WorldWideScience

Sample records for direct solar radiation

  1. Estimating hourly direct and diffuse solar radiation for the compilation of solar radiation distribution maps

    International Nuclear Information System (INIS)

    Ueyama, H.

    2005-01-01

    This paper presents a new method for estimating hourly direct and diffuse solar radiation. The essence of the method is the estimation of two important factors related to solar radiation, atmospheric transmittance and a dimensionless parameter, using empirical and physical equations and data from general meteorological observation stations. An equation for atmospheric transmittance of direct solar radiation and a dimensionless parameter representing diffuse solar radiation are developed. The equation is based on multiple regression analysis and uses three parameters as explanatory variates: calculated hourly extraterrestrial solar radiation on a horizontal plane, observed hourly sunshine duration and hourly precipitation as observed at a local meteorological observatory. The dimensionless parameter for estimating a diffuse solar radiation is then determined by linear least squares using observed hourly solar radiation at a local meteorological observatory. The estimated root mean square error (RMSE) of hourly direct and diffuse solar radiation is about 0.0-0.2 MJ¥m(-2)¥h(-1) in each mean period. The RMSE of the ten-day and monthly means of these quantities is about 0.0-0.2 MJ¥m(-2)¥h(-1), based on comparisons with AMeDAS station data, located at a distance of 6 km

  2. Correlation of total, diffuse, and direct solar radiation

    Science.gov (United States)

    Buyco, E. H.; Namkoong, D.

    1977-01-01

    Present requirements for realistic solar energy system evaluations necessitate a comprehensive body of solar-radition data. The data should include both diffuse and direct solar radiation as well as their total on an hourly (or shorter) basis. In general, however, only the total solar radiation values were recorded. This report presents a correlation that relates the diffuse component of an hourly total solar radiation value to the total radiation ratio of the maximum value attainable. The data used were taken at the Blue Hill Observatory in Milton, Massachusetts, for the period 1952. The relation - in the form of the data plots - can be used in situations in which only the hourly total radiation data are available but the diffuse component is desired.

  3. Leaf color is fine-tuned on the solar spectra to avoid strand direct solar radiation.

    Science.gov (United States)

    Kume, Atsushi; Akitsu, Tomoko; Nasahara, Kenlo Nishida

    2016-07-01

    The spectral distributions of light absorption rates by intact leaves are notably different from the incident solar radiation spectra, for reasons that remain elusive. Incident global radiation comprises two main components; direct radiation from the direction of the sun, and diffuse radiation, which is sunlight scattered by molecules, aerosols and clouds. Both irradiance and photon flux density spectra differ between direct and diffuse radiation in their magnitude and profile. However, most research has assumed that the spectra of photosynthetically active radiation (PAR) can be averaged, without considering the radiation classes. We used paired spectroradiometers to sample direct and diffuse solar radiation, and obtained relationships between the PAR spectra and the absorption spectra of photosynthetic pigments and organs. As monomers in solvent, the spectral absorbance of Chl a decreased with the increased spectral irradiance (W m(-2) nm(-1)) of global PAR at noon (R(2) = 0.76), and was suitable to avoid strong spectral irradiance (λmax = 480 nm) rather than absorb photon flux density (μmol m(-2) s(-1) nm(-1)) efficiently. The spectral absorption of photosystems and the intact thallus and leaves decreased linearly with the increased spectral irradiance of direct PAR at noon (I dir-max), where the wavelength was within the 450-650 nm range (R(2) = 0.81). The higher-order structure of photosystems systematically avoided the strong spectral irradiance of I dir-max. However, when whole leaves were considered, leaf anatomical structure and light scattering in leaf tissues made the leaves grey bodies for PAR and enabled high PAR use efficiency. Terrestrial green plants are fine-tuned to spectral dynamics of incident solar radiation and PAR absorption is increased in various structural hierarchies.

  4. Human projected area factors for detailed direct and diffuse solar radiation analysis

    DEFF Research Database (Denmark)

    Kubaha, K.; Fiala, D.; Toftum, Jørn

    2004-01-01

    Projected area factors for individual segments of the standing and sedentary human body were modelled for both direct and diffuse solar radiation using detailed 3D geometry and radiation models. The local projected area factors with respect to direct short-wave radiation are a function of the solar...

  5. Studies of diffuse and direct solar radiation over snow

    International Nuclear Information System (INIS)

    Wesely, M.L.; Everett, R.G.

    1976-01-01

    Two interesting questions can be addressed by examination of solar radiation records obtained while the surface is covered with snow. One concerns the extent to which airborne particulate matter affects solar radiation received at the surface during winter conditions that are typical of those in the northeastern quarter of the United States. The other relates to the importance of complicated light scatterng in the earth-atmosphere system when the surface albedo is large. With the snow surface reflecting 50% or more of the incident radiation, it is likely that a significant addition to diffuse radiation would result from light that is reflected from the surface and then scattered back to the earth by the atmosphere. Preliminary data from measurements made during the winter of 1975 to 1976 are reported

  6. Solar radiation and cooling load calculation for radiant systems: Definition and evaluation of the Direct Solar Load

    DEFF Research Database (Denmark)

    Causone, Francesco; Corgnati, Stefano P.; Filippi, Marco

    2010-01-01

    The study of the influence of solar radiation on the built environment is a basic issue in building physics and currently it is extremely important because glazed envelopes are widely used in contemporary architecture. In the present study, the removal of solar heat gains by radiant cooling systems...... is investigated. Particular attention is given to the portion of solar radiation converted to cooling load, without taking part in thermal absorption phenomena due to the thermal mass of the room. This specific component of the cooling load is defined as the Direct Solar Load. A simplified procedure to correctly...... calculate the magnitude of the Direct Solar Load in cooling load calculations is proposed and it is implemented with the Heat Balance method and the Radiant Time Series method. The F ratio of the solar heat gains directly converted to cooling load, in the case of a low thermal mass radiant ceiling...

  7. Direct solar radiation on various slopes from 0 to 60 degrees north latitude.

    Science.gov (United States)

    John Buffo; Leo J. Fritschen; James L. Murphy

    1972-01-01

    Direct beam solar radiation is presented in graphical and tabular form for hourly, daily, and yearly values for seven slopes on each of 16 aspects from the Equator to 60 degrees north in 10-degree increments. Theoretical equations necessary for the calculations are given. Solar altitude and azimuth during the day and year are also presented for the same latitude.

  8. Sensitivity analysis of numerical weather prediction radiative schemes to forecast direct solar radiation over Australia

    Science.gov (United States)

    Mukkavilli, S. K.; Kay, M. J.; Taylor, R.; Prasad, A. A.; Troccoli, A.

    2014-12-01

    The Australian Solar Energy Forecasting System (ASEFS) project requires forecasting timeframes which range from nowcasting to long-term forecasts (minutes to two years). As concentrating solar power (CSP) plant operators are one of the key stakeholders in the national energy market, research and development enhancements for direct normal irradiance (DNI) forecasts is a major subtask. This project involves comparing different radiative scheme codes to improve day ahead DNI forecasts on the national supercomputing infrastructure running mesoscale simulations on NOAA's Weather Research & Forecast (WRF) model. ASEFS also requires aerosol data fusion for improving accurate representation of spatio-temporally variable atmospheric aerosols to reduce DNI bias error in clear sky conditions over southern Queensland & New South Wales where solar power is vulnerable to uncertainities from frequent aerosol radiative events such as bush fires and desert dust. Initial results from thirteen years of Bureau of Meteorology's (BOM) deseasonalised DNI and MODIS NASA-Terra aerosol optical depth (AOD) anomalies demonstrated strong negative correlations in north and southeast Australia along with strong variability in AOD (~0.03-0.05). Radiative transfer schemes, DNI and AOD anomaly correlations will be discussed for the population and transmission grid centric regions where current and planned CSP plants dispatch electricity to capture peak prices in the market. Aerosol and solar irradiance datasets include satellite and ground based assimilations from the national BOM, regional aerosol researchers and agencies. The presentation will provide an overview of this ASEFS project task on WRF and results to date. The overall goal of this ASEFS subtask is to develop a hybrid numerical weather prediction (NWP) and statistical/machine learning multi-model ensemble strategy that meets future operational requirements of CSP plant operators.

  9. Calculation and mapping of direct and diffuse solar radiation in Costa Rica

    International Nuclear Information System (INIS)

    Wright, Jaime

    2008-01-01

    Knowledge of direct and diffuse solar radiation has been of vital importance in assessing the energy potential of Costa Rica. The work is focused on the calculation and plotting of contour maps of the direct and diffuse solar radiation, based in sixty-two radiometric stations scattered throughout the country. In tracing these contours have been used experimental and predicted values of direct and diffuse radiation. Additionally, direct and diffuse solar radiation is compared during the dry season and the rainy season in the six climatic regions of the country: Valle Central, North Pacific, Central Pacific, South Pacific, North Zone and Caribbean Region. Daily average levels of radiation observed directly have been from 6.1 and 10.1 MJ/m 2 , with higher values in the northern sections of the Pacific Slope, west of Valle Central and the tops of the highest mountains. The lowest values have coincided with the North Zone and Caribbean Region. The highest values of diffuse radiation have coincided with the North Zone and South Pacific. An increase in direct solar radiation by 40% is observed in the month of the dry season. (author) [es

  10. Passive-solar directional-radiating cooling system

    Science.gov (United States)

    Hull, J.R.; Schertz, W.W.

    1985-06-27

    A radiative cooling system for use with an ice-making system having a radiating surface aimed at the sky for radiating energy at one or more wavelength bands for which the atmosphere is transparent and a cover thermally isolated from the radiating surface and transparent at least to the selected wavelength or wavelengths, the thermal isolation reducing the formation of condensation on the radiating surface and/or cover and permitting the radiation to continue when the radiating surface is below the dewpoint of the atmosphere, and a housing supporting the radiating surface, cover and heat transfer means to an ice storage reservoir.

  11. Medium level of direct solar radiation and energetic potential of solar concentrator in Minas Gerais State, Brazil; Niveis medios de radiacao solar direta e potencial energetico dos concentradores solares em Minas Gerais

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1991-07-01

    Basic concepts of solar energy, technical description of solar concentrators, its orientation and methodology of direct solar radiation measurement are discussed. An comparison of different solar radiation measurements methods, its methodology and its calculation steps are reported. Calculus and tables of the electric and thermal energy generation potential, through solar concentrators, on the state of Minas Gerais are also presented. 18 figs., 90 tabs., 12 refs.

  12. Measuring Air Temperature in Glazed Ventilated Facades in the Presence of Direct Solar Radiation

    DEFF Research Database (Denmark)

    Kalyanova, Olena; Zanghirella, Fabio; Heiselberg, Per

    2007-01-01

    A distinctive element of buildings with a double glazed façade is naturally or mechanically driven flow in a ventilated cavity. Accurate air temperature measurements in the cavity are crucial to evaluate the dynamic performance of the façade, to predict and control its behavior as a significant...... part of the complete ventilation system. Assessment of necessary cooling/heating loads and of the whole building energy performance will then depend on the accuracy of measured air temperature. The presence of direct solar radiation is an essential element for the façade operation, but it can heavily...... affect measurements of air temperature and may lead to errors of high magnitude using bare thermocouples and even adopting shielding devices. Two different research groups, from Aalborg University and Politecnico di Torino, tested separately various techniques to shield thermocouples from direct...

  13. Direct solar-pumped lasers

    Science.gov (United States)

    Lee, J. H.; Shiu, Y. J.; Weaver, W. R.

    1980-01-01

    The feasibility of direct solar pumping of an iodine photodissociation laser at lambda = 1.315 microns was investigated. Threshold inversion density and effect of elevated temperature (up to 670 K) on the laser output were measured. These results and the concentration of solar radiation required for the solar pumped iodine laser are discussed.

  14. The direct effect of aerosols on solar radiation over the broader Mediterranean basin

    Directory of Open Access Journals (Sweden)

    C. D. Papadimas

    2012-08-01

    Full Text Available For the first time, the direct radiative effect (DRE of aerosols on solar radiation is computed over the entire Mediterranean basin, one of the most climatically sensitive world regions, using a deterministic spectral radiation transfer model (RTM. The DRE effects on the outgoing shortwave radiation at the top of atmosphere (TOA, DRETOA, on the absorption of solar radiation in the atmospheric column, DREatm, and on the downward and absorbed surface solar radiation (SSR, DREsurf and DREnetsurf, respectively, are computed separately. The model uses input data for the period 2000–2007 for various surface and atmospheric parameters, taken from satellite (International Satellite Cloud Climatology Project, ISCCP-D2, Global Reanalysis projects (National Centers for Environmental Prediction – National Center for Atmospheric Research, NCEP/NCAR, and other global databases. The spectral aerosol optical properties (aerosol optical depth, AOD, asymmetry parameter, gaer and single scattering albedo, ωaer, are taken from the MODerate resolution Imaging Spectroradiometer (MODIS of NASA (National Aeronautics and Space Administration and they are supplemented by the Global Aerosol Data Set (GADS. The model SSR fluxes have been successfully validated against measurements from 80 surface stations of the Global Energy Balance Archive (GEBA covering the period 2000–2007.

    A planetary cooling is found above the Mediterranean on an annual basis (regional mean DRETOA = −2.4 W m−2. Although a planetary cooling is found over most of the region, of up to −7 W m−2, large positive DRETOA values (up to +25 W m−2 are found over North Africa, indicating a strong planetary warming, and a weaker warming over the Alps (+0.5 W m−2. Aerosols are found to increase the absorption of solar radiation in the atmospheric

  15. Satellite orbits perturbed by direct solar radiation pressure: general expansion of the disturbing function

    International Nuclear Information System (INIS)

    Hughes, S.

    1977-01-01

    An expression is derived for the solar radiation pressure disturbing function on an Earth satellite orbit which takes into account the variation of the solar radiation flux with distance from the Sun's centre and the absorption of radiation by the satellite. This expression is then expanded in terms of the Keplerian elements of the satellite and solar orbits using Kaula's method (Astr. J.; 67:300 (1962)). The Kaula inclination functions are replaced by an equivalent set of modified Allan (Proc. R. Soc. A.; 288:60 (1965)) inclination functions. The resulting expression reduces to the form commonly used in solar radiation pressure perturbation studies (e.g. Aksnes, Cel. Mech.; 13:89 (1976)), when certain terms are neglected. If, as happens quite often in practice, a satellite's orbit is in near-resonance with certain of these neglected terms, these near-resonant terms can cause changes in the satellite's orbital elements comparable to those produced by the largest term in Aksnes's expression. A new expression for the solar radiation pressure disturbing function expansion is suggested for use in future studies of satellite orbits perturbed by solar radiation pressure. (author)

  16. Parameterization models for solar radiation and solar technology applications

    International Nuclear Information System (INIS)

    Khalil, Samy A.

    2008-01-01

    Solar radiation is very important for the evaluation and wide use of solar renewable energy systems. The development of calibration procedures for broadband solar radiation photometric instrumentation and the improvement of broadband solar radiation measurement accuracy have been done. An improved diffuse sky reference and photometric calibration and characterization software for outdoor pyranometer calibrations are outlined. Parameterizations for direct beam, total hemispherical and diffuse sky radiation and solar radiation technology are briefly reviewed. The uncertainties for various broadband solar radiations of solar energy and atmospheric effects are discussed. The varying responsivities of solar radiation with meteorological, statistical and climatological parameters and possibility atmospheric conditions was examined

  17. Parameterization models for solar radiation and solar technology applications

    Energy Technology Data Exchange (ETDEWEB)

    Khalil, Samy A. [National Research Institute of Astronomy and Geophysics, Solar and Space Department, Marsed Street, Helwan, 11421 Cairo (Egypt)

    2008-08-15

    Solar radiation is very important for the evaluation and wide use of solar renewable energy systems. The development of calibration procedures for broadband solar radiation photometric instrumentation and the improvement of broadband solar radiation measurement accuracy have been done. An improved diffuse sky reference and photometric calibration and characterization software for outdoor pyranometer calibrations are outlined. Parameterizations for direct beam, total hemispherical and diffuse sky radiation and solar radiation technology are briefly reviewed. The uncertainties for various broadband solar radiations of solar energy and atmospheric effects are discussed. The varying responsivities of solar radiation with meteorological, statistical and climatological parameters and possibility atmospheric conditions was examined. (author)

  18. Extinction of direct solar radiation in Puławy in the years 1969–1989

    International Nuclear Information System (INIS)

    Uscka-Kowalkowska, J.

    2007-01-01

    The paper presents the problem of attenuation of the direct solar radiation in Puławy in the years 1969–1989. The extinction was expressed with the help of the Linke’s turbidity factor counted on the basis of measurements of the direct solar irradiance at the Institute of Soil Science and Plant Cultivation in the years 1969–1989. The turbidity factor was counted and reduced to 2 optical mass of the atmosphere according to the method proposed by Grenier et al. (6). The mean value of the turbidity factor for the atmosphere in the study period was in the class of raised turbidity and equalled 3.41. However, an improvement was noted in the optical conditions of the atmosphere expressed by the decrease of the value of Linke’s turbidity factor during the whole study period. The annual course of the turbidity is typical, i.e. it increases in the warm half-year and decreases in the cold half-year. In the daily course, the mean turbidity of the atmosphere increases with the altitude of the Sun above the horizon. The atmospheric turbidity also depends on the kind of the air masses present. During the study period in Puławy, the lowest value of the atmospheric turbidity occurred in the case of arctic air masses (2.79), while the highest in tropical air (4.05). Polar-continental and polar-maritime air masses are characterised by similar turbidity level of the atmosphere, 3.44 and 3.50, respectively. (author) [pl

  19. Global, direct and diffuse solar radiation on horizontal and tilted surfaces in Jeddah, Saudi Arabia

    International Nuclear Information System (INIS)

    El-Sebaii, A.A.; Al-Hazmi, F.S.; Al-Ghamdi, A.A.; Yaghmour, S.J.

    2010-01-01

    The measured data of global and diffuse solar radiation on a horizontal surface, the number of bright sunshine hours, mean daily ambient temperature, maximum and minimum ambient temperatures, relative humidity and amount of cloud cover for Jeddah (lat. 21 o 42'37''N, long. 39 o 11'12''E), Saudi Arabia, during the period (1996-2007) are analyzed. The monthly averages of daily values for these meteorological variables have been calculated. The data are then divided into two sets. The sub-data set I (1996-2004) are employed to develop empirical correlations between the monthly average of daily global solar radiation fraction (H/H 0 ) and the various weather parameters. The sub-data set II (2005-2007) are then used to evaluate the derived correlations. Furthermore, the total solar radiation on horizontal surfaces is separated into the beam and diffuses components. Empirical correlations for estimating the diffuse solar radiation incident on horizontal surfaces have been proposed. The total solar radiation incident on a tilted surface facing south H t with different tilt angles is then calculated using both Liu and Jordan isotropic model and Klucher's anisotropic model. It is inferred that the isotropic model is able to estimate H t more accurate than the anisotropic one. At the optimum tilt angle, the maximum value of H t is obtained as ∼36 (MJ/m 2 day) during January. Comparisons with 22 years average data of NASA SSE Model showed that the proposed correlations are able to predict the total annual energy on horizontal and tilted surfaces in Jeddah with a reasonable accuracy. It is also found that at Jeddah, the solar energy devices have to be tilted to face south with a tilt angle equals the latitude of the place in order to achieve the best performance all year round.

  20. Experimental analysis of a direct expansion solar assisted heat pump with integral storage tank for domestic water heating under zero solar radiation conditions

    International Nuclear Information System (INIS)

    Fernández-Seara, José; Piñeiro, Carolina; Alberto Dopazo, J.; Fernandes, F.; Sousa, Paulo X.B.

    2012-01-01

    Highlights: ► We analyze a direct expansion solar assisted heat pump under zero solar radiation. ► We determine the COP and equivalent seasonal performance factors (SPFe). ► We determine the main components’ performance under transient operating conditions. ► The Huang and Lee performance evaluation method provides a characteristic COP of 3.23. - Abstract: This paper deals with the experimental evaluation of the performance of a direct expansion solar assisted heat pump water heating (DX-SAHPWH) system working under zero solar radiation conditions at static heating operation mode of the storage tank. The DX-SAHPWH system includes two bare solar collectors as evaporator, a R134a rotary-type hermetic compressor, a thermostatic expansion valve and a helical coil condenser immersed in a 300 L water storage tank. The zero solar radiation and stable ambient air temperature working conditions were established by placing the solar collectors into a climate chamber. The analysis is based on experimental data taken from the DX-SAHPWH provided by the manufacturer and equipped with an appropriate data acquisition system. In the paper, the experimental facility, the data acquisition system and the experimental methodology are described. Performance parameters to evaluate the energy efficiency, such as COP and equivalent seasonal performance factors (SPFe) for the heating period, and the water thermal stratification in the storage tank are defined and obtained from the experimental data. Results from the experimental analysis under transient operating working conditions of the DX-SAHPWH system and its main components are shown and discussed. Lastly, the Huang and Lee DX-SAHPWH performance evaluation method was applied resulting in a characteristic COP of 3.23 for the DX-SAHPWH system evaluated under zero solar radiation condition.

  1. A Nonlinear Autoregressive Exogenous (NARX Neural Network Model for the Prediction of the Daily Direct Solar Radiation

    Directory of Open Access Journals (Sweden)

    Zina Boussaada

    2018-03-01

    Full Text Available The solar photovoltaic (PV energy has an important place among the renewable energy sources. Therefore, several researchers have been interested by its modelling and its prediction, in order to improve the management of the electrical systems which include PV arrays. Among the existing techniques, artificial neural networks have proved their performance in the prediction of the solar radiation. However, the existing neural network models don’t satisfy the requirements of certain specific situations such as the one analyzed in this paper. The aim of this research work is to supply, with electricity, a race sailboat using exclusively renewable sources. The developed solution predicts the direct solar radiation on a horizontal surface. For that, a Nonlinear Autoregressive Exogenous (NARX neural network is used. All the specific conditions of the sailboat operation are taken into account. The results show that the best prediction performance is obtained when the training phase of the neural network is performed periodically.

  2. Aerosol direct effect on solar radiation over the eastern Mediterranean Sea based on AVHRR satellite measurements

    Science.gov (United States)

    Georgakaki, Paraskevi; Papadimas, Christos D.; Hatzianastassiou, Nikos; Fotiadi, Aggeliki; Matsoukas, Christos; Stackhouse, Paul; Kanakidou, Maria; Vardavas, Ilias M.

    2017-04-01

    Despite the improved scientific understanding of the direct effect of aerosols on solar radiation (direct radiative effect, DRE) improvements are necessary, for example regarding the accuracy of the magnitude of estimated DREs and their spatial and temporal variability. This variability cannot be ensured by in-situ surface and airborne measurements, while it is also relatively difficult to capture through satellite observations. This becomes even more difficult when complete spatial coverage of extended areas is required, especially concerning areas that host various aerosol types with variable physico-chemical and optical aerosol properties. Better assessments of aerosol DREs are necessary, relying on aerosol optical properties with high spatial and temporal variation. The present study aims to provide a refined, along these lines, assessment of aerosol DREs over the eastern Mediterranean (EM) Sea, which is a key area for aerosol studies. Daily DREs are computed for 1˚ x1˚ latitude-longitude grids with the FORTH detailed spectral radiation transfer model (RTM) using input data for various atmospheric and surface parameters, such as clouds, water vapor, ozone and surface albedo, taken from the NASA-Langley Global Earth Observing System (GEOS) database. The model spectral aerosol optical depth (AOD), single scattering albedo and asymmetry parameter are taken from the Global Aerosol Data Set and the NOAA Climate Data Record (CDR) version 2 of Advanced Very High resolution Radiometer (AVHRR) AOD dataset which is available over oceans at 0.63 microns and at 0.1˚ x0.1˚ . The aerosol DREs are computed at the surface, the top-of-atmosphere and within the atmosphere, over the period 1985-1995. Preliminary model results for the period 1990-1993 reveal a significant spatial and temporal variability of DREs over the EM Sea, for example larger values over the Aegean and Black Seas, surrounded by land areas with significant anthropogenic aerosol sources, and over the

  3. Advancing Solar Irradiance Measurement for Climate-Related Studies: Accurate Constraint on Direct Aerosol Radiative Effect (DARE)

    Science.gov (United States)

    Tsay, Si-Chee; Ji, Q. Jack

    2011-01-01

    Earth's climate is driven primarily by solar radiation. As summarized in various IPCC reports, the global average of radiative forcing for different agents and mechanisms, such as aerosols or CO2 doubling, is in the range of a few W/sq m. However, when solar irradiance is measured by broadband radiometers, such as the fleet of Eppley Precision Solar Pyranometers (PSP) and equivalent instrumentation employed worldwide, the measurement uncertainty is larger than 2% (e.g., WMO specification of pyranometer, 2008). Thus, out of the approx. 184 W/sq m (approx.263 W/sq m if cloud-free) surface solar insolation (Trenberth et al. 2009), the measurement uncertainty is greater than +/-3.6 W/sq m, overwhelming the climate change signals. To discern these signals, less than a 1 % measurement uncertainty is required and is currently achievable only by means of a newly developed methodology employing a modified PSP-like pyranometer and an updated calibration equation to account for its thermal effects (li and Tsay, 2010). In this talk, we will show that some auxiliary measurements, such as those from a collocated pyrgeometer or air temperature sensors, can help correct historical datasets. Additionally, we will also demonstrate that a pyrheliometer is not free of the thermal effect; therefore, comparing to a high cost yet still not thermal-effect-free "direct + diffuse" approach in measuring surface solar irradiance, our new method is more economical, and more likely to be suitable for correcting a wide variety of historical datasets. Modeling simulations will be presented that a corrected solar irradiance measurement has a significant impact on aerosol forcing, and thus plays an important role in climate studies.

  4. Use of a solar panel as a directionally sensitive large-area radiation monitor for direct and scattered x-rays and gamma-rays.

    Science.gov (United States)

    Abdul-Majid, S

    1987-01-01

    The characteristics of a 25.4 X 91 cm solar cell panel used as an x-ray and gamma-ray radiation monitor are presented. Applications for monitoring the primary x-ray beam are described at different values of operating currents and voltages as well as for directional dependence of scattered radiation. Other applications in gamma-ray radiography are also given. The detector showed linear response to both x-ray and gamma-ray exposures. The equipment is rigid, easy to use, relatively inexpensive and requires no power supply or any complex electronic equipment.

  5. Solar radiation over India

    Energy Technology Data Exchange (ETDEWEB)

    Mani, A; Rangarajan, S

    1982-01-01

    Solar radiation data, on horizontal and sloped surfaces, are provided derived from other meteorological parameters at 145 stations covering all major climatic zones of the country. Two methods were used to compute solar radiation, one using regression techniques to derive radiation from sunshine and cloudiness, the other from extra-terrestrial radiation, allowing for its depletion by absorption and scattering in the atmosphere. The methods of calculating the daily global radiation tilt factor using an anisotropic model for diffuse solar radiation are described. The results of statistical analysis of global solar radiation data recorded at 16 stations are presented. Appendices contain an extensive bibliograpny, sun path diagrams for latitudes 6/sup 0/N to 36/sup 0/N, and tables for the calculation of Local Apparent Time from Indian Standard Time.

  6. Lyman-alpha detector designed for rocket measurements of the direct solar radiation at 121.5 nm

    International Nuclear Information System (INIS)

    Guineva, V.; Tashev, V.; Witt, G.; Gumbel, J.; Khaplanov, M.

    2007-01-01

    Rocket measurements of the direct Lyman-alpha radiation penetrating in the atmosphere were planned during the HotPay I rocket experiment, June 2006, Project ASLAF (Attenuation of the Solar Lyman-Alpha Flux), Andoya Rocket Range (ARR), Norway. The basic goal of ASLAF project was the study of the processes in the summer mesosphere and thermosphere (up to 110 km), at high latitudes using the Lyman-alpha measurements. The resonance transition 2 P- 2 S of the atomic hydrogen (Lyman-alpha emission) is the strongest and most conspicuous feature in the solar EUV spectrum. Due to the favourable circumstance, that the Lyman-alpha wavelength (121.5 nm) coincides with a minimum of the O 2 absorption spectrum, the direct Lyman-alpha radiation penetrates well in the mesosphere. The Lyman-alpha radiation is the basic agent of the NO molecules ionization, thus generating the ionospheric D-layer, and of the water vapour photolysis, being one of the main H 2 O loss processes. The Lyman-alpha radiation transfer depends on the resonance scattering from the hydrogen atoms in the atmosphere and on the O 2 absorption. Since the Lyman-alpha extinction in the atmosphere is a measure for the column density of the oxygen molecules, the atmospheric temperature profile can be calculated thereof. The detector of solar Lyman-alpha radiation was manufactured in the Stara Zagora Department of the Solar-Terrestrial Influences Laboratory (STIL). Its basic part is an ionization chamber, filled in with NO. A 60 V power supply is applied to the chamber. The produced photoelectric current from the sensor is fed to a 2-channels amplifier, providing an analogue signal. The characteristics of the Lyman-alpha detector were studied. It passed successfully all tests and the results showed that the instrument could be used in rocket experiments to measure the Lyman-alpha flux. From the measurements of the detector, the Lyman-alpha vertical profile can be obtained. The forthcoming scientific data analysis will

  7. Software simulation and experimental characterisation of a rotationally asymmetrical concentrator under direct and diffuse solar radiation

    International Nuclear Information System (INIS)

    Freier, Daria; Muhammad-Sukki, Firdaus; Abu-Bakar, Siti Hawa; Ramirez-Iniguez, Roberto; Abubakar Mas’ud, Abdullahi; Albarracín, Ricardo; Ardila-Rey, Jorge Alfredo; Munir, Abu Bakar; Mohd Yasin, Siti Hajar; Bani, Nurul Aini

    2016-01-01

    Highlights: • The performance of the RADTIRC was analysed under direct and diffuse radiation. • Optical gains of 4.66 under direct and 1.94 under diffuse light were achieved. • The experiments show good agreement with the simulations. • The RADTIRC is an attractive alternative for BICPV systems. - Abstract: Making housing carbon neutral is one of the European Union (EU) targets with the aim to reduce energy consumption and to increase on-site renewable energy generation in the domestic sector. Optical concentrators have a strong potential to minimise the cost of building integrated photovoltaic (BIPV) systems by replacing expensive photovoltaic (PV) material whilst maintaining the same electrical output. In this work, the performance of a recently patented optical concentrator known as the rotationally asymmetrical dielectric totally internally reflective concentrator (RADTIRC) was analysed under direct and diffuse light conditions. The RADTIRC has a geometrical concentration gain of 4.969 and two half acceptance angles of ±40° and ±30° respectively along the two axes. Simulation and experimental work has been carried out to determine the optical concentration gain and the angular response of the concentrator. It was found that the RADTIRC has an optical concentration gain of 4.66 under direct irradiance and 1.94 under diffuse irradiance. The experimental results for the single concentrator showed a reduction in concentration gain of 4.2% when compared with simulation data.

  8. Models of diffuse solar radiation

    Energy Technology Data Exchange (ETDEWEB)

    Boland, John; Ridley, Barbara [Centre for Industrial and Applied Mathematics, University of South Australia, Mawson Lakes Boulevard, Mawson Lakes, SA 5095 (Australia); Brown, Bruce [Department of Statistics and Applied Probability, National University of Singapore, Singapore 117546 (Singapore)

    2008-04-15

    For some locations both global and diffuse solar radiation are measured. However, for many locations, only global is measured, or inferred from satellite data. For modelling solar energy applications, the amount of radiation on a tilted surface is needed. Since only the direct component on a tilted surface can be calculated from trigonometry, we need to have diffuse on the horizontal available. There are regression relationships for estimating the diffuse on a tilted surface from diffuse on the horizontal. Models for estimating the diffuse radiation on the horizontal from horizontal global that have been developed in Europe or North America have proved to be inadequate for Australia [Spencer JW. A comparison of methods for estimating hourly diffuse solar radiation from global solar radiation. Sol Energy 1982; 29(1): 19-32]. Boland et al. [Modelling the diffuse fraction of global solar radiation on a horizontal surface. Environmetrics 2001; 12: 103-16] developed a validated model for Australian conditions. We detail our recent advances in developing the theoretical framework for the approach reported therein, particularly the use of the logistic function instead of piecewise linear or simple nonlinear functions. Additionally, we have also constructed a method, using quadratic programming, for identifying values that are likely to be erroneous. This allows us to eliminate outliers in diffuse radiation values, the data most prone to errors in measurement. (author)

  9. Daytime relapse of the mean radiant temperature based on the six-directional method under unobstructed solar radiation.

    Science.gov (United States)

    Kántor, Noémi; Lin, Tzu-Ping; Matzarakis, Andreas

    2014-09-01

    This study contributes to the knowledge about the capabilities of the popular "six-directional method" describing the radiation fields outdoors. In Taiwan, measurements were carried out with three orthogonally placed net radiometers to determine the mean radiant temperature (T(mrt)). The short- and long-wave radiation flux densities from the six perpendicular directions were recorded in the daylight hours of 12 days. During unobstructed direct irradiation, a specific daytime relapse was found in the temporal course of the T(mrt) values referring to the reference shapes of a standing man and also of a sphere. This relapse can be related to the short-wave fluxes reaching the body from the lateral directions. Through deeper analysis, an instrumental shortcoming of the six-directional technique was discovered. The pyranometer pairs of the same net radiometer have a 10-15-min long "blind spot" when the sun beams are nearly perpendicular to them. The blind-spot period is supposed to be shorter with steeper solar azimuth curve on the daylight period. This means that the locations with lower geographical latitude, and the summertime measurements, are affected less by this instrumental problem. A methodological shortcoming of the six-directional technique was also demonstrated. Namely, the sum of the short-wave flux densities from the lateral directions is sensitive to the orientation of the radiometers, and therefore by deviating from the original directions, the T(mrt) decrease on clear sunny days will occur in different times and will be different in extent.

  10. Solar constant values for estimating solar radiation

    International Nuclear Information System (INIS)

    Li, Huashan; Lian, Yongwang; Wang, Xianlong; Ma, Weibin; Zhao, Liang

    2011-01-01

    There are many solar constant values given and adopted by researchers, leading to confusion in estimating solar radiation. In this study, some solar constant values collected from literature for estimating solar radiation with the Angstroem-Prescott correlation are tested in China using the measured data between 1971 and 2000. According to the ranking method based on the t-statistic, a strategy to select the best solar constant value for estimating the monthly average daily global solar radiation with the Angstroem-Prescott correlation is proposed. -- Research highlights: → The effect of the solar constant on estimating solar radiation is investigated. → The investigation covers a diverse range of climate and geography in China. → A strategy to select the best solar constant for estimating radiation is proposed.

  11. Solar cell radiation handbook

    Science.gov (United States)

    Tada, H. Y.; Carter, J. R., Jr.; Anspaugh, B. E.; Downing, R. G.

    1982-01-01

    The handbook to predict the degradation of solar cell electrical performance in any given space radiation environment is presented. Solar cell theory, cell manufacturing and how they are modeled mathematically are described. The interaction of energetic charged particles radiation with solar cells is discussed and the concept of 1 MeV equivalent electron fluence is introduced. The space radiation environment is described and methods of calculating equivalent fluences for the space environment are developed. A computer program was written to perform the equivalent fluence calculations and a FORTRAN listing of the program is included. Data detailing the degradation of solar cell electrical parameters as a function of 1 MeV electron fluence are presented.

  12. A New Database of Global and Direct Solar Radiation Using the Eastern Meteosat Satellite, Models and Validation

    Directory of Open Access Journals (Sweden)

    Ana Gracia Amillo

    2014-08-01

    Full Text Available We present a new database of solar radiation at ground level for Eastern Europe and Africa, the Middle East and Asia, estimated using satellite images from the Meteosat East geostationary satellites. The method presented calculates global horizontal (G and direct normal irradiance (DNI at hourly intervals, using the full Meteosat archive from 1998 to present. Validation of the estimated global horizontal and direct normal irradiance values has been performed by comparison with high-quality ground station measurements. Due to the low number of ground measurements in the viewing area of the Meteosat Eastern satellites, the validation of the calculation method has been extended by a comparison of the estimated values derived from the same class of satellites but positioned at 0°E, where more ground stations are available. Results show a low overall mean bias deviation (MBD of +1.63 Wm−2 or +0.73% for global horizontal irradiance. The mean absolute bias of the individual station MBD is 2.36%, while the root mean square deviation of the individual MBD values is 3.18%. For direct normal irradiance the corresponding values are overall MBD of +0.61 Wm−2 or +0.62%, while the mean absolute bias of the individual station MBD is 5.03% and the root mean square deviation of the individual MBD values is 6.30%. The resulting database of hourly solar radiation values will be made freely available. These data will also be integrated into the PVGIS web application to allow users to estimate the energy output of photovoltaic (PV systems not only in Europe and Africa, but now also in Asia.

  13. Solar radiation for Mars power systems

    Science.gov (United States)

    Appelbaum, Joseph; Landis, Geoffrey A.

    1991-01-01

    Detailed information about the solar radiation characteristics on Mars are necessary for effective design of future planned solar energy systems operating on the surface of Mars. A procedure and solar radiation related data from which the diurnally and daily variation of the global, direct (or beam), and diffuse insolation on Mars are calculated, are presented. The radiation data are based on measured optical depth of the Martian atmosphere derived from images taken of the Sun with a special diode on the Viking Lander cameras; and computation based on multiple wavelength and multiple scattering of the solar radiation.

  14. MODELING OF DIRECT SOLAR RADIATION IN A COMPOUND PARABOLIC COLLECTOR (CPC WITH THE RAY TRACING TECHNIQUE

    Directory of Open Access Journals (Sweden)

    JOSÉ A. COLINA MÁRQUEZ

    2010-01-01

    Full Text Available El colector parabólico compuesto (CPC es una tecnología ampliamente usada en aplicaciones fotoquímicas, como las reacciones fotocatalíticas. Para propósitos cinéticos en esta clase de reacciones, se debe conocer la distribución de la radiación ya que la velocidad de reacción depende la absorción de fotones. En el presente trabajo desarrolló un modelo matemático que permitió simular el fenómeno de reflexión de la radiación solar directa en un CPC. Las ecuaciones se evaluaron usando geometría analítica y cálculo vectorial, primero para calcular las coordenadas cartesianas de la superficie reflectiva. Luego estos puntos se usaron para calcular las trayectorias de los rayos incidentes y reflejados en cualquier instante. La radiación incidente en el receptor se graficó independientemente, mostrando la distribución de la energía directa que llega directamente al absorbedor. La longitud de la involuta también se calculó a partir de estos datos, los cuales pueden resultar muy útiles para su construcción. Los resultados obtenidos a partir de las simulaciones muestran que la distribución de la energía incidente en la superficie del absorbedor depende de la reflectividad de la superficie del CPC. La energía incidente es mayor en la parte superior que en la inferior del absorbedor, y son más convenientes valores altos de reflectividad para distribuciones de energía más uniformes. Este modelo matemático puede ser una primera aproximación para modelos más complejos de absorción de fotones que incluyan radiación solar directa en aplicaciones fotoquímicas o fototérmicas.

  15. Measurement of solar radiation at the Earth's surface

    Science.gov (United States)

    Bartman, F. L.

    1982-01-01

    The characteristics of solar energy arriving at the surface of the Earth are defined and the history of solar measurements in the United States presented. Radiation and meteorological measurements being made at solar energy meteorological research and training sites and calibration procedures used there are outlined. Data illustrating the annual variation in daily solar radiation at Ann Arbor, Michigan and the diurnal variation in radiation at Albuquerque, New Mexico are presented. Direct normal solar radiation received at Albuquerque is contrasted with that received at Maynard, Massachusetts. Average measured global radiation for a period of one year for four locations under clear skies, 50% cloud cover, and 100% cloud cover is given and compared with the solar radiation at the top of the atmosphere. The May distribution of mean daily direct solar radiation and mean daily global solar radiation over the United States is presented. The effects of turbidity on the direct and circumsolar radiation are shown.

  16. Solar radiation on Mars: Update 1991

    Science.gov (United States)

    Appelbaum, Joseph; Landis, Geoffrey A.

    1991-01-01

    Detailed information on solar radiation characteristics on Mars are necessary for effective design of future planned solar energy systems operating on the surface of Mars. A procedure and solar radiation related data are presented from which the daily variation of the global, direct beam and diffuse insolation on Mars are calculated. Given the optical depth of the Mars atmosphere, the global radiation is calculated from the normalized net flux function based on multiple wavelength and multiple scattering of the solar radiation. The direct beam was derived from the optical depth using Beer's law, and the diffuse component was obtained from the difference of the global and the direct beam radiation. The optical depths of the Mars atmosphere were derived from images taken of the Sun with a special diode on the cameras used on the two Viking Landers.

  17. Effects of solar radiation on glass

    Science.gov (United States)

    Tucker, Dennis S.; Kinser, Donald L.

    1991-01-01

    The effects of solar radiation of selected glasses are reported. Optical property degradation is studied using UV-Vis spectrophotometry. Strength changes are measured using a concentric ring bend test. Direct fracture toughness measurements using an indentation test are planned.

  18. Coordinated weather balloon solar radiation measurements during a solar eclipse.

    Science.gov (United States)

    Harrison, R G; Marlton, G J; Williams, P D; Nicoll, K A

    2016-09-28

    Solar eclipses provide a rapidly changing solar radiation environment. These changes can be studied using simple photodiode sensors, if the radiation reaching the sensors is unaffected by cloud. Transporting the sensors aloft using standard meteorological instrument packages modified to carry extra sensors, provides one promising but hitherto unexploited possibility for making solar eclipse radiation measurements. For the 20 March 2015 solar eclipse, a coordinated campaign of balloon-carried solar radiation measurements was undertaken from Reading (51.44°N, 0.94°W), Lerwick (60.15°N, 1.13°W) and Reykjavik (64.13°N, 21.90°W), straddling the path of the eclipse. The balloons reached sufficient altitude at the eclipse time for eclipse-induced variations in solar radiation and solar limb darkening to be measured above cloud. Because the sensor platforms were free to swing, techniques have been evaluated to correct the measurements for their changing orientation. In the swing-averaged technique, the mean value across a set of swings was used to approximate the radiation falling on a horizontal surface; in the swing-maximum technique, the direct beam was estimated by assuming that the maximum solar radiation during a swing occurs when the photodiode sensing surface becomes normal to the direction of the solar beam. Both approaches, essentially independent, give values that agree with theoretical expectations for the eclipse-induced radiation changes.This article is part of the themed issue 'Atmospheric effects of solar eclipses stimulated by the 2015 UK eclipse'. © 2016 The Authors.

  19. Solar ultraviolet radiation cataract.

    Science.gov (United States)

    Löfgren, Stefan

    2017-03-01

    Despite being a treatable disease, cataract is still the leading cause for blindness in the world. Solar ultraviolet radiation is epidemiologically linked to cataract development, while animal and in vitro studies prove a causal relationship. However, the pathogenetic pathways for the disease are not fully understood and there is still no perfect model for human age related cataract. This non-comprehensive overview focus on recent developments regarding effects of solar UV radiation wavebands on the lens. A smaller number of fundamental papers are also included to provide a backdrop for the overview. Future studies are expected to further clarify the cellular and subcellular mechanisms for UV radiation-induced cataract and especially the isolated or combined temporal and spatial effects of UVA and UVB in the pathogenesis of human cataract. Regardless of the cause for cataract, there is a need for advances in pharmaceutical or other treatment modalities that do not require surgical replacement of the lens. Copyright © 2016. Published by Elsevier Ltd.

  20. Availability of solar radiation and standards for solar access

    Energy Technology Data Exchange (ETDEWEB)

    Casabianca, G.A.; Evans, J.M. [Research Centre Habitat and Energy, Facultad de Arquitectura, Diseno y Urbanismo, Universidad de Buenos Aires, Capital Federal (Argentina)

    1997-12-31

    In southern Argentina, a region between latitudes 38 deg C and 55 deg C S, the heating demand in the residential sector is high while the availability of solar radiation is limited. A new proposal for solar access standards has been developed, taking into account the climatic conditions of each location, the effective availability of solar radiation and the direct sunlight requirements. This study analyses the climatic conditions for the Patagonia, relating heating demand and solar radiation availability in different sites, and presents the development of new sunlight standards that respond to these regional conditions. As a result of this study, the new Argentine standard TRAM 11.603 includes new conditions to protect solar access and provide design recommendations. (orig.) 4 refs.

  1. Temperature and Solar Radiation Effects on Photovoltaic Panel Power

    OpenAIRE

    Karafil, Akif; Ozbay, Harun; Kesler, Metin

    2016-01-01

    Solar energy is converted to electrical energy directly by semi-conductors materials used in Photovoltaic (PV) panels. Although, there has been great advancements in semi-conductor material technology in recent years panel efficiency is very lower. There are many factors affecting the panel efficiency such as tilt angle, shading, dust, solar radiation level, temperature and wiring losses. Among these factors, solar radiation level and temperature are more prominent. The solar radiation level ...

  2. Solar and infrared radiation measurements

    CERN Document Server

    Vignola, Frank; Michalsky, Joseph

    2012-01-01

    The rather specialized field of solar and infrared radiation measurement has become more and more important in the face of growing demands by the renewable energy and climate change research communities for data that are more accurate and have increased temporal and spatial resolution. Updating decades of acquired knowledge in the field, Solar and Infrared Radiation Measurements details the strengths and weaknesses of instruments used to conduct such solar and infrared radiation measurements. Topics covered include: Radiometer design and performance Equipment calibration, installation, operati

  3. Solar radiation absorbing material

    Science.gov (United States)

    Googin, John M.; Schmitt, Charles R.; Schreyer, James M.; Whitehead, Harlan D.

    1977-01-01

    Solar energy absorbing means in solar collectors are provided by a solar selective carbon surface. A solar selective carbon surface is a microporous carbon surface having pores within the range of 0.2 to 2 micrometers. Such a surface is provided in a microporous carbon article by controlling the pore size. A thermally conductive substrate is provided with a solar selective surface by adhering an array of carbon particles in a suitable binder to the substrate, a majority of said particles having diameters within the range of about 0.2-10 microns.

  4. Fluctuation characteristics of solar radiation in crop cultivation

    International Nuclear Information System (INIS)

    Hayashi, S.; Suzuki, H.

    1996-01-01

    The objective of this study was to clarify the fluctuation of solar radiation for long and short periods, which is very crucial for plant growth. Data obtained from a meteorological observatory were used to investigate solar radiation and sunshine duration for a long period. For a short period, observation of global solar radiation and sky solar radiation were conducted in a glass house and at an open field. (1) Yearly average percentage of solar radiation at Kagawa from 1973 to 1994 was 44.3%, and its coefficient of variation was 3.9%. The percentage of possible sunshine and the coefficient were larger than those of solar radiation, 47.3% and 56% respectively. (2) Percentage of possible solar radiation and percentage of possible sunshine showed seasonal variation. Those coefficients of variation both increased exponentially with cloud amount. (3) Variations of global solar radiation and direct solar radiation were more remarkable in the glass house than those in the open field, while variations of sky solar radiation were small in the house and at the open field. (4) The fluctuation of solar radiation observed every 5 minutes was presented as the difference of radiation, present value minus the preceding value. The difference was positive in the morning, negative in the afternoon at the open field. In the house both positive and negative values were obtained the whole day. (5) Diurnal variation of ratio of direct solar radiation to sky solar radiation showed a parabolic effect, whereas it had irregular and large fluctuations at the open field

  5. Radiation hard solar cell and array

    International Nuclear Information System (INIS)

    Russell, R.L.

    1975-01-01

    A power generating solar cell for a spacecraft solar array is hardened against transient response to nuclear radiation while permitting normal operation of the cell in a solar radiation environment by shunting the cell with a second solar cell whose contacts are reversed relative to the power cell to form a cell module, exposing the power cell only to the solar radiation in a solar radiation environment to produce an electrical output at the module terminals, and exposing both cells to the nuclear radiation in a nuclear radiation environment so that the radiation induced currents generated by the cells suppress one another

  6. Analysis of the ozone profile specifications in the WRF-ARW model and their impact on the simulation of direct solar radiation

    Directory of Open Access Journals (Sweden)

    A. Montornès

    2015-03-01

    Full Text Available Although ozone is an atmospheric gas with high spatial and temporal variability, mesoscale numerical weather prediction (NWP models simplify the specification of ozone concentrations used in their shortwave schemes by using a few ozone profiles. In this paper, a two-part study is presented: (i an evaluation of the quality of the ozone profiles provided for use with the shortwave schemes in the Advanced Research version of the Weather Research and Forecasting (WRF-ARW model and (ii an assessment of the impact of deficiencies in those profiles on the performance of model simulations of direct solar radiation. The first part compares simplified data sets used to specify the total ozone column in six schemes (i.e., Goddard, New Goddard, RRTMG, CAM, GFDL and Fu–Liou–Gu with the Multi-Sensor Reanalysis data set during the period 1979–2008 examining the latitudinal, longitudinal and seasonal limitations in the ozone profile specifications of each parameterization. The results indicate that the maximum deviations are over the poles and show prominent longitudinal patterns in the departures due to the lack of representation of the patterns associated with the Brewer–Dobson circulation and the quasi-stationary features forced by the land–sea distribution, respectively. In the second part, the bias in the simulated direct solar radiation due to these deviations from the simplified spatial and temporal representation of the ozone distribution is analyzed for the New Goddard and CAM schemes using the Beer–Lambert–Bouguer law and for the GFDL using empirical equations. For radiative applications those simplifications introduce spatial and temporal biases with near-zero departures over the tropics throughout the year and increasing poleward with a maximum in the high middle latitudes during the winter of each hemisphere.

  7. Solar radiation on domed roofs

    Energy Technology Data Exchange (ETDEWEB)

    Faghih, Ahmadreza K.; Bahadori, Mehdi N. [School of Mechanical Engineering, Sharif University of Technology, Tehran (Iran)

    2009-11-15

    Solar radiation received and absorbed by four domed roofs was estimated and compared with that of a flat roof. The domed roofs all had the same base areas, and equal to that of the flat roof. One of the roofs considered was the dome of the St. Peter's Church in Rome. Compared with the other roofs considered, this dome had a higher aspect ratio. It was found that all domed roofs received more solar radiation than the flat roof. Considering glazed tiles to cover a selected dome in Iran and the dome of the St. Peter's Church, it was found that the solar radiation absorbed by these roofs is reduced appreciably. In the case of the dome of St. Peter's Church, the amount of radiation absorbed was roughly equal to that absorbed by the comparable flat roof in the warm months. In the case of the glazed reference dome located in Yazd, Iran (a city with very high solar radiation), the radiation absorbed was less than that of flat roof at all times. In addition to aesthetics, this may be a reason for employing glazed tiles to cover the domes of all mosques, shrines, and other large buildings in Iran. (author)

  8. Estimating solar radiation in Ghana

    International Nuclear Information System (INIS)

    Anane-Fenin, K.

    1986-04-01

    The estimates of global radiation on a horizontal surface for 9 towns in Ghana, West Africa, are deduced from their sunshine data using two methods developed by Angstrom and Sabbagh. An appropriate regional parameter is determined with the first method and used to predict solar irradiation in all the 9 stations with an accuracy better than 15%. Estimation of diffuse solar irradiation by Page, Lin and Jordan and three other authors' correlation are performed and the results examined. (author)

  9. An automatic measuring system for mapping of spectral and angular dependence of direct and diffuse solar radiation; Et automatisk maalesystem for kartlegging av vinkel- og spektralfordeling av direkte og diffus solstraaling

    Energy Technology Data Exchange (ETDEWEB)

    Grandum, Oddbjoern

    1997-12-31

    In optimizing solar systems, it is necessary to know the spectral and angular dependence of the radiation. The general nonlinear character of most solar energy systems accentuates this. This thesis describes a spectroradiometer that will measure both the direct component of the solar radiation and the angular dependence of the diffuse component. Radiation from a selected part of the sky is transported through a movable set of tube sections on to a stationary set of three monochromators with detectors. The beam transport system may effectively be looked upon as a single long tube aimed at a particular spot in the sky. The half value of the effective opening angle is 1.3{sup o} for diffuse radiation and 2.8{sup o} for direct radiation. The whole measurement process is controlled and operated by a PC and normally runs without manual attention. The instrument is built into a caravan. The thesis describes in detail the experimental apparatus, calibration and measurement accuracies. To map the diffuse radiation, one divides the sky into 26 sectors of equal solid angle. A complete measurement cycle is then made at a random point within each sector. These measurements are modelled by fitting to spherical harmonics, enforcing symmetry around the solar direction and the horizontal plane. The direct radiation is measured separately. Also the circumsolar sector is given special treatment. The measurements are routinely checked against global radiation measured in parallel by a standard pyranometer, and direct solar radiation by a pyrheliometer. An extensive improvement programme is being planned for the instrument, including the use of a photomultiplier tube to measure the UV part of the spectrum, a diode array for the 400-1100 nm range, and use of a Ge diode for the 1000-1900 nm range. 78 refs., 90 figs., 31 tabs.

  10. Study of the lacustrine phytoplankton productivity dependence on solar radiation, on the basis of direct high-frequency measurements

    Science.gov (United States)

    Provenzale, Maria; Ojala, Anne; Heiskanen, Jouni; Erkkilä, Kukka-Maaria; Mammarella, Ivan; Hari, Pertti; Vesala, Timo

    2016-04-01

    One of the main components of the carbon cycle in lakes is phytoplankton. Its in situ photosynthesis and respiration are usually studied with traditional methods (dark and light bottle method, 14C labelling technique). These methods, relying on sampling and incubation, may lead to unrealistic results. They also have a poor temporal resolution, which does not allow the non-linear relationship between photosynthetically active solar radiation (PAR) and photosynthesis to be properly investigated. As a consequence, the phytoplankton net primary productivity (NPP) cannot be parameterised as a function of ambient variables. In 2008 an innovative free-water approach was proposed. It is based on non-dispersive infrared air CO2 probes that, by building an appropriate system, can be used to measure the CO2 concentration in the water at a high-frequency. At that time, the method was tested only on 3 days of data. Here, we deployed it on a boreal lake in Finland for four summers, in order to calculate the NPP and verify its dependence on PAR. The set-up was completed by an eddy-covariance system and water PAR and temperature sensors. In analogy with the procedure typically used in terrestrial ecology, we obtained the phytoplankton NPP computing the mass balance of CO2 in the mixed layer of the lake, i.e. the superficial layer where the conditions are homogeneous and most of the photosynthetic activity takes place. After calculating the NPP , we verified its dependence on PAR. The theoretical model we used was a saturating Michaelis-Menten curve, in which the variables are water temperature and PAR. The equation also contains parameters typical of the phytoplankton communities, which represent their maximum potential photosynthetic rate, their half-saturation constant and their basal respiration. These parameters allow the NPP to be parameterised as a function of T and PAR. For all the analysed year, we found a very good agreement between theory and data (R2 ranged from 0.80 to

  11. An auto-calibration procedure for empirical solar radiation models

    NARCIS (Netherlands)

    Bojanowski, J.S.; Donatelli, Marcello; Skidmore, A.K.; Vrieling, A.

    2013-01-01

    Solar radiation data are an important input for estimating evapotranspiration and modelling crop growth. Direct measurement of solar radiation is now carried out in most European countries, but the network of measuring stations is too sparse for reliable interpolation of measured values. Instead of

  12. NEW MODEL FOR SOLAR RADIATION ESTIMATION FROM ...

    African Journals Online (AJOL)

    NEW MODEL FOR SOLAR RADIATION ESTIMATION FROM MEASURED AIR TEMPERATURE AND ... Nigerian Journal of Technology ... Solar radiation measurement is not sufficient in Nigeria for various reasons such as maintenance and ...

  13. SORCE: Solar Radiation and Climate Experiment

    Science.gov (United States)

    Cahalan, Robert; Rottman, Gary; Lau, William K. M. (Technical Monitor)

    2002-01-01

    Contents include the following: Understanding the Sun's influence on the Earth; How the Sun affect Earth's climate; By how much does the Sun's radiation very; Understanding Solar irradiance; History of Solar irradiance observations; The SORCE mission; How do the SORCE instruments measure solar radiation; Total irradiance monitor (TIM); Spectral irradiance monitor (SIM); Solar stellar irradiance comparison experiment (SOLSTICE); XUV photometer system (XPS).

  14. ANALYSIS OF MEASURED AND MODELED SOLAR RADIATION AT THE TARS SOLAR HEATING PLANT IN DENMARK

    DEFF Research Database (Denmark)

    Tian, Zhiyong; Perers, Bengt; Furbo, Simon

    2017-01-01

    , such as solar radiation, inlet and outlet temperature for the solar collector field, flow rate and pressure, ambient temperature, Wind speed and wind direction were measured. Global horizontal radiation, direct normal irradiation (DNI) and total radiation on the tilted collector plane of the flat plate...... collector field have been measured in Tars solar heating plant. To determine the accuracy of modeled and measured solar radiation in Tars solar heating plant, monthly comparisons of measured and calculated radiation using 6 empirical models have been carried out. Comparisons of measured and modeled total......A novel combined solar heating plant with tracking parabolic trough collectors (PTC) and flat plate collectors (FPC) has been constructed and put into operation in Tars, 30 km north of Aalborg, Denmark in August 2015. To assess the operation performance of the plant, detailed parameters...

  15. Snow, ice and solar radiation

    NARCIS (Netherlands)

    Kuipers Munneke, P.

    2009-01-01

    The snow-covered ice sheets of Antarctica and Greenland reflect most of the incoming solar radiation. The reflectivity, commonly called the albedo, of snow on these ice sheets has been observed to vary in space and time. In this thesis, temporal and spatial changes in snow albedo is found to depend

  16. Solar radiation modeling and measurements for renewable energy applications: data and model quality

    International Nuclear Information System (INIS)

    Myers, Daryl R.

    2005-01-01

    Measurement and modeling of broadband and spectral terrestrial solar radiation is important for the evaluation and deployment of solar renewable energy systems. We discuss recent developments in the calibration of broadband solar radiometric instrumentation and improving broadband solar radiation measurement accuracy. An improved diffuse sky reference and radiometer calibration and characterization software for outdoor pyranometer calibrations are outlined. Several broadband solar radiation model approaches, including some developed at the National Renewable Energy Laboratory, for estimating direct beam, total hemispherical and diffuse sky radiation are briefly reviewed. The latter include the Bird clear sky model for global, direct beam, and diffuse terrestrial solar radiation; the Direct Insolation Simulation Code (DISC) for estimating direct beam radiation from global measurements; and the METSTAT (Meteorological and Statistical) and Climatological Solar Radiation (CSR) models that estimate solar radiation from meteorological data. We conclude that currently the best model uncertainties are representative of the uncertainty in measured data

  17. Solar radiation modeling and measurements for renewable energy applications: data and model quality

    Energy Technology Data Exchange (ETDEWEB)

    Myers, D.R. [National Renewable Energy Laboratory, Golden, CO (United States)

    2005-07-01

    Measurement and modeling of broadband and spectral terrestrial solar radiation is important for the evaluation and deployment of solar renewable energy systems. We discuss recent developments in the calibration of broadband solar radiometric instrumentation and improving broadband solar radiation measurement accuracy. An improved diffuse sky reference and radiometer calibration and characterization software for outdoor pyranometer calibrations are outlined. Several broadband solar radiation model approaches, including some developed at the National Renewable Energy Laboratory, for estimating direct beam, total hemispherical and diffuse sky radiation are briefly reviewed. The latter include the Bird clear sky model for global, direct beam, and diffuse terrestrial solar radiation; the Direct Insolation Simulation Code (DISC) for estimating direct beam radiation from global measurements; and the METSTAT (Meteorological and Statistical) and Climatological Solar Radiation (CSR) models that estimate solar radiation from meteorological data. We conclude that currently the best model uncertainties are representative of the uncertainty in measured data. (author)

  18. Radiating properties of solar plasmas

    Science.gov (United States)

    Bruner, M. E.; Mcwhirter, R. W. P.

    1988-01-01

    Using a series of 14 previously obtained empirical emission measure distributions and a number of spectral lines observed by the SMM and P78-1 instruments, the total power radiated by a hot plasma is compared to that radiated by individual spectrum lines. Results are presented for different choices of ionization balance and power loss functions. The results indicate that for some lines such as the C IV resonance doublet at 1548 A and 1550 A, the ratio of the line intensity to the total radiated power varied only over a factor of 2, suggesting that well-calibrated measurements of a single line intensity may provide a fairly good estimation of the total radiated power output from the solar plasma.

  19. Radiating properties of solar plasmas

    International Nuclear Information System (INIS)

    Bruner, M.E.; Mcwhirter, R.W.P.

    1988-01-01

    Using a series of 14 previously obtained empirical emission measure distributions and a number of spectral lines observed by the SMM and P78-1 instruments, the total power radiated by a hot plasma is compared to that radiated by individual spectrum lines. Results are presented for different choices of ionization balance and power loss functions. The results indicate that for some lines such as the C IV resonance doublet at 1548 A and 1550 A, the ratio of the line intensity to the total radiated power varied only over a factor of 2, suggesting that well-calibrated measurements of a single line intensity may provide a fairly good estimation of the total radiated power output from the solar plasma. 21 references

  20. Conversion of solar radiation using parabolic mirrors

    Directory of Open Access Journals (Sweden)

    Jolanta Fieducik

    2017-08-01

    Full Text Available The use of solar energy is a promising source of renewable energy to cover the energy needs of our society. The aim of the study will be to analyze the possibility of converting solar energy using parabolic reflectors to the heat energy needed to meet the needs of hot water for a family of 4 people. This study presents simulations of the use of solar radiation using radiant concentration systems. The parabolic mirror directs the concentrated beam of sunlight onto a tube located in the focal plane, which is filled with water that under the influence of solar radiation heats up. This article assumes constant mirror geometry and tube cross section, while simulation is performed for different coefficients. For calculations it was assumed that the reflection coefficient of sunlight from the mirror r is variable and an analysis of its effect on the amount of heated liquid is made. The radiation absorption coefficient across the tube surface was determined by a, the thermal surface emissivity coefficient was determined as e and the simulations were performed at variable values for the amount of heated liquid. The calculations and their analysis show that, with appropriately chosen coefficients, it is possible to meet the needs of a 4-person family in warm water using the proposed installation in Poland.

  1. Impact of climate change on occupational exposure to solar radiation.

    Science.gov (United States)

    Grandi, Carlo; Borra, Massimo; Militello, Andrea; Polichetti, Alessandro

    2016-01-01

    Occupational exposure to solar radiation may induce both acute and long-term effects on skin and eyes. Personal exposure is very difficult to assess accurately, as it depends on environmental, organisational and individual factors. The ongoing climate change interacting with stratospheric ozone dynamics may affect occupational exposure to solar radiation. In addition, tropospheric levels of environmental pollutants interacting with solar radiation may be altered by climate dynamics, so introducing another variable affecting the overall exposure to solar radiation. Given the uncertainties regarding the direction of changes in exposure to solar radiation due to climate change, compliance of outdoor workers with protective measures and a proper health surveillance are crucial. At the same time, education and training, along with the promotion of healthier lifestyles, are of paramount importance.

  2. Near-term Forecasting of Solar Total and Direct Irradiance for Solar Energy Applications

    Science.gov (United States)

    Long, C. N.; Riihimaki, L. D.; Berg, L. K.

    2012-12-01

    Integration of solar renewable energy into the power grid, like wind energy, is hindered by the variable nature of the solar resource. One challenge of the integration problem for shorter time periods is the phenomenon of "ramping events" where the electrical output of the solar power system increases or decreases significantly and rapidly over periods of minutes or less. Advance warning, of even just a few minutes, allows power system operators to compensate for the ramping. However, the ability for short-term prediction on such local "point" scales is beyond the abilities of typical model-based weather forecasting. Use of surface-based solar radiation measurements has been recognized as a likely solution for providing input for near-term (5 to 30 minute) forecasts of solar energy availability and variability. However, it must be noted that while fixed-orientation photovoltaic panel systems use the total (global) downwelling solar radiation, tracking photovoltaic and solar concentrator systems use only the direct normal component of the solar radiation. Thus even accurate near-term forecasts of total solar radiation will under many circumstances include inherent inaccuracies with respect to tracking systems due to lack of information of the direct component of the solar radiation. We will present examples and statistical analyses of solar radiation partitioning showing the differences in the behavior of the total/direct radiation with respect to the near-term forecast issue. We will present an overview of the possibility of using a network of unique new commercially available total/diffuse radiometers in conjunction with a near-real-time adaptation of the Shortwave Radiative Flux Analysis methodology (Long and Ackerman, 2000; Long et al., 2006). The results are used, in conjunction with persistence and tendency forecast techniques, to provide more accurate near-term forecasts of cloudiness, and both total and direct normal solar irradiance availability and

  3. About Solar Radiation Intensity Measurements and Data Processing

    Directory of Open Access Journals (Sweden)

    MICH-VANCEA Claudiu

    2012-10-01

    Full Text Available Measuring the intensity of solar radiation is one of the directions of investigation necessary for the implementation of photovoltaic systems in a particular geographical area. This can be done by using specific measuring equipment (pyranometer sensors based onthermal or photovoltaic principle. In this paper it is presented a method for measuring solar radiation (which has two main components - direct radiation and diffuse radiation with sensors based on photovoltaic principle. Such data are processed for positioning solarpanels, in order their efficiency to be maximized.

  4. Accurate measurement of directional emittance of solar energy materials

    NARCIS (Netherlands)

    Nijnatten, van P.A.; Hugo-Le Gof, A.; Granqvist, C.-G.; Lampert, C.M.

    1992-01-01

    Directional emittance plays an important role in the calculation of radiative heat exchange. It partly determines the thermal insulation of single and multiple glazing and the efficiency of solar collectors. An emissiometer has been designed and built, capable for measurements of the directional

  5. Evaluation of global solar radiation models for Shanghai, China

    International Nuclear Information System (INIS)

    Yao, Wanxiang; Li, Zhengrong; Wang, Yuyan; Jiang, Fujian; Hu, Lingzhou

    2014-01-01

    Highlights: • 108 existing models are compared and analyzed by 42 years meteorological data. • Fitting models based on measured data are established according to 42 years data. • All models are compared by recently 10 years meteorological data. • The results show that polynomial models are the most accurate models. - Abstract: In this paper, 89 existing monthly average daily global solar radiation models and 19 existing daily global solar radiation models are compared and analyzed by 42 years meteorological data. The results show that for existing monthly average daily global solar radiation models, linear models and polynomial models have been able to estimate global solar radiation accurately, and complex equation types cannot obviously improve the precision. Considering direct parameters such as latitude, altitude, solar altitude and sunshine duration can help improve the accuracy of the models, but indirect parameters cannot. For existing daily global solar radiation models, multi-parameter models are more accurate than single-parameter models, polynomial models are more accurate than linear models. Then measured data fitting monthly average daily global solar radiation models (MADGSR models) and daily global solar radiation models (DGSR models) are established according to 42 years meteorological data. Finally, existing models and fitting models based on measured data are comparative analysis by recent 10 years meteorological data, and the results show that polynomial models (MADGSR model 2, DGSR model 2 and Maduekwe model 2) are the most accurate models

  6. Parameterization Of Solar Radiation Using Neural Network

    International Nuclear Information System (INIS)

    Jiya, J. D.; Alfa, B.

    2002-01-01

    This paper presents a neural network technique for parameterization of global solar radiation. The available data from twenty-one stations is used for training the neural network and the data from other ten stations is used to validate the neural model. The neural network utilizes latitude, longitude, altitude, sunshine duration and period number to parameterize solar radiation values. The testing data was not used in the training to demonstrate the performance of the neural network in unknown stations to parameterize solar radiation. The results indicate a good agreement between the parameterized solar radiation values and actual measured values

  7. Calculating the diffuse solar radiation in regions without solar radiation measurements

    International Nuclear Information System (INIS)

    Li, Huashan; Bu, Xianbiao; Long, Zhen; Zhao, Liang; Ma, Weibin

    2012-01-01

    Correlations for calculating diffuse solar radiation can be classified into models with global solar radiation (H-based method) and without it (Non-H method). The objective of the present study is to compare the performance of H-based and Non-H methods for calculating the diffuse solar radiation in regions without solar radiation measurements. The comparison is carried out at eight meteorological stations in China focusing on the monthly average daily diffuse solar radiation. Based on statistical error tests, the results show that the Non-H method that includes other readily available meteorological elements gives better estimates. Therefore, it can be concluded that the Non-H method is more appropriate than the H-based one for calculating the diffuse solar radiation in regions without solar radiation measurements. -- Highlights: ► Methods for calculating diffuse solar radiation in regions without solar radiation measurements are investigated. ► Diffuse solar radiation models can be classified into two groups according to global solar radiation. ► Two approaches are compared at the eight meteorological stations in China. ► The method without global solar radiation is recommended.

  8. In vitro and in vivo assessment of direct effects of simulated solar and galactic cosmic radiation on human hematopoietic stem/progenitor cells.

    Science.gov (United States)

    Rodman, C; Almeida-Porada, G; George, S K; Moon, J; Soker, S; Pardee, T; Beaty, M; Guida, P; Sajuthi, S P; Langefeld, C D; Walker, S J; Wilson, P F; Porada, C D

    2017-06-01

    Future deep space missions to Mars and near-Earth asteroids will expose astronauts to chronic solar energetic particles (SEP) and galactic cosmic ray (GCR) radiation, and likely one or more solar particle events (SPEs). Given the inherent radiosensitivity of hematopoietic cells and short latency period of leukemias, space radiation-induced hematopoietic damage poses a particular threat to astronauts on extended missions. We show that exposing human hematopoietic stem/progenitor cells (HSC) to extended mission-relevant doses of accelerated high-energy protons and iron ions leads to the following: (1) introduces mutations that are frequently located within genes involved in hematopoiesis and are distinct from those induced by γ-radiation; (2) markedly reduces in vitro colony formation; (3) markedly alters engraftment and lineage commitment in vivo; and (4) leads to the development, in vivo, of what appears to be T-ALL. Sequential exposure to protons and iron ions (as typically occurs in deep space) proved far more deleterious to HSC genome integrity and function than either particle species alone. Our results represent a critical step for more accurately estimating risks to the human hematopoietic system from space radiation, identifying and better defining molecular mechanisms by which space radiation impairs hematopoiesis and induces leukemogenesis, as well as for developing appropriately targeted countermeasures.

  9. Solar radiation and human health

    International Nuclear Information System (INIS)

    Juzeniene, Asta; Moan, Kristin; Moan, Johan; Brekke, Paal; Dahlback, Arne; Andersson-Engels, Stefan; Reichrath, Joerg; Holick, Michael F; Grant, William B

    2011-01-01

    The Sun has played a major role in the development of life on Earth. In Western culture, people are warned against Sun exposure because of its adverse effects: erythema, photoimmunosuppression, photoageing, photocarcinogenesis, cataracts and photokeratitis. However, Sun exposure is also beneficial, since moderate doses give beneficial physiological effects: vitamin D synthesis, reduction of blood pressure and mental health. Shortage of Sun exposure may be even more dangerous to human health than excessive exposure. Avoiding Sun exposure leads to vitamin D deficiency which is associated not only with rickets and osteomalacia, but also with increased risk of cardiovascular disease, multiple sclerosis, rheumatoid arthritis, diabetes, influenza, many types of cancer and adverse pregnancy outcomes. Solar radiation induces nitric oxide release in tissue and immediate pigment darkening which certainly play important roles, although these are still unknown. Action spectra relevant for health are described. We will also review what is known about spectral and intensity variations of terrestrial solar radiation as well as its penetration through the atmosphere and into human skin and tissue.

  10. Solar radiation and human health

    Energy Technology Data Exchange (ETDEWEB)

    Juzeniene, Asta; Moan, Kristin; Moan, Johan [Department of Radiation Biology, Institute for Cancer Research, The Norwegian Radium Hospital, Oslo University Hospital, Montebello, N-0310 Oslo (Norway); Brekke, Paal [Norwegian Space Centre, PO Box 113, Skoeyen, N-0212 Oslo (Norway); Dahlback, Arne [Department of Physics, University of Oslo, Blindern, 0316 Oslo (Norway); Andersson-Engels, Stefan [Department of Physics, Lund University, PO Box 118, SE-221 00 Lund (Sweden); Reichrath, Joerg [Klinik fuer Dermatologie, Venerologie und Allergologie, Universitaetsklinikum des Saarlandes, D-66421 Homburg/Saar (Germany); Holick, Michael F [Department of Medicine, Section of Endocrinology, Nutrition and Diabetes, Vitamin D, Skin and Bone Research Laboratory, Boston University Medical Center, 85 E. Newton St., M-1013, Boston, MA 02118 (United States); Grant, William B, E-mail: asta.juzeniene@rr-research.no, E-mail: kmoan@hotmail.com, E-mail: paal.brekke@spacecentre.no, E-mail: arne.dahlback@fys.uio.no, E-mail: j.e.moan@fys.uio.no, E-mail: stefan.andersson-engels@fysik.lth.se, E-mail: joerg.reichrath@uks.eu, E-mail: mfholick@bu.edu, E-mail: wbgrant@infionline.net [Sunlight, Nutrition and Health Research Center (SUNARC), PO Box 641603, San Francisco, CA 94164-1603 (United States)

    2011-06-15

    The Sun has played a major role in the development of life on Earth. In Western culture, people are warned against Sun exposure because of its adverse effects: erythema, photoimmunosuppression, photoageing, photocarcinogenesis, cataracts and photokeratitis. However, Sun exposure is also beneficial, since moderate doses give beneficial physiological effects: vitamin D synthesis, reduction of blood pressure and mental health. Shortage of Sun exposure may be even more dangerous to human health than excessive exposure. Avoiding Sun exposure leads to vitamin D deficiency which is associated not only with rickets and osteomalacia, but also with increased risk of cardiovascular disease, multiple sclerosis, rheumatoid arthritis, diabetes, influenza, many types of cancer and adverse pregnancy outcomes. Solar radiation induces nitric oxide release in tissue and immediate pigment darkening which certainly play important roles, although these are still unknown. Action spectra relevant for health are described. We will also review what is known about spectral and intensity variations of terrestrial solar radiation as well as its penetration through the atmosphere and into human skin and tissue.

  11. Solar radiation and human health

    Science.gov (United States)

    Juzeniene, Asta; Brekke, Pål; Dahlback, Arne; Andersson-Engels, Stefan; Reichrath, Jörg; Moan, Kristin; Holick, Michael F.; Grant, William B.; Moan, Johan

    2011-06-01

    The Sun has played a major role in the development of life on Earth. In Western culture, people are warned against Sun exposure because of its adverse effects: erythema, photoimmunosuppression, photoageing, photocarcinogenesis, cataracts and photokeratitis. However, Sun exposure is also beneficial, since moderate doses give beneficial physiological effects: vitamin D synthesis, reduction of blood pressure and mental health. Shortage of Sun exposure may be even more dangerous to human health than excessive exposure. Avoiding Sun exposure leads to vitamin D deficiency which is associated not only with rickets and osteomalacia, but also with increased risk of cardiovascular disease, multiple sclerosis, rheumatoid arthritis, diabetes, influenza, many types of cancer and adverse pregnancy outcomes. Solar radiation induces nitric oxide release in tissue and immediate pigment darkening which certainly play important roles, although these are still unknown. Action spectra relevant for health are described. We will also review what is known about spectral and intensity variations of terrestrial solar radiation as well as its penetration through the atmosphere and into human skin and tissue.

  12. NREL Solar Radiation Resource Assessment Project: Status and outlook

    Science.gov (United States)

    Renne, D.; Riordan, C.; Maxwell, E.; Stoffel, T.; Marion, B.; Rymes, M.; Wilcox, S.; Myers, D.

    1992-05-01

    This report summarizes the activities and accomplishments of NREL's Solar Radiation Resource Assessment Project during fiscal year 1991. Currently, the primary focus of the SRRAP is to produce a 1961 - 1990 National Solar Radiation Data Base, providing hourly values of global horizontal, diffuse, and direct normal solar radiation at approximately 250 sites around the United States. Because these solar radiation quantities were measured intermittently at only about 50 of these sites, models were developed and applied to the majority of the stations to provide estimates of these parameters. Although approximately 93 percent of the data base consists of modeled data this represents a significant improvement over the SOLMET/ERSATZ 1952 - 1975 data base. The magnitude and importance of this activity are such that the majority of SRRAP human and financial resources were devoted to the data base development. However, in FY 1991 the SRRAP was involved in many other activities, which are reported here. These include the continued maintenance of a solar radiation monitoring network in the southeast United States at six Historically Black Colleges and Universities (HBCU's), the transfer of solar radiation resource assessment technology through a variety of activities, participation in international programs, and the maintenance and operation of NREL's Solar Radiation Research Laboratory.

  13. Solar Radiation Model for Development and Control of Solar Energy Sources

    Directory of Open Access Journals (Sweden)

    Dominykas Vasarevičius

    2016-06-01

    Full Text Available The model of solar radiation, which takes into account direct, diffused and reflected components of solar energy, has been presented. Model is associated with geographical coordinates and local time of every day of the year. It is shown that using analytic equations for modelling the direct component, it is possible to adopt it for embedded systems with low computational power and use in solar tracking applications. Reflected and diffused components are especially useful in determining the performance of photovoltaic modules in certain location and surroundings. The statistical method for cloud layer simulation based on local meteorological data is offered. The presented method can’t be used for prediction of weather conditions but it provides patterns of solar radiation in time comparable to those measured with pyranometer. Cloud layer simulation together with total solar radiation model is a useful tool for development and analysis of maximum power point tracking controllers for PV modules.

  14. Spectral and electronic measurements of solar radiation

    International Nuclear Information System (INIS)

    Suzuki, Mamoru; Hanyu, Mitsuhiro

    1977-01-01

    The spectral data of solar radiation are necessary if detailed discussion is intended in relation to the utilization of solar energy. Since those data have not been fully prepared so far, a measuring equipment developed in Electro-technical Laboratory to obtain those data is described. The laboratory is now continuing the measurement at the wavelength of 0.3 μm to 1.1 μm. The equipment employs the system to always calibrate with the standard light source, it can measure both the direct light of the sun only and the sun light including sky light, and it enables to obtain the value based on the secondary standard of spectral illumination intensity established by the laboratory. The solar spectral irradiance is determined with the current readings of photomultiplier in the standard light source and the sun-light measurements at a wavelength and with the spectral illumination intensity from the standard light source. In order to practice such measurement many times at various wavelengths, control of the equipment, data collection, computation, drawing and listing are performed by a microcomputer. As an example, the data on Sept. 10, 1976, are shown comparing the graphs at three different hours. It can be well observed that the transmissivity attenuates with shorter wavelength, and the transmissivity in near infra-red region changes greatly due to the absorption of radiation by water vapour. (Wakatsuki, Y.)

  15. Solar radiation on Mars: Stationary photovoltaic array

    Science.gov (United States)

    Appelbaum, J.; Sherman, I.; Landis, G. A.

    1993-01-01

    Solar energy is likely to be an important power source for surface-based operation on Mars. Photovoltaic cells offer many advantages. In this article we have presented analytical expressions and solar radiation data for stationary flat surfaces (horizontal and inclined) as a function of latitude, season and atmospheric dust load (optical depth). The diffuse component of the solar radiation on Mars can be significant, thus greatly affecting the optimal inclination angle of the photovoltaic surface.

  16. Tm2+ luminescent materials for solar radiation conversion devices

    NARCIS (Netherlands)

    Van der Kolk, E.

    2015-01-01

    A solar radiation conversion device is described that comprises a luminescent Tm 2+ inorganic material for converting solar radiation of at least part of the UV and/or visible and/or infra red solar spectrum into infrared solar radiation, preferably said infrared solar radiation having a wavelength

  17. Solar Radiation Forecasting, Accounting for Daily Variability

    Directory of Open Access Journals (Sweden)

    Roberto Langella

    2016-03-01

    Full Text Available Radiation forecast accounting for daily and instantaneous variability was pursued by means of a new bi-parametric statistical model that builds on a model previously proposed by the same authors. The statistical model is developed with direct reference to the Liu-Jordan clear sky theoretical expression but is not bound by a specific clear sky model; it accounts separately for the mean daily variability and for the variation of solar irradiance during the day by means of two corrective parameters. This new proposal allows for a better understanding of the physical phenomena and improves the effectiveness of statistical characterization and subsequent simulation of the introduced parameters to generate a synthetic solar irradiance time series. Furthermore, the analysis of the experimental distributions of the two parameters’ data was developed, obtaining opportune fittings by means of parametric analytical distributions or mixtures of more than one distribution. Finally, the model was further improved toward the inclusion of weather prediction information in the solar irradiance forecasting stage, from the perspective of overcoming the limitations of purely statistical approaches and implementing a new tool in the frame of solar irradiance prediction accounting for weather predictions over different time horizons.

  18. Turning collectors for solar radiation

    Science.gov (United States)

    Barak, Amitzur Z.

    1976-01-01

    A device is provided for turning a solar collector about the polar axis so that the collector is directed toward the sun as the sun tracks the sky each day. It includes two heat-expansive elements and a shadow plate. In the morning a first expansive element is heated, expands to turn the collector to face the sun, while the second expansive element is shaded by the plate. In the afternoon the second element is heated, expands to turn the collector to face the sun, while the first is shaded by the plate.

  19. Workshop Report on Managing Solar Radiation

    Science.gov (United States)

    Lane, Lee (Compiler); Caldeira, Ken (Compiler); Chatfield, Robert (Compiler); Langhoff, Stephanie (Compiler)

    2007-01-01

    The basic concept of managing Earth's radiation budget is to reduce the amount of incoming solar radiation absorbed by the Earth so as to counterbalance the heating of the Earth that would otherwise result from the accumulation of greenhouse gases. The workshop did not seek to decide whether or under what circumstances solar radiation management should be deployed or which strategies or technologies might be best, if it were deployed. Rather, the workshop focused on defining what kinds of information might be most valuable in allowing policy makers more knowledgeably to address the various options for solar radiation management.

  20. Radiation resistant passivation of silicon solar cells

    International Nuclear Information System (INIS)

    Swanson, R.M.; Gan, J.Y.; Gruenbaum, P.E.

    1991-01-01

    This patent describes a silicon solar cell having improved stability when exposed to concentrated solar radiation. It comprises a body of silicon material having a major surface for receiving radiation, a plurality of p and n conductivity regions in the body for collecting electrons and holes created by impinging radiation, and a passivation layer on the major surface including a first layer of silicon oxide in contact with the body and a polycrystalline silicon layer on the first layer of silicon oxide

  1. Predicted solar cell edge radiation effects

    International Nuclear Information System (INIS)

    Gates, M.T.

    1993-01-01

    The Advanced Solar Cell Orbital Test (ASCOT) will test six types of solar cells in a high energy proton environment. During the design of the experiment a question was raised about the effects of proton radiation incident on the edge of the solar cells and whether edge radiation shielding was required. Historical geosynchronous data indicated that edge radiation damage is not detectable over the normal end of life solar cell degradation; however because the ASCOT radiation environment has a much higher and more energetic fluence of protons, considerably more edge damage is expected. A computer analysis of the problem was made by modeling the expected radiation damage at the cell edge and using a network model of small interconnected solar cells to predict degradation in the cell's electrical output. The model indicated that the deepest penetration of edge radiation was at the top of the cell near the junction where the protons have access to the cell through the low density cell/cover adhesive layer. The network model indicated that the cells could tolerate high fluences at their edge as long as there was high electrical resistance between the edge radiated region and the contact system on top of the cell. The predicted edge radiation related loss was less than 2% of maximum power for GaAs/Ge solar cells. As a result, no edge radiation protection was used for ASCOT

  2. Estimation of solar radiation from Australian meterological observations

    International Nuclear Information System (INIS)

    Moriarty, W.W.

    1991-01-01

    A carefully prepared set of Australian radiation and meteorological data was used to develop a system for estimating hourly or instantaneous broad band direct, diffuse and global radiation from meteorological observations. For clear sky conditions relationships developed elsewhere were adapted to Australian data. For cloudy conditions the clouds were divided into two groups, high clouds and opaque (middle and low) clouds, and corrections were made to compensate for the bias due to reporting practices for almost clear and almost overcast skies. Careful consideration was given to the decrease of visible sky toward the horizon caused by the vertical extent of opaque clouds. Equations relating cloud and other meteorological observations to the direct and diffuse radiation contained four unknown quantities, functions of cloud amount and of solar elevation, which were estimated from the data. These were the proportions of incident solar radiation passed on as direct and as diffuse radiation by high clouds, and as diffuse radiation by opaque clouds, and a factor to describe the elevation dependence of the fraction of sky not obscured by opaque clouds. When the resulting relationships were used to estimate global, direct and diffuse radiation on a horizontal surface, the results were good, especially for global radiation. Some discrepancies between estimates and measurements of diffuse and direct radiation were probably due to erroneously high measurements of diffuse radiation

  3. Direct solar energy and its applications

    International Nuclear Information System (INIS)

    Hamdani, A.J.

    1997-01-01

    Solar energy, which was a utopian dream forty years ago, is today already on the market, particularly for specialized uses and in remote areas. Even solar cells are now on the eve of becoming economically competitive. After a brief account of solar-cell theory, this paper gives the essential details of Photovoltaic Module Manufacturing Technologies, Single Crystal Technology, Fabrication of Wafers, Fabrication of Solar Cell, Photovoltaic Module, Multi Crystalline Silicon, Amorphous Silicon Cell. Semi-conductor based Thin-Film Technology (other than silicon), Copper-Indium Di selenide (IS), Gallium Arsenide, Multi-Junction Devices, as well as Technologies for Improving Conversion Efficiencies, Criteria for high-efficiency Cells and Module Fabrication. It concludes with a section on Direct Utilisation of solar energy, in which a brief description is presented on Solar Thermal Devices, Solar Water Heaters, Calculating hot-water requirements, Solar Stills, Solar Drying, Concentrator Collectors and, finally Measurement of the Solar Resource. At the end, there is a useful Appendix on World-Wide Photovoltaic Cell/Module Manufacturing Capacity Expansion Profile. (author)

  4. Transmission coefficient of solar radiation in Manaus (AM-Brazil), in June

    International Nuclear Information System (INIS)

    Villa Nova, N.A.; Santos, J.M.; Goes Ribeiro, M.N.

    1976-01-01

    Global and diffuse solar radiation measurements, obtained by means of an Eppley pyrheliometer, were made two days in June 1975, one was clear day, (june, 11), and the other and overcast day (June, 19). The mean transmission coefficient for global and direct radiation were determined to be 0,81 and 0,70 respectively. The date on daily global solar radiation indicated that the values measured with the actinograph under estimate the real solar radiation values reaching the ground [pt

  5. High Radiation Resistance IMM Solar Cell

    Science.gov (United States)

    Pan, Noren

    2015-01-01

    Due to high launch costs, weight reduction is a key driver for the development of new solar cell technologies suitable for space applications. This project is developing a unique triple-junction inverted metamorphic multijunction (IMM) technology that enables the manufacture of very lightweight, low-cost InGaAsP-based multijunction solar cells. This IMM technology consists of indium (In) and phosphorous (P) solar cell active materials, which are designed to improve the radiation-resistant properties of the triple-junction solar cell while maintaining high efficiency. The intrinsic radiation hardness of InP materials makes them of great interest for building solar cells suitable for deployment in harsh radiation environments, such as medium Earth orbit and missions to the outer planets. NASA Glenn's recently developed epitaxial lift-off (ELO) process also will be applied to this new structure, which will enable the fabrication of the IMM structure without the substrate.

  6. Study of solar radiation prediction and modeling of relationships between solar radiation and meteorological variables

    International Nuclear Information System (INIS)

    Sun, Huaiwei; Zhao, Na; Zeng, Xiaofan; Yan, Dong

    2015-01-01

    Highlights: • We investigate relationships between solar radiation and meteorological variables. • A strong relationship exists between solar radiation and sunshine duration. • Daily global radiation can be estimated accurately with ARMAX–GARCH models. • MGARCH model was applied to investigate time-varying relationships. - Abstract: The traditional approaches that employ the correlations between solar radiation and other measured meteorological variables are commonly utilized in studies. It is important to investigate the time-varying relationships between meteorological variables and solar radiation to determine which variables have the strongest correlations with solar radiation. In this study, the nonlinear autoregressive moving average with exogenous variable–generalized autoregressive conditional heteroscedasticity (ARMAX–GARCH) and multivariate GARCH (MGARCH) time-series approaches were applied to investigate the associations between solar radiation and several meteorological variables. For these investigations, the long-term daily global solar radiation series measured at three stations from January 1, 2004 until December 31, 2007 were used in this study. Stronger relationships were observed to exist between global solar radiation and sunshine duration than between solar radiation and temperature difference. The results show that 82–88% of the temporal variations of the global solar radiation were captured by the sunshine-duration-based ARMAX–GARCH models and 55–68% of daily variations were captured by the temperature-difference-based ARMAX–GARCH models. The advantages of the ARMAX–GARCH models were also confirmed by comparison of Auto-Regressive and Moving Average (ARMA) and neutral network (ANN) models in the estimation of daily global solar radiation. The strong heteroscedastic persistency of the global solar radiation series was revealed by the AutoRegressive Conditional Heteroscedasticity (ARCH) and Generalized Auto

  7. Solar radiation alert system : final report.

    Science.gov (United States)

    2009-03-01

    The Solar Radiation Alert (SRA) system continuously evaluates measurements of high-energy protons made by instruments on GOES satellites. If the measurements indicate a substantial elevation of effective dose rates at aircraft flight altitudes, the C...

  8. The National Solar Radiation Database (NSRDB)

    Energy Technology Data Exchange (ETDEWEB)

    Sengupta, Manajit; Habte, Aron; Lopez, Anthony; Xie, Yu; Molling, Christine; Gueymard, Christian

    2017-03-13

    This presentation provides a high-level overview of the National Solar Radiation Database (NSRDB), including sensing, measurement and forecasting, and discusses observations that are needed for research and product development.

  9. The influence of the solar radiation model on the calcutated solar radiation from a horizontal surface to a tilted surface

    DEFF Research Database (Denmark)

    Andersen, Elsa; Lund, Hans; Furbo, Simon

    2004-01-01

    Measured solar radiation data are most commonly available as total solar radiation on a horizontal surface. When using solar radiation measured on horizontal to calculate the solar radiation on tilted surfaces and thereby the thermal performance of different applications such as buildings and solar...... heating systems, different solar radiation models can be used. The calculation of beam radiation from a horizontal surface to a tilted surface can be done exactly whereas different solar radiation models can calculate the sky diffuse radiation. The sky diffuse radiation can either be assumed evenly...... in the calculation. The weather data are measured at the solar radiation measurement station, SMS at the Department of Civil Engineering at the Technical University of Denmark. In this study the weather data are combined with solar collector calculations based on solar collector test carried out at Solar Energy...

  10. Increase of solar radiation due to climate change and its impact on solar energy use

    International Nuclear Information System (INIS)

    Kuhnke, K.; Rahme, A.; Harling, J.; Arensmann, R.

    2008-01-01

    Full text: There is a significant change in solar radiation in Central Europe coinciding with the IPCC climate change model calculations. The increase of yearly solar radiation on the horizontal surface is about 0.38 percent/year. On the other hand, photovoltaic solar modules show an ageing effect of the same order of magnitude, i.e. a reduction of yearly energy yield between 0.3 and 0.5 percent/year. This reduction is normally taken into account in economic calculations such as payback time and internal rate of interest. As the two trends of increase in radiation and ageing of solar modules are in opposite direction to each other, they will - with their uncertainties - neutralize one another to zero. Thus, the energy production of photovoltaic systems can be calculated without any deductions due to ageing in the future. (authors)

  11. A sensor element for direct radiation measurement

    Energy Technology Data Exchange (ETDEWEB)

    Bajons, P.; Wernhart, U.; Zeiler, H. [University of Vienna (Austria). Institut of Material Physics

    1998-08-01

    A combination of a photodiode with a nonimaging light concentrator is developed to perform measurements of the direct solar radiation component. A prototype composed of low price elements is taken as a starting point to discuss the problems which must be faced when calibrating such sensors. By this the influence of the angle of incidence and spectral distribution (caused by different air mass or varying degree of clearness) of the incident radiation on the behavior of the system is studied. The readings are compared to the calculated (global minus diffuse) readings obtained from two standard star pyranometers. Finally the possibilities for increasing the accuracy of the sensor element and for applying the device are discussed. (author)

  12. Design of direct solar PV driven air conditioner

    KAUST Repository

    Huang, Bin-Juine

    2015-12-05

    © 2015 Elsevier Ltd. Solar air conditioning system directly driven by stand-alone solar PV is studied. The air conditioning system will suffer from loss of power if the solar PV power generation is not high enough. It requires a proper system design to match the power consumption of air conditioning system with a proper PV size. Six solar air conditioners with different sizes of PV panel and air conditioners were built and tested outdoors to experimentally investigate the running probabilities of air conditioning at various solar irradiations. It is shown that the instantaneous operation probability (OPB) and the runtime fraction (RF) of the air conditioner are mainly affected by the design parameter rpL (ratio of maximum PV power to load power). The measured OPB is found to be greater than 0.98 at instantaneous solar irradiation IT > 600 W m-2 if rpL > 1.71 RF approaches 1.0 (the air conditioner is run in 100% with solar power) at daily-total solar radiation higher than 13 MJ m-2 day-1, if rpL > 3.

  13. Solar Radiation and Climate Experiment (SORCE) Satellite

    Science.gov (United States)

    2003-01-01

    This is a close-up of the NASA-sponsored Solar Radiation and Climate Experiment (SORCE) Satellite. The SORCE mission, launched aboard a Pegasus rocket January 25, 2003, will provide state of the art measurements of incoming x-ray, ultraviolet, visible, near-infrared, and total solar radiation. Critical to studies of the Sun and its effect on our Earth system and mankind, SORCE will provide measurements that specifically address long-term climate change, natural variability and enhanced climate prediction, and atmospheric ozone and UV-B radiation. Orbiting around the Earth accumulating solar data, SORCE measures the Sun's output with the use of state-of-the-art radiometers, spectrometers, photodiodes, detectors, and bolo meters engineered into instruments mounted on a satellite observatory. SORCE is carrying 4 instruments: The Total Irradiance Monitor (TIM); the Solar Stellar Irradiance Comparison Experiment (SOLSTICE); the Spectral Irradiance Monitor (SIM); and the XUV Photometer System (XPS).

  14. Solar radiation at Parsons, West Virginia

    Science.gov (United States)

    James H. Patric; Stanley Caruso

    1978-01-01

    Twelve years of solar radiation data, measured with a Kipp-Zonen pyranometer, were recorded near Parsons, West Virginia. The data agree well with calculated values of potential and average radiation for the vicinity and are applicable to the central Appalachian region.

  15. A Model for Hourly Solar Radiation Data Generation from Daily Solar Radiation Data Using a Generalized Regression Artificial Neural Network

    OpenAIRE

    Khatib, Tamer; Elmenreich, Wilfried

    2015-01-01

    This paper presents a model for predicting hourly solar radiation data using daily solar radiation averages. The proposed model is a generalized regression artificial neural network. This model has three inputs, namely, mean daily solar radiation, hour angle, and sunset hour angle. The output layer has one node which is mean hourly solar radiation. The training and development of the proposed model are done using MATLAB and 43800 records of hourly global solar radiation. The results show that...

  16. Solar radiation estimation based on the insolation

    International Nuclear Information System (INIS)

    Assis, F.N. de; Steinmetz, S.; Martins, S.R.; Mendez, M.E.G.

    1998-01-01

    A series of daily global solar radiation data measured by an Eppley pyranometer was used to test PEREIRA and VILLA NOVA’s (1997) model to estimate the potential of radiation based on the instantaneous values measured at solar noon. The model also allows to estimate the parameters of PRESCOTT’s equation (1940) assuming a = 0,29 cosj. The results demonstrated the model’s validity for the studied conditions. Simultaneously, the hypothesis of generalizing the use of the radiation estimative formulas based on insolation, and using K = Ko (0,29 cosj + 0,50 n/N), was analysed and confirmed [pt

  17. Orbiter radiator panel solar focusing test

    Science.gov (United States)

    Howell, H. R.; Rankin, J. G.

    1983-01-01

    Test data are presented which define the area around the Orbiter radiator panels for which the solar reflections are concentrated to one-sun or more. The concave shape of the panels and their specular silver/Teflon coating causes focusing of the reflected solar energy which could have adverse heating effects on equipment or astronaut extravehicular activity (EVA) in the vicinity of the radiator panels. A room ambient test method was utilized with a one-tenth scale model of the radiator panels.

  18. Solar Radiation effect on the bituminous binder

    International Nuclear Information System (INIS)

    Tadeo Rico, A.; Torres Perez, A.

    2010-01-01

    Asphalt, used as binder in road construction, becomes more brittle and harder during working life on the surface of the road pavement, conducting toward their deterioration. This is caused by the oxidation of the molecular functional groups of the asphalt molecular structure. Moreover, it is observed that ultraviolet radiation increases the oxidation process. However, the effect of solar light on the asphalt degradation has been poorly researched. The aim of this work is to study asphalt ageing caused by effect of solar radiation, by using standard test. Four commercial asphalts from different companies were selected: two with penetration number 50/70, and the other two polymer modified asphalts. From each of the asphalts forty samples were taken off and placed in four different aging conditions of temperature and radiation for a period ranging from 40 to 500 days. Ring and Ball test, and Fraass breaking Point test, were used to analyse the changes of asphalt properties after exposition to solar radiation. The results of the four analyzed asphalts showed a distinct behaviour; not only in the test temperature increase but also in the rate. Another experiment was carried out. Samples from a hot mix asphalt batch were placed under solar radiation, and were compacted by the Marshall procedure after increasing periods of time. Density and resistance to plastic flow using Marshall Apparatus were measured. Results showed an increase in the stability of samples under radiation. Both experiments show that the solar radiation is enough to cause changes in the asphalt molecular structure due to oxidation. So that, the study of the effect of the solar radiation on the asphalt properties could be a good tool to asses the performances of asphalt pavement. (Author) 26 refs.

  19. Models for prediction of global solar radiation on horizontal surface ...

    African Journals Online (AJOL)

    The estimation of global solar radiation continues to play a fundamental role in solar engineering systems and applications. This paper compares various models for estimating the average monthly global solar radiation on horizontal surface for Akure, Nigeria, using solar radiation and sunshine duration data covering years ...

  20. Radiation From Solar Activity | Radiation Protection | US EPA

    Science.gov (United States)

    2017-08-07

    Solar flares, coronal mass ejections (CMEs) and geomagnetic storms from the sun can send extreme bursts of ionizing radiation and magnetic energy toward Earth. Some of this energy is in the form ionizing radiation and some of the energy is magnetic energy.

  1. Obliquity Modulation of the Incoming Solar Radiation

    Science.gov (United States)

    Liu, Han-Shou; Smith, David E. (Technical Monitor)

    2001-01-01

    Based on a basic principle of orbital resonance, we have identified a huge deficit of solar radiation induced by the combined amplitude and frequency modulation of the Earth's obliquity as possibly the causal mechanism for ice age glaciation. Including this modulation effect on solar radiation, we have performed model simulations of climate change for the past 2 million years. Simulation results show that: (1) For the past 1 million years, temperature fluctuation cycles were dominated by a 100-Kyr period due to amplitude-frequency resonance effect of the obliquity; (2) From 2 to 1 million years ago, the amplitude-frequency interactions. of the obliquity were so weak that they were not able to stimulate a resonance effect on solar radiation; (3) Amplitude and frequency modulation analysis on solar radiation provides a series of resonance in the incoming solar radiation which may shift the glaciation cycles from 41-Kyr to 100-Kyr about 0.9 million years ago. These results are in good agreement with the marine and continental paleoclimate records. Thus, the proposed climate response to the combined amplitude and frequency modulation of the Earth's obliquity may be the key to understanding the glaciation puzzles in paleoclimatology.

  2. Solar Radiation Research Laboratory | Energy Systems Integration Facility |

    Science.gov (United States)

    Solar Radiation Research Laboratory (SRRL) has been collecting continuous measurements of basic solar continuous operation. More than 75 instruments contribute to the Baseline Measurement System by recording

  3. Measuring Solar Radiation Incident on Earth: Solar Constant-3 (SOLCON-3)

    Science.gov (United States)

    Crommelynck, Dominique; Joukoff, Alexandre; Dewitte, Steven

    2002-01-01

    Life on Earth is possible because the climate conditions on Earth are relatively mild. One element of the climate on Earth, the temperature, is determined by the heat exchanges between the Earth and its surroundings, outer space. The heat exchanges take place in the form of electromagnetic radiation. The Earth gains energy because it absorbs solar radiation, and it loses energy because it emits thermal infrared radiation to cold space. The heat exchanges are in balance: the heat gained by the Earth through solar radiation equals the heat lost through thermal radiation. When the balance is perturbed, a temperature change and hence a climate change of the Earth will occur. One possible perturbation of the balance is the CO2 greenhouse effect: when the amount of CO2 in the atmosphere increases, this will reduce the loss of thermal infrared radiation to cold space. Earth will gain more heat and hence the temperature will rise. Another perturbation of the balance can occur through variation of the amount of energy emitted by the sun. When the sun emits more energy, this will directly cause a rise of temperature on Earth. For a long time scientists believed that the energy emitted by the sun was constant. The 'solar constant' is defined as the amount of solar energy received per unit surface at a distance of one astronomical unit (the average distance of Earth's orbit) from the sun. Accurate measurements of the variations of the solar constant have been made since 1978. From these we know that the solar constant varies approximately with the 11-year solar cycle observed in other solar phenomena, such as the occurrence of sunspots, dark spots that are sometimes visible on the solar surface. When a sunspot occurs on the sun, since the spot is dark, the radiation (light) emitted by the sun drops instantaneously. Oddly, periods of high solar activity, when a lot of sunspot numbers increase, correspond to periods when the average solar constant is high. This indicates that

  4. Solar Radiation on Mars: Tracking Photovoltaic Array

    Science.gov (United States)

    Appelbaum, Joseph; Flood, Dennis J.; Crutchik, Marcos

    1994-01-01

    A photovoltaic power source for surface-based operation on Mars can offer many advantages. Detailed information on solar radiation characteristics on Mars and the insolation on various types of collector surfaces are necessary for effective design of future planned photovoltaic systems. In this article we have presented analytical expressions for solar radiation calculation and solar radiation data for single axis (of various types) and two axis tracking surfaces and compared the insulation to horizontal and inclined surfaces. For clear skies (low atmospheric dust load) tracking surfaces resulted in higher insolation than stationary surfaces, whereas for highly dusty atmospheres, the difference is small. The insolation on the different types of stationary and tracking surfaces depend on latitude, season and optical depth of the atmosphere, and the duration of system operation. These insolations have to be compared for each mission.

  5. A solar radiation database for Chile.

    Science.gov (United States)

    Molina, Alejandra; Falvey, Mark; Rondanelli, Roberto

    2017-11-01

    Chile hosts some of the sunniest places on earth, which has led to a growing solar energy industry in recent years. However, the lack of high resolution measurements of solar irradiance becomes a critical obstacle for both financing and design of solar installations. Besides the Atacama Desert, Chile displays a large array of "solar climates" due to large latitude and altitude variations, and so provides a useful testbed for the development of solar irradiance maps. Here a new public database for surface solar irradiance over Chile is presented. This database includes hourly irradiance from 2004 to 2016 at 90 m horizontal resolution over continental Chile. Our results are based on global reanalysis data to force a radiative transfer model for clear sky solar irradiance and an empirical model based on geostationary satellite data for cloudy conditions. The results have been validated using 140 surface solar irradiance stations throughout the country. Model mean percentage error in hourly time series of global horizontal irradiance is only 0.73%, considering both clear and cloudy days. The simplicity and accuracy of the model over a wide range of solar conditions provides confidence that the model can be easily generalized to other regions of the world.

  6. PSA Solar furnace: A facility for testing PV cells under concentrated solar radiation

    Energy Technology Data Exchange (ETDEWEB)

    Fernandez-Reche, J.; Canadas, I.; Sanchez, M.; Ballestrin, J.; Yebra, L.; Monterreal, R.; Rodriguez, J.; Garcia, G. [Concentration Solar Technologies, Plataforma Solar de Almeria-CIEMAT P.O. Box 22, Tabernas, E-04200 (Almeria) (Spain); Alonso, M.; Chenlo, F. [Photovoltaic Components and Systems, Renewable Energies Department-CIEMAT Avda. Complutense, 22, Madrid, E-28040 (Spain)

    2006-09-22

    The Plataforma Solar de Almeria (PSA), the largest centre for research, development and testing of concentration solar thermal technologies in Europe, has started to apply its knowledge, facilities and resources to development of the Concentration PV technology in an EU-funded project HiConPV. A facility for testing PV cells under solar radiation concentrated up to 2000x has recently been completed. The advantages of this facility are that, since it is illuminated by solar radiation, it is possible to obtain the appropriate cell spectral response directly, and the flash tests can be combined with prolonged PV-cell irradiation on large surfaces (up to 150cm{sup 2}), so the thermal response of the PV cell can be evaluated simultaneously. (author)

  7. Measurement tolerance analysis of solar radiation

    Energy Technology Data Exchange (ETDEWEB)

    Cimo, J.; Maderkova, L.; Horak, J.; Igaz, D.; Pasztorova, S. [Department of Biomereorlogy and Hydrology, Slovak Agriculture University, Nitra (Slovakia)

    2012-07-01

    Solar radiant energy is bane and almost the only one source of heat for Earth 's surface and for atmosphere, and almost the only one source of energy for physical processes. Solar energy is one of the most available and the most ecological energy source. Currently the firm Kipp and Zonen belongs to prominent producer of sensors for measuring of global radiation. These sensors are the most used in our country and also in network of meteorological measurements of WMO. Therefore the two types of measuring sensors for global radiation (pyranometer PMP6, CMP 11) in comparison with calculation method Savin-Angstrom are analysed. (author)

  8. Mathematical Modeling and Numerical Analysis of Thermal Distribution in Arch Dams considering Solar Radiation Effect

    Science.gov (United States)

    Mirzabozorg, H.; Hariri-Ardebili, M. A.; Shirkhan, M.; Seyed-Kolbadi, S. M.

    2014-01-01

    The effect of solar radiation on thermal distribution in thin high arch dams is investigated. The differential equation governing thermal behavior of mass concrete in three-dimensional space is solved applying appropriate boundary conditions. Solar radiation is implemented considering the dam face direction relative to the sun, the slop relative to horizon, the region cloud cover, and the surrounding topography. It has been observed that solar radiation changes the surface temperature drastically and leads to nonuniform temperature distribution. Solar radiation effects should be considered in thermal transient analysis of thin arch dams. PMID:24695817

  9. Mathematical modeling and numerical analysis of thermal distribution in arch dams considering solar radiation effect.

    Science.gov (United States)

    Mirzabozorg, H; Hariri-Ardebili, M A; Shirkhan, M; Seyed-Kolbadi, S M

    2014-01-01

    The effect of solar radiation on thermal distribution in thin high arch dams is investigated. The differential equation governing thermal behavior of mass concrete in three-dimensional space is solved applying appropriate boundary conditions. Solar radiation is implemented considering the dam face direction relative to the sun, the slop relative to horizon, the region cloud cover, and the surrounding topography. It has been observed that solar radiation changes the surface temperature drastically and leads to nonuniform temperature distribution. Solar radiation effects should be considered in thermal transient analysis of thin arch dams.

  10. Production of solar radiation bankable datasets from high-resolution solar irradiance derived with dynamical downscaling Numerical Weather prediction model

    Directory of Open Access Journals (Sweden)

    Yassine Charabi

    2016-11-01

    Full Text Available A bankable solar radiation database is required for the financial viability of solar energy project. Accurate estimation of solar energy resources in a country is very important for proper siting, sizing and life cycle cost analysis of solar energy systems. During the last decade an important progress has been made to develop multiple solar irradiance database (Global Horizontal Irradiance (GHI and Direct Normal Irradiance (DNI, using satellite of different resolution and sophisticated models. This paper assesses the performance of High-resolution solar irradiance derived with dynamical downscaling Numerical Weather Prediction model with, GIS topographical solar radiation model, satellite data and ground measurements, for the production of bankable solar radiation datasets. For this investigation, NWP model namely Consortium for Small-scale Modeling (COSMO is used for the dynamical downscaling of solar radiation. The obtained results increase confidence in solar radiation data base obtained from dynamical downscaled NWP model. The mean bias of dynamical downscaled NWP model is small, on the order of a few percents for GHI, and it could be ranked as a bankable datasets. Fortunately, these data are usually archived in the meteorological department and gives a good idea of the hourly, monthly, and annual incident energy. Such short time-interval data are valuable in designing and operating the solar energy facility. The advantage of the NWP model is that it can be used for solar radiation forecast since it can estimate the weather condition within the next 72–120 hours. This gives a reasonable estimation of the solar radiation that in turns can be used to forecast the electric power generation by the solar power plant.

  11. SOLAR RADIATION MAPS FOR EIIDOPIA Tesfaye Bayou and ...

    African Journals Online (AJOL)

    day-1, thus signifying the solar power potential ... data are available only for few places due to the high cost of ... the mean daily global solar radiation for Ethiopia ... wind speed and precipitation. ..... Insolation on Tilted Surfaces, Solar Energy,.

  12. Distributed solar radiation fast dynamic measurement for PV cells

    Science.gov (United States)

    Wan, Xuefen; Yang, Yi; Cui, Jian; Du, Xingjing; Zheng, Tao; Sardar, Muhammad Sohail

    2017-10-01

    need of complex local installations, configuring of our SRMA system is very easy. Lora also provides SRMA a means to overcome the short communication distance and weather signal propagation decline such as in ZigBee and WiFi. The host computer in SRMA system uses the low power single-board PC EMB-3870 which was produced by NORCO. Wind direction sensor SM5386B and wind-force sensor SM5387B are installed to host computer through RS-485 bus for wind reference data collection. And Davis 6450 solar radiation sensor, which is a precision instrument that detects radiation at wavelengths of 300 to 1100 nanometers, allow host computer to follow real-time solar radiation. A LoRa polling scheme is adopt for the communication between host computer and terminal nodes in SRMA. An experimental SRMA has been established. This system was tested in Ganyu, Jiangshu province from May to August, 2016. In the test, the distances between the nodes and the host computer were between 100m and 1900m. At work, SRMA system showed higher reliability. Terminal nodes could follow the instructions from host computer and collect solar radiation data of distributed PV cells effectively. And the host computer managed the SRAM and achieves reference parameters well. Communications between the host computer and terminal nodes were almost unaffected by the weather. In conclusion, the testing results show that SRMA could be a capable method for fast dynamic measuring about solar radiation and related PV cell operating characteristics.

  13. Solar and terrestrial radiation: methods and measurements

    National Research Council Canada - National Science Library

    Coulson, Kinsell L

    1975-01-01

    ... AND RETRIEVAL SYSTEM, WITHOUT PERMISSION IN WRITING FROM THE PUBLISHER. ACADEMIC PRESS, INC. Ill Fifth Avenue, New York, New York 10003 United Kingdom Edition published by A C A D E M I C PRESS, INC. (LONDON) LTD. 24/28 Oval Road, London NW1 Library of Congress Cataloging in Publication Data Coulson, Kinsell L Solar and terrestrial radiation. Inclu...

  14. Solar radiation observation stations updated to 1979

    Energy Technology Data Exchange (ETDEWEB)

    Carter, E.A.; Cristina, J.R.; Williams, B.B.

    1979-04-01

    The type of sensing and recording equipment for 420 stations in the US are listed alphabetically by states. The stations are divided according to whether or not they are in the basic National Weather Service, NOAA, network. Reports of summarized solar radiation data are listed in an appendix. (MHR)

  15. MODELING ACUTE EXPOSURE TO SOLAR RADIATION

    Science.gov (United States)

    One of the major technical challenges in calculating solar flux on the human form has been the complexity of the surface geometry (i.e., the surface normal vis a vis the incident radiation). The American Cancer Society reports that over 80% of skin cancers occur on the face, he...

  16. Evaluation of conventional and high-performance routine solar radiation measurements for improved solar resource, climatological trends, and radiative modeling

    Energy Technology Data Exchange (ETDEWEB)

    Gueymard, Christian A. [Solar Consulting Services, P.O. Box 392, Colebrook, NH 03576 (United States); Myers, Daryl R. [National Renewable Energy Laboratory, 1617 Cole Blvd., Golden, CO 80401-3305 (United States)

    2009-02-15

    The solar renewable energy community depends on radiometric measurements and instrumentation for data to design and monitor solar energy systems, and develop and validate solar radiation models. This contribution evaluates the impact of instrument uncertainties contributing to data inaccuracies and their effect on short-term and long-term measurement series, and on radiation model validation studies. For the latter part, transposition (horizontal-to-tilt) models are used as an example. Confirming previous studies, it is found that a widely used pyranometer strongly underestimates diffuse and global radiation, particularly in winter, unless appropriate corrective measures are taken. Other types of measurement problems are also discussed, such as those involved in the indirect determination of direct or diffuse irradiance, and in shadowband correction methods. The sensitivity of the predictions from transposition models to inaccuracies in input radiation data is demonstrated. Caution is therefore issued to the whole community regarding drawing detailed conclusions about solar radiation data without due attention to the data quality issues only recently identified. (author)

  17. Solar cell radiation handbook. Addendum 1: 1982-1988

    International Nuclear Information System (INIS)

    Anspaugh, B.E.

    1989-02-01

    The Solar Cell Radiation Handbook (JPL Publication 82-69) is updated. In order to maintain currency of solar cell radiation data, recent solar cell designs have been acquired, irradiated with 1 MeV electrons, and measured. The results of these radiation experiments are reported

  18. Radiative origins of the solar corona

    International Nuclear Information System (INIS)

    Koch, P.

    1978-01-01

    Within observational accuracy, the radiation pressure aT 4 /3 at the effective solar temperature is equal to the coronal gas pressure nkT. This suggests a radiative gas discontinuity between optically thick and optically thin regions. Ideal transitions of this nature are studied and the applicability of this model to the Sun is explored. Further empirical corroboration is obtained if the gas pressure anomalies of Gulyaev are resolved by postulating a corrective gradient of radiation pressure possibly caused by Lyman-α opacity. (Auth.)

  19. Radiation balances and the solar constant

    Science.gov (United States)

    Crommelynck, D.

    1981-01-01

    The radiometric concepts are defined in order to consider various types of radiation balances and relate them to the diabetic form of the energy balance. Variability in space and time of the components of the radiation field are presented. A specific concept for sweeping which is tailored to the requirements is proposed. Finally, after establishing the truncated character of the present knowledge of the radiation balance. The results of the last observations of the solar constant are given. Ground and satellite measurement techniques are discussed.

  20. solaR: Solar Radiation and Photovoltaic Systems with R

    Directory of Open Access Journals (Sweden)

    Oscar Perpiñan Lamigueiro

    2012-08-01

    Full Text Available The solaR package allows for reproducible research both for photovoltaics (PV systems performance and solar radiation. It includes a set of classes, methods and functions to calculate the sun geometry and the solar radiation incident on a photovoltaic generator and to simulate the performance of several applications of the photovoltaic energy. This package performs the whole calculation procedure from both daily and intradaily global horizontal irradiation to the final productivity of grid-connected PV systems and water pumping PV systems.It is designed using a set of S4 classes whose core is a group of slots with multivariate time series. The classes share a variety of methods to access the information and several visualization methods. In addition, the package provides a tool for the visual statistical analysis of the performance of a large PV plant composed of several systems.Although solaR is primarily designed for time series associated to a location defined by its latitude/longitude values and the temperature and irradiation conditions, it can be easily combined with spatial packages for space-time analysis.

  1. Digging the METEOSAT Treasure—3 Decades of Solar Surface Radiation

    Directory of Open Access Journals (Sweden)

    Richard Müller

    2015-06-01

    Full Text Available Solar surface radiation data of high quality is essential for the appropriate monitoring and analysis of the Earth's radiation budget and the climate system. Further, they are crucial for the efficient planning and operation of solar energy systems. However, well maintained surface measurements are rare in many regions of the world and over the oceans. There, satellite derived information is the exclusive observational source. This emphasizes the important role of satellite based surface radiation data. Within this scope, the new satellite based CM-SAF SARAH (Solar surfAce RAdiation Heliosat data record is discussed as well as the retrieval method used. The SARAH data are retrieved with the sophisticated SPECMAGIC method, which is based on radiative transfer modeling. The resulting climate data of solar surface irradiance, direct irradiance (horizontal and direct normal and clear sky irradiance are covering 3 decades. The SARAH data set is validated with surface measurements of the Baseline Surface Radiation Network (BSRN and of the Global Energy and Balance Archive (GEBA. Comparison with BSRN data is performed in order to estimate the accuracy and precision of the monthly and daily means of solar surface irradiance. The SARAH solar surface irradiance shows a bias of 1.3 \\(W/m^2\\ and a mean absolute bias (MAB of 5.5 \\(W/m^2\\ for monthly means. For direct irradiance the bias and MAB is 1 \\(W/m^2\\ and 8.2 \\(W/m^2\\ respectively. Thus, the uncertainty of the SARAH data is in the range of the uncertainty of ground based measurements. In order to evaluate the uncertainty of SARAH based trend analysis the time series of SARAH monthly means are compared to GEBA. It has been found that SARAH enables the analysis of trends with an uncertainty of 1 \\(W/m^2/dec\\; a remarkable good result for a satellite based climate data record. SARAH has been also compared to its legacy version, the satellite based CM-SAF MVIRI climate data record. Overall

  2. Direct solar-pumped iodine laser amplifier

    Science.gov (United States)

    Han, Kwang S.

    1987-01-01

    This semiannual progress report covers the period from March 1, 1987 to September 30, 1987 under NASA grant NAG1-441 entitled 'Direct solar-pumped iodine laser amplifier'. During this period Nd:YAG and Nd:Cr:GSGG crystals have been tested for the solar-simulator pumped cw laser, and loss mechanisms of the laser output power in a flashlamp-pumped iodine laser also have been identified theoretically. It was observed that the threshold pump-beam intensities for both Nd:YAG and Nd:Cr:GSGG crystals were about 1000 solar constants, and the cw laser operation of the Nd:Cr:GSGG crystal was more difficult than that of the Nd:YAG crystal under the solar-simulator pumping. The possibility of the Nd:Cr:GSGG laser operation with a fast continuously chopped pumping was also observed. In addition, good agreement between the theoretical calculations and the experimental data on the loss mechanisms of a flashlamp-pumped iodine laser at various fill pressures and various lasants was achieved.

  3. Solar radiation and mitochondrial DNA damage

    International Nuclear Information System (INIS)

    Hill, H.Z.; Locitzer, J.; Nassrin, E.; Ogbonnaya, A.; Hubbard, K.

    2003-01-01

    The 16.6 kB human mitochondrial DNA contains two homologous 13 base pair direct repeats separated by about 5 kB. During asynchronous mitochondrial DNA replication, the distant repeat sequences are thought to anneal, resulting in the looping out of a portion of the non-template strand which is subsequently deleted as a result of interaction with reactive oxygen species (ROS). A normal daughter and a deleted daughter mitochondrion result from such insults. This deletion has been termed the common deletion as it is the most frequent of the known mitochondrial DNA deletions. The common deletion is present in high frequency in several mitochondrial disorders, accumulates with age in slow turnover tissues and is increased in sun-exposed skin. Berneburg, et al. (Photochem. Photobiol. 66: 271, 1997) induced the common deletion in normal human fibroblasts after repeated exposures to UVA. In this study, the common deletion has been shown to be induced by repeated non-lethal exposures to FS20 sunlamp irradiation. Increases in the common deletion were demonstrated using nested PCR which produced a 303 bp product that was compared to a 324 bp product that required the presence of the undeleted 5 kB region. The cells were exposed to 10 repeated doses ranging from 0.5 (UVB) - 0.24 (UVA) J/sq m to 14.4 (UVB) - 5.8 J/sq m (UVA) measured using a UVX digital radiometer and UVB and UVA detectors respectively. Comparison with the earlier study by Berneberg, et al. suggests that this type of simulated solar damage is considerably more effective in fewer exposures than UVA radiation alone. The common deletion provides a cytoplasmic end-point for ROS damage produced by low dose chronic irradiations and other low level toxic exposures and should prove useful in evaluating cytoplasmic damage produced by ionizing radiation as well

  4. Spatially Refined Aerosol Direct Radiative Forcing Efficiencies

    Science.gov (United States)

    Global aerosol direct radiative forcing (DRF) is an important metric for assessing potential climate impacts of future emissions changes. However, the radiative consequences of emissions perturbations are not readily quantified nor well understood at the level of detail necessary...

  5. NRC TLD Direct Radiation Monitoring Network

    International Nuclear Information System (INIS)

    Struckmeyer, R.; McNamara, N.

    1991-12-01

    This report provides the status and results of the NRC Thermoluminescent Dosimeter (TLD) Direct Radiation Monitoring Network. It presents the radiation levels measured in the vicinity of NRC licensed facilities throughout the country for the third quarter of 1991

  6. A solar simulator-pumped gas laser for the direct conversion of solar energy

    Science.gov (United States)

    Weaver, W. R.; Lee, J. H.

    1981-01-01

    Most proposed space power systems are comprised of three general stages, including the collection of the solar radiation, the conversion to a useful form, and the transmission to a receiver. The solar-pumped laser, however, effectively eliminates the middle stage and offers direct photon-to-photon conversion. The laser is especially suited for space-to-space power transmission and communication because of minimal beam spread, low power loss over large distances, and extreme energy densities. A description is presented of the first gas laser pumped by a solar simulator that is scalable to high power levels. The lasant is an iodide C3F7I that as a laser-fusion driver has produced terawatt peak power levels.

  7. Solar ultraviolet radiation from cancer induction to cancer prevention: solar ultraviolet radiation and cell biology.

    Science.gov (United States)

    Tuorkey, Muobarak J

    2015-09-01

    Although decades have elapsed, researchers still debate the benefits and hazards of solar ultraviolet radiation (UVR) exposure. On the one hand, humans derive most of their serum 25-hydroxycholecalciferol [25(OH)D3], which has potent anticancer activity, from solar UVB radiation. On the other hand, people are more aware of the risk of cancer incidence associated with harmful levels of solar UVR from daily sunlight exposure. Epidemiological data strongly implicate UV radiation exposure as a major cause of melanoma and other cancers, as UVR promotes mutations in oncogenes and tumor-suppressor genes. This review highlights the impact of the different mutagenic effects of solar UVR, along with the cellular and carcinogenic challenges with respect to sun exposure.

  8. Placement and efficiency effects on radiative forcing of solar installations

    International Nuclear Information System (INIS)

    Burg, Brian R.; Ruch, Patrick; Paredes, Stephan; Michel, Bruno

    2015-01-01

    The promise for harnessing solar energy being hampered by cost, triggered efforts to reduce them. As a consequence low-efficiency, low-cost photovoltaics (PV) panels prevail. Conversely, in the traditional energy sector efficiency is extremely important due to the direct costs associated to fuels. This also affects solar energy due to the radiative forcing caused by the dark solar panels. In this paper we extend the concept of energy payback time by including the effect of albedo change, which gives a better assessment of the system sustainability. We present an analysis on the short and medium term climate forcing effects of different solar collectors in Riyadh, Saudi Arabia and demonstrate that efficiency is important to reduce the collector area and cost. This also influences the embodied energy and the global warming potential. We show that a placement of a high concentration photovoltaic thermal solar power station outside of the city using a district cooling system has a double beneficial effect since it improves the solar conversion efficiency and reduces the energy demand for cooling in the city. We also explain the mechanisms of the current economic development of solar technologies and anticipate changes

  9. Placement and efficiency effects on radiative forcing of solar installations

    Energy Technology Data Exchange (ETDEWEB)

    Burg, Brian R.; Ruch, Patrick; Paredes, Stephan; Michel, Bruno, E-mail: bmi@zurich.ibm.com [IBM Research - Zurich, Säumerstrasse 4, CH-8803 Rüschlikon (Switzerland)

    2015-09-28

    The promise for harnessing solar energy being hampered by cost, triggered efforts to reduce them. As a consequence low-efficiency, low-cost photovoltaics (PV) panels prevail. Conversely, in the traditional energy sector efficiency is extremely important due to the direct costs associated to fuels. This also affects solar energy due to the radiative forcing caused by the dark solar panels. In this paper we extend the concept of energy payback time by including the effect of albedo change, which gives a better assessment of the system sustainability. We present an analysis on the short and medium term climate forcing effects of different solar collectors in Riyadh, Saudi Arabia and demonstrate that efficiency is important to reduce the collector area and cost. This also influences the embodied energy and the global warming potential. We show that a placement of a high concentration photovoltaic thermal solar power station outside of the city using a district cooling system has a double beneficial effect since it improves the solar conversion efficiency and reduces the energy demand for cooling in the city. We also explain the mechanisms of the current economic development of solar technologies and anticipate changes.

  10. Establishment and verification of solar radiation calculation model of glass daylighting roof in hot summer and warm winter zone in China

    OpenAIRE

    Zheng, Caidan; Wu, Peihao; Costanzo, Vincenzo; Wang, Yuchen; Yang, Xiaokun

    2017-01-01

    In this paper, solar heat gain through glass daylighting roof is deeply studied by theoretical calculation method, taking Guangzhou in the Hot Summer and Warm Winter (HSWW) zone as an example. The direct solar radiation is calculated by Bouguer formula whereas the diffuse solar radiation is calculated by Berlage formula, representing the basis for the calculation method of the solar radiation intensity through the glass daylighting roof. Through the establishment of solar radiation calculatio...

  11. INSTRUMENTATION FOR MEASURING AND TRANSMISSION THE SOLAR RADIATION THROUGH EARTH’S ATMOSPHERE

    Directory of Open Access Journals (Sweden)

    Alexandru Dan Toma

    2013-07-01

    Full Text Available The Sun's energy is distributed over a broad range of the electromagnetic spectrum and Sun behaves approximately like a "blackbody" radiating at a temperature of about 5800 K with maximum output in the green-yellow part of the visible spectrum, around 500 nm. Not all solar radiation reaching the top of the atmosphere reaches Earth's surface due to a various optical phenomena in regard to solar radiation crossing the Earth’s atmosphere. In order to investigate them, there are two general categories of instruments used to measure the transmission of solar radiation through Earth's atmosphere: instruments that measure radiation from the entire sky and instruments that measure only direct solar radiation. Within each of these categories, instruments can be further subdivided into those that measure radiation over a broad range of wavelengths and those that measure only specific wavelengths.

  12. Detecting solar chameleons through radiation pressure

    CERN Document Server

    Baum, S.; Hoffmann, D.H.H.; Karuza, M.; Semertzidis, Y.K.; Upadhye, A.; Zioutas, K.

    2014-10-24

    Light scalar fields can drive the accelerated expansion of the universe. Hence, they are obvious dark energy candidates. To make such models compatible with tests of General Relativity in the solar system and "fifth force" searches on Earth, one needs to screen them. One possibility is the so-called "chameleon" mechanism, which renders an effective mass depending on the local matter density. If chameleon particles exist, they can be produced in the sun and detected on earth exploiting the equivalent of a radiation pressure. Since their effective mass scales with the local matter density, chameleons can be reflected by a dense medium if their effective mass becomes greater than their total energy. Thus, under appropriate conditions, a flux of solar chameleons may be sensed by detecting the total instantaneous momentum transferred to a suitable opto-mechanical force/pressure sensor. We calculate the solar chameleon spectrum and the reach in the chameleon parameter space of an experiment using the preliminary re...

  13. Water purification using solar radiation in Nigeria

    International Nuclear Information System (INIS)

    Udounwa, A.E.; Osuji, R.U.

    2005-12-01

    In developing countries, lack of safe and reliable drinking water constitutes a major problem. Contaminated water is the major cause of most water borne diseases like diarrhoea. Disinfection of water is accomplished by a number of different physical - chemical treatments including boiling, application of chlorine and filtration techniques. Solar energy, which is universally available, can also be used effectively in this process, that is, to deactivate the micro-organisms present in this contaminated water thereby improving its microbiological quality. This treatment process is called solar water disinfection. This paper therefore appraises the extent to which research work has been done as regards purification of water using solar radiation in Nigeria vis-a-vis outside the country. It is hoped that it will serve as a wake-up-call for Nigerians especially those in remote areas with no treated pipe borne water supply. The problems and prospects of this technology as well as the policy implications are presented. (author)

  14. Detecting solar chameleons through radiation pressure

    CERN Document Server

    Baum, Sebastian

    2014-01-01

    Light scalar fields can drive accelerated expansion of the universe. Hence, scalars are obvious dark energy candidates. To make these models compatible with test of General Relativity in the solar system and fifth force searches on earth, one needs to screen them. One possibility is the chameleon mechanism, which renders an effective mass depending on the local energy density. If chameleons exist, they can be produced in the sun and detected on earth through their radiation pressure. We calculate the solar chameleon spectrum and the sensitivity of an experiment to be carried out at CAST, CERN, utilizing a radiation pressure sensor currently under development at INFN, Trieste. We show that such an experiment will be sensitive to a wide range of model parameters and signifies a pioneering effort searching for chameleons in unprobed paramterspace.

  15. Absorption of solar radiation in broken clouds

    Energy Technology Data Exchange (ETDEWEB)

    Zuev, V.E.; Titov, G.A.; Zhuravleva, T.B. [Institute of Atmospheric Optics, Tomsk (Russian Federation)

    1996-04-01

    It is recognized now that the plane-parallel model unsatisfactorily describes the transfer of radiation through broken clouds and that, consequently, the radiation codes of general circulation models (GCMs) must be refined. However, before any refinement in a GCM code is made, it is necessary to investigate the dependence of radiative characteristics on the effects caused by the random geometry of cloud fields. Such studies for mean fluxes of downwelling and upwelling solar radiation in the visible and near-infrared (IR) spectral range were performed by Zuev et al. In this work, we investigate the mean spectral and integrated absorption of solar radiation by broken clouds (in what follows, the term {open_quotes}mean{close_quotes} will be implied but not used, for convenience). To evaluate the potential effect of stochastic geometry, we will compare the absorption by cumulus (0.5 {le} {gamma} {le} 2) to that by equivalent stratus ({gamma} <<1) clouds; here {gamma} = H/D, H is the cloud layer thickness and D the characteristic horizontal cloud size. The equivalent stratus clouds differ from cumulus only in the aspect ratio {gamma}, all the other parameters coinciding.

  16. Electron Radiation Belts of the Solar System

    Science.gov (United States)

    Mauk, Barry; Fox, Nicola

    To address the question of what factors dictate similarities and differences between radiation belts, we present comparisons between the electron radiation belt spectra of all five strongly magnetized planets within the solar system: Earth, Jupiter, Saturn, Uranus, and Neptune. We choose the highest intensity observed electron spectrum within each system (highest specifically near 1 MeV) and compare them against expectations based on the so-called Kennel-Petschek limit (KP; 1966) for each system. For evaluating the KP limit, we begin with the new relativis-tically correct formulation of Summers et al. (2009) but then add several refinements of our own. Specifically, we: 1) utilized a much more flexible analytic spectral shape that allows us to accurately fit observed radiation belt spectra; 2) adopt the point of view that the anisotropy parameter is not a free parameter but must take on a minimal value, as originally proposed by Kennel and Petschek (1966); and 3) examine the differential characteristics of the KP limit along the lines of what Schulz and Davidson (1988) performed for the non-relativistic formula-tion. We find that three factors limit the highest electron radiation belt intensities within solar system planetary magnetospheres: a) whistler mode interactions that limit spectral intensities to a differential Kennel-Petschek limit (3 planets); b) the absence of robust acceleration pro-cesses associated with injection dynamics (1 planet); and c) material interactions between the radiation particles and clouds of gas and dust (1 planet).

  17. Design of direct solar PV driven air conditioner

    KAUST Repository

    Huang, Bin-Juine; Hou, Tung-Fu; Hsu, Po-Chien; Lin, Tse-Han; Chen, Yan-Tze; Chen, Chi-Wen; Li, Kang; Lee, K.Y.

    2015-01-01

    ). The measured OPB is found to be greater than 0.98 at instantaneous solar irradiation IT > 600 W m-2 if rpL > 1.71 RF approaches 1.0 (the air conditioner is run in 100% with solar power) at daily-total solar radiation higher than 13 MJ m-2 day-1, if rpL > 3.

  18. High mortality of Red Sea zooplankton under ambient solar radiation.

    Science.gov (United States)

    Al-Aidaroos, Ali M; El-Sherbiny, Mohsen M O; Satheesh, Sathianeson; Mantha, Gopikrishna; Agustī, Susana; Carreja, Beatriz; Duarte, Carlos M

    2014-01-01

    High solar radiation along with extreme transparency leads to high penetration of solar radiation in the Red Sea, potentially harmful to biota inhabiting the upper water column, including zooplankton. Here we show, based on experimental assessments of solar radiation dose-mortality curves on eight common taxa, the mortality of zooplankton in the oligotrophic waters of the Red Sea to increase steeply with ambient levels of solar radiation in the Red Sea. Responses curves linking solar radiation doses with zooplankton mortality were evaluated by exposing organisms, enclosed in quartz bottles, allowing all the wavelengths of solar radiation to penetrate, to five different levels of ambient solar radiation (100%, 21.6%, 7.2%, 3.2% and 0% of solar radiation). The maximum mortality rates under ambient solar radiation levels averaged (±standard error of the mean, SEM) 18.4±5.8% h(-1), five-fold greater than the average mortality in the dark for the eight taxa tested. The UV-B radiation required for mortality rates to reach ½ of maximum values averaged (±SEM) 12±5.6 h(-1)% of incident UVB radiation, equivalent to the UV-B dose at 19.2±2.7 m depth in open coastal Red Sea waters. These results confirm that Red Sea zooplankton are highly vulnerable to ambient solar radiation, as a consequence of the combination of high incident radiation and high water transparency allowing deep penetration of damaging UV-B radiation. These results provide evidence of the significance of ambient solar radiation levels as a stressor of marine zooplankton communities in tropical, oligotrophic waters. Because the oligotrophic ocean extends across 70% of the ocean surface, solar radiation can be a globally-significant stressor for the ocean ecosystem, by constraining zooplankton use of the upper levels of the water column and, therefore, the efficiency of food transfer up the food web in the oligotrophic ocean.

  19. High mortality of Red Sea zooplankton under ambient solar radiation.

    Directory of Open Access Journals (Sweden)

    Ali M Al-Aidaroos

    Full Text Available High solar radiation along with extreme transparency leads to high penetration of solar radiation in the Red Sea, potentially harmful to biota inhabiting the upper water column, including zooplankton. Here we show, based on experimental assessments of solar radiation dose-mortality curves on eight common taxa, the mortality of zooplankton in the oligotrophic waters of the Red Sea to increase steeply with ambient levels of solar radiation in the Red Sea. Responses curves linking solar radiation doses with zooplankton mortality were evaluated by exposing organisms, enclosed in quartz bottles, allowing all the wavelengths of solar radiation to penetrate, to five different levels of ambient solar radiation (100%, 21.6%, 7.2%, 3.2% and 0% of solar radiation. The maximum mortality rates under ambient solar radiation levels averaged (±standard error of the mean, SEM 18.4±5.8% h(-1, five-fold greater than the average mortality in the dark for the eight taxa tested. The UV-B radiation required for mortality rates to reach ½ of maximum values averaged (±SEM 12±5.6 h(-1% of incident UVB radiation, equivalent to the UV-B dose at 19.2±2.7 m depth in open coastal Red Sea waters. These results confirm that Red Sea zooplankton are highly vulnerable to ambient solar radiation, as a consequence of the combination of high incident radiation and high water transparency allowing deep penetration of damaging UV-B radiation. These results provide evidence of the significance of ambient solar radiation levels as a stressor of marine zooplankton communities in tropical, oligotrophic waters. Because the oligotrophic ocean extends across 70% of the ocean surface, solar radiation can be a globally-significant stressor for the ocean ecosystem, by constraining zooplankton use of the upper levels of the water column and, therefore, the efficiency of food transfer up the food web in the oligotrophic ocean.

  20. Investigation of solar cell radiation damage

    International Nuclear Information System (INIS)

    Bernard, J.; Reulet, R.; Arndt, R.A.

    1974-01-01

    Development of communications satellites has led to the requirement for a greater and longer lived solar cell power source. Accordingly, studies have been undertaken with the aim of determining which solar cell array provides the greatest power at end of life and the amount of degradation. Investigation of the damage done to thin silicon and thin film CdS solar cells is being carried out in two steps. First, irradiations were performed singly with 0.15, 1.0 and 2.0MeV electrons and 0.7, 2.5 and 22MeV proton. Solar cells and their cover materials were irradiated separately in order to locate the sites of the damage. Diffusion length and I.V. characteristics of the cells and transmission properties of the cover materials were measured. All neasurements were made in vacuum immediately after irradiation. In the second part it is intended to study the effect of various combinations of proton, electron and photon irradiation both with and without an electrical load. The results of this part show whether synergism is involved in solar cell damage and the relative importance of each of three radiation sources if synergism is found [fr

  1. Applicability of Daily Solar Radiation Estimated by Mountain Microclimate Simulation Model (MT-CLIM) in Korea

    International Nuclear Information System (INIS)

    Shim, K.M.; Kim, Y.S.; Lee, D.B.; Kang, K.K.; So, K.H.

    2012-01-01

    Accuracy of daily solar radiation estimated from a Mountain Microclimate Simulation Model (MT-CLIM) was assessed for seven observation sites with complex topography in Uiseong County. The coefficient of determination () between the observed and the estimated daily solar radiation was 0.52 for 7 sites for the study period from 1 August to 30 September 2009. Overall, the MT-CLIM overestimated the solar radiation with root mean square error (RMSE) of which is about 25% of the mean daily solar radiation () for the study period. Considering that the pyranometer's tolerance is of standard sensor, the RMSE of MT-CLIM was too large to accept for a direct application for agricultural sector. The reliability of solar radiation estimated by MT-CLIM must be improved by considering additional ways such as using a topography correction coefficient

  2. Solar radiation data sources, applications, and network design

    Energy Technology Data Exchange (ETDEWEB)

    None

    1978-04-01

    A prerequisite to considering solar energy projects is to determine the requirements for information about solar radiation to apply to possible projects. This report offers techniques to help the reader specify requirements in terms of solar radiation data and information currently available, describes the past and present programs to record and present information to be used for most requirements, presents courses of action to help the user meet his needs for information, lists sources of solar radiation data and presents the problems, costs, benefits and responsibilities of programs to acquire additional solar radiation data. Extensive background information is provided about solar radiation data and its use. Specialized information about recording, collecting, processing, storing and disseminating solar radiation data is given. Several Appendices are included which provide reference material for special situations.

  3. Calibration of solar radiation measuring instruments. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Bahm, R J; Nakos, J C

    1979-11-01

    A review of solar radiation measurement of instruments and some types of errors is given; and procedures for calibrating solar radiation measuring instruments are detailed. An appendix contains a description of various agencies who perform calibration of solar instruments and a description of the methods they used at the time this report was prepared. (WHK)

  4. Assessing the Performance of Global Solar Radiation Empirical ...

    African Journals Online (AJOL)

    In the region where solar radiation data are scarce, the next alternative method is to use solar radiation models to estimate the data needed for some applications such as simulation of crop performance and the design of solar energy conversion devices. In this paper, the validations of fifteen models for estimating monthly ...

  5. Future directions in radiation oncology

    International Nuclear Information System (INIS)

    Peters, L.

    1996-01-01

    Full text: Cancer treatment has evolved progressively over the years as a joint result of improvements in technology and better understanding of the biological responses of neoplastic and normal cells to cytotoxic agents. Although major therapeutic 'breakthroughs' are unlikely absent the discovery of exploitable fundamental differences between cancer cells and their normal homologs, further incremental improvements in cancer treatment results can confidently be expected as we apply existing knowledge better and take advantage of new research insights. Areas in which I can foresee significant improvements (in approximate chronological order) are as follows: better physical radiation dose distributions; more effective radiation and chemoradiation protocols based on radiobiological principles; more rational use of radiation adjuvants based on biologic criteria; use of novel targets and vectors for systemic radionuclide therapy; use of genetic markers of radiosensitivity to determine radiation dose tolerances; and use of radiation as a modulator of therapeutic gene expression. Radiation research has contributed greatly to the efficacy of radiation oncology as it is now practised but has even greater potential for the future

  6. Study on Pyroelectric Harvesters Integrating Solar Radiation with Wind Power

    Directory of Open Access Journals (Sweden)

    Chun-Ching Hsiao

    2015-07-01

    Full Text Available Pyroelectric harvesters use temperature fluctuations to generate electrical outputs. Solar radiation and waste heat are rich energy sources that can be harvested. Pyroelectric energy converters offer a novel and direct energy-conversion technology by transforming time-dependent temperatures directly into electricity. Moreover, the great challenge for pyroelectric energy harvesting lies in finding promising temperature variations or an alternating thermal loading in real situations. Hence, in this article, a novel pyroelectric harvester integrating solar radiation with wind power by the pyroelectric effect is proposed. Solar radiation is a thermal source, and wind is a dynamic potential. A disk generator is used for harvesting wind power. A mechanism is considered to convert the rotary energy of the disk generator to drive a shutter for generating temperature variations in pyroelectric cells using a planetary gear system. The optimal period of the pyroelectric cells is 35 s to harvest the stored energy, about 70 μJ, while the rotary velocity of the disk generator is about 31 RPM and the wind speed is about 1 m/s. In this state, the stored energy acquired from the pyroelectric harvester is about 75% more than that from the disk generator. Although the generated energy of the proposed pyroelectric harvester is less than that of the disk generator, the pyroelectric harvester plays a complementary role when the disk generator is inactive in situations of low wind speed.

  7. Solar radiation in the Brazilian northeast

    Energy Technology Data Exchange (ETDEWEB)

    Tiba, Chigueru [Federal University of Pernambuco, Pernambuco (Brazil)

    2000-07-01

    The significant increase in recent years of the number of rural electrification systems (some thousands of them do exist) using photovoltaic technology installed in the Northeast of Brazil (1,500,000 km{sup 2}, approximately 42 million people) used for illumination or water pumping, calls for an improvement on the design procedures in order to reduce the burden of capital costs per unit of generated power. Such objective can be accomplished as long as a better knowledge about the solar resource is achieved, considering how much these applications depend on it. The sources of information on solar radiation in Brazil are quite varied at both institutional and publication level. At institutional Meteorology (INMET), State Departments of Agriculture, research institute, universities and electric power generation and distribution utilities. Progress reports or scientific and technical journals are the main publishing vehicles where this information can be found. This way, data quality varies considerably, showing, spatial and temporal discontinuities, in addition to the fact that measurement instruments and physical units of registered data are not standardized. The Solarimetric Atlas of Brazil was recently published and it contains that information, which is grouped, evaluated, qualified, and presented in a standardized way. It is one of the best currently existing sources of information, and in certainly consists of almost the entirety of the existing information on the solar resource (data on solar radiation and sunshine hours) in Brazil. By using this database, simultaneous records of solar radiation (measured with pyranoghaps or pyranometers) and sunshine hours with heliographs were obtained in 35 different places in the Northeast region. Coefficients a and b were calculated for those different places using Angstrom's correlation. Using the geostatistical interpolation method known as kriging, the values of a and b were placed on contour maps, the coverage of

  8. Estimating the solar radiation environment on the soil surface between rows using crop canopy architectural models

    International Nuclear Information System (INIS)

    Yuge, K.; Haraguchi, T.; Nakano, Y.; Kuroda, M.; Funakoshi, T.

    2002-01-01

    The objective of this study is quantification of the solar radiation in the farmland located in the hilly and mountainous areas, considering the effect of the shelter adjacent to the field, such as the forest (This effect is called as the edge-effect in this study.). To evaluate the edge-effect on the solar radiation environment in the farmland, solar radiations are measured at the center and edge of the study site adjacent to the forest. The simulation model is composed, coupling with the fish-eye projection method and procedure for the separating direct and diffuse solar radiations. Using this model, the diurnal solar radiations are simulated at the center and edge of the study site. The simulation result showed good agreement with the observation. The spatial distribution of the solar radiation in an observational field is quantified by this method, considering the edge-effect. The simulation result indicated that the solar radiation environment on the field surface is affected by the shelter adjacent to the field and the field direction. (author)

  9. Image dissector photocathode solar damage test program. [solar radiation shielding using a fast optical lens

    Science.gov (United States)

    Smith, R. A.

    1977-01-01

    Image dissector sensors of the same type which will be used in the NASA shuttle star tracker were used in a series of tests directed towards obtaining solar radiation/time damage criteria. Data were evaluated to determine the predicted level of operability of the star tracker if tube damage became a reality. During the test series a technique for reducing the solar damage effect was conceived and verified. The damage concepts are outlined and the test methods and data obtained which were used for verification of the technique's feasibility are presented. The ability to operate an image dissector sensor with the solar image focussed on the photocathode by a fast optical lens under certain conditions is feasible and the elimination of a mechanical protection device is possible.

  10. Ultraviolet Radiation in the Solar System

    CERN Document Server

    Vázquez, M

    2006-01-01

    UV radiation is an important part in the electromagnetic spectrum since the energy of the photons is great enough to produce important chemical reactions in the atmospheres of planets and satellites of our Solar System, thereby affecting the transmission of this radiation to the ground and its physical properties. Scientists have used different techniques (balloons and rockets) to access to the information contained in this radiation, but the pioneering of this new frontier has not been free of dangers. The Sun is our main source of UV radiation and its description occupies the first two chapters of the book. The Earth is the only known location where life exists in a planetary system and therefore where the interaction of living organism with UV radiation can be tested through different epochs and on distinct species. The development of the human technology has affected the natural shield of ozone that protects complex lifeforms against damaging UV irradiation. The formation of the ozone hole and its consequ...

  11. Estimation of Solar Radiation using Artificial Neural Network

    Directory of Open Access Journals (Sweden)

    Slamet Suprayogi

    2004-01-01

    Full Text Available The solar radiation is the most important fator affeccting evapotranspiration, the mechanism of transporting the vapor from the water surface has also a great effect. The main objectives of this study were to investigate the potential of using Artificial Neural Network (ANN to predict solar radiation related to temperature. The three-layer backpropagation were developed, trained, and tested to forecast solar radiation for Ciriung sub Cachment. Result revealed that the ANN were able to well learn the events they were trained to recognize. Moreover, they were capable of effecctively generalize their training by predicting solar radiation for sets unseen cases.

  12. Characterization of Tin/Ethylene Glycol Solar Nanofluids Synthesized by Femtosecond Laser Radiation.

    Science.gov (United States)

    Torres-Mendieta, Rafael; Mondragón, Rosa; Puerto-Belda, Verónica; Mendoza-Yero, Omel; Lancis, Jesús; Juliá, J Enrique; Mínguez-Vega, Gladys

    2017-05-05

    Solar energy is available over wide geographical areas and its harnessing is becoming an essential tool to satisfy the ever-increasing demand for energy with minimal environmental impact. Solar nanofluids are a novel solar receiver concept for efficient harvesting of solar radiation based on volumetric absorption of directly irradiated nanoparticles in a heat transfer fluid. Herein, the fabrication of a solar nanofluid by pulsed laser ablation in liquids was explored. This study was conducted with the ablation of bulk tin immersed in ethylene glycol with a femtosecond laser. Laser irradiation promotes the formation of tin nanoparticles that are collected in the ethylene glycol as colloids, creating the solar nanofluid. The ability to trap incoming electromagnetic radiation, thermal conductivity, and the stability of the solar nanofluid in comparison with conventional synthesis methods is enhanced. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Analysis of solar radiation transfer: A method to estimate the porosity of a plastic shading net

    International Nuclear Information System (INIS)

    Abdel-Ghany, A.M.; Al-Helal, I.M.

    2011-01-01

    Plastic nets with opaque threads are frequently used for shading agricultural structures under high solar radiation conditions. A parameter that is often used to define a net is the net porosity (Π). Value of Π is usually estimated by one of three methods: image processing, direct beam transmittance, or solar radiation balance (hereafter radiation balance). Image processing is a rather slow process because it requires scanning the net sample at high resolution. The direct beam transmittance and radiation balance methods greatly overestimate Π because some of the solar radiation incident on the thread surfaces is forward scattered and add a considerable amount of radiation to that transmitted from the net pores directly. In this study, the radiation balance method was modified to estimate Π precisely. The amount of solar radiation scattered forward on the thread surfaces was estimated separately. Thus, the un-scattered solar radiation transmitted from the net pores directly, which describes the net porosity, Π could be estimated. This method, in addition to the image processing and the direct beam transmittance methods were used to estimate Π for different types of nets that are commonly used for shading structures in summer. Values of Π estimated by using the proposed method were in good accordance with those measured by the image processing method at a resolution of 4800 dpi. The direct beam transmittance and the radiation balance methods resulted in overestimation errors in the values of Π. This error strongly depends on the color of the net. The estimated errors were +14% for a green net and +37% for a white net when using the radiation balance method, and were +16% and +38%, respectively, when using the direct beam transmittance method. In the image processing method, a resolution of 2400 dpi is sufficient to estimate Π precisely and the higher resolutions showed no significant effect on the value of Π.

  14. Radiation effects in silicon and gallium arsenide solar cells using isotropic and normally incident radiation

    Science.gov (United States)

    Anspaugh, B. E.; Downing, R. G.

    1984-01-01

    Several types of silicon and gallium arsenide solar cells were irradiated with protons with energies between 50 keV and 10 MeV at both normal and isotropic incidence. Damage coefficients for maximum power relative to 10 MeV were derived for these cells for both cases of omni-directional and normal incidence. The damage coefficients for the silicon cells were found to be somewhat lower than those quoted in the Solar Cell Radiation Handbook. These values were used to compute omni-directional damage coefficients suitable for solar cells protected by coverglasses of practical thickness, which in turn were used to compute solar cell degradation in two proton-dominated orbits. In spite of the difference in the low energy proton damage coefficients, the difference between the handbook prediction and the prediction using the newly derived values was negligible. Damage coefficients for GaAs solar cells for short circuit current, open circuit voltage, and maximum power were also computed relative to 10 MeV protons. They were used to predict cell degradation in the same two orbits and in a 5600 nmi orbit. Results show the performance of the GaAs solar cells in these orbits to be superior to that of the Si cells.

  15. Seasonal and interannual variability of solar radiation at Spirit, Opportunity and Curiosity landing sites

    International Nuclear Information System (INIS)

    Vicente-Retortillo, A.; Lemmon, M.T.; Martinez, G.; Valero, F.; Vazquez, L.; Martin, M.L.

    2016-01-01

    In this article we characterize the radiative environment at the landing sites of NASA's Mars Exploration Rover (MER) and Mars Science Laboratory (MSL) missions. We use opacity values obtained at the surface from direct imaging of the Sun and our radiative transfer model COMIMART to analyze the seasonal and interannual variability of the daily irradiation at the MER and MSL landing sites. In addition, we analyze the behavior of the direct and diffuse components of the solar radiation at these landing sites. (Author)

  16. Solar energy R + D programme, 1979-1983. Project F: solar radiation data

    Energy Technology Data Exchange (ETDEWEB)

    1981-01-01

    Individual presentations report work in the following areas: production of test reference years for model simulation of solar systems and components; global radiation atlas for horizontal surfaces; radiation data on inclined surfaces; intensity thresholds and cumulative frequency curves; useful energy output from solar collectors; network comparison of pyranometers; measurements of turbidity, spectral radiation, etc.; satellite data. (LEW)

  17. Shield or not to Shield: Effects of Solar Radiation on Water Temperature Sensor Accuracy

    Directory of Open Access Journals (Sweden)

    Robert L. Wilby

    2013-10-01

    Full Text Available Temperature sensors are potentially susceptible to errors due to heating by solar radiation. Although this is well known for air temperature (Ta, significance to continuous water temperature (Tw monitoring is relatively untested. This paper assesses radiative errors by comparing measurements of exposed and shielded Tinytag sensors under indirect and direct solar radiation, and in laboratory experiments under controlled, artificial light. In shallow, still-water and under direct solar radiation, measurement discrepancies between exposed and shielded sensors averaged 0.4 °C but can reach 1.6 °C. Around 0.3 °C of this inconsistency is explained by variance in measurement accuracy between sensors; the remainder is attributed to solar radiation. Discrepancies were found to increase with light intensity, but to attain Tw differences in excess of 0.5 °C requires direct, bright solar radiation (>400 W m−2 in the total spectrum. Under laboratory conditions, radiative errors are an order of magnitude lower when thermistors are placed in flowing water (even at velocities as low as 0.1 m s−1. Radiative errors were also modest relative to the discrepancy between different thermistor manufacturers. Based on these controlled experiments, a set of guidelines are recommended for deploying thermistor arrays in water bodies.

  18. Simulation of solar radiative transfer in cumulus clouds

    Energy Technology Data Exchange (ETDEWEB)

    Zuev, V.E.; Titov, G.A. [Institute of Atmospheric Optics, Tomsk (Russian Federation)

    1996-04-01

    This work presents a 3-D model of radiative transfer which is used to study the relationship between the spatial distribution of cumulus clouds and fluxes (albedo and transmittance) of visible solar radiation.

  19. Climate variation based on temperature and solar radiation data ...

    African Journals Online (AJOL)

    ckaonga

    2015-03-12

    Mar 12, 2015 ... addition, the concentration of carbon dioxide over Malawi within the same period as temperature and solar radiation data ... plant diseases and pests which may have adverse effects ... object that absorbs and emits radiation).

  20. Measurement of solar energy radiation in Abu Dhabi, UAE

    International Nuclear Information System (INIS)

    Islam, M.D.; Kubo, I.; Ohadi, M.; Alili, A.A.

    2009-01-01

    This paper presents data on measurement of actual solar radiation in Abu Dhabi (24.43 deg. N, 54.45 deg. E). Global solar radiation and surface temperatures were measured and analyzed for one complete year. High resolution, real-time solar radiation and other meteorological data were collected and processed. Daily and monthly average solar radiation values were calculated from the one-minute average recorded values. The highest daily and monthly mean solar radiation values were 369 and 290 W/m 2 , respectively. The highest one-minute average daily solar radiation was 1041 W/m 2 . Yearly average daily energy input was 18.48 MJ/m 2 /day. Besides the global solar radiation, the daily and monthly average clearness indexes along with temperature variations are discussed. When possible, global solar energy radiation and some meteorological data are compared with corresponding data in other Arab state capitals. The data collected indicate that Abu Dhabi has a strong potential for solar energy capture

  1. Measurement of solar energy radiation in Abu Dhabi, UAE

    Energy Technology Data Exchange (ETDEWEB)

    Islam, M.D.; Kubo, I.; Ohadi, M.; Alili, A.A. [Department of Mechanical Engineering, The Petroleum Institute, Abu Dhabi, P.O. Box 2533 (United Arab Emirates)

    2009-04-15

    This paper presents data on measurement of actual solar radiation in Abu Dhabi (24.43 N, 54.45 E). Global solar radiation and surface temperatures were measured and analyzed for one complete year. High resolution, real-time solar radiation and other meteorological data were collected and processed. Daily and monthly average solar radiation values were calculated from the one-minute average recorded values. The highest daily and monthly mean solar radiation values were 369 and 290 W/m{sup 2}, respectively. The highest one-minute average daily solar radiation was 1041 W/m{sup 2}. Yearly average daily energy input was 18.48 MJ/m{sup 2}/day. Besides the global solar radiation, the daily and monthly average clearness indexes along with temperature variations are discussed. When possible, global solar energy radiation and some meteorological data are compared with corresponding data in other Arab state capitals. The data collected indicate that Abu Dhabi has a strong potential for solar energy capture. (author)

  2. NRC TLD Direct Radiation Monitoring Network

    International Nuclear Information System (INIS)

    Struckmeyer, R.

    1994-03-01

    This report presents the results of the NRC Direct Radiation Monitoring Network for the fourth quarter of 1993. It provides the ambient radiation levels measured in the vicinity of 75 sites throughout the United States. In addition, it describes the equipment used, monitoring station selection criteria, characterization of the dosimeter response, calibration procedures, statistical methods, intercomparison, and quality assurance program

  3. NRC TLD Direct Radiation Monitoring Network

    International Nuclear Information System (INIS)

    Struckmeyer, R.; McNamara, N.

    1993-03-01

    This report present the results of the NRC Direct Radiation Monitoring Network for the fourth quarter of 1992. It provides the ambient radiation levels measured in the vicinity of 75 sites throughout the United States. In addition, it describes the equipment used, monitoring station selection criteria, characterization of the dosimeter response, calibration procedures, statistical methods, intercomparison, and quality assurance program

  4. Detecting solar chameleons through radiation pressure

    International Nuclear Information System (INIS)

    Baum, S.; Cantatore, G.; Hoffmann, D.H.H.; Karuza, M.; Semertzidis, Y.K.; Upadhye, A.; Zioutas, K.

    2014-01-01

    Light scalar fields can drive the accelerated expansion of the universe. Hence, they are obvious dark energy candidates. To make such models compatible with tests of General Relativity in the solar system and “fifth force” searches on Earth, one needs to screen them. One possibility is the so-called “chameleon” mechanism, which renders an effective mass depending on the local matter density. If chameleon particles exist, they can be produced in the sun and detected on Earth exploiting the equivalent of a radiation pressure. Since their effective mass scales with the local matter density, chameleons can be reflected by a dense medium if their effective mass becomes greater than their total energy. Thus, under appropriate conditions, a flux of solar chameleons may be sensed by detecting the total instantaneous momentum transferred to a suitable opto-mechanical force/pressure sensor. We calculate the solar chameleon spectrum and the reach in the chameleon parameter space of an experiment using the preliminary results from a force/pressure sensor, currently under development at INFN Trieste, to be mounted in the focal plane of one of the X-Ray telescopes of the CAST experiment at CERN. We show, that such an experiment signifies a pioneering effort probing uncharted chameleon parameter space

  5. Detecting solar chameleons through radiation pressure

    Energy Technology Data Exchange (ETDEWEB)

    Baum, S., E-mail: sebastian.baum@cern.ch [Uppsala Universitet, Box 516, SE 75120, Uppsala (Sweden); European Organization for Nuclear Research (CERN), Gèneve (Switzerland); Cantatore, G. [Università di Trieste, Via Valerio 2, 34127 Trieste (Italy); INFN Trieste, Padriciano 99, 34149 Trieste (Italy); Hoffmann, D.H.H. [Institut für Kernphysik, TU-Darmstadt, Schlossgartenstr. 9, D-64289 Darmstadt (Germany); Karuza, M. [INFN Trieste, Padriciano 99, 34149 Trieste (Italy); Phys. Dept. and CMNST, University of Rijeka, R. Matejcic 2, Rijeka (Croatia); Semertzidis, Y.K. [Center for Axion and Precision Physics Research (IBS), Daejeon 305-701 (Korea, Republic of); Department of Physics, KAIST, Daejeon 305-701 (Korea, Republic of); Upadhye, A. [Physics Department, University of Wisconsin–Madison, 1150 University Avenue, Madison, WI 53706 (United States); Zioutas, K., E-mail: konstantin.zioutas@cern.ch [European Organization for Nuclear Research (CERN), Gèneve (Switzerland); University of Patras, GR 26504 Patras (Greece)

    2014-12-12

    Light scalar fields can drive the accelerated expansion of the universe. Hence, they are obvious dark energy candidates. To make such models compatible with tests of General Relativity in the solar system and “fifth force” searches on Earth, one needs to screen them. One possibility is the so-called “chameleon” mechanism, which renders an effective mass depending on the local matter density. If chameleon particles exist, they can be produced in the sun and detected on Earth exploiting the equivalent of a radiation pressure. Since their effective mass scales with the local matter density, chameleons can be reflected by a dense medium if their effective mass becomes greater than their total energy. Thus, under appropriate conditions, a flux of solar chameleons may be sensed by detecting the total instantaneous momentum transferred to a suitable opto-mechanical force/pressure sensor. We calculate the solar chameleon spectrum and the reach in the chameleon parameter space of an experiment using the preliminary results from a force/pressure sensor, currently under development at INFN Trieste, to be mounted in the focal plane of one of the X-Ray telescopes of the CAST experiment at CERN. We show, that such an experiment signifies a pioneering effort probing uncharted chameleon parameter space.

  6. Biological Sensors for Solar Ultraviolet Radiation

    Directory of Open Access Journals (Sweden)

    André P. Schuch

    2011-04-01

    Full Text Available Solar ultraviolet (UV radiation is widely known as a genotoxic environmental agent that affects Earth ecosystems and the human population. As a primary consequence of the stratospheric ozone layer depletion observed over the last decades, the increasing UV incidence levels have heightened the concern regarding deleterious consequences affecting both the biosphere and humans, thereby leading to an increase in scientific efforts to understand the role of sunlight in the induction of DNA damage, mutagenesis, and cell death. In fact, the various UV-wavelengths evoke characteristic biological impacts that greatly depend on light absorption of biomolecules, especially DNA, in living organisms, thereby justifying the increasing importance of developing biological sensors for monitoring the harmful impact of solar UV radiation under various environmental conditions. In this review, several types of biosensors proposed for laboratory and field application, that measure the biological effects of the UV component of sunlight, are described. Basically, the applicability of sensors based on DNA, bacteria or even mammalian cells are presented and compared. Data are also presented showing that on using DNA-based sensors, the various types of damage produced differ when this molecule is exposed in either an aqueous buffer or a dry solution. Apart from the data thus generated, the development of novel biosensors could help in evaluating the biological effects of sunlight on the environment. They also emerge as alternative tools for using live animals in the search for protective sunscreen products.

  7. Optimization of Stirling and Ericsson cycles by solar radiation

    Science.gov (United States)

    Badescu, V.

    This paper considers a model consisting of a source of radiation (the sun) and two energy converters. The first converter (the absorber) transforms the solar radiation into heat while the second one (which is a Stirling or Ericsson engine) uses heat to produce mechanical work. Polarization coefficients were introduced to characterize the radiation emitted by two components of the system (the sun and the first converter). The maximum conversion efficiency of solar radiation into work was studied.

  8. Simulation of Solar Radiation Incident on Horizontal and Inclined Surfaces

    Directory of Open Access Journals (Sweden)

    MA Basunia

    2012-12-01

    Full Text Available A computer model was developed to simulate the hourly, daily and monthly average of daily solar radiation on horizontal and inclined surfaces. The measured hourly and daily solar radiation was compared with simulated radiation, and favourable agreement was observed for the measured and predicted values on clear days. The measured and simulated monthly averages of total (diffuse and beam daily solar radiation were compared and a reasonable agreement was observed for a number of stations in Japan. The simulation showed that during the rice harvesting season, September to October, there is a daily average of 14.7 MJ/m2 of solar irradiation on a horizontal surface in Matsuyama, Japan. There is a similar amount of solar radiation on a horizontal surface during the major rice harvesting season, November to December, in Bangladesh. This radiation can be effectively utilized for drying rough rice and other farm crops.

  9. A rapid radiative transfer model for reflection of solar radiation

    Science.gov (United States)

    Xiang, X.; Smith, E. A.; Justus, C. G.

    1994-01-01

    A rapid analytical radiative transfer model for reflection of solar radiation in plane-parallel atmospheres is developed based on the Sobolev approach and the delta function transformation technique. A distinct advantage of this model over alternative two-stream solutions is that in addition to yielding the irradiance components, which turn out to be mathematically equivalent to the delta-Eddington approximation, the radiance field can also be expanded in a mathematically consistent fashion. Tests with the model against a more precise multistream discrete ordinate model over a wide range of input parameters demonstrate that the new approximate method typically produces average radiance differences of less than 5%, with worst average differences of approximately 10%-15%. By the same token, the computational speed of the new model is some tens to thousands times faster than that of the more precise model when its stream resolution is set to generate precise calculations.

  10. Solar radiation in the Baltic Sea

    Directory of Open Access Journals (Sweden)

    Jerzy Dera

    2010-12-01

    Full Text Available The influx of solar radiation to the Baltic Sea and its penetration into its waters is described on the basis of selected results of optical and bio-optical studies in the Baltic published by various authors during the past ca 50 years. The variability in the natural irradiance of this sea is illustrated on time scales from short-term fluctuations occurring during a single day to differences in mean monthly values over a period of many years. Data on variability of the proportions between UV, VIS and IR energy in the light reaching the sea surface are also discussed.Long-term monthly mean values of the incident solar radiation flux at the surface of the Baltic Proper are given; they were obtained from meteorological and solar radiation measurements and model approximations. The transmittances of these mean monthly radiation fluxes across the surface of the Baltic are given, as are the typical energyand spectral characteristics of the underwater irradiance, its attenuation with depth in the sea and the associated euphotic zone depths, as well as typical ranges of variability of these characteristics in different Baltic basins. Some of these characteristics are illustrated by typical empirical data. These mean values are not fully representative, however, because with the sole use of classical in situ measurement methods from on board research vessels in the Baltic, it has not been possible to gather a sufficientlyrepresentative set of empirical data that would adequately reflect the variability of the optical characteristics of all the basins of this sea. The article goes on to introduce the statistical model of vertical distributions of chlorophyll a concentration in the Baltic and the bio-optical model of Baltic Case 2 waters, the use of which contribute very significantly to this description of the optical characteristics and will enable this data set to be hugely expanded to include all the Baltic basins. This opportunity is presented by the

  11. Analysis of radiation damage in on-orbit solar array of Venus explorer Akatsuki

    International Nuclear Information System (INIS)

    Toyota, Hiroyuki; Shimada, Takanobu; Takahashi, You; Imamura, Takeshi; Hada, Yuko; Ishii, Takako T.; Isobe, Hiroaki; Asai, Ayumi; Shiota, Daikou

    2013-01-01

    This paper describes an analysis of radiation damage in solar array of Venus explorer Akatsuki observed on orbit. The output voltage of the solar array have shown sudden drops, which are most reasonably associated with radiation damage, three times since its launch. The analysis of these radiation damages is difficult, because no direct observation data of the spectra and the amount of the high-energy particles is available. We calculated the radiation damage using the relative damage coefficient (RDC) method assuming a typical spectral shape of protons. (author)

  12. Climatic zones of solar radiation of Galicia; Zonas climaticas de radiacion solar de Galicia

    Energy Technology Data Exchange (ETDEWEB)

    Vazquez, M.; Izquierdo, P.; Pose, M.; Prado, M. T.; Santos, J.

    2008-07-01

    The paper shows the results of a research on the solar radiation received in Galicia that allows assigning each one of the 315 Galician municipalities to one of the Climatic Zones of solar radiation, defined in the Spanish Building Technical Code (BTC). It is proposed to complete the assignment of climatic Zones in the BTC with a new zone, named Climatic Zone 0, with the objective to differentiate the geographical areas in Galicia with less than 3.4 kWh/m{sup 2}.day of yearly daily average solar radiation. The study is completed with the realization of a map of the Climate Zones of solar radiation of Galicia. (Author)

  13. Precise estimation of total solar radiation on tilted surface

    African Journals Online (AJOL)

    rajeev

    rarely available required for precise sizing of energy systems. The total solar radiation at different orientation and slope is needed to calculate the efficiency of the installed solar energy systems. To calculate clearness index (Kt) used by Gueymard (2000) for estimating solar irradiation H, irradiation at the earth's surface has ...

  14. Directions in Radiation Transport Modelling

    Directory of Open Access Journals (Sweden)

    P Nicholas Smith

    2016-12-01

    More exciting advances are on the horizon to increase the power of simulation tools. The advent of high performance computers is allowing bigger, higher fidelity models to be created, if the challenges of parallelization and memory management can be met. 3D whole core transport modelling is becoming possible. Uncertainty quantification is improving with large benefits to be gained from more accurate, less pessimistic estimates of uncertainty. Advanced graphical displays allow the user to assimilate and make sense of the vast amounts of data produced by modern modelling tools. Numerical solvers are being developed that use goal-based adaptivity to adjust the nodalisation of the system to provide the optimum scheme to achieve the user requested accuracy on the results, thus removing the need to perform costly convergence studies in space and angle etc. More use is being made of multi-physics methods in which radiation transport is coupled with other phenomena, such as thermal-hydraulics, structural response, fuel performance and/or chemistry in order to better understand their interplay in reactor cores.

  15. Resonance in the restricted problem caused by solar radiation pressure

    International Nuclear Information System (INIS)

    Bhatnagar, K.B.; Gupta, B.

    1977-01-01

    Resonance is discussed in the motion of an artificial Earth satellite caused by solar radiation pressure. The Hamiltonian and the generating functions occurring in the problem are expanded in the power series of small parameter β, which depends on solar radiation pressure. Also the perturbations in the osculating elements are obtained up to O(βsup(1/2)). (author)

  16. Direction selective structural-acoustic coupled radiator

    Science.gov (United States)

    Seo, Hee-Seon; Kim, Yang-Hann

    2005-04-01

    This paper presents a method of designing a structural-acoustic coupled radiator that can emit sound in the desired direction. The structural-acoustic coupled system is consisted of acoustic spaces and wall. The wall composes two plates and an opening, and the wall separates one space that is highly reverberant and the other that is unbounded without any reflection. An equation is developed that predicts energy distribution and energy flow in the two spaces separated by the wall, and its computational examples are presented including near field acoustic characteristics. To design the directional coupled radiator, Pareto optimization method is adapted. An objective is selected to maximize radiation power on a main axis and minimize a side lobe level and a subjective is selected direction of the main axis and dimensions of the walls geometry. Pressure and intensity distribution of the designed radiator is also presented.

  17. IMPACT OF SOLAR RADIATION CHANGE ON THE COLLECTOR EFFICIENTLY

    Directory of Open Access Journals (Sweden)

    Danuta Proszak-Miąsik

    2017-01-01

    Full Text Available In October 2014 in a building of Rzeszow University of Technology, a series of measurements was taken to calculate the parameters of a solar system with a flat collector, as installed on the roof of the building. The following parameters were obtained: the value of solar radiation intensity, the temperature of external air, the temperature on the collector, the temperature of water in the tank and the temperature of glycol on the supply and return lines. On the basis of the data received, charts were made to visually present how changes of solar radiation intensity affected parameters of the system. The study was conducted in autumn when the intensity of solar radiation decreases, compared with summer months. The publication aims to show that the solar system brings energy gains in periods of transition, and the instantaneous intensity of solar radiation are comparable to those in the summer.

  18. First principle analyses of direct bandgap solar cells with absorbing substrates versus mirrors

    Energy Technology Data Exchange (ETDEWEB)

    Kirk, Alexander P. [School of Electrical, Computer and Energy Engineering, Arizona State University, Tempe, Arizona 85287 (United States); Kirk, Wiley P. [Department of Materials Science and Engineering, University of Texas at Arlington, Arlington, Texas 76019 (United States)

    2013-11-07

    Direct bandgap InP, GaAs, CdTe, and Ga{sub 0.5}In{sub 0.5}P solar cells containing backside mirrors as well as parasitically absorbing substrates are analyzed for their limiting open circuit voltage and power conversion efficiency with comparison to record solar cells. From the principle of detailed balance, it is shown quantitatively that mirror solar cells have greater voltage and power conversion efficiency than their substrate counterparts. Next, the radiative recombination coefficient and maximum radiative lifetime of GaAs mirror and substrate solar cells are calculated and compared to the nonradiative Auger and Shockley-Read-Hall (SRH) lifetimes. Mirror solar cells have greater radiative lifetime than their substrate variants. Auger lifetime exceeds radiative lifetime for both substrate and mirror cells while SRH lifetime may be less or greater than radiative lifetime depending on trap concentration and capture cross section. Finally, the change in free energy of the photogenerated carriers is analyzed in a comparison between InP, GaAs, CdTe, and Ga{sub 0.5}In{sub 0.5}P mirror and substrate solar cells in order to characterize the relationship between solar photon quality and free energy management in solar cells with differing bandgaps. Wider bandgap visible threshold Ga{sub 0.5}In{sub 0.5}P solar cells make better use of the available change in free energy of the photogenerated charge carriers, even when normalized to the bandgap energy, than narrower bandgap near-IR threshold InP, GaAs, and CdTe solar cells.

  19. Annual cycle of solar radiation in a deciduous forest

    International Nuclear Information System (INIS)

    Hutchison, B.A.; Matt, D.R.

    1977-01-01

    Periodic solar radiation measurements within and above an east Tennessee Liriodendron forest and continuous records of insolation from a nearby NOAA weather station were used to derive an approximation of the animal radiation regime within and above the deciduous forest. The interaction of changing solar elevations, insolation, and forest phenology are shown to control the radiation climate within the forest. Maximum radiation penetrates the forest in early spring as solar paths rise higher in the sky each day just prior to leaf expansion. After leaf expansion begins, average radiation received within the forest decreases rapidly despite continued increases in solar elevations and daily insolation. This forest attains full leaf in early June and from then until the advent of leaf abscission near the autumnal equinox, forest structure remains relatively static. Solar elevations and daily insolation decline following the summer solstice, however, and as a result, average radiation penetrating the forest slowly declines throughout the summer reaching an annual minimum in early autumn. With leaf fall, slightly increased amounts of radiation penetrate the forest but as within-forest solar paths continue to lengthen, radiation within the forest again declines. Minimum amounts of solar radiation penetrate the leafless forest around the winter solstice

  20. The National Solar Radiation Database (NSRDB): A Brief Overview

    Energy Technology Data Exchange (ETDEWEB)

    Habte, Aron M [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Sengupta, Manajit [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Lopez, Anthony [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

    2017-09-25

    This poster presents a high-level overview of the National Solar Radiation Database (NSRDB). The NSRDB uses the physics-based model (PSM), which was developed using: adapted PATMOS-X model for cloud identification and properties, REST-2 model for clear-sky conditions, and NREL's Fast All-sky Radiation Model for Solar Applications (FARMS) for cloudy-sky Global Horizontal Irradiance (GHI) solar irradiance calculations.

  1. Development of Software for Measurement and Analysis of Solar Radiation

    International Nuclear Information System (INIS)

    Mohamad Idris Taib; Abul Adli Anuar; Noor Ezati Shuib

    2015-01-01

    This software was under development using LabVIEW to be using with StellarNet spectrometers system with USB communication to computer. LabVIEW have capabilities in hardware interfacing, graphical user interfacing and mathematical calculation including array manipulation and processing. This software read data from StellarNet spectrometer in real-time and then processed for analysis. Several measurement of solar radiation and analysis have been done. Solar radiation involved mainly infra-red, visible light and ultra-violet. With solar radiation spectrum data, information of weather and suitability of plant can be gathered and analyzed. Furthermore, optimization of utilization and safety precaution of solar radiation can be planned. Using this software, more research and development in utilization and safety of solar radiation can be explored. (author)

  2. Determination of radiation direction in environmental monitoring

    International Nuclear Information System (INIS)

    Campos, Vicente de Paulo de; Moura, Eduardo S.; Rocha, Felicia D.G.; Manzoli, Jose Eduardo

    2009-01-01

    The assessment of environmental exposure has been performed in Brazil using the thermoluminescence technique at Thermoluminescence Dosimetry Laboratory (LDT), at Nuclear and Energetic Research Institute (IPEN/CNEN-SP). To carry out these measurements, several thermoluminescent dosimeters (TLD's) were used to measure the expose. In this procedure, very few information of direction where the radiation came from is available. A vague supposition about the direction from where the radiation came from could be inferred only by evaluation of multiple dosimeters displaced at entire region of monitoring, but this demand to much effort or sometimes become impractical for certain situations. In this work, a single device is used to provide information about the direction from where the radiation came through. This device is called directional dosimeter (DD). Using more than one DD it is possible to reduce the uncertainty of the measurements and determine the radiation source position. The DD basically consists of a regular solid with high effective atomic number, where one TLD is positioned at each face. The DD allows evaluating the environmental exposure and the direction of the radiation by a simple vector sum. At each face of the DD, it is associated an orthogonal vector, and modulus of this vector represents the correspond exposure measured by the TLD. The direction of the radiation source is the sum of these faces vectors. The prototype used in this work was a lead cube with six TLDs of CaSO 4 :Dy/Teflon. The TLDs have high sensibility and are already used in area, environmental and personal monitoring. The measurements had shown the correct environmental exposure and a good indication of the radiation direction. (author)

  3. Preliminary Results on Design and Implementation of a Solar Radiation Monitoring System

    Directory of Open Access Journals (Sweden)

    Lorentz Jäntschi

    2008-02-01

    Full Text Available The paper presents a solar radiation monitoring system, using two scientificpyranometers and an on-line computer home-made data acquisition system. The firstpyranometer measures the global solar radiation and the other one, which is shaded,measure the diffuse radiation. The values of total and diffuse solar radiation arecontinuously stored into a database on a server. Original software was created for dataacquisition and interrogation of the created system. The server application acquires the datafrom pyranometers and stores it into a database with a baud rate of one record at 50seconds. The client-server application queries the database and provides descriptivestatistics. A web interface allow to any user to define the including criteria and to obtainthe results. In terms of results, the system is able to provide direct, diffuse and totalradiation intensities as time series. Our client-server application computes also derivateheats. The ability of the system to evaluate the local solar energy potential is highlighted.

  4. Sweat Rate Prediction Equations for Outdoor Exercise with Transient Solar Radiation

    Science.gov (United States)

    2012-01-01

    AD] 15 Interchangeable variables gSL W/m2 Global solar load Direct weather station data; pyranometer values 25 Direct measurement from weather station... pyranometer (to measure short-wave radiation fluxes) and pyrgeometer (to measure long-wave radiation fluxes). Normally, the value of the solar load...as described below. During field operations, Rsol (W/m2) can be calculated from 0.835 ·ERF. If Rsol (in W/m2) is known by direct pyranometer mea

  5. The solar ultraviolet B radiation protection provided by shading devices with regard to its diffuse component.

    Science.gov (United States)

    Kudish, Avraham I; Harari, Marco; Evseev, Efim G

    2011-10-01

    The composition of the incident solar global ultraviolet B (UVB) radiation with regard to its beam and diffuse radiation fractions is highly relevant with regard to outdoor sun protection. This is especially true with respect to sun protection during leisure-time outdoor sun exposure at the shore and pools, where people tend to escape the sun under shade trees or different types of shading devices, e.g., umbrellas, overhangs, etc., believing they offer protection from the erythemal solar radiation. The degree of sun protection offered by such devices is directly related to the composition of the solar global UVB radiation, i.e., its beam and diffuse fractions. The composition of the incident solar global UVB radiation can be determined by measuring the global UVB (using Solar Light Co. Inc., Model 501A UV-Biometer) and either of its components. The beam component of the UVB radiation was determined by measuring the normal incidence beam radiation using a prototype, tracking instrument consisting of a Solar Light Co. Inc. Model 501A UV-Biometer mounted on an Eppley Solar Tracker Model St-1. The horizontal beam component of the global UVB radiation was calculated from the measured normal incidence using a simple geometric correlation and the diffuse component is determined as the difference between global and horizontal beam radiations. Horizontal and vertical surfaces positioned under a horizontal overhang/sunshade or an umbrella are not fully protected from exposure to solar global UVB radiation. They can receive a significant fraction of the UVB radiation, depending on their location beneath the shading device, the umbrella radius and the albedo (reflectance) of the surrounding ground surface in the case of a vertical surface. Shading devices such as an umbrella or horizontal overhang/shade provide relief from the solar global radiation and do block the solar global UVB radiation to some extent; nevertheless, a significant fraction of the solar global UVB

  6. Effects of solar UV-B radiation on aquatic ecosystems

    Science.gov (United States)

    Häder, D.-P.

    Solar UV degrades dissolved organic carbon photolytically so that they can readily be taken up by bacterioplankton. On the other hand solar UV radiation inhibits bacterioplankton activity. Bacterioplankton productivity is far greater than previously thought and is comparable to phytoplankton primary productivity. According to the "microbial loop hypothesis," bacterioplankton is seen in the center of a food web, having a similar function to phytoplankton and protists. The penetration of UV and PAR into the water column can be measured. Marine waters show large temporal and regional differences in their concentrations of dissolved and particulate absorbing substances. A network of dosimeters (ELDONET) has been installed in Europe ranging from Abisko in Northern Sweden to Gran Canaria. Cyanobacteria are capable of fixing atmospheric nitrogen which is then made available to higher plants. The agricultural potential of cyanobacteria has been recognized as a biological fertilizer for wet soils such as in rice paddies. UV-B is known to impair processes such as growth, survival, pigmentation, motility, as well as the enzymes of nitrogen metabolism and CO 2 fixation. The marine phytoplankton represents the single most important ecosystem on our planet and produces about the same biomass as all terrestrial ecosystems taken together. It is the base of the aquatic food chain and any changes in the size and composition of phytoplankton communities will directly affect food production for humans from marine sources. Another important role of marine phytoplankton is to serve as a sink for atmospheric carbon dioxide. Recent investigations have shown a large sensitivity of most phytoplankton organisms toward solar short-wavelength ultraviolet radiation (UV-B); even at ambient levels of UV-B radiation many organisms seem to be under UV stress. Because of their requirement for solar energy, the phytoplankton dwell in the top layers of the water column. In this near-surface position

  7. NRC TLD Direct Radiation Monitoring Network

    International Nuclear Information System (INIS)

    Struckmeyer, R.; McNamara, N.

    1992-06-01

    The US Nuclear Regulatory Commission (NRC) Direct Radiation Monitoring Network is operated by the NRC in cooperation with participating states to provide continuous measurement of the ambient radiation levels around licensed NRC facilities, primarily power reactors. Ambient radiation levels result from naturally occurring radionuclides present in the soil, cosmic radiation constantly bombarding the earth from outer space, and the contribution, if any, from the monitored facilities and other man-made sources. The Network is intended to measure radiation levels during routine facility operations and to establish background radiation levels used to assess the radiological impact of an unusual condition, such as an accident. This report presents the radiation levels measured around all facilities in the Network for the first quarter of 1992. All radiation measurements are made using small, passive detectors called thermoluminescent dosimeters (TLDs), which provide a quantitative measurement of the radiation levels in the area in which they are placed. Each site is monitored by arranging approximately 40 to 50 TLD stations in two concentric rings extending to about five miles from the facility. All TLD stations are outside the site boundary of the facility

  8. Solar radiation on a catenary collector

    Science.gov (United States)

    Crutchik, M.; Appelbaum, J.

    1992-01-01

    A tent-shaped structure with a flexible photovoltaic blanket acting as a catenary collector is presented. The shadow cast by one side of the collector produces a shadow on the other side of the collector. This self-shading effect is analyzed. The direct beam, the diffuse, and the albedo radiation on the collector are determined. An example is given for the insolation on the collector operating on Viking Lander 1 (VL1).

  9. The phase lag of temperature behind global solar radiation

    International Nuclear Information System (INIS)

    El Hussainy, F.M.

    1995-08-01

    This paper presented the relationship between the air temperature and the global solar radiation, which can be conveniently represented by the three characteristics: mean, amplitude and phase lag of the first harmonic of global radiation and air temperatures. A good correlation between the air temperature and the global solar radiation has been found when the phase lag between them is nearly of 30 days. (author). 4 refs, 9 figs, 1 tab

  10. Optimizing Re-planning Operation for Smart House Applying Solar Radiation Forecasting

    Directory of Open Access Journals (Sweden)

    Atsushi Yona

    2014-08-01

    Full Text Available This paper proposes the re-planning operation method using Tabu Search for direct current (DC smart house with photovoltaic (PV, solar collector (SC, battery and heat pump system. The proposed method is based on solar radiation forecasting using reported weather data, Fuzzy theory and Recurrent Neural Network. Additionally, the re-planning operation method is proposed with consideration of solar radiation forecast error, battery and inverter losses. In this paper, it is assumed that the installation location for DC smart house is Okinawa, which is located in Southwest Japan. The validity of proposed method is confirmed by comparing the simulation results.

  11. NRC TLD Direct Radiation Monitoring Network

    International Nuclear Information System (INIS)

    Struckmeyer, R.; McNamara, N.

    1991-04-01

    This report presents the results of the NRC [Nuclear Regulatory Commission] Direct Radiation Monitoring Network for the fourth quarter of 1990. It provides the ambient radiation levels measured in the vicinity of 75 sites throughout the United States. In addition, it describes the equipment used, monitoring station selection criteria, characterization of the dosimeter response, calibration procedures, statistical methods, intercomparison, and quality assurance program. 3 figs., 4 tabs

  12. Series-parallel method of direct solar array regulation

    Science.gov (United States)

    Gooder, S. T.

    1976-01-01

    A 40 watt experimental solar array was directly regulated by shorting out appropriate combinations of series and parallel segments of a solar array. Regulation switches were employed to control the array at various set-point voltages between 25 and 40 volts. Regulation to within + or - 0.5 volt was obtained over a range of solar array temperatures and illumination levels as an active load was varied from open circuit to maximum available power. A fourfold reduction in regulation switch power dissipation was achieved with series-parallel regulation as compared to the usual series-only switching for direct solar array regulation.

  13. Estimating Roof Solar Energy Potential in the Downtown Area Using a GPU-Accelerated Solar Radiation Model and Airborne LiDAR Data

    Directory of Open Access Journals (Sweden)

    Yan Huang

    2015-12-01

    Full Text Available Solar energy, as a clean and renewable resource is becoming increasingly important in the global context of climate change and energy crisis. Utilization of solar energy in urban areas is of great importance in urban energy planning, environmental conservation, and sustainable development. However, available spaces for solar panel installation in cities are quite limited except for building roofs. Furthermore, complex urban 3D morphology greatly affects sunlit patterns on building roofs, especially in downtown areas, which makes the determination of roof solar energy potential a challenging task. The object of this study is to estimate the solar radiation on building roofs in an urban area in Shanghai, China, and select suitable spaces for installing solar panels that can effectively utilize solar energy. A Graphic Processing Unit (GPU-based solar radiation model named SHORTWAVE-C simulating direct and non-direct solar radiation intensity was developed by adding the capability of considering cloud influence into the previous SHORTWAVE model. Airborne Light Detection and Ranging (LiDAR data was used as the input of the SHORTWAVE-C model and to investigate the morphological characteristics of the study area. The results show that the SHORTWAVE-C model can accurately estimate the solar radiation intensity in a complex urban environment under cloudy conditions, and the GPU acceleration method can reduce the computation time by up to 46%. Two sites with different building densities and rooftop structures were selected to illustrate the influence of urban morphology on the solar radiation and solar illumination duration. Based on the findings, an object-based method was implemented to identify suitable places for rooftop solar panel installation that can fully utilize the solar energy potential. Our study provides useful strategic guidelines for the selection and assessment of roof solar energy potential for urban energy planning.

  14. Solar radiation in Germany - observed trends and an assessment of the causes. Pt. 2; Detailed trend analysis for Hamburg

    Energy Technology Data Exchange (ETDEWEB)

    Grabbe, G C [Hamburg Univ. (Germany). Meteorologisches Inst.; Grassl, H [Hamburg Univ. (Germany). Meteorologisches Inst. Max-Planck-Institut fuer Meteorologie, Hamburg (Germany)

    1994-02-01

    In Part II, more detailed observations of solar radiation hourly averages of Hamburg were analysed. Global solar radiation, strongly influenced by clouds, decreased with a low significance between 1964 and 1989. The significance of the trend of increasing direct solar radiation in the same period is very weak, because the clouds play the dominant role. The diffuse solar radiation, which is a safe indicator for trends in solar irradiance, because it is relatively independent of the weather, decreased between 1964 and 1989. The reasons for this decrease are the measures to clean the air. Between 1975 and 1987 the diffuse solar radiation increased slightly. The reason for this fact is a doubling of optically active aerosol particles in the atmospheric boundary layer in this time period. (orig.)

  15. Synergistic effect of solar radiation and solar heating to disinfect drinking water sources.

    Science.gov (United States)

    Rijal, G K; Fujioka, R S

    2001-01-01

    Waterborne diseases are still common in developing countries as drinking water sources are contaminated and feasible means to reliably treat and disinfect these waters are not available. Many of these developing countries are in the tropical regions of the world where sunlight is plentiful. The objective of this study was to evaluate the effectiveness of combining solar radiation and solar heating to disinfect contaminated water using a modified Family Sol*Saver System (FSP). The non-UV transmittable cover sheet of the former FSP system was replaced with an UV transmittable plastic cover sheet to enable more wavelengths of sunlight to treat the water. Disinfection efficiency of both systems was evaluated based on reduction of the natural populations of faecal coliform, E. coli, enterococci, C. perfringens, total heterotrophic bacteria, hydrogen sulphide producing bacteria and FRNA virus. The results showed that under sunny and partly sunny conditions, water was heated to critical temperature (60 degrees C) in both the FSP systems inactivating more than 3 log (99.9%) of the concentrations of faecal coliform and E. coli to undetectable levels of heat worked synergistically to enhance the inactivation of faecal indicator bacteria. The relative log removal of indicator microorganism in the FSP treated water was total heterotrophic bacteria heat and radiation effects of sunlight were important in disinfecting water by solar units. The data indicated that direct radiation of sunlight worked synergistically with solar heating of the water to disinfect the water. Thus, effective disinfection was observed even when the water temperature did not reach 60 degrees C. Finally, the hydrogen sulphide test is a simple and reliable test that householders can use to determine whether their water had been sufficiently disinfected.

  16. Design and testing of an innovative solar radiation measurement device

    International Nuclear Information System (INIS)

    Badran, Omar; Al-Salaymeh, Ahmed; El-Tous, Yousif; Abdala, Wasfi

    2010-01-01

    After review of studies conducted on the solar radiation measuring systems, a new innovative instrument that would help in measuring the accurate solar radiation on horizontal surfaces has been designed and tested. An advanced instrument with ease of use and high precision that would enable the user to take the readings in terms of solar intensity (W/m 2 ) has been tested. Also, the innovative instrument can record instantaneous readings of the solar intensities as well as the averages value of the solar radiation flux during certain periods of time. The instrument based in its design on being programmed by programmable interfacing controller (PIC). Furthermore, the power supply circuit is fed by the solar energy cells and does not need an external power source.

  17. Direct solar-pumped iodine laser amplifier

    Science.gov (United States)

    Han, Kwang S.; Hwang, In Heon

    1990-01-01

    The optimum conditions of a solar pumped iodine laser are found in this research for the case of a continuous wave operation and a pulsed operation. The optimum product of the pressure(p) inside the laser tube and the tube diameter(d) was pd=40 approx. 50 torr-cm on the contrary to the case of a high intensity flashlamp pumped iodine laser where the optimum value of the product is known to be pd=150 torr-cm. The pressure-diameter product is less than 1/3 of that of the high power iodine laser. During the research period, various laser materials were also studied for solar pumping. Among the laser materials, Nd:YAG is found to have the lowest laser threshold pumping intensity of about 200 solar constant. The Rhodamine 6G was also tested as the solar pumped laser material. The threshold pumping power was measured to be about 20,000 solar constant. The amplification experiment for a continuously pumped iodine laser amplifier was performed using Vortek solar simulator and the amplification factors were measured for single pass amplification and triple pass amplification of the 15 cm long amplifier tube. The amplification of 5 was obtained for the triple pass amplification.

  18. Study on radiation flux of the receiver with a parabolic solar concentrator system

    International Nuclear Information System (INIS)

    Mao, Qianjun; Shuai, Yong; Yuan, Yuan

    2014-01-01

    Highlights: • The idea of integral dish and multi-dishes in a parabolic solar collector has been proposed. • The impacts of three factors of the receiver have been investigated. • The radiation flux distribution can benefit from a large system error. - Abstract: The solar receiver plays a key role in the performance of a solar dish electric generator. Its radiation flux distribution can directly affect the efficiency of the parabolic solar concentrator system. In this paper, radiation flux distribution of the receiver is simulated successfully using MCRT method. The impacts of incident solar irradiation, aspect ratio (the ratio of the receiver height to the receiver diameter), and system error on the radiation flux of the receiver are investigated. The parameters are studied in the following ranges: incident solar irradiation from 100 to 1100 W/m 2 , receiver aspect ratio from 0.5 to 1.5, and the system error from 0 to 10 mrad. A non-dimensional parameter Θ is defined to represent the ratio of radiation flux to incident solar irradiation. The results show that the maximum of Θ is about 200 in simulation conditions. The aspect ratio and system error have a significant impact on the radiation flux. The optimal receiver aspect ratio is 1.5 at a constant incident solar irradiation, and the maximum of radiation flux increases with decreasing system error, however, the radiation flux distribution can benefit from a large system error. Meanwhile, effects of integral dish and multi-dishes on the radiation flux distribution have been investigated. The results show that the accuracy of two cases can be ignored within the same parameters

  19. First direct detection of solar pp neutrinos by Borexino

    Energy Technology Data Exchange (ETDEWEB)

    Maneschg, Werner [Max-Planck-Institut fuer Kernphysik, Heidelberg (Germany); Collaboration: Werner Maneschg on behalf of the Borexino collaboration

    2015-07-01

    According to the Standard Solar Model (SSM) the radiative energy of our Sun is produced by a series of nuclear reactions that convert hydrogen into helium. In 99% of cases these processes are supposed to start with a fusion of two protons and the emission of a positron and a low-energy neutrino. These so-called pp neutrinos vastly outnumber those emitted in other sub-reactions, but only the large volume organic liquid scintillator detector Borexino has recently succeeded to perform a spectroscopic and direct measurement of them. The present talk reviews the procedure adopted by the Borexino collaboration to detect pp neutrinos. The key requirements, i.e. unprecedented radiopurity levels at low energies and a precise spectral description of the main background arising from 14C decays, and their fulfillment are discussed. The measured pp neutrino flux is then compared with the predictions of the SSM including neutrino oscillation mechanisms, and with the solar luminosity constraint deduced from photospheric observations.

  20. Direct solar steam generation inside evacuated tube absorber

    Directory of Open Access Journals (Sweden)

    Khaled M. Bataineh

    2016-12-01

    Full Text Available Direct steam generation by solar radiation falling on absorber tube is studied in this paper. A system of single pipe covered by glass material in which the subcooled undergoes heating and evaporation process is analyzed. Mathematical equations are derived based on energy, momentum and mass balances for system components. A Matlab code is built to simulate the flow of water inside the absorber tube and determine properties of water along the pipe. Widely accepted empirical correlations and mathematical models of turbulent flow, pressure drop for single and multiphase flow, and heat transfer are used in the simulation. The influences of major parameters on the system performance are investigated. The pressure profiles obtained by present numerical solution for each operation condition (3 and 10 MPa matches very well experimental data from the DISS system of Plataforma Solar de Almería. Furthermore, results obtained by simulation model for pressure profiles are closer to the experimental data than those predicted by already existed other numerical model.

  1. Decontamination of drinking water by direct heating in solar panels.

    Science.gov (United States)

    Fjendbo Jørgensen, A J; Nøhr, K; Sørensen, H; Boisen, F

    1998-09-01

    A device was developed for direct heating of water by solar radiation in a flow-through system of copper pipes. An adjustable thermostat valve prevents water below the chosen temperature from being withdrawn. The results show that it is possible to eliminate coliform and thermotolerant coliform bacteria from naturally contaminated river water by heating to temperatures of 65 degrees C or above. Artificial additions of Salmonella typhimurium, Streptococcus faecalis and Escherichia coli to contaminated river water were also inactivated after heating to 65 degrees C and above. The total viable count could be reduced by a factor of 1000. The heat-resistant bacteria isolated from the Mlalakuva River (Tanzania) were spore-forming bacteria which exhibited greater heat resistance than commonly used test bacteria originating from countries with colder climates. To provide a good safety margin it is recommended that an outlet water temperature of 75 degrees C be used. At that temperature the daily production was about 501 of decontaminated water per m2 of solar panel, an amount that could be doubled by using a heat exchanger to recycle the heat.

  2. Solar radiation is inversely associated with inflammatory bowel disease admissions.

    Science.gov (United States)

    Jaime, Francisca; Riutort, Maria C; Alvarez-Lobos, Manuel; Hoyos-Bachiloglu, Rodrigo; Camargo, Carlos A; Borzutzky, Arturo

    To explore the associations between latitude and solar radiation with inflammatory bowel disease admission rates in Chile, the country with the largest variation in solar radiation in the world. This is an ecological study, which included data on all hospital-admitted population for inflammatory bowel disease between 2001 and 2012, according to different latitudes and solar radiation exposures in Chile. The data were acquired from the national hospital discharge database from the Department of Health Statistics and Information of the Chilean Ministry of Health. Between 2001 and 2012 there were 12,869 admissions due to inflammatory bowel disease (69% ulcerative colitis, 31% Crohn's disease). Median age was 36 years (IQR: 25-51); 57% were female. The national inflammatory bowel disease admission rate was 6.52 (95% CI: 6.40-6.63) per 100,000 inhabitants with increasing rates over the 12-year period. In terms of latitude, the highest admission rates for pediatric ulcerative colitis and Crohn's disease, as well as adult ulcerative colitis, were observed in the southernmost region with lowest annual solar radiation. Linear regression analysis showed that regional solar radiation was inversely associated with inflammatory bowel disease admissions in Chile (β: -.44, p = .03). Regional solar radiation was inversely associated with inflammatory bowel disease admission rates in Chile; inflammatory bowel disease admissions were highest in the southernmost region with lowest solar radiation. Our results support the potential role of vitamin D deficiency on inflammatory bowel disease flares.

  3. Materials That Enhance Efficiency and Radiation Resistance of Solar Cells

    Science.gov (United States)

    Sun, Xiadong; Wang, Haorong

    2012-01-01

    A thin layer (approximately 10 microns) of a novel "transparent" fluorescent material is applied to existing solar cells or modules to effectively block and convert UV light, or other lower solar response waveband of solar radiation, to visible or IR light that can be more efficiently used by solar cells for additional photocurrent. Meanwhile, the layer of fluorescent coating material remains fully "transparent" to the visible and IR waveband of solar radiation, resulting in a net gain of solar cell efficiency. This innovation alters the effective solar spectral power distribution to which an existing cell gets exposed, and matches the maximum photovoltaic (PV) response of existing cells. By shifting a low PV response waveband (e.g., UV) of solar radiation to a high PV response waveband (e.g. Vis-Near IR) with novel fluorescent materials that are transparent to other solar-cell sensitive wavebands, electrical output from solar cells will be enhanced. This approach enhances the efficiency of solar cells by converting UV and high-energy particles in space that would otherwise be wasted to visible/IR light. This innovation is a generic technique that can be readily implemented to significantly increase efficiencies of both space and terrestrial solar cells, without incurring much cost, thus bringing a broad base of economical, social, and environmental benefits. The key to this approach is that the "fluorescent" material must be very efficient, and cannot block or attenuate the "desirable" and unconverted" waveband of solar radiation (e.g. Vis-NIR) from reaching the cells. Some nano-phosphors and novel organometallic complex materials have been identified that enhance the energy efficiency on some state-of-the-art commercial silicon and thin-film-based solar cells by over 6%.

  4. Modeling solar radiation at the Earth's surface recent advances

    CERN Document Server

    Badescu, Viorel

    2008-01-01

    Solar radiation data is important for a wide range of applications, e.g. in engineering, agriculture, health sector, and in many fields of the natural sciences. A few examples showing the diversity of applications may include: architecture and building design e.g. air conditioning and cooling systems; solar heating system design and use; solar power generation; weather and climate prediction models; evaporation and irrigation; calculation of water requirements for crops; monitoring plant growth and disease control; skin cancer research. Solar radiation data must be provided in a variety of f

  5. CLASSICS Handbook of Solar Radiation Data for India

    Indian Academy of Sciences (India)

    Srimath

    Handbook of Solar Radiation Data for India. By Anna Mani. CHAPTER 1. Introduction. 1.1. The sun and its radiation. The electromagnetic radiation emitted by the sun covers a very large range of wave- lengths, from radiowaves through the infrared, visible and ultraviolet to X-rays and gamma rays. However, 99 per cent of ...

  6. Approach to interior design for passive direct gain solar homes

    Energy Technology Data Exchange (ETDEWEB)

    Kachadorian, C.C.

    1980-01-01

    In response to requests from buyers and builders of direct gain passive solar homes interior design criteria either specific to, or emphasized by, passive solar buildings are investigated. Problems of high sunlight penetration, secondary illumination, material selection, sound control and psychology are approached. Material deterioration, fading, glare, noise, and a sense of spacial confinement can be minimized, contributing to the appeal and saleability of passive solar homes.

  7. Heat Pumps With Direct Expansion Solar Collectors

    Science.gov (United States)

    Ito, Sadasuke

    In this paper, the studies of heat pump systems using solar collectors as the evaporators, which have been done so far by reserchers, are reviwed. Usually, a solar collector without any cover is preferable to one with ac over because of the necessity of absorbing heat from the ambient air when the intensity of the solar energy on the collector is not enough. The performance of the collector depends on its area and the intensity of the convective heat transfer on the surface. Fins are fixed on the backside of the collector-surface or on the tube in which the refrigerant flows in order to increase the convective heat transfer. For the purpose of using a heat pump efficiently throughout year, a compressor with variable capacity is applied. The solar assisted heat pump can be used for air conditioning at night during the summer. Only a few groups of people have studied cooling by using solar assisted heat pump systems. In Japan, a kind of system for hot water supply has been produced commercially in a company and a kind of system for air conditioning has been installed in buildings commercially by another company.

  8. Estimation of monthly solar radiation distribution for solar energy system analysis

    International Nuclear Information System (INIS)

    Coskun, C.; Oktay, Z.; Dincer, I.

    2011-01-01

    The concept of probability density frequency, which is successfully used for analyses of wind speed and outdoor temperature distributions, is now modified and proposed for estimating solar radiation distributions for design and analysis of solar energy systems. In this study, global solar radiation distribution is comprehensively analyzed for photovoltaic (PV) panel and thermal collector systems. In this regard, a case study is conducted with actual global solar irradiation data of the last 15 years recorded by the Turkish State Meteorological Service. It is found that intensity of global solar irradiance greatly affects energy and exergy efficiencies and hence the performance of collectors. -- Research highlights: → The first study to apply global solar radiation distribution in solar system analyzes. → The first study showing global solar radiation distribution as a parameter of the solar irradiance intensity. → Time probability intensity frequency and probability power distribution do not have similar distribution patterns for each month. → There is no relation between the distribution of annual time lapse and solar energy with the intensity of solar irradiance.

  9. Evaluation of solar radiation abundance and electricity production capacity for application and development of solar energy

    Energy Technology Data Exchange (ETDEWEB)

    Rahim, Mustamin [Department of Architecture, Khairun University, Ternate (Indonesia); Environmental and Renewable Energy Systems Division, Graduate School of Engineering, Gifu University (Japan); Yoshino, Jun; Yasuda, Takashi [Environmental and Renewable Energy Systems Division, Graduate School of Engineering, Gifu University (Japan)

    2012-07-01

    This study was undertaken to analyze solar radiation abundance to ascertain the potential of solar energy as an electrical energy resource. Local weather forecasting for predicting solar radiation is performed using a meteorological model MM5. The prediction results are compared with observed results obtained from the Japan Meteorological Agency for verification of the data accuracy. Results show that local weather forecasting has high accuracy. Prediction of solar radiation is similar with observation results. Monthly average values of solar radiation are sufficiently good during March–September. Electrical energy generated by photovoltaic cells is almost proportional to the solar radiation amount. Effects of clouds on solar radiation can be removed by monthly averaging. The balance between supply and demand of electricity can be estimated using a standard curve obtained from the temporal average. When the amount of solar radiation every hour with average of more than 100 km radius area does not yield the standard curve, we can estimate the system of storage and auxiliary power necessary based on the evaluated results of imbalance between supply and demand.

  10. Direct and semi-direct radiative forcing of smoke aerosols over clouds

    Directory of Open Access Journals (Sweden)

    E. M. Wilcox

    2012-01-01

    Full Text Available Observations from Earth observing satellites indicate that dark carbonaceous aerosols that absorb solar radiation are widespread in the tropics and subtropics. When these aerosols mix with clouds, there is generally a reduction of cloudiness owing to absorption of solar energy in the aerosol layer. Over the subtropical South Atlantic Ocean, where smoke from savannah burning in southern Africa resides above a persistent deck of marine stratocumulus clouds, radiative heating of the smoke layer leads to a thickening of the cloud layer. Here, satellite observations of the albedo of overcast scenes of 25 km2 size or larger are combined with additional satellite observations of clouds and aerosols to estimate the top-of-atmosphere direct radiative forcing attributable to presence of dark aerosol above bright cloud, and the negative semi-direct forcing attributable to the thickening of the cloud layer. The average positive direct radiative forcing by smoke over an overcast scene is 9.2±6.6 W m−2 for cases with an unambiguous signal of absorbing aerosol over cloud in passive ultraviolet remote sensing observations. However, cloud liquid water path is enhanced by 16.3±7.7 g m−2 across the range of values for sea surface temperature for cases of smoke over cloud. The negative radiative forcing associated with this semi-direct effect of smoke over clouds is estimated to be −5.9±3.5 W m−2. Therefore, the cooling associated with the semi-direct cloud thickening effect compensates for greater than 60 % of the direct radiative effect. Accounting for the frequency of occurrence of significant absorbing aerosol above overcast scenes leads to an estimate of the average direct forcing of 1.0±0.7 W m−2 contributed by these scenes averaged over the subtropical southeast Atlantic Ocean during austral winter. The regional average of the negative semi-direct forcing is −0.7±0.4 W m−2

  11. Evaluation of the National Solar Radiation Database (NSRDB): 1998-2015

    Energy Technology Data Exchange (ETDEWEB)

    Habte, Aron [National Renewable Energy Lab. (NREL), Golden, CO (United States); Sengupta, Manajit [National Renewable Energy Lab. (NREL), Golden, CO (United States); Lopez, Anthony [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2017-04-01

    This paper validates the performance of the physics-based Physical Solar Model (PSM) data set in the National Solar Radiation Data Base (NSRDB) to quantify the accuracy of the magnitude and the spatial and temporal variability of the solar radiation data. Achieving higher penetrations of solar energy on the electric grid and reducing integration costs requires accurate knowledge of the available solar resource. Understanding the impacts of clouds and other meteorological constituents on the solar resource and quantifying intra-/inter-hour, seasonal, and interannual variability are essential for accurately designing utility-scale solar energy projects. Solar resource information can be obtained from ground-based measurement stations and/or from modeled data sets. The availability of measurements is scarce, both temporally and spatially, because it is expensive to maintain a high-density solar radiation measurement network that collects good quality data for long periods of time. On the other hand, high temporal and spatial resolution gridded satellite data can be used to estimate surface radiation for long periods of time and is extremely useful for solar energy development. Because of the advantages of satellite-based solar resource assessment, the National Renewable Energy Laboratory developed the PSM. The PSM produced gridded solar irradiance -- global horizontal irradiance (GHI), direct normal irradiance (DNI), and diffuse horizontal irradiance -- for the NSRDB at a 4-km by 4-km spatial resolution and half-hourly temporal resolution covering the 18 years from 1998-2015. The NSRDB also contains additional ancillary meteorological data sets, such as temperature, relative humidity, surface pressure, dew point, and wind speed. Details of the model and data are available at https://nsrdb.nrel.gov. The results described in this paper show that the hourly-averaged satellite-derived data have a systematic (bias) error of approximately +5% for GHI and less than +10% for

  12. Protection from solar ultraviolet radiation by clothing

    Energy Technology Data Exchange (ETDEWEB)

    Pailthorpe, M. [New South Wales Univ., Kensington, NSW (Australia)

    1996-12-31

    The recently published Australia/New Zealand Standard AS/NZS 4399: l996 `Sun Protective Clothing - Evaluation and Classification` specifies an in vitro spectrophotometric method for the measurement of the ultraviolet (WR) transmission of textiles. Ultraviolet Protection Factors (UPF) are then calculated by convolving the UVR transmission data with standard CIE erythemal response data and ARL solar irradiance data. At the present time the scope of the standard is limited to loose fitting dry clothing. Virtually every textile parameter has an influence on the UPF of the finished garment and hence on the protection afforded to skin from the harmful effects of solar UVR radiation. Textile parameters such as fibre type, the method of spinning the yarn, fabric structure, cover factor, colorant, UVR absorbers and finishing methods determine the UPF of the fabric and hence must be controlled from batch to batch. Since garments generally shrink when washed, multiple wearing and washing cycles usually cause an increase in fabric UPF. Adventitious soiling of fabrics and the absorption of certain components of domestic laundry formulations, e g fluorescent whitening agents, increase fabric UPF ratings. Garments with a high degree of elasticity, e g nylon/lycra sportswear, that are stretched on to fit, will obviously have lower UPFs when stretched than when relaxed. In general fabrics worn in a wet state provide lower protection than when worn dry. On Australia`s most extreme summer day it has been estimated that there are 30 MEDs (minimal erythemal doses) in a dawn to dusk exposure. Thus outdoor workers should be provided with UPF 30 clothing, or better. Results from recent experiments using SK-II hairless mice dressed in UPF 50 `sunsuits` have shown that the mice developed no sun induced skin cancers on the skin areas protected by the UPF 50 fabric whereas multiple tumours developed on the unprotected skin.

  13. Protection from solar ultraviolet radiation by clothing

    International Nuclear Information System (INIS)

    Pailthorpe, M.

    1996-01-01

    The recently published Australia/New Zealand Standard AS/NZS 4399: l996 'Sun Protective Clothing - Evaluation and Classification' specifies an in vitro spectrophotometric method for the measurement of the ultraviolet (WR) transmission of textiles. Ultraviolet Protection Factors (UPF) are then calculated by convolving the UVR transmission data with standard CIE erythemal response data and ARL solar irradiance data. At the present time the scope of the standard is limited to loose fitting dry clothing. Virtually every textile parameter has an influence on the UPF of the finished garment and hence on the protection afforded to skin from the harmful effects of solar UVR radiation. Textile parameters such as fibre type, the method of spinning the yarn, fabric structure, cover factor, colorant, UVR absorbers and finishing methods determine the UPF of the fabric and hence must be controlled from batch to batch. Since garments generally shrink when washed, multiple wearing and washing cycles usually cause an increase in fabric UPF. Adventitious soiling of fabrics and the absorption of certain components of domestic laundry formulations, e g fluorescent whitening agents, increase fabric UPF ratings. Garments with a high degree of elasticity, e g nylon/lycra sportswear, that are stretched on to fit, will obviously have lower UPFs when stretched than when relaxed. In general fabrics worn in a wet state provide lower protection than when worn dry. On Australia's most extreme summer day it has been estimated that there are 30 MEDs (minimal erythemal doses) in a dawn to dusk exposure. Thus outdoor workers should be provided with UPF 30 clothing, or better. Results from recent experiments using SK-II hairless mice dressed in UPF 50 'sunsuits' have shown that the mice developed no sun induced skin cancers on the skin areas protected by the UPF 50 fabric whereas multiple tumours developed on the unprotected skin

  14. A simple solar radiation index for wildlife habitat studies

    Science.gov (United States)

    Keating, Kim A.; Gogan, Peter J.; Vore, John N.; Irby, Lynn R.

    2007-01-01

    Solar radiation is a potentially important covariate in many wildlife habitat studies, but it is typically addressed only indirectly, using problematic surrogates like aspect or hillshade. We devised a simple solar radiation index (SRI) that combines readily available information about aspect, slope, and latitude. Our SRI is proportional to the amount of extraterrestrial solar radiation theoretically striking an arbitrarily oriented surface during the hour surrounding solar noon on the equinox. Because it derives from first geometric principles and is linearly distributed, SRI offers clear advantages over aspect-based surrogates. The SRI also is superior to hillshade, which we found to be sometimes imprecise and ill-behaved. To illustrate application of our SRI, we assessed niche separation among 3 ungulate species along a single environmental axis, solar radiation, on the northern Yellowstone winter range. We detected no difference between the niches occupied by bighorn sheep (Ovis canadensis) and elk (Cervus elaphus; P = 0.104), but found that mule deer (Odocoileus hemionus) tended to use areas receiving more solar radiation than either of the other species (P solar radiation component.

  15. Numerical simulation of variance of solar radiation and its influence on wheat growth

    Science.gov (United States)

    Zhang, Xuefen; Wang, Chunyi; Du, Zixuan; Zhai, Wei

    2007-09-01

    The growth of crops is directly related to solar radiation whose variances influence the photosynthesis of crops and the growth momentum thereof. This dissertation has Zhengzhou, which located in the Huanghuai Farmland Ecological System of China, as an example to analyze the rules of variances of total solar radiation, direct radiation and diffusive radiation. With the help of linear trend fitting, it is identified that total radiation (TR) drops as a whole at a rate of 1.6482J/m2. Such drop has been particularly apparent in recent years with a period of 7 to 16 years; diffusive radiation (DF) tends to increase at a rate of 15.149 J/m2 with a period of 20 years; direct radiation (DR) tends to drop at a rate of 15.843 J/m2 without apparent period. The total radiation has been on the decrease ever since 1980 during the growth period of wheat. Having modified relevant Parameter in the Carbon and Nitrogen Biogeochemistry in Agroecosystems Model (DNDC) model and simulated the influence of solar radiation variances on the development phase, leaf area index (LAI), grain weight, etc during the growth period of wheat, it is found that solar radiation is in positive proportion to LAI and grain weight (GRNWT) but not apparently related to development phase (DP). The change of total radiation delays the maximization of wheat LAI, reduces wheat LAI before winter but has no apparent effect in winter and decreases wheat LAI from jointing period to filling period; it has no apparent influence on grain formation at the early stage of grain formation, slows down the weight increase of grains during the filling period and accelerates the weight increase of grains at the end of filling period. Variance of radiations does not affect the DP of wheat much.

  16. Effects of solar radiation pressure torque on the rotational motion of an artificial satellite

    Science.gov (United States)

    Zanardi, Maria Cecilia F. P. S.; Vilhenademoraes, Rodolpho

    1992-01-01

    The motion of an artificial satellite about its center of mass is studied considering torques due to the gravity gradient and direct solar radiation pressure. A model for direct solar radiation torque is derived for a circular cylindrical satellite. An analytical solution is obtained by the method of variation of the parameters. This solution shows that the angular variables have secular variation but that the modulus of the rotational angular momentum, the projection of rotational angular momentum on the z axis of the moment of inertia and inertial axis z, suffer only periodic variations. Considering a hypothetical artificial satellite, a numerical application is demonstrated.

  17. Radiative cooling of solar absorbers using a visibly transparent photonic crystal thermal blackbody

    Science.gov (United States)

    Zhu, Linxiao; Raman, Aaswath P.; Fan, Shanhui

    2015-01-01

    A solar absorber, under the sun, is heated up by sunlight. In many applications, including solar cells and outdoor structures, the absorption of sunlight is intrinsic for either operational or aesthetic considerations, but the resulting heating is undesirable. Because a solar absorber by necessity faces the sky, it also naturally has radiative access to the coldness of the universe. Therefore, in these applications it would be very attractive to directly use the sky as a heat sink while preserving solar absorption properties. Here we experimentally demonstrate a visibly transparent thermal blackbody, based on a silica photonic crystal. When placed on a silicon absorber under sunlight, such a blackbody preserves or even slightly enhances sunlight absorption, but reduces the temperature of the underlying silicon absorber by as much as 13 °C due to radiative cooling. Our work shows that the concept of radiative cooling can be used in combination with the utilization of sunlight, enabling new technological capabilities. PMID:26392542

  18. New directions for space solar power

    Science.gov (United States)

    Mankins, John C.

    2009-07-01

    Several of the central issues associated with the eventual realization of the vision of solar power from space for terrestrial markets resolve around the expect costs associated with the assembly, inspection, maintenance and repair of future solar power satellite (SPS) stations. In past studies (for example, NASA's "Fresh Look Study", c. 1995-1997) efforts were made to reduce both the scale and mass of large, systems-level interfaces (e.g., the power management and distribution (PMAD) system) and on-orbit fixed infrastructures through the use of modular systems strategies. These efforts have had mixed success (as reflected in the projected on-orbit mass of various systems concepts. However, the author remains convinced of the importance of modular strategies for exceptionally large space systems in eventually realizing the vision of power from space. This paper will introduce some of the key issues associated with cost-competitive space solar power in terrestrial markets. It will examine some of the relevant SPS concepts and will assess the 'pros and cons' of each in terms of space assembly, maintenance and servicing (SAMS) requirements. The paper discusses at a high level some relevant concepts and technologies that may play r role in the eventual, successful resolution of these challenges. The paper concludes with an example of the kind of novel architectural approach for space solar power that is needed.

  19. Direct solar-pumped iodine laser amplifier

    Science.gov (United States)

    Han, Kwang S.; Hwang, In Heon; Kim, Khong Hon; Stock, Larry V.

    1988-01-01

    A XeCl laser pumped iodine laser oscillator was developed which will be incorporated into the Master Oscillator Power Amplifier (MOPA) system. The developed XeCl laser produces output energy of about 60 mJ per pulse. The pulse duration was about 10 nsec. The kinetic model for the solar-pumped laser was refined and the algorithm for the calculation of a set of rate equations was improved to increase the accuracy and the efficiency of the calculation. The improved algorithm was applied to explain the existing experimental data taken from a flashlamp pumped iodine laser for three kinds of lasants, i-C3F7I, n-C4F9I, and t-C4F9I. Various solid laser materials were evaluated for solar-pumping. The materials studied were Nd:YAG, Nd:YLF, and Cr:Nd:GSGG crystals. The slope efficiency of 0.17 percent was measured for the Nd:YLF near the threshold pump intensity which was 211 solar constants (29W/sq cm). The threshold pump intensity of the Nd:YAG was measured to be 236 solar constants (32W/sq cm) and the near-threshold slope efficiency was 0.12 percent. True CW laser operation of Cr:Nd:GSGG was possible only at pump intensities less than or equal to 1,500 solar constants (203 W/sq cm). This fact was attributed to the high thermal focusing effect of the Cr:Nd:GSGG rod.

  20. Concrete Hydration Heat Analysis for RCB Basemat Considering Solar Radiation

    International Nuclear Information System (INIS)

    Lee, Seong-Cheol; Son, Yong-Ki; Choi, Seong-Cheol

    2015-01-01

    The NPP especially puts an emphasis on concrete durability for structural integrity. It has led to higher cementitious material contents, lower water-cementitious-material ratios, and deeper cover depth over reinforcing steel. These requirements have resulted in more concrete placements that are subject to high internal temperatures. The problem with high internal temperatures is the increase in the potential for thermal cracking that can decrease concrete's long-term durability and ultimate strength. Thermal cracking negates the benefits of less permeable concrete and deeper cover by providing a direct path for corrosion-causing agents to reach the reinforcing steel. The purpose of this study is to develop how to analyze and estimate accurately concrete hydration heat of the real-scale massive concrete with wide large plane. An analysis method considering concrete placement sequence was studied and solar radiation effects on the real-scale massive concrete with wide large plane were reviewed through the analytical method. In this study, the measured temperatures at the real scale structure and the analysis results of concrete hydration heat were compared. And thermal stress analysis was conducted. Through the analysis, it was found that concrete placement duration, sequence and solar radiation effects should be considered to get the accurate concrete peak temperature, maximum temperature differences and crack index

  1. Modelling radiative heat transfer inside a basin type solar still

    International Nuclear Information System (INIS)

    Madhlopa, A.

    2014-01-01

    Radiative heat transfer inside a basin type solar still has been investigated using two models with (model 1) and without (model 2) taking into account optical view factors. The coefficient of radiative heat exchange (h r,w-gc ) between the water and cover surfaces of a practical solar still was computed using the two models. Simulation results show that model 1 yields lower values of h r,w-gc and the root mean square error than model 2. It is therefore concluded that the accuracy of modelling the performance of a basin-type solar still can be improved by incorporating view factors. - Highlights: • Radiative heat transfer in a basin type solar still has been investigated. • Two models with and without view factors were used. • The model with view factors exhibits a lower magnitude of root mean square error. • View factors affect the accuracy of modelling the performance of the solar still

  2. Solar radiation and its penetration in a tropical estuary

    Digital Repository Service at National Institute of Oceanography (India)

    Qasim, S.Z.; Bhattathiri, P.M.A.; Abidi, S.A.H.

    The Cochin Backwater which is an estuarine area on the west coast of India receives maximum solar radiation from December to March and minimum from June to September. During the monsoon months the estuary becomes highly turbid as a result...

  3. The growth of solar radiated yeast

    Energy Technology Data Exchange (ETDEWEB)

    Kraft, T.

    1995-09-01

    This researcher plans to determine if solar radiation affects the growth of yeast. The irradiated yeast was obtained from a sample exposed in space during a Space Shuttle flight of September 9-20, 1994. Further, the control groups were held at: (1) Goddard Space Flight Center (GSFC) in Greenbelt, Maryland; and (2) South Dakota School of Mines and Technology. The procedure used was based on the fact that yeast is most often used in consumable baked goods. Therefore, the yeast was incorporated into a basic Betty Crocker bread recipe. Data was collected by placing measured amounts of dough into sample containers with fifteen minute growth in height measurements collected and recorded. This researcher assumed the viability of yeast to be relative to its ability to produce carbon dioxide gas and cause the dough to rise. As all ingredients and surroundings were equal, this researcher assumed the yeast will produce the only significant difference in data collected. This researcher noted the approximate use date on all sample packages to be prior to arrival and experiment date. All dates equal, it was then assumed each would act in a similar manner of response. This assumption will allow for equally correct data collection.

  4. The growth of solar radiated yeast

    Science.gov (United States)

    Kraft, Tyrone

    1995-01-01

    This researcher plans to determine if solar radiation affects the growth of yeast. The irradiated yeast was obtained from a sample exposed in space during a Space Shuttle flight of September 9-20, 1994. Further, the control groups were held at: (1) Goddard Space Flight Center (GSFC) in Greenbelt, Maryland; and (2) South Dakota School of Mines and Technology. The procedure used was based on the fact that yeast is most often used in consumable baked goods. Therefore, the yeast was incorporated into a basic Betty Crocker bread recipe. Data was collected by placing measured amounts of dough into sample containers with fifteen minute growth in height measurements collected and recorded. This researcher assumed the viability of yeast to be relative to its ability to produce carbon dioxide gas and cause the dough to rise. As all ingredients and surroundings were equal, this researcher assumed the yeast will produce the only significant difference in data collected. This researcher noted the approximate use date on all sample packages to be prior to arrival and experiment date. All dates equal, it was then assumed each would act in a similar manner of response. This assumption will allow for equally correct data collection.

  5. Denoising solar radiation data using coiflet wavelets

    Energy Technology Data Exchange (ETDEWEB)

    Karim, Samsul Ariffin Abdul, E-mail: samsul-ariffin@petronas.com.my; Janier, Josefina B., E-mail: josefinajanier@petronas.com.my; Muthuvalu, Mohana Sundaram, E-mail: mohana.muthuvalu@petronas.com.my [Department of Fundamental and Applied Sciences, Faculty of Sciences and Information Technology, Universiti Teknologi PETRONAS, Bandar Seri Iskandar, 31750 Tronoh, Perak Darul Ridzuan (Malaysia); Hasan, Mohammad Khatim, E-mail: khatim@ftsm.ukm.my [Jabatan Komputeran Industri, Universiti Kebangsaan Malaysia, 43600 UKM Bangi, Selangor (Malaysia); Sulaiman, Jumat, E-mail: jumat@ums.edu.my [Program Matematik dengan Ekonomi, Universiti Malaysia Sabah, Beg Berkunci 2073, 88999 Kota Kinabalu, Sabah (Malaysia); Ismail, Mohd Tahir [School of Mathematical Sciences, Universiti Sains Malaysia, 11800 USM Minden, Penang (Malaysia)

    2014-10-24

    Signal denoising and smoothing plays an important role in processing the given signal either from experiment or data collection through observations. Data collection usually was mixed between true data and some error or noise. This noise might be coming from the apparatus to measure or collect the data or human error in handling the data. Normally before the data is use for further processing purposes, the unwanted noise need to be filtered out. One of the efficient methods that can be used to filter the data is wavelet transform. Due to the fact that the received solar radiation data fluctuates according to time, there exist few unwanted oscillation namely noise and it must be filtered out before the data is used for developing mathematical model. In order to apply denoising using wavelet transform (WT), the thresholding values need to be calculated. In this paper the new thresholding approach is proposed. The coiflet2 wavelet with variation diminishing 4 is utilized for our purpose. From numerical results it can be seen clearly that, the new thresholding approach give better results as compare with existing approach namely global thresholding value.

  6. An economic evaluation of solar radiation management

    Energy Technology Data Exchange (ETDEWEB)

    Aaheim, Asbjørn; Romstad, Bård; Wei, Taoyuan [CICERO — Center for International Climate and Environmental Research Oslo (Norway); Kristjánsson, Jón Egill; Muri, Helene [Department of Geosciences, University of Oslo (Norway); Niemeier, Ulrike; Schmidt, Hauke [Max Planck Institute for Meteorology, Hamburg (Germany)

    2015-11-01

    Economic evaluations of solar radiation management (SRM) usually assume that the temperature will be stabilized, with no economic impacts of climate change, but with possible side-effects. We know from experiments with climate models, however, that unlike emission control the spatial and temporal distributions of temperature, precipitation and wind conditions will change. Hence, SRM may have economic consequences under a stabilization of global mean temperature even if side-effects other than those related to the climatic responses are disregarded. This paper addresses the economic impacts of implementing two SRM technologies; stratospheric sulfur injection and marine cloud brightening. By the use of a computable general equilibrium model, we estimate the economic impacts of climatic responses based on the results from two earth system models, MPI-ESM and NorESM. We find that under a moderately increasing greenhouse-gas concentration path, RCP4.5, the economic benefits of implementing climate engineering are small, and may become negative. Global GDP increases in three of the four experiments and all experiments include regions where the benefits from climate engineering are negative.

  7. Public understanding of solar radiation management

    International Nuclear Information System (INIS)

    Mercer, A M; Keith, D W; Sharp, J D

    2011-01-01

    We report the results of the first large-scale international survey of public perception of geoengineering and solar radiation management (SRM). Our sample of 3105 individuals in the United States, Canada and the United Kingdom was recruited by survey firms that administer internet surveys to nationally representative population samples. Measured familiarity was higher than expected, with 8% and 45% of the population correctly defining the terms geoengineering and climate engineering respectively. There was strong support for allowing the study of SRM. Support decreased and uncertainty rose as subjects were asked about their support for using SRM immediately, or to stop a climate emergency. Support for SRM is associated with optimism about scientific research, a valuing of SRM's benefits and a stronger belief that SRM is natural, while opposition is associated with an attitude that nature should not be manipulated in this way. The potential risks of SRM are important drivers of public perception with the most salient being damage to the ozone layer and unknown risks. SRM is a new technology and public opinions are just forming; thus all reported results are sensitive to changes in framing, future information on risks and benefits, and changes to context.

  8. An economic evaluation of solar radiation management

    International Nuclear Information System (INIS)

    Aaheim, Asbjørn; Romstad, Bård; Wei, Taoyuan; Kristjánsson, Jón Egill; Muri, Helene; Niemeier, Ulrike; Schmidt, Hauke

    2015-01-01

    Economic evaluations of solar radiation management (SRM) usually assume that the temperature will be stabilized, with no economic impacts of climate change, but with possible side-effects. We know from experiments with climate models, however, that unlike emission control the spatial and temporal distributions of temperature, precipitation and wind conditions will change. Hence, SRM may have economic consequences under a stabilization of global mean temperature even if side-effects other than those related to the climatic responses are disregarded. This paper addresses the economic impacts of implementing two SRM technologies; stratospheric sulfur injection and marine cloud brightening. By the use of a computable general equilibrium model, we estimate the economic impacts of climatic responses based on the results from two earth system models, MPI-ESM and NorESM. We find that under a moderately increasing greenhouse-gas concentration path, RCP4.5, the economic benefits of implementing climate engineering are small, and may become negative. Global GDP increases in three of the four experiments and all experiments include regions where the benefits from climate engineering are negative

  9. Improved Statistical Model Of 10.7-cm Solar Radiation

    Science.gov (United States)

    Vedder, John D.; Tabor, Jill L.

    1993-01-01

    Improved mathematical model simulates short-term fluctuations of flux of 10.7-cm-wavelength solar radiation during 91-day averaging period. Called "F10.7 flux", important as measure of solar activity and because it is highly correlated with ultraviolet radiation causing fluctuations in heating and density of upper atmosphere. F10.7 flux easily measureable at surface of Earth.

  10. Monte Carlo radiative transfer simulation of a cavity solar reactor for the reduction of cerium oxide

    Energy Technology Data Exchange (ETDEWEB)

    Villafan-Vidales, H.I.; Arancibia-Bulnes, C.A.; Dehesa-Carrasco, U. [Centro de Investigacion en Energia, Universidad Nacional Autonoma de Mexico, Privada Xochicalco s/n, Col. Centro, A.P. 34, Temixco, Morelos 62580 (Mexico); Romero-Paredes, H. [Departamento de Ingenieria de Procesos e Hidraulica, Universidad Autonoma Metropolitana-Iztapalapa, Av. San Rafael Atlixco No.186, Col. Vicentina, A.P. 55-534, Mexico D.F 09340 (Mexico)

    2009-01-15

    Radiative heat transfer in a solar thermochemical reactor for the thermal reduction of cerium oxide is simulated with the Monte Carlo method. The directional characteristics and the power distribution of the concentrated solar radiation that enters the cavity is obtained by carrying out a Monte Carlo ray tracing of a paraboloidal concentrator. It is considered that the reactor contains a gas/particle suspension directly exposed to concentrated solar radiation. The suspension is treated as a non-isothermal, non-gray, absorbing, emitting, and anisotropically scattering medium. The transport coefficients of the particles are obtained from Mie-scattering theory by using the optical properties of cerium oxide. From the simulations, the aperture radius and the particle concentration were optimized to match the characteristics of the considered concentrator. (author)

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

    Science.gov (United States)

    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.

  12. Solar Activity, Ultraviolet Radiation and Consequences in Birds in Mexico City, 2001- 2002

    Science.gov (United States)

    Valdes, M.; Velasco, V.

    2008-12-01

    Anomalous behavior in commercial and pet birds in Mexico City was reported during 2002 by veterinarians at the Universidad Nacional Autonoma de Mexico. This was attributed to variations in the surrounding luminosity. The solar components, direct, diffuse, global, ultraviolet band A and B, as well as some meteorological parameters, temperature, relative humidity, and precipitation, were then analyzed at the Solar Radiation Laboratory. Although the total annual radiance of the previously mentioned radiation components did not show important changes, ultraviolet Band-B solar radiation did vary significantly. During 2001 the total annual irradiance , 61.05 Hjcm² to 58.32 Hjcm², was 1.6 standard deviations lower than one year later, in 2002 and increased above the mean total annual irradiance, to 65.75 Hjcm², 2.04 standard deviations, giving a total of 3.73 standard deviations for 2001-2002. Since these differences did not show up clearly in the other solar radiation components, daily extra-atmosphere irradiance was analyzed and used to calculate the total annual extra-atmosphere irradiance, which showed a descent for 2001. Our conclusions imply that Ultraviolet Band-B solar radiation is representative of solar activity and has an important impact on commercial activity related with birds.

  13. Estimating surface solar radiation from upper-air humidity

    Energy Technology Data Exchange (ETDEWEB)

    Kun Yang [Telecommunications Advancement Organization of Japan, Tokyo (Japan); Koike, Toshio [University of Tokyo (Japan). Dept. of Civil Engineering

    2002-07-01

    A numerical model is developed to estimate global solar irradiance from upper-air humidity. In this model, solar radiation under clear skies is calculated through a simple model with radiation-damping processes under consideration. A sky clearness indicator is parameterized from relative humidity profiles within three atmospheric sublayers, and the indicator is used to connect global solar radiation under clear skies and that under cloudy skies. Model inter-comparisons at 18 sites in Japan suggest (1) global solar radiation strongly depends on the sky clearness indicator, (2) the new model generally gives better estimation to hourly-mean solar irradiance than the other three methods used in numerical weather predictions, and (3) the new model may be applied to estimate long-term solar radiation. In addition, a study at one site in the Tibetan Plateau shows vigorous convective activities in the region may cause some uncertainties to radiation estimations due to the small-scale and short life of convective systems. (author)

  14. Prostate cancer incidence in Australia correlates inversely with solar radiation.

    Science.gov (United States)

    Loke, Tim W; Seyfi, Doruk; Sevfi, Doruk; Khadra, Mohamed

    2011-11-01

    What's known on the subject? and What does the study add? Increased sun exposure and blood levels of vitamin D have been postulated to be protective against prostate cancer. This is controversial. We investigated the relationship between prostate cancer incidence and solar radiation in non-urban Australia, and found a lower incidence in regions receiving more sunlight. In landmark ecological studies, prostate cancer mortality rates have been shown to be inversely related to ultraviolet radiation exposure. Investigators have hypothesised that ultraviolet radiation acts by increasing production of vitamin D, which inhibits prostate cancer cells in vitro. However, analyses of serum levels of vitamin D in men with prostate cancer have failed to support this hypothesis. This study has found an inverse correlation between solar radiation and prostate cancer incidence in Australia. Our population (previously unstudied) represents the third group to exhibit this correlation. Significantly, the demographics and climate of Australia differ markedly from those of previous studies conducted on men in the United Kingdom and the United States. • To ascertain if prostate cancer incidence rates correlate with solar radiation among non-urban populations of men in Australia. • Local government areas from each state and territory were selected using explicit criteria. Urban areas were excluded from analysis. • For each local government area, prostate cancer incidence rates and averaged long-term solar radiation were obtained. • The strength of the association between prostate cancer incidence and solar radiation was determined. • Among 70 local government areas of Australia, age-standardized prostate cancer incidence rates for the period 1998-2007 correlated inversely with daily solar radiation averaged over the last two decades. •  There exists an association between less solar radiation and higher prostate cancer incidence in Australia. © 2011 THE AUTHORS. BJU

  15. Spectral and directional radiation characteristics of thin-film coated isothermal semitransparent plates

    Energy Technology Data Exchange (ETDEWEB)

    Taylor, R P; Viskanta, R

    1975-01-01

    An analysis is presented for predicting the effective spectral directional radiation characteristics of an isothermal, semitransparent sheet surrounded on both sides by massive dielectrics. The sheet can be coated with an optically thin film and used as selective cover plates for solar collectors. Directional and polarization effects and the spectral transmittance and reflectance are considered. Sample results for candidate materials are presented.

  16. Directional sound radiation from substation transformers

    International Nuclear Information System (INIS)

    Maybee, N.

    2009-01-01

    This paper presented the results of a study in which acoustical measurements at two substations were analyzed to investigate the directional behaviour of typical arrays having 2 or 3 transformers. Substation transformers produce a characteristic humming sound that is caused primarily by vibration of the core at twice the frequency of the power supply. The humming noise radiates predominantly from the tank enclosing the core. The main components of the sound are harmonics of 120 Hz. Sound pressure level data were obtained for various directions and distances from the arrays, ranging from 0.5 m to over 100 m. The measured sound pressure levels of the transformer tones displayed substantial positive and negative excursions from the calculated average values for many distances and directions. The results support the concept that the directional effects are associated with constructive and destructive interference of tonal sound waves emanating from different parts of the array. Significant variations in the directional sound pattern can occur in the near field of a single transformer or an array, and the extent of the near field is significantly larger than the scale of the array. Based on typical dimensions for substation sites, the distance to the far field may be much beyond the substation boundary and beyond typical setbacks to the closest dwellings. As such, the directional sound radiation produced by transformer arrays introduces additional uncertainty in the prediction of substation sound levels at dwellings within a few hundred meters of a substation site. 4 refs., 4 figs.

  17. Estimation of potential solar radiation using 50m grid digital terrain model

    International Nuclear Information System (INIS)

    Kurose, Y.; Nagata, K.; Ohba, K.; Maruyama, A.

    1999-01-01

    To clarify the spatial distribution of solar radiation, a model to estimate the potential incoming solar radiation with 50m grid size was developed. The model is based on individual calculation of direct and diffuse solar radiation accounting for the effect of topographic shading. Using the elevation data in the area with radius 25km, which was offered by the Digital Map 50m Grid, the effect of topographic shading is estimated as angle of elevation for surrounding configuration to 72 directions. The estimated sunshine duration under clear sky conditions agreed well with observed values at AMeDAS points of Kyushu and Shikoku region. Similarly, there is a significant agreement between estimated and observed variation of solar radiation for monthly mean conditions over complex terrain. These suggest that the potential incoming solar radiation can be estimated well over complex terrain using the model. Locations of large fields over complex terrain agreed well with the area of the abundant insolation condition, which is defined by the model. The model is available for the investigation of agrometeorological resources over complex terrain. (author)

  18. Nongray radiative heat transfer analysis in the anisotropic scattering fog layer subjected to solar irradiation

    International Nuclear Information System (INIS)

    Maruyama, Shigenao; Mori, Yusuke; Sakai, Seigo

    2004-01-01

    Radiative heat transfer in the fog layer is analyzed. Direct and diffuse solar irradiation, and infrared sky flux are considered as incident radiation. Anisotropic scattering of radiation by water droplets is taken into account. Absorption and emission of radiation by water droplets and radiative gases are also considered. Furthermore, spectral dependences of radiative properties of irradiation, reflectivity, gas absorption and scattering and absorption of mist are considered. The radiation element method by ray emission model (REM 2 ) is used for the nongray radiation analysis. Net downward radiative heat flux at the sea surface and radiative equilibrium temperature distribution in the fog layer are calculated for several conditions. Transmitted solar flux decreases as liquid water content (LWC) in the fog increases. However, the value does not become zero but has the value about 60 W/m 2 . The effect of humidity and mist on radiative cooling at night is investigated. Due to high temperature and humidity condition, the radiation cooling at night is not so large even in the clear sky. Furthermore, the radiative equilibrium temperature distribution in the fog layer in the daytime is higher as LWC increases, and the inversion layer of temperature occurs

  19. Diffuse solar radiation and associated meteorological parameters in India

    Directory of Open Access Journals (Sweden)

    A. B. Bhattacharya

    Full Text Available Solar diffuse radiation data including global radiation, shortwave and longwave balances, net radiation and sunshine hours have been extensively analyzed to study the variation of diffuse radiation with turbidity and cloud discharges appearing in the form of atmospherics over the tropics. Results of surface radiation measurements at Calcutta, Poona, Delhi and Madras are presented together with some meteorological parameters. The monthly values of diffuse radiation and the monthly ratios of diffuse to global solar radiation have been examined, with a special emphasis in relation to the noise level of atmospherics at Calcutta in the very low frequency band. The results exhibit some definite seasonal changes which appear to be in close agreement with one another.

  20. New Temperature-based Models for Predicting Global Solar Radiation

    International Nuclear Information System (INIS)

    Hassan, Gasser E.; Youssef, M. Elsayed; Mohamed, Zahraa E.; Ali, Mohamed A.; Hanafy, Ahmed A.

    2016-01-01

    Highlights: • New temperature-based models for estimating solar radiation are investigated. • The models are validated against 20-years measured data of global solar radiation. • The new temperature-based model shows the best performance for coastal sites. • The new temperature-based model is more accurate than the sunshine-based models. • The new model is highly applicable with weather temperature forecast techniques. - Abstract: This study presents new ambient-temperature-based models for estimating global solar radiation as alternatives to the widely used sunshine-based models owing to the unavailability of sunshine data at all locations around the world. Seventeen new temperature-based models are established, validated and compared with other three models proposed in the literature (the Annandale, Allen and Goodin models) to estimate the monthly average daily global solar radiation on a horizontal surface. These models are developed using a 20-year measured dataset of global solar radiation for the case study location (Lat. 30°51′N and long. 29°34′E), and then, the general formulae of the newly suggested models are examined for ten different locations around Egypt. Moreover, the local formulae for the models are established and validated for two coastal locations where the general formulae give inaccurate predictions. Mostly common statistical errors are utilized to evaluate the performance of these models and identify the most accurate model. The obtained results show that the local formula for the most accurate new model provides good predictions for global solar radiation at different locations, especially at coastal sites. Moreover, the local and general formulas of the most accurate temperature-based model also perform better than the two most accurate sunshine-based models from the literature. The quick and accurate estimations of the global solar radiation using this approach can be employed in the design and evaluation of performance for

  1. Solar radiation and thermal performance of solar collectors for Denmark

    DEFF Research Database (Denmark)

    Dragsted, Janne; Furbo, Simon

    This report describes the part of the EUDP project “EUDP 11-l, Solar Resource Assessment in Denmark”, which is carried out at Department of Civil Engineering, Technical University of Denmark.......This report describes the part of the EUDP project “EUDP 11-l, Solar Resource Assessment in Denmark”, which is carried out at Department of Civil Engineering, Technical University of Denmark....

  2. Error in interpreting field chlorophyll fluorescence measurements: heat gain from solar radiation

    International Nuclear Information System (INIS)

    Marler, T.E.; Lawton, P.D.

    1994-01-01

    Temperature and chlorophyll fluorescence characteristics were determined on leaves of various horticultural species following a dark adaptation period where dark adaptation cuvettes were shielded from or exposed to solar radiation. In one study, temperature of Swietenia mahagoni (L.) Jacq. leaflets within cuvettes increased from approximately 36C to approximately 50C during a 30-minute exposure to solar radiation. Alternatively, when the leaflets and cuvettes were shielded from solar radiation, leaflet temperature declined to 33C in 10 to 15 minutes. In a second study, 16 horticultural species exhibited a lower variable: maximum fluorescence (F v :F m ) when cuvettes were exposed to solar radiation during the 30-minute dark adaptation than when cuvettes were shielded. In a third study with S. mahagoni, the influence of self-shielding the cuvettes by wrapping them with white tape, white paper, or aluminum foil on temperature and fluorescence was compared to exposing or shielding the entire leaflet and cuvette. All of the shielding methods reduced leaflet temperature and increased the F v :F m ratio compared to leaving cuvettes exposed. These results indicate that heat stress from direct exposure to solar radiation is a potential source of error when interpreting chlorophyll fluorescence measurements on intact leaves. Methods for moderating or minimizing radiation interception during dark adaptation are recommended. (author)

  3. UV radiation hardness of silicon inversion layer solar cells

    International Nuclear Information System (INIS)

    Hezel, R.

    1990-01-01

    For full utilization of the high spectral response of inversion layer solar cells in the very-short-wavelength range of the solar spectrum sufficient ultraviolet-radiation hardness is required. In addition to the charge-induced passivation achieved by cesium incorporation into the silicon nitride AR coating, in this paper the following means for further drastic reduction of UV light-induced effects in inversion layer solar cells without encapsulation are introduced and interpretations are given: increasing the nitride deposition temperature, silicon surface oxidation at low temperatures, and texture etching and using higher substrate resistivities. High UV radiation tolerance and improvement of the cell efficiency could be obtained simultaneously

  4. Modeling of Solar Radiation Management: A Comparison of Simulations Using Reduced Solar Constant and Stratospheric Sulphate Aerosols

    Science.gov (United States)

    Bala, G.; Kalidindi, S.; Modak, A.; Caldeira, K.

    2014-12-01

    Several climate modelling studies in the past have used reduction in solar constant to simulate the climatic effects of Solar Radiation Management (SRM) geoengineering. This is most likely valid only for space-based mirrors/reflectors but not for SRM methods that rely on stratospheric aerosols. In this study, we use a climate model to evaluate the differences in climate response to SRM by uniform solar constant reduction and stratospheric aerosols. The experiments are designed such that global mean warming from a doubling of atmospheric CO2 concentration (2xCO2) is nearly cancelled in each case. In such a scenario, the residual climate effects are similar when important surface and tropospheric climate variables such as temperature and precipitation are considered. However, there are significant differences in stratospheric temperature response and diffuse and direct radiation reaching the surface. A difference of 1K in the global mean stratospheric (61-9.8 hPa) temperature is simulated between the two SRM methods, with warming in the aerosol scheme and a slight cooling for sunshades. While the global mean surface diffuse radiation increases by ~23% and direct radiation decreases by about 9% in the case of aerosol SRM method, both direct and diffuse radiation decrease by similar fractional amounts (~1.0%) when solar constant is reduced. When CO2 fertilization effects from elevated CO2 concentration levels are removed, the contribution from shaded leaves to gross primary productivity (GPP) increases by 1.8 % in aerosol SRM because of increased diffuse light. However, this increase is almost offset by a 15.2% decline in sunlit contribution due to reduced direct light. Overall both the SRM simulations show similar decrease in GPP (~ 8%) and NPP (~3%) relative to 2xCO2, indicating the negligible effect of the fractional changes in direct/diffuse radiation on the overall plant productivity. Based on our modelling study, we conclude that the climate states produced by a

  5. New horizontal global solar radiation estimation models for Turkey based on robust coplot supported genetic programming technique

    International Nuclear Information System (INIS)

    Demirhan, Haydar; Kayhan Atilgan, Yasemin

    2015-01-01

    inferences on the sensitivity of the amount of global solar radiation to covariates and the magnitude and direction of effect of covariates on the global solar radiation are drawn.

  6. Solar radiation transfer and performance analysis of an optimum photovoltaic/thermal system

    International Nuclear Information System (INIS)

    Zhao Jiafei; Song Yongchen; Lam, Wei-Haur; Liu Weiguo; Liu Yu; Zhang Yi; Wang DaYong

    2011-01-01

    This paper presents the design optimization of a photovoltaic/thermal (PV/T) system using both non-concentrated and concentrated solar radiation. The system consists of a photovoltaic (PV) module using silicon solar cell and a thermal unit based on the direct absorption collector (DAC) concept. First, the working fluid of the thermal unit absorbs the solar infrared radiation. Then, the remaining visible light is transmitted and converted into electricity by the solar cell. This arrangement prevents excessive heating of the solar cell which would otherwise negatively affects its electrical efficiency. The optical properties of the working fluid were modeled based on the damped oscillator Lorentz-Drude model satisfying the Kramers-Kroenig relations. The coefficients of the model were retrieved by inverse method based on genetic algorithm, in order to (i) maximize transmission of solar radiation between 200 nm and 800 nm and (ii) maximize absorption in the infrared part of the spectrum from 800 nm to 2000 nm. The results indicate that the optimum system can effectively and separately use the visible and infrared part of solar radiation. The thermal unit absorbs 89% of the infrared radiation for photothermal conversion and transmits 84% of visible light to the solar cell for photoelectric conversion. When reducing the mass flow rate, the outflow temperature of the working fluid reaches 74 o C, the temperature of the PV module remains around 31 o C at a constant electrical efficiency about 9.6%. Furthermore, when the incident solar irradiance increases from 800 W/m 2 to 8000 W/m 2 , the system generates 196 o C working fluid with constant thermal efficiency around 40%, and the exergetic efficiency increases from 12% to 22%.

  7. Convective instability of sludge storage under evaporation and solar radiation

    Science.gov (United States)

    Tsiberkin, Kirill; Tatyana, Lyubimova

    2014-05-01

    The sludge storages are an important part of production cycle at salt manufacturing, water supply, etc. A quality of water in the storage depends on mixing of pure water and settled sediment. One of the leading factors is thermal convection. There are two main mechanisms of the layer instability exist. First, it is instability of water due to evaporation from the free surface [1]. It cools the water from upside, increases the particles concentration and leads to the instability in the near-surface layer. Second, the sediment absorbs a solar radiation and heats the liquid from below making it unstable in the near-bottom area. We assume the initial state is the mechanical equilibrium. The water and sediment particles are motionless, the sediment forms a uniform sludge layer of thickness z0, there are no evaporation and heating by solar energy, and the temperature has a linear profile is determined by fixed upper and bottom temperatures of the layer. Taking into account the evaporation and solar radiation absorption, we obtain a non-stationary solution for the temperature using Fourier series method. The local temperature gradients increases rapidly with time, and local Rayleigh number can be estimated by thermal conduction length Lt: Raloc(z,t) = gβ(δT(z,t)/δz)L4t-/νΞ , Lt ~ √Ξt, (1) where g is gravity acceleration, β, ν and Ξ are thermal volume expansion coefficient, kinematic viscosity and thermal conductivity of the liquid, respectively. Raloc* reaches the critical value at finite time t* and water motion begins. The maximal power of solar radiation in visible band equals 230 Wt/m2 at the latitude of "Uralkalii" salt manufacturer (Berezniki, Perm Region, Russian Federation). We neglect IR and UV radiation because of its huge absorption by water [2]. The evaporation speed is found using results for shallow water reservoir [3] and meteorological data for Berezniki [4]. We get the t*~ 6 · 102 s (10 min) for the layer of 1 m depth and t*~ 2 · 103 s (40

  8. A new CM SAF Solar Surface Radiation Climate Data Set derived from Meteosat Satellite Observations

    Science.gov (United States)

    Trentmann, J.; Mueller, R. W.; Pfeifroth, U.; Träger-Chatterjee, C.; Cremer, R.

    2014-12-01

    The incoming surface solar radiation has been defined as an essential climate variable by GCOS. It is mandatory to monitor this part of the earth's energy balance, and thus gain insights on the state and variability of the climate system. In addition, data sets of the surface solar radiation have received increased attention over the recent years as an important source of information for the planning of solar energy applications. The EUMETSAT Satellite Application Facility on Climate Monitoring (CM SAF) is deriving surface solar radiation from geostationary and polar-orbiting satellite instruments. While CM SAF is focusing on the generation of high-quality long-term climate data records, also operationally data is provided in short time latency within 8 weeks. Here we present SARAH (Solar Surface Radiation Dataset - Heliosat), i.e. the new CM SAF Solar Surface Radiation data set based on Meteosat satellite observations. SARAH provides instantaneous, daily- and monthly-averaged data of the effective cloud albedo (CAL), the direct normalized solar radiation (DNI) and the solar irradiance (SIS) from 1983 to 2013 for the full view of the Meteosat satellite (i.e, Europe, Africa, parts of South America, and the Atlantic ocean). The data sets are generated with a high spatial resolution of 0.05 deg allowing for detailed regional studies, and are available in netcdf-format at no cost without restrictions at www.cmsaf.eu. We provide an overview of the data sets, including a validation against reference measurements from the BSRN and GEBA surface station networks.

  9. EVALUATION OF OPPORTUNITIES OF SOLAR ENERGETICS ON THE BASIS OF ACCURATE GROUND-BASED MEASUREMENTS OF SOLAR RADIATION

    Directory of Open Access Journals (Sweden)

    Aculinin A.

    2008-04-01

    Full Text Available Expected quantity of a solar energy received by solar panel is estimated on the basis of accurate measurements of solar radiation in Kishinev. Optimal orientation of solar panels and apparent volume of the electric power generated by solar panels are determined.

  10. Efficiency of solar radiation conversion in photovoltaic panels

    Directory of Open Access Journals (Sweden)

    Kurpaska Sławomir

    2018-01-01

    Full Text Available This paper included analysis the conversion efficiency in photovoltaic panels. The tests were done between February and June at a test stand equipped with three commonly used types of photovoltaic panels: poly- and monocrystalline silicon and with semi-conductive layer made of copper (Cu, indium (In, gallium (Ga and selenium (Se (CIGS. Five days of each month were selected for a detailed analysis. They were close to the so-called recommended day for calculations in solar power engineering. Efficiency, calculated as the yield of electrical energy in relation to solar radiation energy reaching the panels was made conditional upon solar radiation intensity and ambient temperature. It was found that as solar radiation intensity and ambient temperature increase, the efficiency of solar radiation conversion into electricity is reduced. Correlation dependence was determined for the test data obtained, describing temperature change of panels depending on climatic conditions. It was found that as panel temperature increases, the conversion efficiency is reduced. Within the tested scope of experiment conditions, the efficiency was reduced in the range between 20.1 and 22.8%. The authors also determined the average efficiency values in individual test months together with average ambient conditions of the environment where the process of solar radiation conversion took place.

  11. Radiative hazard of solar flares in the nearterrestrial cosmic space

    International Nuclear Information System (INIS)

    Kolomenskij, A.V.; Petrov, V.M.; Zil', M.V.; Eremkina, T.M.

    1978-01-01

    Simulation of radiation enviroment due to solar cosmic rays was carried out in the near-terrestrial space. Systematized are the data on cosmic ray flux and spectra detected during 19-th and 20-th cycles of solar activity. 127 flares are considered with proton fluxes of more than 10 proton/cm 2 at energies higher than 30 MeV. Obtained are distribution functions of intervals between flares, flux distribution of flares and characteristic rigidity, and also distribution of magnetic disturbances over Dsub(st)-variation amplitude. The totality of these distributions presents the statistic model of radiation enviroment caused by solar flare protons for the period of maximum solar .activity. This model is intended for estimation of radiation hazard at manned cosmic flights

  12. Effects of solar electromagnetic radiation on the terrestrial environment

    International Nuclear Information System (INIS)

    Dickinson, R.E.

    1986-01-01

    The general intent of this essay is to discuss the effect of solar electromagnetic radiation on the terrestrial environment. Instead of giving a systematic approach considering all environment processes where solar emission is the primary energy source and all important materials which have been generated by solar driven processes, the author sketches an impression of the range of the effects of solar radiation on the environment by surveying a number of topics of particular current interest, in varying levels of detail. These include atmospheric chemistry, some aspects of the transfer of radiation within the atmosphere, global energy balance and climate feedbacks, especially those due to clouds, impacts of fossil fuel energy use, evolution of early life processes, photosynthesis and plant productivity as it relates to photosynthesis and the global carbon cycle. (Auth.)

  13. The virtual enhancements - solar proton event radiation (VESPER) model

    Science.gov (United States)

    Aminalragia-Giamini, Sigiava; Sandberg, Ingmar; Papadimitriou, Constantinos; Daglis, Ioannis A.; Jiggens, Piers

    2018-02-01

    A new probabilistic model introducing a novel paradigm for the modelling of the solar proton environment at 1 AU is presented. The virtual enhancements - solar proton event radiation model (VESPER) uses the European space agency's solar energetic particle environment modelling (SEPEM) Reference Dataset and produces virtual time-series of proton differential fluxes. In this regard it fundamentally diverges from the approach of existing SPE models that are based on probabilistic descriptions of SPE macroscopic characteristics such as peak flux and cumulative fluence. It is shown that VESPER reproduces well the dataset characteristics it uses, and further comparisons with existing models are made with respect to their results. The production of time-series as the main output of the model opens a straightforward way for the calculation of solar proton radiation effects in terms of time-series and the pairing with effects caused by trapped radiation and galactic cosmic rays.

  14. National Solar Radiation Database (NSRDB) SolarAnywhere 10 km Model Output for 1989 to 2009

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The National Solar Radiation Database (NSRDB) was produced by the National Renewable Energy Laboratory under the U.S. Department of Energy's Office of Energy...

  15. Assessment of integrated solar ultraviolet radiation by PM-355 detectors

    International Nuclear Information System (INIS)

    Abu-Jarad, F.; Al-Jarallah, M.I.; Elhadidy, M.A.; Shaahid, S.M.; Fazal-ur-Rehman

    2000-01-01

    The increase in environmental solar UV radiation due to depletion of ozone layer is a recent challenge to human health (skin cancer and eye effects) in countries having clear skies. Therefore, applying integrated, passive and inexpensive techniques to assess solar UV radiation is very much essential. Measurements of environmental solar UV radiation in Dhahran, Saudi Arabia area were carried out for a period of two months in the summer period in 1996 using two techniques in parallel namely: passive nuclear track detectors and active solar UV radiometers. Some of the nuclear track detectors were mounted in different conditions such as: under shadow band, on solar tracking mechanism following the solar rays. Others were mounted on perpendicular, tilted and horizontal surfaces in sunlight. All detectors were attached to a wooden background of the same thickness (0.5 cm) to eliminate interference of the heat effect of various support materials and have uniformity of the support materials. The assessment was carried out for different periods extending from two to nine weeks continuously. The investigated period covered the hottest months in Saudi Arabia (July and August) when the sky was clear of clouds. The results indicate linear correlation between alpha track diameters and the integrated exposure to solar UV as measured by the solar UV radiometer for all nuclear track detector positions and orientations. The highest slope has been observed for the detectors placed on solar tracking mechanism following the solar rays and the lowest from detectors oriented under the shadow band on horizontal position (measuring the diffused UV radiation only). The results show that most of the measured UV radiation (60%) were from the diffused UV radiation. The characteristics of the upper layer of the detectors are changed after chemical etching very quickly, with increase in the exposure time to UV solar radiation at certain orientation. The results encourage the use of nuclear track

  16. Assessment of integrated solar ultraviolet radiation by PM-355 detectors

    Energy Technology Data Exchange (ETDEWEB)

    Abu-Jarad, F.; Al-Jarallah, M.I.; Elhadidy, M.A.; Shaahid, S.M.; Fazal-ur-Rehman

    2000-06-01

    The increase in environmental solar UV radiation due to depletion of ozone layer is a recent challenge to human health (skin cancer and eye effects) in countries having clear skies. Therefore, applying integrated, passive and inexpensive techniques to assess solar UV radiation is very much essential. Measurements of environmental solar UV radiation in Dhahran, Saudi Arabia area were carried out for a period of two months in the summer period in 1996 using two techniques in parallel namely: passive nuclear track detectors and active solar UV radiometers. Some of the nuclear track detectors were mounted in different conditions such as: under shadow band, on solar tracking mechanism following the solar rays. Others were mounted on perpendicular, tilted and horizontal surfaces in sunlight. All detectors were attached to a wooden background of the same thickness (0.5 cm) to eliminate interference of the heat effect of various support materials and have uniformity of the support materials. The assessment was carried out for different periods extending from two to nine weeks continuously. The investigated period covered the hottest months in Saudi Arabia (July and August) when the sky was clear of clouds. The results indicate linear correlation between alpha track diameters and the integrated exposure to solar UV as measured by the solar UV radiometer for all nuclear track detector positions and orientations. The highest slope has been observed for the detectors placed on solar tracking mechanism following the solar rays and the lowest from detectors oriented under the shadow band on horizontal position (measuring the diffused UV radiation only). The results show that most of the measured UV radiation (60%) were from the diffused UV radiation. The characteristics of the upper layer of the detectors are changed after chemical etching very quickly, with increase in the exposure time to UV solar radiation at certain orientation. The results encourage the use of nuclear track

  17. Estimation of diffuse from measured global solar radiation

    International Nuclear Information System (INIS)

    Moriarty, W.W.

    1991-01-01

    A data set of quality controlled radiation observations from stations scattered throughout Australia was formed and further screened to remove residual doubtful observations. It was then divided into groups by solar elevation, and used to find average relationships for each elevation group between relative global radiation (clearness index - the measured global radiation expressed as a proportion of the radiation on a horizontal surface at the top of the atmosphere) and relative diffuse radiation. Clear-cut relationships were found, which were then fitted by polynomial expressions giving the relative diffuse radiation as a function of relative global radiation and solar elevation. When these expressions were used to estimate the diffuse radiation from the global, the results had a slightly smaller spread of errors than those from an earlier technique given by Spencer. It was found that the errors were related to cloud amount, and further relationships were developed giving the errors as functions of global radiation, solar elevation, and the fraction of sky obscured by high cloud and by opaque (low and middle level) cloud. When these relationships were used to adjust the first estimates of diffuse radiation, there was a considerable reduction in the number of large errors

  18. The Potential of Heat Collection from Solar Radiation in Asphalt Solar Collectors in Malaysia

    Science.gov (United States)

    Beddu, Salmia; Talib, Siti Hidayah Abdul; Itam, Zarina

    2016-03-01

    The implementation of asphalt solar collectors as a means of an energy source is being widely studied in recent years. Asphalt pavements are exposed to daily solar radiation, and are capable of reaching up to 70°C in temperature. The potential of harvesting energy from solar pavements as an alternative energy source in replace of non-renewable energy sources prone to depletion such as fuel is promising. In Malaysia, the sun intensity is quite high and for this reason, absorbing the heat from sun radiation, and then utilizing it in many other applications such as generating electricity could definitely be impressive. Previous researches on the different methods of studying the effect of heat absorption caused by solar radiation prove to be quite old and inaffective. More recent findings, on the otherhand, prove to be more informative. This paper focuses on determining the potential of heat collection from solar radiation in asphalt solar collectors using steel piping. The asphalt solar collector model constructed for this research was prepared in the civil engineering laboratory. The hot mixed asphalt (HMA) contains 10% bitumen mixed with 90% aggregates of the total size of asphalt. Three stainless steel pipes were embedded into the interior region of the model according to the design criteria, and then put to test. Results show that harvesting energy from asphalt solar collectors proves highly potential in Malaysia due its the hot climate.

  19. Influence of anthropogenic aerosol on solar radiation in Europe

    Energy Technology Data Exchange (ETDEWEB)

    Ten Brink, H M

    1993-12-01

    Backscatter of solar radiation by aerosol and the cooling thus induced, is the single largest uncertainty factor in assessing the climate effect of the greenhouse gases. The dominant reason for the uncertainty in the aerosol effect is its local nature. Therefore it is only via localized efforts that estimates can be improved. It is the aim of the present study to better assess the amount of solar radiation intercepted by aerosol, especially that of aerosol of anthropogenic origin in Europe. The assessment is realized along three interconnected approaches. First, empirical factors stemming from measurements in the US and used in the present estimates of the reflection of solar radiation by anthropogenic aerosol are checked for their validity in the European domain. Secondly, historical data on solar flux in Europe are related to the historic trend in aerosol loading. Finally, a sophisticated aerosol and cloud (radiation) module is developed for incorporation in a climate model. The radiation module uses aerosol characteristics as measured in the field and is validated via solar radiation measurements. The concerted investigation started in January 1993. The data obtained in the first phase of the study formed the basis for the definite detailed approach and will therefore be reported in this text. 1 fig., 9 refs.

  20. Increased radiation resistance in lithium-counterdoped silicon solar cells

    Science.gov (United States)

    Weinberg, I.; Swartz, C. K.; Mehta, S.

    1984-01-01

    Lithium-counterdoped n(+)p silicon solar cells are found to exhibit significantly increased radiation resistance to 1-MeV electron irradiation when compared to boron-doped n(+)p silicon solar cells. In addition to improved radiation resistance, considerable damage recovery by annealing is observed in the counterdoped cells at T less than or equal to 100 C. Deep level transient spectroscopy measurements are used to identify the defect whose removal results in the low-temperature aneal. It is suggested that the increased radiation resistance of the counterdoped cells is primarily due to interaction of the lithium with interstitial oxygen.

  1. Spatial solar radiation distribution analysis in afforestation at horqin desert, China

    International Nuclear Information System (INIS)

    Hao, A.; Haraguchi, T.; Nakano, Y.; Amaya, T.

    2007-01-01

    Forestation is one of the effective ways to prevent the desertification. This study was conducted to evaluate the effects of big project of forestation going on at Naimanki, Horqin Desert in China. First, a simulation model was proposed to estimate solar radiation environment in the poplars forest. Second, using fisheye-photographs taken at several points on the soil surface between tree rows, gap space of the canopy was calculated with applying the Gap Light Analyzer (GLA). Third, the gap space data were used for simulating direct radiation, diffused radiation and scattered radiation at different points on the soil surface. Fourth, the accuracy of simulation model was checked by comparing the estimated solar radiations at four points on the soil surface with the observation. The estimated values showed good agreement with the observation. Once the fisheye-photographs were taken at any points on the soil surface, daily fluctuations of solar radiation in the forestation can be calculated. Solar radiation acts main role on energy balance, heat balance and water balance phenomena in the forestation. The proposed method would be effectively used for evaluating the environmental modification brought by the forestation in the desert

  2. Seasonal and interannual variability of solar radiation at Spirit, Opportunity and Curiosity landing sites

    Energy Technology Data Exchange (ETDEWEB)

    Vicente-Retortillo, A.; Lemmon, M.T.; Martinez, G.; Valero, F.; Vazquez, L.; Martin, M.L.

    2016-07-01

    In this article we characterize the radiative environment at the landing sites of NASA's Mars Exploration Rover (MER) and Mars Science Laboratory (MSL) missions. We use opacity values obtained at the surface from direct imaging of the Sun and our radiative transfer model COMIMART to analyze the seasonal and interannual variability of the daily irradiation at the MER and MSL landing sites. In addition, we analyze the behavior of the direct and diffuse components of the solar radiation at these landing sites. (Author)

  3. Radiator selection for Space Station Solar Dynamic Power Systems

    Science.gov (United States)

    Fleming, Mike; Hoehn, Frank

    A study was conducted to define the best radiator for heat rejection of the Space Station Solar Dynamic Power System. Included in the study were radiators for both the Organic Rankine Cycle and Closed Brayton Cycle heat engines. A number of potential approaches were considered for the Organic Rankine Cycle and a constructable radiator was chosen. Detailed optimizations of this concept were conducted resulting in a baseline for inclusion into the ORC Preliminary Design. A number of approaches were also considered for the CBC radiator. For this application a deployed pumped liquid radiator was selected which was also refined resulting in a baseline for the CBC preliminary design. This paper reports the results and methodology of these studies and describes the preliminary designs of the Space Station Solar Dynamic Power System radiators for both of the candidate heat engine cycles.

  4. Flight attendant radiation dose from solar particle events.

    Science.gov (United States)

    Anderson, Jeri L; Mertens, Christopher J; Grajewski, Barbara; Luo, Lian; Tseng, Chih-Yu; Cassinelli, Rick T

    2014-08-01

    Research has suggested that work as a flight attendant may be related to increased risk for reproductive health effects. Air cabin exposures that may influence reproductive health include radiation dose from galactic cosmic radiation and solar particle events. This paper describes the assessment of radiation dose accrued during solar particle events as part of a reproductive health study of flight attendants. Solar storm data were obtained from the National Oceanic and Atmospheric Administration Space Weather Prediction Center list of solar proton events affecting the Earth environment to ascertain storms relevant to the two study periods (1992-1996 and 1999-2001). Radiation dose from exposure to solar energetic particles was estimated using the NAIRAS model in conjunction with galactic cosmic radiation dose calculated using the CARI-6P computer program. Seven solar particle events were determined to have potential for significant radiation exposure, two in the first study period and five in the second study period, and over-lapped with 24,807 flight segments. Absorbed (and effective) flight segment doses averaged 6.5 μGy (18 μSv) and 3.1 μGy (8.3 μSv) for the first and second study periods, respectively. Maximum doses were as high as 440 μGy (1.2 mSv) and 20 flight segments had doses greater than 190 μGy (0.5 mSv). During solar particle events, a pregnant flight attendant could potentially exceed the equivalent dose limit to the conceptus of 0.5 mSv in a month recommended by the National Council on Radiation Protection and Measurements.

  5. Solar ultraviolet radiation effects on biological systems

    International Nuclear Information System (INIS)

    Diffey, B.L.

    1991-01-01

    This extensive review discusses the topic under the following headings: ultraviolet climatology, molecular and cellular ultraviolet photobiology (absorption, photoproducts, repair), effects of solar UVR on aquatic life (phyto and zooplankton), plants and humans. The section on human effects includes tanning, photo-aging, non-melanoma and melanoma skin cancers and the effects of solar UVR on the eye. (UK)

  6. Solar ultraviolet radiation effects on biological systems

    Energy Technology Data Exchange (ETDEWEB)

    Diffey, B.L. (Dryburn Hospital, Durham (UK). Regional Medical Physics Dept.)

    1991-03-01

    This extensive review discusses the topic under the following headings: ultraviolet climatology, molecular and cellular ultraviolet photobiology (absorption, photoproducts, repair), effects of solar UVR on aquatic life (phyto and zooplankton), plants and humans. The section on human effects includes tanning, photo-aging, non-melanoma and melanoma skin cancers and the effects of solar UVR on the eye. (UK).

  7. Validation of modelling the radiation exposure due to solar particle events at aircraft altitudes

    International Nuclear Information System (INIS)

    Beck, P.; Bartlett, D. T.; Bilski, P.; Dyer, C.; Flueckiger, E.; Fuller, N.; Lantos, P.; Reitz, G.; Ruehm, W.; Spurny, F.; Taylor, G.; Trompier, F.; Wissmann, F.

    2008-01-01

    Dose assessment procedures for cosmic radiation exposure of aircraft crew have been introduced in most European countries in accordance with the corresponding European directive and national regulations. However, the radiation exposure due to solar particle events is still a matter of scientific research. Here we describe the European research project CONRAD, WP6, Subgroup-B, about the current status of available solar storm measurements and existing models for dose estimation at flight altitudes during solar particle events leading to ground level enhancement (GLE). Three models for the numerical dose estimation during GLEs are discussed. Some of the models agree with limited experimental data reasonably well. Analysis of GLEs during geomagnetically disturbed conditions is still complex and time consuming. Currently available solar particle event models can disagree with each other by an order of magnitude. Further research and verification by on-board measurements is still needed. (authors)

  8. Satellite-based climate data records of surface solar radiation from the CM SAF

    Science.gov (United States)

    Trentmann, Jörg; Cremer, Roswitha; Kothe, Steffen; Müller, Richard; Pfeifroth, Uwe

    2017-04-01

    The incoming surface solar radiation has been defined as an essential climate variable by GCOS. Long term monitoring of this part of the earth's energy budget is required to gain insights on the state and variability of the climate system. In addition, climate data sets of surface solar radiation have received increased attention over the recent years as an important source of information for solar energy assessments, for crop modeling, and for the validation of climate and weather models. The EUMETSAT Satellite Application Facility on Climate Monitoring (CM SAF) is deriving climate data records (CDRs) from geostationary and polar-orbiting satellite instruments. Within the CM SAF these CDRs are accompanied by operational data at a short time latency to be used for climate monitoring. All data from the CM SAF is freely available via www.cmsaf.eu. Here we present the regional and the global climate data records of surface solar radiation from the CM SAF. The regional climate data record SARAH (Surface Solar Radiation Dataset - Heliosat, doi: 10.5676/EUM_SAF_CM/SARAH/V002) is based on observations from the series of Meteosat satellites. SARAH provides 30-min, daily- and monthly-averaged data of the effective cloud albedo, the solar irradiance (incl. spectral information), the direct solar radiation (horizontal and normal), and the sunshine duration from 1983 to 2015 for the full view of the Meteosat satellite (i.e, Europe, Africa, parts of South America, and the Atlantic ocean). The data sets are generated with a high spatial resolution of 0.05° allowing for detailed regional studies. The global climate data record CLARA (CM SAF Clouds, Albedo and Radiation dataset from AVHRR data, doi: 10.5676/EUM_SAF_CM/CLARA_AVHRR/V002) is based on observations from the series of AVHRR satellite instruments. CLARA provides daily- and monthly-averaged global data of the solar irradiance (SIS) from 1982 to 2015 with a spatial resolution of 0.25°. In addition to the solar surface

  9. Solar wind radiation damage in lunar dust grains and the characteristics of the ancient solar wind

    International Nuclear Information System (INIS)

    Borg, J.; Chaumont, J.

    1980-01-01

    Current understanding of the exposure history of lunar dust grains to the ancient solar wind is reviewed, the work being based mostly on a Monte Carlo statistical code, describing the 'gardening' effects of the meteorite bombardment in the lunar regolith, and on analytical models, yielding the lifetimes of the grains against various types of destruction processes. Families of lunar dust grains are identified, and evidence is presented showing that lunar dust grains were not partially shielded from solar wind ions. Results of solar wind simulation experiments are used to interpret the thickness distribution of the amorphous coatings of solar wind radiation-damaged material observed on 1-micron lunar dust grains. It is argued that such distributions reflect the speed distribution of the ancient solar wind as averaged over periods of approximately 5000 years in duration, and that the ancient solar wind is less energetic than the present day solar wind

  10. A comparative study of direct and indirect solar drying of mango ...

    African Journals Online (AJOL)

    A comparative study of direct and indirect solar drying of mango. ... Thus, indirect solar dryer was found to be suitable for industrial or semi industrial mango drying, whereas direct solar dryer was appropriate to a family ... HOW TO USE AJOL.

  11. Interplanetary Radiation and Internal Charging Environment Models for Solar Sails

    Science.gov (United States)

    Minow, Joseph I.; Altstatt, Richard L.; NeegaardParker, Linda

    2005-01-01

    A Solar Sail Radiation Environment (SSRE) model has been developed for defining charged particle environments over an energy range from 0.01 keV to 1 MeV for hydrogen ions, helium ions, and electrons. The SSRE model provides the free field charged particle environment required for characterizing energy deposition per unit mass, charge deposition, and dose rate dependent conductivity processes required to evaluate radiation dose and internal (bulk) charging processes in the solar sail membrane in interplanetary space. Solar wind and energetic particle measurements from instruments aboard the Ulysses spacecraft in a solar, near-polar orbit provide the particle data over a range of heliospheric latitudes used to derive the environment that can be used for radiation and charging environments for both high inclination 0.5 AU Solar Polar Imager mission and the 1.0 AU L1 solar missions. This paper describes the techniques used to model comprehensive electron, proton, and helium spectra over the range of particle energies of significance to energy and charge deposition in thin (less than 25 micrometers) solar sail materials.

  12. Radiation resistance of solar cells for space application, 1

    International Nuclear Information System (INIS)

    Mitsui, Hiroshi; Tanaka, Ryuichi; Sunaga, Hiromi

    1989-07-01

    A 50-μm thick ultrathin silicon solar cell and a 280-μm thick high performance AlGaAs/GaAs solar cell with high radiation resistance have been recently developed by National Space Development Agency of Japan (NASDA). In order to study the radiation resistance of these cells, a joint research was carried out between Japan Atomic Energy Research Institute (JAERI) and NASDA from 1984 through 1987. In this research, the irradiation method of electron beams, the effects of the irradiation conditions on the deterioration of solar cells by electron beams, and the annealing effects of the radiation damage in solar cells were investigated. This paper is the first one of a series of reports of the joint research. In this paper, the space radiation environment which artificial satellites will encounter, the solar cells used, and the experimental methods are described. In addition to these, the results of the study on the irradiation procedure of electron beams are reported. In the study of the irradiation method of electron beams, three methods, that is, the fixed irradiation method, the moving irradiation method, and the spot irradiation method were examined. In the fixed irradiation method and moving one, stationary solar cells and solar cells moving by conveyer were irradiated by scanning electron beams, respectively. On the other hand, in the spot irradiation method, stationary solar cells were irradiated by non-scanning steady electron beams. It was concluded that the fixed irradiation method was the most proper method. In addition to this, in this study, some pieces of information were obtained with respect to the changes in the electrical characteristics of solar cells caused by the irradiation of electron beams. (author) 52 refs

  13. Performance evaluation and solar radiation capture of optimally inclined box type solar cooker with parallelepiped cooking vessel design

    International Nuclear Information System (INIS)

    Sethi, V.P.; Pal, D.S.; Sumathy, K.

    2014-01-01

    Highlights: • Optimally inclined solar cooker is presented for efficient cooking. • A new parallelepiped shaped cooking vessel for higher solar radiation capture is presented. • Optimum tilt angles of the boosted mirror are computed for maximization of reflected components. • Solar radiation capture ratios show the better cooking performance of inclined cooker. • Standard performance parameters establish the better cooking performance of inclined cooker. - Abstract: An optimally inclined box type solar cooker with single booster mirror is presented along with design and development of a novel parallelepiped shaped cooking vessel design for efficient cooking especially in winter conditions. The main feature of new parallelepiped shaped design is its longer inclined south wall (facing the sun) and a trapezoidal cavity on the vessel lid for greater heat transfer to the food material. The ends of the vessel towards east and west direction are minimized. The cooking performance parameters of proposed inclined cooker coupled with new vessel design were compared with horizontally placed identical cooker of same material and dimensions coupled with conventional cylindrical vessel design during winter month (January) of the year 2010 at Ludhiana climate (30°N 77°E), India. Results showed that the first and the second figures of merit (F 1 and F 2 ) for inclined cooker were 0.16 and 0.54 as compared to 0.14 and 0.43 for horizontally placed cooker. Time taken to boil the water τ boil and standard cooking power P n was 37% less and 40% more respectively in parallelepiped shaped cooking vessel of inclined cooker as compared to conventional cylindrical vessel of horizontally placed cooker. A mathematical model is developed to compute the total solar radiation availability on the absorber plate of inclined as well as horizontal cooker which establishes the better cooking performance of the inclined cooker due to greater width of sun rays intercepting the absorber

  14. Atmospheric turbidity parameters affecting the incident solar solar radiation for two different areas in (Eg))

    International Nuclear Information System (INIS)

    Tadros, M.T.Y.; Mosalam, M.A.; El-metwally, M.

    1999-01-01

    Atmospheric turbidity parameters such as Linke turbidity (L-0) and true Angstrom parameters (Bita o , Alpha 0 ) have been determined from the measurements of direct solar radiation for entire spectrum and for specified spectral bands during one year starting from june 1992 to may 1993. Comparison between the industrial area in Helwan (south Cairo) with that of the agricultural area in Mansoura, in (Eg), was done. Analysis of data revealed that the atmospheric turbidity parameters (L Beta) in Helwan is higher than that in Mansoura, except for hot wet months. The increase of L in Mansoura, in summer, is due to the increase of water vapor content. The wavelength exponent Alpha shows that the size the size of particles in Helwan is larger than that in Mansoura

  15. Effect of solar radiation on drying house performance

    International Nuclear Information System (INIS)

    Rachmat, R.

    2000-01-01

    Solar drying is one of thermal utilization where radiation energy can be utilized efficiently. Solar drying of all sorts of agricultural products have been thoroughly studied and reported in literature, but brown rice drying system has not yet done as many as other products. The aim of the present study is to investigate the effect of solar radiation on drying house performance and brown rice drying characteristics. A construction of drying house is made from FRP sheets with 30 deg. of root slope faces southern part and inside the drying house is installed a flat bed dryer. The site of construction has 136 deg. 31.4'E in longitude and 34 deg. 43.8N in latitude with 3 m in elevation from sea level. The investigated parameters are global solar radiation, absorbed and net radiation and brown rice drying characteristics. The results showed that in unload condition, the air temperature inside drying house was higher (10 deg. C - 12 deg. C) than ambient air when there was not collector and temperature rise become higher (16 deg. C) when there was a black FRP collector inside drying house. The effect of solar radiation on temperature rise has the trend as a linear function. The heat collection efficiency of drying house with black FRP collector was two times higher (36.9 percent) than that without collector (16.3 percent). These phenomena exhibited significant result of collector utilization to the advantageous condition for a drying purpose [in

  16. Prediction of hourly solar radiation with multi-model framework

    International Nuclear Information System (INIS)

    Wu, Ji; Chan, Chee Keong

    2013-01-01

    Highlights: • A novel approach to predict solar radiation through the use of clustering paradigms. • Development of prediction models based on the intrinsic pattern observed in each cluster. • Prediction based on proper clustering and selection of model on current time provides better results than other methods. • Experiments were conducted on actual solar radiation data obtained from a weather station in Singapore. - Abstract: In this paper, a novel multi-model prediction framework for prediction of solar radiation is proposed. The framework started with the assumption that there are several patterns embedded in the solar radiation series. To extract the underlying pattern, the solar radiation series is first segmented into smaller subsequences, and the subsequences are further grouped into different clusters. For each cluster, an appropriate prediction model is trained. Hence a procedure for pattern identification is developed to identify the proper pattern that fits the current period. Based on this pattern, the corresponding prediction model is applied to obtain the prediction value. The prediction result of the proposed framework is then compared to other techniques. It is shown that the proposed framework provides superior performance as compared to others

  17. SRADLIB: A C Library for Solar Radiation Modelling

    Energy Technology Data Exchange (ETDEWEB)

    Balenzategui, J. L. [Ciemat. Madrid (Spain)

    2000-07-01

    This document shows the result of an exhaustive study about the theoretical and numerical models available in the literature about solar radiation modelling. The purpose of this study is to develop or adapt mathematical models describing the solar radiation specifically for Spain locations as well as to create computer tools able to support the labour of researchers or engineers needing solar radiation data to solve or improve the technical or energetic performance of solar systems. As results of this study and revision, a C library (SRADLIB) is presented as a key for the compilation of the mathematical models from different authors, for the comparison among the different approaches and for its application in computer programs. Different topics related to solar radiation and its modelling are first discussed, including the assumptions and conventions adopted and describing the most accepted and used current state-of-the-art models. some typical problems in the numerical calculation of radiation values are also posed with the proposed solution. The document includes next a complete reference of the developed functions, with many examples of application and calculus. (Author) 24 refs.

  18. SRADLIB: A C Library for Solar Radiation Modelling

    International Nuclear Information System (INIS)

    Balenzategui, J. L.

    1999-01-01

    This document shows the result of an exhaustive study about the theoretical and numerical models available in the literature about solar radiation modelling. The purpose of this study is to develop or adapt mathematical models describing the solar radiation specifically for Spain locations as well as to create computer tools able to support the labour of researchers or engineers needing solar radiation data to solve or improve the technical or energetic performance of solar systems. As result of this study and revision, a C library (SRADLIB) is presented as a key tool for the compilation of the mathematical models from different authors, for the comparison among the different approaches and for its application in computer programs. Different topics related to solar radiation and its modelling are first discussed, including the assumptions and conventions adopted and describing the most accepted and used current state-of-the-art models. Some typical problems in the numerical calculation of radiation values are also posed with the proposed solution. The document includes next a complete reference of the developed functions, with many examples of application and calculus. (Author) 24 refs

  19. Ascertaining directionality information from incident nuclear radiation

    Energy Technology Data Exchange (ETDEWEB)

    Archambault, Brian C. [Purdue University (United States); Lapinskas, Joseph R. [QSA Global, Inc. (United States); Wang Jing; Webster, Jeffrey A. [Purdue University (United States); McDeavitt, Sean [Texas A and M University (United States); Taleyarkhan, Rusi P., E-mail: rusi@purdue.edu [Purdue University (United States)

    2011-10-15

    Highlights: > Use of tensioned metastable fluids for detection of fast neutron radiation. > Monitored neutrons with 100% gamma photon blindness capability. > Monitored direction of incoming neutron radiation from special nuclear material emissions. > Ascertained directionality of neutron source to within 30 deg. and with 80% confidence with 2000 detection events at rate of 30-40 per second. > Conducted successful blind test for determining source of neutrons from a hidden neutron emitting source. > Compared results with MCNP5-COMSOL based multi-physics model. - Abstract: Unprecedented capabilities for the detection of nuclear particles via tailored resonant acoustic systems such as the acoustic tensioned metastable fluid detection (ATMFD) systems were assessed for determining directionality of incoming fast neutrons. This paper presents advancements that expand on these accomplishments, thereby increasing the accuracy and precision of ascertaining directionality information utilizing enhanced signal processing-cum-signal analysis, refined computational algorithms, and on demand enlargement of the detector sensitive volume. Advances in the development of ATMFD systems were accomplished utilizing a combination of experimentation and theoretical modeling. Modeling methodologies include Monte-Carlo based nuclear particle transport using MCNP5 and multi-physics based assessments accounting for acoustic, structural, and electromagnetic coupling of the ATMFD system via COMSOL's multi-physics simulation platform. Benchmarking and qualification studies have been conducted with a 1 Ci Pu-Be neutron-gamma source. These results show that the specific ATMFD system used for this study can enable detection of directionality of incoming fast neutrons from the neutron source to within 30{sup o} with 80% confidence; this required {approx}2000 detection events which could be collected within {approx}50 s at a detection rate of {approx}30-40 per second. Blind testing was

  20. Ascertaining directionality information from incident nuclear radiation

    International Nuclear Information System (INIS)

    Archambault, Brian C.; Lapinskas, Joseph R.; Wang Jing; Webster, Jeffrey A.; McDeavitt, Sean; Taleyarkhan, Rusi P.

    2011-01-01

    Highlights: → Use of tensioned metastable fluids for detection of fast neutron radiation. → Monitored neutrons with 100% gamma photon blindness capability. → Monitored direction of incoming neutron radiation from special nuclear material emissions. → Ascertained directionality of neutron source to within 30 deg. and with 80% confidence with 2000 detection events at rate of 30-40 per second. → Conducted successful blind test for determining source of neutrons from a hidden neutron emitting source. → Compared results with MCNP5-COMSOL based multi-physics model. - Abstract: Unprecedented capabilities for the detection of nuclear particles via tailored resonant acoustic systems such as the acoustic tensioned metastable fluid detection (ATMFD) systems were assessed for determining directionality of incoming fast neutrons. This paper presents advancements that expand on these accomplishments, thereby increasing the accuracy and precision of ascertaining directionality information utilizing enhanced signal processing-cum-signal analysis, refined computational algorithms, and on demand enlargement of the detector sensitive volume. Advances in the development of ATMFD systems were accomplished utilizing a combination of experimentation and theoretical modeling. Modeling methodologies include Monte-Carlo based nuclear particle transport using MCNP5 and multi-physics based assessments accounting for acoustic, structural, and electromagnetic coupling of the ATMFD system via COMSOL's multi-physics simulation platform. Benchmarking and qualification studies have been conducted with a 1 Ci Pu-Be neutron-gamma source. These results show that the specific ATMFD system used for this study can enable detection of directionality of incoming fast neutrons from the neutron source to within 30 o with 80% confidence; this required ∼2000 detection events which could be collected within ∼50 s at a detection rate of ∼30-40 per second. Blind testing was successfully

  1. Workshop on past and present solar radiation: the record in meteoritic and lunar regolith material

    International Nuclear Information System (INIS)

    Pepin, R.O.; Mckay, D.S.

    1986-01-01

    The principal question addressed in the workshop was the extent to which asteroidal and lunar regoliths have collected and preserved, in meteoritic regolith breccias and in lunar soils and regolith breccias, a record of the flux, energy, and compositional history of the solar wind and solar flares. Six central discussion topics were identified. They are: (1)Trapped solar wind and flare gases, tracks, and micrometeorite pits in regolith components; (2)Comparison between lunar regolith breccias, meteoritic regolith breccias, and the lunar soil; (3)The special role of regolith breccias and the challenge of dating their times of compaction; (4)Implications of the data for the flux and compositional history of solar particle emission, composition, and physical mechanisms in the solar source regions, and the composition of the early nebula; (5)How and to what extent have records of incident radiation been altered in various types of grains; (6) Future research directions

  2. Short-range solar radiation forecasts over Sweden

    Directory of Open Access Journals (Sweden)

    T. Landelius

    2018-04-01

    Full Text Available In this article the performance for short-range solar radiation forecasts by the global deterministic and ensemble models from the European Centre for Medium-Range Weather Forecasts (ECMWF is compared with an ensemble of the regional mesoscale model HARMONIE-AROME used by the national meteorological services in Sweden, Norway and Finland. Note however that only the control members and the ensemble means are included in the comparison. The models resolution differs considerably with 18 km for the ECMWF ensemble, 9 km for the ECMWF deterministic model, and 2.5 km for the HARMONIE-AROME ensemble.The models share the same radiation code. It turns out that they all underestimate systematically the Direct Normal Irradiance (DNI for clear-sky conditions. Except for this shortcoming, the HARMONIE-AROME ensemble model shows the best agreement with the distribution of observed Global Horizontal Irradiance (GHI and DNI values. During mid-day the HARMONIE-AROME ensemble mean performs best. The control member of the HARMONIE-AROME ensemble also scores better than the global deterministic ECMWF model. This is an interesting result since mesoscale models have so far not shown good results when compared to the ECMWF models.Three days with clear, mixed and cloudy skies are used to illustrate the possible added value of a probabilistic forecast. It is shown that in these cases the mesoscale ensemble could provide decision support to a grid operator in terms of forecasts of both the amount of solar power and its probabilities.

  3. Solar Radiation Received by Slopes Using COMS Imagery, a Physically Based Radiation Model, and GLOBE

    Directory of Open Access Journals (Sweden)

    Jong-Min Yeom

    2016-01-01

    Full Text Available This study mapped the solar radiation received by slopes for all of Korea, including areas that are not measured by ground station measurements, through using satellites and topographical data. When estimating insolation with satellite, we used a physical model to measure the amount of hourly based solar surface insolation. Furthermore, we also considered the effects of topography using the Global Land One-Kilometer Base Elevation (GLOBE digital elevation model (DEM for the actual amount of incident solar radiation according to solar geometry. The surface insolation mapping, by integrating a physical model with the Communication, Ocean, and Meteorological Satellite (COMS Meteorological Imager (MI image, was performed through a comparative analysis with ground-based observation data (pyranometer. Original and topographically corrected solar radiation maps were created and their characteristics analyzed. Both the original and the topographically corrected solar energy resource maps captured the temporal variations in atmospheric conditions, such as the movement of seasonal rain fronts during summer. In contrast, although the original solar radiation map had a low insolation value over mountain areas with a high rate of cloudiness, the topographically corrected solar radiation map provided a better description of the actual surface geometric characteristics.

  4. A link between solar events and congenital malformations: Is ionizing radiation enough to explain it?

    Science.gov (United States)

    Overholt, Andrew C.; Melott, Adrian L.; Atri, Dimitra

    2015-03-01

    Cosmic rays are known to cause biological effects directly and through ionizing radiation produced by their secondaries. These effects have been detected in airline crews and other specific cases where members of the population are exposed to above average secondary fluxes. Recent work has found a correlation between solar particle events and congenital malformations. In this work we use the results of computational simulations to approximate the ionizing radiation from such events as well as longer-term increases in cosmic ray flux. We find that the amounts of ionizing radiation produced by these events are insufficient to produce congenital malformations under the current paradigm regarding muon ionizing radiation. We believe that further work is needed to determine the correct ionizing radiation contribution of cosmogenic muons. We suggest that more extensive measurements of muon radiation effects may show a larger contribution to ionizing radiation dose than currently assumed.

  5. Solar radiation pressure and deviations from Keplerian orbits

    Energy Technology Data Exchange (ETDEWEB)

    Kezerashvili, Roman Ya. [Physics Department, New York City College of Technology, the City University of New York, Brooklyn, NY 11201 (United States); Vazquez-Poritz, Justin F. [Physics Department, New York City College of Technology, City University of New York, Brooklyn, NY 11201 (United States)], E-mail: jporitz@gmail.com

    2009-05-04

    Newtonian gravity and general relativity give exactly the same expression for the period of an object in circular orbit around a static central mass. However, when the effects of the curvature of spacetime and solar radiation pressure are considered simultaneously for a solar sail propelled satellite, there is a deviation from Kepler's third law. It is shown that solar radiation pressure affects the period of this satellite in two ways: by effectively decreasing the solar mass, thereby increasing the period, and by enhancing the effects of other phenomena, potentially rendering some of them detectable. In particular, we consider deviations from Keplerian orbits due to spacetime curvature, frame dragging from the rotation of the sun, the oblateness of the sun, a possible net electric charge of the sun, and a very small positive cosmological constant.

  6. Solar panel thermal cycling testing by solar simulation and infrared radiation methods

    Science.gov (United States)

    Nuss, H. E.

    1980-01-01

    For the solar panels of the European Space Agency (ESA) satellites OTS/MAROTS and ECS/MARECS the thermal cycling tests were performed by using solar simulation methods. The performance data of two different solar simulators used and the thermal test results are described. The solar simulation thermal cycling tests for the ECS/MARECS solar panels were carried out with the aid of a rotatable multipanel test rig by which simultaneous testing of three solar panels was possible. As an alternative thermal test method, the capability of an infrared radiation method was studied and infrared simulation tests for the ultralight panel and the INTELSAT 5 solar panels were performed. The setup and the characteristics of the infrared radiation unit using a quartz lamp array of approx. 15 sq and LN2-cooled shutter and the thermal test results are presented. The irradiation uniformity, the solar panel temperature distribution, temperature changing rates for both test methods are compared. Results indicate the infrared simulation is an effective solar panel thermal testing method.

  7. Global Solar Radiation in Spain from Satellite Images

    International Nuclear Information System (INIS)

    Ramirez, L.; Mora, L.; Sidrach de Cardona, M.; Navarro, A. A.; Varela, M.; Cruz, M. de la

    2003-01-01

    In the context of the present work a series of algorithms of calculation of the solar radiation from satellite images has been developed. These models, have been applied to three years of images of the Meteosat satellite and the results of the treatment have been extrapolated to long term. For the development of the models of solar radiation registered in ground stations have been used, corresponding all of them to localities of peninsular Spain and the Balearic ones. The maximum periods of data available have been used, supposing in most of the cases periods of between 6 and 9 years. From the results has a year type of images of global solar radiation on horizontal surface. The original resolution of the image of 7x7 km in the study latitudes, has been reevaluated to 5x5 km. This supposes to have a value of the typical radiation for every day of the year, each 5x5 km in the study territory. This information, supposes an important advance as far as the knowledge of the space distribution of the radiation solar, impossible to reach about alternative methods. Doubtlessly, the precision of the provided values is not comparable with pyrano metric measures in a concrete locality, but it provides a very valid indicator in places in which it is not had previous information. In addition to the radiation maps, tables of the global solar radiation have been prepared on different inclinations, from the global radiation on horizontal surface calculated for every day of the year and in each pixel of the image. (Author) 24 refs

  8. Effects of increased solar ultraviolet radiation on terrestrial plants

    International Nuclear Information System (INIS)

    Caldwell, M.M.; Teramura, A.H.; Tevini, M.; Bornman, J.F.; Björn, L.O.; Kulandaivelu, G.

    1995-01-01

    Physiological and developmental processes of plants are affected by UV-B radiation, even by the amount of UV-B in present-day sunlight. Plants also have several mechanisms to ameliorate or repair these effects and may acclimate to a certain extent to increased levels of UV-B. Nevertheless, plant growth can be directly affected by UV-B radiation. Response to UV-B also varies considerably among species and also cultivars of the same species. In agriculture, this may necessitate using more UV-B-tolerant cultivars and breeding new ones. In forests and grasslands, this will likely result in changes in species composition; therefore there are implications for the biodiversity in different ecosystems. Indirect changes caused by UV-B-such as changes in plant form, biomass allocation to parts of the plant, timing of developmental phases and secondary metabolism-may be equally, or sometimes more important than damaging effects of UV-B. These changes can have important implications for plant competitive balance, herbivory, plant pathogens, and biogeochemical cycles. These ecosystem-level effects can be anticipated, but not easily predicted or evaluated. Research at the ecosystem level for solar UV-B is barely beginning. Other factors, including those involved in climate change such as increasing CO2, also interact with UV-B. Such reactions are not easily predicted, but are of obvious importance in both agriculture and in nonagricultural ecosystems

  9. Atmospheric Renewable Energy Research, Volume 5 (Solar Radiation Flux Model)

    Science.gov (United States)

    2017-09-01

    sources, namely photovoltaic (PV) panels, to roughly determine the energy producing potential of an installation’s solar array. The implicit...power resources assembled as a single system (generator, storage, distribution and load), with the ability to run independently as an “island” and/or...atmospheric layers that will act on the solar radiation as it traverses strata. These terms are a function of cloud type, size , and density. To create a

  10. Curve fitting methods for solar radiation data modeling

    Energy Technology Data Exchange (ETDEWEB)

    Karim, Samsul Ariffin Abdul, E-mail: samsul-ariffin@petronas.com.my, E-mail: balbir@petronas.com.my; Singh, Balbir Singh Mahinder, E-mail: samsul-ariffin@petronas.com.my, E-mail: balbir@petronas.com.my [Department of Fundamental and Applied Sciences, Faculty of Sciences and Information Technology, Universiti Teknologi PETRONAS, Bandar Seri Iskandar, 31750 Tronoh, Perak Darul Ridzuan (Malaysia)

    2014-10-24

    This paper studies the use of several type of curve fitting method to smooth the global solar radiation data. After the data have been fitted by using curve fitting method, the mathematical model of global solar radiation will be developed. The error measurement was calculated by using goodness-fit statistics such as root mean square error (RMSE) and the value of R{sup 2}. The best fitting methods will be used as a starting point for the construction of mathematical modeling of solar radiation received in Universiti Teknologi PETRONAS (UTP) Malaysia. Numerical results indicated that Gaussian fitting and sine fitting (both with two terms) gives better results as compare with the other fitting methods.

  11. Curve fitting methods for solar radiation data modeling

    Science.gov (United States)

    Karim, Samsul Ariffin Abdul; Singh, Balbir Singh Mahinder

    2014-10-01

    This paper studies the use of several type of curve fitting method to smooth the global solar radiation data. After the data have been fitted by using curve fitting method, the mathematical model of global solar radiation will be developed. The error measurement was calculated by using goodness-fit statistics such as root mean square error (RMSE) and the value of R2. The best fitting methods will be used as a starting point for the construction of mathematical modeling of solar radiation received in Universiti Teknologi PETRONAS (UTP) Malaysia. Numerical results indicated that Gaussian fitting and sine fitting (both with two terms) gives better results as compare with the other fitting methods.

  12. Curve fitting methods for solar radiation data modeling

    International Nuclear Information System (INIS)

    Karim, Samsul Ariffin Abdul; Singh, Balbir Singh Mahinder

    2014-01-01

    This paper studies the use of several type of curve fitting method to smooth the global solar radiation data. After the data have been fitted by using curve fitting method, the mathematical model of global solar radiation will be developed. The error measurement was calculated by using goodness-fit statistics such as root mean square error (RMSE) and the value of R 2 . The best fitting methods will be used as a starting point for the construction of mathematical modeling of solar radiation received in Universiti Teknologi PETRONAS (UTP) Malaysia. Numerical results indicated that Gaussian fitting and sine fitting (both with two terms) gives better results as compare with the other fitting methods

  13. Performance Evaluation of a Nanofluid-Based Direct Absorption Solar Collector with Parabolic Trough Concentrator

    Directory of Open Access Journals (Sweden)

    Guoying Xu

    2015-12-01

    Full Text Available Application of solar collectors for hot water supply, space heating, and cooling plays a significant role in reducing building energy consumption. For conventional solar collectors, solar radiation is absorbed by spectral selective coating on the collectors’ tube/plate wall. The poor durability of the coating can lead to an increased manufacturing cost and unreliability for a solar collector operated at a higher temperature. Therefore, a novel nanofluid-based direct absorption solar collector (NDASC employing uncoated collector tubes has been proposed, and its operating characteristics for medium-temperature solar collection were theoretically and experimentally studied in this paper. CuO/oil nanofluid was prepared and used as working fluid of the NDASC. The heat-transfer mechanism of the NDASC with parabolic trough concentrator was theoretically evaluated and compared with a conventional indirect absorption solar collector (IASC. The theoretical analysis results suggested that the fluid’s temperature distribution in the NDASC was much more uniform than that in the IASC, and an enhanced collection efficiency could be achieved for the NDASC operated within a preferred working temperature range. To demonstrate the feasibility of the proposed NDASC, experimental performances of an NDASC and an IASC with the same parabolic trough concentrator were furthermore evaluated and comparatively discussed.

  14. Performance Evaluation of a Nanofluid-Based Direct Absorption Solar Collector with Parabolic Trough Concentrator

    Science.gov (United States)

    Xu, Guoying; Chen, Wei; Deng, Shiming; Zhang, Xiaosong; Zhao, Sainan

    2015-01-01

    Application of solar collectors for hot water supply, space heating, and cooling plays a significant role in reducing building energy consumption. For conventional solar collectors, solar radiation is absorbed by spectral selective coating on the collectors’ tube/plate wall. The poor durability of the coating can lead to an increased manufacturing cost and unreliability for a solar collector operated at a higher temperature. Therefore, a novel nanofluid-based direct absorption solar collector (NDASC) employing uncoated collector tubes has been proposed, and its operating characteristics for medium-temperature solar collection were theoretically and experimentally studied in this paper. CuO/oil nanofluid was prepared and used as working fluid of the NDASC. The heat-transfer mechanism of the NDASC with parabolic trough concentrator was theoretically evaluated and compared with a conventional indirect absorption solar collector (IASC). The theoretical analysis results suggested that the fluid’s temperature distribution in the NDASC was much more uniform than that in the IASC, and an enhanced collection efficiency could be achieved for the NDASC operated within a preferred working temperature range. To demonstrate the feasibility of the proposed NDASC, experimental performances of an NDASC and an IASC with the same parabolic trough concentrator were furthermore evaluated and comparatively discussed. PMID:28347112

  15. Analysis of direct to diffuse partitioning of global solar irradiance at the radiometric station in Badajoz (Spain)

    Science.gov (United States)

    Sanchez, G.; Cancillo, M. L.; Serrano, A.

    2010-09-01

    This study is aimed at the analysis of the partitioning of global solar irradiance into its direct and diffuse components at the radiometric station in Badajoz (Spain). The detailed knowledge of the solar radiation field is of increasing interest in Southern Europe due to its use as renewable energy. In particular, the knowledge of the solar radiation partitioning into direct and diffuse radiation has become a major demand for the design and suitable orientation of solar panels in solar power plants. In this study the first measurements of solar diffuse irradiance performed in the radiometric station in Badajoz (Spain) are presented and analyzed in the framework of the partitioning of solar global radiation. Thus, solar global and diffuse irradiance were measured at one-minute basis from 23 November 2009 to 31 March 2010. Solar irradiances were measured by two Kipp&Zonen CMP11 pyranometers, using a Kipp&Zonen CM121 shadow ring for the measurements of solar diffuse irradiance. Diffuse measurements were corrected from the solid angle hidden by the ring and direct irradiance was calculated as the difference between global and diffuse measurements. Irradiance was obtained from the pyranomenters by applying calibration coefficients obtained in an inter-comparison campaign performed at INTA/El Arenosillo, in Huelva (Spain), last September 2009. There, calibration coefficients were calculated using as a reference a CMP11 pyranometer which had been previously calibrated by the Physikalisch-Meteorologisches Observatorium Davos/World Radiation Centre in Switzerland. In order to study the partitioning of the solar radiation, the global and diffuse irradiances have been analyzed for three typical different sky conditions: cloud-free, broken clouds and overcast. Particular days within the period of study have been selected by visual inspection. Along with the analysis of the global and diffuse irradiances themselves, ratios of these irradiances to the downward irradiance at the

  16. Direct analysis of quantal radiation response data

    International Nuclear Information System (INIS)

    Thames, H.D. Jr.; Rozell, M.E.; Tucker, S.L.; Ang, K.K.; Travis, E.L.; Fisher, D.R.

    1986-01-01

    A direct analysis is proposed for quantal (all-or-nothing) responses to fractionated radiation and endpoint-dilution assays of cell survival. As opposed to two-step methods such as the reciprocal-dose technique, in which ED 50 values are first estimated for different fractionation schemes and then fit (as reciprocals) against dose per fraction, all raw data are included in a single maximum-likelihood treatment. The method accommodates variations such as short-interval fractionation regimens designed to determine tissue repair kinetics, tissue response to continuous exposures, and data obtained using endpoint-dilution assays of cell survival after fractionated doses. Monte-Carlo techniques were used to compare the direct and reciprocal-dose methods for analysis of small-scale and large-scale studies of response to fractionated doses. Both methods tended toward biased estimates in the analysis of small-scale (3 fraction numbers) studies. The α/β ratios showed less scatter when estimated by the direct method. The 95% confidence intervals determined by the direct method were more appropriate than those determined by reciprocal-dose analysis, for which 18% (small-scale study) or 8% (large-scale study) of the confidence intervals did not include the 'true' value of α/β. (author)

  17. Photometric estimation of defect size in radiation direction

    International Nuclear Information System (INIS)

    Zuev, V.M.

    1993-01-01

    Factors, affecting accuracy of photometric estimation of defect size in radiation transmission direction, are analyzed. Experimentally obtained dependences of contrast of defect image on its size in radiation transmission direction are presented. Practical recommendations on improving accuracy of photometric estimation of defect size in radiation transmission direction, are developed

  18. Solar Radiation effect on the bituminous binder; Efecto de la radiacion solar sobre el ligante bituminoso

    Energy Technology Data Exchange (ETDEWEB)

    Tadeo Rico, A.; Torres Perez, A.

    2010-07-01

    Asphalt, used as binder in road construction, becomes more brittle and harder during working life on the surface of the road pavement, conducting toward their deterioration. This is caused by the oxidation of the molecular functional groups of the asphalt molecular structure. Moreover, it is observed that ultraviolet radiation increases the oxidation process. However, the effect of solar light on the asphalt degradation has been poorly researched. The aim of this work is to study asphalt ageing caused by effect of solar radiation, by using standard test. Four commercial asphalts from different companies were selected: two with penetration number 50/70, and the other two polymer modified asphalts. From each of the asphalts forty samples were taken off and placed in four different aging conditions of temperature and radiation for a period ranging from 40 to 500 days. Ring and Ball test, and Fraass breaking Point test, were used to analyse the changes of asphalt properties after exposition to solar radiation. The results of the four analyzed asphalts showed a distinct behaviour; not only in the test temperature increase but also in the rate. Another experiment was carried out. Samples from a hot mix asphalt batch were placed under solar radiation, and were compacted by the Marshall procedure after increasing periods of time. Density and resistance to plastic flow using Marshall Apparatus were measured. Results showed an increase in the stability of samples under radiation. Both experiments show that the solar radiation is enough to cause changes in the asphalt molecular structure due to oxidation. So that, the study of the effect of the solar radiation on the asphalt properties could be a good tool to asses the performances of asphalt pavement. (Author) 26 refs.

  19. Solar radiation in Germany - observed trends and an assessment of their causes. Pt. 1; Regional approach

    Energy Technology Data Exchange (ETDEWEB)

    Liepert, B [Muenchen Univ., Freising (Germany). Lehrstuhl fuer Bioklimatologie und Immissionsforschung; Fabian, P [Muenchen Univ., Freising (Germany). Lehrstuhl fuer Bioklimatologie und Immissionsforschung; Grassl, H [Max-Planck-Institut fuer Meteorologie, Hamburg (Germany)

    1994-02-01

    The possible longterm variation of daily sums of global solar radiation (direct plus diffuse solar radiation) in West-Germany was analysed for twelve stations of the German Weather Service (DWD). The global solar radiation decreased remarkably at seven stations (List/Sylt, Norderney, Hamburg, Braunlage, Wuerzburg, Weihenstephan, Hohenpeissenberg) and showed no significant variations at the remaining five stations (Braunschweig, Bocholt, Gelsenkirchen, Trier and Freiburg). The average decline is 3.7[+-]1.3% per decade in the last 15 to 39 years. The locally varying causes for the decline are changes in cloud parameters, fog occurrence and tropospheric aerosol. In this part of the article some possible causes, such as solar variability, increased number of contrails, decreased surface reflectivity, increased volcanic aerosol load in the 1980's or increased water vapour column content could be excluded. With a more sophisticated statistical procedure the effect of changes in cloud parameters and the effect of changed clear sky turbidity could not only be separated for each month for Hohenpeissenberg and Wuerzburg but also made mainly responsible for the observed trend. In Part II (Grabbe, Grassl), more detailed observations of solar radiation hourly averages of Hamburg were analysed. (orig.)

  20. GLOBAL SOLAR RADIATION INTERCEPTION BY GRAPEVINES TRAINED TO A VERTICAL TRELLIS SYSTEM

    Directory of Open Access Journals (Sweden)

    CLAUDIA GUIMARÃES CAMARGO CAMPOS

    2016-01-01

    Full Text Available ABSTRACT In this paper we assess the utilization of radiant energy in the growing of grapevines (Cabernet Sauvignon trained to a vertical trellis system, and estimate the global solar radiation interception taking into account the physical characteristics of the training system at different phenological stages. The experiment was based on daily measurements of global solar radiation made by an automatic weather station placed at the vineyard of a winery located in the municipality of São Joaquim, in the southern Brazilian State of Santa Catarina (Villa Francioni winery, 28º 15’ 14” S, 49º 57’ 02” W, 1294m a.s.l.. Growth and phenological development of the shoots were evaluated. The global solar radiation is intercepted by the canopy (trained to a vertical trellis system in different orientations and the accumulated total is slightly greater on the east than on the west face of the canopy, especially after flowering. The daily variability of global solar radiation intercepted by the canopy is greater after flowering. The accumulated solar energy incident on the canopy increases until the onset of ripening. From the results, vineyards trained to a vertical trellis system in the north-south direction provide favorable sunlight exposure to leaves and fruits and are promising in quality and productivity.

  1. Evidence for Solar Cycle Influence on the Infrared Energy Budget and Radiative Cooling of the Thermosphere

    Science.gov (United States)

    Mlynczak, Martin G.; Martin-Torres, F. Javier; Marshall, B. Thomas; Thompson, R. Earl; Williams, Joshua; Turpin, TImothy; Kratz, D. P.; Russell, James M.; Woods, Tom; Gordley, Larry L.

    2007-01-01

    We present direct observational evidence for solar cycle influence on the infrared energy budget and radiative cooling of the thermosphere. By analyzing nearly five years of data from the Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) instrument, we show that the annual mean infrared power radiated by the nitric oxide (NO) molecule at 5.3 m has decreased by a factor of 2.9. This decrease is correlated (r = 0.96) with the decrease in the annual mean F10.7 solar index. Despite the sharp decrease in radiated power (which is equivalent to a decrease in the vertical integrated radiative cooling rate), the variability of the power as given in the standard deviation of the annual means remains approximately constant. A simple relationship is shown to exist between the infrared power radiated by NO and the F10.7 index, thus providing a fundamental relationship between solar activity and the thermospheric cooling rate for use in thermospheric models. The change in NO radiated power is also consistent with changes in absorbed ultraviolet radiation over the same time period.

  2. Fiscal 1974 Sunshine Project result report. R and D on solar energy system (weather survey). Part 1. Bibliography on solar radiation; 1974 nendo taiyo hosha ni kansuru bunken mokuroku. 1. Taiyo energy system no kenkyu kaihatsu (kisho chosa)

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1975-03-01

    This report is the 1st one among 3 reports 'Bibliography on solar radiation', 'Guideline for using weather data' and 'Observation data on global solar radiation and sunshine duration'. This report is composed of the part 1 'Present state and view of researches on solar radiation' including (1) view of researches on short-wave radiation, (2) atmospheric radiation, (3) scattering of solar radiation, (4) global net radiation and (5) radiometer, and the part 2 including the bibliography and its commentary. (1) describes researches on incident short-wave radiation (solar radiation) and some current issues, (2) describes the basis for quantitative measurement of atmospheric radiation transfer, based on the premise that atmospheric radiation is infrared radiation between the ground surface and atmospheric system. (3) describes scattering of solar radiation in the air, and its effect. (4) describes that the global profile of net radiation of the air-earth system and its seasonal change can be observed directly from the weather satellite roughly, and research on global net radiation is approaching a new era. (NEDO)

  3. Fiscal 1974 Sunshine Project result report. R and D on solar energy system (weather survey). Part 1. Bibliography on solar radiation; 1974 nendo taiyo hosha ni kansuru bunken mokuroku. 1. Taiyo energy system no kenkyu kaihatsu (kisho chosa)

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1975-03-01

    This report is the 1st one among 3 reports 'Bibliography on solar radiation', 'Guideline for using weather data' and 'Observation data on global solar radiation and sunshine duration'. This report is composed of the part 1 'Present state and view of researches on solar radiation' including (1) view of researches on short-wave radiation, (2) atmospheric radiation, (3) scattering of solar radiation, (4) global net radiation and (5) radiometer, and the part 2 including the bibliography and its commentary. (1) describes researches on incident short-wave radiation (solar radiation) and some current issues, (2) describes the basis for quantitative measurement of atmospheric radiation transfer, based on the premise that atmospheric radiation is infrared radiation between the ground surface and atmospheric system. (3) describes scattering of solar radiation in the air, and its effect. (4) describes that the global profile of net radiation of the air-earth system and its seasonal change can be observed directly from the weather satellite roughly, and research on global net radiation is approaching a new era. (NEDO)

  4. Radiation aspects on the Earth's surface during solar flares

    International Nuclear Information System (INIS)

    Mansurov, K.Zh.; Aitmukhambetov, A.A.

    2002-01-01

    In the paper the results of investigation of radiation solution in the space near the Earth at the different altitudes of the Earth atmosphere and at the ground level in dependence on geo-coordinates and solar activity during 1957-1999 are presented. Radiation is due to the Galactic cosmic ray flux for different periods of the Solar activity: - the radiation doses of the radioactive clouds at latitudes ∼12-13 km which go ground the Earth two or three times were created; - it seems to years that these clouds make a certain contribution to the ecological situation in the Earth atmosphere and on the surface. The radiation near ground level of the Earth for the last 1500 years was calculated also using the data of radioactive carbon 14 C intensity investigation

  5. Measurement of global solar radiation over Brunei Darussalam

    International Nuclear Information System (INIS)

    Malik, A.Q.; Ak Abd Malik Abd Raub Pg Ghani

    2006-01-01

    Measurements of global solar radiation on a horizontal surface were carried out for a period of 11 months starting from June 2001 to April 2002. The pyrano meter (Kipp and Zonen) was placed at the top of the library building of University of Brunei Darussalam, which affords optimum exposure to the instrument sensor without appreciable obstacle for incoming global radiation. The maximum and minimum monthly-averaged global irradiations of 553 W/m 2 and 433 W/m 2 were recorded for the months of March and October respectively. The variation of global solar radiation can be divided into two distinct groups - the low radiation values being associated with cloud and turbidity while the high values are associated with less turbid and cloudy periods

  6. Solar Rotational Periodicities and the Semiannual Variation in the Solar Wind, Radiation Belt, and Aurora

    Science.gov (United States)

    Emery, Barbara A.; Richardson, Ian G.; Evans, David S.; Rich, Frederick J.; Wilson, Gordon R.

    2011-01-01

    The behavior of a number of solar wind, radiation belt, auroral and geomagnetic parameters is examined during the recent extended solar minimum and previous solar cycles, covering the period from January 1972 to July 2010. This period includes most of the solar minimum between Cycles 23 and 24, which was more extended than recent solar minima, with historically low values of most of these parameters in 2009. Solar rotational periodicities from S to 27 days were found from daily averages over 81 days for the parameters. There were very strong 9-day periodicities in many variables in 2005 -2008, triggered by recurring corotating high-speed streams (HSS). All rotational amplitudes were relatively large in the descending and early minimum phases of the solar cycle, when HSS are the predominant solar wind structures. There were minima in the amplitudes of all solar rotational periodicities near the end of each solar minimum, as well as at the start of the reversal of the solar magnetic field polarity at solar maximum (approx.1980, approx.1990, and approx. 2001) when the occurrence frequency of HSS is relatively low. Semiannual equinoctial periodicities, which were relatively strong in the 1995-1997 solar minimum, were found to be primarily the result of the changing amplitudes of the 13.5- and 27-day periodicities, where 13.5-day amplitudes were better correlated with heliospheric daily observations and 27-day amplitudes correlated better with Earth-based daily observations. The equinoctial rotational amplitudes of the Earth-based parameters were probably enhanced by a combination of the Russell-McPherron effect and a reduction in the solar wind-magnetosphere coupling efficiency during solstices. The rotational amplitudes were cross-correlated with each other, where the 27 -day amplitudes showed some of the weakest cross-correlations. The rotational amplitudes of the > 2 MeV radiation belt electron number fluxes were progressively weaker from 27- to 5-day periods

  7. Radiative magnetohydrodynamic simulations of solar pores

    NARCIS (Netherlands)

    Cameron, R.; Schuessler, M.; Vögler, A.; Zakharov, V.

    2007-01-01

    Context. Solar pores represent a class of magnetic structures intermediate between small-scale magnetic flux concentrations in intergranular lanes and fully developed sunspots with penumbrae. Aims. We study the structure, energetics, and internal dynamics of pore-like magnetic structures by means of

  8. Inconing solar radiation estimates at terrestrial surface using meteorological satellite

    International Nuclear Information System (INIS)

    Arai, N.; Almeida, F.C. de.

    1982-11-01

    By using the digital images of the visible channel of the GOES-5 meteorological satellite, and a simple radiative transfer model of the earth's atmosphere, the incoming solar radiation reaching ground is estimated. A model incorporating the effects of Rayleigh scattering and water vapor absorption, the latter parameterized using the surface dew point temperature value, is used. Comparisons with pyranometer observations, and parameterization versus radiosonde water vapor absorption calculation are presented. (Author) [pt

  9. Radiation Modeling with Direct Simulation Monte Carlo

    Science.gov (United States)

    Carlson, Ann B.; Hassan, H. A.

    1991-01-01

    Improvements in the modeling of radiation in low density shock waves with direct simulation Monte Carlo (DSMC) are the subject of this study. A new scheme to determine the relaxation collision numbers for excitation of electronic states is proposed. This scheme attempts to move the DSMC programs toward a more detailed modeling of the physics and more reliance on available rate data. The new method is compared with the current modeling technique and both techniques are compared with available experimental data. The differences in the results are evaluated. The test case is based on experimental measurements from the AVCO-Everett Research Laboratory electric arc-driven shock tube of a normal shock wave in air at 10 km/s and .1 Torr. The new method agrees with the available data as well as the results from the earlier scheme and is more easily extrapolated to di erent ow conditions.

  10. Direct solar pumping of semiconductor lasers: A feasibility study

    Science.gov (United States)

    Anderson, Neal G.

    1992-01-01

    This report describes results of NASA Grant NAG-1-1148, entitled Direct Solar Pumping of Semiconductor Lasers: A Feasibility Study. The goals of this study were to provide a preliminary assessment of the feasibility of pumping semiconductor lasers in space with directly focused sunlight and to identify semiconductor laser structures expected to operate at the lowest possible focusing intensities. It should be emphasized that the structures under consideration would provide direct optical-to-optical conversion of sunlight into laser light in a single crystal, in contrast to a configuration consisting of a solar cell or storage battery electrically pumping a current injection laser. With external modulation, such lasers could perhaps be efficient sources for intersatellite communications. We proposed specifically to develop a theoretical model of semiconductor quantum-well lasers photopumped by a broadband source, test it against existing experimental data where possible, and apply it to estimating solar pumping requirements and identifying optimum structures for operation at low pump intensities. These tasks have been accomplished, as described in this report of our completed project. The report is organized as follows: Some general considerations relevant to the solar-pumped semiconductor laser problem are discussed in Section 2, and the types of structures chosen for specific investigation are described. The details of the laser model we developed for this work are then outlined in Section 3. In Section 4, results of our study are presented, including designs for optimum lattice-matched and strained-layer solar-pumped quantum-well lasers and threshold pumping estimates for these structures. It was hoped at the outset of this work that structures could be identified which could be expected to operate continuously at solar photoexcitation intensities of several thousand suns, and this indeed turned out to be the case as described in this section. Our project is

  11. Estimating shortwave solar radiation using net radiation and meteorological measurements

    Science.gov (United States)

    Shortwave radiation has a wide variety of uses in land-atmosphere interactions research. Actual evapotranspiration estimation that involves stomatal conductance models like Jarvis and Ball-Berry require shortwave radiation to estimate photon flux density. However, in most weather stations, shortwave...

  12. The role of solar ultraviolet radiation in 'natural' water purification

    International Nuclear Information System (INIS)

    Calkins, J.; Buckles, J.D.; Moeller, J.R.

    1976-01-01

    The concentration of Eschericia coli in the input and output of a tertiary wastewater system (4 lagoons) has been monitored over an 11 month period. The integrated flux of biologically active solar ultraviolet (UV) radiation was measured during this period. By also determining (1) the effective temperature in the system, (2) the growth rate of E.coli at the effective temperature, (3) the penetration of the solar UV into the lagoons, (4) the dose-response relation for killing of E.coli by UV and (5) the retention time of water in the system, it is possible to compare the 'die off' expected from solar UV exposure to the actual 'die off' observed for different batches of water. The observed killing of E.coli was quite close to the values calculated, considering the numerous factors involved. Solar UV light would thus seem to be a very important factor in the natural purification of water. Because each successful species must possess characteristics (physiological or behavioral) which provide adequate resistance to solar UV, the ecological role of solar UV radiation has not been widely appreciated. (author)

  13. Role of solar ultraviolet radiation in 'natural' water purification

    Energy Technology Data Exchange (ETDEWEB)

    Calkins, J; Buckles, J D; Moeller, J R [Kentucky Univ., Lexington (USA)

    1976-07-01

    The concentration of Eschericia coli in the input and output of a tertiary wastewater system (4 lagoons) has been monitored over an 11 month period. The integrated flux of biologically active solar ultraviolet (UV) radiation was measured during this period. By also determining (1) the effective temperature in the system, (2) the growth rate of E.coli at the effective temperature, (3) the penetration of the solar UV into the lagoons, (4) the dose-response relation for killing of E.coli by UV and (5) the retention time of water in the system, it is possible to compare the 'die off' expected from solar UV exposure to the actual 'die off' observed for different batches of water. The observed killing of E.coli was quite close to the values calculated, considering the numerous factors involved. Solar UV light would thus seem to be a very important factor in the natural purification of water. Because each successful species must possess characteristics (physiological or behavioral) which provide adequate resistance to solar UV, the ecological role of solar UV radiation has not been widely appreciated.

  14. Photodegradation of antibiotics under simulated solar radiation: implications for their environmental fate.

    Science.gov (United States)

    Batchu, Sudha Rani; Panditi, Venkata R; O'Shea, Kevin E; Gardinali, Piero R

    2014-02-01

    Roxithromycin, erythromycin, ciprofloxacin and sulfamethoxazole are frequently detected antibiotics in environmental waters. Direct and indirect photolysis of these problematic antibiotics were investigated in pure and natural waters (fresh and salt water) under irradiation of different light sources. Fundamental photolysis parameters such as molar absorption coefficient, quantum yield and first order rate constants are reported and discussed. The antibiotics are degraded fastest under ultraviolet 254 nm, followed by 350 nm and simulated solar radiation. The composition of the matrix (pH, dissolved organic content, chloride ion concentration) played a significant role in the observed photodegradation. Under simulated solar radiation, ciprofloxacin and sulfamethoxazole degrade relatively quickly with half-lives of 0.5 and 1.5h, respectively. However, roxithromycin and erythromycin, macrolides are persistent (half-life: 2.4-10 days) under solar simulation. The transformation products (15) of the targeted antibiotics produced under irradiation experiments were identified using high resolution mass spectrometry and degradation pathways were proposed. © 2013.

  15. Direct tracking error characterization on a single-axis solar tracker

    International Nuclear Information System (INIS)

    Sallaberry, Fabienne; Pujol-Nadal, Ramon; Larcher, Marco; Rittmann-Frank, Mercedes Hannelore

    2015-01-01

    Highlights: • The solar tracker of a small-size parabolic trough collector was tested. • A testing procedure for the tracking error characterization of a single-axis tracker was proposed. • A statistical analysis on the tracking error distribution was done regarding different variables. • The optical losses due to the tracking error were calculated based on a ray-tracing simulation. - Abstract: The solar trackers are devices used to orientate solar concentrating systems in order to increase the focusing of the solar radiation on a receiver. A solar concentrator with a medium or high concentration ratio needs to be orientated correctly by an accurate solar tracking mechanism to avoid losing the sunrays out from the receiver. Hence, to obtain an appropriate operation, it is important to know the accuracy of a solar tracker in regard to the required precision of the concentrator in order to maximize the collector optical efficiency. A procedure for the characterization of the accuracy of a solar tracker is presented for a single-axis solar tracker. More precisely, this study focuses on the estimation of the positioning angle error of a parabolic trough collector using a direct procedure. A testing procedure, adapted from the International standard IEC 62817 for photovoltaic trackers, was defined. The results show that the angular tracking error was within ±0.4° for this tracker. The optical losses due to the tracking were calculated using the longitudinal incidence angle modifier obtained by ray-tracing simulation. The acceptance angles for various transversal angles were analyzed, and the average optical loss, due to the tracking, was 0.317% during the whole testing campaign. The procedure presented in this work showed that the tracker precision was adequate for the requirements of the analyzed optical system.

  16. new model for solar radiation estimation from measured air

    African Journals Online (AJOL)

    HOD

    RMSE) and correlation ... countries due to the unavailability of measured data in place [3-5]. ... models were used to predict solar radiation in Nigeria by. [12-15]. However ..... "Comparison of Gene Expression Programming with neuro-fuzzy and ...

  17. Improved Solar-Radiation-Pressure Models for GPS Satellites

    Science.gov (United States)

    Bar-Sever, Yoaz; Kuang, Da

    2006-01-01

    A report describes a series of computational models conceived as an improvement over prior models for determining effects of solar-radiation pressure on orbits of Global Positioning System (GPS) satellites. These models are based on fitting coefficients of Fourier functions of Sun-spacecraft- Earth angles to observed spacecraft orbital motions.

  18. Glacial Influences on Solar Radiation in a Subarctic Sea.

    Science.gov (United States)

    Understanding macroscale processes controlling solar radia­tion in marine systems will be important in interpreting the potential effects of global change from increasing ultraviolet radiation (UV) and glacial retreat. This study provides the first quantitative assessment of UV i...

  19. Effect of solar radiation on surface ozone in Cairo

    Energy Technology Data Exchange (ETDEWEB)

    Rizk, H F.S. [National Research Centre, Air Pollution Research Dept., Cairo (Egypt)

    1992-04-01

    Measurements of surface ozone content over an urban area in Cairo were conducted during a year, May 1989 to April 1990, while solar radiation at the same area was measured. Low and high concentrations of ozone are compared with those recommended by the WHO expert committee regarding the daily cycle of ozone concentration. 15 refs.

  20. Empirical Models for the Estimation of Global Solar Radiation in ...

    African Journals Online (AJOL)

    Empirical Models for the Estimation of Global Solar Radiation in Yola, Nigeria. ... and average daily wind speed (WS) for the interval of three years (2010 – 2012) measured using various instruments for Yola of recorded data collected from the Center for Atmospheric Research (CAR), Anyigba are presented and analyzed.

  1. A comparison of outer electron radiation belt dropouts during solar ...

    Indian Academy of Sciences (India)

    Utilizing multiple data sources from the year 1997–2007, this study identifies radiation belt electron dropouts which are ultimately triggered when solar wind stream interfaces (SI) arrived at ... Center for Space Research, School for Physical and Chemical Sciences, North–West University, Potchefstroom 2520, South Africa.

  2. Listing of solar radiation measuring equipment and glossary

    Science.gov (United States)

    Carter, E. A.; Greenbaum, S. A.; Patel, A. M.

    1976-01-01

    An attempt is made to list and provide all available information about solar radiation measuring equipment which are being manufactured and are available on the market. The list is in tabular form and includes sensor type, response time, cost data and comments for each model. A cost code is included which shows ranges only.

  3. Ultraviolet solar radiation and the prevention of erythema

    International Nuclear Information System (INIS)

    Tena, F.; Martinez-Lozano, J.A.; Utrillas, M.P.

    1998-01-01

    An ultraviolet index appropriate for its use in Spain is studied on the basis of those already available in other countries. The suitability of this index to characterise ultraviolet solar radiation and, particularly, the potential risks to human health are discussed. Finally, the main factors affecting this index are identified and their influence is studied. (Author) 43 refs

  4. Estimation of solar radiation energy of Ethiopia from sunshine data

    Energy Technology Data Exchange (ETDEWEB)

    Argaw, N. [Tampere Univ., Dep. of Civil Engineering, Tampere (Finland)

    1996-12-31

    Measurements of global solar radiation on a horizontal surface, for nine meteorological stations in Ethiopia, are compared with their corresponding values computed based on Angstroem relations. Regression coefficients are obtained and correlation equations are determined to predict the global solar radiation. The results shows that Angstroem relations are valid for Ethiopian locations, and the correlation equations can be used to predict the monthly mean daily global solar radiation in the locations considered in this study. This study also proves that the results made by ENEC et al, using the generalised Frere`s coefficients, is unsatisfactory for the prediction of monthly mean daily global solar radiation. On the other hand, the work of Dogniaux and Lemoine, using the regression coefficients a and b as a function of latitude and atmospheric turbidity and grouping large range latitudes to extend the application, can give better estimation. However, for more accurate estimation, several additional meteorological stations have to be evaluated and their regression coefficients have to be determined before grouping in to one relationship to express the variations of a and b under any conditions of equipment and location. (author) 1 fig., 11 tabs., 22 refs.

  5. Ambient solar UV radiation and seasonal trends in potential sunburn ...

    African Journals Online (AJOL)

    Background. The detrimental effects of excess personal solar ultraviolet (UV) radiation exposure include sunburn, immunosuppression and skin cancer. In South Africa, individuals with minimum natural protection from melanin, including fair-skinned individuals and African albinos, and people spending extended ...

  6. Comparison Of Diffuse Solar Radiation Models Using Data For ...

    African Journals Online (AJOL)

    Measurements of global solar radiation and sunshine duration data during the period from 1984 to 1999 were supplied by IITA (International Institute of Tropical Agriculture) at Onne. The data were used to establish empirical relationships that would connect the daily monthly average diffuse irradiation with both relative ...

  7. Galactic and solar radiation exposure to aircrew during a solar cycle

    International Nuclear Information System (INIS)

    Lewis, B.J.; Bennett, L.G.I.; Green, A.R.; McCall, M.J.; Ellaschuk, B.; Butler, A.; Pierre, M.

    2002-01-01

    An on-going investigation using a tissue-equivalent proportional counter (TEPC) has been carried out to measure the ambient dose equivalent rate of the cosmic radiation exposure of aircrew during a solar cycle. A semi-empirical model has been derived from these data to allow for the interpolation of the dose rate for any global position. The model has been extended to an altitude of up to 32 km with further measurements made on board aircraft and several balloon flights. The effects of changing solar modulation during the solar cycle are characterised by correlating the dose rate data to different solar potential models. Through integration of the dose-rate function over a great circle flight path or between given waypoints, a Predictive Code for Aircrew Radiation Exposure has been further developed for estimation of the route dose from galactic cosmic radiation exposure. This estimate is provided in units of ambient dose equivalent as well as effective dose, based on E/H*(10) scaling functions as determined from transport code calculations with LUIN and FLUKA. This experimentally based treatment has also been compared with the CARI-6 and EPCARD codes that are derived solely from theoretical transport calculations. Using TEPC measurements taken aboard the International Space Station, ground based neutron monitoring, GOES satellite data and transport code analysis, an empirical model has been further proposed for estimation of aircrew exposure during solar particle events. This model has been compared to results obtained during recent solar flare events. (author)

  8. Assessment and comparison of methods for solar ultraviolet radiation measurements

    Energy Technology Data Exchange (ETDEWEB)

    Leszczynski, K

    1995-06-01

    In the study, the different methods to measure the solar ultraviolet radiation are compared. The methods included are spectroradiometric, erythemally weighted broadband and multi-channel measurements. The comparison of the different methods is based on a literature review and assessments of optical characteristics of the spectroradiometer Optronic 742 of the Finnish Centre for Radiation and Nuclear Safety (STUK) and of the erythemally weighted Robertson-Berger type broadband radiometers Solar Light models 500 and 501 of the Finnish Meteorological Institute and STUK. An introduction to the sources of error in solar UV measurements, to methods for radiometric characterization of UV radiometers together with methods for error reduction are presented. Reviews on experiences from world-wide UV monitoring efforts and instrumentation as well as on the results from international UV radiometer intercomparisons are also presented. (62 refs.).

  9. Assessment and comparison of methods for solar ultraviolet radiation measurements

    International Nuclear Information System (INIS)

    Leszczynski, K.

    1995-06-01

    In the study, the different methods to measure the solar ultraviolet radiation are compared. The methods included are spectroradiometric, erythemally weighted broadband and multi-channel measurements. The comparison of the different methods is based on a literature review and assessments of optical characteristics of the spectroradiometer Optronic 742 of the Finnish Centre for Radiation and Nuclear Safety (STUK) and of the erythemally weighted Robertson-Berger type broadband radiometers Solar Light models 500 and 501 of the Finnish Meteorological Institute and STUK. An introduction to the sources of error in solar UV measurements, to methods for radiometric characterization of UV radiometers together with methods for error reduction are presented. Reviews on experiences from world-wide UV monitoring efforts and instrumentation as well as on the results from international UV radiometer intercomparisons are also presented. (62 refs.)

  10. Estimation of clear sky hourly global solar radiation in Iraq

    Energy Technology Data Exchange (ETDEWEB)

    Al-Jumaily, Kais J.; Al-Zuhairi, Munya F.; Mahdi, Zahraa S. [Department of Atmospheric Sciences, College of Science, Al-Mustansiriyah University, Baghdad (Iraq)

    2012-07-01

    The availability of hourly solar radiation data is very important for applications utilizing solar energy and for climate and environmental aspects. The aim of this work is to use a simple model for estimating hourly global solar radiation under clear sky condition in Iraq. Calculations were compared with measurements obtained from local station in Baghdad city and from Meteosat satellite data for different locations in Iraq. The statistical test methods of the mean bias error (MBE), root mean square error (RMSE) and t-test were used to evaluate the performance of the model. Results indicated that a fairly good agreement exists between calculated and measured values for all locations in Iraq. Since the model is independent of any meteorological variable, it would be of a practical use for rural areas where no meteorological data are available.

  11. A concentrated solar cavity absorber with direct heat transfer through recirculating metallic particles

    Energy Technology Data Exchange (ETDEWEB)

    Sarker, M. R. I., E-mail: islamrabiul@yahoo.com; Saha, Manabendra, E-mail: manabendra.saha@adelaide.edu.au, E-mail: manab04me@gmail.com; Beg, R. A. [Department of Mechanical Engineering, Rajshahi University of Engineering and Technology, Rajshahi-6204 (Bangladesh)

    2016-07-12

    A recirculating flow solar particle cavity absorber (receiver) is modeled to investigate the flow behavior and heat transfer characteristics of a novel developing concept. It features a continuous recirculating flow of non-reacting metallic particles (black silicon carbide) with air which are used as a thermal enhancement medium. The aim of the present study is to numerically investigate the thermal behavior and flow characteristics of the proposed concept. The proposed solar particle receiver is modeled using two phase discrete particle model (DPM), RNG k-flow model and discrete ordinate (DO) radiation model. Numerical analysis is carried out considering a solar receiver with only air and the mixture of non-reacting particles and air as a heat transfer as well as heat carrying medium. The parametric investigation is conducted considering the incident solar flux on the receiver aperture and changing air flow rate and recirculation rate inside the receiver. A stand-alone feature of the recirculating flow solar particle receiver concept is that the particles are directly exposed to concentrated solar radiation monotonously through recirculating flow inside the receiver and results in efficient irradiation absorption and convective heat transfer to air that help to achieve high temperature air and consequently increase in thermal efficiency. This paper presents, results from the developed concept and highlights its flow behavior and potential to enhance the heat transfer from metallic particles to air by maximizing heat carrying capacity of the heat transfer medium. The imposed milestones for the present system will be helpful to understand the radiation absorption mechanism of the particles in a recirculating flow based receiver, the thermal transport between the particles, the air and the cavity, and the fluid dynamics of the air and particle in the cavity.

  12. The solar energy in Colombia, Atlas of solar radiation of Colombia

    International Nuclear Information System (INIS)

    Rodriguez P, F.

    1995-01-01

    This study was made by means of the Agreement inter-institutional subscribed between Mines Ministry and Energy, HIMAT and INEA and was published by CARBOCOL. In the evaluation of solar energy potential, the information of the radiometric net of the HIMAT taken in 203 stations distributed throughout all Country from 1980 until 1990, it was had in account. A meteorological station is an observation point where are located different instruments and equipment that serve to measure and study meteorological parameter as solar radiation (radiometer actinograph), Solar sheen (Campbell Stoke), Temperature (Thermograph), Moisture (hydrographer), Wind (Anemograph Anemometer) and Precipitation (Pluviograph)

  13. Increasing the temporal resolution of direct normal solar irradiance forecasted series

    Science.gov (United States)

    Fernández-Peruchena, Carlos M.; Gastón, Martin; Schroedter-Homscheidt, Marion; Marco, Isabel Martínez; Casado-Rubio, José L.; García-Moya, José Antonio

    2017-06-01

    A detailed knowledge of the solar resource is a critical point in the design and control of Concentrating Solar Power (CSP) plants. In particular, accurate forecasting of solar irradiance is essential for the efficient operation of solar thermal power plants, the management of energy markets, and the widespread implementation of this technology. Numerical weather prediction (NWP) models are commonly used for solar radiation forecasting. In the ECMWF deterministic forecasting system, all forecast parameters are commercially available worldwide at 3-hourly intervals. Unfortunately, as Direct Normal solar Irradiance (DNI) exhibits a great variability due to the dynamic effects of passing clouds, 3-h time resolution is insufficient for accurate simulations of CSP plants due to their nonlinear response to DNI, governed by various thermal inertias due to their complex response characteristics. DNI series of hourly or sub-hourly frequency resolution are normally used for an accurate modeling and analysis of transient processes in CSP technologies. In this context, the objective of this study is to propose a methodology for generating synthetic DNI time series at 1-h (or higher) temporal resolution from 3-h DNI series. The methodology is based upon patterns as being defined with help of the clear-sky envelope approach together with a forecast of maximum DNI value, and it has been validated with high quality measured DNI data.

  14. Performance of direct absorption solar collector with nanofluid mixture

    International Nuclear Information System (INIS)

    Turkyilmazoglu, Mustafa

    2016-01-01

    Highlights: • Neat approximations for temperature and solar collector efficiency are presented. • The non-adiabatic and isothermal base mechanisms optimize the surface absorption. • Heat transferring material at the bottom panel enhances the thermal efficiency. • Isothermal base panel leads to maximum thermal efficiency of the solar receiver. - Abstract: The enhancement of performance by increasing the thermal efficiency of a direct absorption solar collector based on an alumina–water nanofluid is the prime target of the present research. The base panel of the collector channel is subject to either a non adiabatic or an isothermal wall condition both of which introduce two new physical parameters. Analytical solutions for the temperature field are worked out in both cases for a two dimensional steady-state model recently outlined in the literature. The desired increase in the temperature of the heat transferring nanofluid is achieved either by slightly rising the heat transfer coefficient of the bottom panel coating or by prescribing a bottom surface temperature. As a consequence of the increase in the final outlet mean temperature, the solar collector thermal efficiency is found to be enhanced via increasing the new physical parameters as compared to the traditional adiabatic wall case. For instance, 85.63% thermal efficiency of solar collector is achievable for non adiabatic bottom panel by adding suspended aluminum nanoparticles into the pure water. Even better than this, considering isothermal base panels, 100% efficiency is attained more rapidly with lesser base temperatures in the presence of higher nanoparticle volume fractions.

  15. Development of software for estimating clear sky solar radiation in Indonesia

    Science.gov (United States)

    Ambarita, H.

    2017-01-01

    Research on solar energy applications in Indonesia has come under scrutiny in recent years. Solar radiation is harvested by solar collector or solar cell and convert the energy into useful energy such as heat and or electricity. In order to provide a better configuration of a solar collector or a solar cell, clear sky radiation should be estimated properly. In this study, an in-house software for estimating clear sky radiation is developed. The governing equations are solved simultaneously. The software is tested in Medan city by performing a solar radiation measurements. For clear sky radiation, the results of the software and measurements ones show a good agreement. However, for the cloudy sky condition it cannot predict the solar radiation. This software can be used to estimate the clear sky radiation in Indonesia.

  16. Performance analysis of an Integrated Solar Combined Cycle using Direct Steam Generation in parabolic trough collectors

    International Nuclear Information System (INIS)

    Montes, M.J.; Rovira, A.; Munoz, M.; Martinez-Val, J.M.

    2011-01-01

    Highlights: → Solar hybridization improves the performance of CCGT in a very hot and dry weather. → The scheme analyzed is a DSG parabolic trough field coupled to the Rankine cycle. → An annual simulation has been carried out for two locations: Almeria and Las Vegas. → Economical analysis shows that this scheme is a cheaper way to exploit solar energy. → For that, solar hybridization must be limited to a small fraction of the CCGT power. - Abstract: The contribution of solar thermal power to improve the performance of gas-fired combined cycles in very hot and dry environmental conditions is analyzed in this work, in order to assess the potential of this technique, and to feature Direct Steam Generation (DSG) as a well suited candidate for achieving very good results in this quest. The particular Integrated Solar Combined Cycle (ISCC) power plant proposed consists of a DSG parabolic trough field coupled to the bottoming steam cycle of a Combined Cycle Gas Turbine (CCGT) power plant. For this analysis, the solar thermal power plant performs in a solar dispatching mode: the gas turbine always operates at full load, only depending on ambient conditions, whereas the steam turbine is somewhat boosted to accommodate the thermal hybridization from the solar field. Although the analysis is aimed to studying such complementary effects in the widest perspective, two relevant examples are given, corresponding to two well-known sites: Almeria (Spain), with a mediterranean climate, and Las Vegas (USA), with a hot and dry climate. The annual simulations show that, although the conventional CCGT power plant works worse in Las Vegas, owing to the higher temperatures, the ISCC system operates better in Las Vegas than in Almeria, because of solar hybridization is especially well coupled to the CCGT power plant in the frequent days with great solar radiation and high temperatures in Las Vegas. The complementary effect will be clearly seen in these cases, because the thermal

  17. Effects of solar radiation on hair and photoprotection.

    Science.gov (United States)

    Dario, Michelli F; Baby, André R; Velasco, Maria Valéria R

    2015-12-01

    In this paper the negative effects of solar radiation (ultraviolet, visible and infrared wavelengths) on hair properties like color, mechanical properties, luster, protein content, surface roughness, among others, will be discussed. Despite knowing that radiation damages hair, there are no consensus about the particular effect of each segment of solar radiation on the hair shaft. The hair photoprotection products are primarily targeted to dyed hair, specially auburn pigments, and gray shades. They are usually based on silicones, antioxidants and quaternary chemical UV filters that have more affinity for negatively charged hair surface and present higher efficacy. Unfortunately, there are no regulated parameters, like for skin photoprotection, for efficacy evaluation of hair care products, which makes impossible to compare the results published in the literature. Thus, it is important that researchers make an effort to apply experimental conditions similar to a real level of sun exposure, like dose, irradiance, time, temperature and relative humidity. Copyright © 2015 Elsevier B.V. All rights reserved.

  18. Radiation Environments for Future Human Exploration Throughout the Solar System.

    Science.gov (United States)

    Schwadron, N.; Gorby, M.; Linker, J.; Riley, P.; Torok, T.; Downs, C.; Spence, H. E.; Desai, M. I.; Mikic, Z.; Joyce, C. J.; Kozarev, K. A.; Townsend, L. W.; Wimmer-Schweingruber, R. F.

    2016-12-01

    Acute space radiation hazards pose one of the most serious risks to future human and robotic exploration. The ability to predict when and where large events will occur is necessary in order to mitigate their hazards. The largest events are usually associated with complex sunspot groups (also known as active regions) that harbor strong, stressed magnetic fields. Highly energetic protons accelerated very low in the corona by the passage of coronal mass ejection (CME)-driven compressions or shocks and from flares travel near the speed of light, arriving at Earth minutes after the eruptive event. Whether these particles actually reach Earth, the Moon, Mars (or any other point) depends on their transport in the interplanetary magnetic field and their magnetic connection to the shock. Recent contemporaneous observations during the largest events in almost a decade show the unique longitudinal distributions of this ionizing radiation broadly distributed from sources near the Sun and yet highly isolated during the passage of CME shocks. Over the last decade, we have observed space weather events as the solar wind exhibits extremely low densities and magnetic field strengths, representing states that have never been observed during the space age. The highly abnormal solar activity during cycles 23 and 24 has caused the longest solar minimum in over 80 years and continues into the unusually small solar maximum of cycle 24. As a result of the remarkably weak solar activity, we have also observed the highest fluxes of galactic cosmic rays in the space age and relatively small particle radiation events. We have used observations from LRO/CRaTER to examine the implications of these highly unusual solar conditions for human space exploration throughout the inner solar system. While these conditions are not a show-stopper for long-duration missions (e.g., to the Moon, an asteroid, or Mars), galactic cosmic ray radiation remains a significant and worsening factor that limits

  19. Water disinfection with solar radiation; Desinfeccion del agua con radiacion solar

    Energy Technology Data Exchange (ETDEWEB)

    Martin, Alejandra; Cortes, Juana E; Rodriguez, Miriam; Mundo, Alfredo; Vazquez, Sandra [Instituto Mexicano de Tecnologia del Agua, Jiutepec, Morelos (Mexico); Estrada, Claudio A [Centro de Investigacion en Energia, Temixco, Morelos (Mexico)

    2000-07-01

    Water disinfection by exposure to solar radiation is a low cost and easy application option to rural communities. The treatment of water can be done using plastic bags or plastic bottles of two litters setting on a reflective material. The efficient of the plastic bottles is lower than the one plastic bags, but the plastic bottles have a much better control of the treated water avoiding its recontamination. In order to increase the efficiency of disinfection using plastic bottles, two solar concentrators, using flat mirrors, were designed and built. Effluent water from a treatment plant of residual waters was used for the testing. Several comparison were carried out taking into account the position of the concentrators, the transparency of the bottles and the bags. The results show that using the concentrator that adjust its position to the sun every hour, a 100% disinfection is obtained in 4 hours of direct exposure to the sun rays in a sunny day. The period of time can be reduced up to 2 hours, if instead using transparent bottles, the bottles are black painted at their bottom half. With these results, the basis to design a cheap concentrator of easy construction to be used in rural communities have been settle. [Spanish] La desinfeccion del agua por exposicion a la luz solar fotodesinfeccion es una opcion de bajo costo y facil aplicacion para las comunidades rurales. El tratamiento puede llevarse a cabo utilizando bolsas o botellas de plastico transparente de dos litros de capacidad colocadas sobre un material reflejante. Las botellas son menos eficientes que las bolsas, pero permiten un mejor control del agua tratada evitando su recontaminacion. Para aumentar la eficiencia de la desinfeccion utilizando las botellas, se disenaron y construyeron dos concentradores solares de espejos planos que permitieron disminuir el tiempo de exposicion requerido cuando se utilizan estas. Para las pruebas de desinfeccion se utilizo agua del efluente de una planta de tratamiento

  20. Structure of the solar photosphere studied from the radiation hydrodynamics code ANTARES

    Science.gov (United States)

    Leitner, P.; Lemmerer, B.; Hanslmeier, A.; Zaqarashvili, T.; Veronig, A.; Grimm-Strele, H.; Muthsam, H. J.

    2017-09-01

    The ANTARES radiation hydrodynamics code is capable of simulating the solar granulation in detail unequaled by direct observation. We introduce a state-of-the-art numerical tool to the solar physics community and demonstrate its applicability to model the solar granulation. The code is based on the weighted essentially non-oscillatory finite volume method and by its implementation of local mesh refinement is also capable of simulating turbulent fluids. While the ANTARES code already provides promising insights into small-scale dynamical processes occurring in the quiet-Sun photosphere, it will soon be capable of modeling the latter in the scope of radiation magnetohydrodynamics. In this first preliminary study we focus on the vertical photospheric stratification by examining a 3-D model photosphere with an evolution time much larger than the dynamical timescales of the solar granulation and of particular large horizontal extent corresponding to 25''×25'' on the solar surface to smooth out horizontal spatial inhomogeneities separately for up- and downflows. The highly resolved Cartesian grid thereby covers ˜4 Mm of the upper convection zone and the adjacent photosphere. Correlation analysis, both local and two-point, provides a suitable means to probe the photospheric structure and thereby to identify several layers of characteristic dynamics: The thermal convection zone is found to reach some ten kilometers above the solar surface, while convectively overshooting gas penetrates even higher into the low photosphere. An ≈145 km wide transition layer separates the convective from the oscillatory layers in the higher photosphere.

  1. A hybrid numerical prediction scheme for solar radiation estimation in un-gauged catchments.

    Science.gov (United States)

    Shamim, M. A.; Bray, M.; Ishak, A. M.; Remesan, R.; Han, D.

    2009-09-01

    Gamma Test (GT). GT is a newly developed algorithm (Koncar, 1997; Agalbjorn, et al.1997) that helps in estimating the best mean squared error (MSE), for a given combination of inputs when modelling an unseen data. The study also explores the ability of GT to determine the optimum data length and optimum number of nearest neighbours for nonlinear modelling of global solar radiation in un-gauged catchments. Artificial neural networks (ANN) and Local linear regression based nonlinear models have been used to test the proposed methodology and the results have shown a high degree of correlation between the observed and estimated solar radiation data. It is believed that this study will initiate further exploration of GT for improving informed data and model selection. References Badescu V., (2008), Modelling Solar radiation at the Earth's Surface, Springer-Verlag Berlin Heidelberg. Grell G. A., Dhudia J. and Stauffer D. R. (1995), A description of fifth generation Penn Stat/NCAR Mesoscale Model (MM5). In NCAR/TN-398 + STR, NCAR Technical Note. Pp. 74-76. Yang K. and Koike T. (2002) Estimating surface solar radiation from upper air humidity. Solar Energy, Vol. 7, 2. pp. 177-186. Kambezidis H. D. and Psiloglou B. E. (2008), The Meteorological Radiation Model (MRM): Advancements and Applications in Modelling solar radiation on earth's surface, Springer-Verlag Berlin Heidelberg. Končar N., (1997), Optimization methodologies for direct inverse neurocontrol. PhD thesis, Department of Computing, Imperial College of Science, Technology and Medicine, University of London. Agalbjörn S, Končar N, Jones A. J., (1997), A note on the gamm test, Neural Computing and Applications 5(1997) p-131

  2. CODE's new solar radiation pressure model for GNSS orbit determination

    Science.gov (United States)

    Arnold, D.; Meindl, M.; Beutler, G.; Dach, R.; Schaer, S.; Lutz, S.; Prange, L.; Sośnica, K.; Mervart, L.; Jäggi, A.

    2015-08-01

    The Empirical CODE Orbit Model (ECOM) of the Center for Orbit Determination in Europe (CODE), which was developed in the early 1990s, is widely used in the International GNSS Service (IGS) community. For a rather long time, spurious spectral lines are known to exist in geophysical parameters, in particular in the Earth Rotation Parameters (ERPs) and in the estimated geocenter coordinates, which could recently be attributed to the ECOM. These effects grew creepingly with the increasing influence of the GLONASS system in recent years in the CODE analysis, which is based on a rigorous combination of GPS and GLONASS since May 2003. In a first step we show that the problems associated with the ECOM are to the largest extent caused by the GLONASS, which was reaching full deployment by the end of 2011. GPS-only, GLONASS-only, and combined GPS/GLONASS solutions using the observations in the years 2009-2011 of a global network of 92 combined GPS/GLONASS receivers were analyzed for this purpose. In a second step we review direct solar radiation pressure (SRP) models for GNSS satellites. We demonstrate that only even-order short-period harmonic perturbations acting along the direction Sun-satellite occur for GPS and GLONASS satellites, and only odd-order perturbations acting along the direction perpendicular to both, the vector Sun-satellite and the spacecraft's solar panel axis. Based on this insight we assess in the third step the performance of four candidate orbit models for the future ECOM. The geocenter coordinates, the ERP differences w. r. t. the IERS 08 C04 series of ERPs, the misclosures for the midnight epochs of the daily orbital arcs, and scale parameters of Helmert transformations for station coordinates serve as quality criteria. The old and updated ECOM are validated in addition with satellite laser ranging (SLR) observations and by comparing the orbits to those of the IGS and other analysis centers. Based on all tests, we present a new extended ECOM which

  3. Solar ultraviolet radiation in a changing climate

    Science.gov (United States)

    The projected large increases in damaging ultraviolet radiation as a result of global emissions of ozone-depleting substances have been forestalled by the success of the Montreal Protocol. New challenges are now arising in relation to climate change. We highlight the complex inte...

  4. Measurement of solar ultraviolet radiation intensity type A and B in Qazvin (2013-14

    Directory of Open Access Journals (Sweden)

    SAR. Babaee

    2016-08-01

    Full Text Available Background: Solar ultraviolet radiation (UVR is considered one of the most important biological risk factors in the world. Most health damages from solar ultraviolet radiation at ground level are mainly caused by UVA and UVB spectrums. Objective: The aim of this study was to Measure the solar ultraviolet radiation intensity type A and B in Qazvin city. Methods: In this cross-sectional study, the intensity of solar ultraviolet radiation type A and B was measured in Qazvin on years of 2013-14 (during one year every monthly at three times, in the morning, afternoon and evening by using a UV Radiometer. Data were analyzed using descriptive statistics. Findings: The maximum average intensity of UVA and UVB rays during the one year with 28.36±1.88 W/m2 and 0.156±0.035 W/m2 respectively was in Tir month (June 22–July 22 and the minimum average intensity of UVA and UVB rays with 10.36±0.83 W/m2 and 0.041±0.010 W/m2 respectively was in Dai month (December 22–January 20. Conclusion: With regards to the results, it is recommended that individuals were less exposed to exposure time with direct sunshine and use appropriate protective measures such as; wear appropriate clothing, sunglasses, and sunscreen.

  5. Using Solar Radiation Pressure to Control L2 Orbits

    Science.gov (United States)

    Tene, Noam; Richon, Karen; Folta, David

    1998-01-01

    The main perturbations at the Sun-Earth Lagrange points L1 and L2 are from solar radiation pressure (SRP), the Moon and the planets. Traditional approaches to trajectory design for Lagrange-point orbits use maneuvers every few months to correct for these perturbations. The gravitational effects of the Moon and the planets are small and periodic. However, they cannot be neglected because small perturbations in the direction of the unstable eigenvector are enough to cause exponential growth within a few months. The main effect of a constant SRP is to shift the center of the orbit by a small distance. For spacecraft with large sun-shields like the Microwave Anisotropy Probe (MAP) and the Next Generation Space Telescope (NGST), the SRP effect is larger than all other perturbations and depends mostly on spacecraft attitude. Small variations in the spacecraft attitude are large enough to excite or control the exponential eigenvector. A closed-loop linear controller based on the SRP variations would eliminate one of the largest errors to the orbit and provide a continuous acceleration for use in controlling other disturbances. It is possible to design reference trajectories that account for the periodic lunar and planetary perturbations and still satisfy mission requirements. When such trajectories are used the acceleration required to control the unstable eigenvector is well within the capabilities of a continuous linear controller. Initial estimates show that by using attitude control it should be possible to minimize and even eliminate thruster maneuvers for station keeping.

  6. Coastal-inland solar radiation difference study. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Bach, W.D. Jr.; Vukovich, F.M.

    1980-04-01

    The purpose of this study was to quantify the characteristics of solar insolation in the coastal zone and to determine the effect of the sea breeze circulation on the global insolation. In order to satisfy these objectives, a six station sampling network was established in the coastal plain of southeastern North Carolina, where previous evidence has indicated that the sea breeze circulation is almost a daily occurrence from late May through October. Three sites (Sloop Point, Onslow Beach, and Cape Fear Technical Institute (CFTI)) were located near the coast (coastal sites) to assess the insolation at the coast. A site (Clinton) was located in an area seldom affected by the sea breeze (about 100 km from the coast). Two additional sites, Wallace and Ellis Airport, located between the coastal sites and the control site, were to be used to assess the transient impact of the sea breeze upon the insolation. Pyranometers were located at each site to measure the global insolation. Direct normal insolation measured by a pyrheliometer and ultraviolet radiation measured by uv radiometers were observed at the Sloop Point and Clinton sites only. Data were collected during the calendar year 1978. The results of the study indicated that the global insolation had greater variability over the network during the summer season (June, July, and August). During the summer, there was a systematicdiurnal variation of the difference in global insolation between the inland and the coastal sites.

  7. Higher plant acclimation to solar ultraviolet-B radiation

    International Nuclear Information System (INIS)

    Robberecht, R.

    1981-01-01

    The objectives of this study were to determine: (1) the relationship between plant sensitivity and epidermal uv attenuation, (2) the effect of phenotypic changes in the leaf epidermis, resulting from uv-B exposure, on plant sensitivity to uv radiation, and (3) the platicity of these changes in the epidermis leading to plant acclimation to uv-B radiation. A mechanism of uv-B attenuation, possibly involving the biosynthesis of uv-absorbing flavonoid compounds in the epidermis and mesophyll under the stress of uv-B radiation, and a subsequent increase in the uv-B attenuation capacity of the epidermis, is suggested. The degree of plant sensitivity and acclimation to natural and intensified solar uv-B radiation may involve a dynamic balance between the capacity for uv-B attenuation and uv-radiation-repair mechanisms in the leaf

  8. Diffuse solar radiation estimation models for Turkey's big cities

    International Nuclear Information System (INIS)

    Ulgen, Koray; Hepbasli, Arif

    2009-01-01

    A reasonably accurate knowledge of the availability of the solar resource at any place is required by solar engineers, architects, agriculturists, and hydrologists in many applications of solar energy such as solar furnaces, concentrating collectors, and interior illumination of buildings. For this purpose, in the past, various empirical models (or correlations) have been developed in order to estimate the solar radiation around the world. This study deals with diffuse solar radiation estimation models along with statistical test methods used to statistically evaluate their performance. Models used to predict monthly average daily values of diffuse solar radiation are classified in four groups as follows: (i) From the diffuse fraction or cloudness index, function of the clearness index, (ii) From the diffuse fraction or cloudness index, function of the relative sunshine duration or sunshine fraction, (iii) From the diffuse coefficient, function of the clearness index, and (iv) From the diffuse coefficient, function of the relative sunshine duration or sunshine fraction. Empirical correlations are also developed to establish a relationship between the monthly average daily diffuse fraction or cloudness index (K d ) and monthly average daily diffuse coefficient (K dd ) with the monthly average daily clearness index (K T ) and monthly average daily sunshine fraction (S/S o ) for the three big cities by population in Turkey (Istanbul, Ankara and Izmir). Although the global solar radiation on a horizontal surface and sunshine duration has been measured by the Turkish State Meteorological Service (STMS) over all country since 1964, the diffuse solar radiation has not been measured. The eight new models for estimating the monthly average daily diffuse solar radiation on a horizontal surface in three big cites are validated, and thus, the most accurate model is selected for guiding future projects. The new models are then compared with the 32 models available in the

  9. UV Irradiance Enhancements by Scattering of Solar Radiation from Clouds

    Directory of Open Access Journals (Sweden)

    Uwe Feister

    2015-08-01

    Full Text Available Scattering of solar radiation by clouds can reduce or enhance solar global irradiance compared to cloudless-sky irradiance at the Earth’s surface. Cloud effects to global irradiance can be described by Cloud Modification Factors (CMF. Depending on strength and duration, irradiance enhancements affect the energy balance of the surface and gain of solar power for electric energy generation. In the ultraviolet region, they increase the risk for damage to living organisms. Wavelength-dependent CMFs have been shown to reach 1.5 even in the UV-B region at low altitudes. Ground-based solar radiation measurements in the high Andes region at altitudes up to 5917 m a.s.l showed cloud-induced irradiance enhancements. While UV-A enhancements were explained by cloud scattering, both radiation scattering from clouds and Negative Ozone Anomalies (NOA have been discussed to have caused short-time enhancement of UV-B irradiance. Based on scenarios using published CMF and additional spectroradiometric measurements at a low-altitude site, the contribution of cloud scattering to the UV-B irradiance enhancement in the Andes region has been estimated. The range of UV index estimates converted from measured UV-B and UV-A irradiance and modeled cloudless-sky ratios UV-B/erythemal UV is compatible with an earlier estimate of an extreme UV index value of 43 derived for the high Andes.

  10. Anode catalysts for direct ethanol fuel cells utilizing directly solar light illumination.

    Science.gov (United States)

    Chu, Daobao; Wang, Shuxi; Zheng, Peng; Wang, Jian; Zha, Longwu; Hou, Yuanyuan; He, Jianguo; Xiao, Ying; Lin, Huashui; Tian, Zhaowu

    2009-01-01

    Shine a light: A PtNiRu/TiO(2) anode catalyst for direct ethanol fuel cells shows photocatalytic activity. The peak current density for ethanol oxidation under solar light illumination is 2-3 times greater than that in the absence of solar light. Ethanol is oxidized by light-generated holes, and the electrons are collected by the TiO(2) support to generate the oxidation current.Novel PtNiRu/TiO(2) anode catalysts for direct ethanol fuel cells (DEFCs) were prepared from PtNiRu nanoparticles (1:1:1 atomic ratios) and a nanoporous TiO(2) film by a sol-gel and electrodeposition method. The performances of the catalysts for ethanol oxidation were investigated by cyclic voltammetry, chronoamperometry and electrochemical impedance spectroscopy. The results indicate a remarkable enhancement of activity for ethanol oxidation under solar light illumination. Under solar light illumination, the generated oxidation peak current density is 24.6 mA cm(-2), which is about 2.5 times higher than that observed without solar light (9.9 mA cm(-2)). The high catalytic activity of the PtNiRu/TiO(2) complex catalyst for the electrooxidation of ethanol may be attributed to the modified metal/nanoporous TiO(2) film, and the enhanced electrooxidation of ethanol under solar light may be due to the photogeneration of holes in the modified nanoporous TiO(2) film.

  11. Modelling of aircrew radiation exposure during solar particle events

    Science.gov (United States)

    Al Anid, Hani Khaled

    In 1990, the International Commission on Radiological Protection recognized the occupational exposure of aircrew to cosmic radiation. In Canada, a Commercial and Business Aviation Advisory Circular was issued by Transport Canada suggesting that action should be taken to manage such exposure. In anticipation of possible regulations on exposure of Canadian-based aircrew in the near future, an extensive study was carried out at the Royal Military College of Canada to measure the radiation exposure during commercial flights. The radiation exposure to aircrew is a result of a complex mixed-radiation field resulting from Galactic Cosmic Rays (GCRs) and Solar Energetic Particles (SEPs). Supernova explosions and active galactic nuclei are responsible for GCRs which consist of 90% protons, 9% alpha particles, and 1% heavy nuclei. While they have a fairly constant fluence rate, their interaction with the magnetic field of the Earth varies throughout the solar cycles, which has a period of approximately 11 years. SEPs are highly sporadic events that are associated with solar flares and coronal mass ejections. This type of exposure may be of concern to certain aircrew members, such as pregnant flight crew, for which the annual effective dose is limited to 1 mSv over the remainder of the pregnancy. The composition of SEPs is very similar to GCRs, in that they consist of mostly protons, some alpha particles and a few heavy nuclei, but with a softer energy spectrum. An additional factor when analysing SEPs is the effect of flare anisotropy. This refers to the way charged particles are transported through the Earth's magnetosphere in an anisotropic fashion. Solar flares that are fairly isotropic produce a uniform radiation exposure for areas that have similar geomagnetic shielding, while highly anisotropic events produce variable exposures at different locations on the Earth. Studies of neutron monitor count rates from detectors sharing similar geomagnetic shielding properties

  12. Radiative equilibrium in solar prominences reconsidered

    Czech Academy of Sciences Publication Activity Database

    Heinzel, Petr; Anzer, U.

    2012-01-01

    Roč. 539, March (2012), A49/1-A49/6 ISSN 0004-6361 R&D Projects: GA ČR GA205/09/1705; GA ČR GAP209/10/1680 Institutional research plan: CEZ:AV0Z10030501 Keywords : Sun * radiative transfer Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics Impact factor: 5.084, year: 2012

  13. Shaded Spacecraft Radiators to Be Used on the Daytime Surface of the Mercury Planet, the Moon, and Asteroids of the Solar System Inner Part

    Directory of Open Access Journals (Sweden)

    V. A. Igrickii

    2016-01-01

    Full Text Available During the daytime a surface of the Moon, Mercury planet, and asteroids of the Solar system inner part, significantly heats up, and infrared radiation of the local soil becomes essential. At the same time direct solar radiation and reflected from the surface solar radiation reach the maximum too. These radiation fluxes can significantly decrease the efficiency of spacecraft radiators in the daytime. This effect is especially strong on the Mercury surface where direct solar radiation is 10 times stronger than solar radiation near the Earth. As a result, on the daytime surface of the Mercury the conventional low-temperature radiators become completely disabled.The article describes the development of the special shaded spacecraft radiators to be used in daytime on the Mercury and other atmosphereless bodies of the Solar system inner part. To solve this task are used mirror shades. The shape of these shades is developed to improve operation conditions of the spacecraft radiator through the appropriate scheme of radiation reflection. The task is discussed in 2D and 3D cases. A new design of shaded spacecraft radiators is proposed, and reasonable proportions of radiators are determined. The performance capability of proposed radiators for environments of the Mercury and the Moon is estimated using the zonal method in view of partial mirror reflection. The calculations showed that the developed shaded spacecraft radiators are capable to work on the Mercury surface as the low-temperature radiators even during the daytime. New radiators provide minimum accepted operating temperature of 241К (-32°С, meanwhile radiators of common design have minimum operating temperature of 479К (206°С. Using such radiators on the Moon enables us to increase effectiveness of spacecraft radiators and to decrease their minimum operating temperature from 270К (-3°С to 137К (-136°С.

  14. Concentrator photovoltaic module architectures with capabilities for capture and conversion of full global solar radiation

    KAUST Repository

    Lee, Kyu Tae

    2016-12-06

    Emerging classes ofconcentrator photovoltaic (CPV) modules reach efficiencies that are far greater than those of even the highest performance flat-plate PV technologies, with architectures that have the potential to provide the lowest cost of energy in locations with high direct normal irradiance (DNI). A disadvantage is their inability to effectively use diffuse sunlight, thereby constraining widespread geographic deployment and limiting performance even under the most favorable DNI conditions. This study introduces a module design that integrates capabilities in flat-plate PV directly with the most sophisticated CPV technologies, for capture of both direct and diffuse sunlight, thereby achieving efficiency in PV conversion of the global solar radiation. Specific examples of this scheme exploit commodity silicon (Si) cells integrated with two different CPV module designs, where they capture light that is not efficiently directed by the concentrator optics onto large-scale arrays of miniature multijunction (MJ) solar cells that use advanced III-V semiconductor technologies. In this CPV scheme (

  15. Concentrator photovoltaic module architectures with capabilities for capture and conversion of full global solar radiation

    KAUST Repository

    Lee, Kyu Tae; Yao, Yuan; He, Junwen; Fisher, Brent; Sheng, Xing; Lumb, Matthew; Xu, Lu; Anderson, Mikayla A.; Scheiman, David; Han, Seungyong; Kang, Yongseon; Gumus, Abdurrahman; Bahabry, Rabab R.; Lee, Jung Woo; Paik, Ungyu; Bronstein, Noah D.; Alivisatos, A. Paul; Meitl, Matthew; Burroughs, Scott; Hussain, Muhammad Mustafa; Lee, Jeong Chul; Nuzzo, Ralph G.; Rogers, John A.

    2016-01-01

    Emerging classes ofconcentrator photovoltaic (CPV) modules reach efficiencies that are far greater than those of even the highest performance flat-plate PV technologies, with architectures that have the potential to provide the lowest cost of energy in locations with high direct normal irradiance (DNI). A disadvantage is their inability to effectively use diffuse sunlight, thereby constraining widespread geographic deployment and limiting performance even under the most favorable DNI conditions. This study introduces a module design that integrates capabilities in flat-plate PV directly with the most sophisticated CPV technologies, for capture of both direct and diffuse sunlight, thereby achieving efficiency in PV conversion of the global solar radiation. Specific examples of this scheme exploit commodity silicon (Si) cells integrated with two different CPV module designs, where they capture light that is not efficiently directed by the concentrator optics onto large-scale arrays of miniature multijunction (MJ) solar cells that use advanced III-V semiconductor technologies. In this CPV scheme (

  16. Radiation Testing of PICA at the Solar Power Tower

    Science.gov (United States)

    White, Susan

    2010-01-01

    Sandia National Laboratory's Solar Power Tower was used to irradiate specimens of Phenolic Impregnated Carbon Ablator (PICA), in order to evaluate whether this thermal protection system material responded differently to potential shock layer radiative heating than to convective heating. Tests were run at 50, 100 and 150 Watts per square centimeter levels of concentrated solar radiation. Experimental results are presented both from spectral measurements on 1- 10 mm thick specimens of PICA, as well as from in-depth temperature measurements on instrumented thicker test specimens. Both spectral measurements and measured in-depth temperature profiles showed that, although it is a porous, low-density material, PICA does not exhibit problematic transparency to the tested high levels of NIR radiation, for all pragmatic cm-to-inch scale thicknesses. PICA acted as a surface absorber to efficiently absorb the incident visible and near infrared incident radiation in the top 2 millimeter layer in the Solar Power Tower tests up to 150 Watts per square centimeter.

  17. Importance of atmospheric turbidity and associated uncertainties in solar radiation and luminous efficacy modelling

    International Nuclear Information System (INIS)

    Gueymard, Christian A.

    2005-01-01

    For many solar-related applications, it is important to separately predict the direct and diffuse components of irradiance or illuminance. Under clear skies, turbidity plays a determinant role in quantitatively affecting these components. In this paper, various aspects of the effect of turbidity on both spectral and broadband radiation are addressed, as well as the uncertainty in irradiance predictions due to inaccurate turbidity data, and the current improvements in obtaining the necessary turbidity data

  18. Assessment Of The Viability Of Kaduna City Climate For Year Round Use Of Direct Solar Thermal Cooking Fuel In Housing

    Directory of Open Access Journals (Sweden)

    Boumann Ephraim Sule

    2017-10-01

    Full Text Available Solar energy obtained from the sun is the world most abundant and cheapest source of energy as a cooking fuel. It comes in two forms Concentrated Solar Thermal direct conversion of solar energy to heat that cooks and Solar Photovoltaic PV a conversion of solar energy to electrical then to heat energy the former technology is simple and far cheaper. Despite all these architectural and engineering researches is yet to capture it for indoor cooking because of inability to cook year round due the claimed hindrances by weather condition such as clouds rainfall wind dusty atmosphere and many others. This paper attempted to look into the possibility of cooking year round in Kaduna city. It collected and analyzed ten years climatic data from three different meteorological stations strategically located round the city this showed a low solar radiation in the month of August. It further compared the result with a literature review of solar cooking carried in the same month the findings showed at the peak of each weather hindrance a another element overrides it to give enough minimum energy for cooking a meals. This paper has therefore pointed the potentials of Kaduna city climate for year round use of concentrated solar thermal as a cooking fuel in residential building and further recommends the architectural collaboration with engineers for the direct capturing of solar rays into residential dwelling as a sustainable cooking fuel.

  19. Solar Irradiance Changes And Photobiological Effects At Earth's Surface Following Astrophysical Ionizing Radiation Events

    Science.gov (United States)

    Thomas, Brian; Neale, Patrick

    2016-01-01

    Astrophysical ionizing radiation events have been recognized as a potential threat to life on Earth for decades. Although there is some direct biological damage on the surface from redistributed radiation several studies have indicated that the greatest long term threat is from ozone depletion and subsequent heightened solar ultraviolet (UV) radiation. It is known that organisms exposed to this irradiation experience harmful effects such as sunburn and even direct damage to DNA, proteins, or other cellular structures. Simulations of the atmospheric effects of a variety of events (such as supernovae, gamma-ray bursts, and solar proton events) have been previously published, along with estimates of biological damage at Earth's surface. In the present work, we employed a radiative transfer model to expand and improve calculations of surface-level irradiance and biological impacts following an ionizing radiation event. We considered changes in surface-level UVB, UVA, and photosynthetically active radiation (visible light). Using biological weighting functions we have considered a wide range of effects, including: erythema and skin cancer in humans; inhibition of photosynthesis in the diatom Phaeodactylum sp. and dinoflagellate Prorocentrum micans inhibition of carbon fixation in Antarctic phytoplankton; inhibition of growth of oat (Avena sativa L. cv. Otana) seedlings; and cataracts. We found that past work overestimated UVB irradiance, but that relative estimates for increase in exposure to DNA damaging radiation are still similar to our improved calculations. We also found that the intensity of biologically damaging radiation varies widely with organism and specific impact considered; these results have implications for biosphere-level damage following astrophysical ionizing radiation events. When considering changes in surface-level visible light irradiance, we found that, contrary to previous assumptions, a decrease in irradiance is only present for a short time in

  20. Modeling Solar Radiation in the Forest Using Remote Sensing Data: A Review of Approaches and Opportunities

    Directory of Open Access Journals (Sweden)

    Alex S. Olpenda

    2018-05-01

    Full Text Available Solar radiation, the radiant energy from the sun, is a driving variable for numerous ecological, physiological, and other life-sustaining processes in the environment. Traditional methods to quantify solar radiation are done either directly (e.g., quantum sensors, or indirectly (e.g., hemispherical photography. This study, however, evaluates literature which utilized remote sensing (RS technologies to estimate various forms of solar radiation or components, thereof under or within forest canopies. Based on the review, light detection and ranging (LiDAR has, so far, been preferably used for modeling light under tree canopies. Laser system’s capability of generating 3D canopy structure at high spatial resolution makes it a reasonable choice as a source of spatial information about light condition in various parts of forest ecosystem. The majority of those using airborne laser system (ALS commonly adopted the volumetric-pixel (voxel method or the laser penetration index (LPI for modeling the radiation, while terrestrial laser system (TLS is preferred for canopy reconstruction and simulation. Furthermore, most of the studies focused only on global radiation, and very few on the diffuse fraction. It was also found out that most of these analyses were performed in the temperate zone, with a smaller number of studies made in tropical areas. Nonetheless, with the continuous advancement of technology and the RS datasets becoming more accessible and less expensive, these shortcomings and other difficulties of estimating the spatial variation of light in the forest are expected to diminish.

  1. Photochemical degradation of the carbapenem antibiotics imipenem and meropenem in aqueous solutions under solar radiation.

    Science.gov (United States)

    Reina, Alejandro Cabrera; Martínez-Piernas, Ana B; Bertakis, Yannis; Brebou, Christina; Xekoukoulotakis, Nikolaos P; Agüera, Ana; Sánchez Pérez, José Antonio

    2018-01-01

    This paper deals with the photochemical fate of two representative carbapenem antibiotics, namely imipenem and meropenem, in aqueous solutions under solar radiation. The analytical method employed for the determination of the target compounds in various aqueous matrices, such as ultrapure water, municipal wastewater treatment plant effluents, and river water, at environmentally relevant concentrations, was liquid chromatography coupled with hybrid triple quadrupole-linear ion trap-mass spectrometry. The absorption spectra of both compounds were measured in aqueous solutions at pH values from 6 to 8, and both compounds showed a rather strong absorption band centered at about 300 nm, while their molar absorption coefficient was in the order from 9 × 10 3 -10 4  L mol -1  cm -1 . The kinetics of the photochemical degradation of the target compounds was studied in aqueous solutions under natural solar radiation in a solar reactor with compound parabolic collectors. It was found that the photochemical degradation of both compounds at environmentally relevant concentrations follows first order kinetics and the quantum yield was in the order of 10 -3  mol einsten -1 . Several parameters were studied, such as solution pH, the presence of nitrate ions and humic acids, and the effect of water matrix. In all cases, it was found that the presence of various organic and inorganic constituents in the aqueous matrices do not contribute significantly, either positively or negatively, to the photochemical degradation of both compounds under natural solar radiation. In a final set of photolysis experiments, the effect of the level of irradiance was studied under simulated solar radiation and it was found that the quantum yield for the direct photodegradation of both compounds remained practically constant by changing the incident solar irradiance from 28 to 50 W m -2 . Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. Variation of reflected radiation from all reflectors of a flat plate solar collector during a year

    International Nuclear Information System (INIS)

    Pavlović, Zoran T.; Kostić, Ljiljana T.

    2015-01-01

    In this paper the impact of flat plate reflectors (bottom, top, left and right reflectors) made of Al, on total solar radiation on a solar collector during a day time over a whole year is analyzed. An analytical model for determining optimum tilt angles of a collector and reflectors for any point on the Earth is proposed. Variations of reflectors' optimal inclination angles with changes of the collector's optimal tilt angle during the year are also calculated. Optimal inclination angles of the reflectors for the South directed solar collector are calculated and compared to experimental data. It is shown that optimal inclination of the bottom reflector is the lowest in December and the highest in June, while for the top reflector the lowest value is in June and the highest value is in December. On the other hand, optimal inclination of the left and right side reflectors for optimum tilt angle of the collector does not change during the year and it is 66°. It is found that intensity of the solar radiation on the collector increases for about 80% in the summer period (June–September) by using optimally inclined reflectors, in comparison to the collector without reflectors. - Highlights: • The impacts of flat plate reflectors on solar radiation on the collector are given. • The results of the optimal inclinations of reflectors during the year are shown. • The solar radiation on the collector with reflectors is 80% higher in the summer. • This model may be applied on thermal, PV, PV/T and energy harvesting systems

  3. Nanofluid optical property characterization: towards efficient direct absorption solar collectors

    Directory of Open Access Journals (Sweden)

    Otanicar Todd

    2011-01-01

    Full Text Available Abstract Suspensions of nanoparticles (i.e., particles with diameters < 100 nm in liquids, termed nanofluids, show remarkable thermal and optical property changes from the base liquid at low particle loadings. Recent studies also indicate that selected nanofluids may improve the efficiency of direct absorption solar thermal collectors. To determine the effectiveness of nanofluids in solar applications, their ability to convert light energy to thermal energy must be known. That is, their absorption of the solar spectrum must be established. Accordingly, this study compares model predictions to spectroscopic measurements of extinction coefficients over wavelengths that are important for solar energy (0.25 to 2.5 μm. A simple addition of the base fluid and nanoparticle extinction coefficients is applied as an approximation of the effective nanofluid extinction coefficient. Comparisons with measured extinction coefficients reveal that the approximation works well with water-based nanofluids containing graphite nanoparticles but less well with metallic nanoparticles and/or oil-based fluids. For the materials used in this study, over 95% of incoming sunlight can be absorbed (in a nanofluid thickness ≥10 cm with extremely low nanoparticle volume fractions - less than 1 × 10-5, or 10 parts per million. Thus, nanofluids could be used to absorb sunlight with a negligible amount of viscosity and/or density (read: pumping power increase.

  4. Magnetosheath Propagation Time of Solar Wind Directional Discontinuities

    Science.gov (United States)

    Samsonov, A. A.; Sibeck, D. G.; Dmitrieva, N. P.; Semenov, V. S.; Slivka, K. Yu.; Å afránkova, J.; Němeček, Z.

    2018-05-01

    Observed delays in the ground response to solar wind directional discontinuities have been explained as the result of larger than expected magnetosheath propagation times. Recently, Samsonov et al. (2017, https://doi.org/10.1002/2017GL075020) showed that the typical time for a southward interplanetary magnetic field (IMF) turning to propagate across the magnetosheath is 14 min. Here by using a combination of magnetohydrodynamic simulations, spacecraft observations, and analytic calculations, we study the dependence of the propagation time on solar wind parameters and near-magnetopause cutoff speed. Increases in the solar wind speed result in greater magnetosheath plasma flow velocities, decreases in the magnetosheath thickness and, as a result, decreases in the propagation time. Increases in the IMF strength result in increases in the magnetosheath thickness and increases in the propagation time. Both magnetohydrodynamic simulations and observations suggest that propagation times are slightly smaller for northward IMF turnings. Magnetosheath flow deceleration must be taken into account when predicting the arrival times of solar wind structures at the dayside magnetopause.

  5. Neural network based method for conversion of solar radiation data

    International Nuclear Information System (INIS)

    Celik, Ali N.; Muneer, Tariq

    2013-01-01

    Highlights: ► Generalized regression neural network is used to predict the solar radiation on tilted surfaces. ► The above network, amongst many such as multilayer perceptron, is the most successful one. ► The present neural network returns a relative mean absolute error value of 9.1%. ► The present model leads to a mean absolute error value of estimate of 14.9 Wh/m 2 . - Abstract: The receiving ends of the solar energy conversion systems that generate heat or electricity from radiation is usually tilted at an optimum angle to increase the solar incident on the surface. Solar irradiation data measured on horizontal surfaces is readily available for many locations where such solar energy conversion systems are installed. Various equations have been developed to convert solar irradiation data measured on horizontal surface to that on tilted one. These equations constitute the conventional approach. In this article, an alternative approach, generalized regression type of neural network, is used to predict the solar irradiation on tilted surfaces, using the minimum number of variables involved in the physical process, namely the global solar irradiation on horizontal surface, declination and hour angles. Artificial neural networks have been successfully used in recent years for optimization, prediction and modeling in energy systems as alternative to conventional modeling approaches. To show the merit of the presently developed neural network, the solar irradiation data predicted from the novel model was compared to that from the conventional approach (isotropic and anisotropic models), with strict reference to the irradiation data measured in the same location. The present neural network model was found to provide closer solar irradiation values to the measured than the conventional approach, with a mean absolute error value of 14.9 Wh/m 2 . The other statistical values of coefficient of determination and relative mean absolute error also indicate the

  6. 3D LOCAL SCALE SOLAR RADIATION MODEL BASED ON URBAN LIDAR DATA

    Directory of Open Access Journals (Sweden)

    P. M. Redweik

    2012-09-01

    Full Text Available The aim of the present study is to obtain the direct, diffuse and reflected solar energy that reaches a generic point of an urban landscape regardless of its location on a roof, on the ground or on a façade. The vertical façades embody a discontinuity in a digital elevation surface function and most models fail in the determination of solar radiation for points on façades. The presented algorithm solves the problem in an integrated way: starting with a georreferenced LIDAR data cloud covering a 400 × 400 m2 urban area resampled in a 1m × 1m mesh, applies a new shadow algorithm over roofs, terrain and façades for each time frame, applies the Kumar solar radiation model for the calculation of direct, diffuse and reflected irradiation for each 1x1m raster cell on non vertical surfaces of roof and terrain, and calculates total and mean irradiation of each 1 meter wide column of vertical façade based on the illuminated area at each time frame. The results for each time frame are integrated for the wished time period from one hour to one year, being the time steps also selectable, allowing several kinds of solar radiation and shadowing studies. GIS were used to evaluate monthly averages of solar radiation for a particular location as well as to map the photovoltaic potential of the building façades and their roofs according to determined classes of potential.

  7. Building global and diffuse solar radiation series and assessing decadal trends in Girona (NE Iberian Peninsula)

    Science.gov (United States)

    Calbó, Josep; González, Josep-Abel; Sanchez-Lorenzo, Arturo

    2017-08-01

    Measurement of solar radiation was initiated in Girona, northeast of the Iberian Peninsula, in the late 1980s. Initially, two pyranometers were installed, one of them equipped with a shadowband for measuring the diffuse component. Two other pyranometers currently exist, both ventilated and one of them shadowed, with a sphere, and a pyrheliometer for measuring direct radiation. Additional instruments for other shortwave and longwave components, clouds, and atmospheric aerosols have been installed in recent years. The station is subject to daily inspection, data are saved at high temporal resolution, and instruments are periodically calibrated, all in accordance with the directions of the Baseline Surface Radiation Network. The present paper describes how the entire series of global solar radiation (1987-2014) and diffuse radiation (1994-2014) were built, including the quality control process. Appropriate corrections to the diffuse component were made when a shadowband was employed to make measurements. Analysis of the series reveals that annual mean global irradiance presents a statistically significant increase of 2.5 W m-2 (1.4 %) decade-1 (1988-2014 period), mainly due to what occurs in summer (5.6 W m-2 decade-1). These results constitute the first assessment of solar radiation trends for the northeastern region of the Iberian Peninsula and are consistent with trends observed in the regional surroundings and also by satellite platforms, in agreement with the global brightening phenomenon. Diffuse radiation has decreased at -1.3 W m-2 (-2 %) decade-1 (1994-2014 period), which is a further indication of the reduced cloudiness and/or aerosol load causing the changes.

  8. Evaluation of the National Solar Radiation Database (NSRDB) Using Ground-Based Measurements

    Science.gov (United States)

    Xie, Y.; Sengupta, M.; Habte, A.; Lopez, A.

    2017-12-01

    Solar resource is essential for a wide spectrum of applications including renewable energy, climate studies, and solar forecasting. Solar resource information can be obtained from ground-based measurement stations and/or from modeled data sets. While measurements provide data for the development and validation of solar resource models and other applications modeled data expands the ability to address the needs for increased accuracy and spatial and temporal resolution. The National Renewable Energy Laboratory (NREL) has developed and regular updates modeled solar resource through the National Solar Radiation Database (NSRDB). The recent NSRDB dataset was developed using the physics-based Physical Solar Model (PSM) and provides gridded solar irradiance (global horizontal irradiance (GHI), direct normal irradiance (DNI), and diffuse horizontal irradiance) at a 4-km by 4-km spatial and half-hourly temporal resolution covering 18 years from 1998-2015. A comprehensive validation of the performance of the NSRDB (1998-2015) was conducted to quantify the accuracy of the spatial and temporal variability of the solar radiation data. Further, the study assessed the ability of NSRDB (1998-2015) to accurately capture inter-annual variability, which is essential information for solar energy conversion projects and grid integration studies. Comparisons of the NSRDB (1998-2015) with nine selected ground-measured data were conducted under both clear- and cloudy-sky conditions. These locations provide a high quality data covering a variety of geographical locations and climates. The comparison of the NSRDB to the ground-based data demonstrated that biases were within +/- 5% for GHI and +/-10% for DNI. A comprehensive uncertainty estimation methodology was established to analyze the performance of the gridded NSRDB and includes all sources of uncertainty at various time-averaged periods, a method that is not often used in model evaluation. Further, the study analyzed the inter

  9. Long-term visual health risks from solar ultraviolet radiation

    International Nuclear Information System (INIS)

    Waxler, M.

    1987-01-01

    Ocular exposure to the ultraviolet radiation (UV) contained in sunlight may result in long-term visual health problems. UV plays a role in the etiology of cataracts and possibly in the etiology of visual impairments associated with solar retinopathy, retinopathy of prematurity, ocular aging, cystoid macular edema, retinitis pigmentosa, and senile macular degeneration. The exact does relationships between known UV bioeffects and these ocular problems is, however, uncertain. Thus, there are questions about the extent to which protective measures should be taken to reduce UV exposure of the eye. This paper identifies the long-term visual health problems potentially associated with ocular exposure to solar UV; proposes worst-case assumptions for the role of solar UV in these visual problems; and recommends protective measures based on damage thresholds and worst-case assumptions

  10. Effects of stratospheric perturbations on the solar radiation budget

    International Nuclear Information System (INIS)

    Luther, F.M.

    1978-04-01

    The changes in solar absorption and in local heating rates due to perturbations to O 3 and NO 2 concentrations caused by stratospheric injection of NO/sub x/ and CFM pollutants are assessed. The changes in species concentration profiles are derived from theoretical calculations using a transport-kinetics model. Because of significant changes in our understanding of stratospheric chemistry during the past year, the assessment of the effect of stratospheric perturbations on the solar radiation budget differs from previous assessments. Previously, a reduction in O 3 due to an NO/sub x/ injection caused a net decrease in the gaseous solar absorption;now the same perturbation leads to a net increase. The implication of these changes on the surface temperature is also discussed

  11. Solar radiation and out-of-hospital cardiac arrest in Japan.

    Science.gov (United States)

    Onozuka, Daisuke; Hagihara, Akihito

    2017-11-01

    Although several studies have estimated the effects of temperature on mortality and morbidity, little is known regarding the burden of out-of-hospital cardiac arrest (OHCA) attributable to solar radiation. We obtained data for all cases of OHCA and meteorological data reported between 2011 and 2014 in 3 Japanese prefectures: Hokkaido, Ibaraki, and Fukuoka. We first examined the relationship between daily solar radiation and OHCA risk for each prefecture using time-varying distributed lag non-linear models and then pooled the results in a multivariate random-effects meta-analysis. The attributable fractions of OHCA were calculated for low and high solar radiation, defined as solar radiation below and above the minimum morbidity solar radiation, respectively. The minimum morbidity solar radiation was defined as the specific solar radiation associated with the lowest morbidity risk. A total of 49,892 cases of OHCA occurred during the study period. The minimum morbidity solar radiation for each prefecture was the 100th percentile (72.5 MJ/m 2 ) in Hokkaido, the 83rd percentile (59.7 MJ/m 2 ) in Ibaraki, and the 70th percentile (53.8 MJ/m 2 ) in Fukuoka. Overall, 20.00% (95% empirical confidence interval [eCI]: 10.97-27.04) of the OHCA cases were attributable to daily solar radiation. The attributable fraction for low solar radiation was 19.50% (95% eCI: 10.00-26.92), whereas that for high solar radiation was 0.50% (95% eCI: -0.07-1.01). Low solar radiation was associated with a substantial attributable risk for OHCA. Our findings suggest that public health efforts to reduce OHCA burden should consider the solar radiation level. Large prospective studies with longitudinal collection of individual data is required to more conclusively assess the impact of solar radiation on OHCA. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. Solar ultraviolet radiation response of EBT2 Gafchromic, radiochromic film

    International Nuclear Information System (INIS)

    Butson, Ethan T; Yu, Peter K N; Butson, Martin J

    2013-01-01

    Measurement of solar ultraviolet (UV) radiation is an important aspect of dosimetry for the improved knowledge of UV exposure and its associated health related issues. EBT2 Gafchromic film has been designed by its manufacturers as an improved tool for ionizing radiation dosimetry. The film is stated as exhibiting a significant reduction in UV response. However, results have shown that when exposed to UV from the ‘bottom side’ i.e. from the thick laminate side, the film exhibits a sensitivity to solar UV radiation which is both measurable and accurate for UV dosimetry. Films were irradiated in this position to known solar UV exposures and results are quantified showing a reproducibility of measurement to within ±7% (1 SD) when compared to calibrated UV meters. With an exposure of 20 J cm −2 broad spectrum solar UV, the films net OD change was found to be 0.248 OD ± 0.021 OD when analysing the results using the red channel region of an Epson V700 desktop scanner. This was compared to 0.0294 OD ± 0.0053 OD change with exposure to the same UV exposure from the top side. This means that solar UV dosimetry can be performed using EBT2 Gafchromic film utilizing the underside of the film for dosimetry. The main advantages of this film type for measurement of UV exposure is the visible colour change and thus easy analysis using a desktop scanner as well as its uniformity in response and its robust physical strength for use in outside exposure situations. (note)

  13. Spectral variation of the solar radiation during an eclipse

    Directory of Open Access Journals (Sweden)

    Peter Koepke

    2001-05-01

    Full Text Available The time dependent variation of the spectral extraterrestrial solar flux is modelled for the conditions during a total eclipse. These data are used to calculate irradiance and actinic flux at the Earth’s surface for atmospheric conditions of August 11, 1999 at Weihenstephan. These results are compared with measurements. It is shown, that the spectral composition of solar radiation varies during the eclipse, since solar limb darkening has a spectral dependence. The solar radiation differs from that of a hypothetical sun without limb darkening by up to 30% in the near IR at 1500 nm and 60% in the UV-B at 310 nm. As shown by a comparison of modelling and measurements, this spectral variation has to be taken into account for modelling of UV radiative quantities in the atmosphere and resulting photochemical processes. The effect of broken cloudiness on irradiance and actinic flux and its dependency on wavelength and receiver geometry is explained. Der Verlauf der spektralen extraterrestrischen solaren Strahlung wÄhrend einer Sonnenfinsternis wurde berechnet. Basierend auf diesen Daten, unter BerÜcksichtigung der atmosphÄrischen Bedingungen am 11. August 1999 in Weihenstephan, wurden Globalstrahlung und Aktinischer Fluss am Boden modelliert und mit Messwerten verglichen. Die spektrale Zusammensetzung der Strahlung Ändert sich wÄhrend einer Sonnenfinsternis, bedingt durch die wellenlÄngenabhÄngige Randverdunklung der Sonne. Im Vergleich zu einer hypothetischen Sonne ohne Randverdunklung ist die solare Strahlung im nahen IR um bis zu 30% gemindert und im UVB bei 310 nm um bis zu 60%. Diese spektralen Änderungen sollten bei der Modellierung von Strahlung, z.B. fÜr photochemische Prozesse berÜcksichtigt werden. Dies wurde durch Messung und Modellierung gezeigt. Der Einfluss von Wolken auf gemessene Werte von Globalstrahlung und Aktinischem Fluss wurde untersucht und erklÄrt.

  14. Photoluminescence in large fluence radiation irradiated space silicon solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Hisamatsu, Tadashi; Kawasaki, Osamu; Matsuda, Sumio [National Space Development Agency of Japan, Tsukuba, Ibaraki (Japan). Tsukuba Space Center; Tsukamoto, Kazuyoshi

    1997-03-01

    Photoluminescence spectroscopy measurements were carried out for silicon 50{mu}m BSFR space solar cells irradiated with 1MeV electrons with a fluence exceeding 1 x 10{sup 16} e/cm{sup 2} and 10MeV protons with a fluence exceeding 1 x 10{sup 13} p/cm{sup 2}. The results were compared with the previous result performed in a relative low fluence region, and the radiation-induced defects which cause anomalous degradation of the cell performance in such large fluence regions were discussed. As far as we know, this is the first report which presents the PL measurement results at 4.2K of the large fluence radiation irradiated silicon solar cells. (author)

  15. CO2 and solar radiation: cause of global warming?

    International Nuclear Information System (INIS)

    Bayona Gabriel; Garcia, Yuri C.; Sarmiento Heiner R

    2010-01-01

    A cause-effect relationship between global temperature as a climatic change indicator and some of the main forcing mechanisms (Atmospheric CO 2 concentration, solar radiation and volcanic activity) are analyzed in this paper through time series analysis for the 1610-1990 AD period comparing trends and variability for the frequency spectrums. Temperature seems to fit the CO 2 trend for the last century, but we found no cause-effect relationship for this interval. The frequency analysis shows a correlation between radiation and temperature for a period of 22 years. Volcanism presents an inverse relationship with temperature better seen at a decadal scale.

  16. Variation of sodium on Mercury with solar radiation pressure

    International Nuclear Information System (INIS)

    Potter, A.E.; Morgan, T.H.

    1987-01-01

    It has been suggested that nonthermal Na atoms with velocities in excess of 2.1 km/sec in the Mercury atmosphere can be accelerated off the planet by solar radiation pressure; Na abundance may accordingly be expected to decrease with increasing radiation pressure. While this is confirmed by the present measurements, high resolution line profile measurements on Na emission indicate that very little, if any, of the Na is nonthermal, while the bulk is at a temperature approaching that of the planetary surface. Attention is given to explanations for the observed variation. 11 references

  17. Numerical model of solar dynamic radiator for parametric analysis

    Science.gov (United States)

    Rhatigan, Jennifer L.

    1989-01-01

    Growth power requirements for Space Station Freedom will be met through addition of 25 kW solar dynamic (SD) power modules. Extensive thermal and power cycle modeling capabilities have been developed which are powerful tools in Station design and analysis, but which prove cumbersome and costly for simple component preliminary design studies. In order to aid in refining the SD radiator to the mature design stage, a simple and flexible numerical model was developed. The model simulates heat transfer and fluid flow performance of the radiator and calculates area mass and impact survivability for many combinations of flow tube and panel configurations, fluid and material properties, and environmental and cycle variations.

  18. Convenient models of the atmosphere: optics and solar radiation

    Science.gov (United States)

    Alexander, Ginsburg; Victor, Frolkis; Irina, Melnikova; Sergey, Novikov; Dmitriy, Samulenkov; Maxim, Sapunov

    2017-11-01

    Simple optical models of clear and cloudy atmosphere are proposed. Four versions of atmospheric aerosols content are considered: a complete lack of aerosols in the atmosphere, low background concentration (500 cm-3), high concentrations (2000 cm-3) and very high content of particles (5000 cm-3). In a cloud scenario, the model of external mixture is assumed. The values of optical thickness and single scattering albedo for 13 wavelengths are calculated in the short wavelength range of 0.28-0.90 µm, with regard to the molecular absorption bands, that is simulated with triangle function. A comparison of the proposed optical parameters with results of various measurements and retrieval (lidar measurement, sampling, processing radiation measurements) is presented. For a cloudy atmosphere models of single-layer and two-layer atmosphere are proposed. It is found that cloud optical parameters with assuming the "external mixture" agrees with retrieved values from airborne observations. The results of calculating hemispherical fluxes of the reflected and transmitted solar radiation and the radiative divergence are obtained with the Delta-Eddington approach. The calculation is done for surface albedo values of 0, 0.5, 0.9 and for spectral values of the sandy surface. Four values of solar zenith angle: 0°, 30°, 40° and 60° are taken. The obtained values are compared with data of radiative airborne observations. Estimating the local instantaneous radiative forcing of atmospheric aerosols and clouds for considered models is presented together with the heating rate.

  19. Direct coupling of a solar-hydrogen system in Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Arriaga, L.G. [Gerencia de Energias No Convencionales, Instituto de Investigaciones Electricas (IIE), Av. Reforma 113, Col. Palmira, 62490 Cuernavaca, Morelos (Mexico); Centro de Investigacion y Desarrollo Tecnologico en Electroquimica S.C., Parque tecnologico Queretaro Sanfandila, Pedro Escobedo, C.P. 76703 Queretaro (Mexico); Martinez, W. [Departamento de Materiales Solares, CIE-UNAM, Av. Xochicalco s/n, Col. Centro, 62580 Temixco, Morelos (Mexico); Cano, U.; Blud, H. [Gerencia de Energias No Convencionales, Instituto de Investigaciones Electricas (IIE), Av. Reforma 113, Col. Palmira, 62490 Cuernavaca, Morelos (Mexico)

    2007-09-15

    The scope of this article is to show the initial results obtained in the interconnection of a 2.7 kW solar panel system with a solid polymer electrolyte (SPE) electrolyzer. The Non-Conventional Energies Department (ENC) at the Electrical Research Institute (IIE) considers that the storage of this intermittent energy by a chemical element such as hydrogen can be advantageous for certain applications. One of the arguments is that unlike traditional battery systems, hydrogen presents the great advantage of not discharging its energy content as long as it is not used. The solar-hydrogen (S-H) system proposed consists of a commercial electrolyzer stack by Proton Energy Systems and a photovoltaic (PV) solar system of 36 panels (75 W each) of monocrystalline silicon (Siemens) interconnected in a configuration for 2.7 kW power at 48V{sub DC}. The complete electrolyzer (stack plus auxiliaries) has a maximum capacity of 1000lN/h of hydrogen with a power energy consumption of 8 kVA (220V{sub AC}, 32 A) and uses a stack of 25 cells of SPE with an energy consumption of 5.6 kW. We present voltage, current and energy consumption of the electrolyzer as a whole system and of the stack alone, as well as hydrogen quantification for the Hogen 40 operating in laboratory. These results allowed us to estimate the possibilities of coupling the electrolyzer stack alone, i.e. no auxiliaries nor power conditioning, with the solar PV system. Results such as I-E curves of the solar PV system obtained at different irradiances and temperatures, as well as I-E curve of SPE electrolyzer stack, gave direction for confirming that PV system configuration was sufficiently good to have the electrolyzer stack working near the maximum power point at a good range of irradiances ({proportional_to}600-800W/m{sup 2}). (author)

  20. Overview and future direction for blackbody solar-pumped lasers

    Science.gov (United States)

    Deyoung, R. J.

    1988-01-01

    A review of solar-pumped blackbody lasers is given which addresses their present status and suggests future research directions. The blackbody laser concept is one system proposed to scale to multimegawatt power levels for space-to-space power transmissions for such applications as onboard spacecraft electrical or propulsion needs. Among the critical technical issues are the scalability to high powers and the laser wavelength which impacts the transmission optics size as well as the laser-to-electric converter at the receiver. Because present blackbody solar-pumped lasers will have laser wavelengths longer than 4 microns, simple photovoltaic converters cannot be used, and transmission optics will be large. Thus, future blackbody laser systems should emphasize near visible laser wavelengths.

  1. Starting characteristics of direct current motors powered by solar cells

    Science.gov (United States)

    Singer, S.; Appelbaum, J.

    1989-01-01

    Direct current motors are used in photovoltaic systems. Important characteristics of electric motors are the starting to rated current and torque ratios. These ratios are dictated by the size of the solar cell array and are different for the various dc motor types. Discussed here is the calculation of the starting to rated current ratio and starting to rated torque ratio of the permanent magnet, and series and shunt excited motors when powered by solar cells for two cases: with and without a maximum-power-point-tracker (MPPT) included in the system. Comparing these two cases, one gets a torque magnification of about 3 for the permanent magnet motor and about 7 for other motor types. The calculation of the torques may assist the PV system designer to determine whether or not to include an MPPT in the system.

  2. Studies on the temperature distribution of steel plates with different paints under solar radiation

    International Nuclear Information System (INIS)

    Liu, Hongbo; Chen, Zhihua; Chen, Binbin; Xiao, Xiao; Wang, Xiaodun

    2014-01-01

    Thermal effects on steel structures exposed to solar radiation are significant and complicated. Furthermore, the solar radiation absorption coefficient of steel surface with different paintings is the main factor affecting the non-uniform temperature of spatial structures under solar radiation. In this paper, nearly two hundreds steel specimens with different paintings were designed and measured to obtain their solar radiation absorption coefficients using spectrophotometer. Based on the test results, the effect of surface color, painting type, painting thickness on the solar radiation absorption coefficient was analyzed. The actual temperatures under solar radiation for all specimens were also measured in summer not only to verify the absorption coefficient but also provide insight for the temperature distribution of steel structures with different paintings. A numerical simulation and simplified formula were also conducted and verified by test, in order to study the temperature distribution of steel plates with different paints under solar radiation. The results have given an important reference in the future research of thermal effect of steel structures exposed to solar radiation. - Highlights: • Solar radiation absorptions for steel with different paintings were measured. • The temperatures of all specimens under solar radiation were measured. • The effect of color, thickness and painting type on solar absorption was analyzed. • A numerical analysis was conducted and verified by test data. • A simplified formula was deduced and verified by test data

  3. Radiation hardened high efficiency silicon space solar cell

    International Nuclear Information System (INIS)

    Garboushian, V.; Yoon, S.; Turner, J.

    1993-01-01

    A silicon solar cell with AMO 19% Beginning of Life (BOL) efficiency is reported. The cell has demonstrated equal or better radiation resistance when compared to conventional silicon space solar cells. Conventional silicon space solar cell performance is generally ∼ 14% at BOL. The Radiation Hardened High Efficiency Silicon (RHHES) cell is thinned for high specific power (watts/kilogram). The RHHES space cell provides compatibility with automatic surface mounting technology. The cells can be easily combined to provide desired power levels and voltages. The RHHES space cell is more resistant to mechanical damage due to micrometeorites. Micro-meteorites which impinge upon conventional cells can crack the cell which, in turn, may cause string failure. The RHHES, operating in the same environment, can continue to function with a similar crack. The RHHES cell allows for very efficient thermal management which is essential for space cells generating higher specific power levels. The cell eliminates the need for electrical insulation layers which would otherwise increase the thermal resistance for conventional space panels. The RHHES cell can be applied to a space concentrator panel system without abandoning any of the attributes discussed. The power handling capability of the RHHES cell is approximately five times more than conventional space concentrator solar cells

  4. Rapid and extensive warming following cessation of solar radiation management

    OpenAIRE

    McCusker, Kelly E.; Armour, Kyle; Bitz, Cecilia M.; Battisti, David S.

    2014-01-01

    Solar radiation management (SRM) has been proposed as a means to alleviate the climate impacts of ongoing anthropogenic greenhouse gas (GHG) emissions. However, its efficacy depends on its indefinite maintenance, without interruption from a variety of possible sources, such as technological failure or global cooperation breakdown. Here, we consider the scenario in which SRM—via stratospheric aerosol injection—is terminated abruptly following an implementation period during which anthropogenic...

  5. Solar Radiation Data Base for Nigeria | Chineke | Discovery and ...

    African Journals Online (AJOL)

    Solar Radiation Data Base for Nigeria. T C Chineke, J I Aina, S S Jagtap. Full Text: EMAIL FULL TEXT EMAIL FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT · http://dx.doi.org/10.4314/dai.v11i3.15556 · AJOL African Journals Online. HOW TO USE AJOL... for Researchers · for Librarians · for Authors · FAQ's ...

  6. Renewable water: Direct contact membrane distillation coupled with solar ponds

    International Nuclear Information System (INIS)

    Suárez, Francisco; Ruskowitz, Jeffrey A.; Tyler, Scott W.; Childress, Amy E.

    2015-01-01

    Highlights: • Experimental investigation of direct contact membrane distillation driven by solar ponds. • The DCMD/SGSP system treats ∼6 times the water flow treated by an AGMD/SGSP system. • Half of the energy extracted from the SGSP was used to transport water across the membrane. • Reducing heat losses through the DCMD/SGSP system would yield higher water fluxes. - Abstract: Desalination powered by renewable energy sources is an attractive solution to address the worldwide water-shortage problem without contributing significant to greenhouse gas emissions. A promising system for renewable energy desalination is the utilization of low-temperature direct contact membrane distillation (DCMD) driven by a thermal solar energy system, such as a salt-gradient solar pond (SGSP). This investigation presents the first experimental study of fresh water production in a coupled DCMD/SGSP system. The objectives of this work are to determine the experimental fresh water production rates and the energetic requirements of the different components of the system. From the laboratory results, it was found that the coupled DCMD/SGSP system treats approximately six times the water flow treated by a similar system that consisted of an air–gap membrane distillation unit driven by an SGSP. In terms of the energetic requirements, approximately 70% of the heat extracted from the SGSP was utilized to drive thermal desalination and the rest was lost in different locations of the system. In the membrane module, only half of the useful heat was actually used to transport water across the membrane and the remainder was lost by conduction in the membrane. It was also found that by reducing heat losses throughout the system would yield higher water fluxes, pointing out the need to improve the efficiency throughout the DCMD/SGSP coupled system. Therefore, further investigation of membrane properties, insulation of the system, or optimal design of the solar pond must be addressed in

  7. Infrared radiation increases skin damage induced by other wavelengths in solar urticaria.

    Science.gov (United States)

    de Gálvez, María Victoria; Aguilera, José; Sánchez-Roldán, Cristina; Herrera-Ceballos, Enrique

    2016-09-01

    Photodermatoses are typically investigated by analyzing the individual or combined effects of ultraviolet A (UVA), ultraviolet B (UVB), and visible light using light sources that simulate portions of the solar spectrum. Infrared radiation (IRR), however, accounts for 53% of incident solar radiation, but its effects are not taken into account in standard phototest protocols. The aim was to analyze the effects of IRR, alone and combined with UVA and visible light on solar urticaria lesions, with a distinction between infrared A (IRA) and infrared B (IRB). We performed standard phototests with UVA and visible light in four patients with solar urticaria and also tested the effects after blocking IRB with a water filter. To analyze the direct effect of IRR, we performed phototests with IRA and IRB. Initial standard phototests that were all positive found the induction of erythema and whealing, while when IRR was blocked from the UVA and visible light sources, three of the patients developed no lesions, while the fourth developed a very small wheal. These results suggest that IRR has the potential to produce and exacerbate lesions caused by other types of radiation. Consideration of these effects during phototesting could help prevent diagnostic errors. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  8. Radiation Metabolomics: Current Status and Future Directions

    Directory of Open Access Journals (Sweden)

    Smrithi eSugumaran Menon

    2016-02-01

    Full Text Available Human exposure to ionizing radiation disrupts normal metabolic processes in cells and organs by inducing complex biological responses that interfere with gene and protein expression. Conventional dosimetry, monitoring of prodromal symptoms and peripheral lymphocyte counts are of limited value as organ and tissue specific biomarkers for personnel exposed to radiation, particularly, weeks or months after exposure. Analysis of metabolites generated in known stress-responsive pathways by molecular profiling helps to predict the physiological status of an individual in response to environmental or genetic perturbations. Thus, a multi-metabolite profile obtained from a high resolution mass spectrometry-based metabolomics platform offers potential for identification of robust biomarkers to predict radiation toxicity of organs and tissues resulting from exposures to therapeutic or non-therapeutic ionizing radiation. Here, we review the status of radiation metabolomics and explore applications as a standalone technology, as well as its integration in systems biology, to facilitate a better understanding of the molecular basis of radiation response. Finally, we draw attention to the identification of specific pathways that can be targeted for the development of therapeutics to alleviate or mitigate harmful effects of radiation exposure.

  9. Properties of solar generators with reflectors and radiators

    Science.gov (United States)

    Ebeling, W. D.; Rex, D.; Bierfischer, U.

    1980-06-01

    Radiation cooled concentrator systems using silicon and GaAs cells were studied. The principle of radiation cooling by the reflector surfaces is discussed for cylindrical parabolic reflectors (SARA), truncated hexagonal pyramids, and a small trough configuration. Beam paths, collection properties for imperfect orientation, and thermal optimization parameters were analyzed. The three concentrating systems with radiation cooling offer advantages over the plane panel and over the large trough. With silicon solar cells they exhibit considerably lower solar cell consumption per Kw and also lower mass per kW. With GaAs cells the SARA system reduces the number of solar cells needed per kW to less than 10%. Also in all other cases SARA offers the best values for alpha and F sub sol, as long as narrow angular tolerances of the panel orientation can be met. Analysis of the energy collecting properties for imperfect orientation shows the superiority of the hexagonal concentrator. This device can produce power for even large angles between the sun and the panel normal.

  10. Effects of solar ultraviolet radiation on tropical algal communities

    International Nuclear Information System (INIS)

    Santas, R.

    1989-01-01

    This study assessed some of the effects of solar ultraviolet (UV) radiation ion coral reef algal assemblages. The first part of the investigation was carried out under controlled laboratory conditions in the coral reef microcosm at the National Museum of Natural History in Washington, D.C., while a field counterpart was completed at the Smithsonian Institution's marine station on Grand Turk, Turks and Caicos Islands, in the eastern Caribbean. The study attempted to separate the effects of UV-A from those of UV-B. In the laboratory, algal turf assemblages exposed to simulated solar UV radiation produced 55.1% less biomass than assemblages that were not exposed to UV. Assemblages not exposed to UV were dominated by Ectocarpus rhodochondroides, whereas in the assemblage developing under high UV radiation, Enteromorpha prolifera and eventually Schizothrix calcicola dominated. Lower UV-B irradiances caused a proportional reduction in biomass production and had less pronounced effects on species composition. UV-A did not have any significant effects on either algal turf productivity or community structure. In the field, assemblages exposed to naturally occurring solar UV supported a biomass 40% lower than that of assemblages protected from UV-B exposure. Once again, UV-A did not inhibit algal turf productivity

  11. Global solar radiation estimation in Lavras region, Minas Gerais

    International Nuclear Information System (INIS)

    Dantas, A.A.A.; Carvalho, L.G. de; Ferreira, E.

    2003-01-01

    The objective of this work was the determination of the ''a'' and '' b'' constants of the Angstrom linear model in order to estimate the global solar radiation in Lavras, MG. The work was carried out in the Climatological Station of Lavras (ECP/INMET/UFLA), at the Federal University of Lavras, from December 2001 to November 2002, through insolation daily data and global solar radiation daily records. The ''a'' and '' b'' constants, that express the atmospheric transmitance, were obtained by regression analysis of those data. The obtained equation, Qg/Qt = 0,23 + 0,49 presented a determination coefficient of 0,89. The results are smaller than those suggested by the recommendations that uses the local latitude. According to the results, its possible to indicate the values of 0,23 and 0,49 to be used as the ''a'' and '' b'' constants on the Angstrom equation to estimate the global solar radiation in Lavras, MG. (author) [pt

  12. Solar radiation modelling using ANNs for different climates in China

    International Nuclear Information System (INIS)

    Lam, Joseph C.; Wan, Kevin K.W.; Yang, Liu

    2008-01-01

    Artificial neural networks (ANNs) were used to develop prediction models for daily global solar radiation using measured sunshine duration for 40 cities covering nine major thermal climatic zones and sub-zones in China. Coefficients of determination (R 2 ) for all the 40 cities and nine climatic zones/sub-zones are 0.82 or higher, indicating reasonably strong correlation between daily solar radiation and the corresponding sunshine hours. Mean bias error (MBE) varies from -3.3 MJ/m 2 in Ruoqiang (cold climates) to 2.19 MJ/m 2 in Anyang (cold climates). Root mean square error (RMSE) ranges from 1.4 MJ/m 2 in Altay (severe cold climates) to 4.01 MJ/m 2 in Ruoqiang. The three principal statistics (i.e., R 2 , MBE and RMSE) of the climatic zone/sub-zone ANN models are very close to the corresponding zone/sub-zone averages of the individual city ANN models, suggesting that climatic zone ANN models could be used to estimate global solar radiation for locations within the respective zones/sub-zones where only measured sunshine duration data are available. (author)

  13. Directional Radiation Dosimeter for Area and Environmental Monitoring

    International Nuclear Information System (INIS)

    Manzoli, J.E.; Campos, V.P.; Moura, E.S.

    2009-01-01

    It is presented a dosimeter that is able to measure the photon exposure and the direction from where the radiation came from. Preliminary measurements performed by this new directional radiation dosimeter demonstrate its application. This dosimeter consists of a small lead cube with thermoluminescent discs on each face, placed in well known coordinates. Only one dosimeter of this kind indicates the direction of the radiation beam, if it came from a unique position. This study was conducted inside the radiation room of a Cobalt-60 Gamma Irradiator and the dosimeter indicated the source position

  14. Prediction of Global Solar Radiation in India Using Artificial Neural Network

    Directory of Open Access Journals (Sweden)

    Rajiv Gupta

    2016-06-01

    Full Text Available Increasing global warming and decreasing fossil fuel reserves has necessitated the use of renewable energy resources like solar energy in India. To maximize return on a solar farm, it had to be set up at a place with high solar radiation. The solar radiation values are available only for a small number of places and must be interpolated for the rest. This paper utilizes Artificial Neural Network in interpolation, by obtaining a function with input as combinations of 7 geographical and meteorological parameters affecting radiation, and output as global solar radiation. Data considered was of past 9 years for 13 Indian cities. Low error values and high coefficient of determination values thus obtained, verified that the results were accurate in terms of the original solar radiation data known. Thus, artificial neural network can be used to interpolate the solar radiation for the places of interest depending on the availability of the data.

  15. Solar Radiation and Cloud Radiative Forcing in the Pacific Warm Pool Estimated Using TOGA COARE Measurements

    Science.gov (United States)

    Chou, Ming-Dah; Chou, Shu-Hsien; Zhao, Wenzhong

    1999-01-01

    The energy budget of the tropical western Pacific (TWP) is particularly important because this is one of the most energetic convection regions on the Earth. Nearly half of the solar radiation incident at the top of atmosphere is absorbed at the surface and only about 22% absorbed in the atmosphere. A large portion of the excess heat absorbed at the surface is transferred to the atmosphere through evaporation, which provides energy and water for convection and precipitation. The western equatorial Pacific is characterized by the highest sea surface temperature (SST) and heaviest rainfall in the world ocean. A small variation of SST associated with the eastward shift of the warm pool during El-Nino/Souther Oscillation changes the atmospheric circulation pattern and affects the global climate. In a study of the TWP surface heat and momentum fluxes during the Tropical Ocean and Global Atmosphere Coupled Ocean-Atmosphere Response Experiment (TOGA COARE) Intensive observing period (IOP) from November 1992 to February have found that the solar radiation is the most important component of the surface energy budget, which undergoes significant temporal and spatial variation. The variations are influenced by the two 40-50 days Madden Julian Oscillations (MJOs) which propagated eastward from the Indian Ocean to the Central Pacific during the IOP. The TWP surface solar radiation during the COARE IOP was investigated by a number of studies. In addition, the effects of clouds on the solar heating of the atmosphere in the TWP was studied using energy budget analysis. In this study, we present some results of the TWP surface solar shortwave or SW radiation budget and the effect of clouds on the atmospheric solar heating using the surface radiation measurements and Japan's Geostationary Meteorological Satellite 4 radiance measurements during COARE IOP.

  16. Solar radiation as a forest management tool: a primer of principles and application

    Science.gov (United States)

    Howard G. Halverson; James L. Smith

    1979-01-01

    Forests are products of solar radiation use. The sun also drives the hydrologic cycle on forested watersheds. Some basic concepts of climatology and solar radiation are summarized in including earth-sun relations, polar tilt, solar energy, terrestrial energy, energy balance, and local energy. An example shows how these principles can be applied in resource management....

  17. Slowly varying component of extreme ultraviolet solar radiation and its relation to solar radio radiation

    Science.gov (United States)

    Chapman, R. D.; Neupert, W. M.

    1974-01-01

    A study of the correlations between solar EUV line fluxes and solar radio fluxes has been carried out. A calibration for the Goddard Space Flight Center EUV spectrum is suggested. The results are used to obtain an equation for the absolute EUV flux for several lines in the 150- to 400-A region and the total flux of 81 intense lines in the region, the 2800-MHz radio flux being used as independent variable.

  18. Effective aerosol optical depth from pyranometer measurements of surface solar radiation (global radiation) at Thessaloniki, Greece

    OpenAIRE

    Lindfors, A. V.; Kouremeti, N.; Arola, A.; Kazadzis, S.; Bais, A. F.; Laaksonen, A.

    2013-01-01

    Pyranometer measurements of the solar surface radiation (SSR) are available at many locations worldwide, often as long time series covering several decades into the past. These data constitute a potential source of information on the atmospheric aerosol load. Here, we present a method for estimating the aerosol optical depth (AOD) using pyranometer measurements of the SSR together with total water vapor column information. The method, which is based on radiative transfer simulations, w...

  19. A spectroscopic study on the effect of ultra-violet solar radiation in Antarctica on the human skin fibroblast cells

    Directory of Open Access Journals (Sweden)

    Tatsuyuki Yamamoto

    2013-11-01

    Full Text Available A study on the effect of the solar ultra-violet radiation on the human skin fibroblast cells revealed that the production of matrix metalloproteinase-2 was inhibited by the radiation. A CO2 incubator connected by optical fibers to a reflector telescope for collecting the solar light was built at Syowa station by the 49th Japanese Antarctica Research Expedition. The direction of the telescope was continuously controlled by a sun-tracker to follow the movement of the Sun automatically. The intensity of the collected light was monitored by a portable spectrophotometer housed inside. The human skin fibroblast cells were incubated in the CO2 chamber to investigate the effect of the solar radiation at Syowa station and were compared with those reference experiments at a laboratory in Japan. The results showed cell damage by strong UV radiation. The production of matrix metalloproteinase-2 was prompted by the moderate UV-B, but was inhibited by the strong UV-B radiation, as studied under laboratory conditions in Japan. The effect of strong solar radiation at Syowa station involving the radiation of UV-B region was estimated to be of the same extent of the radiation caused by an artificial UV-B light with the intensity more than 50 mJ/cm2.

  20. Numerical simulation of thermal behaviors of a clothed human body with evaluation of indoor solar radiation

    International Nuclear Information System (INIS)

    Mao, Aihua; Luo, Jie; Li, Yi

    2017-01-01

    Highlights: • Solar radiation evaluation is integrated with the thermal transfer in clothed humans. • Thermal models are developed for clothed humans exposed in indoor solar radiation. • The effect of indoor solar radiation on humans can be predicted in different situations in living. • The green solar energy can be efficiently utilized in the building development. - Abstract: Solar radiation is a valuable green energy, which is important in achieving a successful building design for thermal comfort in indoor environment. This paper considers solar radiation indoors into the transient thermal transfer models of a clothed human body and offers a new numerical method to analyze the dynamic thermal status of a clothed human body under different solar radiation incidences. The evaluation model of solar radiation indoors and a group of coupled thermal models of the clothed human body are developed and integrated. The simulation capacities of these integrated models are validated through a comparison between the predicted results and the experimental data in reference. After that, simulation cases are also conducted to show the influence of solar radiation on the thermal status of individual clothed body segments when the human body is staying indoors in different seasons. This numerical simulation method provides a useful tool to analyze the thermal status of clothed human body under different solar radiation incidences indoors and thus enables the architect to efficiently utilize the green solar energy in building development.

  1. Effects of solar radiation on grape (Vitis vinifera L.) composition and dried fruit colour

    International Nuclear Information System (INIS)

    Uhlig, B.A.

    1998-01-01

    Most sun-exposed fruit (Vitis vinifera L.) produced dark brown berries with low L-values, whereas most dried berries from shade fruit were acceptable in lightness although some had a green tinge. Fruit shaded by the natural vine canopy or exposed to direct solar radiation had similar drying ratios. However, berry weights were significantly higher in the shade than in the sun for both cultivars. The difference in berry weight between the two positions was less pronounced in the heat affected year. Solar radiation changed the composition of fresh berries and the colour of the dried fruit. The soluble-solid concentration was higher in fresh fruit exposed to direct solar radiation than in fruit grown in shaded conditions within the canopy. In the heat affected year the berries from both positions had the same soluble-solid concentrations, possibly due to dehydration of the fruit. No significant difference was found between the pH of sun fruit and shade fruit, but the titratable acidity was higher in shade fruit. Malate and tartrate concentrations in berry skin and the polyphenol oxidase activities had carotenoid concentrations in whole fresh berries were not significantly different for sun and shade fruit. Total phenol concentrations in berry skin were higher in sun fruit and chlorophyll concentrations in whole, fresh berries were higher in shade fruit. (author)

  2. Effect of solar radiation on severity of soybean rust.

    Science.gov (United States)

    Young, Heather M; George, Sheeja; Narváez, Dario F; Srivastava, Pratibha; Schuerger, Andrew C; Wright, David L; Marois, James J

    2012-08-01

    Soybean rust (SBR), caused by Phakopsora pachyrhizi, is a damaging fungal disease of soybean (Glycine max). Although solar radiation can reduce SBR urediniospore survival, limited information is available on how solar radiation affects SBR progress within soybean canopies. Such information can aid in developing accurate SBR prediction models. To manipulate light penetration into soybean canopies, structures of shade cloth attenuating 30, 40, and 60% sunlight were constructed over soybean plots. In each plot, weekly evaluations of severity in lower, middle, and upper canopies, and daily temperature and relative humidity were recorded. Final plant height and leaf area index were also recorded for each plot. The correlation between amount of epicuticular wax and susceptibility of leaves in the lower, middle, and upper canopies was assessed with a detached leaf assay. Final disease severity was 46 to 150% greater in the lower canopy of all plots and in the middle canopy of 40 and 60% shaded plots. While daytime temperature within the canopy of nonshaded soybean was greater than shaded soybean by 2 to 3°C, temperatures recorded throughout typical evenings and mornings of the growing season in all treatments were within the range (10 to 28.5°C) for SBR development as was relative humidity. This indicates temperature and relative humidity were not limiting factors in this experiment. Epicuticular wax and disease severity in detached leaf assays from the upper canopy had significant negative correlation (P = 0.009, R = -0.84) regardless of shade treatment. In laboratory experiments, increasing simulated total solar radiation (UVA, UVB, and PAR) from 0.15 to 11.66 MJ m(-2) increased mortality of urediniospores from 2 to 91%. Variability in disease development across canopy heights in early planted soybean may be attributed to the effects of solar radiation not only on urediniospore viability, but also on plant height, leaf area index, and epicuticular wax, which influence

  3. ISEE observations of radiation at twice the solar wind plasma frequency

    International Nuclear Information System (INIS)

    Lacombe, C.; Harvey, C.C.; Hoang, S.

    1988-01-01

    Radiation produced in the vicinity of the Earth's bow shock at twice the solar wind electron plasma frequency f p is seen by both ISEE-1 and ISEE-3, respectively at about 20 and about 200 R E from the Earth. This electromagnetic radiation is due to the presence, in the electron foreshock, of electrons reflected and accelerated at the Earth's bow shock. We show that the source is near the upstream boundary of the foreshock, the surface where the magnetic field lines are tangent to the bow shock. A typical diameter of the source is 120-150 R E . Emissivity is given. The angular size of the source, seen by ISEE-3, is increased by scattering of the 2f p radio waves on the solar wind density fluctuations. We examine whether the bandwidth and directivity predicted by current source models are consistent with our observations

  4. Ground-based spectral measurements of solar radiation, (2)

    International Nuclear Information System (INIS)

    Murai, Keizo; Kobayashi, Masaharu; Goto, Ryozo; Yamauchi, Toyotaro

    1979-01-01

    A newly designed spectro-pyranometer was used for the measurement of the global (direct + diffuse) and the diffuse sky radiation reaching the ground. By the subtraction of the diffuse component from the global radiation, we got the direct radiation component which leads to the spectral distribution of the optical thickness (extinction coefficient) of the turbid atmosphere. The measurement of the diffuse sky radiation reveals the scattering effect of aerosols and that of the global radiation allows the estimation of total attenuation caused by scattering and absorption of aerosols. The effects of the aerosols are represented by the deviation of the real atmosphere measured from the Rayleigh atmosphere. By the combination of the measured values with those obtained by theoretical calculation for the model atmosphere, we estimated the amount of absorption by the aerosols. Very strong absorption in the ultraviolet region was recognized. (author)

  5. Photocatalysis and radiation absorption in a solar plant

    Energy Technology Data Exchange (ETDEWEB)

    Curco, D; Gimenez, J [Departamento de Ingenieria Quimica, Facultad de Quimica, Universidad de Barcelona, Barcelona (Spain); Malato, S; Blanco, J [Centro de Investigaciones Energeticas, Medioambientales y Tecnologicas, Plataforma Solar de Almeria, Almeria (Spain)

    1996-11-15

    Recently, many papers have appeared in literature about photocatalytic detoxification. However, progress from laboratory data to the industrial solar reactor is not easy. Kinetic models for heterogeneous catalysis can be used to describe the photocatalytic processes, but luminic steps, related to the radiation, have to be added to the physical and chemical steps considered in heterogeneous catalysis. Thus, the evaluation of the radiation, and its distribution, inside a photocatalytic reactor is essential to extrapolate results from laboratory to outdoor experiments and to compare the efficiency of different installations. This study attempts to validate the experimental set up and theoretical data treatment for this purpose in a Solar Pilot Plant. The procedure consists of the calibration of different sunlight radiometers, the estimation of the radiation inside the reactor, and the validation of the results by actinometric experiments. Finally, a comparison between kinetic constants, for the same reaction in the laboratory (artificial light) and field conditions (sun light), is performed to demonstrate the advantages of knowing the radiation inside a large photochemical reactor

  6. Measuring solar UV radiation with EBT radiochromic film

    International Nuclear Information System (INIS)

    Butson, Ethan T; Cheung Tsang; Yu, Peter K N; Butson, Martin J

    2010-01-01

    Ultraviolet radiation dosimetry has been performed with the use of a radiochromic film dosimeter called Gafchromic EBT for solar radiation exposure. The film changes from a clear colour to blue colour when exposed to ultraviolet radiation and results have shown that the colour change is reproducible within ±10% at 5 kJ m -2 UV exposure under various conditions of solar radiation. Parameters tested included changes in season (summer versus winter exposure), time of day, as well as sky conditions such as cloudy skies versus clear skies. As the radiochromic films' permanent colour change occurs in the visible wavelengths the film can be analysed with a desktop scanner with the most sensitive channel for analysis being the red component of the signal. Results showed that an exposure of 5 kJ m -2 (approximately 1 h exposure in full sun during summer) produced an approximate 0.28 change in the net OD when analysed in reflection mode on the desktop scanner which is significant darkening. The main advantages of this film type, and thus the new EBT2 film which has replaced EBT for measurement of UV exposure, is the visible colour change and thus easy analysis using a desktop scanner, its uniformity in response and its robust physical strength for use in outside exposure situations. (note)

  7. Solar Radiation Pressure Binning for the Geosynchronous Orbit

    Science.gov (United States)

    Hejduk, M. D.; Ghrist, R. W.

    2011-01-01

    Orbital maintenance parameters for individual satellites or groups of satellites have traditionally been set by examining orbital parameters alone, such as through apogee and perigee height binning; this approach ignored the other factors that governed an individual satellite's susceptibility to non-conservative forces. In the atmospheric drag regime, this problem has been addressed by the introduction of the "energy dissipation rate," a quantity that represents the amount of energy being removed from the orbit; such an approach is able to consider both atmospheric density and satellite frontal area characteristics and thus serve as a mechanism for binning satellites of similar behavior. The geo-synchronous orbit (of broader definition than the geostationary orbit -- here taken to be from 1300 to 1800 minutes in orbital period) is not affected by drag; rather, its principal non-conservative force is that of solar radiation pressure -- the momentum imparted to the satellite by solar radiometric energy. While this perturbation is solved for as part of the orbit determination update, no binning or division scheme, analogous to the drag regime, has been developed for the geo-synchronous orbit. The present analysis has begun such an effort by examining the behavior of geosynchronous rocket bodies and non-stabilized payloads as a function of solar radiation pressure susceptibility. A preliminary examination of binning techniques used in the drag regime gives initial guidance regarding the criteria for useful bin divisions. Applying these criteria to the object type, solar radiation pressure, and resultant state vector accuracy for the analyzed dataset, a single division of "large" satellites into two bins for the purposes of setting related sensor tasking and orbit determination (OD) controls is suggested. When an accompanying analysis of high area-to-mass objects is complete, a full set of binning recommendations for the geosynchronous orbit will be available.

  8. Comparative study of series of solar radiation; Estudio comparativo de series de radiacion solar

    Energy Technology Data Exchange (ETDEWEB)

    Adaro, Agustin; Cesari, Daniela; Lema, Alba; Galimberti, Pablo; Barral, Jorge [Universidad Nacional de Rio Cuarto, (Argentina)

    2000-07-01

    In any team or solar device that it seeks to be designed and dedicated to the use of the solar energy it will be had the most appropriate information on the radiation levels. Being this source of dependent energy of the atmospheric and meteorological fluctuations, it is that requires have the information best regarding the quantity and variability of the available solar energy. A road is already the statistical treatment of the data available, so much of solar radiation as of hours of sun. This focus generates a lot of expectation for the biggest quantity in information regarding the hours of existent sun. This bigger information of hours of sun is due to that the mensurations are carried out with instruments called heliografos with a level of complexity and much smaller cost that the instruments of radiation mensuration. Among the heliografos the most used one is that of Campbell-Stokes, and it is the one that you had installed in most of the meteorological stations of Argentina and the World, for what the information of hours of sun is the one that more is plentiful. The present work has for objective to find an interrelation between the measured series of hours of sun and irradiation. The study is carried out using models of temporary series and the pattern of Angstrom-Page. The are carried out a study of the generation of radiation sequences using models of temporary series and the pattern of Angstrom-Page. They are carried out a study of the generation of radiation sequences using the concept of the Chains of Markov. Rio Cuarto's series are analyzed for being determined the transfer function among both series, and the values of global solar radiation are obtained for towns of the same region. They are the coefficients of Anstrom-Page's Equation for Rio Cuarto. They are the values monthly means for these two methods and results are compared. [Spanish] En cualquier equipo o dispositivo solar que pretenda ser disenado y destinado al aprovechamiento de

  9. Optically pumped carbon dioxide laser mixtures. [using solar radiation

    Science.gov (United States)

    Yesil, O.; Christiansen, W. H.

    1979-01-01

    This work explores the concept of blackbody radiation pumping of CO2 gas as a step toward utilization of solar radiation as a pumping source for laser action. To demonstrate this concept, an experiment was performed in which laser gas mixtures were exposed to 1500 K thermal radiation for brief periods of time. A gain of 2.8 x 10 to the -3rd reciprocal centimeters has been measured at 10.6 microns in a CO2-He gas mixture of 1 Torr pressure. A simple analytical model is used to describe the rate of change of energy of the vibrational modes of CO2 and to predict the gain. Agreement between the prediction and experiment is good.

  10. Three-dimensional transfer of solar radiation in clouds

    International Nuclear Information System (INIS)

    Davies, R.

    1976-01-01

    The results of a theoretical study of the effects of cloud geometry on the transfer of incident solar radiation is presented. These results indicate that a three-dimensional description of cloud geometry is a necessary prerequisite to the accurate determination of the emerging radiation field. Models which make the plane parallel assumption are therefore frequently inadequate. Both a Monte Carlo method and an analytic method were used to model the three-dimensional transfer of radiation. At the expense of considerable computation time the Monte Carlo model provides accurate values of the fluxes and intensities (averages over π/30 steradians) emerging from clouds which can be described as a set of connected cuboidal cells, each cell being homogeneous with respect to extinction coefficient, single scatter albedo and phase function. The analytic model, based on an extension of Eddington's approximation to three dimensions and to anisotropic scattering, is efficient to use, but is restricted to clouds made up of a single cuboidal cell and is more accurate for large clouds than small ones. By an iterated approach, involving integration of the source function along line of sight, the analytic model provides both fluxes and intensities of the emerging radiation at any specified point on the cloud's surface. These models were both applied to a systematic study of the transfer of solar radiation in isolated cuboidal clouds of arbitraty dimensions, the results of which illustrate the importance of considering the total cloud geometry in any attempt at realistic modelling. A study of the transfer of radiation in stratiform clouds with turretted top surfaces also indicated that even for these clouds the plane parallel assumption was often not tenable

  11. Radiation Belt Transport Driven by Solar Wind Dynamic Pressure Fluctuations

    Science.gov (United States)

    Kress, B. T.; Hudson, M. K.; Ukhorskiy, A. Y.; Mueller, H.

    2012-12-01

    The creation of the Earth's outer zone radiation belts is attributed to earthward transport and adiabatic acceleration of electrons by drift-resonant interactions with electromagnetic fluctuations in the magnetosphere. Three types of radial transport driven by solar wind dynamic pressure fluctuations that have been identified are: (1) radial diffusion [Falthammer, 1965], (2) significant changes in the phase space density radial profile due to a single or few ULF drift-resonant interactions [Ukhorskiy et al., 2006; Degeling et al., 2008], and (3) shock associated injections of radiation belt electrons occurring in less than a drift period [Li et al., 1993]. A progress report will be given on work to fully characterize different forms of radial transport and their effect on the Earth's radiation belts. The work is being carried out by computing test-particle trajectories in electric and magnetic fields from a simple analytic ULF field model and from global MHD simulations of the magnetosphere. Degeling, A. W., L. G. Ozeke, R. Rankin, I. R. Mann, and K. Kabin (2008), Drift resonant generation of peaked relativistic electron distributions by Pc 5 ULF waves, textit{J. Geophys. Res., 113}, A02208, doi:10.1029/2007JA012411. Fälthammar, C.-G. (1965), Effects of Time-Dependent Electric Fields on Geomagnetically Trapped Radiation, J. Geophys. Res., 70(11), 2503-2516, doi:10.1029/JZ070i011p02503. Li, X., I. Roth, M. Temerin, J. R. Wygant, M. K. Hudson, and J. B. Blake (1993), Simulation of the prompt energization and transport of radiation belt particles during the March 24, 1991 SSC, textit{Geophys. Res. Lett., 20}(22), 2423-2426, doi:10.1029/93GL02701. Ukhorskiy, A. Y., B. J. Anderson, K. Takahashi, and N. A. Tsyganenko (2006), Impact of ULF oscillations in solar wind dynamic pressure on the outer radiation belt electrons, textit{Geophys. Res. Lett., 33}(6), L06111, doi:10.1029/2005GL024380.

  12. Estimation of solar radiation over Turkey using artificial neural network and satellite data

    International Nuclear Information System (INIS)

    Senkal, Ozan; Kuleli, Tuncay

    2009-01-01

    This study introduces artificial neural networks (ANNs) for the estimation of solar radiation in Turkey (26-45 E and 36-42 N). Resilient propagation (RP), Scale conjugate gradient (SCG) learning algorithms and logistic sigmoid transfer function were used in the network. In order to train the neural network, meteorological data for the period from August 1997 to December 1997 for 12 cities (Antalya, Artvin, Edirne, Kayseri, Kuetahya, Van, Adana, Ankara, Istanbul, Samsun, Izmir, Diyarbakir) spread over Turkey were used as training (nine stations) and testing (three stations) data. Meteorological and geographical data (latitude, longitude, altitude, month, mean diffuse radiation and mean beam radiation) are used in the input layer of the network. Solar radiation is the output. However, solar radiation has been estimated as monthly mean daily sum by using Meteosat-6 satellite C3 D data in the visible range over 12 cities in Turkey. Digital counts of satellite data were converted into radiances and these are used to calculate the albedos. Using the albedo, the cloud cover index of each pixel was constructed. Diffuse and direct component of horizontal irradiation were calculated as a function of optical air mass, turbidity factor and Rayleigh optical thickness for clear-sky. Using the relation between clear-sky index and cloud cover index, the solar irradiance for any pixel is calculated for Physical method. RMS between the estimated and ground values for monthly mean daily sum with ANN and Physical method values have been found as 2.32 MJ m -2 (54 W/m 2 ) and 2.75 MJ m -2 (64 W/m 2 ) (training cities), 3.94 MJ m -2 (91 W/m 2 ) and 5.37 MJ m -2 (125 W/m 2 ) (testing cities), respectively

  13. [Comparison of three daily global solar radiation models].

    Science.gov (United States)

    Yang, Jin-Ming; Fan, Wen-Yi; Zhao, Ying-Hui

    2014-08-01

    Three daily global solar radiation estimation models ( Å-P model, Thornton-Running model and model provided by Liu Ke-qun et al.) were analyzed and compared using data of 13 weather stations from 1982 to 2012 from three northeastern provinces and eastern Inner Mongolia. After cross-validation analysis, the result showed that mean absolute error (MAE) for each model was 1.71, 2.83 and 1.68 MJ x m(-2) x d(-1) respectively, showing that Å-P model and model provided by Liu Ke-qun et al. which used percentage of sunshine had an advantage over Thornton-Running model which didn't use percentage of sunshine. Model provided by Liu Ke-qun et al. played a good effect on the situation of non-sunshine, and its MAE and bias percentage were 18.5% and 33.8% smaller than those of Å-P model, respectively. High precision results could be obtained by using the simple linear model of Å-P. Å-P model, Thornton-Running model and model provided by Liu Ke-qun et al. overvalued daily global solar radiation by 12.2%, 19.2% and 9.9% respectively. MAE for each station varied little with the spatial change of location, and annual MAE decreased with the advance of years. The reason for this might be that the change of observation accuracy caused by the replacement of radiation instrument in 1993. MAEs for rainy days, non-sunshine days and warm seasons of the three models were greater than those for days without rain, sunshine days and cold seasons respectively, showing that different methods should be used for different weather conditions on estimating solar radiation with meteorological elements.

  14. Development of gridded solar radiation data over Belgium based on Meteosat and in-situ observations

    Science.gov (United States)

    Journée, Michel; Vanderveken, Gilles; Bertrand, Cédric

    2013-04-01

    Knowledge on solar resources is highly important for all forms of solar energy applications. With the recent development in solar-based technologies national meteorological services are faced with increasing demands for high-quality and reliable site-time specific solar resource information. Traditionally, solar radiation is observed by means of networks of meteorological stations. Costs for installation and maintenance of such networks are very high and national networks comprise only few stations. Consequently the availability of ground-based solar radiation measurements has proven to be spatially and temporally inadequate for many applications. To overcome such a limitation, a major effort has been undertaken at the Royal Meteorological Institute of Belgium (RMI) to provide the solar energy industry, the electricity sector, governments, and renewable energy organizations and institutions with the most suitable and accurate information on the solar radiation resources at the Earth's surface over the Belgian territory. Only space-based observations can deliver a global coverage of the solar irradiation impinging on horizontal surface at the ground level. Because only geostationary data allow to capture the diurnal cycle of the solar irradiance at the Earth's surface, a method that combines information from Meteosat Second Generation satellites and ground-measurement has been implemented at RMI to generate high resolution solar products over Belgium on an operational basis. Besides these new products, the annual and seasonal variability of solar energy resource was evaluated, solar radiation climate zones were defined and the recent trend in solar radiation was characterized.

  15. Photocatalytic hydrogen production under direct solar light in a CPC based solar reactor: Reactor design and preliminary results

    International Nuclear Information System (INIS)

    Jing Dengwei; Liu Huan; Zhang Xianghui; Zhao Liang; Guo Liejin

    2009-01-01

    In despite of so many types of solar reactors designed for solar detoxification purposes, few attempts have been made for photocatalytic hydrogen production, which in our option, is one of the most promising approaches for solar to chemical energy conversion. Addressing both the similarity and dissimilarity for these two processes and by fully considering the special requirements for the latter reaction, a Compound Parabolic Concentrator (CPC) based photocatalytic hydrogen production solar reactor has been designed for the first time. The design and optimization of this CPC based solar reactor has been discussed in detail. Preliminary results demonstrated that efficient photocatalytic hydrogen production under direct solar light can be accomplished by coupling tubular reactors with CPC concentrators. It is anticipated that this first demonstration of concentrator-based solar photocatalytic hydrogen production would draw attention for further studies in this promising direction.

  16. Solar and Net Radiation for Estimating Potential Evaporation from Three Vegetation Canopies

    Science.gov (United States)

    D.M. Amatya; R.W. Skaggs; G.W. Cheschier; G.P. Fernandez

    2000-01-01

    Solar and net radiation data are frequent/y used in estimating potential evaporation (PE) from various vegetative surfaces needed for water balance and hydrologic modeling studies. Weather parameters such as air temperature, relative humidity, wind speed, solar radiation, and net radiation have been continuously monitored using automated sensors to estimate PE for...

  17. Application of solar radiation for heating and preparation of warm water in an individual house

    International Nuclear Information System (INIS)

    Kozak, Tadeeusz; Majchrzycka, Anna

    2009-01-01

    The paper is aimed at analysis of application of the solar collectors array for preparing of warm water and space heating in an individual house. Keywords: application of solar radiation, preparation of warm water, heating

  18. Five years of solar UV-radiation monitoring in Sweden

    Energy Technology Data Exchange (ETDEWEB)

    Josefsson, Weine

    1996-10-01

    A network of five stations measuring the solar UV-radiation has been operated for about five years. Data are presented as plotted time-series of monthly and yearly values for the sites. A general climatology can be deduced from these data. Daily and hourly maximum values are shown for each month as indicators of the potential extreme exposure levels. The large annual variation at high latitudes is easily seen in the data set. This illustrates the importance of the solar elevation on the level of the UV-irradiance. Influence of cloud variation and of larger changes in ozone is also detectable. A few examples of the daily variation also show the strong solar elevation dependence of the UV-irradiance. The quantity and unit of the UV-radiation in this presentation is CIE-weighted irradiance expressed as MED (minimum erythermal dose), where one MED equals 210 Jm{sup -2}. The values have been recomputed to refer to the international intercomparison of broad-band meters in Helsinki in 1995. In the following named WMO-STUK 1995 scale. As will be seen there are many sources of error and detailed studies are prevented by the large uncertainty connected with these data. Due to the short period of the record and the low accuracy no attempt to study trends is done. 6 refs, 27 figs, 4 tabs

  19. Development of a direct expansion solar assisted heat pump for hot water supply

    International Nuclear Information System (INIS)

    Abdesselam Hamloui; Ong, K.S.; Than Cheok Fah; Masjuki Hassan

    2000-01-01

    Experimental investigations were conducted on the direct expansion solar assisted Heat Pump (DESAHP). Refrigerant R-22 was expanded in the solar collector which also acted as the evaporator in a conventional vapor compression refrigerating machine. The experiments were conducted under conditions of high and low solar radiation, with evaporator completely shaded from the sun, and at night. System thermal performance was determined by measuring refrigerant flow rate, temperature and pressure at numerous points in the system. The results showed that 227-l of water could be heated from 3O degree to 55 degree C in about 105 minutes. Higher water temperatures were obtained during hot sunny days. The coefficient of performance of heating, COP h , ranged from 11 to 4.7, depending upon operating conditions. The total saving of electric energy during hot sunny days was about 460 %. It means that for 1 kWh of electrical input to the system, we achieve 4.6 kWh. This percentage decreases as the evaporator temperature decreases and is a function of solar energy input. (Author)

  20. Toward an Aqueous Solar Battery: Direct Electrochemical Storage of Solar Energy in Carbon Nitrides.

    Science.gov (United States)

    Podjaski, Filip; Kröger, Julia; Lotsch, Bettina V

    2018-03-01

    Graphitic carbon nitrides have emerged as an earth-abundant family of polymeric materials for solar energy conversion. Herein, a 2D cyanamide-functionalized polyheptazine imide (NCN-PHI) is reported, which for the first time enables the synergistic coupling of two key functions of energy conversion within one single material: light harvesting and electrical energy storage. Photo-electrochemical measurements in aqueous electrolytes reveal the underlying mechanism of this "solar battery" material: the charge storage in NCN-PHI is based on the photoreduction of the carbon nitride backbone and charge compensation is realized by adsorption of alkali metal ions within the NCN-PHI layers and at the solution interface. The photoreduced carbon nitride can thus be described as a battery anode operating as a pseudocapacitor, which can store light-induced charge in the form of long-lived, "trapped" electrons for hours. Importantly, the potential window of this process is not limited by the water reduction reaction due to the high intrinsic overpotential of carbon nitrides for hydrogen evolution, potentially enabling new applications for aqueous batteries. Thus, the feasibility of light-induced electrical energy storage and release on demand by a one-component light-charged battery anode is demonstrated, which provides a sustainable solution to overcome the intermittency of solar radiation. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Concentration of solar radiation by white painted transparent plates.

    Science.gov (United States)

    Smestad, G; Hamill, P

    1982-04-01

    A simple flat-plate solar concentrator is described in this paper. The device is composed of a white painted transparent plate with a photovoltaic cell fixed to an unpainted area on the bottom of the plate. Light scattering off the white material is either lost or directed to the solar cell. Experimental concentrations of up to 1.9 times the incident solar flux have been achieved using white clays. These values are close to those predicted by theory for the experimental parameters investigated. A theory of the device operation is developed. Using this theory suggestions are made for optimizing the concentrator system. For reasonable choices of cell and plate size and reflectivities of 80% concentrations of over 2x are possible. The concentrator has the advantage over other systems in that the concentration is independent of incidence angle and the concentrator is easy to produce. The device needs no tracking system and will concentrate on a cloudy day.

  2. Models in the estimate of the diffuse solar radiation; Modelos de estimativa da radiacao solar difusa

    Energy Technology Data Exchange (ETDEWEB)

    Recieri, Reinaldo Prandini; Ferruzzi, Yuri; Silva, Suedemio de Lima [Universidade Estadual do Oeste do Parana (UNIOESTE/FAG), Cascavel, PR (Brazil). Curso de Mestrado em Engenharia Agricola; Quallio, Silvana [Universidade Estadual do Oeste do Parana (UNIOESTE/FAG), Cascavel, PR (Brazil). Curso de Biologia; Batista, Vitor Roberto Lourenco [Universidade Estadual do Oeste do Parana (UNIOESTE/FAG), Cascavel, PR (Brazil). Curso de Graduacao em Engenharia Eletrica

    2004-07-01

    In this work we evaluate, by means of polynomial regression analysis, several models that relate the diffuse fraction of the global radiation (K{sub d}) with the clearness index (K{sub t}). The experiment was conducted in the Solar Radiometry Station of Cascavel/PR from the first of January to the 31st of December, in the year of 2001. The solar radiation components were monitored by the following manufactured instruments: pyranometer (KIPP and ZONEN CM3) and pirheliometer (EPPLEY NIP) connected in a sun tracker (ST-1 model). A datalogger CR10X from the CAMPBELL SCIENTIFIC was used in the data acquisition. This datalogger was programmed in the frequency of 1 Hz storing an average of 5 minutes of collected data. Among the equations the best values of RMSE an MBE were find in the fourth and third degrees, respectively. We also find that the fourth degree polynomial equation (K{sub d}=1,172-1,001K{sub t}+3,992K{sub t}{sup 2}-11,742K{sub t}{sup 3}+7,698K{sub t}{sup 4}) generalizes the utilization of equations for diffuse solar radiation estimation. This means that this equation probably can be applied for any place and climatic conditions. (author)

  3. Direct and indirect effects of radiation on polar solid solutions

    International Nuclear Information System (INIS)

    Ershov, V.G.; Gaponova, I.S.

    1982-01-01

    Radiation-chemical decomposition of a solute is due to the direct effect of ionizing radiation on it and also to its reaction with radical-ion products of radiolysis of the solution. At low temperature, the movement of the reagents is limited, and thus it is possible to isolate and evaluate the contribution of direct and indirect effects of radiation on the solute. The present paper is devoted to an investigation of the mechanism of formation of radicals from a solute (LiNO 2 ) in a polar solid solution (CH 3 OH) under the effect of γ-radiation

  4. Studies of the Solar Radiations' Influence About Geomembranes Used in Ecological Landfill

    Science.gov (United States)

    Vasiluta, Petre; Cofaru, Ileana Ioana; Cofaru, Nicolae Florin; Popa, Dragos Laurentiu

    2017-12-01

    The study shown in this paper presents the behavior of geomembranes used at the ecological landfills. The influences of the solar radiations has a great importance regarding the correct mounting of the geomembranes. The mathematical model developed for the determination anytime and anywhere in the world for the next values and parameters: apparent solar time, solar declination, solar altitude, solar azimuth and incidence angle, zone angle, angle of sun elevation, solar declination, solar constant, solar flux density, diffuse solar radiation, global radiation, soil albedo, total radiant flux density and relational links of these values. The results of this model was used for creations an AutoCAD subroutines useful for choosing the correct time for correct mounting anywhere of the geomembranes

  5. General characterisation of the solar radiation behaviour in Mozambique

    Energy Technology Data Exchange (ETDEWEB)

    Cuamba, B.C. [Renewable Energies Research and Training Programme, Department of Physics, Faculty of Sciences, Eduardo Mondlane University (UEM), Maputo (Mozambique)]|[Action Group for Renewable Energies and Sustainable Development, Maputo (Mozambique); Chenene, M.L.; Mahumane, G. [Renewable Energies Research and Training Programme, Department of Physics, Faculty of Sciences, Eduardo Mondlane University (UEM), Maputo (Mozambique); Quissico, D.Z. [Renewable Energies Research and Training Programme, Department of Physics, Faculty of Sciences, Eduardo Mondlane University (UEM), Maputo (Mozambique)]|[National Institute of Meteorology, Maputo (Mozambique); Vasco, E. [National Institute of Meteorology, Maputo (Mozambique); Lovseth, J. [Solar Energy and Environmental Group, Department of Physics (LADE), Trondheim University of Science and Technology (NTNU) (Norway); O' Keefe, P. [University of Northumbria at Newcastle, Newcastle Upon Tyne (United Kingdom)

    2004-07-01

    Just as with the other Southern African Development Community (SADC) countries, Mozambique faces severe and interrelated problems of energy and environment linked with the massive consumption of fuel wood biomass. The conventional power grid caters for less than 7% of the energy needs for the country's 17 million inhabitants, and about 83% of the energy consumed in the country comes from biomass. Areas around the major urban centres and along the main development corridors are the most affected by energy shortages. This hinders the country's economic and social development as it is generally acknowledged that no development can be sustainable without linking it to energy planning and environmental management. Renewable energy resources can play an important role in the process of development of the country. From the vast renewable energy resources available in the country, solar energy represents one of those with the highest potential. Thus the evaluation of its potential is of extreme importance. This paper represents a first attempt to systemise the solar radiation data being measured by the National Institute of Meteorology (INAM). The period considered for analysis is from 1970 to 2000. Results of the present work reveal that the country has substantial solar energy resources for a variety of solar energy technologies. (orig.)

  6. Effects of increased solar ultraviolet radiation on biogeochemical cycles

    International Nuclear Information System (INIS)

    Zepp, R.G.; Callaghan, T.V.; Erickson, D.J.

    1995-01-01

    Increases in solar UV radiation could affect terrestrial and aquatic biogeochemical cycles thus altering both sources and sinks of greenhouse and chemically important trace gases (e.g., carbon dioxide (CO2), carbon monoxide (CO), carbonyl sulfide (COS). In terrestrial ecosystems, increased UV-B could modify both the production and decomposition of plant matter with concomitant changes in the uptake and release of atmospherically important trace gases. Decomposition processes can be accelerated when UV-B photodegrades surface litter, or retarded when the dominant effect involves changes in the chemical composition of living tissues that reduce the biodegradability of buried litter. These changes in decomposition can affect microbial production of CO2 and other trace gases and also may affect the availability of nutrients essential for plant growth. Primary production can be reduced by enhanced UV-B, but the effect is variable between species and even cultivars of some crops. Likewise, the effects of enhanced UV-B on photoproduction of CO from plant matter is species-dependent and occurs more efficiently from dead than from living matter. Aquatic ecosystems studies in several different locations have shown that reductions in current levels of solar UV-B result in enhanced primary production, and Antarctic experiments under the ozone hole demonstrated that primary production is inhibited by enhanced UV-B. In addition to its effects on primary production, solar UV radiation can reduce bacterioplankton growth in the upper ocean with potentially important effects on marine biogeochemical cycles. Decomposition processes can be retarded when bacterial activity is suppressed by enhanced UV-B radiation or stimulated when solar UV radiation photodegrades aquatic dissolved organic matter. Photodegradation of DOM results in loss of UV absorption and formation of dissolved inorganic carbon, CO, and organic substrates that are readily mineralized or taken up by aquatic

  7. Cooling load calculation by the radiant time series method - effect of solar radiation models

    Energy Technology Data Exchange (ETDEWEB)

    Costa, Alexandre M.S. [Universidade Estadual de Maringa (UEM), PR (Brazil)], E-mail: amscosta@uem.br

    2010-07-01

    In this work was analyzed numerically the effect of three different models for solar radiation on the cooling load calculated by the radiant time series' method. The solar radiation models implemented were clear sky, isotropic sky and anisotropic sky. The radiant time series' method (RTS) was proposed by ASHRAE (2001) for replacing the classical methods of cooling load calculation, such as TETD/TA. The method is based on computing the effect of space thermal energy storage on the instantaneous cooling load. The computing is carried out by splitting the heat gain components in convective and radiant parts. Following the radiant part is transformed using time series, which coefficients are a function of the construction type and heat gain (solar or non-solar). The transformed result is added to the convective part, giving the instantaneous cooling load. The method was applied for investigate the influence for an example room. The location used was - 23 degree S and 51 degree W and the day was 21 of January, a typical summer day in the southern hemisphere. The room was composed of two vertical walls with windows exposed to outdoors with azimuth angles equals to west and east directions. The output of the different models of solar radiation for the two walls in terms of direct and diffuse components as well heat gains were investigated. It was verified that the clear sky exhibited the less conservative (higher values) for the direct component of solar radiation, with the opposite trend for the diffuse component. For the heat gain, the clear sky gives the higher values, three times higher for the peek hours than the other models. Both isotropic and anisotropic models predicted similar magnitude for the heat gain. The same behavior was also verified for the cooling load. The effect of room thermal inertia was decreasing the cooling load during the peak hours. On the other hand the higher thermal inertia values are the greater for the non peak hours. The effect

  8. A Novel Concentrator Photovoltaic (CPV System with the Improvement of Irradiance Uniformity and the Capturing of Diffuse Solar Radiation

    Directory of Open Access Journals (Sweden)

    Nguyen Xuan Tien

    2016-09-01

    Full Text Available This paper proposes a novel concentrator photovoltaic (CPV system with improved irradiation uniformity and system efficiency. CPV technology is very promising its for highly efficient solar energy conversion. A conventional CPV system usually uses only one optical component, such as a refractive Fresnel lens or a reflective parabolic dish, to collect and concentrate solar radiation on the solar cell surface. Such a system creates strongly non-uniform irradiation distribution on the solar cell, which tends to cause hot spots, current mismatch, and degrades the overall efficiency of the system. Additionally, a high-concentration CPV system is unable to collect diffuse solar radiation. In this paper, we propose a novel CPV system with improved irradiation uniformity and collection of diffuse solar radiation. The proposed system uses a Fresnel lens as a primary optical element (POE to concentrate and focus the sunlight and a plano-concave lens as a secondary optical element (SOE to uniformly distribute the sunlight over the surface of multi-junction (MJ solar cells. By using the SOE, the irradiance uniformity is significantly improved in the system. Additionally, the proposed system also captures diffuse solar radiation by using an additional low-cost solar cell surrounding MJ cells. In our system, incident direct solar radiation is captured by MJ solar cells, whereas incident diffuse solar radiation is captured by the low-cost solar cell. Simulation models were developed using a commercial optical simulation tool (LightTools™. The irradiance uniformity and efficiency of the proposed CPV system were analyzed, evaluated, and compared with those of conventional CPV systems. The analyzed and simulated results show that the CPV system significantly improves the irradiance uniformity as well as the system efficiency compared to the conventional CPV systems. Numerically, for our simulation models, the designed CPV with the SOE and low-cost cell provided

  9. A Proposal for a Thesaurus for Web Services in Solar Radiation

    Science.gov (United States)

    Gschwind, Benoit; Menard, Lionel; Ranchin, Thierry; Wald, Lucien; Stackhouse, Paul W., Jr.

    2007-01-01

    Metadata are necessary to discover, describe and exchange any type of information, resource and service at a large scale. A significant amount of effort has been made in the field of geography and environment to establish standards. Efforts still remain to address more specific domains such as renewable energies. This communication focuses on solar energy and more specifically on aspects in solar radiation that relate to geography and meteorology. A thesaurus in solar radiation is proposed for the keys elements in solar radiation namely time, space and radiation types. The importance of time-series in solar radiation is outlined and attributes of the key elements are discussed. An XML schema for encoding metadata is proposed. The exploitation of such a schema in web services is discussed. This proposal is a first attempt at establishing a thesaurus for describing data and applications in solar radiation.

  10. Interanual variability os solar radiation in Peninsula Iberica; Variabilidad interanual de la radiacion solar en la Peninsula Iberica

    Energy Technology Data Exchange (ETDEWEB)

    Pozo-Vazquez, D.; Tovar-Pescador, J.; Gamiz-Fortis, S.; Esteban-Parra, M.; Castro-Diez, Y.

    2004-07-01

    The NAO climatic phenomenon is the main responsible for the interanual cloud cover variability in Europe. We explore the relationship between the NAO and the solar radiation spatio-temporal variability in Europe during winter. Measured monthly sums of sunshine duration and short-wave downward solar flux reanalysis data have been used. Correlation analysis between the NAO index and the measured sunshine duration shows a maximum positive value (+0.75) over the Iberian Peninsula. Accordingly, solar radiation in this area undergoes an interanual variability that can reach up to 30%, with the derived consequences for a reliable solar energy resources evaluation. (Author)

  11. Analysis of the changing Solar Radiation Angle on Hainan Island

    Directory of Open Access Journals (Sweden)

    Ge Zhiwu

    2017-01-01

    Full Text Available As the only tropical provinces in China, Hainan province has advantageous geographical location, and abundant solar energy resources. But because of Local ideas and habits, especially the lack of theoretical research on local solar resources, development and application of solar energy in Hainan is almost blank. In this paper, we studied the variation regularity of sunlight angle on Hainan tropical island, analyzed the revolution and rotation of the earth, and the change rule of sunlight angle caused by the sun’s movement between the tropic of cancer and the tropic of capricorn, deduced the change rule of sunlight angle in the spring equinox, the autumnal equinox, summer solstice and winter solstice day, and got the movement rules of solar elevation angle throughout the year. Theoretic analysis is consistent with field measurement results. These rules are of importance and can effectively guide the local People’s daily life and production, such as the reasonable layout of the buildings, floor distance between different heights of buildings, the direction of the lighting windows of tall buildings, installation angle of photovoltaic panels, and other similar solar energy absorbing and conversion equipment.

  12. Solar Extreme UV radiation and quark nugget dark matter model

    Science.gov (United States)

    Zhitnitsky, Ariel

    2017-10-01

    We advocate the idea that the surprising emission of extreme ultra violet (EUV) radiation and soft x-rays from the Sun are powered externally by incident dark matter (DM) particles. The energy and the spectral shape of this otherwise unexpected solar irradiation is estimated within the quark nugget dark matter model. This model was originally invented as a natural explanation of the observed ratio Ωdark ~ Ωvisible when the DM and visible matter densities assume the same order of magnitude values. This generic consequence of the model is a result of the common origin of both types of matter which are formed during the same QCD transition and both proportional to the same fundamental dimensional parameter ΛQCD. We also present arguments suggesting that the transient brightening-like "nanoflares" in the Sun may be related to the annihilation events which inevitably occur in the solar atmosphere within this dark matter scenario.

  13. Thermoluminescent monitoring of the solar ultraviolet radiation with KCl: Eu2+ crystals

    International Nuclear Information System (INIS)

    Chernov, V.; Melendrez, R.; Barboza F, M.

    2000-01-01

    In this work it has been investigating the Tl properties of KCl: Eu 2+ subjected to solar direct radiation. Also it was realized irradiation with the Deuterium and Xenon lamps. It was used a set of filters and a Katos monochromator 0.25 M to determine the spectral response to Tl peaks and a study of them with respect to the duration of the Sun irradiation. After of the Sun irradiation the Tl curves show several peaks between the ambient temperature and 673 K. The relation between peaks depends strongly of the irradiation time and the different solar light wavelength. It is possible to divide the Tl peaks in two groups. The first one (T 473 K) is not too sensitive but is more stable under optical whitening. Here the obtained results are discussed with respect to UV dosemeters development for environment which facilitate to obtain direct measurements of the UV index. (Author)

  14. Effect of solar radiation and predacious microorganisms on survival of fecal and other bacteria.

    OpenAIRE

    McCambridge, J; McMeekin, T A

    1981-01-01

    The effect of solar radiation and predacious microorganisms on the survival of bacteria of fecal and plant origin was studied. The decline in the numbers of Escherichia coli cells in estuarine water samples was found to be significantly greater in the presence of both naturally occurring microbial predators and solar radiation than when each of these factors was acting independently. The effect of solar radiation on microbial predators was negligible, whereas the susceptibility of bacteria to...

  15. The relationship between incoming solar radiation and daily air temperature

    International Nuclear Information System (INIS)

    Kpeglo, Daniel Kwasi

    2013-07-01

    Solar radiation is the ultimate source of energy for the planet. To predict the values of temperature and instant solar radiation when equipment are not readily available from obtained equations, a good knowledge and understanding of the disposition and distribution of solar radiation is a requirement for modelling earth’s weather and climate change variables. A pyranometer (CM3) in series with a PHYWE amplifier and a voltmeter were experimentally set-up and used to study the amount of solar radiation received at the Physics Department of the University of Ghana during the day. The temperature of the study area as well as the Relative Humidity was also recorded. Data was collected over a period of one month (from 2nd to 24th April, 2012). Days for which rain was recorded were ignored because rain could damage the pyranometer. The data obtained by the set-up were therefore used to compare with data obtained by a wireless weather station (Davis Vintage Pro). The data from these separate set-ups indicated that a perfect correlation existed between the solar radiation and temperature of the place. The data obtained by the experimental set-up was split into two separate sessions as morning and evening sessions. It was observed that the experimental set-up had a good correlation with that of the weather station on a particular day 11th April, 2012. The various Regression Coefficient (R"2) values for morning session were respectively R"2 = 0.96 and R"2 = 0.95 with their respective equations as I_W =136.22T_W - 40623 and I_p = 2.3198T_p - 678.14. The evening session also had good Regression Coefficient values of R"2 = 0.81 and R"2 = 0.97 with equations of 2.1098T_p - 625 and I_W = 161.31T_w - 4876.9. Similar analysis of the data from the separate set-ups gave a better correlation for that of the experimental set-up than that of the wireless station. The range of values of Regression Coefficient (R"2) for the experimental set-up was between 0.82 − 0.99 for the morning

  16. Performance Evaluation of Radiation Sensors for the Solar Energy Sector

    Directory of Open Access Journals (Sweden)

    Laurent Vuilleumier

    2017-11-01

    Full Text Available Rotating Shadowband Irradiometers (RSI and SPN1 Sunshine Pyranometers allow determining the diffuse and direct components of solar radiation without sun trackers; they can be deployed in networks for continuous field operation with modest maintenance. Their performances are evaluated here by analyzing their errors with respect to well characterized references. The analysis is based on 1‑minute data recorded over a 15‑month period at the Payerne BSRN station in Switzerland. The analysis was applied both to the whole dataset and data subsets reflecting particular conditions to allow a better understanding of how instrument performance depends on such conditions.The overall performance for measuring global horizontal irradiance (GHI is satisfactory with deviations compatible with an expanded uncertainty of ±25 Wm−2 (±10 %. For diffuse horizontal irradiance (DfHI, RSIs exhibited errors on the order of ±20 Wm−2 (±13 % with some of them being affected by small systematic negative biases on the order of −5 Wm−2 (median. SPN1s underestimate DfHI by about −10 Wm−2 (median with a relatively large range of the expanded error distribution between −45 Wm−2 and 20 Wm−2 (−35 % to 13 %. For direct normal irradiance (DNI, the extended error range for RSIs is on the order of ±40 Wm−2 (±5–6 % with some instruments presenting no bias while others are affected by median biases up to −15 Wm−2. SPN1s exhibit a relatively large median bias of 40 Wm−2, and an extended range of the error distribution between −45 Wm−2 and 125 Wm−2 (−6 % to 19 %. Typical errors on the integrated yearly energy per unit surface area are on the order of a few percent or less (< 5 % for RSI with negligible errors on DNI for some RSI instruments. SPN1 integrated errors are negligible for GHI, but on the order of −8 % for DfHI, and between 9 % and 11 % for DNI.For RSIs, GHI and DfHI errors showed

  17. A Generalized Approach to Model the Spectra and Radiation Dose Rate of Solar Particle Events on the Surface of Mars

    Science.gov (United States)

    Guo, Jingnan; Zeitlin, Cary; Wimmer-Schweingruber, Robert F.; McDole, Thoren; Kühl, Patrick; Appel, Jan C.; Matthiä, Daniel; Krauss, Johannes; Köhler, Jan

    2018-01-01

    For future human missions to Mars, it is important to study the surface radiation environment during extreme and elevated conditions. In the long term, it is mainly galactic cosmic rays (GCRs) modulated by solar activity that contribute to the radiation on the surface of Mars, but intense solar energetic particle (SEP) events may induce acute health effects. Such events may enhance the radiation level significantly and should be detected as immediately as possible to prevent severe damage to humans and equipment. However, the energetic particle environment on the Martian surface is significantly different from that in deep space due to the influence of the Martian atmosphere. Depending on the intensity and shape of the original solar particle spectra, as well as particle types, the surface spectra may induce entirely different radiation effects. In order to give immediate and accurate alerts while avoiding unnecessary ones, it is important to model and well understand the atmospheric effect on the incoming SEPs, including both protons and helium ions. In this paper, we have developed a generalized approach to quickly model the surface response of any given incoming proton/helium ion spectra and have applied it to a set of historical large solar events, thus providing insights into the possible variety of surface radiation environments that may be induced during SEP events. Based on the statistical study of more than 30 significant solar events, we have obtained an empirical model for estimating the surface dose rate directly from the intensities of a power-law SEP spectra.

  18. The response of solar radiation in Jubail, Saudi Arabia, to smoke from oil field fires in Kuwait

    Science.gov (United States)

    Riley, James J.; Hicks, Neal G.; Thompson, T. Lewis

    1992-09-01

    The relative monthly solar radiation in Jubail Industrial City, Saudi Arabia (300 km southeast of Kuwait City) was reduced to 75% of the recent 10-year mean value by the torching of the first 50 of many oil wells and production facilities in Kuwait in mid-January 1991. The value was reduced further when an additional 600 wells were ignited in late February. Solar radiation continued at 55 65% of normal levels during March to August, when 341 oil wells were still burning. Recovery was rapid as the fires in oil fields located directly upwind of Jubail were extinguished, with the solar radiation reaching 95% of the long-term mean in October.

  19. The Energy Under Our Feet: A Study of Solar Radiation

    Science.gov (United States)

    Weiss, I.

    2016-12-01

    In this experiment I tested if asphalt pavement can produce enough solar heat to produce energy through a system that uses water, solar energy and heat. A setup that can conserve the water and prevent it from evaporating, as well as measuring the energy production is required to run this experiment. I have done a lot of research on this experiment and found that there are several variables that impact the results of this experiment. 1. The surface temperature compared to the air temperature 2. The Geographical location of the pavement 3. The time of the year 4. Cloud coverage for the day Overall there will be many variables I will have to keep out of the experiment such as temperature ranges, season changes and geographical location. My constant will be my location at 33.7086o North and 117.9564o West. Asphalt pavements do not reflect the sunlight and hence heat up faster than a light surface that would reflect the sunlight. This means the Asphalt absorbs the solar radiation, which increases the temperature of the air around the asphalt contributing to what is known as the urban heat island effect. This heating in turn contributes to the formation of smog and ozone products. With the population still growing this would also mean an increase in this temperature and hence an increase in smog and ozone, creating a significant health concern. Cities need to start looking at ways to cool their pavement and find ways to harvest the energy created by their streets. Installing pipes with water can provide that solution and not only reduce the heat reflected from the pavement but also harvest energy from this setup, and decrease the smog production and maintain a balance in ozone levels. As well as the asphalt needed to run the testing, a Stirling engine is required. A Stirling Engine is a highly efficient engine that can run on a variety of heat sources. Because it is highly compatible with alternative energy and renewable energy sources it could become increasingly

  20. Estimation and analysis of spectral solar radiation over Cairo

    International Nuclear Information System (INIS)

    Abdel Wahab, M.M.; Omran, M.

    1994-05-01

    This work presents a methodology to estimate spectral diffuse and global radiation on horizontal surface. This method is validated by comparing with measured direct and global spectral radiation in four bands. The results show a good performance in cloudless conditions. The analysis of the ratio of surface values to extraterrestrial ones revealed an over-all depletion in the summer months. Also there was no evidence for any tendency for conversion of radiational components through different bands. The model presents excellent agreement with the measured values for (UV/G) ratio. (author). 7 refs, 4 figs, 3 tabs

  1. Determination of incoming solar radiation in major tree species in Turkey.

    Science.gov (United States)

    Yilmaz, Osman Yalcin; Sevgi, Orhan; Koc, Ayhan

    2012-07-01

    Light requirements and spatial distribution of major forest tree species in Turkey hasn't been analyzed yet. Continuous surface solar radiation data, especially at mountainous-forested areas, are needed to put forward this relationship between forest tree species and solar radiation. To achieve this, GIS-based modeling of solar radiation is one of the methods used in rangelands to estimate continuous surface solar radiation. Therefore, mean monthly and annual total global solar radiation maps of whole Turkey were computed spatially using GRASS GIS software "r.sun" model under clear-sky (cloudless) conditions. 147498 pure forest stand point-based data were used in the study for calculating mean global solar radiation values of all the major forest tree species of Turkey. Beech had the lowest annual mean total global solar radiation value of 1654.87 kWh m(-2), whereas juniper had the highest value of 1928.89 kWh m(-2). The rank order of tree species according to the mean monthly and annual total global solar radiation values, using a confidence level of p solar radiation values of sites and light requirements of forest trees ranked similarly.

  2. Performance of Sayigh's universal formula in the estimation of global solar radiation in Ghana

    International Nuclear Information System (INIS)

    Oduro Afriyie, K.

    1995-10-01

    The performance of Sayigh's universal formula for the estimation of global solar radiation is tested against that of Angstrom-Black model for 13 stations in Ghana, using monthly mean daily global solar radiation averaged over the years 1957-1981. Sayigh's model is found not to perform as credibility as the Angstrom-Black model in the estimation of monthly global solar radiation in Ghana. Of the 156 values of monthly global solar radiation estimated by Sayigh's model, 123 (or 78.8%) had discrepancies of more than 10% with the measured values. The corresponding value for the Angstrom-Black model was 7 (or 4.5%). (author). 5 refs

  3. Effect of working fluids on the performance of a novel direct vapor generation solar organic Rankine cycle system

    International Nuclear Information System (INIS)

    Li, Jing; Alvi, Jahan Zeb; Pei, Gang; Ji, Jie; Li, Pengcheng; Fu, Huide

    2016-01-01

    Highlights: • A novel, flexible direct vapor generation solar ORC is proposed. • Technical feasibility of the system is discussed. • Fluid effect on collector efficiency is explored. • The system is more efficient than solar ORC with HTF. - Abstract: A novel solar organic Rankine cycle (ORC) system with direct vapor generation (DVG) is proposed. A heat storage unit is embedded in the ORC to guarantee the stability of power generation. Compared with conventional solar ORCs, the proposed system avoids the secondary heat transfer intermediate and shows good reaction to the fluctuation of solar radiation. The technical feasibility of the system is discussed. Performance is analyzed by using 17 dry and isentropic working fluids. Fluid effects on the efficiencies of ORC, collectors and the whole system are studied. The results indicate that the collector efficiency generally decreases while the ORC and system efficiencies increase with the increment in fluid critical temperature. At evaporation temperature of 120 °C and solar radiation of 800 Wm −2 , the ORC, collector and overall thermal efficiencies of R236fa are 10.59, 56.14 and 5.08% while their values for Benzene are 12.5, 52.58 and 6.57% respectively. The difference between collector efficiencies using R236fa and Benzene gets larger at lower solar radiation. The heat collection is strongly correlated with latent and sensible heat of the working fluid. Among the fluids, R123 exhibits the highest overall performance and seems to be suitable for the proposed system in the short term.

  4. A possible radiation-resistant solar cell geometry using superlattices

    Science.gov (United States)

    Goradia, C.; Clark, R.; Brinker, D.

    1985-01-01

    A solar cell structure is proposed which uses a GaAs nipi doping superlattice. An important feature of this structure is that photogenerated minority carriers are very quickly collected in a time shorter than bulk lifetime in the fairly heavily doped n and p layers and these carriers are then transported parallel to the superlattice layers to selective ohmic contacts. Assuming that these already-separated carriers have very long recombination lifetimes, due to their across an indirect bandgap in real space, it is argued that the proposed structure may exhibit superior radiation tolerance along with reasonably high beginning-of-life efficiency.

  5. Evaluation of different models to estimate the global solar radiation on inclined surface

    Science.gov (United States)

    Demain, C.; Journée, M.; Bertrand, C.

    2012-04-01

    Global and diffuse solar radiation intensities are, in general, measured on horizontal surfaces, whereas stationary solar conversion systems (both flat plate solar collector and solar photovoltaic) are mounted on inclined surface to maximize the amount of solar radiation incident on the collector surface. Consequently, the solar radiation incident measured on a tilted surface has to be determined by converting solar radiation from horizontal surface to tilted surface of interest. This study evaluates the performance of 14 models transposing 10 minutes, hourly and daily diffuse solar irradiation from horizontal to inclined surface. Solar radiation data from 8 months (April to November 2011) which include diverse atmospheric conditions and solar altitudes, measured on the roof of the radiation tower of the Royal Meteorological Institute of Belgium in Uccle (Longitude 4.35°, Latitude 50.79°) were used for validation purposes. The individual model performance is assessed by an inter-comparison between the calculated and measured solar global radiation on the south-oriented surface tilted at 50.79° using statistical methods. The relative performance of the different models under different sky conditions has been studied. Comparison of the statistical errors between the different radiation models in function of the clearness index shows that some models perform better under one type of sky condition. Putting together different models acting under different sky conditions can lead to a diminution of the statistical error between global measured solar radiation and global estimated solar radiation. As models described in this paper have been developed for hourly data inputs, statistical error indexes are minimum for hourly data and increase for 10 minutes and one day frequency data.

  6. Forecasting solar radiation using an optimized hybrid model by Cuckoo Search algorithm

    International Nuclear Information System (INIS)

    Wang, Jianzhou; Jiang, He; Wu, Yujie; Dong, Yao

    2015-01-01

    Due to energy crisis and environmental problems, it is very urgent to find alternative energy sources nowadays. Solar energy, as one of the great potential clean energies, has widely attracted the attention of researchers. In this paper, an optimized hybrid method by CS (Cuckoo Search) on the basis of the OP-ELM (Optimally Pruned Extreme Learning Machine), called CS-OP-ELM, is developed to forecast clear sky and real sky global horizontal radiation. First, MRSR (Multiresponse Sparse Regression) and LOO-CV (leave-one-out cross-validation) can be applied to rank neurons and prune the possibly meaningless neurons of the FFNN (Feed Forward Neural Network), respectively. Then, Direct strategy and Direct-Recursive strategy based on OP-ELM are introduced to build a hybrid model. Furthermore, CS (Cuckoo Search) optimized algorithm is employed to determine the proper weight coefficients. In order to verify the effectiveness of the developed method, hourly solar radiation data from six sites of the United States has been collected, and methods like ARMA (Autoregression moving average), BP (Back Propagation) neural network and OP-ELM can be compared with CS-OP-ELM. Experimental results show the optimized hybrid method CS-OP-ELM has the best forecasting performance. - Highlights: • An optimized hybrid method called CS-OP-ELM is proposed to forecast solar radiation. • CS-OP-ELM adopts multiple variables dataset as input variables. • Direct and Direct-Recursive strategy are introduced to build a hybrid model. • CS (Cuckoo Search) algorithm is used to determine the optimal weight coefficients. • The proposed method has the best performance compared with other methods

  7. Development of tool for optimization in the measurement of solar radiation; Desarrollo de herramientas para la optimizacion en la medicion de la radiacion solar

    Energy Technology Data Exchange (ETDEWEB)

    Adaro, J.; Quiroga, D.; Fasulo, A.; Lema, A.

    2004-07-01

    One of the most important requirements to make a project of rational use of solar energy is the precise knowledge of the temporal-spatial distribution of the solar resource on the terrestrial surface. For that reason, the Solar Energy Group at the National University of Rio Cuarto in Argentina, is measuring and recording data of global and direct solar radiation. Many possibilities of different kinds of errors there exist in this process, but the most significant problem is the lack of data. Then, it would be necessary to have a methodology that indicates what to do in this situation, and for that reason, this work performs an study about the data processing of the obtained measurements to infer values to be incorporated to the series in situations where the data are lost. To incorporate lost data, the Time Series Analysis based in spatial state models were used. (Author)

  8. The objectives of the directive on radiation protection for patients

    International Nuclear Information System (INIS)

    Courades, J.M.

    1992-01-01

    Improvement of the quality of medical uses of radiation and avoiding unnecessary exposure are the main objectives of the 1984 Directive laying down basic measures for the radiation protection of persons undergoing medical examination or treatment. This paper explains how these goals have been achieved through the implementation of the various provisions of the Community act since its adoption

  9. The objectives of the Directive on radiation protection for patients

    International Nuclear Information System (INIS)

    Courades, J.M.

    1992-01-01

    Improvement of the quality of medical uses of radiation and avoiding unnecessary exposure are the main objectives of the 1984 Directive laying down basic measures for the radiation protection of persons undergoing medical examination or treatment. This paper explains how these goals have been achieved through the implementation of the various provisions of the Community act since its adoption. (author)

  10. Efficient Radiation Shielding Through Direct Metal Laser Sintering

    Data.gov (United States)

    National Aeronautics and Space Administration — We have developed a method for efficient component-level radiation shielding that can be printed by direct metal laser sintering (DMLS) from files generated by the...

  11. Share of erythema dose of solar radiation in high mountains

    International Nuclear Information System (INIS)

    Blumthaler, M.; Ambach, W.

    1987-01-01

    The erythema dose was measured using a Robertson-Berger Sunburn Meter. The spectral sensitivity of the detector is adapted to an erythema action spectrum with the optical center at about 300 nm. The erythema dose is expressed in the biologically relevant Sunburn Units (SU). The Robertson-Berger Sunburn Meter has been recommended by the WMO for global monitoring of solar UV-B erythema dose. UV-A radiation was measured with a UV-radiometer. The spectral sensitivity of the detector has a flat maximum at 345 nm and a half band width of +- 25 nm. Global radiation was measured using a pyranometer. All detectors were placed horizontally and calibrated several times. Readings were taken in intervals of one minute

  12. Radiation resistance of amorphous silicon alloy solar cells

    International Nuclear Information System (INIS)

    Hanak, J.J.; Chen, E.; Myatt, A.; Woodyard, J.R.

    1987-01-01

    The radiation resistance of a-Si alloy solar cells when bombarded by high energy particles is reviewed. The results of investigations of high energy proton radiation resistance of a-Si alloy thin film photovoltaic cells are reported. Irradiations were carried out with 200 keV and 1.00 MeV protons with fluences ranging betweeen 1E11 and 1E15 cm-2. Defect generation and passivation mechanisms were studied using the AM1 conversion efficiency and isochronal anneals. It is concluded that the primary defect generation mechanism results from the knock-on of Si and Ge in the intrinsic layer of the cells. The defect passivation proceeds by the complex annealing of Si and Ge defects and not by the simple migration of hydrogen

  13. Impact of Solar Radiation on Gene Expression in Bacteria

    Directory of Open Access Journals (Sweden)

    Sabine Matallana-Surget

    2013-07-01

    Full Text Available Microorganisms often regulate their gene expression at the level of transcription and/or translation in response to solar radiation. In this review, we present the use of both transcriptomics and proteomics to advance knowledge in the field of bacterial response to damaging radiation. Those studies pertain to diverse application areas such as fundamental microbiology, water treatment, microbial ecology and astrobiology. Even though it has been demonstrated that mRNA abundance is not always consistent with the protein regulation, we present here an exhaustive review on how bacteria regulate their gene expression at both transcription and translation levels to enable biomarkers identification and comparison of gene regulation from one bacterial species to another.

  14. Radiation protection office at the general direction of health

    International Nuclear Information System (INIS)

    Piechowski, J.

    1996-01-01

    The radiation protection office at the general direction of health has the following functions: organisation and relations with decentralized services, legal aspects, relations with the direction of nuclear installation safety, nuclear medicine with licensing, radioactive wastes in relation with ANDRA, environment, trusteeship of OPRI in matter of measurements, dosimetry and epidemiology in relation with the Minister of work and training in radiation protection. (N.C.)

  15. Evaluating solar radiation on a tilted surfaces - a study case in Timis (Romania)

    International Nuclear Information System (INIS)

    Vasar, C; Prostean, O; Prostean, G

    2016-01-01

    In the last years the usage of solar energy has grown considerably in Romania, as well as in Europe, stimulated by various factors as government programs, green pricing policies, decreasing of photovoltaic components cost etc. Also, the rising demand of using Solar Energy Conversion Systems (SECS) is driven by the desire of individuals or companies to obtain energy from a clean renewable source. In many applications, remote consumers far from other energetic grids can use solar systems more cost-effectively than extending the grid to reach the location. Usually the solar energy is measured or forecast on horizontal surface, but in SECS there is needed the total solar radiation incident on the collector surface, that is oriented in a position that maximize the harvested energy. There are many models that convert the solar radiation from horizontal surface to a tilted surface, but they use empirical coefficients and the accuracy is influenced by different facts as geographical location or sky conditions. Such models were used considering measured values for solar radiation on horizontal plane, in the western part of Romania. Hourly values measured for global solar irradiation on the horizontal plane, diffuse solar irradiation on the horizontal plane and reflected solar irradiation by ground are used to compute the total solar radiation incident on different tilted surfaces. The calculated incident radiation is then compared with the real radiation measured on tilted surface in order to evaluate the performance of the considered conversion models. (paper)

  16. Effects of solar PAR and UV radiation on tropical biofouling communities

    KAUST Repository

    Dobretsov, SV; Gosselin, L; Qian, P

    2010-01-01

    We investigated the effect of solar ultraviolet radiation (UVR) and photosynthetically active radiation (PAR) on the development of tropical micro- and macrofouling communities for 30 d. The experimental design involved 3 treatments: full spectrum

  17. A radiative transfer module for calculating photolysis rates and solar heating in climate models: Solar-J v7.5

    Science.gov (United States)

    Hsu, Juno; Prather, Michael J.; Cameron-Smith, Philip; Veidenbaum, Alex; Nicolau, Alex

    2017-07-01

    Solar-J is a comprehensive radiative transfer model for the solar spectrum that addresses the needs of both solar heating and photochemistry in Earth system models. Solar-J is a spectral extension of Cloud-J, a standard in many chemical models that calculates photolysis rates in the 0.18-0.8 µm region. The Cloud-J core consists of an eight-stream scattering, plane-parallel radiative transfer solver with corrections for sphericity. Cloud-J uses cloud quadrature to accurately average over correlated cloud layers. It uses the scattering phase function of aerosols and clouds expanded to eighth order and thus avoids isotropic-equivalent approximations prevalent in most solar heating codes. The spectral extension from 0.8 to 12 µm enables calculation of both scattered and absorbed sunlight and thus aerosol direct radiative effects and heating rates throughout the Earth's atmosphere.The Solar-J extension adopts the correlated-k gas absorption bins, primarily water vapor, from the shortwave Rapid Radiative Transfer Model for general circulation model (GCM) applications (RRTMG-SW). Solar-J successfully matches RRTMG-SW's tropospheric heating profile in a clear-sky, aerosol-free, tropical atmosphere. We compare both codes in cloudy atmospheres with a liquid-water stratus cloud and an ice-crystal cirrus cloud. For the stratus cloud, both models use the same physical properties, and we find a systematic low bias of about 3 % in planetary albedo across all solar zenith angles caused by RRTMG-SW's two-stream scattering. Discrepancies with the cirrus cloud using any of RRTMG-SW's three different parameterizations are as large as about 20-40 % depending on the solar zenith angles and occur throughout the atmosphere.Effectively, Solar-J has combined the best components of RRTMG-SW and Cloud-J to build a high-fidelity module for the scattering and absorption of sunlight in the Earth's atmosphere, for which the three major components - wavelength integration, scattering, and

  18. A radiative transfer module for calculating photolysis rates and solar heating in climate models: Solar-J v7.5

    Directory of Open Access Journals (Sweden)

    J. Hsu

    2017-07-01

    Full Text Available Solar-J is a comprehensive radiative transfer model for the solar spectrum that addresses the needs of both solar heating and photochemistry in Earth system models. Solar-J is a spectral extension of Cloud-J, a standard in many chemical models that calculates photolysis rates in the 0.18–0.8 µm region. The Cloud-J core consists of an eight-stream scattering, plane-parallel radiative transfer solver with corrections for sphericity. Cloud-J uses cloud quadrature to accurately average over correlated cloud layers. It uses the scattering phase function of aerosols and clouds expanded to eighth order and thus avoids isotropic-equivalent approximations prevalent in most solar heating codes. The spectral extension from 0.8 to 12 µm enables calculation of both scattered and absorbed sunlight and thus aerosol direct radiative effects and heating rates throughout the Earth's atmosphere.The Solar-J extension adopts the correlated-k gas absorption bins, primarily water vapor, from the shortwave Rapid Radiative Transfer Model for general circulation model (GCM applications (RRTMG-SW. Solar-J successfully matches RRTMG-SW's tropospheric heating profile in a clear-sky, aerosol-free, tropical atmosphere. We compare both codes in cloudy atmospheres with a liquid-water stratus cloud and an ice-crystal cirrus cloud. For the stratus cloud, both models use the same physical properties, and we find a systematic low bias of about 3 % in planetary albedo across all solar zenith angles caused by RRTMG-SW's two-stream scattering. Discrepancies with the cirrus cloud using any of RRTMG-SW's three different parameterizations are as large as about 20–40 % depending on the solar zenith angles and occur throughout the atmosphere.Effectively, Solar-J has combined the best components of RRTMG-SW and Cloud-J to build a high-fidelity module for the scattering and absorption of sunlight in the Earth's atmosphere, for which the three major components – wavelength

  19. Estimation of daily global solar radiation as a function of the solar energy potential at soil surface

    International Nuclear Information System (INIS)

    Pereira, A.B.; Vrisman, A.L.; Galvani, E.

    2002-01-01

    The solar radiation received at the surface of the earth, apart from its relevance to several daily human activities, plays an important role in the growth and development of plants. The aim of the current work was to develop and gauge an estimation model for the evaluation of the global solar radiation flux density as a function of the solar energy potential at soil surface. Radiometric data were collected at Ponta Grossa, PR, Brazil (latitude 25°13' S, longitude 50°03' W, altitude 880 m). Estimated values of solar energy potential obtained as a function of only one measurement taken at solar noon time were confronted with those measured by a Robitzsch bimetalic actinograph, for days that presented insolation ratios higher than 0.85. This data set was submitted to a simple linear regression analysis, having been obtained a good adjustment between observed and calculated values. For the estimation of the coefficients a and b of Angström's equation, the method based on the solar energy potential at soil surface was used for the site under study. The methodology was efficient to assess the coefficients, aiming at the determination of the global solar radiation flux density, whith quickness and simplicity, having also found out that the criterium for the estimation of the solar energy potential is equivalent to that of the classical methodology of Angström. Knowledge of the available solar energy potential and global solar radiation flux density is of great importance for the estimation of the maximum atmospheric evaporative demand, of water consumption by irrigated crops, and also for building solar engineering equipment, such as driers, heaters, solar ovens, refrigerators, etc [pt

  20. Natural Antioxidants: Multiple Mechanisms to Protect Skin From Solar Radiation

    Directory of Open Access Journals (Sweden)

    Spencer Dunaway

    2018-04-01

    Full Text Available Human skin exposed to solar ultraviolet radiation (UVR results in a dramatic increase in the production of reactive oxygen species (ROS. The sudden increase in ROS shifts the natural balance toward a pro-oxidative state, resulting in oxidative stress. The detrimental effects of oxidative stress occur through multiple mechanisms that involve alterations to proteins and lipids, induction of inflammation, immunosuppression, DNA damage, and activation of signaling pathways that affect gene transcription, cell cycle, proliferation, and apoptosis. All of these alterations promote carcinogenesis and therefore, regulation of ROS levels is critical to the maintenance of normal skin homeostasis. Several botanical products have been found to exhibit potent antioxidant capacity and the ability to counteract UV-induced insults to the skin. These natural products exert their beneficial effects through multiple pathways, including some known to be negatively affected by solar UVR. Aging of the skin is also accelerated by UVR exposure, in particular UVA rays that penetrate deep into the epidermis and the dermis where it causes the degradation of collagen and elastin fibers via oxidative stress and activation of matrix metalloproteinases (MMPs. Because natural compounds are capable of attenuating some of the UV-induced aging effects in the skin, increased attention has been generated in the area of cosmetic sciences. The focus of this review is to cover the most prominent phytoproducts with potential to mitigate the deleterious effects of solar UVR and suitability for use in topical application.

  1. Effects of solar radiation on the orbits of small particles

    Science.gov (United States)

    Lyttleton, R. A.

    1976-01-01

    A modification of the Robertson (1937) equations of particle motion in the presence of solar radiation is developed which allows for partial reflection of sunlight as a result of rapid and varying particle rotations caused by interaction with the solar wind. The coefficients and forces in earlier forms of the equations are compared with those in the present equations, and secular rates of change of particle orbital elements are determined. Orbital dimensions are calculated in terms of time, probable sizes and densities of meteoric and cometary particles are estimated, and times of infall to the sun are computed for a particle moving in an almost circular orbit and a particle moving in an elliptical orbit of high eccentricity. Changes in orbital elements are also determined for particles from a long-period sun-grazing comet. The results show that the time of infall to the sun from a highly eccentric orbit is substantially shorter than from a circular orbit with a radius equal to the mean distance in the eccentric orbit. The possibility is considered that the free orbital kinetic energy of particles drawn into the sun may be the energy source for the solar corona.

  2. Statistical analysis of solar radiation on variously oriented sloping surfaces

    International Nuclear Information System (INIS)

    Garg, H.P.; Garg, S.N.

    1985-12-01

    For four years, daily global radiation on a south facing surface and on four vertical walls namely south wall, north wall, east wall and west wall, has been computed and statistically analysed for each of the 4 stations: New Delhi, Calcutta, Poona and Madras. Daily direct radiation at normal incidence at New Delhi has also been studied. It has been found that maximum global radiation is 30 MJ/m 2 /day for a south facing tilted surface, 21 MJ/m 2 /day for a south wall, 18 MJ/m 2 /day for an east west wall and 12 MJ/m 2 /day for a north wall. Maximum direct radiation at normal incidence at New Delhi is also 30 MJ/m 2 /day. For a south facing tilted surface, nearly 80% of the days have energy between 21-27 MJ/m 2 /day. Atmospheric transmittance for direct radiation is seen to vary from 20% in July to 52% in November

  3. Solar power conversion system with directionally- and spectrally-selective properties based on a reflective cavity

    Science.gov (United States)

    Boriskina, Svetlana; Kraemer, Daniel; McEnaney, Kenneth; Weinstein, Lee A.; Chen, Gang

    2018-03-13

    Solar power conversion system. The system includes a cavity formed within an enclosure having highly specularly reflecting in the IR spectrum inside walls, the enclosure having an opening to receive solar radiation. An absorber is positioned within the cavity for receiving the solar radiation resulting in heating of the absorber structure. In a preferred embodiment, the system further contains an energy conversion and storage devices thermally-linked to the absorber by heat conduction, convection, far-field or near-field thermal radiation.

  4. Long Term Solar Radiation Forecast Using Computational Intelligence Methods

    Directory of Open Access Journals (Sweden)

    João Paulo Coelho

    2014-01-01

    Full Text Available The point prediction quality is closely related to the model that explains the dynamic of the observed process. Sometimes the model can be obtained by simple algebraic equations but, in the majority of the physical systems, the relevant reality is too hard to model with simple ordinary differential or difference equations. This is the case of systems with nonlinear or nonstationary behaviour which require more complex models. The discrete time-series problem, obtained by sampling the solar radiation, can be framed in this type of situation. By observing the collected data it is possible to distinguish multiple regimes. Additionally, due to atmospheric disturbances such as clouds, the temporal structure between samples is complex and is best described by nonlinear models. This paper reports the solar radiation prediction by using hybrid model that combines support vector regression paradigm and Markov chains. The hybrid model performance is compared with the one obtained by using other methods like autoregressive (AR filters, Markov AR models, and artificial neural networks. The results obtained suggests an increasing prediction performance of the hybrid model regarding both the prediction error and dynamic behaviour.

  5. A solar radiation model for use in climate studies

    Science.gov (United States)

    Chou, Ming-Dah

    1992-01-01

    A solar radiation routine is developed for use in climate studies that includes absorption and scattering due to ozone, water vapor, oxygen, carbon dioxide, clouds, and aerosols. Rayleigh scattering is also included. Broadband parameterization is used to compute the absorption by water vapor in a clear atmosphere, and the k-distribution method is applied to compute fluxes in a scattering atmosphere. The reflectivity and transmissivity of a scattering layer are computed analytically using the delta-four-stream discrete-ordinate approximation. The two-stream adding method is then applied to compute fluxes for a composite of clear and scattering layers. Compared to the results of high spectral resolution and detailed multiple-scattering calculations, fluxes and heating rate are accurately computed to within a few percent. The high accuracy of the flux and heating-rate calculations is achieved with a reasonable amount of computing time. With the UV and visible region grouped into four bands, this solar radiation routine is useful not only for climate studies but also for studies on photolysis in the upper atmosphere and photosynthesis in the biosphere.

  6. Mechanism on radiation degradation of Si space solar cells

    International Nuclear Information System (INIS)

    Yamaguchi, Masafumi; Taylor, S.J.; Hisamatsu, Tadashi; Matsuda, Sumio

    1998-01-01

    Radiation testing of Si n + -p-p + structure space solar cells has revealed an anomalous increase in short-circuit current Isc, followed by an abrupt decrease and cell failure, induced by high fluence electron and proton irradiations. A model to explain these phenomena by expressing the change in carrier concentration p of the base region is proposed in addition to the well-known model where Isc is decreased by minority-carrier lifetime reduction with irradiation. Change in carrier concentration causes broadening the depletion layer to contribute increase in the generated photocurrent and increase in recombination-generation current in the depletion layer, and increase in the resistivity of the base layer to result in the abrupt decrease of Isc and failure of the solar cell. Type conversion from p-type to n-type in base layer has been confirmed by EBIC (electron-beam induced current) and spectral response measurements. Moreover, origins of radiation-induced defects in heavily irradiated Si and generation of deep donor defects have also been examined by using DLTS (deep level transient spectroscopy) analysis. (author)

  7. Effectiveness estimation of camouflage measures with solar radiation and longwave radiation considered

    Energy Technology Data Exchange (ETDEWEB)

    Jung, J.S. [LG Electronics Corporation (Korea); Kauh, S.K. [Seoul National University, Seoul (Korea); Yoo, H.S. [Soongsil University, Seoul (Korea)

    1998-11-01

    Camouflage measures in military purpose utilizes the apparent temperature difference between the target and background, so it is essential to develop thermal analysis program for apparent temperature predictions and to apply some camouflage measures to real military targets for camouflage purpose. In this study, a thermal analysis program including conduction, convection and radiation is developed and the validity of radiation heat transfer terms is examined. The results show that longwave radiation along with solar radiation should be included in order to predict apparent temperature as well as physical temperature exactly. Longwave emissivity variation as an effective camouflage measures is applied to a real M2 tank. From the simulation results, it is found that an effective surface treatment, such as painting of a less emissive material or camouflage, clothing, may provide a temperature similarity or a spatial similarity, resulting in an effective camouflage. (author). 12 refs., 6 figs., 1 tab.

  8. Ultraviolet radiation directly induces pigment production by cultured human melanocytes

    International Nuclear Information System (INIS)

    Friedmann, P.S.; Gilchrest, B.A.

    1987-01-01

    In humans the major stimulus for cutaneous pigmentation is ultraviolet radiation (UVR). Little is known about the mechanism underlying this response, in part because of the complexity of interactions in whole epidermis. Using a recently developed culture system, human melanocytes were exposed daily to a physiologic range of UVR doses from a solar simulator. Responses were determined 24 hours after the last exposure. There was a dose-related increase in melanin content per cell and uptake of 14 C-DOPA, accompanied by growth inhibition. Cells from donors of different racial origin gave proportionately similar increases in melanin, although there were approximately tenfold differences in basal values. Light and electron microscopy revealed UVR-stimulated increases in dendricity as well as melanosome number and degree of melanization, analogous to the well-recognized melanocyte changes following sun exposure of intact skin. Similar responses were seen with Cloudman S91 melanoma cells, although this murine cell line required lower UVR dosages and fewer exposures for maximal stimulation. These data establish that UVR is capable of directly stimulating melanogenesis. Because cyclic AMP elevation has been associated in some settings with increased pigment production by cultured melanocytes, preliminary experiments were conducted to see if the effects of UVR were mediated by cAMP. Both alpha-MSH and isobutylmethylxanthine (IBMX), as positive controls, caused a fourfold increase in cAMP level in human melanocytes and/or S91 cells, but following a dose of UVR sufficient to stimulate pigment production there was no change in cAMP level up to 4 hours after exposure. Thus, it appears that the UVR-induced melanogenesis is mediated by cAMP-independent mechanisms

  9. Models for the estimation of diffuse solar radiation for typical cities in Turkey

    International Nuclear Information System (INIS)

    Bakirci, Kadir

    2015-01-01

    In solar energy applications, diffuse solar radiation component is required. Solar radiation data particularly in terms of diffuse component are not readily affordable, because of high price of measurements as well as difficulties in their maintenance and calibration. In this study, new empirical models for predicting the monthly mean diffuse solar radiation on a horizontal surface for typical cities in Turkey are established. Therefore, fifteen empirical models from studies in the literature are used. Also, eighteen diffuse solar radiation models are developed using long term sunshine duration and global solar radiation data. The accuracy of the developed models is evaluated in terms of different statistical indicators. It is found that the best performance is achieved for the third-order polynomial model based on sunshine duration and clearness index. - Highlights: • Diffuse radiation is given as a function of clearness index and sunshine fraction. • The diffuse radiation is an important parameter in solar energy applications. • The diffuse radiation measurement is for limited periods and it is very rare. • The new models can be used to estimate monthly average diffuse solar radiation. • The accuracy of the models is evaluated on the basis of statistical indicators

  10. SOLAR RADIATION ESTIMATION ON BUILDING ROOFS AND WEB-BASED SOLAR CADASTRE

    Directory of Open Access Journals (Sweden)

    G. Agugiaro

    2012-07-01

    Full Text Available The aim of this study is the estimation of solar irradiance on building roofs in complex Alpine landscapes. Very high resolution geometric models of the building roofs are generated by means of advanced automated image matching methods. Models are combined with raster and vector data sources to estimate the incoming solar radiation hitting the roofs. The methodology takes into account for atmospheric effects, site latitude and elevation, slope and aspect of the terrain as well as the effects of shadows cast by surrounding buildings, chimneys, dormers, vegetation and terrain topography. An open source software solution has been developed and applied to a study area located in a mountainous site and containing some 1250 residential, commercial and industrial buildings. The method has been validated by data collected with a pyranometer and results made available through a prototype WebGIS platform.

  11. Concentrator photovoltaic module architectures with capabilities for capture and conversion of full global solar radiation

    Science.gov (United States)

    Lee, Kyu-Tae; Yao, Yuan; He, Junwen; Fisher, Brent; Sheng, Xing; Lumb, Matthew; Xu, Lu; Anderson, Mikayla A.; Scheiman, David; Han, Seungyong; Kang, Yongseon; Gumus, Abdurrahman; Bahabry, Rabab R.; Lee, Jung Woo; Paik, Ungyu; Bronstein, Noah D.; Alivisatos, A. Paul; Meitl, Matthew; Burroughs, Scott; Mustafa Hussain, Muhammad; Lee, Jeong Chul; Nuzzo, Ralph G.; Rogers, John A.

    2016-12-01

    Emerging classes of concentrator photovoltaic (CPV) modules reach efficiencies that are far greater than those of even the highest performance flat-plate PV technologies, with architectures that have the potential to provide the lowest cost of energy in locations with high direct normal irradiance (DNI). A disadvantage is their inability to effectively use diffuse sunlight, thereby constraining widespread geographic deployment and limiting performance even under the most favorable DNI conditions. This study introduces a module design that integrates capabilities in flat-plate PV directly with the most sophisticated CPV technologies, for capture of both direct and diffuse sunlight, thereby achieving efficiency in PV conversion of the global solar radiation. Specific examples of this scheme exploit commodity silicon (Si) cells integrated with two different CPV module designs, where they capture light that is not efficiently directed by the concentrator optics onto large-scale arrays of miniature multijunction (MJ) solar cells that use advanced III-V semiconductor technologies. In this CPV+ scheme (“+” denotes the addition of diffuse collector), the Si and MJ cells operate independently on indirect and direct solar radiation, respectively. On-sun experimental studies of CPV+ modules at latitudes of 35.9886° N (Durham, NC), 40.1125° N (Bondville, IL), and 38.9072° N (Washington, DC) show improvements in absolute module efficiencies of between 1.02% and 8.45% over values obtained using otherwise similar CPV modules, depending on weather conditions. These concepts have the potential to expand the geographic reach and improve the cost-effectiveness of the highest efficiency forms of PV power generation.

  12. Comparisons of solar radiation interception, albedo and net radiation as influenced by row orientations of crops

    International Nuclear Information System (INIS)

    Baten, Md.A.; Kon, H.

    1997-01-01

    Field experiments were conducted on soybean (Glycin max L.) in summer and potato (Solanum tuberosum L.) in autumn to evaluate the effect of row orientations of crops on some selected micro meteorological factors during 1994 and 1995. The intercepted solar radiation was the largest in the plants growing in bidirection in summer and it exhibited intermediate trend in autumn as compared to E-W or N-S row orientations. In summer, penetrated solar radiation between two plants and near the stem base of a N-S row was larger than that of E-W row. While in autumn, the observed solar radiation between two plants and near the stem base of a E-W row was markedly larger than that of N-S row. The area weighted mean of penetrated solar radiation was larger in E-W soybean rows but lower in potato rows as compared to N-S row orientations. Soil surface temperature between N-S potato rows was larger than that of E-W potato rows and the upper canopy surface temperature of potato was larger in E-W rows as compared to N-S rows. Net radiation observed over E-W potato rows was larger as compared to N-S potato rows but net radiation measured under canopy of E-W potato rows was smaller than that of in N-S rows. Net radiation measured over N-S soybean rows was larger than that of E-W soybean rows and it was smaller between N-S soybean rows when measured under canopy as compared to E-W rows. The albedo observed over potato was larger over E-W rows as compared to N-S rows. Albedos over soybean canopy showed opposite trend with the albedos observed over potato canopy. It was larger over N-S rows as compared to E-W rows. High harvest index was associated with larger interception of radiation. (author)

  13. Seasonal variation of solar radiation and underwater irradiance in the Seto inland sea

    International Nuclear Information System (INIS)

    Endo, T.; Matsuda, O.; Imabayashi, H.

    1983-01-01

    The recent rapid eutrophication of the coastal seas of Japan has had a remarkable effect on the turbidity and transparency of the sea water, hence on the attenuation of underwater irradiance, which in turn influences the phytoplankton communities and primary productivity of the area. The present study deals with the continuous three years observation of the total short-wave radiation, direct short-wave radiation, diffused short-wave radiation and photosynthetically active radiation of tlle Seto Inland Sea. Along with these observations, reflected short-wave radiation from the sea and transmitted short-wave radiation into the sea were determined. The availability of solar radiation for primary production, vertical distribution of spectral irradiance and attenuation coefficient were also discussed in relation to the optical water type of the region. 1. A typical seasonal variation in the monthly mean daily solar radiation (total short-wave radiation) was observed, with a maximal value of 17.0 MJ 2 in July and minimal values of 7.4 to 7.5 MJ 2 through November to January. 2. Seasonal variation of direct short-wave radiation was nearly identical to that of total short-wave radiation, with 9.3 MJ 2 at maximum and 4.1MJ 2 at minimum. Diffused short-wave radiation increased in June and decreased in January. The ratio of diffused short-wave radiation to total short-wave radiation ranged from 394000 62% with an average of 49%.0 3. Seasonal variation of photosynthetically active radiation was very similar to that of direct short-wave radiation, with values of 7.3 MJ 2 in July and of 3.3 MJ 2 in December 4. The albedo at the sea surface changed according to the incidence angle and surface conditions. Average daily values ranged from 2.9% on a fine summer day to 10% on an overcasted day in winter. 5. Underwater irradiance at a depth of 50cm varied widely according to such parameters as turbidity and the surface condition of the water. Observation revealed a remarkable decrease

  14. Spatial and Temporal Variabilities of Solar and Longwave Radiation Fluxes below a Coniferous Forest in the French Alps

    Science.gov (United States)

    Sicart, J. E.; Ramseyer, V.; Lejeune, Y.; Essery, R.; Webster, C.; Rutter, N.

    2017-12-01

    At high altitudes and latitudes, snow has a large influence on hydrological processes. Large fractions of these regions are covered by forests, which have a strong influence on snow accumulation and melting processes. Trees absorb a large part of the incoming shortwave radiation and this heat load is mostly dissipated as longwave radiation. Trees shelter the snow surface from wind, so sub-canopy snowmelt depends mainly on the radiative fluxes: vegetation attenuates the transmission of shortwave radiation but enhances longwave irradiance to the surface. An array of 13 pyranometers and 11 pyrgeometers was deployed on the snow surface below a coniferous forest at the CEN-MeteoFrance Col de Porte station in the French Alps (1325 m asl) during the 2017 winter in order to investigate spatial and temporal variabilities of solar and infrared irradiances in different meteorological conditions. Sky view factors measured with hemispherical photographs at each radiometer location were in a narrow range from 0.2 to 0.3. The temperature of the vegetation was measured with IR thermocouples and an IR camera. In clear sky conditions, the attenuation of solar radiation by the canopy reached 96% and its spatial variability exceeded 100 W m-2. Longwave irradiance varied by 30 W m-2 from dense canopy to gap areas. In overcast conditions, the spatial variabilities of solar and infrared irradiances were reduced and remained closely related to the sky view factor. A simple radiative model taking into account the penetration through the canopy of the direct and diffuse solar radiation, and isotropic infrared emission of the vegetation as a blackbody emitter, accurately reproduced the dynamics of the radiation fluxes at the snow surface. Model results show that solar transmissivity of the canopy in overcast conditions is an excellent proxy of the sky view factor and the emitting temperature of the vegetation remained close to the air temperature in this typically dense Alpine forest.

  15. Design and Fabrication of a Direct Natural Convection Solar Dryer for Tapioca

    Directory of Open Access Journals (Sweden)

    Diemuodeke E. OGHENERUONA

    2011-06-01

    Full Text Available Based on preliminary investigations under controlled conditions of drying experiments, a direct natural convection solar dryer was designed and fabricated to dry tapioca in the rural area. This paper describes the design considerations followed and presents the results of MS excel computed results of the design parameters. A minimum of 7.56 m2 solar collector area is required to dry a batch of 100 kg tapioca in 20 hours (two days drying period. The initial and final moisture content considered were 79 % and 10 % wet basis, respectively. The average ambient conditions are 32ºC air temperatures and 74 % relative humidity with daily global solar radiation incident on horizontal surface of 13 MJ/m2/day. The weather conditions considered are of Warri (lat. 5°30’, long. 5°41’, Nigeria. A prototype of the dryer so designed was fabricated with minimum collector area of 1.08 m2. This prototype dryer will be used in experimental drying tests under various loading conditions.

  16. Experimental investigation of simple solar radiation spectral model performances under a Mediterranean Algerian's climate

    International Nuclear Information System (INIS)

    Koussa, Mustapha; Saheb-Koussa, Djohra; Hadji, Seddik

    2017-01-01

    In this work, models are presented that, under cloudless atmosphere conditions, calculate solar spectral normal direct and horizontal diffuse irradiance. Based on different monochromatic transmission factors related to the main constituents of the atmosphere, the models evaluate the spectral irradiance between 0.29 and 4.0 μm. Absorption by water vapor, uniformly mixed gas, and ozone are considered as well as scattering by the atmospheric aerosols. Based on the equations relative to each one of the two retained models, a MATLAB program is developed to evaluate the spectral distribution of each solar irradiance component. Hence, the geographical coordinates of the site, and the monochromatic distribution of the extraterrestrial irradiance are used as input data. From three-year data measurement records made in Bouzareah site (temperate climate), thirty eight days characterized by a clear sky state have been selected from over different months of the year and the corresponding main meteorological parameters used as input parameters. So, because only the five-minute broadband data measurements are available, the modified numerical trapeze method is used to integrate the monochromatic curve values related to each solar irradiance component. Consequently, the precipitable water vapor amount, the Angstrom and Linke turbidity factors are evaluated and a multi-linear correlation relating the Linke turbidity factor to the precipitable water vapor and the Angstrom turbidity coefficient is established. Hence, according to the mean values of Linke and Angstrom turbidity factors and those of the precipitable water vapor, the site of Bouzareah is classified as a rural site. So, the effect of the main constituents of the atmosphere on the spectral distribution of solar irradiance is discussed and, it is also observed that the aerosol amount contained in the atmosphere affects most both of the diffuse and direct solar irradiance amount than that of the horizontal and inclined

  17. Broken-cloud enhancement of solar radiation absorption

    Energy Technology Data Exchange (ETDEWEB)

    Byrne, R.N. [Science Applications International Corporation, San Diego, CA (United States); Somerville, R.C. [Univ. of California, La Jolla, CA (United States); Subasilar, B. [Curtain Univ. of Technology, Perth (Australia)

    1996-04-01

    Two papers recently published in Science have shown that there is more absorption of solar radiation than estimated by current atmospheric general circulation models (GCMs) and that the discrepancy is associated with cloudy scenes. We have devised a simple model which explains this as an artifact of stochastic radiative transport. We first give a heuristic description, unencumbered by mathematical detail. Consider a simple case with clouds distributed at random within a single level whose upper and lower boundaries are fixed. The solar zenith angle is small to moderate; this is therefore an energetically important case. Fix the average areal liquid water content of the cloud layer, and take the statistics of the cloud distribution to be homogeneous within the layer. Furthermore, assume that all the clouds in the layer have the same liquid water content, constant throughout the cloud, and that apart from their droplet content they are identical to the surrounding clear sky. Let the clouds occupy on the average a fraction p{sub cld} of the volume of the cloudy layer, and let them have a prescribed distribution of sizes about some mean. This is not a fractal distribution, because it has a scale. Cloud shape is unimportant so long as cloud aspect ratios are not far from unity. Take the single-scattering albedo to be unity for the droplets in the clouds. All of the absorption is due to atmospheric gases, so the absorption coefficient at a point is the same for cloud and clear sky. Absorption by droplets is less than 10% effect in the numerical stochastic radiation calculations described below, so it is reasonable to neglect it at this level of idealization.

  18. The use of a sky camera for solar radiation estimation based on digital image processing

    International Nuclear Information System (INIS)

    Alonso-Montesinos, J.; Batlles, F.J.

    2015-01-01

    The necessary search for a more sustainable global future means using renewable energy sources to generate pollutant-free electricity. CSP (Concentrated solar power) and PV (photovoltaic) plants are the systems most in demand for electricity production using solar radiation as the energy source. The main factors affecting final electricity generation in these plants are, among others, atmospheric conditions; therefore, knowing whether there will be any change in the solar radiation hitting the plant's solar field is of fundamental importance to CSP and PV plant operators in adapting the plant's operation mode to these fluctuations. Consequently, the most useful technology must involve the study of atmospheric conditions. This is the case for sky cameras, an emerging technology that allows one to gather sky information with optimal spatial and temporal resolution. Hence, in this work, a solar radiation estimation using sky camera images is presented for all sky conditions, where beam, diffuse and global solar radiation components are estimated in real-time as a novel way to evaluate the solar resource from a terrestrial viewpoint. - Highlights: • Using a sky camera, the solar resource has been estimated for one minute periods. • The sky images have been processed to estimate the solar radiation at pixel level. • The three radiation components have been estimated under all sky conditions. • Results have been presented for cloudless, partially-cloudy and overcast conditions. • For beam and global radiation, the nRMSE value is of about 11% under overcast skies.

  19. The problem of multicollinearity in horizontal solar radiation estimation models and a new model for Turkey

    International Nuclear Information System (INIS)

    Demirhan, Haydar

    2014-01-01

    Highlights: • Impacts of multicollinearity on solar radiation estimation models are discussed. • Accuracy of existing empirical models for Turkey is evaluated. • A new non-linear model for the estimation of average daily horizontal global solar radiation is proposed. • Estimation and prediction performance of the proposed and existing models are compared. - Abstract: Due to the considerable decrease in energy resources and increasing energy demand, solar energy is an appealing field of investment and research. There are various modelling strategies and particular models for the estimation of the amount of solar radiation reaching at a particular point over the Earth. In this article, global solar radiation estimation models are taken into account. To emphasize severity of multicollinearity problem in solar radiation estimation models, some of the models developed for Turkey are revisited. It is observed that these models have been identified as accurate under certain multicollinearity structures, and when the multicollinearity is eliminated, the accuracy of these models is controversial. Thus, a reliable model that does not suffer from multicollinearity and gives precise estimates of global solar radiation for the whole region of Turkey is necessary. A new nonlinear model for the estimation of average daily horizontal solar radiation is proposed making use of the genetic programming technique. There is no multicollinearity problem in the new model, and its estimation accuracy is better than the revisited models in terms of numerous statistical performance measures. According to the proposed model, temperature, precipitation, altitude, longitude, and monthly average daily extraterrestrial horizontal solar radiation have significant effect on the average daily global horizontal solar radiation. Relative humidity and soil temperature are not included in the model due to their high correlation with precipitation and temperature, respectively. While altitude has

  20. Assessment of the solar radiation potential of the Thika and Nairobi ...

    African Journals Online (AJOL)

    This assessment seeks to provide information on the solar energy resource potential of the Thika – Nairobi area essential in the dissemination of Renewable Energy Technologies which are essentially solar photovoltaic and thermal systems. To achieve this, solar radiation data for three stations (Dagoretti Corner, Thika and ...

  1. Characterisation of a smartphone image sensor response to direct solar 305nm irradiation at high air masses.

    Science.gov (United States)

    Igoe, D P; Amar, A; Parisi, A V; Turner, J

    2017-06-01

    This research reports the first time the sensitivity, properties and response of a smartphone image sensor that has been used to characterise the photobiologically important direct UVB solar irradiances at 305nm in clear sky conditions at high air masses. Solar images taken from Autumn to Spring were analysed using a custom Python script, written to develop and apply an adaptive threshold to mitigate the effects of both noise and hot-pixel aberrations in the images. The images were taken in an unobstructed area, observing from a solar zenith angle as high as 84° (air mass=9.6) to local solar maximum (up to a solar zenith angle of 23°) to fully develop the calibration model in temperatures that varied from 2°C to 24°C. The mean ozone thickness throughout all observations was 281±18 DU (to 2 standard deviations). A Langley Plot was used to confirm that there were constant atmospheric conditions throughout the observations. The quadratic calibration model developed has a strong correlation between the red colour channel from the smartphone with the Microtops measurements of the direct sun 305nm UV, with a coefficient of determination of 0.998 and very low standard errors. Validation of the model verified the robustness of the method and the model, with an average discrepancy of only 5% between smartphone derived and Microtops observed direct solar irradiances at 305nm. The results demonstrate the effectiveness of using the smartphone image sensor as a means to measure photobiologically important solar UVB radiation. The use of ubiquitous portable technologies, such as smartphones and laptop computers to perform data collection and analysis of solar UVB observations is an example of how scientific investigations can be performed by citizen science based individuals and groups, communities and schools. Copyright © 2017 Elsevier B.V. All rights reserved.

  2. Direct conversion of nuclear energy into radiation: New direction in thermonuclear laser fusion

    International Nuclear Information System (INIS)

    Babaev, Yu.N.; Vedenov, A.A.; Filyukov, A.A.

    1995-01-01

    In investigations dealing with thermonuclear fusion, a radical new direction appeared some time ago, namely the direct conversion of nuclear and thermonuclear energy into radiation energy. This paper reviews early work on this topic in Russia and the United States and discusses some recent new directions

  3. Effects of Solar UV Radiation and Climate Change on Biogeochemical Cycling: Interactions and Feedbacks

    Science.gov (United States)

    Solar UV radiation, climate and other drivers of global change are undergoing significant changes and models forecast that these changes will continue for the remainder of this century. Here we assess the effects of solar UV radiation on biogeochemical cycles and the interactions...

  4. A critical review on the estimation of daily global solar radiation from sunshine duration

    International Nuclear Information System (INIS)

    Yorukoglu, Mehmet; Celik, Ali Naci

    2006-01-01

    Models such as the Angstroem-Prescott equation are used to estimate global solar radiation from sunshine duration. In the literature, researchers investigate either the goodness of the model itself or the goodness of the estimation of global solar radiation based on a set of statistical parameters such as R 2 , RMSE, MBE, MABE, MPE and MAPE. If the former is the objective, then the statistical analysis should naturally be based on H/H o - S/S o (the ratio of daily solar radiation to extraterrestrial daily solar radiation vs. the ratio of sunshine duration to day length). If the latter is investigated, then the statistical analysis should be based on H c - H m (calculated daily solar radiation vs. measured daily solar radiation). A literature survey undertaken in the present article showed that these two data sets are apt to be confused, drawing the statistical parameters to be used in assessment of the estimation model from the latter data set or the vice versa set. The statistical parameters are clearly derived from the basics for both of the data sets, and the inconsistencies caused by this confusion and other factors are exposed. A case study of the estimation models and global solar radiation estimation from sunshine duration is presented using five different models (linear, quadratic, cubic, logarithmic and exponential), which are the most common models used in the literature, based on 6 years long measured hourly global solar radiation data

  5. Transmission components of solar radiation in pine stands in relation to climatic and stand variables

    Science.gov (United States)

    Robert A. Muller

    1971-01-01

    In a new approach, transmission was studied by relating to stand biomass the ratio of incoming solar radiation beneath tree crowns to that within the atmosphere. Several assumptions were used to estimate analytically the various ways in which solar radiation penetrates through crowns of three pine species in northern California. Sunflecks accounted for much of the...

  6. Neural network radiative transfer solvers for the generation of high resolution solar irradiance spectra parameterized by cloud and aerosol parameters

    International Nuclear Information System (INIS)

    Taylor, M.; Kosmopoulos, P.G.; Kazadzis, S.; Keramitsoglou, I.; Kiranoudis, C.T.

    2016-01-01

    This paper reports on the development of a neural network (NN) model for instantaneous and accurate estimation of solar radiation spectra and budgets geared toward satellite cloud data using a ≈2.4 M record, high-spectral resolution look up table (LUT) generated with the radiative transfer model libRadtran. Two NN solvers, one for clear sky conditions dominated by aerosol and one for cloudy skies, were trained on a normally-distributed and multiparametric subset of the LUT that spans a very broad class of atmospheric and meteorological conditions as inputs with corresponding high resolution solar irradiance target spectra as outputs. The NN solvers were tested by feeding them with a large (10 K record) “off-grid” random subset of the LUT spanning the training data space, and then comparing simulated outputs with target values provided by the LUT. The NN solvers demonstrated a capability to interpolate accurately over the entire multiparametric space. Once trained, the NN solvers allow for high-speed estimation of solar radiation spectra with high spectral resolution (1 nm) and for a quantification of the effect of aerosol and cloud optical parameters on the solar radiation budget without the need for a massive database. The cloudy sky NN solver was applied to high spatial resolution (54 K pixel) cloud data extracted from the Spinning Enhanced Visible and Infrared Imager (SEVIRI) onboard the geostationary Meteosat Second Generation 3 (MSG3) satellite and demonstrated that coherent maps of spectrally-integrated global horizontal irradiance at this resolution can be produced on the order of 1 min. - Highlights: • Neural network radiative transfer solvers for generation of solar irradiance spectra. • Sensitivity analysis of irradiance spectra with respect to aerosol and cloud parameters. • Regional maps of total global horizontal irradiance for cloudy sky conditions. • Regional solar radiation maps produced directly from MSG3/SEVIRI satellite inputs.

  7. Nonlinear techniques for forecasting solar activity directly from its time series

    Science.gov (United States)

    Ashrafi, S.; Roszman, L.; Cooley, J.

    1993-01-01

    This paper presents numerical techniques for constructing nonlinear predictive models to forecast solar flux directly from its time series. This approach makes it possible to extract dynamical in variants of our system without reference to any underlying solar physics. We consider the dynamical evolution of solar activity in a reconstructed phase space that captures the attractor (strange), give a procedure for constructing a predictor of future solar activity, and discuss extraction of dynamical invariants such as Lyapunov exponents and attractor dimension.

  8. Methods to Estimate Solar Radiation Dosimetry in Coral Reefs Using Remote Sensed, Modeled, and in Situ Data.

    Science.gov (United States)

    Solar irradiance has been increasingly recognized as an important determinant of bleaching in coral reefs, but measurements of solar radiation exposure within coral reefs have been relatively limited. Solar irradiance and diffuse down welling attenuation coefficients (Kd, m-1) we...

  9. Performance tests and efficiency analysis of Solar Invictus 53S - A parabolic dish solar collector for direct steam generation

    Science.gov (United States)

    Jamil, Umer; Ali, Wajahat

    2016-05-01

    This paper presents the results of performance tests conducted on <