WorldWideScience

Sample records for large solar zenith

  1. Divergence of sun-rays by atmospheric refraction at large solar zenith angles

    Directory of Open Access Journals (Sweden)

    R. Uhl

    2004-01-01

    Full Text Available For the determination of photolysis rates at large zenith angles it has been demonstrated that refraction by the earth's atmosphere must be taken into account. In fact, due to the modified optical path the optical transmittance is thereby increased in most instances. Here we show that in addition the divergence of sun-rays, which is also caused by refraction but which reduces the direct solar irradiance, should not be neglected. Our calculations are based on a spherically symmetric atmosphere and include extinction by Rayleigh scattering, ozone, and background aerosol. For rays with 10km tangent altitude the divergence yields a reduction of about 10% to 40% at solar zenith angles of 91° to 96°. Moreover, we find that the divergence effect can completely cancel the relative enhancement caused by the increase of transmittance.

  2. Zenith: A Radiosonde Detector for Rapid-Response Ionizing Atmospheric Radiation Measurements During Solar Particle Events

    Science.gov (United States)

    Dyer, A. C. R.; Ryden, K. A.; Hands, A. D. P.; Dyer, C.; Burnett, C.; Gibbs, M.

    2018-03-01

    Solar energetic particle events create radiation risks for aircraft, notably single-event effects in microelectronics along with increased dose to crew and passengers. In response to this, some airlines modify their flight routes after automatic alerts are issued. At present these alerts are based on proton flux measurements from instruments onboard satellites, so it is important that contemporary atmospheric radiation measurements are made and compared. This paper presents the development of a rapid-response system built around the use of radiosondes equipped with a radiation detector, Zenith, which can be launched from a Met Office weather station after significant solar proton level alerts are issued. Zenith is a compact, battery-powered solid-state radiation monitor designed to be connected to a Vaisala RS-92 radiosonde, which transmits all data to a ground station as it ascends to an altitude of 33 km. Zenith can also be operated as a stand-alone detector when connected to a laptop, providing real-time count rates. It can also be adapted for use on unmanned aerial vehicles. Zenith has been flown on the Met Office Civil Contingency Aircraft, taken to the European Organization for Nuclear Research-EU high energy Reference Field facility for calibration and launched on a meteorological balloon at the Met Office's weather station in Camborne, Cornwall, UK. During this sounding, Zenith measured the Pfotzer-Regener maximum to be at an altitude of 18-20 km where the count rate was measured to be 1.15 c s-1 cm-2 compared to 0.02 c s-1 cm-2 at ground level.

  3. Detection of muon bundles at large zenith angles

    International Nuclear Information System (INIS)

    Aynutdinov, V.M.; Castellina, A.; Chernov, D.V.; Ezubchenko, A.A.; Fulgione, W.; Kindin, V.V.; Kokoulin, R.P.; Kompaniets, K.G.; Konovalov, A.A.; Mannocchi, G.; Petrukhin, A.A.; Rodin, Yu. N.; Saavedra, O.; Shutenko, V.V.; Trinchero, G.; Vernetto, S.; Vonsovsky, N.N.; Yanson, E.E.; Yashin, I.I.

    1999-01-01

    The large area coordinate detector (DECOR) represents a multilayer system of plastic streamer tube chamber modules surrounding the Cherenkov water calorimeter NEVOD. Experimental data collected during the test expositions of first DECOR supermodules (8 vertical planes with 8.4 m 2 working area) have been analysed, angular and spatial reconstruction accuracies have been estimated. The procedure of the selection of events corresponding to detection of parallel tracks (muon bundles originated in the atmosphere) is discussed

  4. Detection of muon bundles at large zenith angles

    Energy Technology Data Exchange (ETDEWEB)

    Aynutdinov, V.M.; Castellina, A.; Chernov, D.V.; Ezubchenko, A.A.; Fulgione, W.; Kindin, V.V.; Kokoulin, R.P.; Kompaniets, K.G.; Konovalov, A.A.; Mannocchi, G.; Petrukhin, A.A.; Rodin, Yu. N.; Saavedra, O.; Shutenko, V.V.; Trinchero, G.; Vernetto, S.; Vonsovsky, N.N.; Yanson, E.E.; Yashin, I.I

    1999-03-01

    The large area coordinate detector (DECOR) represents a multilayer system of plastic streamer tube chamber modules surrounding the Cherenkov water calorimeter NEVOD. Experimental data collected during the test expositions of first DECOR supermodules (8 vertical planes with 8.4 m{sup 2} working area) have been analysed, angular and spatial reconstruction accuracies have been estimated. The procedure of the selection of events corresponding to detection of parallel tracks (muon bundles originated in the atmosphere) is discussed.

  5. A transitioning Arctic surface energy budget: the impacts of solar zenith angle, surface albedo and cloud radiative forcing

    Energy Technology Data Exchange (ETDEWEB)

    Sedlar, Joseph; Tjernstroem, Michael; Leck, Caroline [Stockholm University, Department of Meteorology, Stockholm (Sweden); Mauritsen, Thorsten [Max-Planck-Institute for Meteorology, Hamburg (Germany); Shupe, Matthew D.; Persson, P.O.G. [University of Colorado, NOAA-ESRL-PSD, Boulder, CO (United States); Brooks, Ian M.; Birch, Cathryn E. [University of Leeds, School of Earth and Environment, Leeds (United Kingdom); Sirevaag, Anders [University of Bergen, Bjerknes Center for Climate Research, Bergen (Norway); Nicolaus, Marcel [Norwegian Polar Institute, Tromsoe (Norway); Alfred Wegener Institute for Polar and Marine Research, Bremerhaven (Germany)

    2011-10-15

    Snow surface and sea-ice energy budgets were measured near 87.5 N during the Arctic Summer Cloud Ocean Study (ASCOS), from August to early September 2008. Surface temperature indicated four distinct temperature regimes, characterized by varying cloud, thermodynamic and solar properties. An initial warm, melt-season regime was interrupted by a 3-day cold regime where temperatures dropped from near zero to -7 C. Subsequently mean energy budget residuals remained small and near zero for 1 week until once again temperatures dropped rapidly and the energy budget residuals became negative. Energy budget transitions were dominated by the net radiative fluxes, largely controlled by the cloudiness. Variable heat, moisture and cloud distributions were associated with changing air-masses. Surface cloud radiative forcing, the net radiative effect of clouds on the surface relative to clear skies, is estimated. Shortwave cloud forcing ranged between -50 W m{sup -2} and zero and varied significantly with surface albedo, solar zenith angle and cloud liquid water. Longwave cloud forcing was larger and generally ranged between 65 and 85 W m{sup -2}, except when the cloud fraction was tenuous or contained little liquid water; thus the net effect of the clouds was to warm the surface. Both cold periods occurred under tenuous, or altogether absent, low-level clouds containing little liquid water, effectively reducing the cloud greenhouse effect. Freeze-up progression was enhanced by a combination of increasing solar zenith angles and surface albedo, while inhibited by a large, positive surface cloud forcing until a new air-mass with considerably less cloudiness advected over the experiment area. (orig.)

  6. Assessment of performances of sun zenith angle and altitude parameterisations of atmospheric radiative transfer for spectral surface downwelling solar irradiance

    Science.gov (United States)

    Wald, L.; Blanc, Ph.

    2010-09-01

    Satellite-derived assessments of surface downwelling solar irradiance are more and more used by engineering companies in solar energy. Performances are judged satisfactory for the time being. Nevertheless, requests for more accuracy are increasing, in particular in the spectral definition and in the decomposition of the global radiation into direct and diffuse radiations. One approach to reach this goal is to improve both the modelling of the radiative transfer and the quality of the inputs describing the optical state. Within their joint project Heliosat-4, DLR and MINES ParisTech have adopted this approach to create advanced databases of solar irradiance succeeding to the current ones HelioClim and SolEMi. Regarding the model, we have opted for libRadtran, a well-known model of proven quality. As many similar models, running libRadtran is very time-consuming when it comes to process millions or more pixels or grid cells. This is incompatible with real-time operational process. One may adopt the abacus approach, or look-up tables, to overcome the problem. The model is run for a limited number of cases, covering the whole range of values taken by the various inputs of the model. Abaci are such constructed. For each real case, the irradiance value is computed by interpolating within the abaci. In this way, real-time can be envisioned. Nevertheless, the computation of the abaci themselves requires large computing capabilities. In addition, searching the abaci to find the values to interpolate can be time-consuming as the abaci are very large: several millions of values in total. Moreover, it raises the extrapolation problem of parameter out-of-range during the utilisation of the abaci. Parameterisation, when possible, is a means to reduce the amount of computations to be made and subsequently, the computation effort to create the abaci, the size of the abaci, the extrapolation and the searching time. It describes in analytical manner and with a few parameters the

  7. Characterizing the zenithal night sky brightness in large territories: how many samples per square kilometre are needed?

    Science.gov (United States)

    Bará, Salvador

    2018-01-01

    A recurring question arises when trying to characterize, by means of measurements or theoretical calculations, the zenithal night sky brightness throughout a large territory: how many samples per square kilometre are needed? The optimum sampling distance should allow reconstructing, with sufficient accuracy, the continuous zenithal brightness map across the whole region, whilst at the same time avoiding unnecessary and redundant oversampling. This paper attempts to provide some tentative answers to this issue, using two complementary tools: the luminance structure function and the Nyquist-Shannon spatial sampling theorem. The analysis of several regions of the world, based on the data from the New world atlas of artificial night sky brightness, suggests that, as a rule of thumb, about one measurement per square kilometre could be sufficient for determining the zenithal night sky brightness of artificial origin at any point in a region to within ±0.1 magV arcsec-2 (in the root-mean-square sense) of its true value in the Johnson-Cousins V band. The exact reconstruction of the zenithal night sky brightness maps from samples taken at the Nyquist rate seems to be considerably more demanding.

  8. Large Scale Solar Heating

    DEFF Research Database (Denmark)

    Heller, Alfred

    2001-01-01

    The main objective of the research was to evaluate large-scale solar heating connected to district heating (CSDHP), to build up a simulation tool and to demonstrate the application of the simulation tool for design studies and on a local energy planning case. The evaluation was mainly carried out...... model is designed and validated on the Marstal case. Applying the Danish Reference Year, a design tool is presented. The simulation tool is used for proposals for application of alternative designs, including high-performance solar collector types (trough solar collectors, vaccum pipe collectors......). Simulation programs are proposed as control supporting tool for daily operation and performance prediction of central solar heating plants. Finaly the CSHP technolgy is put into persepctive with respect to alternatives and a short discussion on the barries and breakthrough of the technology are given....

  9. Solar UVR instrument inter-comparison focussing on measurement interval recording setting and solar zenith angle as important factors

    CSIR Research Space (South Africa)

    Wright, GY

    2015-09-01

    Full Text Available considerations, to make meaningful deductions from the data. By comparing two solar UVR instruments, namely, a UV biometer and a Davis Vantage Pro2 UVR Detector, we look at an important factor influencing ambient solar UVR, namely SZA, and its impact... Vantage Pro2 UV detector comprises a transducer which is a semiconductor photodiode with a spectral response that matches the McKinley/Diffey Erythemal Action Spectrum. It includes a diffuser which provides good cosine response and multiple hard...

  10. Large-scale solar purchasing

    International Nuclear Information System (INIS)

    1999-01-01

    The principal objective of the project was to participate in the definition of a new IEA task concerning solar procurement (''the Task'') and to assess whether involvement in the task would be in the interest of the UK active solar heating industry. The project also aimed to assess the importance of large scale solar purchasing to UK active solar heating market development and to evaluate the level of interest in large scale solar purchasing amongst potential large scale purchasers (in particular housing associations and housing developers). A further aim of the project was to consider means of stimulating large scale active solar heating purchasing activity within the UK. (author)

  11. Sidereal semi-diurnal variation observed at high zenith angles at Mawson, 1968-1984, and the polarity of the solar main field

    International Nuclear Information System (INIS)

    Jacklyn, R.M.; Duldig, M.L.

    1985-01-01

    High zenith-angle North/South telescopes viewing equatorially and at midlatitudes through 40 MWE of atmosphere have been operating at Mawson since early 1968. It is evident that a sidereal semi-diurnal component of galactic origin has been observed, over and above a possible spurious component proposed by Nagashima, arising from a bi-directional component of the solar anisotropy. Although a very pronounced reduction in the semi-diurnal galactic response followed the reversal of polarity of the solar main field during 1969 to 1971, so far the observations indicate that there has been no recurrence of a larger galactic response following the reversal of polarity around 1981. The possible role of the latitudional extent lambda omicron of the wavy neutral sheet is discussed

  12. Very short-term reactive forecasting of the solar ultraviolet index using an extreme learning machine integrated with the solar zenith angle.

    Science.gov (United States)

    Deo, Ravinesh C; Downs, Nathan; Parisi, Alfio V; Adamowski, Jan F; Quilty, John M

    2017-05-01

    Exposure to erythemally-effective solar ultraviolet radiation (UVR) that contributes to malignant keratinocyte cancers and associated health-risk is best mitigated through innovative decision-support systems, with global solar UV index (UVI) forecast necessary to inform real-time sun-protection behaviour recommendations. It follows that the UVI forecasting models are useful tools for such decision-making. In this study, a model for computationally-efficient data-driven forecasting of diffuse and global very short-term reactive (VSTR) (10-min lead-time) UVI, enhanced by drawing on the solar zenith angle (θ s ) data, was developed using an extreme learning machine (ELM) algorithm. An ELM algorithm typically serves to address complex and ill-defined forecasting problems. UV spectroradiometer situated in Toowoomba, Australia measured daily cycles (0500-1700h) of UVI over the austral summer period. After trialling activations functions based on sine, hard limit, logarithmic and tangent sigmoid and triangular and radial basis networks for best results, an optimal ELM architecture utilising logarithmic sigmoid equation in hidden layer, with lagged combinations of θ s as the predictor data was developed. ELM's performance was evaluated using statistical metrics: correlation coefficient (r), Willmott's Index (WI), Nash-Sutcliffe efficiency coefficient (E NS ), root mean square error (RMSE), and mean absolute error (MAE) between observed and forecasted UVI. Using these metrics, the ELM model's performance was compared to that of existing methods: multivariate adaptive regression spline (MARS), M5 Model Tree, and a semi-empirical (Pro6UV) clear sky model. Based on RMSE and MAE values, the ELM model (0.255, 0.346, respectively) outperformed the MARS (0.310, 0.438) and M5 Model Tree (0.346, 0.466) models. Concurring with these metrics, the Willmott's Index for the ELM, MARS and M5 Model Tree models were 0.966, 0.942 and 0.934, respectively. About 57% of the ELM model

  13. Large-scale solar heat

    Energy Technology Data Exchange (ETDEWEB)

    Tolonen, J.; Konttinen, P.; Lund, P. [Helsinki Univ. of Technology, Otaniemi (Finland). Dept. of Engineering Physics and Mathematics

    1998-12-31

    In this project a large domestic solar heating system was built and a solar district heating system was modelled and simulated. Objectives were to improve the performance and reduce costs of a large-scale solar heating system. As a result of the project the benefit/cost ratio can be increased by 40 % through dimensioning and optimising the system at the designing stage. (orig.)

  14. Introducing Zenith project

    International Nuclear Information System (INIS)

    Dupejova, E.

    2008-01-01

    Zenith ia a international program of continuous improvement, aimed at reaching high work performance in all ENEL activities and in all countries where ENEL is present Zenith covers various projects aimed at cost reduction, processes simplification and performance improvement that have been already initiated in the past (DTC, TTC, QUASAR...) The program includes 5 pillars to reach perfection: - reaching for operational proficiency by underlining the leading role of ENEL and continuous searching possibilities how to improve processes and activities; - to learn methods of continuous the others; - to learn and apply the methods of improvement; - continuously apply the methods of improvement; - continuously monitor and publish the results and implementation of ZENITH standard. (author)

  15. Large-scale solar heating

    Energy Technology Data Exchange (ETDEWEB)

    Tolonen, J.; Konttinen, P.; Lund, P. [Helsinki Univ. of Technology, Otaniemi (Finland). Advanced Energy Systems

    1998-10-01

    Solar heating market is growing in many European countries and annually installed collector area has exceeded one million square meters. There are dozens of collector manufacturers and hundreds of firms making solar heating installations in Europe. One tendency in solar heating is towards larger systems. These can be roof integrated, consisting of some tens or hundreds of square meters of collectors, or they can be larger centralized solar district heating plants consisting of a few thousand square meters of collectors. The increase of size can reduce the specific investments of solar heating systems, because e.g. the costs of some components (controllers, pumps, and pipes), planning and installation can be smaller in larger systems. The solar heat output can also be higher in large systems, because more advanced technique is economically viable

  16. Plutonium cores of zenith

    Energy Technology Data Exchange (ETDEWEB)

    Barclay, F R; Cameron, I R; Drageset, A; Freemantle, R G; Wilson, D J

    1965-03-15

    The report describes a series of experiments carried out with plutonium fuel in the heated zero power reactor ZENITH, with the aim of testing current theoretical methods, with particular reference to excess reactivity, temperature coefficients, differential spectrum and reaction rate distributions. Two cores of widely different fissile/moderator atom ratios were loaded in order to test the theory under significantly varied spectrum conditions.

  17. Measurement-based J(NO2) sensitivity in a cloudless atmosphere under low aerosol loading and high solar zenith angle conditions

    International Nuclear Information System (INIS)

    Frueh, B.; Trautmann, T.

    2000-01-01

    The comparison between measured and simulated photodissociation frequencies of NO 2 , J(NO 2 ), in a cloudless atmosphere in a recent paper by Frueh et al., 2000 (Journal of Geophysical Research 105, 9843-9857) revealed an overestimation of J(NO 2 ) near ground level by model calculations compared with measurements and an underestimation in the upper part of the aerosol layer. A possible reason for the disagreement is the changing sun position during the vertical ascent. To resolve this problem we carried out a sensitivity study varying the solar zenith angle of 74 o by 1.4 o (which corresponds to the change of sun position during the vertical flight patterns). This results in a considerable deviation of J(NO 2 ) of about 10%. Further sensitivity studies on J(NO 2 ) have been done. These include realistic variations in ground albedo, humidity and aerosol properties. A variation in ground albedo from the measured value of A G = 0.023 (292-420 nm wavelength) to A G = 0 and A G = 0.05, respectively, resulted in an average J(NO 2 ) reduction and enhancement of only 2% near ground level with a slight decrease with increasing altitude. Furthermore, we compared simulations based on different relative humidity profiles with results from a dry atmosphere. Compared to the dry case the deviations of J(NO 2 ) were considerable (5-16%) although the measured aerosol concentration was very low. Moreover, we doubled the aerosol particle concentration. The maximum J(NO 2 ) deviations were in the same order of magnitude as for the relative humidity (5-16%). These changes are in the range of measurement uncertainty of J(NO 2 ) (author)

  18. Cosmic ray zenith angle distribution at low geomagnetic latitude

    Energy Technology Data Exchange (ETDEWEB)

    Aragon, G [Instituto de Astronomia y Fisica del Espacio, Buenos Aires, Argentina; Gagliardini, A; Ghielmetti, H S

    1977-12-01

    The intensity of secondary charged cosmic rays at different zenith angles was measured by narrow angle Geiger-Mueller telescopes up to an atmospheric depth of 2 g cm/sup -2/. The angular distribution observed at high altitudes is nearly flat at small angles around the vertical and suggests that the particle intensity peaks at large zenith angles, close to the horizon.

  19. Large-scale Motion of Solar Filaments

    Indian Academy of Sciences (India)

    tribpo

    Large-scale Motion of Solar Filaments. Pavel Ambrož, Astronomical Institute of the Acad. Sci. of the Czech Republic, CZ-25165. Ondrejov, The Czech Republic. e-mail: pambroz@asu.cas.cz. Alfred Schroll, Kanzelhöehe Solar Observatory of the University of Graz, A-9521 Treffen,. Austria. e-mail: schroll@solobskh.ac.at.

  20. Emerging large-scale solar heating applications

    International Nuclear Information System (INIS)

    Wong, W.P.; McClung, J.L.

    2009-01-01

    Currently the market for solar heating applications in Canada is dominated by outdoor swimming pool heating, make-up air pre-heating and domestic water heating in homes, commercial and institutional buildings. All of these involve relatively small systems, except for a few air pre-heating systems on very large buildings. Together these applications make up well over 90% of the solar thermal collectors installed in Canada during 2007. These three applications, along with the recent re-emergence of large-scale concentrated solar thermal for generating electricity, also dominate the world markets. This paper examines some emerging markets for large scale solar heating applications, with a focus on the Canadian climate and market. (author)

  1. Emerging large-scale solar heating applications

    Energy Technology Data Exchange (ETDEWEB)

    Wong, W.P.; McClung, J.L. [Science Applications International Corporation (SAIC Canada), Ottawa, Ontario (Canada)

    2009-07-01

    Currently the market for solar heating applications in Canada is dominated by outdoor swimming pool heating, make-up air pre-heating and domestic water heating in homes, commercial and institutional buildings. All of these involve relatively small systems, except for a few air pre-heating systems on very large buildings. Together these applications make up well over 90% of the solar thermal collectors installed in Canada during 2007. These three applications, along with the recent re-emergence of large-scale concentrated solar thermal for generating electricity, also dominate the world markets. This paper examines some emerging markets for large scale solar heating applications, with a focus on the Canadian climate and market. (author)

  2. Chinese large solar telescopes site survey

    Science.gov (United States)

    Liu, Yu

    2017-04-01

    In order to observe the solar surface with unprecedentedly higher resolution, Chinse solar physics society decided to launch their solar site survey project in 2010 as the first step to look for the best candidate sites for the Chinese next-generation large-aperture solar telescopes, i.e., the 5-8 meter Chinese Giant Solar Telescope, and the 1 meter level coronagraph. We have built two long-term monitoring sites in Daocheng, with altitudes of around 4800 meters above the sea level located in the large Shangri-La mountain area, and we have collected systematic site data since 2014. Clear evidence, including the key parameters of seeing factor, sky brightness and water vapor content, has indicated that the large Shangri-La area owns the potential conditions of excellent seeing level and sufficient amount of clear-sky hours suitable for developing large solar telescopes. We will review the site survey progress and present the preliminary statistical results in this talk.

  3. Little Eyes on Large Solar Motions

    Science.gov (United States)

    Kohler, Susanna

    2017-10-01

    Images taken during the solar eclipse in 2012. The central color composite of the eclipsed solar surface was captured by SDO, the white-light view of the solar corona around it was taken by the authors, and the background, wide-field black-and-white view is from LASCO. The white arrows mark the atypical structure. [Alzate et al. 2017]It seems like science is increasingly being done with advanced detectors on enormous ground- and space-based telescopes. One might wonder: is there anything left to learn from observations made with digital cameras mounted on 10-cm telescopes?The answer is yes plenty! Illustrating this point, a new study using such equipment recently reports on the structure and dynamics of the Suns corona during two solar eclipses.A Full View of the CoronaThe solar corona is the upper part of the Suns atmosphere, extending millions of kilometers into space. This plasma is dynamic, with changing structures that arise in response to activity on the Suns surface such as enormous ejections of energy known as coronal mass ejections (CMEs). Studying the corona is therefore important for understanding what drives its structure and how energy is released from the Sun.Though there exist a number of space-based telescopes that observe the Suns corona, they often have limited fields of view. The Solar Dynamics Observatory AIA, for instance, has spectacular resolution but only images out to 1/3 of a solar radius above the Suns limb. The space-based coronagraph LASCO C2, on the other hand, provides a broad view of the outer regions of the corona, but it only images down to 2.2 solar radii above the Suns limb. Piecing together observations from these telescopes therefore leaves a gap that prevents a full picture of the large-scale corona and how it connects to activity at the solar surface.Same as the previous figure, but for the eclipse in 2013. [Alzate et al. 2017]To provide this broad, continuous picture, a team of scientists used digital cameras mounted on 10

  4. Large Bandgap Semiconductors for Solar Water Splitting

    DEFF Research Database (Denmark)

    Malizia, Mauro

    Photoelectrochemical water splitting represents an eco-friendly technology that could enable the production of hydrogen using water as reactant and solar energy as primary energy source. The exploitation of solar energy for the production of hydrogen would help modern society to reduce the reliance...... on fossil fuels as primary feedstock for hydrogen production and diminish the emission of greenhouse gases in the atmosphere, weakening the global warming phenomenon.The dissertation reports the development of GaP (gallium phosphide) photocathodes as a large bandgap semiconductor for photoelectrochemical...... water splitting devices having tandem design. The increase of the photovoltage produced by GaP under illumination was the main goal of this work. GaP has a bandgap of 2.25 eV and could in theory produce a photovoltage of approximately 1.7 V. Instead, the photovoltage produced by the semiconductor...

  5. Large solar energy systems within IEA task 14

    NARCIS (Netherlands)

    Geus, A.C. de; Isakson, P.; Bokhoven, T.P.; Vanoli, K.; Tepe, R.

    1996-01-01

    Within IEA Task 14 (Advanced Solar Systems) a working group was established dealing with large advanced solar energy systems (the Large Systems Working group). The goal of this working group was to generate a common base of experiences for the design and construction of advanced large solar systems.

  6. Zenith 1 truss transfer ceremony

    Science.gov (United States)

    2000-01-01

    The Zenith-1 (Z-1) Truss is officially presented to NASA by The Boeing Co. on the Space Station Processing Facility floor on July 31. STS-92 Commander Col. Brian Duffy, comments on the presentation. Pictured are The Boeing Co. processing team and STS-92 astronauts. The Z-1 Truss is the cornerstone truss of the International Space Station and is scheduled to fly in Space Shuttle Discovery's payload pay on STS-92 targeted for launch Oct. 5, 2000. The Z-1 is considered a cornerstone truss because it carries critical components of the Station's attitude, communications, thermal and power control systems as well as four control moment gyros, high and low gain antenna systems, and two plasma contactor units used to disperse electrical charge build- ups. The Z-1 truss and a Pressurized Mating Adapter (PMA-3), also flying to the Station on the same mission, will be the first major U.S. elements flown to the ISS aboard the Shuttle since the launch of the Unity element in December 1998.

  7. Proposed National Large Solar Telescope Jagdev Singh

    Indian Academy of Sciences (India)

    proposed to design, fabricate and install a 2-meter class solar telescope at a suitable site in India to ... which can facilitate simultaneous measurements of the solar atmospheric parameters and of the vector ... Intensity variation of. 1% or less.

  8. Thermal power generation projects ``Large Scale Solar Heating``; EU-Thermie-Projekte ``Large Scale Solar Heating``

    Energy Technology Data Exchange (ETDEWEB)

    Kuebler, R.; Fisch, M.N. [Steinbeis-Transferzentrum Energie-, Gebaeude- und Solartechnik, Stuttgart (Germany)

    1998-12-31

    The aim of this project is the preparation of the ``Large-Scale Solar Heating`` programme for an Europe-wide development of subject technology. The following demonstration programme was judged well by the experts but was not immediately (1996) accepted for financial subsidies. In November 1997 the EU-commission provided 1,5 million ECU which allowed the realisation of an updated project proposal. By mid 1997 a small project was approved, that had been requested under the lead of Chalmes Industriteteknik (CIT) in Sweden and is mainly carried out for the transfer of technology. (orig.) [Deutsch] Ziel dieses Vorhabens ist die Vorbereitung eines Schwerpunktprogramms `Large Scale Solar Heating`, mit dem die Technologie europaweit weiterentwickelt werden sollte. Das daraus entwickelte Demonstrationsprogramm wurde von den Gutachtern positiv bewertet, konnte jedoch nicht auf Anhieb (1996) in die Foerderung aufgenommen werden. Im November 1997 wurden von der EU-Kommission dann kurzfristig noch 1,5 Mio ECU an Foerderung bewilligt, mit denen ein aktualisierter Projektvorschlag realisiert werden kann. Bereits Mitte 1997 wurde ein kleineres Vorhaben bewilligt, das unter Federfuehrung von Chalmers Industriteknik (CIT) in Schweden beantragt worden war und das vor allem dem Technologietransfer dient. (orig.)

  9. Month-hour distributions of zenith luminance and diffuse illuminance in Madrid

    International Nuclear Information System (INIS)

    Soler, Alfonso; Gopinathan, Kannam K.; Robledo, Luis; Ruiz, Enrique

    2004-01-01

    Month-hour equal mean zenith luminance contours are obtained from one year of data of zenith luminance measurements for cloudless, overcast and partly cloudy skies and also when the combined data for all sky types are considered. For many hours in different months, the overcast sky luminance values are roughly about three times the cloudless sky luminance values and one and a half times the partly cloudy sky values. The dependence of month-hour equal mean zenith luminance contours on the ratio of global to extraterrestrial illuminance on a horizontal surface is also given. From equal mean zenith luminance contours, the approximate values of the mean zenith luminance for different sky conditions and different hours and months of the year can be easily obtained. Month-hour equal mean diffuse illuminance contours are obtained from diffuse illuminance measurements performed during the period 1992-1998. The dependence on solar altitude of the monthly average hourly values of diffuse illuminance is given and compared to the corresponding one obtained from data for Bet Dagan (Israel)

  10. European research school on large scale solar thermal – SHINE

    DEFF Research Database (Denmark)

    Bales, Chris; Forteza, Pau Joan Cortés; Furbo, Simon

    2014-01-01

    The Solar Heat Integration NEtwork (SHINE) is a European research school in which 13 PhD students in solar thermal technologies are funded by the EU Marie-Curie program. It has five PhD course modules as well as workshops and seminars dedicated to PhD students both within the project as well...... as outside of it. The SHINE research activities focus on large solar heating systems and new applications: on district heating, industrial processes and new storage systems. The scope of this paper is on systems for district heating for which there are five PhD students, three at universities and two...

  11. A report on core 5 of ZENITH

    International Nuclear Information System (INIS)

    Barclay, F.R.; Cameron, I.R.; Freemantle, R.G.; Reed, D.L.; Wilson, D.J.

    1964-06-01

    The determination of the excess reactivity, control rod worths, flux fine structure, temperature coefficients, differential spectra and reaction rates of various nuclides for the fifth loading of the heated zero energy reactor ZENITH is described. The core contained 32.6 Kgm of U235, giving a carbon/U235 atomic ratio of 1072, and formed the least moderated of the range studied. Comparisons of the experimental results with calculations using multigroup diffusion codes are presented. (author)

  12. Development and production of Zenith fissile elements

    Energy Technology Data Exchange (ETDEWEB)

    George, D; Wheatley, C C.H.; Lloyd, H

    1959-06-15

    The development of a new glass-bonded alumina-uranium oxide composition forming the fissile component of the Zenith fuel elements is described, together with the production of the initial charge containing 15 Kg. of U{sub 235]; the composition is capable of retaining fission product gases at high temperatures. The description includes criticality considerations, details of manufacture, and production statistics of the 11,000 discs produced.

  13. Geospatial Optimization of Siting Large-Scale Solar Projects

    Energy Technology Data Exchange (ETDEWEB)

    Macknick, Jordan [National Renewable Energy Lab. (NREL), Golden, CO (United States); Quinby, Ted [National Renewable Energy Lab. (NREL), Golden, CO (United States); Caulfield, Emmet [Stanford Univ., CA (United States); Gerritsen, Margot [Stanford Univ., CA (United States); Diffendorfer, Jay [U.S. Geological Survey, Boulder, CO (United States); Haines, Seth [U.S. Geological Survey, Boulder, CO (United States)

    2014-03-01

    Recent policy and economic conditions have encouraged a renewed interest in developing large-scale solar projects in the U.S. Southwest. However, siting large-scale solar projects is complex. In addition to the quality of the solar resource, solar developers must take into consideration many environmental, social, and economic factors when evaluating a potential site. This report describes a proof-of-concept, Web-based Geographical Information Systems (GIS) tool that evaluates multiple user-defined criteria in an optimization algorithm to inform discussions and decisions regarding the locations of utility-scale solar projects. Existing siting recommendations for large-scale solar projects from governmental and non-governmental organizations are not consistent with each other, are often not transparent in methods, and do not take into consideration the differing priorities of stakeholders. The siting assistance GIS tool we have developed improves upon the existing siting guidelines by being user-driven, transparent, interactive, capable of incorporating multiple criteria, and flexible. This work provides the foundation for a dynamic siting assistance tool that can greatly facilitate siting decisions among multiple stakeholders.

  14. On the measurements of large scale solar velocity fields

    International Nuclear Information System (INIS)

    Andersen, B.N.

    1985-01-01

    A general mathematical formulation for the correction of the scattered light influence on solar Doppler shift measurements has been developed. This method has been applied to the straylight correction of measurements of solar rotation, limb effect, large scale flows and oscillations. It is shown that neglecting the straylight errors may cause spurious large scale velocity fields, oscillations and erronous values for the solar rotation and limb effect. The influence of active regions on full disc velocity measurements has been studied. It is shown that a 13 day periodicity in the global velocity signal will be introduced by the passage of sunspots over the solar disc. With different types of low resolution apertures, other periodicities may be introduced. Accurate measurements of the center-to-limb velocity shift are presented for a set of magnetic insensitive lines well suited for solar velocity measurements. The absolute wavelenght shifts are briefly discussed. The stronger lines have a ''supergravitational'' shift of 300-400 m/s at the solar limb. The results may be explained by the presence of a 20-25 m/s poleward meridional flow and a latitudinal dependence of the granular parameters. Using a simple model it is shown that the main properites of the observations are explained by a 5% increase in the granular size with latitude. Data presented indicate that the resonance line K I, 769.9 nm has a small but significant limb effect of 125 m/s from center to limb

  15. Temporal Variation of Large Scale Flows in the Solar Interior ...

    Indian Academy of Sciences (India)

    tribpo

    Temporal Variation of Large Scale Flows in the Solar Interior. 355. Figure 2. Zonal and meridional components of the time-dependent residual velocity at a few selected depths as marked above each panel, are plotted as contours of constant velocity in the longitude-latitude plane. The left panels show the zonal component, ...

  16. Large scale solar district heating. Evaluation, modelling and designing - Appendices

    Energy Technology Data Exchange (ETDEWEB)

    Heller, A.

    2000-07-01

    The appendices present the following: A) Cad-drawing of the Marstal CSHP design. B) Key values - large-scale solar heating in Denmark. C) Monitoring - a system description. D) WMO-classification of pyranometers (solarimeters). E) The computer simulation model in TRNSYS. F) Selected papers from the author. (EHS)

  17. Large area, low cost solar cell development and production readiness

    Science.gov (United States)

    Michaels, D.

    1982-01-01

    A process sequence for a large area ( or = 25 sq. cm) silicon solar cell was investigated. Generic cell choice was guided by the expected electron fluence, by the packing factors of various cell envelope designs onto each panel to provide needed voltage as well as current, by the weight constraints on the system, and by the cost goals of the contract.

  18. Large scale solar district heating. Evaluation, modelling and designing

    Energy Technology Data Exchange (ETDEWEB)

    Heller, A.

    2000-07-01

    The main objective of the research was to evaluate large-scale solar heating connected to district heating (CSDHP), to build up a simulation tool and to demonstrate the application of the tool for design studies and on a local energy planning case. The evaluation of the central solar heating technology is based on measurements on the case plant in Marstal, Denmark, and on published and unpublished data for other, mainly Danish, CSDHP plants. Evaluations on the thermal, economical and environmental performances are reported, based on the experiences from the last decade. The measurements from the Marstal case are analysed, experiences extracted and minor improvements to the plant design proposed. For the detailed designing and energy planning of CSDHPs, a computer simulation model is developed and validated on the measurements from the Marstal case. The final model is then generalised to a 'generic' model for CSDHPs in general. The meteorological reference data, Danish Reference Year, is applied to find the mean performance for the plant designs. To find the expectable variety of the thermal performance of such plants, a method is proposed where data from a year with poor solar irradiation and a year with strong solar irradiation are applied. Equipped with a simulation tool design studies are carried out spreading from parameter analysis over energy planning for a new settlement to a proposal for the combination of plane solar collectors with high performance solar collectors, exemplified by a trough solar collector. The methodology of utilising computer simulation proved to be a cheap and relevant tool in the design of future solar heating plants. The thesis also exposed the demand for developing computer models for the more advanced solar collector designs and especially for the control operation of CSHPs. In the final chapter the CSHP technology is put into perspective with respect to other possible technologies to find the relevance of the application

  19. The COronal Solar Magnetism Observatory (COSMO) Large Aperture Coronagraph

    Science.gov (United States)

    Tomczyk, Steve; Gallagher, Dennis; Wu, Zhen; Zhang, Haiying; Nelson, Pete; Burkepile, Joan; Kolinksi, Don; Sutherland, Lee

    2013-04-01

    The COSMO is a facility dedicated to observing coronal and chromospheric magnetic fields. It will be located on a mountaintop in the Hawaiian Islands and will replace the current Mauna Loa Solar Observatory (MLSO). COSMO will provide unique observations of the global coronal magnetic fields and its environment to enhance the value of data collected by other observatories on the ground (e.g. SOLIS, BBO NST, Gregor, ATST, EST, Chinese Giant Solar Telescope, NLST, FASR) and in space (e.g. SDO, Hinode, SOHO, GOES, STEREO, Solar-C, Solar Probe+, Solar Orbiter). COSMO will employ a fleet of instruments to cover many aspects of measuring magnetic fields in the solar atmosphere. The dynamics and energy flow in the corona are dominated by magnetic fields. To understand the formation of CMEs, their relation to other forms of solar activity, and their progression out into the solar wind requires measurements of coronal magnetic fields. The large aperture coronagraph, the Chromospheric and Prominence Magnetometer and the K-Coronagraph form the COSMO instrument suite to measure magnetic fields and the polarization brightness of the low corona used to infer electron density. The large aperture coronagraph will employ a 1.5 meter fuse silica singlet lens, birefringent filters, and a spectropolarimeter to cover fields of view of up to 1 degree. It will observe the corona over a wide range of emission lines from 530.3 nm through 1083.0 nm allowing for magnetic field measurements over a wide range of coronal temperatures (e.g. FeXIV at 530.3 nm, Fe X at 637.4 nm, Fe XIII at 1074.7 and 1079.8 nm. These lines are faint and require the very large aperture. NCAR and NSF have provided funding to bring the large aperture coronagraph to a preliminary design review state by the end of 2013. As with all data from Mauna Loa, the data products from COSMO will be available to the community via the Mauna Loa website: http://mlso.hao.ucar.edu

  20. Heat-rejection design for large concentrating solar arrays

    Science.gov (United States)

    French, E. P.

    1980-01-01

    This paper considers the effect of heat rejection devices (radiators) on the performance and cost of large concentrating solar arrays for space application. Overall array characteristics are derived from the weight, cost, and performance of four major components; namely primary structure, optics/secondary structure, radiator, and solar panel. An ideal concentrator analysis is used to establish general cost and performance trends independent of specific array design. Both passive and heat-pipe radiation are evaluated, with an incremental cost-of-power approach used in the evaluation. Passive radiators are found to be more cost effective with silicon than with gallium arsenide (GaAs) arrays. Representative concentrating arrays have been evaluated for both near-term and advanced solar cell technology. Minimum cost of power is achieved at geometric concentration ratios in the range 2 to 6.

  1. Solar wind fluctuations at large scale: A comparison between low and high solar activity conditions

    International Nuclear Information System (INIS)

    Bavassano, B.; Bruno, R.

    1991-01-01

    The influence of the Sun's activity cycle on the solar wind fluctuations at time scales from 1 hour to 3 days in the inner heliosphere (0.3 to 1 AU) is investigated. Hourly averages of plasma and magnetic field data by Helios spacecraft are used. Since fluctuations behave quite differently with changing scale, the analysis is performed separately for two different ranges in time scale. Between 1 and 6 hours Alfvenic fluctuations and pressure-balanced structures are extensively observed. At low solar activity and close to 0.3 AU, Alfvenic fluctuations are more frequent than pressure-balanced structures. This predominance, however, weakens for rising solar activity and radial distance, to the point that a role exchange, in terms of occurrence rate, is found at the maximum of the cycle close to 1 AU. On the other hand, in all cases Alfvenic fluctuations have a larger amplitude than pressure-balanced structures. On the whole, the Alfvenic contribution to the solar wind energy spectrum comes out to be dominant at all solar activity conditions. At scales from 0.5 to 3 days the most important feature is the growth, as the solar wind expansion develops, of strong positive correlations between magnetic and thermal pressures. These structures are progressively built up by the interaction between different wind flows. This effect is more pronounced at low than at high activity. Our findings support the conclusion that the solar cycle evolution of the large-scale velocity pattern is the factor governing the observed variations

  2. 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)

  3. Estimates of radiance reflected towards the zenith at the surface of the sea

    Directory of Open Access Journals (Sweden)

    E. Aas

    2010-10-01

    Full Text Available Remote sensing of water colour by ship-mounted sensors represents an important tool for the validation of satellite products and the monitoring of water quality. The recorded radiance from the sea has to be corrected for the surface-reflected radiance from sun and sky in order to obtain the water-leaving radiance. Here the simple case of radiance reflected towards the zenith is studied. A set of observed sky radiance and solar irradiance data from Oslo has been used together with a Gaussian slope distribution for the sea surface in order to estimate the reflected radiance. The spectral range studied is 405–650 nm, the solar zenith angles are in the range 37°–76°, and the wind speeds are up to 10 m s−1. The analysis of the results show that the reflected radiance has to be separated into three contributions: sky radiance and sun rays reflected at the foam-free surface and irradiance reflected by whitecaps and foam. It is then demonstrated that by using four input values, namely the downward irradiance, the sky radiance from the zenith, the solar zenith angle and the wind speed, it is possible to obtain by simple expressions estimates of the reflected radiance that only differ from the former calculated values by relative errors of less than 5%. The analysis also indicates that for the spectral range studied neither the water-leaving radiance nor the surface-reflected radiance can be disregarded relative to the other one in the Case 2 waters of the Oslofjord-Skagerrak area. The results form a first step towards the study of reflected radiance in viewing angles differing from the nadir direction.

  4. Colocation opportunities for large solar infrastructures and agriculture in drylands

    International Nuclear Information System (INIS)

    Ravi, Sujith; Macknick, Jordan; Lobell, David; Field, Christopher; Ganesan, Karthik; Jain, Rishabh; Elchinger, Michael; Stoltenberg, Blaise

    2016-01-01

    Highlights: • We explored the potential to colocate solar installations and agriculture. • Water use at solar installations are similar to amounts required for desert plants. • Co-located systems are economically viable in some areas. • Colocation can maximize land and water use efficiency in drylands. - Abstract: Solar energy installations in arid and semi-arid regions are rapidly increasing due to technological advances and policy support. Although solar energy provides several benefits such as reduction of greenhouse gases, reclamation of degraded land, and improved quality of life in developing countries, the deployment of large-scale renewable energy infrastructure may negatively impact land and water resources. Meeting the ever-expanding energy demand with limited land and water resources in the context of increasing demand for alternative uses such as agricultural and domestic consumption is a major challenge. The goal of this study was to explore opportunities to colocate solar infrastructures and agricultural crops to maximize the efficiency of land and water use. We investigated the energy inputs/outputs, water use, greenhouse gas emissions, and economics of solar installations in northwestern India in comparison to aloe vera cultivation, another widely promoted and economically important land use in these systems. The life cycle analyses show that the colocated systems are economically viable in some rural areas and may provide opportunities for rural electrification and stimulate economic growth. The water inputs for cleaning solar panels are similar to amounts required for annual aloe productivity, suggesting the possibility of integrating the two systems to maximize land and water use efficiency. A life cycle analysis of a hypothetical colocation indicated higher returns per m"3 of water used than either system alone. The northwestern region of India has experienced high population growth in the past decade, creating additional demand for land

  5. Solar wind fluctuations at large scale - A comparison between low and high solar activity conditions

    Science.gov (United States)

    Bavassano, B.; Bruno, R.

    1991-02-01

    The influence of the sun's activity cycle on the solar wind fluctuations at time scales from 1 hour to 3 days in the inner heliosphere (0.3 to 1 AU) is investigated. Hourly averages of plasma and magnetic field data by Helios spacecraft are used. Since fluctuations behave quite differently with changing scale, the analysis is performed separately for two different ranges in time scale. Between 1 and 6 hours Alfvenic fluctuations and pressure-balanced structures are extensively observed. At low solar activity and close to 0.3 AU Alfvenic fluctuations are more frequent than pressure-balanced structures. This predominance, however, weakens for rising solar activity and radial distance, to the point that a role-exchange, in terms of occurrence rate, is found at the maximum of the cycle close to 1 AU. On the other hand, in all cases Alfvenic fluctuations have a larger amplitude than pressure-balanced structures. The Alfvenic contribution to the solar wind energy spectrum comes out to be dominant at all solar activity conditions. These findings support the conclusion that the solar cycle evolution of the large-scale velocity pattern is the factor governing the observed variations.

  6. High-Efficiency, Multijunction Solar Cells for Large-Scale Solar Electricity Generation

    Science.gov (United States)

    Kurtz, Sarah

    2006-03-01

    A solar cell with an infinite number of materials (matched to the solar spectrum) has a theoretical efficiency limit of 68%. If sunlight is concentrated, this limit increases to about 87%. These theoretical limits are calculated using basic physics and are independent of the details of the materials. In practice, the challenge of achieving high efficiency depends on identifying materials that can effectively use the solar spectrum. Impressive progress has been made with the current efficiency record being 39%. Today's solar market is also showing impressive progress, but is still hindered by high prices. One strategy for reducing cost is to use lenses or mirrors to focus the light on small solar cells. In this case, the system cost is dominated by the cost of the relatively inexpensive optics. The value of the optics increases with the efficiency of the solar cell. Thus, a concentrator system made with 35%- 40%-efficient solar cells is expected to deliver 50% more power at a similar cost when compare with a system using 25%-efficient cells. Today's markets are showing an opportunity for large concentrator systems that didn't exist 5-10 years ago. Efficiencies may soon pass 40% and ultimately may reach 50%, providing a pathway to improved performance and decreased cost. Many companies are currently investigating this technology for large-scale electricity generation. The presentation will cover the basic physics and more practical considerations to achieving high efficiency as well as describing the current status of the concentrator industry. This work has been authored by an employee of the Midwest Research Institute under Contract No. DE- AC36-99GO10337 with the U.S. Department of Energy. The United States Government retains and the publisher, by accepting the article for publication, acknowledges that the United States Government retains a non-exclusive, paid-up, irrevocable, worldwide license to publish or reproduce the published form of this work, or allow

  7. Large, real time detectors for solar neutrinos and magnetic monopoles

    International Nuclear Information System (INIS)

    Gonzalez-Mestres, L.

    1990-01-01

    We discuss the present status of superheated superconducting granules (SSG) development for the real time detection of magnetic monopoles of any speed and of low energy solar neutrinos down to the pp region (indium project). Basic properties of SSG and progress made in the recent years are briefly reviewed. Possible ways for further improvement are discussed. The performances reached in ultrasonic grain production at ∼ 100 μm size, as well as in conventional read-out electronics, look particularly promising for a large scale monopole experiment. Alternative approaches are briefly dealt with: induction loops for magnetic monopoles; scintillators, semiconductors or superconducting tunnel junctions for a solar neutrino detector based on an indium target

  8. Overview of the MISSE 7 Polymers and Zenith Polymers Experiments After 1.5 Years of Space Exposure

    Science.gov (United States)

    Yi, Grace T.; de Groh, Kim K.; Banks, Bruce A.; Haloua, Athena; Imka, Emily C.; Mitchell, Gianna G.

    2013-01-01

    As part of the Materials International Space Station Experiment 7 (MISSE 7), two experiments called the Polymers Experiment and the Zenith Polymers Experiment were flown on the exterior of the International Space Station (ISS) and exposed to the low Earth orbit (LEO) space environment for 1.5 years. The Polymers Experiment contained 47 samples, which were flown in a ram or wake flight orientation. The objectives of the Polymers Experiment were to determine the LEO atomic oxygen erosion yield (Ey, volume loss per incident oxygen atoms, given in cu cm/atom) of the polymers, and to determine if atomic oxygen erosion of high and low ash containing polymers is dependent on fluence. The Zenith Polymers Experiment was flown in a zenith flight orientation. The primary objective of the Zenith Polymers Experiment was to determine the effect of solar exposure on the erosion of fluoropolymers. Kapton H (DuPont, Wilmington, DE) was flown in each experiment for atomic oxygen fluence determination. This paper provides an introduction to both the MISSE 7 Polymers Experiment and the MISSE 7 Zenith Polymers Experiment, and provides initial erosion yield results.

  9. THE 'TWIN-CME' SCENARIO AND LARGE SOLAR ENERGETIC PARTICLE EVENTS IN SOLAR CYCLE 23

    International Nuclear Information System (INIS)

    Ding, Liuguan; Jiang, Yong; Zhao, Lulu; Li, Gang

    2013-01-01

    Energetic particles in large solar energetic particle (SEP) events are a major concern for space weather. Recently, Li et al. proposed a 'twin-CME' scenario for ground-level events. Here we extend that study to large SEP events in solar cycle 23. Depending on whether preceding coronal mass ejections (CMEs) within 9 hr exist and whether ions >10 MeV nucleon –1 exceed 10 pfu, we categorize fast CMEs with speed >900 km s –1 and width >60° from the western hemisphere source regions into four groups: groups I and II are 'twin' and single CMEs that lead to large SEPs; groups III and IV are 'twin' and single CMEs that do not lead to large SEPs. The major findings of this paper are: first, large SEP events tend to be 'twin-CME' events. Of 59 western large SEP events in solar cycle 23, 43 are 'twin-CME' (group I) events and 16 are single-CME (group II) events. Second, not all 'twin CMEs' produced large SEPs: 28 twin CMEs did not produce large SEPs (group III events). Some of them produced excesses of particles up to a few MeV nucleon –1 . Third, there were 39 single fast CMEs that did not produce SEPs (group IV events). Some of these also showed an excess of particles up to a few MeV nucleon –1 . For all four groups of events, we perform statistical analyses on properties such as the angular width, the speed, the existence of accompanying metric type II radio bursts, and the associated flare class for the main CMEs and the preceding CMEs.

  10. NST: Thermal Modeling for a Large Aperture Solar Telescope

    Science.gov (United States)

    Coulter, Roy

    2011-05-01

    Late in the 1990s the Dutch Open Telescope demonstrated that internal seeing in open, large aperture solar telescopes can be controlled by flushing air across the primary mirror and other telescope structures exposed to sunlight. In that system natural wind provides a uniform air temperature throughout the imaging volume, while efficiently sweeping heated air away from the optics and mechanical structure. Big Bear Solar Observatory's New Solar Telescope (NST) was designed to realize that same performance in an enclosed system by using both natural wind through the dome and forced air circulation around the primary mirror to provide the uniform air temperatures required within the telescope volume. The NST is housed in a conventional, ventilated dome with a circular opening, in place of the standard dome slit, that allows sunlight to fall only on an aperture stop and the primary mirror. The primary mirror is housed deep inside a cylindrical cell with only minimal openings in the side at the level of the mirror. To date, the forced air and cooling systems designed for the NST primary mirror have not been implemented, yet the telescope regularly produces solar images indicative of the absence of mirror seeing. Computational Fluid Dynamics (CFD) analysis of the NST primary mirror system along with measurements of air flows within the dome, around the telescope structure, and internal to the mirror cell are used to explain the origin of this seemingly incongruent result. The CFD analysis is also extended to hypothetical systems of various scales. We will discuss the results of these investigations.

  11. Large-Scale Nanophotonic Solar Selective Absorbers for High-Efficiency Solar Thermal Energy Conversion.

    Science.gov (United States)

    Li, Pengfei; Liu, Baoan; Ni, Yizhou; Liew, Kaiyang Kevin; Sze, Jeff; Chen, Shuo; Shen, Sheng

    2015-08-19

    An omnidirectional nanophotonic solar selective absorber is fabricated on a large scale using a template-stripping method. The nanopyramid nickel structure achieves an average absorptance of 95% at a wavelength range below 1.3 μm and a low emittance less than 10% at wavelength >2.5 μm. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. Testing, development and demonstration of large scale solar district heating systems

    DEFF Research Database (Denmark)

    Furbo, Simon; Fan, Jianhua; Perers, Bengt

    2015-01-01

    In 2013-2014 the project “Testing, development and demonstration of large scale solar district heating systems” was carried out within the Sino-Danish Renewable Energy Development Programme, the so called RED programme jointly developed by the Chinese and Danish governments. In the project Danish...... know how on solar heating plants and solar heating test technology have been transferred from Denmark to China, large solar heating systems have been promoted in China, test capabilities on solar collectors and large scale solar heating systems have been improved in China and Danish-Chinese cooperation...

  13. WILL THE LARGE SYNOPTIC SURVEY TELESCOPE DETECT EXTRA-SOLAR PLANETESIMALS ENTERING THE SOLAR SYSTEM?

    International Nuclear Information System (INIS)

    Moro-Martin, Amaya; Turner, Edwin L.; Loeb, Abraham

    2009-01-01

    Planetesimal formation is a common by-product of the star formation process. Taking the dynamical history of the solar system as a guideline-in which the planetesimal belts were heavily depleted due to gravitational perturbation with the giant planets-and assuming similar processes have taken place in other planetary systems, one would expect the interstellar space to be filled with extra-solar planetesimals. However, not a single one of these objects has been detected so far entering the solar system, even though it would clearly be distinguishable from a solar system comet due to its highly hyperbolic orbit. The Large Synoptic Survey Telescope (LSST) will provide wide coverage maps of the sky to a very high sensitivity, ideal to detect moving objects like comets, both active and inactive. In anticipation of these observations, we estimate how many inactive 'interstellar comets' might be detected during the duration of the survey. The calculation takes into account estimates (from observations and models) of the number density of stars, the amount of solids available to form planetesimals, the frequency of planet and planetesimal formation, the efficiency of planetesimal ejection, and the possible size distribution of these small bodies.

  14. Time-of-flight neutron spectra measurements in Zenith

    Energy Technology Data Exchange (ETDEWEB)

    Barclay, F R; Coates, M S; Diment, K M; Durrani, S A; Gayther, D B; Poole, M J; Reed, D L

    1962-01-15

    Neutron spectra in the second core loading of ZENITH have been measured using a neutron chopper. Spectra at two positions in the reactore core were obtained over a range of temperatures extending to 650 deg C.

  15. Large solar heating system with seasonal storage for buld drying in Lisse, the Netherlands

    NARCIS (Netherlands)

    Bokhoven, T.P.; Geus, A.C. de

    1996-01-01

    Within IEA Task 14 (Advanced Solar Systems) of the IEA Solar Heating and Cooling Programme a working group was established dealing with large advanced solar energy systems (the Large Systems Working group). The goal of this working group was to generate a common base of experiences for the design

  16. Simultaneous Solar Maximum Mission (SMM) and Very Large Array (VLA) observations of solar active regions

    Science.gov (United States)

    Willson, Robert F.

    1991-01-01

    Very Large Array observations at 20 cm wavelength can detect the hot coronal plasma previously observed at soft x ray wavelengths. Thermal cyclotron line emission was detected at the apex of coronal loops where the magnetic field strength is relatively constant. Detailed comparison of simultaneous Solar Maximum Mission (SMM) Satellite and VLA data indicate that physical parameters such as electron temperature, electron density, and magnetic field strength can be obtained, but that some coronal loops remain invisible in either spectral domain. The unprecedent spatial resolution of the VLA at 20 cm wavelength showed that the precursor, impulsive, and post-flare components of solar bursts originate in nearby, but separate loops or systems of loops.. In some cases preburst heating and magnetic changes are observed from loops tens of minutes prior to the impulsive phase. Comparisons with soft x ray images and spectra and with hard x ray data specify the magnetic field strength and emission mechanism of flaring coronal loops. At the longer 91 cm wavelength, the VLA detected extensive emission interpreted as a hot 10(exp 5) K interface between cool, dense H alpha filaments and the surrounding hotter, rarefield corona. Observations at 91 cm also provide evidence for time-correlated bursts in active regions on opposite sides of the solar equator; they are attributed to flare triggering by relativistic particles that move along large-scale, otherwise-invisible, magnetic conduits that link active regions in opposite hemispheres of the Sun.

  17. Simultaneous Solar Maximum Mission (SMM) and very large array observations of solar active regions

    Science.gov (United States)

    Lang, K. R.

    1986-01-01

    The research deals mainly with Very Large Array and Solar Maximum Mission observations of the ubiquitous coronal loops that dominate the structure of the low corona. As illustrated, the observations of thermal cyclotron lines at microwave wavelengths provide a powerful new method of accurately specifying the coronal magnetic field strength. Processes are delineated that trigger solar eruptions from coronal loops, including preburst heating and the magnetic interaction of coronal loops. Evidence for coherent burst mechanisms is provided for both the Sun and nearby stars, while other observations suggest the presence of currents that may amplify the coronal magnetic field to unexpectedly high levels. The existence is reported of a new class of compact, variable moving sources in regions of apparently weak photospheric field.

  18. Advanced Materials and Production Technology for Very Large Solar Sail Structures, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Solar sails are an attractive means for propulsion of future spacecraft. One potential device for deploying and supporting very large solar sails is the CoilAble...

  19. SPS-ALPHA: The First Practical Solar Power Satellite via Arbitrarily Large PHased Array

    Data.gov (United States)

    National Aeronautics and Space Administration — SPS-ALPHA (Solar Power Satellite via Arbitrarily Large Phased Array) is a novel, bio-mimetic approach to the challenge of space solar power. If successful, this...

  20. Development of large area, high efficiency amorphous silicon solar cell

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, K.S.; Kim, S.; Kim, D.W. [Yu Kong Taedok Institute of Technology (Korea, Republic of)

    1996-02-01

    The objective of the research is to develop the mass-production technologies of high efficiency amorphous silicon solar cells in order to reduce the costs of solar cells and dissemination of solar cells. Amorphous silicon solar cell is the most promising option of thin film solar cells which are relatively easy to reduce the costs. The final goal of the research is to develop amorphous silicon solar cells having the efficiency of 10%, the ratio of light-induced degradation 15% in the area of 1200 cm{sup 2} and test the cells in the form of 2 Kw grid-connected photovoltaic system. (author) 35 refs., 8 tabs., 67 figs.

  1. Large amplitude oscillatory motion along a solar filament

    Science.gov (United States)

    Vršnak, B.; Veronig, A. M.; Thalmann, J. K.; Žic, T.

    2007-08-01

    Context: Large amplitude oscillations of solar filaments is a phenomenon that has been known for more than half a century. Recently, a new mode of oscillations, characterized by periodical plasma motions along the filament axis, was discovered. Aims: We analyze such an event, recorded on 23 January 2002 in Big Bear Solar Observatory Hα filtergrams, to infer the triggering mechanism and the nature of the restoring force. Methods: Motion along the filament axis of a distinct buldge-like feature was traced, to quantify the kinematics of the oscillatory motion. The data were fitted by a damped sine function to estimate the basic parameters of the oscillations. To identify the triggering mechanism, morphological changes in the vicinity of the filament were analyzed. Results: The observed oscillations of the plasma along the filament were characterized by an initial displacement of 24 Mm, an initial velocity amplitude of 51 km s-1, a period of 50 min, and a damping time of 115 min. We interpret the trigger in terms of poloidal magnetic flux injection by magnetic reconnection at one of the filament legs. The restoring force is caused by the magnetic pressure gradient along the filament axis. The period of oscillations, derived from the linearized equation of motion (harmonic oscillator) can be expressed as P=π√{2}L/v_Aϕ≈4.4L/v_Aϕ, where v_Aϕ =Bϕ0/√μ_0ρ represents the Alfvén speed based on the equilibrium poloidal field Bϕ0. Conclusions: Combination of our measurements with some previous observations of the same kind of oscillations shows good agreement with the proposed interpretation. Movie to Fig. 1 is only available in electronic form at http://www.aanda.org

  2. Solar System science with the Large Synoptic Survey Telescope

    Science.gov (United States)

    Jones, Lynne; Brown, Mike; Ivezić, Zeljko; Jurić, Mario; Malhotra, Renu; Trilling, David

    2015-11-01

    The Large Synoptic Survey Telescope (LSST; http://lsst.org) will be a large-aperture, wide-field, ground-based telescope that will survey half the sky every few nights in six optical bands from 320 to 1050 nm. It will explore a wide range of astrophysical questions, ranging from performing a census of the Solar System, to examining the nature of dark energy. It is currently in construction, slated for first light in 2019 and full operations by 2022.The LSST will survey over 20,000 square degrees with a rapid observational cadence, to typical limiting magnitudes of r~24.5 in each visit (9.6 square degree field of view). Automated software will link the individual detections into orbits; these orbits, as well as precisely calibrated astrometry (~50mas) and photometry (~0.01-0.02 mag) in multiple bandpasses will be available as LSST data products. The resulting data set will have tremendous potential for planetary astronomy; multi-color catalogs of hundreds of thousands of NEOs and Jupiter Trojans, millions of asteroids, tens of thousands of TNOs, as well as thousands of other objects such as comets and irregular satellites of the major planets.LSST catalogs will increase the sample size of objects with well-known orbits 10-100 times for small body populations throughout the Solar System, enabling a major increase in the completeness level of the inventory of most dynamical classes of small bodies and generating new insights into planetary formation and evolution. Precision multi-color photometry will allow determination of lightcurves and colors, as well as spin state and shape modeling through sparse lightcurve inversion. LSST is currently investigating survey strategies to optimize science return across a broad range of goals. To aid in this investigation, we are making a series of realistic simulated survey pointing histories available together with a Python software package to model and evaluate survey detections for a user-defined input population. Preliminary

  3. Solid State Large Area Pulsed Solar Simulator for 3-, 4- and 6-Junction Solar Cell Arrays, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — The Phase I was successful in delivering a complete prototype of the proposed innovation, an LED-based, solid state, large area, pulsed, solar simulator (ssLAPSS)....

  4. Open principle for large high-resolution solar telescopes

    NARCIS (Netherlands)

    Hammerschlag, R.H.; Bettonvil, F.C.M.; Jägers, A.P.L.; Sliepen, G.

    2009-01-01

    Vacuum solar telescopes solve the problem of image deterioration inside the telescope due to refractive index fluctuations of the air heated by the solar light. However, such telescopes have a practical diameter limit somewhat over 1 m. The Dutch Open Telescope (DOT) was the pioneering demonstrator

  5. Large Extra Dimensions, Sterile Neutrinos and Solar Neutrino Data

    International Nuclear Information System (INIS)

    Caldwell, D. O.; Mohapatra, R. N.; Yellin, S. J.

    2001-01-01

    Solar, atmospheric, and LSND neutrino oscillation results require a light sterile neutrino, ν B , which can exist in the bulk of extra dimensions. Solar ν e , confined to the brane, can oscillate in the vacuum to the zero mode of ν B and via successive Mikheyev-Smirnov-Wolfenstein transitions to Kaluza-Klein states of ν B . This new way to fit solar data is provided by both low and intermediate string scale models. From average rates seen in the three types of solar experiments, the Super-Kamiokande spectrum is predicted with 73% probability, but dips characteristic of the 0.06 mm extra dimension should be seen in the SNO spectrum

  6. Large extra dimensions, sterile neutrinos and solar neutrino data.

    Science.gov (United States)

    Caldwell, D O; Mohapatra, R N; Yellin, S J

    2001-07-23

    Solar, atmospheric, and LSND neutrino oscillation results require a light sterile neutrino, nu(B), which can exist in the bulk of extra dimensions. Solar nu(e), confined to the brane, can oscillate in the vacuum to the zero mode of nu(B) and via successive Mikheyev-Smirnov-Wolfenstein transitions to Kaluza-Klein states of nu(B). This new way to fit solar data is provided by both low and intermediate string scale models. From average rates seen in the three types of solar experiments, the Super-Kamiokande spectrum is predicted with 73% probability, but dips characteristic of the 0.06 mm extra dimension should be seen in the SNO spectrum.

  7. Non-uniform Solar Temperature Field on Large Aperture, Fully ...

    Indian Academy of Sciences (India)

    states for the telescope structure during its operation process, and the .... 4.1 Finite element model (FEM) in solar thermal analysis. Figure 4 ... ysis established in ANSYS, MATLAB and FORTRAN; it was built with specific ... Simulation element.

  8. Temperature coefficients of reactivity in the fourth loading of ZENITH

    International Nuclear Information System (INIS)

    Caro Manso, R.; Freemantle, R.G.; Rogers, J.D.

    1962-10-01

    Measurements have been made of the temperature coefficients of reactivity associated with the core plus end reflectors and the side reflector of the fourth core loading of ZENITH, which had a carbon/U235 atomic ratio of 7788 and no other absorber. (author)

  9. A report on the first loading of ZENITH

    International Nuclear Information System (INIS)

    Absalom, R.M.; Barclay, F.R.; Cameron, I.R.; Della Loggia, V.E.; Hage, W.; Kinchin, G.H.; Sanders, J.E.; Tiren, L.I.; Wilson, D.J.

    1960-12-01

    The loading to criticality of the first core of the zero energy reactor ZENITH, and the results of the subsequent experimental programme are described. The composition of the reactor core corresponds to graphite: U235 and Th232: U235 atomic ratios of 3843 and 9.51 respectively. (author)

  10. A report on the first loading of ZENITH

    Energy Technology Data Exchange (ETDEWEB)

    Absalom, R M; Barclay, F R; Cameron, I R; Della Loggia, V E; Hage, W; Kinchin, G H; Sanders, J E; Tiren, L I; Wilson, D J [Industrial Power Reactors Division, Atomic Energy Establishment, Winfrith, Dorchester, Dorset (United Kingdom)

    1960-12-15

    The loading to criticality of the first core of the zero energy reactor ZENITH, and the results of the subsequent experimental programme are described. The composition of the reactor core corresponds to graphite: U235 and Th232: U235 atomic ratios of 3843 and 9.51 respectively. (author)

  11. Temperature coefficients of reactivity in the fourth loading of ZENITH

    Energy Technology Data Exchange (ETDEWEB)

    Caro Manso, R; Freemantle, R G; Rogers, J D [Graphite Reactor Physics Division, Atomic Energy Establishment, Winfrith, Dorchester, Dorset (United Kingdom)

    1962-10-15

    Measurements have been made of the temperature coefficients of reactivity associated with the core plus end reflectors and the side reflector of the fourth core loading of ZENITH, which had a carbon/U235 atomic ratio of 7788 and no other absorber. (author)

  12. An interim report on the Zenith Exponential Experiments

    Energy Technology Data Exchange (ETDEWEB)

    Absalom, R M; Cameron, I R; Kinchin, G H; Sanders, J E; Wilson, D J [Atomic Energy Establishment, Winfrith, Dorchester, Dorset (United Kingdom)

    1959-06-15

    The following memorandum gives an interim account of the exponential experiments with Zenith-type fuel elements being carried out at Winfrith. Results quoted are still subject to revision: however it is hoped that the description of the work at this stage will stimulate discussion and suggestions for further measurements before the experiment is dismantled later in the year. The measurements are being undertaken in order to form some initial understanding of the reactor physics of uranium 235-thorium-graphite systems of the type later to be studied in Zenith. There have been no previous investigations of this type of system in the U.K. though measurements on enriched uranium-graphite systems have been reported from the U.S.A.. A practical result of the measurements will be a revision of the estimated critical loadings for Zenith, since the exponential systems studied cover the range of loadings proposed for the first critical assemblies. The theoretical work on these systems includes a two-group analysis being carried on in the Zenith group and a multigroup analysis being made by the H.T.G.C. Technical Assessments Group, including a Monte Carlo study of resonance capture.

  13. Prospects for investment in large-scale, grid-connected solar power in Africa

    DEFF Research Database (Denmark)

    Hansen, Ulrich Elmer; Nygaard, Ivan; Pedersen, Mathilde Brix

    since the 1990s have changed the competiveness of solar PV in all markets, ranging from individual households via institutions to mini-grids and grid-connected installations. In volume and investment, the market for large-scale grid-connected solar power plants is by far the most important......-scale investments in grid-connected solar power plants and local assembly facilities for PV panels, have exceeded even optimistic scenarios. Finally, therefore, there seem to be bright prospects for investment in large-scale grid-connected solar power in Africa....

  14. Mechanisms limiting the performance of large grain polycrystalline silicon solar cells

    Science.gov (United States)

    Culik, J. S.; Alexander, P.; Dumas, K. A.; Wohlgemuth, J. W.

    1984-01-01

    The open-circuit voltage and short-circuit current of large-grain (1 to 10 mm grain diameter) polycrystalline silicon solar cells is determined by the minority-carrier diffusion length within the bulk of the grains. This was demonstrated by irradiating polycrystalline and single-crystal (Czochralski) silicon solar cells with 1 MeV electrons to reduce their bulk lifetime. The variation of short-circuit current with minority-carrier diffusion length for the polycrystalline solar cells is identical to that of the single-crystal solar cells. The open-circuit voltage versus short-circuit current characteristic of the polycrystalline solar cells for reduced diffusion lengths is also identical to that of the single-crystal solar cells. The open-circuit voltage of the polycrystalline solar cells is a strong function of quasi-neutral (bulk) recombination, and is reduced only slightly, if at all, by grain-boundary recombination.

  15. Deduction of solar neutron fluences from large gamma-ray flares

    International Nuclear Information System (INIS)

    Yoshimori, Masato; Watanabe, Hiroyuki; Takahashi, Kazuyoshi.

    1986-01-01

    Solar neutron fluences from large gamma-ray flares are deduced from accelerated proton spectra and numbers derived from the gamma-ray observations. The deduced solar neutron fluences range from 1 to 200 neutrons cm -2 . The present result indicates a possibility that high sensitivity ground-based neutron monitors can detect solar neutron events, just as detected by the Jungfraujoch and Rome neutron monitors. (author)

  16. Magnetic Properties of Solar Active Regions that Govern Large Solar Flares and Eruptions

    Science.gov (United States)

    Toriumi, Shin; Schrijver, Carolus J.; Harra, Louise; Hudson, Hugh S.; Nagashima, Kaori

    2017-08-01

    Strong flares and CMEs are often produced from active regions (ARs). In order to better understand the magnetic properties and evolutions of such ARs, we conducted statistical investigations on the SDO/HMI and AIA data of all flare events with GOES levels >M5.0 within 45 deg from the disk center for 6 years from May 2010 (from the beginning to the declining phase of solar cycle 24). Out of the total of 51 flares from 29 ARs, more than 80% have delta-sunspots and about 15% violate Hale’s polarity rule. We obtained several key findings including (1) the flare duration is linearly proportional to the separation of the flare ribbons (i.e., scale of reconnecting magnetic fields) and (2) CME-eruptive events have smaller sunspot areas. Depending on the magnetic properties, flaring ARs can be categorized into several groups, such as spot-spot, in which a highly-sheared polarity inversion line is formed between two large sunspots, and spot-satellite, where a newly-emerging flux next to a mature sunspot triggers a compact flare event. These results point to the possibility that magnetic structures of the ARs determine the characteristics of flares and CMEs. In the presentation, we will also show new results from the systematic flux emergence simulations of delta-sunspot formation and discuss the evolution processes of flaring ARs.

  17. A review of large-scale solar heating systems in Europe

    International Nuclear Information System (INIS)

    Fisch, M.N.; Guigas, M.; Dalenback, J.O.

    1998-01-01

    Large-scale solar applications benefit from the effect of scale. Compared to small solar domestic hot water (DHW) systems for single-family houses, the solar heat cost can be cut at least in third. The most interesting projects for replacing fossil fuels and the reduction of CO 2 -emissions are solar systems with seasonal storage in combination with gas or biomass boilers. In the framework of the EU-APAS project Large-scale Solar Heating Systems, thirteen existing plants in six European countries have been evaluated. lie yearly solar gains of the systems are between 300 and 550 kWh per m 2 collector area. The investment cost of solar plants with short-term storage varies from 300 up to 600 ECU per m 2 . Systems with seasonal storage show investment costs twice as high. Results of studies concerning the market potential for solar heating plants, taking new collector concepts and industrial production into account, are presented. Site specific studies and predesign of large-scale solar heating plants in six European countries for housing developments show a 50% cost reduction compared to existing projects. The cost-benefit-ratio for the planned systems with long-term storage is between 0.7 and 1.5 ECU per kWh per year. (author)

  18. Survey of large-scale solar water heaters installed in Taiwan, China

    Energy Technology Data Exchange (ETDEWEB)

    Chang Keh-Chin; Lee Tsong-Sheng; Chung Kung-Ming [Cheng Kung Univ., Tainan (China); Lien Ya-Feng; Lee Chine-An [Cheng Kung Univ. Research and Development Foundation, Tainan (China)

    2008-07-01

    Almost all the solar collectors installed in Taiwan, China were used for production of hot water for homeowners (residential systems), in which the area of solar collectors is less than 10 square meters. From 2001 to 2006, there were only 39 large-scale systems (defined as the area of solar collectors being over 100 m{sup 2}) installed. Their utilization purposes are for rooming house (dormitory), swimming pool, restaurant, and manufacturing process. A comprehensive survey of those large-scale solar water heaters was conducted in 2006. The objectives of the survey were to asses the systems' performance and to have the feedback from the individual users. It is found that lack of experience in system design and maintenance are the key factors for reliable operation of a system. For further promotion of large-scale solar water heaters in Taiwan, a more compressive program on a system design for manufacturing process should be conducted. (orig.)

  19. TIME DISTRIBUTIONS OF LARGE AND SMALL SUNSPOT GROUPS OVER FOUR SOLAR CYCLES

    International Nuclear Information System (INIS)

    Kilcik, A.; Yurchyshyn, V. B.; Abramenko, V.; Goode, P. R.; Cao, W.; Ozguc, A.; Rozelot, J. P.

    2011-01-01

    Here we analyze solar activity by focusing on time variations of the number of sunspot groups (SGs) as a function of their modified Zurich class. We analyzed data for solar cycles 20-23 by using Rome (cycles 20 and 21) and Learmonth Solar Observatory (cycles 22 and 23) SG numbers. All SGs recorded during these time intervals were separated into two groups. The first group includes small SGs (A, B, C, H, and J classes by Zurich classification), and the second group consists of large SGs (D, E, F, and G classes). We then calculated small and large SG numbers from their daily mean numbers as observed on the solar disk during a given month. We report that the time variations of small and large SG numbers are asymmetric except for solar cycle 22. In general, large SG numbers appear to reach their maximum in the middle of the solar cycle (phases 0.45-0.5), while the international sunspot numbers and the small SG numbers generally peak much earlier (solar cycle phases 0.29-0.35). Moreover, the 10.7 cm solar radio flux, the facular area, and the maximum coronal mass ejection speed show better agreement with the large SG numbers than they do with the small SG numbers. Our results suggest that the large SG numbers are more likely to shed light on solar activity and its geophysical implications. Our findings may also influence our understanding of long-term variations of the total solar irradiance, which is thought to be an important factor in the Sun-Earth climate relationship.

  20. Progress of site survey for large solar telescopes in western China

    Science.gov (United States)

    Liu, Yu; Song, Tengfei; Zhang, Xuefei; Liu, Shunqing; Zhao, Mingyu; Tian, Zhanjun; Miao, Yuhu; Li, Hongbo; Huang, Jing; Su, Baoyu; Lu, Yongyin; Li, Xiaobo; Song, Qiwu

    Excellent sites are necessary for developing and installing ground-based large telescopes. For very-high-resolution solar observations, it had been unclear whether there exist good candidate sites in the west areas in China, including the Tibetan Plateau and the Pamirs Plateau. The project of solar site survey for the next-generation large solar telescopes, i.e., the Chinese Giant Solar Telescope (CGST) and the large coronagraph, has been launched since 2011. Based on the close collaboration among Chinese solar society and the scientists from NSO, HAO and other institutes, we have successfully developed the standard instruments for solar site survey and applied them to more than 50 different sites distributed in Xinjiang, Tibet, Qinghai, Sichuan, Yunnan and Ningxia provinces. We have built two long-term monitoring sites in Tibet and the large Shangri-La to take systematic site data. Clear evidence, including the key parameters of seeing factor, sky brightness and water vapor content, has indicated that a few potential sites in the large Tibetan areas should obtain the excellent astronomical conditions for our purpose to develop CGST and large coronagraph. We introduce the fresh site survey results in this report.

  1. Large-scale use of solar energy with central receivers

    Science.gov (United States)

    Kreith, F.; Meyer, R. T.

    1983-12-01

    The working principles of solar central receiver power plants are outlined and applications are discussed. Heliostat arrays direct sunlight into a receiver cavity mounted on a tower, heating the working fluid in the tower to temperatures exceeding 500 C. The formulation for the image plane and the geometric concentration ratio for a heliostat field are provided, noting that commercial electric power plants will require concentration ratios of 200-1000. Automated controls consider imperfections in the mirrors, tracking errors, and seasonal insolation intensity and angular variations. Membranes may be used instead of rigid heliostat mirrors to reduce costs, while trade-offs exist between the efficiencies of cavity and exterior receivers on the tower. Sensible heat storage has proved most effective for cloudy or nighttime operations. Details of the DOE Solar One 10 MW plant, which began operation in 1982, are provided, with mention given to the 33.6 continuous hours of power generation that have been achieved. Projected costs of commercial installations are $700/kWt, and possible applications include recovering and refining oil, processing natural gas, uranium ore, and sugar cane, drying gypsum board, and manufacturing ammonia.

  2. Development of polymers for large scale roll-to-roll processing of polymer solar cells

    DEFF Research Database (Denmark)

    Carlé, Jon Eggert

    Development of polymers for large scale roll-to-roll processing of polymer solar cells Conjugated polymers potential to both absorb light and transport current as well as the perspective of low cost and large scale production has made these kinds of material attractive in solar cell research....... The research field of polymer solar cells (PSCs) is rapidly progressing along three lines: Improvement of efficiency and stability together with the introduction of large scale production methods. All three lines are explored in this work. The thesis describes low band gap polymers and why these are needed....... Polymer of this type display broader absorption resulting in better overlap with the solar spectrum and potentially higher current density. Synthesis, characterization and device performance of three series of polymers illustrating how the absorption spectrum of polymers can be manipulated synthetically...

  3. Advances in Large-Scale Solar Heating and Long Term Storage in Denmark

    DEFF Research Database (Denmark)

    Heller, Alfred

    2000-01-01

    According to (the) information from the European Large-Scale Solar Heating Network, (See http://www.hvac.chalmers.se/cshp/), the area of installed solar collectors for large-scale application is in Europe, approximately 8 mill m2, corresponding to about 4000 MW thermal power. The 11 plants...... the last 10 years and the corresponding cost per collector area for the final installed plant is kept constant, even so the solar production is increased. Unfortunately large-scale seasonal storage was not able to keep up with the advances in solar technology, at least for pit water and gravel storage...... of the total 51 plants are equipped with long-term storage. In Denmark, 7 plants are installed, comprising of approx. 18,000-m2 collector area with new plants planned. The development of these plants and the involved technologies will be presented in this paper, with a focus on the improvements for Danish...

  4. Large-scale brightness inhomogeneities in the solar atmosphere

    International Nuclear Information System (INIS)

    Mitchell, W.E. Jr.

    1982-01-01

    The intensity residuals are analyzed from a series of solar limb-darkening measurements in the wavelength range 5656 to 2997 A. The lengths of residual strings of the same sign exceed expectation by several orders of magnitude. The power spectrum fo the residuals shows a weak excess around 6000 km. For further study the 34000 limb-darkening residuals are subdivided into 5100 bright and faint cells. The frequency distribution of cell sizes peaks around 4500 km and increases from center to limb, the faint cells showing the greater center-limb effect. The cells are also studied as to contrast. A synoptic view indicates that only 12% of the cells are identifiable after a half hour. Phenomena that may combine to produce the observed wide spectrum of brightness inhomogeneities are briefly discussed. (orig.)

  5. Solar total energy-large scale experiment, Shenandoah, Georgia

    Science.gov (United States)

    Hensley, W. R.

    1980-01-01

    The design and development of a 7 meter diameter parabolic dish solar collector are discussed. Each of the four main subsystems of the collector: (1) reflector, (2) mount and drives, (3) receiver and (4) the controls, is discussed briefly with the major emphasis on the receiver design. To minimize development risks and production costs, a dish design based on use of stamped aluminum petals (sectors) was chosen. This design is similar to the design of a communication antenna already commercially produced. The reflective surface of the petals has a total reflectance of .86 and a specularity (dispersion) of 8 mrd. This performance is obtained by mechanical polishing and chemical brightening of the petal surface, followed by application of a clear RTV silicone protective coating. Selection of the material and weather proofing coated are discussed. Results from performance tests on an engineering development dish collector are presented and compared with pretest predictions.

  6. Stratospheric NO2 vertical profile retrieved from ground-based Zenith-Sky DOAS observations at Kiruna, Sweden

    Science.gov (United States)

    Gu, Myojeong; Enell, Carl-Fredrik; Hendrick, François; Pukite, Janis; Van Roozendael, Michel; Platt, Ulrich; Raffalski, Uwe; Wagner, Thomas

    2014-05-01

    Stratospheric NO2 destroys ozone and acts as a buffer against halogen-catalyzed ozone loss through the formation of reservoir species (ClONO2, BrONO2). Since the importance of both mechanisms depends on the altitude, the investigation of stratospheric NO2 vertical distribution can provide more insight into the role of nitrogen compounds in the destruction of ozone. Here we present stratospheric NO2 vertical profiles retrieved from twilight ground-based zenith-sky DOAS observations at Kiruna, Sweden (68.84°N, 20.41°E) covering 1997 - 2013 periods. This instrument observes zenith scattered sunlight. The sensitivity for stratospheric trace gases is highest during twilight due to the maximum altitude of the scattering profile and the light path through the stratosphere, which vary with the solar zenith angle. The profiling algorithm, based on the Optimal Estimation Method, has been developed by IASB-BIRA and successfully applied at other stations (Hendrick et al., 2004). The basic principle behind this profiling approach is that during twilight, the mean Rayleigh scattering altitude scans the stratosphere rapidly, providing height-resolved information on the absorption by stratospheric NO2. In this study, the long-term evolution of the stratospheric NO2 profile at polar latitude will be investigated. Hendrick, F., B. Barret, M. Van Roozendael, H. Boesch, A. Butz, M. De Mazière, F. Goutail, C. Hermans, J.-C. Lambert, K. Pfeilsticker, and J.-P. Pommereau, Retrieval of nitrogen dioxide stratospheric profiles from ground-based zenith-sky UV-visible observations: Validation of the technique through correlative comparisons, Atmospheric Chemistry and Physics, 4, 2091-2106, 2004

  7. Erosion Results of the MISSE 7 Polymers Experiment and Zenith Polymers Experiment After 1.5 Years of Space Exposure

    Science.gov (United States)

    De Groh, Kim K.; Banks, Bruce A.; Yi, Grace T.; Haloua, Athena; Imka, Emily C.; Mitchell, Gianna G.; Asmar, Olivia C.; Leneghan, Halle A.; Sechkar, Edward A.

    2016-01-01

    Polymers and other oxidizable materials on the exterior of spacecraft in the low Earth orbit (LEO) space environment can be eroded due to reaction with atomic oxygen (AO). Therefore, in order to design durable spacecraft it is important to know the LEO AO erosion yield (E(sub y), volume loss per incident oxygen atom) of materials susceptible to AO reaction. Two spaceflight experiments, the Polymers Experiment and the Zenith Polymers Experiment, were developed to determine the AO E(sub y) of various polymers flown in ram, wake or zenith orientations in LEO. These experiments were flown as part of the Materials International Space Station Experiment 7 (MISSE 7) mission for 1.5 years on the exterior of the International Space Station (ISS). The experiments included Kapton H(TradeMark) witness samples for AO fluence determination in ram and zenith orientations. The Polymers Experiment also included samples to determine whether AO erosion of high and low ash containing polymers is dependent on fluence. This paper provides an overview of the MISSE 7 mission, a description of the flight experiments with details on the polymers flown, the characterization techniques used, the AO fluence for each exposure orientation, and the LEO E(sub y) results. The E(sub y) values ranged from 7.99x10(exp -28)cu cm/atom for TiO2/Al2O3 coated Teflon(TradeMark) fluorinated ethylene propylene (FEP) flown in the ram orientation to 1.22x10(exp -23cu cm/atom for polyvinyl alcohol (PVOH) flown in the zenith orientation. The E(sub y) of similar samples flown in different orientations has been compared to help determine solar exposure and associated heating effects on AO erosion. The E(sub y) data from these ISS spaceflight experiments provides valuable information for LEO spacecraft design purposes.

  8. Application of solar energy for meeting the energetic demand of large hotel objects

    International Nuclear Information System (INIS)

    Aycheh, B.

    1993-01-01

    The extensive review of renewable energy sources especially taking account the solar energy and its practical application have been described. It has been shown that the use of solar batteries for supply the large hotel objects is satisfactory only in geographic regions of very intensive isolation, e.g. in Latakia. For regions in Middle Europe, the calculations of energy needs during whole year have been shown that application of only solar energy is un-sufficient and economically unreasonable. During winter the solar installation should be supported by the sources of energy available in the region. The core full economical analysis has been done. Its results proved that e.g. for the German climate conditions the price of energy unit taken from combined solar installation is very close the price of energy obtained in conventional fossil fuel power plants. 37 refs, 48 figs, 29 tabs

  9. Technology for the large-scale production of multi-crystalline silicon solar cells and modules

    International Nuclear Information System (INIS)

    Weeber, A.W.; De Moor, H.H.C.

    1997-06-01

    In cooperation with Shell Solar Energy (formerly R and S Renewable Energy Systems) and the Research Institute for Materials of the Catholic University Nijmegen the Netherlands Energy Research Foundation (ECN) plans to develop a competitive technology for the large-scale manufacturing of solar cells and solar modules on the basis of multi-crystalline silicon. The project will be carried out within the framework of the Economy, Ecology and Technology (EET) program of the Dutch ministry of Economic Affairs and the Dutch ministry of Education, Culture and Sciences. The aim of the EET-project is to reduce the costs of a solar module by 50% by means of increasing the conversion efficiency as well as the development of cheap processes for large-scale production

  10. A new framework to increase the efficiency of large-scale solar power plants.

    Science.gov (United States)

    Alimohammadi, Shahrouz; Kleissl, Jan P.

    2015-11-01

    A new framework to estimate the spatio-temporal behavior of solar power is introduced, which predicts the statistical behavior of power output at utility scale Photo-Voltaic (PV) power plants. The framework is based on spatio-temporal Gaussian Processes Regression (Kriging) models, which incorporates satellite data with the UCSD version of the Weather and Research Forecasting model. This framework is designed to improve the efficiency of the large-scale solar power plants. The results are also validated from measurements of the local pyranometer sensors, and some improvements in different scenarios are observed. Solar energy.

  11. THE 'TWIN-CME' SCENARIO AND LARGE SOLAR ENERGETIC PARTICLE EVENTS IN SOLAR CYCLE 23

    Energy Technology Data Exchange (ETDEWEB)

    Ding, Liuguan; Jiang, Yong [College of Math and Physics, Nanjing University of Information Science and Technology, Nanjing, Jiangsu 210044 (China); Zhao, Lulu; Li, Gang, E-mail: gang.li@uah.edu [Department of Physics and CSPAR, University of Alabama in Huntsville, AL 35899 (United States)

    2013-01-20

    Energetic particles in large solar energetic particle (SEP) events are a major concern for space weather. Recently, Li et al. proposed a 'twin-CME' scenario for ground-level events. Here we extend that study to large SEP events in solar cycle 23. Depending on whether preceding coronal mass ejections (CMEs) within 9 hr exist and whether ions >10 MeV nucleon{sup -1} exceed 10 pfu, we categorize fast CMEs with speed >900 km s{sup -1} and width >60 Degree-Sign from the western hemisphere source regions into four groups: groups I and II are 'twin' and single CMEs that lead to large SEPs; groups III and IV are 'twin' and single CMEs that do not lead to large SEPs. The major findings of this paper are: first, large SEP events tend to be 'twin-CME' events. Of 59 western large SEP events in solar cycle 23, 43 are 'twin-CME' (group I) events and 16 are single-CME (group II) events. Second, not all 'twin CMEs' produced large SEPs: 28 twin CMEs did not produce large SEPs (group III events). Some of them produced excesses of particles up to a few MeV nucleon{sup -1}. Third, there were 39 single fast CMEs that did not produce SEPs (group IV events). Some of these also showed an excess of particles up to a few MeV nucleon{sup -1}. For all four groups of events, we perform statistical analyses on properties such as the angular width, the speed, the existence of accompanying metric type II radio bursts, and the associated flare class for the main CMEs and the preceding CMEs.

  12. Large-scale Flow and Transport of Magnetic Flux in the Solar ...

    Indian Academy of Sciences (India)

    tribpo

    Abstract. Horizontal large-scale velocity field describes horizontal displacement of the photospheric magnetic flux in zonal and meridian directions. The flow systems of solar plasma, constructed according to the velocity field, create the large-scale cellular-like patterns with up-flow in the center and the down-flow on the ...

  13. HF-induced airglow at magnetic zenith: theoretical considerations

    Directory of Open Access Journals (Sweden)

    E. V. Mishin

    2005-01-01

    Full Text Available Observations of airglow at 630nm (red line and 557.7nm (green line during HF modification experiments at the High Frequency Active Auroral Research Program (HAARP heating facility are analyzed. We propose a theoretical framework for understanding the generation of Langmuir and ion acoustic waves during magnetic zenith injections. We show that observations of HF-induced airglow in an underdense ionosphere as well as a decrease in the height of the emitting volume are consistent with this scenario.

  14. MAGNETIC PROPERTIES OF SOLAR ACTIVE REGIONS THAT GOVERN LARGE SOLAR FLARES AND ERUPTIONS

    Energy Technology Data Exchange (ETDEWEB)

    Toriumi, Shin [National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan); Schrijver, Carolus J. [Lockheed Martin Advanced Technology Center, 3251 Hanover Street, Palo Alto, CA 94304 (United States); Harra, Louise K. [UCL-Mullard Space Science Laboratory, Holmbury St Mary, Dorking, Surrey, RH5 6NT (United Kingdom); Hudson, Hugh [SUPA School of Physics and Astronomy, University of Glasgow (United Kingdom); Nagashima, Kaori, E-mail: shin.toriumi@nao.ac.jp [Max-Planck-Institut für Sonnensystemforschung, Justus-von-Liebig-Weg 3, D-37077 Göttingen (Germany)

    2017-01-01

    Solar flares and coronal mass ejections (CMEs), especially the larger ones, emanate from active regions (ARs). With the aim of understanding the magnetic properties that govern such flares and eruptions, we systematically survey all flare events with Geostationary Orbiting Environmental Satellite levels of ≥M5.0 within 45° from disk center between 2010 May and 2016 April. These criteria lead to a total of 51 flares from 29 ARs, for which we analyze the observational data obtained by the Solar Dynamics Observatory . More than 80% of the 29 ARs are found to exhibit δ -sunspots, and at least three ARs violate Hale’s polarity rule. The flare durations are approximately proportional to the distance between the two flare ribbons, to the total magnetic flux inside the ribbons, and to the ribbon area. From our study, one of the parameters that clearly determine whether a given flare event is CME-eruptive or not is the ribbon area normalized by the sunspot area, which may indicate that the structural relationship between the flaring region and the entire AR controls CME productivity. AR characterization shows that even X-class events do not require δ -sunspots or strong-field, high-gradient polarity inversion lines. An investigation of historical observational data suggests the possibility that the largest solar ARs, with magnetic flux of 2 × 10{sup 23} Mx, might be able to produce “superflares” with energies of the order of 10{sup 34} erg. The proportionality between the flare durations and magnetic energies is consistent with stellar flare observations, suggesting a common physical background for solar and stellar flares.

  15. Analytical Model for Estimating the Zenith Angle Dependence of Terrestrial Cosmic Ray Fluxes.

    Directory of Open Access Journals (Sweden)

    Tatsuhiko Sato

    Full Text Available A new model called "PHITS-based Analytical Radiation Model in the Atmosphere (PARMA version 4.0" was developed to facilitate instantaneous estimation of not only omnidirectional but also angular differential energy spectra of cosmic ray fluxes anywhere in Earth's atmosphere at nearly any given time. It consists of its previous version, PARMA3.0, for calculating the omnidirectional fluxes and several mathematical functions proposed in this study for expressing their zenith-angle dependences. The numerical values of the parameters used in these functions were fitted to reproduce the results of the extensive air shower simulation performed by Particle and Heavy Ion Transport code System (PHITS. The angular distributions of ground-level muons at large zenith angles were specially determined by introducing an optional function developed on the basis of experimental data. The accuracy of PARMA4.0 was closely verified using multiple sets of experimental data obtained under various global conditions. This extension enlarges the model's applicability to more areas of research, including design of cosmic-ray detectors, muon radiography, soil moisture monitoring, and cosmic-ray shielding calculation. PARMA4.0 is available freely and is easy to use, as implemented in the open-access EXcel-based Program for Calculating Atmospheric Cosmic-ray Spectrum (EXPACS.

  16. Tradeoffs and Synergies between biofuel production and large solar infrastructure in deserts.

    Science.gov (United States)

    Ravi, Sujith; Lobell, David B; Field, Christopher B

    2014-01-01

    Solar energy installations in deserts are on the rise, fueled by technological advances and policy changes. Deserts, with a combination of high solar radiation and availability of large areas unusable for crop production are ideal locations for large solar installations. However, for efficient power generation, solar infrastructures use large amounts of water for construction and operation. We investigated the water use and greenhouse gas (GHG) emissions associated with solar installations in North American deserts in comparison to agave-based biofuel production, another widely promoted potential energy source from arid systems. We determined the uncertainty in our analysis by a Monte Carlo approach that varied the most important parameters, as determined by sensitivity analysis. We considered the uncertainty in our estimates as a result of variations in the number of solar modules ha(-1), module efficiency, number of agave plants ha(-1), and overall sugar conversion efficiency for agave. Further, we considered the uncertainty in revenue and returns as a result of variations in the wholesale price of electricity and installation cost of solar photovoltaic (PV), wholesale price of agave ethanol, and cost of agave cultivation and ethanol processing. The life-cycle analyses show that energy outputs and GHG offsets from solar PV systems, mean energy output of 2405 GJ ha(-1) year(-1) (5 and 95% quantile values of 1940-2920) and mean GHG offsets of 464 Mg of CO2 equiv ha(-1) year(-1) (375-562), are much larger than agave, mean energy output from 206 (171-243) to 61 (50-71) GJ ha(-1) year(-1) and mean GHG offsets from 18 (14-22) to 4.6 (3.7-5.5) Mg of CO2 equiv ha(-1) year(-1), depending upon the yield scenario of agave. Importantly though, water inputs for cleaning solar panels and dust suppression are similar to amounts required for annual agave growth, suggesting the possibility of integrating the two systems to maximize the efficiency of land and water use to produce

  17. Dynamical Changes Induced by the Very Large Solar Proton Events in October-November 2003

    Science.gov (United States)

    Jackman, Charles H.; Roble, Raymond G.

    2006-01-01

    The very large solar storms in October-November 2003 caused solar proton events (SPEs) at the Earth and impacted the upper atmospheric polar cap regions. The Thermosphere Ionosphere Mesosphere Electrodynamic General Circulation Mode (TIME-GCM) was used to study the atmospheric dynamical influence of the solar protons that occurred in Oct-Nov 2003, the fourth largest period of SPEs measured in the past 40 years. The highly energetic solar protons caused ionization and changes in the electric field, which led to Joule heating of the mesosphere and lower thermosphere. This heating led to temperature increases up to 4K in the upper mesosphere. The solar proton-induced ionization, as well as dissociation processes, led to the production of odd hydrogen (HO(x)) and odd nitrogen (NO(y)). Substantial (>40%) short-lived ozone decreases followed these enhancements of HO(x) and NO(y) and led to a cooling of the mesosphere and upper stratosphere. This cooling led to temperature decreases up to 2.5K. The solar proton-caused temperature changes led to maximum meridional and zonal wind variations of +/- 2 m/s on background winds up to +/- 30 m/s. The solar proton-induced wind perturbations were computed to taper off over a period of several days past the SPEs. Solar cycle 23 was accompanied by ten very large SPEs between 1998 and 2005, along with numerous smaller events. These solar proton-driven atmospheric variations need to be carefully considered when examining other polar changes.

  18. Shortwave Array Spectroradiometer–Zenith (SASZe) Instrument Handbook

    Energy Technology Data Exchange (ETDEWEB)

    Flynn, Connor J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2016-04-01

    The Shortwave Array Spectroradiometer – Zenith (SASZe) provides measurements of zenith spectral shortwave radiance at 1Hz over a continuous spectral range from approximately 300 nm to 1700 nm. The SASZe design connects an optical collector located outdoors to a pair of spectrometers and data collections system located indoors within a climate-controlled building via an umbilical cable of fiber optic and electrical cables. The light collector incorporates a collimator yielding a 1-degree Full Width at Half Maximum (FWHM) field of view. The data-acquisition electronics and spectrometers include an in-line fiber optic shutter and two Avantes fiber-coupled grating spectroradiometers within a temperature-controlled container. The Avantes Avaspec ULS 2048 charge-coupled device (CCD) spectrometer covers the wavelength range from about 300-1100 nm with a pixel spacing of less than 0.6 nm and a spectral resolution of about 2.4 nm FWHM. The Avantes Avaspec NIR256-1.7 spectrometer covers the wavelength range from about 950 nm to 1700 nm with a pixel spacing of less than 4 nm and a spectral resolution of about 6 nm FWHM.

  19. Experimental programme and analysis, ZENITH II, Core 4

    Energy Technology Data Exchange (ETDEWEB)

    Ingram, G.; Sanders, J. E.; Sherwin, J.

    1974-10-15

    The Phase 3 program of reactor physics experiments on the HTR (or Mk 3 GCR) lattices continued during the first half of 1974 with a study of a series of critical builds in Zenith II aimed at testing predictions of shut-down margins in the local criticality-situations arising during power reactor refueling. The paper describes the experimental program and the subsequent theoretical analysis using methods developed in the United Kingdom for calculating low-enriched uranium HTR fuel systems. The importance of improving the accuracy of predictions of shut-down margins arises from the basic requirement that the core in its most reactive condition and with a specified number of absorbers removed from the array must remain sub-critical with a margin adequate to cover the total uncertainty of +/- 1 Nile (that is, 1 % delta-k). The major uncertainty is that in modelling the complex fuel/absorber configuration, and this is the aspect essentially covered in the Zenith II Core 4 studies.

  20. Energy and zenith angle dependence of atmospheric muons

    CERN Document Server

    Maeda, K

    1973-01-01

    The recently proposed new process for energetic-muon production in the atmosphere should be tested at Mt. Chacaltaya. Rigorous calculations of zenith-angle distribution of atmospheric muons have been made for the altitude of 5200 m above sea level with energy range from 100 GeV to 100 TeV and for zenith angles from 0 degrees to 92.3 degrees . Calculations are based on the extension of the Chapman function to the case of a non-isothermal atmosphere, taking into account (i) energy- dependent nuclear-interaction mean free path of cosmic-ray hadrons in air, (ii) different magnitudes of photonuclear cross-section in the energy-loss process of muons in the atmosphere, (iii) contributions of atmospheric muons arriving below the horizontal directions, and (iv) atmospheric structure and geomagnetic deflection. Results are compared with those corresponding to sea level. Range straggling, particularly its effect on horizontally incident muons, is investigated by Monte Carlo calculation, indicating that its effects and t...

  1. Printable nanostructured silicon solar cells for high-performance, large-area flexible photovoltaics.

    Science.gov (United States)

    Lee, Sung-Min; Biswas, Roshni; Li, Weigu; Kang, Dongseok; Chan, Lesley; Yoon, Jongseung

    2014-10-28

    Nanostructured forms of crystalline silicon represent an attractive materials building block for photovoltaics due to their potential benefits to significantly reduce the consumption of active materials, relax the requirement of materials purity for high performance, and hence achieve greatly improved levelized cost of energy. Despite successful demonstrations for their concepts over the past decade, however, the practical application of nanostructured silicon solar cells for large-scale implementation has been hampered by many existing challenges associated with the consumption of the entire wafer or expensive source materials, difficulties to precisely control materials properties and doping characteristics, or restrictions on substrate materials and scalability. Here we present a highly integrable materials platform of nanostructured silicon solar cells that can overcome these limitations. Ultrathin silicon solar microcells integrated with engineered photonic nanostructures are fabricated directly from wafer-based source materials in configurations that can lower the materials cost and can be compatible with deterministic assembly procedures to allow programmable, large-scale distribution, unlimited choices of module substrates, as well as lightweight, mechanically compliant constructions. Systematic studies on optical and electrical properties, photovoltaic performance in experiments, as well as numerical modeling elucidate important design rules for nanoscale photon management with ultrathin, nanostructured silicon solar cells and their interconnected, mechanically flexible modules, where we demonstrate 12.4% solar-to-electric energy conversion efficiency for printed ultrathin (∼ 8 μm) nanostructured silicon solar cells when configured with near-optimal designs of rear-surface nanoposts, antireflection coating, and back-surface reflector.

  2. A numerical model to evaluate the flow distribution in a large solar collector field

    DEFF Research Database (Denmark)

    Bava, Federico; Dragsted, Janne; Furbo, Simon

    2017-01-01

    This study presents a numerical model to evaluate the flow distribution in a large solar collector field, with solar collectors connected both in series and in parallel. The boundary conditions of the systems, such as flow rate, temperature, fluid type and layout of the collector field can...... be easily changed in the model. The model was developed in Matlab and the calculated pressure drop and flow distribution were compared with measurements from a solar collector field. A good agreement between model and measurements was found. The model was then used to study the flow distribution...... in different conditions. Balancing valves proved to be an effective way to achieve uniform flow distribution also in conditions different from those for which the valves were regulated. For small solar collector fields with limited number of collector rows connected in parallel, balancing valves...

  3. New Earth-abundant Materials for Large-scale Solar Fuels Generation.

    Science.gov (United States)

    Prabhakar, Rajiv Ramanujam; Cui, Wei; Tilley, S David

    2018-05-30

    The solar resource is immense, but the power density of light striking the Earth's surface is relatively dilute, necessitating large area solar conversion devices in order to harvest substantial amounts of power for renewable energy applications. In addition, energy storage is a key challenge for intermittent renewable resources such as solar and wind, which adds significant cost to these energies. As the majority of humanity's present-day energy consumption is based on fuels, an ideal solution is to generate renewable fuels from abundant resources such as sunlight and water. In this account, we detail our recent work towards generating highly efficient and stable Earth-abundant semiconducting materials for solar water splitting to generate renewable hydrogen fuel.

  4. Large scale solar thermal power for the European Union{exclamation_point}

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    1997-06-01

    Southern Europe, on the edge of the sunbelt, represents the ideal location for solar thermal generated power. Last year. SAWIE reported on the THESEUS project, a proposed 50 MWe solar thermal power plant for Frangokastello, southern Crete, which was submitted for support under the European Union`s THERMIE Programme. Funding was approved for the design phase for this innovative power plant, the first large-scale SEGS-style plant on European soil, at the end of last year. However, the THERMIE Programme also provided support for another Southern European plant, proposed by Colon Solar for Huelva in Southern Spain. Whilst hurdles remain to be overcome before both plants are built and commissioned, there is an excellent chance that by the start of the new Millennium, the solar collectors from these two plants could be generating over half a million MWh of energy a year. SAWIE compares the two projects. (author)

  5. Comparison of stratospheric NO2 profiles above Kiruna, Sweden retrieved from ground-based zenith sky DOAS measurements, SAOZ balloon measurements and SCIAMACHY limb observations

    Science.gov (United States)

    Gu, Myojeong; Enell, Carl-Fredrik; Hendrick, François; Pukite, Janis; Van Roozendael, Michel; Platt, Ulrich; Raffalski, Uwe; Wagner, Thomas

    2015-04-01

    Stratospheric NO2 not only destroys ozone but acts as a buffer against halogen catalyzed ozone loss by converting halogen species into stable nitrates. These two roles of stratospheric NO2 depend on the altitude. Hence, the objective of this study is to investigate the vertical distribution of stratospheric NO2. We compare the NO2 profiles derived from the zenith sky DOAS with those obtained from, SAOZ balloon measurements and satellite limb observations. Vertical profiles of stratospheric NO2 are retrieved from ground-based zenith sky DOAS observations operated at Kiruna, Sweden (68.84°N, 20.41°E) since 1996. To determine the profile of stratospheric NO2 measured from ground-based zenith sky DOAS, we apply the Optimal Estimation Method (OEM) to retrieval of vertical profiles of stratospheric NO2 which has been developed by IASB-BIRA. The basic principle behind this profiling approach is the dependence of the mean scattering height on solar zenith angle (SZA). We compare the retrieved profiles to two additional datasets of stratospheric NO2 profile. The first one is derived from satellite limb observations by SCIAMACHY (Scanning Imaging Absorption spectrometer for Atmospheric CHartographY) on EnviSAT. The second is derived from the SAOZ balloon measurements (using a UV/Visible spectrometer) performed at Kiruna in Sweden.

  6. Quality assessment of solar UV irradiance measured with array spectroradiometers

    Science.gov (United States)

    Egli, Luca; Gröbner, Julian; Hülsen, Gregor; Bachmann, Luciano; Blumthaler, Mario; Dubard, Jimmy; Khazova, Marina; Kift, Richard; Hoogendijk, Kees; Serrano, Antonio; Smedley, Andrew; Vilaplana, José-Manuel

    2016-04-01

    The reliable quantification of ultraviolet (UV) radiation at the earth's surface requires accurate measurements of spectral global solar UV irradiance in order to determine the UV exposure to human skin and to understand long-term trends in this parameter. Array spectroradiometers (ASRMs) are small, light, robust and cost-effective instruments, and are increasingly used for spectral irradiance measurements. Within the European EMRP ENV03 project "Solar UV", new devices, guidelines and characterization methods have been developed to improve solar UV measurements with ASRMs, and support to the end user community has been provided. In order to assess the quality of 14 end user ASRMs, a solar UV intercomparison was held on the measurement platform of the World Radiation Center (PMOD/WRC) in Davos, Switzerland, from 10 to 17 July 2014. The results of the blind intercomparison revealed that ASRMs, currently used for solar UV measurements, show a large variation in the quality of their solar UV measurements. Most of the instruments overestimate the erythema-weighted UV index - in particular at large solar zenith angles - due to stray light contribution in the UV-B range. The spectral analysis of global solar UV irradiance further supported the finding that the uncertainties in the UV-B range are very large due to stray light contribution in this wavelength range. In summary, the UV index may be detected by some commercially available ASRMs within 5 % compared to the world reference spectroradiometer, if well characterized and calibrated, but only for a limited range of solar zenith angles. Generally, the tested instruments are not yet suitable for solar UV measurements for the entire range between 290 and 400 nm under all atmospheric conditions.

  7. A simple orbit-attitude coupled modelling method for large solar power satellites

    Science.gov (United States)

    Li, Qingjun; Wang, Bo; Deng, Zichen; Ouyang, Huajiang; Wei, Yi

    2018-04-01

    A simple modelling method is proposed to study the orbit-attitude coupled dynamics of large solar power satellites based on natural coordinate formulation. The generalized coordinates are composed of Cartesian coordinates of two points and Cartesian components of two unitary vectors instead of Euler angles and angular velocities, which is the reason for its simplicity. Firstly, in order to develop natural coordinate formulation to take gravitational force and gravity gradient torque of a rigid body into account, Taylor series expansion is adopted to approximate the gravitational potential energy. The equations of motion are constructed through constrained Hamilton's equations. Then, an energy- and constraint-conserving algorithm is presented to solve the differential-algebraic equations. Finally, the proposed method is applied to simulate the orbit-attitude coupled dynamics and control of a large solar power satellite considering gravity gradient torque and solar radiation pressure. This method is also applicable to dynamic modelling of other rigid multibody aerospace systems.

  8. DESIGN AND DEVELOPMENT OF A LARGE SIZE NON-TRACKING SOLAR COOKER

    Directory of Open Access Journals (Sweden)

    N. M. NAHAR

    2009-09-01

    Full Text Available A large size novel non-tracking solar cooker has been designed, developed and tested. The cooker has been designed in such a way that the width to length ratio for reflector and glass window is about 4 so that maximum radiation falls on the glass window. This has helped in eliminating azimuthal tracking that is required in simple hot box solar cooker towards the Sun every hour because the width to length ratio of reflector is 1. It has been found that stagnation temperatures were 118.5oC and 108oC in large size non-tracking solar cooker and hot box solar cooker respectively. It takes about 2 h for soft food and 3 h for hard food. The cooker is capable of cooking 4.0 kg of food at a time. The efficiency of the large size non-tracking solar cooker has been found to be 27.5%. The cooker saves 5175 MJ of energy per year. The cost of the cooker is Rs. 10000.00 (1.0 US$ = Rs. 50.50. The payback period has been calculated by considering 10% annual interest, 5% maintenance cost and 5% inflation in fuel prices and maintenance cost. The payback period is least, i.e. 1.58 yr., with respect to electricity and maximum, i.e. 4.89 yr., with respect to kerosene. The payback periods are in increasing order with respect to fuel: electricity, coal, firewood, liquid petroleum gas, and kerosene. The shorter payback periods suggests that the use of large size non-tracking solar cooker is economical.

  9. Motivation for the European Union to support large solar power plants

    International Nuclear Information System (INIS)

    Brakmann, Georg

    1997-01-01

    An invited article discusses the opportunities for large, electricity generating solar thermal plants in the European Union. It is claimed that although it is currently not competitive with current oil prices, it is cheaper than photovoltaics. Topics covered include CO 2 emission reduction, likely subsidies required, job creation and taxation. (UK)

  10. Sandia Laboratories in-house activities in support of solar thermal large power applications

    Science.gov (United States)

    Mar, R. W.

    1980-01-01

    The development of thermal energy storage subsystems for solar thermal large power applications is described. The emphasis is on characterizing the behavior of molten nitrate salts with regard to thermal decomposition, environmental interactions, and corrosion. Electrochemical techniques to determine the ionic species in the melt and for use in real time studies of corrosion are also briefly discussed.

  11. Harnessing solar pressure to slew and point large infrared space telescopes

    Science.gov (United States)

    Errico, Simona; Angel, Roger P.; Calvert, Paul D.; Woof, Neville

    2003-03-01

    Large astronomical Gossamer telescopes in space will need to employ large solar shields to safeguard the optics from solar radiation. These types of telescopes demand accurate controls to maintain telescope pointing over long integration periods. We propose an active solar shield system that harnesses radiation pressure to accurately slew and acquire new targets without the need for reaction wheels or thrusters. To provide the required torques, the solar shield is configured as an inverted, 4-sided pyramidal roof. The sloped roof interior surfaces are covered with hinged “tiles” made from piezoelectric film bimorphs with specular metallized surfaces. Nominally, the tiles lie flat against the roof and the sunlight is reflected outward equally from all sloped surfaces. However, when the tiles on one roof pitch are raised, the pressure balance is upset and the sunshade is pushed to one side. By judicious selection of the tiles and control of their lift angle, the solar pressure can be harvested to stabilize the spacecraft orientation or to change its angular momentum. A first order conceptual design performance analysis and the results from the experimental design, fabrication and testing of piezoelectric bimorph hinge elements will be presented. Next phase challenges in engineering design, materials technology, and systems testing will be discussed.

  12. Scalability of multi-junction organic solar cells for large area organic solar modules

    Science.gov (United States)

    Xiao, Xin; Lee, Kyusang; Forrest, Stephen R.

    2015-05-01

    We investigate the scalability of multi-junction organic photovoltaic cells (OPV) with device areas ranging from 1 mm2 to 1 cm2, as well as 25 cm2 active area solar modules. We find that the series resistance losses in 1 cm2 vs. 1 mm2 OPV cell efficiencies are significantly higher in single junction cells than tandem, triple, and four junction cells due to the lower operating voltage and higher current of the former. Using sub-electrodes to reduce series resistance, the power conversion efficiency (PCE) of multi-junction cells is almost independent of area from 1 mm2 to 1 cm2. Twenty-five, 1 cm2 multi-junction cell arrays are integrated in a module and connected in a series-parallel circuit configuration. A yield of 100% with a deviation of PCE from cell to cell of <10% is achieved. The module generates an output power of 162 ± 9 mW under simulated AM1.5G illumination at one sun intensity, corresponding to PCE = 6.5 ± 0.1%, slightly lower than PCE of discrete cells ranging from 6.7% to 7.2%.

  13. Overview of Small and Large-Scale Space Solar Power Concepts

    Science.gov (United States)

    Potter, Seth; Henley, Mark; Howell, Joe; Carrington, Connie; Fikes, John

    2006-01-01

    An overview of space solar power studies performed at the Boeing Company under contract with NASA will be presented. The major concepts to be presented are: 1. Power Plug in Orbit: this is a spacecraft that collects solar energy and distributes it to users in space using directed radio frequency or optical energy. Our concept uses solar arrays having the same dimensions as ISS arrays, but are assumed to be more efficient. If radiofrequency wavelengths are used, it will necessitate that the receiving satellite be equipped with a rectifying antenna (rectenna). For optical wavelengths, the solar arrays on the receiving satellite will collect the power. 2. Mars Clipper I Power Explorer: this is a solar electric Mars transfer vehicle to support human missions. A near-term precursor could be a high-power radar mapping spacecraft with self-transport capability. Advanced solar electric power systems and electric propulsion technology constitute viable elements for conducting human Mars missions that are roughly comparable in performance to similar missions utilizing alternative high thrust systems, with the one exception being their inability to achieve short Earth-Mars trip times. 3. Alternative Architectures: this task involves investigating alternatives to the traditional solar power satellite (SPS) to supply commercial power from space for use on Earth. Four concepts were studied: two using photovoltaic power generation, and two using solar dynamic power generation, with microwave and laser power transmission alternatives considered for each. All four architectures use geostationary orbit. 4. Cryogenic Propellant Depot in Earth Orbit: this concept uses large solar arrays (producing perhaps 600 kW) to electrolyze water launched from Earth, liquefy the resulting hydrogen and oxygen gases, and store them until needed by spacecraft. 5. Beam-Powered Lunar Polar Rover: a lunar rover powered by a microwave or laser beam can explore permanently shadowed craters near the lunar

  14. Structural concepts for very large (400-meter-diameter) solar concentrators

    Science.gov (United States)

    Mikulas, Martin M., Jr.; Hedgepeth, John M.

    1989-01-01

    A general discussion of various types of large space structures is presented. A brief overview of the history of space structures is presented to provide insight into the current state-of-the art. Finally, the results of a structural study to assess the viability of very large solar concentrators are presented. These results include weight, stiffness, part count, and in-space construction time.

  15. Joint Ne/O and Fe/O Analysis to Diagnose Large Solar Energetic Particle Events during Solar Cycle 23

    Energy Technology Data Exchange (ETDEWEB)

    Tan, Lun C.; Shao, Xi [Department of Astronomy, University of Maryland, College Park, MD 20742 (United States); Malandraki, Olga E., E-mail: ltan@umd.edu [IAASARS, National Observatory of Athens, GR-15236, Penteli (Greece)

    2017-02-01

    We have examined 29 large solar energetic particle (SEP) events with the peak proton intensity J {sub pp}(>60 MeV) > 1 pfu during solar cycle 23. The emphasis of our examination is put on a joint analysis of Ne/O and Fe/O data in the energy range (3–40 MeV nucleon{sup −1}) covered by Wind /Low-Energy Matrix Telescope and ACE /Solar Isotope Spectrometer sensors in order to differentiate between the Fe-poor and Fe-rich events that emerged from the coronal mass ejection driven shock acceleration process. An improved ion ratio calculation is carried out by rebinning ion intensity data into the form of equal bin widths in the logarithmic energy scale. Through the analysis we find that the variability of Ne/O and Fe/O ratios can be used to investigate the accelerating shock properties. In particular, the high-energy Ne/O ratio is well correlated with the source plasma temperature of SEPs.

  16. Short- and Medium-term Atmospheric Effects of Very Large Solar Proton Events

    Science.gov (United States)

    Jackman, Charles H.; Marsh, Daniel R.; Vitt, Francis M.; Garcia, Rolando R.; Fleming, Eric L.; Labow, Gordon J.; Randall, Cora E.; Lopez-Puertas, Manuel; Funke, Bernd

    2007-01-01

    Long-term variations in ozone have been caused by both natural and humankind related processes. In particular, the humankind or anthropogenic influence on ozone from chlorofluorocarbons and halons (chlorine and bromine) has led to international regulations greatly limiting the release of these substances. These anthropogenic effects on ozone are most important in polar regions and have been significant since the 1970s. Certain natural ozone influences are also important in polar regions and are caused by the impact of solar charged particles on the atmosphere. Such natural variations have been studied in order to better quantify the human influence on polar ozone. Large-scale explosions on the Sun near solar maximum lead to emissions of charged particles (mainly protons and electrons), some of which enter the Earth's magnetosphere and rain down on the polar regions. "Solar proton events" have been used to describe these phenomena since the protons associated with these solar events sometimes create a significant atmospheric disturbance. We have used the National Center for Atmospheric Research (NCAR) Whole Atmosphere Community Climate Model (WACCM) to study the short- and medium-term (days to a few months) influences of solar proton events between 1963 and 2005 on stratospheric ozone. The four largest events in the past 45 years (August 1972; October 1989; July 2000; and October-November 2003) caused very distinctive polar changes in layers of the Earth's atmosphere known as the stratosphere (12-50 km; -7-30 miles) and mesosphere (50-90 km; 30-55 miles). The solar protons connected with these events created hydrogen- and nitrogen- containing compounds, which led to the polar ozone destruction. The hydrogen-containing compounds have very short lifetimes and lasted for only a few days (typically the duration of the solar proton event). On the other hand, the nitrogen-containing compounds lasted much longer, especially in the Winter. The nitrogen oxides were predicted

  17. Propagation of large amplitude Alfven waves in the solar wind current sheet

    International Nuclear Information System (INIS)

    Malara, Francesco; Primavera, Leonardo; Veltri, Pierluigi

    1996-01-01

    The time evolution of Alfvenic perturbations in the Solar Wind current sheet is studied by using numerical simulations of the compressible magnetohydrodynamic (MHD) equations. The simulations show that the interaction between the large amplitude Alfvenic pertubation and the solar wind current sheet decreases the correlation between velocity and magnetic field fluctuations and produces compressive fluctuations. The characteristics of these compressive fluctuations compare rather well with spatial observations. The behavior of the correlation between density and magnetic field intensity fluctuations and of the their spectra are well reproduced so that the physical mechanisms giving rise to these behaviors can be identified

  18. Investigation of Low-Cost Surface Processing Techniques for Large-Size Multicrystalline Silicon Solar Cells

    OpenAIRE

    Cheng, Yuang-Tung; Ho, Jyh-Jier; Lee, William J.; Tsai, Song-Yeu; Lu, Yung-An; Liou, Jia-Jhe; Chang, Shun-Hsyung; Wang, Kang L.

    2010-01-01

    The subject of the present work is to develop a simple and effective method of enhancing conversion efficiency in large-size solar cells using multicrystalline silicon (mc-Si) wafer. In this work, industrial-type mc-Si solar cells with area of 125×125 mm2 were acid etched to produce simultaneously POCl3 emitters and silicon nitride deposition by plasma-enhanced chemical vapor deposited (PECVD). The study of surface morphology and reflectivity of different mc-Si etched surfaces has also been d...

  19. Heliosphere Responds to a Large Solar Wind Intensification: Decisive Observations from IBEX

    Science.gov (United States)

    McComas, D. J.; Dayeh, M. A.; Funsten, H. O.; Heerikhuisen, J.; Janzen, P. H.; Reisenfeld, D. B.; Schwadron, N. A.; Szalay, J. R.; Zirnstein, E. J.

    2018-03-01

    Our heliosphere—the bubble in the local interstellar medium produced by the Sun’s outflowing solar wind—has finally responded to a large increase in solar wind output and pressure in the second half of 2014. NASA’s Interstellar Boundary Explorer (IBEX) mission remotely monitors the outer heliosphere by observing energetic neutral atoms (ENAs) returning from the heliosheath, the region between the termination shock and heliopause. IBEX observed a significant enhancement in higher energy ENAs starting in late 2016. While IBEX observations over the previous decade reflected a general reduction of ENA intensities, indicative of a deflating heliosphere, new observations show that the large (∼50%), persistent increase in the solar wind dynamic pressure has modified the heliosheath, producing enhanced ENA emissions. The combination of these new observations with simulation results indicate that this pressure is re-expanding our heliosphere, with the termination shock and heliopause already driven outward in the locations closest to the Sun. The timing between the IBEX observations, a large transient pressure enhancement seen by Voyager 2, and the simulations indicates that the pressure increase propagated through the heliosheath, reflected off the heliopause, and the enhanced density of the solar wind filled the heliosheath behind it before generating significantly enhanced ENA emissions. The coming years should see significant changes in anomalous cosmic rays, galactic cosmic radiation, and the filtration of interstellar neutral atoms into the inner heliosphere.

  20. The Long-term Middle Atmospheric Influence of Very Large Solar Proton Events

    Science.gov (United States)

    Jackman, Charles H.; Marsh, Daniel R.; Vitt, Francis M.; Garcia, Rolando R.; Randall, Cora E.; Fleming, Eric L.; Frith, Stacey M.

    2008-01-01

    Long-term variations in ozone have been caused by both natural and humankind related processes. The humankind or anthropogenic influence on ozone originates from the chlorofluorocarbons and halons (chlorine and bromine) and has led to international regulations greatly limiting the release of these substances. Certain natural ozone influences are also important in polar regions and are caused by the impact of solar charged particles on the atmosphere. Such natural variations have been studied in order to better quantify the human influence on polar ozone. Large-scale explosions on the Sun near solar maximum lead to emissions of charged particles (mainly protons and electrons), some of which enter the Earth's magnetosphere and rain down on the polar regions. "Solar proton events" have been used to describe these phenomena since the protons associated with these solar events sometimes create a significant atmospheric disturbance. We have used the National Center for Atmospheric Research (NCAR) Whole Atmosphere Community Climate Model (WACCM) to study the long-term (> few months) influences of solar proton events from 1963 through 2004 on stratospheric ozone and temperature. There were extremely large solar proton events in 1972, 1989,2000,2001, and 2003. These events caused very distinctive polar changes in layers of the Earth's atmosphere known as the stratosphere (12-50 km; -7-30 miles) and mesosphere (50-90 km; 30-55 miles). The solar protons connected with these events created hydrogen- and nitrogen-containing compounds, which led to the polar ozone destruction. The nitrogen-containing compounds, called odd nitrogen, lasted much longer than the hydrogen-containing compounds and led to long-lived stratospheric impacts. An extremely active period for these events occurred in the five-year period, 2000- 2004, and caused increases in odd nitrogen which lasted for several months after individual events. Associated stratospheric ozone decreases of >lo% were calculated

  1. A Large-scale Plume in an X-class Solar Flare

    Energy Technology Data Exchange (ETDEWEB)

    Fleishman, Gregory D.; Nita, Gelu M.; Gary, Dale E. [Physics Department, Center for Solar-Terrestrial Research, New Jersey Institute of Technology Newark, NJ, 07102-1982 (United States)

    2017-08-20

    Ever-increasing multi-frequency imaging of solar observations suggests that solar flares often involve more than one magnetic fluxtube. Some of the fluxtubes are closed, while others can contain open fields. The relative proportion of nonthermal electrons among those distinct loops is highly important for understanding energy release, particle acceleration, and transport. The access of nonthermal electrons to the open field is also important because the open field facilitates the solar energetic particle (SEP) escape from the flaring site, and thus controls the SEP fluxes in the solar system, both directly and as seed particles for further acceleration. The large-scale fluxtubes are often filled with a tenuous plasma, which is difficult to detect in either EUV or X-ray wavelengths; however, they can dominate at low radio frequencies, where a modest component of nonthermal electrons can render the source optically thick and, thus, bright enough to be observed. Here we report the detection of a large-scale “plume” at the impulsive phase of an X-class solar flare, SOL2001-08-25T16:23, using multi-frequency radio data from Owens Valley Solar Array. To quantify the flare’s spatial structure, we employ 3D modeling utilizing force-free-field extrapolations from the line of sight SOHO /MDI magnetograms with our modeling tool GX-Simulator. We found that a significant fraction of the nonthermal electrons that accelerated at the flare site low in the corona escapes to the plume, which contains both closed and open fields. We propose that the proportion between the closed and open fields at the plume is what determines the SEP population escaping into interplanetary space.

  2. INTERACTION BETWEEN TWO CORONAL MASS EJECTIONS IN THE 2013 MAY 22 LARGE SOLAR ENERGETIC PARTICLE EVENT

    International Nuclear Information System (INIS)

    Ding, Liu-Guan; Xu, Fei; Gu, Bin; Zhang, Ya-Nan; Li, Gang; Jiang, Yong; Le, Gui-Ming; Shen, Cheng-Long; Wang, Yu-Ming; Chen, Yao

    2014-01-01

    We investigate the eruption and interaction of two coronal mass ejections (CMEs) during the large 2013 May 22 solar energetic particle event using multiple spacecraft observations. Two CMEs, having similar propagation directions, were found to erupt from two nearby active regions (ARs), AR11748 and AR11745, at ∼08:48 UT and ∼13:25 UT, respectively. The second CME was faster than the first CME. Using the graduated cylindrical shell model, we reconstructed the propagation of these two CMEs and found that the leading edge of the second CME caught up with the trailing edge of the first CME at a height of ∼6 solar radii. After about two hours, the leading edges of the two CMEs merged at a height of ∼20 solar radii. Type II solar radio bursts showed strong enhancement during this two hour period. Using the velocity dispersion method, we obtained the solar particle release (SPR) time and the path length for energetic electrons. Further assuming that energetic protons propagated along the same interplanetary magnetic field, we also obtained the SPR time for energetic protons, which were close to that of electrons. These release times agreed with the time when the second CME caught up with the trailing edge of the first CME, indicating that the CME-CME interaction (and shock-CME interaction) plays an important role in the process of particle acceleration in this event

  3. A large-scale dataset of solar event reports from automated feature recognition modules

    Science.gov (United States)

    Schuh, Michael A.; Angryk, Rafal A.; Martens, Petrus C.

    2016-05-01

    The massive repository of images of the Sun captured by the Solar Dynamics Observatory (SDO) mission has ushered in the era of Big Data for Solar Physics. In this work, we investigate the entire public collection of events reported to the Heliophysics Event Knowledgebase (HEK) from automated solar feature recognition modules operated by the SDO Feature Finding Team (FFT). With the SDO mission recently surpassing five years of operations, and over 280,000 event reports for seven types of solar phenomena, we present the broadest and most comprehensive large-scale dataset of the SDO FFT modules to date. We also present numerous statistics on these modules, providing valuable contextual information for better understanding and validating of the individual event reports and the entire dataset as a whole. After extensive data cleaning through exploratory data analysis, we highlight several opportunities for knowledge discovery from data (KDD). Through these important prerequisite analyses presented here, the results of KDD from Solar Big Data will be overall more reliable and better understood. As the SDO mission remains operational over the coming years, these datasets will continue to grow in size and value. Future versions of this dataset will be analyzed in the general framework established in this work and maintained publicly online for easy access by the community.

  4. Concentrated Solar Power as part of the European energy supply. The realization of large-scale solar power plants. Options, constraints and recommendations

    International Nuclear Information System (INIS)

    Bouwmans, I.; Carton, L.J.; Dijkema, G.P.J.; Stikkelman, R.M.; De Vries, L.J.

    2006-01-01

    Next to solar cells and solar collectors for decentralized power generation Concentrated Solar Power (CSP) technology is available and proven for large-scale application of solar energy. However, after 20 years of demonstration projects and semi-commercial installations, CSP is still not widely used. In this quick-scan an overview is given of strong and weak points of CSP, as well as its' options and constraints with regard to a sustainable energy supply, focusing on technical, economical and administrative constraints and chances in Europe and European Union member states [nl

  5. Organic solar cell modules for specific applications-From energy autonomous systems to large area photovoltaics

    International Nuclear Information System (INIS)

    Niggemann, M.; Zimmermann, B.; Haschke, J.; Glatthaar, M.; Gombert, A.

    2008-01-01

    We report on the development of two types of organic solar cell modules one for energy autonomous systems and one for large area energy harvesting. The first requires a specific tailoring of the solar cell geometry and cell interconnection in order to power an energy autonomous system under its specific operating conditions. We present an organic solar cell module with 22 interconnected solar cells. A power conversion efficiency of 2% under solar illumination has been reached on the active area of 46.2 cm 2 . A voltage of 4 V at the maximum power point has been obtained under indoor illumination conditions. Micro contact printing of a self assembling monolayer was employed for the patterning of the polymer anode. Large area photovoltaic modules have to meet the requirements on efficiency, lifetime and costs simultaneously. To minimize the production costs, a suitable concept for efficient reel-to-reel production of large area modules is needed. A major contribution to reduce the costs is the substitution of the commonly used indium tin oxide electrode by a cheap material. We present the state of the art of the anode wrap through concept as a reel-to-reel suited module concept and show comparative calculations of the module interconnection of the wrap through concept and the standard ITO-based cell architecture. As a result, the calculated overall module efficiency of the anode wrap through module exceeds the overall efficiency of modules based on ITO on glass (sheet resistance 15 Ω/square) and on foils (sheet resistance 60 Ω/square)

  6. Research progress on large-area perovskite thin films and solar modules

    Directory of Open Access Journals (Sweden)

    Zhichun Yang

    2017-12-01

    Full Text Available Organometal halide perovskites have exhibited a bright future as photovoltaic semiconductor in next generation solar cells due to their unique and promising physicochemical properties. Over the past few years, we have witnessed a tremendous progress of efficiency record evolution of perovskite solar cells (PSCs. Up to now, the highest efficiency record of PSCs has reached 22.1%; however, it was achieved at a very small device area of <0.1 cm2. With the device area increasing to mini-module scale, the efficiency record dropped dramatically. The inherent causes are mainly ascribed to inadequate quality control of large-area perovskite thin films and insufficient optimization of solar module design. In current stage of PSCs research and development, to overcome these two obstacles is in urgent need before this new technology could realize scale-up industrialization. Herein, we present an overview of recently developed strategies for preparing large-area perovskite thin films and perovskite solar modules (PSMs. At last, cost analysis and future application directions of PSMs have also been discussed.

  7. Two Exceptions in the Large SEP Events of Solar Cycles 23 and 24

    Science.gov (United States)

    Thakur, N.; Gopalswamy, N.; Makela, P.; Akiyama, S.; Yashiro, S.; Xie, H.

    2016-01-01

    We discuss our findings from a survey of all large solar energetic particle (SEP) events of Solar Cycles 23 and 24, i.e. the SEP events where the intensity of greater than 10 megaelectronvolts protons observed by GOES (Geostationary Operational Environmental Satellite) was greater than 10 proton flux units. In our previous work (Gopalswamy et al. in Geophys.Res.Lett. 41, 2673, 2014) we suggested that ground level enhancements (GLEs) in Cycles 23 and 24 also produce an intensity increase in the GOES greater than 700 megaelectronvolts proton channel. Our survey, now extended to include all large SEP events of Cycle 23, confirms this to be true for all but two events: i) the GLE of 6 May 1998 (GLE57) for which GOES did not observe enhancement in greater than 700 megaelectronvolts protons intensities and ii) a high-energy SEP event of 8 November 2000, for which GOES observed greater than 700 megaelectronvolts protons but no GLE was recorded. Here we discuss these two exceptions. We compare GLE57 with other small GLEs, and the 8 November 2000 SEP event with those that showed similar intensity increases in the GOES greater than 700 megaelectronvolts protons but produced GLEs. We find that, because GOES greater than 700 megaelectronvolts proton intensity enhancements are typically small for small GLEs, they are difficult to discern near solar minima due to higher background. Our results also support that GLEs are generally observed when shocks of the associated coronal mass ejections (CMEs) form at heights 1.2-1.93 solar radii [R (sub solar)] and when the solar particle release occurs between 2-6 solar radii [R (sub solar)]. Our secondary findings support the view that the nose region of the CME-shock may be accelerating the first-arriving GLE particles and the observation of a GLE is also dependent on the latitudinal connectivity of the observer to the CME-shock nose. We conclude that the GOES greater than 700 megaelectronvolts proton channel can be used as an indicator

  8. Large-Scale Fabrication of Silicon Nanowires for Solar Energy Applications.

    Science.gov (United States)

    Zhang, Bingchang; Jie, Jiansheng; Zhang, Xiujuan; Ou, Xuemei; Zhang, Xiaohong

    2017-10-11

    The development of silicon (Si) materials during past decades has boosted up the prosperity of the modern semiconductor industry. In comparison with the bulk-Si materials, Si nanowires (SiNWs) possess superior structural, optical, and electrical properties and have attracted increasing attention in solar energy applications. To achieve the practical applications of SiNWs, both large-scale synthesis of SiNWs at low cost and rational design of energy conversion devices with high efficiency are the prerequisite. This review focuses on the recent progresses in large-scale production of SiNWs, as well as the construction of high-efficiency SiNW-based solar energy conversion devices, including photovoltaic devices and photo-electrochemical cells. Finally, the outlook and challenges in this emerging field are presented.

  9. Temperature Distribution and Influence Mechanism on Large Reflector Antennas under Solar Radiation

    Science.gov (United States)

    Wang, C. S.; Yuan, S.; Liu, X.; Xu, Q.; Wang, M.; Zhu, M. B.; Chen, G. D.; Duan, Y. H.

    2017-10-01

    The solar impact on antenna must be lessened for the large reflector antenna operating at high frequencies to have great electromagnetic performances. Therefore, researching the temperature distribution and its influence on large reflector antenna is necessary. The variation of solar incidence angle is first calculated. Then the model is simulated by the I-DEAS software, with the temperature, thermal stress, and thermal distortion distribution through the day obtained. In view of the important influence of shadow on antenna structure, a newly proposed method makes a comprehensive description of the temperature distribution on the reflector and its influence through the day by dividing a day into three different periods. The sound discussions and beneficial summary serve as the scientific foundation for the engineers to compensate the thermal distortion and optimize the antenna structure.

  10. Origin of the high performance of perovskite solar cells with large grains

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Jian; Shi, Tongfei, E-mail: tongfeishi@gmail.com; Li, Xinhua; Zhou, Bukang; Cao, Huaxiang; Wang, Yuqi [Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, Hefei 230031 (China)

    2016-02-01

    Due to excellent carrier transport characteristics, CH{sub 3}NH{sub 3}PbI{sub 3} film made of large single crystal grains is considered as a key to improve upon already remarkable perovskite solar cell (PSC) efficiency. We have used a simple and efficient solvent vapor annealing method to obtain CH{sub 3}NH{sub 3}PbI{sub 3} films with grain size over 1 μm. PSCs with different grain size films have been fabricated and verified the potential of large grains for improving solar cells performance. Moreover, the larger grain films have shown stronger light absorption ability and more photon-generated carriers under the same illumination. A detailed temperature-dependent PL study has indicated that it originates from larger radius and lower binding energy of donor-acceptor-pair (DAP) in larger grains, which makes the DAP is easily to be separated and difficult to be recombine.

  11. Dynamics of the Solar Wind Electromagnetic Energy Transmission Into Magnetosphere during Large Geomagnetic Storms

    Science.gov (United States)

    Kuznetsova, Tamara; Laptukhov, Alexej; Petrov, Valery

    Causes of the geomagnetic activity (GA) in the report are divided into temporal changes of the solar wind parameters and the changes of the geomagnetic moment orientation relative directions of the solar wind electric and magnetic fields. Based on our previous study we concluded that a reconnection based on determining role of mutual orientation of the solar wind electric field and geomagnetic moment taking into account effects of the Earth's orbital and daily motions is the most effective compared with existing mechanisms. At present a reconnection as paradigma that has applications in broad fields of physics needs analysis of experimental facts to be developed. In terms of reconnection it is important not only mutual orientation of vectors describing physics of interaction region but and reconnection rate which depends from rate of energy flux to those regions where the reconnection is permitted. Applied to magnetosphere these regions first of all are dayside magnetopause and polar caps. Influence of rate of the energy flux to the lobe magnetopause (based on calculations of the Poyting electromagnetic flux component controlling the reconnection rate along the solar wind velocity Pv) on planetary GA (Dst, Kp indices) is investigated at different phases of geomagnetic storms. We study also the rate of energy flux to the polar caps during storms (based on calculations of the Poyting flux vector component along the geomagnetic moment Pm) and its influence on magnetic activity in the polar ionosphere: at the auroral zone (AU,AL indices). Results allow to evaluate contributions of high and low latitude sources of electromagnetic energy to the storm development and also to clear mechanism of the electromagnetic energy transmission from the solar wind to the magnetosphere. We evaluate too power of the solar wind electromagnetic energy during well-known large storms and compare result with power of the energy sources of other geophysical processes (atmosphere, ocean

  12. A DATA-DRIVEN ANALYTIC MODEL FOR PROTON ACCELERATION BY LARGE-SCALE SOLAR CORONAL SHOCKS

    Energy Technology Data Exchange (ETDEWEB)

    Kozarev, Kamen A. [Smithsonian Astrophysical Observatory (United States); Schwadron, Nathan A. [Institute for the Study of Earth, Oceans, and Space, University of New Hampshire (United States)

    2016-11-10

    We have recently studied the development of an eruptive filament-driven, large-scale off-limb coronal bright front (OCBF) in the low solar corona, using remote observations from the Solar Dynamics Observatory ’s Advanced Imaging Assembly EUV telescopes. In that study, we obtained high-temporal resolution estimates of the OCBF parameters regulating the efficiency of charged particle acceleration within the theoretical framework of diffusive shock acceleration (DSA). These parameters include the time-dependent front size, speed, and strength, as well as the upstream coronal magnetic field orientations with respect to the front’s surface normal direction. Here we present an analytical particle acceleration model, specifically developed to incorporate the coronal shock/compressive front properties described above, derived from remote observations. We verify the model’s performance through a grid of idealized case runs using input parameters typical for large-scale coronal shocks, and demonstrate that the results approach the expected DSA steady-state behavior. We then apply the model to the event of 2011 May 11 using the OCBF time-dependent parameters derived by Kozarev et al. We find that the compressive front likely produced energetic particles as low as 1.3 solar radii in the corona. Comparing the modeled and observed fluences near Earth, we also find that the bulk of the acceleration during this event must have occurred above 1.5 solar radii. With this study we have taken a first step in using direct observations of shocks and compressions in the innermost corona to predict the onsets and intensities of solar energetic particle events.

  13. Environmental Impacts From the Installation and Operation of Large-scale Solar Power Plants

    Energy Technology Data Exchange (ETDEWEB)

    Fthenakis, V.; Turney, Damon

    2011-04-23

    Large-scale solar power plants are being developed at a rapid rate, and are setting up to use thousands or millions of acres of land globally. The environmental issues related to the installation and operation phases of such facilities have not, so far, been addressed comprehensively in the literature. Here we identify and appraise 32 impacts from these phases, under the themes of land use intensity, human health and well-being, plant and animal life, geohydrological resources, and climate change. Our appraisals assume that electricity generated by new solar power facilities will displace electricity from traditional U.S. generation technologies. Altogether we find 22 of the considered 32 impacts to be beneficial. Of the remaining 10 impacts, 4 are neutral, and 6 require further research before they can be appraised. None of the impacts are negative relative to traditional power generation. We rank the impacts in terms of priority, and find all the high-priority impacts to be beneficial. In quantitative terms, large-scale solar power plants occupy the same or less land per kW h than coal power plant life cycles. Removal of forests to make space for solar power causes CO{sub 2} emissions as high as 36 g CO{sub 2} kW h{sup -1}, which is a significant contribution to the life cycle CO{sub 2} emissions of solar power, but is still low compared to CO{sub 2} emissions from coal-based electricity that are about 1100 g CO{sub 2} kW h{sup -1}.

  14. ASSOCIATION OF {sup 3}He-RICH SOLAR ENERGETIC PARTICLES WITH LARGE-SCALE CORONAL WAVES

    Energy Technology Data Exchange (ETDEWEB)

    Bučík, Radoslav [Institut für Astrophysik, Georg-August-Universität Göttingen, D-37077, Göttingen (Germany); Innes, Davina E. [Max-Planck-Institut für Sonnensystemforschung, D-37077, Göttingen (Germany); Mason, Glenn M. [Applied Physics Laboratory, Johns Hopkins University, Laurel, MD 20723 (United States); Wiedenbeck, Mark E., E-mail: bucik@mps.mpg.de [Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 (United States)

    2016-12-10

    Small, {sup 3}He-rich solar energetic particle (SEP) events have been commonly associated with extreme-ultraviolet (EUV) jets and narrow coronal mass ejections (CMEs) that are believed to be the signatures of magnetic reconnection, involving field lines open to interplanetary space. The elemental and isotopic fractionation in these events are thought to be caused by processes confined to the flare sites. In this study, we identify 32 {sup 3}He-rich SEP events observed by the Advanced Composition Explorer , near the Earth, during the solar minimum period 2007–2010, and we examine their solar sources with the high resolution Solar Terrestrial Relations Observatory ( STEREO ) EUV images. Leading the Earth, STEREO -A has provided, for the first time, a direct view on {sup 3}He-rich flares, which are generally located on the Sun’s western hemisphere. Surprisingly, we find that about half of the {sup 3}He-rich SEP events in this survey are associated with large-scale EUV coronal waves. An examination of the wave front propagation, the source-flare distribution, and the coronal magnetic field connections suggests that the EUV waves may affect the injection of {sup 3}He-rich SEPs into interplanetary space.

  15. Association of 3He-rich solar energetic particles with large-scale coronal waves

    Science.gov (United States)

    Bucik, Radoslav; Innes, Davina; Guo, Lijia; Mason, Glenn M.; Wiedenbeck, Mark

    2016-07-01

    Impulsive or 3He-rich solar energetic particle (SEP) events have been typically associated with jets or small EUV brightenings. We identify 30 impulsive SEP events from ACE at L1 during the solar minimum period 2007-2010 and examine their solar sources with high resolution STEREO-A EUV images. At beginning of 2007, STEREO-A was near the Earth while at the end of the investigated period, when there were more events, STEREO-A was leading the Earth by 90°. Thus STEREO-A provided a better (more direct) view on 3He-rich flares generally located on the western Sun's hemisphere. Surprisingly, we find that about half of the events are associated with large-scale EUV coronal waves. This finding provides new insights on acceleration and transport of 3He-rich SEPs in solar corona. It is believed that elemental and isotopic fractionation in impulsive SEP events is caused by more localized processes operating in the flare sites. The EUV waves have been reported in gradual SEP events in association with fast coronal mass ejections. To examine their role on 3He-rich SEPs production the energy spectra and relative abundances are discussed. R. Bucik is supported by the Deutsche Forschungsgemeinschaft under grant BU 3115/2-1.

  16. Investigation of Low-Cost Surface Processing Techniques for Large-Size Multicrystalline Silicon Solar Cells

    Directory of Open Access Journals (Sweden)

    Yuang-Tung Cheng

    2010-01-01

    Full Text Available The subject of the present work is to develop a simple and effective method of enhancing conversion efficiency in large-size solar cells using multicrystalline silicon (mc-Si wafer. In this work, industrial-type mc-Si solar cells with area of 125×125 mm2 were acid etched to produce simultaneously POCl3 emitters and silicon nitride deposition by plasma-enhanced chemical vapor deposited (PECVD. The study of surface morphology and reflectivity of different mc-Si etched surfaces has also been discussed in this research. Using our optimal acid etching solution ratio, we are able to fabricate mc-Si solar cells of 16.34% conversion efficiency with double layers silicon nitride (Si3N4 coating. From our experiment, we find that depositing double layers silicon nitride coating on mc-Si solar cells can get the optimal performance parameters. Open circuit (Voc is 616 mV, short circuit current (Jsc is 34.1 mA/cm2, and minority carrier diffusion length is 474.16 μm. The isotropic texturing and silicon nitride layers coating approach contribute to lowering cost and achieving high efficiency in mass production.

  17. Solar neutrino detection in a large volume double-phase liquid argon experiment

    Energy Technology Data Exchange (ETDEWEB)

    Franco, D.; Agnes, P. [APC, Université Paris Diderot, CNRS/IN2P3, CEA/Irfu, Observatoire de Paris, Sorbonne Paris Cité, Paris 75205 (France); Giganti, C.; Agostino, L.; De Cecco, S., E-mail: dfranco@in2p3.fr, E-mail: cgiganti@lpnhe.in2p3.fr, E-mail: pagnes@in2p3.fr, E-mail: lagostin@lpnhe.in2p3.fr, E-mail: sandro.dececco@lpnhe.in2p3.fr [LPNHE Paris, Université Pierre et Marie Curie, Université Paris Diderot, CNRS/IN2P3, Paris 75252 (France); and others

    2016-08-01

    Precision measurements of solar neutrinos emitted by specific nuclear reaction chains in the Sun are of great interest for developing an improved understanding of star formation and evolution. Given the expected neutrino fluxes and known detection reactions, such measurements require detectors capable of collecting neutrino-electron scattering data in exposures on the order of 1 ktonne-yr, with good energy resolution and extremely low background. Two-phase liquid argon time projection chambers (LAr TPCs) are under development for direct Dark Matter WIMP searches, which possess very large sensitive mass, high scintillation light yield, good energy resolution, and good spatial resolution in all three cartesian directions. While enabling Dark Matter searches with sensitivity extending to the ''neutrino floor'' (given by the rate of nuclear recoil events from solar neutrino coherent scattering), such detectors could also enable precision measurements of solar neutrino fluxes using the neutrino-electron elastic scattering events. Modeling results are presented for the cosmogenic and radiogenic backgrounds affecting solar neutrino detection in a 300 tonne (100 tonne fiducial) LAr TPC operating at LNGS depth (3,800 meters of water equivalent). The results show that such a detector could measure the CNO neutrino rate with ∼15% precision, and significantly improve the precision of the {sup 7}Be and pep neutrino rates compared to the currently available results from the Borexino organic liquid scintillator detector.

  18. Composition variations of low energy heavy ions during large solar energetic particle events

    Energy Technology Data Exchange (ETDEWEB)

    Ho, George C., E-mail: George.Ho@jhuapl.edu; Mason, Glenn M., E-mail: Glenn.Mason@jhuapl.edu [Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723 (United States)

    2016-03-25

    The time-intensity profile of large solar energetic particle (SEP) event is well organized by solar longitude as observed at Earth orbit. This is mostly due to different magnetic connection to the shock that is associated with large SEP event propagates from the Sun to the heliosphere. Earlier studies have shown event averaged heavy ion abundance ratios can also vary as a function of solar longitude. It was found that the Fe/O ratio for high energy particle (>10 MeV/nucleon) is higher for those western magnetically well connected events compare to the eastern events as observed at L1 by the Advanced Composition Explorer (ACE) spacecraft. In this paper, we examined the low energy (∼1 MeV/nucleon) heavy ions in 110 isolated SEP events from 2009 to the end of 2014. In addition, the optical and radio signatures for all of our events are identified and when data are available we also located the associated coronal mass ejection (CME) data. Our survey shows a higher Fe/O ratio at events in the well-connected region, while there are no corrections between the event averaged elemental composition with the associated coronal mass ejection speed. This is inconsistent with the higher energy results, but inline with other recent low-energy measurements.

  19. Solar total energy: large scale experiment, Shenandoah, Georgia Site. Annual report, June 1978-June 1979

    Energy Technology Data Exchange (ETDEWEB)

    Ney, E.J.

    1979-07-01

    A background summary and a complete description of the progress and current status of activities relative to the Cooperative Agreement for the Solar Total Energy - Large Scale Experiment at the Bleyle Knitwear Plant at Shenandoah, Georgia are presented. A statement of objectives and an abstract of progress to date are included. This is followed by a short introduction containing a project overview, a summary of the participants and their respective roles, a brief description of the Solar Total Energy System (STES) design concept, and a chronological summary of progress to date. A general description of the site is given, a detailed report of progress is reported, and drawings and equipment lists are included. The closed-loop solar energy system planned for Shenandoah begins with circulation of Syltherm 800, a heat transfer fluid of the Dow-Corning Corporation, through the receiver tubes of a parabolic dish solar collector field. As solar energy is focused on the receivers, the heat transfer fluid is heated to approximately 399/sup 0/C (750/sup 0/F) and is pumped to a heat exchanger for immediate use, or to a thermal storage system for later use. Once in the heat exchanger, the fluid heats a working fluid that produces the steam required for operating the turbine. After performing this task, the heat transfer fluid returns to the collectors to repeat the cycle, while the steam turbine-generator system supplies the electrical demands for the knitwear plant and the STES. During STES operation, maximum thermal and electrical requirements of the application are expected to be at 1.08 MWth and 161 kWe, respectively. During the power generation phase, some of the steam is extracted for use as process steam in the knitwear manufacturing process, while exhaust steam from the turbine is passed through a condenser to produce hot water for heating, domestic use, and absorption air conditioning. (WHK)

  20. A LARGE-SCALE SEARCH FOR EVIDENCE OF QUASI-PERIODIC PULSATIONS IN SOLAR FLARES

    Energy Technology Data Exchange (ETDEWEB)

    Inglis, A. R.; Ireland, J.; Dennis, B. R. [Solar Physics Laboratory, Heliophysics Science Division, NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Hayes, L; Gallagher, P. [Trinity College Dublin, Dublin (Ireland)

    2016-12-20

    The nature of quasi-periodic pulsations (QPP) in solar flares is poorly constrained, and critically the general prevalence of such signals in solar flares is unknown. Therefore, we perform a large-scale search for evidence of signals consistent with QPP in solar flares, focusing on the 1–300 s timescale. We analyze 675 M- and X-class flares observed by the Geostationary Operational Environmental Satellite (GOES) series in 1–8 Å soft X-rays between 2011 February 1 and 2015 December 31. Additionally, over the same era we analyze Fermi /Gamma-ray Burst Monitor (GBM) 15–25 keV X-ray data for each of these flares associated with a Fermi /GBM solar flare trigger, a total of 261 events. Using a model comparison method, we determine whether there is evidence for a substantial enhancement in the Fourier power spectrum that may be consistent with a QPP signature, based on three tested models; a power-law plus a constant, a broken power-law plus constant, and a power-law-plus-constant with an additional QPP signature component. From this, we determine that ∼30% of GOES events and ∼8% of Fermi /GBM events show strong signatures consistent with classical interpretations of QPP. For the remaining events either two or more tested models cannot be strongly distinguished from each other, or the events are well-described by single power-law or broken power-law Fourier power spectra. For both instruments, a preferred characteristic timescale of ∼5–30 s was found in the QPP-like events, with no dependence on flare magnitude in either GOES or GBM data. We also show that individual events in the sample show similar characteristic timescales in both GBM and GOES data sets. We discuss the implications of these results for our understanding of solar flares and possible QPP mechanisms.

  1. A Large-Scale Search for Evidence of Quasi-Periodic Pulsations in Solar Flares

    Science.gov (United States)

    Inglis, A. R.; Ireland, J.; Dennis, B. R..; Hayes, L.; Gallagher, P.

    2016-01-01

    The nature of quasi-periodic pulsations (QPP) in solar flares is poorly constrained, and critically the general prevalence of such signals in solar flares is unknown. Therefore, we perform a large-scale search for evidence of signals consistent with QPP in solar flares, focusing on the 1300 s timescale. We analyze 675 M- and X-class flares observed by the Geostationary Operational Environmental Satellite (GOES) series in 18 soft X-rays between 2011 February 1 and 2015 December 31. Additionally, over the same era we analyze Fermi/Gamma-ray Burst Monitor (GBM) 1525 keV X-ray data for each of these flares associated with a Fermi/GBM solar flare trigger, a total of 261 events. Using a model comparison method, we determine whether there is evidence for a substantial enhancement in the Fourier power spectrum that may be consistent with a QPP signature, based on three tested models; a power-law plus a constant, a broken power-law plus constant, and a power-law-plus-constant with an additional QPP signature component. From this, we determine that approx. 30% of GOES events and approx. 8% of Fermi/GBM events show strong signatures consistent with classical interpretations of QPP. For the remaining events either two or more tested models cannot be strongly distinguished from each other, or the events are well-described by single power-law or broken power-law Fourier power spectra. For both instruments, a preferred characteristic time-scale of approx. 5-30 s was found in the QPP-like events, with no dependence on flare magnitude in either GOES or GBM data. We also show that individual events in the sample show similar characteristic time-scales in both GBM and GOES data sets. We discuss the implications of these results for our understanding of solar flares and possible QPP mechanisms.

  2. A LARGE-SCALE SEARCH FOR EVIDENCE OF QUASI-PERIODIC PULSATIONS IN SOLAR FLARES

    International Nuclear Information System (INIS)

    Inglis, A. R.; Ireland, J.; Dennis, B. R.; Hayes, L; Gallagher, P.

    2016-01-01

    The nature of quasi-periodic pulsations (QPP) in solar flares is poorly constrained, and critically the general prevalence of such signals in solar flares is unknown. Therefore, we perform a large-scale search for evidence of signals consistent with QPP in solar flares, focusing on the 1–300 s timescale. We analyze 675 M- and X-class flares observed by the Geostationary Operational Environmental Satellite (GOES) series in 1–8 Å soft X-rays between 2011 February 1 and 2015 December 31. Additionally, over the same era we analyze Fermi /Gamma-ray Burst Monitor (GBM) 15–25 keV X-ray data for each of these flares associated with a Fermi /GBM solar flare trigger, a total of 261 events. Using a model comparison method, we determine whether there is evidence for a substantial enhancement in the Fourier power spectrum that may be consistent with a QPP signature, based on three tested models; a power-law plus a constant, a broken power-law plus constant, and a power-law-plus-constant with an additional QPP signature component. From this, we determine that ∼30% of GOES events and ∼8% of Fermi /GBM events show strong signatures consistent with classical interpretations of QPP. For the remaining events either two or more tested models cannot be strongly distinguished from each other, or the events are well-described by single power-law or broken power-law Fourier power spectra. For both instruments, a preferred characteristic timescale of ∼5–30 s was found in the QPP-like events, with no dependence on flare magnitude in either GOES or GBM data. We also show that individual events in the sample show similar characteristic timescales in both GBM and GOES data sets. We discuss the implications of these results for our understanding of solar flares and possible QPP mechanisms.

  3. ({The) Solar System Large Planets influence on a new Maunder Miniμm}

    Science.gov (United States)

    Yndestad, Harald; Solheim, Jan-Erik

    2016-04-01

    In 1890´s G. Spörer and E. W. Maunder (1890) reported that the solar activity stopped in a period of 70 years from 1645 to 1715. Later a reconstruction of the solar activity confirms the grand minima Maunder (1640-1720), Spörer (1390-1550), Wolf (1270-1340), and the minima Oort (1010-1070) and Dalton (1785-1810) since the year 1000 A.D. (Usoskin et al. 2007). These minimum periods have been associated with less irradiation from the Sun and cold climate periods on Earth. An identification of a three grand Maunder type periods and two Dalton type periods in a period thousand years, indicates that sooner or later there will be a colder climate on Earth from a new Maunder- or Dalton- type period. The cause of these minimum periods, are not well understood. An expected new Maunder-type period is based on the properties of solar variability. If the solar variability has a deterministic element, we can estimate better a new Maunder grand minimum. A random solar variability can only explain the past. This investigation is based on the simple idea that if the solar variability has a deterministic property, it must have a deterministic source, as a first cause. If this deterministic source is known, we can compute better estimates the next expected Maunder grand minimum period. The study is based on a TSI ACRIM data series from 1700, a TSI ACRIM data series from 1000 A.D., sunspot data series from 1611 and a Solar Barycenter orbit data series from 1000. The analysis method is based on a wavelet spectrum analysis, to identify stationary periods, coincidence periods and their phase relations. The result shows that the TSI variability and the sunspots variability have deterministic oscillations, controlled by the large planets Jupiter, Uranus and Neptune, as the first cause. A deterministic model of TSI variability and sunspot variability confirms the known minimum and grand minimum periods since 1000. From this deterministic model we may expect a new Maunder type sunspot

  4. Thermospheric response observed over Fritz peak, Colorado, during two large geomagnetic storms near solar cycle maximum

    International Nuclear Information System (INIS)

    Hernandez, G.; Roble, R.G.; Ridley, E.C.; Allen, J.H.

    1982-01-01

    Nightime thermospheric winds and temperatures have been measured over Fritz Peak Observatory, Colorado (39.9 0 N, 105.5 0 W), with a high resolution Fabry-Perot spectrometer. The winds and temperatures are obtained from the Doppler shifts and line profiles of the (O 1) 15,867K (630 nm) line emission. Measurements made during two large geomagnetic storm periods near solar cycle maximum reveal a thermospheric response to the heat and momentum sources associated with these storms that is more complex than the ones measured near solar cycle minimum. In the earlier measurements made during solar cycle minimum, the winds to the north of Fritz Peak Observatory had an enhanced equatorward component and the winds to the south were also equatorward, usually with smaller velocities. The winds measured to the east and west of the observatory both had an enhanced westward wind component. For the two large storms near the present solar cycle maximum period converging winds are observed in each of the cardinal directions from Fritz Peak Observatory. These converging winds with speeds of hundreds of meters per second last for several hours. The measured neutral gas temperature in each of the directions also increases several hundred degrees Kelvin. Numerical experiments done with the NCAR thermospheric general circulation model (TGCM) suggest that the winds to the east and north of the station are driven by high-latitude heating and enhanced westward ion drag associated with magnetospheric convection. The cause of the enhanced poleward and eastward winds measured to the south and west of Fritz Peak Observatory, respectively, is not known. During geomagnetic quiet conditions the circulation is typically from the soutwest toward the northeast in the evening hours

  5. LARGE-SCALE MAGNETIC HELICITY FLUXES ESTIMATED FROM MDI MAGNETIC SYNOPTIC CHARTS OVER THE SOLAR CYCLE 23

    International Nuclear Information System (INIS)

    Yang Shangbin; Zhang Hongqi

    2012-01-01

    To investigate the characteristics of large-scale and long-term evolution of magnetic helicity with solar cycles, we use the method of Local Correlation Tracking to estimate the magnetic helicity evolution over solar cycle 23 from 1996 to 2009 using 795 MDI magnetic synoptic charts. The main results are as follows: the hemispheric helicity rule still holds in general, i.e., the large-scale negative (positive) magnetic helicity dominates the northern (southern) hemisphere. However, the large-scale magnetic helicity fluxes show the same sign in both hemispheres around 2001 and 2005. The global, large-scale magnetic helicity flux over the solar disk changes from a negative value at the beginning of solar cycle 23 to a positive value at the end of the cycle, while the net accumulated magnetic helicity is negative in the period between 1996 and 2009.

  6. LARGE-SCALE MAGNETIC HELICITY FLUXES ESTIMATED FROM MDI MAGNETIC SYNOPTIC CHARTS OVER THE SOLAR CYCLE 23

    Energy Technology Data Exchange (ETDEWEB)

    Yang Shangbin; Zhang Hongqi, E-mail: yangshb@nao.cas.cn [Key Laboratory of Solar Activity, National Astronomical Observatories, Chinese Academy of Sciences, 100012 Beijing (China)

    2012-10-10

    To investigate the characteristics of large-scale and long-term evolution of magnetic helicity with solar cycles, we use the method of Local Correlation Tracking to estimate the magnetic helicity evolution over solar cycle 23 from 1996 to 2009 using 795 MDI magnetic synoptic charts. The main results are as follows: the hemispheric helicity rule still holds in general, i.e., the large-scale negative (positive) magnetic helicity dominates the northern (southern) hemisphere. However, the large-scale magnetic helicity fluxes show the same sign in both hemispheres around 2001 and 2005. The global, large-scale magnetic helicity flux over the solar disk changes from a negative value at the beginning of solar cycle 23 to a positive value at the end of the cycle, while the net accumulated magnetic helicity is negative in the period between 1996 and 2009.

  7. Enhancing Performance of Large-Area Organic Solar Cells with Thick Film via Ternary Strategy.

    Science.gov (United States)

    Zhang, Jianqi; Zhao, Yifan; Fang, Jin; Yuan, Liu; Xia, Benzheng; Wang, Guodong; Wang, Zaiyu; Zhang, Yajie; Ma, Wei; Yan, Wei; Su, Wenming; Wei, Zhixiang

    2017-06-01

    Large-scale fabrication of organic solar cells requires an active layer with high thickness tolerability and the use of environment-friendly solvents. Thick films with high-performance can be achieved via a ternary strategy studied herein. The ternary system consists of one polymer donor, one small molecule donor, and one fullerene acceptor. The small molecule enhances the crystallinity and face-on orientation of the active layer, leading to improved thickness tolerability compared with that of a polymer-fullerene binary system. An active layer with 270 nm thickness exhibits an average power conversion efficiency (PCE) of 10.78%, while the PCE is less than 8% with such thick film for binary system. Furthermore, large-area devices are successfully fabricated using polyethylene terephthalate (PET)/Silver gride or indium tin oxide (ITO)-based transparent flexible substrates. The product shows a high PCE of 8.28% with an area of 1.25 cm 2 for a single cell and 5.18% for a 20 cm 2 module. This study demonstrates that ternary organic solar cells exhibit great potential for large-scale fabrication and future applications. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. A New Lead Iodide Perovskite based on Large Organic Cation for Solar Cell Application.

    Science.gov (United States)

    Ma, Chunqing; Shen, Dong; Lo, Ming Fai; Lee, Chun-Sing

    2018-06-06

    Methylammonium (CH3NH3+) and formamidinium ((NH2)2CH+) based lead iodide perovskites are currently the two commonly used organic-inorganic lead iodide perovskites for solar cell application. Till now, there is still no alternative organic cations, which can produce perovskites with bandgaps spanning the visible spectrum (i.e. solar cell application. Here, a new perovskite using large propane-1,3-diammonium cation (n-Pr(NH3)22+) with a chemical structure of (n-Pr(NH3)2)0.5PbI3 is demonstrated. X-ray diffraction (XRD) result shows that the new perovskite exhibits a three-dimensional (3D), tetragonal phase. The bandgap of the new perovskite is ~ 1.6 eV, which is desirable for photovoltaic application. A (n-Pr(NH3)2)0.5PbI3 perovskite solar cell (PSC) yields a power conversion efficiency (PCE) of 5.1%. More importantly, this new perovskite is composed of larger hydrophobic cation that provides a better moisture resistance compared to CH3NH3PbI3 perovskite. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Instrument Design of the Large Aperture Solar UV Visible and IR Observing Telescope (SUVIT) for the SOLAR-C Mission

    Science.gov (United States)

    Suematsu, Y.; Katsukawa, Y.; Shimizu, T.; Ichimoto, K.; Takeyama, N.

    2012-12-01

    We present an instrumental design of one major solar observation payload planned for the SOLAR-C mission: the Solar Ultra-violet Visible and near IR observing Telescope (SUVIT). The SUVIT is designed to provide high-angular-resolution investigation of the lower solar atmosphere, from the photosphere to the uppermost chromosphere, with enhanced spectroscopic and spectro-polarimetric capability in wide wavelength regions from 280 nm (Mg II h&k lines) to 1100 nm (He I 1083 nm line) with 1.5 m class aperture and filtergraphic and spectrographic instruments.

  10. Changes in the relationship between solar radiation and sunshine duration in large cities of China

    International Nuclear Information System (INIS)

    Liu, Jiandong; Linderholm, Hans; Chen, Deliang; Zhou, Xiuji; Flerchinger, Gerald N.; Yu, Qiang; Du, Jun; Wu, Dingrong; Shen, Yanbo; Yang, Zhenbin

    2015-01-01

    Based on the linear relationship between solar radiation and sunshine duration, the Angstrom model is widely used to estimate solar radiation from routinely observed meteorological variables for energy exploitation. However, the relationship may have changed in quickly developing regions in the recent decades under global “dimming” and “brightening” context, with increasing aerosols due to industrial pollutions. Solar radiation stations under different climate conditions in six large cities in China are selected to test this hypothesis. Analysis of the related meteorological items shows that Guiyang has the lowest solar radiation with the average annual value of 10.5 MJm −2 d −1 , while Lhasa on the Tibetan Plateau has the highest of 20.1 MJm −2 d −1 . Both radiation and sunshine hours decreased from 1961 to 2010, but at different rates. A moving linear regression method is used to investigate the changes in the relationship between radiation and sunshine duration, the results indicate an abrupt change in the correlation coefficients in 1980–1990s, which can be attributed to the aerosol load resulting from air pollution caused by the industrial development in 1980s under China's Open Door Policy. The sky condition has been changing from clean to dirty, thus the relationship between solar radiation and duration changes in the 1980's and has recovered in the recent decades. This finding implies that it might not necessarily be right to use long data sets for model calibration. Further investigation confirms that the Angstrom model performs the best with higher NSE (nash-sutcliffe efficiency) of 0.914 and lower MAPE (mean absolute percentage error) and RMSE (root mean square error) values of 13.7 w/m 2 and 23.9 w/m 2 respectively, when calibrated with a 10-year data set. In contrast, the model performs worst when it is calibrated with a 40-year data set, with NSE, MAPE and RMSE values of 0.891, 15.1 w/m 2 and 25.3 w/m 2 , respectively

  11. Large-scale interaction of the solar wind with cometary plasma tails

    International Nuclear Information System (INIS)

    Niedner, M.B. Jr.

    1979-01-01

    The study of the behavior of plasma tails in the context of their interaction with the solar wind could have important implications for the structure of the interplanetary medium in three dimensions. Comet Kohoutek 1973f exhibited a broad range of plasma tail behavior. On 1974 January 20, the tail was in a highly disturbed condition. Comet Kohoutek was encountering the leading edge of a very strong high-speed stream at the time the plasma tail disturbance started to develop. Comparison of the observed tail geometry on January 20 with the theoretical position angles generated from the wind sock theory of plasma tails and the corotated satellite observations shows that the tail disturbance was probably caused by large gradients of the polar component of the solar-wind velocity. Within hours after the disturbance of January 20, the plasma tail of comet Kohoutek became disconnected from the cometary head, and was replaced by a new plasma tail. The comet was very near an interplanetary sector boundary at the time of disconnection. The disconnection event (DE) is suggested to have resulted from the magnetic reconnection of plasma tail field lines. A similar analysis of other DEs found in original plate material and in published photographs shows the most DEs occur near corotated sector boundaries. Thus, the sector boundary model is further supported, and the finding provides the only known method of probing sector structure to high latitudes. Sector boundaries can often extend to high latitudes in a nearly North-South orientation, and this property is not restricted to times away from solar minimum. Furthermore, the boundaries are inferred to be randomly tilted with respect to the polarity sequence across the boundary and to the magnetic signs of the solar poles

  12. LARGE SOLAR ENERGETIC PARTICLE EVENTS ASSOCIATED WITH FILAMENT ERUPTIONS OUTSIDE ACTIVE REGIONS

    Energy Technology Data Exchange (ETDEWEB)

    Gopalswamy, N.; Mäkelä, P.; Akiyama, S.; Yashiro, S.; Xie, H.; Thakur, N. [Solar Physics Laboratory, NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Kahler, S. W., E-mail: nat.gopalswamy@nasa.gov [Air Force Research Laboratory, Albuquerque, NM 87117 (United States)

    2015-06-10

    We report on four large filament eruptions (FEs) from solar cycles 23 and 24 that were associated with large solar energetic particle (SEP) events and interplanetary type II radio bursts. The post-eruption arcades corresponded mostly to C-class soft X-ray enhancements, but an M1.0 flare was associated with one event. However, the associated coronal mass ejections (CMEs) were fast (speeds ∼ 1000 km s{sup −1}) and appeared as halo CMEs in the coronagraph field of view. The interplanetary type II radio bursts occurred over a wide wavelength range, indicating the existence of strong shocks throughout the inner heliosphere. No metric type II bursts were present in three events, indicating that the shocks formed beyond 2–3 Rs. In one case, there was a metric type II burst with low starting frequency, indicating a shock formation height of ∼2 Rs. The FE-associated SEP events did have softer spectra (spectral index >4) in the 10–100 MeV range, but there were other low-intensity SEP events with spectral indices ≥4. Some of these events are likely FE-SEP events, but were not classified as such in the literature because they occurred close to active regions. Some were definitely associated with large active region flares, but the shock formation height was large. We definitely find a diminished role for flares and complex type III burst durations in these large SEP events. Fast CMEs and shock formation at larger distances from the Sun seem to be the primary characteristics of the FE-associated SEP events.

  13. Large-Grain Tin-Rich Perovskite Films for Efficient Solar Cells via Metal Alloying Technique.

    Science.gov (United States)

    Tavakoli, Mohammad Mahdi; Zakeeruddin, Shaik Mohammed; Grätzel, Michael; Fan, Zhiyong

    2018-03-01

    Fast research progress on lead halide perovskite solar cells has been achieved in the past a few years. However, the presence of lead (Pb) in perovskite composition as a toxic element still remains a major issue for large-scale deployment. In this work, a novel and facile technique is presented to fabricate tin (Sn)-rich perovskite film using metal precursors and an alloying technique. Herein, the perovskite films are formed as a result of the reaction between Sn/Pb binary alloy metal precursors and methylammonium iodide (MAI) vapor in a chemical vapor deposition process carried out at 185 °C. It is found that in this approach the Pb/Sn precursors are first converted to (Pb/Sn)I 2 and further reaction with MAI vapor leads to the formation of perovskite films. By using Pb-Sn eutectic alloy, perovskite films with large grain sizes up to 5 µm can be grown directly from liquid phase metal. Consequently, using an alloying technique and this unique growth mechanism, a less-toxic and efficient perovskite solar cell with a power conversion efficiency (PCE) of 14.04% is demonstrated, while pure Sn and Pb perovskite solar cells prepared in this manner yield PCEs of 4.62% and 14.21%, respectively. It is found that this alloying technique can open up a new direction to further explore different alloy systems (binary or ternary alloys) with even lower melting point. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Models of large-scale magnetic fields in stellar interiors. Application to solar and ap stars

    International Nuclear Information System (INIS)

    Duez, Vincent

    2009-01-01

    Stellar astrophysics needs today new models of large-scale magnetic fields, which are observed through spectropolarimetry at the surface of Ap/Bp stars, and thought to be an explanation for the uniform rotation of the solar radiation zone, deduced from helio seismic inversions. During my PhD, I focused on describing the possible magnetic equilibria in stellar interiors. The found configurations are mixed poloidal-toroidal, and minimize the energy for a given helicity, in analogy with Taylor states encountered in spheromaks. Taking into account the self-gravity leads us to the 'non force-free' equilibria family, that will thus influence the stellar structure. I derived all the physical quantities associated with the magnetic field; then I evaluated the perturbations they induce on gravity, thermodynamic quantities as well as energetic ones, for a solar model and an Ap star. 3D MHD simulations allowed me to show that these equilibria form a first stable states family, the generalization of such states remaining an open question. It has been shown that a large-scale magnetic field confined in the solar radiation zone can induce an oblateness comparable to a high core rotation law. I also studied the secular interaction between the magnetic field, the differential rotation and the meridional circulation in the aim of implementing their effects in a next generation stellar evolution code. The influence of the magnetism on convection has also been studied. Finally, hydrodynamic processes responsible for the mixing have been compared with diffusion and a change of convection's efficiency in the case of a CoRoT star target. (author) [fr

  15. ITO with embedded silver grids as transparent conductive electrodes for large area organic solar cells

    DEFF Research Database (Denmark)

    Patil, Bhushan Ramesh; Mirsafaei, Mina; Cielecki, Pawel Piotr

    2017-01-01

    In this work, development of semi-transparent electrodes for efficient large area organic solar cells (OSCs) has been demonstrated. Electron beam evaporated silver grids were embedded in commercially available ITO coatings on glass, through a standard negative photolithography process, in order...... patterns. Solution processed bulk heterojunction OSCs based on PTB7:[70]PCBM were fabricated on top of these electrodes with cell areas of 4.38 cm2, and the performance of these OSCs was compared to reference cells fabricated on pure ITO electrodes. The Fill Factor of the large-scale OSCs fabricated on ITO...... with embedded Ag grids was enhanced by 18 % for the line grids pattern and 30 % for the square grids pattern compared to that of the reference OSCs. The increase in the Fill Factor was directly correlated to the decrease in the series resistance of the OSCs. The maximum power conversion efficiency (PCE...

  16. Total electron count variability and stratospheric ozone effects on solar backscatter and LWIR emissions

    Science.gov (United States)

    2017-03-10

    heating occur. This method is achieved though measuring the intensity ratio of sky- scattered sunlight at a pair of UV wavelengths at solar zenith angles...cause impacts to direct-sun, UV, and zenith measurements . OOB light can affect the low intensity spectrum of solar light, which is not fully removed by...several key spectral properties that are pertinent to its measurement . Ozone is greenhouse gas that plays a primary role in the absorption of solar UV

  17. CORONAL AND CHROMOSPHERIC SIGNATURES OF LARGE-SCALE DISTURBANCES ASSOCIATED WITH A MAJOR SOLAR ERUPTION

    Energy Technology Data Exchange (ETDEWEB)

    Zong, Weiguo [Key Laboratory of Space Weather, National Center for Space Weather, China Meteorological Administration, Beijing 100081 (China); Dai, Yu, E-mail: ydai@nju.edu.cn [Key Laboratory of Modern Astronomy and Astrophysics (Nanjing University), Ministry of Education, Nanjing 210023 (China)

    2015-08-20

    We present both coronal and chromospheric observations of large-scale disturbances associated with a major solar eruption on 2005 September 7. In the Geostationary Operational Environmental Satellites/Solar X-ray Imager (SXI), arclike coronal brightenings are recorded propagating in the southern hemisphere. The SXI front shows an initially constant speed of 730 km s{sup −1} and decelerates later on, and its center is near the central position angle of the associated coronal mass ejection (CME) but away from the flare site. Chromospheric signatures of the disturbances are observed in both Mauna Loa Solar Observatory (MLSO)/Polarimeter for Inner Coronal Studies Hα and MLSO/Chromospheric Helium I Imaging Photometer He i λ10830 and can be divided into two parts. The southern signatures occur in regions where the SXI front sweeps over, with the Hα bright front coincident with the SXI front, while the He i dark front lags the SXI front but shows a similar kinematics. Ahead of the path of the southern signatures, oscillations of a filament are observed. The northern signatures occur near the equator, with the Hα and He i fronts coincident with each other. They first propagate westward and then deflect to the north at the boundary of an equatorial coronal hole. Based on these observational facts, we suggest that the global disturbances are associated with the CME lift-off and show a hybrid nature: a mainly non-wave CME flank nature for the SXI signatures and the corresponding southern chromospheric signatures, and a shocked fast-mode coronal MHD wave nature for the northern chromospheric signatures.

  18. CORONAL AND CHROMOSPHERIC SIGNATURES OF LARGE-SCALE DISTURBANCES ASSOCIATED WITH A MAJOR SOLAR ERUPTION

    International Nuclear Information System (INIS)

    Zong, Weiguo; Dai, Yu

    2015-01-01

    We present both coronal and chromospheric observations of large-scale disturbances associated with a major solar eruption on 2005 September 7. In the Geostationary Operational Environmental Satellites/Solar X-ray Imager (SXI), arclike coronal brightenings are recorded propagating in the southern hemisphere. The SXI front shows an initially constant speed of 730 km s −1 and decelerates later on, and its center is near the central position angle of the associated coronal mass ejection (CME) but away from the flare site. Chromospheric signatures of the disturbances are observed in both Mauna Loa Solar Observatory (MLSO)/Polarimeter for Inner Coronal Studies Hα and MLSO/Chromospheric Helium I Imaging Photometer He i λ10830 and can be divided into two parts. The southern signatures occur in regions where the SXI front sweeps over, with the Hα bright front coincident with the SXI front, while the He i dark front lags the SXI front but shows a similar kinematics. Ahead of the path of the southern signatures, oscillations of a filament are observed. The northern signatures occur near the equator, with the Hα and He i fronts coincident with each other. They first propagate westward and then deflect to the north at the boundary of an equatorial coronal hole. Based on these observational facts, we suggest that the global disturbances are associated with the CME lift-off and show a hybrid nature: a mainly non-wave CME flank nature for the SXI signatures and the corresponding southern chromospheric signatures, and a shocked fast-mode coronal MHD wave nature for the northern chromospheric signatures

  19. Large-size, high-uniformity, random silver nanowire networks as transparent electrodes for crystalline silicon wafer solar cells.

    Science.gov (United States)

    Xie, Shouyi; Ouyang, Zi; Jia, Baohua; Gu, Min

    2013-05-06

    Metal nanowire networks are emerging as next generation transparent electrodes for photovoltaic devices. We demonstrate the application of random silver nanowire networks as the top electrode on crystalline silicon wafer solar cells. The dependence of transmittance and sheet resistance on the surface coverage is measured. Superior optical and electrical properties are observed due to the large-size, highly-uniform nature of these networks. When applying the nanowire networks on the solar cells with an optimized two-step annealing process, we achieved as large as 19% enhancement on the energy conversion efficiency. The detailed analysis reveals that the enhancement is mainly caused by the improved electrical properties of the solar cells due to the silver nanowire networks. Our result reveals that this technology is a promising alternative transparent electrode technology for crystalline silicon wafer solar cells.

  20. Performance Improvements of Selective Emitters by Laser Openings on Large-Area Multicrystalline Si Solar Cells

    Directory of Open Access Journals (Sweden)

    Sheng-Shih Wang

    2014-01-01

    Full Text Available This study focuses on the laser opening technique used to form a selective emitter (SE structure on multicrystalline silicon (mc-Si. This technique can be used in the large-area (156 × 156 mm2 solar cells. SE process of this investigation was performed using 3 samples SE1–SE3. Laser fluences can vary in range of 2–5 J/cm2. The optimal conversion efficiency of 15.95% is obtained with the SE3 (2 J/cm2 fluence after laser opening with optimization of heavy and light dopant, which yields a gain of 0.48%abs compared with that of a reference cell (without fluence. In addition, this optimal SE3 cell displays improved characteristics compared with other cells with a higher average value of external quantum efficiency (EQEavg = 68.6% and a lower average value of power loss (Ploss = 2.33 mW/cm2. For the fabrication of solar cells, the laser opening process comprises fewer steps than traditional photolithography does. Furthermore, the laser opening process decreases consumption of chemical materials; therefore, the laser opening process decreases both time and cost. Therefore, SE process is simple, cheap, and suitable for commercialization. Moreover, the prominent features of the process render it effective means to promote overall performance in the photovoltaic industry.

  1. The solar noise barrier project : 2. The effect of street art on performance of a large scale luminescent solar concentrator prototype

    NARCIS (Netherlands)

    Debije, M.G.; Tzikas, C.; Rajkumar, V.A.; de Jong, M.

    2017-01-01

    Noise barriers have been used worldwide to reduce the impact of sound generated from traffic on nearby areas. A common feature to appear on these noise barriers are all manner of graffiti and street art. In this work we describe the relative performance of a large area luminescent solar concentrator

  2. Light pollution offshore: Zenithal sky glow measurements in the mediterranean coastal waters

    Science.gov (United States)

    Ges, Xavier; Bará, Salvador; García-Gil, Manuel; Zamorano, Jaime; Ribas, Salvador J.; Masana, Eduard

    2018-05-01

    Light pollution is a worldwide phenomenon whose consequences for the natural environment and the human health are being intensively studied nowadays. Most published studies address issues related to light pollution inland. Coastal waters, however, are spaces of high environmental interest, due to their biodiversity richness and their economical significance. The elevated population density in coastal regions is accompanied by correspondingly large emissions of artificial light at night, whose role as an environmental stressor is increasingly being recognized. Characterizing the light pollution levels in coastal waters is a necessary step for protecting these areas. At the same time, the marine surface environment provides a stage free from obstacles for measuring the dependence of the skyglow on the distance to the light polluting sources, and validating (or rejecting) atmospheric light propagation models. In this work we present a proof-of-concept of a gimbal measurement system that can be used for zenithal skyglow measurements on board both small boats and large vessels under actual navigation conditions. We report the results obtained in the summer of 2016 along two measurement routes in the Mediterranean waters offshore Barcelona, travelling 9 and 31.7 km away from the coast. The atmospheric conditions in both routes were different from the ones assumed for the calculation of recently published models of the anthropogenic sky brightness. They were closer in the first route, whose results approach better the theoretical predictions. The results obtained in the second route, conducted under a clearer atmosphere, showed systematic differences that can be traced back to two expected phenomena, which are a consequence of the smaller aerosol content: the reduction of the anthropogenic sky glow at short distances from the sources, and the slower decay rate of brightness with distance, which gives rise to a relative excess of brightness at large distances from the

  3. Parameterization of Cherenkov Light Lateral Distribution Function as a Function of the Zenith Angle around the Knee Region

    OpenAIRE

    Abdulsttar, Marwah M.; Al-Rubaiee, A. A.; Ali, Abdul Halim Kh.

    2016-01-01

    Cherenkov light lateral distribution function (CLLDF) simulation was fulfilled using CORSIKA code for configurations of Tunka EAS array of different zenith angles. The parameterization of the CLLDF was carried out as a function of the distance from the shower core in extensive air showers (EAS) and zenith angle on the basis of the CORSIKA simulation of primary proton around the knee region with the energy 3.10^15 eV at different zenith angles. The parameterized CLLDF is verified in comparison...

  4. Large scale circulation in the convection zone and solar differential rotation

    Energy Technology Data Exchange (ETDEWEB)

    Belvedere, G [Instituto di Astronomia dell' Universita di Catania, 95125 Italy; Paterno, L [Osservatorio Astrofisico di Catania, 95125 Italy

    1976-04-01

    In this paper the dependence on depth and latitude of the solar angular velocity produced by a meridian circulation in the convection zone is studied assuming that the main mechanism responsible for setting up and driving the circulation is the interaction of rotation with convection. The first order equations (perturbation of the spherically symmetric state are solved in the Boussinesq approximation and in the steady state for the axissymmetric case. The interaction of convection with rotation is modelled by a convective transport coefficient. The model is consistent with the fact that the interaction of convection with rotation sets up a circulation (driven by the temperature gradient) which carries angular momentum toward the equator against the viscous friction. Unfortunately also a large flux variation at the surface is obtained. Nevertheless it seems that the model has the basic requisites for correct dynamo action.

  5. Large guanidinium cation mixed with methylammonium in lead iodide perovskites for 19% efficient solar cells

    Science.gov (United States)

    Jodlowski, Alexander D.; Roldán-Carmona, Cristina; Grancini, Giulia; Salado, Manuel; Ralaiarisoa, Maryline; Ahmad, Shahzada; Koch, Norbert; Camacho, Luis; de Miguel, Gustavo; Nazeeruddin, Mohammad Khaja

    2017-12-01

    Organic-inorganic lead halide perovskites have shown photovoltaic performances above 20% in a range of solar cell architectures while offering simple and low-cost processability. Despite the multiple ionic compositions that have been reported so far, the presence of organic constituents is an essential element in all of the high-efficiency formulations, with the methylammonium and formamidinium cations being the sole efficient options available to date. In this study, we demonstrate improved material stability after the incorporation of a large organic cation, guanidinium, into the MAPbI3 crystal structure, which delivers average power conversion efficiencies over 19%, and stabilized performance for 1,000 h under continuous light illumination, a fundamental step within the perovskite field.

  6. Onset of a Large Ejective Solar Eruption from a Typical Coronal-jet-base Field Configuration

    Energy Technology Data Exchange (ETDEWEB)

    Joshi, Navin Chandra; Magara, Tetsuya; Moon, Yong-Jae [School of Space Research, Kyung Hee University, Yongin, Gyeonggi-Do, 446-701 (Korea, Republic of); Sterling, Alphonse C.; Moore, Ronald L., E-mail: navin@khu.ac.kr, E-mail: njoshi98@gmail.com [NASA Marshall Space Flight Center, Huntsville, AL 35812 (United States)

    2017-08-10

    Utilizing multiwavelength observations and magnetic field data from the Solar Dynamics Observatory ( SDO )/Atmospheric Imaging Assembly (AIA), SDO /Helioseismic and Magnetic Imager (HMI), the Geostationary Operational Environmental Satellite ( GOES ), and RHESSI , we investigate a large-scale ejective solar eruption of 2014 December 18 from active region NOAA 12241. This event produced a distinctive “three-ribbon” flare, having two parallel ribbons corresponding to the ribbons of a standard two-ribbon flare, and a larger-scale third quasi-circular ribbon offset from the other two. There are two components to this eruptive event. First, a flux rope forms above a strong-field polarity inversion line and erupts and grows as the parallel ribbons turn on, grow, and spread apart from that polarity inversion line; this evolution is consistent with the mechanism of tether-cutting reconnection for eruptions. Second, the eruption of the arcade that has the erupting flux rope in its core undergoes magnetic reconnection at the null point of a fan dome that envelops the erupting arcade, resulting in formation of the quasi-circular ribbon; this is consistent with the breakout reconnection mechanism for eruptions. We find that the parallel ribbons begin well before (∼12 minutes) the onset of the circular ribbon, indicating that tether-cutting reconnection (or a non-ideal MHD instability) initiated this event, rather than breakout reconnection. The overall setup for this large-scale eruption (diameter of the circular ribbon ∼10{sup 5} km) is analogous to that of coronal jets (base size ∼10{sup 4} km), many of which, according to recent findings, result from eruptions of small-scale “minifilaments.” Thus these findings confirm that eruptions of sheared-core magnetic arcades seated in fan–spine null-point magnetic topology happen on a wide range of size scales on the Sun.

  7. Microscopic observation of zenithal bistable switching in nematic devices with different surface relief structures

    International Nuclear Information System (INIS)

    Uche, C; Elston, S J; Parry-Jones, L A

    2005-01-01

    Nematic liquid crystals have been shown to exhibit zenithal electro-optic bistability in devices containing sinusoidal and deformed sinusoidal gratings. Recently it has been shown that zenithal bistable states can also be supported at isolated edges of square gratings. In this paper, we present microscopic observations of bistability in cells containing sinusoidal gratings and long-pitch square gratings. We have also investigated a novel display based on square wells. High frame-rate video microscopy was used to obtain time-sequenced images when the devices were switched with monopolar pulses. These show that zenithal bistable switching can occur by two different processes: (i) domain growth (observed in cells containing sinusoidal gratings) and (ii) homogenous switching (observed in cells containing isolated edges

  8. ITO with embedded silver grids as transparent conductive electrodes for large area organic solar cells

    Science.gov (United States)

    Patil, Bhushan R.; Mirsafaei, Mina; Piotr Cielecki, Paweł; Fernandes Cauduro, André Luis; Fiutowski, Jacek; Rubahn, Horst-Günter; Madsen, Morten

    2017-10-01

    In this work, development of semi-transparent electrodes for efficient large area organic solar cells (OSCs) has been demonstrated. Electron beam evaporated silver grids were embedded in commercially available ITO coatings on glass, through a standard negative photolithography process, in order to improve the conductivity of planar ITO substrates. The fabricated electrodes with embedded line and square patterned Ag grids reduced the sheet resistance of ITO by 25% and 40%, respectively, showing optical transmittance drops of less than 6% within the complete visible light spectrum for both patterns. Solution processed bulk heterojunction OSCs based on PTB7:[70]PCBM were fabricated on top of these electrodes with cell areas of 4.38 cm2, and the performance of these OSCs was compared to reference cells fabricated on pure ITO electrodes. The Fill Factor (FF) of the large-scale OSCs fabricated on ITO with embedded Ag grids was enhanced by 18% for the line grids pattern and 30% for the square grids pattern compared to that of the reference OSCs. The increase in the FF was directly correlated to the decrease in the series resistance of the OSCs. The maximum power conversion efficiency (PCE) of the OSCs was measured to be 4.34%, which is 23% higher than the PCE of the reference OSCs. As the presented method does not involve high temperature processing, it could be considered a general approach for development of large area organic electronics on solvent resistant, flexible substrates.

  9. Inclined Zenith Aurora over Kyoto on 17 September 1770: Graphical Evidence of Extreme Magnetic Storm

    Science.gov (United States)

    Kataoka, Ryuho; Iwahashi, Kiyomi

    2017-10-01

    Red auroras were observed in Japan during an extreme magnetic storm that occurred on 17 September 1770. We show new evidence that the red aurora extended toward the zenith of Kyoto around midnight. The basic appearance of the historical painting of the red aurora is geometrically reproduced based on the inclination of the local magnetic field and a detailed description in a newly discovered diary. The presence of the inclined zenith aurora over Kyoto suggests that the intensity of the September 1770 magnetic storm is comparable to, or slightly larger than that of the September 1859 Carrington storm.

  10. Dependence on zenith angle of the strength of 3-meter equatorial electrojet irregularities

    International Nuclear Information System (INIS)

    Ierkic, H.M.; Fejer, B.G.; Farley, D.T.

    1980-01-01

    Radar measurements in Peru were used to deduce the zenith angle dependence of the scattering cross section of plasma irregularities generated by instabilities in the equatorial electrojet. The irregularities probed by the 50 MHz Jicamarca radar had a wavelength of 3m. The cross section for the type 2 irregularities was isotopic in the plane perpendicular to the magnetic field, while the cross section for the stronger type 1 irregularities varied with zenith angle at a rate of approximately 0.3 dB/degree; the horizontally traveling waves were more than 100 times stronger than those traveling vertically

  11. Effects of large scale integration of wind and solar energy in Japan

    Science.gov (United States)

    Esteban, Miguel; Zhang, Qi; Utama, Agya; Tezuka, Tetsuo; Ishihara, Keiichi

    2010-05-01

    results for the country as a whole are considered it is still substantial. The results are greatly dependant on the mix between the proposed renewables (solar and wind), and by comparing different distributions and mixes, the optimum composition for the target country can be established. The methodology proposed is able to obtain the optimum mix of solar and wind power for a given system, provided that adequate storage capacity exists to allow for excess capacity to be used at times of low electricity production (at the comparatively rare times when there is neither enough sun nor wind throughout the country). This highlights the challenges of large-scale integration of renewable technologies into the electricity grid, and the necessity to combine such a system with other renewables such as hydro or ocean energy to further even out the peaks and lows in the demand.

  12. Modeling the acute health effects of astronauts from exposure to large solar particle events.

    Science.gov (United States)

    Hu, Shaowen; Kim, Myung-Hee Y; McClellan, Gene E; Cucinotta, Francis A

    2009-04-01

    Radiation exposure from Solar Particle Events (SPE) presents a significant health concern for astronauts for exploration missions outside the protection of the Earth's magnetic field, which could impair their performance and result in the possibility of failure of the mission. Assessing the potential for early radiation effects under such adverse conditions is of prime importance. Here we apply a biologically based mathematical model that describes the dose- and time-dependent early human responses that constitute the prodromal syndromes to consider acute risks from SPEs. We examine the possible early effects on crews from exposure to some historically large solar events on lunar and/or Mars missions. The doses and dose rates of specific organs were calculated using the Baryon radiation transport (BRYNTRN) code and a computerized anatomical man model, while the hazard of the early radiation effects and performance reduction were calculated using the Radiation-Induced Performance Decrement (RIPD) code. Based on model assumptions we show that exposure to these historical events would cause moderate early health effects to crew members inside a typical spacecraft or during extra-vehicular activities, if effective shielding and medical countermeasure tactics were not provided. We also calculate possible even worse cases (double intensity, multiple occurrences in a short period of time, etc.) to estimate the severity, onset and duration of various types of early illness. Uncertainties in the calculation due to limited data on relative biological effectiveness and dose-rate modifying factors for protons and secondary radiation, and the identification of sensitive sites in critical organs are discussed.

  13. The role of printing techniques for large-area dye sensitized solar cells

    International Nuclear Information System (INIS)

    Mariani, Paolo; Vesce, Luigi; Di Carlo, Aldo

    2015-01-01

    The versatility of printing technologies and their intrinsic ability to outperform other techniques in large-area deposition gives scope to revolutionize the photovoltaic (PV) manufacturing field. Printing methods are commonly used in conventional silicon-based PVs to cover part of the production process. Screen printing techniques, for example, are applied to deposit electrical contacts on the silicon wafer. However, it is with the advent of third generation PVs that printing/coating techniques have been extensively used in almost all of the manufacturing processes. Among all the third generation PVs, dye sensitized solar cell (DSSC) technology has been developed up to commercialization levels. DSSCs and modules can be fabricated by adopting all of the main printing techniques on both rigid and flexible substrates. This allows an easy tuning of cell/module characteristics to the desired application. Transparency, colour, shape, layout and other DSSC’s features can be easily varied by changing the printing parameters and paste/ink formulations used in the printing process. This review focuses on large-area printing/coating technologies for the fabrication of DSSCs devices. The most used and promising techniques are presented underlining the process parameters and applications. (paper)

  14. The role of printing techniques for large-area dye sensitized solar cells

    Science.gov (United States)

    Mariani, Paolo; Vesce, Luigi; Di Carlo, Aldo

    2015-10-01

    The versatility of printing technologies and their intrinsic ability to outperform other techniques in large-area deposition gives scope to revolutionize the photovoltaic (PV) manufacturing field. Printing methods are commonly used in conventional silicon-based PVs to cover part of the production process. Screen printing techniques, for example, are applied to deposit electrical contacts on the silicon wafer. However, it is with the advent of third generation PVs that printing/coating techniques have been extensively used in almost all of the manufacturing processes. Among all the third generation PVs, dye sensitized solar cell (DSSC) technology has been developed up to commercialization levels. DSSCs and modules can be fabricated by adopting all of the main printing techniques on both rigid and flexible substrates. This allows an easy tuning of cell/module characteristics to the desired application. Transparency, colour, shape, layout and other DSSC’s features can be easily varied by changing the printing parameters and paste/ink formulations used in the printing process. This review focuses on large-area printing/coating technologies for the fabrication of DSSCs devices. The most used and promising techniques are presented underlining the process parameters and applications.

  15. The effect of random matter density perturbations on the large mixing angle solution to the solar neutrino problem

    Science.gov (United States)

    Guzzo, M. M.; Holanda, P. C.; Reggiani, N.

    2003-08-01

    The neutrino energy spectrum observed in KamLAND is compatible with the predictions based on the Large Mixing Angle realization of the MSW (Mikheyev-Smirnov-Wolfenstein) mechanism, which provides the best solution to the solar neutrino anomaly. From the agreement between solar neutrino data and KamLAND observations, we can obtain the best fit values of the mixing angle and square difference mass. When doing the fitting of the MSW predictions to the solar neutrino data, it is assumed the solar matter do not have any kind of perturbations, that is, it is assumed the the matter density monothonically decays from the center to the surface of the Sun. There are reasons to believe, nevertheless, that the solar matter density fluctuates around the equilibrium profile. In this work, we analysed the effect on the Large Mixing Angle parameters when the density matter randomically fluctuates around the equilibrium profile, solving the evolution equation in this case. We find that, in the presence of these density perturbations, the best fit values of the mixing angle and the square difference mass assume smaller values, compared with the values obtained for the standard Large Mixing Angle Solution without noise. Considering this effect of the random perturbations, the lowest island of allowed region for KamLAND spectral data in the parameter space must be considered and we call it very-low region.

  16. A new method of presentation the large-scale magnetic field structure on the Sun and solar corona

    Science.gov (United States)

    Ponyavin, D. I.

    1995-01-01

    The large-scale photospheric magnetic field, measured at Stanford, has been analyzed in terms of surface harmonics. Changes of the photospheric field which occur within whole solar rotation period can be resolved by this analysis. For this reason we used daily magnetograms of the line-of-sight magnetic field component observed from Earth over solar disc. We have estimated the period during which day-to-day full disc magnetograms must be collected. An original algorithm was applied to resolve time variations of spherical harmonics that reflect time evolution of large-scale magnetic field within solar rotation period. This method of magnetic field presentation can be useful enough in lack of direct magnetograph observations due to sometimes bad weather conditions. We have used the calculated surface harmonics to reconstruct the large-scale magnetic field structure on the source surface near the sun - the origin of heliospheric current sheet and solar wind streams. The obtained results have been compared with spacecraft in situ observations and geomagnetic activity. We tried to show that proposed technique can trace shon-time variations of heliospheric current sheet and short-lived solar wind streams. We have compared also our results with those obtained traditionally from potential field approximation and extrapolation using synoptic charts as initial boundary conditions.

  17. High-Temperature-Short-Time Annealing Process for High-Performance Large-Area Perovskite Solar Cells.

    Science.gov (United States)

    Kim, Minjin; Kim, Gi-Hwan; Oh, Kyoung Suk; Jo, Yimhyun; Yoon, Hyun; Kim, Ka-Hyun; Lee, Heon; Kim, Jin Young; Kim, Dong Suk

    2017-06-27

    Organic-inorganic hybrid metal halide perovskite solar cells (PSCs) are attracting tremendous research interest due to their high solar-to-electric power conversion efficiency with a high possibility of cost-effective fabrication and certified power conversion efficiency now exceeding 22%. Although many effective methods for their application have been developed over the past decade, their practical transition to large-size devices has been restricted by difficulties in achieving high performance. Here we report on the development of a simple and cost-effective production method with high-temperature and short-time annealing processing to obtain uniform, smooth, and large-size grain domains of perovskite films over large areas. With high-temperature short-time annealing at 400 °C for 4 s, the perovskite film with an average domain size of 1 μm was obtained, which resulted in fast solvent evaporation. Solar cells fabricated using this processing technique had a maximum power conversion efficiency exceeding 20% over a 0.1 cm 2 active area and 18% over a 1 cm 2 active area. We believe our approach will enable the realization of highly efficient large-area PCSs for practical development with a very simple and short-time procedure. This simple method should lead the field toward the fabrication of uniform large-scale perovskite films, which are necessary for the production of high-efficiency solar cells that may also be applicable to several other material systems for more widespread practical deployment.

  18. SWAP OBSERVATIONS OF THE LONG-TERM, LARGE-SCALE EVOLUTION OF THE EXTREME-ULTRAVIOLET SOLAR CORONA

    Energy Technology Data Exchange (ETDEWEB)

    Seaton, Daniel B.; De Groof, Anik; Berghmans, David; Nicula, Bogdan [Royal Observatory of Belgium-SIDC, Avenue Circulaire 3, B-1180 Brussels (Belgium); Shearer, Paul [Department of Mathematics, 2074 East Hall, University of Michigan, 530 Church Street, Ann Arbor, MI 48109-1043 (United States)

    2013-11-01

    The Sun Watcher with Active Pixels and Image Processing (SWAP) EUV solar telescope on board the Project for On-Board Autonomy 2 spacecraft has been regularly observing the solar corona in a bandpass near 17.4 nm since 2010 February. With a field of view of 54 × 54 arcmin, SWAP provides the widest-field images of the EUV corona available from the perspective of the Earth. By carefully processing and combining multiple SWAP images, it is possible to produce low-noise composites that reveal the structure of the EUV corona to relatively large heights. A particularly important step in this processing was to remove instrumental stray light from the images by determining and deconvolving SWAP's point-spread function from the observations. In this paper, we use the resulting images to conduct the first-ever study of the evolution of the large-scale structure of the corona observed in the EUV over a three year period that includes the complete rise phase of solar cycle 24. Of particular note is the persistence over many solar rotations of bright, diffuse features composed of open magnetic fields that overlie polar crown filaments and extend to large heights above the solar surface. These features appear to be related to coronal fans, which have previously been observed in white-light coronagraph images and, at low heights, in the EUV. We also discuss the evolution of the corona at different heights above the solar surface and the evolution of the corona over the course of the solar cycle by hemisphere.

  19. Potential for large-scale solar collector system to offset carbon-based heating in the Ontario greenhouse sector

    Science.gov (United States)

    Semple, Lucas M.; Carriveau, Rupp; Ting, David S.-K.

    2018-04-01

    In the Ontario greenhouse sector the misalignment of available solar radiation during the summer months and large heating demand during the winter months makes solar thermal collector systems an unviable option without some form of seasonal energy storage. Information obtained from Ontario greenhouse operators has shown that over 20% of annual natural gas usage occurs during the summer months for greenhouse pre-heating prior to sunrise. A transient model of the greenhouse microclimate and indoor conditioning systems is carried out using TRNSYS software and validated with actual natural gas usage data. A large-scale solar thermal collector system is then incorporated and found to reduce the annual heating energy demand by approximately 35%. The inclusion of the collector system correlates to a reduction of about 120 tonnes of CO2 equivalent emissions per acre of greenhouse per year. System payback period is discussed considering the benefits of a future Ontario carbon tax.

  20. An interim report on the second loading of Zenith. Preliminary report

    Energy Technology Data Exchange (ETDEWEB)

    Absalom, R M; Barclay, F R; Cameron, I R; Collins, A G; Della Loggia, V E; Freemantle, R G; Hage, W; Kinchin, G H; Sanders, J E; Tiren, L I; Wilson, D J

    1961-02-15

    The loading to criticality of the second core of the high-temperature zero-energy reactor ZENITH and the results of the subsequent experimental programme are described. The composition of the reactor core corresponds to graphite: U235 and TH232 : U235 atomic ratios of 2107 and 4.75 respectively.

  1. Zenith distribution and flux of atmospheric muons measured with the 5-line ANTARES detector

    NARCIS (Netherlands)

    Aguilar, J. A.; Albert, A.; Anton, G.; Anvar, S.; Ardid, M.; Jesus, A. C. Assis; Astraatmadja, T.; Aubertg, J. -J.; Auer, R.; Baret, B.; Basa, S.; Bazzotti, M.; Berting, V.; Biagi, S.; Bigongiari, C.; Bou-Cabo, M.; Bouwhuis, M. C.; Brown, A. M.; Brunnerg, J.; Busto, J.; Camarena, F.; Capone, A.; Carminati, G.; Carr, J.; Castel, D.; Castorina, E.; Cavasinni, V.; Cecchini, S.; Charvis, Ph.; Chiarusi, T.; Circella, M.; Coniglione, R.; Costantini, H.; Cottini, N.; Coyle, P.; Curtil, C.; De Bonis, G.; Decowski, M. P.; Dekeyser, I.; Deschamps, A.; Distefano, C.; Donzaud, C.; Dornic, D.; Drouhin, D.; Eberl, T.; Emanuele, U.; Ernenweing, J. -P.; Kalantar-Nayestanaki, N.; Kretschmer, W.; Loehner, H.

    2010-01-01

    The ANTARES high-energy neutrino telescope is a three-dimensional array of about 900 photomultipliers distributed over 12 mooring lines installed in the Mediterranean Sea. Between February and November 2007 it acquired data in a 5-line configuration. The zenith angular distribution of the

  2. The Zenith Passage of the Sun at the Mesoamerican Sites of Tula and Chichen Itza

    OpenAIRE

    Sparavigna, Amelia Carolina

    2017-01-01

    International audience; Using software SunCalc.org we can easily observe the alignments of buildings along the direction of the sunset on the day of the zenith passage of the sun, at two Mesoamerican sites. These sites are those of Tula and Chichen Itza.

  3. Zenith-angle distributions of atmospheric muons above 20 GeV

    International Nuclear Information System (INIS)

    Decoster, R.J.; Stevenson, M.L.; Breakstone, A.; Flatte, S.M.

    1975-01-01

    The results of a magnetic-spectrometer experiment at ground level with optical spark chambers, scintillator hodoscope trigger and an air-gap magnet, are reported to given an evaluation of the zenith-angle distribution of the atmospheric muons above 20 GeV. An automatic flying spot digitizer, the Hummingbird, was used

  4. Thermal Performance of a Large Low Flow Solar Heating System with a Highly Thermally Stratified Tank

    DEFF Research Database (Denmark)

    Furbo, Simon; Vejen, Niels Kristian; Shah, Louise Jivan

    2005-01-01

    are facing west. The collector tilt is 15° from horizontal for all collectors. Both the east-facing and the west-facing collectors have their own solar collector loop, circulation pump, external heat exchanger and control system. The external heat exchangers are used to transfer the heat from the solar......In year 2000 a 336 m² solar domestic hot water system was built in Sundparken, Elsinore, Denmark. The solar heating system is a low flow system with a 10000 l hot-water tank. Due to the orientation of the buildings half of the solar collectors are facing east, half of the solar collectors...... collector fluid to the domestic water. The domestic water is pumped from the bottom of the hot-water tank to the heat exchanger and back to the hot-water tank through stratification inlet pipes. The return flow from the DHW circulation pipe also enters the tank through stratification inlet pipes. The tank...

  5. Short- and medium-term atmospheric constituent effects of very large solar proton events

    Directory of Open Access Journals (Sweden)

    C. H. Jackman

    2008-02-01

    Full Text Available Solar eruptions sometimes produce protons, which impact the Earth's atmosphere. These solar proton events (SPEs generally last a few days and produce high energy particles that precipitate into the Earth's atmosphere. The protons cause ionization and dissociation processes that ultimately lead to an enhancement of odd-hydrogen and odd-nitrogen in the polar cap regions (>60° geomagnetic latitude. We have used the Whole Atmosphere Community Climate Model (WACCM3 to study the atmospheric impact of SPEs over the period 1963–2005. The very largest SPEs were found to be the most important and caused atmospheric effects that lasted several months after the events. We present the short- and medium-term (days to a few months atmospheric influence of the four largest SPEs in the past 45 years (August 1972; October 1989; July 2000; and October–November 2003 as computed by WACCM3 and observed by satellite instruments. Polar mesospheric NOx (NO+NO2 increased by over 50 ppbv and mesospheric ozone decreased by over 30% during these very large SPEs. Changes in HNO3, N2O5, ClONO2, HOCl, and ClO were indirectly caused by the very large SPEs in October–November 2003, were simulated by WACCM3, and previously measured by Envisat Michelson Interferometer for Passive Atmospheric Sounding (MIPAS. WACCM3 output was also represented by sampling with the MIPAS averaging kernel for a more valid comparison. Although qualitatively similar, there are discrepancies between the model and measurement with WACCM3 predicted HNO3 and ClONO2 enhancements being smaller than measured and N2O5 enhancements being larger than measured. The HOCl enhancements were fairly similar in amounts and temporal variation in WACCM3 and MIPAS. WACCM3 simulated ClO decreases below 50 km, whereas MIPAS mainly observed increases, a very perplexing difference. Upper stratospheric

  6. Lightning Surge Analysis on a Large Scale Grid-Connected Solar Photovoltaic System

    OpenAIRE

    Nur Hazirah Zaini; Mohd Zainal Abidin Ab. Kadir; Mohd Amran Mohd Radzi; Mahdi Izadi; Norhafiz Azis; Nor Izzati Ahmad; Mohd Solehin Mohd Nasir

    2017-01-01

    Solar photovoltaic (PV) farms currently play a vital role in the generation of electrical power in different countries, such as Malaysia, which is moving toward the use of renewable energy. Malaysia is one of the countries with abundant sunlight and thus can use solar PV farms as alternative sources for electricity generation. However, lightning strikes frequently occur in the country. Being installed in open and flat areas, solar PV farms, especially their electronic components, are at great...

  7. Application of lightweight materials in structure concept design of large-scale solar energy unmanned aerial vehicle

    Science.gov (United States)

    Zhang, Wei; Lv, Shengli; Guan, XiQi

    2017-09-01

    Carbon fiber composites and film materials can be effectively used in light aircraft structures, especially for solar unmanned aerial vehicles. The use of light materials can reduce the weight of the aircraft, but also can effectively improve the aircraft's strength and stiffness. The structure of the large aspect ratio solar energy UAV was analyzed in detail, taking Solar-impulse solar aircraft as an example. The solar energy UAV has a wing aspect ratio greater than 20, and the detailed digital model of the wing structure including beam, ribs and skin was built, also the Finite Element Method was applied to analyze the static and dynamic performance of the structure. The upper skin of the wing is covered with silicon solar cells, while the lower skin is light and transparent film. The single beam truss form of carbon fiber lightweight material is used in the wing structure. The wing beam is a box beam with rectangular cross sections. The box beam connected the front parts and after parts of the ribs together. The fuselage of the aircraft was built by space truss structure. According to the static and dynamic analysis with Finite Element method, it was found that the aircraft has a small wingtip deflection relative to the wingspan in the level flight state. The first natural frequency of the wing structure is pretty low, which is closed to the gust load.

  8. All polymer photovoltaics: From small inverted devices to large roll-to-roll coated and printed solar cells

    DEFF Research Database (Denmark)

    Liu, Yao; Larsen-Olsen, Thue Trofod; Zhao, Xingang

    2013-01-01

    Inverted all polymer solar cells based on a blend of a perylene diimide based polymer acceptor and a dithienosilole based polymer donor were fabricated from small area devices to roll-to-roll (R2R) coated and printed large area modules. The device performance was successfully optimized by using...

  9. A round robin study of flexible large-area roll-to-roll processed polymer solar cell modules

    DEFF Research Database (Denmark)

    Krebs, Frederik C; Gevorgyan, Suren; Gholamkhass, Bobak

    2009-01-01

    A round robin for the performance of roll-to-roll coated flexible large-area polymer solar-cell modules involving 18 different laboratories in Northern America, Europe and Middle East is presented. The study involved the performance measurement of the devices at one location (Risø DTU) followed b...

  10. Solution processed large area fabrication of Ag patterns as electrodes for flexible heaters, electrochromics and organic solar cells

    DEFF Research Database (Denmark)

    Gupta, Ritu; Walia, Sunil; Hösel, Markus

    2014-01-01

    , the process takes only a few minutes without any expensive instrumentation. The electrodes exhibited excellent adhesion and mechanical properties, important for flexible device application. Using Ag patterned electrodes, heaters operating at low voltages, pixelated electrochromic displays as well as organic...... solar cells have been demonstrated. The method is extendable to produce defect-free patterns over large areas as demonstrated by roll coating....

  11. Probabilistic Solar Wind Forecasting Using Large Ensembles of Near-Sun Conditions With a Simple One-Dimensional "Upwind" Scheme

    Science.gov (United States)

    Owens, Mathew J.; Riley, Pete

    2017-11-01

    Long lead-time space-weather forecasting requires accurate prediction of the near-Earth solar wind. The current state of the art uses a coronal model to extrapolate the observed photospheric magnetic field to the upper corona, where it is related to solar wind speed through empirical relations. These near-Sun solar wind and magnetic field conditions provide the inner boundary condition to three-dimensional numerical magnetohydrodynamic (MHD) models of the heliosphere out to 1 AU. This physics-based approach can capture dynamic processes within the solar wind, which affect the resulting conditions in near-Earth space. However, this deterministic approach lacks a quantification of forecast uncertainty. Here we describe a complementary method to exploit the near-Sun solar wind information produced by coronal models and provide a quantitative estimate of forecast uncertainty. By sampling the near-Sun solar wind speed at a range of latitudes about the sub-Earth point, we produce a large ensemble (N = 576) of time series at the base of the Sun-Earth line. Propagating these conditions to Earth by a three-dimensional MHD model would be computationally prohibitive; thus, a computationally efficient one-dimensional "upwind" scheme is used. The variance in the resulting near-Earth solar wind speed ensemble is shown to provide an accurate measure of the forecast uncertainty. Applying this technique over 1996-2016, the upwind ensemble is found to provide a more "actionable" forecast than a single deterministic forecast; potential economic value is increased for all operational scenarios, but particularly when false alarms are important (i.e., where the cost of taking mitigating action is relatively large).

  12. Probabilistic Solar Wind Forecasting Using Large Ensembles of Near-Sun Conditions With a Simple One-Dimensional "Upwind" Scheme.

    Science.gov (United States)

    Owens, Mathew J; Riley, Pete

    2017-11-01

    Long lead-time space-weather forecasting requires accurate prediction of the near-Earth solar wind. The current state of the art uses a coronal model to extrapolate the observed photospheric magnetic field to the upper corona, where it is related to solar wind speed through empirical relations. These near-Sun solar wind and magnetic field conditions provide the inner boundary condition to three-dimensional numerical magnetohydrodynamic (MHD) models of the heliosphere out to 1 AU. This physics-based approach can capture dynamic processes within the solar wind, which affect the resulting conditions in near-Earth space. However, this deterministic approach lacks a quantification of forecast uncertainty. Here we describe a complementary method to exploit the near-Sun solar wind information produced by coronal models and provide a quantitative estimate of forecast uncertainty. By sampling the near-Sun solar wind speed at a range of latitudes about the sub-Earth point, we produce a large ensemble (N = 576) of time series at the base of the Sun-Earth line. Propagating these conditions to Earth by a three-dimensional MHD model would be computationally prohibitive; thus, a computationally efficient one-dimensional "upwind" scheme is used. The variance in the resulting near-Earth solar wind speed ensemble is shown to provide an accurate measure of the forecast uncertainty. Applying this technique over 1996-2016, the upwind ensemble is found to provide a more "actionable" forecast than a single deterministic forecast; potential economic value is increased for all operational scenarios, but particularly when false alarms are important (i.e., where the cost of taking mitigating action is relatively large).

  13. Influence of large-scale deployment of concentrated solar power on North African countries: Socio-economic aspects (Conference Paper)

    OpenAIRE

    Komendantova, N.; Patt, A.

    2010-01-01

    To prevent catastrophic results of climate change, the stabilization of atmospheric concentrations of CO2 below 450 or even 350 parts per million is necessary. The large-scale electricity generation from renewable energy sources is one of possible options to satisfy the world's growing energy demand and to reduce green house gas emissions from electricity generation. Several studies show technical viability of large-scale deployment of concentrated solar power in North African countries and i...

  14. Large area, low cost space solar cells with optional wraparound contacts

    Science.gov (United States)

    Michaels, D.; Mendoza, N.; Williams, R.

    1981-01-01

    Design parameters for two large area, low cost solar cells are presented, and electron irradiation testing, thermal alpha testing, and cell processing are discussed. The devices are a 2 ohm-cm base resistivity silicon cell with an evaporated aluminum reflector produced in a dielectric wraparound cell, and a 10 ohm-cm silicon cell with the BSF/BSR combination and a conventional contact system. Both cells are 5.9 x 5.9 cm and require 200 micron thick silicon material due to mission weight constraints. Normalized values for open circuit voltage, short circuit current, and maximum power calculations derived from electron radiation testing are given. In addition, thermal alpha testing values of absorptivity and emittance are included. A pilot cell processing run produced cells averaging 14.4% efficiencies at AMO 28 C. Manufacturing for such cells will be on a mechanized process line, and the area of coverslide application technology must be considered in order to achieve cost effective production.

  15. Dynamics of large-scale solar wind streams obtained by the double superposed epoch analysis

    Science.gov (United States)

    Yermolaev, Yu. I.; Lodkina, I. G.; Nikolaeva, N. S.; Yermolaev, M. Yu.

    2015-09-01

    Using the OMNI data for period 1976-2000, we investigate the temporal profiles of 20 plasma and field parameters in the disturbed large-scale types of solar wind (SW): corotating interaction regions (CIR), interplanetary coronal mass ejections (ICME) (both magnetic cloud (MC) and Ejecta), and Sheath as well as the interplanetary shock (IS). To take into account the different durations of SW types, we use the double superposed epoch analysis (DSEA) method: rescaling the duration of the interval for all types in such a manner that, respectively, beginning and end for all intervals of selected type coincide. As the analyzed SW types can interact with each other and change parameters as a result of such interaction, we investigate separately eights sequences of SW types: (1) CIR, (2) IS/CIR, (3) Ejecta, (4) Sheath/Ejecta, (5) IS/Sheath/Ejecta, (6) MC, (7) Sheath/MC, and (8) IS/Sheath/MC. The main conclusion is that the behavior of parameters in Sheath and in CIR are very similar both qualitatively and quantitatively. Both the high-speed stream (HSS) and the fast ICME play a role of pistons which push the plasma located ahead them. The increase of speed in HSS and ICME leads at first to formation of compression regions (CIR and Sheath, respectively) and then to IS. The occurrence of compression regions and IS increases the probability of growth of magnetospheric activity.

  16. SEISMOLOGY OF A LARGE SOLAR CORONAL LOOP FROM EUVI/STEREO OBSERVATIONS OF ITS TRANSVERSE OSCILLATION

    International Nuclear Information System (INIS)

    Verwichte, E.; Van Doorsselaere, T.; Foullon, C.; Nakariakov, V. M.; Aschwanden, M. J.

    2009-01-01

    The first analysis of a transverse loop oscillation observed by both Solar TErrestrial RElations Observatories (STEREO) spacecraft is presented, for an event on the 2007 June 27 as seen by the Extreme Ultraviolet Imager (EUVI). The three-dimensional loop geometry is determined using a three-dimensional reconstruction with a semicircular loop model, which allows for an accurate measurement of the loop length. The plane of wave polarization is found from comparison with a simulated loop model and shows that the oscillation is a fundamental horizontally polarized fast magnetoacoustic kink mode. The oscillation is characterized using an automated method and the results from both spacecraft are found to match closely. The oscillation period is 630 ± 30 s and the damping time is 1000 ± 300 s. Also, clear intensity variations associated with the transverse loop oscillations are reported for the first time. They are shown to be caused by the effect of line-of-sight integration. The Alfven speed and coronal magnetic field derived using coronal seismology are discussed. This study shows that EUVI/STEREO observations achieve an adequate accuracy for studying long-period, large-amplitude transverse loop oscillations.

  17. Witnessing a Large-scale Slipping Magnetic Reconnection along a Dimming Channel during a Solar Flare

    Energy Technology Data Exchange (ETDEWEB)

    Jing, Ju; Lee, Jeongwoo; Xu, Yan; Liu, Chang; Wang, Haimin [Center for Solar-Terrestrial Research, New Jersey Institute of Technology, Newark, NJ 07102-1982 (United States); Liu, Rui [CAS Key Laboratory of Geospace Environment, Department of Geophysics and Planetary Sciences, University of Science and Technology of China, Hefei 230026 (China); Cheung, Mark C. M. [Lockheed Martin Solar and Astrophysics Laboratory, Palo Alto, CA 94304 (United States); Zhu, Chunming, E-mail: ju.jing@njit.edu [Department of Physics, Montana State University, Bozeman, MT 59717 (United States)

    2017-06-20

    We report the intriguing large-scale dynamic phenomena associated with the M6.5 flare (SOL2015-06-22T18:23) in NOAA active region 12371, observed by RHESSI , Fermi , and the Atmospheric Image Assembly (AIA) and Magnetic Imager (HMI) on the Solar Dynamics Observatory ( SDO ). The most interesting feature of this event is a third ribbon (R3) arising in the decay phase, propagating along a dimming channel (seen in EUV passbands) toward a neighboring sunspot. The propagation of R3 occurs in the presence of hard X-ray footpoint emission and is broadly visible at temperatures from 0.6 MK to over 10 MK through the differential emission measure analysis. The coronal loops then undergo an apparent slipping motion following the same path of R3, after a ∼80 minute delay. To understand the underlying physics, we investigate the magnetic configuration and the thermal structure of the flaring region. Our results are in favor of a slipping-type reconnection followed by the thermodynamic evolution of coronal loops. In comparison with those previously reported slipping reconnection events, this one proceeds across a particularly long distance (∼60 Mm) over a long period of time (∼50 minutes) and shows two clearly distinguished phases: the propagation of the footpoint brightening driven by nonthermal particle injection and the apparent slippage of loops governed by plasma heating and subsequent cooling.

  18. Design, construction, and measurement of a large solar powered thermoacoustic cooler

    Science.gov (United States)

    Chen, Reh-Lin

    2001-07-01

    A device based on harnessing concentrated solar power in combination with using thermoacoustic principles has been built, instrumented, and tested. Its acoustic power is generated by solar radiation and is subsequently used to pump heat from external loads. The direct conversion between thermal and mechanical energy without going through any electronic stage makes the mechanism simple. Construction of the solar collector is also rather unsophisticated. It was converted from a 10-ft satellite dish with aluminized Mylar glued on the surface. The thermoacoustic device was mounted on the dish with its engine's hot side positioned near the focus of the parabolic dish, about 1 meter above the center of the dish. A 2-dimensional solar tracking system was built, using two servo motors to position the dish at pre-calculated coordinates. The solar powered thermoacoustic cooler is intended to be used where solar power is abundant and electricity may not be available or reliable. The cooler provides cooling during solar availability. Cooling can be maintained by the latent heat of ice when solar power is unattainable. The device has achieved cooling although compromised by gas leakage and thermal losses and was not able to provide temperatures low enough to freeze water. Improvements of the device are expected through modifications suggested herein.

  19. Plasma texturing on large-area industrial grade CZ silicon solar cells

    DEFF Research Database (Denmark)

    Davidsen, Rasmus Schmidt; Nordseth, Ørnulf; Schmidt, Michael Stenbæk

    2013-01-01

    We report on an experimental study of nanostructuring of silicon solar cells using reactive ion etching (RIE). A simple mask-less, scalable RIE nanostructuring of the solar cell surface is shown to reduce the AM1.5-weighted average reflectance to a level below 1 % in a fully optimized RIE texturi...

  20. Community challenges when using large plastic bottles for Solar Energy Disinfection of Water (SODIS

    Directory of Open Access Journals (Sweden)

    Preeti Borde

    2016-09-01

    Full Text Available Abstract Background Communities living in developing countries as well as populations affected by natural or man-made disasters can be left at great risk from water related diseases, especially those spread through the faecal-oral route. Conventional water treatments such as boiling and chlorination can be effective but may prove costly for impoverished communities. Solar water disinfection (SODIS has been shown to be a cheap and effective way for communities to treat their water. The exposure to sunlight is typically carried out in small volume plastic beverage bottles (up to 2 l. Given the water requirements of consumption and basic personal hygiene, this may not always meet the needs of communities. Recent work has shown 19-L plastic water dispenser containers to be effective SODIS reactors, comparable in efficacy to PET bottles. In this paper we outline the need for studying SODIS in large volumes and discuss 4 main associated challenges. Discussion Apart from clean water needed for consumption, access to adequate water is essential for sanitation and hygiene. Contamination of treated water through unwashed hands or vessels contributes heavily to the spread of water borne pathogens in communities. Traditional water treatments such as boiling and chlorination can be effective but may prove financially burdensome for low income communities. SODIS in large vessels could be used as a simple method to meet water requirements in low income and disaster affected populations. However, there have been some concerns associated with the conventional SODIS method; we identify the main ones to be: (1 cold or cloudy weather; (2 the fear of leaching in plastic bottles; (3 water turbidity, and; (4 community acceptance. Summary The application of SODIS in large bottles like WDCs has the potential to be an efficient and cost effective method of disinfecting water, either for consumption until more rigorous water treatments can be put in place, or for

  1. Lightning Surge Analysis on a Large Scale Grid-Connected Solar Photovoltaic System

    Directory of Open Access Journals (Sweden)

    Nur Hazirah Zaini

    2017-12-01

    Full Text Available Solar photovoltaic (PV farms currently play a vital role in the generation of electrical power in different countries, such as Malaysia, which is moving toward the use of renewable energy. Malaysia is one of the countries with abundant sunlight and thus can use solar PV farms as alternative sources for electricity generation. However, lightning strikes frequently occur in the country. Being installed in open and flat areas, solar PV farms, especially their electronic components, are at great risk of damage caused by lightning. In this paper, the effects of lightning currents with different peak currents and waveshapes on grid-connected solar PV farms were determined to approximate the level of transient effect that can damage solar PV modules, inverters and transformers. Depending on the location of the solar PV farm, engineer can obtain information on the peak current and median current of the site from the lightning location system (LLS and utilise the results obtained in this study to appropriately assign an SPD to protect the solar panel, inverter and the main panel that connected to the grid. Therefore, the simulation results serve as the basis for controlling the effects of lightning strikes on electrical equipment and power grids where it provides proper justification on the ‘where to be installed’ and ‘what is the rating’ of the SPD. This judgment and decision will surely reduce the expensive cost of repair and replacement of electrical equipment damages due to the lightning.

  2. Development and validation of a detailed TRNSYS-Matlab model for large solar collector fields for district heating applications

    DEFF Research Database (Denmark)

    Bava, Federico; Furbo, Simon

    2017-01-01

    This study describes the development of a detailed TRNSYS-Matlab model to simulate the behavior of a large solar collector field for district heating application. The model includes and investigates aspects which are not always considered by simpler models, such as flow distribution...... programming and computing time. Thermal capacity was worth being considered only for the bulkier components, such as the longer distribution and transmission pipes. The actual control strategy, which regulates the flow rates in the solar heating plant, was accurately reproduced in the model, as proved...... in the different rows, effect of the flow regime on the collector efficiency, thermal capacity of the components and effect of shadows from row to row. The model was compared with measurements from a solar collector field and the impact of each aspect was evaluated. A good agreement between model and measurements...

  3. Complex active regions as the main source of extreme and large solar proton events

    Science.gov (United States)

    Ishkov, V. N.

    2013-12-01

    A study of solar proton sources indicated that solar flare events responsible for ≥2000 pfu proton fluxes mostly occur in complex active regions (CARs), i.e., in transition structures between active regions and activity complexes. Different classes of similar structures and their relation to solar proton events (SPEs) and evolution, depending on the origination conditions, are considered. Arguments in favor of the fact that sunspot groups with extreme dimensions are CARs are presented. An analysis of the flare activity in a CAR resulted in the detection of "physical" boundaries, which separate magnetic structures of the same polarity and are responsible for the independent development of each structure.

  4. Pioneer and Voyager observations of the solar wind at large heliocentric distances and latitudes

    Science.gov (United States)

    Gazis, P. R.; Mihalov, J. D.; Barnes, A.; Lazarus, A. J.; Smith, E. J.

    1989-01-01

    Data obtained from the electrostatic analyzers aboard the Pioneer 10 and 11 spacecraft and from the Faraday cup aboard Voyager 2 were used to study spatial gradients in the distant solar wind. Prior to mid-1985, both spacecraft observed nearly identical solar wind structures. After day 150 of 1985, the velocity structure at Voyager 2 became flatter, and the Voyager 2 velocities were smaller than those observed by Pioneer 11. It is suggested that these changes in the solar wind at low latitudes may be related to a change which occurred in the coronal hole structure in early 1985.

  5. Simultaneous Solar Maximum Mission and Very Large Array (VLA) observations of solar active regions. Semiannual Progress Report, 1 February 1985-30 January 1986

    International Nuclear Information System (INIS)

    Lang, K.R.

    1985-08-01

    Simultaneous observations of solar active regions with the Solar Maximum Mission (SMM) Satellite and the Very Large Array (VLA) have been obtained and analyzed. Combined results enhance the scientific return for beyond that expeted from using either SMM or VLA alone. A total of two weeks of simultaneous SMM/VLA data were obtained. The multiple wavelength VLA observations were used to determine the temperature and magnetic structure at different heights within coronal loops. These data are compared with simultaneous SMM observations. Several papers on the subject are in progress. They include VLA observations of compact, transient sources in the transition region; simultaneous SMM/VLA observations of the coronal loops in one active region and the evolution of another one; and sampling of the coronal plasma using thermal cyclotron lines (magnetic field - VLA) and soft X ray spectral lines (electron density and electron temperaure-SMM)

  6. Solar wind stream evolution at large heliocentric distances - Experimental demonstration and the test of a model

    Science.gov (United States)

    Gosling, J. T.; Hundhausen, A. J.; Bame, S. J.

    1976-01-01

    A stream propagation model which neglects all dissipation effects except those occurring at shock interfaces, was used to compare Pioneer-10 solar wind speed observations, during the time when Pioneer 10, the earth, and the sun were coaligned, with near-earth Imp-7 observations of the solar wind structure, and with the theoretical predictions of the solar wind structure at Pioneer 10 derived from the Imp-7 measurements, using the model. The comparison provides a graphic illustration of the phenomenon of stream steepening in the solar wind with the attendant formation of forward-reverse shock pairs and the gradual decay of stream amplitudes with increasing heliocentric distance. The comparison also provides a qualitative test of the stream propagation model.

  7. Top Five Large-Scale Solar Myths | State, Local, and Tribal Governments |

    Science.gov (United States)

    shadow on neighboring properties, cause light flicker, or have the same visual impact as wind farms), the . Some communities have opted for mitigation measures to reduce visual impacts of solar farms through the

  8. Solar cosmic ray events at large radial distances from the sun

    International Nuclear Information System (INIS)

    Zwickl, R.; Webber, W.R.; McDonald, F.B.; Teegarden, B.; Trainor, J.

    1975-01-01

    Using the GSFC-UNH cosmic ray telescope on Pioneer 10 and 11 we have examined solar cosmic ray events out to a distance approximately 5 AU from the sun. Here we consider two aspects of this work, both related to our anisotropy studies. First, a detailed error analysis of the cosine fit to the anisotropy is presented. Second, we look at the anisotropy and intensity time characteristics during solar events as a function of radial distance. (orig.) [de

  9. Variability of Power from Large-Scale Solar Photovoltaic Scenarios in the State of Gujarat: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Parsons, B.; Hummon, M.; Cochran, J.; Stoltenberg, B.; Batra, P.; Mehta, B.; Patel, D.

    2014-04-01

    India has ambitious goals for high utilization of variable renewable power from wind and solar, and deployment has been proceeding at a rapid pace. The western state of Gujarat currently has the largest amount of solar generation of any Indian state, with over 855 Megawatts direct current (MWDC). Combined with over 3,240 MW of wind, variable generation renewables comprise nearly 18% of the electric-generating capacity in the state. A new historic 10-kilometer (km) gridded solar radiation data set capturing hourly insolation values for 2002-2011 is available for India. We apply an established method for downscaling hourly irradiance data to one-minute irradiance data at potential PV power production locations for one year, 2006. The objective of this report is to characterize the intra-hour variability of existing and planned photovoltaic solar power generation in the state of Gujarat (a total of 1.9 gigawatts direct current (GWDC)), and of five possible expansion scenarios of solar generation that reflect a range of geographic diversity (each scenario totals 500-1,000 MW of additional solar capacity). The report statistically analyzes one year's worth of power variability data, applied to both the baseline and expansion scenarios, to evaluate diurnal and seasonal power fluctuations, different timescales of variability (e.g., from one to 15 minutes), the magnitude of variability (both total megawatts and relative to installed solar capacity), and the extent to which the variability can be anticipated in advance. The paper also examines how Gujarat Energy Transmission Corporation (GETCO) and the Gujarat State Load Dispatch Centre (SLDC) could make use of the solar variability profiles in grid operations and planning.

  10. Large-size deployable construction heated by solar irradiation in free space

    Science.gov (United States)

    Pestrenina, Irena; Kondyurin, Alexey; Pestrenin, Valery; Kashin, Nickolay; Naymushin, Alexey

    Large-size deployable construction in free space with subsequent direct curing was invented more than fifteen years ago (Briskman et al., 1997 and Kondyurin, 1998). It caused a lot of scientific problems, one of which is a possibility to use the solar energy for initiation of the curing reaction. This paper is devoted to investigate the curing process under sun irradiation during a space flight in Earth orbits. A rotation of the construction is considered. This motion can provide an optimal temperature distribution in the construction that is required for the polymerization reaction. The cylindrical construction of 80 m length with two hemispherical ends of 10 m radius is considered. The wall of the construction of 10 mm carbon fibers/epoxy matrix composite is irradiated by heat flux from the sun and radiates heat from the external surface by the Stefan- Boltzmann law. A stage of polymerization reaction is calculated as a function of temperature/time based on the laboratory experiments with certified composite materials for space exploitation. The curing kinetics of the composite is calculated for different inclination Low Earth Orbits (300 km altitude) and Geostationary Earth Orbit (40000 km altitude). The results show that • the curing process depends strongly on the Earth orbit and the rotation of the construction; • the optimal flight orbit and rotation can be found to provide the thermal regime that is sufficient for the complete curing of the considered construction. The study is supported by RFBR grant No.12-08-00970-a. 1. Briskman V., A.Kondyurin, K.Kostarev, V.Leontyev, M.Levkovich, A.Mashinsky, G.Nechitailo, T.Yudina, Polymerization in microgravity as a new process in space technology, Paper No IAA-97-IAA.12.1.07, 48th International Astronautical Congress, October 6-10, 1997, Turin Italy. 2. Kondyurin A.V., Building the shells of large space stations by the polymerisation of epoxy composites in open space, Int. Polymer Sci. and Technol., v.25, N4

  11. Dose uncertainties for large solar particle events: Input spectra variability and human geometry approximations

    International Nuclear Information System (INIS)

    Townsend, Lawrence W.; Zapp, E. Neal

    1999-01-01

    The true uncertainties in estimates of body organ absorbed dose and dose equivalent, from exposures of interplanetary astronauts to large solar particle events (SPEs), are essentially unknown. Variations in models used to parameterize SPE proton spectra for input into space radiation transport and shielding computer codes can result in uncertainty about the reliability of dose predictions for these events. Also, different radiation transport codes and their input databases can yield significant differences in dose predictions, even for the same input spectra. Different results may also be obtained for the same input spectra and transport codes if different spacecraft and body self-shielding distributions are assumed. Heretofore there have been no systematic investigations of the variations in dose and dose equivalent resulting from these assumptions and models. In this work we present a study of the variability in predictions of organ dose and dose equivalent arising from the use of different parameters to represent the same incident SPE proton data and from the use of equivalent sphere approximations to represent human body geometry. The study uses the BRYNTRN space radiation transport code to calculate dose and dose equivalent for the skin, ocular lens and bone marrow using the October 1989 SPE as a model event. Comparisons of organ dose and dose equivalent, obtained with a realistic human geometry model and with the oft-used equivalent sphere approximation, are also made. It is demonstrated that variations of 30-40% in organ dose and dose equivalent are obtained for slight variations in spectral fitting parameters obtained when various data points are included or excluded from the fitting procedure. It is further demonstrated that extrapolating spectra from low energy (≤30 MeV) proton fluence measurements, rather than using fluence data extending out to 100 MeV results in dose and dose equivalent predictions that are underestimated by factors as large as 2

  12. Gingival zenith and its role in redefining esthetics: A clinical study

    Directory of Open Access Journals (Sweden)

    Babita Pawar

    2011-01-01

    Full Text Available Background: The purpose of this study was to quantify some clinical parameters useful as esthetic guidelines when gingival contour is modified and to compare the left and right sides of six maxillary anterior teeth. Materials and Methods: Maxillary casts mounted on an articulator according to the axis orbital plane were photographed from 35 young adults. The angle formed between the gingival line and maxillary midline (GLA and the distance between the gingival zenith of the lateral incisor and the gingival line were measured (LID using a flexible protractor and digital vernier caliper, respectively. The asymmetry was evaluated using a paired t test for the left vs right measurements of GLA and LID. The descriptive statistics for GLA and LID were calculated. Results: The GLA measurements of the left side (86.7΀΁4.2΀ were significantly greater than those of the right side (84.6΀΁5.4΀, and the mean absolute symmetry for GLA was 1.7΀΁4.4΀. The mean LID measurement was 0.92΁0.11. Conclusions: The gingival zenith of the canine is apical to the gingival zenith of the incisors (GLA <90΀ and the gingival zenith of the lateral incisor is below or on (17% the gingival line when head is oriented on the axis orbital plane. A directional asymmetry was shown with the right side higher than the left side. Along with the other parameters related to dental esthetics, these clinical parameters may serve as esthetic guidelines and may enable us to obtain a more predictable outcome.

  13. Reactivity and reaction rate studies on the fourth loading of ZENITH

    International Nuclear Information System (INIS)

    Cameron, I.R.; Freemantle, R.G.; Reed, D.L.; Wilson, D.J.

    1963-08-01

    The determination of the excess reactivity, control rod worths, prompt neutron lifetime, flux fine structure, and reaction rates of various nuclides for the fourth loading of the heated zero energy reactor ZENITH is described. The core contains 7.76 kg of U235, giving a carbon/U235 atom ratio of 7578, and forms the most dilute of the range studied. Comparisons of the experimental results with calculations using multigroup diffusion codes are presented. (author)

  14. Reactivity and reaction rate studies on the fourth loading of ZENITH

    Energy Technology Data Exchange (ETDEWEB)

    Cameron, I R; Freemantle, R G; Reed, D L; Wilson, D J [General Reactor Physics Division, Atomic Energy Establishment, Winfrith, Dorchester, Dorset (United Kingdom)

    1963-08-15

    The determination of the excess reactivity, control rod worths, prompt neutron lifetime, flux fine structure, and reaction rates of various nuclides for the fourth loading of the heated zero energy reactor ZENITH is described. The core contains 7.76 kg of U235, giving a carbon/U235 atom ratio of 7578, and forms the most dilute of the range studied. Comparisons of the experimental results with calculations using multigroup diffusion codes are presented. (author)

  15. Validation of real-time zenith tropospheric delay estimation with TOMION software within WAGNSS networks

    OpenAIRE

    Graffigna, Victoria

    2017-01-01

    The TOmographic Model of the IONospheric electron content (TOMION) software implements a simultaneous precise geodetic and ionospheric modeling, which can be used to test new approaches for real-time precise GNSS modeling (positioning, ionospheric and tropospheric delays, clock errors, among others). In this work, the software is used to estimate the Zenith Tropospheric Delay (ZTD) emulating real time and its performance is evaluated through a comparative analysis with a built-in GIPSY estima...

  16. Production of large-area polymer solar cells by industrial silk screen printing, lifetime considerations and lamination with polyethyleneterephthalate

    DEFF Research Database (Denmark)

    Krebs, Frederik C; Alstrup, J.; Spanggaard, H.

    2004-01-01

    The possibility of making large area (100 cm(2)) polymer solar cells based on the conjugated polymer poly 1,4-(2-methoxy-5-ethylhexyloxy)phenylenevinylene (MEH-PPV) was demonstrated. Devices were prepared by etching an electrode pattern on ITO covered polyethyleneterephthalate (PET) substrates....... A pattern of conducting silver epoxy allowing for electrical contacts to the device was silk screen printed and hardened. Subsequently a pattern of MEH-PPV was silk screen printed in registry with the ITO electrode pattern on top of the substrate. Final evaporation of an aluminum electrode or sublimation......). The half-life based on I-sc in air for the devices were 63 h. The cells were laminated in a 125 mum PET encasement. Lamination had a negative effect on the lifetime. We demonstrate the feasibility of industrial production of large area solar cells (1 m(2)) by silk screen printing and envisage...

  17. Research Update: Large-area deposition, coating, printing, and processing techniques for the upscaling of perovskite solar cell technology

    Directory of Open Access Journals (Sweden)

    Stefano Razza

    2016-09-01

    Full Text Available To bring perovskite solar cells to the industrial world, performance must be maintained at the photovoltaic module scale. Here we present large-area manufacturing and processing options applicable to large-area cells and modules. Printing and coating techniques, such as blade coating, slot-die coating, spray coating, screen printing, inkjet printing, and gravure printing (as alternatives to spin coating, as well as vacuum or vapor based deposition and laser patterning techniques are being developed for an effective scale-up of the technology. The latter also enables the manufacture of solar modules on flexible substrates, an option beneficial for many applications and for roll-to-roll production.

  18. Large area flexible polymer solar cells with high efficiency enabled by imprinted Ag grid and modified buffer layer

    International Nuclear Information System (INIS)

    Lu, Shudi; Lin, Jie; Liu, Kong; Yue, Shizhong; Ren, Kuankuan; Tan, Furui; Wang, Zhijie; Jin, Peng; Qu, Shengchun; Wang, Zhanguo

    2017-01-01

    To take a full advantage of polymer semiconductors on realization of large-area flexible photovoltaic devices, herein, we fabricate polymer solar cells on the basis of polyethylene terephthalate (PET) with imprinted Ag grid as transparent electrode. The key fabrication procedure is the adoption of a modified PEDOT:PSS (PH1000) solution for spin-coating the buffer layer to form a compact contact with the substrate. In comparison with the devices with intrinsic PEDOT:PSS buffer layer, the advanced devices present a much higher efficiency of 6.51%, even in a large device area of 2.25 cm"2. Subsequent characterizations reveal that such devices show an impressive performance stability as the bending angle is enlarged to 180° and bending time is up to 1000 cycles. Not only providing a general methodology to construct high efficient and flexible polymer solar cells, this paper also involves deep insights on device working mechanism in bending conditions.

  19. Evidence of L-mode electromagnetic wave pumping of ionospheric plasma near geomagnetic zenith

    Directory of Open Access Journals (Sweden)

    T. B. Leyser

    2018-02-01

    Full Text Available The response of ionospheric plasma to pumping by powerful HF (high frequency electromagnetic waves transmitted from the ground into the ionosphere is the strongest in the direction of geomagnetic zenith. We present experimental results from transmitting a left-handed circularly polarized HF beam from the EISCAT (European Incoherent SCATter association Heating facility in magnetic zenith. The CASSIOPE (CAScade, Smallsat and IOnospheric Polar Explorer spacecraft in the topside ionosphere above the F-region density peak detected transionospheric pump radiation, although the pump frequency was below the maximum ionospheric plasma frequency. The pump wave is deduced to arrive at CASSIOPE through L-mode propagation and associated double (O to Z, Z to O conversion in pump-induced radio windows. L-mode propagation allows the pump wave to reach higher plasma densities and higher ionospheric altitudes than O-mode propagation so that a pump wave in the L-mode can facilitate excitation of upper hybrid phenomena localized in density depletions in a larger altitude range. L-mode propagation is therefore suggested to be important in explaining the magnetic zenith effect.

  20. Synthesis of zinc phthalocyanine with large steric hindrance and its photovoltaic performance for dye-sensitized solar cells.

    Science.gov (United States)

    Lin, Li; Peng, Bosi; Shi, Wenye; Guo, Yingying; Li, Renjie

    2015-03-28

    A zinc phthalocyanine (ZnPc) derivative (Zn-tri-PcNc-8) containing tri-benzonaphtho-condensed porphyrazine with one carboxylic and six diphenylphenoxy peripheral substitutions was designed and synthesized as a sensitizer for dye-sensitized solar cells (DSSCs). For the purpose of extending the absorption spectra while minimizing the formation of ZnPc molecular aggregates, bulky 2,6-diphenylphenoxy groups were used as electron donor moieties, and the carboxylic group as an anchoring group to graft the sensitizer onto the semiconductor. It was found that a TiO2-based solar cell sensitized by Zn-tri-PcNc-8 shows a maximum incident photon-to-current conversion efficiency in the red/near-IR light range (650-750 nm), and a solar cell sensitized at near room temperature (30 °C) for 48 h exhibits the best efficiency (3.01%). The efficiency was much higher than that (1.96%) for a solar cell sensitized by its analogue (Zn-tri-PcNc-2) having one carboxyl and three tert-butyl groups without chenodeoxycholic acid (CDCA), indicating that the introduction of six bulky diphenylphenoxy substitutions with large steric hindrance in the ZnPc macrocycle can effectively suppress the molecular aggregates, thus resulting in an improved conversion efficiency. The present results shed light on an effective solution to adjust the ZnPc property via chemical modification such as changing the "push-pull" effect and adding large steric hindrance substituents to further improve the efficiency of the phthalocyanine-sensitized solar cell.

  1. Application of CBD-Zinc Sulfide Film as an Antireflection Coating on Very Large Area Multicrystalline Silicon Solar Cell

    Directory of Open Access Journals (Sweden)

    U. Gangopadhyay

    2007-01-01

    Full Text Available The low-cost chemical bath deposition (CBD technique is used to prepare CBD-ZnS films as antireflective (AR coating for multicrystalline silicon solar cells. The uniformity of CBD-ZnS film on large area of textured multicrystalline silicon surface is the major challenge of CBD technique. In the present work, attempts have been made for the first time to improve the rate of deposition and uniformity of deposited film by controlling film stoichiometry and refractive index and also to minimize reflection loss by proper optimization of molar percentage of different chemical constituents and deposition conditions. Reasonable values of film deposition rate (12.13 Å′/min., good film uniformity (standard deviation <1, and refractive index (2.35 along with a low percentage of average reflection (6-7% on a textured mc-Si surface are achieved with proper optimization of ZnS bath. 12.24% efficiency on large area (125 mm × 125 mm multicrystalline silicon solar cells with CBD-ZnS antireflection coating has been successfully fabricated. The viability of low-cost CBD-ZnS antireflection coating on large area multicrystalline silicon solar cell in the industrial production level is emphasized.

  2. Process parameter impact on properties of sputtered large-area Mo bilayers for CIGS thin film solar cell applications

    Energy Technology Data Exchange (ETDEWEB)

    Badgujar, Amol C.; Dhage, Sanjay R., E-mail: dhage@arci.res.in; Joshi, Shrikant V.

    2015-08-31

    Copper indium gallium selenide (CIGS) has emerged as a promising candidate for thin film solar cells, with efficiencies approaching those of silicon-based solar cells. To achieve optimum performance in CIGS solar cells, uniform, conductive, stress-free, well-adherent, reflective, crystalline molybdenum (Mo) thin films with preferred orientation (110) are desirable as a back contact on large area glass substrates. The present study focuses on cylindrical rotating DC magnetron sputtered bilayer Mo thin films on 300 mm × 300 mm soda lime glass (SLG) substrates. Key sputtering variables, namely power and Ar gas flow rates, were optimized to achieve best structural, electrical and optical properties. The Mo films were comprehensively characterized and found to possess high degree of thickness uniformity over large area. Best crystallinity, reflectance and sheet resistance was obtained at high sputtering powers and low argon gas flow rates, while mechanical properties like adhesion and residual stress were found to be best at low sputtering power and high argon gas flow rate, thereby indicating a need to arrive at a suitable trade-off during processing. - Highlights: • Sputtering of bilayer molybdenum thin films on soda lime glass • Large area deposition using rotating cylindrical direct current magnetron • Trade of sputter process parameters power and pressure • High uniformity of thickness and best electrical properties obtained • Suitable mechanical and optical properties of molybdenum are achieved for CIGS application.

  3. Low-Temperature Soft-Cover Deposition of Uniform Large-Scale Perovskite Films for High-Performance Solar Cells.

    Science.gov (United States)

    Ye, Fei; Tang, Wentao; Xie, Fengxian; Yin, Maoshu; He, Jinjin; Wang, Yanbo; Chen, Han; Qiang, Yinghuai; Yang, Xudong; Han, Liyuan

    2017-09-01

    Large-scale high-quality perovskite thin films are crucial to produce high-performance perovskite solar cells. However, for perovskite films fabricated by solvent-rich processes, film uniformity can be prevented by convection during thermal evaporation of the solvent. Here, a scalable low-temperature soft-cover deposition (LT-SCD) method is presented, where the thermal convection-induced defects in perovskite films are eliminated through a strategy of surface tension relaxation. Compact, homogeneous, and convection-induced-defects-free perovskite films are obtained on an area of 12 cm 2 , which enables a power conversion efficiency (PCE) of 15.5% on a solar cell with an area of 5 cm 2 . This is the highest efficiency at this large cell area. A PCE of 15.3% is also obtained on a flexible perovskite solar cell deposited on the polyethylene terephthalate substrate owing to the advantage of presented low-temperature processing. Hence, the present LT-SCD technology provides a new non-spin-coating route to the deposition of large-area uniform perovskite films for both rigid and flexible perovskite devices. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. The solar elemental abundances problem: Large enhancements in photoionization and bound-free opacity

    Science.gov (United States)

    Pradhan, A.; Nahar, S.

    2016-05-01

    Aimed at solving the outstanding problem of solar opacity and radiation transport, we report substantial photoabsorption in the high-energy regime due to atomic core photo-excitations not heretofore considered. In an extensive R-Matrix calculations of unprecedented complexity for an important iron ion Fe XVII, with a wave function expansion of 99 Fe XVIII core states from n current opacity models, and ii) demonstrate convergence with respect to successive core excitations. These findings may explain the ``higher-than-predicted'' monochromatic iron opacity measured recently at the Sandia Z-pinch fusion device at solar interior conditions. The findings will also impact the total atomic photoabsorption and radiation transport in laboratory and astrophysical plasmas, such as UV emission from host stars of extra-solar planets. Support: NSF, DOE, Ohio Supercomputer Center, Columbus, OH.

  5. Large scale deployment of polymer solar cells on land, on sea and in the air

    DEFF Research Database (Denmark)

    Espinosa Martinez, Nieves; Hösel, Markus; Jørgensen, Mikkel

    2014-01-01

    With the development of patterns that connect all cells in series, organic photovoltaics have leapt a step forward being ahead of other solar and even other energy technologies in terms of manufacturing speed and energy density. The important questions of how they are meant to be installed...... for producing power and what the requirements are yet to be explored. We present here the installation of organic solar cell modules in different settings (terrestrial, marine and airborne). For the evaluation of these installations deployed at DTU, we have used the life cycle assessment tools, and calculated...... key parameters in order to assess their environmental impact. The novel technology when installed in a solar park system can generate more than 1300 kW h kWp-1 of electricity a year, which means that the whole system can pay the energy invested back before the first year of operation, in 320 days...

  6. Reconstruction of a large-scale reconnection exhaust structure in the solar wind

    Directory of Open Access Journals (Sweden)

    W.-L. Teh

    2009-02-01

    Full Text Available We recover two-dimensional (2-D magnetic field and flow field configurations from three spacecraft encounters with a single large-scale reconnection exhaust structure in the solar wind, using a new reconstruction method (Sonnerup and Teh, 2008 based on the ideal single-fluid MHD equations in a steady-state, 2-D geometry. The reconstruction is performed in the rest frame of the X-line, where the flow into, and the plasma jetting within, the exhaust region are clearly visible. The event was first identified by Phan et al. (2006 in the ACE, Cluster, and Wind data sets; they argued that quasi-steady reconnection persisted for over 2 h at a long (390 RE X-line. The reconnection exhaust is sandwiched between two discontinuities, both of which contain elements of intermediate- and slow-mode behavior; these elements are co-located rather than being spatially separated. These composite discontinuities do not satisfy the coplanarity condition or the standard MHD jump conditions. For all three spacecraft, the Walén regression line slope was positive (negative for the leading (trailing discontinuity. Our MHD reconstruction shows that: (1 the X-line orientation was close to the bisector of the overall magnetic shear angle and exhibited a slow rotating motion toward the Sun-Earth line; (2 the X-line moved earthward, dawnward, and southward; (3 the reconnection electric field was small (~0.02 mV/m on average and gradually decreased from the first crossing (ACE to the last (Wind. The magnetic field and flow field configurations recovered from ACE and Cluster are similar while those recovered from Wind also include a magnetic island and an associated vortex. Reconnection persisted for at least 2.4 h involving inflow into the exhaust region from its two sides. Time-dependence in the reconnection electric fields seen by ACE and Wind indicates local temporal variations in the field configuration. In addition to the reconstruction results, we

  7. Reconstruction of a large-scale reconnection exhaust structure in the solar wind

    International Nuclear Information System (INIS)

    Teh, W.L.; Sonnerup, B.U.Oe.; Hu, Q.; Farrugia, C.J.

    2009-01-01

    We recover two-dimensional (2-D) magnetic field and flow field configurations from three spacecraft encounters with a single large-scale reconnection exhaust structure in the solar wind, using a new reconstruction method (Sonnerup and Teh, 2008) based on the ideal single-fluid MHD equations in a steady-state, 2-D geometry. The reconstruction is performed in the rest frame of the X-line, where the flow into, and the plasma jetting within, the exhaust region are clearly visible. The event was first identified by Phan et al. (2006) in the ACE, Cluster, and Wind data sets; they argued that quasi-steady reconnection persisted for over 2 h at a long (390 R E ) X-line. The reconnection exhaust is sandwiched between two discontinuities, both of which contain elements of intermediate- and slow-mode behavior; these elements are co-located rather than being spatially separated. These composite discontinuities do not satisfy the coplanarity condition or the standard MHD jump conditions. For all three spacecraft, the Walen regression line slope was positive (negative) for the leading (trailing) discontinuity. Our MHD reconstruction shows that: (1) the X-line orientation was close to the bisector of the overall magnetic shear angle and exhibited a slow rotating motion toward the Sun-Earth line; (2) the X-line moved earthward, dawnward, and southward; (3) the reconnection electric field was small (∝0.02 mV/m on average) and gradually decreased from the first crossing (ACE) to the last (Wind). The magnetic field and flow field configurations recovered from ACE and Cluster are similar while those recovered from Wind also include a magnetic island and an associated vortex. Reconnection persisted for at least 2.4 h involving inflow into the exhaust region from its two sides. Time-dependence in the reconnection electric fields seen by ACE and Wind indicates local temporal variations in the field configuration. In addition to the reconstruction results, we provide a description and

  8. Reconstruction of a large-scale reconnection exhaust structure in the solar wind

    Directory of Open Access Journals (Sweden)

    W.-L. Teh

    2009-02-01

    Full Text Available We recover two-dimensional (2-D magnetic field and flow field configurations from three spacecraft encounters with a single large-scale reconnection exhaust structure in the solar wind, using a new reconstruction method (Sonnerup and Teh, 2008 based on the ideal single-fluid MHD equations in a steady-state, 2-D geometry. The reconstruction is performed in the rest frame of the X-line, where the flow into, and the plasma jetting within, the exhaust region are clearly visible. The event was first identified by Phan et al. (2006 in the ACE, Cluster, and Wind data sets; they argued that quasi-steady reconnection persisted for over 2 h at a long (390 RE X-line. The reconnection exhaust is sandwiched between two discontinuities, both of which contain elements of intermediate- and slow-mode behavior; these elements are co-located rather than being spatially separated. These composite discontinuities do not satisfy the coplanarity condition or the standard MHD jump conditions. For all three spacecraft, the Walén regression line slope was positive (negative for the leading (trailing discontinuity. Our MHD reconstruction shows that: (1 the X-line orientation was close to the bisector of the overall magnetic shear angle and exhibited a slow rotating motion toward the Sun-Earth line; (2 the X-line moved earthward, dawnward, and southward; (3 the reconnection electric field was small (~0.02 mV/m on average and gradually decreased from the first crossing (ACE to the last (Wind. The magnetic field and flow field configurations recovered from ACE and Cluster are similar while those recovered from Wind also include a magnetic island and an associated vortex. Reconnection persisted for at least 2.4 h involving inflow into the exhaust region from its two sides. Time-dependence in the reconnection electric fields seen by ACE and Wind indicates local temporal variations in the field configuration. In addition to the reconstruction results, we provide a description

  9. Properties of solar proton events at large heliocentric distances near ecliptic

    International Nuclear Information System (INIS)

    Khiber, B.; Struminskij, A.B.

    2005-01-01

    The absolute intensities, fluences and propagation times of the solar protons with the energy of 38-125 MeV, obtained on the basis of the observation data of the Kilskij electron telescope (KET ULYSSES) onboard the ULYSSES cosmic apparatus and GOES proton detector, are compared. The observation data on the solar cosmic rays at the heliocentric distances above 5 a.e. are analyzed for the first time. Certain characteristics of the proton events under consideration and their possible parent flares are presented [ru

  10. Optimizations of large area quasi-solid-state dye-sensitized solar cells

    DEFF Research Database (Denmark)

    Biancardo, M.; West, K.; Krebs, Frederik C

    2006-01-01

    In this paper, we address optimizations of dye sensitized solar cells (DSSCs) through the combination of important issues like semi-transparency, quasi-solid-state constructions and low-cost realization of serially connected modules. DSSCs with a transparency of 50% in the visible region, moderate...... encouraging results. A short circuit current (I-sc) of 4.45 mA cm(-2) with an open circuit voltage (V-oc) of 0.5 V were recorded in standard solar cells sensitized by cis-bis(thiocyano) ruthenium(II)-bis-2, 2'-bipyridine-4, 4'-dicarboxylate. Up-scaling tests demonstrate the easy realization of a 625 cm(2...

  11. Tropospheric nitrogen dioxide column retrieval based on ground-based zenith-sky DOAS observations

    Science.gov (United States)

    Tack, F. M.; Hendrick, F.; Pinardi, G.; Fayt, C.; Van Roozendael, M.

    2013-12-01

    A retrieval approach has been developed to derive tropospheric NO2 vertical column amounts from ground-based zenith-sky measurements of scattered sunlight. Zenith radiance spectra are observed in the visible range by the BIRA-IASB Multi-Axis Differential Optical Absorption Spectroscopy (MAX-DOAS) instrument and analyzed by the DOAS technique, based on a least-squares spectral fitting. In recent years, this technique has shown to be a well-suited remote sensing tool for monitoring atmospheric trace gases. The retrieval algorithm is developed and validated based on a two month dataset acquired from June to July 2009 in the framework of the Cabauw (51.97° N, 4.93° E) Intercomparison campaign for Nitrogen Dioxide measuring Instruments (CINDI). Once fully operational, the retrieval approach can be applied to observations from stations of the Network for the Detection of Atmospheric Composition Change (NDACC). The obtained tropospheric vertical column amounts are compared with the multi-axis retrieval from the BIRA-IASB MAX-DOAS instrument and the retrieval from a zenith-viewing only SAOZ instrument (Système d'Analyse par Observations Zénithales), owned by Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS). First results show a good agreement for the whole time series with the multi-axis retrieval (R = 0.82; y = 0.88x + 0.30) as well as with the SAOZ retrieval (R = 0.85; y = 0.76x + 0.28 ). Main error sources arise from the uncertainties in the determination of tropospheric and stratospheric air mass factors, the stratospheric NO2 abundances and the residual amount in the reference spectrum. However zenith-sky measurements have been commonly used over the last decades for stratospheric monitoring, this study also illustrates the suitability for retrieval of tropospheric column amounts. As there are long time series of zenith-sky acquisitions available, the developed approach offers new perspectives with regard to the use of observations from the NDACC

  12. Titius--Bode law and the possibility of recent large-scale evolution in the solar system

    International Nuclear Information System (INIS)

    Neito, M.M.

    1974-01-01

    Although it is by no means clear that the Titius--Bode law of planetary distances is indeed a ''law'' (even though there are enticing indications), it is proposed that if one assumes that the law is a ''law'' and that the planets obey it, then this argues against recent large-scale evolution in the solar system. Put another way: one can believe in the Titius--Bode law or in recent large-scale evolution or in neither of them. But it appears difficult to believe in both of them

  13. Determination of coupling coefficients at various zenith angles of the basis of the cosmic ray azimuth effect

    Science.gov (United States)

    Belskiy, S. A.; Dmitriev, B. A.; Romanov, A. M.

    1975-01-01

    The value of EW asymmetry and coupling coefficients at different zenith angles were measured by means of a double coincidence crossed telescope which gives an opportunity to measure simultaneously the intensity of the cosmic ray hard component at zenith angles from 0 to 84 deg in opposite azimuths. The advantages of determining the coupling coefficients by the cosmic ray azimuth effect as compared to their measurement by the latitudinal effect are discussed.

  14. Light management in large area thin-film silicon solar modules

    Czech Academy of Sciences Publication Activity Database

    Losio, P.A.; Caglar, O.; Cashmore, J.S.; Hötzel, J.E.; Ristau, S.; Holovský, Jakub; Remeš, Zdeněk; Sinicco, I.

    2015-01-01

    Roč. 143, Dec (2015), s. 375-385 ISSN 0927-0248 R&D Projects: GA ČR(CZ) GA14-05053S Institutional support: RVO:68378271 Keywords : micromorph * thin-film silicon solar cells * light management * ZnO Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 4.732, year: 2015

  15. New large solar photocatalytic plant: set-up and preliminary results.

    Science.gov (United States)

    Malato, S; Blanco, J; Vidal, A; Fernández, P; Cáceres, J; Trincado, P; Oliveira, J C; Vincent, M

    2002-04-01

    A European industrial consortium called SOLARDETOX has been created as the result of an EC-DGXII BRITE-EURAM-III-financed project on solar photocatalytic detoxification of water. The project objective was to develop a simple, efficient and commercially competitive water-treatment technology, based on compound parabolic collectors (CPCs) solar collectors and TiO2 photocatalysis, to make possible easy design and installation. The design, set-up and preliminary results of the main project deliverable, the first European industrial solar detoxification treatment plant, is presented. This plant has been designed for the batch treatment of 2 m3 of water with a 100 m2 collector-aperture area and aqueous aerated suspensions of polycrystalline TiO2 irradiated by sunlight. Fully automatic control reduces operation and maintenance manpower. Plant behaviour has been compared (using dichloroacetic acid and cyanide at 50 mg l(-1) initial concentration as model compounds) with the small CPC pilot plants installed at the Plataforma Solar de Almería several years ago. The first results with high-content cyanide (1 g l(-1)) waste water are presented and plant treatment capacity is calculated.

  16. Flexibility of Large-Scale Solar Heating Plant with Heat Pump and Thermal Energy Storage

    DEFF Research Database (Denmark)

    Luc, Katarzyna Marta; Heller, Alfred; Rode, Carsten

    2017-01-01

    to decrease biomass use in a district heating system. The paper focuses on the renewable energy-based district heating system in Marstal, Denmark, with heat produced in central solar heating plant, wood pellet boiler, heat pump and bio-oil boiler. The plant has been the object of research and developments...

  17. Large Area Thin Film Silicon: Synergy between Displays and Solar Cells

    NARCIS (Netherlands)

    Schropp, R.E.I.

    2012-01-01

    Thin-film silicon technology has changed our society, owing to the rapid advance of its two major application fields in communication (thin-film displays) and sustainable energy (thin-film solar cells). Throughout its development, advances in these application fields have always benefitted each

  18. SSALMON - The Solar Simulations for the Atacama Large Millimeter Observatory Network

    Czech Academy of Sciences Publication Activity Database

    Wedemeyer, S.; Bastian, T.S.; Brajsa, R.; Bárta, Miroslav; Hudson, H. S.; Fleishman, G.; Loukitcheva, M.; Fleck, B.; Kontar, E.; de Pontieu, B.; Tiwari, S.; Kato, Y.; Soler, R.; Yagoubov, P.; Black, J.H.; Antolin, P.; Gunár, Stanislav; Labrosse, N.; Benz, A. O.; Nindos, A.; Steffen, M.; Scullion, E.; Doyle, J.G.; Zaqarashvili, T.; Hanslmeier, A.; Nakariakov, V. M.; Heinzel, Petr; Ayres, T.; Karlický, Marian

    2015-01-01

    Roč. 56, č. 12 (2015), s. 2679-2692 ISSN 0273-1177 R&D Projects: GA ČR GA13-24782S EU Projects: European Commission(XE) 312495 Institutional support: RVO:67985815 Keywords : solar atmosphere * chromosphere * millimeter radiation Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics Impact factor: 1.409, year: 2015

  19. DROPOUT OF DIRECTIONAL ELECTRON INTENSITIES IN LARGE SOLAR ENERGETIC PARTICLE EVENTS

    Energy Technology Data Exchange (ETDEWEB)

    Tan, Lun C. [Department of Astronomy, University of Maryland, College Park, MD 20742 (United States); Reames, Donald V., E-mail: ltan@umd.edu [Institute for Physical Science and Technology, University of Maryland, College Park, MD 20742 (United States)

    2016-01-10

    In the “gradual” solar energetic particle (SEP) event during solar cycle 23 we have observed the dispersionless modulation (“dropout”) in directional intensities of nonrelativistic electrons. The average duration of dropout periods is ∼0.8 hr, which is consistent with the correlation scale of solar wind turbulence. During the dropout period electrons could display scatter-free transport in an intermittent way. Also, we have observed a decrease in the anisotropic index of incident electrons with increasing electron energy (E{sub e}), while the index of scattered/reflected electrons is nearly independent of E{sub e}. We hence perform an observational examination of the correlation between the anisotropic index of low-energy scattered/reflected electrons and the signature of the locally measured solar wind turbulence in the dissipation range, which is responsible for resonant scattering of nonrelativistic electrons. Since during the dropout period the slab turbulence fraction is dominant (0.8 ± 0.1), we pay close attention to the effect of slab fraction on the correlation examined. Our observation is consistent with the simulation result that in the dominance of the slab turbulence component there should exist a dispatched structure of magnetic flux tubes, along which electrons could be transported in a scatter-free manner. Since a similar phenomenon is exhibited in the “impulsive” SEP event, electron dropout should be a transport effect. Therefore, being different from most ion dropout events, which are due to a compact flare source, the dropout of directional electron intensities should be caused by the change of turbulence status in the solar wind.

  20. DROPOUT OF DIRECTIONAL ELECTRON INTENSITIES IN LARGE SOLAR ENERGETIC PARTICLE EVENTS

    International Nuclear Information System (INIS)

    Tan, Lun C.; Reames, Donald V.

    2016-01-01

    In the “gradual” solar energetic particle (SEP) event during solar cycle 23 we have observed the dispersionless modulation (“dropout”) in directional intensities of nonrelativistic electrons. The average duration of dropout periods is ∼0.8 hr, which is consistent with the correlation scale of solar wind turbulence. During the dropout period electrons could display scatter-free transport in an intermittent way. Also, we have observed a decrease in the anisotropic index of incident electrons with increasing electron energy (E e ), while the index of scattered/reflected electrons is nearly independent of E e . We hence perform an observational examination of the correlation between the anisotropic index of low-energy scattered/reflected electrons and the signature of the locally measured solar wind turbulence in the dissipation range, which is responsible for resonant scattering of nonrelativistic electrons. Since during the dropout period the slab turbulence fraction is dominant (0.8 ± 0.1), we pay close attention to the effect of slab fraction on the correlation examined. Our observation is consistent with the simulation result that in the dominance of the slab turbulence component there should exist a dispatched structure of magnetic flux tubes, along which electrons could be transported in a scatter-free manner. Since a similar phenomenon is exhibited in the “impulsive” SEP event, electron dropout should be a transport effect. Therefore, being different from most ion dropout events, which are due to a compact flare source, the dropout of directional electron intensities should be caused by the change of turbulence status in the solar wind

  1. First detection of thermal radio emission from solar-type stars with the Karl G. Jansky very large array

    Energy Technology Data Exchange (ETDEWEB)

    Villadsen, Jackie; Hallinan, Gregg; Bourke, Stephen [Department of Astronomy, California Institute of Technology, 1200 E. California Ave., Pasadena, CA 91125 (United States); Güdel, Manuel [Department of Astrophysics, University of Vienna, Türkenschanzstrasse 17, A-1180 Vienna (Austria); Rupen, Michael, E-mail: jrv@astro.caltech.edu [National Radio Astronomy Observatory, Socorro, NM 87801 (United States)

    2014-06-20

    We present the first detections of thermal radio emission from the atmospheres of solar-type stars τ Cet, η Cas A, and 40 Eri A. These stars all resemble the Sun in age and level of magnetic activity, as indicated by X-ray luminosity and chromospheric emission in Ca II H and K lines. We observed these stars with the Karl G. Jansky Very Large Array with sensitivities of a few μJy at combinations of 10.0, 15.0, and 34.5 GHz. τ Cet, η Cas A, and 40 Eri A are all detected at 34.5 GHz with signal-to-noise ratios of 6.5, 5.2, and 4.5, respectively. 15.0 GHz upper limits imply a rising spectral index greater than 1.0 for τ Cet and 1.6 for η Cas A, at the 95% confidence level. The measured 34.5 GHz flux densities correspond to stellar disk-averaged brightness temperatures of roughly 10,000 K, similar to the solar brightness temperature at the same frequency. We explain this emission as optically thick thermal free-free emission from the chromosphere, with possible contributions from coronal gyroresonance emission above active regions and coronal free-free emission. These and similar quality data on other nearby solar-type stars, when combined with Atacama Large Millimeter/Submillimeter Array observations, will enable the construction of temperature profiles of their chromospheres and lower transition regions.

  2. First detection of thermal radio emission from solar-type stars with the Karl G. Jansky very large array

    International Nuclear Information System (INIS)

    Villadsen, Jackie; Hallinan, Gregg; Bourke, Stephen; Güdel, Manuel; Rupen, Michael

    2014-01-01

    We present the first detections of thermal radio emission from the atmospheres of solar-type stars τ Cet, η Cas A, and 40 Eri A. These stars all resemble the Sun in age and level of magnetic activity, as indicated by X-ray luminosity and chromospheric emission in Ca II H and K lines. We observed these stars with the Karl G. Jansky Very Large Array with sensitivities of a few μJy at combinations of 10.0, 15.0, and 34.5 GHz. τ Cet, η Cas A, and 40 Eri A are all detected at 34.5 GHz with signal-to-noise ratios of 6.5, 5.2, and 4.5, respectively. 15.0 GHz upper limits imply a rising spectral index greater than 1.0 for τ Cet and 1.6 for η Cas A, at the 95% confidence level. The measured 34.5 GHz flux densities correspond to stellar disk-averaged brightness temperatures of roughly 10,000 K, similar to the solar brightness temperature at the same frequency. We explain this emission as optically thick thermal free-free emission from the chromosphere, with possible contributions from coronal gyroresonance emission above active regions and coronal free-free emission. These and similar quality data on other nearby solar-type stars, when combined with Atacama Large Millimeter/Submillimeter Array observations, will enable the construction of temperature profiles of their chromospheres and lower transition regions.

  3. Solar total energy-large scale experiment, Shenandoah, Georgia site. Annual report, June 1977--June 1978. [For Bleyle Knitwear Plant

    Energy Technology Data Exchange (ETDEWEB)

    None,

    1978-06-01

    The site was described in terms of location, suitably, accessibility, and other factors. Detailed descriptions of the Solar Total Energy-Large Scale Experiment Application (STE-LSE) (Bleyle of America, Inc., Knitwear Plant), the DOE owned Meteorology Station operating at the site, and the instrumentation provided by the Georgia Power Company to measure energy usage within the knitwear plant are included. A detailed report of progress is given at the Shenandoah Site, introduced by the STE-LSE schedule and the Cooperative Agreement work tasks. Progress is described in terms of the following major task areas: site/application; instrumentation/data acquisition; meteorology station; site to STES interface; information dissemination. A brief overview of milestones to be accomplished is given, followed by these appendices: solar easement agreement, interface drawing set, and additional site background data. (MHR)

  4. Initial Validation of Robotic Operations for In-Space Assembly of a Large Solar Electric Propulsion Transport Vehicle

    Science.gov (United States)

    Komendera, Erik E.; Dorsey, John T.

    2017-01-01

    Developing a capability for the assembly of large space structures has the potential to increase the capabilities and performance of future space missions and spacecraft while reducing their cost. One such application is a megawatt-class solar electric propulsion (SEP) tug, representing a critical transportation ability for the NASA lunar, Mars, and solar system exploration missions. A series of robotic assembly experiments were recently completed at Langley Research Center (LaRC) that demonstrate most of the assembly steps for the SEP tug concept. The assembly experiments used a core set of robotic capabilities: long-reach manipulation and dexterous manipulation. This paper describes cross-cutting capabilities and technologies for in-space assembly (ISA), applies the ISA approach to a SEP tug, describes the design and development of two assembly demonstration concepts, and summarizes results of two sets of assembly experiments that validate the SEP tug assembly steps.

  5. Roll coated large area ITO- and vacuum-free all organic solar cells from diketopyrrolopyrrole based non-fullerene acceptors with molecular geometry effects

    DEFF Research Database (Denmark)

    Brandt, Rasmus Guldbaek; Zhang, Fei; Andersen, Thomas Rieks

    2016-01-01

    morphology, and photovoltaic performance of both spin-coated ITO based and roll coated large area, ITO- and vacuum-free organic solar cells (OSCs). For spin-coated devices based on P3HT as the donor polymer the solar cells gave power conversion efficiencies (PCEs) in the following order for (P3HT:PhDMe(DPP)2...

  6. Morphology and velocity field of the large flare on the solar disc on July 14, 1980

    International Nuclear Information System (INIS)

    Xuan, J.; Li, Z.

    1982-01-01

    The active region morphology and the features of solar radio bursts and the sight-line velocity distribution of a flare of importance 3B on the solar disk (AR 2562) on July 14, 1980, are discussed. The preliminary analysis made here suggests that measurement of the velocity fields of active regions is important in treating flare mechanisms. It is noted that a few hours before the eruption of the flare, the penumbral fibers of the sunspots on the corresponding photospheric part under the flare rapidly attenuated. It is thought that the instability of the flare may derive from the rapid changes occurring in the magnetic boundary conditions of the photosphere. These in turn denote the rapid emergence, subsidence, or dissipation of the magnetic flux. The spectra of the active filament in the later period of the flare are seen as indicating that most of the ejection matter was rolling, in addition to ascending or descending

  7. A Parametric Genetic Algorithm Approach to Assess Complementary Options of Large Scale Wind-solar Coupling

    Institute of Scientific and Technical Information of China (English)

    Tim; Mareda; Ludovic; Gaudard; Franco; Romerio

    2017-01-01

    The transitional path towards a highly renewable power system based on wind and solar energy sources is investigated considering their intermittent and spatially distributed characteristics. Using an extensive weather-driven simulation of hourly power mismatches between generation and load, we explore the interplay between geographical resource complementarity and energy storage strategies. Solar and wind resources are considered at variable spatial scales across Europe and related to the Swiss load curve, which serve as a typical demand side reference. The optimal spatial distribution of renewable units is further assessed through a parameterized optimization method based on a genetic algorithm. It allows us to explore systematically the effective potential of combined integration strategies depending on the sizing of the system, with a focus on how overall performance is affected by the definition of network boundaries. Upper bounds on integration schemes are provided considering both renewable penetration and needed reserve power capacity. The quantitative trade-off between grid extension, storage and optimal wind-solar mix is highlighted.This paper also brings insights on how optimal geographical distribution of renewable units evolves as a function of renewable penetration and grid extent.

  8. Large Scale Automatic Analysis and Classification of Roof Surfaces for the Installation of Solar Panels Using a Multi-Sensor Aerial Platform

    Directory of Open Access Journals (Sweden)

    Luis López-Fernández

    2015-09-01

    Full Text Available A low-cost multi-sensor aerial platform, aerial trike, equipped with visible and thermographic sensors is used for the acquisition of all the data needed for the automatic analysis and classification of roof surfaces regarding their suitability to harbor solar panels. The geometry of a georeferenced 3D point cloud generated from visible images using photogrammetric and computer vision algorithms, and the temperatures measured on thermographic images are decisive to evaluate the areas, tilts, orientations and the existence of obstacles to locate the optimal zones inside each roof surface for the installation of solar panels. This information is complemented with the estimation of the solar irradiation received by each surface. This way, large areas may be efficiently analyzed obtaining as final result the optimal locations for the placement of solar panels as well as the information necessary (location, orientation, tilt, area and solar irradiation to estimate the productivity of a solar panel from its technical characteristics.

  9. Augmentation of Quasi-Zenith Satellite Positioning System Using High Altitude Platforms Systems (HAPS)

    Science.gov (United States)

    Tsujii, Toshiaki; Harigae, Masatoshi

    Recently, some feasibility studies on a regional positioning system using the quasi-zenith satellites and the geostationary satellites have been conducted in Japan. However, the geometry of this system seems to be unsatisfactory in terms of the positioning accuracy in north-south direction. In this paper, an augmented satellite positioning system by the High Altitude Platform Systems (HAPS) is proposed since the flexibility of the HAPS location is effective to improve the geometry of satellite positioning system. The improved positioning performance of the augmented system is also demonstrated.

  10. A method for comparison of experimental and theoretical differential neutron spectra in the Zenith reactor

    International Nuclear Information System (INIS)

    Reed, D.L.; Symons, C.R.

    1965-01-01

    A method of calculation is given which assists the analyses of chopper measurements of spectra from ZENITH and enables complex multigroup theoretical calculations of the spectra to be put into a form which may be compared with experiment. In addition the theory of the cut-off function has been extended to give analytical expressions which take into account the effects of sub-collimators, off centre slits and of a rotor made of a material partially transparent to neutrons. The theoretical cut-off function suggested shows good agreement with experiment. (author)

  11. A method for comparison of experimental and theoretical differential neutron spectra in the Zenith reactor

    Energy Technology Data Exchange (ETDEWEB)

    Reed, D L; Symons, C R [General Reactor Physics Division, Atomic Energy Establishment, Winfrith, Dorchester, Dorset (United Kingdom)

    1965-01-15

    A method of calculation is given which assists the analyses of chopper measurements of spectra from ZENITH and enables complex multigroup theoretical calculations of the spectra to be put into a form which may be compared with experiment. In addition the theory of the cut-off function has been extended to give analytical expressions which take into account the effects of sub-collimators, off centre slits and of a rotor made of a material partially transparent to neutrons. The theoretical cut-off function suggested shows good agreement with experiment. (author)

  12. Momentum and zenithal dependence of the enhancements of intensities of cosmic ray muons

    International Nuclear Information System (INIS)

    Abdel-Monem, M.S.; Osborne, A.R.; Benbrook, J.R.; Sheldon, W.R.; Duller, N.M.; Green, P.J.; Choate, L.M.; Magnusson, C.E.

    1977-01-01

    The absolute directional differential intensities of high-energy cosmic ray muons near sea level have been measured over the momentum range 2-700 GeV/c in the vertical direction and zenithal interval 55deg-90deg. The measurements were made with the AMH magnetic spectrometer-telescope. The enhancements I(65deg)/I(0deg) and I(80deg)/I(0deg) of the muon intensities as a function of momentum are presented and compared with the theoretical results of Maeda and Asbury et al. (author)

  13. A solvent- and vacuum-free route to large-area perovskite films for efficient solar modules

    Science.gov (United States)

    Chen, Han; Ye, Fei; Tang, Wentao; He, Jinjin; Yin, Maoshu; Wang, Yanbo; Xie, Fengxian; Bi, Enbing; Yang, Xudong; Grätzel, Michael; Han, Liyuan

    2017-10-01

    Recent advances in the use of organic-inorganic hybrid perovskites for optoelectronics have been rapid, with reported power conversion efficiencies of up to 22 per cent for perovskite solar cells. Improvements in stability have also enabled testing over a timescale of thousands of hours. However, large-scale deployment of such cells will also require the ability to produce large-area, uniformly high-quality perovskite films. A key challenge is to overcome the substantial reduction in power conversion efficiency when a small device is scaled up: a reduction from over 20 per cent to about 10 per cent is found when a common aperture area of about 0.1 square centimetres is increased to more than 25 square centimetres. Here we report a new deposition route for methyl ammonium lead halide perovskite films that does not rely on use of a common solvent or vacuum: rather, it relies on the rapid conversion of amine complex precursors to perovskite films, followed by a pressure application step. The deposited perovskite films were free of pin-holes and highly uniform. Importantly, the new deposition approach can be performed in air at low temperatures, facilitating fabrication of large-area perovskite devices. We reached a certified power conversion efficiency of 12.1 per cent with an aperture area of 36.1 square centimetres for a mesoporous TiO2-based perovskite solar module architecture.

  14. Large enhancement in photocurrent by Mn doping in CdSe/ZTO quantum dot sensitized solar cells.

    Science.gov (United States)

    Pimachev, Artem; Poudyal, Uma; Proshchenko, Vitaly; Wang, Wenyong; Dahnovsky, Yuri

    2016-09-29

    We find a large enhancement in the efficiency of CdSe quantum dot sensitized solar cells by doping with manganese. In the presence of Mn impurities in relatively small concentrations (2.3%) the photoelectric current increases by up to 190%. The average photocurrent enhancement is about 160%. This effect cannot be explained by a light absorption mechanism because the experimental and theoretical absorption spectra demonstrate that there is no change in the absorption coefficient in the presence of the Mn impurities. To explain such a large increase in the injection current we propose a tunneling mechanism of electron injection from the quantum dot LUMO state to the Zn 2 SnO 4 (ZTO) semiconductor photoanode. The calculated enhancement is approximately equal to 150% which is very close to the experimental average value of 160%. The relative discrepancy between the calculated and experimentally measured ratios of the IPCE currents is only 6.25%. For other mechanisms (such as electron trapping, etc.) the remaining 6.25% cannot explain the large change in the experimental IPCE. Thus we have indirectly proved that electron tunneling is the major mechanism of photocurrent enhancement. This work proposes a new approach for a significant improvement in the efficiency of quantum dot sensitized solar cells.

  15. Application of CBD-Zinc Sulfide Film as an Antireflection Coating on Very Large Area Multicrystalline Silicon Solar Cell

    OpenAIRE

    U. Gangopadhyay; K. Kim; S. K. Dhungel; H. Saha; J. Yi

    2007-01-01

    The low-cost chemical bath deposition (CBD) technique is used to prepare CBD-ZnS films as antireflective (AR) coating for multicrystalline silicon solar cells. The uniformity of CBD-ZnS film on large area of textured multicrystalline silicon surface is the major challenge of CBD technique. In the present work, attempts have been made for the first time to improve the rate of deposition and uniformity of deposited film by controlling film stoichiometry and refractive index and also to minimize...

  16. A large-scale view of Space Technology 5 magnetometer response to solar wind drivers.

    Science.gov (United States)

    Knipp, D J; Kilcommons, L M; Gjerloev, J; Redmon, R J; Slavin, J; Le, G

    2015-04-01

    In this data report we discuss reprocessing of the Space Technology 5 (ST5) magnetometer database for inclusion in NASA's Coordinated Data Analysis Web (CDAWeb) virtual observatory. The mission consisted of three spacecraft flying in elliptical orbits, from 27 March to 27 June 2006. Reprocessing includes (1) transforming the data into the Modified Apex Coordinate System for projection to a common reference altitude of 110 km, (2) correcting gain jumps, and (3) validating the results. We display the averaged magnetic perturbations as a keogram, which allows direct comparison of the full-mission data with the solar wind values and geomagnetic indices. With the data referenced to a common altitude, we find the following: (1) Magnetic perturbations that track the passage of corotating interaction regions and high-speed solar wind; (2) unexpectedly strong dayside perturbations during a solstice magnetospheric sawtooth oscillation interval characterized by a radial interplanetary magnetic field (IMF) component that may have enhanced the accompanying modest southward IMF; and (3) intervals of reduced magnetic perturbations or "calms," associated with periods of slow solar wind, interspersed among variable-length episodic enhancements. These calms are most evident when the IMF is northward or projects with a northward component onto the geomagnetic dipole. The reprocessed ST5 data are in very good agreement with magnetic perturbations from the Defense Meteorological Satellite Program (DMSP) spacecraft, which we also map to 110 km. We briefly discuss the methods used to remap the ST5 data and the means of validating the results against DMSP. Our methods form the basis for future intermission comparisons of space-based magnetometer data.

  17. Use of the ARM Measurements of Spectral Zenith Radiance for Better Understanding of 3D Cloud-Radiation Processes & Aerosol-Cloud Interaction

    Energy Technology Data Exchange (ETDEWEB)

    Alexander Marshak; Warren Wiscombe; Yuri Knyazikhin; Christine Chiu

    2011-05-24

    We proposed a variety of tasks centered on the following question: what can we learn about 3D cloud-radiation processes and aerosol-cloud interaction from rapid-sampling ARM measurements of spectral zenith radiance? These ARM measurements offer spectacular new and largely unexploited capabilities in both the temporal and spectral domains. Unlike most other ARM instruments, which average over many seconds or take samples many seconds apart, the new spectral zenith radiance measurements are fast enough to resolve natural time scales of cloud change and cloud boundaries as well as the transition zone between cloudy and clear areas. In the case of the shortwave spectrometer, the measurements offer high time resolution and high spectral resolution, allowing new discovery-oriented science which we intend to pursue vigorously. Research objectives are, for convenience, grouped under three themes: • Understand radiative signature of the transition zone between cloud-free and cloudy areas using data from ARM shortwave radiometers, which has major climatic consequences in both aerosol direct and indirect effect studies. • Provide cloud property retrievals from the ARM sites and the ARM Mobile Facility for studies of aerosol-cloud interactions. • Assess impact of 3D cloud structures on aerosol properties using passive and active remote sensing techniques from both ARM and satellite measurements.

  18. New Techniques Used in Modeling the 2017 Total Solar Eclipse: Energizing and Heating the Large-Scale Corona

    Science.gov (United States)

    Downs, Cooper; Mikic, Zoran; Linker, Jon A.; Caplan, Ronald M.; Lionello, Roberto; Torok, Tibor; Titov, Viacheslav; Riley, Pete; Mackay, Duncan; Upton, Lisa

    2017-08-01

    Over the past two decades, our group has used a magnetohydrodynamic (MHD) model of the corona to predict the appearance of total solar eclipses. In this presentation we detail recent innovations and new techniques applied to our prediction model for the August 21, 2017 total solar eclipse. First, we have developed a method for capturing the large-scale energized fields typical of the corona, namely the sheared/twisted fields built up through long-term processes of differential rotation and flux-emergence/cancellation. Using inferences of the location and chirality of filament channels (deduced from a magnetofrictional model driven by the evolving photospheric field produced by the Advective Flux Transport model), we tailor a customized boundary electric field profile that will emerge shear along the desired portions of polarity inversion lines (PILs) and cancel flux to create long twisted flux systems low in the corona. This method has the potential to improve the morphological shape of streamers in the low solar corona. Second, we apply, for the first time in our eclipse prediction simulations, a new wave-turbulence-dissipation (WTD) based model for coronal heating. This model has substantially fewer free parameters than previous empirical heating models, but is inherently sensitive to the 3D geometry and connectivity of the coronal field---a key property for modeling/predicting the thermal-magnetic structure of the solar corona. Overall, we will examine the effect of these considerations on white-light and EUV observables from the simulations, and present them in the context of our final 2017 eclipse prediction model.Research supported by NASA's Heliophysics Supporting Research and Living With a Star Programs.

  19. 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

  20. 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

  1. Non-uniform Solar Temperature Field on Large Aperture, Fully-Steerable Telescope Structure

    Science.gov (United States)

    Liu, Yan

    2016-09-01

    In this study, a 110-m fully steerable radio telescope was used as an analysis platform and the integral parametric finite element model of the antenna structure was built in the ANSYS thermal analysis module. The boundary conditions of periodic air temperature, solar radiation, long-wave radiation shadows of the surrounding environment, etc. were computed at 30 min intervals under a cloudless sky on a summer day, i.e., worstcase climate conditions. The transient structural temperatures were then analyzed under a period of several days of sunshine with a rational initial structural temperature distribution until the whole set of structural temperatures converged to the results obtained the day before. The non-uniform temperature field distribution of the entire structure and the main reflector surface RMS were acquired according to changes in pitch and azimuth angle over the observation period. Variations in the solar cooker effect over time and spatial distributions in the secondary reflector were observed to elucidate the mechanism of the effect. The results presented here not only provide valuable realtime data for the design, construction, sensor arrangement and thermal deformation control of actuators but also provide a troubleshooting reference for existing actuators.

  2. Correlations at large scales and the onset of turbulence in the fast solar wind

    International Nuclear Information System (INIS)

    Wicks, R. T.; Roberts, D. A.; Mallet, A.; Schekochihin, A. A.; Horbury, T. S.; Chen, C. H. K.

    2013-01-01

    We show that the scaling of structure functions of magnetic and velocity fields in a mostly highly Alfvénic fast solar wind stream depends strongly on the joint distribution of the dimensionless measures of cross helicity and residual energy. Already at very low frequencies, fluctuations that are both more balanced (cross helicity ∼0) and equipartitioned (residual energy ∼0) have steep structure functions reminiscent of 'turbulent' scalings usually associated with the inertial range. Fluctuations that are magnetically dominated (residual energy ∼–1), and so have closely anti-aligned Elsasser-field vectors, or are imbalanced (cross helicity ∼1), and so have closely aligned magnetic and velocity vectors, have wide '1/f' ranges typical of fast solar wind. We conclude that the strength of nonlinear interactions of individual fluctuations within a stream, diagnosed by the degree of correlation in direction and magnitude of magnetic and velocity fluctuations, determines the extent of the 1/f region observed, and thus the onset scale for the turbulent cascade.

  3. Solar-terrestrial effect controls seismic activity to a large extent (Invited)

    Science.gov (United States)

    Duma, G.

    2010-12-01

    Several observational results and corresponding publications in the 20 century indicate that earthquakes in many regions happen systematically in dependence on the time of day and on the season as well. In the recent decade, studies on this topic have also been intensively performed at the Central Institute for Meteorology and Geodynamics (ZAMG), Vienna. Any natural effect on Earth which systematically appears at certain hours of the day or at a special season can solely be caused by a solar or lunar influence. And actually, statistic results on seismic activity reveal a correlation with the solar cycles. Examples of this seismic performance are shown. To gain more clarity about these effects, the three-hour magnetic index Kp, which characterizes the magnetic field disturbances, mainly caused by the solar particle radiation, the solar wind, was correlated with the seismic energy released by earthquakes over decades. Kp is determined from magnetic records of 13 observatories worldwide and continuously published by ISGI, France. It is demonstrated that a highly significant correlation between the geomagnetic index Kp and the annual seismic energy release in regions at latitudes between 35 and 60° N exists. Three regions of continental size were investigated, using the USGS (PDE) earthquake catalogue data. In the period 1974-2009 the Kp cycle periods range between 9 and 12 years, somewhat different to the sunspot number cycles of 11 years. Seismicity follows the Kp cycles with high coincidence. A detailed analysis of this correlation for N-America reveals, that the sum of released energy by earthquakes per year changes by a factor up to 100 with Kp. It is shown that during years of high Kp there happen e.g. 1 event M7, 4 events M6 and 30 events M5 per year, instead of only 10 events M5 in years with lowest Kp. Almost the same relation appears in other regions of continental size, with the same significance. The seismicity in S-America clearly follows the Kp cycles

  4. Plan of Time Management of Satellite Positioning System using Quasi-zenith Satellite

    Science.gov (United States)

    Takahashi, Yasuhiro; Fujieda, Miho; Amagai, Jun; Yokota, Shoichiro; Kimura, Kazuhiro; Ito, Hiroyuki; Hama, Shin'ichi; Morikawa, Takao; Kawano, Isao; Kogure, Satoshi

    The Quasi-Zenith satellites System (QZSS) is developed as an integrated satellite service system of communication, broadcasting and positioning for mobile users in specified regions of Japan from high elevation angle. Purposes of the satellite positioning system using Quasi-Zenith satellite (QZS) are to complement and augment the GPS. The national institutes concerned have been developing the positioning system using QZS since 2003 and will carry out experiments and researches in three years after the launch. In this system, National Institute of Information and Communications Technology (NICT) is mainly in charge of timing system for the satellite positioning system using QZS, such as onboard hydrogen maser atomic clock and precise time management system of the QZSS. We started to develop the engineering model of the time management system for the QZSS. The time management system for the QZSS will be used to compare time differences between QZS and earth station as well as to compare between three onboard atomic clocks. This paper introduces time management of satellite positioning system using the QZSS.

  5. Results of IEA SHC Task 45: Large Scale Solar Heating and Cooling Systems. Subtask A: “Collectors and Collector Loop”

    DEFF Research Database (Denmark)

    Bava, Federico; Nielsen, Jan Erik; Knabl, Samuel

    2016-01-01

    . Within this project, subtask A had the more specific objectives of investigating ways to evaluate the influence that different operating conditions can have on the collector performance, assure proper and safe installation of large solar collector fields, and guarantee their performance and yearly energy......The IEA SHC Task 45 Large Scale Solar Heating and Cooling Systems, carried out between January 2011 and December 2014, had the main objective to assist in the development of a strong and sustainable market of large solar heating systems by focusing on high performance and reliability of systems...... output. The results of the different investigations are presented, with a particular focus on how different parameters such as tilt, flow rate and fluid type, can affect the collector efficiency. Other presented results include methods to guarantee and check the thermal performance of a solar collector...

  6. Plasma surrounding the global heliosphere at large distances controlled by the solar cycle

    Science.gov (United States)

    Dialynas, Konstantinos; Krimigis, Stamatios; Mitchell, Donald; Decker, Robert; Roelof, Edmond

    2016-04-01

    The past decade can be characterized by a series of key, groundbreaking remote energetic neutral atom (ENA) images (INCA, IBEX) and in-situ ion (Voyager 1 & 2) observations concerning the characteristics and interactions of the heliosphere with the Local Interstellar Medium (LISM). Voyagers 1 and 2 (V1, V2) discovered the reservoir of ions and electrons that constitute the heliosheath (HS) after crossing the termination shock (TS) 35deg north and 32deg south of the ecliptic plane at 94 and 84 astronomical units (1 AU= 1.5 x108 km), respectively. The in situ measurements by each Voyager were placed in a global context by remote sensing images using ENA obtained with the Ion and Neutral Camera (INCA) onboard Cassini orbiting Saturn. The ENA images contain a 5.2-55 keV hydrogen (H) ENA region (Belt) that loops through the celestial sphere and contributes to balancing the pressure of the interstellar magnetic field (ISMF). The success of any future mission with dedicated ENA detectors (e.g. the IMAP mission), highly depends on the antecedent understanding of the details of the plasma processes in the Heliosphere as revealed by remote sensing of the plasma environment characteristics. Therefore, we address here one of the remaining and most important questions: "Where do the 5-55 keV ENAs that INCA measures come from?". We analyzed INCA all-sky maps from 2003 to 2015 and compare the solar cycle (SC) variation of the ENAs in both the nose (upstream) and anti-nose (downstream) directions with the intensities of > 30 keV ions (source of ENA through charge exchange-CE with H) measured in-situ by V1 and V2, in overlapping energy bands ~30-55 keV. ENA intensities decrease during the declining phase of SC23 by ~x3 from 2003 to 2011 but recover through 2014 (SC24); similarly, V1 and V2 ion intensities also decrease and then recover through 2014. The similarity of time profiles of remotely sensed ENA and locally measured ions are consistent with (a) ENA originating in the HS

  7. Roll-coating fabrication of flexible large area small molecule solar cells with power conversion efficiency exceeding 1%

    DEFF Research Database (Denmark)

    Liu, Wenqing; Liu, Shiyong; Zawacka, Natalia Klaudia

    2014-01-01

    All solution-processed flexible large area small molecule bulk heterojunction solar cells were fabricated via roll-coating technology. Our devices were produced from slot-die coating on a lab-scale mini roll-coater under ambient conditions without the use of spin-coating or vacuum evaporation.......01%, combined with an open circuit voltage of 0.73 V, a short-circuit current density of 3.13 mA cm (2) and a fill factor of 44% were obtained for the device with SM1, which was the first example reported for efficient roll-coating fabrication of flexible large area small molecule solar cells with PCE exceeding...... methods. Four diketopyrrolopyrrole based small molecules (SMs 1-4) were utilized as electron donors with (6,6)phenyl- C61-butyric acid methyl ester as an acceptor and their photovoltaic performances based on roll-coated devices were investigated. The best power conversion efficiency (PCE) of 1...

  8. Super enrichment of Fe-group nuclei in solar flares and their association with large 3He enrichments

    International Nuclear Information System (INIS)

    Anglin, J.D.; Dietrich, W.F.; Simpson, J.A.

    1977-01-01

    ''Fe''/He ratios at approximately 2 MeV/n have been measured in 60 solar flares and periods of enhanced fluxes during the interval 1972-1976. The observed ditribution of ratios is extremely wide with values ranging from approximately 1 to more than 1000 times the solar abundance ratio. In constrast, most of the CHO/He ratios for the same flares lie within a factor 2 of the observed mean value of 2 x 10 -2 . While experimental limitations prevent a complete correlation study of Fe-group and 3 He abundances, comparison of flares with large Fe enrichments with flares with large 3 He enrichments for the period 1969-1976 shows that a 3 He-rich flare is also likely to be rich in iron. We feel that the association of 3 He and Fe enrichments may be explained by a two-stage process in which a preliminary enrichment of heavy nuclei precedes the preferential acceleration of ambient 3 He. Nuclear interactions are ruled out as the principal source of the enriched 3 He. (author)

  9. LSA Large Area Silicon Sheet Task. Continuous Liquid Feed Czochralski Growth. [for solar cell fabrication

    Science.gov (United States)

    Fiegl, G.

    1979-01-01

    The design and development of equipment and processes to demonstrate continuous growth of crystals by the Czochralski method suitable for producing single silicon crystals for use in solar cells is presented. The growth of at least 150 kg of mono silicon crystal, 150 mm in diameter is continuous from one growth container. A furnace with continuous liquid replenishment of the growth crucible, accomplished by a meltdown system with a continuous solid silicon feed mechanism and a liquid transfer system, with associated automatic feedback controls is discussed. Due to the silicon monoxide build up in the furnace and its retarding effect on crystal growth the furnace conversion for operation in the low pressure range is described. Development of systems for continuous solid recharging of the meltdown chamber for various forms of poly silicon is described.

  10. Collapsible Photovoltaic Module for a Large-Scale Solar Power Plant

    DEFF Research Database (Denmark)

    2014-01-01

    An elongate photovoltaic (PV) module for use in a solar energy conversion plant for the production of electricity from incident light, the PV-module comprising a top portion with a support panel (G) carrying on a front side a plurality of electrically connected PV cells (D), and a transparent...... protective layer (A) sealed to the support panel (G) so as to encapsulate the PV-cells (D) between the support panel (G) and the protective layer (A), wherein prior to installation of the PV-module at the deployment site a collapsible portion of the PV-module is configured to be collapsible in a longitudinal...... direction by folding and/or rolling, wherein the collapsible portion includes at least the top portion, wherein the PV-module further comprises one or more integrated ballast chambers (I) in a bottom portion of the PV-module arranged on a rear side of the support panel (G), wherein said integrated ballast...

  11. Large impacts around a solar-analog star in the era of terrestrial planet formation.

    Science.gov (United States)

    Meng, Huan Y A; Su, Kate Y L; Rieke, George H; Stevenson, David J; Plavchan, Peter; Rujopakarn, Wiphu; Lisse, Carey M; Poshyachinda, Saran; Reichart, Daniel E

    2014-08-29

    The final assembly of terrestrial planets occurs via massive collisions, which can launch copious clouds of dust that are warmed by the star and glow in the infrared. We report the real-time detection of a debris-producing impact in the terrestrial planet zone around a 35-million-year-old solar-analog star. We observed a substantial brightening of the debris disk at a wavelength of 3 to 5 micrometers, followed by a decay over a year, with quasi-periodic modulations of the disk flux. The behavior is consistent with the occurrence of a violent impact that produced vapor out of which a thick cloud of silicate spherules condensed that were then ground into dust by collisions. These results demonstrate how the time domain can become a new dimension for the study of terrestrial planet formation. Copyright © 2014, American Association for the Advancement of Science.

  12. Testing and evaluation of large-area heliostats for solar thermal applications

    Energy Technology Data Exchange (ETDEWEB)

    Strachan, J.W.; Houser, R.M.

    1993-02-01

    Two heliostats representing the state-of-the-art in glass-metal designs for central receiver (and photovoltaic tracking) applications were tested and evaluated at the National Solar Thermal Test Facility in Albuquerque, New Mexico from 1986 to 1992. These heliostats have collection areas of 148 and 200 m{sup 2} and represent low-cost designs for heliostats that employ glass-metal mirrors. The evaluation encompassed the performance and operational characteristics of the heliostats, and examined heliostat beam quality, the effect of elevated winds on beam quality, heliostat drives and controls, mirror module reflectance and durability, and the overall operational and maintenance characteristics of the two heliostats. A comprehensive presentation of the results of these and other tests is presented. The results are prefaced by a review of the development (in the United States) of heliostat technology.

  13. Large-scale Roll-to-Roll Fabrication of Organic Solar Cells for Energy Production

    DEFF Research Database (Denmark)

    Hösel, Markus

    intelligent connection of single cells that should involve as less as possible manual processes such as wiring or soldering. The problem was solved by serially connecting thousands of single cells entirely during the R2R processing by printing thin-film silver conductors. High voltage networks require only...... be produced cheaply and very fast from solution with printing processes. The current research all around the world is still focused on lab-scale sized devices « cm2, ITO-glass substrates, and spin coating as the main fabrication method. These OPV devices are far from any practical application although record...... substrates and ITO-free transparent conductive electrodes made from special designed flexo printed silver grids, rotary screen printed PEDOT:PSS, and slot-die coated ZnO (= Flextrode). The organic solar cell was fabricated by slot-die coating a light absorbing photoactive layer (e. g. P3HT:PCBM) on top...

  14. Helioseismic Constraints on the Depth Dependence of Large-Scale Solar Convection

    Science.gov (United States)

    Woodard, Martin F.

    2017-08-01

    A recent helioseismic statistical waveform analysis of subsurface flow based on a 720-day time series of SOHO/MDI Medium-l spherical-harmonic coefficients has been extended to cover a greater range of subphotospheric depths. The latest analysis provides estimates of flow-dependent oscillation-mode coupling-strength coefficients b(s,t;n,l) over the range l = 30 to 150 of mode degree (angular wavenumber) for solar p-modes in the approximate frequency range 2 to 4 mHz. The range of penetration depths of this mode set covers most of the solar convection zone. The most recent analysis measures spherical harmonic (s,t) components of the flow velocity for odd s in the angular wavenumber range 1 to 19 for t not much smaller than s at a given s. The odd-s b(s,t;n,l) coefficients are interpreted as averages over depth of the depth-dependent amplitude of one spherical-harmonic (s,t) component of the toroidal part of the flow velocity field. The depth-dependent weighting function defining the average velocity is the fractional kinetic energy density in radius of modes of the (n,l) multiplet. The b coefficients have been converted to estimates of root velocity power as a function of l0 = nu0*l/nu(n,l), which is a measure of mode penetration depth. (nu(n,l) is mode frequency and nu0 is a reference frequency equal to 3 mHz.) A comparison of the observational results with simple convection models will be presented.

  15. The large-scale solar feed-in tariff reverse auction in the Australian Capital Territory, Australia

    International Nuclear Information System (INIS)

    Buckman, Greg; Sibley, Jon; Bourne, Richard

    2014-01-01

    Feed-in tariffs (FiTs) offer renewable energy developers significant investor certainty but sometimes at the cost of being misaligned with generation costs. Reverse FiT auctions, where the FiT rights for a predetermined capacity are auctioned, can overcome this problem but can be plagued by non-delivery risks, particularly of competitively priced proposals. In 2012 and 2013 the Australian Capital Territory (ACT) Government in Australia conducted a FiT reverse auction for 40 MW of large-scale solar generating capacity, the first such auction undertaken in the country. The auction was highly competitive in relation to price and demonstrating low delivery risks. Proposal capital costs, particularly engineering, procurement and construction costs, as well as internal rates of return, were lower than expected. The auction process revealed limited land availability for large-scale solar developments in the ACT as well as a significant perceived sovereign risk issue. The auction process was designed to mitigate non-delivery risk by requiring proposals to be pre-qualified on the basis of delivery risk, before considering FiT pricing. The scheme is likely to be used by the ACT Government to support further large-scale renewable energy development as part of its greenhouse gas reduction strategy which is underpinned by a 90-per cent-by-2020 renewable energy target. - Highlights: • Evolution of the reverse auction process in the Australian Capital Territory. • Analysis of the outcomes of the first Australian feed-in tariff reverse auction. • Identification of the major drivers of the low FiT prices achieved in the auction. • Identification of major issues that emerged in the auction

  16. Simultaneous SMM flat crystal spectrometer and Very Large Array observations of solar active regions

    Science.gov (United States)

    Lang, Kenneth R.; Willson, Robert F.; Smith, Kermit L.; Strong, Keith T.

    1987-01-01

    High-resolution images of the quiescent emission from two solar active regions at 20 cm (VLA) and soft X-ray (SMM FCS) wavelengths are compared. There are regions where the X-ray coronal loops have been completely imaged at 20 cm wavelength. In other regions, the X-ray radiation was detected without detectable 20 cm radiation, and vice versa. The X-ray data were used to infer average electron temperatures of about 3-million K and average electron densities of about 2.5 x 10 to the 9th/cu cm for the X-ray emitting plasma in the two active regions. The thermal bremsstrahlung of the X-ray emitting plasma is optically thin at 20 cm wavelength. The 20 cm brightness temperatures were always less than T(e), which is consistent with optically thin bremsstrahlung. The low T(B) can be explained if a higher, cooler plasma covers the hotter X-ray emitting plasma. Thermal gyroresonance radiation must account for the intense 20 cm radiation near and above sunspots where no X-ray radiation is detected.

  17. Ultra-high efficiency photovoltaic cells for large scale solar power generation.

    Science.gov (United States)

    Nakano, Yoshiaki

    2012-01-01

    The primary targets of our project are to drastically improve the photovoltaic conversion efficiency and to develop new energy storage and delivery technologies. Our approach to obtain an efficiency over 40% starts from the improvement of III-V multi-junction solar cells by introducing a novel material for each cell realizing an ideal combination of bandgaps and lattice-matching. Further improvement incorporates quantum structures such as stacked quantum wells and quantum dots, which allow higher degree of freedom in the design of the bandgap and the lattice strain. Highly controlled arrangement of either quantum dots or quantum wells permits the coupling of the wavefunctions, and thus forms intermediate bands in the bandgap of a host material, which allows multiple photon absorption theoretically leading to a conversion efficiency exceeding 50%. In addition to such improvements, microfabrication technology for the integrated high-efficiency cells and the development of novel material systems that realizes high efficiency and low cost at the same time are investigated.

  18. Economic optimization of the energy transport component of a large distributed solar power plant

    Science.gov (United States)

    Turner, R. H.

    1976-01-01

    A solar thermal power plant with a field of collectors, each locally heating some transport fluid, requires a pipe network system for eventual delivery of energy power generation equipment. For a given collector distribution and pipe network geometry, a technique is herein developed which manipulates basic cost information and physical data in order to design an energy transport system consistent with minimized cost constrained by a calculated technical performance. For a given transport fluid and collector conditions, the method determines the network pipe diameter and pipe thickness distribution and also insulation thickness distribution associated with minimum system cost; these relative distributions are unique. Transport losses, including pump work and heat leak, are calculated operating expenses and impact the total system cost. The minimum cost system is readily selected. The technique is demonstrated on six candidate transport fluids to emphasize which parameters dominate the system cost and to provide basic decision data. Three different power plant output sizes are evaluated in each case to determine severity of diseconomy of scale.

  19. Tunnel oxide passivated rear contact for large area n-type front junction silicon solar cells providing excellent carrier selectivity

    Directory of Open Access Journals (Sweden)

    Yuguo Tao

    2016-01-01

    Full Text Available Carrier-selective contact with low minority carrier recombination and efficient majority carrier transport is mandatory to eliminate metal-induced recombination for higher energy conversion efficiency for silicon (Si solar cells. In the present study, the carrier-selective contact consists of an ultra-thin tunnel oxide and a phosphorus-doped polycrystalline Si (poly-Si thin film formed by plasma enhanced chemical vapor deposition (PECVD and subsequent thermal crystallization. It is shown that the poly-Si film properties (doping level, crystallization and dopant activation anneal temperature are crucial for achieving excellent contact passivation quality. It is also demonstrated quantitatively that the tunnel oxide plays a critical role in this tunnel oxide passivated contact (TOPCON scheme to realize desired carrier selectivity. Presence of tunnel oxide increases the implied Voc (iVoc by ~ 125 mV. The iVoc value as high as 728 mV is achieved on symmetric structure with TOPCON on both sides. Large area (239 cm2 n-type Czochralski (Cz Si solar cells are fabricated with homogeneous implanted boron emitter and screen-printed contact on the front and TOPCON on the back, achieving 21.2% cell efficiency. Detailed analysis shows that the performance of these cells is mainly limited by boron emitter recombination on the front side.

  20. A Combined Ethical and Scientific Analysis of Large-scale Tests of Solar Climate Engineering

    Science.gov (United States)

    Ackerman, T. P.

    2017-12-01

    Our research group recently published an analysis of the combined ethical and scientific issues surrounding large-scale testing of stratospheric aerosol injection (SAI; Lenferna et al., 2017, Earth's Future). We are expanding this study in two directions. The first is extending this same analysis to other geoengineering techniques, particularly marine cloud brightening (MCB). MCB has substantial differences to SAI in this context because MCB can be tested over significantly smaller areas of the planet and, following injection, has a much shorter lifetime of weeks as opposed to years for SAI. We examine issues such as the role of intent, the lesser of two evils, and the nature of consent. In addition, several groups are currently considering climate engineering governance tools such as a code of ethics and a registry. We examine how these tools might influence climate engineering research programs and, specifically, large-scale testing. The second direction of expansion is asking whether ethical and scientific issues associated with large-scale testing are so significant that they effectively preclude moving ahead with climate engineering research and testing. Some previous authors have suggested that no research should take place until these issues are resolved. We think this position is too draconian and consider a more nuanced version of this argument. We note, however, that there are serious questions regarding the ability of the scientific research community to move to the point of carrying out large-scale tests.

  1. Large Scale Solar Power Integration in Distribution Grids : PV Modelling, Voltage Support and Aggregation Studies

    NARCIS (Netherlands)

    Samadi, A.

    2014-01-01

    Long term supporting schemes for photovoltaic (PV) system installation have led to accommodating large numbers of PV systems within load pockets in distribution grids. High penetrations of PV systems can cause new technical challenges, such as voltage rise due to reverse power flow during light load

  2. A central solar-industrial waste heat heating system with large scale borehole thermal storage

    NARCIS (Netherlands)

    Guo, F.; Yang, X.; Xu, L.; Torrens, I.; Hensen, J.L.M.

    2017-01-01

    In this paper, a new research of seasonal thermal storage is introduced. This study aims to maximize the utilization of renewable energy source and industrial waste heat (IWH) for urban district heating systems in both heating and non-heating seasons through the use of large-scale seasonal thermal

  3. Inferring spatial clouds statistics from limited field-of-view, zenith observations

    Energy Technology Data Exchange (ETDEWEB)

    Sun, C.H.; Thorne, L.R. [Sandia National Labs., Livermore, CA (United States)

    1996-04-01

    Many of the Cloud and Radiation Testbed (CART) measurements produce a time series of zenith observations, but spatial averages are often the desired data product. One possible approach to deriving spatial averages from temporal averages is to invoke Taylor`s hypothesis where and when it is valid. Taylor`s hypothesis states that when the turbulence is small compared with the mean flow, the covariance in time is related to the covariance in space by the speed of the mean flow. For clouds fields, Taylor`s hypothesis would apply when the {open_quotes}local{close_quotes} turbulence is small compared with advective flow (mean wind). The objective of this study is to determine under what conditions Taylor`s hypothesis holds or does not hold true for broken cloud fields.

  4. Beam-splitter switches based on zenithal bistable liquid-crystal gratings.

    Science.gov (United States)

    Zografopoulos, Dimitrios C; Beccherelli, Romeo; Kriezis, Emmanouil E

    2014-10-01

    The tunable optical diffractive properties of zenithal bistable nematic liquid-crystal gratings are theoretically investigated. The liquid-crystal orientation is rigorously solved via a tensorial formulation of the Landau-de Gennes theory and the optical transmission properties of the gratings are investigated via full-wave finite-element frequency-domain simulations. It is demonstrated that by proper design the two stable states of the grating can provide nondiffracting and diffracting operation, the latter with equal power splitting among different diffraction orders. An electro-optic switching mechanism, based on dual-frequency nematic materials, and its temporal dynamics are further discussed. Such gratings provide a solution towards tunable beam-steering and beam-splitting components with extremely low power consumption.

  5. Order reconstruction phenomena and temperature-driven dynamics in a 3D zenithally bistable device

    KAUST Repository

    Raisch, A.

    2014-07-01

    We model the zenithally bistable device (ZBD) in three dimensions (3D), within the Landau-de Gennes theory, and find three stable static states in 3D without an applied field: the vertically aligned nematic (VAN) state, the hybrid aligned nematic (HAN) state and a third, high-tilt state, which we call the THAN state, with an interior and a surface defect. We recover the order reconstruction (OR) phenomenon around the defects in the HAN and THAN states and the 3D THAN and HAN solutions exhibit stable biaxial cylinders connecting defects on opposite faces of the ZBD device. We demonstrate a two-way temperature-driven switching between high-tilt and low-tilt states through controlled heating and cooling procedures in two dimensions (2D), with no applied fields. © CopyrightEPLA, 2014.

  6. PHYSICAL PROPERTIES OF LARGE AND SMALL GRANULES IN SOLAR QUIET REGIONS

    Energy Technology Data Exchange (ETDEWEB)

    Yu Daren; Xie Zongxia; Hu Qinghua [Harbin Institute of Technology, Harbin 150001 (China); Yang Shuhong; Zhang Jun; Wang Jingxiu, E-mail: caddiexie@hotmail.com, E-mail: zjun@ourstar.bao.ac.cn [Key Laboratory of Solar Activity, National Astronomical Observatories, Chinese Academy of Sciences, Beijing 100012 (China)

    2011-12-10

    The normal mode observations of seven quiet regions obtained by the Hinode spacecraft are analyzed to study the physical properties of granules. An artificial intelligence technique is introduced to automatically find the spatial distribution of granules in feature spaces. In this work, we investigate the dependence of granular continuum intensity, mean Doppler velocity, and magnetic fields on granular diameter. We recognized 71,538 granules by an automatic segmentation technique and then extracted five properties: diameter, continuum intensity, Doppler velocity, and longitudinal and transverse magnetic flux density to describe the granules. To automatically explore the intrinsic structures of the granules in the five-dimensional parameter space, the X-means clustering algorithm and one-rule classifier are introduced to define the rules for classifying the granules. It is found that diameter is a dominating parameter in classifying the granules and two families of granules are derived: small granules with diameters smaller than 1.''44, and large granules with diameters larger than 1.''44. Based on statistical analysis of the detected granules, the following results are derived: (1) the averages of diameter, continuum intensity, and Doppler velocity in the upward direction of large granules are larger than those of small granules; (2) the averages of absolute longitudinal, transverse, and unsigned flux density of large granules are smaller than those of small granules; (3) for small granules, the average of continuum intensity increases with their diameters, while the averages of Doppler velocity, transverse, absolute longitudinal, and unsigned magnetic flux density decrease with their diameters. However, the mean properties of large granules are stable; (4) the intensity distributions of all granules and small granules do not satisfy Gaussian distribution, while that of large granules almost agrees with normal distribution with a peak at 1.04 I

  7. Retrieving Precipitable Water Vapor Data Using GPS Zenith Delays and Global Reanalysis Data in China

    Directory of Open Access Journals (Sweden)

    Peng Jiang

    2016-05-01

    Full Text Available GPS has become a very effective tool to remotely sense precipitable water vapor (PWV information, which is important for weather forecasting and nowcasting. The number of geodetic GNSS stations set up in China has substantially increased over the last few decades. However, GPS PWV derivation requires surface pressure to calculate the precise zenith hydrostatic delay and weighted mean temperature to map the zenith wet delay to precipitable water vapor. GPS stations without collocated meteorological sensors can retrieve water vapor using standard atmosphere parameters, which lead to a decrease in accuracy. In this paper, a method of interpolating NWP reanalysis data to site locations for generating corresponding meteorological elements is explored over China. The NCEP FNL dataset provided by the NCEP (National Centers for Environmental Prediction and over 600 observed stations from different sources was selected to assess the quality of the results. A one-year experiment was performed in our study. The types of stations selected include meteorological sites, GPS stations, radio sounding stations, and a sun photometer station. Compared with real surface measurements, the accuracy of the interpolated surface pressure and air temperature both meet the requirements of GPS PWV derivation in most areas; however, the interpolated surface air temperature exhibits lower precision than the interpolated surface pressure. At more than 96% of selected stations, PWV differences caused by the differences between the interpolation results and real measurements were less than 1.0 mm. Our study also indicates that relief amplitude exerts great influence on the accuracy of the interpolation approach. Unsatisfactory interpolation results always occurred in areas of strong relief. GPS PWV data generated from interpolated meteorological parameters are consistent with other PWV products (radio soundings, the NWP reanalysis dataset, and sun photometer PWV data. The

  8. PERANCANGAN SISTEM PEMESANAN BARANG BERBASIS WEB DI TOKO ZENITH KOMPUTER DI PEKANBARU

    Directory of Open Access Journals (Sweden)

    Fery Wongso Johan Wyanaputra

    2016-03-01

    Full Text Available Abstrak : Sistem Informasi Pemesananberbasis web merupakan bagian dari sistem informasi pemasaran yang dikembangkan untuk mengumpulkan, mengolah data sehingga data tersebut dapat dilihat kembali untuk disalurkan sebagai suatu informasi yang berguna. Wujud dari pengembangan Sistem Informasi Pemesananberbasis web ini adalah pembuatan aplikasi Komputer yang mampu mewakili sistem informasi yang dirancang secara keseluruhan.Aplikasi Sistem Informasi pemesanan yang dihasilkan mampu mengelola data pemesanan secara terorgasisasi, serta menghasilkan laporan yang lengkap, akurat dan selalu aktual untuk setiap tingkatan manajemen. Perancangan sistemnya menggunakan PHP (Personal Home Page dan rancangan databasenya menggunakan Xamp Server. Hasil dari perancangan aplikasi Sistem Informasi Pemesananberbasis web menunjukkan bahwa peranan aplikasi Komputer dalam sistem informasi sangat penting sebagai penunjang dalam meningkatkan kualitas kegiatan Pemesanan dan pelayanan di lingkungan toko Zenith Komputer. Abstract: Information Systems is a web Pemesananberbasis Part Of The Marketing Information System was developed to review collect, process the data so that the data can be Seen Back to review the information supplied as a useful thing. From the form of development of Information Systems web Pemesananberbasis Singer Was Able Computer Application Development Information System Designed represent keseluruhan.Aplikasi Operating System Generated Ordering Information Ability to Manage Booking Data Operating terorgasisasi, as well as generate reports The complete, Accurate And Always Currents for EVERY level management review, The design of the system using PHP (Personal Home Page and database design using XAMP Server. Results From designing web applications Pemesananberbasis Information System showed that Role of Information Systems Computer Application hearts hearts Sangat as supporting activities improving QUALITY Booking And Environmental Services at Zenith

  9. Solar Illumination Control of the Polar Wind

    Science.gov (United States)

    Maes, L.; Maggiolo, R.; De Keyser, J.; André, M.; Eriksson, A. I.; Haaland, S.; Li, K.; Poedts, S.

    2017-11-01

    Polar wind outflow is an important process through which the ionosphere supplies plasma to the magnetosphere. The main source of energy driving the polar wind is solar illumination of the ionosphere. As a result, many studies have found a relation between polar wind flux densities and solar EUV intensity, but less is known about their relation to the solar zenith angle at the ionospheric origin, certainly at higher altitudes. The low energy of the outflowing particles and spacecraft charging means it is very difficult to measure the polar wind at high altitudes. We take advantage of an alternative method that allows estimations of the polar wind flux densities far in the lobes. We analyze measurements made by the Cluster spacecraft at altitudes from 4 up to 20 RE. We observe a strong dependence on the solar zenith angle in the ion flux density and see that both the ion velocity and density exhibit a solar zenith angle dependence as well. We also find a seasonal variation of the flux density.

  10. Meniscus-assisted solution printing of large-grained perovskite films for high-efficiency solar cells

    Science.gov (United States)

    He, Ming; Li, Bo; Cui, Xun; Jiang, Beibei; He, Yanjie; Chen, Yihuang; O'Neil, Daniel; Szymanski, Paul; Ei-Sayed, Mostafa A.; Huang, Jinsong; Lin, Zhiqun

    2017-07-01

    Control over morphology and crystallinity of metal halide perovskite films is of key importance to enable high-performance optoelectronics. However, this remains particularly challenging for solution-printed devices due to the complex crystallization kinetics of semiconductor materials within dynamic flow of inks. Here we report a simple yet effective meniscus-assisted solution printing (MASP) strategy to yield large-grained dense perovskite film with good crystallization and preferred orientation. Intriguingly, the outward convective flow triggered by fast solvent evaporation at the edge of the meniscus ink imparts the transport of perovskite solutes, thus facilitating the growth of micrometre-scale perovskite grains. The growth kinetics of perovskite crystals is scrutinized by in situ optical microscopy tracking to understand the crystallization mechanism. The perovskite films produced by MASP exhibit excellent optoelectronic properties with efficiencies approaching 20% in planar perovskite solar cells. This robust MASP strategy may in principle be easily extended to craft other solution-printed perovskite-based optoelectronics.

  11. Techno-economic analysis of large-scale integration of solar power plants in the European grid

    Energy Technology Data Exchange (ETDEWEB)

    Tielens, Pieter; Ergun, Hakan; Hertem, Dirk van [Katholieke Universiteit Leuven (Belgium). Electrical Engineering Dept.

    2012-07-01

    In this paper different options to connect large solar power plants in North Africa to the European power system are compared from a transmission system investment point of view. Three different possible DC connections from Tunisia to Italy are investigated from a cost-based perspective. In the second part of the paper, the impact of the power fluctuations from CSP and PV power plants on the frequency control is examined in a qualitative manner. It is shown that the frequency response mainly depends on the amount of PV installed and the inertia present in the grid. The results of the simulations give a first estimation of the maximum amount of PV integration in the Tunisian grid without reaching certain frequency limits after a sudden power fluctuation. (orig.)

  12. Development of an industrialized space-frame system for the support of medium to large solar collector arrays

    Energy Technology Data Exchange (ETDEWEB)

    1982-11-01

    A low-cost industrialized space-frame system suitable for the economical support of medium to large solar collector arrays was designed following a study of building types, collector interface conditions, structural design requirements, and market and procurement factors. The system consists of a series of welded truss modular sections which may be bolted together in the field to create a support structure with a span capability up to 25 m, thus minimizing expensive structural beams and roof penetrations. Collectors can be readily attached to top and bottom channels. The system meets all current government specifications for collector support. A full-size prototype was built to prove the concept and identify any fabrication and on-site assembly problems. Collectors were attached to test collector interface conditions, and a manufacturing strategy developed. 24 figs., 3 tabs.

  13. Large-scale and Long-duration Simulation of a Multi-stage Eruptive Solar Event

    Science.gov (United States)

    Jiang, chaowei; Hu, Qiang; Wu, S. T.

    2015-04-01

    We employ a data-driven 3D MHD active region evolution model by using the Conservation Element and Solution Element (CESE) numerical method. This newly developed model retains the full MHD effects, allowing time-dependent boundary conditions and time evolution studies. The time-dependent simulation is driven by measured vector magnetograms and the method of MHD characteristics on the bottom boundary. We have applied the model to investigate the coronal magnetic field evolution of AR11283 which was characterized by a pre-existing sigmoid structure in the core region and multiple eruptions, both in relatively small and large scales. We have succeeded in producing the core magnetic field structure and the subsequent eruptions of flux-rope structures (see https://dl.dropboxusercontent.com/u/96898685/large.mp4 for an animation) as the measured vector magnetograms on the bottom boundary evolve in time with constant flux emergence. The whole process, lasting for about an hour in real time, compares well with the corresponding SDO/AIA and coronagraph imaging observations. From these results, we show the capability of the model, largely data-driven, that is able to simulate complex, topological, and highly dynamic active region evolutions. (We acknowledge partial support of NSF grants AGS 1153323 and AGS 1062050, and data support from SDO/HMI and AIA teams).

  14. Solar Energy Potential Assessment on Rooftops and Facades in Large Built Environments Based on LiDAR Data, Image Processing, and Cloud Computing. Methodological Background, Application, and Validation in Geneva (Solar Cadaster

    Directory of Open Access Journals (Sweden)

    Gilles Desthieux

    2018-03-01

    Full Text Available The paper presents the core methodology for assessing solar radiation and energy production on building rooftops and vertical facades (still rarely considered of the inner-city. This integrated tool is based on the use of LiDAR, 2D and 3D cadastral data. Together with solar radiation and astronomical models, it calculates the global irradiance for a set of points located on roofs, ground, and facades. Although the tool takes simultaneously roofs, ground, and facades, different methods of shadow casting are applied. Shadow casting on rooftops is based on image processing techniques. On the other hand, the assessment on facade involves first to create and interpolate points along the facades and then to implement a point-by-point shadow casting routine. The paper is structured in five parts: (i state of the art on the use of 3D GIS and automated processes in assessing solar radiation in the built environment, (ii overview on the methodological framework used in the paper, (iii detailed presentation of the method proposed for solar modeling and shadow casting, in particular by introducing an innovative approach for modeling the sky view factor (SVF, (iv demonstration of the solar model introduced in this paper through applications in Geneva’s building roofs (solar cadaster and facades, (v validation of the solar model in some Geneva’s spots, focusing especially on two distinct comparisons: solar model versus fisheye catchments on partially inclined surfaces (roof component; solar model versus photovoltaic simulation tool PVSyst on vertical surfaces (facades. Concerning the roof component, validation results emphasize global sensitivity related to the density of light sources on the sky vault to model the SVF. The low dense sky model with 145 light sources gives satisfying results, especially when processing solar cadasters in large urban areas, thus allowing to save computation time. In the case of building facades, introducing weighting factor

  15. The large scale and long term evolution of the solar wind speed distribution and high speed streams

    International Nuclear Information System (INIS)

    Intriligator, D.S.

    1977-01-01

    The spatial and temporal evolution of the solar wind speed distribution and of high speed streams in the solar wind are examined. Comparisons of the solar wind streaming speeds measured at Earth, Pioneer 11, and Pioneer 10 indicate that between 1 AU and 6.4 AU the solar wind speed distributions are narrower (i.e. the 95% value minus the 5% value of the solar wind streaming speed is less) at extended heliocentric distances. These observations are consistent with one exchange of momentum in the solar wind between high speed streams and low speed streams as they propagate outward from the Sun. Analyses of solar wind observations at 1 AU from mid 1964 through 1973 confirm the earlier results reported by Intriligator (1974) that there are statistically significant variations in the solar wind in 1968 and 1969, years of solar maximum. High speed stream parameters show that the number of high speed streams in the solar wind in 1968 and 1969 is considerably more than the predicted yearly average, and in 1965 and 1972 less. Histograms of solar wind speed from 1964 through 1973 indicate that in 1968 there was the highest percentage of elevated solar wind speeds and in 1965 and 1972 the lowest. Studies by others also confirm these results although the respective authors did not indicate this fact. The duration of the streams and the histograms for 1973 imply a shifting in the primary stream source. (Auth.)

  16. Optimizing porphyrins for dye sensitized solar cells using large-scale ab initio calculations

    DEFF Research Database (Denmark)

    Ørnsø, Kristian Baruël; Pedersen, Christian S.; García Lastra, Juan Maria

    2014-01-01

    different side and anchoring groups. Based on the calculated frontier orbital energies and optical gaps we quantify the energy level alignment with the TiO2 conduction band and different redox mediators. An analysis of the energy level-structure relationship reveals a significant structural diversity among...... the dyes with the highest level alignment quality, demonstrating the large degree of flexibility in porphyrin dye design. As a specific example of dye optimization, we show that the level alignment of the high efficiency record dye YD2-o-C8 [Yella et al., Science, 2011, 334, 629-634] can be significantly...

  17. Large CZTS Nanoparticles Synthesized by Hot-Injection for Thin Film Solar Cells

    DEFF Research Database (Denmark)

    Engberg, Sara Lena Josefin; Lam, Yeng Ming; Schou, Jørgen

    can be carried out in order to isolate the desired particle sizes, and films will be deposited through wet-chemical means. Mixing large NPs with small NPs can also improve the film-quality as a result of densification at the optimal packing density. The films are characterized by scanning electron...... microscopy (SEM) as well as other surface characterization techniques. Our first photovoltaic device consisting of soda lime glass/Mo/CZTS/CdS/ZnO has been built from doctor blading of approx. 20 nm Cu2ZnSnS4 NPs in octanethiol, and annealed in Se-atmosphere. It had an efficiency of 1.4%....

  18. Electro-spray deposition of a mesoporous TiO2 charge collection layer: toward large scale and continuous production of high efficiency perovskite solar cells.

    Science.gov (United States)

    Kim, Min-cheol; Kim, Byeong Jo; Yoon, Jungjin; Lee, Jin-wook; Suh, Dongchul; Park, Nam-gyu; Choi, Mansoo; Jung, Hyun Suk

    2015-12-28

    The spin-coating method, which is widely used for thin film device fabrication, is incapable of large-area deposition or being performed continuously. In perovskite hybrid solar cells using CH(3)NH(3)PbI(3) (MAPbI(3)), large-area deposition is essential for their potential use in mass production. Prior to replacing all the spin-coating process for fabrication of perovskite solar cells, herein, a mesoporous TiO(2) electron-collection layer is fabricated by using the electro-spray deposition (ESD) system. Moreover, impedance spectroscopy and transient photocurrent and photovoltage measurements reveal that the electro-sprayed mesoscopic TiO(2) film facilitates charge collection from the perovskite. The series resistance of the perovskite solar cell is also reduced owing to the highly porous nature of, and the low density of point defects in, the film. An optimized power conversion efficiency of 15.11% is achieved under an illumination of 1 sun; this efficiency is higher than that (13.67%) of the perovskite solar cell with the conventional spin-coated TiO(2) films. Furthermore, the large-area coating capability of the ESD process is verified through the coating of uniform 10 × 10 cm(2) TiO(2) films. This study clearly shows that ESD constitutes therefore a viable alternative for the fabrication of high-throughput, large-area perovskite solar cells.

  19. A CAD-CAM prosthodontic option and gingival zenith position for a rotated maxillary right central incisor: An evaluation

    Directory of Open Access Journals (Sweden)

    Mukesh Singhal

    2012-01-01

    Conclusion: Digital imaging provides an immediate treatment option for the patients. Software also provides an interim aid, for the clinician as well as technician, in the form of two-dimensional photographs. CAD-CAM is entirely a helping instrument against the conservative prosthetic options and gingival zenith position for a rotated central incisor. It helps in patient education and in motivation.

  20. Changes in the High-Latitude Topside Ionospheric Vertical Electron-Density Profiles in Response to Solar-Wind Perturbations During Large Magnetic Storms

    Science.gov (United States)

    Benson, Robert F.; Fainberg, Joseph; Osherovich, Vladimir; Truhlik, Vladimir; Wang, Yongli; Arbacher, Becca

    2011-01-01

    The latest results from an investigation to establish links between solar-wind and topside-ionospheric parameters will be presented including a case where high-latitude topside electron-density Ne(h) profiles indicated dramatic rapid changes in the scale height during the main phase of a large magnetic storm (Dst wind data obtained from the NASA OMNIWeb database indicated that the magnetic storm was due to a magnetic cloud. This event is one of several large magnetic storms being investigated during the interval from 1965 to 1984 when both solar-wind and digital topside ionograms, from either Alouette-2, ISIS-1, or ISIS-2, are potentially available.

  1. Trifluoromethyl-Substituted Large Band-Gap Polytriphenylamines for Polymer Solar Cells with High Open-Circuit Voltages

    Directory of Open Access Journals (Sweden)

    Shuwang Yi

    2018-01-01

    Full Text Available Two large band-gap polymers (PTPACF and PTPA2CF based on polytriphenylamine derivatives with the introduction of electron-withdrawing trifluoromethyl groups were designed and prepared by Suzuki polycondensation reaction. The chemical structures, thermal, optical and electrochemical properties were characterized in detail. From the UV-visible absorption spectra, the PTPACF and PTPA2CF showed the optical band gaps of 2.01 and 2.07 eV, respectively. The cyclic voltammetry (CV measurement displayed the deep highest occupied molecular orbital (HOMO energy levels of −5.33 and −5.38 eV for PTPACF and PTPA2CF, respectively. The hole mobilities, determined by field-effect transistor characterization, were 2.5 × 10−3 and 1.1 × 10−3 cm2 V−1 S−1 for PTPACF and PTPA2CF, respectively. The polymer solar cells (PSCs were tested under the conventional device structure of ITO/PEDOT:PSS/polymer:PC71BM/PFN/Al. All of the PSCs showed the high open circuit voltages (Vocs with the values approaching 1 V. The PTPACF and PTPA2CF based PSCs gave the power conversion efficiencies (PCEs of 3.24% and 2.40%, respectively. Hence, it is a reliable methodology to develop high-performance large band-gap polymer donors with high Vocs through the feasible side-chain modification.

  2. Probabilistic Solar Wind Forecasting Using Large Ensembles of Near‐Sun Conditions With a Simple One‐Dimensional “Upwind” Scheme

    Science.gov (United States)

    Riley, Pete

    2017-01-01

    Abstract Long lead‐time space‐weather forecasting requires accurate prediction of the near‐Earth solar wind. The current state of the art uses a coronal model to extrapolate the observed photospheric magnetic field to the upper corona, where it is related to solar wind speed through empirical relations. These near‐Sun solar wind and magnetic field conditions provide the inner boundary condition to three‐dimensional numerical magnetohydrodynamic (MHD) models of the heliosphere out to 1 AU. This physics‐based approach can capture dynamic processes within the solar wind, which affect the resulting conditions in near‐Earth space. However, this deterministic approach lacks a quantification of forecast uncertainty. Here we describe a complementary method to exploit the near‐Sun solar wind information produced by coronal models and provide a quantitative estimate of forecast uncertainty. By sampling the near‐Sun solar wind speed at a range of latitudes about the sub‐Earth point, we produce a large ensemble (N = 576) of time series at the base of the Sun‐Earth line. Propagating these conditions to Earth by a three‐dimensional MHD model would be computationally prohibitive; thus, a computationally efficient one‐dimensional “upwind” scheme is used. The variance in the resulting near‐Earth solar wind speed ensemble is shown to provide an accurate measure of the forecast uncertainty. Applying this technique over 1996–2016, the upwind ensemble is found to provide a more “actionable” forecast than a single deterministic forecast; potential economic value is increased for all operational scenarios, but particularly when false alarms are important (i.e., where the cost of taking mitigating action is relatively large). PMID:29398982

  3. The Large-scale Coronal Structure of the 2017 August 21 Great American Eclipse: An Assessment of Solar Surface Flux Transport Model Enabled Predictions and Observations

    Science.gov (United States)

    Nandy, Dibyendu; Bhowmik, Prantika; Yeates, Anthony R.; Panda, Suman; Tarafder, Rajashik; Dash, Soumyaranjan

    2018-01-01

    On 2017 August 21, a total solar eclipse swept across the contiguous United States, providing excellent opportunities for diagnostics of the Sun’s corona. The Sun’s coronal structure is notoriously difficult to observe except during solar eclipses; thus, theoretical models must be relied upon for inferring the underlying magnetic structure of the Sun’s outer atmosphere. These models are necessary for understanding the role of magnetic fields in the heating of the corona to a million degrees and the generation of severe space weather. Here we present a methodology for predicting the structure of the coronal field based on model forward runs of a solar surface flux transport model, whose predicted surface field is utilized to extrapolate future coronal magnetic field structures. This prescription was applied to the 2017 August 21 solar eclipse. A post-eclipse analysis shows good agreement between model simulated and observed coronal structures and their locations on the limb. We demonstrate that slow changes in the Sun’s surface magnetic field distribution driven by long-term flux emergence and its evolution governs large-scale coronal structures with a (plausibly cycle-phase dependent) dynamical memory timescale on the order of a few solar rotations, opening up the possibility for large-scale, global corona predictions at least a month in advance.

  4. The zenithal 4-m International Liquid Mirror Telescope: a unique facility for supernova studies

    Science.gov (United States)

    Kumar, Brajesh; Pandey, Kanhaiya L.; Pandey, S. B.; Hickson, P.; Borra, E. F.; Anupama, G. C.; Surdej, J.

    2018-05-01

    The 4-m International Liquid Mirror Telescope (ILMT) will soon become operational at the newly developed Devasthal observatory near Nainital (Uttarakhand, India). Coupled with a 4k × 4k pixels CCD detector and TDI optical corrector, it will reach approximately 22.8, 22.3, and 21.4 mag in the g΄, r΄, and i΄ spectral bands, respectively, in a single scan. The limiting magnitudes can be further improved by co-adding the consecutive night images in particular filters. The uniqueness to observe the same sky region by looking towards the zenith direction every night makes the ILMT a unique instrument to detect new supernovae (SNe) by applying the image subtraction technique. High cadence (˜24 h) observations will help to construct dense sampling multi-band SNe light curves. We discuss the importance of the ILMT facility in the context of SNe studies. Considering the various plausible cosmological parameters and observational constraints, we perform detailed calculations of the expected SNe rate that can be detected with the ILMT in different spectral bands.

  5. Data assimilation of GNSS zenith total delays from a Nordic processing centre

    Science.gov (United States)

    Lindskog, Magnus; Ridal, Martin; Thorsteinsson, Sigurdur; Ning, Tong

    2017-11-01

    Atmospheric moisture-related information estimated from Global Navigation Satellite System (GNSS) ground-based receiver stations by the Nordic GNSS Analysis Centre (NGAA) have been used within a state-of-the-art kilometre-scale numerical weather prediction system. Different processing techniques have been implemented to derive the moisture-related GNSS information in the form of zenith total delays (ZTDs) and these are described and compared. In addition full-scale data assimilation and modelling experiments have been carried out to investigate the impact of utilizing moisture-related GNSS data from the NGAA processing centre on a numerical weather prediction (NWP) model initial state and on the ensuing forecast quality. The sensitivity of results to aspects of the data processing, station density, bias-correction and data assimilation have been investigated. Results show benefits to forecast quality when using GNSS ZTD as an additional observation type. The results also show a sensitivity to thinning distance applied for GNSS ZTD observations but not to modifications to the number of predictors used in the variational bias correction applied. In addition, it is demonstrated that the assimilation of GNSS ZTD can benefit from more general data assimilation enhancements and that there is an interaction of GNSS ZTD with other types of observations used in the data assimilation. Future plans include further investigation of optimal thinning distances and application of more advanced data assimilation techniques.

  6. Estimating Zenith Tropospheric Delays from BeiDou Navigation Satellite System Observations

    Directory of Open Access Journals (Sweden)

    Xin Sui

    2013-04-01

    Full Text Available The GNSS derived Zenith Tropospheric Delay (ZTD plays today a very critical role in meteorological study and weather forecasts, as ZTDs of thousands of GNSS stations are operationally assimilated into numerical weather prediction models. Recently, the Chinese BeiDou Navigation Satellite System (BDS was officially announced to provide operational services around China and its neighborhood and it was demonstrated to be very promising for precise navigation and positioning. In this contribution, we concentrate on estimating ZTD using BDS observations to assess its capacity for troposphere remote sensing. A local network which is about 250 km from Beijing and comprised of six stations equipped with GPS- and BDS-capable receivers is utilized. Data from 5 to 8 November 2012 collected on the network is processed in network mode using precise orbits and in Precise Point Positioning mode using precise orbits and clocks. The precise orbits and clocks are generated from a tracking network with most of the stations in China and several stations around the world. The derived ZTDs are compared with that estimated from GPS data using the final products of the International GNSS Service (IGS. The comparison shows that the bias and the standard deviation of the ZTD differences are about 2 mm and 5 mm, respectively, which are very close to the differences of GPS ZTD estimated using different software packages.

  7. Boron-doped zinc oxide thin films for large-area solar cells grown by metal organic chemical vapor deposition

    International Nuclear Information System (INIS)

    Chen, X.L.; Xu, B.H.; Xue, J.M.; Zhao, Y.; Wei, C.C.; Sun, J.; Wang, Y.; Zhang, X.D.; Geng, X.H.

    2007-01-01

    Boron-doped zinc oxide (ZnO:B) films were grown by metal organic chemical vapor deposition using diethylzinc (DEZn), and H 2 O as reactant gases and diborane (B 2 H 6 ) as an n-type dopant gas. The structural, electrical and optical properties of ZnO films doped at different B 2 H 6 flow rates were investigated. X-ray diffraction spectra and scanning electron microscopy images indicate that boron-doping plays an important role on the microstructure of ZnO films, which induced textured morphology. With optimized conditions, low sheet resistance (∼ 30 Ω/□), high transparency (> 85% in the visible light and infrared range) and high mobility (17.8 cm 2 V -1 s -1 ) were obtained for 700-nm ZnO:B films deposited on 20 cm x 20 cm glass substrates at the temperature of 443 K. After long-term exposure in air, the ZnO:B films also showed a better electrical stability than the un-doped samples. With the application of ZnO:B/Al back contacts, the short circuit current density was effectively enhanced by about 3 mA/cm 2 for a small area a-Si:H cell and a high efficiency of 9.1% was obtained for a large-area (20 cm x 20 cm) a-Si solar module

  8. Financial return for government support of large-scale thin-film solar photovoltaic manufacturing in Canada

    International Nuclear Information System (INIS)

    Branker, K.; Pearce, J.M.

    2010-01-01

    As the Ontario government has recognized that solar photovoltaic (PV) energy conversion is a solution to satisfying energy demands while reducing the adverse anthropogenic impacts on the global environment that compromise social welfare, it has begun to generate policy to support financial incentives for PV. This paper provides a financial analysis for investment in a 1 GW per year turnkey amorphous silicon PV manufacturing plant. The financial benefits for both the provincial and federal governments were quantified for: (i) full construction subsidy, (ii) construction subsidy and sale, (iii) partially subsidize construction, (iv) a publicly owned plant, (v) loan guarantee for construction, and (vi) an income tax holiday. Revenues for the governments are derived from: taxation (personal, corporate, and sales), sales of panels in Ontario, and saved health, environmental and economic costs associated with offsetting coal-fired electricity. Both governments enjoyed positive cash flows from these investments in less than 12 years and in many of the scenarios both governments earned well over 8% on investments from 100 s of millions to $2.4 billion. The results showed that it is in the financial best interest of both the Ontario and Canadian federal governments to implement aggressive fiscal policy to support large-scale PV manufacturing.

  9. Dynamical Orientation of Large Molecules on Oxide Surfaces and its Implications for Dye-Sensitized Solar Cells

    KAUST Repository

    Brennan, Thomas P.

    2013-11-12

    A dual experimental-computational approach utilizing near-edge X-ray absorption fine structure (NEXAFS) spectroscopy and density functional theory-molecular dynamics (DFT-MD) is presented for determining the orientation of a large adsorbate on an oxide substrate. A system of interest in the field of dye-sensitized solar cells is studied: an organic cyanoacrylic acid-based donor-π-acceptor dye (WN1) bound to anatase TiO2. Assessment of nitrogen K-edge NEXAFS spectra is supported by calculations of the electronic structure that indicate energetically discrete transitions associated with the two π systems of the C-N triple bond in the cyanoacrylic acid portion of the dye. Angle-resolved NEXAFS spectra are fitted to determine the orientation of these two orbital systems, and the results indicate an upright orientation of the adsorbed dye, 63 from the TiO2 surface plane. These experimental results are then compared to computational studies of the WN1 dye on an anatase (101) TiO2 slab. The ground state structure obtained from standard DFT optimization is less upright (45 from the surface) than the NEXAFS results. However, DFT-MD simulations, which provide a more realistic depiction of the dye at room temperature, exhibit excellent agreement - within 2 on average - with the angles determined via NEXAFS, demonstrating the importance of accounting for the dynamic nature of adsorbate-substrate interactions and DFT-MD\\'s powerful predictive abilities. © 2013 American Chemical Society.

  10. Dynamical Orientation of Large Molecules on Oxide Surfaces and its Implications for Dye-Sensitized Solar Cells

    KAUST Repository

    Brennan, Thomas P.; Tanskanen, Jukka T.; Bakke, Jonathan R.; Nguyen, William H.; Nordlund, Dennis; Toney, Michael F.; McGehee, Michael D.; Sellinger, Alan; Bent, Stacey F.

    2013-01-01

    A dual experimental-computational approach utilizing near-edge X-ray absorption fine structure (NEXAFS) spectroscopy and density functional theory-molecular dynamics (DFT-MD) is presented for determining the orientation of a large adsorbate on an oxide substrate. A system of interest in the field of dye-sensitized solar cells is studied: an organic cyanoacrylic acid-based donor-π-acceptor dye (WN1) bound to anatase TiO2. Assessment of nitrogen K-edge NEXAFS spectra is supported by calculations of the electronic structure that indicate energetically discrete transitions associated with the two π systems of the C-N triple bond in the cyanoacrylic acid portion of the dye. Angle-resolved NEXAFS spectra are fitted to determine the orientation of these two orbital systems, and the results indicate an upright orientation of the adsorbed dye, 63 from the TiO2 surface plane. These experimental results are then compared to computational studies of the WN1 dye on an anatase (101) TiO2 slab. The ground state structure obtained from standard DFT optimization is less upright (45 from the surface) than the NEXAFS results. However, DFT-MD simulations, which provide a more realistic depiction of the dye at room temperature, exhibit excellent agreement - within 2 on average - with the angles determined via NEXAFS, demonstrating the importance of accounting for the dynamic nature of adsorbate-substrate interactions and DFT-MD's powerful predictive abilities. © 2013 American Chemical Society.

  11. Vapor and healing treatment for CH3NH3PbI3-xClx films toward large-area perovskite solar cells

    Science.gov (United States)

    Gouda, Laxman; Gottesman, Ronen; Tirosh, Shay; Haltzi, Eynav; Hu, Jiangang; Ginsburg, Adam; Keller, David A.; Bouhadana, Yaniv; Zaban, Arie

    2016-03-01

    Hybrid methyl-ammonium lead trihalide perovskites are promising low-cost materials for use in solar cells and other optoelectronic applications. With a certified photovoltaic conversion efficiency record of 20.1%, scale-up for commercial purposes is already underway. However, preparation of large-area perovskite films remains a challenge, and films of perovskites on large electrodes suffer from non-uniform performance. Thus, production and characterization of the lateral uniformity of large-area films is a crucial step towards scale-up of devices. In this paper, we present a reproducible method for improving the lateral uniformity and performance of large-area perovskite solar cells (32 cm2). The method is based on methyl-ammonium iodide (MAI) vapor treatment as a new step in the sequential deposition of perovskite films. Following the MAI vapor treatment, we used high throughput techniques to map the photovoltaic performance throughout the large-area device. The lateral uniformity and performance of all photovoltaic parameters (Voc, Jsc, Fill Factor, Photo-conversion efficiency) increased, with an overall improved photo-conversion efficiency of ~100% following a vapor treatment at 140 °C. Based on XRD and photoluminescence measurements, We propose that the MAI treatment promotes a ``healing effect'' to the perovskite film which increases the lateral uniformity across the large-area solar cell. Thus, the straightforward MAI vapor treatment is highly beneficial for large scale commercialization of perovskite solar cells, regardless of the specific deposition method.Hybrid methyl-ammonium lead trihalide perovskites are promising low-cost materials for use in solar cells and other optoelectronic applications. With a certified photovoltaic conversion efficiency record of 20.1%, scale-up for commercial purposes is already underway. However, preparation of large-area perovskite films remains a challenge, and films of perovskites on large electrodes suffer from non

  12. Solar thermal barometer. 12 million M2 installed in europe

    International Nuclear Information System (INIS)

    Anon.

    2002-01-01

    European thermal solar has once again reached its zenith. The difficult times of 1985-1995 are now a thing of the past. The best proof is the very good results of 2001 that show figures in significant progression with respect to those of the year 2000. 1480 320 m 2 . This is now the new record to beat in terms of the annual volume of thermal solar collector installation in the European Union. (author)

  13. The solar noise barrier project: 1. Effect of incident light orientation on the performance of a large-scale luminescent solar concentrator noise barrier

    NARCIS (Netherlands)

    Kanellis, M.; de Jong, M.; Slooff, L.H.; Debije, M.G.

    2017-01-01

    In this work we describe the relative performance of the largest luminescent solar concentrator (LSC) constructed to date. Comparisons are made for performance of North/South and East/West facing panels during a sunny day. It is shown that the East/West panels display much more varied performance

  14. Retrieval of stratospheric and tropospheric BrO profiles and columns using ground-based zenith-sky DOAS observations at Harestua, 60° N

    Directory of Open Access Journals (Sweden)

    J. A. Pyle

    2007-09-01

    Full Text Available A profiling algorithm based on the optimal estimation method is applied to ground-based zenith-sky UV-visible measurements from Harestua, Southern Norway (60° N, 11° E in order to retrieve BrO vertical profiles. The sensitivity of the zenith-sky observations to the tropospheric BrO detection is increased by using for the spectral analysis a fixed reference spectrum corresponding to clear-sky noon summer conditions. The information content and retrieval errors are characterized and it is shown that the retrieved stratospheric profiles and total columns are consistent with correlative balloon and satellite observations, respectively. Tropospheric BrO columns are derived from profiles retrieved at 80° solar zenith angle during sunrise and sunset for the 2000–2006 period. They show a marked seasonality with mean column value ranging from 1.52±0.62×1013 molec/cm² in late winter/early spring to 0.92±0.38×1013 molec/cm² in summer, which corresponds to 1.0±0.4 and 0.6±0.2 pptv, respectively, if we assume that BrO is uniformly mixed in the troposphere. These column values are also consistent with previous estimates made from balloon, satellite, and other ground-based observations. Daytime (10:30 LT tropospheric BrO columns are compared to the p-TOMCAT 3-D tropospheric chemical transport model (CTM for the 2002–2003 period. p-TOMCAT shows a good agreement with the retrieved columns except in late winter/early spring where an underestimation by the model is obtained. This finding could be explained by the non-inclusion of sea-ice bromine sources in the current version of p-TOMCAT. Therefore the model cannot reproduce the possible transport of air-masses with enhanced BrO concentration due to bromine explosion events from the polar region to Harestua. The daytime stratospheric BrO columns are compared to the SLIMCAT stratospheric 3-D-CTM. The model run used in this study, which assumes 21.2 pptv for the Bry loading (15 pptv for long

  15. Analisis Six Sigma pada Produk Casing Pompa sebagai Metode Perbaikan Kualitas (Studi Kasus: PT. Zenith Allmart Precisindo)

    OpenAIRE

    Haryono, Haryono; Rakasiwi, Hafiedza Pradana

    2014-01-01

    Pada Februari 2014, produk baja terbanyak yang diproduksi PT. Zenith Allmart Precisindo (ZAP) adalah casing pompa dengan reject sebesar 3,35%, padahal target maksimal reject 2% per bulan, ada gap sebesar 1,35%. Analisis DMAIC Six Sigma dilaksanakan untuk mengurangi persentase reject. Pada define, ditentukan project charter, peta proses produksi, dan SIPOC diagram. Dari SIPOC diagram ditentukan 10 CTQ. Pada fase measure dilakukan attribute agreement analysis untuk QC, hasilnya adalah repeabili...

  16. A Simple Parameterization of the Cosmic-Ray Muon Momentum Spectra at the Surface as a Function of Zenith Angle

    OpenAIRE

    Reyna, D.

    2006-01-01

    The designs of many neutrino experiments rely on calculations of the background rates arising from cosmic-ray muons at shallow depths. Understanding the angular dependence of low momentum cosmic-ray muons at the surface is necessary for these calculations. Heuristically, from examination of the data, a simple parameterization is proposed, based on a straighforward scaling variable. This in turn, allows a universal calculation of the differential muon intensity at the surface for all zenith an...

  17. Implementation of a large-scale solar photovoltaic system at a higher education institution in Illinois, USA

    Directory of Open Access Journals (Sweden)

    Jin H. Jo

    2017-01-01

    Full Text Available Solar energy has several environmental, economic, and educational benefits for college campuses, but it is difficult for state schools to find funding for these projects. This study shows that a solar photovoltaic (PV system on Illinois State University’s (ISU campus is technically and financially feasible. While there have been several solar feasibility studies of higher education institutions in USA, there has been a lack of in depth financial analysis. We conducted solar site assessments on five potential locations on campus, used a solar energy performance model to analyze the technical feasibility of each location, and performed a financial assessment using a professional PV financial modeling tool to compare different financing options. Our results show that three sites on campus can be used to develop a combined solar PV system of one megawatt. Both direct and third-party ownership models are financially feasible for this combined system. Our findings can be replicable as a case study for future solar PV system development on college campuses.

  18. Solar powered oxygen systems in remote health centers in Papua New Guinea: a large scale implementation effectiveness trial.

    Science.gov (United States)

    Duke, Trevor; Hwaihwanje, Ilomo; Kaupa, Magdalynn; Karubi, Jonah; Panauwe, Doreen; Sa'avu, Martin; Pulsan, Francis; Prasad, Peter; Maru, Freddy; Tenambo, Henry; Kwaramb, Ambrose; Neal, Eleanor; Graham, Hamish; Izadnegahdar, Rasa

    2017-06-01

    Pneumonia is the largest cause of child deaths in Papua New Guinea (PNG), and hypoxaemia is the major complication causing death in childhood pneumonia, and hypoxaemia is a major factor in deaths from many other common conditions, including bronchiolitis, asthma, sepsis, malaria, trauma, perinatal problems, and obstetric emergencies. A reliable source of oxygen therapy can reduce mortality from pneumonia by up to 35%. However, in low and middle income countries throughout the world, improved oxygen systems have not been implemented at large scale in remote, difficult to access health care settings, and oxygen is often unavailable at smaller rural hospitals or district health centers which serve as the first point of referral for childhood illnesses. These hospitals are hampered by lack of reliable power, staff training and other basic services. We report the methodology of a large implementation effectiveness trial involving sustainable and renewable oxygen and power systems in 36 health facilities in remote rural areas of PNG. The methodology is a before-and after evaluation involving continuous quality improvement, and a health systems approach. We describe this model of implementation as the considerations and steps involved have wider implications in health systems in other countries. The implementation steps include: defining the criteria for where such an intervention is appropriate, assessment of power supplies and power requirements, the optimal design of a solar power system, specifications for oxygen concentrators and other oxygen equipment that will function in remote environments, installation logistics in remote settings, the role of oxygen analyzers in monitoring oxygen concentrator performance, the engineering capacity required to sustain a program at scale, clinical guidelines and training on oxygen equipment and the treatment of children with severe respiratory infection and other critical illnesses, program costs, and measurement of processes and

  19. Observed Spectral Invariant Behavior of Zenith Radiance in the Transition Zone Between Cloud-Free and Cloudy Regions

    Science.gov (United States)

    Marshak, A.; Knyazikhin, Y.; Chiu, C.; Wiscombe, W.

    2010-01-01

    The Atmospheric Radiation Measurement Program's (ARM) new Shortwave Spectrometer (SWS) looks straight up and measures zenith radiance at 418 wavelengths between 350 and 2200 nm. Because of its 1-sec sampling resolution, the SWS provides a unique capability to study the transition zone between cloudy and clear sky areas. A surprising spectral invariant behavior is found between ratios of zenith radiance spectra during the transition from cloudy to cloud-free atmosphere. This behavior suggests that the spectral signature of the transition zone is a linear mixture between the two extremes (definitely cloudy and definitely clear). The weighting function of the linear mixture is found to be a wavelength-independent characteristic of the transition zone. It is shown that the transition zone spectrum is fully determined by this function and zenith radiance spectra of clear and cloudy regions. This new finding may help us to better understand and quantify such physical phenomena as humidification of aerosols in the relatively moist cloud environment and evaporation and activation of cloud droplets.

  20. Effect of titanium dioxide (TiO{sub 2}) on largely improving solar reflectance and cooling property of high density polyethylene (HDPE) by influencing its crystallization behavior

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Shichao; Zhang, Jun, E-mail: zhangjun@njtech.edu.cn

    2014-12-25

    Highlights: • HDPE/TiO{sub 2} composites have more perfect crystal structure. • Refractive index is the key factor affecting the final solar reflectance. • HDPE/TiO{sub 2} composites can achieve high solar reflectance. • The real cooling property is in accordance with solar reflectance. - Abstract: In this study, the different crystal forms of titanium dioxide (TiO{sub 2}) were added into high density polyethylene (HDPE) to fabricate cool material. Crystal structure, crystallization behavior, crystal morphology were investigated by wide angle X-ray diffraction (WAXD), differential scanning calorimetry (DSC) and polarized optical microscope (POM). Scanning electron microscope (SEM) was applied to observe dispersion of TiO{sub 2} particles in the HDPE matrix and the cross section morphology. The solar reflectance and actual cooling property were evaluated by UV–Vis–NIR spectrometer and a self-designed device. By adding TiO{sub 2} particles into HDPE matrix, the polymer chain could crystallize into more perfect and thermal stable lamella. The presence of TiO{sub 2} particles dramatically increased the number of nucleation site therefore decreased the crystal size. The subsequent solar reflectance was related to the degree of crystallinity, the spherulite size of HDPE, refractive index, and distribution of TiO{sub 2} particles in HDPE matrix. It was found the rutile TiO{sub 2} could largely improve the total solar reflectance from 28.2% to 51.1%. Finally, the temperature test showed that the composites had excellent cooling property, which was in accordance with solar reflectance result.

  1. Effect of titanium dioxide (TiO2) on largely improving solar reflectance and cooling property of high density polyethylene (HDPE) by influencing its crystallization behavior

    International Nuclear Information System (INIS)

    Wang, Shichao; Zhang, Jun

    2014-01-01

    Highlights: • HDPE/TiO 2 composites have more perfect crystal structure. • Refractive index is the key factor affecting the final solar reflectance. • HDPE/TiO 2 composites can achieve high solar reflectance. • The real cooling property is in accordance with solar reflectance. - Abstract: In this study, the different crystal forms of titanium dioxide (TiO 2 ) were added into high density polyethylene (HDPE) to fabricate cool material. Crystal structure, crystallization behavior, crystal morphology were investigated by wide angle X-ray diffraction (WAXD), differential scanning calorimetry (DSC) and polarized optical microscope (POM). Scanning electron microscope (SEM) was applied to observe dispersion of TiO 2 particles in the HDPE matrix and the cross section morphology. The solar reflectance and actual cooling property were evaluated by UV–Vis–NIR spectrometer and a self-designed device. By adding TiO 2 particles into HDPE matrix, the polymer chain could crystallize into more perfect and thermal stable lamella. The presence of TiO 2 particles dramatically increased the number of nucleation site therefore decreased the crystal size. The subsequent solar reflectance was related to the degree of crystallinity, the spherulite size of HDPE, refractive index, and distribution of TiO 2 particles in HDPE matrix. It was found the rutile TiO 2 could largely improve the total solar reflectance from 28.2% to 51.1%. Finally, the temperature test showed that the composites had excellent cooling property, which was in accordance with solar reflectance result

  2. Global model of zenith tropospheric delay proposed based on EOF analysis

    Science.gov (United States)

    Sun, Langlang; Chen, Peng; Wei, Erhu; Li, Qinzheng

    2017-07-01

    Tropospheric delay is one of the main error budgets in Global Navigation Satellite System (GNSS) measurements. Many empirical correction models have been developed to compensate this delay, and models which do not require meteorological parameters have received the most attention. This study established a global troposphere zenith total delay (ZTD) model, called Global Empirical Orthogonal Function Troposphere (GEOFT), based on the empirical orthogonal function (EOF, also known as geographically weighted PCAs) analysis method and the Global Geodetic Observing System (GGOS) Atmosphere data from 2012 to 2015. The results showed that ZTD variation could be well represented by the characteristics of the EOF base function Ek and associated coefficients Pk. Here, E1 mainly signifies the equatorial anomaly; E2 represents north-south asymmetry, and E3 and E4 reflects regional variation. Moreover, P1 mainly reflects annual and semiannual variation components; P2 and P3 mainly contains annual variation components, and P4 displays semiannual variation components. We validated the proposed GEOFT model using tropospheric delay data of GGOS ZTD grid data and the tropospheric product of the International GNSS Service (IGS) over the year 2016. The results showed that GEOFT model has high accuracy with bias and RMS of -0.3 and 3.9 cm, respectively, with respect to the GGOS ZTD data, and of -0.8 and 4.1 cm, respectively, with respect to the global IGS tropospheric product. The accuracy of GEOFT demonstrating that the use of the EOF analysis method to characterize ZTD variation is reasonable.

  3. Predictions of Tropospheric Zenithal Delay for South America : Seasonal Variability and Quality Evaluation

    Directory of Open Access Journals (Sweden)

    Luiz Augusto Toledo Machado

    2006-12-01

    Full Text Available The Zenithal Tropospheric Delay (Z TD is an important error source in the observable involved in the positioning methods using artificial satellite. Frequently, the Z TD influence in the positioning is minimized by applying empirical models. However, such models are not able to supply the precision required to some real time applications, such as navigation and steak out. In 2010 it will be implanted the new navigation and administration system of the air traffic, denominated CNS-ATM (Communication Navigation Surveillance - Air Traffic Management. In this new system the application of positioning techniques by satellites in the air traffic will be quite explored because they provide good precision in real time. The predictions of Z TD values from Numeric Weather Prediction (NWP, denominated dynamic modeling, is an alternative to model the atmospheric gases effects in the radio-frequency signals in real time. The Center for Weather Forecasting and Climate Studies (CPTEC has generated operationally prediction of Z TD values to South American Continent since March, 2004. The aims of the present paper are to investigate the Z TD seasonal variability and evaluate the quality of predicted Z TD values. One year of GPS data from Brazilian Continuous GPS Network (RBMC was used in this evaluation. The RMS values resulting from this evaluation were in the range of 4 to 11 cm. Considering the Z TDtemporal variability, the advantages provide by this modeling, the results obtained in this evaluation and the future improvements, this work shows that the dynamic modeling has great potential to become the most appropriate alternative to model Z TD in real time.

  4. Spectrum measurements in the ZENITH plutonium core 7 using a neutron chopper

    Energy Technology Data Exchange (ETDEWEB)

    Barclay, F R; Cameron, I R; Pitcher, H H.W.; Symons, C R [General Reactor Physics Division, Atomic Energy Establishment, Winfrith, Dorchester, Dorset (United Kingdom)

    1964-05-15

    As part of the experimental programme on the first plutonium loading of ZENITH (Core 7) a series of measurements was carried out with the neutron chopper on a beam emerging from the core centre. The general experimental programme on the two ZENITH plutonium cores has been covered elsewhere. Core 7 had a carbon/Pu239 atomic ratio of 2666 and a steel/Pu239 ratio of 76.8, giving an absorption cross-section at 2200 m/sec. of 0.31 barns/carbon atom. The fuel was in the form of 'spikes' of 0.020 in. thick Pu/Al alloy sheathed in 0.020 in. aluminium, the isotopic composition of the plutonium being 97.4% Pu239, 2.55% Pu240 and 0.1% Pu241. The overall layout of the reactor core and reflector is shown in the vertical section through the reactor vessel and the plan view. The core consists of a vertical array of 235 cylindrical graphite sleeves of outer diameter 7.37 cm into each of which a cylindrical graphite box may be loaded. Sunning longitudinally inside the box are six parallel grooves which act as locations for the edges of either the Pu/Al spikes or graphite dummies of the same external dimensions. Each groove accommodates two spikes end-to-end, with a small graphite spacer between to avoid welding together of the spike sheaths when heated. Lateral spacers of graphite or stainless steel fill the five spaces between the six spikes or dummies. The total length of the plutonium-loaded core region is 140 cm, the ends of the element forming graphite reflectors of length 53 cm. In Core 7 each fuel element contained 10 Pu-Al spikes. The fuel elements are arranged in a triangular lattice of pitch 7.62 cm to form the reactor core, of diameter 1.23 m. A radial graphite reflector approximately 1 metre thick surrounds the core and is separated from it by an annular lampblack thermal barrier, contained within graphite tiles, which reduces heat transfer from the core. The reactor can be heated by circulation of nitrogen through a 250 kW heater below the core. The nitrogen flows

  5. Spectrum measurements in the ZENITH plutonium core 7 using a neutron chopper

    International Nuclear Information System (INIS)

    Barclay, F.R.; Cameron, I.R.; Pitcher, H.H.W.; Symons, C.R.

    1964-05-01

    As part of the experimental programme on the first plutonium loading of ZENITH (Core 7) a series of measurements was carried out with the neutron chopper on a beam emerging from the core centre. The general experimental programme on the two ZENITH plutonium cores has been covered elsewhere. Core 7 had a carbon/Pu239 atomic ratio of 2666 and a steel/Pu239 ratio of 76.8, giving an absorption cross-section at 2200 m/sec. of 0.31 barns/carbon atom. The fuel was in the form of 'spikes' of 0.020 in. thick Pu/Al alloy sheathed in 0.020 in. aluminium, the isotopic composition of the plutonium being 97.4% Pu239, 2.55% Pu240 and 0.1% Pu241. The overall layout of the reactor core and reflector is shown in the vertical section through the reactor vessel and the plan view. The core consists of a vertical array of 235 cylindrical graphite sleeves of outer diameter 7.37 cm into each of which a cylindrical graphite box may be loaded. Sunning longitudinally inside the box are six parallel grooves which act as locations for the edges of either the Pu/Al spikes or graphite dummies of the same external dimensions. Each groove accommodates two spikes end-to-end, with a small graphite spacer between to avoid welding together of the spike sheaths when heated. Lateral spacers of graphite or stainless steel fill the five spaces between the six spikes or dummies. The total length of the plutonium-loaded core region is 140 cm, the ends of the element forming graphite reflectors of length 53 cm. In Core 7 each fuel element contained 10 Pu-Al spikes. The fuel elements are arranged in a triangular lattice of pitch 7.62 cm to form the reactor core, of diameter 1.23 m. A radial graphite reflector approximately 1 metre thick surrounds the core and is separated from it by an annular lampblack thermal barrier, contained within graphite tiles, which reduces heat transfer from the core. The reactor can be heated by circulation of nitrogen through a 250 kW heater below the core. The nitrogen flows

  6. ParaSol - A Novel Deployable Approach for Very Large Ultra-lightweight Solar Arrays, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — High power solar arrays with capabilities of >100kW are needed for projected NASA missions. Photovoltaic arrays using deployable membranes with thin cells have...

  7. Surface and Tethered-Balloon Observations of Actinic Flux: Effects of Arctic stratus, Surface Albedo and Solar Zenith Angle

    NARCIS (Netherlands)

    Roode, S.R. de; Duynkerke, P.G.; Boot, Wim; Hage, Jeroen C.H. van der

    2000-01-01

    As part of the FIRE III (First ISCCP Regional Experiment) Arctic Cloud Experiment actinic flux measurements were made above the Arctic Sea ice during May 1998. FIRE III was designed to address questions concerning clouds, radiation and chemistry in the Arctic sea ice region. The actinic flux,

  8. Simulating Large Area, High Intensity AM0 Illumination – Test Results from Bepicolombo and Solar Orbiter Qualification

    Directory of Open Access Journals (Sweden)

    Oberhüttinger C.

    2017-01-01

    Specifically, the following topics will be treated. Different methods like electrical performance, thermo-optical and external quantum efficiency measurements have been used to characterize the behaviour of the solar cells after illumination under these conditions. A special focus has been put on the electrical performance. A comparison to other solar cell qualification tests under solely UV radiation has been undertaken. The results have also been compared to a theoretical model. However, the paper will not cover only characterization results but will also give some insight in challenges experienced during the test execution itself. Deviating from other solar cell qualification tests, a representatively equipped photovoltaic assembly on carbon fibre reinforced cyanate has also been included. On these coupon segments, solar cell assemblies connected to shunt diodes and placed next to optical surface reflectors have been exposed to AM0 illumination to qualify the solar cells including their surroundings which therefore covers also contamination effects. Last but not least, first results from the Solar Orbiter qualification are presented. This test with additional 1000 hours and increased intensity has been completed recently.

  9. Roll-to-Roll printed large-area all-polymer solar cells with 5% efficiency based on a low crystallinity conjugated polymer blend

    Science.gov (United States)

    Gu, Xiaodan; Zhou, Yan; Gu, Kevin; Kurosawa, Tadanori; Yan, Hongping; Wang, Cheng; Toney, Micheal; Bao, Zhenan

    The challenge of continuous printing in high efficiency large-area organic solar cells is a key limiting factor for their widespread adoption. We present a materials design concept for achieving large-area, solution coated all-polymer bulk heterojunction (BHJ) solar cells with stable phase separation morphology between the donor and acceptor. The key concept lies in inhibiting strong crystallization of donor and acceptor polymers, thus forming intermixed, low crystallinity and mostly amorphous blends. Based on experiments using donors and acceptors with different degree of crystallinity, our results showed that microphase separated donor and acceptor domain sizes are inversely proportional to the crystallinity of the conjugated polymers. This methodology of using low crystallinity donors and acceptors has the added benefit of forming a consistent and robust morphology that is insensitive to different processing conditions, allowing one to easily scale up the printing process from a small scale solution shearing coater to a large-scale continuous roll-to-roll (R2R) printer. We were able to continuously roll-to-roll slot die print large area all-polymer solar cells with power conversion efficiencies of 5%, with combined cell area up to 10 cm2. This is among the highest efficiencies realized with R2R coated active layer organic materials on flexible substrate. DOE BRIDGE sunshot program. Office of Naval Research.

  10. Demonstrating of Cosmic Ray Characteristics by Estimating the Cherenkov Light Lateral Distribution Function for Yakutsk Array as a Function of the Zenith Angle

    OpenAIRE

    Abdulsttar, Marwah M.; Al-Rubaiee, A. A.; Ali, Abdul Halim Kh.

    2016-01-01

    Cherenkov light lateral distribution function (CLLDF) in Extensive Air Showers (EAS) for different primary particles (e-, n , p, F, K and Fe) was simulated using CORSIKA code for conditions and configurations of Yakutsk EAS array with the fixed primary energy 3 PeV around the knee region at different zenith angles. Basing on the results of CLLDF numerical simulation, sets of approximated functions are reconstructed for different primary particles as a function of the zenith angle. A compariso...

  11. Bi-functional TiO2 cemented Ag grid under layer for enhancing the photovoltaic performance of a large-area dye-sensitized solar cell

    International Nuclear Information System (INIS)

    Lan Zhang; Wu Jihuai; Lin Jianming; Huang, Miaoliang

    2012-01-01

    Graphical abstract: Enhanced photovoltaic performance of large-area DSSC with conductive grids in the photo and counter electrodes. Highlights: ► TiO 2 protected Ag grids is made for using as electrode in large-area DSSC. ► The electrode has high conductivity and low internal resistance. ► TiO 2 protected Ag grids electrode avoids iodine corrosion in electrolyte. ► The TiO 2 layer also play a blocking layer role. ► Above factors enhance the photovoltaic performance of large-area DSSC. - Abstract: A bi-functional TiO 2 cemented Ag grid under layer for enhanced the photovoltaic performance of a large-area dye-sensitized solar cell (DSSC) is prepared with a simple way. The conductive printing paste contains micro-sized Ag powders and nano-sized TiO 2 cementing agent. The conductive printing paste can be well cemented on the FTO glass and form high conductive grids with Ag powders sintered together by the nano-sized TiO 2 particles. The formed conductive grid is protected with a TiO 2 thin layer and TiO 2 sol treatment to avoid the iodine corrosion. The addition of the TiO 2 cemented conductive grid can decrease the internal resistance of the large-area dye-sensitized solar cell when it is prepared in the photo and counter electrodes. Furthermore, the protecting TiO 2 thin layer and the TiO 2 sol treatment can be done on the whole area of the large-area photo electrode to both play as the blocking under layer at the same time, which can also enhance the photovoltaic performance of the large-area dye-sensitized solar cell.

  12. Radio tomography and scintillation studies of ionospheric electron density modification caused by a powerful HF-wave and magnetic zenith effect at mid-latitudes

    International Nuclear Information System (INIS)

    Tereshchenko, E.D.; Khudukon, B.Z.; Gurevich, A.V.; Zybin, K.P.; Frolov, V.L.; Myasnikov, E.N.; Muravieva, N.V.; Carlson, H.C.

    2004-01-01

    Observations of the ionospheric electron density modified by a powerful wave of the Sura HF heating facility were carried out in Russia at middle latitudes in August 2002. Amplitude scintillations and variations of the phase of VHF signals from Russian orbiting satellites passing over the heated region along the chain of three satellite receivers have been recorded. The experimental data were converted to electron density maps using a stochastic inversion. Tomographic measurements conducted during a low magnetic activity revealed that HF powerful waves can produce significant electron density disturbances up to heights significantly exceeding altitudes of the F layer peak. Both large-scale plasma enhancements and small-scale density irregularities can be generated by the HF radiation. Wavy density structures were also observed within a sector which is much wider than the area covered by the main lobe of the heating antenna. Small-scale density irregularities are mostly field-aligned although large-scale structures can be detected within a much larger area. A distinctive peculiarity of electron density changes occurred during heating is producing a zone of low density inside the area illuminated by the antenna beam. The results indicate that satellite radio tomography and scintillation measurements are effective diagnostic techniques giving a valuable information to studies of effects induced by HF modification. The complete system of plasma density disturbances describing by the theory of 'the magnetic zenith effect' has been for the first time studied in this Letter. A good agreement between the theory and experimental data has been obtained

  13. Assimilation of zenith total delays in the AROME France convective scale model: a recent assessment

    Directory of Open Access Journals (Sweden)

    Jean-Francois Mahfouf

    2015-02-01

    Full Text Available The impact of assimilating GPS zenith total delays (ZTD in the convective scale model AROME is assessed over a 1-month period in summer 2013. The experimental set-up is similar to the current operational usage at Météo-France where the observing system has been expanded in July 2013 in a three-dimensional variational (3D-Var data assimilation scheme with a 3-hour cycling. Three experiments are performed. In a baseline experiment the GPS ZTD provided through the E-GVAP programme are withdrawn from the observing system (NOGPS. In a second experiment, GPS ZTD from E-GVAP are included in the observing system, representing the operational configuration at Météo-France (EGVAP. The last experiment is similar to EGVAP but new ZTD observations processed by the University of Luxembourg are also assimilated on top of all other observations (UL01. In the first stage, it has been verified through a systematic comparison with model counterparts that the quality of ZTD data processed by the University of Luxembourg is similar to the one provided by other analysis centres from the E-GVAP programme. After a number of quality controls, it has been possible to assimilate around 90 additional observations on top of around 600 stations from E-GVAP every 3 hours. Despite the small fraction of observations assimilated in AROME that ZTD represent (<2%, it is shown that they systematically improve the atmospheric humidity short-range forecasts by a comparison with other observing systems informative about water vapour (radiosoundings, satellite radiances, surface networks even though it is by small amounts. When examining objective precipitation scores over France, the improvement brought by the UL01 stations on top of E-GVAP is systematic for all daily precipitation thresholds. Examination of several case studies reveals the ability of the ZTD observations to modify the intensity and location of precipitating areas in accordance with previous studies. The addition

  14. SPECTRAL PROPERTIES OF LARGE GRADUAL SOLAR ENERGETIC PARTICLE EVENTS. II. SYSTEMATIC Q/M DEPENDENCE OF HEAVY ION SPECTRAL BREAKS

    Energy Technology Data Exchange (ETDEWEB)

    Desai, M. I.; Dayeh, M. A.; Ebert, R. W.; Schwadron, N. A. [Southwest Research Institute, 6220 Culebra Road, San Antonio, TX 78238 (United States); Mason, G. M. [Johns Hopkins University/Applied Physics Laboratory, Laurel, MD 20723 (United States); McComas, D. J. [Department of Astrophysical Sciences, Princeton University, NJ 08544 (United States); Li, G. [The Center for Space Plasma and Aeronomic Research (CSPAR), University of Alabama in Huntsville, Huntsville, AL 35756 (United States); Cohen, C. M. S.; Mewaldt, R. A. [California Institute of Technology, Pasadena, CA 91125 (United States); Smith, C. W., E-mail: mdesai@swri.edu [University of New Hampshire, 8 College Road, Durham NH 03824 (United States)

    2016-09-10

    We fit ∼0.1–500 MeV nucleon{sup −1} H–Fe spectra in 46 large solar energetic particle (SEP) events with the double power-law Band function to obtain a normalization constant, low- and high-energy parameters γ {sub a} and γ {sub b}, and break energy E {sub B}, and derive the low-energy spectral slope γ {sub 1}. We find that: (1) γ {sub a}, γ {sub 1}, and γ {sub b} are species-independent and the spectra steepen with increasing energy; (2) E {sub B} decreases systematically with decreasing Q/M scaling as (Q/M){sup α}; (3) α varies between ∼0.2–3 and is well correlated with the ∼0.16–0.23 MeV nucleon{sup −1} Fe/O; (4) in most events, α < 1.4, γ {sub b}– γ {sub a} > 3, and O E {sub B} increases with γ {sub b}– γ {sub a}; and (5) in many extreme events (associated with faster coronal mass ejections (CMEs) and GLEs), Fe/O and {sup 3}He/{sup 4}He ratios are enriched, α ≥ 1.4, γ {sub b}– γ {sub a} < 3, and E {sub B} decreases with γ {sub b}– γ {sub a}. The species-independence of γ {sub a}, γ {sub 1}, and γ {sub b} and the Q/M dependence of E {sub B} within an event and the α values suggest that double power-law SEP spectra occur due to diffusive acceleration by near-Sun CME shocks rather than scattering in interplanetary turbulence. Using γ {sub 1}, we infer that the average compression ratio for 33 near-Sun CME shocks is 2.49 ± 0.08. In most events, the Q/M dependence of E {sub B} is consistent with the equal diffusion coefficient condition and the variability in α is driven by differences in the near-shock wave intensity spectra, which are flatter than the Kolmogorov turbulence spectrum but weaker than the spectra for extreme events. In contrast, in extreme events, enhanced wave power enables faster CME shocks to accelerate impulsive suprathermal ions more efficiently than ambient coronal ions.

  15. A complete process for production of flexible large area polymer solar cells entirely using screen printing-First public demonstration

    DEFF Research Database (Denmark)

    Krebs, Frederik C; Jørgensen, Mikkel; Norrman, Kion

    2009-01-01

    , complete processing in air using commonly available screen printing, and finally, simple mechanical encapsulation using a flexible packaging material and electrical contacting post-production using crimped contacts. We detail the production of more than 2000 modules in one production run and show......A complete polymer solar cell module prepared in the ambient atmosphere under industrial conditions is presented. The versatility of the polymer solar cell technology is demonstrated through the use of abstract forms for the active area, a flexible substrate, processing entirely from solution...

  16. Vertically building Zn2SnO4 nanowire arrays on stainless steel mesh toward fabrication of large-area, flexible dye-sensitized solar cells.

    Science.gov (United States)

    Li, Zhengdao; Zhou, Yong; Bao, Chunxiong; Xue, Guogang; Zhang, Jiyuan; Liu, Jianguo; Yu, Tao; Zou, Zhigang

    2012-06-07

    Zn(2)SnO(4) nanowire arrays were for the first time grown onto a stainless steel mesh (SSM) in a binary ethylenediamine (En)/water solvent system using a solvothermal route. The morphology evolution following this reaction was carefully followed to understand the formation mechanism. The SSM-supported Zn(2)SnO(4) nanowire was utilized as a photoanode for fabrication of large-area (10 cm × 5 cm size as a typical sample), flexible dye-sensitized solar cells (DSSCs). The synthesized Zn(2)SnO(4) nanowires exhibit great bendability and flexibility, proving potential advantage over other metal oxide nanowires such as TiO(2), ZnO, and SnO(2) for application in flexible solar cells. Relative to the analogous Zn(2)SnO(4) nanoparticle-based flexible DSSCs, the nanowire geometry proves to enhance solar energy conversion efficiency through enhancement of electron transport. The bendable nature of the DSSCs without obvious degradation of efficiency and facile scale up gives the as-made flexible solar cell device potential for practical application.

  17. Optical and thermal performance of large-size parabolic-trough solar collectors from outdoor experiments: A test method and a case study

    International Nuclear Information System (INIS)

    Valenzuela, Loreto; López-Martín, Rafael; Zarza, Eduardo

    2014-01-01

    This article presents an outdoor test method to evaluate the optical and thermal performance of parabolic-trough collectors of large size (length ≥ 100 m), similar to those currently installed in solar thermal power plants. Optical performance in line-focus collectors is defined by three parameters, peak-optical efficiency and longitudinal and transversal incidence angle modifiers. In parabolic-troughs, the transversal incidence angle modifier is usually assumed equal to 1, and the incidence angle modifier is referred to the longitudinal incidence angle modifier, which is a factor less than or equal to 1 and must be quantified. These measurements are performed by operating the collector at low fluid temperatures for reducing heat losses. Thermal performance is measured during tests at various operating temperatures, which are defined within the working temperature range of the solar field, and for the condition of maximum optical response. Heat losses are measured from both the experiments performed to measure the overall efficiency and the experiments done by operating the collector to ensure that absorber pipes are not exposed to concentrated solar radiation. The set of parameters describing the performance of a parabolic-trough collector of large size has been measured following the test procedures proposed and explained in the article. - Highlights: • Outdoor test procedures of parabolic-trough solar collector (PTC) of large size working at high temperature are described. • Optical performance measured with cold fluid temperature and thermal performance measured in the complete temperature range. • Experimental data obtained in the testing of a PTC prototype are explained

  18. Multiple large solar lentigos on the upper back as clinical markers of past severe sunburn: a case-control study.

    Science.gov (United States)

    Derancourt, C; Bourdon-Lanoy, E; Grob, J-J; Guillaume, J-C; Bernard, P; Bastuji-Garin, S

    2007-01-01

    Multiple solar lentigos commonly seen on the upper back and shoulders of adults are classically considered as a sign of photodamage, although epidemiological studies are scarce. To assess whether these lesions are clinical markers of past severe sunburn. A case-control study in two outpatient dermatology clinics in French university hospitals. Past episodes of moderate and severe sunburn were compared between 145 adult patients with multiple solar lentigos on the upper back and 145 matched controls. In multivariate analysis adjusted for potential confounders, recalled episodes of sunburn during childhood, adolescence and adulthood were independently associated with the presence of multiple solar lentigos (adjusted odds ratios, 95% confidence intervals: 2.3 (1.1-5.2) and 28.1 (10.4-75.6) for moderate and severe sunburn, respectively). Multiple solar lentigos on the upper back and shoulders of adults are potential clinical markers of past severe sunburn which may thus be used to identify a population at higher risk of developing cutaneous malignant melanoma.

  19. A round robin study of flexible large-area roll-to-roll processed polymer solar cell modules

    DEFF Research Database (Denmark)

    Gevorgyan, Suren

    2010-01-01

    by transportation to a participating laboratory for performance measurement and return to the starting location (Risø DTU) for re-measurement of the performance. It was found possible to package polymer solar-cell modules using a flexible plastic barrier material in such a manner that degradation of the devices...

  20. Reliable solution processed planar perovskite hybrid solar cells with large-area uniformity by chloroform soaking and spin rinsing induced surface precipitation

    Directory of Open Access Journals (Sweden)

    Yann-Cherng Chern

    2015-08-01

    Full Text Available A solvent soaking and rinsing method, in which the solvent was allowed to soak all over the surface followed by a spinning for solvent draining, was found to produce perovskite layers with high uniformity on a centimeter scale and with much improved reliability. Besides the enhanced crystallinity and surface morphology due to the rinsing induced surface precipitation that constrains the grain growth underneath in the precursor films, large-area uniformity with film thickness determined exclusively by the rotational speed of rinsing spinning for solvent draining was observed. With chloroform as rinsing solvent, highly uniform and mirror-like perovskite layers of area as large as 8 cm × 8 cm were produced and highly uniform planar perovskite solar cells with power conversion efficiency of 10.6 ± 0.2% as well as much prolonged lifetime were obtained. The high uniformity and reliability observed with this solvent soaking and rinsing method were ascribed to the low viscosity of chloroform as well as its feasibility of mixing with the solvent used in the precursor solution. Moreover, since the surface precipitation forms before the solvent draining, this solvent soaking and rinsing method may be adapted to spinless process and be compatible with large-area and continuous production. With the large-area uniformity and reliability for the resultant perovskite layers, this chloroform soaking and rinsing approach may thus be promising for the mass production and commercialization of large-area perovskite solar cells.

  1. Retrieval of nitrogen dioxide stratospheric profiles from ground-based zenith-sky UV-visible observations: validation of the technique through correlative comparisons

    Directory of Open Access Journals (Sweden)

    F. Hendrick

    2004-01-01

    Full Text Available A retrieval algorithm based on the Optimal Estimation Method (OEM has been developed in order to provide vertical distributions of NO2 in the stratosphere from ground-based (GB zenith-sky UV-visible observations. It has been applied to observational data sets from the NDSC (Network for Detection of Stratospheric Change stations of Harestua (60° N, 10° E and Andøya (69° N, 16° E in Norway. The information content and retrieval errors have been analyzed following a formalism used for characterizing ozone profiles retrieved from solar infrared absorption spectra. In order to validate the technique, the retrieved NO2 vertical profiles and columns have been compared to correlative balloon and satellite observations. Such extensive validation of the profile and column retrievals was not reported in previously published work on the profiling from GB UV-visible measurements. A good agreement - generally better than 25% - has been found with the SAOZ (Système d'Analyse par Observations Zénithales and DOAS (Differential Optical Absorption Spectroscopy balloons. A similar agreement has been reached with correlative satellite data from the HALogen Occultation Experiment (HALOE and Polar Ozone and Aerosol Measurement (POAM III instruments above 25km of altitude. Below 25km, a systematic underestimation - by up to 40% in some cases - of both HALOE and POAM III profiles by our GB profile retrievals has been observed, pointing out more likely a limitation of both satellite instruments at these altitudes. We have concluded that our study strengthens our confidence in the reliability of the retrieval of vertical distribution information from GB UV-visible observations and offers new perspectives in the use of GB UV-visible network data for validation purposes.

  2. Optimizing sensitivity of Unmanned Aerial System optical sensors for low zenith angles and cloudy conditions

    DEFF Research Database (Denmark)

    Wang, Sheng; Dam-Hansen, Carsten; Zarco Tejada, Pablo J.

    . The multispectral camera (Tetra Mini-MCA6) has 6 channels in the visible and near Infrared. For the laboratory calibration experiment, different camera settings and typical irradiance levels from cloudy to clear sky were designed. The light-source is based on super-continuum generation to produce a continuous solar...

  3. Solar Energy Technician/Installer

    Science.gov (United States)

    Moore, Pam

    2007-01-01

    Solar power (also known as solar energy) is solar radiation emitted from the sun. Large panels that absorb the sun's energy as the sun beats down on them gather solar power. The energy in the rays can be used for heat (solar thermal energy) or converted to electricity (photovoltaic energy). Each solar energy project, from conception to…

  4. Flexible CIGS solar cells on large area polymer foils with in-line deposition methods and application of alternative back contacts - Final report

    Energy Technology Data Exchange (ETDEWEB)

    Tiwari, A. N.

    2009-08-15

    This illustrated report for the Swiss Federal Office of Energy (SFOE) summarises the work performed within this project and also reports on synergies with other projects that helped to make a significant contribution to the development of CIGS thin film solar cells on flexible substrates such as polymer foils. The project's aims were to learn more about up-scaling issues and to demonstrate the abilities required for the processing of layers on large area polyimide foils for flexible CIGS solar cells. Custom-built evaporators that were designed and constructed in-house are described. A CIGS system for in-line deposition was also modified for roll-to-roll deposition and alternative electrical back contacts to conventional ones were evaluated on flexible polyimide foils. The objectives of the project and the results obtained are looked at and commented on in detail.

  5. Determination of zenith hydrostatic delay and its impact on GNSS-derived integrated water vapor

    Directory of Open Access Journals (Sweden)

    X. Wang

    2017-08-01

    Full Text Available Surface pressure is a necessary meteorological variable for the accurate determination of integrated water vapor (IWV using Global Navigation Satellite System (GNSS. The lack of pressure observations is a big issue for the conversion of historical GNSS observations, which is a relatively new area of GNSS applications in climatology. Hence the use of the surface pressure derived from either a blind model (e.g., Global Pressure and Temperature 2 wet, GPT2w or a global atmospheric reanalysis (e.g., ERA-Interim becomes an important alternative solution. In this study, pressure derived from these two methods is compared against the pressure observed at 108 global GNSS stations at four epochs (00:00, 06:00, 12:00 and 18:00 UTC each day for the period 2000–2013. Results show that a good accuracy is achieved from the GPT2w-derived pressure in the latitude band between −30 and 30° and the average value of 6 h root-mean-square errors (RMSEs across all the stations in this region is 2.5 hPa. Correspondingly, an error of 5.8 mm and 0.9 kg m−2 in its resultant zenith hydrostatic delay (ZHD and IWV is expected. However, for the stations located in the mid-latitude bands between −30 and −60° and between 30 and 60°, the mean value of the RMSEs is 7.3 hPa, and for the stations located in the high-latitude bands from −60 to −90° and from 60 to 90°, the mean value of the RMSEs is 9.9 hPa. The mean of the RMSEs of the ERA-Interim-derived pressure across at the selected 100 stations is 0.9 hPa, which will lead to an equivalent error of 2.1 mm and 0.3 kg m−2 in the ZHD and IWV, respectively, determined from this ERA-Interim-derived pressure. Results also show that the monthly IWV determined using pressure from ERA-Interim has a good accuracy − with a relative error of better than 3 % on a global scale; thus, the monthly IWV resulting from ERA-Interim-derived pressure has the potential to be used for climate studies

  6. Studies on improvement of tomato productivity in a large-scale greenhouse: Prediction of tomato yield based on integrated solar radiation

    International Nuclear Information System (INIS)

    Hisaeda, K.; Nishina, H.

    2007-01-01

    As there are currently many large-scale production facilities that have contracts with the large retailing companies, accurate prediction of yield is necessary. The present study developed a method to predict tomato yield accurately using the data on the outside solar radiation. The present study was conducted in a Venlo-type greenhouse (29,568 square m) at Sera Farm Co., Ltd. in Sera-cho in Hiroshima prefecture. The cultivar used for this experiment was plum tomato. The sowing took place on July 18, the planting took place on August 30, and the harvesting started on October 9, 2002. The planting density was 2.5 plants msup(-2). As the results of the analysis of correlation between the weekly tomato yield and the integrated solar radiation for the period from October 7 to July 28 (43 weeks), the highest correlation (r = 0.518) between the weekly tomato yield and the solar radiation integrated from seven to one weeks before the harvesting was observed. Further investigation by the same correlation analysis was conducted for the 25 weeks period from December 8 to May 26, during which time the effect of growing stages and air temperature were considered to be relatively small. The results showed the highest correlation (r = 0.730) between the weekly tomato yield and the solar radiation integrated from eight to one weeks before the harvesting. The tomato yield occasionally needed to be adjusted at Sera Farm. Consequently, the correlation between the three-week moving average of tomato yield and the integrated solar radiation was calculated. The results showed the highest correlation was obtained for the period from eight to one weeks before the harvesting (r = 0.860). This study therefore showed that it was possible to predict the tomato yield (y: kg.msup(-2).weeksup(-1)) using the following equation on the solar radiation integrated from eight to one weeks before the harvesting(x: MJ.msup(-2)): y = 7.50 x 10 sup(-6)x + 0.148 (rsup(2) = 0.740)

  7. High-Rate Fabrication of a-Si-Based Thin-Film Solar Cells Using Large-Area VHF PECVD Processes

    Energy Technology Data Exchange (ETDEWEB)

    Deng, Xunming [University of Toledo; Fan, Qi Hua

    2011-12-31

    The University of Toledo (UT), working in concert with it’s a-Si-based PV industry partner Xunlight Corporation (Xunlight), has conducted a comprehensive study to develop a large-area (3ft x 3ft) VHF PECVD system for high rate uniform fabrication of silicon absorber layers, and the large-area VHF PECVD processes to achieve high performance a-Si/a-SiGe or a-Si/nc-Si tandem junction solar cells during the period of July 1, 2008 to Dec. 31, 2011, under DOE Award No. DE-FG36-08GO18073. The project had two primary goals: (i) to develop and improve a large area (3 ft × 3 ft) VHF PECVD system for high rate fabrication of > = 8 Å/s a-Si and >= 20 Å/s nc-Si or 4 Å/s a-SiGe absorber layers with high uniformity in film thicknesses and in material structures. (ii) to develop and optimize the large-area VHF PECVD processes to achieve high-performance a-Si/nc-Si or a-Si/a-SiGe tandem-junction solar cells with >= 10% stable efficiency. Our work has met the goals and is summarized in “Accomplishments versus goals and objectives”.

  8. Solar Science with the Atacama Large Millimeter/Submillimeter Array-A New View of Our Sun

    Czech Academy of Sciences Publication Activity Database

    Wedemeyer, S.; Bastian, T.S.; Brajša, R.; Hudson, H. S.; Fleishman, G.; Loukitcheva, M.; Fleck, B.; Kontar, E. P.; de Pontieu, B.; Yagoubov, P.; Tiwari, S.; Soler, R.; Black, J.H.; Antolin, P.; Scullion, E.; Gunár, Stanislav; Labrosse, N.; Ludwig, H.-G.; Benz, A. O.; White, S.M.; Hauschildt, P.; Doyle, J.G.; Nakariakov, V. M.; Ayres, T.; Heinzel, Petr; Karlický, Marian; Van Doorsselaere, T.; Gary, D.; Alissandrakis, C. E.; Nindos, A.; Solanki, S.K.; Rouppe van der Voort, L.; Shimojo, M.; Kato, Y.; Zaqarashvili, T.; Perez, E.; Selhorst, C.L.; Bárta, Miroslav

    2016-01-01

    Roč. 200, 1-4 (2016), s. 1-73 ISSN 0038-6308 R&D Projects: GA ČR GA13-24782S EU Projects: European Commission(XE) 312495 - SOLAR NET Grant - others:EC(XE) 606862 Program:FP7 Institutional support: RVO:67985815 Keywords : Sun * photosphere * chromosphere Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics Impact factor: 7.497, year: 2016

  9. Solar wind modulation of the Martian ionosphere observed by Mars Global Surveyor

    Directory of Open Access Journals (Sweden)

    J.-S. Wang

    2004-06-01

    Full Text Available Electron density profiles in the Martian ionosphere observed by the radio occultation experiment on board Mars Global Surveyor have been analyzed to determine if the densities are influenced by the solar wind. Evidence is presented that the altitude of the maximum ionospheric electron density shows a positive correlation to the energetic proton flux in the solar wind. The solar wind modulation of the Martian ionosphere can be attributed to heating of the neutral atmosphere by the solar wind energetic proton precipitation. The modulation is observed to be most prominent at high solar zenith angles. It is argued that this is consistent with the proposed modulation mechanism.

  10. Effect of Codoping Cl Anion and 5-AVA Cation on Performance of Large-Area Perovskite Solar Cells with Double-Mesoporous Layers

    Directory of Open Access Journals (Sweden)

    Yaxian Pei

    2016-01-01

    Full Text Available For the perovskite solar cells (PSCs, the performance of the PSCs has become the focus of the research by improving the quality of the perovskite absorption layer. So far, the performance of the large-area PSCs is lower than that of small-area PSCs. In the paper, the experiments were designed to improve the photovoltaic performance of the large-area PSCs by improved processing technique. Here we investigated the optoelectronic properties of the prototypical CH3NH3PbI3 (MAPbI3 further modulated by introducing other extrinsic ions (specifically codoped Cl− and 5-AVA+. Moreover, we used inorganic electron extraction layer to achieve very rapid photogenerated carrier extraction eliminating local structural defects over large areas. Ultimately, we fabricated a best-performing perovskite solar cell based on codoping Cl anion and 5-AVA cation which uses a double layer of mesoporous TiO2 and ZrO2 as a scaffold infiltrated with perovskite and does not require a hole-conducting layer. The experiment results indicated that an average efficiency of double-mesoporous layer-based devices with codoping Cl anion and 5-AVA cation was obtained with exceeding 50% enhancement, compared to that of pure single-mesoporous layer-based device.

  11. Dedicated Tool for Irradiation and Electrical Measurement of Large Surface Samples on the Beamline of a 2.5 Mev Pelletron Electron Accelerator: Application to Solar Cells

    OpenAIRE

    Lefèvre Jérémie; Le Houedec Patrice; Losco Jérôme; Cavani Olivier; Boizot Bruno

    2017-01-01

    We designed a tool allowing irradiation of large samples over a surface of A5 size dimension by means of a 2.5 MeV Pelletron electron accelerator. in situ electrical measurements (I-V, conductivity, etc.) can also be performed, in the dark or under illumination, to study radiation effects in materials. Irradiations and electrical measurements are achievable over a temperature range from 100 K to 300 K. The setup was initially developed to test real-size triple junction solar cells at low t...

  12. MEASUREMENT OF LARGE-SCALE SOLAR POWER PLANT BY USING IMAGES ACQUIRED BY NON-METRIC DIGITAL CAMERA ON BOARD UAV

    Directory of Open Access Journals (Sweden)

    R. Matsuoka

    2012-07-01

    Full Text Available This paper reports an experiment conducted in order to investigate the feasibility of the deformation measurement of a large-scale solar power plant on reclaimed land by using images acquired by a non-metric digital camera on board a micro unmanned aerial vehicle (UAV. It is required that a root mean squares of errors (RMSE in height measurement should be less than 26 mm that is 1/3 of the critical limit of deformation of 78 mm off the plane of a solar panel. Images utilized in the experiment have been obtained by an Olympus PEN E-P2 digital camera on board a Microdrones md4-1000 quadrocopter. The planned forward and side overlap ratios of vertical image acquisition have been 60 % and 60 % respectively. The planned flying height of the UAV has been 20 m above the ground level and the ground resolution of an image is approximately 5.0 mm by 5.0 mm. 8 control points around the experiment area are utilized for orientation. Measurement results are evaluated by the space coordinates of 220 check points which are corner points of 55 solar panels selected from 1768 solar panels in the experiment area. Two teams engage in the experiment. One carries out orientation and measurement by using 171 images following the procedure of conventional aerial photogrammetry, and the other executes those by using 126 images in the manner of close range photogrammetry. The former fails to satisfy the required accuracy, while the RMSE in height measurement by the latter is 8.7 mm that satisfies the required accuracy. From the experiment results, we conclude that the deformation measurement of a large-scale solar power plant on reclaimed land by using images acquired by a nonmetric digital camera on board a micro UAV would be feasible if points utilized in orientation and measurement have a sufficient number of bundles in good geometry and self-calibration in orientation is carried out.

  13. Daylight levels during the solar eclipse of 11 August 1999

    Science.gov (United States)

    Darula, S.; Kambezidis, H. D.; Kittler, R.

    Solar eclipses are unique phenomena not only for astronomical and space observations but also for terrestrial; they create unique conditions of sunbeam blockage which cause not only the reduction of direct sunlight but also the dimming of skylight from the whole sky vault. Very favorable conditions were met during the recent August 1999 solar eclipse in Athens, Greece and Bratislava, Slovakia. General class daylight stations operate within the International Daylight Measurements Program in the two cities. One-minute data of global/diffuse illuminance and zenith luminance from those stations have been used to provide information about their levels and the daylight reduction rate during the eclipse. An approximate formula for the estimation of sunlight and skylight illuminance levels as well as zenith luminance using relative luminance sky patterns is also presented in this work. To achieve this, recently developed sky standards together with their parameterizations are utilized.

  14. An overview of the solar, anomalous, and magnetospheric particle explorer (SAMPEX) mission

    International Nuclear Information System (INIS)

    Baker, D.N.; Mason, G.M.; Figueroa, O.; Colon, G.; Watzin, J.G.; Aleman, R.M.

    1993-01-01

    The scientific objective of the NASA Small-class Explorer Mission SAMPEX are summarized. A brief history of the Small Explorer program is provided along with a description of the SAMPEX project development and structure. The spacecraft and scientific instrument configuration is presented. The orbit of SAMPEX has an altitude of 520 by 670 km and an 82 degree inclination. Maximum possible power is provided by articulated solar arrays that point continuously toward the sun. Highly sensitive science instruments point generally toward the local zenith, especially over the terrestrial poles, in order to measure optimally the galactic and solar cosmic ray flux. Energetic magnetospheric particle precipitation is monitored at lower geomagnetic latitudes. The spacecraft uses several innovative approaches including an optical fiber bus, powerful onboard computers, and large solid state memories (instead of tape recorders). Spacecraft communication and data acquisition are discussed and the space- and ground-segment data flows are summarized. A mission lifetime of 3 years is sought with the goal of extending data acquisition over an even longer portion of the 11-year solar activity cycle

  15. Ultrasonic Spray-Coating of Large-Scale TiO2 Compact Layer for Efficient Flexible Perovskite Solar Cells

    Directory of Open Access Journals (Sweden)

    Peng Zhou

    2017-02-01

    Full Text Available Flexible electronics have attracted great interest in applications for the wearable devices. Flexible solar cells can be integrated into the flexible electronics as the power source for the wearable devices. In this work, an ultrasonic spray-coating method was employed to deposit TiO2 nanoparticles on polymer substrates for the fabrication of flexible perovskite solar cells (PSCs. Pre-synthesized TiO2 nanoparticles were first dispersed in ethanol to prepare the precursor solutions with different concentrations (0.5 mg/mL, 1.0 mg/mL, 2.0 mg/mL and then sprayed onto the conductive substrates to produce compact TiO2 films with different thicknesses (from 30 nm to 150 nm. The effect of the different drying processes on the quality of the compact TiO2 film was studied. In order to further improve the film quality, titanium diisopropoxide bis(acetylacetonate (TAA was added into the TiO2-ethanol solution at a mole ratio of 1.0 mol % with respect to the TiO2 content. The final prepared PSC devices showed a power conversion efficiency (PCE of 14.32% based on the indium doped tin oxide coated glass (ITO-glass substrate and 10.87% on the indium doped tin oxide coated polyethylene naphthalate (ITO-PEN flexible substrate.

  16. Continuous blade coating for multi-layer large-area organic light-emitting diode and solar cell

    Science.gov (United States)

    Chen, Chun-Yu; Chang, Hao-Wen; Chang, Yu-Fan; Chang, Bo-Jie; Lin, Yuan-Sheng; Jian, Pei-Siou; Yeh, Han-Cheng; Chien, Hung-Ta; Chen, En-Chen; Chao, Yu-Chiang; Meng, Hsin-Fei; Zan, Hsiao-Wen; Lin, Hao-Wu; Horng, Sheng-Fu; Cheng, Yen-Ju; Yen, Feng-Wen; Lin, I.-Feng; Yang, Hsiu-Yuan; Huang, Kuo-Jui; Tseng, Mei-Rurng

    2011-11-01

    A continuous roll-to-roll compatible blade-coating method for multi-layers of general organic semiconductors is developed. Dissolution of the underlying film during coating is prevented by simultaneously applying heating from the bottom and gentle hot wind from the top. The solvent is immediately expelled and reflow inhibited. This method succeeds for polymers and small molecules. Uniformity is within 10% for 5 cm by 5 cm area with a mean value of tens of nanometers for both organic light-emitting diode (OLED) and solar cell structure with little material waste. For phosphorescent OLED 25 cd/A is achieved for green, 15 cd/A for orange, and 8 cd/A for blue. For fluorescent OLED 4.3 cd/A is achieved for blue, 9 cd/A for orange, and 6.9 cd/A for white. For OLED with 2 cm by 3 cm active area, the luminance variation is within 10%. Power conversion efficiency of 4.1% is achieved for polymer solar cell, similar to spin coating using the same materials. Very-low-cost and high-throughput fabrication of efficient organic devices is realized by the continuous blade-only method.

  17. Solar neutrino problem accounting for self-consistent magnetohydrodynamics solution for solar magnetic fields

    International Nuclear Information System (INIS)

    Miranda, O.G.; Pena-Garay, C.; Valle, J.W.F.; Rashba, T.I.; Semikoz, V.B.

    2001-01-01

    The analysis of the resonant spin-flavour (RSF) solutions to the solar neutrino problem in the framework of the simplest analytical solutions to the solar magnetohydrodynamics (MHD) equations is presented. We performed the global fit of the recent solar neutrino data, including event rates as well as zenith angle distributions and recoil electron spectra induced by solar neutrino interactions in Superkamiokande. We compare quantitatively our simplest MHD-RSF fit with vacuum oscillation (VAC) and MSW-type (SMA, LMA and LOW) solutions to the solar neutrino problem using a common well-calibrated theoretical calculation and fit procedure and find MHD-RSF fit to be somewhat better than those obtained for the favored neutrino oscillation solutions. We made the predictions for future experiments (e.g., SNO) to disentangle the MHD-RSF scenario from other scenarios

  18. Rational design of tetraphenylethylene-based luminescent down-shifting molecules: photophysical studies and photovoltaic applications in a CdTe solar cell from small to large units.

    Science.gov (United States)

    Li, Yilin; Li, Zhipeng; Ablekim, Tursunjan; Ren, Tianhui; Dong, Wen-Ji

    2014-12-21

    A rational design strategy of novel fluorophores for luminescent down-shifting (LDS) application was proposed and tested in this paper. Three new fluorophores (1a-c) with specific intramolecular charge transfer (ICT) and aggregation-induced emission (AIE) characteristics were synthesized as LDS molecules for increasing the output short circuit current density (Jsc) of a CdTe solar cell. Photophysical studies of their solution and solid states, and photovoltaic measurements of their PMMA solid films applied on a CdTe solar cell suggested that the specific spectroscopic properties and Jsc enhancement effects of these molecules were highly related to their chemical structures. The Jsc enhancement effects of these fluorophores were measured on both a CdTe small cell and a large panel. An increase in the output Jsc by as high as 5.69% for a small cell and 8.88% for a large panel was observed. Compared to a traditional LDS molecule, Y083, these fluorophores exhibited more superior capabilities of LDS.

  19. Search for neutrino generated air shower candidates with energy ≥ 1019 eV and Zenith angle θ

    Science.gov (United States)

    Knurenko, Stanislav; Petrov, Igor; Sabourov, Artem

    2017-06-01

    The description of the methodology and results of searching for air showers generated by neutral particles such as high energy gamma quanta and astroneutrinos are presented. For this purpose, we conducted a comprehensive analysis of the data: the electron, the muon and the EAS Cerenkov light, and their response time in scintillation and Cherenkov detectors. Air showers with energy more than 5·1018 eV and zenith angle θ ≥ 55∘ are selected and analyzed. Search results indicate a lack of air shower events formed by gamma-rays or high-energy neutrinos, but it does not mean that such air showers do not exist in nature; for example, experiments that recorded showers having a marked low muon content, i.e., "Muonless", are likely to be candidates for showers produced by neutral primary particles.

  20. Contribution of corner reflections from oriented ice crystals to backscattering and depolarization characteristics for off-zenith lidar profiling

    Science.gov (United States)

    Borovoi, Anatoli G.; Konoshonkin, Alexander V.; Kustova, Natalia V.; Veselovskii, Igor A.

    2018-06-01

    Backscattering Mueller matrix and the depolarization and color ratios for quasi-horizontally oriented hexagonal ice plates have been calculated within the framework of the physical optics approximation. In the case of a tilted lidar, the dependence of the color and depolarization ratios on polarization of the incident light has been analyzed. It is shown that the corner reflection effect inherent to the pristine hexagonal ice crystals results in sharp peaks of both the backscattering cross section and depolarization ratio at the lidar tilts of about 30° off zenith. The experimental results obtained recently by Veselovskii et al. [13] at the lidar tilt of 43° have been interpreted as a partial manifestation of the corner reflection effect. The retrieval of the vertical profile of the ice crystal fraction consisting of quasi-horizontally oriented hexagonal plates has been demonstrated.

  1. Concentrated Solar Power as part of the European energy supply. The realization of large-scale solar power plants. Options, constraints and recommendations; Concentrated Solar Power als onderdeel van de Europese energievoorziening. De realisatie van grootschalige zonnecentrales. Mogelijkheden, obstakels en advies

    Energy Technology Data Exchange (ETDEWEB)

    Bouwmans, I.; Carton, L.J.; Dijkema, G.P.J.; Stikkelman, R.M.; De Vries, L.J. [Energy and Industry Group, Faculty of Technology, Policy and Management, Delft University of Technology, Delft (Netherlands)

    2006-07-01

    Next to solar cells and solar collectors for decentralized power generation Concentrated Solar Power (CSP) technology is available and proven for large-scale application of solar energy. However, after 20 years of demonstration projects and semi-commercial installations, CSP is still not widely used. In this quick-scan an overview is given of strong and weak points of CSP, as well as its' options and constraints with regard to a sustainable energy supply, focusing on technical, economical and administrative constraints and chances in Europe and European Union member states. [Dutch] Naast zonnecellen en zonnecollectoren voor decentrale opwekking is er een technologie die geschikt is voor grootschalige ontsluiting van de zon: Concentrated Solar Power, kortweg CSP. Bewezen in een aantal demonstratie- en pre-commerciele installaties blijft toepassing van deze technologie ook na 20 jaar beperkt. Daarom staat in deze notitie, die het resultaat is van een quickscan, de volgende vraag centraal: Wat zijn de sterktes, zwaktes, mogelijkheden en barrieres van CSP-technologie als onderdeel van een duurzame energievoorziening en welke technisch-economische en bestuurlijke barrieres en kansen zijn er voor Europa en de lidstaten van de EU?.

  2. Large-Area, Multi-Junction, Epitaxial Lift-Off Solar Cells with Backside Contacts, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — In this Phase II program we propose to develop a manufacturable production process to introduce backside contacts to MicroLink Devices? large-area, multi-junction...

  3. Large-Area, Multi-Junction, Epitaxial Lift-Off Solar Cells with Backside Contacts, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — In this Phase I program we propose to develop an innovative fabrication process to introduce backside contacts to MicroLink Devices' large-area, multi-junction...

  4. Solar Pump

    Science.gov (United States)

    Pique, Charles

    1987-01-01

    Proposed pump moves liquid by action of bubbles formed by heat of sun. Tube of liquid having boiling point of 100 to 200 degrees F placed at focal axis of cylindrical reflector. Concentrated sunlight boils liquid at focus, and bubbles of vapor rise in tube, carrying liquid along with them. Pressure difference in hot tube sufficient to produce flow in large loop. Used with conventional flat solar heating panel in completely solar-powered heat-storage system.

  5. Prediction of SYM-H index during large storms by NARX neural network from IMF and solar wind data

    Directory of Open Access Journals (Sweden)

    L. Cai

    2010-02-01

    Full Text Available Similar to the Dst index, the SYM-H index may also serve as an indicator of magnetic storm intensity, but having distinct advantage of higher time-resolution. In this study the NARX neural network has been used for the first time to predict SYM-H index from solar wind (SW and IMF parameters. In total 73 time intervals of great storm events with IMF/SW data available from ACE satellite during 1998 to 2006 are used to establish the ANN model. Out of them, 67 are used to train the network and the other 6 samples for test. Additionally, the NARX prediction model is also validated using IMF/SW data from WIND satellite for 7 great storms during 1995–1997 and 2005, as well as for the July 2000 Bastille day storm and November 2001 superstorm using Geotail and OMNI data at 1 AU, respectively. Five interplanetary parameters of IMF Bz, By and total B components along with proton density and velocity of solar wind are used as the original external inputs of the neural network to predict the SYM-H index about one hour ahead. For the 6 test storms registered by ACE including two super-storms of min. SYM-H<−200 nT, the correlation coefficient between observed and NARX network predicted SYM-H is 0.95 as a whole, even as high as 0.95 and 0.98 with average relative variance of 13.2% and 7.4%, respectively, for the two super-storms. The prediction for the 7 storms with WIND data is also satisfactory, showing averaged correlation coefficient about 0.91 and RMSE of 14.2 nT. The newly developed NARX model shows much better capability than Elman network for SYM-H prediction, which can partly be attributed to a key feedback to the input layer from the output neuron with a suitable length (about 120 min. This feedback means that nearly real information of the ring current status is effectively directed to take part in the prediction of SYM-H index by ANN. The proper history length of the output-feedback may mainly reflect

  6. Prediction of SYM-H index during large storms by NARX neural network from IMF and solar wind data

    Directory of Open Access Journals (Sweden)

    L. Cai

    2010-02-01

    Full Text Available Similar to the Dst index, the SYM-H index may also serve as an indicator of magnetic storm intensity, but having distinct advantage of higher time-resolution. In this study the NARX neural network has been used for the first time to predict SYM-H index from solar wind (SW and IMF parameters. In total 73 time intervals of great storm events with IMF/SW data available from ACE satellite during 1998 to 2006 are used to establish the ANN model. Out of them, 67 are used to train the network and the other 6 samples for test. Additionally, the NARX prediction model is also validated using IMF/SW data from WIND satellite for 7 great storms during 1995–1997 and 2005, as well as for the July 2000 Bastille day storm and November 2001 superstorm using Geotail and OMNI data at 1 AU, respectively. Five interplanetary parameters of IMF Bz, By and total B components along with proton density and velocity of solar wind are used as the original external inputs of the neural network to predict the SYM-H index about one hour ahead. For the 6 test storms registered by ACE including two super-storms of min. SYM-H<−200 nT, the correlation coefficient between observed and NARX network predicted SYM-H is 0.95 as a whole, even as high as 0.95 and 0.98 with average relative variance of 13.2% and 7.4%, respectively, for the two super-storms. The prediction for the 7 storms with WIND data is also satisfactory, showing averaged correlation coefficient about 0.91 and RMSE of 14.2 nT. The newly developed NARX model shows much better capability than Elman network for SYM-H prediction, which can partly be attributed to a key feedback to the input layer from the output neuron with a suitable length (about 120 min. This feedback means that nearly real information of the ring current status is effectively directed to take part in the prediction of SYM-H index by ANN. The proper history length of the output-feedback may mainly reflect on average the characteristic time of ring

  7. Room-Temperature and Solution-Processable Cu-Doped Nickel Oxide Nanoparticles for Efficient Hole-Transport Layers of Flexible Large-Area Perovskite Solar Cells.

    Science.gov (United States)

    He, Qiqi; Yao, Kai; Wang, Xiaofeng; Xia, Xuefeng; Leng, Shifeng; Li, Fan

    2017-12-06

    Flexible perovskite solar cells (PSCs) using plastic substrates have become one of the most attractive points in the field of thin-film solar cells. Low-temperature and solution-processable nanoparticles (NPs) enable the fabrication of semiconductor thin films in a simple and low-cost approach to function as charge-selective layers in flexible PSCs. Here, we synthesized phase-pure p-type Cu-doped NiO x NPs with good electrical properties, which can be processed to smooth, pinhole-free, and efficient hole transport layers (HTLs) with large-area uniformity over a wide range of film thickness using a room-temperature solution-processing technique. Such a high-quality inorganic HTL allows for the fabrication of flexible PSCs with an active area >1 cm 2 , which have a power conversion efficiency over 15.01% without hysteresis. Moreover, the Cu/NiO x NP-based flexible devices also demonstrate excellent air stability and mechanical stability compared to their counterpart fabricated on the pristine NiO x films. This work will contribute to the evolution of upscaling flexible PSCs with a simple fabrication process and high device performances.

  8. Performance-Oriented Design of Large Passive Solar Roofs : A method for the integration of parametric modelling and genetic algorithms

    NARCIS (Netherlands)

    Turrin, M.; Von Buelow, P.; Stouffs, R.M.F.; Kilian, A.

    2010-01-01

    The paper addresses the design of large roof structures for semi outdoor spaces through an investigation of a type of performance-oriented design, which aims at integrating performance evaluations in the early stages of the design process. Particularly, aiming at improving daylight and thermal

  9. Large area multicrystalline silicon solar cells with high efficiency. Final report; Grossflaechige multikristalline Silizium-Solarzellen mit hohen Wirkungsraden. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Ebest, G.; Erler, K.; Mrwa, A.; Ball, M.

    2001-09-01

    Solar cells were produced of wafers of die-cast and strip-drawn multicrystalline silicon and characterized. Production methods like SOD (spin-on doping), RTP (rapid thermal processing), PECVD (plasma enhanced chemical vapor deposition), RIE (reactive ion etching) and screen printing were investigated. The results are summarized as follows: 1. Layer resistance can be adjusted by variation of the RTP temperature cycle and by selecting appropriate doping materials (P507 by Filmtronics); 2. The low resistance required for screen printing metallization are obtained only with a different doping material (P8545SF-Filmtronics); 3. Metallized aluminium and copper require a 30 nm TiN layer as diffusion barrier; 4. Reflectivity will be reduced most effectively by RIE with chlorine gas on monocrystalline and multicrystalline silicon wafers. [German] Im Rahmen des Projektes wurden auf Wafern aus blockgegossenem und bandgezogenem multikristallinen Silizium Solarzellen hergestellt und charakterisiert. Fuer die Herstellung wurden Verfahren wie SOD (spin-on doping), RTP (rapid thermal processing), PECVD (plasma enhanced chemical vapor deposition), RIE (reactive ion etching) und Siebdruck untersucht. Die Ergebnisse lassen sich wie folgt zusammenfassen: 1. eine Einstellung des Schichtwiderstandes wird durch Variation des RTP-Temperaturzyklus sowie Auswahl verschiedener Dotierstoffe (P507 von Filmtronics) erreicht; 2. die fuer die Siebdruckmetallisierung erforderlichen geringen Schichtwiderstaende werden nur durch die Wahl eines anderen Dotierstoffes (P8545SF-Filmtronics) erreicht; 3. Aluminium- und Kupfermetallisierungen benoetigen eine 30 nm dicke TiN-Schicht als Diffusionsbarriere; und 4. die wirksamste Verminderung des Reflexionsgrades ist mittels RIE-Verfahren unter Verwendung von Chlorgas auf ein- und multikristalline Siliziumwafer erreichbar.

  10. News from heat-pump research - Large-scale heat pumps, components, heat pumps and solar heating; News aus der Waermepumpen-Forschung - Gross-Waermepumpen, Komponenten, Waermepumpe und Solar

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2010-06-15

    These proceedings summarise the presentations made at the 16{sup th} annual meeting held by the Swiss Federal Office of Energy's Heat Pump Research Program in Burgdorf, Switzerland. The proceedings include contributions on large-scale heat pumps, components and the activities of the heat pump promotion society. A summary of targets and trends in energy research in general is presented and an overview of the heat pump market in 2009 and future perspectives is given. International work within the framework of the International Energy Agency's heat pump group is reviewed, including solar - heat pump combinations. Field-monitoring and the analysis of large-scale heat pumps are discussed and the importance of the use of correct concepts in such installations is stressed. Large-scale heat pumps with carbon dioxide as working fluid are looked at, as are output-regulated air/water heat pumps. Efficient system solutions with heat pumps used both to heat and to cool are discussed. Deep geothermal probes and the potential offered by geothermal probes using carbon dioxide as a working fluid are discussed. The proceedings are rounded off with a list of useful addresses.

  11. Software development and its description for Geoid determination based on Spherical-Cap-Harmonics Modelling using digital-zenith camera and gravimetric measurements hybrid data

    Science.gov (United States)

    Morozova, K.; Jaeger, R.; Balodis, J.; Kaminskis, J.

    2017-10-01

    Over several years the Institute of Geodesy and Geoinformatics (GGI) was engaged in the design and development of a digital zenith camera. At the moment the camera developments are finished and tests by field measurements are done. In order to check these data and to use them for geoid model determination DFHRS (Digital Finite element Height reference surface (HRS)) v4.3. software is used. It is based on parametric modelling of the HRS as a continous polynomial surface. The HRS, providing the local Geoid height N, is a necessary geodetic infrastructure for a GNSS-based determination of physcial heights H from ellipsoidal GNSS heights h, by H=h-N. The research and this publication is dealing with the inclusion of the data of observed vertical deflections from digital zenith camera into the mathematical model of the DFHRS approach and software v4.3. A first target was to test out and validate the mathematical model and software, using additionally real data of the above mentioned zenith camera observations of deflections of the vertical. A second concern of the research was to analyze the results and the improvement of the Latvian quasi-geoid computation compared to the previous version HRS computed without zenith camera based deflections of the vertical. The further development of the mathematical model and software concerns the use of spherical-cap-harmonics as the designed carrier function for the DFHRS v.5. It enables - in the sense of the strict integrated geodesy approach, holding also for geodetic network adjustment - both a full gravity field and a geoid and quasi-geoid determination. In addition, it allows the inclusion of gravimetric measurements, together with deflections of the vertical from digital-zenith cameras, and all other types of observations. The theoretical description of the updated version of DFHRS software and methods are discussed in this publication.

  12. Multi-instrument observations of the solar eclipse on 20 March 2015 and its effects on the ionosphere over Belgium and Europe

    Science.gov (United States)

    Stankov, Stanimir M.; Bergeot, Nicolas; Berghmans, David; Bolsée, David; Bruyninx, Carine; Chevalier, Jean-Marie; Clette, Frédéric; De Backer, Hugo; De Keyser, Johan; D'Huys, Elke; Dominique, Marie; Lemaire, Joseph F.; Magdalenić, Jasmina; Marqué, Christophe; Pereira, Nuno; Pierrard, Viviane; Sapundjiev, Danislav; Seaton, Daniel B.; Stegen, Koen; Van der Linden, Ronald; Verhulst, Tobias G. W.; West, Matthew J.

    2017-08-01

    A total solar eclipse occurred on 20 March 2015, with a totality path passing mostly above the North Atlantic Ocean, which resulted in a partial solar eclipse over Belgium and large parts of Europe. In anticipation of this event, a dedicated observational campaign was set up at the Belgian Solar-Terrestrial Centre of Excellence (STCE). The objective was to perform high-quality observations of the eclipse and the associated effects on the geospace environment by utilising the advanced space- and ground-based instrumentation available to the STCE in order to further our understanding of these effects, particularly on the ionosphere. The study highlights the crucial importance of taking into account the eclipse geometry when analysing the ionospheric behaviour during eclipses and interpreting the eclipse effects. A detailed review of the eclipse geometry proves that considering the actual obscuration level and solar zenith angle at ionospheric heights is much more important for the analysis than at the commonly referenced Earth's surface or at the plasmaspheric heights. The eclipse occurred during the recovery phase of a strong geomagnetic storm which certainly had an impact on (some of) the ionospheric characteristics and perhaps caused the omission of some "low-profile" effects. However, the analysis of the ionosonde measurements, carried out at unprecedented high rates during the eclipse, suggests the occurrence of travelling ionospheric disturbances (TIDs). Also, the high temporal and spatial resolution measurements proved very important in revealing and estimating some finer details of the delay in the ionospheric reaction and the ionospheric disturbances.

  13. Nonlinear Force-free Field Extrapolation of a Coronal Magnetic Flux Rope Supporting a Large-scale Solar Filament from a Photospheric Vector Magnetogram

    Science.gov (United States)

    Jiang, Chaowei; Wu, S. T.; Feng, Xueshang; Hu, Qiang

    2014-05-01

    Solar filaments are commonly thought to be supported in magnetic dips, in particular, in those of magnetic flux ropes (FRs). In this Letter, based on the observed photospheric vector magnetogram, we implement a nonlinear force-free field (NLFFF) extrapolation of a coronal magnetic FR that supports a large-scale intermediate filament between an active region and a weak polarity region. This result is a first, in the sense that current NLFFF extrapolations including the presence of FRs are limited to relatively small-scale filaments that are close to sunspots and along main polarity inversion lines (PILs) with strong transverse field and magnetic shear, and the existence of an FR is usually predictable. In contrast, the present filament lies along the weak-field region (photospheric field strength barbs very well, which strongly supports the FR-dip model for filaments. The filament is stably sustained because the FR is weakly twisted and strongly confined by the overlying closed arcades.

  14. Modeling and experimental verification of a flat-plate solar photoreactor

    International Nuclear Information System (INIS)

    Rossetti, G.H.; Consejo Nacional de Investigaciones Cientificas y Tecnicas, Santa Fe; Albizzati, E.D.; Alfano, O.M.

    1998-01-01

    The utilization of the ultraviolet (UV) portion of the solar spectrum to drive the chemical destruction of organic pollutants in contaminated air and wastewaters has gained an increasing interest in the last two decades. A nonconcentrating, flat-plate solar photoreactor has been modeled and experimentally verified. The mathematical model considers that the reactor glass window receives direct and diffuse (isotropic) solar radiation. The model was solved numerically and predictions were compared with photodecomposition rate data, employing the uranyl oxalate actinometer. The reaction was conducted in an isothermal, perfectly mixed reactor placed inside a batch recycling system. The experimental values were compared with theoretical predictions and good agreement was obtained, the maximum deviation being 12%. The effect of the actinometer concentration and of the solar zenith angles (for horizontal and tilted reactors) on the actinometer decomposition rate was investigated. Results indicated that the uranyl oxalate reaction rate increases when (1) the initial actinometer concentration increases at almost constant solar zenith angle and (2) the zenith angle decreases at the same initial actinometer concentration

  15. Dynamics of Large-Scale Solar-Wind Streams Obtained by the Double Superposed Epoch Analysis: 2. Comparisons of CIRs vs. Sheaths and MCs vs. Ejecta

    Science.gov (United States)

    Yermolaev, Y. I.; Lodkina, I. G.; Nikolaeva, N. S.; Yermolaev, M. Y.

    2017-12-01

    This work is a continuation of our previous article (Yermolaev et al. in J. Geophys. Res. 120, 7094, 2015), which describes the average temporal profiles of interplanetary plasma and field parameters in large-scale solar-wind (SW) streams: corotating interaction regions (CIRs), interplanetary coronal mass ejections (ICMEs including both magnetic clouds (MCs) and ejecta), and sheaths as well as interplanetary shocks (ISs). As in the previous article, we use the data of the OMNI database, our catalog of large-scale solar-wind phenomena during 1976 - 2000 (Yermolaev et al. in Cosmic Res., 47, 2, 81, 2009) and the method of double superposed epoch analysis (Yermolaev et al. in Ann. Geophys., 28, 2177, 2010a). We rescale the duration of all types of structures in such a way that the beginnings and endings for all of them coincide. We present new detailed results comparing pair phenomena: 1) both types of compression regions ( i.e. CIRs vs. sheaths) and 2) both types of ICMEs (MCs vs. ejecta). The obtained data allow us to suggest that the formation of the two types of compression regions responds to the same physical mechanism, regardless of the type of piston (high-speed stream (HSS) or ICME); the differences are connected to the geometry ( i.e. the angle between the speed gradient in front of the piston and the satellite trajectory) and the jumps in speed at the edges of the compression regions. In our opinion, one of the possible reasons behind the observed differences in the parameters in MCs and ejecta is that when ejecta are observed, the satellite passes farther from the nose of the area of ICME than when MCs are observed.

  16. Solar Water Splitting Using Semiconductor Photocatalyst Powders

    KAUST Repository

    Takanabe, Kazuhiro

    2015-01-01

    Solar energy conversion is essential to address the gap between energy production and increasing demand. Large scale energy generation from solar energy can only be achieved through equally large scale collection of the solar spectrum. Overall water

  17. Analysis of width/height ratio and gingival zenith in patients with bilateral agenesis of maxillary lateral incisor

    Directory of Open Access Journals (Sweden)

    Núbia Inocencya Pavesi Pini

    2012-10-01

    Full Text Available OBJECTIVE: The purpose of this study was to evaluate the width/length ratio and the gingival zenith (GZ, by means of dental casts and digital caliper, in patients with missing maxillary lateral incisors after treatment. METHODS: The sample was composed of 52 subjects divided into 3 groups: BRG (n = 18, patients with bilateral agenesis treated with tooth re-contouring; BIG (n = 10 patients with agenesis treated with implants and CG (n = 24, control group. The data were analyzed using Shapiro-Wilk, Spearman correlation, Wilcoxon, Kruskal-Wallis, t test and ANOVA tests (p 0.05. GZ data for the right and left sides of the smile were not considered statistically different. CONCLUSION: Although no statistical difference was found in the comparison between the groups, analysis of the descriptive values showed that group BIG showed the greatest difference in values with regard to width/length ratio. Regarding gingival zenith, BRG showed the greatest difference.OBJETIVO: o propósito desse estudo foi analisar, por meio de modelos de estudo e paquímetro digital, a proporção largura/altura e o zênite gengival (ZG em pacientes com agenesia bilateral do incisivo lateral superior após o tratamento. MÉTODOS: a amostra consistiu de 52 voluntários divididos em 3 grupos: GBR (n=18, pacientes com agenesia bilateral tratados com reanatomizações dentárias; GBI (n=10, pacientes com agenesia bilateral tratados com implantes; e GC (n=24, grupo controle. Os dados foram avaliados por meio dos testes de Shapiro-Wilk, Wilcoxon, Kruskal-Wallis, teste t, ANOVA (p0,05. Os valores obtidos para os lados direito e esquerdo foram considerados iguais dentro de cada grupo. CONCLUSÃO: embora não tenham sido encontradas diferenças estatísticas na comparação entre os grupos, pela análise descritiva dos dados, o GBI foi o grupo que apresentou as medidas mais destoantes dos demais em relação à proporção largura/altura, sendo que, para o zênite gengival, a maior

  18. Application of Satellite Solar-Induced Chlorophyll Fluorescence to Understanding Large-Scale Variations in Vegetation Phenology and Function Over Northern High Latitude Forests

    Science.gov (United States)

    Jeong, Su-Jong; Schimel, David; Frankenberg, Christian; Drewry, Darren T.; Fisher, Joshua B.; Verma, Manish; Berry, Joseph A.; Lee, Jung-Eun; Joiner, Joanna

    2016-01-01

    This study evaluates the large-scale seasonal phenology and physiology of vegetation over northern high latitude forests (40 deg - 55 deg N) during spring and fall by using remote sensing of solar-induced chlorophyll fluorescence (SIF), normalized difference vegetation index (NDVI) and observation-based estimate of gross primary productivity (GPP) from 2009 to 2011. Based on GPP phenology estimation in GPP, the growing season determined by SIF time-series is shorter in length than the growing season length determined solely using NDVI. This is mainly due to the extended period of high NDVI values, as compared to SIF, by about 46 days (+/-11 days), indicating a large-scale seasonal decoupling of physiological activity and changes in greenness in the fall. In addition to phenological timing, mean seasonal NDVI and SIF have different responses to temperature changes throughout the growing season. We observed that both NDVI and SIF linearly increased with temperature increases throughout the spring. However, in the fall, although NDVI linearly responded to temperature increases, SIF and GPP did not linearly increase with temperature increases, implying a seasonal hysteresis of SIF and GPP in response to temperature changes across boreal ecosystems throughout their growing season. Seasonal hysteresis of vegetation at large-scales is consistent with the known phenomena that light limits boreal forest ecosystem productivity in the fall. Our results suggest that continuing measurements from satellite remote sensing of both SIF and NDVI can help to understand the differences between, and information carried by, seasonal variations vegetation structure and greenness and physiology at large-scales across the critical boreal regions.

  19. Reconstruction of solar spectral surface UV irradiances using radiative transfer simulations.

    Science.gov (United States)

    Lindfors, Anders; Heikkilä, Anu; Kaurola, Jussi; Koskela, Tapani; Lakkala, Kaisa

    2009-01-01

    UV radiation exerts several effects concerning life on Earth, and spectral information on the prevailing UV radiation conditions is needed in order to study each of these effects. In this paper, we present a method for reconstruction of solar spectral UV irradiances at the Earth's surface. The method, which is a further development of an earlier published method for reconstruction of erythemally weighted UV, relies on radiative transfer simulations, and takes as input (1) the effective cloud optical depth as inferred from pyranometer measurements of global radiation (300-3000 nm); (2) the total ozone column; (3) the surface albedo as estimated from measurements of snow depth; (4) the total water vapor column; and (5) the altitude of the location. Reconstructed daily cumulative spectral irradiances at Jokioinen and Sodankylä in Finland are, in general, in good agreement with measurements. The mean percentage difference, for instance, is mostly within +/-8%, and the root mean square of the percentage difference is around 10% or below for wavelengths over 310 nm and daily minimum solar zenith angles (SZA) less than 70 degrees . In this study, we used pseudospherical radiative transfer simulations, which were shown to improve the performance of our method under large SZA (low Sun).

  20. A new software suite for NO2 vertical profile retrieval from ground-based zenith-sky spectrometers

    International Nuclear Information System (INIS)

    Denis, L.; Roscoe, H.K.; Chipperfield, M.P.; Roozendael, M. van; Goutail, F.

    2005-01-01

    Here we present an operational method to improve accuracy and information content of ground-based measurements of stratospheric NO 2 . The motive is to improve the investigation of trends in NO 2 , and is important because the current trend in NO 2 appears to contradict the trend in its source, suggesting that the stratospheric circulation has changed. To do so, a new software package for retrieving NO 2 vertical profiles from slant columns measured by zenith-sky spectrometers has been created. It uses a Rodgers optimal linear inverse method coupled with a radiative transfer model for calculations of transfer functions between profiles and columns, and a chemical box model for taking into account the NO 2 variations during twilight and during the day. Each model has parameters that vary according to season and location. Forerunners of each model have been previously validated. The scheme maps random errors in the measurements and systematic errors in the models and their parameters on to the retrieved profiles. Initialisation for models is derived from well-established climatologies. The software has been tested by comparing retrieved profiles to simultaneous balloon-borne profiles at mid-latitudes in spring

  1. Estimation of the sea level muon spectra at different zenith angles below 10 TeV energy

    CERN Document Server

    Mitra, M; Pal, P B; Bhattacharya, D P

    2001-01-01

    The moderate energy primary cosmic ray nucleon spectrum has been calculated from the direct measurements of Webber et al. (1987), Seo et al. (1992) and Menn et al. (1997). Along with the other results surveyed by Swordy (1993). Using these directly measured primary mass composition results all particle primary nucleon energy spectrum has been constructed using superposition model to estimate the energy spectra of muons from the decay of the cosmic ray non-prompt and prompt mesons in the atmosphere. The Z-factors have been estimated from the CERN LEBC-EHS on the Lorentz invariant cross section results on pp to pi /sup +or-/X and pp to K/sup +or-/X inclusive reactions and FNAL data on pi /sup +or-/p to pi /sup +or-/X reactions, and duly corrected for A-A collisions. Using these Z-factors the meson energy spectra in the atmosphere have been calculated. The sea level muon energy spectra at zenith angles 0 degrees , 45 degrees , 72 degrees , and 75 degrees have been derived from the decay of non-prompt mesons by a...

  2. A new software suite for NO{sub 2} vertical profile retrieval from ground-based zenith-sky spectrometers

    Energy Technology Data Exchange (ETDEWEB)

    Denis, L. [British Antarctic Survey/NERC, Madingley Road, Cambridge CB3 0ET (United Kingdom); Roscoe, H.K. [British Antarctic Survey/NERC, Madingley Road, Cambridge CB3 0ET (United Kingdom)]. E-mail: h.roscoe@bas.ac.uk; Chipperfield, M.P. [Environment Centre, University of Leeds, Leeds LS2 9JT (United Kingdom); Roozendael, M. van [Belgian Institute for Space Aeronomy (BIRA/IASB), 1180 Brussels (Belgium); Goutail, F. [Service d' Aeronomie du CNRS, BP3, 91271 Verrieres le Buisson (France)

    2005-05-15

    Here we present an operational method to improve accuracy and information content of ground-based measurements of stratospheric NO{sub 2}. The motive is to improve the investigation of trends in NO{sub 2}, and is important because the current trend in NO{sub 2} appears to contradict the trend in its source, suggesting that the stratospheric circulation has changed. To do so, a new software package for retrieving NO{sub 2} vertical profiles from slant columns measured by zenith-sky spectrometers has been created. It uses a Rodgers optimal linear inverse method coupled with a radiative transfer model for calculations of transfer functions between profiles and columns, and a chemical box model for taking into account the NO{sub 2} variations during twilight and during the day. Each model has parameters that vary according to season and location. Forerunners of each model have been previously validated. The scheme maps random errors in the measurements and systematic errors in the models and their parameters on to the retrieved profiles. Initialisation for models is derived from well-established climatologies. The software has been tested by comparing retrieved profiles to simultaneous balloon-borne profiles at mid-latitudes in spring.

  3. A large-scale solar greenhouse dryer using polycarbonate cover: Modeling and testing in a tropical environment of Lao People's Democratic Republic

    Energy Technology Data Exchange (ETDEWEB)

    Janjai, Serm; Intawee, Poolsak; Kaewkiew, Jinda; Sritus, Chanoke [Solar Energy Research Laboratory, Department of Physics, Faculty of Science, Silpakorn University, Nakhon Pathom 73000 (Thailand); Khamvongsa, Vathsana [Department of Physics, Faculty of Natural Science, National University of Laos, P O Box 7322, Vientiane (Lao People' s Democratic Republic)

    2011-03-15

    A large-scale solar greenhouse dryer with a loading capacity of 1000 kg of fruits or vegetables has been developed and tested at field levels. The dryer has a parabolic shape and the dryer is covered with polycarbonate sheets. The base of the dryer is a black concrete floor with an area of 7.5 x 20.0 m{sup 2}. Nine DC fans powered by three 50-W solar cell modules are used to ventilate the dryer. The dryer was installed at Champasak (15.13 N, 105.79 E) in Lao People's Democratic Republic (Lao PDR). It is routinely used to dry chilli, banana and coffee. To assess the experimental performances of the dryer, air temperature, air relative humidity and product moisture contents were measured. One thousand kilograms of banana with the initial moisture content of 68% (wb) was dried within 5 days, compared to 7 days required for natural sun drying with the same weather conditions. Also three hundred kilograms of chilli with the initial moisture content of 75% (wb) was dried within 3 days while the natural sun drying needed 5 days. Two hundred kilograms of coffee with the initial moisture content of 52% (wb) was dried within 2 days as compared to 4 days required for natural sun drying. The chilli, coffee and banana dried in this dryer were completely protected from insects, animals and rain. Furthermore, good quality of dried products was obtained. The payback period of the dryer is estimated to be 2.5 years. A system of partial differential equations describing heat and moisture transfer during drying of chilli, coffee and banana in the greenhouse dryer was developed. These equations were solved by using the finite different method. The simulated results agree well with the experimental data. This model can be used to provide the design data for this type of dryer in other locations. (author)

  4. Time-scale and extent at which large-scale circulation modes determine the wind and solar potential in the Iberian Peninsula

    International Nuclear Information System (INIS)

    Jerez, Sonia; Trigo, Ricardo M

    2013-01-01

    The North Atlantic Oscillation (NAO), the East Atlantic (EA) and the Scandinavian (SCAND) modes are the three main large-scale circulation patterns driving the climate variability of the Iberian Peninsula. This study assesses their influence in terms of solar (photovoltaic) and wind power generation potential (SP and WP) and evaluates their skill as predictors. For that we use a hindcast regional climate simulation to retrieve the primary meteorological variables involved, surface solar radiation and wind speed. First we identify that the maximum influence of the various modes occurs on the interannual variations of the monthly mean SP and WP series, being generally more relevant in winter. Second we find that in this time-scale and season, SP (WP) varies up to 30% (40%) with respect to the mean climatology between years with opposite phases of the modes, although the strength and the spatial distribution of the signals differ from one month to another. Last, the skill of a multi-linear regression model (MLRM), built using the NAO, EA and SCAND indices, to reconstruct the original wintertime monthly series of SP and WP was investigated. The reconstructed series (when the MLRM is calibrated for each month individually) correlate with the original ones up to 0.8 at the interannual time-scale. Besides, when the modeled series for each individual month are merged to construct an October-to-March monthly series, and after removing the annual cycle in order to account for monthly anomalies, these correlate 0.65 (0.55) with the original SP (WP) series in average. These values remain fairly stable when the calibration and reconstruction periods differ, thus supporting up to a point the predictive potential of the method at the time-scale assessed here. (letter)

  5. Gram-scale synthesis of catalytic Co9S8 nanocrystal ink as a cathode material for spray-deposited, large-area dye-sensitized solar cells.

    Science.gov (United States)

    Chang, Shu-Hao; Lu, Ming-De; Tung, Yung-Liang; Tuan, Hsing-Yu

    2013-10-22

    We report the development of Co9S8 nanocrystals as a cost-effective cathode material that can be readily combined with spraying techniques to fabricate large-area dye-sensitized solar cell (DSSC) devices and can be further connected with series or parallel cell architectures to obtain a relatively high output voltage or current. A gram-scale synthesis of Co9S8 nanocrystal is carried out via a noninjection reaction by mixing anhydrous CoCl2 with trioctylphosphine (TOP), dodecanethiol and oleylamine (OLA) at 250 °C. The Co9S8 nanocrystals possess excellent catalytic ability with respect to I(-)/I3(-) redox reactions. The Co9S8 nanocrystals are prepared as nanoinks to fabricate uniform, crack-free Co9S8 thin films on different substrates by using a spray deposition technique. These Co9S8 films are used as counter electrodes assembled with dye-adsorbed TiO2 photoanodes to fabricate DSSC devices having a working area of 2 cm(2) and an average power conversion efficiency (PCE) of 7.02 ± 0.18% under AM 1.5 solar illumination, which is comparable with the PCE of 7.2 ± 0.12% obtained using a Pt cathode. Furthermore, six 2 cm(2)-sized DSSC devices connected in series output an open-circuit voltage of 4.2 V that can power a wide range of electronic devices such as LED arrays and can charge commercial lithium ion batteries.

  6. Continuous Czochralski growth: Silicon sheet growth development of the large area silicon sheet task of the Low Cost Silicon Solar Array project

    Science.gov (United States)

    1978-01-01

    The primary objective of this contract is to develop equipment and methods for the economic production of single crystal ingot material by the continuous Czochralski (CZ) process. Continuous CZ is defined for the purpose of this work as the growth of at least 100 kilograms of ingot from only one melt container. During the reporting period (October, 1977 - September, 1978), a modified grower was made fully functional and several recharge runs were performed. The largest run lasted 44 hours and over 42 kg of ingot was produced. Little, if any, degradation in efficiency was observed as a result of pulling multiple crystals from one crucible. Solar efficiencies observed were between 9.3 and 10.4% AMO (13.0 and 14.6% AMI) compared to 10.5% (14.7% AMI) for optimum CZ material control samples. Using the SAMICS/IPEG format, economic analysis of continuous CZ suggests that 1986 DoE cost goals can only be met by the growth of large diameter, large mass crystals.

  7. NONLINEAR FORCE-FREE FIELD EXTRAPOLATION OF A CORONAL MAGNETIC FLUX ROPE SUPPORTING A LARGE-SCALE SOLAR FILAMENT FROM A PHOTOSPHERIC VECTOR MAGNETOGRAM

    Energy Technology Data Exchange (ETDEWEB)

    Jiang, Chaowei; Wu, S. T.; Hu, Qiang [Center for Space Plasma and Aeronomic Research, The University of Alabama in Huntsville, Huntsville, AL 35899 (United States); Feng, Xueshang, E-mail: cwjiang@spaceweather.ac.cn, E-mail: wus@uah.edu, E-mail: qh0001@uah.edu, E-mail: fengx@spaceweather.ac.cn [SIGMA Weather Group, State Key Laboratory for Space Weather, Center for Space Science and Applied Research, Chinese Academy of Sciences, Beijing 100190 (China)

    2014-05-10

    Solar filaments are commonly thought to be supported in magnetic dips, in particular, in those of magnetic flux ropes (FRs). In this Letter, based on the observed photospheric vector magnetogram, we implement a nonlinear force-free field (NLFFF) extrapolation of a coronal magnetic FR that supports a large-scale intermediate filament between an active region and a weak polarity region. This result is a first, in the sense that current NLFFF extrapolations including the presence of FRs are limited to relatively small-scale filaments that are close to sunspots and along main polarity inversion lines (PILs) with strong transverse field and magnetic shear, and the existence of an FR is usually predictable. In contrast, the present filament lies along the weak-field region (photospheric field strength ≲ 100 G), where the PIL is very fragmented due to small parasitic polarities on both sides of the PIL and the transverse field has a low signal-to-noise ratio. Thus, extrapolating a large-scale FR in such a case represents a far more difficult challenge. We demonstrate that our CESE-MHD-NLFFF code is sufficient for the challenge. The numerically reproduced magnetic dips of the extrapolated FR match observations of the filament and its barbs very well, which strongly supports the FR-dip model for filaments. The filament is stably sustained because the FR is weakly twisted and strongly confined by the overlying closed arcades.

  8. Low-Temperature Preparation of Tungsten Oxide Anode Buffer Layer via Ultrasonic Spray Pyrolysis Method for Large-Area Organic Solar Cells

    Directory of Open Access Journals (Sweden)

    Ran Ji

    2017-07-01

    Full Text Available Tungsten oxide (WO3 is prepared by a low-temperature ultrasonic spray pyrolysis method in air atmosphere, and it is used as an anode buffer layer (ABL for organic solar cells (OSCs. The properties of the WO3 transition metal oxide material as well as the mechanism of ultrasonic spray pyrolysis processes are investigated. The results show that the ultrasonic spray pyrolysized WO3 ABL exhibits low roughness, matched energy level, and high conductivity, which results in high charge transport efficiency and suppressive recombination in OSCs. As a result, compared to the OSCs based on vacuum thermal evaporated WO3, a higher power conversion efficiency of 3.63% is reached with low-temperature ultrasonic spray pyrolysized WO3 ABL. Furthermore, the mostly spray-coated OSCs with large area was fabricated, which has a power conversion efficiency of ~1%. This work significantly enhances our understanding of the preparation and application of low temperature-processed WO3, and highlights the potential of large area, all spray coated OSCs for sustainable commercial fabrication.

  9. Low-Temperature Preparation of Tungsten Oxide Anode Buffer Layer via Ultrasonic Spray Pyrolysis Method for Large-Area Organic Solar Cells.

    Science.gov (United States)

    Ji, Ran; Zheng, Ding; Zhou, Chang; Cheng, Jiang; Yu, Junsheng; Li, Lu

    2017-07-18

    Tungsten oxide (WO₃) is prepared by a low-temperature ultrasonic spray pyrolysis method in air atmosphere, and it is used as an anode buffer layer (ABL) for organic solar cells (OSCs). The properties of the WO₃ transition metal oxide material as well as the mechanism of ultrasonic spray pyrolysis processes are investigated. The results show that the ultrasonic spray pyrolysized WO₃ ABL exhibits low roughness, matched energy level, and high conductivity, which results in high charge transport efficiency and suppressive recombination in OSCs. As a result, compared to the OSCs based on vacuum thermal evaporated WO₃, a higher power conversion efficiency of 3.63% is reached with low-temperature ultrasonic spray pyrolysized WO₃ ABL. Furthermore, the mostly spray-coated OSCs with large area was fabricated, which has a power conversion efficiency of ~1%. This work significantly enhances our understanding of the preparation and application of low temperature-processed WO₃, and highlights the potential of large area, all spray coated OSCs for sustainable commercial fabrication.

  10. ARGO-YBJ OBSERVATION OF THE LARGE-SCALE COSMIC RAY ANISOTROPY DURING THE SOLAR MINIMUM BETWEEN CYCLES 23 AND 24

    Energy Technology Data Exchange (ETDEWEB)

    Bartoli, B.; Catalanotti, S.; Piazzoli, B. D’Ettorre; Girolamo, T. Di [Dipartimento di Fisica dell’Università di Napoli “Federico II”, Complesso Universitario di Monte Sant’Angelo, via Cinthia, I-80126 Napoli (Italy); Bernardini, P.; D’Amone, A.; Mitri, I. De [Dipartimento Matematica e Fisica ”Ennio De Giorgi”, Università del Salento, via per Arnesano, I-73100 Lecce (Italy); Bi, X. J.; Cao, Z.; Chen, S. Z.; Feng, Zhaoyang; Gou, Q. B. [Key Laboratory of Particle Astrophysics, Institute of High Energy Physics, Chinese Academy of Sciences, P.O. Box 918, 100049 Beijing (China); Chen, T. L.; Danzengluobu [Tibet University, 850000 Lhasa, Xizang (China); Cui, S. W.; Gao, W. [Hebei Normal University, 050024, Shijiazhuang Hebei (China); Dai, B. Z. [Yunnan University, 2 North Cuihu Road, 650091 Kunming, Yunnan (China); Sciascio, G. Di [Istituto Nazionale di Fisica Nucleare, Sezione di Roma Tor Vergata, via della Ricerca Scientifica 1, I-00133 Roma (Italy); Feng, C. F. [Shandong University, 250100 Jinan, Shandong (China); Feng, Zhenyong, E-mail: cuisw@ihep.ac.cn [Southwest Jiaotong University, 610031 Chengdu, Sichuan (China); Collaboration: ARGO-YBJ Collaboration; and others

    2015-08-10

    This paper reports on the measurement of the large-scale anisotropy in the distribution of cosmic-ray arrival directions using the data collected by the air shower detector ARGO-YBJ from 2008 January to 2009 December, during the minimum of solar activity between cycles 23 and 24. In this period, more than 2 × 10{sup 11} showers were recorded with energies between ∼1 and 30 TeV. The observed two-dimensional distribution of cosmic rays is characterized by two wide regions of excess and deficit, respectively, both of relative intensity ∼10{sup −3} with respect to a uniform flux, superimposed on smaller size structures. The harmonic analysis shows that the large-scale cosmic-ray relative intensity as a function of R.A. can be described by the first and second terms of a Fouries series. The high event statistics allow the study of the energy dependence of the anistropy, showing that the amplitude increases with energy, with a maximum intensity at ∼10 TeV, and then decreases while the phase slowly shifts toward lower values of R.A. with increasing energy. The ARGO-YBJ data provide accurate observations over more than a decade of energy around this feature of the anisotropy spectrum.

  11. Link between local scale BC emissions in the Indo-Gangetic Plains and large scale atmospheric solar absorption

    Directory of Open Access Journals (Sweden)

    P. S. Praveen

    2012-01-01

    Full Text Available Project Surya has documented indoor and outdoor concentrations of black carbon (BC from traditional biomass burning cook stoves in a rural village located in the Indo-Gangetic Plains (IGP region of N. India from November 2009–September 2010. In this paper, we systematically document the link between local scale aerosol properties and column averaged regional aerosol optical properties and atmospheric radiative forcing. We document observations from the first phase of Project Surya and estimate the source dependent (biomass and fossil fuels aerosol optical properties from local to regional scale. Data were collected using surface based observations of BC, organic carbon (OC, aerosol light absorption, scattering coefficient at the Surya village (SVI_1 located in IGP region and integrated with satellite and AERONET observations at the regional scale (IGP. The daily mean BC concentrations at SVI_1 showed a large increase of BC during the dry season (December to February with values reaching 35 μg m−3. Space based LIDAR data revealed how the biomass smoke was trapped within the first kilometer during the dry season and extended to above 5 km during the pre-monsoon season. As a result, during the dry season, the variance in the daily mean single scattering albedo (SSA, the ratio of scattering to extinction coefficient, and column aerosol optical properties at the local IGP site correlated (with slopes in the range of 0.85 to 1.06 and R2>0.4 well with the "IGP_AERONET" (mean of six AERONET sites. The statistically significant correlation suggested that in-situ observations can be used to derive spatial mean forcing, at least for the dry season. The atmospheric forcing due to BC and OC exceeded 20 Wm−2 during all months from November to May, supporting the deduction that elimination of cook stove smoke emissions through clean cooking technologies will likely have a major positive impact not only on human

  12. A Preliminary Analysis of Solar Irradiance Measurements at TNB Solar Research Centre for Optimal Orientation of Fixed Solar Panels installed in Selangor Malaysia

    International Nuclear Information System (INIS)

    Hashim, A M; Ahmad, B; Shafie, R M; Rusli, R; Aziz, M A; Hassan, J; Wanik, M Z C; Ali, M A M

    2013-01-01

    The well established rule for orienting fixed solar devices is to face south for places in the northern hemisphere and northwards for the southern hemisphere. However for regions near the equator such as in Selangor Malaysia, the position of the sun at solar noon is always near zenith both to the north and south depending on location and month of year. This paper reports an analysis of global solar radiation data taken at TNB Solar Research Centre, Malaysia. The solar radiation is measured using both shaded and exposed pyranometers together with a pyrheliometer which is mounted on a sun-tracker. The analysis on the solar measurements show that a near regular solar irradiation pattern had occurred often enough during the year to recommend an optimum azimuth orientation of installing the fixed solar panels tilted facing towards east. Even though all the solar measurements were done at a single location in TNBR Solar Research Centre at Bangi, for locations near the equator with similar weather pattern, the recommended azimuth direction of installing fixed solar panels and collectors tilted eastward will also be generally valid.

  13. Tracking strategy for photovoltaic solar systems in high latitudes

    International Nuclear Information System (INIS)

    Quesada, Guillermo; Guillon, Laura; Rousse, Daniel R.; Mehrtash, Mostafa; Dutil, Yvan; Paradis, Pierre-Luc

    2015-01-01

    Highlights: • In cloudy conditions tracking the sun is ineffective. • A methodology to estimate a theoretical threshold for solar tracking was developed. • A tracking strategy to maximize electricity production was proposed. - Abstract: Several studies show that from about 20% to 50% more solar energy can be recovered by using photovoltaic systems that track the sun rather than systems set at a fixed angle. For overcast or cloudy days, recent studies propose the use of a set position in which each photovoltaic panel faces toward the zenith (horizontal position). Compared to a panel that follows the sun’s path, this approach claims that a horizontal panel increases the amount of solar radiation captured and subsequently the quantity of electricity produced. The present work assesses a solar tracking photovoltaic panel hourly and seasonally in high latitudes. A theoretical method based on an isotropic sky model was formulated, implemented, and used in a case study analysis of a grid-connected photovoltaic system in Montreal, Canada. The results obtained, based on the definition of a critical hourly global solar radiation, were validated numerically and experimentally. The study confirmed that a zenith-set sun tracking strategy for overcast or mostly cloudy days in summer is not advantageous

  14. Sequential deposition as a route to high-performance perovskite-sensitized solar cells

    KAUST Repository

    Burschka, Julian

    2013-07-10

    Following pioneering work, solution-processable organic-inorganic hybrid perovskites - such as CH 3 NH 3 PbX 3 (X = Cl, Br, I) - have attracted attention as light-harvesting materials for mesoscopic solar cells. So far, the perovskite pigment has been deposited in a single step onto mesoporous metal oxide films using a mixture of PbX 2 and CH 3 NH 3 X in a common solvent. However, the uncontrolled precipitation of the perovskite produces large morphological variations, resulting in a wide spread of photovoltaic performance in the resulting devices, which hampers the prospects for practical applications. Here we describe a sequential deposition method for the formation of the perovskite pigment within the porous metal oxide film. PbI 2 is first introduced from solution into a nanoporous titanium dioxide film and subsequently transformed into the perovskite by exposing it to a solution of CH 3 NH 3 I. We find that the conversion occurs within the nanoporous host as soon as the two components come into contact, permitting much better control over the perovskite morphology than is possible with the previously employed route. Using this technique for the fabrication of solid-state mesoscopic solar cells greatly increases the reproducibility of their performance and allows us to achieve a power conversion efficiency of approximately 15 per cent (measured under standard AM1.5G test conditions on solar zenith angle, solar light intensity and cell temperature). This two-step method should provide new opportunities for the fabrication of solution-processed photovoltaic cells with unprecedented power conversion efficiencies and high stability equal to or even greater than those of today\\'s best thin-film photovoltaic devices. © 2013 Macmillan Publishers Limited. All rights reserved.

  15. The large-area CdTe thin film for CdS/CdTe solar cell prepared by physical vapor deposition in medium pressure

    Energy Technology Data Exchange (ETDEWEB)

    Luo, Run; Liu, Bo; Yang, Xiaoyan; Bao, Zheng; Li, Bing, E-mail: libing70@126.com; Zhang, Jingquan; Li, Wei; Wu, Lili; Feng, Lianghuan

    2016-01-01

    Graphical abstract: - Highlights: • The large-area CdTe film has been prepared by PVD under the pressure of 0.9 kPa. • The as-prepared CdTe thin film processes excellent photovoltaic properties. • This technique is suitable for depositing large-area CdTe thin film. • The 14.6% champion efficiency CdS/CdTe cell has been achieved. - Abstract: The Cadmium telluride (CdTe) thin film has been prepared by physical vapor deposition (PVD), the Ar + O{sub 2} pressure is about 0.9 kPa. This method is a newer technique to deposit CdTe thin film in large area, and the size of the film is 30 × 40 cm{sup 2}. This method is much different from the close-spaced sublimation (CSS), as the relevance between the source temperature and the substrate temperature is weak, and the gas phase of CdTe is transferred to the substrate by Ar + O{sub 2} flow. Through this method, the compact and uniform CdTe film (30 × 40 cm{sup 2}) has been achieved, and the performances of the CdTe thin film have been determined by transmission spectrum, SEM and XRD. The film is observed to be compact with a good crystallinity, the CdTe is polycrystalline with a cubic structure and a strongly preferred (1 1 1) orientation. Using the CdTe thin film (3 × 5 cm{sup 2}) which is taken from the deposited large-area film, the 14.6% efficiency CdS/CdTe thin film solar cell has been prepared successfully. The structure of the cell is glass/FTO/CdS/CdTe/graphite slurry/Au, short circuit current density (J{sub sc}) of the cell is 26.9 mA/cm{sup 2}, open circuit voltage (V{sub oc}) is 823 mV, and filling factor (FF) is 66.05%. This technique can be a quite promising method to apply in the industrial production, as it has great prospects in the fabricating of large-area CdTe film.

  16. Solar Adaptive Optics

    Directory of Open Access Journals (Sweden)

    Thomas R. Rimmele

    2011-06-01

    Full Text Available Adaptive optics (AO has become an indispensable tool at ground-based solar telescopes. AO enables the ground-based observer to overcome the adverse effects of atmospheric seeing and obtain diffraction limited observations. Over the last decade adaptive optics systems have been deployed at major ground-based solar telescopes and revitalized ground-based solar astronomy. The relatively small aperture of solar telescopes and the bright source make solar AO possible for visible wavelengths where the majority of solar observations are still performed. Solar AO systems enable diffraction limited observations of the Sun for a significant fraction of the available observing time at ground-based solar telescopes, which often have a larger aperture than equivalent space based observatories, such as HINODE. New ground breaking scientific results have been achieved with solar adaptive optics and this trend continues. New large aperture telescopes are currently being deployed or are under construction. With the aid of solar AO these telescopes will obtain observations of the highly structured and dynamic solar atmosphere with unprecedented resolution. This paper reviews solar adaptive optics techniques and summarizes the recent progress in the field of solar adaptive optics. An outlook to future solar AO developments, including a discussion of Multi-Conjugate AO (MCAO and Ground-Layer AO (GLAO will be given.

  17. Solar Adaptive Optics.

    Science.gov (United States)

    Rimmele, Thomas R; Marino, Jose

    Adaptive optics (AO) has become an indispensable tool at ground-based solar telescopes. AO enables the ground-based observer to overcome the adverse effects of atmospheric seeing and obtain diffraction limited observations. Over the last decade adaptive optics systems have been deployed at major ground-based solar telescopes and revitalized ground-based solar astronomy. The relatively small aperture of solar telescopes and the bright source make solar AO possible for visible wavelengths where the majority of solar observations are still performed. Solar AO systems enable diffraction limited observations of the Sun for a significant fraction of the available observing time at ground-based solar telescopes, which often have a larger aperture than equivalent space based observatories, such as HINODE. New ground breaking scientific results have been achieved with solar adaptive optics and this trend continues. New large aperture telescopes are currently being deployed or are under construction. With the aid of solar AO these telescopes will obtain observations of the highly structured and dynamic solar atmosphere with unprecedented resolution. This paper reviews solar adaptive optics techniques and summarizes the recent progress in the field of solar adaptive optics. An outlook to future solar AO developments, including a discussion of Multi-Conjugate AO (MCAO) and Ground-Layer AO (GLAO) will be given. Supplementary material is available for this article at 10.12942/lrsp-2011-2.

  18. Solar Photovoltaic Technology Basics | NREL

    Science.gov (United States)

    Photovoltaic Technology Basics Solar Photovoltaic Technology Basics Solar cells, also called found in sand) created an electric charge when exposed to sunlight. Soon solar cells were being used to power space satellites and smaller items like calculators and watches. Photo of a large silicon solar

  19. Analysing the Zenith Tropospheric Delay Estimates in On-line Precise Point Positioning (PPP) Services and PPP Software Packages.

    Science.gov (United States)

    Mendez Astudillo, Jorge; Lau, Lawrence; Tang, Yu-Ting; Moore, Terry

    2018-02-14

    As Global Navigation Satellite System (GNSS) signals travel through the troposphere, a tropospheric delay occurs due to a change in the refractive index of the medium. The Precise Point Positioning (PPP) technique can achieve centimeter/millimeter positioning accuracy with only one GNSS receiver. The Zenith Tropospheric Delay (ZTD) is estimated alongside with the position unknowns in PPP. Estimated ZTD can be very useful for meteorological applications, an example is the estimation of water vapor content in the atmosphere from the estimated ZTD. PPP is implemented with different algorithms and models in online services and software packages. In this study, a performance assessment with analysis of ZTD estimates from three PPP online services and three software packages is presented. The main contribution of this paper is to show the accuracy of ZTD estimation achievable in PPP. The analysis also provides the GNSS users and researchers the insight of the processing algorithm dependence and impact on PPP ZTD estimation. Observation data of eight whole days from a total of nine International GNSS Service (IGS) tracking stations spread in the northern hemisphere, the equatorial region and the southern hemisphere is used in this analysis. The PPP ZTD estimates are compared with the ZTD obtained from the IGS tropospheric product of the same days. The estimates of two of the three online PPP services show good agreement (<1 cm) with the IGS ZTD values at the northern and southern hemisphere stations. The results also show that the online PPP services perform better than the selected PPP software packages at all stations.

  20. Analysing the Zenith Tropospheric Delay Estimates in On-line Precise Point Positioning (PPP Services and PPP Software Packages

    Directory of Open Access Journals (Sweden)

    Jorge Mendez Astudillo

    2018-02-01

    Full Text Available As Global Navigation Satellite System (GNSS signals travel through the troposphere, a tropospheric delay occurs due to a change in the refractive index of the medium. The Precise Point Positioning (PPP technique can achieve centimeter/millimeter positioning accuracy with only one GNSS receiver. The Zenith Tropospheric Delay (ZTD is estimated alongside with the position unknowns in PPP. Estimated ZTD can be very useful for meteorological applications, an example is the estimation of water vapor content in the atmosphere from the estimated ZTD. PPP is implemented with different algorithms and models in online services and software packages. In this study, a performance assessment with analysis of ZTD estimates from three PPP online services and three software packages is presented. The main contribution of this paper is to show the accuracy of ZTD estimation achievable in PPP. The analysis also provides the GNSS users and researchers the insight of the processing algorithm dependence and impact on PPP ZTD estimation. Observation data of eight whole days from a total of nine International GNSS Service (IGS tracking stations spread in the northern hemisphere, the equatorial region and the southern hemisphere is used in this analysis. The PPP ZTD estimates are compared with the ZTD obtained from the IGS tropospheric product of the same days. The estimates of two of the three online PPP services show good agreement (<1 cm with the IGS ZTD values at the northern and southern hemisphere stations. The results also show that the online PPP services perform better than the selected PPP software packages at all stations.

  1. Endovascular abdominal aortic repair for AAA. Anatomical suitability and limitation in Japanese population according to the inclusion criteria of Zenith AAA stent graft

    International Nuclear Information System (INIS)

    Kitagawa, Atsushi; Okita, Yutaka; Okada, Kenji

    2009-01-01

    Since 2007, the EVAR (endovascular abdominal aortic repair) grafts, Zenith, Excluder and Powerlink had been commercially available in Japan. However, a small iliac artery, typical of Japanese population especially in women, was a limiting factor to indicate EVAR. We analyzed the suitability of EVAR in Japanese population according to the inclusion criteria of Zenith AAA stent graft in the current study. From January 2006 to December 2007, 106 AAA (abdominal aortic aneurysm) patients (88 men, 18 women) with a mean age of 73 years were investigated in our institution by multi-slice CT scan in terms of suitability of EVAR, then we measured their abdominal aorta and iliac artery parameters as follows; proximal neck diameter (PND) and length (PNL), common iliac artery diameter (CIAD) and length (CIAL), suprarenal (SNA) and infrarenal neck angulation (INA), external iliac artery diameter (EIAD) and aortic length from the lowest renal artery to the aortic bifurcation (AOL). The inclusion criteria for Zenith AAA stent graft treatment were; PND: 18-28 mm, PNL more than 15 mm, unilateral CIAD less than 20 mm, CIAL at least 10 mm, SNA less than 45 degree and INA less than 60 degree, unilateral EIAD more than 7.5 mm. The indication of EVAR was 25.5% (27/106 patients), and was especially very low in women (5.6%) strictly according to the inclusion criteria of the Zenith AAA stent graft. The main reason of exclusion of EVAR was proximal short neck (40.5%), small iliac artery (30.4%) and infrarenal aortic neck angulation (29.1%). In our analysis, female AAA patients had small PNL and EIAD with angulated neck compared with male AAA ones. Anatomical suitability of EVAR in Japanese population strictly following by the inclusion criteria of Zenith AAA stent graft was low due to their characteristic differences from the European Union (EU) and the United States (US) patients, such as short proximal neck, steep neck angulation and small iliac artery, especially in women. More flexible

  2. Operations Charioteer, Musketeer, Touchstone, Cornerstone, Aqueduct, Sculpin and Julin. Tests Mill Yard, Diamond Beech, Mighty Oak, Middle Note Mission Ghost, Mission Cyber, Misty Echo, Disko Elm, Mineral Quarry, Distant Zenith, Diamond Fortune, and Hunters Trophy

    National Research Council Canada - National Science Library

    Schoengold, Carole

    1999-01-01

    ...; Tests MILL YARD, DIAMOND BEECH, MIGHTY OAK, MIDDLE NOTE, MISSION GHOST, MISSION CYBER, MISTY ECHO, DISKO ELM, MINERAL QUARRY, DISTANT ZENITH, DIAMOND FORTUNE, and HUNTERS TROPHY, 9 October 1985 to 18 September 1992...

  3. Solar Indices - Solar Flares

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Collection includes a variety of indices related to solar activity contributed by a number of national and private solar observatories located worldwide. This...

  4. Solar Indices - Solar Ultraviolet

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Collection includes a variety of indices related to solar activity contributed by a number of national and private solar observatories located worldwide. This...

  5. Solar Indices - Solar Corona

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Collection includes a variety of indices related to solar activity contributed by a number of national and private solar observatories located worldwide. This...

  6. Solar Indices - Solar Irradiance

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Collection includes a variety of indices related to solar activity contributed by a number of national and private solar observatories located worldwide. This...

  7. Development of Tandem Amorphous/Microcrystalline Silicon Thin-Film Large-Area See-Through Color Solar Panels with Reflective Layer and 4-Step Laser Scribing for Building-Integrated Photovoltaic Applications

    Directory of Open Access Journals (Sweden)

    Chin-Yi Tsai

    2014-01-01

    Full Text Available In this work, tandem amorphous/microcrystalline silicon thin-film large-area see-through color solar modules were successfully designed and developed for building-integrated photovoltaic applications. Novel and key technologies of reflective layers and 4-step laser scribing were researched, developed, and introduced into the production line to produce solar panels with various colors, such as purple, dark blue, light blue, silver, golden, orange, red wine, and coffee. The highest module power is 105 W and the highest visible light transmittance is near 20%.

  8. Development of a Fast and Accurate PCRTM Radiative Transfer Model in the Solar Spectral Region

    Science.gov (United States)

    Liu, Xu; Yang, Qiguang; Li, Hui; Jin, Zhonghai; Wu, Wan; Kizer, Susan; Zhou, Daniel K.; Yang, Ping

    2016-01-01

    A fast and accurate principal component-based radiative transfer model in the solar spectral region (PCRTMSOLAR) has been developed. The algorithm is capable of simulating reflected solar spectra in both clear sky and cloudy atmospheric conditions. Multiple scattering of the solar beam by the multilayer clouds and aerosols are calculated using a discrete ordinate radiative transfer scheme. The PCRTM-SOLAR model can be trained to simulate top-of-atmosphere radiance or reflectance spectra with spectral resolution ranging from 1 cm(exp -1) resolution to a few nanometers. Broadband radiances or reflectance can also be calculated if desired. The current version of the PCRTM-SOLAR covers a spectral range from 300 to 2500 nm. The model is valid for solar zenith angles ranging from 0 to 80 deg, the instrument view zenith angles ranging from 0 to 70 deg, and the relative azimuthal angles ranging from 0 to 360 deg. Depending on the number of spectral channels, the speed of the current version of PCRTM-SOLAR is a few hundred to over one thousand times faster than the medium speed correlated-k option MODTRAN5. The absolute RMS error in channel radiance is smaller than 10(exp -3) mW/cm)exp 2)/sr/cm(exp -1) and the relative error is typically less than 0.2%.

  9. ATU/Fort Hood Solar Total Energy Military Large-Scale Experiment (LSE-1): system design and support activities. Final report, November 23, 1976-November 30, 1977

    Energy Technology Data Exchange (ETDEWEB)

    1977-01-01

    The ATU/Fort Hood Solar Total Energy System will include a concentrating solar collector field of several acres. During periods of direct insolation, a heat-transfer fluid will be circulated through the collector field and thus heated to 500 to 600/sup 0/F. Some of the fluid will be circulated through a steam generator to drive a turbine-generator set; additional fluid will be stored in insulated tanks for use when solar energy is not available. The electrical output will satisfy a portion of the electrical load at Fort Hood's 87,000 Troop Housing Complex. Heat extracted from the turbine exhaust in the form of hot water will be used for space heating, absorption air conditioning, and domestic water heating at the 87,000 Complex. Storage tanks for the hot water are also included. The systems analysis and program support activities include studies of solar availability and energy requirements at Fort Hood, investigation of interfacing LSE-1 with existing energy systems at the 87,000 Complex, and preliminary studies of environmental, health, and safety considerations. An extensive survey of available concentrating solar collectors and modifications to a computerized system simulation model for LSE-1 use are also reported. Important program support activities are military liaison and information dissemination. The engineering test program reported involved completion of the Solar Engineering Test Module (SETM) and extensive performance testing of a single module of the linear-focusing collector.

  10. Sensitivity of the photodissociation of NO2, NO3, HNO3 and H2O2 to the solar radiation diffused by the ground and by atmospheric particles

    International Nuclear Information System (INIS)

    Mugnai, A.; Petroncelli, P.; Fiocco, G.

    1979-01-01

    The diffusion of solar radiation by atmospheric molecules and aerosols and by ground albedo affects the photodissociation rates of atmospheric species relevant to the ozone chemistry. In this paper, a previous investigation on the photodissociation of O 3 is extended to NO 2 , NO 3 , HNO 3 , H 2 O 2 . Because of the different character of the absorption spectra of these species, the behaviour of photodissociation profiles with height and their sensitivity to such factors as ground albedo, aerosol loads, solar zenith angle are somewhat different. The results show that the presence of the aerosols usually enhances the photodissociation in the upper troposphere and in the stratosphere, because of scattering, but tends to reduce it at low heights because of the increased extinction. Enhancements in the photodissociation coefficients are as high as 20 to 40% for low values of the albedo and large aerosol loads such as those obtained after a volcanic eruption. On the other hand, at large values of the albedo, the effect of aerosols is mainly in attenuating the radiation going into and coming from the ground and their presence can lead to reduced photolysis even in the stratosphere. (author)

  11. Solar building

    OpenAIRE

    Zhang, Luxin

    2014-01-01

    In my thesis I describe the utilization of solar energy and solar energy with building integration. In introduction it is also mentioned how the solar building works, trying to make more people understand and accept the solar building. The thesis introduces different types of solar heat collectors. I compared the difference two operation modes of solar water heating system and created examples of solar water system selection. I also introduced other solar building applications. It is conv...

  12. Solar energy

    International Nuclear Information System (INIS)

    Anon.

    1992-01-01

    This chapter discusses the role solar energy may have in the energy future of the US. The topics discussed in the chapter include the solar resource, solar architecture including passive solar design and solar collectors, solar-thermal concentrating systems including parabolic troughs and dishes and central receivers, photovoltaic cells including photovoltaic systems for home use, and environmental, health and safety issues

  13. Optimal Site Selection of Wind-Solar Complementary Power Generation Project for a Large-Scale Plug-In Charging Station

    Directory of Open Access Journals (Sweden)

    Wenjun Chen

    2017-10-01

    Full Text Available The wind-solar hybrid power generation project combined with electric vehicle charging stations can effectively reduce the impact on the power system caused by the random charging of electric cars, contribute to the in-situ wind-solar complementary system and reduce the harm arising from its output volatility. In this paper, the site selection index system of a landscape complementary power generation project is established by using the statistical methods and statistical analysis in the literature. Subsequently, using the Analytic Network Process to calculate the index weight, a cloud model was used in combination with preference ranking organization method for enrichment evaluations to transform and sort uncertain language information. Finally, using the results of the decision-making for the location of the Shanghai wind-solar complementary project and by carrying out contrast analysis and sensitivity analysis, the superiority and stability of the decision model constructed in this study was demonstrated.

  14. Too large dimensions; Control problems at Camberg-West solar plant. Zu gross dimensioniert; Die Solaranlage Camberg-West hatte einige Regelungsschwierigkeiten

    Energy Technology Data Exchange (ETDEWEB)

    Anon,

    1993-08-01

    The solar-energy collector plant of the motoring restaurant service Stratin in Camberg thus been in operation for over 10 years. 5000 to 6000 litres of water is heated daily using a total collector panel of 192 m[sup 2]. Initial measurements showed that the solar-energy plant only contributed 13% of the total energy requirements of the water-heating process. The reasons for this were that the dimensions were too high, as incorrect pumping unit control as melt as exchanger surfaces which were too small. Modifications led to improvements in operational efficiency from 10 to 23% and in solar fraction from 13 to 31%. All of the other components have operated without any difficulties. (BWI)

  15. Solar heating of air used for the drying at medium and large scale, of forestry, fishery, agriculture, cattle and industrial products

    International Nuclear Information System (INIS)

    Gutierrez, F.

    1991-01-01

    The drying process and/or preservation of grains is improved through the previous heating of air. In many cases it is enough to raise the temperature only a few degrees (from 10 to 15 Centigrade), in order to increase their capacity to absorb dampness. This can be done using very simple solar captors. A massive use of solar energy in the drying process of products, by means of hot air, can only be done with very expensive equipment. For this reason, it is recommended the use of lower thermic heaters, which will have a lower cost too. (Author)

  16. Connectable solar air collectors

    Energy Technology Data Exchange (ETDEWEB)

    Oestergaard Jensen, S.; Bosanac, M.

    2002-02-01

    The project has proved that it is possible to manufacture solar air collector panels, which in an easy way can be connected into large collector arrays with integrated ducting without loss of efficiency. The developed connectable solar air collectors are based on the use of matrix absorbers in the form of perforated metal sheets. Three interconnected solar air collectors of the above type - each with an transparent area of approx. 3 m{sup 2} - was tested and compared with parallel tests on two single solar air collectors also with a transparent area of approx. 3 m{sup 2} One of the single solar air collectors has an identical absorber as the connectable solar air collectors while the absorber of the other single solar air collector was a fibre cloth. The efficiency of the three solar air collectors proved to be almost identical in the investigated range of mass flow rates and temperature differences. The solar air collectors further proved to be very efficient - as efficient as the second most efficient solar air collectors tested in the IEA task 19 project Solar Air Systems. Some problems remain although to be solved: the pressure drop across especially the connectable solar air collectors is too high - mainly across the inlets of the solar air collectors. It should, however, be possible to considerably reduce the pressure losses with a more aerodynamic design of the inlet and outlet of the solar air collectors; The connectable solar air collectors are easy connectable but the air tightness of the connections in the present form is not good enough. As leakage leads to lower efficiencies focus should be put on making the connections more air tight without loosing the easiness in connecting the solar air collectors. As a spin off of the project a simple and easy way to determine the efficiency of solar, air collectors for pre-heating of fresh air has been validated. The simple method of determining the efficiency has with success been compared with an advance method

  17. Solar flares

    International Nuclear Information System (INIS)

    Kaastra, J.S.

    1985-01-01

    In this thesis an electrodynamic model for solar flares is developed. The main theoretical achievements underlying the present study are treated briefly and the observable flare parameters are described within the framework of the flare model of this thesis. The flare model predicts large induced electric fields. Therefore, acceleration processes of charged particles by direct electric fields are treated. The spectrum of the accelerated particles in strong electric fields is calculated, 3 with the electric field and the magnetic field perpendicular and in the vicinity of an X-type magnetic neutral line. An electromagnetic field configuration arises in the case of a solar flare. A rising current filament in a quiescent background bipolar magnetic field causes naturally an X-type magnetic field configuration below the filament with a strong induced electric field perpendicular to the ambient magnetic field. This field configuration drives particles and magnetic energy towards the neutral line, where a current sheet is generated. The global evolution of the fields in the flare is determined by force balance of the Lorentz forces on the filament and the force balance on the current sheet. The X-ray, optical and radio observations of a large solar flare on May 16, 1981 are analyzed. It is found that these data fit the model very well. (Auth.)

  18. Large scale distribution of ultra high energy cosmic rays detected at the Pierre Auger observatory with zenith angles up to 80°

    Czech Academy of Sciences Publication Activity Database

    Aab, A.; Abreu, P.; Aglietta, M.; Boháčová, Martina; Chudoba, Jiří; Ebr, Jan; Mandát, Dušan; Nečesal, Petr; Palatka, Miroslav; Pech, Miroslav; Prouza, Michael; Řídký, Jan; Schovánek, Petr; Trávníček, Petr; Vícha, Jakub

    2015-01-01

    Roč. 802, č. 2 (2015), s. 111 ISSN 0004-637X R&D Projects: GA MŠk(CZ) LG13007; GA MŠk(CZ) 7AMB14AR005; GA ČR(CZ) GA14-17501S Institutional support: RVO:68378271 Keywords : astroparticle physics * cosmic rays Subject RIV: BF - Elementary Particles and High Energy Physics Impact factor: 5.909, year: 2015

  19. Meteoroid Measurements in the Deep Space Cruising and the Jupiter Trojan Rendezvous Phases of the Solar Power Sail Mission by the Arrayed Large-Area Dust Detectors in INterplanetary Space (ALADDIN)-II

    Science.gov (United States)

    Yano, H.; Hirai, T.; Arai, K.; Fujii, M.

    2017-12-01

    The PVDF thin films have been long, space-proven instruments for hypervelocity impact detection in the diverse regions of the Solar System from orbits of Venus by IKAROS and of Pluto by New Horizons. In particular, light weight but large area membranes of a solar sail spacecraft is an ideal location for such detectors to be deployed for detecting statistically enough nubers of so large micrometeoroids that are sensitive to mean motion resonances and other gravitational effects of flux enhancements and voids with planets. The IKAROS spacecraft first detected in situ dust flux enhancement and gap region within the Earth's circumsolar dust ring as well as those of Venus by 0.54 m^2 detection area of ALADDIN sensors on the slar sail membrane. Advancing this heritage, the Solar Power Sail membrane will carry 0.4+ m^2 ALADDIN-II PVDF sensors with improved impact signal prosessng units to detect both hyperveloity dust impacts in the interplanetary space cruising phase and slow dust impacts bound to the Jupiter Trojan region in its rendezvours phase.

  20. Solar Stereoscopy and Tomography

    Directory of Open Access Journals (Sweden)

    Markus J. Aschwanden

    2011-10-01

    Full Text Available We review stereoscopic and tomographic methods used in the solar corona, including ground-based and space-based measurements, using solar rotation or multiple spacecraft vantage points, in particular from the STEREO mission during 2007--2010. Stereoscopic and tomographic observations in the solar corona include large-scale structures, streamers, active regions, coronal loops, loop oscillations, acoustic waves in loops, erupting filaments and prominences, bright points, jets, plumes, flares, CME source regions, and CME-triggered global coronal waves. Applications in the solar interior (helioseismic tomography and reconstruction and tracking of CMEs from the outer corona and into the heliosphere (interplanetary CMEs are not included.

  1. Long Island Solar Farm

    Energy Technology Data Exchange (ETDEWEB)

    Anders, R.

    2013-05-01

    The Long Island Solar Farm (LISF) is a remarkable success story, whereby very different interest groups found a way to capitalize on unusual circumstances to develop a mutually beneficial source of renewable energy. The uniqueness of the circumstances that were necessary to develop the Long Island Solar Farm make it very difficult to replicate. The project is, however, an unparalleled resource for solar energy research, which will greatly inform large-scale PV solar development in the East. Lastly, the LISF is a superb model for the process by which the project developed and the innovation and leadership shown by the different players.

  2. Solar and interplanetary disturbances

    CERN Document Server

    Alurkar, S K

    1997-01-01

    Over the last three decades, a spate of solar wind observations have been made with sophisticated ground-based and space-borne instruments. Two highly successful space missions of the Skylab and the twin spacecraft Helios 1 and 2 have amassed an invaluable wealth of information on the large scale structure of the inner heliosphere, the solar and interplanetary magnetic field, coronal holes, interplanetary dust, solar windflows, etc.Solar and interplanetary propagating phenomena have been extensively studied during the last two decades. Very recently, a new simple model based on results from a

  3. Elite silicon and solar power

    International Nuclear Information System (INIS)

    Yasamanov, N.A.

    2000-01-01

    The article is of popular character, the following issues being considered: conversion of solar energy into electric one, solar batteries in space and on the Earth, growing of silicon large-size crystals, source material problems relating to silicon monocrystals production, outlooks of solar silicon batteries production [ru

  4. Mixed P25 nanoparticles and large rutile particles as a top scattering layer to enhance performance of nanocrystalline TiO{sub 2} based dye-sensitized solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Xiaohua, E-mail: mksxh@163.com; Zhou, Xin; Xu, Yalong; Sun, Panpan; Huang, Niu; Sun, Yihua

    2015-05-15

    Graphical abstract: - Highlights: • Mixed P25 nanoparticles and large rutile particles were employed to form a top scattering layer. • The top scattering layer exhibits superior light scattering effect. • The bottom nanocrystalline TiO{sub 2} layer can make good use of the back-scattered light. • Bilayer TiO{sub 2} photoanode shows faster interfacial electron transfer and slower charge recombination process. • Bilayer photoanode enhances the DSSC efficiency by a factor of 25%. - Abstract: Herein, we report a bilayer TiO{sub 2} photoanode composed of nanocrystalline TiO{sub 2} (NCT) bottom layer and mixed P25 nanoparticles and large rutile particles (PR) top scattering layer. The present structure performs well in solar light harvesting which is mainly attributed to the fact that the top scattering layer exhibits superior light scattering effect and meanwhile the NCT bottom layer with large dye-loading capacity can make better use of the back-scattered light. Moreover, electrochemical impedance spectroscopy and open circuit voltage decay measurements demonstrate that DSSC based on bilayer photoanode shows faster interfacial electron transfer and slower charge recombination process than that based on NCT monolayer photoanode. These advantages render the DSSCs based on NCT-PR bilayer photoanode exhibiting superior performance under AM1.5G simulated solar irradiation. As an example, by tuning mass ratio between P25 nanoparticles and large rutile particles in the top scattering layer, the DSSC based on NCT-PR bilayer photoanode exhibits an optimum solar energy conversion efficiency of 9.0%, which is about 1.25 times higher than that of monolayer NCT device (7.2%) with the same film thickness.

  5. Energetic particle, solar wind plasma and magnetic field measurements on board Prognoz-6 during the large scale interplanetary disturbance of Jan. 3-4, 1978

    International Nuclear Information System (INIS)

    Kurt, V.G.; Stolpovskij, V.G.; Gombosi, T.I.; Kecskemety, K.; Somogyi, J.; Gringauz, K.I.; Kotova, G.A.; Verigin, M.I.; Styazhkin, V.A.

    1980-05-01

    The interplanetary shock, generated during the solar flare of Jan. 1, 1978 reached the Earth's orbit on January 3, 21sup(h) UT. Aboard Prognoz-6 satellite the fluxes and spectra of energetic electron (E>30 keV) and proton (E>500 keV) fluxes and energy spectra of solar wind ions up to 4.5 keV and magnetic field were measured, with a time resolution approximately 10 sec. Time variation of these characteristics are given including preshock and postshock frequency spectra of magnetic field fluctuations. Effective acceleration of protons in the oblique shock was observed. The mean free path of protons with E<6 MeV was determined by using the time interval of anisotropic particle flux observations as lambda approximately 0.2 a.u. (author)

  6. Solar Features - Solar Flares

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A solar flare is a short-lived sudden increase in the intensity of radiation emitted in the neighborhood of sunspots. For many years it was best monitored in the...

  7. Solar storms; Tormentas solares

    Energy Technology Data Exchange (ETDEWEB)

    Collaboration: Pereira Cuesta, S.; Pereira Pagan, B.

    2016-08-01

    Solar storms begin with an explosion, or solar flare, on the surface of the sun. The X-rays and extreme ultraviolet radiation from the flare reach the Earths orbit minutes later-travelling at light speed. The ionization of upper layers of our atmosphere could cause radio blackouts and satellite navigation errors (GPS). Soon after, a wave of energetic particles, electrons and protons accelerated by the explosion crosses the orbit of the Earth, and can cause real and significant damage. (Author)

  8. Implementing Solar Technologies at Airports

    Energy Technology Data Exchange (ETDEWEB)

    Kandt, A.; Romero, R.

    2014-07-01

    Federal agencies, such as the Department of Defense and Department of Homeland Security, as well as numerous private entities are actively pursuing the installation of solar technologies to help reduce fossil fuel energy use and associated emissions, meet sustainability goals, and create more robust or reliable operations. One potential approach identified for siting solar technologies is the installation of solar energy technologies at airports and airfields, which present a significant opportunity for hosting solar technologies due to large amounts of open land. This report focuses largely on the Federal Aviation Administration's (FAA's) policies toward siting solar technologies at airports.

  9. Examination of solar simulators used for the determination of sunscreen UVA efficacy.

    Science.gov (United States)

    Sayre, Robert M; Dowdy, John C

    2010-01-01

    The U.S. FDA recently proposed both in vivo and in vitro UVA efficacy tests for sunscreen products with the lower result used to establish the sunscreen's labeled UVA protection claim. The FDA stated their rationale for dual tests was concern that the in vivo test method overemphasizes UVA-2 (320-340 nm) photoprotection. We attribute FDA's observation to the relative lack, compared to sunlight, of UVA-1 (340-400 nm) radiation in the current JCIA UVA solar simulator specification, allowing the method to generate higher UVA protection factors than sunscreens will provide in sunlight. Our work is based upon comparisons of Air Mass 1.0 sunlight to variously filtered UVA solar simulators. Sources near the JCIA UVA-2/UVA limits (8-20%) had a goodness of fit to solar UVA of only 67-79%. We propose that instead of using ratios of UVA-2 to UVA the standard should be a goodness of fit to the UVA region of an Air Mass 1 solar reference spectrum. As the spectral distribution of solar UVA varies much less than UVB, sunlight of reasonable zenith angles of < or = 60 degrees will have similar spectral shapes and approximate risk spectrum. Goodness of fit to this spectrum will produce UVA protection values predictive to those actually achieved in sunlight of different zenith angles.

  10. Solar air-conditioning. Proceedings

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2009-07-01

    European countries (Ignasi Gurruchaga); (21) Optimisation potential of a large solar adsorption cooling plant (Antoine Dalibard); (22) Planning, commissioning and practical experience with first summer of operation of a cost effective solar air conditioning system for a Canteen at Munich Airport (Carsten Hindenburg); (23) Energy and economic performance of solar cooling systems (Ursula Eicker); (24) Solar-driven adsorption chiller controlled by hot and cooling water temperature (Jan Albers); (25) Comparative results of monitored solar assisted heating and cooling installations (Wolfram Sparber); (26) Heating and cooling with a small scale solar driven adsorption chiller combined with a borehole system - recent results (Tomas Nunez); (27) Solar heating and cooling - Town hall Gleisdorf (Alexander Thuer); (28) Solar dessicant cooling system operating in Palermo (Italy): Results and Validation of simulation models (Marco Beccali); (29) The application of a liquid-dessicant air conditioner to solar cooling (Andrew Lowenstein); (30) A compact solid adsorption chiller for solar air conditioning (Robert Critoph); (31) Development of a two-stage absorption chiller for solar-assisted cooling and heating (Manuel Riepl); (32) Ionic liquids - a promising solution for solar absorption chillers? (Annett Kuehn);(33) Parabolic trough design optimization for high temperature lift solar cooling applications (Marcello Aprile); (34) Tentative R and D program forgetting adsorbents effective for solar air conditioning (Yury Aristov); (35) An energy efficient solar driven two-stage rotary desiccant cooling system: Experiment and case study (Yanjun Dai); (36) Performance of a flat plate collector-regenerator that uses earth-to-air heat exchangers for regeneration of water-lithium chloride solution in a solar coolant plant (Roberto Bruno); (37) 350 KW of dual solar cooling for optimal flexibility and economic performance (Roel de Coninck); (38) Global performance of a solar absorption cooling

  11. On the nature of obstacles braking solar wind near Mars and Venera planets and on specific features of the interaction between solar wind and atmospheres of these planets

    International Nuclear Information System (INIS)

    Breus, T.K.; Gringauz, K.I.

    1980-01-01

    Discussed is the nature of obstacles braking solar wind near Mars and Venera according to the data of soviet measurements at ''Mars'' and ''Venera'' series automatic interplanetary stations. It is shown that alongside with essential similarity there exist differences among the zones of flow-around of Venera and Mars by solar wind. Such differences include, particularly, smaller dimensions of the obstacle of Venera as compared with Mars, and correspondingly less remote position of the shock wave front from the planet, different peculiarities of property changes of day-time ionosphere depending on the Sun zenith angle and other. The analysis of the experimental data permits to conclude that ionosphere and correspondingly the induced magnetic field of Venera play a determining role in the formation of the shock wave and the picture of planet flow-around by solar wind, while the determining role in the obstacle formation braking solar wind of Mars is played by the eigen planet field

  12. Influence of solar UVA on erythemal irradiances

    International Nuclear Information System (INIS)

    Parisi, A V; Turnbull, D J; Kimlin, M G

    2006-01-01

    Many materials in everyday use such as window glass in homes and offices, glass in sunrooms and greenhouses, vehicle glass and some brands of sunscreens act as a barrier to the shorter UVB wavelengths while transmitting some of the longer UVA wavelengths. This paper reports on the erythemal exposures due to the UVA waveband encountered over a 12-month period for a solar zenith angle (SZA) range of 4 0 to 80 0 and the resulting times required for an erythemal exposure of one standard erythemal dose (SED) due to the erythemal exposures to the UVA wavelengths. The minimum time for an exposure of one SED due to the UVA wavelengths in winter is approximately double that what it is in summer. The time period of 40 to 60 min was the most frequent length of time for an exposure of one SED with 60 to 80 min the next frequent length of time required for a one SED exposure

  13. The Solar Ultraviolet Environment at the Ocean.

    Science.gov (United States)

    Mobley, Curtis D; Diffey, Brian L

    2018-05-01

    Atmospheric and oceanic radiative transfer models were used to compute spectral radiances between 285 and 400 nm onto horizontal and vertical plane surfaces over water. The calculations kept track of the contributions by the sun's direct beam, by diffuse-sky radiance, by radiance reflected from the sea surface and by water-leaving radiance. Clear, hazy and cloudy sky conditions were simulated for a range of solar zenith angles, wind speeds and atmospheric ozone concentrations. The radiances were used to estimate erythemal exposures due to the sun and sky, as well as from radiation reflected by the sea surface and backscattered from the water column. Diffuse-sky irradiance is usually greater than direct-sun irradiance at wavelengths below 330 nm, and reflected and water-leaving irradiance accounts for 10 at depths down to two meters and >6 down to 5 m. © 2018 The American Society of Photobiology.

  14. 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.

  15. Large Customers (DR Sellers)

    Energy Technology Data Exchange (ETDEWEB)

    Kiliccot, Sila [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2011-10-25

    State of the large customers for demand response integration of solar and wind into electric grid; openADR; CAISO; DR as a pseudo generation; commercial and industrial DR strategies; California regulations

  16. Research on fabrication technology for thin film solar cells for practical use. Research on low-cost fabrication technology for large-area modules (CdS/CdTe solar cell modules); Usumaku taiyo denchi seizo gijutsu no jitsuyoka kenkyu. Daimenseki module no tei cost seizo gijutsu (CdTe taiyo denchi module seizo no gijutsu kaihatsu)

    Energy Technology Data Exchange (ETDEWEB)

    Tatsuta, M [New Energy and Industrial Technology Development Organization, Tokyo (Japan)

    1994-12-01

    This paper reports the study results on the fabrication technology of CdS/CdTe solar cell modules in fiscal 1994. (1) On the fabrication technology for high-efficiency large-area solar cells, high-quality CdTe active layer was studied. S content taken in the active layer at sintering of CdTe decreased with an increase in formed CdTe, resulting in improvement of Voc of cells. (2) On the window layer with wide band gap, the solar cell superior in collection efficiency and photoelectric characteristics could be obtained using the newly developed mixed crystal film of Cd(1-x)Zn(x)S. (3) On the forming technology of large-area coating/sintering films, improvement of CdS film quality was studied by pressurized processing of printed CdS films. As a result, improvement of film density and light transmissivity was confirmed. (4) On the leveling process technology of CdTe films, smooth surface films were obtained by experiment using an equipment simultaneously exciting samples in all directions as one of uniform coating methods of films. 7 figs.

  17. Large-Scale PV Module Manufacturing Using Ultra-Thin Polycrystalline Silicon Solar Cells: Final Subcontract Report, 1 April 2002--28 February 2006

    Energy Technology Data Exchange (ETDEWEB)

    Wohlgemuth, J.; Narayanan, M.

    2006-07-01

    The major objectives of this program were to continue advances of BP Solar polycrystalline silicon manufacturing technology. The Program included work in the following areas. (1) Efforts in the casting area to increase ingot size, improve ingot material quality, and improve handling of silicon feedstock as it is loaded into the casting stations. (2) Developing wire saws to slice 100-..mu..m-thick silicon wafers on 290-..mu..m-centers. (3) Developing equipment for demounting and subsequent handling of very thin silicon wafers. (4) Developing cell processes using 100-..mu..m-thick silicon wafers that produce encapsulated cells with efficiencies of at least 15.4% at an overall yield exceeding 95%. (5) Expanding existing in-line manufacturing data reporting systems to provide active process control. (6) Establishing a 50-MW (annual nominal capacity) green-field Mega-plant factory model template based on this new thin polycrystalline silicon technology. (7) Facilitating an increase in the silicon feedstock industry's production capacity for lower-cost solar-grade silicon feedstock..

  18. Large-Scale PV Module Manufacturing Using Ultra-Thin Polycrystalline Silicon Solar Cells: Annual Subcontract Report, 1 April 2002--30 September 2003 (Revised)

    Energy Technology Data Exchange (ETDEWEB)

    Wohlgemuth, J.; Shea, S. P.

    2004-04-01

    The goal of BP Solar's Crystalline PVMaT program is to improve the present polycrystalline silicon manufacturing facility to reduce cost, improve efficiency, and increase production capacity. Key components of the program are: increasing ingot size; improving ingot material quality; improving material handling; developing wire saws to slice 100 ..mu..m thick silicon wafers on 200 ..mu..m centers; developing equipment for demounting and subsequent handling of very thin silicon wafers; developing cell processes using 100 ..mu..m thick silicon wafers that produce encapsulated cells with efficiencies of at least 15.4% at an overall yield exceeding 95%; expanding existing in-line manufacturing data reporting systems to provide active process control; establishing a 50 MW (annual nominal capacity) green-field Mega plant factory model template based on this new thin polycrystalline silicon technology; and facilitating an increase in the silicon feedstock industry's production capacity for lower-cost solar-grade silicon feedstock.

  19. Hydrophilic Conjugated Polymers with Large Bandgaps and Deep-Lying HOMO Levels as an Efficient Cathode Interlayer in Inverted Polymer Solar Cells.

    Science.gov (United States)

    Kan, Yuanyuan; Zhu, Yongxiang; Liu, Zhulin; Zhang, Lianjie; Chen, Junwu; Cao, Yong

    2015-08-01

    Two hydrophilic conjugated polymers, PmP-NOH and PmP36F-NOH, with polar diethanol-amine on the side chains and main chain structures of poly(meta-phenylene) and poly(meta-phenylene-alt-3,6-fluorene), respectively, are successfully synthesized. The films of PmP-NOH and PmP36F-NOH show absorption edges at 340 and 343 nm, respectively. The calculated optical bandgaps of the two polymers are 3.65 and 3.62 eV, respectively, the largest ones so far reported for hydrophilic conjugated polymers. PmP-NOH and PmP36F-NOH also possess deep-lying highest occupied molecular orbital levels of -6.19 and -6.15 eV, respectively. Inserting PmP-NOH and PmP36F-NOH as a cathode interlayer in inverted polymer solar cells with a PTB7/PC71 BM blend as the active layer, high power conversion efficiencies of 8.58% and 8.33%, respectively, are achieved, demonstrating that the two hydrophilic polymers are excellent interlayers for efficient inverted polymer solar cells. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Large-Scale PV Module Manufacturing Using Ultra-Thin Polycrystalline Silicon Solar Cells: Annual Subcontract Report, 1 October 2003--30 September 2004

    Energy Technology Data Exchange (ETDEWEB)

    Wohlgemuth, J.; Narayanan, M.

    2005-03-01

    The major objectives of this program are to continue the advancement of BP Solar polycrystalline silicon manufacturing technology. The program includes work in the following areas: Efforts in the casting area to increase ingot size, improve ingot material quality, and improve handling of silicon feedstock as it is loaded into the casting stations; developing wire saws to slice 100- m-thick silicon wafers on 290- m centers; developing equipment for demounting and subsequent handling of very thin silicon wafers; developing cell processes using 100- m-thick silicon wafers that produce encapsulated cells with efficiencies of at least 15.4% at an overall yield exceeding 95%; expanding existing in-line manufacturing data reporting systems to provide active process control; establishing a 50-MW (annual nominal capacity) green-field Mega-plant factory model template based on this new thin polycrystalline silicon technology; facilitating an increase in the silicon feedstock industry's production capacity for lower-cost solar-grade silicon feedstock.

  1. Hybrids of Solar Sail, Solar Electric, and Solar Thermal Propulsion for Solar-System Exploration

    Science.gov (United States)

    Wilcox, Brian H.

    2012-01-01

    Solar sails have long been known to be an attractive method of propulsion in the inner solar system if the areal density of the overall spacecraft (S/C) could be reduced to approx.10 g/sq m. It has also long been recognized that the figure (precise shape) of useful solar sails needs to be reasonably good, so that the reflected light goes mostly in the desired direction. If one could make large reflective surfaces with reasonable figure at an areal density of approx.10 g/sq m, then several other attractive options emerge. One is to use such sails as solar concentrators for solar-electric propulsion. Current flight solar arrays have a specific output of approx. 100W/kg at 1 Astronomical Unit (AU) from the sun, and near-term advances promise to significantly increase this figure. A S/C with an areal density of 10 g/sq m could accelerate up to 29 km/s per year as a solar sail at 1 AU. Using the same sail as a concentrator at 30 AU, the same spacecraft could have up to approx. 45 W of electric power per kg of total S/C mass available for electric propulsion (EP). With an EP system that is 50% power-efficient, exhausting 10% of the initial S/C mass per year as propellant, the exhaust velocity is approx. 119 km/s and the acceleration is approx. 12 km/s per year. This hybrid thus opens attractive options for missions to the outer solar system, including sample-return missions. If solar-thermal propulsion were perfected, it would offer an attractive intermediate between solar sailing in the inner solar system and solar electric propulsion for the outer solar system. In the example above, both the solar sail and solar electric systems don't have a specific impulse that is near-optimal for the mission. Solar thermal propulsion, with an exhaust velocity of the order of 10 km/s, is better matched to many solar system exploration missions. This paper derives the basic relationships between these three propulsion options and gives examples of missions that might be enabled by

  2. Solar cities

    International Nuclear Information System (INIS)

    Roaf, S.; Fuentes, M.; Gupta, R.

    2005-01-01

    Over the last decade, climate change has moved from being the concern of few to a widely recognized threat to humanity itself and the natural environment. The 1990s were the warmest decade on record, and ever-increasing atmospheric levels of greenhouse gases such as carbon dioxide (CO/sub 2/), could, if left unchecked lead to serious consequences globally, including increased risks of droughts, floods and storms, disruption to agriculture, rising sea levels and the spread of disease. The contribution of anthropogenic emissions of carbon dioxide has been recognized as the principal cause of the atmospheric changes that drive these climate trends. Globally, buildings are the largest source of indirect carbon emissions. In 2000, the UK Royal Commission on Environmental Pollution estimated that in order to stabilise carbon emissions at levels, which avoid catastrophic alterations in the climate, we would have to reduce emissions from the built environment by at least 60% by 2050 and 80% by 2100 relative to 1997 levels. Studies of the Oxford Ecohouse have demonstrated that it is not difficult to reduce carbon emissions from houses by 60% or more through energy efficiency measures, but it is only possible to reach the 90% level of reductions required by using renewable energy technologies. Solar energy technologies have been the most successfully applied of all renewable to date largely because they are the only systems that can be incorporated easily into the urban fabric. In addition, the short fossil fuel horizons that are predicted (c. 40 years left for oil and 65 years for gas) will drive the markets for solar technologies. For these reasons, the cities of the future will be powered by solar energy, to a greater or lesser extent, depending on the city form and location. In recognition of the need to move rapidly towards a renewable energy future, a group of international cities, including Oxford, have started the Solar City Network. In this paper we outline the

  3. D-region electron density and effective recombination coefficients during twilight – experimental data and modelling during solar proton events

    Directory of Open Access Journals (Sweden)

    A. Osepian

    2009-10-01

    Full Text Available Accurate measurements of electron density in the lower D-region (below 70 km altitude are rarely made. This applies both with regard to measurements by ground-based facilities and by sounding rockets, and during both quiet conditions and conditions of energetic electron precipitation. Deep penetration into the atmosphere of high-energy solar proton fluxes (during solar proton events, SPE produces extra ionisation in the whole D-region, including the lower altitudes, which gives favourable conditions for accurate measurements using ground-based facilities. In this study we show that electron densities measured with two ground-based facilities at almost the same latitude but slightly different longitudes, provide a valuable tool for validation of model computations. The two techniques used are incoherent scatter of radio waves (by the EISCAT 224 MHz radar in Tromsø, Norway, 69.6° N, 19.3° E, and partial reflection of radio-waves (by the 2.8 MHz radar near Murmansk, Russia, 69.0° N, 35.7° E. Both radars give accurate electron density values during SPE, from heights 57–60 km and upward with the EISCAT radar and between 55–70 km with the partial reflection technique. Near noon, there is little difference in the solar zenith angle between the two locations and both methods give approximately the same values of electron density at the overlapping heights. During twilight, when the difference in solar zenith angles increases, electron density values diverge. When both radars are in night conditions (solar zenith angle >99° electron densities at the overlapping altitudes again become equal. We use the joint measurements to validate model computations of the ionospheric parameters f+, λ, αeff and their variations during solar proton events. These parameters are important characteristics of the lower ionosphere structure which cannot be determined by other methods.

  4. Solar Energy.

    Science.gov (United States)

    Eaton, William W.

    Presented is the utilization of solar radiation as an energy resource principally for the production of electricity. Included are discussions of solar thermal conversion, photovoltic conversion, wind energy, and energy from ocean temperature differences. Future solar energy plans, the role of solar energy in plant and fossil fuel production, and…

  5. Solar energy

    Science.gov (United States)

    Rapp, D.

    1981-01-01

    The book opens with a review of the patterns of energy use and resources in the United States, and an exploration of the potential of solar energy to supply some of this energy in the future. This is followed by background material on solar geometry, solar intensities, flat plate collectors, and economics. Detailed attention is then given to a variety of solar units and systems, including domestic hot water systems, space heating systems, solar-assisted heat pumps, intermediate temperature collectors, space heating/cooling systems, concentrating collectors for high temperatures, storage systems, and solar total energy systems. Finally, rights to solar access are discussed.

  6. Solar Combisystems

    DEFF Research Database (Denmark)

    Thür, Alexander

    2006-01-01

    This note first introduces what is a solar combisystem, the structure how a solar combisystem is build up and what are criteria’s to evaluate a solar combisystem concept. Further on the main components of a solar combisystem, the main characteristics and possible advantages and disadvantages...... compared to each other are described. It is not the goal of this note to explain the technical details how to design all components of a solar combisystem. This is done during other lectures of the solar course and in other basic courses as well. This note tries to explain how a solar combisystem...

  7. Solar Systems

    Science.gov (United States)

    1979-01-01

    The solar collectors shown are elements of domestic solar hot water systems produced by Solar One Ltd., Virginia Beach, Virginia. Design of these systems benefited from technical expertise provided Solar One by NASA's Langley Research Center. The company obtained a NASA technical support package describing the d e sign and operation of solar heating equipment in NASA's Tech House, a demonstration project in which aerospace and commercial building technology are combined in an energy- efficient home. Solar One received further assistance through personal contact with Langley solar experts. The company reports that the technical information provided by NASA influenced Solar One's panel design, its selection of a long-life panel coating which increases solar collection efficiency, and the method adopted for protecting solar collectors from freezing conditions.

  8. Lighting measurement station: measurements of natural lighting for characterization of sky and zenith illuminance; Estacao de medicao de iluminacao: medicao de niveis de iluminacao natural para caracterizacao de iluminancias de ceu e luminancia de zenite

    Energy Technology Data Exchange (ETDEWEB)

    Souza, Roberta Vieira Goncalves de [Minas Gerais Univ., Belo Horizonte, MG (Brazil). Escola de Arquitetura. Dept. de Tecnologia da Arquitetura e do Urbanismo]. E-mail: roberta@arq.ufmg.br; Pereira, Fernando Oscar Ruttkay [Santa Catarina Univ., Florianopolis, SC (Brazil). Dept. de Arquitetura. Lab. de Conforto Ambiental]. E-mail: feco@arq.ufsc.br

    2002-07-01

    This paper describes the assembly of a standard station for measuring the day lighting for evaluation of the natural light availability. The mounting and data obtention form will also be described from a standard IDMP day lighting station for measuring the data from measuring zenith, horizontal, and vertical illuminance of the sky and vertical irradiance for the cardinal points.

  9. Solar radiophysics

    International Nuclear Information System (INIS)

    McLean, D.J.; Labrum, N.R.

    1985-01-01

    This book treats all aspects of solar radioastronomy at metre wavelengths, particularly work carried out on the Australian radioheliograph at Culgoora, with which most of the authors have been associated in one way or another. After an introductory section on historical aspects, the solar atmosphere, solar flares, and coronal radio emission, the book deals with instrumentation, theory, and details of observations and interpretations of the various aspects of metrewave solar radioastronomy, including burst types, solar storms, and the quiet sun. (U.K.)

  10. Variations in Solar Parameters and Cosmic Rays with Solar Magnetic Polarity

    Energy Technology Data Exchange (ETDEWEB)

    Oh, S. [Department of Earth Science Education, Chonnam National University, Gwangju, 61186 (Korea, Republic of); Yi, Y., E-mail: suyeonoh@jnu.ac.kr [Department of Astronomy, Space Science and Geology, Chungnam National University, Daejeon, 34134 (Korea, Republic of)

    2017-05-01

    The sunspot number varies with the 11-year Schwabe cycle, and the solar magnetic polarity reverses every 11 years approximately at the solar maximum. Because of polarity reversal, the difference between odd and even solar cycles is seen in solar activity. In this study, we create the mean solar cycle expressed by phase using the monthly sunspot number for all solar cycles 1–23. We also generate the mean solar cycle for sunspot area, solar radio flux, and cosmic ray flux within the allowance of observational range. The mean solar cycle has one large peak at solar maximum for odd solar cycles and two small peaks for most even solar cycles. The odd and even solar cycles have the statistical difference in value and shape at a confidence level of at least 98%. For solar cycles 19–23, the second peak in the even solar cycle is larger than the first peak. This result is consistent with the frequent solar events during the declining phase after the solar maximum. The difference between odd and even solar cycles can be explained by a combined model of polarity reversal and solar rotation. In the positive/negative polarity, the polar magnetic field introduces angular momentum in the same/opposite direction as/to the solar rotation. Thus the addition/subtraction of angular momentum can increase/decrease the motion of plasma to support the formation of sunspots. Since the polarity reverses at the solar maximum, the opposite phenomenon occurs in the declining phase.

  11. Continuous Czochralski Growth. Silicon Sheet Growth Development of the Large Area Silicon Sheet Task of the Low Cost Silicon Solar Array Project

    Science.gov (United States)

    Merz, F.

    1979-01-01

    During the reporting period, a successful 100 kilogram run was performed. Six ingots of 13 cm diameter were grown, ranging in size from 15.5 kg to 17.7 kg. Melt replenishment methods included both poly rod and lump feed material. Samples from each ingot were prepared for solar cell fabrication and analyses, impurity analysis, and structural studies. The furnace was converted to the 14-inch hot zone and preliminary heat runs were performed. Two sucessful runs were demonstrated, by growing 25 kg ingots from 30 kg melts. Also, a 100 kg run was attempted, utilizing the 14 inch crucible hot zone, but was prematurely terminated due to excessive monoxide which accumulated on the viewports and a seed failure.

  12. Scalability and stability of very thin roll-to-roll processed large area indium-tin-oxide free polymer solar cell modules

    DEFF Research Database (Denmark)

    Angmo, Dechan; Gevorgyan, Suren; Larsen-Olsen, Thue Trofod

    2013-01-01

    Polymer solar cell modules were prepared directly on thin flexible barrier polyethylene terephthalate foil. The performance of the modules was found to be scalable from a single cell with an area of 6 cm2 to modules with a total area of up to 186 cm2. The substrate thickness was also explored...... employing P3HT:PCBM as the active material and were found to exhibit a total area efficiency of >1% (1000 W/m2; AM1.5G) with a typical active-area efficiency in the 1.5–1.6% for total module area of >110 cm2 due to high fill factors in excess of 50%. The modules were also found to have an active...

  13. Surface Net Solar Radiation Estimated from Satellite Measurements: Comparisons with Tower Observations

    Science.gov (United States)

    Li, Zhanqing; Leighton, H. G.; Cess, Robert D.

    1993-01-01

    A parameterization that relates the reflected solar flux at the top of the atmosphere to the net solar flux at the surface in terms of only the column water vapor amount and the solar zenith angle was tested against surface observations. Net surface fluxes deduced from coincidental collocated satellite-measured radiances and from measurements from towers in Boulder during summer and near Saskatoon in winter have mean differences of about 2 W/sq m, regardless of whether the sky is clear or cloudy. Furthermore, comparisons between the net fluxes deduced from the parameterization and from surface measurements showed equally good agreement when the data were partitioned into morning and afternoon observations. This is in contrast to results from an empirical clear-sky algorithm that is unable to account adequately for the effects of clouds and that shows, at Boulder, a distinct morning to afternoon variation, which is presumably due to the predominance of different cloud types throughout the day. It is also demonstrated that the parameterization may be applied to irradiances at the top of the atmosphere that have been temporally averaged by using the temporally averaged column water vapor amount and the temporally averaged cosine of the solar zenith angle. The good agreement between the results of the parameterization and surface measurements suggests that the algorithm is a useful tool for a variety of climate studies.

  14. Solar thermal power plants

    International Nuclear Information System (INIS)

    Schnatbaum, L.

    2009-01-01

    The solar thermal power plant technology, the opportunities it presents and the developments in the market are outlined. The focus is on the technology of parabolic trough power plants, a proven technology for solar power generation on a large scale. In a parabolic trough power plant, trough-shaped mirrors concentrate the solar irradiation onto a pipe in the focal line of the collector. The thermal energy thus generated is used for electricity generation in a steam turbine. Parabolic trough plants can be combined with thermal storage and fossil or biomass fired heat exchangers to generate electricity even when the sun is not shining. Solar Millennium AG in Erlangen has developed the first power plant of this kind in Europe. After two years of construction the plant started operation in Southern Spain in 2008. This one and its sister projects are important steps leading the way for the whole market. The paper also covers the technological challenges, the key components used and the research and development activities concerning this technology. Solar thermal power plants are ideal for covering peak and medium loads in power grids. In hybrid operation they can also cover base-load. The Solar Chimney power plant, another striking technology for the conversion of solar into electric energy, is described briefly. The paper concludes with a look at the future - the import of solar energy from the deserts of North Africa to central Europe. (author)

  15. Sunmotor Solar Shack 120

    International Nuclear Information System (INIS)

    Jensen, E.

    2009-01-01

    This article described a solar pump that was developed by Alberta-based Sunmotor International Ltd. The prototype Solar Shack 120 was recently deployed in central Alberta for a remediation project for Devon Canada. The portable solar pump unit is well suited for environmental remediation in the oilpatch where conventional electricity is not available. The solar panels automatically run the pump whenever there is enough sunlight and there is liquid in the sump. Devon Canada wanted a system that continues to pump during cloudy weather to avoid the accumulation of effluent in the sump. The Solar Shack 120 delivers 120 volts of alternating current (vac) power. Solar panels are used to charge a bank of large sealed batteries that supply direct power (DC) to an inverter, which converts it into AC. A thermostat control was added to shut off the pumps in cold weather to avoid battery discharging. The Solar Shack unit has possibilities in countries with unreliable electricity supplies. It could provide a backup power supply that automatically kicks in whenever the power grid goes down. Sunmotor International Ltd. can supply complete remote power systems for both AC and DC electrical requirements. The systems are designed for each application to ensure customer satisfaction. The company is currently building a unit that integrates solar power with a generator backup, thereby eliminating the annoying noise of a continually running generator. 1 fig

  16. Quantum dot solar cells

    CERN Document Server

    Wu, Jiang

    2013-01-01

    The third generation of solar cells includes those based on semiconductor quantum dots. This sophisticated technology applies nanotechnology and quantum mechanics theory to enhance the performance of ordinary solar cells. Although a practical application of quantum dot solar cells has yet to be achieved, a large number of theoretical calculations and experimental studies have confirmed the potential for meeting the requirement for ultra-high conversion efficiency. In this book, high-profile scientists have contributed tutorial chapters that outline the methods used in and the results of variou

  17. Smart solar tanks for small solar domestic hot water systems

    DEFF Research Database (Denmark)

    Furbo, Simon; Andersen, Elsa; Knudsen, Søren

    2005-01-01

    Investigation of small SDHW systems based on smart solar tanks are presented. The domestic water in a smart solar tank can be heated both by solar collectors and by means of an auxiliary energy supply system. The auxiliary energy supply system – in this study electric heating elements – heats up...... systems, based on differently designed smart solar tanks and a traditional SDHW system were investigated by means of laboratory experiments and theoretical calculations. The investigations showed that the yearly thermal performance of SDHW systems with smart solar tanks is 5-35% higher than the thermal...... performance of traditional SDHW systems. Estimates indicate that the performance/cost ratio can be improved by up to 25% by using a smart solar tank instead of a traditional tank when the backup energy system is electric heating elements. Further, smart solar tanks are suitable for unknown, variable, large...

  18. Continuous Czochralski growth: Silicon sheet growth development of the large area sheet task of the low cost silicon solar array project

    Science.gov (United States)

    Johnson, C. M.

    1980-12-01

    The growth of 100 kg of silicon single crystal material, ten cm in diameter or greater, and 150 kg of silicon single crystal material 15 cm or greater utilizing one common silicon container material (one crucible) is investigated. A crystal grower that is recharged with a new supply of polysilicon material while still under vacuum and at temperatures above the melting point of silicon is developed. It accepts large polysilicon charges up to 30 kg, grows large crystal ingots (to 15 cm diameter and 25 kg in weight), and holds polysilicon material for recharging (rod or lump) while, at the same time, growing crystal ingots. Special equipment is designed to recharge polysilicon rods, recharge polysilicon lumps, and handle and store large, hot silicon crystal ingots. Many continuous crystal growth runs were performed lasting as long as 109 hours and producing as many as ten crystal ingots, 15 cm with weights progressing to 27 kg.

  19. Solar energy

    International Nuclear Information System (INIS)

    Kruisheer, N.

    1992-01-01

    In five brief articles product information is given on solar energy applications with special attention to the Netherlands. After an introduction on solar energy availability in the Netherlands the developments in solar boiler techniques are dealt with. Solar water heaters have advantages for the environment, and government subsidies stimulate different uses of such water heaters. Also the developments of solar cells show good prospects, not only for developing countries, but also for the industrialized countries. In brief the developments in solar energy storage and the connection of solar equipment to the grid are discussed. Finally attention is paid to the applications of passive solar energy in the housing construction, the use of transparent thermal insulation and the developments of translucent materials. 18 figs., 18 ills

  20. Solar Imagery

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Collection includes a variety of solar photographic and illustrated datasets contributed by a number of national and private solar observatories located worldwide....

  1. Solar Features

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Collection includes a variety of solar feature datasets contributed by a number of national and private solar observatories located worldwide.

  2. Solar Indices

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Collection includes a variety of indices related to solar activity contributed by a number of national and private solar observatories located worldwide. This...

  3. Dedicated Tool for Irradiation and Electrical Measurement of Large Surface Samples on the Beamline of a 2.5 Mev Pelletron Electron Accelerator: Application to Solar Cells

    Directory of Open Access Journals (Sweden)

    Lefèvre Jérémie

    2017-01-01

    After a brief description of the SIRIUS irradiation facility hosted at Laboratoire des Solides Irradiés (LSI, this paper gives detailed information about the Large Surface Irradiated-Cell (LSIC device. Preliminary results obtained during the ongoing qualification phase of the setup are also discussed.

  4. Packaging a successful NASA mission to reach a large audience within a small budget. Earth's Dynamic Space: Solar-Terrestrial Physics & NASA's Polar Mission

    Science.gov (United States)

    Fox, N. J.; Goldberg, R.; Barnes, R. J.; Sigwarth, J. B.; Beisser, K. B.; Moore, T. E.; Hoffman, R. A.; Russell, C. T.; Scudder, J.; Spann, J. F.; Newell, P. T.; Hobson, L. J.; Gribben, S. P.; Obrien, J. E.; Menietti, J. D.; Germany, G. G.; Mobilia, J.; Schulz, M.

    2004-12-01

    To showcase the on-going and wide-ranging scope of the Polar science discoveries, the Polar science team has created a one-stop shop for a thorough introduction to geospace physics, in the form of a DVD with supporting website. The DVD, Earth's Dynamic Space: Solar-Terrestrial Physics & NASA's Polar Mission, can be viewed as an end-to-end product or split into individual segments and tailored to lesson plans. Capitalizing on the Polar mission and its amazing science return, the Polar team created an exciting multi-use DVD intended for audiences ranging from a traditional classroom and after school clubs, to museums and science centers. The DVD tackles subjects such as the aurora, the magnetosphere and space weather, whilst highlighting the science discoveries of the Polar mission. This platform introduces the learner to key team members as well as the science principles. Dramatic visualizations are used to illustrate the complex principles that describe Earth’s dynamic space. In order to produce such a wide-ranging product on a shoe-string budget, the team poured through existing NASA resources to package them into the Polar story, and visualizations were created using Polar data to complement the NASA stock footage. Scientists donated their time to create and review scripts in order to make this a real team effort, working closely with the award winning audio-visual group at JHU/Applied Physics Laboratory. The team was excited to be invited to join NASA’s Sun-Earth Day 2005 E/PO program and the DVD will be distributed as part of the supporting educational packages.

  5. Solar Special

    International Nuclear Information System (INIS)

    Van Roekel, A.; Osborne, J.; Schroeter, S.; De Jong, R.; De Saint Jacob, Y.

    2009-01-01

    Solar power is growing much faster than most policymakers and analysts realise. As costs come down and feed-in tariffs go up across Europe, a number of countries have started in pursuit of market leader Germany. But in Germany criticism is growing of the multi-billion-euro support schemes that keep the solar industry booming. In this section of the magazine several articles are dedicated to developments in solar energy in Europe. The first article is an overview story on the strong growing global market for solar cells, mainly thanks to subsidy schemes. The second article is on the position of foreign companies in the solar market in Italy. Article number three is dedicated to the conditions for solar technology companies to establish themselves in the German state of Saxony. Also the fifth article deals with the development of solar cells in Saxony: scientists, plant manufacturers and module producers in Saxony are working on new technologies that can be used to produce solar electricity cost-effectively. The goal is to bring the price down to match that of conventionally generated electricity within the next few years. The sixth article deals with the the solar power market in Belgium, which may be overheated or 'oversubsidized'. Article seven is on France, which used to be a pioneer in solar technology, but now produces only a fraction of the solar output of market leader Germany. However, new attractive feed-in-tariffs are changing the solar landscape drastically

  6. OMI satellite observed formaldehyde column from 2006 to 2015 over Xishuangbanna, southwest China, and validation using ground based zenith-sky DOAS.

    Science.gov (United States)

    Liu, Rui; Feng, Tao; Wang, Shanshan; Shi, Chanzhen; Guo, Yanlin; Nan, Jialiang; Deng, Yun; Zhou, Bin

    2018-02-01

    Formaldehyde (HCHO) provides a proxy to reveal the isoprene and biogenic volatile organic compounds emission which plays important roles in atmospheric chemical process and climate change. The ground-based observation with zenith-sky DOAS is carried out in order to validate the HCHO columns from OMI. It has a good correlation of 0.71678 between the HCHO columns from two sources. Then we use the OMI HCHO columns from January 2006 to December 2015 to indicate the interannual variation and spatial distribution in Xishuangbanna. The HCHO concentration peaks appeared in March or April for each year significantly corresponding to the intensive fire counts at the same time, which illustrate that the high HCHO columns are strongly influenced by the biomass burning in spring. Temperature and precipitation are also the important influence factors in the seasonal variation when there is nearly no biomass burning. The spatial patterns over the past ten years strengthen the deduction from the temporal variation and show the relationship with land cover and land use, elevation and population density. It is concluded that the biogenic activity plays a role in controlling the background level of HCHO in Xishuangbanna, while biomass burning is the main driving force of high HCHO concentration. And forests are greater contributor to HCHO rather than rubber trees which cover over 20% of the land in the region. Moreover, uncertainties from HCHO slant column retrieval and AMFs calculation are discussed in detail. Copyright © 2017. Published by Elsevier B.V.

  7. First Zenith Total Delay and Integrated Water Vapour Estimates from the Near Real-Time GNSS Data Processing Systems at the University of Luxembourg

    Science.gov (United States)

    Ahmed, F.; Teferle, F. N.; Bingley, R. M.

    2012-04-01

    Since September 2011 the University of Luxembourg in collaboration with the University of Nottingham has been setting up two near real-time processing systems for ground-based GNSS data for the provision of zenith total delay (ZTD) and integrated water vapour (IWV) estimates. Both systems are based on Bernese v5.0, use the double-differenced network processing strategy and operate with a 1-hour (NRT1h) and 15-minutes (NRT15m) update cycle. Furthermore, the systems follow the approach of the E-GVAP METO and IES2 systems in that the normal equations for the latest data are combined with those from the previous four updates during the estimation of the ZTDs. NRT1h currently takes the hourly data from over 130 GNSS stations in Europe whereas NRT15m is primarily using the real-time streams of EUREF-IP. Both networks include additional GNSS stations in Luxembourg, Belgium and France. The a priori station coordinates for all of these stem from a moving average computed over the last 20 to 50 days and are based on the precise point positioning processing strategy. In this study we present the first ZTD and IWV estimates obtained from the NRT1h and NRT15m systems in development at the University of Luxembourg. In a preliminary evaluation we compare their performance to the IES2 system at the University of Nottingham and find the IWV estimates to agree at the sub-millimetre level.

  8. Solar tomography adaptive optics.

    Science.gov (United States)

    Ren, Deqing; Zhu, Yongtian; Zhang, Xi; Dou, Jiangpei; Zhao, Gang

    2014-03-10

    Conventional solar adaptive optics uses one deformable mirror (DM) and one guide star for wave-front sensing, which seriously limits high-resolution imaging over a large field of view (FOV). Recent progress toward multiconjugate adaptive optics indicates that atmosphere turbulence induced wave-front distortion at different altitudes can be reconstructed by using multiple guide stars. To maximize the performance over a large FOV, we propose a solar tomography adaptive optics (TAO) system that uses tomographic wave-front information and uses one DM. We show that by fully taking advantage of the knowledge of three-dimensional wave-front distribution, a classical solar adaptive optics with one DM can provide an extra performance gain for high-resolution imaging over a large FOV in the near infrared. The TAO will allow existing one-deformable-mirror solar adaptive optics to deliver better performance over a large FOV for high-resolution magnetic field investigation, where solar activities occur in a two-dimensional field up to 60'', and where the near infrared is superior to the visible in terms of magnetic field sensitivity.

  9. Solar Indices - Solar Radio Flux

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Collection includes a variety of indices related to solar activity contributed by a number of national and private solar observatories located worldwide. This...

  10. Effect of carboxyl anchoring groups in asymmetric zinc phthalocyanine with large steric hindrance on the dye-sensitized solar cell performance

    Energy Technology Data Exchange (ETDEWEB)

    Shi, Wenye; Peng, Bosi; Lin, Li; Li, Renjie; Zhang, Jing, E-mail: jzhang03@whu.edu.cn; Peng, Tianyou, E-mail: typeng@whu.edu.cn

    2015-08-01

    Asymmetric zinc phthalocyanines containing tribenzonaphtho-condensed porphyrazine with six bulky diphenylphenoxy and one or two carboxyl groups are used as sensitizers for dye-sensitized solar cells (DSSCs). It is found that Zn-tri-PcNc-4 having two carboxyl groups shows a slight redshift in the Q-band absorption but a significantly decreased absorbance as compared with Zn-tri-PcNc-8 having one carboxyl group, and Zn-tri-PcNc-4 can be more stably and perpendicularly grafted onto the TiO{sub 2} surface than Zn-tri-PcNc-8, which further leads to the differences in the interfacial charge transfer dynamics and dye-loaded amount. Zn-tri-PcNc-4 with two carboxyl groups grafted onto the TiO{sub 2} electrode surface of DSSC results in a photovoltaic conversion efficiency of 3.22%, higher than that (3.01%) of the analog with one carboxyl group (Zn-tri-PcNc-8), which exhibits a lower short-circuit current but much higher open-circuit voltage. The additional carboxyl group in Zn-tri-PcNc-4 leads to the enhanced dye-loaded amount and the molecular orbital energy level shift toward positive direction, causing more efficient electron injection and higher short-circuit current than Zn-tri-PcNc-8; while the two carboxyl groups of Zn-tri-PcNc-4 would cause more protonation of TiO{sub 2} surface, which possibly leads to the downward shift of TiO{sub 2} conduction band edge, and then to the decreased open-circuit voltage. The present results demonstrate the molecular engineering aspect of ZnPc dyes in which the fine tuning of the energy levels and molecular structures is crucial for high conversion efficiency of DSSCs. - Highlights: • ZnPcs with six diphenylphenoxy and one/two carboxyl groups are used as dyes for DSSCs. • Effect of carboxyl group number on the ZnPc-sensitized cell property are scrutinized. • Grafting two carboxyl groups on ZnPc leads to the enhanced photocurrent and efficiency. • ZnPc with one COOH has a higher open-circuit voltage than its analog with two

  11. The effect of finite geometry on the three-dimensional transfer of solar irradiance in clouds

    Science.gov (United States)

    Davies, R.

    1978-01-01

    Results are presented for a Monte Carlo model applied to a wide range of cloud widths and heights, and for an analytical model restricted in its application to cuboidally shaped clouds whose length, breadth, and depth may be varied independently; the clouds must be internally homogeneous with respect to their intrinsic radiative properties. Comparative results from the Monte Carlo method and the derived analytical model are presented for a wide range of cloud sizes, with special emphasis on the effects of varying the single scatter albedo, the solar zenith angle, and the scattering phase angle.

  12. Coupled solar still, solar heater

    Energy Technology Data Exchange (ETDEWEB)

    Davison, R R; Harris, W B; Moor, D H; Delyannis, A; Delyannis, E [eds.

    1976-01-01

    Computer simulation of combinations of solar stills and solar heaters indicates the probable economic advantage of such an arrangement in many locations if the size of the heater is optimized relative to that of the still. Experience with various low cost solar heaters is discussed.

  13. Solar Sailing

    Science.gov (United States)

    Johnson, Les

    2009-01-01

    Solar sailing is a topic of growing technical and popular interest. Solar sail propulsion will make space exploration more affordable and offer access to destinations within (and beyond) the solar system that are currently beyond our technical reach. The lecture will describe solar sails, how they work, and what they will be used for in the exploration of space. It will include a discussion of current plans for solar sails and how advanced technology, such as nanotechnology, might enhance their performance. Much has been accomplished recently to make solar sail technology very close to becoming an engineering reality and it will soon be used by the world s space agencies in the exploration of the solar system and beyond. The first part of the lecture will summarize state-of-the-art space propulsion systems and technologies. Though these other technologies are the key to any deep space exploration by humans, robots, or both, solar-sail propulsion will make space exploration more affordable and offer access to distant and difficult destinations. The second part of the lecture will describe the fundamentals of space solar sail propulsion and will describe the near-, mid- and far-term missions that might use solar sails as a propulsion system. The third part of the lecture will describe solar sail technology and the construction of current and future sailcraft, including the work of both government and private space organizations.

  14. EDITORIAL Solar harvest Solar harvest

    Science.gov (United States)

    Demming, Anna

    2010-12-01

    The first observations of the photoelectric effect date back to the early 19th century from work by Alexandre Edmond Becquerel, Heinrich Hertz, Wilhelm Hallwachs and J J Thomson. The theory behind the phenomena was clarified in a seminal paper by Einstein in 1905 and became an archetypical feature of the wave-particle description of light. A different manifestation of quantised electron excitation, whereby electrons are not emitted but excited into the valence band of the material, is what we call the photoconductive effect. As well as providing an extension to theories in fundamental physics, the phenomenon has spawned a field with enormous ramifications in the energy industry through the development of solar cells. Among advances in photovoltaic technology has been the development of organic photovoltaic technology. These devices have many benefits over their inorganic counterparts, such as light-weight, flexible material properties, as well as versatile materials' synthesis and low-cost large-scale production—all highly advantageous for manufacturing. The first organic photovoltaic systems were reported over 50 years ago [1], but the potential of the field has escalated in recent years in terms of efficiency, largely through band offsetting. Since then, great progress has been made in studies for optimising the efficiency of organic solar cells, such as the work by researchers in Germany and the Netherlands, where investigations were made into the percentage composition and annealing effects on composites of poly(3-hexylthiophene) (P3HT) and the fullerene derivative [6,6]-phenyl-C61 butyric acid methyl ester (PCBM) [2]. Hybrid devices that aim to exploit the advantages of both inorganic and organic constituents have also proven promising. One example of this is the work reported by researchers in Tunisia and France on a systematic study for optimising the composition morphology of TiO2 nanoparticles in poly(N-vinylcarbazole) (PVK), which also led to insights

  15. Auroral zone E-region conductivities during solar minimum derived from EISCAT data

    International Nuclear Information System (INIS)

    Schlegel, K.

    1988-01-01

    From two years of EISCAT data (1985-1986, a period of low solar activity) 8337 E-region conductivity profiles have been calculated as 5-min averages. From these profiles the height of the conductivity maxima for the Hall and Pedersen conductivities (H max ), the height-integrated Hall and Pedersen conductivities and the ratio of both have been computed. Histograms as well as average values of these quantities are displayed as a function of K p and of magnetic local time. The former results showed quantitatively the increase of the conductivities and the decrease of H max with increasing magnetic activity. The latter results revealed that on the average the conductivities are maximal in the early morning hours due to hard particle precipitation, H max being affected both by the solar zenith angle and by particle precipitation. The solar zenith angle dependence of the conductivities is only significant for low K p -values. Latitudinal profiles of the height-integrated conductivities show quantitatively the southward shift of the average conductivity maximum with increasing magnetic activity

  16. The Impact of Indoor and Outdoor Radiometer Calibration on Solar Measurements

    Energy Technology Data Exchange (ETDEWEB)

    Habte, Aron; Sengupta, Manajit; Andreas, Afshin; Reda, Ibrahim; Robinson, Justin

    2016-06-02

    This study addresses the effect of calibration methodologies on calibration responsivities and the resulting impact on radiometric measurements. The calibration responsivities used in this study are provided by NREL's broadband outdoor radiometer calibration (BORCAL) and a few prominent manufacturers. The BORCAL method provides outdoor calibration responsivity of pyranometers and pyrheliometers at a 45 degree solar zenith angle and responsivity as a function of solar zenith angle determined by clear-sky comparisons to reference irradiance. The BORCAL method also employs a thermal offset correction to the calibration responsivity of single-black thermopile detectors used in pyranometers. Indoor calibrations of radiometers by their manufacturers are performed using a stable artificial light source in a side-by-side comparison of the test radiometer under calibration to a reference radiometer of the same type. These different methods of calibration demonstrated 1percent to 2 percent differences in solar irradiance measurement. Analyzing these values will ultimately enable a reduction in radiometric measurement uncertainties and assist in developing consensus on a standard for calibration.

  17. Solar Energy Perspectives In Egypt

    International Nuclear Information System (INIS)

    Comsan, M.N.H.

    2010-01-01

    Egypt belongs to the global sun-belt. The country is in advantageous position with solar energy. In 1991 solar atlas for Egypt was issued indicating that the country enjoys 2900-3200 hours of sunshine annually with annual direct normal energy density 1970-3200 kWh/m2 and technical solar-thermal electricity generating potential of 73.6 Peta watt hour (PWh). Egypt was among the first countries to utilize solar energy. In 1910, a practical industrial scale solar system engine was built at Maadi south to Cairo using solar thermal parabolic collectors. The engine was used to produce steam which drove a series of large water pumps for irrigation. Nowadays utilization of solar energy includes use of photovoltaic cells, solar water heating and solar thermal power. Use of solar thermal technology may include both electricity generation and water desalination, which is advantageous for Egypt taking in consideration its shortage in water supply. The article discusses perspectives of solar energy in Egypt and developmental trends till 2050

  18. Dye solar cells: a different approach to solar energy

    CSIR Research Space (South Africa)

    Le Roux, Lukas J

    2008-11-01

    Full Text Available An attractive and cheaper alternative to siliconbased photovoltaic (PV) cells for the conversion of solar light into electrical energy is to utilise dyeadsorbed, large-band-gap metal oxide materials such as TiO2 to absorb the solar light...

  19. Solar and Hydrogen

    International Nuclear Information System (INIS)

    Kadirgan, F.; Beyhan, S.; Oezenler, S.

    2006-01-01

    It has been widely accepted that the only sustainable and environmentally friendly energy is the solar energy and hydrogen energy, which can meet the increasing energy demand in the future. Solar Energy may be used either for solar thermal or for solar electricity conversion. Solar thermal collectors represent a wide-spread type of system for the conversion of solar energy. Radiation, convection and conduction are strongly coupled energy transport mechanisms in solar collector systems. The economic viability of lower temperature applications of solar energy may be improved by increasing the quantity of usable energy delivered per unit area of collector. This can be achieved by the use of selective black coatings which have a high degree of solar absorption, maintaining high energy input to the solar system while simultaneously suppressing the emission of thermal infrared radiation. Photovoltaic solar cells and modules are produced for: (1) large scale power generation, most commonly when modules are incorporated as part of a building (building integrated photovoltaic s) but also in centralised power stations, (2) supplying power to villages and towns in developing countries that are not connected to the supply grid, e.g. for lighting and water pumping systems, (3) supplying power in remote locations, e.g. for communications or weather monitoring equipment, (4) supplying power for satellites and space vehicles, (5) supplying power for consumer products, e.g. calculators, clocks, toys and night lights. In hydrogen energy systems, Proton exchange membrane (PEMFC) fuel cells are promising candidates for applications ranging from portable power sources (battery replacement applications) to power sources for future electric vehicles because of their safety, elimination of fuel processor system, thus, simple device fabrication and low cost. Although major steps forward have been achieved in terms of PEMFC design since the onset of research in this area, further

  20. Quantitative relationship between VLF phase deviations and 1-8 A solar X-ray fluxes during solar flares

    Energy Technology Data Exchange (ETDEWEB)

    Muraoka, Y; Murata, H; Sato, T [Hyogo Coll. Of Medicine (Japan). Dept. of Physics

    1977-07-01

    An attempt is made to investigate the quantitative relationship between VLF phase deviations in SPA (sudden phase anomalies) events and associated solar X-ray fluxes in the 1 to 8 A band during solar flares. The phase deviations (..delta..phi) of the 18.6 kHz VLF wave transmitted from NLK, USA are used in this analysis which were recorded at Nishinomiya, Japan during the period June 1974 to May 1975. The solar X-ray fluxes (F/sub 0/) in the 1 to 8 A band are estimated from fsub(min) variations using the empirical expression given by Sato (J.Geomag.Geoelectr.;27: 95(1975)), because no observed data were available on the 1 to 8 a X-ray fluxes during the period of the VLF observation. The result shows that the normalized phase variation, ..delta..phi/coschisub(min), where chisub(min) represents the minimum solar zenith angle on the VLF propagation path, increases with increasing logF/sub 0/. A theoretical explanation for this is presented assuming that enhanced ionizations produced in the lower ionosphere by a monochromatic solar X-ray emission are responsible for the VLF phase deviations. Also it is found that a threshold X-ray flux to produce a detectable SPA effect is approximately 1.5 x 10/sup -3/ cm/sup -2/ sec/sup -1/ in the 1 to 8 a band.

  1. Development of process technology for large-area thin-film solar modules based on compound semiconductors. Final report; Entwicklung der technologischen Grundlagen fuer grosse Photovoltaikmodule auf Basis von Duennschicht-Verbindungshalbleitern. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Maurus, H.; Lechner, P.; Geyer, R.; Ruebel, H.; Schade, H.; Psyk, W.; Frammelsberger, W.; Berthold, W.; Eichner, C.; Heckel, E.; Huber, R.; Labudde-Eibl, H.; Raith, S.; Schenk, B.; Ullrich, H.

    1998-06-01

    A cooperative effort of the Center for Solar Energy and Hydrogen Research (ZSW) and Phototronics Solartechnik GmbH (PST) aimed at the transfer of highly efficient solar cells developed on a laboratory scale, to large-area thin-film solar modules suitable for production. This work was based on research and development at the Institute for Physical Electronics (IPE) of Stuttgart University and ZSW on one hand, and on the know-how of PST in regard to large-area module fabrication on the other hand. The various thin-film layers of the cells and modules comprize molybdenum as rear contact, copper-indium(gallium)-diselenide (CIGS) as absorber material, the combination of cadmium sulphide (CdS) and ZnO as window layer. To produce these layers on large areas (30x30 cm{sup 2}), equipment was constructed and procedures were developed. Monolithic series connection of cells, used in other thin-film technologies, was studied and optimized by suitable patterning procedures, such as laser-scribing, mechanical scribing or lift-off techniques. Central to the PST efforts was the large-area deposition of Mo followed by patterning for the monolithic series connection, and furthermore important contributions in regard to the ZnO window layer as well as aspects of the module technology. The latter include film removal along the module edges, contacting and cable attachment, lamination, module measurements and temperature/humidity tests. The main goal, namely the basic development of equipment and procedures to fabricate large-area (30x30 cm{sup 2}) modules with an efficiency of 10-12%, was reached (best module with 11.7% efficiency referenced to the aperature area). (orig.) [Deutsch] Um die im Labormassstab entwickelten hocheffizienten Solarzellen in industriell relevante grossflaechige Duennschichtmodule umzusetzen, arbeiteten das Zentrum fuer Sonnenenergie- und Wasserstoff-Forschung (ZSW) Baden-Wuerttemberg und die Phototronics Solartechnik GmbH (PST) zusammen. Ausgangsbasis waren

  2. Dependence of Lunar Surface Charging on Solar Wind Plasma Conditions and Solar Irradiation

    Science.gov (United States)

    Stubbs, T. J.; Farrell, W. M.; Halekas, J. S.; Burchill, J. K.; Collier, M. R.; Zimmerman, M. I.; Vondrak, R. R.; Delory, G. T.; Pfaff, R. F.

    2014-01-01

    The surface of the Moon is electrically charged by exposure to solar radiation on its dayside, as well as by the continuous flux of charged particles from the various plasma environments that surround it. An electric potential develops between the lunar surface and ambient plasma, which manifests itself in a near-surface plasma sheath with a scale height of order the Debye length. This study investigates surface charging on the lunar dayside and near-terminator regions in the solar wind, for which the dominant current sources are usually from the pohotoemission of electrons, J(sub p), and the collection of plasma electrons J(sub e) and ions J(sub i). These currents are dependent on the following six parameters: plasma concentration n(sub 0), electron temperature T(sub e), ion temperature T(sub i), bulk flow velocity V, photoemission current at normal incidence J(sub P0), and photo electron temperature T(sub p). Using a numerical model, derived from a set of eleven basic assumptions, the influence of these six parameters on surface charging - characterized by the equilibrium surface potential, Debye length, and surface electric field - is investigated as a function of solar zenith angle. Overall, T(sub e) is the most important parameter, especially near the terminator, while J(sub P0) and T(sub p) dominate over most of the dayside.

  3. Solar opacities constrained by solar neutrinos and solar oscillations

    International Nuclear Information System (INIS)

    Cox, A.N.

    1989-01-01

    This review discusses the current situation for opacities at the solar center, the solar surface, and for the few million kelvin temperatures that occur below the convection zone. The solar center conditions are important because they are crucial for the neutrino production, which continues to be predicted about 4 times that observed. The main extinction effects there are free-free photon absorption in the electric fields of the hydrogen, helium and the CNO atoms, free electron scattering of photons, and the bound-free and bound-bound absorption of photons by iron atoms with two electrons in the 1s bound level. An assumption that the iron is condensed-out below the convection zone, and the opacity in the central regions is thereby reduced, results in about a 25 percent reduction in the central opacity but only a 5 percent reduction at the base of the convection zone. Furthermore, the p-mode solar oscillations are changed with this assumption, and do not fit the observed ones as well as for standard models. A discussion of the large effective opacity reduction by weakly interacting massive particles also results in poor agreement with observed p-mode oscillation frequencies. The much larger opacities for the solar surface layers from the Los Alamos Astrophysical Opacity Library instead of the widely used Cox and Tabor values show small improvements in oscillation frequency predictions, but the largest effect is in the discussion of p-mode stability. Solar oscillation frequencies can serve as an opacity experiment for the temperatures and densities, respectively, of a few million kelvin and between 0.1 and 10 g/cm 3 . Current oscillation frequency calculations indicate that possibly the Opacity Library values need an increase of typically 15 percent just at the bottom of the convection zone at 3 x 10 6 K. 41 refs., 15 figs., 1 tab

  4. Phenomena induced by powerful HF pumping towards magnetic zenith with a frequency near the F-region critical frequency and the third electron gyro harmonic frequency

    Directory of Open Access Journals (Sweden)

    N. F. Blagoveshchenskaya

    2009-01-01

    Full Text Available Multi-instrument observational data from an experiment on 13 October 2006 at the EISCAT/HEATING facility at Tromsø, Norway are analysed. The experiment was carried out in the evening hours when the electron density in the F-region dropped, and the HF pump frequency fH was near and then above the critical frequency of the F2 layer. The distinctive feature of this experiment is that the pump frequency was just below the third electron gyro harmonic frequency, while both the HF pump beam and UHF radar beam were directed towards the magnetic zenith (MZ. The HF pump-induced phenomena were diagnosed with several instruments: the bi-static HF radio scatter on the London-Tromsø-St. Petersburg path, the CUTLASS radar in Hankasalmi (Finland, the European Incoherent Scatter (EISCAT UHF radar at Tromsø and the Tromsø ionosonde (dynasonde. The results show thermal electron excitation of the HF-induced striations seen simultaneously from HF bi-static scatter and CUTLASS radar observations, accompanied by increases of electron temperature when the heater frequency was near and then above the critical frequency of the F2 layer by up to 0.4 MHz. An increase of the electron density up to 25% accompanied by strong HF-induced electron heating was observed, only when the heater frequency was near the critical frequency and just below the third electron gyro harmonic frequency. It is concluded that the combined effect of upper hybrid resonance and gyro resonance at the same altitude gives rise to strong electron heating, the excitation of striations, HF ray trapping and extension of HF waves to altitudes where they can excite Langmuir turbulence and fluxes of electrons accelerated to energies that produce ionization.

  5. Phenomena induced by powerful HF pumping towards magnetic zenith with a frequency near the F-region critical frequency and the third electron gyro harmonic frequency

    Directory of Open Access Journals (Sweden)

    N. F. Blagoveshchenskaya

    2009-01-01

    Full Text Available Multi-instrument observational data from an experiment on 13 October 2006 at the EISCAT/HEATING facility at Tromsø, Norway are analysed. The experiment was carried out in the evening hours when the electron density in the F-region dropped, and the HF pump frequency fH was near and then above the critical frequency of the F2 layer. The distinctive feature of this experiment is that the pump frequency was just below the third electron gyro harmonic frequency, while both the HF pump beam and UHF radar beam were directed towards the magnetic zenith (MZ. The HF pump-induced phenomena were diagnosed with several instruments: the bi-static HF radio scatter on the London-Tromsø-St. Petersburg path, the CUTLASS radar in Hankasalmi (Finland, the European Incoherent Scatter (EISCAT UHF radar at Tromsø and the Tromsø ionosonde (dynasonde. The results show thermal electron excitation of the HF-induced striations seen simultaneously from HF bi-static scatter and CUTLASS radar observations, accompanied by increases of electron temperature when the heater frequency was near and then above the critical frequency of the F2 layer by up to 0.4 MHz. An increase of the electron density up to 25% accompanied by strong HF-induced electron heating was observed, only when the heater frequency was near the critical frequency and just below the third electron gyro harmonic frequency. It is concluded that the combined effect of upper hybrid resonance and gyro resonance at the same altitude gives rise to strong electron heating, the excitation of striations, HF ray trapping and extension of HF waves to altitudes where they can excite Langmuir turbulence and fluxes of electrons accelerated to energies that produce ionization.

  6. Cloud Droplet Size and Liquid Water Path Retrievals From Zenith Radiance Measurements: Examples From the Atmospheric Radiation Measurement Program and the Aerosol Robotic Network

    Science.gov (United States)

    Chiu, J. C.; Marshak, A.; Huang, C.-H.; Varnai, T.; Hogan, R. J.; Giles, D. M.; Holben, B. N.; Knyazikhin, Y.; O'Connor, E. J.; Wiscombe, W. J.

    2012-01-01

    The ground-based Atmospheric Radiation Measurement Program (ARM) and NASA Aerosol Robotic Network (AERONET) routinely monitor clouds using zenith radiances at visible and near-infrared wavelengths. Using the transmittance calculated from such measurements, we have developed a new retrieval method for cloud effective droplet size and conducted extensive tests for non-precipitating liquid water clouds. The underlying principle is to combine a water-absorbing wavelength (i.e. 1640 nm) with a nonwater-absorbing wavelength for acquiring information on cloud droplet size and optical depth. For simulated stratocumulus clouds with liquid water path less than 300 g/sq m and horizontal resolution of 201m, the retrieval method underestimates the mean effective radius by 0.8 m, with a root-mean-squared error of 1.7 m and a relative deviation of 13 %. For actual observations with a liquid water path less than 450 gm.2 at the ARM Oklahoma site during 2007-2008, our 1.5 min-averaged retrievals are generally larger by around 1 m than those from combined ground-based cloud radar and microwave radiometer at a 5min temporal resolution. We also compared our retrievals to those from combined shortwave flux and microwave observations for relatively homogeneous clouds, showing that the bias between these two retrieval sets is negligible, but the error of 2.6 m and the relative deviation of 22% are larger than those found in our simulation case. Finally, the transmittance-based cloud effective droplet radii agree to better than 11% with satellite observations and have a negative bias of 1 m. Overall, the retrieval method provides reasonable cloud effective radius estimates, which can enhance the cloud products of both ARM and AERONET.

  7. The Global Solar Dynamo

    Science.gov (United States)

    Cameron, R. H.; Dikpati, M.; Brandenburg, A.

    2017-09-01

    A brief summary of the various observations and constraints that underlie solar dynamo research are presented. The arguments that indicate that the solar dynamo is an alpha-omega dynamo of the Babcock-Leighton type are then shortly reviewed. The main open questions that remain are concerned with the subsurface dynamics, including why sunspots emerge at preferred latitudes as seen in the familiar butterfly wings, why the cycle is about 11 years long, and why the sunspot groups emerge tilted with respect to the equator (Joy's law). Next, we turn to magnetic helicity, whose conservation property has been identified with the decline of large-scale magnetic fields found in direct numerical simulations at large magnetic Reynolds numbers. However, magnetic helicity fluxes through the solar surface can alleviate this problem and connect theory with observations, as will be discussed.

  8. Solar and Lunar Demonstrators

    Science.gov (United States)

    Ros, Rosa M.

    2009-01-01

    By means of a simple device, made by students themselves, the movements of the Sun and the Moon can be studied at different latitudes. Using this device, it is easy to explain phenomena such as the midnight Sun, zenith pass and why the Moon "smiles". In this article, we show various photos of the Sun's movements, alongside their simulations on the…

  9. 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.

  10. New Sunshine Program for fiscal 2000. Development of photovoltaic system commercialization technology - Development of thin-film solar cell manufacturing technology - Development of low-cost/large area module manufacturing technology (Development of novel amorphous solar cell module manufacturing technology); 2000 nendo New sunshine keikaku seika hokokusho. Taiyoko hatsuden system jitsuyoka gijutsu kaihatsu, Hakumaku taiyodenchi no seizo gijutsu kaihatsu, Tei cost dai menseki mojuru seizo gijutsu kaihatsu (Shingata amorufasu taiyo denchi mojuru no seizo gijutsu kaihatsu)

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-03-01

    Research and development was conducted for the development of amorphous solar cell modules for power generation, high in performance and low in production cost. In the effort to develop high-performance solar cells, optimum device designs including an advanced light confinement structure or the like were studied, and a 25% reduction in the total power generation layer thickness and a 7% increase in efficiency in power generation were consistently achieved in an a-Si/a-SiGe solar cell. In the effort to develop low-cost process technologies, as the result of studies involving the optimization of high-speed film fabrication requirements such as hydrogen dilution and a high-speed/high-precision patterning method and the like, an initial conversion efficiency of 11.2% was attained, which was the world high for a 90 cm times 90 cm-large a-Si/a-SiGe solar cell. This being equivalent to a post-stabilization efficiency of 10%, the fiscal 2000 target was achieved. A solar cell module production cost assessment was performed based on the result, and a module cost of 133 yen/W (in case of 100 MW/year production) was realized, which again meant the achievement of the fiscal 2000 target. (NEDO)

  11. Solar Photovoltaic

    OpenAIRE

    Wang, Chen; Lu, Yuefeng

    2016-01-01

    In the 21st century, human demand for new energy sources is urgent, because the traditional fossil energy is unable to meet human needs, and the fossil resource will make pollution, in this situation, solar energy gradually into the vision of scientists. As science advances, humans can already extensive use of solar energy to generate electricity. Solar energy is an inexhaustible and clean energy. In the global energy crisis, environmental pollution is the growing problem of today. The us...

  12. Solar magnetohydrodynamics

    International Nuclear Information System (INIS)

    Priest, E.R.

    1982-01-01

    The book serves several purposes. First set of chapters gives a concise general introduction to solar physics. In a second set the basic methods of magnetohydrodynamics are developed. A third set of chapters is an account of current theories for observed phenomena. The book is suitable for a course in solar physics and it also provides a comprehensive review of present magnetohydrodynamical models in solar physics. (SC)

  13. Fifteenth DOE solar photochemistry research conference

    Energy Technology Data Exchange (ETDEWEB)

    1991-01-01

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

  14. Solar constraints

    International Nuclear Information System (INIS)

    Provost, J.

    1984-01-01

    Accurate tests of the theory of stellar structure and evolution are available from the Sun's observations. The solar constraints are reviewed, with a special attention to the recent progress in observing global solar oscillations. Each constraint is sensitive to a given region of the Sun. The present solar models (standard, low Z, mixed) are discussed with respect to neutrino flux, low and high degree five-minute oscillations and low degree internal gravity modes. It appears that actually there do not exist solar models able to fully account for all the observed quantities. (Auth.)

  15. Solar Simulator

    Science.gov (United States)

    1981-01-01

    Oriel Corporation's simulators have a high pressure xenon lamp whose reflected light is processed by an optical system to produce a uniform solar beam. Because of many different types of applications, the simulators must be adjustable to replicate many different areas of the solar radiation spectrum. Simulators are laboratory tools for such purposes as testing and calibrating solar cells, or other solar energy systems, testing dyes, paints and pigments, pharmaceuticals and cosmetic preparations, plant and animal studies, food and agriculture studies and oceanographic research.

  16. Advanced Solar Panel Designs

    Science.gov (United States)

    Ralph, E. L.; Linder, E. B.

    1995-01-01

    Solar panel designs that utilize new high-efficiency solar cells and lightweight rigid panel technologies are described. The resulting designs increase the specific power (W/kg) achievable in the near-term and are well suited to meet the demands of higher performance small satellites (smallsats). Advanced solar panel designs have been developed and demonstrated on two NASA SBIR contracts at Applied Solar. The first used 19% efficient, large area (5.5 cm x 6.5 cm) GaAs/Ge solar cells with a lightweight rigid graphite epoxy isogrid substrate configuration. A 1,445 sq cm coupon was fabricated and tested to demonstrate 60 W/kg with a high potential of achieving 80 W/kg. The second panel design used new 22% efficiency, dual-junction GaInP2/GaAs/Ge solar cells combined with a lightweight aluminum core/graphite fiber mesh facesheet substrate. A 1,445 sq cm coupon was fabricated and tested to demonstrate 105 W/kg with the potential of achieving 115 W/kg.

  17. Solar History An Introduction

    CERN Document Server

    Vita-Finzi, Claudio

    2013-01-01

    Beyond the four centuries of sunspot observation and the five decades during which artificial satellites have monitored the Sun – that is to say for 99.99999% of the Sun’s existence – our knowledge of solar history depends largely on analogy with kindred main sequence stars, on the outcome of various kinds of modelling, and on indirect measures of solar activity. They include the analysis of lunar rocks and meteorites for evidence of solar flares and other components of the solar cosmic-ray (SCR) flux, and the measurement of cosmogenic isotopes in wood, stratified ice and marine sediments to evaluate changes in the galactic cosmic-ray (GCR) flux and thus infer changes in the sheltering magnetic fields of the solar wind. In addition, shifts in the global atmospheric circulation which appear to result from cyclic fluctuations in solar irradiance have left their mark in river sediments and in the isotopic composition of cave deposits. In this volume the results these sources have already produced have bee...

  18. Quantum dot solar cell

    International Nuclear Information System (INIS)

    Ahamefula, U.C.; Sulaiman, M.Y.; Sopian, K.; Ibarahim, Z.; Ibrahim, N.; Alghoul, M.A.; Haw, L.C.; Yahya, M.; Amin, N.; Mat, S.; Ruslan, M.H.

    2009-01-01

    Full text: The much awaited desire of replacing fossil fuel with photovoltaic will remain a fairy tale if the myriad of issues facing solar cell development are marginalized. Foremost in the list is the issue of cost. Silicon has reached a stage where its use on large scale can no longer be lavishly depended upon. The demand for high grade silicon from the microelectronics and solar industries has soared leading to scarcity. New approach has to be sought. Notable is the increased attention on thin films such as cadmium telluride, copper indium gallium diselenide, amorphous silicon, and the not so thin non-crystalline family of silicon. While efforts to address the issues of stability, toxicity and efficiency of these systems are ongoing, another novel approach is quietly making its appearance - quantum dots. Quantum dots seem to be promising candidates for solar cells because of the opportunity to manipulate their energy levels allowing absorption of a wider solar spectrum. Utilization of minute quantity of these nano structures is enough to bring the cost of solar cell down and to ascertain sustainable supply of useful material. The paper outlines the progress that has been made on quantum dot solar cells. (author)

  19. The New Solar System

    Science.gov (United States)

    Wilkinson, John

    2009-01-01

    Since 2006, the details of bodies making up our solar system have been revised. This was largely as a result of new discoveries of a number of planet-like objects beyond the orbit of Pluto. The International Astronomical Union redefined what constituted a planet and established two new classifications--dwarf planets and plutoids. As a result, the…

  20. Concentrating solar power

    International Nuclear Information System (INIS)

    Metelli, Enzo; Vignolini, Mauro

    2005-01-01

    Solar energy can be used instead of fossil fuels to produce high-temperature heat for use in many industrial processes and in electricity generation. If carried out on a large scale, the replacement would make it possible to reduce harmful emissions and stabilise the global climate over the long term. ENEA has an innovative project in this sector [it