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Sample records for agency small solar

  1. Small satellite solar array substrate

    NASA Technical Reports Server (NTRS)

    Fiore, John N.; Rosanova, Giulio

    1994-01-01

    The SMall EXplorer (SMEX) Fast Auroral SnapshoT (FAST) spacecraft was developed to investigate plasma physics of auroral phenomena at high orbital altitude. The FAST satellite comprises a variety of deployable booms with sensors on the ends, and instruments that protrude from the main body of the spacecraft to obtain the plasma and electromagnetic fields data. This required the plasma disturbance around the satellite to be kept to a minimum. A non deployable, body mounted solar array was implemented. This led to the design of a light weight solar array substrate with a high degree of structural integrity.

  2. 24 CFR 964.425 - Small public housing agencies.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 24 Housing and Urban Development 4 2011-04-01 2011-04-01 false Small public housing agencies. 964.425 Section 964.425 Housing and Urban Development REGULATIONS RELATING TO HOUSING AND URBAN... § 964.425 Small public housing agencies. (a) General. The requirements of this subpart do not apply...

  3. 24 CFR 964.425 - Small public housing agencies.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 24 Housing and Urban Development 4 2010-04-01 2010-04-01 false Small public housing agencies. 964.425 Section 964.425 Housing and Urban Development Regulations Relating to Housing and Urban... § 964.425 Small public housing agencies. (a) General. The requirements of this subpart do not apply...

  4. Solar Photovoltaic Financing: Deployment by Federal Government Agencies

    SciTech Connect

    Cory, K.; Coggeshall, C.; Coughlin, J.; Kreycik, C.

    2009-07-01

    The goal of this report is to examine how federal agencies can finance on-site PV projects. It explains state-level cash incentives available, the importance of solar renewable energy certificate revenues (in certain markets), existing financing structures, as well as innovative financing structures being used by federal agencies to deploy on-site PV. Specific examples from the DOD, DOE, and other federal agencies are highlighted to explain federal project financing in detail.

  5. International Energy Agency Solar Heating and Cooling Program

    NASA Astrophysics Data System (ADS)

    Brooks, A. J.

    This trip was undertaken to participate in and represent the United States Industry at the International Energy Agency (IEA) Solar Heating and Cooling Program (SHCP) Task 14 Workshop. The meeting took place at the A1 Bani Hotel in Rome Italy.

  6. Observations of small solar flares with BATSE

    NASA Astrophysics Data System (ADS)

    Biesecker, D. A.; Ryan, J. M.; Fishman, G. J.

    1994-12-01

    The Burst and Transient Source Experiment on board the Compton Gamma Ray Observatory is being used to observe solar flares. The Large Area Detectors are sensitive to small solar flares. We are searching the BATSE data for solar flares with an automated algorithm that allows for independent confirmation of the event origin. With this search method, we have detected solar flares almost an order of magnitude smaller than those found in a visual search of the BASTE data. We present results that are consistent with the differential distribution of peak flare rates observed by other researchers. These results show that the rate of occurrence of the smallest flares observed by BATSE can be predicted from the rate of occurrence of larger flares.

  7. Lightweight Solar Power for Small Satellites

    NASA Technical Reports Server (NTRS)

    Nabors, Sammy A.

    2015-01-01

    The innovation targets small satellites or CubeSats for which conventional deployable arrays are not feasible due to their size, weight and complexity. This novel solar cell array includes a thin and flexible photovoltaic cell applied to an inflatable structure to create a high surface area array for collecting solar energy in a lightweight, simple and deployable structure. The inflatable array, with its high functional surface area, eliminates the need and the mechanisms required to point the system toward the sun. The power density achievable in these small arrays is similar to that of conventional high-power deployable/pointable arrays used on large satellites or space vehicles. Although inflatable solar arrays have been previously considered by others, the arrays involved the use of traditional rigid solar cells. Researchers are currently working with thin film photovoltaics from various suppliers so that the NASA innovation is not limited to any particular solar cell technology. NASA has built prototypes and tested functionality before and after inflation. As shown in the current-voltage currents below, deployment does not damage the cell performance.

  8. Fast electrons in small solar flares

    NASA Technical Reports Server (NTRS)

    Lin, R. P.

    1975-01-01

    This review summarizes both the direct spacecraft observations of nonrelativistic solar electrons, and observations of the X-ray and radio emission generated by these particles at the sun and in the interplanetary medium. These observations bear on the basic astrophysical process of particle acceleration in tenuous plasmas. We find that in many small solar flares, the nearly 5-100 keV electrons accelerated during flash phase constitute the bulk of the total flare energy. Thus the basic flare mechanism in these flares essentially converts the available flare energy into fast electrons. These electrons may produce the other flare electromagnetic emissions through their interactions with the solar atmosphere. In large proton flares these electrons may provide the energy to eject material from the sun and to create a shock wave which could accelerate nuclei and electrons to much higher energies.

  9. 24 CFR 964.425 - Small public housing agencies.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 24 Housing and Urban Development 4 2012-04-01 2012-04-01 false Small public housing agencies. 964... DEVELOPMENT (CONTINUED) OFFICE OF ASSISTANT SECRETARY FOR PUBLIC AND INDIAN HOUSING, DEPARTMENT OF HOUSING AND URBAN DEVELOPMENT TENANT PARTICIPATION AND TENANT OPPORTUNITIES IN PUBLIC HOUSING Resident Board...

  10. 24 CFR 964.425 - Small public housing agencies.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 24 Housing and Urban Development 4 2013-04-01 2013-04-01 false Small public housing agencies. 964... DEVELOPMENT (CONTINUED) OFFICE OF ASSISTANT SECRETARY FOR PUBLIC AND INDIAN HOUSING, DEPARTMENT OF HOUSING AND URBAN DEVELOPMENT TENANT PARTICIPATION AND TENANT OPPORTUNITIES IN PUBLIC HOUSING Resident Board...

  11. Development of Deployment System for Small Size Solar Sail Mission

    NASA Astrophysics Data System (ADS)

    Mori, Osamu; Sawada, Hirotaka; Hanaoka, Fuminori; Kawaguchi, Junichiro; Shirasawa, Yoji; Sugita, Masayuki; Miyazaki, Yasuyuki; Sakamoto, Hiraku; Funase, Ryu

    The Japan Aerospace Exploration Agency (JAXA) is studying the feasibility of using the solar power sail as a new propulsion engine for deep space exploration missions. In this paper, the sail shape and equipment layout for missions utilizing small-sized solar power sails are proposed. The two-stage deployment method of the sail is also proposed. The sail need to be deployed statically at the first stage, and two types of deployment mechanisms are introduced. On the other hand the second stage of the deployment can be performed dynamically, and the oscillating motion of the membrane is converged by tethers connecting the membrane to the main body. The deployment motions are analyzed by numerical simulations using multi-particle models in order to verify the deployment. They are compared with the results calculated by finite element method models. The numerical simulation results are discussed from the technological viewpoint of the sail deployment dynamics and mechanisms.

  12. Space Missions to Small Solar System Bodies

    NASA Astrophysics Data System (ADS)

    Scheeres, Daniel

    2012-07-01

    The scientific study of small solar system bodies such as asteroids and comets is of great current interest to the scientific community and to society at large. The exploration of these bodies provides insights into the formational epoch of the solar system and its subsequent evolution. It also provides insights into humanity's future through the better characterization of the properties of these bodies, their potential uses, and how their impact with the Earth could be prevented. The in situ exploration of these bodies provides the best insight into their nature, but are also the most challenging type of exploration. Due to their small size, distended shapes, and wide range of potential spin states, developing systematic exploration methodologies of these bodies is challenging and has spurred the development of non-standard and novel approaches to the study of motion about these bodies. These same techniques that have been developed to better control and understand spacecraft motion about these bodies also provides novel insights into the study of the environment and evolution of these same bodies. These approaches have led to the development of specific predictions of how small bodies evolve in terms of their shape, how they can form binary systems, their spin dynamics, and even their heliocentric orbits. The current talk will summarize our understanding of spacecraft motion and control in the vicinity of small bodies and show how this theory can be translated into improved scientific analysis and understanding of these bodies. Specific case studies will be presented.

  13. Shape Models of Small Solar System Bodies

    NASA Astrophysics Data System (ADS)

    Marks, Scott; Fauerbach, M.; Behrend, R.; Bernasconi, L.; Bosch, J.; Conjat, M.; Rinner, C.; Roy, R.

    2007-10-01

    Shape modeling of small solar system bodies, or asteroids, was performed for the first time at the Evelyn L. Egan Observatory. Asteroids, Greek for "star-like," are generally too small to visually distinguish the shape through Earth-bound observations. Therefore, other means such as lightcurve inversion must be employed to learn about their form. In early 2007 two target candidates for an initial shape modeling study, namely 242 Kriemhild and 287 Nephthys, were chosen because past observations had already been obtained at the Egan Observatory to determine their rotational periods. Numerous photometric observations spanning several apparitions and a wide range of phase angles, particularly large angles, are essential for a precise shape model because the asteroid must be observed from different viewing geometries. As a consequence, a concerted effort between several European and American observatories was initiated to increase accuracy. In conjunction with these observatories, data was collected over three apparitions and an assortment of phase angles, with some greater than 20°, on each of the target asteroids. These data points from relative photometric lightcurves of 242 Kriemhild and 287 Nephthys were imported into the modeling software, which is a derivation of the Kaasalainen algorithm and source code. The Kaasalainen algorithm is a method of forming an asteroid shape model through inversion. Simply put, the program starts with a generic shape and approximate pole orientation. Then it simulates a lightcurve of this form and compares it to the actual lightcurves. If any discrepancies are detected, the software makes the appropriate changes to the current model and the procedure is repeated. Multiple models are generated with different starting pole orientations so that a statistical analysis can be conducted to select the best model and pole orientation. After careful analysis, shape models were found for both target asteroids 242 Kriemhild and 287 Nephthys.

  14. Investigation of small solar system objects with the space telescope

    NASA Technical Reports Server (NTRS)

    Morrison, D.

    1979-01-01

    The application of the space telescope (ST) to study small objects in the solar system in order to understand the birth and the early evolution of the solar system is discussed. The upper size limit of the small bodies is defined as approximately 5000 km and includes planetary satellites, planetary rings, asteroids, and comets.The use of the astronomical instruments aboard the ST, such as the faint object camera, ultraviolet and infrared spectrometers, and spectrophotometers, to study the small solar system objects is discussed.

  15. Solar Decathlon 2011, (Small Program)(Brochure)

    SciTech Connect

    Not Available

    2010-11-01

    This brochure provides a high-level overview of the U.S. Department of Energy Solar Decathlon 2011. The competition's background, purpose, impact, 10 contests, 20 teams, and where to go for additional information.

  16. Transient flows of the solar wind associated with small-scale solar activity in solar minimum

    NASA Astrophysics Data System (ADS)

    Slemzin, Vladimir; Veselovsky, Igor; Kuzin, Sergey; Gburek, Szymon; Ulyanov, Artyom; Kirichenko, Alexey; Shugay, Yulia; Goryaev, Farid

    The data obtained by the modern high sensitive EUV-XUV telescopes and photometers such as CORONAS-Photon/TESIS and SPHINX, STEREO/EUVI, PROBA2/SWAP, SDO/AIA provide good possibilities for studying small-scale solar activity (SSA), which is supposed to play an important role in heating of the corona and producing transient flows of the solar wind. During the recent unusually weak solar minimum, a large number of SSA events, such as week solar flares, small CMEs and CME-like flows were observed and recorded in the databases of flares (STEREO, SWAP, SPHINX) and CMEs (LASCO, CACTUS). On the other hand, the solar wind data obtained in this period by ACE, Wind, STEREO contain signatures of transient ICME-like structures which have shorter duration (<10h), weaker magnetic field strength (<10 nT) and lower proton temperature than usual ICMEs. To verify the assumption that ICME-like transients may be associated with the SSA events we investigated the number of weak flares of C-class and lower detected by SPHINX in 2009 and STEREO/EUVI in 2010. The flares were classified on temperature and emission measure using the diagnostic means of SPHINX and Hinode/EIS and were confronted with the parameters of the solar wind (velocity, density, ion composition and temperature, magnetic field, pitch angle distribution of the suprathermal electrons). The outflows of plasma associated with the flares were identified by their coronal signatures - CMEs (only in few cases) and dimmings. It was found that the mean parameters of the solar wind projected to the source surface for the times of the studied flares were typical for the ICME-like transients. The results support the suggestion that weak flares can be indicators of sources of transient plasma flows contributing to the slow solar wind at solar minimum, although these flows may be too weak to be considered as separate CMEs and ICMEs. The research leading to these results has received funding from the European Union’s Seventh Programme

  17. Solar Cells With Multiple Small Junctions

    NASA Technical Reports Server (NTRS)

    Daud, T.; Koliwad, K. M.

    1985-01-01

    Concept for improving efficiency of photovoltaic solar cells based on decreasing p/n junction area in relation to total surface area of cell. Because of reduced junction area, surface leakage drops and saturation current density decreases. Surface passivation helps to ensure short-circuit current remains at high value and response of cells to blue light increases.

  18. Small bodies of the solar system

    SciTech Connect

    Thomas, P.C. )

    1991-01-01

    This report summarizes some of the significant results achieved in the last four years on asteroids, comets, and small satellites. These objects are interrelated in several ways - some objects may be considered either asteroids or comets; some small satellites may have been comets or asteroids captured into planetary orbits; and these small, low gravity objects are thought to be subject to many common processes. This summary is not comprehensive; rather it focusses on several topics dealing chiefly with the physical characteristics of these small objects. 116 refs.

  19. Solar small-scale dynamo and polarity of sunspot groups

    NASA Astrophysics Data System (ADS)

    Sokoloff, D.; Khlystova, A.; Abramenko, V.

    2015-08-01

    In order to clarify a possible role of small-scale dynamo in formation of solar magnetic field, we suggest an observational test for small-scale dynamo action based on statistics of anti-Hale sunspot groups. As we have shown, according to theoretical expectations the small-scale dynamo action has to provide a population of sunspot groups which do not follow the Hale polarity law, and the density of such groups on the time-latitude diagram is expected to be independent on the phase of the solar cycle. Correspondingly, a percentage of the anti-Hale groups is expected to reach its maximum values during solar minima. For several solar cycles, we considered statistics of anti-Hale groups obtained by several scientific teams, including ours, to find that the percentage of anti-Hale groups becomes indeed maximal during a solar minimum. Our interpretation is that this fact may be explained by the small-scale dynamo action inside the solar convective zone.

  20. TURBULENT SMALL-SCALE DYNAMO ACTION IN SOLAR SURFACE SIMULATIONS

    SciTech Connect

    Graham, Jonathan Pietarila; Cameron, Robert; Schuessler, Manfred

    2010-05-10

    We demonstrate that a magneto-convection simulation incorporating essential physical processes governing solar surface convection exhibits turbulent small-scale dynamo action. By presenting a derivation of the energy balance equation and transfer functions for compressible magnetohydrodynamics, we quantify the source of magnetic energy on a scale-by-scale basis. We rule out the two alternative mechanisms for the generation of the small-scale magnetic field in the simulations: the tangling of magnetic field lines associated with the turbulent cascade and Alfvenization of small-scale velocity fluctuations ('turbulent induction'). Instead, we find that the dominant source of small-scale magnetic energy is stretching by inertial-range fluid motions of small-scale magnetic field lines against the magnetic tension force to produce (against Ohmic dissipation) more small-scale magnetic field. The scales involved become smaller with increasing Reynolds number, which identifies the dynamo as a small-scale turbulent dynamo.

  1. 48 CFR 19.602-3 - Resolving differences between the agency and the Small Business Administration.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... between the agency and the Small Business Administration. 19.602-3 Section 19.602-3 Federal Acquisition Regulations System FEDERAL ACQUISITION REGULATION SOCIOECONOMIC PROGRAMS SMALL BUSINESS PROGRAMS Certificates... and the Small Business Administration. (a) COCs valued between $100,000 and $25,000,000. (1)...

  2. 48 CFR 419.602-3 - Resolving differences between the agency and the Small Business Administration.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... between the agency and the Small Business Administration. 419.602-3 Section 419.602-3 Federal Acquisition Regulations System DEPARTMENT OF AGRICULTURE SOCIOECONOMIC PROGRAMS SMALL BUSINESS PROGRAMS Certificates of... Small Business Administration. The HCA is authorized to appeal the issuance of a COC to SBA...

  3. 48 CFR 19.602-3 - Resolving differences between the agency and the Small Business Administration.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... between the agency and the Small Business Administration. 19.602-3 Section 19.602-3 Federal Acquisition Regulations System FEDERAL ACQUISITION REGULATION SOCIOECONOMIC PROGRAMS SMALL BUSINESS PROGRAMS Certificates... and the Small Business Administration. (a) COCs valued between $100,000 and $25,000,000. (1)...

  4. Radiation forces on small particles in the solar system

    NASA Technical Reports Server (NTRS)

    Burns, J. A.; Lamy, P. L.; Soter, S.

    1979-01-01

    Solar radiation forces on small particles in the solar system are examined, and the resulting orbital evolution of interplanetary and circumplanetary dust is considered. An expression is derived for the effects of radiation pressure and Poynting-Robertson drag on small, spherical particles using the energy and momentum transformation laws of special relativity, and numerical examples are presented to illustrate that radiation pressure and Poynting-Robertson drag are only important for particles within a narrow size range. The orbital consequences of these radiation forces are considered both for heliocentric and planetocentric orbiting particles, and the coupling between particle sizes and dynamics is discussed. A qualitative derivation is presented for the differential Doppler effect, which is due to the differential Doppler shifting of radiation from approaching and receding solar hemispheres, and the Yarkovsky effect, which is important for rotating meter-to kilometer-sized particles, is briefly described.

  5. 78 FR 77139 - Agency Information Collection Activities: Small Vessel Reporting System

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-20

    ... published in the Federal Register (78 FR 61378) on October 3, 2013, allowing for a 60-day comment ] period... SECURITY U.S. Customs and Border Protection Agency Information Collection Activities: Small Vessel Reporting System AGENCY: U.S. Customs and Border Protection, Department of Homeland Security. ACTION:...

  6. 78 FR 61378 - Agency Information Collection Activities: Small Vessel Reporting System

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-10-03

    ... From the Federal Register Online via the Government Publishing Office ] DEPARTMENT OF HOMELAND SECURITY U.S. Customs and Border Protection Agency Information Collection Activities: Small Vessel Reporting System AGENCY: U.S. Customs and Border Protection, Department of Homeland Security. ACTION:...

  7. Study of small magnetic structures in the solar photosphere

    NASA Astrophysics Data System (ADS)

    Cabello, I.; Domingo, V.; Bonet, J. A.; Blanco Rodríguez, J.; Balmaceda, L. A.

    2013-05-01

    The study of small scale magnetic structures in the solar photosphere is of great relevance for the understanding of the global behaviour of the Sun. Because of the small spatial and temporal scales involved, the use of high resolution images and fast cadence is fundamental for their study. In order to obtain such images, sophisticated computational techniques that compensate for the atmospheric degradation and telescope aberration have been developed, improving in this way the spatial resolution. In this work, we use G-band images obtained with the 1 m-Swedish Solar Telescope located at La Palma (Canary Islands, Spain). The images have been restored with MOMFBD (Multi-Object Multi-Frame Blind Deconvolution), a technique that combines multiple images acquired in a short time interval. The resulting images have a resolution close to the diffraction limit of the telescope (0.1 arcsec) allowing the study of very small bright structures present in the inter-granular lanes in the solar photosphere, known as Bright Points. It is highlighted the great presence of magnetic structures in quiet Sun regions analyzed from different observational campaigns. The density of BPs in the quiet Sun shows a decrease as we approach the limb, with values of ≃q 1% at the centre (μ ≈ 1), and ≃q 0.2% at μ ≈ 0.3. We also present the discovery of small vortexes detected in the solar surface through the movement of BPs, with radii around 241 km and lifetimes longer than 5 minutes. Further analyses, comprising longer time series and information from different solar layers, are being performed aiming at a more in-depth knowledge of these phenomena.

  8. On the Dynamics of Small-Scale Solar Magnetic Elements

    NASA Technical Reports Server (NTRS)

    Berger, T. E.; Title, A. M.

    1996-01-01

    We report on the dynamics of the small-scale solar magnetic field, based on analysis of very high resolution images of the solar photosphere obtained at the Swedish Vacuum Solar Telescope. The data sets are movies from 1 to 4 hr in length, taken in several wavelength bands with a typical time between frames of 20 s. The primary method of tracking small-scale magnetic elements is with very high contrast images of photospheric bright points, taken through a 12 A bandpass filter centered at 4305 A in the Fraunhofer 'G band.' Previous studies have established that such bright points are unambiguously associated with sites of small-scale magnetic flux in the photosphere, although the details of the mechanism responsible for the brightening of the flux elements remain uncertain. The G band bright points move in the intergranular lanes at speeds from 0.5 to 5 km/s. The motions appear to be constrained to the intergranular lanes and are primarily driven by the evolution of the local granular convection flow field. Continual fragmentation and merging of flux is the fundamental evolutionary mode of small-scale magnetic structures in the solar photosphere. Rotation and folding of chains or groups of bright points are also observed. The timescale for magnetic flux evolution in active region plage is on the order of the correlation time of granulation (typically 6-8 minutes), but significant morphological changes can occur on timescales as short as 100 S. Smaller fragments are occasionally seen to fade beyond observable contrast. The concept of a stable, isolated subarcsecond magnetic 'flux tube' in the solar photosphere is inconsistent with the observations presented here.

  9. Assessment of the potential of solar thermal small power systems in small utilities

    NASA Technical Reports Server (NTRS)

    Steitz, P.; Mayo, L. G.; Perkins, S. P., Jr.

    1978-01-01

    The potential economic benefit of small solar thermal electric power systems to small municipal and rural electric utilities is assessed. Five different solar thermal small power system configurations were considered in three different solar thermal technologies. The configurations included: (1) 1 MW, 2 MW, and 10 MW parabolic dish concentrators with a 15 kW heat engine mounted at the focal point of each dish, these systems utilized advanced battery energy storage; (2) a 10 MW system with variable slat concentrators and central steam Rankine energy conversion, this system utilized sensible thermal energy storage; and (3) a 50 MW central receiver system consisting of a field of heliostats concentrating energy on a tower-mounted receiver and a central steam Rankine conversion system, this system also utilized sensible thermal storage. The results are summarized in terms of break-even capital costs. The break-even capital cost was defined as the solar thermal plant capital cost which would have to be achieved in order for the solar thermal plants to penetrate 10 percent of the reference small utility generation mix by the year 2000. The calculated break-even capital costs are presented.

  10. European Space Agency studies of the solar probe

    NASA Technical Reports Server (NTRS)

    Roxburgh, I. W.

    1978-01-01

    The feasibility and scientific objectives of a solar probe were studied by a Mission Definition Group in 1975 and 1976. The orbit analysis program was developed and an extended study of the orbit analysis was done in 1977. The results of these studies are in the Report of the Mission Definition Study (1976) and an E.S.O.C. report (1978), and the reader is referred to these sources for greater details. In this report, only brief discussion on mission concept and objectives, satellite design, orbit, orbit analysis, are presented.

  11. Spatial nonlocality of the small-scale solar dynamo

    SciTech Connect

    Lamb, D. A.; Howard, T. A.; DeForest, C. E.

    2014-06-10

    We explore the nature of the small-scale solar dynamo by tracking magnetic features. We investigate two previously explored categories of the small-scale solar dynamo: shallow and deep. Recent modeling work on the shallow dynamo has produced a number of scenarios for how a strong network concentration can influence the formation and polarity of nearby small-scale magnetic features. These scenarios have measurable signatures, for which we test using magnetograms from the Narrowband Filter Imager (NFI) on board Hinode. We find no statistical tendency for newly formed magnetic features to cluster around or away from network concentrations, nor do we find any statistical relationship between their polarities. We conclude that there is no shallow or 'surface' dynamo on the spatial scales observable by Hinode/NFI. In light of these results, we offer a scenario in which the subsurface field in a deep solar dynamo is stretched and distorted via turbulence, allowing the small-scale field to emerge at random locations on the photosphere.

  12. Small solar thermal electric power plants with early commercial potential

    NASA Technical Reports Server (NTRS)

    Jones, H. E.; Bisantz, D. J.; Clayton, R. N.; Heiges, H. H.; Ku, A. C.

    1979-01-01

    Cost-effective small solar thermal electric power plants (1- to 10-MW nominal size) offer an attractive way of helping the world meet its future energy needs. The paper describes the characteristics of a conceptual near-term plant (about 1 MW) and a potential 1990 commercial version. The basic system concept is one in which steam is generated using two-axis tracking, parabolic dish, and point-focusing collectors. The steam is transported through low-loss piping to a central steam turbine generator unit where it is converted to electricity. The plants have no energy storage and their output power level varies with the solar insolation level. This system concept, which is firmly based on state-of-the-art technology, is projected to offer one of the fastest paths for U.S. commercialization of solar thermal electric power plants through moderate technology advances and mass production.

  13. Small solar wind transients: Stereo-A observations in 2009

    SciTech Connect

    Yu, W.; Farrugia, C. J.; Galvin, A. B.; Simunac, K. D. C.; Popecki, M. A.; Lugaz, N.; Kilpua, E. K. J.; Moestl, C.; Luhmann, J. G.; Opitz, A.; Sauvaud, J.-A.

    2013-06-13

    Year 2009 was the last year of a long and pronounced solar activity minimum. In this year the solar wind in the inner heliosphere was for 90% of the time slow (< 450 km s{sup -1}) and with a weaker magnetic field strength compared to the previous solar minimum 1995-1996. We choose this year to present the results of a systematic search for small solar wind transients (STs) observed by the STEREO-Ahead (ST-A) probe. The data are from the PLASTIC and IMPACT instrument suites. By 'small' we mean a duration from {approx}1 to 12 hours. The parameters we search for to identify STs are (i) the total field strength, (ii) the rotation of the magnetic field vector, (iii) its smoothness, (iv) proton temperature, (v) proton beta, and (vi) Alfven Mach number. We find 45 examples. The STs have an average duration of {approx}4 hours. Ensemble averages of key quantities are: (i) maximum B = 7.01 nT; (ii) proton {beta}= 0.18; (iii) proton thermal speed = 20.8 km s{sup -1}; and (iv) Alfven Mach number = 6.13. No distinctive feature is found in the pitch angle distributions of suprathermal electrons. Our statistical results are compared with those of STs observed near Earth by Wind during 2009.

  14. Small solar wind transients: Stereo-A observations in 2009

    NASA Astrophysics Data System (ADS)

    Yu, W.; Farrugia, C. J.; Galvin, A. B.; Simunac, K. D. C.; Kilpua, E. K. J.; Popecki, M. A.; Moestl, C.; Lugaz, N.; Luhmann, J. G.; Opitz, A.; Sauvaud, J.-A.

    2013-06-01

    Year 2009 was the last year of a long and pronounced solar activity minimum. In this year the solar wind in the inner heliosphere was for 90% of the time slow (< 450 km s-1) and with a weaker magnetic field strength compared to the previous solar minimum 1995-1996. We choose this year to present the results of a systematic search for small solar wind transients (STs) observed by the STEREO-Ahead (ST-A) probe. The data are from the PLASTIC and IMPACT instrument suites. By "small" we mean a duration from ~1 to 12 hours. The parameters we search for to identify STs are (i) the total field strength, (ii) the rotation of the magnetic field vector, (iii) its smoothness, (iv) proton temperature, (v) proton beta, and (vi) Alfvén Mach number. We find 45 examples. The STs have an average duration of ~4 hours. Ensemble averages of key quantities are: (i) maximum B = 7.01 nT; (ii) proton β = 0.18; (iii) proton thermal speed = 20.8 km s-1 and (iv) Alfvén Mach number = 6.13. No distinctive feature is found in the pitch angle distributions of suprathermal electrons. Our statistical results are compared with those of STs observed near Earth by Wind during 2009.

  15. 76 FR 82314 - Agency Information Collection Activities: Small Vessel Reporting System

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-12-30

    ... published in the Federal Register (76 FR 65206) on October 20, 2011, allowing for a 60- day comment period... SECURITY U.S. Customs and Border Protection Agency Information Collection Activities: Small Vessel... accordance with the Paperwork Reduction Act: the Small Vessel Reporting System (SVRS). CBP is proposing...

  16. 76 FR 65206 - Agency Information Collection Activities: Small Vessel Reporting System

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-10-20

    ... SECURITY U.S. Customs and Border Protection Agency Information Collection Activities: Small Vessel... Vessel Reporting System (SVRS). This request for comment is being made pursuant to the Paperwork... concerning the following information collection: Title: Small Vessel Reporting System. OMB Number: Will...

  17. 77 FR 70210 - Agency Information Collection (VA Subcontracting Report for Service Disabled Veteran-owned Small...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-11-23

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF VETERANS AFFAIRS Agency Information Collection (VA Subcontracting Report for Service Disabled Veteran-owned Small....'' SUPPLEMENTARY INFORMATION: Title: VA Subcontracting Report for Service Disabled Veteran-owned Small Business...

  18. Small Power Systems Solar Electric Workshop Proceedings. Volume 1: Executive report. Volume 2: Invited papers

    NASA Technical Reports Server (NTRS)

    Ferber, R. (Editor); Evans, D. (Editor)

    1978-01-01

    The background, objectives and methodology used for the Small Power Systems Solar Electric Workshop are described, and a summary of the results and conclusions developed at the workshop regarding small solar thermal electric power systems is presented.

  19. Non-Solar Photovoltaics for Small Space Missions

    NASA Technical Reports Server (NTRS)

    Landis, Geoffrey A.; Bailey, Sheila G.; Clark, Eric B.; Myers, Matthew G.; Piszazor, Michael F.; Murbach, Marcus S.

    2012-01-01

    NASA has missions planned to targets in the solar system ranging from the permanently shadowed craters of Mercury to the icy reaches of the Kuiper belt and beyond. In 2011, the NASA Office of the Chief Technologist (OCT) requested the NASA Ames and Glenn Research Centers to assess the potential of small power supplies based on direct conversion of energy from radioisotope sources for future NASA missions; and in particular to assess whether alphavoltaic and betavoltaic power sources could be of potential benefit in small missions, as well as examining the use of miniaturized thermophotovoltaic power supplies. This paper summarizes the results of that assessment.

  20. Small Explorers - Small is beautiful. [Solar, Anomalous, and Magnetospheric Particles Explorer (SAMPEX)

    NASA Technical Reports Server (NTRS)

    Gilman, David

    1990-01-01

    NASA's Small Explorer Program aims to achieve a flight rate of one mission per year in a program of small scientific satellites launched from small expendable launch vehicles. The Program is developing 3 missions for launch in the early 1990's: the Solar, Anomalous, and Magnetospheric Particle Explorer (SAMPEX), the Submillimeter Wave Astronomy Satellite (SWAS), and the Fast Auroral Snapshot Explorer (FAST). This paper gives an overview of the program, a description of the selected missions, the approach to developing the missions and the plans for the next Announcement of Opportunity.

  1. The speckle image reconstruction of the solar small scale features

    NASA Astrophysics Data System (ADS)

    Zhong, Libo; Tian, Yu; Rao, Changhui

    2014-11-01

    The resolution of the astronomical object observed by the earth-based telescope is limited due to the atmospheric turbulence. Speckle image reconstruction method provides access to detect small-scale solar features near the diffraction limit of the telescope. This paper describes the implementation of the reconstruction of images obtained by the 1-m new vacuum solar telescope at Full-Shine solar observatory. Speckle masking method is used to reconstruct the Fourier phases for its better dynamic range and resolution capabilities. Except of the phase reconstruction process, several problems encounter in the solar image reconstruction are discussed. The details of the implement including the flat-field, image segmentation, Fried parameter estimation and noise filter estimating are described particularly. It is demonstrated that the speckle image reconstruction is effective to restore the wide field of view images. The qualities of the restorations are evaluated by the contrast ratio. When the Fried parameter is 10cm, the contrast ratio of the sunspot and granulation can be improved from 0.3916 to 0.6845 and from 0.0248 to 0.0756 respectively.

  2. Variability of Kepler Solar-like Stars Harboring Small Exoplanets

    NASA Astrophysics Data System (ADS)

    Howell, Steve B.; Ciardi, David R.; Giampapa, Mark S.; Everett, Mark E.; Silva, David R.; Szkody, Paula

    2016-02-01

    We examine Kepler light-curve variability on habitable zone transit timescales for a large uniform sample of spectroscopically studied Kepler exoplanet host stars. The stars, taken from Everett et al., are solar-like in their properties and each harbors at least one exoplanet (or candidate) of radius ≤2.5 {R}{{e}}. The variability timescale examined is typical for habitable zone planets orbiting solar-like stars and we note that the discovery of the smallest exoplanets (≤1.2 {R}{{e}}) with corresponding transit depths of less than ∼0.18 mmag occur for the brightest and photometrically quietest stars. Thus, these detections are quite rare in Kepler observations. Some brighter and more evolved stars (subgiants), the latter of which often show large radial velocity jitter, are found to be among the photometrically quietest solar-like stars in our sample and the most likely small planet transit hunting grounds. The Sun is discussed as a solar-like star proxy to provide insight into the nature and cause of photometric variability. It is shown that Kepler’s broad, visible light observations are insensitive to variability caused by chromospheric activity that may be present in the observed stars.

  3. Ammonium sulfate solar pond: Observations from small-scale experiments

    SciTech Connect

    Hull, J.R. ); Bushnell, D.L.; Sempsrote, D.G. ); Pena, A. )

    1989-01-01

    Using the fertilizer salt (NH{sub 4}){sub 2}SO{sub 4}, the authors established a salinity gradient solar pond in a small outdoor tank. The hydrodynamic and thermal behavior of the pond was similar to that observed in the past for solar ponds containing NaCl. For temperature gradients between 50 and 300 K/m and salinity gradients between 200 and 1400 kg/m{sup 4}, data relating the gradients to erosion and growth of the gradient zone were generally consistent with the Nielsen boundary criterion for NaCl. With a salinity difference of 20% between the upper and lower zones and a maximum lower-zone temperature of 83{degree}C, no instabilities were observed in the interior of the gradient zone. Sodium hypochlorite was effective in controlling algal populations and maintaining good brine transparency.

  4. 3D Location of Small Solar Wind Tracers

    NASA Astrophysics Data System (ADS)

    Lopez-Portela, C.; Blanco-Cano, X.; Panasenco, O.; Gibson, S. E.

    2014-12-01

    The so-called "blobs" as defined in Sheeley et al., 1997, are small-scale structures embedded in the continuously expanding white-light solar corona and are considered to be tracers of the slow solar wind. As blobs are very faint structures, we considered long periods (around 2 to 5 days) where there were no coronal mass ejections (CME). The scarce presence of CMEs during the extended past solar minimum has permitted the identification of continuous blobs detachments, allowing us to estimate their un-projected trajectories between 2 and 15 solar radii (Mierla et al., 2008). In agreement with the idea that blobs are liberated from the cusps of helmet steamers (Wang et al., 1998), we constrained the observing region of interest in the coronagraphs field of view to ±30° from the Sun's equator. We studied cases where blobs were detected by the coronagraphs C2/LASCO and COR2/SECCHI, and inferred their source locations using two packages that implement the 3D potential field source surface (PFSS) model: (1) PFSS developed by De Rosa (2010) and (2) PFSS (De Rosa) in FORWARD (people.hao.ucar.edu/sgibson/FORWARD/). The locations of the origin of blobs that we find, support previous results that track down the origin of the slow solar wind to regions near the helmet streamers and pseudostreamers (Wang et al., 2012, Riley&Luhmann, 2012). Additionally, we found that in some cases blobs are coming from the boundaries of growing or decaying equatorial coronal holes, where the interchange reconnection issupposed to be faster.

  5. Small scale MHD wave processes in the solar atmosphere and solar wind

    NASA Technical Reports Server (NTRS)

    Hollweg, Joseph V.

    1987-01-01

    Solar wind observations suggesting wave-particle interactions via ion-cyclotron resonances are reviewed. The required power at high frequencies is presumably supplied via a turbulent cascade. Tu's (1987) model, which considers a turbulent cascade explicitly, is outlined. In the solar atmosphere, resonance absorption is considered. The meanings of the cusp and Alfven resonances are discussed, and it is shown how energy gets pumped into small scales. It is shown that resonance absorption can heat the corona and spicules in a manner consistent with observations, if turbulence provides an eddy viscosity.

  6. SPS market analysis. [small solar thermal power systems

    NASA Technical Reports Server (NTRS)

    Goff, H. C.

    1980-01-01

    A market analysis task included personal interviews by GE personnel and supplemental mail surveys to acquire statistical data and to identify and measure attitudes, reactions and intentions of prospective small solar thermal power systems (SPS) users. Over 500 firms were contacted, including three ownership classes of electric utilities, industrial firms in the top SIC codes for energy consumption, and design engineering firms. A market demand model was developed which utilizes the data base developed by personal interviews and surveys, and projected energy price and consumption data to perform sensitivity analyses and estimate potential markets for SPS.

  7. Funding Solar Projects at Federal Agencies: Mechanisms and Selection Criteria (Brochure)

    SciTech Connect

    Not Available

    2012-03-01

    Implementing solar energy projects at federal facilities is a process. The project planning phase of the process includes determining goals, building a team, determining site feasibility and selecting the appropriate project funding tool. This fact sheet gives practical guidance to assist decision-makers with understanding and selecting the funding tool that would best address their site goals. Because project funding tools are complex, federal agencies should seek project assistance before making final decisions. High capital requirements combined with limits on federal agency energy contracts create challenges for funding solar projects. Solar developers typically require long-term contracts (15-20) years to spread out the initial investment and to enable payments similar to conventional utility bill payments. In the private sector, 20-year contracts have been developed, vetted, and accepted, but the General Services Administration (GSA) contract authority (federal acquisition regulation [FAR] part 41) typically limits contract terms to 10 years. Payments on shorter-term contracts make solar economically unattractive compared with conventional generation. However, in several instances, the federal sector has utilized innovative funding tools that allow long-term contracts or has created a project package that is economically attractive within a shorter contract term.

  8. A solar thermal electric power plant for small communities

    NASA Technical Reports Server (NTRS)

    Holl, R. J.

    1979-01-01

    A solar power plant has been designed with a rating of 1000-kW electric and a 0.4 annual capacity factor. It was configured as a prototype for plants in the 1000 to 10,000-kWe size range for application to small communities or industrial users either grid-connected or isolated from a utility grid. A small central receiver was selected for solar energy collection after being compared with alternative distributed collectors. Further trade studies resulted in the selection of Hitec (heat transfer salt composed of 53 percent KNO3, 40 percent NaNO2, 7 percent NaNO3) as both the receiver coolant and the sensible heat thermal stroage medium and the steam Rankine cycle for power conversion. The plant is configured with road-transportable units to accommodate remote sites and minimize site assembly requirements. Results of the analyses indicate that busbar energy costs are competitive with diesel-electric plants in certain situations, e.g., off-grid, remote regions with high insolation. Sensitivity of energy costs to plant power rating and system capacity factor are given.

  9. Small Solar Electric Propulsion Spacecraft Concept for Near Earth Object and Inner Solar System Missions

    NASA Technical Reports Server (NTRS)

    Lang, Jared J.; Randolph, Thomas M.; McElrath, Timothy P.; Baker, John D.; Strange, Nathan J.; Landau, Damon; Wallace, Mark S.; Snyder, J. Steve; Piacentine, Jamie S.; Malone, Shane; Bury, Kristen M.; Tracy, William H.

    2011-01-01

    Near Earth Objects (NEOs) and other primitive bodies are exciting targets for exploration. Not only do they provide clues to the early formation of the universe, but they also are potential resources for manned exploration as well as provide information about potential Earth hazards. As a step toward exploration outside Earth's sphere of influence, NASA is considering manned exploration to Near Earth Asteroids (NEAs), however hazard characterization of a target is important before embarking on such an undertaking. A small Solar Electric Propulsion (SEP) spacecraft would be ideally suited for this type of mission due to the high delta-V requirements, variety of potential targets and locations, and the solar energy available in the inner solar system.Spacecraft and mission trades have been performed to develop a robust spacecraft design that utilizes low cost, off-the-shelf components that could accommodate a suite of different scientific payloads for NEO characterization. Mission concepts such as multiple spacecraft each rendezvousing with different NEOs, single spacecraft rendezvousing with separate NEOs, NEO landers, as well as other inner solar system applications (Mars telecom orbiter) have been evaluated. Secondary launch opportunities using the Expendable Secondary Payload Adapter (ESPA) Grande launch adapter with unconstrained launch dates have also been examined.

  10. Development status of the small community solar power system

    NASA Technical Reports Server (NTRS)

    Pons, R. L.

    1982-01-01

    The development status and test results for the Small Community Solar Thermal Power Experiment are presented. Activities on the phase 2 power module development effort are presented with emphasis on the receiver, the plant control subsystem, and the energy transport subsystem. The components include a single prototype power module consisting of a parabolic dish concentrator, a power conversion assembly (PCA), and a multiple-module plant control subsystem. The PCA consists of a cavity receiver coupled to an organic Rankine cycle engine-alternator unit defined as the power conversion subsystem; the PCA is mounted at the focus of a parabolic dish concentrator. At a solar insolation of 100 W/sq m and ambient temperature of 28 C (82 F), the power module produces approximately 20 kW of 3-phase, 3 kHz ac power, depending on the concentrator employed. A ground-mounted rectifier to the central collection site where it is supplied directly to the common dc bus which collects the power from all modules in the plant.

  11. The Virtual Solar Observatory: Still a Small Box

    NASA Technical Reports Server (NTRS)

    Gurman, J. B.; Bogart, R. S.; Davey, A. R.; Dimitoglou, G.; Hill, F.; Hourcle, J. A.; Martens, P. C.; Surez-Sola, I.; Tian, K. Q.; Wampler, S.

    2005-01-01

    Two and a half years after a design study began, and a year and a half after development commenced, version 1.0 of the Virtual Solar Observatory (VSO) was released at the 2004 Fall AGU meeting. Although internal elements of the VSO have changed, the basic design has remained the same, reflecting the team's belief in the importance of a simple, robust mechanism for registering data provider holdings, initiating queries at the appropriate provider sites, aggregating the responses, allowing the user to iterate before making a final selection, and enabling the delivery of data directly from the providers. In order to make the VSO transparent, lightweight, and portable, the developers employed XML for the registry, SOAP for communication between a VSO instance and data services, and HTML for the graphic user interface (GUI's). We discuss the internal data model, the API, and user responses to various trial GUI's as typical design issues for any virtual observatory. We also discuss the role of the "small box" of data search, identification, and delivery services provided by the VSO in the larger, Sun-Solar System Connection virtual observatory (VxO) scheme.

  12. Development of the small community solar power system

    NASA Technical Reports Server (NTRS)

    Babbe, R. H.

    1981-01-01

    The status of the Small Community Solar Thermal Power Experiment is presented. Activities on the Phase 2 single/module development effort are presented, together with plans for the Phase 3 1 MWe demonstration plant. A description of the various subsystems and components is given with emphasis on the unmanned microprocessor based plant control subsystem. Latest performance figures are given for the 1 MWe plant, based on 56 power modules, each consisting of a 12m low cost concentrator, a cavity receiver, a Rankine power conversion subsystem and a ground mounted solid-state rectifier. Overall plant efficiency at rated conditions is 15.8 percent. Advanced glass concentrator designs yield 20 percent overall efficiencies.

  13. Small Solar System Objects Spectroscopic Survey: First Results

    NASA Astrophysics Data System (ADS)

    Lazzaro, D.; Angeli, C. A.; Florczak, M.; Betzler, A.; Barucci, M. A.; Fulchignoni, M.

    1997-07-01

    We began a systematic study of primitive bodies, called S(3OS^2) , Small Solar System Objects Spectroscopic Survey. Among the objects we are studying are: Near-Earth objects, asteroid families, asteroids near resonances, dark objects, Centaurs, objects representing a possible transition comet-asteroid, and asteroids with a very slow or complex rotation. The chemical and mineralogical composition of an asteroid's surface is studied through the analysis of its reflectance spectra in different wavelenghts. Four observation missions were carried out at the European Southern Observatory (La Silla, Chile), when we obtained a mineral characterization of about 300 asteroids. The observations were realized with a 1.52 m telescope with a Boller & Chivens spectrograph and a 2048x2048 CCD. The spectra were obtained in wavelenghts from 3000 to 9200 { Angstroms} and were reduced using the IRAF reduction package with usual techniques like flat-field, He-Ar lamps and solar analogs. Concerning concentrations in the Main Belt due to resonances with Jupiter, we present the initial results of Cybeles, Hildas, Hungarias, NEAs and Phocaea. We observed also, along all its opposition, the Centaur object 2060 Chiron, that displays a small cometary activity represented by variations in its reflectance spectrum. Concerning asteroid families, concentrations we believe are debris of an energetic collision causing the total breakup of the original bodies, we observed members of Adeona, Dora, Eos, Eunomia, Flora, Merxia and Themis. The Main Belt is represented in our sample by Flora, in the most inner region, Eunomia, Adeona, Dora and Merxia in the intermediary region, and Themis and Eos representing the most outer region of the belt. *Based on observations made with the 1.52 m telescope at the European Southern Observatory (La Silla, Chile) under the agreement with the CNPq/Observatorio Nacional (Brazil).

  14. Solar and Magnetic Attitude Determination for Small Spacecraft

    NASA Technical Reports Server (NTRS)

    Woodham, Kurt; Blackman, Kathie; Sanneman, Paul

    1997-01-01

    During the Phase B development of the NASA New Millennium Program (NMP) Earth Orbiter-1 (EO-1) spacecraft, detailed analyses were performed for on-board attitude determination using the Sun and the Earth's magnetic field. This work utilized the TRMM 'Contingency Mode' as a starting point but concentrated on implementation for a small spacecraft without a high performance mechanical gyro package. The analyses and simulations performed demonstrate a geographic dependence due to diurnal variations in the Earth magnetic field with respect to the Sun synchronous, nearly polar orbit. Sensitivity to uncompensated residual magnetic fields of the spacecraft and field modeling errors is shown to be the most significant obstacle for maximizing performance. Performance has been evaluated with a number of inertial reference units and various mounting orientations for the two-axis Fine Sun Sensors. Attitude determination accuracy using the six state Kalman Filter executing at 2 Hz is approximately 0.2 deg, 3-sigma, per axis. Although EO-1 was subsequently driven to a stellar-based attitude determination system as a result of tighter pointing requirements, solar/magnetic attitude determination is demonstrated to be applicable to a range of small spacecraft with medium precision pointing requirements.

  15. Proceedings of Small Power Systems Solar Electric Workshop. Volume 2: Invited papers

    NASA Technical Reports Server (NTRS)

    Ferber, R. (Editor)

    1978-01-01

    The focus of this work shop was to present the committment to the development of solar thermal power plants for a variety of applications including utility applications. Workshop activities included panel discussions, formal presentations, small group interactive discussions, question and answer periods, and informal gatherings. Discussion on topics include: (1) solar power technology options; (2) solar thermal power programs currently underway at the DOE, JPL, Electric Power Research Institute (EPRI), and Solar Energy Research Institute (SERI); (3) power options competing with solar; (4) institutional issues; (5) environmental and siting issues; (6) financial issues; (7) energy storage; (8) site requirements for experimental solar installations, and (9) utility planning.

  16. Dynamic properties of small-scale solar wind plasma fluctuations

    PubMed Central

    Riazantseva, M. O.; Budaev, V. P.; Zelenyi, L. M.; Zastenker, G. N.; Pavlos, G. P.; Safrankova, J.; Nemecek, Z.; Prech, L.; Nemec, F.

    2015-01-01

    The paper presents the latest results of the studies of small-scale fluctuations in a turbulent flow of solar wind (SW) using measurements with extremely high temporal resolution (up to 0.03 s) of the bright monitor of SW (BMSW) plasma spectrometer operating on astrophysical SPECTR-R spacecraft at distances up to 350 000 km from the Earth. The spectra of SW ion flux fluctuations in the range of scales between 0.03 and 100 s are systematically analysed. The difference of slopes in low- and high-frequency parts of spectra and the frequency of the break point between these two characteristic slopes was analysed for different conditions in the SW. The statistical properties of the SW ion flux fluctuations were thoroughly analysed on scales less than 10 s. A high level of intermittency is demonstrated. The extended self-similarity of SW ion flux turbulent flow is constantly observed. The approximation of non-Gaussian probability distribution function of ion flux fluctuations by the Tsallis statistics shows the non-extensive character of SW fluctuations. Statistical characteristics of ion flux fluctuations are compared with the predictions of a log-Poisson model. The log-Poisson parametrization of the structure function scaling has shown that well-defined filament-like plasma structures are, as a rule, observed in the turbulent SW flows. PMID:25848078

  17. Dynamic properties of small-scale solar wind plasma fluctuations.

    PubMed

    Riazantseva, M O; Budaev, V P; Zelenyi, L M; Zastenker, G N; Pavlos, G P; Safrankova, J; Nemecek, Z; Prech, L; Nemec, F

    2015-05-13

    The paper presents the latest results of the studies of small-scale fluctuations in a turbulent flow of solar wind (SW) using measurements with extremely high temporal resolution (up to 0.03 s) of the bright monitor of SW (BMSW) plasma spectrometer operating on astrophysical SPECTR-R spacecraft at distances up to 350,000 km from the Earth. The spectra of SW ion flux fluctuations in the range of scales between 0.03 and 100 s are systematically analysed. The difference of slopes in low- and high-frequency parts of spectra and the frequency of the break point between these two characteristic slopes was analysed for different conditions in the SW. The statistical properties of the SW ion flux fluctuations were thoroughly analysed on scales less than 10 s. A high level of intermittency is demonstrated. The extended self-similarity of SW ion flux turbulent flow is constantly observed. The approximation of non-Gaussian probability distribution function of ion flux fluctuations by the Tsallis statistics shows the non-extensive character of SW fluctuations. Statistical characteristics of ion flux fluctuations are compared with the predictions of a log-Poisson model. The log-Poisson parametrization of the structure function scaling has shown that well-defined filament-like plasma structures are, as a rule, observed in the turbulent SW flows. PMID:25848078

  18. Gamma-Ray Burst Polarimeter (GAP) aboard the Small Solar Power Sail Demonstrator IKAROS

    NASA Astrophysics Data System (ADS)

    Yonetoku, Daisuke; Murakami, Toshio; Gunji, Shuichi; Mihara, Tatehiro; Sakashita, Tomonori; Morihara, Yoshiyuki; Kikuchi, Yukihiro; Takahashi, Takuya; Fujimoto, Hirofumi; Toukairin, Noriyuki; Kodama, Yoshiki; Kubo, Shin; Ikaros Demonstration Team

    2011-06-01

    The small solar-power sail demonstrator ``IKAROS'' is a Japanese engineering verification spacecraft launched by the H-IIA rocket on 2010 May 21 at Japan Aerospace Exploration Agency (JAXA) Tanegashima Space Center. IKAROS has a 20 m diameter sail, which is made of a thin polyimide membrane. The sail converts the solar radiation-pressure into the propulsion force of IKAROS, and accelerates the spacecraft. The Gamma-Ray Burst Polarimeter (GAP) aboard IKAROS is the first polarimeter specifically designed to measure the polarization of Gamma-Ray Bursts (GRBs) from space, and will do so in the cruising phase of the IKAROS mission. GAP is a modest detector of 3.8 kg in weight and 17 cm in size with an energy range of between 50-300 keV. The GAP detector is now a member of the interplanetary network (IPN) for determining the GRB direction. The detection principle of gamma-ray polarization is the anisotropy of the Compton scattering. Coincidence between the central plastic Compton scattering medium and discrete CsI detectors distributed around the sides of the plastic defines the Compton-scattering angle, which is expected to show an angular dependence if polarization is present in a given GRB. In this paper, we present the GAP detector and its ground-based and onboard calibrations.

  19. Thermal power systems small power systems application project: Siting issues for solar thermal power plants with small community applications

    NASA Technical Reports Server (NTRS)

    Holbeck, H. J.; Ireland, S. J.

    1979-01-01

    The siting issues associated with small, dispersed solar thermal power plants for utility/small community applications of less than 10 MWe are reported. Some specific requirements are refered to the first engineering experiment for the Small Power Systems Applications (SPSA) Project. The background for the subsequent issue discussions is provided. The SPSA Project and the requirements for the first engineering experiment are described, and the objectives and scope for the report as a whole. A overview of solar thermal technologies and some technology options are discussed.

  20. Solar thermal power plants in small utilities - An economic impact analysis

    NASA Technical Reports Server (NTRS)

    Bluhm, S. A.; Ferber, R. R.; Mayo, L. G.

    1979-01-01

    A study was performed to assess the potential economic impact of small solar thermal electric power systems in statistically representative synthetic small utilities of the Southwestern United States. Power supply expansion plans were compared on the basis of present worth of future revenue requirements for 1980-2000 with and without solar thermal plants. Coal-fired and oil-fired municipal utility expansion plans with 5 percent solar penetration were 0.5 percent and 2.25 percent less expensive, respectively, than the corresponding conventional plan. At $969/kWe, which assumes the same low cost solar equipment but no improvement in site development costs, solar penetration of 5 percent in the oil-fired municipal reduced revenue requirements 0.88 percent. The paper concludes that some solar thermal plants are potentially economic in small community utilities of the Southwest.

  1. Small integrated solar energy systems for developing countries

    NASA Astrophysics Data System (ADS)

    Schreitmueller, K. R.

    1982-11-01

    Solar enegy applications in developing countries cover processing of food and other agricultural products, fresh water production, operation of cooling and freezing equipment, of water pumps and processing machinery. Evacuated tubular collectors turn out to be best suited for process heat generation; photovoltaic generators for electricity production. The Mexican fisher village of Las Barrancas gives a good example of an integrated solar energy system.

  2. Simulation of turbulent magnetic reconnection in the small-scale solar wind.

    NASA Astrophysics Data System (ADS)

    Wei, Fengsi; Qiang, Hu; Schwen, R.; Feng, Xueshang

    2000-06-01

    Some observational examples for the possible occurrence of the turbulent magnetic reconnection in the solar wind are found by analysing Hellos spacecraft's high resolution data. The phenomena of turbulent magnetic reconnections in small scale solar wind are simulated by introducing a third order accuracy upwind compact difference scheme to the compressible two-dimensional MHD flow. Numerical results verify that the turbulent magnetic reconnection process could occur in small scale interplanetary solar wind, which is a basic feature characterizing the magnetic reconnection in high-magnetic Reynolds number solar wind.

  3. Dynamical evolution of small bodies in the Solar System

    NASA Astrophysics Data System (ADS)

    Jacobson, Seth A.

    2012-05-01

    This thesis explores the dynamical evolution of small bodies in the Solar System. It focuses on the asteroid population but parts of the theory can be applied to other systems such as comets or Kuiper Belt objects. Small is a relative term that refers to bodies whose dynamics can be significantly perturbed by non-gravitational forces and tidal torques on timescales less than their lifetimes (for instance the collisional timescale in the Main Belt asteroid population or the sun impact timescale for the near-Earth asteroid population). Non-gravitational torques such as the YORP effect can result in the active endogenous evolution of asteroid systems; something that was not considered more than twenty years ago. This thesis is divided into three independent studies. The first explores the dynamics of a binary systems immediately after formation from rotational fission. The rotational fission hypothesis states that a rotationally torqued asteroid will fission when the centrifugal accelerations across the body exceed gravitational attraction. Asteroids must have very little or no tensile strength for this to occur, and are often referred to as "rubble piles.'' A more complete description of the hypothesis and the ensuing dynamics is provided there. From that study a framework of asteroid evolution is assembled. It is determined that mass ratio is the most important factor for determining the outcome of a rotational fission event. Each observed binary morphology is tied to this evolutionary schema and the relevant timescales are assessed. In the second study, the role of non-gravitational and tidal torques in binary asteroid systems is explored. Understanding the competition between tides and the YORP effect provides insight into the relative abundances of the different binary morphologies and the effect of planetary flybys. The interplay between tides and the BYORP effect creates dramatic evolutionary pathways that lead to interesting end states including stranded

  4. New solar telescope in Big Bear: evidence for super-diffusivity and small-scale solar dynamos?

    NASA Astrophysics Data System (ADS)

    Goode, Philip R.; Abramenko, Valentyna; Yurchyshyn, Vasyl

    2012-07-01

    The 1.6 m clear aperture New Solar Telescope (NST) in Big Bear Solar Observatory (BBSO) is now providing the highest resolution solar data ever. These data have revealed surprises about the Sun on small-scales including the observation that bright points (BPs), which can be used as proxies for the intense, compact magnetic elements that are apparent in photospheric intergranular lanes. The BPs are ever more numerous on ever smaller spatial scales as though there were no limit to how small the BPs can be. Here we discuss high resolution NST data on BPs that provide support for the ideas that a turbulent regime of super-diffusivity dominates in the quiet Sun, and there are local dynamos operating near the solar surface.

  5. 77 FR 36532 - Review of Small Generator Interconnection Agreements and Procedures; Solar Energy Industries...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-19

    ...-001; ER12-1855-000] Review of Small Generator Interconnection Agreements and Procedures; Solar Energy....gov/whats-new/registration/small-generator-7-17-12-form.asp . The purpose of this conference is to...: https://www.ferc.gov/whats-new/registration/small-generator-7-17-12-speaker-form.asp . Due to...

  6. 41 CFR 102-118.130 - Must my agency use a GBL for express, courier, or small package shipments?

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... for express, courier, or small package shipments? 102-118.130 Section 102-118.130 Public Contracts and... Transportation Services § 102-118.130 Must my agency use a GBL for express, courier, or small package shipments? No, however, in using commercial forms all shipments must be subject to the terms and conditions...

  7. A preliminary assessment of small steam Rankine and Brayton point-focusing solar modules

    NASA Technical Reports Server (NTRS)

    Roschke, E. J.; Wen, L.; Steele, H.; Elgabalawi, N.; Wang, J.

    1979-01-01

    A preliminary assessment of three conceptual point-focusing distributed solar modules is presented. The basic power conversion units consist of small Brayton or Rankine engines individually coupled to two-axis, tracking, point-focusing solar collectors. An array of such modules can be linked together, via electric transport, to form a small power station. Each module also can be utilized on a stand-alone basis, as an individual power source.

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

    SciTech Connect

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

    2011-04-10

    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.

  9. PHOBOS Exploration using Two Small Solar Electric Propulsion (SEP) Spacecraft

    NASA Technical Reports Server (NTRS)

    Lang, J. J.; Baker, J. D.; McElrath, T. P.; Piacentine, J. S.; Snyder, J. S.

    2012-01-01

    Phobos Surveyor Mission concept provides an innovative low cost, highly reliable approach to exploring the inner solar system 1/16/2013 3 Dual manifest launch. Use only flight proven, well characterize commercial off-the-shelf components. Flexible mission architecture allows for a slew of unique measurements.

  10. Solution-processed small-molecule solar cells: breaking the 10% power conversion efficiency.

    PubMed

    Liu, Yongsheng; Chen, Chun-Chao; Hong, Ziruo; Gao, Jing; Yang, Yang Michael; Zhou, Huanping; Dou, Letian; Li, Gang; Yang, Yang

    2013-01-01

    A two-dimensional conjugated small molecule (SMPV1) was designed and synthesized for high performance solution-processed organic solar cells. This study explores the photovoltaic properties of this molecule as a donor, with a fullerene derivative as an acceptor, using solution processing in single junction and double junction tandem solar cells. The single junction solar cells based on SMPV1 exhibited a certified power conversion efficiency of 8.02% under AM 1.5 G irradiation (100 mW cm(-2)). A homo-tandem solar cell based on SMPV1 was constructed with a novel interlayer (or tunnel junction) consisting of bilayer conjugated polyelectrolyte, demonstrating an unprecedented PCE of 10.1%. These results strongly suggest solution-processed small molecular materials are excellent candidates for organic solar cells. PMID:24285006

  11. Amplifying the Pacific climate system response to a small 11-year solar cycle forcing.

    PubMed

    Meehl, Gerald A; Arblaster, Julie M; Matthes, Katja; Sassi, Fabrizio; van Loon, Harry

    2009-08-28

    One of the mysteries regarding Earth's climate system response to variations in solar output is how the relatively small fluctuations of the 11-year solar cycle can produce the magnitude of the observed climate signals in the tropical Pacific associated with such solar variability. Two mechanisms, the top-down stratospheric response of ozone to fluctuations of shortwave solar forcing and the bottom-up coupled ocean-atmosphere surface response, are included in versions of three global climate models, with either mechanism acting alone or both acting together. We show that the two mechanisms act together to enhance the climatological off-equatorial tropical precipitation maxima in the Pacific, lower the eastern equatorial Pacific sea surface temperatures during peaks in the 11-year solar cycle, and reduce low-latitude clouds to amplify the solar forcing at the surface. PMID:19713524

  12. Siting Issues for Solar Thermal Power Plants with Small Community Applications

    NASA Technical Reports Server (NTRS)

    Holbeck, J. J.; Ireland, S. J.

    1978-01-01

    Technologies for solar thermal plants are being developed to provide energy alternatives for the future. Implementation of these plants requires consideration of siting issues as well as power system technology. While many conventional siting considerations are applicable, there is also a set of unique siting issues for solar thermal plants. Early experimental plants will have special siting considerations. The siting issues associated with small, dispersed solar thermal power plants in the 1 to 10 MWe power range for utility/small community applications are considered. Some specific requirements refer to the first 1 MWe engineering experiment for the Small Power Systems Applications (SPSA) Project. The siting issues themselves are discussed in three categories: (1) system resource requirements, (2) environmental effects on the system, and (3) potential impact of the plant on the environment. Within these categories, specific issues are discussed in a qualitative manner. Examples of limiting factors for some issues are taken from studies of other solar systems.

  13. The Small- and Medium-sized Enterprises Office (SME Office) at the European Medicines Agency.

    PubMed

    Carr, M

    2010-01-01

    On 15 December 2005, the European Medicines Agency (EMEA) launched an "SME Office" to provide financial and administrative assistance to micro-, small- and medium-sized enterprises (SMEs), with the aim of promoting innovation and the development of new human and veterinary medicinal products by SMEs. According to current EU definition of an SME, companies with fewer than 250 employees, and an annual turnover of not more than 50 million euro or an annual balance sheet total of not more than 43 million euro, are eligible for assistance from the SME Office. Incentives available from the EMEA for SMEs, include: Administrative and procedural assistance from SME Office within the Agency; Fee reductions (90%) for scientific advice and inspections; Fee exemptions for certain administrative services (excluding parallel distribution); Deferral of the fee payable for an application for marketing authorisation or related inspection until after the grant of the marketing authorisation; Conditional fee exemption where scientific advice followed and marketing application is unsuccessful; Assistance with translations of the product information documents. At the end of May 2009, more than 380 companies from 21 countries across the European Economic Area (EEA) had SME status assigned by the EMEA. The large majority of companies are developing medicinal products for human use, 16 are veterinary companies, 15 companies are developing products for both human and veterinary use and 38 are regulatory consultants. Since the SME initiative started the Agency has processed more than 130 requests for scientific advice with fee reductions totalling of 6.9 million euro. Regulatory assistance has been provided to more than 170 companies and 12 companies have benefited from the SME translation service. Stakeholders have acknowledged the significant role the SME Office now plays as a service provider. In the period between January 2006 and June 2009, 34 applications for marketing authorization

  14. Effects of solar radiation on the orbits of small particles

    NASA Technical Reports Server (NTRS)

    Lyttleton, R. A.

    1976-01-01

    A modification of the Robertson (1937) equations of particle motion in the presence of solar radiation is developed which allows for partial reflection of sunlight as a result of rapid and varying particle rotations caused by interaction with the solar wind. The coefficients and forces in earlier forms of the equations are compared with those in the present equations, and secular rates of change of particle orbital elements are determined. Orbital dimensions are calculated in terms of time, probable sizes and densities of meteoric and cometary particles are estimated, and times of infall to the sun are computed for a particle moving in an almost circular orbit and a particle moving in an elliptical orbit of high eccentricity. Changes in orbital elements are also determined for particles from a long-period sun-grazing comet. The results show that the time of infall to the sun from a highly eccentric orbit is substantially shorter than from a circular orbit with a radius equal to the mean distance in the eccentric orbit. The possibility is considered that the free orbital kinetic energy of particles drawn into the sun may be the energy source for the solar corona.

  15. Evaluation of Small Molecules as Front Cell Donor Materials for High-Efficiency Tandem Solar Cells.

    PubMed

    Zhang, Qian; Wan, Xiangjian; Liu, Feng; Kan, Bin; Li, Miaomiao; Feng, Huanran; Zhang, Hongtao; Russell, Thomas P; Chen, Yongsheng

    2016-08-01

    Three small molecules as front cell donors for tandem cells are thoroughly evaluated and a high power conversion efficiency of 11.47% is achieved, which demonstrates that the oligomer-like small molecules offer a good choice for high-performance tandem solar cells. PMID:27214707

  16. PHOBOS Exploration using Two Small Solar Electric Propulsion Spacecraft

    NASA Technical Reports Server (NTRS)

    Lang, Jared J.; Baker, John D.; Castillo-Rogez, Julie C.; McElrath, Timothy P.; Piacentine, Jamie S.; Snyder, J. Steve

    2012-01-01

    Primitive bodies are exciting targets for exploration as they provide clues to the early Solar system conditions and dynamical evolution. The two moons of Mars are particularly interesting because of their proximity to an astrobiological target. However, after four decades of Mars exploration, their origin and nature remain enigmatic. In addition, when considering the long-term objectives of the flexible path for the potential human exploration to Mars, Phobos and Deimos present exciting intermediate opportunities without the complication and expense of landing and ascending from the surface. As interest in these targets for the next frontier of human exploration grows, characterization missions designed specifically to examine surface properties, landing environments, and surface mapping prior to human exploration are becoming increasingly important. A precursor mission concept of this sort has been developed using two identical spacecraft designed from low cost, flight proven and certified off-the-shelf component and utilizing Solar Electric Propulsion (SEP) to orbit both targets as secondary payloads launched aboard any NASA or GTO launch. This precursor mission has the potential to address both precursor measurements that are strategic knowledge gaps and decadal science, including soil physical properties at the global and local (human) scale and the search for in situ resources.

  17. Structural considerations for solar installers : an approach for small, simplified solar installations or retrofits.

    SciTech Connect

    Richards, Elizabeth H.; Schindel, Kay; Bosiljevac, Tom; Dwyer, Stephen F.; Lindau, William; Harper, Alan

    2011-12-01

    Structural Considerations for Solar Installers provides a comprehensive outline of structural considerations associated with simplified solar installations and recommends a set of best practices installers can follow when assessing such considerations. Information in the manual comes from engineering and solar experts as well as case studies. The objectives of the manual are to ensure safety and structural durability for rooftop solar installations and to potentially accelerate the permitting process by identifying and remedying structural issues prior to installation. The purpose of this document is to provide tools and guidelines for installers to help ensure that residential photovoltaic (PV) power systems are properly specified and installed with respect to the continuing structural integrity of the building.

  18. Polarimetric Exploration of Solar System Small Bodies: Search for Habitability

    NASA Astrophysics Data System (ADS)

    Yanamandra-Fisher, Padma A.

    2015-08-01

    The overarching goals for the remote sensing and robotic exploration of our solar system and exoplanetary systems are: (1) understanding the formation of planetary systems and their diversity; and (2) search for habitability. These goals can be realized with the inclusion of spectrophotopolarimetry as a complementary approach to standard techniques of imaging and spectroscopy. Since all objects have unique polarimetric signatures, like fingerprints, much can be learned about the scattering object. Although polarization, in general, is elliptical by nature, special cases such as linear and circular polarimetric signatures provide insight into the various types of scattering media and are valuable tools to be developed. Additionally, spectral dependence of polarization is important to separate the macroscopic (bulk) properties of the scattering medium from the microscopic (particulate) properties of the scattering medium. The search for habitability can benefit from spectrophotopolarimetry. While linear polarization of reflected light by solar system objects (planetary atmospheres, satellites, rings systems, comets, asteroids, dust, etc.) provides insight into the scattering characteristics of aerosols and hazes in atmospheres and surficial properties of atmosphereless objects, circular polarization and related chirality) or handedness, a property of molecules that exhibit mirror-image symmetry, similar to right and left hands) can serve as diagnostic of biological activity. All known life forms on earth are chiral and pre-dominantly left-handed. However, many of these applications suffer from lack of detailed observations, instrumentation, dedicated missions and numerical/retrieval methods. I will present a review of the field, with advances made in instrumentation, measurements and applications to prospective missions.

  19. The Design of a Novel Survey for Small Objects in the Solar System

    SciTech Connect

    Alcock, C.; Chen, W.P.; de Pater, I.; Lee, T.; Lissauer, J.; Rice, J.; Liang, C.; Cook, K.; Marshall, S.; Akerlof, C.

    2000-08-21

    We evaluated several concepts for a new survey for small objects in the Solar System. We designed a highly novel survey for comets in the outer region of the Solar System, which exploits the occultations of relatively bright stars to infer the presence of otherwise extremely faint objects. The populations and distributions of these objects are not known; the uncertainties span orders of magnitude! These objects are important scientifically as probes of the primordial solar system, and programmatically now that major investments may be made in the possible mitigation of the hazard of asteroid or comet collisions with the Earth.

  20. Small Scale Solar Cooling Unit in Climate Conditions of Latvia: Environmental and Economical Aspects

    NASA Astrophysics Data System (ADS)

    Jaunzems, Dzintars; Veidenbergs, Ivars

    2010-01-01

    The paper contributes to the analyses from the environmental and economical point of view of small scale solar cooling system in climate conditions of Latvia. Cost analyses show that buildings with a higher cooling load and full load hours have lower costs. For high internal gains, cooling costs are around 1,7 €/kWh and 2,5 €/kWh for buildings with lower internal gains. Despite the fact that solar cooling systems have significant potential to reduce CO2 emissions due to a reduction of electricity consumption, the economic feasibility and attractiveness of solar cooling system is still low.

  1. Time development of a small solar X-ray burst

    NASA Technical Reports Server (NTRS)

    Cohen, G. G.; Kestenbaum, H. L.; Long, K. S.; Novick, R.; Weisskopf, M. C.; Wolff, R. S.

    1976-01-01

    The 5.1-7.2 A X-ray emission from the sun was studied via OSO-8 with a high-resolution PET crystal spectrometer during the week of 17 November 1975, when the sun was active. The combination of good temporal and spectral resolution permitted the analysis of the data with multithermal coronal models over the course of a small X-ray burst.

  2. Solar Energy: Progress and Design Concerns of Nanostructured Solar Energy Harvesting Devices (Small 19/2016).

    PubMed

    Leung, Siu-Fung; Zhang, Qianpeng; Tavakoli, Mohammad Mahdi; He, Jin; Mo, Xiaoliang; Fan, Zhiyong

    2016-05-01

    Nanoengineered materials and structures can harvest light efficiently for photovoltaic applications. Device structure design optimization and material property improvement are equally important for high performance. On page 2536, X. Mo, Z. Fan, and co-workers summarize the design guidelines of solar energy harvesting devices to assist with a better understanding of device physics. PMID:27167321

  3. Gamma-ray Albedo of Small Solar System Bodies

    SciTech Connect

    Moskalenko, I.V.

    2008-03-25

    We calculate the {gamma}-ray albedo flux from cosmic-ray (CR) interactions with the solid rock and ice in Main Belt asteroids and Kuiper Belt objects (KBOs) using the Moon as a template. We show that the {gamma}-ray albedo for the Main Belt and KBOs strongly depends on the small-body mass spectrum of each system and may be detectable by the forthcoming Gamma Ray Large Area Space Telescope (GLAST). If detected, it can be used to derive the mass spectrum of small bodies in the Main Belt and Kuiper Belt and to probe the spectrum of CR nuclei at close-to-interstellar conditions. The orbits of the Main Belt asteroids and KBOs are distributed near the ecliptic, which passes through the Galactic center and high Galactic latitudes. Therefore, the {gamma}-ray emission by the Main Belt and Kuiper Belt has to be taken into account when analyzing weak {gamma}-ray sources close to the ecliptic. The asteroid albedo spectrum also exhibits a 511 keV line due to secondary positrons annihilating in the rock. This may be an important and previously unrecognized celestial foreground for the INTErnational Gamma-Ray Astrophysics Laboratory (INTEGRAL) observations of the Galactic 511 keV line emission including the direction of the Galactic center. For details of our calculations and references see [1].

  4. International Energy Agency instrumented facilities survey for solar assisted low energy dwellings

    SciTech Connect

    1982-02-01

    Compiled are surveys outlining the instrumentation of 38 active and passive solar projects in 9 countries (Denmark, Italy, Japan, Netherlands, Sweden, Switzerland, United Kingdom, United States, and West Germany). After the surveys themselves are presented, the data are rearranged to compare answers from similar survey questions for each of the projects. These questions address building, solar system and instrumentation descriptions and meteorological, solar system and building system instrumentatation capabilities. (LEW)

  5. Small-molecule organic solar cells with improved stability

    NASA Astrophysics Data System (ADS)

    Song, Q. L.; Li, F. Y.; Yang, H.; Wu, H. R.; Wang, X. Z.; Zhou, W.; Zhao, J. M.; Ding, X. M.; Huang, C. H.; Hou, X. Y.

    2005-11-01

    A stable small-molecule organic photovoltaic device with structure of ITO⧹donor⧹acceptor⧹buffer⧹cathode is presented. A thin layer (˜60 Å) of tris-8-hydroxy-quinolinato aluminum (Alq 3) instead of bathocuproine (BCP) is adopted as the buffer of the device, resulting in 150 times longer lifetime. The power conversion efficiency of the device is 2.11% under 75 mW/cm 2 AM1.5G simulated illumination, and no perceptible efficiency degradation is observed for long-term storage of the device in vacuum or nitrogen-filled glove box. More effective blocking of Alq 3 than BCP against diffusion of cathode atoms and permeation of oxygen and/or water molecules is considered as the main reason for the improved performance of the new device.

  6. High Resolution Observations and Modeling of Small-Scale Solar Magnetic Elements

    NASA Technical Reports Server (NTRS)

    Berger, Thomas E.

    2001-01-01

    This research contract investigating the radiative transfer and dynamic physics of the smallest observable magnetic structures in the solar photosphere. Due to the lack of a high-resolution visible light satellite instrument for solar studies, all data were acquired using ground-based instrumentation. The primary goal of the investigation was to understand the formation and evolution of "G-band bright points" in relation to the associated magnetic elements. G-band bright points are small (on the order of 100 kin or less in diameter) bright signatures associated with magnetic flux elements in the photosphere. They are seen in the A2A-X2 4308 A molecular bandhead of the CH radical ill the solar spectrum and offer the highest spatial resolution and highest contrast "tracers" of small magnetic structure on the Sun.

  7. Magnetohydrodynamic Kink Waves in Nonuniform Solar Flux Tubes: Phase Mixing and Energy Cascade to Small Scales

    NASA Astrophysics Data System (ADS)

    Soler, Roberto; Terradas, Jaume

    2015-04-01

    Magnetohydrodynamic (MHD) kink waves are ubiquitously observed in the solar atmosphere. The propagation and damping of these waves may play relevant roles in the transport and dissipation of energy in the solar atmospheric medium. However, in the atmospheric plasma dissipation of transverse MHD wave energy by viscosity or resistivity needs very small spatial scales to be efficient. Here, we theoretically investigate the generation of small scales in nonuniform solar magnetic flux tubes due to phase mixing of MHD kink waves. We go beyond the usual approach based on the existence of a global quasi-mode that is damped in time due to resonant absorption. Instead, we use a modal expansion to express the MHD kink wave as a superposition of Alfvén continuum modes that are phase mixed as time evolves. The comparison of the two techniques evidences that the modal analysis is more physically transparent and describes both the damping of global kink motions and the building up of small scales due to phase mixing. In addition, we discuss that the processes of resonant absorption and phase mixing are closely linked. They represent two aspects of the same underlying physical mechanism: the energy cascade from large scales to small scales due to naturally occurring plasma and/or magnetic field inhomogeneities. This process may provide the necessary scenario for efficient dissipation of transverse MHD wave energy in the solar atmospheric plasma.

  8. DESIGN OF A SMALL – SCALE SOLAR CHIMNEY FOR SUSTAINABLE POWER

    EPA Science Inventory

    After several months of design and testing it has been determined that a small scale solar chimney can be built using nearly any local materials and simple hand tools without needing superior construction knowledge. The biggest obstacle to over come was the weather conditions....

  9. MAGNETIC RECONNECTION IN THE SOLAR WIND AT CURRENT SHEETS ASSOCIATED WITH EXTREMELY SMALL FIELD SHEAR ANGLES

    SciTech Connect

    Gosling, J. T.; Phan, T. D.

    2013-02-01

    Using Wind 3 s plasma and magnetic field data, we have identified nine reconnection exhausts within a solar wind disturbance on 1998 October 18-20 driven by a moderately fast interplanetary coronal mass ejection (ICME). Three of the exhausts within the ICME were associated with current sheets having local field shear angles, {theta}, ranging from 4 Degree-Sign to 9 Degree-Sign , the smallest reported values of {theta} yet associated with reconnection exhausts in a space plasma. They were observed in plasma characterized by extremely low (0.02-0.04) plasma {beta}, and very high (281-383 km s{sup -1}) Alfven speed, V{sub A}. Low {beta} allows reconnection to occur at small {theta} and high V{sub A} leads to exhaust jets that are fast enough relative to the surrounding solar wind to be readily identified. Very small-{theta} current sheets are common in the solar wind at 1 AU, but typically are not associated with particularly low plasma {beta} or high V{sub A}. On the other hand, small-{theta} current sheets should be common in the lower solar corona, a plasma regime of extremely low {beta} and extremely high V{sub A}. Our observations lend credence to models that predict that reconnection at small-{theta} current sheets is primarily responsible for coronal heating.

  10. Trapping of Solar Energetic Particles by Small-Scale Topology of Solar Wind Turbulence

    NASA Astrophysics Data System (ADS)

    Ruffolo, D.; Matthaeus, W. H.; Chuychai, P.

    2004-05-01

    The transport of energetic particles perpendicular to the mean magnetic field in space plasmas long has been viewed as a diffusive process. However, there is an apparent conflict between recent observations of solar energetic particles (SEP): 1) impulsive solar flares can exhibit ``dropouts" in which SEP intensity near Earth repeatedly disappears and reappears, indicating a filamentary distribution of SEPs and little diffusion across these boundaries. 2) Observations by the IMP-8 and Ulysses spacecraft, while they were on opposite sides of the Sun, showed similar time-intensity profiles for many SEP events, indicating rapid lateral diffusion of particles throughout the inner solar system within a few days. We explain these seemingly contradictory observations using a theoretical model, supported by computer simulations, in which many particles are temporarily trapped within topological structures in statistically homogeneous magnetic turbulence, and ultimately escape to diffuse at a much faster rate. This work was supported by the Thailand Research Fund, the Rachadapisek Sompoj Fund of Chulalongkorn University, and the NASA Sun-Earth Connections Theory Program (grant NAG5-8134).

  11. Solarization for nematode disinfestation of small volumes of soil.

    PubMed

    Giblin-Davis, R M; Verkade, S D

    1988-10-01

    Several polyethylene plastics were evaluated as potential materials for disinfesting small volumes of soil containing nematodes. Bursaphelenchus seani, cultured on the fungus Monilinia fructicola in petri dishes, was used to bioassay the survival and reproductive capability of nematodes buried 7.5 cm deep in Margate fine sand (soil moisture = 4.9%). The soil was exposed to sunlight for 6 days in May 1987. The highest mean temperatures recorded at 7.5 cm deep were 38 +/- 1 C, 43 +/- 1 C, 43 +/- 1 C, and 50 +/- 1 C for the no plastic, clear plastic, black plastic, and clear + black plastic treatments, respectively. The temperature in the clear + black plastic treatment exceeded 47 C for more than 2 hours on clear days. Nematode survival averaged 98 +/- 3%, 78 +/- 22%, 38 +/- 38%, and 0 +/- 0%, whereas the reproductive success of B. seani following treatment was 100, 100, 75, and 0% for the no plastic, clear plastic, black plastic, and clear + black plastic treatments, respectively. Bursaphelenchus seani in petri dishes and Belonolaimus longicaudatus and Hoplolaimus galeatus in soil died when exposed to 48 +/- 2 C for 2 hours. PMID:19290301

  12. 76 FR 71339 - Agency Information Collection Activities; Proposed Collection; Comment Request; State Small...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-17

    ... Business Stationary Source Technical and Environmental Compliance Assistance Programs (SBTCP) Annual... this action are the State Small Business Stationary Source Technical and Environmental Compliance Assistance Programs (SBTCP). Title: State Small Business Stationary Source Technical and...

  13. Solution processable organic polymers and small molecules for bulk-heterojunction solar cells: A review

    SciTech Connect

    Sharma, G. D.

    2011-10-20

    Solution processed bulk heterojunction (BHJ) organic solar cells (OSCs) have gained wide interest in past few years and are established as one of the leading next generation photovoltaic technologies for low cost power production. Power conversion efficiencies up to 6% and 6.5% have been reported in the literature for single layer and tandem solar cells, respectively using conjugated polymers. A recent record efficiency about 8.13% with active area of 1.13 cm{sup 2} has been reported. However Solution processable small molecules have been widely applied for photovoltaic (PV) devices in recent years because they show strong absorption properties, and they can be easily purified and deposited onto flexible substrates at low cost. Introducing different donor and acceptor groups to construct donor--acceptor (D--A) structure small molecules has proved to be an efficient way to improve the properties of organic solar cells (OSCs). The power conversion efficiency about 4.4 % has been reported for OSCs based on the small molecules. This review deals with the recent progress of solution processable D--A structure small molecules and discusses the key factors affecting the properties of OSCs based on D--A structure small molecules: sunlight absorption, charge transport and the energy level of the molecules.

  14. Small-scale solar radiation forecasting using ARMA and nonlinear autoregressive neural network models

    NASA Astrophysics Data System (ADS)

    Benmouiza, Khalil; Cheknane, Ali

    2016-05-01

    This paper aims to introduce an approach for multi-hour forecasting (915 h ahead) of hourly global horizontal solar radiation time series and forecasting of a small-scale solar radiation database (30- and 1-s scales) for a period of 1 day (47,000 s ahead) using commonly and available measured meteorological solar radiation. Three methods are considered in this study. First, autoregressive-moving-average (ARMA) model is used to predict future values of the global solar radiation time series. However, because of the non-stationarity of solar radiation time series, a phase of detrending is needed to stationarize the irradiation data; a 6-degree polynomial model is found to be the most stationary one. Secondly, due to the nonlinearity presented in solar radiation time series, a nonlinear autoregressive (NAR) neural network model is used for prediction purposes. Taking into account the advantages of both models, the goodness of ARMA for linear problems and NAR for nonlinear problems, a hybrid method combining ARMA and NAR is introduced to produce better results. The validation process for the site of Ghardaia in Algaria shows that the hybrid model gives a normalized root mean square error (NRMSE) equals to 0.2034 compared to a NRMSE equal to 0.2634 for NAR model and 0.3241 for ARMA model.

  15. New Directions in Solar System Small Body Science with the TMT

    NASA Astrophysics Data System (ADS)

    Meech, Karen J.

    2014-07-01

    One of the key goals of the Planetary Science Decadal Survey includes using primitive bodies to provide information about the epochs and processes in the early solar system and to understand the role that primitive bodies played in creating habitable worlds. Recent in-situ small body space missions (EPOXI, NEOWISE) have changed our understanding of the distribution of major volatiles in primitive bodies, in particular shedding light on the importance of CO2. At the same time there has been a revolution both in the dynamical models that describe how our solar system was assembled, and in the chemistry of the disk of material out of which the planetesimals formed. Observations of small bodies provide the links that will enable us to tie together the early solar system dynamical and chemical models. Because they are small and faint, we have been very limited in optical and near-IR spectroscopic follow up. I will present some of the recent breakthroughs, and what access to the TMT can contribute to understanding the early solar system, in combination with information that will be possible to get from JWST and ALMA.

  16. SUITS/SWUSV: a small-size mission to address solar spectral variability, space weather and solar-climate relations

    NASA Astrophysics Data System (ADS)

    Damé, Luc; Keckhut, Philippe; Hauchecorne, Alain; Meftah, Mustapha; Bekki, Slimane

    2016-07-01

    We present the SUITS/SWUSV microsatellite mission investigation: "Solar Ultraviolet Influence on Troposphere/Stratosphere, a Space Weather & Ultraviolet Solar Variability" mission. SUITS/SWUSV was developed to determine the origins of the Sun's activity, understand the flaring process (high energy flare characterization) and onset of CMEs (forecasting). Another major objective is to determine the dynamics and coupling of Earth's atmosphere and its response to solar variability (in particular UV) and terrestrial inputs. It therefore includes the prediction and detection of major eruptions and coronal mass ejections (Lyman-Alpha and Herzberg continuum imaging) the solar forcing on the climate through radiation and their interactions with the local stratosphere (UV spectral irradiance measures from 170 to 400 nm). The mission is proposed on a sun-synchronous polar orbit 18h-6h (for almost constant observing) and proposes a 7 instruments model payload of 65 kg - 65 W with: SUAVE (Solar Ultraviolet Advanced Variability Experiment), an optimized telescope for FUV (Lyman-Alpha) and MUV (200-220 nm Herzberg continuum) imaging (sources of variability); SOLSIM (Solar Spectral Irradiance Monitor), a spectrometer with 0.65 nm spectral resolution from 170 to 340 nm; SUPR (Solar Ultraviolet Passband Radiometers), with UV filter radiometers at Lyman-Alpha, Herzberg, MgII index, CN bandhead and UV bands coverage up to 400 nm; HEBS (High Energy Burst Spectrometers), a large energy coverage (a few tens of keV to a few hundreds of MeV) instrument to characterize large flares; EPT-HET (Electron-Proton Telescope - High Energy Telescope), measuring electrons, protons, and heavy ions over a large energy range; ERBO (Earth Radiative Budget and Ozone) NADIR oriented; and a vector magnetometer. Complete accommodation of the payload has been performed on a PROBA type platform very nicely. Heritage is important both for instruments (SODISM and PREMOS on PICARD, LYRA on PROBA-2, SOLSPEC on ISS

  17. Coupled orbit-attitude dynamics and relative state estimation of spacecraft near small Solar System bodies

    NASA Astrophysics Data System (ADS)

    Misra, Gaurav; Izadi, Maziar; Sanyal, Amit; Scheeres, Daniel

    2016-04-01

    The effects of dynamical coupling between the rotational (attitude) and translational (orbital) motion of spacecraft near small Solar System bodies is investigated. This coupling arises due to the weak gravity of these bodies, as well as solar radiation pressure. The traditional approach assumes a point-mass spacecraft model to describe the translational motion of the spacecraft, while the attitude motion is considered to be completely decoupled from the translational motion. The model used here to describe the rigid-body spacecraft dynamics includes the non-uniform rotating gravity field of the small body up to second degree and order along with the attitude dependent terms, solar tide, and solar radiation pressure. This model shows that the second degree and order gravity terms due to the small body affect the dynamics of the spacecraft to the same extent as the orbit-attitude coupling due to the primary gravity (zeroth order) term. Variational integrators are used to simulate the dynamics of both the rigid spacecraft and the point mass. The small bodies considered here are modeled after Near-Earth Objects (NEO) 101955 Bennu, and 25143 Itokawa, and are assumed to be triaxial ellipsoids with uniform density. Differences in the numerically obtained trajectories of a rigid spacecraft and a point mass are then compared, to illustrate the impact of the orbit-attitude coupling on spacecraft dynamics in proximity of small bodies. Possible implications on the performance of model-based spacecraft control and on the station-keeping budget, if the orbit-attitude coupling is not accounted for in the model of the dynamics, are also discussed. An almost globally asymptotically stable motion estimation scheme based solely on visual/optical feedback that estimates the relative motion of the asteroid with respect to the spacecraft is also obtained. This estimation scheme does not require a model of the dynamics of the asteroid, which makes it perfectly suited for asteroids whose

  18. Designing a Small-Sized Engineering Model of Solar EUV Telescopr for a Korean Satellite

    NASA Astrophysics Data System (ADS)

    Han, Jung-Hoon; Jang, Min-Hwan; Kim, Sang-Joon

    2001-11-01

    For the research of solar EUV (extreme ultraviolet) radiation, we have designed a small-sized engineering model of solar EUV telescope, which is suitable for a Korean satellite. The EUV solar telescope was designed to observe the sun at 584.3Å (He¥°) and 629.7Å (O¥´). The optical system is an f/8 Ritchey-Chrètien, and the effective diameter and focal length are 80§® and 640§®, respectively. The He¥°and O¥´ filters are loaded in a filter wheel. In the detection part, the MCP (MicroChannel Plate) type is Z-stack, and the channel-to-diameter ratio is 40:1. MCP and CCD are connected by fiber optic taper. A commercial optical design software is used for the analysis of the optical system design.

  19. Small Scale Chromospheric Dynamics Detected With The New Solar Telescope In Big Bear

    NASA Astrophysics Data System (ADS)

    Yurchyshyn, Vasyl B.

    2010-05-01

    High resolution observations of quiet Sun areas obtained with the New Solar Telescope (NST) in Big Bear Solar Observatory revealed surprisingly storming small-scale chromospheric dynamics. We thus discovered tiny chromospheric jets originating in the ubiquitous lanes that surround individual granules characterizing the solar surface. These jets do not appear to be exclusively associated with photospheric bright points and/or vertices of the intergranular lanes. They seem to have sufficient energy to resolve the mystery of why the overlying chromosphere is hotter than the photosphere. We will further address the nature of these chromospheric jets and their relationship to ambient magnetic fields by combining high resolution data from NST instruments and Hinode observatory.

  20. Appropriate technology for rural India - solar decontamination of water for emergency settings and small communities.

    PubMed

    Kang, Gagandeep; Roy, Sheela; Balraj, Vinohar

    2006-09-01

    A commercial solar water heating system was evaluated for its effectiveness in decontaminating drinking water with a view to use in emergency situations. A total of 18 seeding experiments carried out over 6 months with 10(5) to 10(7)Escherichia coli/ml showed that the solar heater produced 125 l of bacteriologically safe water in 4 h when the ambient temperature was above 30 degrees C, with a holding time of at least 2 h. The solar water heating system is inexpensive, easy to transport and set up and could provide safer drinking water for 50 people a day. It would be effective in the decrease and prevention of waterborne disease in emergency situations, and is appropriate for use in small communities. PMID:16289648

  1. Efficient polymer solar cells employing a non-conjugated small-molecule electrolyte

    NASA Astrophysics Data System (ADS)

    Ouyang, Xinhua; Peng, Ruixiang; Ai, Ling; Zhang, Xingye; Ge, Ziyi

    2015-08-01

    Polymer solar cells have drawn a great deal of attention due to the attractiveness of their use in renewable energy sources that are potentially lightweight and low in cost. Recently, numerous significant research efforts have resulted in polymer solar cells with power conversion efficiencies in excess of 9% (ref. 1). Nevertheless, further improvements in performance are sought for commercial applications. Here, we report polymer solar cells with a power conversion efficiency of 10.02% that employ a non-conjugated small-molecule electrolyte as an interlayer. The material offers good contact for photogenerated charge carrier collection and allows optimum photon harvesting in the device. Furthermore, the enhanced performance is attributed to improved electron mobility, enhanced active-layer absorption and properly active-layer microstructures with optimal horizontal phase separation and vertical phase gradation. Our discovery opens a new avenue for single-junction devices by fully exploiting the potential of various material systems with efficiency over 10%.

  2. Turbulent transport of Small-scale magnetic flux elements on Solar Photosphere

    NASA Astrophysics Data System (ADS)

    Agrawal, Piyush; Rempel, Matthias; Bellot Rubio, Luis; Rast, Mark

    2016-05-01

    We study the transport of small-scale magnetic elements on the solar photosphere using both observations and simulations. Observational data was obtained from Hinode - Solar Optical Telescope (SOT/SP) instrument and simulations from MURaM code. The magnetic flux elements were tracked in both data sets and statistics were obtained. We compute the probability density of the Eulerian distances traveled by the flux elements along Lagrangian trajectories. For a two-dimensional random walk process this distribution should be Rayleigh. Preliminary results show that the measured probability distribution in both the observed and simulated data approximates a random walk, on time scale close to the lifetime of granules, but deviates from it for longer times. This implies that diffusion may not be an appropriate framework for transport in the solar photosphere. We explore the roles of flux cancelation and element trapping in producing this result. Work is ongoing.

  3. Small-scale Structuring of Ellerman Bombs at the Solar Limb

    NASA Astrophysics Data System (ADS)

    Nelson, C. J.; Scullion, E. M.; Doyle, J. G.; Freij, N.; Erdélyi, R.

    2015-01-01

    Ellerman bombs (EBs) have been widely studied in recent years due to their dynamic, explosive nature and apparent links to the underlying photospheric magnetic field implying that they may be formed by magnetic reconnection in the photosphere. Despite a plethora of researches discussing the morphologies of EBs, there has been a limited investigation of how these events appear at the limb, specifically, whether they manifest as vertical extensions away from the disk. In this article, we make use of high-resolution, high-cadence observations of an Active Region at the solar limb, collected by the CRisp Imaging SpectroPolarimeter (CRISP) instrument, to identify EBs and infer their physical properties. The upper atmosphere is also probed using the Solar Dynamic Observatory's Atmospheric Imaging Assembly (SDO/AIA). We analyze 22 EB events evident within these data, finding that 20 appear to follow a parabolic path away from the solar surface at an average speed of 9 km s-1, extending away from their source by 580 km, before retreating back at a similar speed. These results show strong evidence of vertical motions associated with EBs, possibly explaining the dynamical "flaring" (changing in area and intensity) observed in on-disk events. Two in-depth case studies are also presented that highlight the unique dynamical nature of EBs within the lower solar atmosphere. The viewing angle of these observations allows for a direct linkage between these EBs and other small-scale events in the Hα line wings, including a potential flux emergence scenario. The findings presented here suggest that EBs could have a wider-reaching influence on the solar atmosphere than previously thought, as we reveal a direct linkage between EBs and an emerging small-scale loop, and other near-by small-scale explosive events. However, as previous research found, these extensions do not appear to impact upon the Hα line core, and are not observed by the SDO/AIA EUV filters.

  4. SMALL-SCALE STRUCTURING OF ELLERMAN BOMBS AT THE SOLAR LIMB

    SciTech Connect

    Nelson, C. J.; Doyle, J. G.; Scullion, E. M.; Freij, N.; Erdélyi, R.

    2015-01-01

    Ellerman bombs (EBs) have been widely studied in recent years due to their dynamic, explosive nature and apparent links to the underlying photospheric magnetic field implying that they may be formed by magnetic reconnection in the photosphere. Despite a plethora of researches discussing the morphologies of EBs, there has been a limited investigation of how these events appear at the limb, specifically, whether they manifest as vertical extensions away from the disk. In this article, we make use of high-resolution, high-cadence observations of an Active Region at the solar limb, collected by the CRisp Imaging SpectroPolarimeter (CRISP) instrument, to identify EBs and infer their physical properties. The upper atmosphere is also probed using the Solar Dynamic Observatory's Atmospheric Imaging Assembly (SDO/AIA). We analyze 22 EB events evident within these data, finding that 20 appear to follow a parabolic path away from the solar surface at an average speed of 9 km s{sup –1}, extending away from their source by 580 km, before retreating back at a similar speed. These results show strong evidence of vertical motions associated with EBs, possibly explaining the dynamical ''flaring'' (changing in area and intensity) observed in on-disk events. Two in-depth case studies are also presented that highlight the unique dynamical nature of EBs within the lower solar atmosphere. The viewing angle of these observations allows for a direct linkage between these EBs and other small-scale events in the Hα line wings, including a potential flux emergence scenario. The findings presented here suggest that EBs could have a wider-reaching influence on the solar atmosphere than previously thought, as we reveal a direct linkage between EBs and an emerging small-scale loop, and other near-by small-scale explosive events. However, as previous research found, these extensions do not appear to impact upon the Hα line core, and are not observed by the SDO/AIA EUV filters.

  5. Solar photovoltaic applications seminar: design, installation and operation of small, stand-alone photovoltaic power systems

    SciTech Connect

    Not Available

    1980-07-01

    This seminar material was developed primarily to provide solar photovoltaic (PV) applied engineering technology to the Federal community. An introduction to photoconductivity, semiconductors, and solar photovoltaic cells is included along with a demonstration of specific applications and application identification. The seminar details general systems design and incorporates most known information from industry, academia, and Government concerning small solar cell power system design engineering, presented in a practical and applied manner. Solar PV power system applications involve classical direct electrical energy conversion and electric power system analysis and synthesis. Presentations and examples involve a variety of disciplines including structural analysis, electric power and load analysis, reliability, sizing and optimization; and, installation, operation and maintenance. Four specific system designs are demonstrated: water pumping, domestic uses, navigational and aircraft aids, and telecommunications. All of the applications discussed are for small power requirement (under 2 kilowatts), stand-alone systems to be used in remote locations. Also presented are practical lessons gained from currently installed and operating systems, problems at sites and their resolution, a logical progression through each major phase of system acquisition, as well as thorough design reviews for each application.

  6. Lightweight Integrated Solar Array (LISA): Providing Higher Power to Small Spacecraft

    NASA Technical Reports Server (NTRS)

    Johnson, Les; Carr, John; Fabisinski, Leo; Lockett, Tiffany Russell

    2015-01-01

    Affordable and convenient access to electrical power is essential for all spacecraft and is a critical design driver for the next generation of smallsats, including CubeSats, which are currently extremely power limited. The Lightweight Integrated Solar Array (LISA), a concept designed, prototyped, and tested at the NASA Marshall Space Flight Center (MSFC) in Huntsville, Alabama provides an affordable, lightweight, scalable, and easily manufactured approach for power generation in space. This flexible technology has many wide-ranging applications from serving small satellites to providing abundant power to large spacecraft in GEO and beyond. By using very thin, ultraflexible solar arrays adhered to an inflatable or deployable structure, a large area (and thus large amount of power) can be folded and packaged into a relatively small volume.

  7. Prevalence of small-scale jets from the networks of the solar transition region and chromosphere.

    PubMed

    Tian, H; DeLuca, E E; Cranmer, S R; De Pontieu, B; Peter, H; Martínez-Sykora, J; Golub, L; McKillop, S; Reeves, K K; Miralles, M P; McCauley, P; Saar, S; Testa, P; Weber, M; Murphy, N; Lemen, J; Title, A; Boerner, P; Hurlburt, N; Tarbell, T D; Wuelser, J P; Kleint, L; Kankelborg, C; Jaeggli, S; Carlsson, M; Hansteen, V; McIntosh, S W

    2014-10-17

    As the interface between the Sun's photosphere and corona, the chromosphere and transition region play a key role in the formation and acceleration of the solar wind. Observations from the Interface Region Imaging Spectrograph reveal the prevalence of intermittent small-scale jets with speeds of 80 to 250 kilometers per second from the narrow bright network lanes of this interface region. These jets have lifetimes of 20 to 80 seconds and widths of ≤300 kilometers. They originate from small-scale bright regions, often preceded by footpoint brightenings and accompanied by transverse waves with amplitudes of ~20 kilometers per second. Many jets reach temperatures of at least ~10(5) kelvin and constitute an important element of the transition region structures. They are likely an intermittent but persistent source of mass and energy for the solar wind. PMID:25324395

  8. Radiative 3D MHD simulations of the spontaneous small-scale eruptions in the solar atmosphere

    NASA Astrophysics Data System (ADS)

    Kitiashvili, Irina N.

    2015-08-01

    Studying non-linear turbulent dynamics of the solar atmosphere is important for understanding mechanism of the solar and stellar brightness variations. High-resolution observations of the quiet Sun reveal ubiquitous distributions of high-speed jets, which are transport mass and energy into the solar corona and feeding the solar wind. However, the origin of these eruption events is still unknown. Using 3D realistic MHD numerical simulations we find that small-scale eruptions are produced by ubiquitous magnetized vortex tubes generated by the Sun's turbulent convection in subsurface layers. The swirling vortex tubes (resembling tornadoes) penetrate into the solar atmosphere, capture and stretch background magnetic field, and push the surrounding material up, generating shocks. Our simulations reveal complicated high-speed flow patterns and thermodynamic and magnetic structure in the erupting vortex tubes and shows that the eruptions are initiated in the subsurface layers and are driven by high-pressure gradients in the subphotosphere and photosphere and by the Lorentz force in the higher atmosphere layers. I will discuss about properties of these eruptions, their effects on brightness and spectral variations and comparison with observations.

  9. Properties of small scale fluctuations in turbulent flow of solar wind and magnetosheath

    NASA Astrophysics Data System (ADS)

    Riazantseva, Maria; Zastenker, Georgy; Nemecek, Zdenek; Safrankova, Jana; Prech, Lubomir; Budaev, Vyacheslav; Liudmila, Rakhmanova; Pavlos, George

    Magnetosphere of the Earth is formed under the influence of turbulent solar wind flow. Amplitudes of turbulent fluctuations of particle flux and magnetic field are considerably increased in the Earth's magnetosheath. We present the latest results of the studies of properties of small scale fluctuations in turbulent flow of solar wind and magnetosheath using extremely high resolution (up to 0.03 s) of BMSW device operating on SPECTR-R mission. The spectra of plasma fluctuations on the scales 0.03-100 s scales are systematically analyzed. The existence of the break frequency in spectra of fluctuations of the solar wind and magnetosheath plasma parameters is demonstrated. Variations of spectra slopes before and after break, and of the frequency of the break are analyzed for different solar wind conditions. The differences of the parameters of the spectra of ion flux value and direction are discussed. The properties of non Gaussian probability distribution functions (PDF) of fluctuations of plasma parameters on scales less than 10 s are observed. The characteristics of structure functions and their scaling are determined. It’s shown that the filament structures in the turbulent solar wind flows observed as a rule. The possibility to describe PDF’s by Tsalis statistics is discussed. All statistical results demonstrate the high level of intermittency on discussed scales.

  10. COSPAR Workshop on Planetary Protection for Outer Planet Satellites and Small Solar System Bodies

    NASA Astrophysics Data System (ADS)

    Ehrenfreund, Pascale; Rummel, John; Peter, Nicolas

    The COSPAR Panel on Planetary Protection (PPP) held a COSPAR Workshop to consider the planetary protection status of Outer Planet satellites and other small Solar System bodies, and the measures that should be taken (or not) to protect them from Earth-sourced biological and organic contamination. The starting point for the 2009 COSPAR Planetary Protection Workshop at the European Space Policy Institute (ESPI) in Vienna was to consider the prob-abilistic approach in place in the COSPAR Planetary Protection Policy for the protection of Europa. The participants of this Workshop discussed the application of the approach and the associated formulation and parameterization to other Outer Planet satellites and small bodies. This application, as well as other considerations brought forward by the group, resulted in a full consideration of the various Outer Planet satellites and other Small Solar system bodies. The report on this workshop contains recommendations for the categorization of missions that may encounter or closely study the Outer Solar System in the future. Subsequently, the Work-shop also reviewed the consequences of applying these recommendations to the Outer Planets Flagship missions that have been under consideration by ESA, NASA, and their cooperating partners. A further workshop, concentrating on the specifics of Titan and Ganymede missions, was proposed by the group.

  11. Lightweight Inflatable Solar Array: Providing a Flexible, Efficient Solution to Space Power Systems for Small Spacecraft

    NASA Technical Reports Server (NTRS)

    Johnson, Len; Fabisinski, Leo; Cunningham, Karen; Justice, Stefanie

    2014-01-01

    Affordable and convenient access to electrical power is critical to consumers, spacecraft, military and other applications alike. In the aerospace industry, an increased emphasis on small satellite flights and a move toward CubeSat and NanoSat technologies, the need for systems that could package into a small stowage volume while still being able to power robust space missions has become more critical. As a result, the Marshall Space Flight Center's Advanced Concepts Office identified a need for more efficient, affordable, and smaller space power systems to trade in performing design and feasibility studies. The Lightweight Inflatable Solar Array (LISA), a concept designed, prototyped, and tested at the NASA Marshall Space Flight Center (MSFC) in Huntsville, Alabama provides an affordable, lightweight, scalable, and easily manufactured approach for power generation in space or on Earth. This flexible technology has many wide-ranging applications from serving small satellites to soldiers in the field. By using very thin, ultraflexible solar arrays adhered to an inflatable structure, a large area (and thus large amount of power) can be folded and packaged into a relatively small volume (shown in artist rendering in Figure 1 below). The proposed presentation will provide an overview of the progress to date on the LISA project as well as a look at its potential, with continued development, to revolutionize small spacecraft and portable terrestrial power systems.

  12. The Impacts of Different Expansion Modes on Performance of Small Solar Energy Firms: Perspectives of Absorptive Capacity

    PubMed Central

    Chen, Hsing Hung; Shen, Tao; Xu, Xin-long; Ma, Chao

    2013-01-01

    The characteristics of firm's expansion by differentiated products and diversified products are quite different. However, the study employing absorptive capacity to examine the impacts of different modes of expansion on performance of small solar energy firms has never been discussed before. Then, a conceptual model to analyze the tension between strategies and corporate performance is proposed to filling the vacancy. After practical investigation, the results show that stronger organizational institutions help small solar energy firms expanded by differentiated products increase consistency between strategies and corporate performance; oppositely, stronger working attitudes with weak management controls help small solar energy firms expanded by diversified products reduce variance between strategies and corporate performance. PMID:24453837

  13. Multiscale Molecular Simulation of Solution Processing of SMDPPEH: PCBM Small-Molecule Organic Solar Cells.

    PubMed

    Lee, Cheng-Kuang; Pao, Chun-Wei

    2016-08-17

    Solution-processed small-molecule organic solar cells are a promising renewable energy source because of their low production cost, mechanical flexibility, and light weight relative to their pure inorganic counterparts. In this work, we developed a coarse-grained (CG) Gay-Berne ellipsoid molecular simulation model based on atomistic trajectories from all-atom molecular dynamics simulations of smaller system sizes to systematically study the nanomorphology of the SMDPPEH/PCBM/solvent ternary blend during solution processing, including the blade-coating process by applying external shear to the solution. With the significantly reduced overall system degrees of freedom and computational acceleration from GPU, we were able to go well beyond the limitation of conventional all-atom molecular simulations with a system size on the order of hundreds of nanometers with mesoscale molecular detail. Our simulations indicate that, similar to polymer solar cells, the optimal blending ratio in small-molecule organic solar cells must provide the highest specific interfacial area for efficient exciton dissociation, while retaining balanced hole/electron transport pathway percolation. We also reveal that blade-coating processes have a significant impact on nanomorphology. For given donor/acceptor blending ratios, applying an external shear force can effectively promote donor/acceptor phase segregation and stacking in the SMDPPEH domains. The present study demonstrated the capability of an ellipsoid-based coarse-grained model for studying the nanomorphology evolution of small-molecule organic solar cells during solution processing/blade-coating and provided links between fabrication protocols and device nanomorphologies. PMID:27435212

  14. Phase 1 of the First Solar Small Power System Experiment (experimental System No. 1). Volume 2: Appendix A - D

    NASA Technical Reports Server (NTRS)

    Clark, T. B. (Editor)

    1979-01-01

    Recommended conceptual designs for the baseline solar concentrator and electrical subsystems are defined, and trade offs that were evaluated to arrive at the baseline systems are presented. In addition, the developmental history of the Stirling engine is reviewed, the U4 configuration is described, and a Stirling engine heat pipe system is evaluated for solar application where sodium vapor is used as the heat source. An organic Rankine cycle engine is also evaluated for solar small power system application.

  15. A RECIPROCATING SOLAR HEATED ENGINE UTILIZING DIRECT ABSORPTION BY SMALL PARTICLES

    SciTech Connect

    Hull, Patricia G.; Hunt, Arlon J.

    1981-05-01

    A new type of reciprocating solar engine utilizing small particles to absorb concentrated sunlight directly within the cylinders is described. The engine operates by drawing an air particle mixture into the cylinder, compressing the mixture, opening an optical valve to allow concentrated sunlight to enter through a window in the top of the cylinder head, absorbing the solar flux with the particles, and converting the heat trapped by the air-particle mixture into mechanical energy with the downward stroke of piston. It differs from other gas driven heat engines using solar energy in three main respects. First, the radiant flux is deposited directly in the working fluid inside the cylinder; second, the heat is directed to the appropriate cylinder by controlling the solar flux by an optical system; third, the gas is heated during a significant portion of the compression stroke. The thermodynamic efficiency of the engine is calculated using an analytical model and is compared to several other engine cycles of interest.

  16. Solar Collector With Image-Forming Mirror Cavity to Irradiate Small Central Volume

    NASA Technical Reports Server (NTRS)

    Buchele, Don; Castle, Charles; Bonoetti, Joseph A.

    2001-01-01

    A unique solar thermal chamber has been designed and fabricated to produce the maximum concentration of solar energy and higher temperature possible. Its primary purpose was for solar plasma propulsion experiments and related material specimen testing above 3000 K. The design not only maximized solar concentration, but also, minimized infrared heat loss. This paper provides the underlying theory and operation of the chamber and initial optical correlation to the actual fabricated hardware. The chamber is placed at the focal point of an existing primary concentrator with a 2.74 m (9 ft) focal length. A quartz lens focuses a small sun image at the inlet hole of the mirrored cavity. The lens focuses two image planes at prescribed positions; the sun at the cavity's entrance hole and the primary concentrator at the junction plane of two surfaces that form the cavity chamber. The back half is an ellipsoid reflector that produces a 1.27 cm diameter final sun image. The image is "suspended in space," 7.1 cm away from the nearest cavity surface, to minimize thermal and contaminate damage to the mirror surfaces. A hemisphere mirror makes up the front chamber and has its center of curvature at the target image, where rays leaving the target are reflected back upon themselves, minimizing radiation losses.

  17. Analysis of electroluminescence images in small-area circular CdTe solar cells

    NASA Astrophysics Data System (ADS)

    Bokalič, Matevž; Raguse, John; Sites, James R.; Topič, Marko

    2013-09-01

    The electroluminescence (EL) imaging process of small area solar cells is investigated in detail to expose optical and electrical effects that influence image acquisition and corrupt the acquired image. An approach to correct the measured EL images and to extract the exact EL radiation as emitted from the photovoltaic device is presented. EL images of circular cadmium telluride (CdTe) solar cells are obtained under different conditions. The power-law relationship between forward injection current and EL emission and a negative temperature coefficient of EL radiation are observed. The distributed Simulation Program with Integrated Circuit Emphasis (SPICE®) model of the circular CdTe solar cell is used to simulate the dark J-V curve and current distribution under the conditions used during EL measurements. Simulation results are presented as circularly averaged EL intensity profiles, which clearly show that the ratio between resistive parameters determines the current distribution in thin-film solar cells. The exact resistance values for front and back contact layers and for CdTe bulk layer are determined at different temperatures, and a negative temperature coefficient for the CdTe bulk resistance is observed.

  18. High-efficiency polymer solar cells with small photon energy loss

    PubMed Central

    Kawashima, Kazuaki; Tamai, Yasunari; Ohkita, Hideo; Osaka, Itaru; Takimiya, Kazuo

    2015-01-01

    A crucial issue facing polymer-based solar cells is how to manage the energetics of the polymer/fullerene blends to maximize short-circuit current density and open-circuit voltage at the same time and thus the power conversion efficiency. Here we demonstrate that the use of a naphthobisoxadiazole-based polymer with a narrow bandgap of 1.52 eV leads to high open-circuit voltages of approximately 1 V and high-power conversion efficiencies of ∼9% in solar cells, resulting in photon energy loss as small as ∼0.5 eV, which is much smaller than that of typical polymer systems (0.7–1.0 eV). This is ascribed to the high external quantum efficiency for the systems with a very small energy offset for charge separation. These unconventional features of the present polymer system will inspire the field of polymer-based solar cells towards further improvement of power conversion efficiencies with both high short-circuit current density and open-circuit voltage. PMID:26626042

  19. Lightweight Innovative Solar Array (LISA): Providing Higher Power to Small Spacecraft

    NASA Technical Reports Server (NTRS)

    Johnson, Les; Carr, John; Fabisinski, Leo; Russell,Tiffany; Smith, Leigh

    2015-01-01

    Affordable and convenient access to electrical power is essential for all spacecraft and is a critical design driver for the next generation of smallsats, including cubesats, which are currently extremely power limited. The Lightweight Innovative Solar Array (LISA), a concept designed, prototyped, and tested at the NASA Marshall Space Flight Center (MSFC) in Huntsville, Alabama provides an affordable, lightweight, scalable, and easily manufactured approach for power generation in space. This flexible technology has many wide-ranging applications from serving small satellites to providing abundant power to large spacecraft in GEO and beyond. By using very thin, ultra-flexible solar arrays adhered to an inflatable structure, a large area (and thus large amount of power) can be folded and packaged into a relatively small volume. The LISA array comprises a launch-stowed, orbit-deployed structure on which lightweight photovoltaic devices and, potentially, transceiver elements are embedded. The system will provide a 2.5 to 5 fold increase in specific power generation (Watts/kilogram) coupled with a >2x enhancement of stowed volume (Watts/cubic-meter) and a decrease in cost (dollars/Watt) when compared to state-of-the-art solar arrays.

  20. A Jovian Small Orbiter for Magnetospheric and Auroral Studies with the Solar-Sail Project

    NASA Astrophysics Data System (ADS)

    Kasaba, Y.; Takashima, T.; Misawa, H.

    2009-06-01

    The Solar-Sail Project has been investigated by JAXA as an engineering mission with a small orbiter into the Jovian orbit. This paper summarizes the basic design of this project and possible Jovian system studies by this opportunity. The large-scale Jovian mission has been discussed as a long future plan since the 1970s, when the investigation of the future planetary exploration program started in Japan. The largest planet and its complex planetary system would be studied by several main objectives: (1) The structure of a gas planet: the internal and atmospheric structures of a gas planet which could not be a star. (2) The Jovian-type magnetosphere: the structure and processes of the largest and strongest magnetosphere in the solar system. (3) The structure, composition, and evolution of Jupiter and its satellite system. The small Jovian orbiter accompanied with the Solar-Sail Project will try to establish the technical feasibility of such future outer planet missions in Japan. The main objective is the second target, the Jovian magnetospheric and auroral studies with its limited payload resources.

  1. High-efficiency polymer solar cells with small photon energy loss

    NASA Astrophysics Data System (ADS)

    Kawashima, Kazuaki; Tamai, Yasunari; Ohkita, Hideo; Osaka, Itaru; Takimiya, Kazuo

    2015-12-01

    A crucial issue facing polymer-based solar cells is how to manage the energetics of the polymer/fullerene blends to maximize short-circuit current density and open-circuit voltage at the same time and thus the power conversion efficiency. Here we demonstrate that the use of a naphthobisoxadiazole-based polymer with a narrow bandgap of 1.52 eV leads to high open-circuit voltages of approximately 1 V and high-power conversion efficiencies of ~9% in solar cells, resulting in photon energy loss as small as ~0.5 eV, which is much smaller than that of typical polymer systems (0.7-1.0 eV). This is ascribed to the high external quantum efficiency for the systems with a very small energy offset for charge separation. These unconventional features of the present polymer system will inspire the field of polymer-based solar cells towards further improvement of power conversion efficiencies with both high short-circuit current density and open-circuit voltage.

  2. 3D magnetic field configuration of small-scale reconnection events in the solar plasma atmosphere

    SciTech Connect

    Shimizu, T.

    2015-10-15

    The outer solar atmosphere, i.e., the corona and the chromosphere, is replete with small energy-release events, which are accompanied by transient brightening and jet-like ejections. These events are considered to be magnetic reconnection events in the solar plasma, and their dynamics have been studied using recent advanced observations from the Hinode spacecraft and other observatories in space and on the ground. These events occur at different locations in the solar atmosphere and vary in their morphology and amount of the released energy. The magnetic field configurations of these reconnection events are inferred based on observations of magnetic fields at the photospheric level. Observations suggest that these magnetic configurations can be classified into two groups. In the first group, two anti-parallel magnetic fields reconnect to each other, yielding a 2D emerging flux configuration. In the second group, helical or twisted magnetic flux tubes are parallel or at a relative angle to each other. Reconnection can occur only between anti-parallel components of the magnetic flux tubes and may be referred to as component reconnection. The latter configuration type may be more important for the larger class of small-scale reconnection events. The two types of magnetic configurations can be compared to counter-helicity and co-helicity configurations, respectively, in laboratory plasma collision experiments.

  3. High-efficiency polymer solar cells with small photon energy loss.

    PubMed

    Kawashima, Kazuaki; Tamai, Yasunari; Ohkita, Hideo; Osaka, Itaru; Takimiya, Kazuo

    2015-01-01

    A crucial issue facing polymer-based solar cells is how to manage the energetics of the polymer/fullerene blends to maximize short-circuit current density and open-circuit voltage at the same time and thus the power conversion efficiency. Here we demonstrate that the use of a naphthobisoxadiazole-based polymer with a narrow bandgap of 1.52 eV leads to high open-circuit voltages of approximately 1 V and high-power conversion efficiencies of ∼9% in solar cells, resulting in photon energy loss as small as ∼0.5 eV, which is much smaller than that of typical polymer systems (0.7-1.0 eV). This is ascribed to the high external quantum efficiency for the systems with a very small energy offset for charge separation. These unconventional features of the present polymer system will inspire the field of polymer-based solar cells towards further improvement of power conversion efficiencies with both high short-circuit current density and open-circuit voltage. PMID:26626042

  4. A Very Small and Super Strong Zebra Pattern Burst at the Beginning of a Solar Flare

    NASA Astrophysics Data System (ADS)

    Tan, Baolin; Tan, Chengming; Zhang, Yin; Huang, Jing; Mészárosová, Hana; Karlický, Marian; Yan, Yihua

    2014-08-01

    Microwave emission with spectral zebra pattern structures (ZPs) is frequently observed in solar flares and the Crab pulsar. The previous observations show that ZP is a structure only overlapped on the underlying broadband continuum with slight increments and decrements. This work reports an unusually strong ZP burst occurring at the beginning of a solar flare observed simultaneously by two radio telescopes located in China and the Czech Republic and by the EUV telescope on board NASA's satellite Solar Dynamics Observatory on 2013 April 11. It is a very short and super strong explosion whose intensity exceeds several times that of the underlying flaring broadband continuum emission, lasting for just 18 s. EUV images show that the flare starts from several small flare bursting points (FBPs). There is a sudden EUV flash with extra enhancement in one of these FBPs during the ZP burst. Analysis indicates that the ZP burst accompanying an EUV flash is an unusual explosion revealing a strong coherent process with rapid particle acceleration, violent energy release, and fast plasma heating simultaneously in a small region with a short duration just at the beginning of the flare.

  5. A very small and super strong zebra pattern burst at the beginning of a solar flare

    SciTech Connect

    Tan, Baolin; Tan, Chengming; Zhang, Yin; Huang, Jing; Yan, Yihua; Mészárosová, Hana; Karlický, Marian

    2014-08-01

    Microwave emission with spectral zebra pattern structures (ZPs) is frequently observed in solar flares and the Crab pulsar. The previous observations show that ZP is a structure only overlapped on the underlying broadband continuum with slight increments and decrements. This work reports an unusually strong ZP burst occurring at the beginning of a solar flare observed simultaneously by two radio telescopes located in China and the Czech Republic and by the EUV telescope on board NASA's satellite Solar Dynamics Observatory on 2013 April 11. It is a very short and super strong explosion whose intensity exceeds several times that of the underlying flaring broadband continuum emission, lasting for just 18 s. EUV images show that the flare starts from several small flare bursting points (FBPs). There is a sudden EUV flash with extra enhancement in one of these FBPs during the ZP burst. Analysis indicates that the ZP burst accompanying an EUV flash is an unusual explosion revealing a strong coherent process with rapid particle acceleration, violent energy release, and fast plasma heating simultaneously in a small region with a short duration just at the beginning of the flare.

  6. Extrapolation of space weathering processes to other small solar system bodies

    NASA Technical Reports Server (NTRS)

    Gaffey, M. J.

    1993-01-01

    A diverse range of processes were invoked as the dominant factor or as important contributory factors in the modification of the optical surface and regolith of the moon. These include impact vitrification by large and small projectiles, solar wind implantation and the reduction of oxidized iron during energetic events, sputtering and crystal lattice damage by energetic cosmic rays, shock metamorphism of minerals, mixing of diverse lithologies by impacts, and contamination by external materials. These processes are also potentially important on the rocky surfaces of other small solar system bodies. For icy bodies, several additional processes are also possible, including formation of complex organic compounds from methane and ammonia-bearing ices by ultraviolet irradiation and the condensation of vapor species to form frost layers in the polar or cooler regions of objects at appropriate heliocentric distances. The lunar case, even when completely understood, will not extend in a simple linear fashion to other small rocky objects, nor will the optical surfaces of those objects all be affected to the same degree by each process. The major factors that will control the relative efficacy of a possible mechanism include the efficiency of ejecta retention and the degree to which the regolith materials experience multiple events (primarily a function of body size, escape velocity, and impactor velocities); the mean duration of typical regolith particle exposure at the optical surface and within reach of the micrometeorite, cosmic ray, solar wind, or UV fluxes (a function of the rate and scale of regolith mixing, production, and removal processes); the incident flux of solar (low energy) cosmic rays, solar wind, or UV radiation (inverse square of heliocentric distance) or of galactic (high energy) cosmic rays (slowly increasing flux with heliocentric distance); and the compositional and mineralogical nature of the surface being affected. In general, those processes that

  7. Self-assembled ultra small ZnO nanocrystals for dye-sensitized solar cell application

    SciTech Connect

    Patra, Astam K.; Dutta, Arghya; Bhaumik, Asim

    2014-07-01

    We demonstrate a facile chemical approach to produce self-assembled ultra-small mesoporous zinc oxide nanocrystals using sodium salicylate (SS) as a template under hydrothermal conditions. These ZnO nanomaterials have been successfully fabricated as a photoanode for the dye-sensitized solar cell (DSSC) in the presence of N719 dye and iodine–triiodide electrolyte. The structural features, crystallinity, purity, mesophase and morphology of the nanostructure ZnO are investigated by several characterization tools. N{sub 2} sorption analysis revealed high surface areas (203 m{sup 2} g{sup −1}) and narrow pore size distributions (5.1–5.4 nm) for different samples. The mesoporous structure and strong photoluminescence facilitates the high dye loading at the mesoscopic void spaces and light harvesting in DSSC. By utilizing this ultra-small ZnO photoelectrode with film thickness of about 7 μm in the DSSC with an open-circuit voltage (V{sub OC}) of 0.74 V, short-circuit current density (J{sub SC}) of 3.83 mA cm{sup −2} and an overall power conversion efficiency of 1.12% has been achieved. - Graphical abstract: Ultra-small ZnO nanocrystals have been synthesized with sodium salicylate as a template and using it as a photoanode in a dye-sensitized solar cell 1.12% power conversion efficiency has been observed. - Highlights: • Synthesis of self-assembled ultra-small mesoporous ZnO nanocrystals by using sodium salicylate as a template. • Mesoporous ZnO materials have high BET surface areas and void space. • ZnO nanoparticles serve as a photoanode for the dye-sensitized solar cell (DSSC). • Using ZnO nanocrystals as photoelectrode power conversion efficiency of 1.12% has been achieved.

  8. Performance Enhancement of Small Molecular Solar Cells by Bilayer Cathode Buffer.

    PubMed

    Sun, Qinjun; Zhao, Huanbin; Zhou, Miao; Gao, Liyan; Hao, Yuying

    2016-04-01

    An effective composite bilayer cathode buffer structure is proposed for use in small molecular solar cells. CsF was doped in Alq3 to form the first cathode buffer, leading to small serial resistances. BCP was used as the second cathode buffer to block the holes to the electrode. The optimized bilayer cathode buffer significantly increased the short circuit and fill factor of devices. By integrating this bilayer cathode buffer, the CuPc/C60 small molecular heterojunction cell exhibited a power conversion efficiency of up to 0.8%, which was an improvement of 56% compared to a device with only the Alq3 cathode buffer. Meanwhile, the bilayer cathode buffer still has a good protective effect on the performance of the device. PMID:27451719

  9. Advancements of the Lightweight Integrated Solar Array and Transceiver (LISA-T) Small Spacecraft System

    NASA Technical Reports Server (NTRS)

    Lockett, Tiffany Russell; Martinez, Armando; Boyd, Darren; SanSouice, Michael; Farmer, Brandon; Schneider, Todd; Laue, Greg; Fabisinski, Leo; Johnson, Les; Carr, John A.

    2015-01-01

    This paper describes recent advancements of the Lightweight Integrated Solar Array and Transceiver (LISA-T) currently being developed at NASA's Marshall Space Flight Center. The LISA-T array comprises a launch stowed, orbit deployed structure on which thin-film photovoltaic (PV) and antenna devices are embedded. The system provides significant electrical power generation at low weights, high stowage efficiency, and without the need for solar tracking. Leveraging high-volume terrestrial-market PVs also gives the potential for lower array costs. LISA-T is addressing the power starvation epidemic currently seen by many small-scale satellites while also enabling the application of deployable antenna arrays. Herein, an overview of the system and its applications are presented alongside sub-system development progress and environmental testing plans.

  10. Advancements of the Lightweight Integrated Solar Array and Transceiver (LISA-T) Small Spacecraft System

    NASA Technical Reports Server (NTRS)

    Russell, Tiffany; Martinez, Armando; Boyd, Darren; SanSoucie, Michael; Farmer, Brandon; Schneider, Todd; Fabisinski, Leo; Johnson, Les; Carr, John A.

    2015-01-01

    This paper describes recent advancements of the Lightweight Integrated Solar Array and Transceiver (LISA-T) currently being developed at NASA's Marshall Space Flight Center. The LISA-T array comprises a launch stowed, orbit deployed structure on which thin-film photovoltaic (PV) and antenna devices are embedded. The system provides significant electrical power generation at low weights, high stowage efficiency, and without the need for solar tracking. Leveraging high-volume terrestrial-market PVs also gives the potential for lower array costs. LISA-T is addressing the power starvation epidemic currently seen by many small-scale satellites while also enabling the application of deployable antenna arrays. Herein, an overview of the system and its applications are presented alongside sub-system development progress and environmental testing plans/initial results.

  11. Hybrid solar cells with ZnO-nanorods and dry processed small molecule absorber

    NASA Astrophysics Data System (ADS)

    Riedel, W.; Wiesner, S.; Greiner, D.; Hinrichs, V.; Rusu, M.; Lux-Steiner, M. Ch.

    2014-04-01

    We demonstrate hybrid solar cells with ZnO-nanorods (ZnO-NRs) prepared by a low temperature electrochemical method and small molecule organic absorber processed by dry organic vapor phase deposition. A homogeneous coverage of ZnO-NRs by the blend absorber consisting of zinc phthalocyanine (ZnPc) as donor and of fullerene C60 as acceptor is best realized when a thin C60 layer is first inserted at the ZnO-NR/ZnPc:C60 interface. ZnO-NR/C60/ZnPc:C60/MoO3/Ag solar cell devices with efficiencies of 2.8% under an illumination of 100 mW/cm2 at 25 °C are demonstrated.

  12. Detection of small-scale structures in the dissipation regime of solar-wind turbulence.

    PubMed

    Perri, S; Goldstein, M L; Dorelli, J C; Sahraoui, F

    2012-11-01

    Recent observations of the solar wind have pointed out the existence of a cascade of magnetic energy from the scale of the proton Larmor radius ρ(p) down to the electron Larmor radius ρ(e) scale. In this Letter we study the spatial properties of magnetic field fluctuations in the solar wind and find that at small scales the magnetic field does not resemble a sea of homogeneous fluctuations, but rather a two-dimensional plane containing thin current sheets and discontinuities with spatial sizes ranging from l >/~ ρ(p) down to ρ(e) and below. These isolated structures may be manifestations of intermittency that localize sites of turbulent dissipation. Studying the relationship between turbulent dissipation, reconnection, and intermittency is crucial for understanding the dynamics of laboratory and astrophysical plasmas. PMID:23215371

  13. Japanese Exploration to Solar System Small Bodies: Rewriting a Planetary Formation Theory with Astromaterial Connection (Invited)

    NASA Astrophysics Data System (ADS)

    Yano, H.

    2013-12-01

    Three decades ago, Japan's deep space exploration started with Sakigake and Suisei, twin flyby probes to P/Halley. Since then, the Solar System small bodies have been one of focused destinations to the Japanese solar system studies even today. Only one year after the Halley armada launch, the very first meeting was held for an asteroid sample return mission at ISAS, which after 25 years, materialized as the successful Earth return of Hayabusa , an engineering verification mission for sample return from surfaces of an NEO for the first time in the history. Launched in 2003 and returned in 2010, Hayabusa became the first to visit a sub-km, rubble-pile potentially hazardous asteroid in near Earth space. Its returned samples solved S-type asteroid - ordinary chondrite paradox by proving space weathering evidences in sub-micron scale. Between the Halley missions and Hayabusa, SOCCER concept by M-V rocket was jointly studied between ISAS and NASA; yet it was not realized due to insufficient delta-V for intact capture by decelerating flyby/encounter velocity to a cometary coma. The SOCCER later became reality as Stardust, NASA Discovery mission for cometary coma dust sample return in1999-2006. Japan has collected the second largest collection of the Antarctic meteorites and micrometeorites of the world and asteromaterial scientists are eager to collaborate with space missions. Also Japan enjoyed a long history of collaborations between professional astronomers and high-end amateur observers in the area of observational studies of asteroids, comets and meteors. Having these academic foundations, Japan has an emphasis on programmatic approach to sample returns of Solar System small bodies in future prospects. The immediate follow-on to Hayabusa is Hayabusa-2 mission to sample return with an artificial impactor from 1999 JU3, a C-type NEO in 2014-2020. Following successful demonstration of deep space solar sail technique by IKAROS in 2010-2013, the solar power sail is a deep

  14. Modeling the small-scale dish-mounted solar thermal Brayton cycle

    NASA Astrophysics Data System (ADS)

    Le Roux, Willem G.; Meyer, Josua P.

    2016-05-01

    The small-scale dish-mounted solar thermal Brayton cycle (STBC) makes use of a sun-tracking dish reflector, solar receiver, recuperator and micro-turbine to generate power in the range of 1-20 kW. The modeling of such a system, using a turbocharger as micro-turbine, is required so that optimisation and further development of an experimental setup can be done. As a validation, an analytical model of the small-scale STBC in Matlab, where the net power output is determined from an exergy analysis, is compared with Flownex, an integrated systems CFD code. A 4.8 m diameter parabolic dish with open-cavity tubular receiver and plate-type counterflow recuperator is considered, based on previous work. A dish optical error of 10 mrad, a tracking error of 1° and a receiver aperture area of 0.25 m × 0.25 m are considered. Since the recuperator operates at a very high average temperature, the recuperator is modeled using an updated ɛ-NTU method which takes heat loss to the environment into consideration. Compressor and turbine maps from standard off-the-shelf Garrett turbochargers are used. The results show that for the calculation of the steady-state temperatures and pressures, there is good comparison between the Matlab and Flownex results (within 8%) except for the recuperator outlet temperature, which is due to the use of different ɛ-NTU methods. With the use of Matlab and Flownex, it is shown that the small-scale open STBC with an existing off-the-shelf turbocharger could generate a positive net power output with solar-to-mechanical efficiency of up to 12%, with much room for improvement.

  15. Enhanced performances in inverted small molecule solar cells by Ag nanoparticles.

    PubMed

    Jin, Fangming; Chu, Bei; Li, Wenlian; Su, Zisheng; Zhao, Haifeng; Lee, C S

    2014-12-15

    We demonstrate a highly efficient inverted small molecular solar cell with integration of Ag nanoparticles (NPs) into the devices. The optimized device based on thermal evaporated Ag NPs provides a power conversion efficiency (PCE) of 4.87%, which offers 33% improvement than that of the reference device without Ag NPs. Such a high efficiency is mainly attributed to the improved electrical properties by virtue of the modification of the surface of ITO with Ag NPs and the enhanced light harvesting due to localized surface plasmon resonance (LSPR). The more detail enhanced mechanism of the PCE by introduction of Ag NPs is also discussed. PMID:25607480

  16. Convergence at the surface; divergence beneath: cross-agency working within a small-scale, schools-based project.

    PubMed

    O'Brien, Mark

    2011-12-01

    In the UK school system social remits - requiring schools to work towards improved social as well as educational outcomes for children - have become significant over the last decade. This study focuses upon the inter-professional issues in the running of one small-scale intervention involving parents and their babies based in schools in an urban setting in the UK. The programme, run over the school year 2007/08, provided a professional framework in which parents from the local community surrounding a school brought their babies into classroom settings to talk about aspects of baby care and development. This professional framework included classroom teachers, one senior cross-school education manager, family health visitors and one senior children's health nurse. Despite agreement about the benefits of the programme there were also clear differences of priority. This paper describes the different perceptions that each of these two sets of professionals - from health and from education - had of the programme, and highlights some critical perspectives that tended to come more from health professionals. It also maps out potential solutions which draw upon recent literature that is similarly focused upon inter-professional and inter-agency service delivery. In so doing it offers valuable insights to professionals working in inter-agency collaborations in schools. PMID:21828171

  17. Structure-property relationships of small bandgap conjugated polymers for solar cells.

    PubMed

    Hellström, Stefan; Zhang, Fengling; Inganäs, Olle; Andersson, Mats R

    2009-12-01

    Conjugated polymers as electron donors in solar cells based on donor/acceptor combinations are of great interest, partly due to the possibility of converting solar light with a low materials budget. Six small bandgap polymers with optical bandgap ranging from 1.0-1.9 eV are presented in this paper. All polymers utilize an electron donor-acceptor-donor (DAD) segment in the polymer backbone, creating a partial charge-transfer, to decrease the bandgap. The design, synthesis and the optical characteristics as well as the solar cell characteristics of the polymers are discussed. The positions of the energy levels of the conjugated polymer relative to the electron acceptor are of significant importance and determine not only the driving force for exciton dissociation but also the maximum open-circuit voltage. This work also focuses on investigating the redox behavior of the described conjugated polymers and electron acceptors using square wave voltammetry. Comparing the electrochemical data gives important information of the structure-property relationships of the polymers. PMID:19904430

  18. Power Spectra, Power Law Exponents, and Anisotropy of Solar Wind Turbulence at Small Scales

    NASA Technical Reports Server (NTRS)

    Podesta, J. J.; Roberts, D. A.; Goldstein, M. L.

    2006-01-01

    The Wind spacecraft provides simultaneous solar wind velocity and magnetic field measurements with 3- second time resolution, roughly an order of magnitude faster than previous measurements, enabling the small scale features of solar wind turbulence to be studied in unprecedented detail. Almost the entire inertial range can now be explored (the inertial range extends from approximately 1 to 10(exp 3) seconds in the spacecraft frame) although the dissipation range of the velocity fluctuations is still out of reach. Improved measurements of solar wind turbulence spectra at 1 AU in the ecliptic plane are presented including spectra of the energy and cross-helicity, the magnetic and kinetic energies, the Alfven ratio, the normalized cross-helicity, and the Elsasser ratio. Some recent observations and theoretical challenges are discussed including the observation that the velocity and magnetic field spectra often show different power law exponents with values close to 3/2 and 5/3, respectively; the energy (kinetic plus magnetic) and cross-helicity often have approximately equal power law exponents with values intermediate between 3/2 and 5/3; and the Alfven ratio, the ratio of the kinetic to magnetic energy spectra, is often a slowly increasing function of frequency increasing from around 0.4 to 1 for frequencies in the inertial range. Differences between high- and low-speed wind are also discussed. Comparisons with phenomenological turbulence theories show that important aspects of the physics are yet unexplained.

  19. Long-Term Dynamics of Small Bodies in the Solar System

    NASA Technical Reports Server (NTRS)

    Saunders, Steve (Technical Monitor); Holman, Matthew J.

    2005-01-01

    As part of the NASA Planetary Geology and Geophysics program Prof. Norm Murray (CITA) and I have been conducting investigations of the long-term dynamics of small bodies in the outer solar system. This grant, and its predecessor NAG5-7761, supported travel for collaboration by the Investigators and also supports Murray during an annual one month visit to the CfA for further collaboration. In the course of this grant we made a number of advances in solar system dynamics. For example, we developed an analytic model for the origin and consequence of chaos associated with three-body resonances in the asteroid belt. This has been shown to be important for the delivery of near Earth objects. We later extended this model to three-body resonances among planets. We were able to show that the numerically identified chaos among the outer planets results from a three-body resonance involving Jupiter, Saturn, and Uranus. The resulting paper was awarded the 1999 Newcomb Cleveland award from the AAAS. This award singles out one paper published in Science each year for distinction. This grant has also supported, in part, my participate in other solar system dynamics projects. The results from those collaborations are also listed.

  20. The performance of solar thermal electric power systems employing small heat engines

    NASA Technical Reports Server (NTRS)

    Pons, R. L.

    1980-01-01

    The paper presents a comparative analysis of small (10 to 100 KWe) heat engines for use with a solar thermal electric system employing the point-focusing, distributed receiver (PF-DR) concept. Stirling, Brayton, and Rankine cycle engines are evaluated for a nominal overall system power level of 1 MWe, although the concept is applicable to power levels up to at least 10 MWe. Multiple concentrators are electrically connected to achieve the desired plant output. Best performance is achieved with the Stirling engine, resulting in a system Levelized Busbar Energy Cost of just under 50 mills/kWH and a Capital Cost of $900/kW, based on the use of mass-produced components. Brayton and Rankine engines show somewhat less performance but are viable alternatives with particular benefits for special applications. All three engines show excellent performance for the small community application.

  1. The performance of solar thermal electric power systems employing small heat engines

    NASA Astrophysics Data System (ADS)

    Pons, R. L.

    1980-02-01

    The paper presents a comparative analysis of small (10 to 100 KWe) heat engines for use with a solar thermal electric system employing the point-focusing, distributed receiver (PF-DR) concept. Stirling, Brayton, and Rankine cycle engines are evaluated for a nominal overall system power level of 1 MWe, although the concept is applicable to power levels up to at least 10 MWe. Multiple concentrators are electrically connected to achieve the desired plant output. Best performance is achieved with the Stirling engine, resulting in a system Levelized Busbar Energy Cost of just under 50 mills/kWH and a Capital Cost of $900/kW, based on the use of mass-produced components. Brayton and Rankine engines show somewhat less performance but are viable alternatives with particular benefits for special applications. All three engines show excellent performance for the small community application.

  2. Complex Organic Materials on Planetary Satellites and Other Small Bodies of the Solar System

    NASA Technical Reports Server (NTRS)

    Cruikshank, Dale P.

    2006-01-01

    The search for organic materials on small bodies of the Solar System is conducted spectroscopically from Earth-based telescopes and from spacecraft. Although the carbonaceous meteorites carry a significant inventory of complex organic solids, the sources of these meteorites have not been identified. Infrared spectra of a sample of the suspected sources, the C- and D-class asteroids, including new data from the Spitzer Space Telescope, show signatures of silicates, but none diagnostic of organic compounds. In the absence of discrete spectral features, the low albedos and colors in the visible and near-IR spectral regions are the principal links between the organic-bearing meteorites and the asteroids. While Pluto and a few trans-neptunian objects show spectral signatures of frozen CH4. Solid CH3OH has been identified on two Centaur objects in the outer Solar System. In some cases the red colors of those objects suggest the presence of tholins. The VIMS instrument aboard the Cassini spacecraft in orbit around Saturn has detected near-IR spectral features on at least three of Saturn's satellites that are indicative or suggestive of organic molecules. One entire hemisphere of the satellite Iapetus is covered with low-albedo material that shows a spectral signature of aromatic hydrocarbons (3.3 microns) and the -CH2 stretching mode bands of an aliphatic component. Organics absorbing at 3.44 microns are suspected in the region of the south pole of Enceladus, and also on the surface of Phoebe. Organic material may originate on icy bodies in the current epoch by various processes of energy deposition into native material, or they may fall to the surface from an external (probably cometary) source. Some organic material may be pre-solar, having originated in the interstellar medium before the formation of the Solar System. Using the techniques of remote sensing, its detection and analysis are slow and difficult.

  3. THE LATITUDE DISTRIBUTION OF SMALL-SCALE MAGNETIC ELEMENTS IN SOLAR CYCLE 23

    SciTech Connect

    Jin, C. L.; Wang, J. X. E-mail: wangjx@nao.cas.cn

    2012-01-20

    With the unique data set from full-disk observations provided by Michelson Doppler Imager on board the Solar and Heliospheric Observatory in the interval embodying solar cycle 23, we have found that the cyclic variations of numbers and total flux of these small-scale magnetic elements covering fluxes of (2.9-32.0) Multiplication-Sign 10{sup 18} Mx and (4.27-38.01) Multiplication-Sign 10{sup 19} Mx show anticorrelation and correlation with sunspots, respectively. In this study, the time-latitude distributions of these anticorrelated and correlated elements are analyzed. The following results are disclosed: (1) for the correlated elements, the cyclic variations of the total flux in low-latitude and middle-latitude regions show a longer duration of cyclic maximum phase than that of an active region (AR) in the corresponding latitude region; the total flux of these elements shows the accordant south-north asymmetry with that of AR; the time-latitude distribution of their number displays a similar butterfly diagram but with a latitude distribution that is twice as wide as that of sunspots. (2) For the anticorrelated elements, the time-latitude distribution of number shows a solar cycle variation different from the sunspot butterfly diagram; in each latitude, the distribution of anticorrelated elements always shows the anticorrelated variation with that of sunspots; during solar cycle 23, the average speed of the peak latitudinal migration for anticorrelated elements reaches 7.5 deg year{sup -1}, almost three times that for sunspots. These results seem to imply that the correlated elements are the debris of decayed sunspots, and the anticorrelated elements have a different source but are affected or modulated by sunspot magnetic field.

  4. The Latitude Distribution of Small-scale Magnetic Elements in Solar Cycle 23

    NASA Astrophysics Data System (ADS)

    Jin, C. L.; Wang, J. X.

    2012-01-01

    With the unique data set from full-disk observations provided by Michelson Doppler Imager on board the Solar and Heliospheric Observatory in the interval embodying solar cycle 23, we have found that the cyclic variations of numbers and total flux of these small-scale magnetic elements covering fluxes of (2.9-32.0) × 1018 Mx and (4.27-38.01) × 1019 Mx show anticorrelation and correlation with sunspots, respectively. In this study, the time-latitude distributions of these anticorrelated and correlated elements are analyzed. The following results are disclosed: (1) for the correlated elements, the cyclic variations of the total flux in low-latitude and middle-latitude regions show a longer duration of cyclic maximum phase than that of an active region (AR) in the corresponding latitude region; the total flux of these elements shows the accordant south-north asymmetry with that of AR; the time-latitude distribution of their number displays a similar butterfly diagram but with a latitude distribution that is twice as wide as that of sunspots. (2) For the anticorrelated elements, the time-latitude distribution of number shows a solar cycle variation different from the sunspot butterfly diagram; in each latitude, the distribution of anticorrelated elements always shows the anticorrelated variation with that of sunspots; during solar cycle 23, the average speed of the peak latitudinal migration for anticorrelated elements reaches 7.5 deg year-1, almost three times that for sunspots. These results seem to imply that the correlated elements are the debris of decayed sunspots, and the anticorrelated elements have a different source but are affected or modulated by sunspot magnetic field.

  5. Optimization Study of Small-Scale Solar Membrane Distillation Desalination Systems (s-SMDDS)

    PubMed Central

    Chang, Hsuan; Chang, Cheng-Liang; Hung, Chen-Yu; Cheng, Tung-Wen; Ho, Chii-Dong

    2014-01-01

    Membrane distillation (MD), which can utilize low-grade thermal energy, has been extensively studied for desalination. By incorporating solar thermal energy, the solar membrane distillation desalination system (SMDDS) is a potential technology for resolving energy and water resource problems. Small-scale SMDDS (s-SMDDS) is an attractive and viable option for the production of fresh water for small communities in remote arid areas. The minimum cost design and operation of s-SMDDS are determined by a systematic method, which involves a pseudo-steady-state approach for equipment sizing and dynamic optimization using overall system mathematical models. Two s-SMDDS employing an air gap membrane distillation module with membrane areas of 11.5 m2 and 23 m2 are analyzed. The lowest water production costs are $5.92/m3 and $5.16/m3 for water production rates of 500 kg/day and 1000 kg/day, respectively. For these two optimal cases, the performance ratios are 0.85 and 0.91; the recovery ratios are 4.07% and 4.57%. The effect of membrane characteristics on the production cost is investigated. For the commercial membrane employed in this study, the increase of the membrane mass transfer coefficient up to two times is beneficial for cost reduction. PMID:25421065

  6. Optimization study of small-scale solar membrane distillation desalination systems (s-SMDDS).

    PubMed

    Chang, Hsuan; Chang, Cheng-Liang; Hung, Chen-Yu; Cheng, Tung-Wen; Ho, Chii-Dong

    2014-11-01

    Membrane distillation (MD), which can utilize low-grade thermal energy, has been extensively studied for desalination. By incorporating solar thermal energy, the solar membrane distillation desalination system (SMDDS) is a potential technology for resolving energy and water resource problems. Small-scale SMDDS (s-SMDDS) is an attractive and viable option for the production of fresh water for small communities in remote arid areas. The minimum cost design and operation of s-SMDDS are determined by a systematic method, which involves a pseudo-steady-state approach for equipment sizing and dynamic optimization using overall system mathematical models. Two s-SMDDS employing an air gap membrane distillation module with membrane areas of 11.5 m(2) and 23 m(2) are analyzed. The lowest water production costs are $5.92/m(3) and $5.16/m(3) for water production rates of 500 kg/day and 1000 kg/day, respectively. For these two optimal cases, the performance ratios are 0.85 and 0.91; the recovery ratios are 4.07% and 4.57%. The effect of membrane characteristics on the production cost is investigated. For the commercial membrane employed in this study, the increase of the membrane mass transfer coefficient up to two times is beneficial for cost reduction. PMID:25421065

  7. Small- Geo Solar Array: New Generation Of Solar Arrays For Commercial Telecom Satellites For Power Ranges Between 2,5 KW And 7,5 KW

    NASA Astrophysics Data System (ADS)

    Paarmann, Carola; Muller, Jens; Mende, Thomas; Borner, Carsten; Mascher, Rolf

    2011-10-01

    In the frame of the ESA supported Artes 11 program a new generation of GEO telecommunication satellites is under development. This platform will cover the power range from 2 to 5 kW. ASTRIUM GmbH is contracted to develop and design the Solar Array for this platform. Furthermore the manufacturing and the qualification of a PFM wing for the first flight model is foreseen. The satellite platform, called Small-GEO, is developed under the responsibility of OHB System. This first Small-GEO satellite is designated to be delivered to HISPASAT for operation. The concept of ASTRIUM GmbH is to use all the experiences from the very successful EUROSTAR 2000+, EUROSTAR-3000 and the ALPHABUS platform and to adapt the technologies to the Small- GEO Solar Array. With the benefit of the huge in-orbit heritage of these programs, the remaining risks for the Small-GEO Solar Array can be minimized. The development of the Small-GEO Solar Array extends the ASTRIUM GmbH product portfolio by covering now the complete power range between 2 kW and 31 kW. This paper provides an overview of the different configurations, their main design features and parameters.

  8. SMALL-SCALE MICROWAVE BURSTS IN LONG-DURATION SOLAR FLARES

    SciTech Connect

    Tan Baolin

    2013-08-20

    Solar small-scale microwave bursts (SMBs), including microwave dot, spike, and narrow-band type III bursts, are characterized by very short timescales, narrow frequency bandwidth, and very high brightness temperatures. Based on observations of the Chinese Solar Broadband Radio Spectrometer at Huairou with superhigh cadence and frequency resolution, this work presents an intensive investigation of SMBs in several flares that occurred in active region NOAA 10720 during 2005 January 14-21. Especially for long-duration flares, the SMBs occurred not only in the early rising and impulsive phase, but also in the flare decay phase and even after the end of the flare. These SMBs are strong bursts with inferred brightness temperatures of at least 8.18 Multiplication-Sign 10{sup 11}-1.92 Multiplication-Sign 10{sup 13} K, very short lifetimes of 5-18 ms, relative frequency bandwidths of 0.7%-3.5%, and superhigh frequency drifting rates. Together with their obviously different polarizations from background emission (the quiet Sun, and the underlying flaring broadband continuum), such SMBs should be individual, independent strong coherent bursts related to some non-thermal energy release and the production of energetic particles in a small-scale source region. These facts show the existence of small-scale strong non-thermal energy releasing activities after the flare maxima, which is meaningful for predicting space weather. Physical analysis indicates that a plasma mechanism may be the most favorable candidate for the formation of SMBs. From the plasma mechanism, the velocities and kinetic energy of fast electrons can be deduced and the region of electron acceleration can also be tracked.

  9. A Compact Solar Spectral Irradiance Monitor for Future Small Satellite and CubeSat Science Opportunities

    NASA Astrophysics Data System (ADS)

    Richard, E. C.; Harber, D.; Snow, M. A.; Harder, J. W.

    2013-12-01

    Accurate and continuous measurements of solar spectral irradiance (SSI) is recognized as being increasingly important to advancing our understanding of the solar influence on Earth's climate. For example, the magnitude of SSI UV variability has significant implications, both directly and indirectly, for the response of the stratosphere and mesosphere, whereas the visible and near infrared SSI variability influences the radiative balance, thermal structure, and dynamics of the lower atmosphere and ocean layers. Recent SSI measurements are providing critical inputs in evaluating and improving present climate models, however they are not yet of sufficient accuracy to stand alone without overlapping records - gaps in the observational record, caused by future mission delays or early failures of existing missions, effectively destroy our ability to link records from different instruments into a continuous, long-term climate quality record. Recent advancements in calibration facilities and techniques make it now possible to improve significantly the accuracy and traceability of future SSI observations and assure quantification of uncertainty as input to increasingly more sophisticated climate models. The goal of the proposed compact SSI monitor is to cover 200-2400 nm with the required SI-traceable accuracy and on-orbit stability to meet the solar input measurement requirements defined in the Earth Science Decadal Survey for establishing benchmark climate records. Building upon our experiences and resources from the Total and Spectral Solar Irradiance Sensor (TSIS) program, the instrument will reduce the cost, size, and characterization and calibration schedule of a solar spectral irradiance monitor with SI-traceable absolute calibration at the 0.2% uncertainty level (k=1) while maintaining 100 ppm relative stability. System level performance characterizations and final end-to-end absolute irradiance calibration will be accomplished with the LASP Spectral Radiometer

  10. Catastrophic disruption in the solar system - Asteroid collisional history, origin of Hirayama families and disruption of small satellites

    NASA Technical Reports Server (NTRS)

    Davis, D. R.

    1986-01-01

    The process of collisional catastrophic disruption has played a significantly role in structuring the solar system. Diverse populations of bodies such as the asteroid belt, small satellites of Jupiter and Saturn and perhaps even the rings of Saturn have been created or substantially changed by catastrophic distruption. Understanding the outcome of large scale impacts is essential to learning about the early history of the solar system in the asteroid zone and the reason why a planet failed to form there.

  11. Estimations on the Interior of Small Icy Bodies in the Solar System

    NASA Astrophysics Data System (ADS)

    Taubner, Ruth-Sophie; Leitner, Johannes J.; Firneis, Maria G.; Hitzenberger, Regina

    2014-05-01

    During the last decade small icy bodies have become more and more important for the search for potential habitats in the Solar System. This development was primarily attributable to the indications for Europa's subsurface ocean (e.g., Carr et al., 1998) and the detection of Enceladus' plume (Porco et al., 2006). These observations showed that liquid water can exist under certain circumstances even far beyond the classical habitable zone (Kasting et al., 1993). Additionally, the subsurface water reservoirs may contain a significant amount of ammonia which causes the fluid to stay liquid even below 0°C. If liquid water is in contact with the rocky layer, erosion or similar interaction processes will take place and enrich the water with possible nutrients for potential life forms in this habitat. Therefore, especially the water/rock boundary zone seems highly interesting for astrobiological studies. We developed a three and four layer model for the interior of small icy bodies, i.e. icy moons, TNOs, and asteroids as small as 200 km in radius. The simulations are based on three different scenarios which consider the diverse interior structures of three selected prototype satellites (Io, Europa, and Titan). On average, the water layer represents approximately 20 % of the bodies' radii for the Europa- and Titan-like model. In contrast, for the Io-like scenario, in which we do not include a global subsurface ocean, just Io, the Moon, Vesta, and Hygiea fit into the model. This may indicate that water/ice-regions or even liquid water shells are far more common in the Solar System than previously assumed. Furthermore, we estimate the bodies' dimensionless moment of inertia and compare our results to observed values as far as they are available. Moreover, the physical conditions at the bottom of the bodies' potential subsurface ocean and the thickness of each layer will be estimated. This study will give us a good overview about the distribution of potential liquid water

  12. Signatures of Small-Scale Magnetic Field Emergence as Seen from the New Solar Telescope in Big Bear

    NASA Astrophysics Data System (ADS)

    Yurchyshyn, V.

    2011-12-01

    Increased resolution of solar telescopes allow us to study emerging small-scale magnetic fields in unprecedented detail. First light Hinode magnetograms showed evidence of both horizontal and line-of-sight field being constantly brought to the solar surface by solar convection motion. What are the signatures of these fields in the photosphere, if any? The largest aperture ground-based solar telescope, the New Solar Telescope (NST) of Big Bear Solar Observatory now allows us to address many important issues of coupling between the photosphere and chromosphere by means of simultaneous observations of photospheric granulation with well-resolved bright points (BPs) and associated dynamics in the low chromosphere, as seen in the H-alpha spectral line. Excellent seeing conditions, augmented with an adaptive optics system and speckle-reconstruction applications produce diffraction limited images. We examine NST granulation and Halpha images co-temporal with SDO, Hinode and BBSO/IRIM vector magnetograms. Our main finding is that emerging magnetic flux leaves clear footprint in solar granulation. Moreover, the granulation responds to the emerging flux much earlier that it appears in magnetograms. NST granulation images also reveal that various bright points as well as bright granular lanes may form and evolve within a granule. These newly detected features are believed to be associated with small-scale magnetic fields.

  13. Passive-solar-cooling system concepts for small office buildings. Final report

    SciTech Connect

    Whiddon, W.I.; Hart, G.K.

    1983-02-01

    This report summarizes the efforts of a small group of building design professionals and energy analysis experts to develop passive solar cooling concepts including first cost estimates for small office buildings. Two design teams were brought together at each of two workshops held in the fall of 1982. Each team included an architect, mechanical engineer, structural engineer, and energy analysis expert. This report presents the passive cooling system concepts resulting from the workshops. It summarizes the design problems, solutions and first-cost estimates relating to each technology considered, and documents the research needs identified by the participants in attempting to implement the various technologies in an actual building design. Each design problem presented at the workshops was based on the reference (base case) small office building analyzed as part of LBL's Cooling Assessment. Chapter II summarizes the thermal performance, physical specifications and estimated first-costs of the base case design developed for this work. Chapters III - VI describe the passive cooling system concepts developed for each technology: beam daylighting; mass with night ventilation; evaporative cooling; and integrated passive cooling systems. The final Chapters, VII and VIII present the preliminary implications for economics of passive cooling technologies (based on review of the design concepts) and recommendations of workshop participants for future research in passive cooling for commercial buildings. Appendices provide backup information on each chapter as indicated.

  14. Solar wind sputtering of small bodies: Exospheres of Phobos and Deimos

    NASA Astrophysics Data System (ADS)

    Schaible, M. J.; Johnson, R. E.; Lee, P.; Benna, M.; Elphic, R. C.

    2014-12-01

    Solar wind, magnetospheric ions and micrometeorites impact the surface of airless bodies in the solar system and deposit energy in the surface material. Excitation and momentum transfer processes lead to sputtering or desorption of molecules and atoms, thereby creating a dynamic exosphere about an otherwise airless body. Ion mass spectrometry of ejected materials provides a highly sensitive method for detecting sputter products and determining the surface composition [Johnson and Baragiola, 1991; Elphic et al., 1991]. Though most of the material is sputtered as neutral gas, UV photons can ionize ejected neutrals and a small fraction of the ejecta leaves the surface in an ionized state. However, ions are deflected by the variably-oriented solar wind magnetic field and thus relating their detection to a surface location can be problematic. Here we estimate the average ion density close to the surface of Phobos or Deimos to predict whether modern mass spectrometry instruments [Mahaffey et al. 2014] would be able to obtain sufficient compositional information to place constraints on their origin. The open source Monte Carlo program SRIM.SR was used to simulate the effect of ions incident onto a surface representing several different meteorite compositions and gave estimates of the damage and sputtering effects. As much of the empirical data supporting SRIM results comes from sputtering of metallic and organic molecular targets which can differ greatly from materials that make up planetary surfaces, measurements of cohesive energies and enthalpies of formation were used to estimate the surface binding energies for minerals, though these can vary significantly depending on the chemical composition. Since these properties affect the sputtering yield, comparisons of simulations with laboratory measurements were made to test the validity of our estimates. Using the validated results and a constant fraction to estimate ion yields, the density of ejected ions and neutrals vs

  15. Comparing linear and non-linear Force Free Models for Flux Rope-Type Small Transients During Solar Maximum

    NASA Astrophysics Data System (ADS)

    Farrugia, Charles; Moestl, Christian; Leitner, Martin; Galvin, Antoinette; Lugaz, Noé; Yu, Wenyuan

    2016-07-01

    This work is about modeling of those small solar wind transients (STs) which have a flux rope geometry. The two models used are: (i) the linear force free solution of Lundquist in terms of Bessel functions, and (ii) the non-linear Gold-Hoyle solution describing a uniformly-twisted flux tube. The first has been used almost exclusively in modeling of both large and small flux ropes in the solar wind. The second was applied to one small transient. In recent work there have been claims that variant (ii) is more appropriate than (i) for large transients, i.e. magnetic clouds. We select by eye six flux rope STs from STEREO and Wind data, chosen purely on the basis of having a large and smooth rotation. We also choose these during solar maximum activity conditions since our current work shows that only then are these models appropriate.

  16. Modeling the performance of small capacity lithium bromide-water absorption chiller operated by solar energy

    SciTech Connect

    Saman, N.F.; Sa`id, W.A.D.K.

    1996-12-31

    An analysis of the performance of a solar operated small capacity (two-ton) Lithium Bromide-Water (LiBr-H{sub 2}O) absorption system is conducted. The analysis is based on the first law of thermodynamics with lithium bromide as the absorbent and water as the refrigerant. The effect of various parameters affecting the machine coefficient of performance under various operating conditions is reported. Coefficient of performance of up to 0.8 can be obtained using flat plate solar collectors with generator temperatures in the range of 80--95 C (176--203 F). Liquid heat exchangers with effectiveness based on an NTU of the order of one would be a good design choice. The chiller can save approximately 3,456 kWh/yr per a two-ton unit, and it will reduce emissions by 19 lb of NO{sub x}, 5,870 lb of CO{sub 2}, and 16 lb of SO{sub x} per year per machine.

  17. Trap states in ZnPc:C60 small-molecule organic solar cells

    NASA Astrophysics Data System (ADS)

    Burtone, Lorenzo; Fischer, Janine; Leo, Karl; Riede, Moritz

    2013-01-01

    Trap states are known to be one of the key parameters limiting charge transport in organic semiconductors and hence the performance of organic solar cells. Here, small-molecule organic solar cells based on a bulk heterojunction between zinc-phtalocyanine (ZnPc) and the fullerene C60 are characterized according to their trapping nature by noninvasive methods and under ambient conditions. We show how impedance spectroscopy, applied to systematically varied device structures, reveals the trap localization as well as its occupation mechanisms. Further insight is given from investigations of different device working points and illumination intensities. Thus, we find the traps to be bulk states in the active layer with an electron-trapping nature. They can be described by a Gaussian energy distribution of 55 meV width, centered at 0.46 eV below the electron transport level and with a concentration of 3.5 × 1016 cm-3. Moreover, the trap states act as recombination centers in the presence of injected or photogenerated charge carriers. The results are confirmed by electrical simulations.

  18. Hard X-ray Detectability of Small Impulsive Heating Events in the Solar Corona

    NASA Astrophysics Data System (ADS)

    Glesener, L.; Klimchuk, J. A.; Bradshaw, S. J.; Marsh, A.; Krucker, S.; Christe, S.

    2015-12-01

    Impulsive heating events ("nanoflares") are a candidate to supply the solar corona with its ~2 MK temperature. These transient events can be studied using extreme ultraviolet and soft X-ray observations, among others. However, the impulsive events may occur in tenuous loops on small enough timescales that the heating is essentially not observed due to ionization timescales, and only the cooling phase is observed. Bremsstrahlung hard X-rays could serve as a more direct and prompt indicator of transient heating events. A hard X-ray spacecraft based on the direct-focusing technology pioneered by the Focusing Optics X-ray Solar Imager (FOXSI) sounding rocket could search for these direct signatures. In this work, we use the hydrodynamical EBTEL code to simulate differential emission measures produced by individual heating events and by ensembles of such events. We then directly predict hard X-ray spectra and consider their observability by a future spaceborne FOXSI, and also by the RHESSI and NuSTAR spacecraft.

  19. The Focusing Optics X-ray Solar Imager Small Explorer Concept Mission

    NASA Astrophysics Data System (ADS)

    Christe, Steven; Shih, Albert Y.; Dennis, Brian R.; Glesener, Lindsay; Krucker, Sam; Saint-Hilaire, Pascal; Gubarev, Mikhail; Ramsey, Brian

    2016-05-01

    We present the FOXSI (Focusing Optics X-ray Solar Imager) small explorer (SMEX) concept, a mission dedicated to studying particle acceleration and energy release on the Sun. FOXSI is designed as a 3-axis stabilized spacecraft in low-Earth orbit making use of state-of-the-art grazing incidence focusing optics combined withpixelated solid-state detectors, allowing for direct imaging of solar X-rays. The current design being studied features multiple telescopes with a 14 meter focal length enabled by a deployable boom.FOXSI will observe the Sun in the 3-100 keV energy range. The FOXSI imaging concept has already been tested on two sounding rocket flights, in 2012 and 2014 and on the HEROES balloon payload flight in 2013. FOXSI will image the Sun with an angular resolution of 5'', a spectral resolution of 0.5 keV, and sub-second temporal resolution. FOXSI is a direct imaging spectrometer with high dynamic range and sensitivity and will provide a brand-new perspective on energy release on the Sun. We describe the mission and its science objectives.

  20. Long-Term Dynamics of Small Bodies in the Solar System

    NASA Technical Reports Server (NTRS)

    Holman, Matthew J.

    2004-01-01

    As part of the NASA Planetary Geology and Geophysics program Prof. Norm Murray (CITA) and I have been conducting investigations of the long-term dynamics of small bodies in the outer solar system. This grant, and its predecessor NAG5- 7761, supports travel for collaboration by the Investigators and also supports Murray during an annual one month visit to the CfA for further collaboration. In the course of this grant we made a number of advances in solar system dynamics. For example, we developed an analytic model for the origin and consequence of chaos associated with three-body resonances in the asteroid belt. This has been shown to be important for the delivery of near Earth objects. We later extended this model to three- body resonances among planets. We were able to show that the numerically identified chaos among the outer planets results from a three-body resonance involving Jupiter, Saturn, and Uranus. The resulting paper was awarded the 1999 Newcomb Cleveland award from the AAAS. This award singles out one paper published in Science each year for distinction.

  1. Long-Term Dynamics of Small Bodies in the Solar System

    NASA Technical Reports Server (NTRS)

    Holman, Matthew J.; Grant, John (Technical Monitor)

    2002-01-01

    As part of the NASA Planetary Geology and Geophysics program, Prof. Norm Murray (CITA (Canadian Institute of Theoretical Astrophysics)) and I have been conducting investigations of the long-term dynamics of small bodies in the outer solar system. This grant, and its successor NAG5-10365, supports travel for collaboration by the Investigators and also supports Murray during an annual one month visit to the CfA (Harvard-Smithsonian Center for Astrophysics) for further collaboration. In the course of this grant we made a number of advances in solar system dynamics. For example, we developed an analytic model for the origin and consequence of chaos associated with three-body resonances in the asteroid belt. This has been shown to be important for the delivery of near Earth objects (NEO). We later extended this model to three-body resonances among planets. We were able to show that the numerically identified chaos among the outer planets results from a three-body resonance involving Jupiter, Saturn, and Uranus. The resulting paper was awarded the 1999 Newcomb Cleveland award from the AAAS (American Association for the Advancement of Science). This award singles out one paper published in Science each year for distinction. A list of grant-related publications is presented, with abstracts included.

  2. Validating SESAME Equations of State for Use in Hydrocode Models of Small Solar System Bodies

    NASA Astrophysics Data System (ADS)

    Catherine, Plesko; Ferguson, Jim; Gisler, Galen R.; Weaver, Robert P.

    2014-11-01

    Hydrodynamic models of small solar system body impacts, collisions, and hazard mitigation require material-specific equations of state (EOS's) in order to close the system of equations that comprise the model and accurately predict the response of such objects to shocks and other hydrodynamic phenomena. Current models approximate meteoritic and cometary materials using Earth-analogue EOS's, e.g., quartz, dunite, hydrated tuff, water ice, and numerical convolutions of analog EOS's. Earth-analogues are used because the formulation of a comprehensive equation of state requires a large amount of experimental data that is destructive to the often rare samples. Analogue EOS's can, however, perform very differently from the original material under shock loading. Some experimental data has become available over time for various meteorite types. Here we compare the available shock data for meteoritic materials to analogue EOS's available in the public Los Alamos National Laboratory SESAME EOS database to explore the applicability and limitations of these models.

  3. Interaction of Convection and Small-scale Magnetic Fields: Influence on the Solar Luminosity

    NASA Technical Reports Server (NTRS)

    Nordlund, A.

    1984-01-01

    Changes in the local solar luminosity due to the presence of a small scale structured (facular) magnetic field in the photosphere are discussed. The discussion is based on three dimensional numerical simulations of the magnetohydrodynamics of the top of the convection zone, and the adjacent stable photosphere. The simulations demonstrate that practically all of the magnetic flux present is concentrated into intense magnetic flux structures, such that the magnetic field pressure is balanced by the gas pressure of the surrounding plasma. The flux concentration is caused by the convectively unstable stratification. The average luminosity of the area is influenced by three effects: (1) the brightness of the flux concentrations, (2) their filling factor, and (3) the average luminosity of the surrounding plasma.

  4. Stable inverted small molecular organic solar cells using a p-doped optical spacer.

    PubMed

    Lee, Sang-Hoon; Seo, Ji-Won; Lee, Jung-Yong

    2015-01-01

    We report inverted small molecular organic solar cells using a doped window layer as an optical spacer. The optical spacer was used to shift the optical field distribution inside the active layers, generating more charge carriers from sunlight. In this report, N,N,N',N'-tetrakis(4-methoxyphenyl)-benzidine (MeO-TPD) was doped with 2,2-(perfluoronaphthalene-2,6-diylidene)dimalononitrile (F6-TCNNQ), a p-type dopant material. P-doped MeO-TPD was adopted as an optical spacer because it has a large energy band gap, and its conductivity can be increased by several orders of magnitude through a doping process. As a result, a power conversion efficiency of 4.15% was achieved with the doped window layer of optimized thickness. Lastly, we present significantly improved stability of the inverted devices with the MeO-TPD layer. PMID:25407588

  5. Efficiency enhancement in solution-processed organic small molecule: Fullerene solar cells via solvent vapor annealing

    NASA Astrophysics Data System (ADS)

    Miao, Jingsheng; Chen, Hui; Liu, Feng; Zhao, Baofeng; Hu, Lingyu; He, Zhicai; Wu, Hongbin

    2015-05-01

    We report highly efficient small molecule solar cells (SMSCs) by using dichloromethane solvent vapor annealing method. The resulted devices delivered a power conversion efficiency (PCE) of 8.3%, which is among the highest in SMSCs. Comparing to the control devices, the short circuit current (Jsc), fill factor, and PCE of solvent vapor annealed devices are significantly improved. Summarizing the results of optical absorption, film morphology, and charge carrier transporting properties, we see that the enhanced structure order and reduced size of phase separation are major reasons for the improved device performances, establishing a solid structure-property relationship. The solvent vapor annealing method can thus be a useful method in device fabrication to enhance performances of SMSCs.

  6. Identification and characterisation of small-scale heating events in the solar atmosphere from 3D MHD simulations

    NASA Astrophysics Data System (ADS)

    Guerreiro, Nuno; Haberreiter, Margit; Hansteen, Viggo; Schmutz, Werner

    2015-04-01

    We study the properties of the small-scale heating events in the solar atmosphere in the nano flare and micro flare energy scale using 3D MHD simulations. We put forward a method to identify and track the heating events in time to study their life times, frequency distributions and spectral signatures. These results aim to better understand the observations from future space missions such as the EUI and SPICE instruments onboard Solar Orbiter and improve our knowledge of the role of small-scale heating events in the heating of the corona.

  7. Space Solar Power Satellite Systems, Modern Small Satellites, and Space Rectenna

    NASA Astrophysics Data System (ADS)

    Bergsrud, Corey Alexis Marvin

    Space solar power satellite (SSPS) systems is the concept of placing large satellite into geostationary Earth orbit (GEO) to harvest and convert massive amounts of solar energy into microwave energy, and to transmit the microwaves to a rectifying antenna (rectenna) array on Earth. The rectenna array captures and converts the microwave power into usable power that is injected into the terrestrial electric grid for use. This work approached the microwave power beam as an additional source of power (with solar) for lower orbiting satellites. Assuming the concept of retrodirectivity, a GEO-SSPS antenna array system tracks and delivers microwave power to lower orbiting satellites. The lower orbiting satellites are equipped with a stacked photovoltaic (PV)/rectenna array hybrid power generation unit (HPGU) in order to harvest solar and/or microwave energy for on-board use during orbit. The area, and mass of the PV array part of the HPGU was reduced at about 32% beginning-of-life power in order to achieve the spacecraft power requirements. The HPGU proved to offer a mass decrease in the PGU, and an increase in mission life due to longer living component life of the rectenna array. Moreover, greater mission flexibility is achieved through a track and power delivery concept. To validate the potential advantages offered by a HPGU, a mission concept was presented that utilizes modern small satellites as technology demonstrators. During launch, a smaller power receiving "daughter" satellite sits inside a larger power transmitting "mother" satellite. Once separated from the launch vehicle the daughter satellite is ejected away from the mother satellite, and each satellite deploys its respective power transmitting or power receiving hardware's for experimentation. The concept of close proximity mission operations between the satellites is considered. To validate the technology of the space rectenna array part of the HPGU, six milestones were completed in the design. The first

  8. Amino Acid Chemistry as a Link Between Small Solar System Bodies and Carbonaceous Chondrites

    NASA Technical Reports Server (NTRS)

    Glavin, Daniel P.; Ehrenfreund, Pascale; Botta, Oliver; Cooper, George; Bada, Jeffrey L.

    2000-01-01

    Establishing chemical links between meteorites and small solar system bodies, such as comets and asteroids, provides a tool for investigating the processes that occurred during the formation of the solar system. Carbonaceous meteorites are of particular interest, since they may have seeded the early Earth with a variety of prebiotic organic compounds including amino acids, purines and pyrimidines, which are thought to be necessary for the origin of life. Here we report the results of high-performance liquid chromatography (HPLC) based amino acid analyses of the acid-hydrolyzed hot water extracts from pristine interior pieces of the CI carbonaceous chondrites Orgueil and Ivuna and the CM meteorites Murchison and Murray. We found that the CI meteorites Orgueil and Ivuna contained high abundances of beta-alanine and glycine, while only traces of other amino acids like alanine, alpha-amino-n-butryic acid (ABA) and alpha-aminoisobutyric acid (AIB) were detected in these meteorites. Carbon isotopic measurements of beta-alanine and glycine in Orgueil by gas chromatography combustion-isotope ratio mass spectrometry clearly indicate an extraterrestrial origin of these amino acids. The amino acid composition of Orgueil and Ivuna was strikingly different from the CM chondrites Murchison and Murray. The most notable difference was the high relative abundance of B-alanine in Orgueil and Ivuna compared to Murchison and Murray. Furthermore, AIB, which is one of the most abundant amino acids found in Murchison and Murray, was present in only trace amounts in Orgueil and Ivuna. Our amino acid data strongly suggest that the CI meteorites Orgueil and Ivuna came from a different type of parent body than the CM meteorites Murchison and Murray, possibly from an extinct comet. It is generally thought that carbonaceous meteorites are fragments of larger asteroidal bodies delivered via near Earth objects (NEO). Orbital and dynamic studies suggest that both fragments of main belt asteroids

  9. Alteration of Organic Compounds in Small Bodies and Cosmic Dusts by Cosmic Rays and Solar Radiation

    NASA Astrophysics Data System (ADS)

    Kobayashi, Kensei; Kaneko, Takeo; Mita, Hajime; Obayashi, Yumiko; Takahashi, Jun-ichi; Sarker, Palash K.; Kawamoto, Yukinori; Okabe, Takuto; Eto, Midori; Kanda, Kazuhiro

    2012-07-01

    A wide variety of complex organic compounds have been detected in extraterrestrial bodies like carbonaceous chondrites and comets, and their roles in the generation of terrestrial life are discussed. It was suggested that organics in small bodies were originally formed in ice mantles of interstellar dusts in dense cloud. Irradiation of frozen mixture of possible interstellar molecules including CO (or CH _{3}OH), NH _{3} and H _{2}O with high-energy particles gave complex amino acid precursors with high molecular weights [1]. Such complex organic molecules were taken in planetesimals or comets in the early solar system. In prior to the generation of the terrestrial life, extraterrestrial organics were delivered to the primitive Earth by such small bodies as meteorites, comets and space dusts. These organics would have been altered by cosmic rays and solar radiation (UV, X-rays) before the delivery to the Earth. We examined possible alteration of amino acids, their precursors and nucleic acid bases in interplanetary space by irradiation with high energy photons and heavy ions. A mixture of CO, NH _{3} and H _{2}O was irradiated with high-energy protons from a van de Graaff accelerator (TIT, Japan). The resulting products (hereafter referred to as CAW) are complex precursors of amino acids. CAW, amino acids (dl-Isovaline, glycine), hydantoins (amino acid precursors) and nucleic acid bases were irradiated with continuous emission (soft X-rays to IR; hereafter referred to as soft X-rays irradiation) from BL-6 of NewSUBARU synchrotron radiation facility (Univ. Hyogo). They were also irradiated with heavy ions (eg., 290 MeV/u C ^{6+}) from HIMAC accelerator (NIRS, Japan). After soft X-rays irradiation, water insoluble materials were formed. After irradiation with soft X-rays or heavy ions, amino acid precursors (CAW and hydantoins) gave higher ratio of amino acids were recovered after hydrolysis than free amino acids. Nucleic acid bases showed higher stability than free

  10. Assessment of Rankine cycle heat engines for small solar power applications

    SciTech Connect

    Meador, J.T.

    1983-11-01

    Performance evaluations of both ideal and actual Organic Rankine Cycles (ORC) and Steam Rankine Cycles (SRC) are made for systems, either available or being developed, that may be candidates in Solar Total Energy Systems (STES). Many organic fluids and turbines (or expanders), especially designed for ORCs, are being used in various current development programs. Only a few representative ORCs are evaluated. Some of the SRCs used with relatively small commercially available steam expanders are also evaluated. Most of the near term development projects of a STES probably will be relatively small, dispersed power, community size installations; therefore the electrical power outputs included range from 200 kW to 10 MW, with maximum cycle temperatures of 482/sup 0/C (900/sup 0/F). Some basic Rankine cycle efficiencies, without recuperation, resuperheating or feedwater heating, are evaluated and compared to Carnot cycle efficiencies when operating between the same limiting temperatures. The thermodynamic processes of a Toluene-ORC and a SRC are studied, including both isentropic (ideal) and actual expansions. Some actual organic and steam Rankine cycle efficiencies are compared to the criterion curves. Some estimates are also make of the potential improvements in performance due to addition of a recuperative heat exchanger and feedwater heaters for the ORCs and the SRCs, respectively.

  11. Fullerene-free small molecule organic solar cells with a high open circuit voltage of 1.15 V.

    PubMed

    Ni, Wang; Li, Miaomiao; Kan, Bin; Liu, Feng; Wan, Xiangjian; Zhang, Qian; Zhang, Hongtao; Russell, Thomas P; Chen, Yongsheng

    2016-01-11

    A new small molecule named DTBTF with thiobarbituric acid as a terminal group was designed and synthesized as an acceptor for organic photovoltaic applications. DTBTF exhibits strong absorption in the visible region, and a relatively high lying LUMO energy level (-3.62 eV). All-small-molecule organic solar cells based on DR3TSBDT:DTBTF blend films show a considerable PCE of 3.84% with a high V(oc) of 1.15 V. PMID:26538446

  12. Small-scale dynamo magnetism as the driver for heating the solar atmosphere

    NASA Astrophysics Data System (ADS)

    Amari, Tahar; Luciani, Jean-François; Aly, Jean-Jacques

    2015-06-01

    The long-standing problem of how the solar atmosphere is heated has been addressed by many theoretical studies, which have stressed the relevance of two specific mechanisms, involving magnetic reconnection and waves, as well as the necessity of treating the chromosphere and corona together. But a fully consistent model has not yet been constructed and debate continues, in particular about the possibility of coronal plasma being heated by energetic phenomena observed in the chromosphere. Here we report modelling of the heating of the quiet Sun, in which magnetic fields are generated by a subphotospheric fluid dynamo intrinsically connected to granulation. We find that the fields expand into the chromosphere, where plasma is heated at the rate required to match observations (4,500 watts per square metre) by small-scale eruptions that release magnetic energy and drive sonic motions. Some energetic eruptions can even reach heights of 10 million metres above the surface of the Sun, thereby affecting the very low corona. Extending the model by also taking into account the vertical weak network magnetic field allows for the existence of a mechanism able to heat the corona above, while leaving unchanged the physics of chromospheric eruptions. Such a mechanism rests on the eventual dissipation of Alfvén waves generated inside the chromosphere and that carry upwards the required energy flux of 300 watts per square metre. The model shows a topologically complex magnetic field of 160 gauss on the Sun's surface, agreeing with inferences obtained from spectropolarimetric observations, chromospheric features (contributing only weakly to the coronal heating) that can be identified with observed spicules and blinkers, and vortices that may be possibly associated with observed solar tornadoes.

  13. Small-scale dynamo magnetism as the driver for heating the solar atmosphere.

    PubMed

    Amari, Tahar; Luciani, Jean-François; Aly, Jean-Jacques

    2015-06-11

    The long-standing problem of how the solar atmosphere is heated has been addressed by many theoretical studies, which have stressed the relevance of two specific mechanisms, involving magnetic reconnection and waves, as well as the necessity of treating the chromosphere and corona together. But a fully consistent model has not yet been constructed and debate continues, in particular about the possibility of coronal plasma being heated by energetic phenomena observed in the chromosphere. Here we report modelling of the heating of the quiet Sun, in which magnetic fields are generated by a subphotospheric fluid dynamo intrinsically connected to granulation. We find that the fields expand into the chromosphere, where plasma is heated at the rate required to match observations (4,500 watts per square metre) by small-scale eruptions that release magnetic energy and drive sonic motions. Some energetic eruptions can even reach heights of 10 million metres above the surface of the Sun, thereby affecting the very low corona. Extending the model by also taking into account the vertical weak network magnetic field allows for the existence of a mechanism able to heat the corona above, while leaving unchanged the physics of chromospheric eruptions. Such a mechanism rests on the eventual dissipation of Alfvén waves generated inside the chromosphere and that carry upwards the required energy flux of 300 watts per square metre. The model shows a topologically complex magnetic field of 160 gauss on the Sun's surface, agreeing with inferences obtained from spectropolarimetric observations, chromospheric features (contributing only weakly to the coronal heating) that can be identified with observed spicules and blinkers, and vortices that may be possibly associated with observed solar tornadoes. PMID:26062509

  14. Design peculiarities prospects of the use of small-size low power RTG for investigating planets and small bodies of the solar system

    NASA Astrophysics Data System (ADS)

    Pustovalov, A. A.; Gusev, V. V.; Pankin, M. I.

    1998-01-01

    The paper considers some aspects of the development of the space plutonium-238 radionuclide thermoelectrical generators (RTG) of low power. Such autonomous sources of electrical power can be first be used for electrical supply and heating of the equipment of small stations, penetrators, probes descending on the planets and asteroids, where a low illumination and low temperatures make it difficult to use solar batteries and chemical current sources.

  15. North-south asymmetry in small and large sunspot group activity and violation of even-odd solar cycle rule

    NASA Astrophysics Data System (ADS)

    Javaraiah, J.

    2016-07-01

    According to Gnevyshev-Ohl (G-O) rule an odd-numbered cycle is stronger than its preceding even-numbered cycle. In the modern time the cycle pair (22, 23) violated this rule. By using the combined Greenwich Photoheliographic Results (GPR) and Solar Optical Observing Network (SOON) sunspot group data during the period 1874-2015, and Debrecen Photoheliographic Data (DPD) of sunspot groups during the period 1974-2015, here we have found that the solar cycle pair (22, 23) violated the G-O rule because, besides during cycle 23 a large deficiency of small sunspot groups in both the northern and the southern hemispheres, during cycle 22 a large abundance of small sunspot groups in the southern hemisphere. In the case of large and small sunspot groups the cycle pair (22, 23) violated the G-O rule in the northern and southern hemispheres, respectively, suggesting the north-south asymmetry in solar activity has a significant contribution in the violation of G-O rule. The amplitude of solar cycle 24 is smaller than that of solar cycle 23. However, Coronal Mass Ejections (CMEs) rate in the rising phases of the cycles 23 and 24 are almost same (even slightly large in cycle 24). From both the SOON and the DPD sunspot group data here we have also found that on the average the ratio of the number (counts) of large sunspot groups to the number of small sunspot groups is larger in the rising phase of cycle 24 than that in the corresponding phase of cycle 23. We suggest this could be a potential reason for the aforesaid discrepancy in the CME rates during the rising phases of cycles 23 and 24. These results have significant implication on solar cycle mechanism.

  16. Powering a Home with Just 25 Watts of Solar PV. Super-Efficient Appliances Can Enable Expanded Off-Grid Energy Service Using Small Solar Power Systems

    SciTech Connect

    Phadke, Amol A.; Jacobson, Arne; Park, Won Young; Lee, Ga Rick; Alstone, Peter; Khare, Amit

    2015-04-01

    Highly efficient direct current (DC) appliances have the potential to dramatically increase the affordability of off-grid solar power systems used for rural electrification in developing countries by reducing the size of the systems required. For example, the combined power requirement of a highly efficient color TV, four DC light emitting diode (LED) lamps, a mobile phone charger, and a radio is approximately 18 watts and can be supported by a small solar power system (at 27 watts peak, Wp). Price declines and efficiency advances in LED technology are already enabling rapidly increased use of small off-grid lighting systems in Africa and Asia. Similar progress is also possible for larger household-scale solar home systems that power appliances such as lights, TVs, fans, radios, and mobile phones. When super-efficient appliances are used, the total cost of solar home systems and their associated appliances can be reduced by as much as 50%. The results vary according to the appliances used with the system. These findings have critical relevance for efforts to provide modern energy services to the 1.2 billion people worldwide without access to the electrical grid and one billion more with unreliable access. However, policy and market support are needed to realize rapid adoption of super-efficient appliances.

  17. Marco Polo: International Small Solar System Body Exploration Mission in 2010's

    NASA Astrophysics Data System (ADS)

    Yano, Hajime

    Since 2000, Japanese scientists and engineers have investigated new generation primitive body missions in the post-Hayabusa era in 2010's. Receiving the Minorbody Exploration Forum Final Report, ISAS established the nation-wide Small Body Exploration Working Group (SBE-WG) in 2004. After the successful exploration of the S-type NEO Itokawa by Hayabusa in 2005, the Hayabusa-2 concept emerged for a C-type asteroid sample return by the original Hayabusa spacecraft system with minor improvements and modifications. In parallel to that effort, the SBE-WG continued to develop the post-Hayabusa mission concept as "Hayabusa Mk-II," a fully model-changed, advanced spacecraft with the sample return capability from the most primitive bodies of the solar system. It is this Hayabusa Mk-II that has became the foundation of the International small body exploration concept "Marco Polo" since 2006. Jointly proposed to the first call of the ESA Cosmic Vision by scientists from Japan, Europe, and the U.S., the Marco Polo concept was selected as one of the M-class mission candidates for the assessment study phase in the fall of 2007. In 2008, the international joint study team has been created and its mission definitions, system requirements, and target selections are currently under the study. The top-level scientific themes are to decode the solar system formation and evolution in the astrobiology and astromineralogy contexts as one of the most important scientific challenges of 2010's. These themes are sub-divided into several objectives to be achieved by both instruments carried onboard the mother spacecraft (MSC), a large lander, or small hopping rovers and returned samples. The initial mission target candicdates include comet-asteroid transition (CAT) objects, D-type asteroids and C-type binary asteroids in near-Earth orbits. In the baseline scenario, a Soyuz launcher provided by ESA will launch the JAXA-made MSC with sampling and other in-situ science instruments provided by

  18. A "roller-wheel" Pt-containing small molecule that outperforms its polymer analogs in organic solar cells

    DOE PAGESBeta

    He, Wenhan; Wu, Qin; Livshits, Maksim Y.; Dickie, Diane A.; Yang, Jianzhong; Quinnett, Rachel; Rack, Jeffrey R.; Qin, Yang

    2016-05-23

    A novel Pt-bisacetylide small molecule (Pt-SM) featuring “roller-wheel” geometry was synthesized and characterized. When compared with conventional Pt-containing polymers and small molecules having “dumbbell” shaped structures, Pt-SM displays enhanced crystallinity and intermolecular π–π interactions, as well as favorable panchromatic absorption behaviors. Furthermore, organic solar cells (OSCs) employing Pt-SM achieve power conversion efficiencies (PCEs) up to 5.9%, the highest reported so far for Pt-containing polymers and small molecules.

  19. Rational Design of Diketopyrrolopyrrole-Based Small Molecules as Donating Materials for Organic Solar Cells

    PubMed Central

    Jin, Ruifa; Wang, Kai

    2015-01-01

    A series of diketopyrrolopyrrole-based small molecules have been designed to explore their optical, electronic, and charge transport properties as organic solar cell (OSCs) materials. The calculation results showed that the designed molecules can lower the band gap and extend the absorption spectrum towards longer wavelengths. The designed molecules own the large longest wavelength of absorption spectra, the oscillator strength, and absorption region values. The optical, electronic, and charge transport properties of the designed molecules are affected by the introduction of different π-bridges and end groups. We have also predicted the mobility of the designed molecule with the lowest total energies. Our results reveal that the designed molecules are expected to be promising candidates for OSC materials. Additionally, the designed molecules are expected to be promising candidates for electron and/or hole transport materials. On the basis of our results, we suggest that molecules under investigation are suitable donors for [6,6]-phenyl-C61-butyric acid methyl ester (PCBM) and its derivatives as acceptors of OSCs. PMID:26343640

  20. Small Pitch Transition-Edge Sensors with Broadband High Spectral Resolution for Solar Physics

    NASA Technical Reports Server (NTRS)

    Smith, S. J.; Adams, J. S.; Eckart, M. E.; Smith, Adams; Bailey, C. N.; Bandler, S. R.; Chevenak, J. A.; Finkbeiner, F. M.; Kelley, R. L.; Kilbourne, C. A.; Porter, F. S.; Sadleir, J. E.

    2012-01-01

    We are developing small pitch transition-edge sensor (TES) X-ray detectors optimized for solar astronomy. These devices are fabricated on thick Si substrates with embedded Cu heat-sink layer. We use 35 x 35 square micrometers Mo/Au TESs with 4.5 micrometer thick Au absorbers. We have tested devices with different geometric absorber stem contact areas with the TES and surrounding substrate area. This allows us to investigate the loss of athermal phonons to the substrate. Results show a correlation between thc stem contact area and a broadening in the spectral line shape indicative of athermal phonon loss. When the contact area is minimized we have obtained exceptional broadband spectral resolution of 1.28 plus or minus 0.03 eV at an energy of 1.5 keV, 1.58 plus or minus 0.07 eV at 5.9 keV and 1.96 plus or minus 0.08 eV at 8 keV. The linearity in the measured gain scale is understood in the context of the longitudinal proximity effect from the electrical bias leads resulting in transition characteristics that are strongly dependent upon TES size.

  1. Energetic Ion Acceleration by Small-scale Solar Wind Flux Ropes

    NASA Astrophysics Data System (ADS)

    le Roux, J. A.; Webb, G. M.; Zank, G. P.; Khabarova, O.

    2015-09-01

    We consider different limits of our recently developed kinetic transport theory to investigate the potential of supersonic solar wind regions containing several small-scale flux ropes to explain the acceleration of suprathermal ions to power-law spectra as observations show. Particle acceleration is modeled in response to flux-rope activity involving contraction, merging (reconnection), and collisions in the limit where the particle gyoradius is smaller than the characteristic flux-rope scale length. The emphasis is mainly on the statistical variance in the electric fields induced by flux-rope dynamics rather than on the mean electric field induced by multiple flux ropes whose acceleration effects are discussed elsewhere. Our steady-state analytical solutions suggest that ion drift acceleration by flux ropes, irrespective of whether displaying incompressible or compressible behavior, can yield power laws asymptotically at higher energies whereas an exponential spectral rollover results asymptotically when field-aligned guiding center motion acceleration occur by reconnection electric fields from merging flux ropes. This implies that at sufficiently high particle energies, drift acceleration might dominate. We also expect compressive flux ropes to yield harder power-law spectra than incompressible flux ropes.

  2. Assessment of solar options for small power systems applications. Volume III. Analysis of concepts

    SciTech Connect

    Laity, W.W.; Aase, D.T.; Apley, W.J.; Bird, S.P.; Drost, M.K.; Garrett-Price, B.A.; Williams, T.A.

    1980-09-01

    A comparative analysis of solar thermal conversion concepts that are potentially suitable for development as small electric power systems (1 to 10 MWe) is given. Seven generic types of collectors, together with associated subsystems for electric power generation, were considered. The collectors can be classified into three categories: (1) two-axis tracking (with compound-curvature reflecting surfaces; (2) one-axis tracking (with single-curvature reflecting suraces; and (3) nontracking (with low-concentration reflecting surfaces). All seven collectors were analyzed in conceptual system configurations with Rankine-cycle engines. In addition, two of the collectors (the Point Focus Central Receiver and the Point Focus Distributed Receiver) were analyzed with Brayton-cycle engines, and the latter of the two also was analyzed with Stirling-cycle engines. This volume describes the systems analyses performed on all the alternative configurations of the seven generic collector concepts and the results obtained. The SOLSTEP computer code used to determine each configuration's system cost and performance is briefly described. The collector and receiver performance calculations used are also presented. The capital investment and related costs that were obtained from the systems studies are presented, and the levelized energy costs are given as a function of capacity factor obtained from the systems studies. Included also are the values of the other attributes used in the concepts' final ranking. The comments, conclusions, and recommendations developed by the PNL study team during the concept characterization and systems analysis tasks of the study are presented. (WHK)

  3. Small Scale Dynamo Magnetism And the Heating of the Quiet Sun Solar Atmosphere.

    NASA Astrophysics Data System (ADS)

    Amari, T.

    2015-12-01

    The longstanding problem of the solar atmosphere heating has been addressed by many theoretical studies. Two specific mechanisms have been shown to play a key role in those : magnetic reconnection and waves. On the other hand the necessity of treating together chromosphere and corona has also been been stressed, with debates going on about the possibility of heating coronal plasma by energetic phenomena observed in the chromosphere,based on many key observations such as spicules, tornadoes…. We present some recent results about the modeling of quiet Sun heating in which magnetic fields are generated by a subphotospheric fluid dynamo which is connected to granulation. The model shows a topologically complex magnetic field of 160 G on the Sun's surface, agreeing with inferences obtained from spectropolarimetric observations.Those generated magnetic fields emerge into the chromosphere, providing the required energy flux and then small-scale eruptions releasing magnetic energy and driving sonic motions. Some of the more energetic eruptions can affect the very low corona only.It is also found that taking into account a vertical weak network magnetic field then allows to provide energy higher in the corona, while leaving unchanged the physics of chromospheric eruptions. The coronal heating mechanism rests on the eventual dissipation of Alfven waves generated inside the chromosphere and carrying upwards an adequate energy flux, while more energetic phenomena contribute only weakly to the heating of the corona.

  4. Rational Design of Diketopyrrolopyrrole-Based Small Moleculesas Donating Materials for Organic Solar Cells.

    PubMed

    Jin, Ruifa; Wang, Kai

    2015-01-01

    A series of diketopyrrolopyrrole-based small molecules have been designed to explore their optical, electronic, and charge transport properties as organic solar cell(OSCs) materials. The calculation results showed that the designed molecules can lower the band gap and extend the absorption spectrum towards longer wavelengths.The designed molecules own the large longest wavelength of absorption spectra,the oscillator strength, and absorption region values. The optical, electronic, and charge transport properties of the designed molecules are affected by the introduction of different π-bridges and end groups. We have also predicted the mobility of the designed molecule with the lowest total energies. Our results reveal that the designed molecules are expected to be promising candidates for OSC materials. Additionally, the designed molecules are expected to be promising candidates for electron and/or hole transport materials. On the basis of our results, we suggest that molecules under investigation are suitable donors for[6,6]-phenyl-C61-butyric acid methyl ester (PCBM) and its derivatives as acceptors of OSCs. PMID:26343640

  5. STARDUST and HAYABUSA: Sample Return Missions to Small Bodies in the Solar System

    NASA Technical Reports Server (NTRS)

    Sandford, S. A.

    2005-01-01

    There are currently two active spacecraft missions designed to return samples to Earth from small bodies in our Solar System. STARDUST will return samples from the comet Wild 2, and HAYABUSA will return samples from the asteroid Itokawa. On January 3,2004, the STARDUST spacecraft made the closest ever flyby (236 km) of the nucleus of a comet - Comet Wild 2. During the flyby the spacecraft collected samples of dust from the coma of the comet. These samples will be returned to Earth on January 15,2006. After a brief preliminary examination to establish the nature of the returned samples, they will be made available to the general scientific community for study. The HAYABUSA spacecraft arrived at the Near Earth Asteroid Itokawa in September 2005 and is currently involved in taking remote sensing data from the asteroid. Several practice landings have been made and a sample collection landing will be made soon. The collected sample will be returned to Earth in June 2007. During my talk I will discuss the scientific goals of the STARDUST and HAYABUSA missions and provide an overview of their designs and flights to date. I will also show some of the exciting data returned by these spacecraft during their encounters with their target objects.

  6. Efficient solution-processed small molecule: Cadmium selenide quantum dot bulk heterojunction solar cells

    SciTech Connect

    Gupta, Vinay; Upreti, Tanvi; Chand, Suresh

    2013-12-16

    We report bulk heterojunction solar cells based on blends of solution-processed small molecule [7,7′-(4,4-bis(2-ethylhexyl)-4H-silolo[3,2-b:4,5-b′]dithiophene-2,6-diyl) bis(6-fluoro-4-(5′-hexyl-[2,2′-bithiophen]-5yl)benzo[c] [1,2,5] thiadiazole)] p-DTS(FBTTh{sub 2}){sub 2}: Cadmium Selenide (CdSe) (70:30, 60:40, 50:50, and 40:60) in the device configuration: Indium Tin Oxide /poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS)/p-DTS(FBTTh{sub 2}){sub 2}: CdSe/Ca/Al. The optimized ratio of p-DTS(FBTTh{sub 2}){sub 2}:CdSe::60:40 leads to a short circuit current density (J{sub sc}) = 5.45 mA/cm{sup 2}, open circuit voltage (V{sub oc}) = 0.727 V, and fill factor (FF) = 51%, and a power conversion efficiency = 2.02% at 100 mW/cm{sup 2} under AM1.5G illumination. The J{sub sc} and FF are sensitive to the ratio of p-DTS(FBTTh{sub 2}){sub 2}:CdSe, which is a crucial factor for the device performance.

  7. MAGNETIC RECONNECTION BETWEEN SMALL-SCALE LOOPS OBSERVED WITH THE NEW VACUUM SOLAR TELESCOPE

    SciTech Connect

    Yang, Shuhong; Zhang, Jun; Xiang, Yongyuan

    2015-01-01

    Using the high tempo-spatial resolution Hα images observed with the New Vacuum Solar Telescope, we report solid observational evidence of magnetic reconnection between two sets of small-scale, anti-parallel loops with an X-shaped topology. The reconnection process contains two steps: a slow step with a duration of more than several tens of minutes, and a rapid step lasting for only about three minutes. During the slow reconnection, two sets of anti-parallel loops gradually reconnect, and new loops are formed and stacked together. During the rapid reconnection, the anti-parallel loops approach each other quickly, and then rapid reconnection takes place, resulting in the disappearance of the former loops. In the meantime, new loops are formed and separate. The region between the approaching loops is brightened, and the thickness and length of this region are determined to be about 420 km and 1.4 Mm, respectively. During the rapid reconnection process, obvious brightenings at the reconnection site and apparent material ejections outward along reconnected loops are observed. These observed signatures are consistent with predictions by reconnection models. We suggest that the successive slow reconnection changes the conditions around the reconnection site and triggers instabilities, thus leading to the rapid approach of the anti-parallel loops and resulting in the rapid reconnection.

  8. Fast charge separation in a non-fullerene organic solar cell with a small driving force

    NASA Astrophysics Data System (ADS)

    Liu, Jing; Chen, Shangshang; Qian, Deping; Gautam, Bhoj; Yang, Guofang; Zhao, Jingbo; Bergqvist, Jonas; Zhang, Fengling; Ma, Wei; Ade, Harald; Inganäs, Olle; Gundogdu, Kenan; Gao, Feng; Yan, He

    2016-07-01

    Fast and efficient charge separation is essential to achieve high power conversion efficiency in organic solar cells (OSCs). In state-of-the-art OSCs, this is usually achieved by a significant driving force, defined as the offset between the bandgap (Egap) of the donor/acceptor materials and the energy of the charge transfer (CT) state (ECT), which is typically greater than 0.3 eV. The large driving force causes a relatively large voltage loss that hinders performance. Here, we report non-fullerene OSCs that exhibit ultrafast and efficient charge separation despite a negligible driving force, as ECT is nearly identical to Egap. Moreover, the small driving force is found to have minimal detrimental effects on charge transfer dynamics of the OSCs. We demonstrate a non-fullerene OSC with 9.5% efficiency and nearly 90% internal quantum efficiency despite a low voltage loss of 0.61 V. This creates a path towards highly efficient OSCs with a low voltage loss.

  9. Assessment of solar options for small power systems applications. Volume V. SOLSTEP: a computer model for solar plant system simulations

    SciTech Connect

    Bird, S.P.

    1980-09-01

    The simulation code, SOLSTEP, was developed at the Pacific Northwest Laboratory to facilitate the evaluation of proposed designs for solar thermal power plants. It allows the user to analyze the thermodynamic and economic performance of a conceptual design for several field size-storage capacity configurations. This feature makes it possible to study the levelized energy cost of a proposed concept over a range of plant capacity factors. The thermodynamic performance is analyzed on a time step basis using actual recorded meteorological and insolation data for specific geographic locations. The flexibility of the model enables the user to analyze both central and distributed generation concepts using either thermal or electric storage systems. The thermodynamic and economic analyses view the plant in a macroscopic manner as a combination of component subsystems. In the thermodynamic simulation, concentrator optical performance is modeled as a function of solar position; other aspects of collector performance can optionally be treated as functions of ambient air temperature, wind speed, and component power level. The power conversion model accounts for the effects of ambient air temperature, partial load operation, auxiliary power demands, and plant standby and startup energy requirements. The code was designed in a modular fashion to provide efficient evaluations of the collector system, total plant, and system economics. SOLSTEP has been used to analyze a variety of solar thermal generic concepts involving several collector types and energy conversion and storage subsystems. The code's straightforward models and modular nature facilitated simple and inexpensive parametric studies of solar thermal power plant performance.

  10. Exciton Dynamics in Alternative Solar Cell Materials: Polymers, Nanocrystals, and Small Molecules

    NASA Astrophysics Data System (ADS)

    Pundsack, Thomas J.

    To keep fossil fuel usage in 2040 even with 2010 usage, 50% of global energy will need to come from alternative sources such as solar cells. While the photovoltaic market is currently dominated by crystalline silicon, there are many low-cost solar cell materials such as conjugated polymers, semiconductor nanocrystals, and organic small molecules which could compete with fossil fuels. To create cost-competitive devices, understanding the excited state dynamics of these materials is necessary. The first section of this thesis looks at aggregation in poly(3-hexylthiophene) (P3HT) which is commonly used in organic photovoltaics. The amount of aggregation in P3HT thin films was controlled by using a mixture of regioregular and regiorandom P3HT. Even with few aggregates present, excited states were found to transfer from amorphous to aggregate domains in <50 fs which could indicate efficient long-range energy transfer. To further study P3HT aggregation, a triblock consisting of two P3HT chains with a coil polymer between them was investigated. By changing solvents, aggregation was induced in a stable and reversible manner allowing for spectroscopic studies of P3HT aggregates in solution. The polarity of the solvent was adjusted, and no change in excited state dynamics was observed implying the excited state has little charge-transfer character. Next, the conduction band density of states for copper zinc tin sulfide nanocrystals (CZTS NCs) was measured using pump-probe spectroscopy and found to be in agreement with theoretical results. The density of states shifted and dilated for smaller NCs indicative of quantum confinement. The excited state lifetime was found to be short (<20 ps) and independent of NC size which could limit the efficiency of CZTS photovoltaic devices. Finally, triplet-triplet annihilation (TTA) was studied in platinum octaethylporphyrin (PtOEP) thin films. By analyzing pump-probe spectra, the product of TTA in PtOEP thin films was assigned to a long

  11. Villacidro solar demo plant: Integration of small-scale CSP and biogas power plants in an industrial microgrid

    NASA Astrophysics Data System (ADS)

    Camerada, M.; Cau, G.; Cocco, D.; Damiano, A.; Demontis, V.; Melis, T.; Musio, M.

    2016-05-01

    The integration of small scale concentrating solar power (CSP) in an industrial district, in order to develop a microgrid fully supplied by renewable energy sources, is presented in this paper. The plant aims to assess in real operating conditions, the performance, the effectiveness and the reliability of small-scale concentrating solar power technologies in the field of distributed generation. In particular, the potentiality of small scale CSP with thermal storage to supply dispatchable electricity to an industrial microgrid will be investigated. The microgrid will be realized in the municipal waste treatment plant of the Industrial Consortium of Villacidro, in southern Sardinia (Italy), which already includes a biogas power plant. In order to achieve the microgrid instantaneous energy balance, the analysis of the time evolution of the waste treatment plant demand and of the generation in the existing power systems has been carried out. This has allowed the design of a suitable CSP plant with thermal storage and an electrochemical storage system for supporting the proposed microgrid. At the aim of obtaining the expected energy autonomy, a specific Energy Management Strategy, which takes into account the different dynamic performances and characteristics of the demand and the generation, has been designed. In this paper, the configuration of the proposed small scale concentrating solar power (CSP) and of its thermal energy storage, based on thermocline principle, is initially described. Finally, a simulation study of the entire power system, imposing scheduled profiles based on weather forecasts, is presented.

  12. SMALL-SCALE PRESSURE-BALANCED STRUCTURES DRIVEN BY OBLIQUE SLOW MODE WAVES MEASURED IN THE SOLAR WIND

    SciTech Connect

    Yao Shuo; He, J.-S.; Tu, C.-Y.; Wang, L.-H.; Marsch, E.

    2013-09-01

    Recently, small-scale pressure-balanced structures (PBSs) were identified in the solar wind, but their formation mechanism remains unclear. This work aims to reveal the dependence of the properties of small-scale PBSs on the background magnetic field (B{sub 0}) direction and thus to corroborate the in situ mechanism that forms them. We analyze the plasma and magnetic field data obtained by WIND in the quiet solar wind at 1 AU. First, we use a developed moving-average method to obtain B{sub 0}(s, t) for every temporal scale (s) at each time moment (t). By wavelet cross-coherence analysis, we obtain the correlation coefficients between the thermal pressure P{sub th} and the magnetic pressure P{sub B}, distributing against the temporal scale and the angle {theta}{sub xB} between B{sub 0}(s, t) and Geocentric Solar Ecliptic coordinates (GSE)-x. We note that the angle coverage of a PBS decreases with shorter temporal scale, but the occurrence of the PBSs is independent of {theta}{sub xB}. Suspecting that the isolated small PBSs are formed by compressive waves in situ, we continue this study by testing the wave modes forming a small-scale PBS with B{sub 0}(s, t) quasi-parallel to GSE-x. As a result, we identify that the cross-helicity and the compressibility attain values for a slow mode from theoretical calculations. The wave vector is derived from minimum variance analysis. Besides, the proton temperatures obey T < T{sub Parallel-To} derived from the velocity distribution functions, excluding a mirror mode, which is the other candidate for the formation of PBSs in situ. Thus, a small-scale PBS is shown to be driven by oblique, slow-mode waves in the solar wind.

  13. 'My body is mine': Qualitatively exploring agency among internally displaced women participants in a small-group intervention in Leogane, Haiti.

    PubMed

    Logie, Carmen H; Daniel, CarolAnn

    2016-01-01

    The 2010 earthquake resulted in the breakdown of Haiti's social, economic and health infrastructure. Over one-quarter of a million people remain internally displaced (ID). ID women experience heightened vulnerability to intimate partner violence (IPV) due to increased poverty and reduced community networks. Scant research has examined experiences of IPV among ID women in post-earthquake Haiti. We conducted a qualitative study to explore the impact of participating in Famn an Aksyon Pou Santé Yo (FASY), a small-group HIV prevention intervention, on ID women's agency in Leogane, Haiti. We conducted four focus groups with ID women, FASY participants (n = 40) and in-depth individual interviews with peer health workers (n = 7). Our study was guided by critical ethnography and paid particular attention to power relations. Findings highlighted multiple forms of IPV (e.g., physical, sexual). Participants discussed processes of intrapersonal (confidence), interpersonal (communication), relational (support) and collective (women's rights) agency. Yet structural factors, including patriarchal gender norms and poverty, silenced IPV discussions and constrained women's agency. Findings suggest that agency among ID women is a multi-level, non-linear and incremental process. To effectively address IPV among ID women in Haiti, interventions should address structural contexts of gender inequity and poverty and concurrently facilitate multi-level processes of agency. PMID:25833376

  14. Small molecular weight organic thin-film photodetectors and solar cells

    NASA Astrophysics Data System (ADS)

    Peumans, Peter; Yakimov, Aharon; Forrest, Stephen R.

    2003-04-01

    In this review, we discuss the physics underlying the operation of single and multiple heterojunction, vacuum-deposited organic solar cells based on small molecular weight thin films. For single heterojunction cells, we find that the need for direct contact between the deposited electrode and the active organics leads to quenching of excitons. An improved device architecture, the double heterojunction, is shown to confine excitons within the active layers, allowing substantially higher internal efficiencies to be achieved. A full optical and electrical analysis of the double heterostructure architecture leads to optimal cell design as a function of the optical properties and exciton diffusion lengths of the photoactive materials. Combining the double heterostructure with novel light trapping schemes, devices with external efficiencies approaching their internal efficiency are obtained. When applied to an organic photovoltaic cell with a power conversion efficiency of 1.0%±0.1% under 1 sun AM1.5 illumination, devices with external power conversion efficiencies of 2.4%±0.3% are reported. In addition, we show that by using materials with extended exciton diffusion lengths LD, highly efficient double heterojunction photovoltaic cells are obtained, even in the absence of a light trapping geometry. Using C60 as an acceptor material, double heterostructure external power conversion efficiencies of 3.6%±0.4% under 1 sun AM1.5 illumination are obtained. Stacking of single heterojunction devices leads to thin film multiple heterojunction photovoltaic and photodetector structures. Thin bilayer photovoltaic cells can be stacked with ultrathin (˜5 Å), discontinuous Ag layers between adjacent cells serving as efficient recombination sites for electrons and holes generated in the neighboring cells. Such stacked cells have open circuit voltages that are n times the open circuit voltage of a single cell, where n is the number of cells in the stack. In optimized structures, the

  15. Small-molecule organic solar cells with multiple-layer donor

    NASA Astrophysics Data System (ADS)

    Arisawa, Kenta; Harafuji, Kenji

    2015-09-01

    Small-molecule organic solar cells (OSCs) with a multifunction three-layer donor are experimentally investigated to achieve higher power conversion efficiency. The proposed OSC has an indium tin oxide (ITO, anode)/three-layer donor/fullerene (C60, acceptor, 40 nm)/bathocuproine (BCP, cathode buffer, 10 nm)/Ag (cathode, 100 nm) structure. The three-layer donor is composed of 3-nm-thick pentacene/20-nm-thick copper phthalocyanine (CuPc)/5-nm-thick aluminum phthalocyanine chloride (ClAlPc). The OSC achieves a power conversion efficiency of 1.79%, which is 1.7 times as large as that for an OSC with a single-layer donor of 20-nm-thick CuPc. Atomic force microscopy observation is carried out to clarify in detail the surface morphology at typical organic layers. The acceptor C60 is in contact not only with ClAlPc but also with CuPc due to the vertical and wall-like growth of the ClAlPc layer. The open-circuit voltage for the OSC with the ClAlPc/C60 contact is 0.56 V, compared with 0.47 V for the OSC with the CuPc/C60 contact. The thin pentacene layer is uniformly grown on the ITO and serves to achieve a high short-circuit current density Jsc by lowering the barrier height for hole transport between ITO and CuPc. Jsc for the OSC with the thin pentacene layer is 5.60 mA/cm2, compared with 4.32 mA/cm2 for the OSC without the thin pentacene layer.

  16. Small-bandgap polymer solar cells with unprecedented short-circuit current density and high fill factor.

    PubMed

    Choi, Hyosung; Ko, Seo-Jin; Kim, Taehyo; Morin, Pierre-Olivier; Walker, Bright; Lee, Byoung Hoon; Leclerc, Mario; Kim, Jin Young; Heeger, Alan J

    2015-06-01

    Small-bandgap polymer solar cells (PSCs) with a thick bulk heterojunction film of 340 nm exhibit high power conversion efficiencies of 9.40% resulting from high short-circuit current density (JSC ) of 20.07 mA cm(-2) and fill factor of 0.70. This remarkable efficiency is attributed to maximized light absorption by the thick active layer and minimized recombination by the optimized lateral and vertical morphology through the processing additive. PMID:25899940

  17. Phase 1 of the First Solar Small Power System Experiment (experimental System No. 1). Volume 3: Appendix E - N

    NASA Technical Reports Server (NTRS)

    Clark, T. B. (Editor)

    1979-01-01

    The design of a solar electric power plant for a small community is reported. Topics covered include: (1) control configurations and interface requirements for the baseline power system; (2) annual small power system output; (3) energy requirements for operation of the collectors and control building; (4) life cycle costs and reliability predictions; (5) thermal conductivities and costs of receiver insulation materials; (6) transient thermal modelling for the baseline receiver/thermal transport system under normal and inclement operating conditions; (7) high temperature use of sodium; (8) shading in a field of parabolic collectors; and (9) buffer storage materials.

  18. Tailoring the interface using thiophene small molecules in TiO2/P3HT hybrid solar cells.

    PubMed

    Freitas, Flavio S; Clifford, John N; Palomares, Emilio; Nogueira, Ana F

    2012-09-14

    In this paper we focus on the effect of carboxylated thiophene small molecules as interface modifiers in TiO(2)/P3HT hybrid solar cells. Our results show that small differences in the chemical structure of these molecules, for example, the presence of the -CH(2)- group in the 2-thiopheneacetic acid (TAA), can greatly increase the TiO(2) surface wettability, improving the TiO(2)/polymer contact. This effect is important to enhance exciton splitting and charge separation. PMID:22842849

  19. The First Phase of the English Regional Development Agencies' Skills Work: A Report on a Small-Scale Research Project.

    ERIC Educational Resources Information Center

    Drodge, Stephen

    A study of three Regional Development Agencies (RDAs) traced development of the skills element of their RES [Regional Economic Strategy] and their progress toward an action plan for skills to implement their strategic objectives. The process involved creating a forum on skills; producing a consultation draft skills strategy; and producing a final…

  20. Lightweight Integrated Solar Array and Transceiver. [Improving Electrical Power and Communication Capabilities in Small Spacecraft

    NASA Technical Reports Server (NTRS)

    Carr, John; Martinez, Andres; Petro, Andrew

    2015-01-01

    The Lightweight Integrated Solar Array and Transceiver (LISA-T) project will leverage several existing and on-going efforts at Marshall Space Flight Center (MSFC) for the design, development, fabrication, and test of a launch stowed, orbit deployed structure on which thin-film photovoltaics for power generation and antenna elements for communication, are embedded. Photovoltaics is a method for converting solar energy into electricity using semiconductor materials. The system will provide higher power generation with a lower mass, smaller stowage volume, and lower cost than the state of the art solar arrays, while simultaneously enabling deployable antenna concepts.

  1. On the prevalence of small-scale twist in the solar chromosphere and transition region

    NASA Astrophysics Data System (ADS)

    De Pontieu, B.; Rouppe van der Voort, L.; McIntosh, S. W.; Pereira, T. M. D.; Carlsson, M.; Hansteen, V.; Skogsrud, H.; Lemen, J.; Title, A.; Boerner, P.; Hurlburt, N.; Tarbell, T. D.; Wuelser, J. P.; De Luca, E. E.; Golub, L.; McKillop, S.; Reeves, K.; Saar, S.; Testa, P.; Tian, H.; Kankelborg, C.; Jaeggli, S.; Kleint, L.; Martinez-Sykora, J.

    2014-10-01

    The solar chromosphere and transition region (TR) form an interface between the Sun’s surface and its hot outer atmosphere. There, most of the nonthermal energy that powers the solar atmosphere is transformed into heat, although the detailed mechanism remains elusive. High-resolution (0.33-arc second) observations with NASA’s Interface Region Imaging Spectrograph (IRIS) reveal a chromosphere and TR that are replete with twist or torsional motions on sub-arc second scales, occurring in active regions, quiet Sun regions, and coronal holes alike. We coordinated observations with the Swedish 1-meter Solar Telescope (SST) to quantify these twisting motions and their association with rapid heating to at least TR temperatures. This view of the interface region provides insight into what heats the low solar atmosphere.

  2. On the prevalence of small-scale twist in the solar chromosphere and transition region.

    PubMed

    De Pontieu, B; van der Voort, L Rouppe; McIntosh, S W; Pereira, T M D; Carlsson, M; Hansteen, V; Skogsrud, H; Lemen, J; Title, A; Boerner, P; Hurlburt, N; Tarbell, T D; Wuelser, J P; De Luca, E E; Golub, L; McKillop, S; Reeves, K; Saar, S; Testa, P; Tian, H; Kankelborg, C; Jaeggli, S; Kleint, L; Martinez-Sykora, J

    2014-10-17

    The solar chromosphere and transition region (TR) form an interface between the Sun's surface and its hot outer atmosphere. There, most of the nonthermal energy that powers the solar atmosphere is transformed into heat, although the detailed mechanism remains elusive. High-resolution (0.33-arc second) observations with NASA's Interface Region Imaging Spectrograph (IRIS) reveal a chromosphere and TR that are replete with twist or torsional motions on sub-arc second scales, occurring in active regions, quiet Sun regions, and coronal holes alike. We coordinated observations with the Swedish 1-meter Solar Telescope (SST) to quantify these twisting motions and their association with rapid heating to at least TR temperatures. This view of the interface region provides insight into what heats the low solar atmosphere. PMID:25324398

  3. Statistical Characterization of Solar Photovoltaic Power Variability at Small Timescales: Preprint

    SciTech Connect

    Shedd, S.; Hodge, B.-M.; Florita, A.; Orwig, K.

    2012-08-01

    Integrating large amounts of variable and uncertain solar photovoltaic power into the electricity grid is a growing concern for power system operators in a number of different regions. Power system operators typically accommodate variability, whether from load, wind, or solar, by carrying reserves that can quickly change their output to match the changes in the solar resource. At timescales in the seconds-to-minutes range, this is known as regulation reserve. Previous studies have shown that increasing the geographic diversity of solar resources can reduce the short term-variability of the power output. As the price of solar has decreased, the emergence of very large PV plants (greater than 10 MW) has become more common. These plants present an interesting case because they are large enough to exhibit some spatial smoothing by themselves. This work examines the variability of solar PV output among different arrays in a large ({approx}50 MW) PV plant in the western United States, including the correlation in power output changes between different arrays, as well as the aggregated plant output, at timescales ranging from one second to five minutes.

  4. Simulation and Evaluation of Small Scale Solar Power Tower Performance under Malaysia Weather Conditions

    NASA Astrophysics Data System (ADS)

    Gamil, A. M.; Gilani, S. I.; Al-Kayiem, H. H.

    2013-06-01

    Solar energy is the most available, clean, and inexpensive source of energy among the other renewable sources of energy. Malaysia is an encouraging location for the development of solar energy systems due to abundant sunshine (10 hours daily with average solar energy received between 1400 and 1900 kWh/m2). In this paper the design of heliostat field of 3 dual-axis heliostat units located in Ipoh, Malaysia is introduced. A mathematical model was developed to estimate the sun position and calculate the cosine losses in the field. The study includes calculating the incident solar power to a fixed target on the tower by analysing the tower height and ground distance between the heliostat and the tower base. The cosine efficiency was found for each heliostat according to the sun movement. TRNSYS software was used to simulate the cosine efficiencies and field hourly incident solar power input to the fixed target. The results show the heliostat field parameters and the total incident solar input to the receiver.

  5. Modeling of Gas and Dust Outflow Dynamics at Active Small Solar System Bodies

    NASA Astrophysics Data System (ADS)

    Fahnestock, Eugene G.

    2013-05-01

    Abstract (2,250 Maximum Characters): We present methodology and results from our recent effort in modeling the gas outflow from the surfaces of primitive/active small solar system bodies, and modeling the dynamics of dust particles entrained by that flow. We based our initial simulation capability on the COMA software package, developed ≈1995-1999 for ESA to enable studies preparatory to Rosetta. Rather than integrate the derived software for gas and dust dynamics simulation "into the loop" within high-fidelity 6DOF integration of a rendezvoused spacecraft's dynamics, we created simple tools, or "interfaces", computationally efficient enough to be brought into the loop, yet capturing the variety of ways in which gas and lifted dust can potentially perturb guidance, navigation, and control (GN&C) performance and surface observation performance. For example, these interfaces are called in the loop to compute noise models for degradation by the dust of imagery and lidar navigation observables. The same applies for degradation of science instrument observations of the surface. Accurate spacecraft dynamics propagation is necessary for mission design, while both that and the observables modeling are required for end-to-end simulation and analysis of navigation and control to the designed close-proximity trajectories. We created interfaces with increasing levels of fidelity, ultimately sufficiently approximating the full flow-field of gas and dust activity; both diffuse background activity (with spatial variation in relation to sun direction) and concentrated jet activity (with spatial and temporal variation through masking to the regions of jet activity in the body-fixed frame and modeling body rotation). We show example results using these tools for two representative design reference missions involving 9P/Tempel 1 and 67P/C-G. This work should be of interest to anyone in the DDA community considering involvement in such mission scenarios. It may also be extended in

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

    NASA Technical Reports Server (NTRS)

    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

  7. Deep absorbing porphyrin small molecule for high-performance organic solar cells with very low energy losses.

    PubMed

    Gao, Ke; Li, Lisheng; Lai, Tianqi; Xiao, Liangang; Huang, Yuan; Huang, Fei; Peng, Junbiao; Cao, Yong; Liu, Feng; Russell, Thomas P; Janssen, René A J; Peng, Xiaobin

    2015-06-17

    We designed and synthesized the DPPEZnP-TEH molecule, with a porphyrin ring linked to two diketopyrrolopyrrole units by ethynylene bridges. The resulting material exhibits a very low energy band gap of 1.37 eV and a broad light absorption to 907 nm. An open-circuit voltage of 0.78 V was obtained in bulk heterojunction (BHJ) organic solar cells, showing a low energy loss of only 0.59 eV, which is the first report that small molecule solar cells show energy losses <0.6 eV. The optimized solar cells show remarkable external quantum efficiency, short circuit current, and power conversion efficiency up to 65%, 16.76 mA/cm(2), and 8.08%, respectively, which are the best values for BHJ solar cells with very low energy losses. Additionally, the morphology of DPPEZnP-TEH neat and blend films with PC61BM was studied thoroughly by grazing incidence X-ray diffraction, resonant soft X-ray scattering, and transmission electron microscopy under different fabrication conditions. PMID:26035342

  8. CHROMOSPHERIC SIGNATURES OF SMALL-SCALE FLUX EMERGENCE AS OBSERVED WITH NEW SOLAR TELESCOPE AND HINODE INSTRUMENTS

    SciTech Connect

    Yurchyshyn, V. B.; Goode, P. R.; Abramenko, V. I.; Chae, J.; Cao, W.; Andic, A.; Ahn, K.

    2010-10-20

    With the ever-increasing influx of high-resolution images of the solar surface obtained at a multitude of wavelengths, various processes occurring at small spatial scales have become a greater focus of our attention. Complex small-scale magnetic fields have been reported that appear to have enough stored energy to heat the chromosphere. While significant progress has been made in understanding small-scale phenomena, many specifics remain elusive. We present here a detailed study of a single event of disappearance of a magnetic dipole and associated chromospheric activity. Based on New Solar Telescope H{alpha} data and Hinode photospheric line-of-sight magnetograms and Ca II H images, we report the following. (1) Our analysis indicates that even very small dipoles (elements separated by about 0.''5 or less) may reach the chromosphere and trigger non-negligible chromospheric activity. (2) Careful consideration of the magnetic environment where the new flux is deposited may shed light on the details of magnetic flux removal from the solar surface. We argue that the apparent collision and disappearance of two opposite polarity elements may not necessarily indicate their cancellation (i.e., reconnection, emergence of a 'U' tube, or submergence of {Omega} loops). In our case, the magnetic dipole disappeared by reconnecting with overlying large-scale inclined plage fields. (3) Bright points (BPs) seen in off-band H{alpha} images are very well correlated with the Ca II H BPs, which in turn are cospatial with G-band BPs. We further speculate that, in general, H{alpha} BPs are expected to be cospatial with photospheric BPs; however, a direct comparison is needed to refine their relationship.

  9. Solar dynamo theory : Solar dynamo theory: a new look at the origin of small-scale magnetic fields

    NASA Astrophysics Data System (ADS)

    Cattaneo, Fausto; Hughes, David W.

    2001-06-01

    Fausto Cattaneo and David W Hughes delve beneath the surface of the Sun with numerical models of turbulent convection. Although magnetic dynamo action is traditionally associated with rotation, fast dynamo theory shows that chaotic flows, even without rotation, can act as efficient small-scale dynamos. Indeed, numerical simulations suggest that granular and supergranular convection may generate locally a substantial part of the field in the quiet photosphere.

  10. Spacecraft/Rover Hybrids for the Exploration of Small Solar System Bodies. [NASA NIAC Phase I Study

    NASA Technical Reports Server (NTRS)

    Pavone, Marco; Castillo-Rogez, Julie C.; Hoffman, Jeffrey A.; Nesnas, Issa A. D.

    2012-01-01

    This study investigated a novel mission architecture for the systematic and affordable in-situ exploration of small Solar System bodies. Specifically, a mother spacecraft would deploy over the surface of a small body one, or several, spacecraft/rover hybrids, which are small, multi-faceted enclosed robots with internal actuation and external spikes. They would be capable of 1) long excursions (by hopping), 2) short traverses to specific locations (through a sequence of controlled tumbles), and 3) high-altitude, attitude-controlled ballistic flight (akin to spacecraft flight). Their control would rely on synergistic operations with the mother spacecraft (where most of hybrids' perception and localization functionalities would be hosted), which would make the platforms minimalistic and, in turn, the entire mission architecture affordable.

  11. A journey of a thousand miles begins with one small step - human agency, hydrological processes and time in socio-hydrology

    NASA Astrophysics Data System (ADS)

    Ertsen, M. W.; Murphy, J. T.; Purdue, L. E.; Zhu, T.

    2014-04-01

    When simulating social action in modeling efforts, as in socio-hydrology, an issue of obvious importance is how to ensure that social action by human agents is well-represented in the analysis and the model. Generally, human decision-making is either modeled on a yearly basis or lumped together as collective social structures. Both responses are problematic, as human decision-making is more complex and organizations are the result of human agency and cannot be used as explanatory forces. A way out of the dilemma of how to include human agency is to go to the largest societal and environmental clustering possible: society itself and climate, with time steps of years or decades. In the paper, another way out is developed: to face human agency squarely, and direct the modeling approach to the agency of individuals and couple this with the lowest appropriate hydrological level and time step. This approach is supported theoretically by the work of Bruno Latour, the French sociologist and philosopher. We discuss irrigation archaeology, as it is in this discipline that the issues of scale and explanatory force are well discussed. The issue is not just what scale to use: it is what scale matters. We argue that understanding the arrangements that permitted the management of irrigation over centuries requires modeling and understanding the small-scale, day-to-day operations and personal interactions upon which they were built. This effort, however, must be informed by the longer-term dynamics, as these provide the context within which human agency is acted out.

  12. A journey of a thousand miles begins with one small step - human agency, hydrological processes and time in socio-hydrology

    NASA Astrophysics Data System (ADS)

    Ertsen, M. W.; Murphy, J. T.; Purdue, L. E.; Zhu, T.

    2013-11-01

    When simulating social action in modeling efforts, as in socio-hydrology, an issue of obvious importance is how to ensure that social action by human agents is well-represented in the analysis and the model. Generally, human decision-making is either modeled on a yearly basis or lumped together as collective social structures. Both responses are problematic, as human decision making is more complex and organizations are the result of human agency and cannot be used as explanatory forces. A way out of the dilemma how to include human agency is to go to the largest societal and environmental clustering possible: society itself and climate, with time steps of years or decades. In the paper, the other way out is developed: to face human agency squarely, and direct the modeling approach to the human agency of individuals and couple this with the lowest appropriate hydrological level and time step. This approach is supported theoretically by the work of Bruno Latour, the French sociologist and philosopher. We discuss irrigation archaeology, as it is in this discipline that the issues of scale and explanatory force are well discussed. The issue is not just what scale to use: it is what scale matters. We argue that understanding the arrangements that permitted the management of irrigation over centuries, requires modeling and understanding the small-scale, day-to-day operations and personal interactions upon which they were built. This effort, however, must be informed by the longer-term dynamics as these provide the context within which human agency, is acted out.

  13. Solar wind interaction with small bodies. 1: Whistler wing signatures near to Gaspra and Ida

    NASA Technical Reports Server (NTRS)

    Wang, Z.; Kivelson, M. G.; Joy, S.; Khurana, K. K.; Polanskey, C.; Southwood, D. J.; Walker, R. J.

    1995-01-01

    Data from Galileo's two asteroid flybys reveal magnetic fluctuations that we interpret as perturbations of the solar wind magnetic field caused by an interaction with the nearby asteroid. The scale sizes of the bodies (approximately 14 km for Gaspra and approximately 30 km for Ida) are intermediate between the ion and electron gyroradii, which implies that the asteroid-imposed perturbations propagate in the whistler mode. Special properties of the whistler mode include phase phase velocities that can exceed the solar wind speed and confinement of the disturbance to directions nearly aligned with the magnetic field. These features of the interaction impose a structure on the solar wind disturbance that differs greatly from the forms familiar for either magnetized or unmagnetized bodies of magnetohydrodynamic spatial scales. We examine both data and computer simulations of the interaction with special attention to what can be inferred about the interaction itself from analysis of the data.

  14. Challenges of Communications and Tracking for Solar System Small Body Exploration

    NASA Technical Reports Server (NTRS)

    Rush, John J.; Lichten, Stephen M.; Srinivasan, Jeffrey M.

    2011-01-01

    This presentation will address: (1) Communications capabilities that will be needed for space missions for Small Planetary Body exploration (2) Utilization of large ground-based radar capabilities for Small Body remote sensing and mission planning

  15. Self operating absorption cooling system using solar energy: Small power experimental plant

    NASA Astrophysics Data System (ADS)

    Velluet, P.; Dehausse, R.

    This study deals with a solar system for refrigeration specially designed for remote areas conditions. So, it must be very simple and reliable, and in addition it must be also mechanically self-operating. The thermodynamic cycle used is an ammonia-water absorption one. It consumes only thermal energy, which is easily and cheaply converted directly from solar radiation. In order to make a self-operating system, an engine is located between the boiler (at high pressure) and the absorber (at low pressure). It expands ammonia vapor and produces mechanical energy to run the solution pump.

  16. Compact Solar Simulator with a Small Subtense Angle and Controlled Magnification Optics

    NASA Technical Reports Server (NTRS)

    Jefferies, Kent S. (Inventor)

    1996-01-01

    The present invention is directed to a method of simulating a pseudosun using a solar simulator. In the present invention the collector and lens of a lamp are designed to properly focus a plurality of light beams onto a segmented turning mirror. The path of light rays are traced from the lamp to the collector and then finally to the lens to control the solid and tangential magnification of the solar simulator. The segmented turning mirror is located at the focal point of the light beam and redirects the light into a vacuum chamber.

  17. Concept definition study of small Brayton cycle engines for dispersed solar electric power systems

    NASA Technical Reports Server (NTRS)

    Six, L. D.; Ashe, T. L.; Dobler, F. X.; Elkins, R. T.

    1980-01-01

    Three first-generation Brayton cycle engine types were studied for solar application: a near-term open cycle (configuration A), a near-term closed cycle (configuration B), and a longer-term open cycle (configuration C). A parametric performance analysis was carried out to select engine designs for the three configurations. The interface requirements for the Brayton cycle engine/generator and solar receivers were determined. A technology assessment was then carried out to define production costs, durability, and growth potential for the selected engine types.

  18. Morphological study on small molecule acceptor-based organic solar cells with efficiencies beyond 7% (Presentation Recording)

    NASA Astrophysics Data System (ADS)

    Ma, Wei; Yan, He

    2015-10-01

    Despite the essential role of fullerenes in achieving best-performance organic solar cells (OSCs), fullerene acceptors have several drawbacks including poor light absorption, high-cost production and purification. For this reason, small molecule acceptor (SMA)-based OSCs have attracted much attention due to the easy tunability of electronic and optical properties of SMA materials. In this study, polymers with temperature dependent aggregation behaviors are combined with various small molecule acceptor materials, which lead to impressive power conversion efficiencies of up to 7.3%. The morphological and aggregation properties of the polymer:small molecule blends are studied in details. It is found that the temperature-dependent aggregation behavior of polymers allows for the processing of the polymer solutions at moderately elevated temperature, and more importantly, controlled aggregation and strong crystallization of the polymer during the film cooling and drying process. This results in a well-controlled and near-ideal polymer:small molecule morphology that is controlled by polymer aggregation during warm casting and thus insensitive to the choice of small molecules. As a result, several cases of highly efficient (PCE between 6-7.3%) SMA OSCs are achieved. The second part of this presentation will describe the morphology of a new small molecule acceptor with a unique 3D structure. The relationship between molecular structure and morphology is revealed.

  19. Synergistic Effects of Morphological Control and Complementary Absorption in Efficient All-Small-Molecule Ternary-Blend Solar Cells.

    PubMed

    Farahat, Mahmoud E; Patra, Dhananjaya; Lee, Chih-Hao; Chu, Chih-Wei

    2015-10-14

    In this study, we combined two small-molecule donors-a diketopyrrolopyrrole-based small molecule (SMD) and a benzodithiophene-based molecule (BDT6T)-with [6,6]-phenyl-C61-butyric acid methyl ester (PC61BM) to form ternary blend solar cells. The power conversion efficiency of the binary SMD:PC61BM bulk heterojunction solar cell improved from 4.57 to 6.28% after adding an appropriate amount BDT6T as a guest. We attribute this 37% improvement in device performance to the complementary absorption behavior of BDT6T and SMD, as evidenced by the increase in the short circuit current. After addition of BDT6T to form the ternary blend, the crystallinity and morphology of the active layer were enhanced. For example, the features observed in the ternary active layers were finer than those in the binary blends. This means that BDT6T as a third component in the ternary blend has effective role on both the absorption and the morphology. In addition, adding BDT6T to form the ternary blend also led to an increase in the open-circuit voltage. Our findings suggest that the preparation of such simple all-small-molecule ternary blends can be an effective means of improving the efficiency of photovoltaic devices. PMID:26389528

  20. Performance Comparisons and Down Selection of Small Motors for Two-Blade Heliogyro Solar Sail 6U CubeSat

    NASA Technical Reports Server (NTRS)

    Wiwattananon, Peerawan; Bryant, Robert G.

    2015-01-01

    This report compiles a review of 130 commercial small scale motors (piezoelectric and electric motors) and almost 20 researched-type small scale piezoelectricmotors for potential use in a 2 blades Heliogyro Solar Sail 6U CubeSat. In this application, a motor and gearhead (drive system) will deploy a roll of solar sailthin film (2 um thick)accommodated in a 2U CubeSat (100 x 200 x 100 mm) housing. The application requirements are: space rated, output torque at fulldeployment of 0.8 Nm, reel speed of 3 rpm, drive system weight limited to 150 grams, diameter limited to 50 mm, and the length not to exceed 40 mm. The 50mm diameter limit was imposed as motors with larger diameters would likely weigh too much and use more space on the satellite wall. This would limit theamount of the payload. The motors performance are compared between small scale, volume within 3x102 cm3 (3x105 mm3), commercial electric DC motors,commercial piezoelectric motors, and researched-type (non-commercial) piezoelectric motors extracted from scientific and product literature. The comparisonssuggest that piezoelectric motors without a gearhead exhibit larger output torque with respect to their volume and weight and require less input power toproduce high torque. A commercially available electric motor plus a gearhead was chosen through a proposed selection process to meet the applications designrequirements.

  1. (abstract) Observation by Clementine of a Hugh Opposition Surge on the Moon at Very Small Solar Phase Angles

    NASA Technical Reports Server (NTRS)

    Buratti, B. J.; Wang, M. C.

    1994-01-01

    The Clementine mission enabled the first quantative observations of the Moon at very small solar phase angles. It is well established from Earth-based observations that the Moon exhibits a non-linear increase in brightness as its face becomes fully illuminated to a terrestrial observer. Because the models of the opposition effect are sensitive indicators of surfical compaction state and particle size, observations at small solar phase angles are important to obtain. A recent model for optical coherent backscatter seeks to explain a narrow opposition spike at very small phase angles (< 1 degree) seen on several icy satellites , including Europa, Icarus 90, and Oberon . Over 90 images of the Moon's surface at phase angles less than 0.5(deg) (the minimum phase angle observable from Earth due to the Moon's angular size) were obtained by the Clementine spacecraft. Our analysis of these images shows the moon exhibits a surge in brightness of approximately 20% below 0.25(deg), comparable to the values observed on icy satellites. No color dependence was detected in the lunar phase curve below 2 degrees.

  2. Small differences in temperature interact with solar radiation to alter anthocyanin in grapes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Despite a century of research, we still lack a concrete, mechanistic understanding of solar radiation and temperature effects on anthocyanin accumulation and composition, crucial for red wine grapes. Our aim was to elucidate the mechanistic response to microclimate of anthocyanin metabolism in Viti...

  3. High-yield sorting of small-diameter carbon nanotubes for solar cells and transistors.

    PubMed

    Wang, Huiliang; Koleilat, Ghada I; Liu, Peng; Jiménez-Osés, Gonzalo; Lai, Ying-Chih; Vosgueritchian, Michael; Fang, Ya; Park, Steve; Houk, Kendall N; Bao, Zhenan

    2014-03-25

    We describe herein a high-yield method to selectively disperse semiconducting CoMoCAT (CO disproportionation on Co-Mo catalysts) single-walled carbon nanotubes (SWNTs) with regioregular poly(3-alkylthiophenes) polymers. We observed that the dispersion yield was directly related to the length of the polymer's alkyl side chains. Molecular dynamics simulations in explicit toluene (real toluene molecules) indicate that polythiophenes with longer alkyl side chains bind strongly to SWNTs, due to the increased overall surface contact area with the nanotube. Furthermore, the sorting process selectively enriches smaller-diameter CoMoCAT SWNTs with larger bandgaps, which is ideal for solar cell applications. Compared to the larger diameter sorted HiPco (High-Pressure CO) SWNTs, solar cells fabricated using our sorted CoMoCAT SWNTs demonstrated higher open-circuit voltage (Voc) and infrared external quantum efficiency (EQE). The Voc achieved is the highest reported for solar cells based on SWNT absorbers under simulated AM1.5 solar illumination. Additionally, we employed the sorted CoMoCAT SWNTs to fabricate thin film transistors with excellent uniformity and device performance. PMID:24484388

  4. Reconstructing our Interstellar Past: A Look at the Small Scale Structure in the Direction of the Historical Solar Trajectory

    NASA Astrophysics Data System (ADS)

    Redfield, S.; Scalo, J.; Smith, D. S.

    2007-07-01

    The properties of our nearby interstellar medium (NISM) out to ˜500 pc, including density, temperature, and velocity, provide a sample of the range and timing of environments that have been encountered by our solar system. These conditions influence the structure of the heliosphere, which modulates the flux of Galactic cosmic rays and interstellar gas and dust that reach the Earth. There is a long tradition of speculation focused on the effects of the ISM on heliospheric modulation of cosmic rays and interstellar hydrogen on atmospheric chemistry, cloud cover, glaciation episodes, and exogenous mutation, but the intensity and timing of such variations has never been established empirically, even in a statistical sense. The present work is aimed at evaluating the impact of small scale low column density structures in the NISM, using analysis of absorption line features toward early type stars, on the intensity and timing of heliospheric variations, and at placing these structures, invisible by most other techniques of tracing interstellar structure, in the overall dynamics of the interstellar medium. We present high spectral resolution observations of 49 stars within 10 degrees of the direction of the historical solar trajectory. This densely packed collection of sightlines provides an opportunity to (1) study small-scale structure in the shell separating the Local Bubble from the more distant NISM, (2) enable a rough reconstruction of the interstellar density profile, and hence cosmic ray flux history, encountered by the Solar System in the past 40 million years, and (3) clarify the prevalence of small column density fluctuations in the NISM.

  5. DETECTION OF SMALL-SCALE GRANULAR STRUCTURES IN THE QUIET SUN WITH THE NEW SOLAR TELESCOPE

    SciTech Connect

    Abramenko, V. I.; Yurchyshyn, V. B.; Goode, P. R.; Kitiashvili, I. N.; Kosovichev, A. G.

    2012-09-10

    Results of a statistical analysis of solar granulation are presented. A data set of 36 images of a quiet-Sun area on the solar disk center was used. The data were obtained with the 1.6 m clear aperture New Solar Telescope at Big Bear Solar Observatory and with a broadband filter centered at the TiO (705.7 nm) spectral line. The very high spatial resolution of the data (diffraction limit of 77 km and pixel scale of 0.''0375) augmented by the very high image contrast (15.5% {+-} 0.6%) allowed us to detect for the first time a distinct subpopulation of mini-granular structures. These structures are dominant on spatial scales below 600 km. Their size is distributed as a power law with an index of -1.8 (which is close to the Kolmogorov's -5/3 law) and no predominant scale. The regular granules display a Gaussian (normal) size distribution with a mean diameter of 1050 km. Mini-granular structures contribute significantly to the total granular area. They are predominantly confined to the wide dark lanes between regular granules and often form chains and clusters, but different from magnetic bright points. A multi-fractality test reveals that the structures smaller than 600 km represent a multi-fractal, whereas on larger scales the granulation pattern shows no multi-fractality and can be considered as a Gaussian random field. The origin, properties, and role of the population of mini-granular structures in the solar magnetoconvection are yet to be explored.

  6. Development of an Organic Rankine-Cycle power module for a small community solar thermal power experiment

    NASA Technical Reports Server (NTRS)

    Kiceniuk, T.

    1985-01-01

    An organic Rankine-cycle (ORC) power module was developed for use in a multimodule solar power plant to be built and operated in a small community. Many successful components and subsystems, including the reciever, power conversion subsystem, energy transport subsystem, and control subsystem, were tested. Tests were performed on a complete power module using a test bed concentrator in place of the proposed concentrator. All major single-module program functional objectives were met and the multimodule operation presented no apparent problems. The hermetically sealed, self-contained, ORC power conversion unit subsequently successfully completed a 300-hour endurance run with no evidence of wear or operating problems.

  7. New M- and V-shaped perylene diimide small molecules for high-performance nonfullerene polymer solar cells.

    PubMed

    Park, Gi Eun; Kim, Hyung Jong; Choi, Suna; Lee, Dae Hee; Uddin, Mohammad Afsar; Woo, Han Young; Cho, Min Ju; Choi, Dong Hoon

    2016-07-01

    New M- and V-shaped perylene diimide (PDI)-based small molecules using a non-conjugated 1,1-diphenylcyclohexane linker (CP-M and CP-V, respectively) were designed and synthesized as new n-type acceptors for nonfullerene-based polymer solar cells. The blended film with poly[(2,5-bis(2-hexyldecyloxy)phenylene)-alt-(5,6-difluoro-4,7-di(thiophen-2-yl)benzo[c][1,2,5]thiadiazole)] (PPDT2FBT) and CP-V displayed a higher power conversion efficiency of 5.28% due to higher short circuit current and fill factor values. PMID:27351371

  8. Atmospheric Solar Absorption measurements in the lowest 3-km of the atmosphere with small UAVs

    NASA Astrophysics Data System (ADS)

    Ramana, M. V.; Ramanathan, V.; Roberts, G.; Corrigan, C.; Nguyen, H. V.; McFarquhar, G.

    2007-12-01

    This paper reports unique measurements of atmospheric solar absorption and heating rates in the visible (0.4- 0.7 Ým) and broadband (0.3-2.8 Ým) spectral regions using vertically stacked multiple light weight autonomous unmanned aerial vehicles (UAVs) during the Maldives autonomous UAV campaign (MAC). The UAVs and ground based remote sensing instruments determined most of the parameters required for calculating the albedo and vertical distribution of solar fluxes. Measured fluxes have been compared with those derived from a Monte-Carlo radiative transfer algorithm which can incorporate both gaseous and aerosol components. The analysis focuses on a cloud-free day when the air was polluted due to long range transport from India, and the mean aerosol optical depth (AOD) was 0.31 and mean single scattering albedo was 0.92. The UAV measured absorption AOD was 0.019 which agreed within 20% of the value of 0.024 reported by a ground based instrument. The observed and simulated solar absorption agreed within 5% above 1.0 km and aerosol absorption accounted for 30% to 50% of the absorption depending upon the altitude and solar zenith angle. Thus there was no need to invoke anomalous or excess absorption or unknown physics in clear skies, provided we account for aerosol black carbon. The diurnal mean absorption values for altitudes between 0.5 and 3.0 km msl were observed to be 41¡Ó3 Wm-2 (1.5 K/day) in the broadband region and 8¡Ó2 Wm-2 (0.3 K/day) in the visible region. Future investigations into the atmospheric absorption in cloudy skies will characterize the spatial and temporal variation of the cloudy atmosphere in sufficient detail to simulate the vertical distribution of net solar fluxes to permit comparison with the collected radiative observations. This next phase will utilize 4 stacked UAVs to observe the extended cloud decks off the coast of California. A combination of observations and models will then be used to assess if the amount of solar absorption

  9. Techno-economic projections for advanced small solar thermal electric power plants to years 1990-2000

    NASA Technical Reports Server (NTRS)

    Fujita, T.; Manvi, R.; Roschke, E. J.; El-Gabalawi, N.; Herrera, G.; Kuo, T. J.; Chen, K. H.

    1979-01-01

    Advanced technologies applicable to solar thermal electric power systems in the 1990-200 time-frame are delineated for power applications that fulfill a wide spectrum of small power needs with primary emphasis on power ratings less than 10MWe. Projections of power system characteristics (energy and capital costs as a function of capacity factor) are made based on development of identified promising technologies and are used as the basis for comparing technology development options and combinations of these options to determine developmental directions offering potential for significant improvements. Stirling engines, Brayton/Rankine combined cycles and storage/transport concepts encompassing liquid metals, and reversible-reaction chemical systems are considered for two-axis tracking systems such as the central receiver or power tower concept and distributed parabolic dish receivers which can provide efficient low-cost solar energy collection while achieving high temperatures for efficient energy conversion. Pursuit of advanced technology across a broad front can result in post-1985 solar thermal systems having the potential of approaching the goal of competitiveness with conventional power systems.

  10. Coronal hole boundaries evolution at small scales. II. XRT view. Can small-scale outflows at CHBs be a source of the slow solar wind

    NASA Astrophysics Data System (ADS)

    Subramanian, S.; Madjarska, M. S.; Doyle, J. G.

    2010-06-01

    Aims: We aim to further explore the small-scale evolution of coronal hole boundaries using X-ray high-resolution and high-cadence images. We intend to determine the fine structure and dynamics of the events causing changes of coronal hole boundaries and to explore the possibility that these events are the source of the slow solar wind. Methods: We developed an automated procedure for the identification of transient brightenings in images from the X-ray telescope on-board Hinode taken with an Al Poly filter in the equatorial coronal holes, polar coronal holes, and the quiet Sun with and without transient coronal holes. Results: We found that in comparison to the quiet Sun, the boundaries of coronal holes are abundant with brightening events including areas inside the coronal holes where closed magnetic field structures are present. The visual analysis of these brightenings revealed that around 70% of them in equatorial, polar and transient coronal holes and their boundaries show expanding loop structures and/or collimated outflows. In the quiet Sun only 30% of the brightenings show flows with most of them appearing to be contained in the solar corona by closed magnetic field lines. This strongly suggests that magnetic reconnection of co-spatial open and closed magnetic field lines creates the necessary conditions for plasma outflows to large distances. The ejected plasma always originates from pre-existing or newly emerging (at X-ray temperatures) bright points. Conclusions: The present study confirms our findings that the evolution of loop structures known as coronal bright points is associated with the small-scale changes of coronal hole boundaries. The loop structures show an expansion and eruption with the trapped plasma consequently escaping along the “quasi” open magnetic field lines. These ejections appear to be triggered by magnetic reconnection, e.g. the so-called interchange reconnection between the closed magnetic field lines (BPs) and the open

  11. Constraining the orbits of small solar system bodies using spectroscopic Doppler shift measurements - a preliminary study

    NASA Astrophysics Data System (ADS)

    Zucker, S.; Tzur, I.

    2015-09-01

    In this short paper we examine whether the measurement of Doppler shifts in the solar light reflected off an asteroid surface may improve the accuracy of the determined orbit. Our results suggest it will be worthwhile to use high-resolution spectrographs, of the exoplanet-hunting type, to measure those Doppler shifts. Spectroscopic Doppler shifts might improve the accuracy of Earth-impact predictions, help to recover ``lost'' near-Earth objects, and may also significantly enhance the knowledge about dynamics of the Kuiper belt. Future high-resolution spectrographs on the VLT and the E-ELT may thus have an important role in studies of Solar-System dynamics and kinematics.

  12. Charging system using solar panels and a highly resonant wireless power transfer model for small UAS applications

    NASA Astrophysics Data System (ADS)

    Hallman, Sydney N.; Huck, Robert C.; Sluss, James J.

    2016-05-01

    The use of a wireless charging system for small, unmanned aircraft system applications is useful for both military and commercial consumers. An efficient way to keep the aircraft's batteries charged without interrupting flight would be highly marketable. While the general concepts behind highly resonant wireless power transfer are discussed in a few publications, the details behind the system designs are not available even in academic journals, especially in relation to avionics. Combining a highly resonant charging system with a solar panel charging system can produce enough power to extend the flight time of a small, unmanned aircraft system without interruption. This paper provides an overview of a few of the wireless-charging technologies currently available and outlines a preliminary design for an aircraft-mounted battery charging system.

  13. Active region upflow plasma: its relation to small activity and the solar wind

    NASA Astrophysics Data System (ADS)

    Mandrini, Cristina H.; Culhane, J. Leonard; Cristiani, Germán; Vásquez, Alberto; Van Driel-Gesztelyi, Lidia; Baker, Deborah; Pick, Monique; Demoulin, Pascal; Nuevo, Federico

    Recent studies show that active region (AR) upflowing plasma, observed by the Hinode EUV Imaging Spectrometer (EIS), can gain access to open field lines and be released into the solar wind via magnetic interchange reconnection occurring below the source surface at magnetic null-points in pseudo-streamer configurations. When only one simple bipolar AR is present on the Sun and it is fully covered by the separatrix of a streamer, like AR 10978 on December 2007, it seems unlikely that the upflowing AR plasma could find its way into the slow solar wind. However, signatures of plasma with AR composition at 1 AU that appears to originate from the West of AR 10978 were recently found by Culhane and coworkers. We present a detailed topology analysis of AR 10978 based on a linear force-free magnetic field model at the AR scale, combined with a global PFSS model. This allows us, on one hand, to explain the variations observed in the upflows to the West of the AR as the result of magnetic reconnection at quasi-separatrix layers (QSLs). While at a global scale, we show that reconnection, occurring in at least two main steps, first at QSLs and later at a high-altitude coronal null-point, allows the AR plasma to get around the topological obstacle of the streamer separatrix and be released into the solar wind.

  14. Detection of small-scale folds at a solar wind reconnection exhaust

    NASA Astrophysics Data System (ADS)

    Mistry, R.; Eastwood, J. P.; Hietala, H.

    2015-01-01

    of reconnection in the solar wind over the last few years appear to indicate that the majority of large-scale reconnecting current sheets are roughly planar, and that reconnection itself is quasi-steady. Most studies of solar wind exhausts have used spacecraft with large separations and relatively low time cadence ion measurements. Here we present multipoint Cluster observations of a reconnection exhaust and the associated current sheet at ACE and Wind, enabling it to be studied on multiple length scales and at high time resolution. While analysis shows that on large scales the current sheet is planar, detailed measurements using the four closely spaced Cluster spacecraft show that the trailing edge of the reconnection jet is nonplanar with folds orthogonal to the reconnection plane, with length scales of approximately 230 ion inertial lengths. Our findings thus suggest that while solar wind current sheets undergoing reconnection may be planar on large scales, they may also exhibit complex smaller-scale structure. Such structure is difficult to observe and has rarely been detected because exhausts are rapidly convected past the spacecraft in a single cut; there is therefore a limited set of spacecraft trajectories through the exhaust which would allow the nonplanar features to be intercepted. We consider how such nonplanar reconnection current sheets can form and the processes which may have generated the 3-D structure that was observed.

  15. Summary of the 19th International Atomic Energy Agency Technical Meeting on 'Research Using Small Fusion Devices'

    NASA Astrophysics Data System (ADS)

    Van Oost, G.; Mank, G.

    2011-08-01

    This paper presents a summary of recent results reported on several topics on magnetic confinement, dense magnetized plasmas, innovative fusion technology and applications, diagnostic systems and control and data acquisition systems. The main topics covered on the magnetic confinement devices, diagnostics and data acquisition concern the tokamak KTM (Kazakhstan Tokamak for Material testing) for materials research and testing, and IAEA Joint Experiments on small tokamaks. For the dense magnetized plasmas results on development and commissioning of plasma focus devices were reported. The plasmatron VISION I for innovative plasma-wall interaction studies, a lithium divertor for KTM and compact fusion reactors as neutron sources were presented.

  16. Best Practices for Siting Solar Photovoltaics on Municipal Solid Waste Landfills. A Study Prepared in Partnership with the Environmental Protection Agency for the RE-Powering America's Land Initiative: Siting Renewable Energy on Potentially Contaminated Land and Mine Sites

    SciTech Connect

    Kiatreungwattana, K.; Mosey, G.; Jones-Johnson, S.; Dufficy, C.; Bourg, J.; Conroy, A.; Keenan, M.; Michaud, W.; Brown, K.

    2013-04-01

    The Environmental Protection Agency and the National Renewable Energy Laboratory developed this best practices document to address common technical challenges for siting solar photovoltaics (PV) on municipal solid waste (MSW) landfills. The purpose of this document is to promote the use of MSW landfills for solar energy systems. Closed landfills and portions of active landfills with closed cells represent thousands of acres of property that may be suitable for siting solar photovoltaics (PV). These closed landfills may be suitable for near-term construction, making these sites strong candidate to take advantage of the 30% Federal Business Energy Investment Tax Credit. It was prepared in response to the increasing interest in siting renewable energy on landfills from solar developers; landfill owners; and federal, state, and local governments. It contains examples of solar PV projects on landfills and technical considerations and best practices that were gathered from examining the implementation of several of these projects.

  17. [Stellar Occultation Studies of Small Bodies in the Outer Solar System: Accomplishments, Status, and Plans

    NASA Technical Reports Server (NTRS)

    Elliott, James

    2005-01-01

    Bodies residing in the outer solar system exhibit unique physical processes, and some of the lessons learned from them can be applied to understanding what occurred in the outer solar system during its formation and early evolution. Pluto, the largest known Kuiper Belt object (KBO), and its near twin Triton--an ex-KBO that has been captured by Neptune--have nitrogen atmospheres that are in vapor-pressure equilibrium with surface ice. These atmospheres are most sensitively probed from Earth by the technique of Stellar occultations, which can provide the temperature and pressure profiles of these atmospheres at a spatial resolution of a few kilometers. Recent results from occultations show that the surface pressure of Triton's atmosphere has been increasing and that the shape of the atmosphere deviates from its expected spherical figure. With the occultation technique we can also learn the sizes of smaller bodies that have formed in the outer solar system: Charon, the Centaurs, and KBOs. Our proposed program involves identifying occultation candidates, predicting occultations, observing occultations, analysis of the data, and synthesis of the occultation results with other data. The main goals for our proposed work are to (i) further observe occultations by Triton with the objectives of understanding its pressure changes, distortion, and enigmatic thermal structure (ii) determine whether the abrupt drop in Pluto's stellar occultation light curve is caused by a sharp thermal gradient near its surface or by atmospheric haze, (iii) further observations to characterize the potential collapse of Pluto's atmosphere as it recedes from the sun (information that should be of interest to the Pluto-Kuiper Express), ( iv ) determine Charon's radius more accurately than can be done with the mutual events to derive a better estimate of Charon's density, and ( v ) directly determine the size (and albedo) of Centaurs with the goal of more accurately estimating the sizes of KBOS.

  18. Spectrum of Small-scale Plasma Fluctuations In The Solar Photosphere

    NASA Astrophysics Data System (ADS)

    Kyzyurov, Yu.

    Due to progress in high-resolution observations of process in the solar atmosphere we can obtain a better understanding of different phenomena on the Sun. In particular, data of the observations provide us with important information about turbulent veloc- ity field in the photoosphere. Detailed study of the velocity field and plasma density inhomogenieties is essential for investigation of the contribution of solar photosphere to the stochastic component of the magnetic field of the Sun. In this report the for- mation of plasma irregularities (with scales smaller than 1 Mm) by turbulent mixing of weakly ionized gas in the solar atmosphere is discussed. The consideration of the process takes a background plasma density gradient and a uniform magnetic field into account. It is supposed that plasma density is a passive scalar field and is submerged in turbulent motions of incompressible non-ionized gas. The relation between plasma density fluctuations and the random velocity field of neutral gas is derived from the 3-fluid equations. Restricting the consideration to the inertial range of scales of tur- bulence, an analytic expression for the spectrum of plasma fluctuations is obtained. This expression predicts power-law dependence for the spectrum of plasma irregular- ities in the photosphere in general as well as some possible departures in details of the spectrum from a simple power law with a constant power index. The rms level of rela- tive plasma-density fluctuations is estimated. Under the usual conditions for the quiet photosphere the level of the relative plasma fluctuations is less than or about 10% for wave numbers corresponding to the inertial range of turbulence.

  19. The Development of Small Solar Concentrating Systems with Heat Storage for Rural Food Preparation

    NASA Astrophysics Data System (ADS)

    van den Heetkamp, R. R. J.

    A system, consisting of a parabolic reflector mounted on a polar axis tracker, has been designed and built. Air at atmospheric pressure is heated by the concentrated solar radiation to temperatures of up to 400°C as it is sucked through the receiver and into the pebble-bed heat storage unit, by means of a fan at the bottom of the storage. The stored heat is recovered by the reversal of the fan and the resulting hot air can be used in a convection oven and other appliances. This report discusses practical aspects, as well as preliminary test results, of such a system.

  20. A 10 kW small solar power station and operations optimization

    NASA Astrophysics Data System (ADS)

    Gloel, J.

    1980-12-01

    Characteristics of the plant are: unpressurized hot water (95 C) for transport and storage of thermal energy; screw expansion engine operating with freon R114 for thermo-mechanical energy conversion; and an ac three phase generator interconnected with a static converter to provide line voltages and frequencies. A solar collector simulator was used in testing. Selection, assembly, and function of the system and each subsystem are detailed. Component performance results are listed. Component by component operation optimization results show the importance of correctly regulating the thermal cycle temperature as well as the freon expansion pump circuit pressure.

  1. Xatcobeo: Small Mechanisms for CubeSat Satellites - Antenna and Solar Array Deployment

    NASA Technical Reports Server (NTRS)

    EncinasPlaza, Jose Miguel; VilanVilan, Jose Antonio; AquadoAgelet, Fernando; BrandiaranMancheno, Javier; LopezEstevez, Miguel; MartinezFernandez, Cesar; SarmientoAres, Fany

    2010-01-01

    The Xatcobeo project, which includes the mechanisms dealt with here, is principally a university project to design and construct a CubeSat 1U-type satellite. This work describes the design and operational features of the system for antenna storage and deployment, and the design and simulations of the solar array deployment system. It explains the various problems faced and solutions adopted, with a view to providing valid data for any other applications that could find them useful, be they of a similar nature or not.

  2. Small scale solar wind turbulence due to nonlinear Alfvén waves

    NASA Astrophysics Data System (ADS)

    Kumar, S.; Sharma, R. P.; Moon, Y. J.

    2015-12-01

    In the work presented here, we study the evolution of wave localization and magnetic power spectrum using kinetic Alfven wave (AW) and fast AW in the solar wind plasma. We derived the dynamical equations for these wave modes using two-fluid model and then solved numerically to analyze power spectra as well as wave localization at different instants of time. The ponderomotive force associated with the pump is responsible for the wave localization and these localized structures become more chaotic as the system evolves with time until the modulational instability (or oscillating two-stream instability) mentioned here, saturates. We observe steepening of the spectra as we go from inertial range to the dispersion range i.e. nearly k-1.67 to k-3.0. The steepening of spectra may be described as the transfer of energy from longer scale to the smaller scale. The formation of complex magnetic filaments and change in the spectral index may be responsible for the charged particles acceleration in the solar wind plasma.

  3. Small-scale Solar Wind Turbulence Due to Nonlinear Alfven Waves

    NASA Astrophysics Data System (ADS)

    Kumar, Sanjay; Sharma, R. P.; Moon, Y.-J.

    2015-10-01

    We present an evolution of wave localization and magnetic power spectra in solar wind plasma using kinetic Alfvén waves (AWs) and fast AWs. We use a two-fluid model to derive the dynamical equations of these wave modes and then numerically solve these nonlinear dynamical equations to analyze the power spectra and wave localization at different times. The ponderomotive force associated with the kinetic AW (or pump) is responsible for the wave localization, and these thin slabs (or sheets) become more chaotic as the system evolves with time until the modulational instability (or oscillating two-stream instability) saturates. From our numerical results, we notice a steepening of the spectra from the inertial range (k‑1.67) to the dispersion range (k‑3.0). The steepening of the spectra could be described as the energy transference from longer to smaller scales. The formation of complex magnetic thin slabs and the change of the spectral index may be considered to be the main reason for the charged particles acceleration in solar wind plasma.

  4. The small community solar thermal power experiment. Parabolic dish technology for industrial process heat application

    NASA Technical Reports Server (NTRS)

    Polzien, R. E.; Rodriguez, D.

    1981-01-01

    Aspects of incorporating a thermal energy transport system (ETS) into a field of parabolic dish collectors for industrial process heat (IPH) applications were investigated. Specific objectives are to: (1) verify the mathematical optimization of pipe diameters and insulation thicknesses calculated by a computer code; (2) verify the cost model for pipe network costs using conventional pipe network construction; (3) develop a design and the associated production costs for incorporating risers and downcomers on a low cost concentrator (LCC); (4) investigate the cost reduction of using unconventional pipe construction technology. The pipe network design and costs for a particular IPH application, specifically solar thermally enhanced oil recovery (STEOR) are analyzed. The application involves the hybrid operation of a solar powered steam generator in conjunction with a steam generator using fossil fuels to generate STEOR steam for wells. It is concluded that the STEOR application provides a baseline pipe network geometry used for optimization studies of pipe diameter and insulation thickness, and for development of comparative cost data, and operating parameters for the design of riser/downcomer modifications to the low cost concentrator.

  5. Small-Molecule Thiophene-C{sub 60} Dyads As Compatibilizers in Inverted Polymer Solar Cells

    SciTech Connect

    Kim, Jong Bok; Allen, Kathryn; Oh, Soong Ju; Lee, Stephanie; Toney, Michael F.; Kim, Youn Sang; Kagan, Cherie R.; Nuckolls, Colin; Loo, Yueh-Lin

    2010-01-01

    This study details the synthesis and characterization of thiophene-C{sub 60} derivatives, nT-C{sub 60}, as compatibilizers for inverted bulk-heterojunction organic solar cells comprising poly(3-hexylthiophene), P3HT, and [6,6]-phenyl-C61-butyric acid methyl ester, PCBM. We find that the extent with which these compatibilizers can reduce interfacial energy and prevent domain coarsening and macrophase separation in active layers depends strongly on their molecular architecture. 4T-C{sub 60} is the most effective among the derivatives tested; its incorporation at 5 wt % to P3HT and PCBM effectively suppresses macrophase separation, even upon extended thermal annealing of the active layers. In sharp contrast to 4T-C{sub 60}, 8T-C{sub 60} is miscible with P3HT. The addition of 8T-C{sub 60} to active layers of inverted solar cells therefore does not arrest macrophase separation on extended annealing. 2T-C{sub 60} is also ineffective as a compatibilizing agent, presumably because its thiophene segment is too short so its presence at the interface between P3HT and PCBM does not increase interfacial adhesion.

  6. Effect of wind and solar radiation on metabolic heat production in a small desert rodent, Spermophilus tereticaudus.

    PubMed

    Wooden, K M; Walsberg, G E

    2000-03-01

    To understand better how complex interactions between environmental variables affect the energy balance of small diurnal animals, we studied the effects of the absence and presence of 950 W m(-)(2) simulated solar radiation combined with wind speeds ranging from 0. 25 to 1.00 m s(-)(1) on the metabolic rate and body temperature of the round-tailed ground squirrel Spermophilus tereticaudus. As wind speed increased from 0.25 to 1.00 m s(-)(1), metabolic heat production increased by 0.94 W in the absence of solar radiation and by 0.98 W in the presence of 950 W m(-)(2) simulated solar radiation. Exposure to simulated solar radiation reduced metabolic heat production by 0.68 W at a wind speed of 0.25 m s(-)(1), by 0.64 W at 0.50 m s(-)(1) and by 0.64 W at 1.00 m s(-)(1). Body temperature was significantly affected by environmental conditions, ranging from 32. 5 degrees C at a wind speed of 1.0 m s(-)(1) and no irradiance to 35. 6 degrees C at a wind speed of 0.50 m s(-)(1) with 950 W m(-)(2 )short-wave irradiance. In addition, several unusual findings resulted from this study. The coat of S. tereticaudus is very sparse, and the observed heat transfer of 5.68+/-0.37 W m(-)(2 ) degrees C(-)(1) (mean +/- s.e.m., N=11) is much higher than expected from either allometric equations or comparative studies with other rodents of similar mass. Solar heat gain was remarkably low, equalling only 10 % of intercepted radiation and suggesting a remarkably high regional thermal resistance at the tissue level. Animals remained normally active and alert at body temperatures as low as 32.5 degrees C. These findings suggest a unique combination of adaptations that allow S. tereticaudus to exploit a harsh desert environment. PMID:10667970

  7. Controlled current matching in small molecule organic tandem solar cells using doped spacer layers

    NASA Astrophysics Data System (ADS)

    Schueppel, Rico; Timmreck, Ronny; Allinger, Nikola; Mueller, Toni; Furno, Mauro; Uhrich, Christian; Leo, Karl; Riede, Moritz

    2010-02-01

    Current matching of the subcells is crucial to optimize the performance of tandem solar cells. Due to the thin film optics of organic solar cells, the position of the two subcells relative to the reflecting electrode becomes a very important issue. This is demonstrated for an indium tin oxide (ITO)/pin/pii/Al structure with thin intrinsic absorbing layers consisting of zinc-phthalocyanine and fullerene C60 and a metal-free lossless recombination contact between the subcells. By keeping the thickness of the absorbing layers constant and changing only the thickness of the inner p-doped transparent layer in 16 steps from 0to186nm, the distance of the ITO-sided subcell from the reflecting electrode (Al) is systematically varied. Thus, the p-doped layer works as an optical spacer between both subcells. The influence of its thickness on the thin film optics is shown in optical simulations and confirmed with current-voltage measurements. If both subcells are separated only by the recombination contact, they are positioned in the first interference maximum of the incident light and the currents of the individual subcells nearly matches. By increasing the spacer layer thickness, the ITO-sided subcell is moved to the first interference minimum, limiting the measured short circuit current density jsc of the tandem solar cell to about 1/2 of its initial value without spacer. At a spacer thickness of about 140nm, jsc recovers in the second interference maximum to nearly its original value. Within this series, an almost constant high fill factor of about 59% as well as a constant open circuit voltage of 1.06V is observed, showing that the Ohmic losses in the spacer are negligible. The power conversion efficiency of these devices reaches nearly 4% in the first and approximately 3.6% in the second interference maximum, respectively, in an outdoor test at 1sun. Furthermore, it is shown that for thicker absorber layers, an optimized current density cannot be reached in the first

  8. Radiation heat transfer simulation in a window for a small particle solar receiver using the Monte Carlo method

    NASA Astrophysics Data System (ADS)

    Whitmore, Alexander Jason

    Concentrating solar power systems are currently the predominant solar power technology for generating electricity at the utility scale. The central receiver system, which is a concentrating solar power system, uses a field of mirrors to concentrate solar radiation onto a receiver where a working fluid is heated to drive a turbine. Current central receiver systems operate on a Rankine cycle, which has a large demand for cooling water. This demand for water presents a challenge for the current central receiver systems as the ideal locations for solar power plants have arid climates. An alternative to the current receiver technology is the small particle receiver. The small particle receiver has the potential to produce working fluid temperatures suitable for use in a Brayton cycle which can be more efficient when pressurized to 0.5 MPa. Using a fused quartz window allows solar energy into the receiver while maintaining a pressurized small particle receiver. In this thesis, a detailed numerical investigation for a spectral, three dimensional, cylindrical glass window for a small particle receiver was performed. The window is 1.7 meters in diameter and 0.0254 meters thick. There are three Monte Carlo Ray Trace codes used within this research. The first MCRT code, MIRVAL, was developed by Sandia National Laboratory and modified by a fellow San Diego State University colleague Murat Mecit. This code produces the solar rays on the exterior surface of the window. The second MCRT code was developed by Steve Ruther and Pablo Del Campo. This code models the small particle receiver, which creates the infrared spectral direction flux on the interior surface of the window used in this work. The third MCRT, developed for this work, is used to model radiation heat transfer within the window itself and is coupled to an energy equation solver to produce a temperature distribution. The MCRT program provides a source term to the energy equation. This in turn, produces a new

  9. SMALL-SCALE PRESSURE-BALANCED STRUCTURES DRIVEN BY MIRROR-MODE WAVES IN THE SOLAR WIND

    SciTech Connect

    Yao, Shuo; He, J.-S.; Tu, C.-Y.; Wang, L.-H.; Marsch, E.

    2013-10-20

    Recently, small-scale pressure-balanced structures (PBSs) have been studied with regard to their dependence on the direction of the local mean magnetic field B{sub 0} . The present work continues these studies by investigating the compressive wave mode forming small PBSs, here for B{sub 0} quasi-perpendicular to the x-axis of Geocentric Solar Ecliptic coordinates (GSE-x). All the data used were measured by WIND in the quiet solar wind. From the distribution of PBSs on the plane determined by the temporal scale and angle θ{sub xB} between the GSE-x and B{sub 0} , we notice that at θ{sub xB} = 115° the PBSs appear at temporal scales ranging from 700 s to 60 s. In the corresponding temporal segment, the correlations between the plasma thermal pressure P{sub th} and the magnetic pressure P{sub B}, as well as that between the proton density N{sub p} and the magnetic field strength B, are investigated. In addition, we use the proton velocity distribution functions to calculate the proton temperatures T and T{sub ∥}. Minimum Variance Analysis is applied to find the magnetic field minimum variance vector B{sub N} . We also study the time variation of the cross-helicity σ{sub c} and the compressibility C{sub p} and compare these with values from numerical predictions for the mirror mode. In this way, we finally identify a short segment that has T > T{sub ∥}, proton β ≅ 1, both pairs of P{sub th}-P{sub B} and N{sub p}-B showing anti-correlation, and σ{sub c} ≈ 0 with C{sub p} > 0. Although the examination of σ{sub c} and C{sub p} is not conclusive, it provides helpful additional information for the wave mode identification. Additionally, B{sub N} is found to be highly oblique to B{sub 0} . Thus, this work suggests that a candidate mechanism for forming small-scale PBSs in the quiet solar wind is due to mirror-mode waves.

  10. The rate of planet formation and the solar system's small bodies

    NASA Technical Reports Server (NTRS)

    Safronov, Viktor S.

    1991-01-01

    The evolution of random velocities and the mass distribution of preplanetary body at the early stage of accumulation are currently under review. Arguments were presented for and against the view of an extremely rapid, runaway growth of the largest bodies at this stage with parameter values of Theta approximately greater than 10(exp 3). Difficulties are encountered assuming such a large Theta: (1) bodies of the Jovian zone penetrate the asteroid zone too late and do not have time to hinder the formation of a normal-sized planet in the asteroidal zone and thereby remove a significant portion of the mass of solid matter and (2) Uranus and Neptune cannot eject bodies from the solar system into the cometary cloud. Therefore, the values Theta less than 10(exp 2) appear to be preferable.

  11. The effect of concentrator field layout on the EE-1 small community solar power system

    NASA Technical Reports Server (NTRS)

    Pons, R. L.; Irwin, R. E.

    1981-01-01

    The point-focusing distributed receiver (PFDR) concept is employed by a number of solar thermal power systems currently under development. One type of PFDR system which shows particular promise incorporates distributed energy generation. According to this concept each parabolic dish collector is a self-contained power generation module, and a conventional electrical system is used to interconnect the modules. The concept is thus modular, and any number of power modules can be combined to achieve the required plant size. Given the benefits of mass production, it appears that this type of system can produce electricity at lower cost than is projected for conventional (fossil) power systems over the next decade. An employment of organic Rankine cycle heat engines is considered.

  12. Electronic excitations in solution-processed oligothiophene small-molecules for organic solar cells

    NASA Astrophysics Data System (ADS)

    Gala, F.; Mattiello, L.; Brunetti, F.; Zollo, G.

    2016-02-01

    First principles calculations based on density functional theory and many body perturbation theory have been employed to study the optical absorption properties of a newly synthesized oligo-thiophene molecule, with a quaterthiophene central unit, that has been designed for solution-processed bulk-heterojunction solar cells. To this aim we have employed the GW approach to obtain quasiparticle energies as a pre-requisite to solve the Bethe-Salpeter equation for the excitonic Hamiltonian. We show that the experimental absorption spectrum can be explained only by taking into account the inter-molecular transitions among the π-stacked poly-conjugated molecules that are typically obtained in solid-state organic samples.

  13. Mercury Sample Return and Small-Body Encounters Using Solar Sail Propulsion

    NASA Astrophysics Data System (ADS)

    Hughes, Gareth W.; McInnes, Colin R.

    Missions to planet Mercury have large V requirements, which impose almost unattainable demands on a Chemical propellant budget. Ion Propulsion is a viable alternative, but single or multiple gravity assists are necessary to conserve propellant. The propellant budget required to return a sample makes Chemical and Ion propulsion seem very unattractive. Solar sails exhibit an extremely high effective specific impulse over long mission durations at minimal mission expenditure. Propellant mass is not an issue, so large changes in V can be realised without necessitating the implementation of complex gravity assists, which prolong mission duration and restrict launch opportunities. Solar sails are ideal candidates for enabling orbital operations within the inner Solar System, and particularly for sample return missions, because of the inverse square proportionality of the heliocentric distance to the thrust magnitude. In this research work we have used a parameterised approach to sail control representation. The sail cone and clock angle histories were characterised by linear interpolation across a set of discrete nodes. The optimal control problem was thus transcribed to a Non-Linear Programming problem to select the optimal controls at the nodes that minimised the transfer time while enforcing the cartesian end-point boundary constraints (6 states for rendezvous). The Fortran77 optimisation package NPSOL 5.0 was used for this purpose with the variational equations of motion formulated in modified equinoctial orbital elements and integrated using a variable-order, adaptive step-size Adams-Moulton-Bashforth method. It has been ascertained that a sample could be returned from Mercury with a total interplanetary transit time of 4.5 years. The total sample return mission duration was 5.73 years if solar sail propulsion was utilised for the planetary capture and escape phases and to allow for lander descent, sample acquisition and ascent from the surface. This total mission

  14. Small space reactor power systems for unmanned solar system exploration missions

    SciTech Connect

    Bloomfield, H.S.

    1987-12-01

    A preliminary feasibility study of the application of small nuclear reactor space power systems to the Mariner Mark II Cassini spacecraft/mission was conducted. The purpose of the study was to identify and assess the technology and performance issues associated with the reactor power system/spacecraft/mission integration. The Cassini mission was selected because study of the Saturn system was identified as a high priority outer planet exploration objective. Reactor power systems applied to this mission were evaluated for two different uses. First, a very small 1 kWe reactor power system was used as an RTG replacement for the nominal spacecraft mission science payload power requirements while still retaining the spacecraft's usual bipropellant chemical propulsion system. The second use of reactor power involved the additional replacement of the chemical propulsion system with a small reactor power system and an electric propulsion system. The study also provides an examination of potential applications for the additional power available for scientific data collection. The reactor power system characteristics utilized in the study were based on a parametric mass model that was developed specifically for these low power applications. The model was generated following a neutronic safety and operational feasibility assessment of six small reactor concepts solicited from U.S. industry. This assessment provided the validation of reactor safety for all mission phases and generatad the reactor mass and dimensional data needed for the system mass model.

  15. Small space reactor power systems for unmanned solar system exploration missions

    NASA Technical Reports Server (NTRS)

    Bloomfield, Harvey S.

    1987-01-01

    A preliminary feasibility study of the application of small nuclear reactor space power systems to the Mariner Mark II Cassini spacecraft/mission was conducted. The purpose of the study was to identify and assess the technology and performance issues associated with the reactor power system/spacecraft/mission integration. The Cassini mission was selected because study of the Saturn system was identified as a high priority outer planet exploration objective. Reactor power systems applied to this mission were evaluated for two different uses. First, a very small 1 kWe reactor power system was used as an RTG replacement for the nominal spacecraft mission science payload power requirements while still retaining the spacecraft's usual bipropellant chemical propulsion system. The second use of reactor power involved the additional replacement of the chemical propulsion system with a small reactor power system and an electric propulsion system. The study also provides an examination of potential applications for the additional power available for scientific data collection. The reactor power system characteristics utilized in the study were based on a parametric mass model that was developed specifically for these low power applications. The model was generated following a neutronic safety and operational feasibility assessment of six small reactor concepts solicited from U.S. industry. This assessment provided the validation of reactor safety for all mission phases and generatad the reactor mass and dimensional data needed for the system mass model.

  16. Increased Efficiency in Small Molecule Organic Solar Cells Through the Use of a 56-π Electron Acceptor - Methano Indene Fullerene

    NASA Astrophysics Data System (ADS)

    Ryan, James W.; Matsuo, Yutaka

    2015-02-01

    Organic solar cells (OSCs) offer the possibility of harnessing the sun's ubiquitous energy in a low-cost, environmentally friendly and renewable manner. OSCs based on small molecule semiconductors (SMOSCs) - have made a substantial improvement in recent years and are now achieving power conversion efficiencies (PCEs) that match those achieved for polymer:fullerene OSCs. To date, all efficient SMOSCs have relied on the same fullerene acceptor, PCBM, in order to achieve high performance. The use of PCBM however, is unfavourable due to its low lying LUMO level, which limits the open-circuit voltage (VOC). Alternative fullerene derivatives with higher lying LUMOs are thus required to improve the VOC. The challenge, however, is to prevent the typical concomitant decrease in the short circuit current density (JSC) when using a higher LUMO fullerene. In this communication, we address the issue by applying methano indene fullerene, MIF, a bis-functionalised C60 fullerene that has a LUMO level 140 mV higher than PCBM, in solution processed SMOSCs with a well known small molecule donor, DPP(TBFu)2. MIF-based devices show an improved VOC of 140 mV over PC61BM and only a small decrease in the JSC, with the PCE increasing to 5.1% (vs. 4.5% for PC61BM).

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

    SciTech Connect

    Yu Daren; Xie Zongxia; Hu Qinghua; Yang Shuhong; Zhang Jun; Wang Jingxiu E-mail: zjun@ourstar.bao.ac.cn

    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{sub 0}.

  18. The nanoscale morphology of new types of solar cells based on solution-processed small-molecules

    NASA Astrophysics Data System (ADS)

    Herath, Nuradhika; Lauter, Valeria; Browning, Jim

    2014-03-01

    Organic electronics have become promising alternatives for the today's energy demand, owing to their low cost fabrication processes, ability to performance under low light, and flexibility. Solution processed small molecule (SM)- fullerene based solar cell devices have been subjected to number of studies recently with significant progress of power conversion efficiency (PCE). The bulk hetero junction (BHJ) consisting SM-fullerene blend is the most critical part of the solar cell device as nano-to-meso-scale morphology of BHJ plays a significant role in the device performances and properties. In this study we investigate the morphological structure of a device constructed from solution processed SM-molecule p - DTS(FBTTh2)2 with fullerene PC70BM BHJ blend using neutron reflectometry (NR). Here we present the scattering length density changes of PC70BM concentration along the film depth and the history dependence of the BHJ device by taking the measurements as-cast as thermally annealed (150 °C). This research was conducted at Spallation Neutron Source and at the Center for Nanophase Materials Sciences, which is sponsored at ORNL by the Scientific User Facilities Division, Office of Basic Energy Sciences, U.S. Department of Energy.

  19. Microscopic simulations of electronic excitations in donor-acceptor heterojunctions of small-molecule based solar cells

    NASA Astrophysics Data System (ADS)

    Baumeier, Bjoern

    2015-03-01

    Fundamental processes involving electronic excitations govern the functionality of molecular materials in which the dynamics of excitons and charges is determined by an interplay of molecular electronic structure and morphological order. To understand, e.g., charge separation and recombination at donor-acceptor heterojunctions in organic solar cells, knowledge about the microscopic details influencing these dynamics in the bulk and across the interface is required. For a set of prototypical heterojunctions of small-molecule donor materials with C60, we employ a hybrid QM/MM approach linking density-functional and many-body Green's functions theory and analyze the charged and neutral electronic excitations therein. We pay special attention the spatially-resolved electron/hole transport levels, as well as the relative energies of Frenkel and charge-transfer excitations at the interface. Finally, we link the molecular architecture of the donor material, its orientation on the fullerene substrate as well as mesoscale order to the solar cell performance.

  20. The history of re-connection and the concept of the solar wind plasma with relatively small electrical conductivity

    NASA Technical Reports Server (NTRS)

    Chertkov, A. D.

    1995-01-01

    Petschek's 're-connection' model, aspiring to be universal, treated as a boundary problem meets unresolvable difficulties connected with impossibility to specify correctly boundary and initial conditions. This problem was incorrectly formulated. Hence, ineradicable logarithmic singularities occurred on the boundary surfaces. Attempts to eliminate them by incorporating the finite electrical conductivity are incorrect. This should lead to the change in the equation type, boundary condition type and in consequence to the change in solutions. Besides, the slow mode shocks cannot be driven by small internal source. As an alternative a new plasma concept is suggested. The state of fully ionized plasma in space depends completely on the entropy of the plasma heating source and on the process in which plasma is involved. The presumptive source of the solar wind creation - the induction electric field of the solar origin - has very low entropy. The state of plasma should be very far from the thermodynamic equilibrium. Debye's screening is not complete. The excitation of the powerful resonant self-consistent electric fields in plasma provides low electric conductivity. The MHD problems should be treated in frameworks of dissipative theories.

  1. Resolving the Transition from Molecular to Atomic at 1/5 Solar Metallicity in the Small Magellanic Cloud

    NASA Astrophysics Data System (ADS)

    Jameson, Katherine; Bolatto, Alberto; Warren, Steven; Wolfire, Mark; Rubio, Monica; Herrera Camus, Rodrigo

    2015-08-01

    At a distance of 61 kpc, the Small Magellanic Cloud (SMC) affords an absolutely unique view of the low metallicity star-forming interstellar medium, providing the nearest laboratory to study processes relevant to star formation at high redshifts. We present new ALMA maps of 12CO and 13CO in 4 regions in the Southwest Bar of the SMC. These maps are the first high-resolution (1.6" ~ 0.6 pc) images of CO in a molecular cloud at 1/5 Solar metallicity. We show the structure of photodissociation regions for the first time at 1/5 Solar metallicity by combining the new ALMA data with Herschel maps of [CII], dust-based estimates of H2, NEWFIRM NIR 2 micron warm H2 images, and HI. We compare the data to recent 3D simulations by Glover & Mac Low (2011) and Shetty et al. (2011) to determine whether the equilibrium model of the HI to H2 transition breaks down. We present measures of the fraction of molecular gas traced by CO at low metallicity by combinging this study with the existing dust-based H2 estimates (Bolatto et al. 2011), which is needed to infer the molecular mass of any high-z ALMA CO observation.

  2. Parallelization of the SIR code for the investigation of small-scale features in the solar photosphere

    NASA Astrophysics Data System (ADS)

    Thonhofer, Stefan; Rubio, Luis R. Bellot; Utz, Dominik; Hanslmeier, Arnold; Jurçák, Jan

    2015-10-01

    Magnetic fields are one of the most important drivers of the highly dynamic processes that occur in the lower solar atmosphere. They span a broad range of sizes, from large- and intermediate-scale structures such as sunspots, pores and magnetic knots, down to the smallest magnetic elements observable with current telescopes. On small scales, magnetic flux tubes are often visible as Magnetic Bright Points (MBPs). Apart from simple V/I magnetograms, the most common method to deduce their magnetic properties is the inversion of spectropolarimetric data. Here we employ the SIR code for that purpose. SIR is a well-established tool that can derive not only the magnetic field vector and other atmospheric parameters (e.g., temperature, line-of-sight velocity), but also their stratifications with height, effectively producing 3-dimensional models of the lower solar atmosphere. In order to enhance the runtime performance and the usability of SIR we parallelized the existing code and standardized the input and output formats. This and other improvements make it feasible to invert extensive high-resolution data sets within a reasonable amount of computing time. An evaluation of the speedup of the parallel SIR code shows a substantial improvement in runtime.

  3. Solution processable diketopyrrolopyrrole (DPP) cored small molecules with BODIPY end groups as novel donors for organic solar cells

    PubMed Central

    Cortizo-Lacalle, Diego; Howells, Calvyn T; Pandey, Upendra K; Cameron, Joseph; Findlay, Neil J; Inigo, Anto Regis; Tuttle, Tell

    2014-01-01

    Summary Two novel triads based on a diketopyrrolopyrrole (DPP) central core and two 4,4-difluoro-4-bora-3a,4a-diaza-s-indacene (BODIPY) units attached by thiophene rings have been synthesised having high molar extinction coefficients. These triads were characterised and used as donor materials in small molecule, solution processable organic solar cells. Both triads were blended with PC71BM as an acceptor in different ratios by wt % and their photovoltaic properties were studied. For both the triads a modest photovoltaic performance was observed, having an efficiency of 0.65%. Moreover, in order to understand the ground and excited state properties and vertical absorption profile of DPP and BODIPY units within the triads, theoretical DFT and TDDFT calculations were performed. PMID:25550732

  4. Development of Extremely Wide-Field CMOS Camera Tomo-e:Contribution to Small Solar System Objects

    NASA Astrophysics Data System (ADS)

    Watanabe, Juniichi; Yoshikawa, Makoto; Urakawa, Seitaro; Usui, Fumihiko; Ohsawa, Ryou; Sako, Shigeyuki; Arimatsu, Ko

    2016-07-01

    We are developing an ultra wide-field fast camera, Tomo-e Gozen, which will be set up on the 105cm (F3.1) Schmidt telescope in Kiso Observatory at the University of Tokyo. Tomo-e equipped with 84 CMOS image sensors, which work in a room temperature, has a 20 square degree field of view and a fast readout speed of ~2 Hz. The purpose of this camera is the observation of the transient objects such as the counterpart of the gravitational wave events, the ultra wide-field capability with a high survey efficiency is also useful for small solar system bodies; NEOs, occultation events of the TNOs, and meteors. In the presentation, the specifications of Tomo-e are shown together with some preliminary results of the experimental observation run.

  5. Computational design of small phenothiazine dyes for dye-sensitized solar cells by functionalizations affecting the thiophene unit.

    PubMed

    Tu, Wei Han; Tan, Yi Yin; Rege, Omkar; Manzhos, Sergei

    2015-04-01

    We present a computational density functional theory study of the potential to improve the solar absorbance of small organic dyes featuring a phenothiazine donor and an acceptor moiety that combines a thiophene unit and a cyanoacrylic group. We consider different conjugation orders and functional groups on and around the thiophene unit, including electron-donating and electron-withdrawing moieties (H, F, CH3, CF3, and CN). We predict that by combining change of conjugation order and functionalization with electron withdrawing CN groups, it must be possible to decrease the excitation energy by up to 60 % vs. the parent dye (which would correspond to a redshift of the absorption peak maximum from 450 nm to 726 nm), effectively enabling red light absorption with small dyes. The contraction of the band gap is mostly due to the stabilization of the LUMO (by up to 1.8 eV), so that-in spite of the kinetic redundancy of the parent dye with respect to the conduction-band minimum of TiO2-care must be taken to ensure efficient injection when using the dyes in dye-sensitized solar cells. By studying 50 dyes, of which 44 are new dyes that are studied for the first time in this work, we identify parameters (such as charges, dihedral angles between donor and acceptor groups, bond length alternation) which can serve as predictors of the band gap. We find that bond length alternation or dihedral angles are not good predictors, while the charge on the thiophene unit is. PMID:25750021

  6. A solution-doped small molecule hole transport layer for efficient ITO-free organic solar cells (Presentation Recording)

    NASA Astrophysics Data System (ADS)

    Bormann, Ludwig; Selzer, Franz; Leo, Karl; Mueller-Meskamp, Lars

    2015-10-01

    Indium-tin-oxide-free (ITO-free) organic solar cells are an important, emerging research field because ITO transparent electrodes are a bottleneck for cheap large area devices on flexible substrates. Among highly conductive PEDOT:PSS and metal grids, percolation networks made of silver nanowires (AgNW) with a diameter in the nanoscale show a huge potential due to easy processing (e.g. spray coating), high aspect ratios and excellent electrical and optical properties like 15 Ohm/sq with a transmission of 83.5 % including the substrate. However, the inherent surface roughness of the AgNW film impedes the implementation as bottom electrode in organic devices, especially fully vacuum deposited ones, where often shunts are obtained. Here, we report about the solution processing of a small molecule hole transport layer (s-HTL) comprising N,N'-((Diphenyl-N,N'-bis)9,9,-dimethyl-fluoren-2-yl)-benzidine (BF-DPB, host material) and the proprietary NDP9 (p-dopant) deposited from tetrahydrofuran (THF) as non-halogenated, "green" solvent. We show, that the doping process already takes place in solution and that conductivities, achieved with this process at high doping efficiencies (4 * 10^-4 S/cm at 10 wt% doping concentration), are comparable to thermal co-evaporation of BF-DPB:NDP9 under high vacuum, which is the proven deposition method for doped small molecule films. Applying this s-HTL to AgNW films leads to well smoothened electrodes, ready for application in organic devices. Vacuum-deposited organic p-i-n solar cells with DCV2-5T-Me(3:3):C60 as active layer show a power conversion efficiency of 4.4% and 3.7% on AgNW electrode with 35nm and 90 nm wire diameter, compared to 4.1% on ITO with the s-HTL.

  7. Needs for Data and Tools to Plan and Interpret in situ Measurements of Small Solar System Bodies.

    NASA Astrophysics Data System (ADS)

    Huebner, W. F.

    Spacecraft missions to small solar system bodies (asteroids and comet nuclei) are increasing in numbers and in complexities. Here we summarize observational and experimental needs for basic data, development of tools for mission planning and data analysis, and list some resources that need further development. We categorize them in several broad domains: For solid bodies (asteroid and comet nuclei) we need properties such as material strengths and thermal and electrical properties (e.g., conductivities and heat capacities). While we know many properties of analog materials, they may not be applicable to the extreme conditions found in space. For example, densities of asteroids are usually lower than metallic, stony, or carbonaceous analog materials on Earth. This implies porosity at various scales that can fundamentally modify some properties. There are orders at magnitude differences in thermal conductivity of amorphous water ice. Small solar system bodies are not spherical; they have different moments of inertia about different axes. Nonalignment between principal axes of inertia and the spin axes causes tumbling motion and internal strains and stresses that can interfere with many measurements. For example, we have no models to estimate strain and stress induced noise that could interfere with seismology. We lack technology how to deliver and anchor instruments efficiently over a wide but unknown surface area on an asteroid or a comet nucleus in the absence of gravity. For comet comae we need more atomic and molecular data, particularly in the area of electron and energetic particle collisions. We provide lists of available databases and summarize data and tools that are urgently needed. We suggest the formation of an international working group to attack these issues and exchange information and data.

  8. A quick look method of detecting water of hydration in small solar system bodies

    NASA Technical Reports Server (NTRS)

    Vilas, F.

    1994-01-01

    The action of aqueous alteration of the near-subsurface material on asteroids and probably some satellites in the Solar System constitutes part of the formation history of the Solar System. The C-class asteroids (and subclasses B, G, and F) were initially believed to have undergone aqueous alteration based on their low albedos and neutral broadband visible and near-infrared colors. These spectra exhibit a sharp drop at wavelengths shorter than 0.55 microns due to a strong ferric oxide intervalence change transfer transition. This IVCT comprises multiple absorptions that are not uniquely indicative of phyllosilicates, but rather are present in the spectrum of any object containing Fe(2+) and Fe(3+) in its surface material. A definitive indication of aqueous alteration came when the broad IR absorption feature having a minimum near 3.0 microns indicative of structural hydroxyl (OH) and interlayer and and absorbed water in phyllosilicates was identified in the IR photometry of many C-class asteroids. Additional mineralogical compositional evidence of aqueously-altered asteroids has come as the result of high SNR narrowband spectrophotometry in the visible and near-infrared spectral regions taken using a CCD/spectrograph combination. An absorption feature centered at 0.7 microns indicative of an Fe(2+) - Fe(3+) charge transfer transition in oxidized iron in phyllosilicates in spectra of some low-albedo asteroids, especially C and G class, and CM2 carbonaceous chondrite meteorites was identified in the CCD spectra. The correlation and covariance of the 0.7-micron and 3.0-micron features were examined by comparing observations of asteroids common to both the CCD reflectance spectra and the 3.0-micron multicolor photometry data sets. Thirty-one pairs of observations were included in this training group. The results of the statistical study indicate that with a 95% confidence level, 84% of the objects observed either having or not having the 0.7-micron feature will

  9. A quick look method of detecting water of hydration in small solar system bodies

    NASA Astrophysics Data System (ADS)

    Vilas, F.

    1994-03-01

    The action of aqueous alteration of the near-subsurface material on asteroids and probably some satellites in the Solar System constitutes part of the formation history of the Solar System. The C-class asteroids (and subclasses B, G, and F) were initially believed to have undergone aqueous alteration based on their low albedos and neutral broadband visible and near-infrared colors. These spectra exhibit a sharp drop at wavelengths shorter than 0.55 microns due to a strong ferric oxide intervalence change transfer transition. This IVCT comprises multiple absorptions that are not uniquely indicative of phyllosilicates, but rather are present in the spectrum of any object containing Fe(2+) and Fe(3+) in its surface material. A definitive indication of aqueous alteration came when the broad IR absorption feature having a minimum near 3.0 microns indicative of structural hydroxyl (OH) and interlayer and and absorbed water in phyllosilicates was identified in the IR photometry of many C-class asteroids. Additional mineralogical compositional evidence of aqueously-altered asteroids has come as the result of high SNR narrowband spectrophotometry in the visible and near-infrared spectral regions taken using a CCD/spectrograph combination. An absorption feature centered at 0.7 microns indicative of an Fe(2+) - Fe(3+) charge transfer transition in oxidized iron in phyllosilicates in spectra of some low-albedo asteroids, especially C and G class, and CM2 carbonaceous chondrite meteorites was identified in the CCD spectra. The correlation and covariance of the 0.7-micron and 3.0-micron features were examined by comparing observations of asteroids common to both the CCD reflectance spectra and the 3.0-micron multicolor photometry data sets. Thirty-one pairs of observations were included in this training group. The results of the statistical study indicate that with a 95% confidence level, 84% of the objects observed either having or not having the 0.7-micron feature will

  10. Phase separation analysis of bulk heterojunctions in small-molecule organic solar cells using zinc-phthalocyanine and C60

    NASA Astrophysics Data System (ADS)

    Schünemann, Christoph; Wynands, David; Wilde, Lutz; Hein, Moritz Philipp; Pfützner, Steffen; Elschner, Chris; Eichhorn, Klaus-Jochen; Leo, Karl; Riede, Moritz

    2012-06-01

    To achieve efficient organic solar cells, donor and acceptor molecules are mixed in the photoactive layer to form a so-called bulk heterojunction. Due to molecular interactions, a certain degree of phase separation between donor and acceptor domains arises, which is necessary to achieve efficient charge extraction within the absorber layer. However, the mechanism that induces the phase separation is not fully understood and gaining detailed information about the molecular arrangement within these blend layers is quite challenging. We show that grazing incidence x-ray diffraction, combined with variable angle spectroscopic ellipsometry is a suitable way to investigate the molecular structure of blend layers in detail, consisting of a mixture of zinc-phthalocyanine (ZnPc) and C60. The degree of phase separation within the blend layer is influenced by substrate heating during the co-evaporation of ZnPc and C60 and by a variation of the mixing ratio. The effect of different blend layer morphologies on optical and electrical device performance is investigated by solar cell characterization and mobility measurements. We find that the molecular arrangement of C60 provides the essential driving force for efficient phase separation. Whereas spherical C60 molecules are able to form crystalline domains when deposited at elevated substrate temperatures, no ZnPc crystallites are observed, although the planar ZnPc molecules are not randomly oriented but standing upright within its domains. Comparing specular and grazing incidence x-ray diffraction, we find that only the latter method is able to detect nanocrystalline C60 in thin films due to its polycrystalline nature and small sized nanocrystallites. Solar cell measurements show an increase in fill factor and external quantum efficiency signal for blends with enhanced phase separation, induced by higher substrate temperatures. However, grazing incidence x-ray diffraction measurements reveal that ZnPc and C60 already form

  11. From asteroids to comets: Gas and dust production of the small-bodies in the solar system

    NASA Astrophysics Data System (ADS)

    Gilbert, Alyssa M.

    Comets are considered to be among the most pristine objects in our Solar System. Active comets have been studied for centuries, but the topic of transition objects (TOs) is relatively new in the area of planetary science. In either case, understanding the composition, activity and dynamics of these objects will help us understand the physical and dynamical evolution of comets, their connection to asteroids, and the environment and formation of the early Solar System. The overall theme of this thesis is to search for and study cometary activity on small-bodies in our Solar System. In particular, three separate, but related, projects are presented. Two studies utilized spectroscopic observations from the 1.2 m Elginfield telescope, the 1.8 m Dominion Astrophysical Observatory (DAO), and the 1.5 m Cerro-Tololo Inter-American Observatory (CTIO), to search for TOs and/or to observe active comets at different points in their orbit and of different dynamical ages. A third study used archived images from the Canada-France-Hawaii Telescope Legacy Survey (CFHTLS) to search for cometary activity on objects otherwise classified as asteroids. 1. The Elginfield and DAD telescopes were used to test the feasibility of a spectroscopic search program for TOs from these platforms. Even in this initial test mode, the data collected constitutes the largest spectroscopic search for TOs to date. However, previous results could not be improved upon, and this project was not deemed feasible with the current observations. 2. Five active comets were observed spectroscopically with the CTIO. Of particular interest were observations of new Oort cloud comet, 2006 VZ13, which passed perihelion during these observations. Gas and dust production rates and ratios were derived for three molecular species (CN, C2, and C3), and each comet was classified based on criteria from previous studies. 3. Using the CFHTLS, over 950 asteroidal objects were examined for evidence of comae or tail using a three

  12. Design and test of a novel solar imaging payload for small satellites

    NASA Astrophysics Data System (ADS)

    Asmolova, Olha; Andersen, Geoff; McHarg, Matthew G.; Quiller, Trey; Maldonado, Carlos; Dickinson, Thomas

    2015-09-01

    FalconSAT-7 (FS-7), a 3U CubeSat solar telescope, is the first-ever on-orbit demonstration of a lightweight deployable membrane primary optic that is twice the size of the host spacecraft. The telescope payload consists of the deployment structure, optical, electronic subsystems and occupying 1.5 U, while the rest of the volume is used for the bus, including satellite power, control, communications with the ground, etc. The deployment subsystem provides membrane deployment, positioning and tension with high precision for proper imaging, while the optical subsystem includes secondary optics with a camera to record images of the Sun at H-alpha. The electronics subsystem is used to control the primary optics deployment, focusing, image storage and transfer to the bus etc. We conducted an end-to-end flight optical subsystem test and a series of tests of the corrosion of the photon sieve due to atomic oxygen. The flight model build will be completed by October 2015with a launch date set for September 2016.

  13. A study of mass production and installation of small solar thermal electric power systems

    NASA Technical Reports Server (NTRS)

    Butterfield, J. F.

    1980-01-01

    Technological constraints, materials availability, production capacity, and manufacturing and installations plans and costs at different production levels are included in a study of concentrating collector industrialization. As cobalt for the engine and receiver is supply limited, alternative lower temperature alloys and higher temperature materials such as ceramics are discussed. Economics and production efficiency favor co-location of cellular and thin glass production for reflectors. Assembly and installation are expensive for small sites and few alternatives exist to apply mass production techniques to lower these costs for the selected design. Stepping motors in the size and quantities required are not commercially available today but could be in the future.

  14. The starting conditions for an optically small solar gamma ray flare

    NASA Technical Reports Server (NTRS)

    Simnett, G. M.; Ryan, J. M.

    1985-01-01

    It is suggested that optically small gamma-ray flares result from gradual pre-flare acceleration of protons over approximately 1,000 s by a series of magnetohydrodynamic shocks in the low corona. A fraction of the accelerated protons are trapped in the corona where they form a seed population for future acceleration. If the shock acceleration is sufficiently rapid proton energies may exceed the gamma-ray production threshold and trigger gamma-ray emission. This occurs without the total flare energy being necessarily large. Magnetic field geometry is an important parameter.

  15. The great dichotomy of the Solar System: Small terrestrial embryos and massive giant planet cores

    NASA Astrophysics Data System (ADS)

    Morbidelli, A.; Lambrechts, M.; Jacobson, S.; Bitsch, B.

    2015-09-01

    The basic structure of the Solar System is set by the presence of low-mass terrestrial planets in its inner part and giant planets in its outer part. This is the result of the formation of a system of multiple embryos with approximately the mass of Mars in the inner disk and of a few multi-Earth-mass cores in the outer disk, within the lifetime of the gaseous component of the protoplanetary disk. What was the origin of this dichotomy in the mass distribution of embryos/cores? We show in this paper that the classic processes of runaway and oligarchic growth from a disk of planetesimals cannot explain this dichotomy, even if the original surface density of solids increased at the snowline. Instead, the accretion of drifting pebbles by embryos and cores can explain the dichotomy, provided that some assumptions hold true. We propose that the mass-flow of pebbles is two-times lower and the characteristic size of the pebbles is approximately ten times smaller within the snowline than beyond the snowline (respectively at heliocentric distance r rice , where rice is the snowline heliocentric distance), due to ice sublimation and the splitting of icy pebbles into a collection of chondrule-size silicate grains. In this case, objects of original sub-lunar mass would grow at drastically different rates in the two regions of the disk. Within the snowline these bodies would reach approximately the mass of Mars while beyond the snowline they would grow to ∼ 20 Earth masses. The results may change quantitatively with changes to the assumed parameters, but the establishment of a clear dichotomy in the mass distribution of protoplanets appears robust provided that there is enough turbulence in the disk to prevent the sedimentation of the silicate grains into a very thin layer.

  16. Small-Scale Filament Eruptions Leading to Solar X-Ray Jets

    NASA Astrophysics Data System (ADS)

    Sterling, Alphonse; Moore, Ronald; Falconer, David

    2015-04-01

    We investigate the onset of ~10 random X-ray jets observed by Hinode/XRT. Each jet was near the limb in a polar coronal hole, and showed a ``bright point'' in an edge of the base of the jet, as is typical for previously-observed X-ray jets. We examined SDO/AIA EUV images of each of the jets over multiple AIA channels, including 304 Å, which detects chromospheric emissions, and 171, 193, and 211 Å, which detect cooler-coronal emissions. We find the jets to result from eruptions of miniature (size <~10 arcsec) filaments from the bases of the jets. Much of the erupting-filament material forms a chromospheric-temperature jet. In the cool-coronal channels, often the filament appears in absorption and the hotter EUV component of the jet appears in emission. The jet bright point forms at the location from which the miniature filament erupts, analogous to the formation of a standard solar flare arcade in the wake of the eruption of a typical larger-scalechromospheric filament. The spire of the jet forms on open field lines that presumably have undergone interchange reconnection with the erupting field that envelops and carries the miniature filament. Thus these X-ray jets and their bright points are made by miniature filament eruptions via ``internal'' and ``external'' reconnection of the erupting field. This is consistent with what we found for the onset of an on-disk coronal jet we examined in Adams et al. (2014). This work was supported by funding from NASA/LWS, Hinode, and ISSI.

  17. 1,8-Naphthalimide-Based Planar Small Molecular Acceptor for Organic Solar Cells.

    PubMed

    Zhang, Jicheng; Zhang, Xuejuan; Xiao, Hongmei; Li, Guangwu; Liu, Yahui; Li, Cuihong; Huang, Hui; Chen, Xuebo; Bo, Zhishan

    2016-03-01

    Four small molecular acceptors (SM1-4) comprising a central benzene core, two thiophene bridges and two 1,8-naphthalimide (NI) terminal groups were designed and synthesized by direct C-H activation. SM1 has a planar chemical structure and forms H-aggregation as films. By attachment of different substituents on the central benzene ring, the dihedral angles between the two NI end groups of SM1-4 gradually increased, leading to a gradual decrease of planarity. SM1-4 all possess a high-lying LUMO level, matching with wide band gap (WBG) polymer donors which usually have a high-lying LUMO level. When used in OSCs, devices based on SM1 and WBG donor PCDTBT-C12 gave higher electron mobility, superior film morphology and better photovoltaic performance. After optimization, a PCE of 2.78% with a V(oc) of 1.04 V was achieved for SM1 based devices, which is among the highest PCEs with a V(oc) higher than 1 V. Our results have demonstrated that NI based planar small molecules are potential acceptors for WBG polymer based OSCs. PMID:26845638

  18. Dust Interactions on Small Solar System Bodies and Technology Considerations for Exploration

    NASA Technical Reports Server (NTRS)

    Kobrick, Ryan,; Hoffman, Jeffrey; Pavone, Marco; Street, Kenneth; Rickman, Douglas

    2014-01-01

    Small-bodies such as asteroids and Mars' moons Phobos and Deimos have relatively unknown regolith environments. It is hypothesized that dust preserved in the regolith on the surfaces will have similar mechanical properties to lunar dust because of similar formation processes from micrometeorite bombardment, low relative gravity for slow settling times, and virtually no weathering because there is no atmosphere. This combination of processes infers that small-body dust particles will be highly angular and retain abrasive properties. The focus of this paper uses the mission architecture and engineering design for an asteroid hopper known as Hedgehog, a spherical spacecraft with several symmetric spikes used to aid with tumbling mobility in a low gravity environment. Dust abrasion considerations are highlighted throughout the paper relating to the lead authors' previous work, but act as an example of one of many important dust or regolith physical properties that need to be considered for future exploration. Measurable regolith properties are summarized in order to identify technologies that may be useful for exploration in terms of scientific return and spacecraft design. Previous instruments are summarized in this paper that could be used on the Hedgehog. Opportunities for hardware payloads are highlighted that include low mass solutions or dualpurpose instruments that can measure regolith or dust properties. Finally, dust mitigation suggestions are made for vehicles of this mobility profile.

  19. Rantiga Osservatorio, Tincana (MPC-D03): Observations and searching for small Solar System bodies using a remotely controlled telescope

    NASA Astrophysics Data System (ADS)

    Zolnowski, M.; Kusiak, M.

    2014-07-01

    Rantiga Osservatorio is the first Polish project aimed at discovering and observing small solar-system objects, including near-Earth objects and comets. The observatory officially started in March 2012, as a result of cooperation between two amateur astronomers: Michal Zolnowski and Michal Kusiak. Subsequently, our station received official designation D03 assigned by the IAU's Minor Planet Center. The equipment is installed in northern Italy, on the border between Emilia-Romagna and Tuscany, in the small village of Tincana at an altitude of 643 m. The heart of the observatory is a 0.4-meter reflector f/3.8, mounted on Paramount ME and CCD camera SBIG STX-16803. The equipment is controlled by an industrial computer connected to the internet, and software allowing for automation and remote control of the telescope from Poland. It is also the first Polish amateur observatory which has been used for the discoveries of potentially new asteroids since 1949. Between 2012 and 2013, Rantiga Osservatorio made it possible to submit over 13,000 astrometric measurements of 3,500 asteroids, and we also reported 1,151 candidates for potentially unknown objects. During our presentation, we would like to introduce details of design and several enhancements to allow a convenient and safe way to control an observing session from anywhere in the world using a smartphone.

  20. Stratospheric controlled perturbation experiment: a small-scale experiment to improve understanding of the risks of solar geoengineering

    PubMed Central

    Dykema, John A.; Keith, David W.; Anderson, James G.; Weisenstein, Debra

    2014-01-01

    Although solar radiation management (SRM) through stratospheric aerosol methods has the potential to mitigate impacts of climate change, our current knowledge of stratospheric processes suggests that these methods may entail significant risks. In addition to the risks associated with current knowledge, the possibility of ‘unknown unknowns’ exists that could significantly alter the risk assessment relative to our current understanding. While laboratory experimentation can improve the current state of knowledge and atmospheric models can assess large-scale climate response, they cannot capture possible unknown chemistry or represent the full range of interactive atmospheric chemical physics. Small-scale, in situ experimentation under well-regulated circumstances can begin to remove some of these uncertainties. This experiment—provisionally titled the stratospheric controlled perturbation experiment—is under development and will only proceed with transparent and predominantly governmental funding and independent risk assessment. We describe the scientific and technical foundation for performing, under external oversight, small-scale experiments to quantify the risks posed by SRM to activation of halogen species and subsequent erosion of stratospheric ozone. The paper's scope includes selection of the measurement platform, relevant aspects of stratospheric meteorology, operational considerations and instrument design and engineering. PMID:25404681

  1. Assessment of solar options for small power systems applications. Volume II. Identification and characterization of concepts for analysis

    SciTech Connect

    Laity, W.W.; Aase, D.T.; Apley, W.J.; Bird, S.P.; Drost, M.K.; Williams, T.A.

    1980-06-01

    The primary purpose of this study is to provide DOE with an independent, objective assessment of the principal solar thermal conversion concepts that have the potential for achieving commercial success as small electric power sytems in the 1- to 10-MWe range. Seven generic types of collectors, together with associated subsystems for electric power generation, were considered in this study. The collectors can be classified into three categories: (1) two-axis tracking (with compound curvature reflecting surfaces); (2) one-axis tracking (with single-curvature reflecting surfaces); and (3) nontracking (with low-concentration reflecting surfaces). These collectors can be combined with energy transport, energy storage, and power conversion subsystems in a wide variety of ways to formulate conceptual systems for electric power generation. In this study, attention was restricted to configurations that are potentially suitable for development as small power systems (1 to 10 MWe) in the long term (1990 to 2000), with initial commercialization by the mid-1980s. Cogeneration and total energy systems were beyond the scope of this study. All seven types of collectors were analyzed in conceptual system configurations with Rankine-cycle engines. Because they can operate at particularly high concentration ratios, two of the collectors (the Point Focus Central Receiver and the Point Focus Distributed Receiver) were also analyzed with Brayton-cycle engines. In addition, the latter of the two was analyzed with Stirling-cycle engines. With these engine options, 10 conceptual systems were formulated for analysis. Results are presented in detail. (WHK)

  2. Stratospheric controlled perturbation experiment: a small-scale experiment to improve understanding of the risks of solar geoengineering.

    PubMed

    Dykema, John A; Keith, David W; Anderson, James G; Weisenstein, Debra

    2014-12-28

    Although solar radiation management (SRM) through stratospheric aerosol methods has the potential to mitigate impacts of climate change, our current knowledge of stratospheric processes suggests that these methods may entail significant risks. In addition to the risks associated with current knowledge, the possibility of 'unknown unknowns' exists that could significantly alter the risk assessment relative to our current understanding. While laboratory experimentation can improve the current state of knowledge and atmospheric models can assess large-scale climate response, they cannot capture possible unknown chemistry or represent the full range of interactive atmospheric chemical physics. Small-scale, in situ experimentation under well-regulated circumstances can begin to remove some of these uncertainties. This experiment-provisionally titled the stratospheric controlled perturbation experiment-is under development and will only proceed with transparent and predominantly governmental funding and independent risk assessment. We describe the scientific and technical foundation for performing, under external oversight, small-scale experiments to quantify the risks posed by SRM to activation of halogen species and subsequent erosion of stratospheric ozone. The paper's scope includes selection of the measurement platform, relevant aspects of stratospheric meteorology, operational considerations and instrument design and engineering. PMID:25404681

  3. Small solar wind transients at 1 AU: STEREO observations (2007-2014) and comparison with near-Earth wind results (1995-2014)

    NASA Astrophysics Data System (ADS)

    Yu, W.; Farrugia, C. J.; Galvin, A. B.; Lugaz, N.; Luhmann, J. G.; Simunac, K. D. C.; Kilpua, E.

    2016-06-01

    This paper discusses small solar wind transients (STs) from 1995 to 2014. Using STEREO data, we have more sites from which to study STs near 1 AU. STEREO measurements are compared with wind observations near the Sun-Earth line. We examined statistically the dependence of ST occurrence frequency on (i) solar cycle phase, as monitored by the sunspot number (SSN), and (ii) solar wind speed. We find dependencies on both: an anticorrelation with SSN, an opposite trend to that of interplanetary coronal mass ejections (ICMEs), and correlation with slow solar wind (over 80% in the slow wind). We compare ST distributions during solar maximum year 2003, which had the lowest percentage of slow wind, and minimum year 2009, which had the highest percentage thereof, and show evidence of both dependencies. We give a statistical overview of ST parameters: field strength, B, Alfvén Mach number, MA, and proton beta, βp. They show the same temporal trends as the ambient solar wind but have twice (B) or one half (MA, βp) of its average values. In STs, the proton temperature is not below the temperature expected from corotating solar wind expansion. Non-force free models should be used in solar minimum years where βplasma≈ 1, while the force free models could be used in solar maximum when βplasma<<1. We find that only ˜5% of STs show enhanced values of iron charge states. Our work further supports the two-source origin of STs, i.e., the solar corona and the interplanetary medium.

  4. Characterisation of small-scale heating events in the solar atmosphere from 3D MHD simulations and their potential role in coronal heating

    NASA Astrophysics Data System (ADS)

    Haberreiter, M.; Guerreiro, N.; Hansteen, V. H.; Schmutz, W. K.

    2015-12-01

    The physical mechanism that heats the solar corona is one of the still open science questions in solar physics. One of the proposed mechanism for coronal heating are nanoflares. To investigate their role in coronal heating we study the properties of the small-scale heating events in the solar atmosphere using 3D MHD simulations. We present a method to identify and track these heating events in time which allows us to study their life time, energy, and spectral signatures. These spectal signatures will be compared with available spectrosopic observations obtained with IRIS and SUMER. Ultimately, these results will be important for the coordinated scientific exploitation of SPICE and EUI along with other instruments onboard Solar Orbiter to address the coronal heating problem.

  5. A small mission concept to the Sun-Earth Lagrangian L5 point for innovative solar, heliospheric and space weather science

    NASA Astrophysics Data System (ADS)

    Lavraud, B.; Liu, Y.; Segura, K.; He, J.; Qin, G.; Temmer, M.; Vial, J.-C.; Xiong, M.; Davies, J. A.; Rouillard, A. P.; Pinto, R.; Auchère, F.; Harrison, R. A.; Eyles, C.; Gan, W.; Lamy, P.; Xia, L.; Eastwood, J. P.; Kong, L.; Wang, J.; Wimmer-Schweingruber, R. F.; Zhang, S.; Zong, Q.; Soucek, J.; An, J.; Prech, L.; Zhang, A.; Rochus, P.; Bothmer, V.; Janvier, M.; Maksimovic, M.; Escoubet, C. P.; Kilpua, E. K. J.; Tappin, J.; Vainio, R.; Poedts, S.; Dunlop, M. W.; Savani, N.; Gopalswamy, N.; Bale, S. D.; Li, G.; Howard, T.; DeForest, C.; Webb, D.; Lugaz, N.; Fuselier, S. A.; Dalmasse, K.; Tallineau, J.; Vranken, D.; Fernández, J. G.

    2016-08-01

    We present a concept for a small mission to the Sun-Earth Lagrangian L5 point for innovative solar, heliospheric and space weather science. The proposed INvestigation of Solar-Terrestrial Activity aNd Transients (INSTANT) mission is designed to identify how solar coronal magnetic fields drive eruptions, mass transport and particle acceleration that impact the Earth and the heliosphere. INSTANT is the first mission designed to (1) obtain measurements of coronal magnetic fields from space and (2) determine coronal mass ejection (CME) kinematics with unparalleled accuracy. Thanks to innovative instrumentation at a vantage point that provides the most suitable perspective view of the Sun-Earth system, INSTANT would uniquely track the whole chain of fundamental processes driving space weather at Earth. We present the science requirements, payload and mission profile that fulfill ambitious science objectives within small mission programmatic boundary conditions.

  6. INSTANT: a Small Mission Concept to the Sun-Earth Lagrangian L5 Point for Innovative Solar, Heliospheric and Space Weather Sciences

    NASA Astrophysics Data System (ADS)

    Lavraud, B.; Liu, Y.

    2015-12-01

    We present a small mission concept to the Sun-Earth Lagrangian L5 point for innovative solar, heliospheric and space weather sciences. The proposed INvestigation of Solar-Terrestrial Activity aNd Transients (INSTANT) mission concept is designed to identify how solar coronal magnetic fields drive eruptions, mass transport and particle acceleration that impact the Earth and the heliosphere. The INSTANT concept would be the first to (1) obtain measurements of coronal magnetic fields from space, and (2) determine coronal mass ejection (CME) kinematics with unparalleled accuracy. Thanks to innovative instrumentation at a vantage point that provides the most suitable perspective view of the Sun-Earth system, INSTANT would, in addition, uniquely track the whole chain of fundamental processes driving space weather. We present the science requirements, payload and mission profile which fulfill ambitious science objectives within small mission programmatic boundary conditions.

  7. Phase 1 of the First Small Power System Experiment (engineering Experiment No. 1). Volume 4: Commercial System Definition. [development and testing of a solar thermal power plant

    NASA Technical Reports Server (NTRS)

    Holl, R. J.

    1979-01-01

    The development and design of a modular solar thermal power system for application in the 1 to 10 MWe range is described. The system is used in remote utility applications, small communities, rural areas, and for industrial uses. The operational reliability, the minimum risk of failure, and the maintenance and repair characteristics are determined and the commercial system design is defined.

  8. Indan-1,3-dione electron-acceptor small molecules for solution-processable solar cells: a structure-property correlation.

    PubMed

    Winzenberg, Kevin N; Kemppinen, Peter; Scholes, Fiona H; Collis, Gavin E; Shu, Ying; Singh, Th Birendra; Bilic, Ante; Forsyth, Craig M; Watkins, Scott E

    2013-07-18

    A structure-device performance correlation in bulk heterojunction solar cells for new indandione-derived small molecule electron acceptors, FEHIDT and F8IDT, is presented. Devices based on the former exhibit higher power conversion efficiency (2.4%) and higher open circuit voltage, a finding consistent with reduced intermolecular interactions. PMID:23739171

  9. Global scale-invariance of small-scale magnetic fluctuations in solar wind turbulence as seen by CLUSTER

    NASA Astrophysics Data System (ADS)

    Kiyani, K. H.; Chapman, S. C.; Khotyaintsev, Y. V.; Dunlop, M. W.; Sahraoui, F.

    2009-12-01

    Spacecraft measurements of magnetic fluctuations of collisionless plasma turbulence in the solar wind typically show an ‘inertial range’ of MHD turbulence with a power-law power spectra. At higher frequencies a spectral break is seen around the ion-gyroscale with a subsequent steeper power-law, indicating a cross-over to spatial-temporal scales where kinetic effects become important. Theories for this second scaling range, also known as the “dissipation/dispersion” range focus on the spectral slope and the associated scaling exponents. We will present some results from very high-frequency magnetic field data from the four Cluster II spacecraft in intervals where the spacecraft were in quasi-stationary ambient solar wind and where the instruments were operating in burst mode. The magnetic field data are from the fluxgate and search-coil magnetometers from the Cluster FGM experiment (~67Hz), and the STAFF experiment (~450 Hz). These data sets provide observations of this dissipation/dispersion range over approximately two decades in frequency. This high cadence allows a better determination of the statistics at these small scales; especially the estimation of scaling exponents. We present a robust multiscale statistical analysis focusing on power spectra, PDFs of field fluctuations and higher-order statistics to quantify the scaling of fluctuations; as well as describing the degree of anisotropy in the fluctuations parallel and perpendicular to the average magnetic field. Both neutral fluid and MHD turbulence share a ‘‘classic’’ statistical signature - namely an intermittent multifractal scaling seen in the higher-order statistics. We test the statistical properties of the dissipation range and find in contrast monoscaling behavior, i.e., a global scale invariance. This provides a strong discriminator for the physics and phenomenology of the dissipation range in collisionless plasmas. Reference article: K. H. Kiyani, S. C. Chapman, Yu. V. Khotyaintsev

  10. MULTIWAVELENGTH OBSERVATIONS OF SMALL-SCALE RECONNECTION EVENTS TRIGGERED BY MAGNETIC FLUX EMERGENCE IN THE SOLAR ATMOSPHERE

    SciTech Connect

    Guglielmino, S. L.; Zuccarello, F.; Bellot Rubio, L. R.; Aulanier, G.; Vargas DomInguez, S.; Kamio, S.

    2010-12-01

    The interaction between emerging magnetic flux and the pre-existing ambient field has become a 'hot' topic for both numerical simulations and high-resolution observations of the solar atmosphere. The appearance of brightenings and surges during episodes of flux emergence is believed to be a signature of magnetic reconnection processes. We present an analysis of a small-scale flux emergence event in NOAA 10971, observed simultaneously with the Swedish 1 m Solar Telescope on La Palma and the Hinode satellite during a joint campaign in 2007 September. Extremely high-resolution G-band, H{alpha}, and Ca II H filtergrams, Fe I and Na I magnetograms, EUV raster scans, and X-ray images show that the emerging region was associated with chromospheric, transition region and coronal brightenings, as well as with chromospheric surges. We suggest that these features were caused by magnetic reconnection at low altitude in the atmosphere. To support this idea, we perform potential and linear force-free field extrapolations using the FROMAGE service. The extrapolations show that the emergence site is cospatial with a three-dimensional null point, from which a spine originates. This magnetic configuration and the overall orientation of the field lines above the emerging flux region are compatible with the structures observed in the different atmospheric layers and remain stable against variations of the force-free field parameter. Our analysis supports the predictions of recent three-dimensional numerical simulations that energetic phenomena may result from the interaction between emerging flux and the pre-existing chromospheric and coronal field.

  11. Exploring Small Spatial Scales in the Transition Region and Solar Corona with the Very High Angular Resolution Imaging Spectrometer (VERIS)

    NASA Astrophysics Data System (ADS)

    Chua, D. H.; Korendyke, C. M.; Vourlidas, A.; Brown, C. M.; Tun-Beltran, S.; Klimchuk, J. A.; Landi, E.; Seely, J.; Davila, J. M.; Hagood, R.; Roberts, D.; Shepler, E.; Feldman, R.; Moser, J.; Shea, J.

    2012-12-01

    Theoretical and experimental investigations of the transition region and coronal loops point to the importance of processes occurring on small spatial scales in governing the strong dynamics and impulsive energy release in these regions. As a consequence, high spatial, temporal, and temperature resolution over a broad temperature range, and accuracy in velocity and density determinations are all critical observational parameters. Current instruments lack one or more of these properties. These observational deficiencies have created a wide array of opposing descriptions of coronal loop heating and questions such as whether or not the plasma within coronal loops is multi-thermal or isothermal. High spectral and spatial resolution spectroscopic data are absolutely required to resolve these controversies and to advance our understanding of the dynamics within the solar atmosphere. We will achieve this with the Very High Angular Resolution Imaging Spectrometer (VERIS) sounding rocket payload. VERIS consists of an off-axis paraboloid telescope feeding a very high angular resolution, extreme ultraviolet (EUV) imaging spectrometer that will provide the first ever, simultaneous sub-arcsecond (0.16 arcsecond/pixel) spectra in bright lines needed to study plasma structures in the transition region, quiet corona, and active region core. It will do so with a spectral resolution of >5000 to allow Doppler velocity determinations to better than 3 km/s. VERIS uses a novel two-element, normal incidence optical design with highly reflective, broad wavelength coverage EUV coatings to access a spectral range with broad temperature coverage (0.03-15 MK) and density-sensitive line ratios. Combined with Hinode Solar Optical Telescope (SOT) and ground based observatories, VERIS will deliver simultaneous observations of the entire solar atmosphere from the photosphere to the multi-million degree corona at sub-arcsecond resolution for the first time ever, allowing us to understand the

  12. Small solar electric system components demonstration. [thermal storage modules for Brayton systems

    NASA Technical Reports Server (NTRS)

    1980-01-01

    The design and testing of high temperature thermal storage modules (TSM) are reported. The test goals were to demonstrate the thermocline propagation in the TSM, to measure the steepness of the thermocline, and to measure the effectiveness of the TSM when used in a Brayton system. In addition, a high temperature valve suitable for switching the TSM at temperatures to 1700 F is described and tested. Test results confirm the existence of a sharp thermocline under design conditions. The thermal profile was steeper than expected and was insensitive to air density over the range of the test conditions. Experiments were performed which simulated the airflow of a small Brayton engine, 20 KWe, having a pair of thermal storage modules acting as efficient recuperators. Low pressure losses, averaging 12 inches of water, and high effectiveness, 93% for a 15 minute switching cycle, were measured. The insulation surrounding the ceramic core limited thermal losses to approximately 1 KWt. The hot valve was operated over 100 cycles and performed well at temperatures up to 1700 F.

  13. Formation of amino acid precursors in the Solar System small bodies using Aluminium-26 as an energy source

    NASA Astrophysics Data System (ADS)

    Kebukawa, Yoko; Kobayashi, Kensei; Kawai, Jun; Mita, Hajime; Tachibana, Shogo; Yoda, Isao; Misawa, Shusuke

    2016-07-01

    Carbonaceous chondrites contain various organic matter including amino acids that may have played an important role for origin of life on the early Earth. The parent bodies of the chondritic meteorites likely formed from silicate dust grains containing some water ice and organic compounds. These planetesimals are known to contain short-lived radio isotopes such as ^{26}Al, and the heat generated from the decay of ^{26}Al was considered to be used for melting ice. The liquid water, for example, changed anhydrous silicates into hydrous silicates, i.e., aqueous alteration. The liquid water would act also as an ideal reaction medium for various organic chemistry. Cody et al. [1] proposed IOM formation via formose reaction starting with formaldehyde and glycolaldehyde during aqueous activity in the small bodies. Additional hydrothermal experiments showed that ammonia enhanced the yields of IOM like organic solids [2]. Formaldehyde and ammonia are ubiquitous in the Solar System and beyond, e.g., comets contain H _{2}CO : NH _{3} : H _{2}O = 0.4-4 : 0.5-1.5 : 100 [3]. Thus these molecules can be expected to have existed in some Solar System small bodies. We study the liquid phase chemistry of the formaldehyde and ammonia, including formations of amino acid precursor molecules, via hydrothermal experiments at isothermal temperatures of 90 °C to 200 °C. We also evaluate the effects of gamma-ray which is released from the decay of ^{26}Al with gamma-ray irradiation experiments using a ^{60}Co gamma-ray source at Tokyo Institute of Technology. Amino acids were detected mostly after acid hydrolysis of heated or irradiated solutions, indicating that most of the amino acids in the products exist as precursors. Some samples contained 'free' amino acids that were detected without acid hydrolysis, but much lower abundance than after acid hydrolysis. Kendrick mass defect (KMD) analyses of High resolution mass spectra obtained using ESI-MS revealed that various CHO and CHNO

  14. Structure and dynamics of small scale magnetic fields in the solar atmosphere Results of high resolution polarimetry and image reconstruction

    NASA Astrophysics Data System (ADS)

    Janssen, K.

    2003-07-01

    Two-dimensional spectrograms were obtained at the Vacuum Tower Telescope, Tenerife, in order to study the structure of small scale magnetic fields on the Sun. The speckle reconstruction method that is used for data processing gives high resolution images and wavelength scans in left and right circular polarized light, from which magnetic field maps are calculated using the center of gravity method. The geometric similarity of magnetic structures is studied via the area- perimeter-relation, from which the Hausdorff-dimension of the rim of a structure is determined. The investigation shows that the actual value of the fractal dimension depends on the threshold that is used to determine the borders of the magnetic areas. Higher treshold values lead to smaller fractal dimensions. This can be explained by the concentration of strong magnetic fields while weak fields spread out in more complex structures. With a treshold of 80 Gauss a fractal dimension of D=1,40(5) is obtained. Furthermore, the dimension obtained by observed data is compared to the fractal dimension gained from MHD simulations. It is found that if the measurement scales are adjusted correctly the dimensions for both datasets match quite well. In a second part the dynamics of the mass motions were analysed and a coarse estimate of the energy conveyed by these movements to the magnetic field is given. The energy flux is strong enough to participate in the heating of the solar chromosphere and corona over active regions.

  15. Enhancement of Open-Circuit Voltage by Using the 58-π Silylmethyl Fullerenes in Small-Molecule Organic Solar Cells.

    PubMed

    Jeon, Il; Delacou, Clément; Nakagawa, Takafumi; Matsuo, Yutaka

    2016-04-20

    The application of 58-π-1,4-bis(silylmethyl)[60]fullerenes, C60 (CH2 SiMe2 Ph)(CH2 SiMe2 Ar) (Ar=Ph and 2-methoxylphenyl for SIMEF-1 and SIMEF-2, respectively), in small-molecule organic solar cells with a diketopyrrolopyrrole donor (3,6-bis[5-(benzofuran-2-yl)thiophen-2-yl]-2,5-bis(2-ethylhexyl)pyrrolo[3,4-c]pyrrole-1,4-dione (DPP(TBFu)2 )) is demonstrated. With the 58-π-silylmethyl fullerene acceptor, SIMEF-1, the devices showed the highest efficiency of 4.57 % with an average of 4.10 %. They manifested an improved open-circuit voltage (1.03 V) owing to the high-lying LUMO level of SIMEF-1, while maintaining a high short-circuit density (9.91 mA cm(-2) ) through controlling the crystallinity of DPP by thermal treatment. On the other hand, despite even higher open-circuit voltage (1.05 V), SIMEF-2-based devices showed lower performances of 3.53 %, owing to a low short-circuit current density (8.33 mA cm(-2) ) and fill factor (0.40) arising from the asymmetric structure, which results in a lower mobility and immiscibility. PMID:26840629

  16. Small molecule based N-phenyl carbazole substituted diketopyrrolopyrroles as donors for solution-processed bulk heterojunction organic solar cells.

    PubMed

    Patil, Yuvraj; Misra, Rajneesh; Chen, F C; Sharma, Ganesh D

    2016-08-17

    We report two acetylene-bridged small molecules DPP5 and DPP6 with low HOMO-LUMO gaps as donors along with PC71BM as an acceptor for the fabrication of solution-processed bulk heterojunction solar cells. After the optimization, i.e. weight ratio of donor to acceptor and surface treatment of the active layer, we achieved overall power conversion efficiencies up to 4.65% (Jsc = 8.19 mA cm(-2), Voc = 0.98 V and FF = 0.58) and 5.73% (Jsc = 9.58 mA cm(-2), Voc = 0.98 V and FF = 0.61), for DPP5:PC71BM and DPP6:PC71BM respectively, which are superior to those for the devices based on as-cast active layers. The significant change in the power conversion efficiency is attributed to the improvement in nanoscale morphology, balanced charge transport and charge collection efficiency, induced through the surface treatment. PMID:27489031

  17. Scale-invariance and Anisotropy of small-scale magnetic fluctuations in solar wind turbulence as seen by CLUSTER

    NASA Astrophysics Data System (ADS)

    Hnat, B.; Kiyani, K. H.; Chapman, S. C.; Khotyaintsev, Y. V.; Dunlop, M. W.; Sahraoui, F.

    2009-12-01

    In-situ observations of fluctuations in the solar wind typically show an ‘inertial range’ of MHD turbulence, and at higher frequencies, a cross-over to spatial temporal scales where kinetic effects become important. In-situ monitors such as WIND and ACE have provided observations over a decade of this dissipation/dispersion range that have motivated theoretical studies that in turn predict the nature of the scaling in this region. We will present some results from very high-frequency magnetic field data from the four Cluster II spacecraft in intervals where the spacecraft were in quasi-stationary ambient solar wind and where the instruments were operating in burst mode. The magnetic field data are from the fluxgate and search-coil magnetometers from the Cluster FGM experiment (~67Hz), and the STAFF experiment (~450 Hz). These data sets provide observations of this dissipation/dispersion range over approximately two decades in frequency. This high cadence allows a more precise determination of the statistics at these small scales; especially the estimation of scaling exponents. Theories centred around the dispersion of MHD waves and their associated damping and particle heating have been proposed to account for this scaling range. Since the spacecraft data shows a clean break from the scaling in the inertial range, followed by a different power-law spanning over approximately two decades, these theories centre around predictions of the spectral slope and the associated scaling exponents. Motivated by the need to distinguish these theoretical predictions, we perform a robust multiscale statistical analysis focusing on power spectra, PDFs of field fluctuations, higher-order statistics to quantify the scaling of fluctuations; as well as describing the degree of anisotropy in the fluctuations parallel and perpendicular to the average magnetic field. We use these results to infer the nature of the physical processes as we pass through the crossover from inertial

  18. Detection and characterization of small-scale heating events in the solar atmosphere from 3D-MHD simulations and their potential role in coronal heating

    NASA Astrophysics Data System (ADS)

    Guerreiro, Nuno; Haberreiter, Margit; Schmutz, Werner; Hansteen, Viggo

    2016-07-01

    Aiming at better understanding the mechanism(s) responsible for the coronal heating we focus on analyzing the properties of the magnetically generated small-scale heating events (SSHEs) in the solar atmosphere. We present a comprehensive method to detect and follow SSHEs over time in 3D-MHD simulations of the solar atmosphere. Applying the method we are able to better understand the properties of the SSHEs and how the plasma in their vicinity respond to them. We study the lifetime, energy and spectral signatures and show that the energy flux dissipated by them is enough to heat the corona. Ultimately, these results will be important for the coordinated scientific exploration of SPICE and EUI along with other instruments on board solar orbiter.

  19. Enhance the light-harvesting capability of the ITO-free inverted small molecule solar cell by ZnO nanorods.

    PubMed

    Lin, Ming-Yi; Wu, Shang-Hsuan; Hsiao, Li-Jen; Budiawan, Widhya; Boopathi, Karunakara Moorthy; Tu, Wei-Chen; Chang, Yia-Chung; Chu, Chih-Wei

    2016-08-01

    The ITO-free inverted SMPV1:PC71BM solar cells with an Al doped ZnO (AZO) transparent electrodes are fabricated. The AZO thin film prepared by pulsed laser deposition (PLD) technique exhibits high transmission (>85%) and low sheet resistance (~30 Ω/sq) and the power conversion efficiency (PCE) of devices based on AZO electrode can reach around 4%. To further enhance the light harvesting of the absorption layer of solar cells, ZnO nanorods interlayer is grown on the AZO layer before the deposition the active layer. The absorption spectrums of devices under various conditions are also simulated by RCWA method to identify the optical saturation length of the ZnO nanorods. The PCE of ITO-free inverted small molecule solar cell improved with ZnO nanorods can reach 6.6%. PMID:27505758

  20. Characterization of small-scale heating events in the solar atmosphere from 3D-MHD simulations and their potential role in coronal heating

    NASA Astrophysics Data System (ADS)

    Guerreiro, Nuno; Haberreiter, Margit; Hansteen, Viggo; Schmutz, Werner

    2016-04-01

    Aiming at better understanding the mechanism(s) responsible for the coronal heating and the ubiquitous redshifts observed in the lower transition region we focus on analyzing the properties of small-scale heating events (SSHEs) in the solar atmosphere. We present a comprehensive method to follow SSHEs over time in 3D-MHD simulations of the solar atmosphere. Applying the method we are able to better understand the properties of the SSHEs and how the plasma in their vicinity respond to them. We present results for the lifetime, energy and spectral signatures of the SSHEs. Ultimately, these results will be important for the coordinated scientific exploration of SPICE and EUI along with other interments on board solar orbiter. ​

  1. Stratospheric O3 changes during 2001-2010: The small role of solar flux variations in a CTM

    NASA Astrophysics Data System (ADS)

    Dhomse, Sandip; Chipperfield, Martyn; Feng, Wuhu; Ball, William; Unruh, Yvonne; Haigh, Joanna; Krivova, Natalie; Solanki, Sami

    2013-04-01

    Solar spectral fluxes (or irradiance) measured by the SOlar Radiation and Climate Experiment (SORCE) shows different variability at ultraviolet (UV) wavelengths compared to other irradiance measurements and models (e.g. NRL, SATIRE-S). Some modelling studies have suggested that stratospheric O3 changes during solar cycle 23 (1996-2008) can only be reproduced if SORCE solar fluxes are used. We have used a 3-D chemical transport model (CTM), forced by meteorology from the European Centre for Medium-Range Weather Forecasts (ECMWF), to simulate stratospheric O3 using 3 different solar flux datasets (SORCE, NRL-SSI and SATIRE-S). Simulated O3 changes are compared with Microwave Limb Sounder (MLS) and Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) satellite data. Modelled O3 anomalies using all solar flux datasets show good agreement with the observations, despite the different flux variations. A notable feature during this period is a robust positive solar signal in the tropical middle stratosphere. The CTM reproduces these changes through dynamical information contained in the analyses. Changes in the upper stratosphere cannot be used to discriminate between solar flux datasets due to large uncertainties in the O3 observations. Overall this study suggests that the UV variations detected by SORCE are not necessary to reproduce observed stratospheric O3 changes during 2001-2010.

  2. Stratospheric O3 changes during 2001-2010: the small role of solar flux variations in a CTM

    NASA Astrophysics Data System (ADS)

    Dhomse, S. S.; Chipperfield, M. P.; Feng, W.; Ball, W. T.; Unruh, Y. C.; Haigh, J. D.; Krivova, N. A.; Solanki, S. K.; Smith, A. K.

    2013-05-01

    Solar spectral fluxes (or irradiance) measured by the SOlar Radiation and Climate Experiment (SORCE) show different variability at ultraviolet (UV) wavelengths compared to other irradiance measurements and models (e.g. NRL-SSI, SATIRE-S). Some modelling studies have suggested that stratospheric/lower mesospheric O3 changes during solar cycle 23 (1996-2008) can only be reproduced if SORCE solar fluxes are used. We have used a 3-D chemical transport model (CTM), forced by meteorology from the European Centre for Medium-Range Weather Forecasts (ECMWF), to simulate middle atmospheric O3 using three different solar flux datasets (SORCE, NRL-SSI and SATIRE-S). Simulated O3 changes are compared with Microwave Limb Sounder (MLS) and Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) satellite data. Modelled O3 anomalies from all solar flux datasets show good agreement with the observations, despite the different flux variations. The off-line CTM reproduces these changes through dynamical information contained in the analyses. A notable feature during this period is a robust positive solar signal in the tropical middle stratosphere due to changes in stratospheric dynamics. Ozone changes in the lower mesosphere cannot be used to discriminate between solar flux datasets due to large uncertainties and the short time span of the observations. Overall this study suggests that, in a CTM, the UV variations detected by SORCE are not necessary to reproduce observed stratospheric O3 changes during 2001-2010.

  3. Stratospheric O3 changes during 2001-2010: the small role of solar flux variations in a chemical transport model

    NASA Astrophysics Data System (ADS)

    Dhomse, S. S.; Chipperfield, M. P.; Feng, W.; Ball, W. T.; Unruh, Y. C.; Haigh, J. D.; Krivova, N. A.; Solanki, S. K.; Smith, A. K.

    2013-10-01

    Solar spectral fluxes (or irradiance) measured by the SOlar Radiation and Climate Experiment (SORCE) show different variability at ultraviolet (UV) wavelengths compared to other irradiance measurements and models (e.g. NRL-SSI, SATIRE-S). Some modelling studies have suggested that stratospheric/lower mesospheric O3 changes during solar cycle 23 (1996-2008) can only be reproduced if SORCE solar fluxes are used. We have used a 3-D chemical transport model (CTM), forced by meteorology from the European Centre for Medium-Range Weather Forecasts (ECMWF), to simulate middle atmospheric O3 using three different solar flux data sets (SORCE, NRL-SSI and SATIRE-S). Simulated O3 changes are compared with Microwave Limb Sounder (MLS) and Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) satellite data. Modelled O3 anomalies from all solar flux data sets show good agreement with the observations, despite the different flux variations. The off-line CTM reproduces these changes through dynamical information contained in the analyses. A notable feature during this period is a robust positive solar signal in the tropical middle stratosphere, which is due to realistic dynamical changes in our simulations. Ozone changes in the lower mesosphere cannot be used to discriminate between solar flux data sets due to large uncertainties and the short time span of the observations. Overall this study suggests that, in a CTM, the UV variations detected by SORCE are not necessary to reproduce observed stratospheric O3 changes during 2001-2010.

  4. Advances in Small Pixel TES-Based X-Ray Microcalorimeter Arrays for Solar Physics and Astrophysics

    NASA Technical Reports Server (NTRS)

    Bandler, S. R.; Adams, J. S.; Bailey, C. N.; Busch, S. E.; Chervenak, J. A.; Eckart, M. E.; Ewin, A. E.; Finkbeiner, F. M.; Kelley, R. L.; Kelly, D. P.; Kilbourne, C. A.; Porst, J.-P.; Porter, F. S.; Sadleir, J. E.; Smith, S. J.; Wassell, E. J.

    2012-01-01

    We are developing small-pixel transition-edge-sensor (TES) for solar physics and astrophysics applications. These large format close-packed arrays are fabricated on solid silicon substrates and are designed to accommodate count-rates of up to a few hundred counts/pixel/second at a FWHM energy resolution approximately 2 eV at 6 keV. We have fabricated versions that utilize narrow-line planar and stripline wiring. We present measurements of the performance and uniformity of kilo-pixel arrays, incorporating TESs with single 65-micron absorbers on a 7s-micron pitch, as well as versions with more than one absorber attached to the TES, 4-absorber and 9-absorber "Hydras". We have also fabricated a version of this detector optimized for lower energies and lower count-rate applications. These devices have a lower superconducting transition temperature and are operated just above the 40mK heat sink temperature. This results in a lower heat capacity and low thermal conductance to the heat sink. With individual single pixels of this type we have achieved a FWHM energy resolution of 0.9 eV with 1.5 keV Al K x-rays, to our knowledge the first x-ray microcalorimeter with sub-eV energy resolution. The 4-absorber and 9-absorber versions of this type achieved FWHM energy resolutions of 1.4 eV and 2.1 eV at 1.5 keV respectively. We will discuss the application of these devices for new astrophysics mission concepts.

  5. 48 CFR 15.604 - Agency points of contact.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... agency: upcoming solicitations; Broad Agency Announcements; Small Business Innovation Research programs; Small Business Technology Transfer Research programs; Program Research and Development Announcements;...

  6. Microstructure of amorphous-silicon-based solar cell materials by small-angle x-ray scattering. Annual subcontract report, 6 April 1994--5 April 1995

    SciTech Connect

    Williamson, D.L.

    1995-08-01

    The general objective of this research is to provide detailed microstructural information on the amorphous-silicon-based, thin-film materials under development for improved multijunction solar cells. The experimental technique used is small-angle x-ray scattering (SAXS) providing microstructural data on microvoid fractions, sizes, shapes, and their preferred orientations. Other microstructural features such as alloy segregation, hydrogen-rich clusters and alloy short-range order are probed.

  7. Phase 1 of the First Small Power System Experiment (engineering Experiment No. 1). Volume 1: Executive Summary. [development and testing of a solar thermal power plant

    NASA Technical Reports Server (NTRS)

    Holl, R. J.

    1979-01-01

    The development of a modular solar thermal power system for application in the 1 to 10 MWe range is presented. The system is used in remote utility applications, small communities, rural areas, and for industrial uses. Investigations are performed on the energy storage requirements and type of energy storage, concentrator design and field optimization, energy transport, and power conversion subsystems. The system utilizes a Rankine cycle, an axial flow steam turbine for power conversion, and heat transfer sodium for collector fluid.

  8. Grid-Free 2D Plasma Simulations of the Complex Interaction Between the Solar Wind and Small, Near-Earth Asteroids

    NASA Technical Reports Server (NTRS)

    Zimmerman, M. I.; Farrell, W. M.; Poppe, A. R.

    2014-01-01

    We present results from a new grid-free 2D plasma simulation code applied to a small, unmagnetized body immersed in the streaming solar wind plasma. The body was purposely modeled as an irregular shape in order to examine photoemission and solar wind plasma flow in high detail on the dayside, night-side, terminator and surface-depressed 'pocket' regions. Our objective is to examine the overall morphology of the various plasma interaction regions that form around a small body like a small near-Earth asteroid (NEA). We find that the object obstructs the solar wind flow and creates a trailing wake region downstream, which involves the interplay between surface charging and ambipolar plasma expansion. Photoemission is modeled as a steady outflow of electrons from illuminated portions of the surface, and under direct illumination the surface forms a non-monotonic or ''double-sheath'' electric potential upstream of the body, which is important for understanding trajectories and equilibria of lofted dust grains in the presence of a complex asteroid geometry. The largest electric fields are found at the terminators, where ambipolar plasma expansion in the body-sized night-side wake merges seamlessly with the thin photoelectric sheath on the dayside. The pocket regions are found to be especially complex, with nearby sunlit regions of positive potential electrically connected to unlit negative potentials and forming adjacent natural electric dipoles. For objects near the surface, we find electrical dissipation times (through collection of local environmental solar wind currents) that vary over at least 5 orders of magnitude: from 39 Micro(s) inside the near-surface photoelectron cloud under direct sunlight to less than 1 s inside the particle-depleted night-side wake and shadowed pocket regions

  9. Transient Small-Scale Magnetic Flux Emergence and Atmospheric Response Observed with New Solar Telescope and SDO

    NASA Astrophysics Data System (ADS)

    Vargas Domínguez, Santiago; Kosovichev, Alexander G.

    2014-06-01

    State-of-the art solar instrumentation is now revealing the activity of the Sun at the highest temporal and spatial resolution. Granular-scale magnetic flux emergence and the response of the solar atmosphere is one of the key topics. Observations with the 1.6m aperture New Solar Telescope (NST) at Big Bear Solar Observatory (BBSO) are making next steps in our understanding of the solar surface structure. On August 7, 2013, NST observed active region NOAA 11810 in different photospheric and chromospheric wavelengths. The region displays a group of solar pores, in the vicinity of which we detected a site of emerging magnetic flux accompanied by intense and very confined abnormal granulation dynamics, observed in the photospheric TiO 7057 A with a resolution of 0.034 “/pix. Following the expansion of exploding granules in this site, we observed a sudden appearance of an extended surge in the HeI 10830A data (bandpass of 0.05 A). The SDO/HMI data used to study the evolution of the magnetic field and Doppler velocities reveal a short-lived emerging loop-like structure with strong upflows. We used the SDO/AIA data to investigate the response of the transition region and corona to the transient emerging flux phenomenon. We compare the results with previous observations, and propose a scenario for the production of plasma surges by the transient magnetic flux emergence events.

  10. Solar Sailing

    NASA Technical Reports Server (NTRS)

    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.

  11. Solar Energy Systems

    NASA Technical Reports Server (NTRS)

    1984-01-01

    Calibrated in kilowatt hours per square meter, the solar counter produced by Dodge Products, Inc. provides a numerical count of the solar energy that has accumulated on a surface. Solar energy sensing, measuring and recording devices in corporate solar cell technology developed by Lewis Research Center. Customers for their various devices include architects, engineers and others engaged in construction and operation of solar energy facilities; manufacturers of solar systems or solar related products, such as glare reducing windows; and solar energy planners in federal and state government agencies.

  12. The use of stellar occultations to study the figures and atmospheres of small bodies in the outer solar system

    NASA Astrophysics Data System (ADS)

    Person, Michael James

    The methods of analyzing stellar occultations by small bodies in the outer solar system are discussed with examples from Triton, Pluto, and Charon. Simulations were performed characterizing the analysis of multi-chord occultations including: the effects of the direction of residual minimization in figure fits, the complications in measuring the reliability of fitted figure parameters when there are few degrees of freedom, and the proper treatment of grazing chords in model fitting. The 2005 July 11 C313.2 stellar occultation by Charon was analyzed. Occultation timings from the three published data sets were combined to accurately determine the mean radius of Charon: 606.0 ± 1.5 km. The analysis indicates that a slight oblateness in the body (0.006 ± 0.003) best matches the data, with a confidence level of 86%. Charon's mean radius corresponds to a bulk density of 1.63 ± 0.07 g/cm 3 , which is significantly less than Pluto's (1.92 ± 0.12 g/cm 3 ), consistent with an impact formation scenario in which at least one of the impactors was differentiated. The 2002 August 21 P131.1 and the 1988 June 9 P8 stellar occultations by Pluto were analyzed. The ellipticity of Pluto's atmosphere as measured by the P131.1 event is 0.066 ± 0.040, with a Gaussian confidence level of 63%, and the ellipticity as measured by the P8 occultations is 0.091 ± 0.041, with a Gaussian confidence level of 70%. If this nonsphericity is confirmed, its size and variation could possibly be attributed to superrotating winds driven by sources such as surface frost migration due to changing insolation patterns or albedo properties, gravity waves, and an asymmetric mass distribution in Pluto itself. The 2001 August 23 Tr231 stellar occultation by Triton was analyzed. The half- light radius of Triton's atmosphere was calculated from astrometrically calibrated model fits to the occultation light curve. The resulting half-light radius of 1479.01 km is larger than the value of 1456.3 km derived from

  13. Impact of the Crystalline Packing Structures on Charge Transport and Recombination via Alkyl Chain Tunability of DPP-Based Small Molecules in Bulk Heterojunction Solar Cells.

    PubMed

    Song, Chang Eun; Kim, Yu Jin; Suranagi, Sanjaykumar R; Kini, Gururaj P; Park, Sangheon; Lee, Sang Kyu; Shin, Won Suk; Moon, Sang-Jin; Kang, In-Nam; Park, Chan Eon; Lee, Jong-Cheol

    2016-05-25

    A series of small compound materials based on benzodithiophene (BDT) and diketopyrrolopyrrole (DPP) with three different alkyl side chains were synthesized and used for organic photovoltaics. These small compounds had different alkyl branches (i.e., 2-ethylhexyl (EH), 2-butyloctyl (BO), and 2-hexyldecyl (HD)) attached to DPP units. Thin films made of these compounds were characterized and their solar cell parameters were measured in order to systematically analyze influences of the different side chains of compounds on the film microstructure, molecular packing, and hence, charge-transport and recombination properties. The relatively shorter side chains in the small molecules enabled more ordered packing structures with higher crystallinities, which resulted in higher carrier mobilities and less recombination factors; the small molecule with the EH branches exhibited the best semiconducting properties with a power conversion efficiency of up to 5.54% in solar cell devices. Our study suggested that tuning the alkyl chain length of semiconducting molecules is a powerful strategy for achieving high performance of organic photovoltaics. PMID:27156705

  14. A D-π-A1-π-A2 push-pull small molecule donor for solution processed bulk heterojunction organic solar cells.

    PubMed

    Gautam, Prabhat; Misra, Rajneesh; Biswas, Subhayan; Sharma, Ganesh D

    2016-05-18

    Herein, benzothiadiazole (BTD), as an acceptor A1, has been used as a backbone to link triphenylamine (TPA) as donor and naphthalimide (NPI) as acceptor (A2) moieties through ethylene linkers to design a small molecule. The donor-π-acceptor-π-acceptor (D-π-A1-π-A2) type small molecule denoted as was synthesized. In order to use it as an electron donor for solution processed bulk heterojunction small molecule solar cells its photonic and electronic properties were explored. The small molecule organic solar cells based on the optimized blend of with PC71BM processed in chloroform showed a power conversion efficiency (PCE) of 2.21%, which was significantly improved up to 6.67%, when a two-step annealing (TSA) treated blend was used as an active layer. The increase in the PCE was due to the enhancement in both Jsc and FF. The improvement in Jsc was related to the enhancement in the light harvesting efficiency of a TSA treated active layer relative to the as-cast layer, which is reflected in a better IPCE and better charge collection. The TSA treatment also leads to better nanoscale morphology for exciton dissociation into free charge carriers and improved crystallinity for balanced charge transport. PMID:27149659

  15. Side-chain Engineering of Benzo[1,2-b:4,5-b’]dithiophene Core-structured Small Molecules for High-Performance Organic Solar Cells

    NASA Astrophysics Data System (ADS)

    Yin, Xinxing; An, Qiaoshi; Yu, Jiangsheng; Guo, Fengning; Geng, Yongliang; Bian, Linyi; Xu, Zhongsheng; Zhou, Baojing; Xie, Linghai; Zhang, Fujun; Tang, Weihua

    2016-05-01

    Three novel small molecules have been developed by side-chain engineering on benzo[1,2-b:4,5-b’]dithiophene (BDT) core. The typical acceptor-donor-acceptor (A-D-A) structure is adopted with 4,8-functionalized BDT moieties as core, dioctylterthiophene as π bridge and 3-ethylrhodanine as electron-withdrawing end group. Side-chain engineering on BDT core exhibits small but measurable effect on the optoelectronic properties of small molecules. Theoretical simulation and X-ray diffraction study reveal the subtle tuning of interchain distance between conjugated backbones has large effect on the charge transport and thus the photovoltaic performance of these molecules. Bulk-heterojunction solar cells fabricated with a configuration of ITO/PEDOT:PSS/SM:PC71BM/PFN/Al exhibit a highest power conversion efficiency (PCE) of 6.99% after solvent vapor annealing.

  16. Side-chain Engineering of Benzo[1,2-b:4,5-b’]dithiophene Core-structured Small Molecules for High-Performance Organic Solar Cells

    PubMed Central

    Yin, Xinxing; An, Qiaoshi; Yu, Jiangsheng; Guo, Fengning; Geng, Yongliang; Bian, Linyi; Xu, Zhongsheng; Zhou, Baojing; Xie, Linghai; Zhang, Fujun; Tang, Weihua

    2016-01-01

    Three novel small molecules have been developed by side-chain engineering on benzo[1,2-b:4,5-b’]dithiophene (BDT) core. The typical acceptor-donor-acceptor (A-D-A) structure is adopted with 4,8-functionalized BDT moieties as core, dioctylterthiophene as π bridge and 3-ethylrhodanine as electron-withdrawing end group. Side-chain engineering on BDT core exhibits small but measurable effect on the optoelectronic properties of small molecules. Theoretical simulation and X-ray diffraction study reveal the subtle tuning of interchain distance between conjugated backbones has large effect on the charge transport and thus the photovoltaic performance of these molecules. Bulk-heterojunction solar cells fabricated with a configuration of ITO/PEDOT:PSS/SM:PC71BM/PFN/Al exhibit a highest power conversion efficiency (PCE) of 6.99% after solvent vapor annealing. PMID:27140224

  17. Side-chain Engineering of Benzo[1,2-b:4,5-b']dithiophene Core-structured Small Molecules for High-Performance Organic Solar Cells.

    PubMed

    Yin, Xinxing; An, Qiaoshi; Yu, Jiangsheng; Guo, Fengning; Geng, Yongliang; Bian, Linyi; Xu, Zhongsheng; Zhou, Baojing; Xie, Linghai; Zhang, Fujun; Tang, Weihua

    2016-01-01

    Three novel small molecules have been developed by side-chain engineering on benzo[1,2-b:4,5-b']dithiophene (BDT) core. The typical acceptor-donor-acceptor (A-D-A) structure is adopted with 4,8-functionalized BDT moieties as core, dioctylterthiophene as π bridge and 3-ethylrhodanine as electron-withdrawing end group. Side-chain engineering on BDT core exhibits small but measurable effect on the optoelectronic properties of small molecules. Theoretical simulation and X-ray diffraction study reveal the subtle tuning of interchain distance between conjugated backbones has large effect on the charge transport and thus the photovoltaic performance of these molecules. Bulk-heterojunction solar cells fabricated with a configuration of ITO/PEDOT:PSS/SM:PC71BM/PFN/Al exhibit a highest power conversion efficiency (PCE) of 6.99% after solvent vapor annealing. PMID:27140224

  18. Comparison of properties of small-scale ion flux fluctuations in the flank magnetosheath and in the solar wind

    NASA Astrophysics Data System (ADS)

    Riazantseva, M. O.; Budaev, V. P.; Rakhmanova, L. S.; Zastenker, G. N.; Šafránková, J.; Němeček, Z.; Přech, L.

    2016-07-01

    We present a comparison of spectral and statistical properties of ion flux fluctuations in the turbulent solar wind and in the flank Earth's magnetosheath. We use the data of the BMSW device operating in frame of the SPECTR-R mission with an extremely high-time resolution (up to ∼30 ms). Fourier spectra of ion flux fluctuations are systematically analyzed both in the solar wind and in the magnetosheath on the inertial scale and on a transition to the dissipation scale in the range of 0.01-10 Hz. We show that ion flux fluctuation spectra in the flank magnetosheath are similar to those observed in the solar wind and we demonstrate the presence of the break at frequencies of ∼1-2 Hz. Spectra are slightly steeper in the flank magnetosheath but the break frequency is near twice less in a comparison to the solar wind. The magnetosheath ion flux turbulent flow is intermittent as it was shown earlier for the solar wind. We discuss the level of intermittency of ion flux fluctuations in both regions and we determine the characteristics of structure functions. Finally, we demonstrate extended self-similarity in the magnetosheath.

  19. AN OVERVIEW OF THE U.S. ENVIRONMENTAL PROTECTION AGENCY'S SMALL SYSTEMS RESEARCH AND DEVELOPMENT CENTER AT THE EPA TEST AND EVALUATION FACILITY IN CINCINNATI, OHIO

    EPA Science Inventory

    The U.S. Environmental Protection Agency (U.S. EPA) landmark Safe Drinking Water Act Amendments of 1996 promised to bring and provide safe drinking water to all Americans. Since that time many have not understood or appreciated EPA involvement in the research and development (...

  20. EPA (ENVIRONMENTAL PROTECTION AGENCY) COMPLEX TERRAIN MODEL DEVELOPMENT DESCRIPTION OF A COMPUTER DATA BASE FROM SMALL HILL IMPACTION STUDY NO. 1, CINDER CONE BUTTE, IDAHO

    EPA Science Inventory

    As part of the U.S. Environmental Protection Agency's effort to develop and demonstrate a reliable model of atmospheric dispersion for pollutant emissions in irregular mountainous terrain, the Complex Terrain Model Development Program was initiated. The first phase, a comprehensi...

  1. The dish-Rankine SCSTPE program (Engineering Experiment no. 1). [systems engineering and economic analysis for a small community solar thermal electric system

    NASA Technical Reports Server (NTRS)

    Pons, R. L.; Grigsby, C. E.

    1980-01-01

    Activities planned for phase 2 Of the Small Community Solar Thermal Power Experiment (PFDR) program are summarized with emphasis on a dish-Rankine point focusing distributed receiver solar thermal electric system. Major design efforts include: (1) development of an advanced concept indirect-heated receiver;(2) development of hardware and software for a totally unmanned power plant control system; (3) implementation of a hybrid digital simulator which will validate plant operation prior to field testing; and (4) the acquisition of an efficient organic Rankine cycle power conversion unit. Preliminary performance analyses indicate that a mass-produced dish-Rankine PFDR system is potentially capable of producing electricity at a levelized busbar energy cost of 60 to 70 mills per KWh and with a capital cost of about $1300 per KW.

  2. Deciphering solar magnetic activity. I. On the relationship between the sunspot cycle and the evolution of small magnetic features

    SciTech Connect

    McIntosh, Scott W.; Wang, Xin; Markel, Robert S.; Thompson, Michael J.; Leamon, Robert J.; Malanushenko, Anna V.; Davey, Alisdair R.; Howe, Rachel; Krista, Larisza D.; Cirtain, Jonathan W.; Gurman, Joseph B.; Pesnell, William D.

    2014-09-01

    Sunspots are a canonical marker of the Sun's internal magnetic field which flips polarity every ∼22 yr. The principal variation of sunspots, an ∼11 yr variation, modulates the amount of the magnetic field that pierces the solar surface and drives significant variations in our star's radiative, particulate, and eruptive output over that period. This paper presents observations from the Solar and Heliospheric Observatory and Solar Dynamics Observatory indicating that the 11 yr sunspot variation is intrinsically tied to the spatio-temporal overlap of the activity bands belonging to the 22 yr magnetic activity cycle. Using a systematic analysis of ubiquitous coronal brightpoints and the magnetic scale on which they appear to form, we show that the landmarks of sunspot cycle 23 can be explained by considering the evolution and interaction of the overlapping activity bands of the longer-scale variability.

  3. Perovskite Solar Cells: Moth-Eye TiO2 Layer for Improving Light Harvesting Efficiency in Perovskite Solar Cells (Small 18/2016).

    PubMed

    Kang, Seong Min; Jang, Segeun; Lee, Jong-Kwon; Yoon, Jungjin; Yoo, Dong-Eun; Lee, Jin-Wook; Choi, Mansoo; Park, Nam-Gyu

    2016-05-01

    A moth-eye patterned mesoporous (mp) TiO2 layer is fabricated in the form of submicron scale by using lithography, nano-imprinting and polydimethyl siloxane (PDMS) stamping methods. On page 2443, M. Choi, N.-G. Park, and co-workers demonstrate an excellent light harvesting property of perovskite solar cell by employing the moth-eye nanostructured mp-TiO2 film. These novel fabrication methods are expected to be optically beneficial to opto-electronic devices. PMID:27151831

  4. Enhancement of the photovoltaic performance in P3HT: PbS hybrid solar cells using small size PbS quantum dots

    SciTech Connect

    Firdaus, Yuliar; Van der Auweraer, Mark; Vandenplas, Erwin; Gehlhaar, Robert; Cheyns, David; Justo, Yolanda; Hens, Zeger

    2014-09-07

    Different approaches of surface modification of the quantum dots (QDs), namely, solution-phase (octylamine, octanethiol) and post-deposition (acetic acid, 1,4-benzenedithiol) ligand exchange were used in the fabrication of hybrid bulk heterojunction solar cell containing poly (3-hexylthiophene) (P3HT) and small (2.4 nm) PbS QDs. We show that replacing oleic acid by shorter chain ligands improves the figures of merit of the solar cells. This can possibly be attributed to a combination of a reduced thickness of the barrier for electron transfer and an optimized phase separation. The best results were obtained for post-deposition ligand exchange by 1,4-benzenedithiol, which improves the power conversion efficiency of solar cells based on a bulk heterojunction of lead sulfide (PbS) QDs and P3HT up to two orders of magnitude over previously reported hybrid cells based on a bulk heterojunction of P3HT:PbS QDs, where the QDs are capped by acetic acid ligands. The optimal performance was obtained for solar cells with 69 wt. % PbS QDs. Besides the ligand effects, the improvement was attributed to the formation of an energetically favorable bulk heterojunction with P3HT, when small size (2.4 nm) PbS QDs were used. Dark current density-voltage (J-V) measurements carried out on the device provided insight into the working mechanism: the comparison between the dark J-V characteristics of the bench mark system P3HT:PCBM and the P3HT:PbS blends allows us to conclude that a larger leakage current and a more efficient recombination are the major factors responsible for the larger losses in the hybrid system.

  5. The ADAHELI Solar Mission

    NASA Astrophysics Data System (ADS)

    Berrilli, F.; Velli, M.; Roselli, L.; Bigazzi, A.; Moretti, P. F.; Romoli, M.; Orsini, S.; Cavallini, F.; Greco, V.; Carbone, V.; Consolini, G.; Di Mauro, M. P.; Ermolli, I.; Pietropaolo, E.; Romano, P.; Ventura, P.; White, S. M.; Zuccarello, F.; Cauzzi, G.; Valdettaro, L.

    2008-09-01

    ADAHELI (Advanced Astronomy for HELIOphysics) is an Italian Space project for the investigation of solar photospheric and chromospheric dynamics, via high-resolution spectro-polarimetric observations in the near-infrared spectral range. The mission has been financed for phase A study in the framework of ASI Italian Space Agency Small Missions Program call of September 2007. Four fields have been selected to highlight the specific benefits of ADAHELI scientific payload: 1) Photospheric and chromospheric dynamics and structure, 2) Emergence and evolution of solar active regions and solar irradiance, 3) Chromospheric and corona heating and turbulence, 4) Solar flares in the millimeter wavelength region. The principal science instrument, ISODY, is a 50 cm solar telescope equipped with an innovative Focal Plane Suite composed of a spectro-polarimetric imager, based upon two Fabry-Perot interferometers operating in the NIR regions around 845nm and 1083nm, a broad band imager, and a correlation tracker used as image stabilization system. Designed Mission Profiles for ADAHELI intend to achieve continuous high-spectral and spatial resolution observations of the Sun for a routine duration of 4 hours with a goal to be extended to 24 hours. ADAHELI also carries MIOS, a millimeter wavelengths radiometer operating at around 90 GHz for flare detection. The ADAHELI payload's instrument suite integrates and complements, without overlap, the present major objectives of ESA, NASA and the International Living with a Star program, in particular Solar Dynamics Observatory, PICARD, Solar Orbiter, and the Solar Probe missions. Proposals for optional instruments are also under evaluation: DIMMI-2h, a double channel MOF based full disk imager operating at 589nm and 770nm, allowing high temporal resolution velocity and magnetic field measurements; EISR a two channel spectrometer operating in the 50-130 nm wavelength range, and NPA, an in-situ Neutral Particle Analyzer to detect Energetic

  6. Power and Efficiency Analysis of a Solar Central Receiver Combined Cycle Plant with a Small Particle Heat Exchanger Receiver

    NASA Astrophysics Data System (ADS)

    Virgen, Matthew Miguel

    Two significant goals in solar plant operation are lower cost and higher efficiencies. To achieve those goals, a combined cycle gas turbine (CCGT) system, which uses the hot gas turbine exhaust to produce superheated steam for a bottoming Rankine cycle by way of a heat recovery steam generator (HRSG), is investigated in this work. Building off of a previous gas turbine model created at the Combustion and Solar Energy Laboratory at SDSU, here are added the HRSG and steam turbine model, which had to handle significant change in the mass flow and temperature of air exiting the gas turbine due to varying solar input. A wide range of cases were run to explore options for maximizing both power and efficiency from the proposed CSP CCGT plant. Variable guide vanes (VGVs) were found in the earlier model to be an effective tool in providing operational flexibility to address the variable nature of solar input. Combined cycle efficiencies in the range of 50% were found to result from this plant configuration. However, a combustor inlet temperature (CIT) limit leads to two distinct Modes of operation, with a sharp drop in both plant efficiency and power occurring when the air flow through the receiver exceeded the CIT limit. This drawback can be partially addressed through strategic use of the VGVs. Since system response is fully established for the relevant range of solar input and variable guide vane angles, the System Advisor Model (SAM) from NREL can be used to find what the actual expected solar input would be over the course of the day, and plan accordingly. While the SAM software is not yet equipped to model a Brayton cycle cavity receiver, appropriate approximations were made in order to produce a suitable heliostat field to fit this system. Since the SPHER uses carbon nano-particles as the solar absorbers, questions of particle longevity and how the particles might affect the flame behavior in the combustor were addressed using the chemical kinetics software Chemkin

  7. Phase 1 of the First Small Power System Experiment (engineering Experiment No. 1). Volume 2: System Concept Selection. [development and testing of a solar thermal power plant

    NASA Technical Reports Server (NTRS)

    Holl, R. J.

    1979-01-01

    The development of a modular solar thermal power system for application in the 1 to 10 MWe range is presented. The system is used in remote utility applications, small communities, rural areas, and for industrial uses. Systems design and systems optimization studies are conducted which consider plant size, annual capacity factors, and startup time as variables. Investigations are performed on the energy storage requirements and type of energy storage, concentrator design and field optimization, energy transport, and power conversion subsystems. The system utilizes a Rankine cycle, an axial flow steam turbine for power conversion, and heat transfer sodium for collector fluid.

  8. A search for small solar-system bodies near the earth using a ground-based telescope - Technique and observations

    NASA Astrophysics Data System (ADS)

    Frank, L. A.; Sigwarth, J. B.; Yeates, C. M.

    1990-02-01

    A large, previously undetected flux of small bodies near earth is identified by employing the standard technique of detection of an individual object in two consecutive frames. The observational periods and viewing coordinates for the search for small bodies are presented. A null test is performed in order to further demonstrate that the signatures in the images are not due to instrumental artifacts. The observed fluxes, orbital motions, and radii of the small bodies detected are in agreement with those for the small cometlike objects previously reported. It is pointed out that the radii of the small bodies would be in the range of meters. Since an alternative interpretation of the small bodies is possible, it is suggested that the use of a telescope with larger aperture and/or array detectors with lesser noise levels is necessary to confirm the present observations.

  9. A search for small solar-system bodies near the earth using a ground-based telescope - Technique and observations

    NASA Technical Reports Server (NTRS)

    Frank, L. A.; Sigwarth, J. B.; Yeates, C. M.

    1990-01-01

    A large, previously undetected flux of small bodies near earth is identified by employing the standard technique of detection of an individual object in two consecutive frames. The observational periods and viewing coordinates for the search for small bodies are presented. A null test is performed in order to further demonstrate that the signatures in the images are not due to instrumental artifacts. The observed fluxes, orbital motions, and radii of the small bodies detected are in agreement with those for the small cometlike objects previously reported. It is pointed out that the radii of the small bodies would be in the range of meters. Since an alternative interpretation of the small bodies is possible, it is suggested that the use of a telescope with larger aperture and/or array detectors with lesser noise levels is necessary to confirm the present observations.

  10. A small-scale H-alpha eruption in the north polar limb of the Sun observed by New Solar Telescope

    NASA Astrophysics Data System (ADS)

    Kim, Y.-H.; Park, Y.-D.; Bong, S.-Ch.; Cho, K.-S.; Chae, J.

    2010-12-01

    The 1.6 m New Solar Telescope (NST) at Big Bear Solar Observatory (BBSO) is the recently constructed world's largest optical solar telescope on the ground. Up to date it has been partly operated, i.e., observations that have been made at Nasmyth focus only without adaptive optic (AO) system. The AO system is planned to be installed this summer. Using the NST, we have observed the north polar limb in H-alpha line center wavelength on 2009 August 26. A remarkable H-alpha eruption was observed from 18:20 UT to 18:45 UT with a relatively slower speed of about 10 km/s in its early stage. The eruption was then slightly accelerated up to 20-30 km/s and appeared to be deflected along the pre-existing magnetic field. The eruption also showed several interesting characteristics such as bifurcation, rotation, horizontal oscillation, and direction and thickness changes of its structure during its evolution. In this talk, we report on the observational properties of the small-scale eruption observed by the NST and discuss their implications for magnetic reconnection.

  11. Investigations on physics of planetary atmospheres and small bodies of the Solar system, extrasolar planets and disk structures around the stars

    NASA Astrophysics Data System (ADS)

    Vidmachenko, A. P.; Delets, O. S.; Dlugach, J. M.; Zakhozhay, O. V.; Kostogryz, N. M.; Krushevska, V. M.; Kuznyetsova, Y. G.; Morozhenko, O. V.; Nevodovskyi, P. V.; Ovsak, O. S.; Rozenbush, O. E.; Romanyuk, Ya. O.; Shavlovskiy, V. I.; Yanovitskij, E. G.

    2015-12-01

    The history and main becoming stages of Planetary system physics Department of the Main astronomical observatory of National academy of Sciences of Ukraine are considered. Fundamental subjects of department researches and science achievements of employees are presented. Fields of theoretical and experimental researches are Solar system planets and their satellites; vertical structures of planet atmospheres; radiative transfer in planet atmospheres; exoplanet systems of Milky Way; stars having disc structures; astronomical engineering. Employees of the department carry out spectral, photometrical and polarimetrical observations of Solar system planets, exoplanet systems and stars with disc structures. 1. From the history of department 2. The main directions of department research 3. Scientific instrumentation 4. Telescopes and observation stations 5. Theoretical studies 6. The results of observations of planets and small Solar system bodies and their interpretation 7. The study of exoplanets around the stars of our galaxy 8. Spectral energy distribution of fragmenting protostellar disks 9. Cooperation with the National Technical University of Ukraine (KPI) and National University of Ukraine "Lviv Polytechnic" to study the impact of stratospheric aerosol changes on weather and climate of the Earth 10. International relations. Scientific and organizational work. Scientific conferences, congresses, symposia 11. The main achievements of the department 12. Current researches 13. Anniversaries and awards

  12. Solar wind interaction with small bodies. 2: What can Galileo's detection of magnetic rotations tell us about Gaspra and Ida

    NASA Technical Reports Server (NTRS)

    Kivelson, M. G.; Wang, Z.; Joy, S.; Khurana, K. K.; Polanskey, C.; Southwood, D. J.; Walker, R. J.

    1995-01-01

    As the Galileo spacecraft passed the asteroids Gaspra in 1990 and Ida in 1993, the magnetometer recorded changes in the solar wind magnetic field that we associate with the presence of the nearby body. This paper focuses on the types of interactions that can produce perturbations in the solar wind. We have suggested that the interaction at Gaspra is consistent with expectations of flow diversion by a magnetic dipole moment and an associated 'magnetosphere' whose scale size is much larger than the diameter of the solid body. The conditions for the Ida flyby leave more room for ambiguity. The observations could plausibly be related to either interaction with a magnetized body or with a conducting body. We will report on details of the observations that may enable us to distinguish between the different types of interaction and to provide quantitative estimates of the physical properties of the asteroids themselves.

  13. Entry of solar-wind ions into the wake of a small body with a magnetic anomaly: A global Vlasov simulation

    NASA Astrophysics Data System (ADS)

    Umeda, Takayuki; Ito, Yosuke

    2014-04-01

    The interaction between a plasma flow and a small dielectric body with a weak intrinsic global magnetic field is studied by means of a five-dimensional full electromagnetic Vlasov simulation with two configuration spaces and three velocity spaces. In the present study, entry processes of ions into the nightside wake tail are examined. The simulation result shows that the bow shock and the magnetopause are formed on the dayside. However, most of solar-wind ions are reflected at the dayside magnetopause and are picked up by the interplanetary magnetic field. Then, a small part of the reflected ions are taken into the deep wake tail near the body by the E×B cycloid motion.

  14. D-A-D-π-D-A-D type diketopyrrolopyrrole based small molecule electron donors for bulk heterojunction organic solar cells.

    PubMed

    Patil, Yuvraj; Misra, Rajneesh; Sharma, Abhishek; Sharma, Ganesh D

    2016-06-22

    Two organic small molecules based on diketopyrrolopyrrole (DPP) units having a D-A-D-π-D-A-D structure denoted as and were synthesized. Their optical and electrochemical properties relevant to organic solar cells were investigated. The wider optical absorption coverage from 450-800 nm, the highest occupied molecular orbital (HOMO) (-5.23 eV and -5.34 eV for and , respectively) and the lowest unoccupied molecular orbital (LUMO) (-3.47 and -3.45 eV for and , respectively) make these small molecules suitable as donors for bulk heterojunction organic solar cells. The bulk heterojunction (BHJ) organic solar cells based on an active layer consists of a blend of these small molecules as donors and PC71BM as an acceptor with an optimized weight ratio of 1 : 2 cast from chloroform (CF) showed overall power conversion efficiencies (PCEs) of 1.98% (with Jsc = 5.38 mA cm(-2), Voc = 0.84 V and FF = 0.42) and 1.85% (with Jsc = 4.56 mA cm(-2), Voc = 0.96 V and FF = 0.42) for and respectively. The relatively high Voc value based on the based device has been attributed to the deeper HOMO of compared to . The optimized  : PC71BM (1 : 2) and  : PC71BM (1 : 2) active layers were subjected to two step annealing (TSA), i.e. thermal annealing and subsequent solvent vapor annealing and the corresponding BHJ organic solar cells showed a PCE of 5.28% (Jsc = 11.53 mA cm(-2), Voc = 0.79 V and FF = 0.58) and 5.52% (Jsc = 10.84 mA cm(-2), Voc = 0.91 V and FF = 0.56), respectively. The enhancement in PCE is mainly due to the improvement in Jsc and FF, related to light absorption in an active layer, a better nanoscale morphology, and an increase in the crystalline nature of the active layer and balanced charge transport, induced by the TSA treatment. PMID:27292157

  15. Rational design of tetraphenylethylene-based luminescent down-shifting molecules: photophysical studies and photovoltaic applications in a CdTe solar cell from small to large units.

    PubMed

    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. PMID:25363326

  16. The solar and interplanetary causes of the recent minimum in geomagnetic activity (MGA23): a combination of midlatitude small coronal holes, low IMF BZ variances, low solar wind speeds and low solar magnetic fields

    NASA Astrophysics Data System (ADS)

    Tsurutani, B. T.; Echer, E.; Gonzalez, W. D.

    2011-05-01

    Minima in geomagnetic activity (MGA) at Earth at the ends of SC23 and SC22 have been identified. The two MGAs (called MGA23 and MGA22, respectively) were present in 2009 and 1997, delayed from the sunspot number minima in 2008 and 1996 by ~1/2-1 years. Part of the solar and interplanetary causes of the MGAs were exceptionally low solar (and thus low interplanetary) magnetic fields. Another important factor in MGA23 was the disappearance of equatorial and low latitude coronal holes and the appearance of midlatitude coronal holes. The location of the holes relative to the ecliptic plane led to low solar wind speeds and low IMF (Bz) variances (σBz2) and normalized variances (σBz2/B02) at Earth, with concomitant reduced solar wind-magnetospheric energy coupling. One result was the lowest ap indices in the history of ap recording. The results presented here are used to comment on the possible solar and interplanetary causes of the low geomagnetic activity that occurred during the Maunder Minimum.

  17. Small-scale filament eruptions as the driver of X-ray jets in solar coronal holes.

    PubMed

    Sterling, Alphonse C; Moore, Ronald L; Falconer, David A; Adams, Mitzi

    2015-07-23

    Solar X-ray jets are thought to be made by a burst of reconnection of closed magnetic field at the base of a jet with ambient open field. In the accepted version of the 'emerging-flux' model, such a reconnection occurs at a plasma current sheet between the open field and the emerging closed field, and also forms a localized X-ray brightening that is usually observed at the edge of the jet's base. Here we report high-resolution X-ray and extreme-ultraviolet observations of 20 randomly selected X-ray jets that form in coronal holes at the Sun's poles. In each jet, contrary to the emerging-flux model, a miniature version of the filament eruptions that initiate coronal mass ejections drives the jet-producing reconnection. The X-ray bright point occurs by reconnection of the 'legs' of the minifilament-carrying erupting closed field, analogous to the formation of solar flares in larger-scale eruptions. Previous observations have found that some jets are driven by base-field eruptions, but only one such study, of only one jet, provisionally questioned the emerging-flux model. Our observations support the view that solar filament eruptions are formed by a fundamental explosive magnetic process that occurs on a vast range of scales, from the biggest mass ejections and flare eruptions down to X-ray jets, and perhaps even down to smaller jets that may power coronal heating. A similar scenario has previously been suggested, but was inferred from different observations and based on a different origin of the erupting minifilament. PMID:26147079

  18. EPA (ENVIRONMENTAL PROTECTION AGENCY) COMPLEX TERRAIN MODEL DEVELOPMENT: DESCRIPTION OF A COMPUTER DATA BASE FROM SMALL HILL IMPACTION STUDY NO. 2, HOGBACK RIDGE, NEW MEXICO

    EPA Science Inventory

    The second field study of EPA's Complex Terrain Model Development Program, Small Hill Impaction Study No. 2, was conducted along a 1.5-km section of the Hogback Ridge near Farmington, New Mexico in October 1982. Eleven quantative tracer experiments were performed, each lasting 8 ...

  19. Sexual Behavior, Mental Health, Substance Use, and HIV Risk Among Agency-Based Male Escorts in a Small U.S. City

    PubMed Central

    Smith, Michael D.; Seal, D. W.

    2009-01-01

    Relatively little research has examined the personal sex lives of indoor male sex workers (MSWs) or possible connections in this group between sexual behavior and factors related to HIV risk. As part of a larger project, this study collected data from 30 agency-based indoor MSWs (mean = 22.4 years) about their sexual behavior, mental health, and substance use. Few HIV risk behaviors with clients occurred. Drug use and mental health problems were relatively frequent, but not related to increased risk behavior. Instead, MSWs appeared to employ rational decision-making and harm-reduction strategies. Conceptualization of MSW sexual behavior may be required where HIV risk is not attributed to sex work per se, but to other influences such as economic and relational factors. PMID:19779600

  20. Wireless data communication alternatives for small public safety agencies: how one community cost-effectively solved its expanding field data requirements

    NASA Astrophysics Data System (ADS)

    Canning, Ryan M.; Lefebvre, Eric

    2005-06-01

    A growing number of Public Safety agencies have begun leveraging wireless data communication technology to improve tactical response capabilities as well as overall productivity. For years police departments subscribed to CDPD (Cellular Digital Packet Data) services to provide officers with basic dispatch data and criminal database access. Now as cellular carriers have deactivated CDPD and shifted to 2.5G and 3G data services such as 1xRTT, GPRS and EDGE, police departments are scrambling to fill the void. Not surprisingly, the extraordinary investments cellular carriers made to upgrade their infrastructures have been transferred to the customer, with monthly fees running as high as $80 a month per user. It's no wonder public safety agencies have been reluctant to adopt these services. Lost in the fray are those smaller police departments which account for nearly 90% of the nation's total. This group has increasingly sought out alternative data communication solutions that are not predicated on budget-busting monthly access fees. One such example is the Marco Island Police Department (MIPD) in Southwestern Florida that received a Federal grant to augment its existing voice communications with data. After evaluating several different technologies and vendors, MIPD chose a 900 MHz ad hoc mesh network solution based on its ability to provide reliable, high-speed and secure IP-based data communications over extensive distances. This paper will discuss technical details of Marco Island's mobile mesh network implementation; including: coverage area with 900 MHz spread spectrum radios, strategic repeater tower placement, interference, throughput performance, and the necessity for application-persistence software.

  1. Solution-Processable Small Molecules for High-Performance Organic Solar Cells with Rigidly Fluorinated 2,2'-Bithiophene Central Cores.

    PubMed

    Wang, Zhenguo; Li, Zuojia; Liu, Jiang; Mei, Jun; Li, Kai; Li, Ying; Peng, Qiang

    2016-05-11

    Small molecules containing an oligothiophene backbone are simple but effective donor materials for organic solar cells (OSCs). In this work, we incorporated rigid 2,2'-bithiophene (BT) or fluorinated 2,2'-bithiophene (FBT) as the central unit and synthesized two novel small molecules (TTH-D3TRh and TTF-D3TRh) with an oligothiophene backbone and 3-ethylrhodanine end groups. Both molecules exhibit good thermal stability as well as strong and broad absorption. The fluorination of the BT central unit made TTF-D3TRh possess a relatively lower-lying HOMO energy level, better molecular stacking, and higher mobility in comparison with those of TTH-D3TRh. Conventional OSCs were fabricated to evaluate the photovoltaic property of these two molecules. Without extra post-treatments, the conventional devices based on TTH-D3TRh and TTF-D3TRh showed high PCEs of 5.00 and 5.80%, respectively. The TTF-D3TRh device exhibited a higher performance, which can be attributed to the improved Voc of 0.92 V, Jsc of 10.04 mA cm(-2), and FF of 62.8%. Using an inverted device structure, the OSCs based on TTH-D3TRh and TTF-D3TRh showed largely elevated PCEs of 5.89 and 7.14%, respectively. The results indicated that the structurally simple TTH-D3TRh and TTF-D3TR molecules are potential donor candidates for achieving highly efficient OSCs. The strategy of fluorination and rigidity designation is an effective approach to develop oligothiophene-based small molecular donors for highly efficient solar cell applications. PMID:27097642

  2. SUCCESSIVE SOLAR ERUPTIONS TRIGGERED BY THE COLLISION OF TWO SMALL SUNSPOTS WITH OPPOSITE POLARITIES AND MOTIONAL DIRECTIONS

    SciTech Connect

    Yan, X. L.; Qu, Z. Q.; Kong, D. F.

    2012-03-15

    We present a study of the two successive M-class flares associated with two coronal mass ejections (CMEs) triggered by the collision of two small sunspots with opposite magnetic polarities and motional directions in NOAA active region (AR) 10484 on 2003 October 22. From the evolution of this AR in the TRACE white-light images and 96 minute line-of-sight magnetograms observed by the Michelson Doppler Imager on board SOHO, a large sunspot and a small sunspot with negative polarity rotated clockwise about 33 Degree-Sign and 18 Degree-Sign , respectively, from the northeast of a quiescent sunspot with negative polarity to the southeast from 15:00 UT on October 21 to 16:24 UT on October 23. During the process of their motion, the small sunspot with negative polarity collided with the small sunspot with positive polarity and opposite motional direction. In the collision, this AR produced two successive M-class flares and CMEs according to the observations of GOES and the Large Angle and Spectrometric Coronagraph. By analyzing the magnetic fields at polarity inversion lines (PILs) between the two small sunspot, it is found that a sudden squeeze occurred near the onset of the two M-class flares and then recovered itself after the flares. We ruled out the emergence of the magnetic fields near the PIL. According to the brightenings in TRACE 1600 A and the hard X-ray sources of the RHESSI of two M-class flares, we found that the locations of the two flares are almost situated in the same location at the PIL between the two small sunspots. We suggest that the sudden squeeze between the opposite magnetic polarities is caused by the pressure of the collision of the two small sunspots and resulted in the magnetic reconnection. These results could contribute to understanding the mechanism of flares and CMEs.

  3. Assessment of potential for small hydro/solar power integration in a mountainous, data sparse region: the role of hydrological prediction accuracy

    NASA Astrophysics Data System (ADS)

    Borga, Marco; Francois, Baptiste; Creutin, Jean-Dominique; Hingray, Benoit; Zoccatelli, Davide; Tardivo, Gianmarco

    2015-04-01

    In many parts of the world, integration of small hydropower and solar/wind energy sources along river systems is examined as a way to meet pressing renewable energy targets. Depending on the space and time scales considered, hydrometeorological variability may synchronize or desynchronize solar/wind, runoff and the demand opening the possibility to use their complementarity to smooth the intermittency of each individual energy source. Rivers also provide important ecosystem services, including the provision of high quality downstream water supply and the maintenance of in-stream habitats. With future supply and demand of water resources both impacted by environmental change, a good understanding of the potential for the integration among hydropower and solar/wind energy sources in often sparsely gauged catchments is important. In such cases, where complex data-demanding models may be inappropriate, there is a need for simple conceptual modelling approaches that can still capture the main features of runoff generation and artificial regulation processes. In this work we focus on run-of-the-river and solar-power interaction assessment. In order to catch the three key cycles of the load fluctuation - daily, weekly and seasonal, the time step used in the study is the hourly resolution. We examine the performance of a conceptual hydrological model which includes facilities to model dam regulation and diversions and hydrological modules to account for the effect of glaciarised catchments. The model is applied to catchments of the heavily regulated Upper Adige river system (6900 km2), Eastern Italian Alps, which has a long history of hydropower generation. The model is used to characterize and predict the natural flow regime, assess the regulation impacts, and simulate co-fluctuations between run-of- the-river and solar power. The results demonstrates that the simple, conceptual modelling approach developed here can capture the main hydrological and regulation processes

  4. Recombination in Organic Bulk Heterojunction Solar Cells: Small Dependence of Interfacial Charge Transfer Kinetics on Fullerene Affinity.

    PubMed

    Guerrero, Antonio; Marchesi, Luis F; Boix, Pablo P; Bisquert, Juan; Garcia-Belmonte, Germa

    2012-05-17

    We investigate the causes for obtaining higher open-circuit voltage in solar cells that use a fullerene with a smaller electron affinity. Using impedance spectroscopy technique, we show that the change of fullerene LUMO energy has very little influence on the kinetic rate of charge transfer across the interface. In terms of the Marcus theory, large reorganization energy values govern the recombination kinetic rate, which is only slightly dependent on the fullerene LUMO energy, and also depends weakly on the energy location of recombining carriers within the broad density of states. Since the recombination rate is very similar in the different devices, we conclude that the larger open-circuit voltage is due to the larger donor HOMO/acceptor LUMO offset. PMID:26286787

  5. A portable electrospinning apparatus based on a small solar cell and a hand generator: design, performance and application.

    PubMed

    Yan, Xu; Yu, Miao; Zhang, Li-Hua; Jia, Xian-Sheng; Li, Jin-Tao; Duan, Xiao-Peng; Qin, Chong-Chong; Dong, Rui-Hua; Long, Yun-Ze

    2016-01-01

    Electrospinning (e-spinning) devices and electrospun (e-spun) ultrathin fibers have shown promising applications in various fields. However, the poor portability of conventional e-spinning devices limits some potential applications especially in the case without a plug (electricity supply). Consequently, great efforts have been made to modify e-spinning setups with good portability. In this article, a solar cell and a hand generator-powered portable e-spinning (SHPE) setup with good flexibility is introduced, which can be used outdoors without a plug. The SHPE device shows good spinning efficacy both in solution and melt e-spinning processes for a wide range of polymers. Moreover, the designed SHPE apparatus demonstrates potential application in wound dressing by in situ e-spinning fibers onto human skin directly. PMID:26645101

  6. Modifying Poly(Vinyl Alcohol) (PVA) from Insulator to Small-Bandgap Polymer: A Novel Approach for Organic Solar Cells and Optoelectronic Devices

    NASA Astrophysics Data System (ADS)

    Aziz, Shujahadeen B.

    2016-01-01

    An innovative method has been used to reduce the bandgap of poly(vinyl alcohol) (PVA) polymer by addition of a nontoxic, inexpensive, and environmentally friendly material. The resulting materials are small-bandgap polymers, hence opening new frontiers in green chemistry. The doped PVA films showed a wide range of light absorption of the solar spectrum from 200 nm to above 800 nm. Nonsharp absorption behavior versus wavelength was observed for the samples. The refractive index exhibited a wide range of dispersion. Shift of the absorption edge from 6.2 eV to 1.5 eV was observed. The energy bandgap of PVA was diminished to 1.85 eV upon addition of black tea extract solution, lying in the range of small-bandgap polymers. Increase of the optical dielectric constant was observed with increasing tea solution addition. The results indicate that small-bandgap PVA with good film-forming ability could be useful in terms of cost-performance tradeoff, solving problems of short lifetime, cost, and flexibility associated with conjugated polymers. The decrease of the Urbach energy upon addition of black tea extract solution indicates modification of PVA from a disordered to ordered material. X-ray diffraction results confirm an increase of the crystalline fraction in the doped samples.

  7. Increased Efficiency in Small Molecule Organic Solar Cells Through the Use of a 56-π Electron Acceptor – Methano Indene Fullerene

    PubMed Central

    Ryan, James W.; Matsuo, Yutaka

    2015-01-01

    Organic solar cells (OSCs) offer the possibility of harnessing the sun's ubiquitous energy in a low-cost, environmentally friendly and renewable manner. OSCs based on small molecule semiconductors (SMOSCs) – have made a substantial improvement in recent years and are now achieving power conversion efficiencies (PCEs) that match those achieved for polymer:fullerene OSCs. To date, all efficient SMOSCs have relied on the same fullerene acceptor, PCBM, in order to achieve high performance. The use of PCBM however, is unfavourable due to its low lying LUMO level, which limits the open-circuit voltage (VOC). Alternative fullerene derivatives with higher lying LUMOs are thus required to improve the VOC. The challenge, however, is to prevent the typical concomitant decrease in the short circuit current density (JSC) when using a higher LUMO fullerene. In this communication, we address the issue by applying methano indene fullerene, MIF, a bis-functionalised C60 fullerene that has a LUMO level 140 mV higher than PCBM, in solution processed SMOSCs with a well known small molecule donor, DPP(TBFu)2. MIF-based devices show an improved VOC of 140 mV over PC61BM and only a small decrease in the JSC, with the PCE increasing to 5.1% (vs. 4.5% for PC61BM). PMID:25661976

  8. Enhancement of Performance and Mechanism Studies of All-Solution Processed Small-Molecule based Solar Cells with an Inverted Structure.

    PubMed

    Long, Guankui; Wu, Bo; Yang, Xuan; Kan, Bin; Zhou, Ye-Cheng; Chen, Li-Chuan; Wan, Xiangjian; Zhang, Hao-Li; Sum, Tze Chien; Chen, Yongsheng

    2015-09-30

    Both solution-processed polymers and small molecule based solar cells have achieved PCEs over 9% with the conventional device structure. However, for the practical applications of photovoltaic technology, further enhancement of both device performance and stability are urgently required, particularly for the inverted structure devices, since this architecture will probably be most promising for the possible coming commercialization. In this work, we have fabricated both conventional and inverted structure devices using the same small molecular donor/acceptor materials and compared the performance of both device structures, and found that the inverted structure based device gave significantly improved performance, the highest PCE so far for inverted structure based device using small molecules as the donor. Furthermore, the inverted device shows a remarkable stability with almost no obvious degradation after three months. Systematic device physics and charge generation dynamics studies, including optical simulation, light-intensity-dependent current-voltage experiments, photocurrent density-effective voltage analyses, transient absorption measurements, and electrical simulations, indicate that the significantly enhanced performance using inverted device is ascribed to the increasing of Jsc compared to the conventional device, which in turn is mainly attributed to the increased absorption of photons in the active layers, rather than the reduced nongeminate recombination. PMID:26352703

  9. Intensity dependence of current-voltage characteristics and recombination in high-efficiency solution-processed small-molecule solar cells.

    PubMed

    Kyaw, Aung Ko Ko; Wang, Dong Hwan; Gupta, Vinay; Leong, Wei Lin; Ke, Lin; Bazan, Guillermo C; Heeger, Alan J

    2013-05-28

    Solution-processed small-molecule p-DTS(FBTTh2)2:PC71BM bulk heterojunction (BHJ) solar cells with power conversion efficiency of 8.01% are demonstrated. The fill factor (FF) is sensitive to the thickness of a calcium layer between the BHJ layer and the Al cathode; for 20 nm Ca thickness, the FF is 73%, the highest value reported for an organic solar cell. The maximum external quantum efficiency exceeds 80%. After correcting for the total absorption in the cell through normal incidence reflectance measurements, the internal quantum efficiency approaches 100% in the spectral range of 600-650 nm and well over 80% across the entire spectral range from 400 to 700 nm. Analysis of the current-voltage (J-V) characteristics at various light intensities provides information on the different recombination mechanisms in the BHJ solar cells with different thicknesses of the Ca layer. Our analysis reveals that the J-V curves are dominated by first-order recombination from the short-circuit condition to the maximum power point and evolve to bimolecular recombination in the range of voltage from the maximum power point to the open-circuit condition in the optimized device with a Ca thickness of 20 nm. In addition, the normalized photocurrent density curves reveal that the charge collection probability remains high; about 90% of charges are collected even at the maximum power point. The dominance of bimolecular recombination only when approaching open circuit, the lack of Shockley-Read-Hall recombination at open circuit, and the high charge collection probability (97.6% at the short circuit and constant over wide range of applied voltage) lead to the high fill factor. PMID:23597037

  10. Phase 1 of the First Solar Small Power System Experiment (experimental System No. 1). Volume 1: Technical Studies for Solar Point-focusing, Distributed Collector System, with Energy Conversion at the Collector, Category C

    NASA Technical Reports Server (NTRS)

    Clark, T. B. (Editor)

    1979-01-01

    The technical and economic feasibility of a solar electric power plant for a small community is evaluated and specific system designs for development and demonstration are selected. All systems investigated are defined as point focusing, distributed receiver concepts, with energy conversion at the collector. The preferred system is comprised of multiple parabolic dish concentrators employing Stirling cycle engines for power conversion. The engine, AC generator, cavity receiver, and integral sodium pool boiler/heat transport system are combined in a single package and mounted at the focus of each concentrator. The output of each concentrator is collected by a conventional electrical distribution system which permits grid-connected or stand-alone operation, depending on the storage system selected.

  11. Delivery of Exogenous Complex Organic Compounds by Solar System Small Bodies and Space Dusts and Its Relevance to Origins of Life

    NASA Astrophysics Data System (ADS)

    Kobayashi, Kensei; Fushimi, Hidehiko; Motoyama, Takuya; Kaneko, Takeo; Obayashi, Yumiko; Yoshida, Satoshi; Mita, Hajime; Yabuta, Hikaru; Okudaira, Kyoko; Hashimoto, Hirofumi; Yokobori, Shin-Ichi; Yamagishi, Akihiko

    A wide variety of organic compounds including amino acid precursors have been detected in such extraterrestrial bodies as carbonaceous chondrites and comets. It was suggested that these organics were formed in quite cold environments. We irradiated frozen mixtures of possible constituents of ice mantles of interstellar dust particles including water, methanol and ammonia with high-energy heavy ions from HIMAC, National Institute of Radiological Science, Japan. Amino acid precursors with complex structures were detected whose molecular weights are up to a few thousands. Such complex amino acid precursors are much stronger than free amino acids against radiation. Such organics could have been incorporated in solar system small bodies after the formation of the solar system and delivered to the primitive Earth. Possible carriers of such organics are meteorites, comets and interplanetary dust particles (IDPs) that were formed from comets and meteorites. It is suggested that IDPs brought much more organics than meteorites and comets. However, nature of organics in IDPs is little known, since they have been collected only in terrestrial biosphere. We are planning a space experiments named Tanpopo, where IDPs would be collected in aerogel equipped on the Exposure Facility of the International Space Station. In addition, amino acids and their relating compounds would be exposed to space environments to see their possible alteration processes in the interplanetary space. We will report some preliminary results for the preparation of the mission including the capture of amino acid-containing particles at high velocity with ultra-low density aerogel.

  12. Effects of end-capped acceptors subject to subtle structural changes on solution-processable small molecules for organic solar cells.

    PubMed

    Deng, Dan; Zhang, Yajie; Zhu, Lingyun; Zhang, Jianqi; Lu, Kun; Wei, Zhixiang

    2015-04-14

    Self-assembly is crucial for small molecular organic solar cells, which are extremely sensitive to the molecular structure. In this work, three subtle structural changed end-capped acceptors with increased electron withdrawing ability, named octyl 2-cyanoacetate (=CNCOOC8H17), 3-oxoundecanenitrile (=CNCOC8H17), and 2-(octylsulfonyl) acetonitrile (=CNSOOC8H17), were synthesized and introduced into a planar conjugated backbone using ethylhexyl-thiophene substituted benzodithiophene (TBDT) as a core and trithiophene as a π-bridge (labelled M1, M2 and M3, respectively). Their effects on absorption, thermal properties, and morphologies were studied and compared. In particular, the molecular packing of the three materials varied significantly, and the hole mobilities differed by orders of magnitude. As a result, the fill factors of devices varied from 52% to 72%. Combining the effects of electron-withdrawing capability and molecular packing, the power conversion efficiencies of the optimized devices increased from 3.0% for M3 to 6.4% for M1 and M2. The relationship between end-capped acceptors and photovoltaic properties would generate valuable insights into further producing more efficient solution-processable organic solar cells. PMID:25742902

  13. Comparative analysis of the positional accuracy of CCD measurements of small bodies in the solar system: software CoLiTec and Astrometrica

    NASA Astrophysics Data System (ADS)

    Savanevych, V. E.; Briukhovetskyi, A. B.; Ivashchenko, Yu. N.; Vavilova, I. B.; Bezkrovniy, M. M.; Dikov, E. N.; Vlasenko, V. P.; Sokovikova, N. S.; Movsesian, Ia. S.; Dikhtyar, N. Yu.; Elenin, L. V.; Pohorelov, A. V.; Khlamov, S. V.

    2015-11-01

    The CoLiTec software for the automated search for small celestial objects of the solar system on a series of CCD frames has been developed within the Ukrainian virtual observatory project. Four comets and more than a thousand asteroids were discovered using the software. It was also used to send approximately 700000 positional CCD measurements to the Minor Planet Center. In this paper, accuracy factors of positional CCD measurements using the CoLiTec software are analyzed according to data from the Minor Planet Center. The comparative analysis of these factors according to the results of the processing of the same frames using CoLiTec and Astrometrica software is also conducted. In the case of low signal to noise ratios, the standard deviation of positional CCD measurements using the Astrometrica software is 30-50% greater than that of the CoLiTec software.

  14. Low-latitude Coronal Holes during Solar Maximum

    NASA Astrophysics Data System (ADS)

    Miralles, M.; Cranmer, S.; Kohl, J.

    Analyses of in situ observations have shown that some small coronal holes are sources of slow solar wind near solar maximum when polar coronal holes become smaller and disappear. However, not all coronal holes at solar maximum produce slow wind. The Ultraviolet Coronagraph Spectrometer (UVCS) aboard SOHO has been used to observe large low-latitude coronal holes during solar maximum that produced fast solar wind. UVCS observations show that large equatorial holes at solar maximum have plasma properties that seem to bridge the gap between solar minimum polar coronal holes and streamers. The ion kinetic temperatures in equatorial holes are about 2 times larger than those in a solar minimum equatorial streamer, and about a factor of 2 smaller than those in polar coronal holes above 2 R . The outflow speeds for the large equatorial holes observed by UVCS are only about 100 km s-1 , a factor of 4 smaller than those in polar holes, at 3 R . However, in situ data corresponding to these equatorial coronal holes showed asymptotic wind speeds of 600-700 km s-1 . These wind speeds are similar to those observed over polar coronal holes at solar minimum. In contrast to the polar coronal holes, the bulk of the solar wind acceleration in large equatorial coronal holes at solar maximum must occur above 3 R . Thus, the combination of spectroscopic measurements in the extended corona, where the primary solar wind acceleration occurs, and in situ measurements made in the solar wind can be used to obtain the solar wind acceleration as a function of heliocentric distance. These observations provide detailed empirical constraints for theoretical models and may be key to understanding how the various types of solar wind plasma are heated and accelerated. This work is supported by NASA under Grant NAG5-11420 to the Smithsonian Astrophysical Observatory, by the Italian Space Agency and by PRODEX (Swiss contribution).

  15. Photocatalytic activities of ultra-small β-FeOOH and TiO{sub 2} heterojunction structure under simulated solar irradiation

    SciTech Connect

    Chowdhury, Mahabubur Ntiribinyange, Mary; Nyamayaro, Kudzanai; Fester, Veruscha

    2015-08-15

    Highlights: • Ultra small β-FeOOH with TiO{sub 2} in heterojunction showed good photocatalytic activity under simulated solar irradiation. • Significant improvement of photocatalytic activity compared to pristine TiO{sub 2}. • The as prepared catalyst decoloured industrial textile effluent within 30 min. - Abstract: Photocatalytic performance of β-FeOOH/TiO{sub 2} heterojunction structure, created from ultra-small β-FeOOH nanorods (2–6 nm diameter) and spherical anatase phase of TiO{sub 2} nanoparticles (∼100 nm), is reported in this study. Three different β-FeOOH mol% of (2, 5 and 10%) β-FeOOH/TiO{sub 2} composite was prepared. 5% β-FeOOH/TiO{sub 2} composite material showed the highest photocatalytic activity. XRD, high temperature XRD, FTIR, TEM, UV–vis diffuse reflectance spectra (DRS) were used to characterise the prepared catalyst. The developed catalyst showed excellent photocatalytic activity in photodegradation of methyl orange (MO) than β-FeOOH and TiO{sub 2} under simulated solar irradiation. Two commercial metal complex dyes and real textile effluent were efficiently photodegraded under identical conditions. The developed catalyst exhibited good recyclability without the need of sintering. No significant loss in efficiency was observed during the recycling cycle. These characteristics highlight the potential application of the developed photocatalyst in textile effluent treatment via photocatalysis. The enhanced photocatalytic activity was attributed to the relative energy band positions and very good electron, e{sup −} and hole, h{sup +} conduction ability of TiO{sub 2} and β-FeOOH particles respectively.

  16. The Point-Focusing Thermal and Electric Applications Project - A progress report. [small solar power systems applications

    NASA Technical Reports Server (NTRS)

    Marriott, A. T.

    1979-01-01

    The paper discusses the Point-Focusing Thermal and Electric Applications Project which encompasses three primary activities: (1) applications analysis and development, in which potential markets for small power systems (less than 10 MWe) are identified and characterized in order to provide requirements for design and information for activities relating to market development; (2) systems engineering and development, for analyses that will define the most appropriate small power system designs based on specific user requirements; and (3) experiment implementation and test, which deals with the design and placement of engineering experiments in various applications environments in order to test the readiness of the selected technology in an operational setting. Progress to date and/or key results are discussed throughout the text.

  17. Two-fluid 2.5D code for simulations of small scale magnetic fields in the lower solar atmosphere

    NASA Astrophysics Data System (ADS)

    Piantschitsch, Isabell; Amerstorfer, Ute; Thalmann, Julia Katharina; Hanslmeier, Arnold; Lemmerer, Birgit

    2015-08-01

    Our aim is to investigate magnetic reconnection as a result of the time evolution of magnetic flux tubes in the solar chromosphere. A new numerical two-fluid code was developed, which will perform a 2.5D simulation of the dynamics from the upper convection zone up to the transition region. The code is based on the Total Variation Diminishing Lax-Friedrichs method and includes the effects of ion-neutral collisions, ionisation/recombination, thermal/resistive diffusivity as well as collisional/resistive heating. What is innovative about our newly developed code is the inclusion of a two-fluid model in combination with the use of analytically constructed vertically open magnetic flux tubes, which are used as initial conditions for our simulation. First magnetohydrodynamic (MHD) tests have already shown good agreement with known results of numerical MHD test problems like e.g. the Orszag-Tang vortex test, the Current Sheet test or the Spherical Blast Wave test. Furthermore, the single-fluid approach will also be applied to the initial conditions, in order to compare the different rates of magnetic reconnection in both codes, the two-fluid code and the single-fluid one.

  18. Report From the International Atomic Energy Agency (IAEA) Consultants' Meeting on Elective Nodal Irradiation in Lung Cancer: Non-Small-Cell Lung Cancer (NSCLC)

    SciTech Connect

    Belderbos, Jose; Martel, Mary K.; Videtic, Gregory; Jeremic, Branislav

    2008-10-01

    Lymphatic spread is an important pathway of progression in non-small-cell lung cancer (NSCLC), along with local spread and distant metastasis. The probability of lymph node (LN) involvement is dependent on the site of the primary tumor, stage, and histology. Elective nodal irradiation (ENI) is the irradiation of clinical and radiological uninvolved LN to account for microscopic tumor invasion in these LNs because we have not been able to determine the extent of LN spread accurately. The clinical value of ENI is uncertain. The impact of ENI is dependent on many (staging-, treatment-, and patient-related) factors. The purpose of this report is to analyze the current status of ENI and to provide comprehensive in-depth analysis and guidance on how to generally approach this issue in NSCLC.

  19. Origin of the great dichotomy of the Solar System: small terrestrial embryos and massive giant planet cores

    NASA Astrophysics Data System (ADS)

    Morbidelli, Alessandro; Lambrechts, Michiel; Bitsch, Bertram; Jacobson, Seth

    2015-08-01

    The basic structure of the solar system is set by the presence of low-mass terrestrial planets in its inner part and giant planets in its outer part. This is the result of the formation of a system of multiple Mars-mass embryos in the inner disk and of a few multi-Earth-mass cores in the outer part, within the lifetime of the gaseous component of the protoplanetary disk. What was the origin of this dichotomy in the mass distribution of embryos/cores? We show in this paper that the classic processes of runaway and oligarchic growth from a disk of planetesimals can not explain this dichotomy, even if the original surface density of solids increased at the snowline. Instead, the accretion of drifting pebbles by embryos/cores can explain the dichotomy, provided that some assumptions hold true. We propose that the mass flow of pebbles is two-times lower and the characteristic size of the pebbles is ten times smaller within the snowline than beyond the snowline (respectively at r < r_ice and r > r_ice, where r_ice is the snowline heliocentric distance), due to ice sublimation and the splitting of icy pebbles into a collection of chondrule-size silicate grains. In this case, objects of original sub-lunar mass would grow at drastically different rates in the two regions of the disk. Within the snowline these bodies would reach approximately the mass of Mars while beyond the snowline they would grow to 20 Earth masses. The results may change quantitatively with the assumed parameters, but the establishment of a clear dichotomy in the mass distribution of protoplanets appears robust.

  20. Peculiarity of Two Thermodynamically-Stable Morphologies and Their Impact on the Efficiency of Small Molecule Bulk Heterojunction Solar Cells

    NASA Astrophysics Data System (ADS)

    Herath, Nuradhika; Das, Sanjib; Keum, Jong K.; Zhu, Jiahua; Kumar, Rajeev; Ivanov, Ilia N.; Sumpter, Bobby G.; Browning, James F.; Xiao, Kai; Gu, Gong; Joshi, Pooran; Smith, Sean; Lauter, Valeria

    2015-08-01

    Structural characteristics of the active layers in organic photovoltaic (OPV) devices play a critical role in charge generation, separation and transport. Here we report on morphology and structural control of p-DTS(FBTTh2)2:PC71BM films by means of thermal annealing and 1,8-diiodooctane (DIO) solvent additive processing, and correlate it to the device performance. By combining surface imaging with nanoscale depth-sensitive neutron reflectometry (NR) and X-ray diffraction, three-dimensional morphologies of the films are reconstituted with information extending length scales from nanometers to microns. DIO promotes the formation of a well-mixed donor-acceptor vertical phase morphology with a large population of small p-DTS(FBTTh2)2 nanocrystals arranged in an elongated domain network of the film, thereby enhancing the device performance. In contrast, films without DIO exhibit three-sublayer vertical phase morphology with phase separation in agglomerated domains. Our findings are supported by thermodynamic description based on the Flory-Huggins theory with quantitative evaluation of pairwise interaction parameters that explain the morphological changes resulting from thermal and solvent treatments. Our study reveals that vertical phase morphology of small-molecule based OPVs is significantly different from polymer-based systems. The significant enhancement of morphology and information obtained from theoretical modeling may aid in developing an optimized morphology to enhance device performance for OPVs.

  1. Peculiarity of two thermodynamically-stable morphologies and their impact on the efficiency of small molecule bulk heterojunction solar cells

    SciTech Connect

    Herath, Nuradhika; Das, Sanjib; Keum, Jong K.; Zhu, Jiahua; Kumar, Rajeev; Ivanov, Ilia N.; Sumpter, Bobby G.; Browning, James F.; Xiao, Kai; Gu, Gong; Joshi, Pooran; Smith, Sean; Lauter, Valeria

    2015-08-28

    Structural characteristics of the active layers in organic photovoltaic (OPV) devices play a critical role in charge generation, separation and transport. Here we report on morphology and structural control of p-DTS(FBTTh2)2:PC71BM films by means of thermal annealing and 1,8-diiodooctane (DIO) solvent additive processing, and correlate it to the device performance. By combining surface imaging with nanoscale depth-sensitive neutron reflectometry (NR) and X-ray diffraction, three-dimensional morphologies of the films are reconstituted with information extending length scales from nanometers to microns. DIO promotes the formation of a well-mixed donor-acceptor vertical phase morphology with a large population of small p-DTS(FBTTh2)2 nanocrystals arranged in an elongated domain network of the film, thereby enhancing the device performance. In contrast, films without DIO exhibit three-sublayer vertical phase morphology with phase separation in agglomerated domains. Our findings are supported by thermodynamic description based on the Flory-Huggins theory with quantitative evaluation of pairwise interaction parameters that explain the morphological changes resulting from thermal and solvent treatments. Our study reveals that vertical phase morphology of small-molecule based OPVs is significantly different from polymer-based systems. Lastly, the significant enhancement of morphology and information obtained from theoretical modeling may aid in developing an optimized morphology to enhance device performance for OPVs.

  2. Peculiarity of two thermodynamically-stable morphologies and their impact on the efficiency of small molecule bulk heterojunction solar cells

    DOE PAGESBeta

    Herath, Nuradhika; Das, Sanjib; Keum, Jong K.; Zhu, Jiahua; Kumar, Rajeev; Ivanov, Ilia N.; Sumpter, Bobby G.; Browning, James F.; Xiao, Kai; Gu, Gong; et al

    2015-08-28

    Structural characteristics of the active layers in organic photovoltaic (OPV) devices play a critical role in charge generation, separation and transport. Here we report on morphology and structural control of p-DTS(FBTTh2)2:PC71BM films by means of thermal annealing and 1,8-diiodooctane (DIO) solvent additive processing, and correlate it to the device performance. By combining surface imaging with nanoscale depth-sensitive neutron reflectometry (NR) and X-ray diffraction, three-dimensional morphologies of the films are reconstituted with information extending length scales from nanometers to microns. DIO promotes the formation of a well-mixed donor-acceptor vertical phase morphology with a large population of small p-DTS(FBTTh2)2 nanocrystals arranged inmore » an elongated domain network of the film, thereby enhancing the device performance. In contrast, films without DIO exhibit three-sublayer vertical phase morphology with phase separation in agglomerated domains. Our findings are supported by thermodynamic description based on the Flory-Huggins theory with quantitative evaluation of pairwise interaction parameters that explain the morphological changes resulting from thermal and solvent treatments. Our study reveals that vertical phase morphology of small-molecule based OPVs is significantly different from polymer-based systems. Lastly, the significant enhancement of morphology and information obtained from theoretical modeling may aid in developing an optimized morphology to enhance device performance for OPVs.« less

  3. Peculiarity of Two Thermodynamically-Stable Morphologies and Their Impact on the Efficiency of Small Molecule Bulk Heterojunction Solar Cells

    PubMed Central

    Herath, Nuradhika; Das, Sanjib; Keum, Jong K.; Zhu, Jiahua; Kumar, Rajeev; Ivanov, Ilia N.; Sumpter, Bobby G.; Browning, James F.; Xiao, Kai; Gu, Gong; Joshi, Pooran; Smith, Sean; Lauter, Valeria

    2015-01-01

    Structural characteristics of the active layers in organic photovoltaic (OPV) devices play a critical role in charge generation, separation and transport. Here we report on morphology and structural control of p-DTS(FBTTh2)2:PC71BM films by means of thermal annealing and 1,8-diiodooctane (DIO) solvent additive processing, and correlate it to the device performance. By combining surface imaging with nanoscale depth-sensitive neutron reflectometry (NR) and X-ray diffraction, three-dimensional morphologies of the films are reconstituted with information extending length scales from nanometers to microns. DIO promotes the formation of a well-mixed donor-acceptor vertical phase morphology with a large population of small p-DTS(FBTTh2)2 nanocrystals arranged in an elongated domain network of the film, thereby enhancing the device performance. In contrast, films without DIO exhibit three-sublayer vertical phase morphology with phase separation in agglomerated domains. Our findings are supported by thermodynamic description based on the Flory-Huggins theory with quantitative evaluation of pairwise interaction parameters that explain the morphological changes resulting from thermal and solvent treatments. Our study reveals that vertical phase morphology of small-molecule based OPVs is significantly different from polymer-based systems. The significant enhancement of morphology and information obtained from theoretical modeling may aid in developing an optimized morphology to enhance device performance for OPVs. PMID:26315070

  4. Peculiarity of Two Thermodynamically-Stable Morphologies and Their Impact on the Efficiency of Small Molecule Bulk Heterojunction Solar Cells.

    PubMed

    Herath, Nuradhika; Das, Sanjib; Keum, Jong K; Zhu, Jiahua; Kumar, Rajeev; Ivanov, Ilia N; Sumpter, Bobby G; Browning, James F; Xiao, Kai; Gu, Gong; Joshi, Pooran; Smith, Sean; Lauter, Valeria

    2015-01-01

    Structural characteristics of the active layers in organic photovoltaic (OPV) devices play a critical role in charge generation, separation and transport. Here we report on morphology and structural control of p-DTS(FBTTh2)2:PC71BM films by means of thermal annealing and 1,8-diiodooctane (DIO) solvent additive processing, and correlate it to the device performance. By combining surface imaging with nanoscale depth-sensitive neutron reflectometry (NR) and X-ray diffraction, three-dimensional morphologies of the films are reconstituted with information extending length scales from nanometers to microns. DIO promotes the formation of a well-mixed donor-acceptor vertical phase morphology with a large population of small p-DTS(FBTTh2)2 nanocrystals arranged in an elongated domain network of the film, thereby enhancing the device performance. In contrast, films without DIO exhibit three-sublayer vertical phase morphology with phase separation in agglomerated domains. Our findings are supported by thermodynamic description based on the Flory-Huggins theory with quantitative evaluation of pairwise interaction parameters that explain the morphological changes resulting from thermal and solvent treatments. Our study reveals that vertical phase morphology of small-molecule based OPVs is significantly different from polymer-based systems. The significant enhancement of morphology and information obtained from theoretical modeling may aid in developing an optimized morphology to enhance device performance for OPVs. PMID:26315070

  5. Spheroidal and ellipsoidal harmonic expansions of the gravitational potential of small Solar System bodies. Case study: Comet 67P/Churyumov-Gerasimenko

    NASA Astrophysics Data System (ADS)

    Reimond, Stefan; Baur, Oliver

    2016-03-01

    Gravitational features are a fundamental source of information to learn more about the interior structure and composition of planets, moons, asteroids, and comets. Gravitational field modeling typically approximates the target body with a sphere, leading to a representation in spherical harmonics. However, small celestial bodies are often irregular in shape and hence poorly approximated by a sphere. A much better suited geometrical fit is achieved by a triaxial ellipsoid. This is also mirrored in the fact that the associated harmonic expansion (ellipsoidal harmonics) shows a significantly better convergence behavior as opposed to spherical harmonics. Unfortunately, complex mathematics and numerical problems (arithmetic overflow) so far severely limited the applicability of ellipsoidal harmonics. In this paper, we present a method that allows expanding ellipsoidal harmonics to a considerably higher degree compared to existing techniques. We apply this novel approach to model the gravitational field of comet 67P, the final target of the Rosetta mission. The comparison of results based on the ellipsoidal parameterization with those based on the spheroidal and spherical approximations reveals that the latter is clearly inferior; the spheroidal solution, on the other hand, is virtually just as accurate as the ellipsoidal one. Finally, in order to generalize our findings, we assess the gravitational field modeling performance for some 400 small bodies in the Solar System. From this investigation we generally conclude that the spheroidal representation is an attractive alternative to the complex ellipsoidal parameterization, on the one hand, and the inadequate spherical representation, on the other hand.

  6. New benzo[1,2-b:4,5-b']dithiophene-based small molecules containing alkoxyphenyl side chains for high efficiency solution-processed organic solar cells.

    PubMed

    Du, Zhengkun; Chen, Weichao; Wen, Shuguang; Qiao, Shanlin; Liu, Qian; Ouyang, Dan; Wang, Ning; Bao, Xichang; Yang, Renqiang

    2014-12-01

    A new acceptor-donor-acceptor (A-D-A) small molecule, namely, BDT-PO-DPP, based on the alkoxyphenyl (PO)-substituted benzo[1,2-b:4,5-b']dithiophene (BDT) derivative and the diketopyrrolopyrrole (DPP) unit was synthesized as an electron donor for solution-processed small-molecule organic solar cells (SMOSCs). BDT-PO-DPP exhibited good thermal stability, with a 5 % weight-lost temperature at 401 °C under a nitrogen atmosphere. BDT-PO-DPP exhibited a lower HOMO energy level of -5.25 eV and a weaker aggregation ability than alkoxy-substituted BDT-O-DPP. A bulk heterojunction SMOSC device based on BDT-PO-DPP and [6,6]-phenyl-C61 -butyric acid methyl ester was prepared, and it showed a power conversion efficiency up to 5.63% with a high open-circuit voltage of 0.83 V, a short circuit current density of 11.23 mA cm(-2) , and a fill factor of 60.37% by using 1,2-dichlorobenzene as the co-solvent after thermal annealing at 110 °C. The results indicate that the alkoxyphenyl-substituted BDT derivative is a promising electron-donor building block for constructing highly efficient solution-processed SMOSCs. PMID:25346491

  7. Raman Spectrometer for Surface Identification of Minerals and Organic Compounds on Silicate Planets and Small Solar-System Bodies

    NASA Technical Reports Server (NTRS)

    Haskin, Larry A.

    2000-01-01

    This summary is the final report of work on two-year grant. Our objectives for this project were (1) to demonstrate that Raman spectroscopy is an excellent method for determining mineralogy on the surface of the Moon, Mars, and other planetary bodies; (2) to construct a prototype of a small Raman spectrometer of the kind we suggest could be used on a lander or rover; and (3) to test the ability of that spectrometer to identify minerals and quantify mineral proportions in lunar materials and complex Martian analog materials, and to identify organic matter in planetary surface materials, all under roughly simulated field conditions. These goals have been met. The principal accomplishments of this PIDDP project have been the following: selection for flight; construction of a breadboard Raman probe; throughput confirmation of the breadboard Raman probe; selection of a laser; a breadboard spectrograph based on our PIDDP design; and overall result.

  8. Small-scale Magnetic Islands in the Solar Wind and Their Role in Particle Acceleration. II. Particle Energization inside Magnetically Confined Cavities

    NASA Astrophysics Data System (ADS)

    Khabarova, Olga V.; Zank, Gary P.; Li, Gang; Malandraki, Olga E.; le Roux, Jakobus A.; Webb, Gary M.

    2016-08-01

    We explore the role of heliospheric magnetic field configurations and conditions that favor the generation and confinement of small-scale magnetic islands associated with atypical energetic particle events (AEPEs) in the solar wind. Some AEPEs do not align with standard particle acceleration mechanisms, such as flare-related or simple diffusive shock acceleration processes related to interplanetary coronal mass ejections (ICMEs) and corotating interaction regions (CIRs). As we have shown recently, energetic particle flux enhancements may well originate locally and can be explained by particle acceleration in regions filled with small-scale magnetic islands with a typical width of ∼0.01 au or less, which is often observed near the heliospheric current sheet (HCS). The particle energization is a consequence of magnetic reconnection-related processes in islands experiencing either merging or contraction, observed, for example, in HCS ripples. Here we provide more observations that support the idea and the theory of particle energization produced by small-scale-flux-rope dynamics (Zank et al. and Le Roux et al.). If the particles are pre-accelerated to keV energies via classical mechanisms, they may be additionally accelerated up to 1–1.5 MeV inside magnetically confined cavities of various origins. The magnetic cavities, formed by current sheets, may occur at the interface of different streams such as CIRs and ICMEs or ICMEs and coronal hole flows. They may also form during the HCS interaction with interplanetary shocks (ISs) or CIRs/ICMEs. Particle acceleration inside magnetic cavities may explain puzzling AEPEs occurring far beyond ISs, within ICMEs, before approaching CIRs as well as between CIRs.

  9. Small-scale Magnetic Islands in the Solar Wind and Their Role in Particle Acceleration. II. Particle Energization inside Magnetically Confined Cavities

    NASA Astrophysics Data System (ADS)

    Khabarova, Olga V.; Zank, Gary P.; Li, Gang; Malandraki, Olga E.; le Roux, Jakobus A.; Webb, Gary M.

    2016-08-01

    We explore the role of heliospheric magnetic field configurations and conditions that favor the generation and confinement of small-scale magnetic islands associated with atypical energetic particle events (AEPEs) in the solar wind. Some AEPEs do not align with standard particle acceleration mechanisms, such as flare-related or simple diffusive shock acceleration processes related to interplanetary coronal mass ejections (ICMEs) and corotating interaction regions (CIRs). As we have shown recently, energetic particle flux enhancements may well originate locally and can be explained by particle acceleration in regions filled with small-scale magnetic islands with a typical width of ˜0.01 au or less, which is often observed near the heliospheric current sheet (HCS). The particle energization is a consequence of magnetic reconnection-related processes in islands experiencing either merging or contraction, observed, for example, in HCS ripples. Here we provide more observations that support the idea and the theory of particle energization produced by small-scale-flux-rope dynamics (Zank et al. and Le Roux et al.). If the particles are pre-accelerated to keV energies via classical mechanisms, they may be additionally accelerated up to 1–1.5 MeV inside magnetically confined cavities of various origins. The magnetic cavities, formed by current sheets, may occur at the interface of different streams such as CIRs and ICMEs or ICMEs and coronal hole flows. They may also form during the HCS interaction with interplanetary shocks (ISs) or CIRs/ICMEs. Particle acceleration inside magnetic cavities may explain puzzling AEPEs occurring far beyond ISs, within ICMEs, before approaching CIRs as well as between CIRs.

  10. Phase 1 of the First Small Power System Experiment (engineering Experiment No. 1). Volume 5: Supporting Analyses and Trade Studies. [development and testing of a solar thermal power plant

    NASA Technical Reports Server (NTRS)

    Holl, R. J.

    1979-01-01

    The development and design of a modular solar thermal power system for application in the 1 to 10 MWe range is described. The system is used in remote utility applications, small communities, rural areas, and for industrial uses. Thermal and stress analyses are performed on the collector subsystem, energy storage subsystem, energy transport subsystem, the power conversion subsystem, and the plant control subsystem.

  11. Solar electricity and solar fuels

    NASA Astrophysics Data System (ADS)

    Spiers, David J.

    1989-04-01

    The nature of solar radiation and its variation with location is described. The distribution of energy in the solar spectrum places immediate limits on the theoretical efficiency of conversion processes, since practical absorbers cannot convert all wavelengths received to useful energy. The principles of solar energy conversion methods are described. Absorption of solar energy can give rise to direct electrical generation, heating, or chemical change. Electrical generation from sunlight can be achieved by photovoltaic systems directly or by thermal systems which use solar heat to drive a heat engine and generator. The technology used and under research for promising ways of producing electricity or fuel from solar energy is described. Photovoltaic technology is established today for remote area, small power applications, and photovoltaic module sales alone are over 100 million dollars per year at present. The photovoltaic market has grown steadily since the mid-1970's, as prices have fallen continuously. Future energy options are briefly described. The merits of a sustainable energy economy, based on renewable energy resources, including solar energy, are emphasized, as this seems to provide the only hope of eliminating the problems caused by the build-up of atmospheric carbon dioxide, acid rain pollution and nuclear waste disposal. There is no doubt that clean fuels which were derived from solar energy and either did not involve carbon dioxide and used atmospheric carbon dioxide as the source dioxide as the source of carbon would be a worthy ideal. Methods described could one day achieve this.

  12. Reliable solar cookers

    SciTech Connect

    Magney, G.K.

    1992-12-31

    The author describes the activities of SERVE, a Christian relief and development agency, to introduce solar ovens to the Afghan refugees in Pakistan. It has provided 5,000 solar cookers since 1984. The experience has demonstrated the potential of the technology and the need for a durable and reliable product. Common complaints about the cookers are discussed and the ideal cooker is described.

  13. Effective D-A-D type chromophore of fumaronitrile-core and terminal alkylated bithiophene for solution-processed small molecule organic solar cells

    PubMed Central

    Nazim, M.; Ameen, Sadia; Seo, Hyung-Kee; Shin, Hyung Shik

    2015-01-01

    A new and novel organic π-conjugated chromophore (named as RCNR) based on fumaronitrile-core acceptor and terminal alkylated bithiophene was designed, synthesized and utilized as an electron-donor material for the solution-processed fabrication of bulk-heterojunction (BHJ) small molecule organic solar cells (SMOSCs). The synthesized organic chromophore exhibited a broad absorption peak near green region and strong emission peak due to the presence of strong electron-withdrawing nature of two nitrile (–CN) groups of fumaronitrile acceptor. The highest occupied molecular orbital (HOMO) energy level of –5.82 eV and the lowest unoccupied molecular orbital (LUMO) energy level of –3.54 eV were estimated for RCNR due to the strong electron-accepting tendency of –CN groups. The fabricated SMOSC devices with RCNR:PC60BM (1:3, w/w) active layer exhibited the reasonable power conversion efficiency (PCE) of ~2.69% with high short-circuit current density (JSC) of ~9.68 mA/cm2 and open circuit voltage (VOC) of ~0.79 V. PMID:26066557

  14. Utilizing alkoxyphenyl substituents for side-chain engineering of efficient benzo[1,2-b:4,5-b']dithiophene-based small molecule organic solar cells.

    PubMed

    Du, Zhengkun; Chen, Weichao; Qiu, Meng; Chen, Yanhua; Wang, Ning; Wang, Ting; Sun, Mingliang; Yu, Donghong; Yang, Renqiang

    2015-07-14

    A new two-dimensional (2D) conjugated small molecule, namely DCA3TBDTP, with an alkoxyphenyl substituted benzo[1,2-b:4,5-b']dithiophene (BDT) unit as the central core, octyl cyanoacetate as the end-capped groups and terthiophene as the π-linked bridge, was designed and synthesized for solution-processed organic solar cells (OSCs) as an electron donor material, in which an alkoxyphenyl group was introduced as a weak electron-donating side chain of the BDT moiety. The DCA3TBDTP molecule exhibited good solubility, a deep highest occupied molecular orbital (HOMO) level (-5.25 eV), an appropriate optical band-gap (1.82 eV) and a high decomposition temperature (362 °C). By applying the simple solution spin-coating fabrication process, the bulk heterojunction (BHJ) OSCs based on DCA3TBDTP and [6,6]-phenyl-C61-butyric acid methyl ester (PC61BM) exhibited a good power conversion efficiency (PCE) of 4.51% with a high open-circuit voltage (Voc) of 0.90 V when thermal annealing at only 70 °C. PMID:26077329

  15. Easy Access to NO2 -Containing Donor-Acceptor-Acceptor Electron Donors for High Efficiency Small-Molecule Organic Solar Cells.

    PubMed

    Ting, Hao-Chun; Yang, Ya-Ting; Chen, Chia-Hsun; Lee, Jiun-Haw; Chang, Jung-Hung; Wu, Chih-I; Chiu, Tien-Lung; Lin, Chi-Feng; Chung, Chin-Lung; Wong, Ken-Tsung

    2016-06-22

    Two donor-acceptor-acceptor (D-A-A)-type molecules incorporating nitrobenzoxadiazole (NBO) as the A-A block and ditolylamine as the D block bridged through a phenylene (PNBO) and a thiophene (TNBO) spacer were synthesized in a one-step coupling reaction. Their electronic, photophysical, and thermal properties; crystallographic analysis; and theoretical calculations were studied to establish a clear structure-property relationship. The results indicate that the quinoidal character of the thiophene bridge strongly governs the structural features and crystal packings (herringbone vs. brickwork) and thus the physical properties of the compounds. PNBO and TNBO were utilized as electron donors combined with C70 as the electron acceptor in the active layer of vacuum-processed bulk heterojunction small-molecule organic solar cells (SMOSCs). The power conversion efficiency of both PNBO- and TNBO-based OSCs exceeded 5 %. The ease of accessibility of PNBO and TNBO demonstrates the potential for simple and economical synthesis of electron donors in vacuum-processed SMOSCs. PMID:27213296

  16. Influence of the indium tin oxide/organic interface on open-circuit voltage, recombination, and cell degradation in organic small-molecule solar cells

    NASA Astrophysics Data System (ADS)

    Schäfer, Stefan; Petersen, Andreas; Wagner, Thomas A.; Kniprath, Rolf; Lingenfelser, Dominic; Zen, Achmad; Kirchartz, Thomas; Zimmermann, Birger; Würfel, Uli; Feng, Xianjin; Mayer, Thomas

    2011-04-01

    In this paper we investigate the performance and stability of small-molecule organic solar cells with respect to the indium tin oxide (ITO)/organic interface. Different zinc-phthalocyanine (ZnPc)/fullerene (C60) cell architectures with and without ITO O2-plasma treatment are compared and tested with respect to their degradation behavior under illumination in inert atmosphere. Photoelectron spectroscopy (UPS and XPS) shows that the O2-plasma treatment increases the ITO work function from 4.3 eV up to 5.6 eV. We find that both the increased ITO work function as well as the introduction of an electron blocking layer between ITO and the mixed donor/acceptor layer increases the open-circuit voltage Voc by more than 200 mV. For both cases our continuum approach device simulation quantitatively relates the increase of Voc to a reduced contact recombination and thus a reduced dark current. For cells built on ozone treated ITO we find a fast cell degradation caused by the UV part of the AM 1.5 spectrum. We identify the degradation, which manifests itself in a decrease of Voc of up to 25%, as a partial reversion of the plasma induced ITO work function increase. Additionally, we demonstrate that the degradation can be reduced by structural changes in the cell architecture, leading to improved cell stability. We present a comprehensive study of the recombination at the ITO/organic interface and its influence on the open-circuit voltage and the cell stability.

  17. High open-circuit voltage small-molecule p-DTS(FBTTh 2 )2.ICBA bulk heterojunction solar cells – morphology, excited-state dynamics, and photovoltaic performance

    DOE PAGESBeta

    Ko Kyaw, Aung Ko; Gehrig, Dominik; Zhang, Jie; Huang, Ye; Bazan, Guillermo C.; Laquai, Frédéric; Nguyen, Thuc -Quyen

    2014-11-27

    The photovoltaic performance of bulk heterojunction solar cells using the solution-processable small molecule donor 7,7'-(4,4-bis(2-ethylhexyl)-4H-silolo[3,2-b:4,5-b']dithiophene-2,6-diyl)bis(6-fluoro-4-(5'-hexyl-[2,2'-bithiophene]-5-yl)benzo[c][1,2,5]thiadiazole) (p-DTS(FBTTh2)2 in combination with indene-C60 bis-adduct (ICBA) as an acceptor is systematically optimized by altering the processing conditions. A high open-circuit voltage of 1 V, more than 0.2 V higher than that of a p-DTS(FBTTh2)2:PC70BM blend, is achieved. However, the power conversion efficiency remains around 5% and thus is lower than ~8% previously reported for p-DTS(FBTTh2)2:PC70BM. Transient absorption (TA) pump–probe spectroscopy over a wide spectral (Vis-NIR) and dynamic (fs to μs) range in combination with multivariate curve resolution analysis of the TA data reveals thatmore » generation of free charges is more efficient in the blend with PC70BM as an acceptor. In contrast, blends with ICBA create more coulombically bound interfacial charge transfer (CT) states, which recombine on the sub-nanosecond timescale by geminate recombination. Furthermore, the ns to μs charge carrier dynamics in p-DTS(FBTTh2)2:ICBA blends are only weakly intensity dependent implying a significant contribution of recombination from long-lived CT states and trapped charges, while those in p-DTS(FBTTh2)2:PC70BM decay via an intensity-dependent recombination mechanism indicating that spatially separated (free) charge carriers are observed, which can be extracted as photocurrent from the device.« less

  18. Future Directions in Solar Physics

    NASA Technical Reports Server (NTRS)

    Rabin, Douglas

    2010-01-01

    I will discuss scientific opportunities for space-based solar physics instruments in the coming decade and their synergy with major new ground-based telescopes. l will also discuss ( pow small satellites may complement larger solar physics missions.

  19. Solar Neutrinos

    DOE R&D Accomplishments Database

    Davis, R. Jr.; Harmer, D. S.

    1964-12-01

    The prospect of studying the solar energy generation process directly by observing the solar neutrino radiation has been discussed for many years. The main difficulty with this approach is that the sun emits predominantly low energy neutrinos, and detectors for observing low fluxes of low energy neutrinos have not been developed. However, experimental techniques have been developed for observing neutrinos, and one can foresee that in the near future these techniques will be improved sufficiently in sensitivity to observe solar neutrinos. At the present several experiments are being designed and hopefully will be operating in the next year or so. We will discuss an experiment based upon a neutrino capture reaction that is the inverse of the electron-capture radioactive decay of argon-37. The method depends upon exposing a large volume of a chlorine compound, removing the radioactive argon-37 and observing the characteristic decay in a small low-level counter.

  20. 77 FR 11533 - Agency Information Collection Activities: Comment Request

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-27

    ....S. Agency Information Collection Activities: Comment Request AGENCY: Export-Import Bank of the U.S... Business Administration is the U.S. Government Agency (created by the Small Business Act, as amended) that... Small Business Act (15 U.S.C. 636(a)(14) to determine eligibility of applicant for SBA assistance...

  1. Small Scale Industries.

    ERIC Educational Resources Information Center

    Rural Development Detwork Bulletin, 1977

    1977-01-01

    Innovative programs for the promotion of small-scale enterprise are being conducted by a variety of organizations, including universities, government agencies, international research institutes, and voluntary assistance agencies. Their activities encompass basic extension services, management of cooperatives, community action programs, and…

  2. 48 CFR 5119.1004 - Participating agencies.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 48 Federal Acquisition Regulations System 7 2011-10-01 2011-10-01 false Participating agencies. 5119.1004 Section 5119.1004 Federal Acquisition Regulations System DEPARTMENT OF THE ARMY ACQUISITION REGULATIONS SMALL BUSINESS AND SMALL DISADVANTAGED BUSINESS CONCERNS Small Business...

  3. 48 CFR 5119.1004 - Participating agencies.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 48 Federal Acquisition Regulations System 7 2010-10-01 2010-10-01 false Participating agencies. 5119.1004 Section 5119.1004 Federal Acquisition Regulations System DEPARTMENT OF THE ARMY ACQUISITION REGULATIONS SMALL BUSINESS AND SMALL DISADVANTAGED BUSINESS CONCERNS Small Business...

  4. Solar astronomy

    NASA Technical Reports Server (NTRS)

    Rosner, Robert; Noyes, Robert; Antiochos, Spiro K.; Canfield, Richard C.; Chupp, Edward L.; Deming, Drake; Doschek, George A.; Dulk, George A.; Foukal, Peter V.; Gilliland, Ronald L.

    1991-01-01

    An overview is given of modern solar physics. Topics covered include the solar interior, the solar surface, the solar atmosphere, the Large Earth-based Solar Telescope (LEST), the Orbiting Solar Laboratory, the High Energy Solar Physics mission, the Space Exploration Initiative, solar-terrestrial physics, and adaptive optics. Policy and related programmatic recommendations are given for university research and education, facilitating solar research, and integrated support for solar research.

  5. Non-symmetrical profiles of the C IV 1548A and 1550A lines for small dynamic events and their interpretation in terms of resonant scattering in solar active region

    NASA Astrophysics Data System (ADS)

    Gontikakis, Costis; Vial, Jean-Claude

    2016-07-01

    We present observations of small areas in solar active regions recorded with the SUMER/SOHO spectrograph where the C IV 1548A and 1550A lines have spectral profiles of different shapes, although they are recorded simultaneously and at the same location. This asymmetry may be explained by resonant scattering associated with relative velocities of the emitting plasmas. We present detailed artificial spectral profiles that may explain the observations. The profiles have been computed using several physical parameters such as the plasma temperature and electron density and/or the incident radiation on the emitting volumes. We conclude that the study of asymmetries in the C IV 1548A, 1550A lines, and also in different doublets, can be a valuable diagnostic tool for deriving the physical conditions in solar/stellar plasmas, especially where the radiation processes (such as flare-emission) are enhanced at the vicinity of the observed structures.

  6. Implementing Solar Technologies at Airports

    SciTech Connect

    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.

  7. Workshop on Solar Activity, Solar Wind, Terrestrial Effects, and Solar Acceleration

    NASA Technical Reports Server (NTRS)

    1992-01-01

    A summary of the proceedings from the workshop are presented. The areas covered were solar activity, solar wind, terrestrial effects, and solar acceleration. Specific topics addressed include: (1) solar cycle manifestations, both large and small scale, as well as long-term and short-term changes, including transients such as flares; (2) sources of solar wind, as identified by interplanetary observations including coronal mass ejections (CME's) or x-ray bright points, and the theory for and evolution of large-scale and small-scale structures; (3) magnetosphere responses, as observed by spacecraft, to variable solar wind and transient energetic particle emissions; and (4) origin and propagation of solar cosmic rays as related to solar activity and terrestrial effects, and solar wind coronal-hole relationships and dynamics.

  8. CNO abundances and hydrodynamic studies of the Nova outburst. V - 1.00-solar-mass models with small mass envelopes

    NASA Technical Reports Server (NTRS)

    Starrfield, S.; Truran, J. W.; Sparks, W. M.

    1978-01-01

    The paper reports on an investigation into the consequences of thermonuclear runaways in accreted hydrogen envelopes of 100 millionths of a solar mass on 1-solar-mass white dwarfs. These evolutionary sequences predict that from 10 to 50 millionths of a solar mass will be ejected with speeds from 300 to 3800 km/s (kinetic energies of 10 to the 44th-45th power ergs). Absolute visual magnitudes as high as -8.1 are attained, well within the observed range for fast novae. In addition, the shapes of the theoretical light curves are more reminiscent of an observed fast-nova light curve than those in earlier studies. The ejected material is strongly enhanced in the products of incomplete CNO burning; the most abundant of the ejected nuclei is C-13, followed by N-14 and C-12. The differences from previous studies are attributable to the lower peak temperatures reached in these sequences. These models also produce a large overabundance of Li-7, suggesting that novae may represent significant contributors to the galactic enrichment of this nucleus.

  9. Solar Water Heating with Low-Cost Plastic Systems (Brochure)

    SciTech Connect

    Not Available

    2012-01-01

    Newly developed solar water heating technology can help Federal agencies cost effectively meet the EISA requirements for solar water heating in new construction and major renovations. This document provides design considerations, application, economics, and maintenance information and resources.

  10. Orbit Mechanics about Small Asteroids

    NASA Technical Reports Server (NTRS)

    Scheeres, D. J.

    2007-01-01

    Space missions to small solar system bodies must deal with multiple perturbations acting on the spacecraft. These include strong perturbations from the gravity field and solar tide, but for small bodies the most important perturbations may arise from solar radiation pressure (SRP) acting on the spacecraft. Previous research has generally investigated the effect of the gravity field, solar tide, and SRP acting on a spacecraft trajectory about an asteroid in isolation and has not considered their joint effect. In this paper a more general theoretical discussion of the joint effects of these forces is given.

  11. Solar Electricity

    NASA Technical Reports Server (NTRS)

    1988-01-01

    ARCO Solar manufactures PV Systems tailored to a broad variety of applications. PV arrays are routinely used at remote communications installations to operate large microwave repeaters, TV and radio repeaters rural telephone, and small telemetry systems that monitor environmental conditions. Also used to power agricultural water pumping systems, to provide electricity for isolated villages and medical clinics, for corrosion protection for pipelines and bridges, to power railroad signals, air/sea navigational aids, and for many types of military systems. ARCO is now moving into large scale generation for utilities.

  12. Very high efficiency solar cells

    NASA Astrophysics Data System (ADS)

    Barnett, Allen; Kirkpatrick, Douglas; Honsberg, Christiana

    2006-08-01

    The Defense Advanced Research Projects Agency has initiated the Very High Efficiency Solar Cell (VHESC) program to address the critical need of the soldier for power in the field. Very High Efficiency Solar Cells for portable applications that operate at greater than 55 percent efficiency in the laboratory and 50 percent in production are being developed. We are integrating the optical design with the solar cell design, and have entered previously unoccupied design space that leads to a new architecture paradigm. An integrated team effort is now underway that requires us to invent, develop and transfer to production these new solar cells. Our approach is driven by proven quantitative models for the solar cell design, the optical design and the integration of these designs. We start with a very high performance crystalline silicon solar cell platform. Examples will be presented. Initial solar cell device results are shown for devices fabricated in geometries designed for this VHESC Program.

  13. Accounting for Agency

    ERIC Educational Resources Information Center

    Valentine, Kylie

    2011-01-01

    Children are increasingly described as agents and agency is important to arguments for children's rights and participation. Yet agency is rarely defined or theorised in childhood studies. This article reviews common uses and meanings of agency and argues that critical, social conceptualisations have yet to be extensively taken up in childhood…

  14. 48 CFR 719.271 - Agency program direction and operation.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 48 Federal Acquisition Regulations System 5 2011-10-01 2011-10-01 false Agency program direction and operation. 719.271 Section 719.271 Federal Acquisition Regulations System AGENCY FOR INTERNATIONAL DEVELOPMENT SOCIOECONOMIC PROGRAMS SMALL BUSINESS PROGRAMS Policies 719.271 Agency program direction...

  15. 48 CFR 719.271 - Agency program direction and operation.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 48 Federal Acquisition Regulations System 5 2010-10-01 2010-10-01 false Agency program direction and operation. 719.271 Section 719.271 Federal Acquisition Regulations System AGENCY FOR INTERNATIONAL DEVELOPMENT SOCIOECONOMIC PROGRAMS SMALL BUSINESS PROGRAMS Policies 719.271 Agency program direction...

  16. 40 CFR 36.645 - Federal agency or agency.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 1 2010-07-01 2010-07-01 false Federal agency or agency. 36.645 Section 36.645 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY GRANTS AND OTHER FEDERAL... Federal agency or agency. Federal agency or agency means any United States executive department,...

  17. Omnidirectional and broadband optical absorption enhancement in small molecule organic solar cells by a patterned MoO3/Ag/MoO3 transparent anode

    NASA Astrophysics Data System (ADS)

    Tian, Ximin; Hao, Yuying; Zhang, Ye; Cui, Yanxia; Ji, Ting; Wang, Hua; Wei, Bin; Huang, Wei

    2015-03-01

    We designed and calculated a novel organic solar cell (OSC) with MoO3/Ag/MoO3 (MAM) grating as transparent anode and the patterned copper phthalocyanine (CuPc)/fullerence (C60) as active layer. The numerical results indicate that a broadband, omnidirectional light absorption enhancement is realized by utilizing such a one-dimensional (1D) grating with core-shell structure. The total absorption efficiency of the active layer over the wavelength range from 400 to 900 nm is enhanced by 178.88%, 19.44% and 99.16% relative to the equivalent planar cell considering the weight of air-mass 1.5 global (AM 1.5G) solar spectrum at normally incident transverse magnetic (TM), transverse electric (TE) and TM/TE hybrid polarized light, respectively. The improved light trapping is attributed to the multiple modes hybridization of propagating surface plasmon polaritons (SPPs), localized surface plasmons (LSPs) and the strong coupling of SPP waves at TM polarization along with the Floquet modes at TE polarization. Furthermore, the proposed optimized architecture also exhibits an expected short-circuit current density (Jsc) with the value of 11.11 mA/cm2 in theory, which is increased by 116.6% compared with that of the planar control device.

  18. 77 FR 2539 - Meetings of the Small Communities Advisory Subcommittee and the Local Government Advisory Committee

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-01-18

    ... From the Federal Register Online via the Government Publishing Office ENVIRONMENTAL PROTECTION AGENCY Meetings of the Small Communities Advisory Subcommittee and the Local Government Advisory Committee AGENCY: Environmental Protection Agency. ACTION: Notice. SUMMARY: The Small Communities...

  19. Phase 1 of the First Small Power System Experiment (engineering Experiment No. 1). Volume 3: Experimental System Descriptions. [development and testing of a solar thermal power plant

    NASA Technical Reports Server (NTRS)

    Holl, R. J.

    1979-01-01

    The design and development of a modular solar thermal power system for application in the 1 to 10 MWe range is described. The system consists of five subsystems: the collector, power conversion, energy transport, energy storage, and the plant control subsystem. The collector subsystem consists of concentrator, receiver, and tower assemblies. The energy transport subsystem uses a mixture of salts with a low melting temperature to transport thermal energy. A steam generator drives a steam Rankine cycle turbine which drives an electrical generator to produce electricity. Thermal and stress analysis tests are performed on each subsystem in order to determine the operational reliability, the minimum risk of failure, and the maintenance and repair characteristics.

  20. Microstructure of amorphous-silicon-based solar cell materials by small-angle x-ray scattering. Annual technical report, April 6, 1995--April 5, 1996

    SciTech Connect

    Williamson, D.L.

    1996-08-01

    The objective of this project is to provide detailed microstructural information on the amorphous silicon based thin film materials under development for improved multijunction solar cells. Correlation of microstructure with opto-electrical properties and device performance is an integral part of the research. During this second phase of our three-year program we have obtained information on the microstructure of materials relevant to the Low-, Mid-, and High-bandgap Teams and the results are appropriately divided into these three types of material as presented below. The experimental methods, data analysis, and interpretation procedures are the same as those described in detail in the phase-one report and in the review paper published last year.

  1. Solar Atmosphere Simulation - AGU Dec. 9, 2013

    NASA Video Gallery

    This movie shows a numerical simulation of a small area of the solar atmosphere at ~10,000K. Numerical models bridge the gap between IRIS observations and the physical mechanisms driving solar even...

  2. Solar Cookers.

    ERIC Educational Resources Information Center

    King, Richard C.

    1981-01-01

    Describes the use of solar cookers in the science classroom. Includes instructions for construction of a solar cooker, an explanation of how solar cookers work, and a number of suggested activities. (DS)

  3. Solar Air Sampler

    NASA Technical Reports Server (NTRS)

    1981-01-01

    Nation's first solar-cell-powered air monitoring station was installed at Liberty State Park, New Jersey. Jointly sponsored by state agencies and the Department of Energy, system includes display which describes its operation to park visitors. Unit samples air every sixth day for a period of 24 hours. Air is forced through a glass filter, then is removed each week for examination by the New Jersey Bureau of Air Pollution. During the day, solar cells provide total power for the sampling equipment. Excess energy is stored in a bank of lead-acid batteries for use when needed.

  4. Quantifying charge transfer energies at donor-acceptor interfaces in small-molecule solar cells with constrained DFTB and spectroscopic methods.

    PubMed

    Scholz, Reinhard; Luschtinetz, Regina; Seifert, Gotthard; Jägeler-Hoheisel, Till; Körner, Christian; Leo, Karl; Rapacioli, Mathias

    2013-11-27

    Charge transfer states around the donor-acceptor interface in an organic solar cell determine the device performance in terms of the open circuit voltage. In the present work, we propose a computational scheme based on constrained density functional tight binding theory (c-DFTB) to assess the energy of the lowest charge transfer (CT) state in such systems. A comparison of the c-DFTB scheme with Hartree-Fock based configuration interaction of singles (CIS) and with time-dependent density functional theory (TD-DFT) using the hybrid functional B3LYP reveals that CIS and c-DFTB reproduce the correct Coulomb asymptotics between cationic donor and anionic acceptor configurations, whereas TD-DFT gives a qualitatively wrong excitation energy. Together with an embedding scheme accounting for the polarizable medium, this c-DFTB scheme is applied to several donor-acceptor combinations used in molecular solar cells. The external quantum efficiency of photovoltaic cells based on zinc phthalocyanine-C60 blends reveals a CT band remaining much narrower than the density of states of acceptor HOMO and donor LUMO, an observation which can be interpreted in a natural way in terms of Marcus transfer theory. A detailed comparison with c-DFTB calculations reveals an energy difference of 0.32 eV between calculated and observed absorption from the electronic ground state into the CT state. In a blend of a functionalized thiophene and C60, the photoluminescence spectra differ significantly from neat films, allowing again an assignment to CT states. The proposed computational scheme reproduces the observed trends of the observed open circuit voltages in photovoltaic devices relying on several donor-acceptor blends, finding an offset of 1.16 eV on average. This value is similar as in polymer-fullerene photovoltaic systems where it amounts to about 0.9 eV, indicating that the photophysics of CT states in molecular donor-acceptor blends and in polymer-fullerene blends are governed by the

  5. Quantifying charge transfer energies at donor-acceptor interfaces in small-molecule solar cells with constrained DFTB and spectroscopic methods

    NASA Astrophysics Data System (ADS)

    Scholz, Reinhard; Luschtinetz, Regina; Seifert, Gotthard; Jägeler-Hoheisel, Till; Körner, Christian; Leo, Karl; Rapacioli, Mathias

    2013-11-01

    Charge transfer states around the donor-acceptor interface in an organic solar cell determine the device performance in terms of the open circuit voltage. In the present work, we propose a computational scheme based on constrained density functional tight binding theory (c-DFTB) to assess the energy of the lowest charge transfer (CT) state in such systems. A comparison of the c-DFTB scheme with Hartree-Fock based configuration interaction of singles (CIS) and with time-dependent density functional theory (TD-DFT) using the hybrid functional B3LYP reveals that CIS and c-DFTB reproduce the correct Coulomb asymptotics between cationic donor and anionic acceptor configurations, whereas TD-DFT gives a qualitatively wrong excitation energy. Together with an embedding scheme accounting for the polarizable medium, this c-DFTB scheme is applied to several donor-acceptor combinations used in molecular solar cells. The external quantum efficiency of photovoltaic cells based on zinc phthalocyanine-C60 blends reveals a CT band remaining much narrower than the density of states of acceptor HOMO and donor LUMO, an observation which can be interpreted in a natural way in terms of Marcus transfer theory. A detailed comparison with c-DFTB calculations reveals an energy difference of 0.32 eV between calculated and observed absorption from the electronic ground state into the CT state. In a blend of a functionalized thiophene and C60, the photoluminescence spectra differ significantly from neat films, allowing again an assignment to CT states. The proposed computational scheme reproduces the observed trends of the observed open circuit voltages in photovoltaic devices relying on several donor-acceptor blends, finding an offset of 1.16 eV on average. This value is similar as in polymer-fullerene photovoltaic systems where it amounts to about 0.9 eV, indicating that the photophysics of CT states in molecular donor-acceptor blends and in polymer-fullerene blends are governed by the same

  6. 77 FR 30227 - Small Business Size Regulations, Small Business Innovation Research (SBIR) Program and Small...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-05-22

    ... (SBIR) Program and Small Business Technology Transfer (STTR) Program AGENCY: U.S. Small Business... (SBIR) and Small Business Technology Transfer (STTR) Programs. The proposed rule would implement... ownership, control and affiliation for participants in the SBIR and STTR Programs. This...

  7. 77 FR 13329 - Information Collection; Small Business Size Representation

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-06

    ... implement the Small Business Administration (SBA) Final Rule (71 FR 66434), Small Business Size Regulations... Long-Term Contracts; 8(a) Business Development/Small Disadvantaged Business; Business Status...; Small Business Size Representation AGENCIES: Department of Defense (DOD), General...

  8. 76 FR 68439 - Meeting of the Small Communities Advisory Subcommittee

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-04

    ... AGENCY Meeting of the Small Communities Advisory Subcommittee AGENCY: Environmental Protection Agency. ACTION: Notice. SUMMARY: The Small Communities Advisory Subcommittee will meet on Thursday, December 1... environmental issues affecting small communities. This is an open meeting and all interested persons are...

  9. Performance verification of an air solar collector

    NASA Technical Reports Server (NTRS)

    Miller, D. C.; Romaker, R. F.

    1979-01-01

    Procedures and results of battery of qualification tests performed by independent certification agency on commercial solar collector are presented in report. Reported results were used as basis in judging collector suitable for field installation in residential and commerical buildings.

  10. Solar collector manufacturing activity, 1988

    NASA Astrophysics Data System (ADS)

    1989-11-01

    This report was prepared by the Energy Information Administration, the independent statistical and analytical agency within the U.S. Department of Energy in cooperation with the Office of Conservation and Renewable Energy. The report presents data on producer shipments and end uses obtained from manufacturers and importers of solar thermal collectors and photovoltaic modules. It provides annual data necessary for the Department of Energy to execute its responsibility to: (1) monitor activities and trends in the solar collector manufacturing industry, (2) prepare the national energy strategy, and (3) provide information on the size and status of the industry to interested groups such as the U.S. Congress, government agencies, the Solar Energy Research institute, solar energy specialists, manufacturers, and the general public.

  11. Performance status of a small robot-mounted or hand-held, solar-blind, standoff chemical, biological, and explosives (CBE) sensor

    NASA Astrophysics Data System (ADS)

    Hug, W. F.; Reid, R. D.; Bhartia, R.; Lane, A. L.

    2009-05-01

    Photon Systems and JPL are continuing development of a new technology robot-mounted or hand-held sensor for reagentless, short-range, standoff detection and identification of trace levels CBE materials on surfaces. This deep ultraviolet CBE sensor is the result of ongoing Army STTR and DTRA programs. The evolving 6 lb, 15W, lantern-size sensor can discriminate CBE from background clutter materials using a combination of deep UV excited resonance Raman (RR) and laser induced native fluorescence (LINF) emissions resulting from excitation by a new technology deep UV laser. Standoff excitation of suspicious packages, vehicles, persons, and other objects that may contain hazardous materials is accomplished using wavelengths below 250nm where RR and LINF emissions occupy distinctly different wavelength regions. This enables simultaneous detection of RR and LINF emissions with no spectral overlap or interference of LINF over RR or RR over LINF. The new eye-safe targeted ultraviolet chemical, biological, and explosives (TUCBE) sensor can detect and identify less than 1 μg/cm2 of explosives or 104 bacterial spores at 10 meters standoff, or 10 ng/cm2 of explosives or 102 bacterial spores/cm2 at 1 meter standoff. Detection and identification requires less than 1 ms and has a sample rate up to 20 Hz. Lower concentrations of contamination can be detected and identified as closer ranges and higher concentrations at longer ranges. The sensor is solar blind and can be operated in full daylight conditions as a result of excitation and detection in the deep UV and the use of a gated detection system.

  12. Packaging a Successful NASA Mission to Reach a Large Audience with a Small Budget. Earth's Dynamic Space: Solar-Terrestrial Physics and NASA's Polar Mission

    NASA Technical Reports Server (NTRS)

    Fox, Nicola J.; Goldberg, Richard; Barnes, Robin J.; Sigwarth, John B.; Beisser, Kerri B.; Moore, Thomas E.; Hoffman, Robert A.; Russell, Christopher T.; Scudder, Jack D.; Spann, James F.

    2004-01-01

    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. Team members also created visualizations using Polar data to complement the NASA stock footage. Scientists donated their time to create and review scripts 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.

  13. 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

    NASA Astrophysics Data System (ADS)

    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.

  14. A celestial gamma-ray foreground due to the albedo of small solar system bodies and a remote probe of the interstellar cosmic ray spectrum

    SciTech Connect

    Moskalenko, Igor V.; Porter, Troy A.; Digel, Seth W.; Michelson, Peter F.; Ormes, Jonathan F.

    2007-12-17

    We calculate the {gamma}-ray albedo flux from cosmic-ray (CR) interactions with the solid rock and ice in Main Belt asteroids and Kuiper Belt objects (KBOs) using the Moon as a template. We show that the {gamma}-ray albedo for the Main Belt and Kuiper Belt strongly depends on the small-body mass spectrum of each system and may be detectable by the forthcoming Gamma Ray Large Area Space Telescope (GLAST). The orbits of the Main Belt asteroids and KBOs are distributed near the ecliptic, which passes through the Galactic center and high Galactic latitudes. If detected, the {gamma}-ray emission by the Main Belt and Kuiper Belt has to be taken into account when analyzing weak {gamma}-ray sources close to the ecliptic, especially near the Galactic center and for signals at high Galactic latitudes, such as the extragalactic {gamma}-ray emission. Additionally, it can be used to probe the spectrum of CR nuclei at close-to-interstellar conditions, and the mass spectrum of small bodies in the Main Belt and Kuiper Belt. The asteroid albedo spectrum also exhibits a 511 keV line due to secondary positrons annihilating in the rock. This may be an important and previously unrecognized celestial foreground for the INTErnational Gamma-Ray Astrophysics Laboratory (INTEGRAL) observations of the Galactic 511 keV line emission including the direction of the Galactic center.

  15. Agency, communion and entitlement.

    PubMed

    Żemojtel-Piotrowska, Magdalena A; Piotrowski, Jarosław P; Clinton, Amanda

    2016-06-01

    In this study, the relationship between agency, communion, and the active, passive, and revenge forms of entitlement is examined. Results indicate that active entitlement was positively related to agency, negatively to communion (Study 1), and unrelated to unmitigated agency and communion (Study 2). Passive entitlement was positively related to communion (in regular and unmitigated forms) and negatively related to agency (in both forms). Revenge entitlement was positively related to agency (unmitigated and regular), and negatively related to both regular and unmitigated communal orientations. Detected relationships were independent from self-esteem (Study 1). The findings are discussed in relation to distinctions between narcissistic and healthy entitlement, and within the context of the three-dimensional model of entitlement. PMID:25594535

  16. Approaches and selection to space debris mitigation for small satellite

    NASA Astrophysics Data System (ADS)

    Zhang, X.; Zhang, B.; Zheng, Y.; Meng, B.; Xu, X.; Liu, Y.; Wu, Z.; Hao, Y.; Dong, Y.

    Aiming at space debris mitigation for small satellite after the end of mission, several approaches are analyzed and compared, and implementations are suggested in this paper. In recent years more and more small satellites have been developed and launched into orbit. Most of them run on Low Earth Orbit (LEO) with height less than 2000km. On the one hand, the small satellites increase the density of space debris and the risk of collision; on the other hand, some of them have orbit lifetime over 25 years if only depending natural attenuation beyond the guideline of Inter-agency Space Debris Coordination Committee (IADC). In this paper several approaches are analyzed and compared for space debris mitigation after the end of mission, including the utilizations of air drag, solar radiation pressure, rocket propulsion, and others. The cost will be required for small satellite to mitigate space debris. For lower orbit small satellites and their constellation, the functions and performances perhaps are degraded. For higher orbit satellites, lifetime of spacecraft always is more than 25 years. Then some supererogatory equipments should be appended to shorten orbit lifetime, such as air chamber, sail, even thruster, usually they are not necessary for small satellites. Based on the analysis of effect and cost for these approaches, implementations are suggested for small satellite with different functions (whether or not provide capability of orbit control) and different mass: 50kg, 100kg, 150kg and 300kg. This research is supported by China National Space Administration (CNSA).

  17. Solar explosion

    NASA Astrophysics Data System (ADS)

    Baccei, B. C.

    1981-04-01

    The Solar Energy Research Institute (SERI) and the Department of Energy (DOE) Passive Solar Manufactured Buildings and Solar Home Builders Programs are developing much needed cost and performance data on solar buildings produced by large-volume home builders. These programs also serve as a model on how government can work effectively with industry.

  18. Solar Energy.

    ERIC Educational Resources Information Center

    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…

  19. Solar Geometry

    Atmospheric Science Data Center

    2014-09-25

    Solar Noon (GMT time) The time when the sun is due south in the ... and sunset.   Daylight average of hourly cosine solar zenith angles (dimensionless) The average cosine of the angle ... overhead during daylight hours.   Cosine solar zenith angle at mid-time between sunrise and solar noon ...

  20. Solar energy

    NASA Technical Reports Server (NTRS)

    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.

  1. Short review on solar energy systems

    NASA Astrophysics Data System (ADS)

    Herez, Amal; Ramadan, Mohamad; Abdulhay, Bakri; Khaled, Mahmoud

    2016-07-01

    Solar energy can be utilized mainly in heat generation and electricity production. International energy agency (IEA) shows, in a comparative study on the world energy consumption that in 2050 solar arrays installation will provide about 45% of world energy demand. Solar energy is one of the most important renewable energy source which plays a great role in providing energy solutions. As known there is wide variety of types of collectors and applications of solar energy. This paper aimed to make a short review on solar energy systems, according to types of collectors and applications used.

  2. 48 CFR 719.271-2 - The USAID Office of Small and Disadvantaged Business Utilization (SDB).

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... Regulations System AGENCY FOR INTERNATIONAL DEVELOPMENT SOCIOECONOMIC PROGRAMS SMALL BUSINESS PROGRAMS Policies 719.271-2 The USAID Office of Small and Disadvantaged Business Utilization (SDB). (a) SDB is responsible for administering, implementing, and coordinating the Agency's small business (including...

  3. 48 CFR 719.271-2 - The USAID Office of Small and Disadvantaged Business Utilization (SDB).

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... Regulations System AGENCY FOR INTERNATIONAL DEVELOPMENT SOCIOECONOMIC PROGRAMS SMALL BUSINESS PROGRAMS Policies 719.271-2 The USAID Office of Small and Disadvantaged Business Utilization (SDB). (a) SDB is responsible for administering, implementing, and coordinating the Agency's small business (including...

  4. 48 CFR 719.271-2 - The USAID Office of Small and Disadvantaged Business Utilization (SDB).

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... Regulations System AGENCY FOR INTERNATIONAL DEVELOPMENT SOCIOECONOMIC PROGRAMS SMALL BUSINESS PROGRAMS Policies 719.271-2 The USAID Office of Small and Disadvantaged Business Utilization (SDB). (a) SDB is responsible for administering, implementing, and coordinating the Agency's small business (including...

  5. Mars solar conjunction prediction modeling

    NASA Astrophysics Data System (ADS)

    Srivastava, Vineet K.; Kumar, Jai; Kulshrestha, Shivali; Kushvah, Badam Singh

    2016-01-01

    During the Mars solar conjunction, telecommunication and tracking between the spacecraft and the Earth degrades significantly. The radio signal degradation depends on the angular separation between the Sun, Earth and probe (SEP), the signal frequency band and the solar activity. All radiometric tracking data types display increased noise and signatures for smaller SEP angles. Due to scintillation, telemetry frame errors increase significantly when solar elongation becomes small enough. This degradation in telemetry data return starts at solar elongation angles of around 5° at S-band, around 2° at X-band and about 1° at Ka-band. This paper presents a mathematical model for predicting Mars superior solar conjunction for any Mars orbiting spacecraft. The described model is simulated for the Mars Orbiter Mission which experienced Mars solar conjunction during May-July 2015. Such a model may be useful to flight projects and design engineers in the planning of Mars solar conjunction operational scenarios.

  6. 20 CFR 439.645 - Federal agency or agency.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 20 Employees' Benefits 2 2010-04-01 2010-04-01 false Federal agency or agency. 439.645 Section 439.645 Employees' Benefits SOCIAL SECURITY ADMINISTRATION GOVERNMENTWIDE REQUIREMENTS FOR DRUG-FREE WORKPLACE (FINANCIAL ASSISTANCE) Definitions § 439.645 Federal agency or agency. Federal agency or...

  7. The Solar Dynamos

    NASA Astrophysics Data System (ADS)

    Cattaneo, F.

    2000-05-01

    Magnetic activity on the Sun presents us with an interesting dichotomy. On large spatial and temporal scales the solar magnetic field displays a remarkable degree of organization. The 11 years cadence of the solar cycle, Hales' polarity law, and the systematic drift of the regions of emergence of active regions towards the equator throughout the solar cycle are all indicative of a powerful organizing process. On small spatial and temporal scales, the Solar magnetic field appears random and chaotic. It is interesting that recent advances in dynamo theory provide us with a unified approach to solar magnetic activity whereby both large and small scales emerge naturally as dynamo processes associated with rotationally constrained and unconstrained scales of motions in the convection zone (or directly below it). According to this view all coherent scales of motions produce magnetic structures of comparable coherence length. Those that are further endowed with lack of reflectional symmetry by virtue of being rotationally constrained are further associated with inverse cascades that can generate magnetic structures on larger scales still. The picture that emerges is one in which dynamo action proceeds on different time scales all over the convection zone. But only in very special regions, like for instance the solar tachocline, is the magnetic field organized on large scales. This idea provides a natural explanation for the origin of active regions, ephemeral regions, and intra--network fields.

  8. Solar Cycle 23: Variation of the Solar Corona in the Ultraviolet from Solar Minimum to Solar Maximum

    NASA Astrophysics Data System (ADS)

    Miralles, M. P.; Panasyuk, A. V.; Strachan, L.; Gardner, L. D.; Suleiman, R.; Cranmer, S. R.; Kohl, J. L.

    2001-06-01

    UVCS/SOHO measurements of H I Ly-alpha and O VI (103.2 nm and 103.7 nm) intensities in the solar corona have been made from solar Cycle 23's minimum in 1996 to its current maximum. At solar minimum, the corona consisted of large coronal holes at the poles and quiescent streamers at the equator. During the approach to solar maximum, equatorial coronal holes and high latitude streamers became more conspicuous. Recently, coronal holes at higher latitudes have reappeared, allowing a comparison to be made of O VI intensities and line widths of coronal holes at different latitudes. We also characterize the variation of coronal hole properties with height, and location over the solar cycle. This work is supported by NASA under Grant NAG5-10093 to the Smithsonian Astrophysical Observatory, by the Italian Space Agency and by PRODEX (Swiss contribution)

  9. The Politics of Science and Technology: Nuclear and Solar Alternatives.

    ERIC Educational Resources Information Center

    Etzkowitz, Henry

    Historical data reveal that U.S. government policy and military and corporate interests have been instrumental in the development of nuclear energy and the underdevelopment of solar energy. It was not until 1972 that solar energy was funded by the Energy Research and Development Agency (ERDA) and in 1974 solar energy received $12.2 million as…

  10. The Earliest Solar System Weathering: Mega-Solar-Wind Effects in Early Solar System Silicates

    NASA Astrophysics Data System (ADS)

    Wetteland, C. J.; Sickafus, K. E.; McSween, H. Y.; Taylor, L. A.

    2015-11-01

    Early solar materials may be exposed to large fluxes of high-energy protons during stellar evolution. Experimental results indicate that small fragments of minerals may be melted, and low Z atoms can be transmuted to exotic isotopes.

  11. An Improved Instrument for Angular Scattering Measurements of Candidate Planetary Surface Regolith Materials at Extremely Small Phase Angles: Relevance to the Outer Solar System

    NASA Astrophysics Data System (ADS)

    Nelson, R. M.; Boryta, M. D.; Hapke, B. W.; Manatt, K.; Kroner, D. O.; Smythe, W. D.

    2014-12-01

    The reflection variation and the polarization change with phase angle of radiation scattered from particulate materials has been studied for a century in efforts to understand the nature of clouds, aerosols, planetary ring systems and planetary regolith materials. The increase in reflectance as phase angle decreases, the 'Opposition Effect', has been well documented in astronomical observations and laboratory studies. Variations in linear polarization near small phase angles have also been well studied (e.g. Shkuratov et al.,2002, Rosenbush et al. 2015). While the phenomena have been well documented, a generally accepted physical explanation is still lacking despite many excellent theoretical modeling efforts. We have undertaken a reductionist approach in deconstructing the process. We have fabricated a goniometer which permits us to present samples with discrete wavelengths of monochromatic light that is linearly polarized in and perpendicular to the scattering plane. We also can illuminate our samples with both right handed and left handed circular polarization senses. Silicon Avalanche Photodiodes record the reflected radiation from the sample after it has passed through linear and circular polarizing analyzers(Kroner et al.). This reductionist approach permits us to measure the reflectance and polarization phase curves and the change in linear and circular polarization ratio (LPR and CPR) with phase angle between 0.056 and 17 degrees. LPR and CPR are found to be important indicators of the amount of multiple scattering in the medium (Hapke, 1990, Nelson et al, 1998, 2000;Hapke, 2012). This approach provides a way to distinguish between suggested models and to gain greater insight into the process of the scattering of electromagnetic radiation in a variety of media. This work was supported by NASA's Cassini Science Program Hapke, B. (1990), Icarus, 88, 407-217. Hapke, B. (2012). Theory of Reflectance and Emittance Spectroscopy, Cambridge U. Press, New York

  12. Solar Hot Water Heater

    NASA Technical Reports Server (NTRS)

    1978-01-01

    The solar panels pictured below, mounted on a Moscow, Idaho home, are part of a domestic hot water heating system capable of providing up to 100 percent of home or small business hot water needs. Produced by Lennox Industries Inc., Marshalltown, Iowa, the panels are commercial versions of a collector co-developed by NASA. In an effort to conserve energy, NASA has installed solar collectors at a number of its own facilities and is conducting research to develop the most efficient systems. Lewis Research Center teamed with Honeywell Inc., Minneapolis, Minnesota to develop the flat plate collector shown. Key to the collector's efficiency is black chrome coating on the plate developed for use on spacecraft solar cells, the coating prevents sun heat from "reradiating," or escaping outward. The design proved the most effective heat absorber among 23 different types of collectors evaluated in a Lewis test program. The Lennox solar domestic hot water heating system has three main components: the array of collectors, a "solar module" (blue unit pictured) and a conventional water heater. A fluid-ethylene glycol and water-is circulated through the collectors to absorb solar heat. The fluid is then piped to a double-walled jacket around a water tank within the solar module.

  13. 76 FR 60475 - Issuance of a Loan Guarantee to Tonopah Solar Energy, LLC, for the Crescent Dunes Solar Energy...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-29

    ... Dunes Solar Energy Project (the Project). The Project is a proposed 110- megawatt solar power generating facility based on concentrating solar power technology, using mirrors and a central receiver, on..., Nevada (75 FR 70917, November 19, 2010) (FEIS), prepared by BLM with DOE as a cooperating agency....

  14. 75 FR 41231 - Notice of Intent To Prepare an Environmental Impact Statement for the Proposed Abengoa Solar Inc...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-15

    ... Lathrop Wells Solar Facility project would consist of a concentrated solar power facility including a... proposal may include up to 20 MW of photovoltaic solar power. The proposed project would be located on... Solar Inc., Lathrop Wells Solar Facility, Amargosa Valley, Nye County, NV AGENCY: Bureau of...

  15. International Solar Terrestrial Physics (ISTP) program

    NASA Technical Reports Server (NTRS)

    Sanford, R.; Muhonen, D.; Sizemore, K. O.

    1991-01-01

    The International Solar Terrestrial Physics (ISTP) Program is a large, multi-national program involving three space agencies and up to eight spacecraft. NASA, together with the Institute of Space and Astronomical Science (ISAS) and the European Space Agency (ESA), has agreed in principle to coordinate their efforts in investigating the Sun and the Earth. Each agency is planning to construct and operate different spacecraft as part of this cooperative venture: Geotail provided by ISAS, the Solar Heliospheric Observatory (SOHO) and Cluster (four spacecraft) contributed by ESA, and Wind and Polar by NASA. A general description of the program is presented.

  16. Technology for small spacecraft

    NASA Technical Reports Server (NTRS)

    1994-01-01

    This report gives the results of a study by the National Research Council's Panel on Small Spacecraft Technology that reviewed NASA's technology development program for small spacecraft and assessed technology within the U.S. government and industry that is applicable to small spacecraft. The panel found that there is a considerable body of advanced technology currently available for application by NASA and the small spacecraft industry that could provide substantial improvement in capability and cost over those technologies used for current NASA small spacecraft. These technologies are the result of developments by commercial companies, Department of Defense agencies, and to a lesser degree NASA. The panel also found that additional technologies are being developed by these same entities that could provide additional substantial improvement if development is successfully completed. Recommendations for future technology development efforts by NASA across a broad technological spectrum are made.

  17. High Efficiency Dye-sensitized Solar Cells Constructed with Composites of TiO2 and the Hot-bubbling Synthesized Ultra-Small SnO2 Nanocrystals

    NASA Astrophysics Data System (ADS)

    Mao, Xiaoli; Zhou, Ru; Zhang, Shouwei; Ding, Liping; Wan, Lei; Qin, Shengxian; Chen, Zhesheng; Xu, Jinzhang; Miao, Shiding

    2016-01-01

    An efficient photo-anode for the dye-sensitized solar cells (DSSCs) should have features of high loading of dye molecules, favorable band alignments and good efficiency in electron transport. Herein, the 3.4 nm-sized SnO2 nanocrystals (NCs) of high crystallinity, synthesized via the hot-bubbling method, were incorporated with the commercial TiO2 (P25) particles to fabricate the photo-anodes. The optimal percentage of the doped SnO2 NCs was found at ~7.5% (SnO2/TiO2, w/w), and the fabricated DSSC delivers a power conversion efficiency up to 6.7%, which is 1.52 times of the P25 based DSSCs. The ultra-small SnO2 NCs offer three benefits, (1) the incorporation of SnO2 NCs enlarges surface areas of the photo-anode films, and higher dye-loading amounts were achieved; (2) the high charge mobility provided by SnO2 was confirmed to accelerate the electron transport, and the photo-electron recombination was suppressed by the highly-crystallized NCs; (3) the conduction band minimum (CBM) of the SnO2 NCs was uplifted due to the quantum size effects, and this was found to alleviate the decrement in the open-circuit voltage. This work highlights great contributions of the SnO2 NCs to the improvement of the photovoltaic performances in the DSSCs.

  18. Solar Lentigo

    MedlinePlus

    ... hyperpigmented) lesion caused by natural or artificial ultraviolet (UV) light. Solar lentigines may be single or multiple. This ... simplex) because it is caused by exposure to UV light. Solar lentigines are benign, but they do indicate ...

  19. Solar Cooking

    Atmospheric Science Data Center

    2014-09-25

    ... (kWh/m2/day) Amount of electromagnetic energy (solar radiation) incident on the surface of the earth. Also referred to as total or global solar radiation.   Midday insolation (kWh/m2/day) Average ...

  20. Solar Equipment

    NASA Technical Reports Server (NTRS)

    1983-01-01

    A medical refrigeration and a water pump both powered by solar cells that convert sunlight directly into electricity are among the line of solar powered equipment manufactured by IUS (Independent Utility Systems) for use in areas where conventional power is not available. IUS benefited from NASA technology incorporated in the solar panel design and from assistance provided by Kerr Industrial Applications Center.

  1. Federal Law on Consumer Deception: An Agency by Agency Analysis.

    ERIC Educational Resources Information Center

    Zweibel, George J.

    A comprehensive analysis of statutes and regulations on consumer deception administered by thirty government agencies is provided in this report. Each agency's chapter includes a brief description of the agency, and a detailed listing of all deceptive trade practices prohibited by that agency's enabling legislation, regulations, or other sources…

  2. 10 CFR 607.645 - Federal agency or agency.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 4 2010-01-01 2010-01-01 false Federal agency or agency. 607.645 Section 607.645 Energy DEPARTMENT OF ENERGY (CONTINUED) ASSISTANCE REGULATIONS GOVERNMENTWIDE REQUIREMENTS FOR DRUG-FREE WORKPLACE (FINANCIAL ASSISTANCE) Definitions § 607.645 Federal agency or agency. Department of Energy means the...

  3. 76 FR 57769 - Advisory Committee on Small and Emerging Companies

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-16

    ... COMMISSION Advisory Committee on Small and Emerging Companies AGENCY: Securities and Exchange Commission... Commission intends to establish the Securities and Exchange Commission Advisory Committee on Small and... Chief, Office of ] Small Business Policy, Securities and Exchange Commission, 100 F Street,...

  4. 78 FR 59991 - Advisory Committee on Small and Emerging Companies

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-09-30

    ... COMMISSION Advisory Committee on Small and Emerging Companies AGENCY: Securities and Exchange Commission... on Small and Emerging Companies. FOR FURTHER INFORMATION CONTACT: Johanna Losert, Special Counsel, Office of Small Business Policy, Securities and Exchange Commission, 100 F Street, NE., Washington...

  5. 76 FR 52377 - National Small Business Development Center Advisory Board

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-22

    ... ADMINISTRATION National Small Business Development Center Advisory Board AGENCY: U.S. Small Business... Business Development Center (SBDC) Advisory Board at the ASBDC Conference. DATES: Wednesday, September 7... to the SBA Administrator and Associate Administrator for Small Business Development Centers....

  6. 78 FR 70847 - Small Business Size Standards; Manufacturing; Correction

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-27

    ... RIN 3245-AG47 Small Business Size Standards; Manufacturing; Correction AGENCY: U.S. Small Business... small business size standards. In FR Doc. 2012-19973 appearing on page 49991 of the August 20,...

  7. 48 CFR 970.1907 - The Small Business Subcontracting Program.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... AGENCY SUPPLEMENTARY REGULATIONS DOE MANAGEMENT AND OPERATING CONTRACTS Small Business Programs 970.1907 The Small Business Subcontracting Program. ... 48 Federal Acquisition Regulations System 5 2014-10-01 2014-10-01 false The Small...

  8. 48 CFR 970.1907 - The Small Business Subcontracting Program.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... AGENCY SUPPLEMENTARY REGULATIONS DOE MANAGEMENT AND OPERATING CONTRACTS Small Business Programs 970.1907 The Small Business Subcontracting Program. ... 48 Federal Acquisition Regulations System 5 2013-10-01 2013-10-01 false The Small...

  9. 48 CFR 970.1907 - The Small Business Subcontracting Program.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... AGENCY SUPPLEMENTARY REGULATIONS DOE MANAGEMENT AND OPERATING CONTRACTS Small Business Programs 970.1907 The Small Business Subcontracting Program. ... 48 Federal Acquisition Regulations System 5 2012-10-01 2012-10-01 false The Small...

  10. 77 FR 63298 - Accelerated Payments to Small Business Subcontractors

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-16

    ... Defense Acquisition Regulations System Accelerated Payments to Small Business Subcontractors AGENCY... Small Business Subcontractors (July 11, 2012), DoD has taken steps to accelerate Federal payments to prime contractors, so that prime contractors can expedite payments to their small...

  11. Solar dish/engine systems

    SciTech Connect

    Not Available

    1998-04-01

    Solar dish/engine systems convert the energy from the sun into electricity at a very high efficiency. Using a mirror array formed into the shape of a dish, the solar dish focuses the sun`s rays onto a receiver. The receiver transmits the energy to an engine that generates electric power. Because of the high concentration ratios achievable with parabolic dishes and the small size of the receiver, solar dishes are efficient at collecting solar energy at very high temperatures. Tests of prototype systems and components at locations throughout the US have demonstrated net solar to electric conversion efficiencies as high as 30%. This is significantly higher than any other solar technology.

  12. 77 FR 25131 - Turning Point Solar LLC: Notice of Finding of No Significant Impact

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-27

    ... Rural Utilities Service Turning Point Solar LLC: Notice of Finding of No Significant Impact AGENCY... Assessment (EA) associated with a solar generation project. The EA was prepared in accordance with the... associated with a potential loan or loan guarantee to Turning Point Solar LLC (Turning Point Solar) for...

  13. European Space Agency announces comet landing site

    NASA Astrophysics Data System (ADS)

    Wendel, JoAnna

    2014-09-01

    Scientists believe that comets hold clues to the solar system's origins, and soon they will be one step closer to unlocking these secrets. Last week, the European Space Agency announced that the spacecraft Rosetta will deploy its lander, Philae, to land on the "head" of the comet 67/P Churyumov-Gerasimenko at candidate site J. Project scientists have been racing to choose an ideal landing site since Rosetta arrived at the comet on 6 August. This event will mark the first landing mission on a comet.

  14. Holographic Solar Photon Thrusters

    NASA Technical Reports Server (NTRS)

    Johnson, Les; Matloff, Greg

    2006-01-01

    A document discusses a proposal to incorporate holographic optical elements into solar photon thrusters (SPTs). First suggested in 1990, SPTs would be systems of multiple reflective, emissive, and absorptive surfaces (solar sails) that would be attached to spacecraft orbiting the Earth to derive small propulsive forces from radiation pressures. An SPT according to the proposal would include, among other things, a main sail. One side of the sail would be highly emissive and would normally face away from the Earth. The other side would be reflective and would be covered by white-light holographic images that would alternately become reflective, transmissive, and absorptive with small changes in the viewing angle. When the spacecraft was at a favorable orbital position, the main sail would be oriented to reflect sunlight in a direction to maximize the solar thrust; when not in a favorable position, the main sail would be oriented to present a substantially absorptive/emissive aspect to minimize the solar drag. By turning the main sail slightly to alternate between the reflective and absorptive/ emissive extremes, one could achieve nearly a doubling or halving of the radiational momentum transfer and, hence, of the solar thrust.

  15. Soiling of building envelope surfaces and its effect on solar reflectance. Part I: Analysis of roofing product databases

    SciTech Connect

    Sleiman, Mohamad; Ban-Weiss, George; Gilbert, Haley E.; François, David; Berdahl, Paul; Kirchstetter, Thomas W.; Destaillats, Hugo; Levinson, Ronnen

    2011-12-01

    The use of highly reflective “cool” roofing materials can decrease demand for air conditioning, mitigate the urban heat island effect, and potentially slow global warming. However, initially high roof solar reflectance can be degraded by natural soiling and weathering processes. We evaluated solar reflectance losses after three years of natural exposure reported in two separate databases: the Rated Products Directory of the US Cool Roof Rating Council (CRRC) and information reported by manufacturers to the US Environmental Protection Agency (EPA)’s ENERGY STAR® rating program. Many product ratings were culled because they were duplicative (within a database) or not measured. A second, site-resolved version of the CRRC dataset was created by transcribing from paper records the site-specific measurements of aged solar reflectance in Florida, Arizona and Ohio. Products with high initial solar reflectance tended to lose reflectance, while those with very low initial solar reflectance tended to become more reflective as they aged. Within the site-resolved CRRC database, absolute solar reflectance losses for samples of medium-to-high initial solar reflectance were 2 - 3 times greater in Florida (hot and humid) than in Arizona (hot and dry); losses in Ohio (temperate but polluted) were intermediate. Disaggregating results by product type, factory-applied coating, field-applied coating, metal, modified bitumen, shingle, singleply membrane and tile, revealed that absolute solar reflectance losses were largest for fieldapplied coating, modified bitumen and single-ply membrane products, and smallest for factoryapplied coating and metal products.The 2008 Title 24 provisional aged solar reflectance formula overpredicts the measured aged solar reflectance of 0% to 30% of each product type in the culled public CRRC database. The rate of overprediction was greatest for field-applied coating and single-ply membrane products and least for factory-applied coating, shingle, and

  16. Soiling of building envelope surfaces and its effect on solar reflectance. Part I: Analysis of roofing product databases

    DOE PAGESBeta

    Sleiman, Mohamad; Ban-Weiss, George; Gilbert, Haley E.; François, David; Berdahl, Paul; Kirchstetter, Thomas W.; Destaillats, Hugo; Levinson, Ronnen

    2011-12-01

    The use of highly reflective “cool” roofing materials can decrease demand for air conditioning, mitigate the urban heat island effect, and potentially slow global warming. However, initially high roof solar reflectance can be degraded by natural soiling and weathering processes. We evaluated solar reflectance losses after three years of natural exposure reported in two separate databases: the Rated Products Directory of the US Cool Roof Rating Council (CRRC) and information reported by manufacturers to the US Environmental Protection Agency (EPA)’s ENERGY STAR® rating program. Many product ratings were culled because they were duplicative (within a database) or not measured. Amore » second, site-resolved version of the CRRC dataset was created by transcribing from paper records the site-specific measurements of aged solar reflectance in Florida, Arizona and Ohio. Products with high initial solar reflectance tended to lose reflectance, while those with very low initial solar reflectance tended to become more reflective as they aged. Within the site-resolved CRRC database, absolute solar reflectance losses for samples of medium-to-high initial solar reflectance were 2 - 3 times greater in Florida (hot and humid) than in Arizona (hot and dry); losses in Ohio (temperate but polluted) were intermediate. Disaggregating results by product type, factory-applied coating, field-applied coating, metal, modified bitumen, shingle, singleply membrane and tile, revealed that absolute solar reflectance losses were largest for fieldapplied coating, modified bitumen and single-ply membrane products, and smallest for factoryapplied coating and metal products.The 2008 Title 24 provisional aged solar reflectance formula overpredicts the measured aged solar reflectance of 0% to 30% of each product type in the culled public CRRC database. The rate of overprediction was greatest for field-applied coating and single-ply membrane products and least for factory-applied coating

  17. Solar Meter

    NASA Technical Reports Server (NTRS)

    1978-01-01

    The instrument pictured is an inexpensive solar meter which is finding wide acceptance among architects, engineers and others engaged in construction of solar energy facilities. It detects the amount of solar energy available at a building site, information necessary to design the most efficient type of solar system for a particular location. Incorporating technology developed by NASA's Lewis Research Center, the device is based upon the solar cell, which provides power for spacecraft by converting the sun's energy to electricity. The meter is produced by Dodge Products, Inc., Houston, Texas, a company formed to bring the technology to the commercial marketplace.

  18. Solar flair.

    PubMed Central

    Manuel, John S

    2003-01-01

    Design innovations and government-sponsored financial incentives are making solar energy increasingly attractive to homeowners and institutional customers such as school districts. In particular, the passive solar design concept of daylighting is gaining favor among educators due to evidence of improved performance by students working in daylit classrooms. Electricity-generating photovoltaic systems are also becoming more popular, especially in states such as California that have high electric rates and frequent power shortages. To help spread the word about solar power, the U.S. Department of Energy staged its first-ever Solar Decathlon in October 2002. This event featured solar-savvy homes designed by 14 college teams. PMID:12573926

  19. Solar flair.

    PubMed

    Manuel, John S

    2003-02-01

    Design innovations and government-sponsored financial incentives are making solar energy increasingly attractive to homeowners and institutional customers such as school districts. In particular, the passive solar design concept of daylighting is gaining favor among educators due to evidence of improved performance by students working in daylit classrooms. Electricity-generating photovoltaic systems are also becoming more popular, especially in states such as California that have high electric rates and frequent power shortages. To help spread the word about solar power, the U.S. Department of Energy staged its first-ever Solar Decathlon in October 2002. This event featured solar-savvy homes designed by 14 college teams. PMID:12573926

  20. Solar Access to Public Capital (SAPC) Mock Securitization Project

    SciTech Connect

    Mendelsohn, Michael; Lowder, Travis; Rottman, Mary; Borod, Ronald; Gabig, Nathan; Henne, Stephen; Caplin, Conrad; Notte, Quentin

    2015-12-21

    In late 2012, the National Renewable Energy Laboratory (NREL) initiated the Solar Access to Public Capital (SAPC) working group. Backed by a three-year funding facility from the U.S. Department of Energy (DOE), NREL set out to organize the solar, legal, banking, capital markets, engineering, and other relevant stakeholder communities in order to open lower-cost debt investment for solar asset deployment. SAPC engaged its members to standardize contracts, develop best practices, and comprehend how the rating agencies perceive solar project portfolios as an investment asset class. Rating agencies opine on the future creditworthiness of debt obligations. Issuers often seek investment-grade ratings from the rating agencies in order to satisfy the desires of their investors. Therefore, for the solar industry to access larger pools of capital at a favorable cost, it is critical to increase market participants' understanding of solar risk parameters. The process provided valuable information to address rating agency perceptions of risk that, without such information, could require costly credit enhancement or higher yields to attract institutional investors. Two different securities were developed--one for a hypothetical residential solar portfolio and one for a hypothetical commercial solar portfolio. Five rating agencies (Standard and Poor's, Moody's, KBRA, Fitch, and DBRS) participated and provided extensive feedback, some through conversations that extended several months. The findings represented in this report are a composite summary of that feedback and do not indicate any specific feedback from any single rating agency.

  1. Solar Energy: Solar System Economics.

    ERIC Educational Resources Information Center

    Knapp, Henry H., III

    This module on solar system economics is one of six in a series intended for use as supplements to currently available materials on solar energy and energy conservation. Together with the recommended texts and references (sources are identified), these modules provide an effective introduction to energy conservation and solar energy technologies.…

  2. Review of activities and plans for solar energy in Federal buildings

    NASA Astrophysics Data System (ADS)

    1980-10-01

    Federal Buildings program and plans regarding the use of solar energy are reported. Recommendations concerning the solar Federal Buildings Program's plan are given, specifically an analysis of agencies' Ten Year Buildings construction, leasing and retrofit plans to provide visibility for and detailed knowledge of Federal agencies planning regarding solar and other renewable resources. Statistical information regarding planned solar projects, and recommendations concerning the SFBP plans are presented.

  3. Solar Filament Extraction and Characterizing

    NASA Astrophysics Data System (ADS)

    Yuan, Yuan; Shih, F. Y.; Jing, J.; Wang, H.

    2010-05-01

    This paper presents a new method to extract and characterize solar filaments from H-alpha full-disk images produced by Big Bear Solar Observatory. A cascading Hough Transform method is designed to identify solar disk center location and radius. Solar disks are segmented from the background, and unbalanced illumination on the surface of solar disks is removed using polynomial surface fitting. And then a localized adaptive thresholding is employed to extract solar filament candidates. After the removal of small solar filament candidates, the remaining larger candidates are used as the seeds of region growing. The procedure of region growing not only connects broken filaments but also generate complete shape for each filament. Mathematical morphology thinning is adopted to produce the skeleton of each filament, and graph theory is used to prune branches and barbs to get the main skeleton. The length and the location of the main skeleton is characterized. The proposed method can help scientists and researches study the evolution of solar filament, for instance, to detect solar filament eruption. The presented method has already been used by Space Weather Research Lab of New Jersey Institute of Technology (http://swrl.njit.edu) to generate the solar filament online catalog using H-alpha full-disk images of Global H-alpha Network (http://swrl.njit.edu/ghn_web/).

  4. Youth Media and Agency

    ERIC Educational Resources Information Center

    Hauge, Chelsey

    2014-01-01

    This article addresses how capacity is conceived of and understood in youth media/civic education programming, and how beliefs about agency, development, relationality and youth manifests in the discourses, programmes, and practices of organizations operating youth media programmes. Through attention to a youth media and development programme in…

  5. Metacognition of Agency

    ERIC Educational Resources Information Center

    Metcalfe, Janet; Greene, Matthew Jason

    2007-01-01

    The feeling that we are agents, intentionally making things happen by our own actions, is foundational to our understanding of ourselves as humans. People's metacognitions of agency were investigated in 4 experiments. Participants played a game in which they tried to touch downward scrolling Xs and avoid touching Os. Variables that affected…

  6. Other Federal Agencies

    ERIC Educational Resources Information Center

    Design and Environment, 1971

    1971-01-01

    Briefly reviews the man-environment research sponsored by these eight government agencies: Departments of Agriculture, Commerce, Defense, Interior, Justice, the Office of Economic Opportunity, the National Aeronautics and Space Administration, and the National Science Foundation. The Man-Environment Research survey report was the source of…

  7. Strengthening Career Human Agency

    ERIC Educational Resources Information Center

    Chen, Charles P.

    2006-01-01

    Rooted in A. Bandura's (1982, 2001b) social cognitive theory, the notion of human agency has received considerable attention in vocational and career psychology for the last 2 decades, especially with the recent emergence of social constructivist thinking in the field. This article continues in the same direction. In reviewing the notion of human…

  8. Metacognition of agency.

    PubMed

    Metcalfe, Janet; Greene, Matthew Jason

    2007-05-01

    The feeling that we are agents, intentionally making things happen by our own actions, is foundational to our understanding of ourselves as humans. People's metacognitions of agency were investigated in 4 experiments. Participants played a game in which they tried to touch downward scrolling Xs and avoid touching Os. Variables that affected accuracy included speed of the scroll, density of the targets, and feedback. Of central interest were variables directed not only at accuracy but also at people's control: the turbulence of the cursor and how close the cursor had to come to the target for a hit (i.e., "magic"). After each trial, people made judgments of agency or judgments of performance. People were selectively sensitive to the variables to which they should be responsive in agency monitoring--whether the cursor moved in close synchrony to their movements and whether targets disappeared by magic. People knew, separably from their objective or judged performance, when they were in control and when they were not. These results indicate that people can sensitively monitor their own agency. PMID:17500645

  9. Solar cell activation system

    SciTech Connect

    Apelian, L.

    1983-07-05

    A system for activating solar cells involves the use of phosphorescent paint, the light from which is amplified by a thin magnifying lens and used to activate solar cells. In a typical system, a member painted with phosphorescent paint is mounted adjacent a thin magnifying lens which focuses the light on a predetermined array of sensitive cells such as selenium, cadmium or silicon, mounted on a plastic board. A one-sided mirror is mounted adjacent the cells to reflect the light back onto said cells for purposes of further intensification. The cells may be coupled to rechargeable batteries or used to directly power a small radio or watch.

  10. Normativity, agency, and life.

    PubMed

    Barham, James

    2012-03-01

    There is an immense philosophical literature dealing with the notions of normativity and agency, as well as a sizeable and rapidly growing scientific literature on the topic of autonomous agents. However, there has been very little cross-fertilization between these two literatures. As a result, the philosophical literature tends to assume a somewhat outdated mechanistic image of living things, resulting in a quasi-dualistic picture in which only human beings, or the higher animals, can be normative agents properly speaking. From this perspective, the project of 'naturalizing normativity' becomes almost a contradiction in terms. At the same time, the scientific literature tends to misuse 'normativity,' 'agency,' and related terms, assuming that it is meaningful to ascribe these concepts to 'autonomous agents' conceived of as physical systems whose behavior is to be explained in terms of ordinary physical law. From this perspective, the true depth of the difficulty involved in understanding what makes living systems distinctive qua physical systems becomes occluded. In this essay, I begin the attempt to remedy this situation. After some preliminary discussion of terminology and situating of my project within the contemporary philosophical landscape, I make a distinction between two different aspects of the project of naturalizing normativity: (1) the 'Scope Problem,' which consists in saying how widely in nature our concept of normative agency may properly be applied; and (2) the 'Ground Problem,' which consists in rationalizing the phenomenon of normative agency in terms of the rest of our knowledge of nature. Then, in the remainder of this paper, I argue that the Scope Problem ought to be resolved in favor of attributing normative agency, in the proper sense of those words, to living things as such. The Ground Problem will be discussed in a companion paper at a later time. PMID:22326078

  11. Miniature personal UV solar dosimeter

    NASA Technical Reports Server (NTRS)

    Adams, R. R.; Macconochie, I. O.; Poole, B. D., Jr.

    1981-01-01

    Small light-powered meter measures accumulated radiation in ultraviolet or other selected regions. Practical advantages are device's low cost, small size, accuracy, and adaptability to specific wave-band measurements. Medical applications include detection of skin cancer, vitamin D production, and jaundice. Dosimeter also measures sunlight for solar energy designs, agriculture and meteorology, and monitors stability of materials and environmental and occupational lighting.

  12. High Efficiency Dye-sensitized Solar Cells Constructed with Composites of TiO2 and the Hot-bubbling Synthesized Ultra-Small SnO2 Nanocrystals.

    PubMed

    Mao, Xiaoli; Zhou, Ru; Zhang, Shouwei; Ding, Liping; Wan, Lei; Qin, Shengxian; Chen, Zhesheng; Xu, Jinzhang; Miao, Shiding

    2016-01-01

    An efficient photo-anode for the dye-sensitized solar cells (DSSCs) should have features of high loading of dye molecules, favorable band alignments and good efficiency in electron transport. Herein, the 3.4 nm-sized SnO2 nanocrystals (NCs) of high crystallinity, synthesized via the hot-bubbling method, were incorporated with the commercial TiO2 (P25) particles to fabricate the photo-anodes. The optimal percentage of the doped SnO2 NCs was found at ~7.5% (SnO2/TiO2, w/w), and the fabricated DSSC delivers a power conversion efficiency up to 6.7%, which is 1.52 times of the P25 based DSSCs. The ultra-small SnO2 NCs offer three benefits, (1) the incorporation of SnO2 NCs enlarges surface areas of the photo-anode films, and higher dye-loading amounts were achieved; (2) the high charge mobility provided by SnO2 was confirmed to accelerate the electron transport, and the photo-electron recombination was suppressed by the highly-crystallized NCs; (3) the conduction band minimum (CBM) of the SnO2 NCs was uplifted due to the quantum size effects, and this was found to alleviate the decrement in the open-circuit voltage. This work highlights great contributions of the SnO2 NCs to the improvement of the photovoltaic performances in the DSSCs. PMID:26758941

  13. High Efficiency Dye-sensitized Solar Cells Constructed with Composites of TiO2 and the Hot-bubbling Synthesized Ultra-Small SnO2 Nanocrystals

    PubMed Central

    Mao, Xiaoli; Zhou, Ru; Zhang, Shouwei; Ding, Liping; Wan, Lei; Qin, Shengxian; Chen, Zhesheng; Xu, Jinzhang; Miao, Shiding

    2016-01-01

    An efficient photo-anode for the dye-sensitized solar cells (DSSCs) should have features of high loading of dye molecules, favorable band alignments and good efficiency in electron transport. Herein, the 3.4 nm-sized SnO2 nanocrystals (NCs) of high crystallinity, synthesized via the hot-bubbling method, were incorporated with the commercial TiO2 (P25) particles to fabricate the photo-anodes. The optimal percentage of the doped SnO2 NCs was found at ~7.5% (SnO2/TiO2, w/w), and the fabricated DSSC delivers a power conversion efficiency up to 6.7%, which is 1.52 times of the P25 based DSSCs. The ultra-small SnO2 NCs offer three benefits, (1) the incorporation of SnO2 NCs enlarges surface areas of the photo-anode films, and higher dye-loading amounts were achieved; (2) the high charge mobility provided by SnO2 was confirmed to accelerate the electron transport, and the photo-electron recombination was suppressed by the highly-crystallized NCs; (3) the conduction band minimum (CBM) of the SnO2 NCs was uplifted due to the quantum size effects, and this was found to alleviate the decrement in the open-circuit voltage. This work highlights great contributions of the SnO2 NCs to the improvement of the photovoltaic performances in the DSSCs. PMID:26758941

  14. Solar Indices Forecasting Tool

    NASA Astrophysics Data System (ADS)

    Henney, Carl John; Shurkin, Kathleen; Arge, Charles; Hill, Frank

    2016-05-01

    Progress to forecast key space weather parameters using SIFT (Solar Indices Forecasting Tool) with the ADAPT (Air Force Data Assimilative Photospheric flux Transport) model is highlighted in this presentation. Using a magnetic flux transport model, ADAPT, we estimate the solar near-side field distribution that is used as input into empirical models for predicting F10.7(solar 10.7 cm, 2.8 GHz, radio flux), the Mg II core-to-wing ratio, and selected bands of solar far ultraviolet (FUV) and extreme ultraviolet (EUV) irradiance. Input to the ADAPT model includes the inferred photospheric magnetic field from the NISP ground-based instruments, GONG & VSM. Besides a status update regarding ADAPT and SIFT models, we will summarize the findings that: 1) the sum of the absolute value of strong magnetic fields, associated with sunspots, is shown to correlate well with the observed daily F10.7 variability (Henney et al. 2012); and 2) the sum of the absolute value of weak magnetic fields, associated with plage regions, is shown to correlate well with EUV and FUV irradiance variability (Henney et al. 2015). This work utilizes data produced collaboratively between Air Force Research Laboratory (AFRL) and the National Solar Observatory (NSO). The ADAPT model development is supported by AFRL. The input data utilized by ADAPT is obtained by NISP (NSO Integrated Synoptic Program). NSO is operated by the Association of Universities for Research in Astronomy (AURA), Inc., under a cooperative agreement with the National Science Foundation (NSF). The 10.7 cm solar radio flux data service, utilized by the ADAPT/SIFT F10.7 forecasting model, is operated by the National Research Council of Canada and National Resources Canada, with the support of the Canadian Space Agency.

  15. Agency, time, and causality

    PubMed Central

    Widlok, Thomas

    2014-01-01

    Cognitive Scientists interested in causal cognition increasingly search for evidence from non-Western Educational Industrial Rich Democratic people but find only very few cross-cultural studies that specifically target causal cognition. This article suggests how information about causality can be retrieved from ethnographic monographs, specifically from ethnographies that discuss agency and concepts of time. Many apparent cultural differences with regard to causal cognition dissolve when cultural extensions of agency and personhood to non-humans are taken into account. At the same time considerable variability remains when we include notions of time, linearity and sequence. The article focuses on ethnographic case studies from Africa but provides a more general perspective on the role of ethnography in research on the diversity and universality of causal cognition. PMID:25414683

  16. Combining Epidemiologic Information Across Space Agencies

    NASA Technical Reports Server (NTRS)

    Minard, Charles G.; Clark, April L.; Wear, Mary L.; Mason, Sara; Van Baalen, Mary

    2010-01-01

    Space flight is a very unique occupational exposure with potential hazards that are not fully understood. A limited number of individuals have experienced the exposures incurred during space flight, and epidemiologic research would benefit from shared information across space agencies. However, data sharing can be problematic due to agency protection policies for personally identifiable information as well as medical records. Compliance with these protocols in the astronaut population is particularly difficult given the small, high-profile population under study. Creativity in combining data is necessary in order to overcome these difficulties and improve statistical power in research. This study presents methods in meta-analysis that may be used to combine non-attributable data across space agencies so that meaningful conclusions may be drawn about study interests. Methods for combining epidemiologic data across space agencies are presented, and the processes are demonstrated using life-time mortality data in U.S. astronauts and Russian cosmonauts. This proof of concept was found to be an acceptable way of sharing data across agencies, and will be used in the future as more relevant research interests are identified.

  17. 77 FR 28237 - Small Business Size Regulations; 8(a) Business Development/Small Disadvantaged Business Status...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-05-14

    ... / Monday, May 14, 2012 / Rules and Regulations#0;#0; ] SMALL BUSINESS ADMINISTRATION 13 CFR Part 124 RIN 3245-AF53 Small Business Size Regulations; 8(a) Business Development/Small Disadvantaged Business Status Determinations; Correction AGENCY: U.S. Small Business Administration. ACTION:...

  18. Solar Simulator

    NASA Technical Reports Server (NTRS)

    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.

  19. Solar Physics

    NASA Technical Reports Server (NTRS)

    Wu, S. T.

    2000-01-01

    The areas of emphasis are: (1) develop theoretical models of the transient release of magnetic energy in the solar atmosphere, e.g., in solar flares, eruptive prominences, coronal mass ejections, etc.; (2) investigate the role of the Sun's magnetic field in the structuring of solar corona by the development of three-dimensional numerical models that describe the field configuration at various heights in the solar atmosphere by extrapolating the field at the photospheric level; (3) develop numerical models to investigate the physical parameters obtained by the ULYSSES mission; (4) develop numerical and theoretical models to investigate solar activity effects on the solar wind characteristics for the establishment of the solar-interplanetary transmission line; and (5) develop new instruments to measure solar magnetic fields and other features in the photosphere, chromosphere transition region and corona. We focused our investigation on the fundamental physical processes in solar atmosphere which directly effect our Planet Earth. The overall goal is to establish the physical process for the Sun-Earth connections.

  20. Distant Comets in the Early Solar System

    NASA Technical Reports Server (NTRS)

    Meech, Karen J.

    2000-01-01

    The main goal of this project is to physically characterize the small outer solar system bodies. An understanding of the dynamics and physical properties of the outer solar system small bodies is currently one of planetary science's highest priorities. The measurement of the size distributions of these bodies will help constrain the early mass of the outer solar system as well as lead to an understanding of the collisional and accretional processes. A study of the physical properties of the small outer solar system bodies in comparison with comets in the inner solar system and in the Kuiper Belt will give us information about the nebular volatile distribution and small body surface processing. We will increase the database of comet nucleus sizes making it statistically meaningful (for both Short-Period and Centaur comets) to compare with those of the Trans-Neptunian Objects. In addition, we are proposing to do active ground-based observations in preparation for several upcoming space missions.

  1. Financing Solar Thermal Power Plants

    SciTech Connect

    Price, H. W.; Kistner, R.

    1999-11-01

    The commercialization of concentrating solar power technology took a major step forward in the mid 1980s and early 1990s with the development of the SEGS plants in California. Over the years they have proven that parabolic trough power technologies are the most cost-effective approach for commercial scale solar power generation in the sunbelt countries of the world. However, the question must be asked why no additional solar power plants have been build following the bankruptcy of the developer of the SEGS projects, LUZ International Limited. Although many believe the SEGS projects were a success as a result of parabolic trough technology they employ, in truth, the SEGS projects were developed simply because they represented an attractive opportunity for investors. Simply stated, no additional projects have been developed because no one has been able to put together a similarly attractive financial package to potential investors. More than $1.2 billion in private capital was raised i n debt and equity financing for the nine SEGS plants. Investors and bankers who make these investments are the real clients for solar power technologies. They are not interested in annual solar to electric efficiencies, but in risk, return on investments, and coverage ratios. This paper will take a look at solar power projects from the financier's perspective. The challenge in moving forward is to attract private investors, commercial lenders, and international development agencies and to find innovative solutions to the difficult issues that investment in the global power market poses for solar power technologies.

  2. Largest Solar Flare on Record

    NASA Technical Reports Server (NTRS)

    2001-01-01

    The largest solar flare ever recorded occurred at 4:51 p.m. EDT, on Monday, April 2, 2001. as Observed by the Solar and Heliospheric Observatory (SOHO) satellite. Solar flares, among the solar systems mightiest eruptions, are tremendous explosions in the atmosphere of the Sun capable of releasing as much energy as a billion megatons of TNT. Caused by the sudden release of magnetic energy, in just a few seconds, solar flares can accelerate solar particles to very high velocities, almost to the speed of light, and heat solar material to tens of millions of degrees. The recent explosion from the active region near the sun's northwest limb hurled a coronal mass ejection into space at a whopping speed of roughly 7.2 million kilometers per hour. Luckily, the flare was not aimed directly towards Earth. Second to the most severe R5 classification of radio blackout, this flare produced an R4 blackout as rated by the NOAA SEC. This classification measures the disruption in radio communications. Launched December 2, 1995 atop an ATLAS-IIAS expendable launch vehicle, the SOHO is a cooperative effort involving NASA and the European Space Agency (ESA). (Image courtesy NASA Goddard SOHO Project office)

  3. 77 FR 41403 - Meetings of the Local Government Advisory Committee and the Small Communities Advisory...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-13

    ... Subcommittee (SCAS) AGENCY: Environmental Protection Agency. ACTION: Notice. SUMMARY: The Small Communities... From the Federal Register Online via the Government Publishing Office ENVIRONMENTAL PROTECTION... issues and recommendations regarding environmental issues affecting small communities. The...

  4. 48 CFR 970.1907 - Subcontracting with Small Business, Small Disadvantaged Business and Woman-Owned Small Business...

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 48 Federal Acquisition Regulations System 5 2010-10-01 2010-10-01 false Subcontracting with Small Business, Small Disadvantaged Business and Woman-Owned Small Business Concerns. 970.1907 Section 970.1907 Federal Acquisition Regulations System DEPARTMENT OF ENERGY AGENCY SUPPLEMENTARY REGULATIONS...

  5. 14 CFR 1267.645 - Federal agency or agency.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 5 2012-01-01 2012-01-01 false Federal agency or agency. 1267.645 Section 1267.645 Aeronautics and Space NATIONAL AERONAUTICS AND SPACE ADMINISTRATION GOVERNMENTWIDE... Executive Office of the President), or any independent regulatory agency....

  6. 14 CFR 1267.645 - Federal agency or agency.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 5 2011-01-01 2010-01-01 true Federal agency or agency. 1267.645 Section 1267.645 Aeronautics and Space NATIONAL AERONAUTICS AND SPACE ADMINISTRATION GOVERNMENTWIDE... Executive Office of the President), or any independent regulatory agency....

  7. 31 CFR 20.645 - Federal agency or agency.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 31 Money and Finance: Treasury 1 2010-07-01 2010-07-01 false Federal agency or agency. 20.645 Section 20.645 Money and Finance: Treasury Office of the Secretary of the Treasury GOVERNMENTWIDE REQUIREMENTS FOR DRUG-FREE WORKPLACE (FINANCIAL ASSISTANCE) Definitions § 20.645 Federal agency or...

  8. 31 CFR 20.645 - Federal agency or agency.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 31 Money and Finance: Treasury 1 2012-07-01 2012-07-01 false Federal agency or agency. 20.645 Section 20.645 Money and Finance: Treasury Office of the Secretary of the Treasury GOVERNMENTWIDE REQUIREMENTS FOR DRUG-FREE WORKPLACE (FINANCIAL ASSISTANCE) Definitions § 20.645 Federal agency or...

  9. 31 CFR 20.645 - Federal agency or agency.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 31 Money and Finance: Treasury 1 2013-07-01 2013-07-01 false Federal agency or agency. 20.645 Section 20.645 Money and Finance: Treasury Office of the Secretary of the Treasury GOVERNMENTWIDE REQUIREMENTS FOR DRUG-FREE WORKPLACE (FINANCIAL ASSISTANCE) Definitions § 20.645 Federal agency or...

  10. 31 CFR 20.645 - Federal agency or agency.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 31 Money and Finance: Treasury 1 2014-07-01 2014-07-01 false Federal agency or agency. 20.645 Section 20.645 Money and Finance: Treasury Office of the Secretary of the Treasury GOVERNMENTWIDE REQUIREMENTS FOR DRUG-FREE WORKPLACE (FINANCIAL ASSISTANCE) Definitions § 20.645 Federal agency or...

  11. 31 CFR 20.645 - Federal agency or agency.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 31 Money and Finance: Treasury 1 2011-07-01 2011-07-01 false Federal agency or agency. 20.645 Section 20.645 Money and Finance: Treasury Office of the Secretary of the Treasury GOVERNMENTWIDE REQUIREMENTS FOR DRUG-FREE WORKPLACE (FINANCIAL ASSISTANCE) Definitions § 20.645 Federal agency or...

  12. 21 CFR 1404.910 - Agency.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...) Definitions § 1404.910 Agency. Agency means any United States executive department, military department, defense agency, or any other agency of the executive branch. Other agencies of the Federal government...

  13. 21 CFR 1404.910 - Agency.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...) Definitions § 1404.910 Agency. Agency means any United States executive department, military department, defense agency, or any other agency of the executive branch. Other agencies of the Federal government...

  14. 22 CFR 1508.910 - Agency.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...) Definitions § 1508.910 Agency. Agency means any United States executive department, military department, defense agency, or any other agency of the executive branch. Other agencies of the Federal government...

  15. 22 CFR 1508.910 - Agency.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...) Definitions § 1508.910 Agency. Agency means any United States executive department, military department, defense agency, or any other agency of the executive branch. Other agencies of the Federal government...

  16. 21 CFR 1404.910 - Agency.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...) Definitions § 1404.910 Agency. Agency means any United States executive department, military department, defense agency, or any other agency of the executive branch. Other agencies of the Federal government...

  17. 31 CFR 19.910 - Agency.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... (NONPROCUREMENT) Definitions § 19.910 Agency. Agency means any United States executive department, military department, defense agency, or any other agency of the executive branch. Other agencies of the...

  18. 21 CFR 1404.910 - Agency.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...) Definitions § 1404.910 Agency. Agency means any United States executive department, military department, defense agency, or any other agency of the executive branch. Other agencies of the Federal government...

  19. 22 CFR 1508.910 - Agency.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...) Definitions § 1508.910 Agency. Agency means any United States executive department, military department, defense agency, or any other agency of the executive branch. Other agencies of the Federal government...

  20. 22 CFR 1508.910 - Agency.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...) Definitions § 1508.910 Agency. Agency means any United States executive department, military department, defense agency, or any other agency of the executive branch. Other agencies of the Federal government...