid equivalent index (Aeq) and photochemical ozone creation potential (POCP) are presented. Density ratios relating to population, area, gross product, primary energy consumption, etc. Emissions are presented by the mean of charts for each substance and the main source categories with a five years step until 1990 then yearly beyond. Dates corresponding to the maximum and minimum values are also included. (author)

  6. Partial Device Fingerprints

    NARCIS (Netherlands)

    Ciere, M.; Hernandez Ganan, C.; van Eeten, M.J.G.

    2017-01-01

    In computing, remote devices may be identified by means of device fingerprinting, which works by collecting a myriad of clientside attributes such as the device’s browser and operating system version, installed plugins, screen resolution, hardware artifacts, Wi-Fi settings, and anything else

  7. Unconventional Quantum Computing Devices

    OpenAIRE

    Lloyd, Seth

    2000-01-01

    This paper investigates a variety of unconventional quantum computation devices, including fermionic quantum computers and computers that exploit nonlinear quantum mechanics. It is shown that unconventional quantum computing devices can in principle compute some quantities more rapidly than `conventional' quantum computers.

  8. Magnetic sensor device

    NARCIS (Netherlands)

    2009-01-01

    The present invention provides a sensor device and a method for detg. the presence and/or amt. of target moieties in a sample fluid, the target moieties being labeled with magnetic or magnetizable objects. The sensor device comprises a magnetic field generating means adapted for applying a retention

  9. Process control device

    International Nuclear Information System (INIS)

    Hayashi, Toshifumi; Kobayashi, Hiroshi.

    1994-01-01

    A process control device comprises a memory device for memorizing a plant operation target, a plant state or a state of equipments related with each other as control data, a read-only memory device for storing programs, a plant instrumentation control device or other process control devices, an input/output device for performing input/output with an operator, and a processing device which conducts processing in accordance with the program and sends a control demand or a display demand to the input/output device. The program reads out control data relative to a predetermined operation target, compares and verify them with actual values to read out control data to be a practice premise condition which is further to be a practice premise condition if necessary, thereby automatically controlling the plant or requiring or displaying input. Practice presuming conditions for the operation target can be examined succesively in accordance with the program without constituting complicated logical figures and AND/OR graphs. (N.H.)

  10. EPICS GPIB device support

    International Nuclear Information System (INIS)

    Winans, J.

    1993-01-01

    A GPIB device support module is used to provide access to the operating parameters of a GPIB device. GPIB devices may be accessed via National Instruments 1014 cards or via Bitbus Universal Gateways. GPIB devices typically have many parameters, each of which may be thought of in terms of the standard types of database records available in EPICS. It is the job of the device support module designer to decide how the mapping of these parameters will be made to the available record types. Once this mapping is complete, the device support module may be written. The writing of the device support module consists primarily of the construction of a parameter table. This table is used to associate the database record types with the operating parameters of the GPIB instrument. Other aspects of module design include the handling of SRQ events and errors. SRQ events are made available to the device support module if so desired. The processing of an SRQ event is completely up to the designer of the module. They may be ignored, tied to event based record processing, or anything else the designer wishes. Error conditions may be handled in a similar fashion

  11. Positioning devices for patients

    International Nuclear Information System (INIS)

    Heavens, M.

    1981-01-01

    It has been suggested that it is very important to position patients reproducibly at different stages of radiotherapy treatment planning and treatment, or similar procedures. Devices have been described for positioning a patient's upper and lower thorax. This invention provides reproducible positioning for a female patient's breasts, for example in planning treatment of and treating breast tumours. The patient is placed prone, using for example an upper thorax device. A support device is placed central to and beneath her breasts to partially displace them outwards. The device may be triangular in section with one apex contacting the chest wall at the sternum. Restraining straps may be provided to hold the breasts against the support device. Means may be provided to take a healthy breast from the path of radiation through the tumour. (author)

  12. Safety rod driving device

    International Nuclear Information System (INIS)

    Murakami, Kiyonobu; Kurosaki, Akira.

    1988-01-01

    Purpose: To rapidly insert safety rods for a criticality experiment device into a reactor core container to stop the criticality reaction thereby prevent reactivity accidents. Constitution: A cylinder device having a safety rod as a cylinder rod attached with a piston at one end is constituted. The piston is elevated by pressurized air and attracted and fixed by an electromagnet which is a stationary device disposed at the upper portion of the cylinder. If the current supply to the electromagnet is disconnected, the safety rod constituting the cylinder rod is fallen together with the piston to the lower portion of the cylinder. Since the cylinder rod driving device has neither electrical motor nor driving screw as in the conventional device, necessary space can be reduced and the weight is decreased. In addition, since the inside of the nuclear reactor can easily be shielded completely from the external atmosphere, leakage of radioactive materials can be prevented. (Horiuchi, T.)

  13. Compound semiconductor device modelling

    CERN Document Server

    Miles, Robert

    1993-01-01

    Compound semiconductor devices form the foundation of solid-state microwave and optoelectronic technologies used in many modern communication systems. In common with their low frequency counterparts, these devices are often represented using equivalent circuit models, but it is often necessary to resort to physical models in order to gain insight into the detailed operation of compound semiconductor devices. Many of the earliest physical models were indeed developed to understand the 'unusual' phenomena which occur at high frequencies. Such was the case with the Gunn and IMPATI diodes, which led to an increased interest in using numerical simulation methods. Contemporary devices often have feature sizes so small that they no longer operate within the familiar traditional framework, and hot electron or even quantum­ mechanical models are required. The need for accurate and efficient models suitable for computer aided design has increased with the demand for a wider range of integrated devices for operation at...

  14. Metallic spintronic devices

    CERN Document Server

    Wang, Xiaobin

    2014-01-01

    Metallic Spintronic Devices provides a balanced view of the present state of the art of metallic spintronic devices, addressing both mainstream and emerging applications from magnetic tunneling junction sensors and spin torque oscillators to spin torque memory and logic. Featuring contributions from well-known and respected industrial and academic experts, this cutting-edge work not only presents the latest research and developments but also: Describes spintronic applications in current and future magnetic recording devicesDiscusses spin-transfer torque magnetoresistive random-access memory (STT-MRAM) device architectures and modelingExplores prospects of STT-MRAM scaling, such as detailed multilevel cell structure analysisInvestigates spintronic device write and read optimization in light of spintronic memristive effectsConsiders spintronic research directions based on yttrium iron garnet thin films, including spin pumping, magnetic proximity, spin hall, and spin Seebeck effectsProposes unique solutions for ...

  15. Device for cutting protrusions

    Science.gov (United States)

    Bzorgi, Fariborz M [Knoxville, TN

    2011-07-05

    An apparatus for clipping a protrusion of material is provided. The protrusion may, for example, be a bolt head, a nut, a rivet, a weld bead, or a temporary assembly alignment tab protruding from a substrate surface of assembled components. The apparatus typically includes a cleaver having a cleaving edge and a cutting blade having a cutting edge. Generally, a mounting structure configured to confine the cleaver and the cutting blade and permit a range of relative movement between the cleaving edge and the cutting edge is provided. Also typically included is a power device coupled to the cutting blade. The power device is configured to move the cutting edge toward the cleaving edge. In some embodiments the power device is activated by a momentary switch. A retraction device is also generally provided, where the retraction device is configured to move the cutting edge away from the cleaving edge.

  16. Electron energy device for LINAC based Pulse Radiolysis Facility of RPCD

    International Nuclear Information System (INIS)

    Toley, M.A.; Shinde, S.J.; Chaudhari, B.B.; Sarkar, S.K.

    2015-07-01

    The pulse radiolysis facility is the experimental centerpiece of the radiation chemistry activities of the Radiation and Photochemistry Division (RPCD) of Bhabha Atomic Research Centre. This facility was created in 1986 which is based on a 7 MeV Linear Electron Accelerator (LINAC) procured from M/s Radiation Dynamics Ltd., UK. The electron energy is one of the principal parameters that influence the dose distribution within the sample irradiated with a beam of energetic electrons. An easy-to-use and robust device has been developed that can reliably detect day-today small variations in the beam energy. It consists of two identical aluminum plates except for their thickness, which are electrically insulated from each other. The thickness of each plate is carefully selected depending on the electron beam energy. The charge (or current) collected by each plate, under irradiation is measured. The ratio of the charge (or current) signal from the front plate to the sum of the signals from the front and rear plates is very sensitive to the beam energy. The high sensitivity and robustness make this device quite suitable for Electron energy measurement for Pulse radiolysis Facility at RPCD. (author)

  17. Baking exhaustion device in thermonuclear device

    Energy Technology Data Exchange (ETDEWEB)

    Kondo, Mitsunori.

    1987-02-02

    Purpose: To rapidly remove tritium and impurity from the vacuum region in the access port of the baking exhaustion device in a thermonuclear device. Constitution: Each of the gaps at the boundary between a fixed shielding member and a blanket module and at the boundary between the blanket and a divertor is made extremely small so as to minimize the neutron streaming from plasmas. Accordingly, in the case of evacuating the vacuum region in the access port, the gap conductance is extremely poor and the exhaustion speed is low. Then, baking pipeways for flowing high temperature fluids are embedded to the surface layer at the position facing to the vacuum region and the plasma evacuation duct and the vacuum region are connected with an evacuation duct of the access port. By flowing high temperature fluids in the pipeways and conducting evacuation, baking exhaustion can be carried out rapidly. (Kamimura, M.).

  18. Plasma facing device of thermonuclear device

    International Nuclear Information System (INIS)

    Sumita, Hideo; Ioki, Kimihiro.

    1993-01-01

    The present invention improves integrity of thermal structures of a plasma facing device. That is, in the plasma facing device, an armour block portion from a metal cooling pipe to a carbon material comprises a mixed material of the metal as the constituent material of the cooling pipe and ceramics. Then, the mixing ratio of the composition is changed continuously or stepwise to suppress peakings of remaining stresses upon production and thermal stresses upon exertion of thermal loads. Accordingly, thermal integrity of the structural materials can further be improved. In this case, a satisfactory characteristic can be obtained also by using ceramics instead of carbon for the mixed material, and the characteristic such as heat expansion coefficient is similar to that of the armour tile. (I.S.)

  19. Position measuring device

    International Nuclear Information System (INIS)

    Maeda, Kazuyuki; Takahashi, Shuichi; Maruyama, Mayumi

    1998-01-01

    The present invention provides a device capable of measuring accurate position and distance easily even at places where operator can not easily access, such as cell facilities for vitrifying radioactive wastes. Referring to a case of the vitrifying cell, an objective equipment settled in the cell is photographed by a photographing device. The image is stored in a position measuring device by way of an image input device. After several years, when the objective equipment is exchanged, a new objective equipment is photographed by a photographing device. The image is also stored in the position measuring device. The position measuring device compares the data of both of the images on the basis of pixel unit. Based on the image of the equipment before the exchange as a reference, extent of the displacement of the installation position of the equipment on the image after the exchange caused by installation error and manufacturing error is determined to decide the position of the equipment after exchange relative to the equipment before exchange. (I.S.)

  20. Incore instrumentation device

    International Nuclear Information System (INIS)

    Fujita, Kazuhiko.

    1996-01-01

    A position of a detector is detected by a driving device, and the detected values are sampled by a newly disposed central processing unit for sampling the detected values depending on the sampling position of the detected values. Since the sampling position of the detected values is detected by the driving device, the sampling position for the detection values does not rely on the speed of the driving motor of the driving device. The load on the central processing device for controlling the device is lowered by newly disposing the central processing unit for sampling detected values. When the values for the position of the detector counted after conversion to digital values reach the digital values corresponding to the detection value sampling position outputted from the central processing unit for controlling the device, a counted value comparison circuit causes the central processing unit for controlling the device to sample the detection values outputted from the detector. Then, the processing speed can be increased without interruption processings, which can save the central processing unit for sampling detection values. In addition, software can be simplified and loads can be lowered. (N.H.)

  1. Fuel pattern recognition device

    International Nuclear Information System (INIS)

    Sato, Tomomi.

    1995-01-01

    The device of the present invention monitors normal fuel exchange upon fuel exchanging operation carried out in a reactor of a nuclear power plant. Namely, a fuel exchanger is movably disposed to the upper portion of the reactor and exchanges fuels. An exclusive computer receives operation signals of the fuel exchanger during operation as inputs, and outputs reactor core fuel pattern information signals to a fuel arrangement diagnosis device. An underwater television camera outputs image signals of a fuel pattern in the reactor core to an image processing device. If there is any change in the image signals for the fuel pattern as a result of the fuel exchange operation of the fuel exchanger, the image processing device outputs the change as image signals to the fuel pattern diagnosis device. The fuel pattern diagnosis device compares the pattern information signals from the exclusive computer with the image signals from the image processing device, to diagnose the result of the fuel exchange operation performed by the fuel exchanger and inform the diagnosis by means of an image display. (I.S.)

  2. Diamond semiconducting devices

    International Nuclear Information System (INIS)

    Polowczyk, M.; Klugmann, E.

    1999-01-01

    Many efforts to apply the semiconducting diamond for construction of electronic elements: resistors, thermistors, photoresistors, piezoresistors, hallotrons, pn diodes, Schottky diodes, IMPATT diodes, npn transistor, MESFETs and MISFETs are reviewed. Considering the possibilities of acceptor and donor doping, electrical resistivity and thermal conductivity of diamond as well as high electric-field breakdown points, that diamond devices could be used at about 30-times higher frequency and more then 8200 times power than silicon devices. Except that, due to high heat resistant of diamond, it is concluded that diamond devices can be used in environment at high temperature, range of 600 o C. (author)

  3. Fundamentals of semiconductor devices

    CERN Document Server

    Lindmayer, Joseph

    1965-01-01

    Semiconductor properties ; semiconductor junctions or diodes ; transistor fundamentals ; inhomogeneous impurity distributions, drift or graded-base transistors ; high-frequency properties of transistors ; band structure of semiconductors ; high current densities and mechanisms of carrier transport ; transistor transient response and recombination processes ; surfaces, field-effect transistors, and composite junctions ; additional semiconductor characteristics ; additional semiconductor devices and microcircuits ; more metal, insulator, and semiconductor combinations for devices ; four-pole parameters and configuration rotation ; four-poles of combined networks and devices ; equivalent circuits ; the error function and its properties ; Fermi-Dirac statistics ; useful physical constants.

  4. Electronic devices and circuits

    CERN Document Server

    Pridham, Gordon John

    1972-01-01

    Electronic Devices and Circuits, Volume 3 provides a comprehensive account on electronic devices and circuits and includes introductory network theory and physics. The physics of semiconductor devices is described, along with field effect transistors, small-signal equivalent circuits of bipolar transistors, and integrated circuits. Linear and non-linear circuits as well as logic circuits are also considered. This volume is comprised of 12 chapters and begins with an analysis of the use of Laplace transforms for analysis of filter networks, followed by a discussion on the physical properties of

  5. Evolution of atherectomy devices.

    Science.gov (United States)

    Al Khoury, G; Chaer, R

    2011-08-01

    Percutaneous atherectomy provides an alternative approach to the endovascular treatment of peripheral atherosclerotic occlusive disease beyond angioplasty and stenting, and has the theoretical advantage of lesion debulking and minimizing barotrauma to the vessel wall. Atherectomy has evolved greatly during the last decade, with currently four FDA approved devices for the treatment of peripheral arterial disease. Several reports have focused on the initial technical success rates, and demonstrated the safety and short as well as mid-term efficacy of atherectomy devices. This article will review the evolution of current atherectomy devices and the associated literature.

  6. Introduction to Semiconductor Devices

    Science.gov (United States)

    Brennan, Kevin F.

    2005-03-01

    This volume offers a solid foundation for understanding the most important devices used in the hottest areas of electronic engineering today, from semiconductor fundamentals to state-of-the-art semiconductor devices in the telecommunications and computing industries. Kevin Brennan describes future approaches to computing hardware and RF power amplifiers, and explains how emerging trends and system demands of computing and telecommunications systems influence the choice, design and operation of semiconductor devices. In addition, he covers MODFETs and MOSFETs, short channel effects, and the challenges faced by continuing miniaturization. His book is both an excellent senior/graduate text and a valuable reference for practicing engineers and researchers.

  7. Proton therapy device

    International Nuclear Information System (INIS)

    Tronc, D.

    1994-01-01

    The invention concerns a proton therapy device using a proton linear accelerator which produces a proton beam with high energies and intensities. The invention lies in actual fact that the proton beam which is produced by the linear accelerator is deflected from 270 deg in its plan by a deflecting magnetic device towards a patient support including a bed the longitudinal axis of which is parallel to the proton beam leaving the linear accelerator. The patient support and the deflecting device turn together around the proton beam axis while the bed stays in an horizontal position. The invention applies to radiotherapy. 6 refs., 5 figs

  8. Nanoelectronic device applications handbook

    CERN Document Server

    Morris, James E

    2013-01-01

    Nanoelectronic Device Applications Handbook gives a comprehensive snapshot of the state of the art in nanodevices for nanoelectronics applications. Combining breadth and depth, the book includes 68 chapters on topics that range from nano-scaled complementary metal-oxide-semiconductor (CMOS) devices through recent developments in nano capacitors and AlGaAs/GaAs devices. The contributors are world-renowned experts from academia and industry from around the globe. The handbook explores current research into potentially disruptive technologies for a post-CMOS world.These include: Nanoscale advance

  9. Physics of photonic devices

    CERN Document Server

    Chuang, Shun Lien

    2009-01-01

    The most up-to-date book available on the physics of photonic devices This new edition of Physics of Photonic Devices incorporates significant advancements in the field of photonics that have occurred since publication of the first edition (Physics of Optoelectronic Devices). New topics covered include a brief history of the invention of semiconductor lasers, the Lorentz dipole method and metal plasmas, matrix optics, surface plasma waveguides, optical ring resonators, integrated electroabsorption modulator-lasers, and solar cells. It also introduces exciting new fields of research such as:

  10. Output hardcopy devices

    CERN Document Server

    Durbeck, Robert

    1988-01-01

    Output Hardcopy Devices provides a technical summary of computer output hardcopy devices such as plotters, computer output printers, and CRT generated hardcopy. Important related technical areas such as papers, ribbons and inks, color techniques, controllers, and character fonts are also covered. Emphasis is on techniques primarily associated with printing, as well as the plotting capabilities of printing devices that can be effectively used for computer graphics in addition to their various printing functions. Comprised of 19 chapters, this volume begins with an introduction to vector and ras

  11. A gauge device

    International Nuclear Information System (INIS)

    Qurnell, F.D.; Patterson, C.B.

    1982-01-01

    A readily transportable device of relative light weight comprising a pair of tensioned guides for providing accurate and stable reference planes. An embodiment comprises a pair of rods or guides in tension between a pair of end members, the end members being spaced apart by a pair of arcuate compression members. The tensioned guides provide planes of reference for measuring devices moved therealong adjacent to a component to be measured. The device is especially useful for making on-site dimensional measurements of components, such as irradiated and therefore radioactive components, that cannot readily be transported to an inspection laboratory. (author)

  12. Compound semiconductor device physics

    CERN Document Server

    Tiwari, Sandip

    2013-01-01

    This book provides one of the most rigorous treatments of compound semiconductor device physics yet published. A complete understanding of modern devices requires a working knowledge of low-dimensional physics, the use of statistical methods, and the use of one-, two-, and three-dimensional analytical and numerical analysis techniques. With its systematic and detailed**discussion of these topics, this book is ideal for both the researcher and the student. Although the emphasis of this text is on compound semiconductor devices, many of the principles discussed will also be useful to those inter

  13. Digital communication device

    DEFF Research Database (Denmark)

    2005-01-01

    The invention concerns a digital communication device like a hearing aid or a headset. The hearing aid or headset has a power supply, a signal processing device, means for receiving a wireless signal and a receiver or loudspeaker, which produces an audio signal based on a modulated pulsed signal...... point is provided which is in electrical contact with the metal of the metal box and whereby this third connection point is connected to the electric circuitry of the communication device at a point having a stable and well defined electrical potential. In this way the electro-and magnetic radiation...

  14. Powering biomedical devices

    CERN Document Server

    Romero, Edwar

    2013-01-01

    From exoskeletons to neural implants, biomedical devices are no less than life-changing. Compact and constant power sources are necessary to keep these devices running efficiently. Edwar Romero's Powering Biomedical Devices reviews the background, current technologies, and possible future developments of these power sources, examining not only the types of biomedical power sources available (macro, mini, MEMS, and nano), but also what they power (such as prostheses, insulin pumps, and muscular and neural stimulators), and how they work (covering batteries, biofluids, kinetic and ther

  15. Impact of lightning-NO on eastern United States photochemistry during the summer of 2006 as determined using the CMAQ model

    Directory of Open Access Journals (Sweden)

    D. J. Allen

    2012-02-01

    Full Text Available A lightning-nitrogen oxide (NO algorithm is implemented in the Community Multiscale Air Quality Model (CMAQ and used to evaluate the impact of lightning-NO emissions (LNOx on tropospheric photochemistry over the United States during the summer of 2006.

    For a 500 mole per flash lightning-NO source, the mean summertime tropospheric NO2 column agrees with satellite-retrieved columns to within −5 to +13%. Temporal fluctuations in the column are moderately well simulated; however, the addition of LNOx does not lead to a better simulation of day-to-day variability. The contribution of lightning-NO to the model column ranges from ∼10% in the northern US to >45% in the south-central and southeastern US. Lightning-NO adds up to 20 ppbv to upper tropospheric model ozone and 1.5–4.5 ppbv to 8-h maximum surface layer ozone, although, on average, the contribution of LNOx to model surface ozone is 1–2 ppbv less on poor air quality days. LNOx increases wet deposition of oxidized nitrogen by 43% and total deposition of nitrogen by 10%. This additional deposition reduces the mean magnitude of the CMAQ low-bias in nitrate wet deposition with respect to National Atmospheric Deposition monitors to near zero.

    Differences in urban/rural biases between model and satellite-retrieved NO2 columns were examined to identify possible problems in model chemistry and/or transport. CMAQ columns were too large over urban areas. Biases at other locations were minor after accounting for the impacts of lightning-NO emissions and the averaging kernel on model columns.

    In order to obtain an upper bound on the contribution of uncertainties in NOy chemistry to upper tropospheric NOx low biases, sensitivity calculations with updated chemistry were run for the time period of the Intercontinental Chemical Transport Experiment (INTEX-A field campaign (summer 2004

  16. Sodium aerosol recovering device

    International Nuclear Information System (INIS)

    Fujimori, Koji; Ueda, Mitsuo; Tanaka, Kazuhisa.

    1997-01-01

    A main body of a recovering device is disposed in a sodium cooled reactor or a sodium cooled test device. Air containing sodium aerosol is sucked into the main body of the recovering device by a recycling fan and introduced to a multi-staged metal mesh filter portion. The air about against each of the metal mesh filters, and the sodium aerosol in the air is collected. The air having a reduced sodium aerosol concentration circulates passing through a recycling fan and pipelines to form a circulation air streams. Sodium aerosol deposited on each of the metal mesh filters is scraped off periodically by a scraper driving device to prevent clogging of each of the metal filters. (I.N.)

  17. Incore monitoring device

    International Nuclear Information System (INIS)

    Tai, Ichiro; Shirayama, Shin-pei; Nozaki, Shin-ichi.

    1978-01-01

    Purpose: To provide an incore monitoring device wherein both radiation monitoring and acoustic monitoring are carried out simultaneously by one detector, whereby installation of the device and signal pick-up are facilitated. Incore conditions are accurately grasped. Constitution: When a neutron is irradiated in a state where a DC voltage is applied between the electrode and the vessel in the device, an ionization current is occured by (n.γ) reaction of the transformed substance as in an ionization chamber, Accordingly, a voltage drop occurs at both ends of the resistor of the radiation signal processing system, as a result of which a neutron flux can be detected. Further, when a sound is generated in the reactor, the monitoring device bottom wall which formed by a piezoelectric element detects the sound-waves. This output signal is picked up by the acoustic signal processing system to judge the generation of sound. (Aizawa, K.)

  18. Authenticated sensor interface device

    Energy Technology Data Exchange (ETDEWEB)

    Coleman, Jody Rustyn; Poland, Richard W.

    2018-05-01

    A system and method for the secure storage and transmission of data is provided. A data aggregate device can be configured to receive secure data from a data source, such as a sensor, and encrypt the secure data using a suitable encryption technique, such as a shared private key technique, a public key encryption technique, a Diffie-Hellman key exchange technique, or other suitable encryption technique. The encrypted secure data can be provided from the data aggregate device to different remote devices over a plurality of segregated or isolated data paths. Each of the isolated data paths can include an optoisolator that is configured to provide one-way transmission of the encrypted secure data from the data aggregate device over the isolated data path. External data can be received through a secure data filter which, by validating the external data, allows for key exchange and other various adjustments from an external source.

  19. Plant abnormality inspection device

    International Nuclear Information System (INIS)

    Takenaka, Toshio.

    1990-01-01

    The present invention concerns a plant abnormality inspection device for conducting remote or automatic patrolling inspection in a plant and, more particularly, relates to such a device as capable of detecting abnormal odors. That is, the device comprises a moving device for moving to a predetermined position in the plant, a plurality of gas sensors for different kind of gases to be inspected mounted thereon, a comparator for comparing the concentration of a gas detected by the gas sensor with the normal gas concentration at the predetermined position and a judging means for judging the absence or presence of abnormality depending on the combination of the result of the comparison and deliverying a signal if the state is abnormal. As a result, a slight amount of gas responsible to odors released upon abnormality of the plant can be detected by a plurality of gas sensors for different kinds gases to rapidly and easily find abnormal portions in the plant. (I.S.)

  20. Geometry and Cloaking Devices

    Science.gov (United States)

    Ochiai, T.; Nacher, J. C.

    2011-09-01

    Recently, the application of geometry and conformal mappings to artificial materials (metamaterials) has attracted the attention in various research communities. These materials, characterized by a unique man-made structure, have unusual optical properties, which materials found in nature do not exhibit. By applying the geometry and conformal mappings theory to metamaterial science, it may be possible to realize so-called "Harry Potter cloaking device". Although such a device is still in the science fiction realm, several works have shown that by using such metamaterials it may be possible to control the direction of the electromagnetic field at will. We could then make an object hidden inside of a cloaking device. Here, we will explain how to design invisibility device using differential geometry and conformal mappings.

  1. Reactor noise monitoring device

    International Nuclear Information System (INIS)

    Yamanaka, Hiroto.

    1990-01-01

    The present invention concerns a reactor noise monitoring device by detecting abnormal sounds in background noises. Vibration sounds detected by accelerometers are applied to a loose parts detector. The detector generates high alarm if there are sudden impact sounds in the background noises and applies output signals to an accumulation device. If there is slight impact sounds in the vicinity of any of the accelerometers, the accumulation device accumulates the abnormal sounds assumed to be generated from an identical site while synchronizing the waveforms for all of the channels. Then, the device outputs signals in which the background noises are cancelled, as detection signals. Therefore, S/N ratio can be improved and the abnormal sounds contained in the background noises can be detected, to thereby improve the accuracy for estimating the position where the abnormal sounds are generated. (I.S.)

  2. Marine Sanitation Devices (MSDs)

    Science.gov (United States)

    Marine sanitation devices treat or retain sewage from vessels, and have performance standards set by the EPA. This page provides information on MSDs, including who must use an MSD, states' roles, types of MSDs and standards.

  3. MDR (Medical Device Reporting)

    Data.gov (United States)

    U.S. Department of Health & Human Services — This database allows you to search the CDRH's database information on medical devices which may have malfunctioned or caused a death or serious injury during the...

  4. Tokapole II device

    International Nuclear Information System (INIS)

    Sprott, J.G.

    1978-05-01

    A discussion is given of the design and operation of the Tokapole II device. The following topics are considered: physics considerations, vacuum vessel, poloidal field, ring and support design, toroidal field, vacuum system, initial results, and future plans

  5. Plasma shutdown device

    International Nuclear Information System (INIS)

    Hosogane, Nobuyuki; Nakayama, Takahide.

    1985-01-01

    Purpose: To prevent concentration of plasma currents to the plasma center upon plasma shutdown in a torus type thermonuclear device by the injection of fuels to the plasma center thereby prevent plasma disruption at the plasma center. Constitution: The plasma shutdown device comprises a plasma current measuring device that measures the current distribution of plasmas confined within a vacuum vessel and outputs a control signal for cooling the plasma center when the plasma currents concentrate to the plasma center and a fuel supply device that supplies fuels to the plasma center for cooling the center. The fuels are injected in the form of pellets into the plasmas. The direction and the velocity of the injection are set such that the pellets are ionized at the center of the plasmas. (Horiuchi, T.)

  6. Ion funnel device

    Energy Technology Data Exchange (ETDEWEB)

    Ibrahim, Yehia M.; Chen, Tsung-Chi; Harrer, Marques B.; Tang, Keqi; Smith, Richard D.

    2017-11-21

    An ion funnel device is disclosed. A first pair of electrodes is positioned in a first direction. A second pair of electrodes is positioned in a second direction. The device includes an RF voltage source and a DC voltage source. A RF voltage with a superimposed DC voltage gradient is applied to the first pair of electrodes, and a DC voltage gradient is applied to the second pair of electrodes.

  7. Atherectomy devices: technology update

    Science.gov (United States)

    Akkus, Nuri I; Abdulbaki, Abdulrahman; Jimenez, Enrique; Tandon, Neeraj

    2015-01-01

    Atherectomy is a procedure which is performed to remove atherosclerotic plaque from diseased arteries. Atherosclerotic plaques are localized in either coronary or peripheral arterial vasculature and may have different characteristics depending on the texture of the plaque. Atherectomy has been used effectively in treatment of both coronary and peripheral arterial disease. Atherectomy devices are designed differently to either cut, shave, sand, or vaporize these plaques and have different indications. In this article, current atherectomy devices are reviewed. PMID:25565904

  8. Flexural pivot device

    International Nuclear Information System (INIS)

    Flaherty, Robert.

    1986-01-01

    A flexural pivot device or rotational actuator comprises first and sceond tubular members connected by flexural members of shape-memory-alloy. These are curved in the austenitic phase at a first temperature and after cooling to the martensitic phase are flattened. On heating one of the flexural members, it bends causing relative rotation of the tubular members. Heating of another member can produce opposite rotation. Heating is electrical or by hot gas. The device may be used in a nuclear reactor. (author)

  9. Infrared thermal annealing device

    International Nuclear Information System (INIS)

    Gladys, M.J.; Clarke, I.; O'Connor, D.J.

    2003-01-01

    A device for annealing samples within an ultrahigh vacuum (UHV) scanning tunneling microscopy system was designed, constructed, and tested. The device is based on illuminating the sample with infrared radiation from outside the UHV chamber with a tungsten projector bulb. The apparatus uses an elliptical mirror to focus the beam through a sapphire viewport for low absorption. Experiments were conducted on clean Pd(100) and annealing temperatures in excess of 1000 K were easily reached

  10. RFQ1 diagnostic devices

    International Nuclear Information System (INIS)

    Chidley, B.G.; Arbique, G.M.; de Jong, M.S.; McMichael, G.E.; Michel, W.L.; Smith, B.H.

    1991-01-01

    The diagnostic devices in use on RFQ1 will be described. They consist of a double-slit emittance-measuring unit, a 45 degree deflection energy-analysis magnet, parametric current transformers, optical beam sensors, beam-stop current monitors, and an x-ray end-point analyzer. All of these devices are able to operate up to the full output current of RFQ1 (75 mA cw at 0.6 MeV)

  11. Commercialization of microfluidic devices.

    Science.gov (United States)

    Volpatti, Lisa R; Yetisen, Ali K

    2014-07-01

    Microfluidic devices offer automation and high-throughput screening, and operate at low volumes of consumables. Although microfluidics has the potential to reduce turnaround times and costs for analytical devices, particularly in medical, veterinary, and environmental sciences, this enabling technology has had limited diffusion into consumer products. This article analyzes the microfluidics market, identifies issues, and highlights successful commercialization strategies. Addressing niche markets and establishing compatibility with existing workflows will accelerate market penetration. Copyright © 2014 Elsevier Ltd. All rights reserved.

  12. Equipment abnormality monitoring device

    International Nuclear Information System (INIS)

    Ando, Yasumasa

    1991-01-01

    When an operator hears sounds in a plantsite, the operator compares normal sounds of equipment which he previously heard and remembered with sounds he actually hears, to judge if they are normal or abnormal. According to the method, there is a worry that abnormal conditions can not be appropriately judged in a case where the number of objective equipments is increased and in a case that the sounds are changed gradually slightly. Then, the device of the present invention comprises a plurality of monitors for monitoring the operation sound of equipments, a recording/reproducing device for recording and reproducing the signals, a selection device for selecting the reproducing signals among the recorded signals, an acoustic device for converting the signals to sounds, a switching device for switching the signals to be transmitted to the acoustic device between to signals of the monitor and the recording/reproducing signals. The abnormality of the equipments can be determined easily by comparing the sounds representing the operation conditions of equipments for controlling the plant operation and the sounds recorded in their normal conditions. (N.H.)

  13. Electronic security device

    Science.gov (United States)

    Eschbach, Eugene A.; LeBlanc, Edward J.; Griffin, Jeffrey W.

    1992-01-01

    The present invention relates to a security device having a control box (12) containing an electronic system (50) and a communications loop (14) over which the system transmits a signal. The device is constructed so that the communications loop can extend from the control box across the boundary of a portal such as a door into a sealed enclosure into which access is restricted whereby the loop must be damaged or moved in order for an entry to be made into the enclosure. The device is adapted for detecting unauthorized entries into such enclosures such as rooms or containers and for recording the time at which such entries occur for later reference. Additionally, the device detects attempts to tamper or interfere with the operation of the device itself and records the time at which such events take place. In the preferred embodiment, the security device includes a microprocessor-based electronic system (50) and a detection module (72) capable of registering changes in the voltage and phase of the signal transmitted over the loop.

  14. Organic 'Plastic' Optoelectronic Devices

    International Nuclear Information System (INIS)

    Sariciftci, N.S.

    2006-01-01

    Recent developments on conjugated polymer based photovoltaic diodes and photoactive organic field effect transistors (photOFETs) are discussed. The photophysics of such devices is based on the photoinduced charge transfer from donor type semiconducting conjugated polymers onto acceptor type conjugated polymers or acceptor molecules such as Buckminsterfullerene, C 6 0. Potentially interesting applications include sensitization of the photoconductivity and photovoltaic phenomena as well as photoresponsive organic field effect transistors (photOFETs). Furthermore, organic polymeric/inorganic nanoparticle based 'hybrid' solar cells will be discussed. This talk gives an overview of materials' aspect, charge-transport, and device physics of organic diodes and field-effect transistors. Furthermore, due to the compatibility of carbon/hydrogen based organic semiconductors with organic biomolecules and living cells there can be a great opportunity to integrate such organic semiconductor devices (biOFETs) with the living organisms. In general the largely independent bio/lifesciences and information technology of today, can be thus bridged in an advanced cybernetic approach using organic semiconductor devices embedded in bio-lifesciences. This field of bio-organic electronic devices is proposed to be an important mission of organic semiconductor devices

  15. Evaluating imaging devices

    International Nuclear Information System (INIS)

    Rollo, F.D.

    1977-01-01

    The performance of any imaging device depends on two principal factors inherent to the device, namely, plane sensitivity and spatial resolution. These factors may be defined as follows: plane sensitivity is the counts per second recorded by the imaging device for each disintegration per second per square centimeter occurring within a plane sheet of radioactivity. Spatial resolution may be defined as the fidelity with which the imaging device reproduces the activity distribution of an object in the image plane. In all imaging devices, a trade-off exists between these two parameters; that is, as sensitivity improves, spatial resolution is degraded, and vice versa. Therefore, to fully evaluate an imaging system a technique should be selected that measures both parameters and reflects the trade-off between the two. In addition, the method should approximate the clinical problem, namely, the detection of a focal lesion within an activity distribution. Several methods have been described to evaluate nuclear imaging devices. The more common techniques include the use of organ phantoms, bar phantoms, line-spread functions, modulation transfer functions, contrast efficiency functions, and performance index functions. Each of these techniques is briefly described in this chapter, and their advantages and disadvantages are discussed. In addition, a phantom that can be used to simply and completely measure overall imaging system performance is described

  16. Electronic security device

    International Nuclear Information System (INIS)

    Eschbach, E.A.; LeBlanc, E.J.; Griffin, J.W.

    1992-01-01

    The present invention relates to a security device having a control box containing an electronic system and a communications loop over which the system transmits a signal. The device is constructed so that the communications loop can extend from the control box across the boundary of a portal such as a door into a sealed enclosure into which access is restricted whereby the loop must be damaged or moved in order for an entry to be made into the enclosure. The device is adapted for detecting unauthorized entries into such enclosures such as rooms or containers and for recording the time at which such entries occur for later reference. Additionally, the device detects attempts to tamper or interfere with the operation of the device itself and records the time at which such events take place. In the preferred embodiment, the security device includes a microprocessor-based electronic system and a detection module capable of registering changes in the voltage and phase of the signal transmitted over the loop. 11 figs

  17. Plasma devices for hydrocarbon reformation

    KAUST Repository

    Cha, Min

    2017-01-01

    Plasma devices for hydrocarbon reformation are provided. Methods of using the devices for hydrocarbon reformation are also provided. The devices can include a liquid container to receive a hydrocarbon source, and a plasma torch configured

  18. Flaw detection device

    International Nuclear Information System (INIS)

    Sasahara, Toshihiko

    1998-01-01

    The present invention provides a device for detecting welded portions of a reactor pressure vessel. Namely, the device of the present invention comprises (1) a casing to be disposed on the surface to be detected, (2) a probe driving means loaded to the casing, (3) a probe driven along the surface to be detected and (4) a pressure reduction means for keeping the hollow portion in the casing to an evacuated atmosphere. The casing comprises a flexible suction edge to be tightly in contact with the surface to be tested for maintaining the air tight state, (6) a guide wheel for moving the casing along the surface to be tested and (7) a handle for performing transferring operation. The flaw detection device thus constituted has following features. The working efficiency upon conducting detection is improved. The influence of the weight of the device on the detection is small. The device can be applied on the surface of a nonmagnetic material. The efficiency for the flaw detection can be improved. (I.S.)

  19. Electrical apparatus lockout device

    Energy Technology Data Exchange (ETDEWEB)

    Gonzales, R.

    1999-10-12

    A simple lockout device for electrical equipment equipped with recessed power blades is described. The device comprises a face-plate (12) having a threaded member (14) attached thereto and apertures suitable for accommodating the power blades of a piece of electrical equipment, an elastomeric nose (16) abutting the face-plate having a hole for passage of the threaded member therethrough and power blade apertures in registration with those of the face-plate, a block (20) having a recess (34) in its forward face for receiving at least a portion of the hose, a hole therein for receiving the threaded member and an integral extension (26) extending from its rear face. A thumb screw (22) suitable for turning with the hands and having internal threads suitable for engaging the threaded member attached to the face-plate is inserted into a passage in the integral extension to engage the threaded member in such a fashion that when the device is inserted over the recessed power blades of a piece of electrical equipment and the thumb screw (22) tightened, the elastomeric nose (16) is compressed between the face-plate (12) and the block (20) forcing it to expand laterally thereby securing the device in the recess and precluding the accidental or intentional energization of the piece of equipment by attachment of a power cord to the recessed power blades. Means are provided in the interval extension and the thumb screw for the attachment of a locking device (46) which will satisfy OSHA standards.

  20. Operation training aid device

    International Nuclear Information System (INIS)

    Yoshimura, Sadanori.

    1994-01-01

    The device of the present invention evaluates the propriety of an operation which is conducted optionally by a trainee depending on the state of the plant, analyzes the cause of an operation error and aids the preparation of training policy and teaching materials based on the results of the evaluation and the analysis. Namely, an operation data collection device collects operation data for the plant operation conducted by the trainee and the state of the plant during the operation. Since an operation evaluation device evaluates the plant operation in a short period of time based on the evaluation criteria of an operation evaluation knowledge base, an operation error is never overlooked. Accordingly, uniform and highly reliable operation training at definite evaluation criteria can be obtained. In addition, an error-cause analyzing device and a training policy knowledge base analyze the cause of an error inherent to each of the trainee, and it is recorded systematically independently on every trainees. Since a training policy guide device retrieves and presents an operation error and a cause of the error, there can be prepared a training policy incorporating training with respect to the operation error that each of the trainee tends to commit. (I.S.)

  1. Reactor container cooling device

    Energy Technology Data Exchange (ETDEWEB)

    Ando, Koji; Kinoshita, Shoichiro

    1995-11-10

    The device of the present invention efficiently lowers pressure and temperature in a reactor container upon occurrence of a severe accident in a BWR-type reactor and can cool the inside of the container for a long period of time. That is, (1) pipelines on the side of an exhaustion tower of a filter portion in a filter bent device of the reactor container are in communication with pipelines on the side of a steam inlet of a static container cooling device by way of horizontal pipelines, (2) a back flow check valve is disposed to horizontal pipelines, (3) a steam discharge valve for a pressure vessel is disposed closer to the reactor container than the joint portion between the pipelines on the side of the steam inlet and the horizontal pipelines. Upon occurrence of a severe accident, when the pressure vessel should be ruptured and steams containing aerosol in the reactor core should be filled in the reactor container, the inlet valve of the static container cooling device is closed. Steams are flown into the filter bent device of the reactor container, where the aerosols can be removed. (I.S.).

  2. Loose part monitoring device

    International Nuclear Information System (INIS)

    Nomura, Hiroshi.

    1992-01-01

    The device of the present invention estimates a place where loose parts occur and structural components as the loose parts in a fluid flow channel of a reactor device, to provide information thereof to a plant operator. That is, the device of the present invention comprises (1) a plurality of detectors disposed to each of equipments constituting fluid channels, (2) an abnormal sound sensing device for sensing signals from the detectors, (3) an estimation section for estimating the place where the loose parts occur and the structural components thereof based on the signals sensed by the abnormal sound sensing section, (4) a memory section for storing data of the plant structure necessary for the estimation, and (5) a display section for displaying the result of the estimation. In such a device, the position where the loose parts collide against the plant structural component and the energy thereof are estimated. The dropping path of the loose parts is estimated from the estimation position. Parts to be loose parts in the path are listed up. The parts on the list is selected based on the estimated energy thereby enabling to determine the loose parts. (I.S.)

  3. Electrical apparatus lockout device

    International Nuclear Information System (INIS)

    Gonzales, R.

    1999-01-01

    A simple lockout device for electrical equipment equipped with recessed power blades is described. The device comprises a face-plate (12) having a threaded member (14) attached thereto and apertures suitable for accommodating the power blades of a piece of electrical equipment, an elastomeric nose (16) abutting the face-plate having a hole for passage of the threaded member therethrough and power blade apertures in registration with those of the face-plate, a block (20) having a recess (34) in its forward face for receiving at least a portion of the hose, a hole therein for receiving the threaded member and an integral extension (26) extending from its rear face. A thumb screw (22) suitable for turning with the hands and having internal threads suitable for engaging the threaded member attached to the face-plate is inserted into a passage in the integral extension to engage the threaded member in such a fashion that when the device is inserted over the recessed power blades of a piece of electrical equipment and the thumb screw (22) tightened, the elastomeric nose (16) is compressed between the face-plate (12) and the block (20) forcing it to expand laterally thereby securing the device in the recess and precluding the accidental or intentional energization of the piece of equipment by attachment of a power cord to the recessed power blades. Means are provided in the interval extension and the thumb screw for the attachment of a locking device (46) which will satisfy OSHA standards

  4. Nuclear reactor monitoring device

    International Nuclear Information System (INIS)

    Mihashi, Ishi; Honma, Hitoshi.

    1993-01-01

    The monitoring device of the present invention comprises a reactor core/reactor system data measuring and controlling device, a radioactivity concentration calculation device for activated coolants for calculating a radioactivity concentration of activated coolants in a main steam and reactor water by using an appropriate physical model, a radioactivity concentration correlation and comparison device for activated coolants for comparing correlationship with a radiation dose and an abnormality alarm device. Since radioactivity of activated primary coolants is monitored at each of positions in the reactor system and occurrence of leakage and the amount thereof from a primary circuit to a secondary circuit is monitored if the reactor has secondary circuit, integrity of the reactor system can be ensured and an abnormality can be detected rapidly. Further, radioactivity concentration of activated primary circuit coolants, represented by 16 N or 15 C, is always monitored at each of positions of PWR primary circuits. When a heat transfer pipe is ruptured in a steam generator, leakage of primary circuit coolants is detected rapidly, as well as the amount of the leakage can be informed. (N.H.)

  5. Fuel inspection device

    International Nuclear Information System (INIS)

    Tsuji, Tadashi.

    1990-01-01

    The fuel inspection device of the present invention has a feature of obtaining an optimum illumination upon fuel rod interval inspection operation in a fuel pool. That is, an illumination main body used underwater is connected to a cable which is led out on a floor. A light control device is attached to the other end of the cable and an electric power cable is connected to the light control device. A light source (for example, incandescent lamp) is incorporated in the casing of the illumination main body, and a diffusion plate is disposed at the front to provide a plane light source. The light control device has a light control knob capable of remote-controlling the brightness of the light of the illumination main body. In the fuel inspection device thus constituted, halation is scarcely caused on the image screen upon inspection of fuels by a submerged type television camera to facilitate control upon inspection. Accordingly, efficiency of the fuel inspection can be improved to shorten the operation time. (I.S.)

  6. Photophysics and photochemistry of photoreactivation

    International Nuclear Information System (INIS)

    Sutherland, J.C.

    1977-01-01

    Photoreactivating enzyme (PRE) monomerizes cyclobutyl pyrimidine dimers formed in DNA by UV light (lambda < 300 nm). The enzyme requires near UV and visible wavelengths (300 < lambda < 600 nm) for activity. Possible mechanisms of action of the PRE are suggested by non-enzymatic processes in which pyrimidine dimers are monomerized by UV and visible light. Two such non-enzymatic processes are (a) photolysis of dimers resulting from direct absorption of UV, and (b) sensitized monomerization involving charge transfer complexes. Several lines of evidence suggest that the mechanism of action of the PRE more closely resembles (b) than (a). Recent experiments on the PRE from E.coli revealed the presence of new long wavelength absorption which may indicate the presence of a ground state complex. The known ability of PRE to monomerize dimers of thymine, cytosine and uracil suggests that the carbonyl groups at 2 position of the pyrimidine ring may be important in the interaction between enzyme and dimer. (author)

  7. Photochemistry and enzymology of photosynthesis

    Energy Technology Data Exchange (ETDEWEB)

    Radmer, R.

    1979-07-30

    In the first task, a specially designed mass spectrometer system monitors the gas exchange occurring in response to single short flashes of light. This apparatus will be primarily used to study photosystem II donor reactions, such as the photooxidation of hydroxylamine, hydrazine, and hydrogen peroxide. This technique will also be used to study the light-induced exchange of O/sub 2/ and CO/sub 2/ in algae. The second task, biochemical studies, will focus on the role of chloroplast copper in photosynthesis. We propose to isolate, purify, and characterize the chloroplast copper enzyme polyphenol oxidase, and attempt to elucidate its role in photosynthesis. These studies will be integrated with a new program devoted to the biochemical response of the photosynthetic membrane to stress. The third task is a series of studies on the light-harvesting and electron-transport mechanisms of C/sub 4/ plants. This program will address three basic problems: (1) the effect of different preparative procedures on various photosynthetic reactions, with particular emphasis on photosystem II reactions in corn bundle sheath chloroplasts; (2) the development and testing of photosystem II assays; and (3) studies of the stoichiometry of electron carriers in bundle sheath chloroplasts, and whether cyclic phosphorylation could be a major pathway in this tissue.

  8. Photochemistry in rare gas clusters

    International Nuclear Information System (INIS)

    Moeller, T.; Haeften, K. von; Pietrowski, R. von

    1999-01-01

    In this contribution photochemical processes in pure rare gas clusters will be discussed. The relaxation dynamics of electronically excited He clusters is investigated with luminescence spectroscopy. After electronic excitation of He clusters many sharp lines are observed in the visible and infrared spectral range which can be attributed to He atoms and molecules desorbing from the cluster. It turns out that the desorption of electronically excited He atoms and molecules is an important decay channel. The findings for He clusters are compared with results for Ar clusters. While desorption of electronically excited He atoms is observed for all clusters containing up to several thousand atoms a corresponding process in Ar clusters is only observed for very small clusters (N<10). (orig.)

  9. Photochemistry in rare gas clusters

    Energy Technology Data Exchange (ETDEWEB)

    Moeller, T.; Haeften, K. von; Pietrowski, R. von [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany). Hamburger Synchrotronstrahlungslabor; Laarman, T. [Universitaet Hamburg, II. Institut fuer Experimentalphysik, Luruper Chaussee 149, D-22761 Hamburg (Germany)

    1999-12-01

    In this contribution photochemical processes in pure rare gas clusters will be discussed. The relaxation dynamics of electronically excited He clusters is investigated with luminescence spectroscopy. After electronic excitation of He clusters many sharp lines are observed in the visible and infrared spectral range which can be attributed to He atoms and molecules desorbing from the cluster. It turns out that the desorption of electronically excited He atoms and molecules is an important decay channel. The findings for He clusters are compared with results for Ar clusters. While desorption of electronically excited He atoms is observed for all clusters containing up to several thousand atoms a corresponding process in Ar clusters is only observed for very small clusters (N<10). (orig.)

  10. Photophysics and photochemistry of photoreactivation

    Energy Technology Data Exchange (ETDEWEB)

    Sutherland, J C [California Univ., Irvine (USA)

    1977-05-01

    Photoreactivating enzyme (PRE) monomerizes cyclobutyl pyrimidine dimers formed in DNA by uv light (lambda < 300 nm). The enzyme requires near UV and visible wavelengths (300 < lambda < 600 nm) for activity. Possible mechanisms of action of the PRE are suggested by non-enzymatic processes in which pyrimidine dimers are monomerized by UV and visible light. Two such non-enzymatic processes are (a) photolysis of dimers resulting from direct absorption of UV, and (b) sensitized monomerization involving charge transfer complexes. Several lines of evidence suggest that the mechanism of action of the PRE more closely resembles (b) than (a). Recent experiments on the PRE from E.coli revealed the presence of new long wavelength absorption which may indicate the presence of a ground state complex. The known ability of PRE to monomerize dimers of thymine, cytosine and uracil suggests that the carbonyl groups at 2 position of the pyrimidine ring may be important in the interaction between enzyme and dimer.

  11. Fragment capture device

    Science.gov (United States)

    Payne, Lloyd R.; Cole, David L.

    2010-03-30

    A fragment capture device for use in explosive containment. The device comprises an assembly of at least two rows of bars positioned to eliminate line-of-sight trajectories between the generation point of fragments and a surrounding containment vessel or asset. The device comprises an array of at least two rows of bars, wherein each row is staggered with respect to the adjacent row, and wherein a lateral dimension of each bar and a relative position of each bar in combination provides blockage of a straight-line passage of a solid fragment through the adjacent rows of bars, wherein a generation point of the solid fragment is located within a cavity at least partially enclosed by the array of bars.

  12. Coating thickness measuring device

    International Nuclear Information System (INIS)

    Joffe, B.B.; Sawyer, B.E.; Spongr, J.J.

    1984-01-01

    A device especially adapted for measuring the thickness of coatings on small, complexly-shaped parts, such as, for example, electronic connectors, electronic contacts, or the like. The device includes a source of beta radiation and a radiation detector whereby backscatter of the radiation from the coated part can be detected and the thickness of the coating ascertained. The radiation source and detector are positioned in overlying relationship to the coated part and a microscope is provided to accurately position the device with respect to the part. Means are provided to control the rate of descent of the radiation source and radiation detector from its suspended position to its operating position and the resulting impact it makes with the coated part to thereby promote uniformity of readings from operator to operator, and also to avoid excessive impact with the part, thereby improving accuracy of measurement and eliminating damage to the parts

  13. Nonimaging radiant energy device

    Science.gov (United States)

    Winston, Roland; Ning, Xiaohui

    1993-01-01

    A nonimaging radiant energy device may include a hyperbolically shaped reflective element with a radiant energy inlet and a radiant energy outlet. A convex lens is provided at the radiant energy inlet and a concave lens is provided at the radiant energy outlet. Due to the provision of the lenses and the shape of the walls of the reflective element, the radiant energy incident at the radiant energy inlet within a predetermined angle of acceptance is emitted from the radiant energy outlet exclusively within an acute exit angle. In another embodiment, the radiant energy device may include two interconnected hyperbolically shaped reflective elements with a respective convex lens being provided at each aperture of the device.

  14. Endoscopic Devices for Obesity.

    Science.gov (United States)

    Sampath, Kartik; Dinani, Amreen M; Rothstein, Richard I

    2016-06-01

    The obesity epidemic, recognized by the World Health Organization in 1997, refers to the rising incidence of obesity worldwide. Lifestyle modification and pharmacotherapy are often ineffective long-term solutions; bariatric surgery remains the gold standard for long-term obesity weight loss. Despite the reported benefits, it has been estimated that only 1% of obese patients will undergo surgery. Endoscopic treatment for obesity represents a potential cost-effective, accessible, minimally invasive procedure that can function as a bridge or alternative intervention to bariatric surgery. We review the current endoscopic bariatric devices including space occupying devices, endoscopic gastroplasty, aspiration technology, post-bariatric surgery endoscopic revision, and obesity-related NOTES procedures. Given the diverse devices already FDA approved and in development, we discuss the future directions of endoscopic therapies for obesity.

  15. Radioactive gas storage device

    International Nuclear Information System (INIS)

    Sano, Yuji.

    1988-01-01

    Purpose: To easily and reliably detect the consumption of a sputtered cathode in a radioactive gas storage device using ion injection method. Constitution: Inert gases are sealed to the inside of a cathode. As the device is operated, the cathode is consumed and, if it is scraped to some extent, inert gases in the cathode gases are blown out to increase the inner pressure of the device. The pressure elevation is detected by a pressure detector connected with a gas introduction pipe or discharge pipe. Further, since the discharge current in the inside is increased along with the elevation of the pressure, it is possible to detect the increase of the electrical current. In this way, the consumption of the cathode can be recognized by detecting the elevation in the pressure or increase in the current. (Ikeda, J.)

  16. ALS insertion devices

    International Nuclear Information System (INIS)

    Hoyer, E.; Chin, J.; Halbach, K.; Hassenzahl, W.V.; Humphries, D.; Kincaid, B.; Lancaster, H.; Plate, D.

    1990-11-01

    The Advanced Light Source (ALS), the first US third generation synchrotron radiation source, is currently under construction at the Lawrence Berkeley Laboratory. The low-emittance, 1.5 GeV electron storage ring and the insertion devices are specifically designed to produce high brightness beams in the UV to soft X-Ray range. The planned initial complement of insertion devices includes four 4.6 m long undulators, with period lengths of 3.9 cm, 5.0 cm (2) and 8.0 cm, and a 2.9 m long wiggler of 16 cm period length. Undulator design is well advanced and fabrication has begun on the 5.0 cm and 8.0 cm period length undulators. This paper discusses ALS insertion device requirements; general design philosophy; and design of the magnetic structure, support structure/drive systems, control system and vacuum system. 18 refs., 9 figs., 5 tabs

  17. Steam cleaning device

    International Nuclear Information System (INIS)

    Karaki, Mikio; Muraoka, Shoichi.

    1985-01-01

    Purpose: To clean complicated and long objects to be cleaned having a structure like that of nuclear reactor fuel assembly. Constitution: Steams are blown from the bottom of a fuel assembly and soon condensated initially at the bottom of a vertical water tank due to water filled therein. Then, since water in the tank is warmed nearly to the saturation temperature, purified water is supplied from a injection device below to the injection device above the water tank on every device. In this way, since purified water is sprayed successively from below to above and steams are condensated in each of the places, the entire fuel assembly elongated in the vertical direction can be cleaned completely. Water in the reservoir goes upward like the steam flow and is drained together with the eliminated contaminations through an overflow pipe. After the cleaning has been completed, a main steam valve is closed and the drain valve is opened to drain water. (Kawakami, Y.)

  18. Laser device and method

    International Nuclear Information System (INIS)

    Myers, J.D.

    1986-01-01

    A method is described of treatment of opacity of the lens of an eye resulting from foreign matter at the back surface of the eye lens within the vitreous fluid body of the eye with a passively Q-switched laser device. The method consists of: (a) generating a single lasing pulse emitted from the laser device focused within the eye vitreous fluid body, spaced from the lens back surface, creating a microplasma dot in the vitreous fluid body (b) then increasing the frequency of the lasing pulses emitted from the lasing device having a frequency greater than the life of the microplasma to generate an elongated lasing plasma within the eye vitreous fluid moving toward the lens back surface, until the elongated lasing plasma contacts and destroys the foreign matter

  19. Meniscal repair devices.

    Science.gov (United States)

    Barber, F A; Herbert, M A

    2000-09-01

    Meniscal repair devices not requiring accessory incisions are attractive. Many factors contribute to their clinical effectiveness including their biomechanical characteristics. This study compared several new meniscal repair devices with standard meniscal suture techniques. Using a porcine model, axis-of-insertion loads were applied to various meniscal sutures and repair devices. A single device or stitch was placed in a created meniscal tear and a load applied. Both loads and modes of failure were recorded. The load-to-failure data show stratification into 4 distinct statistical groups. Group A, 113 N for a double vertical stitch; group B, 80 N for a single vertical stitch; group C, 57 N for the BioStinger, 56 N for a horizontal mattress stitch, and 50 N for the T-Fix stitch; and group D, 33 N for the Meniscus Arrow (inserted by hand or gun), 32 N for the Clearfix screw, 31 N for the SDsorb staple, 30 N for the Mitek meniscal repair system, and 27 N for the Biomet staple. The failure mechanism varied. Sutures broke away from the knot. The Meniscus Arrow and BioStinger pulled through the inner rim with the crossbar intact. The Clearfix screw failed by multiple mechanisms, whereas 1 leg of the SDsorb staple always pulled out of the outer rim. The Mitek device usually failed by pullout from the inner rim. The Biomet staple always broke at the crosshead or just below it. Although the surgeon should be aware of the material properties of the repair technique chosen for a meniscal repair, this information is only an indication of device performance and may not correlate with clinical healing results.

  20. Asphaltene based photovoltaic devices

    Science.gov (United States)

    Chianelli, Russell R.; Castillo, Karina; Gupta, Vipin; Qudah, Ali M.; Torres, Brenda; Abujnah, Rajib E.

    2016-03-22

    Photovoltaic devices and methods of making the same, are disclosed herein. The cell comprises a photovoltaic device that comprises a first electrically conductive layer comprising a photo-sensitized electrode; at least one photoelectrochemical layer comprising metal-oxide particles, an electrolyte solution comprising at least one asphaltene fraction, wherein the metal-oxide particles are optionally dispersed in a surfactant; and a second electrically conductive layer comprising a counter-electrode, wherein the second electrically conductive layer comprises one or more conductive elements comprising carbon, graphite, soot, carbon allotropes or any combinations thereof.

  1. Electronic devices and circuits

    CERN Document Server

    Pridham, Gordon John

    1968-01-01

    Electronic Devices and Circuits, Volume 1 deals with the design and applications of electronic devices and circuits such as passive components, diodes, triodes and transistors, rectification and power supplies, amplifying circuits, electronic instruments, and oscillators. These topics are supported with introductory network theory and physics. This volume is comprised of nine chapters and begins by explaining the operation of resistive, inductive, and capacitive elements in direct and alternating current circuits. The theory for some of the expressions quoted in later chapters is presented. Th

  2. INLET STRATIFICATION DEVICE

    DEFF Research Database (Denmark)

    2006-01-01

    An inlet stratification device (5) for a circuit circulating a fluid through a tank (1 ) and for providing and maintaining stratification of the fluid in the tank (1 ). The stratification de- vice (5) is arranged vertically in the tank (1) and comprises an inlet pipe (6) being at least partially...... formed of a flexible porous material and having an inlet (19) and outlets formed of the pores of the porous material. The stratification device (5) further comprises at least one outer pipe (7) surrounding the inlet pipe (6) in spaced relationship thereto and being at least partially formed of a porous...

  3. Precision alignment device

    Science.gov (United States)

    Jones, N.E.

    1988-03-10

    Apparatus for providing automatic alignment of beam devices having an associated structure for directing, collimating, focusing, reflecting, or otherwise modifying the main beam. A reference laser is attached to the structure enclosing the main beam producing apparatus and produces a reference beam substantially parallel to the main beam. Detector modules containing optical switching devices and optical detectors are positioned in the path of the reference beam and are effective to produce an electrical output indicative of the alignment of the main beam. This electrical output drives servomotor operated adjustment screws to adjust the position of elements of the structure associated with the main beam to maintain alignment of the main beam. 5 figs.

  4. Microfluidic Cell Culture Device

    Science.gov (United States)

    Takayama, Shuichi (Inventor); Cabrera, Lourdes Marcella (Inventor); Heo, Yun Seok (Inventor); Smith, Gary Daniel (Inventor)

    2014-01-01

    Microfluidic devices for cell culturing and methods for using the same are disclosed. One device includes a substrate and membrane. The substrate includes a reservoir in fluid communication with a passage. A bio-compatible fluid may be added to the reservoir and passage. The reservoir is configured to receive and retain at least a portion of a cell mass. The membrane acts as a barrier to evaporation of the bio-compatible fluid from the passage. A cover fluid may be added to cover the bio-compatible fluid to prevent evaporation of the bio-compatible fluid.

  5. Pipe closing device

    International Nuclear Information System (INIS)

    Klahn, F.C.; Nolan, J.H.; Wills, C.

    1979-01-01

    The closing device closes the upper end of a support tube for monitoring samples. It meshes with the upper connecting piece of the monitorung sample capsule, and loads the capsule within the bore of the support tube, so that it is fixed but can be released. The closing device consists of an interlocking component with a chamber and several ratchets which hang down. The interlocking component surrounds the actuating component for positioning the ratchets. The interlocking and actuating components are movable axially relative to each other. (DG) [de

  6. Preventing medical device recalls

    CERN Document Server

    Raheja, Dev

    2014-01-01

    Introduction to Medical Device RequirementsIntroductionThe ChallengesSources of ErrorsUnderstanding the Science of Safety     Overview of FDA Quality System Regulation     Overview of Risk Management Standard ISO 14971     Overview of FDA Device Approval Process     Overview of Regulatory Requirements for Clinical TrialsSummaryReferencesPreventing Recalls during Specification WritingIntroductionConduct Requirements Analysis to Identify Missing RequirementsSpecifications for Safety, Durability, and

  7. Simulation of semiconductor devices

    International Nuclear Information System (INIS)

    Oriato, D.

    2001-09-01

    In this thesis a drift diffusion model coupled with self-consistent solutions of Poisson's and Schroedinger's equations, is developed and used to investigate the operation of Gunn diodes and GaN-based LEDs. The model also includes parameters derived from Monte Carlo calculations of the simulated devices. In this way the characteristics of a Monte Carlo approach and of a quantum solver are built into a fast and flexible drift-diffusion model that can be used for testing a large number of heterostructure designs in a time-effective way. The full model and its numerical implementation are described in chapter 2. In chapter 3 the theory of Gunn diodes is presented. A basic model of the dynamics of domain formation and domain transport is described with particular regard to accumulation and dipole domains. Several modes of operation of the Gunn device are described, varying from the resonance mode to the quenched mode. Details about transferred electron devices and negative differential resistance in semiconductor materials are given. In chapter 4 results from the simulation of a simple conventional gunn device confirm the importance of the doping condition at the cathode. Accumulation or dipole domains are achieved respectively with high and low doping densities. The limits of a conventional Gunn diode are explained and solved by introducing the heterostructure Gunn diode. This new design consists of a conventional GaAs transit region coupled with an electron launcher at the cathode, made using an AIGaAs heterostructure step. Simulations show the importance of the insertion of a thin highly-doped layer between the transit region and the electron launcher in order to improve device operation. Chapter 5 is an introduction to Ill-nitrides, in particular GaN and its alloy ln-GaN. We outline the discrepancy in the elastic and piezoelectric parameters found in the literature. Strain, dislocations and piezoelectricity are presented as the main features of a InGaN/GaN system

  8. Nanoscale memory devices

    International Nuclear Information System (INIS)

    Chung, Andy; Deen, Jamal; Lee, Jeong-Soo; Meyyappan, M

    2010-01-01

    This article reviews the current status and future prospects for the use of nanomaterials and devices in memory technology. First, the status and continuing scaling trends of the flash memory are discussed. Then, a detailed discussion on technologies trying to replace flash in the near-term is provided. This includes phase change random access memory, Fe random access memory and magnetic random access memory. The long-term nanotechnology prospects for memory devices include carbon-nanotube-based memory, molecular electronics and memristors based on resistive materials such as TiO 2 . (topical review)

  9. Radiographic film digitizing devices

    International Nuclear Information System (INIS)

    McFee, W.H.

    1988-01-01

    Until recently, all film digitizing devices for use with teleradiology or picture archiving and communication systems used a video camera to capture an image of the radiograph for subsequent digitization. The development of film digitizers that use a laser beam to scan the film represents a significant advancement in digital technology, resulting in improved image quality compared with video scanners. This paper discusses differences in resolution, efficiency, reliability, and the cost between these two types of devices. The results of a modified receiver operating characteristic comparison study of a video scanner and a laser scanner manufactured by the same company are also discussed

  10. Device for removing fur

    International Nuclear Information System (INIS)

    Hanawa, Minoru; Nakagawa, Takao; Sakuma, Toyoo; Yonemura, Eizo.

    1976-01-01

    Purpose: To effectively remove fur adhered to fuel rods and to increase working efficiency without use of a lengthy hose. Constitution: In the fur removing device of the present invention, brushes rotated by gears are provided within a casing so that fur adhered to the fuel rods are removed by the brushes and water is rotatably moved by blades housed therein to outwardly blow fur floating in water by means of a centrifugal force. Then, the fur is filtered by a filter outwardly provided. In this way, the fur may be collected within the device to avoid contamination to others. (Kamimura, M.)

  11. An analysis of fast photochemistry over high northern latitudes during spring and summer using in-situ observations from ARCTAS and TOPSE

    Directory of Open Access Journals (Sweden)

    J. R. Olson

    2012-08-01

    Full Text Available Observations of chemical constituents and meteorological quantities obtained during the two Arctic phases of the airborne campaign ARCTAS (Arctic Research of the Composition of the Troposphere from Aircraft and Satellites are analyzed using an observationally constrained steady state box model. Measurements of OH and HO2 from the Penn State ATHOS instrument are compared to model predictions. Forty percent of OH measurements below 2 km are at the limit of detection during the spring phase (ARCTAS-A. While the median observed-to-calculated ratio is near one, both the scatter of observations and the model uncertainty for OH are at the magnitude of ambient values. During the summer phase (ARCTAS-B, model predictions of OH are biased low relative to observations and demonstrate a high sensitivity to the level of uncertainty in NO observations. Predictions of HO2 using observed CH2O and H2O2 as model constraints are up to a factor of two larger than observed. A temperature-dependent terminal loss rate of HO2 to aerosol recently proposed in the literature is shown to be insufficient to reconcile these differences. A comparison of ARCTAS-A to the high latitude springtime portion of the 2000 TOPSE campaign (Tropospheric Ozone Production about the Spring Equinox shows similar meteorological and chemical environments with the exception of peroxides; observations of H2O2 during ARCTAS-A were 2.5 to 3 times larger than those during TOPSE. The cause of this difference in peroxides remains unresolved and has important implications for the Arctic HOx budget. Unconstrained model predictions for both phases indicate photochemistry alone is unable to simultaneously sustain observed levels of CH2O and H2O2; however when the model is constrained with observed CH2O, H2O2 predictions from a range of

  12. Device-Centric Monitoring for Mobile Device Management

    OpenAIRE

    Chircop, Luke; Colombo, Christian; Pace, Gordon J.

    2016-01-01

    The ubiquity of computing devices has led to an increased need to ensure not only that the applications deployed on them are correct with respect to their specifications, but also that the devices are used in an appropriate manner, especially in situations where the device is provided by a party other than the actual user. Much work which has been done on runtime verification for mobile devices and operating systems is mostly application-centric, resulting in global, device-centri...

  13. Materials for electrochemical device safety

    Science.gov (United States)

    Vissers, Daniel R.; Amine, Khalil; Thackeray, Michael M.; Kahaian, Arthur J.; Johnson, Christopher S.

    2015-04-07

    An electrochemical device includes a thermally-triggered intumescent material or a gas-triggered intumescent material. Such devices prevent or minimize short circuits in a device that could lead to thermal run-away. Such devices may include batteries or supercapacitors.

  14. Device configuration-management system

    International Nuclear Information System (INIS)

    Nowell, D.M.

    1981-01-01

    The Fusion Chamber System, a major component of the Magnetic Fusion Test Facility, contains several hundred devices which report status to the Supervisory Control and Diagnostic System for control and monitoring purposes. To manage the large number of diversity of devices represented, a device configuration management system was required and developed. Key components of this software tool include the MFTF Data Base; a configuration editor; and a tree structure defining the relationships between the subsystem devices. This paper will describe how the configuration system easily accomodates recognizing new devices, restructuring existing devices, and modifying device profile information

  15. Radioactive gas storage device

    International Nuclear Information System (INIS)

    Seki, Eiji; Kobayashi, Yoshihiro.

    1989-01-01

    The present invention concerns a device of ionizing radioactive gases to be processed in gaseous nuclear fission products in nuclear fuel reprocessing plants, etc., and injecting them into metal substrates for storage. The device comprises a vessel for a tightly closed type outer electrode in which gases to be processed are introduced, an electrode disposed to the inside of the vessel and the target material, a high DC voltage power source for applying high voltage to the electrodes, etc. There are disposed a first electric discharging portion for preparting discharge plasma for ion injection of different electrode distance and a second electric discharging portion for causing stable discharge between the vessel and the electrode. The first electric discharging portion for the ion injection provides an electrode distance suitable to acceleration sputtering and the second electric discharging portion is used for stable discharge. Accordingly, if the gas pressure in the radioactive gas storage device is reduced by the external disturbance, etc., since the second electric discharging portion satisfies the electric discharging conditions, the device can continue electric discharge. (K.M.)

  16. Nano devices and sensors

    CERN Document Server

    Liaw, Shien-Kuei; Chung, Yung-Hui

    2016-01-01

    This volume on semiconductor devices focuses on such topics as nano-imprinting, lithography, nanowire charge-trapping, thermo-stability in nanowires, nano-electrodes, and voltage and materials used for fabricating and improving electrical characteristics of nano-materials.

  17. Integrated Optical lightguide device

    NARCIS (Netherlands)

    Heideman, Rene; Lambeck, Paul; Veldhuis, G.J.

    2005-01-01

    In an integrated optical lightguide device including a light-transmitting core layer, an inclusion or buffer layer, and an active or cladding layer. The cladding layer is divided into segments. Groups of different segments exhibit different refractive indices, light intensity profiles or different

  18. Integrated Optical lightguide device

    NARCIS (Netherlands)

    Heideman, Rene; Lambeck, Paul; Veldhuis, G.J.

    2000-01-01

    In an integrated optical lightguide device including a light-transmitting core layer, an inclusion or buffer layer, and an active or cladding layer. The cladding layer is divided into segments. Groups of different segments exhibit different refractive indices, light intensity profiles or different

  19. Criticality alarm device

    International Nuclear Information System (INIS)

    Kasai, Kenji.

    1994-01-01

    The device of the present invention is utilized, for example, to a reprocessing facility for storing and processing nuclear fuels and measures and controls the nuclear fuel assembly system so as not to exceed criticality. That is, a conventional criticality alarm device applies a predetermined processing to neutron fluxes generated from a nuclear fuel assembly system containing nuclear fuels and outputs an alarm. The device of the present invention comprises (1) a neutron flux supply source for increasing and decreasing neutron fluxes periodically and supplying them to nuclear fuel assemblies, (2) a detector for detecting neutron fluxes in the nuclear fuel assemblies, (3) a critical state judging section for judging the critical state of the nuclear fuel assemblies based on the periodically changing signals obtained from the detector (2) and (4) an alarm section for outputting criticality alarms depending on the result of the judgement. The device of the present invention can accurately recognize the critical state of the nuclear fuel assembly system and can forecast reaching of the nuclear fuel assembly to criticality or prompt neutron critical state. (I.S.)

  20. Static memory devices

    NARCIS (Netherlands)

    2012-01-01

    A semiconductor memory device includes n-wells (22) and p-wells (24) used to make up a plurality of memory cell elements (40). The n-wells (22) and p-5 wells (24) can be back-biased to improve reading and writing performance. One of the n-wells and p-wells can be globally biased while the other one

  1. Programmable ubiquitous telerobotic devices

    Science.gov (United States)

    Doherty, Michael; Greene, Matthew; Keaton, David; Och, Christian; Seidl, Matthew L.; Waite, William; Zorn, Benjamin G.

    1997-12-01

    We are investigating a field of research that we call ubiquitous telepresence, which involves the design and implementation of low-cost robotic devices that can be programmed and operated from anywhere on the Internet. These devices, which we call ubots, can be used for academic purposes (e.g., a biologist could remote conduct a population survey), commercial purposes (e.g., a house could be shown remotely by a real-estate agent), and for recreation and education (e.g., someone could tour a museum remotely). We anticipate that such devices will become increasingly common due to recent changes in hardware and software technology. In particular, current hardware technology enables such devices to be constructed very cheaply (less than $500), and current software and network technology allows highly portable code to be written and downloaded across the Internet. In this paper, we present our prototype system architecture, and the ubot implementation we have constructed based on it. The hardware technology we use is the handy board, a 6811-based controller board with digital and analog inputs and outputs. Our software includes a network layer based on TCP/IP and software layers written in Java. Our software enables users across the Internet to program the behavior of the vehicle and to receive image feedback from a camera mounted on it.

  2. Radiation flux measuring device

    International Nuclear Information System (INIS)

    Corte, E.; Maitra, P.

    1977-01-01

    A radiation flux measuring device is described which employs a differential pair of transistors, the output of which is maintained constant, connected to a radiation detector. Means connected to the differential pair produce a signal representing the log of the a-c component of the radiation detector, thereby providing a signal representing the true root mean square logarithmic output. 3 claims, 2 figures

  3. Magnetic-bubble devices

    International Nuclear Information System (INIS)

    Fairholme, R.J.

    1978-01-01

    Magnetic bubbles were first described only ten years ago when research workers were discussing orthoferrites containing μm diameter bubbles. However, problems of material fabrication limit crystals to a few mm across which severely curtailed device development. Since then materials have changed and rare-earth-iron garnet films can be grown up 3 inches in diameter with bubble diameters down to sizes below 1 μm. The first commercial products have device capacities in the range 64 000 to 100 000 bits with bubble diameters between 4 and 6 μm. Chip capacities of 1 Mbit are presently under development in the laboratory, as are new techniques to use submicrometre bubbles. The operation and fabrication of a bubble device is described using the serial loop devices currently being manufactured at Plessey as models. Chip organization is one important variable which directly affects the access time. A range of access times and capacities is available which offers a wide range of market opportunities, ranging from consumer products to fixed head disc replacements. some of the application areas are described. (author)

  4. Road-Cleaning Device

    Science.gov (United States)

    Roman, Harry T.

    2014-01-01

    Roadways are literally soaked with petrochemical byproducts, oils, gasoline, and other volatile substances that eventually run off into sewers and end up in rivers, waterways, and other undesirable places. Can the roads be cleaned of these wastes, with their proper disposal? Can vehicles, robots, or other devices be designed that could be driven…

  5. Loading device for incinerator

    International Nuclear Information System (INIS)

    Hempelmann, W.

    1983-01-01

    An incinerator for radioactive waste is described. Heat radiation from the incinerator into the loading device is reduced by the design of the slider with a ceramic plate and the conical widening of the pot, and also by fixing a metal plate between the pot and the floor. (PW) [de

  6. Surface Acoustic Wave Devices

    DEFF Research Database (Denmark)

    Dühring, Maria Bayard

    The work of this project is concerned with the simulation of surface acoustic waves (SAW) and topology optimization of SAW devices. SAWs are elastic vibrations that propagate along a material surface and are extensively used in electromechanical filters and resonators in telecommunication. A new...

  7. Underwater running device

    International Nuclear Information System (INIS)

    Kogure, Sumio; Matsuo, Takashiro; Yoshida, Yoji

    1996-01-01

    An underwater running device for an underwater inspection device for detecting inner surfaces of a reactor or a water vessel has an outer frame and an inner frame, and both of them are connected slidably by an air cylinder and connected rotatably by a shaft. The outer frame has four outer frame legs, and each of the outer frame legs is equipped with a sucker at the top end. The inner frame has four inner frame legs each equipped with a sucker at the top end. The outer frame legs and the inner frame legs are each connected with the outer frame and the inner frame by the air cylinder. The outer and the inner frame legs can be elevated or lowered (or extended or contracted) by the air cylinder. The sucker is connected with a jet pump-type negative pressure generator. The device can run and move by repeating attraction and releasing of the outer frame legs and the inner frame legs alternately while maintaining the posture of the inspection device stably. (I.N.)

  8. Neutron measuring device

    International Nuclear Information System (INIS)

    Hatayama, Akiyoshi; Seki, Eiji; Kita, Yoshio; Nishitani, Takeo.

    1993-01-01

    The device of the present invention concerns measurement for neutrons in a tokamak type thermonuclear device and it can measure total amount of generated neutrons accurately throughout the operation period even if an error is caused in counted values by plasma disruption. That is, the device comprises (1) a means for detecting presence or absence of occurrence of plasma disruption and the time for the initiation of the occurrence, (2) a first data processing means for processing detection signals, (3) a means for detecting neutrons generated in plasmas and (4) a second data processing means for calculating integrated values for the number of neutrons generated from the start to the completion of electric discharge when no disruption occurs and calculating integrated values for the number of generated neutrons from the start of electric discharge to the time at the initiation of occurrence of the disruption when disruption is present. In the thus constituted device, even if an error is caused by frequent occurrence of plasma disruption, total time integrated amount of neutrons generated in the plasmas can be measured accurately. (I.S.)

  9. Medical device development.

    Science.gov (United States)

    Panescu, Dorin

    2009-01-01

    The development of a successful medical product requires not only engineering design efforts, but also clinical, regulatory, marketing and business expertise. This paper reviews items related to the process of designing medical devices. It discusses the steps required to take a medical product idea from concept, through development, verification and validation, regulatory approvals and market release.

  10. Plant monitoring device

    International Nuclear Information System (INIS)

    Moriyama, Kunio.

    1991-01-01

    The monitoring device of the present invention is most suitable to early detection for equipment abnormality, or monitoring of state upon transient conditions such as startup and shutdown of an electric power plant, a large-scaled thermonuclear device and an accelerator plant. That is, in existent moitoring devices, acquired data are stored and the present operation states are monitored in comparison. A plant operation aquisition data reproduction section is disposed to the device. From the past operation conditions stored in the plant operation data aquisition reproducing section, the number of operation cycles that agrees with the present plant operation conditions is sought, to determine the agreed aquired data. Since these aquired data are time sequential data measured based on the standard time determined by the operation sequence, aquired data can be reproduced successively on every sample pitches. With such a constitution, aquired data under the same operation conditions as the present conditions are displayed together with the measured data. Accordingly, accurate monitoring can be conducted from the start-up to the shutdown of the plant. (I.S.)

  11. Laser decontamination device

    International Nuclear Information System (INIS)

    Michishita, Shizuo; Akagawa, Katsuhiko.

    1997-01-01

    One end of an optical fiber inserted into an inner cylinder is opposed to a wall surface to be decontaminated, and an opened top end of an intermediate cylinder circumferentially surrounding the inner cylinder is tightly in contact with the wall surface to be decontaminated, an open end of an outer cylinder circumferentially surrounding the intermediate cylinder is tightly in contact with the wall surface to be decontaminated. Dust removing holes are perforated in the vicinity of the top end of the intermediate cylinder while being in communication with the inside and the outside of the intermediate cylinder, and one end of an air supply tube is in communication with the space between the outer circumferential surface of the inner cylinder and the inner circumferential surface of the intermediate cylinder. The other end of the air supply tube is connected to an air supply device, one end of a sucking tube is in communication with the space between the outer circumferential surface of the intermediate cylinder and the inner circumferential surface of the outer cylinder, the other end of the sucking tube is connected to a sucking device, and the other end of the optical fiber is connected to a laser generation device. The laser generation device is operated while determining the air sucking amount increased than the air supply amount, the materials deposited on the wall surface are crushed and peeled off, and the peeled off materials are transferred by air flow to a filter and collected. (N.H.)

  12. Rotary combustion device

    NARCIS (Netherlands)

    2008-01-01

    Rotary combustion device (1) with rotary combustion chamber (4). Specific measures are taken to provide ignition of a combustible mixture. It is proposed that a hollow tube be provided coaxially with the axis of rotation (6), so that a small part of the mixture is guided into the combustion chamber.

  13. Devic's Disease (Neuromyelitis optical)

    International Nuclear Information System (INIS)

    Pinzon, Alfredo; Echeverry, Tatiana; Rodriguez, Aida Bibiana

    2010-01-01

    We present a case report about a young woman initially treated as having multiple sclerosis, who relapsed with serious visual impairment. Devic's disease is a demyelinating disorder that presents as transverse myelitis associated with optic neuritis, typically bilateral. Multiple sclerosis is in fact the main differential diagnosis

  14. The ''ATOS'' experimental device

    International Nuclear Information System (INIS)

    Belyaev, V.A.; Dorovskij, A.P.; Dubrovin, M.M.; Khlopkin, A.N.

    1980-08-01

    This paper contains a brief description of the ATOS experimental device at the I.V. Kurchatov Institute, Moscow, USSR, which has been designed in accordance with the merged beam principle to investigate collisions between heavy atomic particles and multiply-charged ions of impurity elements - following the programme of the Joint IFRC/INDC Subcommittee on Atomic and Molecular Data for Fusion

  15. Liver Cell Culture Devices

    NARCIS (Netherlands)

    Andria, B.; Bracco, A.; Cirino, G.; Chamuleau, R. A. F. M.

    2010-01-01

    In the last 15 years many different liver cell culture devices, consisting of functional liver cells and artificial materials, have been developed. They have been devised for numerous different applications, such as temporary organ replacement (a bridge to liver transplantation or native liver

  16. A Medical Delivery Device

    DEFF Research Database (Denmark)

    2010-01-01

    The present invention relates to a medical delivery device comprising at least two membrane electrode assembly units each of which comprises three layers: an upper and a lower electrode and a selective ionic conductive membrane provided there-between. At least one of the three layers are shared...

  17. Single Value Devices

    NARCIS (Netherlands)

    Mader, Angelika H.; Dertien, Edwin Christian; Reidsma, Dennis

    2011-01-01

    We live in a world of continuous information overflow, but the quality of information and communication is suffering. Single value devices contribute to the information and communication quality by fo- cussing on one explicit, relevant piece of information. The information is decoupled from a

  18. Power generating device

    Energy Technology Data Exchange (ETDEWEB)

    Onodera, Toshihiro

    1989-05-02

    The existing power generating device consisting of static components only lacks effective measures to utilize solar energy and maintain power generation, hence it is inevitable to make the device much larger and more complicated in order to utilize it as the primary power source for artificial satellites. In view of the above, in order to offer a power generating device useful for the primary power source for satellites which is simple and can keep power generation by solar energy, this invention proposes a power generating device composed of the following elements: (1) a rectangular parallelopiped No. II superconductor plate; (2) a measure to apply a magnetic field to one face of the above superconductor plate; (3) a measure to provide a temperature difference within the range between the starting temperature and the critical temperature of superconductivity to a pair of faces meeting at right angles with the face to which the magnetic field was applied by the above measure; (4) a measure to provide an electrode on each of the other pair of faces meeting at right angles with the face to which the magnetic field was applied by the above measure and form a closed circuit by connecting the each electrode above to each of a pair of electrodes of the load respectively; and (5) a switching measure which is installed in the closed circuit prepared by the above measure and shuts off the closed circuit when the direction of the electric current running the above closed circuit is reversed. 6 figs.

  19. Standardization of splash device

    Science.gov (United States)

    Fernández Raga, María; Peters, Piet

    2017-04-01

    The erosion is a complex process that has been studied extensively by numerous researchers, requiring a prolongued time effort and a large economic investment. To be effective, the measurements of erosion should be precise, controlled and replicable, and to assure efectiveness, measurement devices of erosion should be properly designed, constructed, well calibrated and also they should be operated by a trained person (Stroosnijder, 2005). Because researchers try to improve old devices, the equipment is constantly being redesigned, making the measurements not comparable and furthermore, producing a lack of available standarized device. The lack of standardization of erosion equipment is more obvious in the case of the local splash erosion, where the nature of the process makes very difficult to isolate its effects. In this article we compare the results obtained from five of the most common splash erosion devices (selected from more than 16 different currently types), under the same rain conditions, with the objective of facilitate the standardization of the method that will be more easy to build, minimizing the error. A set of six splash devices were setted in well known positions under simulated rain, to measured the differences, among devices and the accuracy of the data recovered after 10 minutes of rainfall simulation under different intensities (from 60 to 130 mm/h). The rainfall simulator of Wageningen was used, using sand as splash erosion source. Differences in the infiltration were also measured, and a calibration of sizes and speeds of the raindrops was done using the photography method (Hamidreza-Sadeghi et al., 2013). The splash devices selected for this study were unbounded splash devices (like the funnel, the cup (Fernandez-Raga et al., 2010) and the splash flume (Jomaa et al., 2010)), and bounded devices that allow the calculation of splash rate, (like the new cup (Scholten et al., 2011) and the Morgan tray). The behaviour of different splash devices

  20. Internal inspection devices

    International Nuclear Information System (INIS)

    1982-01-01

    In order to evaluate the possibilities and limits of using specific endoscopes, the design and performance of rigid and flexible endoscopes are studied. The results show on the one hand the physical conditions setting a limit to the applicability of a certain device, and on the other indicate possible ways of improving and modifying given devices so as to adapt them to the special requirements of current testing standards. Based on theoretical and practical experience, proposals for improvements are made. For rigid endoscopes, e.g., additional equipment has been developed and is described in detail, allowing hitherto existing problems to be solved, thus enlarging the range of employment and enhancing and improving the information to be gained by testing using endoscopes. (orig./RW) [de

  1. Fractional-order devices

    CERN Document Server

    Biswas, Karabi; Caponetto, Riccardo; Mendes Lopes, António; Tenreiro Machado, José António

    2017-01-01

    This book focuses on two specific areas related to fractional order systems – the realization of physical devices characterized by non-integer order impedance, usually called fractional-order elements (FOEs); and the characterization of vegetable tissues via electrical impedance spectroscopy (EIS) – and provides readers with new tools for designing new types of integrated circuits. The majority of the book addresses FOEs. The interest in these topics is related to the need to produce “analogue” electronic devices characterized by non-integer order impedance, and to the characterization of natural phenomena, which are systems with memory or aftereffects and for which the fractional-order calculus tool is the ideal choice for analysis. FOEs represent the building blocks for designing and realizing analogue integrated electronic circuits, which the authors believe hold the potential for a wealth of mass-market applications. The freedom to choose either an integer- or non-integer-order analogue integrator...

  2. Radiation detection device

    International Nuclear Information System (INIS)

    Peschmann, Kristian.

    1982-01-01

    A radiation detector suitable for use in computer tomography device has an ionization chamber which comprises a high voltage electrode, a collector electrode, a high voltage source having two terminals, one connected to the high voltage electrode, current measuring means having two terminals, one connected to the high voltage source and the other to the collector electrode, and an auxilliary electrode near and parallel to the entrance window of the device, having one adjacent to the high voltage electrode and the other adjacent but not connected to the collector electrode. The auxilliary electrode is connected to the high voltage source. In this way the electric field between the high voltage and collector electrodes is made homogeneous in the vicinity of the auxilliary electrode, improving the measuring speed of the detector

  3. Atherectomy devices: technology update

    Directory of Open Access Journals (Sweden)

    Akkus NI

    2014-12-01

    Full Text Available Nuri I Akkus,1 Abdulrahman Abdulbaki,1 Enrique Jimenez,2 Neeraj Tandon2 1Department of Cardiology, Louisiana State University Health Sciences Center Shreveport, Shreveport, LA, USA; 2Department of Cardiology, Overton Brooks VA Medical Center, Shreveport, LA, USA Abstract: Atherectomy is a procedure which is performed to remove atherosclerotic plaque from diseased arteries. Atherosclerotic plaques are localized in either coronary or peripheral arterial vasculature and may have different characteristics depending on the texture of the plaque. Atherectomy has been used effectively in treatment of both coronary and peripheral arterial disease. Atherectomy devices are designed differently to either cut, shave, sand, or vaporize these plaques and have different indications. In this article, current atherectomy devices are reviewed. Keywords: coronary artery disease, peripheral arterial disease

  4. Support and maneuvering device

    Science.gov (United States)

    Wood, R.L.

    1987-03-23

    A support and maneuvering device includes an elongated flexible inflatable enclosure having a fixed end and a movable end. The movable end is collapsible toward the fixed end to a contracted position when the enclosure is in a noninflated condition. Upon inflation, the movable end is movable away from the fixed end to an extended position. The movable end includes means for mounting an article such as a solar reflector thereon. The device also includes a plurality of position controlling means disposed about the movable end to effect adjusting movement of portions thereof by predetermined amounts and for controlling an angle at which the article disposed at the movable end is oriented. The plurality of position controlling means limits a suitable number degrees of freedom of the movable end for transmitting a steering motion thereto and for controlling the position thereof. 9 figs.

  5. Microelectromechanical reprogrammable logic device

    Science.gov (United States)

    Hafiz, M. A. A.; Kosuru, L.; Younis, M. I.

    2016-01-01

    In modern computing, the Boolean logic operations are set by interconnect schemes between the transistors. As the miniaturization in the component level to enhance the computational power is rapidly approaching physical limits, alternative computing methods are vigorously pursued. One of the desired aspects in the future computing approaches is the provision for hardware reconfigurability at run time to allow enhanced functionality. Here we demonstrate a reprogrammable logic device based on the electrothermal frequency modulation scheme of a single microelectromechanical resonator, capable of performing all the fundamental 2-bit logic functions as well as n-bit logic operations. Logic functions are performed by actively tuning the linear resonance frequency of the resonator operated at room temperature and under modest vacuum conditions, reprogrammable by the a.c.-driving frequency. The device is fabricated using complementary metal oxide semiconductor compatible mass fabrication process, suitable for on-chip integration, and promises an alternative electromechanical computing scheme. PMID:27021295

  6. Dielectrokinetic chromatography devices

    Science.gov (United States)

    Chirica, Gabriela S; Fiechtner, Gregory J; Singh, Anup K

    2014-12-16

    Disclosed herein are methods and devices for dielectrokinetic chromatography. As disclosed, the devices comprise microchannels having at least one perturber which produces a non-uniformity in a field spanning the width of the microchannel. The interaction of the field non-uniformity with a perturber produces a secondary flow which competes with a primary flow. By decreasing the size of the perturber the secondary flow becomes significant for particles/analytes in the nanometer-size range. Depending on the nature of a particle/analyte present in the fluid and its interaction with the primary flow and the secondary flow, the analyte may be retained or redirected. The composition of the primary flow can be varied to affect the magnitude of primary and/or secondary flows on the particles/analytes and thereby separate and concentrate it from other particles/analytes.

  7. Cold nuclear fusion device

    International Nuclear Information System (INIS)

    Ogino, Shinji.

    1991-01-01

    Selection of cathode material is a key to the attainment of cold nuclear fusion. However, there are only few reports on the cathode material at present and an effective development has been demanded. The device comprises an anode and a cathode and an electrolytic bath having metal salts dissolved therein and containing heavy water in a glass container. The anode is made of gold or platinum and the cathode is made of metals of V, Sr, Y, Nb, Hf or Ta, and a voltage of 3-25V is applied by way of a DC power source between them. The metal comprising V, Sr, Y, Nb, Hf or Ta absorbs deuterium formed by electrolysis of heavy water effectively to cause nuclear fusion reaction at substantially the same frequency and energy efficiency as palladium and titanium. Accordingly, a cold nuclear fusion device having high nuclear fusion generation frequency can be obtained. (N.H.)

  8. Remote controlled transport device

    International Nuclear Information System (INIS)

    Nakahira, Masataka; Oka, Kiyoshi; Ito, Akira; Tada, Eisuke; Sato, Masaki

    1998-01-01

    The present invention provides a device for transporting equipments for maintenance and parts between a maintenance port and a facility for maintenance by remote control in a radioactive material handling facility such as a nuclear power plant. Namely, a power supply bus bar is disposed along a transferring path in order to supply power to a transporting means, and is divided into every region having a predetermined length. Each of the power supply bus bar regions is controlled for the power supply by a control device. Accordingly, the transporting means can be moved and driven successively being independent on every power supply bus bar region. Accordingly, a plurality of transporting means can be operated independently in a transferring path without laying around power cables and control signal cables. (I.S.)

  9. Reactor power control device

    International Nuclear Information System (INIS)

    Ishii, Yoshihiko; Arita, Setsuo; Miyamoto, Yoshiyuki; Fukazawa, Yukihisa; Ishii, Kazuhiko

    1998-01-01

    The present invention provides a reactor power control device capable of enhancing an operation efficiency while keeping high reliability and safety in a BWR type nuclear power plant. Namely, the device of the present invention comprises (1) a means for inputting a set value of a generator power and a set value of a reactor power, (2) a means for controlling the reactor power to either smaller one of the reactor power corresponding to the set value of the generator power and the set value of the reactor power. With such procedures, even if the nuclear power plant is set so as to operate it to make the reactor power 100%, when the generator power reaches the upper limit, the reactor power is controlled with a preference given to the upper limit value of the generator power. Accordingly, safety and reliability are not deteriorated. The operation efficiency of the plant can be improved. (I.S.)

  10. Electromagnetic wave matching device

    International Nuclear Information System (INIS)

    Hirata, Yosuke; Mitsunaka, Yoshika; Hayashi, Ken-ichi; Ito, Yasuyuki.

    1997-01-01

    The present invention provides a matching device capable of increasing an efficiency of combining beams of electromagnetic waves outputted from an output window of a gyrotron which is expected for plasma heating of a thermonuclear reactor and an electromagnetic wave transmission system as high as possible. Namely, an electromagnetic wave matching device reflects beams of electromagnetic waves incident from an inlet by a plurality of phase correction mirrors and combines them to an external transmission system through an exit. In this case, the phase correction mirrors change the phase of the beams of electromagnetic waves incident to the phase correction mirrors by a predetermined amount corresponding to the position of the reflection mirrors. Then, the beams of electromagnetic waves outputted, for example, from a gyrotron can properly be shaped as desired for the intensity and the phase. As a result, combination efficiency with the transmission system can be increased. (I.S.)

  11. Gas processing device

    International Nuclear Information System (INIS)

    Kobayashi, Yoshihiro; Seki, Eiji.

    1991-01-01

    State of electric discharge is detected based on a gas pressure in a sealed container and a discharging current flowing between both of electrodes. When electric arc discharges occur, introduction of gases to be processed is stopped and a voltage applied to both of the electrodes is interrupted. Then, when the gas pressure in the sealed container is lowered to a predetermined value, a power source voltage is applied again to both of the electrodes to recover glow discharges, and the introduction of the gas to be processed is started. With such steps, even if electric arc discharges occur, they are eliminated automatically and, accordingly, normal glow discharges can be recovered, to prevent failures of the device due to electric arc discharges. The glow discharges are recovered automatically without stopping the operation of the gas processing device, and gas injection and solidification processing can be conducted continuously and stably. (T.M.)

  12. Reactor control device

    International Nuclear Information System (INIS)

    Fukami, Haruo; Morimoto, Yoshinori.

    1981-01-01

    Purpose: To operate a reactor always with safety operation while eliminating the danger of tripping. Constitution: In a reactor control device adapted to detect the process variants of a reactor, control a control rod drive controlling system based on the detected signal to thereby control the driving the control rods, control the reactor power and control the electric power generated from an electric generator by the output from the reactor, detection means is provided for the detection of the electric power from said electric generator, and a compensation device is provided for outputting control rod driving compensation signals to the control rod driving controlling system in accordance with the amount of variation in the detected value. (Seki, T.)

  13. Control rod control device

    International Nuclear Information System (INIS)

    Seiji, Takehiko; Obara, Kohei; Yanagihashi, Kazumi

    1998-01-01

    The present invention provides a device suitable for switching of electric motors for driving each of control rods in a nuclear reactor. Namely, in a control rod controlling device, a plurality of previously allotted electric motors connected in parallel as groups, and electric motors of any selected group are driven. In this case, a voltage of not driving predetermined selected electric motors is at first applied. In this state an electric current supplied to the circuit of predetermined electric motors is detected. Whether integration or failure of a power source and the circuit of the predetermined electric motors are normal or not is judged by the detected electric current supplied. After they are judged normal, the electric motors are driven by a regular voltage. With such procedures, whether the selected circuit is normal or not can be accurately confirmed previously. Since the electric motors are not driven just at the selected time, the control rods are not operated erroneously. (I.S.)

  14. TPA device for demonstration

    International Nuclear Information System (INIS)

    1980-02-01

    The TPA (torus plasma for amature) is a small race-trac type device made by the technical service division to demonstrate basic properties of plasma such as electron temperature, conductivity, effect of helical field for toroidal drift, and shape of plasma in mirror and cusp magnetic field in linear section. The plasmas are produced by RF discharge (-500W) and/or DC discharge (-30 mA) within glass discharge tube. Where major radius is 50 cm, length of linear section is 50 cm, toroidal magnetic field is 200 gauss. The device has been designed to be compact with only 100 V power source (-3.2 KW for the case without helical field) and to be full automatic sequence of operation. (author)

  15. Tire deflation device

    Science.gov (United States)

    Barker, Stacey G [Idaho Falls, ID

    2010-01-05

    A tire deflation device includes (1) a component having a plurality of bores, (2) a plurality of spikes removably insertable into the plurality of bores and (3) a keeper within each among the plurality of bores, the keeper being configured to contact a sidewall surface of a spike among the plurality of spikes and to exert force upon the sidewall surface. In an embodiment, the tire deflation device includes (a) a component including a bore in a material, the bore including a receiving region, a sidewall surface and a base surface, (b) a channel extending from the sidewall surface into the material, (c) a keeper having a first section housed within the channel and a second section which extends past the sidewall surface into the receiving region, and (d) a spike removably insertable into the bore.

  16. Microelectromechanical reprogrammable logic device

    KAUST Repository

    Hafiz, Md Abdullah Al

    2016-03-29

    In modern computing, the Boolean logic operations are set by interconnect schemes between the transistors. As the miniaturization in the component level to enhance the computational power is rapidly approaching physical limits, alternative computing methods are vigorously pursued. One of the desired aspects in the future computing approaches is the provision for hardware reconfigurability at run time to allow enhanced functionality. Here we demonstrate a reprogrammable logic device based on the electrothermal frequency modulation scheme of a single microelectromechanical resonator, capable of performing all the fundamental 2-bit logic functions as well as n-bit logic operations. Logic functions are performed by actively tuning the linear resonance frequency of the resonator operated at room temperature and under modest vacuum conditions, reprogrammable by the a.c.-driving frequency. The device is fabricated using complementary metal oxide semiconductor compatible mass fabrication process, suitable for on-chip integration, and promises an alternative electromechanical computing scheme.

  17. Radioactive waste processing device

    International Nuclear Information System (INIS)

    Seki, Shuji.

    1992-01-01

    Liquid wastes are supplied to a ceramic filter to conduct filtration. In this case, a device for adding a powdery inorganic ion exchanger is disposed to the upstream of the ceramic filter. When the powdery inorganic ion exchanger is charged to the addition device, it is precoated to the surface of the ceramic filter, to conduct separation of suspended matters and separation of ionic nuclides simultaneously. Liquid wastes returned to a collecting tank are condensed while being circulated between the ceramic filter and the tank and then contained in a condensation liquid waste tank. With such a constitution, both of radioactive nuclides accompanied by suspended matters in the radioactive liquid wastes and ionic nuclides can be captured efficiently. (T.M.)

  18. Localized environment characterization device

    KAUST Repository

    Alzain, Hashim

    2016-07-21

    Various apparatuses and methods are provided for measuring the likely environmental impact of a particular geographic location on power generation properties of potential solar installations at the particular location. In an example embodiment of one such apparatus, a measurement device is provided. The measurement device includes a base portion comprising a base frame element disposed on a plurality of supporting legs, and a top panel comprising a series of connected members and one or more measurement modules whose planar dimensions are defined by the series of connected members. The top panel is connected to the base portion by a joint such that the top panel can rotate about the joint, and a panel support element is configured to fasten the top panel immovably at a desired degree of rotation in relation to the base portion.

  19. Internal pump monitoring device

    International Nuclear Information System (INIS)

    Kurosaki, Toshikazu.

    1996-01-01

    In the present invention, a thermometer is disposed at the upper end of an internal pump casing of a coolant recycling system in a BWR type reactor to detect leakage of reactor water thereby ensuring the improvement of reliability of the internal pump. Namely, a thermometer is disposed, which can detect temperature elevation occurred when water in the internal pump leaked from a reactor pressure vessel passes through the gap between a stretch tube and an upper end of the pump casing. Signals from the thermometer are transmitted to a signal processing device by an instrumentation cable. The signal processing device generates an alarm when the temperature signal exceeds a predetermined value and announces that leakage of reactor water occurs in the internal pump. Since the present invention can detect the leakage of the reactor water in the pump casing in an early stage, it can contribute to the improvement of the safety and reliability of the internal pump. (I.S.)

  20. Traversing incore probe device

    International Nuclear Information System (INIS)

    Yoshioka, Michiko.

    1985-01-01

    Purpose: To measure the neutron flux distribution in the reactor core always at a high accuracy. Constitution: A nuclear fission ionizing chamber type detector is disposed at the end of a cable for sending a detection signal of a traversing incore probe device and, further, a gamma-ray ionizing chamber type detector is connected in adjacent therewith and a selection circuit for selecting both of the detection signals and inputting them to a display device is disposed. Then, compensation for the neutron monitors is conducted by the gamma-ray ionizing chamber type detector during normal operation in which control rods are not driven and the positioning is carried out by the nuclear fission ionizing chamber type detector. Furthermore, both of the compensation for the neutron detector and the positioning are carried out by the nuclear fission ionizing chamber type detector upon starting where the control rods are driven. (Sekiya, K.)

  1. Thin film device applications

    CERN Document Server

    Kaur, Inderjeet

    1983-01-01

    Two-dimensional materials created ab initio by the process of condensation of atoms, molecules, or ions, called thin films, have unique properties significantly different from the corresponding bulk materials as a result of their physical dimensions, geometry, nonequilibrium microstructure, and metallurgy. Further, these characteristic features of thin films can be drasti­ cally modified and tailored to obtain the desired and required physical characteristics. These features form the basis of development of a host of extraordinary active and passive thin film device applications in the last two decades. On the one extreme, these applications are in the submicron dimensions in such areas as very large scale integration (VLSI), Josephson junction quantum interference devices, magnetic bubbles, and integrated optics. On the other extreme, large-area thin films are being used as selective coatings for solar thermal conversion, solar cells for photovoltaic conver­ sion, and protection and passivating layers. Ind...

  2. Data processing device

    International Nuclear Information System (INIS)

    Kita, Yoshio.

    1994-01-01

    A data processing device for use in a thermonuclear testing device comprises a frequency component judging section for analog signals, a sample time selection section based on the result of the judgement, a storing memory section for selecting digital data memorized in the sampling time. Namely, the frequency components of the analog signals are detected by the frequency component judging section, and one of a plurality of previously set sampling times is selected by the sampling time selection section based on the result of the judgement of the frequency component judging section. Then, digital data obtained by A/D conversion are read and preliminarily memorized in the storing memory section. Subsequently, the digital data memorized in the sampling time selected by the sampling time selection section are selected and transmitted to a superior computer. The amount of data to be memorized can greatly reduced, to reduce the cost. (N.H.)

  3. Bioanalysis in microfluidic devices.

    Science.gov (United States)

    Khandurina, Julia; Guttman, András

    2002-01-18

    Microfabricated bioanalytical devices (also referred to as laboratory-on-a-chip or micro-TAS) offer highly efficient platforms for simultaneous analysis of a large number of biologically important molecules, possessing great potential for genome, proteome and metabolome studies. Development and implementation of microfluidic-based bioanalytical tools involves both established and evolving technologies, including microlithography, micromachining, micro-electromechanical systems technology and nanotechnology. This article provides an overview of the latest developments in the key device subject areas and the basic interdisciplinary technologies. Important aspects of DNA and protein analysis, interfacing issues and system integration are all thoroughly discussed, along with applications for this novel "synergized" technology in high-throughput separations of biologically important molecules. This review also gives a better understanding of how to utilize these technologies as well as to provide appropriate technical solutions to problems perceived as being more fundamental.

  4. Optically coupled semiconductor device

    Energy Technology Data Exchange (ETDEWEB)

    Kumagaya, Naoki

    1988-11-18

    This invention concerns an optically coupled semiconductor device using the light as input signal and a MOS transistor for the output side in order to control on-off of the output side by the input signal which is insulated from the output. Concerning this sort of element, when a MOS transistor and a load resistance are planned to be accumulated on the same chip, a resistor and control of impurity concentration of the channel, etc. become necessary despite that the only formation of a simple P-N junction is enough, for a solar cell, hence cost reduction thereof cannot be done. In order to remove this defect, this invention offers an optically coupled semiconductor device featuring that two solar cells are connected in reverse parallel between the gate sources of the output MOS transistors and an operational light emitting element is individually set facing a respective solar cell. 4 figs.

  5. Hybrid electroluminescent devices

    Science.gov (United States)

    Shiang, Joseph John; Duggal, Anil Raj; Michael, Joseph Darryl

    2010-08-03

    A hybrid electroluminescent (EL) device comprises at least one inorganic diode element and at least one organic EL element that are electrically connected in series. The absolute value of the breakdown voltage of the inorganic diode element is greater than the absolute value of the maximum reverse bias voltage across the series. The inorganic diode element can be a power diode, a Schottky barrier diode, or a light-emitting diode.

  6. A power measuring device

    International Nuclear Information System (INIS)

    As, R. van.

    1985-01-01

    As a part of the klystron test facility of the Dutch NIKHEF-K accelerator, a sensitive power measuring device has been built. The high-frequency power of a klystron is stored in a water-cooled dummy load. Using a microcomputer, the increase of the water temperature and the water flow rate are transformed to a digital indication of the klystron power. (Auth.)

  7. Temperature measuring device

    International Nuclear Information System (INIS)

    Brixy, H.

    1977-01-01

    The temperature measuring device is equipped with an electric resistor installed within a metal shroud tube so as to be insulated from it, the noise voltage of which resistor is fed to a measuring unit. The measuring junctions of one or two thermocouples are connected with the electric resistor and the legs of one or both thermocouples can be connected to the measuring unit by means of a switch. (orig.) [de

  8. Plastic photovoltaic devices

    OpenAIRE

    Niyazi Serdar Sariciftci

    2004-01-01

    The development of organic, polymer-based photovoltaic elements has introduced the possibility of obtaining cheap and easy-to-produce energy from light. Photoinduced electron transfer from donor-type semiconducting polymers onto acceptor-type polymers or molecules, such as C60, is the basic phenomenon utilized in these photovoltaic devices. This process mimics the early photo-effects in natural photosynthesis. The polymeric semiconductors combine the photoelectrical properties of inorganic se...

  9. Incore inspection device

    International Nuclear Information System (INIS)

    Ogisu, Tatsuki; Taguchi, Kosei.

    1995-01-01

    The device of the present invention can inspect surfaces of equipments in reactor water in a nuclear reactor in a state of atmospheric air. Namely, an inspection device is movable forwardly and backwardly in a water-proof vessel. An annular sucker with pleats is disposed to the outer side of a lid of the water-proof vessel. A television camera for an under water monitoring is disposed to the inner side of the lid of the water-proof vessel by way of a partitioning wall with lid. Transferring screws are disposed at the back and on the side of the water-proof vessel. In the device having such a constitution, (1) the inside of the water-proof vessel is at first made water-tight by closing the partitioning wall with lid, (2) the back and the side screws are operated by the guide of the underwater monitoring television camera, to transfer the water-proof vessel to the surface of the reactor core to be inspected, (3) the annular sucker with pleats is urged on the surface to be inspected by the back screw, to fix the water-proof vessel, (4) reactor water in a space of the annular sucker with pleats is discharged and replaced with air, and (5) the lid of the partition wall with lid is opened and the inspection device is disposed at a position of the underwater monitoring television camera, to inspect the surface to be inspected in a state of atmospheric air. (I.S.)

  10. Gas dynamic laser device

    International Nuclear Information System (INIS)

    Born, G.

    1975-01-01

    The gas dynamic laser device is provided with an expansion chamber arranged between a heating chamber for the CO-gas and the resonance chamber. The expansion chamber is initially evacuated for producing a rarefaction wave. Between the heating chamber and the expansion chamber there are arranged rapid release means such as a valve or a diaphragm. Pressure recovering means are connected to the other side of the resonance chamber

  11. Temperature measuring device

    Energy Technology Data Exchange (ETDEWEB)

    Lauf, R.J.; Bible, D.W.; Sohns, C.W.

    1999-10-19

    Systems and methods are described for a wireless instrumented silicon wafer that can measure temperatures at various points and transmit those temperature readings to an external receiver. The device has particular utility in the processing of semiconductor wafers, where it can be used to map thermal uniformity on hot plates, cold plates, spin bowl chucks, etc. without the inconvenience of wires or the inevitable thermal perturbations attendant with them.

  12. Spintronics in nanoscale devices

    CERN Document Server

    Hedin, Eric R

    2013-01-01

    By exploiting the novel properties of quantum dots and nanoscale Aharonov-Bohm rings together with the electronic and magnetic properties of various semiconductor materials and graphene, researchers have conducted numerous theoretical and computational modeling studies and experimental tests that show promising behavior for spintronics applications. Spin polarization and spin-filtering capabilities and the ability to manipulate the electron spin state through external magnetic or electric fields have demonstrated the promise of workable nanoscale devices for computing and memory applications.

  13. Fluctuations in quantum devices

    Directory of Open Access Journals (Sweden)

    H.Haken

    2004-01-01

    Full Text Available Logical gates can be formalized by Boolean algebra whose elementary operations can be realized by devices that employ the interactions of macroscopic numbers of elementary excitations such as electrons, holes, photons etc. With increasing miniaturization to the nano scale and below, quantum fluctuations become important and can no longer be ignored. Based on Heisenberg equations of motion for the creation and annihilation operators of elementary excitations, I determine the noise sources of composite quantum systems.

  14. Memristor: the illusive device

    KAUST Repository

    Salama, Khaled N.

    2012-05-03

    The memristor (M) is considered to be the fourth two-terminal passive element in electronics, alongside the resistor (R), the capacitor (C), and the inductor (L). Its existence was postulated in 1971 but its first implementation was reported in 2008. Where was it hiding all that time and what can we do with it? Come and learn how the memristor completes the roster of electronic devices much like a missing particle that physicists seek to complete their tableaus.

  15. Biomolecular detection device

    Science.gov (United States)

    Huo, Qisheng [Albuquerque, NM; Liu, Jun [Albuquerque, NM

    2008-10-21

    A device for detecting and measuring the concentration of biomolecules in solution, utilizing a conducting electrode in contact with a solution containing target biomolecules, with a film with controllable pore size distribution characteristics applied to at least one surface of the conducting electrode. The film is functionalized with probe molecules that chemically interact with the target biomolecules at the film surface, blocking indicator molecules present in solution from diffusing from the solution to the electrode, thereby changing the electrochemical response of the electrode.

  16. Electronic portal imaging devices

    International Nuclear Information System (INIS)

    Lief, Eugene

    2008-01-01

    The topics discussed include, among others, the following: Role of portal imaging; Port films vs. EPID; Image guidance: Elekta volume view; Delivery verification; Automation tasks of portal imaging; Types of portal imaging (Fluorescent screen, mirror, and CCD camera-based imaging; Liquid ion chamber imaging; Amorpho-silicon portal imagers; Fluoroscopic portal imaging; Kodak CR reader; and Other types of portal imaging devices); QA of EPID; and Portal dosimetry (P.A.)

  17. Fuel assembly manufacturing device

    International Nuclear Information System (INIS)

    Picard, P.; Villaeys, R.

    1995-01-01

    The device comprises a central support on which the frame is mounted, a magazine which supports the fuel rods in passages aligned with those in the frame and a traction assembly on the opposite side of the magazine and including an array of pull rods designed to be advanced through the passages in the frame, to grip respective fuel rods in magazine and to pull those rods into the passages on the return stroke. 13 figs

  18. High speed heterostructure devices

    CERN Document Server

    Beer, Albert C; Willardson, R K; Kiehl, Richard A; Sollner, T C L Gerhard

    1994-01-01

    Volume 41 includes an in-depth review of the most important, high-speed switches made with heterojunction technology. This volume is aimed at the graduate student or working researcher who needs a broad overview andan introduction to current literature. Key Features * The first complete review of InP-based HFETs and complementary HFETs, which promise very low power and high speed * Offers a complete, three-chapter review of resonant tunneling * Provides an emphasis on circuits as well as devices.

  19. Memristor: the illusive device

    KAUST Repository

    Salama, Khaled N.

    2012-01-01

    The memristor (M) is considered to be the fourth two-terminal passive element in electronics, alongside the resistor (R), the capacitor (C), and the inductor (L). Its existence was postulated in 1971 but its first implementation was reported in 2008. Where was it hiding all that time and what can we do with it? Come and learn how the memristor completes the roster of electronic devices much like a missing particle that physicists seek to complete their tableaus.

  20. Glow discharging device

    International Nuclear Information System (INIS)

    Maeno, Katsuki; Kawasaki, Kozo; Hiratsuka, Hajime; Kawashima, Shuichi.

    1989-01-01

    In a thermonuclear device, etc. impurities adsorbed to inner walls of a vacuum vessel by glow discharge are released to clean the vacuum vessel for preventing intrusion of the impurities into plasmas. The object of the present invention is to minimize the capacity of a power source equipment for the glow discharge device to the least extent. That is, a stabilization resistance is connected in series between each of a plurality of anodes which are inserted and arranged at the inside of a vacuum vessel as a cathode and a power source respectively. The resistance value R is selected so as to satisfy the relation: R < (Vi - Vm)/Ii, in which Vi: glow discharge starting voltage, Vm: glow discharge keeping voltage, Ii: glow discharge starting current. Accordingly, if a voltage is applied from a power source to a plurality of anodes, scattering of electric discharge between the anodes can be suppressed and the effect of voltage drop during discharge by the stabilization resistance can be eliminated. As a result, it is possible to provide an economically advantageous glow discharge device with the capacity for the power source facility being to the least extent. (K.M.)

  1. Rf superconducting devices

    International Nuclear Information System (INIS)

    Hartwig, W.H.; Passow, C.

    1975-01-01

    Topics discussed include (1) the theory of superconductors in high-frequency fields (London surface impedance, anomalous normal surface resistance, pippard nonlocal theory, quantum mechanical model, superconductor parameters, quantum mechanical calculation techniques for the surface, impedance, and experimental verification of surface impedance theories); (2) residual resistance (separation of losses, magnetic field effects, surface resistance of imperfect and impure conductors, residual loss due to acoustic coupling, losses from nonideal surfaces, high magnetic field losses, field emission, and nonlinear effects); (3) design and performance of superconducting devices (design considerations, materials and fabrication techniques, measurement of performance, and frequency stability); (4) devices for particle acceleration and deflection (advantages and problems of using superconductors, accelerators for fast particles, accelerators for particles with slow velocities, beam optical devices separators, and applications and projects under way); (5) applications of low-power superconducting resonators (superconducting filters and tuners, oscillators and detectors, mixers and amplifiers, antennas and output tanks, superconducting resonators for materials research, and radiation detection with loaded superconducting resonators); and (6) transmission and delay lines

  2. Shroud brushing device

    International Nuclear Information System (INIS)

    Sakamaki, Kazuo; Takabayashi, Jun-ichi.

    1996-01-01

    A roller screw is assembled at an axial center of the inside of a device main body. A nut is assembled to the axial center of the roller screw secured so as not to be rotated, and a base is integrally connected to the nut. An air cylinder is pivoted to the base by a pin, and an arm is disposed to a piston rod of the air cylinder. The top end of the arm is secured to a motor case, and a brush is rotated by an electric motor in the motor case. The device main body is suspended into the reactor pressure vessel of a BWR type reactor, and seated on the upper surface of a fuel support metal fitting. The roller screw is rotated to move vertically the arm by way of the nut and the base. The device main body is rotated to rotate the arm. The arm is extended and then the electric motor is driven to rotate the brush thereby polishing the inner surface of the shroud. (I.N.)

  3. Shroud brushing device

    Energy Technology Data Exchange (ETDEWEB)

    Sakamaki, Kazuo; Takabayashi, Jun-ichi

    1996-07-12

    A roller screw is assembled at an axial center of the inside of a device main body. A nut is assembled to the axial center of the roller screw secured so as not to be rotated, and a base is integrally connected to the nut. An air cylinder is pivoted to the base by a pin, and an arm is disposed to a piston rod of the air cylinder. The top end of the arm is secured to a motor case, and a brush is rotated by an electric motor in the motor case. The device main body is suspended into the reactor pressure vessel of a BWR type reactor, and seated on the upper surface of a fuel support metal fitting. The roller screw is rotated to move vertically the arm by way of the nut and the base. The device main body is rotated to rotate the arm. The arm is extended and then the electric motor is driven to rotate the brush thereby polishing the inner surface of the shroud. (I.N.)

  4. Left Ventricular Assist Devices

    Directory of Open Access Journals (Sweden)

    Khuansiri Narajeenron

    2017-04-01

    Full Text Available Audience: The audience for this classic team-based learning (cTBL session is emergency medicine residents, faculty, and students; although this topic is applicable to internal medicine and family medicine residents. Introduction: A left ventricular assist device (LVAD is a mechanical circulatory support device that can be placed in critically-ill patients who have poor left ventricular function. After LVAD implantation, patients have improved quality of life.1 The number of LVAD patients worldwide continues to rise. Left-ventricular assist device patients may present to the emergency department (ED with severe, life-threatening conditions. It is essential that emergency physicians have a good understanding of LVADs and their complications. Objectives: Upon completion of this cTBL module, the learner will be able to: 1 Properly assess LVAD patients’ circulatory status; 2 appropriately resuscitate LVAD patients; 3 identify common LVAD complications; 4 evaluate and appropriately manage patients with LVAD malfunctions. Method: The method for this didactic session is cTBL.

  5. Failed fuel detection device

    International Nuclear Information System (INIS)

    Doi, Akira.

    1994-01-01

    The device of the present invention concerns a failed fuel detection device for a nuclear reactor, such as an FBR type reactor, using electroconductive coolants. A sampling port is disposed at the upper portion of the fuel assembly so as to cover the assembly, so that coolants in the fuel assembly are sampled to improve a device for detecting fuel failure. That is, when coolants in the fuel assembly are sampled from the sampling port, the flow of electroconductive coolants in an sampling tube is detected by a flowmeter, to control an electromagnetic pump. The flow of electroconductive coolants is stopped against the waterhead pressure and dynamic pressure of the conductive coolants, and a predetermined amount of the coolants is pumped up to the sampling tank. Gas is supplied to the pumped up coolants so that fissile products are transferred from the coolants to a gas phase. Radiation in the gas in a gas recycling system is measured to detect presence of fuel failure. (I.S.)

  6. Reactor water sampling device

    International Nuclear Information System (INIS)

    Sakamaki, Kazuo.

    1992-01-01

    The present invention concerns a reactor water sampling device for sampling reactor water in an in-core monitor (neutron measuring tube) housing in a BWR type reactor. The upper end portion of a drain pipe of the reactor water sampling device is attached detachably to an in-core monitor flange. A push-up rod is inserted in the drain pipe vertically movably. A sampling vessel and a vacuum pump are connected to the lower end of the drain pipe. A vacuum pump is operated to depressurize the inside of the device and move the push-up rod upwardly. Reactor water in the in-core monitor housing flows between the drain pipe and the push-up rod and flows into the sampling vessel. With such a constitution, reactor water in the in-core monitor housing can be sampled rapidly with neither opening the lid of the reactor pressure vessel nor being in contact with air. Accordingly, operator's exposure dose can be reduced. (I.N.)

  7. Rubber glove wearing device

    International Nuclear Information System (INIS)

    Nozaki, Tatsuo; Takada, Kaoru.

    1994-01-01

    Rubber groves are attached each to an upper end of a glove putting vessel having an air-sucking hole on the bottom by enlarging an opening end of the rubber glove and turning back the inside to the outside. When the sucking device is operated, air in the glove putting device is sucked and the rubber glove is expanded by an atmospheric pressure. After expansion of the rubber glove to some extent, the sucking device is stopped, and presence or absence of failures of the rubber glove is confirmed by shrinkage of the rubber glove and by an indication value of a pressure gauge for detecting the pressure change in the vessel. Then, a hand is inserted to the expanded rubber glove, and a detaching switch in the vessel is pushed by a finger tip. A detaching piece at the upper end of the vessel is protruded outwardly to enlarge the turned-back portion of the rubber glove to easily release the rubber glove from the putting vessel, and the rubber glove is put on. This enables to wear the rubber glove and conduct failure test simultaneously. Further, a user can put on the rubber glove without touching the outside of the rubber glove. (I.N.)

  8. Radiation ray measuring device

    International Nuclear Information System (INIS)

    Maekawa, Tatsuyuki; Ida, Masaki.

    1997-01-01

    The present invention provides a chained-radiation ray monitoring system which can be applied to an actual monitoring system of a nuclear power plant or the like. Namely, this device comprises a plurality of scintillation detectors. Each of the detectors has two light take-out ports for emitting light corresponding to radiation rays irradiated from the object of the measurement to optical fibers. In addition, incident light from the optical fiber by way of one of the light take-out optical ports is transmitted to the other of the ports and sent from the other optical port to the fibers. Plurality sets of measuring systems are provided in which each of the detectors are disposed corresponding to a plurality of objects to be measured. A signal processing device is (1) connected with optical fibers of plurality sets of measuring systems in conjunction, (2) detects the optical pulses inputted from the optical fibers to identify the detector from which the optical pulses are sent and (3) measures the amount of radiation rays detected by the identified detector. As a result, the device of the present invention can form a measuring system with redundancy. (I.S.)

  9. Incore instrument device

    International Nuclear Information System (INIS)

    Sakima, Naoki

    1996-01-01

    An incore instrument device has an integrally disposed touch panel having a function of displaying an operation indication method such as for setting of conditions for incore measurement and information processing and results of the incore measurement and a function capable of conducting operation indication such as for setting conditions and information processing for incore measurement relative to a control section upon touching an information position on a displayed information. In addition, an information processing section comprising a man-machine function program formed so as to recognize the content of the operation indication for the incore measurement by touching and let the control section to conduct it is disposed to the outside by way of a communication interface. In addition, a programming device is disposed for forming and rewriting the program of the man-machine function relative to the information processing section. Then, when various indication operations are conducted upon performing incore measurement, a view point can be concentrated to one predetermined point thereby enabling to improve the operationability without danger. In addition, the programming of the man-machine function does not apply unnecessary load to the control section in the incore instrumentation device. (N.H.)

  10. Coolant leakage detecting device

    International Nuclear Information System (INIS)

    Yamauchi, Kiyoshi; Kawai, Katsunori; Ishihara, Yoshinao.

    1995-01-01

    The device of the present invention judges an amount of leakage of primary coolants of a PWR power plant at high speed. Namely, a mass of coolants contained in a pressurizer, a volume controlling tank and loop regions is obtained based on a preset relational formula and signals of each of process amount, summed up to determine the total mass of coolants for every period of time. The amount of leakage for every period of time is calculated by a formula of Karman's filter based on the total mass of the primary coolants for every predetermined period of time, and displays it on CRT. The Karman's filter is formed on every formula for several kinds of states formed based on the preset amount of the leakage, to calculate forecasting values for every mass of coolants. An adaptable probability for every preset leakage amount is determined based on the difference between the forecast value and the observed value and the scattering thereof. The adaptable probability is compared with a predetermined threshold value, which is displayed on the CRT. This device enables earlier detection of leakage and identification of minute leakage amount as compared with the prior device. (I.S.)

  11. Stud manipulating device

    International Nuclear Information System (INIS)

    Bunyan, T.W.

    1980-01-01

    A device for inserting and removing studs from bores in a workpiece, for example a nuclear reactor vessel, comprises manipulating devices for operating on individual studs, each capable of tensioning a stud slackening a working nut on the stud, and subsequently removing the stud from the bore. A ring has dogs which can engage working nut recesses to interlock with the nut against relative rotation. Motors coupled to the ring rotate the working nut. A top nut is coupled to the motors to rotate the nut and screw it onto the stud. The top nut with other device parts can be raised and lowered on a tube by a hydraulic actuator. A hydraulic load cell between the top nut and a stool on the workpiece is pressurised to tension the stud by means of the top nut and thus facilitate rotation of the working nut when tightening or slackening. A dog clutch mechanism engages a stud end fitting against relative axial and rotational movement. The mechanism is raised and lowered on a guide member by an actuator. The mechanism has a tubular member and the drive coupling for the motors to the top nut includes a tubular member. Tubular members carry teeth which are engaged when the top nut is raised and the clutch mechanism is lowered, to provide a coupling between the motors and the mechanism for rotating the stud. (U.K.)

  12. Liquid metal purification device

    International Nuclear Information System (INIS)

    Sakai, Takao; Shimoyashiki, Shigehiro.

    1992-01-01

    The device of the present invention concerns a liquid metal purification device for removing and purifying impuries in liquid metal sodium used as coolants of an FBR type reactor. A vessel having a group of pipes made of hydrogen permeable metal at the inside thereof is disposed to the inlet pipeline of a cold trap. The group of hydrogen permeable metal pipes is connected to an exhaust pipe and a vacuum pump, so that the inside of the pipes is exhausted. Liquid metal sodium branched from the main pipeline of a coolant system passes through the outer side of the group of the hydrogen permeable metal pipes. In this cae, hydrogen contained as impurities in the liquid metal sodium diffuses and permeates the hydrogen permeation metal pipes and enters into the pipe group and is discharged out of the system by the vacuum pump. This can mitigate the hydrogen removing burden of the cold trap, to extend the device life time. (I.N.)

  13. Pruning devices in 1995

    International Nuclear Information System (INIS)

    Mutikainen, A.

    1995-01-01

    This bulletin describes the market situation in April 1995 in Finland concerning devices suitable for silvicultural pruning in forestry. The review is based on the responses to a questionnaire sent to manufacturers and importers. Manually operated pruning devices, relying entirely on muscle power, were manufactured by six companies. There were four models each of branch saws and branch cutters and two models of branch blades. Motorised pruning devices, with the branch-severing power supplied by a combustion engine, battery or a power unit were manufactured by five companies. There were twelve models in all. The amount of pruning done in Finland has diminished year by year from the peak years of 1988-1989 when ca. 13000 hectares were pruned. In 1993 the corresponding figure was 5290 hectares of which 3930 hectares applied to private, non-industrial forestry. One contributing factor to this fall may be seen in the changes that have occurred in forest improvement regulations. The annual target set in the Forest 2000 program is for 20000 hectares to be pruned. (author)

  14. Photoelectric transfer device

    Energy Technology Data Exchange (ETDEWEB)

    Shinomiya, Takuji; Murao, Fumihide

    1987-12-07

    Concerning the conventional photoelectric transfer device, a short-circuit current of photodiodes is switched over with MOS transistors. However, since the backgate voltage of the MOS transistor which is to be used as the switching element, is provided by the source voltage, the leakage current between the backgate and the source/drain/ channel is great and due to this leakage current, errors occur in the photoelectric transfer power output. Especially, when the leakage current of the photodiodes is small, the error becomes large. In order to solve the above problem, this invention aims at offering a photoelectric transfer device which can provide the high precision photoelectric transfer even the short-circuit current generated in the photodiodes is small and proposes a photoelectric transfer device in which the backgate voltage of the MOS transistor switching over the short-circuit current of the photodiodes is made equal to the electric potential of the mutually connected anodes (or cathodes) of the photodiodes. (3 figs)

  15. DeviceNet-based device-level control in SSRF

    CERN Document Server

    Leng Yong Bin; Lu Cheng Meng; Miao Hai Feng; Liu Song Qiang; Shen Guo Bao

    2002-01-01

    The control system of Shanghai Synchrotron Radiation Facility is an EPICS-based distributed system. One of the key techniques to construct the system is the device-level control. The author describes the design and implementation of the DeviceNet-based device controller. A prototype of the device controller was tested in the experiments of magnet power supply and the result showed a precision of 3 x 10 sup - sup 5

  16. Novel Concepts for Device to Device Communication using Network Coding

    DEFF Research Database (Denmark)

    Pahlevani, Peyman; Hundebøll, Martin; Pedersen, Morten Videbæk

    2014-01-01

    Device-to-device communication is currently a hot research topic within 3GPP. Even though D2D communication has been part of previous ad hoc, meshed and sensor networks proposals, the main contribution by 3GPP is that the direct communication among two devices is carried out over a dynamically as...

  17. Fingerprinting 802.11 Devices

    National Research Council Canada - National Science Library

    Ellch, Jonathan P

    2006-01-01

    The research presented in this thesis provides the reader with a set of algorithms and techniques that enable the user to remotely determine what chipset and device driver an 802.11 device is using...

  18. Deformable paper origami optoelectronic devices

    KAUST Repository

    He, Jr-Hau; Lin, Chun-Ho

    2017-01-01

    Deformable optoelectronic devices are provided, including photodetectors, photodiodes, and photovoltaic cells. The devices can be made on a variety of paper substrates, and can include a plurality of fold segments in the paper substrate creating a

  19. An introduction to electrooptic devices

    CERN Document Server

    Kaminow, Ivan P

    1974-01-01

    An Introduction to Electrooptic Devices aims to present an introduction to the electrooptic effect and to summarize work on devices employing the electrooptic effect. The book provides the necessary background in classical crystal optics. The text then discusses topics including crystal symmetry, the tensor description of linear dielectric properties, propagation in anisotropic media, and passive crystal optic devices. The book also describes the phenomenological description of tensor nonlinear dielectric properties of crystals, with emphasis on the electrooptic effect; device design and appli

  20. Case outsourcing medical device reprocessing.

    Science.gov (United States)

    Haley, Deborah

    2004-04-01

    IN THE INTEREST OF SAVING MONEY, many hospitals are considering extending the life of some single-use medical devices by using medical device reprocessing programs. FACILITIES OFTEN LACK the resources required to meet the US Food and Drug Administration's tough quality assurance standards. BY OUTSOURCING, hospitals can reap the benefits of medical device reprocessing without assuming additional staffing and compliance burdens. OUTSOURCING enables hospitals to implement a medical device reprocessing program quickly, with no capital investment and minimal effort.

  1. 78 FR 34669 - Certain Electronic Devices, Including Wireless Communication Devices, Portable Music and Data...

    Science.gov (United States)

    2013-06-10

    ..., Including Wireless Communication Devices, Portable Music and Data Processing Devices, and Tablet Computers... importing wireless communication devices, portable music and data processing devices, and tablet computers... certain electronic devices, including wireless communication devices, portable music and data processing...

  2. Radioactive waste processing device

    International Nuclear Information System (INIS)

    Ikeda, Takashi; Funabashi, Kiyomi; Chino, Koichi.

    1992-01-01

    In a waste processing device for solidifying, pellets formed by condensing radioactive liquid wastes generated from a nuclear power plant, by using a solidification agent, sodium chloride, sodium hydroxide or sodium nitrate is mixed upon solidification. In particular, since sodium sulfate in a resin regenerating liquid wastes absorbs water in the cement upon cement solidification, and increases the volume by expansion, there is a worry of breaking the cement solidification products. This reaction can be prevented by the addition of sodium chloride and the like. Accordingly, integrity of the solidification products can be maintained for a long period of time. (T.M.)

  3. Toroidal nuclear fusion device

    International Nuclear Information System (INIS)

    Ito, Yutaka; Kasahara, Tatsuo; Takizawa, Teruhiro.

    1975-01-01

    Object: To design a device so as to be formed into a large-size and to arrange ports, through which neutral particles enter, in inclined fashion. Structure: Toroidal coils are wound about vacuum vessels which are divided into plural number. In the outer periphery of the vacuum vessels, ports are disposed inclined in the peripheral direction of the vacuum vessels and communicated with the vacuum vessels, and wall surfaces opposed to the ports of the toroidal coils adjacent at least the inclined sides of the ports are inclined substantially simularly to the port wall surfaces. (Kamimura, M.)

  4. Computed tomography device

    International Nuclear Information System (INIS)

    Ohhashi, A.

    1985-01-01

    A computed tomography device comprising a subtraction unit which obtains differential data strings representing the difference between each time-serial projection data string of a group of projection data strings corresponding to a prospective reconstruction image generated by projection data strings acquired by a data acquisition system, a convolution unit which convolves each time-serial projection data string of the group of projection data strings corresponding to the prospective reconstruction image, and a back-projection unit which back-projects the convolved data strings

  5. Radiorespirometic assay device

    International Nuclear Information System (INIS)

    Levin, G.V.; Straat, P.A.

    1981-01-01

    A radiorespirometic assay device is described in which the presence of microorganisms in a sample is determined by placing the sample in contact with a metabolisable radioactive labelled substrate, collecting any gas evolved, exposing a photosensitive material to the gas and determining if a spot is produced on the material. A spot indicates the presence of radioactivity showing that the substrate has been metabolized by a microorganism. Bacteria may be detected in body fluids, hospital operating rooms, water, food, cosmetics and drugs. (U.K.)

  6. Electromechanical motion devices

    CERN Document Server

    Krause, Paul C; Pekarek, Steven D

    2012-01-01

    This text provides a basic treatment of modern electric machine analysis that gives readers the necessary background for comprehending the traditional applications and operating characteristics of electric machines-as well as their emerging applications in modern power systems and electric drives, such as those used in hybrid and electric vehicles. Through the appropriate use of reference frame theory, Electromagnetic Motion Devices, Second Edition introduces readers to field-oriented control of induction machines, constant-torque, and constant-power control of dc, permanent-magnet ac

  7. Microwave heating denitration device

    International Nuclear Information System (INIS)

    Sato, Hajime; Morisue, Tetsuo.

    1984-01-01

    Purpose: To suppress energy consumption due to a reflection of microwaves. Constitution: Microwaves are irradiated to the nitrate solution containing nuclear fuel materials, to cause denitrating reaction under heating and obtain oxides of the nuclear fuel materials. A microwave heating and evaporation can for reserving the nitrate solution is disposed slantwise relative to the horizontal plane and a microwave heating device is connected to the evaporation can, and inert gases for agitation are supplied to the solution within the can. Since the evaporation can is slanted, wasteful energy consumption due to the reflection of the microwaves can be suppressed. (Moriyama, K.)

  8. Microwave warning device

    International Nuclear Information System (INIS)

    Shriner, W.

    1981-01-01

    A device for warning a person carrying or wearing it of the presence of dangerous microwave radiation is fully powered by the radiations being detected. A very low-wattage gas-discharge lamp is energized by a broadly or a sharply tuned receiver circuit including dipole antennas or one antenna and a ''grounding'' casing element. The casing may be largely and uniformly transparent or have different areas gradedly light-transmissive to indicate varying radiation intensities. The casing can be made in the shape of a pocket watch, fountain pen, bracelet or finger ring, etc

  9. Pump safety device

    International Nuclear Information System (INIS)

    Timmermans, Francis; Vandervorst, Jean.

    1981-01-01

    Safety device for longitudinally leak proofing the shaft of a pump in the event of the fracture of the dynamic seal separating the pump fluid high pressure chamber from the low pressure chamber. It is designed for fitting to the primary pumps of nuclear reactors. It includes a hollow cyclindrical piston located coaxially around the pump shaft and normally housed in a chamber provided for this purpose in the fixed housing of the dynamic seal, and means for moving this piston coaxially so as to compress a safety O ring between the shaft and the piston in the event of the dynamic seal failing [fr

  10. WORKSHOP: Low temperature devices

    International Nuclear Information System (INIS)

    Anon.

    1987-01-01

    With extraterrestrial neutrinos (whether from the sun or further afield) continuing to make science news, and with the search for the so far invisible 'dark matter' of the universe a continual preoccupation, physicists from different walks of life (solid state, low temperature, particles, astrophysics) gathered at a workshop on low temperature devices for the detection of neutrinos and dark matter, held from 12-13 March at Ringberg Castle on Lake Tegernsee in the Bavarian Alps, and organized by the Max Planck Institute for Physics and Astrophysics in Munich

  11. Shrinking optical devices

    International Nuclear Information System (INIS)

    Wee, W H; Pendry, J B

    2009-01-01

    Much of optics depends on objects being much larger than the wavelength of light: shadows of opaque objects are sharp only if free of diffraction effects, and 'cat's eye' retroreflectors function only if they are large. Here, we show how to make theoretically arbitrarily small versions of these devices by exploiting the power of a negatively refracting lens to magnify objects that are smaller than the wavelength, thus creating the effect of a large object while keeping all physical dimensions small. We also give a new perspective on the 'perfect lens theorem' on which the paper is based.

  12. WORKSHOP: Low temperature devices

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    1987-06-15

    With extraterrestrial neutrinos (whether from the sun or further afield) continuing to make science news, and with the search for the so far invisible 'dark matter' of the universe a continual preoccupation, physicists from different walks of life (solid state, low temperature, particles, astrophysics) gathered at a workshop on low temperature devices for the detection of neutrinos and dark matter, held from 12-13 March at Ringberg Castle on Lake Tegernsee in the Bavarian Alps, and organized by the Max Planck Institute for Physics and Astrophysics in Munich.

  13. Data mining mobile devices

    CERN Document Server

    Mena, Jesus

    2013-01-01

    With today's consumers spending more time on their mobiles than on their PCs, new methods of empirical stochastic modeling have emerged that can provide marketers with detailed information about the products, content, and services their customers desire.Data Mining Mobile Devices defines the collection of machine-sensed environmental data pertaining to human social behavior. It explains how the integration of data mining and machine learning can enable the modeling of conversation context, proximity sensing, and geospatial location throughout large communities of mobile users

  14. Nanotube resonator devices

    Science.gov (United States)

    Jensen, Kenneth J; Zettl, Alexander K; Weldon, Jeffrey A

    2014-05-06

    A fully-functional radio receiver fabricated from a single nanotube is being disclosed. Simultaneously, a single nanotube can perform the functions of all major components of a radio: antenna, tunable band-pass filter, amplifier, and demodulator. A DC voltage source, as supplied by a battery, can power the radio. Using carrier waves in the commercially relevant 40-400 MHz range and both frequency and amplitude modulation techniques, successful music and voice reception has been demonstrated. Also disclosed are a radio transmitter and a mass sensor using a nanotube resonator device.

  15. CIRSE Vascular Closure Device Registry

    NARCIS (Netherlands)

    Reekers, Jim A.; Müller-Hülsbeck, Stefan; Libicher, Martin; Atar, Eli; Trentmann, Jens; Goffette, Pierre; Borggrefe, Jan; Zeleňák, Kamil; Hooijboer, Pieter; Belli, Anna-Maria

    2011-01-01

    Vascular closure devices are routinely used after many vascular interventional radiology procedures. However, there have been no major multicenter studies to assess the safety and effectiveness of the routine use of closure devices in interventional radiology. The CIRSE registry of closure devices

  16. Smoothing type buffer memory device

    International Nuclear Information System (INIS)

    Podorozhnyj, D.M.; Yashin, I.V.

    1990-01-01

    The layout of the micropower 4-bit smoothing type buffer memory device allowing one to record without counting the sequence of input randomly distributed pulses in multi-channel devices with serial poll, is given. The power spent by a memory cell for one binary digit recording is not greater than 0.15 mW, the device dead time is 10 mus

  17. [Design of SCM inoculation device].

    Science.gov (United States)

    Qian, Mingli; Xie, Haiyuan

    2014-01-01

    The first step of bacilli culture is inoculation bacteria on culture medium. Designing a device to increase efficiency of inoculation is significative. The new device is controlled by SCM. The stepper motor can drive the culture medium rotating, accelerating, decelerating, overturn and suspending. The device is high practicability and efficient, let inoculation easy for operator.

  18. A microfluidic device with pillars

    DEFF Research Database (Denmark)

    2014-01-01

    The invention provides a microfluidic device for mixing liquid reagents, the device comprises, a chip forming at least one reaction chamber between a bottom and a top and extending between an inlet and an outlet. To enable manufacturing from less rigid materials, the device comprises pillars...

  19. Integrated control rod monitoring device

    International Nuclear Information System (INIS)

    Saito, Katsuhiro

    1997-01-01

    The present invention provides a device in which an entire control rod driving time measuring device and a control rod position support device in a reactor building and a central control chamber are integrated systematically to save hardwares such as a signal input/output device and signal cables between boards. Namely, (1) functions of the entire control rod driving time measuring device for monitoring control rods which control the reactor power and a control rod position indication device are integrated into one identical system. Then, the entire devices can be made compact by the integration of the functions. (2) The functions of the entire control rod driving time measuring device and the control rod position indication device are integrated in a central operation board and a board in the site. Then, the place for the installation of them can be used in common in any of the cases. (3) The functions of the entire control rod driving time measuring device and the control rod position indication device are integrated to one identical system to save hardware to be used. Then, signal input/output devices and drift branching panel boards in the site and the central operation board can be saved, and cables for connecting both of the boards is no more necessary. (I.S.)

  20. Radiation effects in optoelectronic devices

    International Nuclear Information System (INIS)

    Barnes, C.E.

    1977-03-01

    A summary is given of studies on radiation effects in light-emitting diodes, laser diodes, detectors, optical isolators and optical fibers. It is shown that the study of radiation damage in these devices can provide valuable information concerning the nature of the devices themselves, as well as methods of hardening these devices for applications in radiation environments

  1. Digital device for synchronous storage

    International Nuclear Information System (INIS)

    Kobzar', Yu.M.; Kovtun, V.G.; Pashechko, N.I.

    1991-01-01

    Synchronous storage digital device for IR electron-photon emission spectrometer operating with analogue-to-digital converter F4223 or monocrystal converter K572PV1 is described. The device accomplished deduction of noise-background in each storage cycle. Summation and deduction operational time equals 90 ns, device output code discharge - 20, number of storages -2 23

  2. Device-Centric Monitoring for Mobile Device Management

    Directory of Open Access Journals (Sweden)

    Luke Chircop

    2016-03-01

    Full Text Available The ubiquity of computing devices has led to an increased need to ensure not only that the applications deployed on them are correct with respect to their specifications, but also that the devices are used in an appropriate manner, especially in situations where the device is provided by a party other than the actual user. Much work which has been done on runtime verification for mobile devices and operating systems is mostly application-centric, resulting in global, device-centric properties (e.g. the user may not send more than 100 messages per day across all applications being difficult or impossible to verify. In this paper we present a device-centric approach to runtime verify the device behaviour against a device policy with the different applications acting as independent components contributing to the overall behaviour of the device. We also present an implementation for Android devices, and evaluate it on a number of device-centric policies, reporting the empirical results obtained.

  3. Humanitarian Use Devices/Humanitarian Device Exemptions in cardiovascular medicine.

    Science.gov (United States)

    Kaplan, Aaron V; Harvey, Elisa D; Kuntz, Richard E; Shiran, Hadas; Robb, John F; Fitzgerald, Peter

    2005-11-01

    The Second Dartmouth Device Development Symposium held in October 2004 brought together leaders from the medical device community, including clinical investigators, senior representatives from the US Food and Drug Administration, large and small device manufacturers, and representatives from the financial community to examine difficult issues confronting device development. The role of the Humanitarian Use Device/Humanitarian Device Exemption (HUD/HDE) pathway in the development of new cardiovascular devices was discussed in this forum. The HUD/HDE pathway was created by Congress to facilitate the availability of medical devices for "orphan" indications, ie, those affecting HDEs have been granted (23 devices, 6 diagnostic tests). As the costs to gain regulatory approval for commonly used devices increase, companies often seek alternative ways to gain market access, including the HUD/HDE pathway. For a given device, there may be multiple legitimate and distinct indications, including indications that meet the HUD criteria. Companies must choose how and when to pursue each of these indications. The consensus of symposium participants was for the HUD/HDE pathway to be reserved for true orphan indications and not be viewed strategically as part of the clinical development plan to access a large market.

  4. Graphene device and method of using graphene device

    Science.gov (United States)

    Bouchiat, Vincent; Girit, Caglar; Kessler, Brian; Zettl, Alexander K.

    2015-08-11

    An embodiment of a graphene device includes a layered structure, first and second electrodes, and a dopant island. The layered structure includes a conductive layer, an insulating layer, and a graphene layer. The electrodes are coupled to the graphene layer. The dopant island is coupled to an exposed surface of the graphene layer between the electrodes. An embodiment of a method of using a graphene device includes providing the graphene device. A voltage is applied to the conductive layer of the graphene device. Another embodiment of a method of using a graphene device includes providing the graphene device without the dopant island. A dopant island is placed on an exposed surface of the graphene layer between the electrodes. A voltage is applied to the conductive layer of the graphene device. A response of the dopant island to the voltage is observed.

  5. Ultrasonic viewing device

    International Nuclear Information System (INIS)

    Ito, Juro.

    1979-01-01

    Purpose: To improve the safety of reactor operation by enabling to detect the states and positions of fuel assemblies over a wide range with a set of ultrasonic viewing device comprising a rotatable ultrasonic transmitter-receiver and a reflector mounted with an adjustable angle. Constitution: A driving portion for a ultrasonic viewing device is provided to a rotary plug closing the opening of a reactor vessel and a guide pipe suspending below the coolant level is provided to the driving portion. An ultrasonic transmitter-receiver is provided at the end of the holder tube in the guide pipe. A reflector is provided at the upper position of the reactor core so as to correspond to the ultrasonic transmitter-receiver. The ultrasonic transmitter-receiver, positioned by the driving portion, performs horizontal movement for scanning the entire surface of the top of the reactor core, as well as vertical movement covering the gap between the upper mechanism on the reactor and the reactor core, whereby the confirmation for the separation of the control rod and the detection for the states of the reactor core can be conducted by the reflection waves from the reflector. (Moriyama, K.)

  6. Movement monitoring device

    International Nuclear Information System (INIS)

    Ichikawa, Takashi; Yoneda, Yasuaki; Hanatsumi, Masaharu.

    1997-01-01

    The present invention provides a device suitable to accurate recognition for the moving state of reactor core fuels as an object to be monitored in a nuclear power plant. Namely, the device of the present invention prepares each of scheduled paths for the movement of the object to be monitored and executed moving paths along with the movement based on the information of the movement obtained from scheduled information for the movement of the reactor core fuels as a object to be monitored and the actual movement of the object to be monitored. The results of the preparation are outputted. As an output mode, (1) the results of preparation for each of the paths for movement and the results of the monitoring obtained by monitoring the state of the object to be monitored are jointed and outputted, (2) images showing each of the paths for the movement are formed, and the formed images are displayed on a screen, and (3) each of the moving paths is prepared as an image, and the image is displayed together with the image of the regions before and after the movement of the object to be monitored. In addition, obtained images of each of the paths for the movement and the monitored images obtained by monitoring the state of the object to be monitored are joined and displayed. (I.S.)

  7. Failed fuel detection device

    International Nuclear Information System (INIS)

    Kawai, Masayoshi; Hayashida, Yoshihisa; Niidome, Jiro.

    1985-01-01

    Purpose: To prevent intrusion of background neutrons to neutron detectors thereby improve the S/N ratio of the detectors in the failed fuel detection device of LMFBR type reactors. Constitution: Neutrons from the reactor core pass through the gaps around the penetration holes in which the primary pipeways pass through the concrete shielding walls and pass through the gaps between the thermal shielding members and the neutron moderating shielding members of the failed fuel detection device and then intrude into the neutron detectors. In view of the above, inner neutron moderating shielding members and movable or resilient neutron shielding members are disposed to the inside of the neutron moderating shielding member. Graphite or carbon hydrides such as paraffin or synthetic resin with a large neutron moderation effect are used as the outer moderating shielding member and materials such as boron or carbon are used for the inner members. As a result, the background neutrons are shielded by the inner neutron moderating shielding members and the resilient neutron shielding members, by which the S/N ratio of the neutron detectors can be increased to 2 - 4 times. (Moriyama, K.)

  8. Reactor core control device

    International Nuclear Information System (INIS)

    Sano, Hiroki

    1998-01-01

    The present invention provides a reactor core control device, in which switching from a manual operation to an automatic operation, and the control for the parameter of an automatic operation device are facilitated. Namely, the hysteresis of the control for the operation parameter by an manual operation input means is stored. The hysteresis of the control for the operation parameter is collected. The state of the reactor core simulated by an operation control to which the collected operation parameters are manually inputted is determined as an input of the reactor core state to the automatic input means. The record of operation upon manual operation is stored as a hysteresis of control for the operation parameter, but the hysteresis information is not only the result of manual operation of the operation parameter. This is results of operation conducted by a skilled operator who judge the state of the reactor core to be optimum. Accordingly, it involves information relevant to the reactor core state. Then, it is considered that the optimum automatic operation is not deviated greatly from the manual operation. (I.S.)

  9. A semiconductor laser device

    Energy Technology Data Exchange (ETDEWEB)

    Takaro, K.; Naoki, T.; Satosi, K.; Yasutosi, K.

    1984-03-17

    A device is proposed which makes it possible to obtain single vertical mode emission in the absence of noise. Noise suppression is achieved by a method which determines the relationship between the donor densities in the second and third layers of an n type semiconductor laser, and the total output optical emission of layers with respect to the emission from the entire laser. The device consists of a photoresist film with a window applied to a 100 GaAs n type conductivity substrate using a standard method. Chemical etching through this window in the substrate is used to generate a slot approximately 1 micrometer in size. After the photoresist film is removed, the following layers are deposited from the liquid phase onto the substrate in the sequence indicated: a telurium doped protective layer of n type AlxGa(1-x) As; 2) an undoped active p type AlyGa(1-6) As layer and a tellurium doped upper protective n type conductivity GaAs layer.

  10. Fuel assembly inspection device

    International Nuclear Information System (INIS)

    Yaginuma, Yoshitaka

    1998-01-01

    The present invention provides a device suitable to inspect appearance of fuel assemblies by photographing the appearance of fuel assemblies. Namely, the inspection device of the present invention measures bowing of fuel assembly or each of fuel rods or both of them based on the partially photographed images of fuel assembly. In this case, there is disposed a means which flashily projects images in the form of horizontal line from a direction intersecting obliquely relative to a horizontal cross section of the fuel assembly. A first image processing means separates the projected image pictures including projected images and calculates bowing. A second image processing means replaces the projected image pictures of the projected images based on projected images just before and after the photographing. Then, images for the measurement of bowing and images for inspection can be obtained simultaneously. As a result, the time required for the photographing can be shortened, the time for inspection can be shortened and an effect of preventing deterioration of photographing means by radiation rays can be provided. (I.S.)

  11. Appearance test device

    International Nuclear Information System (INIS)

    Watanabe, Tadao.

    1995-01-01

    The device of the present invention photographs glass solidification products of high level radioactive wastes by a camera to inspect the state for the surface of the glass solidification products. Namely, illumination light is irradiated to the surface of a material to be tested containing radioactive substances to photograph the surface to be tested and the photographed images are displayed. A photographing unit enhousing an illumination light source and the camera for photographing the surface to be detected is movable in the longitudinal direction of the object to be detected. A first reflector is disposed for reflecting the illumination light from the light source in a horizontal direction intersecting the longitudinal direction described above and reflecting the reflection light from the object to be tested to the camera. A second reflector is disposed to a position opposing to the end face of the object to be detected for entering the illumination light from the first reflector to the end face of the object to be tested and reflecting the reflection light from the end face of the object to be detected to the first reflector. In a device thus composed, the upper and lower end faces of the object to be tested can be illuminated and photographed without facing the photographing unit to the object to be inspected. (I.S.)

  12. Plasma control device

    International Nuclear Information System (INIS)

    Matsutomi, Akiyoshi.

    1995-01-01

    Plasma position and shape estimation values are outputted based on measured values of coil current. When the measured values of the position and the shape are judged to be abnormal, position and shape estimation values estimated by a plasma position and shape estimation means are outputted as position and shape feed back values to a plasma position and shape control means instead of the position and shape measured values. Since only a portion of the abnormal position and shape measured values may also be replaced with the position and shape estimation values, errors in the plasma position and shape feed back values can be reduced as a whole. In addition, even if the position and shape measured values are abnormal or if they can not be measured, plasma control can be continued by alternative position and shape estimation values, thereby enabling to avoid interruption of plasma control. Since the position and shape estimation values are obtained not only with the measured values of coil current but also with the position and shape estimation values, the accuracy is improved. Further, noises superposed on the position and shape measured values are filtered, and the device is stabilized compared with a prior art device. (N.H.)

  13. Next generation toroidal devices

    International Nuclear Information System (INIS)

    Yoshikawa, Shoichi

    1998-10-01

    A general survey of the possible approach for the next generation toroidal devices was made. Either surprisingly or obviously (depending on one's view), the technical constraints along with the scientific considerations lead to a fairly limited set of systems for the most favorable approach for the next generation devices. Specifically if the magnetic field strength of 5 T or above is to be created by superconducting coils, it imposes minimum in the aspect ratio for the tokamak which is slightly higher than contemplated now for ITER design. The similar technical constraints make the minimum linear size of a stellarator large. Scientifically, it is indicated that a tokamak of 1.5 times in the linear dimension should be able to produce economically, especially if a hybrid reactor is allowed. For the next stellarator, it is strongly suggested that some kind of helical axis is necessary both for the (almost) absolute confinement of high energy particles and high stability and equilibrium beta limits. The author still favors a heliac most. Although it may not have been clearly stated in the main text, the stability afforded by the shearless layer may be exploited fully in a stellarator. (author)

  14. Next generation toroidal devices

    Energy Technology Data Exchange (ETDEWEB)

    Yoshikawa, Shoichi [Princeton Plasma Physics Lab., Princeton Univ., NJ (United States)

    1998-10-01

    A general survey of the possible approach for the next generation toroidal devices was made. Either surprisingly or obviously (depending on one`s view), the technical constraints along with the scientific considerations lead to a fairly limited set of systems for the most favorable approach for the next generation devices. Specifically if the magnetic field strength of 5 T or above is to be created by superconducting coils, it imposes minimum in the aspect ratio for the tokamak which is slightly higher than contemplated now for ITER design. The similar technical constraints make the minimum linear size of a stellarator large. Scientifically, it is indicated that a tokamak of 1.5 times in the linear dimension should be able to produce economically, especially if a hybrid reactor is allowed. For the next stellarator, it is strongly suggested that some kind of helical axis is necessary both for the (almost) absolute confinement of high energy particles and high stability and equilibrium beta limits. The author still favors a heliac most. Although it may not have been clearly stated in the main text, the stability afforded by the shearless layer may be exploited fully in a stellarator. (author)

  15. Heat insulation support device

    International Nuclear Information System (INIS)

    Takahashi, Hiroyuki; Koda, Tomokazu; Motojima, Osamu; Yamamoto, Junya.

    1994-01-01

    The device of the present invention comprises a plurality of heat insulation legs disposed in a circumferential direction. Each of the heat insulative support legs has a hollow shape, and comprises an outer column and an inner column as support structures having a heat insulative property (heat insulative structure), and a thermal anchor which absorbs compulsory displacement by a thin flat plate (displacement absorber). The outer column, the thermal anchor and the inner column are connected by a support so as to offset the positional change of objects to be supported due to shrinkage when they are shrunk. In addition, the portion between the superconductive coils as the objects to be supported and the inner column is connected by the support. The superconductive thermonuclear device is entirely contained in a heat insulative vacuum vessel, and the heat insulative support legs are disposed on a lower lid of the heat insulative vacuum vessel. With such a constitution, they are strengthened against lateral load and buckling, thereby enabling to reduce the amount of heat intrusion while keeping the compulsory displacement easy to be absorbed. (I.N.)

  16. Reactor power measuring device

    International Nuclear Information System (INIS)

    Izumi, Mikio; Sano, Yuji; Seki, Eiji; Yoshida, Toshifumi; Ito, Toshiaki.

    1993-01-01

    The present invention provides a self-powered long detector having a sensitivity over the entire length of a reactor core as an entire control rod withdrawal range of a BWR type reactor, and a reactor power measuring device using a gamma ray thermometer which scarcely causes sensitivity degradation. That is, a hollow protection pipe is disposed passing through the reactor core from the outside of a reactor pressure vessel. The self-powered long detectors and the gamma ray thermometers are inserted and installed in the protection pipe. An average reactor power in an axial direction of the reactor relative to a certain position in the horizontal cross section of the reactor core is determined based on the power of the self-powered long detector over the entire length of the reactor core. Since the response of the self-powered detector relative to a local power change is rapid, the output is used as an input signal to a safety protection device of the reactor core. Further, a gamma ray thermometer secured in the reactor and having scarce sensitivity degradation is used instead of an incore travelling neutron monitor used for relative calibration of an existent neutron monitor secured in the reactor. (I.S.)

  17. Fast reactor recharging device

    International Nuclear Information System (INIS)

    Artemiev, L.N.; Kurilkin, V.V.

    1979-01-01

    Disclosure is made of a device for recharging a fast-neutron reactor, intended for the transfer of fuel assemblies and rods of the control and safety system, having profiled heads to be gripped on the outside. The device comprises storage drums whose compartments for rods of the control and safety system are identical to compartments for fuel assemblies. In order to store and transport rods of the control and safety system from the storage drums to the recharging mechanism provision is made for sleeve-type holders. When placed in such a holder, the dimensions of a rod of the control and safety system are equal to those of a fuel assembly. To join a holder to a rod of the control and safety system, on the open end of each holder there is mounted a collet, whereas on the surface of each rod of the control and safety system, close to its head, there is provided an encircling groove to interact with the collet. The grip of the recharging mechanism is provided with a stop interacting with the collet in order to open the latter and withdraw the safety and control system rod from its holder

  18. Optical analog transmission device

    International Nuclear Information System (INIS)

    Ikawa, Shinji.

    1994-01-01

    The present invention concerns a device such as electro-optical conversion elements, optoelectric-electric elements and optical transmission channel, not undergoing deleterious effects on the efficiency of conversion and transmission due to temperature, and aging change. That is, a sine wave superposing means superposes, on a detector signal to be transmitted, a sine-wave signal having a predetermined amplitude and at a frequency lower than that of the detector signal. An optoelectric conversion means converts the electric signal as the signal of the sine-wave signal superposing means into an optical signal and outputs the same to an optical transmitting channel. The optoelectric conversion means converts the transmitted signal to an electric signal. A discriminating means discriminates the electric signal into a detector signal and a sine-wave signal. A calculating means calculates an optical transmitting efficiency of the transmitting channel based on the amplitude of the discriminated sine-wave signal. A processing means compensates an amplitude value of the detector signals discriminated by the discriminating means based on the optical transmission efficiency. As a result, an optical analog transmission device can be attained, which conducts optical transmission at a high accuracy without undergoing the defective effects of the optical transmission efficiency. (I.S.)

  19. Micro-Organ Device

    Science.gov (United States)

    Gonda, Steve R. (Inventor); Chang, Robert C. (Inventor); Starly, Binil (Inventor); Culbertson, Christopher (Inventor); Holtorf, Heidi L. (Inventor); Sun, Wei (Inventor); Leslie, Julia (Inventor)

    2013-01-01

    A method for fabricating a micro-organ device comprises providing a microscale support having one or more microfluidic channels and one or more micro-chambers for housing a micro-organ and printing a micro-organ on the microscale support using a cell suspension in a syringe controlled by a computer-aided tissue engineering system, wherein the cell suspension comprises cells suspended in a solution containing a material that functions as a three-dimensional scaffold. The printing is performed with the computer-aided tissue engineering system according to a particular pattern. The micro-organ device comprises at least one micro-chamber each housing a micro-organ; and at least one microfluidic channel connected to the micro-chamber, wherein the micro-organ comprises cells arranged in a configuration that includes microscale spacing between portions of the cells to facilitate diffusion exchange between the cells and a medium supplied from the at least one microfluidic channel.

  20. Carbon for sensing devices

    CERN Document Server

    Tagliaferro, Alberto

    2015-01-01

    This book reveals why carbon is playing such an increasingly prominent role as a sensing material. The various steps that transform a raw material in a sensing device are thoroughly presented and critically discussed.  The authors deal with all aspects of carbon-based sensors, starting from the various hybridization and allotropes of carbon, with specific focus on micro and nanosized carbons (e.g., carbon nanotubes, graphene) and their growth processes. The discussion then moves to the role of functionalization and the different routes to achieve it. Finally, a number of sensing applications in various fields are presented, highlighting the connection with the basic properties of the various carbon allotropes.  Readers will benefit from this book’s bottom-up approach, which starts from the local bonding in carbon solids and ends with sensing applications, linking the local hybridization of carbon atoms and its modification by functionalization to specific device performance. This book is a must-have in th...

  1. Reactor protecting device

    International Nuclear Information System (INIS)

    Ono, Hiroshi; Kasuga, Hajime; Kasuga, Hiroshi.

    1984-01-01

    Purpose: To reduce the recycling flowrate thereby decrease the neutron flux level before the reactor shutdown upon generation of abnormality such as increase in the neutron flux, by setting the safety level lower than the value for generating the reaction scram signal. Constitution: A netron flux safety level setter and an instruction signal generator are disposed between a neutron flux detector and a recycling flowrate control device. A neutron flux safety level lower than the level for generating a reactor scram signal and higher that the level for the ordinary operation is set and, if the detection level for the neutron flux in the reactor core arrives at the safety level, a neutron flux decreasing instruction signal is outputted from the instruction signal generator to the recycling flowrate control device to thereby decrease the recycling flowrate and decrease the neutron flux without reaching the reactor shutdown, whereby the thermal safety of the fuel rod can be maintained and the reactor operation performance can be improved. (Moriyama, K.)

  2. Radiation monitoring device

    International Nuclear Information System (INIS)

    Sato, Toshifumi.

    1993-01-01

    The device of the present invention concerns a reactor start-up region monitor of a nuclear power plant. In an existent start-up region monitor, bias voltage is limited, if the reactor moves to a power region, in order to prevent degradation of radiation detectors. Accordingly, since the power is lower than an actual reactor power, the reactor power can not be monitored. The device of the present invention comprises a memory means for previously storing a Plateau's characteristic of the radiation detectors and a correction processing means for obtaining a correction coefficient in accordance with the Plateau's characteristic to correct and calculate the reactor power when the bias voltage is limited. With such a constitution, when the reactor power exceeds a predetermined value and the bias voltage is limited, the correction coefficient can be obtained by the memory means and the correction processing means. Corrected reactor power can also be obtained from the start-up region monitor by the correction coefficient. As a result, monitoring of the reactor power can be continued while preventing degradation of the radiation detector even if the bias voltage is limited. (I.S.)

  3. Carbon based prosthetic devices

    Energy Technology Data Exchange (ETDEWEB)

    Devlin, D.J.; Carroll, D.W.; Barbero, R.S.; Archuleta, T. [Los Alamos National Lab., NM (US); Klawitter, J.J.; Ogilvie, W.; Strzepa, P. [Ascension Orthopedics (US); Cook, S.D. [Tulane Univ., New Orleans, LA (US). School of Medicine

    1998-12-31

    This is the final report of a one-year, Laboratory Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). The project objective was to evaluate the use of carbon/carbon-fiber-reinforced composites for use in endoprosthetic devices. The application of these materials for the metacarpophalangeal (MP) joints of the hand was investigated. Issues concerning mechanical properties, bone fixation, biocompatibility, and wear are discussed. A system consisting of fiber reinforced materials with a pyrolytic carbon matrix and diamond-like, carbon-coated wear surfaces was developed. Processes were developed for the chemical vapor infiltration (CVI) of pyrolytic carbon into porous fiber preforms with the ability to tailor the outer porosity of the device to provide a surface for bone in-growth. A method for coating diamond-like carbon (DLC) on the articulating surface by plasma-assisted chemical vapor deposition (CVD) was developed. Preliminary results on mechanical properties of the composite system are discussed and initial biocompatibility studies were performed.

  4. Operation planning device

    International Nuclear Information System (INIS)

    Watanabe, Takashi; Odakawa, Naoto; Erikuchi, Makoto; Okada, Masayuki; Koizumi, Atsuhiko.

    1996-01-01

    The device of the present invention provides a device suitable for monitoring a reactor core state and operation replanning in terms of reactor operation. Namely, (1) an operation result difference judging means judges that replanning is necessary when the operation results deviates from the operation planning, (2) an operation replanning rule data base storing means stores a deviation key which shows various kinds of states where the results deviate from the planning and a rule for replanning for returning to the operation planning on every deviating key, (3) an operation replanning means forms a new operation planning in accordance with the rule which is retrieved based on the deviation key, (4) an operation planning optimizing rule data base storing means evaluates the reformed planning and stores it on every evaluation item, (5) an operation planning optimization means correct the operation planning data so as to be optimized when the evaluation of the means (4) is less than a reference value, and (6) an operation planning display means edits adaptable operation planning data and the result of the evaluation and displays them. (I.S.)

  5. Plant state display device

    International Nuclear Information System (INIS)

    Kadota, Kazuo; Ito, Toshiichiro.

    1994-01-01

    The device of the present invention conducts information processing suitable for a man to solve a problem in a plant such as a nuclear power plant incorporating a great amount of information, where safety is required and provides information to an operator. Namely, theories and rules with respect to the flow and balanced state of materials and energy upon plant start-up, and a vapor cycle of operation fluids are symbolized and displayed on the display screen of the device. Then, the display of the plant information suitable to the information processing for a man to dissolve problems is provided. Accordingly, a mechanism for analyzing a purpose of the plant is made more definite, thereby enabling to prevent an erroneous judgement of an operator and occurrence of plant troubles. In addition, a simular effect can also be expected when the theories and rules with respect to the flow and the balanced state of materials and energy and thermohydrodynamic behavior of the operation fluids in a state of after-heat removing operation during shutdown of the plant are symbolized and displayed. (I.S.)

  6. Uranium-scintillator device

    International Nuclear Information System (INIS)

    Smith, S.D.

    1979-01-01

    The calorimeter subgroup of the 1977 ISABELLE Summer Workshop strongly recommended investigation of the uranium-scintillator device because of its several attractive features: (1) increased resolution for hadronic energy, (2) fast time response, (3) high density (i.e., 16 cm of calorimeter per interaction length), and, in comparison with uranium--liquid argon detectors, (4) ease of construction, (5) simple electronics, and (6) lower cost. The AFM group at the CERN ISR became interested in such a calorimeter for substantially the same reasons, and in the fall of 1977 carried out tests on a uranium-scintillator (U-Sc) calorimeter with the same uranium plates used in their 1974 studies of the uranium--liquid argon (U-LA) calorimeter. The chief disadvantage of the scintillator test was that the uranium plates were too small to fully contain the hadronic showers. However, since the scintillator and liquid argon tests were made with the plates, direct comparison of the two types of devices could be made

  7. Reactor feedwater control device

    International Nuclear Information System (INIS)

    Koshi, Yuji.

    1993-01-01

    In the device of the present invention, an excess response is not caused in a reactor feed water system even when voids are fluctuated by using an actual water level signal as a reactor water level signal. That is, a standard water level signal and a reactor water level signal are inputted to a comparator. An adder adds water level difference signal outputted from the comparator and mismatch flow rate signal prepared by multiplying the difference between a main steam flow rate signal and a feed water flow rate signal by a mismatch gain. A feed water controller integrates the added signal and outputs flow rate demand signal. A feed water system receives the flow rate demand signal as input. A water level calculation means is disposed to such a device for calculating an actual water level based on the change of coolant possessing amount of the reactor, and the output thereof is defined as a reactor water level signal. With such procedures, excessive elevation of water level of the reactor can be prevented even upon occurrence of void fluctuation phenomenon or the like in the reactor such as upon sole scram operation. Accordingly, plant shut down caused thereby can be avoided safely. (I.S.)

  8. Reactor safety device

    International Nuclear Information System (INIS)

    Okada, Yasumasa.

    1987-01-01

    Purpose: To scram control rods by processing signals from a plurality of temperature detectors and generating abnormal temperature warning upon occurrence of abnormal temperature in a nuclear reactor. Constitution: A temperature sensor comprising a plurality of reactors each having a magnetic body as the magnetic core having a curie point different from each other and corresponding to the abnormal temperature against which reactor core fuels have to be protected is disposed in an identical instrumentation well near the reactor core fuel outlet/inlet of a reactor. A temperature detection device actuated upon detection of an abnormal temperature by the abrupt reduction of the reactance of each of the reactors is disposed. An OR circuit and an AND circuit for conducting OR and AND operations for each of the abnormal temperature detection signals from the temperature detection device are disposed. The output from the OR circuit is used as the abnormal temperature warning signal, while the output from the AND circuit is utilized as a signal for actuating the scram operation of control rod drive mechanisms. Accordingly, it is possible to improve the reliability of the reactor scram system, particularly, improve the reliability under a high temperature atmosphere. (Kamimura, M.)

  9. Deformable paper origami optoelectronic devices

    KAUST Repository

    He, Jr-Hau

    2017-01-19

    Deformable optoelectronic devices are provided, including photodetectors, photodiodes, and photovoltaic cells. The devices can be made on a variety of paper substrates, and can include a plurality of fold segments in the paper substrate creating a deformable pattern. Thin electrode layers and semiconductor nanowire layers can be attached to the substrate, creating the optoelectronic device. The devices can be highly deformable, e.g. capable of undergoing strains of 500% or more, bending angles of 25° or more, and/or twist angles of 270° or more. Methods of making the deformable optoelectronic devices and methods of using, e.g. as a photodetector, are also provided.

  10. Plasma devices for hydrocarbon reformation

    KAUST Repository

    Cha, Min Suk

    2017-02-16

    Plasma devices for hydrocarbon reformation are provided. Methods of using the devices for hydrocarbon reformation are also provided. The devices can include a liquid container to receive a hydrocarbon source, and a plasma torch configured to be submerged in the liquid. The plasma plume from the plasma torch can cause reformation of the hydrocarbon. The device can use a variety of plasma torches that can be arranged in a variety of positions in the liquid container. The devices can be used for the reformation of gaseous hydrocarbons and/or liquid hydrocarbons. The reformation can produce methane, lower hydrocarbons, higher hydrocarbons, hydrogen gas, water, carbon dioxide, carbon monoxide, or a combination thereof.

  11. Cybersecurity for Connected Diabetes Devices.

    Science.gov (United States)

    Klonoff, David C

    2015-04-16

    Diabetes devices are increasingly connected wirelessly to each other and to data-displaying reader devices. Threats to the accurate flow of information and commands may compromise the function of these devices and put their users at risk of health complications. Sound cybersecurity of connected diabetes devices is necessary to maintain confidentiality, integrity, and availability of the data and commands. Diabetes devices can be hacked by unauthorized agents and also by patients themselves to extract data that are not automatically provided by product software. Unauthorized access to connected diabetes devices has been simulated and could happen in reality. A cybersecurity standard designed specifically for connected diabetes devices will improve the safety of these products and increase confidence of users that the products will be secure. © 2015 Diabetes Technology Society.

  12. Human Factors and Medical Devices

    International Nuclear Information System (INIS)

    Dick Sawyer

    1998-01-01

    Medical device hardware- and software-driven user interfaces should be designed to minimize the likelihood of use-related errors and their consequences. The role of design-induced errors in medical device incidents is attracting widespread attention. The U.S. Food and Drug Administration (FDA) is fully cognizant that human factors engineering is critical to the design of safe medical devices, and user interface design is receiving substantial attention by the agency. Companies are paying more attention to the impact of device design, including user instructions, upon the performance of those health professionals and lay users who operate medical devices. Concurrently, the FDA is monitoring human factors issues in its site inspections, premarket device approvals, and postmarket incident evaluations. Overall, the outlook for improved designs and safer device operation is bright

  13. Firewood preparation devices in 1994

    International Nuclear Information System (INIS)

    Mutikainen, A.

    1994-01-01

    A review of the market situation regarding firewood preparation devices is presented. The information was collected from the answers to a mail questionnaire. The review is assumed to include all the leading manufacturers and importers. Firewood production devices were available from 26 manufacturers. The range of models amounted to over 70. These may be divided into three categories: 1. cutting devices: the most common solution being a cross-cutting circular saw. There were only a few of these on sale as it is quite easy to include a splitting device on the same frame. 2. Splitting devices: e.g. screw splitter and hydraulically powered splitter. About 20 models are available on the markets. Cross cutting and splitting devices: these are the most popular devices. A cross-cutting circular saw with screw or hydraulic splitter is the most common type. There are about 50 models available on the markets. Cross-cutting and splitting devices are often equipped with conveyor for transferring the split wood e.g. into a trailer. Chopping devices are delivered as tractor powered devices, as electric motor powered devices or as combustion engine powered devices. Some of them are equipped with a time saving feeding device enabling the next stem to be lifted into position while the previous one is being chopped. The Finnish Work Efficiency Institute's studies show that when cross-cutting and splitting of stems into pieces of 35-50 cm in length, productivity for one operator varies in between 0.8 - 3.2 m 3 /h, depending on the device and work method used. (6 refs., 1 fig., 2 tabs.)

  14. Torus type thermonuclear device

    International Nuclear Information System (INIS)

    Imura, Yasuya.

    1979-01-01

    Purpose: To attain supporting effect against electromagnetic force and moderate the inner stress applied to toroidal coils due to thermal expansion by intervening a stress relaxation member between the outer circumferential side of a torus and a support device in toroidal coils. Constitution: Toroidal coils for confining a plasma within a torus vacuum container is supported on a support secured to upper and lower bases. A thermoplastic stress relaxation material of a low young's modulus is put between the outer circumferential side of the torus container and the torus outer circumferential side of the support in the toroidal coil. Thermoplastic resin is best suited to the stress relaxation substance, although tetrafluoro resin may be used as the stress relaxation substance while packing non-woven tetron fabric or non-woven glass fabric impregnated with varnish in a gap between the stress relaxation substance and the support or the toroidal coils. (Seki, T.)

  15. Reactor power control device

    International Nuclear Information System (INIS)

    Doi, Kazuyori.

    1981-01-01

    Purpose: To automatically control the BWR type reactor power by simple and short-time searching the load pattern nearest to the required pattern at a nuclear power plant side. Constitution: The reactor power is automatically regulated by periodical modifying of coefficients fitting to a reactor core model, according as a required load pattern. When a load requirement pattern is given, a simulator estimates the total power change and the axial power distribution change from a xenon density change output calculated by a xenon dynamic characteristic estimating device, and a load pattern capable of being realized is searched. The amount to be recirculated is controlled on the basis of the load patteren thus searched, and the operation of the BWR type reactor is automatically controlled at the side of the nuclear power plant. (Kamimura, M.)

  16. Reactor power monitoring device

    International Nuclear Information System (INIS)

    Kono, Shigehiro.

    1990-01-01

    Among a plurality of power monitoring programs in a reactor power monitoring device, rapid response is required for a scram judging program for the power judging processing of scram signals. Therefore, the scram judging program is stored independently from other power monitoring programs, applied with a priority order, and executed in parallel with other programs, to output scram signals when the detected data exceeds a predetermined value. As a result, the capacity required for the scram judging program is reduced and the processing can be conducted in a short period of time. In addition, since high priority is applied to the scram judging program which is divided into a small capacity, it is executed at higher frequency than other programs when they are executed in parallel. That is, since the entire processings for the power monitoring program are repeated in a short cycle, the response speed of the scram signals required for high responsivity can be increased. (N.H.)

  17. Monitor inspection device

    International Nuclear Information System (INIS)

    Ueshima, Yoshinobu.

    1995-01-01

    The device of the present invention reliably conducts monitoring by radiation monitors in a nuclear power plant thereby contributing to save the number of radiation operators and reduction of radiation exposure. Namely, radiation monitors continuously measure a plurality of γ-ray levels. A branched simultaneously counting circuit receives these signals. The output of the branched simultaneously counting circuit is inputted to a differentiation means. The differentiation means calculates a variation coefficient for each of the radiation monitoring values, namely, equivalent dose rates, and records and monitors change with time of the equivalent dose rates. With such procedures, the results of the monitoring of γ-ray levels can be judged objectively corresponding to the increase of the equivalent dose rates. As a result, the number of radiation operators can be saves and radiation exposure of the radiation operators can be reduced. (I.S.)

  18. Fission products collecting devices

    International Nuclear Information System (INIS)

    Matsumoto, Hiroshi

    1979-01-01

    Purpose: To enable fission products trap with no contamination to coolants and cover gas by the provision of a fission products trap above the upper part of a nuclear power plant. Constitution: Upon fuel failures in a reactor core, nuclear fission products leak into coolants and move along the flow of the coolants to the coolants above the reactor core. The fission products are collected in a trap container and guided along a pipeline into fission products detector. The fission products detector monitors the concentration of the fission products and opens the downstream valve of the detector when a predetermined concentration of the fission products is detected to introduce the fission products into a waste gas processing device and release them through the exhaust pipe. (Seki, T.)

  19. Personal annunciation device

    Science.gov (United States)

    Angelo, Peter [Oak Ridge, TN; Younkin, James [Oak Ridge, TN; DeMint, Paul [Kingston, TN

    2011-01-25

    A personal annunciation device (PAD) providing, in an area of interest, compensatory annunciation of the presence of an abnormal condition in a hazardous area and accountability of the user of the PAD. Compensatory annunciation supplements primary annunciation provided by an emergency notification system (ENS). A detection system detects an abnormal condition, and a wireless transmission system transmits a wireless transmission to the PAD. The PAD has a housing enclosing the components of the PAD including a communication module for receiving the wireless transmission, a power supply, processor, memory, annunciation system, and RFID module. The RFID module has an RFID receiver that listens for an RFID transmission from an RFID reader disposed in a portal of an area of interest. The PAD identifies the transmission and changes its operating state based on the transmission. The RFID readers recognize, record, and transmit the state of the PAD to a base station providing accountability of the wearer.

  20. Temperature measurement device

    International Nuclear Information System (INIS)

    Fournier, Christian; Lions, Noel.

    1975-01-01

    The present invention relates to a temperature measuring system that can be applied in particular to monitoring the temperature of the cooling liquid metal of the outlet of the core assemblies of a fast reactor. Said device combines a long hollow metallic pole, at least partially dipped into the liquid metal and constituting a first thermocouple junction between said pole, and two metallic conductors of different nature, joined at one of their ends to constitute the second thermocouple junction. Said conductors suitably insulated are arranged inside a sheath. Said sheath made of the same metals as the pole extends inside the latter and is connected with the pole through a soldered joint. Said reliable system permits an instantaneous measurement of a quantity representing the variations in the recorded temperature and a measurement of the mean surrounding temperature that can be direcly used as a reference for calibrating the first one [fr