Science.gov

Sample records for adding direct sunlight

  1. Direct and Indirect Phototransformation of Graphene Oxide in Sunlight

    EPA Science Inventory

    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...

  2. First direct measurement of the spatial coherence of sunlight.

    PubMed

    Mashaal, Heylal; Goldstein, Alex; Feuermann, Daniel; Gordon, Jeffrey M

    2012-09-01

    Direct sunlight is often deemed incoherent, hence unsuitable for antenna power conversion. However, all radiation exhibits spatial coherence when detected on a sufficiently small scale. We report the first direct measurement of the spatial coherence of solar beam radiation, achieved with a customized tabletop cyclic-shearing interferometer. Good agreement is found between experiment and theory, with promising ramifications for solar aperture antennas. PMID:22940934

  3. Some basic considerations of measurements involving collimated direct sunlight

    NASA Technical Reports Server (NTRS)

    Chai, A. T.

    1976-01-01

    The geometry of collimators for devices or instruments dealing with terrestrial direct sunlight is discussed. Effects of the opening angle and slope angle of a collimator on the measurements are investigated with regard to variations of turbidity and air mass. Based on this investigation, geometric dimensions for collimators and certain realistic terrestrial reference conditions are recommended for the purpose of solar cell calibration in terrestrial applications.

  4. Passive radiative cooling below ambient air temperature under direct sunlight.

    PubMed

    Raman, Aaswath P; Anoma, Marc Abou; Zhu, Linxiao; Rephaeli, Eden; Fan, Shanhui

    2014-11-27

    Cooling is a significant end-use of energy globally and a major driver of peak electricity demand. Air conditioning, for example, accounts for nearly fifteen per cent of the primary energy used by buildings in the United States. A passive cooling strategy that cools without any electricity input could therefore have a significant impact on global energy consumption. To achieve cooling one needs to be able to reach and maintain a temperature below that of the ambient air. At night, passive cooling below ambient air temperature has been demonstrated using a technique known as radiative cooling, in which a device exposed to the sky is used to radiate heat to outer space through a transparency window in the atmosphere between 8 and 13 micrometres. Peak cooling demand, however, occurs during the daytime. Daytime radiative cooling to a temperature below ambient of a surface under direct sunlight has not been achieved because sky access during the day results in heating of the radiative cooler by the Sun. Here, we experimentally demonstrate radiative cooling to nearly 5 degrees Celsius below the ambient air temperature under direct sunlight. Using a thermal photonic approach, we introduce an integrated photonic solar reflector and thermal emitter consisting of seven layers of HfO2 and SiO2 that reflects 97 per cent of incident sunlight while emitting strongly and selectively in the atmospheric transparency window. When exposed to direct sunlight exceeding 850 watts per square metre on a rooftop, the photonic radiative cooler cools to 4.9 degrees Celsius below ambient air temperature, and has a cooling power of 40.1 watts per square metre at ambient air temperature. These results demonstrate that a tailored, photonic approach can fundamentally enable new technological possibilities for energy efficiency. Further, the cold darkness of the Universe can be used as a renewable thermodynamic resource, even during the hottest hours of the day. PMID:25428501

  5. Direct sunlight facility for testing and research in HCPV

    SciTech Connect

    Sciortino, Luisa Agnello, Simonpietro Bonsignore, Gaetano; Cannas, Marco; Gelardi, Franco Mario; Napoli, Gianluca; Spallino, Luisa; Barbera, Marco; Buscemi, Alessandro; Montagnino, Fabio Maria; Paredes, Filippo; Candia, Roberto; Collura, Alfonso; Di Cicca, Gaspare; Cicero, Ugo Lo; Varisco, Salvo

    2014-09-26

    A facility for testing different components for HCPV application has been developed in the framework of 'Fotovoltaico ad Alta Efficienza' (FAE) project funded by the Sicilian Regional Authority (PO FESR Sicilia 2007/2013 4.1.1.1). The testing facility is equipped with an heliostat providing a wide solar beam inside the lab, an optical bench for mounting and aligning the HCPV components, electronic equipments to characterize the I-V curves of multijunction cells operated up to 2000 suns, a system to circulate a fluid in the heat sink at controlled temperature and flow-rate, a data logging system with sensors to measure temperatures in several locations and fluid pressures at the inlet and outlet of the heat sink, and a climatic chamber with large test volume to test assembled HCPV modules.

  6. Direct photodegradation of androstenedione and testosterone in natural sunlight: inhibition by dissolved organic matter and reduction of endocrine disrupting potential.

    PubMed

    Young, Robert B; Latch, Douglas E; Mawhinney, Douglas B; Nguyen, Thanh-Hoa; Davis, Jasmine C C; Borch, Thomas

    2013-08-01

    In surface waters, two of the most commonly observed androgenic steroid hormones are androstenedione (AD) and testosterone (T). This study compares the photodegradation of dilute (<10 μg L(-1)) aqueous solutions of AD and T in natural sunlight, and evaluates the endocrine-disrupting potential of the resulting solutions. This study also examines the effect of dissolved organic matter (DOM) on AD photodegradation. During spring and summer at Henderson, NV, USA (latitude 36.04°N), AD and T underwent direct photodegradation, with half-lives ranging from 3.7 to 10.8 h. In three model DOM solutions, AD's half-life increased by 11% to 35%. Using screening factors to eliminate DOM's inner filter effect, quantum yield calculations suggested that light screening was primarily responsible for AD's increased half-life, and that physical quenching further inhibited AD's photodegradation in two out of three DOM solutions. In vitro androgenic activity of the AD and T solutions decreased approximately as fast as AD and T were removed, suggesting that solar photodegradation reduces the risk of endocrine disruption in surface waters impacted by AD or T, subject to continuing inputs. Reduced in vitro androgenic activity appears to be related to steroid ring cleavage and the formation of highly oxidized photoproducts. PMID:23796267

  7. Direct sunlight responsive Ag-ZnO heterostructure photocatalyst: Enhanced degradation of rhodamine B

    NASA Astrophysics Data System (ADS)

    Zhai, Hongju; Wang, Lijing; Sun, Dewu; Han, Donglai; Qi, Bing; Li, Xiuyan; Chang, Limin; Yang, Jinghai

    2015-03-01

    The catalytic activity of Ag-ZnO heterostructure on the photocatalytic degradation of rhodamine B was investigated. It demonstrated that Ag-ZnO heterostructure exhibited an enhanced photocatalytic activity compared to pure ZnO nanoparticles under direct sunlight. The possible factors to the photocatalytic acitivity of the sample were explored, including Ag content, dispersity and calcination temperature. It was shown that the sample dispersed by PVP, with 5% mol ratio Ag content, calcined at 400 °C showed the highest photocatalytic acitivity and this catalyst was reusable.

  8. The significance of direct sunlight and polarized skylight in the ant's celestial system of navigation.

    PubMed

    Wehner, Rüdiger; Müller, Martin

    2006-08-15

    As textbook knowledge has it, bees and ants use polarized skylight as a backup cue whenever the main compass cue, the sun, is obscured by clouds. Here we show, by employing a unique experimental paradigm, that the celestial compass system of desert ants, Cataglyphis, relies predominantly on polarized skylight. If ants experience only parts of the polarization pattern during training but the full pattern in a subsequent test situation, they systematically deviate from their true homeward courses, with the systematics depending on what parts of the skylight patterns have been presented during training. This "signature" of the polarization compass remains unaltered, even if the ants can simultaneously experience the sun, which, if presented alone, enables the ants to select their true homeward courses. Information provided by direct sunlight and polarized skylight is picked up by different parts of the ant's compound eyes and is channeled into two rather separate systems of navigation. PMID:16888039

  9. The significance of direct sunlight and polarized skylight in the ant's celestial system of navigation

    NASA Astrophysics Data System (ADS)

    Wehner, Rüdiger; Müller, Martin

    2006-08-01

    As textbook knowledge has it, bees and ants use polarized skylight as a backup cue whenever the main compass cue, the sun, is obscured by clouds. Here we show, by employing a unique experimental paradigm, that the celestial compass system of desert ants, Cataglyphis, relies predominantly on polarized skylight. If ants experience only parts of the polarization pattern during training but the full pattern in a subsequent test situation, they systematically deviate from their true homeward courses, with the systematics depending on what parts of the skylight patterns have been presented during training. This "signature" of the polarization compass remains unaltered, even if the ants can simultaneously experience the sun, which, if presented alone, enables the ants to select their true homeward courses. Information provided by direct sunlight and polarized skylight is picked up by different parts of the ant's compound eyes and is channeled into two rather separate systems of navigation. insect vision | polarization compass | sun compass | Cataglyphis

  10. Absorption and scattering properties of carbon nanohorn-based nanofluids for direct sunlight absorbers

    PubMed Central

    2011-01-01

    In the present work, we investigated the scattering and spectrally resolved absorption properties of nanofluids consisting in aqueous and glycol 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 with respect to the pure base fluids. Scattered light was found to be not more than about 5% with respect to the total attenuation of light. 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. PACS 78.40.Ri, 78.35.+c, 78.67.Bf, 88.40.fh, 88.40.fr, 81.05.U. PMID:21711795

  11. Radiative transfer modeling of direct and diffuse sunlight in a Siberian pine forest

    NASA Astrophysics Data System (ADS)

    Alton, P. B.; North, P.; Kaduk, J.; Los, S.

    2005-12-01

    We have expanded the Monte Carlo, ray-tracing model FLIGHT in order to simulate photosynthesis within three-dimensional, heterogeneous tree canopies. In contrast to the simple radiative transfer schemes adopted in many land-surface models (e.g., the Big Leaf approximation), our simulation calculates explicitly the leaf irradiance at different heights within the canopy and thus produces an accurate scale-up in photosynthesis from leaf to canopy level. We also account for both diffuse and direct sunlight. For a Siberian stand of Scots pine Pinus sylvestris, FLIGHT predicts observed carbon assimilation, across the full range of sky radiance, with an r.m.s. error of 12%. Our main findings for this sparse canopy, using both measurements and model, are as follows: (1) Observationally, we detect a light-use efficiency (LUE) increase of only ≤10% for the canopy when the proportion of diffuse sky radiance is 75% rather than 25%. The corresponding enhancement predicted by our simulations is 10-20%. With such small increases in LUE, our site will not assimilate more carbon on overcast days compared to seasonally equivalent sunny days; (2) the scale-up in photosynthesis from top-leaf to canopy is less than unity. The Big Leaf approximation, based on Beer's law and light-acclimated leaf nitrogen, overpredicts this scale-up by ≥60% for low sky radiance (≤500 μmolPAR m-2 s-1); (3) when leaf nitrogen is distributed so as to maximize canopy photosynthesis, the increase in the canopy carbon assimilation, compared with a uniform nitrogen distribution, is small (≃4%). Maximum assimilation occurs when the vertical gradient of leaf nitrogen is slightly shallower than that of the light profile.

  12. Combustion synthesized TiO{sub 2} for enhanced photocatalytic activity under the direct sunlight-optimization of titanylnitrate synthesis

    SciTech Connect

    Daya Mani, A.; Laporte, V.; Ghosal, P.; Subrahmanyam, Ch.

    2012-09-15

    Graphical abstract: Effect of oxidant on the combustion synthesis of TiO{sub 2} has been studied by preparing titanylnitrate in four different ways from Ti(IV) iso-propoxide. It is observed that oxidant preparation method has a significant effect on physico-chemical as well as photocatalytic properties of TiO{sub 2}. All the catalysts showed excellent photocatalytic activity than Degussa P-25 under direct sunlight for the degradation of a textile dye (methylene blue), without the need of external light sources, oxygen supply and reactor systems. Highlights: ► Optimized synthesis of titanylnitrate. ► Influence of titanylnitrate synthesis on the physico-chemical properties of TiO{sub 2} prepared by combustion synthesis. ► Development of highly efficient TiO{sub 2} photocatalysts those are active under the direct sunlight in open atmosphere. ► Degradation of the textile dye (methylene blue) under direct sunlight. -- Abstract: Optimized synthesis of Ti-precursor ‘titanylnitrate’ for one step combustion synthesis of N- and C-doped TiO{sub 2} catalysts were reported and characterized by using powder X-ray diffraction (XRD), transmission electron microscopy (TEM), diffused reflectance UV–vis spectroscopy, N{sub 2} adsorption and X-ray photoelectron spectroscopy (XPS). XRD confirmed the formation of TiO{sub 2} anatase and nano-crystallite size which was further confirmed by TEM. UV-DRS confirmed the decrease in the band gap to less than 3.0 eV, which was assigned due to the presence of C and N in the framework of TiO{sub 2} as confirmed by X-ray photoelectron spectroscopy. Degradation of methylene blue in aqueous solution under the direct sunlight was carried out and typical results indicated the better performance of the synthesized catalysts than Degussa P-25.

  13. Porous graphitic carbon nitride synthesized via direct polymerization of urea for efficient sunlight-driven photocatalytic hydrogen production.

    PubMed

    Zhang, Yuewei; Liu, Jinghai; Wu, Guan; Chen, Wei

    2012-09-01

    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. PMID:22776858

  14. Sunlight Responsive Thermochromic Window System

    SciTech Connect

    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,

  15. Concentrated and piped sunlight for indoor illumination.

    PubMed

    Fraas, L M; Pyle, W R; Ryason, P R

    1983-02-15

    A concept for indoor illumination of buildings using sunlight is described. For this system, a tracking concentrator on the building roof follows the sun and focuses sunlight into a lightguide. A system of transparent lightguides distributes the sunlight to interior rooms. Recent advances in the transparency of acrylic plastic optical fibers suggest that acrylic lightguides could be successfully used for piping sunlight. The proposed system displaces electricity currently used for indoor lighting. It is argued that using sunlight directly for indoor illumination would be about twenty-five times more cost-effective than using sunlight to generate electricity with solar cells for powering electric lamps for indoor lighting. PMID:18195829

  16. Producing Hydrogen With Sunlight

    NASA Technical Reports Server (NTRS)

    Biddle, J. R.; Peterson, D. B.; Fujita, T.

    1987-01-01

    Costs high but reduced by further research. Producing hydrogen fuel on large scale from water by solar energy practical if plant costs reduced, according to study. Sunlight attractive energy source because it is free and because photon energy converts directly to chemical energy when it breaks water molecules into diatomic hydrogen and oxygen. Conversion process low in efficiency and photochemical reactor must be spread over large area, requiring large investment in plant. Economic analysis pertains to generic photochemical processes. Does not delve into details of photochemical reactor design because detailed reactor designs do not exist at this early stage of development.

  17. The value of benefit data in direct-to-consumer drug ads.

    PubMed

    Woloshin, Steven; Schwartz, Lisa M; Welch, H Gilbert

    2004-01-01

    Direct-to-consumer (DTC) pharmaceutical ads typically describe drug benefits in qualitative terms; they rarely provide data on how well the drug works. We describe an evaluation of a "prescription drug benefit box"-data from the main randomized trials on the chances of various outcomes with and without the drug. Most participants rated the information as "very important" or "important"; almost all found the data easy to understand. Perceptions of drug effectiveness were much lower for ads that incorporated the benefit box than for ads that did not. Most people we interviewed want benefit data in drug ads, can understand these data, and are influenced by them. PMID:15452006

  18. Effect of sunlight exposure on the release of intentionally and/or non-intentionally added substances from polyethylene terephthalate (PET) bottles into water: chemical analysis and in vitro toxicity.

    PubMed

    Bach, Cristina; Dauchy, Xavier; Severin, Isabelle; Munoz, Jean-François; Etienne, Serge; Chagnon, Marie-Christine

    2014-11-01

    The effect of sunlight exposure on chemical migration into PET-bottled waters was investigated. Bottled waters were exposed to natural sunlight for 2, 6 and 10 days. Migration was dependent on the type of water. Formaldehyde, acetaldehyde and Sb migration increased with sunlight exposure in ultrapure water. In carbonated waters, carbon dioxide promoted migration and only formaldehyde increased slightly due to sunlight. Since no aldehydes were detected in non-carbonated waters, we conclude that sunlight exposure has no effect. Concerning Sb, its migration levels were higher in carbonated waters. No unpredictable NIAS were identified in PET-bottled water extracts. Cyto-genotoxicity (Ames and micronucleus assays) and potential endocrine disruption effects (transcriptional-reporter gene assays) were checked in bottled water extracts using bacteria (Salmonella typhimurium) and human cell lines (HepG2 and MDA-MB453-kb2). PET-bottled water extracts did not induce any toxic effects (cyto-genotoxicity, estrogenic or anti-androgenic activity) in vitro at relevant consumer-exposure levels. PMID:24874358

  19. Changing sunlight to microwaves: A concept

    NASA Technical Reports Server (NTRS)

    Dickinson, R. M.

    1977-01-01

    Electromechanical device converts sunlight into microwave energy by direct process. Still in conceptual stage, device is expected to be lighter and more efficient (ninety percent conversion efficiency) than less-direct conversion systems that employ solar panels and magnetrons. Besides uses in satellites and spacecraft as microwave source, device has many terrestrial applications, including use in fuel-saving sun-powered microwave oven.

  20. Ghost Imaging with Sunlight

    NASA Astrophysics Data System (ADS)

    Karmakar, Sanjit

    The main result of this dissertation is the first successful experimental demonstration of ghost imaging using the sun as a light source. This result supports the quantum theory of near-field thermal light ghost imaging and also clarifies the physics of near-field thermal light ghost imaging from the fundamental level. The quantum theory of two-photon interference is the key to understanding the nonlocal ghost imaging with thermal light sources. Two-photon interference occurs between two different yet indistinguishable probability two-photon amplitudes, nonclassical entities produced by the joint-detection between two distant photodetectors. An experimental study of nontrivial spatial correlation and nontrivial anti-correlation from a pulsed chaotic-thermal source is also reported briefly in this dissertation to understand the two-photon interference phenomenon in case of classical thermal light. On the other hand, the classical theory considers thermal light ghost imaging to be the result of intensity fluctuation correlation. Interestingly, the physicists who believe in intensity fluctuation correlation was misled by the speckle-to-speckle picture. The successful experimental demonstration of ghost imaging with sunlight suggests that the nonlocal ghost-imaging effect of thermal light is caused by quantum-mechanical two-photon interference and it also proves that the idea of "speckles" is unnecessary in near-field thermal light ghost imaging. Most importantly, sunlight does not have any speckle and the sun is a near-field source. The experimental studies on sunlight-based ghost imaging are discussed in two steps: (1) an experimental demonstration as well as a quantum mechanical explanation of the nontrivial intensity correlation with the sun, a natural thermal source, as a light source and (2) the demonstration of the experimental observation of ghost imaging with sunlight with its quantum-mechanical explanation. These observations with their theoretical

  1. 21 CFR 184.1 - Substances added directly to human food affirmed as generally recognized as safe (GRAS).

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Substances added directly to human food affirmed... RECOGNIZED AS SAFE General Provisions § 184.1 Substances added directly to human food affirmed as generally... ingredient added to food does not exceed the amount reasonably required to accomplish the intended...

  2. Ultra-accelerated natural sunlight exposure testing

    DOEpatents

    Jorgensen, Gary J.; Bingham, Carl; Goggin, Rita; Lewandowski, Allan A.; Netter, Judy C.

    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.

  3. Silicon solar cell testing in concentrated sunlight and simulated sunlight

    NASA Technical Reports Server (NTRS)

    Burgess, E. L.; Mitchell, K. W.

    1976-01-01

    A method is described for testing silicon solar cells in concentrated sunlight and simulated sunlight. Concentrated sunlight is obtained by using an acrylic Fresnel lens; the simulated sunlight source is a short arc Xenon lamp. Average illumination levels during the tests are inferred from an assumed linear relationship between short circuit current and illumination. The linearity assumption is investigated for 0.3 alpha cm base resistivity silicon cells and found to be valid. Some typical results are presented to illustrate the type of information obtained during the testing.

  4. Converting Sunlight to Electricity--Some Practical Concerns

    ERIC Educational Resources Information Center

    Roman, Harry T.

    2005-01-01

    A photovoltaic panel can convert sunlight directly into electricity. If one connects enough of them in a series-parallel arrangement called a solar array, they can provide about half of a home's annual electricity needs. The panels comprise specially treated electronic materials that when exposed to sunlight will give up electrons freely, and…

  5. Disease Information in Direct-to-Consumer Prescription Drug Print Ads.

    PubMed

    Aikin, Kathryn J; Sullivan, Helen W; Betts, Kevin R

    2016-01-01

    Direct-to-consumer (DTC) prescription drug advertisements sometimes include information about the disease condition in addition to information about the advertised product. Although the intent of such information is to educate about the disease condition, in some cases consumers may mistakenly assume that the drug will address all of the potential consequences of the condition mentioned in the ad. We investigated the effects of adding disease information to DTC prescription drug print ads on consumer product perceptions and understanding. Participants (4,064 adults) viewed 1 of 15 DTC print ads for fictitious prescription drugs indicated to treat chronic obstructive pulmonary disease, anemia, or lymphoma that varied in disease information presence, type, and format. Participants answered questions that assessed risk and benefit memory, perception, and behavioral intention. Results indicate that exposure to disease information as part of DTC prescription drug ads can promote the impression that the drug addresses consequences of the condition that are not part of the drug's indication. PMID:26717304

  6. The effect of directional inertias added to pelvis and ankle on gait

    PubMed Central

    2013-01-01

    Background Gait training robots should display a minimum added inertia in order to allow normal walking. The effect of inertias in specific directions is yet unknown. We set up two experiments to assess the effect of inertia in anteroposterior (AP) direction to the ankle and AP and mediolateral (ML) direction to the pelvis. Methods We developed an experimental setup to apply inertia in forward backward and or sideways directions. In two experiments nine healthy subjects walked on a treadmill at 1.5 km/h and 4.5 km/h with no load and with AP loads of 0.3, 1.55 and 3.5 kg to the left ankle in the first experiment and combinations of AP and ML loads on the pelvis (AP loads 0.7, 4.3 and 10.2 kg; ML loads 0.6, 2.3 and 5.3 kg). We recorded metabolic rate, EMG of major leg muscles, gait parameters and kinematics. Results & discussion Adding 1.55 kg or more inertia to the ankle in AP direction increases the pelvis acceleration and decreases the foot acceleration in AP direction both at speeds of 4.5 km/h. Adding 3.5 kg of inertia to the ankle also increases the swing time as well as AP motions of the pelvis and head-arms-trunk (HAT) segment. Muscle activity remains largely unchanged. Adding 10.2 kg of inertia to the pelvis in AP direction causes a significant decrease of the pelvis and HAT segment motions, particularly at high speeds. Also the sagittal back flexion increases. Lower values of AP inertia and ML inertias up to 5.3 kg had negligible effect. In general the found effects are larger at high speeds. Conclusions We found that inertia up to 2 kg at the ankle or 6 kg added to the pelvis induced significant changes, but since these changes were all within the normal inter subject variability we considered these changes as negligible for application as rehabilitation robotics and assistive devices. PMID:23597391

  7. 21 CFR 184.1 - Substances added directly to human food affirmed as generally recognized as safe (GRAS).

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Substances added directly to human food affirmed... FOOD SUBSTANCES AFFIRMED AS GENERALLY RECOGNIZED AS SAFE General Provisions § 184.1 Substances added... and handled as a food ingredient; and that the quantity of the ingredient added to food does...

  8. 21 CFR 184.1 - Substances added directly to human food affirmed as generally recognized as safe (GRAS).

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Substances added directly to human food affirmed... FOOD SUBSTANCES AFFIRMED AS GENERALLY RECOGNIZED AS SAFE General Provisions § 184.1 Substances added... and handled as a food ingredient; and that the quantity of the ingredient added to food does...

  9. Sunlight and Vitamin D

    PubMed Central

    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

  10. Assessment of absolute added correlative coding in optical intensity modulation and direct detection channels

    NASA Astrophysics Data System (ADS)

    Dong-Nhat, Nguyen; Elsherif, Mohamed A.; Malekmohammadi, Amin

    2016-06-01

    The performance of absolute added correlative coding (AACC) modulation format with direct detection has been numerically and analytically reported, targeting metro data center interconnects. Hereby, the focus lies on the performance of the bit error rate, noise contributions, spectral efficiency, and chromatic dispersion tolerance. The signal space model of AACC, where the average electrical and optical power expressions are derived for the first time, is also delineated. The proposed modulation format was also compared to other well-known signaling, such as on-off-keying (OOK) and four-level pulse-amplitude modulation, at the same bit rate in a directly modulated vertical-cavity surface-emitting laser-based transmission system. The comparison results show a clear advantage of AACC in achieving longer fiber delivery distance due to the higher dispersion tolerance.

  11. 21 CFR 184.1 - Substances added directly to human food affirmed as generally recognized as safe (GRAS).

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Substances added directly to human food affirmed as..., DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) DIRECT FOOD... human food affirmed as generally recognized as safe (GRAS). (a) The direct human food ingredients...

  12. 21 CFR 184.1 - Substances added directly to human food affirmed as generally recognized as safe (GRAS).

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Substances added directly to human food affirmed as generally recognized as safe (GRAS). 184.1 Section 184.1 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) DIRECT FOOD SUBSTANCES AFFIRMED AS GENERALLY...

  13. Stigma-reducing components in direct-to-consumer prescription ads: onset controllability, offset controllability, and recategorization.

    PubMed

    An, Soontae; Kang, Hannah

    2011-01-01

    This study analyzed direct-to-consumer (DTC) print ads for stigmatized illnesses from 1998 to 2008. Attribution theory and recategorization theory were used as theoretical frames to assess whether those DTC ads contained message components to reduce stigma. DTC ads for 10 stigmatized illnesses in National Geographic, Better Homes and Gardens, Ladies' Home Journal, and Time were analyzed for the presence of onset controllability, offset controllability, and recategorization. Results showed that only 3.7% of ads offered the three message components together and, in fact, 21% of the ads did not contain any of the stigma-reducing message elements. Recategorization cue was the most prevalent component, while cues for onset and offset controllability were relatively less frequent, indicating the lack of educational components. PMID:21442502

  14. Sunlight Simulator for Photovoltaic Testing

    NASA Technical Reports Server (NTRS)

    Mueller, R. L.

    1986-01-01

    Light with normalized spectral irradiance resembling that of airmass 1.5 sunlight striking surface of Earth produced by use of ultraviolet filter to modify output of set of flashlamps used as large-area pulsed solar simulator (LAPSS). Filtered LAPSS light allows more realistic measurements of output of photovoltaic devices when using silicon reference cell having different spectral response characteristic.

  15. Peer Relationship Problems of Children with AD/HD: Risk Factors and New Directions in Interventions

    ERIC Educational Resources Information Center

    Ozdemir, Selda

    2009-01-01

    This review integrates and evaluates research conducted on possible contributing factors to peer relationship problems of children with attention deficit/hyperactivity disorder (AD/HD). Substantial evidence suggests that children with AD/HD have serious problems in multiple aspects of their relationships with peers. Difficulties resulting from…

  16. Sunlight-energy-storing method

    SciTech Connect

    Kitao, T.; Ishihara, Sh.; Setsune, J.I.; Yamamoto, R.

    1984-05-22

    This invention is a method for storing light energy using an indigo derivative. Among indigo derivatives capable of storing light energy by the photoisomerization of the molecule from the trans-form to the cis-form, compounds heretofore obtained have been soluble only in expensive solvents such as benzene, toluene, chloroform, carbon tetrachloride and the like and harmful substances. On the other hand, the indigo derivative of this invention has the form of a pyridinium salt, is soluble in water and/or ethanol, and permits employment of safe and inexpensive water and/or an alcohol as a solvent. The indigo derivative of this invention converted from the trans-form to the cis-form by irradiation with sunlight and storing sunlight energy liberates the aforesaid stored energy as heat on addition of a catalyst and/or a heat trigger.

  17. Exposure of organic extracts of air particulates to sunlight leads to metabolic activation independence for mutagenicity.

    PubMed

    al-Khodairy, F; Hannan, M A

    1997-06-13

    Air particulates were collected on Whatman, GFA glass fibre filters using a RADECO constant-flow air sampler from a car-parking basement and an open roadside adjacent to the basement. While the basement was not exposed to sunlight, the roadside from where air samples were collected was exposed to regular daylight in the month of July (peak summer month). The filters were soaked and sonicated in acetone to dislodge the particulates and then a residue was obtained after evaporation of acetone. The residues were either held in dark or exposed to natural sunlight or germicidal UV light before being tested for mutagenicity using the Salmonella tester strain TA98 with and without metabolic activation (S9 mix). The results showed that the addition of S9 mix resulted in only a slight increase in the frequency of histidine revertants/plate in the case of daylight-exposed roadside air samples. On the other hand, a considerable increase in mutagenicity was observed in the case of the basement air samples, particularly at higher concentrations of the organic extracts when S9 mix was added. However, a pre-exposure of the organic extract of air from the basement to sunlight abrogated the need for S9 mix for showing mutagenic activity. A pre-exposure of the same extracts to germicidal UV light failed to produce a similar effect. These results suggested that long wavelengths of natural sunlight could be responsible for the conversion of certain promutagens in air particulates into direct-acting mutagens. The environmental impact of solar radiation as a modifier of air particulate mutagens in high-sun countries like Saudi Arabia needs to be carefully considered for assessment of air pollution-related health risks. PMID:9219550

  18. Consumers' Understanding of FDA Approval Requirements and Composite Scores in Direct-to-Consumer Prescription Drug Print Ads.

    PubMed

    O'Donoghue, Amie C; Sullivan, Helen W; Williams, Pamela A; Squire, Claudia; Betts, Kevin R; Fitts Willoughby, Jessica; Parvanta, Sarah

    2016-08-01

    In 2 studies, we investigated how laypersons perceive the Food and Drug Administration (FDA) approval process, FDA authority, and the presentation of composite scores in direct-to-consumer (DTC) prescription drug print ads. The 1st study consisted of 4 focus groups (N = 38) in 2 cities. Using a semi-structured guide, a moderator led participants through the viewing of 3 existing DTC print ads that differed in the presence or absence of composite score information, and participants discussed their views of the ads and their understanding of composite scores. The 2nd study surveyed a nationally representative sample of 1,629 individuals from the general population who saw a fictitious DTC print ad and answered closed-ended questions about the same topics. Results showed that knowledge of FDA approval and authority was mixed, with several misconceptions apparent. Many consumers were not familiar with the use of composite scores in a medical context or in advertising and, in the 1st study, expressed distrust of the product and the ad after learning about how composite scores are used. In the 2nd study, receiving composite score information changed the perceived clarity of the ad but not the perceived risk or benefits. Implications for the presentation of complex medical information are discussed. PMID:27414000

  19. Uniform sunlight concentration reflectors for photovoltaic cells.

    PubMed

    Rabady, Rabi Ibrahim

    2014-03-20

    Sunlight concentration is essential to reach high temperatures of a working fluid in solar-thermal applications and to reduce the cost of photovoltaic (PV) electricity generation systems. Commonly, sunlight concentration is realized by parabolic or cylindrical reflectors, which do not provide uniform concentration on the receiver finite surface. Uniform concentration of sunlight is favored especially for the PV conversion applications since it not only enhances the conversion efficiency of sunlight but also reduces the thermal variations along the receiving PV cell, which can be a performance and life-span limiting factor. In this paper a reflector profile that uniformly infiltrates the concentrated sunlight into the receiving unit is attempted. The new design accounts for all factors that contribute to the nonuniform concentration, like the reflector curvature, which spatially reflects the sunlight nonuniformly, and the angular dependency of both the reflector reflectivity and the sunlight transmission through the PV cell. PMID:24663464

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

    ERIC Educational Resources Information Center

    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…

  1. Sunlight and human conjunctival action spectrum

    NASA Astrophysics Data System (ADS)

    Cullen, Anthony P.; Perera, Sharmila C.

    1994-07-01

    Retrospective epidemiological studies implicate solar ultraviolet as a contributing factor in several human corneal/conjunctival disorders including spheroidal degeneration, pterygium and pinguecula. The inferior bulbar(ocular) conjunctivae of 64 human volunteers were irradiated with narrow band ultraviolet radiation biomicroscopy, differential in vivo staining, and impression cytology. The conjunctival response was symptomless and characterized by injection, chemosis, damaged epithelial cells, and the presence of inflammatory cells. The action spectrum showed a similar response to that for human corneal epithelium but with slightly lower damage thresholds (3mJcm-2at 270 nm). No response was produced at 330 nm. Irradiance levels were the same order of magnitude as solar UVB and these results suggest the sub-clinical damage would be produced within minutes of direct exposure to sunlight. The potential for repeated conjunctival trauma supports the hypothesis that chronic exposure to enviornmental UVR contributes to degenerative changes in the cornea and conjunctiva.

  2. Direct test of the AdS/CFT correspondence by Monte Carlo studies of super Yang-Mills theory

    NASA Astrophysics Data System (ADS)

    Honda, Masazumi; Ishiki, Goro; Kim, Sang-Woo; Nishimura, Jun; Tsuchiya, Asato

    2013-11-01

    We perform nonperturbative studies of super Yang-Mills theory by Monte Carlo simulation. In particular, we calculate the correlation functions of chiral primary operators to test the AdS/CFT correspondence. Our results agree with the predictions obtained from the AdS side that the SUSY non-renormalization property is obeyed by the three-point functions but not by the four-point functions investigated in this paper. Instead of the lattice regularization, we use a novel regularization of the theory based on an equivalence in the large- N limit between the SU( N) theory on R × S 3 and a one-dimensional SU( N) gauge theory known as the plane-wave (BMN) matrix model. The equivalence extends the idea of large- N reduction to a curved space and, at the same time, overcomes the obstacle related to the center symmetry breaking. The adopted regularization for S 3 preserves 16 SUSY, which is crucial in testing the AdS/CFT correspondence with the available computer resources. The only SUSY breaking effects, which come from the momentum cutoff Λ in R direction, are made negligible by using sufficiently large Λ.

  3. Technique to separate lidar signal and sunlight.

    PubMed

    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. PMID:27410314

  4. Sunlight-into-energy conversion apparatus

    SciTech Connect

    Kuwano, Y.; Yamano, M.

    1982-06-08

    The present application discloses a sunlight-into-energy conversion apparatus in which at least one amorphous silicon solar cell having a thickness thin enough to permit the sunlight to pass therethrough is formed on the surface of a heat collecting plate attached to a heating medium tube in a thermal conductive manner, thereby permitting the sunlight to be effectively converted into thermal energy and electrical energy. When a plurality of such amorphous silicon solar cells are formed on the surface of the heat collecting plate through insulating films, respectively and connected in series to each other, high electromotive force may be obtained.

  5. Hybrid Solar Lighting - Fiber Optics Brings Sunlight Inside

    SciTech Connect

    Maxey, L Curt

    2008-01-01

    Hybrid solar lighting systems focus highly concentrated sunlight into a fiber optic bundle to provide sunlight in rooms without windows or conventional skylights. The flexible sunlight bundles are easily routed through small openings and around obstacles to carry the light to where it is needed. The optical fibers terminate in hybrid luminaires where the sunlight is combined with electric light that is automatically adjusted to keep the overall light level constant within the lighted area. The hybrid solar lighting concept was originally proposed at Oak Ridge National Laboratory in Tennessee in the mid-1990s, but funding hurdles prevented the idea from seeing daylight for more than five years. Hybrid solar lighting was touted as a means for using solar energy directly without any conversion losses and for increasing the visual quality of interior lighting. As such, it promised to be both energy-efficient and aesthetically appealing, but its technical complexity made potential sponsors wary. They had to be convinced that the lighting concept could be accepted into the marketplace and that the systems could be manufactured at an acceptable cost. An earlier fiber-coupled daylighting system marketed in the early 1990s used expensive quartz optical fibers to distribute the light and served only a niche market that was willing to pay a premium for the novelty. By contrast, the hybrid solar lighting system proposed using inexpensive plastic optical fibers to distribute the light to hybrid (sunlight/electric) luminaires that would be visually and functionally identical to conventional luminaires. In this way, the lighting could be integrated seamlessly into existing design concepts and thus easily embraced by architects and lighting designers as a means for offering daylight as a lighting option.

  6. Spectral comparisons of sunlight and different lamps

    NASA Technical Reports Server (NTRS)

    Deitzer, Gerald

    1994-01-01

    The tables in this report were compiled to characterize the spectra of available lamp types and provide comparison to the spectra of sunlight. Table 1 reports the spectral distributions for various lamp sources and compares them to those measured for sunlight. Table 2 provides the amount of energy in Wm(exp -2) relative to the number of photons of PAR (photosynthetically active radiation) (400-700 nm) for each light source.

  7. Opposition Surge: Sunlight Glinting off Mars

    NASA Technical Reports Server (NTRS)

    1998-01-01

    Mars Global Surveyor was presented with a unique opportunity February 13-18, 1998, to image sunlight glinting off of the surface and atmospheric haze of Mars. Orbits 130-137 were devoted to obtaining MOC images of this effect, also known as opposition surge. During each orbit in mid-February, the Mars Global Surveyor spacecraft passed close to and through the line between the Sun and the center of Mars. In other words, the phase angle (angle between the Sun's incident light and the direction from the surface to the spacecraft) was near zero degrees. The sunlight reflecting from Mars near the zero phase angle produces the rare sun-glint phenomenon. The size and brightness of the glint depends on the physical properties of the surface (dust, sand, and rock distribution) and the atmosphere (haze/suspended dust). Studies of these images are expected to yield important information that can be compared with thermal emission observations.

    The picture is a color composite of MOC images 13601 (red wide angle) and 13602 (blue wide angle). The green-color band is synthesized from the red and blue using a relationship well-understood from Viking images of the late 1970s. The large, dark region near the top-center of the picture is Sinus Meridiani. The circular feature at the upper right is the impact basin, Schiaparelli. The opposition surge feature --the sun glint-- is centered around 21.0oS latitude, 4.1oW longitude.

    The two images were taken on Mars Global Surveyor's 136th orbit on February 18, 1998. Orbit 136 was the second-to-last orbit on which MOC obtained images of Mars during the first aerobraking phase (AB-1) of the mission. MOC was off between the end of AB-1 on February 19, 1998, until the start of Science Phasing Orbit-1 phase (SPO-1), which began March 28 and ended April 28, 1998.

    Malin Space Science Systems and the California Institute of Technology built the MOC using spare hardware from the Mars Observer mission. MSSS operates the camera from its

  8. Efficient Solar Concentrators: Affordable Energy from Water and Sunlight

    SciTech Connect

    2010-01-01

    Broad Funding Opportunity Announcement Project: Teledyne is developing a liquid prism panel that tracks the position of the sun to help efficiently concentrate its light onto a solar cell to produce power. Typically, solar tracking devices have bulky and expensive mechanical moving parts that require a lot of power and are often unreliable. Teledyne’s liquid prism panel has no bulky and heavy supporting parts—instead it relies on electrowetting. Electrowetting is a process where an electric field is applied to the liquid to control the angle at which it meets the sunlight above and to control the angle of the sunlight to the focusing lensthe more direct the angle to the focusing lens, the more efficiently the light can be concentrated to solar panels and converted into electricity. This allows the prism to be tuned like a radio to track the sun across the sky and steer sunlight into the solar cell without any moving mechanical parts. This process uses very little power and requires no expensive supporting hardware or moving parts, enabling efficient and quiet rooftop operation for integration into buildings.

  9. DNA damage profiles induced by sunlight at different latitudes.

    PubMed

    Schuch, André Passaglia; Yagura, Teiti; Makita, Kazuo; Yamamoto, Hiromasa; Schuch, Nelson Jorge; Agnez-Lima, Lucymara Fassarella; MacMahon, Ricardo Monreal; Menck, Carlos Frederico Martins

    2012-04-01

    Despite growing knowledge on the biological effects of ultraviolet (UV) radiation on human health and ecosystems, it is still difficult to predict the negative impacts of the increasing incidence of solar UV radiation in a scenario of global warming and climate changes. Hence, the development and application of DNA-based biological sensors to monitor the solar UV radiation under different environmental conditions is of increasing importance. With a mind to rendering a molecular view-point of the genotoxic impact of sunlight, field experiments were undertaken with a DNA-dosimeter system in parallel with physical photometry of solar UVB/UVA radiation, at various latitudes in South America. On applying biochemical and immunological approaches based on specific DNA-repair enzymes and antibodies, for evaluating sunlight-induced DNA damage profiles, it became clear that the genotoxic potential of sunlight does indeed vary according to latitude. Notwithstanding, while induction of oxidized DNA bases is directly dependent on an increase in latitude, the generation of 6-4PPs is inversely so, whereby the latter can be regarded as a biomolecular marker of UVB incidence. This molecular DNA lesion-pattern largely reflects the relative incidence of UVA and UVB energy at any specific latitude. Hereby is demonstrated the applicability of this DNA-based biosensor for additional, continuous field experiments, as a means of registering variations in the genotoxic impact of solar UV radiation. PMID:22674547

  10. Sunlight-Induced Coloration of Silk.

    PubMed

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

    2016-12-01

    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. PMID:27297220

  11. Sunlight-Induced Coloration of Silk

    NASA Astrophysics Data System (ADS)

    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.

  12. Sunlight Diffusing Tent for Lunar Worksite

    NASA Technical Reports Server (NTRS)

    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.

  13. Selling Health to the Distracted: Consumer Responses to Source Credibility and Ad Appeal Type in a Direct-to-Consumer Advertisement.

    PubMed

    Lemanski, Jennifer L; Villegas, Jorge

    2015-01-01

    Since 1997, when the U.S. Food and Drug Administration first allowed prescription drug companies to release ads directly targeting the public, direct-to-consumer (DTC) advertising has become an integral part of the pharmaceutical industry marketing toolkit, reaching over $4 billion in 2005. In an experiment where cognitive load, a task that requires the investment of a subject's memory in an unrelated task; source credibility; and advertising appeal type (affective or cognitive) were manipulated, attitude toward the ad was measured for a print DTC meningitis vaccine ad. Main effect results for source credibility and advertising appeal type on attitude toward the ad were found, and interactions between manipulated variables were apparent when the individual difference variables related to a specific illness (vaccination history, living in a dorm, family members or friends who had suffered the illness) were taken into account. PMID:26368298

  14. Photochemical Transformation of Graphene Oxide in Sunlight

    EPA Science Inventory

    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...

  15. Photochemical transformation of graphene oxide in sunlight.

    PubMed

    Hou, Wen-Che; Chowdhury, Indranil; Goodwin, David G; Henderson, W Matthew; Fairbrother, D Howard; Bouchard, Dermont; Zepp, Richard G

    2015-03-17

    Graphene oxide (GO) is promising in scalable production and has useful properties that include semiconducting behavior, catalytic reactivity, and aqueous dispersibility. In this study, we investigated the photochemical fate of GO under environmentally relevant sunlight conditions. The results indicate that GO readily photoreacts under simulated sunlight with the potential involvement of electron-hole pair creation. GO was shown to photodisproportionate to CO2, reduced materials similar to reduced GO (rGO) that are fragmented compared to the starting material, and low molecular-weight (LMW) species. Kinetic studies show that the rate of the initially rapid photoreaction of GO is insensitive to the dissolved oxygen content. In contrast, at longer time points (>10 h), the presence of dissolved oxygen led to a greater production of CO2 than the same GO material under N2-saturated conditions. Regardless, the rGO species themselves persist after extended irradiation equivalent to 2 months in natural sunlight, even in the presence of dissolved oxygen. Overall, our findings indicate that GO phototransforms rapidly under sunlight exposure, resulting in chemically reduced and persistent photoproducts that are likely to exhibit transport and toxic properties unique from parent GO. PMID:25671674

  16. Boom potential of a rotating satellite in sunlight

    NASA Technical Reports Server (NTRS)

    Lai, S. T.; Cohen, H. A.; Aggson, T. L.; Mcneil, W. J.

    1986-01-01

    An interpretation is provided for the behavior of long boom potential measurements taken on the spinning P78-2 (SCATHA) satellite at near geosynchronous altitudes. This study uses data taken during a quiet day, with the satellite in sunlight. The data show periodic variations with a maximum amplitude of 6 V. The theory explains why the variations correlate well with sun direction but not with the geomagnetic field. A current balance model, assuming a Maxwellian distribution of photoelectrons, is studied. The photoelectron temperature, the degrees of positive charging of the boom and of the satellite, and the ambient electron flux are calculated. Deviations from the model are discussed.

  17. Toxic photoproducts of phenanthrene and anthracene in sunlight

    SciTech Connect

    Duxbury, C.L.; McConkey, B.J.; Mallakin, A.; Dixon, D.G.; Greenberg, B.M.

    1995-12-31

    Phenanthrene and anthracene, two of the most prevalent PAHs, undergo significant increases in toxicity on exposure to sunlight. Over a period of several days exposure to light, the toxicity of an aqueous solution of phenanthrene or anthracene increased dramatically. This increase in toxicity is largely due to the primary products formed by these two PAHs due to light exposure. These compounds are more toxic than the parent compounds at equimolar concentrations. Although anthracene is a potent photosensitizer, phenanthrene did not exhibit a significant increase in toxicity due to photosensitization. Photo-oxidation was the principal cause of photoinduced toxicity, with 9,10-phenanthrenequinone being the primary product. This compound is more water soluble than phenanthrene increasing its bioavailability. In addition, mixtures of phenanthrene and 9,10-phenanthrenequinone exhibited toxicity similar to the quinone added alone. This was shown by joint toxicity testing using Lemna gibba and Daphnia magna. These two organisms are currently being used in the lab to further test individual oxidized products of anthracene and phenanthrene that occur as a result of exposure to sunlight.

  18. Association of sunlight exposure and photoprotection measures with clinical outcome in systemic lupus erythematosus.

    PubMed

    Vilá, L M; Mayor, A M; Valentín, A H; Rodríguez, S I; Reyes, M L; Acosta, E; Vilá, S

    1999-06-01

    This study was designed to explore the relationship of sunlight exposure and ultraviolet (UV) light protection measures with clinical outcome in systemic lupus erythematosus (SLE). A structured questionnaire was administered to sixty Puerto Rican SLE patients, to assess their attitudes and behavior regarding sunlight exposure and photoprotection measures. Medical records were reviewed to evaluate the clinical outcome measures that included: clinical manifestations, number of SLE-related hospitalizations, number of exacerbations and pharmacologic treatment. Almost all (98.3%) patients were well acquainted of sunlight effects on disease activity. Two thirds were exposed to direct sunlight for an average of less than one hour per day and 33.3% for one hour or more. Thirty patients (50%) reported use of sunscreen, with sun protective factor of 15 or greater, when exposed to sunlight. Less than 40% of patients regularly wore hat or long-sleeves clothes to protect from sunlight. Although there were some clinical differences between the groups with different sunlight exposure times, none reached statistical significance. Also, no significant differences were found between the groups in regards to sunlight protective clothes. However, patients that regularly used sunscreen had significantly lower renal involvement (13.3 vs 43.3%), thrombocytopenia (13.3 vs 40%), hospitalizations (26.7 vs. 76.7%), and requirement of cyclophosphamide treatment (6.7 vs. 30%) than patients that did not used it (P < 0.05). We conclude that use of sunscreen photoprotection was associated with a better clinical outcome in our SLE patients. These findings further support the importance and benefits of photoprotective measures in patients with SLE. PMID:10461313

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

    PubMed Central

    Hwang, Jung Min; Oh, Se Hyun

    2016-01-01

    Purpose 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. Methods We performed a questionnaire-based survey on allergic diseases among elementary school students. Birth time was categorized according to the season (summer and winter). Results 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; P<0.001; allergic rhinitis [AR]: aOR, 1.4; 95% CI, 1.17-1.67; P<0.001; AD: aOR, 1.26; 95% CI, 1.06-1.51; P=0.01). Neither recent sunlight exposure nor exercise duration was associated with the prevalence of an allergic disease. Conclusion 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. PMID:27279886

  20. Natural sunlight accelerated weathering of photovoltaic modules

    NASA Astrophysics Data System (ADS)

    Zerlaut, G. A.; Anderson, T. B.; Arnett, J. C.

    Photovoltaic modules are exposed to the equivalent of ten years of sunlight aging in an accelerated exposure testing and evaluation program, the objective being to determine the long-term durability characteristics of flat plate modules in comparatively short periods of time. The modules are illuminated with concentrated sunlight in a large, sun-tracking, Fresnel-reflecting solar concentrator. The effects of the accelerated exposure are assessed by performing periodic visual inspections and electrical measurements. It is found that field-experienced failure modes are duplicated, that acceleration factors of 6x to 8x are readily attainable, and that the test method is feasible as a predictive tool for photovoltaic module lifetime durability.

  1. Natural sunlight accelerated weathering of photovoltaic modules

    NASA Technical Reports Server (NTRS)

    Zerlaut, G. A.; Anderson, T. B.; Arnett, J. C.

    1981-01-01

    Photovoltaic modules are exposed to the equivalent of ten years of sunlight aging in an accelerated exposure testing and evaluation program, the objective being to determine the long-term durability characteristics of flat plate modules in comparatively short periods of time. The modules are illuminated with concentrated sunlight in a large, sun-tracking, Fresnel-reflecting solar concentrator. The effects of the accelerated exposure are assessed by performing periodic visual inspections and electrical measurements. It is found that field-experienced failure modes are duplicated, that acceleration factors of 6x to 8x are readily attainable, and that the test method is feasible as a predictive tool for photovoltaic module lifetime durability.

  2. Sunlight induced 685 nm fluorescence imagery

    NASA Technical Reports Server (NTRS)

    Kim, Hongsuk H.; Van Der Piepen, Heinz

    1986-01-01

    The capability of a new fluorescence method is evaluated using data from an aircraft fluorescence experiment conducted on the Elbe River on August 10-14, 1981. The technique measures chlorophyll concentrations by monitoring sunlight-induced fluorescence at 685 nm. Upwelling radiance spectra and vertical profiles of upwelling radiances are presented and analyzed. The image-processing algorithm used to retrieve fluorescence signals from raw data is described.

  3. Manned Mars mission sunlight and communication occultations

    NASA Technical Reports Server (NTRS)

    Mulqueen, Jack

    1986-01-01

    Calculations are presented for the 1999 opposition class mission and a procedure for obtaining singlar occultation data for any other given Mars mission is given. Occultation data for a Mars orbiter in a 24.5 hour parking orbit and a Mars base were calculated for: sunlight occultation - the time in darkness; and radio communication occultation - the communication losses between the lander and the orbiter, the lander and Earth, and orbiter and Earth.

  4. Circular polarization of sunlight reflected by clouds.

    NASA Technical Reports Server (NTRS)

    Hansen, J. E.

    1971-01-01

    Measurements of circular polarization of visible light from planets have recently been reported. It is pointed out that the values measured for the circular polarization for Jupiter and Venus are of the magnitude expected for sunlight reflected by a cloudy planetary atmosphere. The variations of the sense of the polarization with phase angle and with location on the planetary disk are also consistent with expectations for reflection by clouds.

  5. Effects of sunlight on bacteriophage viability and structure.

    PubMed Central

    Wommack, K E; Hill, R T; Muller, T A; Colwell, R R

    1996-01-01

    Current estimates of viral abundance in natural waters rely on direct counts of virus-like particles (VLPs), using either transmission or epifluorescence microscopy. Direct counts of VLPs, while useful in studies of viral ecology, do not indicate whether the observed VLPs are capable of infection and/or replication. Rapid decay in bacteriophage viability under environmental conditions has been observed. However, it has not been firmly established whether there is a corresponding degradation of the virus particles. To address this question, viable and direct counts were carried out employing two Chesapeake Bay bacteriophages in experimental microcosms incubated for 56 h at two depths in the York River estuary. Viruses incubated in situ in microcosms at the surface yielded decay rates in full sunlight of 0.11 and 0.06 h-1 for CB 38 phi and CB 7 phi, respectively. The number of infective particles in microcosms in the dark and at a depth of 1 m was not significantly different from laboratory controls, with decay rates averaging 0.052 h-1 for CB 38 phi and 0.037 h-1 for CB 7 phi. Direct counts of bacteriophages decreased in teh estuarine microcosms, albeit only at a rate of 0.028 h-1, and were independent of treatment. Destruction of virus particles is concluded to be a process separate from loss of infectivity. It is also concluded that strong sunlight affects the viability of bacteriophages in surface waters, with the result that direct counts of VLPs overestimate the number of bacteriophage capable of both infection and replication. However, in deeper waters, where solar radiation is not a significant factor, direct counts should more accurately estimate numbers of viable bacteriophage. PMID:8919794

  6. Sunlight photolysis of benzotriazoles - Identification of transformation products and pathways.

    PubMed

    Weidauer, Cindy; Davis, Caroline; Raeke, Julia; Seiwert, Bettina; Reemtsma, Thorsten

    2016-07-01

    Benzotriazoles (BTs) are widely used corrosion inhibitors, incompletely removed in municipal wastewater treatment. The photochemical fate of the three BTs 1H-benzotriazole (1H-BT), 4-methyl-1H-benzotriazole (4Me-BT) and 5-methyl-1H-benzotriazole (5Me-BT) and of three microbial metabolites, was studied under simulated sunlight (290-800 nm) at neutral pH in aqueous solution for 24 h. The half-life, the quantum yield and the reaction rate were determined and a total of 36 photolysis products were detected and identified using liquid chromatography-high resolution-mass spectrometry. The half-lives of all six BTs were in the range of 6-24 h under the experimental conditions. Though the quantum yields were comparatively low (0.0007-0.0021), the environmental half-lives ranged from 2.4 to 8 d, suggesting that sunlight photolysis is still a relevant degradation process of BTs in surface waters. The photolysis pathway of 1H-BT under simulated sunlight differed from that suggested for UV-radiation, in that aminophenol is formed directly rather than via aniline. Similar pathways were found for the other BTs, except for 4-hydroxy-1H-benzotriazole (4OH-BT). Most identified transformation products of the BTs showed a high reactivity and appear not to persist in the environment. Upon co-photolysis of BTs with dissolved organic matter (DOM), however, series of reaction products were determined by Fourier transform - ion cyclotron resonance - mass spectrometry (FTICR-MS) which are formed by reaction of photolysis intermediates of the BTs with DOM. PMID:27081795

  7. Sunlight Damage To The Solitary Ascidian Chelyosoma productum

    NASA Astrophysics Data System (ADS)

    Flores, E.

    2004-12-01

    Chelyosoma productum (Stimpson) is a temperate solitary ascidian commonly found in Puget Sound and the San Juan Archipelago, Washington, USA. Adult populations are restricted to deeper subtidal regions or shaded shallow-water habitats, such as docks in shaded marinas. C. productum adults have a thin translucent outer tunic that may provide very little if any protection from solar damage. I hypothesized that sunlight may be setting limits on the distribution of this species. Since adult ascidians are sessile and rely on earlier life stages for their distribution, all life stages of Chelyosoma productum were tested. In this study, I examined the effects of sunlight exposure in embryos, larvae, juveniles and adults of Chelyosoma productum. I isolated the PAR, UVA and UVB portions of the spectrum and exposed all life stages using natural sunlight. I also sampled shallow-water dock habitats to see how adult distributions were related to light exposure. The embryonic development in C. productum was negatively affected by any solar exposure. Most embryos exposed to UV light failed to develop normally and those that did could not subsequently settle. This species produces embryos of different colors; two (purple and brown) were observed in my experiments. Damage from light exposure differed between the color morphs. Overall, the brown morph was more tolerant of light exposure than was the purple morph across all life stages. The only exception to this general pattern was that purple embryos were remarkably resistant to light damage. The distribution of C. productum is restricted to areas with no direct solar exposure. However, even within shaded environments where they were abundant, subpopulations related to the color dimorphism were observed. The significance of the brown and purple pigments in embryos and larvae remains largely unknown. However, adults with brown eggs were found to be more prevalent in edge environments where there was higher light exposure. Purple

  8. Energy from Water and Sunlight: Affordable Energy from Water and Sunlight

    SciTech Connect

    2010-01-01

    Broad Funding Opportunity Announcement Project: Sun Catalytix is developing wireless energy-storage devices that convert sunlight and water into renewable fuel. Learning from nature, one such device mimics the ability of a tree leaf to convert sunlight into storable energy. It is comprised of a silicon solar cell coated with catalytic materials, which help speed up the energy conversion process. When this cell is placed in a container of water and exposed to sunlight, it splits the water into bubbles of oxygen and hydrogen. The hydrogen and oxygen can later be recombined to create electricity, when the sun goes down for example. The Sun Catalytix device is novel in many ways: it consists primarily of low-cost, earth-abundant materials where other attempts have required more expensive materials like platinum. Its operating conditions also facilitate the use of less costly construction materials, whereas other efforts have required extremely corrosive conditions.

  9. Aerosol scattering of ultraviolet sunlight in the tropical maritime atmosphere

    NASA Technical Reports Server (NTRS)

    Ghazi, A.; Krueger, A. J.; Fraser, R. S.

    1973-01-01

    The effects of atmospheric aerosol scattering on the vertical profile of solar ultraviolet radiation are investigated. Measurements of diffuse and total ultraviolet radiation were made using a rocketborne optical sonde in the marine atmosphere of Antigua. During observations, the sun was at zenith. Vertical profiles of directly transmitted solar radiation were calculated by subtraction of the diffuse component from the total radiance. Using these values of direct downward solar UV-flux, the optical thickness of the atmosphere was derived as a function of altitude. Absorption by ozone was also considered. In the troposphere the values of observed optical thickness were in general equal to or lower than those expected theoretically from Rayleigh scattering alone. The measured radiation profiles were compared with those computed for a multiple scattering model atmosphere. Some computations regarding the interaction of UV-sunlight with maritime aerosols are presented.

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

    PubMed Central

    An, Mihyang; Colarelli, Stephen M.; O'Brien, Kimberly; Boyajian, Melanie E.

    2016-01-01

    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. PMID:27214041

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

    PubMed

    An, Mihyang; Colarelli, Stephen M; O'Brien, Kimberly; Boyajian, Melanie E

    2016-01-01

    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. PMID:27214041

  12. SUNLIGHT AND IRON(III)-INDUCED PHOTOCHEMICAL PRODUCTION OF DISSOLVED GASEOUS MERCURY IN FRESHWATER. (R827632)

    EPA Science Inventory

    Mechanistic understanding of sunlight-induced natural processes for
    production of dissolved gaseous mercury (DGM) in freshwaters has remained
    limited, and few direct field tests of the mechanistic hypotheses are available.
    We exposed ferric iron salt-spiked fresh s...

  13. Sunlight readability of displays: a numerical scale

    NASA Astrophysics Data System (ADS)

    Sharpe, Robert; Cartwright, Colin M.; Gillespie, W. Allan; Vassie, Ken; Christopher, W. Colin

    2003-07-01

    There is a great deal of interest in the sunlight readability of displays. How to quantify this, particularly on a numerical scale rather than pass/fail is an important consideration. Some military standards exist e.g. MIL-L-85762A but are these appropriate to non-military products? We report the use of a method developed by BAE SYSTEMS, the model is based on our ability to see things by virtue of a difference in either luminance or chrominance, or both. The model uses a method called PJND (Perceptible Just Noticeable Difference), based on LJND (Luminance Just Noticeable Difference) and CJND (Chrominance Just Noticeable Difference) thresholds. The basis of this model is a series of acceptance criteria established by subjects in a realistic environment; BAE SYSTEMS have an Ambient Lighting Facility (ALF) which simulates many lighting scenarios that are likely to be encountered in real life. Product mock-ups were taken into this environment and subjects were asked to choose levels of acceptance for differing screen presentations and various lighting geometries. The method results in a single figure of readability, which in effect summarizes the task and environment. This figure can then form the basis of a specification between display supplier and vendor. We plan to develop the model such that it should be possible to predict the best combination of treatments to apply to the display surface to give the optimum and most cost effective sunlight readable display for a given application and product.

  14. Use of sunlight to partially detoxify groundnut (peanut) cake flour and casein contaminated with aflatoxin B1

    SciTech Connect

    Shantha, T.; Murthy, V.S.

    1981-03-01

    Sunlight destroyed 83 and 50% of the toxin added to casein and groundnut cake flour, respectively. Equilibrium dialysis revealed that both casein and groundnut protein bind aflatoxin but the toxin bound to casein appeared more photo-labile than that bound to groundnut protein.

  15. The influence of sunlight irradiation on the characteristics of InGaAs detectors

    NASA Astrophysics Data System (ADS)

    Shao, Xiumei; Zhu, Yaoming; Li, Xue; Tang, Hengjing; Li, Tao; Gong, Haimei

    2014-10-01

    InGaAs ternary compound is suitable for detector applications in the shortwave infrared (SWIR) band. Due to the advantages of good stability, low cooling requirements and high detectivity, InGaAs detectors have been applied widely in the space remote sensing area. However, InGaAs detectors would be affected by strong sunlight direct irradiation in space application. In this paper, a mesa-type InGaAs detector with large sensitive area of diameter 5mm was designed based on InP/In0.53Ga0.47As/InP epitaxial material, which is lattice-matched to InP substrate. The InGaAs detectors were fabricated by ICP etching, and packaged in a Kovar shell. The relative spectral response is in the range of 0.9μm to 1.7μm. The mechanism of the sunlight direct irradiation on InGaAs detector performance was studied. The sunlight were focalized by lens and irradiated directly on the detector. A piece of epitaxial material was investigated at the same time which was cleaved from a 2 inch wafer, same to the detector material. The real time testing was taken out to observe the output signal of the detector. After the irradiation experiment, the I-V curves and the relative response were tested immediately. The dark current of the detector increased temporarily, but come back to the original level after 24 hours. The response spectrum was nearly not affected. The XRD testing of the epitaxial material sample was carried out before and after sunlight direct irradiation. The sunlight irradiation causes thermal stress degradation. The thermal electrons were produced by the absorption of a great deal of visible light, leading to local enhancement of temperature and the lattice degeneration of the material.

  16. Sunlight-induced carbon dioxide emissions from inland waters

    NASA Astrophysics Data System (ADS)

    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

  17. Direct observations of transition dynamics from macro- to micro-phase separation in asymmetric lipid bilayers induced by externally added glycolipids

    NASA Astrophysics Data System (ADS)

    Shimobayashi, Shunsuke F.; Ichikawa, Masatoshi; Taniguchi, Takashi

    2016-03-01

    We present the first direct observations of morphological transitions from macro- to micro-phase separation using micrometer-sized asymmetric lipid vesicles exposed to externally added glycolipids (GM1:monosialotetrahexosylganglioside). The transition occurs via an intermediate stripe morphology state. During the transition, monodisperse micro-domains emerge through repeated scission events of the stripe domains. Moreover, we numerically confirmed such transitions using a time-dependent Ginzburg-Landau model, which describes both the intramembrane phase separation and the bending elastic membrane. The experimental and simulation results are in quantitative agreement.

  18. AdS orbifolds and Penrose limits

    SciTech Connect

    Alishahiha, Mohsen; Sheikh-Jabbari, Mohammad M.; Tatar, Radu

    2002-12-09

    In this paper we study the Penrose limit of AdS{sub 5} orbifolds. The orbifold can be either in the pure spatial directions or space and time directions. For the AdS{sub 5}/{Lambda} x S{sup 5} spatial orbifold we observe that after the Penrose limit we obtain the same result as the Penrose limit of AdS{sub 5} x S{sup 5}/{Lambda}. We identify the corresponding BMN operators in terms of operators of the gauge theory on R x S{sup 3}/{Lambda}. The semi-classical description of rotating strings in these backgrounds have also been studied. For the spatial AdS orbifold we show that in the quadratic order the obtained action for the fluctuations is the same as that in S{sup 5} orbifold, however, the higher loop correction can distinguish between two cases.

  19. Sunlight modulates the relative importance of heterotrophic bacteria and picophytoplankton in DMSP-sulphur uptake

    PubMed Central

    Ruiz-González, Clara; Simó, Rafel; Vila-Costa, Maria; Sommaruga, Ruben; Gasol, Josep M

    2012-01-01

    There is a large body of evidence supporting a major role of heterotrophic bacteria in dimethylsulphoniopropionate (DMSP) utilisation as a source of reduced sulphur. However, a role for phototrophic microorganisms has been only recently described and little is known about their contribution to DMSP consumption and the potential modulating effects of sunlight. In an attempt to ascertain the relative quantitative roles of heterotrophic bacteria and picophytoplankton in the osmoheterotrophic uptake of DMSP-sulphur upon exposure to natural sunlight conditions, we incubated northwestern Mediterranean waters under various optical filters and used an array of bulk and single-cell activity methods to trace the fate of added 35S-DMSP. Flow cytometry cell sorting confirmed dark 35S uptake by Prochlorococcus, Synechococcus and heterotrophic bacteria, the latter being the most efficient in terms of uptake on a cell volume basis. Under exposure to full sunlight, however, the relative contribution of Synechococcus was significantly enhanced, mainly because of the inhibition of heterotrophic bacteria. Microautoradiography showed a strong increase in the proportion of Synechococcus cells actively taking up 35S-DMSP, which, after full sunlight exposure, made up to 15% of total active Bacteria. Parallel incubations with 3H-leucine generally showed no clear responses to light. Finally, size-fractionated assimilation experiments showed greater relative cyanobacterial assimilation during the day than at night compared with that of heterotrophic bacteria. Our results show for the first time a major influence of sunlight in regulating the competition among autotrophic and heterotrophic picoplankton for DMSP uptake at both the daily and seasonal time scales. PMID:21955992

  20. Proteomic analysis of grape berry skin responding to sunlight exclusion.

    PubMed

    Niu, Ning; Cao, Yuegang; Duan, Wei; Wu, Benhong; Li, Shaohua

    2013-05-15

    The most obvious effect of sunlight exclusion from grape clusters is the inhibition of anthocyanin biosynthesis in the berry skin so that no color develops. Two-dimensional gel electrophoresis coupled with mass spectrometry was used to characterize the proteins isolated from berry skins that developed under sunlight exclusion versus those from sunlight-exposed berries. Among more than 1500 spots resolved in stained gels, the accumulation patterns of 96 spots differed significantly between sunlight-excluded berry skin and that of sunlight-exposed control berries. Seventy-two proteins, including 35 down-regulated and 37 up-regulated proteins, were identified and categorized. Proteins involved in photosynthesis and secondary metabolism, especially UDP-glucose:flavonoid 3-O-glucosyltransferase (UFGT), the key step for anthocyanin biosynthesis in grape berry skin, were accumulated less in the absence of sunlight. Several isoforms of heat shock proteins were also down-regulated. The proteins that were over-accumulated in sunlight-excluded berry skin were more often related to energy production, glycolysis, the tricarboxylic-acid cycle, protein synthesis and biogenesis of cellular components. Their putative role is discussed in terms of their relevance to sunlight exclusion processes. PMID:23499453

  1. Autonomous artificial nanomotor powered by sunlight

    NASA Astrophysics Data System (ADS)

    Balzani, Vincenzo; Clemente-León, Miguel; Credi, Alberto; Ferrer, Belén; Venturi, Margherita; Flood, Amar H.; Fraser Stoddart, J.

    2006-01-01

    Light excitation powers the reversible shuttling movement of the ring component of a rotaxane between two stations located at a 1.3-nm distance on its dumbbell-shaped component. The photoinduced shuttling movement, which occurs in solution, is based on a "four-stroke" synchronized sequence of electronic and nuclear processes. At room temperature the deactivation time of the high-energy charge-transfer state obtained by light excitation is 10 μs, and the time period required for the ring-displacement process is on the order of 100 μs. The rotaxane behaves as an autonomous linear motor and operates with a quantum efficiency up to 12%. The investigated system is a unique example of an artificial linear nanomotor because it gathers together the following features: (i) it is powered by visible light (e.g., sunlight); (ii) it exhibits autonomous behavior, like motor proteins; (iii) it does not generate waste products; (iv) its operation can rely only on intramolecular processes, allowing in principle operation at the single-molecule level; (v) it can be driven at a frequency of 1 kHz; (vi) it works in mild environmental conditions (i.e., fluid solution at ambient temperature); and (vii) it is stable for at least 103 cycles. molecular machine | nanoscience | photochemistry | rotaxane | supramolecular chemistry


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

    PubMed

    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. PMID:27316765

  3. BrAD-seq: Breath Adapter Directional sequencing: a streamlined, ultra-simple and fast library preparation protocol for strand specific mRNA library construction.

    PubMed

    Townsley, Brad T; Covington, Michael F; Ichihashi, Yasunori; Zumstein, Kristina; Sinha, Neelima R

    2015-01-01

    Next Generation Sequencing (NGS) is driving rapid advancement in biological understanding and RNA-sequencing (RNA-seq) has become an indispensable tool for biology and medicine. There is a growing need for access to these technologies although preparation of NGS libraries remains a bottleneck to wider adoption. Here we report a novel method for the production of strand specific RNA-seq libraries utilizing the terminal breathing of double-stranded cDNA to capture and incorporate a sequencing adapter. Breath Adapter Directional sequencing (BrAD-seq) reduces sample handling and requires far fewer enzymatic steps than most available methods to produce high quality strand-specific RNA-seq libraries. The method we present is optimized for 3-prime Digital Gene Expression (DGE) libraries and can easily extend to full transcript coverage shotgun (SHO) type strand-specific libraries and is modularized to accommodate a diversity of RNA and DNA input materials. BrAD-seq offers a highly streamlined and inexpensive option for RNA-seq libraries. PMID:26052336

  4. Smeared antibranes polarise in AdS

    NASA Astrophysics Data System (ADS)

    Gautason, Fridrik Freyr; Truijen, Brecht; Van Riet, Thomas

    2015-07-01

    In the recent literature it has been questioned whether the local backreaction of antibranes in flux throats can induce a perturbative brane-flux decay. Most evidence for this can be gathered for D6 branes and D p branes smeared over 6 - p compact directions, in line with the absence of finite temperature solutions for these cases. The solutions in the literature have flat worldvolume geometries and non-compact transversal spaces. In this paper we consider what happens when the worldvolume is AdS and the transversal space is compact. We show that in these circumstances brane polarisation smoothens out the flux singularity, which is an indication that brane-flux decay is prevented. This is consistent with the fact that the cosmological constant would be less negative after brane-flux decay. Our results extend recent results on AdS7 solutions from D6 branes to AdS p+1 solutions from D p branes. We show that supersymmetry of the AdS solutions depend on p non-trivially.

  5. Evidence of sensitized photolysis of polychlorinated dibenzo-p-dioxins in natural waters under sunlight conditions

    SciTech Connect

    Friesen, K.J.; Webster, G.R.B. ); Muir, D.C.G. )

    1990-11-01

    The sunlight photolysis of carbon-14 labeled 1,2,3,4,7-pentachlorodibenzo-p-dioxin (P{sub 5}CDD) and 1,2,3,4,6,7,8-heptachlorodibenzo-p-dioxin (H{sub 7}CDD) was studied at 50{degree} N latitude in filter-sterilized natural water and in distilled water-acetonitrile (2:3, v/v) solutions to determine the extent of direct versus indirect photolysis under environmental conditions. Under midsummer sunlight conditions, pseudo-first-order sunlight photolysis rate constants (k{sub p}) of 0.74 and 0.28 day{sup {minus}1} were measured for P{sub 5}CDD and H{sub 7}CDD, respectively, in natural water. However, considerably slower direct aqueous photolysis rates were observed for the two PCDD congeners in distilled water-acetonitrile, with rate constants of 0.058 and 0.019 day{sup {minus}1} for P{sub 5}CDD and H{sub 7}CDD, respectively, in relatively good agreement with predicted rates of direct aqueous photolysis. The results indicate that an indirect or sensitized photolytic mechanism may dominate the photodegradation of PCDDs in natural waters. The major degradation product(s) appeared as nonextractable {sup 14}C activity, with increases in this fraction paralleling the disappearance of the parent PCDD.

  6. Value Added?

    ERIC Educational Resources Information Center

    UCLA IDEA, 2012

    2012-01-01

    Value added measures (VAM) uses changes in student test scores to determine how much "value" an individual teacher has "added" to student growth during the school year. Some policymakers, school districts, and educational advocates have applauded VAM as a straightforward measure of teacher effectiveness: the better a teacher, the better students…

  7. Brevetoxin Degradation and By-Product Formation via Natural Sunlight

    PubMed Central

    Hardman, Ron C.; Cooper, William J.; Bourdelais, Andrea J.; Gardinali, Piero; Baden, Daniel G.

    2010-01-01

    We investigated the effects of solar radiation on brevetoxin (PbTx2). Our findings suggest that natural sunlight mediates brevetoxin (PbTx2) degradation and results in brevetoxin by-product formation via photochemical processes. PMID:26436141

  8. Charles Burchfield: "October Wind and Sunlight in the Woods."

    ERIC Educational Resources Information Center

    Fitzgerald, Gaynell

    1986-01-01

    Based on Charles Burchfield's watercolor, "October Wind and Sunlight in the Woods," the goal of this lesson is to introduce students in grades seven through nine to Burchfield's use of symbolism. (JDH)

  9. Isophotes of sunlight glitter on a wind-ruffled sea.

    PubMed

    Plass, G N; Kattawar, G W; Guinn, J A

    1977-03-01

    Time-averaged intensities are computed for the glitter pattern of sunlight on a wind-ruffled sea. Isopleths are drawn from these on graphs which simulate glitter-pattern photographs through projections of sea-surface grid points on an inclined plane assumed to be in front of the observer. The intensity computed for each grid point is based on a calculation of the wave-surface orientation required for direct reflection from source to observer at that point; the probability of occurrence of this orientation, determined from the Cox-Munk distribution, is the principal factor in the computed intensity. The curvature of the earth is taken into account, and calculations are made for various cases of source elevation angle, observer altitude, and wind speed (the controlling parameter for the distribution of wave inclinations). Percent polarization is computed for the glitter patterns, and projected isopleths of this quantity are plotted. The effects of variations in wind speed, source elevation angle, and observer height on the morphology of the glitter pattern are shown, and such phenomena as the shifting of a reflected image toward the horizon are clearly demonstrated. It is suggested that the technique developed here could be useful in evaluating models of ocean wave structure and in making remote determinations of the sea state in the region of the glitter pattern. PMID:20168556

  10. Direct and correlated responses to selection in two lines of rabbits selected for feed efficiency under ad libitum and restricted feeding: I. Production traits and gut microbiota characteristics.

    PubMed

    Drouilhet, L; Achard, C S; Zemb, O; Molette, C; Gidenne, T; Larzul, C; Ruesche, J; Tircazes, A; Segura, M; Bouchez, T; Theau-Clément, M; Joly, T; Balmisse, E; Garreau, H; Gilbert, H

    2016-01-01

    To get insights into selection criteria for feed efficiency, 2 rabbit lines have been created: the ConsoResidual line was selected for residual feed intake (RFI) with ad libitum feeding and the ADGrestrict line was selected for ADG under restricted feeding (-20% of voluntary intake). The first objective of this study was to evaluate, after 9 generations of selection, the direct and correlated responses to selection on production traits in the 2 lines for traits recorded during growth. Second, applying the 2 feeding conditions used for selection to both selected lines plus the control unselected line (generation 0, G0) in a 2 × 3 factorial trial, the line performances were compared and the gut microbiota of the lines was characterized. The correlated responses in feed conversion ratio (FCR) were remarkably equivalent in both selected lines (-2.74 genetic σ) but correlated responses in other traits were notably different. In the ConsoResidual line, selection for decreased RFI resulted in a small negative correlated response in BW at 63 d old (BW63) and in a null response in ADG. In the ADGrestrict line, on the contrary, the correlated response in BW63 was substantial (+1.59 σ). The 2 selected lines had a FCR reduced by 0.2 point compared with the G0 line, and the same difference was found in both feeding regimens ( < 0.001). Indeed, selection on ADG would lead to heavier animals with no significant reduction of feed costs, whereas selection on RFI leads to lower feed costs and no increase of animal BW under ad libitum feeding. Altogether, our results do not suggest any genotype × environment interaction in the response to feeding regimens. The intestinal microbial communities from efficient rabbits differed from their unselected counterparts in terms of fermentation end products and microbial phylotypes, suggesting a central role of these microbes in the better feed efficiency of the rabbits. PMID:26812310

  11. Semiconductor nanoparticle-based hydrogels prepared via self-initiated polymerization under sunlight, even visible light

    PubMed Central

    Zhang, Da; Yang, Jinhu; Bao, Song; Wu, Qingsheng; Wang, Qigang

    2013-01-01

    Since ancient times, people have used photosynthesized wood, bamboo, and cotton as building and clothing materials. The advantages of photo polymerization include the mild and easy process. However, the direct use of available sunlight for the preparation of materials is still a challenge due to its rather dilute intensity. Here, we show that semiconductor nanoparticles can be used for initiating monomer polymerization under sunlight and for cross-linking to form nanocomposite hydrogels with the aid of clay nanosheets. Hydrogels are an emerging multifunctional platform because they can be easily prepared using solar energy, retain semiconductor nanoparticle properties after immobilization, exhibit excellent mechanical strength (maximum compressive strength of 4.153 MPa and tensile strength 1.535 MPa) and high elasticity (maximum elongation of 2784%), and enable recyclable photodegradation of pollutants. This work suggests that functional nanoparticles can be immobilized in hydrogels for their collective application after combining their mechanical and physiochemical properties. PMID:23466566

  12. Reflected Sunlight Reduction and Characterization for a Deep-Space Optical Receiver Antenna (DSORA)

    NASA Technical Reports Server (NTRS)

    Clymer, B. D.

    1990-01-01

    A baffle system for the elimination of first-order specular and diffuse reflection of sunlight from the sunshade of a deep-space optical receiver telescope is presented. This baffle system consists of rings of 0.5cm blades spaced 2.5 cm apart on the walls of GO hexagonal sunshade tubes that combine to form the telescope sunshade. The shadow cast by the blades, walls, and rims of the tubes prevent all first-order reflections of direct sunlight from reaching the primary mirror of the telescope. A reflection model of the sunshade without baffles is also presented for comparison. Since manufacturers of absorbing surfaces do not measure data near grazing incidence, the reflection properties at anticipated angles of incidence must be characterized. A description of reflection from matte surfaces in term of bidirectional reflection distribution function (BRDF) is presented along with a discussion of measuring BRDF near grazing incidence.

  13. Semiconductor nanoparticle-based hydrogels prepared via self-initiated polymerization under sunlight, even visible light.

    PubMed

    Zhang, Da; Yang, Jinhu; Bao, Song; Wu, Qingsheng; Wang, Qigang

    2013-01-01

    Since ancient times, people have used photosynthesized wood, bamboo, and cotton as building and clothing materials. The advantages of photo polymerization include the mild and easy process. However, the direct use of available sunlight for the preparation of materials is still a challenge due to its rather dilute intensity. Here, we show that semiconductor nanoparticles can be used for initiating monomer polymerization under sunlight and for cross-linking to form nanocomposite hydrogels with the aid of clay nanosheets. Hydrogels are an emerging multifunctional platform because they can be easily prepared using solar energy, retain semiconductor nanoparticle properties after immobilization, exhibit excellent mechanical strength (maximum compressive strength of 4.153 MPa and tensile strength 1.535 MPa) and high elasticity (maximum elongation of 2784%), and enable recyclable photodegradation of pollutants. This work suggests that functional nanoparticles can be immobilized in hydrogels for their collective application after combining their mechanical and physiochemical properties. PMID:23466566

  14. Contribution of UVB radiation to bacterial inactivation by natural sunlight.

    PubMed

    Oppezzo, Oscar J

    2012-10-01

    The contribution of different components of sunlight to the lethal action exerted by this radiation on bacteria was studied using Pseudomonas aeruginosa ATCC27853 as a model organism. When solar UVB was excluded from the incident radiation by filtering it through a naphthalene solution (cut off 327 nm), significant modifications were observed in the cell-death kinetics. These modifications were comparable to those expected for a reduction of 27-32% in the dose rate, according to the model used in the analysis of the survival curves, and were also observed when the effects of sunlight filtered through polyethylene terephthalate (cut off 331 nm) or polystyrene (cut off 298 nm) were compared. Viability of P. aeruginosa remained almost unchanged when the incident radiation was filtered through a sodium nitrite solution (cut off 406 nm) in order to exclude the UVA and UVB components of sunlight. Nevertheless, a delay in colony formation was detected in bacteria treated in this way, suggesting that a non-lethal effect was exerted by visible light. The results are not consistent with a generally accepted notion which attributes the lethal action of sunlight to the radiation with wavelengths above 320 nm. The characterization of UVB contribution to the lethal effect of sunlight on bacteria is relevant for understanding of the mechanism of cell death, and for improvement of dosimetry techniques and irradiation procedures. PMID:22819168

  15. Sunlight and breast cancer incidence in the USSR.

    PubMed

    Gorham, E D; Garland, F C; Garland, C F

    1990-12-01

    Epidemiological and laboratory evidence suggest that vitamin D may play a role in reducing risk of breast cancer. Lack of exposure to ultraviolet sunlight can increase the prevalence of vitamin D deficiency, and may place some populations at higher risk of breast cancer. The association between total average annual sunlight energy striking the ground and age-adjusted breast cancer incidence rates in the USSR was evaluated. Breast cancer had a threefold range of incidence. Sunlight levels varied from 210 to 400 calories per cm2 per day. A statistically significant negative association was found between breast cancer incidence rates and total sunlight levels (R = -0.75, p = 0.001). The slope of the regression line corresponded to two additional cases per 100,000 per year for each reduction of 35 calories per cm2 of sunlight. The pattern of increased breast cancer incidence in regions of low solar radiation in the USSR is consistent with the geographical pattern seen for breast cancer mortality in the US and worldwide. A positive relationship between socioeconomic status and breast cancer incidence was also present in the Soviet Union, based on an approximate socioeconomic measure, the number of doctors per 1000 population (R = +0.89, p = 0.0001). The possibility that correlates of socioeconomic status, such as dietary, ethnic, or behavioural factors, could account for the association is discussed. PMID:2084008

  16. Mutagenicity of the sunlight-exposed sample of pyrene in Salmonella typhimurium TA98

    SciTech Connect

    Takeda, N.; Teranishi, K.; Hamada, K.

    1984-10-01

    In addition to chemical and biochemical transformations of PAHs in simulated conditions, it has been reported that PAHs associated with airborne particles are readily photooxidized in real atmosphere. These studies prompted us to investigate a relation between the photodegradation of PAHs in the real atmospheric environment and the resultant mutagenicity of their degradation products. In this paper, the authors describe the transformation of pyrene into directly active mutagen following exposure to sunlight in the real atmosphere and the presence of directly active mutagens in the oxygenated and acidic fractions of the exposed sample of pyrene.

  17. Ultra-accelerated natural sunlight exposure testing facilities

    DOEpatents

    Lewandowski, Allan A.; Jorgensen, Gary J.

    2003-08-12

    A multi-faceted concentrator apparatus for providing ultra-accelerated natural sunlight exposure testing for sample materials under controlled weathering conditions comprising: facets that receive incident natural sunlight, transmits VIS/NIR and reflects UV/VIS to deliver a uniform flux of UV/VIS onto a sample exposure plane located near a center of a facet array in chamber means that provide concurrent levels of temperature and/or relative humidity at high levels of up to 100.times. of natural sunlight that allow sample materials to be subjected to accelerated irradiance exposure factors for a significant period of time of about 3 to 10 days to provide a corresponding time of about at least a years worth representative weathering of sample materials.

  18. Ultra-Accelerated Natural Sunlight Exposure Testing Facilities

    DOEpatents

    Lewandowski, Allan A.; Jorgensen, Gary J.

    2004-11-23

    A multi-faceted concentrator apparatus for providing ultra-accelerated natural sunlight exposure testing for sample materials under controlled weathering conditions comprising: facets that receive incident natural sunlight, transmits VIS/NIR and reflects UV/VIS onto a secondary reflector that delivers a uniform flux of UV/VIS onto a sample exposure plane located near a center of a facet array in a chamber that provide concurrent levels of temperature and/or relative humidity at high levels of up to 100.times. of natural sunlight that allow sample materials to be subjected to accelerated irradiance exposure factors for a significant period of time of about 3 to 10 days to provide a corresponding time of about at least a years worth representative weathering of sample materials.

  19. Smart filters: operational HMD even at bright sunlight conditions

    NASA Astrophysics Data System (ADS)

    Donval, Ariela; Gross, Noam; Partouche, Eran; Dotan, Ido; Lipman, Ofir; Oron, Moshe

    2014-06-01

    A typical Head Mounted Display (HMD) has either one or two small displays with relevant optics embedded in a helmet, eye-glasses (also known as data glasses) or visor. See-through HMDs provide the ability of superimposed the generated image on a real-world view. When using a see-through HMD at a very bright day, the display image risks vanishing due to the sun illumination. However, at a very cloudy day, one needs all the light to pass through the display to the user eye. The need to control the amount of sunlight passes through the HMD in a passive way was the trigger for our effort in developing Dynamic Sunlight Filter (DSF™). DSF™ is a passive solution which is dedicated to regulate sunlight overpower events.

  20. Adding Value.

    ERIC Educational Resources Information Center

    Orsini, Larry L.; Hudack, Lawrence R.; Zekan, Donald L.

    1999-01-01

    The value-added statement (VAS), relatively unknown in the United States, is used in financial reports by many European companies. Saint Bonaventure University (New York) has adapted a VAS to make it appropriate for not-for-profit universities by identifying stakeholder groups (students, faculty, administrators/support personnel, creditors, the…

  1. Mechanism, kinetics, and pathways of self-sensitized sunlight photodegradation of phenylarsonic compounds.

    PubMed

    Xie, Xiande; Hu, Yuanan; Cheng, Hefa

    2016-06-01

    Being highly water-soluble, phenylarsonic feed additives discharged in animal wastes can easily accumulate in surface water bodies. The photodegradation mechanism, kinetics, and pathways of p-arsanilic acid (p-ASA), 4-hydrophenylarsonic acid (4-HPAA), and phenylarsonic acid (PAA) in water under simulated and natural sunlight irradiation were investigated. The -AsO(OH)2 group was cleaved from the aromatic ring during photodegradation, and p-benzoquinone and p-hydroquinone were formed as the major organic degradation intermediates. Experimental results did not indicate any significant direct photolysis of the phenylarsonic compounds under simulated and natural sunlight irradiation, but consistently showed that they sensitized the formation of singlet oxygen, which was responsible for their photodegradation and oxidation of the As(III) released. A simple (1)O2-based "heterogeneous" model was developed, which could well describe the kinetics of (1)O2 formation and phenylarsonic compound photodegradation under various conditions. Indirect photolysis caused by inorganic ions commonly present in natural waters was negligible, while natural organic matter could significantly inhibit their photodegradation. The half-lives of p-ASA, 4-HPAA, and PAA photodegradation under simulated sunlight irradiation (765 W m(-2), 25 °C) were 11.82 ± 0.19, 20.06 ± 0.10, and 135 ± 6.0 min, respectively, while their degradation rates under natural sunlight in the Pearl River Delta of southern China were 5 times slower due to lower irradiation intensity and water temperatures (19-23 °C). PMID:27038583

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

    PubMed

    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. PMID:20452021

  3. Sunlight supply and gas exchange systems in microalgal bioreactor

    NASA Technical Reports Server (NTRS)

    Mori, K.; Ohya, H.; Matsumoto, K.; Furune, H.

    1987-01-01

    The bioreactor with sunlight supply system and gas exchange systems presented has proved feasible in ground tests and shows much promise for space use as a closed ecological life support system device. The chief conclusions concerning the specification of total system needed for a life support system for a man in a space station are the following: (1) Sunlight supply system - compactness and low electrical consumption; (2) Bioreactor system - high density and growth rate of chlorella; and (3) Gas exchange system - enough for O2 production and CO2 assimilation.

  4. DIS in AdS

    NASA Astrophysics Data System (ADS)

    Albacete, Javier L.; Kovchegov, Yuri V.; Taliotis, Anastasios

    2009-03-01

    We calculate the total cross section for the scattering of a quark-anti-quark dipole on a large nucleus at high energy for a strongly coupled N = 4 super Yang-Mills theory using AdS/CFT correspondence. We model the nucleus by a metric of a shock wave in AdS5. We then calculate the expectation value of the Wilson loop (the dipole) by finding the extrema of the Nambu-Goto action for an open string attached to the quark and antiquark lines of the loop in the background of an AdS5 shock wave. We find two physically meaningful extremal string configurations. For both solutions we obtain the forward scattering amplitude N for the quark dipole-nucleus scattering. We study the onset of unitarity with increasing center-of-mass energy and transverse size of the dipole: we observe that for both solutions the saturation scale Qs is independent of energy/Bjorken-x and depends on the atomic number of the nucleus as Qs˜A1/3. Finally we observe that while one of the solutions we found corresponds to the pomeron intercept of αP = 2 found earlier in the literature, when extended to higher energy or larger dipole sizes it violates the black disk limit. The other solution we found respects the black disk limit and yields the pomeron intercept of αP = 1.5. We thus conjecture that the right pomeron intercept in gauge theories at strong coupling may be αP = 1.5.

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

    EPA Science Inventory

    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...

  6. Sunlight Photochemistry: The Preparation of Dicarbonyl (n5-methylcyclopentadienyl) Triphenylphosphinemanganese.

    ERIC Educational Resources Information Center

    Calabro, David C.; Lichtenberger, Dennis L.

    1982-01-01

    Background information, materials/procedures, and results are provided for an undergraduate laboratory experiment on a photochemical ligand substitution reaction using sunlight. The experiment illustrates demonstration of photochemistry and basic mechanisms of transition metal reactions using inexpensive materials and is easily followed by…

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

    PubMed

    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. PMID:26750730

  8. Probing crunching AdS cosmologies

    NASA Astrophysics Data System (ADS)

    Kumar, S. Prem; Vaganov, Vladislav

    2016-02-01

    Holographic gravity duals of deformations of CFTs formulated on de Sitter spacetime contain FRW geometries behind a horizon, with cosmological big crunch singularities. Using a specific analytically tractable solution within a particular single scalar truncation of {N}=8 supergravity on AdS4, we first probe such crunching cosmologies with spacelike radial geodesics that compute spatially antipodal correlators of large dimension boundary operators. At late times, the geodesics lie on the FRW slice of maximal expansion behind the horizon. The late time two-point functions factorise, and when transformed to the Einstein static universe, they exhibit a temporal non-analyticity determined by the maximal value of the scale factor ã max. Radial geodesics connecting antipodal points necessarily have de Sitter energy Ɛ ≲ ã max, while geodesics with Ɛ > ã max terminate at the crunch, the two categories of geodesics being separated by the maximal expansion slice. The spacelike crunch singularity is curved "outward" in the Penrose diagram for the deformed AdS backgrounds, and thus geodesic limits of the antipodal correlators do not directly probe the crunch. Beyond the geodesic limit, we point out that the scalar wave equation, analytically continued into the FRW patch, has a potential which is singular at the crunch along with complex WKB turning points in the vicinity of the FRW crunch. We then argue that the frequency space Green's function has a branch point determined by ã max which corresponds to the lowest quasinormal frequency.

  9. Transformation of acesulfame in water under natural sunlight: joint effect of photolysis and biodegradation.

    PubMed

    Gan, Zhiwei; Sun, Hongwen; Wang, Ruonan; Hu, Hongwei; Zhang, Pengfei; Ren, Xinhao

    2014-11-01

    The transformation of acesulfame in water under environmentally relevant conditions, including direct and indirect photolysis, biodegradation, and hydrolysis, was systematically evaluated. Under natural sunlight, both direct and indirect photolysis of acesulfame were negligible in sterilized systems at neutral or alkaline pH, whereas direct photolysis occurred at pH of 4 with a rate constant of 0.0355 d(-1) in deionized water. No significant reduction in acesulfame contents was found in the dark controls or in the incubation experiments, indicating acesulfame was resistant to hydrolysis and biodegradation. In unsterilized systems, photolysis was substantially enhanced, implying that there was a joint effect of photolysis and biodegradation or that the sterilization process had the secondary effect of inactivating some photosensitizers. The near-surface summer half-life of acesulfame in the water from the Haihe River was 9 d. Specific experiments revealed the involvement of (1)O2/(3)DOM* in acesulfame photolysis, whereas OH exhibited only a slight contribution in the presence of DOM or bicarbonate. As indicated by the total organic carbon data, no significant mineralization occurred in both sterilized and unsterilized systems after acesulfame was irradiated under simulated sunlight for 7 d, suggesting the generation of persistent intermediates. Finally, major degradation intermediates were analyzed, and the degradation pathways of acesulfame under environmentally relevant conditions were proposed for the first time. PMID:25046375

  10. DIS in AdS

    SciTech Connect

    Albacete, Javier L.; Kovchegov, Yuri V.; Taliotis, Anastasios

    2009-03-23

    We calculate the total cross section for the scattering of a quark-anti-quark dipole on a large nucleus at high energy for a strongly coupled N = 4 super Yang-Mills theory using AdS/CFT correspondence. We model the nucleus by a metric of a shock wave in AdS{sub 5}. We then calculate the expectation value of the Wilson loop (the dipole) by finding the extrema of the Nambu-Goto action for an open string attached to the quark and antiquark lines of the loop in the background of an AdS{sub 5} shock wave. We find two physically meaningful extremal string configurations. For both solutions we obtain the forward scattering amplitude N for the quark dipole-nucleus scattering. We study the onset of unitarity with increasing center-of-mass energy and transverse size of the dipole: we observe that for both solutions the saturation scale Q{sub s} is independent of energy/Bjorken-x and depends on the atomic number of the nucleus as Q{sub s}{approx}A{sup 1/3}. Finally we observe that while one of the solutions we found corresponds to the pomeron intercept of {alpha}{sub P} = 2 found earlier in the literature, when extended to higher energy or larger dipole sizes it violates the black disk limit. The other solution we found respects the black disk limit and yields the pomeron intercept of {alpha}{sub P} = 1.5. We thus conjecture that the right pomeron intercept in gauge theories at strong coupling may be {alpha}{sub P} = 1.5.

  11. Bubbling AdS3

    NASA Astrophysics Data System (ADS)

    Martelli, Dario; Morales, Jose F.

    2005-02-01

    In the light of the recent Lin, Lunin, Maldacena (LLM) results, we investigate 1/2-BPS geometries in minimal (and next to minimal) supergravity in D = 6 dimensions. In the case of minimal supergravity, solutions are given by fibrations of a two-torus T2 specified by two harmonic functions. For a rectangular torus the two functions are related by a non-linear equation with rare solutions: AdS3 × S3, the pp-wave and the multi-center string. ``Bubbling'', i.e. superpositions of droplets, is accommodated by allowing the complex structure of the T2 to vary over the base. The analysis is repeated in the presence of a tensor multiplet and similar conclusions are reached, with generic solutions describing D1D5 (or their dual fundamental string-momentum) systems. In this framework, the profile of the dual fundamental string-momentum system is identified with the boundaries of the droplets in a two-dimensional plane.

  12. A chaotic self-oscillating sunlight-driven polymer actuator

    NASA Astrophysics Data System (ADS)

    Kumar, Kamlesh; Knie, Christopher; Bléger, David; Peletier, Mark A.; Friedrich, Heiner; Hecht, Stefan; Broer, Dirk J.; Debije, Michael G.; Schenning, Albertus P. H. J.

    2016-07-01

    Nature provides much inspiration for the design of materials capable of motion upon exposure to external stimuli, and many examples of such active systems have been created in the laboratory. However, to achieve continuous motion driven by an unchanging, constant stimulus has proven extremely challenging. Here we describe a liquid crystalline polymer film doped with a visible light responsive fluorinated azobenzene capable of continuous chaotic oscillatory motion when exposed to ambient sunlight in air. The presence of simultaneous illumination by blue and green light is necessary for the oscillating behaviour to occur, suggesting that the dynamics of continuous forward and backward switching are causing the observed effect. Our work constitutes an important step towards the realization of autonomous, persistently self-propelling machines and self-cleaning surfaces powered by sunlight.

  13. A chaotic self-oscillating sunlight-driven polymer actuator.

    PubMed

    Kumar, Kamlesh; Knie, Christopher; Bléger, David; Peletier, Mark A; Friedrich, Heiner; Hecht, Stefan; Broer, Dirk J; Debije, Michael G; Schenning, Albertus P H J

    2016-01-01

    Nature provides much inspiration for the design of materials capable of motion upon exposure to external stimuli, and many examples of such active systems have been created in the laboratory. However, to achieve continuous motion driven by an unchanging, constant stimulus has proven extremely challenging. Here we describe a liquid crystalline polymer film doped with a visible light responsive fluorinated azobenzene capable of continuous chaotic oscillatory motion when exposed to ambient sunlight in air. The presence of simultaneous illumination by blue and green light is necessary for the oscillating behaviour to occur, suggesting that the dynamics of continuous forward and backward switching are causing the observed effect. Our work constitutes an important step towards the realization of autonomous, persistently self-propelling machines and self-cleaning surfaces powered by sunlight. PMID:27375235

  14. A chaotic self-oscillating sunlight-driven polymer actuator

    PubMed Central

    Kumar, Kamlesh; Knie, Christopher; Bléger, David; Peletier, Mark A.; Friedrich, Heiner; Hecht, Stefan; Broer, Dirk J.; Debije, Michael G.; Schenning, Albertus P. H. J.

    2016-01-01

    Nature provides much inspiration for the design of materials capable of motion upon exposure to external stimuli, and many examples of such active systems have been created in the laboratory. However, to achieve continuous motion driven by an unchanging, constant stimulus has proven extremely challenging. Here we describe a liquid crystalline polymer film doped with a visible light responsive fluorinated azobenzene capable of continuous chaotic oscillatory motion when exposed to ambient sunlight in air. The presence of simultaneous illumination by blue and green light is necessary for the oscillating behaviour to occur, suggesting that the dynamics of continuous forward and backward switching are causing the observed effect. Our work constitutes an important step towards the realization of autonomous, persistently self-propelling machines and self-cleaning surfaces powered by sunlight. PMID:27375235

  15. Estimation of sunlight penetration in the sea for remote sensing

    NASA Technical Reports Server (NTRS)

    Mccluney, W. R.

    1974-01-01

    There is a need for a simple theoretical approach to the calculation of sunlight penetration depths suitable for passive multispectral remote sensing of water resources. An earlier paper presented an approach which is readily adapted to this calculation and which provides reasonably good agreement with more accurate but time-consuming radiative transfer models. The needed modifications are described and the model is used to calculate the penetration of sunlight into clear ocean water at several wavelengths throughout the visible portion of the spectrum. Calculations for both clear and turbid water are carried out for the two visible channels of the multispectral scanner on NASA's ERTS-1 satellite. The effect of a reflective bottom on the upwelling light field is discussed. Measurement parameters needed for the passive remote determination of water depths are identified and the use of submerged reflective panels for surface truth measurements is discussed.

  16. Sunlight over Earth as seen by STS-29 crew

    NASA Technical Reports Server (NTRS)

    1989-01-01

    A 35mm camera was used to photograph sunlight over a cloud- covered Earth surface by STS-29 crewmembers onboard Discovery, Orbiter Vehicle (OV) 103. This photographic frame was among NASA's STS-29 photo release on Monday, March 20,1989. Discovery was launched on March 18,1989, with the crew of Michael L. Coats (Commander), John E. Blaha (Pilot), James P. Bagian (Mission Specialist), James F. Buchli (Mission Specialist), and Robert C. Springer (Mission Specialist).

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

    NASA Astrophysics Data System (ADS)

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

    2016-03-01

    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 F10.7 index, showing that increasing solar EUV flux changes not only the magnitude but also the morphology of the equivalent current system. The results are consistent with a recent study showing that Birkeland currents indirectly determine the equivalent current in darkness and that Hall currents dominate in sunlight. This has implication for the interpretation of ground magnetic field measurements and suggests that the magnetic disturbances at conjugate points will be asymmetrical when the solar illumination is different.

  18. Bactericidal Effect of Solar Water Disinfection under Real Sunlight Conditions▿

    PubMed Central

    Boyle, M.; Sichel, C.; Fernández-Ibáñez, P.; Arias-Quiroz, G. B.; Iriarte-Puña, M.; Mercado, A.; Ubomba-Jaswa, E.; McGuigan, K. G.

    2008-01-01

    Batch solar disinfection (SODIS) inactivation kinetics are reported for suspensions in water of Campylobacter jejuni, Yersinia enterocolitica, enteropathogenic Escherichia coli, Staphylococcus epidermidis, and endospores of Bacillus subtilis, exposed to strong natural sunlight in Spain and Bolivia. The exposure time required for complete inactivation (at least 4-log-unit reduction and below the limit of detection, 17 CFU/ml) under conditions of strong natural sunlight (maximum global irradiance, ∼1,050 W m−2 ± 10 W m−2) was as follows: C. jejuni, 20 min; S. epidermidis, 45 min; enteropathogenic E. coli, 90 min; Y. enterocolitica, 150 min. Following incomplete inactivation of B. subtilis endospores after the first day, reexposure of these samples on the following day found that 4% (standard error, 3%) of the endospores remained viable after a cumulative exposure time of 16 h of strong natural sunlight. SODIS is shown to be effective against the vegetative cells of a number of emerging waterborne pathogens; however, bacterial species which are spore forming may survive this intervention process. PMID:18359829

  19. Thermal infrared survey of Sunlight Basin, Park County, Wyoming

    SciTech Connect

    Vice, D.H.; Crowley, J.P.; Vice, M.A.

    1983-08-01

    Thermal infrared surveys were flown over the Sunlight mining region and Sulphur Camp area of the Sunlight Basin to substantiate whether reported fumaroles are indicative of contemporary geothermal activity in the area. Thermal infrared imagery shows areas of warm ground along and warm water discharge into Sunlight Creek and Sulphur Lake. Sulphur deposits are found on north- and south-facing hill slopes associated with a second warm ground anomaly adjacent to Gas Creek. Warming is also manifested in the thermal characteristics of vegetation, and several fumaroles are identifiable. Aeromagnetic data show a 200 gamma low at Sulphur Camp which cannot be explained topographically. Major northeast-trending lineaments provide potential conduits for thermal fluids from the magma plume in Yellowstone National Park, 50 km (30 mi) to the southwest. The floor of the Yellowstone caldera is topographically higher and could provide the necessary hydraulic head to move the fluids outward. Other geothermal resources may exhibit the same characteristics. This example suggests that geothermal resources may occur at considerable distances from a heat source.

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

    SciTech Connect

    Mann, M.K.; Spath, P.L.; Amos, W.A.

    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.

  1. Inactivation of Escherichia coli by Polychromatic Simulated Sunlight: Evidence for and Implications of a Fenton Mechanism Involving Iron, Hydrogen Peroxide, and Superoxide

    PubMed Central

    2014-01-01

    Sunlight inactivation of Escherichia coli has previously been shown to accelerate in the presence of oxygen, exogenously added hydrogen peroxide, and bioavailable forms of exogenously added iron. In this study, mutants unable to effectively scavenge hydrogen peroxide or superoxide were found to be more sensitive to polychromatic simulated sunlight (without UVB wavelengths) than wild-type cells, while wild-type cells grown under low-iron conditions were less sensitive than cells grown in the presence of abundant iron. Furthermore, prior exposure to simulated sunlight was found to sensitize cells to subsequent hydrogen peroxide exposure in the dark, but this effect was attenuated for cells grown with low iron. Mutants deficient in recombination DNA repair were sensitized to simulated sunlight (without UVB wavelengths), but growth in the presence of iron chelators reduced the degree of sensitization conferred by this mutation. These findings support the hypothesis that hydrogen peroxide, superoxide, and intracellular iron all participate in the photoinactivation of E. coli and further suggest that the inactivation rate of enteric bacteria in the environment may be strongly dependent on iron availability and growth conditions. PMID:24271171

  2. Inactivation of Escherichia coli by polychromatic simulated sunlight: evidence for and implications of a fenton mechanism involving iron, hydrogen peroxide, and superoxide.

    PubMed

    Fisher, Michael B; Nelson, Kara L

    2014-02-01

    Sunlight inactivation of Escherichia coli has previously been shown to accelerate in the presence of oxygen, exogenously added hydrogen peroxide, and bioavailable forms of exogenously added iron. In this study, mutants unable to effectively scavenge hydrogen peroxide or superoxide were found to be more sensitive to polychromatic simulated sunlight (without UVB wavelengths) than wild-type cells, while wild-type cells grown under low-iron conditions were less sensitive than cells grown in the presence of abundant iron. Furthermore, prior exposure to simulated sunlight was found to sensitize cells to subsequent hydrogen peroxide exposure in the dark, but this effect was attenuated for cells grown with low iron. Mutants deficient in recombination DNA repair were sensitized to simulated sunlight (without UVB wavelengths), but growth in the presence of iron chelators reduced the degree of sensitization conferred by this mutation. These findings support the hypothesis that hydrogen peroxide, superoxide, and intracellular iron all participate in the photoinactivation of E. coli and further suggest that the inactivation rate of enteric bacteria in the environment may be strongly dependent on iron availability and growth conditions. PMID:24271171

  3. Morphology-controlled electrodeposition of Cu{sub 2}O microcrystalline particle films for application in photocatalysis under sunlight

    SciTech Connect

    Wu, Guodong; Zhai, Wei; Sun, Fengqiang; Chen, Wei; Pan, Zizhao; Li, Weishan

    2012-12-15

    Graphical abstract: Display Omitted Highlights: ► PEG was used to electro-deposit Cu{sub 2}O microcrystalline particle films. ► Morphologies of Cu{sub 2}O microcrystals could be controlled by the amount of PEG. ► The films showed regularly varied photocatalytic activities under sunlight. ► The films could be recycled and showed stable activities. -- Abstract: Morphology-controlled Cu{sub 2}O microcrystalline particle films had been successfully electrodeposited on tin-doped indium oxide glass substrates in CuSO{sub 4} solutions containing different amounts of polyethylene glycol (PEG) additives. With an increase of PEG, microcrystals gradually changed from irregular shapes to cubes, octahedrons, and spherical shapes. Sizes increasingly became smaller with an increase of PEG under the same deposition time. These films had been first used as recyclable photocatalysts and showed excellent and photocatalytic activities in photodegradation of methylene blue (MB) under sunlight. Activities were regularly varied relative to the morphologies of films controlled by the amount of PEG and could be further enhanced by adding a little amount of hydrogen peroxide in the MB solution. The method for controllable preparation of Cu{sub 2}O microcrystals with photocatalytic activities was simple and inexpensive. The as-prepared particle films could also be used in photodegradation of many other pollutants under sunlight.

  4. Dimmable sunlight-like organic light emitting diodes with ultra-high color rendering index

    NASA Astrophysics Data System (ADS)

    Wu, Jin-Han; Chi, Chien-An; Chiang, Chang-Lin; Chen, Guan-Yu; Lin, Yi-Ping; Chen, Cheng-Chang; Ho, Shu-Yi; Chen, Shih-Pu; Li, Jung-Yu

    2016-05-01

    We propose novel dimmable sunlight-like white organic light-emitting diodes that were fabricated using three luminophores to form an emitting spectrum similar to black body radiation at 2250 K with ultra-high color rendering index (CRI) value of 91, which nearly remained the constant at various luminance values ranging from 100 to more than 2500 cd/m2 at Commission Internationale de l'Eclairage chromaticity coordinates of (0.51, 0.41). Introducing charge modification layers suppressed the energy transfer between the emitting material layers and increased the probability of carrier recombination. Moreover, we reveal that covering long-wavelength ranges played a vital role in achieving high CRI values; the CRI values of a spectrum artificially shifted toward a long-wavelength direction (from 610 to 620 nm) remained constant, whereas those of a spectrum shifted toward a short-wavelength direction (from 610 to 600 nm) dropped to 79.

  5. Space Satellite Dynamics with Applications to Sunlight Pressure Attitude Control. Ph.D. Thesis

    NASA Technical Reports Server (NTRS)

    Stuck, B. W.

    1972-01-01

    A research program into three aspects of space satellite dynamics was carried out. First, a four-dimensional space-time formulation of Newtonian mechanics is developed. This theory allows a new physical interpretation of the conservation theorems of mechanics first derived rigorously by Noether. Second, a new concept for estimating the three angles which specify the orientation in space of a rigid body is presented. Two separate methods for implementing this concept are discussed, one based on direction cosines, the other on quaternions. Two examples are discussed: constant orientation in space, and constant rate of change of the three angles with time. Third, two synchronous equatorial orbit communication satellite designs which use sunlight pressure to control their attitude are analyzed. Each design is equipped with large reflecting surfaces, called solar sails, which can be canted in different directions to generate torques to correct pointing errors.

  6. Influence of coagulation factor x on in vitro and in vivo gene delivery by adenovirus (Ad) 5, Ad35, and chimeric Ad5/Ad35 vectors.

    PubMed

    Greig, Jenny A; Buckley, Suzanne Mk; Waddington, Simon N; Parker, Alan L; Bhella, David; Pink, Rebecca; Rahim, Ahad A; Morita, Takashi; Nicklin, Stuart A; McVey, John H; Baker, Andrew H

    2009-10-01

    The binding of coagulation factor X (FX) to the hexon of adenovirus (Ad) 5 is pivotal for hepatocyte transduction. However, vectors based on Ad35, a subspecies B Ad, are in development for cancer gene therapy, as Ad35 utilizes CD46 (which is upregulated in many cancers) for transduction. We investigated whether interaction of Ad35 with FX influenced vector tropism using Ad5, Ad35, and Ad5/Ad35 chimeras: Ad5/fiber(f)35, Ad5/penton(p)35/f35, and Ad35/f5. Surface plasmon resonance (SPR) revealed that Ad35 and Ad35/f5 bound FX with approximately tenfold lower affinities than Ad5 hexon-containing viruses, and electron cryomicroscopy (cryo-EM) demonstrated a direct Ad35 hexon:FX interaction. The presence of physiological levels of FX significantly inhibited transduction of vectors containing Ad35 fibers (Ad5/f35, Ad5/p35/f35, and Ad35) in CD46-positive cells. Vectors were intravenously administered to CD46 transgenic mice in the presence and absence of FX-binding protein (X-bp), resulting in reduced liver accumulation for all vectors. Moreover, Ad5/f35 and Ad5/p35/f35 efficiently accumulated in the lung, whereas Ad5 demonstrated poor lung targeting. Additionally, X-bp significantly reduced lung genome accumulation for Ad5/f35 and Ad5/p35/f35, whereas Ad35 was significantly enhanced. In summary, vectors based on the full Ad35 serotype will be useful vectors for selective gene transfer via CD46 due to a weaker FX interaction compared to Ad5. PMID:19603000

  7. Worldsheet scattering in AdS3/CFT2

    NASA Astrophysics Data System (ADS)

    Sundin, Per; Wulff, Linus

    2013-07-01

    We confront the recently proposed exact S-matrices for AdS 3/ CFT 2 with direct worldsheet calculations. Utilizing the BMN and Near Flat Space (NFS) expansions for strings on AdS 3 × S 3 × S 3 × S 1 and AdS 3 × S 3 × T 4 we compute both tree-level and one-loop scattering amplitudes. Up to some minor issues we find nice agreement in the tree-level sector. At the one-loop level however we find that certain non-zero tree-level processes, which are not visible in the exact solution, contribute, via the optical theorem, and give an apparent mismatch for certain amplitudes. Furthermore we find that a proposed one-loop modification of the dressing phase correctly reproduces the worldsheet calculation while the standard Hernandez-Lopez phase does not. We also compute several massless to massless processes.

  8. Direct and correlated responses to selection in two lines of rabbits selected for feed efficiency under ad libitum and restricted feeding: II. Carcass and meat quality.

    PubMed

    Molette, C; Gilbert, H; Larzul, C; Balmisse, E; Ruesche, J; Manse, H; Tircazes, A; Theau-Clément, M; Joly, T; Gidenne, T; Garreau, H; Drouilhet, L

    2016-01-01

    To get insights into selection criteria for feed efficiency, 2 rabbit lines have been created: the ConsoResidual line was selected for residual feed intake (RFI) with ad libitum feeding and the ADGrestrict line was selected for ADG under restricted feeding. The aim of the present study was to evaluate the impact on carcass and meat quality of the genetic selections. This comparison was performed using 2 different feeding strategies corresponding to the selection design. Carcass and meat quality traits were recorded for the 3 lines (ConsoResidual, ADGrestrict, and an unselected control [generation 0 {G0}]) in the 2 feeding systems (ad libitum and restricted) for 163 animals. Concerning the line effect, the BW at 63 d old was higher for the ADGrestrict line compared with the G0 and ConsoResidual lines ( < 0.0001). There was no line effect on the gastrointestinal tract. The rabbits did not exhibit a different carcass yield but showed different carcass traits. Indeed, the ConsoResidual rabbits had a higher hind leg yield ( < 0.0001) but no difference in the meat-to-bone ratio of the hind leg. On the contrary, the ADGrestrict line had a higher proportion of forelegs plus thoracic cage ( = 0.03). We also found lower perirenal ( < 0.0001) and scapular fat yields ( < 0.0001) in ConsoResidual rabbits. The ADGrestrict line had an intermediate perirenal fat yield compared with the other 2 lines. The G0 line always exhibited higher fat yields. Concerning meat quality, the ConsoResidual rabbits showed a lower ultimate pH ( < 0.0001) and higher water loss (drip and cooking loss; < 0.002) compared with the G0 and ADGrestrict rabbits. The feeding level had a strong effect on the gastrointestinal tract ( = 0.0004) and the carcass yield ( = 0.001). The latter was decreased in restricted rabbits. The effects of feeding strategy on meat quality were detrimental in the case of restricted feeding. Even if the ultimate pH was slightly higher in restricted rabbits ( = 0.0002), the carcass

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

    PubMed

    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 < 0.01). The serum values of total alkaline phosphatase and intact parathyroid hormone were significantly decreased and that of 25-hydroxyvitamin D was significantly increased 12 months after starting 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. PMID:27227999

  10. Can Skin Exposure to Sunlight Prevent Liver Inflammation?

    PubMed Central

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

    2015-01-01

    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. PMID:25951129

  11. Ocean color remote sensing using polarization properties of reflected sunlight

    NASA Technical Reports Server (NTRS)

    Frouin, R.; Pouliquen, E.; Breon, F.-M.

    1994-01-01

    The effects of the atmosphere and surface on sunlight backscattered to space by the ocean may be substantially reduced by using the unpolarized component of reflectance instead of total reflectance. At 450 nm, a wavelength of interest in ocean color remote sensing, and for typical conditions, 45% of the unpolarized reflectance may originate from the water body instead of 20% of the total reflectance, which represents a gain of a factor 2.2 in useful signal for water composition retrieval. The best viewing geometries are adjacent to the glitter region; they correspond to scattering angles around 100 deg, but they may change slightly depending on the polarization characteristics of the aerosols. As aerosol optical thickness increases, the atmosphere becomes less efficient at polarizing sunlight, and the enhancement of the water body contribution to unpolarized reflectance is reduced. Since the perturbing effects are smaller on unpolarized reflectance, at least for some viewing geometries, they may be more easily corrected, leading to a more accurate water-leaving signal and, therefore, more accurate estimates of phytoplankton pigment concentration.

  12. Commentary on: Saper CB, Loewy AD, Swanson LW, Cowan WM. (1976) Direct hypothalamo-autonomic connections. Brain Research 117:305-312.

    PubMed

    Saper, Clifford B; Loewy, Arthur D; Swanson, Larry W

    2016-08-15

    The 1970s saw the introduction of new technologies for tracing axons both anterogradely and retrogradely. These methods allowed us to visualize fine, unmyelinated pathways for the first time, such as the hypothalamic pathways that control the autonomic nervous system. As a result, we were able to identify the paraventricular nucleus and lateral hypothalamus as the key sites that provide direct inputs to the autonomic preganglionic neurons in the medulla and spinal cord. These findings revolutionized our understanding of hypothalamic control of the autonomic nervous system. PMID:26944298

  13. SiC7 siligraphene: a novel donor material with extraordinary sunlight absorption.

    PubMed

    Dong, Huilong; Zhou, Liujiang; Frauenheim, Thomas; Hou, Tingjun; Lee, Shuit-Tong; Li, Youyong

    2016-04-01

    The SiC7 siligraphene (g-SiC7) is a novel 2D nanomaterial with a graphene-like structure. Based on theoretical calculations, we have systematically investigated the structure, stability, electronic and optical properties of g-SiC7 siligraphene. The calculated results reveal that g-SiC7 siligraphene is a semiconductor with a direct band gap of 1.13 eV, which can be easily tuned by applying biaxial strain or a perpendicular electric field. Such a g-SiC7 siligraphene shows superior sunlight optical absorbance and is better than g-SiC2 siligraphene and single-layer black phosphorus (phosphorene) in near infrared and visible photon ranges, thus holding great potential for photovoltaics applications as a light donor material. PMID:26980670

  14. Penetration of sunlight into a canopy - Explicit models based on vertical and horizontal leaf projections

    NASA Technical Reports Server (NTRS)

    Otterman, J.; Brakke, T.

    1986-01-01

    The projections of leaf areas onto a horizontal plane and onto a vertical plane are examined for their utility in characterizing canopies for sunlight penetration (direct beam only) models. These projections exactly specify the penetration if the projections on the principal plane of the normals to the top surfaces of the leaves are in the same quadrant as the sun. Inferring the total leaf area from these projections (and therefore the penetration as a function of the total leaf area) is possible only with a large uncertainty (up to + or - 32 percent) because the projections are a specific measure of the total leaf area only if the leaf angle distribution is known. It is expected that this uncertainty could be reduced to more acceptable levels by making an approximate assessment of whether the zenith angle distribution is that of an extremophile canopy.

  15. Sunlight mediated inactivation mechanisms of Enterococcus faecalis and Escherichia coli in clear water versus waste stabilization pond water.

    PubMed

    Kadir, Khalid; Nelson, Kara L

    2014-03-01

    Escherichia coli and enterococci have been previously reported to differ in the mechanisms and conditions that affect their sunlight-mediated inactivation in waste stabilization ponds. This study was undertaken to further characterize these mechanisms, using simulated sunlight and single strains of laboratory-grown E. coli and Enterococcus faecalis, with a focus on characterizing the contribution of exogenous reactive oxygen species to the inactivation process. We found that direct damage by UVB light (280-320 nm) was not a significant inactivation mechanism for either organism. E. coli inactivation was strongly dependent on dissolved oxygen concentrations and the presence of UVB wavelengths but E. coli were not susceptible to inactivation by exogenous sensitizers present in waste stabilization pond water. In contrast, E. faecalis inactivation in pond water occurred primarily through exogenous mechanisms, with strong evidence that singlet oxygen is an important transient reactive species. The exogenous mechanism could utilize wavelengths into the visible spectrum and sensitizers were mainly colloidal, distributed between 0.2 and ∼1 μm in size. Singlet oxygen is likely an important endogenous species in both E. faecalis and E. coli inactivation due to sunlight. Although the two organisms had similar inactivation rates in buffered, clear water, the inactivation rate of E. faecalis was 7 times greater than that of E. coli in air-saturated pond water at circumneutral pH due to its susceptibility to exogenous sensitizers and longer wavelengths. PMID:24188579

  16. SiC7 siligraphene: a novel donor material with extraordinary sunlight absorption

    NASA Astrophysics Data System (ADS)

    Dong, Huilong; Zhou, Liujiang; Frauenheim, Thomas; Hou, Tingjun; Lee, Shuit-Tong; Li, Youyong

    2016-03-01

    The SiC7 siligraphene (g-SiC7) is a novel 2D nanomaterial with a graphene-like structure. Based on theoretical calculations, we have systematically investigated the structure, stability, electronic and optical properties of g-SiC7 siligraphene. The calculated results reveal that g-SiC7 siligraphene is a semiconductor with a direct band gap of 1.13 eV, which can be easily tuned by applying biaxial strain or a perpendicular electric field. Such a g-SiC7 siligraphene shows superior sunlight optical absorbance and is better than g-SiC2 siligraphene and single-layer black phosphorus (phosphorene) in near infrared and visible photon ranges, thus holding great potential for photovoltaics applications as a light donor material.The SiC7 siligraphene (g-SiC7) is a novel 2D nanomaterial with a graphene-like structure. Based on theoretical calculations, we have systematically investigated the structure, stability, electronic and optical properties of g-SiC7 siligraphene. The calculated results reveal that g-SiC7 siligraphene is a semiconductor with a direct band gap of 1.13 eV, which can be easily tuned by applying biaxial strain or a perpendicular electric field. Such a g-SiC7 siligraphene shows superior sunlight optical absorbance and is better than g-SiC2 siligraphene and single-layer black phosphorus (phosphorene) in near infrared and visible photon ranges, thus holding great potential for photovoltaics applications as a light donor material. Electronic supplementary information (ESI) available: Computational details on stability and optical absorbance calculations, the phonon dispersion of g-SiC7 siligraphene and snapshots of FPMD simulation. See DOI: 10.1039/c6nr00046k

  17. Effects of added chelated trace minerals, organic selenium, yeast culture, direct-fed microbials, and Yucca schidigera extract in horses. Part I: Blood nutrient concentration and digestibility.

    PubMed

    Gordon, M E; Edwards, M S; Sweeney, C R; Jerina, M L

    2013-08-01

    The objective of this study was to test the hypothesis that feed additives such as chelated minerals, organic Se, yeast culture, direct-fed microbials, and Yucca schidigera extract would improve nutrient digestibility when included in an equine diet. Horses (Quarter Horse geldings 4.5 to 16 yr of age; mean BW 522 kg ± 46 kg) were acclimated to 100% pelleted diets formulated with (ADD) and without (CTRL) commercially available sources of the aforementioned additives followed by a 14-d collection period of feces and urine. Chelated sources of Cu, Zn, Mn and Co were utilized versus sulfated forms, at a 100% replacement rate. No significant differences among apparent the digestibility of DM, ADF, or NDF (P= 0.665, P = 0.866, P = 0.747, respectively) were detected between dietary treatments. Likewise, no differences in apparent digestibility of Cu (P = 0.724), Zn (P = 0.256), Mn (P = 0.888), Co (P = 0.71), or Se (P = 0.588) were observed. No differences were observed in serum Cu, Mn, or Co concentrations between ADD and CTRL at acclimation or collection time points (P > 0.05). While no difference in serum Zn concentrations were observed between ADD and CTRL groups at acclimation (P > 0.05), they were statistically higher at the collection time period for horses consuming CTRL (P < 0.0001). Whole blood Se concentration was greater in the CTRL group versus the ADD group both at acclimation (P = 0.041) and collection (P = 0.005) time periods. In reference to time, serum Cu concentrations increased (P = 0.012) for animals consuming CTRL, but not ADD (P > 0.05). Serum Zn concentrations of horses consuming both ADD (P = 0.021) and CTRL (P < 0.0001) increased over time from acclimation to collection time points. No time differences (P > 0.05) were observed in serum Mn concentrations. Serum Co concentrations increased over time in horses consuming both ADD (P = 0.001) and CTRL (P = 0.021). From acclimation to collection, whole blood Se concentration increased for horses

  18. Entanglement temperature and perturbed AdS3 geometry

    NASA Astrophysics Data System (ADS)

    Levine, G. C.; Caravan, B.

    2016-06-01

    Generalizing the first law of thermodynamics, the increase in entropy density δ S (x ) of a conformal field theory (CFT) is proportional to the increase in energy density, δ E (x ) , of a subsystem divided by a spatially dependent entanglement temperature, TE(x ) , a fixed parameter determined by the geometry of the subsystem, crossing over to thermodynamic temperature at high temperatures. In this paper we derive a generalization of the thermodynamic Clausius relation, showing that deformations of the CFT by marginal operators are associated with spatial temperature variations, δ TE(x ) , and spatial energy correlations play the role of specific heat. Using AdS/CFT duality we develop a relationship between a perturbation in the local entanglement temperature of the CFT and the perturbation of the bulk AdS metric. In two dimensions, we demonstrate a method through which direct diagonalizations of the boundary quantum theory may be used to construct geometric perturbations of AdS3 .

  19. Sunlight at Southall Green. Dr. Ingen Housz discovers photosynthesis.

    PubMed

    Norman; Beale, E

    2001-01-01

    In the following fictitious conversation, Dr. Jan Ingen Housz (1730-1799), the Dutch physician and natural philosopher, describes to William Temple Franklin (1760-1823), the grandson of Benjamin Franklin, how in 1779 he discovered the paramount role of sunlight in what we now call photosynthesis (Wiesner 1905; Van der Pas 1981; Reed 1949; Beale and Beale 1999). The two men, together with the English law reformer Samuel Romilly, were dinner guests of the First Marquis of Lansdowne at Lansdowne House on Wednesday 2 February 1791 (Bowood House Archives 1791). As far as possible we use their own recorded words and phrases, employing surviving manuscripts as a lexicon. Additional biographical and geographical details are provided in an Appendix, and all sources are listed in the References. PMID:11482003

  20. Circadian clocks optimally adapt to sunlight for reliable synchronization

    PubMed Central

    Hasegawa, Yoshihiko; Arita, Masanori

    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 synchronize internal time with periodic stimuli such as sunlight, and regularity to oscillate with a precise period. These two aspects do not easily coexist, because better entrainability favours higher sensitivity which may sacrifice regularity. To investigate conditions for satisfying the two properties, we analytically calculated the optimal phase–response curve with a variational method. Our results indicate an existence of a dead zone, i.e. a time period during which input stimuli neither advance nor delay the clock. A dead zone appears only when input stimuli obey the time course of actual solar radiation, but a simple sine curve cannot yield a dead zone. Our calculation demonstrates that every circadian clock with a dead zone is optimally adapted to the daylight cycle. PMID:24352677

  1. Sunlight absorption by aerosols in Jupiter's upper atmosphere

    NASA Technical Reports Server (NTRS)

    West, R. A.

    1981-01-01

    The amount of sunlight deposited in the Jovian upper atmosphere is estimated from reflectivity measurements at 2400 A by the Voyager 2 Photopolarimeter experiment and at visible and near-IR wavelengths observed by Pioneer 10 and ground-based instruments. Zero to about one percent of the incident energy is absorbed at altitudes above the 100 mbar level in models with mean values for haze optical depth and single scattering albedo. Several percent of the incident energy could be absorbed, if limiting values are used, and if an additional absorbing layer is incorporated below the high altitude haze in Pioneer models. Maximum absorption occurs at the edge of the polar regions near + or - 65 deg latitude. Most of the absorbed energy is derived from visible and near-IR radiation rather than UV radiation.

  2. Circular polarization of sunlight reflected by planetary atmospheres

    NASA Technical Reports Server (NTRS)

    Kawata, Y.

    1978-01-01

    Multiple scattering calculations are performed in order to investigate the nature of the circular polarization of sunlight reflected by planetary atmospheres. Contour diagrams as a function of size parameter and phase angle are made for the integrated light from a spherical but locally plane-parallel atmosphere of spherical particles. To investigate the origin of the circular polarization, results are also computed for second-order scattering and for a simpler semiquantitative model of scattering by two particles. Observations of the circular polarization of the planets are presently too meager for accurate deduction of cloud particle properties. However, certain very broad constraints can be placed on the properties of the dominant cloud particles on Jupiter and Saturn. The cloud particle size and refractive index deduced for the Jupiter clouds by Loskutov, Morozhenko, and Yanovitskii from analyses of the linear polarization are not consistent with the circular polarization. The few available circular polarization observations of Venus are also examined.

  3. Polarised black holes in AdS

    NASA Astrophysics Data System (ADS)

    Costa, Miguel S.; Greenspan, Lauren; Oliveira, Miguel; Penedones, João; Santos, Jorge E.

    2016-06-01

    We consider solutions in Einstein-Maxwell theory with a negative cosmological constant that asymptote to global AdS 4 with conformal boundary {S}2× {{{R}}}t. At the sphere at infinity we turn on a space-dependent electrostatic potential, which does not destroy the asymptotic AdS behaviour. For simplicity we focus on the case of a dipolar electrostatic potential. We find two new geometries: (i) an AdS soliton that includes the full backreaction of the electric field on the AdS geometry; (ii) a polarised neutral black hole that is deformed by the electric field, accumulating opposite charges in each hemisphere. For both geometries we study boundary data such as the charge density and the stress tensor. For the black hole we also study the horizon charge density and area, and further verify a Smarr formula. Then we consider this system at finite temperature and compute the Gibbs free energy for both AdS soliton and black hole phases. The corresponding phase diagram generalizes the Hawking-Page phase transition. The AdS soliton dominates the low temperature phase and the black hole the high temperature phase, with a critical temperature that decreases as the external electric field increases. Finally, we consider the simple case of a free charged scalar field on {S}2× {{{R}}}t with conformal coupling. For a field in the SU(N ) adjoint representation we compare the phase diagram with the above gravitational system.

  4. Persistence of Bacteroides ovatus under simulated sunlight irradiation

    PubMed Central

    2014-01-01

    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. PMID:24993443

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

    PubMed Central

    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

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

    PubMed

    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. PMID:27049790

  7. Effects of added chelated trace minerals, organic selenium, yeast culture, direct-fed microbials, and Yucca schidigera extract in horses: II. Nutrient excretion and potential environmental impact.

    PubMed

    Gordon, M E; Edwards, M S; Sweeney, C R; Jerina, M L

    2013-08-01

    The objective of this study was to test the hypothesis that an equine diet formulated with chelated trace minerals, organic selenium, yeast culture, direct-fed microbials (DFM) and Yucca schidigera extract would decrease excretion of nutrients that have potential for environmental impact. Horses were acclimated to 100% pelleted diets formulated with (ADD) and without (CTRL) the aforementioned additives. Chelated sources of Cu, Zn, Mn, and Co were included in the ADD diet at a 100% replacement rate of sulfate forms used in the CTRL diet. Additionally, the ADD diet included organic selenium yeast, DFM, and Yucca schidigera extract. Ten horses were fed the 2 experimental diets during two 42-d periods in a crossover design. Total fecal and urine collection occurred during the last 14 d of each period. Results indicate no significant differences between Cu, Zn, Mn, and Co concentrations excreted via urine (P > 0.05) due to dietary treatment. There was no difference between fecal Cu and Mn concentrations (P > 0.05) based on diet consumed. Mean fecal Zn and Co concentrations excreted by horses consuming ADD were greater than CTRL (P < 0.003). Differences due to diet were found for selenium fecal (P < 0.0001) and urine (P < 0.0001) excretions, with decreased concentrations found for horses consuming organic selenium yeast (ADD). In contrast, fecal K (%) was greater (P = 0.0421) for horses consuming ADD, whereas concentrations of fecal solids, total N, ammonia N, P, total ammonia, and fecal output did not differ between dietary treatments (P > 0.05). In feces stockpiled to simulate a crude composting method, no differences (P > 0.05) due to diet were detected for particle size, temperature, moisture, OM, total N, P, phosphate, K, moisture, potash, or ammonia N (P > 0.05). Although no difference (P = 0.2737) in feces stockpile temperature due to diet was found, temperature differences over time were documented (P < 0.0001). In conclusion, the addition of certain chelated

  8. How to protect the Earth from Global warming by means of Sunlight Shield Equipments

    NASA Astrophysics Data System (ADS)

    Murakami, H.

    2010-09-01

    The Earth is getting warmer because excess carbon dioxide of the Earth's atmosphere. Many studies are proceeding in the world in order to prevent global warming. Three methods are studied: (1) How to reduce carbon dioxide of the Earth's atmosphere. For example, more trees will be planted and carbon dioxide is changed to oxygen and carbon. (2) How to reduce carbon dioxide emission that human activity makes. (3) How to protect the Earth from global warming. The first or the second method has been studied, and they do not immediately protect the Earth from global warming. On the other hand the third method has an immediate effect. Sunlight shield effects of a cloud or tiny sulfur in the air have been studied. The author has proposed a sunlight shield equipment which is composed of a flat balloon. Balloon's surface has a mirror function. The sunlight shield equipment is set at the stratosphere and its surface reflects sunlight to the space. It is different temperature between daytime and night time, because the earth is heated by the sun during only daytime. Temperature of the Earth could be controlled by controlling an amount of a sunlight power which the earth receives from the sun. In other word, when many sunlight shield equipments are set and operated at the stratosphere, and an amount of sunlight, which the earth receives from the sun, could be controlled. For example, when an amount of the sunlight power, which the earth receives, decreases one percent, a mean value of the earth temperature deceases about one centigrade. In order to decrease one percent of a sunlight power which the earth receives, it is required that many sunlight shield equipments are distributively set and operated, and the gross area of many sunlight shield equipments is equal to 5,060,000 km squares. When a size of a sunlight shield equipment is equal to 5 km squares, about one million of sunlight shield equipments are necessary, and a large scale of cost is required. Therefore, an

  9. Sunlight creates oxygenated species in water-soluble fractions of Deepwater Horizon oil.

    PubMed

    Ray, Phoebe Z; Chen, Huan; Podgorski, David C; McKenna, Amy M; Tarr, Matthew A

    2014-09-15

    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 (O5), while the most abundant acids in the dark samples contain two oxygen atoms per molecule (O2). Higher-order oxygen classes (O5-O9) 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 (N1) concurrent with an increased abundance of N1Ox classes after irradiation. The predominance of higher-order oxygen classes indicates that multiple photochemical pathways exist that result in oxidation of petroleum compounds. PMID:25222929

  10. Impact of sunlight on the age of onset of bipolar disorder

    PubMed Central

    Bauer, Michael; Glenn, Tasha; Alda, Martin; Andreassen, Ole A; Ardau, Raffaella; Bellivier, Frank; Berk, Michael; Bjella, Thomas D; Bossini, Letizia; Zompo, Maria Del; Dodd, Seetal; Fagiolini, Andrea; Frye, Mark A; Gonzalez-Pinto, Ana; Henry, Chantal; Kapczinski, Flávio; Kliwicki, Sebastian; König, Barbara; Kunz, Mauricio; Lafer, Beny; Lopez-Jaramillo, Carlos; Manchia, Mirko; Marsh, Wendy; Martinez-Cengotitabengoa, Mónica; Melle, Ingrid; Morken, Gunnar; Munoz, Rodrigo; Nery, Fabiano G; O’Donovan, Claire; Pfennig, Andrea; Quiroz, Danilo; Rasgon, Natalie; Reif, Andreas; Rybakowski, Janusz; Sagduyu, Kemal; Simhandl, Christian; Torrent, Carla; Vieta, Eduard; Zetin, Mark; Whybrow, Peter C

    2012-01-01

    Objective Although bipolar disorder has high heritability, the onset occurs during several decades of life, suggesting that social and environmental factors may have considerable influence on disease onset. This study examined the association between the age of onset and sunlight at the location of onset. Method Data were obtained from 2414 patients with a diagnosis of bipolar I disorder, according to DSM-IV criteria. Data were collected at 24 sites in 13 countries spanning latitudes 6.3 to 63.4 degrees from the equator, including data from both hemispheres. The age of onset and location of onset were obtained retrospectively, from patient records and/or direct interviews. Solar insolation data, or the amount of electromagnetic energy striking the surface of the earth, were obtained from the NASA Surface Meteorology and Solar Energy (SSE) database for each location of onset. Results The larger the maximum monthly increase in solar insolation at the location of onset, the younger the age of onset (coefficient= −4.724, 95% CI: −8.124 to −1.323, p = 0.006), controlling for each country’s median age. The maximum monthly increase in solar insolation occurred in springtime. No relationships were found between the age of onset and latitude, yearly total solar insolation, and the maximum monthly decrease in solar insolation. The largest maximum monthly increases in solar insolation occurred in diverse environments, including Norway, arid areas in California, and Chile. Conclusion The large maximum monthly increase in sunlight in springtime may have an important influence on the onset of bipolar disorder. PMID:22612720

  11. UV and sunlight driven photoligation of quantum dots: understanding the photochemical transformation of the ligands.

    PubMed

    Aldeek, Fadi; Hawkins, Dana; Palomo, Valle; Safi, Malak; Palui, Goutam; Dawson, Philip E; Alabugin, Igor; Mattoussi, Hedi

    2015-02-25

    We have recently reported that photoinduced ligation of ZnS-overcoated quantum dots (QDs) offers a promising strategy to promote the phase transfer of these materials to polar and aqueous media using multidentate lipoic acid (LA)-modified ligands. In this study we investigate the importance of the underlying parameters that control this process, in particular, whether or not photoexcited QDs play a direct role in the photoinduced ligation. We find that irradiation of the ligand alone prior to mixing with hydrophobic QDs is sufficient to promote ligand exchange. Furthermore, photoligation onto QDs can also be carried out simply by using sunlight. Combining the use of Ellman's test with matrix-assisted laser desorption/ionization and electrospray ionization mass spectrometry, we probe the nature of the photochemical transformation of the ligands. We find that irradiation (using either a UV photoreactor or sunlight) alters the nature of the disulfide groups in the lipoic acid, yielding a different product mixture than what is observed for chemically reduced ligands. Irradiation of the ligand in solution generates a mixture of monomeric and oligomeric compounds. Ligation onto the QDs selectively favors oligomers, presumably due to their higher coordination onto the metal-rich QD surfaces. We also show that photoligation using mixed ligands allows the preparation of reactive nanocrystals. The resulting QDs are coupled to proteins and peptides and tested for cellular staining. This optically controlled ligation of QDs combined with the availability of a variety of multidentate and multifunctional LA-modified ligands open new opportunities for developing fluorescent platforms with great promises for use in imaging and sensor design. PMID:25612193

  12. Analyses and experiments of background sunlight's effects on laser detection system

    NASA Astrophysics Data System (ADS)

    Guo, Hao; Yin, Rui-guang; Ma, Na; Liang, Wei-wei; Li, Bo

    2015-10-01

    Background sunlight effect the technical performance of laser detection system significantly. Analyses and experiments were done to find the degree and regularity of effects of background sunlight on laser detection system. At first, we established the theoretical model of laser detection probability curve. We emulated and analysed the effects on probability curve under different sunlight intensity by the model. Moreover, we got the variation regularity of parameter in probability curve. Secondly, we proposed a prediction method of probability curve, which deduced the detecting parameter from measured data. The method can not only get the probability curve in arbitrary background sunlight by a measured probability curve in typical background sunlight, but also calculate the sensitivity of laser detection systems by probability curve at the specified probability. Thirdly, we measured the probability curves under three types of background sunlight. The illumination conditions in experiments included fine, overcast and night. These three curves can be used as reference to deduce other curves. Using model, method, and measured data mentioned above, we finally finished the analyses and appraisal of the effects of background sunlight on typical laser detection system. The research findings can provide the theoretical reference and technical support for adaptability evaluation of typical laser detection systems in different background sunlight.

  13. Investigation of sunlight-induced deterioration of aroma of pummelo (Citrus maxima) essential oil.

    PubMed

    Sun, Hao; Ni, Hui; Yang, Yuanfan; Wu, Ling; Cai, Hui-nong; Xiao, An-feng; Chen, Feng

    2014-12-10

    Deterioration of aromas of pummelo essential oil (EO) induced by sunlight was compared to those induced by heat and oxygen exposure using the techniques of sensory evaluation and GC-MS analysis. The sunlight-exposed EO was found to possess an oily off-flavor odor, which was significantly different from its counterparts induced by oxygen and heat. The strong oily note of the sunlight-exposed EO was attributed to the existence of linalool oxides and limonene oxides, as well as the lack of neral and geranial, for which UV sunlight was revealed to be the critical contributor causing the chemical reactions for the aroma changes. The results demonstrated that UV sunlight could significantly affect the aroma of the pummelo EO, providing valuable information that will benefit the production and storage of EO-based aromatic products. PMID:25438994

  14. High spacecraft potentials on ISEE-1 in sunlight

    NASA Technical Reports Server (NTRS)

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

    1987-01-01

    Data from 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 the presence of differential charging seem unlikely, if these precautions were effective. Modeling of the 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

    NASA Astrophysics Data System (ADS)

    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. Evaluation of window-tinting films for sunlight phototherapy.

    PubMed

    Vreman, Hendrik J; Slusher, Tina M; Wong, Ronald J; Schulz, Stephanie; Olusanya, Bolajoko O; Stevenson, David K

    2013-12-01

    We evaluated nine semi-transparent plastic window-tinting films for their ability to block ultraviolet A (UVA) and infrared (IR) radiation and transmit therapeutic blue light (400-520 nm) for treating jaundiced newborns. For indoor testing, three light sources (TL/52 special blue fluorescent, Black Light UVA and IR heat lamps) were positioned above each film and measured successively using a thermocouple thermometer, UVA radiometer and blue light irradiance meter, placed below each film. For outdoor testing, the same setup was used with the sun at zenith and a cloudless sky. Compared with unfiltered radiation, blue light transmission through films ranged from 24 to 83%, UVA transmission was 0.1-7.1% and reductions in IR heat were 6-12°C and 5-10°C for heat lamp and sun, respectively. The data suggest that most of the relatively low-cost window-tinting films tested can effectively reduce sunlight UV and IR and offer a range of significant attenuations of therapeutic blue light. PMID:23880667

  17. Sunlight-Driven, Water-Mediated Generation of Prebiotic Complexity

    NASA Astrophysics Data System (ADS)

    Rapf, R.; Griffith, E. C.; Perkins, R. J.; Vaida, V.

    2014-12-01

    Formation of chemically complex biomolecules from simple, organic molecules under prebiotic conditions is both a thermodynamic and kinetic challenge. Synthesis of such molecules and their subsequent self-assembly into ordered structures requires a favorable source of energy as well as a favorable entropic environment. Our approach couples two such auspicious conditions, using sunlight as the energetic driver and air-water interfaces as the reaction medium. The Sun provides a large, prebiotically relevant source of energy to fuel synthetic photochemistry. Air-water interfaces are widely prevalent on oceans, lakes, and atmospheric aerosols and provide unique reaction environments that ameliorate some of the thermodynamic challenges of the aqueous bulk. Using these experimental principles, we demonstrate the ability to generate chemical complexity via in situ observation of non-enzymatic peptide bond synthesis at the surface of water. Additionally, we will discuss the photochemical formation of a double-tailed membrane component in aqueous solution, which subsequently self-assembles into ordered, three-dimensional structures.

  18. Mutation, DNA strand cleavage and nitric oxide formation caused by N-nitrosoproline with sunlight: a possible mechanism of UVA carcinogenicity.

    PubMed

    Arimoto-Kobayashi, Sakae; Ando, Yoshiko; Horai, Yumi; Okamoto, Keinosuke; Hayatsu, Hikoya; Lowe, Jillian E; Green, Michael H L

    2002-09-01

    N-Nitrosoproline (NPRO) is endogenously formed from proline and nitrite. NPRO has been reported to be nonmutagenic and noncarcinogenic. In this study, we have detected the direct mutagenicity of NPRO plus natural sunlight towards Salmonella typhimurium. Furthermore, formation of 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG), a mutagenic lesion, was observed in calf thymus DNA treated with NPRO plus simulated sunlight. The treatment with NPRO and sunlight induced single strand breaks in the superhelical replicative form of phage M13mp2 DNA. Single-strand DNA breaks also occurred in the human fibroblast cells on treatment with NPRO plus UVA, as detected by the comet assay. An analysis using scavengers suggested that both reactive oxygen species and NO radical mediate the strand breaks. The formation of nitric oxide was observed in NPRO solution irradiated with UVA. We analyzed the photodynamic spectrum of mutation induction and DNA breakage using monochromatic radiation at a series of wavelengths between 300 and 400 nm. Both mutation frequencies and DNA breakage were highest at the absorption maximum of NPRO, 340 nm. The co-mutagenic and co-toxic actions of NPRO and sunlight merit attention as possible mechanisms increasing the carcinogenic risk from UVA irradiation. PMID:12189198

  19. Mixed hemi/ad-micelles coated magnetic nanoparticles for the entrapment of hemoglobin at the surface of a screen-printed carbon electrode and its direct electrochemistry and electrocatalysis.

    PubMed

    Amiri-Aref, Mohaddeseh; Raoof, Jahan Bakhsh; Kiekens, Filip; De Wael, Karolien

    2015-12-15

    An efficient procedure for the physical entrapment of proteins within a biocompatible matrix and their immobilization on electrode surfaces is of utmost importance in the fabrication of biosensors. In this work, the magnetic entrapment of hemoglobin (Hb) at the surface of a screen-printed carbon electrode (SPCE), through mixed hemi/ad-micelles (MHAM) array of positively charged surfactant supported iron oxide magnetic nanoparticles (Mag-NPs), is reported. The Hb/MHAM@Mag-NPs biocomposite is captured at SPCE by a super magnet (Hb/MHAM@Mag-NPs/SPCE). To gain insight in the configuration of the mixed hemi/ad-micelles of CTAB at Mag-NPs, zeta-potential measurements were performed. The entrapment of Hb at MHAM@Mag-NPs was confirmed by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and Fourier transform infrared spectroscopy (FT-IR). Direct electron transfer of the Hb intercalated into the composite film showed a pair of well-defined quasi-reversible redox peak at formal potential of -0.255 V vs. Ag/AgCl corresponding to heme Fe(III)/Fe(II) redox couple. It shows that the MHAM@Mag-NPs composite could increase the adsorption ability for Hb, thus provides a facile direct electron transfer between the Hb and the substrate. The proposed biosensor showed excellent electrocatalytic activity to the H2O2 reduction in the wide concentration range from 5.0 to 300.0 µM obtained by amperometric measurement. The Michaelis-Menten constant (Km) value of Hb at the modified electrode is 55.4 µM, showing its high affinity. Magnetic entrapment offers a promising design for fast, convenient and effective immobilization of protein within a few minutes for determination of the target molecule in low sample volume at disposable cost-effective SPCE. PMID:26183073

  20. Effect of Adding McKenzie Syndrome, Centralization, Directional Preference, and Psychosocial Classification Variables to a Risk-Adjusted Model Predicting Functional Status Outcomes for Patients With Lumbar Impairments.

    PubMed

    Werneke, Mark W; Edmond, Susan; Deutscher, Daniel; Ward, Jason; Grigsby, David; Young, Michelle; McGill, Troy; McClenahan, Brian; Weinberg, Jon; Davidow, Amy L

    2016-09-01

    Study Design Retrospective cohort. Background Patient-classification subgroupings may be important prognostic factors explaining outcomes. Objectives To determine effects of adding classification variables (McKenzie syndrome and pain patterns, including centralization and directional preference; Symptom Checklist Back Pain Prediction Model [SCL BPPM]; and the Fear-Avoidance Beliefs Questionnaire subscales of work and physical activity) to a baseline risk-adjusted model predicting functional status (FS) outcomes. Methods Consecutive patients completed a battery of questionnaires that gathered information on 11 risk-adjustment variables. Physical therapists trained in Mechanical Diagnosis and Therapy methods classified each patient by McKenzie syndromes and pain pattern. Functional status was assessed at discharge by patient-reported outcomes. Only patients with complete data were included. Risk of selection bias was assessed. Prediction of discharge FS was assessed using linear stepwise regression models, allowing 13 variables to enter the model. Significant variables were retained in subsequent models. Model power (R(2)) and beta coefficients for model variables were estimated. Results Two thousand sixty-six patients with lumbar impairments were evaluated. Of those, 994 (48%), 10 (<1%), and 601 (29%) were excluded due to incomplete psychosocial data, McKenzie classification data, and missing FS at discharge, respectively. The final sample for analyses was 723 (35%). Overall R(2) for the baseline prediction FS model was 0.40. Adding classification variables to the baseline model did not result in significant increases in R(2). McKenzie syndrome or pain pattern explained 2.8% and 3.0% of the variance, respectively. When pain pattern and SCL BPPM were added simultaneously, overall model R(2) increased to 0.44. Although none of these increases in R(2) were significant, some classification variables were stronger predictors compared with some other variables included in

  1. Satellite power system (SPS) brightness due to reflected sunlight

    SciTech Connect

    1980-10-01

    The development and operation of a Satellite Power System would place very large structures in orbit around earth for several decades. Sunlight reflected off such structures, particularly specular components from large flat areas, is expected to create ground illumination that will attract observers. In order to assure that this illumination does not exceed the irradiance tolerances of the eye, reflections from these satellites must be carefully controlled by vehicle orientation and surface specifications. The solar power satellite (SPS) at geosynchronous earth orbit (GEO) has 55 km/sup 2/ of glass covered solar cells that are oriented normal to the sun, as well as a 1 km/sup 2/ microwave antenna. Transportation of construction materials from low earth orbit (LEO) to GEO requires 23 Orbit Transfer Vehicles (OTVs) that have 1.6 km/sup 2/ solar panels oriented normal to the sun during their 6 month transits. The Staging Base (SB) at LEO, that accommodates OTV fabrication and cargo transfer, consists of 0.5 km arms protruding from a .44 km/sup 2/ open grid aligned with its orbit plane. Diffuse reflections would make the SB/OTVs readily discernible in the daytime and the OTVs and SPSs observable all night (except during eclipse). Sporadic specular glints would appear on the ground from the OTVs and SPSs near the midnight meridian, from the solar panel surfaces of OTVs during LEO fabrication around midday, and from OTVs near LEO at dawn and dusk. The ground level irradiance has been evaluated for several unusually bright configurations using the present system design. Procedures and results are presented and discussed.

  2. Sunlight Controls Water Column Processing of Carbon in Arctic Freshwaters

    NASA Astrophysics Data System (ADS)

    Cory, R. M.; Ward, C. P.; Crump, B. C.; Kling, G. W.

    2014-12-01

    Carbon (C) in thawing permafrost soils may have global impacts on climate change, yet controls on its processing and fate are poorly understood. The dominant fate of dissolved organic C (DOC) released from soils to inland waters is either complete oxidation to CO2 or partial oxidation and river export to oceans. Both processes are most often attributed to bacterial respiration, but we recently showed that photochemical oxidation exceeds rates of respiration and accounts for 70-95% of total DOC processed in the water column of arctic lakes and rivers. While the overall dominance of photochemical processing in streams and lakes remained, the fate of DOC varied consistently by water type. In small streams DOC was mainly mineralized by sunlight to CO2, while in lakes the main fate of DOC was partial photo-oxidation. Large rivers were intermediate between these end members, and photo-mineralization to CO2 was about equal to or less than partial photo-oxidation. We suggest this pattern is a result of light-exposure history, where DOC leached from soils into headwater streams has little prior light exposure and is labile to complete photo-oxidation, but as light exposure increases moving downstream and into lakes with longer residence times the DOC photo-lability declines. Thus as easily photo-mineralized moieties are removed, DOC fate shifts toward partial photo-oxidation and downstream export in rivers and lakes. At the basin scale, photochemical processing of DOC is about one third of the total CO2 released from surface waters, and is thus an important, newly measured component of the Arctic C budget. We also suggest that these photochemical transformations of DOC will occur in any shallow surface water, and could be important for better understanding inland water carbon cycling.

  3. Biological Effects of Sunlight, Ultraviolet Radiation, Visible Light, Infrared Radiation and Vitamin D for Health.

    PubMed

    Holick, Michael F

    2016-03-01

    Humans evolved in sunlight and had depended on sunlight for its life giving properties that was appreciated by our early ancestors. However, for more than 40 years the lay press and various medical and dermatology associations have denounced sun exposure because of its association with increased risk for skin cancer. The goal of this review is to put into perspective the many health benefits that have been associated with exposure to sunlight, ultraviolet A (UVA) ultraviolet B (UVB), visible and infrared radiation. PMID:26977036

  4. Sunlight suppressing rejection of 280- to 320-nm UV-radiation-induced skin tumors in mice

    SciTech Connect

    Morison, W.L.; Kelley, S.P.

    1985-02-01

    Repeated exposure of female C3H/HeNCR- mice to sunlight prevented the normal immunologic rejection of a UV-induced tumor. This systemic immunologic alteration was transferred to syngeneic lethally X-irradiated animals with lymphoid cells from mice exposed to sunlight. The lymphoid cells also were able to suppress the capacity of lymphoid cells from normal animals to reject a UV-induced tumor. The 295- to 320-nm wave band appeared to be responsible for this immunosuppressive effect of sunlight because suppression was prevented by filtration of the radiation through Mylar and by application of a sunscreen containing para-aminobenzoic acid. These observations may have importance in understanding the pathogenesis of sunlight-induced skin cancer in humans.

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

    PubMed

    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. PMID:22513094

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

    EPA Science Inventory

    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...

  7. PHOTOCHEMICAL TRANSFORMATION OF THE DDT AND METHOXYCHLOR DEGRADATION PRODUCTS, DDE AND DMDE, BY SUNLIGHT

    EPA Science Inventory

    DDE and DMDE, degradation products of the pesticides DDT and methoxychlor, rapidly undergo an unusual photoisomerization in solution when exposed to sunlight. The isomerization involves the exchange of a vinyl chlorine and an ortho aromatic hydrogen. Other photoproducts identifie...

  8. Photolysis study of fluorinated ketones under natural sunlight conditions.

    PubMed

    Díaz-de-Mera, Yolanda; Aranda, Alfonso; Notario, Alberto; Rodríguez, Ana; Rodríguez, Diana; Bravo, Iván

    2015-09-21

    UV-visible absorption cross-sections are reported for CF3C(O)CH3, CF3C(O)CH2CH3, and CH3CH2C(O)CH(CH3)2. The photolysis rate constants of CF3C(O)CH3, CF3C(O)CH2CH3, and CF3CF2C(O)CF(CF3)2 were measured from smog-chamber experiments carried out in a 400 L Teflon-bag reactor under sunlight irradiation. Actinic radiation profiles from the "Tropospheric Ultraviolet and Visible Radiation Model" were used to obtain quantum efficiencies of photolysis: 0.34 ± 0.08, 0.24 ± 0.06, and (4.4 ± 0.6) × 10(-2) for CF3C(O)CH3, CF3C(O)CH2CH3, and CF3CF2C(O)CF(CF3)2, respectively. These values correspond to wavelength ranges of 295-345 nm (for CF3C(O)CH3 and CF3C(O)CH2CH3) and 295-360 nm (for CF3CF2C(O)CF(CF3)2). The photolysis rate constants change significantly with the seasons, with the yearly averages being (2.3 ± 0.7) × 10(-6), (1.8 ± 0.6) × 10(-6), and (2.1 ± 0.8) × 10(-6) s(-1) for CF3C(O)CH3, CF3C(O)CH2CH3, and CF3CF2C(O)CF(CF3)2, respectively. Photolysis processes are fast and responsible for the short gas-phase lifetimes of the studied ketones, which are 5.1 ± 2.2, 6.5 ± 2.5 and 5.5 ± 1.5 days. The radiative forcing efficiencies are provided to assess the contribution of emissions of these gases to climate change. As a result of the short atmospheric lifetimes, their global warming potentials are negligible. Theoretical calculations involving ground and excited states justify the higher photolysis quantum efficiencies of CF3C(O)CH3 and CF3C(O)CH2CH3 compared to CF3CF2C(O)CF(CF3)2, which shows increased photolysis rate constants in the absence of O2. PMID:26270890

  9. Study of enhanced photogalvanic effect of Naphthol Green B in natural sunlight

    NASA Astrophysics Data System (ADS)

    Koli, Pooran

    2015-07-01

    The photogalvanic cells based on Naphthol Green B sensitizer-Fructose reductant-Sodium Lauryl Sulphate surfactant has been studied in natural sunlight. The cell has been found workable in natural sunlight with greatly enhanced optimum cell performance. The 1159.2 μW power, 4500 μA short-circuit current, 1070 mV open-circuit potential, 14.49% efficiency and 240 min storage capacity (as half change time) has been observed in optimum cell fabrication conditions.

  10. Ghost imaging experiment with sunlight compared to laboratory experiment with thermal light

    NASA Astrophysics Data System (ADS)

    Karmakar, Sanjit; Meyers, Ronald; Shih, Yanhua

    2012-10-01

    A recent article reports on the demonstration of ghost imaging using sunlight which also presents theory for ghost imaging in the atmosphere based on two photon interference. The current paper reviews the experiment from a different context than that presented by Karmakar, Meyers and Shih (KMS). Here we examine data from the KMS sunlight ghost imaging experiment and compare it to ghost imaging produced by true thermal light.

  11. A Project in Thermal Physics Involving a Car Parked in Direct Sunlight

    NASA Astrophysics Data System (ADS)

    Lee, Wei; Gilley, Heidi L.; Caris, Joshua B.

    1997-05-01

    A research project for introductory physics students, involving an estimate of the surface temperature of the Sun using a parked car, was carried out in the Summer 1995 Research Apprenticeships in Science Program, sponsored by Edison Industrial Systems Center, for local-area high school students. This activity entails both outdoor quantitative observations and theoretical analysis, and yields a result within 12 percent of the accepted value. It was demonstrated that the use of everyday materials and outdoor observations, such as those in this project, is not only educational but also intriguing. The success of this experiment as a summer research project will be discussed.

  12. Sunlight inactivation of Escherichia coli in waste stabilization microcosms in a sahelian region (Ouagadougou, Burkina Faso).

    PubMed

    Maïga, Ynoussa; Denyigba, Kokou; Wethe, Joseph; Ouattara, Aboubakar Sidiki

    2009-02-01

    Experiments on sunlight inactivation of Escherichia coli were conducted from November 2006 to June 2007 in eight outdoors microcosms with different depths filled with maturation pond wastewater in order to determine pond depth influence on sunlight inactivation of E. coli. The long-term aim was to maximize sunlight inactivation of waterborne pathogens in waste stabilization ponds (WSPs) in sahelian regions where number of sunny days enable longer exposure of wastewater to sunlight. The inactivation was followed during daylight from 8.00 h to 17.00 h and during the night. Sunlight inactivation rates (K(S)), as a function of cumulative global solar radiation (insolation), were 16 and 24 times higher than the corresponding dark inactivation (K(D)) rates, respectively in cold and warm season. In warm season, E. coli was inactivated far more rapidly. Inactivation of E. coli follows the evolution of radiation during the day. In shallow depth microcosms, E. coli was inactivated far more rapidly than in high depth microcosms. The physical chemical parameters [pH, dissolved oxygen (DO)] of microcosms water were higher in shallow depth microcosms than in high depth microcosms suggesting a synergistic effect of sunlight and these parameters to damage E. coli. To increase the efficiency of the elimination of waterborne bacteria, the use of maturation ponds with intermediate depths (0.4m) would be advisable in view of the high temperatures and thus evaporation recorded in sahelian regions. PMID:19084427

  13. Photomodulation of polypeptide conformation by sunlight in spiropyran-containing poly(L-glutamic acid)

    SciTech Connect

    Ciardelli, F. CNR-Center of Stereoordered and Optically Active Macromolecules, Pisa ); Fabbri, D. ); Pieroni, O. CNR-Institute of Biophysics, Pisa )

    1989-04-26

    Photochromic vinyl polymers, such as polyacrylates containing spiropyran groups, were found to undergo photoinduced variations of their viscosity. Since the viscosity of a polymer system is in part a reflection of polymer conformation, the photoviscosity effects were generically attributed to photoinduced conformational changes of the macromolecules. From the point of view of conformational properties, photochromic polypeptides are much more attractive systems, since they can exist in definite ordered structures such as {alpha}-helix or {beta}-structures, and their conformational variations can be directly investigated by means of CD measurements. In addition, their structure is much more relevant to the proteic nature of biological photoreceptors. In this context the authors report the first preparation of a photoresponsive polypeptide containing spiropyran units in the side chains and clear CD evidence that the polypeptide can undergo large random coil {r equilibrium} {alpha}-helix conformational changes upon exposure to sunlight and dark conditions, alternately. Moreover, irradiation in solvent mixtures having appropriate compositions allows the extent of the photoresponse to be controlled.

  14. Sunlight inactivation of somatic coliphage in the presence of natural organic matter.

    PubMed

    Sun, Chen-Xi; Kitajima, Masaaki; Gin, Karina Yew-Hoong

    2016-01-15

    Long wavelengths of sunlight spectrum (UVA and visible light), as well as natural organic matter (NOM) are important environmental factors affecting survival of viruses in aquatic environment through direct and indirect inactivation. In order to understand the virus inactivation kinetics under such conditions, this study investigated the effects of Suwannee River natural organic matter (NOM) on the inactivation of a somatic coliphage, phiX174, by UVA and visible light. Experiments were carried out to examine the virucidal effects of UVA/visible light, assess the influence of SRNOM at different concentrations, and identify the effective ROS in virus inactivation. The results from this study showed that the presence of NOM could either enhance virus inactivation or reduce virus inactivation depending on the concentration, where the inactivation rate followed a parabolic relationship against NOM concentration. The results indicated that moderate levels of NOM (11 ppm) had the strongest antiviral activity, while very low or very high NOM concentrations prolonged virus survival. The results also showed that OH▪ was the primary ROS in causing phiX174 (ssDNA virus) inactivation, unlike previous findings where (1)O2 was the primary ROS causing MS2 (ssRNA virus) inactivation. The phiX174 inactivation by OH∙ could be described as k=3.7 ✕ 10(13)[OH∙]+1.404 (R(2)=0.8527). PMID:26386910

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

    NASA Astrophysics Data System (ADS)

    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.

  16. Sunlight fluorescence observations at 589nm with the SHIELDS spectrometer system: a progress report

    NASA Astrophysics Data System (ADS)

    Watchorn, S.; Noto, J.; Anderson, J.; Sioris, C. E.

    2010-08-01

    The background and beginning of this project have been described in previous SPIE papers1,2. Since then, atmospheric modeling work on the project has been completed, and the dual-wavelength monolith has been fabricated and fully tested3. The full sodium-wavelength SHIELDS unit was assembled and initially tested with a sodium lamp in 2009, and the project has now turned to that focus in earnest. A full workup with the sodium lamp has been completed, and the unit has started observing a fluorophore target (UV Green) illuminated with both a continuous white-light bulb and with sunlight from the day sky. In both cases, a narrow continuum fringe pattern was observed, but the pattern was too narrow in the spectral direction to extract, as of this writing, the absorption structure necessary to execute Fraunhofer Line Discrimination (FLD). The problem may be an unnecessarily broad sodium line filter. Tests with a narrower line filter in the optical path will be completed in July 2010, and determination of progress and next steps will be made at that time.

  17. The AdS particle [rapid communication

    NASA Astrophysics Data System (ADS)

    Ghosh, Subir

    2005-09-01

    In this Letter we have considered a relativistic Nambu-Goto model for a particle in AdS metric. With appropriate gauge choice to fix the reparameterization invariance, we recover the previously discussed [S. Ghosh, P. Pal, Phys. Lett. B 618 (2005) 243, arxiv:hep-th/0502192] "exotic oscillator". The Snyder algebra and subsequently the κ-Minkowski spacetime are also derived. Lastly we comment on the impossibility of constructing a non-commutative spacetime in the context of open string where only a curved target space is introduced.

  18. Sensitized photodecomposition of high disperse pesticide chemicals exposed to sunlight and irradiation from halogen or mercury lamp

    NASA Astrophysics Data System (ADS)

    Samsonov, Yury N.; Pokrovskii, Leonid M.

    The kinetics of sensitized photolysis for four pesticides, deltamethrin (Decis), acrinathrin (Rufast), s-fenvalerate (Sumialpha), and propiconazol (Tilt) in thin films and aerosol particles was investigated under sunlight or the irradiation from halogen or mercury lamp. The peculiarities of principle of the photochemistry of pesticides in high disperse substance state were discussed. The quantum yields of sensitized and direct photolysis were measured, and the phenomenological kinetic mechanism of photolysis was proposed and examined. Four relations between six rate constants of reaction steps of the kinetic mechanism were determined. The use of sensitizers to accelerate the decomposition rates of pesticide pollutants under sunlight could minimize the contamination of agricultural commodities and the adjacent environment. The Shirvanol 2 sensitizer (a by-product of the full treatment of Caspian oils) can regulate decomposition of many pesticides in a wide range of photolysis rates, so that practically any desired lifetime could be really available for either pesticide residues on plant foliage or pesticide aerosol particles in the air.

  19. Sunlight-Sensitive Anti-Fouling Nanostructured TiO2 coated Cu Meshes for Ultrafast Oily Water Treatment

    NASA Astrophysics Data System (ADS)

    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.

  20. Polydopamine-Coated Porous Substrates as a Platform for Mineralized β-FeOOH Nanorods with Photocatalysis under Sunlight.

    PubMed

    Zhang, Chao; Yang, Hao-Cheng; Wan, Ling-Shu; Liang, Hong-Qing; Li, Hanying; Xu, Zhi-Kang

    2015-06-01

    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. PMID:25969860

  1. Sunlight-Sensitive Anti-Fouling Nanostructured TiO2 coated Cu Meshes for Ultrafast Oily Water Treatment

    PubMed Central

    Liu, HaoRan; Raza, Aikifa; Aili, Abulimiti; Lu, JinYou; AlGhaferi, Amal; Zhang, TieJun

    2016-01-01

    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. PMID:27160349

  2. Sunlight-Sensitive Anti-Fouling Nanostructured TiO2 coated Cu Meshes for Ultrafast Oily Water Treatment.

    PubMed

    Liu, HaoRan; Raza, Aikifa; Aili, Abulimiti; Lu, JinYou; AlGhaferi, Amal; Zhang, TieJun

    2016-01-01

    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. PMID:27160349

  3. Natural Sunlight Shapes Crude Oil-Degrading Bacterial Communities in Northern Gulf of Mexico Surface Waters

    PubMed Central

    Bacosa, Hernando P.; Liu, Zhanfei; Erdner, Deana L.

    2015-01-01

    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 days 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. PMID:26648916

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

    PubMed

    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. PMID:27162069

  5. Natural Sunlight Shapes Crude Oil-Degrading Bacterial Communities in Northern Gulf of Mexico Surface Waters.

    PubMed

    Bacosa, Hernando P; Liu, Zhanfei; Erdner, Deana L

    2015-01-01

    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 days 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. PMID:26648916

  6. AdS3: the NHEK generation

    NASA Astrophysics Data System (ADS)

    Bena, Iosif; Heurtier, Lucien; Puhm, Andrea

    2016-05-01

    It was argued in [1] that the five-dimensional near-horizon extremal Kerr (NHEK) geometry can be embedded in String Theory as the infrared region of an infinite family of non-supersymmetric geometries that have D1, D5, momentum and KK monopole charges. We show that there exists a method to embed these geometries into asymptotically- {AdS}_3× {S}^3/{{Z}}_N solutions, and hence to obtain infinite families of flows whose infrared is NHEK. This indicates that the CFT dual to the NHEK geometry is the IR fixed point of a Renormalization Group flow from a known local UV CFT and opens the door to its explicit construction.

  7. Shadows, currents, and AdS fields

    SciTech Connect

    Metsaev, R. R.

    2008-11-15

    Conformal totally symmetric arbitrary spin currents and shadow fields in flat space-time of dimension greater than or equal to four are studied. A gauge invariant formulation for such currents and shadow fields is developed. Gauge symmetries are realized by involving the Stueckelberg fields. A realization of global conformal boost symmetries is obtained. Gauge invariant differential constraints for currents and shadow fields are obtained. AdS/CFT correspondence for currents and shadow fields and the respective normalizable and non-normalizable solutions of massless totally symmetric arbitrary spin AdS fields are studied. The bulk fields are considered in a modified de Donder gauge that leads to decoupled equations of motion. We demonstrate that leftover on shell gauge symmetries of bulk fields correspond to gauge symmetries of boundary currents and shadow fields, while the modified de Donder gauge conditions for bulk fields correspond to differential constraints for boundary conformal currents and shadow fields. Breaking conformal symmetries, we find interrelations between the gauge invariant formulation of the currents and shadow fields, and the gauge invariant formulation of massive fields.

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

    PubMed Central

    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 < 0.05). Crude odds ratios (ORs) for PD in the quartiles of serum 25(OH)D were 1 (reference), 0.710 (0.401, 1.257), 0.631 (0.348, 1.209), and 0.483 (0.267, 0.874), respectively. Crude ORs for PD in quartiles of 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

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

    NASA Astrophysics Data System (ADS)

    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.

  10. Residential sunlight exposure is associated with a decreased risk of prostate cancer.

    PubMed

    John, Esther M; Dreon, Darlene M; Koo, Jocelyn; Schwartz, Gary G

    2004-05-01

    The possibility that exposure to sunlight reduces the risk of clinical prostate cancer has been strongly suggested by ecologic data. However, data on prostate cancer risk in relation to sunlight exposure in individuals are sparse. We analyzed data from the First National Health and Nutrition Examination Survey (NHANES I) Epidemiologic Follow-up Study in order to test the hypothesis that residential sunlight exposure reduces the risk of prostate cancer. We identified 153 men with incident prostate cancer from a cohort of 3414 white men who completed the baseline interview and dermatologic examination in 1971-1975 and were followed up to 1992. We used Cox proportional hazards modeling to estimate relative risks (RR) and 95% confidence intervals (CI) for measures of residential sunlight exposure, adjusting for age, family history of prostate cancer, and dietary intake of fat and calcium. Residence in the South at baseline (RR = 0.68, CI = 0.41-1.13), state of longest residence in the South (RR = 0.62, CI = 0.40-0.95), and high solar radiation in the state of birth (RR = 0.49, CI = 0.30-0.79) were associated with significant and substantial reductions in prostate cancer risk. These data support the hypothesis that sunlight exposure reduces the risk of prostate cancer and have important implications for prostate cancer prevention. PMID:15225836

  11. Sunlight-readable display technology: a dual-use case study

    NASA Astrophysics Data System (ADS)

    Blanchard, Randall D.

    1996-05-01

    This paper describes our vision of sunlight readable color display requirements, an alternate technology that offers a high level of performance, and how we implemented it for the military avionics display market. This knowledge base and product development experience was then applied with a comparable level of performance to commercial applications. The successful dual use of this technology for these two diverse markets is presented. Details of the technical commonality and a comparison of the design and performance differences are presented. A basis for specifying the required level of performance for a sunlight readable full color display is discussed. With the objective of providing a high level of image brightness and high ambient light rejection, a display architecture using collimated light is used. The resulting designs of two military cockpit display products, with contrast ratios above 20:1 in sunlight are shown. The performance of a commercial display providing several thousand foot- Lamberts of image brightness is presented.

  12. Interface Effects in Sunlight-Driven Ag/g-C3N4 Composite Catalysts: Study of the Toluene Photodegradation Quantum Efficiency.

    PubMed

    Fontelles-Carceller, Olga; Muñoz-Batista, Mario J; Fernández-García, Marcos; Kubacka, Anna

    2016-02-01

    Metallic silver (ranging from 1 to 10 wt %) was deposited onto a graphite-like carbon nitride photocatalyst through a microemultion method. Surface, morphological, and structural properties of the resulting materials were characterized using BET and porosity measurements, X-ray diffraction, X-ray photoelectron spectroscopy, transmission electron microscopy, and UV-vis and photoluminescence spectroscopy. The activity of the composite samples under sunlight-type and visible illumination was measured for toluene photodegradation and was analyzed by means of the reaction rate and the quantum efficiency parameter. To obtain the latter observable, the lamp emission properties as well as the radiation field interaction with the catalyst inside the reactor were modeled and numerically calculated. The stability of the samples under both illumination conditions was also studied. The results evidence that the composite samples containing 1-10 silver wt % outperform carbon nitride for sunlight-type and visible illumination, but the optimal use of the charge generated after light absorption is obtained for the sample with 1 wt % of silver acording to the quantum efficiency calculation. The study shows that the optimum silver-g-C3N4 contact is able to outperform TiO2 reference systems (nano-TiO2 and P25) under sunlight illumination and points out that this occurs as a direct consequence of the charge handling through the interface between catalyst components. This indicates that composite systems based on g-C3N4 can be competitive in sunlight-triggered photodegradation processes to eliminate tough polluctants such as toluene, rendering active and stable systems. PMID:26714203

  13. On deformations of AdS n × S n supercosets

    NASA Astrophysics Data System (ADS)

    Hoare, B.; Roiban, R.; Tseytlin, A. A.

    2014-06-01

    We study the deformed AdS 5 × S 5 supercoset model of arXiv:1309.5850 which depends on one parameter κ and has classical quantum group symmetry. We confirm the conjecture that in the "maximal" deformation limit, κ → ∞, this model is T-dual to "flipped" double Wick rotation of the target space AdS 5 × S 5, i.e. dS 5 × H 5 space supported by an imaginary 5-form flux. In the imaginary deformation limit, κ → i, the corresponding target space metric is of a pp-wave type and thus the resulting light-cone gauge S-matrix becomes relativistically invariant. Omitting non-unitary contributions of imaginary WZ terms, we find that this tree-level S-matrix is equivalent to that of the generalized sine-Gordon model representing the Pohlmeyer reduction of the undeformed AdS 5 × S 5 superstring model. We also study in some detail similar deformations of the AdS 3 × S 3 and AdS 2 × S 2 supercosets. The bosonic part of the deformed AdS 3 × S 3 model happens to be equivalent to the symmetric case of the sum of the Fateev integrable deformation of the SL(2) and SU(2) principal chiral models, while in the AdS 2 × S 2 case the role of the Fateev model is played by the 2d "sausage" model. The κ = i limits are again directly related to the Pohlmeyer reductions of the corresponding AdS n × S n supercosets: (2,2) super sine-Gordon model and its complex sine-Gordon analog. We also discuss possible deformations of AdS 3 × S 3 with more than one parameter.

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

    PubMed

    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. PMID:3116308

  15. Errors in short circuit measurements due to spectral mismatch between sunlight and solar simulators

    NASA Technical Reports Server (NTRS)

    Curtis, H. B.

    1976-01-01

    Errors in short circuit current measurement were calculated for a variety of spectral mismatch conditions. The differences in spectral irradiance between terrestrial sunlight and three types of solar simulator were studied, as well as the differences in spectral response between three types of reference solar cells and various test cells. The simulators considered were a short arc xenon lamp AMO sunlight simulator, an ordinary quartz halogen lamp, and an ELH-type quartz halogen lamp. Three types of solar cells studied were a silicon cell, a cadmium sulfide cell and a gallium arsenide cell.

  16. Natural sunlight NO(3)(-)/NO(2)(-)-induced photo-degradation of phenylurea herbicides in water.

    PubMed

    Shankar, M V; Nélieu, S; Kerhoas, L; Einhorn, J

    2008-04-01

    The nitrate-induced photodegradation of phenylureas in water was demonstrated to occur efficiently using natural sunlight irradiation. The kinetics of disappearance was found to be dependent on the inducer and substrate concentrations, the phenylurea structure and the origin and composition of the aqueous matrix including the presence of nitrite. The measured effects under sunlight were of the same order of those measured previously in the lab using our solar light simulated system. However, by-product distribution might differ substantially particularly considering the nitration pathway. PMID:18262593

  17. ADS pilot program Plan

    NASA Technical Reports Server (NTRS)

    Clauson, J.; Heuser, J.

    1981-01-01

    The Applications Data Service (ADS) is a system based on an electronic data communications network which will permit scientists to share the data stored in data bases at universities and at government and private installations. It is designed to allow users to readily locate and access high quality, timely data from multiple sources. The ADS Pilot program objectives and the current plans for accomplishing those objectives are described.

  18. Detecting Super-Thin Clouds with Polarized Sunlight

    NASA Technical Reports Server (NTRS)

    Sun, Wenbo; Videen, Gorden; Mishchenko, Michael I.

    2014-01-01

    We report a novel method for detecting cloud particles in the atmosphere. Solar radiation backscattered from clouds is studied with both satellite data and a radiative transfer model. A distinct feature is found in the angle of linear polarization of solar radiation that is backscattered from clouds. The dominant backscattered electric field from the clear-sky Earth-atmosphere system is nearly parallel to the Earth surface. However, when clouds are present, this electric field can rotate significantly away from the parallel direction. Model results demonstrate that this polarization feature can be used to detect super-thin cirrus clouds having an optical depth of only 0.06 and super-thin liquid water clouds having an optical depth of only 0.01. Such clouds are too thin to be sensed using any current passive satellite instruments.

  19. Holography beyond conformal invariance and AdS isometry?

    SciTech Connect

    Barvinsky, A. O.

    2015-03-15

    We suggest that the principle of holographic duality be extended beyond conformal invariance and AdS isometry. Such an extension is based on a special relation between functional determinants of the operators acting in the bulk and on its boundary, provided that the boundary operator represents the inverse propagators of the theory induced on the boundary by the Dirichlet boundary value problem in the bulk spacetime. This relation holds for operators of a general spin-tensor structure on generic manifolds with boundaries irrespective of their background geometry and conformal invariance, and it apparently underlies numerous O(N{sup 0}) tests of the AdS/CFT correspondence, based on direct calculation of the bulk and boundary partition functions, Casimir energies, and conformal anomalies. The generalized holographic duality is discussed within the concept of the “double-trace” deformation of the boundary theory, which is responsible in the case of large-N CFT coupled to the tower of higher-spin gauge fields for the renormalization group flow between infrared and ultraviolet fixed points. Potential extension of this method beyond the one-loop order is also briefly discussed.

  20. Holography beyond conformal invariance and AdS isometry?

    NASA Astrophysics Data System (ADS)

    Barvinsky, A. O.

    2015-03-01

    We suggest that the principle of holographic duality be extended beyond conformal invariance and AdS isometry. Such an extension is based on a special relation between functional determinants of the operators acting in the bulk and on its boundary, provided that the boundary operator represents the inverse propagators of the theory induced on the boundary by the Dirichlet boundary value problem in the bulk spacetime. This relation holds for operators of a general spin-tensor structure on generic manifolds with boundaries irrespective of their background geometry and conformal invariance, and it apparently underlies numerous O( N 0) tests of the AdS/CFT correspondence, based on direct calculation of the bulk and boundary partition functions, Casimir energies, and conformal anomalies. The generalized holographic duality is discussed within the concept of the "double-trace" deformation of the boundary theory, which is responsible in the case of large- N CFT coupled to the tower of higher-spin gauge fields for the renormalization group flow between infrared and ultraviolet fixed points. Potential extension of this method beyond the one-loop order is also briefly discussed.

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

    NASA Astrophysics Data System (ADS)

    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.

  2. Effect of Humic Acid and Sunlight on the Generation of aqu/C60

    EPA Science Inventory

    Little is known about the effect of sunlight and natural organic matter, such as humic acid, on the aqueous suspension of fullerene C60. This knowledge gap limits our ability to determine the environmental impact of potential environmental releases of these materials. Aqueous sus...

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

    ERIC Educational Resources Information Center

    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…

  4. Facile synthesis of sunlight-driven AgCI:Ag plasmonic nanophotocatalyst.

    SciTech Connect

    An, C.; Peng, S.; Sun, Y.; Center for Nanoscale Materials; Univ. of Illinois

    2010-06-18

    Highly efficient plasmonic photocatalysts of AgCl:Ag hybrid nanoparticles are successfully synthesized via a one-pot synthetic approach involving a precipitation reaction followed by polyol reduction. The as-synthesized nanoparticles exhibit high catalytic performance under visible light and sunlight for decomposing organics, such as methylene blue.

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

    PubMed

    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. PMID:27492302

  6. Competitive Interaction of Axonopus compressus and Asystasia gangetica under Contrasting Sunlight Intensity

    PubMed Central

    Samedani, B.; Juraimi, A. S.; Anwar, M. P.; Rafii, M. Y.; Sheikh Awadz, S. H.; Anuar, A. R.

    2013-01-01

    Axonopus compressus is one of the native soft grass species in oil palm in Malaysia which can be used as a cover crop. The competitive ability of A. compressus to overcome A. gangetica was studied using multiple-density, multiple-proportion replacements series under a glasshouse and full sunlight conditions in a poly bag for 10 weeks. A. compressus produced more dry weight and leaf area when competing against A. gangetica than in monoculture at both densities in the full sunlight and at high density in the shade. Moreover, the relative yield and relative crowding coefficients also indicated A. compressus is a stronger competitor than A. gangetica at both densities in the full sunlight and high density in the shade. It seemed that A. gangetica plants in the shade did not compete with each other and were more competitive against A. compressus as could influence A. compressus height in the shade. It is concluded that although suppression of A. gangetica by A. compressus occurred under full sunlight, irrespective of plant density, this ability reduced under shade as A. compressus density decreased. The result suggests that A. compressus in high density could be considered as a candidate for cover crops under oil palm canopy. PMID:24163618

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

    PubMed

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

    2010-11-01

    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. PMID:21165097

  8. ATTENUATION OF METHYL TERT-BUTYL ETHER IN WATER USING SUNLIGHT AND A PHOTOCATALYST: JOURNAL ARTICLE

    EPA Science Inventory

    NRMRL-CIN-1535 Sahle-Demessie*, E., Enriquez*, J., and Gupta, G. Attenuation of Methyl tert-Butyl Ether in Water using Sunlight and a Photocatalyst. Water Environment Research (Virginia: Water Environment Federation) 74 (2):122-130 (2002). EPA/600/J-02/236. 07/19/2001 The use o...

  9. The forecaster's added value

    NASA Astrophysics Data System (ADS)

    Turco, M.; Milelli, M.

    2009-09-01

    skill scores of two competitive forecast. It is important to underline that the conclusions refer to the analysis of the Piemonte operational alert system, so they cannot be directly taken as universally true. But we think that some of the main lessons that can be derived from this study could be useful for the meteorological community. In details, the main conclusions are the following: - despite the overall improvement in global scale and the fact that the resolution of the limited area models has increased considerably over recent years, the QPF produced by the meteorological models involved in this study has not improved enough to allow its direct use, that is, the subjective HQPF continues to offer the best performance; - in the forecast process, the step where humans have the largest added value with respect to mathematical models, is the communication. In fact the human characterisation and communication of the forecast uncertainty to end users cannot be replaced by any computer code; - eventually, although there is no novelty in this study, we would like to show that the correct application of appropriated statistical techniques permits a better definition and quantification of the errors and, mostly important, allows a correct (unbiased) communication between forecasters and decision makers.

  10. 78 FR 45922 - Desert Sunlight 300, LLC; Supplemental Notice That Initial Market-Based Rate Filing Includes...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-30

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission Desert Sunlight 300, LLC; Supplemental Notice That Initial Market-Based Rate...-referenced proceeding, of Desert Sunlight 300, LLC's application for market-based rate authority, with...

  11. 78 FR 45521 - Desert Sunlight 250, LLC; Supplemental Notice That Initial Market-Based Rate Filing Includes...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-29

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission Desert Sunlight 250, LLC; Supplemental Notice That Initial Market-Based Rate...-referenced proceeding, of Desert Sunlight 250, LLC's application for market-based rate authority, with...

  12. 76 FR 50493 - Notice of Availability of the Record of Decision for the Desert Sunlight Holdings, LLC, Desert...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-15

    ... on April 15, 2011 (76 FR 21402). Publication of the Notice of Availability for the Final EIS... Holdings, LLC, Desert Sunlight Solar Farm (DSSF) and California Desert Conservation Area Plan Amendment... . SUPPLEMENTARY INFORMATION: Desert Sunlight Holdings, LLC, a wholly owned subsidiary of First Solar, Inc.,...

  13. Oxidation and biodegradation of polyethylene films containing pro-oxidantadditives: Synergistic effects of sunlight exposure, thermal aging and fungal biodegradation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Synergistic effects of sunlight exposure, thermal aging and fungal biodegradation on the oxidation and biodegradation of linear low density poly (ethylene) PE-LLD films containing pro-oxidant were examined. To achieve oxidation and degradation, films were first exposed to the sunlight for 93 days du...

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

    PubMed

    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. PMID:26866294

  15. Dietary calcein marking of shovelnose sturgeon and the effect of sunlight on mark retention

    USGS Publications Warehouse

    Honeyfield, D.C.; Kindschi, G.A.; Bell, T.A.; Mohler, J.W.

    2011-01-01

    Calcein, a fluorochrome dye, is a potential fish-marking agent that has not been evaluated in sturgeon. Shovelnose sturgeon Scaphirhynchus platorynchus (average weight, 9.7 g) were fed calcein, immersed in a calcein bath, or left unmarked to determine calcein mark intensity. In the first study, six treatments were evaluated in a two-by-three factorial arrangement. Feed was formulated with 2.0 g of SE-MARK/kg either as powder or in an encapsulated form. Sturgeon were fed the test diets for 5, 10, or 15 d. They readily ate feed containing powdered or encapsulated calcein. Sturgeon fed powdered calcein had more brilliant marks than those fed encapsulated calcein (8.27 versus 4.66 lm; P < 0.03) 6 months postexposure. Fish fed calcein for 15 d (11.26 lm) were more brilliant (P < 0.002) than fish fed for either 5 d (3.02 lm) or 10 d (5.11 lm). Post hoc comparison of the three treatment groups showed that sturgeon fed powdered calcein for 15 d (14.06 lm) were brighter (P < 0.01) than fish fed encapsulated calcein (8.46 lm) or fish immersed in calcein (9.68 lm). In the second study, previouslymarked sturgeon were exposed to sunlight for 14months to determine their retention of calcein marks. Dorsal marks were no longer visible on fish exposed to 100% sunlight after 8 weeks. Most but not all fish exposed to 20% sunlight had no discernable dorsalmarks after 8 weeks, but ventral marks at the pectoral fin girdle were present on all fish in the 0% and 20% sunlight exposure treatments. Feeding calcein for 15 d appears to have excellent potential for practical application, such as distinguishing hatchery-reared from wild fish. Ventral calcein marks remained visible after 14 months of exposure to 20% sunlight when sturgeon were reared in clear water. ?? American Fisheries Society 2011.

  16. Photosynthesis, photoprotection, and growth of shade-tolerant tropical tree seedlings under full sunlight.

    PubMed

    Krause, G Heinrich; Winter, Klaus; Matsubara, Shizue; Krause, Barbara; Jahns, Peter; Virgo, Aurelio; Aranda, Jorge; García, Milton

    2012-09-01

    High solar radiation in the tropics is known to cause transient reduction in photosystem II (PSII) efficiency and CO(2) assimilation in sun-exposed leaves, but little is known how these responses affect the actual growth performance of tropical plants. The present study addresses this question. Seedlings of five woody neotropical forest species were cultivated under full sunlight and shaded conditions. In full sunlight, strong photoinhibition of PSII at midday was documented for the late-successional tree species Ormosia macrocalyx and Tetragastris panamensis and the understory/forest gap species, Piper reticulatum. In leaves of O. macrocalyx, PSII inhibition was accompanied by substantial midday depression of net CO(2) assimilation. Leaves of all species had increased pools of violaxanthin-cycle pigments. Other features of photoacclimation, such as increased Chl a/b ratio and contents of lutein, β-carotene and tocopherol varied. High light caused strong increase of tocopherol in leaves of T. panamensis and another late-successional species, Virola surinamensis. O. macrocalyx had low contents of tocopherol and UV-absorbing substances. Under full sunlight, biomass accumulation was not reduced in seedlings of T. panamensis, P. reticulatum, and V. surinamensis, but O. macrocalyx exhibited substantial growth inhibition. In the highly shade-tolerant understory species Psychotria marginata, full sunlight caused strongly reduced growth of most individuals. However, some plants showed relatively high growth rates under full sun approaching those of seedlings at 40 % ambient irradiance. It is concluded that shade-tolerant tropical tree seedlings can achieve efficient photoacclimation and high growth rates in full sunlight. PMID:22466529

  17. A novel apparatus to measure reflected sunlight from the Moon

    NASA Astrophysics Data System (ADS)

    Cramer, Claire E.; Fraser, Gerald T.; Lykke, Keith R.; Smith, Allan W.; Woodward, John T.

    2013-09-01

    We describe a new apparatus for measuring the spectral irradiance of the Moon at visible wavelengths. Our effort builds upon the United States Geological Survey's highly successful Robotic Lunar Observatory (ROLO), which determined a precise model for the time-dependent irradiance of the Moon from six years of observations obtained with an imaging telescope equipped with a set of narrow-band filters. The ROLO Irradiance Model allows the Moon to be used as a radiometric reference for tracking changes in the absolute responsivity of near-infrared to visible satellite sensors as a function of time to better than 1 %. The goal of the present effort is to improve the absolute radiometric accuracy of the ROLO model, presently estimated at 5 % - 10 %, to better than 1 %. Our approach, which uses an integrating sphere at the focal plane of a telescope to direct light from the integrated lunar disk into a stable spectrograph, also eliminates the need to interpolate between the 32 visible and near-infrared bands measured by ROLO. The new measurements will allow weather, climate, land-surface, and defense satellites to use the Moon as an absolute calibration reference, potentially reducing the impact of disruptions in continuous long-term climate data records caused by gaps in satellitesensor coverage.

  18. Transcriptome Analysis of Plant Hormone-Related Tomato (Solanum lycopersicum) Genes in a Sunlight-Type Plant Factory

    PubMed Central

    Tanigaki, Yusuke; Higashi, Takanobu; Takayama, Kotaro; Nagano, Atsushi J.; Honjo, Mie N.; Fukuda, Hirokazu

    2015-01-01

    In plant factories, measurements of plant conditions are necessary at an early stage of growth to predict harvest times of high value-added crops. Moreover, harvest qualities depend largely on environmental stresses that elicit plant hormone responses. However, the complexities of plant hormone networks have not been characterized under nonstress conditions. In the present study, we determined temporal expression profiles of all genes and then focused on plant hormone pathways using RNA-Seq analyses of gene expression in tomato leaves every 2 h for 48 h. In these experiments, temporally expressed genes were found in the hormone synthesis pathways for salicylic acid, abscisic acid, ethylene, and jasmonic acid. The timing of CAB expression 1 (TOC1) and abscisic acid insensitive 1 (ABA1) and open stomata 1 (OST1) control gating stomata. In this study, compare with tomato and Arabidopsis thaliana, expression patterns of TOC1 have similarity. In contrast, expression patterns of tomato ABI1 and OST1 had expression peak at different time. These findings suggest that the regulation of gating stomata does not depend predominantly on TOC1 and significantly reflects the extracellular environment. The present data provide new insights into relationships between temporally expressed plant hormone-related genes and clock genes under normal sunlight conditions. PMID:26624004

  19. Transcriptome Analysis of Plant Hormone-Related Tomato (Solanum lycopersicum) Genes in a Sunlight-Type Plant Factory.

    PubMed

    Tanigaki, Yusuke; Higashi, Takanobu; Takayama, Kotaro; Nagano, Atsushi J; Honjo, Mie N; Fukuda, Hirokazu

    2015-01-01

    In plant factories, measurements of plant conditions are necessary at an early stage of growth to predict harvest times of high value-added crops. Moreover, harvest qualities depend largely on environmental stresses that elicit plant hormone responses. However, the complexities of plant hormone networks have not been characterized under nonstress conditions. In the present study, we determined temporal expression profiles of all genes and then focused on plant hormone pathways using RNA-Seq analyses of gene expression in tomato leaves every 2 h for 48 h. In these experiments, temporally expressed genes were found in the hormone synthesis pathways for salicylic acid, abscisic acid, ethylene, and jasmonic acid. The timing of CAB expression 1 (TOC1) and abscisic acid insensitive 1 (ABA1) and open stomata 1 (OST1) control gating stomata. In this study, compare with tomato and Arabidopsis thaliana, expression patterns of TOC1 have similarity. In contrast, expression patterns of tomato ABI1 and OST1 had expression peak at different time. These findings suggest that the regulation of gating stomata does not depend predominantly on TOC1 and significantly reflects the extracellular environment. The present data provide new insights into relationships between temporally expressed plant hormone-related genes and clock genes under normal sunlight conditions. PMID:26624004

  20. Residential and occupational exposure to sunlight and mortality from non-Hodgkin's lymphoma: composite (threefold) case-control study.

    PubMed Central

    Freedman, D. M.; Zahm, S. H.; Dosemeci, M.

    1997-01-01

    OBJECTIVE: To determine whether non-Hodgkin's lymphoma mortality is associated with sunlight exposure. DESIGN: Three case-control studies based on death certificates of non-Hodgkin's lymphoma, melanoma, and skin cancer mortality examining associations with potential sunlight exposure from residence and occupation. SETTING: 24 states in the United States. SUBJECTS: All cases were deaths from non-Hodgkin's lymphoma, melanoma, and non-melanotic skin cancer between 1984 and 1991. Two age, sex, and race frequency matched controls per case were selected from non-cancer deaths. MAIN OUTCOME MEASURES: Odds ratios for non-Hodgkin's lymphoma, melanoma, and skin cancer from residential and occupational sunlight exposure adjusted for age, sex, race, socioeconomic status, and farming occupation. RESULTS: Non-Hodgkin's lymphoma mortality was not positively associated with sunlight exposure based on residence. Both melanoma and skin cancer were positively associated with residential sunlight exposure. Adjusted odds ratios for residing in states with the highest sunlight exposure were 0.83 (95% confidence interval 0.81 to 0.86) for non-Hodgkin's lymphoma, 1.12 (1.06 to 1.19) for melanoma, and 1.30 (1.18 to 1.43) for skin cancer. In addition, non-Hodgkin's lymphoma mortality was not positively associated with occupational sunlight exposure (odds ratio 0.88; 0.81 to 0.96). Skin cancer was slightly positively associated with occupational sunlight exposure (1.14; 0.96 to 1.36). CONCLUSIONS: Unlike skin cancer and to some extent melanoma, non-Hodgkin's lymphoma mortality was not positively associated with exposure to sunlight. The findings do not therefore support the hypothesis that sunlight exposure contributes to the rising rates of non-Hodgkin's lymphoma. PMID:9167561

  1. What Value "Value Added"?

    ERIC Educational Resources Information Center

    Richards, Andrew

    2015-01-01

    Two quantitative measures of school performance are currently used, the average points score (APS) at Key Stage 2 and value-added (VA), which measures the rate of academic improvement between Key Stage 1 and 2. These figures are used by parents and the Office for Standards in Education to make judgements and comparisons. However, simple…

  2. Innovations Without Added Costs

    ERIC Educational Resources Information Center

    Cereghino, Edward

    1974-01-01

    There is no question that we are in a tight money market, and schools are among the first institutions to feel the squeeze. Therefore, when a plan is offered that provides for innovations without added costs, its something worth noting. (Editor)

  3. Introducing ADS Labs

    NASA Astrophysics Data System (ADS)

    Accomazzi, Alberto; Henneken, E.; Grant, C. S.; Kurtz, M. J.; Di Milia, G.; Luker, J.; Thompson, D. M.; Bohlen, E.; Murray, S. S.

    2011-05-01

    ADS Labs is a platform that ADS is introducing in order to test and receive feedback from the community on new technologies and prototype services. Currently, ADS Labs features a new interface for abstract searches, faceted filtering of results, visualization of co-authorship networks, article-level recommendations, and a full-text search service. The streamlined abstract search interface provides a simple, one-box search with options for ranking results based on a paper relevancy, freshness, number of citations, and downloads. In addition, it provides advanced rankings based on collaborative filtering techniques. The faceted filtering interface allows users to narrow search results based on a particular property or set of properties ("facets"), allowing users to manage large lists and explore the relationship between them. For any set or sub-set of records, the co-authorship network can be visualized in an interactive way, offering a view of the distribution of contributors and their inter-relationships. This provides an immediate way to detect groups and collaborations involved in a particular research field. For a majority of papers in Astronomy, our new interface will provide a list of related articles of potential interest. The recommendations are based on a number of factors, including text similarity, citations, and co-readership information. The new full-text search interface allows users to find all instances of particular words or phrases in the body of the articles in our full-text archive. This includes all of the scanned literature in ADS as well as a select portion of the current astronomical literature, including ApJ, ApJS, AJ, MNRAS, PASP, A&A, and soon additional content from Springer journals. Fulltext search results include a list of the matching papers as well as a list of "snippets" of text highlighting the context in which the search terms were found. ADS Labs is available at http://adslabs.org

  4. Transparent sunlight conversion film based on carboxymethyl cellulose and carbon dots.

    PubMed

    You, Yaqin; Zhang, Haoran; Liu, Yingliang; Lei, Bingfu

    2016-10-20

    Transparent sunlight conversion film based on carboxymethyl cellulose (CMC) and carbon dots (CDs) has been developed for the first time through dispersion of CDs in CMC aqueous solution. Due to the hydrogen bonds interaction, CMC can effectively absorb the CDs, whose surfaces are functionalized by lots of polar groups. The results from atomic force microscopy (AFM), scanning electron microscopy (SEM) confirm that the composite film possesses a homogeneous and compact structure. Besides, the CMC matrix neither competes for absorbing excitation light nor absorbs the emissions of CDs, which reserves the inherent optical properties of the individual CDs. The composite films can efficiently convert ultraviolet light to blue light. What's more, the film is transparent and possesses excellent mechanical properties, expected to apply in the field of agricultural planting for sunlight conversion. PMID:27474564

  5. Nanocomposite heterojunctions as sunlight-driven photocatalysts for hydrogen production from water splitting.

    PubMed

    Reza Gholipour, Mohammad; Dinh, Cao-Thang; Béland, François; Do, Trong-On

    2015-05-14

    Hydrogen production via photocatalytic water splitting using sunlight has enormous potential in solving the worldwide energy and environmental crisis. The key challenge in this process is to develop efficient photocatalysts which must satisfy several criteria such as high chemical and photochemical stability, effective charge separation and strong sunlight absorption. The combination of different semiconductors to create composite materials offers a promising way to achieve efficient photocatalysts because doing so can improve the charge separation, light absorption and stability of the photocatalysts. In this review article, we summarized the most recent studies on semiconductor composites for hydrogen production under visible light irradiation. After a general introduction about the photocatalysis phenomenon, typical heterojunctions of widely studied heterogeneous semiconductors, including titanium dioxide, cadmium sulfide and graphitic carbon nitride are discussed in detail. PMID:25804291

  6. Sensitivity studies for space-based measurement of atmospheric total column carbon dioxide by reflected sunlight.

    PubMed

    Mao, Jianping; Kawa, S Randolph

    2004-02-01

    The feasibility of making space-based carbon dioxide (CO2) measurements for global and regional carbon-cycle studies is explored. With the proposed detection method, we use absorption of reflected sunlight near 1.58 microm. The results indicate that the small (degrees 1%) changes in CO2 near the Earth's surface are detectable provided that an adequate sensor signal-to-noise ratio and spectral resolution are achievable. Modification of the sunlight path by scattering of aerosols and cirrus clouds could, however, lead to systematic errors in the CO2 column retrieval; therefore ancillary aerosol and cloud data are important to reduce errors. Precise measurement of surface pressure and good knowledge of the atmospheric temperature profile are also required. PMID:14960086

  7. Nanocomposite heterojunctions as sunlight-driven photocatalysts for hydrogen production from water splitting

    NASA Astrophysics Data System (ADS)

    Reza Gholipour, Mohammad; Dinh, Cao-Thang; Béland, François; Do, Trong-On

    2015-04-01

    Hydrogen production via photocatalytic water splitting using sunlight has enormous potential in solving the worldwide energy and environmental crisis. The key challenge in this process is to develop efficient photocatalysts which must satisfy several criteria such as high chemical and photochemical stability, effective charge separation and strong sunlight absorption. The combination of different semiconductors to create composite materials offers a promising way to achieve efficient photocatalysts because doing so can improve the charge separation, light absorption and stability of the photocatalysts. In this review article, we summarized the most recent studies on semiconductor composites for hydrogen production under visible light irradiation. After a general introduction about the photocatalysis phenomenon, typical heterojunctions of widely studied heterogeneous semiconductors, including titanium dioxide, cadmium sulfide and graphitic carbon nitride are discussed in detail.

  8. Sunlight-enhanced calcareous deposition on cathodic stainless steel in natural seawater.

    PubMed

    Eashwar, M; Sathish Kumar, P; Ravishankar, R; Subramanian, G

    2013-01-01

    In replicate series of experiments in natural seawater, one in full darkness and the other in a 1:1 diurnal cycle with as little as ~5% of natural solar illumination, sunlight promoted calcareous deposition on cathodic stainless steel surfaces. As exemplified by scanning electron microscopy, the deposit that formed under the natural diurnal cycle, in the presence of photosynthetic biofilms, was composed of finer calcareous crystals that provided more compact and more uniform surface coverage than the one formed in the dark. The light-enhanced deposit also possessed better scale properties, as suggested by X-ray analysis and electrochemical measurements. Sunlight enhancement of calcareous deposition looked all the more conspicuous when day and night regimes were examined independently. These results not only bear important implications for cathodic protection in marine waters, but also provide an intriguing analogy to coral reef calcification. PMID:23330652

  9. Two Virasoro symmetries in stringy warped AdS3

    NASA Astrophysics Data System (ADS)

    Compère, Geoffrey; Guica, Monica; Rodriguez, Maria J.

    2014-12-01

    We study three-dimensional consistent truncations of type IIB supergravity which admit warped AdS3 solutions. These theories contain subsectors that have no bulk dynamics. We show that the symplectic form for these theories, when restricted to the non-dynamical subsectors, equals the symplectic form for pure Einstein gravity in AdS3. Consequently, for each consistent choice of boundary conditions in AdS3, we can define a consistent phase space in warped AdS3 with identical conserved charges. This way, we easily obtain a Virasoro × Virasoro asymptotic symmetry algebra in warped AdS3; two different types of Virasoro × Kač-Moody symmetries are also consistent alternatives.

  10. Nanoscience at Work: Creating Energy from Sunlight (LBNL Science at the Theater)

    ScienceCinema

    Alivisatos, Paul

    2011-04-28

    Paul Alivisatos, co-leader of Berkeley Lab's Helios Project, is the Associate Director for Physical Sciences and director of the Materials Sciences Division at Berkeley Lab. In the Helios Project, Alivisatos will use nanotechnology in the efficient capture of sunlight and its conversion to electricity to drive economical fuel production processes. He is an authority on artificial nanostructure synthesis and inventor of the quantum dot technology.

  11. Safety and Efficacy of Filtered Sunlight in Treatment of Jaundice in African Neonates

    PubMed Central

    Vreman, Hendrik J.; Olusanya, Bolajoko O.; Wong, Ronald J.; Brearley, Ann M.; Vaucher, Yvonne E.; Stevenson, David K.

    2014-01-01

    OBJECTIVES: Evaluate safety and efficacy of filtered-sunlight phototherapy (FS-PT). METHODS: Term/late preterm infants ≤14 days old with clinically significant jaundice, assessed by total bilirubin (TB) levels, were recruited from a maternity hospital in Lagos, Nigeria. Sunlight was filtered with commercial window-tinting films that remove most UV and significant levels of infrared light and transmit effective levels of therapeutic blue light. After placing infants under an FS-PT canopy, hourly measurements of axillary temperatures, monitoring for sunburn, dehydration, and irradiances of filtered sunlight were performed. Treatment was deemed safe and efficacious if infants were able to stay in FS-PT for ≥5 hours and rate of rise of TB was <0.2 mg/dL/h for infants ≤72 hours of age or TB decreased for infants >72 hours of age. RESULTS: A total of 227 infants received 258 days of FS-PT. No infant developed sunburn or dehydration. On 85 (33%) of 258 treatment days, infants were removed briefly from FS-PT due to minor temperature-related adverse events. No infant met study exit criteria. FS-PT was efficacious in 92% (181/197) of evaluable treatment days. Mean ± SD TB change was –0.06 ± 0.19 mg/dL/h. The mean ± SD (range) irradiance of FS-PT was 38 ± 22 (2–115) µW/cm2/nm, measured by the BiliBlanket Meter II. CONCLUSIONS: With appropriate monitoring, filtered sunlight is a novel, practical, and inexpensive method of PT that potentially offers safe and efficacious treatment strategy for management of neonatal jaundice in tropical countries where conventional PT treatment is not available. PMID:24864170

  12. Photochemical formation of hydrogen peroxide in surface and ground waters exposed to sunlight

    SciTech Connect

    Cooper, W.J.; Zika, R.G.

    1983-05-13

    A rapid increase in the concentration of hydrogen peroxide was observed when samples of natural surface and ground water from various locations in the United States were exposed to sunlight. The hydrogen peroxide is photochemically generated from organic constitutents present in the water; humic materials are believed to be the primary agent producing the peroxide. Studies with superoxide dismutase suggest that the superoxide anion is the precursor of the peroxide.

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

    NASA Technical Reports Server (NTRS)

    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.

  14. Catching Sunlight

    NASA Astrophysics Data System (ADS)

    Friedman, Alan

    Everyone knows that astronomy is done in the dark. Astronomers are creatures of the night, like vampires, sleeping during the day and working all night long to catch the faint light of their elusive prey.

  15. Variability in susceptibility to simulated sunlight of conidia among isolates of entomopathogenic Hyphomycetes.

    PubMed

    Fargues, J; Goettel, M S; Smits, N; Ouedraogo, A; Vidal, C; Lacey, L A; Lomer, C J; Rougier, M

    1996-09-01

    The influence of simulated sunlight on survival of conidia of 4 species of entomopathogenic Hyphomycetes was investigated. Conidia from 65 isolates ofBeauveria bassiana, 23 ofMetarhizium anisopliae, 14 ofMetarhizium flavoviride and 33 isolates ofPaecilomyces fumosoroseus were irradiated by artificial sunlight (295 to 1,100 nm at an ultraviolet-B irradiance of 0.3 W m(-2)) for 0, 1, 2, 4 and 8 h. Survival was estimated by comparing the number of colony forming units (CFU) produced by conidia exposed to irradiation to the number of CFUs produced by an unexposed control. Survival decreased with increased exposure to simulated sunlight; exposure for 2 h or more was detrimental to all isolates tested. Overall, isolates ofM. flavoviride were the most resistant to irradiation followed byB. bassiana andM. anisopliae. Conidia ofP. fumosoroseus were most susceptible. In addition to the large interspecies differences in susceptibility to irradiation, there was also an intraspecies variation indicating that strain selection to irradiation tolerance may be important in the development of microbial control agents where increased persistence in an insolated environment is desirable. PMID:20882453

  16. Photolytic dehalogenation of disinfection byproducts in water by natural sunlight irradiation.

    PubMed

    Abusallout, Ibrahim; Hua, Guanghui

    2016-09-01

    The aqueous photolysis of halogenated disinfection byproducts (DBPs) by natural sunlight irradiation was studied to determine their photolytic dehalogenation kinetics. Total organic halogen analysis was used to quantify the dehalogenation extents of DBPs during outdoor photolysis experiments. Dichloroacetamide, chloral hydrate, chloroform, dichloroacetonitrile, monochloro-, monobromo-, dichloro-, dibromo-, and trichloroacetic acids were generally resistant to photolytic dehalogenation and showed less than 10% reduction after 6 h sunlight irradiation. Monoiodoacetic acid, tribromoacetic acid, bromoform, dibromoacetonitrile, and trichloronitromethane showed moderate to high dehalogenation degrees with half-lives of 4.0-19.3 h. Diiodoacetic acid, triiodoacetic acid, and iodoform degraded rapidly under the sunlight irradiation and exhibited half-lives of 5.3-10.2 min. In general, the photosensitive cleavage of carbon-halogen bonds of DBPs increased with increasing number of halogens (tri- > di- > mono-halogenated) and size of the substituted halogens (I > Br > Cl). Nitrate, nitrite, and pH had little impact on the photodehalogenation of DBPs under typical levels in surface waters. The presence of natural organic matter (NOM) inhibited the photodehalogenation of DBPs by light screening. The NOM inhibiting effects were more pronounced for the fast degrading iodinated DBPs. The results of this study improve our understanding about the photolytic dehalogenation of wastewater-derived DBPs in surface waters during water reuse. PMID:27289205

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

    PubMed

    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. PMID:17547204

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

    PubMed

    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. PMID:26380666

  19. Sunlight penetration through the Martian polar caps: Effects on the thermal and frost budgets

    NASA Technical Reports Server (NTRS)

    Lindner, Bernhard Lee

    1992-01-01

    An energy balance model of the seasonal polar caps on Mars is modified to include penetration of solar radiation into and through the ice. Penetration of solar radiation has no effect on subsurface temperature or total frost sublimation if seasonal ice overlies a dust surface. An effect is noted for seasonal ice which overlies the residual polar caps. For the case of an exposed water-ice residual polar cap, the temperature at depth is calculated to be up to several degrees warmer and the calculated lifetime of seasonal CO2 frost is slightly lower when penetration of sunlight is properly treated in the model. For the case of a residual polar cap which is perennially covered by CO2 frost, the calculated lifetime of seasonal CO2 frost is very slightly increased as a result of sunlight penetration through the ice. Hence, penetration of sunlight into the ice helps to stabilize the observed dichotomy in the residual polar caps on Mars, although it is a small effect.

  20. Sunlight penetration through the Martian polar caps - Effects on the thermal and frost budgets

    NASA Technical Reports Server (NTRS)

    Lindner, Bernhard L.

    1992-01-01

    An energy balance model of the seasonal polar caps on Mars is modified to include penetration of solar radiation into and through the ice. Penetration of solar radiation has no effect on subsurface temperature or total frost sublimation if seasonal ice overlies a dust surface. An effect is noted for seasonal ice which overlies the residual polar caps. For the case of an exposed water-ice residual polar cap, the temperature at depth is calculated to be up to several degrees warmer, and the calculated lifetime of seasonal CO2 frost is slightly lower when penetration of sunlight is properly treated in the model. For the case of a residual polar cap which is perennially covered by CO2 frost, the calculated lifetime of seasonal CO2 frost is very slightly increased as a result of sunlight penetration through the ice. Hence, penetration of sunlight into the ice helps to stabilize the observed dichotomy in the residual polar caps on Mars, although it is a small effect.

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

    PubMed Central

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

    2015-01-01

    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. PMID:26380666

  2. Worst case earth charging environment. [geosynchronous plasma environment in sunlight for predicting spacecraft potential in eclipse

    NASA Technical Reports Server (NTRS)

    Deutsch, M.-J. C.

    1982-01-01

    The Applications Technology Satellite-6 (ATS-6) geosynchronous satellite charged up to -2200 V in sunlight on day 178, 1974. This event, being the highest known spacecraft charging event in sunlight, is used to estimate a worst case geosynchronous plasma environment for predicting the spacecraft potential in eclipse. The advantage of using this sunlight spectrum as opposed to an eclipse case is that the ion and electron fluxes to the detectors are shifted only slightly due to the spacecraft potential. After correcting the available data for satellite potential and missing data above 81 KeV, it is found that the plasma can be characterized by a single Maxwellian approximation having an electron density of 1.22/cu cm, electron temperature of 16 KeV, hydrogen ion density of 0.24/cu cm, and hydrogen ion temperature of 29 KeV. In eclipse the spacecraft would have charged up to -28 kV, the highest estimated potential to date in the earth's plasma environment.

  3. Carcinogenic effect of sequential artificial sunlight and UV-A irradiation in hairless mice. Consequences for solarium 'therapy'.

    PubMed

    Staberg, B; Wulf, H C; Poulsen, T; Klemp, P; Brodthagen, H

    1983-08-01

    The carcinogenic effect of artificial UV sunlight followed by UV-A irradiation in human solaria doses has been studied with the use of the hairless mouse as an animal model. Artificial sunlight exposure alone induced only a moderate skin tumor incidence (animals with at least one tumor) of 0.15 after one year, and UV-A irradiation alone induced no tumor formation. However, the combination of artificial sunlight exposure and subsequent UV-A irradiation significantly increased the tumor incidence to 0.72. We conclude that, in humans, tanning with UV-A for cosmetic purposes may not be an innocuous procedure. PMID:6870317

  4. Deflection of Hazardous Near-Earth Objects by High Concentrated Sunlight and Adequate Design of Optical Collector

    NASA Astrophysics Data System (ADS)

    Vasylyev, V. P.

    2013-02-01

    Some detailed astronomical and applied aspects deflection of hazardous near-Earth objects (NEO) by direct high concentrated sunlight, causing intensive local ablation of their surfaces, are considered. The major requirements to solar concentrating optics within a single collector (a large mirror) approach, along with the asteroid properties being most substantial in achieving the predetermined effect for the period less than a year (mid-thrust action), are discussed. Such a hastened strategy may become topical in the case of late detection of potential danger, and also, if required, in providing the possibility for some additional action. It is also more acceptable in the public perception and keeping the peace for mankind rather than a long-run expectation of the incorrigible deflection resulting shortly ahead of the predicted hazard. The conventional concave reflectors have been graved to be practically inapplicable within the high concentrating geometry. This is primarily because of the dramatic spread of their focal spots at needful inclinations of optical axis from the direction toward the Sun, as well as of problematic use of the secondary optics. An alternative design of a mirrored ring-array collector is presented (as a tested and approved point-focus version of innovative reflective lenses for sunlight concentration within this approach), and comparative analysis was made. The assessment argues in favor of such a type of high-aperture optics having more capabilities than conventional devices. Mainly, this is because of the underside position (as respects the entrance aperture) of its focal area that allows avoidance of target shadowing the reflecting surfaces and minimizes their coating by the ejected debris. By using the modern asteroids database, some key estimations have been obtained. The surface irradiance around 4-5 MW/m2 (average across the focal spot concentration level ~5 × 103) for the ring-array collector size ~0.5 of asteroid diameter might

  5. Leading Change, Adding Value.

    PubMed

    Evans, Nick

    2016-09-12

    Essential facts Leading Change, Adding Value is NHS England's new nursing and midwifery framework. It is designed to build on Compassion in Practice (CiP), which was published 3 years ago and set out the 6Cs: compassion, care, commitment, courage, competence and communication. CiP established the values at the heart of nursing and midwifery, while the new framework sets out how staff can help transform the health and care sectors to meet the aims of the NHS England's Five Year Forward View. PMID:27615573

  6. Relevance of sunscreen application method, visible light and sunlight intensity to free-radical protection: A study of ex vivo human skin.

    PubMed

    Haywood, Rachel

    2006-01-01

    With the continued rise in skin cancers worldwide there is a need for effective skin protection against sunlight damage. It was shown previously that sunscreens, which claimed UVA protection (SPF 20+), provided limited protection against UV-induced ascorbate radicals in human skin. Here the results of an electron spin resonance (ESR) investigation to irradiate ex vivo human skin with solar-simulated light are reported. The ascorbate radical signal in the majority of skin samples was directly proportional to the irradiance over relevant sunlight intensities (0.9-2.9 mW cm(-2)). Radical production (substratum-corneum) by UV (wavelengths < 400 nm) and visible components (> 400 nm) was approximately 67% and 33% respectively. Ascorbate radicals were in steady state concentration at low irradiance (approximately 1 mW cm(-2) equivalent to UK sunlight), but at higher irradiance (approximately 3 mW cm(-2)) decreased with time, suggesting ascorbate depletion. Radical protection by a four star-rated sunscreen (with UVA protection) was optimal when applied as a thin film (40-60% at 2 mg cm(-2)) but less so when rubbed into the skin (37% at 4 mg cm(-2) and no significant protection at 2 mg cm(-2)), possibly due to cream filling crevices, which reduced film thickness. This study validates ESR determinations of the ascorbate radical for quantitative protection measurements. Visible light contribution to radical production, and loss of protection when sunscreen is rubbed into skin, has implications for sunscreen design and use for the prevention of free-radical damage. PMID:17205635

  7. Induction of metallothionein in human skin by routine exposure to sunlight: evidence for a systemic response and enhanced induction at certain body sites.

    PubMed

    Ablett, Effie; Whiteman, David C; Boyle, Glen M; Green, Adèle C; Parsons, Peter G

    2003-02-01

    Expression of metallothionein, an antioxidant induced by a variety of stimuli including ultraviolet light, was quantitated by immunohistochemistry in the skin of males aged over 50 who had known short- and long-term exposures to sunlight. Skin punch biopsies were taken from two sites in each subject: the hand in all subjects and a range of other sites matched to patients with a previously excised primary melanoma. Metallothionein expression (strongest in the basal layers of the epidermis and primarily nuclear) was associated with both short- and long-term exposure to sunlight. A plateau of staining intensity was reached after 3 h sun exposure, within the previous 3 d before biopsy. Expression was also elevated in the nonexposed skin sites of subjects who had recent sun exposure, indicating a systemic response to exposure of remote sites. Using the skin of the hand to normalize responses to chronic exposure between individuals, the systemically modulated response to sunlight was significantly greater on the unexposed back than on other sites. The possibility of ultraviolet-induced cytokines selectively modifying the response of skin on a site-specific basis was investigated. The circulating leukocytes, but not lymphocytes, of two individuals exposed to 1 minimal erythema dose whole-body solar-simulated ultraviolet showed increased interleukin-6 mRNA 4 h after exposure. Interleukin-6 was not directly induced in these cell populations 4 h after ultraviolet A or ultraviolet B irradiation ex vivo. Leukocytes may therefore contribute to and amplify the systemic effects of ultraviolet-induced interleukin-6 and metallothionein expression. PMID:12542539

  8. A guide to gauging ad effectiveness.

    PubMed

    Cashill, J

    1987-09-01

    Techniques that have proven successful in private industry can help hospital executives increase their accountability for advertising expenditures. Among these techniques are: The random telephone survey, which can be used to measure whether the hospital's awareness level among the public has increased as the result of a particular ad; The focus group, which assists the hospital in evaluating how it is perceived in relation to other hospitals in its market; The pretest, to determine which ads to eliminate from a campaign and which ones to refine; Educational seminars and direct-response ads; Reliable baseline data on patients and services for use in comparing figures before and after an ad has been used. Above all, careful planning is required to enable the marketing staff to determine what it wishes to accomplish through advertising and to set measurable goals that reflect its expectations for each component of a campaign. PMID:10283482

  9. An xp model on AdS2 spacetime

    NASA Astrophysics Data System (ADS)

    Molina-Vilaplana, Javier; Sierra, Germán

    2013-12-01

    In this paper we formulate the xp model on the AdS2 spacetime. We find that the spectrum of the Hamiltonian has positive and negative eigenvalues, whose absolute values are given by a harmonic oscillator spectrum, which in turn coincides with that of a massive Dirac fermion in AdS2. We extend this result to generic xp models which are shown to be equivalent to a massive Dirac fermion on spacetimes whose metric depend of the xp Hamiltonian. Finally, we construct the generators of the isometry group SO(2,1) of the AdS2 spacetime, and discuss the relation with conformal quantum mechanics.

  10. Dirac operator on fuzzy AdS2

    NASA Astrophysics Data System (ADS)

    Fakhri, Hossein; Imaanpur, Ali

    2003-03-01

    In this article we construct the chirality and Dirac operators on noncommutative AdS2. We also derive the discrete spectrum of the Dirac operator which is important in the study of the spectral triple associated to AdS2. It is shown that the degeneracy of the spectrum present in the commutative AdS2 is lifted in the noncommutative case. The way we construct the chirality operator is suggestive of how to introduce the projector operators of the corresponding projective modules on this space.