WorldWideScience

Sample records for conversion light water

  1. Photoelectrochemical water splitting on nanoporous GaN thin films for energy conversion under visible light

    Science.gov (United States)

    Cao, Dezhong; Xiao, Hongdi; Fang, Jiacheng; Liu, Jianqiang; Gao, Qingxue; Liu, Xiangdong; Ma, Jin

    2017-01-01

    Nanoporous (NP) GaN thin films, which were fabricated by an electrochemical etching method at different voltages, were used as photoelectrodes during photoelectrochemical (PEC) water splitting in 1 M oxalic acid solution. Upon illumination at a power density of 100 mW cm‑2 (AM 1.5), water splitting is observed in NP GaN thin films, presumably resulting from the valence band edge which is more positive than the redox potential of the oxidizing species. In comparison with NP GaN film fabricated at 8 V, NP GaN obtained at 18 V shows nearly twofold enhancement in photocurrent with the maximum photo-to-hydrogen conversion efficiency of 1.05% at ~0 V (versus Ag/AgCl). This enhancement could be explained with (i) the increase of surface area and surface states, and (ii) the decrease of resistances and carrier concentration in the NP GaN thin films. High stability of the NP GaN thin films during the PEC water splitting further confirms that the NP GaN thin film could be applied to the design of efficient solar cells and solar fuel devices.

  2. Frequency conversion of structured light.

    Science.gov (United States)

    Steinlechner, Fabian; Hermosa, Nathaniel; Pruneri, Valerio; Torres, Juan P

    2016-02-15

    Coherent frequency conversion of structured light, i.e. the ability to manipulate the carrier frequency of a wave front without distorting its spatial phase and intensity profile, provides the opportunity for numerous novel applications in photonic technology and fundamental science. In particular, frequency conversion of spatial modes carrying orbital angular momentum can be exploited in sub-wavelength resolution nano-optics and coherent imaging at a wavelength different from that used to illuminate an object. Moreover, coherent frequency conversion will be crucial for interfacing information stored in the high-dimensional spatial structure of single and entangled photons with various constituents of quantum networks. In this work, we demonstrate frequency conversion of structured light from the near infrared (803 nm) to the visible (527 nm). The conversion scheme is based on sum-frequency generation in a periodically poled lithium niobate crystal pumped with a 1540-nm Gaussian beam. We observe frequency-converted fields that exhibit a high degree of similarity with the input field and verify the coherence of the frequency-conversion process via mode projection measurements with a phase mask and a single-mode fiber. Our results demonstrate the suitability of exploiting the technique for applications in quantum information processing and coherent imaging.

  3. Frequency conversion of structured light

    CERN Document Server

    Steinlechner, Fabian; Pruneri, Valerio; Torres, Juan P

    2015-01-01

    We demonstrate the coherent frequency conversion of structured light, optical beams in which the phase varies in each point of the transverse plane, from the near infrared (803nm) to the visible (527nm). The frequency conversion process makes use of sum-frequency generation in a periodically poled lithium niobate (ppLN) crystal with the help of a 1540-nm Gaussian pump beam. We perform far-field intensity measurements of the frequency-converted field, and verify the sought-after transformation of the characteristic intensity and phase profiles for various input modes. The coherence of the frequency-conversion process is confirmed using a mode-projection technique with a phase mask and a single-mode fiber. The presented results could be of great relevance to novel applications in high-resolution microscopy and quantum information processing.

  4. Catalytic conversion of light alkanes

    Energy Technology Data Exchange (ETDEWEB)

    Lyons, J.E.

    1992-06-30

    The second Quarterly Report of 1992 on the Catalytic Conversion of Light Alkanes reviews the work done between April 1, 1992 and June 31, 1992 on the Cooperative Agreement. The mission of this work is to devise a new catalyst which can be used in a simple economic process to convert the light alkanes in natural gas to oxygenate products that can either be used as clean-burning, high octane liquid fuels, as fuel components or as precursors to liquid hydrocarbon uwspomdon fuel. During the past quarter we have continued to design, prepare, characterize and test novel catalysts for the mild selective reaction of light hydrocarbons with air or oxygen to produce alcohols directly. These catalysts are designed to form active metal oxo (MO) species and to be uniquely active for the homolytic cleavage of the carbon-hydrogen bonds in light alkanes producing intermediates which can form alcohols. We continue to investigate three molecular environments for the active catalytic species that we are trying to generate: electron-deficient macrocycles (PHASE I), polyoxometallates (PHASE II), and regular oxidic lattices including zeolites and related structures as well as other molecular surface structures having metal oxo groups (PHASE I).

  5. Impact of wastewater infrastructure upgrades on the urban water cycle: Reduction in halogenated reaction byproducts following conversion from chlorine gas to ultraviolet light disinfection

    Energy Technology Data Exchange (ETDEWEB)

    Barber, Larry B. [U.S. Geological Survey, 3215 Marine St., Boulder, CO 80303 (United States); Hladik, Michelle L. [U.S. Geological Survey, 6000 J Street Placer Hall, Sacramento, CA 95819 (United States); Vajda, Alan M. [University of Colorado, Department of Integrative Biology, CB 171, Denver, CO 80217 (United States); Fitzgerald, Kevin C. [U.S. Geological Survey, 3215 Marine St., Boulder, CO 80303 (United States); AECOM, 500 West Jefferson St., Ste. 1600, Louisville, KY 40202 (United States); Douville, Chris [City of Boulder, 4049 75th Street, Boulder, CO 80301 (United States)

    2015-10-01

    The municipal wastewater treatment facility (WWTF) infrastructure of the United States is being upgraded to expand capacity and improve treatment, which provides opportunities to assess the impact of full-scale operational changes on water quality. Many WWTFs disinfect their effluent prior to discharge using chlorine gas, which reacts with natural and synthetic organic matter to form halogenated disinfection byproducts (HDBPs). Because HDBPs are ubiquitous in chlorine-disinfected drinking water and have adverse human health implications, their concentrations are regulated in potable water supplies. Less is known about the formation and occurrence of HDBPs in disinfected WWTF effluents that are discharged to surface waters and become part of the de facto wastewater reuse cycle. This study investigated HDBPs in the urban water cycle from the stream source of the chlorinated municipal tap water that comprises the WWTF inflow, to the final WWTF effluent disinfection process before discharge back to the stream. The impact of conversion from chlorine-gas to low-pressure ultraviolet light (UV) disinfection at a full-scale (68,000 m{sup 3} d{sup −1} design flow) WWTF on HDBP concentrations in the final effluent was assessed, as was transport and attenuation in the receiving stream. Nutrients and trace elements (boron, copper, and uranium) were used to characterize the different urban source waters, and indicated that the pre-upgrade and post-upgrade water chemistry was similar and insensitive to the disinfection process. Chlorinated tap water during the pre-upgrade and post-upgrade samplings contained 11 (mean total concentration = 2.7 μg L{sup −1}; n = 5) and 10 HDBPs (mean total concentration = 4.5 μg L{sup −1}), respectively. Under chlorine-gas disinfection conditions 13 HDBPs (mean total concentration = 1.4 μg L{sup −1}) were detected in the WWTF effluent, whereas under UV disinfection conditions, only one HDBP was detected. The chlorinated WWTF effluent had

  6. Light & Water

    Directory of Open Access Journals (Sweden)

    Óscar Natividad Puig

    2013-06-01

    Full Text Available The proposal explores the Caos Theories, specifically, how applicable they are on local architectural interventions. It compiles a short study about possible variations of a same piece, in order to create difeerent ruled surfaces. Those pieces are distributed around a fractal attractor. The cores of these attractors are the ones responsible of collecting all the water flowing through the system. Once built, the project will enclose an open but covered space. Within this space, many different activities can be embraced, which allows its adaptability to each community where it?s placed. An open market will be the most common use though. It will allow selling agricultural products developed among the same community. Products irrigated with the extra water source collected by the cores of the fractal attractors.

  7. Impact of wastewater infrastructure upgrades on the urban water cycle: Reduction in halogenated reaction byproducts following conversion from chlorine gas to ultraviolet light disinfection.

    Science.gov (United States)

    Barber, Larry B; Hladik, Michelle L; Vajda, Alan M; Fitzgerald, Kevin C; Douville, Chris

    2015-10-01

    The municipal wastewater treatment facility (WWTF) infrastructure of the United States is being upgraded to expand capacity and improve treatment, which provides opportunities to assess the impact of full-scale operational changes on water quality. Many WWTFs disinfect their effluent prior to discharge using chlorine gas, which reacts with natural and synthetic organic matter to form halogenated disinfection byproducts (HDBPs). Because HDBPs are ubiquitous in chlorine-disinfected drinking water and have adverse human health implications, their concentrations are regulated in potable water supplies. Less is known about the formation and occurrence of HDBPs in disinfected WWTF effluents that are discharged to surface waters and become part of the de facto wastewater reuse cycle. This study investigated HDBPs in the urban water cycle from the stream source of the chlorinated municipal tap water that comprises the WWTF inflow, to the final WWTF effluent disinfection process before discharge back to the stream. The impact of conversion from chlorine-gas to low-pressure ultraviolet light (UV) disinfection at a full-scale (68,000 m(3) d(-1) design flow) WWTF on HDBP concentrations in the final effluent was assessed, as was transport and attenuation in the receiving stream. Nutrients and trace elements (boron, copper, and uranium) were used to characterize the different urban source waters, and indicated that the pre-upgrade and post-upgrade water chemistry was similar and insensitive to the disinfection process. Chlorinated tap water during the pre-upgrade and post-upgrade samplings contained 11 (mean total concentration=2.7 μg L(-1); n=5) and 10 HDBPs (mean total concentration=4.5 μg L(-1)), respectively. Under chlorine-gas disinfection conditions 13 HDBPs (mean total concentration=1.4 μg L(-1)) were detected in the WWTF effluent, whereas under UV disinfection conditions, only one HDBP was detected. The chlorinated WWTF effluent had greater relative proportions of

  8. Impact of wastewater infrastructure upgrades on the urban water cycle: Reduction in halogenated reaction byproducts following conversion from chlorine gas to ultraviolet light disinfection

    Science.gov (United States)

    Barber, Larry B.; Hladik, Michelle; Vajda, Alan M.; Fitzgerald, Kevin C.; Douville, Chris

    2015-01-01

    The municipal wastewater treatment facility (WWTF) infrastructure of the United States is being upgraded to expand capacity and improve treatment, which provides opportunities to assess the impact of full-scale operational changes on water quality. Many WWTFs disinfect their effluent prior to discharge using chlorine gas, which reacts with natural and synthetic organic matter to form halogenated disinfection byproducts (HDBPs). Because HDBPs are ubiquitous in chlorine-disinfected drinking water and have adverse human health implications, their concentrations are regulated in potable water supplies. Less is known about the formation and occurrence of HDBPs in disinfected WWTF effluents that are discharged to surface waters and become part of the de facto wastewater reuse cycle. This study investigated HDBPs in the urban water cycle from the stream source of the chlorinated municipal tap water that comprises the WWTF inflow, to the final WWTF effluent disinfection process before discharge back to the stream. The impact of conversion from chlorine-gas to low-pressure ultraviolet light (UV) disinfection at a full-scale (68,000 m3 d−1 design flow) WWTF on HDBP concentrations in the final effluent was assessed, as was transport and attenuation in the receiving stream. Nutrients and trace elements (boron, copper, and uranium) were used to characterize the different urban source waters, and indicated that the pre-upgrade and post-upgrade water chemistry was similar and insensitive to the disinfection process. Chlorinated tap water during the pre-upgrade and post-upgrade samplings contained 11 (mean total concentration = 2.7 μg L−1; n=5) and 10 HDBPs (mean total concentration = 4.5 μg L−1), respectively. Under chlorine-gas disinfection conditions 13 HDBPs (mean total concentration = 1.4 μg L−1) were detected in the WWTF effluent, whereas under UV disinfection conditions, only one HDBP was detected. The chlorinated WWTF effluent had greater relative

  9. A Novel Conversion of Ti-Bearing Blast-Furnace Slag into Water Splitting Photocatalyst with Visible-Light-Response

    Science.gov (United States)

    Lü, Huihong; Li, Ning; Wu, Xingrong; Li, Liaosha; Gao, Zhifang; Shen, Xingmei

    2013-12-01

    A novel visible-light-response photocatalyst was prepared through the heat treatment of Ti-bearing blast-furnace slag with sodium nitrate and subsequently leaching processes in which most of the SiO2, Al2O3, and MgO in Ti-slag (TS) have been separated. The photocatalytic activity of the TTS was studied by observing the evolution of H2 under the UV-Vis and visible light. Compared with the TS and commercial perovskite CaTiO3, the sample prepared exhibited an exclusive visible-light-response activity and enhanced H2 evolution.

  10. Light harvesting for quantum solar energy conversion

    Science.gov (United States)

    Markvart, Tomas

    2000-05-01

    Despite wide structural and functional differences, the laws that govern quantum solar energy conversion to chemical energy or electricity share many similarities. In the photosynthetic membrane, in common with semiconductor solar cells, the conversion process proceeds from the creation of electron-hole pairs by a photon of light, followed by charge separation to produce the required high-energy product. In many cases, however, mechanisms are needed to enhance the optical absorption cross-section and extend the spectral range of operation. A common way of achieving this is by light harvesting: light absorption by a specialised unit which transfers the energy to the conversion apparatus. This paper considers two examples of light harvesting - semiconductor solar cells and the photosynthetic apparatus - to illustrate the basic operation and principles that apply. The existence of a light harvesting unit in photosynthesis has been known since the early 1930's but details of the process - relating, in particular, to the relationship between the structure and spectral properties - are still being unravelled. The excitation energy carriers are excitons but the precise nature of the transport - via the solid state Frenkel-Peierls variety or by Förster's resonant energy transfer - is still subject to debate. In semiconductor solar cells, the energy of the absorbed photon is collected by minority carriers but the broad principles remain the same. In both cases it is shown that the rate of energy conversion is described by a law which parallels the Shockley's solar cell equation, and the light harvesting energy collection is subject to reciprocity relations which resemble Onsager's reciprocity relations between coefficients which couple appropriate forces and flows in non-equilibrium thermodynamics. Differences in the basic atomic make-up in the two systems lead to different energy transport equations. In both cases, however, similar mathematical techniques based on Green

  11. Light water reactor safety

    CERN Document Server

    Pershagen, B

    2013-01-01

    This book describes the principles and practices of reactor safety as applied to the design, regulation and operation of light water reactors, combining a historical approach with an up-to-date account of the safety, technology and operating experience of both pressurized water reactors and boiling water reactors. The introductory chapters set out the basic facts upon which the safety of light water reactors depend. The central section is devoted to the methods and results of safety analysis. The accidents at Three Mile Island and Chernobyl are reviewed and their implications for light wate

  12. Device structure for OLED light device having multi element light extraction and luminescence conversion layer

    Science.gov (United States)

    Antoniadis; Homer , Krummacher; Benjamin Claus

    2008-01-22

    An apparatus such as a light source has a multi-element light extraction and luminescence conversion layer disposed over a transparent layer of the light source and on the exterior of said light source. The multi-element light extraction and luminescence conversion layer includes a plurality of light extraction elements and a plurality of luminescence conversion elements. The light extraction elements diffuses the light from the light source while luminescence conversion elements absorbs a first spectrum of light from said light source and emits a second spectrum of light.

  13. OLED lighting devices having multi element light extraction and luminescence conversion layer

    Science.gov (United States)

    Krummacher, Benjamin Claus; Antoniadis, Homer

    2010-11-16

    An apparatus such as a light source has a multi element light extraction and luminescence conversion layer disposed over a transparent layer of the light source and on the exterior of said light source. The multi-element light extraction and luminescence conversion layer includes a plurality of light extraction elements and a plurality of luminescence conversion elements. The light extraction elements diffuses the light from the light source while luminescence conversion elements absorbs a first spectrum of light from said light source and emits a second spectrum of light.

  14. Hydrophobic Light-to-Heat Conversion Membranes with Self-Healing Ability for Interfacial Solar Heating.

    Science.gov (United States)

    Zhang, Lianbin; Tang, Bo; Wu, Jinbo; Li, Renyuan; Wang, Peng

    2015-09-01

    Self-healing hydrophobic light-to-heat conversion membranes for interfacial solar heating are fabricated by deposition of light-to-heat conversion material of polypyrrole onto a porous stainless-steel mesh, followed by hydrophobic fluoroalkylsilane modification. The mesh-based membranes spontaneously stay at the water-air interface, collect and convert solar light into heat, and locally heat only the water surface for enhanced evaporation.

  15. Hydrophobic Light-to-Heat Conversion Membranes with Self-Healing Ability for Interfacial Solar Heating

    KAUST Repository

    Zhang, Lianbin

    2015-07-01

    Self-healing hydrophobic light-to-heat conversion membranes for interfacial solar heating are fabricated by deposition of light-to-heat conversion material of polypyrrole onto porous stainless steel mesh, followed by hydrophobic fluoroalkylsilane modification. The mesh-based membranes spontaneously stay at the water–air interface, collect and convert solar light into heat, and locally heat only the water surface for an enhanced evaporation.

  16. Light water reactor program

    Energy Technology Data Exchange (ETDEWEB)

    Franks, S.M.

    1994-12-31

    The US Department of Energy`s Light Water Reactor Program is outlined. The scope of the program consists of: design certification of evolutionary plants; design, development, and design certification of simplified passive plants; first-of-a-kind engineering to achieve commercial standardization; plant lifetime improvement; and advanced reactor severe accident program. These program activities of the Office of Nuclear Energy are discussed.

  17. Electrochemical conversion of micropollutants in gray water

    NARCIS (Netherlands)

    Butkovskyi, A.; Jeremiasse, A.W.; Hernandez Leal, L.; Zande, van der T.; Rijnaarts, H.; Zeeman, G.

    2014-01-01

    Electrochemical conversion of micropollutants in real gray water effluent was studied for the first time. Six compounds that are frequently found in personal care and household products, namely methylparaben, propylparaben, bisphenol A, triclosan, galaxolide, and 4- methylbenzilidene camphor

  18. Electrochemical conversion of micropollutants in gray water

    NARCIS (Netherlands)

    Butkovskyi, A.; Jeremiasse, A.W.; Hernandez Leal, L.; Zande, van der T.; Rijnaarts, H.; Zeeman, G.

    2014-01-01

    Electrochemical conversion of micropollutants in real gray water effluent was studied for the first time. Six compounds that are frequently found in personal care and household products, namely methylparaben, propylparaben, bisphenol A, triclosan, galaxolide, and 4- methylbenzilidene camphor (4-MBC)

  19. Light water reactor fuel element suitable for thorium employment in a discrete seed and blanket configuration with the aim to attain conversion ratios above the range of one

    Energy Technology Data Exchange (ETDEWEB)

    Hrovat, M.F.; Grosse, K.H.; Seemann, R. [ALD Vacuum Technologies GmbH, Hanau (Germany)

    2008-07-01

    The thorium resources in the world are relatively large. According to the IAEA-NEA-publication ''Red Book'' they amount to 4.5 10E6 metric tons and are about 4 times greater than the resources of Uranium. The fuel element described in this paper could be used in light water reactor (LWR) preferably in pressurized water reactor (PWR). The seed (feed) rods contain uranium 235 as fissionable material and the blanket (breed) rods contain thorium and uranium. The thorium in the blanket rods is converted to fissionable U-233 by irradiation with thermal neutrons. The U-233 produced is a valuable fissionable material and is characterized by high revalues, where t is defined as the number of fission neutrons per absorption in fissile materials. By optimized configuration and loading of the seed- and blanket rods the thorium is converted to U-233 and the U-238 is converted to fissionable Plutonium isotopes. Consequently more fissionable material is generated than is used. The fuel cycle is also flexible. Thus U-235, Pu-239 or weapons-grade Plutonium can be used.Based on knowledge obtained in the development of fuel elements for material test reactors (MTR), high temperature reactors (HTR) and light water reactors (LWR), a new design of fuel element suitable for thorium employment in PWR is described.

  20. How is the water molecule activated on metalloporphyrins? Oxygenation of substrates induced through one-photon/two-electron conversion in artificial photosynthesis by visible light.

    Science.gov (United States)

    Shimada, Tetsuya; Kumagai, Akihiro; Funyu, Shigeaki; Takagi, Shinsuke; Masui, Dai; Nabetani, Yu; Tachibana, Hiroshi; Tryk, Donald A; Inoue, Haruo

    2012-01-01

    The reaction mechanism of the highly efficient (phi = 0.60), selective photochemical epoxidation of alkenes sensitized by CO-coordinated tetra(2,4,6-trimethyl)phenylporphyrinatoruthenium(II) (Ru(II)TMP(CO)), with water acting both as an electron and oxygen atom donor, was investigated. The steady-state light irradiation of the reaction mixture indicated the formation of the Ru(II)TMP (CO) cation radical under neutral conditions, which was effectively trapped by an hydroxide ion to regenerate the starting sensitizer. By means of a laser flash photolysis experiment, the formation of the cation radical as the primary process from the triplet excited state of Ru(II)TMP(CO) was clearly observed. Four kinds of transients were detected in completely different ranges of the delay time: the excited triplet state of Ru(II)TMP(CO) [delay time region reaction mechanism was revealed that involves RuTMP(CO) cation radical formation from the triplet excited state of the sensitizer, followed by attack of an hydroxide ion to form an hydroxyl-coordinated Ru-porphyrin (Intermediate [I]) and subsequent reaction with cyclohexene to form Intermediate [II]. The kinetics for each step of the successive processes was carefully analyzed and their rate constants were determined. The two-electron oxidation of water by one-photon irradiation, as revealed in the photochemical epoxidation, is proposed to be one of the more promising candidates to get through the bottleneck of water oxidation in artificial photosynthesis.

  1. Light distribution system comprising spectral conversion means

    DEFF Research Database (Denmark)

    2012-01-01

    System (200, 300) for the distribution of white light, having a supply side (201, 301, 401) and a delivery side (202, 302, 402), the system being configured for guiding light with a multitude of visible wavelengths in a propagation direction P from the supply side to the distribution side...

  2. Monomolecular conversion of light alkanes over H-ZSM-5

    NARCIS (Netherlands)

    Narbeshuber, T.; Narbeshuber, Thomas F.; Vinek, Hannelore; Lercher, J.A.

    1995-01-01

    The monomolecular conversion of light n-alkanes (propane to n-hexane) over H-ZSM-5 was investigated between 723 and 823 K. The rates and energies of activation of the individual reactions were determined and a kinetic model for the conversion is presented. The results suggest that carbonium ions are

  3. The Application of Lights-Conversed Polyethylene Film for Agriculture

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Lanthanum-rhodamine (6G and B) complexes were synthesized by Rheological Phase Reaction Method. Lanthanum-rhodamine (6G and B) complexes doped polyethylene films which have a function of lights-conversion were prepared. The emission and excitation spectra were measured. The experiments of growing seedling and culture were carried out in the shed built with doped and undoped polyethylene films. Lanthanum-rhodamine doped polyethylene films which have a function of lights-conversion can efficiently convert the green light in the sunlight to the red light for photosynthesis of crops, to promote the maturing of crops and raise the yield of crops.

  4. Conversion of HOL Light proofs into Metamath

    Directory of Open Access Journals (Sweden)

    Mario M Carneiro

    2016-01-01

    Full Text Available We present an algorithm for converting proofs from the OpenTheory interchange format, which can be translated to and from any of the HOL family of proof languages (HOL4, HOL Light, ProofPower, and Isabelle, into the ZFC-based Metamath language. This task is divided into two steps: the translation of an OpenTheory proof into a Metamath HOL formalization, hol.mm, followed by the embedding of the HOL formalization into the main ZFC foundations of the main Metamath library, set.mm. This process provides a means to link the simplicity of the Metamath foundations to the intense automation efforts which have borne fruit in HOL Light, allowing the production of complete Metamath proofs of theorems in HOL Light, while also proving that HOL Light is consistent, relative to Metamath's ZFC axiomatization.

  5. Light water detritiation

    Energy Technology Data Exchange (ETDEWEB)

    Fedorchenko, O.A.; Aleksee, I.A.; Bondarenko, S.D.; Vasyanina, T.V. [B.P. Konstantinov Petersburg Nuclear Physics Institute of National Research Centre ' Kurchatov Institute' , Gatchina (Russian Federation)

    2015-03-15

    Hundreds of thousands of tons of tritiated light water have been accumulating from the enterprises of nuclear fuel cycles around the world. The Dual-Temperature Water-Hydrogen (DTWH) process looks like the only practical alternative to Combined Electrolysis and Catalytic Exchange (CECE). In DTWH power-consuming lower reflux device (electrolytic cell) is replaced by a so-called 'hot tower' (LPCE column operating at conditions which ensure relatively small value of elementary separation factor α(hot)). In the upper, cold tower, the tritium transfers from hydrogen to water while in the lower, hot tower - in the opposite direction - from water to hydrogen. The DTWH process is much more complicated compared to CECE; it must be thoroughly computed and strictly controlled by an automatic control system. The use of a simulation code for DTWH is absolutely important. The simulation code EVIO-5 deals with 3 flows inside a column (hydrogen gas, water vapour and liquid water) and 2 simultaneous isotope exchange sub-processes (counter-current phase exchange and co-current catalytic exchange). EVIO-5 takes into account the strong dependence of process performance on given conditions (temperature and pressure). It calculates steady-state isotope concentration profiles considering a full set of reversible exchange reactions between different isotope modifications of water and hydrogen (12 molecular species). So the code can be used for simulation of LPCE column operation for detritiation of hydrogen and water feed, which contains H and D not only at low concentrations but above 10 at.% also. EVIO-5 code is used to model a Tritium Removal Facility with a throughput capacity of about 400 m{sup 3}/day. Simulation results show that a huge amount of wet-proofed catalyst is required (about 6000 m{sup 3}), mainly (90%) in the first stage. One reason for these large expenses (apart from a big scale of the problem itself) is the relatively high tritium separation factor in the

  6. MXene Ti3C2: An Effective 2D Light-to-Heat Conversion Material

    KAUST Repository

    Li, Renyuan

    2017-03-25

    MXene, a new series of 2D material, has been steadily advancing its applications to a variety of fields, such as catalysis, supercapacitor, molecular separation, electromagnetic wave interference shielding. This work reports a carefully designed aqueous droplet light heating system along with a thorough mathematical procedure, which combined leads to a precise determination of internal light-to-heat conversion efficiency of a variety of nanomaterials. The internal light-to-heat conversion efficiency of MXene, more specifically Ti3C2, was measured to be 100%, indicating a perfect energy conversion. Furthermore, a self-floating MXene thin membrane was prepared by simple vacuum filtration and the membrane, in the presence of a rationally chosen heat barrier, produced a light-to-water-evaporation efficiency of 84% under one sun irradiation, which is among the state of art energy efficiency for similar photothermal evaporation system. The outstanding internal light-to-heat conversion efficiency and great light-to-water evaporation efficiency reported in this work suggest that MXene is a very promising light-to-heat conversion material and thus deserves more research attention toward practical applications.

  7. Kinetics of coal conversion in supercritical water

    Energy Technology Data Exchange (ETDEWEB)

    Anatoli A. Vostrikov; Sergey A. Psarov; Dmitri Yu. Dubov; Oxana N. Fedyaeva; Mikhail Ya. Sokol [Siberian Branch of the Russian Academy of Sciences, Novosibirsk (Russian Federation). Institute of Thermophysics

    2007-09-15

    Conversion of the coal particle pack in supercritical water (SCW) was studied in the semibatch reactor under the pressure of P = 30 MPa, in the temperature range of T = 500-750{sup o}C, and in the reaction time of t = 60-720 s. The experimental results were analyzed within the framework of homogeneous, nonreacted core, and random pore models. The quantitative composition of conversion products was determined. Dependences of the conversion rate on the degree of coal conversion, reaction time, and temperature were described in an assumption of the first-order reaction and Arrhenius dependence. It was found that activation energy of conversion is E = 103 kJ/mol and the pre-exponential factor is A{sub 0} = 1.3 x 10{sup 3.1} s{sup -1}. It was revealed that coal gasification in SCW without oxidants is the weakly endothermic process. The addition of CO{sub 2} into SCW decreases the conversion rate and increases the CO yield. 20 refs., 8 figs.

  8. Simultaneous cellulose conversion and hydrogen production assisted by cellulose decomposition under UV-light photocatalysis.

    Science.gov (United States)

    Zhang, Guan; Ni, Chengsheng; Huang, Xiubing; Welgamage, Aakash; Lawton, Linda A; Robertson, Peter K J; Irvine, John T S

    2016-01-28

    Photocatalytic conversion of cellulose to sugars and carbon dioxide with simultaneous production of hydrogen assisted by cellulose decomposition under UV or solar light irradiation was achieved upon immobilization of cellulose onto a TiO2 photocatalyst. This approach enables production of hydrogen from water without using valuable sacrificial agents, and provides the possibility for recovering sugars as liquid fuels.

  9. Evaluation of conversion efficiency of light to hydrogen energy by Anabaena variabilis

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, Jong Hyun; Hae Shin, Ji; Park, Tai Hyun [School of Chemical and Biological Engineering, Seoul National University, Seoul 151-744 (Korea, Republic of); Kim, Mi-Sun [Biomass Research Team, Korea Institute of Energy Research, Daejeon 305-343 (Korea, Republic of); Jun Sim, Sang [Department of Chemical Engineering, Sungkyunkwan University, Suwon 440-746 (Korea, Republic of)

    2006-05-15

    Cyanobacteria provide an efficient system for producing H{sub 2} from water using solar energy. The energy conversion efficiency can be defined by the ratio of H{sub 2} produced to the light energy absorbed. An IR and opalescent plate method was used to measure the light energy absorbed. Since cyanobacteria absorb light in the visible range but not in the infrared range, the net amount of light energy absorbed by the cells can be estimated by measuring the IR and visible light intensities transmitted through the biochamber. A rectangular biochamber was used for measuring the conversion efficiency from light energy to H{sub 2} energy. A quantum meter and radiometer were used to measure the light intensity transmitted through the chamber. Anabaena variabilis was cultured in a BG11 medium with 3.6mM NaNO{sub 3} and the light intensity was 40-50{mu}mol/m{sup 2}/s in the growth phase and 120-140{mu}mol/m{sup 2}/s in the H{sub 2} production phase. The maximum H{sub 2} production was 50ml for 40h and cell density was 1.2g/l. The H{sub 2} production rate was 4.1ml H{sub 2}/g dry cell weight/h. Based on the light absorbed in the H{sub 2} production phase, the energy conversion efficiency from light to H{sub 2} was 1.5% on average and 3.9% at the maximum. Based on the light energy absorbed in the cell growth and H{sub 2} production phases, the energy conversion efficiency was 1.1% on average. (author)

  10. Bidirectional conversion between microwave and light via ferromagnetic magnons

    CERN Document Server

    Hisatomi, Ryusuke; Tabuchi, Yutaka; Ishikawa, Toyofumi; Noguchi, Atsushi; Yamazaki, Rekishu; Usami, Koji; Nakamura, Yasunobu

    2016-01-01

    Coherent conversion of microwave and optical photons in the single-quantum level can significantly expand our ability to process signals in various fields. Efficient up-conversion of a feeble signal in the microwave domain to the optical domain will lead to quantum-noise-limited microwave amplifiers. Coherent exchange between optical photons and microwave photons will also be a stepping stone to realize long-distance quantum communication. Here we demonstrate bidirectional and coherent conversion between microwave and light using collective spin excitations in a ferromagnet. The converter consists of two harmonic oscillator modes, a microwave cavity mode and a magnetostatic mode called Kittel mode, where microwave photons and magnons in the respective modes are strongly coupled and hybridized. An itinerant microwave field and a travelling optical field can be coupled through the hybrid system, where the microwave field is coupled to the hybrid system through the cavity mode, while the optical field addresses ...

  11. Power conversion efficiency of non-equilibrium light absorption

    Directory of Open Access Journals (Sweden)

    I. Santamaría-Holek

    2017-04-01

    Full Text Available We deduce a novel expression for the non-equilibrium photochemical potential and the power conversion efficiency of non-equilibrium light absorption by a thermostated material. Application of our results for the case of electron migration from valence to conduction bands in photovoltaic cells allows us to accurately interpolate experimental results for the maximal efficiencies of Ge-, Si-, GaAs-based cells and the like.

  12. High efficiency light source using solid-state emitter and down-conversion material

    Science.gov (United States)

    Narendran, Nadarajah; Gu, Yimin; Freyssinier, Jean Paul

    2010-10-26

    A light emitting apparatus includes a source of light for emitting light; a down conversion material receiving the emitted light, and converting the emitted light into transmitted light and backward transmitted light; and an optic device configured to receive the backward transmitted light and transfer the backward transmitted light outside of the optic device. The source of light is a semiconductor light emitting diode, a laser diode (LD), or a resonant cavity light emitting diode (RCLED). The down conversion material includes one of phosphor or other material for absorbing light in one spectral region and emitting light in another spectral region. The optic device, or lens, includes light transmissive material.

  13. Study on water cooled high conversion reactor

    Energy Technology Data Exchange (ETDEWEB)

    Ochiai, Masaaki [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    1999-12-01

    As a part of study on advanced reactors for the future, conceptual design of high conversion water cooled reactors is being studied, aiming at the contribution to nuclear fuel cycle by the LWR technology, since the utilization of LWRs will extend over a long period of time . We are studying on the reactor core concepts for BWR and PWR reactor systems. As for BWR system, three types of reactor cores are investigating for three different design goals; long operation period, high conversion ratio and high applicability for the existing BWR system. In all the cases, we have obtained a fair prospect of a large core concept with a capacity of 1,000 MWe class having negative void reactivity coefficient. This study is a part of JAERI-JAPCO (Japan Atomic Power Company) cooperative studies. Various kinds of conceptual designs will be created until the end of FY 1999. The designs will be checked and reviewed at that time, then experimental studies on the realization of the concepts will start with further design works from FY 2000. (author)

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

    Science.gov (United States)

    Inoue, Keiichi; Nomura, Yurika; Kandori, Hideki

    2016-05-06

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

  15. Bidirectional conversion between microwave and light via ferromagnetic magnons

    Science.gov (United States)

    Hisatomi, R.; Osada, A.; Tabuchi, Y.; Ishikawa, T.; Noguchi, A.; Yamazaki, R.; Usami, K.; Nakamura, Y.

    2016-05-01

    Coherent conversion of microwave and optical photons in the single quantum level can significantly expand our ability to process signals in various fields. Efficient up-conversion of a feeble signal in the microwave domain to the optical domain will lead to quantum-noise-limited microwave amplifiers. Coherent exchange between optical photons and microwave photons will also be a stepping stone to realize long-distance quantum communication. Here we demonstrate bidirectional and coherent conversion between microwave and light using collective spin excitations in a ferromagnet. The converter consists of two harmonic oscillator modes, a microwave cavity mode and a magnetostatic mode called the Kittel mode, where microwave photons and magnons in the respective modes are strongly coupled and hybridized. An itinerant microwave field and a traveling optical field can be coupled through the hybrid system, where the microwave field is coupled to the hybrid system through the cavity mode, while the optical field addresses the hybrid system through the Kittel mode via Faraday and inverse Faraday effects. The conversion efficiency is theoretically analyzed and experimentally evaluated. The possible schemes for improving the efficiency are also discussed.

  16. Direct conversion of light hydrocarbon gases to liquid fuel

    Energy Technology Data Exchange (ETDEWEB)

    Kaplan, R.D.; Foral, M.J.

    1992-05-16

    Amoco oil Company, has investigated the direct, non-catalytic conversion of light hydrocarbon gases to liquid fuels (particularly methanol) via partial oxidation. The primary hydrocarbon feed used in these studies was natural gas. This report describes work completed in the course of our two-year project. In general we determined that the methanol yields delivered by this system were not high enough to make it economically attractive. Process variables studied included hydrocarbon feed composition, oxygen concentration, temperature and pressure effects, residence time, reactor design, and reactor recycle.

  17. Direct conversion of light hydrocarbon gases to liquid fuel

    Energy Technology Data Exchange (ETDEWEB)

    Kaplan, R.D.; Foral, M.J.

    1992-05-16

    Amoco oil Company, has investigated the direct, non-catalytic conversion of light hydrocarbon gases to liquid fuels (particularly methanol) via partial oxidation. The primary hydrocarbon feed used in these studies was natural gas. This report describes work completed in the course of our two-year project. In general we determined that the methanol yields delivered by this system were not high enough to make it economically attractive. Process variables studied included hydrocarbon feed composition, oxygen concentration, temperature and pressure effects, residence time, reactor design, and reactor recycle.

  18. Dynamic wavelength conversion in copropagating slow-light pulses.

    Science.gov (United States)

    Kondo, K; Baba, T

    2014-06-06

    Dynamic wavelength conversion (DWC) is obtained by controlling copropagating slow-light signal and control pulse trajectories. Our method is based on the understanding that conventional resonator-based DWC can be generalized, and is linked to cross-phase modulation. Dispersion-engineered Si photonic crystal waveguides produce such slow-light pulses. Free carriers generated by two-photon absorption of the control pulse dynamically shift the signal wavelength. Matching the group velocities of the two pulses enhances the shift, elongating the interaction length. We demonstrate an extremely large wavelength shift in DWC (4.9 nm blueshift) for the signal wavelength. Although DWC is similar to the Doppler effect, we highlight their essential differences.

  19. A novel photocatalytic conversion of Tryptophan to Kynurenine using black light as a light source

    NARCIS (Netherlands)

    Hamdy Mohamed Saad, M.S.; Scott, E.L.; Carr, R.H.; Sanders, J.P.M.

    2012-01-01

    The photocatalytic conversion of an aqueous solution of l-tryptophan (Trp) to kynurenine (KN) was investigated under the illumination of different light sources. Results show that Trp converted to KN with a selectivity of 64% under the illumination of a medium pressure (MP) Hg lamp. KN selectivity w

  20. Glycerol and bioglycerol conversion in supercritical water for hydrogen production.

    Science.gov (United States)

    Yu-Wu, Q M; Weiss-Hortala, E; Barna, R; Boucard, H; Bulza, S

    2012-01-01

    Catalytic transesterification of vegetable oils leads to biodiesel and an alkaline feed (bioglycerol and organic residues, such as esters, alcohols. . .). The conversion ofbioglycerol into valuable organic molecules represents a sustainable industrial process leading to the valorization of a renewable organic resource. The physicochemical properties in the supercritical domain (T > 374 degrees C, P > 22.1 MPa) transform water into a solvent for organics and a reactant favouring radical reactions. In this context, the conversion ofbioglycerol in supercritical water (SCW) into platform molecules and/or high energetic gases (hydrogen, hydrocarbons) could represent an interesting valorization process. The reported research results concern the conversion of bioglycerol compared to pure glycerol. The experiments have been done in batch autoclaves (5 ml and 500 ml stirred). Solutions of pure (5 or 10 wt%) and crude (3.5 wt%) glycerol have been processed with or without catalyst (K2CO3 1.5 wt%) in the range of 450-600 degrees C. The molecular formula of bioglycerol was determined as C4.3H9.7O1.8Na0.1Si0.08. Glycerol was partially decomposed in the batch systems during the heating (42% before reaching 420 degrees C) and some intermediates (propanediol, ethylene glycol . . .) were quantified, leading to a proposition of a reaction pathway. Acrolein, a valuable platform molecule, was mainly produced in the absence of catalyst. No solid phase was recovered after SCW conversion of pure and bioglycerol in batch reactors. The optimal parameters for gasification were 600 degrees C, 25 MPa for bioglycerol and 525 degrees C, 25 MPa, for pure glycerol. In these operating conditions, 1 kg of pure or bioglycerol leads to 15 and, respectively, 10 mol of hydrogen. Supercritical water gasification of crude glycerol favoured the generation of light hydrocarbons, while pure glycerol promoted H2 production. SCW conversion of glycerol (pure and crude) allows to obtain simultaneously energetic

  1. Advanced light water reactor plant

    Energy Technology Data Exchange (ETDEWEB)

    Giedraityte, Zivile [Helsinki University of Technology, Otaranta 8D-84, 02150 Espoo (Finland)

    2008-07-01

    For nuclear power to be competitive with the other methods of electrical power generation the economic performance should be significantly improved by increasing the time spent on line generating electricity relative to time spent off-line conducting maintenance and refueling. Maintenance includes planned actions (surveillances) and unplanned actions (corrective maintenance) to respond to component degradation or failure. A methodology is described which is used to resolve maintenance related operating cycle length barriers. Advanced light water nuclear power plant is designed with the purpose to maximize online generating time by increasing operating cycle length. (author)

  2. Role of coal water mixture in utility coal conversion

    Energy Technology Data Exchange (ETDEWEB)

    Bhagat, N.; Butcher, T.

    1984-05-01

    To indicate the role of coal water mixtures (CWM) in utility coal conversions, the pertinent technical, economic, environmental, and regulatory factors involved in CWM conversion are reviewed. CWM technology provides an attractive option for utility companies to convert to coal. There appear to be no major technical problems in CWM production and use that cannot be overcome. Environmental considerations, however, play an important role in utilities' decisions to convert to coal. In general, coal conversions would be seriously impeded if the installation of flue gas desulfurization units cannot be avoided, as it now can because of the DOE program, and they are also inhibited by present uncertainties regarding impending acid rain regulations. Preliminary estimates of the economics of conversion seem attractive; however, site-specific evaluation is needed to justify conversion in a given situation. Although conversion to pulverized coal appears competitive with that to CWM, some non-economic factors tend to favor CWM over PC.

  3. Light Absorbers and Catalysts for Solar to Fuel Conversion

    Science.gov (United States)

    Kornienko, Nikolay I.

    Increasing fossil fuel consumption and the resulting consequences to the environment has propelled research into means of utilizing alternative, clean energy sources. Solar power is among the most promising of renewable energy sources but must be converted into an energy dense medium such as chemical bonds to render it useful for transport and energy storage. Photoelectrochemistry (PEC), the splitting of water into oxygen and hydrogen fuel or reducing CO 2 to hydrocarbon fuels via sunlight is a promising approach towards this goal. Photoelectrochemical systems are comprised of several components, including light absorbers and catalysts. These parts must all synergistically function in a working device. Therefore, the continual development of each component is crucial for the overall goal. For PEC systems to be practical for large scale use, the must be efficient, stable, and composed of cost effective components. To this end, my work focused on the development of light absorbing and catalyst components of PEC solar to fuel converting systems. In the direction of light absorbers, I focused of utilizing Indium Phosphide (InP) nanowires (NWs) as photocathodes. I first developed synthetic techniques for InP NW solution phase and vapor phase growth. Next, I developed light absorbing photocathodes from my InP NWs towards PEC water splitting cells. I studied cobalt sulfide (CoSx) as an earth abundant catalyst for the reductive hydrogen evolution half reaction. Using in situ spectroscopic techniques, I elucidated the active structure of this catalyst and offered clues to its high activity. In addition to hydrogen evolution catalysts, I established a new generation of earth abundant catalysts for CO2 reduction to CO fuel/chemical feedstock. I first worked with molecularly tunable homogeneous catalysts that exhibited high selectivity for CO2 reduction in non-aqueous media. Next, in order to retain molecular tunability while achieving stability and efficiency in aqueous

  4. Effect of light conversion agent on luminous properties of a new down-converting material SrAl2O4:Eu2+,Dy3+/light conversion agent

    Institute of Scientific and Technical Information of China (English)

    朱亚楠; 逄增媛; 王建; 葛明桥; 孙思瑾; 胡泽华; 翟佳鹤; 高佳欣; 姜伏生

    2016-01-01

    A new luminous materialSrAl2O4:Eu2+,Dy3+/light conversion agent that can emit red light in the darkness after being ex-cited was fabricated by combining light conversion agent on to SrAl2O4:Eu2+,Dy3+particles through YsiX3. The morphology of the luminous materials was analyzed by scan electron microscopy (SEM). The emission behavior was evaluated by fluorescence spec-trophotometric analysis and the results demonstrated that the emission spectra of samples had a redshift compared to SrAl2O4:Eu2+, Dy3+ and the emission intensity rose dramatically atfirst and then decreased when the ratio of light conversion agentdoping was over 1.4 wt.%. And the emission color of SrAl2O4:Eu2+,Dy3+/light conversion agent was tuned from green (SrAl2O4:Eu2+,Dy3+) to or-ange-red. Furthermore, the afterglow property was also investigated, and the results indicated that the afterglow brightness reached 6.5 cd/m2, and as the light conversion agent concentration increased the brightness intensity decreased.

  5. Fractional conversion of microalgae from water blooms.

    Science.gov (United States)

    Zhou, Yingdong; Li, Linling; Zhang, Rui; Hu, Changwei

    2017-09-21

    Fractional conversion of natural algae cyanobacteria from Taihu Lake was conducted. The raw Taihu Lake algae (TLA) and pretreated samples were pyrolyzed at 290 °C and 450 °C according to the TGA results. Extraction of lipids or saccharides from the TLA was performed as a pretreatment to obtain lipid extracted algae (LEA) or saccharide extracted algae (SEA). The total yields of bio-oil from fractional pyrolysis were 40.9 wt% from TLA, 42.3 wt% from LEA, and 48.5 wt% from SEA. From TLA, the major components of the bio-oil were fatty acids, amides and hydrocarbons (heptadecane) at 290 °C whereas those at 450 °C were phenols and C10-C15 hydrocarbons. Following the lipid extraction, acids, amides and indoles accounted for a large proportion at 290 °C, while the main products obtained at 450 °C were phenols, indoles and pyrroles. It is worth mentioning that the yield of bio-oil from the LEA had increased, and the composition of the bio-oil was simplified. Moreover, the average molecular weight of the bio-oil obtained from LEA had decreased. Interestingly, the extraction of saccharides inhibited pyrolysis of the lipids, so the distribution of the bio-oil from SEA changed only a little. Fractional pyrolysis of pretreated microalgae not only increased the bio-oil yield but also improved the quality of the bio-oil.

  6. Optomechanical Light-Matter Interface with Optical Wavelength Conversion

    Science.gov (United States)

    2015-07-21

    Conversion Hailin Wang Department of Physics , University of Oregon, Eugene, OR 97403 Lin Tian School of Natural Science, University of California...the physical process can be exactly mapped to a cooling equation where the mechanical noise is extracted away from the system. In the physical ... electromechanical systems. Mechanically-mediated 14 DISTRIBUTION A: Distribution approved for public release. optical wavelength conversion, including

  7. Light Conversion and Scattering in UV Protective Textiles

    Directory of Open Access Journals (Sweden)

    Grancarić Ana Marija

    2014-12-01

    Full Text Available The primary cause of skin cancer is believed to be a long exposure to solar ultraviolet radiation (UV-R crossed with the amount of skin pigmentation in the population. It is believed that in childhood and adolescence 80% of UV-R gets absorbed, whilst in the remaining 20% gets absorbed later in the lifetime. This suggests that proper and early photoprotection may reduce the risk of subsequent occurrence of skin cancer. Textile and clothing are the most suitable interface between environment and human body. It can show UV protection, but in most cases it does not provide full sun screening properties. UV protection ability highly depends on large number of factors such as type of fibre, fabric surface and construction, type and concentration of dyestuff, fluorescent whitening agent (FWA, UV-B protective agents, as well as nanoparticles, if applied. Based on electronically excited state by energy of UV-R (usually 340-370 nm, the molecules of FWAs show the phenomenon of fluorescence giving to white textiles high whiteness of outstanding brightness by reemitting the energy at the blue region (typically 420-470 nm of the spectrum. By absorbing UV-A radiation, optical brightened fabrics transform this radiation into blue fluorescence, which leads to better UV protection. Natural zeolites are rock-forming, microporous silicate minerals. Applied as nanoparticles to textile surface, it scatters the UV-R resulting in lower UV-A and UV-B transmission. If applied with other UV absorbing agents, e.g. FWAs, synergistic effect occurs. Silicones are inert, synthetic compounds with a variety of forms and uses. It provides a unique soft touch, is very resistant to washing and improves the property of fabric to protect against UV radiation. Therefore, the UV protective properties of cotton fabric achieved by light conversion and scattering was researched in this paper. For that purpose, the stilbene-derived FWAs were applied on cotton fabric in wide concentration

  8. Orbital angular momentum light frequency conversion and interference with quasi-phase matching crystals

    CERN Document Server

    Zhou, Zhi-Yuan; Jiang, Yun-Kun; Li, Yan; Shi, Shuai; Wang, Xi-Shi; Shi, Bao-Sen; Guo, Guang-Can

    2014-01-01

    Light with helical phase structures, carrying quantized orbital angular momentum (OAM), has many applications in both classical and quantum optics, such as high-capacity optical communications and quantum information processing. Frequency conversion is a basic technique to expand the frequency range of fundamental light. The frequency conversion of OAM-carrying light gives rise to new physics and applications such as up-conversion detection of images and high dimensional OAM entanglements. Quasi-phase matching (QPM) nonlinear crystals are good candidates for frequency conversion, particularly for their high-valued effective nonlinear coefficients and no walk-off effect. Here we report the first experimental second-harmonic generation (SHG) of OAM light with a QPM crystal, where a UV light with OAM of 100 is generated. OAM conservation is verified using a specially designed interferometer. With a pump beam carrying an OAM superposition of opposite sign, we observed interesting interference phenomena in the SHG...

  9. Effect of Water on Ethanol Conversion over ZnO

    Energy Technology Data Exchange (ETDEWEB)

    Rahman, Muhammad Mahfuzur; Davidson, Stephen D.; Sun, Junming; Wang, Yong

    2015-10-01

    This work focuses on understanding the role of water on ethanol conversion over zinc oxide (ZnO). It was found that a competitive adsorption between ethanol and water occurs on ZnO, which leads to the blockage of the strong Lewis acid site by water on ZnO. As a result, both dehydration and dehydrogenation reactions are inhibited. However, the extent of inhibition for dehydration is orders of magnitude higher than that for dehydrogenation, leading to the shift of reaction pathway from ethanol dehydration to dehydrogenation. In the secondary reactions for acetaldehyde conversion, water inhibits the acetaldehyde aldol-condensation to crotonaldehyde, favoring the oxidation of acetaldehyde to acetic acid, and then to acetone via ketonization at high temperature (i.e., 400 °C).

  10. Highly efficient frequency conversion with bandwidth compression of quantum light

    CERN Document Server

    Allgaier, Markus; Sansoni, Linda; Quiring, Viktor; Ricken, Raimund; Harder, Georg; Brecht, Benjamin; Silberhorn, Christine

    2016-01-01

    Hybrid quantum networks rely on efficient interfacing of dissimilar quantum nodes, since elements based on parametric down-conversion sources, quantum dots, color centres or atoms are fundamentally different in their frequencies and bandwidths. While pulse manipulation has been demonstrated in very different systems, to date no interface exists that provides both an efficient bandwidth compression and a substantial frequency translation at the same time. Here, we demonstrate an engineered sum-frequency-conversion process in Lithium Niobate that achieves both goals. We convert pure photons at telecom wavelengths to the visible range while compressing the bandwidth by a factor of 7.47 under preservation of non-classical photon-number statistics. We achieve internal conversion efficiencies of 75.5%, significantly outperforming spectral filtering for bandwidth compression. Our system thus makes the connection between previously incompatible quantum systems as a step towards usable quantum networks.

  11. Improvement on Mixograph test through water addition and parameter conversions

    Institute of Scientific and Technical Information of China (English)

    SUN Jia-zhu[1; YANG Wen-long[1; LIU Dong-cheng[1; ZHAO Jun-tao[2; LUO Guang-bin[1; LI Xin[1; LIU Yan-jun[3; GUO Jin-kao[3; ZHANG Ai-min[1

    2015-01-01

    To improve Mixograph testing effect, Farinograph measurements were adopted as a quality standard and changes in water absorption and parameter conversion in Mixograph test were explored. Comparative study showed that increasing water absorption to about 73% and converting original parameters to compound parameters in Mixograph tests significantly increased their predictive power for flour quality. These efforts also enabled the adoption of fixed water addition level in Mixograph test and simplified the test procedure significantly. With the success in parameter conversions, Mixograph test results were successfully described by Farinograph parameters, which allow breeders to compare and exchange test results easily. All these changes optimized the official method of Mixograph test with simplified procedure and enhanced reliability and made the Mixograph being the superior tool for quality assessment in wheat-breeding programs.

  12. Improvement on Mixograph test through water addition and parameter conversions

    Institute of Scientific and Technical Information of China (English)

    SUN Jia-zhu; YANG Wen-long; LIU Dong-cheng; ZHAO Jun-tao; LUO Guang-bin; LI Xin; LIU Yan-jun; GUO Jin-kao; ZHANG Ai-min

    2015-01-01

    To improve Mixograph testing effect, Farinograph measurements were adopted as a quality standard and changes in water absorption and parameter conversion in Mixograph test were explored. Comparative study showed that increasing water absorption to about 73% and converting original parameters to compound parameters in Mixograph tests signiifcantly increased their predictive power for lfour quality. These efforts also enabled the adoption of ifxed water addition level in Mixograph test and simpliifed the test procedure signiifcantly. With the success in parameter conversions, Mixograph test results were successful y described by Farinograph parameters, which al ow breeders to compare and exchange test results easily. Al these changes optimized the ofifcial method of Mixograph test with simpliifed procedure and enhanced reliability and made the Mixograph being the superior tool for quality assessment in wheat-breeding programs.

  13. Spectral light management for solar energy conversion systems

    Directory of Open Access Journals (Sweden)

    Stanley Cameron

    2016-06-01

    Full Text Available Due to the inherent broadband nature of the solar radiation, combined with the narrow spectral sensitivity range of direct solar to electricity devices, there is a massive opportunity to manipulate the solar spectrum to increase the functionality and efficiency of solar energy conversion devices. Spectral splitting or manipulation facilitates the efficient combination of both high-temperature solar thermal systems, which can absorb over the entire solar spectrum to create heat, and photovoltaic cells, which only convert a range of wavelengths to electricity. It has only recently been possible, with the development of nanofabrication techniques, to integrate micro- and nano-photonic structures as spectrum splitters/manipulators into solar energy conversion devices. In this paper, we summarize the recent developments in beam splitting techniques, and highlight some relevant applications including combined PV-thermal collectors and efficient algae production, and suggest paths for future development in this field.

  14. Highly efficient frequency conversion with bandwidth compression of quantum light

    Science.gov (United States)

    Allgaier, Markus; Ansari, Vahid; Sansoni, Linda; Eigner, Christof; Quiring, Viktor; Ricken, Raimund; Harder, Georg; Brecht, Benjamin; Silberhorn, Christine

    2017-01-01

    Hybrid quantum networks rely on efficient interfacing of dissimilar quantum nodes, as elements based on parametric downconversion sources, quantum dots, colour centres or atoms are fundamentally different in their frequencies and bandwidths. Although pulse manipulation has been demonstrated in very different systems, to date no interface exists that provides both an efficient bandwidth compression and a substantial frequency translation at the same time. Here we demonstrate an engineered sum-frequency-conversion process in lithium niobate that achieves both goals. We convert pure photons at telecom wavelengths to the visible range while compressing the bandwidth by a factor of 7.47 under preservation of non-classical photon-number statistics. We achieve internal conversion efficiencies of 61.5%, significantly outperforming spectral filtering for bandwidth compression. Our system thus makes the connection between previously incompatible quantum systems as a step towards usable quantum networks. PMID:28134242

  15. Highly efficient frequency conversion with bandwidth compression of quantum light

    Science.gov (United States)

    Allgaier, Markus; Ansari, Vahid; Sansoni, Linda; Eigner, Christof; Quiring, Viktor; Ricken, Raimund; Harder, Georg; Brecht, Benjamin; Silberhorn, Christine

    2017-01-01

    Hybrid quantum networks rely on efficient interfacing of dissimilar quantum nodes, as elements based on parametric downconversion sources, quantum dots, colour centres or atoms are fundamentally different in their frequencies and bandwidths. Although pulse manipulation has been demonstrated in very different systems, to date no interface exists that provides both an efficient bandwidth compression and a substantial frequency translation at the same time. Here we demonstrate an engineered sum-frequency-conversion process in lithium niobate that achieves both goals. We convert pure photons at telecom wavelengths to the visible range while compressing the bandwidth by a factor of 7.47 under preservation of non-classical photon-number statistics. We achieve internal conversion efficiencies of 61.5%, significantly outperforming spectral filtering for bandwidth compression. Our system thus makes the connection between previously incompatible quantum systems as a step towards usable quantum networks.

  16. Spectral light management for solar energy conversion systems

    Science.gov (United States)

    Stanley, Cameron; Mojiri, Ahmad; Rosengarten, Gary

    2016-06-01

    Due to the inherent broadband nature of the solar radiation, combined with the narrow spectral sensitivity range of direct solar to electricity devices, there is a massive opportunity to manipulate the solar spectrum to increase the functionality and efficiency of solar energy conversion devices. Spectral splitting or manipulation facilitates the efficient combination of both high-temperature solar thermal systems, which can absorb over the entire solar spectrum to create heat, and photovoltaic cells, which only convert a range of wavelengths to electricity. It has only recently been possible, with the development of nanofabrication techniques, to integrate micro- and nano-photonic structures as spectrum splitters/manipulators into solar energy conversion devices. In this paper, we summarize the recent developments in beam splitting techniques, and highlight some relevant applications including combined PV-thermal collectors and efficient algae production, and suggest paths for future development in this field.

  17. Visible Light Excitation Characteristics of Novel Infrared Up-conversion Materials

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The Fluorescence excitation spectrum, emission spectrum and infrared up-conversion luminescence excitation spectrum are measured. The results of spectrum measurement show that the electron trapping materials CaS: Eu, Sm are of visible light excitation. The mechanism of visible light excitation is analyzed.

  18. Toward visible light response: Overall water splitting using heterogeneous photocatalysts

    KAUST Repository

    Takanabe, Kazuhiro

    2011-01-01

    Extensive energy conversion of solar energy can only be achieved by large-scale collection of solar flux. The technology that satisfies this requirement must be as simple as possible to reduce capital cost. Overall water splitting by powder-form photocatalysts directly produces a mixture of H 2 and O2 (chemical energy) in a single reactor, which does not require any complicated parabolic mirrors and electronic devices. Because of its simplicity and low capital cost, it has tremendous potential to become the major technology of solar energy conversion. Development of highly efficient photocatalysts is desired. This review addresses why visible light responsive photocatalysts are essential to be developed. The state of the art for the photocatalysts for overall water splitting is briefly described. Moreover, various fundamental aspects for developing efficient photocatalysts, such as particle size of photocatalysts, cocatalysts, and reaction kinetics are discussed. Copyright © 2011 De Gruyter.

  19. Scalable time reversal of Raman echo quantum memory and quantum waveform conversion of light pulse

    CERN Document Server

    Moiseev, E S

    2013-01-01

    We have found the new hidden symmetry of time reversal light-atom interaction in the photon echo quantum memory with Raman atomic transition. The time-reversed quantum memory provides generalized condition for ideal compression/decompression of time duration and wavelength conversion of the input light pulse. Based on a general analytical approach to this scheme, we have studied the optimal conditions of the light field compression/decompression in resonant atomic systems characterized by realistic spectral properties. The demonstrated effective quantum conversion of the light waveform and wavelength are also discussed for various possible realizations of the quantum memory scheme. The performed study promises new capabilities for fundamental study of the light-atom interaction and for deterministic quantum manipulation of the light field interested for quantum communication and quantum computing.

  20. Light-harvesting materials: Soft support for energy conversion

    Energy Technology Data Exchange (ETDEWEB)

    Stolley, Ryan M.; Helm, Monte L.

    2014-11-10

    To convert solar energy into viable fuel sources, coupling light-harvesting materials to catalysts is a critical challenge. Now, coupling between an organic supramolecular hydrogel and a non precious metal catalyst has been demonstrated to be effective for photocatalytic H2 production. Ryan M. Stolley and Monte L. Helm are at Pacific Northwest National Laboratory (PNNL), Richland, WA, USA 99352. PNNL is operated by Battelle for the US Department of Energy. e-mail: Monte.Helm@pnnl.gov

  1. Light/electricity conversion by defined cocultures of Chlamydomonas and Geobacter.

    Science.gov (United States)

    Nishio, Koichi; Hashimoto, Kazuhito; Watanabe, Kazuya

    2013-04-01

    Biological energy-conversion systems are attractive in terms of their self-organizing and self-sustaining properties and are expected to be applied towards environmentally friendly bioenergy processes. Recent studies have demonstrated that sustainable light/electricity-conversion systems, termed microbial solar cells (MSCs), can be constructed using naturally occurring microbial communities. To better understand the energy-conversion mechanisms in microbial communities, the present study attempted to construct model MSCs comprised of defined cocultures of a green alga, Chlamydomonas reinhardtii, and an iron-reducing bacterium, Geobacter sulfurreducens, and examined their metabolism and interactions in MSCs. When MSC bioreactors were inoculated with these microbes and irradiated on a 12-h light/dark cycle, periodic current was generated in the dark with energy-conversion efficiencies of 0.1%. Metabolite analyses revealed that G. sulfurreducens generated current by oxidizing formate that was produced by C. reinhardtii in the dark. These results demonstrate that the light/electricity conversion occurs via syntrophic interactions between phototrophs and electricity-generating bacteria. Based on the results and data in literatures, it is estimated that the excretion of organics by the phototroph was the bottleneck step in the syntrophic light/electricity conversion. We also discuss differences between natural-community and defined-coculture MSCs.

  2. Polymerization contraction and conversion of light-curing BisGMA-based methacrylate resins.

    Science.gov (United States)

    Venhoven, B A; de Gee, A J; Davidson, C L

    1993-09-01

    The aim of this study was to investigate the polymerization contraction and the conversion of light-curing methacrylate resins based on bisphenol-A bis(2-hydroxypropyl)methacrylate (BisGMA) diluted with triethylene glycol dimethyacrylate (TEGDMA), methyl methacrylate (MMA), hydroxypropyl methacrylate (HPMA) or (+/-)-2-ethylhexyl methacrylate (EHMA). The contraction measurements were carried out with a linometer, a simple device to determine true linear polymerization contraction of liquid monomers at ambient temperature. The contraction increased with the amount of diluting monomer. The estimated conversion of the BisGMA-TEGDMA, calculated using the contraction, is consistent with literature values. The BisGMA-HPMA mixtures showed high conversions at moderate contraction.

  3. Multichannel mode conversion and multiplexing based on a single spatial light modulator for optical communication

    Science.gov (United States)

    Nie, Song; Yu, Song; Cai, Shanyong; Lan, Mingying; Gu, Wanyi

    2016-07-01

    A method is proposed to achieve multichannel mode conversion and multiplexing by dividing a single spatial light modulator into several blocks with the mode conversion pattern and blazed grating loaded on each block. The conversion patterns realize the precise excitation of higher order modes using combined amplitude and phase modulation. The blazed gratings bring together incident beams, so these beams can be coupled into few-mode fiber (FMF). In the experiment, four higher order modes are precisely excited and converge with a tilt angle. Through the simulation method, these beams can be coupled into FMF with small tilt angles (0.0344 deg for LP11 mode).

  4. Solar energy conversion by photocatalytic overall water splitting

    KAUST Repository

    Takanabe, Kazuhiro

    2015-07-04

    Summary: Solar energy is abundant and renewable energy: however, extensive conversion of the solar energy can only be achieved by large-scale collection of solar flux. The technology that satisfies this requirement must be as simple as possible to reduce capital cost. Overall water splitting (OWS) by powder-form photocatalysts directly produces H2 as a chemical energy in a single reactor, which does not require any complicated parabolic mirrors and electronic devices. Because of its simplicity and low capital cost, it has tremendous potential to become the major technology of solar energy conversion. To achieve the OWS efficiently, the development of efficient photocatalysts is mandatory. The OWS hotocatalysis involves the electrocatalys is for both water reduction and oxidation on the surafce of photocatalysts, which is driven by particular semiconductors that absorb photons to generate excited carriers. Such photocatalysts must be designed to maximize the charge separation efficiency at the catalyst-semiconductor and semiconductor-electrolyte interface. In addition the low-overpotential electrocatalyts towards water redox reactions should be insensitive to the back-reaction of the produced H2 and O2 that produces H2O. In this presentation, some recent progress on the topic of the OWS in our group will be discussed.

  5. Low insertion loss highly mode-selective spatial multiplexers using multi-plane light conversion

    Science.gov (United States)

    Morizur, Jean-François; Barré, Nicolas; Pinel, Olivier; Lenglé, Kevin; Garcia, Lionel; Jaffres, Lionel; Jian, Pu; Labroille, Guillaume

    2016-02-01

    Multi-Plane Light Conversion enables novel beam shaping devices, including spatial multiplexers. After a presentation of the achievable performances of these spatial multiplexers, which can combine 10 spatial modes with cross-talk below -22 dB and insertion loss below 4 dB, we review the performances of Multi-Plane Light Con-version in multiple application cases. These application cases include mode-multiplexed optical amplification, high-power beam shaping and combining and LAN fiber capacity upgrade.

  6. Luminescence properties of Eu3+/CDs/PVA composite applied in light conversion film

    Science.gov (United States)

    He, Jiangling; He, Youling; Zhuang, Jianle; Zhang, Haoran; Lei, Bingfu; Liu, Yingliang

    2016-12-01

    In this work, blue-light-emitting carbon dots (CDs) were composited with red-light-emitting europium ions (Eu3+) solutions under the synergistic reaction of polyvinyl alcohol (PVA) to prepare the light conversion film. The formation mechanism of Eu3+/CDs/PVA film was detailedly discussed. It is the first report that this composite was synthesized through direct recombination of CDs and Eu3+ solutions instead of traditional methods based on Eu3+ coordination compound. Furthermore, tunable photoluminescence property can be successfully achieved by controlling the ratio of CDs to doped Eu3+, this property can meet the variable light component requirements for different species of plants.

  7. Supercritical-pressure light water cooled reactors

    CERN Document Server

    Oka, Yoshiaki

    2014-01-01

    This book focuses on the latest reactor concepts, single pass core and experimental findings in thermal hydraulics, materials, corrosion, and water chemistry. It highlights research on supercritical-pressure light water cooled reactors (SCWRs), one of the Generation IV reactors that are studied around the world. This book includes cladding material development and experimental findings on heat transfer, corrosion and water chemistry. The work presented here will help readers to understand the fundamental elements of reactor design and analysis methods, thermal hydraulics, materials and water

  8. Advances in light water reactor technologies

    CERN Document Server

    Saito, Takehiko; Ishiwatari, Yuki; Oka, Yoshiaki

    2010-01-01

    ""Advances in Light Water Reactor Technologies"" focuses on the design and analysis of advanced nuclear power reactors. This volume provides readers with thorough descriptions of the general characteristics of various advanced light water reactors currently being developed worldwide. Safety, design, development and maintenance of these reactors is the main focus, with key technologies like full MOX core design, next-generation digital I&C systems and seismic design and evaluation described at length. This book is ideal for researchers and engineers working in nuclear power that are interested

  9. InP/ZnS nanocrystals for colour conversion in white light emitting diodes

    DEFF Research Database (Denmark)

    Shirazi, Roza

    In this work a comprehensive study of a colloidal InP/ZnS nanocrystals (NC) as the colour conversion material for white light emitting diodes (WLED) is shown. Studied nanocrystals were synthesised by wet chemistry using one pot, hot injection method. A quantum efficiency (QE) of photoluminescence...

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

    CSIR Research Space (South Africa)

    Zhang, Y

    2014-08-01

    Full Text Available We present a simple way of simulating Spontaneous parametric down-conversion (SPDC) by modulating a classical laser beam with two spatial light modulators (SLM) through a back projection setup. This system has the advantage of having very high...

  11. Conversion and conservation of light energy in a photosynthetic microbial mat ecology

    DEFF Research Database (Denmark)

    Al-Najjar, Mohammad; Jørgensen, Bo Barker; de Beer, Dirk

    2010-01-01

    : in light-limiting conditions, 95.5% of the absorbed light energy dissipated as heat and 4.5% was channeled into photosynthesis. This energy disproportionation changed in favor of heat dissipation at increasing irradiance, with >99% of the absorbed light energy being dissipated as heat and ...Here we present, to the best of our knowledge, the first balanced light energy budget for a benthic microbial mat ecosystem, and show how the budget and the spatial distribution of the local photosynthetic efficiencies within the euphotic zone depend on the absorbed irradiance (Jabs). Our approach...... uses microscale measurements of the rates of heat dissipation, gross photosynthesis and light absorption in the system, and a model describing light propagation and conversion in a scattering–absorbing medium. The energy budget was dominated by heat dissipation on the expense of photosynthesis...

  12. Conversion and conservation of light energy in a photosynthetic microbial mat ecosystem

    DEFF Research Database (Denmark)

    Al-Najjar, A.A.; De Beer, D.; Jørgensen, B. B.

    2011-01-01

    : in light-limiting conditions, 95.5% of the absorbed light energy dissipated as heat and 4.5% was channeled into photosynthesis. This energy disproportionation changed in favor of heat dissipation at increasing irradiance, with >99% of the absorbed light energy being dissipated as heat and 700 micromol......Here we present, to the best of our knowledge, the first balanced light energy budget for a benthic microbial mat ecosystem, and show how the budget and the spatial distribution of the local photosynthetic efficiencies within the euphotic zone depend on the absorbed irradiance (J(abs)). Our...... approach uses microscale measurements of the rates of heat dissipation, gross photosynthesis and light absorption in the system, and a model describing light propagation and conversion in a scattering-absorbing medium. The energy budget was dominated by heat dissipation on the expense of photosynthesis...

  13. The muon-positron conversion in nuclei mediated by light Majorana neutrinos

    CERN Document Server

    Simkovic, F; Kovalenko, S V; Faessler, A; Faessler, Amand

    2001-01-01

    We study the lepton number violating muon-positron conversion in nuclei mediated by the exchange of virtual light Majorana neutrinos. We found that a previously overlooked imaginary part of this amplitude plays an important role. The numerical calculation has been made for the experimentally interesting muon-positron conversion in Ti48 using realistic renormalized proton-neutron QRPA wave functions. We also discuss the very similar case of the neutrinoless double beta decay of Ca48 The ratio of muon-positron conversion over the total muon absorption has been computed taking into account the current constraints from neutrino oscillation phenomenology. We compare our results with the experimental limits as well as with previous theoretical predictions. We have found that the Majorana neutrino mode of muon-positron conversion in Ti48 is too small to be measurable in the foreseeable future.

  14. Conversion of CO2 via Visible Light Promoted Homogeneous Redox Catalysis

    Directory of Open Access Journals (Sweden)

    Bernhard Rieger

    2012-11-01

    Full Text Available This review gives an overview on the principles of light-promoted homogeneous redox catalysis in terms of applications in CO2 conversion. Various chromophores and the advantages of different structures and metal centers as well as optimization strategies are discussed. All aspects of the reduction catalyst site are restricted to CO2 conversion. An important focus of this review is the question of a replacement of the sacrificial donor which is found in most of the current publications. Furthermore, electronic parameters of supramolecular systems are reviewed with reference to the requisite of chromophores, oxidation and reduction sites.

  15. Superacid catalysis of light hydrocarbon conversion. Final report, August 26, 1993--August 26, 1996

    Energy Technology Data Exchange (ETDEWEB)

    Gates, B.C.

    1996-12-31

    Motivated by the goal of finding improved catalysts for low- temperature conversion of light alkanes into fuel components or precursors of fuel components, the researchers have investigated sulfated zirconia and promoted sulfated zirconia for conversion of butane, propane, and ethane. Catalyst performance data for sulfated zirconia promoted with iron and manganese show that it is the most active noncorrosive, nonhalide catalyst known for n-butane isomerization, and it is an excellent candidate catalyst for new low- temperature n-butane isomerization processes to make isobutane, which can be converted by established technology into methyl t-butyl ether (MTBE). Various transition metals have been found to work as promoters of sulfated zirconia for n-butane isomerization. The combination of iron and manganese is the best known combination of promoters yet discovered. The iron- and manganese-promoted sulfated zirconia is also a catalyst for conversion of propane and of ethane. Ethane is converted into ethylene and butanes in the presence of the iron- and manganese-promoted sulfated zirconia; propane is also converted into butane, among other products. However, the activities of the catalyst for these reactions are orders of magnitude less than the activity for n-butane conversion, and there is no evidence that the catalyst would be of practical value for conversion of alkanes lighter than butane. The product distribution data for ethane and propane conversion provide new insights into the nature of the catalyst and its acidity. These data suggest the involvement of Olah superacid chemistry, whereby the catalyst protonates the alkane itself, giving carbonium ions (as transition states). The mechanism of protonation of the alkane may also pertain to the conversion of butane, but there is good evidence that the butane conversion also proceeds via alkene intermediates by conventional mechanisms of carbenium ion formation and rearrangement.

  16. Fe-modified HZSM-5 catalysts for ethanol conversion into light olefins

    Institute of Scientific and Technical Information of China (English)

    Jiangyin Lu; Yancong Liu; Na Li

    2011-01-01

    A series of Fe/HZSM-5 catalysts with different iron loadings were prepared by impregnation method.Characterization was performed by N2 adsorption-desorption,X-ray diffraction (XRD),NH3 temperature-programmed desorption (NH3-TPD),temperature-programmed reduction (TPR),temperature-programmed oxidation (TPO) and thermogravimetry (TG) analysis.Iron content in the synthesized samples varied from 1.1 wt% to 20 wt%.The obtained samples have been used for ethanol conversion into light olefins.It was found that the amount of strong acidity at 300-550 ℃ on Fe-modified samples was decreased,going with another new acid site appearance at 550-600 ℃ and that Fe/HZSM-5 catalysts were highly selective towards light olefins,especially the 9FZ sample.In addition,Fe-modified catalysts suppressed the conversion of ethanol to aromatics and paraffins and enhanced their anti-carbon deposit ability.

  17. A Palladium-Binding Deltarhodopsin for Light-Activated Conversion of Protonic to Electronic Currents.

    Science.gov (United States)

    Soto-Rodríguez, Jessica; Hemmatian, Zahra; Josberger, Erik E; Rolandi, Marco; Baneyx, François

    2016-08-01

    Fusion of a palladium-binding peptide to an archaeal rhodopsin promotes intimate integration of the lipid-embedded membrane protein with a palladium hydride protonic contact. Devices fabricated with the palladium-binding deltarhodopsin enable light-activated conversion of protonic currents to electronic currents with on/off responses complete in seconds and a nearly tenfold increase in electrical signal relative to those made with the wild-type protein.

  18. Hybrid lead halide perovskites for light energy conversion: Excited state properties and photovoltaic applications

    Science.gov (United States)

    Manser, Joseph S.

    travel 220 nm over the course of 2 ns after photoexcitation, with an extrapolated diffusion length greater than one micrometer over the full excited state lifetime. The solution-processability of metal halide perovskites necessarily raises questions as to the properties of the solvated precursors and their connection to the final solid-state perovskite phase. Through structural and steady-state and time-resolved absorption studies, the important link between the excited state properties of the precursor components, composed of solvated and solid-state halometallate complexes, and CH3NH3PbI3 is evinced. This connection provides insight into optical nonlinearities and electronic properties of the perovskite phase. Fundamental studies of CH 3NH3PbI3 ultimately serve as a foundation for application of this and other related materials in high-performance devices. In the final chapter, the operation of CH3NH3PbI 3 solar cells in a tandem architecture is presented. The quest for economic, large scale hydrogen production has motivated the search for new materials and device designs capable of splitting water using only energy from the sun. In light of this, we introduce an all solution-processed tandem water splitting assembly composed of a BiVO4 photoanode and a single-junction CH3NH3PbI3 hybrid perovskite solar cell. This unique configuration allows efficient solar photon management, with the metal oxide photoanode selectively harvesting high energy visible photons and the underlying perovskite solar cell capturing lower energy visible-near IR wavelengths in a single-pass excitation. Operating without external bias under standard terrestrial one sun illumination, the photoanode-photovoltaic architecture, in conjunction with an earthabundant cobalt phosphate catalyst, exhibits a solar-to-hydrogen conversion efficiency of 2.5% at neutral pH. The design of low-cost tandem water splitting assemblies employing single-junction hybrid perovskite materials establishes a potentially

  19. Principles, efficiency, and blueprint character of solar-energy conversion in photosynthetic water oxidation.

    Science.gov (United States)

    Dau, Holger; Zaharieva, Ivelina

    2009-12-21

    Photosynthesis in plants and cyanobacteria involves two protein-cofactor complexes which are denoted as photosystems (PS), PSII and PSI. These solar-energy converters have powered life on earth for approximately 3 billion years. They facilitate light-driven carbohydrate formation from H(2)O and CO(2), by oxidizing the former and reducing the latter. PSII splits water in a process driven by light. Because all attractive technologies for fuel production driven by solar energy involve water oxidation, recent interest in this process carried out by PSII has increased. In this Account, we describe and apply a rationale for estimating the solar-energy conversion efficiency (eta(SOLAR)) of PSII: the fraction of the incident solar energy absorbed by the antenna pigments and eventually stored in form of chemical products. For PSII at high concentrations, approximately 34% of the incident solar energy is used for creation of the photochemistry-driving excited state, P680*, with an excited-state energy of 1.83 eV. Subsequent electron transfer results in the reduction of a bound quinone (Q(A)) and oxidation of the Tyr(Z) within 1 micros. This radical-pair state is stable against recombination losses for approximately 1 ms. At this level, the maximal eta(SOLAR) is 23%. After the essentially irreversible steps of quinone reduction and water oxidation (the final steps catalyzed by the PSII complex), a maximum of 50% of the excited-state energy is stored in chemical form; eta(SOLAR) can be as high as 16%. Extending our considerations to a photosynthetic organism optimized to use PSII and PSI to drive H(2) production, the theoretical maximum of the solar-energy conversion efficiency would be as high as 10.5%, if all electrons and protons derived from water oxidation were used for H(2) formation. The above performance figures are impressive, but they represent theoretical maxima and do not account for processes in an intact organism that lower these yields, such as light saturation

  20. Glass transition and degree of conversion of a light-cured orthodontic composite

    Directory of Open Access Journals (Sweden)

    Michela M. D. S. Sostena

    2009-12-01

    Full Text Available OBJECTIVE: This study evaluated the glass transition temperature (Tg and degree of conversion (DC of a light-cured (Fill Magic versus a chemically cured (Concise orthodontic composite. MATERIAL AND METHODS: Anelastic relaxation spectroscopy was used for the first time to determine the Tg of a dental composite, while the DC was evaluated by infrared spectroscopy. The light-cured composite specimens were irradiated with a commercial LED light-curing unit using different exposure times (40, 90 and 120 s. RESULTS: Fill Magic presented lower Tg than Concise (35-84ºC versus 135ºC, but reached a higher DC. CONCLUSIONS: The results of this study suggest that Fill Magic has lower Tg than Concise due to its higher organic phase content, and that when this light-cured composite is used to bond orthodontic brackets, a minimum energy density of 7.8 J/cm² is necessary to reach adequate conversion level and obtain satisfactory adhesion.

  1. High conversion pressurized water reactor with boiling channels

    Energy Technology Data Exchange (ETDEWEB)

    Margulis, M., E-mail: maratm@post.bgu.ac.il [The Unit of Nuclear Engineering, Ben Gurion University of the Negev, POB 653, Beer Sheva 84105 (Israel); Shwageraus, E., E-mail: es607@cam.ac.uk [Department of Engineering, University of Cambridge, CB2 1PZ Cambridge (United Kingdom)

    2015-10-15

    Highlights: • Conceptual design of partially boiling PWR core was proposed and studied. • Self-sustainable Th–{sup 233}U fuel cycle was utilized in this study. • Seed-blanket fuel assembly lattice optimization was performed. • A coupled Monte Carlo, fuel depletion and thermal-hydraulics studies were carried out. • Thermal–hydraulic analysis assured that the design matches imposed safety constraints. - Abstract: Parametric studies have been performed on a seed-blanket Th–{sup 233}U fuel configuration in a pressurized water reactor (PWR) with boiling channels to achieve high conversion ratio. Previous studies on seed-blanket concepts suggested substantial reduction in the core power density is needed in order to operate under nominal PWR system conditions. Boiling flow regime in the seed region allows more heat to be removed for a given coolant mass flow rate, which in turn, may potentially allow increasing the power density of the core. In addition, reduced moderation improves the breeding performance. A two-dimensional design optimization study was carried out with BOXER and SERPENT codes in order to determine the most attractive fuel assembly configuration that would ensure breeding. Effects of various parameters, such as void fraction, blanket fuel form, number of seed pins and their dimensions, on the conversion ratio were examined. The obtained results, for which the power density was set to be 104 W/cm{sup 3}, created a map of potentially feasible designs. It was found that several options have the potential to achieve end of life fissile inventory ratio above unity, which implies potential feasibility of a self-sustainable Thorium fuel cycle in PWRs without significant reduction in the core power density. Finally, a preliminary three-dimensional coupled neutronic and thermal–hydraulic analysis for a single seed-blanket fuel assembly was performed. The results indicate that axial void distribution changes drastically with burnup. Therefore

  2. Magnesium diboride: An effective light-to-heat conversion material in solid-state

    Science.gov (United States)

    John, Saju K.; John, Daughty; Bijoy, N.; Chathanathodi, Raghu; Anappara, Aji A.

    2017-07-01

    We report herein a giant light-to-heat transduction observed in bulk magnesium diboride (MgB2) on exposure to incoherent, continuous wave, broadband light-sources. The heat-flow from the sample was accurately determined using photocalorimetry, to register an ultrahigh value of 45 W/g upon irradiation with a low-pressure mercury vapour lamp (λ ˜ 250-450 nm; irradiance ˜800 mW/cm2) with a photo-to-thermal conversion efficiency of about 83% (with an error of ±1.86%). As a practical application, light-induced heat was used to generate electrical power using a thermoelectric generator (open voltage ˜125 mV, when illuminated by a solar simulator). The bulk MgB2 powder was found to be photo-stable under different irradiation conditions, and the photothermal effect was found to be highly reproducible.

  3. Is light water reactor technology sustainable?

    Energy Technology Data Exchange (ETDEWEB)

    Rothwell, G. [Stanford Univ., Dept. of Economics, CA (United States); Van der Zwaan, B. [Vrije Univ., Amsterdam, Inst. for Environmental Studies (Netherlands)

    2001-07-01

    This paper proposes criteria for determining ''intermediate sustainability'' over a 500-year horizon. We apply these criteria to Light Water Reactor (LWR) technology and the LWR industry. We conclude that LWR technology does not violate intermediate sustainability criteria for (1) environmental externalities, (2) worker and public health and safety, or (3) accidental radioactive release. However, it does not meet criteria to (1) efficiently use depleted uranium and (2) avoid uranium enrichment technologies that can lead to nuclear weapons proliferation. Finally, current and future global demand for LWR technology might be below the minimum needed to sustain the current global LWR industry. (author)

  4. Single-beam water vapor detection system with automatic photoelectric conversion gain control

    Science.gov (United States)

    Zhu, C. G.; Chang, J.; Wang, P. P.; Wang, Q.; Wei, W.; Liu, Z.; Zhang, S. S.

    2014-11-01

    A single-beam optical sensor system with automatic photoelectric conversion gain control is proposed for doing high reliability water vapor detection under relatively rough environmental conditions. Comparing to a dual-beam system, it can distinguish the finer photocurrent variations caused by the optical power drift and provide timely compensation by automatically adjusting the photoelectric conversion gain. This system can be rarely affected by the optical power drift caused by fluctuating ambient temperature or variation of fiber bending loss. The deviation of the single-beam system is below 1.11% when photocurrent decays due to fiber bending loss for bending radius of 5 mm, which is obviously lower than the dual-beam system (8.82%). We also demonstrate the long-term stability of the single-beam system by monitoring a 660 ppm by volume (ppmv) water vapor sample continuously for 24 h. The maximum deviation of the measured concentration during the whole testing period does not exceed 10 ppmv. Experiments have shown that the new system features better reliability and is more apt for remote sensing application which is often subject to light transmission loss.

  5. Three-Port dc-dc Conversion in Light-to-Light Systems

    DEFF Research Database (Denmark)

    Mira Albert, Maria del Carmen

    Renewable energies, like solar or wind, provide unlimited, clean and free energy that helps reducing (CO2) emissions, which alleviates global warming and greenhouse effects. Moreover, the ability to produce off-grid electricity allows local electric power generation. However, the main disadvantage...... of the major renewable energies because the Sun is a vast, inexhaustible and clean resource. Photovoltaic cells transform sunlight into electrical energy and the generated power is proportional to the amount of solar irradiation. Light-emitting diodes (LEDs) present higher luminous efficiency and lifetime than....... Solar powered systems are particularly challenging in locations far from the equator, where the solar resource is scarce, especially during winter, since the amount of solar irradiation is small and the length of the day is short. Therefore, these systems need to be optimized by maximizing the energy...

  6. Improvement of Lifetime Using Transition Metal-Incorporated SAPO-34 Catalysts in Conversion of Dimethyl Ether to Light Olefins

    National Research Council Canada - National Science Library

    Kim, Hyo-Sub; Lee, Su-Gyung; Kim, Young-Ho; Lee, Dong-Hee; Lee, Jin-Bae; Park, Chu-Sik

    2013-01-01

    Transition metal (Mn, Fe, or Ni) incorporated SAPO-34 (MeAPSO-34) nanocatalysts were synthesized using a hydrothermal method to improve the catalytic lifetime in the conversion of dimethyl ether to light olefins (DTO...

  7. Direct conversion of light hydrocarbon gases to liquid fuel. Final report No. 33

    Energy Technology Data Exchange (ETDEWEB)

    Kaplan, R.D.; Foral, M.J.

    1992-05-16

    Amoco oil Company, has investigated the direct, non-catalytic conversion of light hydrocarbon gases to liquid fuels (particularly methanol) via partial oxidation. The primary hydrocarbon feed used in these studies was natural gas. This report describes work completed in the course of our two-year project. In general we determined that the methanol yields delivered by this system were not high enough to make it economically attractive. Process variables studied included hydrocarbon feed composition, oxygen concentration, temperature and pressure effects, residence time, reactor design, and reactor recycle.

  8. Efficiency and stability of a phosphor-conversion white light source using a blue laser diode

    Directory of Open Access Journals (Sweden)

    G. Ledru

    2014-10-01

    Full Text Available A white light source using direct phosphor-conversion excited by a blue laser diode is presented. In this preliminary study we have investigated the influence of phosphor’s thickness and operating current of the laser diode over the (x, y chromaticity coordinates, Correlated Color Temperature (CCT and Color Rendering Index (CRI. The best values found were 4000 K and 94. A 40 lm/W luminous efficacy was achieved together with a CRI close to 90 for an operating current of 0.8 A. Those values, to the best of our knowledge, were not previously reported in the literature.

  9. Direct conversion of light hydrocarbon gases to liquid fuel. Final report No. 33

    Energy Technology Data Exchange (ETDEWEB)

    Kaplan, R.D.; Foral, M.J.

    1992-05-16

    Amoco oil Company, has investigated the direct, non-catalytic conversion of light hydrocarbon gases to liquid fuels (particularly methanol) via partial oxidation. The primary hydrocarbon feed used in these studies was natural gas. This report describes work completed in the course of our two-year project. In general we determined that the methanol yields delivered by this system were not high enough to make it economically attractive. Process variables studied included hydrocarbon feed composition, oxygen concentration, temperature and pressure effects, residence time, reactor design, and reactor recycle.

  10. High power laser-driven ceramic phosphor plate for outstanding efficient white light conversion in application of automotive lighting.

    Science.gov (United States)

    Song, Young Hyun; Ji, Eun Kyung; Jeong, Byung Woo; Jung, Mong Kwon; Kim, Eun Young; Yoon, Dae Ho

    2016-08-09

    We report on Y3Al5O12: Ce(3+) ceramic phosphor plate (CPP) using nano phosphor for high power laser diode (LD) application for white light in automotive lighting. The prepared CPP shows improved luminous properties as a function of Ce(3+) concentration. The luminous properties of the Y3Al5O12: Ce(3+) CPP nano phosphor are improved when compared to the Y3Al5O12: Ce(3+) CPP with bulk phosphor, and hence, the luminous emittance, luminous flux, and conversion efficiency are improved. The Y3Al5O12: Ce(3+) CPP with an optimal Ce(3+) content of 0.5 mol % shows 2733 lm/mm(2) value under high power blue radiant flux density of 19.1 W/mm(2). The results indicate that Y3Al5O12: Ce(3+) CPP using nano phosphor can serve as a potential material for solid-state laser lighting in automotive applications.

  11. Luminescence properties of SrB4O7:Sm2+ for light conversion agent

    Institute of Scientific and Technical Information of China (English)

    SUN Jiayue; ZHU Jicheng; LIU Xiaotang; DU Haiyan

    2012-01-01

    A deep red-emitting SrB4O7:Sm2+ phosphor for light conversion agent was synthesized by the conventional solid-state reaction.X-ray powder diffraction (XRD) analysis confirmed the phase formation of SrB4O7:Sm2+ materials.Results of luminescence properties showed that the phosphor could be efficiently excited by the UV-vis light region from 250-500 nm,and it exhibited deep red (685 nm) emission corresponding to 5D0→7F0 transition of Sm2+.The critical quenching concentration of Sm2+ in SrB4O7:Sm2+ phosphor was about 0.05,and the corresponding concentration quenching mechanism was verified to be the dipole-dipole interaction according to the Dexter's theory.The decay times had few alterations with different concentrations in SrB4O7:xSm2+ phosphor.

  12. Catalytic conversion of light alkanes, Phase 1. Topical report, January 1990--January 1993

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1993-12-31

    The authors have found a family of new catalytic materials which, if successfully developed, will be effective in the conversion of light alkanes to alcohols or other oxygenates. Catalysts of this type have the potential to convert natural gas to clean-burning high octane liquid fuels directly without requiring the energy-intensive steam reforming step. In addition they also have the potential to upgrade light hydrocarbons found in natural gas to a variety of high value fuel and chemical products. In order for commercially useful processes to be developed, increases in catalytic life, reaction rate and selectivity are required. Recent progress in the experimental program geared to the further improvement of these catalysts is outlined.

  13. Warm white LED light by frequency down-conversion of mixed yellow and red Lumogen

    Science.gov (United States)

    Mosca, Mauro; Caruso, Fulvio; Zambito, Leandro; Seminara, Biagio; Macaluso, Roberto; Calı, Claudio; Feltin, Eric

    2013-05-01

    This work reports on the benefits and promising opportunities offered by white LED hybrid technology, based on a mixing perylene-based dyes in order to obtain a warm white light for frequency-down conversion. In a standard Ce:YAG-based white LED, the white light appears cold due to the weakness of red wavelength components in the emission spectrum. In order to obtain a warmer white, one possible solution is to add a red phosphor to the yellow one to move the chromatic coordinates properly, though the luminous efficiency drastically decreases due to the increased light absorption of the coating layer. It is generally believed that the low efficiency of warm white LEDs is the main issue today for LED-based lighting. Using photoluminescence of Lumogen® F Yellow 083, a perylene-based polymer dye commercialized by BASF, and adding a small quantity of another perylene-based dye, Lumogen® F Red 305 (BASF), we obtained high-efficiency warm white LEDs by yellow and red conversion from a standard 450 nm GaN/InGaN royal blue LED. Different weight proportions of dyes were dissolved in solutions with equal amounts of poly-methyl-methacrylate (PMMA) in ethyl acetate, then the LEDs were dip-coated in each solution and optically characterized. Record values of 8.03 lm of luminous flux and 116.11 lm/W of optical efficiency were achieved. Finally, the effects of both driving current, and pump wavelength on LED performances - such as chromatic coordinates, correlated color temperature, color rendering index (CRI), and optical efficiency - were investigated.

  14. Light energy conversion into H{sub 2} by Anabaena variabilis mutant PK84 dense cultures exposed to nitrogen limitations

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Jianguo [Institute of Oceanology, Chinese Academy of Sciences, 7 Nanhai Road, Qingdao 266071 (China); Bukatin, Vyacheslav E.; Tsygankov, Anatoly A. [Institute of Basic Biological Problem, Russia Academy of Sciences, Pushchino, Moscow Region 142292 (Russian Federation)

    2006-09-15

    Concentrated cultures (25-86mgChl al{sup -1}) of Anabaena variabilis PK84 were incubated under 99% Ar+1% CO{sub 2} atmosphere in the photobioreactor made of coaxial cylinders. Under illumination equal to 353{mu}Em{sup -2}s{sup -1} they produced hydrogen with the rate more than 20mll{sup -1}h{sup -1} for several days. The efficiency of light energy conversion into H{sub 2} was approx. 1% and did not depend significantly on initial Chl a concentration. H{sub 2}/O{sub 2} ratio reached 41.5% of theoretical value for water photolysis. Data indicate that dense cultures might be used for outdoor systems under direct sun light. Supra-optimal temperatures 36{sup |}C were not harmful for cultures even for 2 days period. Short-term incubation of cultures under 36{sup |}C even increased H{sub 2} production rate and efficiency of light energy bioconversion by 1.25 times. (author)

  15. Light water reactor lower head failure analysis

    Energy Technology Data Exchange (ETDEWEB)

    Rempe, J.L.; Chavez, S.A.; Thinnes, G.L. [EG and G Idaho, Inc., Idaho Falls, ID (United States)] [and others

    1993-10-01

    This document presents the results from a US Nuclear Regulatory Commission-sponsored research program to investigate the mode and timing of vessel lower head failure. Major objectives of the analysis were to identify plausible failure mechanisms and to develop a method for determining which failure mode would occur first in different light water reactor designs and accident conditions. Failure mechanisms, such as tube ejection, tube rupture, global vessel failure, and localized vessel creep rupture, were studied. Newly developed models and existing models were applied to predict which failure mechanism would occur first in various severe accident scenarios. So that a broader range of conditions could be considered simultaneously, calculations relied heavily on models with closed-form or simplified numerical solution techniques. Finite element techniques-were employed for analytical model verification and examining more detailed phenomena. High-temperature creep and tensile data were obtained for predicting vessel and penetration structural response.

  16. Radiation Protection at Light Water Reactors

    CERN Document Server

    Prince, Robert

    2012-01-01

    This book is aimed at Health Physicists wishing to gain a better understanding of the principles and practices associated with a light water reactor (LWR) radiation protection program. The role of key program elements is presented in sufficient detail to assist practicing radiation protection professionals in improving and strengthening their current program. Details related to daily operation and discipline areas vital to maintaining an effective LWR radiation protection program are presented. Programmatic areas and functions important in preventing, responding to, and minimizing radiological incidents and the importance of performing effective incident evaluations and investigations are described. Elements that are integral in ensuring continuous program improvements are emphasized throughout the text.

  17. Commercial Light Water Reactor Tritium Extraction Facility

    Energy Technology Data Exchange (ETDEWEB)

    McHood, M D

    2000-10-12

    A geotechnical investigation program has been completed for the Commercial Light Water Reactor - Tritium Extraction Facility (CLWR-TEF) at the Savannah River Site (SRS). The program consisted of reviewing previous geotechnical and geologic data and reports, performing subsurface field exploration, field and laboratory testing, and geologic and engineering analyses. The purpose of this investigation was to characterize the subsurface conditions for the CLWR-TEF in terms of subsurface stratigraphy and engineering properties for design and to perform selected engineering analyses. The objectives of the evaluation were to establish site-specific geologic conditions, obtain representative engineering properties of the subsurface and potential fill materials, evaluate the lateral and vertical extent of any soft zones encountered, and perform engineering analyses for slope stability, bearing capacity and settlement, and liquefaction potential. In addition, provide general recommendations for construction and earthwork.

  18. Water Footprints and ‘Pozas’: Conversations about Practices and Knowledges of Water Efficiency

    Directory of Open Access Journals (Sweden)

    Carolina Domínguez Guzmán

    2017-01-01

    Full Text Available In this article we present two logics of water efficiency: that of the Water Footprint and that of mango smallholder farmers on the desert coast of Peru (in Motupe. We do so in order to explore how both can learn from each other and to discuss what happens when the two logics meet. Rather than treating the Water Footprint as scientific, in the sense that it is separate from traditions or politics, and Motupe poza irrigation as cultural and, therefore, thick with local beliefs and superstitions, we describe both as consisting of intricate entanglements of knowledge and culture. This produces a more or less level playing field for the two water logics to meet and for proponents of each to enter into a conversation with one another; allowing furthermore for the identification of what Water Footprint inventors and promotors can learn from poza irrigators, and vice versa. The article concludes that important water wisdom may get lost when the Water Footprint logic becomes dominant, as is currently about to happen in Peru.

  19. Catalytic conversion of light alkanes. Quarterly progress report, April 1--June 30, 1992

    Energy Technology Data Exchange (ETDEWEB)

    Lyons, J.E.

    1992-06-30

    The second Quarterly Report of 1992 on the Catalytic Conversion of Light Alkanes reviews the work done between April 1, 1992 and June 31, 1992 on the Cooperative Agreement. The mission of this work is to devise a new catalyst which can be used in a simple economic process to convert the light alkanes in natural gas to oxygenate products that can either be used as clean-burning, high octane liquid fuels, as fuel components or as precursors to liquid hydrocarbon uwspomdon fuel. During the past quarter we have continued to design, prepare, characterize and test novel catalysts for the mild selective reaction of light hydrocarbons with air or oxygen to produce alcohols directly. These catalysts are designed to form active metal oxo (MO) species and to be uniquely active for the homolytic cleavage of the carbon-hydrogen bonds in light alkanes producing intermediates which can form alcohols. We continue to investigate three molecular environments for the active catalytic species that we are trying to generate: electron-deficient macrocycles (PHASE I), polyoxometallates (PHASE II), and regular oxidic lattices including zeolites and related structures as well as other molecular surface structures having metal oxo groups (PHASE I).

  20. Catalytic conversion of light alkanes: Quarterly report, January 1-March 31, 1992

    Energy Technology Data Exchange (ETDEWEB)

    Biscardi, J.; Bowden, P.T.; Durante, V.A.; Ellis, P.E. Jr.; Gray, H.B.; Gorbey, R.G.; Hayes, R.C.; Hodge, J.; Hughes, M.; Langdale, W.A.; Lyons, J.E.; Marcus, B.; Messick, D.; Merrill, R.A.; Moore, F.A.; Myers, H.K. Jr.; Seitzer, W.H.; Shaikh, S.N.; Tsao, W.H.; Wagner, R.W.; Warren, R.W.; Wijesekera, T.P.

    1997-05-01

    The first Quarterly Report of 1992 on the Catalytic Conversion of Light Alkanes reviews the work done between January 1. 1992 and March 31, 1992 on the Cooperative Agreement. The mission of this work is to devise a new catalyst which can be used in a simple economic process to convert the light alkanes in natural gas to oxygenate products which can either be used as clean-burning, high octane liquid fuels, as fuel components or as precursors to liquid hydrocarbon transportation fuel. During the past quarter we have continued to design, prepare, characterize and test novel catalysts for the mild selective reaction of light hydrocarbons with air or oxygen to produce alcohols directly. These catalysts are designed to form active metal oxo (MO) species and to be uniquely active for the homolytic cleavage of the carbon-hydrogen bonds in light alkanes producing intermediates which can form alcohols. We continue to investigate three molecular environments for the active catalytic species that we are trying to generate: electron-deficient porphryinic macrocycles (PHASE I), polyoxometallates (PHASE II), and regular oxidic lattices including zeolites and related structures as well as other molecular surface structures having metal oxo groups (PHASE III).

  1. Catalytic conversion of light alkanes phase II. Topical report, January 1990--January 1993

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-12-31

    The Topical Report on Phase II of the project entitled, Catalytic Conversion of Light Alkanes reviews work done between January 1, 1990 and September 30, 1992 on the Cooperative Agreement. The mission of this work is to devise a new catalyst which can be used in a simple economic process to convert the light alkanes in natural gas to oxygenate products which can either be used as clean-burning, high octane liquid fuels, as fuel components or as precursors to liquid hydrocarbon transportation fuel. This Topical Report documents our efforts to design, prepare, characterize and test novel catalysts for the mild selective reaction of light hydrocarbons with air or oxygen to produce alcohols directly. These catalysts are designed to form active metal oxo (MO) species and to be uniquely active for the homolytic cleavage of the carbon-hydrogen bonds in light alkanes producing intermediates which can form alcohols. Research on the Cooperative Agreement is divided into three Phases relating to three molecular environments for the active catalytic species that we are trying to generate. In this report we present our work on catalysts which have oxidation-active metals in polyoxoanions (PHASE II).

  2. Environmentally assisted cracking in light water reactors

    Energy Technology Data Exchange (ETDEWEB)

    Chopra, O.K.; Chung, H.M.; Gruber, E.E. [and others

    1996-07-01

    This report summarizes work performed by Argonne National Laboratory on fatigue and environmentally assisted cracking (EAC) in light water reactors (LWRs) from April 1995 to December 1995. Topics that have been investigated include fatigue of carbon and low-alloy steel used in reactor piping and pressure vessels, EAC of Alloy 600 and 690, and irradiation-assisted stress corrosion cracking (IASCC) of Type 304 SS. Fatigue tests were conducted on ferritic steels in water that contained various concentrations of dissolved oxygen (DO) to determine whether a slow strain rate applied during different portions of a tensile-loading cycle are equally effective in decreasing fatigue life. Crack-growth-rate tests were conducted on compact-tension specimens from several heats of Alloys 600 and 690 in simulated LWR environments. Effects of fluoride-ion contamination on susceptibility to intergranular cracking of high- and commercial- purity Type 304 SS specimens from control-tensile tests at 288 degrees Centigrade. Microchemical changes in the specimens were studied by Auger electron spectroscopy and scanning electron microscopy to determine whether trace impurity elements may contribute to IASCC of these materials.

  3. Series circuit of organic thin-film solar cells for conversion of water into hydrogen.

    Science.gov (United States)

    Aoki, Atsushi; Naruse, Mitsuru; Abe, Takayuki

    2013-07-22

    A series circuit of bulk hetero-junction (BHJ) organic thin-film solar cells (OSCs) is investigated for electrolyzing water to gaseous hydrogen and oxygen. The BHJ OSCs applied consist of poly(3-hexylthiophene) as a donor and [6,6]-phenyl C61 butyric acid methyl ester as an acceptor. A series circuit of six such OSC units has an open circuit voltage (V(oc)) of 3.4 V, which is enough to electrolyze water. The short circuit current (J(sc)), fill factor (FF), and energy conversion efficiency (η) are independent of the number of unit cells. A maximum electric power of 8.86 mW cm(-2) is obtained at the voltage of 2.35 V. By combining a water electrolysis cell with the series circuit solar cells, the electrolyzing current and voltage obtained are 1.09 mA and 2.3 V under a simulated solar light irradiation (100 mW cm(-2), AM1.5G), and in one hour 0.65 mL hydrogen is generated.

  4. Environmentally assisted cracking in light water reactors.

    Energy Technology Data Exchange (ETDEWEB)

    Chopra, O. K.; Chung, H. M.; Clark, R. W.; Gruber, E. E.; Shack, W. J.; Soppet, W. K.; Strain, R. V.

    2007-11-06

    This report summarizes work performed by Argonne National Laboratory on fatigue and environmentally assisted cracking (EAC) in light water reactors (LWRs) from January to December 2002. Topics that have been investigated include: (a) environmental effects on fatigue crack initiation in carbon and low-alloy steels and austenitic stainless steels (SSs), (b) irradiation-assisted stress corrosion cracking (IASCC) of austenitic SSs in BWRs, (c) evaluation of causes and mechanisms of irradiation-assisted cracking of austenitic SS in PWRs, and (d) cracking in Ni-alloys and welds. A critical review of the ASME Code fatigue design margins and an assessment of the conservation in the current choice of design margins are presented. The existing fatigue {var_epsilon}-N data have been evaluated to define the effects of key material, loading, and environmental parameters on the fatigue lives of carbon and low-alloy steels and austenitic SSs. Experimental data are presented on the effects of surface roughness on fatigue crack initiation in these materials in air and LWR environments. Crack growth tests were performed in BWR environments on SSs irradiated to 0.9 and 2.0 x 10{sup 21} n x cm{sup -2}. The crack growth rates (CGRs) of the irradiated steels are a factor of {approx}5 higher than the disposition curve proposed in NUREG-0313 for thermally sensitized materials. The CGRs decreased by an order of magnitude in low-dissolved oxygen (DO) environments. Slow-strain-rate tensile (SSRT) tests were conducted in high-purity 289 C water on steels irradiated to {approx}3 dpa. The bulk S content correlated well with the susceptibility to intergranular SCC in 289 C water. The IASCC susceptibility of SSs that contain >0.003 wt. % S increased drastically. bend tests in inert environments at 23 C were conducted on broken pieces of SSRT specimens and on unirradiated specimens of the same materials after hydrogen charging. The results of the tests and a review of other data in the literature

  5. Photoelectric conversion performances of Mn doped TiO2 under >420 nm visible light irradiation

    Directory of Open Access Journals (Sweden)

    Lijie Wang

    2015-09-01

    Full Text Available Mn doped TiO2 was synthesized by hydrothermal treatment of titanium boride and manganese chloride. The doped nano powders were fabricated by adding ammonium water into the mother solution which was obtained hydrothermally. The calcination of precursory powders took place at the temperature of 400–600 °C which resulted in the formation of anatase with a small amount of rutile phase. The shift of valence band maximum (VBM toward the lower binding energies was observed by measuring the position of VBM with reference to the Fermi level, which contributed to the significant red-shift of absorption edges. X-ray photoelectron spectroscopy (XPS measurement shows that manganese exists in both 4+ and 3+ valance states, which may have a temperate replacing of Ti4+ because of the charge compensation compared with 2+ and 3+ valence states. The property of photoelectric conversion was detected by evaluating the photocurrent under visible light (>420 nm, and the fluorescence spectra also proved that 6%-Mn doped TiO2 (DM6 shows a better photoelectric conversion performance.

  6. Visible Light Activated Photocatalytic Water Polishing System Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This proposal targets development of a LED light activated photocatalytic water polishing system that enables reduction of organic impurities (TOC and...

  7. Solar-energy conversion and light emission in an atomic monolayer p-n diode.

    Science.gov (United States)

    Pospischil, Andreas; Furchi, Marco M; Mueller, Thomas

    2014-04-01

    The limitations of the bulk semiconductors currently used in electronic devices-rigidity, heavy weight and high costs--have recently shifted the research efforts to two-dimensional atomic crystals such as graphene and atomically thin transition-metal dichalcogenides. These materials have the potential to be produced at low cost and in large areas, while maintaining high material quality. These properties, as well as their flexibility, make two-dimensional atomic crystals attractive for applications such as solar cells or display panels. The basic building blocks of optoelectronic devices are p-n junction diodes, but they have not yet been demonstrated in a two-dimensional material. Here, we report a p-n junction diode based on an electrostatically doped tungsten diselenide (WSe2) monolayer. We present applications as a photovoltaic solar cell, a photodiode and a light-emitting diode, and obtain light-power conversion and electroluminescence efficiencies of ∼ 0.5% and ∼ 0.1%, respectively. Given recent advances in the large-scale production of two-dimensional crystals, we expect them to profoundly impact future developments in solar, lighting and display technologies.

  8. Effect of Water on HEMA Conversion by FT-IR Spectroscopy

    Directory of Open Access Journals (Sweden)

    TS. Jafarzadeh Kashi

    2007-09-01

    Full Text Available Objective: The use of HEMA as a biocompatible material in dentin bonding systems and its potential for clinical applications has been well established. Excess water can affect conversion of bonding resins. The aim of this study was to survey the effect of water on the degree of conversion of HEMA by Fourier Transform Infra-red Spectroscopy (FT-IR.Materials and Methods: In this experimental study, distilled water was added in amounts of 0, 0.05, 0.1, 0.2, and 0.4 ml to 1 ml of curable HEMA solution. Six repetitions per wa-ter ratio were made and investigated. Each sample was polymerized for 60 seconds. De-gree of conversion was obtained from the absorbance IR-Spectrum of the materials before and after polymerization by FT-IR spectroscopy. One way ANOVA and Tukey-HSD were carried out to compare and detect any differences among groups.Results: Statistical analysis indicates highly significant difference between pairs of groups at level (P<0.001. The results showed a trend of decreasing in HEMA conversion with increasing water. Degree of conversion changes significantly within the 0.05 ml to 0.2 ml water range. However, degree of conversion did not change after reaching 0.02 ml and before 0.05.Conclusion: Degree of conversion of HEMA decreased by increasing water. The most dramatic effect of water on the polymerization process occurs within a range which exists under clinical conditions. The reason that the degree of conversion did not show signifi-cant result before 0.05 ml may be related to the hydrophilic nature of HEMA.

  9. Photoelectrochemical water splitting: optimizing interfaces and light absorption

    NARCIS (Netherlands)

    Park, S.

    2015-01-01

    In this thesis several photoelectrochemical water splitting devices based on semiconductor materials were investigated. The aim was the design, characterization, and fabrication of solar-to-fuel devices which can absorb solar light and split water to produce hydrogen.

  10. Multi-channel up-conversion infrared spectrometer and method of detecting a spectral distribution of light

    DEFF Research Database (Denmark)

    2015-01-01

    A multi-channel infrared spectrometer for detecting an infrared spectrum of light received from an object. The spectrometer comprises a wavelength converter system comprising a nonlinear material and having an input side and an output side. The wavelength converter system comprises at least a first...... on the first side into light in a second output wavelength range output on the second side. The spectrometer further comprises a demultiplexer configured for demultiplexing light in the first up-conversion channel and light in the second up-conversion channel. The demultiplexer is located on the first side...... or the second side of the wavelength converter system. Finally, the spectrometer comprises a spatially resolved detector arranged in the image plane to detect light in the first output wavelength range and second output wavelength range output of the wavelength converter system....

  11. Recent advances in visible-light-responsive photocatalysts for hydrogen production and solar energy conversion--from semiconducting TiO2 to MOF/PCP photocatalysts.

    Science.gov (United States)

    Horiuchi, Yu; Toyao, Takashi; Takeuchi, Masato; Matsuoka, Masaya; Anpo, Masakazu

    2013-08-28

    The present perspective describes recent advances in visible-light-responsive photocatalysts intended to develop novel and efficient solar energy conversion technologies, including water splitting and photofuel cells. Water splitting is recognized as one of the most promising techniques to convert solar energy as a clean and abundant energy resource into chemical energy in the form of hydrogen. In recent years, increasing concern is directed to not only the development of new photocatalytic materials but also the importance of technologies to produce hydrogen and oxygen separately. Photofuel cells can convert solar energy into electrical energy by decomposing bio-related compounds and livestock waste as fuels. The advances of photocatalysts enabling these solar energy conversion technologies have been going on since the discovery of semiconducting titanium dioxide materials and have extended to organic-inorganic hybrid materials, such as metal-organic frameworks and porous coordination polymers (MOF/PCP).

  12. The effect of curing light and chemical catalyst on the degree of conversion of two dual cured resin luting cements.

    Science.gov (United States)

    Souza-Junior, Eduardo José; Prieto, Lúcia Trazzi; Soares, Giulliana Panfiglio; Dias, Carlos Tadeu dos Santos; Aguiar, Flávio Henrique Baggio; Paulillo, Luís Alexandre Maffei Sartini

    2012-01-01

    The aim of this study was to evaluate the influence of different curing lights and chemical catalysts on the degree of conversion of resin luting cements. A total of 60 disk-shaped specimens of RelyX ARC or Panavia F of diameter 5 mm and thickness 0.5 mm were prepared and the respective chemical catalyst (Scotchbond Multi-Purpose Plus or ED Primer) was added. The specimens were light-cured using different curing units (an argon ion laser, an LED or a quartz-tungsten-halogen light) through shade A2 composite disks of diameter 10 mm and thickness 2 mm. After 24 h of dry storage at 37°C, the degree of conversion of the resin luting cements was measured by Fourier-transformed infrared spectroscopy. For statistical analysis, ANOVA and the Tukey test were used, with p ≤ 0.05. Panavia F when used without catalyst and cured using the LED or the argon ion laser showed degree of conversion values significantly lower than RelyX ARC, with and without catalyst, and cured with any of the light sources. Therefore, the degree of conversion of Panavia F with ED Primer cured with the quartz-tungsten-halogen light was significantly different from that of RelyX ARC regardless of the use of the chemical catalyst and light curing source. In conclusion, RelyX ARC can be cured satisfactorily with the argon ion laser, LED or quartz-tungsten-halogen light with or without a chemical catalyst. To obtain a satisfactory degree of conversion, Panavia F luting cement should be used with ED Primer and cured with halogen light.

  13. Down-conversion photoluminescence sensitizing plasmonic silver nanoparticles on ZnO nanorods to generate hydrogen by water splitting photochemistry

    Energy Technology Data Exchange (ETDEWEB)

    Kung, Po-Yen; Huang, Li-Wen; Shen, Tin-Wei; Wang, Wen-Lin; Su, Yen-Hsun [Department of Materials Science and Engineering, National Cheng Kung University, Tainan, Taiwan (China); Lin, Melody I. [Department of Physics, University of California, Berkeley, California, 94720 (United States)

    2015-01-12

    Silver nanoparticles fabricated onto the surface of the ZnO nanorods form the photoanode and generate photoelectric current due to surface plasmon resonance, which serves as anode electrodes in photoelectrochemical hydrogen production. In order to increase the absorption spectrum of photoanode, organic pigments were utilized as photo-sensitizers to generate down-conversion photoluminescence to excite surface plasmon resonances of silver nanoparticles. The way of using light to carry the energy in electronic scattering regime runs the system for the enhancement of solar water splitting efficiency. It was significantly tuned in environmentally sustainable applications for power generation and development of alternative energy.

  14. Light scattering by particles in water theoretical and experimental foundations

    CERN Document Server

    Jonasz, Miroslaw

    2007-01-01

    Light scattering-based methods are used to characterize small particles suspended in water in a wide range of disciplines ranging from oceanography, through medicine, to industry. The scope and accuracy of these methods steadily increases with the progress in light scattering research. This book focuses on the theoretical and experimental foundations of the study and modeling of light scattering by particles in water and critically evaluates the key constraints of light scattering models. It begins with a brief review of the relevant theoretical fundamentals of the interaction of light with condensed matter, followed by an extended discussion of the basic optical properties of pure water and seawater and the physical principles that explain them. The book continues with a discussion of key optical features of the pure water/seawater and the most common components of natural waters. In order to clarify and put in focus some of the basic physical principles and most important features of the experimental data o...

  15. Degree of conversion of a resin cement light-cured through ceramic veneers of different thicknesses and types.

    Science.gov (United States)

    Runnacles, Patrício; Correr, Gisele Maria; Baratto Filho, Flares; Gonzaga, Carla Castiglia; Furuse, Adilson Yoshio

    2014-01-01

    During the cementation of ceramic veneers the polymerization of resin cements may be jeopardized if the ceramics attenuate the irradiance of the light-curing device. The aim of this study was to evaluate the effect of different types and thicknesses of ceramic veneers on the degree of conversion of a light-cured resin-based cement (RelyX Veneer). The cement was light-cured after interposing ceramic veneers [IPS InLine, IPS Empress Esthetic, IPS e.max LT (low translucency) and IPS e.max HT (high translucency) - Ivoclar Vivadent] of four thicknesses (0.5 mm, 1.0 mm, 1.5 mm and 2.0 mm). As control, the cement was light-cured without interposition of ceramics. The degree of conversion was evaluated by FTIR spectroscopy (n=5). Data were analyzed with one-way ANOVA and Tukey's test (α=0.05). Significant differences were observed among groups (p0.05). Among 1.5-mm-thick veneers, IPS e.max LT was the only one that showed different results from the control (pveneers were able to produce cements with degrees of conversion similar to the control (p>0.05). The degree of conversion of the evaluated light-cured resin cement depends on the thickness and type of ceramics employed when veneers thicker than 1.5 mm are cemented.

  16. Influence of Molecular Oxygen on Ortho-Para Conversion of Water Molecules

    Science.gov (United States)

    Valiev, R. R.; Minaev, B. F.

    2017-07-01

    The mechanism of influence of molecular oxygen on the probability of ortho-para conversion of water molecules and its relation to water magnetization are considered within the framework of the concept of paramagnetic spin catalysis. Matrix elements of the hyperfine ortho-para interaction via the Fermi contact mechanism are calculated, as well as the Maliken spin densities on water protons in H2O and O2 collisional complexes. The mechanism of penetration of the electron spin density into the water molecule due to partial spin transfer from paramagnetic oxygen is considered. The probability of ortho-para conversion of the water molecules is estimated by the quantum chemistry methods. The results obtained show that effective ortho-para conversion of the water molecules is possible during the existence of water-oxygen dimers. An external magnetic field affects the ortho-para conversion rate given that the wave functions of nuclear spin sublevels of the water protons are mixed in the complex with oxygen.

  17. Technologies for Upgrading Light Water Reactor Outlet Temperature

    Energy Technology Data Exchange (ETDEWEB)

    Daniel S. Wendt; Piyush Sabharwall; Vivek Utgikar

    2013-07-01

    Nuclear energy could potentially be utilized in hybrid energy systems to produce synthetic fuels and feedstocks from indigenous carbon sources such as coal and biomass. First generation nuclear hybrid energy system (NHES) technology will most likely be based on conventional light water reactors (LWRs). However, these LWRs provide thermal energy at temperatures of approximately 300°C, while the desired temperatures for many chemical processes are much higher. In order to realize the benefits of nuclear hybrid energy systems with the current LWR reactor fleets, selection and development of a complimentary temperature upgrading technology is necessary. This paper provides an initial assessment of technologies that may be well suited toward LWR outlet temperature upgrading for powering elevated temperature industrial and chemical processes during periods of off-peak power demand. Chemical heat transformers (CHTs) are a technology with the potential to meet LWR temperature upgrading requirements for NHESs. CHTs utilize chemical heat of reaction to change the temperature at which selected heat sources supply or consume thermal energy. CHTs could directly utilize LWR heat output without intermediate mechanical or electrical power conversion operations and the associated thermodynamic losses. CHT thermal characteristics are determined by selection of the chemical working pair and operating conditions. This paper discusses the chemical working pairs applicable to LWR outlet temperature upgrading and the CHT operating conditions required for providing process heat in NHES applications.

  18. Open inlet conversion: Water quality benefits of two designs

    Science.gov (United States)

    Open surface inlets that connect to subsurface tile drainage systems provide a direct pathway for movement of sediment, nutrients, and agrochemicals to surface waters. This study was conducted to determine the reduction in drainage effluent total suspended sediment (TSS) and phosphorus (P) concentr...

  19. Impact of Pilot Light Modeling on the Predicted Annual Performance of Residential Gas Water Heaters: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Maguire, J.; Burch, J.

    2013-08-01

    Modeling residential water heaters with dynamic simulation models can provide accurate estimates of their annual energy consumption, if the units? characteristics and use conditions are known. Most gas storage water heaters (GSWHs) include a standing pilot light. It is generally assumed that the pilot light energy will help make up standby losses and have no impact on the predicted annual energy consumption. However, that is not always the case. The gas input rate and conversion efficiency of a pilot light for a GSWH were determined from laboratory data. The data were used in simulations of a typical GSWH with and without a pilot light, for two cases: 1) the GSWH is used alone; and 2) the GSWH is the second tank in a solar water heating (SWH) system. The sensitivity of wasted pilot light energy to annual hot water use, climate, and installation location was examined. The GSWH used alone in unconditioned space in a hot climate had a slight increase in energy consumption. The GSWH with a pilot light used as a backup to an SWH used up to 80% more auxiliary energy than one without in hot, sunny locations, from increased tank losses.

  20. Light Water Reactor Sustainability Accomplishments Report

    Energy Technology Data Exchange (ETDEWEB)

    McCarthy, Kathryn A. [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2015-02-01

    Welcome to the 2014 Light Water Reactor Sustainability (LWRS) Program Accomplishments Report, covering research and development highlights from 2014. The LWRS Program is a U.S. Department of Energy research and development program to inform and support the long-term operation of our nation’s commercial nuclear power plants. The research uses the unique facilities and capabilities at the Department of Energy national laboratories in collaboration with industry, academia, and international partners. Extending the operating lifetimes of current plants is essential to supporting our nation’s base load energy infrastructure, as well as reaching the Administration’s goal of reducing greenhouse gas emissions to 80% below 1990 levels by the year 2050. The purpose of the LWRS Program is to provide technical results for plant owners to make informed decisions on long-term operation and subsequent license renewal, reducing the uncertainty, and therefore the risk, associated with those decisions. In January 2013, 104 nuclear power plants operated in 31 states. However, since then, five plants have been shut down (several due to economic reasons), with additional shutdowns under consideration. The LWRS Program aims to minimize the number of plants that are shut down, with R&D that supports long-term operation both directly (via data that is needed for subsequent license renewal), as well indirectly (with models and technology that provide economic benefits). The LWRS Program continues to work closely with the Electric Power Research Institute (EPRI) to ensure that the body of information needed to support SLR decisions and actions is available in a timely manner. This report covers selected highlights from the three research pathways in the LWRS Program: Materials Aging and Degradation, Risk-Informed Safety Margin Characterization, and Advanced Instrumentation, Information, and Control Systems Technologies, as well as a look-ahead at planned activities for 2015. If you

  1. Water Uptake Vs. Density and Conversion in Silicon Containing Cyanate Esters (Briefing Charts)

    Science.gov (United States)

    2014-12-17

    Conversion in Silicon Containing Cyanate Esters 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d. PROJECT NUMBER Michael D. Ford...decline in density was found to be similar in magnitude to that of other cyanate ester resins which have been previously studied. The water uptake...followed similar trends as compared to other cyanate esters in that it was similarly dependent on conversion, but did not correlate with the development of

  2. Frequency down-conversion of 637 nm light to the telecommunication band for non-classical light emitted from NV centers in diamond.

    Science.gov (United States)

    Ikuta, Rikizo; Kobayashi, Toshiki; Yasui, Shuto; Miki, Shigehito; Yamashita, Taro; Terai, Hirotaka; Fujiwara, Mikio; Yamamoto, Takashi; Koashi, Masato; Sasaki, Masahide; Wang, Zhen; Imoto, Nobuyuki

    2014-05-05

    We demonstrate a low-noise frequency down-conversion of photons at 637 nm to the telecommunication band at 1587 nm by the difference frequency generation in a periodically-poled lithium niobate. An internal conversion efficiency of the converter is estimated to be 0.44 at the maximum which is achieved by a pump power of 0.43 W, whereas a rate of internal background photons caused by the strong cw pump laser is estimated to be 9 kHz/mW within a bandwidth of about 1 nm. By using the experimental values related to the intrinsic property of the converter, and using the intensity correlation and the average photon number of a 637 nm input light pulse, we derive the intensity correlation of a converted telecom light pulse. Then we discuss feasibility of a single-photon frequency conversion to the telecommunication band for a long-distance quantum communication based on NV centers in diamond.

  3. Modeling Water Clarity and Light Quality in Oceans

    Science.gov (United States)

    Phytoplankton is a primary producer of organic compounds, and it forms the base of the food chain in ocean waters. The concentration of phytoplankton in the water column controls water clarity and the amount and quality of light that penetrates through it. The availability of ade...

  4. Biomass conversions in subcritical and supercritical water: driving force, phase equilibria, and thermodynamic analysis

    Energy Technology Data Exchange (ETDEWEB)

    Feng, W.; Kooi, H.J. van der; Swaan Arons, J. de [Physical Chemistry and Molecular Thermodynamics, Delft University of Technology, Delft (Netherlands)

    2004-07-01

    Two biomass conversion processes have been studied: hydrothermal upgrading (HTU) under subcritical water conditions; supercritical water gasification (SCWG) in supercritical water. For the design of the two biomass conversion processes, the following contributions of thermodynamics have been presented: phase behaviour and phase equilibria in the reactor and separators; indication of the favourable operation conditions and the trends in product distribution for the conversion reactions; construction of heat exchange network and exergy analysis. A wide variety of fluids have been dealt with, from small molecules to large molecules, including non-polar and polar substances. The statistical association fluids theory (SAFT) equation of state has been applied to calculate the mass distribution in different phases and to estimate the entropy and enthalpy values for different mass streams. (author)

  5. Water-related environmental control requirements at municipal solid waste-to-energy conversion facilities

    Energy Technology Data Exchange (ETDEWEB)

    Young, J C; Johnson, L D

    1980-09-01

    Water use and waste water production, water pollution control technology requirements, and water-related limitations to their design and commercialization are identified at municipal solid waste-to-energy conversion systems. In Part I, a summary of conclusions and recommendations provides concise statements of findings relative to water management and waste water treatment of each of four municipal solid waste-to-energy conversion categories investigated. These include: mass burning, with direct production of steam for use as a supplemental energy source; mechanical processing to produce a refuse-derived fuel (RDF) for co-firing in gas, coal or oil-fired power plants; pyrolysis for production of a burnable oil or gas; and biological conversion of organic wastes to methane. Part II contains a brief description of each waste-to-energy facility visited during the subject survey showing points of water use and wastewater production. One or more facilities of each type were selected for sampling of waste waters and follow-up tests to determine requirements for water-related environmental controls. A comprehensive summary of the results are presented. (MCW)

  6. Effect of different photo-initiators and light curing units on degree of conversion of composites

    Directory of Open Access Journals (Sweden)

    William Cunha Brandt

    2010-09-01

    Full Text Available The aim of this study was to evaluate: (i the absorption of photo-initiators and emission spectra of light curing units (LCUs; and (ii the degree of conversion (DC of experimental composites formulated with different photo-initiators when activated by different LCUs. Blends of BisGMA, UDMA, BisEMA and TEGDMA with camphorquinone (CQ and/ or 1-phenyl-1,2-propanedione (PPD were prepared. Dimethylaminoethyl methacrylate (DMAEMA was used as co-initiator. Each mixture was loaded with 65 wt% of silanated filler particles. One quartz-tungsten-halogen - QTH (XL 2500, 3M/ESPE and two lightemitting diode (LED LCUs (UltraBlue IS, DMC and UltraLume LED 5, Ultradent were used for activation procedures. Irradiance (mW/cm² was calculated by the ratio of the output power by the area of the tip, and spectral distribution with a spectrometer (USB 2000. The absorption curve of each photo-initiator was determined using a spectrophotometer (Varian Cary 5G. DC was assessed by Fourier transformed infrared spectroscopy. Data were submitted to two-way ANOVA and Tukey's test (5%. No significant difference was found for DC values when using LED LCUs regardless of the photo-initiator type. However, PPD showed significantly lower DC values than composites with CQ when irradiated with QTH. PPD produced DC values similar to those of CQ, but it was dependent on the LCU type.

  7. Carbon materials as additives to WO3 for an enhanced conversion of simulated solar light

    Directory of Open Access Journals (Sweden)

    Rocío Jiménez Carmona

    2016-02-01

    Full Text Available We have explored the impact of the incorporation of nanoporous carbons as additives to tungsten oxide on the photocatalytic degradation of two recalcitrant pollutants: rhodamine B and phenol, under simulated solar light. For this purpose, WO3/carbon mixtures were prepared using three carbon materials with different properties (in terms of porosity, structural order and surface chemistry. Despite the low carbon content used (2 wt. %, a significant increase in the photocatalytic performance of the semiconductor was observed for all the catalysts. Moreover, the influence of the carbon additive on the performance of the photocatalysts was found to be very different for the two pollutants. Carbon additives of hydrophobic nature increased the photodegradation yield of phenol compared to bare WO3, likely due to the higher affinity and stronger interactions of phenol molecules towards basic nanoporous carbons. Oppositely, the use of acidic carbon additives led to higher rhodamine B conversions due to increased acidity of the WO3/carbon mixtures and the stronger affinity of the pollutant for acidic catalyst’s surfaces. As a result, the photooxidation of rhodamine B is favored by means of a coupled (photosensitized and photocatalytic degradation mechanism. All these results highlight the importance of favoring the interactions of the pollutant with the catalyst’s surface through a detailed design of the features of the photocatalyst.

  8. Catalytic conversion of light alkanes, Phase 3. Topical report, January 1990--December 1992

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1992-12-31

    The mission of this work is to devise a new catalyst which can be used in the first simple, economic process to convert the light alkanes in natural gas to an alcohol-rich oxygenated product which can either be used as an environmentally friendly, high-performance liquid fuel, or a precursor to a liquid hydrocarbon transportation fuel. The authors have entered the proof-of-concept stage for converting isobutane to tert butyl alcohol in a practical process and are preparing to enter proof-of-concept of a propane to isopropyl alcohol process in the near future. Methane and ethane are more refractory and thus more difficult to oxidize than the C{sub 3} and C{sub 4} hydrocarbons. Nonetheless, advances made in this area indicate that further research progress could achieve the goal of their direct conversion to alcohols. Progress in Phase 3 catalytic vapor phase methane and ethane oxidation over metals in regular oxidic lattices are the subject of this topical report.

  9. Degree of Conversion of a Resin Cement Light-Cured Through Ceramic Veneers of Different Thicknesses and Types

    OpenAIRE

    Runnacles,Patrício; Correr, Gisele Maria; Flares BARATTO FILHO; Gonzaga, Carla Castiglia; Furuse, Adilson Yoshio

    2014-01-01

    During the cementation of ceramic veneers the polymerization of resin cements may be jeopardized if the ceramics attenuate the irradiance of the light-curing device. The aim of this study was to evaluate the effect of different types and thicknesses of ceramic veneers on the degree of conversion of a light-cured resin-based cement (RelyX Veneer). The cement was light-cured after interposing ceramic veneers [IPS InLine, IPS Empress Esthetic, IPS e.max LT (low translucency) and IPS e.max HT (hi...

  10. A new method to create depth information based on lighting analysis for 2D/3D conversion

    Institute of Scientific and Technical Information of China (English)

    Hyunho; Han; Gangseong; Lee; Jongyong; Lee; Jinsoo; Kim; Sanghun; Lee

    2013-01-01

    A new method creating depth information for 2D/3D conversion was proposed. The distance between objects is determined by the distances between objects and light source position which is estimated by the analysis of the image. The estimated lighting value is used to normalize the image. A threshold value is determined by some weighted operation between the original image and the normalized image. By applying the threshold value to the original image, background area is removed. Depth information of interested area is calculated from the lighting changes. The final 3D images converted with the proposed method are used to verify its effectiveness.

  11. Electrical detection of ortho-para conversion in fullerene-encapsulated water

    Science.gov (United States)

    Meier, Benno; Mamone, Salvatore; Concistrè, Maria; Alonso-Valdesueiro, Javier; Krachmalnicoff, Andrea; Whitby, Richard J.; Levitt, Malcolm H.

    2015-08-01

    Water exists in two spin isomers, ortho and para, that have different nuclear spin states. In bulk water, rapid proton exchange and hindered molecular rotation obscure the direct observation of two spin isomers. The supramolecular endofullerene H2O@C60 provides freely rotating, isolated water molecules even at cryogenic temperatures. Here we show that the bulk dielectric constant of this substance depends on the ortho/para ratio, and changes slowly in time after a sudden temperature jump, due to nuclear spin conversion. The attribution of the effect to ortho-para conversion is validated by comparison with nuclear magnetic resonance and quantum theory. The change in dielectric constant is consistent with an electric dipole moment of 0.51+/-0.05 Debye for an encapsulated water molecule, indicating the partial shielding of the water dipole by the encapsulating cage. The dependence of bulk dielectric constant on nuclear spin isomer composition appears to be a previously unreported physical phenomenon.

  12. Predicting spectral and PAR light attenuation in Greenlandic coastal waters

    DEFF Research Database (Denmark)

    Murray, Ciarán; Markager, Stiig; Stedmon, Colin

    The spectral quality and penetration of light are key parameters controlling the productivity of Greenlandic fjords. Solar elevation and sea ice play an important role, but during the increasing ice free period and summer months in particular, light is also regulated by water constituents. We pre...

  13. Predicting Spectral and PAR Light Attenuation in Greenlandic Coastal Waters

    DEFF Research Database (Denmark)

    Murray, Ciarán; Stedmon, Colin A.; Markager, Stiig

    The spectral quality and penetration of light are key parameters controlling the productivity of Greenlandic fjords. Solar elevation and sea ice play an important role, but during the increasing ice free period and summer months in particular, light is also regulated by water constituents. We pre...

  14. Modeling Water Clarity and Light Quality in Oceans

    Directory of Open Access Journals (Sweden)

    Mohamed A. Abdelrhman

    2016-11-01

    Full Text Available Phytoplankton is a primary producer of organic compounds, and it forms the base of the food chain in ocean waters. The concentration of phytoplankton in the water column controls water clarity and the amount and quality of light that penetrates through it. The availability of adequate light intensity is a major factor in the health of algae and phytoplankton. There is a strong negative coupling between light intensity and phytoplankton concentration (e.g., through self-shading by the cells, which reduces available light and in return affects the growth rate of the cells. Proper modeling of this coupling is essential to understand primary productivity in the oceans. This paper provides the methodology to model light intensity in the water column, which can be included in relevant water quality models. The methodology implements relationships from bio-optical models, which use phytoplankton chlorophyll a (chl-a concentration as a surrogate for light attenuation, including absorption and scattering by other attenuators. The presented mathematical methodology estimates the reduction in light intensity due to absorption by pure seawater, chl-a pigment, non-algae particles (NAPs and colored dissolved organic matter (CDOM, as well as backscattering by pure seawater, phytoplankton particles and NAPs. The methods presented facilitate the prediction of the effects of various environmental and management scenarios (e.g., global warming, altered precipitation patterns, greenhouse gases on the wellbeing of phytoplankton communities in the oceans as temperature-driven chl-a changes take place.

  15. Conversion of water towers – an instrument for conserving heritage assets

    Directory of Open Access Journals (Sweden)

    Andreea-Loreta Cercleux

    2014-06-01

    Full Text Available Water towers are symbolical landmarks that refer to the industrialization. The oldest water towers are technical and industrial assets whose current and future evolution is a sensitive matter as a result of the economic context that brought about the closing of numerous industrial enterprises and abandoning infrastructure assets, including water towers. Some water towers were included on the national cultural-heritage lists across the world, thanks to the manifold values they incorporate (technological, historical, architectural, esthetical, among others. In this context, it has become necessary to convert them, with the twofold purpose of conserving them and assigning them a new function, for the local community members. Although there are numerous models for good practice in the conversion of water towers in several European countries, in Romania their reuse is a difficult process, most of the time burdened by shortcomings of legislation or lack of financial support. The study’s main purpose is to present reasons for the conversion of water towers and to highlight several good practice models, as well as to present several water towers with a high potential for conversion.

  16. Nuclear spin conversion of water inside fullerene cages detected by low-temperature nuclear magnetic resonance

    Energy Technology Data Exchange (ETDEWEB)

    Mamone, Salvatore, E-mail: s.mamone@soton.ac.uk; Concistrè, Maria; Carignani, Elisa; Meier, Benno; Krachmalnicoff, Andrea; Johannessen, Ole G.; Denning, Mark; Carravetta, Marina; Whitby, Richard J.; Levitt, Malcolm H., E-mail: mhl@soton.ac.uk [School of Chemistry, University of Southampton, Southampton SO17 1BJ (United Kingdom); Lei, Xuegong; Li, Yongjun [Department of Chemistry, Columbia University, New York, New York 10027 (United States); Goh, Kelvin; Horsewill, Anthony J. [School of Physics and Astronomy, University of Nottingham, Nottingham NG7 2RD (United Kingdom)

    2014-05-21

    The water-endofullerene H{sub 2}O@C{sub 60} provides a unique chemical system in which freely rotating water molecules are confined inside homogeneous and symmetrical carbon cages. The spin conversion between the ortho and para species of the endohedral H{sub 2}O was studied in the solid phase by low-temperature nuclear magnetic resonance. The experimental data are consistent with a second-order kinetics, indicating a bimolecular spin conversion process. Numerical simulations suggest the simultaneous presence of a spin diffusion process allowing neighbouring ortho and para molecules to exchange their angular momenta. Cross-polarization experiments found no evidence that the spin conversion of the endohedral H{sub 2}O molecules is catalysed by {sup 13}C nuclei present in the cages.

  17. Recyclable Magnetite Nanoparticle Catalyst for One-Pot Conversion of Cellobiose to 5-Hydroxymethylfurfural in Water

    Directory of Open Access Journals (Sweden)

    Anuja Bhalkikar

    2015-01-01

    Full Text Available Environmentally benign and easily recoverable magnetite nanoparticles (Fe3O4 NPs were demonstrated to catalyze the one-pot conversion of cellobiose, a glucose disaccharide, to 5-hydroxymethylfurfural (5-HMF. The conversion was achieved in water under hydrothermal conditions. The catalytic activity of Fe3O4 NPs surpassed those of iron (II and iron (III chlorides in this reaction. Optimized cellobiose conversion reactions catalyzed with Fe3O4 NPs gave the highest 5-HMF yields of 23.4 ± 0.6% at 160°C for 24 hours. After three reuses, the Fe3O4 NP catalyst retained its catalytic activity with similar 5-HMF yields, demonstrating the recyclability of this eco-friendly catalyst in water.

  18. Water dimer absorption of visible light

    Directory of Open Access Journals (Sweden)

    J. Hargrove

    2007-07-01

    Full Text Available Laboratory measurements of water vapor absorption using cavity ring-down spectroscopy revealed a broad absorption at 405 nm with a quadratic dependence on water monomer concentration, a similar absorption with a linear component at 532 nm, and only linear absorption at 570 nm in the vicinity of water monomer peaks. D2O absorption is weaker and linear at 405 nm. Van't Hoff plots constructed at 405.26 nm suggest that for dimerization, Keq=0.056±0.02 atm−1, ΔH°301 K=−16.6±2 kJ mol−1 and ΔS°301 K=−80±10 J mol−1 K−1. This transition peaks at 409.5 nm, could be attributed to the 8th overtone of water dimer and the 532 nm absorption to the 6th overtone. It is possible that some lower overtones previously searched for are less enhanced. These absorptions could increase water vapor feed back calculations leading to higher global temperature projections with currently projected greenhouse gas levels or greater cooling from greenhouse gas reductions.

  19. Light-harvesting host-guest antenna materials for solar energy conversion devices

    Science.gov (United States)

    Huber, Stefan; Calzaferri, Gion

    2006-04-01

    In natural photosynthesis, light is absorbed by photonic antenna systems consisting of a few hundred chlorophyll molecules. These devices allow fast energy transfer from an electronically excited molecule to an unexcited neighbour molecule in such a way that the excitation energy reaches the reaction centre with high probability. Trapping occurs there. The anisotropic arrangement of the chlorophyll molecules is important for efficient energy migration. In natural antennae the formation of aggregates is prevented by fencing the chlorophyll molecules in polypeptide cages. A similar approach is possible by enclosing dyes inside a microporous material and by choosing conditions such that the cavities are able to uptake only monomers but not aggregates. In most of our experiments we have been using zeolite L as a host because it was found to be very versatile. Its crystals are of cylindrical shape and consist of an extended one-dimensional tube system. They can be prepared in wide size range. We have filled the individual tubes with successive chains of different dye molecules and we have shown that photonic antenna materials can be prepared. Moreover, fluorescent dye molecules can be bound covalently to the channel entrances. Dependent on the spectral properties of these stopcock molecules, the electronic excitation energy is transported radiationless to the stopcock fixed at the ends of the nanochannels or injected from the stopcock to the dyes inside the zeolite. The radiationless energy migration is in competition with spontaneous emission, thermal deactivation, quenching, and photochemically induced degradation. Fast energy migration is therefore crucial for an efficient antenna material. - The supramolecular organization of the dyes inside the channels is a first stage of organization. It allows light harvesting within the volume of a dye-loaded zeolite L crystal and radiationless transport to both ends of the cylinder or from the ends to the centre. The second

  20. The effect of temperature on the catalytic conversion of Kraft lignin using near-critical water

    DEFF Research Database (Denmark)

    Nguyen, Thi Dieu Huyen; Maschietti, Marco; Åmand, Lars-Erik

    2014-01-01

    The catalytic conversion of suspended LignoBoost Kraft lignin was performed in near-critical water using ZrO2/K2CO3 as the catalytic system and phenol as the co-solvent and char suppressing agent. The reaction temperature was varied from 290 to 370 C and its effect on the process was investigated...

  1. Light induced degradation of testosterone in waters

    Energy Technology Data Exchange (ETDEWEB)

    Vulliet, Emmanuelle, E-mail: e.vulliet@sca.cnrs.fr [Service Central d' Analyse du CNRS - USR59, Chemin du Canal, F-69360 Solaize (France); Falletta, Marine; Marote, Pedro [Laboratoire des Sciences Analytiques - UMR 5180, Universite Claude Bernard, 43 bd du 11 Novembre 1918, F-69622 Villeurbanne Cedex (France); Lomberget, Thierry [Laboratoire de Chimie Therapeutique, Universite de Lyon, Universite Lyon 1, Faculte de Pharmacie-ISPB, EA 4443 Biomolecules, Cancer et Chimioresistances, INSERM U863 Hormones steroides et proteines de liaison, IFR 62, 8 avenue Rockefeller, F-69373, Lyon Cedex 08 (France); Paisse, Jean-Olivier; Grenier-Loustalot, Marie-Florence [Service Central d' Analyse du CNRS - USR59, Chemin du Canal, F-69360 Solaize (France)

    2010-08-01

    The degradation of testosterone under simulated irradiations was studied in phosphate buffers and in natural waters at various excitation wavelengths. The quantum yield of photolysis was significantly lower at 313 nm (2.4 x 10{sup -3}) than at 254 nm (0.225). The formation of several photoproducts was observed, some of them being rapidly transformed in turn while others show higher stability towards subsequent irradiations. The nature of the main products was tentatively identified, both deduced from their spectral and spectrometric data and by comparison with synthesised standard compounds. Among the obtained photoproducts, the main one is possibly a spiro-compound, hydroxylated derivative of testosterone originating from the photohydratation of the enone group. The photodegradation pathway includes also photorearrangements. One of them leads to (1,5,10)-cyclopropyl-17{beta}-hydroxyandrostane-2-one. The pH of the water does not seem to affect the rate of phototransformation and the nature of the by-products.

  2. Polarization of light in shallow waters

    Science.gov (United States)

    Gilerson, Alexander; Ibrahim, Amir; Stepinski, Jan; Ahmed, Samir

    2013-10-01

    Measurements of the upwelling polarized radiance in relatively shallow waters of varying depths and benthic conditions are compared to simulationsrevealing the depolarizing nature of the seafloor. Significant correlations between simulations and measurements are attained when the appropriate unpolarized, Lambertian bottoms are included in the radiative transfer model. The bottoms used in this study produce realistic upwelling radiance distributions as well as ranges of the degree of linear polarization (DoLP) that peak between 10 and 30%. This study specifically finds that polarization in upwelling radiance is best preserved at long wavelengths in clear waters and also at short wavelengths in phytoplankton- and CDOM-rich waters. These results can thus facilitate the detection of benthic materials as well as future studies of camouflage by benthic biota.The DoLPwas found to be highly sensitive to benthic reflectance, but the angle of polarization (AoLP), which quantifies the orientation of polarization, is independent of it. The AoLP could therefore be used to communicate and sense direction underwater.

  3. Influence of increment thickness on light transmission, degree of conversion and micro hardness of bulk fill composites.

    Science.gov (United States)

    Garoushi, Sufyan; Vallittu, Pekka; Shinya, Akikazu; Lassila, Lippo

    2016-09-01

    This study evaluated characteristics of light transmission, degree of monomer conversion and surface microhardness of bulk fill, conventional and fiber-reinforced resin based composites (RBCs) through different incremental thicknesses of resin composite. Working hypotheses was that there are differences in transmission of blue light through RBCs of different kinds and that the thickness of the increments influence the degree of monomer conversion of RBCs. Six bulk fill, three conventional nanohybrid, one short fiber reinforced and one flowable RBCs were evaluated. For each material, four different incremental thicknesses (1, 2, 3 and 4 mm) were considered (n = 5). The specimens were prepared in cylindrical Teflon molds that are open at the top and the bottom sides and cured for 40 s by applying the curing unit. After curing process, the specimens were ground with a silicon carbide paper with a grit size of 1200 and 4000, and then stored dry at 37 °C for 24 h. Light transmission, degree of monomer conversion, surface microhardness were measured and data were analyzed using ANOVA (p = 0.05). There were differences in light transmission of resin composites of various types and brands. Low-viscous bulk fill and short fiber-reinforced RBCs presented higher light transmission compared to resin composites of higher viscosity. Reduced light transmission and lower surface microhardness and DC % at bottom side of the specimen suggests that more attention needs to be paid to ensure proper curing of the resin composite in deep cavities.

  4. Influence of the photoinitiator system and light photoactivation units on the degree of conversion of dental composites

    Directory of Open Access Journals (Sweden)

    Isabel Cristina Celerino de Moraes Porto

    2010-12-01

    Full Text Available The aim of this study was to observe the influence of two light polymerization units (LED or halogen light on the degree of conversion (DC of three dental composites with lighter shades and a different photoinitiator system. The top (T and bottom (B surfaces of 60 discs of composite resin (Filtek™ Supreme, Filtek™ Z250, Tetric™ Ceram Bleach cured either by LED or by halogen lamp (HL were studied using an FT-Raman spectrometer. The degree of conversion (DC was evaluated by following the changes in the intensity of the methacrylate C=C stretching mode at 1640 cm-1. The calculated DC ranged from 54.2% (B to 73.4% (T and from 60.2% (B to 76.6% (T for the LED and HL, respectively. LED and halogen devices were able to produce an adequate DC for all the resins tested.

  5. Efficient conversion from infrared to red light by cascaded nonlinear optical processes using an aperiodically poled lithium niobate crystal

    Directory of Open Access Journals (Sweden)

    Juan Eduardo González

    2015-12-01

    Full Text Available We present a scheme for conversion of pulsed light from the infrared to the red spectral region, using an aperiodically poled ferroelectric crystal within a resonant cavity in which two cascaded nonlinear optical processes occur when pumped with a pulsed Nd:YAG laser. This device emits 9 ns pulses of over 1 mJ at 710 nm and is a viable source for future biomedical applications.

  6. The roadmap for low price- high performance IR detector based on LWIR to NIR light up-conversion approach

    Science.gov (United States)

    Kipper, R.; Arbel, D.; Baskin, E.; Fayer, A.; Epstein, A.; Shuall, N.; Saguy, A.; Veksler, D.; Spektor, B.; Ben-Aharon, D.; Garber, V.

    2009-05-01

    The introduction of an uncooled microbolometer image sensor about a decade ago enabled cost reduction of IR cameras. As a result, the available markets grew both in military and civilian applications. Since then, the price of microbolometer was gradually reduced due to introduction of devices with smaller pixel, maturity of the technology and quantity growth. However, the requirement for a vacuum package still limits the price of microbolometer based cameras to several thousands of dollars. Sirica's novel wavelength conversion technology aims at breaking this paradigm by being uncooled and vacuumless, lowering IR camera prices by an order of magnitude, opening the way to new mass markets. Sirica's proprietary IR-to-Visible/NIR conversion layer allows for low-cost high performance LWIR detector with no requirement for cooling and vacuum packaging. In the last years, the development efforts focused on development of the conversion media. Recently, a parallel effort for the integration of the conversion layer together with other detector components has started. Packaging of detector components, such as conversion layer, pumping light source, dichroic filter, and their coupling with silicon CMOS image sensor have great importance from a price-performance point of view. According to the company's business-development roadmap, the detector prototype should be available during the first quarter of 2010.

  7. Stable quantum dot photoelectrolysis cell for unassisted visible light solar water splitting.

    Science.gov (United States)

    Yang, Hong Bin; Miao, Jianwei; Hung, Sung-Fu; Huo, Fengwei; Chen, Hao Ming; Liu, Bin

    2014-10-28

    Sunlight is an ideal source of energy, and converting sunlight into chemical fuels, mimicking what nature does, has attracted significant attention in the past decade. In terms of solar energy conversion into chemical fuels, solar water splitting for hydrogen production is one of the most attractive renewable energy technologies, and this achievement would satisfy our increasing demand for carbon-neutral sustainable energy. Here, we report corrosion-resistant, nanocomposite photoelectrodes for spontaneous overall solar water splitting, consisting of a CdS quantum dot (QD) modified TiO2 photoanode and a CdSe QD modified NiO photocathode, where cadmium chalcogenide QDs are protected by a ZnS passivation layer and gas evolution cocatalysts. The optimized device exhibited a maximum efficiency of 0.17%, comparable to that of natural photosynthesis with excellent photostability under visible light illumination. Our device shows spontaneous overall water splitting in a nonsacrificial environment under visible light illumination (λ > 400 nm) through mimicking nature's "Z-scheme" process. The results here also provide a conceptual layout to improve the efficiency of solar-to-fuel conversion, which is solely based on facile, scalable solution-phase techniques.

  8. Critical reflections on building a community of conversation about water governance in Australia

    Directory of Open Access Journals (Sweden)

    Naomi Rubenstein

    2016-02-01

    Full Text Available Water governance has emerged as a field of research endeavour in response to failures of current and historical management approaches to adequately address persistent decline in ecological health of many river catchments and pressures on associated communities. Attention to situational framing is a key aspect of emerging approaches to water governance research, including innovations that build capacity and confidence to experiment with approaches capable of transforming situations usefully framed as 'wicked'. Despite international investment in water governance research, a national research agenda on water governance was lacking in Australia in the late 2000s as were mechanisms to build the capacity of interdisciplinary and transdisciplinary research and collaborative policy practice. Through a two-year Water Governance Research Initiative (WGRI, we designed and facilitated the development of a community of conversation between researchers concerned with the dynamics of human-ecological systems from the natural sciences, humanities, social sciences, policy, economics, law and philosophy. The WGRI was designed as a learning system, with the intention that it would provide opportunities for conversations, learning and reflection to emerge. In this paper we outline the starting conditions and design of the WGRI, critically reflect on new narratives that arose from this initiative, and evaluate its effectiveness as a boundary organisation that contributed to knowledge co-production in water governance. Our findings point to the importance of investment in institutions that can act as integrative and facilitative governance mechanisms, to build capacity to work with and between research, policy, local stakeholders and practitioners.

  9. Heavy rare-earth-doped ZBLAN glasses for UV–blue up-conversion and white light generation

    Energy Technology Data Exchange (ETDEWEB)

    Méndez-Ramos, J., E-mail: jmendezr@ull.es [Departamento de Física Fundamental y Experimental, Electrónica y Sistemas, Universidad de La Laguna, 38206 La Laguna, Tenerife (Spain); Acosta-Mora, P. [Departamento de Física Fundamental y Experimental, Electrónica y Sistemas, Universidad de La Laguna, 38206 La Laguna, Tenerife (Spain); Ruiz-Morales, J.C., E-mail: jcruiz@ull.es [Departamento de Química Inorgánica, Universidad de La Laguna, 38206 La Laguna, Tenerife (Spain); Hernández, T.; Borges, M.E. [Departamento de Ingeniería Química, Universidad de La Laguna, 38206 La Laguna, Tenerife (Spain); Esparza, P., E-mail: pesparza@ull.es [Departamento de Química Inorgánica, Universidad de La Laguna, 38206 La Laguna, Tenerife (Spain)

    2013-11-15

    Noticeable UV–vis up-conversion luminescence of Er{sup 3+} and Tm{sup 3+} ions sensitised by Yb{sup 3+} ions in ZrF{sub 4}–BaF{sub 2}–LaF{sub 3}–AlF{sub 3}–NaF (ZBLAN) fluoride glasses have been obtained under near-infrared excitation at 980 nm. Red, green and blue simultaneous emissions were observed yielding to a white-balanced overall colour. Moreover significant UV up-conversion emissions observed can contribute to enhance spectral response of semiconductor electrode, such as TiO{sub 2} and Fe{sub 2}O{sub 3}, for sustainable production of hydrogen via water photolysis by harvesting of long wavelength solar irradiation, emerging as an interesting solely luminescent approach for improving water-splitting. Total infrared to UV–vis up-conversion efficiency has been calculated to be at around 46%. Laboratory tests prove the improvement in the photocatalytic action of a commercial benchmark photocatalyst (TiO{sub 2} Degussa P25) in the decomposition of methylene blue in water under sun-like irradiation, by a factor of 16% driven by up-conversion effects due to the inclusion of RE-doped ZBLAN powders into a slurry-type photo-reactor. -- Highlights: • Successful development of heavy rare-earth doped (Yb{sup 3+}–Tm{sup 3+}–Er{sup 3+}) ZBLAN glasses. • Very efficient red, green and blue simultaneous up-conversion emissions yielding to a white-balanced overall colour. • High intense UV up-conversion emissions to enhance spectral response of semiconductor electrode, such as TiO{sub 2} and Fe{sub 2}O{sub 3} to boost their photo-catalytic action in water-splitting. • Total infrared to UV–vis up-conversion efficiency calculated to be at around 46%. • Enhancement of about 16% of the photocatalytic activity of commercial TiO{sub 2} catalyst.

  10. Toward direct light-to-digital conversion using a pulse-driven hybrid MOS-PN photodetector.

    Science.gov (United States)

    Sallin, Denis; Koukab, Adil; Kayal, Maher

    2015-02-15

    In this Letter, a direct light-to-digital converter based on an MOS-PN photodetector driven by pulsed voltage is presented. The objective is to avoid any analog-to-digital or time-to-digital conversion and, thereby, to pave the way for a new generation of fully digital imaging sensors with reduced complexity, area, and power consumption. Moreover, the pulsed voltage operation allows for a significant reduction of the dark level. The concept is validated by a theoretical study and TCAD simulations. A first prototype fabricated in 0.18 μm CMOS technology is presented. The experimental results under various light conditions show that the pulsed voltage improves the light sensitivity by several orders of magnitude.

  11. Conversion of orbital angular momentum of light in chiral fiber gratings.

    Science.gov (United States)

    Xu, Huaxing; Yang, Li

    2013-06-01

    We examine mode couplings in chiral fiber grating (CFG) with N-fold rotation symmetry in the cross section and show how the angular momentum matching condition in couplings determines the generation and conversion of orbital angular momentum (OAM) beams. Then we discuss interactions of OAM and spin angular momentum in single- and double-helix long-period CFGs excited by the fundamental core modes. Subsequently, taking right-handed elliptic-core long-period CFGs as example, we demonstrate a dual-OAM converter generating OAM beams with charge +2 and charge +4 at dual wavelengths, both with a conversion efficiency greater than 97%, as well as a broadband converter based on adiabatic coupling, with a bandwidth about 10 nm for a conversion efficiency greater than 95%.

  12. Mutual conversion and asymmetric transmission of linearly polarized light in bilayered chiral metamaterial.

    Science.gov (United States)

    Xu, Yiqun; Shi, Quanchao; Zhu, Zheng; Shi, Jinhui

    2014-10-20

    We propose a kind of planar chiral optical metamaterial consisting of two layers of connected I-shape resonators arranged by a twist angle of 90°. Numerical simulation results demonstrate that our scheme can realize a mutual polarization conversion and dual-band asymmetric transmission for linearly polarized waves in the optical regime. For the forward propagation, the x-to-y and y-to-x polarization conversions in the proposed bilayered metamaterial result from the concentric and eccentric C-shaped dimers, respectively. The current distributions of bilayered metamaterials at the resonant frequencies are presented to interpret the dual-band asymmetric transmission. The polarization conversion efficiency and resonant frequencies can be modified via parametric study.

  13. Highly photoluminescent and photostable CdSe quantum dot-nylon hybrid composites for efficient light conversion applications

    Energy Technology Data Exchange (ETDEWEB)

    Yuan Ying; Riehle, Frank-Stefan [Freiburg Materials Research Centre (FMF), University of Freiburg, Stefan-Meier-Str. 21, D-79104 Freiburg (Germany); Department of Microsystems Engineering (IMTEK), Georg Koehler Allee 103, University of Freiburg, D-79110 Freiburg (Germany); Nitschke, Roland [Life Imaging Center, Centre of Systems Biology, University of Freiburg Habsburgerstr. 49, D-79104 Freiburg (Germany); Centre for Biological Signalling Studies (BIOSS), University of Freiburg (Germany); Krueger, Michael, E-mail: michael.krueger@fmf.uni-freiburg.de [Freiburg Materials Research Centre (FMF), University of Freiburg, Stefan-Meier-Str. 21, D-79104 Freiburg (Germany); Department of Microsystems Engineering (IMTEK), Georg Koehler Allee 103, University of Freiburg, D-79110 Freiburg (Germany)

    2012-02-15

    Highlights: Black-Right-Pointing-Pointer A novel in situ synthesis approach for highly luminescent CdSe core QDs-nylon hybrid materials. Black-Right-Pointing-Pointer Potential applications for light and energy conversion are demonstrated. Black-Right-Pointing-Pointer Three dimensional structures out of this hybrid material are available. - Abstract: Highly photoluminescent hexadecylamine (HDA) capped core CdSe quantum dots (QDs) with fluorescent quantum yields (QYs) up to 60% were synthesized using a hot injection method and directly incorporated into nylon polymer. For the incorporation of crude CdSe QDs into nylon a simple reproducible and upscalable one pot approach was developed without the need of further purification steps. The photoluminescence (PL) properties of the core QDs and the resulting QD-polymer hybrid composites were investigated and compared. Red emitting hybrid materials exhibit a QY of 60% with a high potential for applications in direct light and energy conversion. The hybrid materials could be successfully utilized as LED conversion layers. By avoiding exposure to oxygen the hybrid films can be kept for a month without detecting a significant decrease in luminescence. Various three dimensional structures are easily available opening doors for further applications such as novel materials for fluorescence standard development in laser scanning microscopy (LSM).

  14. Multi-functional electrospun nanofibres for advances in tissue regeneration, energy conversion & storage, and water treatment.

    Science.gov (United States)

    Peng, Shengjie; Jin, Guorui; Li, Linlin; Li, Kai; Srinivasan, Madhavi; Ramakrishna, Seeram; Chen, Jun

    2016-03-07

    Tissue regeneration, energy conversion & storage, and water treatment are some of the most critical challenges facing humanity in the 21st century. In order to address such challenges, one-dimensional (1D) materials are projected to play a key role in developing emerging solutions for the increasingly complex problems. Eletrospinning technology has been demonstrated to be a simple, versatile, and cost-effective method in fabricating a rich variety of materials with 1D nanostructures. These include polymers, composites, and inorganic materials with unique chemical and physical properties. In this tutorial review, we first give a brief introduction to electrospun materials with a special emphasis on the design, fabrication, and modification of 1D functional materials. Adopting the perspective of chemists and materials scientists, we then focus on the recent significant progress made in the domains of tissue regeneration (e.g., skin, nerve, heart and bone) and conversion & storage of clean energy (e.g., solar cells, fuel cells, batteries, and supercapacitors), where nanofibres have been used as active nanomaterials. Furthermore, this review's scope also includes the advances in the use of electrospun materials for the removal of heavy metal ions, organic pollutants, gas and bacteria in water treatment applications. Finally a conclusion and perspective is provided, in which we discuss the remaining challenges for 1D electrospun nanomaterials in tissue regeneration, energy conversion & storage, and water treatment.

  15. Electrical detection of ortho–para conversion in fullerene-encapsulated water

    Science.gov (United States)

    Meier, Benno; Mamone, Salvatore; Concistrè, Maria; Alonso-Valdesueiro, Javier; Krachmalnicoff, Andrea; Whitby, Richard J.; Levitt, Malcolm H.

    2015-01-01

    Water exists in two spin isomers, ortho and para, that have different nuclear spin states. In bulk water, rapid proton exchange and hindered molecular rotation obscure the direct observation of two spin isomers. The supramolecular endofullerene H2O@C60 provides freely rotating, isolated water molecules even at cryogenic temperatures. Here we show that the bulk dielectric constant of this substance depends on the ortho/para ratio, and changes slowly in time after a sudden temperature jump, due to nuclear spin conversion. The attribution of the effect to ortho–para conversion is validated by comparison with nuclear magnetic resonance and quantum theory. The change in dielectric constant is consistent with an electric dipole moment of 0.51±0.05 Debye for an encapsulated water molecule, indicating the partial shielding of the water dipole by the encapsulating cage. The dependence of bulk dielectric constant on nuclear spin isomer composition appears to be a previously unreported physical phenomenon. PMID:26299447

  16. Patterns and properties of polarized light in air and water.

    Science.gov (United States)

    Cronin, Thomas W; Marshall, Justin

    2011-03-12

    Natural sources of light are at best weakly polarized, but polarization of light is common in natural scenes in the atmosphere, on the surface of the Earth, and underwater. We review the current state of knowledge concerning how polarization and polarization patterns are formed in nature, emphasizing linearly polarized light. Scattering of sunlight or moonlight in the sky often forms a strongly polarized, stable and predictable pattern used by many animals for orientation and navigation throughout the day, at twilight, and on moonlit nights. By contrast, polarization of light in water, while visible in most directions of view, is generally much weaker. In air, the surfaces of natural objects often reflect partially polarized light, but such reflections are rarer underwater, and multiple-path scattering degrades such polarization within metres. Because polarization in both air and water is produced by scattering, visibility through such media can be enhanced using straightforward polarization-based methods of image recovery, and some living visual systems may use similar methods to improve vision in haze or underwater. Although circularly polarized light is rare in nature, it is produced by the surfaces of some animals, where it may be used in specialized systems of communication.

  17. Deep water pipe, pump, and mooring study: Ocean Thermal Energy Conversion program. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Little, T.E.; Marks, J.D.; Wellman, K.H.

    1976-06-01

    The ocean engineering issues affecting the design, construction, deployment, and operation of Ocean Thermal Energy Conversion (OTEC) power plants are of key importance. This study addressed the problems associated with the conceptual design of the deep-water pipe, cold-water-pumping, and platform mooring arrangements. These subsystems fall into a natural grouping since the parameters affecting their design are closely related to each other and to the ocean environment. Analysis and evaluations are provided with a view toward judging the impact of the various subsystems on the overall plant concept and to provide an estimate of material and construction cost. Parametric data is provided that describes mooring line configurations, mooring line loads, cold water pipe configurations, and cold water pumping schemes. Selected parameters, issues, and evaluation criteria are used to judge the merits of candidate concepts over a range of OTEC plant size from 100 MWe to 1000 MWe net output power.

  18. Investing in Their Future: Portland’s Purchase and Conversion of an LED Street Lighting System

    Energy Technology Data Exchange (ETDEWEB)

    Kinzey, B. R. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Rosinbum, T. [Portland Bureau of Transportation, Portland, OR (United States)

    2015-08-28

    During the ongoing process of converting its streetlights from high-pressure sodium to LED, the city of Portland, Oregon, purchased a large portion of its street lighting system and encountered a range of issues among the stakeholders. This report identifies some of the challenges involved and discusses how they were addressed, in order to help inform and facilitate future lighting transitions elsewhere.

  19. I. Evaluation of the impact of alternative light technology on male broiler chicken growth, feed conversion, and allometric characteristics.

    Science.gov (United States)

    Rogers, Allison G; Pritchett, Elizabeth M; Alphin, Robert L; Brannick, Erin M; Benson, Eric R

    2015-03-01

    This study evaluates the impact of light-emitting diode (LED), cold cathode fluorescent (CCFL), and incandescent lamps on broiler performance. Male Ross 708 broilers (n=672) were raised to 6 wk age in 8 black-out modified large colony houses, under identical intermittent lighting conditions using 4 unique types of lamps, which were gradually dimmed throughout the study. Incandescent lamps served as the control; experimental technologies tested included CCFL and 2 different LED lamps. Each technology was tested in duplicate for each of 4 trials (8 replications total per technology) conducted across the course of one year to account for seasonal variance. Live performance for each technology was evaluated using live broiler body weight (BW), weight gain, feed conversion, and mortality. Birds were removed from each house at 7, 14, 35, and 42 d to be humanely euthanized, weighed, and necropsied for allometric tissue sample analysis. Relative to the technologies tested, results indicate that birds raised under incandescent lamps had significantly higher BW by 42 d, compared to birds raised under CCFL lamps, which had poorer BW performance (P=0.03). Birds raised under both LED technologies grew to final BWs similar to those raised under incandescent light, with significant differences in neither feed conversion nor mortality.

  20. Light alkane conversion processes - Suprabiotic catalyst systems for selective oxidation of light alkane gases to fuel oxygenates

    Energy Technology Data Exchange (ETDEWEB)

    Lyons, J.E.

    1992-01-01

    The objective of the work presented in this paper is to develop new, efficient catalysts for the selective transformation of the light alkanes in natural gas to alcohols for use as liquid transportation fuels, fuel precursors and chemical products. There currently exists no DIRECT one-step catalytic air-oxidation process to convert these substrates to alcohols. Such a one-step route would represent superior useful technology for the utilization of natural gas and similar refinery-derived light hydrocarbon streams. Processes for converting natural gas or its components (methane, ethane, propane, and the butanes) to alcohols for use as motor fuels, fuel additives or fuel precursors will not only add a valuable alternative to crude oil but will produce a clean-burning, high octane alternative to conventional gasoline.

  1. Light alkane conversion processes - Suprabiotic catalyst systems for selective oxidation of light alkane gases to fuel oxygenates.

    Energy Technology Data Exchange (ETDEWEB)

    Lyons, J.E.

    1992-07-01

    The objective of the work presented in this paper is to develop new, efficient catalysts for the selective transformation of the light alkanes in natural gas to alcohols for use as liquid transportation fuels, fuel precursors and chemical products. There currently exists no DIRECT one-step catalytic air-oxidation process to convert these substrates to alcohols. Such a one-step route would represent superior useful technology for the utilization of natural gas and similar refinery-derived light hydrocarbon streams. Processes for converting natural gas or its components (methane, ethane, propane, and the butanes) to alcohols for use as motor fuels, fuel additives or fuel precursors will not only add a valuable alternative to crude oil but will produce a clean-burning, high octane alternative to conventional gasoline.

  2. Spin-to-orbit conversion at acousto-optic diffraction of light: conservation of optical angular momentum.

    Science.gov (United States)

    Skab, Ihor; Vlokh, Rostyslav

    2012-04-01

    Acousto-optic diffraction of light in optically active cubic crystals is analyzed from the viewpoint of conservation of optical angular momentum. It is shown that the availability of angular momentum in the diffracted optical beam can be necessarily inferred from the requirements of angular momentum conservation law. As follows from our analysis, a circularly polarized diffracted wave should bear an orbital angular momentum. The efficiency of the spin-to-orbit momentum conversion is governed by the efficiency of acousto-optic diffraction.

  3. Does An Additional Uv Led Improve The Degree Of Conversion And Knoop Hardness Of Light-shade Composite Resins?

    OpenAIRE

    Giorgi M.C.C.; Aguiar F.H.B.; Soares L.E.S.; Martin A.A.; Liporoni P.C.S.; Paulillo L.A.M.S.

    2012-01-01

    Objective: The purpose of this study was to evaluate the degree of conversion (DC) using FT-Raman spectroscopy and the Knoop hardness (KHN) of composites cured by second and third-generation LED light curing-units (LCU), Radii Cal and Ultralume 5. Methods: Three composites (Filtek Supreme XT, Filtek Z350, and Esthet X) were selected for this study. KHN testing (n=10) was performed with 10 indentations for the top (T) and bottom (B) surfaces. For DC (n=10), both the T and B surfaces were analy...

  4. Light-Matter Interaction: Conversion of Optical Energy and Momentum to Mechanical Vibrations and Phonons

    CERN Document Server

    Mansuripur, Masud

    2016-01-01

    Reflection, refraction, and absorption of light by material media are, in general, accompanied by a transfer of optical energy and momentum to the media. Consequently, the eigen-modes of mechanical vibration (phonons) created in the process must distribute the acquired energy and momentum throughout the material medium. However, unlike photons, phonons do not carry momentum. What happens to the material medium in its interactions with light, therefore, requires careful consideration if the conservation laws are to be upheld. The present paper addresses some of the mechanisms by which the electromagnetic momentum of light is carried away by mechanical vibrations.

  5. Evaluation of aftermarket LPG conversion kits in light-duty vehicle applications. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Bass, E A [Southwest Research Inst., San Antonio, TX (US)

    1993-06-01

    SwRI was contracted by NREL to evaluate three LPG conversion kits on a Chevrolet Lumina. The objective of the project was to measure the Federal Test Procedure (FTP) emissions and fuel economy of these kits, and compare their performance to gasoline-fueled operation and to each other. Varying LPG fuel blends allowed a preliminary look at the potential for fuel system disturbance. The project required kit installation and adjustment according to manufacturer`s instructions. A limited amount of trouble diagnosis was also performed on the fuel systems. A simultaneous contract from the Texas Railroad Commission, in cooperation with NREL, provided funds for additional testing with market fuels (HD5 propane and industry average gasoline) and hydrocarbon (HC) emissions speciation to determine the ozone-forming potential of LPG HC emissions. This report documents the procurement, installation, and testing of these LPG conversion kits.

  6. “光陷阱”复合式太阳能发电系统%“Light trap”hybrid solar power conversion system

    Institute of Scientific and Technical Information of China (English)

    严祥安; 何伟康; 刘耀武; 杨志洁; 王凯

    2016-01-01

    为提高太阳光的利用率和电池板的转换效率,设计一种“光陷阱”复合式太阳能发电系统。通过“光陷阱”结构,将入射光困在由多种禁带宽度不同的薄膜太阳电池片组合结构中,形成多次反射,充分吸收各波段太阳光。同时增加水冷系统,带走多余热量,降低光伏电池温度,稳定工作效率。被加热的水可作为生活热水使用,节能环保。利用软件编程和数值模拟,优化“光陷阱”光伏电池的结构参数,结果表明当光线垂直入射时,该结构可使光线在“光陷阱”光伏电池内表面进行24次反射,每片电池片上平均反射6次,达到薄膜太阳能电池最佳光强效果。%A set of “light trap”hybrid solar power conversion system is designed for raising sunlight u-tilization and photoelectric conversion efficiency.The special “light trap”structure trap the incident light into a variety of different energy gap thin film solar cells.This structure forms multiple reflec-tions,and fully absorbs solar spectrum bands.The added cooling system takes away the excess heat, decreases the temperature of the photovoltaic cells,and stabilizes the work efficiency.The heated water can be used as domestic hot water supply.It is energy efficiency and environmental protection.The optimization structure parameters are determined by using the software programming and numerical simulation.The result shows that the structure can make the sunlight reflects 24 times on internal surface of “light trap”photovoltaic cells,6 times per cells,and achieves the best light intensity of the thin-film solar cells.

  7. Realistic vs sudden turn-on of natural incoherent light: Coherences and dynamics in molecular excitation and internal conversion

    Energy Technology Data Exchange (ETDEWEB)

    Grinev, Timur; Brumer, Paul [Chemical Physics Theory Group, Department of Chemistry, and Center for Quantum Information and Quantum Control, University of Toronto, Toronto, Ontario M5S 3H6 (Canada)

    2015-12-28

    Molecular excitation with incoherent light is examined using realistic turn-on time scales, and results are compared to those obtained via commonly used sudden turn-on, or pulses. Two significant results are obtained. First, in contrast to prior studies involving sudden turn-on, realistic turn-on is shown to lead to stationary coherences for natural turn-on time scales. Second, the time to reach the final stationary mixed state, known to result from incoherent excitation, is shown to depend directly on the inverse of the molecular energy level spacings, in both sudden and realistic turn-on cases. The S{sub 0} → S{sub 2}/S{sub 1} internal conversion process in pyrazine is used as an example throughout. Implications for studies of natural light harvesting systems are noted.

  8. Realistic vs sudden turn-on of natural incoherent light: Coherences and dynamics in molecular excitation and internal conversion.

    Science.gov (United States)

    Grinev, Timur; Brumer, Paul

    2015-12-28

    Molecular excitation with incoherent light is examined using realistic turn-on time scales, and results are compared to those obtained via commonly used sudden turn-on, or pulses. Two significant results are obtained. First, in contrast to prior studies involving sudden turn-on, realistic turn-on is shown to lead to stationary coherences for natural turn-on time scales. Second, the time to reach the final stationary mixed state, known to result from incoherent excitation, is shown to depend directly on the inverse of the molecular energy level spacings, in both sudden and realistic turn-on cases. The S0 → S2/S1 internal conversion process in pyrazine is used as an example throughout. Implications for studies of natural light harvesting systems are noted.

  9. Direct measurement of electron beam quality conversion factors using water calorimetry.

    Science.gov (United States)

    Renaud, James; Sarfehnia, Arman; Marchant, Kristin; McEwen, Malcolm; Ross, Carl; Seuntjens, Jan

    2015-11-01

    In this work, the authors describe an electron sealed water calorimeter (ESWcal) designed to directly measure absorbed dose to water in clinical electron beams and its use to derive electron beam quality conversion factors for two ionization chamber types. A functioning calorimeter prototype was constructed in-house and used to obtain reproducible measurements in clinical accelerator-based 6, 9, 12, 16, and 20 MeV electron beams. Corrections for the radiation field perturbation due to the presence of the glass calorimeter vessel were calculated using Monte Carlo (MC) simulations. The conductive heat transfer due to dose gradients and nonwater materials was also accounted for using a commercial finite element method software package. The relative combined standard uncertainty on the ESWcal dose was estimated to be 0.50% for the 9-20 MeV beams and 1.00% for the 6 MeV beam, demonstrating that the development of a water calorimeter-based standard for electron beams over such a wide range of clinically relevant energies is feasible. The largest contributor to the uncertainty was the positioning (Type A, 0.10%-0.40%) and its influence on the perturbation correction (Type B, 0.10%-0.60%). As a preliminary validation, measurements performed with the ESWcal in a 6 MV photon beam were directly compared to results derived from the National Research Council of Canada (NRC) photon beam standard water calorimeter. These two independent devices were shown to agree well within the 0.43% combined relative uncertainty of the ESWcal for this beam type and quality. Absorbed dose electron beam quality conversion factors were measured using the ESWcal for the Exradin A12 and PTW Roos ionization chambers. The photon-electron conversion factor, kecal, for the A12 was also experimentally determined. Nonstatistically significant differences of up to 0.7% were found when compared to the calculation-based factors listed in the AAPM's TG-51 protocol. General agreement between the relative

  10. Direct measurement of electron beam quality conversion factors using water calorimetry

    Energy Technology Data Exchange (ETDEWEB)

    Renaud, James, E-mail: james.renaud@mail.mcgill.ca; Seuntjens, Jan [Medical Physics Unit, McGill University, Montréal, Québec H3G 1A4 (Canada); Sarfehnia, Arman [Medical Physics Unit, McGill University, Montréal, Québec H3G 1A4, Canada and Department of Radiation Oncology, University of Toronto, Toronto, Ontario M5S 3E2 (Canada); Marchant, Kristin [Allan Blair Cancer Centre, Saskatchewan Cancer Agency, Regina, Saskatchewan S4T 7T1, Canada and Department of Oncology, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5A1 (Canada); McEwen, Malcolm; Ross, Carl [Ionizing Radiation Standards, National Research Council of Canada, Ottawa, Ontario K1A 0R6 (Canada)

    2015-11-15

    Purpose: In this work, the authors describe an electron sealed water calorimeter (ESWcal) designed to directly measure absorbed dose to water in clinical electron beams and its use to derive electron beam quality conversion factors for two ionization chamber types. Methods: A functioning calorimeter prototype was constructed in-house and used to obtain reproducible measurements in clinical accelerator-based 6, 9, 12, 16, and 20 MeV electron beams. Corrections for the radiation field perturbation due to the presence of the glass calorimeter vessel were calculated using Monte Carlo (MC) simulations. The conductive heat transfer due to dose gradients and nonwater materials was also accounted for using a commercial finite element method software package. Results: The relative combined standard uncertainty on the ESWcal dose was estimated to be 0.50% for the 9–20 MeV beams and 1.00% for the 6 MeV beam, demonstrating that the development of a water calorimeter-based standard for electron beams over such a wide range of clinically relevant energies is feasible. The largest contributor to the uncertainty was the positioning (Type A, 0.10%–0.40%) and its influence on the perturbation correction (Type B, 0.10%–0.60%). As a preliminary validation, measurements performed with the ESWcal in a 6 MV photon beam were directly compared to results derived from the National Research Council of Canada (NRC) photon beam standard water calorimeter. These two independent devices were shown to agree well within the 0.43% combined relative uncertainty of the ESWcal for this beam type and quality. Absorbed dose electron beam quality conversion factors were measured using the ESWcal for the Exradin A12 and PTW Roos ionization chambers. The photon-electron conversion factor, k{sub ecal}, for the A12 was also experimentally determined. Nonstatistically significant differences of up to 0.7% were found when compared to the calculation-based factors listed in the AAPM’s TG-51 protocol

  11. Size dependent cellular uptake, in vivo fate and light-heat conversion efficiency of gold nanoshells on silica nanorattles.

    Science.gov (United States)

    Liu, Huiyu; Liu, Tianlong; Li, Linlin; Hao, Nanjing; Tan, Longfei; Meng, Xianwei; Ren, Jun; Chen, Dong; Tang, Fangqiong

    2012-06-07

    Despite advances in photothermal therapy of gold nanoshells, reliable evaluations of their size dependence on the relative biological effects are needed. We report the size effects of PEGylated gold nanoshells on silica nanorattles (pGSNs) on their cellular uptake, in vivo fate and light-heat conversion efficiency in this study. The results indicate that smaller pGSNs have enhanced cellular uptake by the MCF-7 cells. For in vivo biodistribution study, pGSNs of different particle sizes (84-315 nm) distribute mainly in the liver and spleen in MCF-7 tumor-bearing BALB/c nude mice. Smaller pGSNs have a longer blood-circulation lifetime and higher light-heat conversion efficiency both in vitro and in vivo compared with larger ones. All three sizes of pGSNs can be excreted from the mice body at a slow rate and do not cause tissue toxicity after intravenous injection at a dosage of 20 mg kg(-1) for three times. The data support the feasibility of optimizing the therapeutic process for photothermal cell killing by plasmonic gold nanoshells.

  12. Feasibility Study of Supercritical Light Water Cooled Fast Reactors for Actinide Burning and Electric Power Production

    Energy Technology Data Exchange (ETDEWEB)

    Mac Donald, Philip Elsworth; Buongiorno, Jacopo; Davis, Cliff Bybee; Weaver, Kevan Dean

    2002-01-01

    The use of supercritical temperature and pressure light water as the coolant in a direct-cycle nuclear reactor offers potential for considerable plant simplification and consequent capital and O&M cost reduction compared with current light water reactor (LWR) designs. Also, given the thermodynamic conditions of the coolant at the core outlet (i.e. temperature and pressure beyond the water critical point), very high thermal efficiencies of the power conversion cycle are possible (i.e. up to 46%). Because no change of phase occurs in the core, the need for steam separators and dryers as well as for BWR-type recirculation pumps is eliminated, which, for a given reactor power, results in a substantially shorter reactor vessel than the current BWRs. Furthermore, in a direct cycle the steam generators are not needed. If a tight fuel rod lattice is adopted, it is possible to significantly reduce the neutron moderation and attain fast neutron energy spectrum conditions. In this project a supercritical water reactor concept with a simple, blanket-free, pancake-shaped core will be developed. This type of core can make use of either fertile or fertile-free fuel and retain the hard spectrum to effectively burn plutonium and minor actinides from LWR spent fuel while efficiently generating electricity.

  13. Energy conversion of biomass with supercritical and subcritical water using large-scale plants.

    Science.gov (United States)

    Okajima, Idzumi; Sako, Takeshi

    2014-01-01

    Exploiting unused or waste biomass as an alternative fuel is currently receiving much attention because of the potential reductions in CO2 emissions and the lower cost in comparison to expensive fossil fuels. If we are to use biomass domestically or industrially, we must be able to convert biomass to high-quality and easy-to-use liquid, gas, or solid fuels that have high-calorific values, low moisture and ash contents, uniform composition, and suitable for stored over long periods. In biomass treatment, hot and high-pressure water including supercritical and subcritical water is an excellent solvent, as it is clean and safe and its action on biomass can be optimized by varying the temperature and pressure. In this article, the conversion of waste biomass to fuel using hot and high-pressure water is reviewed, and the following examples are presented: the production of large amounts of hydrogen from waste biomass, the production of cheap bioethanol from non-food raw materials, and the production of composite powder fuel from refractory waste biomass in the rubble from the Great East Japan Earthquake. Several promising techniques for the conversion of biomass have been demonstrated in large-scale plants and commercial deployment is expected in the near future. Copyright © 2013. Published by Elsevier B.V.

  14. A memristor-based pixel implementing light-to-resistance conversion

    Science.gov (United States)

    Olumodeji, Olufemi A.; Bramanti, Alessandro P.; Gottardi, Massimo; Iannotta, Salvatore

    2016-02-01

    This letter reports a pixel architecture that implements a light-to-resistance encoder exploiting the properties of a memristor. A light-to-frequency (L2F) converter is adopted to drive a memristor with pulses, thus changing its resistance according with the light intensity. In a conventional L2F implementation, a binary counter is needed to store the number of pulses generated within the exposure time (Ti). In the proposed circuit, the binary counter has been replaced with an analog counterpart, made of a single memristor. This turns into a smaller pixel pitch, compared with an all-CMOS solution and analog nonvolatile characteristics. The proposed circuit has been simulated in a 3.3 V, 0.35 μm CMOS process, while the memristor behavior relies on the HP model.

  15. Degree of conversion of different composite resins photo-activated with light-emitting diode and argon ion laser

    Science.gov (United States)

    Messias, A. M.; Galvão, M. R.; Boaventura, J. M. C.; Jacomassi, D. P.; Bernardi, M. I. B.; Bagnato, V. S.; Rastelli, A. N. S.; Andrade, M. F.

    2015-02-01

    This study evaluated the degree of conversion (DC%) of one experimental and different brands of composite resins light-cured by two light sources (one LED and one argon laser). The percentage of unreacted C = C was determined from the ratio of absorbance intensities of aliphatic C = C (peak at 1637 cm-1) against internal standards before and after curing: aromatic C-C (peak at 1610 cm-1) except for P90, where %C = C bonds was given for C-O-C (883 cm-1) and C-C (1257 cm-1). ANOVA and Tukey’s test revealed no statistically significant difference among Z350 (67.17), Z250 (69.52) and experimental (66.61  ±  2.03) with LED, just among them and Evolu-X (75.51) and P90 (32.05) that showed higher and lower DC%, respectively. For the argon laser, there were no differences among Z250 (70.67), Z350 (69.60), experimental (65.66) and Evolu-X (73, 37), however a significant difference was observed for P90 (36.80), which showed lowest DC%. The light sources showed similar DC%, however the main difference was observed regarding the composite resins. The lowest DC% was observed for the argon laser. P90 showed the lowest DC% for both light-curing sources.

  16. Corrosion and Corrosion Control in Light Water Reactors

    Science.gov (United States)

    Gordon, Barry M.

    2013-08-01

    Serious corrosion problems have plagued the light water reactor (LWR) industry for decades. The complex corrosion mechanisms involved and the development of practical engineering solutions for their mitigation will be discussed in this article. After a brief overview of the basic designs of the boiling water reactor (BWR) and pressurized water reactor (PWR), emphasis will be placed on the general corrosion of LWR containments, flow-accelerated corrosion of carbon steel components, intergranular stress corrosion cracking (IGSCC) in BWRs, primary water stress corrosion cracking (PWSCC) in PWRs, and irradiation-assisted stress corrosion cracking (IASCC) in both systems. Finally, the corrosion future of both plants will be discussed as plants extend their period of operation for an additional 20 to 40 years.

  17. Elevated soil nitrogen pools after conversion of turfgrass to water-efficient residential landscapes

    Science.gov (United States)

    Heavenrich, Hannah; Hall, Sharon J.

    2016-08-01

    As a result of uncertain resource availability and growing populations, city managers are implementing conservation plans that aim to provide services for people while reducing household resource use. For example, in the US, municipalities are incentivizing homeowners to replace their water-intensive turfgrass lawns with water-efficient landscapes consisting of interspersed drought-tolerant shrubs and trees with rock or mulch groundcover (e.g. xeriscapes, rain gardens, water-wise landscapes). While these strategies are likely to reduce water demand, the consequences for other ecosystem services are unclear. Previous studies in controlled, experimental landscapes have shown that conversion from turfgrass to shrubs may lead to high rates of nutrient leaching from soils. However, little is known about the long-term biogeochemical consequences of this increasingly common land cover change across diverse homeowner management practices. We explored the fate of soil nitrogen (N) across a chronosequence of land cover change from turfgrass to water-efficient landscapes in privately owned yards in metropolitan Phoenix, Arizona, in the arid US Southwest. Soil nitrate ({{{{NO}}}3}--N) pools were four times larger in water-efficient landscapes (25 ± 4 kg {{{{NO}}}3}--N/ha 0-45 cm depth) compared to turfgrass lawns (6 ± 7 kg {{{{NO}}}3}--N/ha). Soil {{{{NO}}}3}--N also varied significantly with time since landscape conversion; the largest pools occurred at 9-13 years after turfgrass removal and declined to levels comparable to turfgrass thereafter. Variation in soil {{{{NO}}}3}--N with landscape age was strongly influenced by management practices related to soil water availability, including shrub cover, sub-surface plastic sheeting, and irrigation frequency. Our findings show that transitioning from turfgrass to water-efficient residential landscaping can lead to an accumulation of {{{{NO}}}3}--N that may be lost from the plant rooting zone over time following irrigation or

  18. Visible light water splitting using dye-sensitized oxide semiconductors.

    Science.gov (United States)

    Youngblood, W Justin; Lee, Seung-Hyun Anna; Maeda, Kazuhiko; Mallouk, Thomas E

    2009-12-21

    Researchers are intensively investigating photochemical water splitting as a means of converting solar to chemical energy in the form of fuels. Hydrogen is a key solar fuel because it can be used directly in combustion engines or fuel cells, or combined catalytically with CO(2) to make carbon containing fuels. Different approaches to solar water splitting include semiconductor particles as photocatalysts and photoelectrodes, molecular donor-acceptor systems linked to catalysts for hydrogen and oxygen evolution, and photovoltaic cells coupled directly or indirectly to electrocatalysts. Despite several decades of research, solar hydrogen generation is efficient only in systems that use expensive photovoltaic cells to power water electrolysis. Direct photocatalytic water splitting is a challenging problem because the reaction is thermodynamically uphill. Light absorption results in the formation of energetic charge-separated states in both molecular donor-acceptor systems and semiconductor particles. Unfortunately, energetically favorable charge recombination reactions tend to be much faster than the slow multielectron processes of water oxidation and reduction. Consequently, visible light water splitting has only recently been achieved in semiconductor-based photocatalytic systems and remains an inefficient process. This Account describes our approach to two problems in solar water splitting: the organization of molecules into assemblies that promote long-lived charge separation, and catalysis of the electrolysis reactions, in particular the four-electron oxidation of water. The building blocks of our artificial photosynthetic systems are wide band gap semiconductor particles, photosensitizer and electron relay molecules, and nanoparticle catalysts. We intercalate layered metal oxide semiconductors with metal nanoparticles. These intercalation compounds, when sensitized with [Ru(bpy)(3)](2+) derivatives, catalyze the photoproduction of hydrogen from sacrificial

  19. The Relationship of the Smectite-Illite Conversion to Pore Water Salinity Trends, Deep Water Offshore Niger Delta

    Science.gov (United States)

    Fitts, T. G.; Summa, L. L.

    2002-12-01

    Petroleum exploration in the deepwater Niger Delta has produced an abundance of physical property data and geochemical information in the section from 500 to 4000m below the seafloor. These have improved our understanding of the links between diagenetic processes and changes in pore fluid chemistry, and further suggest that smectite dehydration is not a major contributor to overpressure in the section. Literature data, coupled with new log, x-ray diffraction and surface area measurements, suggest that smectite and mixed-layer illite-smectite are major components of Miocene to Recent shales in key deep water wells. The smectite-illite transformation is generally complete by 2000m bml, corresponding to 80-90 degrees C. Such high percentages of hydrated clays result in sediments with low shallow overburden stresses, permeabilities and thermal conductivities. Because of the large contribution of smectite interlayer water to the total water content, diagenetic alteration of smectite more strongly affects density and pore fluid chemistry profiles here than in areas with less hydrated clay. Coincident with the conversion of smectite to illite, the total dissolved solids in the pore waters from several wells in the deepwater Niger Delta decrease from near seawater values at the sea floor to approximatly 10,000 ppm at 2000m bml. Pore fluid composition estimates are derived primarily from log calculation of water resistivity, with limited confirmation from pressure gradients in water legs, and uncontaminated MDT fluid samples. There are two models that could account for the observed decrease in salinity with depth: freshwater incursion via long-distance lateral fluid flow through continuous aquifers, and release of interlayer water from smectite during diagenesis. The available data suggest that release of interlayer water is the most likely explanation for the salinity observations from deep water Nigeria. Freshwater incursions are more likely on the shallow water shelf

  20. White Organic Light-emitting Diodes with A Sr2 SiO4:Eu3+ Color Conversion Layer%White Organic Light-emitting Diodes with A Sr2SiO4:Eu3+ Color Conversion Layer

    Institute of Scientific and Technical Information of China (English)

    Meiso Yokoyama

    2013-01-01

    Hybrid inorganic/organic white organic light emitting diodes (hybrid-WOLEDs) are fabricated by combining the blue phosphorescent organic light emitting diodes (PHOLEDs) with red Sr2 SiO4∶ Eu3+ phosphor spin coated as a color conversion layer (CCL) over the other side of glass substrate on the devices.The basic configuration of the PHOLEDs consists a host material,N,N'-dicarbazolyl-3,5-benzene (mCP) which doped with a blue phosphorescent iridium complexes iridium (Ⅲ)bis [(4,6-di-fluorophenyl)-pyridinato-N-C2'] (FIrpic) to produce high efficient blue organic light emitting diodes.The hybrid-WOLED shows maximum luminous efficiency of 22.1 cd/ A,maximum power efficiency of 11.26 lm/W,external quantum efficiency of 10.2% and CIE coordinates of (0.32,0.34).Moreover,the output spectra and CIE coordinates of the hybrid-WOLED have a small shift in different driving current density,which demonstrate good color stability.

  1. Q Conversion Factor Models for Estimating Precipitable Water Vapor for Turkey

    Science.gov (United States)

    Deniz, Ilke; Mekik, Cetin; Gurbuz, Gokhan

    2015-04-01

    precipitable water vapor is the conversion factor Q which is shown in Emardson and Derks' studies and also Jade and Vijayan's. Developing a regional model using either Tm-Ts equation or the conversion factor Q will provide a basis for GNSS Meteorology in Turkey which depends on the analysis of the radiosonde profile data. For this purpose, the radiosonde profiles from Istanbul, Ankara, Diyarbaki r, Samsun, Erzurum, Izmir, Isparta and Adana stations are analyzed with the radiosonde analysis algorithm in the context of the 'The Estimation of Atmospheric Water Vapour with GPS' Project which is funded by the Scientific and Technological Research Council of Turkey (TUBITAK). The Project is also in the COST Action ES1206: Advanced Global Navigation Satellite Systems tropospheric products for monitoring severe weather events and climate (GNSS4SWEC). In this study, regional models using the conversion factor Q are used for the determination of precipitable water vapor, and applied to the GNSS derived wet tropospheric zenith delays. Henceforth, the estimated precipitable water vapor and the precipitable water vapor obtained from the radiosonde station are compared. The average of the differences between RS and models for Istanbul and Ankara stations are obtained as 2.0±1.6 mm, 1.6±1.6 mm, respectively.

  2. Changes on degree of conversion of dual-cure luting light-cured with blue LED

    Science.gov (United States)

    Bandéca, M. C.; El-Mowafy, O.; Saade, E. G.; Rastelli, A. N. S.; Bagnato, V. S.; Porto-Neto, S. T.

    2009-05-01

    The indirect adhesive procedures constitute recently a substantial portion of contemporary esthetic restorative treatments. The resin cements have been used to bond tooth substrate and restorative materials. Due to recently introduction of the self-bonding resin luting cement based on a new monomer, filler and initiation technology has become important to study the degree of conversion of these new materials. In the present work the polymerization reaction and the filler content of dual-cured dental resin cements were studied by means of infra-red spectroscopy (FT-IR) and thermogravimetry (TG). Twenty specimens were made in a metallic mold (8 mm diameter × 1 mm thick) from each of 2 cements, Panavia® F2.0 (Kuraray) and RelyX™ Unicem Applicap (3M/ESPE). Each specimen was cured with blue LED with power density of 500 mW/cm2 for 30 s. Immediately after curing, 24 and 48 h, and 7 days DC was determined. For each time interval 5 specimens were pulverized, pressed with KBr and analyzed with FT-IR. The TG measurements were performed in Netzsch TG 209 under oxygen atmosphere and heating rate of 10°C/min from 25 to 700°C. A two-way ANOVA showed DC (%) mean values statistically significance differences between two cements ( p 0.05). The Relx-Y™ Unicem mean values were significantly higher than Panavia® F 2.0. The degree of conversion means values increasing with the storage time and the filler content showed similar for both resin cements.

  3. A Reversed Photosynthesis-like Process for Light-Triggered CO2 Capture, Release, and Conversion.

    Science.gov (United States)

    Wang, Dingguan; Liao, Shenglong; Zhang, Shiming; Wang, Yapei

    2017-06-22

    Materials for CO2 capture have been extensively exploited for climate governance and gas separation. However, their regeneration is facing the problems of high energy cost and secondary CO2 contamination. Herein, a reversed photosynthesis-like process is proposed, in which CO2 is absorbed in darkness while being released under light illumination. The process is likely supplementary to natural photosynthesis of plants, in which, on the contrary, CO2 is released during the night. Remarkably, the material used here is able to capture 9.6 wt.% CO2 according to its active component. Repeatable CO2 capture at room temperature and release under light irradiation ensures its convenient and cost-effective regeneration. Furthermore, CO2 released from the system is successfully converted into a stable compound in tandem with specific catalysts. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Nickel Catalyzed Conversion of Cyclohexanol into Cyclohexylamine in Water and Low Boiling Point Solvents

    Directory of Open Access Journals (Sweden)

    Yunfei Qi

    2016-04-01

    Full Text Available Nickel is found to demonstrate high performance in the amination of cyclohexanol into cyclohexylamine in water and two solvents with low boiling points: tetrahydrofuran and cyclohexane. Three catalysts, Raney Ni, Ni/Al2O3 and Ni/C, were investigated and it is found that the base, hydrogen, the solvents and the support will affect the activity of the catalyst. In water, all the three catalysts achieved over 85% conversion and 90% cyclohexylamine selectivity in the presence of base and hydrogen at a high temperature. In tetrahydrofuran and cyclohexane, Ni/Al2O3 exhibits better activity than Ni/C under optimal conditions. Ni/C was stable during recycling in aqueous ammonia, while Ni/Al2O3 was not due to the formation of AlO(OH.

  5. Conversion of Dynamic High Pressures from Air to Water for a Spherical TNT Charge

    Directory of Open Access Journals (Sweden)

    A. K. Sharma

    1996-01-01

    Full Text Available A numerical method has been applied to convert the dynamic high pressures from air-to-water for a spherical TNT charge. Standard equation of scaling law in air for TNT has been utilised to make the necessary conversions. The investigations have been made by taking into consideration the ambient pressure values for the two media. The calculations have been performed under the scaled distances to get better results. Experimental measurements using indigenous blast pressure gauge have been undertaken by detonating spherical charges of TNT under the same scaled distances in water to check the correctness of results and direct application of this method. A fairly close agreement between the theoretically computed and the experimental values of the dynamic high pressures shows the practical utility of this approach in that it enables an estimate of the experimental shock wave pressures, without conducting underwater experiments.

  6. Synthesis of Concentrated Methylcyclohexane as Hydrogen Carrier through Photoelectrochemical Conversion of Toluene and Water.

    Science.gov (United States)

    Kageshima, Yosuke; Minegishi, Tsutomu; Hisatomi, Takashi; Takata, Tsuyoshi; Kubota, Jun; Domen, Kazunari

    2017-02-22

    A photoelectrochemical (PEC) cell consisting of a Pt-loaded carbon black (Pt/C)-based membrane electrode assembly (MEA) and a particulate SrTiO3 photoanode effected selective PEC conversion of toluene and water into methylcyclohexane (MCH) at concentrations up to >99 vol %. This cell exhibited 100 % faradaic efficiency (FE) and 18 % incident-photon-to-current conversion efficiency (IPCE) at 320 nm without an external bias voltage in the PEC hydrogenation of pure toluene. It was also found that strong alkaline conditions are beneficial with the present MEA to suppress the competitive side reaction of hydrogen evolution, resulting in a high FE of 94 % even during MCH production from 1 vol % toluene in MCH. This study successfully demonstrated that the present PEC system is capable of producing concentrated MCH as a promising hydrogen carrier and that MCH production from toluene and water represents a means of artificial photosynthesis. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. Dual-Layer Nanostructured Flexible Thin-Film Amorphous Silicon Solar Cells with Enhanced Light Harvesting and Photoelectric Conversion Efficiency.

    Science.gov (United States)

    Lin, Yinyue; Xu, Zhen; Yu, Dongliang; Lu, Linfeng; Yin, Min; Tavakoli, Mohammad Mahdi; Chen, Xiaoyuan; Hao, Yuying; Fan, Zhiyong; Cui, Yanxia; Li, Dongdong

    2016-05-04

    Three-dimensional (3-D) structures have triggered tremendous interest for thin-film solar cells since they can dramatically reduce the material usage and incident light reflection. However, the high aspect ratio feature of some 3-D structures leads to deterioration of internal electric field and carrier collection capability, which reduces device power conversion efficiency (PCE). Here, we report high performance flexible thin-film amorphous silicon solar cells with a unique and effective light trapping scheme. In this device structure, a polymer nanopillar membrane is attached on top of a device, which benefits broadband and omnidirectional performances, and a 3-D nanostructure with shallow dent arrays underneath serves as a back reflector on flexible titanium (Ti) foil resulting in an increased optical path length by exciting hybrid optical modes. The efficient light management results in 42.7% and 41.7% remarkable improvements of short-circuit current density and overall efficiency, respectively. Meanwhile, an excellent flexibility has been achieved as PCE remains 97.6% of the initial efficiency even after 10 000 bending cycles. This unique device structure can also be duplicated for other flexible photovoltaic devices based on different active materials such as CdTe, Cu(In,Ga)Se2 (CIGS), organohalide lead perovskites, and so forth.

  8. Application of ZnO single crystals for light-induced water splitting under UV irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Suhak, Yuriy, E-mail: suhak@ifpan.edu.pl [Institute of Physics, Polish Academy of Sciences, Al. Lotników 32/46, 02-668 Warsaw (Poland); Izdebska, Katarzyna; Skupiński, Paweł; Wierzbicka, Aleksandra; Reszka, Anna; Sybilski, Piotr; Kowalski, Bogdan J.; Mycielski, Andrzej; Zytkiewicz, Zbigniew R. [Institute of Physics, Polish Academy of Sciences, Al. Lotników 32/46, 02-668 Warsaw (Poland); Soszko, Michał [Industrial Chemistry Research Institute, Rydygiera 8, 01-793 Warsaw (Poland); Suchocki, Andrzej [Institute of Physics, Polish Academy of Sciences, Al. Lotników 32/46, 02-668 Warsaw (Poland); Institute of Physics, University of Bydgoszcz, Weyssenhoffa 11, 85-072 Bydgoszcz (Poland)

    2014-02-14

    This paper presents experimental results of implementation of ZnO single crystals as photoanodes in photoelectrochemical (PEC) cells for hydrogen generation through the process of water splitting. Both, as-grown and O{sub 2}-annealed ZnO single crystals were investigated for this purpose. A 351 nm argon laser line was used as the light source. The XRD investigations showed that used ZnO crystals are of good crystalline quality. It was found that the as-grown ZnO single crystals possess higher conversion efficiencies comparing to the O{sub 2}-annealed one. The photocurrent density was found to increase significantly with the increase of external bias applied and excitation light intensity. Time dependent photocurrent density characteristics showed that the decay of photocurrent density was not observed within the measurement time. The differences in behaviour of the as-grown and the annealed in O{sub 2} ZnO single crystals are discussed in terms of crystals intrinsic defects. - Highlights: • ZnO single crystals show excellent performance as photoanodes for water splitting. • ZnO single crystals showed good stability in aqueous solution. • Mid-gap band state introduction does not influence the efficiency of water splitting.

  9. Study of Syngas Conversion to Light Olefins by Response Surface Methodology

    Directory of Open Access Journals (Sweden)

    Hossein Atashi

    2013-01-01

    Full Text Available The effect of adding MgO to a precipitated iron-cobalt-manganese based Fischer-Tropsch synthesis (FTS catalyst was investigated via response surface methodology. The catalytic performance of the catalysts was examined in a fixed bed microreactor at a total pressure of 1–7 bar, temperature of 280–380°C, MgO content of 5–25% and using a syngas having a H2 to CO ratio equal to 2.The dependence of the activity and product distribution on MgO content, temperature, and pressure was successfully correlated via full quadratic second-order polynomial equations. The statistical analysis and response surface demonstrations indicated that MgO significantly influences the CO conversion and chain growth probability as well as ethane, propane, propylene, butylene selectivity, and alkene/alkane ratio. A strong interaction between variables was also evidenced in some cases. The decreasing effect of pressure on alkene to alkane ratio is investigated through olefin readsorption effects and CO hydrogenation kinetics. Finally, a multiobjective optimization procedure was employed to calculate the best amount of MgO content in different reactor conditions.

  10. Free-space spectro-temporal and spatio-temporal conversion for pulsed light

    CERN Document Server

    Poem, Eilon; Eckstein, Andreas; Jin, Xian-Min; Walmsley, Ian A

    2016-01-01

    We present an apparatus that converts every pulse of a pulsed light source to a pulse train in which the intensities of the different pulses are samples of the spatial or temporal frequency spectrum of the original pulse. In this way, the spectrum of the incident light can be measured by following the temporal response of a single detector. The apparatus is based on multiple round-trips inside a 2f- cavity-like mirror arrangement in which the spectrum is spread on the back focal plane, where after each round-trip a small section of the spectrum is allowed to escape. The apparatus is fibre-free, offers easy wavelength range tunability, and a prototype built achieves over 10% average efficiency in the near infra red. We demonstrate the application of the prototype for the efficient measurement of the joint spectrum of a non-degenerate bi-photon source in which one of the photons is in the near infra red.

  11. Ortho-para conversion of endohedral water in the fullerene C60 at cryogenic temperatures

    Science.gov (United States)

    Shugai, Anna; Nagel, U.; Rõõm, T.; Mamone, S.; Concistrè, M.; Meier, B.; Krachmalnicoff, A.; Whitby, R. J.; Levitt, M. H.; Lei, Xuegong; Li, Yongjun; Turro, N. J.

    2015-03-01

    Water displays the phenomenon of spin isomerism in which the two proton spins either couple to form a triplet (ortho water, I = 1) or a singlet nuclear spin state (para water, I = 0). Here we study the interconversion of para and ortho water. The exact mechanism of this process is still not fully understood. In order to minimize interactions between molecules we use a sample where a single H2O is trapped in the C60 molecular cage (H2O@C60)andH2O@C60iscrystallized.H2O@C60 has long-lived ortho state and ortho-para conversion kinetics is non-exponential at LHeT. We studied mixtures of H2O@C60, D2O@C60 and C60 using IR absorption, NMR and dielectric measurements. We saw the speeding up of the interconversion with the growth of H2O@C60 concentration in C60 or when D2O@C60 was added. At some temperatures the kinetics is exponential. Models are discussed in order to explain the T and concentration dependence of ortho-para interconversion kinetics. This work was supported by institutional research funding IUT23-3 of the Estonian Ministry of Education and Research.

  12. STUDY OF THE EFFECT OF ENDFACES POLISHING ANGLE FOR ANISOTROPIC WAVEGUIDES ON STATE CONVERSION OF LIGHT POLARIZATION

    Directory of Open Access Journals (Sweden)

    V. A. Shulepov

    2016-05-01

    Full Text Available The paper deals with optical scheme for research of polarization state transformation at the junction of anisotropic waveguides. It consists of a light source, polarization controller, multifunctional integrated optical scheme (MIOS, single-mode fiber for input and output of optical radiation in MIOS and the polarization scanning Michelson interferometer. Optical radiation from the source of the plant comes through the polarization controller in one of the MIOS ports. Further, in one of the opposite ports the radiation is received by different fibers, polished at the angles of 19.5˚, 10.5˚ and 0˚. After that, the optical radiation gets into polarization Michelson interferometer. With that, the picture visibility is analyzed at different displacement of one arm upon which the value has been determined in the polarization conversion point connections. At the course of work it was obtained that the polarization state conversion at a splicing point rises with the slant angle deviation from its optimal value. Anisotropic waveguides splicing is one of the main tasks during fabrication of any fiber-optic sensor with integrated optical elements. The results of this work are of great interest for the wide range of specialists in the optical waveguides application field.

  13. Conversion characteristics and mechanism analysis of gaseous dichloromethane degraded by a VUV light in different reaction media

    Institute of Scientific and Technical Information of China (English)

    Jianming Yu; Wenji Cai; Jianmeng Chen; Li Feng; Yifeng Jiang; Zhuowei Cheng

    2012-01-01

    The photodegradation of gaseous dichloromethane (DCM) by a vacuum ultraviolet (VUV) light in a spiral reactor was investigated with different reaction media and initial concentrations.Through the combination of direct photolysis,O3 oxidation and HO oxidation,DCM was ultimately mineralized into inorganic compounds (such as HCl,CO2,H2O,etc.) in the air with relative humidity (RH) of 75%-85%.During the photodegradation process,some small organic acids (including formic acid,acetic acid) were also detected and the intermediates were more soluble than DCM,providing a possibility for its combination with subsequent biodegradation.Based on the detected intermediates and the confirmed radicals,a photodegradation pathway of DCM by VUV was proposed.With RH 75%-80% air as the reaction medium,the DCM removal followed the second-order kinetic model at inlet concentration of 100-1000 mg/m3.Kinetic analysis showed that the reaction media affected the kinetic constants of DCM conversion by a large extent,and RH 80% air could cause a much lower half-life for its conversion.Such results supported the possibility that VUV photodegradation could be used not only for the mineralization of DCM but also as a pretreatment before biodegradation.

  14. [Research on the Highly Stable White LED with CdSe/ZnS Quantum Dot as Light Conversion Layer].

    Science.gov (United States)

    Cao, Jin; Zhou, Jie; Xie, Jing-weil; Chen, An-ping; Zhang, Xuel; Yin, Lu-qiao; Zhang, Jian-hua

    2016-02-01

    In accordance with the one-step synthesis, in this paper, we synthesized 510, 550 and 630 nm three emission peaks CdSe/ZnS core-shell quantum dots with high stability and high quantum yield whose quantum yield were 82%, 98% and 97%. We used the quantum dot material to replace the phosphor material, and mixed QDs with the silicone uniformly, then dispersed the QDs/silicone composites onto the blue InGaN LEDs to fabricate the QDs-WLEDs. By successively adding different colors of quantum dots for the preparation of quantum dot light converting layer, We investigated that how does the ratio of the three kind of quantum dots whose peaks were 510, 550 and 630 nm effect on the properties of the white LED devices. This paper also studied the mechanism of energy conversion between different colors of quantum dots. We also utilized the mechanism that the quantum dots effect on the white spectrum and color coordinates; we got the results of the optimization of the white device and the ratio of three-color quantum dots. The results show that when the quantum dot ratio is 24:7:10, white LED devices with high stability and high efficiency can be obtained, in the current range of 20-200 mA, the range of color temperature is from 4 607 to 5 920 K, the CIE-1931 coordinates is from (0.355 1,0.348 3) to (0.323 4, 0.336 1), the color rendering index is from 77. 6 to 84. 2, and the highest power efficiency of the devices achieves to 31.69 lm · W⁻¹ @ 20 mA. In addition, in order to further investigate the reason of stable device performance, We studied the effects of time, temperature, UV treatment on the stability of CdSe/ZnS QDs/silicone light conversion material, the results show that the excellent stability of the devices attributes to the stability of the one-step synthesis of core-shell structure of the quantum dot material, the final optimized device is a low-power high-quality white light source and the device has good application prospects in the field of standard white

  15. Feasibility Study of Supercritical Light Water Cooled Fast Reactors for Actinide Burning and Electric Power Production, 3rd Quarterly Report

    Energy Technology Data Exchange (ETDEWEB)

    Mac Donald, Philip Elsworth

    2002-06-01

    The use of light water at supercritical pressures as the coolant in a nuclear reactor offers the potential for considerable plant simplification and consequent capital and O&M cost reduction compared with current light water reactor (LWR) designs. Also, given the thermodynamic conditions of the coolant at the core outlet (i.e. temperature and pressure beyond the water critical point), very high thermal efficiencies of the power conversion cycle are possible (i.e. up to about 45%). Because no change of phase occurs in the core, the need for steam separators and dryers as well as for BWR-type re-circulation pumps is eliminated, which, for a given reactor power, results in a substantially shorter reactor vessel and smaller containment building than the current BWRs. Furthermore, in a direct cycle the steam generators are not needed.

  16. Cost analysis model for catalytic conversion of syngas in to light hydrocarbon gases

    Directory of Open Access Journals (Sweden)

    Yangyang Deng

    2015-05-01

    Full Text Available Bio-gasification is a new technology and considered as a more efficient way to utilize bio-energy. The economic feasibility becomes one of the greatest issues when we apply this new technology. Evaluation of economic feasibility of a bio-gasification facility needs better understanding of its production unit cost under different capacities and different working shift modes. The objective of this study was to evaluate the unit cost of biofuel products (Liquid HCs, Light HCs and Oxygenates CxHyOz under different capacities using a modeling method. The cost analysis model was developed using Visual Basic Microsoft 2008, computer programming language and mathematical equations. The modeling results showed that the unit costs of biofuel product from bio-gasification facility were significantly affected by production capacities of facilities. As the facility capacity increased from 65 to 10,000 N m3 h−1, the biofuel production unit cost of gas (Light HCs, oil (Liquid HCs, and aqueous (Oxygenates CxHyOz decreased from $38.92 per MMBTU, $30.89 per gallon and $25.74 per gallon to $2.01 per MMBTU, $1.59 per gallon, and $1.33 per gallon, respectively. The results of the sensitivity analysis showed that feedstock cost was the most sensitive cost factor on unit costs for all biofuel products at high capacity. The cost analysis model developed in this study could be used to optimize production unit costs of bio-fuel products from bio-gasification facility.

  17. Scaling up nanoscale water-driven energy conversion into evaporation-driven engines and generators

    Science.gov (United States)

    Chen, Xi; Goodnight, Davis; Gao, Zhenghan; Cavusoglu, Ahmet H.; Sabharwal, Nina; Delay, Michael; Driks, Adam; Sahin, Ozgur

    2015-06-01

    Evaporation is a ubiquitous phenomenon in the natural environment and a dominant form of energy transfer in the Earth's climate. Engineered systems rarely, if ever, use evaporation as a source of energy, despite myriad examples of such adaptations in the biological world. Here, we report evaporation-driven engines that can power common tasks like locomotion and electricity generation. These engines start and run autonomously when placed at air-water interfaces. They generate rotary and piston-like linear motion using specially designed, biologically based artificial muscles responsive to moisture fluctuations. Using these engines, we demonstrate an electricity generator that rests on water while harvesting its evaporation to power a light source, and a miniature car (weighing 0.1 kg) that moves forward as the water in the car evaporates. Evaporation-driven engines may find applications in powering robotic systems, sensors, devices and machinery that function in the natural environment.

  18. Spent fuel data base: commercial light water reactors. [PWR; BWR

    Energy Technology Data Exchange (ETDEWEB)

    Hauf, M.J.; Kniazewycz, B.G.

    1979-12-01

    As a consequence of this country's non-proliferation policy, the reprocessing of spent nuclear fuel has been delayed indefinitely. This has resulted in spent light water reactor (LWR) fuel being considered as a potential waste form for disposal. Since the Nuclear Regulatory Commission (NRC) is currently developing methodologies for use in the regulation of the management and disposal of high-level and transuranic wastes, a comprehensive data base describing LWR fuel technology must be compiled. This document provides that technology baseline and, as such, will support the development of those evaluation standards and criteria applicable to spent nuclear fuel.

  19. Nuclear safety in light water reactors severe accident phenomenology

    CERN Document Server

    Sehgal, Bal Raj

    2011-01-01

    This vital reference is the only one-stop resource on how to assess, prevent, and manage severe nuclear accidents in the light water reactors (LWRs) that pose the most risk to the public. LWRs are the predominant nuclear reactor in use around the world today, and they will continue to be the most frequently utilized in the near future. Therefore, accurate determination of the safety issues associated with such reactors is central to a consideration of the risks and benefits of nuclear power. This book emphasizes the prevention and management of severe accidents to teach nuclear professionals

  20. Catalytic Conversion of Glucose into 5-Hydroxymethylfurfural by Hf(OTf4 Lewis Acid in Water

    Directory of Open Access Journals (Sweden)

    Junjie Li

    2015-12-01

    Full Text Available A series of Lewis acidic metal salts were used for glucose dehydration to 5-hydroymethylfurfural (HMF in water. Effect of valence state, ionic radii of Lewis acidic cation, and the type of anions on the catalytic performance have been studied systematically. The experimental results showed that the valence state played an important role in determining catalytic activity and selectivity. It was found that a higher glucose conversion rate and HMF selectivity could be obtained over high valent Lewis acid salts, where the ionic radii of these Lewis acidic metal salts are usually relatively small. Analysis on the effect of the anions of Lewis acid salts on the catalytic activity and the selectivity suggested that a higher glucose conversion and HMF selectivity could be readily obtained with Cl−. Furthermore, the recyclability of high valence state Lewis acid salt was also studied, however, inferior catalytic performance was observed. The deactivation mechanism was speculated to be the fact that high valence state Lewis acid salt was comparatively easier to undergo hydrolysis to yield complicated metal aqua ions with less catalytic activity. The Lewis acidic activity could be recovered by introducing a stoichiometric amount of hydrochloric acid (HCl to the catalytic before the reaction.

  1. Mechanisms of energy transfer and conversion in plant Light-Harvesting Complex II

    Energy Technology Data Exchange (ETDEWEB)

    Barros, Tiago Ferreira de

    2009-09-24

    The light-harvesting complex of photosystem II (LHC-II) is the major antenna complex in plant photosynthesis. It accounts for roughly 30% of the total protein in plant chloroplasts, which makes it arguably the most abundant membrane protein on Earth, and binds about half of plant chlorophyll (Chl). The complex assembles as a trimer in the thylakoid membrane and binds a total of 54 pigment molecules, including 24 Chl a, 18 Chl b, 6 lutein (Lut), 3 neoxanthin (Neo) and 3 violaxanthin (Vio). LHC-II has five key roles in plant photosynthesis. It: (1) harvests sunlight and transmits excitation energy to the reaction centres of photosystems II and I, (2) regulates the amount of excitation energy reaching each of the two photosystems, (3) has a structural role in the architecture of the photosynthetic supercomplexes, (4) contributes to the tight appression of thylakoid membranes in chloroplast grana, and (5) protects the photosynthetic apparatus from photo damage by non photochemical quenching (NPQ). A major fraction of NPQ is accounted for its energy-dependent component qE. Despite being critical for plant survival and having been studied for decades, the exact details of how excess absorbed light energy is dissipated under qE conditions remain enigmatic. Today it is accepted that qE is regulated by the magnitude of the pH gradient ({delta}pH) across the thylakoid membrane. It is also well documented that the drop in pH in the thylakoid lumen during high-light conditions activates the enzyme violaxanthin de-epoxidase (VDE), which converts the carotenoid Vio into zeaxanthin (Zea) as part of the xanthophyll cycle. Additionally, studies with Arabidopsis mutants revealed that the photosystem II subunit PsbS is necessary for qE. How these physiological responses switch LHC-II from the active, energy transmitting to the quenched, energy-dissipating state, in which the solar energy is not transmitted to the photosystems but instead dissipated as heat, remains unclear and is the

  2. Fuel Summary Report: Shippingport Light Water Breeder Reactor - Rev. 2

    Energy Technology Data Exchange (ETDEWEB)

    Olson, Gail Lynn; Mc Cardell, Richard Keith; Illum, Douglas Brent

    2002-09-01

    The Shippingport Light Water Breeder Reactor (LWBR) was developed by Bettis Atomic Power Laboratory to demonstrate the potential of a water-cooled, thorium oxide fuel cycle breeder reactor. The LWBR core operated from 1977-82 without major incident. The fuel and fuel components suffered minimal damage during operation, and the reactor testing was deemed successful. Extensive destructive and nondestructive postirradiation examinations confirmed that the fuel was in good condition with minimal amounts of cladding deformities and fuel pellet cracks. Fuel was placed in wet storage upon arrival at the Expended Core Facility, then dried and sent to the Idaho Nuclear Technology and Engineering Center for underground dry storage. It is likely that the fuel remains in good condition at its current underground dry storage location at the Idaho Nuclear Technology and Engineering Center. Reports show no indication of damage to the core associated with shipping, loading, or storage.

  3. Fullerene-Based Supramolecular Nanoclusters with Poly[2-methoxy-5-(2'-ethylhexyloxy)-p-phenylenevinylene] for Light Energy Conversion

    Science.gov (United States)

    Hasobe, Taku; Fukuzumi, Shunichi; Kamat, Prashant V.; Murata, Hideyuki

    2008-02-01

    Organized composite molecular nanoassemblies of fullerene and poly[2-methoxy-5-(2'-ethylhexyloxy)-p-phenylenevinylene] (MEH-PPV) prepared in acetonitrile/toluene mixed solvent absorb light over the entire spectrum of visible light. The highly colored composite clusters can be assembled as a three-dimensional array onto nanostructured SnO2 films by electrophoretic deposition approach. The composite cluster films exhibit an incident photon-to-photocurrent efficiency (IPCE) as high as 18%, which is significantly higher than that of a molecular assembly composed of 5,10,15,20-tetrakis(3,5-di-tert-butylphenyl)-21H,23H-porphyrin (H2P) and C60 prepared in the same manner (4%). The maximum IPCE value increases to 25% at an applied bias potential of 0.2 V vs saturated calomel reference electrode (SCE). The power conversion efficiency of a MEH-PPV and C60 assembly-modified electrode is determined to be 0.24%. The photocurrent generation properties observed with MEH-PPV and C60 clusters demonstrate the synergy of these systems towards yielding efficient photoinduced charge separation within these composite nanoclusters.

  4. In Situ Catalytic Pyrolysis of Low-Rank Coal for the Conversion of Heavy Oils into Light Oils

    Directory of Open Access Journals (Sweden)

    Muhammad Nadeem Amin

    2017-01-01

    Full Text Available Lighter tars are largely useful in chemical industries but their quantity is quite little. Catalytic cracking is applied to improve the yield of light tars during pyrolysis. Consequently, in situ upgrading technique through a MoS2 catalyst has been explored in this research work. MoS2 catalyst is useful for the conversion of high energy cost into low energy cost. The variations in coal pyrolysis tar without and with catalyst were determined. Meanwhile, the obtained tar was analyzed using simulated distillation gas chromatograph and Elemental Analyzer. Consequently, the catalyst reduced the pitch contents and increased the fraction of light tar from 50 to 60 wt.% in coal pyrolysis tar. MoS2 catalyst increased the liquid yield from 18 to 33 (wt.%, db and decreased gas yield from 27 to 12 (wt.%, db compared to coal without catalyst. Moreover, it increased H content and hydrogen-to-carbon ratio by 7.9 and 3.3%, respectively, and reduced the contents of nitrogen, sulphur, and oxygen elements by 8.1%, 15.2%, and 23.9%, respectively, in their produced tars compared to coal without catalyst.

  5. Tritium distribution modeling in a Light Water New Production Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Jaeckle, J.W.

    1989-05-01

    The tritium distribution and tritium release pathways in a new light water production reactor were examined. A computer model was developed to track the tritium as it makes its way through the various plant systems and ends up either as a release to the atmosphere, the cooling tower blowdown or to the solid waste system. The model was designed to predict the integrated yearly tritium releases and provide estimated airborne tritium concentrations in various locations within the plant. WNP-1 was used as a representative model for a Light Water New Production Reactor (LWNPR). The Tritium Distribution Model solves for the time dependent tritium concentration in a system of nodes. These nodes are connected to one another via a set of internodal flow paths and to various sources and sinks. For example, plant systems such as the primary system are the nodes, piping and leaks are the internodal flow paths, make-up water is a source, and release to the atmosphere is a sink. The expected water mass of each node; the flow rates between nodes, sources, and sinks; and tritium source rates are provided as input. The code will solve for the time dependent tritium concentration in each node and the amount of tritium ''released'' to the sinks. Preliminary calculations have been performed using WNP-1 plant specific information obtained primarily from the WNP-1 FSAR. Further work is currently in progress to refine the model and provide a more realistic set of input values which will better represent an operating LWNPR. 1 ref., 1 fig., 1 tab.

  6. Conversion of agricultural residues into activated carbons for water purification: Application to arsenate removal.

    Science.gov (United States)

    Torres-Perez, Jonatan; Gerente, Claire; Andres, Yves

    2012-01-01

    The conversion of two agricultural wastes, sugar beet pulp and peanut hulls, into sustainable activated carbons is presented and their potential application for the treatment of arsenate solution is investigated. A direct and physical activation is selected as well as a simple chemical treatment of the adsorbents. The material properties, such as BET surface areas, porous volumes, elemental analysis, ash contents and pH(PZC), of these alternative carbonaceous porous materials are determined and compared with a commercial granular activated carbon. An adsorption study based on experimental kinetic and equilibrium data is conducted in a batch reactor and completed by the use of different models (intraparticle diffusion, pseudo-second-order, Langmuir and Freundlich) and by isotherms carried out in natural waters. It is thus demonstrated that sugar beet pulp and peanut hulls are good precursors to obtain activated carbons for arsenate removal.

  7. Direct conversion of cellulose to glycolic acid with a phosphomolybdic acid catalyst in a water medium

    KAUST Repository

    Zhang, Jizhe

    2012-08-03

    Direct conversion of cellulose to fine chemicals has rarely been achieved. We describe here an eco-benign route for directly converting various cellulose-based biomasses to glycolic acid in a water medium and oxygen atmosphere in which heteromolybdic acids act as multifunctional catalysts to catalyze the hydrolysis of cellulose, the fragmentation of monosaccharides, and the selective oxidation of fragmentation products. With commercial α-cellulose powder as the substrate, the yield of glycolic acid reaches 49.3%. This catalytic system is also effective with raw cellulosic biomass, such as bagasse or hay, as the starting materials, giving rise to remarkable glycolic acid yields of ∼30%. Our heteropoly acid-based catalyst can be recovered in solid form after reaction by distilling out the products and solvent for reuse, and it exhibits consistently high performance in multiple reaction runs. © 2012 American Chemical Society.

  8. Efficiencies and Physical Principles of Various Solar Energy Conversion Processes Leading to the Photolysis of Water

    Energy Technology Data Exchange (ETDEWEB)

    Bergene, T.

    1995-12-31

    In the application of solar energy, hydrogen is likely to be used as an energy carrier and a storage medium. Production of molecular hydrogen and oxygen from water requires energy input, which may come from solar energy in various ways. This thesis begins with a literature survey of the different conversion processes and the efficiencies, which is an introduction to a series of enclosed papers. These papers are: (1) Trapping of Minority Charge Carriers at Irradiated Semiconductor/Electrolyte Heterojunctions, (2) Model Calculations on Flat-Plate Solar Heat Collector With Integrated Solar Cells, and (3) Efficiencies and Physical Principles of Photolysis of Water By Microalgae. In the papers, The qualitative features of the ``illumination-current``-characteristic curve are deduced. The hypothesis is that trapping originates in some specific cases because of confinement, which leads to charge injections into energy states above that corresponding to the band edge. The quantitative features of certain hybrid photovoltaic/thermal configuration are deduced. An analysis of the theoretical and realizable efficiencies of the photolysis of water by micro algae is given. 151 refs., 18 figs., 1 table

  9. Silicon carbide composite for light water reactor fuel assembly applications

    Science.gov (United States)

    Yueh, Ken; Terrani, Kurt A.

    2014-05-01

    The feasibility of using SiCf-SiCm composites in light water reactor (LWR) fuel designs was evaluated. The evaluation was motivated by the desire to improve fuel performance under normal and accident conditions. The Fukushima accident once again highlighted the need for improved fuel materials that can maintain fuel integrity to higher temperatures for longer periods of time. The review identified many benefits as well as issues in using the material. Issues perceived as presenting the biggest challenges to the concept were identified to be flux gradient induced differential volumetric swelling, fragmentation and thermal shock resistance. The oxidation of silicon and its release into the coolant as silica has been identified as an issue because existing plant systems have limited ability for its removal. Detailed evaluation using available literature data and testing as part of this evaluation effort have eliminated most of the major concerns. The evaluation identified Boiling Water Reactor (BWR) channel, BWR fuel water tube, and Pressurized Water Reactor (PWR) guide tube as feasible applications for SiC composite. A program has been initiated to resolve some of the remaining issues and to generate physical property data to support the design of commercial fuel components.

  10. Silicon carbide composite for light water reactor fuel assembly applications

    Energy Technology Data Exchange (ETDEWEB)

    Yueh, Ken, E-mail: kyueh@epri.com [Fuel Reliability Program, EPRI, 1300 West WT Harris Blvd, Charlotte, NC 28262 (United States); Terrani, Kurt A., E-mail: terranika@ornl.gov [Fusion and Materials for Nuclear Systems Division, Oak Ridge National Laboratory, 1 Bethel Valley Rd. MS 6093, Oak Ridge, TN 37831 (United States)

    2014-05-01

    The feasibility of using SiC{sub f}–SiC{sub m} composites in light water reactor (LWR) fuel designs was evaluated. The evaluation was motivated by the desire to improve fuel performance under normal and accident conditions. The Fukushima accident once again highlighted the need for improved fuel materials that can maintain fuel integrity to higher temperatures for longer periods of time. The review identified many benefits as well as issues in using the material. Issues perceived as presenting the biggest challenges to the concept were identified to be flux gradient induced differential volumetric swelling, fragmentation and thermal shock resistance. The oxidation of silicon and its release into the coolant as silica has been identified as an issue because existing plant systems have limited ability for its removal. Detailed evaluation using available literature data and testing as part of this evaluation effort have eliminated most of the major concerns. The evaluation identified Boiling Water Reactor (BWR) channel, BWR fuel water tube, and Pressurized Water Reactor (PWR) guide tube as feasible applications for SiC composite. A program has been initiated to resolve some of the remaining issues and to generate physical property data to support the design of commercial fuel components.

  11. Multi-Applications Small Light Water Reactor - NERI Final Report

    Energy Technology Data Exchange (ETDEWEB)

    S. Michale Modro; James E. Fisher; Kevan D. Weaver; Jose N. Reyes, Jr.; John T. Groome; Pierre Babka; Thomas M. Carlson

    2003-12-01

    The Multi-Application Small Light Water Reactor (MASLWR) project was conducted under the auspices of the Nuclear Energy Research Initiative (NERI) of the U.S. Department of Energy (DOE). The primary project objectives were to develop the conceptual design for a safe and economic small, natural circulation light water reactor, to address the economic and safety attributes of the concept, and to demonstrate the technical feasibility by testing in an integral test facility. This report presents the results of the project. After an initial exploratory and evolutionary process, as documented in the October 2000 report, the project focused on developing a modular reactor design that consists of a self-contained assembly with a reactor vessel, steam generators, and containment. These modular units would be manufactured at a single centralized facility, transported by rail, road, and/or ship, and installed as a series of self-contained units. This approach also allows for staged construction of an NPP and ''pull and replace'' refueling and maintenance during each five-year refueling cycle.

  12. First-principles quantum-mechanical investigations: The role of water in catalytic conversion of furfural on Pd(111)

    Science.gov (United States)

    Xue, Wenhua; Borja, Miguel Gonzalez; Resasco, Daniel E.; Wang, Sanwu

    2015-03-01

    In the study of catalytic reactions of biomass, furfural conversion over metal catalysts with the presence of water has attracted wide attention. Recent experiments showed that the proportion of alcohol product from catalytic reactions of furfural conversion with palladium in the presence of water is significantly increased, when compared with other solvent including dioxane, decalin, and ethanol. We investigated the microscopic mechanism of the reactions based on first-principles quantum-mechanical calculations. We particularly identified the important role of water and the liquid/solid interface in furfural conversion. Our results provide atomic-scale details for the catalytic reactions. Supported by DOE (DE-SC0004600). This research used the supercomputer resources at NERSC, of XSEDE, at TACC, and at the Tandy Supercomputing Center.

  13. Fast atrazine photodegradation in water by pulsed light technology.

    Science.gov (United States)

    Baranda, Ana Beatriz; Barranco, Alejandro; de Marañón, Iñigo Martínez

    2012-03-01

    Pulsed light technology consists of a successive repetition of short duration (325μs) and high power flashes emitted by xenon lamps. These flashlamps radiate a broadband emission light (approx. 200-1000 nm) with a considerable amount of light in the short-wave UV spectrum. In the present work, this technology was tested as a new tool for the degradation of the herbicide atrazine in water. To evaluate the presence and evolution with time of this herbicide, as well as the formation of derivatives, liquid chromatography-mass spectrometry (electrospray ionization) ion trap operating in positive mode was used. The degradation process followed first-order kinetics. Fluences about 1.8-2.3 J/cm(2) induced 50% reduction of atrazine concentration independently of its initial concentration in the range 1-1000 μg/L. Remaining concentrations of atrazine, below the current legal limit for pesticides, were achieved in a short period of time. While atrazine was degraded, no chlorinated photoproducts were formed and ten dehalogenated derivatives were detected. The molecular structures for some of these derivatives could be suggested, being hydroxyatrazine the main photoproduct identified. The different formation profiles of photoproducts suggested that the degradation pathway may include several successive and competitive steps, with subsequent degradation processes taking part from the already formed degradation products. According to the degradation efficiency, the short treatment time and the lack of chloroderivatives, this new technology could be considered as an alternative for water treatment. Copyright © 2011 Elsevier Ltd. All rights reserved.

  14. A general strategy to fabricate ligand-free water-soluble up-conversion nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Li, Zhihua, E-mail: lizhihua2006@126.com [Department of Chemistry, Shandong Normal University, Jinan 250014 (China); State Key Lab of Crystal Materials, Shandong University, Jinan 250100 (China); Li, Ying; Wang, Yanan; Miao, Haixia; Du, Yu [Department of Chemistry, Shandong Normal University, Jinan 250014 (China); Liu, Hong [State Key Lab of Crystal Materials, Shandong University, Jinan 250100 (China)

    2014-11-15

    Highlights: • We notice that the coordination energy of Y{sup 3+} ions with oleate is less than the normal chemical bond, which can be broken by high power external force. • We report a simple and easily-operated physical method, ultrasonic separation, to remove the oleate ligand from the surface of NaYF{sub 4}:Yb{sup 3+}, Er{sup 3+}. • The oleate removing method can be applied to the converting of many nanomaterials from oil soluble to water soluble. - Abstract: It is a generally accepted method to synthesize the monodisperse NaYF{sub 4}:Yb{sup 3+}, Er{sup 3+} with uniform size and shape by using oleic acid (OA) as surfactant or solvent. However, the obtained oleate-capped up-conversion nanoparticles NaYF{sub 4}:Yb{sup 3+}, Er{sup 3+} (Ln-UCNPs, Ln = Yb{sup 3+}, Er{sup 3+}) have inherent hydrophobia properties, which should be processed by complicated post-treatments to render them water dispersible before used in biomedicine. Herein, we introduce a facile approach, ultrasonic separation, to obtain water-soluble and ligand-free Ln-UCNPs by analyzing the capping effect between Ln{sup 3+} and the carboxy group of oleate anions. After ultrasonic separation, the ligand-free of Ln-UCNPs disperse in water and ethanol easily, which are characterized by transmission electron microscopy (TEM), fourier transform infrared spectroscopy (FTIR), thermogravimetric analyses (TGA), nuclear magnetic resonance (NMR) and zeta potential. The experiments demonstrate that the present method is simple and effective to remove oleate layers from the surface of NaYF{sub 4}:Yb{sup 3+}, Er{sup 3+}, and worthy of being generalized.

  15. Fuel Summary Report: Shippingport Light Water Breeder Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Illum, D.B.; Olson, G.L.; McCardell, R.K.

    1999-01-01

    The Shippingport Light Water Breeder Reactor (LWBR) was a small water cooled, U-233/Th-232 cycle breeder reactor developed by the Pittsburgh Naval Reactors to improve utilization of the nation's nuclear fuel resources in light water reactors. The LWBR was operated at Shippingport Atomic Power Station (APS), which was a Department of Energy (DOE) (formerly Atomic Energy Commission)-owned reactor plant. Shippingport APS was the first large-scale, central-station nuclear power plant in the United States and the first plant of such size in the world operated solely to produce electric power. The Shippingport LWBR was operated successfully from 1977 to 1982 at the APS. During the five years of operation, the LWBR generated more than 29,000 effective full power hours (EFPH) of energy. After final shutdown, the 39 core modules of the LWBR were shipped to the Expended Core Facility (ECF) at Naval Reactors Facility at the Idaho National Engineering and Environmental Laboratory (INEEL). At ECF, 12 of the 39 modules were dismantled and about 1000 of more than 17,000 rods were removed from the modules of proof-of-breeding and fuel performance testing. Some of the removed rods were kept at ECF, some were sent to Argonne National Laboratory-West (ANL-W) in Idaho and some to ANL-East in Chicago for a variety of physical, chemical and radiological examinations. All rods and rod sections remaining after the experiments were shipped back to ECF, where modules and loose rods were repackaged in liners for dry storage. In a series of shipments, the liners were transported from ECF to Idaho Nuclear Technology Engineering Center (INTEC), formerly the Idaho Chemical Processing Plant (ICPP). The 47 liners containing the fully-rodded and partially-derodded core modules, the loose rods, and the rod scraps, are now stored in underground dry wells at CPP-749.

  16. Microbial community response to chlorine conversion in a chloraminated drinking water distribution system.

    Science.gov (United States)

    Wang, Hong; Proctor, Caitlin R; Edwards, Marc A; Pryor, Marsha; Santo Domingo, Jorge W; Ryu, Hodon; Camper, Anne K; Olson, Andrew; Pruden, Amy

    2014-09-16

    Temporary conversion to chlorine (i.e., "chlorine burn") is a common approach to controlling nitrification in chloraminated drinking water distribution systems, yet its effectiveness and mode(s) of action are not fully understood. This study characterized occurrence of nitrifying populations before, during and after a chlorine burn at 46 sites in a chloraminated distribution system with varying pipe materials and levels of observed nitrification. Quantitative polymerase chain reaction analysis of gene markers present in nitrifying populations indicated higher frequency of detection of ammonia oxidizing bacteria (AOB) (72% of samples) relative to ammonia oxidizing archaea (AOA) (28% of samples). Nitrospira nitrite oxidizing bacteria (NOB) were detected at 45% of samples, while presence of Nitrobacter NOB could not be confirmed at any of the samples. During the chlorine burn, the numbers of AOA, AOB, and Nitrospira greatly reduced (i.e., 0.8-2.4 log). However, rapid and continued regrowth of AOB and Nitrospira were observed along with nitrite production in the bulk water within four months after the chlorine burn, and nitrification outbreaks appeared to worsen 6-12 months later, even after adopting a twice annual burn program. Although high throughput sequencing of 16S rRNA genes revealed a distinct community shift and higher diversity index during the chlorine burn, it steadily returned towards a condition more similar to pre-burn than burn stage. Significant factors associated with nitrifier and microbial community composition included water age and sampling location type, but not pipe material. Overall, these results indicate that there is limited long-term effect of chlorine burns on nitrifying populations and the broader microbial community.

  17. Standard Guide for Benchmark Testing of Light Water Reactor Calculations

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2010-01-01

    1.1 This guide covers general approaches for benchmarking neutron transport calculations in light water reactor systems. A companion guide (Guide E2005) covers use of benchmark fields for testing neutron transport calculations and cross sections in well controlled environments. This guide covers experimental benchmarking of neutron fluence calculations (or calculations of other exposure parameters such as dpa) in more complex geometries relevant to reactor surveillance. Particular sections of the guide discuss: the use of well-characterized benchmark neutron fields to provide an indication of the accuracy of the calculational methods and nuclear data when applied to typical cases; and the use of plant specific measurements to indicate bias in individual plant calculations. Use of these two benchmark techniques will serve to limit plant-specific calculational uncertainty, and, when combined with analytical uncertainty estimates for the calculations, will provide uncertainty estimates for reactor fluences with ...

  18. Commercial Light Water Reactor Tritium Extraction Facility Geotechnical Summary Report

    Energy Technology Data Exchange (ETDEWEB)

    Lewis, M R

    2000-01-11

    A geotechnical investigation program has been completed for the Circulating Light Water Reactor - Tritium Extraction Facility (CLWR-TEF) at the Savannah River Site (SRS). The program consisted of reviewing previous geotechnical and geologic data and reports, performing subsurface field exploration, field and laboratory testing and geologic and engineering analyses. The purpose of this investigation was to characterize the subsurface conditions for the CLWR-TEF in terms of subsurface stratigraphy and engineering properties for design and to perform selected engineering analyses. The objectives of the evaluation were to establish site-specific geologic conditions, obtain representative engineering properties of the subsurface and potential fill materials, evaluate the lateral and vertical extent of any soft zones encountered, and perform engineering analyses for slope stability, bearing capacity and settlement, and liquefaction potential. In addition, provide general recommendations for construction and earthwork.

  19. Non-linear analysis in Light Water Reactor design

    Energy Technology Data Exchange (ETDEWEB)

    Rashid, Y.R.; Sharabi, M.N.; Nickell, R.E.; Esztergar, E.P.; Jones, J.W.

    1980-03-01

    The results obtained from a scoping study sponsored by the US Department of Energy (DOE) under the Light Water Reactor (LWR) Safety Technology Program at Sandia National Laboratories are presented. Basically, this project calls for the examination of the hypothesis that the use of nonlinear analysis methods in the design of LWR systems and components of interest include such items as: the reactor vessel, vessel internals, nozzles and penetrations, component support structures, and containment structures. Piping systems are excluded because they are being addressed by a separate study. Essentially, the findings were that nonlinear analysis methods are beneficial to LWR design from a technical point of view. However, the costs needed to implement these methods are the roadblock to readily adopting them. In this sense, a cost-benefit type of analysis must be made on the various topics identified by these studies and priorities must be established. This document is the complete report by ANATECH International Corporation.

  20. Materials Inventory Database for the Light Water Reactor Sustainability Program

    Energy Technology Data Exchange (ETDEWEB)

    Kazi Ahmed; Shannon M. Bragg-Sitton

    2013-08-01

    Scientific research involves the purchasing, processing, characterization, and fabrication of many sample materials. The history of such materials can become complicated over their lifetime – materials might be cut into pieces or moved to various storage locations, for example. A database with built-in functions to track these kinds of processes facilitates well-organized research. The Material Inventory Database Accounting System (MIDAS) is an easy-to-use tracking and reference system for such items. The Light Water Reactor Sustainability Program (LWRS), which seeks to advance the long-term reliability and productivity of existing nuclear reactors in the United States through multiple research pathways, proposed MIDAS as an efficient way to organize and track all items used in its research. The database software ensures traceability of all items used in research using built-in functions which can emulate actions on tracked items – fabrication, processing, splitting, and more – by performing operations on the data. MIDAS can recover and display the complete history of any item as a simple report. To ensure the database functions suitably for the organization of research, it was developed alongside a specific experiment to test accident tolerant nuclear fuel cladding under the LWRS Advanced Light Water Reactor Nuclear Fuels Pathway. MIDAS kept track of materials used in this experiment from receipt at the laboratory through all processes, test conduct and, ultimately, post-test analysis. By the end of this process, the database proved to be right tool for this program. The database software will help LWRS more efficiently conduct research experiments, from simple characterization tests to in-reactor experiments. Furthermore, MIDAS is a universal tool that any other research team could use to organize their material inventory.

  1. Shape-Controlled Synthesis of High-Quality Cu7 S4 Nanocrystals for Efficient Light-Induced Water Evaporation.

    Science.gov (United States)

    Zhang, Changbo; Yan, Cong; Xue, Zhenjie; Yu, Wei; Xie, Yinde; Wang, Tie

    2016-10-01

    Copper sulfides (Cu2-x S), are a novel kind of photothermal material exhibiting significant photothermal conversion efficiency, making them very attractive in various energy conversion related devices. Preparing high quality uniform Cu2-x S nanocrystals (NCs) is a top priority for further energy-and sustainability relevant nanodevices. Here, a shape-controlled high quality Cu7 S4 NCs synthesis strategy is reported using sulfur in 1-octadecene as precursor by varying the heating temperature, as well as its forming mechanism. The performance of the Cu7 S4 NCs is further explored for light-driven water evaporation without the need of heating the bulk liquid to the boiling point, and the results suggest that as-synthesized highly monodisperse NCs perform higher evaporation rate than polydisperse NCs under the identical morphology. Furthermore, disk-like NCs exhibit higher water evaporation rate than spherical NCs. The water evaporation rate can be further enhanced by assembling the organic phase Cu7 S4 NCs into a dense film on the aqueous solution surface. The maximum photothermal conversion efficiency is as high as 77.1%.

  2. An efficient luminescence conversion LED for white light emission, fabricated using a commercial InGaN LED and a 1,8-naphthalimide derivative

    Science.gov (United States)

    Kim, Hyun-Jeong; Jin, Ji-Young; Lee, Youn-Sik; Lee, Sang-Hee; Hong, Chang-Hee

    2006-11-01

    A highly efficient luminescence conversion light emitting diode (LUCO LED) was fabricated, using a commercial InGaN LED (460 nm) and 4- N, N-diphenyl-9-(4- tert-butylphenyl)-1,8-naphthalimide (DBN), dispersed in epoxy as the primary light source and LUCO material, respectively. The emission of very bright white light was observed at 20 mA, with CIE chromaticity coordinates of (0.32, 0.33) and conversion efficiency of 82%. The luminescent output of the LUCO LED decreased rapidly, but when the LUCO LED was prepared using DNB dispersed in poly(methyl methacrylate), it only decreased to about 67% of the initial value after 19 days of continual operation at 200 mA.

  3. The use of PRA in the development of ALWR (advanced light water reactor) design requirements. [Advanced Light Water Reactors

    Energy Technology Data Exchange (ETDEWEB)

    Summitt, R.L. (Safety and Reliability Optimization Services, Inc., Knoxville, TN (USA)); Additon, S.L. (TENERA, L.P., Bethesda, MD (USA)); Pasedag, W.F. (USDOE, Washington, DC (USA))

    1989-01-01

    The current hiatus in nuclear power plant orders provides an opportunity for the development of advanced light water reactor (ALWR) design concepts and regulatory requirements which incorporate the insights gained from the application of the probabilistic risk assessment. The US Department of Energy is assisting the Electric Power Research Institute (EPRI) in the incorporation of PRA insights into the specification of the utility requirements, and reactor vendors in support of the conceptual design of safety systems, for such advanced plants. This paper reviews the applications of PRA methods in this development of specifications for, and the design of simplified, rugged ALWRs with a significantly improved risk profile. Specific examples of the impact of utilizing published PRA insights, construction and use of functional PRA models, and feedback of PRA experience into the specification of the key assumptions and groundrules for ALWR PRAs are presented. 13 refs., 3 tabs.

  4. A two-step photoexcitation system for photocatalytic water splitting into hydrogen and oxygen under visible light irradiation

    Science.gov (United States)

    Abe, Ryu

    2011-10-01

    The developments of water-splitting systems that can efficiently use visible light have been a major challenge for many years in order to realize efficient conversion of solar light. We have developed a new type of photocatalysis system that can split water into H2 and O2 under visible light irradiation, which was inspired by the two-step photoexcitation (Zscheme) mechanism of natural photosynthesis in green plants. In this system, the water splitting reaction is broken up into two stages: one for H2 evolution and the other for O2 evolution; these are combined by using a shuttle redox couple (Red/Ox) in the solution. The introduction of a Z-scheme mechanism reduces the energy required to drive each photocatalysis process, extending the usable wavelengths significantly (~460 nm for H2 evolution and ~600 nm for O2evolution) from that in conventional water splitting systems (~460 nm) based on one-step photoexcitation in single semiconductor material.

  5. Measurements of the speed of light in water using Foucault's technique

    Science.gov (United States)

    Brody, Jed; Griffin, Laura; Segre, Phil

    2010-06-01

    We describe how to modify an existing speed-of-light apparatus to measure the speed of light in water. We derive the necessary formulas to account for refraction and light's passage through both water and air. We obtain (3.00±0.09)×108 m/s for the speed of light in air and (2.1±0.1)×108 m/s for the speed of the light in water. Both results are within 7% of established values.

  6. Offshore conversion of associated gas to synthetic crude oil: An economic option for deep water and marginal fields

    Energy Technology Data Exchange (ETDEWEB)

    Antia, D.D.J.; Seddon, D.

    1995-12-31

    A low cost modular Fischer Tropsch gas conversion approach which can add value to associated gas in both deep water and marginal fields is described. The process is suitable for location on vessels (FPSO`s), jackups, platforms and semisubmersibles. It can economically convert >1 to >200 MMCF/D to syncrude. The modules can be used to: Strip value from gas prior to injection; Remove a reinjection or flaring requirement; Reduce carbon dioxide emissions from the field. Conversion ratios depend on the catalyst and process configuration used. They range from 70-->170 Bbls/MMCF.

  7. Evaluation of the Effect of Porcelain Laminate Thickness on Degree of Conversion of Light Cure and Dual Cure Resin Cements Using FTIR

    Science.gov (United States)

    Hoorizad Ganjkar, Maryam; Heshmat, Haleh; Hassan Ahangari, Reza

    2017-01-01

    Statement of the Problem: Increasing the thickness of the veneering porcelain may affect the polymerization of resin cements. Incomplete polymerization of resin cements can lead to compromised quality of restoration and decrease the longevity of indirect restorations. Purpose: This study sought to assess the effect of IPS Empress porcelain thickness on the degree of conversion of light-cure and dual-cure resin cements using Fourier transform infrared spectroscopy. Materials and Method: In this experimental study, IPS Empress porcelain discs (A2 shade) with 10mm diameter and 0.5, 1 and 1.5 mm thicknesses were fabricated. Choice2 (Bisco, USA) and Nexus3 (Kerr, USA) resin cements were light cured through the three porcelain thicknesses in two groups of 3 samples using a LED light-curing unit (LEDemetron II; Kerr, USA). The control group samples were cured individually with no porcelain disc. The degree of conversion of resin cements was determined using FTIR (Bruker; Equinox55, Germany). The data were analyzed using Dunn’s test. Results: The degree of conversion (in percent) beneath the 0.5, 1.5 and 2 mm thicknesses of IPS Empress was 68.67±0.88, 71.06±0.94 and 72.51±0.41 for Choice2 resin cement and 69.60±2.12, 69.64±1.63 and 69.24±2.12 for Nexus3, respectively. Porcelain thickness and type of resin cement had no significant effect on degree of conversion (p≥ 0.05). Conclusion: It seems that increasing the porcelain thickness by up to 1.5 mm has no adverse effect on degree of conversion of both dual cure and light cure resin cements evaluated in this study. PMID:28280757

  8. High Photon-to-Current Conversion in Solar Cells Based on Light-Absorbing Silver Bismuth Iodide.

    Science.gov (United States)

    Zhu, Huimin; Pan, Mingao; Johansson, Malin B; Johansson, Erik M J

    2017-06-22

    Here, a lead-free silver bismuth iodide (AgI/BiI3 ) with a crystal structure with space group R3‾ m is investigated for use in solar cells. Devices based on the silver bismuth iodide deposited from solution on top of TiO2 and the conducting polymer poly(3-hexylthiophene-2,5-diyl) (P3HT) as a hole-transport layer are prepared and the photovoltaic performance is very promising with a power conversion efficiency over 2 %, which is higher than the performance of previously reported bismuth-halide materials for solar cells. Photocurrent generation is observed between 350 and 700 nm, and the maximum external quantum efficiency is around 45 %. The results are compared to solar cells based on the previously reported material AgBi2 I7 , and we observe a clearly higher performance for the devices with the new silver and bismuth iodides composition and different crystal structure. The X-ray diffraction spectrum of the most efficient silver bismuth iodide material shows a hexagonal crystal structure with space group R3‾ m, and from the light absorption spectrum we obtain an indirect band gap energy of 1.62 eV and a direct band gap energy of 1.85 eV. This report shows the possibility for finding new structures of metal-halides efficient in solar cells and points out new directions for further exploration of lead-free metal-halide solar cells. © 2017 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA.

  9. Graphene oxide/α-Bi(2)O(3) composites for visible-light photocatalysis, chemical catalysis, and solar energy conversion.

    Science.gov (United States)

    Som, Tirtha; Troppenz, Gerald V; Wendt, R Robert; Wollgarten, Markus; Rappich, Jörg; Emmerling, Franziska; Rademann, Klaus

    2014-03-01

    The growing challenges of environmental purification by solar photocatalysis, precious-metal-free catalysis, and photocurrent generation in photovoltaic cells receive the utmost global attention. Here we demonstrate a one-pot, green chemical synthesis of a new stable heterostructured, ecofriendly, multifunctional microcomposite that consists of α-Bi2 O3 microneedles intercalated with anchored graphene oxide (GO) microsheets (1.0 wt %) for the above-mentioned applications on a large economical scale. The bare α-Bi2 O3 microneedles display two times better photocatalytic activities than commercial TiO2 (Degussa-P25), whereas the GO-hybridized composite exhibits approximately four to six times enhanced photocatalytic activities than the neat TiO2 photocatalyst in the degradation of colored aromatic organic dyes (crystal violet and rhodamine 6G) under visible-light irradiation (300 W tungsten lamp). The highly efficient activity is associated with the strong surface adsorption ability of GO for aromatic dye molecules, the high carrier acceptability, and the efficient electron-hole pair separation in Bi2 O3 by individual adjoining GO sheets. The introduction of Ag nanoparticles (2.0 wt %) further enhances the photocatalytic performance of the composite over eightfold because of a plasmon-induced electron-transfer process from Ag nanoparticles through the GO sheets into the conduction band of Bi2 O3 . The new composites are also catalytically active and catalyze the reduction of 4-nitrophenol to 4-aminophenol in the presence of borohydride ions. Photoanodes assembled from GO/α-Bi2 O3 and Ag/GO/α-Bi2 O3 composites display an improved photocurrent response (power conversion efficiency ∼20 % higher) over those prepared without GO in dye-sensitized solar cells. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Application of fully ceramic microencapsulated fuels in light water reactors

    Energy Technology Data Exchange (ETDEWEB)

    Gentry, C.; George, N.; Maldonado, I. [Dept. of Nuclear Engineering, Univ. of Tennessee-Knoxville, Knoxville, TN 37996-2300 (United States); Godfrey, A.; Terrani, K.; Gehin, J. [Oak Ridge National Laboratory, Oak Ridge, TN 37831 (United States)

    2012-07-01

    This study performs a preliminary evaluation of the feasibility of incorporation of Fully Ceramic Microencapsulated (FCM) fuels in light water reactors (LWRs). In particular, pin cell, lattice, and full core analyses are carried out on FCM fuel in a pressurized water reactor (PWR). Using uranium-based fuel and Pu/Np-based fuel in TRistructural isotropic (TRISO) particle form, each fuel design was examined using the SCALE 6.1 analytical suite. In regards to the uranium-based fuel, pin cell calculations were used to determine which fuel material performed best when implemented in the fuel kernel as well as the size of the kernel and surrounding particle layers. The higher fissile material density of uranium mononitride (UN) proved to be favorable, while the parametric studies showed that the FCM particle fuel design with 19.75% enrichment would need roughly 12% additional fissile material in comparison to that of a standard UO{sub 2} rod in order to match the lifetime of an 18-month PWR cycle. As part of the fuel assembly design evaluations, fresh feed lattices were modeled to analyze the within-assembly pin power peaking. Also, a 'color-set' array of assemblies was constructed to evaluate power peaking and power sharing between a once-burned and a fresh feed assembly. In regards to the Pu/Np-based fuel, lattice calculations were performed to determine an optimal lattice design based on reactivity behavior, pin power peaking, and isotopic content. After obtaining a satisfactory lattice design, the feasibility of core designs fully loaded with Pu/Np FCM lattices was demonstrated using the NESTLE three-dimensional core simulator. (authors)

  11. Application of Fully Ceramic Microencapsulated Fuels in Light Water Reactors

    Energy Technology Data Exchange (ETDEWEB)

    Gentry, Cole A [ORNL; George, Nathan M [ORNL; Maldonado, G Ivan [ORNL; Godfrey, Andrew T [ORNL; Terrani, Kurt A [ORNL; Gehin, Jess C [ORNL

    2012-01-01

    This study aims to perform a preliminary evaluation of the feasibility of incorporation of Fully Ceramic Microencapsulated (FCM) fuels in Light Water Reactors (LWRs). In particular pin cell, lattice, and full core analyses are carried out on FCM fuel in a pressurized water reactor. Using uranium-based fuel and transuranic (TRU) based fuel in TRistructural ISOtropic (TRISO) particle form, each fuel design was examined using the SCALE 6.1 analytical suite. In regards to the uranium-based fuel, pin cell calculations were used to determine which fuel material performed best when implemented in the fuel kernel as well as the size of the kernel and surrounding particle layers. The higher physical density of uranium mononitride (UN) proved to be favorable, while the parametric studies showed that the FCM particle fuel design would need roughly 12% additional fissile material in comparison to that of a standard UO2 rod in order to match the lifetime of an 18-month PWR cycle. As part of the fuel assembly design evaluations, fresh feed lattices were modeled to analyze the within-assembly pin power peaking. Also, a color-set array of assemblies was constructed to evaluate power peaking and power sharing between a once-burned and a fresh feed assembly. In regards to the TRU based fuel, lattice calculations were performed to determine an optimal lattice design based on reactivity behavior, pin power peaking, and isotopic content. After obtaining a satisfactory lattice design, feasibility of core designs fully loaded with TRU FCM lattices was demonstrated using the NESTLE three-dimensional core simulator.

  12. Universal Long-Range Nanometric Bending of Water by Light

    Science.gov (United States)

    Verma, Gopal; Singh, Kamal P.

    2015-10-01

    Resolving mechanical effects of light on fluids has fundamental importance with wide applications. Most experiments to date on optofluidic interface deformation exploited radiation forces exerted by normally incident lasers. However, the intriguing effects of photon momentum for any configuration, including the unique total internal reflection regime, where an evanescent wave leaks above the interface, remain largely unexplored. A major difficulty in resolving nanomechanical effects has been the lack of a sensitive detection technique. Here, we devise a simple setup whereby a probe laser produces high-contrast Newton-ring-like fringes from a sessile water drop. The mechanical action of the photon momentum of a pump beam modulates the fringes, thus allowing us to perform a direct noninvasive measurement of a nanometric bulge with sub-5-nm precision. Remarkably, a <10 nm difference in the height of the bulge due to different laser polarizations and nonlinear enhancement in the bulge near total internal reflection is isolated. In addition, the nanometric bulge is shown to extend far longer, 100 times beyond the pump spot. Our high precision data validate the century-old Minkowski theory for a general angle and offer potential for novel optofluidic devices and noncontact nanomanipulation strategies.

  13. Impact of inflow transport approximation on light water reactor analysis

    Science.gov (United States)

    Choi, Sooyoung; Smith, Kord; Lee, Hyun Chul; Lee, Deokjung

    2015-10-01

    The impact of the inflow transport approximation on light water reactor analysis is investigated, and it is verified that the inflow transport approximation significantly improves the accuracy of the transport and transport/diffusion solutions. A methodology for an inflow transport approximation is implemented in order to generate an accurate transport cross section. The inflow transport approximation is compared to the conventional methods, which are the consistent-PN and the outflow transport approximations. The three transport approximations are implemented in the lattice physics code STREAM, and verification is performed for various verification problems in order to investigate their effects and accuracy. From the verification, it is noted that the consistent-PN and the outflow transport approximations cause significant error in calculating the eigenvalue and the power distribution. The inflow transport approximation shows very accurate and precise results for the verification problems. The inflow transport approximation shows significant improvements not only for the high leakage problem but also for practical large core problem analyses.

  14. Self-similar hydrodynamic flow in the laser light to x-ray conversion layer of a laser-heated solid

    Energy Technology Data Exchange (ETDEWEB)

    Oparin, A.M.; Sigel, R. [Max-Planck-Institut fuer Quantenoptik, D-85748 Garching (Germany)

    1995-08-01

    Intense short-wavelength laser light may be converted into thermal soft x rays in the dense plasma formed by irradiation of a solid high-{ital Z} material. Under certain conditions, the hydrodynamic flow in the conversion layer is self-similar, and profiles of the hydrodynamic variables may be readily calculated by solving the appropriate hydrodynamic equations. It is found that the structure of the conversion layer depends on the type of equilibrium that determines the atomic physics processes of radiation emission. Varying the conditions between the limits of local thermodynamic equilibrium (LTE) and coronal equilibrium (CE) shows, that in the latter case, the radiation comes mainly from a thin layer in the dense part of the conversion layer. {copyright} {ital 1995} {ital American} {ital Institute} {ital of} {ital Physics}.

  15. Water cooled breeder program summary report (LWBR (Light Water Breeder Reactor) development program)

    Energy Technology Data Exchange (ETDEWEB)

    1987-10-01

    The purpose of the Department of Energy Water Cooled Breeder Program was to demonstrate pratical breeding in a uranium-233/thorium fueled core while producing electrical energy in a commercial water reactor generating station. A demonstration Light Water Breeder Reactor (LWBR) was successfully operated for more than 29,000 effective full power hours in the Shippingport Atomic Power Station. The reactor operated with an availability factor of 76% and had a gross electrical output of 2,128,943,470 kilowatt hours. Following operation, the expended core was examined and no evidence of any fuel element defects was found. Nondestructive assay of 524 fuel rods determined that 1.39 percent more fissile fuel was present at the end of core life than at the beginning, proving that breeding had occurred. This demonstrates the existence of a vast source of electrical energy using plentiful domestic thorium potentially capable of supplying the entire national need for many centuries. To build on the successful design and operation of the Shippingport Breeder Core and to provide the technology to implement this concept, several reactor designs of large breeders and prebreeders were developed for commercial-sized plants of 900--1000 Mw(e) net. This report summarizes the Water Cooled Breeder Program from its inception in 1965 to its completion in 1987. Four hundred thirty-six technical reports are referenced which document the work conducted as part of this program. This work demonstrated that the Light Water Breeder Reactor is a viable alternative as a PWR replacement in the next generation of nuclear reactors. This transition would only require a minimum of change in design and fabrication of the reactor and operation of the plant.

  16. Improving Visible Light-Absorptivity and Photoelectric Conversion Efficiency of a TiO2 Nanotube Anode Film by Sensitization with Bi2O3 Nanoparticles

    Directory of Open Access Journals (Sweden)

    Menglei Chang

    2017-05-01

    Full Text Available This study presents a novel visible light-active TiO2 nanotube anode film by sensitization with Bi2O3 nanoparticles. The uniform incorporation of Bi2O3 contributes to largely enhancing the solar light absorption and photoelectric conversion efficiency of TiO2 nanotubes. Due to the energy level difference between Bi2O3 and TiO2, the built-in electric field is suggested to be formed in the Bi2O3 sensitized TiO2 hybrid, which effectively separates the photo-generated electron-hole pairs and hence improves the photocatalytic activity. It is also found that the photoelectric conversion efficiency of Bi2O3 sensitized TiO2 nanotubes is not in direct proportion with the content of the sensitizer, Bi2O3, which should be carefully controlled to realize excellent photoelectrical properties. With a narrower energy band gap relative to TiO2, the sensitizer Bi2O3 can efficiently harvest the solar energy to generate electrons and holes, while TiO2 collects and transports the charge carriers. The new-type visible light-sensitive photocatalyst presented in this paper will shed light on sensitizing many other wide-band-gap semiconductors for improving solar photocatalysis, and on understanding the visible light-driven photocatalysis through narrow-band-gap semiconductor coupling.

  17. Direct catalytic conversion of methane and light hydrocarbon gases. Final report, October 1, 1986--July 31, 1989

    Energy Technology Data Exchange (ETDEWEB)

    Wilson, R.B. Jr.; Posin, B.M.; Chan, Yee-Wai

    1995-06-01

    This project explored conversion of methane to useful products by two techniques that do not involve oxidative coupling. The first approach was direct catalytic dehydrocoupling of methane to give hydrocarbons and hydrogen. The second approach was oxidation of methane to methanol by using heterogenized versions of catalysts that were developed as homogeneous models of cytochrome-P450, an enzyme that actively hydroxylates hydrocarbons by using molecular oxygen. Two possibilities exist for dehydrocoupling of methane to higher hydrocarbons: The first, oxidative coupling to ethane/ethylene and water, is the subject of intense current interest. Nonoxidative coupling to higher hydrocarbons and hydrogen is endothermic, but in the absence of coke formation the theoretical thermodynamic equilibrium yield of hydrocarbons varies from 25% at 827{degrees}C to 65% at 1100{degrees}C (at atmospheric pressure). In this project we synthesized novel, highly dispersed metal catalysts by attaching metal clusters to inorganic supports. The second approach mimics microbial metabolism of methane to produce methanol. The methane mono-oxygenase enzyme responsible for the oxidation of methane to methanol in biological systems has exceptional selectivity and very good rates. Enzyme mimics are systems that function as the enzymes do but overcome the problems of slow rates and poor stability. Most of that effort has focused on mimics of cytochrome P-450, which is a very active selective oxidation enzyme and has a metalloporphyrin at the active site. The interest in nonporphyrin mimics coincides with the interest in methane mono-oxygenase, whose active site has been identified as a {mu}-oxo dinuclear iron complex.We employed mimics of cytochrome P-450, heterogenized to provide additional stability. The oxidation of methane with molecular oxygen was investigated in a fixed-bed, down-flow reactor with various anchored metal phthalocyanines (PC) and porphyrins (TPP) as the catalysts.

  18. 76 FR 18753 - City of Springfield, Illinois, City Water, Light and Power; Notice of Filing

    Science.gov (United States)

    2011-04-05

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission City of Springfield, Illinois, City Water, Light and Power; Notice of Filing Take notice that on March 24, 2011, The City of Springfield, Illinois, City Water, Light and...

  19. Technology Implementation Plan. Fully Ceramic Microencapsulated Fuel for Commercial Light Water Reactor Application

    Energy Technology Data Exchange (ETDEWEB)

    Snead, Lance Lewis [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Terrani, Kurt A. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Powers, Jeffrey J. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Worrall, Andrew [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Robb, Kevin R. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Snead, Mary A. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2015-04-01

    This report is an overview of the implementation plan for ORNL's fully ceramic microencapsulated (FCM) light water reactor fuel. The fully ceramic microencapsulated fuel consists of tristructural isotropic (TRISO) particles embedded inside a fully dense SiC matrix and is intended for utilization in commercial light water reactor application.

  20. Ultrafast spectroscopy studies on the mechanism of electron transfer and energy conversion in the isolated pseudo ginseng, water hyacinth and spinach chloroplasts

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The spectroscopy characteristics and the fluorescence lifetime for the chloroplasts isolated from the pseudo ginseng, water hyacinth and spinach plant leaves have been studied by absorption spectra, low temperature steady-state fluorescence spectroscopy and single photon counting measurement under the same conditions and by the same methods. The similarity of the absorption spectra for the chloroplasts at room temperature suggests that different plants can efficiently absorb light of the same wavelength. The fluorescence decays in PS II measured at the natural QA state for the chloroplasts have been fitted by a three-exponential kinetic model. The three fluorescence lifetimes are 30, 274 and 805 ps for the pseudo ginseng chloroplast; 138, 521 and 1494 ps for the water hyacinth chloroplast; 197, 465 and 1459 ps for the spinach chloroplast, respectively. The slow lifetime fluorescence component is assigned to a collection of associated light harvesting Chl a/b proteins, the fast lifetime component to the reaction center of PS II and the middle lifetime component to the delay fluorescence of recombination of and Pheo-. The excitation energy conversion efficiency (η) in PS II RC is defined and calculated on the basis of the 20 ps electron transfer time constant model, 60%, 87% and 91% for the pseudo ginseng, water hyacinth and spinach chloroplasts, respectively. This interesting result is in unconformity with what is assumed to be 100% efficiency in PS II RC. Our result in this work stands in line with the 20 ps electron transfer time constant in PS II rather sound and the water hyacinth plant grows slower than the spinach plant does as envisaged on the efficiency. But, our results predict that those plants can perform highly efficient transfer of photo-excitation energy from the light-harvesting pigment system to the reaction center (closely to 100%). The conclusion contained in this paper reveals the plant growth characteristics expressed in the primary processes of

  1. Revised accident source terms for light-water reactors

    Energy Technology Data Exchange (ETDEWEB)

    Soffer, L. [Nuclear Regulatory Commission, Washington, DC (United States)

    1995-02-01

    This paper presents revised accident source terms for light-water reactors incorporating the severe accident research insights gained in this area over the last 15 years. Current LWR reactor accident source terms used for licensing date from 1962 and are contained in Regulatory Guides 1.3 and 1.4. These specify that 100% of the core inventory of noble gases and 25% of the iodine fission products are assumed to be instantaneously available for release from the containment. The chemical form of the iodine fission products is also assumed to be predominantly elemental iodine. These assumptions have strongly affected present nuclear air cleaning requirements by emphasizing rapid actuation of spray systems and filtration systems optimized to retain elemental iodine. A proposed revision of reactor accident source terms and some im implications for nuclear air cleaning requirements was presented at the 22nd DOE/NRC Nuclear Air Cleaning Conference. A draft report was issued by the NRC for comment in July 1992. Extensive comments were received, with the most significant comments involving (a) release fractions for both volatile and non-volatile species in the early in-vessel release phase, (b) gap release fractions of the noble gases, iodine and cesium, and (c) the timing and duration for the release phases. The final source term report is expected to be issued in late 1994. Although the revised source terms are intended primarily for future plants, current nuclear power plants may request use of revised accident source term insights as well in licensing. This paper emphasizes additional information obtained since the 22nd Conference, including studies on fission product removal mechanisms, results obtained from improved severe accident code calculations and resolution of major comments, and their impact upon the revised accident source terms. Revised accident source terms for both BWRS and PWRS are presented.

  2. Light Water Reactor Sustainability Program Integrated Program Plan

    Energy Technology Data Exchange (ETDEWEB)

    Kathryn McCarthy; Jeremy Busby; Bruce Hallbert; Shannon Bragg-Sitton; Curtis Smith; Cathy Barnard

    2013-04-01

    Nuclear power has safely, reliably, and economically contributed almost 20% of electrical generation in the United States over the past two decades. It remains the single largest contributor (more than 70%) of non-greenhouse-gas-emitting electric power generation in the United States. Domestic demand for electrical energy is expected to experience a 31% growth from 2009 to 2035. At the same time, most of the currently operating nuclear power plants will begin reaching the end of their initial 20-year extension to their original 40-year operating license for a total of 60 years of operation. Figure E-1 shows projected nuclear energy contribution to the domestic generating capacity. If current operating nuclear power plants do not operate beyond 60 years, the total fraction of generated electrical energy from nuclear power will begin to decline—even with the expected addition of new nuclear generating capacity. The oldest commercial plants in the United States reached their 40th anniversary in 2009. The U.S. Department of Energy Office of Nuclear Energy’s Research and Development Roadmap (Nuclear Energy Roadmap) organizes its activities around four objectives that ensure nuclear energy remains a compelling and viable energy option for the United States. The four objectives are as follows: (1) develop technologies and other solutions that can improve the reliability, sustain the safety, and extend the life of the current reactors; (2) develop improvements in the affordability of new reactors to enable nuclear energy to help meet the Administration’s energy security and climate change goals; (3) develop sustainable nuclear fuel cycles; and (4) understand and minimize the risks of nuclear proliferation and terrorism. The Light Water Reactor Sustainability (LWRS) Program is the primary programmatic activity that addresses Objective 1. This document summarizes the LWRS Program’s plans.

  3. Light Water Reactor Sustainability Program Integrated Program Plan

    Energy Technology Data Exchange (ETDEWEB)

    George Griffith; Robert Youngblood; Jeremy Busby; Bruce Hallbert; Cathy Barnard; Kathryn McCarthy

    2012-01-01

    Nuclear power has safely, reliably, and economically contributed almost 20% of electrical generation in the United States over the past two decades. It remains the single largest contributor (more than 70%) of non-greenhouse-gas-emitting electric power generation in the United States. Domestic demand for electrical energy is expected to experience a 31% growth from 2009 to 2035. At the same time, most of the currently operating nuclear power plants will begin reaching the end of their initial 20-year extension to their original 40-year operating license for a total of 60 years of operation. Figure E-1 shows projected nuclear energy contribution to the domestic generating capacity. If current operating nuclear power plants do not operate beyond 60 years, the total fraction of generated electrical energy from nuclear power will begin to decline - even with the expected addition of new nuclear generating capacity. The oldest commercial plants in the United States reached their 40th anniversary in 2009. The U.S. Department of Energy Office of Nuclear Energy's Research and Development Roadmap (Nuclear Energy Roadmap) organizes its activities around four objectives that ensure nuclear energy remains a compelling and viable energy option for the United States. The four objectives are as follows: (1) develop technologies and other solutions that can improve the reliability, sustain the safety, and extend the life of the current reactors; (2) develop improvements in the affordability of new reactors to enable nuclear energy to help meet the Administration's energy security and climate change goals; (3) develop sustainable nuclear fuel cycles; and (4) understand and minimize the risks of nuclear proliferation and terrorism. The Light Water Reactor Sustainability (LWRS) Program is the primary programmatic activity that addresses Objective 1. This document summarizes the LWRS Program's plans.

  4. Light Water Reactor Sustainability Program Integrated Program Plan

    Energy Technology Data Exchange (ETDEWEB)

    McCarthy, Kathryn A. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Busby, Jeremy [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Hallbert, Bruce [Idaho National Lab. (INL), Idaho Falls, ID (United States); Bragg-Sitton, Shannon [Idaho National Lab. (INL), Idaho Falls, ID (United States); Smith, Curtis [Idaho National Lab. (INL), Idaho Falls, ID (United States); Barnard, Cathy [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2014-04-01

    Nuclear power has safely, reliably, and economically contributed almost 20% of electrical generation in the United States over the past two decades. It remains the single largest contributor (more than 70%) of non-greenhouse-gas-emitting electric power generation in the United States. Domestic demand for electrical energy is expected to experience a 31% growth from 2009 to 2035. At the same time, most of the currently operating nuclear power plants will begin reaching the end of their initial 20-year extension to their original 40-year operating license for a total of 60 years of operation. Figure E-1 shows projected nuclear energy contribution to the domestic generating capacity. If current operating nuclear power plants do not operate beyond 60 years, the total fraction of generated electrical energy from nuclear power will begin to decline—even with the expected addition of new nuclear generating capacity. The oldest commercial plants in the United States reached their 40th anniversary in 2009. The U.S. Department of Energy Office of Nuclear Energy’s Research and Development Roadmap (Nuclear Energy Roadmap) organizes its activities around four objectives that ensure nuclear energy remains a compelling and viable energy option for the United States. The four objectives are as follows: (1) develop technologies and other solutions that can improve the reliability, sustain the safety, and extend the life of the current reactors; (2) develop improvements in the affordability of new reactors to enable nuclear energy to help meet the Administration’s energy security and climate change goals; (3) develop sustainable nuclear fuel cycles; and (4) understand and minimize the risks of nuclear proliferation and terrorism. The Light Water Reactor Sustainability (LWRS) Program is the primary programmatic activity that addresses Objective 1. This document summarizes the LWRS Program’s plans.

  5. Experimental and theoretical studies on visible light attenuation in water

    CERN Document Server

    Simpson, A; Cho, H J; Liu, H

    2014-01-01

    In this study we describe lab experiments on determining the above water reflectance Rrs coefficient, and the water attenuation coefficient Kd for fresh water. Different types of screens (totally absorbent, gray, etc.) were submerged in water (0-0.6 m) and illuminated from outside. The spectral density of the water leaving radiance was measured for different depths. The results were ran by a code which took into account the geometry of the incident irradiation, the geometry of the screen under water, and boundary conditions at the water surface provided by the radiation transfer theory. From the experimental data and our model we obtain the spectral distribution of the attenuation coefficient for fresh water and compared it with other data in literature. These experiments, performed in the Nonlinear Wave Lab at ERAU# represent just a preliminary calibration of the experimental protocol. More tests with water of different degrees of turbidity, and possibly wave filed at the water surface are in progress and wi...

  6. Light Reflection from Water Surfaces Perturbed by Falling Rain Droplets

    Science.gov (United States)

    Molesini, Giuseppe; Vannoni, Maurizio

    2009-01-01

    An account of peculiar light patterns produced by reflection in a pool under falling rain droplets was recently reported by Molesini and Vannoni (2008 Eur. J. Phys. 29 403-11). The mathematical approach, however, only covered the case of a symmetrical location of a light source and the observer's eyes with respect to the vertical of the falling…

  7. Enhanced Solar Photoelectrochemical Conversion Efficiency of ZnO:Cu Electrodes for Water-Splitting Application

    Directory of Open Access Journals (Sweden)

    Rekha Dom

    2013-01-01

    Full Text Available n-type ZnO:Cu photoanodes were fabricated by simple spray pyrolysis deposition technique. Influence of low concentration (range ~10−4–10−1% of Cu doping in hexagonal ZnO lattice on its photoelectrochemical performance has been investigated. The doped photoanodes displayed 7-time enhanced conversion efficiencies with respect to their undoped counterpart, as estimated from the photocurrents generated under simulated solar radiation. This is the highest enhancement in the solar conversion efficiency reported so far for the Cu-doped ZnO. This performance is attributed to the red shift in the band gap of the Cu-doped films and is in accordance with the incident-photon-current-conversion efficiency (IPCE measurements. Electrochemical studies reveal an n-type nature of these photoanodes. Thus, the study indicates a high potential of doped ZnO films for solar energy applications, in purview of the development of simple nanostructuring methodologies.

  8. Multi-Application Small Light Water Reactor Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Modro, S.M.; Fisher, J.E.; Weaver, K.D.; Reyes, J.N.; Groome, J.T.; Babka, P.; Carlson, T.M.

    2003-12-01

    The Multi-Application Small Light Water Reactor (MASLWR) project was conducted under the auspices of the Nuclear Energy Research Initiative (NERI) of the U.S. Department of Energy (DOE). The primary project objectives were to develop the conceptual design for a safe and economic small, natural circulation light water reactor, to address the economic and safety attributes of the concept, and to demonstrate the technical feasibility by testing in an integral test facility. This report presents the results of the project. After an initial exploratory and evolutionary process, as documented in the October 2000 report, the project focused on developing a modular reactor design that consists of a self-contained assembly with a reactor vessel, steam generators, and containment. These modular units would be manufactured at a single centralized facility, transported by rail, road, and/or ship, and installed as a series of self-contained units. This approach also allows for staged construction of an NPP and ''pull and replace'' refueling and maintenance during each five-year refueling cycle. Development of the baseline design concept has been sufficiently completed to determine that it complies with the safety requirements and criteria, and satisfies the major goals already noted. The more significant features of the baseline single-unit design concept include: (1) Thermal Power--150 MWt; (2) Net Electrical Output--35 MWe; (3) Steam Generator Type--Vertical, helical tubes; (4) Fuel UO{sub 2}, 8% enriched; (5) Refueling Intervals--5 years; (6) Life-Cycle--60 years. The economic performance was assessed by designing a power plant with an electric generation capacity in the range of current and advanced evolutionary systems. This approach allows for direct comparison of economic performance and forms a basis for further evaluation, economic and technical, of the proposed design and for the design evolution towards a more cost competitive concept

  9. Multi-Application Small Light Water Reactor Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Modro, S.M.; Fisher, J.E.; Weaver, K.D.; Reyes, J.N.; Groome, J.T.; Babka, P.; Carlson, T.M.

    2003-12-01

    The Multi-Application Small Light Water Reactor (MASLWR) project was conducted under the auspices of the Nuclear Energy Research Initiative (NERI) of the U.S. Department of Energy (DOE). The primary project objectives were to develop the conceptual design for a safe and economic small, natural circulation light water reactor, to address the economic and safety attributes of the concept, and to demonstrate the technical feasibility by testing in an integral test facility. This report presents the results of the project. After an initial exploratory and evolutionary process, as documented in the October 2000 report, the project focused on developing a modular reactor design that consists of a self-contained assembly with a reactor vessel, steam generators, and containment. These modular units would be manufactured at a single centralized facility, transported by rail, road, and/or ship, and installed as a series of self-contained units. This approach also allows for staged construction of an NPP and ''pull and replace'' refueling and maintenance during each five-year refueling cycle. Development of the baseline design concept has been sufficiently completed to determine that it complies with the safety requirements and criteria, and satisfies the major goals already noted. The more significant features of the baseline single-unit design concept include: (1) Thermal Power--150 MWt; (2) Net Electrical Output--35 MWe; (3) Steam Generator Type--Vertical, helical tubes; (4) Fuel UO{sub 2}, 8% enriched; (5) Refueling Intervals--5 years; (6) Life-Cycle--60 years. The economic performance was assessed by designing a power plant with an electric generation capacity in the range of current and advanced evolutionary systems. This approach allows for direct comparison of economic performance and forms a basis for further evaluation, economic and technical, of the proposed design and for the design evolution towards a more cost competitive concept

  10. Water-use efficiency in cork oak (Quercus suber) is modified by the interaction of water and light availabilities.

    Science.gov (United States)

    Aranda, Ismael; Pardos, Marta; Puértolas, Jaime; Jiménez, Maria Dolores; Pardos, Jose Alberto

    2007-05-01

    We studied the interaction of light and water on water-use efficiency in cork oak (Quercus suber L.) seedlings. One-year-old cork oak seedlings were grown in pots in a factorial experiment with four light treatments (68, 50, 15 and 5% of full sunlight) and two irrigation regimes: well watered (WW) and moderate drought stress (WS). Leaf predawn water potential, which was measured at the end of each of two cycles, did not differ among the light treatments. Water-use efficiency, assessed by carbon isotope composition (delta(13)C), tended to increase with increasing irradiance. The trend was similar in the WW and WS treatments, though with lower delta(13)C in all light treatments in the WW irrigation regime. Specific leaf area increased with decreasing irradiance, and was inversely correlated with delta(13)C. Thus, changes in delta(13)C could be explained in part by light-induced modifications in leaf morphology. The relationship between stomatal conductance to water vapor and net photosynthesis on a leaf area basis confirmed that seedlings in higher irradiances maintained a higher rate of carbon uptake at a particular stomatal conductance, implying that shaded seedlings have a lower water-use efficiency that is unrelated to water availability.

  11. Light Water Reactor Sustainability Program. Digital Architecture Requirements

    Energy Technology Data Exchange (ETDEWEB)

    Thomas, Kenneth [Idaho National Lab. (INL), Idaho Falls, ID (United States); Oxstrand, Johanna [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2015-03-01

    The Digital Architecture effort is a part of the Department of Energy (DOE) sponsored Light-Water Reactor Sustainability (LWRS) Program conducted at Idaho National Laboratory (INL). The LWRS program is performed in close collaboration with industry research and development (R&D) programs that provides the technical foundations for licensing and managing the long-term, safe, and economical operation of current nuclear power plants (NPPs). One of the primary missions of the LWRS program is to help the U.S. nuclear industry adopt new technologies and engineering solutions that facilitate the continued safe operation of the plants and extension of the current operating licenses. Therefore, a major objective of the LWRS program is the development of a seamless digital environment for plant operations and support by integrating information from plant systems with plant processes for nuclear workers through an array of interconnected technologies. In order to get the most benefits of the advanced technology suggested by the different research activities in the LWRS program, the nuclear utilities need a digital architecture in place to support the technology. A digital architecture can be defined as a collection of information technology (IT) capabilities needed to support and integrate a wide-spectrum of real-time digital capabilities for nuclear power plant performance improvements. It is not hard to imagine that many processes within the plant can be largely improved from both a system and human performance perspective by utilizing a plant wide (or near plant wide) wireless network. For example, a plant wide wireless network allows for real time plant status information to easily be accessed in the control room, field workers’ computer-based procedures can be updated based on the real time plant status, and status on ongoing procedures can be incorporated into smart schedules in the outage command center to allow for more accurate planning of critical tasks. The goal

  12. Light Water Reactor Sustainability Program: Integrated Program Plan

    Energy Technology Data Exchange (ETDEWEB)

    None, None

    2017-05-01

    proliferation and terrorism. The Light Water Reactor Sustainability (LWRS) Program is the primary programmatic activity that addresses Objective 1. This document summarizes the LWRS Program’s plans. For the LWRS Program, sustainability is defined as the ability to maintain safe and economic operation of the existing fleet of nuclear power plants for a longer-than-initially-licensed lifetime. It has two facets with respect to long-term operations: (1) manage the aging of plant systems, structures, and components so that nuclear power plant lifetimes can be extended and the plants can continue to operate safely, efficiently, and economically; and (2) provide science-based solutions to the industry to implement technology to exceed the performance of the current labor-intensive business model.

  13. Infrared to visible image up-conversion using optically addressed spatial light modulator utilizing liquid crystal and InGaAs photodiodes

    Energy Technology Data Exchange (ETDEWEB)

    Solodar, A., E-mail: asisolodar@gmail.com; Arun Kumar, T.; Sarusi, G.; Abdulhalim, I. [Department of Electro-Optics Engineering and The Ilse Katz Institute for Nanoscale Science and Technology, Ben Gurion University of the Negev, Beer Sheva 84105 (Israel)

    2016-01-11

    Combination of InGaAs/InP heterojunction photodetector with nematic liquid crystal (LC) as the electro-optic modulating material for optically addressed spatial light modulator for short wavelength infra-red (SWIR) to visible light image conversion was designed, fabricated, and tested. The photodetector layer is composed of 640 × 512 photodiodes array based on heterojunction InP/InGaAs having 15 μm pitch on InP substrate and with backside illumination architecture. The photodiodes exhibit extremely low, dark current at room temperature, with optimum photo-response in the SWIR region. The photocurrent generated in the heterojunction, due to the SWIR photons absorption, is drifted to the surface of the InP, thus modulating the electric field distribution which modifies the orientation of the LC molecules. This device can be attractive for SWIR to visible image upconversion, such as for uncooled night vision goggles under low ambient light conditions.

  14. Visible Light Responsive Catalyst for Air Water Purification Project

    Science.gov (United States)

    Wheeler, Raymond M.

    2014-01-01

    Investigate and develop viable approaches to render the normally UV-activated TIO2 catalyst visible light responsive (VLR) and achieve high and sustaining catalytic activity under the visible region of the solar spectrum.

  15. Light penetration in the coastal waters off Goa

    Digital Repository Service at National Institute of Oceanography (India)

    Sathyendranath, S.; Varadachari, V.V.R.

    Observations of light penetration have been carried out at 6 stations along the Goa Coast, India, for different periods during 1975-76, using a submarine photometer. Seasonal and spatial variations in the values of irradiance attenuation coefficient...

  16. Maximizing photosynthetic productivity and solar conversion efficiency in microalgae by minimizing the light-harvesting chlorophyll antenna size of the photosystems

    Energy Technology Data Exchange (ETDEWEB)

    Melis, A.; Neidhardt, J.; Benemann, J.R. [Univ. of California, Berkeley, CA (United States). Dept. of Plant and Microbial Biology

    1998-08-01

    The solar conversion efficiency and productivity of photosynthesis in light-acclimated Dunaliella salina (green algae) were analyzed. Cells were grown under continuous low-light (LL; 100 {micro}mol photons/m{sup 2} s) or high-light (HL; 2,000 {micro}mol photons/m{sup 2} s) conditions. HL-grown cells exhibited signs of chronic photoinhibition, i.e., a lower pigment content, a highly truncated chlorophyll (Chl) antenna size for the photosystems, and accumulation of photodamaged photosystem-II (PSII) reaction centers in the chloroplast thylakoids. In spite of these deficiencies, high-light-grown cells showed photosynthetic productivity (300 mmol O{sub 2}/(mol Chl) s) that was {approximately} 3 times greater than that of the normally pigmented LL-grown cells ({approximately} 100 mmol O{sub 2}/(mol Chl) s). Recovery from photoinhibition in the HL-grown cells, induced in the absence of a light-harvesting Chl antenna size enlargement, increased photosynthetic productivity further to {approximately} 650 mmol O{sub 2}/(mol Chl) s. It is shown that, under moderate to high light conditions, D. salina with a highly truncated Chl antenna size will display superior photosynthetic productivity, solar conversion efficiency and H{sub 2} production when compared to the normally pigmented control cells. Estimates of H{sub 2} production in mass culture suggest an average of 200 L H{sub 2}/m{sup 2} d for the cells with the truncated Chl antenna, and less than 50 L H{sub 2}/m{sup 2} d for the normally pigmented cells.

  17. High-throughput simultaneous determination of plasma water deuterium and 18-oxygen enrichment using a high-temperature conversion elemental analyzer with isotope ratio mass spectrometry.

    Science.gov (United States)

    Richelle, M; Darimont, C; Piguet-Welsch, C; Fay, L B

    2004-01-01

    This paper presents a high-throughput method for the simultaneous determination of deuterium and oxygen-18 (18O) enrichment of water samples isolated from blood. This analytical method enables rapid and simple determination of these enrichments of microgram quantities of water. Water is converted into hydrogen and carbon monoxide gases by the use of a high-temperature conversion elemental analyzer (TC-EA), that are then transferred on-line into the isotope ratio mass spectrometer. Accuracy determined with the standard light Antartic precipitation (SLAP) and Greenland ice sheet precipitation (GISP) is reliable for deuterium and 18O enrichments. The range of linearity is from 0 up to 0.09 atom percent excess (APE, i.e. -78 up to 5725 delta per mil (dpm)) for deuterium enrichment and from 0 up to 0.17 APE (-11 up to 890 dpm) for 18O enrichment. Memory effects do exist but can be avoided by analyzing the biological samples in quintuplet. This method allows the determination of 1440 samples per week, i.e. 288 biological samples per week.

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

    Science.gov (United States)

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

    2017-05-01

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

  19. Bioassay using the water soluble fraction of a Nigerian Light Crude ...

    African Journals Online (AJOL)

    Bioassay using the water soluble fraction of a Nigerian Light Crude oil on Clarias ... Heavy metal and total hydrocarbon contents of the water and fish were ... THC concentrations in fish were higher at 96 hours and 14days than in the water ...

  20. Hydrogen Production from Water by Photosynthesis System I for Use as Fuel in Energy Conversion Devices (a.k.a. Understanding Photosystem I as a Biomolecular Reactor for Energy Conversion)

    Science.gov (United States)

    2014-04-01

    Hydrogen Production from Water by Photosynthesis System I for Use as Fuel in Energy Conversion Devices (a.k.a. Understanding Photosystem I as...Laboratory Adelphi, MD 20783-1197 ARL-TR-6904 April 2014 Hydrogen Production from Water by Photosynthesis System I for Use as Fuel in Energy...Final 3. DATES COVERED (From - To) 10/1/2010–10/1/2013 4. TITLE AND SUBTITLE Hydrogen Production from Water by Photosynthesis System I for Use as Fuel

  1. Conversion of sand filters into activated carbon filters at the La Presa (Valencia) water works; Conversion de filtros de arena porcarbon activo en la ETAP de La Presa (Valencia)

    Energy Technology Data Exchange (ETDEWEB)

    Macian Cervera, V. J.; Monforte Monleon, L.; Ribera Orts, R.; Suris Jorda, J. I.; Klee, J. M.

    2007-07-01

    To improve the water quality at potable water treatment plant of La P esa (Valencia), the sand filters have been replaced for activated carbon filters. In the following review the results and conclusions of the direct sand filter conversion into activated carbon filters will be presented. The leads to a simple and fast solution to odour and taste removal, as well as dissolved organic matter, without investments in works at the water works. (Author)

  2. Hydrogeomorphological and water quality impacts of oil palm conversion and logging in Sabah, Malaysian Borneo: a multi-catchment approach

    Science.gov (United States)

    Walsh, Rory; Nainar, Anand; Bidin, Kawi; Higton, Sam; Annammala, Kogilavani; Blake, William; Luke, Sarah; Murphy, Laura; Perryman, Emily; Wall, Katy; Hanapi, Jamil

    2016-04-01

    The last three decades have seen a combination of logging and land-use change across most of the rainforest tropics. This has involved conversion to oil palm across large parts of SE Asia. Although much is now known about the hydrological and sediment transport impacts of logging, relatively little is known about how impacts of oil palm conversion compare with those of logging. Furthermore little is known about the impacts of both on river morphology and water quality. This paper reports some findings of the first phase of a ten-year large-scale manipulative multi-catchment experiment (part of the SAFE - Stability of Altered Forest Ecosystems - Project), based in the upper part of the Brantian Catchment in Sabah, Malaysian Borneo; the project is designed to assess the degree to which adverse impacts of oil palm conversion (on erosion, downstream channel change, water quality and river ecology) might be reduced by retaining buffer zones of riparian forest of varying width from zero to 120 metres. Ten 2 km2 catchments of contrasting land use history have been instrumented since 2011 to record discharge, turbidity, conductivity and water temperature at 5-minute intervals. These comprise 6 repeat-logged catchments being subjected in 2015-16 to conversion to oil palm with varying riparian forest widths; a repeat-logged 'control' catchment; an old regrowth catchment; an oil palm catchment; and a primary forest catchment. In addition, (1) monthly water samples from the catchments have been analysed for nitrates and phosphates, (2) channel cross-sectional change along each stream has been monitored at six-monthly intervals and (3) supplementary surveys have been made of downstream bankfull channel cross-sectional size and water chemistry at a wider range of catchment sites, and (4) sediment cores have been taken and contemporary deposition monitored at a hierarchical network of sites in the large Brantian catchment for geochemical analysis and dating to establish the

  3. Reversible conversion of water-droplet mobility from rollable to pinned on a superhydrophobic functionalized carbon nanotube film.

    Science.gov (United States)

    Yang, Jin; Zhang, Zhaozhu; Men, Xuehu; Xu, Xianghui; Zhu, Xiaotao

    2010-06-01

    Poly(acrylic acid)-block-polystyrene (PAA-b-PS) functionalized multiwall carbon nanotubes (MWNTs) were prepared by nitroxide-mediated "living" free-radical polymerization. The product functionalized MWNTs (MWNT-PAA-b-PS) contained 20% by weight PAA-b-PS based on the infrared spectroscopy analysis and thermal gravimetric analysis. Such MWNT-PAA-b-PS nanoparticles can be used in spray coating method to fabricate superhydrophobic MWNT films, and water-droplet mobility on the superhydrophobic film can be reversibly converted from rollable to pinned through adjusting the appearance of PAA chains on the topmost surface of the film. Switching mechanism has been discussed in detail. We also directly observed the air-solid-liquid interface from the above of a water droplet by a microscope to confirm the superhydrophobic states, and proved that the transition between the wettability states appeared on the same surface with reversible conversion of water-droplet mobility.

  4. High conversion of sugarcane bagasse into monosaccharides based on sodium hydroxide pretreatment at low water consumption and wastewater generation.

    Science.gov (United States)

    Wang, Wen; Wang, Qiong; Tan, Xuesong; Qi, Wei; Yu, Qiang; Zhou, Guixiong; Zhuang, Xinshu; Yuan, Zhenhong

    2016-10-01

    The generation of a great quantity of black liquor (BL) and waste wash water (WWW) has been key problems of the alkaline pretreatment. This work tried to build a sustainable way to recycle the BL for pretreating sugarcane bagasse (SCB) and the WWW for washing the residual solid (RS) of alkali-treated SCB which would be subsequently hydrolysed and fermented. The enzymatic hydrolysis efficiency of the washed RS decreased with the recycling times of BL and WWW increasing. Tween80 at the loading of 0.25% (V/V) could notably improve the enzymatic hydrolysis and had no negative impact on the downstream fermentation. Compared with the non-recycling and BL recycling ways based on alkaline pretreatment, the BL-WWW recycling way could not only maintain high conversion of carbohydrate into monosaccharides and save alkali amount of 45.5%, but also save more than 80% water and generate less than 15% waste water.

  5. Removal of fluorescence and ultraviolet absorbance of dissolved organic matter in reclaimed water by solar light.

    Science.gov (United States)

    Wu, Qianyuan; Li, Chao; Wang, Wenlong; He, Tao; Hu, Hongying; Du, Ye; Wang, Ting

    2016-05-01

    Storing reclaimed water in lakes is a widely used method of accommodating changes in the consumption of reclaimed water during wastewater reclamation and reuse. Solar light serves as an important function in degrading pollutants during storage, and its effect on dissolved organic matter (DOM) was investigated in this study. Solar light significantly decreased the UV254 absorbance and fluorescence (FLU) intensity of reclaimed water. However, its effect on the dissolved organic carbon (DOC) value of reclaimed water was very limited. The decrease in the UV254 absorbance intensity and FLU excitation-emission matrix regional integration volume (FLU volume) of reclaimed water during solar light irradiation was fit with pseudo-first order reaction kinetics. The decrease of UV254 absorbance was much slower than that of the FLU volume. Ultraviolet light in solar light had a key role in decreasing the UV254 absorbance and FLU intensity during solar light irradiation. The light fluence-based removal kinetic constants of the UV254 and FLU intensity were independent of light intensity. The peaks of the UV254 absorbance and FLU intensity with an apparent molecular weight (AMW) of 100Da to 2000Da decreased after solar irradiation, whereas the DOC value of the major peaks did not significantly change.

  6. Critical reflections on building a community of conversation about water governance in Australia

    National Research Council Canada - National Science Library

    Naomi Rubenstein; Philip J Wallis; Raymond L Ison; Lee Godden

    2016-01-01

    ... of transforming situations usefully framed as 'wicked'. Despite international investment in water governance research, a national research agenda on water governance was lacking in Australia in the late 2000s as were mechanisms to build the capacity...

  7. Critical behavior of 2,6-dimethylpyridine-water: Measurements of specific heat, dynamic light scattering, and shear viscosity

    DEFF Research Database (Denmark)

    Mirzaev, S. Z.; Behrends, R.; Heimburg, Thomas Rainer

    2006-01-01

    2,6-dimethylpyridine-water, specific heat, dynamic light scattering, shear viscosity Udgivelsesdato: 14 April......2,6-dimethylpyridine-water, specific heat, dynamic light scattering, shear viscosity Udgivelsesdato: 14 April...

  8. Influence of light-polymerization modes on the degree of conversion and mechanical properties of resin composites: a comparative analysis between a hybrid and a nanofilled composite.

    Science.gov (United States)

    da Silva, Eduardo Moreira; Poskus, Laiza Tatiana; Guimarães, José Guilherme Antunes

    2008-01-01

    This study analyzed the influence of the light polymerization mode on the degree of conversion (DC) and mechanical properties of two resin composites: a hybrid (Filtek P60) and a nanofilled composite (Filtek Supreme). The composites were light activated by three light polymerization modes (Standard-S: 650 mW/cm2 for 30 seconds; High intensity-H: 1000 mW/cm2 for 20 seconds and Gradual-G: 100 up to 1000 mW/cm2 for 10 seconds + 1000 mW/cm2 for 10 seconds). The DC (%) was measured by FT-Raman spectroscopy. Flexural strength and flexural modulus were obtained from bar-shaped specimens (1 x 2 x 10 mm) submitted to the three-point bending test. Microhardness was evaluated by Knoop indentation (KHN). Data were analyzed by ANOVA and Student-Newman-Keuls multiple range test and linear regression analysis. The results showed the following DC: H > S > G (p hybrid > nanofilled (p S = G (p hybrid composite presented higher flexural strength and flexural modulus than the nanofilled composite (p composites (p = 0.1605). The results suggest that nanofilled composites may present a lower degree of conversion and reduced mechanical properties compared to hybrid composites.

  9. Technology of the light water reactor fuel cycle

    Energy Technology Data Exchange (ETDEWEB)

    Wymer, R. G.

    1979-01-01

    This essay presents elements of the processes used in the fuel cycle steps and gives an indication of the types of equipment used. The amounts of radioactivity released in normal operation of the processes are indicated and related to radiation doses. Types and costs of equipment or processes required to lower these radioactivity releases are in some cases suggested. Mining and milling, conversion of uranium concentrate to UF/sub 6/, uranium isotope separation, LWR fuel fabrication, fuel reprocessing, transportation, and waste management are covered in this essay. 40 figures, 34 tables. (DLC)

  10. SWCNT Photocatalyst for Hydrogen Production from Water upon Photoexcitation of (8, 3) SWCNT at 680-nm Light

    Science.gov (United States)

    Murakami, Noritake; Tango, Yuto; Miyake, Hideaki; Tajima, Tomoyuki; Nishina, Yuta; Kurashige, Wataru; Negishi, Yuichi; Takaguchi, Yutaka

    2017-03-01

    Single-walled carbon nanotubes (SWCNTs) are potentially strong optical absorbers with tunable absorption bands depending on their chiral indices (n, m). Their application for solar energy conversion is difficult because of the large binding energy (>100 meV) of electron-hole pairs, known as excitons, produced by optical absorption. Recent development of photovoltaic devices based on SWCNTs as light-absorbing components have shown that the creation of heterojunctions by pairing chirality-controlled SWCNTs with C60 is the key for high power conversion efficiency. In contrast to thin film devices, photocatalytic reactions in a dispersion/solution system triggered by the photoexcitation of SWCNTs have never been reported due to the difficulty of the construction of a well-ordered surface on SWCNTs. Here, we show a clear-cut example of a SWCNT photocatalyst producing H2 from water. Self-organization of a fullerodendron on the SWCNT core affords water-dispersible coaxial nanowires possessing SWCNT/C60 heterojunctions, of which a dendron shell can act as support of a co-catalyst for H2 evolution. Because the band offset between the LUMO levels of (8, 3)SWCNT and C60 satisfactorily exceeds the exciton binding energy to allow efficient exciton dissociation, the (8, 3)SWCNT/fullerodendron coaxial photocatalyst shows H2-evolving activity (QY = 0.015) upon 680-nm illumination, which is E22 absorption of (8, 3) SWCNT.

  11. SWCNT Photocatalyst for Hydrogen Production from Water upon Photoexcitation of (8, 3) SWCNT at 680-nm Light

    Science.gov (United States)

    Murakami, Noritake; Tango, Yuto; Miyake, Hideaki; Tajima, Tomoyuki; Nishina, Yuta; Kurashige, Wataru; Negishi, Yuichi; Takaguchi, Yutaka

    2017-01-01

    Single-walled carbon nanotubes (SWCNTs) are potentially strong optical absorbers with tunable absorption bands depending on their chiral indices (n, m). Their application for solar energy conversion is difficult because of the large binding energy (>100 meV) of electron-hole pairs, known as excitons, produced by optical absorption. Recent development of photovoltaic devices based on SWCNTs as light-absorbing components have shown that the creation of heterojunctions by pairing chirality-controlled SWCNTs with C60 is the key for high power conversion efficiency. In contrast to thin film devices, photocatalytic reactions in a dispersion/solution system triggered by the photoexcitation of SWCNTs have never been reported due to the difficulty of the construction of a well-ordered surface on SWCNTs. Here, we show a clear-cut example of a SWCNT photocatalyst producing H2 from water. Self-organization of a fullerodendron on the SWCNT core affords water-dispersible coaxial nanowires possessing SWCNT/C60 heterojunctions, of which a dendron shell can act as support of a co-catalyst for H2 evolution. Because the band offset between the LUMO levels of (8, 3)SWCNT and C60 satisfactorily exceeds the exciton binding energy to allow efficient exciton dissociation, the (8, 3)SWCNT/fullerodendron coaxial photocatalyst shows H2-evolving activity (QY = 0.015) upon 680-nm illumination, which is E22 absorption of (8, 3) SWCNT. PMID:28262708

  12. Global impacts of conversions from natural to agricultural ecosystems on water resources: Quantity versus quality

    Science.gov (United States)

    Scanlon, B.R.; Jolly, I.; Sophocleous, M.; Zhang, L.

    2007-01-01

    [1] Past land use changes have greatly impacted global water resources, with often opposing effects on water quantity and quality. Increases in rain-fed cropland (460%) and pastureland (560%) during the past 300 years from forest and grasslands decreased evapotranspiration and increased recharge (two orders of magnitude) and streamflow (one order of magnitude). However, increased water quantity degraded water quality by mobilization of salts, salinization caused by shallow water tables, and fertilizer leaching into underlying aquifers that discharge to streams. Since the 1950s, irrigated agriculture has expanded globally by 174%, accounting for ???90% of global freshwater consumption. Irrigation based on surface water reduced streamflow and raised water tables resulting in waterlogging in many areas (China, India, and United States). Marked increases in groundwater-fed irrigation in the last few decades in these areas has lowered water tables (???1 m/yr) and reduced streamflow. Degradation of water quality in irrigated areas has resulted from processes similar to those in rain-fed agriculture: salt mobilization, salinization in waterlogged areas, and fertilizer leaching. Strategies for remediating water resource problems related to agriculture often have opposing effects on water quantity and quality. Long time lags (decades to centuries) between land use changes and system response (e.g., recharge, streamflow, and water quality), particularly in semiarid regions, mean that the full impact of land use changes has not been realized in many areas and remediation to reverse impacts will also take a long time. Future land use changes should consider potential impacts on water resources, particularly trade-offs between water, salt, and nutrient balances, to develop sustainable water resources to meet human and ecosystem needs. Copyright 2007 by the American Geophysical Union.

  13. Process and apparatus for conversion of water vapor with coal or hydrocarbon into a product gas

    Energy Technology Data Exchange (ETDEWEB)

    Weirich, W.; Barnert, H.; Oertel, M.; Schulten, R.

    1990-03-27

    A process and apparatus are provided for conversion of steam and hydrocarbon, or steam and coal, into a product gas which contains hydrogen. The conversion rate is augmented by effective extraction and removal of hydrogen as and when hydrogen is generated. Within a reaction vessel wherein the conversion takes place, a chamber for collection of hydrogen is formed by the provision of a hydrogen permeable membrane. The chamber is provided with a hydrogen extraction means and houses a support structure, for example, in the form of a mesh providing structural support to the membrane. The membrane may be of a pleated or corrugated construction, so as to provide an enlarged surface for the membrane to facilitate hydrogen extraction. Also, to further facilitate hydrogen extraction, a hydrogen partial pressure differential is maintained across the membrane, such as, for example, by the counter pressure of an inert gas. A preferred configuration for the apparatus of the invention is a tubular construction which houses generally tubular hydrogen extraction chambers. 5 figs.

  14. Agricultural conversion without external water and nutrient inputs reduces terrestrial vegetation productivity

    Science.gov (United States)

    Smith, W. Kolby; Cleveland, Cory C.; Reed, Sasha C.; Running, Steven W.

    2014-01-01

    Driven by global population and standard of living increases, humanity co-opts a growing share of the planet's natural resources resulting in many well-known environmental trade-offs. In this study, we explored the impact of agriculture on a resource fundamental to life on Earth: terrestrial vegetation growth (net primary production; NPP). We demonstrate that agricultural conversion has reduced terrestrial NPP by ~7.0%. Increases in NPP due to agricultural conversion were observed only in areas receiving external inputs (i.e., irrigation and/or fertilization). NPP reductions were found for ~88% of agricultural lands, with the largest reductions observed in areas formerly occupied by tropical forests and savannas (~71% and ~66% reductions, respectively). Without policies that explicitly consider the impact of agricultural conversion on primary production, future demand-driven increases in agricultural output will likely continue to drive net declines in global terrestrial productivity, with potential detrimental consequences for net ecosystem carbon storage and subsequent climate warming.

  15. Relation between soil matrix potential changes and water conversion ratios during methane hydrate formation processes in loess

    Institute of Scientific and Technical Information of China (English)

    Peng Zhang; Qingbai Wu; Guanli Jiang; Yibin Pu

    2011-01-01

    With a new apparatus designed and assembled by ourselves,the matrix potential of non-saturated loess was firstly measured and studied during methane hydrate formation processes.The experimental results showed that during two formation processes,the matrix potential changes of the loess all presented a good linear relationship with water conversion ratios.In addition,although it was well known that the secondary gas hydrate formation was easier than the initial,our experimental results showed that the initial hydrate formation efficiency in non-saturated loess was higher than that of the secondary.

  16. Lighting

    Data.gov (United States)

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

  17. 78 FR 64029 - Cost-Benefit Analysis for Radwaste Systems for Light-Water-Cooled Nuclear Power Reactors

    Science.gov (United States)

    2013-10-25

    ... COMMISSION Cost-Benefit Analysis for Radwaste Systems for Light-Water-Cooled Nuclear Power Reactors AGENCY... Systems for Light-Water-Cooled Nuclear Power Reactors,'' in which the NRC made editorial corrections and... analysis for liquid and gaseous radwaste system components for light water nuclear power...

  18. 10-fold enhancement in light-driven water splitting using niobium oxynitride microcone array films

    KAUST Repository

    Shaheen, Basamat

    2016-03-26

    We demonstrate, for the first time, the synthesis of highly ordered niobium oxynitride microcones as an attractive class of materials for visible-light-driven water splitting. As revealed by the ultraviolet photoelectron spectroscopy (UPS), photoelectrochemical and transient photocurrent measurements, the microcones showed enhanced performance (~1000% compared to mesoporous niobium oxide) as photoanodes for water splitting with remarkable stability and visible light activity. © 2016 Elsevier B.V. All rights reserved.

  19. Design of a Low-Light-Level Image Sensor with On-Chip Sigma-Delta Analog-to- Digital Conversion

    Science.gov (United States)

    Mendis, Sunetra K.; Pain, Bedabrata; Nixon, Robert H.; Fossum, Eric R.

    1993-01-01

    The design and projected performance of a low-light-level active-pixel-sensor (APS) chip with semi-parallel analog-to-digital (A/D) conversion is presented. The individual elements have been fabricated and tested using MOSIS* 2 micrometer CMOS technology, although the integrated system has not yet been fabricated. The imager consists of a 128 x 128 array of active pixels at a 50 micrometer pitch. Each column of pixels shares a 10-bit A/D converter based on first-order oversampled sigma-delta (Sigma-Delta) modulation. The 10-bit outputs of each converter are multiplexed and read out through a single set of outputs. A semi-parallel architecture is chosen to achieve 30 frames/second operation even at low light levels. The sensor is designed for less than 12 e^- rms noise performance.

  20. Design of a Low-Light-Level Image Sensor with On-Chip Sigma-Delta Analog-to- Digital Conversion

    Science.gov (United States)

    Mendis, Sunetra K.; Pain, Bedabrata; Nixon, Robert H.; Fossum, Eric R.

    1993-01-01

    The design and projected performance of a low-light-level active-pixel-sensor (APS) chip with semi-parallel analog-to-digital (A/D) conversion is presented. The individual elements have been fabricated and tested using MOSIS* 2 micrometer CMOS technology, although the integrated system has not yet been fabricated. The imager consists of a 128 x 128 array of active pixels at a 50 micrometer pitch. Each column of pixels shares a 10-bit A/D converter based on first-order oversampled sigma-delta (Sigma-Delta) modulation. The 10-bit outputs of each converter are multiplexed and read out through a single set of outputs. A semi-parallel architecture is chosen to achieve 30 frames/second operation even at low light levels. The sensor is designed for less than 12 e^- rms noise performance.

  1. Conversion of thermal energy into electricity via a water pump operating in Stirling engine cycle

    Energy Technology Data Exchange (ETDEWEB)

    Slavin, V.S. [Institute of Thermophysics SB RAS (Russian Federation); Bakos, G.C. [Democritus University of Thrace, Department of Electrical and Computer Engineering, Laboratory of Energy Economics, 67 100 Xanthi (Greece); Finnikov, K.A. [Siberian Federal University (Russian Federation)

    2009-07-15

    In this paper, the principle of heat energy conversion via Stirling pump into electricity is considered. New scheme of Stirling pump is proposed, that differs from known ones in application of offset heater and cooler and valves controlling the motion of liquid. The mathematical model is implemented to examine the liquid flow and gas heat exchange in cylinders and regenerator. The numerical simulation of engine's working cycle is conducted for the purpose of determining the characteristic parameters of its design. A possibility of achieving high thermal efficiency at acceptable power level is shown. (author)

  2. Hydrothermal Conversion in Near-Critical Water – A Sustainable Way of Producing Renewable Fuels

    DEFF Research Database (Denmark)

    Hoffmann, Jessica; Pedersen, Thomas Helmer; Rosendahl, Lasse

    2014-01-01

    Liquid fuels from biomass will form an essential part of meeting the grand challenges within energy. The need for renewable and sustainable energy sources is triggered by a number of factors; like increase in global energy demand, depletion of conventional resources, climate issues and the desire...... for national/regional energy independence. Especially in marine, aviation and heavy land transport suitable carbon neutral drop-in fuels from biomass are needed, since electrification of those is rather unlikely. Hydrothermal conversion (HTC) of biomass offers a solution and is a sustainable way of converting...

  3. Hydrothermal Conversion in Near-Critical Water – A Sustainable Way of Producing Renewable Fuels

    DEFF Research Database (Denmark)

    Hoffmann, Jessica; Pedersen, Thomas Helmer; Rosendahl, Lasse

    2014-01-01

    Liquid fuels from biomass will form an essential part of meeting the grand challenges within energy. The need for renewable and sustainable energy sources is triggered by a number of factors; like increase in global energy demand, depletion of conventional resources, climate issues and the desire...... for national/regional energy independence. Especially in marine, aviation and heavy land transport suitable carbon neutral drop-in fuels from biomass are needed, since electrification of those is rather unlikely. Hydrothermal conversion (HTC) of biomass offers a solution and is a sustainable way of converting...

  4. Light

    DEFF Research Database (Denmark)

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

    2004-01-01

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

  5. A mild and effective method for the conversion of alkenes into alcohols in subcritical water

    Directory of Open Access Journals (Sweden)

    RECEP OZEN

    2007-10-01

    Full Text Available Alkenes were oxidized to alcohols in subcritical water. A number of alkenes were oxidized directly to their alcohols in excellent yields. The syntheses were performed in 215 cm3 stainless steel high pressure reactor at 120 ºC in 150 cm3 water. The yields of alcohols increased with the nitrogen pressure.

  6. Influence of light guide tip used in the photo-activation on degree of conversion and hardness of one nanofilled dental composite

    Science.gov (United States)

    Galvão, M. R.; Costa, S. X. S.; Victorino, K. R.; Ribeiro, A. A.; Menezes, F. C. H.; Rastelli, A. N. S.; Bagnato, V. S.; Andrade, M. F.

    2010-12-01

    The aim of this study was to evaluate the degree of conversion and hardness of a dental composite resin Filtek™ Z-350 (3M ESPE, Dental Products St. Paul, MN) photo-activated for 20 s of irradiation time with two different light guide tips, metal and polymer, coupled on blue LED Ultraled LCU (Dabi Atlante, SP, Brazil). With the metal light tip, power density was of 352 and with the polymer was of 456 mW/cm2, respectively. Five samples (4 mm in diameter and 2mm in thickness—ISO 4049), were made for each Group evaluated. The measurements for DC (%) were made in a Nexus-470 FT-IR, Thermo Nicolet, E.U.A. Spectroscopy (FTIR). Spectra for both uncured and cured samples were analyzed using an accessory of reflectance diffuse. The measurements were recorded in absorbance operating under the following conditions: 32 scans, 4 cm-1 resolution, 300-4000 cm-1 wavelength. The percentage of unreacted carbon double bonds (% C=C) was determined from the ratio of absorbance intensities of aliphatic C=C (peak at 1637 cm-1) against internal standard before and after curing of the sample: aromatic C-C (peak at 1610 cm-1). The Vickers hardness measurements (top and bottom surfaces) were performed in a universal testing machine (Buehler MMT-3 digital microhardness tester Lake Bluff, Illinois USA). A 50 gf load was used and the indenter with a dwell time of 30 s. The data were submitted to the test t Student at significance level of 5%. The mean values of degree of conversion for the polymer and metal light guide tip no were statistically different ( p = 0.8389). The hardness mean values were no statistically significant different among the light guide tips ( p = 0.6244), however, there was difference between top and bottom surfaces ( p < 0.001). The results show that so much the polymer light tip as the metal light tip can be used for the photo-activation, probably for the low quality of the light guide tip metal.

  7. Effect of nitrogen and intrinsic defect complexes on conversion efficiency of ZnO for hydrogen generation from water.

    Science.gov (United States)

    Lu, Y H; Russo, S P; Feng, Y P

    2011-09-21

    Band gap narrowing is important for applications of ZnO, especially for photoelectrochemical water splitting. In this work, we carried out first-principles electronic structure calculations with a hybrid density functional on defected ZnO. It is found that nitrogen substitutional doping alone cannot explain the largely enhanced conversion efficiency observed in nitrogen doped ZnO. Instead, complex defects formed by substitutional nitrogen and intrinsic defects play an important role in the band gap narrowing, in agreement with recent experimental results. We propose ZnO fabricated in a Zn-rich environment with heavy nitrogen doping as a photocatalyst for hydrogen generation from water splitting. A method for controlling the band gap of ZnO is also proposed.

  8. Model Predictive Control-based Power take-off Control of an Oscillating Water Column Wave Energy Conversion System

    Science.gov (United States)

    Rajapakse, G.; Jayasinghe, S. G.; Fleming, A.; Shahnia, F.

    2017-07-01

    Australia’s extended coastline asserts abundance of wave and tidal power. The predictability of these energy sources and their proximity to cities and towns make them more desirable. Several tidal current turbine and ocean wave energy conversion projects have already been planned in the coastline of southern Australia. Some of these projects use air turbine technology with air driven turbines to harvest the energy from an oscillating water column. This study focuses on the power take-off control of a single stage unidirectional oscillating water column air turbine generator system, and proposes a model predictive control-based speed controller for the generator-turbine assembly. The proposed method is verified with simulation results that show the efficacy of the controller in extracting power from the turbine while maintaining the speed at the desired level.

  9. Effects of Light and Water Availability on the Performance of Hemlock Woolly Adelgid (Hemiptera: Adelgidae).

    Science.gov (United States)

    Hickin, Mauri; Preisser, Evan L

    2015-02-01

    Eastern hemlock (Tsuga canadensis (L.) Carriere) is a dominant shade-tolerant tree in northeastern United States that has been declining since the arrival of the hemlock woolly adelgid (Adelges tsugae Annand). Determining where A. tsugae settles under different abiotic conditions is important in understanding the insect's expansion. Resource availability such as light and water can affect herbivore selectivity and damage. We examined how A. tsugae settlement and survival were affected by differences in light intensity and water availability, and how adelgid affected tree performance growing in these different abiotic treatments. In a greenhouse at the University of Rhode Island, we conducted an experiment in which the factors light (full-sun, shaded), water (water-stressed, watered), and adelgid (infested, insect-free) were fully crossed for a total of eight treatments (20 two-year-old hemlock saplings per treatment). We measured photosynthesis, transpiration, water potential, relative water content, adelgid density, and survival throughout the experiment. Adelgid settlement was higher on the old-growth foliage of shaded and water-stressed trees, but their survival was not altered by foliage age or either abiotic factor. The trees responded more to the light treatments than the water treatments. Light treatments caused a difference in relative water content, photosynthetic rate, transpiration, and water potential; however, water availability did not alter these variables. Adelgid did not enhance the impact of these abiotic treatments. Further studies are needed to get a better understanding of how these abiotic factors impact adelgid densities and tree health, and to determine why adelgid settlement was higher in the shaded treatments. © The Author 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  10. Dual-enhanced photothermal conversion properties of reduced graphene oxide-coated gold superparticles for light-triggered acoustic and thermal theranostics.

    Science.gov (United States)

    Lin, Li-Sen; Yang, Xiangyu; Niu, Gang; Song, Jibin; Yang, Huang-Hao; Chen, Xiaoyuan

    2016-01-28

    A rational design of highly efficient photothermal agents that possess excellent light-to-heat conversion properties is a fascinating topic in nanotheranostics. Herein, we present a facile route to fabricate size-tunable reduced graphene oxide (rGO)-coated gold superparticles (rGO-GSPs) and demonstrate their dual-enhanced photothermal conversion properties for photoacoustic imaging and photothermal therapy. For the first time, graphene oxide (GO) was directly used as an emulsifying agent for the preparation of gold superparticles (GSPs) with near-infrared absorption by the emulsion method. Moreover, GO spontaneously deposited on the surface of GSPs could also act as the precursor of the rGO shell. Importantly, both the plasmonic coupling of the self-assembled gold nanoparticles and the interaction between GSPs and rGO endow rGO-GSPs with enhanced photothermal conversion properties, allowing rGO-GSPs to be used for sensitive photoacoustic detection and efficient photothermal ablation of tumours in vivo. This study provides a facile approach to prepare colloidal superparticles-graphene hybrid nanostructures and will pave the way toward the design and optimization of photothermal nanomaterials with improved properties for theranostic applications.

  11. Scalable water splitting on particulate photocatalyst sheets with a solar-to-hydrogen energy conversion efficiency exceeding 1.

    Science.gov (United States)

    Wang, Qian; Hisatomi, Takashi; Jia, Qingxin; Tokudome, Hiromasa; Zhong, Miao; Wang, Chizhong; Pan, Zhenhua; Takata, Tsuyoshi; Nakabayashi, Mamiko; Shibata, Naoya; Li, Yanbo; Sharp, Ian D; Kudo, Akihiko; Yamada, Taro; Domen, Kazunari

    2016-06-01

    Photocatalytic water splitting using particulate semiconductors is a potentially scalable and economically feasible technology for converting solar energy into hydrogen. Z-scheme systems based on two-step photoexcitation of a hydrogen evolution photocatalyst (HEP) and an oxygen evolution photocatalyst (OEP) are suited to harvesting of sunlight because semiconductors with either water reduction or oxidation activity can be applied to the water splitting reaction. However, it is challenging to achieve efficient transfer of electrons between HEP and OEP particles. Here, we present photocatalyst sheets based on La- and Rh-codoped SrTiO3 (SrTiO3:La, Rh; ref. ) and Mo-doped BiVO4 (BiVO4:Mo) powders embedded into a gold (Au) layer. Enhancement of the electron relay by annealing and suppression of undesirable reactions through surface modification allow pure water (pH 6.8) splitting with a solar-to-hydrogen energy conversion efficiency of 1.1% and an apparent quantum yield of over 30% at 419 nm. The photocatalyst sheet design enables efficient and scalable water splitting using particulate semiconductors.

  12. Scalable water splitting on particulate photocatalyst sheets with a solar-to-hydrogen energy conversion efficiency exceeding 1%

    Science.gov (United States)

    Wang, Qian; Hisatomi, Takashi; Jia, Qingxin; Tokudome, Hiromasa; Zhong, Miao; Wang, Chizhong; Pan, Zhenhua; Takata, Tsuyoshi; Nakabayashi, Mamiko; Shibata, Naoya; Li, Yanbo; Sharp, Ian D.; Kudo, Akihiko; Yamada, Taro; Domen, Kazunari

    2016-06-01

    Photocatalytic water splitting using particulate semiconductors is a potentially scalable and economically feasible technology for converting solar energy into hydrogen. Z-scheme systems based on two-step photoexcitation of a hydrogen evolution photocatalyst (HEP) and an oxygen evolution photocatalyst (OEP) are suited to harvesting of sunlight because semiconductors with either water reduction or oxidation activity can be applied to the water splitting reaction. However, it is challenging to achieve efficient transfer of electrons between HEP and OEP particles. Here, we present photocatalyst sheets based on La- and Rh-codoped SrTiO3 (SrTiO3:La, Rh; ref. ) and Mo-doped BiVO4 (BiVO4:Mo) powders embedded into a gold (Au) layer. Enhancement of the electron relay by annealing and suppression of undesirable reactions through surface modification allow pure water (pH 6.8) splitting with a solar-to-hydrogen energy conversion efficiency of 1.1% and an apparent quantum yield of over 30% at 419 nm. The photocatalyst sheet design enables efficient and scalable water splitting using particulate semiconductors.

  13. Impacts of forest to urban land conversion and ENSO phase on water quality of a public water supply reservoir

    Science.gov (United States)

    We used coupled watershed and reservoir models to evaluate the impacts of deforestation and ENSO phase on drinking water quality. Source water total organic carbon (TOC) is especially important due to the potential for production of carcinogenic disinfection byproducts (DBPs). The Environmental Flui...

  14. Temporal Quantum Correlations in Inelastic Light Scattering from Water

    Science.gov (United States)

    Kasperczyk, Mark; de Aguiar Júnior, Filomeno S.; Rabelo, Cassiano; Saraiva, Andre; Santos, Marcelo F.; Novotny, Lukas; Jorio, Ado

    2016-12-01

    Water is one of the most prevalent chemicals on our planet, an integral part of both our environment and our existence as a species. Yet it is also rich in anomalous behaviors. Here we reveal that water is a novel—yet ubiquitous—source for quantum correlated photon pairs at ambient conditions. The photon pairs are produced through Raman scattering, and the correlations arise from the shared quantum of a vibrational mode between the Stokes and anti-Stokes scattering events. We confirm the nonclassical nature of the produced photon pairs by showing that the cross-correlation and autocorrelations of the signals violate a Cauchy-Schwarz inequality by over 5 orders of magnitude. The unprecedented degree of violating the inequality in pure water, as well as the well-defined polarization properties of the photon pairs, points to its usefulness in quantum information.

  15. The High-Altitude Water Cherenkov Observatory: First Light

    Science.gov (United States)

    Weisgarber, Thomas

    2013-04-01

    The High-Altitude Water Cherenkov (HAWC) Observatory is under construction at Sierra Negra in the state of Puebla in Mexico. Operation began in September 2012, with the first 30 out of the final 300 water Cherenkov detectors deployed and in data acquisition. The HAWC Observatory is designed to record particle air showers from gamma rays and cosmic rays with TeV energies. Though the detector is only 10% complete, HAWC is already the world's largest water Cherenkov detector in the TeV band. In this presentation, I will summarize the performance of the detector to date and discuss preliminary observations of cosmic-ray and gamma-ray sources. I will also describe deployment plans for the remainder of the detector and outline prospects for TeV observations in the coming year.

  16. The Fabrication of Ga2O3/ZSM-5 Hollow Fibers for Efficient Catalytic Conversion of n-Butane into Light Olefins and Aromatics

    Directory of Open Access Journals (Sweden)

    Jing Han

    2016-01-01

    Full Text Available In this study, the dehydrogenation component of Ga2O3 was introduced into ZSM-5 nanocrystals to prepare Ga2O3/ZSM-5 hollow fiber-based bifunctional catalysts. The physicochemical features of as-prepared catalysts were characterized by means of XRD, BET, SEM, STEM, NH3-TPD, etc., and their performances for the catalytic conversion of n-butane to produce light olefins and aromatics were investigated. The results indicated that a very small amount of gallium can cause a marked enhancement in the catalytic activity of ZSM-5 because of the synergistic effect of the dehydrogenation and aromatization properties of Ga2O3 and the cracking function of ZSM-5. Compared with Ga2O3/ZSM-5 nanoparticles, the unique hierarchical macro-meso-microporosity of the as-prepared hollow fibers can effectively enlarge the bifunctionality by enhancing the accessibility of active sites and the diffusion. Consequently, Ga2O3/ZSM-5 hollow fibers show excellent catalytic conversion of n-butane, with the highest yield of light olefins plus aromatics at 600 °C by 87.6%, which is 56.3%, 24.6%, and 13.3% higher than that of ZSM-5, ZSM-5 zeolite fibers, and Ga2O3/ZSM-5, respectively.

  17. Plasmonic Non-linear Conversion of Continuous Wave Light by Gold Nanoparticle Clusters withFluorescent Protein Loaded Gaps

    CERN Document Server

    Salakhutdinov, Ildar; Abak, Musa Kurtulus; Turkpence, Deniz; Piantanida, Luca; Fruk, Ljiljana; Tasgin, Mehmet Emre; Lazzarino, Marco; Bek, Alpan

    2014-01-01

    We propose and demonstrate a method which is feasible for deterministic activation of few molecules. Our method relies on non-linear optical excitation of few enhanced yellow fluorescent protein molecules that are sandwiched between gaps of asymmetrically constructed plasmonic gold nanoparticle clusters. We observe that as infrared photons, which cannot get absorbed by fluorescent molecules, are converted through efficient second harmonic generation activity of gold nanoparticles to visible photons, the molecules absorb them and fluoresce. Our numerical simulations demonstrate that observation of SHG with cw laser becomes possible owing to the cooperative action of conversion enhancement through Fano resonance, hybridization in the plasmon absorption spectrum and the size asymmetry of nanoparticle dimers.

  18. Identifying the role of the local density of optical states in frequency conversion of light in a microcavity

    CERN Document Server

    Yüce, Emre; Claudon, Julien; Gérard, Jean-Michel; Vos, Willem L

    2014-01-01

    We have reversibly switched the resonance of a GaAs-AlAs microcavity in the near-infrared near $\\lambda =1300$ nm within 300 fs by the electronic Kerr effect. We reveal by pump-probe spectroscopy a remarkable red shift or blue shift of the light confined inside the cavity for small pulse delays, depending on their temporal ordering. The color-converted light is efficiently generated in a broad frequency continuum that differs markedly from the instantaneous cavity resonance in terms of the central frequency and bandwidth. From observations on cavities with different quality factors, we identify the role of the local density of optical states (LDOS) available to the newly generated light frequencies. In particular, we distinguish the effect of the LDOS related to the cavity resonance itself, and the LDOS continuum that leaks in from the vacuum surrounding the cavity. Our new insights provide a unified picture for seemingly disparate results in traditional and nanophotonic nonlinear optics.

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

    Science.gov (United States)

    Mansuripur, Masud

    2016-09-01

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

  20. Stretched Lens Array (SLA) for Collection and Conversion of Infrared Laser Light: 45% Efficiency Demonstrated for Near-Term 800 W/kg Space Power System

    Science.gov (United States)

    O'Neill, Mark; Howell, Joe; Fikes, John; Fork, Richard; Phillips, Dane; Aiken, Dan; McDanal, A. J.

    2006-01-01

    For the past 2% years, our team has been developing a unique photovoltaic concentrator array for collection and conversion of infrared laser light. This laser-receiving array has evolved from the solar-receiving Stretched Lens Array (SLA). The laser-receiving version of SLA is being developed for space power applications when or where sunlight is not available (e.g., the eternally dark lunar polar craters). The laser-receiving SLA can efficiently collect and convert beamed laser power from orbiting spacecraft or other sources (e.g., solar-powered lasers on the permanently illuminated ridges of lunar polar craters). A dual-use version of SLA can produce power from sunlight during sunlit portions of the mission, and from beamed laser light during dark portions of the mission. SLA minimizes the cost and mass of photovoltaic cells by using gossamer-like Fresnel lenses to capture and focus incoming light (solar or laser) by a factor of 8.5X, thereby providing a cost-effective, ultra-light space power system.

  1. Visible-light-induced water splitting on a chip

    NARCIS (Netherlands)

    Zoontjes, Michel Gerardus Cornelis

    2015-01-01

    In this thesis, a photoelectrochemical water splitting cell concept is discussed, based on a combination of semiconductors comprising a Z-scheme. The motivation for the development of the cell is that in the future a transition will take place from a fossil fuel-based economy, to an economy based on

  2. Adjusting soil water balance calculations for light rainfall, dew, and fog.

    Science.gov (United States)

    Snyder, R. L.; Spano, D.; Moratiel, R.

    2012-04-01

    The main sources of water for an irrigated crop include irrigation applications, precipitation, water tables, fog interception, and dew formation. For a well-drained soil in a climate where there are a few events of fog, dew, or light rainfall, computing a water balance is relatively easy, but it is complicated in regions characterized by considerable events of fog, dew and light rainfall. In these regions, growers are hesitant to use ET-Based scheduling because the cumulative crop evapotranspiration is often considerably higher than the soil water depletion. We will present a simple and practical procedure to estimate the contribution of fog interception, dew, and light rainfall to daily crop evapotranspiration in California and to show how to use the information to improve water balance calculations for efficient water use in irrigation. It is assumed that the relationship between normalized hourly ETo and time of the day is similar to the relationship between normalized hourly ETc and time of the day. We can describe the change in soil water depletion (ΔDSW) on that day as: ΔDsw =ETc x F where F is the fraction of ETc coming from the soil, and F is determined using the expression: F = --1--- 1+ e(t-11.265.5) Where t is the approximate local standard time in hours when the crop dries. This simple method improves water balance scheduling and the adoption of the ET-based scheduling method in microclimates where fog, dew, and light rainfall are common.

  3. Techniques for the conversion to carbon dioxide of oxygen from dissolved sulfate in thermal waters

    Science.gov (United States)

    Nehring, N.L.; Bowen, P.A.; Truesdell, A.H.

    1977-01-01

    The fractionation of oxygen isotopes between dissolved sulfate ions and water provides a useful geothermometer for geothermal waters. The oxygen isotope composition of dissolved sulfate may also be used to indicate the source of the sulfate and processes of formation. The methods described here for separation, purification and reduction of sulfate to prepare carbon dioxide for mass spectrometric analysis are modifications of methods by Rafter (1967), Mizutani (1971), Sakai and Krouse (1971), and Mizutani and Rafter (1969). ?? 1976.

  4. High-quality elliptical iron glycolate nanosheets: selective synthesis and chemical conversion into FexOy nanorings, porous nanosheets, and nanochains with enhanced visible-light photocatalytic activity

    Science.gov (United States)

    Tong, Guoxiu; Liu, Yun; Wu, Tong; Ye, Yucheng; Tong, Chaoli

    2015-10-01

    This paper describes an original and facile polyol-mediated solvothermal synthesis of elliptical iron glycolate nanosheets (IGNSs) combined with precursor thermal conversion into γ-Fe2O3 and α-Fe2O3/γ-Fe2O3 porous nanosheets (PNSs), α-Fe2O3 nanochains (NCs), and elliptical Fe3O4 nanorings (NRs). The IGNSs were produced via the oxidation-reduction and co-precipitation reactions in the presence of iron(iii) salts, ethylene glycol, polyethylene glycol, and ethylenediamine. Control over Fe3+ concentration, temperature, and time can considerably modulate the size and phase of the products. The IGNSs can be transformed to γ-Fe2O3 and α-Fe2O3/γ-Fe2O3 PNSs, α-Fe2O3 NCs, and elliptical Fe3O4 NRs by heat treatment under various annealing temperatures and ambiences. The PNSs and NCs exhibited high soft magnetic properties and coercivity, respectively. Visible-light photocatalytic activity toward RhB in the presence of H2O2 by PNSs and NCs was phase-, SBET, size-, porosity-, and local structure-dependent, following the order: α-Fe2O3 NCs > α-Fe2O3/γ-Fe2O3 PNSs > γ-Fe2O3 PNSs > IGNSs. In particular, α-Fe2O3/γ-Fe2O3 PNSs possessed significantly enhanced photocatalytic activity with good recyclability and could be conveniently separated by an applied magnetic field because of high magnetization. We believe that the as-prepared α-Fe2O3/γ-Fe2O3 PNSs have potential practical use in waste water treatment and microwave absorption.This paper describes an original and facile polyol-mediated solvothermal synthesis of elliptical iron glycolate nanosheets (IGNSs) combined with precursor thermal conversion into γ-Fe2O3 and α-Fe2O3/γ-Fe2O3 porous nanosheets (PNSs), α-Fe2O3 nanochains (NCs), and elliptical Fe3O4 nanorings (NRs). The IGNSs were produced via the oxidation-reduction and co-precipitation reactions in the presence of iron(iii) salts, ethylene glycol, polyethylene glycol, and ethylenediamine. Control over Fe3+ concentration, temperature, and time can

  5. Research and Manufacturing of High Power Integrated LED Light Conversion Source%大功率集成LED光转换光源的研制

    Institute of Scientific and Technical Information of China (English)

    李茂龙; 隋玉龙; 吴粤宁; 戴兴建

    2012-01-01

    介绍了一种应用远程激发技术的大功率集成LED光转换光源,通过使用固晶区无绝缘层的镜面铝基板进行集成封装蓝光LED光源,即COB光源.所制蓝光光源与远程激发荧光粉模块结合制成LED光转换光源.利用镜面铝基板的高导热系数,解决多种LED封装形式下芯片点亮温度过高、光源衰减快的问题.采用LED荧光高分子模块与蓝光芯片分离结合的远程激发技术制成白光光源,解决荧光粉分布不均、热老化、色偏移问题.通过与传统粉胶封装方式制得的大功率集成LED器件比较测试,该种光源具有防眩光、光色均匀度高、长寿命、节能和环保的优点,从而具有更广泛的用途.%A high-power integrated LED light conversion light source applying remote excitation technique was introduced. The blue LED that is COB package blue LED through mirror-free aluminum plate without insulating layer in solid crystal area to develop to LED light conversion source with remote excited phosphor module. The problems of lots of package chip light temperature too high and light attenuation too fast were solved by using high thermal conductivity coefficient of mirror aluminum plate. And it is an effective solution to the issue of uneven distribution of phosphor, thermal aging of phosphor and color offset. Compared with traditional phosphor and resin glue package pattern, the high-power LED has the advantages of anti-dazzle, high light color degree of homogeneity, long life, energy saving, and environmental protection, so as to achieve more widely uses.

  6. Operational limitations of light water reactors relating to fuel performance

    Energy Technology Data Exchange (ETDEWEB)

    Cheng, H S

    1976-07-01

    General aspects of fuel performance for typical Boiling and Pressurized Water Reactors are presented. Emphasis is placed on fuel failures in order to make clear important operational limitations. A discussion of fuel element designs is first given to provide the background information for the subsequent discussion of several fuel failure modes that have been identified. Fuel failure experiences through December 31, 1974, are summarized. The operational limitations that are required to mitigate the effects of fuel failures are discussed.

  7. Operational limitations of light water reactors relating to fuel performance

    Energy Technology Data Exchange (ETDEWEB)

    Cheng, H S

    1976-07-01

    General aspects of fuel performance for typical Boiling and Pressurized Water Reactors are presented. Emphasis is placed on fuel failures in order to make clear important operational limitations. A discussion of fuel element designs is first given to provide the background information for the subsequent discussion of several fuel failure modes that have been identified. Fuel failure experiences through December 31, 1974, are summarized. The operational limitations that are required to mitigate the effects of fuel failures are discussed.

  8. Inactivation of microalgae in ballast water with pulse intense light treatment.

    Science.gov (United States)

    Feng, Daolun; Shi, Jidong; Sun, Dan

    2015-01-15

    The exotic emission of ballast water has threatened the coastal ecological environment and people's health in many countries. This paper firstly introduces pulse intense light to treat ballast water. 99.9 ± 0.09% inactivation of Heterosigma akashiwo and 99.9 ± 0.16% inactivation of Pyramimonas sp. are observed under treatment conditions of 350 V pulse peak voltage, 15 Hz pulse frequency, 5 ms pulse width and 1.78 L/min flow rate. The energy consumption of the self-designed pulse intense light treatment system is about 2.90-5.14 times higher than that of the typical commercial UV ballast water treatment system. The results indicate that pulse intense light is an effective technique for ballast water treatment, while it is only a competitive one when drastic decreasing in energy consumption is accomplished. Copyright © 2014 Elsevier Ltd. All rights reserved.

  9. Theoretical insight into the conversion of xylose to furfural in the gas phase and water.

    Science.gov (United States)

    Wang, Meng; Liu, Chao; Li, Qibin; Xu, Xiaoxiao

    2015-11-01

    Furfural (FF) is a valuable ring-containing organic compound in the decomposition of xylose and can be produced massively in hydrothermal condition. In this study, density functional theory (DFT) methods are employed to investigate the formation mechanism of FF from xylose and the solvent effects on FF formation. Kinetic and thermodynamic analyses indicate that xylulose could be the intermediate that leads to the formation of FF in the gas phase and water. The formation of xylulose is initiated by a six-membered transition state with energy barriers of 163.6 and 150.8 kJ mol(-1) in the gas phase and water, respectively. It is found that the strong stabilization of the reactants and transition states and the overall energy barriers of formation pathways of FF are reduced in water. The formation of FF is more thermodynamically favored in water compared with that in the gas phase. In addition, the inclusion of an explicit water molecule transforms four-membered transition states of ring-opening reaction, hydrogenation-cyclization, and dehydrations into less distorted six-membered transition states, which leads to the significant reduction of reaction barriers of FF formation.

  10. Petal abscission in rose flowers: effects of water potential, light intensity and light quality

    NARCIS (Netherlands)

    Doorn, van W.G.; Vojinovic, A.

    1996-01-01

    Petal abscission was studied in roses (Rosa hybrida L.), cvs. Korflapei (trade name Frisco), Sweet Promise (Sonia) and Cara Mia (trade name as officially registered cultivar name). Unlike flowers on plants in greenhouses, cut flowers placed in water in the greenhouse produced visible symptoms of wat

  11. Design Considerations for a Water Treatment System Utilizing Ultra-Violet Light Emitting Diodes

    Science.gov (United States)

    2014-03-27

    industry use for UV fluorescent bulb type water disinfection systems (Aquionics, 2013). Shorter wavelength LEDs (240 nm) were shown to be more...is in its infancy and research as it applies to UV water treatment is required to advance knowledge for practical application. This thesis focused...on two subjects. First, the design, fabrication, and operation of a water treatment reaction system utilizing Ultra-Violet ( UV ) Light Emitting

  12. Conversion of Japanese red pine wood (Pinus densiflora) into valuable chemicals under subcritical water conditions.

    Science.gov (United States)

    Asghari, Feridoun Salak; Yoshida, Hiroyuki

    2010-01-11

    A comparative study on the decomposition of Japanese red pine wood under subcritical water conditions in the presence and absence of phosphate buffer was investigated in a batch-type reaction vessel. Since cellulose makes up more than 40-45% of the components found in most wood species, a series of experiments were also carried out using pure cellulose as a model for woody biomass. Several parameters such as temperature and residence time, as well as pH effects, were investigated in detail. The best temperature for decomposition and hydrolysis of pure cellulose was found around 270 degrees C. The effects of the initial pH of the solution which ranged from 1.5 to 6.5 were studied. It was found that the pH has a considerable effect on the hydrolysis and decomposition of the cellulose. Several products in the aqueous phase were identified and quantified. The conditions obtained from the subcritical water treatment of pure cellulose were applied for the Japanese red pine wood chips. As a result, even in the absence of acid catalyst, a large amount of wood sample was hydrolyzed in water; however, by using phosphate buffer at pH 2, there was an increase in the hydrolysis and dissolution of the wood chips. In addition to the water-soluble phase, acetone-soluble and water-acetone-insoluble phases were also isolated after subcritical water treatment (which can be attributed mainly to the degraded lignin, tar, and unreacted wood chips, respectively). The initial wood:acid ratio in the case of reactions catalyzed by phosphate buffer was also investigated. The results showed that this weight ratio can be as high as 3:1 without changing the catalytic activity. The size of the wood chips as one of the most important experimental parameters was also investigated.

  13. Elimination of disinfection byproduct formation potential in reclaimed water during solar light irradiation.

    Science.gov (United States)

    Qian-Yuan, Wu; Chao, Li; Ye, Du; Wen-Long, Wang; Huang, Huang; Hong-Ying, Hu

    2016-05-15

    Ecological storage of reclaimed water in ponds and lakes is widely applied in water reuse. During reclaimed water storage, solar light can degrade pollutants and improve water quality. This study investigated the effects of solar light irradiation on the disinfection byproduct formation potential in reclaimed water, including haloacetonitriles (HANs), trichloronitromethane (TCNM), trihalomethanes (THMs), haloketones (HKs) and chloral hydrate (CH). Natural solar light significantly decreased the formation potential of HANs, TCNM, and HKs in reclaimed water, but had a limited effect on the formation potential of THMs and CH. Ultraviolet (UV) light in solar radiation played a dominant role in the decrease of the formation potential of HANs, TCNM and HKs. Among the disinfection byproducts, the removal kinetic constant of dichloroacetonitrile (DCAN) with irradiation dose was much larger than those for dichloropropanone (1,1-DCP), trichloropropanone (1,1,1-TCP) and TCNM. During solar irradiation, fluorescence spectra intensities of reclaimed water also decreased significantly. The removal of tyrosine (Tyr)-like and tryptophan (Trp)-like protein fluorescence spectra intensity volumes was correlated to the decrease in DCAN formation potential. Solar irradiation was demonstrated to degrade Trp, Tyr and their DCAN formation potential. The photolysis products of Trp after solar irradiation were detected as kynurenine and tryptamine, which had chloroform, CH and DCAN formation potential lower than those of Trp.

  14. Impacts of Forest to Urban Land Conversion and ENSO Phase on Water Quality of a Public Water Supply Reservoir

    Directory of Open Access Journals (Sweden)

    Emile Elias

    2016-01-01

    Full Text Available We used coupled watershed and reservoir models to evaluate the impacts of deforestation and l Niño Southern Oscillation (ENSO phase on drinking water quality. Source water total organic carbon (TOC is especially important due to the potential for production of carcinogenic disinfection byproducts (DBPs. The Environmental Fluid Dynamics Code (EFDC reservoir model is used to evaluate the difference between daily pre- and post- urbanization nutrients and TOC concentration. Post-disturbance (future reservoir total nitrogen (TN, total phosphorus (TP, TOC and chlorophyll-a concentrations were found to be higher than pre-urbanization (base concentrations (p < 0.05. Predicted future median TOC concentration was 1.1 mg·L−1 (41% higher than base TOC concentration at the source water intake. Simulations show that prior to urbanization, additional water treatment was necessary on 47% of the days between May and October. However, following simulated urbanization, additional drinking water treatment might be continuously necessary between May and October. One of six ENSO indices is weakly negatively correlated with the measured reservoir TOC indicating there may be higher TOC concentrations in times of lower streamflow (La Niña. There is a positive significant correlation between simulated TN and TP concentrations with ENSO suggesting higher concentrations during El Niño.

  15. Computational study of power conversion and luminous efficiency performance for semiconductor quantum dot nanophosphors on light-emitting diodes.

    Science.gov (United States)

    Erdem, Talha; Nizamoglu, Sedat; Demir, Hilmi Volkan

    2012-01-30

    We present power conversion efficiency (PCE) and luminous efficiency (LE) performance levels of high photometric quality white LEDs integrated with quantum dots (QDs) achieving an averaged color rendering index of ≥90 (with R9 at least 70), a luminous efficacy of optical radiation of ≥380 lm/W(opt) a correlated color temperature of ≤4000 K, and a chromaticity difference dC quantum efficiency of 43%, 61%, and 80% in film, respectively, using state-of-the-art blue LED chips (81.3% PCE). Furthermore, our computational analyses suggest that QD-LEDs can be both photometrically and electrically more efficient than phosphor based LEDs when state-of-the-art QDs are used.

  16. Catalytic conversion of light alkanes-proof-of-concept stage -- Phase 6. Final report, February 1--October 31, 1994

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1994-12-31

    During the course of the first three years of the Cooperative Agreement, the authors uncovered a family of metal perhaloporphyrin complexes which had unprecedented activity for the selective air-oxidation of light alkanes to alcohols. The reactivity of light hydrocarbon substrates with air or oxygen was in the order: isobutane > propane > ethane > methane, in accord with their homolytic bond dissociation energies. Isobutane was so reactive that the proof-of-concept stage of a process for producing tert-butyl alcohol from isobutane was begun (Phase 5). It was proposed that as more active catalytic systems were developed (Phases 4, 6), propane, then ethane and finally methane oxidations will move into this stage (Phases 7 through 9). As of this writing, however, the program has been terminated during the later stages of Phase 5 and 6 so that further work is not anticipated. 72 refs.

  17. Characterization of 14C in Swedish light water reactors.

    Science.gov (United States)

    Magnusson, Asa; Aronsson, Per-Olof; Lundgren, Klas; Stenström, Kristina

    2008-08-01

    This paper presents the results of a 4-y investigation of 14C in different waste streams of both boiling water reactors (BWRs) and pressurized water reactors (PWRs). Due to the potential impact of 14C on human health, minimizing waste and releases from the nuclear power industry is of considerable interest. The experimental data and conclusions may be implemented to select appropriate waste management strategies and practices at reactor units and disposal facilities. Organic and inorganic 14C in spent ion exchange resins, process water systems, ejector off-gas and replaced steam generator tubes were analyzed using a recently developed extraction method. Separate analysis of the chemical species is of importance in order to model and predict the fate of 14C within process systems as well as in dose calculations for disposal facilities. By combining the results of this investigation with newly calculated production rates, mass balance assessments were made of the 14C originating from production in the coolant. Of the 14C formed in the coolant of BWRs, 0.6-0.8% was found to be accumulated in the ion exchange resins (core-specific production rate in the coolant of a 2,500 MWth BWR calculated to be 580 GBq GW(e)(-1) y(-1)). The corresponding value for PWRs was 6-10% (production rate in a 2,775 MWth PWR calculated to be 350 GBq GW(e)(-1) y(-1)). The 14C released with liquid discharges was found to be insignificant, constituting less than 0.5% of the production in the coolant. The stack releases, routinely measured at the power plants, were found to correspond to 60-155% of the calculated coolant production, with large variations between the BWR units.

  18. Effects of hot-water extraction on the thermochemical conversion of shrub willow via fast pyrolysis

    Science.gov (United States)

    Hot-water extraction (TM) (HWE) is a pretreatment technology designed to facilitate the subsequent hydrolysis of cellulose by removing the majority of the hemicellulose and ash content from the solid biomass. The HWE process generates salable sugars and other products as part of the process. The bio...

  19. High throughput screening of photocatalytic conversion of pharmaceutical contaminants in water

    NARCIS (Netherlands)

    Romao, Joana; Barata, David; Ribeiro, Nelson; Habibovic, Pamela; Fernandes, Hugo; Mul, Guido

    2017-01-01

    The susceptibility for photon-induced degradation of over 800 pharmaceutical compounds present in the LOPAC1280 library, was analyzed by UV/Vis spectroscopy in the absence or presence of TiO2 P25 in water. In general, few compounds were effectively degraded in the absence of the TiO2 photocatalyst

  20. Water-soluble phosphine-protected Au9 clusters: Electronic structures and nuclearity conversion via phase transfer

    Science.gov (United States)

    Yao, Hiroshi; Tsubota, Shuhei

    2017-08-01

    In this article, isolation, exploration of electronic structures, and nuclearity conversion of water-soluble triphenylphosphine monosulfonate (TPPS)-protected nonagold (Au9) clusters are outlined. The Au9 clusters are obtained by the reduction of solutions containing TPPS and HAuCl4 and subsequent electrophoretic fractionation. Mass spectrometry and elemental analysis reveal the formation of [Au9(TPPS)8]5- nonagold cluster. UV-vis absorption and magnetic circular dichroism (MCD) spectra of aqueous [Au9(TPPS)8]5- are quite similar to those of [Au9(PPh3)8]3+ in organic solvent, so the solution-phase structures are likely similar for both systems. Simultaneous deconvolution analysis of absorption and MCD spectra demonstrates the presence of some weak electronic transitions that are essentially unresolved in the UV-vis absorption. Quantum chemical calculations for a model compound [Au9(pH3)8]3+ show that the possible (solution-phase) skeletal structure of the nonagold cluster has D2h core symmetry rather than C4-symmetrical centered crown conformation, which is known as the crystal form of the Au9 compound. Moreover, we find a new nuclearity conversion route from Au9 to Au8; that is, phase transfer of aqueous [Au9(TPPS)8]5- into chloroform using tetraoctylammonium bromide yields [Au8(TPPS)8]6- clusters in the absence of excess phosphine.

  1. Polder Effects on Sediment-to-Soil Conversion: Water Table, Residual Available Water Capacity, and Salt Stress Interdependence

    Directory of Open Access Journals (Sweden)

    Raymond Tojo Radimy

    2013-01-01

    Full Text Available The French Atlantic marshlands, reclaimed since the Middle Age, have been successively used for extensive grazing and more recently for cereal cultivation from 1970. The soils have acquired specific properties which have been induced by the successive reclaiming and drainage works and by the response of the clay dominant primary sediments, that is, structure, moisture, and salinity profiles. Based on the whole survey of the Marais Poitevin and Marais de Rochefort and in order to explain the mechanisms of marsh soil behavior, the work focuses on two typical spots: an undrained grassland since at least 1964 and a drained cereal cultivated field. The structure-hydromechanical profiles relationships have been established thanks to the clay matrix shrinkage curve. They are confronted to the hydraulic functioning including the fresh-to-salt water transfers and to the recording of tensiometer profiles. The CE1/5 profiles supply the water geochemical and geophysical data by their better accuracy. Associated to the available water capacity calculation they allow the representation of the parallel evolution of the residual available water capacity profiles and salinity profiles according to the plant growing and rooting from the mesophile systems of grassland to the hygrophile systems of drained fields.

  2. Improved Light Conversion Efficiency Of Dye-Sensitized Solar Cell By Dispersing Submicron-Sized Granules Into The Nano-Sized TiO2 Layer

    Directory of Open Access Journals (Sweden)

    Song S.A.

    2015-06-01

    Full Text Available In this work, TiO2 nanoparticles and submicron-sized granules were synthesized by a hydrothermal method and spray pyrolysis, respectively. Submicron-sized granules were dispersed into the nano-sized TiO2 layer to improve the light conversion efficiency. Granules showed better light scattering, but lower in terms of the dye-loading quantity and recombination resistance compared with nanoparticles. Consequently, the nano-sized TiO2 layer had higher cell efficiency than the granulized TiO2 layer. When dispersed granules into the nanoparticle layer, the light scattering was enhanced without the loss of dye-loading quantities. The dispersion of granulized TiO2 led to increase the cell efficiency up to 6.51%, which was about 5.2 % higher than that of the electrode consisting of only TiO2 nanoparticles. Finally, the optimal hydrothermal temperature and dispersing quantity of granules were found to be 200°C and 20 wt%, respectively.

  3. Down-conversion phosphors as noble-metal-free co-catalyst in ZnO for efficient visible light photocatalysis

    Science.gov (United States)

    Chu, Haipeng; Liu, Xinjuan; Liu, Jiaqing; Lei, Wenyan; Li, Jinliang; Wu, Tianyang; Li, Ping; Li, Huili; Pan, Likun

    2017-01-01

    Exploring novel visible light responsive photocatalysts is one of greatly significant issues from the viewpoint of using solar energy. Here we report the yellow-orange emitting α-Si3N4-doped Lu3Al5O12:Ce3+ (Lu3Al5-xSixO12-xNx:Ce3+) phosphors as a noble-metal-free co-catalyst for enhanced visible light photocatalytic activity of ZnO. The results show that ZnO-Lu3Al5-xSixO12-xNx:Ce3+ hybrid photocatalysts using a fast microwave-assisted approach exhibits a 91% methylene blue (MB) degradation under visible light irradiation at 240 min, which evidence the synergistic effect of ZnO and Lu3Al5-xSixO12-xNx:Ce3+ that suppress the rate of charge recombination and increase the self-sensitized degradation of MB. ZnO-down conversion phosphors can be envisaged as potential candidate in environmental engineering and solar energy applications.

  4. COMSORS: A light water reactor chemical core catcher

    Energy Technology Data Exchange (ETDEWEB)

    Forsberg, C.W.; Parker, G.W.; Rudolph, J.C.; Osborne-Lee, I.W. [Oak Ridge National Lab., TN (United States). Chemical Technology Div.; Kenton, M.A. [Creare Inc., Hanover, NH (United States)

    1997-02-24

    The Core-Melt Source Reduction System (COMSORS) is a new approach to terminate lightwater reactor (LWR) core-melt accidents and ensure containment integrity. A special dissolution glass made of lead oxide (PbO) and boron oxide (B{sub 2}O{sub 3}) is placed under the reactor vessel. If molten core debris is released onto the glass, the following sequence happens: (1) the glass absorbs decay heat as its temperature increases and the glass softens; (2) the core debris dissolves into the molten glass; (3) molten glass convective currents create a homogeneous high-level waste (HLW) glass; (4) the molten glass spreads into a wider pool, distributing the heat for removal by radiation to the reactor cavity above or transfer to water on top of the molten glass; and (5) the glass solidifies as increased surface cooling area and decreasing radioactive decay heat generation allows heat removal to exceed heat generation.

  5. Visible Light Enabled Photocatalytic Splitting of Water over Spatially Isolated Semiconductors Supported Mesoporous Materials

    Science.gov (United States)

    Peng, Rui

    Hydrogen generation from photocatalytic splitting of water is an ideal scenario that possesses promise for the sustainable development of human society and the establishment of the ultimate "green," infinitely renewable energy system. This work contains a series of novel photocatalytic systems in which the photoactive chromophores and/or the co-catalysts were incorporated into highly periodically cubic-phased MCM-48 mesoporous materials to achieve significantly higher photocatalytic efficiencies compared with conventional semiconductor photocatalysts. Cubic-phased MCM-48 mesoporous materials were chosen as supports to accommodate the photoactive species throughout the entire work. Several unique and iconic properties of these materials, such as large surface area, highly uniform mesoscale pores arrayed in a long-range periodicity, and an interconnected network of three-dimensional sets of pores that were recognized as positive parameters facilitated the photogenerated charge transfer and promoted the photocatalytic performance of the encapsulated photoactive species. It was validated that in the CdS/TiO2-incorporated MCM-48 photocatalytic system, the solar hydrogen conversion efficiency was prevalently governed by the photogenerated electron injection efficiency from the CdS conduction band to that of TiO2. The use of MCM-48 mesoporous host materials enabled the high and even dispersion of both CdS and TiO 2 so that the intimate and sufficient contact between CdS and TiO 2 was realized. In addition, with the presence of both TiO2 and MCM-48 mesoporous support, the photostability of CdS species was dramatically enhanced compared with that of bare CdS or CdS-incorporated MCM-48 photocatalysts. In advance, by loading the RuO2 co-catalyst into the CdS/TiO 2-incorporated MCM-48 photocatalytic system, the photocatalytic splitting of pure water to generate both hydrogen and oxygen under visible light illumination was achieved. In the various Pd-assisted, TiO2-incorporated

  6. Conversion of water consumption of a single tree and a forest stand of Populus euphratica

    Institute of Scientific and Technical Information of China (English)

    ZHANG Xiao-you; MENG Tong-tong; KANG Er-si

    2008-01-01

    Our study dear with the determination of sapwood sap flow of a single Populus euphratica tree by heat pulse technique and the calculation of water consumption of an entire forest stand, given the correlation between sap flow and sapwood area of P. euphratica. The relation between diameter at breast height (DBH) and sapwood area constitutes a powerful model; these variables are highly correlated. By means of an analysis of DBH in the sample plot, the distribution of the sapwood area of the forest land was obtained and the water consumption of this P. euphratica forest, in the lower reaches of the Heihe River, calculated as 214.9 mm by standard specific conductivity of the sample tree.

  7. Direct Conversion of Cellulose into Ethyl Lactate in Supercritical Ethanol-Water Solutions.

    Science.gov (United States)

    Yang, Lisha; Yang, Xiaokun; Tian, Elli; Lin, Hongfei

    2016-01-08

    Biomass-derived ethyl lactate is a green solvent with a growing market as the replacement for petroleum-derived toxic organic solvents. Here we report, for the first time, the production of ethyl lactate directly from cellulose with the mesoporous Zr-SBA-15 silicate catalyst in a supercritical mixture of ethanol and water. The relatively strong Lewis and weak Brønsted acid sites on the catalyst, as well as the surface hydrophobicity, were beneficial to the reaction and led to synergy during consecutive reactions, such as depolymerization, retro-aldol condensation, and esterification. Under the optimum reaction conditions, ∼33 % yield of ethyl lactate was produced from cellulose with the Zr-SBA-15 catalyst at 260 °C in supercritical 95:5 (w/w) ethanol/water.

  8. Supercritical water oxidation of Quinazoline: Effects of conversion parameters and reaction mechanism.

    Science.gov (United States)

    Gong, Yanmeng; Guo, Yang; Wang, Shuzhong; Song, Wenhan

    2016-09-01

    The supercritical water oxidation reaction of quinazoline and a set of related reaction products were investigated in batch reactors by varying the temperature (T, 400-600 °C), time (t, 0-400 s), water density (ρ, 70.79-166.28  kg m(-3)) and oxidation coefficient (OC, 0-4.0). The TOC removal efficiency (CRE) increased significantly as the OC increased, whereas this effect was very limited at high OC (>2.0). Lack of oxygen resulted in low CRE and TN removal efficiency (NRE), also cause coke-formation, and giving high yield of NH3 and nitrogenous organic intermediates. Prolonging reaction time did not provide an appreciable improvement on CRE but remarkably increased NRE at temperature higher than 500 °C. Pyrimidines and pyridines as the nitrogenous intermediates were largely found in GC-MS spectrum. Polymerization among benzene, phenyl radical and benzyl radical played important roles in the formation of PAHs, such as naphthalene, biphenyl, phenanthrene. These collective results showed how the yield of intermediate products responded to changes in the process variables, which permitted the development of a potential reaction network for supercritical water oxidation of quinazoline.

  9. The lantern shark's light switch: turning shallow water crypsis into midwater camouflage.

    Science.gov (United States)

    Claes, Julien M; Mallefet, Jérôme

    2010-10-23

    Bioluminescence is a common feature in the permanent darkness of the deep-sea. In fishes, light is emitted by organs containing either photogenic cells (intrinsic photophores), which are under direct nervous control, or symbiotic luminous bacteria (symbiotic photophores), whose light is controlled by secondary means such as mechanical occlusion or physiological suppression. The intrinsic photophores of the lantern shark Etmopterus spinax were recently shown as an exception to this rule since they appear to be under hormonal control. Here, we show that hormones operate what amounts to a unique light switch, by acting on a chromatophore iris, which regulates light emission by pigment translocation. This result strongly suggests that this shark's luminescence control originates from the mechanism for physiological colour change found in shallow water sharks that also involves hormonally controlled chromatophores: the lantern shark would have turned the initial shallow water crypsis mechanism into a midwater luminous camouflage, more efficient in the deep-sea environment.

  10. Countermeasures to Microbiofouling in Simulated Ocean Thermal Energy Conversion Heat Exchangers with Surface and Deep Ocean Waters in Hawaii

    Science.gov (United States)

    Berger, Leslie Ralph; Berger, Joyce A.

    1986-01-01

    Countermeasures to biofouling in simulated ocean thermal energy conversion heat exchangers have been studied in single-pass flow systems, using cold deep and warm surface ocean waters off the island of Hawaii. Manual brushing of the loops after free fouling periods removed most of the biofouling material. However, over a 2-year period a tenacious film formed. Daily free passage of sponge rubber balls through the tubing only removed the loose surface biofouling layer and was inadequate as a countermeasure in both titanium and aluminum alloy tubes. Chlorination at 0.05, 0.07, and 0.10 mg liter-1 for 1 h day-1 lowered biofouling rates. Only at 0.10 mg liter-1 was chlorine adequate over a 1-year period to keep film formation and heat transfer resistance from rising above the maximum tolerated values. Lower chlorination regimens led to the buildup of uneven or patchy films which produced increased flow turbulence. The result was lower heat transfer resistance values which did not correlate with the amount of biofouling. Surfaces which were let foul and then treated with intermittent or continuous chlorination at 0.10 mg of chlorine or less per liter were only partially or unevenly cleaned, although heat transfer measurements did not indicate that fact. It took continuous chlorination at 0.25 mg liter-1 to bring the heat transfer resistance to zero and eliminate the fouling layer. Biofouling in deep cold seawater was much slower than in the warm surface waters. Tubing in one stainless-steel loop had a barely detectable fouling layer after 1 year in flow. With aluminum alloys sufficient corrosion and biofouling material accumulated to require that some fouling coutermeasure be used in long-term operation of an ocean thermal energy conversion plant. Images PMID:16347076

  11. A role for calcium hydroxide and dolomite in water: acceleration of the reaction under ultraviolet light.

    Science.gov (United States)

    Nagase, Hiroyasu; Tsujino, Hidekazu; Kurihara, Daisuke; Saito, Hiroshi; Kawase, Masaya

    2014-04-01

    Organic environmental pollutants are now being detected with remarkably high frequency in the aquatic environment. Photodegradation by ultraviolet light is sometimes used as a method for removing organic chemicals from water; however, this method is relatively inefficient because of the low degradation rates involved, and more efficient methods are under development. Here we show that the removal of various organic pollutants can be assisted by calcined dolomite in aqueous solution under irradiation with ultraviolet light. It was possible to achieve substantial removal of bisphenol A, chlorophenols, alkylphenols, 1-naphthol and 17β-estradiol. The major component of dolomite responsible for the removal was calcium hydroxide. Our results demonstrate that the use of calcium hydroxide with ultraviolet light irradiation can be a very effective method of rapidly removing organic environmental pollutants from water. This is a new role for calcium hydroxide and dolomite in water treatment.

  12. Structural and thermal transitions during the conversion from native to granular cold-water swelling maize starch.

    Science.gov (United States)

    Dries, D M; Gomand, S V; Goderis, B; Delcour, J A

    2014-12-19

    Native maize starch was gradually converted into granular cold-water swelling starch (GCWSS) by aqueous ethanol treatments at elevated temperatures. At a treatment temperature of 95°C, decreasing ethanol concentrations from 68 to 48% (v/v) led to decreased post-treatment gelatinization enthalpies in excess water, reflecting remaining original A-type crystals. Concomitantly to native A-type crystal melting, VH-type crystals appeared. At an ethanol concentration of 48%, a granular cold-water swelling maize starch was successfully produced. All crystals in its intact granules were of the VH-type and appeared birefringent when studied in ethanol under polarized light. Removal of all residual solvent by high temperature drying did not influence swelling power, proving that a high temperature drying step is not necessary to induce cold-water swelling capacity. Based on in situ calorimetric measurements, the thermal requirements to produce GCWSS from different ethanol:water mixtures were elucidated. This work is the first to demonstrate that the amylose fraction contributes almost exclusively to VH-type crystal formation in GCWSS.

  13. Degree of conversion of micro-hybrid, nano-hybrid and Ormocer composites using LED and QTH light-curing units

    Directory of Open Access Journals (Sweden)

    Seied Mostafa Fatemi

    2012-01-01

    Full Text Available Background and Aims: The aim of this study was to measure the degree of conversion (DC of three types of composite resins (micro-hybrid, nano-hybrid and Ormocer with different light curing units (LED LCU and QTH LCU in two depths.Materials and Methods: Three commercially available dental resin composites were used in this study: (Tetric Ceram, Ivoclar Vivadent, Liechtenstein-A2 shade, (Tetric Evoceram, Ivoclar Vivadent, Liechtenstein-A2 shade, (Ceram X, Dentsply, Germany-M2 shade. Specimens were divided into two groups, 5 specimens were photo-activated by QTH unit (Coltolux 75-Colten and the other five specimens were cured by LED (Demi-Kerr. Then each specimen was sectioned at the top surface and at 2-mm depth. The DC was measured by FT-IR(Bruker-tensor 27. The data were analyzed by 3-way ANOVA test.Results: There was significant difference between tested composite resins (P<0.001. The results of top surfaces were significantly different from those observed at 2-mm depth (P<0.001. The type of curing unit affected the polymerization of Ceram X resin composite.Conclusion: This study showed a significant difference in the degree of conversion in different thicknesses within three groups of resin composites.

  14. Hydrothermal conversion of biomass

    NARCIS (Netherlands)

    Knezevic, Dragan

    2009-01-01

    This thesis presents research of hydrothermal conversion of biomass (HTC). In this process, hot compressed water (subcritical water) is used as the reaction medium. Therefore this technique is suitable for conversion of wet biomass/ waste streams. By working at high pressures, the evaporation of wat

  15. 10 CFR 50.46 - Acceptance criteria for emergency core cooling systems for light-water nuclear power reactors.

    Science.gov (United States)

    2010-01-01

    ... generated from the chemical reaction of the cladding with water or steam shall not exceed 0.01 times the... light-water nuclear power reactors. 50.46 Section 50.46 Energy NUCLEAR REGULATORY COMMISSION DOMESTIC... reactors. (a)(1)(i) Each boiling or pressurized light-water nuclear power reactor fueled with uranium oxide...

  16. Ocean thermal energy conversion cold water pipe preliminary design project. Appendices to final report

    Energy Technology Data Exchange (ETDEWEB)

    1979-11-20

    NOAA/DOE has selected three concepts for a baseline design of the cold water pipe (CWP) for OTEC plants: (1) a FRP CWP of sandwich wall construction suspended from the Applied Physical Laboratory/John Hopkins University (APL/JHU) barge at a site 200 miles east of the coast of Brazil using a horizontal deployment scheme; (2) an elastomer CWP suspended from the APL/JHU barge off the southeast coast of Puerto Rico using either a horizontal or vertical deployment scheme; and (3) a polyethylene CWP (single or multiple pipe) suspended from the Gibbs and Cox spar at the Puerto Rico site using a horizontal deployment scheme. TRW has developed a baseline design for each of these configurations. This volume of the report includes the following appendices: (A) fiberglass reinforced plastic cold water pipe (specification and drawingss); (B) specification for polyethylene CWP; (C) elastomer pipe drawings; (D) drawings for OTEC 10/40 hull/CWP transitions; (E) structural design of OTEC 10/40 CWP support and CWP transitions; (F) universal transition joint for CWP; (G) dynamic spherical seal of CWP; (H) at-sea deployment loads - surface towing loads; (I) OTEC 10/40 CWP deployment up-ending loads; (J) cost estimates for OTEC 10/40 hull/CWP transitions; and (K) OTEC 10/40 CWP deployment scenario and cost estimate. (WHK)

  17. The effect of alkali on the product distribution from black liquor conversion under supercritical water.

    Science.gov (United States)

    Hawangchu, Y; Atong, D; Sricharoenchaikul, V

    2017-07-01

    Lignin in chemical pulping waste, or black liquor (BL), can be converted into various products via supercritical water gasification (SCWG). However, the inherited alkaline contents from the pulping chemicals may affect the product yields and properties. In this research, the influence of the residual alkali on the product distribution via SCWG of soda BL and kraft BL was evaluated. The SCWG was performed in a batch quartz reactor for 10 min at various temperatures (673, 773 and 873 K) and pressures (250, 300 and 400 bar). The highest hydrogen (H2) production occurred at 873 K for the soda BL. The water-gas shift reaction with sodium ions played an important part in the H2 production, while only small amounts of methane and carbon monoxide were detected. Hydrocarbons, carboxylic acids and esters were the dominant substrates in the liquid products, which denoted the potential of this method for bond cleaving of the lignin macromolecule. As a result, BL, which typically contains alkali salt, was an appropriate feedstock for the SCWG reaction to produce renewable fuel. This method not only has a positive influence on the generation of value added products from highly corrosive waste but also helps avoid some technical problems commonly encountered with direct firing in a recovery boiler.

  18. Combination of visible-light responsive heterogeneous and homogeneous photocatalysts for water oxidation.

    Science.gov (United States)

    Fukuzumi, Shunichi; Kato, Satoshi; Suenobu, Tomoyoshi

    2011-10-28

    Bismuth vanadate (BiVO(4)), which is a visible-light responsive heterogeneous photocatalyst, was combined with homogeneous ruthenium complexes to increase the overall photocatalytic reactivity for water oxidation with a one-electron oxidant, [Co(III)(NH(3))(5)Cl](2+). Photoinduced electron transfer from the excited state of ruthenium(II) complexes to [Co(III)(NH(3))(5)Cl](2+) affords ruthenium(III) complexes which can oxidize water to oxygen with BiVO(4) under visible light irradiation.

  19. Light-Driven Overall Water Splitting Enabled by a Photo-Dember Effect Realized on 3D Plasmonic Structures.

    Science.gov (United States)

    Chen, Min; Gu, Jiajun; Sun, Cheng; Zhao, Yixin; Zhang, Ruoxi; You, Xinyuan; Liu, Qinglei; Zhang, Wang; Su, Yishi; Su, Huilan; Zhang, Di

    2016-07-26

    Photoelectric conversion driven by sunlight has a broad range of energy/environmental applications (e.g., in solar cells and water splitting). However, difficulties are encountered in the separation of photoexcited charges. Here, we realize a long-range (∼1.5 μm period) electric polarization via asymmetric localization of surface plasmons on a three-dimensional silver structure (3D-Ag). This visible-light-responsive effect-the photo-Dember effect, can be analogous to the thermoelectric effect, in which hot carriers are thermally generated instead of being photogenerated. The induced electric field can efficiently separate photogenerated charges, enabling sunlight-driven overall water splitting on a series of dopant-free commercial semiconductor particles (i.e., ZnO, CeO2, TiO2, and WO3) once they are combined with the 3D-Ag substrate. These photocatalytic processes can last over 30 h on 3D-Ag+ZnO, 3D-Ag+CeO2, and 3D-Ag+TiO2, thus demonstrating good catalytic stability for these systems. Using commercial WO3 powder as a reference, the amount of O2 generated with 3D-Ag+CeO2 surpasses even its recently reported counterpart in which sacrificial reagents had to be involved to run half-reactions. This plasmon-mediated charge separation strategy provides an effective way to improve the efficiency of photoelectric energy conversion, which can be useful in photovoltaics and photocatalysis.

  20. Fortification of CdSe quantum dots with graphene oxide. Excited state interactions and light energy conversion.

    Science.gov (United States)

    Lightcap, Ian V; Kamat, Prashant V

    2012-04-25

    Graphene based 2-D carbon nanostructures provide new opportunities to fortify semiconductor based light harvesting assemblies. Electron and energy transfer rates from photoexcited CdSe colloidal quantum dots (QDs) to graphene oxide (GO) and reduced graphene oxide (RGO) were isolated by analysis of excited state deactivation lifetimes as a function of degree of oxidation and charging in (R)GO. Apparent rate constants for energy and electron transfer determined for CdSe-GO composites were 5.5 × 10(8) and 6.7 × 10(8) s(-1), respectively. Additionally, incorporation of GO in colloidal CdSe QD films deposited on conducting glass electrodes was found to enhance the charge separation and electron conduction through the QD film, thus allowing three-dimensional sensitization. Photoanodes assembled from CdSe-graphene composites in quantum dot sensitized solar cells display improved photocurrent response (~150%) over those prepared without GO.

  1. Revealing the ultrafast light-to-matter energy conversion before heat diffusion in a layered Dirac semimetal

    Science.gov (United States)

    Ishida, Y.; Masuda, H.; Sakai, H.; Ishiwata, S.; Shin, S.

    2016-03-01

    There is still no general consensus on how one can describe the out-of-equilibrium phenomena in matter induced by an ultrashort light pulse. We investigate the pulse-induced dynamics in a layered Dirac semimetal SrMnBi2 by pump-and-probe photoemission spectroscopy. At ≲1 ps, the electronic recovery slowed upon increasing the pump power. Such a bottleneck-type slowing is expected in a two-temperature model (TTM) scheme, although opposite trends have been observed to date in graphite and in cuprates. Subsequently, an unconventional power-law cooling took place at ˜100 ps, indicating that spatial heat diffusion is still ill defined at ˜100 ps . We identify that the successive dynamics before the emergence of heat diffusion is a canonical realization of a TTM scheme. Criteria for the applicability of the scheme is also provided.

  2. Rapid water disinfection using vertically aligned MoS2 nanofilms and visible light

    Science.gov (United States)

    Liu, Chong; Kong, Desheng; Hsu, Po-Chun; Yuan, Hongtao; Lee, Hyun-Wook; Liu, Yayuan; Wang, Haotian; Wang, Shuang; Yan, Kai; Lin, Dingchang; Maraccini, Peter A.; Parker, Kimberly M.; Boehm, Alexandria B.; Cui, Yi

    2016-12-01

    Solar energy is readily available in most climates and can be used for water purification. However, solar disinfection of drinking water mostly relies on ultraviolet light, which represents only 4% of the total solar energy, and this leads to a slow treatment speed. Therefore, the development of new materials that can harvest visible light for water disinfection, and so speed up solar water purification, is highly desirable. Here we show that few-layered vertically aligned MoS2 (FLV-MoS2) films can be used to harvest the whole spectrum of visible light (∼50% of solar energy) and achieve highly efficient water disinfection. The bandgap of MoS2 was increased from 1.3 to 1.55 eV by decreasing the domain size, which allowed the FLV-MoS2 to generate reactive oxygen species (ROS) for bacterial inactivation in the water. The FLV-MoS2 showed a ∼15 times better log inactivation efficiency of the indicator bacteria compared with that of bulk MoS2, and a much faster inactivation of bacteria under both visible light and sunlight illumination compared with the widely used TiO2. Moreover, by using a 5 nm copper film on top of the FLV-MoS2 as a catalyst to facilitate electron-hole pair separation and promote the generation of ROS, the disinfection rate was increased a further sixfold. With our approach, we achieved water disinfection of >99.999% inactivation of bacteria in 20 min with a small amount of material (1.6 mg l-1) under simulated visible light.

  3. Review of water intake screening options for coastal water users with recommendations for Ocean Thermal Energy Conversion (OTEC) plants

    Energy Technology Data Exchange (ETDEWEB)

    Thomas, D.L.

    1979-05-01

    The large volumes of water withdrawn at both the warm and cold water intakes of an OTEC plant must be screened to remove organisms and debris which could clog the heat exchangers. The recent literature on screening technology is reviewed. In addition, various screen manufacturers and coastal facilities which use large volumes of seawater were visited to determine the operating experience with present screen technology. Static screens (particularly the Johnson Division, UOP profile wire screen and the Royce Equipment Company carrousel screen) have the potential advantage for OTEC for operating in a completely submerged state and of being cheaper to operate and maintain than traveling screens. However, there is no operational history with these static screens for large intake systems. The most promising traveling screen options for OTEC are the dual flow screens. They offer more screening surface and less head loss than through flow screens of similar size. They also have been operated in seawater for large intake systems. More detailed designs of potential OTEC plants, particurlarly screen wells, conduit and surge tank construction and head losses need to be determined before the best alternative intake screen can be selected. 38 references.

  4. Unassisted photoelectrochemical water splitting exceeding 7% solar-to-hydrogen conversion efficiency using photon recycling

    Science.gov (United States)

    Shi, Xinjian; Jeong, Hokyeong; Oh, Seung Jae; Ma, Ming; Zhang, Kan; Kwon, Jeong; Choi, In Taek; Choi, Il Yong; Kim, Hwan Kyu; Kim, Jong Kyu; Park, Jong Hyeok

    2016-06-01

    Various tandem cell configurations have been reported for highly efficient and spontaneous hydrogen production from photoelectrochemical solar water splitting. However, there is a contradiction between two main requirements of a front photoelectrode in a tandem cell configuration, namely, high transparency and high photocurrent density. Here we demonstrate a simple yet highly effective method to overcome this contradiction by incorporating a hybrid conductive distributed Bragg reflector on the back side of the transparent conducting substrate for the front photoelectrochemical electrode, which functions as both an optical filter and a conductive counter-electrode of the rear dye-sensitized solar cell. The hybrid conductive distributed Bragg reflectors were designed to be transparent to the long-wavelength part of the incident solar spectrum (λ>500 nm) for the rear solar cell, while reflecting the short-wavelength photons (λ<500 nm) which can then be absorbed by the front photoelectrochemical electrode for enhanced photocurrent generation.

  5. New class of photocatalytic materials and a novel principle for efficient water splitting under infrared and visible light: MgB2 as unexpected example.

    Science.gov (United States)

    Kravets, V G; Grigorenko, A N

    2015-11-30

    Water splitting is unanimously recognized as environment friendly, potentially low cost and renewable energy solution based on the future hydrogen economy. Especially appealing is photocatalytic water splitting whereby a suitably chosen catalyst dramatically improves efficiency of the hydrogen production driven by direct sunlight and allows it to happen even at zero driving potential. Here, we suggest a new class of stable photocatalysts and the corresponding principle for catalytic water splitting in which infrared and visible light play the main role in producing the photocurrent and hydrogen. The new class of catalysts - ionic or covalent binary metals with layered graphite-like structures - effectively absorb visible and infrared light facilitating the reaction of water splitting, suppress the inverse reaction of ion recombination by separating ions due to internal electric fields existing near alternating layers, provide the sites for ion trapping of both polarities, and finally deliver the electrons and holes required to generate hydrogen and oxygen gases. As an example, we demonstrate conversion efficiency of ~27% at bias voltage Vbias = 0.5V for magnesium diboride working as a catalyst for photoinduced water splitting. We discuss its advantages over some existing materials and propose the underlying mechanism of photocatalytic water splitting by binary layered metals.

  6. Conversion of Crude Oil to Methane by a Microbial Consortium Enriched From Oil Reservoir Production Waters

    Directory of Open Access Journals (Sweden)

    Carolina eBerdugo-Clavijo

    2014-05-01

    Full Text Available The methanogenic biodegradation of crude oil is an important process occurring in petroleum reservoirs and other oil-containing environments such as contaminated aquifers. In this process, syntrophic bacteria degrade hydrocarbon substrates to products such as acetate, and/or H2 and CO2 that are then used by methanogens to produce methane in a thermodynamically dependent manner. We enriched a methanogenic crude oil-degrading consortium from production waters sampled from a low temperature heavy oil reservoir. Alkylsuccinates indicative of fumarate addition to C5 and C6 n-alkanes were identified in the culture (above levels found in controls, corresponding to the detection of an alkyl succinate synthase gene (assA in the culture. In addition, the enrichment culture was tested for its ability to produce methane from residual oil in a sandstone-packed column system simulating a mature field. Methane production rates of up 5.8 μmol CH4/g of oil/day were measured in the column system. Amounts of produced methane were in relatively good agreement with hydrocarbon loss showing depletion of more than 50% of saturate and aromatic hydrocarbons. Microbial community analysis revealed that the enrichment culture was dominated by members of the genus Smithella, Methanosaeta, and Methanoculleus. However, a shift in microbial community occurred following incubation of the enrichment in the sandstone columns. Here, Methanobacterium sp. were most abundant, as were bacterial members of the genus Pseudomonas and other known biofilm forming organisms. Our findings show that microorganisms enriched from petroleum reservoir waters can bioconvert crude oil components to methane both planktonically and in sandstone-packed columns as test systems. Further, the results suggest that different organisms may contribute to oil biodegradation within different phases (e.g., planktonic versus sessile within a subsurface crude oil reservoir.

  7. Quasi-elastic laser light scattering study of polyacrylamide hydrogel immersed in water and salt solutions

    Indian Academy of Sciences (India)

    M Sivanantham; B V R Tata

    2010-12-01

    Polyacrylamide (PAAm) hydrogels immersed in water and aqueous NaCl solutions were investigated for their structure and dynamics using static and quasi-elastic laser light scattering (QELS) techniques. Ensemble-averaged electric field correlation function (, ) obtained from the non-ergodic analysis of intensity-autocorrelation function for PAAm gel immersed in water and in 5 M NaCl showed an exponential decay to a plateau with an initial decay followed by saturation at long times. The value of the plateau was found to depend on NaCl concentration and was higher than that of water. Collective diffusion coefficient, , of the polymer network of the hydrogel immersed in water and in different concentrations of NaCl was determined by analysing (, ). The measured diffusion coefficient showed linear decrease with increase in concentration of NaCl. The characteristic network parameters were obtained by analyzing (, ) with harmonically bound Brownian particle model and from static light scattering studies.

  8. Three dimensional particle-in-cell simulations of electron beams created via reflection of intense laser light from a water target

    Energy Technology Data Exchange (ETDEWEB)

    Ngirmang, Gregory K., E-mail: ngirmang.1@osu.edu; Orban, Chris; Feister, Scott [Department of Physics, The Ohio State University, Columbus, Ohio 43210 (United States); Innovative Scientific Solutions, Inc., Plain City, Ohio 45459 (United States); Morrison, John T. [National Research Council, Washington, DC 20001 (United States); Frische, Kyle D. [Innovative Scientific Solutions, Inc., Plain City, Ohio 45459 (United States); Chowdhury, Enam A. [Department of Physics, The Ohio State University, Columbus, Ohio 43210 (United States); Intense Energy Solutions, LLC., Plain City, Ohio 43064 (United States); Roquemore, W. M. [Air Force Research Laboratory, WPAFB, Ohio 45433 (United States)

    2016-04-15

    We present 3D Particle-in-Cell (PIC) modeling of an ultra-intense laser experiment by the Extreme Light group at the Air Force Research Laboratory using the Large Scale Plasma (LSP) PIC code. This is the first time PIC simulations have been performed in 3D for this experiment which involves an ultra-intense, short-pulse (30 fs) laser interacting with a water jet target at normal incidence. The laser-energy-to-ejected-electron-energy conversion efficiency observed in 2D(3v) simulations were comparable to the conversion efficiencies seen in the 3D simulations, but the angular distribution of ejected electrons in the 2D(3v) simulations displayed interesting differences with the 3D simulations' angular distribution; the observed differences between the 2D(3v) and 3D simulations were more noticeable for the simulations with higher intensity laser pulses. An analytic plane-wave model is discussed which provides some explanation for the angular distribution and energies of ejected electrons in the 2D(3v) simulations. We also performed a 3D simulation with circularly polarized light and found a significantly higher conversion efficiency and peak electron energy, which is promising for future experiments.

  9. Materials Degradation in Light Water Reactors: Life After 60,???

    Energy Technology Data Exchange (ETDEWEB)

    Busby, Jeremy T [ORNL; Nanstad, Randy K [ORNL; Stoller, Roger E [ORNL; Feng, Zhili [ORNL; Naus, Dan J [ORNL

    2008-04-01

    Nuclear reactors present a very harsh environment for components service. Components within a reactor core must tolerate high temperature water, stress, vibration, and an intense neutron field. Degradation of materials in this environment can lead to reduced performance, and in some cases, sudden failure. A recent EPRI-led study interviewed 47 US nuclear utility executives to gauge perspectives on long-term operation of nuclear reactors. Nearly 90% indicated that extensions of reactor lifetimes to beyond 60 years were likely. When polled on the most challenging issues facing further life extension, two-thirds cited plant reliability as the key issue with materials aging and cable/piping as the top concerns for plant reliability. Materials degradation within a nuclear power plant is very complex. There are many different types of materials within the reactor itself: over 25 different metal alloys can be found with can be found within the primary and secondary systems, not to mention the concrete containment vessel, instrumentation and control, and other support facilities. When this diverse set of materials is placed in the complex and harsh environment coupled with load, degradation over an extended life is indeed quite complicated. To address this issue, the USNRC has developed a Progressive Materials Degradation Approach (NUREG/CR-6923). This approach is intended to develop a foundation for appropriate actions to keep materials degradation from adversely impacting component integrity and safety and identify materials and locations where degradation can reasonably be expected in the future. Clearly, materials degradation will impact reactor reliability, availability, and potentially, safe operation. Routine surveillance and component replacement can mitigate these factors, although failures still occur. With reactor life extensions to 60 years or beyond or power uprates, many components must tolerate the reactor environment for even longer times. This may increase

  10. Plasmonic enhancement of visible-light water splitting with Au-TiO2 composite aerogels.

    Science.gov (United States)

    DeSario, Paul A; Pietron, Jeremy J; DeVantier, Devyn E; Brintlinger, Todd H; Stroud, Rhonda M; Rolison, Debra R

    2013-09-07

    We demonstrate plasmonic enhancement of visible-light-driven splitting of water at three-dimensionally (3D) networked gold-titania (Au-TiO2) aerogels. The sol-gel-derived ultraporous composite nanoarchitecture, which contains 1 to 8.5 wt% Au nanoparticles and titania in the anatase form, retains the high surface area and mesoporosity of unmodified TiO2 aerogels and maintains stable dispersion of the ~5 nm Au guests. A broad surface plasmon resonance (SPR) feature centered at ~550 nm is present for the Au-TiO2 aerogels, but not Au-free TiO2 aerogels, and spans a wide range of the visible spectrum. Gold-derived SPR in Au-TiO2 aerogels cast as films on transparent electrodes drives photoelectrochemical oxidation of aqueous hydroxide and extends the photocatalytic activity of TiO2 from the ultraviolet region to visible wavelengths exceeding 700 nm. Films of Au-TiO2 aerogels in which Au nanoparticles are deposited on pre-formed TiO2 aerogels by a deposition-precipitation method (DP Au/TiO2) also photoelectrochemically oxidize aqueous hydroxide, but less efficiently than 3D Au-TiO2, despite having an essentially identical Au nanoparticle weight fraction and size distribution. For example, 3D Au-TiO2 containing 1 wt% Au is as active as DP Au/TiO2 with 4 wt% Au. The higher photocatalytic activity of 3D Au-TiO2 derives only in part from its ability to retain the surface area and porosity of unmodified TiO2 aerogel. The magnitude of improvement indicates that in the 3D arrangement either a more accessible photoelectrochemical reaction interphase (three-phase boundary) exists or more efficient conversion of excited surface plasmons into charge carriers occurs, thereby amplifying reactivity over DP Au/TiO2. The difference in photocatalytic efficiency between the two forms of Au-TiO2 demonstrates the importance of defining the structure of Au[parallel]TiO2 interfaces within catalytic Au-TiO2 nanoarchitectures.

  11. Electrophoretic painting on AZ31 Mg alloy pretreated in cerium conversion coating solutions prepared in ethanol-water mixtures

    Science.gov (United States)

    Van Phuong, Nguyen; Fazal, Basit Raza; Moon, Sungmo

    2017-01-01

    Electrophoretic painting (E-paint) was prepared on AZ31 Mg alloy samples pretreated in cerium conversion coating (CeCC) solutions with various ratios of ethanol and water mixture and its characteristics, adhesion and corrosion resistance were investigated. It was found that CeCC formed on AZ31 Mg alloy in a CeCC solution without ethanol was partly cracked structure and mainly consisted of Mg(OH)2/MgO, which exhibited weak adhesion with E-painting layer after water immersion test, and low corrosion resistance, as indicated by rapid formation of blisters and paint delamination during salt spray test. The addition of ethanol promoted the growth of a fine nano-crystalline CeO2 layer over the entire substrate surface. The E-paint on AZ31 pretreated in the CeCC solutions with addition of ethanol showed also improved corrosion resistance, as represented by the delayed time for paint delamination and blister formation. The E-paint layers on the CeCC layers formed in solutions containing 50-80 vol% ethanol showed stronger adhesion and better corrosion resistance than those formed on the samples treated in a non-ethanol containing CeCC solution.

  12. Evaluation of Additives to Eliminate Free Water from Aviation Fuel Light Obscuration Particle Counts

    Science.gov (United States)

    2015-11-01

    meeting IP 565. To benchmark this data, ASTM D2276 gravimetric and ASTM D3240 free water data was also collected. The particle counts taken with... Quality Assurance/Surveillance for Fuels, Lubricants and Related Products. MIL-STD-3004D. October 9, 2014. 2. DoD Management Policy for Energy...5000 DISTRIBUTION A. Approved for public release: distribution unlimited. Evaluation of Additives to Eliminate Free Water from Aviation Fuel Light

  13. A polarized liquid-liquid interface meets visible light-driven catalytic water oxidation.

    Science.gov (United States)

    Rastgar, Shokoufeh; Pilarski, Martin; Wittstock, Gunther

    2016-09-15

    Hyperbranched nanostructured bismuth vanadate at a chemically polarized water/organic interface is applied for efficient visible light-driven catalytic oxidation of water in the presence of [Co(bpy)3](PF6)3 as an organic soluble electron acceptor. The photocurrent response originating from the transfer of photo-excited electrons in BiVO4 to [Co(bpy)3](3+) is measured by scanning electrochemical microscopy.

  14. Light illuminated α-Fe2O3/Pt nanoparticles as water activation agent for photoelectrochemical water splitting.

    Science.gov (United States)

    Li, Xiaodong; Wang, Zhi; Zhang, Zemin; Chen, Lulu; Cheng, Jianli; Ni, Wei; Wang, Bin; Xie, Erqing

    2015-03-16

    The photoelectrochemical (PEC) water splitting is hampered by strong bonds of H2O molecules and low ionic conductivity of pure water. The photocatalysts dispersed in pure water can serve as a water activation agent, which provides an alternative pathway to overcome such limitations. Here we report that the light illuminated α-Fe2O3/Pt nanoparticles may produce a reservoir of reactive intermediates including H2O2, ·OH, OH(-) and H(+) capable of promoting the pure water reduction/oxidation half-reactions at cathode and highly photocatalytic-active TiO2/In2S3/AgInS2 photoanode, respectively. Remarkable photocurrent enhancement has been obtained with α-Fe2O3/Pt as water activation agent. The use of α-Fe2O3/Pt to promote the reactivity of pure water represents a new paradigm for reproducible hydrogen fuel provision by PEC water splitting, allowing efficient splitting of pure water without adding of corrosive chemicals or sacrificial agent.

  15. Light

    CERN Document Server

    Robertson, William C

    2003-01-01

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

  16. Catalytic conversion of light alkanes-proof-of-concept stage - Phase IV. Topical report, February 1, 1994--January 31, 1995

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-12-31

    This report details the research performed on Phase IV of the extended Cooperative Agreement. This Phase, entitled C{sub 1}-C{sub 4} Research, provides the research support which accompanies the C{sub 4} Proof-of-Concept Phase (Phase V) as the two major activities of the Cooperative Agreement during calendar 1993. It is the objective of this phase to understand the nature of the catalysts and catalytic activity of perhaloporphyrin complexes uncovered during Phases I-III in order that superior catalytic materials can be made and tested which meet commercial criteria for the oxidation of the C{sub 1}-C{sub 4} light alkane gases found in natural gas and other available hydrocarbon streams. During Phase IV, we have examined the physical and electronic structures of the very active perhaloporphyrin catalysts which we have developed, and have gained an understanding of the properties which make them active. This has led us to design and synthesize materials which are cheaper, more active, more robust and, in general superior for carrying out practical catalysis. Our early generation perhaloporphyrin catalysts, while exhibiting unprecedented catalytic activity, were far too expensive for use in converting natural gas or its C{sub 1}-C{sub 4} components.

  17. Electrodeposition of Nanometer-Sized Ferric Oxide Materials in Colloidal Templates for Conversion of Light to Chemical Energy

    Directory of Open Access Journals (Sweden)

    James M. Gardner

    2011-01-01

    Full Text Available Colloidal crystal templates were prepared by gravitational sedimentation of 0.5 micron polystyrene particles onto fluorine-doped tin oxide (FTO electrodes. Scanning electron microscopy (SEM shows that the particles were close packed and examination of successive layers indicated a predominantly face-centered-cubic (fcc crystal structure where the direction normal to the substrate surface corresponds to the (111 direction. Oxidation of aqueous ferrous solutions resulted in the electrodeposition of ferric oxide into the templates. Removal of the colloidal templates yielded ordered macroporous electrodes (OMEs that were the inverse structure of the colloidal templates. Current integration during electrodeposition and cross-sectional SEM images revealed that the OMEs were about 2 μm thick. Comparative X-ray diffraction and infrared studies of the OMEs did not match a known phase of ferric oxide but suggested a mixture of goethite and hematite. The spectroscopic properties of the OMEs were insensitive to heat treatments at 300∘C. The OMEs were utilized for photoassisted electrochemical oxidation. A sustained photocurrent was observed from visible light in aqueous photoelectrochemical cells. Analysis of photocurrent action spectra revealed an indirect band gap of 1.85 eV. Addition of formate to the aqueous electrolytes resulted in an approximate doubling of the photocurrent.

  18. Ocean thermal energy conversion cold water pipe preliminary design project. Final report

    Energy Technology Data Exchange (ETDEWEB)

    1979-11-20

    As part of a DOE goal to develop one or more OTEC Modular Experiment Plants, TRW performed designs, analyses, and evaluations of cold water pipe (CWP) concepts for NOAA. After reviewing the results of the CWP concept selection phase NOAA/DOE selected three concepts for a baseline design: (1) a FRP CWP of sandwich wall construction suspended from the Applied Physics Laboratory/John Hopkins University (APL/JHU) barge at a site 200 miles east of the coast of Brazil using a horizontal deployment scheme (this is TRW's preferred approach); (2) an elastomer CWP suspended from the APL/JHU barge off the southeast coast of Puerto Rico using either a horizontal or vertical deployment scheme; and (3) a polyethylene CWP (single or multiple pipe) suspended from the Gibbs and Cox spar at the Puerto Rico site using a horizontal deployment scheme. TRW has developed a baseline design for each of these configurations. Detailed designs and analyses for the FRP, polyethylene, and elastomer concepts, respectively, are described. A discussion of fabrication plans and processes, schedules for mobilization of facilities and equipment, installation plans, and cost breakdown are given for each concept. (WHK)

  19. Advanced gasifier and water gas shift technologies for low cost coal conversion to high hydrogen syngas

    Energy Technology Data Exchange (ETDEWEB)

    Kramer, Andrew Kramer [Gas Technology Inst., Des Plaines, IL (United States)

    2016-09-30

    The Gas Technology Institute (GTI) and team members RTI International (RTI), Coanda Research and Development, and Nexant, are developing and maturing a portfolio of technologies to meet the United States Department of Energy (DOE) goals for lowering the cost of producing high hydrogen syngas from coal for use in carbon capture power and coal-to-liquids/chemicals. This project matured an advanced pilot-scale gasifier, with scalable and commercially traceable components, to readiness for use in a first-of-a-kind commercially-relevant demonstration plant on the scale of 500-1,000 tons per day (TPD). This was accomplished through cold flow simulation of the gasifier quench zone transition region at Coanda and through an extensive hotfire gasifier test program on highly reactive coal and high ash/high ash fusion temperature coals at GTI. RTI matured an advanced water gas shift process and catalyst to readiness for testing at pilot plant scale through catalyst development and testing, and development of a preliminary design basis for a pilot scale reactor demonstrating the catalyst. A techno-economic analysis was performed by Nexant to assess the potential benefits of the gasifier and catalyst technologies in the context of power production and methanol production. This analysis showed an 18%reduction in cost of power and a 19%reduction in cost of methanol relative to DOE reference baseline cases.

  20. Ocean thermal energy conversion cold water pipe preliminary design project. Task 2. Analysis for concept selection

    Energy Technology Data Exchange (ETDEWEB)

    None

    1979-04-01

    The successful performance of the CWP is of crucial importance to the overall OTEC system; the pipe itself is considered the most critical part of the entire operation. Because of the importance the CWP, a project for the analysis and design of CWP's was begun in the fall of 1978. The goals of this project were to study a variety of concepts for delivering cold water to an OTEC plant, to analyze and rank these concepts based on their relative cost and risk, and to develop preliminary design for those concepts which seemed most promising. Two representative platforms and sites were chosen: a spar buoy of a Gibbs and Cox design to be moored at a site off Punta Tuna, Puerto Rico, and a barge designed by APL/Johns Hopkins University, grazing about a site approximately 200 miles east of the coast of Brazil. The approach was to concentrate on the most promising concepts and on those which were either of general interest or espoused by others (e.g., steel and concrete concepts). Much of the overall attention, therefore, focused on analyzing rigid and compliant wall design, while stockade (except for the special case of the FRP stockade) and bottom-mounted concepts received less attention. A total of 67 CWP concepts were initially generated and subjected to a screening process. Of these, 16 were carried through design analysis, costing, and ranking. Study results are presented in detail. (WHK)

  1. Growth Promotion of a Sea Water Algae with Sterile, Ulva pertusa Kjellman, Due to Supplemental Lighting

    Science.gov (United States)

    Kosaka, Shinichi; Masuda, Atsunori; Ozawa, Tomoko; Ishiwata, Masaki; Yokoji, Shigemi; Saito, Naoki; Murakami, Katsusuke

    Ulva pertusa is widely used as human food and also to feed cultured fish. U. pertusa is expected to be used as a bio-filter for purification of breeding - circulation water in the terrestrial aquaculture of fish. Insufficient sunshine and lower temperature causes bad commercial production. In order to realize stable cultivation of U. pertusa throughout the year, experiments on the growth of a sea water algae with sterile, U. pertusa Kjellman, due to supplemental lighting were performed. An illuminance of 1×104 lx in the treatment areas and 2×104 lx in the control, when the illuminance was 8×104 lx in the greenhouse. Artificial lighting was added during the daytime in treatments 1˜3. The mounting height of each luminaire was adjusted to have a PPFD of 140 μmol m-2s-1. Each lamp had the R/FR PF ratio of 3.8, 1.2, 0.8. Considering of relationship between the growth and cumulative PPFD including daylight and supplemental lighting, the growth of the experimental area were superior to the control area. U. pertusa can be grown with warm sea water using supplemental lighting. But under the growth environment with daylight and supplemental lighting together, it is difficult to recognize whether the R/FR PF ratio influences photomorphogenesis.

  2. Conversion of urodynamic pressures measured simultaneously by air-charged and water-filled catheter systems.

    Science.gov (United States)

    Awada, Hassan K; Fletter, Paul C; Zaszczurynski, Paul J; Cooper, Mitchell A; Damaser, Margot S

    2015-08-01

    The objective of this study was to compare the simultaneous responses of water-filled (WFC) and air-charged (ACC) catheters during simulated urodynamic pressures and develop an algorithm to convert peak pressures measured using an ACC to those measured by a WFC. Examples of cough leak point pressure and valsalva leak point pressure data (n = 4) were obtained from the literature, digitized, and modified in amplitude and duration to create a set of simulated data that ranged in amplitude from 15 to 220 cm H2 O (n = 25) and duration from 0.1 to 3.0 sec (n = 25) for each original signal. Simulated pressure signals were recorded simultaneously by WFCs, ACCs, and a reference transducer in a specially designed pressure chamber. Peak pressure and time to peak pressure were calculated for each simulated pressure signal and were used to develop an algorithm to convert peak pressures recorded with ACCs to corresponding peak pressures recorded with WFCs. The algorithm was validated with additional simulated urodynamic pressure signals and additional catheters that had not been utilized to develop the algorithm. ACCs significantly underestimated peak pressures of more rapidly changing pressures, as in coughs, compared to those measured by WFCs. The algorithm corrected 90% of peak pressures measured by ACCs to within 5% of those measured by WFCs when simultaneously exposed to the same pressure signals. The developed algorithm can be used to convert rapidly changing urodynamic pressures, such as cough leak point pressure, obtained using ACC systems to corresponding values expected from WFC systems. © 2014 Wiley Periodicals, Inc.

  3. Conversion of Iodide to Hypoiodous Acid and Molecular Iodine at the Air-Water Interface

    Science.gov (United States)

    Pillar, E. A.; Guzman, M. I.

    2013-12-01

    Sea spray aerosols continuously transfer a significant amount of halides to the marine boundary layer, where they play a major role in the depletion of tropospheric ozone. The reactivity of iodide is of special interest in sea spray aerosols, where this species is enriched relative to chloride and bromide in surface seawater. This work presents laboratory experiments that provide mechanistic information to understand the reactivity of halides in atmospheric aerosols. Pneumatically assisted electrospray is used to aerosolize solutions of sodium iodide (0.01-100 μM), which are rapidly (~3 μs) oxidized by ozone at 25 °C. Reaction products include HIO, IO2-, IO3-, I2, HI2O-, and I3-, all identified by mass spectrometry. The distribution of products varies along two different reaction pathways, one favoring the production of I2 and HIO for typical tropospheric ozone levels (~50 ppbv), and another one directed to the production of IO3- at higher oxidizer concentrations. The formation of products increases exponentially with rising concentrations of initial sodium iodide, [NaI]0. The process is determined to be pH independent for the pH range 6-8 representative of surface waters. The substitution of aqueous solutions by organic solvents, such as methanol or acetonitrile, causes a decrease in the surface tension and lifetime of the droplets, leading to larger I2 production. The presence of surface active organic compounds, which alter the structure of the interfacial region, promote the pathway of I2 formation over IO3-. In conclusion, this presentation will show how the oxidation of iodide in aqueous microdroplets can release reactive gas-phase species, such as I2 and HIO, capable to affect tropospheric ozone globally. Normalized intensity of products observed during the ozonolysis of iodide solutions at 130 ppbv ozone. Cone voltage = 70 V, needle voltage = 2.5 kV.

  4. Direct catalytic conversion of methane and light hydrocarbon gases. Quarterly report No. 6, January 16, 1988--April 15, 1988

    Energy Technology Data Exchange (ETDEWEB)

    Wilson, R.B. Jr.; Chan, Yee Wai; Posin, B.M.

    1988-05-20

    The goal of this research is to develop catalysts that directly convert methane and light hydrocarbons to intermediates that later can be converted to either liquid fuels or value-added chemicals, as economics dictate. During this reporting period, we synthesized several phthalocyanine catalysts supported on magnesia (MgO) in Task 3. In Task 4 we have tested these catalysts for oxidation of methane and did a number of blank experiments to determine the cause of the low methanol yield we have observed. Magnesia supported catalysts were prepared by first synthesizing the various metal tetrasulfophthalocyanines (TSPCs), converting them to the acid form, and then supporting these complexes on a basic support (MgO) by a neutralization reaction. The metals used were Ru, Pd, Cu, Fe, Co, Mn, and Mo. CoTSPC was also synthesized in zeolite Y using our standard template techniques described in Quarterly Report No. 1. These complexes were examined for catalytic activity in the oxidation of methane. The PdTSPC/MgO had greater activity, and oxidized some of the methane (selectivity of 2.8% from the methane oxidized at 375{degrees}C) to ethane. This is a much lower temperature for this reaction than previously reported in the literature. We also examined the reactivity of various components of the system in the oxidation of the product methanol. The reactor showed some activity for the oxidation of methanol to carbon dioxide. When zeolite or magnesia were added, this activity increased. The magnesia oxidized most of the methanol to carbon dioxide, while the zeolite reduced some of the methanol to hydrocarbons. With oxygen in the feed gas stream (i.e., the conditions of our methane oxidation), a very large fraction of the methanol was oxidized to carbon dioxide when passed over magnesia. From this, we can conclude that any methanol formed in the oxidation of methane would probably be destroyed very quickly on the catalyst bed.

  5. The influence of savanna trees on nutrient, water and light availability and the understorey vegetation

    NARCIS (Netherlands)

    Ludwig, F.; Kroon, J.C.J.M. de; Berendse, F.; Prins, H.H.T.

    2004-01-01

    In an East African savanna herbaceous layer productivity and species composition were studied around Acacia tortilis trees of three different age classes, as well as around dead trees and in open grassland patches. The effects of trees on nutrient, light and water availability were measured to

  6. Light Water Reactor Sustainability Constellation Pilot Project FY11 Summary Report

    Energy Technology Data Exchange (ETDEWEB)

    R. Johansen

    2011-09-01

    Summary report for Fiscal Year 2011 activities associated with the Constellation Pilot Project. The project is a joint effor between Constellation Nuclear Energy Group (CENG), EPRI, and the DOE Light Water Reactor Sustainability Program. The project utilizes two CENG reactor stations: R.E. Ginna and Nine Point Unit 1. Included in the report are activities associate with reactor internals and concrete containments.

  7. DIMENSIONAL STABILITY AND WATER REPELLENT EFFICIENCY MEASUREMENT OF CHEMICALLY MODIFIED TROPICAL LIGHT HARDWOOD

    OpenAIRE

    Md. Saiful Islam; Sinin Hamdan; Mohamad Rusop; Md. Rezaur Rahman; Abu Saleh Ahmed; M. A. M. Mohd Idrus

    2012-01-01

    Chemical modification is an often-followed route to improve physical and mechanical properties of solid wood materials. In this study five kinds of tropical light hardwoods species, namely jelutong (Dyera costulata), terbulan (Endospermum diadenum), batai (Paraserianthes moluccana), rubberwood (Hevea brasiliensis), and pulai (Alstonia pneumatophora), were chemically modified with benzene diazonium salt to improve their dimensional stability and water repellent efficiency. The dimensional stab...

  8. Detection of the Cherenkov light diffused by Sea Water with the ULTRA Experiment

    CERN Document Server

    Agnetta, G; Biondo, B; Brogueira, P; Cappa, A; Catalano, O; Chauvin, J; Staiti, G D'Ali'; Dattoli, M; Espirito-Santo, M C; Fava, L; Galeotti, P; Giarrusso, S; Gugliotta, G; La Rosa, G; Lebrun, D; Maccarone, M C; Mangano, A; Melo, L; Moreggia, S; Pimenta, M; Russo, F; Saavedra, O; Segreto, A; Silva, J C; Stassi, P; Tome', B; Vallania, P; Vigorito, C

    2007-01-01

    The study of Ultra High Energy Cosmic Rays represents one of the most challenging topic in the Cosmic Rays and in the Astroparticle Physics fields. The interaction of primary particles with atmospheric nuclei produces a huge Extensive Air Shower together with isotropic emission of UV fluorescence light and highly directional Cherenkov photons, that are reflected/diffused isotropically by the impact on the Earth's surface or on high optical depth clouds. For space-based observations, detecting the reflected Cherenkov signal in a delayed coincidence with the fluorescence light improves the accuracy of the shower reconstruction in space and in particular the measurement of the shower maximum, giving a strong signature for discriminating hadrons and neutrinos, and helping to estimate the primary chemical composition. Since the Earth's surface is mostly covered by water, the ULTRA (UV Light Transmission and Reflection in the Atmosphere)experiment has been designed to provide the diffusing properties of sea water, ...

  9. Conceptual design and economic analysis of a light water reactor fuel enricher/regenerator. FY 1978 year-end report

    Energy Technology Data Exchange (ETDEWEB)

    Grand, P; Kouts, H J; Powell, J R; Steinberg, M; Takahashi, H

    1979-05-01

    A study has been performed to evaluate the use of high-energy particle accelerators as nuclear fuel enrichers and nuclear fuel regenerators. This builds on ideas that have been current for many years. The new study has, however, explored some novel approaches that have not been examined before. A specific conceptual system chosen for more detailed study would stretch the energy available from natural uranium by a factor of about 3, reduce the separative work requirements by a factor of about 4, and reduce the volume of spent fuel to be stored by a factor of 2, compared to the current once-through light water reactor (LWR) fuel cycle. The concept avoids the need for chemical reprocessing of spent fuel, and would permit continued use of LWR's beyond the time when limitations on fuel resources might otherwise lead to their being phased out. This concept, which is called the Linear Accelerator Fuel Enricher/Regenerator, is therefore viewed as offering a practical means of stretching the use of the nuclear fuel resource in the framework of the existing light water reactor fuel cycle. This report describes and analyzes the concept referred to. An explanation of the principles underlying the concept is given. Particular attention is devoted to engineering feasibility, proliferation resistance, and economics. It is seen that the concept draws on only proven technology as regards bothaccelerator design and the fuel irradiation process, and is adapted to existing LWR designs with no change except in fuel-handling practices. A preliminary evaluation of radiation damage, coolant options, and power conversion systems is provided. Neutronic, thermal-hydraulic, and burnup calculations are presented. An analysis is made of fuel economy. Approximate costs of electric power produced using this concept are evaluated and discussed. Estimated development costs of commercialization are provided.

  10. Risks of nuclear energy technology safety concepts of light water reactors

    CERN Document Server

    Kessler, Günter; Schlüter, Franz-Hermann

    2014-01-01

    The book analyses the risks of nuclear power stations. The security concept of reactors is explained. Measures against the spread of radioactivity after a severe accident, accidents of core melting and a possible crash of an air plane on?reactor containment are discussed. The book covers three scientific subjects of the safety concepts of Light Water Reactors: ? A first part describes the basic safety design concepts of operating German Pressurized Water Reactors and Boiling Water Reactors including accident management measures introduced after the reactor accidents of Three Mile Island and Ch

  11. Microfluidic reactors for visible-light photocatalytic water purification assisted with thermolysis.

    Science.gov (United States)

    Wang, Ning; Tan, Furui; Wan, Li; Wu, Mengchun; Zhang, Xuming

    2014-09-01

    Photocatalytic water purification using visible light is under intense research in the hope to use sunlight efficiently, but the conventional bulk reactors are slow and complicated. This paper presents an integrated microfluidic planar reactor for visible-light photocatalysis with the merits of fine flow control, short reaction time, small sample volume, and long photocatalyst durability. One additional feature is that it enables one to use both the light and the heat energy of the light source simultaneously. The reactor consists of a BiVO4-coated glass as the substrate, a blank glass slide as the cover, and a UV-curable adhesive layer as the spacer and sealant. A blue light emitting diode panel (footprint 10 mm × 10 mm) is mounted on the microreactor to provide uniform irradiation over the whole reactor chamber, ensuring optimal utilization of the photons and easy adjustments of the light intensity and the reaction temperature. This microreactor may provide a versatile platform for studying the photocatalysis under combined conditions such as different temperatures, different light intensities, and different flow rates. Moreover, the microreactor demonstrates significant photodegradation with a reaction time of about 10 s, much shorter than typically a few hours using the bulk reactors, showing its potential as a rapid kit for characterization of photocatalyst performance.

  12. Oxidative processes in soybean and pea seeds: effect of light, temperature, and water content

    Science.gov (United States)

    Vertucci, C. W.; Leopold, A. C.

    1987-01-01

    Oxidative processes are probable determinants of longevity of seeds in storage. Measurements of actual oxygen uptake rates were made for soybean and pea seeds as a comparison of short and long lived seeds when light, temperature, and moisture contents were varied. In both peas and soybeans, the oxygen uptake was depressed at low temperatures (water contents (water contents and at temperatures greater than 22 degrees C are much less. Light enhances the level of oxygen uptake in pea, but reduces the level of oxygen uptake in soybean. The complexities of the interactions of oxygen uptake with environmental conditions in soybean compared to pea suggest that oxidative processes occur in soybean at low water contents, but are essentially absent in pea. It is suggested that the additional oxidative processes in soybean with moisture contents between 0.10 and 0.24 gram per gram may contribute to the poorer longevity of soybean seed compared to pea seed.

  13. Low pressure water vapour discharge as a light source: II. Electrical characteristics

    Energy Technology Data Exchange (ETDEWEB)

    Artamonova, E; Artamonova, T; Beliaeva, A; Khodorkovskii, M; Melnikov, A; Milenin, V; Murashov, S; Rakcheeva, L; Timofeev, N [Saint Petersburg State University, Ulyanovskaya 3, Petrodvoretz, Saint Petersburg 198504 (Russian Federation); Michael, D [General Electric Global Research Center, One Research Circle (Bldg K1 Rm 4B31A), Niskayuna, NY 12309 (United States); Zissis, G, E-mail: timofeev@pobox.spbu.r, E-mail: michael@crd.ge.co, E-mail: georges.zissis@laplace.univ-tlse.f [Universite Toulouse 3-Paul Sabatier, LAPLACE Building 3R2, 118 rte de Narbonne, F-31062 Toulouse Cedex 9 (France)

    2009-09-07

    The electric field strength, electrode fall voltage, light emission characteristics and efficiency of a (Ar + H{sub 2}O) dc discharge as functions of water vapour content, argon pressure and electric current are presented. The data show that the main processes of 306.4 nm OH band generation are (1) a collision between an excited argon atom and a water molecule with simultaneous excitation of OH into the A {sup 2}{Sigma}{sup +} state and (2) electron excitation of a ground state hydroxyl molecule produced by a quenching process from a water molecule. Electric field strength measurements make it possible to conclude that the light production efficiency of the plasma under study can reach 35 lm W{sup -1}. It is possible, with these data, to propose a model of the plasma in question having reasonable accordance with the experiment and show the way to further increase the efficiency.

  14. Symmetry breaking and light-induced spin-state trapping in a mononuclear FeII complex with the two-step thermal conversion

    Science.gov (United States)

    Buron-Le Cointe, M.; Ould Moussa, N.; Trzop, E.; Moréac, A.; Molnar, G.; Toupet, L.; Bousseksou, A.; Létard, J. F.; Matouzenko, G. S.

    2010-12-01

    Crystallographic, magnetic, and Raman investigations of the mononuclear [FeII(Hpy-DAPP)](BF4)2 complex are presented. Its particular feature is a two-step thermal spin conversion in spite of a unique symmetry-independent iron site per unit cell. The plateau around 140 K is associated with a symmetry breaking visible by the appearance of weak (0k0) k odd Bragg peaks. Symmetries of the high-temperature high-spin state and of the low-temperature low-spin state are both monoclinic P21/c , so that the symmetry breaking on the plateau is associated with a reentrant phase transition. It is discussed in relation with Ising-type microscopic models. At the plateau level, the two symmetry-independent molecules differ both by their spin state and the conformation (chair versus twist-boat) of one metallocycle. At low-temperature photoinduced phenomena have been investigated: a partial phototransformation [light-induced excited spin-state trapping (LIESST) effect] is observed under visible red irradiation. Raman spectroscopy shows that the molecular photoinduced state is the high-spin one. Nevertheless, as no macroscopic symmetry breaking is observed, the unique average cationic [FeII(Hpy-DAPP)] state of the unit cell is intermediate between pure low-spin and high-spin states and presents a conformational disorder for one metallocycle. Reverse-LIESST has also been evidenced using near infrared excitation. Thus, the mononuclear [Fe(Hpy-DAPP)](BF4)2 compound offers the opportunity to discuss the interplay between spin conversion, molecular conformational change, and ordering processes.

  15. Disinfection of Spacecraft Potable Water Systems by Photocatalytic Oxidation Using UV-A Light Emitting Diodes

    Science.gov (United States)

    Birmele, Michele N.; O'Neal, Jeremy A.; Roberts, Michael S.

    2011-01-01

    Ultraviolet (UV) light has long been used in terrestrial water treatment systems for photodisinfection and the removal of organic compounds by several processes including photoadsorption, photolysis, and photocatalytic oxidation/reduction. Despite its effectiveness for water treatment, UV has not been explored for spacecraft applications because of concerns about the safety and reliability of mercury-containing UV lamps. However, recent advances in ultraviolet light emitting diodes (UV LEDs) have enabled the utilization of nanomaterials that possess the appropriate optical properties for the manufacture of LEDs capable of producing monochromatic light at germicidal wavelengths. This report describes the testing of a commercial-off-the-shelf, high power Nichia UV-A LED (250mW A365nnJ for the excitation of titanium dioxide as a point-of-use (POD) disinfection device in a potable water system. The combination of an immobilized, high surface area photocatalyst with a UV-A LED is promising for potable water system disinfection since toxic chemicals and resupply requirements are reduced. No additional consumables like chemical biocides, absorption columns, or filters are required to disinfect and/or remove potentially toxic disinfectants from the potable water prior to use. Experiments were conducted in a static test stand consisting of a polypropylene microtiter plate containing 3mm glass balls coated with titanium dioxide. Wells filled with water were exposed to ultraviolet light from an actively-cooled UV-A LED positioned above each well and inoculated with six individual challenge microorganisms recovered from the International Space Station (ISS): Burkholderia cepacia, Cupriavidus metallidurans, Methylobacterium fujisawaense, Pseudomonas aeruginosa, Sphingomonas paucimobilis and Wautersia basilensis. Exposure to the Nichia UV-A LED with photocatalytic oxidation resulted in a complete (>7-log) reduction of each challenge bacteria population in <180 minutes of contact

  16. Diagnostic and Prognostic Value of the Cerebrospinal Fluid Concentration of Immunoglobulin Free Light Chains in Clinically Isolated Syndrome with Conversion to Multiple Sclerosis.

    Directory of Open Access Journals (Sweden)

    Gleb Makshakov

    Full Text Available In this study, we evaluated the diagnostic and prognostic significance of cerebrospinal fluid free light chains (CSF FLC at the time of clinically isolated syndrome (CIS.We compared FLC-parameters at the moment of CIS in patients with conversion to multiple sclerosis (MS after 2 years (CIS-MS, patients who remained stable both clinically and radiologically after 2 years (CIS-nonMS, patients with non-inflammatory neurologic diseases (NIND as a comparison group and patients with other inflammatory neurologic diseases (IND with intrathecal oligoclonal bands (OCB synthesis. ROC-analysis was conducted to define FLC-assay characteristics and cut-off values. We also compared FLC-concentrations in CIS patients to determine their OCB-status. A correlation analysis was performed between FLC-concentrations and the expanded disability scale score (EDSS, annualized relapse rate (ARR and MRI-activity (i.e., number of new and gadolinium-enhancing (Gd+ lesions in patients.The levels of kappa-FLC (k-FLCCSF and lambda-FLC (λ-FLCCSF as well as kappa- and lambda-quotients (Q-k and Q-λ were elevated in CIS-MS compared to the CIS-nonMS and NIND groups. These levels did not differ significantly when compared with the IND group. We identified several patients with high k-FLCCSF and λ-FLCCSF in OCB-negative CIS and IND groups. The level of k-FLCCSF production was significantly higher in OCB-positive patients in the CIS-MS group compared to the CIS-nonMS group. The concentrations of k-FLCCSF and Q-k in the CIS-MS group showed significant correlation with the level of EDSS after 2 years (k-FLC: r = 0.4477,p = 0.0016; Q-k: r = 0.4621, p = 0.0016. λ-FLCCSF and Q-λ inversely correlated with the number of Gd+ lesions (CSF λ-FLC: r = -0.3698, p = 0.0223; Q-λ: r = -0.4527, p = 0.0056.The concentration of CSF FLC predicts conversion to MS within 2 years following CIS. OCB-positive patients with an early conversion have a higher concentration of CSF-FLC. We have also shown

  17. Emergency reactor core cooling water injection device for light water reactor

    Energy Technology Data Exchange (ETDEWEB)

    Oda, Junro.

    1994-05-13

    A reactor pressure vessel is immersed in pool water of a reactor container. A control valve is interposed to a water supplying pipelines connecting pool water and a pressure vessel. A valve actuation means for opening/closing the control valve comprises a lifting tank. The inner side of the lifting tank and the inner side of the pressure vessel are connected by a communication pipeline (a syphon pipe) at upper and lower two portions. The lifting tank and the control valve are connected by a link mechanism. When a water level in the pressure vessel is lowered, the water level in the lifting tank is lowered to the same level as that in the pressure vessel. This reduces the weight of the lifting tank, the lifting tank is raised, to open the control valve by way of a link mechanism. As a result, liquid phase in the pressure vessel is in communication with the pool water, and the pool water flows down into the pressure vessel to maintain the reactor core in a flooded state. (I.N.).

  18. Light

    CERN Document Server

    Ditchburn, R W

    2011-01-01

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

  19. Double-shelled plasmonic Ag-TiO{sub 2} hollow spheres toward visible light-active photocatalytic conversion of CO{sub 2} into solar fuel

    Energy Technology Data Exchange (ETDEWEB)

    Feng, Shichao; Wang, Meng; Li, Ping; Tu, Wenguang [National Laboratory of Solid State Microstructures, Collaborative Innovation Center of Advanced Microstructures, School of Physics, Nanjing University, Nanjing 210093 (China); Eco-Materials and Renewable Energy Research Center (ERERC), Nanjing University, Nanjing 210093 (China); Zhou, Yong [National Laboratory of Solid State Microstructures, Collaborative Innovation Center of Advanced Microstructures, School of Physics, Nanjing University, Nanjing 210093 (China); Eco-Materials and Renewable Energy Research Center (ERERC), Nanjing University, Nanjing 210093 (China); Key Laboratory of Modern Acoustics (MOE), Institute of Acoustics, Department of Physics, Nanjing University, Nanjing 210093 (China); Jiangsu Key Laboratory for Nano Technology, Nanjing University, Nanjing 210093 (China); Zou, Zhigang [National Laboratory of Solid State Microstructures, Collaborative Innovation Center of Advanced Microstructures, School of Physics, Nanjing University, Nanjing 210093 (China); Eco-Materials and Renewable Energy Research Center (ERERC), Nanjing University, Nanjing 210093 (China); Jiangsu Key Laboratory for Nano Technology, Nanjing University, Nanjing 210093 (China)

    2015-10-01

    Double-shelled hollow hybrid spheres consisting of plasmonic Ag and TiO{sub 2} nanoparticles were successfully synthesized through a simple reaction process. The analysis reveals that Ag nanoparticles were dispersed uniformly in the TiO{sub 2} nanoparticle shell. The plasmonic Ag-TiO{sub 2} hollow sphere proves to greatly enhance the photocatalytic activity toward reduction of CO{sub 2} into renewable hydrocarbon fuel (CH{sub 4}) in the presence of water vapor under visible-light irradiation. The possible formation mechanism of the hollow sphere and related plasmon-enhanced photocatalytic performance were also briefly discussed.

  20. Experimental and Modeling Studies on the Conversion of Inulin to 5-Hydroxymethylfurfural Using Metal Salts in Water

    Directory of Open Access Journals (Sweden)

    Boy Arief Fachri

    2015-12-01

    Full Text Available Inulin, a plant polysaccharide consisting of mainly d-fructose units, is considered an interesting feed for 5-hydroxymethylfurfural (HMF, a top 12 bio-based chemical. We here report an exploratory experimental study on the use of a wide range of homogeneous metal salts as catalysts for the conversion of inulin to HMF in water. Best results were obtained using CuCl2. Activity-pH relations indicate that the catalyst activity of CuCl2 is likely related to Lewis acidity and not to Brönsted acidity. The effects of process conditions on HMF yield for CuCl2 were systematically investigated and quantified using a central composite design (160–180 °C, an inulin loading between 0.05 and 0.15 g/mL, CuCl2 concentration in range of 0.005–0.015 M, and a reaction time between 10 and 120 min. The highest experimental HMF yield in the process window was 30.3 wt. % (39 mol %, 180 °C, 0.05 g/mL inulin, 0.005 M CuCl2 and a reaction time of 10 min. The HMF yields were modelled using non-linear, multi variable regression and good agreement between experimental data and model were obtained.

  1. Broadband light-absorption InGaN photoanode assisted by imprint patterning and ZnO nanowire growth for energy conversion

    Science.gov (United States)

    Kang, Junjie; Quang Dang, Vinh; Li, Hongjian; Moon, Sungjin; Li, Panpan; Kim, Yangdoo; Kim, Chaehyun; Choi, Jinyoung; Choi, Hakjong; Liu, Zhiqiang; Lee, Heon

    2017-01-01

    In this research, an InGaN-based photoanode with a broadband light-absorption range from ultraviolet to green, patterned by imprint lithography and branched by ZnO nanowires, has been applied to water splitting. Over the solar spectrum range, the absorbance increases due to the scattering effect of the micro-structure compared to that of flat surface InGaN, which reaches a maximum of over 90% at 380 nm as ZnO nanowires are further employed in this novel photoanode. Consequently, the induced photocurrent density of the InGaN photoanode with a domelike structure and ZnO nanowires on the surface shows a remarkable enhancement of seven times that of the one with a flat surface. Further investigation indicates the wet-etching process for defect removal has an essential impact on photocurrent efficiency. This design demonstrates an innovative approach for water splitting.

  2. Inhibition of photosynthesis and energy dissipation induced by water and high light stresses in rice.

    Science.gov (United States)

    Zhou, Yanhong; Lam, Hon Ming; Zhang, Jianhua

    2007-01-01

    Photoprotection mechanisms of rice plants were studied when its seedlings were subjected to the combined stress of water and high light. The imposition of water stress, induced by PEG 6000 which was applied to roots, resulted in substantial inhibition of stomatal conductance and net photosynthesis under all irradiance treatments. Under high light stress, the rapid decline of photosynthesis with the development of water stress was accompanied by decreases in the maximum velocity of RuBP carboxylation by Rubisco (V(cmax)), the capacity for ribulose-1,5-bisphosphate regeneration (J(max)), Rubisco and stromal FBPase activities, and the quantum efficiency of photosystem II, in the absence of any stomatal limitation of CO(2) supply. Water stress significantly reduced the energy flux via linear electron transport (J(PSII)), but increased light-dependent and DeltapH- and xanthophyll-mediated thermal dissipation (J(NPQ)). It is concluded that the drought-induced inhibition of photosynthesis under different irradiances in the rice was due to both diffusive and metabolic limitations. Metabolic limitation of photosynthesis may be related to the adverse effects of some metabolic processes and the oxidative damage to the chloroplast. Meanwhile, an enhanced thermal dissipation is an important process to minimize the adverse effects of drought and high irradiance when CO(2) assimilation is suppressed.

  3. Conversational Dominance.

    Science.gov (United States)

    Esau, Helmut; Poth, Annette

    Details of conversational behavior can often not be interpreted until the social interaction, including the rights and obligations of the participants, their intent, the topic, etc., has been defined. This paper presents a model of conversation in which the conversational image a person presents in a given conversational situation is a function of…

  4. Carbon Assimilation and Leaf Water Status in Sugar Beet Leaves during a Simulated Natural Light Regimen.

    Science.gov (United States)

    Geiger, D R; Shieh, W J; Lu, L S; Servaites, J C

    1991-11-01

    Carbon assimilation and leaf water status were studied in sugar beet (Beta vulgaris L., Klein E-type multigerm) leaves during a light period in which illumination either increased rapidly to full irradiance or changed gradually in a sinusoidal manner as generally occurs during a natural day. A light regimen that simulated the light of a natural day was produced by adjusting irradiance with a neutral-density filter under the control of a computer. Under this light regimen, photosynthesis, transpiration, and stomatal conductance followed the irradiance pattern very closely and ribulose bisphosphate carboxylase was nearly fully activated. When illumination was increased rapidly at the beginning of a light period, transpiration also increased quickly, causing leaves to wilt to some extent. The activation state of ribulose bisphosphate carboxylase increased to only 52%, but ribulose bisphosphate level was nearly twice as high as during the simulated natural day. In spite of the differences in activation state and ribulose bisphosphate levels, photosynthesis rates were very similar under both regimens. Nevertheless, differences in parameters between leaves under the two irradiance regimens can affect how a plant responds to internal or external factors, and therefore, the rate at which irradiance increases at the beginning of a light period is an important consideration when interpreting data.

  5. Artificial light on water attracts turtle hatchlings during their near shore transit

    Science.gov (United States)

    Thums, Michele; Whiting, Scott D.; Reisser, Julia; Pendoley, Kellie L.; Proietti, Maira; Hetzel, Yasha; Fisher, Rebecca; Meekan, Mark G.

    2016-01-01

    We examined the effect of artificial light on the near shore trajectories of turtle hatchlings dispersing from natal beaches. Green turtle (Chelonia mydas) hatchlings were tagged with miniature acoustic transmitters and their movements tracked within an underwater array of 36 acoustic receivers placed in the near shore zone. A total of 40 hatchlings were tracked, 20 of which were subjected to artificial light during their transit of the array. At the same time, we measured current speed and direction, which were highly variable within and between experimental nights and treatments. Artificial lighting affected hatchling behaviour, with 88% of individual trajectories oriented towards the light and spending, on average, 23% more time in the 2.25 ha tracking array (19.5 ± 5 min) than under ambient light conditions (15.8 ± 5 min). Current speed had little to no effect on the bearing (angular direction) of the hatchling tracks when artificial light was present, but under ambient conditions it influenced the bearing of the tracks when current direction was offshore and above speeds of approximately 32.5 cm s−1. This is the first experimental evidence that wild turtle hatchlings are attracted to artificial light after entering the ocean, a behaviour that is likely to subject them to greater risk of predation. The experimental protocol described in this study can be used to assess the effect of anthropogenic (light pollution, noise, etc.) and natural (wave action, current, wind, moonlight) influences on the in-water movements of sea turtle hatchlings during the early phase of dispersal. PMID:27293795

  6. 3D PIC simulations of electron beams created via reflection of intense laser light from a water target

    CERN Document Server

    Ngirmang, Gregory K; Feister, Scott; Morrison, John T; Chowdhury, Enam A; Frische, Kyle; Roquemore, W M

    2015-01-01

    We present 3D Particle-in-Cell (PIC) modeling of an ultra-intense laser experiment by the Extreme Light group at the Air Force Research Laboratory (AFRL) using the PIC code LSP. This is the first time PIC simulations have been performed in 3D for this experiment which involves an ultra-intense, short-pulse (30 fs) laser interacting with a water jet target at normal incidence. These 3D PIC simulation results are compared to results from 2D(3$v$) PIC simulations for both $5.4\\cdot10^{17}$ W cm$^{-2}$ and $3\\cdot10^{18}$ W cm$^{-2}$ intensities. Comparing the 2D(3$v$) and 3D simulation results, the laser-energy-to-ejected-electron-energy conversion efficiencies were comparable, but the angular distribution of ejected electrons show interesting differences with qualitative differences at higher intensity. An analytic plane-wave model is provided that provides some explanation for the angular distribution and energies of ejected electrons in the 2D(3$v$) simulations. We also performed a 3D simulation with circular...

  7. Transmission of light in deep sea water at the site of the Antares neutrino telescope

    CERN Document Server

    Aguilar, J A; Amram, P; Anghinolfi, M; Anton, G; Anvar, S; Ardellier-Desages, F E; Aslanides, E; Aubert, Jean-Jacques; Azoulay, R; Bailey, D; Basa, S; Battaglieri, M; Becherini, Y; Bellotti, R; Beltramelli, J; Bertin, V; Billault, M; Blaes, R; Blanc, F; Bland, R W; De Botton, N R; Boulesteix, J; Bouwhuis, M C; Brooks, C B; Bradbury, S M; Bruijn, R; Brunner, J; Bugeon, F; Burgio, G F; Cafagna, F; Calzas, A; Caponetto, L; Carmona, E; Carr, J; Cartwright, S L; Cecchini, S; Charvis, P; Circella, M; Colnard, C; Compere, C; Croquette, J; Cooper, S; Coyle, P; Cuneo, S; Damy, G; Van Dantzig, R; Deschamps, A; De Marzo, C; Destelle, J J; De Vita, R; Dinkelspiler, B; Dispau, G; Drougou, J F; Druillole, F; Engelen, J; Favard, S; Feinstein, F; Ferry, S; Festy, D; Fopma, J; Fuda, J L; Gallone, J M; Giacomelli, G; Girard, N; Goret, P; Gournay, J F; Hallewell, G D; Hartmann, B; Heijboer, A; Hello, Y; Hernández-Rey, J J; Herrouin, G; Hossl, J; Hoffmann, C; Hubbard, John R; Jaquet, M; De Jong, M; Jouvenot, F; Kappes, A; Karg, T; Karkar, S; Karolak, M; Katz, U; Keller, P; Kooijman, P; Korolkova, E V; Kouchner, A; Kretschmer, W; Kudryavtsev, V A; Lafoux, H; Lagier, P; Lamare, P; Languillat, J C; Laubier, L; Legou, T; Le Guen, Y; Le Provost, H; Le Van-Suu, A; Lo Nigro, L; Lo Presti, D; Loucatos, Sotirios S; Louis, F; Lyashuk, V; Magnier, P; Marcelin, M; Margiotta, A; Maron, C; Massol, A; Mazéas, F; Mazeau, B; Mazure, A; McMillan, J E; Michel, J L; Millot, C; Milovanovic, A; Montanet, François; Montaruli, T; Morel, J P; Moscoso, L; Nezri, E; Niess, V; Nooren, G J; Ogden, P; Olivetto, C; Palanque-Delabrouille, Nathalie; Payre, P; Petta, C; Pineau, J P; Poinsignon, J; Popa, V; Potheau, R; Pradier, T; Racca, C; Randazzo, N; Real, D; Van Rens, B; Rethore, F; Ripani, M; Roca-Blay, V; Romeyer, A; Rollin, J F; Romita, M; Rose, H J; Ruppi, M; Russo, G V; Sacquin, Yu; Saouter, S; Schuller, J P; Schuster, W; Sokalski, I A; Suvorova, O; Spooner, N J C; Spurio, M; Stolarczyk, T; Stubert, D; Taiuti, M; Thompson, L F; Tilav, S; Usik, A; Valdy, P; Vallage, B; Vaudaine, G; Vernin, P; Virieux, J; Vladimirsky, E; De Vries, G J; De Witt-Huberts, P K A; De Wolf, E; Zaborov, D; Zaccone, Henri; Zakharov, V; Zavatarelli, S; De Dios-Zornoza-Gomez, Juan; Zúñiga, J

    2005-01-01

    The ANTARES neutrino telescope is a large photomultiplier array designed to detect neutrino-induced upward-going muons by their Cherenkov radiation. Understanding the absorption and scattering of light in the deep Mediterranean is fundamental to optimising the design and performance of the detector. This paper presents measurements of blue and UV light transmission at the ANTARES site taken between 1997 and 2000. The derived values for the scattering length and the angular distribution of particulate scattering were found to be highly correlated, and results are therefore presented in terms of an absorption length lambda_abs and an effective scattering length lambda_sct^eff. The values for blue (UV) light are found to be lambda_abs ~ 60(26) m, lambda_sct^eff ~ 265(122) m, with significant (15%) time variability. Finally, the results of ANTARES simulations showing the effect of these water properties on the anticipated performance of the detector are presented.

  8. Meeting Summary Advanced Light Water Reactor Fuels Industry Meeting Washington DC October 27 - 28, 2011

    Energy Technology Data Exchange (ETDEWEB)

    Not Listed

    2011-11-01

    The Advanced LWR Fuel Working Group first met in November of 2010 with the objective of looking 20 years ahead to the role that advanced fuels could play in improving light water reactor technology, such as waste reduction and economics. When the group met again in March 2011, the Fukushima incident was still unfolding. After the March meeting, the focus of the program changed to determining what we could do in the near term to improve fuel accident tolerance. Any discussion of fuels with enhanced accident tolerance will likely need to consider an advanced light water reactor with enhanced accident tolerance, along with the fuel. The Advanced LWR Fuel Working Group met in Washington D.C. on October 72-18, 2011 to continue discussions on this important topic.

  9. International academic program in technologies of light-water nuclear reactors. Phases of development and implementation

    Science.gov (United States)

    Geraskin, N. I.; Glebov, V. B.

    2017-01-01

    The results of implementation of European educational projects CORONA and CORONA II dedicated to preserving and further developing nuclear knowledge and competencies in the area of technologies of light-water nuclear reactors are analyzed. Present article addresses issues of design and implementation of the program for specialized training in the branch of technologies of light-water nuclear reactors. The systematic approach has been used to construct the program for students of nuclear specialties, which corresponding to IAEA standards and commonly accepted nuclear principles recognized in the European Union. Possibilities of further development of the international cooperation between countries and educational institutions are analyzed. Special attention is paid to e-learning/distance training, nuclear knowledge preservation and interaction with European Nuclear Education Network.

  10. Nanoimprint lithography for green water-repellent film derived from biomass with high-light transparency

    Science.gov (United States)

    Takei, Satoshi; Hanabata, Makoto

    2015-03-01

    Newly eco-friendly high light transparency film with plant-based materials was investigated to future development of liquid crystal displays and optical devices with water repellency as a chemical design concept of nanoimprint lithography. This procedure is proven to be suitable for material design and the process conditions of ultraviolet curing nanoimprint lithography for green water-repellent film derived from biomass with high-light transparency. The developed formulation of advanced nanoimprinted materials design derived from lactulose and psicose, and the development of suitable UV nanoimprint conditions produced high resolutions of the conical shaped moth-eye regularly-nanostructure less than approximately 200 nm diameter, and acceptable patterning dimensional accuracy by the replication of 100 times of UV nanoimprint lithography cycles. The newly plant-based materials and the process conditions are expected as one of the defect less nanoimprint lithographic technologies in next generation electronic devices.

  11. Flow-induced vibration for light water reactors. Final progress report, July 1981-September 1981

    Energy Technology Data Exchange (ETDEWEB)

    Torres, M.R.

    1981-11-01

    Flow-Induced Vibration for Light Water Reactors (FIV for LWRs) is a program designed to improve the FIV performance of light water reactors through the development of design criteria, analytical models for predicting behavior of components, and general scaling laws to improve the accuracy of reduced-scale tests, and through the identification of high FIV risk areas. The program is managed by the General Electric Nuclear Power Systems Engineering Department and has three major contributors: General Electric Nuclear Power Systems Engineering Department (NPSED), General Electric Corporate Research and Development (CR and D) and Argonne National Laboratory (ANL). The program commenced December 1, 1976. This progress report summarizes the accomplishments achieved during the final period from July 1981 to September 1981. This is the last quarterly progress report to be issued for this program.

  12. Effect of atmospheric environment on the attenuation coefficient of light in water

    CERN Document Server

    Liu, Juan; Tang, Yijun; Zhu, Kaixing; Ge, Yuan; Chen, Xuegang; He, Xingdao; Liu, Dahe

    2014-01-01

    The attenuation coefficient of 532 nm light in water under different atmospheric conditions was investigated. Measurements were made over a two-year period at the same location and show that the attenuation coefficient is significantly influenced by the atmospheric environment. It is lowest when the atmospheric pressure is high and temperature is low, and is highest when the atmospheric pressure is low and temperature is high. The maximum attenuation coefficient of pure water in these studies was about three times the minimum value. The mechanism of the phenomena is discussed. These results are also important in underwater acoustics.

  13. DOE/NNSA perspective safeguard by design: GEN III/III+ light water reactors and beyond

    Energy Technology Data Exchange (ETDEWEB)

    Pan, Paul Y [Los Alamos National Laboratory

    2010-12-10

    An overview of key issues relevant to safeguards by design (SBD) for GEN III/IV nuclear reactors is provided. Lessons learned from construction of typical GEN III+ water reactors with respect to SBD are highlighted. Details of SBD for safeguards guidance development for GEN III/III+ light water reactors are developed and reported. This paper also identifies technical challenges to extend SBD including proliferation resistance methodologies to other GEN III/III+ reactors (except HWRs) and GEN IV reactors because of their immaturity in designs.

  14. The optical properties of greenlandic coastal waters: Modelling light penetration in a changing climate

    DEFF Research Database (Denmark)

    Stedmon, Colin; Markager, S.S.; Pedersen, T.J.

    Greenlandic fjords are very productive and pristine ecosystems, which the local population is both intrinsically linked to and dependent on through heritage, industrial fisheries, and tourism. The availability and spectral quality of light are key parameters controlling the productivity of these ...... with a considerable amount of terrestrial dissolved organic matter (DOM) from the Arctic Ocean; and Godthåbsfjord a fjord in Southwest Greenland where strong tides ensure a regular supply of warm shelf water which melt glacial ice before it can leave the fjord...... depending on the influence of shelf water entering the fjords, extent of glacial ice melt and the size and vertical distribution of the phytoplankton biomass. In this study the data from two contrasting sites are compared: Young Sound, a fjord system in Northeast Greenland that imports shelf waters...... of these waters. Although solar elevation and sea ice cover play an important role, during the summer month’s light is also regulated by water constituents such as dissolved and particulate organic matter, phytoplankton and suspended sediments. The relative importance of each of these constituents varies...

  15. Research on physical and chemical parameters of coolant in Light-Water Reactors

    Energy Technology Data Exchange (ETDEWEB)

    Reis, Isabela C.; Mesquita, Amir Z., E-mail: icr@cdtn.br, E-mail: amir@cdtn.br [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEM-MG), Belo Horizonte, MG (Brazil)

    2015-07-01

    The coolant radiochemical monitoring of light-water reactors, both power reactor as research reactors is one most important tasks of the system safe operation. The last years have increased the interest in the coolant chemical studying to optimize the process, to minimize the corrosion, to ensure the primary system materials integrity, and to reduce the workers exposure radiation. This paper has the objective to present the development project in Nuclear Technology Development Center (CDTN), which aims to simulate the primary water physical-chemical parameters of light-water-reactors (LWR). Among these parameters may be cited: the temperature, the pressure, the pH, the electric conductivity, and the boron concentration. It is also being studied the adverse effects that these parameters can result in the reactor integrity. The project also aims the mounting of a system to control and monitoring of temperature, electric conductivity, and pH of water in the Installation of Test in Accident Conditions (ITCA), located in the Thermal-Hydraulic Laboratory at CDTN. This facility was widely used in the years 80/90 for commissioning of several components that were installed in Angra 2 containment. In the test, the coolant must reproduce the physical and chemical conditions of the primary. It is therefore fundamental knowledge of the main control parameters of the primary cooling water from PWR reactors. Therefore, this work is contributing, with the knowledge and the reproduction with larger faithfulness of the reactors coolant in the experimental circuits. (author)

  16. Molecular water oxidation catalysis

    CERN Document Server

    Llobet, Antoni

    2014-01-01

    Photocatalytic water splitting is a promising strategy for capturing energy from the sun by coupling light harvesting and the oxidation of water, in order to create clean hydrogen fuel. Thus a deep knowledge of the water oxidation catalysis field is essential to be able to come up with useful energy conversion devices based on sunlight and water splitting. Molecular Water Oxidation Catalysis: A Key Topic for New Sustainable Energy Conversion Schemes presents a comprehensive and state-of-the-art overview of water oxidation catalysis in homogeneous phase, describing in detail the most importan

  17. Modelling of underwater light fields in turbid and eutrophic waters: application and validation with experimental data

    Directory of Open Access Journals (Sweden)

    B. Sundarabalan

    2014-09-01

    Full Text Available A reliable radiative transfer model is an essential and indispensable tool for understanding of the radiative transfer processes in homogenous and layered waters, analyzing measurements made by radiance sensors and developing remote sensing algorithms to derive meaningful physical quantities and biogeochemical variables in turbid and productive coastal waters. Existing radiative transfer models have been designed to be applicable to either homogenous waters or inhomogeneous waters. To overcome such constraints associated with these models, this study presents a radiative transfer model that treats a homogenous layer as a diffuse part and an inhomogeneous layer as a direct part in the water column and combines these two parts appropriately in order to generate more reliable underwater light field data such as upwelling radiance (Lu, downwelling irradiance (Ed and upwelling irradiance (Eu. The diffuse model assumes the inherent optical properties (IOPs to be vertically continuous and the light fields to exponentially decrease with the depth, whereas the direct part considers the water column to be vertically inhomogeneous (layer-by-layer phenomena with the vertically varying phase function. The surface and bottom boundary conditions, source function due to chlorophyll and solar incident geometry are also included in the present RT model. The performance of this model is assessed in a variety of waters (clear, turbid and eutrophic using the measured radiometric data. The present model shows an advantage in terms of producing accurate Lu, Ed and Eu profiles (in spatial domain in different waters determined by both homogenous and inhomogeneous conditions. The feasibility of predicting these underwater light fields based on the remotely estimated IOP data is also examined using the present RT model. For this application, vertical profiles of the water constituents and IOPs are estimated by empirical models based on our in-situ data. The present RT

  18. Germination of Jacaranda mimosifolia (D. Don - Bignoniaceae seeds: effects of light, temperature and water stress

    Directory of Open Access Journals (Sweden)

    Fábio Socolowski

    2004-09-01

    Full Text Available Investigations were carried out to study the effect of light, temperature and water stress on the germination of seeds of Jacaranda mimosifolia which showed the minimum and maximum germination temperature at 15 and 40º C, respectively. The optimum temperature was 25º C with high percentage and germination rate. Slight promotive effect of white light was observed. Under water stress conditions the effect of light was high but at optimum temperature no effect of light was observed. At -0.9MPa few seeds germinated.Sementes de Jacaranda mimosifolia apresentaram temperaturas mínima e máxima de germinação a 15 e a 40º C, respectivamente. A temperatura ótima foi de 25º C com alta porcentagem e velocidade de germinação. Uma pequena estimulação da germinação pela luz foi observada. Sob condições de estresse de água o efeito promotor da luz foi maior, mas na temperatura ótima este efeito da luz não foi observado. No potencial de água de -0,9MPa praticamente nenhuma semente germinou.

  19. White light phase shifting interferometry and color fringe analysis for the detection of contaminants in water

    Science.gov (United States)

    Dubey, Vishesh; Singh, Veena; Ahmad, Azeem; Singh, Gyanendra; Mehta, Dalip Singh

    2016-03-01

    We report white light phase shifting interferometry in conjunction with color fringe analysis for the detection of contaminants in water such as Escherichia coli (E.coli), Campylobacter coli and Bacillus cereus. The experimental setup is based on a common path interferometer using Mirau interferometric objective lens. White light interferograms are recorded using a 3-chip color CCD camera based on prism technology. The 3-chip color camera have lesser color cross talk and better spatial resolution in comparison to single chip CCD camera. A piezo-electric transducer (PZT) phase shifter is fixed with the Mirau objective and they are attached with a conventional microscope. Five phase shifted white light interferograms are recorded by the 3-chip color CCD camera and each phase shifted interferogram is decomposed into the red, green and blue constituent colors, thus making three sets of five phase shifted intererograms for three different colors from a single set of white light interferogram. This makes the system less time consuming and have lesser effect due to surrounding environment. Initially 3D phase maps of the bacteria are reconstructed for red, green and blue wavelengths from these interferograms using MATLAB, from these phase maps we determines the refractive index (RI) of the bacteria. Experimental results of 3D shape measurement and RI at multiple wavelengths will be presented. These results might find applications for detection of contaminants in water without using any chemical processing and fluorescent dyes.

  20. Measurement of the group velocity of light in sea water at the ANTARES site

    Science.gov (United States)

    Adrián-Martínez, S.; Al Samarai, I.; Albert, A.; André, M.; Anghinolfi, M.; Anton, G.; Anvar, S.; Ardid, M.; Assis Jesus, A. C.; Astraatmadja, T.; Aubert, J.-J.; Baret, B.; Basa, S.; Bertin, V.; Biagi, S.; Bigi, A.; Bigongiari, C.; Bogazzi, C.; Bou-Cabo, M.; Bouhou, B.; Bouwhuis, M. C.; Brunner, J.; Busto, J.; Camarena, F.; Capone, A.; Cârloganu, C.; Carminati, G.; Carr, J.; Cecchini, S.; Charif, Z.; Charvis, Ph.; Chiarusi, T.; Circella, M.; Costantini, H.; Coyle, P.; Curtil, C.; De Bonis, G.; Decowski, M. P.; Dekeyser, I.; Deschamps, A.; Distefano, C.; Donzaud, C.; Dornic, D.; Dorosti, Q.; Drouhin, D.; Eberl, T.; Emanuele, U.; Enzenhöfer, A.; Ernenwein, J.-P.; Escoffier, S.; Fermani, P.; Ferri, M.; Flaminio, V.; Folger, F.; Fritsch, U.; Fuda, J.-L.; Galatà, S.; Gay, P.; Geyer, K.; Giacomelli, G.; Giordano, V.; Gómez-González, J. P.; Graf, K.; Guillard, G.; Halladjian, G.; Hallewell, G.; van Haren, H.; Hartman, J.; Heijboer, A. J.; Hello, Y.; Hernández-Rey, J. J.; Herold, B.; Hößl, J.; Hsu, C. C.; de Jong, M.; Kadler, M.; Kalekin, O.; Kappes, A.; Katz, U.; Kavatsyuk, O.; Kooijman, P.; Kopper, C.; Kouchner, A.; Kreykenbohm, I.; Kulikovskiy, V.; Lahmann, R.; Lamare, P.; Larosa, G.; Lattuada, D.; Lefèvre, D.; Lim, G.; Lo Presti, D.; Loehner, H.; Loucatos, S.; Mangano, S.; Marcelin, M.; Margiotta, A.; Martínez-Mora, J. A.; McMillan, J. E.; Meli, A.; Montaruli, T.; Moscoso, L.; Motz, H.; Neff, M.; Nezri, E.; Palioselitis, D.; Păvălaş, G. E.; Payet, K.; Payre, P.; Petrovic, J.; Piattelli, P.; Picot-Clemente, N.; Popa, V.; Pradier, T.; Presani, E.; Racca, C.; Reed, C.; Riccobene, G.; Richardt, C.; Richter, R.; Rivière, C.; Robert, A.; Roensch, K.; Rostovtsev, A.; Ruiz-Rivas, J.; Rujoiu, M.; Russo, G. V.; Salesa, F.; Samtleben, D. F. E.; Sapienza, P.; Schöck, F.; Schuller, J.-P.; Schüssler, F.; Seitz, T.; Shanidze, R.; Simeone, F.; Spies, A.; Spurio, M.; Steijger, J. J. M.; Stolarczyk, Th.; Sánchez-Losa, A.; Taiuti, M.; Tamburini, C.; Thompson, L. F.; Toscano, S.; Vallage, B.; Van Elewyck, V.; Vannoni, G.; Vecchi, M.; Vernin, P.; Wagner, S.; Wijnker, G.; Wilms, J.; de Wolf, E.; Yepes, H.; Zaborov, D.; Zornoza, J. D.; Zúñiga, J.

    2012-04-01

    The group velocity of light has been measured at eight different wavelengths between 385 nm and 532 nm in the Mediterranean Sea at a depth of about 2.2 km with the ANTARES optical beacon systems. A parametrisation of the dependence of the refractive index on wavelength based on the salinity, pressure and temperature of the sea water at the ANTARES site is in good agreement with these measurements.

  1. Literature search on Light Water Reactor (LWR) fuel and absorber rod fabrication, 1960--1976

    Energy Technology Data Exchange (ETDEWEB)

    Sample, C R [comp.

    1977-02-01

    A literature search was conducted to provide information supporting the design of a conceptual Light Water Reactor (LWR) Fuel Fabrication plant. Emphasis was placed on fuel processing and pin bundle fabrication, effects of fuel impurities and microstructure on performance and densification, quality assurance, absorber and poison rod fabrication, and fuel pin welding. All data have been taken from publicly available documents, journals, and books. This work was sponsored by the Finishing Processes-Mixed Oxide (MOX) Fuel Fabrication Studies program at HEDL.

  2. Measurement of the Group Velocity of Light in Sea Water at the ANTARES Site

    CERN Document Server

    Adrián-Martínez, S; Albert, A; André, M; Anghinolfi, M; Anton, G; Anvar, S; Ardid, M; Jesus, A C Assis; Astraatmadja, T; Aubert, J-J; Baret, B; Basa, S; Bertin, V; Biagi, S; Bigi, A; Bigongiari, C; Bogazzi, C; Bou-Cabo, M; Bouhou, B; Bouwhuis, M C; Brunner, J; Busto, J; Camarena, F; Capone, A; Carloganu, C; Carminati, G; Carr, J; Cecchini, S; Charif, Z; Charvis, Ph; Chiarusi, T; Circella, M; Costantini, H; Coyle, P; Curtil, C; De Bonis, G; Decowski, M P; Dekeyser, I; Deschamps, A; Distefano, C; Donzaud, C; Dornic, D; Dorosti, Q; Drouhin, D; Eberl, T; Emanuele, U; Enzenhöfer, A; Ernenwein, J-P; Escoffier, S; Fermani, P; Ferri, M; Flaminio, V; Folger, F; Fritsch, U; Fuda, J-L; Galatá, S; Gay, P; Geyer, K; Giacomelli, G; Giordano, V; Gómez-González, J P; Graf, K; Guillard, G; Halladjian, G; Hallewell, G; van Haren, H; Hartman, J; Heijboer, A J; Hello, Y; Hernández-Rey, J J; Herold, B; Hößl, J; Hsu, C C; de Jong, M; Kadler, M; Kalekin, O; Kappes, A; Katz, U; Kavatsyuk, O; Kooijman, P; Kopper, C; Kouchner, A; Kreykenbohm, I; Kulikovskiy, V; Lahmann, R; Lamare, P; Larosa, G; Lattuada, D; Lefévre, D; Lim, G; Presti, D Lo; Loehner, H; Loucatos, S; Mangano, S; Marcelin, M; Margiotta, A; Martínez-Mora, J A; Meli, A; Montaruli, T; Moscoso, L; Motz, H; Neff, M; Nezri, E; Palioselitis, D; Păvălaş, G E; Payet, K; Payre, P; Petrovic, J; Piattelli, P; Picot-Clemente, N; Popa, V; Pradier, T; Presani, E; Racca, C; Reed, C; Riccobene, G; Richardt, C; Richter, R; Riviére, C; Robert, A; Roensch, K; Rostovtsev, A; Ruiz-Rivas, J; Rujoiu, M; Russo, G V; Salesa, F; Samtleben, D F E; Sapienza, P; Schöck, F; Schuller, J-P; Schüssler, F; Seitz, T; Shanidze, R; Simeone, F; Spies, A; Spurio, M; Steijger, J J M; Stolarczyk, Th; Sánchez-Losa, A; Taiuti, M; Tamburini, C; Toscano, S; Vallage, B; Van Elewyck, V; Vannoni, G; Vecchi, M; Vernin, P; Wagner, S; Wijnker, G; Wilms, J; de Wolf, E; Yepes, H; Zaborov, D; Zornoza, J D; Zúñiga, J

    2011-01-01

    The group velocity of light has been measured at eight different wavelengths between 385 nm and 532 nm in the Mediterranean Sea at a depth of about 2.2 km with the ANTARES optical beacon systems. A parametrisation of the dependence of the refractive index on wavelength based on the salinity, pressure and temperature of the sea water at the ANTARES site is in good agreement with these measurements.

  3. Research and Development Methodology for Practical Use of Accident Tolerant Fuel in Light Water Reactors

    OpenAIRE

    Masaki Kurata

    2016-01-01

    Research and development (R&D) methodology for the practical use of accident tolerant fuel (ATF) in commercial light water reactors is discussed in the present review. The identification and quantification of the R&D-metrics and the attribute of candidate ATF-concepts, recognition of the gap between the present R&D status and the targeted practical use, prioritization of the R&D, and technology screening schemes are important for achieving a common understanding on technology screening proces...

  4. Development Status of Accident-tolerant Fuel for Light Water Reactors in Korea

    OpenAIRE

    Hyun-Gil Kim; Jae-Ho Yang; Weon-Ju Kim; Yang-Hyun Koo

    2016-01-01

    For a long time, a top priority in the nuclear industry was the safe, reliable, and economic operation of light water reactors. However, the development of accident-tolerant fuel (ATF) became a hot topic in the nuclear research field after the March 2011 events at Fukushima, Japan. In Korea, innovative concepts of ATF have been developing to increase fuel safety and reliability during normal operations, operational transients, and also accident events. The microcell UO2 and high-density compo...

  5. Growth of and fumitremorgin production by Neosartorya fischeri as affected by temperature, light, and water activity.

    OpenAIRE

    Nielsen, P V; Beuchat, L. R.; Frisvad, J.C.

    1988-01-01

    The effects of temperature, light, and water activity (aw) on the growth and fumitremorgin production of a heat-resistant mold, Neosartorya fischeri, cultured on Czapek Yeast Autolysate agar (CYA) were studied for incubation periods of up to 74 days. Colonies were examined visually, and extracts of mycelia and CYA on which the mold was cultured were analyzed for mycotoxin content by high-performance liquid chromatography. Growth always resulted in the production of the tremorgenic mycotoxins ...

  6. Modeling relations between the composition and properties of French light water reactor waste containment glass

    Energy Technology Data Exchange (ETDEWEB)

    Ghaleb, D.; Dussossoy, J.L.; Fillet, C.; Pacaud, F.; Jacquet-Francillon, N.

    1994-12-31

    Models have been developed to calculate the density, molten-state viscosity and initial corrosion rate according to the chemical composition of glass formulations used to vitrify high-level fission product solutions from reprocessed light water reactor fuel. Developed from other published work, these models have been adapted to allow for the effects of platinoid (Ru, Pd, Rh) inclusions on the molten glass rheology. (authors). 15 refs., 10 figs., 1 tab.

  7. Establishment of a Hub for the Light Water Reactor Sustainability Online Monitoring Community

    Energy Technology Data Exchange (ETDEWEB)

    Nancy J. Lybeck; Magdy S. Tawfik; Binh T. Pham

    2011-08-01

    Implementation of online monitoring and prognostics in existing U.S. nuclear power plants will involve coordinating the efforts of national laboratories, utilities, universities, and private companies. Internet-based collaborative work environments provide necessary communication tools to facilitate interaction between geographically diverse participants. Available technologies were considered, and a collaborative workspace was established at INL as a hub for the light water reactor sustainability online monitoring community.

  8. Overview of the US Department of Energy Light Water Reactor Sustainability Program

    Energy Technology Data Exchange (ETDEWEB)

    K. A. McCarthy; D. L. Williams; R. Reister

    2012-05-01

    The US Department of Energy Light Water Reactor Sustainability Program is focused on the long-term operation of US commercial power plants. It encompasses two facets of long-term operation: (1) manage the aging of plant systems, structures, and components so that nuclear power plant lifetimes can be extended and the plants can continue to operate safely, efficiently, and economically; and (2) provide science-based solutions to the nuclear industry that support implementation of performance improvement technologies. An important aspect of the Light Water Reactor Sustainability Program is partnering with industry and the Nuclear Regulatory Commission to support and conduct the long-term research needed to inform major component refurbishment and replacement strategies, performance enhancements, plant license extensions, and age-related regulatory oversight decisions. The Department of Energy research, development, and demonstration role focuses on aging phenomena and issues that require long-term research and/or unique Department of Energy laboratory expertise and facilities and are applicable to all operating reactors. This paper gives an overview of the Department of Energy Light Water Reactor Sustainability Program, including vision, goals, and major deliverables.

  9. Visible light active zeolite-based photocatalysts for hydrogen evolution from water

    Energy Technology Data Exchange (ETDEWEB)

    Dubey, Nidhi; Rayalu, Sadhana S.; Labhsetwar, Nitin K.; Devotta, Sukumar [Environmental Materials Unit, National Environmental Engineering Research Institute (NEERI), Nehru Marg, Nagpur, Maharashtra 440020 (India)

    2008-11-15

    Hydrogen, considered as the fuel for future can be produced from non-conventional, renewable and plentiful source like water. Novel zeolite-based materials that show photocatalytic properties in the visible light have been synthesized by incorporating titanium dioxide (TiO{sub 2}), heteropolyacid (HPA) and transition metals like cobalt (Co). These materials show high efficiency for water splitting under visible light irradiation. Hydrogen (H{sub 2}) generation to the tune of 2730 {mu}mol/h/g TiO{sub 2} has been obtained for the composite photocatalyst synthesized. Platinum (Pt) doping has also been attempted in this composite photocatalyst, however, no substantial enhancement in hydrogen generation was observed. The high efficiency of the composite photocatalyst suggests that the TiO{sub 2} which gets effectively dispersed and stabilized on the surface of zeolite works synergistically with transition metal like cobalt and heteropolyacid to make the material active in visible light for photoreduction of water to hydrogen. The aluminosilicate framework of zeolite also contributes towards delayed charge separation. This composite photocatalyst shows improvement in hydrogen evolution rate over other TiO{sub 2} based visibly active photocatalyst reported. (author)

  10. Oak Ridge National Laboratory Support of Non-light Water Reactor Technologies: Capabilities Assessment for NRC Near-term Implementation Action Plans for Non-light Water Reactors

    Energy Technology Data Exchange (ETDEWEB)

    Belles, Randy [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Jain, Prashant K. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Powers, Jeffrey J. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2017-04-01

    The Oak Ridge National Laboratory (ORNL) has a rich history of support for light water reactor (LWR) and non-LWR technologies. The ORNL history involves operation of 13 reactors at ORNL including the graphite reactor dating back to World War II, two aqueous homogeneous reactors, two molten salt reactors (MSRs), a fast-burst health physics reactor, and seven LWRs. Operation of the High Flux Isotope Reactor (HFIR) has been ongoing since 1965. Expertise exists amongst the ORNL staff to provide non-LWR training; support evaluation of non-LWR licensing and safety issues; perform modeling and simulation using advanced computational tools; run laboratory experiments using equipment such as the liquid salt component test facility; and perform in-depth fuel performance and thermal-hydraulic technology reviews using a vast suite of computer codes and tools. Summaries of this expertise are included in this paper.

  11. Competition for light and water in a coupled soil-plant system

    Science.gov (United States)

    Manoli, Gabriele; Huang, Cheng-Wei; Bonetti, Sara; Domec, Jean-Christophe; Marani, Marco; Katul, Gabriel

    2017-10-01

    It is generally accepted that resource availability shapes the structure and function of many ecosystems. Within the soil-plant-atmosphere (SPA) system, resource availability fluctuates in space and time whereas access to resources by individuals is further impacted by plant-to-plant competition. Likewise, transport and transformation of resources within an individual plant is governed by numerous interacting biotic and abiotic processes. The work here explores the co-limitations on water losses and carbon uptake within the SPA arising from fluctuating resource availability and competition. In particular, the goal is to unfold the interplay between plant access and competition for water and light, as well as the impact of transport/redistribution processes on leaf-level carbon assimilation and water fluxes within forest stands. A framework is proposed that couples a three-dimensional representation of soil-root exchanges with a one-dimensional description of stem water flow and storage, canopy photosynthesis, and transpiration. The model links soil moisture redistribution, root water uptake, xylem water flow and storage, leaf potential and stomatal conductance as driven by supply and demand for water and carbon. The model is then used to investigate plant drought resilience of overstory-understory trees simultaneously competing for water and light. Simulation results reveal that understory-overstory interactions increase ecosystem resilience to drought (i.e. stand-level carbon assimilation rates and water fluxes can be sustained at lower root-zone soil water potentials). This resilience enhancement originates from reduced transpiration (due to shading) and hydraulic redistribution in soil supporting photosynthesis over prolonged periods of drought. In particular, the presence of different rooting systems generates localized hydraulic redistribution fluxes that sustain understory transpiration through overstory-understory interactions. Such complex SPA dynamics

  12. Influence of Type of Electric Bright Light on the Attraction of the African Giant Water Bug, Lethocerus indicus (Hemiptera: Belostomatidae

    Directory of Open Access Journals (Sweden)

    Luke Chinaru Nwosu

    2012-01-01

    Full Text Available This study investigated the influence of type of electric bright light (produced by fluorescent light tube and incandescent light bulb on the attraction of the African giant water bug, Lethocerus indicus (Hemiptera: Belostomatidae. Four fluorescent light tubes of 15 watts each, producing white-coloured light and four incandescent light bulbs of 60 watts each, producing yellow-coloured light, but both producing the same amount of light, were varied and used for the experiments. Collections of bugs at experimental house were done at night between the hours of 8.30 pm and 12 mid-night on daily basis for a period of four months per experiment in the years 2008 and 2009. Lethocerus indicus whose presence in any environment has certain implications was the predominant belostomatid bug in the area. Use of incandescent light bulbs in 2009 significantly attracted more Lethocerus indicus 103 (74.6% than use of fluorescent light tubes 35 (25.41% in 2008 [4.92=0.0001]. However, bug’s attraction to light source was not found sex dependent [>0.05; (>0.18=0.4286 and >0.28=0.3897]. Therefore, this study recommends the use of fluorescent light by households, campgrounds, and other recreational centres that are potentially exposed to the nuisance of the giant water bugs. Otherwise, incandescent light bulbs should be used when it is desired to attract the presence of these aquatic bugs either for food or scientific studies.

  13. Self-propagating solar light reduction of graphite oxide in water

    Science.gov (United States)

    Todorova, N.; Giannakopoulou, T.; Boukos, N.; Vermisoglou, E.; Lekakou, C.; Trapalis, C.

    2017-01-01

    Graphite Oxide (GtO) is commonly used as an intermediate material for preparation of graphene in the form of reduced graphene oxide (rGO). Being a semiconductor with tunable band gap rGO is often coupled with various photocatalysts to enhance their visible light activity. The behavior of such rGO-based composites could be affected after prolonged exposure to solar light. In the present work, the alteration of the GtO properties under solar light irradiation is investigated. Water dispersions of GtO manufactured by oxidation of natural graphite via Hummers method were irradiated into solar light simulator for different periods of time without addition of catalysts or reductive agent. The FT-IR analysis of the treated dispersions revealed gradual reduction of the GtO with the increase of the irradiation time. The XRD, FT-IR and XPS analyses of the obtained solid materials confirmed the transition of GtO to rGO under solar light irradiation. The reduction of the GtO was also manifested by the CV measurements that revealed stepwise increase of the specific capacitance connected with the restoration of the sp2 domains. Photothermal self-propagating reduction of graphene oxide in aqueous media under solar light irradiation is suggested as a possible mechanism. The self-photoreduction of GtO utilizing solar light provides a green, sustainable route towards preparation of reduced graphene oxide. However, the instability of the GtO and partially reduced GO under irradiation should be considered when choosing the field of its application.

  14. Gas-liquid-liquid equilibria in mixtures of water, light gases, and hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Chao, K.C.

    1990-01-01

    Phase equilibrium in mixtures of water + light gases and water + heavy hydrocarbons has been investigated with the development of new local composition theory, new equations of state, and new experimental data. The preferential segregation and orientation of molecules due to different energies of molecular interaction has been simulated with square well molecules. Extensive simulation has been made for pure square well fluids and mixtures to find the local composition at wide ranges of states. A theory of local composition has been developed and an equation of state has been obtained for square well fluids. The new local composition theory has been embedded in several equations of state. The pressure of water is decoupled into a polar pressure and non-polar pressure according to the molecular model of water of Jorgensen et al. The polar pressure of water is combined with the BACK equation for the general description of polar fluids and their mixtures. Being derived from the steam table, the Augmented BACK equation is particularly suited for mixtures of water + non-polar substances such as the hydrocarbons. The hydrophobic character of the hydrocarbons had made their mixtures with water a special challenge. A new group contribution equation of state is developed to describe phase equilibrium and volumetric behavior of fluids while requiring only to know the molecular structure of the components. 15 refs., 1 fig.

  15. Volumetric dimensional changes of dental light-cured dimethacrylate resins after sorption of water or ethanol.

    Science.gov (United States)

    Sideridou, Irini D; Karabela, Maria M; Vouvoudi, Evagelia Ch

    2008-08-01

    This study evaluated the influence of water and ethanol sorption on the volumetric dimensional changes of resins prepared by light curing of Bis-GMA, Bis-EMA, UDMA, TEGDMA or D(3)MA. The resin specimens (15mm diameterx1mm height) were immersed in water or ethanol 37+/-1 degrees C for 30 days. Volumetric changes of specimens were obtained via accurate mass measurements using Archimedes principle. The specimens were reconditioned by dry storage in an oven at 37+/-1 degrees C until constant mass was obtained and then immersed in water or ethanol for 30 days. The volumetric changes of specimens were determined and compared to those obtained from the first sorption. Resins showed similar volume increase during the first and second sorptions of water or ethanol. The volume increase due to water absorption is in the following order: poly-TEGDMA>poly-Bis-GMA>poly-UDMA>poly-Bis-EMA>poly-D(3)MA. On the contrary, the order in ethanol is poly-Bis-GMA>poly-UDMA>poly-TEGDMA>poly-Bis-EMA approximately poly-D(3)MA. The volume increase was found to depend linearly on the amount of water or ethanol absorbed. In the choice of monomers for preparation of composite resin matrix the volume increase in the resin after immersion in water or ethanol must be taken into account. Resins of Bis-EMA and D(3)MA showed the lowest values.

  16. Underwater light field determined by water constituents in highly turbid water: the case of Taihu lake

    Directory of Open Access Journals (Sweden)

    Chang-Chun Huang

    2013-02-01

    Full Text Available The relationships between optical properties and water constituents in highly turbid productivewater were studied on the basis of the multiple bio-optical measurements and samplings of water constituents made during five cruises from 2006 to 2008 in Taihu lake. Taihu lake is a high dynamic ratio [(square root of area/depth] inland shallow lake. The spatial and temporal variation of water constituents and optical properties is significant. The inorganic suspended matter (ISMhas become the primary constituent in Taihu lake: its average percentage can reach 65.21%. The concentration of ISM is highly correlated to the optical properties in Taihu lake due to the sediment resuspension. Consequently, the ISM can be taken into account as an important optically-active constituent in Taihu lake. Resuspended sediments also lead to a poor correlation between scattering optical property and chlorophyll-a concentration (CChl-a. However, empirical relationship between the CChl-a and phytoplankton absorption coefficient at 675 nm is still valid when the package effect is removed. The parameters of linear equation in the present study have slight temporal variation, especially for the relationship between inherent optical properties (IOPs and concentration of total suspended matter (TSM. The relationship between apparent optical property (AOP (diffuse attenuation coefficient of particle, Kdbio and ISM has been examined as well. The Kdbio is strongly affected by ISM, and correlates to it with linear function. Thedifference between specific diffuse attenuation coefficients of organic [K*dOSM(λ] and inorganic [K*dISM(λ] particles is significant. K*dOSM(λ includes the absorption property of chlorophyll-a (chl-a at 675 nm, which is much higher than that of K*dISM(λ. This indicates that the attenuation ability of OSM is stronger than that of ISM although the Kdbio induced by large concentration of ISM is bigger than the Kdbio induced by small concentration of OSM

  17. Light absorption and partitioning in Arctic Ocean surface waters: impact of multi year ice melting

    Directory of Open Access Journals (Sweden)

    S. Bélanger

    2013-03-01

    Full Text Available Ice melting in the Arctic Ocean exposes the surface water to more radiative energy with poorly understood effects on photo-biogeochemical processes and heat deposition in the upper ocean. In August 2009, we documented the vertical variability of light absorbing components at 37 stations located in the southeastern Beaufort Sea including both Mackenzie river-influenced waters and polar mixed layer waters. We found that melting multi-year ice released significant amount of non-algal particulates (NAP near the sea surface relative to sub-surface waters. NAP absorption coefficients at 440 nm (aNAP(440 immediately below the sea surface (0- were on average 3-fold (up to 10-fold higher compared to sub-surface values measured at 2–3 m depth. The impact of this unusual feature on the light transmission and remote sensing reflectance (Rrs was further examined using a radiative transfer model. A 10-fold particle enrichment homogeneously distributed in the first meter of the water column slightly reduced photosynthetically available and usable radiation (PAR and PUR by ~6% and ~8%, respectively, relative to a fully homogenous water column with low particles concentration. In terms of Rrs, the particle enrichment significantly flattered the spectrum by reducing the Rrs by up to 20% in the blue-green spectral region (400–550 nm. These results highlight the impact of melt water on the concentration of particles at sea surface, and the need for considering nonuniform vertical distribution of particles in such systems when interpreting remotely sensed ocean color. Spectral slope of aNAP spectra calculated in the UV domain decreased with depth suggesting that this parameter is sensitive to detritus composition and/or diagenesis state (e.g., POM photobleaching.

  18. Application of water-assisted pulsed light treatment to decontaminate raspberries and blueberries from Salmonella.

    Science.gov (United States)

    Huang, Yaoxin; Sido, Robert; Huang, Runze; Chen, Haiqiang

    2015-09-02

    We developed and evaluated a small scaled-up water-assisted pulsed light (WPL) system, in which berries were washed in a flume washer while being irradiated by pulsed light (PL). Hydrogen peroxide (H2O2) was used in combination with PL as an advanced oxidation process and chlorine wash was used as a control. The effects of organic load, water turbidity, berry type and PL energy output on the inactivation of Salmonella using the WPL system were investigated. The combination of WPL and 1% H2O2 (WPL-H2O2) was the most effective treatment which reduced Salmonella on raspberries and blueberries by 4.0 and >5.6logCFU/g, respectively, in clear water. When high organic load and SiO2, as a soil simulator, were added in wash water, the free chlorine level in chlorinated water decreased significantly (P0.05) was observed for the decontamination efficacy of 1-min WPL-H2O2 treatment. Even in the presence of high organic load and water turbidity, no viable bacterial cells were recovered from the wash water, which showed that WPL-H2O2 could effectively prevent the risk of cross-contamination during treatment. Taken together, 1-min WPL treatment without H2O2 could provide a chemical free alternative to chlorine washing with similar and in some cases significantly higher bactericidal efficacy. Compared with chlorine washing, the combination of WPL and H2O2 resulted in significantly higher (P<0.05) reduction of Salmonella on berries, providing a novel intervention for processing of small berries intended for fresh-cut and frozen berry products.

  19. The infrared light curve of Periodic Comet Halley 1986 III and its relationship to the visual light curve, C2, and water production rates

    Science.gov (United States)

    Morris, Charles S.; Hanner, Martha S.

    1993-01-01

    The near-IR light curve of Periodic Comet Halley 1986 III is analyzed and compared with C2 production, water production, and the visual light curve. This is the most complete IR light curve compiled to date for any comet. The scattering phase function at small sun-comet-earth angles is shown to affect the slope of near-IR light curve significantly. P/Halley's dust production, as inferred from the IR light curve showed an increased production rate near perihelion which appears to be correlated with the onset of significant jet activity. The near-IR light curve, visual light curve, C2, and water production rates displayed different heliocentric variations, suggesting that one parameter cannot be accurately estimated from another. This is particularly true of the early preperihelion visual light curve. A peak of 0.3-0.5 magnitude in the visual magnitude, representing the integrated brightness of the comet's visible coma, lagged the other parameters by about a day. The near-IR color, J-H, was less red during periods of strong dust activity.

  20. A triplet-triplet annihilation based up-conversion process investigated in homogeneous solutions and oil-in-water microemulsions of a surfactant.

    Science.gov (United States)

    Penconi, Marta; Gentili, Pier Luigi; Massaro, Giuseppina; Elisei, Fausto; Ortica, Fausto

    2014-01-01

    The triplet-triplet annihilation based up-conversion process, involving a platinum octaethyl-porphyrin (PtOEP) as a sensitizer and tetraphenyl-pyrene (TPPy) as an emitter, has been investigated in homogeneous solutions of toluene, bromobenzene and anisole, and oil-in-water microemulsions of the TX-100 surfactant, where toluene constitutes the non-polar phase. In homogeneous solutions, the highest up-conversion quantum yield (of the order of 20%) has been achieved in toluene, being the solvent that has the lowest viscosity among those explored. The up-conversion emission from the PtOEP-TPPy pair has been then investigated in a toluene based oil-in-water microemulsion at three different concentrations of the solutes, showing quantum yields up to the order of 1%, under the same irradiation conditions, but different deoxygenating procedures. The results herein reported might represent a good starting point for a future investigation in microheterogeneous systems. An optimization of the microemulsion composition, in terms of surfactant, co-surfactant and toluene concentrations, could allow us to increase the sensitizer and emitter concentrations and set up the best operative conditions to obtain even higher up-conversion efficiencies.

  1. Effect of cold water and inverse lighting on growth performance of broiler chickens under extreme heat stress.

    Science.gov (United States)

    Park, Sang-oh; Park, Byung-sung; Hwangbo, Jong

    2015-07-01

    The present study was carried out to investigate the effect of provision of extreme heat stress diet (EHD), inverse lighting, cold water on growth performance of broiler chickens exposed to extreme heat stress. The chickens were divided into four treatment groups, (T1, T2, T3, T4) as given below: Ti (EHD 1, 10:00-19:00 dark, 19:00-10:00 light, cool water 9 degrees C); T2 (EHD 2, 10:00-19:00 dark, 19:00-10:00 light, cool water 9 degrees C); T3 (EHD 1, 09:00-18:00 dark, 18:00-09:00 light, cool water 141C); T4 (EHD 2, 09:00-18:00 dark, 18:00-09:00 light, cool water 14 degrees C. EHD 1 contained soybean oil, molasses, methionine and lysine; EHD 2 contained the same ingredients as EHD 1 with addition of vitamin C. Groups T1 and T2 were given cooler water than the othertwo groups, and displayed higher body weight increase and diet intake as compared to T3 and T4 (pstress diet, inverse lighting (10:00-19:00 dark, 19:00-10:00 light) with cold water at 9 degrees C under extreme heat stress could enhance growth performance of broiler chickens.

  2. Visible-light-responsive photocatalysts toward water oxidation based on NiTi-layered double hydroxide/reduced graphene oxide composite materials.

    Science.gov (United States)

    Li, Bei; Zhao, Yufei; Zhang, Shitong; Gao, Wa; Wei, Min

    2013-10-23

    A visible-light responsive photocatalyst was fabricated by anchoring NiTi-layered double hydroxide (NiTi-LDH) nanosheets to the surface of reduced graphene oxide sheets (RGO) via an in situ growth method; the resulting NiTi-LDH/RGO composite displays excellent photocatalytic activity toward water splitting into oxygen with a rate of 1.968 mmol g(-1) h(-1) and a quantum efficiency as high as 61.2% at 500 nm, which is among the most effective visible-light photocatalysts. XRD patterns and SEM images indicate that the NiTi-LDH nanosheets (diameter: 100-200 nm) are highly dispersed on the surface of RGO. UV-vis absorption spectroscopy exhibits that the introduction of RGO enhances the visible-light absorption range of photocatalysts, which is further verified by the largely decreased band gap (∼1.78 eV) studied by cyclic voltammetry measurements. Moreover, photoluminescence (PL) measurements indicate a more efficient separation of electron-hole pairs; electron spin resonance (ESR) and Raman scattering spectroscopy confirm the electrons transfer from NiTi-LDH nanosheets to RGO, accounting for the largely enhanced carrier mobility and the resulting photocatalytic activity in comparison with pristine NiTi-LDH material. Therefore, this work demonstrates a facile approach for the fabrication of visible-light responsive NiTi-LDH/RGO composite photocatalysts, which can be used as a promising candidate in solar energy conversion and environmental science.

  3. Stability analysis of supercritical-pressure light water-cooled reactor in constant pressure operation

    Energy Technology Data Exchange (ETDEWEB)

    Suhwan, JI; Shirahama, H.; Koshizuka, S.; Oka, Y. [Tokyo Univ., Tokai, Ibaraki (Japan). Nuclear Engineering Research Lab.

    2001-07-01

    The purpose of this study is to evaluate the thermal-hydraulic and the thermal-nuclear coupled stabilities of a supercritical pressure light water-cooled reactor. A stability analysis code at supercritical pressure is developed. Using this code, stabilities of full and partial-power reactor operating at supercritical pressure are investigated by the frequency-domain analysis. Two types of SCRs are analyzed; a supercritical light water reactor (SCLWR) and a supercritical water-cooled fast reactor (SCFR). The same stability criteria as Boiling Water Reactor are applied. The thermal-hydraulic stability of SCLWR and SCFR satisfies the criteria with a reasonable orifice loss coefficient. The decay ratio of the thermal-nuclear coupled stability in SCFR is almost zero because of a small coolant density coefficient of the fast reactor. The evaluated decay ratio of the thermal-nuclear coupled stability is 3,41 {approx} 10{sup -V} at 100% power in SCFR and 0,028 at 100% power in SCLWR. The sensitivity is investigated. It is found that the thermal-hydraulic stability is sensitive to the mass flow rate strongly and the thermal-nuclear coupled stability to the coolant density coefficient. The bottom power peak distribution makes the thermal-nuclear stability worse and the thermal-nuclear stability better. (author)

  4. Infrared light-induced protein crystallization. Structuring of protein interfacial water and periodic self-assembly

    Science.gov (United States)

    Kowacz, Magdalena; Marchel, Mateusz; Juknaité, Lina; Esperança, José M. S. S.; Romão, Maria João; Carvalho, Ana Luísa; Rebelo, Luís Paulo N.

    2017-01-01

    We show that a physical trigger, a non-ionizing infrared (IR) radiation at wavelengths strongly absorbed by liquid water, can be used to induce and kinetically control protein (periodic) self-assembly in solution. This phenomenon is explained by considering the effect of IR light on the structuring of protein interfacial water. Our results indicate that the IR radiation can promote enhanced mutual correlations of water molecules in the protein hydration shell. We report on the radiation-induced increase in both the strength and cooperativeness of H-bonds. The presence of a structured dipolar hydration layer can lead to attractive interactions between like-charged biomacromolecules in solution (and crystal nucleation events). Furthermore, our study suggests that enveloping the protein within a layer of structured solvent (an effect enhanced by IR light) can prevent the protein non-specific aggregation favoring periodic self-assembly. Recognizing the ability to affect protein-water interactions by means of IR radiation may have important implications for biological and bio-inspired systems.

  5. Direct conversion of cellulose using carbon monoxide and water on a Pt-Mo2C/C catalyst

    KAUST Repository

    Li, Jing

    2014-01-01

    CO and H2O were employed as the hydrogen source for cellulose conversion to polyols. Pt-Mo2C/C tandem catalyst with the Pt-Mo 2C domain responsible for H2 and/or H production and the Pt-C domain for cellulose conversion was fabricated. Considerable polyols were obtained over this tandem Pt-Mo2C/C catalyst. This journal is © 2014 The Royal Society of Chemistry.

  6. Platinum(II)-porphyrin as a sensitizer for visible-light driven water oxidation in neutral phosphate buffer

    NARCIS (Netherlands)

    Chen, H.C.; Hetterscheid, D.G.H.; Williams, R.M.; van der Vlugt, J.I.; Reek, J.N.H.; Brouwer, A.M.

    2015-01-01

    A water-soluble Pt(II)-porphyrin with a high potential for one-electron oxidation (similar to 1.42 V vs. NHE) proves very suitable for visible-light driven water oxidation in neutral phosphate buffer solution in combination with a variety of water oxidation catalysts (WOCs) . Two homogeneous WOCs (i

  7. Structured luminescence conversion layer

    Science.gov (United States)

    Berben, Dirk; Antoniadis, Homer; Jermann, Frank; Krummacher, Benjamin Claus; Von Malm, Norwin; Zachau, Martin

    2012-12-11

    An apparatus device such as a light source is disclosed which has an OLED device and a structured luminescence conversion layer deposited on the substrate or transparent electrode of said OLED device and on the exterior of said OLED device. The structured luminescence conversion layer contains regions such as color-changing and non-color-changing regions with particular shapes arranged in a particular pattern.

  8. Conversion disorder

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/000954.htm Conversion disorder To use the sharing features on this page, please enable JavaScript. Conversion disorder is a mental condition in which a person ...

  9. Intrinsic oxidation kinetics of sulfite catalyzed by peracetic acid under different water quality and light conditions

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Oxidation of sulfite is an important process in wet flue gas desulfurization.Using highly purified water or distilled water as a reaction medium and a transparent or an opaque intermittent reaction apparatus,the intrinsic oxidation kinetics of sulfite catalyzed by peracetic acid was investigated under four dif-ferent conditions.The reaction order of the reagents and the activation energy were obtained.The re-sults indicate that water quality and light have no obvious effects on the reaction order and activation energy,but have an influence on the reaction rate constant.The mechanism of the intrinsic reaction is proposed.The results derived with this mechanism are in good agreement with the experimental re-sults.

  10. Intrinsic oxidation kinetics of sulfite catalyzed by peracetic acid under different water quality and light conditions

    Institute of Scientific and Technical Information of China (English)

    WANG LiDong; ZHAO Yi; LI QiangWei; CHEN ZhouYan; LIU SongTao; MA YongLiang; HAO JiMing

    2009-01-01

    Oxidation of sulfite is an important process in wet flue gas desulfurization. Using highly purified water or distilled water as a reaction medium and a transparent or an opaque intermittent reaction apparatus, the intrinsic oxidation kinetics of sulfite catalyzed by peracetic acid was investigated under four dif-ferent conditions. The reaction order of the reagents and the activation energy were obtained. The re-sults indicate that water quality and light have no obvious effects on the reaction order and activation energy, but have an influence on the reaction rate constant. The mechanism of the intrinsic reaction is proposed. The results derived with this mechanism are in good agreement with the experimental re-sults.

  11. Proposed Photosynthesis Method for Producing Hydrogen from Dissociated Water Molecules Using Incident Near-Infrared Light

    Science.gov (United States)

    Li, Xingxing; Li, Zhenyu; Yang, Jinlong

    2014-01-01

    Highly efficient solar energy utilization is very desirable in photocatalytic water splitting. However, until now, the infrared part of the solar spectrum, which constitutes almost half of the solar energy, has not been used, resulting in significant loss in the efficiency of solar energy utilization. Here, we propose a new mechanism for water splitting in which near-infrared light can be used to produce hydrogen. This ability is a result of the unique electronic structure of the photocatalyst, in which the valence band and conduction band are distributed on two opposite surfaces with a large electrostatic potential difference produced by the intrinsic dipole of the photocatalyst. This surface potential difference, acting as an auxiliary booster for photoexcited electrons, can effectively reduce the photocatalyst's band gap required for water splitting in the infrared region. Our electronic structure and optical property calculations on a surface-functionalized hexagonal boron-nitride bilayer confirm the existence of such photocatalysts and verify the reaction mechanism.

  12. Light induced production of hydrogen from water by catalysis with ruthenium melanoidins

    Energy Technology Data Exchange (ETDEWEB)

    Serban, Andrei; Nissenbaum, Arie [Weizmann Inst. of Science, Rehovot (Israel)

    2000-08-01

    A ruthenium containing melanoidin (a condensation product of amino acids and carbohydrates) was found to photocatalyze hydrogen production from water under light irradiation with {lambda} < 320 nm, in the presence of EDTA as an electron donor and methyl viologen as an electron relay. Tracer experiments indicate that the hydrogen evolved originates from water. The bimolecular quenching constant for the quenching of melanoidin fluorescence by methyl viologen is large (k{sub {theta}} {approx} 10{sup 9}) suggesting a diffusion controlled reaction rate. The small Stern-Volmer constant(K{sub SV} {approx} 10) indicates an inefficient electron transfer between the excited melanoidin and the methyl viologen, perhaps due to the difficulties in removing O{sub 2} from the polymer. The Ru-melanoidin photocatalyst is stable under prolonged irradiation times and, due to its insolubility in water, is suitable for recycling. (Author)

  13. Effects of the light--dark cycle on a water tank social interaction test in mice.

    Science.gov (United States)

    Nejdi, A; Guastavino, J M; Lalonde, R

    1996-01-01

    Mice were exposed to a water tank interaction test in which food could be obtained either by wading in the water or by attacking littermates. A tank with progressively rising water levels caused mice in groups of four to differentiate into those willing to wade (carrier mice) from those unwilling to wade (noncarrier mice). Noncarrier mice could only obtain food by stealing it from carrier mice or from other noncarrier mice. It was found that mice during the dark period of the light--dark cycle were more willing to wade in the search for food rather than attempt to steal food from other mice. Because mice are generally more active during the dark period, this result suggests that higher activity levels increase the willingness to share the work load, a form of altruism, rather than promote parasitic behavior and aggression.

  14. DIMENSIONAL STABILITY AND WATER REPELLENT EFFICIENCY MEASUREMENT OF CHEMICALLY MODIFIED TROPICAL LIGHT HARDWOOD

    Directory of Open Access Journals (Sweden)

    Md Saiful Islam,

    2012-01-01

    Full Text Available Chemical modification is an often-followed route to improve physical and mechanical properties of solid wood materials. In this study five kinds of tropical light hardwoods species, namely jelutong (Dyera costulata, terbulan (Endospermum diadenum, batai (Paraserianthes moluccana, rubberwood (Hevea brasiliensis, and pulai (Alstonia pneumatophora, were chemically modified with benzene diazonium salt to improve their dimensional stability and water repellent efficiency. The dimensional stability of treated samples in terms of volumetric swelling coefficient (S and anti-swelling-efficiency (ASE were found to improve with treatment. The water repellent efficiency (WRE values also seemed to improve considerably with treatment of wood samples. Furthermore, treated wood samples had lower water and moisture absorption compared to that of untreated ones.

  15. Recent performance experience with US light water reactor self-actuating safety and relief valves

    Energy Technology Data Exchange (ETDEWEB)

    Hammer, C.G.

    1996-12-01

    Over the past several years, there have been a number of operating reactor events involving performance of primary and secondary safety and relief valves in U.S. Light Water Reactors. There are several different types of safety and relief valves installed for overpressure protection of various safety systems throughout a typical nuclear power plant. The following discussion is limited to those valves in the reactor coolant systems (RCS) and main steam systems of pressurized water reactors (PWR) and in the RCS of boiling water reactors (BWR), all of which are self-actuating having a setpoint controlled by a spring-loaded disk acting against system fluid pressure. The following discussion relates some of the significant recent experience involving operating reactor events or various testing data. Some of the more unusual and interesting operating events or test data involving some of these designs are included, in addition to some involving a number of similar events and those which have generic applicability.

  16. Novel Transparent Phosphor Conversion Matrix with High Thermal Conductivity for Next Generation Phosphor-Converted LED-based Solid State Lighting

    Energy Technology Data Exchange (ETDEWEB)

    Bockstaller, Michael [Carnegie Mellon Univ., Pittsburgh, PA (United States)

    2017-02-06

    The low thermal conductivity of state-of-the-art polymer encapsulants (k ~ 0.15 Wm-1K-1) limits the efficiency and power density of current phosphor conversion light emitting diodes (pc-LEDs). The technical objective of this project was to demonstrate synthesis and processing schemes for the fabrication of polymer hybrid encapsulants with a thermal conductivity exceeding k = 0.4 Wm-1K-1 for LED applications. The ‘hybrid polymer’ approach encompasses the dispersion of high thermal conductivity particle fillers (zinc oxide, ZnO as well as the alpha-polymorph of alumina, Al2O3) within a polysiloxane matrix (poly(dimethylsiloxane), PDMS as well as poly(phenyl methyl siloxane), PPMS) to increase the thermal conductivity while maintaining optical transparency and photothermal stability at levels consistent with LED applications. To accomplish this goal, a novel synthesis method for the fabrication of nanosized ZnO particles was developed and a novel surface chemistry was established to modify the surface of zinc oxide particle fillers and thus to enable their dispersion in poly(dimethyl siloxane) (PDMS) matrix polymers. Molecular dynamics and Mie simulations were used to optimize ligand structure and to enable the concurrent mixing of particles in PDMS/PPMS embedding media while also minimizing the thermal boundary resistance as well as optical scattering of particle fillers. Using this approach the synthesis of PDMS/ZnO hybrid encapsulants exhibiting a thermal conductivity of 0.64 Wm-1K-1 and optical transparency > 0.7 mm-1 was demonstrated. A forming process based on micromolding was developed to demonstrate the forming of particle filled PDMS into film and lens shapes. Photothermal stability testing revealed stability of the materials for approximately 4000 min when exposed to blue light LED (450 nm, 30 W/cm2). One postgraduate and seven graduate students were supported by the project. The research performed within this project led to fifteen publications in peer

  17. Comparison of dye photodegradation and its coupling with light-to-electricity conversion over TiO(2) and ZnO.

    Science.gov (United States)

    Li, Yuanzhi; Xie, Wei; Hu, Xuelei; Shen, Guofang; Zhou, Xi; Xiang, Ye; Zhao, Xiujian; Fang, Pengfei

    2010-01-05

    Through comparing the photocatalytic performance of microscale ZnO, nano ZnO, and Degussa P25 titania (P25), it was found that the microscale ZnO exhibited 2.6-35.7 times higher photocatalytic activity for the photodegradation of various dye pollutants than P25 under both UV-visible and visible irradiation and showed much better photostability than the nano ZnO. The photocatalysts were characterized with XRD, Raman, BET, DRUV-vis, adsorption of dye, photoelectrochemical measurement, and PL. The much higher photocataltyic activity of the microscale ZnO than P25 under UV-visible irradiation is attributed to the higher efficiency of generation, mobility, and separation of photoinduced electrons and holes. The much higher visible photocataltyic activity of the microscale ZnO than P25 is due to the higher photosensitization efficiency of electron transfer from an excited dye to the conduction band of the microscale ZnO than that of P25. The much better photostability of the microscale ZnO than the nano ZnO is due to its better crystallinity and lower defects. The photostability of the microscale ZnO is greatly improved by the surface modification of ZnO with a small amount of TiO(2). On the basis of the excellent photocatalytic performance of the microscale ZnO and TiO(2)-modified ZnO, a novel device of coupling photodegradation with light-to-electricity conversion was developed, which is a promising candidate for the photocatalytic removal of dye pollutants and a renewable energy source.

  18. Light absorption and partitioning in Arctic Ocean surface waters: impact of multiyear ice melting

    Directory of Open Access Journals (Sweden)

    S. Bélanger

    2013-10-01

    Full Text Available Ice melting in the Arctic Ocean exposes the surface water to more radiative energy with poorly understood effects on photo-biogeochemical processes and heat deposition in the upper ocean. In August 2009, we documented the vertical variability of light absorbing components at 37 stations located in the southeastern Beaufort Sea including both Mackenzie River-influenced waters and polar mixed layer waters. We found that melting multiyear ice released significant amount of non-algal particulates (NAP near the sea surface relative to subsurface waters. NAP absorption coefficients at 440 nm (aNAP(440 immediately below the sea surface were on average 3-fold (up to 10-fold higher compared to subsurface values measured at 2–3 m depth. The impact of this unusual feature on the light transmission and remote sensing reflectance (Rrs was further examined using a radiative transfer model. A 10-fold particle enrichment homogeneously distributed in the first meter of the water column slightly reduced photosynthetically available and usable radiation (PAR and PUR by ∼6 and ∼8%, respectively, relative to a fully homogenous water column with low particle concentration. In terms of Rrs, the particle enrichment significantly flattered the spectrum by reducing the Rrs by up to 20% in the blue-green spectral region (400–550 nm. These results highlight the impact of meltwater on the concentration of particles at sea surface, and the need for considering non-uniform vertical distribution of particles in such systems when interpreting remotely sensed ocean color. Spectral slope of aNAP spectra calculated in the UV (ultraviolet domain decreased with depth suggesting that this parameter is sensitive to detritus composition and/or diagenesis state (e.g., POM (particulate organic matter photobleaching.

  19. Dynamics of biological water: insights from molecular modeling of light scattering in aqueous trehalose solutions.

    Science.gov (United States)

    Lupi, Laura; Comez, Lucia; Paolantoni, Marco; Fioretto, Daniele; Ladanyi, Branka M

    2012-06-28

    Extended depolarized light scattering (EDLS) measurements have been recently employed to investigate the dynamics of water solvating biological molecules, giving evidence of the presence of two different dynamical regimes among water molecules. An interpretation of EDLS has been proposed that provides an independent estimate of the retardation factor of slowdown with respect to fast water molecules and of the number of solvent molecules affected by this slowing down. Nevertheless this measure is an inherently complex one, due to the collective nature of the physical property probed. In the present work a molecular dynamics (MD) approach has been used to more deeply understand experimental results. Time correlation functions of the collective polarizability anisotropy have been calculated for the prototype disaccharide trehalose in aqueous solutions as a function of concentration. The unique capability of MD to disentangle the contributions to the dynamics arising from solute, solvent, and cross terms between the two allowed us to check the reliability of an interpretation that assumes a spectral separation of water and sugar dynamics, as well as to highlight the very presence of two distinct relaxation processes in water. The two processes have been attributed to the dynamics of bulk and hydration water, respectively. A retardation factor of ~5 and concentration dependent hydration numbers have been observed, in good agreement with experimental results [Paolantoni, M.; et al. J. Phys. Chem. B 2009, 113, 7874-7878].

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

    Science.gov (United States)

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

    2010-01-01

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

  1. Modeling the underwater light field fluctuations in coastal oceanic waters: Validation with experimental data

    Science.gov (United States)

    Sundarabalan, Balasubramanian; Shanmugam, Palanisamy; Ahn, Yu-Hwan

    2016-03-01

    Modeling of the wave-induced underwater light fluctuations at near-surface depths in coastal oceanic waters is challenging because of the surface roughness and strong anisotropic effects of the light field. In the present work, a simple and computationally efficient radiative transfer model is used for the wind-driven sea surface for simulating underwater light fields such as downwelling irradiance ( E d ), upwelling irradiance ( E u ), and upwelling radiance ( L u ) in a spatial domain. It is an extension of our previous work that essentially combines the air-sea interface of the wind-driven sea surface with transmittance and reflectance along with the diffuse and direct components of the homogenous and inhomogeneous water column. The present model simulates underwater light fields for any possible values of absorption and backscattering coefficients. To assess the performance of the model, the E d , E u , and L u profiles predicted by the model are compared with experimental data from relatively clear and turbid coastal waters. Statistical results show significantly low mean relative differences regardless of the wavelength. Comparison of the simulated and in-situ time series data measured over rough sea surfaces demonstrates that model-observation agreement is good for the present model. The Hydrolight model when implemented with the modified bottom reflectance and phase function provides significantly better results than the original Hydrolight model without consideration of the bottom slope and vertically varying phase function. However, these results are non-spatial and have errors fluctuating at different wavelengths. To further demonstrate the efficiency of the present model, spatial distribution patterns of the underwater light fields are simulated based on the measured data from a coastal station for different solar zenith angles (under sunny condition). Simulated wave-induced fluctuations of the underwater lights fields show a good consistency with in

  2. Degradation of methyl and ethyl mercury by singlet oxygen generated from sea water exposed to sunlight or ultraviolet light.

    Science.gov (United States)

    Suda, I; Suda, M; Hirayama, K

    1993-01-01

    Photodegradation of methyl mercury (MeHg) and ethyl Hg (EtHg) in sea water was studied by sunlight or ultraviolet (UV) light exposure, and by determining inorganic Hg produced by degradation. Sea water containing 1 microM MeHg or EtHg was exposed to sunlight or UV light. N-Acetyl-L-cysteine was added to the solution for preventing Hg loss during the light exposure. MeHg and EtHg in sea water were degraded by sunlight (> 280 nm), UV light A (320-400 nm) and UV light B (280-320 nm), though the amounts of inorganic Hg produced from MeHg were 1/6th to 1/12th those from EtHg. Inorganic Hg production was greater with increasing concentration of sea water. Degradation of MeHg and EtHg by the UV light A exposure was inhibited by singlet oxygen (1O2) trappers such as NaN3, 1,4-diazabicyclo[2,2,2]octane, histidine, methionine and 2,5-dimethylfuran. On the other hand, inhibitors or scavengers of superoxide anion, hydrogen peroxide or hydroxyl radical did not inhibit the photodegradation of alkyl Hg. These results suggested that 1O2 generated from sea water exposed to sunlight, UV light A or UV light B was the reactive oxygen species mainly responsible for the degradation of MeHg and EtHg.

  3. Photocatalytic conversion of methane to methanol

    Energy Technology Data Exchange (ETDEWEB)

    Taylor, C.E.; Noceti, R.P.; D`Este, J.R. [Pittsburgh Energy Technology Center, PA (United States)

    1995-12-31

    A long-term goal of our research group is the exploration of novel pathways for the direct oxidation of methane to liquid fuels, chemicals, and intermediates. The use of three relatively abundant and inexpensive reactants, light, water, and methane, to produce methanol is attractive. The products of reaction, methanol and hydrogen, are both commercially desirable, methanol being used as is or converted to a variety of other chemicals, and the hydrogen could be utilized in petroleum and/or chemical manufacturing. Methane is produced as a by-product of coal gasification. Depending upon reactor design and operating conditions, up to 18% of total gasifier product may be methane. In addition, there are vast proven reserves of geologic methane in the world. Unfortunately, a large fraction of these reserves are in regions where there is little local demand for methane and it is not economically feasible to transport it to a market. There is a global research effort under way in academia, industry, and government to find methods to convert methane to useful, more readily transportable and storable materials. Methanol, the initial product of methane oxidation, is a desirable product of conversion because it retains much of the original energy of the methane while satisfying transportation and storage requirements. Investigation of direct conversion of methane to transportation fuels has been an ongoing effort at PETC for over 10 years. One of the current areas of research is the conversion of methane to methanol, under mild conditions, using light, water, and a semiconductor photocatalyst. The use of three relatively abundant and inexpensive reactants, light, water, and methane, to produce methanol, is attractive. Research in the laboratory is directed toward applying the techniques developed for the photocatalytic splitting of the water and the photochemical conversion of methane.

  4. Water-light interaction: A novel pathway for multi hallmark therapy in cancer

    Directory of Open Access Journals (Sweden)

    Luis Santana-Blank

    2014-02-01

    Full Text Available Laser photobiomodulation (LPBM has been proposed as a multi-target (multi-hallmark therapy for cancer and other complex diseases based on an approach that aims to substitute and/or complement metabolic energy pathways through oxygen-dependent (e.g., cytochrome c oxidase (CcO and/or oxygen-independent (e.g., light-water interactions (e.g., F0-F1 motors mechanisms with critical signaling pathways in primarily aqueous media. Cellular and molecular bases for water-mediated, long-range, energy supplementation aimed at inducing and modulating physiologically reparative processes, including apoptosis, have been previously presented through a mechanism termed Photo Infrared Pulsed Biomodulation (PIPBM. Water’s role as an oscillator in LPBM has also been documented. These ideas were recently complemented by integrating the role of the quasi-crystalline exclusion zone (EZ described by Pollack as the fourth phase of water. This is retrospective analysis of experimental and clinical data using an infrared pulsed laser device (IPLD. It found photo-induced effects over the water dynamics of burned rat tissue monitored by 1H-NMR transverse relaxation times (1/T2, indicating significantly greater structuring of water. In addition, a microdensitometry study of T2 weighted tumor heterogeneities from a phase I clinical trial of the IPLD in patients with advanced neoplasias and an algorithm for tumor characterization indicated significantly increased structuring of water, possibly proving a photobiomodulation effect over the EZ associated with histologically-confirmed selective photo-induced tumor cell death. To the best of our knowledge, this is the first clinical demonstration of light-induced effects over the EZ. It supports our premise that LPBM can increase potential energy in the EZ, which then acts as a rechargeable electrolytic bio-battery for the external selective supplementation of the energy demand required for cellular work, signaling pathways and

  5. Surface Plasmon-Assisted Solar Energy Conversion.

    Science.gov (United States)

    Dodekatos, Georgios; Schünemann, Stefan; Tüysüz, Harun

    2016-01-01

    The utilization of localized surface plasmon resonance (LSPR) from plasmonic noble metals in combination with semiconductors promises great improvements for visible light-driven photocatalysis, in particular for energy conversion. This review summarizes the basic principles of plasmonic photocatalysis, giving a comprehensive overview about the proposed mechanisms for enhancing the performance of photocatalytically active semiconductors with plasmonic devices and their applications for surface plasmon-assisted solar energy conversion. The main focus is on gold and, to a lesser extent, silver nanoparticles in combination with titania as semiconductor and their usage as active plasmonic photocatalysts. Recent advances in water splitting, hydrogen generation with sacrificial organic compounds, and CO2 reduction to hydrocarbons for solar fuel production are highlighted. Finally, further improvements for plasmonic photocatalysts, regarding performance, stability, and economic feasibility, are discussed for surface plasmon-assisted solar energy conversion.

  6. White light up-conversion in transparent sol-gel derived glass-ceramics containing Yb{sup 3+}-Er{sup 3+}-Tm{sup 3+} triply-doped YF{sub 3} nanocrystals

    Energy Technology Data Exchange (ETDEWEB)

    Santana-Alonso, A. [Departamento Fisica Basica, Universidad de La Laguna, 38206, La Laguna, Tenerife (Spain); Mendez-Ramos, J. [Departamento Fisica Fundamental y Experimental, Electronica y Sistemas, Universidad de La Laguna, 38206, La Laguna, Tenerife (Spain); Yanes, A.C., E-mail: ayanesh@ull.es [Departamento Fisica Basica, Universidad de La Laguna, 38206, La Laguna, Tenerife (Spain); Castillo, J. del [Departamento Fisica Basica, Universidad de La Laguna, 38206, La Laguna, Tenerife (Spain); Rodriguez, V.D. [Departamento Fisica Fundamental y Experimental, Electronica y Sistemas, Universidad de La Laguna, 38206, La Laguna, Tenerife (Spain)

    2010-11-01

    Transparent glass-ceramics containing YF{sub 3} nanocrystals triply-doped with Yb{sup 3+}-Er{sup 3+}-Tm{sup 3+} ions have been successfully obtained under adequate thermal treatment of precursor sol-gel glasses for the first time to our knowledge. X-ray diffraction and high resolution transmission electron microscopy analysis pointed out the precipitation of YF{sub 3} nanocrystals. Up-conversion luminescence features confirm the effective partition of luminescent ions into precipitated nanocrystals. Corresponding energy transfer up-conversion mechanisms and the dependence of the overall emitting colour have been analyzed as a function of doping ions, with varying concentration. In particular, very bright and efficient up-conversion emission, almost matching the standard equal energy white light illumination point of the standard chromaticity diagram, has been achieved showing up as promising candidate material for potential applications in photonic integrated devices and infrared tuneable phosphors.

  7. Light Water Reactor Sustainability Program Status of Silicon Carbide Joining Technology Development

    Energy Technology Data Exchange (ETDEWEB)

    Shannon M. Bragg-Sitton

    2013-09-01

    Advanced, accident tolerant nuclear fuel systems are currently being investigated for potential application in currently operating light water reactors (LWR) or in reactors that have attained design certification. Evaluation of potential options for accident tolerant nuclear fuel systems point to the potential benefits of silicon carbide (SiC) relative to Zr-based alloys, including increased corrosion resistance, reduced oxidation and heat of oxidation, and reduced hydrogen generation under steam attack (off-normal conditions). If demonstrated to be applicable in the intended LWR environment, SiC could be used in nuclear fuel cladding or other in-core structural components. Achieving a SiC-SiC joint that resists corrosion with hot, flowing water, is stable under irradiation and retains hermeticity is a significant challenge. This report summarizes the current status of SiC-SiC joint development work supported by the Department of Energy Light Water Reactor Sustainability Program. Significant progress has been made toward SiC-SiC joint development for nuclear service, but additional development and testing work (including irradiation testing) is still required to present a candidate joint for use in nuclear fuel cladding.

  8. Light refraction by water as a rationale for the Poggendorff illusion

    CERN Document Server

    Bozhevolnyi, Sergey I

    2015-01-01

    The Poggendorff illusion in its classical form of parallel lines interrupting a transversal is viewed from the perspective of being related to the everyday experience of observing the light refraction in water. It is argued that, if one considers a transversal to be a light ray in air and the parallel lines to form an occluding strip of a medium with the refractive index being between that of air and water, then one should be able to account, both qualitatively and quantitatively, for most of the features associated with the Poggendorff illusion. Statistical treatment of the visual experiments conducted with 7 participants, each analysing 50 configurations having different intercepting angles and strip widths, resulted in the effective refractive index of the occluding strip N = 1.13 +/- 0.15, which is sufficiently close to the average (between that of water and air) refractive index of ~ 1.17. It is further argued that the same mechanism can also be employed to account for many variants of the Poggendorff il...

  9. Laser-light backscattering response to water content and proteolysis in dry-cured ham

    DEFF Research Database (Denmark)

    Fulladosa, E.; Rubio-Celorio, M.; Skytte, Jacob Lercke

    2017-01-01

    Laser backscattering imaging (LBI) is a low-cost technology proposed to determine non-invasively composition and microstructural characteristics of agro food and dairy products. The aim of this work was to define the effect of different acquisition conditions (wavelength, object distance and angle...... of laser incidence) and to analyse the laser-light backscattering changes caused by additional hot air drying and proteolysis of dry-cured ham slices. The feasibility of the technology to determine water content and proteolysis (which is related to textural characteristics) of commercial sliced dry......-cured ham was also evaluated. Results showed that a red laser (635 nm) is more convenient than a green laser (532 nm) to analyse dry-cured ham but no preferable angle or object distance to evaluate dryness or proteolysis was found. Nevertheless, light scattering parameters were modified depending...

  10. Light saturation curves show competence of the water splitting complex in inactive Photosystem II reaction centers.

    Science.gov (United States)

    Nedbal, L; Gibas, C; Whitmarsh, J

    1991-12-01

    Photosystem II complexes of higher plants are structurally and functionally heterogeneous. While the only clearly defined structural difference is that Photosystem II reaction centers are served by two distinct antenna sizes, several types of functional heterogeneity have been demonstrated. Among these is the observation that in dark-adapted leaves of spinach and pea, over 30% of the Photosystem II reaction centers are unable to reduce plastoquinone to plastoquinol at physiologically meaningful rates. Several lines of evidence show that the impaired reaction centers are effectively inactive, because the rate of oxidation of the primary quinone acceptor, QA, is 1000 times slower than in normally active reaction centers. However, there are conflicting opinions and data over whether inactive Photosystem II complexes are capable of oxidizing water in the presence of certain artificial electron acceptors. In the present study we investigated whether inactive Photosystem II complexes have a functional water oxidizing system in spinach thylakoid membranes by measuring the flash yield of water oxidation products as a function of flash intensity. At low flash energies (less that 10% saturation), selected to minimize double turnovers of reaction centers, we found that in the presence of the artificial quinone acceptor, dichlorobenzoquinone (DCBQ), the yield of proton release was enhanced 20±2% over that observed in the presence of dimethylbenzoquinone (DMBQ). We argue that the extra proton release is from the normally inactive Photosystem II reaction centers that have been activated in the presence of DCBQ, demonstrating their capacity to oxidize water in repetitive flashes, as concluded by Graan and Ort (Biochim Biophys Acta (1986) 852: 320-330). The light saturation curves indicate that the effective antenna size of inactive reaction centers is 55±12% the size of active Photosystem II centers. Comparison of the light saturation dependence of steady state oxygen evolution

  11. UV Light Inactivation of Human and Plant Pathogens in Unfiltered Surface Irrigation Water

    Science.gov (United States)

    Jones, Lisa A.; Worobo, Randy W.

    2014-01-01

    Fruit and vegetable growers continually battle plant diseases and food safety concerns. Surface water is commonly used in the production of fruits and vegetables and can harbor both human- and plant-pathogenic microorganisms that can contaminate crops when used for irrigation or other agricultural purposes. Treatment methods for surface water are currently limited, and there is a need for suitable treatment options. A liquid-processing unit that uses UV light for the decontamination of turbid juices was analyzed for its efficacy in the treatment of surface waters contaminated with bacterial or oomycete pathogens, i.e., Escherichia coli, Salmonella enterica, Listeria monocytogenes, Clavibacter michiganensis subsp. michiganensis, Pseudomonas syringae pv. tomato, and Phytophthora capsici. Five-strain cocktails of each pathogen, containing approximately 108 or 109 CFU/liter for bacteria or 104 or 105 zoospores/liter for Ph. capsici, were inoculated into aliquots of two turbid surface water irrigation sources and processed with the UV unit. Pathogens were enumerated before and after treatment. In general, as the turbidity of the water source increased, the effectiveness of the UV treatment decreased, but in all cases, 99.9% or higher inactivation was achieved. Log reductions ranged from 10.0 to 6.1 and from 5.0 to 4.2 for bacterial pathogens and Ph. capsici, respectively. PMID:24242253

  12. Environmentally assisted cracking in light water reactors. Semiannual progress report, January 1996--June 1996

    Energy Technology Data Exchange (ETDEWEB)

    Chopra, O.K.; Chung, H.M.; Gruber, E.E. [and others

    1997-05-01

    This report summarizes work performed by Argonne National Laboratory on fatigue and environmentally assisted cracking (EAC) in light water reactors from January 1996 to June 1996. Topics that have been investigated include (a) fatigue of carbon, low-alloy, and austenitic stainless steels (SSs) used in reactor piping and pressure vessels, (b) irradiation-assisted stress corrosion cracking of Type 304 SS, and (c) EAC of Alloys 600 and 690. Fatigue tests were conducted on ferritic and austenitic SSs in water that contained various concentrations of dissolved oxygen (DO) to determine whether a slow strain rate applied during various portions of a tensile-loading cycle are equally effective in decreasing fatigue life. Slow-strain-rate-tensile tests were conducted in simulated boiling water reactor (BWR) water at 288{degrees}C on SS specimens irradiated to a low fluence in the Halden reactor and the results were compared with similar data from a control-blade sheath and neutron-absorber tubes irradiated in BWRs to the same fluence level. Crack-growth-rate tests were conducted on compact-tension specimens from several heats of Alloys 600 and 690 in air and high-purity, low-DO water. 83 refs., 60 figs., 14 tabs.

  13. Environmentally assisted cracking in light water reactors. Semiannual report, April 1994--September 1994, Volume 19

    Energy Technology Data Exchange (ETDEWEB)

    Chopra, O.K.; Chung, H.M.; Gavenda, D.J. [and others

    1995-09-01

    This report summarizes work performed by Argonne National Laboratory (ANL) on fatigue and environmentally assisted cracking (EAC) in light water reactors from April to September 1994. Topics that have been investigated include (a) fatigue of carbon and low-alloy steel used in piping and reactor pressure vessels, (b) EAC of austenitic stainless steels (SSs) and Alloy 600, and (c) irradiation-assisted stress corrosion cracking (IASCC) of Type 304 SS. Fatigue tests have been conducted on A106-Gr B and A533-Gr B steels in oxygenated water to determine whether a slow strain rate applied during different portions of a tensile-loading cycle are equally effective in decreasing fatigue life. Crack growth data were obtained on fracture-mechanics specimens of SSs and Alloy 600 to investigate EAC in simulated boiling water reactor (BWR) and pressurized water reactor environments at 289{degrees}C. The data were compared with predictions from crack growth correlations developed at ANL for SSs in water and from rates in air from Section XI of the ASME Code. Microchemical changes in high- and commercial-purity Type 304 SS specimens from control-blade absorber tubes and a control-blade sheath from operating BWRs were studied by Auger electron spectroscopy and scanning electron microscopy to determine whether trace impurity elements may contribute to IASCC of these materials.

  14. UV light inactivation of human and plant pathogens in unfiltered surface irrigation water.

    Science.gov (United States)

    Jones, Lisa A; Worobo, Randy W; Smart, Christine D

    2014-02-01

    Fruit and vegetable growers continually battle plant diseases and food safety concerns. Surface water is commonly used in the production of fruits and vegetables and can harbor both human- and plant-pathogenic microorganisms that can contaminate crops when used for irrigation or other agricultural purposes. Treatment methods for surface water are currently limited, and there is a need for suitable treatment options. A liquid-processing unit that uses UV light for the decontamination of turbid juices was analyzed for its efficacy in the treatment of surface waters contaminated with bacterial or oomycete pathogens, i.e., Escherichia coli, Salmonella enterica, Listeria monocytogenes, Clavibacter michiganensis subsp. michiganensis, Pseudomonas syringae pv. tomato, and Phytophthora capsici. Five-strain cocktails of each pathogen, containing approximately 10(8) or 10(9) CFU/liter for bacteria or 10(4) or 10(5) zoospores/liter for Ph. capsici, were inoculated into aliquots of two turbid surface water irrigation sources and processed with the UV unit. Pathogens were enumerated before and after treatment. In general, as the turbidity of the water source increased, the effectiveness of the UV treatment decreased, but in all cases, 99.9% or higher inactivation was achieved. Log reductions ranged from 10.0 to 6.1 and from 5.0 to 4.2 for bacterial pathogens and Ph. capsici, respectively.

  15. Environmentally assisted cracking in Light Water Reactors: Semiannual report, April 1993--September 1993. Volume 17

    Energy Technology Data Exchange (ETDEWEB)

    Chopra, O.K.; Chung, H.M.; Karlsen, T.; Kassner, T.F.; Michaud, W.F.; Ruther, W.E.; Sanecki, J.E.; Shack, W.J.; Soppet, W.K. [Argonne National Lab., IL (United States)

    1994-06-01

    This report summarizes work performed by Argonne National Laboratory on fatigue and environmentally assisted cracking (EAC) in light water reactors (LWRS) during the six months from April 1993 to September 1993. EAC and fatigue of piping, pressure vessels, and core components in LWRs are important concerns as extended reactor lifetimes are envisaged. Topics that have been investigated include (a) fatigue of low-alloy steel used in piping, steam generators, and reactor pressure vessels; (b) EAC of cast stainless steels (SSs); and (c) radiation-induced segregation and irradiation-assisted stress corrosion cracking of Type 304 SS after accumulation of relatively high fluence. Fatigue tests were conducted on medium-sulfur-content A106-Gr B piping and A533-Gr B pressure vessel steels in simulated PWR water and in air. Additional crack growth data were obtained on fracture-mechanics specimens of cast austenitic SSs in the as-received and thermally aged conditions in simulated boiling-water reactor (BWR) water at 289{degree}C. The data were compared with predictions based on crack growth correlations for wrought austenitic SS in oxygenated water developed at ANL and rates in air from Section 11 of the ASME Code. Microchemical and microstructural changes in high- and commercial-purity Type 304 SS specimens from control-blade absorber tubes and a control-blade sheath from operating BWRs were studied by Auger electron spectroscopy and scanning electron microscopy.

  16. Environmentally assisted cracking in light water reactors. Semiannual report July 1996--December 1996

    Energy Technology Data Exchange (ETDEWEB)

    Chopra, O.K.; Chung, H.M.; Gavenda, D.J. [Argonne National Lab., IL (United States)] [and others

    1997-10-01

    This report summarizes work performed by Argonne National Laboratory on fatigue and environmentally assisted cracking (EAC) in light water reactors from July 1996 to December 1996. Topics that have been investigated include (a) fatigue of carbon, low-alloy, and austenitic stainless steels (SSs) used in reactor piping and pressure vessels, (b) irradiation-assisted stress corrosion cracking of Type 304 SS, (c) EAC of Alloy 600, and (d) characterization of residual stresses in welds of boiling water reactor (BWR) core shrouds by numerical models. Fatigue tests were conducted on ferritic and austenitic SSs in water that contained various concentrations of dissolved oxygen to determine whether a slow strain rate applied during various portions of a tensile-loading cycle are equally effective in decreasing fatigue life. Slow-strain-rate-tensile tests were conducted in simulated BWR water at 288 C on SS specimens irradiated to a low fluence in the Halden reactor and the results were compared with similar data from a control-blade sheath and neutron-absorber tubes irradiated in BWRs to the same fluence level. Crack-growth-rate tests were conducted on compact-tension specimens from a low-carbon content heat of Alloy 600 in high-purity oxygenated water at 289 C. Residual stresses and stress intensity factors were calculated for BWR core shroud welds.

  17. Inert matrix fuel neutronic, thermal-hydraulic, and transient behavior in a light water reactor

    Science.gov (United States)

    Carmack, W. J.; Todosow, M.; Meyer, M. K.; Pasamehmetoglu, K. O.

    2006-06-01

    Currently, commercial power reactors in the United States operate on a once-through or open cycle, with the spent nuclear fuel eventually destined for long-term storage in a geologic repository. Since the fissile and transuranic (TRU) elements in the spent nuclear fuel present a proliferation risk, limit the repository capacity, and are the major contributors to the long-term toxicity and dose from the repository, methods and systems are needed to reduce the amount of TRU that will eventually require long-term storage. An option to achieve a reduction in the amount, and modify the isotopic composition of TRU requiring geological disposal is 'burning' the TRU in commercial light water reactors (LWRs) and/or fast reactors. Fuel forms under consideration for TRU destruction in light water reactors (LWRs) include mixed-oxide (MOX), advanced mixed-oxide, and inert matrix fuels. Fertile-free inert matrix fuel (IMF) has been proposed for use in many forms and studied by several researchers. IMF offers several advantages relative to MOX, principally it provides a means for reducing the TRU in the fuel cycle by burning the fissile isotopes and transmuting the minor actinides while producing no new TRU elements from fertile isotopes. This paper will present and discuss the results of a four-bundle, neutronic, thermal-hydraulic, and transient analyses of proposed inert matrix materials in comparison with the results of similar analyses for reference UOX fuel bundles. The results of this work are to be used for screening purposes to identify the general feasibility of utilizing specific inert matrix fuel compositions in existing and future light water reactors. Compositions identified as feasible using the results of these analyses still require further detailed neutronic, thermal-hydraulic, and transient analysis study coupled with rigorous experimental testing and qualification.

  18. Guidance for Developing Principal Design Criteria for Advanced (Non-Light Water) Reactors

    Energy Technology Data Exchange (ETDEWEB)

    Holbrook, Mark [Idaho National Lab. (INL), Idaho Falls, ID (United States); Kinsey, Jim [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2015-03-01

    In July 2013, the US Department of Energy (DOE) and US Nuclear Regulatory Commission (NRC) established a joint initiative to address a key portion of the licensing framework essential to advanced (non-light water) reactor technologies. The initiative addressed the “General Design Criteria for Nuclear Power Plants,” Appendix A to10 Code of Federal Regulations (CFR) 50, which were developed primarily for light water reactors (LWRs), specific to the needs of advanced reactor design and licensing. The need for General Design Criteria (GDC) clarifications in non-LWR applications has been consistently identified as a concern by the industry and varied stakeholders and was acknowledged by the NRC staff in their 2012 Report to Congress1 as an area for enhancement. The initiative to adapt GDC requirements for non-light water advanced reactor applications is being accomplished in two phases. Phase 1, managed by DOE, consisted of reviews, analyses and evaluations resulting in recommendations and deliverables to NRC as input for NRC staff development of regulatory guidance. Idaho National Laboratory (INL) developed this technical report using technical and reactor technology stakeholder inputs coupled with analysis and evaluations provided by a team of knowledgeable DOE national laboratory personnel with input from individual industry licensing consultants. The DOE national laboratory team reviewed six different classes of emerging commercial reactor technologies against 10 CFR 50 Appendix A GDC requirements and proposed guidance for their adapted use in non-LWR applications. The results of the Phase 1 analysis are contained in this report. A set of draft Advanced Reactor Design Criteria (ARDC) has been proposed for consideration by the NRC in the establishment of guidance for use by non-LWR designers and NRC staff. The proposed criteria were developed to preserve the underlying safety bases expressed by the original GDC, and recognizing that advanced reactors may take

  19. Photoelectrolysis of water at high current density - Use of laser light excitation of semiconductor-based photoelectrochemical cells

    Science.gov (United States)

    Wrighton, M. S.; Bocarsley, A. B.; Bolts, J. M.

    1978-01-01

    In the present paper, some results are given for UV laser light irradiation of the photoanode (SnO2, SrTiO3, or TiO2) in a cell for the light-driven electrolysis of H2O, at radiation intensities of up to 380 W/sq cm. The properties of the anode material are found to be independent of light intensity. Conversion of UV light to stored chemical energy in the form of 2H2/O2 from H2O was driven at a rate of up to 30 W/sq cm. High O2 evolution rates at the irradiated anodes without changes in the current-voltage curves are attributed to the excess oxidizing power associated with photogenerated holes. A test for this sort of hypothesis for H2 evolution at p-type materials is proposed.

  20. Photoelectrolysis of water at high current density - Use of laser light excitation of semiconductor-based photoelectrochemical cells

    Science.gov (United States)

    Wrighton, M. S.; Bocarsley, A. B.; Bolts, J. M.

    1978-01-01

    In the present paper, some results are given for UV laser light irradiation of the photoanode (SnO2, SrTiO3, or TiO2) in a cell for the light-driven electrolysis of H2O, at radiation intensities of up to 380 W/sq cm. The properties of the anode material are found to be independent of light intensity. Conversion of UV light to stored chemical energy in the form of 2H2/O2 from H2O was driven at a rate of up to 30 W/sq cm. High O2 evolution rates at the irradiated anodes without changes in the current-voltage curves are attributed to the excess oxidizing power associated with photogenerated holes. A test for this sort of hypothesis for H2 evolution at p-type materials is proposed.

  1. Study of High Fluence Radiation-induced Swelling and Hardening under Light Water Reactor Conditions

    Energy Technology Data Exchange (ETDEWEB)

    Golubov, Stanislav I. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Barashev, Alexander V. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Stoller, Roger E. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2016-09-01

    This report documents a comprehensive model that has been developed to enable simulations of microstructural evolution under the irradiation conditions typical of light water reactor (LWR) internal components. The model, which accounts cascade production of point defects and vacancy, interstitial faulted dislocation loops, interstitial clusters migrating one-dimensionally and the evolution of the network dislocation structure, has been parameterized to account damage accumulation in austenitic stainless steels. Nucleation and growth of an ensemble of cavities is based on accounting the residual and produced by irradiation He atoms and existence of the dislocation and production biases. Additional applications and potential future developments for the model are also discussed.

  2. Development of Advanced High Uranium Density Fuels for Light Water Reactors

    Energy Technology Data Exchange (ETDEWEB)

    Blanchard, James [Univ. of Wisconsin, Madison, WI (United States); Butt, Darryl [Boise State Univ., ID (United States); Meyer, Mitchell [Idaho National Lab. (INL), Idaho Falls, ID (United States); Xu, Peng [Westinghouse Electric Corporation, Pittsburgh, PA (United States)

    2016-02-15

    This work conducts basic materials research (fabrication, radiation resistance, thermal conductivity, and corrosion response) on U3Si2 and UN, two high uranium density fuel forms that have a high potential for success as advanced light water reactor (LWR) fuels. The outcome of this proposed work will serve as the basis for the development of advance LWR fuels, and utilization of such fuel forms can lead to the optimization of the fuel performance related plant operating limits such as power density, power ramp rate and cycle length.

  3. Theoretical Models of Light Scattering Applied in Sizing Particles in Coal Water Slurry

    Institute of Scientific and Technical Information of China (English)

    王仁哲; 张荣曾; 徐志强

    2004-01-01

    Advantges and disadvantage of Mie scattering model and Fraunhofer diffraction model are discussed. The result shows that 1) the Fraunhofer diffraction model is simple in design and fast in operation, which is quite suitable for on-line control and 2) the intensity and energy distribution of diffracted light of both the Mie scattering model and the Fraunhofer theoretical model are compared and researched. Feasibility of using the Fraunhofer diffraction model to replace the Mie scattering model in measuring particles in coal water slurry is demonstrated.

  4. Variation in pupil diameter in North American Gartersnakes (Thamnophis) is regulated by immersion in water, not by light intensity.

    Science.gov (United States)

    Fontenot, Clifford L

    2008-07-01

    A variable pupil generally regulates the amount of incoming light available for image formation on the retina. However, some of the semi-aquatic snakes (North American Gartersnakes, Thamnophis) that forage in relatively low light conditions reduce the pupil aperture in response to submergence underwater at the expense incoming light. Given that these snakes have all-cone retinas, reduction of incoming light because of pupillary constriction upon immersion seems counterintuitive. To test the effect of light and water on pupil aperture, three species of North American Gartersnakes (T. atratus, T. hammondii, and T. sirtalis) were exposed to nine light intensities in air and water. There was no effect of light on relative pupil aperture for any species. However, all three species showed a significant reduction in pupil aperture upon submergence underwater. The lack of a light response is surprising, and may be related to the method of accommodation in snakes. Snakes lack a ciliary muscle, and move the lens by constricting the pupil, which increases pressure in the posterior chamber and pushes the lens forward. Upon submergence, the snakes may be attempting to overcome the change in refractive index and defocus imposed by the water, by constricting the pupil. Thus, having the iris muscle involved in accommodation may preclude it from much of a light regulating function.

  5. Clustering in Water Based Magnetic Nanofluids: Investigations by Light Scattering Methods

    Science.gov (United States)

    Socoliuc, Vlad; Taculescu, Alina; Podaru, Camelia; Dobra, Andreea; Daia, Camelia; Marinica, Oana; Turcu, Rodica; Vekas, Ladislau

    2010-12-01

    Nanosized magnetite particles, with mean physical diameter of about 7 nm, obtained by chemical coprecipitation procedure were dispersed in water carrier by applying sterical stabilization of particles in order to prevent their aggregation and to ensure colloidal stability of the systems. Different chain length (C12, C14, C18) carboxylic acids (lauric (LA), myristic (MA) and oleic (OA)) were used for double layer coating of magnetite nanoparticles. Structural and magnetic properties were investigated by electron microscopy (TEM), dynamical and static light scattering (DLS, SLS) and magnetometry (VSM) to evaluate the role of chain length and of the saturated/unsaturated nature of surfactant layers. Also investigated were two water based magnetic nanocomposites obtained by encapsulating the magnetic nanoparticles in polymers with different functional properties.

  6. Carrier dynamics of a visible-light-responsive Ta3N5 photoanode for water oxidation

    KAUST Repository

    Ziani, Ahmed

    2015-01-01

    The physicochemical properties of a tantalum nitride (Ta3N5) photoanode were investigated in detail to understand the fundamental aspects associated with the photoelectrochemical (PEC) water oxidation. The Ta3N5 thin films were synthesized using DC magnetron sputtering followed by annealing in air and nitridation under ammonia (NH3). A polycrystalline structure with a dense morphology of the monoclinic Ta3N5 films was obtained. A relatively low absorption coefficient (104 to 105 cm-1) in the visible light range was measured for Ta3N5, consistent with the nature of the indirect band-gap. Ultra-fast spectroscopic measurements revealed that the Ta3N5 with different thicknesses films possess low transport properties and fast carrier recombination (<10 ps). These critical kinetic properties of Ta3N5 as a photoanode may necessitate high overpotentials to achieve appreciable photocurrents for water oxidation (onset ∼0.6 V vs. RHE). This journal is

  7. A review of iron species for visible-light photocatalytic water purification.

    Science.gov (United States)

    Jack, Russell S; Ayoko, Godwin A; Adebajo, Moses O; Frost, Ray L

    2015-05-01

    Iron species are one of the least toxic and least expensive substances that are photocatalytic in the visible region of the spectrum. Therefore, this article focuses on iron-based photocatalysts sensitive to visible light. Photo-Fenton reactions are considered with respect to those assisted by and involve the in situ production of H₂O₂. The possible role that photoactive iron species play by interacting with natural organic matter in water purification in the natural environment is considered. The review also considered photosensitization by phthalocyanines and the potential role that layered double hydroxides may have not only as catalyst supports but also as photosensitizers themselves. Finally, photocatalytic disinfection of water is discussed, and the desirability of standardized metrics and experimental conditions to assist in the comparative evaluation of photocatalysts is highlighted.

  8. Visible light photoactivity of Polypropylene coated Nano-TiO2 for dyes degradation in water

    Science.gov (United States)

    Giovannetti, R.; Amato, C. A. D.'; Zannotti, M.; Rommozzi, E.; Gunnella, R.; Minicucci, M.; di Cicco, A.

    2015-12-01

    The use of Polypropylene as support material for nano-TiO2 photocatalyst in the photodegradation of Alizarin Red S in water solutions under the action of visible light was investigated. The optimization of TiO2 pastes preparation using two commercial TiO2, Aeroxide P-25 and Anatase, was performed and a green low-cost dip-coating procedure was developed. Scanning electron microscopy, Atomic Force Microscopy and X-Ray Diffraction analysis were used in order to obtain morphological and structural information of as-prepared TiO2 on support material. Equilibrium and kinetics aspects in the adsorption and successive photodegradation of Alizarin Red S, as reference dye, are described using polypropylene-TiO2 films in the Visible/TiO2/water reactor showing efficient dyes degradation.

  9. Criticality benchmark guide for light-water-reactor fuel in transportation and storage packages

    Energy Technology Data Exchange (ETDEWEB)

    Lichtenwalter, J.J.; Bowman, S.M.; DeHart, M.D.; Hopper, C.M.

    1997-03-01

    This report is designed as a guide for performing criticality benchmark calculations for light-water-reactor (LWR) fuel applications. The guide provides documentation of 180 criticality experiments with geometries, materials, and neutron interaction characteristics representative of transportation packages containing LWR fuel or uranium oxide pellets or powder. These experiments should benefit the U.S. Nuclear Regulatory Commission (NRC) staff and licensees in validation of computational methods used in LWR fuel storage and transportation concerns. The experiments are classified by key parameters such as enrichment, water/fuel volume, hydrogen-to-fissile ratio (H/X), and lattice pitch. Groups of experiments with common features such as separator plates, shielding walls, and soluble boron are also identified. In addition, a sample validation using these experiments and a statistical analysis of the results are provided. Recommendations for selecting suitable experiments and determination of calculational bias and uncertainty are presented as part of this benchmark guide.

  10. Observation of bubble formation in water during microwave irradiation by dynamic light scattering

    Science.gov (United States)

    Asakuma, Yusuke; Munenaga, Takuya; Nakata, Ryosuke

    2016-09-01

    A microwave reactor was designed for in situ observation of nano- and micro-bubbles, and size profiles during and after irradiation were measured with respect to irradiation power and time. Bubble formation in water during irradiation was observed even at temperatures below the boiling point of water. The maximum size strongly depended on radiation power and time, even at a given temperature. Nano-particles in the dispersion medium were found to play an important role in achieving more stable nucleation of bubbles around particles, and stable size distributions were obtained from clear autocorrelation by a dynamic light scattering system. Moreover, a combination of microwave induction heating and the addition of nano-particles to the dispersion medium can prevent heterogeneous nucleation of bubbles on the cell wall. Quantitative nano-bubble size profiles obtained by in situ observation provide useful information regarding microwave-based industrial processes for nano-particle production.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2009-03-15

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

  12. Study of Oil/Water Interfacial Tension of Vacuum Residual Fractions from Iranian Light Crude Oil

    Institute of Scientific and Technical Information of China (English)

    彭勃; 李明远; 赵锁奇; 吴肇亮; JohanSjoblom; HaraldHoiland

    2003-01-01

    The vacuum residual from Iranian Light crude oil are separated into a series of 16 narrow fractions according to the molecular weight by the supercritical fluid extraction and fractional (SFEF) technology. The chemical element and the UV spectrum of each fraction are analyzed. The effects of several factors on the interfacial tension are investigated, which are the fraction concentration in oil phase, the ratio of oil component, the salts dissolved in the water phase and the pH value. The interfacial tension decreases rapidly as the concentration of the residual fraction in the oil increases, showing a higher interfacial activity of the fraction. The interfacial tension changes, as the amount of absorption or the state of the fractions in the interface changes resulting from different ratios of oil, different kinds or concentrations of salts in water, and different pH values. It is concluded that the intrfacial tension changes regularly, corresponding to the regular molecular parameters of the vacuum residual fractions.

  13. Shippingport operations with the Light Water Breeder Reactor core. (LWBR Development Program)

    Energy Technology Data Exchange (ETDEWEB)

    Budd, W.A. (ed.)

    1986-03-01

    This report describes the operation of the Shippingport Atomic Power Station during the LWBR (Light Water Breeder Reactor) Core lifetime. It also summarizes the plant-oriented operations during the period preceding LWBR startup, which include the defueling of The Pressurized Water Reactor Core 2 (PWR-2) and the installation of the LWBR Core, and the operations associated with the defueling of LWBR. The intent of this report is to examine LWBR experience in retrospect and present pertinent and significant aspects of LWBR operations that relate primarily to the nuclear portion of the Station. The nonnuclear portion of the Station is discussed only as it relates to overall plant operation or to unusual problems which result from the use of conventional equipment in radioactive environments. 30 refs., 69 figs., 27 tabs.

  14. Nanostructure of Metallic Particles in Light Water Reactor Used Nuclear Fuel

    Energy Technology Data Exchange (ETDEWEB)

    Buck, Edgar C. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Mausolf, Edward J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Mcnamara, Bruce K. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Soderquist, Chuck Z. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Schwantes, Jon M. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2015-03-11

    The extraordinary nano-structure of metallic particles in light water reactor fuels points to possible high reactivity through increased surface area and a high concentration of high energy defect sites. We have analyzed the metallic epsilon particles from a high burn-up fuel from a boiling water reactor using transmission electron microscopy and have observed a much finer nanostructure in these particles than has been reported previously. The individual round particles that varying in size between ~20 and ~50 nm appear to consist of individual crystallites on the order of 2-3 nm in diameter. It is likely that in-reactor irradiation induce displacement cascades results in the formation of the nano-structure. The composition of these metallic phases is variable yet the structure of the material is consistent with the hexagonal close packed structure of epsilon-ruthenium. These findings suggest that unusual catalytic behavior of these materials might be expected, particularly under accident conditions.

  15. Light tracking through ice and water -- Scattering and absorption in heterogeneous media with Photonics

    CERN Document Server

    Lundberg, J; Woschnagg, K; Burgess, T; Adams, J; Hundertmark, S; Desiati, P; Niessen, P

    2007-01-01

    In the field of neutrino astronomy, large volumes of optically transparent matter like glacial ice, lake water, or deep ocean water are used as detector media. Elementary particle interactions are studied using in situ detectors recording time distributions and fluxes of the faint photon fields of Cherenkov radiation generated by ultra-relativistic charged particles, typically muons or electrons. The Photonics software package was developed to determine photon flux and time distributions throughout a volume containing a light source through Monte Carlo simulation. Photons are propagated and time distributions are recorded throughout a cellular grid constituting the simulation volume, and Mie scattering and absorption are realised using wavelength and position dependent parameterisations. The photon tracking results are stored in binary tables for transparent access through ANSI-C and C++ interfaces. For higher-level physics applications, like simulation or reconstruction of particle events, it is then possibl...

  16. Dose-to-water conversion for the backscatter-shielded EPID: A frame-based method to correct for EPID energy response to MLC transmitted radiation

    Energy Technology Data Exchange (ETDEWEB)

    Zwan, Benjamin J., E-mail: benjamin.zwan@uon.edu.au; O’Connor, Daryl J. [School of Mathematical and Physical Sciences, University of Newcastle, Newcastle, New South Wales 2308 (Australia); King, Brian W. [Department of Radiation Oncology, Massey Cancer Center, Virginia Commonwealth University Health System, Richmond, Virginia 23298 (United States); Greer, Peter B. [School of Mathematical and Physical Sciences, University of Newcastle, Newcastle, New South Wales 2308, Australia and Department of Radiation Oncology, Calvary Mater Newcastle Hospital, Newcastle, New South Wales 2310 (Australia)

    2014-08-15

    Purpose: To develop a frame-by-frame correction for the energy response of amorphous silicon electronic portal imaging devices (a-Si EPIDs) to radiation that has transmitted through the multileaf collimator (MLC) and to integrate this correction into the backscatter shielded EPID (BSS-EPID) dose-to-water conversion model. Methods: Individual EPID frames were acquired using a Varian frame grabber and iTools acquisition software then processed using in-house software developed inMATLAB. For each EPID image frame, the region below the MLC leaves was identified and all pixels in this region were multiplied by a factor of 1.3 to correct for the under-response of the imager to MLC transmitted radiation. The corrected frames were then summed to form a corrected integrated EPID image. This correction was implemented as an initial step in the BSS-EPID dose-to-water conversion model which was then used to compute dose planes in a water phantom for 35 IMRT fields. The calculated dose planes, with and without the proposed MLC transmission correction, were compared to measurements in solid water using a two-dimensional diode array. Results: It was observed that the integration of the MLC transmission correction into the BSS-EPID dose model improved agreement between modeled and measured dose planes. In particular, the MLC correction produced higher pass rates for almost all Head and Neck fields tested, yielding an average pass rate of 99.8% for 2%/2 mm criteria. A two-sample independentt-test and fisher F-test were used to show that the MLC transmission correction resulted in a statistically significant reduction in the mean and the standard deviation of the gamma values, respectively, to give a more accurate and consistent dose-to-water conversion. Conclusions: The frame-by-frame MLC transmission response correction was shown to improve the accuracy and reduce the variability of the BSS-EPID dose-to-water conversion model. The correction may be applied as a preprocessing step

  17. Parameterization of light scattering for solving the inverse problem of determining the concentrations of the principal light scattering and absorbing admixtures in shelf waters

    Directory of Open Access Journals (Sweden)

    Vadim N. Pelevin

    2001-12-01

    Full Text Available A method for estimating the water backscattering coefficient was put forward on the basis of experimental data of diffuse attenuation coefficient for downwelling irradiance and irradiance reflectance. Calculations were carried out for open sea waters of different types and the spectral dependencies were found ("anomalous" spectra and explained. On this basis, a new model of light backscattering on particles in the sea is proposed. This model may be useful for modelling remote sensing reflectance spectra in order to solve the inverse problems of estimating the concentration of natural admixtures in shelf waters.

  18. Measurement of solubility and water sorption of dental nanocomposites light cured by argon laser.

    Science.gov (United States)

    Mirsasaani, Seyed Shahabeddin; Ghomi, Farhad; Hemati, Mehran; Tavasoli, Tina

    2013-03-01

    Different parameters used for photoactivation process and also composition provide changes in the properties of dental composites. In the present work the effect of different power density of argon laser and filler loading on solubility (SL) and water sorption (WS) of light-cure dental nanocomposites was studied. The resin of nanocomposites was prepared by mixing bisphenol A glycol dimethacrylate (Bis-GMA) and triethylene glycol dimethacrylate (TEGDMA) with a mass ratio of 65/35. 20 wt.% and 25 wt.% of nanosilica fillers with a primary particle size of 10 nm were added to the resin. Camphorquinone (CQ) and DMAEMA were added as photoinitiator system. The nanocomposites were cured by applying the laser beam at the wavelength of 472 nm and power densities of 260 and 340 mW/cm(2) for 40 sec. Solubility and water sorption were then measured according to ISO 4049, which in our case, the maximums were 2.2% and 4.3% at 260 mW/cm(2) and 20% filler, respectively. The minimum solubility (1.2%) and water sorption (3.8%) were achieved for the composite containing 25% filler cured at 340 mW/cm(2). The results confirmed that higher power density and filler loading decreased solubility of unreacted monomers and water sorption and improved physico-mechanical properties of nanocomposites.

  19. Technologies For Maintaining Animals In Space: Lighting, Air Quality, Noise, Food And Water

    Science.gov (United States)

    Winget, C. M.; Skidmore, M. G.; Holley, D. C.; Dalton, Bonnie P. (Technical Monitor)

    1995-01-01

    In the terrestrial environment multiple time cues exist. Zeitgebers have been identified and studied for their ability to convey temporal information to various physiological systems. In the microgravity experiment it is necessary to define time cues within the flight hardware prior to flight. During flight if changes in the Circadian System (e.g., mean, phase angle, period) occur this would indicate that the gravity vector is important relative to biological timing. This presentation is concerned with the environmental parameter: to support rodent experiments in microgravity. The Animal Enclosure Module (AEM) provides solid food bars and water via lixits and ad libitum. Flight animals (Sprague-Dawley rats, 60 - 300g) when compared to ground controls show similar growth (mean growth per day g, plus or minus SD; flight 5.4 plus or minus 2.0, ground 5.9 plus or minus 2.1). Current AEMs use incandescent lighting (approx. 5 Lux). Light emitting diode (LED) arrays are being developed that provide a similar light environment as cool-white fluorescent sources (40 Lux). In ground based tests (12L:12D), these arrays show normal circadian entrainment (Tau = 24.0) with respect to the behavioral responses, measured (drinking, eating, gross locomotor activity). A newly developed ultra high efficiency filter system can entrap all feces, urine and odors from 6 rats for 24 days. Maximum sound level exposure limits (per octave band 22 Hz - 179 kHz) have been established. The AEM will effectively support animal experiments in microgravity.

  20. Technologies For Maintaining Animals In Space: Lighting, Air Quality, Noise, Food And Water

    Science.gov (United States)

    Winget, C. M.; Skidmore, M. G.; Holley, D. C.; Dalton, Bonnie P. (Technical Monitor)

    1995-01-01

    In the terrestrial environment multiple time cues exist. Zeitgebers have been identified and studied for their ability to convey temporal information to various physiological systems. In the microgravity experiment it is necessary to define time cues within the flight hardware prior to flight. During flight if changes in the Circadian System (e.g., mean, phase angle, period) occur this would indicate that the gravity vector is important relative to biological timing. This presentation is concerned with the environmental parameter: to support rodent experiments in microgravity. The Animal Enclosure Module (AEM) provides solid food bars and water via lixits and ad libitum. Flight animals (Sprague-Dawley rats, 60 - 300g) when compared to ground controls show similar growth (mean growth per day g, plus or minus SD; flight 5.4 plus or minus 2.0, ground 5.9 plus or minus 2.1). Current AEMs use incandescent lighting (approx. 5 Lux). Light emitting diode (LED) arrays are being developed that provide a similar light environment as cool-white fluorescent sources (40 Lux). In ground based tests (12L:12D), these arrays show normal circadian entrainment (Tau = 24.0) with respect to the behavioral responses, measured (drinking, eating, gross locomotor activity). A newly developed ultra high efficiency filter system can entrap all feces, urine and odors from 6 rats for 24 days. Maximum sound level exposure limits (per octave band 22 Hz - 179 kHz) have been established. The AEM will effectively support animal experiments in microgravity.

  1. Biological conversion of synthesis gas

    Energy Technology Data Exchange (ETDEWEB)

    Klasson, K.T.; Basu, R.; Johnson, E.R.; Clausen, E.C.; Gaddy, J.L.

    1992-03-01

    Mass transfer and kinetic studies were carried out for the Rhodospirillum rubrum and Chlorobium thiosulfatophilum bacterial systems. R. rubrum is a photosynthetic anaerobic bacterium which catalyzes the biological water gas shift reaction: CO + H[sub 2]0 [yields] CO[sub 2] + H[sub 2]. C. thiosulfatophilum is also a H[sub 2]S and COS to elemental sulfur. The growth of R. rubrum may be satisfactorily carried out at 25[degree] and 30[degree]C, while CO uptake and thus the conversion of CO best occurs at temperatures of either 30[degree], 32[degree] or 34[degree]C. The rate of conversion of COs and H[sub 2]O to CO[sub 2] and H[sub 2]S may be modeled by a first order rate expression. The rate constant at 30[degree]C was found to be 0.243 h[sup [minus]1]. The growth of C. thiosulfatophilum may be modeled in terms of incoming light intensity using a Monod equation: [mu] = [sub 351] + I[sub o]/[sup 0.152]I[sub o]. Comparisons of the growth of R. rubrum and C. thiosulfatophilum shows that the specific growth rate of C. thiosulfatophilum is much higher at a given light intensity.

  2. Phases equilibria at low temperature between light hydrocarbons mixtures, methanol and water: measures and simulation

    Energy Technology Data Exchange (ETDEWEB)

    Rossilhol, N.

    1995-12-01

    In this work we discuss phase equilibria of mixtures similar to those formed during natural gas treatment (transportation and purification). The mixtures can contain light hydrocarbons (methane, ethane, propane, etc), acid gases (hydrogen sulfide, carbon dioxide), methanol (solvent, inhibitor) and (water). We present a low temperature phase equilibrium equipment to obtain two and three phase equilibrium data of light hydrocarbon-methanol-water mixtures. The realisation of the equipment, the measuring procedure and some determination of binary, ternary and quaternary systems are described. The range of application is - 100 deg. C to 0 deg. C in temperature and between 0 and 100 bar in pressure. The binary subsystems of the systems mentioned above are calculated in order to study the possibilities of the MHV2 and Wong and Sandler methods to represent simultaneously their vapor-liquid and liquid-liquid equilibria. According to the formalism proposed by the two methods, the cubic Soave-Redlich-Kwong equation of state is systematically combined with the NRTL excess Gibbs energy model. (authors). 72 refs., 47 figs., 38 tabs.

  3. Commercial Light Water Reactor -Tritium Extraction Facility Process Waste Assessment (Project S-6091)

    Energy Technology Data Exchange (ETDEWEB)

    Hsu, R.H.; Delley, A.O.; Alexander, G.J.; Clark, E.A.; Holder, J.S.; Lutz, R.N.; Malstrom, R.A.; Nobles, B.R. [Westinghouse Savannah River Co., Aiken, SC (United States); Carson, S.D. [Sandia National Laboratories, New Mexico, NM (United States); Peterson, P.K. [Sandia National Laboratories, New Mexico, NM (United States)

    1997-11-30

    The Savannah River Site (SRS) has been tasked by the Department of Energy (DOE) to design and construct a Tritium Extraction Facility (TEF) to process irradiated tritium producing burnable absorber rods (TPBARs) from a Commercial Light Water Reactor (CLWR). The plan is for the CLWR-TEF to provide tritium to the SRS Replacement Tritium Facility (RTF) in Building 233-H in support of DOE requirements. The CLWR-TEF is being designed to provide 3 kg of new tritium per year, from TPBARS and other sources of tritium (Ref. 1-4).The CLWR TPBAR concept is being developed by Pacific Northwest National Laboratory (PNNL). The TPBAR assemblies will be irradiated in a Commercial Utility light water nuclear reactor and transported to the SRS for tritium extraction and processing at the CLWR-TEF. A Conceptual Design Report for the CLWR-TEF Project was issued in July 1997 (Ref. 4).The scope of this Process Waste Assessment (PWA) will be limited to CLWR-TEF processing of CLWR irradiated TPBARs. Although the CLWR- TEF will also be designed to extract APT tritium-containing materials, they will be excluded at this time to facilitate timely development of this PWA. As with any process, CLWR-TEF waste stream characteristics will depend on process feedstock and contaminant sources. If irradiated APT tritium-containing materials are to be processed in the CLWR-TEF, this PWA should be revised to reflect the introduction of this contaminant source term.

  4. Application of Photocatalysts and LED Light Sources in Drinking Water Treatment

    Directory of Open Access Journals (Sweden)

    Gopal Achari

    2013-09-01

    Full Text Available This study investigates a cross-section of TiO2 compositions for which existing evidence suggests the prospect of improved performance compared to standard Degussa P25. In the context of a program aimed toward a 365 nm LED based photo-reactor, the question is whether a distinctly superior photocatalyst composition for drinking water treatment is now available that would shape design choices. An answer was sought by synthesizing several photocatalysts with reported high reactivity in some context in the literature, and by performing photocatalysts reactivity tests using common pollutants of water system including Natural Organic Matter (NOM and Emerging Contaminants (ECs from the pesticide and pharmaceutical classes. 365 nm Light Emitting Diodes (LEDs were used as the irradiation source. Since LEDs are now available in the UV, we did not examine the TiO2 modifications that bring band gap excitation into the region beyond 400 nm. The results suggest that the choice of the photocatalyst should be best made to fit the reactor design and photocatalyst mounting constraints such as mass transport, reactive surface, and light field. No photocatalyst composition overall, superior for all classes emerged.

  5. Standard Practice for Design of Surveillance Programs for Light-Water Moderated Nuclear Power Reactor Vessels

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2010-01-01

    1.1 This practice covers procedures for designing a surveillance program for monitoring the radiation-induced changes in the mechanical properties of ferritic materials in light-water moderated nuclear power reactor vessels. This practice includes the minimum requirements for the design of a surveillance program, selection of vessel material to be included, and the initial schedule for evaluation of materials. 1.2 This practice was developed for all light-water moderated nuclear power reactor vessels for which the predicted maximum fast neutron fluence (E > 1 MeV) at the end of license (EOL) exceeds 1 × 1021 neutrons/m2 (1 × 1017 n/cm2) at the inside surface of the reactor vessel. 1.3 This practice applies only to the planning and design of surveillance programs for reactor vessels designed and built after the effective date of this practice. Previous versions of Practice E185 apply to earlier reactor vessels. 1.4 This practice does not provide specific procedures for monitoring the radiation induced cha...

  6. Environmentally assisted cracking in light water reactors. Semiannual report, October 1993--March 1994. Volume 18

    Energy Technology Data Exchange (ETDEWEB)

    Chung, H.M.; Chopra, O.K.; Erck, R.A.; Kassner, T.F.; Michaud, W.F.; Ruther, W.E.; Sanecki, J.E.; Shack, W.J.; Soppet, W.K. [Argonne National Lab., IL (United States)

    1995-03-01

    This report summarizes work performed by Argonne National Laboratory (ANL) on fatigue and environmentally assisted cracking (EAC) in light water reactors (LWRs) during the six months from October 1993 to March 1994. EAC and fatigue of piping, pressure vessels, and core components in LWRs are important concerns in operating plants and as extended reactor lifetimes are envisaged. Topics that have been investigated include (a) fatigue of low-alloy steel used in piping, steam generators, and reactor pressure vessels, (b) EAC of wrought and cast austenitic stainless steels (SSs), and (c) radiation-induced segregation and irradiation-assisted stress corrosion cracking (IASCC) of Type 304 SS after accumulation of relatively high fluence. Fatigue tests have been conducted on A302-Gr B low-alloy steel to verify whether the current predictions of modest decreases of fatigue life in simulated pressurized water reactor water are valid for high-sulfur heats that show environmentally enhanced fatigue crack growth rates. Additional crack growth data were obtained on fracture-mechanics specimens of austenitic SSs to investigate threshold stress intensity factors for EAC in high-purity oxygenated water at 289{degrees}C. The data were compared with predictions based on crack growth correlations for wrought austenitic SS in oxygenated water developed at ANL and rates in air from Section XI of the ASME Code. Microchemical and microstructural changes in high- and commercial-purity Type 304 SS specimens from control-blade absorber tubes and a control-blade sheath from operating boiling water reactors were studied by Auger electron spectroscopy and scanning electron microscopy to determine whether trace impurity elements, which are not specified in the ASTM specifications, may contribute to IASCC of solution-annealed materials.

  7. Drinking water treatment with ultraviolet light for travelers -- Evaluation of a mobile lightweight system.

    Science.gov (United States)

    Timmermann, Lisa F; Ritter, Klaus; Hillebrandt, David; Küpper, Thomas

    2015-01-01

    The SteriPEN(®) is a handheld device for disinfecting water with ultraviolet (UV) radiation. The manufacturer claims a reduction of at least 99.9% of bacteria, viruses, and protozoa. The present study intends to verify the general effectiveness of the device. Furthermore, the influence of bottle geometry and water movement is examined and the issue of user safety with regard to UV-C radiation is addressed. The device was applied on water containing a known number of microorganisms (Escherichia coli, Staphylococcus aureus, and the spore of Geobacillusstearothermophilus) and the survival rate was examined. Three different types of bottles commonly used among travelers served as test containers. All tests were conducted with and without agitating the water during irradiation. Furthermore, a spectral analysis was performed on the light of the device. The SteriPEN(®) reached a mean reduction of more than 99.99% of bacteria and 99.57% of the spores when applied correctly. However, the results of the trials without agitating the water only yielded a 94.98% germ reduction. The device's maximal radiation intensity lies at 254 nm which is the wavelength most efficient in inactivating bacteria. The UV-C fraction is filtered out completely by common bottle materials. However, when applied in larger containers a portion of the UV-C rays exits the water surface. If applied according to the instructions the device manages a satisfactory inactivation of bacteria. However, it bears the danger of user errors relevant to health. Therefore, education on the risks of incorrect application should be included in the travel medical consultation. Also there are still aspects that need to be subject to further independent research. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

  8. Environmentally assisted cracking in Light Water Reactors. Volume 16: Semiannual report, October 1992--March 1993

    Energy Technology Data Exchange (ETDEWEB)

    Chung, H.M.; Chopra, O.K.; Ruther, W.E.; Kassner, T.F.; Michaud, W.F.; Park, J.Y.; Sanecki, J.E.; Shack, W.J.

    1993-09-01

    This report summarizes work performed by Argonne National Laboratory on fatigue and environmentally assisted cracking (EAC) in light water reactors (LWRs) during the six months from October 1992 to March 1993. Fatigue and EAC of piping, pressure vessels, and core components in LWRs are important concerns as extended reactor lifetimes are envisaged. Topics that have been investigated include (1) fatigue of low-alloy steel used in piping, steam generators, and reactor pressure vessels. (2) EAC of cast stainless steels (SSs), (3) radiation-induced segregation and irradiation-assisted stress corrosion cracking of Type 304 SS after accumulation of relatively high fluence, and (4) EAC of low-alloy steels. Fatigue tests were conducted on medium-sulfur-content A106-Gr B piping and A533-Gr B pressure vessel steels in simulated PWR water and in air. Additional crack growth data were obtained on fracture-mechanics specimens of cast austenitic SSs in the as-received and thermally aged conditions and chromium-nickel-plated A533-Gr B steel in simulated boiling-water reactor (BWR) water at 289{degrees}C. The data were compared with predictions based on crack growth correlations for ferritic steels in oxygenated water and correlations for wrought austenitic SS in oxygenated water developed at ANL and rates in air from Section XI of the ASME Code. Microchemical and microstructural changes in high- and commercial-purity Type 304 SS specimens from control-blade absorber tubes and a control-blade sheath from operating BWRs were studied by Auger electron spectroscopy and scanning electron microscopy.

  9. Facile oxidative conversion of TiH2 to high-concentration Ti(3+)-self-doped rutile TiO2 with visible-light photoactivity.

    Science.gov (United States)

    Grabstanowicz, Lauren R; Gao, Shanmin; Li, Tao; Rickard, Robert M; Rajh, Tijana; Liu, Di-Jia; Xu, Tao

    2013-04-01

    TiO2, in the rutile phase with a high concentration of self-doped Ti(3+), has been synthesized via a facile, all inorganic-based, and scalable method of oxidizing TiH2 in H2O2 followed by calcinations in Ar gas. The material was shown to be photoactive in the visible-region of the electromagnetic spectrum. Powdered X-ray diffraction (PXRD), transmission electron microscopy (TEM), ultraviolet-visible-near-infrared (UV-vis-NIR), diffuse reflectance spectroscopy (DRS), and Brunauer-Emmett-Teller (BET) methods were used to characterize the crystalline, structural, and optical properties and specific surface area of the as-synthesized Ti(3+)-doped rutile, respectively. The concentration of Ti(3+) was quantitatively studied by electron paramagnetic resonance (EPR) to be as high as one Ti(3+) per ~4300 Ti(4+). Furthermore, methylene blue (MB) solution and an industry wastewater sample were used to examine the photocatalytic activity of the Ti(3+)-doped TiO2 which was analyzed by UV-vis absorption, Fourier transform infrared spectroscopy (FT-IR), and electrospray ionization mass spectrometry (ESI-MS). In comparison to pristine anatase TiO2, our Ti(3+) self-doped rutile sample exhibited remarkably enhanced visible-light photocatalytic degradation on organic pollutants in water.

  10. New evaluation of thermal neutron scattering libraries for light and heavy water

    Directory of Open Access Journals (Sweden)

    Marquez Damian Jose Ignacio

    2017-01-01

    Full Text Available In order to improve the design and safety of thermal nuclear reactors and for verification of criticality safety conditions on systems with significant amount of fissile materials and water, it is necessary to perform high-precision neutron transport calculations and estimate uncertainties of the results. These calculations are based on neutron interaction data distributed in evaluated nuclear data libraries. To improve the evaluations of thermal scattering sub-libraries, we developed a set of thermal neutron scattering cross sections (scattering kernels for hydrogen bound in light water, and deuterium and oxygen bound in heavy water, in the ENDF-6 format from room temperature up to the critical temperatures of molecular liquids. The new evaluations were generated and processable with NJOY99 and also with NJOY-2012 with minor modifications (updates, and with the new version of NJOY-2016. The new TSL libraries are based on molecular dynamics simulations with GROMACS and recent experimental data, and result in an improvement of the calculation of single neutron scattering quantities. In this work, we discuss the importance of taking into account self-diffusion in liquids to accurately describe the neutron scattering at low neutron energies (quasi-elastic peak problem. To improve modeling of heavy water, it is important to take into account temperature-dependent static structure factors and apply Sköld approximation to the coherent inelastic components of the scattering matrix. The usage of the new set of scattering matrices and cross-sections improves the calculation of thermal critical systems moderated and/or reflected with light/heavy water obtained from the International Criticality Safety Benchmark Evaluation Project (ICSBEP handbook. For example, the use of the new thermal scattering library for heavy water, combined with the ROSFOND-2010 evaluation of the cross sections for deuterium, results in an improvement of the C/E ratio in 48 out of

  11. How do light and water acquisition strategies affect species selection during secondary succession in moist tropical forests?

    NARCIS (Netherlands)

    Schönbeck, Leonie; Lohbeck, Madelon; Bongers, Frans; Ramos, Miguel Martínez; Sterck, Frank

    2015-01-01

    Pioneer tree species have acquisitive leaf characteristics associated with high demand of light and water, and are expected to be shade and drought intolerant. Using leaf functional traits (specific leaf area, photosynthetic rate, relative water content and stomatal conductance) and tree performa

  12. Biomimetic fabrication of WO{sub 3} for water splitting under visible light with high performance

    Energy Technology Data Exchange (ETDEWEB)

    Yin, Chao; Zhu, Shenmin, E-mail: smzhu@sjtu.edu.cn; Yao, Fan; Gu, Jiajun; Zhang, Wang [Shanghai Jiao Tong University, State Key Laboratory of Metal Matrix Composites (China); Chen, Zhixin [University of Wollongong, Faculty of Engineering (Australia); Zhang, Di, E-mail: zhangdi@sjtu.edu.cn [Shanghai Jiao Tong University, State Key Laboratory of Metal Matrix Composites (China)

    2013-08-15

    Inspired by the high light-harvesting properties of typical butterfly wings, ceramic WO{sub 3} butterfly wings with hierarchical structures of bio-butterfly wings was fabricated using a template of PapilioParis butterfly wings through a sol-gel method. The effect of calcination temperatures on the structures of the ceramic butterfly wings was investigated and the results showed that the WO{sub 3} butterfly wing replica calcined at 550 Degree-Sign C (WO{sub 3} replica-550) is a single phase and has a high crystallinity and relatively fine hierarchical structure. The average grain size of WO{sub 3} replica-550 and WO{sub 3} powder are around 32.6 and 42.2 nm, respectively. Compared with pure WO{sub 3} powder, WO{sub 3} replica-550 demonstrated a higher light-harvesting capability in the region from 460 to 700 nm and more importantly the higher charge separation rate, as evidenced by electron paramagnetic resonance measurements. Photocatalytic O{sub 2} evolutions from water were investigated on the ceramic butterfly wings and pure WO{sub 3} powder under visible light ({lambda} > 420 nm). The results showed that the amount of O{sub 2} produced from WO{sub 3} replica-550 is 50 % higher than that of the pure WO{sub 3} powder. The improved photocatalytic performance of WO{sub 3} replica-550 is attributed to the quasi-honeycomb structure inherited from the PapilioParis butterfly wings, providing both high light-harvesting efficiency and efficient charge transport through the WO{sub 3}.

  13. Estimating the Effects of Conversion of Agricultural Land to Urban Land on Deep Percolation of Irrigation Water in the Grand Valley, Western Colorado

    Science.gov (United States)

    Mayo, John W.

    2008-01-01

    The conversion of agricultural land to urban residential land is associated with rapid population growth in the Grand Valley of western Colorado. Information regarding the effects of this land-use conversion on deep percolation, irrigation-water application, and associated salt loading to the Colorado River is needed to support water-resource planning and conservation efforts. The Natural Resources Conservation Service (NRCS) assessed deep percolation and estimated salt loading derived from irrigated agricultural lands in the Grand Valley in a 1985 to 2002 monitoring and evaluation study (NRCS M&E). The U.S. Geological Survey (USGS), in cooperation with the Colorado River Salinity Control Forum and the Mesa Conservation District, quantified the current (2005-2006) deep percolation and irrigation-water application characteristics of 1/4-acre residential lots and 5-acre estates, urban parks, and urban orchard grass fields in the Grand Valley, and compared the results to NRCS M&E results from alfalfa-crop sites. In addition, pond seepage from three irrigation-water holding ponds was estimated. Salt loading was estimated for the urban study results and the NRCS M&E results by using standard salt-loading factors. A daily soil-moisture balance calculation technique was used at all urban study irrigated sites. Deep percolation was defined as any water infiltrating below the top 12 inches of soil. Deep percolation occurred when the soil-moisture balance in the first 12 inches of soil exceeded the field capacity for the soil type at each site. Results were reported separately for urban study bluegrass-only sites and for all-vegetation type (bluegrass, native plants, and orchard grass) sites. Deep percolation and irrigation-water application also were estimated for a complete irrigation season at three subdivisions by using mean site data from each subdivision. It was estimated that for the three subdivisions, 37 percent of the developed acreage was irrigated (the balance

  14. Removal of light petroleum hydrocarbons from water sources using polypropylene and titanium dioxide nano-composite

    Directory of Open Access Journals (Sweden)

    H. Karyab

    2016-08-01

    Full Text Available Background: Petroleum hydrocarbons are the most important pollutants which threat human health and aquatics. Adsorbents are one of the common equipment in water pollution management; however, their applications have been associated with limitations. Objective: To evaluate the potential of polypropylene/titanium dioxide Nano-composite in adsorption of light petroleum hydrocarbons from water sources. Methods: This experimental study was conducted at school of health, Qazvin University of Medical Sciences in 2014-15. Activation of polypropylene fibers, with 1 cm length and 300 microns diameters, was achieved with wet heating. To synthesize of nano-composite the fibers were coated with nano-titanium dioxide with 20 nm diameter. The sonication was performed at 26 kHz and 100 W of power in 40ºc. The morphology of the fractured surfaces of impact specimens was examined by FESEM. The adsorption rate of petrol and gasoline, as surrogate of TPH, was evaluated in different retention time within polyamide mesh aperture diameter of 250 nm. Average of TPH adsorbing, per unit weight of adsorbent, were analyzed with analysis of variance and Scheffe post hoc tests. Findings: The FESEM micrographs showed that the dispersion of the nano-Tio2 particles was relatively good and only few aggregations exist. The maximum adsorption capacity of petrol and gasoline was obtained in 30 minute. The adsorption rate of gasoline was 6.49±0.10 g/g and oil was 7.01±0.13 g/g. Conclusion: According to the results and in comparison with commercial imported adsorbents, the synthesized Nano-composite had favorable performance. The results show that the polypropylene/Tio2 Nano-composite can be used effectively in light petroleum hydrocarbons removal from polluted water sources.

  15. Conversational Narcissism.

    Science.gov (United States)

    Vangelisti, Anita L.; And Others

    1990-01-01

    Examines narcissistic communication and the ways it is exhibited in everyday conversation. Identifies the following behavioral referents: boasting, refocusing the topic of conversation on the self, exaggerating hand and body movements, using a loud tone of voice, and "glazing over" when others speak. Suggests that conversational…

  16. Contentious Conversations

    Science.gov (United States)

    Zuidema, Leah A.

    2011-01-01

    The idea of joining a conversation through reading and writing is not new; in his 1941 book "The Philosophy of Literary Form: Studies in Symbolic Action," Kenneth Burke suggests that the acts of reading and writing are like entering a parlor where others are already conversing. The author explores the place of professional debate within NCTE and…

  17. Conversion factor and uncertainty estimation for quantification of towed gamma-ray detector measurements in Tohoku coastal waters

    Science.gov (United States)

    Ohnishi, S.; Thornton, B.; Kamada, S.; Hirao, Y.; Ura, T.; Odano, N.

    2016-05-01

    Factors to convert the count rate of a NaI(Tl) scintillation detector to the concentration of radioactive cesium in marine sediments are estimated for a towed gamma-ray detector system. The response of the detector against a unit concentration of radioactive cesium is calculated by Monte Carlo radiation transport simulation considering the vertical profile of radioactive material measured in core samples. The conversion factors are acquired by integrating the contribution of each layer and are normalized by the concentration in the surface sediment layer. At the same time, the uncertainty of the conversion factors are formulated and estimated. The combined standard uncertainty of the radioactive cesium concentration by the towed gamma-ray detector is around 25 percent. The values of uncertainty, often referred to as relative root mean squat errors in other works, between sediment core sampling measurements and towed detector measurements were 16 percent in the investigation made near the Abukuma River mouth and 5.2 percent in Sendai Bay, respectively. Most of the uncertainty is due to interpolation of the conversion factors between core samples and uncertainty of the detector's burial depth. The results of the towed measurements agree well with laboratory analysed sediment samples. Also, the concentrations of radioactive cesium at the intersection of each survey line are consistent. The consistency with sampling results and between different lines' transects demonstrate the availability and reproducibility of towed gamma-ray detector system.

  18. CO2 Capture and Conversion on Rutile TiO2(110) in the Water Environment: Insight by First-Principles Calculations.

    Science.gov (United States)

    Yin, Wen-Jin; Krack, Matthias; Wen, Bo; Ma, Shang-Yi; Liu, Li-Min

    2015-07-02

    The conversion of CO2 by the virtue of sunlight has the great potential to produce useful fuels or valuable chemicals while decreasing CO2 emission from the traditional fossil fuels. Here, we use the first-principles calculations combined with the periodic continuum solvation model (PCSM) to explore the adsorption and reactivity of CO2 on rutile TiO2(110) in the water environment. The results exhibit that both adsorption structures and reactivity of CO2 are greatly affected by water coadsorption on rutile TiO2(110). In particular, the solvation effect can change the most stable adsorption configuration of CO2 and H2O on rutile TiO2(110). In addition, the detailed conversion mechanism of CO2 reduction is further explored in the water environment. The results reveal that the solvation effect cannot only greatly decrease the energy barrier of CO2 reduction but also affect the selectivity of the reaction processes. These results presented here show the importance of the aqueous solution, which should be helpful to understand the detailed reaction processes of photocatalysts.

  19. Modification of Wide-Band-Gap Oxide Semiconductors with Cobalt Hydroxide Nanoclusters for Visible-Light Water Oxidation.

    Science.gov (United States)

    Maeda, Kazuhiko; Ishimaki, Koki; Tokunaga, Yuki; Lu, Daling; Eguchi, Miharu

    2016-07-11

    Cobalt-based compounds, such as cobalt(II) hydroxide, are known to be good catalysts for water oxidation. Herein, we report that such cobalt species can also activate wide-band-gap semiconductors towards visible-light water oxidation. Rutile TiO2 powder, a well-known wide-band-gap semiconductor, was capable of harvesting visible light with wavelengths of up to 850 nm, and thus catalyzed water oxidation to produce molecular oxygen, when decorated with cobalt(II) hydroxide nanoclusters. To the best of our knowledge, this system constitutes the first example that a particulate photocatalytic material that is capable of water oxidation upon excitation by visible light can also operate at such long wavelengths, even when it is based on earth-abundant elements only.

  20. Light induced oxidative water splitting in photosynthesis: energetics, kinetics and mechanism.

    Science.gov (United States)

    Renger, Gernot

    2011-01-01

    The essential steps of photosynthetic water splitting take place in Photosystem II (PSII) and comprise three different reaction sequences: (i) light induced formation of the radical pair P680(+)Q(A)(-), (ii) P680(+) driven oxidative water splitting into O(2) and four protons, and (iii) two step plastoquinone reduction to plastoquinol by Q(A)(-). This mini-review briefly summarizes our state of knowledge on energetics, kinetics and mechanism of oxidative water splitting. Essential features of the two types of reactions involved are described: (a) P680(+) reduction by the redox active tyrosine Y(z) and (b) sequence of oxidation steps induced by Y(z)(ox) in the water-oxidizing complex (WOC). The rate of the former reaction is limited by the non-adiabatic electron transfer (NET) step and the multi-phase kinetics shown to originate from a sequence of relaxation processes. In marked contrast, the rate of the stepwise oxidation by Y(z)(ox) of the WOC up to the redox level S(3) is not limited by NET but by trigger reactions which probably comprise proton shifts and/or conformational changes. The overall rate of the final reaction sequence leading to formation and release of O(2) is assumed to be limited by the electron transfer step from the S(3) state of WOC to Y(z)(ox) due to involvement of an endergonic redox equilibrium. Currently discussed controversial ideas on possible pathways are briefly outlined. Several crucial points of the mechanism of oxidative water splitting, like O-O bond formation, role of local proton shift(s), details of hydrogen bonding, are still not clarified and remain a challenging topic of future research.