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Sample records for sunlight concentration annual

  1. Terrestrial photovoltaic power systems with sunlight concentration. Annual progress report, January 1, 1975--December 31, 1975

    Energy Technology Data Exchange (ETDEWEB)

    Backus, C.E.

    1976-01-31

    This annual report is for the second year of a program to investigate the characteristics of the components and the total system using sunlight concentrated onto solar cells. The second year was primarily to experimentally investigate the conclusions of the first year of analytical studies. Cells have been fabricated that are designed for different intensities. Typically the efficiency of a cell will increase from its 11 percent at AM1 peak to efficiency at the designed concentration level and return to its initial efficiency at about 3 times its designed concentration level. The developed cells have been tested under high intensity simulators and in concentrated sunlight and have shown to have the predicted response. The experimental testing of passive cooling limitations for cooling cells with just finned arrangements in the back of the cell has been completed in the controlled environment of a wind tunnel. These experiments have confirmed the heat transfer coefficients that had been used in the analytical studies. Testing was done to collect heat transfer coefficients for actual wind conditions and these data show good agreement with the controlled wind tunnel data. Four photovoltaic/concentrator system experiments have been started with CR of about 3, 10, 25, and 100. System analysis has indicated that photovoltaic concentration systems may be attractive in low solar irradiation areas such as Cleveland.

  2. Effects of concentrated sunlight on organic photovoltaics

    DEFF Research Database (Denmark)

    Tromholt, Thomas; Katz, Eugene A.; Hirsch, Baruch

    2010-01-01

    gradually from 0.2 to 27 suns. Power conversion efficiency exhibited slow increase with C that was followed by saturation around 2% at C = 0.5–2.5 suns and subsequent strong reduction. Possible OPV applications in stationary solar concentrators (C ≤ 2 suns) are discussed. Finally, experiments at C = 55......We report the effects of concentrated sunlight on key photovoltaic parameters and stability of organic photovoltaics (OPV). Sunlight collected and concentrated outdoors was focused into an optical fiber and delivered onto a 1 cm2 bulk-heterojunction cell. Sunlight concentration C was varied...

  3. Degadation of semiconducting polymers by concentrated sunlight

    DEFF Research Database (Denmark)

    Tromholt, Thomas; Manceau, Matthieu; Petersen, Martin Helgesen

    2011-01-01

    A lens based sunlight concentration setup was used to accelerate the degradation of semiconducting polymers. Sunlight was collected outdoor and focused into an optical fiber bundle allowing for indoor experimental work. Photo-degradation of several polymers was studied by UV–vis absorbance...... spectroscopy and infra-red spectroscopy. This showed that the degradation rate is significantly increased by increasing illumination intensity. Acceleration factors exceeding 100 compared to standard 1 sun illumination were observed for solar concentration of 200 suns in the case of P3HT. A comparison between...

  4. Concentrated sunlight for organic solar cells

    DEFF Research Database (Denmark)

    Tromholt, Thomas

    2010-01-01

    Concentrated sunlight provides a novel approach to the study of the physical and electrical parameters of organic solar cells. The study of performance of organic solar cells at high solar concentrations provides insight into the physics, which cannot be studied with conventional solar simulators....... A high solar intensity study of inverted P3HT:PCBM solar cells is presented. Performance peak positions were found to be in the range of 1-5 suns, with smaller cells peaking at higher solar concentrations. Additionally, concentrated sunlight is demonstrated as a practical tool for accelerated stability...... studies of polymers for organic solar cells. Degradation was monitored by the evolution of the UV-vis absorption over time. Varying the solar intensity from 1 to 200 suns, the degradation rates were increased by more than a factor of 100 relative to degradation at 1 simulated sun. 5 different polymers...

  5. Concentrated sunlight for organic solar cells

    DEFF Research Database (Denmark)

    Tromholt, Thomas

    2010-01-01

    Concentrated sunlight provides a novel approach to the study of the physical and electrical parameters of organic solar cells. The study of performance of organic solar cells at high solar concentrations provides insight into the physics, which cannot be studied with conventional solar simulators...... studies of polymers for organic solar cells. Degradation was monitored by the evolution of the UV-vis absorption over time. Varying the solar intensity from 1 to 200 suns, the degradation rates were increased by more than a factor of 100 relative to degradation at 1 simulated sun. 5 different polymers....... A high solar intensity study of inverted P3HT:PCBM solar cells is presented. Performance peak positions were found to be in the range of 1-5 suns, with smaller cells peaking at higher solar concentrations. Additionally, concentrated sunlight is demonstrated as a practical tool for accelerated stability...

  6. Accelerated stability testing of organic photovoltaics using concentrated sunlight

    DEFF Research Database (Denmark)

    Katz, Eugene A.; Manor, Assaf; Mescheloff, Asaf;

    2012-01-01

    We suggest to use concentrated sunlight for accelerated studies of light-induced mechanisms in the degradation of organic photovoltaics (OPV) based on the polymer (P3HT)/fullerene (PCBM) bulk heterojunctions. Two particular cases of the degradation are reported.......We suggest to use concentrated sunlight for accelerated studies of light-induced mechanisms in the degradation of organic photovoltaics (OPV) based on the polymer (P3HT)/fullerene (PCBM) bulk heterojunctions. Two particular cases of the degradation are reported....

  7. Reversible degradation of inverted organic solar cells by concentrated sunlight

    DEFF Research Database (Denmark)

    Tromholt, Thomas; Manor, Assaf; Katz, Eugene A

    2011-01-01

    Concentrated sunlight was used to study the performance response of inverted P3HT:PCBM organic solar cells after exposure to high intensity sunlight. Correlations of efficiency as a function of solar intensity were established in the range of 0.5–15 suns at three different stages: for a pristine....... The transient state is believed to be a result of the breakdown of the diode behaviour of the ZnO electron transport layer by O2 desorption, increasing the hole conductivity. These results imply that accelerated degradation of organic solar cells by concentrated sunlight is not a straightforward process...... cell, after 30 min exposure at 5 suns and after 30 min of rest in the dark. High intensity exposure introduced a major performance decrease for all solar intensities, followed by a partial recovery of the lost performance over time: at 1 sun only 6% of the initial performance was conserved after...

  8. Novel materials and devices for sunlight concentrating systems

    Science.gov (United States)

    Hovel, H. J.

    1980-09-01

    An economic analysis of photovoltaic conversion under concentrated sunlight has been performed which demonstrates that solar cell efficiency, concentrator efficiency, and concentrator cost are the most important parameters in a concentrating photovoltaic system; solar cell cost is only of secondary importance. Six novel structures are described, including modified conventional Si cells Ga(1-x)Al(x)As/GaAs, interdigitated cells, vertical and horizontal multijunction cells and 'multicolor' devices.

  9. Reversible degradation of inverted organic solar cells by concentrated sunlight

    OpenAIRE

    Tromholt, Thomas; Manor, Assaf; Katz, Eugene A.; Frederik C. Krebs

    2011-01-01

    Concentrated sunlight was used to study the performance response of inverted P3HT:PCBM organic solar cells after exposure to high intensity sunlight. Correlations of efficiency as a function of solar intensity were established in the range of 0.5–15 suns at three different stages: for a pristine cell, after 30 min exposure at 5 suns and after 30 min of rest in the dark. High intensity exposure introduced a major performance decrease for all solar intensities, followed by a partial recovery of...

  10. Reversible degradation of inverted organic solar cells by concentrated sunlight.

    Science.gov (United States)

    Tromholt, Thomas; Manor, Assaf; Katz, Eugene A; Krebs, Frederik C

    2011-06-03

    Concentrated sunlight was used to study the performance response of inverted P3HT:PCBM organic solar cells after exposure to high intensity sunlight. Correlations of efficiency as a function of solar intensity were established in the range of 0.5-15 suns at three different stages: for a pristine cell, after 30 min exposure at 5 suns and after 30 min of rest in the dark. High intensity exposure introduced a major performance decrease for all solar intensities, followed by a partial recovery of the lost performance over time: at 1 sun only 6% of the initial performance was conserved after the high intensity exposure, while after rest the performance had recovered to 60% of the initial value. The timescale of the recovery effect was studied by monitoring the cell performance at 1 sun after high intensity exposure. This showed that cell performance was almost completely restored after 180 min. The transient state is believed to be a result of the breakdown of the diode behaviour of the ZnO electron transport layer by O(2) desorption, increasing the hole conductivity. These results imply that accelerated degradation of organic solar cells by concentrated sunlight is not a straightforward process, and care has to be taken to allow for a sound accelerated lifetime assessment based on concentrated sunlight.

  11. Effect of sunlight exposure on serum 25-hydroxyvitamin d concentration in women with vitamin d deficiency: using ambulatory lux meter and sunlight exposure questionnaire.

    Science.gov (United States)

    Lee, Sang-Hoon; Park, Soo-Jung; Kim, Kwang-Min; Lee, Duck-Joo; Kim, Woo-Jae; Park, Rae-Woong; Joo, Nam-Seok

    2012-11-01

    Vitamin D is an important factor in human health. Yet, vitamin D deficiency is very common. We aimed to confirm serum 25-hydroxyvitamin D (25OHD) concentration change after sunlight exposure and to elucidate the relationship between the amount of sunlight exposure and serum 25OHD level change by ambulatory lux meter and sunlight exposure questionnaire. Twenty healthy young women were enrolled. They were educated to obtain 20 minutes of sunlight exposure during weekdays from October to November, 2010, during which they were to wear an ambulatory lux meter on an arm. All subjects completed a one-week recall sunlight exposure questionnaire at the end of the study. Before and after sunlight exposure, serum 25OHD level was measured. Mean pre-exposure serum 25OHD concentration was 11.01 ng/mL. The mean change of pre- and post-exposure 25OHD level was -0.62 ng/mL, but it was not statistically significant. The mean personal sunlight exposure recorded by ambulatory lux meter, 292.6 lux/s, showed no significant relationship with average change of 25OHD and average weekly sunlight exposure score, 11.9, calculated by the sunlight exposure questionnaire. However, the mean change of serum 25OHD level and weekly sunlight exposure score showed significant negative correlation (r = -0.469, P = 0.037). Change of serum 25OHD concentration after four weeks of sunlight exposure was not statistically significant in women with vitamin D deficiency. However, serum 25OHD concentration change was significantly negatively correlated with the sunlight exposure score by the questionnaire.

  12. Modelling acceptance of sunlight in high and low photovoltaic concentration

    Energy Technology Data Exchange (ETDEWEB)

    Leutz, Ralf, E-mail: ralf.leutz@leopil.com [Leutz Optics and Illumination UG (haftungsbeschränkt), Marburg (Germany)

    2014-09-26

    A simple model incorporating linear radiation characteristics, along with the optical trains and geometrical concentration ratios of solar concentrators is presented with performance examples for optical trains of HCPV, LCPV and benchmark flat-plate PV.

  13. Experimenting with concentrated sunlight using the DLR solar furnace

    Energy Technology Data Exchange (ETDEWEB)

    Neumann, A.; Groer, U. [Deutsche Forschungsanstalt fuer Luft- und Raumfahrt Linder Hoehe, Koeln (Germany)

    1996-10-01

    The high flux solar furnace that is operated by the Deutsche Forschungsanstalt fuer Luft- und Raumfahrt (DLR) at Cologne was inaugurated in June 1994 and we are now able to look back onto one year of successful operation. The solar furnace project was founded by the government of the State Northrhine Westfalia within the Study Group AG Solar. The optical design is a two-stage off-axis configuration which uses a flat 52 m{sup 2} heliostat and a concentrator composed of 147 spherical mirror facets. The heliostat redirects the solar light onto the concentrator which focuses the beam out of the optical axis of the system into the laboratory building. At high insolation levels (>800W/m{sup 2}) it is possible to collect a total power of 20 kW with peak flux densities of 4 MW/m{sup 2}. Sixteen different experiment campaigns were carried out during this first year of operation. The main research fields for these experiments were material science, component development and solar chemistry. The furnace also has its own research program leading to develop sophisticated measurement techniques like remote infrared temperature sensing and flux mapping. Another future goal to be realized within the next five years is the improvement of the performance of the furnace itself. 6 refs., 9 figs., 1 tab.

  14. Reversible degradation in ITO-containing organic photovoltaics under concentrated sunlight

    NARCIS (Netherlands)

    Galagan, Y.O.; Mescheloff, A.; Veenstra, S.C.; Andriessen, H.A.J.M.; Katz, E.A.

    2015-01-01

    Stabilities of ITO-containing and ITO-free organic solar cells were investigated under simulated AM 1.5G illumination and under concentrated natural sunlight. In both cases ITO-free devices exhibit high stability, while devices containing ITO show degradation of their photovoltaic performance. The a

  15. Formation of Silicon Carbide Using Volcanic Ash as Starting Material and Concentrated Sunlight as Energy Resource

    Directory of Open Access Journals (Sweden)

    Kensuke Nishioka

    2015-01-01

    Full Text Available SiC was formed using volcanic ash as starting material and concentrated sunlight as energy resource. The solar furnace was composed of two parts: Fresnel lens and reacting furnace. The reacting furnace was composed of a cylindrical vacuum chamber and quartz glass plate functioning to guide the concentrated sunlight into the furnace and was placed at the focal point of the Fresnel lens. The sample was made from the mixture of silica formed from volcanic ash and graphite and placed in the carbon crucible inside the reacting furnace. The temperature in the carbon crucible reached more than 1500°C. After the reaction using concentrated light, β-SiC was formed. The weight % of formed SiC was 90.5%.

  16. Power Output Improvement of PV Module for Agricultural Use by Using Inexpensive Sunlight Concentrator

    Institute of Scientific and Technical Information of China (English)

    NISHIMURA Ryo

    2010-01-01

    PV modules are used as stand alone power sources for agricultural equipments such as lifting pumps in farms,where the power infrastructure is not yet improved.In order to expand the agricultural use of PV module,the cost of PV generation should be reduced.In this paper,the power output performance of a commercial PV module was improved by using a sunlight concentrator that could be assembled inexpensively and a simple sun-tracking method.

  17. Rapid synthesis of nanocrystalline magnesium chromite and ferrite ceramics with concentrated sunlight

    Energy Technology Data Exchange (ETDEWEB)

    Michalsky, Ronald, E-mail: michalskyr@ethz.ch; Peterson, Brian A.; Pfromm, Peter H.

    2014-04-01

    Highlights: • Refractory ceramics are produced via rapid solar-thermal processing. • The formed chromite and ferrite spinels have a high specific surface area. • The presence of transition metal oxides enables reduction of Mg cations. • Dinitrogen is reduced only by chromium. • The spinels are stable in reducing environments and in the presence of solar radiation. - Abstract: High-temperature refractory ceramics and catalysts such as MgM{sub 2}O{sub 4} (M = Cr, Fe) are produced conventionally via energy-intensive solid-state syntheses (using 0.44–10 GJ electricity for sintering per ton oxide, equivalent to combustion of 48–1088 kg coal per ton oxide). This article reports rapid production of 17 ± 2 mol% MgFe{sub 2}O{sub 4} and 8.6 ± 0.9 mol% MgCr{sub 2}O{sub 4} after 30 min at 1200 °C employing 0.82 kW m{sup −2} sunlight concentrated at a geometric ratio of about 900 m{sup 2} m{sup −2} using a Fresnel lens. Solar radiation promotes the diffusion-limited ferrite formation (42 ± 5 μmol MgFe{sub 2}O{sub 4} per mol Fe{sub 2}O{sub 3} s{sup −1} vs. 26 ± 3 μmol mol{sup −1} s{sup −1} in absence of sunlight) while the transition metals promote the reduction of Mg{sup 2+}. The nanocrystalline and macroporous spinel has a specific surface area of 9.7–11.9 m{sup 2} g{sup −1} (in the order of sol–gel synthesis methods) and is stable under extreme conditions, i.e., high temperature, solar radiation, and reducing agents.

  18. 2011 NATA - Risks and Annual Ambient Concentrations

    Data.gov (United States)

    U.S. Environmental Protection Agency — This dataset includes the modeled annual ambient concentrations and risks at the census tract level for the 2011 National Air Toxics Assessment. All concentrations...

  19. A simple relationship between the sunlight concentration factor and the thermal conductance in a class of photothermal engines

    Energy Technology Data Exchange (ETDEWEB)

    Rocha-Martinez, J.A.; Navarrete-Gonzalez, T.D. [Area de Fisica, Dept. de Ciencias Basicas, Universidad Autonoma Metropolitana Azcapotzalco, Mexico (Mexico); Angulo-Brown, F. [Departaamento de Fisica, Escuela Superior de Fisica y Matematicas, Instituto Politecnico Nacional, Mexico (Mexico)

    1998-07-21

    In this brief paper we present an addendum to a recently published analysis of a photothermal engine model. Here, we numerically demonstrate that the design parameters, the sunlight concentration factor and the thermal conductances of materials employed as thermal conductors are linked by a simple relationship, if one wishes to obtain the maximization of the power output of the photothermal engine. (author)

  20. Test of a device for accelerated ageing of polymeric material in high concentrated sunlight at the DLR solar furnace

    Energy Technology Data Exchange (ETDEWEB)

    Witzke, A.; Neumann, A.; Kaluza, J. [German Aerospace Center (DLR), Solar Energy Technology, Cologne (Germany); Demuth, M.; Ritterskamp, P. [Max-Planck-Inst. fuer Strahlenchemie, Muelheim a.d.R. (Germany)

    2001-07-01

    Within this study the design and first tests of a device for accelerated ageing with high concentrated sunlight have been described. Firstly, the device was designed for testing samples of lacquer for the car industry. It is based on two points: first, the photochemical effect that the ageing of polymers is mainly initiated by the UV solar radiation and, second, on the idea to accelerate the ageing process by increasing the UV radiation dose. Therefore the concentrated sunlight at the DLR Solar Furnace is filtered by a cold-mirror that reflects the radiation with a wavelength below 450 nm onto the samples. The samples are fixed in a chamber where they can simultaneously be wetted by a spraying device. The first tests show that this device enables us to radiate the relevant samples with a high UV radiation intensity without overheating them. During one day irradiation at the DLR Solar Furnace in March 2001 we reach an UV radiation dose which is about sixteen times higher than the dose after 24 hours irradiation in common used weathering devices. Further tests at the DLR Solar Furnace have to examine in what way this increased radiation dose leads to a high accelerated ageing of the polymeric material. (orig.)

  1. Sunlight to hydrogen conversion: Design optimization and energy management of concentrated photovoltaic (CPV-Hydrogen) system using micro genetic algorithm

    KAUST Repository

    Burhan, Muhammad

    2016-02-14

    Owing to the intermittent solar irradiance from cloud cover in the diurnal period and unavailability at night time, the practical design of a solar system requires energy backup storage for an uninterrupted supply or for off-grid operation. However, for highly efficient CPV (concentrated photovoltaic) system, the literature is lacking for energy management and optimization algorithm and tool for standalone operation. In this paper, a system with CPV and electrolyser is presented where beam irradiance of sunlight is harnessed to convert the instantaneously generated electricity into useful Hydrogen/Oxygen gas, where they can be stored and re-used for downstream applications such as the fuel cells, etc. The multi-variable design and multi-objective optimization strategies are proposed and presented for a standalone operation of the CPV-Hydrogen system as well as their system performances, particularly electrical rating of CPV based upon the real weather data of Singapore. © 2016 Elsevier Ltd.

  2. Determination of optimum sunlight concentration level in space for 3-4 cascade solar cells

    Science.gov (United States)

    Curtis, H. B.

    1982-01-01

    The optimum range of concentration in space for III-V cascade cells has been calculated using a realistic solar cell diode equation. Temperature was varied with concentration using several models and ranged from 55 deg at one sun to between 80 deg and 200 deg C at 100 suns. A variety of series resistance and internal resistances were used. Coefficients of the diffusion and recombination terms are strongly temperature dependent. The study indicates that the maximum efficiency of 30 percent occurs in the 50 to 100 X sun concentration range provided series resistance is below 0.015 ohm sq cm and cell temperature is about 80 C at 100 suns.

  3. Determination of optimum sunlight concentration level in space for 3-5 cascade solar cells

    Science.gov (United States)

    Curtis, H. B.

    1982-01-01

    The optimum range of concentration levels in space for III-V cascade cells was calculated using a realistic solar cell diode equation. Temperature was varied with concentration using several models and ranged from 55 C at 1 sun to between 80 and 200 C at 100 suns. A variety of series resistance and internal resistances were used. Coefficients of the diffusion and recombination terms are strongly temperature dependent. The study indicates that the maximum efficiency of 30 percent occurs in the 50 to 100 sun concentration range provided series resistance is below 0.015 ohm-sq cm and cell temperature is about 80 C at 100 suns.

  4. Use of Uniformly Distributed Concentrated Sunlight for Highly Accelerated Testing of Coatings

    Energy Technology Data Exchange (ETDEWEB)

    Jorgensen, G.; Bingham, C.; King, D.; Lewandowski, A.; Netter, J.; Terwilliger, K.; Adamsons, K.

    2000-12-14

    NREL has developed a new ultraviolet (UV) light concentrator that allows material samples to be subjected to uniform intensity levels of 50-100X solar UV at closely controlled sample exposure temperatures. In collaboration with industry, representative coating systems have been exposed without introducing unrealistic degradation mechanisms. Furthermore, correlations have been derived between these highly accelerated test conditions and results obtained at 1-2 suns. Such information is used to predict the degradation of materials in real-world applications. These predictions are compared with measured in-service performance losses to validate the approach. This allows valuable information to be obtained in greatly reduced timeframes, which can provide tremendous competitive advantage in the commercial marketplace.

  5. Lateral current effects on the voltage distribution in the emitter of solar cells under concentrated sunlight

    Energy Technology Data Exchange (ETDEWEB)

    Morales-Acevedo, Arturo [CINVESTAV-IPN, Electrical Engineering Department, Avenida IPN No. 2508, 07360 Mexico, DF (Mexico)

    2009-04-15

    The design of the grid contact in silicon solar cells is one of the most important steps for the optimization and fabrication of these energy conversion devices. The voltage drop due to the lateral flow of current towards the grid fingers can be a limiting factor causing the reduction of conversion efficiency. For low current levels this voltage drop can be made small, for typical values of sheet resistance in the emitter, but for solar cells made to operate at high sun concentrations this efficiency loss can be important, unless there is a clear vision of the current and voltage distribution so that the emitter and grid design can be improved. Hence, it is important to establish and solve the current and voltage distribution equations for solar cells with a grid contact. In this work, first these equations are established and then they are solved in order to show the effects that the lateral current flow in the emitter cause on the voltage distribution, particularly at high illumination levels. In addition, it will be shown that the open circuit voltage is significantly reduced due to the lateral current flow as compared to the value predicted from a simple equivalent circuit with a lumped resistance model. (author)

  6. Annual energy yield of the fluorescent solar concentrator

    Energy Technology Data Exchange (ETDEWEB)

    Van Sark, W.G.J.H.M.; Hellenbrand, G.F.M.G. [Department of Science, Technology and Society, Copernicus Institute for Sustainable Development and Innovation, Utrecht University, Heidelberglaan 2, 3584 CS Utrecht (Netherlands); Bende, E.E.; Burgers, A.R.; Slooff, L.H. [ECN Solar Energy, P.O. Box 1, 1755 ZG Petten (Netherlands)

    2008-09-15

    Fluorescent solar concentrators are but one candidate for lowering the costs of photovoltaic technology. State-of-the-art device conversion efficiencies are around 4%, and the device configuration can be optimized in terms of Euro per Watt. This paper aims to estimate the annual energy yield of such an optimized device configuration, using a detailed minutely spectral irradiance data set, describing a full year in the Netherlands, in combination with a ray-tracing model of the fluorescent solar concentrator. The spectral dataset is modeled using experimentally determined global, direct, and diffuse irradiation data on a minutely basis. Performance variations during the day for a number of typical days are investigated, i.e., for a clear summer day, a cloudy summer day, a clear winter day, and a cloudy winter day, using a ray-trace model of the fluorescent solar concentrator. Also, monthly aggregated spectra are used, as well as an annually aggregated spectrum to determine monthly and annual energy yields, respectively. As a result of a cost-per-unit-of-power optimization study, an optimum size of 23x23x0.1 cm{sup 3} was used, and an annual energy yield of 41.3 kWh/m{sup 2} could be estimated; this is 4.7 times lower than the annual energy yield of a state-of-the-art silicon solar cell.

  7. Weekday sunlight exposure, but not vitamin D intake, influences the association between vitamin D receptor genotype and circulating concentration 25-hydroxyvitamin D in a pan-European population: the Food4Me study.

    Science.gov (United States)

    Livingstone, Katherine M; Celis-Morales, Carlos; Hoeller, Ulrich; Lambrinou, Christina P; Moschonis, George; Macready, Anna L; Fallaize, Rosalind; Baur, Manuela; Roos, Franz F; Bendik, Igor; Grimaldi, Keith; Navas-Carretero, Santiago; San-Cristobal, Rodrigo; Weber, Peter; Drevon, Christian A; Manios, Yannis; Traczyk, Iwona; Gibney, Eileen R; Lovegrove, Julie A; Saris, Wim H; Daniel, Hannelore; Gibney, Mike; Martinez, J Alfredo; Brennan, Lorraine; Hill, Tom R; Mathers, John C

    2017-02-01

    Little is known about diet- and environment-gene interactions on 25-hydroxyvitamin D (25(OH)D concentration. This cross-sectional study aimed to investigate (i) predictors of 25(OH)D concentration and relationships with vitamin D genotypes and (ii) whether dietary vitamin D intake and sunlight exposure modified these relationships. Participants from the Food4Me study (n = 1312; age 18-79) were genotyped for vitamin D receptor (VDR) and vitamin D binding protein at baseline and a genetic risk score was calculated. Dried blood spot samples were assayed for 25(OH)D concentration and dietary and lifestyle information collected. Circulating 25(OH)D concentration was lower with increasing genetic risk score, lower in females than males, higher in supplement users than non-users and higher in summer than winter. Carriage of the minor VDR allele was associated with lower 25(OH)D concentration in participants with the least sunlight exposure. Vitamin D genotype did not influence the relationship between vitamin D intake and 25(OH)D concentration. Age, sex, dietary vitamin D intake, country, sunlight exposure, season, and vitamin D genetic risk score were associated with circulating 25(OH)D concentration in a pan-European population. The relationship between VDR genotype and 25(OH)D concentration may be influenced by weekday sunlight exposure but not dietary vitamin D intake. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Watershed Regressions for Pesticides (WARP) for Predicting Annual Maximum and Annual Maximum Moving-Average Concentrations of Atrazine in Streams

    Science.gov (United States)

    Stone, Wesley W.; Gilliom, Robert J.; Crawford, Charles G.

    2008-01-01

    Regression models were developed for predicting annual maximum and selected annual maximum moving-average concentrations of atrazine in streams using the Watershed Regressions for Pesticides (WARP) methodology developed by the National Water-Quality Assessment Program (NAWQA) of the U.S. Geological Survey (USGS). The current effort builds on the original WARP models, which were based on the annual mean and selected percentiles of the annual frequency distribution of atrazine concentrations. Estimates of annual maximum and annual maximum moving-average concentrations for selected durations are needed to characterize the levels of atrazine and other pesticides for comparison to specific water-quality benchmarks for evaluation of potential concerns regarding human health or aquatic life. Separate regression models were derived for the annual maximum and annual maximum 21-day, 60-day, and 90-day moving-average concentrations. Development of the regression models used the same explanatory variables, transformations, model development data, model validation data, and regression methods as those used in the original development of WARP. The models accounted for 72 to 75 percent of the variability in the concentration statistics among the 112 sampling sites used for model development. Predicted concentration statistics from the four models were within a factor of 10 of the observed concentration statistics for most of the model development and validation sites. Overall, performance of the models for the development and validation sites supports the application of the WARP models for predicting annual maximum and selected annual maximum moving-average atrazine concentration in streams and provides a framework to interpret the predictions in terms of uncertainty. For streams with inadequate direct measurements of atrazine concentrations, the WARP model predictions for the annual maximum and the annual maximum moving-average atrazine concentrations can be used to characterize

  9. Analytical modelling and experimental verification of the three-dimensional current distribution on the top surface of silicon solar cells operating under concentrated sunlight

    Energy Technology Data Exchange (ETDEWEB)

    Costagliola, Maurizio; Riccio, Michele; Irace, Andrea; Breglio, Gianluca; Daliento, Santolo [Department of Biomedical, Electronics and Telecommunications Engineering, University of Naples ' ' Federico II' ' , via Claudio 21, 80125 Naples (Italy)

    2011-03-15

    The approximation that the current is constant in any point of the emitter is not true for solar cells operating under concentrated sunlight. The transverse paths followed by photogenerated carriers to reach metal grid electrodes causes voltage drops leading to non-uniform distributed surface potential and a consequent reduction of the conversion efficiency. Moreover, concentrating lens often provide non-uniform light intensity thus worsening non-uniform current distribution. The correct design of surface geometry of the cell (metal grid, emitter depth, sheet resistance) should always take into account the above effects. Unfortunately a lack of reliable models still exists. In this paper we analytically solve the three-dimensional semiconductor equations with proper boundary conditions and taking into account, as source term, a distributed generation contribute. The reliability of the model has been tested by numerical simulations and experimentally verified with a lock-in thermography technique (copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  10. Taxicab tipping and sunlight

    Science.gov (United States)

    2017-01-01

    Does the level of sunlight affect the tipping percentage in taxicab rides in New York City? We examined this question using data on 13.82 million cab rides from January to October in 2009 in New York City combined with data on hourly levels of solar radiation. We found a small but statistically significant positive relationship between sunlight and tipping, with an estimated tipping increase of 0.5 to 0.7 percentage points when transitioning from a dark sky to full sunshine. The findings are robust to two-way clustering of standard errors based on hour-of-the-day and day-of-the-year and controlling for day-of-the-year, month-of-the-year, cab driver fixed effects, weather conditions, and ride characteristics. The NYC cab ride context is suitable for testing the association between sunlight and tipping due to the largely random assignment of riders to drivers, direct exposure to sunlight, and low confounding from variation in service experiences. PMID:28594917

  11. Annual variations of atmospheric VOC concentrations in a boreal forest

    Energy Technology Data Exchange (ETDEWEB)

    Hakola, H.; Hellen, H.; Tarvainen, V. (Finnish Meteorological Institute Air Quality Research, Helsinki (Finland)); Baeck, J. (Dept. of Forest Ecology, Univ. of Helsinki (Finland)); Patokoski, J.; Rinne, J. (Dept. of Physics, Univ. of Helsinki (Finland))

    2009-07-01

    Ambient atmospheric concentrations of monoterpene compounds were measured above a boreal forest in Hyytiaelae, Finland during 2000-2007. For most of the time, two samples per week were collected, although there are some gaps in the data due to analytical or other issues. The monoterpene concentrations reached their maximum in summer, although they were found to be quite high also during winter. The main compounds found during winter were alpha-pinene, DELTA3-carene, beta-pinene and camphene. In summer 1,8-cineol and sabinene were also present in the samples. The concentrations of alpha-pinene, beta-pinene/myrcene, camphene, DELTA3-carene increased during the measurement period both in winter and in summer. This increase cannot be explained by meteorological conditions. The possible explanations could be human activities in the vicinity of the sampling site in addition to forest growth. The seasonal cycles of daytime concentrations were found to follow emission fluxes modeled using a simple temperature dependent parameterisation. The measured monoterpene concentrations were used, together with emission rate measurements, for estimating ambient atmospheric beta-caryophyllene concentration which cannot be directly measured due to its high reactivity against ozone. (orig.)

  12. Ultra-accelerated natural sunlight exposure testing

    Energy Technology Data Exchange (ETDEWEB)

    Jorgensen, G.J.; Bingham, C.; Goggin, R.; Lewandowski, A.A.; Netter, J.C.

    2000-06-13

    Process and apparatus are disclosed for providing ultra accelerated natural sunlight exposure testing of samples under controlled weathering without introducing unrealistic failure mechanisms in exposed materials and without breaking reciprocity relationships between flux exposure levels and cumulative dose that includes multiple concurrent levels of temperature and relative humidity at high levels of natural sunlight comprising: (a) concentrating solar flux uniformly; (b) directing the controlled uniform sunlight onto sample materials in a chamber enclosing multiple concurrent levels of temperature and relative humidity to allow the sample materials to be subjected to accelerated irradiance exposure factors for a sufficient period of time in days to provide a corresponding time of about at least a years worth of representative weathering of the sample materials.

  13. Ultra-accelerated natural sunlight exposure testing

    Energy Technology Data Exchange (ETDEWEB)

    Jorgensen, Gary J. (Pine, CO); Bingham, Carl (Lakewood, CO); Goggin, Rita (Englewood, CO); Lewandowski, Allan A. (Evergreen, CO); Netter, Judy C. (Westminster, CO)

    2000-06-13

    Process and apparatus for providing ultra accelerated natural sunlight exposure testing of samples under controlled weathering without introducing unrealistic failure mechanisms in exposed materials and without breaking reciprocity relationships between flux exposure levels and cumulative dose that includes multiple concurrent levels of temperature and relative humidity at high levels of natural sunlight comprising: a) concentrating solar flux uniformly; b) directing the controlled uniform sunlight onto sample materials in a chamber enclosing multiple concurrent levels of temperature and relative humidity to allow the sample materials to be subjected to accelerated irradiance exposure factors for a sufficient period of time in days to provide a corresponding time of about at least a years worth of representative weathering of the sample materials.

  14. Sunlight-Induced Coloration of Silk

    Science.gov (United States)

    Yao, Ya; Tang, Bin; Chen, Wu; Sun, Lu; Wang, Xungai

    2016-06-01

    Silk fabrics were colored by gold nanoparticles (NPs) that were in situ synthesized through the induction of sunlight. Owing to the localized surface plasmon resonance (LSPR) of gold NPs, the treated silk fabrics presented vivid colors. The photo-induced synthesis of gold NPs was also realized on wet silk through adsorbing gold ions out of solution, which provides a water-saving coloration method for textiles. Besides, the patterning of silk was feasible using this simple sunlight-induced coloration approach. The key factors of coloration including gold ion concentration, pH value, and irradiation time were investigated. Moreover, it was demonstrated that either ultraviolet (UV) light or visible light could induce the generation of gold NPs on silk fabrics. The silk fabrics with gold NPs exhibited high light resistance including great UV-blocking property and excellent fastness to sunlight.

  15. Variation in the annual average radon concentration measured in homes in Mesa County, Colorado

    Energy Technology Data Exchange (ETDEWEB)

    Rood, A.S.; George, J.L.; Langner, G.H. Jr.

    1990-04-01

    The purpose of this study is to examine the variability in the annual average indoor radon concentration. The TMC has been collecting annual average radon data for the past 5 years in 33 residential structures in Mesa County, Colorado. This report is an interim report that presents the data collected up to the present. Currently, the plans are to continue this study in the future. 62 refs., 3 figs., 12 tabs.

  16. An investigation of the potential causes for the seasonal and annual variations in indoor radon concentrations.

    Science.gov (United States)

    Barazza, F; Gfeller, W; Palacios, M; Murith, C

    2015-11-01

    Indoor radon concentrations exhibit strong variations on short and long timescales. Besides human influences, meteorological factors significantly affect the radon concentrations indoors as well as outdoors. In this article, long-term measurements showing strong annual variations are presented, which take a very similar course in different buildings located in largely separated regions in Switzerland. Also, seasonal variations can be very significant. In general, variations in indoor radon levels can primarily be attributed to human influences. On the other hand, specific weather conditions can have a significant impact on indoor radon levels. In order to further investigate the connection between indoor radon levels and meteorological factors, a measuring campaign has been started in two buildings located in two different regions in Switzerland exhibiting different climatic characteristics. Preliminary results of these investigations are presented, which provide evidence for correlations between indoor radon levels and in particular outdoor temperatures, contributing to seasonal and annual as well as short-term variations in indoor radon concentrations.

  17. Luz natural e concentrações de sacarose no cultivo in vitro de Cattleya walkeriana Sunlight and sucrose concentrations on in vitro culture of Cattleya walkeriana

    Directory of Open Access Journals (Sweden)

    Samantha Léa Dignart

    2009-06-01

    were tested: light (standard growth chamber, greenhouse with 50% shading, and greenhouse without shading and sucrose concentrations (0, 15, and 30g.L-1. The material was composed by plantlets previously germinated in vitro on MS medium and cultivated in a growth chamber for 90 days. Natural light in greenhouse induced an increase in the number of shoots, leaf thickness, stomata frequency and diameter and, on the other hand, caused decrease in the plantlet length and chlorophyll levels. Lower number of roots and shoots were formed at the concentration of 15g.L-1 sucrose. The absence of sucrose resulted in lower chlorophyll levels. Based on these results, it was possible to conclude that the cultivation environment modifies the response of in vitro cultivated plantlets and the natural light and reduction of sucrose concentrations by half can be recommend for the micropropagation of Cattleya walkeriana, taking in consideration the propagation phases and their goals.

  18. Assessment of Concentration and the Annual Effective Dose of Radon Gas in Imam Hospital Indoor Air

    Directory of Open Access Journals (Sweden)

    Kobra Verijkazemi

    2016-09-01

    Full Text Available Introduction and purpose: Exposure to natural sources of radiation, especially radon and its short-term products, is an important issue around the world. Radon exposure causes lung cancer in humans. Therefore, the aim of this study was to measure the concentration of radon gas and its annual effective dose in Imam Hospital of Tehran, Iran and to compare its concentrations with the recommended standards. Methods: Radon levels and meteorological parameters (temperature, pressure, and moisture were measured in different levels and in four seasons, using Radstar and Lutron Electronic devices, respectively, during June 2014-June 2015. The collected data were analyzed through SPSS 18. Annual effective dose was calculated, using the equation for annual effective dose introduced by Scientific Committee of the United Nations. Results: The highest concentration of radon and annual effective dose were observed in the winter, which were 82/15 Bq/m3 and0/48 ms/y, respectively. Furthermore, concerning the various levels, the highest concentration was observed in the lowest level (56/1 Bq/m3.Conclusion: The results of the current study demonstrated that radon concentration was lower than the standards set by Environmental Protection Agency and World Health Organization. Regarding this, there are not concerns about the possible dangers of radon gas activities for the personnel and patients of the hospital. 

  19. Sunlight and Vitamin D

    Science.gov (United States)

    Wacker, Matthias; Holick, Michael F.

    2013-01-01

    Vitamin D is the sunshine vitamin that has been produced on this earth for more than 500 million years. During exposure to sunlight 7-dehydrocholesterol in the skin absorbs UV B radiation and is converted to previtamin D3 which in turn isomerizes into vitamin D3. Previtamin D3 and vitamin D3 also absorb UV B radiation and are converted into a variety of photoproducts some of which have unique biologic properties. Sun induced vitamin D synthesis is greatly influenced by season, time of day, latitude, altitude, air pollution, skin pigmentation, sunscreen use, passing through glass and plastic, and aging. Vitamin D is metabolized sequentially in the liver and kidneys into 25-hydroxyvitamin D which is a major circulating form and 1,25-dihydroxyvitamin D which is the biologically active form respectively. 1,25-dihydroxyvitamin D plays an important role in regulating calcium and phosphate metabolism for maintenance of metabolic functions and for skeletal health. Most cells and organs in the body have a vitamin D receptor and many cells and organs are able to produce 1,25-dihydroxyvitamin D. As a result 1,25-dihydroxyvitamin D influences a large number of biologic pathways which may help explain association studies relating vitamin D deficiency and living at higher latitudes with increased risk for many chronic diseases including autoimmune diseases, some cancers, cardiovascular disease, infectious disease, schizophrenia and type 2 diabetes. A three-part strategy of increasing food fortification programs with vitamin D, sensible sun exposure recommendations and encouraging ingestion of a vitamin D supplement when needed should be implemented to prevent global vitamin D deficiency and its negative health consequences. PMID:24494042

  20. Correction factors for determination of annual average radon concentration in dwellings of Poland resulting from seasonal variability of indoor radon

    Energy Technology Data Exchange (ETDEWEB)

    Kozak, K., E-mail: Krzysztof.Kozak@ifj.edu.pl [Institute of Nuclear Physics PAN, Radzikowskiego 152, 31-342 Krakow (Poland); Mazur, J. [Institute of Nuclear Physics PAN, Radzikowskiego 152, 31-342 Krakow (Poland); KozLowska, B. [University of Silesia, Bankowa 12, 40-007 Katowice (Poland); Karpinska, M. [Medical University of Bialystok, Jana Kilinskiego 1, 15-089 BiaLystok (Poland); Przylibski, T.A. [WrocLaw University of Technology, Wybrzeze S. Wyspianskiego 27, 50-370 WrocLaw (Poland); Mamont-Ciesla, K. [Central Laboratory for Radiological Protection, Konwaliowa 7, 03-194 Warszawa (Poland); Grzadziel, D. [Institute of Nuclear Physics PAN, Radzikowskiego 152, 31-342 Krakow (Poland); Stawarz, O. [Central Laboratory for Radiological Protection, Konwaliowa 7, 03-194 Warszawa (Poland); Wysocka, M. [Central Mining Institute, Plac Gwarkow1, 40-166 Katowice (Poland); Dorda, J. [University of Silesia, Bankowa 12, 40-007 Katowice (Poland); Zebrowski, A. [WrocLaw University of Technology, Wybrzeze S. Wyspianskiego 27, 50-370 WrocLaw (Poland); Olszewski, J. [Nofer Institute of Occupational Medicine, Sw.Teresy od Dzieciatka Jezus 8, 91-348 lodz (Poland); Hovhannisyan, H. [Institute of Nuclear Physics PAN, Radzikowskiego 152, 31-342 Krakow (Poland); Dohojda, M. [Institute of Building Technology (ITB), Filtrowa 1, 00-611 Warszawa (Poland); KapaLa, J. [Medical University of Bialystok, Jana Kilinskiego 1, 15-089 BiaLystok (Poland); Chmielewska, I. [Central Mining Institute, Plac Gwarkow1, 40-166 Katowice (Poland); KLos, B. [University of Silesia, Bankowa 12, 40-007 Katowice (Poland); Jankowski, J. [Nofer Institute of Occupational Medicine, Sw.Teresy od Dzieciatka Jezus 8, 91-348 lodz (Poland); Mnich, S. [Medical University of Bialystok, Jana Kilinskiego 1, 15-089 BiaLystok (Poland); KoLodziej, R. [Central Mining Institute, Plac Gwarkow1, 40-166 Katowice (Poland)

    2011-10-15

    The method for the calculation of correction factors is presented, which can be used for the assessment of the mean annual radon concentration on the basis of 1-month or 3-month indoor measurements. Annual radon concentration is an essential value for the determination of the annual dose due to radon inhalation. The measurements have been carried out in 132 houses in Poland over a period of one year. The passive method of track detectors with CR-39 foil was applied. Four thermal-precipitation regions in Poland were established and correction factors were calculated for each region, separately for houses with and without basements. - Highlights: > Using radon concentration results in houses we calculated the correction factors. > Factors were calculated for each month, 2 house types in different regions in Poland. > They enable the evaluation of average annual radon concentration in the house. > Annual average radon concentration basing on 1 or 3 months detector exposure.

  1. Childhood cancer incidence in relation to sunlight exposure.

    Science.gov (United States)

    Musselman, J R B; Spector, L G

    2011-01-04

    There is increasing interest in the possible association between cancer incidence and vitamin D through its role as a regulator of cell growth and differentiation. Epidemiological studies in adults and one paediatric study suggest an inverse association between sunlight exposure and cancer incidence. We carried out an ecological study using childhood cancer registry data and two population-level surrogates of sunlight exposure, (1) latitude of the registry city or population centroid of the registry nation and (2) annual solar radiation. All models were adjusted for nation-level socioeconomic status using socioeconomic indicators. Latitude and radiation were significantly associated with cancer incidence, and the direction of association was consistent between the surrogates. Findings were not consistent across tumour types. Our ecological study offers some evidence to support an association between sunlight exposure and risk of childhood cancer.

  2. Organosulfates and organic acids in Arctic aerosols: speciation, annual variation and concentration levels

    Directory of Open Access Journals (Sweden)

    A. M. K. Hansen

    2014-02-01

    Full Text Available Sources, composition and occurrence of secondary organic aerosols (SOA in the Arctic were investigated at Zeppelin Mountain, Svalbard, and Station Nord, northeast Greenland, during the full annual cycle of 2008 and 2010 respectively. We focused on the speciation of three types of SOA tracers: organic acids, organosulfates and nitrooxy organosulfates from both anthropogenic and biogenic precursors, here presenting organosulfate concentrations and compositions during a full annual cycle and chemical speciation of organosulfates in Arctic aerosols for the first time. Aerosol samples were analysed using High Performance Liquid Chromatography coupled to a quadrupole Time-of-Flight mass spectrometer (HPLC-q-TOF-MS. A total of 11 organic acids (terpenylic acid, benzoic acid, phthalic acid, pinic acid, suberic acid, azelaic acid, adipic acid, pimelic acid, pinonic acid, diaterpenylic acid acetate (DTAA and 3-methyl-1,2,3-butanetricarboxylic acid (MBTCA, 12 organosulfates and one nitrooxy organosulfate were identified at the two sites. Six out of the 12 organosulfates are reported for the first time. Concentrations of organosulfates follow a distinct annual pattern at Station Nord, where high concentration were observed in late winter and early spring, with a mean total concentration of 47 (±14 ng m−3, accounting for 7 (±2% of total organic matter, contrary to a considerably lower organosulfate mean concentration of 2 (±3 ng m−3 (accounting for 1 (±1% of total organic matter observed during the rest of the year. The organic acids followed the same temporal trend as the organosulfates at Station Nord; however the variations in organic acid concentrations were less pronounced, with a total mean organic acid concentration of 11.5 (±4 ng m−3 (accounting for 1.7 (±0.6% of total organic matter in late winter and early spring, and 2.2 (±1 ng m−3 (accounting for 0.9 (±0.4% of total organic matter during the rest of the year. At Zeppelin Mountain

  3. Correction factors for determination of annual average radon concentration in dwellings of Poland resulting from seasonal variability of indoor radon.

    Science.gov (United States)

    Kozak, K; Mazur, J; Kozłowska, B; Karpińska, M; Przylibski, T A; Mamont-Cieśla, K; Grządziel, D; Stawarz, O; Wysocka, M; Dorda, J; Zebrowski, A; Olszewski, J; Hovhannisyan, H; Dohojda, M; Kapała, J; Chmielewska, I; Kłos, B; Jankowski, J; Mnich, S; Kołodziej, R

    2011-10-01

    The method for the calculation of correction factors is presented, which can be used for the assessment of the mean annual radon concentration on the basis of 1-month or 3-month indoor measurements. Annual radon concentration is an essential value for the determination of the annual dose due to radon inhalation. The measurements have been carried out in 132 houses in Poland over a period of one year. The passive method of track detectors with CR-39 foil was applied. Four thermal-precipitation regions in Poland were established and correction factors were calculated for each region, separately for houses with and without basements.

  4. Photocatalytic oxidation of ciprofloxacin under simulated sunlight.

    Science.gov (United States)

    Gad-Allah, Tarek A; Ali, Mohamed E M; Badawy, Mohamed I

    2011-02-15

    Ciprofloxacin (CIP) is a famous synthetic chemotherapeutic antibiotic. It is widely found either in water or wastewater. In this study ciprofloxacin was photocatalytically degraded using commercial anatase titanium dioxide (TiO(2)) under simulated sunlight. The rate of reaction was found to be affected by pH, TiO(2) concentration and antibiotic concentration. The best reaction rate was obtained in natural ciprofloxacin pH (5.8) and 1000 mg/L TiO(2). More titania concentration was found to reduce the reaction rate because of the limitation in light transmittance. From kinetic studies, the reaction was proved to proceed through adsorption step then photooxidation and obeys pseudo-first order kinetics. Copyright © 2010 Elsevier B.V. All rights reserved.

  5. Sunlight Responsive Thermochromic Window System

    Energy Technology Data Exchange (ETDEWEB)

    Millett, F,A; Byker,H, J

    2006-10-27

    Pleotint has embarked on a novel approach with our Sunlight Responsive Thermochromic, SRT™, windows. We are integrating dynamic sunlight control, high insulation values and low solar heat gain together in a high performance window. The Pleotint SRT window is dynamic because it reversibly changes light transmission based on thermochromics activated directly by the heating effect of sunlight. We can achieve a window package with low solar heat gain coefficient (SHGC), a low U value and high insulation. At the same time our windows provide good daylighting. Our innovative window design offers architects and building designers the opportunity to choose their desired energy performance, excellent sound reduction, external pane can be self-cleaning, or a resistance to wind load, blasts, bullets or hurricanes. SRT windows would provide energy savings that are estimated at up to 30% over traditional window systems. Glass fabricators will be able to use existing equipment to make the SRT window while adding value and flexibility to the basic design. Glazing installers will have the ability to fit the windows with traditional methods without wires, power supplies and controllers. SRT windows can be retrofit into existing buildings,

  6. Annual cycles of urinary reproductive steroid concentrations in wild and captive endangered Fijian ground frogs (Platymantis vitiana).

    Science.gov (United States)

    Narayan, Edward J; Molinia, Frank C; Christi, Ketan S; Morley, Craig G; Cockrem, John F

    2010-03-01

    Annual cycles of reproductive steroid metabolites were measured in urine collected from free-living and captive tropical endangered Fijian ground frogs (Platymantis vitiana) a terrestrial breeding. Free-living frogs were sampled on Viwa Island, Fiji and captive frogs were maintained in an outdoor enclosure in Suva, Fiji. Urinary estrone, progesterone and testosterone metabolite concentrations increased in male and female frogs after hCG challenges, with clear peaks in steroid concentrations 2 or 3 days after the challenges. There were annual cycles of testosterone metabolites in wild and captive males, and of estrone and progesterone metabolites in wild and captive females. Peaks of steroid concentrations in the wet season corresponded with periods of mating and egg laying in females in December and January. Steroid concentrations declined in January and February when maximum egg sizes in females were also declining. Body weights of wild male and vitellogenic female frogs showed annual cycles. Body weights of non-vitellogenic female frogs varied significantly between months, although there was no clear pattern of annual changes. Body weights of the 3 captive male frogs and 4 captive female frogs were similar to those of the wild frogs. Estrone metabolites were 80% successful in identifying non-vitellogenic females from males. The results suggest that the Fijian ground frog is a seasonal breeder with an annual gonadal cycle, and this species is likely to be photoperiodic. Urinary steroid measurements can provide useful information on reproductive cycles in endangered amphibians.

  7. Metallurgical source-contribution analysis of PM10 annual average concentration: A dispersion modeling approach in moravian-silesian region

    Directory of Open Access Journals (Sweden)

    P. Jančík

    2013-10-01

    Full Text Available The goal of the article is to present analysis of metallurgical industry contribution to annual average PM10 concentrations in Moravian-Silesian based on means of the air pollution modelling in accord with the Czech reference methodology SYMOS´97.

  8. Sunlight exposure: Do health benefits outweigh harm?

    Science.gov (United States)

    Razzaque, Mohammed S

    2016-09-16

    Vitamin D is a fat-soluble vitamin whose levels within the body are elevated following sunlight exposure. Numerous studies have shown that sunlight exposure can provide protection to a wide variety of diseases, ranging from different types of tumors to hypertension to type 1 diabetes to multiple sclerosis. Moreover, studies have shown that avoiding sunlight may influence the initiation and progression of some of these diseases. Avoidance of sunlight, coupled with the inclination towards consuming supplements, is becoming the primary choice to obtain vitamin D. The purpose of this article is to present evidences from published literature, to show that the expected benefits of vitamin D supplements are minimized by the potential risk of cardiovascular events and beyond. Since hypovitaminosis D status usually reflects reduced sunlight exposure, the obvious primary replacement should be safe sunlight exposure, and not exogenous supplements. Copyright © 2016 Elsevier Ltd. All rights reserved.

  9. Photocatalytic degradation of synthetic dye under sunlight

    Directory of Open Access Journals (Sweden)

    Mijin Dušan

    2007-01-01

    Full Text Available Synthetic dyes are widely used in the textile industry. Dye pollutants from the textile industry are an important source of environmental contamination. The majority of these dyes are toxic, mostly non-biodegradable and also resistant to decomposition by physico-chemical methods. Among new oxidation methods or "advanced oxidation processes", heterogeneous photocatalysis appears as an emerging destructive technology leading to the total mineralization of many organic pollutants. CI Basic Yellow 28 (BY28, commonly used as a textile dye, could be photocatalytically degraded using TiU2 as catalyst under sunlight. The effect of some parameters such as the initial catalyst concentration, initial dye concentration, initial NaCl and Na2CO3 concentrations, pH, H2O2 and type of catalyst on the degradation rate of BY28 was examined in details. The presence of NaCl and Na2CO3 led to inhibition of the photodegradation process. The highest photodegradation rate was observed at high pH, while the rate was the lowest at low pH. Increase of the initial H2O2 concentration increased the initial BY28 photodegradation efficiency. ZnO was a better catalyst than TiO2 at low dye concentrations.

  10. Using a Tree Ring δ13C Annual Series to Reconstruct Atmospheric CO2 Concentration over the Past 300 Years

    Institute of Scientific and Technical Information of China (English)

    ZHAO Xing-Yun; QIAN Jun-Long; WANG Jian; HE Qing-Yan; WANG Zu-Liang; CHEN Cheng-Zhong

    2006-01-01

    The annual series of δ13C were measured in tree rings of three Cryptomeria fortunei disks (CF-1, CF-2, and CF 3) collected from West Tianmu Mountain, Zhejiang Province, China, according to cross-dating tree ring ages. There was no obvious decreasing trend of the δ13C annual time series of CF-2 before 1835. However, from 1835 to 1982 the three tree ring δ13C annual series exhibited similar decreasing trends that were significantly (P ≤ 0.001) correlated. The distribution characteristics of a scatter diagram between estimated δ13C series of CF-2 from modeling and the atmospheric CO2 concentration extracted from the Law Dome ice core from 1840 to 1978 were analyzed and a curvilinear regression equation for reconstructing atmospheric CO2 concentration was established with R2 = 0.98.Also, a test of independent samples indicated that between 1685 and 1839 the reconstructed atmospheric CO2 concentration .using the δ13C series of CF-2 had a close relationship with the Law Dome and Siple ice cores, with a standard deviation of 1.98.The general increasing trend of the reconstructed atmospheric CO2 concentration closely reflected the long-term variation of atmospheric CO2 concentration recorded both before and after the Industrial Revolution. Between 1685 and 1840 the evaluated atmospheric CO2 concentration was stable, but after 1840 it exhibited a rapid increase. Given a longer δ13C annual time series of tree rings, it was feasible to rebuild a representative time series to describe the atmospheric CO2 concentration for an earlier period and for years that were not in the ice core record.

  11. Photovoltaics. III - Concentrators

    Science.gov (United States)

    Backus, C. E.

    1980-02-01

    Photovoltaic concentration systems that redirect sunlight falling on a surface to a smaller solar-cell surface concentrating the intensity of sunlight many times are examined. It is noted that solar cells for concentrating systems must be designed for low internal resistance as well as for high sunlight intensities. Two designs of silicon cells are presented that perform well at high concentrations; these are interdigitated back-contact cells and vertical multijunction cells. Attention is given to heat tapping of reemitted light.

  12. Derivation and implementation of an annual limit on intake and a derived air concentration value for uranium mill tailings.

    Science.gov (United States)

    Reif, R H; Andrews, D W

    1995-06-01

    Monitoring workers and work areas at the Department of Energy Uranium Mill Tailings Remedial Action Project sites is complex because all radionuclides in the 238U and 235U decay chains may be present in an airborne uranium mill tailings matrix. Previous monitoring practices involved isotopic analysis of the air filter to determine the activity of each radionuclide of concern and comparing the results to the specified derived air concentration. The annual limit on intake and derived air concentration values have been derived here for the uranium mill tailings matrix to simplify the procedure for evaluation of air monitoring results and assessment of the need for individual monitoring. Implementation of the derived air concentration for uranium mill tailings involves analyzing air samples for long-lived gross alpha activity and comparing the activity concentration to the derived air concentration. Health physics decisions regarding assessment of airborne concentrations is more cost-effective because isotopic analysis of air samples is not necessary.

  13. Amelioration of osteoporosis and hypovitaminosis D by sunlight exposure in Parkinson's disease.

    Science.gov (United States)

    Sato, Yoshihiro; Iwamoto, Jun; Honda, Yoshiaki

    2011-01-01

    A high incidence of fractures, particularly of the hip, represents an important problem in patients with Parkinson's disease (PD), who are prone to falls and have osteoporosis. We previously showed that 25-hydroxyvitamin D (25-OHD) deficiency due to sunlight deprivation with compensatory hyperparathyroidism causes reduced bone mineral density (BMD) in elderly patients with PD. The present study was undertaken to address the possibility that sunlight exposure may maintain BMD and reduce the incidence of hip fracture in elderly patients with PD. In a prospective study, PD patients were assigned to regular sunlight exposure (n=162) or usual lifestyle (n=162), and followed for 2 years. BMD of the second metacarpal bone was measured using a computed X-ray densitometer. Incidence of hip fracture in the two patient groups during the 2 year follow-up period was assessed. At baseline, patients of both groups showed vitamin D deficiency due to sunlight deprivation with compensatory hyperparathyroidism. The exposed group patients were exposed to sunlight (3231 min/year). BMD increased by 3.8% in the sunlight-exposed group and decreased by 2.6% in the usual lifestyle group (psunlight-exposed group. Eleven patients sustained hip fracture in the normal lifestyle group, and 3 fractures occurred among the sunlight-exposed group (p=.03; odds ratio=2.4). Sunlight exposure can increase the BMD of vitamin D deficient bone by increasing 25-OHD concentration and leads to the prevention of hip fracture. © 2010 Elsevier Ltd. All rights reserved.

  14. Sunlight technologies for photochemical deactivation of organic pollutants in water

    Energy Technology Data Exchange (ETDEWEB)

    Acher, A.; Fischer, E.; Tornheim, R. [The Volcani Center, Inst. of Soils and Water, Bet Dagan (Israel); Manor, Y. [Sheba Medical Center, Central Virology Lab., Ramat Gan (Israel)

    1997-12-31

    Sensitized-photochemical oxidation methods aimed at use in water treatment technologies for deactivation of biotic (microorganisms) and/or of xenobiotic (pesticides) pollutants in water were developed using global solar radiation or concentrated sunlight (up to 250 suns). The solar global radiation was used either for detoxification of industrial waste water from a pesticide factory to allow their discharge into the urban sewer, or for disinfection of domestric effluents to be used in crop irrigation. The disinfection process was eventually carried out in an experimental pilot-scale plant, capable of disinfection up to 50 m{sup 3}/h of effluent supplied by an activated sludge sewage treatment plant located in Tel-Aviv area. The treated effluents did not show any regrowth of the microorganisms during 7 days. The solar concentrated radiation experiments performed using facilities of the Sun Tower of The Weizman Institute of Science, Rehovot. The concentrated sunlight was provided by different combination of several computer controlled heliostates, up to 8, that track the sun and focus the received sunlight onto the target situated on the roof of the sun-tower. The sunlight intensities measured on the target reached up to 200 kW/m{sup 2}. The experiments were performed either batch- or continuous-wise. The water-samples exposed to disinfection were the above effluent, filtered and supplemented with vaccine strain poliovirus or with different concentrations of an industrial potential pollutant (bromacil), MB 2 mg/L and two concentrations of dissolved oxygen (8.0 or 40.0 mg O{sub 2}/L). An exposure time of 2-3 seconds at 150 kW/m{sup 2} was decreased the microorganisms alive (counts) by five orders of magnitude. A comparison between the two above water treatment technologies is presented. (orig./SR)

  15. Technique to separate lidar signal and sunlight.

    Science.gov (United States)

    Sun, Wenbo; Hu, Yongxiang; MacDonnell, David G; Weimer, Carl; Baize, Rosemary R

    2016-06-13

    Sunlight contamination dominates the backscatter noise in space-based lidar measurements during daytime. The background scattered sunlight is highly variable and dependent upon the surface and atmospheric albedo. The scattered sunlight contribution to noise increases over land and snow surfaces where surface albedos are high and thus overwhelm lidar backscatter from optically thin atmospheric constituents like aerosols and thin clouds. In this work, we developed a novel lidar remote sensing concept that potentially can eliminate sunlight induced noise. The new lidar concept requires: (1) a transmitted laser light that carries orbital angular momentum (OAM); and (2) a photon sieve (PS) diffractive filter that separates scattered sunlight from laser light backscattered from the atmosphere, ocean and solid surfaces. The method is based on numerical modeling of the focusing of Laguerre-Gaussian (LG) laser beam and plane-wave light by a PS. The model results show that after passing through a PS, laser light that carries the OAM is focused on a ring (called "focal ring" here) on the focal plane of the PS filter, very little energy arrives at the center of the focal plane. However, scattered sunlight, as a plane wave without the OAM, focuses at the center of the focal plane and thus can be effectively blocked or ducted out. We also find that the radius of the "focal ring" increases with the increase of azimuthal mode (L) of LG laser light, thus increasing L can more effectively separate the lidar signal away from the sunlight noise.

  16. Procedure for the characterization of radon potential in existing dwellings and to assess the annual average indoor radon concentration.

    Science.gov (United States)

    Collignan, Bernard; Powaga, Emilie

    2014-11-01

    Risk assessment due to radon exposure indoors is based on annual average indoor radon activity concentration. To assess the radon exposure in a building, measurement is generally performed during at least two months during heating period in order to be representative of the annual average value. This is because radon presence indoors could be very variable during time. This measurement protocol is fairly reliable but may be a limiting in the radon risk management, particularly during a real estate transaction due to the duration of the measurement and the limitation of the measurement period. A previous field study defined a rapid methodology to characterize radon entry in dwellings. The objective of this study was at first, to test this methodology in various dwellings to assess its relevance with a daily test. At second, a ventilation model was used to assess numerically the air renewal of a building, the indoor air quality all along the year and the annual average indoor radon activity concentration, based on local meteorological conditions, some building characteristics and in-situ characterization of indoor pollutant emission laws. Experimental results obtained on thirteen individual dwellings showed that it is generally possible to obtain a representative characterization of radon entry into homes. It was also possible to refine the methodology defined in the previous study. In addition, numerical assessments of annual average indoor radon activity concentration showed generally a good agreement with measured values. These results are encouraging to allow a procedure with a short measurement time to be used to characterize long-term radon potential in dwellings.

  17. Varying relationship between 25-hydroxy-vitamin D, high density lipoprotein cholesterol, and serum 7-dehydrocholesterol reductase with sunlight exposure.

    Science.gov (United States)

    Patwardhan, Vivek G; Khadilkar, Anuradha V; Chiplonkar, Shashi A; Mughal, Zulf M; Khadilkar, Vaman V

    2015-01-01

    Cholesterol and cholecalciferol are synthesized from a common substrate 7-dehydrocholesterol. 7-dehydrocholesterol is converted to cholesterol by 7-dehydrocholesterol reductase enzyme (DHCR7) and to cholecalciferol by ultraviolet B radiation from sunlight. To examine the effect of sunlight exposure and serum DHCR7 levels on cholecalciferol and cholesterol levels and studying any interrelationship. In a cross-sectional observational study, 307 apparently healthy men (aged 40-60 years) were assessed for sunlight exposure, lipid levels, serum DHCR7, 25 hydroxyvitamin D (25(OH)D), body composition, and dietary milk calcium intake. Vitamin D deficiency (25(OH)D sunlight exposure (P sunlight exposure (sunlight exposure (1-2 h/d), there was no significant association. However, with higher sunlight exposure (>2 h/d), serum 25(OH)D concentrations were significantly negatively associated with HDL-C (P sunlight exposure, an inverse significant relationship was observed between 25(OH)D and serum DHCR7 (P sunlight exposure, no significant relationship was seen. 25(OH)D seems to show a varying relationship with HDL-C and serum DHCR7 at different durations of sunlight exposure. Copyright © 2015 National Lipid Association. Published by Elsevier Inc. All rights reserved.

  18. Can Natural Sunlight Induce Coherent Exciton Dynamics?

    CERN Document Server

    Olšina, Jan; Wang, Chen; Cao, Jianshu

    2014-01-01

    Excitation of a model photosynthetic molecular aggregate by incoherent sunlight is systematically examined. For a closed system, the excited state coherence induced by the sunlight oscillates with an average amplitude that is inversely proportional to the excitonic gap, and reaches a stationary amplitude that depends on the temperature and coherence time of the radiation field. For an open system, the light-induced dynamical coherence relaxes to a static coherence determined by the non-canonical thermal distribution resulting from the entanglement with the phonon bath. The decay of the excited state population to the common ground state establishes a non-equilibrium steady-state flux driven by the sunlight, and it defines a time window to observe the transition from dynamical to static coherence. For the parameters relevant to photosynthetic systems, the exciton dynamics initiated by the sunlight exhibits a non-negligible amount of dynamical coherence (quantum beats) on the sub-picosecond timescale; however, ...

  19. Supplementing vitamin D through sunlight: associating health literacy with sunlight exposure behavior.

    Science.gov (United States)

    Leung, Angela Yee Man; Cheung, Mike Kwun Ting; Chi, Iris

    2015-01-01

    To test whether health literacy is associated with sunlight exposure behavior, we interviewed 648 Chinese adults aged 65 years or older. Using the information-motivation-behavioral skills model and structural equation modeling, we tested whether health literacy was associated with the complex relationships among knowledge about vitamin D, attitudes toward sunlight exposure, doctor recommendations regarding sunlight exposure, and sunlight exposure behavior. Health literacy was directly associated with sunlight exposure (β=.20, psunlight exposure through health literacy (β=.46, psunlight exposure through health literacy (β=-.12, psunlight exposure. Providing relevant knowledge or making doctor recommendations might not be effective. Training should focus on individuals with low health literacy who may be less likely to receive sunlight exposure. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  20. Changes in swainsonine, calystegine, and nitrogen concentrations on an annual basis in Ipomoea carnea.

    Science.gov (United States)

    Cook, Daniel; Oliveira, Carlos A; Gardner, Dale R; Pfister, James A; Riet-Correa, Gabriela; Riet-Correa, Franklin

    2015-03-01

    Ipomoea carnea, a swainsonine containing plant, is known to cause a neurologic disease in grazing livestock in Brazil and other parts of the world. To better understand the relative toxicity and nutritional content of I. carnea we investigated swainsonine, calystegine, and crude protein concentrations in leaves of I. carnea on a monthly basis for one year in northern and northeastern Brazil. Swainsonine concentrations were detected at concentrations that could potentially poison an animal throughout the year although there was some variation between months. At one location swainsonine concentrations were generally the highest during the rainy season or the months immediately following the rainy season. Total calystegine concentrations were similar to those reported previously while crude protein concentrations were similar to those found in other Ipomoea species and are such that they may explain why I. carnea becomes desirable to grazing livestock as forage becomes limited during the dry season.

  1. Organosulfates and organic acids in Arctic aerosols: Speciation, annual variation and concentration levels

    DEFF Research Database (Denmark)

    Hansen, Anne Maria Kaldal; Kristensen, Kasper; Nguyen, Quynh

    2014-01-01

    concentrations of organosulfates (47 +/- 14 ng m(-3)) and organic acids (11.5 +/- 4 ng m(-3)) were observed in January, February and March, contrary to considerably lower mean concentrations of organosulfates (2 +/- 3 ng m(3-)) and organic acids (2.2 +/- 1 ng m(-3)) observed during the rest of the year...... organosulfates - from both anthropogenic and biogenic precursors were in focus. A total of 11 organic acids (terpenylic acid, benzoic acid, phthalic acid, pinic acid, suberic acid, azelaic acid, adipic acid, pimelic acid, pinonic acid, diaterpenylic acid acetate and 3-methyl-1,2,3-butanetricarboxylic acid), 12....... At Zeppelin Mountain, organosulfate and organic acid concentrations remained relatively constant during most of the year at a mean concentration of 15 +/- 4 ng m(-3) and 3.9 +/- 1 ng m(-3), respectively. However during four weeks of spring, remarkably higher concentrations of total organosulfates (23-36 ng m...

  2. Sensitivity of simulated CO2 concentration to sub-annual variations in fossil fuel CO2 emissions

    Science.gov (United States)

    Zhang, X.; Gurney, K. R.; Rayner, P. J.; Baker, D. F.; Liu, Y.; Asefi-Najafabady, S.

    2014-12-01

    This study presents a sensitivity analysis of the impact of sub-annual fossil fuel CO2 emissions on simulated CO2 concentration using a global tracer transport model. Four sensitivity experiments were conducted to investigate the impact of three cyclic components (diurnal, weekly and monthly) and a complete cyclic component (the combination of the three) by comparing with a temporally "flat" fossil fuel CO2 emissions inventory. A complete exploration of these impacts is quantified at annual, seasonal, weekly and diurnal time scales of the CO2concentration for the surface, vertical profile and column-integral structure. Result shows an annual mean surface concentration difference varying from -1.35 ppm to 0.13 ppm at grid scale for the complete cyclic fossil fuel emissions, which is mainly driven by a large negative diurnal rectification and less positive seasonal rectification. The negative diurnal rectification is up to 1.45 ppm at grid scale and primarily due to the covariation of diurnal fossil fuel CO2 emissions and diurnal variations of vertical mixing. The positive seasonal rectification is up to 0.23 ppm at grid scale which is mainly driven by the monthly fossil fuel CO2emissions coupling with atmospheric transport. Both the diurnal and seasonal rectifier effects are indicated at local-to-regional scales with center at large source regions and extend to neighboring regions in mainly Northern Hemisphere. The diurnal fossil fuel CO2 emissions is found to significantly affect the simulated diurnal CO2 amplitude (up to 9.12 ppm at grid scale), which is primarily contributed by the minima concentration differences around local sunset time. Similarly, large impact on the seasonal CO2 amplitude (up to 6.11 ppm) is found at regional scale for the monthly fossil fuel emissions. An impact of diurnal fossil fuel CO2 emissions on simulated afternoon CO2 concentration is also identified by up to 1.13 ppm at local scales. The study demonstrates a large cyclic fossil fuel

  3. Climate Change Effects on Annual Average Concentrations of Fine Particulate Matter (PM2.5) in California

    Science.gov (United States)

    Kleeman, M.; Mahmud, A.

    2008-12-01

    California has one of the worst particulate air pollution problems in the nation with some estimates predicting more than 5000 premature deaths each year attributed to air pollution. Climate change will modify weather patterns in California with unknown consequences for PM2.5. Previous down-scaling exercises carried out for the entire United States have typically not resolved the details associated with California's mountain-valley topography and mixture of urban-rural emissions characteristics. Detailed studies carried out for California have identified strong effects acting in opposite directions on PM2.5 concentrations making the net prediction for climate effects on PM2.5 somewhat uncertain. More research is needed to reduce this uncertainty so that we can truly understand climate impacts on PM2.5 and public health. The objective of this research is to predict climate change effects on annual average concentrations of particulate matter (PM2.5) in California with sufficient resolution to capture the details of California's air basins. Business-as-usual scenarios generated by the Parallel Climate Model (PCM) will be down-scaled to 4km meteorology using the Weather Research Forecast (WRF) model. The CIT/UCD source-oriented photochemical air quality model will be employed to predict PM2.5 concentrations throughout the entire state of California. The modeled annual average total and speciated PM2.5 concentrations for the future (2047-2049) and the present-day (2004-2006) periods will be compared to determine climate change effects. The results from this study will improve our understanding of global climate change effects on PM2.5 concentrations in California.

  4. Sunlight Diffusing Tent for Lunar Worksite

    Science.gov (United States)

    Burleson, Blair; Clark, Todd; Deese, Todd; Gentry, Ernest; Samad, Abdul

    1990-01-01

    The purpose is to provide a solution to problems astronauts encounter with sunlight on the lunar surface. Due to the absence of an atmosphere the Moon is subjected to intense sunlight creating problems with color and contrast. This problem can be overcome by providing a way to reduce intensity and diffuse the light in a working environment. The solution to the problem utilizes an umbrella, tent-like structure covered with a diffusing material. The design takes into account structural materials, stresses, fabrics, and deployment.

  5. Evaluation of annual efficiencies of high temperature central receiver concentrated solar power plants with thermal energy storage.

    Energy Technology Data Exchange (ETDEWEB)

    Ehrhart, Brian David; Gill, David Dennis

    2013-07-01

    The current study has examined four cases of a central receiver concentrated solar power plant with thermal energy storage using the DELSOL and SOLERGY computer codes. The current state-of-the-art base case was compared with a theoretical high temperature case which was based on the scaling of some input parameters and the estimation of other parameters based on performance targets from the Department of Energy SunShot Initiative. This comparison was done for both current and high temperature cases in two configurations: a surround field with an external cylindrical receiver and a north field with a single cavity receiver. There is a fairly dramatic difference between the design point and annual average performance, especially in the solar field and receiver subsystems, and also in energy losses due to the thermal energy storage being full to capacity. Additionally, there are relatively small differences (<2%) in annual average efficiencies between the Base and High Temperature cases, despite an increase in thermal to electric conversion efficiency of over 8%. This is due the increased thermal losses at higher temperature and operational losses due to subsystem start-up and shut-down. Thermal energy storage can mitigate some of these losses by utilizing larger thermal energy storage to ensure that the electric power production system does not need to stop and re-start as often, but solar energy is inherently transient. Economic and cost considerations were not considered here, but will have a significant impact on solar thermal electric power production strategy and sizing.

  6. Effect of photoperiod on serum hormone concentrations during the annual reproductive cycle in geese.

    Science.gov (United States)

    Zhao, X Z; Gao, G L; Wang, H W; Li, Q; Zhang, K S; Zhong, H; Wang, Q G

    2017-03-22

    The poor egg-laying rate of geese hinders the development of the goose industry; therefore, the reproductive performance of geese is an important area of investigation. To evaluate the relationship between photoperiod, reproductive hormones, and reproductive activity during the egg-laying cycle in geese under natural conditions, we collected blood samples from Sichuan white geese and Xupu geese to quantify changes in prolactin (PRL), estradiol (E2), vasoactive intestinal polypeptide (VIP), follicle stimulating hormone (FSH), gonadotropin-inhibitory hormone (GnIH), and luteinizing hormone (LH). We also calculated the rate of egg laying for the two populations during the egg-laying cycle. We show that the egg-laying rate and the serum concentration of some hormones (PRL, E2, VIP, FSH, GnIH, and LH) differed significantly between the two populations during the pre-laying, laying, and ceased-laying periods. Serum LH concentrations may be associated with maturation of the ovary and oviducts, whereas FSH, PRL, and GnIH play important roles in egg laying. These results provide a useful resource for future studies examining the laying rate in geese.

  7. Photochemical Transformation of Graphene Oxide in Sunlight

    Science.gov (United States)

    Graphene oxide (GO) is a graphene derivative that is more easily manufactured in large scale and used to synthesize reduced graphene oxide (rGO) with properties analogous to graphene. In this study, we investigate the photochemical fate of GO under sunlight conditions. The resu...

  8. Inter-annual Variations and Decadal Trends in Surface Equatorial Pacific Phosphate Concentrations: Coral Records from the Line Islands

    Science.gov (United States)

    Sinclair, D. J.; Sherrell, R. M.; LaVigne, M.; Tudhope, A. W.; Cobb, K.

    2011-12-01

    Coralline P/Ca is a newly-calibrated proxy for oceanic phosphate concentration (LaVigne et al. 2010, Anagnostuou et al. 2011). This proxy is an important tool for reconstructing tropical ocean nutrient dynamics, especially in remote regions, such as the equatorial Pacific Ocean, which are poorly covered by instrumental records. Here we present P/Ca records in 4 Porites corals from the Line Islands in the central Equatorial Pacific spanning the last ~ 30 years. The coral from Jarvis Island (0°22'S) has a significantly higher P/Ca concentration than two independent coral records from Christmas Island (1°53'N), and a coral from Fanning Island (3°51'N). This is consistent with the strong meridional gradient in surface phosphate in the central equatorial Pacific. All corals record a long-term 2-fold decrease in phosphate concentration from the mid 1970s to the mid 1990s, in agreement with observed slowing of the Pacific Meridional Overturning Circulation (McPhadden and Zhang 2002). On inter-annual time scales, the corals all capture strong El Niño events as a decrease in surface phosphate consistent with deepening of the eastern Pacific thermocline. The magnitude of this suppression is significantly larger in the Jarvis Island coral, again consistent with its location in the high phosphate tongue in the equatorial Pacific. The Jarvis Island coral record shows hints of a decadal oscillation in P which so far does not appear to be captured by the Christmas Island coral. Further analyses are underway to extend these records and to study P dynamics in other Line Island corals. Our preliminary results suggest that Porites corals are recording P variations in the central Pacific which accord with known oceanographic changes. This study demonstrates the potential for reconstructing nutrient dynamics at annual to multidecadal resolutions. Citations LaVigne M., Matthews K. A., Grottoli A. G., Cobb K. M., Anagnostou E., Cabioch G., and Sherrell R. M. (2010) Coral skeleton P

  9. Sunlight-induced carbon dioxide emissions from inland waters

    Science.gov (United States)

    Koehler, Birgit; Landelius, Tomas; Weyhenmeyer, Gesa A.; Machida, Nanako; Tranvik, Lars J.

    2014-07-01

    The emissions of carbon dioxide (CO2) from inland waters are substantial on a global scale. Yet the fundamental question remains open which proportion of these CO2 emissions is induced by sunlight via photochemical mineralization of dissolved organic carbon (DOC), rather than by microbial respiration during DOC decomposition. Also, it is unknown on larger spatial and temporal scales how photochemical mineralization compares to other C fluxes in the inland water C cycle. We combined field and laboratory data with atmospheric radiative transfer modeling to parameterize a photochemical rate model for each day of the year 2009, for 1086 lakes situated between latitudes from 55°N to 69°N in Sweden. The sunlight-induced production of dissolved inorganic carbon (DIC) averaged 3.8 ± 0.04 g C m-2 yr-1, which is a flux comparable in size to the organic carbon burial in the lake sediments. Countrywide, 151 ± 1 kt C yr-1 was produced by photochemical mineralization, corresponding to about 12% of total annual mean CO2 emissions from Swedish lakes. With a median depth of 3.2 m, the lakes were generally deep enough that incoming, photochemically active photons were absorbed in the water column. This resulted in a linear positive relationship between DIC photoproduction and the incoming photon flux, which corresponds to the absorbed photons. Therefore, the slope of the regression line represents the wavelength- and depth-integrated apparent quantum yield of DIC photoproduction. We used this relationship to obtain a first estimate of DIC photoproduction in lakes and reservoirs worldwide. Global DIC photoproduction amounted to 13 and 35 Mt C yr-1 under overcast and clear sky, respectively. Consequently, these directly sunlight-induced CO2 emissions contribute up to about one tenth to the global CO2 emissions from lakes and reservoirs, corroborating that microbial respiration contributes a substantially larger share than formerly thought, and generate annual C fluxes similar in

  10. Sunlight induced photo reactivity of drugs

    Energy Technology Data Exchange (ETDEWEB)

    Dallera, R.; Dondi, D.; Ricci, A.; Fasani, E.; Albini, A.

    2003-07-01

    The reactivity under natural light of some UVA-UVB photol able drugs belonging to the classes of fluoroquinolones, glucocortocosteroids, sunscreens and nitrophenyldihydropyridines has been investigated. The data suggest that exposition to sunlight for times ranging from some minutes to few hours at PSA is sufficient for promoting a high degradation in the drugs investigated. the chemical reactions are the same as observed under artificial UV light. (Author) 28 refs.

  11. The Seasonality of Tuberculosis, Sunlight, Vitamin D, and Household Crowding

    Science.gov (United States)

    Wingfield, Tom; Schumacher, Samuel G.; Sandhu, Gurjinder; Tovar, Marco A.; Zevallos, Karine; Baldwin, Matthew R.; Montoya, Rosario; Ramos, Eric S.; Jongkaewwattana, Chulanee; Lewis, James J.; Gilman, Robert H.; Friedland, Jon S.; Evans, Carlton A.

    2014-01-01

    Background. Unlike other respiratory infections, tuberculosis diagnoses increase in summer. We performed an ecological analysis of this paradoxical seasonality in a Peruvian shantytown over 4 years. Methods. Tuberculosis symptom-onset and diagnosis dates were recorded for 852 patients. Their tuberculosis-exposed cohabitants were tested for tuberculosis infection with the tuberculin skin test (n = 1389) and QuantiFERON assay (n = 576) and vitamin D concentrations (n = 195) quantified from randomly selected cohabitants. Crowding was calculated for all tuberculosis-affected households and daily sunlight records obtained. Results. Fifty-seven percent of vitamin D measurements revealed deficiency (<50 nmol/L). Risk of deficiency was increased 2.0-fold by female sex (P < .001) and 1.4-fold by winter (P < .05). During the weeks following peak crowding and trough sunlight, there was a midwinter peak in vitamin D deficiency (P < .02). Peak vitamin D deficiency was followed 6 weeks later by a late-winter peak in tuberculin skin test positivity and 12 weeks after that by an early-summer peak in QuantiFERON positivity (both P < .04). Twelve weeks after peak QuantiFERON positivity, there was a midsummer peak in tuberculosis symptom onset (P < .05) followed after 3 weeks by a late-summer peak in tuberculosis diagnoses (P < .001). Conclusions. The intervals from midwinter peak crowding and trough sunlight to sequential peaks in vitamin D deficiency, tuberculosis infection, symptom onset, and diagnosis may explain the enigmatic late-summer peak in tuberculosis. PMID:24596279

  12. Sunlight exposure assessment: can we accurately assess vitamin D exposure from sunlight questionnaires?

    Science.gov (United States)

    McCarty, Catherine A

    2008-04-01

    The purpose of this review is to summarize the peer-reviewed literature in relation to sunlight exposure assessment and the validity of using sunlight exposure questionnaires to quantify vitamin D status. There is greater variability in personal ultraviolet (UV) light exposure as the result of personal behavior than as the result of ambient UV light exposure. Although statistically significant, the correlation coefficients for the relation between personal report of sun exposure and ambient UV light measured by dosimetry (assessment of radiation dose) are relatively low. Moreover, the few studies to assess the relation between sunlight measures and serum 25-hydroxyvitamin D show low correlations. These low correlations may not be surprising given that personal factors like melanin content in skin and age also influence cutaneous synthesis of vitamin D. In summary, sunlight exposure questionnaires currently provide imprecise estimates of vitamin D status. Research should be directed to develop more objective, nonintrusive, and economical measures of sunlight exposure to quantify personal vitamin D status.

  13. Modelling deposition and air concentration of reduced nitrogen in Poland and sensitivity to variability in annual meteorology.

    Science.gov (United States)

    Kryza, Maciej; Dore, Anthony J; Błaś, Marek; Sobik, Mieczysław

    2011-04-01

    The relative contribution of reduced nitrogen to acid and eutrophic deposition in Europe has increased recently as a result of European policies which have been successful in reducing SO(2) and NO(x) emissions but have had smaller impacts on ammonia (NH(3)) emissions. In this paper the Fine Resolution Atmospheric Multi-pollutant Exchange (FRAME) model was used to calculate the spatial patterns of annual average ammonia and ammonium (NH(4)(+)) air concentrations and reduced nitrogen (NH(x)) dry and wet deposition with a 5 km × 5 km grid for years 2002-2005. The modelled air concentrations of NH(3) and dry deposition of NH(x) show similar spatial patterns for all years considered. The largest year to year changes were found for wet deposition, which vary considerably with precipitation amount. The FRAME modelled air concentrations and wet deposition are in reasonable agreement with available measurements (Pearson's correlation coefficients above 0.6 for years 2002-2005), and with spatial patterns of concentrations and deposition of NH(x) reported with the EMEP results, but show larger spatial gradients. The error statistics show that the FRAME model results are in better agreement with measurements if compared with EMEP estimates. The differences in deposition budgets calculated with FRAME and EMEP do not exceed 17% for wet and 6% for dry deposition, with FRAME estimates higher than for EMEP wet deposition for modelled period and lower or equal for dry deposition. The FRAME estimates of wet deposition budget are lower than the measurement-based values reported by the Chief Inspectorate of Environmental Protection of Poland, with the differences by approximately 3%. Up to 93% of dry and 53% of wet deposition of NH(x) in Poland originates from national sources. Over the western part of Poland and mountainous areas in the south, transboundary transport can contribute over 80% of total (dry + wet) NH(x) deposition. The spatial pattern of the relative contribution of

  14. Greenhouse Effect: Temperature of a Metal Sphere Surrounded by a Glass Shell and Heated by Sunlight

    Science.gov (United States)

    Nguyen, Phuc H.; Matzner, Richard A.

    2012-01-01

    We study the greenhouse effect on a model satellite consisting of a tungsten sphere surrounded by a thin spherical, concentric glass shell, with a small gap between the sphere and the shell. The system sits in vacuum and is heated by sunlight incident along the "z"-axis. This development is a generalization of the simple treatment of the…

  15. Is casual exposure to summer sunlight effective at maintaining adequate vitamin D status?

    Science.gov (United States)

    Diffey, Brian L

    2010-08-01

    The advice that an adequate vitamin D status can be achieved by short, casual exposure to summer sunlight is ubiquitous. This review will examine the value of this advice. The results of experimental studies on changes in serum 25-hydroxyvitamin D [25(OH)D] concentrations following ultraviolet exposure are interpreted in the context of human exposure to sunlight. It is shown that current advice about modest sun exposure during the summer months does little in the way of boosting overall 25(OH)D levels, while sufficient sun exposure that could achieve a worthwhile benefit would compromise skin health. Failure to understand the nature of human exposure to sunlight has led to misguided advice concerning the sun exposure necessary for an adequate vitamin D status.

  16. High annual radon concentration in dwellings and natural radioactivity content in nearby soil in some rural areas of Kosovo and Metohija

    Directory of Open Access Journals (Sweden)

    Gulan Ljiljana R.

    2013-01-01

    Full Text Available Some previous studies on radon concentration in dwellings of some areas of Kosovo and Metohija have revealed a high average radon concentration, even though the detectors were exposed for three months only. In order to better design a larger study in this region, the annual measurements in 25 houses were carried out as a pilot study. For each house, CR-39-based passive devices were exposed in two rooms for the two consecutive six-month periods to account for seasonal variations of radon concentration. Furthermore, in order to correlate the indoor radon with radium in nearby soil and to improve the knowledge of the natural radioactivity in the region, soil samples near each house were collected and 226Ra, 232Th, 40K activity concentration were measured. The indoor radon concentration resulted quite high from the average (163 Bq/m3 and generally it did not differ considerably between the two rooms and the two six-month periods. The natural radionuclides in soil resulted to be distributed quite uniformly. Moreover, the correlation between the226Ra content in soil and radon concentration in dwellings resulted to be low (R2=0.26. The annual effective dose from radon and its short-lived progeny (5.5 mSv, in average was calculated by using the last ICRP dose conversion factors. In comparison, the contribution to the annual effective dose of outdoor gamma exposure from natural radionuclides in soil is nearly negligible (66 mSv. In conclusion, the observed high radon levels are only partially correlated with radium in soil; moreover, a good estimate of the annual average of radon concentration can be obtained from a six-month measurement with a proper choice of exposure period, which could be useful when designing large surveys.

  17. Hybrid sunlight/LED illumination and renewable solar energy saving concepts for indoor lighting.

    Science.gov (United States)

    Tsuei, Chih-Hsuan; Sun, Wen-Shing; Kuo, Chien-Cheng

    2010-11-08

    A hybrid method for using sunlight and light-emitting diode (LED) illumination powered by renewable solar energy for indoor lighting is simulated and presented in this study. We can illuminate an indoor space and collect the solar energy using an optical switching system. When the system is turned off, the full spectrum of the sunlight is concentrated by a concentrator, to be absorbed by solar photovoltaic devices that provide the electricity to power the LEDs. When the system is turned on, the sunlight collected by the concentrator is split into visible and non-visible rays by a beam splitter. The visible rays pass through the light guide into a light box where it is mixed with LED light to ultimately provide uniform illumination by a diffuser. The non-visible rays are absorbed by the solar photovoltaic devices to provide electrical power for the LEDs. Simulation results show that the efficiency of the hybrid sunlight/LED illumination with the renewable solar energy saving design is better than that of LED and traditional lighting systems.

  18. Persistence of benthiocarb in soil: influence of ultraviolet and sunlight

    Directory of Open Access Journals (Sweden)

    Md. Wasim Aktar

    2008-12-01

    Full Text Available Persistence of benthiocarb in soil as affected by UV and sunlight exposure was studied. Treated soil was placed in petri plate, brought to field capacity moisture and then exposed to UV and sunlight. Residues of benthiocarb in soil dissipated with half lives of 2.10, 11.85 and 43.63 days under UV, sunlight and dark condition, respectively. Soil samples kept under dark showed the slowest dissipation. Further, benthiocarb residues dissipated quickly under UV light as compared to sunlight. Exposure of thin film of benthiocarb confirmed that it is photo labile and dissipated very fast with half life of 1.16 and 1.77 days following exposure to UV and sunlight, respectively. The study revealed that UV component of sunlight is an important factor for benthiocarb dissipation.

  19. Concentrations and annual fluxes of sediment-associated chemical constituents from conterminous US coastal rivers using bed sediment data

    Science.gov (United States)

    Horowitz, Arthur J.; Stephens, Verlin C.; Elrick, Kent A.; Smith, James J.

    2012-01-01

    Coastal rivers represent a significant pathway for the delivery of natural and anthropogenic sediment-associated chemical constituents to the Atlantic, Pacific and Gulf of Mexico coasts of the conterminous USA. This study entails an accounting segment using published average annual suspended sediment fluxes with published sediment-associated chemical constituent concentrations for (1) baseline, (2) land-use distributions, (3) population density, and (4) worldwide means to estimate concentrations/annual fluxes for trace/major elements and total phosphorus, total organic and inorganic carbon, total nitrogen, and sulphur, for 131 coastal river basins. In addition, it entails a sampling and subsequent chemical analysis segment that provides a level of ‘ground truth’ for the calculated values, as well as generating baselines for sediment-associated concentrations/fluxes against which future changes can be evaluated. Currently, between 260 and 270 Mt of suspended sediment are discharged annually from the conterminous USA; about 69% is discharged from Gulf rivers (n = 36), about 24% from Pacific rivers (n = 42), and about 7% from Atlantic rivers (n = 54). Elevated sediment-associated chemical concentrations relative to baseline levels occur in the reverse order of sediment discharges:Atlantic rivers (49%)>Pacific rivers (40%)>Gulf rivers (23%). Elevated trace element concentrations (e.g. Cu, Hg, Pb, Zn) frequently occur in association with present/former industrial areas and/or urban centres, particularly along the northeast Atlantic coast. Elevated carbon and nutrient concentrations occur along both the Atlantic and Gulf coasts but are dominated by rivers in the urban northeast and by southeastern and Gulf coast (Florida) ‘blackwater’ streams. Elevated Ca, Mg, K, and Na distributions tend to reflect local petrology, whereas elevated Ti, S, Fe, and Al concentrations are ubiquitous, possibly because they have substantial natural as well as anthropogenic sources

  20. South African university student knowledge of eye protection against sunlight

    OpenAIRE

    O. A. Oduntan; A. Carelson; P. Clarke-Farr; R. Hansraj

    2009-01-01

    Exposure to sunlight has been associated with several ocular conditions such as cataract, age-related macular degeneration, and conjunctival neoplasm. Knowledge of protective modalities and good behavioural practice involving eye protection is essential to prevent adverse effects of sunlight. The purpose of this study was to establish knowledge amongst randomly selected university students in South Africa, of prevention modalities against the adverse effects of sunlight. A questionnaire relat...

  1. Sunlight exposure increases vitamin D sufficiency in growing pigs fed a diet formulated to exceed requirements.

    Science.gov (United States)

    Alexander, B M; Ingold, B C; Young, J L; Fensterseifer, S R; Wechsler, P J; Austin, K J; Larson-Meyer, D E

    2017-04-01

    Traditional confinement practices limit exposure to sunlight and vitamin D synthesis, and vitamin insufficiency occurs even with dietary supplementation. The aim of this study was to determine the effect of limited sun exposure on serum concentration of vitamin D and the expression of vitamin D synthesizing enzymes in the liver and kidney of pigs on a vitamin D sufficient diet. White-pigmented grower pigs (29.7 ± 2.3 kg) fed 15% CP diet ad libitum providing >1,200 IU vitamin D3/kg of feed were exposed to sunlight for 1 h each day at solar noon for 14 d at the spring equinox (March pigs, n = 10) or summer solstice (June pigs, n = 5) and again before slaughter in June (March pigs) and September (June pigs). Blood for the analysis of 25(OH)D was collected before and after sunlight exposure. Traditionally housed pigs served as controls. After initial sun exposure, blood samples were collected from June pigs daily for 5 d and weekly for 8 wk to determine vitamin D3 and 25(OH)D decay, respectively. Kidney and liver samples were collected from the June pigs at slaughter after sun exposure for analysis of messenger RNA expression of vitamin D binding protein and synthesizing/degrading enzymes. Average daily gain (ADG) was not influenced (P > 0.5) by sunlight exposure. June pigs had fewer days on feed, lower (P = 0.003) ADG and were slaughtered at a lighter (P Exposure to sunlight increased (P sunlight exposure increased serum concentration of 25(OH)D in March pigs by 200% and June pigs by 67%. Serum concentration of vitamin D3 was decreased (P exposure. Expression of vitamin D binding protein, vitamin D synthesizing CYP2R1, CYP27A1, CYP2D25, or degrading enzyme CYP24A1 were not influenced (P ≥ 0.19) by sunlight exposure. Expression of CYP27B1 was decreased (P = 0.04) in the kidney but tended to be increased (P = 0.06) in the liver after sun exposure. These results suggest limited sun exposure can efficiently increase serum concentration of vitamin D in growing pigs

  2. Photolysis of brominated flame retardants in textiles exposed to natural sunlight.

    Science.gov (United States)

    Kajiwara, Natsuko; Desborough, Jennifer; Harrad, Stuart; Takigami, Hidetaka

    2013-03-01

    Photolytic transformation profiles of technical hexabromocyclododecane (HBCD) and technical decabromodiphenyl ether (DecaBDE) in flame-retarded textiles exposed to natural sunlight were compared. Textiles that contained approximately 4% HBCDs by weight showed no substantial loss of any of the HBCD diastereomers during the entire exposure period (371 days), indicating that they were resistant to sunlight, that is, that debromination and isomerization of HBCD diastereomers did not occur under the experimental conditions. Exposure of a textile treated with technical DecaBDE resulted in the formation of polybrominated dibenzofurans (PBDFs) as products of photodecomposition of polybrominated diphenyl ethers present in the technical DecaBDE. After 329 days of exposure, the total PBDF concentration reached a maximum of 27 000 ng g(-1), which was approximately 10 times the initial concentration. During the experiment, di- to hexa-BDF congener concentrations increased continuously. Although the concentrations of PBDFs in the textiles were 4–5 orders of magnitude lower than the concentrations of polybrominated diphenyl ethers, it is important to note that PBDFs were formed as a result of sunlight exposure during normal use of products treated with technical DecaBDE.

  3. Sunlight exposure or vitamin D supplementation for vitamin D-deficient non-western immigrants: a randomized clinical trial.

    Science.gov (United States)

    Wicherts, I S; Boeke, A J P; van der Meer, I M; van Schoor, N M; Knol, D L; Lips, P

    2011-03-01

    Vitamin D deficiency is very common in non-western immigrants. In this randomized clinical trial, vitamin D 800 IU/day or 100,000 IU/3 months were compared with advised sunlight exposure. Vitamin D supplementation was more effective than advised sunlight exposure in improving vitamin D status and lowering parathyroid hormone levels. Vitamin D deficiency (25-hydroxyvitamin D [25(OH)D] sunlight exposure. To determine whether the effect of vitamin D(3) supplementation (daily 800 IU or 100,000 IU/3 months) or sunlight exposure advice is similar with regard to serum 25(OH)D and parathyroid hormone (PTH) concentrations. Randomized clinical trial in 11 general practices in The Netherlands. Non-western immigrants, aged 18-65 years (n = 232) and serum 25(OH)D sunlight exposure for 6 months (March-September). Blood samples were collected at baseline, during treatment (3 months, 6 months), and at follow-up (12 months). Statistical analysis was performed with multilevel regression modelling. The intention-to-treat analysis included 211 persons. Baseline serum 25(OH)D was 22.5 ± 11.1 nmol/l. After 6 months, mean serum 25(OH)D increased to 53 nmol/l with 800 IU/day, to 50.5 nmol/l with 100,000 IU/3 months, and to 29.1 nmol/l with advised sunlight exposure (supplementation vs sunshine p sunlight group (p sunlight exposure for treating vitamin D deficiency in non-western immigrants.

  4. Mean annual {sup 222}Rn concentration in homes located in different geological regions of Poland - first approach to whole country area

    Energy Technology Data Exchange (ETDEWEB)

    Przylibski, Tadeusz A., E-mail: Tadeusz.Przylibski@pwr.wroc.pl [Wroclaw University of Technology, Faculty of Geoengineering, Mining and Geology, Institute of Mining, Division of Geology and Mineral Waters, Wybrzeze S. Wyspianskiego 27, 50-370 Wroclaw (Poland); Zebrowski, Adam [Wroclaw University of Technology, Wybrzeze S. Wyspianskiego 27, 50-370 Wroclaw (Poland); Karpinska, Maria; Kapala, Jacek [Medical University of Bialystok, Department of Biophysics, ul. Mickiewicza 2A, 15-089 Bialystok (Poland); Kozak, Krzysztof; Mazur, Jadwiga; Grzadziel, Dominik [The Henryk Niewodniczanski Institute of Nuclear Physics, Polish Academy of Science, Laboratory of Radiometric Expertise, ul. W. E. Radzikowskiego 152, 31-342 Krakow (Poland); Mamont-Ciesla, Kalina; Stawarz, Olga [Central Laboratory for Radiological Protection, ul. Konwaliowa 7, 03-194 Warsaw (Poland); Kozlowska, Beata; Klos, Barbara; Dorda, Jerzy [University of Silesia, Institute of Physics, Department of Nuclear Physics and Its Applications, ul. Uniwersytecka 4, 40-007 Katowice (Poland); Wysocka, Malgorzata [Central Mining Institute, Department of Technical Acoustics, Laser Technique and Radiometry, Laboratory of Radiometry, Plac Gwarkow 1, 40-166 Katowice (Poland); Olszewski, Jerzy [The Nofer Institute of Occupational Medicine, Radiation Protection Department, ul. Sw. Teresy 8, 91-348 Lodz (Poland); Dohojda, Marek [Building Research Institute, Department of Structures and Building Elements, ul. Filtrowa 1, 00-611 Warsaw (Poland)

    2011-08-15

    The paper presents the results of year-long measurements of radon ({sup 222}Rn) concentration inside 129 buildings in Poland in relation to the geological conditions of their foundation. The authors took into account the division of the country into tectonic units, as well as the lithology of the rocks forming the bedrock of these buildings. As expected, the highest value of mean annual {sup 222}Rn concentration (845 Bq/m{sup 3}) was recorded in a building situated in the area of the Sudetes, while the highest geometric mean (characteristic of the expected log-normal data distribution) was calculated based on measurements from buildings located within the East-European craton, in the area of Mazury-Podlasie monocline, where it reached 231 Bq/m{sup 3}. Such results reflect geological conditions - the occurrence of crystalline rocks (especially U- and Ra-enriched granites and orthogneisses) on the surface in the Sudetes, and of young post-glacial sediments containing fragments of Scandinavian crystalline rocks, also enriched with U and Ra, in the area of Mazury-Podlasie monocline. However, the least expected result of the investigations was finding out that, contrary to the hitherto widespread belief, none of the major tectonic units of Poland can be excluded from the list of those containing buildings with mean annual {sup 222}Rn concentration exceeding 200 Bq/m{sup 3}. The mean annual concentration of radon for all the buildings were much higher than the mean concentration value (49.1 Bq/m{sup 3}) of indoor radon in Poland quoted so far. These results cast a completely new light on the necessity to perform measurements of radon concentration in residential buildings in Poland, no more with reference to small areas with outcrops of crystalline rocks (especially the Sudetes, being the Polish fragment of the European Variscan belt), but for all the major tectonic units within Poland. - Highlights: > {sup 222}Rn concentration in 129 buildings in Poland is presented

  5. Increased concentrations of polycyclic aromatic hydrocarbons in Alpine streams during annual snowmelt: investigating effects of sampling method, site characteristics, and meteorology.

    Science.gov (United States)

    Shahpoury, Pourya; Hageman, Kimberly J; Matthaei, Christoph D; Alumbaugh, Robert E; Cook, Michelle E

    2014-10-07

    Silicone passive samplers and macroinvertebrates were used to measure time-integrated concentrations of polycyclic aromatic hydrocarbons (PAHs) in alpine streams during annual snowmelt. The three sampling sites were located near a main highway in Arthur's Pass National Park in the Southern Alps of New Zealand. A similar set of PAH congeners, composed of 2-4 rings, were found in silicone passive samplers and macroinvertebrates. The background PAH concentrations were similar at all sites, implying that proximity to the highway did not affect concentrations. In passive samplers, an increase of PAH concentrations by up to seven times was observed during snowmelt. In macroinvertebrates, the concentration changes were moderate; however, macroinvertebrate sampling did not occur during the main pulse observed in the passive samplers. The extent of vegetation in the catchment appeared to affect the concentration patterns seen at the different stream sites. A strong correlation was found between PAH concentrations in passive samplers and the amount of rainfall in the study area, indicating that the washout of contaminants from snowpack by rainfall was an important process.

  6. Highly Branched Sn-Doped ZnO Nanostructures for Sunlight Driven Photocatalytic Reactions

    Directory of Open Access Journals (Sweden)

    Yangyang Liu

    2014-01-01

    Full Text Available Ultralong, highly branched Sn-doped zinc oxide (ZnO nanostructures were fabricated using a simple substrate-free chemical vapor deposition (CVD method. The nanostructures exhibited efficient photocatalytic activities in degradation of methylene blue (MB under natural sunlight. 100% of MB with the concentration of 10 mg/L could be completely removed within 36 minutes. Possible reasons for the enhanced photocatalytic effect were analyzed.

  7. Highly Branched Sn-Doped ZnO Nanostructures for Sunlight Driven Photocatalytic Reactions

    OpenAIRE

    2014-01-01

    Ultralong, highly branched Sn-doped zinc oxide (ZnO) nanostructures were fabricated using a simple substrate-free chemical vapor deposition (CVD) method. The nanostructures exhibited efficient photocatalytic activities in degradation of methylene blue (MB) under natural sunlight. 100% of MB with the concentration of 10 mg/L could be completely removed within 36 minutes. Possible reasons for the enhanced photocatalytic effect were analyzed.

  8. Modified optical fiber daylighting system with sunlight transportation in free space.

    Science.gov (United States)

    Vu, Ngoc-Hai; Pham, Thanh-Tuan; Shin, Seoyong

    2016-12-26

    We present the design, optical simulation, and experiment of a modified optical fiber daylighting system (M-OFDS) for indoor lighting. The M-OFDS is comprised of three sub-systems: concentration, collimation, and distribution. The concentration part is formed by coupling a Fresnel lens with a large-core plastic optical fiber. The sunlight collected by the concentration sub-system is propagated in a plastic optical fiber and then collimated by the collimator, which is a combination of a parabolic mirror and a convex lens. The collimated beam of sunlight travels in free space and is guided to the interior by directing flat mirrors, where it is diffused uniformly by a distributor. All parameters of the system are calculated theoretically. Based on the designed system, our simulation results demonstrated a maximum optical efficiency of 71%. The simulation results also showed that sunlight could be delivered to the illumination destination at distance of 30 m. A prototype of the M-OFDS was fabricated, and preliminary experiments were performed outdoors. The simulation results and experimental results confirmed that the M-OFDS was designed effectively. A large-scale system constructed by several M-OFDSs is also proposed. The results showed that the presented optical fiber daylighting system is a strong candidate for an inexpensive and highly efficient application of solar energy in buildings.

  9. An MFC capable of regenerating the cathodic electron acceptor under sunlight

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    A renewable MFC (microbial fuel cell) cathode was used in this study because the iodide ion could react with oxygen to generate triiodide under natural sunlight.The feasibility of the regeneration of triiodide ion under natural sunlight and the effect of the regenerated triiodide ion concentration on the MFC performance were studied.The results showed that the power density of the MFC using triiodide ion as cathodic electron acceptor was significantly higher than that of using ferricyanate,and that the iodide ion can be oxidized to triiodide ion by oxygen in air at the expense of natural sunlight.In addition,it was obvious from the experimental results that the MFC performance was improved with the increase of the triiodide concentration,indicating that the concentration of triiodide ion had a critical effect on the MFC performance.The linear sweep voltammetry (LSV) curves for the electro-reduction of triiodide ion on the carbon paper were obtained and the results suggested that the diffusion process of triiodide ions to cathode was the control factor for the MFC performance.

  10. Sunlight, ultraviolet radiation, vitamin D and skin cancer: how much sunlight do we need?

    Science.gov (United States)

    Holick, Michael F

    2014-01-01

    Vitamin D is the sunshine vitamin for good reason. During exposure to sunlight, the UV B photons enter the skin and photolyze 7-dehydrocholesterol to previtamin D3 which in turn is isomerized by the body's temperature to vitamin D3. Most humans have depended on sun for their vitamin D requirement. Skin pigment, sunscreen use, aging, time of day, season and latitude dramatically affect previtamin 13 synthesis. Vitamin D deficiency was thought to have been conquered, but it is now recognized that more than 50% of the world's population is at risk for vitamin D deficiency. This deficiency is in part due to the inadequate fortification of foods with vitamin D and the misconception that a healthy diet contains an adequate amount of vitamin D. Vitamin D deficiency causes growth retardation and rickets in children and will precipitate and exacerbate osteopenia, osteoporosis and increase risk of fracture in adults. The vitamin D deficiency has been associated pandemic with other serious consequences including increased risk of common cancers, autoimmune diseases, infectious diseases and cardiovascular disease. There needs to be a renewed appreciation of the beneficial effect of moderate sunlight for providing all humans with their vitamin D requirement for health.

  11. Sunlight-induced DNA damage in human mononuclear cells

    DEFF Research Database (Denmark)

    Møller, Peter; Wallin, Hakan; Holst, Erik

    2002-01-01

    of sunlight was comparable to the interindividual variation, indicating that sunlight exposure and the individual's background were the two most important determinants for the basal level of DNA damage. Influence of other lifestyle factors such as exercise, intake of foods, infections, and age could......In this study of 301 blood samples from 21 subjects, we found markedly higher levels of DNA damage (nonpyrimidine dimer types) in the summer than in the winter detected by single-cell gel electrophoresis. The level of DNA damage was influenced by the average daily influx of sunlight ... to blood sampling. The 3 and 6 day periods before sampling influenced DNA damage the most. The importance of sunlight was further emphasized by a positive association of the DNA damage level to the amount of time the subjects had spent in the sun over a 3 day period prior to the sampling. The effect...

  12. Direct and Indirect Phototransformation of Graphene Oxide in Sunlight

    Science.gov (United States)

    Direct and indirect (with added H202 that serves as OH precursor) photoreactions of grapheme oxide (GO) were examined under sunlight exposure. The results indicate that GO photoreacts under both conditions, leading to significant alterations in GO's physicochemical properties. In...

  13. Local Knitting Cluster: Concentrated for New Growth Model---Zaozhuang Held the First China Knitting Industry Cluster Annual Meeting%Local Knitting Cluster: Concentrated for New Growth Model---Zaozhuang Held the First China Knitting Industry Cluster Annual Meeting

    Institute of Scientific and Technical Information of China (English)

    Chen Xiangli

    2012-01-01

    Industry cluster is an economic phenomenon; that sees regionalized concentration of production here and there in the country. Currently, there are 14 pilot units of knitting industry clusters of which the production output exceeded 100 billion yuan in 2011. The industry cluster is divided into two categories;

  14. Geographical distribution of the annual mean radon concentrations in primary schools of Southern Serbia - application of geostatistical methods.

    Science.gov (United States)

    Bossew, P; Žunić, Z S; Stojanovska, Z; Tollefsen, T; Carpentieri, C; Veselinović, N; Komatina, S; Vaupotič, J; Simović, R D; Antignani, S; Bochicchio, F

    2014-01-01

    Between 2008 and 2011 a survey of radon ((222)Rn) was performed in schools of several districts of Southern Serbia. Some results have been published previously (Žunić et al., 2010; Carpentieri et al., 2011; Žunić et al., 2013). This article concentrates on the geographical distribution of the measured Rn concentrations. Applying geostatistical methods we generate "school radon maps" of expected concentrations and of estimated probabilities that a concentration threshold is exceeded. The resulting maps show a clearly structured spatial pattern which appears related to the geological background. In particular in areas with vulcanite and granitoid rocks, elevated radon (Rn) concentrations can be expected. The "school radon map" can therefore be considered as proxy to a map of the geogenic radon potential, and allows identification of radon-prone areas, i.e. areas in which higher Rn radon concentrations can be expected for natural reasons. It must be stressed that the "radon hazard", or potential risk, estimated this way, has to be distinguished from the actual radon risk, which is a function of exposure. This in turn may require (depending on the target variable which is supposed to measure risk) considering demographic and sociological reality, i.e. population density, distribution of building styles and living habits.

  15. Sunlight exposure-mediated DNA damage in young adults.

    Science.gov (United States)

    Kato, Masashi; Iida, Machiko; Goto, Yuji; Kondo, Takaaki; Yajima, Ichiro

    2011-08-01

    Previous experimental studies showed that single ultraviolet B (UVB) light irradiation increased levels of 8-hydroxy-2'-deoxyguanosine (8-OHdG), a well-established biomarker of carcinogenesis and oxidative DNA damage, in epithelial cells in animals and humans. We conducted for the first time an epidemiologic study to investigate the correlations among levels of oxidative DNA damage, skin pigmentation, and sunlight exposure in human daily life. Digitalized skin pigmentation levels and creatinine-adjusted urinary 8-OHdG levels were examined in 127 healthy young adults aged 20 to 24 years and in hairless mice with normal pigmented skin (HL-mice; n = 20) and hyperpigmented skin (HL-HPS-mice; n = 20). Data obtained by a questionnaire were also analyzed for the 127 subjects. Binary logistic regression analysis showed that increased sunlight intensity, but not sunlight-exposed time or sunlight-exposed skin area, was correlated with elevation in creatinine-adjusted urinary 8-OHdG levels. In contrast, increased skin pigmentation level, but not the use of sunscreen, was correlated with reduction in urinary 8-OHdG level in humans. UVB irradiation corresponding to several minutes of sunlight exposure significantly increased urinary 8-OHdG levels in HL-mice but not in HL-HPS-mice. We showed that increase in intensity of sunlight in human daily life increased levels of DNA damage. We also showed a protective effect of skin pigmentation on sunlight exposure-mediated DNA damage. We have provided more reliable evidence of routine sunlight exposure-mediated DNA damage in humans through the combination of epidemiologic and experimental studies. ©2011 AACR.

  16. The role of climate and human changes on inter-annual variation in stream nitrate fluxes and concentrations

    Science.gov (United States)

    Philippe, M.; Gascuel, C.; Pierre, A.; Patrick, D.; Laurent, R.; Jérome, M.

    2010-12-01

    In recent decades, temporal variations in nitrate fluxes and concentrations in temperate rivers have resulted from the interaction of anthropogenic and climatic factors. The effect of climatic drivers remains unclear, while the relative importance of the drivers seems to be highly site dependent. This paper focuses on 2-6 years variations called meso-scale variations, and analyses the climatic drivers of these variations in a study site characterized by high N inputs from intensive animal farming systems and shallow aquifers with impervious bedrock in a temperate climate. Three approaches are developed: 1) an analysis of long-term records (30-40 years) of nitrate fluxes and nitrate concentrations in 30 coastal rivers of Western France, which were well-marked by meso-scale cycles in the fluxes and concentration with a slight hysteresis; 2) a test of the climatic control using a lumped two box model, which demonstrates that hydrological assumptions are sufficient to explain these meso-scale cycles; and 3) a model of nitrate fluxes and concentrations in two contrasted catchments subjected to recent mitigation measures, which analyses nitrate fluxes and concentrations in relation to N stored in groundwater. In coastal rivers, hydrological drivers (i.e., effective rainfall), and particularly the dynamics of the water table and rather stable nitrate concentration, explain the meso-scale cyclic patterns. In the headwater catchment, agricultural and hydrological drivers can interact according their settings. The requirements to better distinguish the effect of climate and human changes in integrated water management are addressed: long term monitoring, coupling the analysis and the modelling of large sets of catchments incorporating different sizes, land uses and environmental factors. (Figure : Discharge, nitrate concentrations and fluxes in the Aulne river from 1973 to 2007.)

  17. Sunlight exposure and multiple sclerosis in a tropical country.

    Science.gov (United States)

    Espinosa-Ramírez, Guillermo; Ordoñez, Graciela; Flores-Rivera, Jose; Sotelo, Julio

    2014-07-01

    We analysed past and current sun exposure in multiple sclerosis (MS) patients as compared with matched controls in Mexico, a country with tropical climate. In a case-controlled study that include 83 MS patients and 166 matched controls, we inquired about sunlight exposure in two different periods: during adolescence and during the immediate past 5 years. Indicators were: exposure on quotidian and weekend outdoor activities with direct sunlight contact as expressed on frequency by mean number of days, daytime (morning, noon, afternoon), number of hours, visits to sunny places, and use of sunblocking agents. Additional elements were socioeconomic status, skin colour, and antecedent of varicella infection during childhood. MS patients showed a larger proportion of white skin. MS patients had more sunlight exposure during adolescence (80% versus 60%, P = 0·002); this tendency prevailed on current indicators (46% versus 30%, P = 0·02). However, current exposure on weekends (10% versus 22%, P = 0·02) and visits to the beach (64% versus 98%, P = 0·002) were lower in MS than in controls. Mexico gets more sunlight through the year than areas with high incidence of MS; nevertheless, its prevalence has greatly increased over the last decades, making it a relevant emerging disease. Our results indicate that in a tropical country, there is no association between sunlight exposure and the risk to develop MS, given the immunological effects of sunlight exposure either through UV radiation or vitamin D metabolism.

  18. Effects of nitrogen and biochar amendment on soil methane concentration profiles and diffusion in a rice-wheat annual rotation system

    Science.gov (United States)

    Xu, Xin; Wu, Zhen; Dong, Yubing; Zhou, Ziqiang; Xiong, Zhengqin

    2016-12-01

    The CH4 emissions from soil were influenced by the changeable CH4 concentrations and diffusions in soil profiles, but that have been subjected to nitrogen (N) and biochar amendment over seasonal and annual time frames. Accordingly, a two-year field experiment was conducted in southeastern China to determine the amendment effects on CH4 concentrations and diffusive effluxes as measured by a multilevel sampling probe in paddy soil during two cycles of rice-wheat rotations. The results showed that the top 7-cm soil layers were the primary CH4 production sites during the rice-growing seasons. This layer acted as the source of CH4 generation and diffusion, and the deeper soil layers and the wheat season soil acted as the sink. N fertilization significantly increased the CH4 concentration and diffusive effluxes in the top 7-cm layers during the 2013 and 2014 rice seasons. Following biochar amendment, the soil CH4 concentrations significantly decreased during the rice season in 2014, relative to the single N treatment. Moreover, 40 t ha-1 biochar significantly decreased the diffusive effluxes during the rice seasons in both years. Therefore, our results showed that biochar amendment is a good strategy for reducing the soil profile CH4 concentrations and diffusive effluxes induced by N in paddy fields.

  19. Sunlight-activated AlFeO3/TiO2 photocatalyst

    Institute of Scientific and Technical Information of China (English)

    YUAN; Zhihao; WANG; Yuhong; SUN; Yongchang; WANG; Jing; BIE; Lijian; DUAN; Yueqing

    2006-01-01

    A nanocomposite photocatalyst composed of AlFeO3 and TiO2 is prepared, and characterized through X-ray diffraction. Application of the nanocomposite for the photodegradations of eosin dye and methyl orange gives an improved photoactivity compared with TiO2-only nanomaterials. The optimal concentration of AlFeO3 in the composite is about 1.0 wt% under UV excitation, and 9.0 wt% under sunlight excitation for the improved photoactivity. Furthermore, this nanocomposite is more active for eosin photodegradation if natural sunlight rather than UV is used. This may be due to the reason that adding AlFeO3 nanoparticles into TiO2 matrix can promote the separation of photogenerated charge carriers, and extend the photoresponse of TiO2 toward visible region, which results in an increase in the solar energy utilization efficiency.

  20. Annual changes in fecal estradiol-17beta concentrations of the sun bear (Helarctos malayanus) in Sarawak, Malaysia.

    Science.gov (United States)

    Onuma, Manabu; Suzuki, Masatsugu; Uchida, Eiji; Niiyama, Masami; Ohtaishi, Noriyuki

    2002-04-01

    Fecal estradiol concentrations were measured in three captive unmated female sun bears (Helarctos malayanus) from August 1998 to July 1999 in Sarawak, Malaysia and vaginal smears from one of the females was observed in August 1998 and March 1999. A single peak in fecal estradiol concentration was obvious for each bear in August or September 1998, and there was a much higher percentage of superficial vaginal anuclear cells in August 1998 than in March 1999. These results suggest that sun bears in Sarawak are likely to be a seasonal breeder associated with a peak of estrogen production in August or September.

  1. Recommended summer sunlight exposure amounts fail to produce sufficient vitamin D status in UK adults of South Asian origin.

    Science.gov (United States)

    Farrar, Mark D; Kift, Richard; Felton, Sarah J; Berry, Jacqueline L; Durkin, Marie T; Allan, Donald; Vail, Andy; Webb, Ann R; Rhodes, Lesley E

    2011-11-01

    The cutaneous synthesis of vitamin D is dependent on UVB from sunlight, but melanin reduces the penetration of UVB and thus contributes to vitamin D insufficiency in individuals with darker skin. The national guidance provided on amounts of sunlight exposure in the United Kingdom is for the light-skinned population, and in the absence of dedicated information, darker-skinned people may attempt to follow this guidance. We determined the relative effect of a simulation of UK recommendations of summer sunlight exposure on the vitamin D status of individuals of South Asian ethnicity compared with that of whites. In a prospective cohort study, simulated summer sunlight exposures were provided under rigorous dosimetric conditions to 15 adults (aged 20-60 y) of South Asian ethnicity, and serum 25-hydroxyvitamin D [25(OH)D] was measured weekly. Dietary vitamin D intake was estimated. Outcomes were compared with those of 109 whites (aged 20-60 y) treated with the identical UV-radiation exposure protocol. At baseline (winter trough), all South Asians were vitamin D-insufficient [25(OH)D concentrations Sunlight-exposure recommendations are inappropriate for individuals of South Asian ethnicity who live at the UK latitude. More guidance is required to meet the vitamin D requirements of this sector of the population. This study was registered at www.isrctn.org as ISRCTN 07565297.

  2. Characterization of plasma vitellogenin and sex hormone concentrations during the annual reproductive cycle of the endangered razorback sucker

    Science.gov (United States)

    Hinck, Jo Ellen; Papoulias, Diana M.; Annis, Mandy L.; Tillitt, Donald E.; Marr, Carrie; Denslow, Nancy D.; Kroll, Kevin J.; Nachtmann, Jason

    2011-01-01

    Population declines of the endangered razorback sucker Xyrauchen texanus in the Colorado River basin have been attributed to predation by and competition with nonnative fishes, habitat alteration, and dam construction. The reproductive health and seasonal variation of the reproductive end points of razorback sucker populations are currently unknown. Using nonlethal methods, we characterized the plasma hormonal fluctuations of reproductively mature female and male razorback suckers over a 12-month period in a hatchery by measuring their vitellogenin (VTG) and three sex hormones: 17β-estradiol (E2), testosterone (T), and 11-ketotestosterone (KT). Fish were identified as reproductive or nonreproductive based on their body weight, VTG, and sex hormone profiles. In reproductive females, the E2 concentration increased in the fall and winter, and increases in T and VTG concentrations were generally associated with the spawning period. Mean T concentrations were consistently greater in reproductive females than in nonreproductive females, but this pattern was even more pronounced during the spawning period (spring). Consistently low T concentrations (health and condition may be particularly important to recovery efforts of razorback suckers given that the few remaining wild populations are located in a river where water quality and quantity issues are well documented. In addition to the size, age, and recruitment information currently considered in the recovery goals of this endangered species, reproductive end points could be included as recovery metrics with which to monitor seasonal trends and determine whether repatriated populations are cycling naturally.

  3. Sunlight decreased genotoxicity of azadirachtin on root tip cells of Allium cepa and Eucrosia bicolor.

    Science.gov (United States)

    Kwankua, W; Sengsai, S; Kuleung, C; Euawong, N

    2010-07-01

    Utilization of neem plant (Azadirachta indica A. Juss) extract for pest control in agriculture has raised concerns over contamination by the residues to the environment. Such residues, particularly azadirachtin (Aza), may cause deleterious effect to non-target organisms. This investigation was conducted to find out if Aza could be inactivated through exposures to sunlight. Activity of Aza was assessed as its ability to cause cytotoxic and genotoxic effects in the forms of nuclei abnormality and chromosome aberration as measured by mitotic index (MI) and mitotic aberration (MA). Varying concentrations of Aza were tested on Allium cepa and Eucrosia bicolor. It was found that the MI of all root tip meristematic cells of A. cepa and E. bicolor treated with 0.00005%, 0.00010%, 0.00015%, and 0.00020% (w/v) Aza-containing neem extract for 24h, were significantly lower than the controls. Complementary to the lower levels of MI, the Aza-treated groups showed higher MA levels in all cases investigated. Furthermore, the decreasing levels of MI and the increasing levels of MA related well with the increasing concentration of Aza. Microscopic examination of root tip meristematic cells revealed that the anomaly found most often were mitotic disturbances and chromosomal bridges. Exposures of 0.00020% (w/v) Aza to sunlight for 3 days and 7 days decreased Aza ability to induce cytotoxicity and genotoxicity, both in terms of MI and MA, to root tip meristematic cells in A. cepa and E. bicolor. Photodegradation of Aza upon exposure to direct sunlight was confirmed by HPLC. The study implicates that Aza would unlikely cause long term deleterious effects to the environment since it would be inactivated by sunlight. Copyright (c) 2010 Elsevier Inc. All rights reserved.

  4. Intra- and inter-annual uranium concentration variability in a Belizean stalagmite controlled by prior aragonite precipitation: A new tool for reconstructing hydro-climate using aragonitic speleothems

    Science.gov (United States)

    Jamieson, Robert A.; Baldini, James U. L.; Brett, Marianne J.; Taylor, Jessica; Ridley, Harriet E.; Ottley, Chris J.; Prufer, Keith M.; Wassenburg, Jasper A.; Scholz, Denis; Breitenbach, Sebastian F. M.

    2016-10-01

    Aragonitic speleothems are increasingly utilised as palaeoclimate archives due to their amenability to high precision U-Th dating. Proxy records from fast-growing aragonitic stalagmites, precisely dated to annual timescales, can allow investigation of climatic events occurring on annual or even sub-annual timescales with minimal chronological uncertainty. However, the behaviour of many trace elements, such as uranium, in aragonitic speleothems has not thus far been as well constrained as in calcitic speleothems. Here, we use uranium concentration shifts measured across primary calcite-to-aragonite mineralogical transitions in speleothems to calculate the distribution coefficient of uranium in aragonitic speleothems (derived DU = 3.74 ± 1.13). Because our calculated DU is considerably above 1 increased prior aragonite precipitation due to increased karst water residence time should strongly control stalagmite aragonite U/Ca values. Consequently, uranium concentrations in aragonitic speleothems should act as excellent proxies for effective rainfall. We test this using a high-resolution ICP-MS derived trace element dataset from a Belizean stalagmite. YOK-G is an aragonitic stalagmite from Yok Balum cave in Belize with an extremely robust monthly-resolved chronology built using annual δ13C cycles. We interpret seasonal U/Ca variations in YOK-G as reflecting changes in the amount and seasonality of prior aragonite precipitation driven by variable rainfall amounts. The U/Ca record strongly suggests that modern drying has occurred in Belize, and that this drying was primarily caused by a reduction in wet season rainfall. This is consistent with published stable isotope data from YOK-G also very strongly suggesting modern rainfall reductions, previously interpreted as the result of southward ITCZ displacement. Our results strongly suggest that U/Ca values in aragonitic speleothems are excellent proxies for rainfall variability. This new tool, combined with the

  5. Sunlight-induced photochemical decay of oxidants in natural waters: implications in ballast water treatment.

    Science.gov (United States)

    Cooper, William J; Jones, Adam C; Whitehead, Robert F; Zika, Rod G

    2007-05-15

    The transport and discharge of ship ballast water has been recognized as a major vector for the introduction of invasive species. Chemical oxidants, long used in drinking water and wastewater treatment, are alternative treatment methods for the control of invasive species currently being tested for use on ships. One concern when a ballasted vessel arrives in port is the adverse effects of residual oxidant in the treated water. The most common oxidants include chlorine (HOCl/OCl-), bromine (HOBr/OBr-), ozone (03), hydrogen peroxide (H2O2), chlorine dioxide (ClO2), and monochloramine (NH2Cl). The present study was undertaken to evaluate the sunlight-mediated photochemical decomposition of these oxidants. Sunlight photodecomposition was measured at various pH using either distilled water or oligotrophic Gulf Stream water for specific oxidants. For selected oxidants, quantum yields at specific wavelengths were obtained. An environmental photochemical model, GCSOLAR, also provided predictions of the fate (sunlight photolysis half-lives) of HOCI/OCl-, HOBr/OBr-, ClO2, and NH2Cl for two different seasons at latitude 40 degrees and in water with two different concentrations of chromophoric dissolved organic matter. These data are useful in assessing the environmental fate of ballast water treatment oxidants if they were to be discharged in port.

  6. Improved Flexible Transparent Conductive Electrodes based on Silver Nanowire Networks by a Simple Sunlight Illumination Approach

    Science.gov (United States)

    Kou, Pengfei; Yang, Liu; Chang, Cheng; He, Sailing

    2017-01-01

    Silver nanowire (Ag NW) networks have attracted wide attention as transparent electrodes for emerging flexible optoelectronics. However, the sheet resistance is greatly limited by large wire-to-wire contact resistances. Here, we propose a simple sunlight illumination approach to remarkably improve their electrical conductivity without any significant degradation of the light transmittance. Because the power density is extremely low (0.1 W/cm2, 1-Sun), only slight welding between Ag NWs has been observed. Despite this, a sheet resistance of <20 Ω/sq and transmittance of ~87% at wavelength of 550 nm as well as excellent mechanical flexibility have still been achieved for Ag NW networks after sunlight illumination for 1 hour or longer, which are significant upgrades over those of ITO. Slight plasmonic welding together with the associated self-limiting effect has been investigated by numerical simulations and further verified experimentally through varied solar concentrations. Due to the reduced resistance, high-performance transparent film heaters as well as efficient defrosters have been demonstrated, which are superior to the previously-reported Ag NW based film heaters. Since the sunlight is environmentally friendly and easily available, sophisticated or expensive facilities are not necessary. Our findings are particularly meaningful and show enormous potential for outdoor applications. PMID:28169343

  7. Combined Application of Natural Sunlight and Hydrogen peroxide on the Removal of Harmful Cyanobacteria

    Science.gov (United States)

    Wang, D. H.; Li, L.; Zhu, C. W.; Wang, Z. Y.; Xie, P.

    2017-08-01

    This study provides an efficient and environmentally friendly advanced oxidation technique involving the combined application of natural sunlight and hydrogen peroxide for the removal of harmful cyanobacteria from lakes and reservoirs. In this paper, we collected water samples from Taihu Lake (Wuxi, China) in August 2016 when cyanobacterial blooms had occurred and then performed an outdoor experiment. Hydrogen peroxide at 0.6 mM had no obvious effect on the cyanobacterial inactivation in the dark, even stimulating cyanobacterial growth to some extent. Cyanobacteria were inactivated by higher concentrations of hydrogen peroxide (1.0 mM) in the dark, as well as 0.4 mM hydrogen peroxide under sunlight irradiation, indicating that natural sunlight significantly enhanced the effect of hydrogen peroxide on the removal of cyanobacteria. An experiment involving Pseudanabaena sp. (a harmful species) led to similar conclusions as the study using algae attained from Taihu Lake. This study provides a practical and effective method for controlling harmful cyanobacteria in natural water bodies.

  8. Life-threatening motor vehicle crashes in bright sunlight.

    Science.gov (United States)

    Redelmeier, Donald A; Raza, Sheharyar

    2017-01-01

    Bright sunlight may create visual illusions that lead to driver error, including fallible distance judgment from aerial perspective. We tested whether the risk of a life-threatening motor vehicle crash was increased when driving in bright sunlight.This longitudinal, case-only, paired-comparison analysis evaluated patients hospitalized because of a motor vehicle crash between January 1, 1995 and December 31, 2014. The relative risk of a crash associated with bright sunlight was estimated by evaluating the prevailing weather at the time and place of the crash compared with the weather at the same hour and location on control days a week earlier and a week later.The majority of patients (n = 6962) were injured during daylight hours and bright sunlight was the most common weather condition at the time and place of the crash. The risk of a life-threatening crash was 16% higher during bright sunlight than normal weather (95% confidence interval: 9-24, P vehicle crash. An awareness of this risk might inform driver education, trauma staffing, and safety warnings to prevent a life-threatening motor vehicle crash.

  9. Hair cortisol and cortisone are decreased by natural sunlight.

    Science.gov (United States)

    Wester, Vincent L; van der Wulp, Nils R P; Koper, Jan W; de Rijke, Yolanda B; van Rossum, Elisabeth F C

    2016-10-01

    Hair glucocorticoids (cortisol and cortisone) are increasingly used as measures of long-term integrated exposure to glucocorticoid hormones. Glucocorticoids gradually disappear from the hair shaft, which may result from exposure to ultraviolet (UV) radiation in natural sunlight. We aimed to study the influence of sun exposure on hair glucocorticoids. Scalp hair samples were obtained from nine volunteers (median age 33 [range 21-81], 7 females), and part of each hair sample was exposed to three experimental conditions: repeated exposure to natural sunlight for 40h (natural UV), exposure to a high amount of artificial UV radiation, and storage in the dark (control). Hair cortisol (HairF) and cortisone (HairE) were quantified by liquid chromatography-tandem mass spectrometry. When compared to control, HairF was decreased in 9 out of 9 hair samples after natural sunlight exposure (median decrease -3.1pg/mg or -54%, PUV radiation (-4.7pg/mg or -75%, P=0.003). HairE decreased in 8 out of 9 samples, both after natural sunlight (-7.6pg/mg or -32%, P=0.012) and artificial UV (-10.7pg/mg or -52%, P=0.026). Exposure to natural sunlight decreases the glucocorticoid content of scalp hair, apparently through UV radiation, and is therefore an important confounder that should be considered in studies involving the measurement of hair glucocorticoids. Copyright © 2016 Elsevier Ltd. All rights reserved.

  10. Stability of Bacillus thuringiensis and NPV Microencapsulated Formulation under Sunlight

    Directory of Open Access Journals (Sweden)

    Samaneh Sadat Naghavi

    2016-06-01

    Full Text Available Microencapsulation technology is used for the formulation of bio pesticides and is effective against the ultra-violet radiation of sunlight. The present research studied the stability of Bt and NPV formulations microencapsulated with gelatin and sodium alginate, individually or in combination. The formulations were evaluated in outdoor space and under sunlight on potted growing cabbage. The stability of each active ingredient tested in each formulation was studied at 0, 3, 7 and 10 days after spraying on cabbage infested with diamondback moth Plutella xylostella second instars larvae. Results showed that non-formulated and microencapsulated formulations not exposed to sunlight (time zero had similar mortality. However, after being exposed to sunlight for three days, the non-formulated Bt and NPV resulted in a significantly lower mortality (less than 40%; compared with the microencapsulated bio pesticides (more than 70% mortality. Fifty percent (50% mortality was reached in microencapsulated formulations after seven and ten days of exposure to sunlight, whereas there was no mortality in larvae exposed to unformulated treated plants after ten days. ANOVA analysis showed the highest larval mortality was achieved by the Bt+NPV gelatin microencapsulated formulation followed by gelatin coated Bt, sodium alginate coated NPV, sodium alginate coated Bt+NPV, gelatin coated NPV and sodium alginate coated Bt. The formulations showed no significant LT50 differences between microencapsulated versus unformulated Bt and NPV.

  11. Photo-induced toxicity of titanium dioxide nanoparticles to Daphnia magna under natural sunlight.

    Science.gov (United States)

    Mansfield, C M; Alloy, M M; Hamilton, J; Verbeck, G F; Newton, K; Klaine, S J; Roberts, A P

    2015-02-01

    Titanium dioxide nanoparticles (TiO2 NP) are one of the most abundantly utilized nanoparticles in the world. Studies have demonstrated the ability of the anatase crystal of TiO2 NP to produce reactive oxygen species (ROS) in the presence of ultraviolet radiation (UVR), a co-exposure likely to occur in aquatic ecosystems. The goal of this study was to examine the photo-induced toxicity of anatase TiO2 NP under natural sunlight to Daphnia magna. D. magna were exposed to a range of UVR intensities and anatase TiO2 concentrations in an outdoor exposure system using the sun as the source of UVR. Different UVR intensities were achieved using UVR opaque and transparent plastics. AnataseTiO2-NP demonstrated the reciprocal relationship seen in other phototoxic compounds such as polycyclic aromatic hydrocarbons (PAHs) at higher UVR treatments. The calculated 8h LC50 of anatase TiO2 NP was 139 ppb under full intensity ambient natural sunlight, 778 ppb under 50% natural sunlight, and >500 ppm under 10% natural sunlight. Mortality was also compared between animals allowed to accumulate a body burden of anatase TiO2 for 1h and organisms whose first exposure to anatase TiO2 aqueous suspensions occurred under UVR. A significantly greater toxic effect was observed in aqueous, low body burden suspensions than that of TiO2 1h body burdens, which is dissimilar from the model presented in PAHs. Anatase TiO2 presents a unique photo-induced toxic model that is different than that of established phototoxic compounds.

  12. Estradiol concentration and the expression of estrogen receptors in the testes of the domestic goose (Anser anser f. domestica) during the annual reproductive cycle.

    Science.gov (United States)

    Leska, A; Kiezun, J; Kaminska, B; Dusza, L

    2015-04-01

    Seasonal fluctuations in the activity of bird testes are regulated by a complex mechanism where androgens play a key role. Until recently, the role played by estrogens in males has been significantly underestimated. However, there is growing evidence that the proper functioning of the testes is associated with optimal estradiol (E2) concentration in both the plasma and testes of many mammalian species. Estrogens are gradually emerging as very important players in hormonal regulation of reproductive processes in male mammals. Despite the previously mentioned, it should be noted that estrogenic action is limited by the availability of specific receptors--estrogen receptor alpha (ERα) and estrogen receptor beta (ERβ). Interestingly, there is a general scarcity of information concerning the estrogen responsive system in the testes of male birds, which is of particular interest in exploring the phenomenon of seasonality of reproduction. To address this question, we have investigated for the first time the simultaneous expression of testicular ERα and ERβ genes and proteins with the accompanying plasma and testicular E2 concentrations during the annual reproductive cycle of male bird. The research model was the domestic goose (Anser anser f. domestica), a species whose annual reproductive cycle can be divided into 3 distinct phases characterized by changes in testicular activity. It has been revealed that the stable plasma E2 profile did not correspond to changing intratesticular E2 profile throughout the experiment. The expression of ERα and ERβ genes and proteins was detected in gander testes and it fluctuated on a seasonal basis with lower level in breeding and sexual reactivation stages and higher level during the nonbreeding stage. Our results demonstrated changes in testicular sensitivity to estrogens in male domestic goose during the annual reproductive cycle. The seasonal pattern of estrogen receptors (ERs) expression was analyzed against the hormonal

  13. Carbon nanohorns-based nanofluids as direct sunlight absorbers.

    Science.gov (United States)

    Sani, E; Barison, S; Pagura, C; Mercatelli, L; Sansoni, P; Fontani, D; Jafrancesco, D; Francini, F

    2010-03-01

    The optimization of the poor heat transfer characteristics of fluids conventionally employed in solar devices are at present one of the main topics for system efficiency and compactness. In the present work we investigated the optical and thermal properties of nanofluids consisting in aqueous suspensions of single wall carbon nanohorns. The characteristics of these nanofluids were evaluated in view of their use as sunlight absorber fluids in a solar device. The observed nanoparticle-induced differences in optical properties appeared promising, leading to a considerably higher sunlight absorption. We found that the thermal conductivity of the nanofluids was higher than pure water. Both these effects, together with the possible chemical functionalization of carbon nanohorns, make this new kind of nanofluids very interesting for increasing the overall efficiency of the sunlight exploiting device.

  14. Life-threatening motor vehicle crashes in bright sunlight

    Science.gov (United States)

    Redelmeier, Donald A.; Raza, Sheharyar

    2017-01-01

    Abstract Bright sunlight may create visual illusions that lead to driver error, including fallible distance judgment from aerial perspective. We tested whether the risk of a life-threatening motor vehicle crash was increased when driving in bright sunlight. This longitudinal, case-only, paired-comparison analysis evaluated patients hospitalized because of a motor vehicle crash between January 1, 1995 and December 31, 2014. The relative risk of a crash associated with bright sunlight was estimated by evaluating the prevailing weather at the time and place of the crash compared with the weather at the same hour and location on control days a week earlier and a week later. The majority of patients (n = 6962) were injured during daylight hours and bright sunlight was the most common weather condition at the time and place of the crash. The risk of a life-threatening crash was 16% higher during bright sunlight than normal weather (95% confidence interval: 9–24, P < 0.001). The increased risk was accentuated in the early afternoon, disappeared at night, extended to patients with different characteristics, involved crashes with diverse features, not apparent with cloudy weather, and contributed to about 5000 additional patient-days in hospital. The increased risk extended to patients with high crash severity as indicated by ambulance involvement, surgical procedures, length of hospital stay, intensive care unit admission, and patient mortality. The increased risk was not easily attributed to differences in alcohol consumption, driving distances, or anomalies of adverse weather. Bright sunlight is associated with an increased risk of a life-threatening motor vehicle crash. An awareness of this risk might inform driver education, trauma staffing, and safety warnings to prevent a life-threatening motor vehicle crash. Level of evidence: Epidemiologic Study, level III. PMID:28072708

  15. Successful pacing using a batteryless sunlight-powered pacemaker.

    Science.gov (United States)

    Haeberlin, Andreas; Zurbuchen, Adrian; Schaerer, Jakob; Wagner, Joerg; Walpen, Sébastien; Huber, Christoph; Haeberlin, Heinrich; Fuhrer, Juerg; Vogel, Rolf

    2014-10-01

    Today's cardiac pacemakers are powered by batteries with limited energy capacity. As the battery's lifetime ends, the pacemaker needs to be replaced. This surgical re-intervention is costly and bears the risk of complications. Thus, a pacemaker without primary batteries is desirable. The goal of this study was to test whether transcutaneous solar light could power a pacemaker. We used a three-step approach to investigate the feasibility of sunlight-powered cardiac pacing. First, the harvestable power was estimated. Theoretically, a subcutaneously implanted 1 cm(2) solar module may harvest ∼2500 µW from sunlight (3 mm implantation depth). Secondly, ex vivo measurements were performed with solar cells placed under pig skin flaps exposed to a solar simulator and real sunlight. Ex vivo measurements under real sunlight resulted in a median output power of 4941 µW/cm(2) [interquartile range (IQR) 3767-5598 µW/cm(2), median skin flap thickness 3.0 mm (IQR 2.7-3.3 mm)]. The output power strongly depended on implantation depth (ρSpearman = -0.86, P pacemaker powered by a 3.24 cm(2) solar module was implanted in vivo in a pig to measure output power and to pace. In vivo measurements showed a median output power of >3500 µW/cm(2) (skin flap thickness 2.8-3.84 mm). Successful batteryless VVI pacing using a subcutaneously implanted solar module was performed. Based on our results, we estimate that a few minutes of direct sunlight (irradiating an implanted solar module) allow powering a pacemaker for 24 h using a suitable energy storage. Thus, powering a pacemaker by sunlight is feasible and may be an alternative energy supply for tomorrow's pacemakers. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2014. For permissions please email: journals.permissions@oup.com.

  16. Photocatalytic degradation of humic substances in aqueous solution using Cu-doped ZnO nanoparticles under natural sunlight irradiation.

    Science.gov (United States)

    Maleki, Afshin; Safari, Mahdi; Shahmoradi, Behzad; Zandsalimi, Yahya; Daraei, Hiua; Gharibi, Fardin

    2015-11-01

    In this study, Cu-doped ZnO nanoparticles were investigated as an efficient synthesized catalyst for photodegradation of humic substances in aqueous solution under natural sunlight irradiation. Cu-doped ZnO nanocatalyst was prepared through mild hydrothermal method and was characterized using FT-IR, powder XRD and SEM techniques. The effect of operating parameters such as doping ratio, initial pH, catalyst dosage, initial concentrations of humic substances and sunlight illuminance were studied on humic substances degradation efficiency. The results of characterization analyses of samples confirmed the proper synthesis of Cu-doped ZnO nanocatalyst. The experimental results indicated the highest degradation efficiency of HS (99.2%) observed using 1.5% Cu-doped ZnO nanoparticles at reaction time of 120 min. Photocatalytic degradation efficiency of HS in a neutral and acidic pH was much higher than that at alkaline pH. Photocatalytic degradation of HS was enhanced with increasing the catalyst dosage and sunlight illuminance, while increasing the initial HS concentration led to decrease in the degradation efficiency of HS. Conclusively, Cu-doped ZnO nanoparticles can be used as a promising and efficient catalyst for degradation of HS under natural sunlight irradiation.

  17. Practical implementation of a planar micro-optic solar concentrator

    Science.gov (United States)

    Baker, Katherine; Karp, Jason; Hallas, Justin; Ford, Joseph

    2012-10-01

    CPV optics typically have multiple discrete apertures which each focus sunlight directly onto an associated PV cell. Waveguide based CPV systems instead couple light from multiple small apertures through a shared slab waveguide, avoiding individual optical alignment and electrical connection of multiple PV cells. We previously demonstrated the design and fabrication of a planar micro-optic waveguide concentrator, where incoming sunlight is focused through millimeter pitch lenslets onto mirrored micro-prisms which couple light into a slab waveguide toward common PV cells. This enables an efficient high concentrator system with a compact geometry. However, this design has the typical CPV limitation of low angular acceptance, requiring precise two-axis large-scale mechanical tracking. Here, we present the results of a design study to adapt the planar micro-optic design for use in combination with a one-dimensional mechanical tracker, tilted at latitude, to provide azimuthal alignment and altitude bias. Lateral mechanical micro-tracking can accommodate the residual altitude misalignment. The design shows that this relatively simple system can still provide over 72% annual optical efficiency for a 50x concentrator. Replacing the micro-tracking with passive optical altitude alignment further reduces system complexity, but also reduces efficiency. These waveguide based concentrators have primarily been designed for use with photovoltaic cells, which are index matched onto the waveguide either directly, or through output couplers. For concentrating solar power systems, sunlight is focused onto thermally isolated devices which can not be in direct contact. We will also present alternative output coupler designs, which allow extraction of light from the waveguide to an air or vacuum isolated coupler. The loss associated with these couplers is substantially identical to the reflection losses of one additional mirror.

  18. 太阳辐射高效聚集与镜场时空协同理论研究%Theory of Efficient Concentration of the Solar Radiation and Optimization of the Concentrator Field-annual report

    Institute of Scientific and Technical Information of China (English)

    卢振武; 魏秀东

    2016-01-01

    All study tasks have been completed in this year. 4 papers have been published. The software for the optimization of the concentrator field has been improved. The annual power generation capacity of the solar plant can be calculated based on the solar direct radiation resources. The flux distribution at the absorber wall can be calculated. The heliostat field partition control mechanisms have been established to achieve cooperation of the radiation concentration and heat absorption. The installation and commission of the new concentrator have been finished. The surface shape measurement methods for the concentrator have been proposed. The feasibility of the methods has been evaluated by experiments. The optical performance testing methods studies for concentrator have been finished. The concentrator optical performance testing method has been proposed and the equipment and testing software have been developed. The testing method studies for the tracking accuracy of the concentrator have been completed. The tracking testing experiments have been finished. The performance of the concentrator has been evaluated.%研究完成了该年度的全部预期目标,完善了太阳能热发电镜场时空协同设计软件,可根据太阳直射辐射资源计算电站年发电量;可计算吸热器管壁的能流分布,解决了镜场聚光与吸热协同优化设计问题,建立镜场分区控制机制,达到聚光与吸热协同;完成了聚光器的外场安装与调试,提出了聚光器面形检测方法,并对检测方法的可行性进行了试验研究;完成了聚光器的光学性能测试方法研究,提出了聚光器光学性能测试设备研制方案;完成了聚光器外场跟踪精度测试方法研究,并进行了跟踪精度测试试验;完成了聚光器的综合性能初步评价。

  19. Application of dimensionless sediment rating curves to predict suspended-sediment concentrations, bedload, and annual sediment loads for rivers in Minnesota

    Science.gov (United States)

    Ellison, Christopher A.; Groten, Joel T.; Lorenz, David L.; Koller, Karl S.

    2016-10-27

    Consistent and reliable sediment data are needed by Federal, State, and local government agencies responsible for monitoring water quality, planning river restoration, quantifying sediment budgets, and evaluating the effectiveness of sediment reduction strategies. Heightened concerns about excessive sediment in rivers and the challenge to reduce costs and eliminate data gaps has guided Federal and State interests in pursuing alternative methods for measuring suspended and bedload sediment. Simple and dependable data collection and estimation techniques are needed to generate hydraulic and water-quality information for areas where data are unavailable or difficult to collect.The U.S. Geological Survey, in cooperation with the Minnesota Pollution Control Agency and the Minnesota Department of Natural Resources, completed a study to evaluate the use of dimensionless sediment rating curves (DSRCs) to accurately predict suspended-sediment concentrations (SSCs), bedload, and annual sediment loads for selected rivers and streams in Minnesota based on data collected during 2007 through 2013. This study included the application of DSRC models developed for a small group of streams located in the San Juan River Basin near Pagosa Springs in southwestern Colorado to rivers in Minnesota. Regionally based DSRC models for Minnesota also were developed and compared to DSRC models from Pagosa Springs, Colorado, to evaluate which model provided more accurate predictions of SSCs and bedload in Minnesota.Multiple measures of goodness-of-fit were developed to assess the effectiveness of DSRC models in predicting SSC and bedload for rivers in Minnesota. More than 600 dimensionless ratio values of SSC, bedload, and streamflow were evaluated and delineated according to Pfankuch stream stability categories of “good/fair” and “poor” to develop four Minnesota-based DSRC models. The basis for Pagosa Springs and Minnesota DSRC model effectiveness was founded on measures of goodness

  20. Carbon nanofibers, precious commodities from sunlight & CO2 to ameliorate global warming

    CERN Document Server

    Licht, Stuart

    2015-01-01

    This study introduces the high yield, electrolytic synthesis of carbon nanofibers, CNFs, directly from carbon dioxide. Production of a precious commodity such as CNFs from atmospheric carbon dioxide provides impetus to limit this greenhouse gas and mitigate the rate of climate change. CNFs are formed at high rate using inexpensive nickel and steel electrodes in molten electrolytes. The process is demonstrated as a scaled-up stand-alone electrolytic cell, and is also shown compatible with the STEP, solar thermal electrochemical process, using concentrated sunlight at high solar to electric efficiency to provide the heat and electrical energy to drive the CNF production.

  1. Lack of sunlight exposure influence on primary glioblastoma survival.

    Science.gov (United States)

    Mutlu, Hasan; Akca, Zeki; Erden, Abdulsamet; Aslan, Tuncay; Ucar, Kadir; Kaplan, Bunyamin; Buyukcelik, Abdullah

    2014-01-01

    The prognosis of primary glioblastoma (GBM) is poor. Approximately 2/3 of primary brain tumor diagnoses are GBM, of which 95% are primary lesions. In this study, we aimed to evaluate whether more sunlight exposure has an effect on survival of patients with primary GBM. A total of 111 patients with primary GBM were enrolled from Kayseri in inner Anatolia which has a cold climate (n: 40) and Mersin in Mediterranean region with a warm climate and more sunlight exposure (n: 71). The patients with primary GBM were divided into two groups as Kayseri and Mersin and compared for progression free survival (PFS) and overall survival (OS). The PFS values were 7.0 and 4.7 months for Kayseri and Mersin groups, respectively (p=0.10) and the respective OS values were 13.3 and 9.4 months (p=0.13). We did not found any significant difference regarding age, sex, comorbidity, smoking, surgery, resurgery, adjuvant chemoradiotherapy and palliative chemotherapy between the groups. We found that more sunlight exposure had no impact on prognosis of patients with primary GBM, adding inconsistency to the literature about the relationship between sunlight and GBM.

  2. Sunlight exposure, antioxidants, and age-related macular degeneration.

    Science.gov (United States)

    Fletcher, Astrid E; Bentham, Graham C; Agnew, Maureen; Young, Ian S; Augood, Cristina; Chakravarthy, Usha; de Jong, Paulus T V M; Rahu, Mati; Seland, Johan; Soubrane, Gisele; Tomazzoli, Laura; Topouzis, Fotis; Vingerling, Johannes R; Vioque, Jesus

    2008-10-01

    To examine the association of sunlight exposure and antioxidant level with age-related macular degeneration (AMD). Four thousand seven hundred fifty-three participants aged 65 years or older in the European Eye Study underwent fundus photography, were interviewed for adult lifetime sunlight exposure, and gave blood for antioxidant analysis. Blue light exposure was estimated by combining meteorologic and questionnaire data. Data on sunlight exposure and antioxidants were available in 101 individuals with neovascular AMD, 2182 with early AMD, and 2117 controls. No association was found between blue light exposure and neovascular or early AMD. Significant associations were found between blue light exposure and neovascular AMD in individuals in the quartile of lowest antioxidant level-vitamin C, zeaxanthin, vitamin E, and dietary zinc-with an odds ratio of about 1.4 for 1 standard deviation unit increase in blue light exposure. Higher odds ratios for blue light were observed with combined low antioxidant levels, especially vitamin C, zeaxanthin, and vitamin E (odds ratio, 3.7; 95% confidence interval, 1.6-8.9), which were also associated with early stages of AMD. Although it is not possible to establish causality between sunlight exposure and neovascular AMD, our results suggest that people in the general population should use ocular protection and follow dietary recommendations for the key antioxidant nutrients.

  3. [Most common skin disorders caused by excessive exposure to sunlight].

    Science.gov (United States)

    Zitás, Éva; Mészáros, Judit

    2016-01-17

    The healing properties of sunlight has been known for millennia, however the gradual deterioration of the ozone layer and the increased use of sun tanning beds in recent decades are causing an increase in skin damaging ultraviolet exposure. In this article the most common photodermatoses and the principles of their treatments are reviewed.

  4. Photochemical transformation of graphene oxide in sunlight (journal)

    Science.gov (United States)

    Graphene oxide (GO) is a graphene derivative that is more easily manufactured in large scale and used to synthesize reduced graphene oxide (rGO) with properties analogous to graphene. In this study, we investigate the photochemical fate of GO under sunlight conditions. The resu...

  5. Electricity from Sunlight: The Future of Photovoltaics. Worldwatch Paper 52.

    Science.gov (United States)

    Flavin, Christopher

    Solar photovoltaic cells have been called the ultimate energy technology, environmentally benign and without moving parts, solar cells directly convert sunlight into electricity. Photovoltaic energy conversion is fundamentally different from all other forms of electricity generation. Without turbines, generators or other mechanical equipment, it…

  6. 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.

  7. Randomized Control Trial Assessing Impact of Increased Sunlight Exposure versus Vitamin D Supplementation on Lipid Profile in Indian Vitamin D Deficient Men.

    Science.gov (United States)

    Patwardhan, Vivek G; Mughal, Zulf M; Padidela, Raja; Chiplonkar, Shashi A; Khadilkar, Vaman V; Khadilkar, Anuradha V

    2017-01-01

    Despite abundance of sunshine in India, Vitamin D deficiency is common and therefore there is an increasing trend toward taking Vitamin D supplements either as prescription medicine or as a nutritional supplement. Studies have suggested that duration of sun exposure may influence serum lipid profile. To study the effect of increased sunlight exposure versus Vitamin D supplementation on Vitamin D status and lipid profile in individuals with Vitamin D deficiency (25-hydroxyvitamin-D [25OHD] 50 nmol/L, n = 50) and intervention (sunlight exposure group" (n = 50, received at least 20 min sunlight exposure to forearms and face between 11 a.m. and 3 p.m. over and above their current exposure) or "cholecalciferol supplement group" (n = 50, received oral cholecalciferol 1000 IU/day). Significant increase in 25OHD concentrations was seen in both intervention groups (P sunlight exposure (P sunlight exposure significantly reduced TC, LDL-C, and HDL-C concentrations, and cholecalciferol supplementation increased TC and HDL-C concentrations.

  8. Response of Sea Surface Temperature to Chlorophyll-a Concentration in the Tropical Pacific: Annual Mean,Seasonal Cycle, and Interannual Variability

    Institute of Scientific and Technical Information of China (English)

    LIN Pengfei; LIU Hailong; YU Yongqiang; ZHANG Xuehong

    2011-01-01

    The response of the upper-ocean temperatures and currents in the tropical Pacific to the spatial distribution of chlorophyll-a and its seasonal cycle is investigated using a coupled atmosphere-ocean model and a stand-alone oceanic general circulation model. The spatial distribution of chlorophyll-a significantly influences the mean state of models in the tropical Pacific. The annual mean SST in the eastern equatorial Pacific decreases accompanied by a shallow thermocline and stronger currents because of shallow penetration depth of solar radiation. Equatorial upwelling dominates the heat budget in that region. Atmosphere-ocean interaction processes can further amplify such changes.The seasonal cycle of chlorophyll-a can dramatically change ENSO period in the coupled model. After introducing the seasonal cycle of chlorophyll-a concentration, the peak of the power spectrum becomes broad, and longer periods (>3 years) are found. These changes led to ENSO irregularities in the model.The increasing period is mainly due to the slow speed of Rossby waves, which are caused by the shallow mean thermocline in the northeastern Pacific.

  9. Response of Sea Surface Temperature to Chlorophyll-a Concentration in the Tropical Pacific:Annual Mean,Seasonal Cycle,and Interannual Variability

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    The response of the upper-ocean temperatures and currents in the tropical Pacific to the spatial distribution of chlorophyll-a and its seasonal cycle is investigated using a coupled atmosphere-ocean model and a stand-alone oceanic general circulation model.The spatial distribution of chlorophyll-a significantly influences the mean state of models in the tropical Pacific.The annual mean SST in the eastern equatorial Pacific decreases accompanied by a shallow thermocline and stronger currents because of shallow penetration depth of solar radiation.Equatorial upwelling dominates the heat budget in that region.Atmosphere-ocean interaction processes can further amplify such changes. The seasonal cycle of chlorophyll-a can dramatically change ENSO period in the coupled model.After introducing the seasonal cycle of chlorophyll-a concentration,the peak of the power spectrum becomes broad,and longer periods(〉3 years) are found.These changes led to ENSO irregularities in the model. The increasing period is mainly due to the slow speed of Rossby waves,which are caused by the shallow mean thermocline in the northeastern Pacific.

  10. Vitamin D and Sunlight Exposure in Newly-Diagnosed Parkinson's Disease

    National Research Council Canada - National Science Library

    Wang, Juan; Yang, Deyu; Yu, Yu; Shao, Gaohai; Wang, Qunbo

    2016-01-01

    ...), while the effects of sunlight exposure have not yet been fully investigated. Therefore, we evaluated the associations between serum vitamin D, vitamin D intake, sunlight exposure, and newly-diagnosed PD patients in a Chinese population...

  11. Sunlight Exposure and Vitamin D Status in Breastfed Infants.

    Science.gov (United States)

    Meena, Pinky; Dabas, Aashima; Shah, Dheeraj; Malhotra, Rajeev Kumar; Madhu, S V; Gupta, Piyush

    2017-02-15

    To correlate the sunlight exposure in first 6 months to vitamin D status at 6 months of age in predominantly breastfed infants; and to quantify the sunlight exposure required to achieve serum 25(OH)D level >20 ng/mL, by 6 months of age. Design: Prospective cohort. Tertiary-care hospital predominantly catering to urban poor population in Delhi. 132 healthy infants, delivered at term, and predominantly breastfed were enrolled at 6-8 weeks of age. Of these, 100 infants were available for final evaluation at 6 months of age (mean (SD) follow-up: 126 (17) days). Baseline maternal vitamin D (serum 25(OH)D) levels were obtained at enrolment. The mothers were asked to maintain a daily record of duration of sunlight exposure, timing of exposure, and body surface area exposed, for the infant, on a pre-designed proforma, till the child was 6 months of age. Infant's serum 25(OH)D was measured at 6 months of age. Cumulative Sun Index was calculated as a composite measure of overall duration/time/body surface area exposed to sunlight; and correlated with the infant serum 25(OH)D after adjusting for baseline maternal serum 25(OH)D levels, season of exposure, and skin color of the infant. Sun index for exposure in morning (before 10 am) and afternoon (10 am-3 pm) were also correlated to vitamin D status. Of 100 mother-infant pairs completing the study, 90 mothers had vitamin D deficiency (serum 25(OH)D exposure of infants to sunlight was 17 min per week, on 6% of body surface area. Vitamin D levels of 67 (67%) infants at 6 months were less than 12 ng/mL and another 23% had insufficient levels (12-20 ng/mL). Cumulative sun index correlated positively to infant's serum 25(OH)D level at 6 months of age (r= 0.461, Psunlight exposure, between 10 am and 3 pm, over 40% body area (infant clothed in diapers, in prone position) for at least 16 weeks, was estimated requirement to achieve sufficient vitamin D levels (>20 ng/mL) by 6 months of age. There is a significant positive correlation

  12. Recovery of hexavalent chromium from water using photoactive TiO2-montmorillonite under sunlight

    Directory of Open Access Journals (Sweden)

    Ridha Djellabi

    2016-04-01

    Full Text Available Hexavalent chromium was removed from water under sunlight using a synthesized TiO2-montmorillonite (TiO2-M employing tartaric acid as a hole scavenger. Cr(VI species was then reduced to Cr(III species by electrons arising from TiO2 particles. After that, the produced Cr(III species  was transferred to montmorillonite  due to electrostatic attractions leading to  set free TiO2 particles for a further Cr(VI species reduction. Furthermore, produced Cr(III, after Cr(VI reduction, does not  penetrate into the solution. The results indicate that no dark adsorption of Cr(VI species on TiO2-M is present, however, the reduction of Cr(VI species under sunlight increased strongly as a function of tartaric acid concentration up to 60 ppm, for which the extent of reduction is maximum within 3 h. On the other hand, the reduction extent of Cr(VI species is maximum with an initial concentration of Cr(VI species lower than 30 ppm by the use of 0.2 g/L of TiO2-M. Nevertheless, the increase of the Cr(VI initial concentration led to increase the amount of Cr(VI species reduced (capacity of reduction until a Cr(VI concentration of 75 and 100 ppm, for which  it remained constant at around 221 mg/g. For comparison, the increase of Cr(VI species concentration in the case of the commercial TiO2 P25 under the same conditions exhibited its deactivation when the reduced amount decreased from 198.1 to 157.6 mg/g as the concentration increased from 75 to 100 ppm.

  13. Planar micro-optic solar concentrator

    National Research Council Canada - National Science Library

    Karp, Jason H; Tremblay, Eric J; Ford, Joseph E

    2010-01-01

    We present a new approach to solar concentration where sunlight collected by each lens in a two-dimensional lens array is coupled into a shared, planar waveguide using localized features placed at each lens focus...

  14. Exposure time to sunlight for ultra violet light therapy

    Directory of Open Access Journals (Sweden)

    Srinivas C

    1991-01-01

    Full Text Available Exposure time to sunlight for photo or photochemotherapy is arbitrarily determined. This could lead to inadequate or over exposure. As a sequence to our initial pilot study on exposure time for PUVASOL, we have now developed a bar chart which could be used as a guide to achieve a more logical and uniform exposure time during different months. We plan to extend the study to different zones in India.

  15. Sunlight Exposure and Breast Density: A Population-Based Study

    Science.gov (United States)

    Wu, Sheng-Hui; So, Edwin; Lam, Tsz-ping; Woo, Jean; Yuen, PY; Qin, Ling; Ku, Susanna

    2013-01-01

    Purpose This study aims to assess the association of sunlight exposure with breast cancer risk, measured by the breast density assessed from Tabár's mammographic pattern in Chinese women. Methods A total of 676 premenopausal women were recruited to participate in this study, in which 650 completed a validated sunlight exposure questionnaire via telephone. The mammograms were classified according to Tabár's classification for parenchyma, and patterns IV & V and I, II & III indicated respectively high and low risk mammographic patterns for breast cancer. The odds ratios (OR) and 95% confidence intervals (CIs) for sun exposure-related variables were estimated using unconditional logistic regression with adjustment for potential confounders. Results Among 646 participants, women with high breast cancer risk (Tabár's patterns IV &V) had less hours spent in the sun than those with low risk (I, II & III) at any age stage. A higher level of sunlight exposure was associated with a significantly lower risk having high risk Tabár's pattern. Women aged 40 to 44 years who were in the highest tertile of lifetime total hours spent in the sun had a multi-adjusted OR of 0.41 (95% CI, 0.18-0.92; p for trend=0.03) compared with those in the lowest tertile (>2.19 hr/day vs. sunlight exposure is related to a lower risk of having high risk breast density pattern in premenopausal women. Our results also suggest the most relevant period of exposure is during earlier life. PMID:23843849

  16. Effect of grape bunch sunlight exposure and UV radiation on phenolics and volatile composition of Vitis vinifera L. cv. Pinot noir wine.

    Science.gov (United States)

    Song, Jianqiang; Smart, Richard; Wang, Hua; Dambergs, Bob; Sparrow, Angela; Qian, Michael C

    2015-04-15

    The effect of canopy leaf removal and ultraviolet (UV) on Pinot noir grape and wine composition was investigated in this study. Limited basal leaf removal in the fruit zone was conducted, compared to shaded bunches. The UV exposure was controlled using polycarbonate screens to block UV radiation, and acrylic screens to pass the UV. The results showed that bunch sunlight and UV exposure significantly increased the Brix and pH in the grape juice, and increased substantially wine colour density, anthocyanins, total pigment, total phenolics and tannin content. Bunch sunlight and UV exposure affected terpene alcohols, C13-norisprenoids and other volatile composition of the wine differently. Sunlight exposure and UV resulted in increase of nerol, geraniol and citronellol but not linalool. Sunlight exposure slightly increased the concentration of β-ionone, but the increase was not statistically significant for UV treatment. Neither sunlight nor UV treatment showed any impact on the concentration of β-damascenone. Copyright © 2014 Elsevier Ltd. All rights reserved.

  17. Effects of sunlight exposure on grapevine powdery mildew development.

    Science.gov (United States)

    Austin, Craig N; Wilcox, Wayne F

    2012-09-01

    Natural and artificially induced shade increased grapevine powdery mildew (Erysiphe necator) severity in the vineyard, with foliar disease severity 49 to 75% higher relative to leaves in full sun, depending on the level of natural shading experienced and the individual experiment. Cluster disease severities increased by 20 to 40% relative to those on check vines when ultraviolet (UV) radiation was filtered from sunlight reaching vines in artificial shading experiments. Surface temperatures of leaves in full sunlight averaged 5 to 8°C higher than those in natural shade, and in one experiment, filtering 80% of all wavelengths of solar radiation, including longer wavelengths responsible for heating irradiated tissues, increased disease more than filtering UV alone. In controlled environment experiments, UV-B radiation reduced germination of E. necator conidia and inhibited both colony establishment (hyphal formation and elongation) and maturity (latent period). Inhibitory effects of UV-B radiation were significantly greater at 30°C than at 20 or 25°C. Thus, sunlight appears to inhibit powdery mildew development through at least two mechanisms, i.e., (i) UV radiation's damaging effects on exposed conidia and thalli of the pathogen; and (ii) elevating temperatures of irradiated tissues to a level supraoptimal or inhibitory for pathogen development. Furthermore, these effects are synergistic at temperatures near the upper threshold for disease development.

  18. Inter-annual trend of the primary contribution of ship emissions to PM2.5 concentrations in Venice (Italy): Efficiency of emissions mitigation strategies

    Science.gov (United States)

    Contini, Daniele; Gambaro, Andrea; Donateo, Antonio; Cescon, Paolo; Cesari, Daniela; Merico, Eva; Belosi, Franco; Citron, Marta

    2015-02-01

    Ships and harbour emissions are currently increasing, due to the increase of tourism and trade, with potential impact on global air pollution and climate. At local scale, in-port ship emissions influence air quality in coastal areas impacting on health of coastal communities. International legislations to reduce ship emissions, both at Worldwide and European levels, are mainly based on the use of low-sulphur content fuel. In this work an analysis of the inter-annual trends of primary contribution, ε, of tourist shipping to the atmospheric PM2.5 concentrations in the urban area of Venice has been performed. Measurements have been taken in the summer periods of 2007, 2009 and 2012. Results show a decrease of ε from 7% (±1%) in 2007 to 5% (±1%) in 2009 and to 3.5% (±1%) in 2012. The meteorological and micrometeorological conditions of the campaigns were similar. Tourist ship traffic during measurement campaigns increased, in terms of gross tonnage, of about 25.4% from 2007 to 2009 and of 17.6% from 2009 to 2012. The decrease of ε was associated to the effect of a voluntary agreement (Venice Blue Flag) for the use of low-sulphur content fuel enforced in the area between 2007 and 2009 and to the implementation of the 2005/33/CE Directive in 2010. Results show that the use of low-sulphur fuel could effectively reduce the impact of shipping to atmospheric primary particles at local scale. Further, voluntary agreement could also be effective in reducing the impact of shipping on local air quality in coastal areas.

  19. South African university student knowledge of eye protection against sunlight

    Directory of Open Access Journals (Sweden)

    O. A. Oduntan

    2009-12-01

    Full Text Available Exposure to sunlight has been associated with several ocular conditions such as cataract, age-related macular degeneration, and conjunctival neoplasm. Knowledge of protective modalities and good behavioural practice involving eye protection is essential to prevent adverse effects of sunlight. The purpose of this study was to establish knowledge amongst randomly selected university students in South Africa, of prevention modalities against the adverse effects of sunlight. A questionnaire relating to the knowledge of preventive modalities was completed by randomly selected students from four universities selected by convenience sampling.  Questionnaires completed by one thousand, eighthundred and thirty two (N =1832 subjects were analysed with descriptive statistics using Stata version 10.  The participants’ ages ranged from 17 to 55 years (mean = 21.03 ± 3.4 years.  They included 43.7% males and 56.3% females.  They were 68.3% Blacks, 20.0% Whites, 3.4% Indians and 7.4% Coloureds. Many (82.3% of them knew that excessive exposure to sunlight can adversely affect the eyes. Only 28.5% reported that they often wore sunglasses outdoors. Only 38.5% of the participants knew that not all spectacles or contact lenses could protect eyes from ultraviolet radiation. However, many, 87.7% and 69.5% respectively knew that sunglasses and spectacles could be specifically designed to block UVR from entering the eye. Just over half (52.7% knew that contact lenses can be specifically designed to block the UVR. Many, (68.4% agreed that wearing hats with brims could protect the eyes against harmful radiation from the sun and the majority, 95.8% agreed that there was a need for awareness campaigns about the effects of the sun on the eye and against excessive exposure. Female respondents had more knowledge of preventive modalities than the males.  Knowledge of preventive modalities among the respondents varied significantly with the type of questions and was

  20. Concentrations and Correlation of Eight Important Elements in the Annual Rings of Pinus massoniana in Dinghushan,Guangdong%广东鼎湖山马尾松年轮元素含量及其相关性研究

    Institute of Scientific and Technical Information of China (English)

    侯爱敏; 彭少麟; 周国逸

    2002-01-01

    The concentrations of the elements in the annual rings of Pinus massoniana reflect the influence of both regional factors and species characteristics in absorbing,accumulating and distributing elements.The changes of environmental factors may result in concentration changes of elements in tree rings.Therefore,variations of tree ring element concentration may provide some clue in studying environmental changes.Some of eight elements studied are strongly correlated with others,the reason of which might be their similar structural and enzymatic functions in the plant cell,similar chemical properties and similar or opposite reaction to variations in some environment factors.

  1. Dose-Response Effect of Sunlight on Vitamin D2 Production in Agaricus bisporus Mushrooms

    DEFF Research Database (Denmark)

    Urbain, Paul; Jakobsen, Jette

    2015-01-01

    The dose response effect of UV-B irradiation from sunlight on vitamin D2 content of sliced Agaricus bisporus (white button mushroom) during the process of sun-drying was investigated.Real-time UV-B and UV-A data were obtained using a high-performance spectroradiometer. During the first hour...... of sunlight exposure, the vitamin D2 content of the mushrooms increased in a linear manner, with concentrations increasing from 0.1 μg/g up to 3.9 ± 0.8 μg/g dry weight (DW). At the subsequent two measurements one and 3 h later, respectively, a plateau was reached. Two hours of additional exposure triggered...... a significant decline in vitamin D2 content. After just 15 min of sun exposure and an UV-B dose of 0.13 J/cm(2), the vitamin D2 content increased significantly to 2.2 ± 0.5 μg/g DW (P vitamin D2 per 100 g of fresh mushrooms and comparable to levels found...

  2. Dose-Response Effect of Sunlight on Vitamin D2 Production in Agaricus bisporus Mushrooms.

    Science.gov (United States)

    Urbain, Paul; Jakobsen, Jette

    2015-09-23

    The dose response effect of UV-B irradiation from sunlight on vitamin D2 content of sliced Agaricus bisporus (white button mushroom) during the process of sun-drying was investigated.Real-time UV-B and UV-A data were obtained using a high-performance spectroradiometer. During the first hour of sunlight exposure, the vitamin D2 content of the mushrooms increased in a linear manner, with concentrations increasing from 0.1 μg/g up to 3.9 ± 0.8 μg/g dry weight (DW). At the subsequent two measurements one and 3 h later, respectively, a plateau was reached. Two hours of additional exposure triggered a significant decline in vitamin D2 content. After just 15 min of sun exposure and an UV-B dose of 0.13 J/cm(2), the vitamin D2 content increased significantly to 2.2 ± 0.5 μg/g DW (P < 0.0001), which is equivalent to 17.6 μg (704 IU) vitamin D2 per 100 g of fresh mushrooms and comparable to levels found in fatty fish like the Atlantic salmon.

  3. Natural organic matter and sunlight accelerate the degradation of 17ss-estradiol in water

    Energy Technology Data Exchange (ETDEWEB)

    Leech, Dina M. [Institute of Marine Sciences, University of North Carolina at Chapel Hill, 3431 Arendell Street, Morehead City, NC 28557 (United States)], E-mail: dmleech@email.unc.edu; Snyder, Matthew T.; Wetzel, Robert G. [Department of Environmental Sciences and Engineering, School of Public Health, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599 (United States)

    2009-03-01

    Nanomolar concentrations of steroid hormones such as 17{beta}-estradiol can influence the reproductive development and sex ratios of invertebrate and vertebrate populations. Thus their release into surface and ground waters from wastewater facilities and agricultural applications of animal waste is of environmental concern. Many of these compounds are chromophoric and susceptible to photolytic degradation. High intensity UV-C radiation has been demonstrated to degrade some of these compounds in engineered systems. However, the degradation efficacy of natural solar radiation in shallow fresh waters is less understood. Here photolytic experiments with 17{beta}-estradiol demonstrated modest photodegradation ({approx} 26%) when exposed to simulated sunlight between 290 and 720 nm. Photodegradation significantly increased ({approx} 40-50%) in the presence of 2.0-15.0 mg/l of dissolved organic carbon (DOC) derived from humic acids of the Suwannee River, GA. However, rates of photodegradation reached a threshold at approximately 5.0 mg/l DOC. Observed suppression of photolysis in the presence of a radical inhibitor (i.e. 2-propanol) indicated that a significant proportion of the degradation was due to radicals formed from the photolysis of DOC. Although photodegradation was greatest in full sunlight containing UV-B (290-320 nm), degradation was also detected with UV-A (320-400 nm) and visible light (400-720 nm) alone.

  4. Suspended-sediment concentrations, bedload, particle sizes, surrogate measurements, and annual sediment loads for selected sites in the lower Minnesota River Basin, water years 2011 through 2016

    Science.gov (United States)

    Groten, Joel T.; Ellison, Christopher A.; Hendrickson, Jon S.

    2016-12-20

    Accurate measurements of fluvial sediment are important for assessing stream ecological health, calculating flood levels, computing sediment budgets, and managing and protecting water resources. Sediment-enriched rivers in Minnesota are a concern among Federal, State, and local governments because turbidity and sediment-laden waters are the leading impairments and affect more than 6,000 miles of rivers in Minnesota. The suspended sediment in the lower Minnesota River is deleterious, contributing about 75 to 90 percent of the suspended sediment being deposited into Lake Pepin. The Saint Paul District of the U.S. Army Corps of Engineers and the Lower Minnesota River Watershed District collaborate to maintain a navigation channel on the lower 14.7 miles of the Minnesota River through scheduled dredging operations. The Minnesota Pollution Control Agency has adopted a sediment-reduction strategy to reduce sediment in the Minnesota River by 90 percent by 2040.The U.S. Geological Survey, in cooperation with the U.S. Army Corps of Engineers, the Minnesota Pollution Control Agency, and the Lower Minnesota River Watershed District, collected suspended-sediment, bedload, and particle-size samples at five sites in the lower Minnesota River Basin during water years 2011 through 2014 and surrogate measurements of acoustic backscatter at one of these sites on the lower Minnesota River during water years 2012 through 2016 to quantify sediment loads and improve understanding of sediment-transport relations. Annual sediment loads were computed for calendar years 2011 through 2014.Data collected from water years 2011 through 2014 indicated that two tributaries, Le Sueur River and High Island Creek, had the highest sediment yield and concentrations of suspended sediment. These tributaries also had greater stream gradients than the sites on the Minnesota River. Suspended fines were greater than suspended sand at all sites in the study area. The range of median particle sizes matched

  5. Sunlight and Skin Cancer: Lessons from the Immune System

    OpenAIRE

    Ullrich, Stephen E

    2007-01-01

    The ultraviolet (UV) radiation in sunlight induces skin cancer development. Skin cancer is the most common form of human neoplasia. Estimates suggest that in excess of 1.5 million new cases of skin cancer (www.cancer.org/statistics) will be diagnosed in the United States this year Fortunately, because of their highly visible location, skin cancers are more rapidly diagnosed and more easily treated than other types of cancer. Be that as it may, approximately 10,000 Americans a year die from sk...

  6. Sunlight and Skin Cancer: Lessons from the Immune System

    OpenAIRE

    Ullrich, Stephen E

    2007-01-01

    The ultraviolet (UV) radiation in sunlight induces skin cancer development. Skin cancer is the most common form of human neoplasia. Estimates suggest that in excess of 1.5 million new cases of skin cancer (www.cancer.org/statistics) will be diagnosed in the United States this year Fortunately, because of their highly visible location, skin cancers are more rapidly diagnosed and more easily treated than other types of cancer. Be that as it may, approximately 10,000 Americans a year die from sk...

  7. Effect of Sunlight Exposure on Bone Mineral Density in Children with Severe Disability.

    Science.gov (United States)

    Kanemura, Hideaki; Hatakeyama, Kazuo; Sano, Fumikazu; Yagasaki, Hideaki; Sugita, Kanji; Aihara, Masao

    2016-08-01

    The aim of this study was to determine the efficacy of sunlight exposure for increasing bone mineral density (BMD) in children with severe disability. The subjects were five children with severe disability, aged 6 to 8 years. BMD was measured at baseline and after 3, 6, 9, and 12 months of starting sunlight exposure. All caregivers of patients were instructed to create opportunities to stay outdoors. Daily sunlight exposure time was defined as hours of staying outdoors. Mean hours of sunbathing per day were calculated at baseline and after 3, 6, 9, and 12 months of starting sunlight exposure. Sunlight exposure tended to be longer after starting than before starting in all patients, but the difference was not significant (p = 0.052). Along with the increase in sunlight exposure, BMD increased significantly after the start of sunlight exposure in all patients (p sunlight exposure. No patients had bone fractures after the start of sunlight exposure. These results suggest that sunlight exposure increased BMD, and that this may reduce the risk of bone fracture in children with disability. Georg Thieme Verlag KG Stuttgart · New York.

  8. Use of sunlight to degrade oxytetracycline in marine aquaculture's waters.

    Science.gov (United States)

    Leal, J F; Esteves, V I; Santos, E B H

    2016-06-01

    Oxytracycline (OTC) is a broad spectrum antibiotic authorized for use in European aquaculture. Its photo-degradation has been widely studied in synthetic aqueous solutions, sometimes resorting to expensive methods and without proven effectiveness in natural waters. Thus, this work studied the possibility to apply the solar photo-degradation for removal of OTC from marine aquaculture's waters. For that, water samples were collected at different locals of the water treatment circuit, from two different aquaculture companies. Water samples were firstly characterized regarding to pH, salinity, total suspended solids (TSS), organic carbon and UV-Vis spectroscopic characteristics. Then, the samples were spiked with OTC and irradiated using simulated sunlight in order to evaluate the matrix effects on OTC photo-degradation. From kinetic results, the apparent quantum yields and the outdoor half-life times, at 40°N for midsummer and midwinter days were estimated by the first time for these conditions. For a midsummer day, at sea level, the outdoor half-life time predicted for OTC in these aquaculture's waters ranged between 21 and 25 min. Additionally, the pH and salinity effects on the OTC photo-degradation were evaluated and it has been shown that high pH values and the presence of sea salt increase the OTC photo-degradation rate in aquaculture's waters, compared to results in deionised water. The results are very promising to apply this low-cost methodology using the natural sunlight in aquaculture's waters to remove OTC.

  9. Decomposition of S-Nitrosothiols Induced by UV and Sunlight

    Directory of Open Access Journals (Sweden)

    Manoj M. Veleeparampil

    2009-01-01

    Full Text Available Photochemical release of nitric oxide (NO from the S-nitroso derivatives of glutathione, L-cysteine, N-acetyl-L-cysteine, L-cysteinemethylester, D,L-penicillamine, N-acetyl-D,L-penicillamine, and N-acetylcysteamine has been investigated at neutral and acidic pH. The release of NO from RSNO is one of the key reactions that could be utilized in photodynamic therapy. The UV-VIS and HPLC analyses have shown that under argon saturated conditions, disulfide (RSSR is the major product of UV as well as sunlight induced decomposition. While in aerated conditions, nitirite—the end product of the oxidation of NO—was also observed along with disulfide. The formation of thiyl radical as the intermediate was reconfirmed by laser flash photolysis. The initial rate of formation of NO was on the order of 10−10dm3mol−1s−1. The quantum yields of these reactions were in the range of 0.2–0.8. The high quantum yields observed in the photo induced release of NO from RSNO using both UV and sunlight demonstrate the potential application of these reactions in photodynamic therapy.

  10. Can Skin Exposure to Sunlight Prevent Liver Inflammation?

    Directory of Open Access Journals (Sweden)

    Shelley Gorman

    2015-05-01

    Full Text Available Liver inflammation contributes towards the pathology of non-alcoholic fatty liver disease (NAFLD. Here we discuss how skin exposure to sunlight may suppress liver inflammation and the severity of NAFLD. Following exposure to sunlight-derived ultraviolet radiation (UVR, the skin releases anti-inflammatory mediators such as vitamin D and nitric oxide. Animal modeling studies suggest that exposure to UVR can prevent the development of NAFLD. Association studies also support a negative link between circulating 25-hydroxyvitamin D and NAFLD incidence or severity. Clinical trials are in their infancy and are yet to demonstrate a clear beneficial effect of vitamin D supplementation. There are a number of potentially interdependent mechanisms whereby vitamin D could dampen liver inflammation, by inhibiting hepatocyte apoptosis and liver fibrosis, modulating the gut microbiome and through altered production and transport of bile acids. While there has been a focus on vitamin D, other mediators induced by sun exposure, such as nitric oxide may also play important roles in curtailing liver inflammation.

  11. Can skin exposure to sunlight prevent liver inflammation?

    Science.gov (United States)

    Gorman, Shelley; Black, Lucinda J; Feelisch, Martin; Hart, Prue H; Weller, Richard

    2015-05-05

    Liver inflammation contributes towards the pathology of non-alcoholic fatty liver disease (NAFLD). Here we discuss how skin exposure to sunlight may suppress liver inflammation and the severity of NAFLD. Following exposure to sunlight-derived ultraviolet radiation (UVR), the skin releases anti-inflammatory mediators such as vitamin D and nitric oxide. Animal modeling studies suggest that exposure to UVR can prevent the development of NAFLD. Association studies also support a negative link between circulating 25-hydroxyvitamin D and NAFLD incidence or severity. Clinical trials are in their infancy and are yet to demonstrate a clear beneficial effect of vitamin D supplementation. There are a number of potentially interdependent mechanisms whereby vitamin D could dampen liver inflammation, by inhibiting hepatocyte apoptosis and liver fibrosis, modulating the gut microbiome and through altered production and transport of bile acids. While there has been a focus on vitamin D, other mediators induced by sun exposure, such as nitric oxide may also play important roles in curtailing liver inflammation.

  12. The impact of sunlight on high-latitude equivalent currents

    CERN Document Server

    Laundal, K M; Østgaard, N; Reistad, J P; Haaland, S; Snekvik, K; Tenfjord, P; Ohtani, S; Milan, S E

    2016-01-01

    Ground magnetic field measurements can be mathematically related to an overhead ionospheric equivalent current. In this study we look in detail at how the global equivalent current, calculated using more than 30 years of SuperMAG magnetometer data, changes with sunlight conditions. The calculations are done using spherical harmonic analysis in quasi-dipole coordinates, a technique which leads to improved accuracy compared to previous studies. Sorting the data according to the location of the sunlight terminator and orientation of the interplanetary magnetic field (IMF), we find that the equivalent current resembles ionospheric convection patterns on the sunlit side of the terminator but not on the dark side. On the dark side, with southward IMF, the current is strongly dominated by a dawn cell and the current across the polar cap has a strong dawnward component. The contrast between the sunlit and dark side increases with increasing values of the $\\mathit{F}_{10.7}$ index, showing that increasing solar EUV fl...

  13. Seasonal and inter-annual photosynthetic response of representative C4 species to soil water content and leaf nitrogen concentration across a tropical seasonal floodplain

    NARCIS (Netherlands)

    Mantlana, K.B.; Arneth, A.; Veenendaal, E.M.; Wohland, P.; Wolski, P.; Kolle, O.; Lloyd, J.

    2008-01-01

    We examined the seasonal and inter-annual variation of leaf-level photosynthetic characteristics of three C4 perennial species, Cyperus articulatus, Panicum repens and Imperata cylindrica, and their response to environmental variables, to determine comparative physiological responses of plants repre

  14. Sunlight inactivation of viruses in open-water unit process treatment wetlands: modeling endogenous and exogenous inactivation rates.

    Science.gov (United States)

    Silverman, Andrea I; Nguyen, Mi T; Schilling, Iris E; Wenk, Jannis; Nelson, Kara L

    2015-03-03

    Sunlight inactivation is an important mode of disinfection for viruses in surface waters. In constructed wetlands, for example, open-water cells can be used to promote sunlight disinfection and remove pathogenic viruses from wastewater. To aid in the design of these systems, we developed predictive models of virus attenuation that account for endogenous and exogenous sunlight-mediated inactivation mechanisms. Inactivation rate models were developed for two viruses, MS2 and poliovirus type 3; laboratory- and field-scale experiments were conducted to evaluate the models' ability to estimate inactivation rates in a pilot-scale, open-water, unit-process wetland cell. Endogenous inactivation rates were modeled using either photoaction spectra or total, incident UVB irradiance. Exogenous inactivation rates were modeled on the basis of virus susceptibilities to singlet oxygen. Results from both laboratory- and field-scale experiments showed good agreement between measured and modeled inactivation rates. The modeling approach presented here can be applied to any sunlit surface water and utilizes easily measured inputs such as depth, solar irradiance, water matrix absorbance, singlet oxygen concentration, and the virus-specific apparent second-order rate constant with singlet oxygen (k2). Interestingly, the MS2 k2 in the open-water wetland was found to be significantly larger than k2 observed in other waters in previous studies. Examples of how the model can be used to design and optimize natural treatment systems for virus inactivation are provided.

  15. Development of an algorithm to predict serum vitamin D levels using a simple questionnaire based on sunlight exposure.

    Science.gov (United States)

    Vignali, Edda; Macchia, Enrico; Cetani, Filomena; Reggiardo, Giorgio; Cianferotti, Luisella; Saponaro, Federica; Marcocci, Claudio

    2017-01-01

    Sun exposure is the main determinant of vitamin D production. The aim of this study was to develop an algorithm to assess individual vitamin D status, independently of serum 25(OHD) measurement, using a simple questionnaire, mostly relying upon sunlight exposure, which might help select subjects requiring serum 25(OHD) measurement. Six hundred and twenty adult subjects living in a mountain village in Southern Italy, located at 954 m above the sea level and at a latitude of 40°50'11″76N, were asked to fill the questionnaire in two different periods of the year: August 2010 and March 2011. Seven predictors were considered: month of investigation, age, sex, BMI, average daily sunlight exposure, beach holidays in the past 12 months, and frequency of going outdoors. The statistical model assumes four classes of serum 25(OHD) concentrations: ≤10, 10-19.9, 20-29.9, and ≥30 ng/ml. The algorithm was developed using a two-step procedure. In Step 1, the linear regression equation was defined in 385 randomly selected subjects. In Step 2, the predictive ability of the regression model was tested in the remaining 235 subjects. Seasonality, daily sunlight exposure and beach holidays in the past 12 months accounted for 27.9, 13.5, and 6.4 % of the explained variance in predicting vitamin D status, respectively. The algorithm performed extremely well: 212 of 235 (90.2 %) subjects were assigned to the correct vitamin D status. In conclusion, our pilot study demonstrates that an algorithm to estimate the vitamin D status can be developed using a simple questionnaire based on sunlight exposure.

  16. A novel solar cell fabricated with spiral photo-electrode for capturing sunlight 3-dimensionally

    Institute of Scientific and Technical Information of China (English)

    LIU Yong; SHEN Hui; DENG Youjun

    2006-01-01

    A novel solar cell fabricated with spiral photo-electrode for capturing sunlight 3-dimensionally (3D-cell) is proposed in this paper. We studied its performance both in solar simulator and in nature sunlight. Spiral photo-electrode of 3D-cell can receive sunlight from all directions and therefore can track the sun passively. And it is much insensitive to solar azimuth angle and shade. In addition, it increases the area to obtain scattered sunlight and reflected light. Compared with the dye-sensitized solar cells using sandwich structure, it would be more advantageous in the sealing technique.

  17. Asteroid thermal modeling in the presence of reflected sunlight

    Science.gov (United States)

    Myhrvold, Nathan

    2016-10-01

    This study addresses thermal modeling of asteroids with a new derivation of the Near Earth Asteroid Thermal (NEATM) model which correctly accounts for the presence of reflected sunlight in short wave IR bands. Kirchhoff's law of thermal radiation applies to this case and has important implications. New insight is provided into the ???? parameter in the NEATM model and it is extended to thermal models besides NEATM. The role of surface material properties on ???? is examined using laboratory spectra of meteorites and other asteroid compositional proxies; the common assumption that emissivity ????=0.9 in asteroid thermal models may not be justified and can lead to misestimating physical parameters. In addition, indeterminacy in thermal modeling can limit its ability to uniquely determine temperature and other physical properties. A new curve-fitting approach allows thermal modeling to be done independently of visible-band observational parameters, such as the absolute magnitude ????.

  18. Spectral analysis of red scattered sunlight at sunrise

    CERN Document Server

    Zagury, F; Zagury, Frederic; Fujii, Mitsugu

    2003-01-01

    We analyze and fit visible spectra of a red horizon at sunrise. The shape of the spectra consist of a blue continuum followed by a red bump. The reddest spectra are well fitted by the product of a spectrum of extinguished sunlight (Rayleigh extinction + ozone absorption) and 1/lambda^4. The former is essentially the radiation field in the outer atmosphere, at the scattering volume location; the latter corresponds to Rayleigh scattering by the gas. Moving to higher altitudes, a second component, corresponding to the spectrum of a blue sky, must be added. The spectra we have obtained are similar to spectra of red nebulae, suggesting there may be other explanations than an emission process to the red color of some nebulae.

  19. Sustainable sunlight to biogas is via marginal organics.

    Science.gov (United States)

    Shilton, Andy; Guieysse, Benoit

    2010-06-01

    Although biogas production from algae offers higher sunlight to biomass energy conversion efficiencies its production costs simply cannot compete with terrestrial plants. Unfortunately terrestrial plant cropping for biogas production is, in its own right, neither particularly sustainable nor profitable and its ongoing application is only driven by energy security concerns resulting in taxpayer subsidies. By comparison, scavenging the organic energy residual/wastes from food production offers a far more profitable and sustainable proposition and has an energy potential that dwarfs anything biogas production from dedicated energy crops can realistically offer. Thus researchers wanting to assist the development of sustainable biogas systems with viable process economics should forget about terrestrial and algal energy cropping and focus on the realm of scavengers.

  20. Circadian clocks optimally adapt to sunlight for reliable synchronization

    CERN Document Server

    Hasegawa, Yoshihiko

    2014-01-01

    Circadian oscillation provides selection advantages through synchronization to the daylight cycle. However, a reliable clock must be designed through two conflicting properties: entrainability to properly respond to external stimuli such as sunlight, and regularity to oscillate with a precise period. These two aspects do not easily coexist because better entrainability favors higher sensitivity, which may sacrifice the regularity. To investigate conditions for satisfying the two properties, we analytically calculated the optimal phase-response curve with a variational method. Our result indicates an existence of a dead zone, i.e., a time during which external stimuli neither advance nor delay the clock. This result is independent of model details and a dead zone appears only when the input stimuli obey the time course of actual insolation. Our calculation demonstrates that every circadian clock with a dead zone is optimally adapted to the daylight cycle. Our result also explains the lack of a dead zone in osc...

  1. Degradation of triclosan in the presence of p-aminobenzoic acid under simulated sunlight irradiation.

    Science.gov (United States)

    Zhai, Pingping; Chen, Xuan; Dong, Wenbo; Li, Hongjing; Chovelon, Jean-Marc

    2017-01-01

    This study aimed to investigate the degradation of triclosan (TCS) in the presence of p-aminobenzoic acid (PABA) under simulated sunlight irradiation (λ ≥ 290 nm). The effect of PABA concentration, pH, dissolved organic matter (DOM), and DOM-hydrolytic Fe(III) species complexes on the photodegradation of TCS in the presence of PABA (TCS-PABA) was also studied. The photolysis of TCS-PABA obeyed pseudo-first-order kinetics well, and the degradation of TCS-PABA enhanced with increasing solution pH (from 3.0 to 11.0). The presence of PABA inhibited the degradation of TCS-PABA, and the weakest inhibitory effect was observed while the concentration of PABA was 5 mg L(-1). The addition of DOM (Suwannee River fulvic acid standard I [SRFA], Suwannee River HA standard II [SRHA], and Suwannee River natural organic matter [SRNOM]) showed different inhibition effects on TCS-PABA degradation. However, higher Fe(III) concentration at the DOM concentration of 5 mg L(-1) could favor the formation of DOM-hydrolytic Fe(III) species complexes, further accelerating the degradation of TCS-PABA. In comparison with deionized water (DI water), TCS-PABA could be better photodegraded in river water nearby the effluent of a wastewater treatment plant. This study provides useful information for understanding the natural behavior of TCS in the presence of other organic contaminants.

  2. Persistence of Bacteroides ovatus under simulated sunlight irradiation

    KAUST Repository

    Dong, Shengkun

    2014-07-04

    Background: Bacteroides ovatus, a member of the genus Bacteroides, is considered for use in molecular-based methods as a general fecal indicator. However, knowledge on its fate and persistence after a fecal contamination event remains limited. In this study, the persistence of B. ovatus was evaluated under simulated sunlight exposure and in conditions similar to freshwater and seawater. By combining propidium monoazide (PMA) treatment and quantitative polymerase chain reaction (qPCR) detection, the decay rates of B. ovatus were determined in the presence and absence of exogenous photosensitizers and in salinity up to 39.5 parts per thousand at 27°C. Results: UVB was found to be important for B. ovatus decay, averaging a 4 log10 of decay over 6 h of exposure without the presence of extracellular photosensitizers. The addition of NaNO2, an exogenous sensitizer producing hydroxyl radicals, did not significantly change the decay rate of B. ovatus in both low and high salinity water, while the exogenous sensitizer algae organic matter (AOM) slowed down the decay of B. ovatus in low salinity water. At seawater salinity, the decay rate of B. ovatus was slower than that in low salinity water, except when both NaNO2 and AOM were present. Conclusion: The results of laboratory experiments suggest that if B. ovatus is released into either freshwater or seawater environment in the evening, 50% of it may be intact by the next morning; if it is released at noon, only 50% may be intact after a mere 5 min of full spectrum irradiation on a clear day. This study provides a mechanistic understanding to some of the important environmental relevant factors that influenced the inactivation kinetics of B. ovatus in the presence of sunlight irradiation, and would facilitate the use of B. ovatus to indicate the occurrence of fecal contamination.

  3. Sunlight Exposure, Pigmentation, and Incident Age-Related Macular Degeneration

    Science.gov (United States)

    Klein, Barbara E. K.; Howard, Kerri P.; Iyengar, Sudha K.; Sivakumaran, Theru A.; Meyers, Kristin J.; Cruickshanks, Karen J.; Klein, Ronald

    2014-01-01

    Purpose. Examine potential effects of sunlight exposure, hair color, eye color, and selected gene single-nucleotide polymorphisms (SNPs) on incidence of AMD. Methods. Subjects participated in up to five examinations over a 20-year period. Eye color, self-reported hair color as a teenager, and sunlight exposure were ascertained at the baseline examination. Presence and severity of AMD and its lesions were determined via fundus photographs. Genetic data were available on a subset of participants. The SNPs CFH Y402H rs1061170 and ARMS2 A69S rs10490924 were used to analyze genetic risk of AMD; OCA2 rs4778241 and HERC2 rs12913832 represented genetic determinants of eye color. Results. Incidence of early AMD was higher in blond/red-haired persons compared with brown/black-haired persons (hazard ratio [HR] 1.25, P = 0.02) and in persons with high sun exposure in their thirties (HR 1.41, P = 0.02). However, neither was significant after adjustment for multiple comparisons. Eye (HR 1.36, P = 0.006) and hair color (HR 1.42, P = 0.003) were associated with incidence of any retinal pigmentary abnormalities (RPAs). Both remained significant after adjustment for multiple comparisons. Neither presence of alleles for light-colored eyes nor those associated with high risk of late AMD altered the association of eye or hair color with early AMD. None of the characteristics studied were significantly associated with late AMD. Conclusions. Modest associations of eye color, hair color, and HERC2 genotype with any RPAs were found. Genes for AMD did not affect these associations. Eye color phenotype was more strongly associated with outcomes than HERC2 or OCA2 genotype. PMID:25125603

  4. Sunlight exposure, pigmentation, and incident age-related macular degeneration.

    Science.gov (United States)

    Klein, Barbara E K; Howard, Kerri P; Iyengar, Sudha K; Sivakumaran, Theru A; Meyers, Kristin J; Cruickshanks, Karen J; Klein, Ronald

    2014-08-14

    Examine potential effects of sunlight exposure, hair color, eye color, and selected gene single-nucleotide polymorphisms (SNPs) on incidence of AMD. Subjects participated in up to five examinations over a 20-year period. Eye color, self-reported hair color as a teenager, and sunlight exposure were ascertained at the baseline examination. Presence and severity of AMD and its lesions were determined via fundus photographs. Genetic data were available on a subset of participants. The SNPs CFH Y402H rs1061170 and ARMS2 A69S rs10490924 were used to analyze genetic risk of AMD; OCA2 rs4778241 and HERC2 rs12913832 represented genetic determinants of eye color. Incidence of early AMD was higher in blond/red-haired persons compared with brown/black-haired persons (hazard ratio [HR] 1.25, P = 0.02) and in persons with high sun exposure in their thirties (HR 1.41, P = 0.02). However, neither was significant after adjustment for multiple comparisons. Eye (HR 1.36, P = 0.006) and hair color (HR 1.42, P = 0.003) were associated with incidence of any retinal pigmentary abnormalities (RPAs). Both remained significant after adjustment for multiple comparisons. Neither presence of alleles for light-colored eyes nor those associated with high risk of late AMD altered the association of eye or hair color with early AMD. None of the characteristics studied were significantly associated with late AMD. Modest associations of eye color, hair color, and HERC2 genotype with any RPAs were found. Genes for AMD did not affect these associations. Eye color phenotype was more strongly associated with outcomes than HERC2 or OCA2 genotype. Copyright 2014 The Association for Research in Vision and Ophthalmology, Inc.

  5. Efficacy of a dose range of simulated sunlight exposures in raising vitamin D status in South Asian adults: implications for targeted guidance on sun exposure.

    Science.gov (United States)

    Farrar, Mark D; Webb, Ann R; Kift, Richard; Durkin, Marie T; Allan, Donald; Herbert, Annie; Berry, Jacqueline L; Rhodes, Lesley E

    2013-06-01

    Vitamin D is essential for bone health, and cutaneous synthesis is an important source. South Asians cannot attain adequate amounts of vitamin D by following general recommendations on summer sunlight exposure at northerly latitudes, and increased exposure may be appropriate for improving their vitamin D status. We examined the efficacy of a dose range of simulated summer sunlight exposures in raising vitamin D status in UK adults of South Asian ethnicity. In a dose-response study, healthy adults of South Asian ethnicity (n = 60; 20-60 y old) received 1 of 6 ultraviolet exposures ranging from 0.65 to 3.9 standard erythema doses (SEDs), which were equivalent to 15-90 min unshaded noontime summer sunlight at 53.5°N (Manchester, United Kingdom), 3 times/wk for 6 wk, while wearing casual clothes that revealed a 35% skin area. Serum 25-hydroxyvitamin D [25(OH)D] was measured weekly, and dietary vitamin D was estimated. At baseline, all completing participants (n = 51) were vitamin D insufficient [25(OH)D concentrations exposures ≥1.95 SEDs (equivalent to 45 min unshaded sunlight; n = 33) attained a mean (±SD) 25(OH)D concentration of 15.7 ± 5 ng/mL (mean rise: 8.7 ± 5.7 ng/mL; 95% CI: 6.8, 10.6 ng/mL; P 10 ng/mL. Targeted guidance on sunlight exposure could usefully enhance vitamin D status to avoid deficiency [25(OH)D concentration >10 ng/mL] in South Asians living at latitudes distant from the equator. This trial was registered at the ISRCTN Register (www.isrctn.org) as 07565297.

  6. Sunlight exposure and sun sensitivity associated with disability progression in multiple sclerosis

    NARCIS (Netherlands)

    D'hooghe, M. B.; Haentjens, P.; Nagels, G.; Garmyn, M.; De Keyser, J.

    2012-01-01

    Background: Sunlight and vitamin D have been inversely associated with the risk of multiple sclerosis (MS). Objective: We investigated sunlight exposure and sun sensitivity in relation to disability progression in MS. Methods: We conducted a survey among persons with MS, registered by the Flemish MS

  7. Photocatalytic oxidation of acetonitrile in aqueous suspension of titanium dioxide irradiated by sunlight

    Energy Technology Data Exchange (ETDEWEB)

    Augugliaro, V.; Bianco Prevot, A.; Caceres Vazquez, J.; Garcia-Lopez, E.; Irico, A.; Loddo, V.; Malato Rodriguez, S.; Marci, G.; Palmisano, L.; Pramauro, E.

    2002-07-01

    The photocatalytic oxidation of acetonitrile (CH{sub 3}CN) was carried out in aqueous suspensions of polycrystalline UiO{sub 2} P25 Degussa irradiated by sunlight. A plus flow photoreactor in a total recycle loop was used for carrying out reactivity experiments in which the concentrations of acetonitrile, of its intermediate oxidation products and of not-purgeable organic carbon (NPOC) were monitored. The influence of the presence of strong oxidant species (H{sub 2}O{sub 2}, S{sub 2}O{sub 8}, CIO) on the process rate was studied. The dependence of acetonitrile photo-oxidation rate on the substrate concentration and on the catalyst amount was also investigated. The photodegradation rate of substrate and NPOC follows a first order kinetics with respect to acetonitrile and NPOC concentrations, respectively. The presence of S{sub {sup O}8}''2- and solar irradiation determines the occurrence of homogeneous degradation of acetonitrile and NPOC. In the presence of irradiated catalyst, a significant synergetic effect is observed for NPOC degradation while for the acetonitrile oxidation this effect is not evident. H{sub 2}O{sub 2} does not effect the process while CIO negatively affects the acetonitrile oxidation rate and it seems to inhibit the NPOC degradation. (Author) 20 refs.

  8. Does sunlight exposure improve survival in patients with non-small cell lung cancer?

    Science.gov (United States)

    Mutlu, Hasan; Buyukcelik, Abdullah; Aksahin, Arzu; Kibar, Mustafa; Cihan, Yasemin Benderli; Kaya, Eser; Seyrek, Ertugrul; Yavuz, Sinan; Erden, Abdulsamet; Calikusu, Zuleyha; Aslan, Tuncay; Akca, Zeki

    2013-01-01

    Some epidemiological studies reported that sunlight exposure and highvitamin D levels may decrease the morbidity and mortality related to cancer. We aimed to evaluate whether sunlight exposure has an impact on survival in patients with non small cell lung cancer. A total of 546 patients with NSCLC from two different regions (Kayseri and Adana) differing according to sunlight exposure were analysed retrospectively. The median overall survival (OS) rates were 11. 6 (CI: 9.50-13.6) and 15.6 months (CI: 12.4-18.8) for Kayseri and Adana, respectively, in all patients (p=0.880). There were no differences between groups in terms of OS. While there is strong evidence regarding inverse relationship between cancer incidence and sunlight exposure, it is still controversial whether sunlight exposure is a good prognostic factor for survival in patients with lung cancer.

  9. Facile fabrication of highly efficient AgI/ZnO heterojunction and its application of methylene blue and rhodamine B solutions degradation under natural sunlight

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Xinjun, E-mail: wxjtg2006@126.com; Wan, Xiaoli; Xu, Xiaoning; Chen, Xuenian

    2014-12-01

    Highlights: • A high-efficiency natural sunlight driven AgI/ZnO photocatalysts have been first prepared. • Our method is a simple, environment-friendly and cost-effective process. • The possible photocatalytic mechanism of AgI/ZnO was proposed. • AgI/ZnO exhibits higher efficiency for the degradation of methylene blue and rhodamine B under natural sunlight than a 500 W Xe lamp. - Abstract: The AgI/ZnO heterojunction was successfully synthesized by in situ deposition method and was found to be a natural sunlight driven photocatalyst. The photocatalytic efficiency of AgI/ZnO was evaluated by the degradation of rhodamine B under visible light irradiation. The influence of various operational parameters such as the effect of loading amount, catalyst dosage and initial RhB concentration on the photodegradation was investigated in detail and the results were discussed. The results indicated that the AgI/ZnO composites displayed much higher photocatalytic performances over ZnO as well as AgI. Moreover, the catalyst obviously showed higher efficiency for the degradation of methylene blue and rhodamine B under natural sunlight than a 500 W Xe lamp, and nearly 100% of dyes were degraded only in 120 min under the optimum conditions. At last, the quenching effects of different scavengers suggested that the reactive • OH and h{sup +} play the major role in the RhB degradation.

  10. Sunlight Exposure, Work Hours, Caffeine Consumption, and Sleep Duration in the Naval Environment.

    Science.gov (United States)

    Shattuck, Nita L; Matsangas, Panagiotis

    2017-06-01

    Sailors in the U.S. Navy are habitual shiftworkers, often experiencing circadian misalignment due to their irregular work/rest schedules. This study assessed the effect of sunlight exposure, work hours, and caffeinated beverage consumption on the daily sleep duration of crewmembers of a U.S. Navy ship during a 2-wk underway period. Working in an artificially lit area with no access to sunlight during work hours, U.S. Navy crew members (N = 91) used daily logs to report their daily activity, caffeinated beverage consumption, and exposure to sunlight while off-duty; sleep was assessed by wrist-worn actigraphy. Hours of sunlight exposure, work duration, and the amount of coffee/tea/soft drinks were statistically significant predictors of sleep duration. On average, crewmembers who reported more than one half-hour of sunlight each day slept on average ∼40 min (10%) less than their peers working the same shifts who received less than one half-hour of sunlight (on average 6.05 ± 0.90 h vs. 6.71 ± 0.91 h, respectively). Exposure to sunlight, work hours, and consumption of caffeinated beverages are important factors when planning watchstanding schedules at sea. Even though further research is needed, our results suggest that even brief exposure to sunlight may contribute to circadian misalignment that negatively affects sleep in the operational environment. Educating crewmembers about sleep hygiene, especially the important roles played by sunlight and caffeine, could potentially improve the sleep and fatigue levels of this population of maritime shiftworkers.Shattuck NL, Matsangas P. Sunlight exposure, work hours, caffeine consumption, and sleep duration in the naval environment. Aerosp Med Hum Perform. 2017; 88(6):579-585.

  11. Concentrating Solar Power

    Energy Technology Data Exchange (ETDEWEB)

    Weinstein, Lee A.; Loomis, James; Bhatia, Bikram; Bierman, David M.; Wang, Evelyn N.; Chen, Gang

    2015-12-09

    Solar energy is a bountiful renewable energy resource: the energy in the sunlight that reaches Earth in an hour exceeds the energy consumed by all of humanity in a year.(1) While the phrase “solar energy conversion” probably brings photovoltaic (PV) cells to mind first, PV is not the only option for generating electricity from sunlight. Another promising technology for solar energy conversion is solar–thermal conversion, commonly referred to as concentrating solar power (CSP).(2) The first utility-scale CSP plants were constructed in the 1980s, but in the two decades that followed, CSP saw little expansion.(3, 4) More recent years, however, have seen a CSP renaissance due to unprecedented growth in the adoption of CSP.(3, 5) Photographs of two operating CSP plants, a parabolic trough collector plant and a central receiver (or “power tower”), are shown here.

  12. Optimized Interdigitated Back Contact (IBC) solar cell for high concentrated sunlight

    Science.gov (United States)

    Verlinden, P.; van de Wiele, F.; Stehelin, G.; David, J. P.

    A one-dimensional analytical model for Interdigitated Back Contact solar cells (IBC), also applicable to Front Surface Field (FSF) and Tandem Junction (TJ) solar cells, is presented. The quantum efficiency, generation current, dark current, and conversion efficiency are calculated as a function of the physical parameters of the cell (doping levels, junction depths, thickness, and lifetime). The proposed model simulates the response of FSF and TJ solar cells more accurately than models using the concept of effective surface recombination velocity. The optimization of parameters (doping level and dimension of each region) is discussed. It is shown that a conversion efficiency of 24.8 percent can be reached under 50 suns. IBC solar cells were fabricated with different substrate resistivities and thicknesses. The experimental results are compared to the theoretical predictions.

  13. 27 CFR 18.65 - Annual report.

    Science.gov (United States)

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Annual report. 18.65... OF THE TREASURY LIQUORS PRODUCTION OF VOLATILE FRUIT-FLAVOR CONCENTRATE Records and Reports § 18.65 Annual report. An annual report, on Form 1695(5520.2), of concentrate plant operations shall be...

  14. High spacecraft potentials on ISEE-1 in sunlight

    Energy Technology Data Exchange (ETDEWEB)

    Whipple, E.C.; Olsen, R.C.

    1987-01-01

    Data from the two electric-field experiments and from the plasma-composition experiment on ISEE-1 show that the spacecraft charged to close to -70 V in sunlight at about 0700 UT on March 17, 1978. Data from the electron-spectrometer experiment show that there was a potential barrier of some -10 to -20 V about the spacecraft during this event. The potential barrier was effective in turning back emitted photoelectrons to the spacecraft. Potential barriers can be formed by differential charging on the spacecraft or by the presence of space charge. The stringent electrostatic cleanliness specifications imposed on ISEE made by the presence of differential charging seem unlikely, if these precautions were effective. Modeling of this event to determine if the barrier was produced by the presence of space charge, suggested that this could not explain the observed barrier. The angular shape of the distribution could be successfully modeled as a product of differential charging on the solar arrays. This implies that the conductive coating was not completely effective in preventing differential charging, and that differential charging did occur.

  15. Sunlight assisted photodegradation by tin oxide quantum dots

    Science.gov (United States)

    Shajira, P. S.; Prabhu, V. Ganeshchandra; Bushiri, M. Junaid

    2015-12-01

    Rutile phase of SnO2 quantum dots of average size of 2.5 nm were synthesized at a growth temperature of 70 °C and characterized with XRD, TEM, FTIR and Raman analysis. The effective strain within the lattice of SnO2 quantum dots was calculated by Williamson-Hall method. The broad peaks in XRD as well as Raman spectra and the presence of Raman bands at 569 and 432 cm-1 are due to lower crystallinity of nanoparticles. The optical band gap of SnO2 quantum dots was increased to 3.75 eV attributed to the quantum size effect. SnO2 quantum dots were annealed in air atmosphere and the crystallite size of the particles increased with annealing temperature. Sunlight assisted photodegration property of SnO2 quantum dots was investigated with vanillin as a model system and it shows the photodegradation efficiency of 87%. The photoluminescence and photodegradation efficiency of nanocrystallite SnO2 decreases with increase of crystallite size contributed to the reduction in population of defects and surface area.

  16. Occupational Sunlight Exposure and Risk of Renal Cell Carcinoma

    Science.gov (United States)

    Karami, Sara; Boffetta, Paolo; Stewart, Patricia; Rothman, Nathaniel; Hunting, Katherine L.; Dosemeci, Mustafa; Berndt, Sonja I.; Brennan, Paul; Chow, Wong-Ho; Moore, Lee E.; Zaridze, David; Mukeria, Anush; Janout, Vladimir; Kollarova, Helena; Bencko, Vladimir; Holcatova, Ivana; Navritalova, Marie; Szeszenia-Dabrowska, Neonila; Mates, Dana; Gromiec, Jan P.

    2010-01-01

    Background Recent findings indicate that vitamin D obtained from ultraviolet (UV) exposure may reduce the risk of a number of different cancers. Vitamin D is metabolized to its active form within the kidney, the major organ for vitamin D metabolism and activity. Since both the incidence of renal cell cancer and prevalence of vitamin D deficiency have increased over the past few decades, this study sought to explore whether occupational UV exposure was associated with renal cell carcinoma (RCC) risk. Methods A hospital-based case-control study of 1,097 RCC cases and 1,476 controls was conducted in four Central and Eastern European countries. Demographic and occupational information was collected to examine the association between occupational UV exposure and RCC risk. Results A significant (24%-38%) reduction in RCC risk was observed with increasing occupational UV exposure among male participants. No association between UV exposure and RCC risk was observed among female participants. When analyses were stratified by latitude as another estimate of sunlight intensity, a stronger (71%-73%) reduction in RCC risk was observed between UV exposure and cancer risk among males residing at the highest latitudes. Conclusion The results of this study suggest that among males there is an inverse association between occupational UV exposure and renal cancer risk. Replication studies are warranted to confirm these results. PMID:20213683

  17. Sunlight and skin cancer: lessons from the immune system.

    Science.gov (United States)

    Ullrich, Stephen E

    2007-08-01

    The ultraviolet (UV) radiation in sunlight induces skin cancer development. Skin cancer is the most common form of human neoplasia. Estimates suggest that in excess of 1.5 million new cases of skin cancer (www.cancer.org/statistics) will be diagnosed in the United States this year. Fortunately, because of their highly visible location, skin cancers are more rapidly diagnosed and more easily treated than other types of cancer. Be that as it may, approximately 10,000 Americans a year die from skin cancer, and the cost of treating skin cancer in the United States (both melanoma and non-melanoma skin cancer) is estimated to be in excess of $2.9 billion a year. In addition to causing skin cancer, UV radiation is also immune suppressive. In fact, data from studies with both experimental animals and biopsy proven skin cancer patients suggest that there is an association between the immune suppressive effects of UV radiation and its carcinogenic potential. Recent studies in my laboratory have focused on understanding the initial molecular events that induce immune suppression. We made two novel observations: first UV-induced keratinocyte-derived platelet activating factor plays a role in the induction of immune suppression. Second, cis-urocanic acid, a skin-derived immunosuppressive compound mediates immune suppression by binding to serotonin receptors on target cells. Recent findings suggest that blocking the binding of these compounds to their receptors not only inhibits UV-induced immune suppression but it also interferes with skin cancer induction.

  18. Photocatalytic Hydrogen Production by Direct Sunlight: A Laboratory Experiment

    Science.gov (United States)

    Koca, Atif; Sahin, Musa

    2003-11-01

    The demand for hydrogen will increase within the next decades as a result of the necessity to produce clean and environmentally and economically accepted fuels from natural and renewable energy resources. In principle, hydrogen has the potential to play an important role in future energy systems because of the diversity of its applications, the variety of ways in which it can be stored, its general environmental advantages, and especially because of the possibility of producing hydrogen by splitting water using photocatalysts and solar energy. Methods and techniques of photocatalytic reactions are covered in some detail in many undergraduate chemistry programs. However, many times in instructional settings, little attention is given to how it is used for the production of hydrogen. In the present investigation a photocatalytic hydrogen production experiment suitable for use in undergraduate chemistry laboratories is described. The experiment can be used to introduce students to the concept of a renewable and sustainable hydrogen energy system of the future, as well as its production techniques, and to demonstrate the use of a CdS/ZnS photocatalyst system for photocatalytic hydrogen production from direct sunlight.

  19. A Concentrator Photovoltaic System Based on a Combination of Prism-Compound Parabolic Concentrators

    Directory of Open Access Journals (Sweden)

    Ngoc Hai Vu

    2016-08-01

    Full Text Available We present a cost-effective concentrating photovoltaic system composed of a prism and a compound parabolic concentrator (P-CPC. In this approach, the primary collector consists of a prism, a solid compound parabolic concentrator (CPC, and a slab waveguide. The prism, which is placed on the input aperture of CPC, directs the incoming sunlight beam to be parallel with the main axes of parabolic rims of CPC. Then, the sunlight is reflected at the parabolic rims and concentrated at the focal point of these parabolas. A slab waveguide is coupled at the output aperture of the CPC to collect focused sunlight beams and to guide them to the solar cell. The optical system was modeled and simulated with commercial ray tracing software (LightTools™. Simulation results show that the optical efficiency of a P-CPC can achieve up to 89%. when the concentration ratio of the P-CPC is fixed at 50. We also determine an optimal geometric structure of P-CPC based on simulation. Because of the simplicity of the P-CPC structure, a lower-cost mass production process is possible. A simulation based on optimal structure of P-CPC was performed and the results also shown that P-CPC has high angular tolerance for input sunlight. The high tolerance of the input angle of sunlight allows P-CPC solar concentrator utilize a single sun tracking system instead of a highly precise dual suntracking system as cost effective solution.

  20. Sunlight activated lanthanide complex for luminescent solar collector applications: effect of waveguide matrix

    Science.gov (United States)

    Shahi, Praveen Kumar; Singh, Priyam; Bahadur Rai, Shyam

    2017-02-01

    The performance of Eu(DBM)3Phen complex (EDP) dispersed in PMMA poly-(methyl methacrylate) polymer matrix, as simple planner luminescent solar collectors (LSCs) is demonstrated using spectroscopic and photovoltaic (PV) measurements. The organic ligands absorb ultra-violet-blue (UV-blue) radiation (220–450 nm) very efficiently and transfer its energy to the Eu3+ ion, which gives an intense red emission even in sunlight exposure. The excellent optical properties of EDP in PMMA permit its coating on the front surface of c-Si solar cell (10  ×  10 cm2) for PV measurements. The PV characterizations reveal the improvement in the short circuit current density (J sc) of PV cell and maximum improvement is found to be 4.6% for 2.5 wt% EDP concentration in PMMA matrix. The efficiency of solar cell increases from 17.22% to 18.33% for bare and 2.5% EDP in PMMA. At a higher concentration of EDP, the thin film starts losing its transparency and hence PV efficiency decreases. These results illustrate that a EDP complex combined with a PV cell could work as a prototype of a new generation solar cell.

  1. Photocatalytic degradation of phenol by iodine doped tin oxide nanoparticles under UV and sunlight irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Al-Hamdi, Abdullah M.; Sillanpää, Mika [Laboratory of Green Chemistry, Lappeenranta University of Technology, Sammonkatu 12, 50130 Mikkeli (Finland); Dutta, Joydeep, E-mail: dutta@squ.edu.om [Chair in Nanotechnology, Water Research Center, Sultan Qaboos University, P.O. Box 17, 123 Al-Khoudh (Oman)

    2015-01-05

    Highlights: • A sol–gel method used to synthesize tin oxide nanoparticles. • Nanoparticles of tin oxide doped with different iodine concentrations. • Degradation studies carried up with UV–vis, TOC, HPLC and GC instruments. • 1% iodine doped tin dioxide showed maximum photodegradation efficiency. - Abstract: Iodine doped tin oxide (SnO{sub 2}:I) nanoparticles were prepared by sol–gel synthesis and their photocatalytic activities with phenol as a test contaminant were studied. In the presence of the catalysts, phenol degradation under direct sunlight was comparable to what was achieved under laboratory conditions. Photocatalytic oxidation reactions were studied by varying the catalyst loading, light intensity, illumination time, pH of the reactant and phenol concentration. Upon UV irradiation in the presence of SnO{sub 2}:I nanoparticles, phenol degrades very rapidly within 30 min, forming carboxylic acid which turns the solution acidic. Phenol degradation rate with 1% iodine doped SnO{sub 2} nanoparticles is at least an order of magnitude higher compared to the degradation achieved through undoped SnO{sub 2} nanoparticles under similar illumination conditions.

  2. The Effect of Sunlight in Parenchyma Pith Cells Diameter of Manihot esculenta

    Science.gov (United States)

    Susanti, D.; Aziz, D. N.; Astuti, W.; Nuraeni, E.

    2017-03-01

    Sunlight is one of the factors that effect on the grow of a plant. Manihot esculenta is one of the plants that easily found in Indonesia because its role as staple food. The aim of this research is to know the correlation between sunlight the grow of parenchyma pith cells diameter of Manihot esculenta. Independent variable in this research is sunlight, and dependent variable is the parenchyma pith cells diameter of Manihot esculenta. Data was collected is in qualitative and quantitative form. Qualitative data gotten gained by morphology observation. The parenchyma pith cells of Manihot esculenta that is affected by sunlight in 1310 x 10 Lux, morphologically has hexagon, cell walls thick, solid state, and regular composition. Meanwhile, the parenchyma pith cells that has less sunlight (363 x 10 Lux) has a hexagon shape, thin cell walls thin, soft state, and irregular composition. Qualitative data suported by quantitative data. The size of parenchyma pith cells diameter that is affected by sunlight in 1310 x 10 Lux 96,4 µm. While, the stem parenchyma pith cells diameter empulur that has less sunlight (363 x 10 Lux) is 129,8 µm.

  3. Formation of DNA strand breaks in peripheral lymphocytes of rats after exposure to natural sunlight.

    Science.gov (United States)

    Rodrigues-Junior, Dorival Mendes; Melo, Ana Amélia de Carvalho; da Silva, Benedito Borges; Lopes-Costa, Pedro Vitor

    2012-04-01

    This paper aims to evaluate the genotoxicity in peripheral blood lymphocytes of rats after exposure to sunlight at different time points of day in a tropical region of Brazil (5 degrees S, 42 degrees W). Thirty Wistar-Hannover rats, three months old, were randomly divided into three groups of 10 animals each: Group I [control, without exposure to ultraviolet (UV) radiation], Group II (exposed to sunlight during 08:00 a.m. to 10:00 a.m.), and Group III (exposed to sunlight during 10:00 a.m. to 12:00 a.m.). After a week of exposure, peripheral blood samples were taken from the tail of these animals to prepare smears on two slides per animal. In 24 h after exposure to sunlight in Group III, a new collection was obtained to observe the repair activity. The alkaline comet assay was used in this study to evaluate the genotoxic activity of sunlight (P exposure to sunlight in Group III showed genotoxic action in comparison to the other groups (P sunlight (UVA-B) in lymphocytes of mammals from 10:00 a.m. to 12:00 a.m., due to a higher intensity of UV in this tropical region.

  4. Low-level liquid scitillation counting for quantification of annual {sup 3}H and {sup 14}C concentrations in tree disks

    Energy Technology Data Exchange (ETDEWEB)

    Kopka, B. [Goettingen Univ. (Germany). Isotopenlaboratorium fuer Biologische und Medizinische Forschung; Schikowski, J. [Goettingen Univ. (Germany). Isotopenlaboratorium fuer Biologische und Medizinische Forschung; Porstendoerfer, J. [Goettingen Univ. (Germany). Isotopenlaboratorium fuer Biologische und Medizinische Forschung

    1997-03-01

    The government of Schleswig Holstein funded a study to perform the retrospective determination of airborne {sup 3}H and {sup 14}C concentrations. It is well known, that in tree rings most of the hydrogen and cabron is fixed after insertion in the matrix of wood and that the radionuclide concentration correlates with former airborne activity concentrations. For the retrospective study wood disks of trees located in the region near the nuclear power plant of Kruemmel and control disks of unsuspected areas were selected. The hydrogen of the wood was transformed to water and the carbon to carbondioxide by classical oxidation processes (combustion in a furnace). The contents of {sup 3}H in the water and {sup 14}C of the carbondioxide (solved in scintillation liquid) were determined by liquid scintillation counting, using a low-level counter (type Quantulus 1220, Wallac). (orig.)

  5. Vitamin D and Sunlight Exposure in Newly-Diagnosed Parkinson's Disease.

    Science.gov (United States)

    Wang, Juan; Yang, Deyu; Yu, Yu; Shao, Gaohai; Wang, Qunbo

    2016-03-04

    Circulating vitamin D has previously been found to be lower in patients with Parkinson's disease (PD), while the effects of sunlight exposure have not yet been fully investigated. Therefore, we evaluated the associations between serum vitamin D, vitamin D intake, sunlight exposure, and newly-diagnosed PD patients in a Chinese population. This case-control study measured serum 25-hydroxyvitamin D (25(OH)D) levels and sunlight exposure in 201 patients with newly-diagnosed PD and 199 controls without neurodegenerative diseases. Data on vitamin D intake and sunlight exposure were obtained using a self-report questionnaire. Multivariable logistic regressions were employed to evaluate the associations between serum 25(OH)D levels, sunlight exposure, and PD. Adjustments were made for sex, age, smoking, alcohol use, education, BMI, and vitamin D intake. There were significantly lower levels of serum 25(OH)D (20.6 ± 6.5 ng/mL), daily vitamin D intake (8.3 ± 3.7 g/day), and sunlight exposure (9.7 ± 4.1 h/week) in patients with PD compared to healthy controls (p sunlight exposure were 1 (reference), 0.809 (0.454, 1.443), 0.623 (0.345, 1.124) and 0.533 (0.294, 0.966), respectively. A significant positive correlation between serum 25(OH)D and sunlight exposure was found, but serum 25(OH)D was not correlated with daily vitamin D intake. This study indicates that lower levels of serum 25(OH)D and sunlight exposure are significantly associated with an increased risk for PD.

  6. Vitamin D and Sunlight Exposure in Newly-Diagnosed Parkinson’s Disease

    Science.gov (United States)

    Wang, Juan; Yang, Deyu; Yu, Yu; Shao, Gaohai; Wang, Qunbo

    2016-01-01

    Circulating vitamin D has previously been found to be lower in patients with Parkinson’s disease (PD), while the effects of sunlight exposure have not yet been fully investigated. Therefore, we evaluated the associations between serum vitamin D, vitamin D intake, sunlight exposure, and newly-diagnosed PD patients in a Chinese population. This case-control study measured serum 25-hydroxyvitamin D (25(OH)D) levels and sunlight exposure in 201 patients with newly-diagnosed PD and 199 controls without neurodegenerative diseases. Data on vitamin D intake and sunlight exposure were obtained using a self-report questionnaire. Multivariable logistic regressions were employed to evaluate the associations between serum 25(OH)D levels, sunlight exposure, and PD. Adjustments were made for sex, age, smoking, alcohol use, education, BMI, and vitamin D intake. There were significantly lower levels of serum 25(OH)D (20.6 ± 6.5 ng/mL), daily vitamin D intake (8.3 ± 3.7 g/day), and sunlight exposure (9.7 ± 4.1 h/week) in patients with PD compared to healthy controls (p sunlight exposure were 1 (reference), 0.809 (0.454, 1.443), 0.623 (0.345, 1.124) and 0.533 (0.294, 0.966), respectively. A significant positive correlation between serum 25(OH)D and sunlight exposure was found, but serum 25(OH)D was not correlated with daily vitamin D intake. This study indicates that lower levels of serum 25(OH)D and sunlight exposure are significantly associated with an increased risk for PD. PMID:26959053

  7. A regionalized national universal kriging model using Partial Least Squares regression for estimating annual PM2.5 concentrations in epidemiology.

    Science.gov (United States)

    Sampson, Paul D; Richards, Mark; Szpiro, Adam A; Bergen, Silas; Sheppard, Lianne; Larson, Timothy V; Kaufman, Joel D

    2013-08-01

    Many cohort studies in environmental epidemiology require accurate modeling and prediction of fine scale spatial variation in ambient air quality across the U.S. This modeling requires the use of small spatial scale geographic or "land use" regression covariates and some degree of spatial smoothing. Furthermore, the details of the prediction of air quality by land use regression and the spatial variation in ambient air quality not explained by this regression should be allowed to vary across the continent due to the large scale heterogeneity in topography, climate, and sources of air pollution. This paper introduces a regionalized national universal kriging model for annual average fine particulate matter (PM2.5) monitoring data across the U.S. To take full advantage of an extensive database of land use covariates we chose to use the method of Partial Least Squares, rather than variable selection, for the regression component of the model (the "universal" in "universal kriging") with regression coefficients and residual variogram models allowed to vary across three regions defined as West Coast, Mountain West, and East. We demonstrate a very high level of cross-validated accuracy of prediction with an overall R(2) of 0.88 and well-calibrated predictive intervals. In accord with the spatially varying characteristics of PM2.5 on a national scale and differing kriging smoothness parameters, the accuracy of the prediction varies by region with predictive intervals being notably wider in the West Coast and Mountain West in contrast to the East.

  8. [Progress in research of association between myopia and sunlight exposure in children].

    Science.gov (United States)

    Zhai, L L; Wu, X Y; Xu, S J; Tao, F B

    2016-11-10

    Myopia has become a major health problem on global scale due to its increasing high prevalence in the past few decades and gradual younger onset age. Accumulated epidemiological surveys have shown that decreased time of exposure to sunlight would be an inducement for the development of myopia. Increasing time spent outdoors and exposure to sunlight might be the most cost-effective and effective measure for children to prevent myopia. This paper summarizes the progress in research of the association between sunlight exposure and myopia in children and its mechanisms to provide new clues for the research on myopia prevention and control.

  9. Effect of sunlight on the survival of pathogenic E. coli in freshwater and sea water

    DEFF Research Database (Denmark)

    Surendraraj, Alagarsamy; Farvin, Sabeena; Thampuran, N.

    2011-01-01

    An enteropathogenic group of E. coli are the emerging category of pathogen of public health significance. Several recent pathogenic E. coli outbreaks are associated with drinking water. Aquaculture, the fast emerging food production sector also poses a pathogenic EHEC outbreak risk, as it regularly......) were studied for their survival under sunlight and darkness in fresh water and seawater. Effect of direct sunlight on the viable but nonculturable (VBNC) state of cultures was also studied. The results of the study indicated a distinct pattern between freshwater system and seawater system. Pathogenic E....... coli from different sources showed significantly higher level of destruction under direct sunlight than in complete darkness. A reduction of 1.1 to 5.7 log CFU was seen in fresh water after 90 to 105 min under direct sunlight and only 0.2 to 2 log reduction was observed in complete darkness in 5 to 96...

  10. Application of photoremovable protecting group for controlled release of plant growth regulators by sunlight.

    Science.gov (United States)

    Atta, Sanghamitra; Ikbal, Mohammed; Kumar, Ashutosh; Pradeep Singh, N D

    2012-06-01

    We report a novel technique for controlled release of plant growth regulators (PGRs) by sunlight using photoremovable protecting group (PRPG) as a delivery device. In the present work, carboxyl-containing PGRs of the auxin group [indoleacetic acid (IAA) and naphthoxyacetic acid (NOAA)] were chemically caged using PRPGs of coumarin derivatives. Photophysical studies showed that caged PGRs exhibited good fluorescence properties. Irradiation of caged PGRs by sunlight in both aqueous ethanol and soil media resulted in controlled release of PGRs. The results of the bioactivity experiments indicated that caged PGRs showed better enhancement in the root and shoot length growth of Cicer arietinum compared to PGRs after 10days of sunlight exposure. Our results indicated that use of PRPG as a delivery device for controlled release of PGRs by sunlight in soil holds great interest for field application since it can overcome the rapid loss of PGRs in environmental conditions.

  11. Sunlight affects aggregation and deposition of graphene oxide in the aquatic environment.

    Science.gov (United States)

    In this study, we investigate the role of simulated sunlight on the physicochemical properties, aggregation, and deposition of graphene oxide (GO) in aquatic environments. Results show that light exposure under varied environmental conditions significantly impacts the physicochem...

  12. Toxicological impact of cadmium-based quantum dots towards aquatic biota: Effect of natural sunlight exposure

    Energy Technology Data Exchange (ETDEWEB)

    Silva, B.F. [Department of Biology, Faculty of Science, University of Porto, Rua do Campo Alegre, 4169-007 Porto (Portugal); CIIMAR, Interdisciplinary Centre of Marine and Environmental Research, Rua dos Bragas, 289, 4050-123 Porto (Portugal); Andreani, T. [Centro de Investigação em Química da Universidade do Porto, Rua do Campo Alegre, 687, 4169-007 Porto (Portugal); Department of Chemistry and Biochemistry, Faculty of Science, University of Porto, Rua do Campo Alegre, 4169-007 Porto (Portugal); CITAB − Centre for Research and Technology of Agro-Environmental and Biological Sciences, University of Trás-os-Montes e Alto Douro, UTAD, Vila Real (Portugal); Gavina, A., E-mail: anacsgavina@gmail.com [Department of Biology, Faculty of Science, University of Porto, Rua do Campo Alegre, 4169-007 Porto (Portugal); CIIMAR, Interdisciplinary Centre of Marine and Environmental Research, Rua dos Bragas, 289, 4050-123 Porto (Portugal); Vieira, M.N. [Department of Biology, Faculty of Science, University of Porto, Rua do Campo Alegre, 4169-007 Porto (Portugal); CIIMAR, Interdisciplinary Centre of Marine and Environmental Research, Rua dos Bragas, 289, 4050-123 Porto (Portugal); Pereira, C.M. [Centro de Investigação em Química da Universidade do Porto, Rua do Campo Alegre, 687, 4169-007 Porto (Portugal); Department of Chemistry and Biochemistry, Faculty of Science, University of Porto, Rua do Campo Alegre, 4169-007 Porto (Portugal); Rocha-Santos, T. [Department of Chemistry and Centre for Environmental and Marine Studies (CESAM), University of Aveiro, Campus de Santiago, 3810-193 Aveiro (Portugal); and others

    2016-07-15

    Highlights: • Under sunlight exposure, all QDs form particle aggregates in the different media. • CdSeS/ZnS QDs showed lower toxic effects to V. fischeri before sunlight exposure. • Sunlight exposure decreased the toxicity of CdS 480 in all organisms. • Sunlight exposure increased the toxicity of CdS 380 QDs for D. magna. • Shell of QDs seemed to make them less harmful to aquatic organisms. - Abstract: Cadmium-based quantum dots (QDs) are increasingly applied in existent and emerging technologies, especially in biological applications due to their exceptional photophysical and functionalization properties. However, they are very toxic compounds due to the high reactive and toxic cadmium core. The present study aimed to determine the toxicity of three different QDs (CdS 380, CdS 480 and CdSeS/ZnS) before and after the exposure of suspensions to sunlight, in order to assess the effect of environmentally relevant irradiation levels in their toxicity, which will act after their release to the environment. Therefore, a battery of ecotoxicological tests was performed with organisms that cover different functional and trophic levels, such as Vibrio fischeri, Raphidocelis subcapitata, Chlorella vulgaris and Daphnia magna. The results showed that core-shell type QDs showed lower toxic effects to V. fischeri in comparison to core type QDs before sunlight exposure. However, after sunlight exposure, there was a decrease of CdS 380 and CdS 480 QD toxicity to bacterium. Also, after sunlight exposure, an effective decrease of CdSeS/ZnS and CdS 480 toxicity for D. magna and R. subcapitata, and an evident increase in CdS 380 QD toxicity, at least for D. magna, were observed. The results of this study suggest that sunlight exposure has an effect in the aggregation and precipitation reactions of larger QDs, causing the degradation of functional groups and formation of larger bulks which may be less prone to photo-oxidation due to their diminished surface area. The same

  13. On-line slurry viscosity and concentration measurement as a real-time waste stream characterization tool. 1997 annual progress report

    Energy Technology Data Exchange (ETDEWEB)

    Powell, R.L. [Univ. of California, Davis, CA (US). Dept. of Chemical Engineering and Materials Science; Shekarriz, A. [Pacific Northwest National Lab., Richland, WA (US)

    1997-01-01

    'The main scope of this work is to: (1) develop a novel tomographic ultrasonic technique to obtain the real-time distribution of acoustic velocity and flow velocity; (2) use nuclear magnetic resonance imaging (NMRI) to measure velocity profiles and rheological properties of complex fluids and suspensions; (3) establish a facility for making laser Doppler velocimetry (LDV) measurements that can be The overall goal is to obtain real-time rheology and solids concentration within a solid-liquid suspension flowing in a pipeline. To nondestructively obtain the rheology of the fluid flowing in a pipe, accurate measurement of local shear rate distribution is required. This objective was met by using two real-time tomographic techniques: an ultrasonic Doppler velocimetry system and an NMRI system. The first method combines the existing state-of-the-art ultrasonic velocimetry technology base with a novel tomographic concept to non-intrusively obtain high resolution acoustic and flow velocity profile at a section of the flow field. The acoustic velocity profile provides a means of improving the flow velocity measurement accuracy. These data are also, used to yield the profile of solids concentration. In addition, the volumetric flow rate was determined from integration of the velocity profile. From the knowledge of the concentration profile the mass flow rate can also be determined, Similar work was undertaken for the NMNRI system. In this case, single phase Newtonian fluids have been used to model complex rheological behavior. Finally, a LDV system has been purchased and set - up in the laboratory at UC Davis.'

  14. Sunlight inactivation of faecal bacteria in waste stabilization ponds in a Sahelian region (Ouagadougou, Burkina Faso)

    Energy Technology Data Exchange (ETDEWEB)

    Maiga, Y.; Denyigba, K.; Wethe, J.; Ouattara, A. S.

    2009-07-01

    Waste stabilization ponds (WSPs) are an appropriate sewage treatment system for developing countries in Sahelian regions. Several studies on wastewater treatment in WSPs have shown that solar radiation is a major factor in the inactivation of faecal indicator, and that sunlight acts on interaction with other factors including dissolved oxygen (DO) and pH. However, the inactivation by sunlight is limited by the reduction of light penetration in ponds. (Author)

  15. First field-based atmospheric observation of the reduction of reactive mercury driven by sunlight

    Science.gov (United States)

    de Foy, Benjamin; Tong, Yindong; Yin, Xiufeng; Zhang, Wei; Kang, Shichang; Zhang, Qianggong; Zhang, Guoshuai; Wang, Xuejun; Schauer, James J.

    2016-06-01

    Hourly speciated measurements of atmospheric mercury made in a remote, high-altitude site in the Tibetan Plateau revealed the first field observations of the reduction of reactive mercury in the presence of sunlight in the atmosphere. Measurements were collected over four winter months on the shore of Nam Co Lake in the inland Tibetan Plateau. The data was analyzed to identify sources and atmospheric transformations of the speciated mercury compounds. The absence of local anthropogenic sources provided a unique opportunity to examine chemical transformations of mercury. An optimization algorithm was used to determine the parameters of a chemical box model that would match the measured reactive mercury concentrations. This required the presence of a photolytic reduction reaction previously observed in laboratory studies and in power plant plumes. In addition, the model estimated the role of vertical mixing in diluting reactive gaseous mercury during the day, and the role of bromine chemistry in oxidizing gaseous elemental mercury to produce reactive gaseous mercury. This work provides further evidence of the need to add the photolytic reduction reaction of oxidized mercury into atmospheric transport models in order to better simulate mercury deposition.

  16. The influence of short-term exposure to tropical sunlight on boar seminal characteristics

    Science.gov (United States)

    Egbunike, G. N.; Dede, T. I.

    1980-06-01

    The seminal characteristics of 4 Large White boars exposed to direct tropical sunlight 45 min daily for three days were compared to those of their mates that were maintained under shade in the barn. During the period of exposure, both respiratory rate and rectal temperature increased significantly by 276.84 and 5.13% respectively in the exposed over the unexposed boars, thus indicating a high degree of hyperthermia. Although libido, as judged from the reaction time, was unaffected, the ejaculation time appeared to be longer for the stressed than unstressed animals. Gel mass, semen volume and pH appeared to be stable inspite of the treatment, unlike sperm motility and concentration which deteriorated. Also, the dehydrogenase activity of the semen was inferior in the stressed animals. Sperm output per ejaculate dropped drastically only in the week following exposure from 58.22 to 28.42 billion sperm as compared to corresponding values of 54.83 and 47.87 by the unexposed boars. Similarly, the frequency of sperm abnormality was higher in the stressed boars in this period after which the animals appeared to have recovered.

  17. Photocatalytic degradation of five sulfonylurea herbicides in aqueous semiconductor suspensions under natural sunlight.

    Science.gov (United States)

    Fenoll, José; Hellín, Pilar; Flores, Pilar; Martínez, Carmen María; Navarro, Simón

    2012-05-01

    In the present study, the photocatalytic degradation of five sulfonylurea herbicides (chlorsulfuron, flazasulfuron, nicosulfuron, sulfosulfuron and triasulfuron) has been investigated in aqueous suspensions of zinc oxide (ZnO), tungsten (VI) oxide (WO(3)), tin (IV) oxide (SnO(2)) and zinc sulfide (ZnS) at pilot plant scale under natural sunlight. Photocatalytic experiments, especially those involving ZnO photocatalysis, showed that the addition of semiconductors in tandem with the oxidant (Na(2)S(2)O(8)) strongly enhances the degradation rate of the herbicides in comparisons carried out with photolytic tests. The degradation of the herbicides follows a first order kinetics according to the Langmuir-Hinshelwood model. In our conditions, the amount of time required for 50% of the initial pesticide concentration to dissipate (t(½)) ranged from 8 to 27 min (t(30W)=0.3-1.2 min) for sulfosulfuron and chlorsulfuron, respectively in the ZnO/Na(2)S(2)O(8) system. None of the studied herbicides was found after 120 min of illumination (except chlorsulfuron, 0.2 μg L(-1)).

  18. Water balance of goats in Jeneponto - South Sulawesi under sunlight exposure and water restriction

    Directory of Open Access Journals (Sweden)

    Djoni Prawira Rahardja

    2007-10-01

    Full Text Available Water balance of 5 does of Kacang goat of Jeneponto was studied under the condition of sunlight exposure and water restriction. The study was conducted in dry season with 4 consecutive treatments of 10 d with 4-5 d of adjustment period between two consecutive treatments: (1 indoor and unrestricted water; (2 indoor and restricted water; (3 10 h outdoor–and unrestricted water; (4 10 h outdoor – restricted water. The maximum air temperature of outdoor was 39.3OC, and it was 30OC in the indoor environment. In all treatments, the animals were placed in the individual crates. The plasma volume of the goats was higher under sunlight exposure, but it decreased by water restriction, while hematocrite value indicated a reverse responses. Sunlight exposure did not significantly decrease the intake and digestion of organic matter, but water restriction affected significantly and this effect was higher under sunlight exposre. The proportions of water loss through every avenue were maintained relatively constant either under water restriction or sunlight exposure in which the respration rate increased significantly. The findings suggest that sunlight exposure with unrestricted water resulted in a positive water balance without a significant change in organic matter intake and utilization. Water restriction resulted in a negative water balance, reducing organic matter intake and utilization. As the adaptive mechanisms, the goat appeared to be able to withstand in the harsh environment of Jeneponto by expanding plasma volume, increasing body temperature and respiration rate.

  19. Sunlight regulates the cutaneous production of vitamin D3 by causing its photodegradation

    Energy Technology Data Exchange (ETDEWEB)

    Webb, A.R.; DeCosta, B.R.; Holick, M.F.

    1989-05-01

    Exposure to sunlight initiates the formation of vitamin D3 in skin as the UV B radiation in the solar spectrum causes the photoconversion of 7-dehydrocholesterol to previtamin D3. A heat-induced isomerization then converts previtamin D3 to vitamin D3 over a period of days. A number of irradiation products of vitamin D3 are known to form upon irradiation with high intensity UV radiation, but the effect of subsequent exposures to sunlight on the vitamin D3 formed in skin is not known. To investigate this phenomenon, human skin containing vitamin D3 was exposed to sunlight in Boston. A model system of (/sup 3/H)vitamin D3 in methanol was also used to study the effects of sunlight on vitamin D3 throughout the year. Vitamin D3 proved to be exquisitely sensitive to sunlight, and once formed in the skin, exposure to sunlight resulted in its rapid photodegradation to a variety of photoproducts, including 5,6-transvitamin D3, suprasterol I, and suprasterol II.

  20. Measurement of activity concentrations of {sup 40}K, 2{sup 32T}h and {sup 238}U in TSP aerosols and the associated inhalation annual effective radiation dose to the public in Gosan site, Jeju

    Energy Technology Data Exchange (ETDEWEB)

    Han, Chung Hun; Park, Youn Hyun; Park, Jae Woo [Jeju National University, Jeju (Korea, Republic of)

    2016-10-15

    Gamma radiation emitted from naturally occurring radioisotopes, such as 40K and the radionuclides from the {sup 232}Th and {sup 238}U series and their decay products, which exist at trace levels in all ground formations, represents the main external source of irradiation to the human body. The objective of the current study is to determine the activity concentrations of 40K, {sup 232}Th and {sup 238}U in airborne TSP and the associated internal radiation dose to the public due to inhalation in Gosan site, Jeju Island, Korea. The atmospheric total suspended particulates (TSP) aerosols were collected at Gosan site of Jeju Island, which is one of the background sites of Korea, during January to April 2013. This study analyzed using ICP-DRC-MS the concentrations of potassium, uranium and thorium, and evaluated the annual effective dose by breathing from the results. The correlations between the studied natural isotopes is a good positive correlation between {sup 232}Th and {sup 238}U, supporting the conclusion that they originated from the same source, mostly the crust. The backward trajectory analysis has confirmed that the 40K, {sup 238}U and {sup 232}Th are delivered as the air masses have moved from the China continent. The inhalation annual effective radiation dose (default mode F) to the public due to natural isotopes of the airborne TSP was in the range 16.195 - 77.051 nSv/y, depending on the age group. Jeju Island with less pollution source and low population density is also one of the best places as a background area in Asia.

  1. Beam-Forming Concentrating Solar Thermal Array Power Systems

    Science.gov (United States)

    Cwik, Thomas A. (Inventor); Dimotakis, Paul E. (Inventor); Hoppe, Daniel J. (Inventor)

    2016-01-01

    The present invention relates to concentrating solar-power systems and, more particularly, beam-forming concentrating solar thermal array power systems. A solar thermal array power system is provided, including a plurality of solar concentrators arranged in pods. Each solar concentrator includes a solar collector, one or more beam-forming elements, and one or more beam-steering elements. The solar collector is dimensioned to collect and divert incoming rays of sunlight. The beam-forming elements intercept the diverted rays of sunlight, and are shaped to concentrate the rays of sunlight into a beam. The steering elements are shaped, dimensioned, positioned, and/or oriented to deflect the beam toward a beam output path. The beams from the concentrators are converted to heat at a receiver, and the heat may be temporarily stored or directly used to generate electricity.

  2. Using ocean-glint scattered sunlight as a diagnostic tool for satellite remote sensing of greenhouse gases

    Directory of Open Access Journals (Sweden)

    A. Butz

    2013-09-01

    Full Text Available Spectroscopic measurements of sunlight backscattered by the Earth's surface is a technique widely used for remote sensing of atmospheric constituent concentrations from space. Thereby, remote sensing of greenhouse gases poses particularly challenging accuracy requirements for instrumentation and retrieval algorithms which, in general, suffer from various error sources. Here, we investigate a method that helps disentangle sources of error for observations of sunlight backscattered from the glint spot on the ocean surface. The method exploits the backscattering characteristics of the ocean surface, which is bright for glint geometry but dark for off-glint angles. This property allows for identifying a set of clean scenes where light scattering due to particles in the atmosphere is negligible such that uncertain knowledge of the lightpath can be excluded as a source of error. We apply the method to more than 3 yr of ocean-glint measurements by the Thermal And Near infrared Sensor for carbon Observation (TANSO Fourier Transform Spectrometer (FTS onboard the Greenhouse Gases Observing Satellite (GOSAT, which aims at measuring carbon dioxide (CO2 and methane (CH4 concentrations. The proposed method is able to clearly monitor recent improvements in the instrument calibration of the oxygen (O2 A-band channel and suggests some residual uncertainty in our knowledge about the instrument. We further assess the consistency of CO2 retrievals from several absorption bands between 6400 cm−1 (1565 nm and 4800 cm−1 (2100 nm and find that the absorption bands commonly used for monitoring of CO2 dry air mole fractions from GOSAT allow for consistency better than 1.5 ppm. Usage of other bands reveals significant inconsistency among retrieved CO2 concentrations pointing at inconsistency of spectroscopic parameters.

  3. Using ocean-glint scattered sunlight as a diagnostic tool for satellite remote sensing of greenhouse gases

    Directory of Open Access Journals (Sweden)

    A. Butz

    2013-05-01

    Full Text Available Spectroscopic measurements of sunlight backscattered by the Earth's surface is a technique widely used for remote sensing of atmospheric constituent concentrations from space. Thereby, remote sensing of greenhouse gases poses particularly challenging accuracy requirements for instrumentation and retrieval algorithms which, in general, suffer from various error sources. Here, we investigate a method that helps disentangle sources of error for observations of sunlight backscattered from the glint spot on the ocean surface. The method exploits the backscattering characteristics of the ocean surface which is bright for glint geometry but dark for off-glint angles. This property allows for identifying a set of clean scenes where light scattering due to particles in the atmosphere is negligible such that uncertain knowledge of the lightpath can be excluded as a source of error. We apply the method to more than 3 yr of ocean-glint measurements by the Thermal And Near infrared Sensor for carbon Observation (TANSO – Fourier Transform Spectrometer (FTS onboard the Greenhouse Gases Observing Satellite (GOSAT which aims at measuring carbon dioxide (CO2 and methane (CH4 concentrations. The proposed method is able to clearly monitor recent improvements in the instrument calibration of the oxygen (O2 A-band channel and suggests some residual uncertainty in our knowledge about the instrument. We further assess the consistency of CO2 retrievals from several absorption bands between 6400 cm−1 (1565 nm and 4800 cm−1 (2100 nm and find that the absorption bands commonly used for monitoring of CO2 dry air mole fractions from GOSAT allow for consistency better than 1.5 ppm. Usage of other bands reveals significant inconsistency among retrieved CO2 concentrations pointing at inconsistency of spectroscopic parameters.

  4. 2001-2010年非洲大气PM2.5污染浓度空间格局演化%Spatial pattern evolution of annual average PM2.5 concentration in Africa, 2001-2010

    Institute of Scientific and Technical Information of China (English)

    杨帆; 周亮; 林蔚; 徐建刚

    2016-01-01

    基于NASA的全球大气PM2.5年均污染浓度栅格数据,通过区统计非洲各国大气PM2.5浓度均值及建立空间数据库,利用重力模型、ESDA模型及GIS空间统计分析方法,对非洲52个主要国家(地区)2001年~2010年间的大气PM2.5污染浓度空间格局演化特征进行探究,并依据时间序列特征将研究对象划分为8类。研究结果表明:淤2001年~2010年非洲大气PM2.5污染浓度大致呈现“中间高、南北低;西部高、东部低”的空间特征;其中高值区集中分布在非洲西部几内亚湾附近的尼日利亚、刚果与喀麦隆等国家,低值区则广泛地分布在北非、南非以及非洲东南部印度洋沿岸地区或岛屿。于基于ESDA模型的空间自相关分析发现PM2.5浓度“高—高”热点区主要集聚在几内亚湾附近,“低—低”冷点区集中在东南部印度洋沿岸的南非、莫桑比克与马达加斯加岛。盂时序上2001年~2010年非洲PM2.5年平均污染浓度呈现明显下降趋势,其中32个国家2010年PM2.5污染年均浓度低于2001年。榆从自然环境条件及社会经济因素两方面浅析其空间格局主要成因:几内亚湾沿岸是非洲PM2.5污染最严重的地区,因其人口稠密且高度依赖石油产业;非洲东南部地区PM2.5污染最轻,得益于其良好的自然环境条件及低污染的支柱产业。%Based on NASA’s global annual average PM2.5 grids, by vectoring the administrative boundaries of African countries, calculating the average con-centration of atmospheric PM2.5 of all countries and building the spatial database, using gravity model, ESDA model and GIS spatial statistical analysis method, we explore the spatial pattern evolution of the atmospheric PM2.5 pol-lution concentration of 52 main African countries from 2001 to 2010. According to their time series features, we classify them into 8 types. The results show that: (1) The concentration of

  5. PRKCZ methylation is associated with sunlight exposure in a North American but not a Mediterranean population.

    Science.gov (United States)

    Aslibekyan, Stella; Dashti, Hassan S; Tanaka, Toshiko; Sha, Jin; Ferrucci, Luigi; Zhi, Degui; Bandinelli, Stefania; Borecki, Ingrid B; Absher, Devin M; Arnett, Donna K; Ordovas, Jose M

    2014-11-01

    Sunlight exposure has been shown to alter DNA methylation patterns across several human cell-types, including T-lymphocytes. Since epigenetic changes establish gene expression profiles, changes in DNA methylation induced by sunlight exposure warrant investigation. The purpose of this study was to assess the effects of sunlight exposure on CD4+ T-cell methylation patterns on an epigenome-wide scale in a North American population of European origin (n=991). In addition, we investigated the genetic contribution to epigenetic variation (methylQTL). We used linear regression to test the associations between methylation scores at 461,281 cytosine-phosphate-guanine (CpG) sites and sunlight exposure, followed by a genome-wide association analysis (methylQTL) to test for associations between methylation at the top CpG locus and common genetic variants, assuming an additive genetic model. We observed an epigenome-wide significant association between sunlight exposure and methylation status at cg26930596 (p=9.2×10(-8)), a CpG site located in protein kinase C zeta (PRKCZ), a gene previously shown to be entrained by light. MethylQTL analysis resulted in significant associations between cg26930596 and two intergenic single nucleotide polymorphisms on chromosome 3, rs4574216 (p=1.5×10(-10)) and rs4405858 (p=1.9×10(-9)). These common genetic variants reside downstream of WWTR1, a transcriptional co-activator of PRKCZ. Associations observed in the North American population, however, did not replicate in an independent Mediterranean cohort. Our preliminary results support the role of sunlight exposure in epigenetic processes, and lay the groundwork for future studies of the molecular link between sunlight and physiologic processes such as tumorigenesis and metabolism.

  6. HISTORY OF SUNLIGHT EXPOSURE IS A RISK FACTOR FOR AGE-RELATED MACULAR DEGENERATION.

    Science.gov (United States)

    Schick, Tina; Ersoy, Lebriz; Lechanteur, Yara T E; Saksens, Nicole T M; Hoyng, Carel B; den Hollander, Anneke I; Kirchhof, Bernd; Fauser, Sascha

    2016-04-01

    To evaluate effects of current and past sunlight exposure and iris color on early and late age-related macular degeneration (AMD). Of 3,701 individuals from the EUGENDA database, 752 (20.3%) showed early AMD, 1,179 (31.9%) late AMD, and 1,770 (47.8%) were controls. Information about current and past sunlight exposure, former occupation type, subdivided in indoor working and outdoor working, and iris color were obtained by standardized interviewer-assisted questionnaires. Associations between environmental factors adjusted for age, gender, and smoking and early and late AMD were performed by multivariate regression analysis. Current sunlight exposure showed no association with early AMD or late AMD, but past sunlight exposure (≥8 hours outside daily) was significantly associated with early AMD (odds ratio: 5.54, 95% confidence interval 1.25-24.58, P = 0.02) and late AMD (odds ratio: 2.77, 95% confidence interval 1.25-6.16, P = 0.01). Outside working was found to be associated with late AMD (odds ratio: 2.57, 95% confidence interval 1.89-3.48, P = 1.58 × 10). No association was observed between iris color and early or late AMD. Sunlight exposure during working life is an important risk factor for AMD, whereas sunlight exposure after retirement seems to have less influence on the disease development. Therefore, preventive measures, for example, wearing sunglasses to minimize sunlight exposure, should start early to prevent development of AMD later in life.

  7. Toxicological impact of cadmium-based quantum dots towards aquatic biota: Effect of natural sunlight exposure.

    Science.gov (United States)

    Silva, B F; Andreani, T; Gavina, A; Vieira, M N; Pereira, C M; Rocha-Santos, T; Pereira, R

    2016-07-01

    Cadmium-based quantum dots (QDs) are increasingly applied in existent and emerging technologies, especially in biological applications due to their exceptional photophysical and functionalization properties. However, they are very toxic compounds due to the high reactive and toxic cadmium core. The present study aimed to determine the toxicity of three different QDs (CdS 380, CdS 480 and CdSeS/ZnS) before and after the exposure of suspensions to sunlight, in order to assess the effect of environmentally relevant irradiation levels in their toxicity, which will act after their release to the environment. Therefore, a battery of ecotoxicological tests was performed with organisms that cover different functional and trophic levels, such as Vibrio fischeri, Raphidocelis subcapitata, Chlorella vulgaris and Daphnia magna. The results showed that core-shell type QDs showed lower toxic effects to V. fischeri in comparison to core type QDs before sunlight exposure. However, after sunlight exposure, there was a decrease of CdS 380 and CdS 480 QD toxicity to bacterium. Also, after sunlight exposure, an effective decrease of CdSeS/ZnS and CdS 480 toxicity for D. magna and R. subcapitata, and an evident increase in CdS 380 QD toxicity, at least for D. magna, were observed. The results of this study suggest that sunlight exposure has an effect in the aggregation and precipitation reactions of larger QDs, causing the degradation of functional groups and formation of larger bulks which may be less prone to photo-oxidation due to their diminished surface area. The same aggregation behaviour after sunlight exposure was observed for bare QDs. These results further emphasize that the shell of QDs seems to make them less harmful to aquatic biota, both under standard environmental conditions and after the exposure to a relevant abiotic factor like sunlight. Copyright © 2016 Elsevier B.V. All rights reserved.

  8. Wintering birds avoid warm sunshine: predation and the costs of foraging in sunlight.

    Science.gov (United States)

    Carr, Jennie M; Lima, Steven L

    2014-03-01

    Wintering birds can gain significant thermal benefits by foraging in direct sunlight. However, exposure to bright sunlight might make birds easier to detect by predators and may also cause visual glare that can reduce a bird's ability to monitor the environment. Thus, birds likely experience a trade-off between the thermal benefits and predation-related costs of foraging in direct sunlight. To examine this possible thermoregulation-predation trade-off, we monitored the behavior of mixed-species flocks of wintering emberizid sparrows foraging in alternating strips of sunlight and shade. On average, these sparrows routinely preferred to forage in the shade, despite midday air temperatures as much as 30 °C below their thermoneutral zone. This preference for shade was strongest at relatively high temperatures when the thermal benefits of foraging in sunlight were reduced, suggesting a thermoregulation-predation trade-off. Glare could be reduced if birds faced away from the sun while feeding in direct sunlight, but we found that foraging birds tended to face southward (the direction of the sun). We speculate that other factors, such as the likely direction of predator approach, may explain this southerly orientation, particularly if predators use solar glare to their advantage during an attack. This interpretation is supported by the fact that birds had the weakest southerly orientation on cloudy days. Wintering birds may generally avoid foraging in direct sunlight to minimize their risk of predation. However, given the thermal benefits of sunshine, such birds may benefit from foraging in habitats that provide a mosaic of sunlit and shaded microhabitats.

  9. Natural sunlight shapes crude oil-degradingbacterial communities in northern Gulf of Mexico surface waters

    Directory of Open Access Journals (Sweden)

    Hernando P Bacosa

    2015-12-01

    Full Text Available Following the Deepwater Horizon (DWH spill in 2010, an enormous amount of oil was observed in the deep and surface waters of the northern Gulf of Mexico. Surface waters are characterized by intense sunlight and high temperature during summer. While the oil-degrading bacterial communities in the deep-sea plume have been widely investigated, the effect of natural sunlight on those in oil polluted surface waters remains unexplored to date. In this study, we incubated surface water from the DWH site with amendments of crude oil, Corexit dispersant, or both for 36 d under natural sunlight in the northern Gulf of Mexico. The bacterial community was analyzed over time for total abundance, density of alkane and polycyclic aromatic hydrocarbon degraders, and community composition via pyrosequencing. Our results showed that, for treatments with oil and/or Corexit, sunlight significantly reduced bacterial diversity and evenness and was a key driver of shifts in bacterial community structure. In samples containing oil or dispersant, sunlight greatly reduced abundance of the Cyanobacterium Synechococcus but increased the relative abundances of Alteromonas, Marinobacter, Labrenzia, Sandarakinotalea, Bartonella, and Halomonas. Dark samples with oil were represented by members of Thalassobius, Winogradskyella, Alcanivorax, Formosa, Pseudomonas, Eubacterium, Erythrobacter, Natronocella, and Coxiella. Both oil and Corexit inhibited the Candidatus Pelagibacter with or without sunlight exposure. For the first time, we demonstrated the effects of light in structuring microbial communities in water with oil and/or Corexit. Overall, our findings improve understanding of oil pollution in surface water, and provide unequivocal evidence that sunlight is a key factor in determining bacterial community composition and dynamics in oil polluted marine waters.

  10. Annual hydrogen, carbon monoxide and carbon dioxide concentrations and surface to air exchanges in a rural area (Québec, Canada)

    Science.gov (United States)

    Constant, Philippe; Poissant, Laurier; Villemur, Richard

    The industrialization and the demographic expansion have both influenced the biogeochemical cycle of hydrogen (H 2), carbon monoxide (CO) and carbon dioxide (CO 2). In the actual context, knowledge about the spatial distribution of the natural sources and sinks of these trace gases is then crucial to infer possible effects of climate and land use changes on their global budget. This article reports the H 2, CO and CO 2 concentrations and micrometeorological fluxes measured during 1 year in a rural area of the mixed wood ecozone of Canada. Land use represents a critical issue in the control of trace gas natural sources or sinks of that region, which is the most densely habited in Canada. On average, the site emitted CO 2 at a rate of 7.7 g m -2 d -1 and consumed H 2 and CO at 0.34 and 5.1 mg m -2 d -1, respectively. Temperature was the most important factor affecting the H 2 and CO surface to air exchanges. The strength of the soil sink was maximal at the end of the summer, while H 2 and CO emissions were observed at the snow-melting period. In winter, H 2 and CO depositions were attributed to their oxidation by photochemically active compounds within the snow cover. When soil temperature was above 10 °C, trace gas fluxes followed a well-defined diurnal cycle. H 2 and CO 2 deposition rates were positively correlated with H 2O fluxes, while CO followed the inverse trend. CO 2 diurnal variations resulted from a balance between photosynthesis and soil respiration, while some biotic and abiotic factors were proposed to explain the trend observed for H 2. In the case of CO, emissions originating from heat- and photo-induced reactions were involved in the attenuation in the strength of the soil sink during daytime. Measured fluxes were compared with the literature to show the relative importance of the rural areas in the studied trace gases budget.

  11. Effect of sunlight shielding on leaf structure and amino acids ...

    African Journals Online (AJOL)

    zino

    2013-09-04

    Sep 4, 2013 ... acids concentration of light sensitive albino tea plant ... Key words: Camellia sinensis, leaf albinism, light intensity, photosynthetic pigments, amino acids, chloroplast. .... tructive reaction or photodamage which occurs in the.

  12. THE RISKS OF SUNLIGHTING CLASSROOMS. An appraisal method to assess the severity of discomfort due to sunlight penetration in classrooms. Site of study: Primary school classrooms in Constantine (ALGERIA

    Directory of Open Access Journals (Sweden)

    D SAFFIDINE-ROUAG

    2001-12-01

    Full Text Available The westerly orientations for a large number of primary school classrooms in Constantine involved a serious environmental problem provoked by uncontrolled sunlight. Under such circumstances the schoolchildren had no choice than keep sitting under incident sunlight while performing their various school tasks.  Evidence of the severity of discomfort experienced by those pupils was investigated using observational methods. The results allowed to reach substantial conclusions about the risks of sunlighting classrooms.

  13. Retrieving the vertical distribution of stratospheric OClO from Odin/OSIRIS limb-scattered sunlight measurements

    Directory of Open Access Journals (Sweden)

    P. Krecl

    2005-05-01

    Full Text Available The first vertical profiles of stratospheric OClO retrieved from Odin/OSIRIS limb-scattered sunlight radiances are presented. The retrieval method is based on a two-step approach, using differential optical absorption spectroscopy combined with the maximum a posteriori estimator. The details of the spectral window selection, spectral corrections and inversion technique are discussed. The results show that OClO can be detected inside the South polar vortex region between about 12 and 20 km altitude with a 2–5 km height resolution and an estimated retrieval error better than 60% at the peak. OClO concentrations are consistent with chemical transport model simulations and show the expected relation to the atmospheric conditions in the lower stratosphere in the austral spring 2002. This unique data set of OClO profiles is very promising to study the stratospheric chlorine activation in both polar regions.

  14. Retrieving the vertical distribution of stratospheric OClO from Odin/OSIRIS limb-scattered sunlight measurements

    Directory of Open Access Journals (Sweden)

    P. Krecl

    2006-01-01

    Full Text Available The first vertical profiles of stratospheric OClO retrieved from Odin/OSIRIS limb-scattered sunlight radiances are presented. The retrieval method is based on a two-step approach, using differential optical absorption spectroscopy combined with the maximum a posteriori estimator. The details of the spectral window selection, spectral corrections and inversion technique are discussed. The results show that OClO can be detected inside the South polar vortex region between about 14 and 22 km altitude with a 2–5 km height resolution and an estimated retrieval error better than 50% at the peak. OClO concentrations show the expected relation to the atmospheric conditions in the lower stratosphere in the austral spring 2002. This unique data set of OClO profiles is very promising to study the stratospheric chlorine activation in both polar regions.

  15. Co-exposure to sunlight enhances the toxicity of naturally weathered Deepwater Horizon oil to early lifestage red drum (Sciaenops ocellatus) and speckled seatrout (Cynoscion nebulosus).

    Science.gov (United States)

    Alloy, Matthew; Garner, Thomas Ross; Bridges, Kristin; Mansfield, Charles; Carney, Michael; Forth, Heather; Krasnec, Michelle; Lay, Claire; Takeshita, Ryan; Morris, Jeffrey; Bonnot, Shane; Oris, James; Roberts, Aaron

    2017-03-01

    The 2010 Deepwater Horizon oil spill resulted in the accidental release of millions of barrels of crude oil into the Gulf of Mexico. Photo-induced toxicity following co-exposure to ultraviolet (UV) radiation is 1 mechanism by which polycyclic aromatic hydrocarbons (PAHs) from oil spills may exert toxicity. Red drum and speckled seatrout are both important fishery resources in the Gulf of Mexico. They spawn near-shore and produce positively buoyant embryos that hatch into larvae in approximately 24 h. The goal of the present study was to determine whether exposure to UV as natural sunlight enhances the toxicity of crude oil to early lifestage red drum and speckled seatrout. Larval fish were exposed to several dilutions of high-energy water-accommodated fractions (HEWAFs) from 2 different oils collected in the field under chain of custody during the 2010 spill and 3 gradations of natural sunlight in a factorial design. Co-exposure to natural sunlight and oil significantly reduced larval survival compared with exposure to oil alone. Although both species were sensitive at PAH concentrations reported during the Deepwater Horizon spill, speckled seatrout demonstrated a greater sensitivity to photo-induced toxicity than red drum. These data demonstrate that even advanced weathering of slicks does not ameliorate the potential for photo-induced toxicity of oil to these species. Environ Toxicol Chem 2017;36:780-785. © 2016 SETAC. © 2016 SETAC.

  16. Hypovitaminosis D in patients undergoing kidney transplant: the importance of sunlight exposure.

    Science.gov (United States)

    Vilarta, Cristiane F; Unger, Marianna D; Dos Reis, Luciene M; Dominguez, Wagner V; David-Neto, Elias; Moysés, Rosa M; Titan, Silvia; Custodio, Melani R; Hernandez, Mariel J; Jorgetti, Vanda

    2017-07-01

    Recent studies have shown a high prevalence of hypovitaminosis D, defined as a serum 25-hydroxyvitamin D level less than 30 ng/ml, in both healthy populations and patients with chronic kidney disease. Patients undergoing kidney transplant are at an increased risk of skin cancer and are advised to avoid sunlight exposure. Therefore, these patients might share two major risk factors for hypovitaminosis D: chronic kidney disease and low sunlight exposure. This paper describes the prevalence and clinical characteristics of hypovitaminosis D among patients undergoing kidney transplant. We evaluated 25-hydroxyvitamin D serum levels in a representative sample of patients undergoing kidney transplant. We sought to determine the prevalence of hypovitaminosis D, compare these patients with a control group, and identify factors associated with hypovitaminosis D (e.g., sunlight exposure and dietary habits). Hypovitaminosis D was found in 79% of patients undergoing kidney transplant, and the major associated factor was low sunlight exposure. These patients had higher creatinine and intact parathyroid hormone serum levels, with 25-hydroxyvitamin D being inversely correlated with intact parathyroid hormone serum levels. Compared with the control group, patients undergoing kidney transplant presented a higher prevalence of 25-hydroxyvitamin D deficiency and lower serum calcium, phosphate and albumin but higher creatinine and intact parathyroid hormone levels. Our results confirmed the high prevalence of hypovitaminosis D in patients undergoing kidney transplant. Therapeutic strategies such as moderate sunlight exposure and vitamin D supplementation should be seriously considered for this population.

  17. Analysis of daylight performance of solar light pipes influenced by size and shape of sunlight captures

    Science.gov (United States)

    Wu, Yanpeng; Jin, Rendong; Zhang, Wenming; Liu, Li; Zou, Dachao

    2009-11-01

    Experimental investigations on three different sunlight captures with diameter 150mm, 212mm, 300mm were carried out under different conditions such as sunny conditions, cloudy conditions and overcast conditions and the two different size solar light pipes with diameter 360mm and 160mm under sunny conditions. The illuminance in the middle of the sunlight capture have relationship with its size, but not linear. To improve the efficiency of the solar light pipes, the structure and the performance of the sunlight capture must be enhanced. For example, University of Science and Technology Beijing Gymnasium, Beijing 2008 Olympic events of Judo and Taekwondo, 148 solar light pipes were installed with the diameter 530mm for each light pipe. Two sunlight captures with different shape were installed and tested. From the measuring results of the illuminance on the work plane of the gymnasium, the improvement sunlight captures have better effects with the size of augmenting and the machining of the internal surface at the same time, so that the refraction increased and the efficiency of solar light pipes improved. The better effects of supplementary lighting for the gymnasium have been achieved.

  18. Stainless steel in coastal seawater: sunlight counteracts biologically enhanced cathodic kinetics.

    Science.gov (United States)

    Eashwar, M; Lakshman Kumar, A; Sreedhar, G; Kennedy, J; Suresh Bapu, R H

    2014-09-01

    The influence of sunlight of varying intensity on the performance of UNS S30400 stainless steel (SS) was explored under conditions of natural biofilm development in coastal seawater. In a series of tests performed outdoors under an opaque roof, a range of shades were fashioned to impart varied amounts of diurnal light. These were an ambient level where the underwater illumination was ~ 5% of full sunlight, two intermediate ranges of lighting with ~ 2.5% and ~ 1% of the daylight, and a condition of full darkness. In comparison with the dark, increments of sunlight rendered the SS progressively less aggressive as cathodes in galvanic couples with UNS C70600 alloy. Likewise, welded SS with pre-initiated localized corrosion sites exhibited substantially lower rates of propagation with light. Thus, biofilms and sunlight affected cathodic kinetics in opposite ways. Surface analytical tests showed that the accumulation of manganese (Mn) within the biofilms was small relative to reports from waters of lower salinity. These results not only reveal that extremely low amounts of sunlight are adequate to offset the microbial effect, but also highlight the lack of convincing evidence for Mn cycling as a potent mechanism for enhanced cathodic kinetics in full-strength seawater.

  19. Calibrated cryo-cell UV-LA-ICPMS elemental concentrations from the NGRIP ice core reveal abrupt, sub-annual variability in dust across the GI-21.2 interstadial period

    Science.gov (United States)

    Della Lunga, Damiano; Müller, Wolfgang; Olander Rasmussen, Sune; Svensson, Anders; Vallelonga, Paul

    2017-05-01

    Several abrupt shifts from periods of extreme cold (Greenland stadials, GS) to relatively warmer conditions (Greenland interstadials, GI) called Dansgaard-Oeschger events are recorded in the Greenland ice cores. Using cryo-cell UV-laser-ablation inductively coupled-plasma mass spectrometry (UV-LA-ICPMS), we analysed a 2.85 m NGRIP ice core section (2691.50-2688.65 m depth, age interval 84.86-85.09 ka b2k, thus covering ˜ 230 years) across the transitions of GI-21.2, a short-lived interstadial prior to interstadial GI-21.1. GI-21.2 is a ˜ 100-year long period with δ18O values 3-4 ‰ higher than the following ˜ 200 years of stadial conditions (GS-21.2), which precede the major GI-21.1 warming. We report concentrations of major elements indicative of dust and/or sea salt (Na, Fe, Al, Ca, Mg) at a spatial resolution of ˜ 200 µm, while maintaining detection limits in the low-ppb range, thereby achieving sub-annual time resolution even in deep NGRIP ice. We present an improved external calibration and quantification procedure using a set of five ice standards made from aqueous (international) standard solutions. Our results show that element concentrations decrease drastically (more than 10-fold) at the warming onset of GI-21.2 at the scale of a single year, followed by relatively low concentrations characterizing the interstadial part before gradually reaching again typical stadial values.

  20. Effect of sunlight on the survival of pathogenic E. coli in freshwater and sea water

    DEFF Research Database (Denmark)

    Surendraraj, Alagarsamy; Farvin, Sabeena; Thampuran, N.

    2011-01-01

    An enteropathogenic group of E. coli are the emerging category of pathogen of public health significance. Several recent pathogenic E. coli outbreaks are associated with drinking water. Aquaculture, the fast emerging food production sector also poses a pathogenic EHEC outbreak risk, as it regularly...... uses cow dung, a reservoir of this organism. Hence, a experiment was set up to study the duration of survival of pathogenic E. coli under sunlight and darkness. Eight pathogenic E. coli isolates from clinical (EPEC, ETEC, EHEC, EAEC), veterinary (CTE3, CTE4) and environmental sources (ASHE3, Rao II......) were studied for their survival under sunlight and darkness in fresh water and seawater. Effect of direct sunlight on the viable but nonculturable (VBNC) state of cultures was also studied. The results of the study indicated a distinct pattern between freshwater system and seawater system. Pathogenic E...

  1. Optical modeling of sunlight by using partially coherent sources in organic solar cells.

    Science.gov (United States)

    Alaibakhsh, Hamzeh; Darvish, Ghafar

    2016-03-01

    We investigate the effects of coherent and partially coherent sources in optical modeling of organic solar cells. Two different organic solar cells are investigated: one without substrate and the other with a millimeter-sized glass substrate. The coherent light absorption is calculated with rigorous coupled-wave analysis. The result of this method is convolved with a distribution function to calculate the partially coherent light absorption. We propose a new formulation to accurately model sunlight as a set of partially coherent sources. In the structure with glass substrate, the accurate sunlight modeling results in the elimination of coherent effects in the thick substrate, but the coherency in other layers is not affected. Using partially coherent sources instead of coherent sources for simulations with sunlight results in a smoother absorption spectrum, but the change in the absorption efficiency is negligible.

  2. Photovoltaic solar concentrator

    Energy Technology Data Exchange (ETDEWEB)

    Nielson, Gregory N.; Gupta, Vipin P.; Okandan, Murat; Watts, Michael R.

    2016-03-15

    A photovoltaic solar concentrator is disclosed with one or more transverse-junction solar cells (also termed point contact solar cells) and a lens located above each solar cell to concentrate sunlight onto the solar cell to generate electricity. Piezoelectric actuators tilt or translate each lens to track the sun using a feedback-control circuit which senses the electricity generated by one or more of the solar cells. The piezoelectric actuators can be coupled through a displacement-multiplier linkage to provide an increased range of movement of each lens. Each lens in the solar concentrator can be supported on a frame (also termed a tilt plate) having three legs, with the movement of the legs being controlled by the piezoelectric actuators.

  3. Photovoltaic solar concentrator

    Energy Technology Data Exchange (ETDEWEB)

    Nielson, Gregory N.; Okandan, Murat; Resnick, Paul J.; Cruz-Campa, Jose Luis

    2012-12-11

    A photovoltaic solar concentrator is disclosed with one or more transverse-junction solar cells (also termed point contact solar cells) and a lens located above each solar cell to concentrate sunlight onto the solar cell to generate electricity. Piezoelectric actuators tilt or translate each lens to track the sun using a feedback-control circuit which senses the electricity generated by one or more of the solar cells. The piezoelectric actuators can be coupled through a displacement-multiplier linkage to provide an increased range of movement of each lens. Each lens in the solar concentrator can be supported on a frame (also termed a tilt plate) having three legs, with the movement of the legs being controlled by the piezoelectric actuators.

  4. Photovoltaic solar concentrator

    Science.gov (United States)

    Nielson, Gregory N.; Okandan, Murat; Resnick, Paul J.; Cruz-Campa, Jose Luis

    2012-12-11

    A photovoltaic solar concentrator is disclosed with one or more transverse-junction solar cells (also termed point contact solar cells) and a lens located above each solar cell to concentrate sunlight onto the solar cell to generate electricity. Piezoelectric actuators tilt or translate each lens to track the sun using a feedback-control circuit which senses the electricity generated by one or more of the solar cells. The piezoelectric actuators can be coupled through a displacement-multiplier linkage to provide an increased range of movement of each lens. Each lens in the solar concentrator can be supported on a frame (also termed a tilt plate) having three legs, with the movement of the legs being controlled by the piezoelectric actuators.

  5. De Novo Assembly and Comparative Transcriptome Analyses of Red and Green Morphs of Sweet Basil Grown in Full Sunlight

    National Research Council Canada - National Science Library

    Torre, Sara; Tattini, Massimiliano; Brunetti, Cecilia; Guidi, Lucia; Gori, Antonella; Marzano, Cristina; Landi, Marco; Sebastiani, Federico

    2016-01-01

    .... The development of a reference transcriptome for sweet basil, and the analysis of differentially expressed genes in acyanic and cyanic cultivars exposed to natural sunlight irradiance, has interest...

  6. Sunlight-stimulated phenylalanine ammonia-lyase (PAL activity and anthocyanin accumulation in exocarp of ‘Mahajanaka’ mango

    Directory of Open Access Journals (Sweden)

    Kobkiat Saengnil

    2011-11-01

    Full Text Available The activity of phenylalanine ammonia-lyase (PAL required for anthocyanin synthesis was stimulated by sunlight exposure resulting in the development of red colour in ‘Mahajanaka’ mango exocarp, which occurred only on the sunlight-exposed side of the fruit. The accumulation of anthocyanin was concurrent with the increase in PAL activity in the mature stage of the fruit. The exposed side of the fruit had higher PAL activity, endogenous sugar content, and anthocyanin accumulation than the unexposed side. It is concluded that sunlight increases red colour development of the mango exocarp by inducing PAL activity. Exposure to sunlight also enhances endogenous sugar accumulation in mango fruit.

  7. Annual changes of iron,manganese,zinc and copper concentrations in both types of citrus fruit%两结实类型柑橘果实铁锰锌铜含量的年周期变化

    Institute of Scientific and Technical Information of China (English)

    肖家欣; 彭抒昂

    2008-01-01

    Annual changes in concentrations of iron(Fe),manganese(Mn),zinc(Zn)and copper(Cu)were measured in whole fruits from parthenocarpic Kamei satsuma mandarin(Citrus unshiu)and self-pollinated Egan 1 tangerine(C.reticulata)trees. The results were showed as follows:(1)Zn and Cu concentrations in the ovary of Kamei were relatively high before flowering and at full bloom,and decreased after flowering,whereas those of Egan 1 decreased obviously and were relatively low at full bloom,thereafter significant increases were observed. There were no significant differences in changes of Fe and Mn concentrations in the ovaries(fruitlets)between the two cultivars,which presented similarly decreasing trends after flowering. (2)Fe,Mn,Zn and Cu concentrations were relatively high in whole fruits of both cultivars during young fruit development,and decreased remarkably during early fruit enlargement(drought spell),whereas increased dramatically at the middle stage of fruit enlargement,thereafter decreased gradually. Dynamics of micronutrients concentrations in developing fruit and their possible relation with fruits development is discussed herein.%对单性结实的龟井温州蜜柑和自花授粉结实的鄂柑1号柑橘果实的铁、锰、锌和铜含量的年周期变化进行了测定.结果表明:(1)龟井子房的锌和铜含量在花前至花期居较高,花后趋下降,而鄂柑1号对应值在花期出现明显下降并居较低,花后却有一明显上升;两品种子房(幼果)的铁和锰含量变化却无明显差异,花后呈类似的下降趋势.(2)幼果阶段的果实铁、锰、锌和铜含量均居较高,在果实膨大初期(干旱期)均出现一明显下降,而在果实膨大中期却出现显著上升,之后又趋下降.本文还对果实发育中的微量元素含量动态及其与果实发育之间的关系进行了讨论.

  8. Railway suicide attempts are associated with amount of sunlight in recent days.

    Science.gov (United States)

    Kadotani, Hiroshi; Nagai, Yumiko; Sozu, Takashi

    2014-01-01

    To assess the relationship between hours of sunlight and railway suicide attempts, 3-7 days before these attempts. All railway suicide attempts causing railway suspensions or delays of 30 min or more between 2002 and 2006. We used a linear probability model to assess this relationship. This study was conducted at Tokyo, Kanagawa, and Osaka prefectures in Japan. Data were collected from the railway delay incident database of the Japanese Railway Technical Research Institute and public weather database of the Japan Meteorological Agency. About 971 railway suicides attempts occurred between 2002 and 2006 in Tokyo, Kanagawa, and Osaka. Less sunlight in the 7 days leading up to the railway suicide attempts was associated with a higher proportion of attempts (p=0.0243). Sunlight over the 3 days before an attempt had a similar trend (p=0.0888). No difference was found in sunlight hours between the days with (median: 5.6 [IQR: 1.1-8.8]) and without (median: 5.7 [IQR: 1.0-8.9]) railway suicide attempts in the evening. Finally, there was no apparent correlation between the railway suicide attempts and the monthly average sunlight hours of the attempted month or those of a month before. Railway suicides were not the main suicidal methods in Japan, We observed an increased proportion of railway suicide attempts after several days without sunlight. Light exposure (blue light or bright white light) in trains may be useful in reducing railway suicides, especially when consecutive days without sunshine are forecasted. © 2013 Elsevier B.V. All rights reserved.

  9. Using metal nanostructures to form hydrocarbons from carbon dioxide, water and sunlight

    Science.gov (United States)

    Wang, Cong; Shen, Mengyan; Huo, Haibin; Ren, Haizhou; Johnson, Michael

    2011-12-01

    Based on experimental results, we propose a mechanism that allows the use of metal nanostructures to synthesize hydrocarbons and carbohydrates from carbon dioxide, water and sunlight. When sunlight impinges on cobalt nanostructures in a glass chamber, its intensity is greatly enhanced around the tips of the nanostructures through surface plasmon excitations focusing effect, and it then photodissociates the water and carbon dioxide molecules through enhanced photon absorptions of ions around the tips of the nanostructures. The photodissociated molecules in excited states remain on the cobalt nanostructure surfaces and various hydrocarbons and carbohydrates then will be formed around the surfaces at temperatures much lower than 100 oC.

  10. Socioeconomic status, sunlight exposure, and risk of malignant melanoma: the Western Canada Melanoma Study.

    Science.gov (United States)

    Gallagher, R P; Elwood, J M; Threlfall, W J; Spinelli, J J; Fincham, S; Hill, G B

    1987-10-01

    In a study of 261 male melanoma patients and age-and sex-matched controls, a strong positive univariate association between socioeconomic status, as determined by usual occupation, and risk of melanoma was detected. This association, however, was substantially explained by host constitutional factors and occupational, recreational, and vacation sunlight exposure. The study demonstrated an increased risk of melanoma in draftsmen and surveyors and a reduced risk of melanoma in construction workers and individuals employed in the finance, insurance, and real estate industry even after control for the effect of host factors and sunlight exposure.

  11. Test technology on CCD anti-sunlight jamming based on complex circumstance

    Science.gov (United States)

    Shi, Sheng-bing; Chen, Zhen-xing; Han, Fu-li

    2016-09-01

    Visible-light reconnaissance device based on CCD is applied to all kinds of weapons, CCD cannot work because of saturation when it faces intense light. Sun is intense light source in nature and assignably influences CCD performance. In this paper, aim is appraising CCD anti-sunlight ability, object reflection characteristic test system is designed, based on typical background reflection characteristic including grant, sand and so on, complex circumstance is formulated and test project is optimized with orthogonal design method, problem that is without test technology on CCD anti-sunlight jamming is solved.

  12. The Seasonality of Tuberculosis, Sunlight, Vitamin D, and Household Crowding

    OpenAIRE

    2014-01-01

    Background.  Unlike other respiratory infections, tuberculosis diagnoses increase in summer. We performed an ecological analysis of this paradoxical seasonality in a Peruvian shantytown over 4 years. Methods.  Tuberculosis symptom-onset and diagnosis dates were recorded for 852 patients. Their tuberculosis-exposed cohabitants were tested for tuberculosis infection with the tuberculin skin test (n = 1389) and QuantiFERON assay (n = 576) and vitamin D concentrations (n = 195) quantified from ra...

  13. Uranium industry annual 1998

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-04-22

    The Uranium Industry Annual 1998 (UIA 1998) provides current statistical data on the US uranium industry`s activities relating to uranium raw materials and uranium marketing. It contains data for the period 1989 through 2008 as collected on the Form EIA-858, ``Uranium Industry Annual Survey.`` Data provides a comprehensive statistical characterization of the industry`s activities for the survey year and also include some information about industry`s plans and commitments for the near-term future. Data on uranium raw materials activities for 1989 through 1998, including exploration activities and expenditures, EIA-estimated reserves, mine production of uranium, production of uranium concentrate, and industry employment, are presented in Chapter 1. Data on uranium marketing activities for 1994 through 2008, including purchases of uranium and enrichment services, enrichment feed deliveries, uranium fuel assemblies, filled and unfilled market requirements, and uranium inventories, are shown in Chapter 2. The methodology used in the 1998 survey, including data edit and analysis, is described in Appendix A. The methodologies for estimation of resources and reserves are described in Appendix B. A list of respondents to the ``Uranium Industry Annual Survey`` is provided in Appendix C. The Form EIA-858 ``Uranium Industry Annual Survey`` is shown in Appendix D. For the readers convenience, metric versions of selected tables from Chapters 1 and 2 are presented in Appendix E along with the standard conversion factors used. A glossary of technical terms is at the end of the report. 24 figs., 56 tabs.

  14. Luminescent Solar Concentrators – a low cost photovoltaics alternative

    Directory of Open Access Journals (Sweden)

    van Sark W.G.J.H.M.

    2012-10-01

    Full Text Available Luminescent solar concentrators (LSCs are being developed as a potentially low cost-per-Wp photovoltaic device, suited for applications especially in the built environment. LSCs generally consist of transparent polymer sheets doped with luminescent species, either organic dye molecules or semiconductor nanocrystals. Direct and diffuse incident sunlight is absorbed by the luminescent species and emitted at redshifted wavelengths with high quantum efficiency. Optimum design ensures that a large fraction of emitted light is trapped in the sheet, which travels to the edges where it can be collected by one or more mono- or bifacial solar cells, with minimum losses due to absorption in the sheet and re-absorption by the luminescent species. Today’s record efficieny is 7%, however, 10-15% is within reach. Optimized luminescent solar concentrators potentially offer lower cost per unit of power compared to conventional solar cells. Moreover, LSCs have an increased conversion efficiency for overcast and cloudy sky conditions, having a large fraction of diffuse irradiation, which is blueshifted compared to clear sky conditions. As diffuse irradiation conditions are omnipresent throughout mid- and northern-European countries, annual performance of LSCs is expected to be better in terms of kWh/Wp compared to conventional PV.

  15. Mesoporous film of WO3-the "sunlight" assisted decomposition of surfactant in wastewater for voltammetric determination of Pb

    Science.gov (United States)

    Krasnodębska-Ostręga, Beata; Bielecka, Agnieszka; Biaduń, Ewa; Miecznikowski, Krzysztof

    2016-12-01

    In this paper we present the application of "sunlight" assisted digestion in the presence of WO3 to the decomposition of dissolved organic matter, using the anionic surfactant sodium dodecyl sulfate (SDS) and the nonionic surfactant (1,1,3,3-tetramethylbutyl)phenyl-polyethylene glycol (Triton™X-114) in natural water samples, prior to the determination of traces residues of lead by stripping voltammetry methods. The results of the study showed firstly that the preparation of reproducible WO3 layers characterized by high mechanical and chemical resistance was possible, and secondly that it was also possible to obtain a high efficiency of decomposition, equal in efficiency to that of the reference method, which was the hydrogen peroxide oxidation assisted by UV, with evaporation nearly to dryness. The developed procedure is suggested to be a no-reagents method for the decomposition of added SDS, leading to 100% recovery of added Pb (II). The anodic stripping voltammetric curves recorded in solution after 4 h irradiation with UV assisted by WO3 were repeatable and increased linearly with standard additions, but the data finally obtained were incorrect. The curves recorded in solution after "sunlight" assisted digestion in the presence of WO3 were repeatable, and increased linearly with an increasing of concentration of standard additions (100% recovery of Pb). In the case of a nonionic surfactant, the decomposition time is at least 6 h. The advantage of the proposed method is the fact that the digestion process does not need the addition of any chemicals for the complete decomposition of organic matter.

  16. HISTORY OF SUNLIGHT EXPOSURE IS A RISK FACTOR FOR AGE-RELATED MACULAR DEGENERATION

    NARCIS (Netherlands)

    Schick, T.; Ersoy, L.; Lechanteur, Y.T.; Saksens, N.T.; Hoyng, C.B.; Hollander, A.I. den; Kirchhof, B.; Fauser, S.

    2016-01-01

    PURPOSE: To evaluate effects of current and past sunlight exposure and iris color on early and late age-related macular degeneration (AMD). METHODS: Of 3,701 individuals from the EUGENDA database, 752 (20.3%) showed early AMD, 1,179 (31.9%) late AMD, and 1,770 (47.8%) were controls. Information abou

  17. Commonly recommended daily intake of vitamin D is not sufficient if sunlight exposure is limited

    DEFF Research Database (Denmark)

    Glerup, H; Mikkelsen, K; Poulsen, L

    2000-01-01

    intake analysis to estimate the oral intake of vitamin D necessary to keep a normal vitamin D status in sunlight-deprived individuals. DESIGN: Cross-sectional study amongst randomly selected Moslem women of Arab origin living in Denmark. Age-matched Danish women were included as controls. To control...

  18. [The Impact of Sunlight Exposure on the Health of Older Adults].

    Science.gov (United States)

    Lin, Tzu-Chia; Liao, Yen-Chi

    2016-08-01

    Appropriate exposure to sunlight not only contributes to the production of vitamin D, which has been associated with enhanced bone health, mood, and cognitive functions, but also regulates the secretion of melatonin, which has been associated with the mediation of circadian rhythms, improved sleep quality, and optimized physical and social activity in the elderly. However, damage to the skin, eyes, and immune system has also been widely associated with long-term exposure to sunlight. Several studies have shown that many elderly, especially those that reside in institutions, do not receive sufficient sunlight exposure. Institutionalized elderly tend to participate in indoor activities and spend significant periods of time alone and asleep in front of the television. Furthermore, factors such as poor health, environmental design, indoor/outdoor preference, and activity design may impact the access of institutionalized elderly to sunlight more than their non-institutionalized peers. Therefore, we suggest that in addition to obtaining sufficient levels of vitamin D from their diet and from supplements, the elderly should perform outdoor activities for 20-30 minutes a day for five days each week. Furthermore, we suggest that the environment of the care facility should be made be more accessible and that some activities should be held outdoors.

  19. Preventive role of lens antioxidant defense mechanism against riboflavin-mediated sunlight damaging of lens crystallins.

    Science.gov (United States)

    Anbaraki, Afrooz; Khoshaman, Kazem; Ghasemi, Younes; Yousefi, Reza

    2016-10-01

    The main components of sunlight reaching the eye lens are UVA and visible light exerting their photo-damaging effects indirectly by the aid of endogenous photosensitizer molecules such as riboflavin (RF). In this study, lens proteins solutions were incubated with RF and exposed to the sunlight. Then, gel mobility shift analysis and different spectroscopic assessments were applied to examine the structural damaging effects of solar radiation on these proteins. Exposure of lens proteins to direct sunlight, in the presence of RF, leads to marked structural crosslinking, oligomerization and proteolytic instability. These structural damages were also accompanied with reduction in the emission fluorescence of Trp and Tyr and appearance of a new absorption peak between 300 and 400nm which can be related to formation of new chromophores. Also, photo-oxidation of lens crystallins increases their oligomeric size distribution as examined by dynamic light scattering analysis. The above mentioned structural insults, as potential sources of sunlight-induced senile cataract and blindness, were significantly attenuated in the presence of ascorbic acid and glutathione which are two important components of lens antioxidant defense system. Therefore, the powerful antioxidant defense mechanism of eye lens is an important barrier against molecular photo-damaging effects of solar radiations during the life span. Copyright © 2016 Elsevier B.V. All rights reserved.

  20. The relationships among birth season, sunlight exposure during infancy, and allergic disease.

    Science.gov (United States)

    Hwang, Jung Min; Oh, Se Hyun; Shin, Mee Yong

    2016-05-01

    The recent increase in the prevalence of allergic diseases is hypothetically attributed to immune dysregulation in turn caused by a reduction in exposure to sunlight. We explored relationships between birth season, sunlight exposure, exercise duration, and an allergic disease. We performed a questionnaire-based survey on allergic diseases among elementary school students. Birth time was categorized according to the season (summer and winter). The prevalence of atopic dermatitis (AD) "symptoms ever" was higher in the children born in winter than in those born in summer (adjusted odds ratio [aOR], 1.24; 95% confidence interval [CI], 1.03-1.49; P=0.024). Birth in winter was associated with an increase in the "symptoms in the past 12 months" prevalence of food allergy (FA) (aOR, 1.56; 95% CI, 1.09-2.24; P=0.015). The lifetime prevalence of allergic diseases except FA was higher in the children whose parents considered their sunlight exposure prior to 24 months of ageas inadequate than those who considered their exposure as adequate ("diagnosis ever" asthma: aOR, 1.4; 95% CI, 1.17-1.67; Psunlight exposure nor exercise duration was associated with the prevalence of an allergic disease. Birth in winter may be associated with development of AD and FA. Inadequate sunlight exposure before the age of 24 months might possibly increase the risks of development of asthma, AR, and AD.

  1. HISTORY OF SUNLIGHT EXPOSURE IS A RISK FACTOR FOR AGE-RELATED MACULAR DEGENERATION

    NARCIS (Netherlands)

    Schick, T.; Ersoy, L.; Lechanteur, Y.T.; Saksens, N.T.; Hoyng, C.B.; Hollander, A.I. den; Kirchhof, B.; Fauser, S.

    2016-01-01

    PURPOSE: To evaluate effects of current and past sunlight exposure and iris color on early and late age-related macular degeneration (AMD). METHODS: Of 3,701 individuals from the EUGENDA database, 752 (20.3%) showed early AMD, 1,179 (31.9%) late AMD, and 1,770 (47.8%) were controls. Information abou

  2. Degradation of benzotriazole and benzothiazole in treatment wetlands and by artificial sunlight.

    Science.gov (United States)

    Felis, Ewa; Sochacki, Adam; Magiera, Sylwia

    2016-11-01

    Laboratory-scale experiments were performed using unsaturated subsurface-flow treatment wetlands and artificial sunlight (with and without TiO2) to study the efficiency of benzotriazole and benzothiazole removal and possible integration of these treatment methods. Transformation products in the effluent from the treatment wetlands and the artificial sunlight reactor were identified by high performance liquid chromatography coupled with tandem mass spectrometry. The removal of benzothiazole in the vegetated treatment wetlands was 99.7%, whereas the removal of benzotriazole was 82.8%. The vegetation positively affected only the removal of benzothiazole. The major transformation products in the effluents from the treatment wetlands were methylated and hydroxylated derivatives of benzotriazole, and hydroxylated derivatives of benzothiazole. Hydroxylation was found to be the main process governing the transformation pathway for both compounds in the artificial sunlight experiment (with and without TiO2). Benzotriazole was not found to be susceptible to photodegradation in the absence of TiO2. The integration of the sunlight-induced processes (with TiO2) with subsurface-flow treatment wetlands caused further elimination of the compounds (42% for benzotriazole and 58% for benzothiazole). This was especially significant for the elimination of benzotriazole, because the removal of this compound was 96% in the coupled processes. Copyright © 2016 Elsevier Ltd. All rights reserved.

  3. Inactivation of enteropathogenic E. coli by solar disinfection (SODIS) under simulated sunlight conditions

    Energy Technology Data Exchange (ETDEWEB)

    Ubomba-Jaswa, E; Boyle, M A R; McGuigan, K G [Department of Physiology and Medical Physics, Royal College of Surgeons in Ireland, Dublin 2 (Ireland)], E-mail: kmcguigan@rcsi.ie

    2008-02-01

    Solar Disinfection (SODIS) is a low cost water treatment method currently used in communities that do not have year round access to safe water. However, there is still reluctance in widespread adoption of this treatment method due to a number of limitations. An important limitation is the lack of SODIS inactivation studies on some waterborne pathogens in the developing world. SODIS inactivation of enteropathogenic E. coli (EPEC), a major cause of infantile diarrhoea is reported for the first time under simulated sunlight conditions and following a natural temperature profile. EPEC was exposed to simulated sunlight (885Wm{sup -2}) for periods up to a cumulative time of 4 hours. Inactivation was determined by a log reduction in growth of the organisms. The temperature (deg. C) of the water was taken at every time point. After 4 hours exposure EPEC was completely inactivated (7 log reduction) by SODIS. Imposing a realistic water temperature profile (min-max) concomitant with irradiation produces a greater kill of EPEC. Maintaining simulated sunlight experiments at a high fixed temperature may result in over-estimation of inactivation. Following a natural water temperature profile will result in more reliable inactivation comparable with those that might be obtained under natural sunlight conditions.

  4. Inactivation of enteropathogenic E. coli by solar disinfection (SODIS) under simulated sunlight conditions

    Science.gov (United States)

    Ubomba-Jaswa, E.; Boyle, M. A. R.; McGuigan, K. G.

    2008-02-01

    Solar Disinfection (SODIS) is a low cost water treatment method currently used in communities that do not have year round access to safe water. However, there is still reluctance in widespread adoption of this treatment method due to a number of limitations. An important limitation is the lack of SODIS inactivation studies on some waterborne pathogens in the developing world. SODIS inactivation of enteropathogenic E. coli (EPEC), a major cause of infantile diarrhoea is reported for the first time under simulated sunlight conditions and following a natural temperature profile. EPEC was exposed to simulated sunlight (885Wm-2) for periods up to a cumulative time of 4 hours. Inactivation was determined by a log reduction in growth of the organisms. The temperature (°C) of the water was taken at every time point. After 4 hours exposure EPEC was completely inactivated (7 log reduction) by SODIS. Imposing a realistic water temperature profile (min-max) concomitant with irradiation produces a greater kill of EPEC. Maintaining simulated sunlight experiments at a high fixed temperature may result in over --estimation of inactivation. Following a natural water temperature profile will result in more reliable inactivation comparable with those that might be obtained under natural sunlight conditions.

  5. 40 CFR 795.70 - Indirect photolysis screening test: Sunlight photolysis in waters containing dissolved humic...

    Science.gov (United States)

    2010-07-01

    ... mobile phase is 2 percent acetic acid, 50 percent acetonitrile and 48 percent water (2 mL/min flow rate... of sunlight actinometers.” Environmental Science and Technology, 6:815. (1982). (6) Haag H.R., Hoigne... Science and Technology, 11:359. (1977). (20) Zepp, R.G., Wolfe N.L., Baughman G.L., Hollis R.C....

  6. IS THERE A LINK BETWEEN SUNLIGHT EXPOSURE AND 25-HYDROXYVITAMIN D DEFICIENCY IN CHRONIC KIDNEY DISEASE PATIENTS?

    Directory of Open Access Journals (Sweden)

    Angela Yee-Moon Wang

    2012-06-01

    In conclusion, our study confirmed an extremely high prevalence of vitamin D deficiency and an important association between outdoor sunlight exposure and 25(OHD deficiency in Chinese stage 3-5 CKD patients. Further study is needed to determine whether increasing daily outdoor sunlight exposure may represent a cost-free treatment for correcting nutritional 25(OHD deficiency in the CKD population.

  7. Photosensitized rose Bengal-induced phototoxicity on human melanoma cell line under natural sunlight exposure.

    Science.gov (United States)

    Srivastav, Ajeet K; Mujtaba, Syed Faiz; Dwivedi, Ashish; Amar, Saroj K; Goyal, Shruti; Verma, Ankit; Kushwaha, Hari N; Chaturvedi, Rajnish K; Ray, Ratan Singh

    2016-03-01

    Rose Bengal (RB) is an anionic water-soluble xanthene dye, which used for many years to assess eye cornea and conjunctiva damage. RB showed strong absorption maxima (λmax) under visible light followed by UV-B and UV-A. RB under sunlight exposure showed a time-dependent photodegradation. Our results show that photosensitized RB generates (1)O2 via Type-II photodynamic pathway and induced DNA damage under sunlight/UV-R exposure. 2'dGuO degradation, micronuclei formation, and single- and double-strand breakage were the outcome of photogenotoxicity caused by RB. Quenching studies with NaN3 advocate the involvement of (1)O2 in RB photogenotoxicity. RB induced linoleic acid photoperoxidation, which was parallel to (1)O2-mediated DNA damage. Oxidative stress in A375 cell line (human melanoma cell line) was detected through DCF-DA assay. Photosensitized RB decreased maximum cellular viability under sunlight followed by UV-B and UV-A exposures. Apoptosis was detected as a pattern of cell death through the increased of caspase-3 activity, decreased mitochondrial membrane potential, and PS translocation through inner to outer plasma membrane. Increased cytosolic levels of Bax also advocate the apoptotic cell death. We propose a p53-mediated apoptosis via increased expression of Bax gene and protein. Thus, the exact mechanism behind RB phototoxicity was the involvement of (1)O2, which induced oxidative stress-mediated DNA and membrane damage, finally apoptotic cell death under natural sunlight exposure. The study suggests that after the use of RB, sunlight exposure may avoid to prevent from its harmful effects. Copyright © 2015. Published by Elsevier B.V.

  8. Effect of Sunlight Radiation on the Growth and Chemical Constituents of Salvia plebeia R.Br.

    Directory of Open Access Journals (Sweden)

    Hyun-Jae Jang

    2017-08-01

    Full Text Available This study investigated the chemical composition changes of Salvia plebeia R.Br. cultivated under different light sources, including florescent light and sunlight. The plants were exposed to fluorescent light for four months and sunlight and then examined for the next 5–7 months. Plants were harvested monthly during the seven months, and we examined whether the difference in light source affected the phenolic and flavonoid contents and antioxidant activity. A simple and reliable HPLC method using a PAH C18 column was applied for the quantitative analysis of two triterpenoids from the S. plebeia groups. Oleanolic acid (OA and ursolic acid (UA showed good linearity (R2 > 0.9999 within the test ranges (0.005–0.05 mg/mL, and the average percentage recoveries of the OA and UA were 95.1–104.8% and 97.2–107.1%, respectively. The intra- and inter-day relative standard deviations (RSDs were less than 2.0%. After exposure to sunlight, the phenolic contents, including rosmarinic acid, showed a reduced tendency, whereas the flavonoid contents, including homoplantaginin and luteolin 7-glucoside, were increased. The content of the triterpenoids also showed an increased tendency under sunlight irradiation, but the variance was not larger than those of the phenolic and flavonoid contents. Among experimental groups, the group harvested at six months, having been exposed to sunlight for two months, showed the most potent antioxidant activity. Therefore, these results showed that the chemical composition and antioxidant activities of S. plebeia R.Br. was affected from environmental culture conditions, such as light source. Our studies will be useful for the development of functional materials using S. plebeia R.Br.

  9. Effect of Sunlight Radiation on the Growth and Chemical Constituents of Salvia plebeia R.Br.

    Science.gov (United States)

    Jang, Hyun-Jae; Lee, Seung-Jae; Kim, Cha Young; Hwang, Joo Tae; Choi, Jung Ho; Park, Jee Hun; Lee, Seung Woong; Rho, Mun-Chual

    2017-08-01

    This study investigated the chemical composition changes of Salvia plebeia R.Br. cultivated under different light sources, including florescent light and sunlight. The plants were exposed to fluorescent light for four months and sunlight and then examined for the next 5-7 months. Plants were harvested monthly during the seven months, and we examined whether the difference in light source affected the phenolic and flavonoid contents and antioxidant activity. A simple and reliable HPLC method using a PAH C18 column was applied for the quantitative analysis of two triterpenoids from the S. plebeia groups. Oleanolic acid (OA) and ursolic acid (UA) showed good linearity (R² > 0.9999) within the test ranges (0.005-0.05 mg/mL), and the average percentage recoveries of the OA and UA were 95.1-104.8% and 97.2-107.1%, respectively. The intra- and inter-day relative standard deviations (RSDs) were less than 2.0%. After exposure to sunlight, the phenolic contents, including rosmarinic acid, showed a reduced tendency, whereas the flavonoid contents, including homoplantaginin and luteolin 7-glucoside, were increased. The content of the triterpenoids also showed an increased tendency under sunlight irradiation, but the variance was not larger than those of the phenolic and flavonoid contents. Among experimental groups, the group harvested at six months, having been exposed to sunlight for two months, showed the most potent antioxidant activity. Therefore, these results showed that the chemical composition and antioxidant activities of S. plebeia R.Br. was affected from environmental culture conditions, such as light source. Our studies will be useful for the development of functional materials using S. plebeia R.Br.

  10. Effect of sunlight exposure on cognitive function among depressed and non-depressed participants: a REGARDS cross-sectional study.

    Science.gov (United States)

    Kent, Shia T; McClure, Leslie A; Crosson, William L; Arnett, Donna K; Wadley, Virginia G; Sathiakumar, Nalini

    2009-07-28

    Possible physiological causes for the effect of sunlight on mood are through the suprachiasmatic nuclei and evidenced by serotonin and melatonin regulation and its associations with depression. Cognitive function involved in these same pathways may potentially be affected by sunlight exposure. We evaluated whether the amount of sunlight exposure (i.e. insolation) affects cognitive function and examined the effect of season on this relationship. We obtained insolation data for residential regions of 16,800 participants from a national cohort study of blacks and whites, aged 45+. Cognitive impairment was assessed using a validated six-item screener questionnaire and depression status was assessed using the Center for Epidemiologic Studies Depression Scale. Logistic regression was used to find whether same-day or two-week average sunlight exposure was related to cognitive function and whether this relationship differed by depression status. Among depressed participants, a dose-response relationship was found between sunlight exposure and cognitive function, with lower levels of sunlight associated with impaired cognitive status (odds ratio = 2.58; 95% CI 1.43-6.69). While both season and sunlight were correlated with cognitive function, a significant relation remained between each of them and cognitive impairment after controlling for their joint effects. The study found an association between decreased exposure to sunlight and increased probability of cognitive impairment using a novel data source. We are the first to examine the effects of two-week exposure to sunlight on cognition, as well as the first to look at sunlight's effects on cognition in a large cohort study.

  11. Sunlight exposure during leisure activities and risk of prostate cancer in Montréal, Canada, 2005-2009.

    Science.gov (United States)

    Yu, Jennifer; Lavoué, Jérôme; Parent, Marie-Élise

    2014-07-28

    Prostate cancer (PCa) is the leading cause of cancer in men in many developed countries, but no modifiable risk factors have been identified. A handful of analytical studies have suggested a possible etiological role for sunlight exposure. We report here on the association between leisure-time sunlight exposure during adulthood and PCa risk in the context of a population-based case-control study. In all, 1,904 PCa cases were ascertained across Montreal French hospitals between 2005 and 2009. Concurrently, 1,962 population controls, frequency matched to cases by age (±5 years), were selected from the electoral list for French-speakers in Greater Montreal. Interviews elicited the frequency of engagement in any leisure activity during adulthood. This was used to derive cumulative sunlight exposure indices: a cumulative number of leisure activities events entailing sunlight exposure and a cumulative duration of sunlight exposure during leisure activities. Unconditional logistic regression was conducted to yield odds ratios (OR) and 95% confidence intervals (CI) for estimating the association between sunlight exposure indices and PCa risk, adjusting for age, ancestry, family history of PCa, PCa screening, education, solar protection, body mass index and physical activity. Compared with men in the upper quartile category for the number of sunlight exposure events, men never exposed during leisure time had an OR of 1.32 (95% CI: 0.82-2.14). ORs were 1.11, 0.91 and 1.00 for the first to the third quartiles of exposure, respectively. Similar results were observed for cumulative duration of exposure to sunlight, and by PCa aggressiveness. These findings provide little evidence of an association between sunlight exposure during leisure-time and PCa risk. Men with no sunlight exposure appeared at somewhat higher risks but none of the estimates achieved statistical significance.

  12. Staphylococcus aureus Strain Newman Photoinactivation and Cellular Response to Sunlight Exposure.

    Science.gov (United States)

    McClary, Jill S; Sassoubre, Lauren M; Boehm, Alexandria B

    2017-09-01

    Sunlight influences microbial water quality of surface waters. Previous studies have investigated photoinactivation mechanisms and cellular photostress responses of fecal indicator bacteria (FIB), including Escherichia coli and enterococci, but further work is needed to characterize photostress responses of bacterial pathogens. Here we investigate the photoinactivation of Staphylococcus aureus (strain Newman), a pigmented, waterborne pathogen of emerging concern. We measured photodecay using standard culture-based assays and cellular membrane integrity and investigated photostress response by measuring the relative number of mRNA transcripts of select oxidative stress, DNA repair, and metabolism genes. Photoinactivation experiments were performed in both oxic and anoxic systems to further investigate the role of oxygen-mediated and non-oxygen-mediated photoinactivation mechanisms. S. aureus lost culturability much faster in oxic systems than in anoxic systems, indicating an important role for oxygen in photodecay mechanisms. S. aureus cell membranes were damaged by sunlight exposure in anoxic systems but not in oxic systems, as measured by cell membrane permeability to propidium iodide. After sunlight exposure, S. aureus increased expression of a gene coding for methionine sulfoxide reductase after 12 h of sunlight exposure in the oxic system and after 6 h of sunlight exposure in the anoxic system, suggesting that methionine sulfoxide reductase is an important enzyme for defense against both oxygen-dependent and oxygen-independent photostresses. This research highlights the importance of oxygen in bacterial photoinactivation in environmentally relevant systems and the complexity of the bacterial photostress response with respect to cell structure and transcriptional regulation.IMPORTANCEStaphylococcus aureus is a pathogenic bacterium that causes gastrointestinal, respiratory, and skin infections. In severe cases, S. aureus infection can lead to life

  13. Secondary concentrators for parabolic dish solar thermal power systems

    Science.gov (United States)

    Jaffe, L. D.; Poon, P. T.

    1981-01-01

    A variety of different concepts are currently being studied with the objective to lower the cost of parabolic mirrors and to provide alternatives. One of the considered approaches involves the use of compound concentrators. A compound solar concentrator is a concentrator in which the sunlight is reflected or refracted more than once. It consists of a primary mirror or lens, whose aperture determines the amount of sunlight gathered, and a smaller secondary mirror or lens. Additional small optical elements may also be incorporated. The possibilities and problems regarding a use of compound concentrators in parabolic dish systems are discussed. Attention is given to concentrating secondary lenses, secondary imaging and concentrating mirrors, conical secondary mirrors, compound elliptic secondary concentrating mirrors, and hyperbolic trumpet secondary concentrating mirrors.

  14. Uranium industry annual 1994

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-07-05

    The Uranium Industry Annual 1994 (UIA 1994) provides current statistical data on the US uranium industry`s activities relating to uranium raw materials and uranium marketing during that survey year. The UIA 1994 is prepared for use by the Congress, Federal and State agencies, the uranium and nuclear electric utility industries, and the public. It contains data for the 10-year period 1985 through 1994 as collected on the Form EIA-858, ``Uranium Industry Annual Survey.`` Data collected on the ``Uranium Industry Annual Survey`` (UIAS) provide a comprehensive statistical characterization of the industry`s activities for the survey year and also include some information about industry`s plans and commitments for the near-term future. Where aggregate data are presented in the UIA 1994, care has been taken to protect the confidentiality of company-specific information while still conveying accurate and complete statistical data. A feature article, ``Comparison of Uranium Mill Tailings Reclamation in the United States and Canada,`` is included in the UIA 1994. Data on uranium raw materials activities including exploration activities and expenditures, EIA-estimated resources and reserves, mine production of uranium, production of uranium concentrate, and industry employment are presented in Chapter 1. Data on uranium marketing activities, including purchases of uranium and enrichment services, and uranium inventories, enrichment feed deliveries (actual and projected), and unfilled market requirements are shown in Chapter 2.

  15. Production of Bio-Energy from Pig Manure: A Focus on the Dynamics Change of Four Parameters under Sunlight-Dark Conditions.

    Directory of Open Access Journals (Sweden)

    Dongxue Yin

    Full Text Available This study investigated the effect of sunlight-dark conditions on volatile fatty acids (VFAs, total ammonium nitrogen (TAN, total alkalinity (TA and pH during pig manure (PM digestion and then the subsequent influence on biogas yield of PM. PM1 and PM2 were performed in a transparent reactor and a non-transparent reactor, respectively. Two sets of experiments were conducted with a temperature of 35.0±2.0 °C and a total solid concentration of 8.0% to the digestion material. The dynamic change of the four parameters in response to sunlight-dark conditions resulted in variations of the physiological properties in the digester and affected the cumulative biogas production (CBP. PM1 obtained higher CBP (15020.0 mL with a more stable pH and a lower TAN concentration (1414.5 mg/L compared to PM2 (2675.0 mL and 1670.0 mg/L, respectively. The direct path coefficients and indirect path coefficients between the four parameters and CBP were also analyzed.

  16. Production of Bio-Energy from Pig Manure: A Focus on the Dynamics Change of Four Parameters under Sunlight-Dark Conditions

    Science.gov (United States)

    Yin, Dongxue; Liu, Wei; Zhai, Ningning; Feng, Yongzhong; Yang, Gaihe; Wang, Xiaojiao; Han, Xinhui

    2015-01-01

    This study investigated the effect of sunlight-dark conditions on volatile fatty acids (VFAs), total ammonium nitrogen (TAN), total alkalinity (TA) and pH during pig manure (PM) digestion and then the subsequent influence on biogas yield of PM. PM1 and PM2 were performed in a transparent reactor and a non-transparent reactor, respectively. Two sets of experiments were conducted with a temperature of 35.0±2.0 °C and a total solid concentration of 8.0% to the digestion material. The dynamic change of the four parameters in response to sunlight-dark conditions resulted in variations of the physiological properties in the digester and affected the cumulative biogas production (CBP). PM1 obtained higher CBP (15020.0 mL) with a more stable pH and a lower TAN concentration (1414.5 mg/L) compared to PM2 (2675.0 mL and 1670.0 mg/L, respectively). The direct path coefficients and indirect path coefficients between the four parameters and CBP were also analyzed. PMID:25970266

  17. Photodegradation of 2,4-Dichlorophenol in Aqueous Systems under Simulated and Natural Sunlight

    Directory of Open Access Journals (Sweden)

    Dorota Gryglik

    2016-01-01

    Full Text Available The work presents results of studies on 2,4-dichlorophenol (2,4-DCP degradation in aqueous solutions using photochemically initiated processes by simulated and natural sunlight. A number of possible substrate photodegradation routes were investigated, by both direct photolysis and photosensitized oxidation process. The major role of singlet oxygen in 2,4-DCP photodegradation was proved. Rose Bengal and derivatives of porphine and phthalocyanine were used as sensitizers. The influences of various process parameters on the reaction rate were investigated. On the basis of experimental data reaction rate constants of 2,4-DCP photosensitized oxidation were determined. The possibility of using natural sunlight to degrade 2,4-DCP in water in the middle latitudes was stated. The acute toxicity bioassay was conducted with the marine bacterium Vibrio fischeri as a bioluminescent indicator. The obtained results encourage further research on this process.

  18. Sensitized photoelectrolysis of water with sunlight. Final report, June 1, 1977-December 31, 1978

    Energy Technology Data Exchange (ETDEWEB)

    Ghosh, A.K.; Maruska, H.P.

    1978-12-01

    A study was made of solar driven water photoelectrolysis cells employing semiconductor electrodes. An extensive review of the literature was undertaken, and the three major problem areas for these devices were identified: corrosion, poor sunlight absorption, and external bias requirement. Although many semiconductors had been tested, none had proven free of all three defects. Two approaches were thus followed for the experimental studies: impurity sensitization of wide band gap stable oxides, and heterostructure formation between unstable sunlight absorbers and corrosion resistant oxides. Water decomposition was achieved with visible light excitation of Cr-doped TiO/sub 2/. Transport properties were studies for TiO/sub 2/ and SrTiO/sub 3/ electrodes doped with V, Cr, Mn, Fe, Co, and Ni. The correlation between bias requirement and electron affinity of oxides was identified. Performance of heterostructure electrodes was shown to be limited either by pin hole problems or by potential barriers between the valence bands.

  19. Uranium industry annual 1995

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-05-01

    The Uranium Industry Annual 1995 (UIA 1995) provides current statistical data on the U.S. uranium industry`s activities relating to uranium raw materials and uranium marketing. The UIA 1995 is prepared for use by the Congress, Federal and State agencies, the uranium and nuclear electric utility industries, and the public. It contains data for the period 1986 through 2005 as collected on the Form EIA-858, ``Uranium Industry Annual Survey``. Data collected on the ``Uranium Industry Annual Survey`` provide a comprehensive statistical characterization of the industry`s plans and commitments for the near-term future. Where aggregate data are presented in the UIA 1995, care has been taken to protect the confidentiality of company-specific information while still conveying accurate and complete statistical data. Data on uranium raw materials activities for 1986 through 1995 including exploration activities and expenditures, EIA-estimated reserves, mine production of uranium, production of uranium concentrate, and industry employment are presented in Chapter 1. Data on uranium marketing activities for 1994 through 2005, including purchases of uranium and enrichment services, enrichment feed deliveries, uranium fuel assemblies, filled and unfilled market requirements, uranium imports and exports, and uranium inventories are shown in Chapter 2. The methodology used in the 1995 survey, including data edit and analysis, is described in Appendix A. The methodologies for estimation of resources and reserves are described in Appendix B. A list of respondents to the ``Uranium Industry Annual Survey`` is provided in Appendix C. For the reader`s convenience, metric versions of selected tables from Chapters 1 and 2 are presented in Appendix D along with the standard conversion factors used. A glossary of technical terms is at the end of the report. 14 figs., 56 tabs.

  20. Attitude of future healthcare provider towards vitamin D significance in relation to sunlight exposure.

    Science.gov (United States)

    Qureshi, Aysha Zia; Zia, Zubia; Gitay, Mehnaz Nuruddin; Khan, Muhammad Umair; Khan, Muhammad Saad

    2015-10-01

    Nature is the kindest of all to provide man with all the necessary components for a healthy life at easily accessible lengths. The deprivation arises with unawareness and lack of correct measures to extract the benefits. Medical education makes the youth aware of the numerous disorders and diseases, as well as their preventions and treatments. This awareness needs to be realized and implemented in the society, and it is not possible without the advisers acting on the same lines. Since doctors are the most trusted and their advice is adopted without much thought, it is extremely inevitable to analyze the attitude of medical students of various levels to understand the cause of their negligence toward their own deficiencies, the focus for this study being vitamin D (VD). A cross sectional descriptive study was done on undergraduate medical students of health profession from different universities of Pakistan to access the awareness regarding VD deficiency associated with sunlight. Informed consent was duly signed by each participant after which self-constructed questionnaire was provided to them and data are collected. SPSS 17 was used for Statistical analysis. Final students are well aware of VD significance, take food rich in VD but still suffer from fatigue and muscular pain. No treatment was taken for fatigue and muscular pain by majority of these sufferers and those who took treatment were VD supplement. The health sufferers were mostly those who avoided sunlight highlighting the role of VD in maintaining an active lifestyle as well as the significance of sunlight in maintaining VD levels. It can be concluded that in spite of awareness, the role of sunlight exposure and the proper time and duration of exposure cannot be ignored to create a healthy and active society.

  1. Calculation of the optimum thickness of thermo-insulation for collectors of sunlight installations

    Directory of Open Access Journals (Sweden)

    Ermuratskii V.V.

    2005-12-01

    Full Text Available In the work the task of calculation of the optimum thickness of thermo-insulation for collectors of sunlight and accumulators of the heat is considered. The simplified model of calculation and the technique based on an estimation of efficiency of investment projects is offered. It is shown, that at calculation on the simplified model which are not taking into account financial streams, the overestimated values of thickness thermo-insulation turn out.

  2. Multiple scattering of polarized light in planetary atmospheres. II - Sunlight reflected by terrestrial water clouds.

    Science.gov (United States)

    Hansen, J. E.

    1971-01-01

    The intensity and polarization of sunlight reflected by terrestrial water clouds are computed with the doubling method. The calculations illustrate that this method can be effectively used in problems involving strongly anisotropic phase matrices. The method can, therefore, be used to derive information about planetary clouds, including those of the earth, from polarimetric observations. The results of the computations indicate that the polarization is more sensitive than the intensity to cloud microstructure, such as particle size and shape.

  3. The Photocatalytic Activity of TiO2-Zeolite Composite for Degradation of Dye Using Synthetic UV and Jeddah Sunlight

    Directory of Open Access Journals (Sweden)

    Laila M. Al-Harbi

    2015-01-01

    Full Text Available In this research different composites of impregnated TiO2 with LTA or FAU zeolites were used as different weight% ratio for photodegradation of organic dye. Normal laboratory UV-lamps were used as a source of UV irradiation. In addition a setup of system of mirrors was used to collect real Jeddah sunlight. A comparison of UV and real sunlight photodegradation activity showed that the real sunlight enhances new centers of active sites exhibiting higher catalytic activity than that of UV irradiated samples.

  4. Dissolved organic matter degradation by sunlight coagulates organo-mineral colloids and produces low-molecular weight fraction of metals in boreal humic waters

    Science.gov (United States)

    Oleinikova, Olga V.; Drozdova, Olga Yu.; Lapitskiy, Sergey A.; Demin, Vladimir V.; Bychkov, Andrey Yu.; Pokrovsky, Oleg S.

    2017-08-01

    Photochemical degradation of dissolved organic matter (DOM) is recognized as the major driver of CO2 emission to the atmosphere from the inland waters of high latitudes. In contrast to numerous studies of photo-induced DOM transformation, the behavior of trace element (TE) during photodegradation of boreal DOM remains virtually unknown. Towards a better understanding of concentration, size fractionation and speciation change of DOM and TE in boreal waters subjected to solar radiation, we conducted on-site photo-degradation experiments in stream and bog water collected from a pristine zone of the Northern Karelia (Russian subarctic). The removal of Fe and Al occurred only in the bog water (90% and 50% respectively, over 5 days of reaction), whereas no detectable decrease of dissolved (exposure to sunlight: Al, P, Ti, V, Cr, As, Y, Zr, REEs, Hf, Th, Pb and U. The second group of elements (Li, B, Mg, Ca, Sr, Ba, Na, K, Rb, Si, Mn, Ni, Cu, Co, Cd, Sb) was indifferent to photodegradation of DOM and exhibited a non-systematic variation (±10-15% from the control) of sunlight exposure. The bog water insolation yielded a factor of 3 ± 1 increase of low molecular weight (LMW sunlight exposure compared to the dark control. The LMW< 1 kDa fraction was preferentially enriched in Fe, Al, Ca, Mg and other divalent metals relative to Corg. The climate warming leading to water temperature rise in the boreal zone will intensify the Fe and Al hydroxide coagulation while increasing the production of LMW organic ligands and free metals and metal - organic complexes.

  5. Comparative Evaluation of Different Co-Antioxidants on the Photochemical- and Functional-Stability of Epigallocatechin-3-gallate in Topical Creams Exposed to Simulated Sunlight

    Directory of Open Access Journals (Sweden)

    Santo Scalia

    2013-01-01

    Full Text Available The catechin (−-epigallocatechin-3-gallate (EGCG exhibits high antioxidant activity and it has been reported to provide protection of the skin against damage induced by solar UV radiation. However, EGCG is highly unstable under sunlight. The present study aimed to compare the effectiveness of the co-antioxidant agents vitamin E, butylated hydroxytoluene, vitamin C and a-lipoic acid for their potential to protect the catechin from photochemical degradation. Model creams (oil-in-water emulsions containing EGCG (1%, w/w alone or combined with equimolar concentrations of co-antioxidant were exposed to a solar simulator at an irradiance corresponding to natural sunlight. Photodegradation was evaluated by HPLC-UV and HPLC-ESI-MS/MS. Addition of the co-antioxidants vitamin C and a-lipoic acid to the formulation significantly reduced the light-induced decomposition of EGCG from 76.9 ± 4.6% to 20.4 ± 2.7% and 12.6 ± 1.6%, respectively. Conversely, butylated hydroxytoluene had no effect (EGCG loss, 78.1 ± 4.6% and vitamin E enhanced the EGCG photolysis to 84.5 ± 3.4%. The functional stability of the catechin in the creams exposed to the solar simulator was also evaluated by measuring the in vitro antioxidant activity. Following irradiation, the reduction of the EGCG formulation antioxidant power was lower (21.8% than the extent of degradation (76.9%, suggesting the formation of photoproducts with antioxidant properties. The influence of the examined co-antioxidants on the functional stability of the catechin under simulated sunlight paralleled that measured for the EGCG photodecomposition, a-lipoic acid exerting the greatest stabilising effect (antioxidant activity decrease, 1.4%. These results demonstrated that a-lipoic acid is an effective co-antioxidant agent for the stabilization of EGCG in dermatological products for skin photoprotection.

  6. Spore sensitivity to sunlight and freezing can restrict dispersal in wood-decay fungi.

    Science.gov (United States)

    Norros, Veera; Karhu, Elina; Nordén, Jenni; Vähätalo, Anssi V; Ovaskainen, Otso

    2015-08-01

    Assessment of the costs and benefits of dispersal is central to understanding species' life-history strategies as well as explaining and predicting spatial population dynamics in the changing world. While mortality during active movement has received much attention, few have studied the costs of passive movement such as the airborne transport of fungal spores. Here, we examine the potential of extreme environmental conditions to cause dispersal mortality in wood-decay fungi. These fungi play a key role as decomposers and habitat creators in forest ecosystems and the populations of many species have declined due to habitat loss and fragmentation. We measured the effect of simulated solar radiation (including ultraviolet A and B) and freezing at -25°C on the spore germinability of 17 species. Both treatments but especially sunlight markedly reduced spore germinability in most species, and species with thin-walled spores were particularly light sensitive. Extrapolating the species' laboratory responses to natural irradiance conditions, we predict that sunlight is a relevant source of dispersal mortality at least at larger spatial scales. In addition, we found a positive effect of spore size on spore germinability, suggesting a trade-off between dispersal distance and establishment. We conclude that freezing and particularly sunlight can be important sources of dispersal mortality in wood-decay fungi which can make it difficult for some species to colonize isolated habitat patches and habitat edges.

  7. Bait Formulations of Chlorophyllin against Infected/Uninfected Lymnaea acuminata in Red and Sunlight

    Directory of Open Access Journals (Sweden)

    Navneet Kumar

    2015-01-01

    Full Text Available Control of snail population is an important tool in fasciolosis control programme. In order to achive this objective the method of bait formulation containing an attractant and a molluscicide is an appropriate approach to ensure the death of host snail. Chlorophyllin bait pellets were prepared by addition of attractants starch (10 mM/serine (20 mM and Chlorophyllin 2% agar solution. These baits were used against host snail Lymnaea acuminata. The behavioral response of snail against attractant (starch/serine and chlorophyllin was examined in red and sunlight. The fraction of snail that was in contact with chlorophyllin bait in zone-3 was used as measure of attraction process. Infected snails were more attracted with red light+starch (57.7%. Uninfected snails were more attracted by red light+serine (58.0%. The molluscicidal activity of chlorophyllin against infected snails in red light (96h LC50-1.88% chlorophyllin in bait and sunlight (96h LC50-2.40% chlorophyllin in bait was more pronounced than uninfected snail in red light (96h LC50-1.76% Chlorophyllin in bait and sunlight (96h LC50-3.62% chlorophyllin in bait.

  8. Perfluorooctanoic acid degradation in the presence of Fe(III) under natural sunlight

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Dandan [Beijing Key Laboratory of Water Resource and Environmental Engineering, China University of Geosciences, Beijing 100083 (China); Xiu, Zongming [Department of Civil and Environmental Engineering, Rice University, Houston, TX 77005 (United States); Liu, Fei [Beijing Key Laboratory of Water Resource and Environmental Engineering, China University of Geosciences, Beijing 100083 (China); Wu, Gang [Division of Hematology, Department of Internal Medicine, University of Texas-Medical School at Houston, Houston, TX 77030 (United States); Adamson, Dave; Newell, Charles [GSI Environmental Inc., Houston, TX 77098 (United States); Vikesland, Peter [Department of Civil and Environmental Engineering, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061 (United States); Tsai, Ah-Lim [Division of Hematology, Department of Internal Medicine, University of Texas-Medical School at Houston, Houston, TX 77030 (United States); Alvarez, Pedro J., E-mail: alvarez@rice.edu [Department of Civil and Environmental Engineering, Rice University, Houston, TX 77005 (United States)

    2013-11-15

    Highlights: • PFOA was photo-chemically decomposed in the presence of Fe(III) and natural sunlight. • An alternative reaction pathway involves hydroxyl radical as confirmed by EPR. • Common oxidant-persulfate increased PFOA defluorination extent. -- Abstract: Due to the high bond dissociation energy (BDE) of C-F bonds (116 kcal/mol), perfluorooctanoic acid (PFOA) is a highly recalcitrant pollutant. Herein, we demonstrate a novel method to decompose PFOA in the presence of sunlight and ferric iron (Fe(III)). Under such conditions, 97.8 ± 1.7% of 50 μM PFOA decomposed within 28 days into shorter-chain intermediates and fluoride (F{sup −}), with an overall defluorination extent of 12.7 ± 0.5%. No PFOA was removed under visible light, indicating that UV radiation is required for PFOA decomposition. Spectroscopic analysis indicates that the decomposition reaction is likely initiated by electron-transfer from PFOA to Fe(III), forming Fe(II) and an unstable organic carboxyl radical. An alternative mechanism for the formation of this organic radical involves hydroxyl radicals, detected by electron paramagnetic resonance (EPR). The observation that PFOA can be degraded by Fe(III) under solar irradiation provides mechanistic insight into a possibly overlooked natural attenuation process. Because Fe(III) is abundant in natural waters and sunlight is essentially free, this work represents a potentially important step toward the development of simple and inexpensive remediation strategies for PFOA-contaminated water.

  9. Colour Changes Evaluation of Freshly Cut Alder Veneers Under the Influence of Indoor Sunlight

    Directory of Open Access Journals (Sweden)

    Emilia Adela SALCA

    2011-03-01

    Full Text Available The paper presents an experimental study concerning the colour changes occurred on the surfaces ofblack alder veneers (Alnus glutinosa, obtained from a freshly cut (not treated log, after their exposure tosunlight and darkness, for 1 and 3 months, under indoor conditions.A Chroma Meter Konika Minolta CR-410 device was used for colour measurement.The colorimetric coordinates were recorded before and after the exposure, according to ISO 7724-2.The results highlight a significant decrease of colour lightness, right after the first month of sunlight exposure.The a* and b* colour coordinates showed an increasing tendency with increasing exposure time, whichsignifies a colour darkening under sunlight radiation that penetrates the window glass. Colour differenceswere noticed right after the first month of sunlight exposure, while under darkness conditions, a relativecolour constancy was noticed, the colour changes being less pronounced, but yet perceptible by the humaneye.The study results complete the colorimetric database of veneers used in furniture industry, but theyalso contribute to the rehabilitation of black alder as a wood species with a real potential of use in furnitureindustry.

  10. Chemically derived luminescent graphene oxide nanosheets and its sunlight driven photocatalytic activity against methylene blue dye

    Science.gov (United States)

    Kumar, Sumeet; Kumar, Ashok

    2016-12-01

    In the present work, graphene oxide (GO) nanosheets (NSs) have been synthesized with precise control over their thickness and molecular structure. The existence of oxygen containing functional groups on GO NSs through chemical treatment confers remarkable optical properties on GO. XRD, TEM, Raman and FTIR techniques were used to confirm the phase and degree of oxidation, morphology, structural information and chemical structure of the synthesized GO NSs. UV-Vis. spectroscopy was employed to study the optical absorption properties of the synthesized GO NSs. The excitation wavelength dependent PL measurements of the synthesized GO NSs were carried out which could be useful for the design and development of GO based next generation optoelectronic devices. The most fascinating luminescent property of synthesized GO NSs is that its luminescence peak position can be easily tuned by only varying the excitation wavelength without significant changes in its size and chemical composition. In order to study the photocatalytic degradation of methylene blue (MB) dye using GO NSs as a photocatalyst, a sunlight driven photocatalytic activity has been performed. The degradation rate of MB dye becomes fast when GO NSs are added to the dye solution. The photodegradation efficiency of GO NSs is calculated to be 60%. The present results indicate that synthesized GO NSs can be used as sunlight active photocatalyst. The optimistic response to sunlight irradiation validates the potential of GO NSs in solar energy conversion.

  11. Spectroscopic properties of Er doped and Er, Nd codoped fluoride glasses under simulated sunlight illumination

    Science.gov (United States)

    Mizuno, Shintaro; Ito, Hiroshi; Hasegawa, Kazuo; Kawai, Hiroyuki; Nasu, Hiroyuki; Hughes, Mark A.; Suzuki, Takenobu; Ohishi, Yasutake

    2011-10-01

    We investigated the fluorescence characteristics of Er codoped Nd doped ZBLAN glasses proposed for solar pumped fiber laser (SPFL) under simulated sunlight. Er is used as a sensitizer because it absorbs a part of the ultraviolet and visible light where is no absorption of Nd. Under simulated sunlight illumination, Er singly doped fluoride glass displayed four emission bands with peaks at 550, 848, 977 and 1533 nm attributed to the 4S 3/2- 4I 15/2, 4S 3/2- 4I 13/2, 4I 11/2- 4I 15/2 and 4I 13/2- 4I 15/2 electronic transitions of Er, respectively. The quantum efficiency measurement was carried out using an integrating sphere and under the simulated sunlight excitation showed a maximum of 73% for 0.5 mol.% of ErF 3 in ZBLAN glass. In Nd, Er codoped fluoride glass, the 1.05 μm emission of Nd was observed under 380 nm excitation what supposes the energy transfer from Er to Nd in ZBLAN glasses as Nd has no absorption at the wavelength. Er, Nd codoped fluoride glasses are promising as a sensitized laser media for solar pumped fiber lasers.

  12. Scattering Solar Thermal Concentrators

    Energy Technology Data Exchange (ETDEWEB)

    Giebink, Noel C. [Pennsylvania State Univ., State College, PA (United States)

    2015-01-31

    This program set out to explore a scattering-based approach to concentrate sunlight with the aim of improving collector field reliability and of eliminating wind loading and gross mechanical movement through the use of a stationary collection optic. The approach is based on scattering sunlight from the focal point of a fixed collection optic into the confined modes of a sliding planar waveguide, where it is transported to stationary tubular heat transfer elements located at the edges. Optical design for the first stage of solar concentration, which entails focusing sunlight within a plane over a wide range of incidence angles (>120 degree full field of view) at fixed tilt, led to the development of a new, folded-path collection optic that dramatically out-performs the current state-of-the-art in scattering concentration. Rigorous optical simulation and experimental testing of this collection optic have validated its performance. In the course of this work, we also identified an opportunity for concentrating photovoltaics involving the use of high efficiency microcells made in collaboration with partners at the University of Illinois. This opportunity exploited the same collection optic design as used for the scattering solar thermal concentrator and was therefore pursued in parallel. This system was experimentally demonstrated to achieve >200x optical concentration with >70% optical efficiency over a full day by tracking with <1 cm of lateral movement at fixed latitude tilt. The entire scattering concentrator waveguide optical system has been simulated, tested, and assembled at small scale to verify ray tracing models. These models were subsequently used to predict the full system optical performance at larger, deployment scale ranging up to >1 meter aperture width. Simulations at an aperture widths less than approximately 0.5 m with geometric gains ~100x predict an overall optical efficiency in the range 60-70% for angles up to 50 degrees from normal. However, the

  13. Sunlight creates oxygenated species in water-soluble fractions of Deepwater horizon oil

    Energy Technology Data Exchange (ETDEWEB)

    Ray, Phoebe Z. [Department of Chemistry, University of New Orleans, New Orleans, LA 70148 (United States); Chen, Huan [National High Magnetic Field Laboratory, Florida State University, 1800 East Paul Dirac Drive, Tallahassee, FL 32310-4005 (United States); Podgorski, David C. [National High Magnetic Field Laboratory, Florida State University, 1800 East Paul Dirac Drive, Tallahassee, FL 32310-4005 (United States); Future Fuels Institute, Florida State University, 1800 East Paul Dirac Drive, Tallahassee, FL 32310-4005 (United States); McKenna, Amy M. [National High Magnetic Field Laboratory, Florida State University, 1800 East Paul Dirac Drive, Tallahassee, FL 32310-4005 (United States); Tarr, Matthew A., E-mail: mtarr@uno.edu [Department of Chemistry, University of New Orleans, New Orleans, LA 70148 (United States)

    2014-09-15

    Graphical abstract: Sunlight oxygenates petroleum. - Highlights: • Oxidation seen in water-soluble oil fraction after exposure to simulated sunlight. • Oxygen addition occurred across a wide range of carbon number and DBE. • Oil compounds were susceptible to addition of multiple oxygens to each molecule. • Results provide understanding of fate of oil on water after exposure to sunlight. - Abstract: In order to assess the impact of sunlight on oil fate, Macondo well oil from the Deepwater Horizon (DWH) rig was mixed with pure water and irradiated with simulated sunlight. After irradiation, the water-soluble organics (WSO) from the dark and irradiated samples were extracted and characterized by ultrahigh resolution Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS). Liquid–liquid extraction yielded two fractions from dark and irradiated water/oil mixtures: acidic WSOs (negative-ion electrospray (ESI)), and base/neutral WSOs (positive-ion ESI) coupled to FT-ICR MS to catalog molecular-level transformations that occur to Macondo-derived WSOs after solar irradiation. Such direct measure of oil phototransformation has not been previously reported. The most abundant heteroatom class detected in the irradiated WSO acid fractions correspond to molecules that contain five oxygens (O{sub 5}), while the most abundant acids in the dark samples contain two oxygen atoms per molecule (O{sub 2}). Higher-order oxygen classes (O{sub 5}–O{sub 9}) were abundant in the irradiated samples, but <1.5% relative abundance in the dark sample. The increased abundance of higher-order oxygen classes in the irradiated samples relative to the dark samples indicates that photooxidized components of the Macondo crude oil become water-soluble after irradiation. The base/neutral fraction showed decreased abundance of pyridinic nitrogen (N{sub 1}) concurrent with an increased abundance of N{sub 1}O{sub x} classes after irradiation. The predominance of higher

  14. Why We Need More Nature at Work: Effects of Natural Elements and Sunlight on Employee Mental Health and Work Attitudes.

    Directory of Open Access Journals (Sweden)

    Mihyang An

    Full Text Available This study investigated the effects of natural elements and direct and indirect sunlight exposure on employee mental health and work attitudes. We recruited participants via an online panel from the United States and India, and analyzed data from 444 employees. Natural elements and sunlight exposure related positively to job satisfaction and organizational commitment, and negatively to depressed mood and anxiety. Direct sunlight was a dominant predictor of anxiety; indirect sunlight was a dominant predictor of depressed mood, job satisfaction, and organizational commitment. Natural elements buffered the relationship between role stressors and job satisfaction, depressed mood, and anxiety. We also found that depressed mood partially mediated the relationship between natural elements and job satisfaction. We discuss scientific and policy implications of these findings.

  15. Interacting effects of sunlight, agriculturally derived dissolved organic matter and reactive oxygen species on fecal indicator bacteria growth dynamics

    Science.gov (United States)

    Bacterial survival in agriculturally impacted surface waters is dependent on resource availability and also on potential resource transformations, mediated by biotic and abiotic processes. In this study, we focused on the effect of sunlight irradiated cattle fecal extract (CFE) a...

  16. 10-kilowatt Photovoltaic Concentrator Array

    Energy Technology Data Exchange (ETDEWEB)

    Donovan, R.L.; Broadbent, S.

    1978-05-01

    Martin Marietta has designed a Photovoltaic Concentrator Array (PCA) for Sandia Laboratories, Kirtland AFB, New Mexico. The PCA is based on the use of an acrylic Fresnel lens to concentrate sunlight on high intensity solar cells. The objective of the development was to obtain economical photovoltaic power generation by replacing relatively high priced solar cells with low cost lenses. Consequently, a major task of the program was to optimize the design for minimum cost per unit power output. Major design aspects considered for optimization were the concentration ratio, size and shape of the Fresnel lens, array size and shape, structure minimization, tracking and control and the practical aspects of operation and maintenance. In addition to design of the complete array, several porototype photovoltaic concentrator module subassemblies were fabricated and delivered to Sandia for evaluation. These prototypes exceed the 9.0% efficiency requirement established for this program.

  17. Sunlight-stimulated phenylalanine ammonia-lyase (PAL) activity and anthocyanin accumulation in exocarp of ‘Mahajanaka’ mango

    OpenAIRE

    Kobkiat Saengnil

    2011-01-01

    The activity of phenylalanine ammonia-lyase (PAL) required for anthocyanin synthesis was stimulated by sunlight exposure resulting in the development of red colour in ‘Mahajanaka’ mango exocarp, which occurred only on the sunlight-exposed side of the fruit. The accumulation of anthocyanin was concurrent with the increase in PAL activity in the mature stage of the fruit. The exposed side of the fruit had higher PAL activity, endogenous sugar content, and anthocyanin accumulation than the unexp...

  18. Sunlight mediated synthesis of silver nanoparticles using redox phytoprotein and their application in catalysis and colorimetric mercury sensing.

    Science.gov (United States)

    Ahmed, Khan Behlol Ayaz; Senthilnathan, Rajendran; Megarajan, Sengan; Anbazhagan, Veerappan

    2015-10-01

    Owing to the benign nature, plant extracts mediated green synthesis of metal nanoparticles (NPs) is rapidly expanding. In this study, we demonstrated the successful green synthesis of silver nanoparticles (AgNPs) by utilizing natural sunlight and redox protein complex composed of ferredoxin-NADP(+) reductase (FNR) and ferredoxin (FD). The capping and stabilization of the AgNPs by the redox protein was confirmed by Fourier transform infrared spectroscopy. Light and redox protein is the prerequisite factor for the formation of AgNPs. The obtained result shows that the photo generated free radicals by the redox protein is responsible for the reduction of Ag(+) to Ag(0). Transmission electron microscopy revealed the formation of spherical AgNPs with size ranging from 10 to 15 nm. As-prepared AgNPs exhibit excellent catalytic activity toward the degradation of hazardous organic dyes, such as methylene blue, methyl orange and methyl red. These bio-inspired AgNPs is highly sensitive and selective in sensing hazardous mercury ions in the water at micromolar concentration. In addition, FNR/FD extract stabilized AgNPs showed good antimicrobial activity against gram positive and gram negative bacteria.

  19. Sunlight-driven photocatalytic degradation of non-steroidal anti-inflammatory drug based on TiO₂ quantum dots.

    Science.gov (United States)

    Kaur, Amandeep; Umar, Ahmad; Kansal, Sushil Kumar

    2015-12-01

    This paper reports the facile synthesis, characterization and solar-light driven photocatalytic degradation of TiO2 quantum dots (QDs). The TiO2 QDs were synthesized by a facile ultrasonic-assisted hydrothermal process and characterized in terms of their structural, morphological, optical and photocatalytic properties. The detailed studies confirmed that the prepared QDs are well-crystalline, grown in high density and exhibiting good optical properties. Further, the prepared QDs were efficiently used as effective photocatalyst for the sun-light driven photocatalytic degradation of ketorolac tromethamine, a well-known non-steroidal anti-inflammatory drug (NSAID). To optimize the photocatalytic degradation conditions, various dose-dependent, pH-dependent, and initial drug-concentration dependent experiments were performed. The detailed solar-light driven photocatalytic experiments revealed that ∼99% photodegradation of ketorolac tromethamine drug solution (10 mg L(-1)) was observed with optimized amount of TiO2 QDs and pH (0.5 g L(-1) and 4.4, respectively) under solar-light irradiations. The observed results demonstrate that simply synthesized TiO2 QDs can efficiently be used for the solar-light driven photocatalytic degradation of harmful drugs and chemicals.

  20. Photolysis of pharmaceuticals and personal care products in the marine environment under simulated sunlight conditions: irradiation and identification.

    Science.gov (United States)

    Ali, Aasim Musa Mohamed; Kallenborn, Roland; Sydnes, Leiv Kristen; Rønning, Helene Thorsen; Alarif, Walied Mohamed; Al-Lihaibi, Sultan

    2017-06-01

    The photochemical fate of 16 pharmaceuticals and personal care products (PPCPs) found in the environment has been studied under controlled laboratory conditions applying a sunlight simulator. Aqueous samples containing PPCPs at environmentally relevant concentrations were extracted by solid-phase extraction (SPE) after irradiation. The exposed extracts were subsequently analysed by liquid chromatography combined with triple quadrupole mass spectrometry (HPLC-MS/MS) for studying the kinetics of photolytic transformations. Almost all exposed PPCPs appeared to react with a half-life time (τ 1/2) of less than 30 min. For ranitidine, sulfamethoxazole, diclofenac, warfarin, sulfamethoxazole and ciprofloxacin, τ1/2 was found to be even less than 5 min. The structures of major photolysis products were determined using quadrupole-time-of-flight mass spectrometry (QToF) and spectroscopic data reported in the literature. For diclofenac, the transformation products carbazol-1-yl-acidic acid and 8-chloro-9H-carbazol-1-yl-acetic acid were identified based on the mass/charge ratio of protonated ions and their fragmentation pattern in negative electrospray ionization (ESI(-)-QTOF). Irradiation of carbamazepine resulted in three known products: acridine, carbamazepine-10,11-epoxide, and 10,11-dihydro-10,11-dihydroxy-carbamazepine, whereas acetaminophen was photolytically transformed to 1-(2-amino-5 hydroxyphenyl) ethenone. These photochemical products were subsequently identified in seawater or fish samples collected at sites exposed to wastewater effluents on the Saudi Arabian coast of the Red Sea.

  1. A sunlight-induced method for rapid biosynthesis of silver nanoparticles using an Andrachnea chordifolia ethanol extract

    Science.gov (United States)

    Karimi Zarchi, A. A.; Mokhtari, N.; Arfan, M.; Rehman, T.; Ali, M.; Amini, M.; Faridi Majidi, R.; Shahverdi, A. R.

    2011-05-01

    In this study a sunlight-induced method for rapid synthesis of silver nanoparticles using an ethanol extract of Andrachnea chordifolia is described. The silver nitrate solutions (1 mM) containing the ethanol extract of Andrachnea chordifolia were irradiated by both sunlight radiation and by sunlight radiation passed through different colored filters (red, yellow or green). The smallest size of silver nanoparticles was obtained when a silver ion solution was irradiated for 5 minutes by direct sunlight radiation. Further examination of the shape and size and of the surface chemistry of these biogenic silver nanoparticles, which were prepared under sunlight radiation, was carried out using transmission electron microscopy and infrared spectroscopy, respectively. Transmission electron microscopy images show spherical particles with an average size of 3.4 nm. Hydroxyl residues were also detected on the surface of these biogenic silver nanoparticles fabricated using plant extract of Andrachnea chordifolia under sunlight radiation. Our study on the reduction of silver ions by this plant extract in darkness shows that the synthesis process can take place under dark conditions at much longer incubations (48 hours). Larger silver polydispersed nanoparticles ranging in size from 3 to 30 nm were obtained when the silver ions were treated with the ethanol extract of Andrachnea chordifolia under dark conditions for 48 hours.

  2. Development and validation of sunlight exposure measurement questionnaire (SEM-Q) for use in adult population residing in Pakistan.

    Science.gov (United States)

    Humayun, Quratulain; Iqbal, Romaina; Azam, Iqbal; Khan, Aysha Habib; Siddiqui, Amna Rehana; Baig-Ansari, Naila

    2012-06-08

    Vitamin D deficiency has been identified as a major public health problem worldwide. Sunlight is the main source of vitamin D and its measurement using dosimeters is expensive and difficult for use in population-based studies. Hence, the aim of this study was to develop and validate questionnaires to assess sunlight exposure in healthy individuals residing in Karachi, Pakistan. Two questionnaires with seven important items for sunlight exposure assessment were developed. Fifty four healthy adults were enrolled based on their reported sunlight exposure (high = 17, moderate = 18, low = 19) from Aga Khan University, Karachi. Over four days, study participants were asked to wear a dosimeter between sunrise and sunset and report time spent and activities undertaken in the sun for questionnaire validation. Algorithm for item weightage was created as an average score based on ultraviolet B percentage received. Blood samples were obtained for serum vitamin D. The mean time (minutes) spent in sun over 4 days (±SD) was 69.5 (±32) for low, 83.5 (±29.7) for moderate and 329 (±115) for high exposure group. The correlation between average time (minutes) spent in sun over 4 days and mean change in absorbance of UV dosimeters for 4 days was 0.60 (p sunlight exposure measurement questionnaires were valid tools for use in large epidemiological studies to quantify sunlight exposure.

  3. A sunlight-induced method for rapid biosynthesis of silver nanoparticles using an Andrachnea chordifolia ethanol extract

    Energy Technology Data Exchange (ETDEWEB)

    Karimi Zarchi, A.A.; Faridi Majidi, R. [Tehran University of Medical Sciences, Department of Nanomedicine, School of Advanced Medical Technologies, Tehran (Iran, Islamic Republic of); Mokhtari, N.; Shahverdi, A.R. [Tehran University of Medical Sciences, Department of Pharmaceutical Biotechnology and Medicinal Plants Research Center, Faculty of Pharmacy, Tehran (Iran, Islamic Republic of); Arfan, M.; Rehman, T.; Ali, M. [University of Peshawar, Institute of Chemical Sciences, Peshawar, Khyber Pakhtoonkhwa (Pakistan); Amini, M. [Tehran University of Medical Sciences, Department of Medicinal Chemistry, Faculty of Pharmacy, Tehran (Iran, Islamic Republic of)

    2011-05-15

    In this study a sunlight-induced method for rapid synthesis of silver nanoparticles using an ethanol extract of Andrachnea chordifolia is described. The silver nitrate solutions (1 mM) containing the ethanol extract of Andrachnea chordifolia were irradiated by both sunlight radiation and by sunlight radiation passed through different colored filters (red, yellow or green). The smallest size of silver nanoparticles was obtained when a silver ion solution was irradiated for 5 minutes by direct sunlight radiation. Further examination of the shape and size and of the surface chemistry of these biogenic silver nanoparticles, which were prepared under sunlight radiation, was carried out using transmission electron microscopy and infrared spectroscopy, respectively. Transmission electron microscopy images show spherical particles with an average size of 3.4 nm. Hydroxyl residues were also detected on the surface of these biogenic silver nanoparticles fabricated using plant extract of Andrachnea chordifolia under sunlight radiation. Our study on the reduction of silver ions by this plant extract in darkness shows that the synthesis process can take place under dark conditions at much longer incubations (48 hours). Larger silver polydispersed nanoparticles ranging in size from 3 to 30 nm were obtained when the silver ions were treated with the ethanol extract of Andrachnea chordifolia under dark conditions for 48 hours. (orig.)

  4. A simple and low-cost approach to fabricate TiO{sub 2}-NO{sub 2} hollow spheres with excellent simulated sunlight photocatalytic activity

    Energy Technology Data Exchange (ETDEWEB)

    Li, Kexin; Liu, Shufen; Yi, Shaoting; Yan, Liushui, E-mail: yanliushui@hotmail.com; Guo, Huiqin; Dai, Yuhua; Luo, Xubiao; Luo, Shenglian, E-mail: sllou@hnu.edu.cn

    2016-09-15

    Nitryl surface functionalized TiO{sub 2} hollow spheres (TiO{sub 2}-NO{sub 2} HSs) composite material was successfully fabricated by a simple sol-gel combined with solvothermal and concentrated HNO{sub 3} treatment strategy using carbon microspheres obtained from hydrothermal carbonization of waste Camellia oleifera shells as a template. The microstructure, surface property, compositional and structural information, and optical and electronic property of as-prepared TiO{sub 2}-NO{sub 2} HSs were well characterized. Compare with conventional g-C{sub 3}N{sub 4} and TiO{sub 2} photocatalysts, the as-prepared TiO{sub 2}-NO{sub 2} HSs exhibited excellent simulated sunlight photocatalytic activity toward aqueous organic pollutants degradation and hydrogen evolution from water-splitting, which can be attributed to their unique hollow spherical microstructure and the introduction of -NO{sub 2} groups. - Highlights: • TiO{sub 2}-NO{sub 2} HSs were successfully fabricated by a simple and low-cost method. • Their morphology, composition, and optoelectronic property were well characterized. • TiO{sub 2}-NO{sub 2} HSs exhibit considerably high activity under simulated sunlight irradiation. • High activity is attributed to hollow spherical structure and introduced -NO{sub 2} groups.

  5. Study of organic photovoltaics by localized concentrated sunlight: towards optimization of charge collection in large-area solar cells

    NARCIS (Netherlands)

    Manor, A.; Katz, E.A.; Andriessen, H.A.J.M.; Galagan, Y.O.

    2011-01-01

    Large-area organic solar cells are known to suffer from a major efficiency decrease which originates from the combination of a voltage drop across the front electrode and the voltage-dependent photocurrent. In this letter, we demonstrate this efficiency loss on large area, indium tin oxide free cell

  6. Study of organic photovoltaics by localized concentrated sunlight: towards optimization of charge collection in large-area solar cells

    NARCIS (Netherlands)

    Manor, A.; Katz, E.A.; Andriessen, H.A.J.M.; Galagan, Y.O.

    2011-01-01

    Large-area organic solar cells are known to suffer from a major efficiency decrease which originates from the combination of a voltage drop across the front electrode and the voltage-dependent photocurrent. In this letter, we demonstrate this efficiency loss on large area, indium tin oxide free cell

  7. Solar thermal power plants. Use of concentrated sunlight for power generation; Solarthermische Kraftwerke. Konzentriertes Sonnenlicht zur Energieerzeugung nutzen

    Energy Technology Data Exchange (ETDEWEB)

    Pitz-Paal, Robert; Hennecke, Klaus; Heller, Peter; Buck, Reiner [Deutsches Zentrum fuer Luft- und Raumfahrt, Koeln-Porz (Germany). Inst. fuer Solarforschung

    2013-11-01

    This Themeninfo presents at the basics of solar thermal systems, their technical components and the application potential as well as examples from practice. [German] Dieses Themeninfo geht auf die Grundlagen solarthermischer Anlagen, ihre technischen Komponenten und das Anwendungspotenzial ein und zeigt Beispiele aus der Praxis.

  8. Formation of rutile fasciculate zone induced by sunlight irradiation at room temperature and its hemocompatibility

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Xuan-Hui; Zheng, Xiang; Cheng, Yuan [School of Chemical Engineering and Materials Science, Zhejiang University of Technology, Hangzhou 310014 (China); Li, Guo-Hua, E-mail: nanozjut@zjut.edu.cn [School of Chemical Engineering and Materials Science, Zhejiang University of Technology, Hangzhou 310014 (China); State Key Laboratory Breeding Base of Green Chemistry Synthesis Technology, Zhejiang University of Technology, Hangzhou 310014 (China); Research Center of Nanoscience and Technology, Zhejiang University of Technology, Hangzhou 310014 (China); Chen, Xiao-Ping, E-mail: chxp@zjut.edu.cn [School of Biological and Environmental Engineering, Zhejiang University of Technology, Hangzhou 310014 (China); Zheng, Jian-Hui [School of Biological and Environmental Engineering, Zhejiang University of Technology, Hangzhou 310014 (China)

    2013-08-01

    The fasciculate zone of phase pure rutile was fabricated under sunlight irradiation at room temperature, using titanium tetrachloride as a sole precursor. The crystal phase, morphology and microstructure, and optical absorption behavior of the samples were characterized by X-ray Diffraction, High-Resolution Transmission Electron Microscope (HRTEM) and UV–vis Diffuse Reflectance Spectra (DRS), respectively. XRD results show that the crystal phase of the sample is composed of rutile only, and a lattice distortion displays in the crystallite of the sample. HRTEM results show that the morphology of rutile particle is fasciculate zone constituted of nanoparticles with a diameter of 4–7 nm, and these particles grow one by one and step by step. The pattern of the selected area electron diffraction of the sample is Kikuchi type, which can be attributed to the predominant orientation growth of rutile nanoparticles along [001] induced by sunlight irradiation. DRS results show that the absorption threshold of the sample is 415 nm, corresponding to the band gap energy of 2.99 eV, which is lower than the band gap energy of rutile, 3.03 eV. Blood compatibility measurement shows that the sample has no remarkable effect on hemolytic and coagulation activity. The percent hemolysis of red blood cells is less than 5% even treated with a big dosage of the fasciculate rutile and under UV irradiation, and there are no obvious changes of plasma recalcification time after the rutile treatment. Thus, the novel structure of rutile fasciculate has low potential toxicity for blood and is hemocompatibility safe. Highlights: • A novel approach to fabricate the fasciculate zone of phase pure rutile • The fasciculate grows from a particle to nanorod and to fasciculate, step by step. • A preferred orientation growth induced by sunlight irradiation in the fasciculate • The rutile fasciculate is low toxicity for blood and is hemocompatibility safe.

  9. Technoeconomic analysis of different options for the production of hydrogen from sunlight, wind, and biomass

    Energy Technology Data Exchange (ETDEWEB)

    Mann, M.K.; Spath, P.L.; Amos, W.A. [National Renewable Energy Lab., Golden, CO (United States)

    1998-08-01

    To determine their technical and economic viability and to provide insight into where each technology is in its development cycle, different options to produce hydrogen from sunlight, wind, and biomass were studied. Additionally, costs for storing and transporting hydrogen were determined for different hydrogen quantities and storage times. The analysis of hydrogen from sunlight examined the selling price of hydrogen from two technologies: direct photoelectrochemical (PEC) conversion of sunlight and photovoltaic (PV)-generated electricity production followed by electrolysis. The wind analysis was based on wind-generated electricity production followed by electrolysis. In addition to the base case analyses, which assume that hydrogen is the sole product, three alternative scenarios explore the economic impact of integrating the PV- and wind-based systems with the electric utility grid. Results show that PEC hydrogen production has the potential to be economically feasible. Additionally, the economics of the PV and wind electrolysis systems are improved by interaction with the grid. The analysis of hydrogen from biomass focused on three gasification technologies. The systems are: low pressure, indirectly-heated gasification followed by steam reforming; high pressure, oxygen-blown gasification followed by steam reforming; and pyrolysis followed by partial oxidation. For each of the systems studied, the downstream process steps include shift conversion followed by hydrogen purification. Only the low pressure system produces hydrogen within the range of the current industry selling prices (typically $0.7--$2/kg, or $5--14/GJ on a HHV basis). A sensitivity analysis showed that, for the other two systems, in order to bring the hydrogen selling price down to $2/kg, negative-priced feedstocks would be required.

  10. Photoreactivity of carboxylated single-walled carbon nanotubes in sunlight: reactive oxygen species production in water.

    Science.gov (United States)

    Chen, Chia-Ying; Jafvert, Chad T

    2010-09-01

    Very limited information exists on transformation processes of carbon nanotubes in the natural aquatic environment. Because the conjugated pi-bond structure of these materials is efficient in absorbing sunlight, photochemical transformations are a potential fate process with reactivity predicted to vary with their diameter, chirality, number and type of defects, functionalization, residual metal catalyst and amorphous carbon content, and with the composition of the water, including the type and composition of materials that act to disperse them into the aqueous environment. In this study, the photochemical reactions involving colloidal dispersions of carboxylated single-walled carbon nanotubes (SWNT-COOH) in sunlight were examined. Production of reactive oxygen species (ROS) during irradiation occurs and is evidence for potential further phototransformation and may be significant in assessing their overall environmental impacts. In aerated samples exposed to sunlight or to lamps that emit light only within the solar spectrum, the probe compounds, furfuryl alcohol (FFA), tetrazolium salts (NBT2+ and XTT), and p-chlorobenzoic acid (pCBA), were used to indicate production of 1O2, O2.-, and .OH, respectively. All three ROS were produced in the presence of SWNT-COOH and molecular oxygen (3O2). 1O2 production was confirmed by observing enhanced FFA decay in deuterium oxide, attenuated decay of FFA in the presence of azide ion, and the lack of decay of FFA in deoxygenated solutions. Photogeneration of O2.- and .OH was confirmed by applying superoxide dismutase (SOD) and tert-butanol assays, respectively. In air-equilibrated suspensions, the loss of 0.2 mM FFA in 10 mg/L SWNT-COOH was approximately 85% after 74 h. Production of 1O2 was not dependent on pH from 7 to 11; however photoinduced aggregation was observed at pH 3.

  11. The ability of periorbitally applied antiglare products to improve contrast sensitivity in conditions of sunlight exposure.

    Science.gov (United States)

    DeBroff, Brian M; Pahk, Patricia J

    2003-07-01

    Sun glare decreases athletes' contrast sensitivity and impairs their ability to distinguish objects from background. Many commercial products claim to reduce glare but have not been proven effective in clinical studies. To determine whether glare-reducing products such as eye black grease and antiglare stickers reduce glare and improve contrast sensitivity during sunlight exposure. We tested 46 subjects for contrast sensitivity using a Pelli-Robson contrast chart. Each subject served as an internal control and then was randomized to either application of eye black grease, antiglare stickers, or petroleum jelly at the infraorbital rim. All testing was performed in conditions of unobstructed sunlight. Analysis of variance revealed a significant difference between eye black grease (mean +/- SD, Pelli-Robson value, 1.87 +/- 0.09 logMAR units) and antiglare stickers (1.75 +/- 0.14 logMAR units) in binocular testing (P =.02). No statistical difference was found between the groups in right eyes, left eyes, or in combined data from the right and left eyes. Paired t tests demonstrated a significant difference between control (mean +/- SD, 1.77 +/- 0.14 logMAR units) and eye black grease (1.87 +/- 0.09 logMAR units) in binocular testing (P =.04). There was also a significant difference between control (mean +/- SD, 1.65 +/- 0.05 logMAR units) and eye black grease (1.67 +/- 0.06 logMAR units) in combined data from the right and left eyes (P =.02). Eye black grease reduces glare and improves contrast sensitivity in conditions of sunlight exposure compared with the control and antiglare stickers in binocular testing.

  12. The genotoxic effects of DNA lesions induced by artificial UV-radiation and sunlight.

    Science.gov (United States)

    Schuch, André Passaglia; Menck, Carlos Frederico Martins

    2010-06-01

    Solar radiation sustains and affects all life forms on Earth. The increase in solar UV-radiation at environmental levels, due to depletion of the stratospheric ozone layer, highlights serious issues of social concern. This becomes still more dramatic in tropical and subtropical regions where radiation-intensity is still higher. Thus, there is the need to evaluate the harmful effects of solar UV-radiation on the DNA molecule as a basis for assessing the risks involved for human health, biological productivity and ecosystems. In order to evaluate the profile of DNA damage induced by this form of radiation and its genotoxic effects, plasmid DNA samples were exposed to artificial-UV lamps and directly to sunlight. The induction of cyclobutane pyrimidine dimer photoproducts (CPDs) and oxidative DNA damage in these molecules were evaluated by means of specific DNA repair enzymes. On the other hand, the biological effects of such lesions were determined through the analysis of the DNA inactivation rate and mutation frequency, after replication of the damaged pCMUT vector in an Escherichia coliMBL50 strain. The results indicated the induction of a significant number of CPDs after exposure to increasing doses of UVC, UVB, UVA radiation and sunlight. Interestingly, these photoproducts are those lesions that better correlate with plasmid inactivation as well as mutagenesis, and the oxidative DNA damages induced present very low correlation with these effects. The results indicated that DNA photoproducts play the main role in the induction of genotoxic effects by artificial UV-radiation sources and sunlight.

  13. Environmentally relevant impacts of nano-TiO2 on abiotic degradation of bisphenol A under sunlight irradiation.

    Science.gov (United States)

    Wu, Wei; Shan, Guoqiang; Wang, Shanfeng; Zhu, Lingyan; Yue, Longfei; Xiang, Qian; Zhang, Yinqing; Li, Zhuo

    2016-09-01

    Understanding the effects of nano-TiO2 particles on the environmental behaviors of organic pollutants in natural aquatic environments is of paramount importance considering that large amount of nano-TiO2 is being released in the environment. In this study, the effect of nano-TiO2 on the degradation of bisphenol A (BPA) in water was investigated under simulated solar light irradiation. The results indicated that nano-TiO2 at environmentally relevant concentration (1 mg/L) could significantly facilitate the abiotic degradation of BPA (also at low concentration) under mild solar light irradiation, with the pseudo first-order rate constant (kobs) for BPA degradation raised by 1-2 orders of magnitude. As reflected by the inhibition experiments, hydroxyl radicals (OHs) and superoxide radical species were the predominant active species responsible for BPA degradation. The reaction was affected by water pH, and the degradation rate was higher at acidic or alkaline conditions than that at neutral condition. Humic acid (HA) also affected the reaction rate, depending on its concentration. At lower concentration (the mass ratio of HA/nano-TiO2 was 0.1:1), HA improved the dispersion and stability of nano-TiO2 in aquatic environment. As a result, the yield of OHs by nano-TiO2 under sunlight irradiation increased and BPA degradation was facilitated. When the HA concentration increased, a coating of HA formed on the surface of nano-TiO2. Although nano-TiO2 became more stable, the light absorption by nano-TiO2 was significantly reduced due to the strong light absorption of the HA coated on the surface. As a consequence, the yield of OH decreased and BPA degradation was depressed. The results imply that nano-TiO2 at low concentration may distinctly mediate BPA degradation, and can contribute to the natural attenuation of some organic pollutants in aquatic environment with low level of HA. However, this process would be significantly reduced in the presence of high level of HA.

  14. Dispersed single-phase-step Michelson interferometer for Doppler imaging using sunlight.

    Science.gov (United States)

    Wan, Xiaoke; Ge, Jian

    2012-09-15

    A Michelson interferometer is dispersed with a fiber array-fed spectrograph, providing 59 Doppler sensing channels using sunlight in the 510-570 nm wavelength region. The interferometer operates at a single-phase-step mode, which is particularly advantageous in multiplexing and data processing compared to the phase-stepping mode of other interferometer spectrometer instruments. Spectral templates are prepared using a standard solar spectrum and simulated interferometer modulations, such that the correlation function with a measured 1D spectrum determines the Doppler shift. Doppler imaging of a rotating cylinder is demonstrated. The average Doppler sensitivity is ~12 m/s, with some channels reaching ~5 m/s.

  15. On the origin of the coherence of sunlight on the earth.

    Science.gov (United States)

    Sundaram, Sriram; Panigrahi, Prasanta K

    2016-09-15

    It is shown that the observed far-field behavior of sunlight on the earth's surface, located in the near-field region, is due to the small angular width it subtends at the center of the sun. The investigation of the angular behavior of the cross-spectral density function explicitly leads to Bessel-like far-zone behavior for a small angle without any restriction on the value of l. Our general analysis for the spherical source can be easily extended to other geometries.

  16. Influence of Sound Wave Stimulation on the Growth of Strawberry in Sunlight Greenhouse

    Science.gov (United States)

    Qi, Lirong; Teng, Guanghui; Hou, Tianzhen; Zhu, Baoying; Liu, Xiaona

    In this paper, we adopt the QGWA-03 plant audio apparatus to investigate the sound effects on strawberry in the leaf area, the photosynthetic characteristics and other physiological indexes. It was found that when there were no significant differences between the circumstances of the two sunlight greenhouses, the strawberry after the sound wave stimulation grew stronger than in the control and its leaf were deeper green, and shifted to an earlier time about one week to blossom and bear fruit. It was also found that the resistance of strawberry against disease and insect pest were enhanced. The experiment results show that sound wave stimulation can certainly promote the growth of plants.

  17. Sunlight-Induced Photochemical Degradation of Methylene Blue by Water-Soluble Carbon Nanorods

    Directory of Open Access Journals (Sweden)

    Anshu Bhati

    2016-01-01

    Full Text Available Water-soluble graphitic hollow carbon nanorods (wsCNRs are exploited for their light-driven photochemical activities under outdoor sunlight. wsCNRs were synthesized by a simple pyrolysis method from castor seed oil, without using any metal catalyst or template. wsCNRs exhibited the light-induced photochemical degradation of methylene blue used as a model pollutant by the generation of singlet oxygen species. Herein, we described a possible degradation mechanism of methylene blue under the irradiation of visible photons via the singlet oxygen-superoxide anion pathway.

  18. Bacterial growth in humic waters exposed to UV-radiation and simulated sunlight

    DEFF Research Database (Denmark)

    Corin, N.; Backlund, P.; Wiklund, T.

    1998-01-01

    Sterile filtered (0.45 mu m) humic lake water was exposed to simulated sunlight (300-800 nm) or W-radiation (254 run)for various periods of times and the dissolved organic carbon content, absorbance at 254 and 460 nm and PH were recorded. The irradiated water was inoculated with a natural bacterial...... in an increased availability of the dissolved organic material as bacterial substrate. No inhibitory effect on the bacterial growth, due to the presence of toxic organic reaction products, was observed. (C) 1998 Published by Elsevier Science Ltd....

  19. Sunlight simulators-the key to understanding the physiological effects of the sun

    CSIR Research Space (South Africa)

    Singh, A

    2006-07-01

    Full Text Available simulator Slide 4 © CSIR 2006 www.csir.co.za ۞ Benefits of natural sunlight ۞ Restrictions of lifestyles ۞ Common misconceptions ۞ Experimental setups Slide 5 © CSIR 2006 www.csir.co.za Cancer Males... Females Cases Deaths Cases Deaths Oral cavity 175,916 80,736 98,373 46,723 Esophagus 315,394 261,162 146,723 124,730 Stomach 603,419 446,052 330,518 254,297 Colon/rectum 550,465 278,446 472,687 250,532 Liver 442,119 416,882 184...

  20. Sunlight effects on the 3D polar current system determined from low Earth orbit measurements

    DEFF Research Database (Denmark)

    Laundal, Karl M.; Finlay, Chris; Olsen, Nils

    2016-01-01

    analyzed together. In this paper, we present estimates of the average global Birkeland currents and horizontal ionospheric currents from the same set of magnetic field measurements. The magnetic field measurements, from the low Earth orbiting Swarm and CHAMP satellites, are used to co-estimate poloidal...... show that the Birkeland currents vary with the conductivity, which depends most strongly on solar EUV emissions on the dayside and on particle precipitation at pre-midnight magnetic local times. In sunlight, the horizontal equivalent current flows in two cells, resembling an opposite ionospheric...

  1. Effect of sunlight irradiation on photocatalytic pyrene degradation in contaminated soils by micro-nano size TiO2.

    Science.gov (United States)

    Chang Chien, S W; Chang, C H; Chen, S H; Wang, M C; Madhava Rao, M; Satya Veni, S

    2011-09-01

    The enhanced catalytic pyrene degradation in quartz sand and alluvial and red soils by micro-nano size TiO(2) in the presence and absence of sunlight was investigated. The results showed that the synergistic effect of sunlight irradiation and TiO(2) was more efficient on pyrene degradation in quartz sand and red and alluvial soils than the corresponding reaction system without sunlight irradiation. In the presence of sunlight irradiation, the photooxidation (without TiO(2)) of pyrene was very pronounced in alluvial and red soils and especially in quartz sand. However, in the absence of sunlight irradiation, the catalytic pyrene degradation by TiO(2) and the photooxidation (without TiO(2)) of pyrene were almost nil. This implicates that ultra-violet (UV) wavelength range of sunlight plays an important role in TiO(2)-enhanced photocatalytic pyrene degradation and in photooxidation (without TiO(2)) of pyrene. The percentages of photocatalytic pyrene degradation by TiO(2) in quartz sand, alluvial and red soils under sunlight irradiation were 78.3, 23.4, and 31.8%, respectively, at 5h reaction period with a 5% (w/w) dose of the amended catalyst. The sequence of TiO(2)-enhanced catalytic pyrene degradation in quartz sand and alluvial and red soils was quartz sand>red soil>alluvial soil, due to different texture and total organic carbon (TOC) contents of the quartz sand and other two soils. The differential Fourier transform infrared (FT-IR) spectra of degraded pyrene in alluvial soil corroborate that TiO(2)-enhanced photocatalytic degradation rate of degraded pyrene was much greater than photooxidation (without TiO(2)) rate of degraded pyrene. Based on the data obtained, the importance for the application of TiO(2)-enhanced photocatalytic pyrene degradation and associated organic contaminants in contaminated soils was elucidated.

  2. Mutation spectrum in sunlight-exposed mouse skin epidermis: small but appreciable contribution of oxidative stress-mediated mutagenesis

    Energy Technology Data Exchange (ETDEWEB)

    Ikehata, Hironobu [Department of Cell Biology, Graduate School of Medicine, Tohoku University, Sendai 980-8575 (Japan)]. E-mail: ikehata@mail.tains.tohoku.ac.jp; Nakamura, Shingo [Department of Cell Biology, Graduate School of Medicine, Tohoku University, Sendai 980-8575 (Japan); Department of Radiobiology, Institute for Environmental Sciences, Aomori 039-3212 (Japan); Asamura, Takaaki [Department of Cell Biology, Graduate School of Medicine, Tohoku University, Sendai 980-8575 (Japan); Ono, Tetsuya [Department of Cell Biology, Graduate School of Medicine, Tohoku University, Sendai 980-8575 (Japan)

    2004-11-22

    We studied the mutations induced in skin by sunlight using transgenic Muta{sup TM} mice. Noon sunlight during summer at Sendai, Japan induced mutations efficiently in both epidermis and dermis. The mutant frequency (MF) in epidermis reached nearly 0.5% during the first 40 min irradiation but became saturated at this level with the appearance of skin inflammation after further irradiation. At the equivalent inflammatory dose, sunlight was twice as genotoxic as 313 nm-peak UVB. The 81 mutations detected in 80 lacZ transgene mutants isolated from the sunlight-exposed epidermis were dominated by C {yields} T transitions (89%), occurring exclusively at dipyrimidine sites, and also included a CC {yields} TT tandem substitution. Thus, the sunlight-induced mutation spectrum is highly UV-specific, quite similar to that induced by UVB but significantly different from that induced by UVA. Although oxidative damage-related C {yields} A transversions were detected only in five mutants (6%), their frequency was elevated to at least 15 times the background level, suggesting that the contribution of UVA-mediated oxidative stress is comparatively small but considerable. An analysis of bases adjacent to the mutated cytosines revealed that the sunlight-induced mutations prefer 5'-TC-3' dipyrimidine sites to 5'-CC-3' and 5'-CT-3'. The distribution of the frequent C {yields} T transition sites in the transgene was well associated with the CpG motif, which is known to be completely methylated in the gene, and quite similar to that induced by UVB rather than that by UVA. Thus, the UVB component contributes to the sunlight-induced mutations in the mammalian skin much more than the UVA component, whose influence through reactive oxygen species (ROS)-mediated mutagenesis is still appreciable.

  3. Uranium Industry Annual, 1992

    Energy Technology Data Exchange (ETDEWEB)

    1993-10-28

    The Uranium Industry Annual provides current statistical data on the US uranium industry for the Congress, Federal and State agencies, the uranium and electric utility industries, and the public. The feature article, ``Decommissioning of US Conventional Uranium Production Centers,`` is included. Data on uranium raw materials activities including exploration activities and expenditures, resources and reserves, mine production of uranium, production of uranium concentrate, and industry employment are presented in Chapter 1. Data on uranium marketing activities including domestic uranium purchases, commitments by utilities, procurement arrangements, uranium imports under purchase contracts and exports, deliveries to enrichment suppliers, inventories, secondary market activities, utility market requirements, and uranium for sale by domestic suppliers are presented in Chapter 2.

  4. Uranium industry annual 1996

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-04-01

    The Uranium Industry Annual 1996 (UIA 1996) provides current statistical data on the US uranium industry`s activities relating to uranium raw materials and uranium marketing. The UIA 1996 is prepared for use by the Congress, Federal and State agencies, the uranium and nuclear electric utility industries, and the public. Data on uranium raw materials activities for 1987 through 1996 including exploration activities and expenditures, EIA-estimated reserves, mine production of uranium, production of uranium concentrate, and industry employment are presented in Chapter 1. Data on uranium marketing activities for 1994 through 2006, including purchases of uranium and enrichment services, enrichment feed deliveries, uranium fuel assemblies, filled and unfilled market requirements, uranium imports and exports, and uranium inventories are shown in Chapter 2. A feature article, The Role of Thorium in Nuclear Energy, is included. 24 figs., 56 tabs.

  5. Sunlight exposure and sun sensitivity associated with disability progression in multiple sclerosis.

    Science.gov (United States)

    D'hooghe, M B; Haentjens, P; Nagels, G; Garmyn, M; De Keyser, J

    2012-04-01

    Sunlight and vitamin D have been inversely associated with the risk of multiple sclerosis (MS). We investigated sunlight exposure and sun sensitivity in relation to disability progression in MS. We conducted a survey among persons with MS, registered by the Flemish MS society, Belgium, and stratified data according to relapsing-onset and progressive-onset MS. We used Kaplan-Meier survival and Cox proportional hazard regression analyses with time to Expanded Disability Status Scale (EDSS) 6 as outcome measure. Hazard ratios for the time from onset and from birth were calculated for the potentially predictive variables, adjusting for age at onset, gender and immunomodulatory treatment. 704 (51.3%) of the 1372 respondents had reached EDSS 6. In relapsing-onset MS, respondents reporting equal or higher levels of sun exposure than persons of the same age in the last 10 years had a decreased risk of reaching EDSS 6. In progressive-onset MS, increased sun sensitivity was associated with an increased hazard of reaching EDSS 6. The association of higher sun exposure with a better outcome in relapsing-onset MS may be explained by either a protective effect or reverse causality. Mechanisms underlying sun sensitivity might influence progression in progressive-onset MS.

  6. Factors influencing adherence with therapeutic sunlight exposure in older people in intermediate care facilities.

    Science.gov (United States)

    Durvasula, Seeta; Sambrook, Philip N; Cameron, Ian D

    2012-01-01

    The purpose of this study was to investigate the factors influencing low adherence with therapeutic sunlight exposure in a randomized controlled trial conducted with older people living in intermediate care facilities. The study involved participants in the FREEDOM (Falls Risk Epidemiology: Effect of vitamin D on skeletal Outcomes and other Measures) study, a randomized controlled trial of therapeutic sun exposure to reduce falls in older people in intermediate care facilities. Semi-structured interviews were conducted with thirty participants in the FREEDOM trial, and with ten sunlight officers who were employed to facilitate the sun exposure. Two focus groups involving 10 participants in the FREEDOM trial were also held at the end of the intervention period. Common themes were derived from the interview and focus group transcripts. The study showed that the perceived health benefits did not influence adherence with the sun exposure. Factors such as socializing with others and being outdoors were more important in encouraging attendance. The main barriers to adherence included the perceived inflexibility and regimentation of daily attendance, clash with other activities, unsuitable timing and heat discomfort. This study showed that providing greater flexibility and autonomy to older people in how and when they receive sun exposure is likely to improve adherence. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  7. Low exposure to sunlight is a risk factor for Crohn's disease.

    Science.gov (United States)

    Nerich, V; Jantchou, P; Boutron-Ruault, M-C; Monnet, E; Weill, A; Vanbockstael, V; Auleley, G-R; Balaire, C; Dubost, P; Rican, S; Allemand, H; Carbonnel, F

    2011-04-01

    Low sunshine exposure might contribute to the pathogenesis of inflammatory bowel disease (IBD). To assess the geographic distribution of IBD incidence in relation to sunshine exposure in France to test the hypothesis that higher sun exposure is associated with lower IBD risk. Using the national health insurance database, incidence rates of Crohn's disease (CD) and ulcerative colitis (UC) were estimated for each of the 94 French administrative areas ('départements'), between 2000 and 2002. The surface UV radiation intensity was obtained by combining modelling and satellite data from Meteosat, the European meteorological satellite. Relationships between incidence rates and sun exposure were tested for significance by using a Poisson regression. We mapped smoothed relative risks (sRR) for CD and UC, using a Bayesian approach and adjusting for sun exposure, to search for geographical variations. Areas with a smoothed RR of CD incidence significantly above 1 corresponded to areas with low sunshine exposure, whereas those with high or medium sunlight exposure had smoothed RRs either lower than 1 or not significantly different from 1. There was no association between sun exposure and UC incidence. This geographic study suggests that low sunlight exposure is associated with an increased incidence of Crohn's disease. Further studies are needed to determine if this association is causal. © 2011 Blackwell Publishing Ltd.

  8. Years of sunlight exposure and cataract: a case-control study in a Mediterranean population

    Science.gov (United States)

    Pastor-Valero, María; Fletcher, Astrid E; de Stavola, Bianca L; Chaqués-Alepúz, Vicente

    2007-01-01

    Background We aimed to investigate the relation between sunlight exposure and risk of cataract. Methods We carried out a frequency-matched case-control study of 343 cases and 334 controls attending an ophthalmology outpatient clinic at a primary health-care center in a small town near Valencia, Spain. All cases were diagnosed as having a cataract in at least one eye based on the Lens Opacification Classification system (LOCS II). Controls had no opacities in either eye. All cases and controls were interviewed for information on outdoor exposure, "usual" diet, history of severe episodes of diarrhea illness, life-style factors and medical and socio-demographic variables. Blood antioxidant vitamin levels were also analyzed. We used logistic regression models to estimate sex and age-adjusted odds ratios (ORs) by quintiles of years of occupational outdoor exposure, adjusting for potential confounders such as smoking, alcohol consumption, serum antioxidants and education. Results No association was found between years of outdoor exposure and risk of cataract. However, exploratory analyses suggested a positive association between years of outdoor exposure at younger ages and risk of nuclear cataract later in life. Conclusion Our study does not support an association with cataract and sunlight exposure over adult life. PMID:18039367

  9. Sunlight triggers cutaneous lupus through a CSF-1-dependent mechanism in MRL-Fas(lpr) mice.

    Science.gov (United States)

    Menke, Julia; Hsu, Mei-Yu; Byrne, Katelyn T; Lucas, Julie A; Rabacal, Whitney A; Croker, Byron P; Zong, Xiao-Hua; Stanley, E Richard; Kelley, Vicki R

    2008-11-15

    Sunlight (UVB) triggers cutaneous lupus erythematosus (CLE) and systemic lupus through an unknown mechanism. We tested the hypothesis that UVB triggers CLE through a CSF-1-dependent, macrophage (Mø)-mediated mechanism in MRL-Fas(lpr) mice. By constructing mutant MRL-Fas(lpr) strains expressing varying levels of CSF-1 (high, intermediate, none), and use of an ex vivo gene transfer to deliver CSF-1 intradermally, we determined that CSF-1 induces CLE in lupus-susceptible MRL-Fas(lpr) mice, but not in lupus-resistant BALB/c mice. UVB incites an increase in Møs, apoptosis in the skin, and CLE in MRL-Fas(lpr), but not in CSF-1-deficient MRL-Fas(lpr) mice. Furthermore, UVB did not induce CLE in BALB/c mice. Probing further, UVB stimulates CSF-1 expression by keratinocytes leading to recruitment and activation of Møs that, in turn, release mediators, which induce apoptosis in keratinocytes. Thus, sunlight triggers a CSF-1-dependent, Mø-mediated destructive inflammation in the skin leading to CLE in lupus-susceptible MRL-Fas(lpr) but not lupus-resistant BALB/c mice. Taken together, CSF-1 is envisioned as the match and lupus susceptibility as the tinder leading to CLE.

  10. Surface exposure to sunlight stimulates CO2 release from permafrost soil carbon in the Arctic.

    Science.gov (United States)

    Cory, Rose M; Crump, Byron C; Dobkowski, Jason A; Kling, George W

    2013-02-26

    Recent climate change has increased arctic soil temperatures and thawed large areas of permafrost, allowing for microbial respiration of previously frozen C. Furthermore, soil destabilization from melting ice has caused an increase in thermokarst failures that expose buried C and release dissolved organic C (DOC) to surface waters. Once exposed, the fate of this C is unknown but will depend on its reactivity to sunlight and microbial attack, and the light available at the surface. In this study we manipulated water released from areas of thermokarst activity to show that newly exposed DOC is >40% more susceptible to microbial conversion to CO(2) when exposed to UV light than when kept dark. When integrated over the water column of receiving rivers, this susceptibility translates to the light-stimulated bacterial activity being on average from 11% to 40% of the total areal activity in turbid versus DOC-colored rivers, respectively. The range of DOC lability to microbes seems to depend on prior light exposure, implying that sunlight may act as an amplification factor in the conversion of frozen C stores to C gases in the atmosphere.

  11. A full-sunlight-driven photocatalyst with super long-persistent energy storage ability.

    Science.gov (United States)

    Li, Jie; Liu, Yuan; Zhu, Zhijian; Zhang, Guozhu; Zou, Tao; Zou, Zhijun; Zhang, Shunping; Zeng, Dawen; Xie, Changsheng

    2013-01-01

    A major drawback of traditional photocatalysts like TiO2 is that they can only work under illumination, and the light has to be UV. As a solution for this limitation, visible-light-driven energy storage photocatalysts have been developed in recent years. However, energy storage photocatalysts that are full-sunlight-driven (UV-visible-NIR) and possess long-lasting energy storage ability are lacking. Here we report, a Pt-loaded and hydrogen-treated WO3 that exhibits a strong absorption at full-sunlight spectrum (300-1,000 nm), and with a super-long energy storage time of more than 300 h to have formaldehyde degraded in dark. In this new material system, the hydrogen treated WO3 functions as the light harvesting material and energy storage material simultaneously, while Pt mainly acts as the cocatalyst to have the energy storage effect displayed. The extraordinary full-spectrum absorption effect and long persistent energy storage ability make the material a potential solar-energy storage and an effective photocatalyst in practice.

  12. Years of sunlight exposure and cataract: a case-control study in a Mediterranean population

    Directory of Open Access Journals (Sweden)

    de Stavola Bianca L

    2007-11-01

    Full Text Available Abstract Background We aimed to investigate the relation between sunlight exposure and risk of cataract. Methods We carried out a frequency-matched case-control study of 343 cases and 334 controls attending an ophthalmology outpatient clinic at a primary health-care center in a small town near Valencia, Spain. All cases were diagnosed as having a cataract in at least one eye based on the Lens Opacification Classification system (LOCS II. Controls had no opacities in either eye. All cases and controls were interviewed for information on outdoor exposure, "usual" diet, history of severe episodes of diarrhea illness, life-style factors and medical and socio-demographic variables. Blood antioxidant vitamin levels were also analyzed. We used logistic regression models to estimate sex and age-adjusted odds ratios (ORs by quintiles of years of occupational outdoor exposure, adjusting for potential confounders such as smoking, alcohol consumption, serum antioxidants and education. Results No association was found between years of outdoor exposure and risk of cataract. However, exploratory analyses suggested a positive association between years of outdoor exposure at younger ages and risk of nuclear cataract later in life. Conclusion Our study does not support an association with cataract and sunlight exposure over adult life.

  13. Chloroplast avoidance movement is not functional in plants grown under strong sunlight.

    Science.gov (United States)

    Higa, Takeshi; Wada, Masamitsu

    2016-04-01

    Chloroplast movement in nine climbing plant species was investigated. It is thought that chloroplasts generally escape from strong light to avoid photodamage but accumulate towards weak light to perform photosynthesis effectively. Unexpectedly, however, the leaves of climbing plants grown under strong sunlight showed very low or no chloroplast photorelocation responses to either weak or strong blue light when detected by red light transmittance through leaves. Direct observations of Cayratia japonica leaves, for example, revealed that the average number of chloroplasts in upper periclinal walls of palisade tissue cells was only 1.2 after weak blue-light irradiation and almost all of the chloroplasts remained at the anticlinal wall, the state of chloroplast avoidance response. The leaves grown under strong light have thin and columnar palisade tissue cells comparing with the leaves grown under low light. Depending on our analyses and our schematic model, the thinner cells in a unit leaf area have a wider total plasma membrane area, such that more chloroplasts can exist on the plasma membrane in the thinner cells than in the thicker cells in a unit leaf-area basis. The same strategy might be used in other plant leaves grown under direct sunlight.

  14. Improving the sunlight-to-biomass conversion efficiency in microalgal biofactories.

    Science.gov (United States)

    Wobbe, Lutz; Remacle, Claire

    2015-05-10

    Microalgae represent promising organisms for the sustainable production of commodities, chemicals or fuels. Future use of such systems, however, requires increased productivity of microalgal mass cultures in order to reach an economic viability for microalgae-based production schemes. The efficiency of sunlight-to-biomass conversion that can be observed in bulk cultures is generally far lower (35-80%) than the theoretical maximum, because energy losses occur at multiple steps during the light-driven conversion of carbon dioxide to organic carbon. The light-harvesting system is a major source of energy losses and thus a prime target for strain engineering. Truncation of the light-harvesting antenna in the algal model organism Chlamydomonas reinhardtii was shown to be an effective way of increasing culture productivity at least under saturating light conditions. Furthermore engineering of the Calvin-Benson cycle or the creation of photorespiratory bypasses in A. thaliana proved to be successful in terms of achieving higher biomass productivities. An efficient generation of novel microalgal strains with improved sunlight conversion efficiencies by targeted engineering in the future will require an expanded molecular toolkit. In the meantime random mutagenesis coupled to high-throughput screening for desired phenotypes can be used to provide engineered microalgae. Copyright © 2014 Elsevier B.V. All rights reserved.

  15. How long can culturable bacteria and total DNA persist in environmental waters? The role of sunlight and solid particles.

    Science.gov (United States)

    Gutiérrez-Cacciabue, Dolores; Cid, Alicia G; Rajal, Verónica B

    2016-01-01

    In this work, sunlight inactivation of two indicator bacteria in freshwater, with and without solid particles, was studied and the persistence of culturable cells and total DNA was compared. Environmental water was used to prepare two matrices, with and without solid particles, which were spiked with Escherichia coli and Enterococcus faecalis. These matrices were used to prepare microcosm bags that were placed in two containers: one exposed to sunlight and the other in the dark. During one month, samples were removed from each container and detection was done by membrane filter technique and real-time PCR. Kinetic parameters were calculated to assess sunlight effect. Indicator bacteria without solid particles exposed to sunlight suffered an immediate decay (solid particles varied depending on the situation analyzed (T99 from 3 up to 60days), being always culturable E. coli more persistent than E. faecalis. On the other side, E. faecalis DNA persisted much longer than culturable cells (T99>40h in the dark with particles). In this case active cells were more prone to sunlight than total DNA and the protective effect of solid particles was also observed. Results highlight that the effects caused by the parameters which describe the behavior of culturable microorganisms and total DNA in water are different and must be included in simulation models but without forgetting that these parameters will also depend on bacterial properties, sensitizers, composition, type, and uses of the aquatic environment under assessment.

  16. Quantification of ultraviolet radiation-induced DNA damage in the urine of Swedish adults and children following exposure to sunlight.

    Science.gov (United States)

    Liljendahl, Tove Sandberg; Kotova, Natalia; Segerbäck, Dan

    2012-11-01

    DNA damage following exposure to ultraviolet radiation (UVR) is important in skin cancer development. The predominant photoproduct, cyclobutane thymine dimer (T=T), is repaired and excreted in the urine, where it provides a biomarker of exposure. To quantify urinary T=T levels after recreational sunlight exposure in adults and children. Average UVR doses were measured with personal dosimeters. Urinary T=T was analysed with (32)P-postlabelling. Background levels of T=T increased significantly following exposure to sunlight. Amounts of T=T in urine of children and adults were not significantly different after adjusting for area of skin exposed and physiological differences. UVR dose and amounts of T=T correlated for both adults and children. Recreational exposure to sunlight in Sweden induces levels of DNA damage, clearly detectable in urine.

  17. Photocatalytic Synthesis of Phenol by Direct Hydroxylation of Benzene by a Modified Nanoporous Silica (LUS-1) under Sunlight

    Institute of Scientific and Technical Information of China (English)

    Ghasem SHIRAVAND; Alireza BADIEI; Ghodsi Mohammadi ZIARANI; Morteza JAFARABADI; Majid HAMZEHLOO

    2012-01-01

    Fe-g-C3N4-LUS-1was prepared by the thermal decomposition of dicyandiamide inside the pores of LUS-1under an inert atmosphere.It was used as a photocatalyst for the hydroxylation of benzene to phenol in sunlight.The catalysts were characterized by Fourier transform infrared spectroscopy,N2 adsorption-desorption,X-ray diffraction,and scanning electron microscopy.In Fe-g-C3N4-LUS-1,a single layer of graphitic carbon nitride (g-C3N4) was formed on the surface of LUS-1.The photocatalytic activity of the iron containing g-C3N4based catalysts was investigated,and the catalytic activity was remarkably enhanced when the reaction condition was changed from dark to sunlight.The best result was obtained with 20%Fe-g-C3N4-LUS-1 in sunlight.

  18. Roadmaps for powering the world, U.S., and individual states for all purposes with wind, water, and sunlight (Invited)

    Science.gov (United States)

    Jacobson, M. Z.

    2013-12-01

    Global warming, air pollution, and energy insecurity are three of the most significant problems facing the world today. This talk discusses these problems and technical and economic plans to solve them by powering 100% of the world, individual countries, and states for all purposes, including electricity, transportation, industry, and heating/cooling, with wind, water, and sunlight (WWS) together with efficiency measures, within 20-40 years. Specific plans for New York State and California are discussed. For California, the plan contemplates all new energy powered with WWS by 2020, 80-85% of existing energy replaced by 2030, and 100% replaced by 2050. Electrification plus modest efficiency measures would reduce California's end-use power demand ~44% and stabilize energy prices since WWS fuel costs are zero. Even without additional efficiency improvements, remaining all-purpose 2030 end-use demand could be met with 25% onshore and 10% offshore wind, 15% concentrated solar, 15% utility-scale PV, 10% residential PV, 15% commercial/government PV, 5% geothermal, 0.5% wave, 0.5% tidal, and 4% hydroelectric. These percentages will shift upon implementation. Converting would create ~137,000 net permanent jobs, decrease ~16,000 (4,800-29,600) state air pollution deaths/yr, and avoid 131 (39-296) billion/yr in health costs (6.9% of California's 2010 gross domestic product), repaying the 1 trillion capital cost for 573 GW installed power within ~7.3 yr. California's emission decreases would reduce 2050 U.S. and global climate costs by ~6 and 60 billion/yr, respectively.

  19. Sandia concentrator array testing experiences

    Science.gov (United States)

    Gerwin, H. J.; Rogers, C. B.; Beavis, L. C.

    An assortment of PV concentrator modules and arrays have been tested and evaluated at the Sandia outdoor test facility. These test items include actively-cooled parabolic reflector and linear Fresnel lens concentrators, and actively- and passively-cooled point focus collectors. Maximum power efficiencies were measured over a range of sunlight intensities and cell temperatures, then a linear equation relating efficiency to cell temperature and insolation was developed for each module and array by using a multiple linear regression analysis technique on the data. An evaluation of the suitability of Polyvinyl-Butyral (PVB) as a material used to laminate solar cells to glass is presented. Some general observations are made on the accuracy of tracking systems, and the maintenance of these systems.

  20. Nanocrystals for luminescent solar concentrators.

    Science.gov (United States)

    Bradshaw, Liam R; Knowles, Kathryn E; McDowall, Stephen; Gamelin, Daniel R

    2015-02-11

    Luminescent solar concentrators (LSCs) harvest sunlight over large areas and concentrate this energy onto photovoltaics or for other uses by transporting photons through macroscopic waveguides. Although attractive for lowering solar energy costs, LSCs remain severely limited by luminophore reabsorption losses. Here, we report a quantitative comparison of four types of nanocrystal (NC) phosphors recently proposed to minimize reabsorption in large-scale LSCs: two nanocrystal heterostructures and two doped nanocrystals. Experimental and numerical analyses both show that even the small core absorption of the leading NC heterostructures causes major reabsorption losses at relatively short transport lengths. Doped NCs outperform the heterostructures substantially in this critical property. A new LSC phosphor is introduced, nanocrystalline Cd(1-x)Cu(x)Se, that outperforms all other leading NCs by a significant margin in both small- and large-scale LSCs under full-spectrum conditions.

  1. Concentrating Solar Power Fact Sheet

    Energy Technology Data Exchange (ETDEWEB)

    None

    2015-12-01

    This fact sheet is an overview of the Concentrating Solar Power (CSP) subprogram at the U.S. Department of Energy SunShot Initiative. CSP is a dispatchable, renewable energy option that uses mirrors to focus and concentrate sunlight onto a receiver, from which a heat transfer fluid carries the intense thermal energy to a power block to generate electricity. CSP systems can store solar energy to be used when the sun is not shining. It will help meet the nation’s goal of making solar energy fully cost-competitive with other energy sources by the end of the decade. Worldwide, CSP activity is rapidly scaling, with approximately 10 gigawatts (GW) in various stages of operation or development. In the United States alone, nearly 2 GW of CSP are in operation.

  2. Associations of Blood Pressure, Sunlight, and Vitamin D in Community-Dwelling Adults: The Reasons for Geographic and Racial Differences in Stroke (Regards) Study

    Science.gov (United States)

    Rostand MD, Stephen G.; Mcclure, Leslie A.; Kent, Shia T.; Judd, Suzanne E.; Gutiérrez MD, Orlando M.

    2017-01-01

    Background Vitamin D deficiency/insufficiency is associated with hypertension. Blood pressure and circulating vitamin D concentrations vary with the seasons and distance from the equator suggesting blood pressure varies inversely with the sunshine available (insolation) for cutaneous vitamin D photosynthesis. Methods To determine if the association between insolation and blood pressure is partly explained by vitamin D we evaluated 1104 participants in the Reasons for Racial and Geographic Differences in Stroke (REGARDS) study whose blood pressure and plasma 25-hydroxyvitamin D (25(OH)D) concentrations were measured. Results We found a significant inverse association between systolic blood pressure (SBP) and 25(OH)D concentration and an inverse association between insolation and blood pressure in unadjusted analyses. After adjusting for other confounding variables, the association of solar insolation and blood pressure was augmented,-0.3.5±SE 0.01 mmHg/1SD higher solar insolation, p=0.01. We found the greatest of effects of insolation on SBP were observed in whites (-5.2±SE O.92 mmHg/1SD higher solar insolation, p=0.005) and in women (-3.8±SE 1.7 mmHg, p=0.024). We found that adjusting for 25(OH)D had no effect on the association of solar insolation with SBP. Conclusions We conclude that although 25(OH)D concentration is inversely associated with SBP, 25(OH)D it did not explain the association of greater sunlight exposure with lower blood pressure. Condensed Abstract To determine if the inverse association between solar insolation and blood pressure is partly explained by vitamin D we evaluated 1104 participants in the Reasons for Racial and Geographic Differences in Stroke (REGARDS) study whose blood pressure and plasma 25-hydroxyvitamin D (25(OH)D) concentrations were measured. We found that 25(OH)D concentration varied inversely with SBP and SBP varied inversely with solar insolation but we found that adjusting for 25(OH)D had no effect on the association of

  3. Preparation of K-doped TiO2 nanostructures by wet corrosion and their sunlight-driven photocatalytic performance

    Science.gov (United States)

    Shin, Eunhye; Jin, Saera; Kim, Jiyoon; Chang, Sung-Jin; Jun, Byung-Hyuk; Park, Kwang-Won; Hong, Jongin

    2016-08-01

    K-doped TiO2 nanowire networks were prepared by the corrosion reaction of Ti nanoparticles in an alkaline (potassium hydroxide: KOH) solution. The prepared nanostructures were characterized by scanning electron microscopy (SEM), Brunauer-Emmett-Teller (BET) analysis, X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, X-ray diffraction (XRD) and photoluminescence (PL) spectra. Their sunlight-driven photocatalytic activity was also investigated with differently charged dye molecules, such as methylene blue, rhodamine B and methyl orange. The adsorption of the dye molecules on the photocatalyst surface would play a critical role in their selective photodegradation under sunlight illumination.

  4. Iron (III) aquacomplexes as catalysts for pesticides mineralisation by sunlight irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Catastini, C.; Mailhot, G.; Malato, S.; Sarakha, M.

    2002-07-01

    The experimental results of the photo catalytic degradation of the pesticide asulam (4-amino-benzosulfonyl-methylcarbamate) in aqueous solutions using iron (III) aquacomplexes as photo inducer and sunlight as irradiation source are reported. The experiments were conducted in a compound parabolic collector reactor (CPC) of Plataforma solar de Almeria. In the early stages of the irradiation, the degradation is clearly due to the photo redox process involving the most photoactive species of iron (III) (Fe(OH)''2+). The degradation was also shown to proceed when iron (II) was used as a photo inducer in aerated aqueous solutions. In both cases, the complete degradation of the substrate to CO{sub 2} in aerated aqueous solutions needed exposition to solar light of about 13-14 hours. A catalytic process involving iron (III), iron (II), oxygen and light is proposed. (Author) 24 refs.

  5. Design and fabrication of light-guiding plate for a photobioreactor that utilizes sunlight

    Science.gov (United States)

    Lim, Hyon-Chol; Kim, Hun; Jang, Kyungmin; Kim, Jae-Young; Baek, Joon-Hyuck; Yang, Seung-Jin; Jeong, Sang-Hwa; Park, Jong-Rak

    2015-10-01

    We present the results of the optical design and fabrication of a light-guiding plate (LGP) that utilizes sunlight to be adopted as an illumination system for photobioreactors. A solar daylighting system was employed as the light source for the LGP. We modeled the light sources (optical fiber exit ports of the solar daylighting system), a reflection film, and LGP patterns. An LGP (1000 mm × 500 mm × 10 mm) was designed and fabricated using a computerized numerical control machine. It was optimized for the average deviation of the illuminance distribution by varying the maximum pattern spacing, minimum pattern spacing, and spacing constant of the pattern spacing function expressed in the form of an exponential function. Average illuminance and uniformity of the illuminance distribution of the fabricated LGP were measured to be 8174 lx (photon flux density: 122.0 μΕ m-2 s-1) and 90.0 %, respectively.

  6. Graphene-SnO2 composites for highly efficient photocatalytic degradation of methylene blue under sunlight.

    Science.gov (United States)

    Seema, Humaira; Christian Kemp, K; Chandra, Vimlesh; Kim, Kwang S

    2012-09-07

    Graphene sheets decorated with SnO(2) nanoparticles (RGO-SnO(2)) were prepared via a redox reaction between graphene oxide (GO) and SnCl(2). Graphene oxide (GO) was reduced to graphene (RGO) and Sn(2+) was oxidized to SnO(2) during the redox reaction, leading to a homogeneous distribution of SnO(2) nanoparticles on RGO sheets. The scanning electron microscopy (SEM) and transmission electron microscopy (TEM) images show uniform distribution of the nanoparticles on the RGO surface and high-resolution transmission electron microscopy (HRTEM) shows an average particle size of 3-5 nm. The RGO-SnO(2) composite showed an enhanced photocatalytic degradation activity for the organic dye methylene blue under sunlight compared to bare SnO(2) nanoparticles. This result leads us to believe that the RGO-SnO(2) composite could be used in catalytic photodegradation of other organic dyes.

  7. Natural sunlight irradiated flower-like CuS synthesized from DMF solvothermal treatment

    Science.gov (United States)

    Zhao, Wei; Wang, Zihao; Zhou, Lei; Liu, Nianqi; Wang, Hongxing

    2016-09-01

    Three-dimensional CuS hierarchical crystals with high catalytic activity had been successfully fabricated using a facile solvothermal process. The CuS microparticles showed different flower-like morphology and good dispersion by optimizing reaction conditions. It was found that using N,N-dimethylformamide (DMF) as the solvent reagent in the proper temperature conditions was favorable for the growth of hierarchically structured CuS. The hexagonal flower-like CuS synthesized at 170°C for 60 min displayed broad-spectrum photocatalytic properties under ultraviolet (UV) and visible irradiation. The as-prepared CuS crystals exhibited good performance to decolorize methylene blue (MB) solution under visible light irradiation. The total organic carbon (TOC) removal of rhodamine B (RhB) solution was nearly 60% after 5 h of the natural sunlight irradiation, and the property was stable after testing over four recycles, demonstrating a potential application in waster water treatment.

  8. Assessment of oxidative deterioration of soybean oil at ambient and sunlight storage

    Directory of Open Access Journals (Sweden)

    Ijaz Hussain, Abdullah

    2007-12-01

    Full Text Available This study was carried out in order to probe the extent of oxidative alterations in soybean oil (SBO, subjected to ambient and sunlight storage, over a period of 180 days. The magnitude of oxidative changes was monitored by the periodical measurement of peroxide value (PV, color, free fatty acid (FFA contents, refractive index (RI, p-anisidine-, conjugated dienes-, conjugated trienes-, and iodine- values. At the end of storage period (180 days, the initial contents of FFA (0.02 % as oleic acid and PV (0.02 meq/kg of oil of the SBO samples subjected to ambient and sunlight storage reached the level of 1.77, 2.90 % and 20.52, 41.89 meq/kg of oil, respectively. The initial values of RI (40°C (1.4630, panisidine (1.10, conjugated dienes (0.08 and conjugated trienes (0.04 rose to the point of 1.4647, 1.4659; 36.13, 50.40; 23.97, 41.49 and 13.81, 19.35, respectively. Whereas, the iodine value (g of I /100 g of oil decreased from 138.00 to 126.18 and 118.04, respectively. At the end of storage period, the overall order, indicative of the oxidative changes in RI, FFA, IV, color (red + yellow, PV, P-anisidine, conjugated dienes and conjugated trienes of the SBO subjected to ambient and sunlight storage was as follows: 1.001:1.002, 1.00:1.65, 0.91:0.86, 0.80:0.60 + 0.75:0.50, 1.00:2.04, 1.00:1.39, 1.00:1.73 and 1.00:1.40, respectively. The results of various parameters investigated in the present study demonstrated the magnitude of oxidative deterioration of the SBO samples exposed to sunlight to be significantly (P Se lleva a cabo un estudio para conocer las diferencias en la oxidación del aceite de soja conservado a temperatura ambiente y a la luz solar durante un periodo de 180 días. Los cambios en la oxidación fueron evaluados mediante medidas periódicas del índice de peroxidos, color, acidez libre, índice de refracción (RI, índice de p-anisidina, dienos conjugados e índice de yodo. Al final del periodo de almacenamiento, los niveles de

  9. Sunlight effects on the 3D polar current system determined from low Earth orbit measurements

    CERN Document Server

    Laundal, Karl M; Olsen, Nils

    2016-01-01

    Interaction between the solar wind and the Earth's magnetosphere is associated with large-scale currents in the ionosphere at polar latitudes that flow along magnetic field lines (Birkeland currents) and horizontally. These current systems are tightly linked, but their global behaviors are rarely analyzed together. In this paper, we present estimates of the average global Birkeland currents and horizontal ionospheric currents from the same set of magnetic field measurements. The magnetic field measurements, from the low Earth orbiting $\\textit{Swarm}$ and CHAMP satellites, are used to co-estimate poloidal and toroidal parts of the magnetic disturbance field, represented in magnetic apex coordinates. The use of apex coordinates reduces effects of longitudinal and hemispheric variations in the Earth's main field. We present global currents from both hemispheres during different sunlight conditions. The results show that the Birkeland currents vary with the conductivity, which depends most strongly on solar EUV ...

  10. Sunlight driven photocatalytic water splitting using nanostructured bismuth tungstate (Bi2WO6)

    Science.gov (United States)

    Radha, R.; Sakar, M.; Bharathkumar, S.; Balakumar, S.

    2017-05-01

    Sunlight driven photocatalytic water splitting properties of nanosized Bi2WO6 have been demonstrated. Upon the structural confirmation using XRD and Raman studies, the band edge offset deduced from UV-DRS spectra showed that the energy band structure of Bi2WO6 is manifested due to electronic transition in the hybridized orbital of Bi6s and O2p to the W5d orbital. The observed Bi2WO6 nanoparticulates-assisted H2 generation from glycerol-water mixture may be attributed to the following two competitive phenomena: (i) the photocatalytic degradation of glycerol and (ii) photocatalytic splitting of water molecules, where glycerol acts as a sacrificial agent. This study sheds lights on the photocatalytic reformation of contaminated aqueous ecosystems as a green resource to produce hydrogen energy.

  11. Retrieval of stratospheric aerosol size information from OSIRIS limb scattered sunlight spectra

    Directory of Open Access Journals (Sweden)

    A. E. Bourassa

    2008-02-01

    Full Text Available Recent work has shown that the retrieval of stratospheric aerosol vertical profiles is possible using limb scattered sunlight measurements at optical wavelengths. The aerosol number density profile is retrieved for an assumed particle size distribution and composition. This result can be used to derive the extinction at the measured wavelength. However, large systematic error can result from the uncertainty in the assumed size distribution when the result is used to estimate the extinction at other wavelengths. It is shown in this work that the addition of information obtained from the near infrared limb radiance profile at 1530 nm measured by the imaging module of the OSIRIS instrument yields an indication of the aerosol size distribution profile that can be used to improve the fidelity of the retrievals. A comparison of the estimated extinction profile at 1020 nm with coincident occultation measurements demonstrates agreement to within approximately 15% from 12 to 27 km altitude.

  12. 50 kWp Photovoltaic Concentrator Application Experiment, Phase I. Final report, 1 June 1978-28 February 1979

    Energy Technology Data Exchange (ETDEWEB)

    Maget, H.J.R.

    1979-06-15

    This program consists of a design study and component development for an experimental 50-kWp photovoltaic concentrator system to supply power to the San Ramon substation of the Pacific Gas and Electric Company. The photovoltaic system is optimized to produce peaking power to relieve the air conditioning load on the PG and E system during summer afternoons; and would therefore displace oil-fired power generation capacity. No electrical storage is required. The experiment would use GaAs concentrator cells with point-focus fresnel lenses operating at 400X, in independent tracking arrays of 440 cells each, generating 3.8 kWp. Fourteen arrays, each 9 feet by 33 feet, are connected electrically in series to generate the 50 kWp. The high conversion efficiency possible with GaAs concentrator cells results in a projected annual average system efficiency (AC electric power output to sunlight input) of better than 15%. The capability of GaAs cells for high temperature operation made possible the design of a total energy option, whereby thermal power from selected arrays could be used to heat and cool the control center for the installation. System design and analysis, fabrication and installation, environmental assessment, and cost projections are described in detail. (WHK)

  13. Analysis of Environmental Effects on Leaf Temperature under Sunlight, High Pressure Sodium and Light Emitting Diodes.

    Directory of Open Access Journals (Sweden)

    Jacob A Nelson

    Full Text Available The use of LED technology is commonly assumed to result in significantly cooler leaf temperatures than high pressure sodium technology. To evaluate the magnitude of this effect, we measured radiation incident to and absorbed by a leaf under four radiation sources: clear sky sunlight in the field, sunlight in a glass greenhouse, and indoor plants under either high pressure sodium or light emitting diodes. We then applied a common mechanistic energy-balance model to compare leaf to air temperature difference among the radiation sources and environments. At equal photosynthetic photon flux, our results indicate that the effect of plant water status and leaf evaporative cooling is much larger than the effect of radiation source. If plants are not water stressed, leaves in all four radiation sources were typically within 2°C of air temperature. Under clear sky conditions, cool sky temperatures mean that leaves in the field are always cooler than greenhouse or indoor plants-when photosynthetic photon flux, stomatal conductance, wind speed, vapor pressure deficit, and leaf size are equivalent. As water stress increases and cooling via transpiration decreases, leaf temperatures can increase well above air temperature. In a near-worst case scenario of water stress and low wind, our model indicates that leaves would increase 6°, 8°, 10°, and 12°C above air temperature under field, LED, greenhouse, and HPS scenarios, respectively. Because LED fixtures emit much of their heat through convection rather than radiative cooling, they result in slightly cooler leaf temperatures than leaves in greenhouses and under HPS fixtures, but the effect of LED technology on leaf temperature is smaller than is often assumed. Quantifying the thermodynamic outputs of these lamps, and their physiological consequences, will allow both researchers and the horticulture industry to make informed decisions when employing these technologies.

  14. The relationship between long-term sunlight radiation and cognitive decline in the REGARDS cohort study

    Science.gov (United States)

    Kent, Shia T.; Kabagambe, Edmond K.; Wadley, Virginia G.; Howard, Virginia J.; Crosson, William L.; Al-Hamdan, Mohammad Z.; Judd, Suzanne E.; Peace, Fredrick; McClure, Leslie A.

    2014-04-01

    Sunlight may be related to cognitive function through vitamin D metabolism or circadian rhythm regulation. The analysis presented here sought to test whether ground and satellite measures of solar radiation are associated with cognitive decline. The study used a 15-year residential history merged with satellite and ground monitor data to determine sunlight (solar radiation) and air temperature exposure for a cohort of 19,896 cognitively intact black and white participants aged 45+ from the 48 contiguous United States. Exposures of 15, 10, 5, 2, and 1-year were used to predict cognitive status at the most recent assessment in logistic regression models; 1-year insolation and maximum temperatures were chosen as exposure measures. Solar radiation interacted with temperature, age, and gender in its relationships with incident cognitive impairment. After adjustment for covariates, the odds ratio (OR) of cognitive decline for solar radiation exposure below the median vs above the median in the 3rd tertile of maximum temperatures was 1.88 (95 % CI: 1.24, 2.85), that in the 2nd tertile was 1.33 (95 % CI: 1.09, 1.62), and that in the 1st tertile was 1.22 (95 % CI: 0.92, 1.60). We also found that participants under 60 years old had an OR = 1.63 (95 % CI: 1.20, 2.22), those 60-80 years old had an OR = 1.18 (95 % CI: 1.02, 1.36), and those over 80 years old had an OR = 1.05 (0.80, 1.37). Lastly, we found that males had an OR = 1.43 (95 % CI: 1.22, 1.69), and females had an OR = 1.02 (0.87, 1.20). We found that lower levels of solar radiation were associated with increased odds of incident cognitive impairment.

  15. The effect of sunlight exposure on interleukin-6 levels in depressive and non-depressive subjects.

    Science.gov (United States)

    Levandovski, Rosa; Pfaffenseller, Bianca; Carissimi, Alicia; Gama, Clarissa S; Hidalgo, Maria Paz Loayza

    2013-03-05

    The objective of this epidemiological study was to evaluate the effect of length of sunlight exposure on interleukin 6 (IL-6) levels in depressive and non-depressive subjects. This was a cross-sectional study with 154 subjects (54 males, mean age: 43.5 ± 12.8 years) who were living in a rural area in south Brazil. Chronobiological and light parameters were assessed using the Munich Chronotype Questionnaire. Sleep quality was evaluated using the Pittsburgh Sleep Quality Index. Depressive symptoms were assessed with the Beck Depression Inventory. Plasma levels of inflammatory cytokines (IL-2, IL-4, IL-6, IL-10, tumor necrosis factor-α, and interferon) were collected during the daytime and measured. IL-6 levels showed a positive correlation with light exposure (r = 0.257; p exposure was an independent factor for predicting IL-6 levels (ß = 0.26; p = 0.002). In non-depressed subjects, exposure to a different intensity of light did not affect IL-6 levels (t = -1.6; p = 0.1). However, when the two depressive groups with low and high light exposure were compared, the low light exposure group had lower levels of IL-6 compared with the high light exposure group (t = -2.19 and p = 0.0037). The amount of time that participants are exposed to sunlight is directly related to their IL-6 levels. Additionally, depressed subjects differ in their IL-6 levels if they are exposed to light for differing amounts of time.

  16. Sunlight-exposed biofilm microbial communities are naturally resistant to chernobyl ionizing-radiation levels.

    Science.gov (United States)

    Ragon, Marie; Restoux, Gwendal; Moreira, David; Møller, Anders Pape; López-García, Purificación

    2011-01-01

    The Chernobyl accident represents a long-term experiment on the effects of exposure to ionizing radiation at the ecosystem level. Though studies of these effects on plants and animals are abundant, the study of how Chernobyl radiation levels affect prokaryotic and eukaryotic microbial communities is practically non-existent, except for a few reports on human pathogens or soil microorganisms. Environments enduring extreme desiccation and UV radiation, such as sunlight exposed biofilms could in principle select for organisms highly resistant to ionizing radiation as well. To test this hypothesis, we explored the diversity of microorganisms belonging to the three domains of life by cultivation-independent approaches in biofilms developing on concrete walls or pillars in the Chernobyl area exposed to different levels of radiation, and we compared them with a similar biofilm from a non-irradiated site in Northern Ireland. Actinobacteria, Alphaproteobacteria, Bacteroidetes, Acidobacteria and Deinococcales were the most consistently detected bacterial groups, whereas green algae (Chlorophyta) and ascomycete fungi (Ascomycota) dominated within the eukaryotes. Close relatives to the most radio-resistant organisms known, including Rubrobacter species, Deinococcales and melanized ascomycete fungi were always detected. The diversity of bacteria and eukaryotes found in the most highly irradiated samples was comparable to that of less irradiated Chernobyl sites and Northern Ireland. However, the study of mutation frequencies in non-coding ITS regions versus SSU rRNA genes in members of a same actinobacterial operational taxonomic unit (OTU) present in Chernobyl samples and Northern Ireland showed a positive correlation between increased radiation and mutation rates. Our results show that biofilm microbial communities in the most irradiated samples are comparable to non-irradiated samples in terms of general diversity patterns, despite increased mutation levels at the single

  17. Sensitivity Studies for Space-based Measurement of Atmospheric Total Column Carbon Dioxide Using Reflected Sunlight

    Science.gov (United States)

    Mao, Jianping; Kawa, S. Randolph

    2003-01-01

    A series of sensitivity studies is carried out to explore the feasibility of space-based global carbon dioxide (CO2) measurements for global and regional carbon cycle studies. The detection method uses absorption of reflected sunlight in the CO2 vibration-rotation band at 1.58 microns. The sensitivities of the detected radiances are calculated using the line-by-line model (LBLRTM), implemented with the DISORT (Discrete Ordinates Radiative Transfer) model to include atmospheric scattering in this band. The results indicate that (a) the small (approx.1%) changes in CO2 near the Earth's surface are detectable in this CO2 band provided adequate sensor signal-to-noise ratio and spectral resolution are achievable; (b) the radiance signal or sensitivity to CO2 change near the surface is not significantly diminished even in the presence of aerosols and/or thin cirrus clouds in the atmosphere; (c) the modification of sunlight path length by scattering of aerosols and cirrus clouds could lead to large systematic errors in the retrieval; therefore, ancillary aerosol/cirrus cloud data are important to reduce retrieval errors; (d) CO2 retrieval requires good knowledge of the atmospheric temperature profile, e.g. approximately 1K RMS error in layer temperature; (e) the atmospheric path length, over which the CO2 absorption occurs, must be known in order to correctly interpret horizontal gradients of CO2 from the total column CO2 measurement; thus an additional sensor for surface pressure measurement needs to be attached for a complete measurement package.

  18. Mg-doped ZnO nanoparticles for efficient sunlight-driven photocatalysis.

    Science.gov (United States)

    Etacheri, Vinodkumar; Roshan, Roshith; Kumar, Vishwanathan

    2012-05-01

    Magnesium-doped ZnO (ZMO) nanoparticles were synthesized through an oxalate coprecipitation method. Crystallization of ZMO upon thermal decomposition of the oxalate precursors was investigated using differential scanning calorimetry (DSC) and X-ray diffraction (XRD) techniques. XRD studies point toward a significant c-axis compression and reduced crystallite sizes for ZMO samples in contrast to undoped ZnO, which was further confirmed by HRSEM studies. X-ray photoelectron spectroscopy (XPS), UV/vis spectroscopy and photoluminescence (PL) spectroscopy were employed to establish the electronic and optical properties of these nanoparticles. (XPS) studies confirmed the substitution of Zn(2+) by Mg(2+), crystallization of MgO secondary phase, and increased Zn-O bond strengths in Mg-doped ZnO samples. Textural properties of these ZMO samples obtained at various calcination temperatures were superior in comparison to the undoped ZnO. In addition to this, ZMO samples exhibited a blue-shift in the near band edge photoluminescence (PL) emission, decrease of PL intensities and superior sunlight-induced photocatalytic decomposition of methylene blue in contrast to undoped ZnO. The most active photocatalyst 0.1-MgZnO obtained after calcination at 600 °C showed a 2-fold increase in photocatalytic activity compared to the undoped ZnO. Band gap widening, superior textural properties and efficient electron-hole separation were identified as the factors responsible for the enhanced sunlight-driven photocatalytic activities of Mg-doped ZnO nanoparticles.

  19. Modeling of integrated sunlight velocity measurements: The effect of surface darkening by magnetic fields

    Science.gov (United States)

    Ulrich, R. K.; Henney, C. J.; Schimpf, S.; Fossat, E.; Gelly, B.; Grec, G.; Loudagh, S.; Schmider, F.-X; Palle, P.; Regulo, C.

    1993-01-01

    It has been known since the work by Claverie et al. (1982) that integrated-sunlight velocities measured with the resonance scattering technique show variations with time scales of weeks to months. The cause can be understood in terms of the effects of solar activity as was pointed out by Edmunds & Gough (1983) and Andersen & Maltby (1983). The latter authors included a model calculation based on sunspot areas which showed good promise of being able to quantitatively reproduce the observed velocity shifts. We discuss in this paper a new modeling effort based on daily magnetograms obtained at the 150-ft tower on Mt. Wilson. This type of database is more quantitative than sunspot area. Similar maps of magnetically sensitive quantities will be measured on a continuous time base as part of several planned helioseismology experiments (from space with the Solar Oscillations Imagery/Michelson Doppler Imager (SOI/MDI) experiment on the Solar and Heliospheric Observatory (SOHO), see Scherrer et al. (1991) or with ground-based networks, see Hill & Leibacher (1991)). We discuss the correlations between various magnetically sensitive quantities and develop a new model for the effects of magnetic field on line profiles and surface brightness. From these correlations we integrate the line profile changes over the solar surface using observed magnetic field strengths measured at lambda 5250.2. The final output is a new model for the effects of magnetic fields on integrated sunlight velocities which we compare with daily offset velocities derived from the International Research on the Interior of the Sun (IRIS)-T instrument at the Observatorio del Teide.

  20. Abiotic degradation of four phthalic acid esters in aqueous phase under natural sunlight irradiation

    Institute of Scientific and Technical Information of China (English)

    Ruttapol Lertsirisopon; Satoshi Soda; Kazunari Sei; Michihiko Ike

    2009-01-01

    Abiotic degradability of four phthalic acid esters (PAEs) in the aquatic phase was evaluated over the wide pH range (5-9). The PAE solutions in glass test tubes were placed in the dark and under natural sunlight irradiation for evaluating the degradation rate via hydrolysis and photolysis plus hydrolysis, respectively, at ambient temperature for 140 d from autumn to winter in Osaka, Japan. The efficiency of abiotic degradation of the PAEs with relatively short alkyl chain, butylbenzyl phthalate (BBP) and di-n-butyl phthalate (DBP) at neutral pH was significant less than that in the acidic or alkaline condition. Photolysis was considered to mainly contribute to total abiotic degradation at any pH. Neither hydrolysis nor photolysis of di-ethylhexyl phthalate (DEHP) proceeded significantly at any pH, especially hydrolysis at neutral pH was negligible. On the other hand, the degradation rate of di-isononyl phthalate (DINP) mainly catalyzed by photolysis was much higher compared with that of the other PAEs, and almost complete removal was observed during the experimental period at pH 5.0 and 9.0. As a whole, according to the half-life (t1/2) obtained in the experiments, the abiotic degradability of the PAEs was in the sequence, DINP (32-140 d) > DBP (50-360 d), BBP (58-480 d) > DEHP (390-1600 d) under sunlight irradiation (via photolysis plus hydrolysis). Although the abiotic degradation rate for BBP, DBP, and DEHP are much lower than their biodegradation rate reported, the photolysis rate for DINP is comparable to its biodegradation rate in the acidic or alkaline condition.

  1. Effect of season and sunlight on viral kinetics during hepatitis C virus therapy

    Science.gov (United States)

    Hernández-Alvarez, Noemi; Pascasio Acevedo, Juan Manuel; Quintero, Enrique; Fernández Vázquez, Inmaculada; García-Eliz, María; de la Revilla Negro, Juan; Crespo García, Javier; Hernández-Guerra, Manuel

    2017-01-01

    Background and aims Rapid viral response (RVR) during antiviral treatment for hepatitis C virus (HCV) predicts sustained viral response (SVR). Recently, vitamin D levels have been associated with SVR. As sunlight is the most important source of vitamin D and shows seasonal variation, we evaluated the effect of season on viral kinetics during peginterferon/ribavirin-based therapy for HCV. Methods Consecutive HCV patients treated with peginterferon/ribavirin and boceprevir/ telaprevir (June 2011–July 2014) were included. Patients were grouped according to season when therapy was initiated (Season A: May–October and Season B: November–April) depending on hours of daily sunlight. Multiple logistic regression analysis included factors known to influence SVR to treatment. The dependent variables were undetectable viral load (VL) or VL ≤15 UI/mL (VL ≤15) at weeks 4, 8 and 12, end of treatment and SVR. Results The study included 930 patients (66.8% men; median 54 years) treated with telaprevir (n=537) or boceprevir, without (n=481) or with lead-in therapy of peginterferon/ribavirin. Baseline characteristics of patients in Season A (45.3%, n=421) and Season B groups were similar. Overall, a higher rate of RVR (23.5% vs 16.1%, p=0.005) and VL ≤15 (51.0% vs 38.6%, p≤0.001) was observed in patients starting treatment during Season A versus Season B. By logistic regression analysis, initiating treatment in Season A proved to be an independent predictor of RVR and VL ≤15. Conclusions In our setting, seasonality affects viral kinetics in HCV genotype 1 patients treated with peginterferon/ribavirin-based therapy. Our findings support the hypothesis that vitamin D influences viral response to peginterferon/ribavirin-based therapy.

  2. Degradation of emerging contaminants from water under natural sunlight: The effect of season, pH, humic acids and nitrate and identification of photodegradation by-products.

    Science.gov (United States)

    Koumaki, Elena; Mamais, Daniel; Noutsopoulos, Constantinos; Nika, Maria-Christina; Bletsou, Anna A; Thomaidis, Nikolaos S; Eftaxias, Alexander; Stratogianni, Georgia

    2015-11-01

    Both photodegradation and hydrolysis of non-steroidal anti-inflammatory drugs (NSAIDs) and endocrine disrupting chemicals (EDCs) were investigated in order to evaluate their photochemical fate in aquatic environment and to assess the effect of season and specific characteristics of water (pH, humic acids and nitrate concentration) on the removal of target EDCs and NSAIDs through photodegradation. An additional objective was the identification of the photodegradation by-products of specific NSAIDs and their dependence on irradiation time. Selected compounds' transformation was investigated under natural sunlight radiation while control experiments were conducted in the dark. As expected, most of compounds' degradation rate decreased with decreasing light intensity between two different experimental periods. Most of the tested compounds exhibited different rates of degradation during direct and indirect photolysis. The degradation rate of the selected compounds increased in the presence of NO3(-) and the photodegradation rate was higher for some compounds in alkaline than in acidic solution. The effect of humic acids' presence in the water depends on the absorbance spectrum of the compound and the produced photosensitizers. More specifically, humic acids act as inner filter toward most of the selected NSAIDs and as photosensitizers toward most of the EDCs. The results of the irradiation experiments in the presence of both humic acids and NO3(-), indicate that the direct photolysis is much more efficient than indirect photochemical processes. Finally, several degradation by-products of ketoprofen and diclofenac were identified in the samples, exposed to sunlight. The dependence of these by-products on radiation time is also demonstrated. Copyright © 2015 Elsevier Ltd. All rights reserved.

  3. Photocatalytic degradation of phenol in natural seawater using visible light active carbon modified (CM)-n-TiO2 nanoparticles under UV light and natural sunlight illuminations.

    Science.gov (United States)

    Shaban, Yasser A; El Sayed, Mohamed A; El Maradny, Amr A; Al Farawati, Radwan Kh; Al Zobidi, Mousa I

    2013-04-01

    The photocatalytic degradation of phenol in seawater was investigated under UV and natural sunlight using visible light active carbon modified (CM)-n-TiO2 nanoparticles, synthesized via a sol-gel method. Carbon modification of n-TiO2 was performed using titanium butoxide, carbon-containing precursor, as a source of both carbon and titanium. For comparison, unmodified n-TiO2 was also synthesized by hydrolysis and oxidation of titanium trichloride in the absence of any carbon source. The presence of carbon in CM-n-TiO2 nanoparticles was confirmed by energy dispersive spectroscopy (EDS) analysis. Carbon modification was found to be responsible for lowering the bandgap energy from 3.14eV for n-TiO2 to 1.86eV for CM-n-TiO2 which in turn enhanced the photocatalytic activity of CM-n-TiO2 towards the degradation of phenol in seawater under illumination of UV light as well as natural sunlight. This enhanced photoresponse of CM-n-TiO2 is in agreement with the UV-Vis spectroscopic results that showed higher absorption of light in both UV and visible regions. The effects of catalyst dose, initial concentration of phenol, and pH were studied. The highest degradation rate was obtained at pH 3 and catalyst dose of 1.0gL(-1). The data photocatalytic degradation of phenol in seawater using CM-n-TiO2 were successfully fitted to Langmuir-Hinshelwood model, and can be described by pseudo-first order kinetics.

  4. Serum levels of vitamin D, sunlight exposure, and knee cartilage loss in older adults: the Tasmanian older adult cohort study.

    Science.gov (United States)

    Ding, Changhai; Cicuttini, Flavia; Parameswaran, Venkat; Burgess, John; Quinn, Steve; Jones, Graeme

    2009-05-01

    To determine the associations between serum levels of vitamin D, sunlight exposure, and knee cartilage loss cross-sectionally and longitudinally in older adults. A total of 880 randomly selected subjects (mean age 61 years [range 51-79 years], 50% women) were studied at baseline, and 353 of these subjects were studied 2.9 years later. Serum levels of 25-hydroxyvitamin D (25[OH]D) were assessed by radioimmunoassay, and sunlight exposure was assessed by questionnaire. T1-weighted fat-suppressed magnetic resonance imaging (MRI) of the right knee was performed to determine knee cartilage volume and defects. Knee radiographic osteoarthritis (OA) and knee pain were also assessed. The mean 25(OH)D serum level was 52.8 nmoles/liter at baseline (range 13-119 nmoles/liter). Winter sunlight exposure and serum 25(OH)D level were both positively associated with medial and lateral tibial cartilage volume, and a serum 25(OH)D levelSunlight exposure and serum 25(OH)D levels are both associated with decreased knee cartilage loss (assessed by radiograph or MRI). This is best observed using the whole range of 25(OH)D levels rather than predefined cut points and implies that achieving vitamin D sufficiency may prevent and/or retard cartilage loss in knee OA.

  5. No indications for an ultraviolet B radiation induced decline of immunological parameters after sunlight exposure among HIV infected homosexual men

    NARCIS (Netherlands)

    Maas J; Termorshuizen F; Geskus RB; Coutinho RA; Loveren H van; GG&GD Amsterdam; LPI

    2000-01-01

    Whether sunlight (especially ultraviolet B radiation: UVB) exposure is harmful to the cellular immunity of HIV infected individuals and whether it is associated with an accelerated progression toward AIDS is still under debate. Among HIV+ homosexual participants of the Amsterdam Cohort Study, the de

  6. Photodegradation of pharmaceuticals in the aquatic environment by sunlight and UV-A, -B and -C irradiation.

    Science.gov (United States)

    Kawabata, Kohei; Sugihara, Kazumi; Sanoh, Seigo; Kitamura, Shigeyuki; Ohta, Shigeru

    2013-01-01

    In order to investigate the effect of sunlight on the persistence and ecotoxicity of pharmaceuticals contaminating the aquatic environment, we exposed nine pharmaceuticals (acetaminophen (AA), amiodarone (AM), dapsone (DP), dexamethasone (DX), indomethacin (IM), naproxen (NP), phenytoin (PH), raloxifene (RL), and sulindac (SL)) in aqueous media to sunlight and to ultraviolet (UV) irradiation at 254, 302 or 365 nm (UV-C, UV-B or UV-A, respectively). Degradation of the pharmaceuticals was monitored by means of high-performance liquid chromatography (HPLC). Sunlight completely degraded AM, DP and DX within 6 hr, and partly degraded the other pharmaceuticals, except AA and PH, which were not degraded. Similar results were obtained with UV-B, while UV-A was less effective (both UV-A and -B are components of sunlight). All the pharmaceuticals were photodegraded by UV-C, which is used for sterilization in sewage treatment plants. Thus, the photodegradation rates of pharmaceuticals are dependent on both chemical structure and the wavelength of UV exposure. Toxicity assay using the luminescent bacteria test (ISO11348) indicated that UV irradiation reduced the toxicity of some pharmaceuticals to aquatic organisms by decreasing their amount (photodegradation) and increased the toxicity of others by generating toxic photoproduct(s). These results indicate the importance of investigating not only parent compounds, but also photoproducts in the risk assessment of pharmaceuticals in aquatic environments.

  7. Diffused sunlight driven highly synergistic pathway for complete mineralization of organic contaminants using reduced graphene oxide supported photocatalyst.

    Science.gov (United States)

    Babu, Sundaram Ganesh; Ramalingam Vinoth; Neppolian, Bernaurdshaw; Dionysiou, Dionysios D; Ashokkumar, Muthupandian

    2015-06-30

    Diffused sunlight is found to be an effective light source for the efficient degradation and mineralization of organic pollutant (methyl orange as a probe) by sono-photocatalytic degradation using reduced graphene oxide (rGO) supported CuO-TiO2 photocatalyst. The prepared catalysts are characterized by XRD, XPS, UV-vis DRS, PL, photoelectrochemical, SEM-EDS and TEM. A 10 fold synergy is achieved for the first time by combining sonochemical and photocatalytic degradation under diffused sunlight. rGO loading augments the activity of bare CuO-TiO2 more than two fold. The ability of rGO in storing, transferring, and shuttling electrons at the heterojunction between TiO2 and CuO facilitates the separation of photogenerated electron-hole pairs, as evidenced by the photoluminescence results. The complete mineralization of MO and the by-products within a short span of time is confirmed by TOC analysis. Further, hydroxyl radical mediated degradation under diffused sunlight is confirmed by LC-MS. This system shows similar activity for the degradation of methylene blue and 4-chlorophenol indicating the versatility of the catalyst for the degradation of various pollutants. This investigation is likely to open new possibilities for the development of highly efficient diffused sunlight driven TiO2 based photocatalysts for the complete mineralization of organic contaminants.

  8. No indications for an ultraviolet B radiation induced decline of immunological parameters after sunlight exposure among HIV infected homosexual men

    NARCIS (Netherlands)

    Maas J; Termorshuizen F; Geskus RB; Coutinho RA; Loveren H van; GG&GD Amsterdam; LPI

    2000-01-01

    Whether sunlight (especially ultraviolet B radiation: UVB) exposure is harmful to the cellular immunity of HIV infected individuals and whether it is associated with an accelerated progression toward AIDS is still under debate. Among HIV+ homosexual participants of the Amsterdam Cohort Study, the de

  9. Effect of Natural Sunlight on Bacterial Activity and Differential Sensitivity of Natural Bacterioplankton Groups in Northwestern Mediterranean Coastal Waters

    Science.gov (United States)

    Alonso-Sáez, Laura; Gasol, Josep M.; Lefort, Thomas; Hofer, Julia; Sommaruga, Ruben

    2006-01-01

    We studied the effects of natural sunlight on heterotrophic marine bacterioplankton in short-term experiments. We used a single-cell level approach involving flow cytometry combined with physiological probes and microautoradiography to determine sunlight effects on the activity and integrity of the cells. After 4 h of sunlight exposure, most bacterial cells maintained membrane integrity and viability as assessed by the simultaneous staining with propidium iodide and SYBR green I. In contrast, a significant inhibition of heterotrophic bacterial activity was detected, measured by 5-cyano-2,3 ditolyl tetrazolium chloride reduction and leucine incorporation. We applied microautoradiography combined with catalyzed reporter deposition-fluorescence in situ hybridization to test the sensitivity of the different bacterial groups naturally occurring in the Northwestern Mediterranean to sunlight. Members of the Gammaproteobacteria and Bacteroidetes groups appeared to be highly resistant to solar radiation, with small changes in activity after exposure. On the contrary, Alphaproteobacteria bacteria were more sensitive to radiation as measured by the cell-specific incorporation of labeled amino acids, leucine, and ATP. Within Alphaproteobacteria, bacteria belonging to the Roseobacter group showed higher resistance than members of the SAR11 cluster. The activity of Roseobacter was stimulated by exposure to photosynthetic available radiation compared to the dark treatment. Our results suggest that UV radiation can significantly affect the in situ single-cell activity of bacterioplankton and that naturally dominating phylogenetic bacterial groups have different sensitivity to natural levels of incident solar radiation. PMID:16957198

  10. Heterotrophic bacterium Pseudomonas saponiphila and sunlight as impact factors on organo-mineral colloids transformations in boreal humic waters

    Science.gov (United States)

    Oleinikova, Olga; Drozdova, Olga; Shirokova, Liudmila; Lapitskiy, Sergey; Bychkov, Andrew; Pokrovsky, Oleg

    2017-04-01

    Two of the main factors of carbon balance in high latitudes, known to govern the CO2 flux from the lakes and rivers to the atmosphere, are bacterial mineralization (respiration) of allochthonous dissolved organic matter (DOM) and photochemical degradation of DOM. Yet, in contrast to large numbers of experimental and field studies on these factors impact on the utilization of DOM of different origin, the fate of metals bound to colloids during bacterial processing of DOM and behavior of trace element (TE) during photodegradation of DOM remains poorly constrained. This is especially important in view of essentially organic and organo-mineral colloidal status of TE in most boreal waters. To answer this questions, a monoculture of Pseudomonas saponiphila from a boreal creek in NW Karelia (Russia) was separated and allowed to interact with boreal peat leachate in nutrient-free media. We quantified colloidal transformation of the peat leachate during 5-days activity of live bacteria using 3 kDa, 50 kDa Amicon® centrifugal filtration and 0.45 µm syringe filtration. The total net decrease of the concentration of Dissolved Organic Carbon (DOC) over 93 h of exposure was within 5% of the initial value for all fractions except low molecular weight one (exposure, the DOM in stream photodegraded in a much smaller degree than that in the bog water with 25 and 60% removal of initial DOC, respectively. Specific UV absorption (SUVA254) decreased by a factor of 1.75 and 5 over 200 h of exposure in stream and bog water, respectively. The removal of Fe and Al occurred only in the bog water (90 % and 50% respectively, over 5 days of reaction), whereas no detectable decrease of Al and Fe concentration (sunlight exposure. We acknowledge support from a RFBR research projects №№ 16-55-150002 HЦHИ_a, 15-05-05000_a, 14-05-00430_a, 16-05-00542_a. Experimental study was supported by RSF № 14-50-00029.

  11. Photocatalytic hydrogen generation of Pt-Sr(Zr1-xYx)03-δ-Ti02 heterojunction under the irradiation of simulated sunlight

    Institute of Scientific and Technical Information of China (English)

    Jianhui YAN; Qiang LIU; Luxiong GUAN; Feng LIANG; Haojie GU

    2009-01-01

    The Pt-Sr(Zr1-xYx)O3-δ-Ti02 (Pt-SZYT) heterojunction photocatalysts were prepared by a photodepo-sition method. The composite particles were characterized by XRD, SEM, UV-Vis DRS, and PL techniques. Photocatalytic hydrogen generation in H2C2O4 aqueous solution under the irradiation of simulated sunlight was used as a probe reaction to evaluate the photocatalytic activity of the photocatalysts. The effects of the content of Pt loading and the concentration of oxalic acid on the photocatalytic activity of the catalyst were discussed. The continuous photocatalytic activity of the Pt-SZYT and the relationship between PL intensity and hydrogen generation were also discussed. The results show that Pt-SZYT catalysts had high photocatalytic activity of hydrogen generation. The content of Pt loading and the concentration of oxalic acid have important influence on the photocatalytic hydrogen generation. The optimal loading content of platinum was 0.90 mass%. Under this condition, the average rate of photocatalytic hydrogen generation was 1.68mmol-h ' when the concentration of oxalic acid was 50mmol-L"'. The higher the photocatalytic activity, the weaker the PL intensity, which was demonstrated by the analysis of PL spectra.

  12. Simulated-sunlight-activated photocatalysis of Methylene Blue using cerium-doped SiO2/TiO2 nanostructured fibers

    Institute of Scientific and Technical Information of China (English)

    Yu Liu; Hongbing Yu; Zhenning Lv; Sihui Zhan; Jiangyao Yang; Xinhong Peng; Yixuan Ren; Xiaoyan Wu

    2012-01-01

    Cerium-doped SiO2/TiO2 nanostructured fibers were fabricated by electrospinning technology.The prepared fibers were characterized by thermogravimetric analysis (TGA),scanning electron microscopy (SEM),X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FT-IR).Using the fibers as catalysts,photocatalytic degradation of Methylene Blue (MB) aqueous solution was carried out under simulated sunlight.The 0.2% Ce doping proved to be the optimal concentration for the doping of TiO2/SiO2,compared to other Ce-doped molar concentrations.The 0.2% Ce-doped SiO2/TiO2 fibers exhibited higher photocatalytic activity than industrial Degussa P25 and the samples doped with only Ce or SiO2.The reasons for improving the photocatalytic activity were also discussed.Several operational parameters were studied,which showed that the photocatalytic efficiency of MB was influenced by parameters such as the initial dye concentration,the initial pH,inorganic anions,and so on.In addition,the influences of an electron acceptor and a radical scavenger suggested that OH was the dominant photooxidant during the photocatalytic process.The reuse evaluation of the fibers indicated that their photocatalytic activity had good stability.

  13. Weathering patterns of polycyclic aromatic hydrocarbons contained in submerged Deepwater Horizon oil spill residues when re-exposed to sunlight.

    Science.gov (United States)

    John, Gerald F; Han, Yuling; Clement, T Prabhakar

    2016-12-15

    The Deepwater Horizon (DWH) oil spill event released a large amount of sweet crude oil into the Gulf of Mexico (GOM). An unknown portion of this oil that arrived along the Alabama shoreline interacted with nearshore sediments and sank forming submerged oil mats (SOMs). A considerable amount of hydrocarbons, including polycyclic aromatic hydrocarbons (PAHs), were trapped within these buried SOMs. Recent studies completed using the oil spill residues collected along the Alabama shoreline have shown that several PAHs, especially higher molecular weight PAHs (four or more aromatic rings), are slowly weathering compared to the weathering levels experienced by the oil when it was floating over the GOM. In this study we have hypothesized that the weathering rates of PAHs in SOMs have slowed down because the buried oil was isolated from direct exposure to sunlight, thus hindering the photodegradation pathway. We further hypothesized that re-exposing SOMs to sunlight can reactivate various weathering reactions. Also, SOMs contain 75-95% sand (by weight) and the entrapped sand could either block direct sunlight or form large oil agglomerates with very little exposed surface area; these processes could possibly interfere with weathering reactions. To test these hypotheses, we completed controlled experiments to study the weathering patterns of PAHs in a field recovered SOM sample after re-exposing it to sunlight. Our experimental results show that the weathering levels of several higher molecular weight PAHs have slowed down primarily due to the absence of sunlight-induced photodegradation reactions. The data also show that sand particles in SOM material could potentially interfere with photodegradation reactions.

  14. Sunlight exposure and cardiovascular risk factors in the REGARDS study: a cross-sectional split-sample analysis.

    Science.gov (United States)

    Kent, Shia T; Cushman, Mary; Howard, George; Judd, Suzanne E; Crosson, William L; Al-Hamdan, Mohammad Z; McClure, Leslie A

    2014-06-19

    Previous research has suggested that vitamin D and sunlight are related to cardiovascular outcomes, but associations between sunlight and risk factors have not been investigated. We examined whether increased sunlight exposure was related to improved cardiovascular risk factor status. Residential histories merged with satellite, ground monitor, and model reanalysis data were used to determine previous-year sunlight radiation exposure for 17,773 black and white participants aged 45+ from the US. Exploratory and confirmatory analyses were performed by randomly dividing the sample into halves. Logistic regression models were used to examine relationships with cardiovascular risk factors. The lowest, compared to the highest quartile of insolation exposure was associated with lower high-density lipoprotein levels in adjusted exploratory (-2.7 mg/dL [95% confidence interval: -4.2, -1.2]) and confirmatory (-1.5 mg/dL [95% confidence interval: -3.0, -0.1]) models. The lowest, compared to the highest quartile of insolation exposure was associated with higher systolic blood pressure levels in unadjusted exploratory and confirmatory, as well as the adjusted exploratory model (2.3 mmHg [95% confidence interval: 0.8, 3.8]), but not the adjusted confirmatory model (1.6 mg/dL [95% confidence interval: -0.5, 3.7]). The results of this study suggest that lower long-term sunlight exposure has an association with lower high-density lipoprotein levels. However, all associations were weak, thus it is not known if insolation may affect cardiovascular outcomes through these risk factors.

  15. Sunlight exposure is important for preventing hip fractures in patients with Alzheimer's disease, Parkinson's disease, or stroke.

    Science.gov (United States)

    Iwamoto, J; Takeda, T; Matsumoto, H

    2012-04-01

    Hypovitaminosis D as a result of malnutrition or sunlight deprivation, increased bone resorption, low bone mineral density (BMD), or an increased risk of falls may contribute to an increased risk of hip fractures in patients with neurological diseases, including Alzheimer's disease, Parkinson's disease, and stroke. The purpose of this study was to clarify the efficacy of sunlight exposure for reducing the risk of hip fractures in patients with such neurological diseases. The English literature was searched using PubMed, and randomized controlled trials evaluating the efficacy of sunlight exposure for reducing the risk of hip fractures in patients with Alzheimer's disease, Parkinson's disease, and stroke were identified. The relative risk and the 95% confidence interval were calculated for individual randomized controlled trials, and a pooled data analysis (meta-analysis) was performed. Three randomized controlled trials were identified. Sunlight exposure improved hypovitaminosis D and increased the BMD. The relative risk (95% confidence interval) of hip fractures was 0.22 (0.05, 1.01) for Alzheimer's disease, 0.27 (0.08, 0.96) for Parkinson's disease, and 0.17 (0.02, 1.36) for stroke. The relative risk (95% confidence interval) calculated for the pooled data analysis was 0.23 (0.10, 0.56) (P = 0.0012), suggesting a significant risk reduction rate of 77%. The present meta-analysis added additional evidence indicating the efficacy of sunlight exposure for reducing the risk of hip fractures in patients with Alzheimer's disease, Parkinson's disease, and stroke. © 2011 John Wiley & Sons A/S.

  16. Is sunlight exposure a risk factor for age-related macular degeneration? A systematic review and meta-analysis.

    Science.gov (United States)

    Sui, Guo-Yuan; Liu, Guang-Cong; Liu, Guang-Ying; Gao, Yan-Yan; Deng, Yan; Wang, Wen-Ying; Tong, Shu-Hui; Wang, Lie

    2013-04-01

    Epidemiologists have recently investigated sunlight exposure as a risk factor for age-related macular degeneration (AMD), but there remains an ongoing dispute over this association due to insufficient evidence and unreliable data. To analyse comprehensively the epidemiological literature concerning the association between AMD and sunlight exposure. We systematically reviewed the epidemiological literature concerning the association between AMD and sunlight exposure. An electronic search was performed of PubMed, Web of Science and CNKI, which was supplemented by hand searching. The selection of studies, data abstraction and quality assessment were performed independently by three reviewers. After these steps, we performed a random-effects meta-analysis, followed by subgroup analysis and sensitivity analysis, including a random-effects meta-regression for study-specific covariates. Fourteen studies were identified. Twelve studies identified an increasing risk of AMD with greater sunlight exposure, six of which reported significant risks. The pooled OR was 1.379 (95% CI 1.091 to 1.745). The subgroup of non-population-based studies revealed a significant risk (OR 2.018, 1.248 to 3.265, p=0.004). We identified the gross domestic product (GDP) per capita (p=0.048), but not the latitude (p=0.21), as a factor that led to heterogeneity according to the meta-regression. The epidemiological literature published to date indicates that individuals with more sunlight exposure are at a significantly increased risk of AMD. The OR significantly decreased with increasing GDP per capita.

  17. Mitochondrial tolerance to single and repeat exposure to simulated sunlight in human epidermal and dermal skin cells.

    Science.gov (United States)

    Kelly, J; Murphy, J E J

    2016-12-01

    Sunlight represents the primary threat to mitochondrial integrity in skin given the unique nature of the mitochondrial genome and its proximity to the electron transport chain. The accumulation of mitochondrial DNA (mtDNA) mutations is a key factor in many human pathologies and this is linked to key roles of mitochondrial function in terms of energy production and cell regulation. The main objective of this study was to evaluate solar radiation induced changes in mitochondrial integrity, function and dynamics in human skin cells using a Q-Sun solar simulator to deliver a close match to the intensity of summer sunlight. Spontaneously immortalised human skin epidermal keratinocytes (HaCaT) and Human Dermal Fibroblasts (HDFn) were divided into two groups. Group A were irradiated once and Group B twice 7days apart and evaluated using cell survival, viability and mitochondrial membrane potential (MMP) and mass at 1, 4 and 7days post one exposure for Group A and 1, 4, 7 and 14days post second exposure for Group B. Viability and survival of HaCaT and HDFn cells decreased after repeat exposure to Simulated Sunlight Irradiation (SSI) with no recovery. HDFn cells showed no loss in MMP after one or two exposures to SSI compared to HaCaT cells which showed a periodic loss of MMP after one exposure with a repeat exposure causing a dramatic decrease from which cells did not recover. Mitochondrial Mass in exposed HDFn cells was consistent with control after one or two exposures to SSI; however mitochondrial mass was significantly decreased in HaCaT cells. Data presented here suggests that mitochondria in epidermal cells are more sensitive to sunlight damage compared to mitochondria in dermal cells, despite their origin, confirming a skin layer specific sensitivity to sunlight, but not as expected. Copyright © 2016 Elsevier B.V. All rights reserved.

  18. Diffused sunlight driven highly synergistic pathway for complete mineralization of organic contaminants using reduced graphene oxide supported photocatalyst

    Energy Technology Data Exchange (ETDEWEB)

    Babu, Sundaram Ganesh; Ramalingam Vinoth [SRM Research Institute, SRM University, Kattankulathur 603203, Chennai, Tamilnadu (India); Neppolian, Bernaurdshaw, E-mail: neppolian.b@res.srmuniv.ac.in [SRM Research Institute, SRM University, Kattankulathur 603203, Chennai, Tamilnadu (India); Dionysiou, Dionysios D. [Environmental Engineering and Science Program, Department of Biomedical, Chemical and Environmental Engineering, University of Cincinnati, Cincinnati, OH 45221-0012 (United States); Ashokkumar, Muthupandian [The School of Chemistry, University of Melbourne, Parkville, Melbourne, Victoria 3010 (Australia)

    2015-06-30

    Highlights: • Diffused sunlight is firstly used as an effective source for the degradation of organics. • More than 10 fold synergistic effect is achieved by sono-photocatalysis. • rGO enhances the degradation efficiency up to 54% as compared with CuO–TiO{sub 2} alone. • Plausible mechanism and intermediates formed are supported with experimental studies. - Abstract: Diffused sunlight is found to be an effective light source for the efficient degradation and mineralization of organic pollutant (methyl orange as a probe) by sono-photocatalytic degradation using reduced graphene oxide (rGO) supported CuO–TiO{sub 2} photocatalyst. The prepared catalysts are characterized by XRD, XPS, UV–vis DRS, PL, photoelectrochemical, SEM-EDS and TEM. A 10 fold synergy is achieved for the first time by combining sonochemical and photocatalytic degradation under diffused sunlight. rGO loading augments the activity of bare CuO–TiO{sub 2} more than two fold. The ability of rGO in storing, transferring, and shuttling electrons at the heterojunction between TiO{sub 2} and CuO facilitates the separation of photogenerated electron–hole pairs, as evidenced by the photoluminescence results. The complete mineralization of MO and the by-products within a short span of time is confirmed by TOC analysis. Further, hydroxyl radical mediated degradation under diffused sunlight is confirmed by LC–MS. This system shows similar activity for the degradation of methylene blue and 4-chlorophenol indicating the versatility of the catalyst for the degradation of various pollutants. This investigation is likely to open new possibilities for the development of highly efficient diffused sunlight driven TiO{sub 2} based photocatalysts for the complete mineralization of organic contaminants.

  19. Annual Statistical Supplement, 2008

    Data.gov (United States)

    Social Security Administration — The Annual Statistical Supplement, 2008 includes the most comprehensive data available on the Social Security and Supplemental Security Income programs. More than...

  20. Annual Statistical Supplement, 2004

    Data.gov (United States)

    Social Security Administration — The Annual Statistical Supplement, 2004 includes the most comprehensive data available on the Social Security and Supplemental Security Income programs. More than...

  1. Annual Statistical Supplement, 2006

    Data.gov (United States)

    Social Security Administration — The Annual Statistical Supplement, 2006 includes the most comprehensive data available on the Social Security and Supplemental Security Income programs. More than...

  2. Annual Statistical Supplement, 2016

    Data.gov (United States)

    Social Security Administration — The Annual Statistical Supplement, 2016 includes the most comprehensive data available on the Social Security and Supplemental Security Income programs. More than...

  3. Annual Statistical Supplement, 2010

    Data.gov (United States)

    Social Security Administration — The Annual Statistical Supplement, 2010 includes the most comprehensive data available on the Social Security and Supplemental Security Income programs. More than...

  4. Annual Statistical Supplement, 2002

    Data.gov (United States)

    Social Security Administration — The Annual Statistical Supplement, 2002 includes the most comprehensive data available on the Social Security and Supplemental Security Income programs. More than...

  5. Annual Statistical Supplement, 2003

    Data.gov (United States)

    Social Security Administration — The Annual Statistical Supplement, 2003 includes the most comprehensive data available on the Social Security and Supplemental Security Income programs. More than...

  6. Annual Statistical Supplement, 2011

    Data.gov (United States)

    Social Security Administration — The Annual Statistical Supplement, 2011 includes the most comprehensive data available on the Social Security and Supplemental Security Income programs. More than...

  7. Annual Statistical Supplement, 2000

    Data.gov (United States)

    Social Security Administration — The Annual Statistical Supplement, 2000 includes the most comprehensive data available on the Social Security and Supplemental Security Income programs. More than...

  8. Annual Statistical Supplement, 2015

    Data.gov (United States)

    Social Security Administration — The Annual Statistical Supplement, 2015 includes the most comprehensive data available on the Social Security and Supplemental Security Income programs. More than...

  9. Annual Statistical Supplement, 2009

    Data.gov (United States)

    Social Security Administration — The Annual Statistical Supplement, 2009 includes the most comprehensive data available on the Social Security and Supplemental Security Income programs. More than...

  10. Annual Statistical Supplement, 2014

    Data.gov (United States)

    Social Security Administration — The Annual Statistical Supplement, 2014 includes the most comprehensive data available on the Social Security and Supplemental Security Income programs. More than...

  11. Annual Statistical Supplement, 2007

    Data.gov (United States)

    Social Security Administration — The Annual Statistical Supplement, 2007 includes the most comprehensive data available on the Social Security and Supplemental Security Income programs. More than...

  12. Annual Statistical Supplement, 2005

    Data.gov (United States)

    Social Security Administration — The Annual Statistical Supplement, 2005 includes the most comprehensive data available on the Social Security and Supplemental Security Income programs. More than...

  13. Annual Statistical Supplement, 2001

    Data.gov (United States)

    Social Security Administration — The Annual Statistical Supplement, 2001 includes the most comprehensive data available on the Social Security and Supplemental Security Income programs. More than...

  14. Concentrating Solar Power: Best Practices Handbook for the Collection and Use of Solar Resource Data (CSP)

    Energy Technology Data Exchange (ETDEWEB)

    Stoffel, T.; Renne, D.; Myers, D.; Wilcox, S.; Sengupta, M.; George, R.; Turchi, C.

    2010-09-01

    As the world looks for low-carbon sources of energy, solar power stands out as the most abundant energy resource. Harnessing this energy is the challenge for this century. Photovoltaics and concentrating solar power (CSP) are two primary forms of electricity generation using sunlight. These use different technologies, collect different fractions of the solar resource, and have different siting and production capabilities. Although PV systems are most often deployed as distributed generation sources, CSP systems favor large, centrally located systems. Accordingly, large CSP systems require a substantial investment, sometimes exceeding $1 billion in construction costs. Before such a project is undertaken, the best possible information about the quality and reliability of the fuel source must be made available. That is, project developers need to have reliable data about the solar resource available at specific locations to predict the daily and annual performance of a proposed CSP plant. Without these data, no financial analysis is possible. This handbook presents detailed information about solar resource data and the resulting data products needed for each stage of the project.

  15. Exposure to sunlight reduces the risk of myopia in rhesus monkeys.

    Science.gov (United States)

    Wang, Yong; Ding, Hui; Stell, William K; Liu, Liangping; Li, Saiqun; Liu, Hongshan; Zhong, Xingwu

    2015-01-01

    Exposure to sunlight has recently been postulated as responsible for the effect that more time spent outdoors protects children from myopia, while early life exposure to natural light was reported to be possibly related to onset of myopia during childhood. In this study, we had two aims: to determine whether increasing natural light exposure has a protective effect on hyperopic defocus-induced myopia, and to observe whether early postnatal exposure to natural light causes increased risk of refractive error in adolescence. Eight rhesus monkeys (aged 20-30 days) were treated monocularly with hyperopic-defocus (-3.0D lens) and divided randomly into two groups: AL group (n=4), reared under Artificial (indoor) Lighting (08:00-20:00); and NL group (n=4), exposed to Natural (outdoor) Light for 3 hours per day (11:00-14:00), and to indoor lighting for the rest of the light phase. After being reared with lenses for ca. 190 days, all monkeys were returned to unrestricted vision until the age of 3 years. Another eight age-matched monkeys, reared with unrestricted vision under artificial lighting since birth, were employed as controls. The ocular refraction, corneal curvature and axial dimensions were measured before lens-wearing (at 23±3 days of age), monthly during the light phase, and at the age of puberty (at 1185+3 days of age). During the lens-wearing treatment, infant monkeys in the NL group were more hyperopic than those in the AL group (F=5.726, P=0.032). Furthermore, the two eyes of most NL monkeys remained isometropic, whereas 3 of 4 AL monkeys developed myopic anisometropia more than -2.0D. At adolescence, eyes of AL monkeys showed significant myopic anisometropia compared with eyes of NL monkeys (AL vs NL: -1.66±0.87D vs -0.22±0.44D; P=0.002) and controls (AL vs Control: -1.66±0.87D vs -0.05±0.85D; Pexposure to natural outdoor light might have an effect to reduced hyperopic defocus-induced myopia. Also, the data imply that early life exposure to sunlight may

  16. Sunlight-Exposed Biofilm Microbial Communities Are Naturally Resistant to Chernobyl Ionizing-Radiation Levels

    Science.gov (United States)

    Ragon, Marie; Restoux, Gwendal; Moreira, David; Møller, Anders Pape; López-García, Purificación

    2011-01-01

    Background The Chernobyl accident represents a long-term experiment on the effects of exposure to ionizing radiation at the ecosystem level. Though studies of these effects on plants and animals are abundant, the study of how Chernobyl radiation levels affect prokaryotic and eukaryotic microbial communities is practically non-existent, except for a few reports on human pathogens or soil microorganisms. Environments enduring extreme desiccation and UV radiation, such as sunlight exposed biofilms could in principle select for organisms highly resistant to ionizing radiation as well. Methodology/Principal Findings To test this hypothesis, we explored the diversity of microorganisms belonging to the three domains of life by cultivation-independent approaches in biofilms developing on concrete walls or pillars in the Chernobyl area exposed to different levels of radiation, and we compared them with a similar biofilm from a non-irradiated site in Northern Ireland. Actinobacteria, Alphaproteobacteria, Bacteroidetes, Acidobacteria and Deinococcales were the most consistently detected bacterial groups, whereas green algae (Chlorophyta) and ascomycete fungi (Ascomycota) dominated within the eukaryotes. Close relatives to the most radio-resistant organisms known, including Rubrobacter species, Deinococcales and melanized ascomycete fungi were always detected. The diversity of bacteria and eukaryotes found in the most highly irradiated samples was comparable to that of less irradiated Chernobyl sites and Northern Ireland. However, the study of mutation frequencies in non-coding ITS regions versus SSU rRNA genes in members of a same actinobacterial operational taxonomic unit (OTU) present in Chernobyl samples and Northern Ireland showed a positive correlation between increased radiation and mutation rates. Conclusions/Significance Our results show that biofilm microbial communities in the most irradiated samples are comparable to non-irradiated samples in terms of general

  17. Sunlight-exposed biofilm microbial communities are naturally resistant to chernobyl ionizing-radiation levels.

    Directory of Open Access Journals (Sweden)

    Marie Ragon

    Full Text Available BACKGROUND: The Chernobyl accident represents a long-term experiment on the effects of exposure to ionizing radiation at the ecosystem level. Though studies of these effects on plants and animals are abundant, the study of how Chernobyl radiation levels affect prokaryotic and eukaryotic microbial communities is practically non-existent, except for a few reports on human pathogens or soil microorganisms. Environments enduring extreme desiccation and UV radiation, such as sunlight exposed biofilms could in principle select for organisms highly resistant to ionizing radiation as well. METHODOLOGY/PRINCIPAL FINDINGS: To test this hypothesis, we explored the diversity of microorganisms belonging to the three domains of life by cultivation-independent approaches in biofilms developing on concrete walls or pillars in the Chernobyl area exposed to different levels of radiation, and we compared them with a similar biofilm from a non-irradiated site in Northern Ireland. Actinobacteria, Alphaproteobacteria, Bacteroidetes, Acidobacteria and Deinococcales were the most consistently detected bacterial groups, whereas green algae (Chlorophyta and ascomycete fungi (Ascomycota dominated within the eukaryotes. Close relatives to the most radio-resistant organisms known, including Rubrobacter species, Deinococcales and melanized ascomycete fungi were always detected. The diversity of bacteria and eukaryotes found in the most highly irradiated samples was comparable to that of less irradiated Chernobyl sites and Northern Ireland. However, the study of mutation frequencies in non-coding ITS regions versus SSU rRNA genes in members of a same actinobacterial operational taxonomic unit (OTU present in Chernobyl samples and Northern Ireland showed a positive correlation between increased radiation and mutation rates. CONCLUSIONS/SIGNIFICANCE: Our results show that biofilm microbial communities in the most irradiated samples are comparable to non-irradiated samples in

  18. Trans-Pecos Photovoltaic Concentration Experiment. Final report for Phase-I system design, 6 June 1978-28 February 1979

    Energy Technology Data Exchange (ETDEWEB)

    Marcy, W.M.; Dudek, R.A.

    1979-03-30

    The Trans-Pecos Photovoltaic Concentrating Experiment is the design of a 200 kWe peak photovoltaic concentrating system applied to deep well irrigation in the Trans-Pecos region of Texas. The site selected is typical of deep well irrigation in arid regions of Texas, New Mexico, and Arizona. The existing well utilizes a 200 horse power, three phase, 480 volt induction motor to lift water 540 feet to irrigate 380 acres. The Trans-Pecos Photovoltaic Concentration (PVC) system employs a two axis (azimuth-elevation) tracking parabolic concentrator module that focuses sunlight at 38X concentration on two strings of actively cooled silicon solar cells. The direct current from a field of 102 collector modules is converted by a maximum power point electric power conditioning system to three phase alternating current. The power from the power conditioning system is connected through appropriate switchgear in parallel with the utility grid to the well's induction motor. The operational philosophy of the experiment is to displace daytime utility power with solar generated electric power. The solar system is sized to provide approximately 50 percent of the 24 hour energy demand of the motor. This requires an energy exchange with the utility since peak solar power (200 kWe) generated exceeds the peak motor demand (149.2 kWe). The annual energy production is projected to be 511 Mwh using El Paso, Texas solar TMY data. System electrical power production efficiency is projected to be 7.4 percent at the design point, and 7.0 percent on an annual electrical energy production basis. The system is projected to provide 37.8 percent of the 24 hour energy demand of the motor at the design point of March 10, excluding energy delivered to the grid in excess of motor demand. The total energy produced is projected to be 39.0 percent of the 24 hour energy demand of the motor at the design point of March 10.

  19. Annual Energy Review, 2008

    Energy Technology Data Exchange (ETDEWEB)

    None

    2009-06-01

    The Annual Energy Review (AER) is the Energy Information Administration's (EIA) primary report of annual historical energy statistics. For many series, data begin with the year 1949. Included are statistics on total energy production, consumption, trade, and energy prices; overviews of petroleum, natural gas, coal, electricity, nuclear energy, renewable energy, and international energy; financial and environment indicators; and data unit conversions.

  20. CSIR Annual report 1993

    CSIR Research Space (South Africa)

    CSIR

    1993-01-01

    Full Text Available stream_source_info Annual Report_ 1993.pdf.txt stream_content_type text/plain stream_size 45 Content-Encoding ISO-8859-1 stream_name Annual Report_ 1993.pdf.txt Content-Type text/plain; charset=ISO-8859-1 ...

  1. CSIR Annual report 1974

    CSIR Research Space (South Africa)

    CSIR

    1974-01-01

    Full Text Available stream_source_info Annual Report_1974.pdf.txt stream_content_type text/plain stream_size 89 Content-Encoding ISO-8859-1 stream_name Annual Report_1974.pdf.txt Content-Type text/plain; charset=ISO-8859-1 ...

  2. CSIR Annual report 1972

    CSIR Research Space (South Africa)

    CSIR

    1972-01-01

    Full Text Available stream_source_info Annual Report_ 1972.pdf.txt stream_content_type text/plain stream_size 95 Content-Encoding ISO-8859-1 stream_name Annual Report_ 1972.pdf.txt Content-Type text/plain; charset=ISO-8859-1 ...

  3. CSIR Annual report 1975

    CSIR Research Space (South Africa)

    CSIR

    1975-01-01

    Full Text Available stream_source_info Annual Report_1975.pdf.txt stream_content_type text/plain stream_size 101 Content-Encoding ISO-8859-1 stream_name Annual Report_1975.pdf.txt Content-Type text/plain; charset=ISO-8859-1 ...

  4. CSIR Annual report 1979

    CSIR Research Space (South Africa)

    CSIR

    1979-01-01

    Full Text Available stream_source_info CSIR Annual report_1979.pdf.txt stream_content_type text/plain stream_size 86 Content-Encoding ISO-8859-1 stream_name CSIR Annual report_1979.pdf.txt Content-Type text/plain; charset=ISO-8859-1 ...

  5. CSIR Annual report 1978

    CSIR Research Space (South Africa)

    CSIR

    1978-01-01

    Full Text Available stream_source_info Annual Report_1978.pdf.txt stream_content_type text/plain stream_size 78 Content-Encoding ISO-8859-1 stream_name Annual Report_1978.pdf.txt Content-Type text/plain; charset=ISO-8859-1 ...

  6. Annual Review of Biophysics.

    Science.gov (United States)

    Hatzis, Christos

    2013-07-01

    Annual Review of Biophysics Rees D. Dill K., Williamson J., Annual Reviews Palo Alto, CA, 2010. 581 pp. (hardcover), ISBN: 978-0-8243-1839-0, © 2013 Doody's Review Service. Doody's Review Service. © 2013 American Association of Physicists in Medicine.

  7. Annual Report 1997

    Energy Technology Data Exchange (ETDEWEB)

    Golnik, N.; Mika, J.R.; Wieteska, K. [eds.

    1998-12-31

    This Annual Report of the Institute of Atomic Energy describes the results of the research works carried out at the Institute at 1997. As in the preceding years the authors of the individual scientific reports published in this Annual Report are fully responsible for their content and layout. The Report contains the information on other activities of the Institute as well. (author)

  8. Reusable sunlight activated photocatalyst Ag{sub 3}PO{sub 4} and its significant antibacterial activity

    Energy Technology Data Exchange (ETDEWEB)

    Thiyagarajan, Shankar; Singh, Sarika; Bahadur, D., E-mail: dhirenb@iitb.ac.in

    2016-04-15

    A simple and surfactant free soft chemical approach is adopted for the successful synthesis of Ag{sub 3}PO{sub 4} nanoparticles (NPs) at room temperature. The obtained Ag{sub 3}PO{sub 4} NPs are nearly spherical in shape with a size of 250 ± 50 nm. These NPs are highly efficient for the degradation of three organic dyes (methylene blue, rhodamine B and methyl orange) under four different types of light sources. In this case, the superior photocatalytic activity is mainly driven by singlet oxygen radicals and it is confirmed through the electron spin resonance (ESR) spin trapping technique, using several quenchers/sources. Notably, these NPs have the ability to absorb large portion of solar spectrum and therefore it displays higher efficiency under sunlight as compared to UV-C light and a 60 W household compact fluorescence lamp (CFL). Furthermore, these NPs exhibit excellent colloidal stability and recycling capability for the degradation of dyes. In addition, it possesses significant antibacterial activity with complete inhibition of bacterial pathogen, Escherichia coli at a very low concentration (0.01 mg/mL) after a mere 15 min of incubation time. The inhibition of bacterial growth is also suggested from the generation of intracellular reactive oxygen species (ROS) in E. coli by fluorescence microscopy. Thus, these NPs may provide a potential outcome for the environmental remediation. - Graphical abstract: Schematic representation of the mechanism involved in photodegradation of organic dyes and inhibition of bacterial growth using Ag{sub 3}PO{sub 4} nanoparticles. - Highlights: • Excellent catalytic activity for dyes degradation under different light sources. • Mechanism involving catalyst mediated ROS generation in photocatalysis suggested. • Good recycling capability of Ag{sub 3}PO{sub 4} even after the fifth cycles. • Extraordinary antibacterial activity of Ag{sub 3}PO{sub 4} after a very short incubation time. • Detection of intracellular

  9. New photocatalyst based on graphene oxide/chitin for degradation of dyes under sunlight.

    Science.gov (United States)

    Wang, Yuntao; Pei, Yaqiong; Xiong, Wenfei; Liu, Tingguo; Li, Jing; Liu, Shilin; Li, Bin

    2015-11-01

    Sunlight photocatalyst was fabricated by in situ synthesis of Cu2O in the regenerated chitin (RC)/graphene oxide (GO) composite film, where the porous chitin film was used as the microreactor for the formation of nano Cu2O. Nano Cu2O was immobilized and evenly distributed in the matrix and Cu2O tended to grow on the GO sheets. Cu2O inside the matrix excite and generate free photoelectrons and electron holes, which was responsible for the degradation of dyes, while GO transferred the yielded photoelectrons to prevent the generation of local high potential zone and induce the chain degradation at more points. So it was found that the porous chitin film could load Cu2O and graphene at the same time, controlling the size of Cu2O and leading to easy recycle and reuse of the photocatalyst. Moreover, the introduction of GO has dramatically improved the photocatalytic activity of Cu2O in the Cu2O/GO/RC film, showing great potential application in wastewater treatment utilizing solar energy.

  10. Mycorrhiza symbiosis increases the surface for sunlight capture in Medicago truncatula for better photosynthetic production.

    Directory of Open Access Journals (Sweden)

    Lisa Adolfsson

    Full Text Available Arbuscular mycorrhizal (AM fungi play a prominent role in plant nutrition by supplying mineral nutrients, particularly inorganic phosphate (Pi, and also constitute an important carbon sink. AM stimulates plant growth and development, but the underlying mechanisms are not well understood. In this study, Medicago truncatula plants were grown with Rhizophagus irregularis BEG141 inoculum (AM, mock inoculum (control or with P(i fertilization. We hypothesized that AM stimulates plant growth through either modifications of leaf anatomy or photosynthetic activity per leaf area. We investigated whether these effects are shared with P(i fertilization, and also assessed the relationship between levels of AM colonization and these effects. We found that increased P(i supply by either mycorrhization or fertilization led to improved shoot growth associated with increased nitrogen uptake and carbon assimilation. Both mycorrhized and P(i-fertilized plants had more and longer branches with larger and thicker leaves than the control plants, resulting in an increased photosynthetically active area. AM-specific effects were earlier appearance of the first growth axes and increased number of chloroplasts per cell section, since they were not induced by P(i fertilization. Photosynthetic activity per leaf area remained the same regardless of type of treatment. In conclusion, the increase in growth of mycorrhized and P(i-fertilized Medicago truncatula plants is linked to an increase in the surface for sunlight capture, hence increasing their photosynthetic production, rather than to an increase in the photosynthetic activity per leaf area.

  11. A comparison of hip fracture incidence rates among elderly in Sweden by latitude and sunlight exposure.

    Science.gov (United States)

    Nilson, Finn; Moniruzzaman, Syed; Andersson, Ragnar

    2014-03-01

    Research has shown that hip fracture risk increases with latitude; hypothetically due to reduced sunlight exposure and its effect on bone quality. Sweden, with large differences in latitude and UV radiation, is ideal to study in order to analyse the association between latitude and UV radiation on age- and sex-specific hip fracture rates among elderly. Aggregated (2006-2008) age- and sex-specific hip fracture data was obtained for each Swedish municipality as well as the municipality's latitudinal coordinates and aggregated (2006-2008) UV radiation levels. Pearson correlations were calculated between hip fracture incidence rates, latitude and UV radiation. Independent t tests were calculated on tertile-categorized latitudinal data in order to investigate the difference in hip fracture risk between these categories. Statistically significant correlations were seen in all groups between hip fracture incidence rates and latitude as well as UV radiation. The independent t tests showed that this correlation was mainly due to high incidence rates in high latitude municipalities. Statistically significant correlations are seen between hip fracture incidence rates and latitude as well as UV radiation in Sweden and the northern parts of Sweden have an increased risk of hip fractures compared to the middle and southern parts. To our knowledge this is the first study using a national discharge register that shows this relationship and provides a starting point for further research to investigate why populations in northern Sweden have a higher risk of hip fractures compared to other Swedish regions.

  12. Seasonal effects on pterygium surgery outcome: implications for the role of sunlight exposure.

    Science.gov (United States)

    Sul, Sabahattin; Korkmaz, Şafak; Novruzlu, Şahin

    2014-05-01

    The aim of this study was to compare the results of pterygium surgery in patients when performed in the summer with the results of surgery performed in the winter. This retrospective study enrolled 55 eyes of 53 patients with primary pterygia who underwent a surgery between December 2011 and January 2012 (winter group, 32 eyes) or between June and July 2012 (summer group, 23 eyes). All the patients were followed up for at least 1 year. Pterygium recurrence, ocular discomfort, persistent conjunctival inflammation, and graft complications were evaluated postoperatively. There was no significant difference between the groups in terms of age or gender. All the patients were farmers in rural areas. The overall pterygium recurrence rate was 14.5% (8 of 55 eyes). The recurrence rate in the summer group was significantly higher than in the winter group (26.1% vs. 6.2%, P = 0.048). Persistent conjunctival inflammation was also significantly higher in the summer group than in the winter group (30.4% vs. 6.2%, P = 0.022). Pterygium recurrence was significantly higher in eyes with persistent conjunctival inflammation than in eyes without inflammation (66.6% vs. 4.3%, P exposure to sunlight during the summer.

  13. Effect of preadmission sunlight exposure on intensive care unit-acquired delirium: a multicenter study.

    Science.gov (United States)

    Simons, Koen S; Workum, Jessica D; Slooter, Arjen J C; van den Boogaard, Mark; van der Hoeven, Johannes G; Pickkers, Peter

    2014-04-01

    It is assumed that there is a relation between light exposure and delirium incidence. The aim of our study was to determine the effect of prehospital light exposure on the incidence of intensive care unit (ICU)-acquired delirium. Data from 3 ICUs in the Netherlands were analyzed retrospectively. Delirium was assessed with the Confusion Assessment Method for the ICU. Daily light intensity data were obtained from meteorological stations in the vicinity of the 3 hospitals. The association between light intensity and delirium incidence was analyzed using logistic regression analysis adjusting for known covariates for delirium. Data of 3198 patients, aged (mean ± SD) 61.9 ± 15.3 years with Acute Physiology and Chronic Health Evaluation II score 16.4 ± 6.6 were analyzed. Delirium incidence was 31.2% and did not vary significantly throughout the year. Twenty-eight-day preadmission photoperiod was highest in spring and lowest in winter; however, no association between light exposure and delirium incidence was found (odds ratio, 1.00; 95% confidence interval, 0.99-1.00; P = 0.72). Furthermore, delirium was significantly associated with age, infection, use of sedatives, Acute Physiology and Chronic Health Evaluation II score, and diagnosis of neurological disease or trauma. The incidence of delirium does not differ per season and prior sunlight exposure does not play a role of importance in the development of ICU-acquired delirium. Copyright © 2014 Elsevier Inc. All rights reserved.

  14. Photolysis of Antibiotics under Simulated Sunlight Irradiation: Identification of Photoproducts by High-Resolution Mass Spectrometry.

    Science.gov (United States)

    Baena-Nogueras, Rosa María; González-Mazo, Eduardo; Lara-Martín, Pablo A

    2017-02-28

    There is growing concern regarding the widespread use of antibiotics and their presence in the aqueous environment. Their removal in the water column is mediated by different types of degradation processes for which the mechanisms are still unclear. This research is focused on characterizing the photodegradation kinetics and pathways of two largely employed antibiotics families: sulfonamides (9 SDs) and fluoroquinolones (6 FQs). Degradation percentages and rates were measured in pure water exposed to simulated natural sunlight at a constant irradiance value (500 W m(-2)) during all the experiments, and the main photoproducts formed were characterized through accurate mass measurement using ultraperformance liquid chromatography-quadrupole-time-of-flight-mass spectrometry (UPLC-QToF-MS). Over 200 different phototransformation products were identified for SDs and FQs, 66% of them, to the best of our knowledge, have not been described before. Their sequential formation and disappearance over the course of the experiments reveals the existence of several pathways for the degradation of target antibiotics. Occurrence of new photoproducts derived from desulfonation and/or denitrification, as well as hydroxylation of photo-oxidized heterocyclic rings, have been identified during photodegradation of SDs, whereas a new pathway yielding oxidation of the benzene ring after the cleavage of the piperazine ring (e.g., CIP product with m/z 280) is described for FQs.

  15. On identifying the specular reflection of sunlight in earth-monitoring satellite data.

    Energy Technology Data Exchange (ETDEWEB)

    Nelsen, James M., Jr.; Hohlfelder, Robert James; Jackson, Dale Clayton; Longenbaugh, Randolph S.

    2009-03-01

    Among the background signals commonly seen by Earth-monitoring satellites is the specular reflection of sunlight off of Earth's surface, commonly referred to as a glint. This phenomenon, involving liquid or ice surfaces, can result in the brief, intense illumination of satellite sensors appearing from the satellite perspective to be of terrestrial origin. These glints are important background signals to be able to identify with confidence, particularly in the context of analyzing data from satellites monitoring for transient surface or atmospheric events. Here we describe methods for identifying glints based on the physical processes involved in their production, including spectral fitting and polarization measurements. We then describe a tool that, using the WGS84 spheroidal Earth model, finds the latitude and longitude on Earth where a reflection of this type could be produced, given input Sun and satellite coordinates. This tool enables the user to determine if the surface at the solution latitude and longitude is in fact reflective, thus identifying the sensor response as a true glint or an event requiring further analysis.

  16. Photodegradation of malachite green under natural sunlight irradiation: kinetic and toxicity of the transformation products.

    Science.gov (United States)

    Pérez-Estrada, L A; Agüera, A; Hernando, M D; Malato, S; Fernández-Alba, A R

    2008-02-01

    This article describes the photolytic degradation of malachite green (MG), a cationic triphenylmethane dye used worldwide as a fungicide and antiseptic in the aquaculture industry. Photolysis experiments were performed by direct exposure of a solution of MG in water to natural sunlight. The main transformation products (TPs) generated during the process were identified by liquid chromatography time-of-flight mass spectrometry (LC-TOF-MS) and gas chromatography mass spectrometry (GC-MS). The 28 TPs identified with this strategy indicate that MG undergoes three main reactions, N-demethylation, hydroxylation and cleavage of the conjugated structure forming benzophenone derivatives. These processes involve hydroxyl radical attack on the phenyl ring, the N,N-dimethylamine group and the central carbon atom. The Vibrio fischeri acute toxicity test showed that the solution remains toxic after MG has completely disappeared. This toxicity could be assigned, at least in part, to the formation of 4-(dimethylamine)benzophenone, which has an EC(50,30 min) of 0.061 mg l(-1), and is considered "very toxic to aquatic organisms" by current EU legislation.

  17. Degradation of the pesticide carbofuran on clay and soil surfaces upon sunlight exposure.

    Science.gov (United States)

    Mountacer, H; Atifi, A; Wong-Wah-Chung, P; Sarakha, M

    2014-03-01

    In the present study, the photolysis of carbofuran has been undertaken under sunlight conditions and at the surface of model supports such as clay films and different soils collected from two different sites in Morocco (Tirs and Dahs). In all conditions, an efficient degradation occurred owing to direct light absorption and also to photoinduced processes involving either clays or natural organic matter moities. On kaolin films, the photodegradation kinetics appears to follow a first-order process that clearly depends on the film thickness. The diffusion of carbofuran from the lower part to the illuminated surface was found to be negligible when compared to the photolysis process within the range of 20-70 μm. Thus, the photolysis rate constant at the surface of the solid support, k (0), was evaluated to be 7.0 × 10(-3) min(-1). Under these experimental conditions, the quantum yield was found equal to 2.1 × 10(-4). On soil surfaces, the disappearance rate constant was mainly attributed to photoinduced processes arising from natural organic matter. From the analytical point of view, the products were formed through (1) hydroxylation on the aromatic ring, (2) homolytic scission of the carbamate C-O bond leading to radical species formation, and (3) photohydrolysis of the carbamate C-O bond.

  18. Sunlight-Driven Hydrogen Formation by Membrane-Supported Photoelectrochemical Water Splitting

    Energy Technology Data Exchange (ETDEWEB)

    Lewis, Nathan S. [California Institute of Technology

    2014-03-26

    This report describes the significant advances in the development of the polymer-supported photoelectrochemical water-splitting system that was proposed under DOE grant number DE-FG02-05ER15754. We developed Si microwire-array photoelectrodes, demonstrated control over the material and light-absorption properties of the microwire-array photoelectrodes, developed inexpensive processes for synthesizing the arrays, and doped the arrays p-type for use as photocathodes. We also developed techniques for depositing metal-nanoparticle catalysts of the hydrogen-evolution reaction (HER) on the wire arrays, investigated the stability and catalytic performance of the nanoparticles, and demonstrated that Ni-Mo alloys are promising earth-abundant catalysts of the HER. We also developed methods that allow reuse of the single-crystalline Si substrates used for microwire growth and methods of embedding the microwire photocathodes in plastic to enable large-scale processing and deployment of the technology. Furthermore we developed techniques for controlling the structure of WO3 films, and demonstrated that structural control can improve the quantum yield of photoanodes. Thus, by the conclusion of this project, we demonstrated significant advances in the development of all components of a sunlight-driven membrane-supported photoelectrochemical water-splitting system. This final report provides descriptions of some of the scientific accomplishments that were achieved under the support of this project and also provides references to the peer-reviewed publications that resulted from this effort.

  19. The sensitivity to polarization in stratospheric aerosol retrievals from limb scattered sunlight measurements

    Science.gov (United States)

    Elash, B. J.; Bourassa, A. E.; Rieger, L. A.; Dueck, S. R.; Zawada, D. J.; Degenstein, D. A.

    2017-03-01

    Satellite measurements of limb scattered sunlight at visible and near infrared wavelengths have been used successfully for several years to retrieve the vertical profile of stratospheric aerosol extinction coefficient. The existing satellite measurements are of the total radiance, with very little knowledge or impact of the polarization state of the limb radiance. Recently proposed instrument concepts for stratospheric aerosol profiling have been designed to measure the linearly polarized radiance. Yet, to date, the impact of the polarized measurement on the retrievals has not been systematically studied. Here we use a fully spherical, multiple scattering radiative transfer model to perform a sensitivity study on the effects of the polarized measurement on stratospheric aerosol extinction retrievals through specific investigations of the aerosol signal fraction in polarized measurements, potential retrieval bias, and achievable precision. In this study,we simulate both total and linearly polarized measurements, for a wide range of limb viewing geometries that are encountered in typical low earth orbits and for various aerosol loading scenarios. The orientation of the linear polarization with respect to the horizon is also studied. Taking into account instrument signal to noise levels it is found that in general, the linear polarization can be used as effectively as the total radiance measurement, with consideration of instrument signal to noise capabilities; however the horizontal polarization is more promising in terms of signal magnitude.

  20. Mycorrhiza symbiosis increases the surface for sunlight capture in Medicago truncatula for better photosynthetic production.

    Science.gov (United States)

    Adolfsson, Lisa; Solymosi, Katalin; Andersson, Mats X; Keresztes, Áron; Uddling, Johan; Schoefs, Benoît; Spetea, Cornelia

    2015-01-01

    Arbuscular mycorrhizal (AM) fungi play a prominent role in plant nutrition by supplying mineral nutrients, particularly inorganic phosphate (Pi), and also constitute an important carbon sink. AM stimulates plant growth and development, but the underlying mechanisms are not well understood. In this study, Medicago truncatula plants were grown with Rhizophagus irregularis BEG141 inoculum (AM), mock inoculum (control) or with P(i) fertilization. We hypothesized that AM stimulates plant growth through either modifications of leaf anatomy or photosynthetic activity per leaf area. We investigated whether these effects are shared with P(i) fertilization, and also assessed the relationship between levels of AM colonization and these effects. We found that increased P(i) supply by either mycorrhization or fertilization led to improved shoot growth associated with increased nitrogen uptake and carbon assimilation. Both mycorrhized and P(i)-fertilized plants had more and longer branches with larger and thicker leaves than the control plants, resulting in an increased photosynthetically active area. AM-specific effects were earlier appearance of the first growth axes and increased number of chloroplasts per cell section, since they were not induced by P(i) fertilization. Photosynthetic activity per leaf area remained the same regardless of type of treatment. In conclusion, the increase in growth of mycorrhized and P(i)-fertilized Medicago truncatula plants is linked to an increase in the surface for sunlight capture, hence increasing their photosynthetic production, rather than to an increase in the photosynthetic activity per leaf area.

  1. Sunlight and Vitamin D: The Bone and Cancer Connections (invited paper)

    Energy Technology Data Exchange (ETDEWEB)

    Holick, M.F

    2000-07-01

    Vitamin D plays an essential role for calcium metabolism and bone health. It has been estimated that 90 to 95% of our vitamin D requirement comes from casual exposure to sunlight. There is a wide variety of factors that strongly influence the cutaneous production of vitamin D. These include melanin pigmentation, latitude, time of day, sunscreen use, and aging. There is an association with increased risk and mortality to breast, colon, and prostrate cancer. There is evidence that 25-hydroxyvitamin D, the major circulating form of vitamin D, is directly metabolised in prostate, breast, colon, and skin cells to its active form 1,25-dihydroxyvitamin D. 1,25-Dihydroxyvitamin D{sub 3} has the capacity to regulate cell proliferation and differentiation. Therefore, it may be that an increase in the cutaneous synthesis of vitamin D results in the increase in the production of 1,25(OH){sub 2}D in tissues not related to calcium metabolism that results in a decrease in malignancy. (author)

  2. Nanostructured photosystems for the generation of electricity and fuels from sunlight

    Science.gov (United States)

    Grätzel, Michael

    2013-03-01

    Learning from the concepts used by green plants photosynthesis, we have developed nanostructured systems affording efficient solar light harvesting and conversion to electricity and fuels. Solar cells using dyes or semiconducting nanoparticles as light harvesters supported by mesoscopic oxide films have emerged as credible contenders to conventional p-n junction photovoltaic devices. Separating light absorption from charge carrier transport dye sensitized mesoscopic solar cells (DSCs) were the first to use a three-dimensional nanocrystalline junction for solar electricity production. The standard AM 1.5 solar to electric power conversion efficiency (PCE) has reached 12.9% for laboratory cells and 9.9% for PV modules. Even higher efficiencies are attained under ambient and indoor light conditions. These features along with excellent long-term stability have fostered first commercial applications, the industrial production of DSC's attaining presently the MW/year scale. Very exciting results have recently been obtained with perovskites and quantum dot particles as light harvesters in mesoscopic solar cells. Striking advances in the direct generation of fuels such as hydrogen from water and sunlight have been achieved by the judicious design of photosystems composed of nanostructured Fe2O3 or Cu2O films.

  3. Psychosocial aspects associated with use of sunscreen, natural sunlight exposure, and artificial tanning.

    Science.gov (United States)

    Ventenilla, Jessica; França, Katlein; Lotti, Torello; Keri, Jonette

    2017-02-08

    Natural and artificial tanning have become very popular in Western culture, yet at the same time, there is still a psychodermatology concern for this activity. Not much has been examined with the psychological aspects of tanning and sunscreen use. The purpose of this study is to examine the psychosocial effects associated with sun protection, natural, and artificial tanning among individuals 18 years old or older visiting the University of Miami Dermatology Outpatient Clinic. We distributed a survey on tanning and sunscreen use to 150 dermatology outpatients, hospital employees, and hospital visitors for three weeks during June/July 2015 asking about how often they tan, use sunscreen, and how they feel about this topic. Demographics, such as gender, ethnicity, and education were taken into consideration to examine the different responses in each category. Our results suggest that people's perception to tanning and sunscreen use have evolved over time. Most people in South Florida nowadays feel guilty when exposed to natural sunlight without sunscreen and do not tan frequently. The majority of the people, specifically women, utilize the recommended amount of sunscreen with a sun protection factor of 30-50. However, we can conclude that communication between social media and the general public can affect people's decision-making on tanning and sunscreen use with physician advice being the most effective method of encouraging people to use sunscreen. This study will add to the growing knowledge about psychodermatology.

  4. 2016 Annual Technology Baseline (ATB)

    Energy Technology Data Exchange (ETDEWEB)

    Cole, Wesley; Kurup, Parthiv; Hand, Maureen; Feldman, David; Sigrin, Benjamin; Lantz, Eric; Stehly, Tyler; Augustine, Chad; Turchi, Craig; O' Connor, Patrick; Waldoch, Connor

    2016-09-01

    Consistent cost and performance data for various electricity generation technologies can be difficult to find and may change frequently for certain technologies. With the Annual Technology Baseline (ATB), National Renewable Energy Laboratory provides an organized and centralized dataset that was reviewed by internal and external experts. It uses the best information from the Department of Energy laboratory's renewable energy analysts and Energy Information Administration information for conventional technologies. The ATB will be updated annually in order to provide an up-to-date repository of current and future cost and performance data. Going forward, we plan to revise and refine the values using best available information. The ATB includes both a presentation with notes (PDF) and an associated Excel Workbook. The ATB includes the following electricity generation technologies: land-based wind; offshore wind; utility-scale solar PV; concentrating solar power; geothermal power; hydropower plants (upgrades to existing facilities, powering non-powered dams, and new stream-reach development); conventional coal; coal with carbon capture and sequestration; integrated gasification combined cycle coal; natural gas combustion turbines; natural gas combined cycle; conventional biopower. Nuclear laboratory's renewable energy analysts and Energy Information Administration information for conventional technologies. The ATB will be updated annually in order to provide an up-to-date repository of current and future cost and performance data. Going forward, we plan to revise and refine the values using best available information.

  5. Concentration device

    DEFF Research Database (Denmark)

    2013-01-01

    A concentration device (2) for filter filtration concentration of particles (4) from a volume of a fluid (6). The concentration device (2) comprises a filter (8) configured to filter particles (4) of a predefined size in the volume of the fluid (6). The concentration device (2) comprises...

  6. Optimal concentration and temperatures of solar thermal power plants

    OpenAIRE

    2012-01-01

    Using simple, finite-time, thermodynamic models of solar thermal power plants, the existence of an optimal solar receiver temperature has previously been demonstrated in literature. Scant attention has been paid, however, to the presence of an optimal level of solar concentration at which the conversion of incident sunlight to electricity (solar-to-electric efficiency) is maximized. This paper addresses that gap. The paper evaluates the impact, on the design of Rankine-cycle solar-trough and ...

  7. Effect of humic acids and sunlight on the cytotoxicity of engineered zinc oxide and titanium dioxide nanoparticles to a river bacterial assemblage

    Institute of Scientific and Technical Information of China (English)

    Thabitha P.Dasari; Huey-Min Hwang

    2013-01-01

    The effect of a terrestrial humic acid (HA) and Suwannee River HA on the cytotoxicity of engineered zinc oxide nanoparticles (ZnONPs)and titanium dioxide nanoparticles (TiO2NPs) to natural aquatic bacterial assemblages was measured with spread plate counting.The effect of HA (10 and 40 ppm) on the cytotoxicity of ZnONPs and TiO2NPs was tested factorially in the presence and absence of natural sunlight (light irradiation (LI)).The experiment was of full factorial,completely randomized design and the results were analyzed using the General Linear Model in SAS analytical software.The method of least squares means was used to separate the means or combinations of means.We determined the mechanism of toxicity via measurements of oxidative stress and metal ions.The toxicity of ZnONPs and TiO2NPs to natural aquatic bacterial assemblages appears to be concentration dependent.Moreover,the cytotoxicity of ZnONPs and TiO2NPs appeared to be affected by HA concentration,the presence of sunlight irradiation,and the dynamic multiple interactions among these factors.With respect to light versus darkness in the control group,the data indicate that bacterial viability was inhibited more in the light exposure than in the darkness exposure.The same was true in the HA treatment groups.With respect to terrestrial versus Suwanee River HA for a given nanoparticle,in light versus darkness,bacterial viability was more inhibited in the light treatment groups containing the terrestrial HA than in those containing Suwanee River HA.Differences in the extent of reactive oxygen species formation,adsorption/binding of ZnONPs/TiO2NPs by HA,and the levels of free metal ions were speculated to account for the observed cytotoxicity.TEM images indicate the attachment and binding of the tested nanoparticles to natural bacterial assemblages.Besides the individual parameter,significant effects on bacterial viability count were also observed in the following combined treatments

  8. Porous graphitic carbon nitride synthesized via direct polymerization of urea for efficient sunlight-driven photocatalytic hydrogen production.

    Science.gov (United States)

    Zhang, Yuewei; Liu, Jinghai; Wu, Guan; Chen, Wei

    2012-09-07

    Energy captured directly from sunlight provides an attractive approach towards fulfilling the need for green energy resources on the terawatt scale with minimal environmental impact. Collecting and storing solar energy into fuel through photocatalyzed water splitting to generate hydrogen in a cost-effective way is desirable. To achieve this goal, low cost and environmentally benign urea was used to synthesize the metal-free photocatalyst graphitic carbon nitride (g-C₃N₄). A porous structure is achieved via one-step polymerization of the single precursor. The porous structure with increased BET surface area and pore volume shows a much higher hydrogen production rate under simulated sunlight irradiation than thiourea-derived and dicyanamide-derived g-C₃N₄. The presence of an oxygen atom is presumed to play a key role in adjusting the textural properties. Further improvement of the photocatalytic function can be expected with after-treatment due to its rich chemistry in functionalization.

  9. Plant uptake-assisted round-the-clock photocatalysis for complete purification of aquaculture wastewater using sunlight.

    Science.gov (United States)

    Bian, Zhenfeng; Cao, Fenglei; Zhu, Jian; Li, Hexing

    2015-02-17

    A novel reactor equipped with solar batteries, Bi2O3/TiO2 film photocatalyst, and celery plant was designed and used for purification of aquaculture wastewater. The Bi2O3/TiO2 film photocatalyst started photocatalytic degradation of organonitrogen compounds under irradiation of sunlight. Meanwhile, the solar batteries absorbed and converted excess sunlight into electric energy and then started UV lamps at night, leading to round-the-clock photocatalysis. Subsequently, the inorganic nitrogen species including NH4(+), NO2(-), and NO3(-) resulting from photocatalytic degradation of the organonitrogen compounds could subsequently be uptaken by the celery plant as the fertilizer to reduce the secondary pollution. It was found that, after 24 h circulation, both organonitrogen compounds and NO2(-) species were completely removed, while NH4(+) and NO3(-) contents also decreased by 30% and 50%, respectively. The reactor could be used repetitively, showing a good potential in practical application.

  10. Concentrated Ownership

    DEFF Research Database (Denmark)

    Rose, Caspar

    2014-01-01

    , especially minority shareholders. Concentrated ownership is associated with benefits and costs. Concentrated ownership may reduce agency costs by increased monitoring of top management. However, concentrated ownership may also provide dominating owners with private benefits of control.......This entry summarizes the main theoretical contributions and empirical findings in relation to concentrated ownership from a law and economics perspective. The various forms of concentrated ownership are described as well as analyzed from the perspective of the legal protection of investors...

  11. Sunlight exposure and cutaneous human papillomavirus seroreactivity in basal cell and squamous cell carcinomas of the skin.

    Science.gov (United States)

    Iannacone, Michelle R; Wang, Wei; Stockwell, Heather G; O'Rourke, Kathleen; Giuliano, Anna R; Sondak, Vernon K; Messina, Jane L; Roetzheim, Richard G; Cherpelis, Basil S; Fenske, Neil A; Michael, Kristina M; Waterboer, Tim; Pawlita, Michael; Rollison, Dana E

    2012-08-01

    Ultraviolet radiation exposure may interact synergistically with cutaneous human papillomavirus (HPV) infection in the development of basal cell carcinoma (BCC) and squamous cell carcinoma (SCC) of the skin. To investigate differences in the risk of sunlight-associated BCC and SCC by cutaneous genus-specific HPV serostatus, a case-control study was conducted among 204 BCC and 156 SCC cases who were recruited from a university dermatology clinic and 297 controls who had no history of cancer and screened negative for current skin cancer. Logistic regression was used to calculate odds ratios (ORs) and 95% confidence intervals (CIs) for the associations between measures of sunlight exposure and BCC/SCC, stratified by genus-specific HPV serostatus, with adjustment for age and sex. Sunburn due to cutaneous sensitivity to sunlight exposure (P = .006) and poor tanning ability (P = .003) were associated with a higher seroprevalence for genus beta HPV types. Poor or no tanning ability was more strongly associated with SCC among individuals who were seropositive for antibodies to cutaneous HPV types in genera alpha (OR, 15.60; 95% CI, 5.40-45.1; P = .01 for interaction) and beta (OR, 6.86; 95% CI, 3.68-12.80; P = .001 for interaction), compared with individuals who were seronegative for these HPV types. Seropositivity for HPV types in genera alpha or beta increased the risk of SCC associated with poor tanning ability.

  12. Cellular and molecular mechanism of ofloxacin induced apoptotic cell death under ambient UV-A and sunlight exposure.

    Science.gov (United States)

    Dwivedi, A; Mujtaba, S F; Yadav, N; Kushwaha, H N; Amar, S K; Singh, S K; Pant, M C; Ray, R S

    2014-03-01

    Ofloxacin (OFLX) is a racemic mixture of levofloxacin which revealed phototoxicity in patients exposed with sunlight after medication. Here, we have been addressed the possible cellular and molecular mechanisms of OFLX induced apoptosis under ambient UV-A and sunlight exposure using HaCaT cell line as a model. The results showed that Photodegradation and three photo-products formation of OFLX by LC-MS/MS under ambient intensities of UV-A (1.5 and 2.2 mW/cm(2)) and sunlight. OFLX produced (1)O2, O2(.-), and OH radicals via type-II- and type-I-dependent reaction mechanism, which corroborated by its specific quenchers. 2'-dGua degradation in photochemical and % tail DNA formation in cell line using comet test advocated the genotoxic potential of OFLX. Photocytotoxic assays (MTT and NRU) revealed the considerable decline in cell viability by OFLX. OFLX triggered apoptosis, proved by cell cycle, Annexin V/PI double staining along with acridine orange (AO)/ethidium bromide (EB), and Hoechst staining as well as caspase-3 activity by colorimetric assay. OFLX induced lysosomal disruption and mitochondrial membrane destabilization confirmed through fluorescence staining with AO/JC-1. OFLX significantly upregulated the expression of p21 and bax genes. In conclusion, the study revealed that photosensitized OFLX induced apoptosis via ROS-mediated DNA damage, destabilization of lysosomal and mitochondrial membrane, and upregulation of p21, bax, and caspase-3 genes.

  13. Photocatalytic degradation of Orange G on nitrogen-doped TiO2 catalysts under visible light and sunlight irradiation.

    Science.gov (United States)

    Sun, Jianhui; Qiao, Liping; Sun, Shengpeng; Wang, Guoliang

    2008-06-30

    In this paper, the degradation of an azo dye Orange G (OG) on nitrogen-doped TiO2 photocatalysts has been investigated under visible light and sunlight irradiation. Under visible light irradiation, the doped TiO2 nanocatalysts demonstrated higher activity than the commercial Dugussa P25 TiO2, allowing more efficient utilization of solar light, while under sunlight, P25 showed higher photocatalytic activity. According to the X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and UV-vis spectra analyses, it was found that both the nanosized anatase structure and the appearance of new absorption band in the visible region caused by nitrogen doping were responsible for the significant enhancement of OG degradation under visible light. In addition, the photosensitized oxidation mechanism originated from OG itself was also considered contributing to the higher visible-light-induced degradation efficiency. The effect of the initial pH of the solution and the dosage of hydrogen peroxide under different light sources was also investigated. Under visible light and sunlight, the optimal solution pH was both 2.0, while the optimal dosage of H2O2 was 5.0 and 15.0 mmol/l, respectively.

  14. Decoloring Methyl Orange under Sunlight by a Photocatalytic Membrane Reactor Based on ZnO Nanoparticles and Polypropylene Macroporous Membrane

    Directory of Open Access Journals (Sweden)

    Bing Hu

    2013-01-01

    Full Text Available Decoloring methyl orange (MeOr under sunlight was conducted in a photocatalytic membrane reactor (PMR. Zinc oxide nanoparticles (ZnO NPs were suspended in the solution or immobilized on the membrane. The membrane was modified by grafting 2-hydroxyethyl methacrylate (HEMA to enhance the adsorption of ZnO NPs on the hydrophobic membrane surface and improve the membrane permeability. The results show that the water fluxes through the modified membranes are higher than that through the unmodified membrane. After introducing ZnO NPs to the membrane, the water fluxes still rise with the immobilization degree of ZnO NPs. For the PMR with ZnO NPs in suspension, the photocatalytic decoloration percent (PDP was over 98.2% after 40 min under sunlight. For the PMR with ZnO NPs immobilized on the membrane, the max of PDP was 74.3% after 6 h under sunlight, and maintained at 72% after repeated uses for five times. These results demonstrate that photocatalytic membrane reactor (PMR based on ZnO NPs and polypropylene macroporous membrane(PPMM could be applied in decoloring dyes.

  15. Daytime Cognitive Performance in Response to Sunlight or Fluorescent Light Controlling for Sleep Duration

    Science.gov (United States)

    Ramos, Jhanic; Zamos, Adela; Rao, Rohit; Flynn-Evans, Erin

    2015-01-01

    Light is the primary synchronizer of the human circadian rhythm and also has acute alerting effects. Our study involves and comparing the alertness, performance and sleep of participants in the NASA Ames Sustainability Base, which uses sunlight as its primary light source, to in a traditional office building which uses overhead florescent lighting and varying exposure to natural light. The purpose of this study is to determine whether the use of natural lighting as a primary light source improves daytime cognitive function and promotes nighttime sleep. Participants from the Sustainability Base will be matched by gender and age to individuals working in other NASA buildings. In a prior study we found no differences in performance between those working in the Sustainability Base and those working in other buildings. Unexpectedly, we found that the average sleep duration among participants in both buildings was short, which likely obscured our ability to detect a difference the effect of light exposure on alertness. Given that such sleep deprivation has negative effects on cognitive performance, in this iteration of the study we are asking the participants to maintain a regular schedule with eight hours in bed each night in order to control for the effect of self-selected sleep restriction. Over the course of one week, we will ask the participants to wear actiwatches continuously, complete a psychomotor vigilance task (PVT) and digit symbol substitution task (DSST) three times per day, and keep daily sleepwork diaries. We hope that this study will provide data to support the idea that natural lighting and green architectural design are optimal to enhance healthy nighttime sleep patterns and daytime cognitive performance.

  16. Measurements of pulse rate using long-range imaging photoplethysmography and sunlight illumination outdoors

    Science.gov (United States)

    Blackford, Ethan B.; Estepp, Justin R.

    2017-02-01

    Imaging photoplethysmography, a method using imagers to record absorption variations caused by microvascular blood volume pulsations, shows promise as a non-contact cardiovascular sensing technology. The first long-range imaging photoplethysmography measurements at distances of 25, 50, and 100 meters from the participant was recently demonstrated. Degraded signal quality was observed with increasing imager-to-subject distances. The degradation in signal quality was hypothesized to be largely attributable to inadequate light return to the image sensor with increasing lens focal length. To test this hypothesis, a follow-up evaluation with 27 participants was conducted outdoors with natural sunlight illumination resulting in 5-33 times the illumination intensity. Video was recorded from cameras equipped with ultra-telephoto lenses and positioned at distances of 25, 50, 100, and 150 meters. The brighter illumination allowed high-definition video recordings at increased frame rates of 60fps, shorter exposure times, and lower ISO settings, leading to higher quality image formation than the previous indoor evaluation. Results were compared to simultaneous reference measurements from electrocardiography. Compared to the previous indoor study, we observed lower overall error in pulse rate measurement with the same pattern of degradation in signal quality with respect to increasing distance. This effect was corroborated by the signal-to-noise ratio of the blood volume pulse signal which also showed decreasing quality with respect to increasing distance. Finally, a popular chrominance-based method was compared to a blind source separation approach; while comparable in measurement of signal-to-noise ratio, we observed higher overall error in pulse rate measurement using the chrominance method in this data.

  17. Sensitivity Studies for Space-based Measurements of Atmospheric Total Column Carbon Dioxide Using Reflected Sunlight

    Science.gov (United States)

    Mao, Jianping; Kawa, S. Randolph

    2003-01-01

    A series of sensitivity studies is carried out to explore the feasibility of space-based global carbon dioxide (CO2) measurements for global and regional carbon cycle studies. The detection method uses absorption of reflected sunlight in the CO2 vibration-rotation band at 1.58 micron. The sensitivities of the detected radiances are calculated using the line-by-line model (LBLRTM), implemented with the DISORT (Discrete Ordinates Radiative Transfer) model to include atmospheric scattering in this band. The results indicate that (a) the small (approx.1%) changes in CO2 near the Earth's surface are detectable in this CO2 band provided adequate sensor signal-to-noise ratio and spectral resolution are achievable; (b) the effects of other interfering constituents, such as water vapor, aerosols and cirrus clouds, on the radiance are significant but the overall effects of the modification of light path length on total back-to-space radiance sensitivity to CO2 change are minor for general cases, which means that generally the total column CO2 can be derived in high precision from the ratio of the on-line center to off-line radiances; (c) together with CO2 gas absorption aerosol/cirrus cloud layer has differential scattering which may result in the modification of on-line to off-line radiance ratio which could lead a large bias in the total column CO2 retrieval. Approaches to correct such bias need further investigation. (d) CO2 retrieval requires good knowledge of the atmospheric temperature profile, e.g. approximately 1K RMS error in layer temperature, which is achievable from new atmospheric sounders in the near future; (e) the atmospheric path length, over which the CO2 absorption occurs, should be known in order to correctly interpret horizontal gradients of CO2 from the total column CO2 measurement; thus an additional sensor for surface pressure measurement needs to be attached for a complete measurement package.

  18. Degradation of DEET and Caffeine under UV/Chlorine and Simulated Sunlight/Chlorine Conditions.

    Science.gov (United States)

    Sun, Peizhe; Lee, Wan-Ning; Zhang, Ruochun; Huang, Ching-Hua

    2016-12-20

    Photoactivation of aqueous chlorine could promote degradation of chlorine-resistant and photochemically stable chemicals accumulated in swimming pools. This study investigated the degradation of two such chemicals, N,N-diethyl-3-methylbenzamide (DEET) and caffeine, by low pressure ultraviolet (UV) light and simulated sunlight (SS) activated free chlorine (FC) in different water matrices. Both DEET and caffeine were rapidly degraded by UV/FC and SS/FC but exhibited different kinetic behaviors. The degradation of DEET followed pseudo-first-order kinetics, whereas the degradation of caffeine accelerated with reaction. Mechanistic study revealed that, under UV/FC, ·OH and Cl· were responsible for degradation of DEET, whereas ClO· related reactive species (ClOrrs), generated by the reaction between FC and ·OH/Cl·, played a major role in addition to ·OH and Cl· in degrading caffeine. Reaction rate constants of DEET and caffeine with the respective radical species were estimated. The imidazole moiety of caffeine was critical for the special reactivity with ClOrrs. Water matrix such as pH had a stronger impact on the UV/FC process than the SS/FC process. In saltwater matrix under UV/FC and SS/FC, the degradation of DEET was significantly inhibited, but the degradation of caffeine was much faster than that in nonsalty solutions. The interaction between Br(-) and Cl(-) may play an important role in the degradation of caffeine by UV/FC in saltwater. Reaction product analysis showed similar product patterns by UV/FC and SS/FC and minimal formation of chlorinated intermediates and disinfection byproducts.

  19. A practical demonstration of water disinfection using TiO2 films and sunlight.

    Science.gov (United States)

    Gelover, Silvia; Gómez, Luis A; Reyes, Karina; Teresa Leal, Ma

    2006-10-01

    The scope of this study is the assessment of the efficiency of solar disinfection by heterogeneous photocatalysis with sol-gel immobilized (titanium dioxide) TiO2 films over glass cylinders. The solar disinfection process known as SODIS was considered as a reference. Spring water naturally polluted with coliform bacteria was exposed to sunlight in plastic bottles with and without TiO2 over simple solar collectors and the disinfection effectiveness was measured. Total and fecal coliforms quantification was performed by means of the chromogenic substrate method in order to obtain the efficiency of each disinfection treatment. The disinfection with TiO2 was more efficient than the SODIS process, inactivating total coliforms as well as fecal coliforms. On a sunny day (more than 1000 W m(-2) irradiance), it took the disinfection with immobilized TiO2 15 min of irradiation to inactivate the fecal coliforms to make them undetectable. For inactivation of total coliforms, 30 min was required, so that in less than half the time it takes SODIS, the treated water complies with the microbial standards for drinking water in Mexico. Another important part of this study has been to determine the bacterial regrowth in water after the disinfection processes were tested. After SODIS, bacterial regrowth of coliforms was observed. In contrast, when using the TiO2 catalyst, coliforms regrowth was not detected, neither for total nor for fecal coliforms. The disinfection process using TiO2 kept treated water free of coliforms at least for seven days after sun irradiation. This demonstration opens the possibility of application of this simple method in rural areas of developing countries.

  20. Antiradical capacity and polyphenol composition of asparagus spears varieties cultivated under diff erent sunlight conditions

    Directory of Open Access Journals (Sweden)

    Bartosz Kulczyński

    2016-09-01

    sunlight and variety. Asparagus can provide a valuable source of phenolic compounds in the human diet.

  1. USRDS - Annual Data Report

    Data.gov (United States)

    U.S. Department of Health & Human Services — United States Renal Data System (USRDS) Annual Data Report Comprehensive statistics on chronic kidney disease and end-stage renal diseases in the United States...

  2. 2010 Annual Report

    Energy Technology Data Exchange (ETDEWEB)

    None

    2010-01-01

    This annual report includes: an overview of Western; approaches for future hydropower and transmission service; major achievements in FY 2010; FY 2010 customer Integrated Resource Planning, or IRP, survey; and financial data.

  3. Annual General Meeting

    CERN Multimedia

    Staff Association

    2014-01-01

      STAFF ASSOCIATION Our next annual general meeting will take place on : Thursday 22 May 2014 at 11:00 AM Building 40-S2-D01 For further information visit our website : https://indico.cern.ch/event/313124/

  4. Annual General Canvass Statistics

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains annual quantities and value for all seafood products that are landed and sold by established seafood dealers and brokers in the Southeast...

  5. NIRE annual report 1999

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-07-01

    The National Institute for Resources and Environment (NIRE) has a R & D concept of 'ecotechnology' that aims to protect the environment from degradation whilst promoting sustainable development. This annual report presents summaries of 32 recent research efforts.

  6. ASIST 2002 annual meeting

    CERN Multimedia

    Peek, R

    2003-01-01

    Review of discussions and presentations at the American Society for Information Science and Technology 2002 annual meeting. Topics covered included new models of scholarly publishing and the development of the semantic web (1 page).

  7. Annual Trapping Proposal 1985

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This Annual Trapping Plan for the 1984-1985 trapping season at Clarence Cannon NWR outlines rules and regulations for the trapping of beaver and muskrat on the...

  8. SIS - Annual Catch Limit

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Annual Catch Limit (ACL) dataset within the Species Information System (SIS) contains information and data related to management reference points and catch data.

  9. Annual Adjustment Factors

    Data.gov (United States)

    Department of Housing and Urban Development — The Department of Housing and Urban Development establishes the rent adjustment factors - called Annual Adjustment Factors (AAFs) - on the basis of Consumer Price...

  10. Natural gas annual 1994

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-11-17

    The Natural Gas Annual provides information on the supply and disposition of natural gas to a wide audience including industry, consumers, Federal and State agencies, and educational institutions. The 1994 data are presented in a sequence that follows natural gas (including supplemental supplies) from its production to its end use. This is followed by tables summarizing natural gas supply and disposition from 1990 to 1994 for each Census Division and each State. Annual historical data are shown at the national level.

  11. Natural gas annual 1995

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-11-01

    The Natural Gas Annual provides information on the supply and disposition of natural gas to a wide audience including industry, consumers, Federal and State agencies, and educational institutions. The 1995 data are presented in a sequence that follows natural gas (including supplemental supplies) from its production to its end use. This is followed by tables summarizing natural gas supply and disposition from 1991 to 1995 for each Census Division and each State. Annual historical data are shown at the national level.

  12. Analysis of light guiding property in light piped based solar concentrator

    Science.gov (United States)

    Whang, Allen J.; Chuang, Chun-Hsien, Jr.; Chen, Yi-Yung

    2008-02-01

    Recently, many researchers have tried to design a system for indoor illumination because the benefits of solar systems. A simple parabolic reflector is often used to collect sunlight but the efficiency is poor when sunlight isn't incident normally. Therefore, an accurate machine to track sun has to be used. In order to get better tolerance, a light pipe based solar concentrator (LPBSC) which comprises a parabolic reflector and a hollow reflective light pipe is proposed. We develop a math model which combines the reflection times of sunlight in light pipe and the candela data of parabolic reflector to analyze the efficiency. And then, straight light pipe is replaced by tapered light pipe to improve the tolerance. Optical simulation software, TracePro, and mathematical software, MATLAB, are used to prove the model is correct and feasible. In the results, LPBSC can improve the tolerance to get good efficiency.

  13. Sunlight, Sea Ice, and the Ice Albedo Feedback in a Changing Artic Sea Ice Cover

    Science.gov (United States)

    2015-11-30

    Arctic sea ice cover and its impact on the heat and mass balance of the ice and upper ocean ... Arctic Ocean and surrounding seas, with particular emphasis on the Chukchi and Beaufort Seas. Some of the largest changes to the sea ice cover are...other parts of the Arctic ice cover appear to now be accelerating. Figure 6. Maps of the linear trend of annual solar heat input to the ocean

  14. Serum 25-hydroxyvitamin-D responses to multiple UV exposures from solaria: inferences for exposure to sunlight.

    Science.gov (United States)

    McKenzie, Richard; Scragg, Robert; Liley, Ben; Johnston, Paul; Wishart, John; Stewart, Alistair; Prematunga, Roshani

    2012-07-01

    We investigate the relationship between blood serum 25-hydroxyvitamin D (25(OH)D) and UV exposure from two artificial sources. We then use the results to test the validity of the action spectrum for vitamin D production, and to infer the production from summer and winter sunlight. The results are based on a two-arm randomised clinical trial of biweekly UV exposure for 12 weeks using two different types of dermatological booths: one emitting primarily UV-A radiation, and the other emitting primarily UV-B radiation (booth A and booth B respectively). In terms of the vitamin D production per unit erythema, one of the booths mimics summer noon sunlight, while the other mimics winter noon sunlight. Blood samples were taken before and after the exposures. For all participants, the phototherapy booth treatments arrested the usual wintertime decline in 25(OH)D, and for most the treatments from either booth resulted in significant increases. The increases were highly non-linear and there was a high degree of variability in 25(OH)D and its response to UV from person to person. By the end of the 12 week period, the mean increase was >30 nmol l(-1) from a cumulative exposure of 17 SED from the UV-A booth, and twice that for the UV-B booth for which the cumulative exposure was 268 SED. Assuming a logarithmic relationship between UV and vitamin D, the results for the two booths show no obvious inconsistency in the action spectrum for pre-vitamin D production. However, further measurements with similar exposures from each booth are required to confirm its validity. A model was developed to describe the increases in serum 25(OH)D resulting from the UV exposures, which differed markedly between the two booths. The deduced initial rate of increase of 25(OH)D was approximately 5 nmol l(-1) per SED. From the large increases in 25(OH)D from each booth, along with knowledge of the spectral distribution of sunlight and assuming the currently-accepted action spectrum for photo

  15. Sunlight Modulates Fruit Metabolic Profile and Shapes the Spatial Pattern of Compound Accumulation within the Grape Cluster

    Science.gov (United States)

    Reshef, Noam; Walbaum, Natasha; Agam, Nurit; Fait, Aaron

    2017-01-01

    Vineyards are characterized by their large spatial variability of solar irradiance (SI) and temperature, known to effectively modulate grape metabolism. To explore the role of sunlight in shaping fruit composition and cluster uniformity, we studied the spatial pattern of incoming irradiance, fruit temperature and metabolic profile within individual grape clusters under three levels of sunlight exposure. The experiment was conducted in a vineyard of Cabernet Sauvignon cv. located in the Negev Highlands, Israel, where excess SI and midday temperatures are known to degrade grape quality. Filtering SI lowered the surface temperature of exposed fruits and increased the uniformity of irradiance and temperature in the cluster zone. SI affected the overall levels and patterns of accumulation of sugars, organic acids, amino acids and phenylpropanoids, across the grape cluster. Increased exposure to sunlight was associated with lower accumulation levels of malate, aspartate, and maleate but with higher levels of valine, leucine, and serine, in addition to the stress-related proline and GABA. Flavan-3-ols metabolites showed a negative response to SI, whereas flavonols were highly induced. The overall levels of anthocyanins decreased with increased sunlight exposure; however, a hierarchical cluster analysis revealed that the members of this family were grouped into three distinct accumulation patterns, with malvidin anthocyanins and cyanidin-glucoside showing contrasting trends. The flavonol-glucosides, quercetin and kaempferol, exhibited a logarithmic response to SI, leading to improved cluster uniformity under high-light conditions. Comparing the within-cluster variability of metabolite accumulation highlighted the stability of sugars, flavan-3-ols, and cinnamic acid metabolites to SI, in contrast to the plasticity of flavonols. A correlation-based network analysis revealed that extended exposure to SI modified metabolic coordination, increasing the number of negative

  16. Dimethylsulfide Chemistry: Annual, Seasonal, and Spatial Impacts on Sulfate

    Science.gov (United States)

    We incorporated oceanic emissions and atmospheric chemistry of dimethylsulfide (DMS) into the hemispheric Community Multiscale Air Quality model and performed annual model simulations without and with DMS chemistry. The model without DMS chemistry predicts higher concentrations o...

  17. Concentration risk

    Directory of Open Access Journals (Sweden)

    Matić Vesna

    2016-01-01

    Full Text Available Concentration risk has been gaining a special dimension in the contemporary financial and economic environment. Financial institutions are exposed to this risk mainly in the field of lending, mostly through their credit activities and concentration of credit portfolios. This refers to the concentration of different exposures within a single risk category (credit risk, market risk, operational risk, liquidity risk.

  18. Ultraviolet Sunlight Exposure During Adolescence and Adulthood and Breast Cancer Risk: A Population-based Case-Control Study Among Ontario Women

    National Research Council Canada - National Science Library

    Anderson, Laura N; Cotterchio, Michelle; Kirsh, Victoria A; Knight, Julia A

    2011-01-01

    .... The associations among ultraviolet radiation from sunlight, factors related to cutaneous vitamin D production, and breast cancer risk were evaluated in a population-based case-control study conducted...

  19. Wafer integrated micro-scale concentrating photovoltaics

    Science.gov (United States)

    Gu, Tian; Li, Duanhui; Li, Lan; Jared, Bradley; Keeler, Gordon; Miller, Bill; Sweatt, William; Paap, Scott; Saavedra, Michael; Das, Ujjwal; Hegedus, Steve; Tauke-Pedretti, Anna; Hu, Juejun

    2017-09-01

    Recent development of a novel micro-scale PV/CPV technology is presented. The Wafer Integrated Micro-scale PV approach (WPV) seamlessly integrates multijunction micro-cells with a multi-functional silicon platform that provides optical micro-concentration, hybrid photovoltaic, and mechanical micro-assembly. The wafer-embedded micro-concentrating elements is shown to considerably improve the concentration-acceptance-angle product, potentially leading to dramatically reduced module materials and fabrication costs, sufficient angular tolerance for low-cost trackers, and an ultra-compact optical architecture, which makes the WPV module compatible with commercial flat panel infrastructures. The PV/CPV hybrid architecture further allows the collection of both direct and diffuse sunlight, thus extending the geographic and market domains for cost-effective PV system deployment. The WPV approach can potentially benefits from both the high performance of multijunction cells and the low cost of flat plate Si PV systems.

  20. Large scale water lens for solar concentration.

    Science.gov (United States)

    Mondol, A S; Vogel, B; Bastian, G

    2015-06-01

    Properties of large scale water lenses for solar concentration were investigated. These lenses were built from readily available materials, normal tap water and hyper-elastic linear low density polyethylene foil. Exposed to sunlight, the focal lengths and light intensities in the focal spot were measured and calculated. Their optical properties were modeled with a raytracing software based on the lens shape. We have achieved a good match of experimental and theoretical data by considering wavelength dependent concentration factor, absorption and focal length. The change in light concentration as a function of water volume was examined via the resulting load on the foil and the corresponding change of shape. The latter was extracted from images and modeled by a finite element simulation.

  1. Influence of process parameters on the photodegradation of synthesized azo pyridone dye in TiO2 water suspension under simulated sunlight.

    Science.gov (United States)

    Dostanić, Jasmina M; Loncarević, Davor R; Banković, Predrag T; Cvetković, Olga G; Jovanović, Dusan M; Mijin, Dusan Z

    2011-01-01

    Photocatalytic degradation of synthesized azo pyridone dye (5-(4-sulpho phenylazo)-6-hydroxy-4-methyl-3-cyano-2-pyridone), in aqueous solutions by simulated sunlight in the presence of commercial TiO(2), Aeroxide P25, was studied. The reaction kinetics analysis showed that photodegradation exhibits pseudo first-order kinetics according to Langmuir-Hinshelwood model. The effects of various process parameters on the photocatalytic degradation were investigated. The optimal catalyst content and pH were determined. A decrease in the reaction rate was observed upon the increase of the initial dye concentration. Degradation of the dye was enhanced by hydrogen peroxide, but it was inhibited by ethanol. The influence of temperature was studied, and the energy of activation was determined. According to total organic carbon (TOC) analysis, 54% of TOC remained when 100% of the dye was decolorized. Although the intermediates were not determined in this study, the TOC results clearly indicate their presence during the reaction. In addition, photocatalytic degradation of simulated dyehouse effluents, containing tested azo pyridone dye and associated auxiliary chemicals was investigated.

  2. Dietary intakes of expeditioners during prolonged sunlight deprivation in polar enviroments do not support bone health

    Directory of Open Access Journals (Sweden)

    Sandra Iuliano

    2015-08-01

    Full Text Available Background: Early Antarctic expeditions were plagued by nutrient deficiencies, due to lack of fresh food and reliance on preserved foods. Modern Antarctic expeditioners also require provisions to be shipped in, but improved knowledge and storage options ensure foods are nutritionally sound. Despite this, nutritional imbalances are observed. Objectives: To determine the adequacy of dietary intake of Antarctic expeditioners, with reference to bone health. Design: Dietary intake was determined on 225 adults (mean age 42±11 years, 16% female during 12-month deployments at Australian Antarctic stations from 2004 to 2010, using weighed 3-day food records. Nutrient intake was analysed using FoodWorks. Foods were divided into the 5 food groups according to the Australian Guide to Healthy Eating. Results: Men consumed below the recommended levels [recommended daily intake (RDI/adequate intakes (AI] of calcium (79±42% of RDI, p<0.001, magnesium (83±34% of RDI, p<0.001, potassium (86±29% of AI, p<0.001 and fibre (75±30% of AI, p<0.001, and above the upper limit (UL for sodium (125±48% of UL p<0.001, whereas women consumed below the recommended levels of calcium (68±21% of RDI, p<0.001 and iron (73±37% of RDI, p<0.001. Vitamin D intake is not substantial (<150 IU/d. Men consumed more alcohol than women (18±24 g/d vs. 10±13 g/d, p<0.05, nearer the guideline of ≤20 g/d. Men and women consumed approximately 1 serving of dairy food per day, and 3 of 5 recommended vegetable servings. Discretionary foods were consumed in excess of recommended. Conclusions: Improving consumption of calcium-rich (dairy foods better supports bone health during sunlight deprivation. Increasing vegetable intake to recommended levels will increase fibre, potassium and magnesium intakes. The challenge is the logistics of providing these foods throughout the year.

  3. Design and Analysis of an Optical Coupler for Concentrated Solar Light Using Optical Fibers in Residential Buildings

    Directory of Open Access Journals (Sweden)

    Afshin Aslian

    2016-01-01

    Full Text Available Concentrated sunlight that is transmitted by fiber optics has been used for generating electricity, heat, and daylight. On the other hand, multijunction photovoltaic cells provide high efficiency for generating electricity from highly concentrated sunlight. This study deals with designing and simulating a high-efficiency coupler, employing a mathematical model to connect sunlight with fiber optics for multiple applications. The coupler concentrates and distributes irradiated light from a primary concentrator. In this study, a parabolic dish was used as the primary concentrator, a coupler that contains nine components called a compound truncated pyramid and a cone (CTPC, all of which were mounted on a plate. The material of both the CTPC and the plate was BK7 optical glass. Fiber optics cables and multijunction photovoltaic cells were connected to the cylindrical part of the CTPC. The fibers would transmit the light to the building to provide heat and daylight, whereas multijunction photovoltaic cells generate electricity. Theoretical and simulation results showed high performance of the designed coupler. The efficiency of the coupler was as high as 92%, whereas the rim angle of the dish increased to an optimum angle. Distributed sunlight in the coupler increased the flexibility and simplicity of the design, resulting in a system that provided concentrated electricity, heat, and lighting for residential buildings.

  4. Design and construction of non-imaging planar concentrator for concentrator photovoltaic system

    Energy Technology Data Exchange (ETDEWEB)

    Chong, K.K.; Siaw, F.L.; Wong, C.W.; Wong, G.S. [Faculty of Engineering and Science, Universiti Tunku Abdul Rahman, Off Jalan Genting Kelang, Setapak, 53300 Kuala Lumpur, Wilayah Persekutuan (Malaysia)

    2009-05-15

    A novel configuration of solar concentrator, which is the non-imaging planar concentrator, capable of producing much more uniform sunlight and reasonably high concentration ratio, is designed and constructed. This design is envisioned to be incorporated in concentrator photovoltaic (CPV) systems. The work presented here reports on the design, optical alignment and application of the prototype, which is installed at Universiti Tunku Abdul Rahman (UTAR), Malaysia. In the architecture of the prototype, 360 flat mirrors, each with a dimension of 4.0 cm x 4.0 cm, are arranged into 24 rows and 15 columns with a total reflection area of about 5760 cm{sup 2}. In addition to that, illumination distribution for the prototype is simulated and its results are then compared with the experiment result. (author)

  5. Impact of Annual Temperature Variation on Distribution and Year-round Concentration Variation of Paulownia Witches' Broom Phytoplasma%周年温度变化对泡桐丛枝病植原体分布和消长的影响

    Institute of Scientific and Technical Information of China (English)

    曹亚兵; 翟晓巧; 介大委; 范国强

    2016-01-01

    To explore the effect of temperature variation on the distribution of witches' broom phytoplas-ma and its annual changes of relative content in paulownia,direct-RCR and nest-PCR were used to re-search the seasonal variation of the phytoplasma content and distribution. Our result showed that the distri-bution of phytoplasma in varying degree of diseased paulownia was different,meanwhile the concentration in different organs of the same plant was not the same. In the moderately diseased plant,phytoplasma sur-vived all the year round in branches and increased gradually with the rising of temperature. The highest concentration of phytoplasma appeared in August, and subsequently, the concentration of phytoplasma gradually decreased. The similar situation appeared in leaves,except that the concentration of phytoplasma reached the maximum in July and the minimum in October. In root, the phytoplasma concentration was lower and changed less than in leaves and branches,which reached the maximum in September,and then reduced. In all,the relationship between the variation of phytoplasma concentration in paulownia and an-nual changes of temperature was very close.%为探讨温度变化对泡桐树体内丛枝病植原体分布和消长的影响,利用巢式PCR和直接PCR研究了植原体在泡桐不同器官内的分布及相对含量的周年变化.结果表明,不同发病程度泡桐中丛枝病植原体的分布不同,发病程度相同泡桐不同器官内植原体含量也存在一定差异.在中等发病程度的泡桐中,丛枝病植原体全年存在于枝条内,并且其含量随温度升高逐渐升高,8月份达到最高,此后开始下降;叶片内植原体含量随温度升高明显增加,7月份含量最高,随后减少,10月份降到最低;根部植原体含量随温度升高也相应增加,在9月份达到最高,之后开始降低,全年含量变化较小,且含量最高值较叶片和枝条中低.表明泡桐丛枝病植原体在寄主体内的消长与

  6. LLNL NESHAPs 2002 Annual Report

    Energy Technology Data Exchange (ETDEWEB)

    Harrach, R J; Gallegos, G M; Peterson, S-R; Tate, P J; Bertoldo, N A; Wilson, K R; Althouse, P E; Larson, J M

    2003-06-01

    This annual report is prepared pursuant to the National Emission Standards for Hazardous Air Pollutants (NESHAPs; Title 40 Code of Federal Regulations [CFR] Part 61, Subpart H). Subpart H governs radionuclide emissions to air from Department of Energy (DOE) facilities. NESHAPs limits the emission of radionuclides to the ambient air from DOE facilities to levels resulting in an annual effective dose equivalent (EDE) of 10 mrem (100 {micro}Sv) to any member of the public. The EDEs for the Lawrence Livermore National Laboratory (LLNL) site-wide maximally exposed members of the public from operations in 2002 are summarized here: (1) Livermore site: 0.023 mrem (0.23 {micro}Sv) (43% from point-source emissions, 57% from diffuse-source emissions). The point-source emissions include gaseous tritium modeled as tritiated water vapor as directed by EPA Region IX; the resulting dose is used for compliance purposes; and (2) Site 300: 0.021 mrem (0.21 {micro}Sv) (85% from point-source emissions, 15% from diffuse-source emissions). The EDEs were calculated using the EPA-approved CAP88-PC air dispersion/dose-assessment model, except for doses for three diffuse sources, which were calculated from measured concentrations and dose coefficients. Site specific meteorological data, stack flow data, and emissions estimates based on radionuclide usage inventory data or continuous stack monitoring data were the specific inputs to CAP88-PC for each modeled source.

  7. LLNL NESHAPs 2003 Annual Report

    Energy Technology Data Exchange (ETDEWEB)

    Harrach, R J; Gallegos, G M; Peterson, S; Wilson, K R; Althouse, P E; Larson, J M; Bertoldo, N A; Tate, P J; Bowen, B

    2004-06-23

    This annual report is prepared pursuant to the National Emission Standards for Hazardous Air Pollutants (NESHAPs; Title 40 Code of Federal Regulations [CFR] Part 61, Subpart H). Subpart H governs radionuclide emissions to air from Department of Energy (DOE) facilities. NESHAPs limits the emission of radionuclides to the ambient air from DOE facilities to levels resulting in an annual effective dose equivalent (EDE) of 10 mrem (100 {micro}Sv) to any member of the public. The EDEs for the Lawrence Livermore National Laboratory (LLNL) site-wide maximally exposed members of the public from operations in 2003 are summarized here. Livermore site: 0.044 mrem (0.44 {micro}Sv) (55% from point-source emissions, 45% from diffuse-source emissions). The point-source emissions include gaseous tritium modeled as tritiated water vapor as directed by EPA Region IX; the resulting dose is used for compliance purposes. Site 300: 0.017 mrem (0.17 {micro}Sv) (98% from point-source emissions, 2% from diffuse-source emissions). The EDEs were calculated using the EPA-approved CAP88-PC air dispersion/dose-assessment model, except for doses for two diffuse sources that were estimated using measured concentrations and dose coefficients. Site specific meteorological data, stack flow data, and emissions estimates based on radionuclide usage inventory data or continuous stack monitoring data were the specific inputs to CAP88-PC for each modeled source.

  8. LLNL NESHAPs 2002 Annual Report

    Energy Technology Data Exchange (ETDEWEB)

    Harrach, R J; Gallegos, G M; Peterson, S-R; Tate, P J; Bertoldo, N A; Wilson, K R; Althouse, P E; Larson, J M

    2003-06-01

    This annual report is prepared pursuant to the National Emission Standards for Hazardous Air Pollutants (NESHAPs; Title 40 Code of Federal Regulations [CFR] Part 61, Subpart H). Subpart H governs radionuclide emissions to air from Department of Energy (DOE) facilities. NESHAPs limits the emission of radionuclides to the ambient air from DOE facilities to levels resulting in an annual effective dose equivalent (EDE) of 10 mrem (100 {micro}Sv) to any member of the public. The EDEs for the Lawrence Livermore National Laboratory (LLNL) site-wide maximally exposed members of the public from operations in 2002 are summarized here: (1) Livermore site: 0.023 mrem (0.23 {micro}Sv) (43% from point-source emissions, 57% from diffuse-source emissions). The point-source emissions include gaseous tritium modeled as tritiated water vapor as directed by EPA Region IX; the resulting dose is used for compliance purposes; and (2) Site 300: 0.021 mrem (0.21 {micro}Sv) (85% from point-source emissions, 15% from diffuse-source emissions). The EDEs were calculated using the EPA-approved CAP88-PC air dispersion/dose-assessment model, except for doses for three diffuse sources, which were calculated from measured concentrations and dose coefficients. Site specific meteorological data, stack flow data, and emissions estimates based on radionuclide usage inventory data or continuous stack monitoring data were the specific inputs to CAP88-PC for each modeled source.

  9. LLNL NESHAPs 2003 Annual Report

    Energy Technology Data Exchange (ETDEWEB)

    Harrach, R J; Gallegos, G M; Peterson, S; Wilson, K R; Althouse, P E; Larson, J M; Bertoldo, N A; Tate, P J; Bowen, B

    2004-06-23

    This annual report is prepared pursuant to the National Emission Standards for Hazardous Air Pollutants (NESHAPs; Title 40 Code of Federal Regulations [CFR] Part 61, Subpart H). Subpart H governs radionuclide emissions to air from Department of Energy (DOE) facilities. NESHAPs limits the emission of radionuclides to the ambient air from DOE facilities to levels resulting in an annual effective dose equivalent (EDE) of 10 mrem (100 {micro}Sv) to any member of the public. The EDEs for the Lawrence Livermore National Laboratory (LLNL) site-wide maximally exposed members of the public from operations in 2003 are summarized here. Livermore site: 0.044 mrem (0.44 {micro}Sv) (55% from point-source emissions, 45% from diffuse-source emissions). The point-source emissions include gaseous tritium modeled as tritiated water vapor as directed by EPA Region IX; the resulting dose is used for compliance purposes. Site 300: 0.017 mrem (0.17 {micro}Sv) (98% from point-source emissions, 2% from diffuse-source emissions). The EDEs were calculated using the EPA-approved CAP88-PC air dispersion/dose-assessment model, except for doses for two diffuse sources that were estimated using measured concentrations and dose coefficients. Site specific meteorological data, stack flow data, and emissions estimates based on radionuclide usage inventory data or continuous stack monitoring data were the specific inputs to CAP88-PC for each modeled source.

  10. International energy annual 1996

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-02-01

    The International Energy Annual presents an overview of key international energy trends for production, consumption, imports, and exports of primary energy commodities in over 220 countries, dependencies, and areas of special sovereignty. Also included are population and gross domestic product data, as well as prices for crude oil and petroleum products in selected countries. Renewable energy reported in the International Energy Annual includes hydroelectric power, geothermal, solar, and wind electric power, biofuels energy for the US, and biofuels electric power for Brazil. New in the 1996 edition are estimates of carbon dioxide emissions from the consumption of petroleum and coal, and the consumption and flaring of natural gas. 72 tabs.

  11. Natural gas annual 1997

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-10-01

    The Natural Gas Annual provides information on the supply and disposition of natural gas to a wide audience including industry, consumers, Federal and State agencies, and educational institutions. The 1997 data are presented in a sequence that follows natural gas (including supplemental supplies) from its production to its end use. This is followed by tables summarizing natural gas supply and disposition from 1993 to 1997 for each Census Division and each State. Annual historical data are shown at the national level. 27 figs., 109 tabs.

  12. Sunlight associated hyperthermia as a consistent and rapidly developing clinical sign in sheep intoxicated by St John's wort (Hypericum perforatum).

    Science.gov (United States)

    Bourke, C A

    2000-07-01

    To assess the usefulness of rectal temperature responses in Australian bred Merino sheep, following the oral administration of Hypericum perforatum (St John's wort), as an early indicator of Hypericum intolerance. Thirty-three Merino ewes were divided into three groups of 11. Each group was dosed with finely ground, dried, flowering growth stage H perforatum plant material at either 5.7, 4.0, or 2.85 g dry plant per kg live weight. This corresponded to 5.3, 3.7 and 2.65 mg hypericin per kg live weight, respectively. The sheep were dosed with a plant slurry by stomach tube and then exposed to bright sunlight for up to 5 h per day over successive days. Their clinical responses were observed and rectal temperature measured. Ingestion of H perforatum followed by exposure to bright sunlight frequently resulted in clinical signs attributable to skin irritation and central nervous effects, including an inappropriate increase in body temperature. A decrease in H perforatum ingestion from 5.7 to 2.85 g dry plant per kg live weight and a corresponding decrease in hypericin ingestion from 5.3 to 2.65 mg per kg live weight, was associated with a decrease in the severity of the clinical signs, including the severity of the hyperthermia. The rectal temperature rise in affected sheep is a reliable indicator of the early development of an adverse clinical effect. There appears to be an absolute requirement for exposure to bright sunlight before any effects of H perforatum will develop. A single dose of H perforatum remains potentially effective for up to 4 days. In the small group of Merino sheep tested a tolerance level for H perforatum, eaten at the flowering stage, of plant wet weight) of body weight and a tolerance level for hypericin of < 2.65 mg per kg live weight, were demonstrated.

  13. TiO2-NiO p-n nanocomposite with enhanced sonophotocatalytic activity under diffused sunlight.

    Science.gov (United States)

    Vinoth, R; Karthik, P; Devan, K; Neppolian, B; Ashokkumar, Muthupandian

    2017-03-01

    TiO2-NiO composites with p-n junction were developed by assembling p-type NiO on n-type TiO2 using ultrasound assisted wet impregnation method. The sonophotocatalytic efficiencies of pure TiO2 and TiO2-NiO composites were evaluated under diffused sunlight using methyl orange (MO) as a model pollutant. The impregnation of NiO nanoparticles on TiO2 considerably enhanced the optical absorption in visible region (500-800nm) due to the formation of p-n junctions at the interface between TiO2 and NiO. The internal electric field induced by the p-n junction led to effective separation of electron-hole pairs and thereby generating a large amount of reactive species for the degradation of MO. The individual effect of ultrasound and diffused sunlight for the degradation of MO was found to be 30% and 6%, respectively. A synergy of 4.8 fold was achieved when ultrasound was combined with photocatalytic degradation process in the presence of diffused sunlight. The sonophotocatalytic activity of TiO2-NiO photocatalysts with different NiO loading was also evaluated and 10wt% NiO loading was found to be optimal. Moreover, 66% of Total Organic Carbon (TOC) removal was achieved with the optimized TiO2-NiO composite in 140min. In addition, the TiO2-NiO composite exhibited an enhanced photocurrent response under visible light illumination.

  14. Sunlight and the 5-year incidence of early age-related maculopathy: the beaver dam eye study.

    Science.gov (United States)

    Cruickshanks, K J; Klein, R; Klein, B E; Nondahl, D M

    2001-02-01

    To investigate the relation of sunlight exposure and indicators of sun sensitivity with the 5-year incidence of early age-related maculopathy (ARM). Longitudinal, population-based study. Participants (aged 43-86 years at baseline) in the Beaver Dam Eye Study were reexamined from 1993 to 1995, 5 years after the baseline examination. Questionnaire data about sunlight exposure and sun sensitivity were obtained at baseline. Additional information about earlier life patterns of exposure was ascertained at follow-up. Stereoscopic color fundus photographs were graded to determine the presence of ARM at the 5-year follow-up in eyes free from signs of early ARM at the baseline examination. Leisure time spent outdoors while persons were teenagers (aged 13-19 years) and in their 30s (aged 30-39 years) was significantly associated with the risk of early ARM (odds ratio, 2.09; 95% confidence interval, 1.19-3.65). There was a slight, but nonsignificant, protective effect associated with use of hats and sunglasses while persons were teenagers and in their 30s (odds ratio, 0.72; 95% confidence interval, 0.50-1.03). People with red or blond hair were slightly more likely to develop early ARM than people with darker hair (odds ratio, 1.33; 95% confidence interval, 0.97-1.83). There were no associations between estimated ambient UV-B exposure or markers of sun sensitivity and the incidence of early ARM. Exposure to sunlight may be associated with the development of early ARM.

  15. Using Microporous Polytetrafluoroethylene Thin Sheets as a Flexible Solar Diffuser to Minimize Sunlight Glint to Cameras in Space

    Science.gov (United States)

    Choi, Michael K.

    2016-01-01

    An innovative design of using microporous PTFE thin sheets as a solar diffuser for MLI blankets or mechanical structure has been developed. It minimizes sunlight or stray-light glint to cameras when it is incident on these components in space. A microporous black PTFE thin sheet solar diffuser has been qualified for flight at NASA GSFC and installed to the TAGSAM arm MLI, OCAMS PolyCam sunshade MLI and SamCam motor riser MLI in the NASA OSIRIS-REx mission to meet the SamCam camera BRDF requirement.

  16. Porous graphitic carbon nitride synthesized via direct polymerization of urea for efficient sunlight-driven photocatalytic hydrogen production

    Science.gov (United States)

    Zhang, Yuewei; Liu, Jinghai; Wu, Guan; Chen, Wei

    2012-08-01

    Energy captured directly from sunlight provides an attractive approach towards fulfilling the need for green energy resources on the terawatt scale with minimal environmental impact. Collecting and storing solar energy into fuel through photocatalyzed water splitting to generate hydrogen in a cost-effective way is desirable. To achieve this goal, low cost and environmentally benign urea was used to synthesize the metal-free photocatalyst graphitic carbon nitride (g-C3N4). A porous structure is achieved via one-step polymerization of the single precursor. The porous structure with increased BET surface area and pore volume shows a much higher hydrogen production rate under simulated sunlight irradiation than thiourea-derived and dicyanamide-derived g-C3N4. The presence of an oxygen atom is presumed to play a key role in adjusting the textural properties. Further improvement of the photocatalytic function can be expected with after-treatment due to its rich chemistry in functionalization.Energy captured directly from sunlight provides an attractive approach towards fulfilling the need for green energy resources on the terawatt scale with minimal environmental impact. Collecting and storing solar energy into fuel through photocatalyzed water splitting to generate hydrogen in a cost-effective way is desirable. To achieve this goal, low cost and environmentally benign urea was used to synthesize the metal-free photocatalyst graphitic carbon nitride (g-C3N4). A porous structure is achieved via one-step polymerization of the single precursor. The porous structure with increased BET surface area and pore volume shows a much higher hydrogen production rate under simulated sunlight irradiation than thiourea-derived and dicyanamide-derived g-C3N4. The presence of an oxygen atom is presumed to play a key role in adjusting the textural properties. Further improvement of the photocatalytic function can be expected with after-treatment due to its rich chemistry in

  17. NERSC Annual Report 2005

    Energy Technology Data Exchange (ETDEWEB)

    Hules (Ed.), John

    2006-07-31

    The National Energy Research Scientific Computing Center (NERSC) is the premier computational resource for scientific research funded by the DOE Office of Science. The Annual Report includes summaries of recent significant and representative computational science projects conducted on NERSC systems as well as information about NERSC's current and planned systems and services.

  18. NERSC Annual Report 2002

    Energy Technology Data Exchange (ETDEWEB)

    Hules, John

    2003-01-31

    The National Energy Research Scientific Computing Center (NERSC) is the primary computational resource for scientific research funded by the DOE Office of Science. The Annual Report for FY2002 includes a summary of recent computational science conducted on NERSC systems (with abstracts of significant and representative projects), and information about NERSC's current and planned systems and service

  19. NRCC annual report, 1979

    Energy Technology Data Exchange (ETDEWEB)

    1980-11-01

    This annual report of the National Research for Computation in Chemistry (NRCC) Division describes the program of research workshops, software development, and scientific research of the Division in 1979. This year marked the first full calendar year of activity of the Division. Initial staffing in the core scientific areas was completed by the addition of a crystallographer.

  20. CSIR Annual report 1966

    CSIR Research Space (South Africa)

    CSIR

    1966-01-01

    Full Text Available This report presents the twenty second annual report of the Council for Scientific and Industrial Research. The report covers the period from the 1st January, 1966, to the 31st December 1966. Balance sheets and statements of income and expenditure...

  1. CSIR Annual report 1970

    CSIR Research Space (South Africa)

    CSIR

    1970-01-01

    Full Text Available This report presents the twenty sixth annual report of the Council for Scientific and Industrial Research. The report covers the period from the 1st January, 1970, to the 31st December 1970. Balance sheets and statements of income and expenditure...

  2. Mail Office annual closure

    CERN Multimedia

    2013-01-01

    On the occasion of the annual closure of CERN, there will be no mail distributed on Friday 20 December 2013 but mail will be collected in the morning. Nevertheless, you will still be able to bring your outgoing mail to Building 555-R-002 until 12 noon.  

  3. Annual Report 2000

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-07-01

    The Institut Laue-Langevin (ILL) is an international research center using neutrons to probe the microscopic structure and dynamics of a broad range of materials. This annual report presents the ILL activities in 2000: the scientific highlights, the Millennium programme and the new developments, the workshops organized by the ILL, the experimental programme and the publications. (A.L.B.)

  4. 2010 AAUW Annual Report

    Science.gov (United States)

    American Association of University Women, 2010

    2010-01-01

    This report highlights some of the outstanding accomplishments of AAUW (American Association of University Women) for fiscal year 2010. This year's annual report also features stories of remarkable women who are leading the charge to break through barriers and ensure that all women have a fair chance. Sharon is working to reduce the pay gap…

  5. Annual report 1995

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-09-01

    SaskPower`s mission is to meet the electrical needs of Saskatchewan residents in a reliable, safe, efficient and environmentally responsible manner. This annual report of the Corporation discusses new business focus; operations highlights; quality of life; management discussion and analysis; financial ratios; and a report of management. Financial information is also included.

  6. Annual report 1995

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-10-01

    The annual report from IKU (Continental Shelf Institute) in Norway deals with the market adjustment of research activities at the institute as a result of offshore cost-cutting policy in the petroleum industry. The market is about to shift focus from volume to competence. In practice, that means buying competence instead of project ideas or proposals

  7. NERSC Annual Report 2004

    Energy Technology Data Exchange (ETDEWEB)

    Hules, John; Bashor, Jon; Yarris, Lynn; McCullough, Julie; Preuss, Paul; Bethel, Wes

    2005-04-15

    The National Energy Research Scientific Computing Center (NERSC) is the premier computational resource for scientific research funded by the DOE Office of Science. The Annual Report includes summaries of recent significant and representative computational science projects conducted on NERSC systems as well as information about NERSC's current and planned systems and services.

  8. CSIR Annual report 1968

    CSIR Research Space (South Africa)

    CSIR

    1968-01-01

    Full Text Available This report presents the twenty fourth annual report of the Council for Scientific and Industrial Research. The report covers the period from the 1st January, 1968, to the 31st December 1968. Balance sheets and statements of income and expenditure...

  9. CSIR Annual report 1971

    CSIR Research Space (South Africa)

    CSIR

    1971-01-01

    Full Text Available This report presents the twenty seventh annual report of the Council for Scientific and Industrial Research. The report covers the period from the 1st January, 1971, to the 31st December 1971. Balance sheets and statements of income and expenditure...

  10. CSIR Annual report 1969

    CSIR Research Space (South Africa)

    CSIR

    1969-01-01

    Full Text Available This report presents the twenty fifth annual report of the Council for Scientific and Industrial Research. The report covers the period from the 1st January, 1969, to the 31st December 1969. Balance sheets and statements of income and expenditure...

  11. Annual HR Salary Survey.

    Science.gov (United States)

    Schaeffer, Patricia

    2000-01-01

    A trainers' salary survey collected data on 1,091 companies, 31,615 employees, and 97 human resource jobs. Results show pay for human resource professionals is continuing to rise. The survey contains information on base salaries, annual bonuses and incentives, and long-term eligibility incentives. (JOW)

  12. Carolinas Communication Annual, 1998.

    Science.gov (United States)

    McLennan, David B.

    1998-01-01

    This 1998 issue of "Carolinas Communication Annual" contains the following articles: "Give Me That Old Time Religion?: A Study of Religious Themes in the Rhetoric of the Ku Klux Klan" (John S. Seiter); "The Three Stooges versus the Third Reich" (Roy Schwartzman); "Interdisciplinary Team Teaching: Implementing…

  13. International Energy Annual, 1992

    Energy Technology Data Exchange (ETDEWEB)

    1994-01-14

    This report is prepared annually and presents the latest information and trends on world energy production and consumption for petroleum, natural gas, coal, and electricity. Trade and reserves are shown for petroleum, natural gas, and coal. Prices are included for selected petroleum products. Production and consumption data are reported in standard units as well as British thermal units (Btu) and joules.

  14. UNICEF Annual Report. 1984.

    Science.gov (United States)

    United Nations Children's Fund, New York, NY.

    This annual report reviews the work UNICEF has been doing to help transform the "Child Survival Revolution" from a dream into a reality. Discussion focuses primarily on child health and nutrition and other basic services for children. Throughout, the review is supplemented with profiles of program initiatives made to improve the…

  15. CSIR Annual report 1963

    CSIR Research Space (South Africa)

    CSIR

    1963-01-01

    Full Text Available This report presents the nineteenth annual report of the Council for Scientific and Industrial Research. The report covers the period from the 1st January, 1963, to the 31st December 1963. Balance sheets and statements of income and expenditure...

  16. CSIR Annual report 1982

    CSIR Research Space (South Africa)

    CSIR

    1982-01-01

    Full Text Available This report presents the thirty eighth annual report of the CSIR. The report covers the period 1 January, 1982 to 31 December 1982. A balance sheet and statements of income and expenditure for the financial year ended 31st March 1982, certified...

  17. CSIR Annual report 1980

    CSIR Research Space (South Africa)

    CSIR

    1980-01-01

    Full Text Available This report presents the thirty-sixth annual report of the CSIR. The report covers the period 1 January, 1980 to 31 December 1980. A balance sheet and statements of income and expenditure for the financial year ended 31st March 1980, certified...

  18. Sunlight and the 10-year incidence of age-related maculopathy: the Beaver Dam Eye Study.

    Science.gov (United States)

    Tomany, Sandra C; Cruickshanks, Karen J; Klein, Ronald; Klein, Barbara E K; Knudtson, Michael D

    2004-05-01

    To examine the association of sunlight exposure and indicators of sun sensitivity with the 10-year incidence of age-related maculopathy (ARM). Population-based cohort study. We included persons aged 43 to 86 years at the baseline examination from 1988 to 1990, living in Beaver Dam, Wis, of whom 3684 persons underwent 5-year follow-up and 2764 underwent 10-year follow-up. Data on sun exposure and indicators of sun sensitivity were obtained from a standardized questionnaire administered at baseline and/or follow-up. We determined ARM status by grading stereoscopic color fundus photographs using the Wisconsin Age-Related Maculopathy Grading System. Incidence and progression of ARM. While controlling for age and sex, we found that participants exposed to the summer sun for more than 5 hours a day during their teens, in their 30s, and at the baseline examination were at a higher risk of developing increased retinal pigment (risk ratio [RR], 2.99; 95% confidence interval [CI], 1.18-7.60; P =.02) and early ARM (RR, 2.20; 95% CI, 1.02-4.73; P =.04) [corrected] by 10 years than those exposed less than 2 hours per day during the same periods. In participants reporting the highest summer sun exposure levels in their teens and 30s, the use of hats and sunglasses at least half the time during the same periods was associated with a decreased risk of developing soft indistinct drusen (RR, 0.55; 95% CI, 0.33-0.90; P =.02) and retinal pigment epithelial depigmentation (RR, 0.51; 95% CI, 0.29-0.91; P =.02). Participants who experienced more than 10 severe sunburns during their youth were more likely than those who experienced 1 or no burn to develop drusen with a 250-microm diameter or larger (RR, 2.52; 95% CI, 1.29-4.94 [corrected] P =.01) by the 10-year examination. No relationships were found between UV-B exposure, winter leisure time spent outdoors, skin sun sensitivity, or number of bad sunburns experienced by the time of the baseline examination and the 10-year incidence and

  19. Patterns and timing of sunlight exposure and risk of basal cell and squamous cell carcinomas of the skin – a case–control study

    Directory of Open Access Journals (Sweden)

    Iannacone Michelle R

    2012-09-01

    Full Text Available Abstract Background Non-melanoma skin cancer (NMSC, comprised of basal (BCC and squamous (SCC cell carcinomas, is the most common cancer in Caucasians. Ultraviolet radiation (UVR exposure is the most important environmental risk factor for NMSC. However, the precise relationship between UVR and the risk of NMSC is complex, and the relationship may differ by skin cancer type. Methods A case–control study was conducted among Florida residents to investigate measures of patterns (intermittent vs. continuous and timing (childhood vs. adulthood of sunlight exposure in BCC and SCC. Participants included 218 BCC and 169 SCC cases recruited from a university dermatology clinic and 316 controls with no history of skin or other cancers. Results A history of blistering sunburn (a measure of intermittent sunlight exposure was associated with both BCC (OR = 1.96, 95% CI = 1.27-3.03 and SCC (OR = 2.02, 95% CI = 1.22-3.33. Additionally, having a job in the sun for ≥3 months for 10 years or longer (a measure of continuous sunlight exposure was also associated with both BCC and SCC in our study population. With the exception of younger age at first blistering sunburn, measures of younger age at sunlight exposure tended to be associated with SCC, but not BCC risk. Conclusions Results from the current study suggest that sunlight exposure is associated with both BCC and SCC risk regardless of the pattern in which the exposure was received (i.e. intermittent vs. continuous. The data also suggest that sunlight exposure at a younger age may be more important for SCC but not BCC, however additional studies are needed to further characterize sunlight exposure-response relationships in different types of NMSC.

  20. Patterns and timing of sunlight exposure and risk of basal cell and squamous cell carcinomas of the skin--a case-control study.

    Science.gov (United States)

    Iannacone, Michelle R; Wang, Wei; Stockwell, Heather G; O'Rourke, Kathleen; Giuliano, Anna R; Sondak, Vernon K; Messina, Jane L; Roetzheim, Richard G; Cherpelis, Basil S; Fenske, Neil A; Rollison, Dana E

    2012-09-20

    Non-melanoma skin cancer (NMSC), comprised of basal (BCC) and squamous (SCC) cell carcinomas, is the most common cancer in Caucasians. Ultraviolet radiation (UVR) exposure is the most important environmental risk factor for NMSC. However, the precise relationship between UVR and the risk of NMSC is complex, and the relationship may differ by skin cancer type. A case-control study was conducted among Florida residents to investigate measures of patterns (intermittent vs. continuous) and timing (childhood vs. adulthood) of sunlight exposure in BCC and SCC. Participants included 218 BCC and 169 SCC cases recruited from a university dermatology clinic and 316 controls with no history of skin or other cancers. A history of blistering sunburn (a measure of intermittent sunlight exposure) was associated with both BCC (OR = 1.96, 95% CI = 1.27-3.03) and SCC (OR = 2.02, 95% CI = 1.22-3.33). Additionally, having a job in the sun for ≥ 3 months for 10 years or longer (a measure of continuous sunlight exposure) was also associated with both BCC and SCC in our study population. With the exception of younger age at first blistering sunburn, measures of younger age at sunlight exposure tended to be associated with SCC, but not BCC risk. Results from the current study suggest that sunlight exposure is associated with both BCC and SCC risk regardless of the pattern in which the exposure was received (i.e. intermittent vs. continuous). The data also suggest that sunlight exposure at a younger age may be more important for SCC but not BCC, however additional studies are needed to further characterize sunlight exposure-response relationships in different types of NMSC.

  1. Patterns and timing of sunlight exposure and risk of basal cell and squamous cell carcinomas of the skin – a case–control study

    Science.gov (United States)

    2012-01-01

    Background Non-melanoma skin cancer (NMSC), comprised of basal (BCC) and squamous (SCC) cell carcinomas, is the most common cancer in Caucasians. Ultraviolet radiation (UVR) exposure is the most important environmental risk factor for NMSC. However, the precise relationship between UVR and the risk of NMSC is complex, and the relationship may differ by skin cancer type. Methods A case–control study was conducted among Florida residents to investigate measures of patterns (intermittent vs. continuous) and timing (childhood vs. adulthood) of sunlight exposure in BCC and SCC. Participants included 218 BCC and 169 SCC cases recruited from a university dermatology clinic and 316 controls with no history of skin or other cancers. Results A history of blistering sunburn (a measure of intermittent sunlight exposure) was associated with both BCC (OR = 1.96, 95% CI = 1.27-3.03) and SCC (OR = 2.02, 95% CI = 1.22-3.33). Additionally, having a job in the sun for ≥3 months for 10 years or longer (a measure of continuous sunlight exposure) was also associated with both BCC and SCC in our study population. With the exception of younger age at first blistering sunburn, measures of younger age at sunlight exposure tended to be associated with SCC, but not BCC risk. Conclusions Results from the current study suggest that sunlight exposure is associated with both BCC and SCC risk regardless of the pattern in which the exposure was received (i.e. intermittent vs. continuous). The data also suggest that sunlight exposure at a younger age may be more important for SCC but not BCC, however additional studies are needed to further characterize sunlight exposure-response relationships in different types of NMSC. PMID:22994655

  2. Knowledge of vitamin D and perceptions and attitudes toward sunlight among Chinese middle-aged and elderly women: a population survey in Hong Kong

    Directory of Open Access Journals (Sweden)

    Lee Ka-Kui

    2006-09-01

    Full Text Available Abstract Background Physical and biological risk factors for vitamin D inadequacy are known; however, cultural- and population-specific behaviours and attitudes that influence these risk factors, particularly among Asian people, are less well documented. To understand more about prevailing attitudes and behaviour toward sunlight and knowledge of vitamin D among a population at greater risk of impaired vitamin D status, poor bone health and osteoporosis, we conducted a telephone interview survey of 547 middle-aged and elderly Chinese women living in Hong Kong. Methods All telephone interviews were conducted using the Computer Assisted Telephone Technique and target respondents were selected by random sampling. Interviews were conducted in Cantonese and eighteen main questions were asked pertaining to personal characteristics, perceptions, attitudes and behaviour toward sunlight, and knowledge about vitamin D. Results The survey results showed that 62.3% (n = 341 did not like going in the sun and 66.7% of respondents spent an average of 6–10 hours indoors, between 6:30 am and 7:00 pm, during weekdays. However, 58% of people thought that they had enough exposure to sunlight. The majority had heard of vitamin D, but knowledge about the role and sources of vitamin D was low. Among those who knew that sunlight was a source of vitamin D, the majority spent less than 1 h in the sun in the past week (76.4% vs 23.6%, 1 h in the sun in the past week, chi-square p Conclusion The survey revealed considerable ignorance and confusion about the role of sunlight in vitamin D production, and the function and sources of vitamin D. Attitudes and behaviour toward sunlight were largely negative and many took measures to avoid sunlight, particularly among younger (middle-aged women who had good awareness of vitamin D.

  3. Anatomical exposure patterns of skin to sunlight: relative contributions of direct, diffuse and reflected ultraviolet radiation.

    Science.gov (United States)

    Vernez, D; Milon, A; Vuilleumier, L; Bulliard, J-L

    2012-08-01

    The dose-response between ultraviolet (UV) exposure patterns and skin cancer occurrence is not fully understood. Sun-protection messages often focus on acute exposure, implicitly assuming that direct UV radiation is the key contributor to the overall UV exposure. However, little is known about the relative contribution of the direct, diffuse and reflected radiation components. To investigate solar UV exposure patterns at different body sites with respect to the relative contribution of the direct, diffuse and reflected radiation. A three-dimensional numerical model was used to assess exposure doses for various body parts and exposure scenarios of a standing individual (static and dynamic postures). The model was fed with erythemally weighted ground irradiance data for the year 2009 in Payerne, Switzerland. A year-round daily exposure (08:00-17:00 h) without protection was assumed. For most anatomical sites, mean daily doses were high (typically 6.2-14.6 standard erythemal doses) and exceeded the recommended exposure values. Direct exposure was important during specific periods (e.g. midday during summer), but contributed moderately to the annual dose, ranging from 15% to 24% for vertical and horizontal body parts, respectively. Diffuse irradiation explained about 80% of the cumulative annual exposure dose. Acute diffuse exposures were also observed during cloudy summer days. The importance of diffuse UV radiation should not be underestimated when advocating preventive measures. Messages focused on avoiding acute direct exposures may be of limited efficiency to prevent skin cancers associated with chronic exposure. © 2012 The Authors. BJD © 2012 British Association of Dermatologists.

  4. Concentrating Radioactivity

    Science.gov (United States)

    Herrmann, Richard A.

    1974-01-01

    By concentrating radioactivity contained on luminous dials, a teacher can make a high reading source for classroom experiments on radiation. The preparation of the source and its uses are described. (DT)

  5. Sunlight, Sea Ice, and the Ice Albedo Feedback in a Changing Arctic Sea Ice Cover

    Science.gov (United States)

    2013-09-30

    ice age, and iv) onset dates of melt and freezeup . 4. Assess the magnitude of the contribution from ice-albedo feedback to the observed decrease of...the impact on albedo evolution of ice concentration and melt and freezeup onset dates. This effort will expand on previous work by i) examining...radiation, ice concentration, ice type, and melt and freezeup onset dates on a 25 x 25 km equal area scalable grid. We have daily values of these parameters

  6. Photosensitized mefloquine induces ROS-mediated DNA damage and apoptosis in keratinocytes under ambient UVB and sunlight exposure.

    Science.gov (United States)

    Yadav, Neera; Dwivedi, Ashish; Mujtaba, Syed Faiz; Verma, Ankit; Chaturvedi, Rajnish; Ray, Ratan Singh; Singh, Gajendra

    2014-10-01

    The present study illustrates the photosensitizing behavior of mefloquine (MQ) in human skin keratinocytes under ambient doses of UVB and sunlight exposure. Photochemically, MQ generated reactive oxygen species superoxide radical, hydroxyl radical, and singlet oxygen through type I and type II photodynamic reactions, respectively, which caused photooxidative damage to DNA and formed localized DNA lesions cyclobutane pyrimidine dimers. Photosensitized MQ reduced the viability of keratinocytes to 25 %. Significant level of intracellular reactive oxygen species (ROS) generation was estimated through fluorescence probe DCF-H2. Increased apoptotic cells were evident through AO/EB staining and phosphatidyl serine translocation in cell membrane. Single-stranded DNA damage was marked through single-cell gel electrophoresis. Mitochondrial membrane depolarization and lysosomal destabilization were evident. Upregulation of Bax and p21 and downregulation of Bcl-2 genes and corresponding protein levels supported apoptotic cell death of keratinocyte cells. Cyclobutane pyrimidine dimers (CPDs) were confirmed through immunofluorescence. In addition, hallmarks of apoptosis and G2/M phase cell cycle arrest were confirmed through flow cytometry analysis. Our findings suggest that MQ may damage DNA and produce DNA lesions which may induce differential biological responses in the skin on brief exposure to UVB and sunlight.

  7. Interactions of ozone with organic surface films in the presence of simulated sunlight: impact on wettability of aerosols.

    Science.gov (United States)

    Nieto-Gligorovski, L; Net, S; Gligorovski, S; Zetzsch, C; Jammoul, A; D'Anna, B; George, C

    2008-05-28

    Heterogeneous reactions between organic films, taken as proxies for atmospheric aerosols, with ozone in presence of simulated sunlight and the photosensitizer 4-carboxybenzophenone (4-CB) were observed to alter surface properties as monitored by contact angle during the reaction. Attenuated total reflectance Fourier transform infrared spectroscopy (FTIR-ATR) was used in addition for product identification. Two types of model surfaces were systematically studied: 4-CB/4-phenoxyphenol and 4-CB/catechol. Solid organic films made of 4-CB/catechol were observed to become hydrophilic by simultaneous exposure to ozone and simulated sunlight, whereas organic films made of 4-CB/4-phenoxyphenol become hydrophobic under the same conditions. These changes in contact angle indicate that photo-induced aging processes involving ozone (such as oligomerisation) not necessarily favour increased hygroscopicity of organic aerosols in the atmosphere. The ratio between hydrophobic and hydrophilic functional groups should reflect the chemical property of organic films with respect to wettability phenomena. Contact angles and surface tensions of the exposed organic film made of 4-CB/4-phenoxyphenol were found to correspond to the hydrophobic/hydrophilic ratios obtained from the FTIR-ATR spectra.

  8. Sunlight Triggers Cutaneous Lupus through a Colony Stimulating Factor-1 (CSF-1) Dependent Mechanism in MRL-Faslpr mice

    Science.gov (United States)

    Menke, Julia; Hsu, Mei-Yu; Byrne, Katelyn T.; Lucas, Julie A.; Rabacal, Whitney A.; Croker, Byron P.; Zong, Xiao-Hua; Stanley, E. Richard; Kelley, Vicki R.

    2008-01-01

    Sunlight (UVB) triggers cutaneous (CLE) and systemic lupus through an unknown mechanism. We tested the hypothesis that UVB triggers CLE through a CSF-1-dependent, macrophage (Mø) -mediated mechanism in MRL-Faslpr mice. By constructing mutant MRL-Faslpr strains expressing varying levels of CSF-1 (high, intermediate, none), and use of an ex-vivo gene transfer to deliver CSF-1 intra-dermally, we determined that CSF-1 induces CLE in lupus-susceptible, MRL-Faslpr mice, but not in lupus-resistant, BALB/c mice. Notably, UVB incites an increase in Mø, apoptosis in the skin and CLE in MRL-Faslpr, but not in CSF-1-deficient MRL-Faslpr mice. Furthermore, UVB did not induce CLE in BALB/c mice. Probing further, UVB stimulates CSF-1 expression by keratinocytes leading to recruitment and activation of Mø that, in turn, release mediators, which induce apoptosis in keratinocytes. Thus, sunlight triggers a CSF-1-dependent, Mø-mediated destructive inflammation in the skin leading to CLE in lupus-susceptible MRL-Faslpr, but not lupus-resistant BALB/c mice. Taken together, we envision CSF-1 as the “match” and lupus-susceptibility as the “tinder” leading to CLE. PMID:18981160

  9. Enhanced photocatalytic activity of TiO2 under sunlight by MoS2 nanodots modification

    Science.gov (United States)

    Wang, Ding; Xu, Ying; Sun, Feng; Zhang, Quanhua; Wang, Ping; Wang, Xianying

    2016-07-01

    In this study, MoS2 nanodots modified TiO2 (P25) composite photocatalyst (MoS2/P25) was fabricated via a facile liquid ultrasonic mixing method. Compared to the pure P25, the MoS2/P25 exhibited improved photocatalytic degradation activity under simulated sunlight with rhodamine B (RhB) and methylene blue (MB) as the target pollutants. RhB or MB (40 mL 10 mg/L) completely degraded within 20 min, and the kinetic constant reached 0.221 and 0.253 min-1 for RhB and MB, respectively. Based on the characterization of transient photocurrent response measurement and UV-vis diffuse reflectance spectra, a possible photocatalytic mechanism was proposed. The enhanced photocatalytic performance was attributed to the heterostructure of P25 and MoS2 nanodots, improving their charge separation and enhancing their absorption capacity to the full sunlight spectrum. We believe that this study will contribute to the development of new photocatalysts and improving the catalytic performance of traditional photocatalysts.

  10. Polydopamine-Coated Porous Substrates as a Platform for Mineralized β-FeOOH Nanorods with Photocatalysis under Sunlight.

    Science.gov (United States)

    Zhang, Chao; Yang, Hao-Cheng; Wan, Ling-Shu; Liang, Hong-Qing; Li, Hanying; Xu, Zhi-Kang

    2015-06-03

    Immobilization of photo-Fenton catalysts on porous materials is crucial to the efficiency and stability for water purification. Here we report polydopamine (PDA)-coated porous substrates as a platform for in situ mineralizing β-FeOOH nanorods with enhanced photocatalytic performance under sunlight. The PDA coating plays multiple roles as an adhesive interface, a medium inducing mineral generation, and an electron transfer layer. The mineralized β-FeOOH nanorods perfectly wrap various porous substrates and are stable on the substrates that have a PDA coating. The immobilized β-FeOOH nanorods have been shown to be efficient for degrading dyes in water via a photo-Fenton reaction. The degradation efficiency reaches approximately 100% in 60 min when the reaction was carried out with H2O2 under visible light, and it remains higher than 90% after five cycles. We demonstrate that the PDA coating promotes electron transfer to reduce the electron-hole recombination rate. As a result, the β-FeOOH nanorods wrapped on the PDA-coated substrates show enhanced photocatalytic performance under direct sunlight in the presence of H2O2. Moreover, this versatile platform using porous materials as the substrate is useful in fabricating β-FeOOH nanorods-based membrane reactor for wastewater treatment.

  11. Sunlight-Sensitive Anti-Fouling Nanostructured TiO2 coated Cu Meshes for Ultrafast Oily Water Treatment

    Science.gov (United States)

    Liu, Haoran; Raza, Aikifa; Aili, Abulimiti; Lu, Jinyou; Alghaferi, Amal; Zhang, Tiejun

    2016-05-01

    Nanostructured materials with desired wettability and optical property can play an important role in reducing the energy consumption of oily water treatment technologies. For effective oily water treatment, membrane materials with high strength, sunlight-sensitive anti-fouling, relative low fabrication cost, and controllable wettability are being explored. In the proposed oily water treatment approach, nanostructured TiO2-coated copper (TNS-Cu) meshes are used. These TNS-Cu meshes exhibit robust superhydrophilicity and underwater oleophobicity (high oil intrusion pressure) as well as excellent chemical and thermal stability (≈250 °C). They have demonstrated high separation efficiency (oil residue in the filtrate ≤21.3 ppm), remarkable filtration flux (≥400 kL h-1 m-2), and sunlight-sensitive anti-fouling properties. Both our theoretical analysis and experimental characterization have confirmed the enhanced light absorption property of TNS-Cu meshes in the visible region (40% of the solar spectrum) and consequently strong anti-fouling capability upon direct solar light illumination. With these features, the proposed approach promises great potential in treating produced oily wastewater from industry and daily life.

  12. A new family of sunlight-driven bifunctional photocatalysts based on TiO₂ nanoribbon frameworks and bismuth oxohalide nanoplates.

    Science.gov (United States)

    Cao, Xuebo; Lu, Zhufeng; Zhu, Lianwen; Yang, Le; Gu, Li; Cai, Liling; Chen, Jie

    2014-01-01

    By taking advantage of the structural affinity between bismuth oxohalide and TiO₂, we successfully prepare a family of hybrid frameworks via the designated growth of bismuth oxohalide nanoplates on TiO₂ nanoribbons, and propose them as sunlight-driven bifunctional photocatalysts for all-weather removal of pollutants. The structural variability of bismuth oxohalide allows the optical absorption of the hybrid framework to be monotonically tuneable across the visible spectrum. Meanwhile, the hybridization greatly increases the surface roughness of the frameworks and enables the frameworks to harvest more photons to participate in photocatalytic reactions. Furthermore, the hybridization establishes two potential gradients to promote the separation of photo-induced electron-hole pairs: the internal electrical field perpendicular to the wide surfaces of bismuth oxohalide nanoplates and across the semiconductor-semiconductor heterojunction. Owing to the synergetic effects of the permeable mesoporous architecture, the intense visible light absorption, and the efficient charge separation, the hybrid frameworks are capable of all-weather removal of pollutants: they utilize the inter-ribbon pores to gather pollutants in the dark (behaving as collectors) and they rapidly degrade the pollutants in the day (behaving as photocatalysts). In particular, the BiOBr@TiO₂ framework exhibits very impressive sunlight-driven photocatalytic activity, which is much higher than commercially available P25 TiO₂ under the same conditions.

  13. Mean Annual UV-B Irradiance

    Data.gov (United States)

    U.S. Environmental Protection Agency — Ultraviolet-B (UV-B) radiation is the most energetic part of sunlight reaching the Earth's surface (wavelength region is 280 to 315 nm), and it has been shown to...

  14. 1988 Annual water management plan

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Ruby Lake NWR 1987 Annual Water Management Report 1988 Annual Water Management Plan. Includes 1987 weather summary, water availability forecast, summary of 1987...

  15. Nonimaging fresnel lenses. Design and performance of solar concentrators

    Energy Technology Data Exchange (ETDEWEB)

    Leutz, R. [Tokyo Univ. of Agriculture and Technology, Koganei-shi (Japan). BASE; Suzuki, A. [UNESCO, Paris (France). Natural Science Sector

    2001-07-01

    This book offers a detailed and comprehensive account of the engineering of the world's first nonimaging Fresnel lens solar concentrator. The book closes a gap in solar concentrator design, and describes nonimaging refractive optics and its numerical mathematics. The contents follow a systems approach that is absent in standard handbooks of optics or solar energy. The reader is introduced to the principles, theories, and advantages of nonimaging optics from the standpoint of concentrating sunlight (the solar concentrator idea). The book shows the reader how to find his or her own optical solution using the rules and methodologies covering the design and the assessment of the nonimaging lens. This novel solar concentrator is developed within the natural constraints presented by the sun and in relation to competitive solutions offered by other concentrators. (orig.)

  16. The annual cycles of phytoplankton biomass

    Science.gov (United States)

    Winder, M.; Cloern, J.E.

    2010-01-01

    Terrestrial plants are powerful climate sentinels because their annual cycles of growth, reproduction and senescence are finely tuned to the annual climate cycle having a period of one year. Consistency in the seasonal phasing of terrestrial plant activity provides a relatively low-noise background from which phenological shifts can be detected and attributed to climate change. Here, we ask whether phytoplankton biomass also fluctuates over a consistent annual cycle in lake, estuarine-coastal and ocean ecosystems and whether there is a characteristic phenology of phytoplankton as a consistent phase and amplitude of variability. We compiled 125 time series of phytoplankton biomass (chloro-phyll a concentration) from temperate and subtropical zones and used wavelet analysis to extract their dominant periods of variability and the recurrence strength at those periods. Fewer than half (48%) of the series had a dominant 12-month period of variability, commonly expressed as the canonical spring-bloom pattern. About 20 per cent had a dominant six-month period of variability, commonly expressed as the spring and autumn or winter and summer blooms of temperate lakes and oceans. These annual patterns varied in recurrence strength across sites, and did not persist over the full series duration at some sites. About a third of the series had no component of variability at either the six-or 12-month period, reflecting a series of irregular pulses of biomass. These findings show that there is high variability of annual phytoplankton cycles across ecosystems, and that climate-driven annual cycles can be obscured by other drivers of population variability, including human disturbance, aperiodic weather events and strong trophic coupling between phytoplankton and their consumers. Regulation of phytoplankton biomass by multiple processes operating at multiple time scales adds complexity to the challenge of detecting climate-driven trends in aquatic ecosystems where the noise to

  17. Coal industry annual 1997

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-12-01

    Coal Industry Annual 1997 provides comprehensive information about US coal production, number of mines, prices, productivity, employment, productive capacity, and recoverable reserves. US Coal production for 1997 and previous years is based on the annual survey EIA-7A, Coal Production Report. This report presents data on coal consumption, coal distribution, coal stocks, coal prices, and coal quality for Congress, Federal and State agencies, the coal industry, and the general public. Appendix A contains a compilation of coal statistics for the major coal-producing States. This report includes a national total coal consumption for nonutility power producers that are not in the manufacturing, agriculture, mining, construction, or commercial sectors. 14 figs., 145 tabs.

  18. Renewable energy annual 1995

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-12-01

    The Renewable Energy Annual 1995 is the first in an expected series of annual reports the Energy Information Administration (EIA) intends to publish to provide a comprehensive assessment of renewable energy. This report presents the following information on the history, status, and prospects of renewable energy data: estimates of renewable resources; characterizations of renewable energy technologies; descriptions of industry infrastructures for individual technologies; evaluations of current market status; and assessments of near-term prospects for market growth. An international section is included, as well as two feature articles that discuss issues of importance for renewable energy as a whole. The report also contains a number of technical appendices and a glossary. The renewable energy sources included are biomass (wood), municipal solid waste, biomass-derived liquid fuels, geothermal, wind, and solar and photovoltaic.

  19. Annual Energy Review 2007

    Energy Technology Data Exchange (ETDEWEB)

    Seiferlein, Katherine E. [USDOE Energy Information Administration (EIA), Washington, DC (United States)

    2008-06-01

    The Annual Energy Review (AER) is the Energy Information Administration's (EIA) primary report of annual historical energy statistics. For many series, data begin with the year 1949. Included are data on total energy production, consumption, and trade; overviews of petroleum, natural gas, coal, electricity, nuclear energy, renewable energy, international energy, as well as financial and environment indicators; and data unit conversion tables. Publication of this report is required under Public Law 95–91 (Department of Energy Organization Act), Section 205(c), and is in keeping with responsibilities given to the EIA under Section 205(a)(2), which states: “The Administrator shall be responsible for carrying out a central, comprehensive, and unified energy data and information program which will collect, evaluate, assemble, analyze, and disseminate data and information....”

  20. International energy annual 1997

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-04-01

    The International Energy Annual presents an overview of key international energy trends for production, consumption, imports, and exports of primary energy commodities in over 220 countries, dependencies, and areas of special sovereignty. Also included are population and gross domestic product data, as well as prices for crude oil and petroleum products in selected countries. Renewable energy reported in the International Energy Annual includes hydroelectric power and geothermal, solar, and wind electric power. Also included are biomass electric power for Brazil and the US, and biomass, geothermal, and solar energy produced in the US and not used for electricity generation. This report is published to keep the public and other interested parties fully informed of primary energy supplies on a global basis. The data presented have been largely derived from published sources. The data have been converted to units of measurement and thermal values (Appendices E and F) familiar to the American public. 93 tabs.