Science.gov

Sample records for agency small solar

  1. Central Receiver System (CRS) in the Small Solar Power Systems Project (SSPS) of the International Energy Agency (IEA)

    NASA Astrophysics Data System (ADS)

    Grasse, W.; Becker, M.

    1984-02-01

    Attention is given to the design features and performance of the Small Solar Power Systems Project's Central Receiver System (CRS). The heliostat field used has a total reflective surface of 3655 sq m and focuses the irradiated power on an aperture plane of 9.2 sq m atop the tower. The cavity-type receiver is rated at 2840 kW at design conditions, of which 88.3 percent is absorbed by the liquid sodium heat transfer fluid as it is heated from 275 to 530 C. The major part of the CRS's Rankine power conversion cycle is a five-stage steam motor with two preheaters. Attention is given to CRS program funding responsibilities and development milestone chronology.

  2. 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.

  3. 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.

  4. 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.

  5. Infrared observations of small solar system bodies

    NASA Technical Reports Server (NTRS)

    Brown, R. H.

    1991-01-01

    Infrared reflectance spectra were measured of dark primitive asteroids in the 2 to 5 micron wavelength region. The search was for organic complexes such and CN, CH, and NH in dark material on small bodies in the solar system. A search and study was made of volatiles such as nitrogen, methane, ammonia, and carbon monoxide, both as free ices and hydrates/clathrates, on icy surfaces in the outer solar system, using high resolution spectra obtained with a multichannel cooled grating, infrared spectrometer. An absorption that can be attributed to X-C (triple bond) N in the matrix of dark materials on the primitive asteroids.

  6. Small grains of truth. [solar system evolution

    NASA Technical Reports Server (NTRS)

    Nuth, Joe

    1991-01-01

    The evidence concerning the formation of the solar nebula from preexisting clouds found in the chemical composition of solar system grains is discussed. Evidence for sequential star formation in the grains is examined. It is argued that there is no model for the origin of the solar system which can account for the increasing complexity of the evidence.

  7. 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.

  8. 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

  9. 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.

  10. 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.

  11. The small community solar thermal power experiment

    NASA Astrophysics Data System (ADS)

    Kiceniuk, T.

    1981-05-01

    Contractors were asked to develop a preferred system concept, to perform sensitivity analyses, and to outline recommended approaches for the follow-on design program of a one-megawatt solar thermal demonstration plant. The systems recommended by the contractors in each of the categories were: (1) McDonnell-Douglas Astronautics Company: Central tower with field of south-facing heliostats; (2) General Electric Company: Field of parabolic dishes with steam piped to a central turbine-generator unit; and (3) Ford Aerospace and Communications Corporation: Field of parabolic dishes with a Stirling cycle engine/generator unit at the focus of each dish. A description of each of the proposed experimental plants is given.

  12. The small community solar thermal power experiment

    NASA Technical Reports Server (NTRS)

    Kiceniuk, T.

    1981-01-01

    Contractors were asked to develop a preferred system concept, to perform sensitivity analyses, and to outline recommended approaches for the follow-on design program of a one-megawatt solar thermal demonstration plant. The systems recommended by the contractors in each of the categories were: (1) McDonnell-Douglas Astronautics Company: Central tower with field of south-facing heliostats; (2) General Electric Company: Field of parabolic dishes with steam piped to a central turbine-generator unit; and (3) Ford Aerospace and Communications Corporation: Field of parabolic dishes with a Stirling cycle engine/generator unit at the focus of each dish. A description of each of the proposed experimental plants is given.

  13. 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.

  14. 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.

  15. Advances in simulation study on organic small molecular solar cells

    NASA Astrophysics Data System (ADS)

    Zhang, Xuan; Guo, Wenge; Li, Ming; Ma, Wentao; Meng, Sen

    2015-02-01

    Recently, more focuses have been put on organic semiconductors because of its advantages, such as its flexibility, ease of fabrication and potential low cost, etc. The reasons we pay highlight on small molecular photovoltaic material are its ease of purification, easy to adjust and determine structure, easy to assemble range units and get high carrier mobility, etc. Simulation study on organic small molecular solar cells before the experiment can help the researchers find relationship between the efficiency and structure parameters, properties of material, estimate the performance of the device, bring the optimization of guidance. Also, the applicability of the model used in simulation can be discussed by comparison with experimental data. This paper summaries principle, structure, progress of numerical simulation on organic small molecular solar cells.

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. Solar produced alcohol for the small farm. Final technical report

    SciTech Connect

    Kriley, D.B.

    1985-01-01

    Results obtained during the operation of a small-scale ethanol plant on a farm are reported. It is shown that: (1) ethanol can be produced from corn without the use of expensive commercial enzymes and expensive heating systems; (2) ethanol can be produced the small farm with temperatures under 130/sup 0/F through the entire process. (Solar energy is definitely usable in these temperature ranges); (3) locally obtained equipment can be used to build a low temperature distillation system (for example, stainless bulk milk tanks, surplus glass, aluminum roofing, etc.); (4) cost per gallon of ethanol is greatly reduced by producing ethanol on farm; and (5) energy consumed to produced ethanol is reduced by as much 30,000 Btu's in the distillation process. The best commercial fossil fuel systems use at least 20,000 Btu in distillation. This alone represents about half of the Btu's normally used in alcohol production. The author recommends that the model farm ethanol plant should use the following equipment: (1) solar heat (ethanol fired backup); (2) continuous fermenter (use less fermentation tanks); and (3) vacuum still (uses low temperature; can utilize stored solar heat more effectively).

  4. Quasistationary parameters of the small bodies of the solar system

    SciTech Connect

    Kramer, E.N.; Shestaka, I.S.

    1987-07-01

    The following quasistationary parameters of the small bodies of the solar system are introduced: P = 0.6/a -(a(1 - e/sup 2/))cos/sup 2/i - 2, Q = 0.4 + (2a - 1) (1 - e/sup 2/)cos/sup 2/i - e/sup 2/ (0.4 - sin/sup 2/ omega x sin/sup 2/i). They are investigated on the basis of data of photographic and radar observations of meteors, comets, and asteroids of the Apollo - Amur group. The quasistationary parameters P and Q can be applied to judge the genetic relationship between the bodies under investigation and to determine the probabilities of their encounter with the planets and the influx of meteoric material onto the planets of the solar system.

  5. Solar water heating -- guidance for small facilities. Tech data sheet

    SciTech Connect

    Rocha, M.

    1996-05-01

    Water heating accounts for a substantial portion of energy use at many Federal facilities. Of the total energy used, approximately 18 percent in residential and 4 percent in commercial buildings is for water heating; that percentage may be much higher for buildings with laundries, kitchens, showers, or swimming pools. Nearly all hot water in the United States is heated directly or indirectly through the combustion of some fossil fuel. Because of these dwindling, nonrenewable resources and stricter air pollution standards, it is recommended that Federal facility managers investigate and take advantage of existing solar water heating technology. This TechData sheet is to help activity personnel determine the feasibility, reliability, and cost effectiveness of domestic solar water heating systems for small buildings. With this guide, an energy manager can evaluate the various system options available.

  6. 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.

  7. The Fabry-Perot interferometer prototype for the ADAHELI solar small mission

    NASA Astrophysics Data System (ADS)

    Berrilli, Francesco; Cocciolo, Martina; Giovannelli, Luca; Del Moro, Dario; Giannattasio, Fabio; Piazzesi, Roberto; Stangalini, Marco; Egidi, Alberto; Cavallini, Fabio; Greco, Vincenzo; Selci, Stefano

    2011-10-01

    ADAHELI ADvanced Astronomy for HELIophysics is a solar satellite designed to investigate the fast dynamics of the solar photosphere and chromosphere performing visible and NIR broad-band and monochromatic observations of selected atomic lines. ADAHELI is an Italian Space Agency (ASI) project, approved for a feasibility study within the ASI Small Missions call. ISODY Interferometer for SOlar DYnamics is a Gregorian telescope and its focal plane suite (FPS). The FPS is composed of a high-resolution fast acquisition system, based upon a tandem of Fabry-Pérot interferometers operating in the visible and NIR regions on selected solar atmospheric lines, a broad band channel, and a correlation tracker used as image stabilization system. In this contribution we describe the Fabry-Pérot étalon prototype, based on the capacitance-stabilised concept, realized in our laboratory to perform preliminary mechanical and optical tests with a view to a future Fabry-Pérot étalon prototype for space application.

  8. 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.

  9. 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.

  10. 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.

  11. Small is different: RPC observations of a small scale comet interacting with the solar wind

    NASA Astrophysics Data System (ADS)

    Nilsson, Hans; Burch, James L.; Carr, Christopher M.; Eriksson, Anders I.; Glassmeier, Karl-Heinz; Henri, Pierre; Rosetta Plasma Consortium Team

    2016-10-01

    Rosetta followed comet 67P from low activity at more than 3 AU heliocentric distance to peak activity at perihelion and then out again. We study the evolution of the dynamic plasma environment using data from the Rosetta Plasma Consortium (RPC). Observations of cometary plasma began in August 2014, at a distance of 100 km from the comet nucleus and at 3.6 AU from the Sun. As the comet approached the Sun, outgassing from the comet increased, as did the density of the cometary plasma. Measurements showed a highly heterogeneous cold ion environment, permeated by the solar wind. The solar wind was deflected due to the mass loading from newly added cometary plasma, with no discernible slowing down. The magnetic field magnitude increased significantly above the background level, and strong low frequency waves were observed in the magnetic field, a.k.a. the "singing comet". Electron temperatures were high, leading to a frequently strongly negative spacecraft potential. In mid to late April 2015 the solar wind started to disappear from the observation region. This was associated with a solar wind deflection reaching nearly 180°, indicating that mass loading became efficient enough to form a solar wind-free region. Accelerated water ions, moving mainly in the anti-sunward direction, kept being observed also after the solar wind disappearance. Plasma boundaries began to form and a collisionopause was tentatively identified in the ion and electron data. At the time around perihelion, a diamagnetic cavity was also observed, at a surprisingly large distance from the comet. In late 2016 the solar wind re-appeared at the location of Rosetta, allowing for studies of asymmetry of the comet ion environment with respect to perihelion. A nightside excursion allowed us to get a glimpse of the electrodynamics of the innermost part of the plasma tail. Most of these phenomena are dependent on the small-scale physics of comet 67P, since for most of the Rosetta mission the solar wind

  12. Advanced glazing and associated materials for solar and building applications: International Energy Agency Solar Heating and Cooling Program Task 18

    NASA Astrophysics Data System (ADS)

    Hutchins, Michael G.

    1992-11-01

    Following a program definition phase of 2 years, Task 18 of the International Energy Agency Solar Heating & Cooling program commenced a 5 year research phase in April 1992. Task 18 investigates a wide range of advanced glazing materials and glazing systems which include monolithic and granular aerogels, transparent insulation materials, chromogenic materials, evacuated glazings, low-emittance coatings, solar collector covers, angular selective transmittance thin films, holographic and light guide materials, and frame and edge seal technology. In addition to materials-centered research, Task 18 concentrates on measurement of key glazing properties such as total energy transmittance, U-value, and spectral directional optical properties, and through the use of building energy analysis software tools the identification of appropriate applications, control strategies, and energy and environmental benefits to be derived from advanced glazing products. Fifteen OECD countries are participating in Task 18 which is led by the United Kingdom.

  13. Studies of relationships among outer solar system small bodies and related objects

    NASA Technical Reports Server (NTRS)

    Hartmann, William K.

    1991-01-01

    This program involves telescopic observations of colorimetry, spectroscopy, and photometry of small bodies of the solar system, emphasizing possible relationships among outer solar system asteroids, comets, and certain satellites. Earth approacher targets of opportunity and lab spectroscopic studies are included.

  14. 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.

  15. 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.

  16. 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.

  17. 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).

  18. General Relativistic Precession in Small Solar System Bodies

    NASA Astrophysics Data System (ADS)

    Sekhar, Aswin; Werner, Stephanie; Hoffmann, Volker; Asher, David; Vaubaillon, Jeremie; Hajdukova, Maria; Li, Gongjie

    2016-10-01

    Introduction: One of the greatest successes of the Einstein's General Theory of Relativity (GR) was the correct prediction of the precession of perihelion of Mercury. The closed form expression to compute this precession tells us that substantial GR precession would occur only if the bodies have a combination of both moderately small perihelion distance and semi-major axis. Minimum Orbit Intersection Distance (MOID) is a quantity which helps us to understand the closest proximity of two orbits in space. Hence evaluating MOID is crucial to understand close encounters and collision scenarios better. In this work, we look at the possible scenarios where a small GR precession in argument of pericentre (ω) can create substantial changes in MOID for small bodies ranging from meteoroids to comets and asteroids.Analytical Approach and Numerical Integrations: Previous works have looked into neat analytical techniques to understand different collision scenarios and we use those standard expressions to compute MOID analytically. We find the nature of this mathematical function is such that a relatively small GR precession can lead to drastic changes in MOID values depending on the initial value of ω. Numerical integrations were done with package MERCURY incorporating the GR code to test the same effects. Numerical approach showed the same interesting relationship (as shown by analytical theory) between values of ω and the peaks/dips in MOID values. Previous works have shown that GR precession suppresses Kozai oscillations and this aspect was verified using our integrations. There is an overall agreement between both analytical and numerical methods.Summary and Discussion: We find that GR precession could play an important role in the calculations pertaining to MOID and close encounter scenarios in the case of certain small solar system bodies (depending on their initial orbital elements). Previous works have looked into impact probabilities and collision scenarios on

  19. Destruction of small bodies of the Solar System: stochastic modeling

    NASA Astrophysics Data System (ADS)

    Kulikova, N. V.; Myshev, A. V.; Chepurova, V. M.

    It is considered that small bodies of Solar system, i.e. comets, asteroids and etc., are the primary sources of meteoric sunstance inflow in space. The most probable mechanisms of substance ejection from the surface of these bodies are dust ejections from sublimating ice cometary nuclei and fragmentation of asteroids, comets and larger meteor bodies at collisions. The hypotheses are discussed that most meteor bodies are fragments of asteroids. An interest is renewed for the relationship between meteor bodies and asteroidsapproaching Earth. The conception of continuous formation of the interplanetary complex of small bodies is quite real. Realization of this idea gives rise to developing ,methods for formalization of a stochastic process of substance eruption at any space point and constructing models of formed new classes of small bodies. The authors have substantiated the rightfulness of application of stohastic methods of simulation in problems of cosmogony of small bodies and estimated the level of their informativeness. Simulation algorithms are developed of disintegration an eruption of celestial bodies at any space point with allowance for the effect of a maximum quantity of gravitational and non-gravitational factors on fragment motion considering variations in the motion of parent bodies. A method is being developed for constructing the probabitity measure in a phase space. A probability measure includes the whole substancial information about quantitave chracteristics of a certain dynamics system behaviour. Computer experiments on comet and asteroid disintegration have been perfomed using developed stochastic models; the relationship between these objects and concrete meteor streams was established. Obtained results show the prospects of a developed method for problems of celestial mechanics.

  20. 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.

  1. 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.

  2. Some features of the small-scale solar wind fluctuations

    NASA Technical Reports Server (NTRS)

    Zastenker, G.; Eiges, P.; Avanov, L.; Astafyeva, N.; Zurbuchen, Th.; Bochsler, P.

    1995-01-01

    We have investigated small-scale variations of the solar wind ion flux measured with Faraday cups onboard the Prognoz-8 satellite. These measurements have a high time resolution of 1.24 seconds for intervals with a duration of several hours and as high as 0.02 seconds for some periods of about 1 hour duration. The main goal of this work is the determination of the quantitative features of fast ion flux fluctuations using mainly spectral analysis but also other methods. We also identify their association with interplanetary plasma parameters. Particularly, it is shown that the slope of the power spectra in the frequency range from 1E-4 to 6E-2 Hz is close to the classical Kolmogorov (-5/3) law. We also discuss some intervals with a very high level of the relative amplitude of flux fluctuations (10-20 percent) which were observed near the Earth's bow shock in the foreshock region. The use of the wavelet method for the long time series allows us to study the temporal evolution of power spectra.

  3. 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

  4. 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.

  5. Some features of the small-scale solar wind fluctuations

    NASA Astrophysics Data System (ADS)

    Zastenker, G.; Eiges, P.; Avanov, L.; Astafyeva, N.; Zurbuchen, Th.; Bochsler, P.

    1995-06-01

    We have investigated small-scale variations of the solar wind ion flux measured with Faraday cups onboard the Prognoz-8 satellite. These measurements have a high time resolution of 1.24 seconds for intervals with a duration of several hours and as high as 0.02 seconds for some periods of about 1 hour duration. The main goal of this work is the determination of the quantitative features of fast ion flux fluctuations using mainly spectral analysis but also other methods. We also identify their association with interplanetary plasma parameters. Particularly, it is shown that the slope of the power spectra in the frequency range from 1E-4 to 6E-2 Hz is close to the classical Kolmogorov (-5/3) law. We also discuss some intervals with a very high level of the relative amplitude of flux fluctuations (10-20 percent) which were observed near the Earth's bow shock in the foreshock region. The use of the wavelet method for the long time series allows us to study the temporal evolution of power spectra.

  6. Structures and Intermittency in Small Scales Solar Wind Turbulence

    SciTech Connect

    Sahraoui, Fouad; Goldstein, Melvyn

    2010-03-25

    Several observations in space plasmas have reported the presence of coherent structures at different plasma scales. Structure formation is believed to result from nonlinear interactions between the plasma modes, which depend strongly on their phase synchronization. Despite this important role of the phases in turbulence, very limited work has been devoted to study the phases as potential tracers of nonlinearities in comparison with the wealth of literature on power spectra of turbulence where phases are totally missed. The reason why the phases are seldom used is probably because they usually appear to be completely mixed (due to their dependence on an arbitrary time origin and to 2pi periodicity). To handle the phases properly, a new method based on using surrogate data has been developed recently to detect coherent structures in magnetized plasmas [Sahraoui, PRE, 2008]. Here, we show new applications of the technique to study the nature (weak vs strong, self-similar vs intermittent) of the small scale turbulence in the solar wind using the Cluster observations.

  7. 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

  8. 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.

  9. 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.

  10. 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.

  11. 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

  12. 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... discuss issues related to a petition for rulemaking recently submitted by the Solar Energy Industries... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY...

  13. 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.

  14. 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.

  15. 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

    2013-11-28

    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.

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

    PubMed Central

    Liu, Yongsheng; Chen, Chun-Chao; Hong, Ziruo; Gao, Jing; (Michael) Yang, Yang; 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

  17. 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.

  18. 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

  19. 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.

  20. 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

  1. 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

  2. JPL - Small Power Systems Applications Project. [for solar thermal power plant development and commercialization

    NASA Technical Reports Server (NTRS)

    Ferber, R. R.; Marriott, A. T.; Truscello, V.

    1978-01-01

    The Small Power Systems Applications (SPSA) Project has been established to develop and commercialize small solar thermal power plants. The technologies of interest include all distributed and central receiver technologies which are potentially economically viable in power plant sizes of one to 10 MWe. The paper presents an overview of the SPSA Project and briefly discusses electric utility involvement in the Project.

  3. 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.

  4. 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

  5. Observational Criteria For Small-scale Turbulent Dynamo In The Solar Photosphere

    NASA Astrophysics Data System (ADS)

    Abramenko, Valentyna; Goode, P.; Yurchyshyn, V.

    2012-05-01

    Generation and dispersal of the magnetic field on the Sun is a key mechanism responsible for solar activity on all spatial and temporal scales - from the solar cycle down to the evolution of small-scale magnetic elements in the quiet Sun. The solar dynamo operates as a non-linear dynamical process and is thought to be manifested in two types: as a global dynamo responsible for the solar cycle periodicity, and as a small-scale turbulent dynamo (SSTD) responsible for the formation of magnetic carpet in the quiet Sun. Numerous MHD simulations of the solar turbulence did not yet reach a consensus as to the existence and role of SSTD on the Sun. At the same time, high-resolution observations of the quiet Sun are capable to provide certain criteria to prove or rule out SSTD. We suggest to probe four possible criteria: i) mutual behaviour of the kinetic and magnetic power spectra; ii) intermittency/multifractality of the magnetic field; iii) smallest observed scale of magnetic flux tubes; iv) regime of magnetic diffusivity on smallest observable scales. We analyse magnetic, velocity and solar granulation data as derived from Hinode/SOT, SOHO/MDI, SDO/HMI and the New Solar Telescope (NST) of Big Bear Solar Observatory (BBSO) to explore the possibilities for SSTD in the quiet Sun.

  6. 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.

  7. 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.

  8. 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.

  9. AM-1 short circuit currents in small area PIN a-SiH(x) solar cells

    NASA Astrophysics Data System (ADS)

    Weinberger, B. R.; Deckman, H. W.; Wronski, C. R.; Witzke, H.

    The potential pitfalls which may lead to an overestimation of AM-1 short-circuit current densities have been investigated for 0.02 sq cm a-SiH(x) solar cell structures. The investigators have spatially profiled carrier collection in a-Si PIN solar cells, using a scanned 10 micron diameter laser beam. The small beam size yields not only microscopic information about carrier collection efficiency spectra, but permits study of carrier collection at high light intensity without significantly heating the cell. Laser scans at low illumination levels were employed to determine the true active area of PIN solar cells, and these are compared to cell collection efficiency spectra.

  10. 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.

  11. 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.

  12. 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.

  13. THE SUN'S SMALL-SCALE MAGNETIC ELEMENTS IN SOLAR CYCLE 23

    SciTech Connect

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

    2011-04-10

    With the unique database from the Michelson Doppler Imager on board the Solar and Heliospheric Observatory in an interval embodying solar cycle 23, the cyclic behavior of solar small-scale magnetic elements is studied. More than 13 million small-scale magnetic elements are selected, and the following results are found. (1) The quiet regions dominated the Sun's magnetic flux for about 8 years in the 12.25 year duration of cycle 23. They contributed (0.94-1.44) x10{sup 23} Mx flux to the Sun from the solar minimum to maximum. The monthly average magnetic flux of the quiet regions is 1.12 times that of the active regions in the cycle. (2) The ratio of quiet region flux to that of the total Sun equally characterizes the course of a solar cycle. The 6 month running average flux ratio of the quiet regions was larger than 90.0% for 28 continuous months from July 2007 to October 2009, which very well characterizes the grand solar minima of cycles 23-24. (3) From the small to the large end of the flux spectrum, the variations of numbers and total flux of the network elements show no correlation, anti-correlation, and correlation with sunspots, respectively. The anti-correlated elements, covering the flux of (2.9-32.0)x10{sup 18} Mx, occupy 77.2% of the total element number and 37.4% of the quiet-Sun flux. These results provide insight into the reason for anti-correlations of small-scale magnetic activity during the solar cycle.

  14. 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

  15. 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.

  16. 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].

  17. 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)

  18. 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.

  19. Solution processed polymer tandem solar cell using efficient small and wide bandgap polymer:fullerene blends.

    PubMed

    Gevaerts, Veronique S; Furlan, Alice; Wienk, Martijn M; Turbiez, Mathieu; Janssen, René A J

    2012-04-24

    Solution processed polymer tandem solar cells that combine wide and small bandgap absorber layers reach a power conversion efficiency of 7% in a series configuration. This represents a 20% increase compared to the best single junction cells made with the individual active layers and shows that the tandem configuration reduces transmission and thermalization losses in converting sunlight. PMID:22438114

  20. Solution-processed small-molecule solar cells with 6.7% efficiency

    SciTech Connect

    Sun, Yanming; Welch, Gregory C.; Leong, Wei Lin; Takacs, Christopher J.; Bazan, Guillermo C.; Heeger, Alan J.

    2011-11-06

    Organic photovoltaic devices that can be fabricated by simple processing techniques are under intense investigation in academic and industrial laboratories because of their potential to enable mass production of flexible and cost-effective devices. Most of the attention has been focused on solution-processed polymer bulk-heterojunction (BHJ) solar cells. A combination of polymer design, morphology control, structural insight and device engineering has led to power conversion efficiencies (PCEs) reaching the 6–8% range for conjugated polymer/fullerene blends. Solution-processed small-molecule BHJ (SM BHJ) solar cells have received less attention, and their efficiencies have remained below those of their polymeric counterparts. Here, we report efficient solution-processed SM BHJ solar cells based on a new molecular donor, DTS(PTTh₂)₂. A record PCE of 6.7% under AM 1.5 G irradiation (100 mW cm⁻²) is achieved for small-molecule BHJ devices from DTS(PTTh₂)₂:PC₇₀BM (donor to acceptor ratio of 7:3). This high efficiency was obtained by using remarkably small percentages of solvent additive (0.25% v/v of 1,8-diiodooctane, DIO) during the film-forming process, which leads to reduced domain sizes in the BHJ layer. These results provide important progress for solution-processed organic photovoltaics and demonstrate that solar cells fabricated from small donor molecules can compete with their polymeric counterparts.

  1. 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).

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

    NASA Astrophysics Data System (ADS)

    Wei, F.; Hu, Q.; Feng, X.

    Some observational examples for the possible occurrence of the turbulent magnetic reconnection in the solar wind are found by analyzing Helios 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 solar wind, which is a basic feature characterizing the magnetic reconnection in high-magnetic Reynolds number (RM=2 000--10 000) solar wind. The configurations of the magnetic reconnection could evolve fro m a single X-line to a multiple X-line reconnection, exhibiting a complex picture of the formation, merging and evolution of magnetic islands, and finally the magnetic reconnection would evolve into a low-energy state. Its life-span of evolution is about hour-order of magnitude. Various magnetic and flow signatures are recorded in the numerical test for different evolution stages and along different crossing paths, which could in principle explain and confirm the observational samples from the Helios spacecraft. These results are helpful for revealing the basic physical processes in the solar wind turbulence.

  3. 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.

  4. 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.

  5. 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

  6. 77 FR 32169 - Agency Requests for Renewal of a Previously Approved Information Collection: Small Business...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-05-31

    ... Office of the Secretary [Docket No. DOT-OST-2012-0080 (Formerly Docket Number DOT-OST-2008- 0182)] Agency...), Office of the Secretary of Transportation (OST), DOT. ACTION: Notice of request for comments. SUMMARY.... 20) (Formerly Docket Number DOT-OST-2008-0182), informing the public of OSDBU's intention to...

  7. 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

  8. The Moon: An Archive of Small Body Migration in the Solar System

    NASA Astrophysics Data System (ADS)

    Joy, Katherine H.; Crawford, Ian A.; Curran, Natalie M.; Zolensky, Michael; Fagan, Amy F.; Kring, David A.

    2016-10-01

    The Moon is an archive of impact cratering in the Solar System throughout the past 4.5 billion years. It preserves this record better than larger, more complex planets like the Earth, Mars and Venus, which have largely lost their ancient crusts through geological reprocessing and hydrospheric/atmospheric weathering. Identifying the parent bodies of impactors (i.e. asteroid bodies, comets from the Kuiper belt or the Oort Cloud) provides geochemical and chronological constraints for models of Solar System dynamics, helping to better inform our wider understanding of the evolution of the Solar System and the transfer of small bodies between planets. In this review article, we discuss the evidence for populations of impactors delivered to the Moon at different times in the past. We also propose approaches to the identification and characterisation of meteoritic material on the Moon in the context of future lunar exploration efforts.

  9. 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%.

  10. 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.

  11. 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.

  12. 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.

  13. 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

  14. 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.

  15. 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.

  16. On the implementation of the program for exploration of Solar System small bodies

    NASA Astrophysics Data System (ADS)

    Lomakin, I. V.; Martynov, M. B.; Pol, V. G.; Simonov, A. V.

    2014-12-01

    The paper discusses two missions for studies of various typical Solar System small bodies. The first mission is intended to study the Martian satellites and will be completed by delivering soil samples to the Earth; the second will perform a comprehensive study of a small asteroid body and deliver a radio beacon to the latter. The similarity of the technological base for both missions that enables the use of a unified design baseline is analyzed. It is suggested that the missions be joined into an integrated program consisting of two stages and that their optimal sequence order be determined.

  17. 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.

  18. Maintenance manager's manual for small transit agencies. Special report 1985-1986

    SciTech Connect

    Fowler, W.

    1988-03-01

    This publication contains information to assist operators of transit agencies providing public transportation in rural and smaller urban areas to better manage their vehicle maintenance programs. The report includes discussions of maintenance management, maintenance programs preventive maintenance, recordkeeping, selection of type of maintenance operation, in-house maintenance, and maintenance practices. Also included are appendixes giving supplementary information about tire loads; lubrication oil; mechanic hand tools; shop tools; mechanic aptitude tests; technical training resources; maintenance management training resources; and lists of manufacturers of air-conditioning systems, wheelchair lifts and wheelchair ramps.

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

    NASA Technical Reports Server (NTRS)

    Johnson, Les; Fabisinski, Leo; 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.

  20. 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

  1. The impacts of different expansion modes on performance of small solar energy firms: perspectives of absorptive capacity.

    PubMed

    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.

  2. 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.

  3. 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

  4. 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.

  5. 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.

  6. 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.

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

    PubMed

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

    2015-12-02

    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.

  8. 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.

  9. 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.

  10. 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.

  11. 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

  12. 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

  13. 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.

  14. 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

  15. 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.

  16. 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.

  17. 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

  18. 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.

  19. Formation of oligopeptides on the surface of small bodies in solar system by cosmic radiation

    NASA Astrophysics Data System (ADS)

    Simakov, M. B.; Kuzicheva, E. A.; Dodonova, N. Ya.; Antropov, A. E.

    1997-05-01

    The present experiment indicates that oligopeptides are easily produced in solid state from mixtures of simple amino acids by irradiating with high energy charged particles. We investigated such amino acids and their mixtures as tryptophan, tyrosine and glycine. The thin films was irradiated with protons (6.6 MeV). Such dipeptides as Trp-Trp, Gly-Tyr, Tyr-Gly, and Tyr-Tyr have been detected as products of irradiation. Cosmic rays might be an effective energy source for abiotic formation of bioorganic compounds on the surface of small bodies in the solar system on early stage of formation of planets as well as at present day.

  20. 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.

  1. 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.

  2. 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.

  3. Conjugated Polymer-Small Molecule Alloy Leads to High Efficient Ternary Organic Solar Cells.

    PubMed

    Zhang, Jianqi; Zhang, Yajie; Fang, Jin; Lu, Kun; Wang, Zaiyu; Ma, Wei; Wei, Zhixiang

    2015-07-01

    Ternary organic solar cells are promising candidates for bulk heterojunction solar cells; however, improving the power conversion efficiency (PCE) is quite challenging because the ternary system is complicated on phase separation behavior. In this study, a ternary organic solar cell (OSC) with two donors, including one polymer (PTB7-Th), one small molecule (p-DTS(FBTTH2)2), and one acceptor (PC71BM), is fabricated. We propose the two donors in the ternary blend forms an alloy. A notable averaged PCE of 10.5% for ternary OSC is obtained due to the improvement of the fill factor (FF) and the short-circuit current density (J(sc)), and the open-circuit voltage (V(oc)) does not pin to the smaller V(oc) of the corresponding binary blends. A highly ordered face-on orientation of polymer molecules is obtained due to the formation of an alloy structure, which facilitates the enhancement of charge separation and transport and the reduction of charge recombination. This work indicates that a high crystallinity and the face-on orientation of polymers could be obtained by forming alloy with two miscible donors, thus paving a way to largely enhance the PCE of OSCs by using the ternary blend strategy.

  4. 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

  5. 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.

  6. 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.

  7. 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

  8. 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

    2014-11-24

    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.

  9. 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

  10. Development of new two-dimensional small molecules based on benzodifuran for efficient organic solar cells.

    PubMed

    Du, Zhengkun; Chen, Yanhua; Chen, Weichao; Qiao, Shanlin; Wen, Shuguang; Liu, Qian; Zhu, Dangqiang; Sun, Mingliang; Yang, Renqiang

    2014-09-01

    A new organic small molecule, DCA3TBDF, with a 2D benzo[1,2-b:4,5-b']difuran (BDF) moiety as the central core and octyl cyanoacetate units as the end-capped blocks, was designed and synthesized for solution-processed bulk heterojunction solar cells. DCA3TBDF possesses good solubility in common organic solvents such as toluene, CH2Cl2, chlorobenzene, and CHCl3 and good thermal stability with an onset decomposition temperature with 5% weight-loss occurring at 361 °C. The DCA3TBDF thin film showed a broad absorption at λ=320-700 nm and high crystallinity. Small-molecule organic solar cells based on DCA3TBDF and [6,6]-phenyl-C61-butyric acid methyl ester demonstrated promising power conversion efficiency with a high fill factor under the illumination of AM 1.5G (100 mW cm(-2)). PMID:25044205

  11. 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.

  12. A tetraphenylethylene core-based 3D structure small molecular acceptor enabling efficient non-fullerene organic solar cells.

    PubMed

    Liu, Yuhang; Mu, Cheng; Jiang, Kui; Zhao, Jingbo; Li, Yunke; Zhang, Lu; Li, Zhengke; Lai, Joshua Yuk Lin; Hu, Huawei; Ma, Tingxuan; Hu, Rongrong; Yu, Demei; Huang, Xuhui; Tang, Ben Zhong; Yan, He

    2015-02-01

    A tetraphenylethylene core-based small molecular acceptor with a unique 3D molecular structure is developed. Bulk-heterojunction blend films with a small feature size (≈20 nm) are obtained, which lead to non-fullerene organic solar cells (OSCs) with 5.5% power conversion efficiency. The work provides a new molecular design approach to efficient non-fullerene OSCs based on 3D-structured small-molecule acceptors.

  13. 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

  14. Spacecraft/rover hybrids for the exploration of small Solar System bodies

    NASA Astrophysics Data System (ADS)

    Pavone, M.; Castillo-Rogez, J. C.; Nesnas, I. A. D.; Hoffman, J. A.; Strange, N. J.

    In this paper we present a mission architecture for the systematic and affordable in-situ exploration of small Solar System bodies (such as asteroids, comets, and Martian moons). At a general level, a mother spacecraft would deploy on the surface of a small body one, or several, spacecraft/rover hybrids, which are small (<; 5 kg, ≈ 15 Watts), multi-faceted robots enclosing three mutually orthogonal flywheels and surrounded by external spikes (in particular, there is no external propulsion). By accelerating/decelerating the flywheels and by exploiting the low gravity environment, the hybrids would be capable of performing both long excursions (by hopping) and short traverses to specific locations (through a sequence of controlled “ tumbles” ). 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. Specifically, in the first part of the paper we present preliminary models and laboratory experiments for the hybrids, first-order estimates for critical subsystems, and a preliminary study for synergistic mission operations. In the second part, we tailor our mission architecture to the exploration of Mars' moon Phobos. The mission aims at exploring Phobos' Stickney crater, whose spectral similarities with C-type asteroids and variety of terrain properties make it a particularly interesting exploration target to address both high-priority science for the Martian system and strategic knowledge gaps for the future human exploration of Mars.

  15. Comparison of defect formations in solar silicon growth from small random and large oriented seeds

    NASA Astrophysics Data System (ADS)

    Hsieh, C. C.; Wu, Y. C.; Lan, A.; Hsu, H. P.; Hsu, C.; Lan, C. W.

    2015-06-01

    The growth of solar silicon ingots by directional solidification using small random (chips) and large oriented (mono-chucks) seeds was carried out, and the defect formations using the ingots grown from the different seeds were compared. To have a similar growth environment, the seeds were placed side by side in the same crucible for the growth. It was observed that the silicon grown from small chips was more vulnerable to carbide precipitation, but the propagation of dislocation clusters was mitigated due to the existence of grain boundaries. On the other hand, the dislocation clusters could easily propagate in the mono-crystalline regime. As a result, as the ingot grew higher, more and larger dislocation clusters were found in the ingot from the large oriented seeds. Images from etched pits, photoluminescence, and minority lifetime were used for the comparison. Similar experiments were also carried in a commercial growth system, and the dislocation clusters in the growth from the small chip seeds were much less than that from the chuck seeds.

  16. 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

  17. 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.

  18. 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.

  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. Solar flare and pulsar detection with small balloon borne scintillator detector

    NASA Astrophysics Data System (ADS)

    Sarkar, Ritabrata; Chakrabarti, Sandip Kumar; Bhowmick, Debashis; Bhattacharya, Arnab

    2016-07-01

    We present radiation measurement data from the Sun and the Crab Pulsar using a very light weight payload comprising a scintillator detector from one of the ongoing missions carried out by Indian Centre for Space Physics, India. This is a unique observation in the sense that the payload containing the detector unit was carried off above the Earth atmosphere using small weather balloons in a very cost effective way and with severe weight constraints. In this Mission we have been able to observe two consecutive solar flares and radiation from the Crab pulsar when the payload was under 30 km altitude. We present a brief description of the mission strategy and the temporal and spectral analysis of the data from those sources.

  1. 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.

  2. 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

  3. From organic chemistry in small bodies of the solar system to low temperature chemistry in the universe. Preface.

    PubMed

    Levasseur-Regourd, A C; Raulin, F

    1995-01-01

    A COSPAR two days Symposium has been dedicated to "Prebiotic chemistry in Space" at the COSPAR Plenary Meeting, (Hamburg, Germany, July 1994). This Symposium was jointly organized by Commissions B (Space studies of the Earth-Moon system, planets and small bodies of the solar system) and F (Life sciences as related to space). Its goal was to review, from an interdisciplinary approach, our knowledge on organic and prebiotic chemistry in small bodies of the Solar System, and on low temperature chemistry and exobiology. The Symposium was sponsored by COSPAR and the IAU (session 1), ESA, NASA, and ISSOL (session 2).

  4. 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

  5. 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

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

    NASA Astrophysics Data System (ADS)

    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. N2 sorption analysis revealed high surface areas (203 m2 g-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 (VOC) of 0.74 V, short-circuit current density (JSC) of 3.83 mA cm-2 and an overall power conversion efficiency of 1.12% has been achieved.

  7. 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.

  8. 25th anniversary article: isoindigo-based polymers and small molecules for bulk heterojunction solar cells and field effect transistors.

    PubMed

    Wang, Ergang; Mammo, Wendimagegn; Andersson, Mats R

    2014-03-26

    Driven by the potential advantages and promising applications of organic solar cells, donor-acceptor (D-A) polymers have been intensively investigated in the past years. One of the strong electron-withdrawing groups that were widely used as acceptors for the construction of D-A polymers for applications in polymer solar cells and FETs is isoindigo. The isoindigo-based polymer solar cells have reached efficiencies up to ∼7% and hole mobilities as high as 3.62 cm(2) V(-1) s(-1) have been realized by FETs based on isoindigo polymers. Over one hundred isoindigo-based small molecules and polymers have been developed in only three years. This review is an attempt to summarize the structures and properties of the isoindigo-based polymers and small molecules that have been reported in the literature since their inception in 2010. Focus has been given only to the syntheses and device performances of those polymers and small molecules that were designed for use in solar cells and FETs. Attempt has been made to deduce structure-property relationships that would guide the design of isoindigo-based materials. It is expected that this review will present useful guidelines for the design of efficient isoindigo-based materials for applications in solar cells and FETs.

  9. 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

  10. 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

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. Reconstructing the size distribution of the small body population in the Solar System

    NASA Astrophysics Data System (ADS)

    Lambrechts, Michiel; Morbidelli, Alessandro

    2016-10-01

    The size distributions of the populations of small bodies in the solar system (the asteroid belt, the hot Kuiper belt and the cold Kuiper belt) show a striking similarity: they all show an elbow at a diameter of about D=100km. At D<100km, all size distributions have the same slope, dictated by collisional equilibrium. At D>100km, the slopes are different, the cold Kuiper belt having the steepest slope, while the hot Kuiper belt and the asteroid belt have progressively more shallow slopes. Moreover, the asteroid belt and hot Kuiper belt show a turnover to a shallow size distribution at sizes larger than D=300-500km. Johansen et al. (2015) explained the elbow and the transition to a steeper slope assuming that the original planetesimals had D<100km and that they grew further by the process of pebble accretion, the sweep up of small particles aided by gas drag. However, the origin of the differences between the slopes of the three populations remained unclear.Here we investigate the problem using a particle-in-a-box code, that treats collisional coagulation, fragmentation, dynamical stirring and damping, to which we have added growth by pebble accretion for objects with possibly eccentric and inclined orbits.We show that the size distribution above D=100km is set by a combination of planetesimal collisions and the sweeping up of pebbles. Thus, the final slopes are diagnostic of the collisionial rate and the initial total mass of the planetesimal population. The size distribution for the largest asteroids and hot Kuiper belt objects are consistent with growth dominated by the accretion of pebbles. The observed size distributions also places constraints on the dominant particle size, the level of midplane turbulence and nebular conditions at different orbital radii in the Solar nebula. Our findings hint that the asteroid belt largely formed close to the dissipation of the gas disc and that its final total mass was comparable to that of the Earth.

  16. Optimizing Decadal and Precursor Science on Small Solar System Bodies with Spacecraft/Rover Hybrids

    NASA Astrophysics Data System (ADS)

    Pavone, M.; Castillo, J. C.; Hoffman, J. A.; Nesnas, I. A.; Strange, N. J.

    2012-12-01

    In this paper we present a mission architecture for the systematic and affordable in-situ exploration of small Solar System bodies (such as asteroids, comets, and Martian moons). The proposed mission architecture stems from a paradigm-shifting approach whereby small bodies' low gravity is directly exploited in the design process, rather than being faced as a constraint. At a general level, a mother spacecraft (of the type of JPL's NEOSurveyor) would deploy on the surface of a small body one, or several, spacecraft/rover hybrids, which are small (<5Kg, ~10W), multi-faceted robots enclosing three mutually orthogonal flywheels and surrounded by external spikes (in particular, there is no external propulsion). By accelerating/decelerating the flywheels and by exploiting the low gravity environment, the hybrids would be capable of performing both long excursions (by hopping) and short traverses to specific locations (through a sequence of controlled "tumbles"). 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. A fundamental aspect of this mission architecture is that the responsibility for primary science would be shared between the mothership and the hybrids, in particular, the mothership would provide broad area coverage, while the hybrid would zoom in on specific areas and conduct in-situ measurements. Specifically, in the first part of the paper we discuss the scientific rationale behind the proposed mission architecture (including traceability matrices for both the mothership and the hybrids for a number of potential targets), we present preliminary models and laboratory experiments for the hybrids, we present first-order estimates for critical subsystems (e.g., communication, power, thermal) and a preliminary study for synergistic mission operations, and

  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 PAGES

    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. 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.

  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. 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.

  2. 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.

  3. 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

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

    PubMed

    Jin, Ruifa; Wang, Kai

    2015-08-27

    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.

  6. 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)

  7. 41 CFR 102-118.130 - Must my agency use a GBL for express, courier, or small package shipments?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... forth for use of a bill of lading for the Government. Any other non-conflicting applicable contracts or agreements between the TSP and an agency involving buying transportation services for Government...

  8. 41 CFR 102-118.130 - Must my agency use a GBL for express, courier, or small package shipments?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... forth for use of a bill of lading for the Government. Any other non-conflicting applicable contracts or agreements between the TSP and an agency involving buying transportation services for Government...

  9. 41 CFR 102-118.130 - Must my agency use a GBL for express, courier, or small package shipments?

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... forth for use of a bill of lading for the Government. Any other non-conflicting applicable contracts or agreements between the TSP and an agency involving buying transportation services for Government...

  10. 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

    ... forth for use of a bill of lading for the Government. Any other non-conflicting applicable contracts or agreements between the TSP and an agency involving buying transportation services for Government...

  11. 41 CFR 102-118.130 - Must my agency use a GBL for express, courier, or small package shipments?

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... forth for use of a bill of lading for the Government. Any other non-conflicting applicable contracts or agreements between the TSP and an agency involving buying transportation services for Government...

  12. 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

  13. 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.

  14. '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.

  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. DIRECT OBSERVATIONS OF MAGNETIC RECONNECTION OUTFLOW AND CME TRIGGERING IN A SMALL ERUPTING SOLAR PROMINENCE

    SciTech Connect

    Reeves, Katharine K.; McCauley, Patrick I.; Tian, Hui

    2015-07-01

    We examine a small prominence eruption that occurred on 2014 May 1 at 01:35 UT and was observed by the Interface Region Imaging Spectrometer (IRIS) and the Atmospheric Imaging Assembly (AIA) on the Solar Dynamics Observatory. Pre- and post-eruption images were taken by the X-ray Telescope (XRT) on Hinode. Pre-eruption, a dome-like structure exists above the prominence, as demarcated by coronal rain. As the eruption progresses, we find evidence for reconnection between the prominence magnetic field and the overlying field. Fast flows are seen in AIA and IRIS, indicating reconnection outflows. Plane-of-sky flows of 300 km s{sup −1} are observed in the AIA 171 A channel along a potentially reconnected field line. IRIS detects intermittent fast line of sight flows of 200 km s{sup −1} coincident with the AIA flows. Differential emission measure calculations show heating at the origin of the fast flows. Post-eruption XRT images show hot loops probably due to reconfiguration of magnetic fields during the eruption and subsequent heating of plasma in these loops. Although there is evidence for reconnection above the prominence during the eruption, high spatial resolution images from IRIS reveal potential reconnection sites below the prominence. A height–time analysis of the erupting prominence shows a slow initial rise with a velocity of 0.4 km s{sup −1} followed by a rapid acceleration with a final velocity of 250 km s{sup −1}. Brightenings in IRIS during the transition between these two phases indicate the eruption trigger for the fast part of the eruption is likely a tether-cutting mechanism rather than a break-out mechanism.

  17. Impact of the electron-transport layer on the performance of solution-processed small-molecule organic solar cells.

    PubMed

    Long, Guankui; Wan, Xiangjian; Kan, Bin; Hu, Zhicheng; Yang, Xuan; Zhang, Yi; Zhang, Mingtao; Wu, Hongbing; Huang, Fei; Su, Shijian; Cao, Yong; Chen, Yongsheng

    2014-08-01

    Although the performance of polymer solar cells has been improved significantly recently through careful optimization with different interlayers for the same materials, more improvement is needed in this respect for small-molecule-based solar cells, particularly for the electron-transport layers (ETLs). In this work, three different solution-processed ETLs, PFN, ZnO nanoparticles, and LiF, were investigated and compared in the performance of small-molecule-based devices, and power conversion efficiencies (PCEs) of 8.32, 7.30, and 7.38% were achieved, respectively. The mechanism for the ETL-induced enhancement has been studied, and different ETLs have a significantly different impact on the device performance. The clearly improved performance of PFN is attributed to the combination of reduced bimolecular recombination and increased effective photon absorption in the active layer.

  18. Impact of the electron-transport layer on the performance of solution-processed small-molecule organic solar cells.

    PubMed

    Long, Guankui; Wan, Xiangjian; Kan, Bin; Hu, Zhicheng; Yang, Xuan; Zhang, Yi; Zhang, Mingtao; Wu, Hongbing; Huang, Fei; Su, Shijian; Cao, Yong; Chen, Yongsheng

    2014-08-01

    Although the performance of polymer solar cells has been improved significantly recently through careful optimization with different interlayers for the same materials, more improvement is needed in this respect for small-molecule-based solar cells, particularly for the electron-transport layers (ETLs). In this work, three different solution-processed ETLs, PFN, ZnO nanoparticles, and LiF, were investigated and compared in the performance of small-molecule-based devices, and power conversion efficiencies (PCEs) of 8.32, 7.30, and 7.38% were achieved, respectively. The mechanism for the ETL-induced enhancement has been studied, and different ETLs have a significantly different impact on the device performance. The clearly improved performance of PFN is attributed to the combination of reduced bimolecular recombination and increased effective photon absorption in the active layer. PMID:24984949

  19. Interplay of solvent additive concentration and active layer thickness on the performance of small molecule solar cells.

    PubMed

    Love, John A; Collins, Samuel D; Nagao, Ikuhiro; Mukherjee, Subhrangsu; Ade, Harald; Bazan, Guillermo C; Nguyen, Thuc-Quyen

    2014-11-19

    A relationship between solvent additive concentration and active layer thickness in small-molecule solar cells is investigated. Specifically, the additive concentration must scale with the amount of semiconductor material and not as absolute concentration in solution. Devices with a wide range of active layers with thickness up to 200 nm can readily achieve efficiencies close to 6% when the right concentration of additive is used.

  20. Understanding the charge-transfer state and singlet exciton emission from solution-processed small-molecule organic solar cells.

    PubMed

    Ran, Niva A; Kuik, Martijn; Love, John A; Proctor, Christopher M; Nagao, Ikuhiro; Bazan, Guillermo C; Nguyen, Thuc-Quyen

    2014-11-19

    Electroluminescence (EL) from the charge-transfer state and singlet excitons is observed at low applied voltages from high-performing small-molecule bulk-heterojunction solar cells. Singlet emission from the blends emerges upon altering the processing conditions, such as thermal annealing and processing with a solvent additive, and correlates with improved photovoltaic performance. Low-temperature EL measurements are utilized to access the physics behind the singlet emission.

  1. Toward Additive-Free Small-Molecule Organic Solar Cells: Roles of the Donor Crystallization Pathway and Dynamics.

    PubMed

    Abdelsamie, Maged; Treat, Neil D; Zhao, Kui; McDowell, Caitlin; Burgers, Mark A; Li, Ruipeng; Smilgies, Detlef-M; Stingelin, Natalie; Bazan, Guillermo C; Amassian, Aram

    2015-12-01

    The ease with which small-molecule donors crystallize during solution processing is directly linked to the need for solvent additives. Donor molecules that get trapped in disordered (H1) or liquid crystalline (T1) mesophases require additive processing to promote crystallization, phase separation, and efficient light harvesting. A donor material (X2) that crystallizes directly from solution yields additive-free solar cells with an efficiency of 7.6%.

  2. 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

  3. 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.

  4. EVIDENCE FOR DEPARTURE FROM A POWER-LAW FLARE SIZE DISTRIBUTION FOR A SMALL SOLAR ACTIVE REGION

    SciTech Connect

    Wheatland, M. S.

    2010-02-20

    Active region 11029 was a small, highly flare-productive solar active region observed at a time of extremely low solar activity. The region produced only small flares: the largest of the >70 Geostationary Observational Environmental Satellite (GOES) events for the region has a peak 1-8 A flux of 2.2 x 10{sup -6} W m{sup -2} (GOES C2.2). The background-subtracted GOES peak-flux distribution suggests departure from power-law behavior above 10{sup -6} W m{sup -2}, and a Bayesian model comparison strongly favors a power-law plus rollover model for the distribution over a simple power-law model. The departure from the power law is attributed to this small active region having a finite amount of energy. The rate of flaring in the region varies with time, becoming very high for 2 days coinciding with the onset of an increase in complexity of the photospheric magnetic field. The observed waiting-time distribution for events is consistent with a piecewise-constant Poisson model. These results present challenges for models of flare statistics and of energy balance in solar active regions.

  5. 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…

  6. 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.

  7. Theoretical investigations on enhancing the performance of terminally diketopyrrolopyrrole-based small-molecular donors in organic solar cell applications.

    PubMed

    Liu, Xiaorui; Huang, Chengzhi; Shen, Wei; He, Rongxing; Li, Ming

    2016-01-01

    Diketopyrrolopyrrole (DPP)-based small molecules with acceptor-core-acceptor (A-core-A) type as donor materials have been used successfully in organic solar cells (OSC). In this work, based on the DPP-core-DPP type molecule SM1 consisting of a DPP unit as acceptor and benzene as the core, we replaced the benzene core with more electron-withdrawing groups in SM1 and further designed four new small-molecular donors (SM2-SM5) in order to improve the electrical properties, optical absorption and performance in OSC applications. The calculated results indicate that the designed small-molecular donors SM2-SM5 exhibit better performances in comparison with SM1, such as lower highest occupied molecular orbital (HOMO), narrower energy gap, larger absorption range, better electronic transfer between donor and acceptor and higher hole mobility. Moreover, the decreased HOMO levels and transition energy of small-molecular donors in OSC applications play an important role in the parameters of open-current voltage, fill factor and short-circuit current. Consequently, adjusting the electron-deficient ability of cores in DPP-core-DPP type small-molecular donors is an efficient approach that can be used to obtain high-efficiency DPP-based small-molecular donors for OSC applications. Graphical Abstract The designed small-molecules with good electronic and photophysical properties will act as a promising donor candidate for organic solar cell applications. Moreover, The decreased HOMO levels and transition energy of small-molecular donors in OSC applications play an important role in the parameters of open-current voltage, fill factor and short-circuit current.

  8. Design and integration of small RTPV generators with new millennium spacecraft for outer solar system

    NASA Astrophysics Data System (ADS)

    Schock, A.; Or, C.; Kumar, V.

    The National Aeronautics and Space Administration's recently inaugurated New Millennium program, with its emphasis on miniaturized spacecraft, has generated interest in a low-power (10-30 W), low-mass, high-efficiency RTPV (Radioisotope Thermophotovoltaic) power system. This led to a Department of Energy (DOE)-sponsored design study of such a system, which was assigned to OSC (formerly Fairchild) personnel, who have been conducting similar studies of a 75 W RTPV system for the Pluto Express Mission, with very encouraging results. The 75 W design employed two 250 W general purpose heat source (GPHS) modules that DOE had previously developed and safety-qualified for various space missions. These modules were too large for the small RTPVs described in this paper. To minimize the need for new development and safety verification studies, OSC generated derivative designs for 125 W and 62.5 W heat source modules containing identical fuel pellets, clads, impact shell and thermal insulation. OSC also generated a novel heat source support scheme to reduce the heat losses through the structural supports, and a new and much simpler radiator structure, eliminating the need for honeycombs and heat pipes. OSCs previous RTPV study had been based on the use of GaSb PV cells and spectrally selective IR filters that had been partially developed and characterized by Boeing (now EDTEK) personnel. They had supplied us with spectral data on filter reflectivities and cell quantum efficiencies. Two sets of data were furnished: one based on actual measurements made in 1993, and a more optimistic set based on projected performance improvements. Even the measured data set yielded significantly better system performance than present thermoelectric systems, but the projected data yielded much better system performance. Because of these encouraging results, OSC in the fall of 1994 initiated an experimental program at EDTEK to develop improved filters and cells, to demonstrate how much

  9. 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

  10. Modelling the Internal Structure and Evolution of Small Icy Bodies of the Solar System

    NASA Astrophysics Data System (ADS)

    Prialnik, D.

    2016-08-01

    The evolution of the internal structure of icy bodies of the solar system is simulated by numerical codes. The results are compared to available observations. The activity of comets and the differentiated structure of large bodies can be explained.

  11. Plasma-field Coupling at Small Length Scales in Solar Wind Near 1 AU

    NASA Astrophysics Data System (ADS)

    Livadiotis, G.; Desai, M. I.

    2016-10-01

    In collisionless plasmas such as the solar wind, the coupling between plasma constituents and the embedded magnetic field occurs on various temporal and spatial scales, and is primarily responsible for the transfer of energy between waves and particles. Recently, it was shown that the transfer of energy between solar wind plasma particles and waves is governed by a new and unique relationship: the ratio between the magnetosonic energy and the plasma frequency is constant, E ms/ω pl ˜ ℏ*. This paper examines the variability and substantial departure of this ratio from ℏ* observed at ˜1 au, which is caused by a dispersion of fast magnetosonic (FMS) waves. In contrast to the efficiently transferred energy in the fast solar wind, the lower efficiency of the slow solar wind can be caused by this dispersion, whose relation and characteristics are derived and studied. In summary, we show that (i) the ratio E ms/ω pl transitions continuously from the slow to the fast solar wind, tending toward the constant ℏ* (ii) the transition is more efficient for larger thermal, Alfvén, or FMS speeds; (iii) the fast solar wind is almost dispersionless, characterized by quasi-constant values of the FMS speed, while the slow wind is subject to dispersion that is less effective for larger wind or magnetosonic speeds; and (iv) the constant ℏ* is estimated with the best known precision, ℏ* ≈ (1.160 ± 0.083) × 10-22 Js.

  12. 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.

  13. 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.

  14. Morphological effects on the small-molecule-based solution-processed organic solar cells.

    PubMed

    Lee, Dong-Chan; Brownell, Lacie V; Yan, Liang; You, Wei

    2014-09-24

    We report a proof-of-concept study on solution-processed organic solar cells (OSCs) based on [6,6]-phenyl-C61-butyric acid methyl ester (PC61BM) and structurally compact donor molecules which have dithiophene-phenazine-dithiophene (TH-P) and dithiophene-quinoxaline-dithiophene (TH-Q) configurations with decyloxy and methyl side groups, respectively. These molecules formed one-dimensional fibers through self-assembly via weak nonbonding interactions such as π-π and van der Waals interactions even during a fast solvent removal process such as spin-casting. Photophysical and thermal properties of the new donor molecules were characterized with UV-vis absorption and fluorescence spectroscopy, differential scanning calorimetry, and thermogravimetric analysis. The electrochemical data determined experimentally were correlated well with theoretical evaluations. The fibers from the two donor molecules showed distinct morphological differences, allowing for in-depth investigations into their influence on the OSC performance. A continuous three-dimensional network of endless one-dimensional nanofibers, with a width of 300-400 nm, were formed from TH-P regardless of the presence of PC61BM, affording spontaneous nanoscale phase separation that facilitates a large donor/acceptor interfacial area. Bulk (BHJ) and planar heterojunctions (PHJ) from TH-P/PC61BM showed a power conversion efficiency (PCE) of 0.38% and 0.30%, respectively, under optimum device conditions. Post thermal annealing led to the increased domain size and a major decrease in Jsc. Meanwhile, shorter, more rigid needles with a large thickness variation were formed from TH-Q. A continuous network of TH-Q was obtained by spin-coating only in the presence of PC61BM, and the PCE of TH-Q/PC61BM BHJ was found to be 0.36%. However, the PHJ showed poor device performance due to TH-Q's inability to form a continuous film by spin-coating. The present study suggests a basic molecular architecture to drive one

  15. 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

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. 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

  2. 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.

  3. 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.

  4. 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.

  5. 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...

  6. Solar-thermal experimental projects on the Spanish Plataforma Solar

    NASA Astrophysics Data System (ADS)

    Grasse, W.

    1981-11-01

    The Plataforma Solar with an area of 1,000,000 sq m is located in Spain at a distance of approximately 50 km from the Mediterranean. In May 1979, nine members of the International Energy Agency (IEA) decided to support the construction of Small Solar Power Systems (SSPS). The countries involved include West Germany, the U.S., Spain, and Italy. The SSPS are to demonstrate the operational feasibility of solar technologies which have been mainly developed in Germany and the U.S. In addition, data are to be obtained regarding the relative competitive position of two different operational concepts for SSPS. The concepts are related to the central receiver system (solar tower) and the distributed collector system. Attention is also given to the Spanish solar power station CESA-1 and the German-Spanish technology program GAST, which is to explore the technological limits of solar-energy systems.

  7. 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.

  8. 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

  9. 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.

  10. 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.

  11. 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

  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. 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.

  15. 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.

  16. [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.

  17. Back-contacted and small form factor GaAs solar cell.

    SciTech Connect

    Clews, Peggy Jane; Wanlass, Mark W.; Sanchez, Carlos A.; Pluym, Tammy; Cruz-Campa, Jose Luis; Okandan, Murat; Gupta, Vipin P.; Nielson, Gregory N.; Resnick, Paul James

    2010-07-01

    We present a newly developed microsystem enabled, back-contacted, shade-free GaAs solar cell. Using microsystem tools, we created sturdy 3 {micro}m thick devices with lateral dimensions of 250 {micro}m, 500 {micro}m, 1 mm, and 2 mm. The fabrication procedure and the results of characterization tests are discussed. The highest efficiency cell had a lateral size of 500 {micro}m and a conversion efficiency of 10%, open circuit voltage of 0.9 V and a current density of 14.9 mA/cm{sup 2} under one-sun illumination.

  18. 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.

  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. Design principles for high efficiency small-grain polysilicon solar cells, with supporting experimental studies

    NASA Technical Reports Server (NTRS)

    Lindholm, F. A.; Neugroschel, A.; Sah, C. T.

    1982-01-01

    Design principles suggested here aim toward high conversion efficiency (greater than 15 percent) in polysilicon cells. The principles seek to decrease the liabilities of both intragranular and grain-boundary-surface defects. The advantages of a phosphorus atom concentration gradient in a thin (less than 50 microns) base of a p(+)/n(x)/n(+) drift-field solar cell, which produces favorable gradients in chemical potential, minority-carrier mobility and diffusivity, and recombination lifetime (via phosphorus gettering) are suggested. The degrading effects of grain boundaries are reduced by these three gradients and by substituting atoms (P, H, F or Li) for vacancies on the grain-boundary surface. From recent experiments comes support for the benefits of P diffusion down grain boundaries and, for quasi-grain-boundary-free and related structures. New analytic solutions for the n(x)-base include the effect of a power-law dependence between P concentration and lifetime. These provide an upper-bound estimate on the open circuit voltage. Finite-difference numerical solutions of the six Shockley equations furnish complete information about all solar-cell parameters and add insight concerning design.

  1. 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.

  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 ALFVÉN WAVES

    SciTech Connect

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

    2015-10-10

    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{sup −1.67}) to the dispersion range (k{sup −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. 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.

  5. 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

  6. 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.

  7. 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.

  8. 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.

  9. Cataloging and Characterizing the Small Bodies of the Solar System with LSST

    NASA Astrophysics Data System (ADS)

    Chesley, Steven R.; Brown, M. E.; Durech, J.; Harris, A. W.; Ivezić, Ž.; Jones, R. L.; Knežević, Z.; LSST Solar System Science Collaboration

    2009-01-01

    LSST will address key planetary science objectives identified as priorities by diverse national science panels. This is due to LSST's Deep-Wide-Fast survey implementation, which is ideal for detecting faint solar system objects. Specifically, the proposed cadence includes two back-to-back 15 second exposures that will detect sources as faint as r=24.7. By revisiting each 9.6 square degree field within roughly 30 minutes, the system will find about 4000 moving objects per field near the ecliptic and cover the entire observable sky 4-5 times per lunation. LSST will produce an instantly public multicolor dataset of exceptional accuracy, with, for example, 50 mas astrometry and 70 millimag photometry at r=23.5. The ten-year survey will discover approximately 15,000 Potentially Hazardous Asteroids larger than 140m, approaching the George Brown Near-Earth Object Survey goal set by Congress of cataloging 90% of such objects. It will also find millions of main belt asteroids and up to 100,000 transneptunian objects, as well as thousands of objects in between, such as comets, Trojans, Centaurs and irregular satellites of the outer planets. The orbit, size and color distribution derived for various classes of object will allow new tests and constraints for theories on the formation and evolution of the solar system. Detection of very distant objects will permit new insights into the nature of the Oort cloud. The sparse photometry from LSST detections will be sufficient to enable spin state and shape models to be developed for tens of thousands of asteroids. By revealing perturbations on smaller asteroids, the accurate astrometry will allow estimates of the mass of hundreds of main belt asteroids. By pushing to ever smaller sizes, derivation of proper elements for main belt asteroids will greatly enlarge existing asteroid families, and precise multi-color photometry will facilitate further division by correlating color with dynamical class and history.

  10. 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.

  11. 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.

  12. 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}.

  13. 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.

  14. The effects of different atmospheric conditions on device stability of organic small-molecule solar cells under constant illumination

    NASA Astrophysics Data System (ADS)

    Karak, S.; Pradhan, S.; Dhar, A.

    2011-09-01

    A systematic study is presented on various effects of different environmental conditions on stability and degradation of small-molecule organic solar cells under continuous simulated solar radiation. Devices were fabricated based on heterojunctions with pentacene and copper phthalocyanine as donor, and [6,6]-phenyl C61 butyric acid methyl ester as acceptor materials. Seven different operating conditions were employed to investigate their degradation stability. Three simultaneous mechanisms were found to be largely responsible for device degradation: (i) photo-oxidation of active materials in the presence of light and oxygen that results in a drop of photocarrier generation and electrical transport properties of the cells, (ii) morphology instability with UV annealing reducing the charge transport within the devices and (iii) bubble formation in the vicinity of the electrodes with moisture absorption, affecting charge collection efficiency of the cells. Significant improvement in device stability was found by careful choice of operating conditions and proper encapsulation. Device lifetime enhanced by almost 100 times under UV filtered vacuum environment or with polydimethylsiloxane encapsulation as compared to a cell operated under ambient conditions without encapsulation.

  15. 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.

  16. 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.

  17. 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.

  18. 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

  19. Radiation forces on small particles in the Solar System: A re-consideration

    NASA Astrophysics Data System (ADS)

    Burns, Joseph A.; Lamy, Philippe L.; Soter, Steven

    2014-04-01

    We respond to Klačka et al. (Klačka, J., Petržala, J., Pástor, P., Kómar, L. [2014]. Icarus, this issue, http://dx.doi.org/10.1016/j.icarus.2012.06.044.), who have criticized many previous derivations of the acceleration experienced by a spherical interplanetary particle owing to the Sun’s radiation. Much of their criticism arises from differences in semantics and notation as well as effects that are unimportant at Solar System speeds. Accordingly, in the appropriate limiting cases, most published expressions for the radiation forces, such as that found in Burns et al. (Burns, J.A., Lamy, P.L., Soter, S. [1979]. Icarus 40 1-48), are correct and duplicate the results of Klačka et al. (Klačka, J., Petržala, J., Pástor, P., Kómar, L. [2014]. Icarus, this issue, http://dx.doi.org/10.1016/j.icarus.2012.06.044).

  20. 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.

  1. Integration of small run-of-river and solar power: The hydrological regime prediction/assessment accuracy

    NASA Astrophysics Data System (ADS)

    Francois, Baptiste; Creutin, Jean-Dominique; Hingray, Benoit; Zoccatelli, Davide

    2014-05-01

    The possibility to achieved a high integration of climate related energies (i.e. run-of-river-, wind- and solar- energies) depends on the possibility to balance the potentially large deviations between the related intermittent productions and the variable demand using storage facilities such as water storage in accumulation dams. These deviations depend obviously on how energy sources co-fluctuate in time among themselves and with the demand as well. Balancing hydropower system design as well as their operational planning requires the estimation of these co-fluctuations, resulting from both, space and time weather structures/patterns and watershed features (e.g. area, altitude range, geological basement …). The co-fluctuations between intermittent energy sources can be estimated from observed time series when available or from time series obtained from simulation models when not or when different contexts have to be considered (e.g. climate change and/or intermittent energy development). The simulation models were classically developed and evaluated for the prediction of each energy source individually. The ability of the models to simulate relevant levels of co-fluctuations is however to our knowledge not really considered. This issue is however critical and should also require thorough attention. This work focuses on run-of-river and solar- power interaction assessment. The study area is located in Italy where run-of-river power plants, mainly located on small river tributaries, represent almost 43 % of the hydropower production with only 27 % of the installed hydro-capacity (in 2011). Solar power generation is available from observed time series at different locations over the region but there is no systematic measurement of water discharges over the considered river tributaries and discharges have to be reconstituted from simulations. The absence of discharge measures makes also impossible to calibrate hydrological model at each power plant location. We thus

  2. Discovery of Peculiar Periodic Spectral Modulations in a Small Fraction of Solar-type Stars

    NASA Astrophysics Data System (ADS)

    Borra, Ermanno F.; Trottier, Eric

    2016-11-01

    A Fourier transform analysis of 2.5 million spectra in the Sloan Digital Sky Survey was carried out to detect periodic spectral modulations. Signals having the same period were found in only 234 stars overwhelmingly in the F2 to K1 spectral range. The signals cannot be caused by instrumental or data analysis effects because they are present in only a very small fraction of stars within a narrow spectral range and because signal-to-noise ratio considerations predict that the signal should mostly be detected in the brightest objects, while this is not the case. We consider several possibilities, such as rotational transitions in molecules, rapid pulsations, Fourier transform of spectral lines, and signals generated by extraterrestrial intelligence (ETI). They cannot be generated by molecules or rapid pulsations. It is highly unlikely that they come from the Fourier transform of spectral lines because too many strong lines located at nearly periodic frequencies are needed. Finally, we consider the possibility, predicted in a previous published paper, that the signals are caused by light pulses generated by ETI to makes us aware of their existence. We find that the detected signals have exactly the shape of an ETI signal predicted in the previous publication and are therefore in agreement with this hypothesis. The fact that they are only found in a very small fraction of stars within a narrow spectral range centered near the spectral type of the Sun is also in agreement with the ETI hypothesis. However, at this stage, this hypothesis needs to be confirmed with further work. Although unlikely, there is also a possibility that the signals are due to highly peculiar chemical compositions in a small fraction of galactic halo stars.

  3. 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.

  4. Preliminary study of a small beam-down solar tower on sub-Saharan countries

    NASA Astrophysics Data System (ADS)

    Ndiaye, Ahmadou; Thiam, Ababacar; Mbow, Cheikh; Stouffs, Pascal; Azilinon, Dorothé

    2016-05-01

    In this present work, a small Beam Down power plant is studied in the Sahel region. The preconfigured system is a field of 78 heliostats and a hyperboloid sectioned with a length rhyp = 11.72 m. The simulation made with the software SolTrace shows an efficiency of the field up to 89%. Temperatures from 675.37 K to 809.55 K are achieved and the power intercepted at the receiver input are equal to 96.57 kW, 124.53 9 kW and 98.90 kW respectively at 9 am, 1: 06 pm and 4 pm.

  5. 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.

  6. 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.

  7. OBSERVATION OF KINK INSTABILITY DURING SMALL B5.0 SOLAR FLARE ON 2007 JUNE 4

    SciTech Connect

    Srivastava, A. K.; Kumar, Pankaj; Zaqarashvili, T. V.; Khodachenko, M. L. E-mail: pkumar@aries.res.i E-mail: maxim.khodachenko@oeaw.ac.a

    2010-05-20

    Using multi-wavelength observations of SOHO/MDI, SOT-Hinode/blue-continuum (4504 A), G band (4305 A), Ca II H (3968 A), and TRACE 171 A, we present the observational signature of a highly twisted magnetic loop in AR 10960 during the period 04:43 UT-04:52 UT on 2007 June 4. SOT-Hinode/blue-continuum (4504 A) observations show that penumbral filaments of positive polarity sunspot have counterclockwise twist, which may be caused by the clockwise rotation of the spot umbrae. The coronal loop, whose one footpoint is anchored in this sunspot, shows strong right-handed twist in chromospheric SOT-Hinode/Ca II H (3968 A) and coronal TRACE 171 A images. The length and the radius of the loop are L {approx} 80 Mm and a {approx} 4.0 Mm, respectively. The distance between neighboring turns of magnetic field lines (i.e., pitch) is estimated as {approx}10 Mm. The total twist angle, {Phi} {approx} 12{pi} (estimated for the homogeneous distribution of the twist along the loop), is much larger than the Kruskal-Shafranov instability criterion. We detected clear double structure of the loop top during 04:47 UT-04:51 UT on TRACE 171 A images, which is consistent with simulated kink instability in curved coronal loops. We suggest that the kink instability of this twisted magnetic loop triggered a B5.0 class solar flare, which occurred between 04:40 UT and 04:51 UT in this active region.

  8. 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.

  9. 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.

  10. 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.

  11. 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

  12. 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

  13. 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)

  14. 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.

  15. 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.

  16. Small molecular donors for organic solar cells obtained by simple and clean synthesis.

    PubMed

    Demeter, Dora; Mohamed, Salma; Diac, Andreea; Grosu, Ion; Roncali, Jean

    2014-04-01

    A small donor-acceptor molecule is synthesized in a two-step procedure involving reaction of N,N-diphenylhydrazine on 2,5-diformylthiophene and Knoevenagel condensation. Results of UV/Vis absorption spectroscopy and cyclic voltammetry show that replacement of the phenyl ring bridge of a reference compound 2 by an azo group produces a slight red-shift of λmax, an enhancement of the molecular absorption coefficient, and a decrease of the energy level of the frontier orbitals. A preliminary evaluation of the potentialities of compound 1 as donor material in a basic bilayer planar heterojunction cell of 28 mm(2) active area using C60 as acceptor gave a short-circuit current density of 6.32 mA cm(-2) and a power conversion efficiency of 2.07 %.

  17. Liquid water in small solar system bodies, and the possibilities for evolution of life

    NASA Astrophysics Data System (ADS)

    Sparks, D. W.; Tice, M. M.; Farrell, L.; McGary, R. S.

    2008-12-01

    Much attention has been focused on the few large satellites of Jupiter and Saturn that have evidence of interior layers of liquid water, and the possibility that they may be suitable habitats for life. For life to evolve in these regions, they would have to, at a minimum, produce the necessary chemical constituents to provide energy for building organic matter, be protected from temperature extremes and radiation, and last long enough for evolution to progress. The type of organisms that could form in such habitats could be similar to those that evolved in the pre-photosynthetic, anoxic early Earth. The probability of extra-terrestrial life evolving in our solar system would increase greatly if such suitable habitats had been more common. We examine the possibilities for suitable habitats in the more numerous set of moderate-sized (< 1000 km in diameter) ice-rich planetesimals that may populate the Asteroid Belt and Kuiper Belt. We modeled the thermal evolution of 200-1000 km planetesimals, assuming cold accretion of undifferentiated bodies comprised of a mixture of chondritic rock and water ice. The heat sources for these planetesimals are short- and long-lived radioactive isotopes, and the latent heat from hydration reactions. We vary the planetesimals initial size, surface temperature, ice/rock ratio and the 26Al content (which is very sensitive to the timing of accretion). Each modeled planetesimal undergoes a pulse of radioactive heating, followed by slow cooling. Some water from the melting ice phase migrates upward to form an "internal ocean" layer beneath a still frozen crust, while some water reacts with the remaining rock to form a hydrated silicate (serpentinized) core. In warmer planetesimals, these hydrated silicates can break-down, and a second phase of water production and migration occurs. If the frozen rock/ice crust becomes too thin, we assume that crustal overturn will result in loss of any underlying liquid. Many models produce liquid water

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. 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

  3. 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.

  4. 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.

  5. 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

  6. Resolving the Fan-spine Reconnection Geometry of a Small-scale Chromospheric Jet Event with the New Solar Telescope

    NASA Astrophysics Data System (ADS)

    Zeng, Zhicheng; Chen, Bin; Ji, Haisheng; Goode, Philip R.; Cao, Wenda

    2016-03-01

    Jets are ubiquitously present in both quiet and active regions on the Sun. They are widely believed to be driven by magnetic reconnection. A fan-spine structure has been frequently reported in some coronal jets and flares, and has been regarded as a signature of ongoing magnetic reconnection in a topology consisting of a magnetic null connected by a fan-like separatrix surface and a spine. However, for small-scale chromospheric jets, clear evidence of such structures is rather rare, although it has been implied in earlier works that showed an inverted-Y-shaped feature. Here we report high-resolution (0.″16) observations of a small-scale chromospheric jet obtained by the New Solar Telescope (NST) using 10830 Å filtergrams. Bi-directional flows were observed across the separatrix regions in the 10830 Å images, suggesting that the jet was produced due to magnetic reconnection. At the base of the jet, a fan-spine structure was clearly resolved by the NST, including the spine and the fan-like surface, as well as the loops before and after the reconnection. A major part of this fan-spine structure, with the exception of its bright footpoints and part of the base arc, was invisible in the extreme ultraviolet and soft X-ray images (observed by the Atmosphere Imaging Assembly and the X-Ray Telescope, respectively), indicating that the reconnection occurred in the upper chromosphere. Our observations suggest that the evolution of this chromospheric jet is consistent with a two-step reconnection scenario proposed by Török et al.

  7. Development of a Small-spin-axis Controller and Its Application to a Solar Sail Subpayload Satellite

    NASA Astrophysics Data System (ADS)

    Saiki, Takanao; Nakaya, Koji; Yamamoto, Takayuki; Tsuda, Yuichi; Mori, Osamu; Kawaguchi, Jun'ichiro

    The instruments and actuators in the attitude control system of small spacecraft are restricted in weight and space, and need to be reduced in weight and size. The rhumb line control strategy is one of the most popular schemes in reorientation of spin-stabilized spacecraft, since it requires only a spin sun sensor and a single axis reaction control system. By being combined with active nutation control, rhumb line control can reorient the spin axis of the spacecraft to any direction. To verify the control strategy, we manufactured an attitude controller and demonstration experiments were conducted using a motion table at ISAS/JAXA. This paper reviews the configuration of the controller and the outlines of the experiments, and evaluates the control performance. The same type of controller was installed in the Solar Sail Subpayload Satellite (SSSAT) launched in September 2006. An attitude control experiment in orbit was not conducted because of trouble with the satellite, but new control logic for the SSSAT was implemented for the attitude controller. This paper also reviews the control logic of the SSSAT.

  8. 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

  9. 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.

  10. 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

  11. 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. ​

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. STEREO Observations of Small Transients in the Solar Wind at 1 AU (2007-2014) and Comparison with Near - Earth Results from Wind (1995 - 2014)

    NASA Astrophysics Data System (ADS)

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

    2015-12-01

    The occurrence frequency of small transients (STs) in the solar wind increases dramatically during solar activity minimum. With observations from the Wind spacecraft we could observe STs near Earth over a period of 20 years. Now we also have measurements by the STEREO spacecraft, which observe at 1 AU as they separate from Earth by 22.5 degrees per year. Hence we have an unprecedented opportunity to study the STs at the far side of the Sun at 1 AU, and examine their distribution over solar cycle activity (~ 8 years). We show their properties per year at STEREO, and compare them with Wind's results. The occurrence of STs is found to be anti-correlated with that of ICMEs (STs are frequently observed in the solar minimum while the ICMEs are fewer). We then model some flux-rope type STs by non-force free models, both analytical and numerical ones. Most of the fitting results show that the cross-section of the small flux ropes tends to be elliptical. Finally we show how their orientations are distributed at 1 AU.

  17. 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.

  18. Improvement of bulk heterojunction organic solar cells based on PTB7:PC61BM with small amounts of P3HT

    NASA Astrophysics Data System (ADS)

    Ohori, Yurina; Fujii, Shunjiro; Kataura, Hiromichi; Nishioka, Yasushiro

    2015-04-01

    The effect of a small amount of poly(3-hexylthiophene) (P3HT) additive on the performance of bulk heterojunction (BHJ) organic solar cells based on poly[[4,8-bis[(2-ethylhexyl)oxy]benzo[1,2-b:4,5-b‧]dithiophene-2,6-diyl][3-fluoro-2-[(2-ethylhexyl)carbonyl]thieno[3,4-b]thiophenediyl

  19. 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.

  20. 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.

  1. 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.

  2. 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

  3. 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

  4. 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.

  5. 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.

  6. 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

  7. 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.

  8. 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.

  9. 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.

  10. 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 (...

  11. 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

  12. 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.

  13. Triisopropylsilylethynyl-functionalized dibenzo[def,mno]chrysene: a solution-processed small molecule for bulk heterojunction solar cells

    SciTech Connect

    Zhang, Lei; Walker, Bright; Liu, Feng; Colella, Nicholas S.; Mannsfeld, Stefan C. B.; Watkins, James J.; Nguyen, Thuc-Quyen; Briseno, Alejandro L.

    2011-12-22

    This communication reports the synthesis of a new polycyclic aromatic hydrocarbon and its unique packing motif. This molecule is shown to be an efficient electron donor in organic bulk heterojunction solar cells, exhibiting a power conversion efficiency of [similar]2.0%.

  14. 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

  15. 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.

  16. 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.

  17. 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

  18. 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.

  19. Unsymmetrical Donor-Acceptor-Acceptor-π-Donor Type Benzothiadiazole-Based Small Molecule for a Solution Processed Bulk Heterojunction Organic Solar Cell.

    PubMed

    Gautam, Prabhat; Misra, Rajneesh; Siddiqui, Shahbaz A; Sharma, Ganesh D

    2015-05-20

    A D1-A-A'-π-D2 type (D = donor; A = acceptor) unsymmetrical small molecule denoted as BTD3 containing different end group donor moieties has been designed and synthesized for use as a donor in the solution processable bulk heterojunction (BHJ) solar cell. The BTD3 exhibits a low HOMO-LUMO gap of 1.68 eV and deeper HOMO energy level (-5.5 eV). Its LUMO energy level (-3.65 eV) is compatible with the LUMO level of PC71BM to facilitate the electron transfer from BTD3 to PC71BM in the BHJ solar cell. The solution processed BHJ solar cell with optimized BTD3:PC71BM active layer processed with THF solvent exhibited a PCE of 3.15% with Jsc = 7.45 mA/cm(2), Voc = 0.94 V, and FF = 0.45. Moreover, the device with optimized concentration of 3 vol. % 1-chloronaphthalene (CN) additive, i.e., CN/THF, showed significant enhancement in PCE up to 4.61% (Jsc = 9.48 mA/cm(2), Voc = 0.90 V, and FF = 0.54). The improvement in the PCE has been attributed to the appropriate nanoscale phase separation morphology, balance charge transport, and enhancement in the light harvesting ability of the active layer.

  20. 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.

  1. SMALL-SCALE MAGNETIC ISLANDS IN THE SOLAR WIND AND THEIR ROLE IN PARTICLE ACCELERATION. I. DYNAMICS OF MAGNETIC ISLANDS NEAR THE HELIOSPHERIC CURRENT SHEET

    SciTech Connect

    Khabarova, O.; Zank, G. P.; Li, G.; Roux, J. A. le; Webb, G. M.; Dosch, A.; Malandraki, O. E.

    2015-08-01

    Increases of ion fluxes in the keV–MeV range are sometimes observed near the heliospheric current sheet (HCS) during periods when other sources are absent. These resemble solar energetic particle events, but the events are weaker and apparently local. Conventional explanations based on either shock acceleration of charged particles or particle acceleration due to magnetic reconnection at interplanetary current sheets (CSs) are not persuasive. We suggest instead that recurrent magnetic reconnection occurs at the HCS and smaller CSs in the solar wind, a consequence of which is particle energization by the dynamically evolving secondary CSs and magnetic islands. The effectiveness of the trapping and acceleration process associated with magnetic islands depends in part on the topology of the HCS. We show that the HCS possesses ripples superimposed on the large-scale flat or wavy structure. We conjecture that the ripples can efficiently confine plasma and provide tokamak-like conditions that are favorable for the appearance of small-scale magnetic islands that merge and/or contract. Particles trapped in the vicinity of merging islands and experiencing multiple small-scale reconnection events are accelerated by the induced electric field and experience first-order Fermi acceleration in contracting magnetic islands according to the transport theory of Zank et al. We present multi-spacecraft observations of magnetic island merging and particle energization in the absence of other sources, providing support for theory and simulations that show particle energization by reconnection related processes of magnetic island merging and contraction.

  2. Small-scale Magnetic Islands in the Solar Wind and Their Role in Particle Acceleration. I. Dynamics of Magnetic Islands Near the Heliospheric Current Sheet

    NASA Astrophysics Data System (ADS)

    Khabarova, O.; Zank, G. P.; Li, G.; le Roux, J. A.; Webb, G. M.; Dosch, A.; Malandraki, O. E.

    2015-08-01

    Increases of ion fluxes in the keV-MeV range are sometimes observed near the heliospheric current sheet (HCS) during periods when other sources are absent. These resemble solar energetic particle events, but the events are weaker and apparently local. Conventional explanations based on either shock acceleration of charged particles or particle acceleration due to magnetic reconnection at interplanetary current sheets (CSs) are not persuasive. We suggest instead that recurrent magnetic reconnection occurs at the HCS and smaller CSs in the solar wind, a consequence of which is particle energization by the dynamically evolving secondary CSs and magnetic islands. The effectiveness of the trapping and acceleration process associated with magnetic islands depends in part on the topology of the HCS. We show that the HCS possesses ripples superimposed on the large-scale flat or wavy structure. We conjecture that the ripples can efficiently confine plasma and provide tokamak-like conditions that are favorable for the appearance of small-scale magnetic islands that merge and/or contract. Particles trapped in the vicinity of merging islands and experiencing multiple small-scale reconnection events are accelerated by the induced electric field and experience first-order Fermi acceleration in contracting magnetic islands according to the transport theory of Zank et al. We present multi-spacecraft observations of magnetic island merging and particle energization in the absence of other sources, providing support for theory and simulations that show particle energization by reconnection related processes of magnetic island merging and contraction.

  3. 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

  4. 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.

  5. 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.

  6. 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

  7. 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

  8. 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.

  9. 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.

  10. 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

  11. 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.

  12. 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

  13. 48 CFR 15.604 - Agency points of contact.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... of unsolicited proposals at least the following information: (1) Definition (see 2.101) and content... agency: upcoming solicitations; Broad Agency Announcements; Small Business Innovation Research...

  14. A portable electrospinning apparatus based on a small solar cell and a hand generator: design, performance and application

    NASA Astrophysics Data System (ADS)

    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

    2015-12-01

    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.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. Electronic supplementary information (ESI) available. See DOI: 10.1039/c5nr06858d

  15. SMALL-SCALE HEATING EVENTS IN THE SOLAR ATMOSPHERE. I. IDENTIFICATION, SELECTION, AND IMPLICATIONS FOR CORONAL HEATING

    SciTech Connect

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

    2015-11-01

    We present a comprehensive method to analyze small-scale heating events in detail in a 3D magnetohydrodynamics simulation for quiet-Sun conditions. The method determines the number, volume, and some general geometric properties of the small-scale heating events at different instants in a simulation with a volume of 16 × 8 × 16 Mm{sup 3}, spanning from the top of the convection zone to the corona. We found that there are about 10{sup 4} small-scale heating events at any instant above the simulated area of 128 Mm{sup 2}. They occur mainly at heights between 1.5 and 3.0 Mm. We determine the average value of their projected vertical extent, which ranges from 375 to 519 km over time, and we show that height, volume, and energy distribution of the events at any instant resemble power laws. Finally, we demonstrate that larger heating structures are a combination of much smaller heating events and that small-scale heating events dissipate enough energy to maintain the coronal energetic balance at any instant.

  16. 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.

  17. 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.

  18. 76 FR 54747 - Proposed Agency Information Collection

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-02

    ... project financing. In order to direct strategic investments toward reducing those costs, the Agency... financing options, and planning and zoning issues as they relate to rooftop solar PV installations....

  19. 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.

  20. 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.

  1. 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.

  2. Peculiarity of two thermodynamically-stable morphologies and their impact on the efficiency of small molecule bulk heterojunction solar cells

    DOE PAGES

    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

    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.

  4. 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

  5. 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.

  6. 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.

  7. Miniature personal uv solar dosimeter: small light-powered meter measures accumulated radiation in the ultraviolet or other selected regions. NTIS tech note

    SciTech Connect

    Not Available

    1981-11-01

    This citation summarizes a one-page announcement of technology available for utilization. A miniature integrating light meter originally developed for use in space has many other possible applications. Small enough to be worn unobtrusively, it can measure accurately the radiation dose accumulated for a few minutes or over a period of weeks. It can measure total light or selected wave bands, such as UV or IR. The primary practical advantages of the dosimeter are its potentially low cost, small size, accuracy, and adaptability to specific wave-band measurements. Medical applications suggested include as a research tool for studies of skin cancer, vitamin D production, and jaundice and for possible use in conjuction with the treatments involving Sunlight exposure. It could be further used to measure integrated Sunlight for solar-energy design, for agriculture and meteorology, and to study and monitor the stability of materials and environmental and occupatinal lighting. The meter uses a planar-diffused silicon photovoltaic detector as a sensor and a commercially available electrochemical coulometer to measure light accumulation....FOR ADDITIONAL INFORMATION: Contact: Inquiries concerning nonexclusive or exclusive license for its commercial development should be addressed to the Patent Counsel, Langley Research Center, Hampton, VA. Refer To LAR-12469.

  8. 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

  9. Interaction between Metal Impurities and Small-Angle Grain Boundaries on Recombination Properties in Multicrystalline Silicon for Solar Cells

    NASA Astrophysics Data System (ADS)

    Sameshima, Takashi; Miyazaki, Naoto; Tsuchiya, Yuki; Hashiguchi, Hiroki; Tachibana, Tomihisa; Kojima, Takuto; Ohshita, Yoshio; Arafune, Koji; Ogura, Atsushi

    2012-04-01

    Recombination properties at small-angle grain boundaries (SA-GBs) in multicrystalline silicon were evaluated. After Fe contamination, the electron-beam-induced current (EBIC) contrast at most SA-GBs became stronger, especially at >1.5°. After Al gettering, EBIC contrast of most <1.5° SA-GBs became as weak as before contamination. Then, some EBIC contrast of >1.5° SA-GBs showed comparable contrast before gettering. In addition, there were SA-GBs which have different recombination properties even with the same misorientation angle. Between these SA-GBs, there were differences in the rotation axis, boundary direction, and existence of defects. The associativity of metals might be affected by the existence of defects caused by these differences.

  10. 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.

  11. 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.

  12. 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.

  13. Mercury Sample Return using Solar Sails

    NASA Astrophysics Data System (ADS)

    Young, Roy; Montgomery, E.; Adams, C.

    2006-12-01

    Over the previous three years NASA’s In-Space Propulsion Technology (ISPT) Program has matured solar sail technology from laboratory components to full systems, demonstrated in as relevant a space environment as could be simulated on the ground. Solar sail propulsion uses sunlight to propel vehicles through space by reflecting solar photons from a large sails made of a lightweight, reflective material. With photonic pressure providing continuous thrust, sailcraft can conduct missions not available with conventional propulsion: • high-inclination plane changes • flyby or rendezvous missions to outer solar system objects • non-Keplarian orbits (e.g. above the pole of a planet) • hovering indefinitely near a Lagrange point in space To illustrate the capabilities of solar sails, the results of an European Space Agency Mercury Sample Return study using solar sails is described and compared with a mission using conventional propulsion. A conventional Mercury sample return mission requires significant launch mass due to the large Δv required for the outbound and return trips, and the large mass of a planetary lander and ascent vehicle. Solar sailing can reduce mass by delivering the lander to a low, orbit close to the terminator and providing the Δv for the return flight. The mission concept calls for a 275 m sail to deliver a lander, cruise stage and science payload to a Sun-synchronous orbit at Mercury in 2.85 years. The lander acquires samples, and conducts limited surface exploration. An ascent vehicle delivers a small vehicle containing the samples for transfer to the solar sail. The solar sail then spirals back to Earth in 1 year. Solar sailing reduces launch mass by 60% and trip time by 40%, relative to conventional mission concepts. Results of technology development activities sponsored by the ISPT Program will be provided to demonstrate the level of technology readiness for such missions.

  14. 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.

  15. 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.

  16. 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.

  17. 48 CFR 15.604 - Agency points of contact.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... agency: upcoming solicitations; Broad Agency Announcements; Small Business Innovation Research programs; Small Business Technology Transfer Research programs; Program Research and Development Announcements; or... of unsolicited proposals at least the following information: (1) Definition (see 2.101) and...

  18. 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

  19. High open-circuit voltage small-molecule p-DTS(FBTTh 2 )2.ICBA bulk heterojunction solar cells – morphology, excited-state dynamics, and photovoltaic performance

    DOE PAGES

    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

  20. 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.

  1. 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.

  2. 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...

  3. 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.

  4. 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...

  5. 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...

  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. 78 FR 48537 - Small Business Innovation Research and Small Business Technology Transfer Programs...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-08

    ... ADMINISTRATION Small Business Innovation Research and Small Business Technology Transfer Programs... Administration (SBA) is publishing the Small Business Innovation Research (SBIR) and Small Business Technology Transfer (STTR) program Commercialization Benchmark for the 11 participating agencies for public...

  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. Small Business Administration Semiannual Regulatory Agenda

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-04-26

    ... businesses. Timetable: Action Date FR Cite NPRM 08/00/10 Regulatory Flexibility Analysis Required: Yes Agency... Manufacturing Assistance Act of 2004 (Reauthorization Act) to regulate Small Business Lending Companies (SBLCs... Part XVI Small Business Administration Semiannual Regulatory Agenda ] SMALL...

  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. 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.

  13. 48 CFR 19.1004 - Participating agencies.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 48 Federal Acquisition Regulations System 1 2010-10-01 2010-10-01 false Participating agencies. 19.1004 Section 19.1004 Federal Acquisition Regulations System FEDERAL ACQUISITION REGULATION SOCIOECONOMIC PROGRAMS SMALL BUSINESS PROGRAMS Small Business Competitiveness Demonstration Program...

  14. 78 FR 4968 - Privacy Act of 1974, Computer Matching Program-U.S. Small Business Administration and U.S...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-01-23

    .... Department of Homeland Security, Federal Emergency Management Agency AGENCY: U.S. Small Business.... Department of Homeland Security, Federal Emergency Management Agency. SUMMARY: The U.S. Small Business... From the Federal Register Online via the Government Publishing Office SMALL...

  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. 13 CFR 105.403 - Designated Agency Ethics Officials.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 13 Business Credit and Assistance 1 2013-01-01 2013-01-01 false Designated Agency Ethics Officials. 105.403 Section 105.403 Business Credit and Assistance SMALL BUSINESS ADMINISTRATION STANDARDS OF... Agency Ethics Officials. The Designated Agency Ethics Official and Alternates administer the program...

  17. 13 CFR 105.403 - Designated Agency Ethics Officials.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 13 Business Credit and Assistance 1 2012-01-01 2012-01-01 false Designated Agency Ethics Officials. 105.403 Section 105.403 Business Credit and Assistance SMALL BUSINESS ADMINISTRATION STANDARDS OF... Agency Ethics Officials. The Designated Agency Ethics Official and Alternates administer the program...

  18. 13 CFR 105.403 - Designated Agency Ethics Officials.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 13 Business Credit and Assistance 1 2011-01-01 2011-01-01 false Designated Agency Ethics Officials. 105.403 Section 105.403 Business Credit and Assistance SMALL BUSINESS ADMINISTRATION STANDARDS OF... Agency Ethics Officials. The Designated Agency Ethics Official and Alternates administer the program...

  19. 13 CFR 105.403 - Designated Agency Ethics Officials.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 13 Business Credit and Assistance 1 2014-01-01 2014-01-01 false Designated Agency Ethics Officials. 105.403 Section 105.403 Business Credit and Assistance SMALL BUSINESS ADMINISTRATION STANDARDS OF... Agency Ethics Officials. The Designated Agency Ethics Official and Alternates administer the program...

  20. 13 CFR 105.403 - Designated Agency Ethics Officials.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 13 Business Credit and Assistance 1 2010-01-01 2010-01-01 false Designated Agency Ethics Officials. 105.403 Section 105.403 Business Credit and Assistance SMALL BUSINESS ADMINISTRATION STANDARDS OF... Agency Ethics Officials. The Designated Agency Ethics Official and Alternates administer the program...

  1. 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…

  2. Chalcogenophene comonomer comparison in small band gap diketopyrrolopyrrole-based conjugated polymers for high-performing field-effect transistors and organic solar cells.

    PubMed

    Ashraf, Raja Shahid; Meager, Iain; Nikolka, Mark; Kirkus, Mindaugas; Planells, Miquel; Schroeder, Bob C; Holliday, Sarah; Hurhangee, Michael; Nielsen, Christian B; Sirringhaus, Henning; McCulloch, Iain

    2015-01-28

    The design, synthesis, and characterization of a series of diketopyrrolopyrrole-based copolymers with different chalcogenophene comonomers (thiophene, selenophene, and tellurophene) for use in field-effect transistors and organic photovoltaic devices are reported. The effect of the heteroatom substitution on the optical, electrochemical, and photovoltaic properties and charge carrier mobilities of these polymers is discussed. The results indicate that by increasing the size of the chalcogen atom (S < Se < Te), polymer band gaps are narrowed mainly due to LUMO energy level stabilization. In addition, the larger heteroatomic size also increases intermolecular heteroatom-heteroatom interactions facilitating the formation of polymer aggregates leading to enhanced field-effect mobilities of 1.6 cm(2)/(V s). Bulk heterojunction solar cells based on the chalcogenophene polymer series blended with fullerene derivatives show good photovoltaic properties, with power conversion efficiencies ranging from 7.1-8.8%. A high photoresponse in the near-infrared (NIR) region with excellent photocurrents above 20 mA cm(-2) was achieved for all polymers, making these highly efficient low band gap polymers promising candidates for use in tandem solar cells. PMID:25547347

  3. 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,...

  4. 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.

  5. 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...

  6. 48 CFR 19.804-2 - Agency offering.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 48 Federal Acquisition Regulations System 1 2010-10-01 2010-10-01 false Agency offering. 19.804-2 Section 19.804-2 Federal Acquisition Regulations System FEDERAL ACQUISITION REGULATION SOCIOECONOMIC PROGRAMS SMALL BUSINESS PROGRAMS Contracting With the Small Business Administration (the 8(a) Program) 19.804-2 Agency offering. (a) After...

  7. 48 CFR 219.804-1 - Agency evaluation.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 48 Federal Acquisition Regulations System 3 2010-10-01 2010-10-01 false Agency evaluation. 219.804..., DEPARTMENT OF DEFENSE SOCIOECONOMIC PROGRAMS SMALL BUSINESS PROGRAMS Contracting With the Small Business Administration (The 8(a) Program) 219.804-1 Agency evaluation. (f) The 8(a) firms should be offered...

  8. 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

  9. 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

  10. Agency and intervention.

    PubMed

    Roskies, Adina L

    2015-09-19

    Novel ways to intervene on brain function raise questions about agency and responsibility. Here, I discuss whether direct brain interventions, and in particular, deep brain stimulation, pose a threat to agency in individual cases, or to our general conceptualization of what it is to be a responsible agent. While I do not currently see evidence that these interventions constitute a global challenge to our concept of agency, they do have the potential to diminish agency in individuals. I consider whether the lack of evidence for a global challenge ratifies our folk conceptions, or is a necessary consequence of them. In closing, I propose that our theoretical understanding of agency and our therapeutic approaches could be improved with a more nuanced, multidimensional view of agency. PMID:26240430

  11. Agency and intervention

    PubMed Central

    Roskies, Adina L.

    2015-01-01

    Novel ways to intervene on brain function raise questions about agency and responsibility. Here, I discuss whether direct brain interventions, and in particular, deep brain stimulation, pose a threat to agency in individual cases, or to our general conceptualization of what it is to be a responsible agent. While I do not currently see evidence that these interventions constitute a global challenge to our concept of agency, they do have the potential to diminish agency in individuals. I consider whether the lack of evidence for a global challenge ratifies our folk conceptions, or is a necessary consequence of them. In closing, I propose that our theoretical understanding of agency and our therapeutic approaches could be improved with a more nuanced, multidimensional view of agency. PMID:26240430

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. Austin`s solar explorer program

    SciTech Connect

    Libby, L.

    1997-12-31

    The City of Austin Electric Utility Department`s Solar Explorer Program will give customers the option to help support the installation of large community scale photovoltaic (or PV) systems. Through Solar Explorer, the City of Austin is joining with the US Department of Energy, the Utility Photo Voltaic Group and other utilities nationwide to make solar electricity more affordable. Residential and small commercial customers become Solar Explorers by volunteering to pay a small premium each month to help fund the installation and maintenance of a small section of a PV power plant. Large commercial customers, organizations and schools can participate by marketing Solar Explorer to their employees, members and customers. If enough Solar Explorers are recruited, a large community scale solar PV plant can be installed on the commercial customer`s roof, parking garage or parking lot. A total of 257 kilowatts (kW) of PV systems can be installed in this initial phase of Solar Explorer.

  17. Negotiating with Subscription Agencies.

    ERIC Educational Resources Information Center

    McQueen, Judy; Basch, N. Bernard

    1991-01-01

    This first in a two-part series on how librarians can negotiate services and prices with subscription agencies focuses on how vendors operate. Factors that influence agency costs, revenues, and service charges are described, including economies of scale, discounts from publishers, and prepayment and cash flow. (seven references) (LRW)

  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. 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

  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. Solar energy

    NASA Astrophysics Data System (ADS)

    Rapp, D.

    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.

  2. 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.

  3. Solar Systems

    NASA Technical Reports Server (NTRS)

    1979-01-01

    The solar collectors shown are elements of domestic solar hot water systems produced by Solar One Ltd., Virginia Beach, Virginia. Design of these systems benefited from technical expertise provided Solar One by NASA's Langley Research Center. The company obtained a NASA technical support package describing the d e sign and operation of solar heating equipment in NASA's Tech House, a demonstration project in which aerospace and commercial building technology are combined in an energy- efficient home. Solar One received further assistance through personal contact with Langley solar experts. The company reports that the technical information provided by NASA influenced Solar One's panel design, its selection of a long-life panel coating which increases solar collection efficiency, and the method adopted for protecting solar collectors from freezing conditions.

  4. 34 CFR 84.645 - Federal agency or agency.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 34 Education 1 2010-07-01 2010-07-01 false Federal agency or agency. 84.645 Section 84.645 Education Office of the Secretary, Department of Education GOVERNMENTWIDE REQUIREMENTS FOR DRUG-FREE WORKPLACE (FINANCIAL ASSISTANCE) Definitions § 84.645 Federal agency or agency. Federal agency or...

  5. 28 CFR 83.645 - Federal agency or agency.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 28 Judicial Administration 2 2010-07-01 2010-07-01 false Federal agency or agency. 83.645 Section 83.645 Judicial Administration DEPARTMENT OF JUSTICE (CONTINUED) GOVERNMENT-WIDE REQUIREMENTS FOR DRUG-FREE WORKPLACE (GRANTS) Definitions § 83.645 Federal agency or agency. Federal agency or...

  6. Solar Variability and Climate

    NASA Astrophysics Data System (ADS)

    Haigh, Joanna D.

    Solar radiation is the fundamental energy source for the atmosphere and the global average equilibrium temperature of the Earth is determined by a balance between the energy acquired by the solar radiation absorbed and the energy lost to space by the emission of heat radiation. The interaction of this radiation with the climate system is complex but it is clear that any change in total solar irradiance (TSI) has the potential to influence climate. In the past, although many papers were written on relationships between sunspot numbers and the weather, the topic of solar influences on climate was often disregarded by meteorologists. This was due to a combination of factors of which the key was the lack of any robust measurements indicating that solar radiation did indeed vary. There was also mistrust of the statistical validity of the evidence and, importantly, no established scientific mechanisms whereby the apparent changes in the Sun might induce detectable signals near the Earth's surface. Another influence was a desire by the meteorological profession to distance itself from the Astrometeorology movement popular in the 19th century (anderson1999). Nowadays, with improved measurements of solar and climate parameters, evidence for an influence of solar variability on the climate of the lower atmosphere has emerged from the noise. This article provides a brief review of the observational evidence and an outline of the mechanisms whereby rather small changes in solar radiation may induce detectable signals near the Earth's surface is not possible to review here all potential mechanisms for solar-climate links. What is presented offers, necessarily, a personal perspective but, of the areas that are not covered, two may be pertinent: the effects of solar energetic particles on stratospheric composition (see e.g. jackman et al. 2005) and the possible influence of galactic cosmic rays on clouds through ionisation processes (see Marsh, this volume).

  7. Roles of small, acid-soluble spore proteins and core water content in survival of Bacillus subtilis spores exposed to environmental solar UV radiation.

    PubMed

    Moeller, Ralf; Setlow, Peter; Reitz, Günther; Nicholson, Wayne L

    2009-08-01

    Spores of Bacillus subtilis contain a number of small, acid-soluble spore proteins (SASP) which comprise up to 20% of total spore core protein. The multiple alpha/beta-type SASP have been shown to confer resistance to UV radiation, heat, peroxides, and other sporicidal treatments. In this study, SASP-defective mutants of B. subtilis and spores deficient in dacB, a mutation leading to an increased core water content, were used to study the relative contributions of SASP and increased core water content to spore resistance to germicidal 254-nm and simulated environmental UV exposure (280 to 400 nm, 290 to 400 nm, and 320 to 400 nm). Spores of strains carrying mutations in sspA, sspB, and both sspA and sspB (lacking the major SASP-alpha and/or SASP-beta) were significantly more sensitive to 254-nm and all polychromatic UV exposures, whereas the UV resistance of spores of the sspE strain (lacking SASP-gamma) was essentially identical to that of the wild type. Spores of the dacB-defective strain were as resistant to 254-nm UV-C radiation as wild-type spores. However, spores of the dacB strain were significantly more sensitive than wild-type spores to environmental UV treatments of >280 nm. Air-dried spores of the dacB mutant strain had a significantly higher water content than air-dried wild-type spores. Our results indicate that alpha/beta-type SASP and decreased spore core water content play an essential role in spore resistance to environmentally relevant UV wavelengths whereas SASP-gamma does not.

  8. 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…

  9. 75 FR 35847 - Privacy Act of 1974, Computer Matching Program-U.S. Small Business Administration and U.S...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-23

    .... Department of Homeland Security, Federal Emergency Management Agency AGENCY: Small Business Administration... Homeland Security, Federal Emergency Management Agency. SUMMARY: The U.S. Small Business Administration... Files (September 24, 2009, 74 FR 48763) system of records through its National Emergency...

  10. 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.

  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 Collectors

    NASA Technical Reports Server (NTRS)

    1980-01-01

    Solar Energy's solar panels are collectors for a solar energy system which provides heating for a drive-in bank in Akron, OH. Collectors were designed and manufactured by Solar Energy Products, a firm established by three former NASA employees. Company President, Frank Rom, an example of a personnel-type technology transfer, was a Research Director at Lewis Research Center, which conducts extensive solar heating and cooling research, including development and testing of high-efficiency flat-plate collectors. Rom acquired solar energy expertise which helped the company develop two types of collectors, one for use in domestic/commercial heating systems and the other for drying grain.

  13. First Solar Power Sail Demonstration by IKAROS

    NASA Astrophysics Data System (ADS)

    Mori, Osamu; Sawada, Hirotaka; Funase, Ryu; Morimoto, Mutsuko; Endo, Tatsuya; Yamamoto, Takayuki; Tsuda, Yuichi; Kawakatsu, Yasuhiro; Kawaguchi, Jun'ichiro; Miyazaki, Yasuyuki; Shirasawa, Yoji; Demonstration Team; Solar Sail Working Group, Ikaros

    The Japan Aerospace Exploration Agency (JAXA) will make the world's first solar power sail craft demonstration of photon propulsion and thin film solar power generation during its interplanetary cruise by IKAROS (Interplanetary Kite-craft Accelerated by Radiation Of the Sun). The spacecraft deploys and spans a membrane of 20 meters in diameter taking the advantage of the spin centrifugal force. The spacecraft weighs approximately 310kg, launched together with the agency's Venus Climate Orbiter, AKATSUKI in May 2010. This will be the first actual solar sail flying an interplanetary voyage.

  14. 77 FR 22550 - Approval and Promulgation of Air Quality Implementation Plans; Illinois; Small Container...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-16

    ... Container Exemption From VOC Coating Rules AGENCY: Environmental Protection Agency (EPA). ACTION: Proposed... of amendments to the Illinois Administrative Code by adding ] a ``small container exemption''...

  15. 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

    ... Solar Inc., Lathrop Wells Solar Facility, Amargosa Valley, Nye County, NV AGENCY: Bureau of Land... the Abengoa Solar Inc., Lathrop Wells Solar Facility by any of the following methods: E-mail: lwse_EIS... Project Manager, Attn: Abengoa Lathrop Wells Solar Facility, 4701 North Torrey Pines Drive, Las...

  16. Solar-heating system

    NASA Technical Reports Server (NTRS)

    1979-01-01

    Report describes solar modular domestic-hot-water and space-heating system intended for use in small single family dwelling where roof-mounted collectors are not feasible. Contents include design, performance, and hardware specifications for assembly, installation, operation, and maintenance of system.

  17. 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 ...

  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. 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.

  20. 77 FR 23267 - Agency Information Collection Activities; Proposed Collection; Comment Request; Guidance for...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-18

    ... HUMAN SERVICES Food and Drug Administration Agency Information Collection Activities; Proposed... Medical Device User Fee Small Business Qualification and Certification AGENCY: Food and Drug Administration, HHS. ACTION: Notice. SUMMARY: The Food and Drug Administration (FDA) is announcing an...

  1. 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.

  2. Buying Solar.

    ERIC Educational Resources Information Center

    Dawson, Joe

    Presented are guidelines for buying solar systems for the individual consumer. This is intended to help the consumer reduce many of the risks associated with the purchase of solar systems, particularly the risks of fraud and deception. Engineering terms associated with solar technology are presented and described to enable the consumer to discuss…

  3. 12 CFR 411.200 - Agency and legislative liaison.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... presentations by persons seeking awards from an agency pursuant to the provisions of the Small Business Act, as... 12 Banks and Banking 4 2010-01-01 2010-01-01 false Agency and legislative liaison. 411.200 Section 411.200 Banks and Banking EXPORT-IMPORT BANK OF THE UNITED STATES NEW RESTRICTIONS ON...

  4. 15 CFR 28.200 - Agency and legislative liaison.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 15 Commerce and Foreign Trade 1 2010-01-01 2010-01-01 false Agency and legislative liaison. 28.200 Section 28.200 Commerce and Foreign Trade Office of the Secretary of Commerce NEW RESTRICTIONS ON LOBBYING... presentations by persons seeking awards from an agency pursuant to the provisions of the Small Business Act,...

  5. Solar wind and magnetosphere interactions

    NASA Technical Reports Server (NTRS)

    Russell, C. T.; Allen, J. H.; Cauffman, D. P.; Feynman, J.; Greenstadt, E. W.; Holzer, R. E.; Kaye, S. M.; Slavin, J. A.; Manka, R. H.; Rostoker, G.

    1979-01-01

    The relationship between the magnetosphere and the solar wind is addressed. It is noted that this interface determines how much of the solar plasma and field energy is transferred to the Earth's environment, and that this coupling not only varies in time, responding to major solar disturbances, but also to small changes in solar wind conditions and interplanetary field directions. It is recommended that the conditions of the solar wind and interplanetary medium be continuously monitored, as well as the state of the magnetosphere. Other recommendations include further study of the geomagnetic tail, tests of Pc 3,4 magnetic pulsations as diagnostics of the solar wind, and tests of kilometric radiation as a remote monitor of the auroral electrojet.

  6. 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...

  7. 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,...

  8. 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,...

  9. 76 FR 52377 - National Small Business Development Center Advisory Board

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-22

    ... Update. --International Expansion. --Use of Social Media. --Member Roundtable. FOR FURTHER INFORMATION... From the Federal Register Online via the Government Publishing Office SMALL BUSINESS ADMINISTRATION National Small Business Development Center Advisory Board AGENCY: U.S. Small...

  10. 48 CFR 970.1907 - The Small Business Subcontracting Program.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... AGENCY SUPPLEMENTARY REGULATIONS DOE MANAGEMENT AND OPERATING CONTRACTS Small Business Programs 970.1907 The Small Business Subcontracting Program. ... 48 Federal Acquisition Regulations System 5 2011-10-01 2011-10-01 false The Small...

  11. Soiling of building envelope surfaces and its effect on solar reflectance. Part I: Analysis of roofing product databases

    DOE PAGES

    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

  12. 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

  13. 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…

  14. 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...

  15. 2 CFR 182.645 - Federal agency or agency.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 182.645 Grants and Agreements Office of Management and Budget Guidance for Grants and Agreements OFFICE OF MANAGEMENT AND BUDGET GOVERNMENTWIDE GUIDANCE FOR GRANTS AND AGREEMENTS NATIONAL POLICY... Federal agency or agency. Federal agency or agency means any United States executive department,...

  16. 2 CFR 182.645 - Federal agency or agency.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 182.645 Grants and Agreements Office of Management and Budget Guidance for Grants and Agreements OFFICE OF MANAGEMENT AND BUDGET GOVERNMENTWIDE GUIDANCE FOR GRANTS AND AGREEMENTS NATIONAL POLICY... Federal agency or agency. Federal agency or agency means any United States executive department,...

  17. Solar nutrinos

    NASA Technical Reports Server (NTRS)

    Bahcall, J. N.

    1981-01-01

    The topics covered include: an overview of the subject of solar neutrinos, a brief summary of the theory of stellar evolution, a description of the main sources of solar neutrinos, a brief summary of the results of the Brookhaven C1-37 experiment, an anaysis of the principal solar neutrino experiments, and a discussion of how solar neutrino experiments can be used to detect the collapse of stars in the Galaxy. A description of how the Ga-71 experiment can be used to decide whether the origin of the present discrepancy between theory and observation lies in conventional solar models or conventional physics is presented.

  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.

  20. Solar Optics

    SciTech Connect

    Rozsnyai, B.F.

    2000-10-04

    Solar opacities are presented from the center of the Sun to the photosphere. The temperatures, densities and hydrogen mass fractions are taken from the standard solar model. For the heavy element abundances the Grevesse mixture is used. In the solar interior photoabsorption is dominated by free-free absorption and they compare two sets of opacities based on two different models for the inverse bremsstrahlung. The radiative luminosities calculated from the two sets of opacities are compared with those predicted by previous models of the standard solar model and also with the known luminosity of the Sun. pressures, specific heats and the speed of sound in the solar plasma are also presented.

  1. 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

  2. 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.

  3. 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.

  4. 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.

  5. 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.…

  6. 77 FR 13121 - Solar Energy Industries Association: Notice of Petition for Rulemaking

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-05

    ... Energy Regulatory Commission Solar Energy Industries Association: Notice of Petition for Rulemaking Take notice that on February 16, 2012, Solar Energy Industries Association, pursuant to sections 205 and 206... procedures \\1\\ for solar electric generation. \\1\\ Standardization of Small Generator...

  7. 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…

  8. 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…

  9. 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…

  10. 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.

  11. 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.

  12. 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

  13. Solar greenhouse

    SciTech Connect

    Baldwin, R.E.

    1980-04-01

    A solar greenhouse is disclosed wherein plants are grown and utilized as collectors to absorb solar radiation and produce heat laden humidified air through the process of evapotranspiration. This humidified air is then further heated by solar energy. Energy is then extracted from the humidified air by cooling the air and condensing the water vapor within the air. The extracted heat can then be stored and utilized as required to heat the greenhouse and plants.

  14. 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.

  15. 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.

  16. 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)

  17. 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

  18. 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.

  19. 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.

  20. SMEX-Lite Modular Solar Array Architecture

    NASA Technical Reports Server (NTRS)

    Lyons, John W.; Day, John (Technical Monitor)

    2002-01-01

    The NASA Small Explorer (SMEX) missions have typically had three years between mission definition and launch. This short schedule has posed significant challenges with respect to solar array design and procurement. Typically, the solar panel geometry is frozen prior to going out with a procurement. However, with the SMEX schedule, it has been virtually impossible to freeze the geometry in time to avoid scheduling problems with integrating the solar panels to the spacecraft. A modular solar array architecture was developed to alleviate this problem. This approach involves procuring sufficient modules for multiple missions and assembling the modules onto a solar array framework that is unique to each mission. The modular approach removes the solar array from the critical path of the SMEX integration and testing schedule. It also reduces the cost per unit area of the solar arrays and facilitates the inclusion of experiments involving new solar cell or panel technologies in the SMEX missions.

  1. 2 CFR 902.645 - Federal agency or agency.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... ENERGY Reserved REQUIREMENTS FOR DRUG-FREE WORKPLACE (FINANCIAL ASSISTANCE) Definitions § 902.645 Federal agency or agency. Department of Energy means the U.S. Department of Energy (DOE), including the...

  2. 2 CFR 182.645 - Federal agency or agency.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 182.645 Grants and Agreements Office of Management and Budget Guidance for Grants and Agreements OFFICE OF MANAGEMENT AND BUDGET GOVERNMENTWIDE GUIDANCE FOR GRANTS AND AGREEMENTS GOVERNMENTWIDE.... Federal agency or agency means any United States executive department, military department,...

  3. Workplan and Annex: Solar Resource Knowledge Management

    SciTech Connect

    Renne, D.

    2005-01-01

    ''Solar Resource Knowledge Management'' will be a new task under the International Energy Agency's Solar Heating and Cooling Programme. The task development has involved researchers from Germany, France, Switzerland, Spain, Portugal, Italy, Canada, the U.S. that have been engaged in the use of satellite imagery to develop solar resource maps and datasets around the world. The task will address three major areas: (1) ''Benchmarking'' of satellite-based solar resource methods so that resource information derived from approaches developed in one country or based on a specific satellite can be quantitatively intercompared with methods from other countries using different satellites, as well as with ground data; (2) Data archiving and dissemination procedures, especially focusing on access to the data by end users; and (3) basic R&D for improving the reliability and usability of the data, and for examining new types of products important to the solar industry, such as solar resource forecasts.

  4. Solar Sail Propulsion for Interplanetary Cubesats

    NASA Technical Reports Server (NTRS)

    Johnson, Les; Sobey, Alex; Sykes, Kevin

    2015-01-01

    NASA is developing two small satellite missions as part of the Advanced Exploration Systems (AES) Program, both of which will use a solar sail to enable their scientific objectives. Solar sails use sunlight to propel vehicles through space by reflecting solar photons from a large, mirror-like sail made of a lightweight, highly reflective material. This continuous photon pressure provides propellantless thrust, allowing for very high (Delta)V maneuvers on long-duration, deep space exploration. Since reflected light produces thrust, solar sails require no onboard propellant. Solar sail technology is rapidly maturing for space propulsion applications within NASA and around the world.

  5. Discovering the Solar System

    NASA Astrophysics Data System (ADS)

    Jones, Barrie W.

    1999-04-01

    Discovering the Solar System Barrie W. Jones The Open University, Milton Keynes, UK Discovering the Solar System is a comprehensive, up-to-date account of the Solar System and of the ways in which the various bodies have been investigated and modelled. The approach is thematic, with sequences of chapters on the interiors of planetary bodies, on their surfaces, and on their atmospheres. Within each sequence there is a chapter on general principles and processes followed by one or two chapters on specific bodies. There is also an introductory chapter, a chapter on the origin of the Solar System, and a chapter on asteroids, comets and meteorites. Liberally illustrated with diagrams, black and white photographs and colour plates, Discovering the Solar System also features: * tables of essential data * question and answers within the text * end of section review questions with answers and comments Discovering the Solar System is essential reading for all undergraduate students for whom astronomy or planetary science are components of their degrees, and for those at a more advanced level approaching the subject for the first time. It will also be of great interest to non-specialists with a keen interest in astronomy. A small amount of scientific knowledge is assumed plus familiarity with basic algebra and graphs. There is no calculus. Praise for this book includes: ".certainly qualifies as an authoritative text. The author clearly has an encyclopedic knowledge of the subject." Meteorics and Planetary Science ".liberally doused with relevant graphs, tables, and black and white figures of good quality." EOS, Transactions of the American Geophysical Union ".one of the best books on the Solar System I have seen. The general accuracy and quality of the content is excellent." Journal of the British Astronomical Association

  6. SMART Solar Sail

    NASA Technical Reports Server (NTRS)

    Curtis, Steven A.

    2005-01-01

    A report summarizes the design concept of a super miniaturized autonomous reconfigurable technology (SMART) solar sail a proposed deployable, fully autonomous solar sail for use in very fine station keeping of a spacecraft. The SMART solar sail would include a reflective film stretched among nodes of a SMART space frame made partly of nanotubule struts. A microelectromechanical system (MEMS) at each vertex of the frame would spool and unspool nanotubule struts between itself and neighboring nodes to vary the shape of the frame. The MEMSs would be linked, either wirelessly or by thin wires within the struts, to an evolvable neural software system (ENSS) that would control the MEMSs to reconfigure the sail as needed. The solar sail would be highly deformable from an initially highly compressed configuration, yet also capable of enabling very fine maneuvering of the spacecraft by means of small sail-surface deformations. The SMART Solar Sail would be connected to the main body of the spacecraft by a SMART multi-tether structure, which would include MEMS actuators like those of the frame plus tethers in the form of longer versions of the struts in the frame.

  7. Superactive regions in solar cycle 24

    NASA Astrophysics Data System (ADS)

    Wang, Jingxiu; Chen, Anqin

    2015-08-01

    Solar super active regions (SARs) are characterized by huge sunspot area, strong thermal and non-thermal radiation, severe activity events and obvious decrease of total solar irradiance during their central meridian passage (Chen et al. 2011). They are more close to the star spots observed in integrated stellar radiation. In last 5 solar cycles, the SARs occupied less than 5% of total solar active regions, but hosted more than 40% of X class X-ray flares (or equivalently, major solar flares). With available vector-magnetograph observations, we quantitatively described the SARs in solar cycles 22-23 with four parameters, which were deduced from vector magnetic fields, and suggested a composite vector field Index Icom (Chen and Wang 2012). The SARs with very strong flare activity all have Icom > 1. Comparing with solar cycles 21-23, the level of solar activity in current solar cycle is very low. So far, there are only 5 SARs and 44 X class flares. The monthly smoothed TSI decreased sharply by 0.09% from the maximum of solar cycle 23 to the minima between solar cycle 23 and 24. In this contribution, we present new studies on SARs in solar cycle 24. The SARs in solar cycle 24 have relatively small flare index and relatively small vector field index Icom comparing with the SARs in solar cycles 22 and 23. There is a clearly linear relationship between the flare index and the composite vector field index (Chen and Wang 2015). The emphasis of this contribution is put on the similarity and different behaviors of vector magnetic fields of the SARs in the current solar cycle and the previous ones. We try to get a satisfactory account for the general characteristics and relatively low level of solar flare activity in cycle 24.

  8. 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...

  9. 38 CFR 48.645 - Federal agency or agency.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 2 2010-07-01 2010-07-01 false Federal agency or agency. 48.645 Section 48.645 Pensions, Bonuses, and Veterans' Relief DEPARTMENT OF VETERANS AFFAIRS... executive branch (including the Executive Office of the President), or any independent regulatory agency....

  10. 22 CFR 208.910 - Agency.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...) Definitions § 208.910 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...

  11. 22 CFR 208.910 - Agency.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...) Definitions § 208.910 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...

  12. 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...

  13. 31 CFR 19.910 - Agency.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... (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...

  14. 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...

  15. 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...

  16. 22 CFR 1508.910 - Agency.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...) 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...

  17. 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...

  18. 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...

  19. 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...

  20. 31 CFR 19.910 - Agency.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... (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...

  1. 31 CFR 19.910 - Agency.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... (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...

  2. 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...

  3. 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...

  4. 21 CFR 1404.910 - Agency.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...) 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...

  5. 31 CFR 19.910 - Agency.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... (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...

  6. 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...

  7. Solar Technologies

    ERIC Educational Resources Information Center

    von Hippel, Frank; Williams, Robert H.

    1975-01-01

    As fossil fuels decrease in availability and environmental concerns increase, soalr energy is becoming a potential major energy source. Already solar energy is used for space heating in homes. Proposals for solar-electric generating systems include land-based or ocean-based collectors and harnessing wind and wave power. Photosynthesis can also…

  8. Solar Sprint

    ERIC Educational Resources Information Center

    Tabor, Richard; Anderson, Stephen

    2007-01-01

    In the "Solar Sprint" activity, students design, test, and race a solar-powered car built with Legos. The use of ratios is incorporated to simulate the actual work of scientists and engineers. This method encourages fourth-grade students to think about multiple variables and stimulates their curiosity when an activity doesn't come out as…

  9. Solar Eclipse

    Atmospheric Science Data Center

    2013-04-19

    ...   View Larger Image On June 10, 2002 the Moon obscured the central portion of the solar disk in a phenomenon known as an annular solar eclipse. Partial phases of the eclipse were visible throughout much of southeast Asia and North ...

  10. Solar retinopathy. A biophysical analysis.

    PubMed

    Sadun, A C; Sadun, A A; Sadun, L A

    1984-10-01

    Funduscopic examination of two young adults complaining of blurred vision revealed small symmetrical macular lesions suggestive of solar retinopathy. Although both patients had recently looked at the sun for less than one minute, it is common to look at the sun for longer periods (ie, sunsets) without incurring visual symptoms of retinal lesions. Our biophysical analysis revealed the important parameters of solar retinopathy and the minimum exposure to the sun that would produce such lesions. Under ideal optical conditions, solar retinopathy can occur following extremely short observations of the sun.

  11. Solar Flare Observations at Submm-waves

    NASA Astrophysics Data System (ADS)

    Kaufmann, P.; Raulin, J.-P.; Correia, E.; Costa, J. E. R.; Guillermo, C.; de Castro, Giménez; Silva, A. V. R.; Levato, H.; Rovira, M.; Mandrini, C.; Fernández-Borda, R.; Bauer, O.

    We report on the recent installation of the new Solar Submillimeter Telescope(SST) at the El Leoncito site, located in the Argentinean Andes, and also show first observational results. The instrument consists of a radome-enclosed 1.5-m cassegrain reflector and a system of two radiometers at 405 GHz and four at 212 GHz. The SST observes the quiet Sun and solar bursts simultaneously at both submillimeter-wave frequencies with a sampling rate of 1 millisecond. Since SST has seen the "first light" in May 1999, nearly 45 hours of continuous tracking of solar active regions were collected during short campaigns which produced first evidence for solar activity. The project has been funded by the Brazilian agency FAPESP, receiving support from the Argentinean agency CONICET through their institutes CASLEO and IAFE and from IAP, University of Bern and the Swiss National Science Foundation.

  12. Solar Feature Catalogues In Egso

    NASA Astrophysics Data System (ADS)

    Zharkova, V. V.; Aboudarham, J.; Zharkov, S.; Ipson, S. S.; Benkhalil, A. K.; Fuller, N.

    2005-05-01

    The Solar Feature Catalogues (SFCs) are created from digitized solar images using automated pattern recognition techniques developed in the European Grid of Solar Observation (EGSO) project. The techniques were applied for detection of sunspots, active regions and filaments in the automatically standardized full-disk solar images in CaSmallCaps">ii K1, CaSmallCaps">ii K3 and Hα taken at the Meudon Observatory and white-light images and magnetograms from SOHO/MDI. The results of automated recognition are verified with the manual synoptic maps and available statistical data from other observatories that revealed high detection accuracy. A structured database of the Solar Feature Catalogues is built on the MySQL server for every feature from their recognized parameters and cross-referenced to the original observations. The SFCs are published on the Bradford University web site http://www.cyber.brad.ac.uk/egso/SFC/ with the pre-designed web pages for a search by time, size and location. The SFCs with 9 year coverage (1996 2004) provide any possible information that can be extracted from full disk digital solar images. Thus information can be used for deeper investigation of the feature origin and association with other features for their automated classification and solar activity forecast.

  13. High open-circuit voltage small-molecule p-DTS(FBTTh 2 )2.ICBA bulk heterojunction solar cells – morphology, excited-state dynamics, and photovoltaic performance

    SciTech Connect

    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 that 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.

  14. A Necessary Course for the 1990s: The Student-Run Advertising Agency.

    ERIC Educational Resources Information Center

    Marra, James L.

    Current advertising courses and educational practices reflect advertising education's allegiance to the real world, particularly the real world as defined by large advertising agencies. A student-run ad agency provides students with a total learning experience on a small advertising agency scale in line with what they are likely to experience in…

  15. Developing Moral Agency through Narrative

    ERIC Educational Resources Information Center

    Pasupathi, Monisha; Wainryb, Cecilia

    2010-01-01

    This paper poses the following question: When, in spite of knowing that it is wrong, people go on to hurt others, what does this mean for the development of moral agency? We begin by defining moral agency and briefly sketching relations between moral agency and other concepts. We then outline what three extant literatures suggest about this…

  16. Multipurpose Communication Satellite solar array

    NASA Astrophysics Data System (ADS)

    Bastard, J. L.; Guyot, Ph.

    Through research and development studies, Aerospatiale has developed with the French National Space Agency (CNES) a new concept of a rigid Solar Array (GSR) which covers a range of power between 1 kW and 10 kW EOL 7 yr. This technology is used by Aerospatiale on the currently running programs:—TELECOM 1, Telecommunication satellite, spinned in transfer; —ARABSAT, Telecommunication satellite, 3-axis stabilized in transfer; —TELE-X and TV-SAT/TDF1, Direct Broadcasting satellites, 3-axis stabilized in transfer. This paper deals with the description and the electrical and mechanical performance of the Multipurpose Communication Satellite Solar Array (M.C.S.). For this satellite, which is expected to be launched in 1984, Aerospatiale has selected the following concept: primary power (1.4 kW EOL 7 yr) will be provided by two separate sun-oriented solar array wings equipped with AEG Telefunken BSR (Back Surface Reflector) solar cells. This solar generator is directly derived from the GSR technology. Owing to the three-axis stabilization of the satellite and the partial deployment of the solar array during the transfer phase it has been necessary to use a primary and a secondary hold-down devices. In the same way the position of the shunt on the solar generator induced an increase of the mass, because of the supplementary hold-down point and of the support structure. Now scribing Laser System leads to the optimization of the solar cells dimensions and allows a better fill factor of the panels and so an increase of the power performance. Beside the M.C.S concept which is fully adapted as regards its mission specifications, it was interesting to present different concepts of solar generators optimized not only as regards mass budget but also power budget. These concepts covering a large range of powers are fully adapted to telecommunication missions.

  17. 78 FR 57877 - Notice of Intent To Prepare an Environmental Impact Statement for the Proposed Maricopa Solar...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-09-20

    ... Maricopa Solar Park Project in Maricopa County, AZ AGENCY: Bureau of Land Management, Interior. ACTION... site at http://www.blm.gov/az/st/en/prog/energy/solar/maricopa-solar.html . In order to be included in... Solar Park Project by any of the following methods: Email: BLM_AZ_Maricopasolar@blm.gov . Fax:...

  18. 77 FR 44267 - Notice of Availability of the Final Programmatic Environmental Impact Statement for Solar Energy...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-27

    ... increase certainty regarding solar energy development on BLM-administered lands. On October 28, 2011 (76 FR... Lake City, Utah 84101. On December 17, 2010 (75 FR 78980), the Agencies published a Draft Programmatic... Environmental Impact Statement for Solar Energy Development in Six Southwestern States AGENCY: Bureau of...

  19. Solar ponds

    SciTech Connect

    Jayadev, T.S.; Edesess, M.

    1980-04-01

    This report first describes the different types of solar ponds including the nonconvecting salt gradient pond and various saltless pond designs. It then discusses the availability and cost of salts for salt gradient ponds, and compares the economics of salty and saltless ponds as a function of salt cost. A simple computational model is developed to approximate solar pond performance. This model is later used to size solar ponds for district heating and industrial process heat applications. For district heating, ponds are sized to provide space conditioning for a group of homes, in different regions of the United States. Size requirements is on the order of one acre for a group of 25 to 50 homes. An economic analysis is performed of solar ponds used in two industrial process heat applications. The analysis finds that solar ponds are competitive when conventional heat sources are priced at $5 per million Btu and expected to rise in price at a rate of 10% per year. The application of solar ponds to the generation of electricity is also discussed. Total solar pond potential for displacing conventional energy sources is estimated in the range of from one to six quadrillion Btu per year in the near and intermediate future.

  20. Solar sail

    SciTech Connect

    Drexler, K.E.

    1986-09-30

    This patent describes a solar sail propulsion system comprising: solar sail means for intercepting light pressure to produce thrust, the solar sail means being a thin metal film; tension truss means having two ends attached at one end to the solar sail means for transferring the thrust from the solar sail and for preventing gross deformation of the solar sail under light pressure, the solar sail means being a plurality of separate generally two-dimensional pieces joined by springs to the tension truss means; a payload attached to the other end of the tension truss means, the tension truss means comprising a plurality of attachment means for attaching shroud lines to the top of the tension truss means and a plurality of the shroud lines attached to the attachment means at one of their ends and the payload at the other; a plurality of reel means attached to the shroud lines for controllably varying the length of the lines; and a plurality of reflective panel means attached to the sail means for controlling the orientation of the system.

  1. Solar ponds

    SciTech Connect

    Jayadev, T.S.; Edesess, M.

    1980-04-01

    The different types of solar ponds are described, including the nonconvecting salt gradient pond and various saltless pond designs. Then the availability and cost of salts for salt gradient ponds are discussed and costs are compared. A simple computational model is developed to approximate solar pond performance. This model is later used to size solar ponds for district heating and industrial process heat applications. For district heating, ponds are sized to provide space conditioning for a group of homes, in different regions of the United States. Size requirement is on the order of one acre for a group of 25 to 50 homes. An economic analysis is performed of solar ponds used in two industrial process heat applications. The analysis finds that solar ponds are competitive when conventional heat sources are priced at $5 per million Btu and expected to rise in price at a rate of 10% per year. The application of solar ponds to the generation of electricity is also discussed. Total solar pond potential for displacing conventional energy sources is estimated in the range of from one to six quadrillion Btu per year in the near and intermediate future.

  2. Solar Spectral Irradiance and Climate

    NASA Technical Reports Server (NTRS)

    Pilewskie, P.; Woods, T.; Cahalan, R.

    2012-01-01

    Spectrally resolved solar irradiance is recognized as being increasingly important to improving our understanding of the manner in which the Sun influences climate. There is strong empirical evidence linking total solar irradiance to surface temperature trends - even though the Sun has likely made only a small contribution to the last half-century's global temperature anomaly - but the amplitudes cannot be explained by direct solar heating alone. The wavelength and height dependence of solar radiation deposition, for example, ozone absorption in the stratosphere, absorption in the ocean mixed layer, and water vapor absorption in the lower troposphere, contribute to the "top-down" and "bottom-up" mechanisms that have been proposed as possible amplifiers of the solar signal. New observations and models of solar spectral irradiance are needed to study these processes and to quantify their impacts on climate. Some of the most recent observations of solar spectral variability from the mid-ultraviolet to the near-infrared have revealed some unexpected behavior that was not anticipated prior to their measurement, based on an understanding from model reconstructions. The atmospheric response to the observed spectral variability, as quantified in climate model simulations, have revealed similarly surprising and in some cases, conflicting results. This talk will provide an overview on the state of our understanding of the spectrally resolved solar irradiance, its variability over many time scales, potential climate impacts, and finally, a discussion on what is required for improving our understanding of Sun-climate connections, including a look forward to future observations.

  3. Solar Two

    SciTech Connect

    Not Available

    1998-04-01

    Solar Two is a concentrating solar power plant that can supply electric power on demand to the local utility, Southern California Edison Company. It can do so because it operates not only during sunny parts of the day, but it can store enough thermal energy from the sun to operate during cloudy periods and after dark, for up to three hours, at its rated output of 10 megawatts (MW). For the first time ever, a utility scale solar power plant can supply electricity when the utility needs it most, to satisfy the energy requirements of its customers.

  4. Helioseismology with Solar Orbiter

    NASA Astrophysics Data System (ADS)

    Löptien, Björn; Birch, Aaron C.; Gizon, Laurent; Schou, Jesper; Appourchaux, Thierry; Blanco Rodríguez, Julián; Cally, Paul S.; Dominguez-Tagle, Carlos; Gandorfer, Achim; Hill, Frank; Hirzberger, Johann; Scherrer, Philip H.; Solanki, Sami K.

    2015-12-01

    The Solar Orbiter mission, to be launched in July 2017, will carry a suite of remote sensing and in-situ instruments, including the Polarimetric and Helioseismic Imager (PHI). PHI will deliver high-cadence images of the Sun in intensity and Doppler velocity suitable for carrying out novel helioseismic studies. The orbit of the Solar Orbiter spacecraft will reach a solar latitude of up to 21∘ (up to 34∘ by the end of the extended mission) and thus will enable the first local helioseismology studies of the polar regions. Here we consider an array of science objectives to be addressed by helioseismology within the baseline telemetry allocation (51 Gbit per orbit, current baseline) and within the science observing windows (baseline 3×10 days per orbit). A particularly important objective is the measurement of large-scale flows at high latitudes (rotation and meridional flow), which are largely unknown but play an important role in flux transport dynamos. For both helioseismology and feature tracking methods convection is a source of noise in the measurement of longitudinally averaged large-scale flows, which decreases as T -1/2 where T is the total duration of the observations. Therefore, the detection of small amplitude signals (e.g., meridional circulation, flows in the deep solar interior) requires long observation times. As an example, one hundred days of observations at lower spatial resolution would provide a noise level of about three m/s on the meridional flow at 80∘ latitude. Longer time-series are also needed to study temporal variations with the solar cycle. The full range of Earth-Sun-spacecraft angles provided by the orbit will enable helioseismology from two vantage points by combining PHI with another instrument: stereoscopic helioseismology will allow the study of the deep solar interior and a better understanding of the physics of solar oscillations in both quiet Sun and sunspots. We have used a model of the PHI instrument to study its

  5. Solar chulha

    NASA Astrophysics Data System (ADS)

    Jadhao, P. H.; Patrikar, S. R.

    2016-05-01

    The main goal of the proposed system is to transfer energy from sun to the cooking load that is located in the kitchen. The energy is first collected by the solar collector lens system and two curve bars of same radius of curvature are mounted parallel and adjacent to each other at different height the solar collector is clamed on this two bars such that solar collector is exactly perpendicular to sunlight. The topology includes an additional feature which is window in the wall through which the beam is collimated is directed in the of kitchen. The solar energy that is collected is directed by the mirror system into the kitchen, where it is redirected to cooking platform located in the kitchen. The special feature in this system full Indian meal can be made since cooking platform is indoors.

  6. Solar dryer

    SciTech Connect

    Dodelin, R.W.; Hurst, D.W.; Osos, G.R.

    1984-02-07

    Fabrics are dried by tumbling the fabrics in a drying chamber into which hot air is introduced. The hot air is formed by passing ambient air through a solar heater to heat the air to a first temperature, and then further heating the air with a second heater such as a burner. The burner can be one which burns a fuel in the presence of combustion air. The combustion air can be a portion of the air that is passed through the solar heater. After drying the fabrics by this method, the drying zone can be cooled and the fabrics can be further dried by passing air through the solar heater, and then without further heating the air that has passed through the solar heater, introducing the air to the drying chamber.

  7. Solar cell

    SciTech Connect

    Frank, R.I.; Kaplow, R.

    1980-08-26

    An improved solar cell designed for optimum efficiency is comprised of a plurality of series connected unit solar cells formed from a common substrate of semiconductor material. Each unit solar cell has spaced elongate sidewalls, and a ''dead space'' area between adjoining sidewalls of adjacent units is made substantially smaller than an active, light receiving area, extending between the opposite sidewalls of each individual unit. In addition, the width of the active area is concisely limited to ensure that radiation incident on the active area is incident at a point which is spaced from the p-n junction of each unit by no more than a predetermined optimum distance. Reducing the ''dead space'' area while concisely limiting the width of the active area provides improved solar cell performance without requiring focusing lenses.

  8. Solar Energy

    ERIC Educational Resources Information Center

    Building Design and Construction, 1977

    1977-01-01

    Describes 21 completed projects now using solar energy for heating, cooling, or electricity. Included are elementary schools in Atlanta and San Diego, a technical school in Detroit, and Trinity University in San Antonio, Texas. (MLF)

  9. Solar Nexus.

    ERIC Educational Resources Information Center

    Murphy, Jim

    1980-01-01

    The design team for the Solar Energy Research Institute (SERI) has pushed the state of the energy art to its current limits for the initial phase, with provisions for foreseeable and even speculative future applications. (Author/MLF)

  10. Neuromodulation, agency and autonomy.

    PubMed

    Glannon, Walter

    2014-01-01

    Neuromodulation consists in altering brain activity to restore mental and physical functions in individuals with neuropsychiatric disorders and brain and spinal cord injuries. This can be achieved by delivering electrical stimulation that excites or inhibits neural tissue, by using electrical signals in the brain to move computer cursors or robotic arms, or by displaying brain activity to subjects who regulate that activity by their own responses to it. As enabling prostheses, deep-brain stimulation and brain-computer interfaces (BCIs) are forms of extended embodiment that become integrated into the individual's conception of himself as an autonomous agent. In BCIs and neurofeedback, the success or failure of the techniques depends on the interaction between the learner and the trainer. The restoration of agency and autonomy through neuromodulation thus involves neurophysiological, psychological and social factors.

  11. Solar Cells

    NASA Technical Reports Server (NTRS)

    1983-01-01

    The Heat Exchanger Method (HEM) produces high efficiency crystal ingots in an automated well-insulated furnace offering low equipment, labor and energy costs. The "grown" silicon crystals are used to make solar cells, or photovoltaic cells which convert sunlight directly into electricity. The HEM method is used by Crystal Systems, Inc. and was developed under a NASA/Jet Propulsion Laboratory contract. The square wafers which are the result of the process are sold to companies manufacturing solar panels.

  12. Solar terrestrial radiation data from the Sleepers River Research Watershed

    NASA Astrophysics Data System (ADS)

    Hardy, Janet P.

    1994-08-01

    A long-term (24-year) database of solar and terrestrial radiation, as monitored in northern Vermont, has been compiled. This extensive database is a result of cooperative efforts among many different government agencies. This report summarizes the present status of the solar and terrestrial radiation database, the instrumentation and calibration, and methods of data measurement, acquisition and analysis.

  13. Manned Mars mission solar physics: Solar energetic particle prediction and warning

    NASA Technical Reports Server (NTRS)

    Suess, S. T.

    1986-01-01

    There are specific risks to the crew of the manned Mars mission from energetic particles generated by solar activity. Therefore, mission planning must provide for solar monitoring and solar activity forecasts. The main need is to be able to anticipate the energetic particle events associated with some solar flares and, occasionally, with erupting filaments. A second need may be for forecasts of solar interference with radio communication between the manned Mars mission (during any of its three phases) and Earth. These two tasks are compatible with a small solar observatory that would be used during the transit and orbital phases of the mission. Images of the Sun would be made several times per hour and, together with a solar X-ray detector, used to monitor for the occurrence of solar activity. The data would also provide a basis for research studies of the interplanetary medium utilizing observations covering more of the surface of the Sun than just the portion facing Earth.

  14. Solar Schematic

    NASA Technical Reports Server (NTRS)

    1979-01-01

    The home shown at right is specially designed to accommodate solar heating units; it has roof planes in four directions, allowing placement of solar collectors for best exposure to the sun. Plans (bottom) and complete working blueprints for the solar-heated house are being marketed by Home Building Plan Service, Portland, Oregon. The company also offers an inexpensive schematic (center) showing how a homeowner only moderately skilled in the use of tools can build his own solar energy system, applicable to new or existing structures. The schematic is based upon the design of a low-cost solar home heating system built and tested by NASA's Langley Research Center; used to supplement a warm-air heating system, it can save the homeowner about 40 percent of his annual heating bill for a modest investment in materials and components. Home Building Plan Service saved considerable research time by obtaining a NASA technical report which details the Langley work. The resulting schematic includes construction plans and simplified explanations of solar heat collection, collectors and other components, passive heat factors, domestic hot water supply and how to work with local heating engineers.

  15. The Gaia Investigation of the Solar System

    NASA Astrophysics Data System (ADS)

    Delbo, Marco; Tanga, Paolo; Mignard, Francois; Cellino, Alberto; Hestroffer, Daniel

    2015-08-01

    The space mission Gaia of the European Space Agency (ESA) has begun its scientific whole-sky survey of all astrophysical sources with V<=20 in July 2014. The high precision astrometry is the main science driver for the mission, but Gaia will also obtain visible photometry and low-resolution spectroscopy of the observed sources, including solar system small bodies. Preliminary results show a good quality of the data, in general, in line with the expected pre-flight specifications. These data will consist a mine of information for a remote-sensing exploration of the small worlds of our Solar System. Indeed, ~250,000 asteroids will be observed by Gaia throughout its 5-years-long mission. After an update about the status of the mission and the on-going data analysis, including some preliminary results, we are going to present the plans for the data releases, the first foreseen at the end of 2016, and the general data treatment.We will show how Gaia spectroscopy will allow up to map the composition of about 100,000 asteroids throughout the Main Belt, with high signal to noise ratio. Given its advantage position outside the Earth's atmosphere, the blue part of the spectrum (roughly below 0.5 micron) will be observed for an unprecedented number of asteroids.Additionally, precise photometry and astrometry will also be important to reveal the physical nature of these small bodies. In particular, it is estimated that three-dimensional shapes, rotation, period and pole orientation will be derived for 10,000 asteroids. The masses of about 150 of the largest asteroids, will be determined from measurements of the orbital gravitational perturbations that these bodies will exert on small asteroids during mutual close approaches.Moreover, the combination of Gaia data (delivering masses and shapes) with infrared radiometric observations, e.g. from the NASA WISE mission (informing us about the size of the bodies), will allow precise asteroid bulk densities to be determined. The bulk

  16. Small Bodies, Big Discoveries: NASA's Small Bodies Education Program

    NASA Astrophysics Data System (ADS)

    Mayo, L.; Erickson, K. J.

    2014-12-01

    2014 is turning out to be a watershed year for celestial events involving the solar system's unsung heroes, small bodies. This includes the close flyby of comet C/2013 A1 / Siding Spring with Mars in October and the historic Rosetta mission with its Philae lander to comet 67P/Churyumov-Gerasimenko. Beyond 2014, the much anticipated 2015 Pluto flyby by New Horizons and the February Dawn Mission arrival at Ceres will take center stage. To deliver the excitement and wonder of our solar system's small bodies to worldwide audiences, NASA's JPL and GSFC education teams in partnership with NASA EDGE will reach out to the public through multiple venues including broadcast media, social media, science and math focused educational activities, observing challenges, interactive visualization tools like "Eyes on the Solar System" and more. This talk will highlight NASA's focused education effort to engage the public in small bodies mission science and the role these objects play in our understanding of the formation and evolution of the solar system.

  17. Variation of solar cell sensitivity and solar radiation on tilted surfaces

    NASA Technical Reports Server (NTRS)

    Klucher, T. M.

    1978-01-01

    The validity is studied that one of various insolation models used to compute solar radiation incident on tilted surfaces from global data measured on horizontal surfaces. The variation of solar cell sensitivity to solar radiation is determined over a wide range of atmospheric condition. A new model was formulated that reduced the deviations between measured and predicted insolation to less than 3 percent. Evaluation of solar cell sensitivity data indicates small change (2-3 percent) in sensitivity from winter to summer for tilted cells. The feasibility of using such global data as a means for calibrating terrestrial solar cells is discussed.

  18. Microgrid-Ready Solar PV; NREL (National Renewable Energy Laboratory)

    SciTech Connect

    2015-07-01

    Designing new solar projects to be 'microgrid-ready' enables the U.S. DoD, other federal agencies, and the private sector to plan future microgrid initiatives to utilize solar PV as a generating resource. This fact sheet provides background information with suggested language for several up-front considerations that can be added to a solar project procurement or request for proposal (RFP) that will help ensure that PV systems are built for future microgrid connection.

  19. Small Wins.

    ERIC Educational Resources Information Center

    Rhatigan, James J.; Schuh, John H.

    2003-01-01

    Examines how it easy for people to overlook small successes when they are overwhelmed by and preoccupied with large projects and goals. Explores the concept of "small wins" in organizational theory, which have the potential to become a prominent part of institutional culture and impact organizational behavior and change. (GCP)

  20. Small Cultures.

    ERIC Educational Resources Information Center

    Holliday, Adrian

    1999-01-01

    Presents a notion of small culture as an alternative to what has become the default notion of large culture in applied linguistics, social science, and popular usage. A small-culture view of English-language curriculum settings reveals mismatches between professional-academic and organizational cultures at the mezzo level of the institution. (VWL)