Science.gov

Sample records for largest electricity source

  1. Source of electricity

    SciTech Connect

    Marhanka, F.D.

    1983-06-28

    A source of electricity has a first electrode, a second electrode which is spaced from the first electrode and which is made from a metal that is displaced in the electromotive series from the metal of the first electrode, a first mass which is electrically conductive and which contains particulates and liquid and which is in electrically-conducting engagement with the inner surface of the first electrode, a second mass which is electrically conductive and which contains particulates and liquid and which is in electrically-conducting engagement with the inner surface of the second electrode and which has at least one particulate that is different from all of the particulates in the first mass, an interface between the confronting surfaces of the first and second masses, a polarity-imparting material in one of the masses, and that polarity-imparting material and the liquids enabling the masses to cause the electrodes to supply a unidirectional flow of current to any load which is connected across them.

  2. A method for reducing the largest relative errors in Monte Carlo iterated-fission-source calculations

    SciTech Connect

    Hunter, J. L.; Sutton, T. M.

    2013-07-01

    In Monte Carlo iterated-fission-source calculations relative uncertainties on local tallies tend to be larger in lower-power regions and smaller in higher-power regions. Reducing the largest uncertainties to an acceptable level simply by running a larger number of neutron histories is often prohibitively expensive. The uniform fission site method has been developed to yield a more spatially-uniform distribution of relative uncertainties. This is accomplished by biasing the density of fission neutron source sites while not biasing the solution. The method is integrated into the source iteration process, and does not require any auxiliary forward or adjoint calculations. For a given amount of computational effort, the use of the method results in a reduction of the largest uncertainties relative to the standard algorithm. Two variants of the method have been implemented and tested. Both have been shown to be effective. (authors)

  3. Active sand dunes are largest dust source in the Sahara Desert

    NASA Astrophysics Data System (ADS)

    Bhattacharya, Atreyee

    2012-09-01

    Dried up lakebeds and playas in the Sahara Desert of North Africa are large sources of dust in the atmosphere. The Bodélé Depression at the southern edge of the Sahara Desert, for example, is the single largest source of dust in the world; on average, 100 dust storms a year originate from the Bodélé Depression. A new study by Crouvi et al., however, finds that active sand dunes could be even bigger sources of desert dust in the atmosphere. Atmospheric dust plays active roles in climate and biological processes in the ocean: It regulates heating at the surface of the Earth; modifies cloud properties that affect rainfall; and acts as the only source of iron, a critical nutrient for microorganisms in the ocean. Little is known about types of dust sources in the Sahara Desert, which alone accounts for more than 50% of the dust in the atmosphere.

  4. Current Hybrid Electric Vehicle performance based on temporal data from the world's largest HEV fleet

    NASA Astrophysics Data System (ADS)

    Wipke, K.

    1994-09-01

    The United States Department of Energy (DOE) procured new data collection equipment for the 42 vehicles registered to compete in the 1994 Hybrid Electric Vehicle (HEV) Challenge, increasing the amount of information gathered from the worlds largest fleet of HEVs. Data were collected through an on-board data storage device and then analyzed to determine effects of different hybrid control strategies on energy efficiency and driving performance. In this paper, the results of parallel hybrids versus series hybrids with respect to energy usage and acceleration performance are examined, and the efficiency and performance of the power-assist types are compared to that of the range-extender types. Because on-board and off-board electrical charging performance is critical to an efficient vehicle energy usage cycle, charging performance is presented and changes and improvements from the 1993 HEV Challenge are discussed. Peak power used during acceleration is presented and then compared to the electric motor manufacturer ratings. Improvements in data acquisition methods for the 1995 HEV Challenge are recommended.

  5. Nuclear electric power sources

    NASA Technical Reports Server (NTRS)

    Singh, J. J.

    1978-01-01

    Measurements on radioactive commercial p-n junction silicon cells show that these units are capable of delivering several hundred microwatts per curie of Am-241 alpha source, indicating their usefulness in such electronic devices as hearing aids, heart pacemakers, electronic watches, delay timers and nuclear dosimeter chargers. It is concluded that the Am-241 sources are superior to the beta sources used previously, because of higher alpha specific ionization and simultaneous production of low energy photons which are easily converted into photoelectrons for additional power.

  6. Compact portable electric power sources

    SciTech Connect

    Fry, D.N.; Holcomb, D.E.; Munro, J.K.; Oakes, L.C.; Matson, M.J.

    1997-02-01

    This report provides an overview of recent advances in portable electric power source (PEPS) technology and an assessment of emerging PEPS technologies that may meet US Special Operations Command`s (SOCOM) needs in the next 1--2- and 3--5-year time frames. The assessment was performed through a literature search and interviews with experts in various laboratories and companies. Nineteen PEPS technologies were reviewed and characterized as (1) PEPSs that meet SOCOM requirements; (2) PEPSs that could fulfill requirements for special field conditions and locations; (3) potentially high-payoff sources that require additional R and D; and (4) sources unlikely to meet present SOCOM requirements. 6 figs., 10 tabs.

  7. BLACK Carbon Emissions from Diesel Sources in the Largest Arctic City: Case Study of Murmansk

    NASA Astrophysics Data System (ADS)

    Evans, M.; Kholod, N.; Malyshev, V.; Tretyakova, S.; Gusev, E.; Yu, S.; Barinov, A.

    2014-12-01

    Russia has very little data on its black carbon (BC) emissions. Because Russia makes up such a large share of the Arctic, understanding Russian emissions will improve our understanding of overall BC levels, BC in the Arctic and the link between BC and climate change. This paper provides a detailed, bottom-up inventory of BC emissions from diesel sources in Murmansk, Russia, along with uncertainty estimates associated with these emissions. The research team developed a detailed data collection methodology. The methodology involves assessing the vehicle fleet and activity in Murmansk using traffic, parking lot and driver surveys combined with an existing database from a vehicle inspection station and statistical data. The team also assessed the most appropriate emission factors, drawing from both Russian and international inventory methodologies. The researchers also compared fuel consumption using statistical data and bottom-up fuel calculations. They then calculated emissions for on-road transportation, off-road transportation (including mines), diesel generators, fishing and other sources. The article also provides a preliminary assessment of Russia-wide emissions of black carbon from diesel sources.

  8. Electricity generation by intermittent sources

    NASA Astrophysics Data System (ADS)

    Wagner, F.

    2015-08-01

    This paper deals with the production of electricity by wind and photovoltaic (PV) power mostly in Germany. The German data of 2012 are scaled to a 100% supply of the electricity consumption by renewable sources. Wind and PV power are mixed in a ratio which minimises back-up energy. The 100%, optimal mix data are used to identify the powers to be installed, the accumulating backup and surplus energies, the size of storage to replace thermal back-up power, the possibilities of demand-side-management, and the specific CO2 production. The benefits of using an EU-wide field of renewable energies (RES) instead of the national one are quantified and the interconnection capacities specified. Finally, the costs of installing RES are discussed. The conclusion is that a 100% supply by RES may not be meaningful. Large-scale supply by RES alone has deficiencies and it will remain a major task for science and technology to either improve such a system or find a suitable replacement.

  9. Fluid jet electric discharge source

    DOEpatents

    Bender, Howard A.

    2006-04-25

    A fluid jet or filament source and a pair of coaxial high voltage electrodes, in combination, comprise an electrical discharge system to produce radiation and, in particular, EUV radiation. The fluid jet source is composed of at least two serially connected reservoirs, a first reservoir into which a fluid, that can be either a liquid or a gas, can be fed at some pressure higher than atmospheric and a second reservoir maintained at a lower pressure than the first. The fluid is allowed to expand through an aperture into a high vacuum region between a pair of coaxial electrodes. This second expansion produces a narrow well-directed fluid jet whose size is dependent on the size and configuration of the apertures and the pressure used in the reservoir. At some time during the flow of the fluid filament, a high voltage pulse is applied to the electrodes to excite the fluid to form a plasma which provides the desired radiation; the wavelength of the radiation being determined by the composition of the fluid.

  10. Ragweed pollen source inventory for France - The second largest centre of Ambrosia in Europe

    NASA Astrophysics Data System (ADS)

    Thibaudon, Michel; Šikoparija, Branko; Oliver, Gilles; Smith, Matt; Skjøth, Carsten A.

    2014-02-01

    France, in particular the Rhône-Alpes region, is one of the three main centres of ragweed (Ambrosia) in Europe. The aim of this study is to develop a gridded ragweed pollen source inventory for all of France that can be used in assessments, eradication plans and by atmospheric models for describing concentrations of airborne ragweed pollen. The inventory combines information about spatial variations in annual Ambrosia pollen counts, knowledge of ragweed ecology, detailed land cover information and a Digital Elevation Model. The ragweed inventory consists of a local infection level on a scale of 0-100% (where 100% is the highest plant abundance per area in the studied region) and a European infection level between 0% and 100% (where 100% relates to the highest identified plant abundance in Europe using the same methodology) that has been distributed onto the EMEP grid with 5 km × 5 km resolution. The results of this analysis showed that some of the highest mean annual ragweed pollen concentrations were recorded at Roussillon in the Rhône-Valley. This is reflected by the inventory, where the European infection level has been estimated to reach 67.70% of the most infected areas in Europe i.e. Kecskemét in central Hungary. The inventory shows that the Rhône Valley is the most heavily infected part of France. Central France is also infected, but northern and western parts of France are much less infected. The inventory can be entered into atmospheric transport models, in combination with other components such as a phenological model and a model for daily pollen release, in order to simulate the dispersion of ragweed pollen within France as well as potential long-distance transport from France to other European countries.

  11. Electrical Neuroimaging with Irrotational Sources

    PubMed Central

    Grave de Peralta Menendez, Rolando; Gonzalez Andino, Sara

    2015-01-01

    This paper discusses theoretical aspects of the modeling of the sources of the EEG (i.e., the bioelectromagnetic inverse problem or source localization problem). Using the Helmholtz decomposition (HD) of the current density vector (CDV) of the primary current into an irrotational (I) and a solenoidal (S) part we show that only the irrotational part can contribute to the EEG measurements. In particular we present for the first time the HD of a dipole and of a pure irrotational source. We show that, for both kinds of sources, I extends all over the space independently of whether the source is spatially concentrated (as the dipole) or not. However, the divergence remains confined to a region coinciding with the expected location of the sources, confirming that it is the divergence rather than the CDV that really defines the spatial extension of the generators, from where it follows that an irrotational source model (ELECTRA) is always physiologically meaningful as long as the divergence remains confined to the brain. Finally we show that the irrotational source model remains valid for the most general electrodynamics model of the EEG in inhomogeneous anisotropic dispersive media and thus far beyond the (quasi) static approximation. PMID:26113873

  12. A multipurpose secondary source of electric power

    NASA Astrophysics Data System (ADS)

    Duplin, N. I.; Ivanov, S. R.

    The source can be used as a constant-voltage regulator, a constant-current regulator, a simulator of solar cells and thermoemission oscillators, and a generator of voltage and current pulses of high power. It can also be used in electric welding. The source consists of a series of transforming cells/current regulators in a linear control. The design provides for the automatic connection and disconnection of the required number of cells. The mode of operation is controlled by a switch.

  13. Optically-electrically pumped THz source

    NASA Astrophysics Data System (ADS)

    Haji-Saeed, Bahareh; Khoury, Jed; Buchwald, Walter; Woods, Charles; Wentzell, Sandra; Krejca, Brian; Kierstead, John

    2010-08-01

    In this paper, we propose a design for a widely tunable solid-state optically and electrically pumped THz source based on the Smith-Purcell free-electron laser. Our design consists of a thin dielectric layer sandwiched between an upper corrugated structure and a lower layer of thin metal, semiconductor, or high electron mobility material. The lower layer is for current streaming, which replaces the electron beam in the Smith-Purcell free-electron laser design. The upper layer consists of two micro-gratings for optical pumping, and a nano-grating to couple with electrical pumping in the lower layer. The optically generated surface plasmon waves from the upper layer and the electrically induced surface plasmon waves from the lower layer are then coupled. Emission enhancement occurs when the plasmonic waves in both layers are resonantly coupled.

  14. Extreme-UV electrical discharge source

    DOEpatents

    Fornaciari, Neal R.; Nygren, Richard E.; Ulrickson, Michael A.

    2002-01-01

    An extreme ultraviolet and soft x-ray radiation electric capillary discharge source that includes a boron nitride housing defining a capillary bore that is positioned between two electrodes one of which is connected to a source of electric potential can generate a high EUV and soft x-ray radiation flux from the capillary bore outlet with minimal debris. The electrode that is positioned adjacent the capillary bore outlet is typically grounded. Pyrolytic boron nitride, highly oriented pyrolytic boron nitride, and cubic boron nitride are particularly suited. The boron nitride capillary bore can be configured as an insert that is encased in an exterior housing that is constructed of a thermally conductive material. Positioning the ground electrode sufficiently close to the capillary bore outlet also reduces bore erosion.

  15. Electric Power From Ambient Energy Sources

    SciTech Connect

    DeSteese, John G.; Hammerstrom, Donald J.; Schienbein, Lawrence A.

    2000-10-03

    This report summarizes research on opportunities to produce electric power from ambient sources as an alternative to using portable battery packs or hydrocarbon-fueled systems in remote areas. The work was an activity in the Advanced Concepts Project conducted by Pacific Northwest National Laboratory (PNNL) for the Office of Research and Development in the U.S. Department of Energy Office of Nonproliferation and National Security.

  16. 46 CFR 28.375 - Emergency source of electrical power.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 1 2011-10-01 2011-10-01 false Emergency source of electrical power. 28.375 Section 28... power. (a) Each vessel must have an emergency source of electrical power which is independent of the main sources of electrical power and which is located outside the main machinery space. (b)...

  17. 46 CFR 28.870 - Emergency source of electrical power.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 1 2012-10-01 2012-10-01 false Emergency source of electrical power. 28.870 Section 28... COMMERCIAL FISHING INDUSTRY VESSELS Aleutian Trade Act Vessels § 28.870 Emergency source of electrical power. (a) The following electrical loads must be connected to an independent emergency source of...

  18. 46 CFR 28.870 - Emergency source of electrical power.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 1 2011-10-01 2011-10-01 false Emergency source of electrical power. 28.870 Section 28... COMMERCIAL FISHING INDUSTRY VESSELS Aleutian Trade Act Vessels § 28.870 Emergency source of electrical power. (a) The following electrical loads must be connected to an independent emergency source of...

  19. 46 CFR 28.870 - Emergency source of electrical power.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 1 2013-10-01 2013-10-01 false Emergency source of electrical power. 28.870 Section 28... COMMERCIAL FISHING INDUSTRY VESSELS Aleutian Trade Act Vessels § 28.870 Emergency source of electrical power. (a) The following electrical loads must be connected to an independent emergency source of...

  20. 46 CFR 28.375 - Emergency source of electrical power.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 1 2012-10-01 2012-10-01 false Emergency source of electrical power. 28.375 Section 28... power. (a) Each vessel must have an emergency source of electrical power which is independent of the main sources of electrical power and which is located outside the main machinery space. (b)...

  1. 46 CFR 28.870 - Emergency source of electrical power.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 1 2010-10-01 2010-10-01 false Emergency source of electrical power. 28.870 Section 28... COMMERCIAL FISHING INDUSTRY VESSELS Aleutian Trade Act Vessels § 28.870 Emergency source of electrical power. (a) The following electrical loads must be connected to an independent emergency source of...

  2. 46 CFR 28.375 - Emergency source of electrical power.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 1 2013-10-01 2013-10-01 false Emergency source of electrical power. 28.375 Section 28... power. (a) Each vessel must have an emergency source of electrical power which is independent of the main sources of electrical power and which is located outside the main machinery space. (b)...

  3. 46 CFR 28.375 - Emergency source of electrical power.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 1 2010-10-01 2010-10-01 false Emergency source of electrical power. 28.375 Section 28... power. (a) Each vessel must have an emergency source of electrical power which is independent of the main sources of electrical power and which is located outside the main machinery space. (b)...

  4. Restrictive loads powered by separate or by common electrical sources

    NASA Technical Reports Server (NTRS)

    Appelbaum, J.

    1989-01-01

    In designing a multiple load electrical system, the designer may wish to compare the performance of two setups: a common electrical source powering all loads, or separate electrical sources powering individual loads. Three types of electrical sources: an ideal voltage source, an ideal current source, and solar cell source powering resistive loads were analyzed for their performances in separate and common source systems. A mathematical proof is given, for each case, indicating the merit of the separate or common source system. The main conclusions are: (1) identical resistive loads powered by ideal voltage sources perform the same in both system setups, (2) nonidentical resistive loads powered by ideal voltage sources perform the same in both system setups, (3) nonidentical resistive loads powered by ideal current sources have higher performance in separate source systems, and (4) nonidentical resistive loads powered by solar cells have higher performance in a common source system for a wide range of load resistances.

  5. 46 CFR 28.850 - Main source of electrical power.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 1 2011-10-01 2011-10-01 false Main source of electrical power. 28.850 Section 28.850... FISHING INDUSTRY VESSELS Aleutian Trade Act Vessels § 28.850 Main source of electrical power. (a) Applicability: Each vessel that relies on electricity to power any of the following essential loads must have...

  6. 46 CFR 28.870 - Emergency source of electrical power.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 1 2014-10-01 2014-10-01 false Emergency source of electrical power. 28.870 Section 28.870 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY UNINSPECTED VESSELS REQUIREMENTS FOR COMMERCIAL FISHING INDUSTRY VESSELS Aleutian Trade Act Vessels § 28.870 Emergency source of electrical power. (a) The following electrical loads must...

  7. 46 CFR 28.850 - Main source of electrical power.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 1 2010-10-01 2010-10-01 false Main source of electrical power. 28.850 Section 28.850... FISHING INDUSTRY VESSELS Aleutian Trade Act Vessels § 28.850 Main source of electrical power. (a) Applicability: Each vessel that relies on electricity to power any of the following essential loads must have...

  8. 46 CFR 28.850 - Main source of electrical power.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 1 2012-10-01 2012-10-01 false Main source of electrical power. 28.850 Section 28.850... FISHING INDUSTRY VESSELS Aleutian Trade Act Vessels § 28.850 Main source of electrical power. (a) Applicability: Each vessel that relies on electricity to power any of the following essential loads must have...

  9. 46 CFR 28.355 - Main source of electrical power.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 1 2010-10-01 2010-10-01 false Main source of electrical power. 28.355 Section 28.355... Operate With More Than 16 Individuals on Board § 28.355 Main source of electrical power. (a) Applicability. Each vessel that relies on electricity to power any of the following essential loads must have at...

  10. 46 CFR 28.355 - Main source of electrical power.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 1 2012-10-01 2012-10-01 false Main source of electrical power. 28.355 Section 28.355... Operate With More Than 16 Individuals on Board § 28.355 Main source of electrical power. (a) Applicability. Each vessel that relies on electricity to power any of the following essential loads must have at...

  11. 46 CFR 28.355 - Main source of electrical power.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 1 2011-10-01 2011-10-01 false Main source of electrical power. 28.355 Section 28.355... Operate With More Than 16 Individuals on Board § 28.355 Main source of electrical power. (a) Applicability. Each vessel that relies on electricity to power any of the following essential loads must have at...

  12. 46 CFR 28.850 - Main source of electrical power.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 1 2013-10-01 2013-10-01 false Main source of electrical power. 28.850 Section 28.850... FISHING INDUSTRY VESSELS Aleutian Trade Act Vessels § 28.850 Main source of electrical power. (a) Applicability: Each vessel that relies on electricity to power any of the following essential loads must have...

  13. 46 CFR 28.355 - Main source of electrical power.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 1 2013-10-01 2013-10-01 false Main source of electrical power. 28.355 Section 28.355... Operate With More Than 16 Individuals on Board § 28.355 Main source of electrical power. (a) Applicability. Each vessel that relies on electricity to power any of the following essential loads must have at...

  14. 46 CFR 28.850 - Main source of electrical power.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 1 2014-10-01 2014-10-01 false Main source of electrical power. 28.850 Section 28.850 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY UNINSPECTED VESSELS REQUIREMENTS FOR COMMERCIAL FISHING INDUSTRY VESSELS Aleutian Trade Act Vessels § 28.850 Main source of electrical power. (a) Applicability: Each vessel that relies...

  15. 77 FR 18872 - Availability of Electric Power Sources

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-28

    ... on September 24, 2010 (75 FR 5844) for a 60 day public comment period. The public comment period... COMMISSION Availability of Electric Power Sources AGENCY: Nuclear Regulatory Commission. ACTION: Regulatory... 1 of Regulatory Guide (RG) 1.93, ``Availability of Electric Power Sources.'' This guide...

  16. Wind energy as a significant source of electricity

    SciTech Connect

    Nix, R G

    1995-01-01

    Wind energy is a commercially available renewable energy source, with state-of-the-art wind plants producing electricity at about $0.05 per kWh. However, even at that production cost, wind-generated electricity is not yet fully cost-competitive with coal- or natural-gas-produced electricity for the bulk electricity market. The wind is a proven energy source; it is not resource-limited in the US, and there are no insolvable technical constraints. This paper describes current and historical technology, characterizes existing trends, and describes the research and development required to reduce the cost of wind-generated electricity to full competitiveness with fossil-fuel-generated electricity for the bulk electricity market. Potential markets are described.

  17. The sources of electrically evoked otoacoustic emissions.

    PubMed

    Zou, Yuan; Zheng, Jiefu; Nuttall, Alfred L; Ren, Tianying

    2003-06-01

    It has been hypothesized that electrically evoked otoacoustic emissions (EEOAEs) are generated at a site on the basilar membrane near the stimulating electrode. From this original site, the energy propagates towards the oval window, giving rise to the short time delay component (SDC) of EEOAEs. The energy also propagates towards its characteristic frequency (CF) location, and the emission reflected from the CF location forms a long time delay component (LDC). This hypothesis is directly tested in this study by using an acoustical swept tone to modulate the EEOAEs generated by alternating electric current delivered to the round window niche in gerbils. An acoustical tone with a high sound pressure level or a small frequency separation from the EEOAE frequency induced a strong suppression of the EEOAE LDC, but no obvious suppression of the SDC. When the electrical current frequency was fixed, the swept acoustic tone induced a slight suppression, an enhanced peak, and a strong suppression of EEOAEs as the acoustic frequency was swept from the low to high frequency. These data indicate that the electrical current induced cochlear partition vibration near the stimulating electrode. One part of this energy propagates directly to the ear canal, forming the SDC, and the other part propagates to its CF place and is reflected from there to the ear canal, forming the LDC. PMID:12782357

  18. Ohm's Law and Electrical Sources, a Programmed Text.

    ERIC Educational Resources Information Center

    Balabanian, Norman

    This programed textbook was developed under contract with the United States Office of Education as Number 2 of a series of materials for use in an electrical engineering sequence. It is divided into five parts--(1) Ohm's Law, (2) resistance, (3) conductance, (4) voltage sources, and (5) current sources. (DH)

  19. Electrically driven single photon source at high temperature

    NASA Astrophysics Data System (ADS)

    El Halawany, Ahmed; Leuenberger, Michael N.

    2016-03-01

    We present a theoretical model for an electrically driven single photon source operating at high temperatures. We show that decoherence, which is usually the main obstacle for operating single photon sources at high temperatures, ensures an efficient operation of the presented electrically driven single photon source at high temperatures. The single-photon source is driven by a single electron source attached to a heterostructure semiconductor nanoring. The electron’s dynamics in the nanoring and the subsequent recombination with the hole is described by the generalized master equation with a Hamiltonian based on tight-binding model, taking into account the electron-LO phonon interaction. As a result of decoherence, an almost 100% single photon emission with a strong antibunching behavior i.e. {{g}(2)}(0)\\ll 1 at high temperature up to 300 K is achieved.

  20. Electrically driven single photon source at high temperature.

    PubMed

    El Halawany, Ahmed; Leuenberger, Michael N

    2016-03-01

    We present a theoretical model for an electrically driven single photon source operating at high temperatures. We show that decoherence, which is usually the main obstacle for operating single photon sources at high temperatures, ensures an efficient operation of the presented electrically driven single photon source at high temperatures. The single-photon source is driven by a single electron source attached to a heterostructure semiconductor nanoring. The electron's dynamics in the nanoring and the subsequent recombination with the hole is described by the generalized master equation with a Hamiltonian based on tight-binding model, taking into account the electron-LO phonon interaction. As a result of decoherence, an almost 100% single photon emission with a strong antibunching behavior i.e. g(2)(0) < 1 at high temperature up to 300 K is achieved. PMID:26828830

  1. Understanding the electrical behavior of the action potential in terms of elementary electrical sources.

    PubMed

    Rodriguez-Falces, Javier

    2015-03-01

    A concept of major importance in human electrophysiology studies is the process by which activation of an excitable cell results in a rapid rise and fall of the electrical membrane potential, the so-called action potential. Hodgkin and Huxley proposed a model to explain the ionic mechanisms underlying the formation of action potentials. However, this model is unsuitably complex for teaching purposes. In addition, the Hodgkin and Huxley approach describes the shape of the action potential only in terms of ionic currents, i.e., it is unable to explain the electrical significance of the action potential or describe the electrical field arising from this source using basic concepts of electromagnetic theory. The goal of the present report was to propose a new model to describe the electrical behaviour of the action potential in terms of elementary electrical sources (in particular, dipoles). The efficacy of this model was tested through a closed-book written exam. The proposed model increased the ability of students to appreciate the distributed character of the action potential and also to recognize that this source spreads out along the fiber as function of space. In addition, the new approach allowed students to realize that the amplitude and sign of the extracellular electrical potential arising from the action potential are determined by the spatial derivative of this intracellular source. The proposed model, which incorporates intuitive graphical representations, has improved students' understanding of the electrical potentials generated by bioelectrical sources and has heightened their interest in bioelectricity. PMID:25727465

  2. Analysis of Hydrogen Production from Renewable Electricity Sources: Preprint

    SciTech Connect

    Levene, J. I.; Mann, M. K.; Margolis, R.; Milbrandt, A.

    2005-09-01

    To determine the potential for hydrogen production via renewable electricity sources, three aspects of the system are analyzed: a renewable hydrogen resource assessment, a cost analysis of hydrogen production via electrolysis, and the annual energy requirements of producing hydrogen for refueling. The results indicate that ample resources exist to produce transportation fuel from wind and solar power. However, hydrogen prices are highly dependent on electricity prices.

  3. Auroral electron beams - Electric currents and energy sources

    NASA Astrophysics Data System (ADS)

    Kaufmann, R. L.

    1981-09-01

    The energy sources, electric equipotentials and electric currents associated with auroral electron acceleration observed during rocket flight 18:152 are discussed. Steep flow gradients at the interface between the convection boundary layer and the plasma sheet are considered as the probable source of energy for dayside and dawn and dusk auroras, while it is suggested that the cross tail potential drop may provide an energy source for some midnight auroras. Birkeland currents that flow along distorted field lines are shown possibly to be important in the mechanism that produces U-shaped equipotentials in the ionosphere, as well as unexpected jumps in ionospheric or magnetotail currents and unusual electric fields and plasma drift in the magnetotail. The production of equipotential structures under oppositely directed higher-altitude electric fields is discussed, and it is pointed out that cold ionospheric plasma can enter the structure in a cusp-shaped region where fields are weak. The rocket data reveals that the sudden change in conductivity at the edge of the bright arc and the constancy of the electric field produce sudden changes in the Hall and Pedersen currents. It is concluded that current continuity is satisfied primarily by east-west changes in the electric field or conductivity.

  4. Overview of electrochemical power sources for electric and hybrid-electric vehicles.

    SciTech Connect

    Dees, D. W.

    1999-02-12

    Electric and hybrid-electric vehicles are being developed and commercialized around the world at a rate never before seen. These efforts are driven by the prospect of vehicles with lower emissions and higher fuel efficiencies. The widespread adaptation of such vehicles promises a cleaner environment and a reduction in the rate of accumulation of greenhouse gases, Critical to the success of this technology is the use of electrochemical power sources such as batteries and fuel cells, which can convert chemical energy to electrical energy more efficiently and quietly than internal combustion engines. This overview will concentrate on the work being conducted in the US to develop advanced propulsion systems for the electric and hybrid vehicles, This work is spearheaded by the US Advanced Battery Consortium (USABC) for electric vehicles and the Partnership for a New Generation of Vehicle (PNGV) for hybrid-electric vehicles, both of which can be read about on the world wide web (www.uscar.tom). As is commonly known, electric vehicles rely strictly on batteries as their source of power. Hybrid-electric vehicles, however, have a dual source of power. An internal combustion engine or eventually a fuel cell supplies the vehicle with power at a relatively constant rate. A battery pack (much smaller than a typical electric-vehicle battery pack) provides the vehicle with its fast transient power requirements such as during acceleration. This hybrid arrangement maximizes vehicle fuel efficiency. Electric and hybrid-electric vehicles will also be able to convert the vehicle's change in momentum during braking into electrical energy and store it in its battery pack (instead of lose the energy as heat). This process, known as regenerative braking, will add to the vehicle's fuel efficiency in an urban environment.

  5. 46 CFR 28.375 - Emergency source of electrical power.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 1 2014-10-01 2014-10-01 false Emergency source of electrical power. 28.375 Section 28.375 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY UNINSPECTED VESSELS REQUIREMENTS FOR COMMERCIAL FISHING INDUSTRY VESSELS Requirements for Vessels Which Have Their Keel Laid or Are at a Similar Stage of Construction on or After or...

  6. 46 CFR 28.355 - Main source of electrical power.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 1 2014-10-01 2014-10-01 false Main source of electrical power. 28.355 Section 28.355 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY UNINSPECTED VESSELS REQUIREMENTS FOR COMMERCIAL FISHING INDUSTRY VESSELS Requirements for Vessels Which Have Their Keel Laid or Are at a Similar Stage of Construction on or After or Which Undergo...

  7. Largest College Endowments, 2011

    ERIC Educational Resources Information Center

    Chronicle of Higher Education, 2012

    2012-01-01

    Of all endowments valued at more than $250-million, the UCLA Foundation had the highest rate of growth over the previous year, at 49 percent. This article presents a table of the largest college endowments in 2011. The table covers the "rank," "institution," "market value as of June 30, 2011," and "1-year change" of institutions participating in…

  8. Electric machine and current source inverter drive system

    DOEpatents

    Hsu, John S

    2014-06-24

    A drive system includes an electric machine and a current source inverter (CSI). This integration of an electric machine and an inverter uses the machine's field excitation coil for not only flux generation in the machine but also for the CSI inductor. This integration of the two technologies, namely the U machine motor and the CSI, opens a new chapter for the component function integration instead of the traditional integration by simply placing separate machine and inverter components in the same housing. Elimination of the CSI inductor adds to the CSI volumetric reduction of the capacitors and the elimination of PMs for the motor further improve the drive system cost, weight, and volume.

  9. Simple voltage-controlled current source for wideband electrical bioimpedance spectroscopy: circuit dependences and limitations

    NASA Astrophysics Data System (ADS)

    Seoane, F.; Macías, R.; Bragós, R.; Lindecrantz, K.

    2011-11-01

    In this work, the single Op-Amp with load-in-the-loop topology as a current source is revisited. This circuit topology was already used as a voltage-controlled current source (VCCS) in the 1960s but was left unused when the requirements for higher frequency arose among the applications of electrical bioimpedance (EBI). The aim of the authors is not only limited to show that with the currently available electronic devices it is perfectly viable to use this simple VCCS topology as a working current source for wideband spectroscopy applications of EBI, but also to identify the limitations and the role of each of the circuit components in the most important parameter of a current for wideband applications: the output impedance. The study includes the eventual presence of a stray capacitance and also an original enhancement, driving with current the VCCS. Based on the theoretical analysis and experimental measurements, an accurate model of the output impedance is provided, explaining the role of the main constitutive elements of the circuit in the source's output impedance. Using the topologies presented in this work and the proposed model, any electronic designer can easily implement a simple and efficient current source for wideband EBI spectroscopy applications, e.g. in this study, values above 150 kΩ at 1 MHz have been obtained, which to the knowledge of the authors are the largest values experimentally measured and reported for a current source in EBI at this frequency.

  10. Radionuclide and electric accelerator sources for food irradiation

    NASA Astrophysics Data System (ADS)

    Lagunas-Solar, Manuel C.; Matthews, Stephen M.

    Radiation processing of food requires radiation sources with high intensity, penetrability, reliability, and the flexibility to be adapted to current food processing techniques. Current proposed regulations limit the radiation sources which can be utilized to radionuclides (i.e. 5.27-y Co-60; or 30.2-y Cs-137) or electrically-driven accelerators (i.e. X rays up to 5 MeV, electron beams up to 10 MeV). Therefore, the power; throughput; and use efficiency of these sources are important factors affecting the design; installation; operation; and economics of large-scale food-processing facilities. An analysis of the advantages and disadvantages of these sources is presented here, with special attention to the current status of both technologies, and with emphasis on the needs of the food-processing industry.

  11. Electrode configuration for extreme-UV electrical discharge source

    DOEpatents

    Spence, Paul Andrew; Fornaciari, Neal Robert; Chang, Jim Jihchyun

    2002-01-01

    It has been demonstrated that debris generation within an electric capillary discharge source, for generating extreme ultraviolet and soft x-ray, is dependent on the magnitude and profile of the electric field that is established along the surfaces of the electrodes. An electrode shape that results in uniform electric field strength along its surface has been developed to minimize sputtering and debris generation. The electric discharge plasma source includes: (a) a body that defines a circular capillary bore that has a proximal end and a distal end; (b) a back electrode positioned around and adjacent to the distal end of the capillary bore wherein the back electrode has a channel that is in communication with the distal end and that is defined by a non-uniform inner surface which exhibits a first region which is convex, a second region which is concave, and a third region which is convex wherein the regions are viewed outwardly from the inner surface of the channel that is adjacent the distal end of the capillary bore so that the first region is closest to the distal end; (c) a front electrode positioned around and adjacent to the proximal end of the capillary bore wherein the front electrode has an opening that is communication with the proximal end and that is defined by a non-uniform inner surface which exhibits a first region which is convex, a second region which is substantially linear, and third region which is convex wherein the regions are viewed outwardly from the inner surface of the opening that is adjacent the proximal end of the capillary bore so that the first region is closest to the proximal end; and (d) a source of electric potential that is connected across the front and back electrodes.

  12. Electrically Injected Photon-Pair Source at Room Temperature

    NASA Astrophysics Data System (ADS)

    Boitier, Fabien; Orieux, Adeline; Autebert, Claire; Lemaître, Aristide; Galopin, Elisabeth; Manquest, Christophe; Sirtori, Carlo; Favero, Ivan; Leo, Giuseppe; Ducci, Sara

    2014-05-01

    One of the main challenges for future quantum information technologies is the miniaturization and integration of high performance components in a single chip. In this context, electrically driven sources of nonclassical states of light have a clear advantage over optically driven ones. Here we demonstrate the first electrically driven semiconductor source of photon pairs working at room temperature and telecom wavelengths. The device is based on type-II intracavity spontaneous parametric down-conversion in an AlGaAs laser diode and generates pairs at 1.57 μm. Time-correlation measurements of the emitted pairs give an internal generation efficiency of 7×10-11 pairs/injected electron. The capability of our platform to support the generation, manipulation, and detection of photons opens the way to the demonstration of massively parallel systems for complex quantum operations.

  13. Scoping Calculations of Power Sources for Nuclear Electric Propulsion

    NASA Technical Reports Server (NTRS)

    Difilippo, F. C.

    1994-01-01

    This technical memorandum describes models and calculational procedures to fully characterize the nuclear island of power sources for nuclear electric propulsion. Two computer codes were written: one for the gas-cooled NERVA derivative reactor and the other for liquid metal-cooled fuel pin reactors. These codes are going to be interfaced by NASA with the balance of plant in order to make scoping calculations for mission analysis.

  14. Scoping calculations of power sources for nuclear electric propulsion

    SciTech Connect

    Difilippo, F.C.

    1994-05-01

    This technical memorandum describes models and calculational procedures to fully characterize the nuclear island of power sources for nuclear electric propulsion. Two computer codes were written: one for the gas-cooled NERVA derivative reactor and the other for liquid metal-cooled fuel pin reactors. These codes are going to be interfaced by NASA with the balance of plant in order to making scoping calculations for mission analysis.

  15. Electric Transport Traction Power Supply System With Distributed Energy Sources

    NASA Astrophysics Data System (ADS)

    Abramov, E. Y.; Schurov, N. I.; Rozhkova, M. V.

    2016-04-01

    The paper states the problem of traction substation (TSS) leveling of daily-load curve for urban electric transport. The circuit of traction power supply system (TPSS) with distributed autonomous energy source (AES) based on photovoltaic (PV) and energy storage (ES) units is submitted here. The distribution algorithm of power flow for the daily traction load curve leveling is also introduced in this paper. In addition, it illustrates the implemented experiment model of power supply system.

  16. Development of Electricity Generation from Renewable Energy Sources in Turkey

    NASA Astrophysics Data System (ADS)

    Kentel, E.

    2011-12-01

    Electricity is mainly produced from coal, natural gas and hydropower in Turkey. However, almost all the natural gas and high quality coal are imported. Thus, increasing the shares of both hydro and other renewables in energy supply is necessary to decrease dependency of the country on foreign sources. In 2008, the total installed capacity of Turkey was around 42000 MW and 66 % of this was from thermal sources. The remaining 33 % was from hydro, which leaves only one percent for the other renewable energy sources. The share of renewable energy in the energy budget of Turkey has increased in the last two decades; however, in 2008, only 17 % of the total electricity generation was realized from renewable sources most of which was hydro. According to State Hydraulic Works (SHW) which is the primary executive state agency responsible for the planning, operating and managing of Turkey's water resources, Turkey utilizes only around 35% of its economically viable hydro potential. The current situation clearly demonstrates the need for increasing the share of renewables in the energy budget. New laws, such as the Electricity Market Law, have been enacted and the following items were identified by the Ministry of Energy and Natural Resources of Turkey among primary energy policies and priorities: (i) decreasing dependency on foreign resources by prioritizing utilization of natural resources, (ii) increasing the share of renewable energy resources in the energy budget of Turkey; (iii) minimization of adverse environmental impacts of production and utilization of natural resources. The government's energy policy increased investments in renewable energy resources; however lack of a needed legal framework brought various environmental and social problems with this fast development. The development of the share of renewable resources in the energy budget, current government policy, and environmental concerns related with renewables, and ideas to improve the overall benefits of

  17. Annual input fluxes and source identification of trace elements in atmospheric deposition in Shanxi Basin: the largest coal base in China.

    PubMed

    Zhong, Cong; Yang, Zhongfang; Jiang, Wei; Yu, Tao; Hou, Qingye; Li, Desheng; Wang, Jianwu

    2014-11-01

    Industrialization and urbanization have led to a great deterioration of air quality and provoked some serious environmental concerns. One hundred and five samples of atmospheric deposition were analyzed for their concentrations of 13 trace elements (As, Cd, Cu, Fe, Al, Co, Cr, Hg, Mn, Mo, Pb, Se, and Zn) in Shanxi Basin, which includes six isolate basins. The input fluxes of the trace elements in atmospheric deposition were observed and evaluated. Geostatistical analysis (EF, PCA, and CA ) were conducted to determine the spatial distribution, possible sources, and enrichment degrees of trace elements in atmospheric deposition. Fe/Al and K/Al also contribute to identify the sources of atmospheric deposition. The distribution of trace elements in atmospheric deposition was proved to be geographically restricted. The results show that As, Cd, Pb, Zn, and Se mainly come from coal combustion. Fe, Cu, Mn, Hg, and Co originate mainly from interactions between local polluted soils and blowing dust from other places, while the main source of Al, Cr, and Mo are the soil parent materials without pollution. This work provides baseline information to develop policies to control and reduce trace elements, especially toxic elements, from atmospheric deposition. Some exploratory analytical methods applied in this work are also worth considering in similar researches. PMID:24929552

  18. EMISSIONS ASSESSMENT OF CONVENTIONAL STATIONARY SYSTEMS: VOLUME III. EXTERNAL COMBUSTION SOURCES FOR ELECTRICITY GENERATION

    EPA Science Inventory

    The report characterizes multimedia emissions from external combustion sources for electricity generation. Study results indicate that external combustion sources for electricity generation contribute significantly to the nationwide emissions burden. Flue gas emissions of NOx, SO...

  19. Electrical Conductivity Imaging Using Controlled Source Electromagnetics for Subsurface Characterization

    NASA Astrophysics Data System (ADS)

    Miller, C. R.; Routh, P. S.; Donaldson, P. R.

    2004-05-01

    Controlled Source Audio-Frequency Magnetotellurics (CSAMT) is a frequency domain electromagnetic (EM) sounding technique. CSAMT typically uses a grounded horizontal electric dipole approximately one to two kilometers in length as a source. Measurements of electric and magnetic field components are made at stations located ideally at least four skin depths away from the transmitter to approximate plane wave characteristics of the source. Data are acquired in a broad band frequency range that is sampled logarithmically from 0.1 Hz to 10 kHz. The usefulness of CSAMT soundings is to detect and map resistivity contrasts in the top two to three km of the Earth's surface. Some practical applications that CSAMT soundings have been used for include mapping ground water resources; mineral/precious metals exploration; geothermal reservoir mapping and monitoring; petroleum exploration; and geotechnical investigations. Higher frequency data can be used to image shallow features and lower frequency data are sensitive to deeper structures. We have a 3D CSAMT data set consisting of phase and amplitude measurements of the Ex and Hy components of the electric and magnetic fields respectively. The survey area is approximately 3 X 5 km. Receiver stations are situated 50 meters apart along a total of 13 lines with 8 lines bearing approximately N60E and the remainder of the lines oriented orthogonal to these 8 lines. We use an unconstrained Gauss-Newton method with positivity to invert the data. Inversion results will consist of conductivity versus depth profiles beneath each receiver station. These 1D profiles will be combined into a 3D subsurface conductivity image. We will include our interpretation of the subsurface conductivity structure and quantify the uncertainties associated with this interpretation.

  20. Dual radio frequency plasma source: Understanding via electrical asymmetry effect

    SciTech Connect

    Bora, B.; Bhuyan, H.; Favre, M.; Wyndham, E.; Wong, C. S.

    2013-04-21

    On the basis of the global model, the influences of driving voltage and frequency on electron heating in geometrically symmetrical dual capacitively coupled radio frequency plasma have been investigated. Consistent with the experimental and simulation results, non-monotonic behavior of dc self bias and plasma heating with increasing high frequency is observed. In addition to the local maxima of plasma parameters for the integer values of the ratio between the frequencies ({xi}), ourstudies also predict local maxima for odd integer values of 2{xi} as a consequence of the electrical asymmetry effect produced by dual frequency voltage sources.

  1. Chewing electric wire coatings: an unusual source of lead poisoning.

    PubMed

    Franco, G; Cottica, D; Minoia, C

    1994-02-01

    This report describes a case of lead poisoning occurring in an electrician as the result of an unusual personal habit, namely, the chewing of lead-containing coatings of electric wires. A coating chewing test showed that a few minutes after beginning chewing, saliva lead concentration increased from 10 micrograms/l to several milligrams per liter. This case is an example of poisoning caused by an occupationally related source (coatings containing lead) as a consequence of a singular and unconventional worker's habit. PMID:8147401

  2. World Spatiotemporal Analytics and Mapping Project (WSTAMP): Discovering, Exploring, and Mapping Spatiotemporal Patterns across the World s Largest Open Source Geographic Data Sets

    SciTech Connect

    Stewart, Robert N; Piburn, Jesse O; Sorokine, Alexandre; Myers, Aaron T; White, Devin A

    2015-01-01

    The application of spatiotemporal (ST) analytics to integrated data from major sources such as the World Bank, United Nations, and dozens of others holds tremendous potential for shedding new light on the evolution of cultural, health, economic, and geopolitical landscapes on a global level. Realizing this potential first requires an ST data model that addresses challenges in properly merging data from multiple authors, with evolving ontological perspectives, semantical differences, and changing attributes, as well as content that is textual, numeric, categorical, and hierarchical. Equally challenging is the development of analytical and visualization approaches that provide a serious exploration of this integrated data while remaining accessible to practitioners with varied backgrounds. The WSTAMP project at Oak Ridge National Laboratory has yielded two major results in addressing these challenges: 1) development of the WSTAMP database, a significant advance in ST data modeling that integrates 10,000+ attributes covering over 200 nation states spanning over 50 years from over 30 major sources and 2) a novel online ST exploratory and analysis tool providing an array of modern statistical and visualization techniques for analyzing these data temporally, spatially, and spatiotemporally under a standard analytic workflow. We discuss the status of this work and report on major findings. Acknowledgment Prepared by Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, Tennessee 37831-6285, managed by UT-Battelle, LLC for the U. S. Department of Energy under contract no. DEAC05-00OR22725. Copyright This manuscript has been authored by employees of UT-Battelle, LLC, under contract DE-AC05-00OR22725 with the U.S. Department of Energy. Accordingly, the United States Government retains and the publisher, by accepting the article for publication, acknowledges that the United States Government retains a non-exclusive, paid-up, irrevocable, world-wide license to publish or

  3. A silicon-based electrical source of surface plasmon polaritons

    NASA Astrophysics Data System (ADS)

    Walters, R. J.; van Loon, R. V. A.; Brunets, I.; Schmitz, J.; Polman, A.

    2010-01-01

    After decades of process scaling driven by Moore's law, the silicon microelectronics world is now defined by length scales that are many times smaller than the dimensions of typical micro-optical components. This size mismatch poses an important challenge for those working to integrate photonics with complementary metal oxide semiconductor (CMOS) electronics technology. One promising solution is to fabricate optical systems at metal/dielectric interfaces, where electromagnetic modes called surface plasmon polaritons (SPPs) offer unique opportunities to confine and control light at length scales below 100nm (refs 1, 2). Research groups working in the rapidly developing field of plasmonics have now demonstrated many passive components that suggest the potential of SPPs for applications in sensing and optical communication. Recently, active plasmonic devices based on III-V materials and organic materials have been reported. An electrical source of SPPs was recently demonstrated using organic semiconductors by Koller and colleagues. Here we show that a silicon-based electrical source for SPPs can be fabricated using established low-temperature microtechnology processes that are compatible with back-end CMOS technology.

  4. PREFACE: Diagnostics for electrical discharge light sources: pushing the limits Diagnostics for electrical discharge light sources: pushing the limits

    NASA Astrophysics Data System (ADS)

    Zissis, Georges; Haverlag, Marco

    2010-06-01

    Light sources play an indispensable role in the daily life of any human being. Quality of life, health and urban security related to traffic and crime prevention depend on light and on its quality. In fact, every day approximately 30 billion electric light sources operate worldwide. These electric light sources consume almost 19% of worldwide electricity production. Finding new ways to light lamps is a challenge where the stakes are scientific, technological, economic and environmental. The production of more efficient light sources is a sustainable solution for humanity. There are many opportunities for not only enhancing the efficiency and reliability of lighting systems but also for improving the quality of light as seen by the end user. This is possible through intelligent use of new technologies, deep scientific understanding of the operating principles of light sources and knowledge of the varied human requirements for different types of lighting in different settings. A revolution in the domain of light source technology is on the way: high brightness light emitting diodes arriving in the general lighting market, together with organic LEDs (OLEDs), are producing spectacular advances. However, unlike incandescence, electrical discharge lamps are far from disappearing from the market. In addition, new generations of discharge lamps based on molecular radiators are becoming a reality. There are still many scientific and technological challenges to be raised in this direction. Diagnostics are important for understanding the fundamental mechanisms taking place in the discharge plasma. This understanding is an absolute necessity for system optimization leading to more efficient and high quality light sources. The studied medium is rather complex, but new diagnostic techniques coupled to innovative ideas and powerful tools have been developed in recent years. This cluster issue of seven papers illustrates these efforts. The selected papers cover all domains, from

  5. Electrical energy sources for organic synthesis on the early Earth.

    PubMed

    Chyba, C; Sagan, C

    1991-01-01

    In 1959, Miller and Urey (Science 130, 245) published their classic compilation of energy sources for indigenous prebiotic organic synthesis on the early Earth. Much contemporary origins of life research continues to employ their original estimates for terrestrial energy dissipation by lightning and coronal discharges, 2 x 10(19) J yr-1 and 6 x 10(19) J yr-1, respectively. However, more recent work in terrestrial lightning and point discharge research suggests that these values are overestimates by factors of about 20 and 120, respectively. Calculated concentrations of amino acids (or other prebiotic organic products) in the early terrestrial oceans due to electrical discharge sources may therefore have been equally overestimated. A review of efficiencies for those experiments that provide good analogues to naturally-occurring lightning and coronal discharges suggests that lightning energy yields for organic synthesis (nmole J-1) are about one order of magnitude higher than those for coronal discharge. Therefore organic production by lightning may be expected to have dominated that due to coronae on early Earth. Limited data available for production of nitric oxide in clouds suggests that coronal emission within clouds, a source of energy heretofore too uncertain to be included in the total coronal energy inventory, is insufficient to change this conclusion. Our recommended values for lightning and coronal discharge dissipation rates on the early Earth are, respectively, 1 x 10(18) J yr-1 and 5 x 10(17) J yr-1. PMID:11537539

  6. Electrical energy sources for organic synthesis on the early earth

    NASA Astrophysics Data System (ADS)

    Chyba, Christopher; Sagan, Carl

    1991-01-01

    In 1959, Miller and Urey (Science 130, 245) published their classic compilation of energy sources for indigenous prebiotic organic synthesis on the early Earth. Much contemporary origins of life research continues to employ their original estimates for terrestrial energy dissipation by lightning and coronal discharges, 2 × 1019 J yr-1 and 6 × 1019 J yr-1, respectively. However, more recent work in terrestrial lightning and point discharge research suggests that these values are overestimates by factors of about 20 and 120, respectively. Calculated concentrations of amino acids (or other prebiotic organic products) in the early terrestrial oceans due to electrical discharge sources may therefore have been equally overestimated. A review of efficiencies for those experiments that provide good analogues to naturally-occurring lightning and coronal discharges suggests that lightning energy yields for organic synthesis (nmole J-1) are about one order of magnitude higher than those for coronal discharge. Therefore organic production by lightning may be expected to have dominated that due to coronae on early Earth. Limited data available for production of nitric oxide in clouds suggests that coronal emission within clouds, a source of energy heretofore too uncertain to be included in the total coronal energy inventory, is insufficient to change this conclusion. Our recommended valves for lightning and coronal discharge dissipation rates on the early Earth are, respectively, 1 × 1018 J yr-1 and 5 × 1017 J yr-1.

  7. Saturn's largest ring.

    PubMed

    Verbiscer, Anne J; Skrutskie, Michael F; Hamilton, Douglas P

    2009-10-22

    Most planetary rings in the Solar System lie within a few radii of their host body, because at these distances gravitational accelerations inhibit satellite formation. The best known exceptions are Jupiter's gossamer rings and Saturn's E ring, broad sheets of dust that extend outward until they fade from view at five to ten planetary radii. Source satellites continuously supply the dust, which is subsequently lost in collisions or by radial transport. Here we report that Saturn has an enormous ring associated with its outer moon Phoebe, extending from at least 128R(S) to 207R(S) (Saturn's radius R(S) is 60,330 km). The ring's vertical thickness of 40R(S) matches the range of vertical motion of Phoebe along its orbit. Dynamical considerations argue that these ring particles span the Saturnian system from the main rings to the edges of interplanetary space. The ring's normal optical depth of approximately 2 x 10(-8) is comparable to that of Jupiter's faintest gossamer ring, although its particle number density is several hundred times smaller. Repeated impacts on Phoebe, from both interplanetary and circumplanetary particle populations, probably keep the ring populated with material. Ring particles smaller than centimetres in size slowly migrate inward and many of them ultimately strike the dark leading face of Iapetus. PMID:19812546

  8. 46 CFR 190.05-15 - Segregation of spaces containing the emergency source of electric power.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... electric power. 190.05-15 Section 190.05-15 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY... Segregation of spaces containing the emergency source of electric power. (a) When a compartment containing the emergency source of electric power, or vital components thereof, adjoins a space containing either the...

  9. 46 CFR 190.05-15 - Segregation of spaces containing the emergency source of electric power.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... electric power. 190.05-15 Section 190.05-15 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY... Segregation of spaces containing the emergency source of electric power. (a) When a compartment containing the emergency source of electric power, or vital components thereof, adjoins a space containing either the...

  10. 46 CFR 190.05-15 - Segregation of spaces containing the emergency source of electric power.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... electric power. 190.05-15 Section 190.05-15 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY... Segregation of spaces containing the emergency source of electric power. (a) When a compartment containing the emergency source of electric power, or vital components thereof, adjoins a space containing either the...

  11. 46 CFR 92.05-15 - Segregation of spaces containing the emergency source of electric power.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... electric power. 92.05-15 Section 92.05-15 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED... Segregation of spaces containing the emergency source of electric power. (a) The provisions of this section... the emergency source of electric power, or vital components thereof, adjoins a space containing...

  12. 46 CFR 92.05-15 - Segregation of spaces containing the emergency source of electric power.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... electric power. 92.05-15 Section 92.05-15 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED... Segregation of spaces containing the emergency source of electric power. (a) The provisions of this section... the emergency source of electric power, or vital components thereof, adjoins a space containing...

  13. 46 CFR 190.05-15 - Segregation of spaces containing the emergency source of electric power.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... electric power. 190.05-15 Section 190.05-15 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY... Segregation of spaces containing the emergency source of electric power. (a) When a compartment containing the emergency source of electric power, or vital components thereof, adjoins a space containing either the...

  14. 46 CFR 92.05-15 - Segregation of spaces containing the emergency source of electric power.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... electric power. 92.05-15 Section 92.05-15 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED... Segregation of spaces containing the emergency source of electric power. (a) The provisions of this section... the emergency source of electric power, or vital components thereof, adjoins a space containing...

  15. 46 CFR 92.05-15 - Segregation of spaces containing the emergency source of electric power.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... electric power. 92.05-15 Section 92.05-15 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED... Segregation of spaces containing the emergency source of electric power. (a) The provisions of this section... the emergency source of electric power, or vital components thereof, adjoins a space containing...

  16. 48 CFR 217.175 - Multiyear contracts for electricity from renewable energy sources.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... electricity from renewable energy sources. 217.175 Section 217.175 Federal Acquisition Regulations System... SPECIAL CONTRACTING METHODS Mulityear Contracting 217.175 Multiyear contracts for electricity from... not to exceed 10 years for the purchase of electricity from sources of renewable energy, as that...

  17. 48 CFR 217.174 - Multiyear contracts for electricity from renewable energy sources.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... electricity from renewable energy sources. 217.174 Section 217.174 Federal Acquisition Regulations System... SPECIAL CONTRACTING METHODS Mulityear Contracting 217.174 Multiyear contracts for electricity from... not to exceed 10 years for the purchase of electricity from sources of renewable energy, as that...

  18. 46 CFR 92.05-15 - Segregation of spaces containing the emergency source of electric power.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... the emergency source of electric power, or vital components thereof, adjoins a space containing either... rise in the space containing the emergency source of electric power, or vital components thereof, for a... electric power. 92.05-15 Section 92.05-15 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY...

  19. 46 CFR 190.05-15 - Segregation of spaces containing the emergency source of electric power.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... emergency source of electric power, or vital components thereof, adjoins a space containing either the ship... space containing the emergency source of electric power, or vital components thereof, for a period of at... electric power. 190.05-15 Section 190.05-15 Shipping COAST GUARD, DEPARTMENT OF HOMELAND...

  20. Inertial electrostatic confinement as a power source for electric propulsion

    NASA Technical Reports Server (NTRS)

    Miley, G. H.; Burton, R.; Javedani, J.; Yamamoto, Y.; Satsangi, A; Gu, Y.; Heck, P.; Nebel, R.; Schulze, N.; Christensen, J.

    1993-01-01

    The potential use of an INERTIAL ELECTROSTATIC CONFINEMENT (IEC) power source for space propulsion has previously been suggested by the authors and others. In the past, these discussions have generally followed the charged-particle electric-discharge engine (QED) concept proposed by Bussard, in which the IEC is used to generate an electron beam which vaporizes liquid hydrogen for use as a propellant. However, an alternate approach is considered, using the IEC to drive a 'conventional' electric thruster unit. This has the advantage of building on the rapidly developing technology for such thrusters, which operate at higher specific impulse. Key issues related to this approach include the continued successful development of the physics and engineering of the IEC unit, as well as the development of efficient step-down dc voltage transformers. The IEC operates by radial injection of energetic ions into a spherical vessel. A very high ion density is created in a small core region at the center of the vessel, resulting in extremely high fusion power density in the core. Experiments at the U. of Illinois in small IEC devices (is less than 60 cm. dia.) demonstrated much of the basic physics underlying this concept, e.g. producing 10(exp 6) D-D neutrons/sec steady-state with deuterium gas flow injection. The ultimate goal is to increase the power densities by several orders of magnitude and to convert to D-He-3 injection. If successful, such an experiment would represent a milestone proof-of-principle device for eventual space power use. Further discussion of IEC physics and status are presented with a description of the overall propulsion system and estimated performance.

  1. Inertial electrostatic confinement as a power source for electric propulsion

    NASA Technical Reports Server (NTRS)

    Miley, George H.; Burton, R.; Javedani, J.; Yamamoto, Y.; Satsangi, A.; Gu, Y.; Heck, P.; Nebel, R.; Schulze, N.; Christensen, J.

    1993-01-01

    The potential use of an Inertial Electrostatic Confinement (IEC) power source for space propulsion has previously been suggested by the authors and others. In the past, these discussions have generally followed the charged-particle electric-discharge engine (QED) concept proposed by Bussard, in which the IEC is used to generate an electron beam which vaporizes liquid hydrogen for use as a propellant. However, in the present study, we consider an alternate approach, using the IEC to drive a conventional electric thruster unit. This has the advantage of building on the rapidly developing technology for such thrusters, which operate at higher specific impulse. Key issues related to this approach include the continued successful development of the physics and engineering of the IEC unit, as well as the development of efficient step-down dc voltage transformers. The IEC operates by radial injection of energetic ions into a spherical vessel. A very high ion density is created in a small core region at the center of the vessel, resulting in extremely high fusion power density in the core. Present experiments at the U. of Illinois in small IEC devices (less than 60-cm. dia.) have demonstrated much of the basic physics underlying this concept, e.g. producing approximately 10(exp 6) D-D neutrons/sec steady-state with deuterium gas flow injection. The ultimate goal is to increase the power densities by several orders of magnitude and to convert to D-He-3 injection. If successful, such an experiment would represent a milestone proof-of-principle device for eventual space power use. Further discussion of IEC physics and status will be presented with a description of the overall propulsion system and estimated performance.

  2. 48 CFR 217.174 - Multiyear contracts for electricity from renewable energy sources.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... electricity from renewable energy sources. 217.174 Section 217.174 Federal Acquisition Regulations System... renewable energy sources. (a) The head of the contracting activity may enter into a contract for a period not to exceed 10 years for the purchase of electricity from sources of renewable energy, as that...

  3. 48 CFR 217.174 - Multiyear contracts for electricity from renewable energy sources.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... electricity from renewable energy sources. 217.174 Section 217.174 Federal Acquisition Regulations System... renewable energy sources. (a) The head of the contracting activity may enter into a contract for a period not to exceed 10 years for the purchase of electricity from sources of renewable energy, as that...

  4. 48 CFR 217.174 - Multiyear contracts for electricity from renewable energy sources.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... electricity from renewable energy sources. 217.174 Section 217.174 Federal Acquisition Regulations System... renewable energy sources. (a) The head of the contracting activity may enter into a contract for a period not to exceed 10 years for the purchase of electricity from sources of renewable energy, as that...

  5. High electric field deuterium ion sources for neutron generators

    NASA Astrophysics Data System (ADS)

    Reichenbach, Birk

    Active interrogation systems for highly enriched uranium require improved fieldable neutron sources. The target technology for deuterium-tritium neutron generators is well understood and the most significant improvement can be achieved by improving the deuterium ion source through increased output and, in some cases, lifetime of the ion source. We are developing a new approach to a deuterium ion sources based upon the field desorption/evaporation of deuterium from the surfaces of metal tips. Electrostatic field desorption (EFD) desorbs previously adsorbed deuterium as ions under the influence of high electric fields (several V/A), without removing tip material. Single etched wire tip experiments have been performed and have shown that this is difficult but can be achieved with molybdenum and tungsten tips. Electrostatic field evaporation (EFE) evaporates ultra thin deuterated titanium films as ions. It has been shown that several 10s of atomic layers can be removed within a few nanoseconds from etched tungsten tips. In the course of these studies titanium deposition and deuteration methods were studied and new detection methods developed. Space charge effects resulting from the large ion currents were identified to be the most likely cause of some unusual ion emission characteristics. In addition, on W < 110 > oriented substrates a surprising body-centered cubic crystal structure of the titanium film was found and studied. The ion currents required for neutron generator applications can be achieved by microfabrication of metal tip arrays. Field desorption studies of microfabricated field emitter tip arrays have been conducted for the first time. Maximum fields of 3 V/A have been applied to the array tip surfaces to date, although fields of ˜ 2 V/A to ˜ 2.5 V/A are more typical. Desorption of atomic deuterium ions has been observed at fields of roughly 2 V/A at room temperature. The desorption of common surface adsorbates, such as hydrogen, carbon, water, and

  6. Rehabilitating China's largest inland river.

    PubMed

    Li, Yiqing; Chen, Yaning; Zhang, Yaoqi; Xia, Yang

    2009-06-01

    Wetlands are particularly important for conserving China's biodiversity but riparian wetlands in the Tarim River basin in western China have been reduced by 46% during the last 3 decades. The world's largest habitat for Populus euphratica, which is in the Tarim River basin, significantly shrank. To protect and restore the deteriorated ecosystems along the Tarim River and its associated wetlands, China's government initiated a multimillion dollar river restoration project to release water from upper dams to the dried-up lower reaches of the Tarim River starting in 2000. We monitored the responses of groundwater and vegetation to water recharge in the lower reaches of the river from 2000 to 2006 by establishing nine 1000-m-long transects perpendicular to the river at intervals of 20-45 km along the 320-km river course below the Daxihaizi Reservoir, the source of water conveyance, to Lake Taitema, the terminus of the Tarim River. Water recharges from the Daxihaizi Reservoir to the lower reaches of the Tarim River significantly increased groundwater levels and vegetation coverage at all monitoring sites along the river. The mean canopy size of the endangered plant species P. euphratica doubled after 6 years of water recharge. Some rare migrating birds returned to rest on the restored wetlands in summer along the lower reaches of the Tarim River. The biggest challenge facing decision makers, however, is to balance water allocation and water rights between agricultural and natural ecosystems in a sustainable way. A large number of inhabitants in the Tarim Basin depend on these limited water resources for a living. At the same time, the endangered ecosystems need to be protected. Given the ecological, socioeconomic, and sociopolitical realities in the Tarim Basin, adaptive water policies and strategies are needed for water allocation in these areas of limited water resources. PMID:22748091

  7. Ultrafast electrical control of a resonantly driven single photon source

    SciTech Connect

    Cao, Y.; Bennett, A. J. Ellis, D. J. P.; Shields, A. J.; Farrer, I.; Ritchie, D. A.

    2014-08-04

    We demonstrate generation of a pulsed stream of electrically triggered single photons in resonance fluorescence, by applying high frequency electrical pulses to a single quantum dot in a p-i-n diode under resonant laser excitation. Single photon emission was verified, with the probability of multiple photon emission reduced to 2.8%. We show that despite the presence of charge noise in the emission spectrum of the dot, resonant excitation acts as a “filter” to generate narrow bandwidth photons.

  8. The source of the electric field in the nightside magnetosphere

    NASA Technical Reports Server (NTRS)

    Stern, D. P.

    1975-01-01

    In the open magnetosphere model magnetic field lines from the polar caps connect to the interplanetary magnetic field and conduct an electric field from interplanetary space to the polar ionosphere. By examining the magnetic flux involved it is concluded that only slightly more than half of the magnetic flux in the polar caps belongs to open field lines and that such field lines enter or leave the magnetosphere through narrow elongated windows stretching the tail. These window regions are identified with the tail's boundary region and shift their position with changes in the interplanetary magnetic field, in particular when a change of interplanetary magnetic sector occurs. The circuit providing electric current in the magnetopause and the plasma sheet is extended across those windows; thus energy is drained from the interplanetary electric field and an electric potential drop is produced across the plasma sheet. The polar cap receives its electric field from interplanetary space on the day side from open magnetic field lines and on the night side from closed field lines leading to the plasma sheet. The theory described provides improved understanding of magnetic flux bookkeeping, of the origin of Birkeland currents, and of the boundary layer of the geomagnetic tail.

  9. A focused electric spark source for non-contact stress wave excitation in solids.

    PubMed

    Dai, Xiaowei; Zhu, Jinying; Haberman, Michael R

    2013-12-01

    A focused electric spark is used as a non-contact acoustic source to excite stress waves in solids. The source consists of an electric spark source located at the near focus of an ellipsoidal reflector that focuses the acoustic disturbance generated by the spark source to the far focal point. Experimental studies using both contact and non-contact sensors indicate that the source has the capability to excite the Rayleigh surface wave and impact-echo mode (S1-zero-group-velocity Lamb mode) in a 250 mm thick concrete slab and to enable fully air-coupled testing of concrete specimens. PMID:25669297

  10. Control of new energy sources in an electric utility system

    NASA Technical Reports Server (NTRS)

    Kirkham, H.

    1981-01-01

    The addition of generators based on renewable resources to the electric power system brings new problems of control and communication if the generators are to be controlled as an integrated part of the power system. Since many of these generators are small, it will require a large number of them, connected to the distribution system, to represent an appreciable fraction of the total generation. This situation contrasts with present day generation control which typically involves only the control of a small number of large generators. This paper examines the system requirements for integrated control, and proposes a control arrangement in which the incremental cost of power is an important parameter.

  11. Method and apparatus for debris mitigation for an electrical discharge source

    DOEpatents

    Klebanoff, Leonard E.; Rader, Daniel J.; Silfvast, William T.

    2006-01-24

    Method and apparatus for mitigating the transport of debris generated and dispersed from electric discharge sources by thermophoretic and electrostatic deposition. A member is positioned adjacent the front electrode of an electric discharge source and used to establish a temperature difference between it and the front electrode. By flowing a gas between the member and the front electrode a temperature gradient is established that can be used for thermophoretic deposition of particulate debris on either the member or front electrode depending upon the direction of the thermal gradient. Establishing an electric field between the member and front electrode can aid in particle deposition by electrostatic deposition.

  12. Metod And Apparatus For Debris Mitigation For An Electrical Discharge Source

    DOEpatents

    Klebanoff, Leonard E.; Silfvast, William T.; Rader, Daniel J.

    2005-05-03

    Method and apparatus for mitigating the transport of debris generated and dispersed from electric discharge sources by thermophoretic and electrostatic deposition. A member is positioned adjacent the front electrode of an electric discharge source and used to establish a temperature difference between it and the front electrode. By flowing a gas between the member and the front electrode a temperature gradient is established that can be used for thermophoretic deposition of particulate debris on either the member or front electrode depending upon the direction of the thermal gradient. Establishing an electric field between the member and front electrode can aid in particle deposition by electrostatic deposition.

  13. Diversity of fuel sources for electricity generation in an evolving U.S. power sector

    NASA Astrophysics Data System (ADS)

    DiLuccia, Janelle G.

    Policymakers increasingly have shown interest in options to boost the relative share of renewable or clean electricity generating sources in order to reduce negative environmental externalities from fossil fuels, guard against possible resource constraints, and capture economic advantages from developing new technologies and industries. Electric utilities and non-utility generators make decisions regarding their generation mix based on a number of different factors that may or may not align with societal goals. This paper examines the makeup of the electric power sector to determine how the type of generator and the presence (or lack) of competition in electricity markets at the state level may relate to the types of fuel sources used for generation. Using state-level electricity generation data from the U.S. Energy Information Administration from 1990 through 2010, this paper employs state and time fixed-effects regression modeling to attempt to isolate the impacts of state-level restructuring policies and the emergence of non-utility generators on states' generation from coal, from fossil fuel and from renewable sources. While the analysis has significant limitations, I do find that state-level electricity restructuring has a small but significant association with lowering electricity generation from coal specifically and fossil fuels more generally. Further research into the relationship between competition and fuel sources would aid policymakers considering legislative options to influence the generation mix.

  14. Reliable compact electrical power source systems for space launch vehicles

    SciTech Connect

    Young, A.R.

    1996-12-31

    Described herein are several key technologies utilized in the design of a family of direct-drive turboalternator systems for space launch vehicles. These systems automatically provide conditioned and regulated electrical power at various voltages, powering actuators, valves, and avionics throughout the vehicle. The simple and robust ring-wound two-pole toothless alternator operates at peripheral speeds, making it suitable to be driven directly by a turbine, thereby eliminating the weight, reliability, zero ``g`` lubrication, and cooling issues of a speed-reducing gearbox, while allowing the turbine to operate at reasonable efficiency. Additionally, the use of self-aligning foil bearing and catalytic combustors or cold gas propellants enhance the reliability. The power conditioner and electronic controller provide hands-off regulated ac or dc power on demand, maintaining critical parameters within established limits and performance while reporting on built-in health-monitoring tests.

  15. Largest impact craters on Venus

    NASA Technical Reports Server (NTRS)

    Ivanov, B. A.; Weitz, C. M.; Basilevsky, A. T.

    1992-01-01

    High-resolution radar images from the Magellan spacecraft have allowed us to perform a detailed study on 25 large impact craters on Venus with diameters from 70 to 280 km. The dimension of these large craters is comparable with the characteristic thickness of the venusian lithosphere and the atmospheric scale height. Some physical parameters for the largest impact craters on Venus (LICV), such as depth, ring/diameter ratio, and range of ballistic ejecta deposits, have been obtained from the SAR images and the altimetry dataset produced by MIT. Data related to each of these parameters is discussed.

  16. Understanding the Electrical Behavior of the Action Potential in Terms of Elementary Electrical Sources

    ERIC Educational Resources Information Center

    Rodriguez-Falces, Javier

    2015-01-01

    A concept of major importance in human electrophysiology studies is the process by which activation of an excitable cell results in a rapid rise and fall of the electrical membrane potential, the so-called action potential. Hodgkin and Huxley proposed a model to explain the ionic mechanisms underlying the formation of action potentials. However,…

  17. 46 CFR 32.60-45 - Segregation of spaces containing the emergency source of electric power-TB/ALL.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... electric power-TB/ALL. 32.60-45 Section 32.60-45 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY TANK... On or After July 1, 1951 § 32.60-45 Segregation of spaces containing the emergency source of electric... October 1, 1958. (b) When a compartment containing the emergency source of electric power, or...

  18. Design and Construction of a High Voltage Pulsed Source for Electric Excitation of the Gas Laser

    NASA Astrophysics Data System (ADS)

    Díaz, Xavier Daza; Neira, Oscar León B.; Díaz-Pérez, H. Abraham

    2008-04-01

    In this paper, the design, construction and implementation of High Voltage Pulsed Source for Electrical Excitation of the Gas Lasers, as a first phase of the research project "Design and Construction of an economically and reliable Laser System constituted by a molecular pulsed laser and a single optical head for dyes" is presented. We proposed and considered the design and the construction of a source of pulsed high voltage that adjusts to the requirements of the pumping system that requires a low pressure nitrogen laser. The design and construction of the source high voltage prototype is presented like part of the electrical pumping system for a Pulsed Nitrogen Laser. The electrical pumping System is conformed by three subsystems: the high pulsed regulated voltage Source, the storage and unloading system of electrical energy of active medium, and the frequency control system of discharge repetition (spark gap) constituted by a circuit RLC and the electrodes of the laser discharge tube. In the present work the aspects related to the pulsed high regulated voltage Source is presented, Our Source of high pulsed voltage is constituted by four fundamental stages: the Stage of Conversion AC-DC (voltage reducer), the Stage of Commutation by means of a Insulated Gate Bipolar Transistor (IGBT), the stage of Generation of signal modulated by the pulses width "PWM" (with base to Circuit TL 494) and the Stage of Elevation of Voltage (using a FlyBack Transformer).

  19. Noninvasive functional cardiac electrical source imaging: combining MRI and ECG mapping for imaging electrical function

    NASA Astrophysics Data System (ADS)

    Tilg, Bernhard; Modre, Robert; Fischer, Gerald; Hanser, Friedrich; Messnarz, Bernd; Schocke, Michael F. H.; Kremser, Christian; Roithinger, Franz

    2002-04-01

    Inverse electrocardiography has been developing for several years. By coupling electrocardiographic mapping and 3D+time anatomical data, the electrical excitation sequence can be imaged completely noninvasively in the human heart. In this study, a bidomain theory based surface heart model activation time imaging approach was applied to single beat data of atrial and ventricular depolarization. For sinus and paced rhythms, the sites of early activation and the areas with late activation were estimated with sufficient accuracy. In particular for focal arrhythmias, this model-based imaging approach might allow the guidance and evaluation of antiarrhythmic interventions, for instance, in case of catheter ablation or drug therapy.

  20. Electromagnetic induction by finite wavenumber source fields in 2-D lateral heterogeneities - The transverse electric mode

    NASA Technical Reports Server (NTRS)

    Hermance, J. F.

    1984-01-01

    Electromagnetic induction in a laterally homogeneous earth is analyzed in terms of a source field with finite dimensions. Attention is focused on a time-varying two-dimensional current source directed parallel to the strike of a two-dimensional anomalous structure within the earth, i.e., the E-parallel mode. The spatially harmonic source field is expressed as discontinuities in the magnetic (or electric) field of the current in the source. The model is applied to describing the magnetic gradients across megatectonic features, and may be used to predict the magnetic fields encountered by a satellite orbiting above the ionosphere.

  1. 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)

  2. Characterization of the atmospheric electrical environment near a corona ion-emitting source

    NASA Astrophysics Data System (ADS)

    J-Fatokun, F. O.; Jayaratne, E. R.; Morawska, L.; Rachman, R.; Birtwhistle, D.; Mengersen, K.

    Presence of high concentrations of corona ions in any air environment cause changes in the earth's natural dc e-field; while their interaction with airborne aerosols produce charged particles. The charged particles and ions are dispersed by wind, and depending on the prevailing meteorology, their presence can be observed several hundreds of metres from the ion source. This paper presents a study characterizing the electrical environment of a strong substantially constant source of corona ions (a high voltage electricity substation). Results of the study showed that corona ion and particle charge concentrations as well as their associated effect on the vertical dc e-field perturbations decreased with distance from the emitting source. Mean particle charge concentration in the air environment of the ion-emitting source (-1750±745 ions cm -3) was three times higher than that of an urban outdoor air and 17 times that of a mechanically ventilated room. Statistical investigation of possible associations between parameters showed strong associations ( R2=74%, p<0.05) between particle charge and ion concentration; and 54% correlation between particle charge and magnitude of the vertical dc e-field (mean value of -285±51 V m -1). Although a source of ambient electrical charge, the electricity substation was not a significant generator of aerosol particles within the size range (0.02-1 μm) examined in this study.

  3. Source of electrical power for an electric vehicle and other purposes, and related methods

    DOEpatents

    LaFollette, Rodney M.

    2002-11-12

    Microthin sheet technology is disclosed by which superior batteries are constructed which, among other things, accommodate the requirements for high load rapid discharge and recharge, mandated by electric vehicle criteria. The microthin sheet technology has process and article overtones and can be used to form corrugated thin electrodes used in batteries of various kinds and types, such as spirally-wound batteries, bipolar batteries, lead acid batteries, silver/zinc batteries, and others. Superior high performance battery features include: (a) minimal ionic resistance; (b) minimal electronic resistance; (c) minimal polarization resistance to both charging and discharging; (d) improved current accessibility to active material of the electrodes; (e) a high surface area to volume ratio; (f) high electrode porosity (microporosity); (g) longer life cycle; (h) superior discharge/recharge characteristics; (i) higher capacities (A.multidot.hr); and (j) high specific capacitance.

  4. Source of electrical power for an electric vehicle and other purposes, and related methods

    DOEpatents

    LaFollette, Rodney M.

    2000-05-16

    Microthin sheet technology is disclosed by which superior batteries are constructed which, among other things, accommodate the requirements for high load rapid discharge and recharge, mandated by electric vehicle criteria. The microthin sheet technology has process and article overtones and can be used to form thin electrodes used in batteries of various kinds and types, such as spirally-wound batteries, bipolar batteries, lead acid batteries, silver/zinc batteries, and others. Superior high performance battery features include: (a) minimal ionic resistance; (b) minimal electronic resistance; (c) minimal polarization resistance to both charging and discharging; (d) improved current accessibility to active material of the electrodes; (e) a high surface area to volume ratio; (f) high electrode porosity (microporosity); (g) longer life cycle; (h) superior discharge/recharge characteristics; (j) higher capacities (A.multidot.hr); and k) high specific capacitance.

  5. Demonstration of a possible source of error with an electric pulp tester.

    PubMed

    Myers, J W

    1998-03-01

    The purpose of this study was to determine whether electrical current can travel between adjacent teeth through contacting interproximal amalgam restorations. Twenty-two extracted human premolars were restored with class II amalgam restorations. They were then mounted in pairs in self-curing resin, simulating adjacent teeth. Only their restorations were allowed to contact. An electrical multimeter was used to supply electrical current and to measure any current passing through the mounted teeth. One current measurement was made from the buccal enamel of a tooth to the occlusal surface of the filling in that tooth. A second measurement was made from the buccal enamel of the same tooth to the occlusal surface of the adjacent filling. These two measurements were made for all 11 trials. Statistically, all current that entered the first tooth passed to the adjacent tooth. This finding suggests a potential source of error when using an electric pulp tester. PMID:9558588

  6. Electrical shielding box measurement of the negative hydrogen beam from Penning ion gauge ion source

    SciTech Connect

    Wang, T.; Yang, Z.; Dong, P.; Long, J. D.; He, X. Z.; Zhang, K. Z.; Zhang, L. W.; Wang, X.

    2012-06-15

    The cold-cathode Penning ion gauge (PIG) type ion source has been used for generation of negative hydrogen (H{sup -}) ions as the internal ion source of a compact cyclotron. A novel method called electrical shielding box dc beam measurement is described in this paper, and the beam intensity was measured under dc extraction inside an electrical shielding box. The results of the trajectory simulation and dc H{sup -} beam extraction measurement were presented. The effect of gas flow rate, magnetic field strength, arc current, and extraction voltage were also discussed. In conclusion, the dc H{sup -} beam current of about 4 mA from the PIG ion source with the puller voltage of 40 kV and arc current of 1.31 A was extrapolated from the measurement at low extraction dc voltages.

  7. Electrical shielding box measurement of the negative hydrogen beam from Penning ion gauge ion source

    NASA Astrophysics Data System (ADS)

    Wang, T.; Yang, Z.; Dong, P.; long, J. D.; He, X. Z.; Wang, X.; Zhang, K. Z.; Zhang, L. W.

    2012-06-01

    The cold-cathode Penning ion gauge (PIG) type ion source has been used for generation of negative hydrogen (H-) ions as the internal ion source of a compact cyclotron. A novel method called electrical shielding box dc beam measurement is described in this paper, and the beam intensity was measured under dc extraction inside an electrical shielding box. The results of the trajectory simulation and dc H- beam extraction measurement were presented. The effect of gas flow rate, magnetic field strength, arc current, and extraction voltage were also discussed. In conclusion, the dc H- beam current of about 4 mA from the PIG ion source with the puller voltage of 40 kV and arc current of 1.31 A was extrapolated from the measurement at low extraction dc voltages.

  8. Complementary Detection of Multiple Electrical Sources in Tissue Using Acoustoelectric Effects.

    PubMed

    Wang, Zhaohui; Challoo, Rajab; Peng, Hu; Leung, Chung S; Witte, Russell S

    2016-09-01

    Accurate 3-D mapping of multiple bioelectric sources in nerve fibers with high spatial resolution is challenging for the diagnosis and treatment of a variety of neural abnormalities. Ultrasound current source density imaging exploits the acoustoelectric (AE) effect, an interaction between electrical current and acoustic pressure waves propagating through a conducting material, and has distinct advantages over conventional electrophysiology (i.e., without ultrasound) for mapping electrical current flow in tissue. Ultrasound current source density imaging and two complementary Wheatstone bridge circuits were used to simultaneously detect two separate current flows induced in tissue phantoms. It has been found that the addition and subtraction of AE signals acquired by two circuits are independent components, regardless of whether the two sources are positioned at the same or different depths. In the ultrasound field, the AE signal from the bridge circuits is stronger, with a higher signal-to-noise ratio, than without a bridge circuit. Both experimental and simulated AE images depend on the magnitude and direction of the current, as well as the geometry (shape and thickness) and location of the current sources in the ultrasound field (2.25-MHz transducer). The experimental results are consistent with simulations consisting of multiple current sources. Real-time 3-D ultrasound current source density images of multiple current flows co-registered with convention pulse echo ultrasound potentially facilitate monitoring of neurologic disorders. PMID:27374926

  9. Electric Field Distribution Excited by Indoor Radio Source for Exposure Compliance Assessment

    NASA Astrophysics Data System (ADS)

    Higashiyama, Junji; Tarusawa, Yoshiaki

    Correction factors are presented for estimating the RF electromagnetic field strength in the compliance assessment of human exposure from an indoor RF radio source in the frequency range from 800MHz to 3.5GHz. The correction factors are derived from the increase in the spatial average electric field strength distribution, which is dependent on the building materials. The spatial average electric field strength is calculated using relative complex dielectric constants of building materials. The relative complex dielectric constant is obtained through measurement of the transmission and reflection losses for eleven kinds of building materials used in business office buildings and single family dwellings.

  10. Electron cyclotron resonant multicusp magnetic field microwave plasma source for electric propulsion

    SciTech Connect

    Dahimene, M.; Mahoney, L.; Asmussen, J.

    1987-05-01

    The development of electrodeless microwave ion and plasma sources has been a recent, very active research project at Michigan State University. The results are efficient, compact microwave discharge configurations that operate at low pressures (0.5 mtorr to 100 mtorr) and efficiently produce low energy ions and free radicals and broad ion beams for oxidation, deposition, and etching experiments. The microwave discharge technology developed for these applications may be useful for application in electric propulsion. This paper reviews this microwave applicator technology and indicates how it may be extended to higher power levels and applied to electric propulsion systems. 12 references.

  11. The integration of renewable energy sources into electric power transmission systems

    SciTech Connect

    Barnes, P.R.; Dykas, W.P.; Kirby, B.J.; Purucker, S.L.; Lawler, J.S.

    1995-07-01

    Renewable energy technologies such as photovoltaics, solar thermal power plants, and wind turbines are nonconventional, environmentally attractive sources of energy that can be considered for electric power generation. Many of the areas with abundant renewable energy resources (very sunny or windy areas) are far removed from major load centers. Although electrical power can be transmitted over long distances of many hundreds of miles through high-voltage transmission lines, power transmission systems often operate near their limits with little excess capacity for new generation sources. This study assesses the available capacity of transmission systems in designated abundant renewable energy resource regions and identifies the requirements for high-capacity plant integration in selected cases. In general, about 50 MW of power from renewable sources can be integrated into existing transmission systems to supply local loads without transmission upgrades beyond the construction of a substation to connect to the grid. Except in the Southwest, significant investment to strengthen transmission systems will be required to support the development of high-capacity renewable sources of 1000 MW or greater in areas remote from major load centers. Cost estimates for new transmission facilities to integrate and dispatch some of these high-capacity renewable sources ranged from several million dollars to approximately one billion dollars, with the latter figure an increase in total investment of 35%, assuming that the renewable source is the only user of the transmission facility.

  12. On error sources during airborne measurements of the ambient electric field

    NASA Technical Reports Server (NTRS)

    Evteev, B. F.

    1991-01-01

    The principal sources of errors during airborne measurements of the ambient electric field and charge are addressed. Results of their analysis are presented for critical survey. It is demonstrated that the volume electric charge has to be accounted for during such measurements, that charge being generated at the airframe and wing surface by droplets of clouds and precipitation colliding with the aircraft. The local effect of that space charge depends on the flight regime (air speed, altitude, particle size, and cloud elevation). Such a dependence is displayed in the relation between the collector conductivity of the aircraft discharging circuit - on one hand, and the sum of all the residual conductivities contributing to aircraft discharge - on the other. Arguments are given in favor of variability in the aircraft electric capacitance. Techniques are suggested for measuring from factors to describe the aircraft charge.

  13. Land-Use Intensity of Electricity Production: Comparison Across Multiple Sources

    NASA Astrophysics Data System (ADS)

    Swain, M.; Lovering, J.; Blomqvist, L.; Nordhaus, T.; Hernandez, R. R.

    2015-12-01

    Land is an increasingly scarce global resource that is subject to competing pressures from agriculture, human settlement, and energy development. As countries concerned about climate change seek to decarbonize their power sectors, renewable energy sources like wind and solar offer obvious advantages. However, the land needed for new energy infrastructure is also an important environmental consideration. The land requirement of different electricity sources varies considerably, but there are very few studies that offer a normalized comparison. In this paper, we use meta-analysis to calculate the land-use intensity (LUI) of the following electricity generation sources: wind, solar photovoltaic (PV), concentrated solar power (CSP), hydropower, geothermal, nuclear, biomass, natural gas, and coal. We used data from existing studies as well as original data gathered from public records and geospatial analysis. Our land-use metric includes land needed for the generation facility (e.g., power plant or wind farm) as well as the area needed to mine fuel for natural gas, coal, and nuclear power plants. Our results found the lowest total LUI for nuclear power (115 ha/TWh/y) and the highest LUI for biomass (114,817 ha/TWh/y). Solar PV and CSP had a considerably lower LUI than wind power, but both were an order of magnitude higher than fossil fuels (which ranged from 435 ha/TWh/y for natural gas to 579 ha/TWh/y for coal). Our results suggest that a large build-out of renewable electricity, though it would offer many environmental advantages over fossil fuel power sources, would require considerable land area. Among low-carbon energy sources, relatively compact sources like nuclear and solar have the potential to reduce land requirements.

  14. CSI-EPT: A Contrast Source Inversion Approach for Improved MRI-Based Electric Properties Tomography.

    PubMed

    Balidemaj, Edmond; van den Berg, Cornelis A T; Trinks, Johan; van Lier, Astrid L H M W; Nederveen, Aart J; Stalpers, Lukas J A; Crezee, Hans; Remis, Rob F

    2015-09-01

    Electric properties tomography (EPT) is an imaging modality to reconstruct the electric conductivity and permittivity inside the human body based on B1(+) maps acquired by a magnetic resonance imaging (MRI) system. Current implementations of EPT are based on the local Maxwell equations and assume piecewise constant media. The accuracy of the reconstructed maps may therefore be sensitive to noise and reconstruction errors occur near tissue boundaries. In this paper, we introduce a multiplicative regularized CSI-EPT method (contrast source inversion-electric properties tomography) where the electric tissue properties are retrieved in an iterative fashion based on a contrast source inversion approach. The method takes the integral representations for the electromagnetic field as a starting point and the tissue parameters are obtained by iteratively minimizing an objective function which measures the discrepancy between measured and modeled data and the discrepancy in satisfying a consistency equation known as the object equation. Furthermore, the objective function consists of a multiplicative Total Variation factor for noise suppression during the reconstruction process. Finally, the presented implementation is able to simultaneously include more than one B1(+) data set acquired by complementary RF excitation settings. We have performed in vivo simulations using a female pelvis model to compute the B1(+) fields. Three different RF excitation settings were used to acquire complementary B1(+) fields for an improved overall reconstruction. Numerical results illustrate the improved reconstruction near tissue boundaries and the ability of CSI-EPT to reconstruct small tissue structures. PMID:25706578

  15. Non-powered Dams: An untapped source of renewable electricity in the USA

    SciTech Connect

    Hadjerioua, Boualem; Kao, Shih-Chieh; Wei, Yaxing; Battey, Hoyt; Smith, Brennan T

    2012-01-01

    Hydropower has been a source of clean, renewable electricity in the USA for more than 100 years. Today, approximately 2500 US dams provide 78 GW of conventional and 22 GW of pumped-storage hydropower. In contrast, another approximately 80 000 dams in the USA do not include hydraulic turbine equipment and provide non-energy related services, such as flood control, water supply, navigation, and recreation.

  16. A new source of horizontal electric fields in the mid-latitude stratosphere

    NASA Technical Reports Server (NTRS)

    Holzworth, R. H.

    1989-01-01

    Superpressure balloon-borne instruments that measure the vector stratospheric electric field at latitudes near 45 + or - 10 deg S reveal several features in fair weather that cannot be attributed to ionospheric, thunderstorm, or other known sources. Over 180 days of electric field, conductivity, and current density data have been taken at the constant altitude of 26 km, using long-duration balloon flights in the Southern Hemisphere. Throughout these data the fair-weather horizontal electric field has a magnitude (10-50 mV/m) that cannot be due to mid-latitude ionospheric dynamo action. Furthermore, the fields are highly variable in amplitude, almost turbulent in appearance, while the vector direction steadily rotates in a counterclockwise manner. The period of this rotation is close to the quasi-inertial wave period for the latitude of the balloon. For these flights, the electric field rotation period varies between 14 and 21 hours. Some possible causes that might explain the electric field and current measurements reported herein are discussed.

  17. Cosmic-ray source of runaway electrons in thundercloud electric field.

    NASA Astrophysics Data System (ADS)

    Babich, L. P.; Bochkov, E. I.; Kutsyk, I. M.

    2008-12-01

    To increase an accuracy of numerical simulations of the high-altitude and high-energy electric phenomena in thunderstorm atmosphere basing on the electric breakdown combining the cosmic-ray effects and relativistic runaway electron (RE) avalanches it is necessary to have accurate source of seed REs produced by cosmic rays. We calculated the source using the Monte-Carlo technique. Actually a number of secondary electrons was calculated with energies above the runaway threshold depending on the field overvoltage relative to the minimum of the drag force affecting electrons. The cosmic radiation propagation through the atmosphere was simulated based on simplified model of the nuclear cascade: a cosmic proton was assumed to completely lose its energy in the first interaction with air nuclei, producing 15 pions with equal energies. The flux of primary radiation was divided into 20 angular groups containing equal number of particles. In view of the lack of the experimental data on the RE source it is impossible to directly estimate the accuracy of the obtained source. Therefore the model reliability was verified by comparing results of secondary radiation calculations with known experimental altitude variations in the secondary cosmic rays and their spectra. The source was calculated as the specific generation rate of the secondary electrons by cosmic radiation dependent on electric field overvoltage and the altitude above the Earth's surface. It is recommended as a source of relativistic runaway electron avalanches in numerical simulations of electric discharges in atmosphere controlled by REs in thunderstorm fields and their emissions: optical, gamma and neutrons. The source already was used to simulate the high-altitude discharge and its emissions. In particular, the calculated gamma-ray pulses (photon numbers and spectra, pulse duration) agree with detected terrestrial gamma-ray flashes (TGFs). Conclusions of the published analyses (Cummer and Lyons, 2005; Cummer et

  18. Solid and hollow pedicle screws affect the electrical resistance: A potential source of error with stimulus-evoked electromyography

    PubMed Central

    Wang, Hongwei; Liao, Xinhua; Ma, Xianguang; Li, Changqing; Han, Jianda; Zhou, Yue

    2013-01-01

    Background: Although stimulus evoked electromyography (EMG) is commonly used to confirm the accuracy of pedicle screw placement. There are no studies to differentiate between solid screws and hollow screws to the electrical resistance of pedicle screws. We speculate that the electrical resistance of the solid and hollow pedicle screws may be different and then a potential source of error with stimulus-evoked EMG may happen. Materials and Methods: Resistance measurements were obtained from 12 pedicle screw varieties (6 screws of each manufacturer) across the screw shank based on known constant current and measured voltage. The voltage was measured 5 times at each site. Results: Resistance of all solid screws ranged from 0.084 Ω to 0.151 Ω (mean =0.118 ± 0.024 Ω) and hollow screws ranged from 0.148 Ω to 0.402 Ω (mean = 0.285 ± 0.081 Ω). There was a significant difference of resistance between the solid screws and hollow screws (P < 0.05). The screw with the largest diameter no matter solid screws or hollow screws had lower resistance than screws with other diameters. No matter in solid screws group or hollow screws group, there were significant differences (P < 0.05) between the 5.0 mm screws and 6.0 mm screws, 6.0 mm screws and 7.0 mm screws, 5.0 mm screws and 7.0 mm screws, 4.5 mm screws and 5.5 mm screws, 5.5 mm screws and 6.5 mm screws, 4.5 mm screws and 6.5 mm screws. The resistance of hollow screws was much larger than the solid screws in the same diameter group (P < 0.05). Conclusions: Hollow pedicle screws have the potential for high electrical resistance compared to the solid pedicle screws and therefore may affect the EMG response during stimulus-evoked EMG testing in pedicle screw fixation especially in minimally invasive percutaneous pedical screw fixation surgery. PMID:23960278

  19. Thermochemical Beam Source of ThO for Measuring the Electric Dipole Moment of the Electron

    NASA Astrophysics Data System (ADS)

    Petrik, Elizabeth; Baron, Jacob; Hutzler, Nick; Lasner, Zack; O'Leary, Brendon; Panda, Cristian; West, Adam; Wilburn, Grey; Demille, David; Gabrielse, Gerald; Doyle, John

    2016-05-01

    The observation of an electron electric dipole moment (eEDM) would reveal new sources of time-reversal symmetry violation, potentially shedding light on the excess of matter over antimatter in the universe. Certain heavy polar molecules have a large interaction between the nuclear electric field and the eEDM that can be interrogated in the lab, making them ideal for eEDM searches. This molecular feature allowed our measurement with thorium monoxide (ThO) to set the most stringent upper limit on the eEDM to date. Producing enough such molecules in the gas phase to perform a precision measurement is challenging because of their reactivity and low vapor pressure. Thus, a cryo buffer gas beam source yielding a high flux (1013/s) of cold (4 K), slow (170 m/s) ThO via laser ablation of ThO2 was critical to our success. We now report on progress towards an improved beam source, which relies on favorable thorium-oxygen chemistry to produce gas-phase ThO via laser heating of a mixture of ThO2 and Th. This new source has an average beam flux > 5 times larger than in and will contribute to a future eEDM measurement with greatly improved statistics. Funded by the NSF.

  20. The source altitude, electric current, and intrinsic brightness of terrestrial gamma ray flashes

    NASA Astrophysics Data System (ADS)

    Cummer, Steven A.; Briggs, Michael S.; Dwyer, Joseph R.; Xiong, Shaolin; Connaughton, Valerie; Fishman, Gerald J.; Lu, Gaopeng; Lyu, Fanchao; Solanki, Rahulkumar

    2014-12-01

    Many details of how thunderstorms generate terrestrial gamma ray flashes (TGFs) and other forms of high-energy radiation remain uncertain, including the basic question of where they are produced. We exploit the association of distinct low-frequency radio emissions with generation of terrestrial gamma ray flashes (TGFs) to directly measure for the first time the TGF source altitude. Analysis of two events reveals source altitudes of 11.8 ± 0.4 km and 11.9 ± 0.9 km. This places the source region in the interior of the thunderstorm between the two main charge layers and implies an intrinsic TGF brightness of approximately 1018 runaway electrons. The electric current in this nontraditional lightning process is found to be strong enough to drive nonlinear effects in the ionosphere, and in one case is comparable to the highest peak current lightning processes on the planet.

  1. Ultrabright single-photon source on diamond with electrical pumping at room and high temperatures

    NASA Astrophysics Data System (ADS)

    Fedyanin, D. Yu; Agio, M.

    2016-07-01

    The recently demonstrated electroluminescence of color centers in diamond makes them one of the best candidates for room temperature single-photon sources. However, the reported emission rates are far off what can be achieved by state-of-the-art electrically driven epitaxial quantum dots. Since the electroluminescence mechanism has not yet been elucidated, it is not clear to what extent the emission rate can be increased. Here we develop a theoretical framework to study single-photon emission from color centers in diamond under electrical pumping. The proposed model comprises electron and hole trapping and releasing, transitions between the ground and excited states of the color center as well as structural transformations of the center due to carrier trapping. It provides the possibility to predict both the photon emission rate and the wavelength of emitted photons. Self-consistent numerical simulations of the single-photon emitting diode based on the proposed model show that the photon emission rate can be as high as 100 kcounts s‑1 at standard conditions. In contrast to most optoelectronic devices, the emission rate steadily increases with the device temperature achieving of more than 100 Mcount s‑1 at 500 K, which is highly advantageous for practical applications. These results demonstrate the potential of color centers in diamond as electrically driven non-classical light emitters and provide a foundation for the design and development of single-photon sources for optical quantum computation and quantum communication networks operating at room and higher temperatures.

  2. Strategies for the integration of intermittent renewable energy sources in the electrical system

    NASA Astrophysics Data System (ADS)

    Romanelli, Francesco

    2016-03-01

    Europe is pursuing an aggressive programme to increase its share of renewable energy source (RES). However, the integration of intermittent RES (wind and photovoltaic) in the electrical system requires either maintaining in operation thermal backup systems or providing a substantial amount of electricity storage. We analyze the Italian electricity data for the year 2013 provided by the transmission system operator TERNA. The present level of intermittent RES power is scaled-up to a level at which it generates an amount of electricity equal to the annual demand. While a substantial reduction of the energy annually produced by fossil backup systems (and the associated CO2 emission) with respect to the no-RES case is possible in many scenarios considered here, the backup power is generally only marginally reduced below the value in the absence of RES. The strategy proposed is based on the combination of a modest amount of storage (0.5-5TWh) and base-load power (6-15GW, to be used during the seasons of low RES production). In this way the non-RES installed power can be reduced from ˜ 50 GW to less than 15GW and could be covered by a combination of biomass and nuclear energy without any CO2 emission.

  3. Source book for planning nuclear dual-purpose electric/distillation desalination plants

    SciTech Connect

    Reed, S.A.

    1981-02-01

    A source book on nuclear dual-purpose electric/distillation desalination plants was prepared to assist government and other planners in preparing broad evaluations of proposed applications of dual-purpose plants. The document is divided into five major sections. Section 1 presents general discussions relating to the benefits of dual-purpose plants, and spectrum for water-to-power ratios. Section 2 presents information on commercial nuclear plants manufactured by US manufacturers. Section 3 gives information on distillation desalting processes and equipment. Section 4 presents a discussion on feedwater pretreatment and scale control. Section 5 deals with methods for coupling the distillation and electrical generating plants to operate in the dual mode.

  4. Real-time analysis of mechanical and electrical resonances with open-source sound card software

    NASA Astrophysics Data System (ADS)

    Makan, G.; Kopasz, K.; Gingl, Z.

    2014-01-01

    We present an easily reproducible, open-source, sound card based experimental set-up to support transfer function measurement. Our system is able to visualize the signals of mechanical and electrical resonances and their spectra in real time. We give a brief description of the system, and show some examples of electrical and mechanical resonance experiments that are supported by the system. The theoretical background, experimental set-up, component selection and digital signal processing are all discussed, and more detailed information (building instructions, software download) is provided on a dedicated web page (www.noise.inf.u-szeged.hu/edudev/RealTimeAnalysisOfResonances/). The experimental set-up can support the undergraduate and graduate education of students of physics, physics education and engineering by means of experimental demonstrations and laboratory exercises. The very low cost, high efficiency and transparent system provides a scalable experimental environment that can be easily built in several instances.

  5. The integration of renewable energy sources into electric power distribution systems. Volume 2, Utility case assessments

    SciTech Connect

    Zaininger, H.W.; Ellis, P.R.; Schaefer, J.C.

    1994-06-01

    Electric utility distribution system impacts associated with the integration of renewable energy sources such as photovoltaics (PV) and wind turbines (WT) are considered in this project. The impacts are expected to vary from site to site according to the following characteristics: (1) The local solar insolation and/or wind characteristics; (2) renewable energy source penetration level; (3) whether battery or other energy storage systems are applied; and (4) local utility distribution design standards and planning practices. Small, distributed renewable energy sources are connected to the utility distribution system like other, similar kW- and MW-scale equipment and loads. Residential applications are expected to be connected to single-phase 120/240-V secondaries. Larger kw-scale applications may be connected to three-phase secondaries, and larger hundred-kW and MW-scale applications, such as MW-scale windfarms or PV plants, may be connected to electric utility primary systems via customer-owned primary and secondary collection systems. Small, distributed renewable energy sources installed on utility distribution systems will also produce nonsite-specific utility generation system benefits such as energy and capacity displacement benefits, in addition to the local site-specific distribution system benefits. Although generation system benefits are not site-specific, they are utility-specific, and they vary significantly among utilities in different regions. In addition, transmission system benefits, environmental benefits and other benefits may apply. These benefits also vary significantly among utilities and regions. Seven utility case studies considering PV, WT, and battery storage were conducted to identify a range of potential renewable energy source distribution system applications.

  6. 46 CFR 32.60-45 - Segregation of spaces containing the emergency source of electric power-TB/ALL.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... electric power-TB/ALL. 32.60-45 Section 32.60-45 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY TANK... power—TB/ALL. (a) The provisions of this section shall apply to all vessels contracted for on or after October 1, 1958. (b) When a compartment containing the emergency source of electric power, or...

  7. 46 CFR 32.60-45 - Segregation of spaces containing the emergency source of electric power-TB/ALL.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... electric power-TB/ALL. 32.60-45 Section 32.60-45 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY TANK... power—TB/ALL. (a) The provisions of this section shall apply to all vessels contracted for on or after October 1, 1958. (b) When a compartment containing the emergency source of electric power, or...

  8. 46 CFR 32.60-45 - Segregation of spaces containing the emergency source of electric power-TB/ALL.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... electric power-TB/ALL. 32.60-45 Section 32.60-45 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY TANK... power—TB/ALL. (a) The provisions of this section shall apply to all vessels contracted for on or after October 1, 1958. (b) When a compartment containing the emergency source of electric power, or...

  9. 46 CFR 32.60-45 - Segregation of spaces containing the emergency source of electric power-TB/ALL.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... electric power-TB/ALL. 32.60-45 Section 32.60-45 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY TANK... power—TB/ALL. (a) The provisions of this section shall apply to all vessels contracted for on or after October 1, 1958. (b) When a compartment containing the emergency source of electric power, or...

  10. Electroluminescence from localized defects in zinc oxide: toward electrically driven single photon sources at room temperature.

    PubMed

    Choi, Sumin; Berhane, Amanuel M; Gentle, Angus; Ton-That, Cuong; Phillips, Matthew R; Aharonovich, Igor

    2015-03-18

    Single photon sources are required for a wide range of applications in quantum information science, quantum cryptography, and quantum communications. However, the majority of room temperature emitters to date are only excited optically, which limits their proper integration into scalable devices. In this work, we overcome this limitation and present room temperature electrically driven light emission from localized defects in zinc oxide (ZnO) nanoparticles and thin films. The devices emit in the red spectral range and show excellent rectifying behavior. The emission is stable over an extensive period of time, providing an important prerequisite for practical devices. Our results open possibilities for building new ZnO-based quantum integrated devices that incorporate solid-state single photon sources for quantum information technologies. PMID:25741632

  11. The Problem of Electric Sources in Einstein's Hermite-symmetric Field Theory

    NASA Astrophysics Data System (ADS)

    Kreisel, Eckhard

    It is considered, if a geometric source breaks the A-invariance and Hermite-symmetry of Einstein's Hermitian relativity. It would be very meaningful to interpret a source of this kind as electric current. With this extension Einstein's unitary field theory contains electromagnetism and the gluonic vacuum of chromodynamics.Translated AbstractDas Problem elektrischer Quellen in Einsteins Hermitesymmetrischer FeldtheorieEs wird untersucht, ob man Quellen so einführen kann, daß die A-Invarianz und die Hermitesymmetrie der Einsteinschen unitären Feldtheorie nicht verletzt werden. Die Quellen sind als elektrische Ströme zu interpretieren. Mit dieser Erweiterung umfaßt die unitäre Feldtheorie Einsteins Gravitation, Elektromagnetismus und das Gluonvakuum der Chromodynamik.

  12. Head model and electrical source imaging: A study of 38 epileptic patients☆

    PubMed Central

    Birot, Gwénael; Spinelli, Laurent; Vulliémoz, Serge; Mégevand, Pierre; Brunet, Denis; Seeck, Margitta; Michel, Christoph M.

    2014-01-01

    Electrical source imaging (ESI) aims at reconstructing the electrical brain activity from scalp EEG. When applied to interictal epileptiform discharges (IEDs), this technique is of great use for identifying the irritative zone in focal epilepsies. Inaccuracies in the modeling of electro-magnetic field propagation in the head (forward model) may strongly influence ESI and lead to mislocalization of IED generators. However, a systematic study on the influence of the selected head model on the localization precision of IED in a large number of patients with known focus localization has not yet been performed. We here present such a performance evaluation of different head models in a dataset of 38 epileptic patients who have undergone high-density scalp EEG, intracranial EEG and, for the majority, subsequent surgery. We compared ESI accuracy resulting from three head models: a Locally Spherical Model with Anatomical Constraints (LSMAC), a Boundary Element Model (BEM) and a Finite Element Model (FEM). All of them were computed from the individual MRI of the patient and ESI was performed on averaged IED. We found that all head models provided very similar source locations. In patients having a positive post-operative outcome, at least 74% of the source maxima were within the resection. The median distance from the source maximum to the nearest intracranial electrode showing IED was 13.2, 15.6 and 15.6 mm for LSMAC, BEM and FEM, respectively. The study demonstrates that in clinical applications, the use of highly sophisticated and difficult to implement head models is not a crucial factor for an accurate ESI. PMID:25003030

  13. The Integration of Renewable Energy Sources into Electric Power Distribution Systems, Vol. II Utility Case Assessments

    SciTech Connect

    Zaininger, H.W.

    1994-01-01

    Electric utility distribution system impacts associated with the integration of renewable energy sources such as photovoltaics (PV) and wind turbines (WT) are considered in this project. The impacts are expected to vary from site to site according to the following characteristics: the local solar insolation and/or wind characteristics, renewable energy source penetration level, whether battery or other energy storage systems are applied, and local utility distribution design standards and planning practices. Small, distributed renewable energy sources are connected to the utility distribution system like other, similar kW- and MW-scale equipment and loads. Residential applications are expected to be connected to single-phase 120/240-V secondaries. Larger kW-scale applications may be connected to three+phase secondaries, and larger hundred-kW and y-scale applications, such as MW-scale windfarms, or PV plants, may be connected to electric utility primary systems via customer-owned primary and secondary collection systems. In any case, the installation of small, distributed renewable energy sources is expected to have a significant impact on local utility distribution primary and secondary system economics. Small, distributed renewable energy sources installed on utility distribution systems will also produce nonsite-specific utility generation system benefits such as energy and capacity displacement benefits, in addition to the local site-specific distribution system benefits. Although generation system benefits are not site-specific, they are utility-specific, and they vary significantly among utilities in different regions. In addition, transmission system benefits, environmental benefits and other benefits may apply. These benefits also vary significantly among utilities and regions. Seven utility case studies considering PV, WT, and battery storage were conducted to identify a range of potential renewable energy source distribution system applications. The

  14. Inhomogeneities of plasma density and electric field as sources of electrostatic turbulence in the auroral region

    SciTech Connect

    Ilyasov, Askar A.; Chernyshov, Alexander A. Mogilevsky, Mikhail M.; Golovchanskaya, Irina V. Kozelov, Boris V.

    2015-03-15

    Inhomogeneities of plasma density and non-uniform electric fields are compared as possible sources of a sort of electrostatic ion cyclotron waves that can be identified with broadband extremely low frequency electrostatic turbulence in the topside auroral ionosphere. Such waves are excited by inhomogeneous energy-density-driven instability. To gain a deeper insight in generation of these waves, computational modeling is performed with various plasma parameters. It is demonstrated that inhomogeneities of plasma density can give rise to this instability even in the absence of electric fields. By using both satellite-observed and model spatial distributions of plasma density and electric field in our modeling, we show that specific details of the spatial distributions are of minor importance for the wave generation. The solutions of the nonlocal inhomogeneous energy-density-driven dispersion relation are investigated for various ion-to-electron temperature ratios and directions of wave propagation. The relevance of the solutions to the observed spectra of broadband extremely low frequency emissions is shown.

  15. An electrically driven cavity-enhanced source of indistinguishable photons with 61% overall efficiency

    NASA Astrophysics Data System (ADS)

    Schlehahn, A.; Thoma, A.; Munnelly, P.; Kamp, M.; Höfling, S.; Heindel, T.; Schneider, C.; Reitzenstein, S.

    2016-04-01

    We report on an electrically driven efficient source of indistinguishable photons operated at pulse-repetition rates f up to 1.2 GHz. The quantum light source is based on a p-i-n-doped micropillar cavity with integrated self-organized quantum dots, which exploits cavity quantum electrodynamics effects in the weak coupling regime to enhance the emission of a single quantum emitter coupled to the cavity mode. We achieve an overall single-photon extraction efficiency of (61 ± 11) % for a device triggered electrically at f = 625 MHz. Analyzing the suppression of multi-photon emission events as a function of excitation repetition rate, we observe single-photon emission associated with g(2)HBT(0) values between 0.076 and 0.227 for f ranging from 373 MHz to 1.2 GHz. Hong-Ou-Mandel-type two-photon interference experiments under pulsed current injection at 487 MHz reveal a photon-indistinguishability of (41.1 ± 9.5) % at a single-photon emission rate of (92 ± 23) MHz.

  16. Influence of magnetic field on the electric breakdown in penning ion source.

    PubMed

    Mahjour-Shafiei, M; Noori, H; Ranjbar, A H

    2011-11-01

    A cold-cathode penning-type ion source has been developed in our laboratory to study the electric breakdown in this type of sources. The breakdown voltage was measured as a function of axial magnetic field, in the range of 440-600 G, and anode length, in steps of 14, 20, and 24 mm. The measurement was performed with stainless steel cathodes in argon gas at pressure of 4 × 10(-2) mbar. Furthermore, a model was developed to explain the breakdown voltage data. In the construction of the model, the first Townsend coefficient was not directly used to avoid difficulties originating from the non-uniformity of the electric field. The empirical parameters of the model were obtained using the experimental data. The equation γ = c × (E(z)/N)(n), expressing the effective secondary emission coefficient in terms of reduced electric field, which was needed in the modeling process, was inspired from previous works. The parameters c and n were then calculated from the empirical parameters of the model. The n parameter turned out to be 0.59, which differs from the value reported by other authors merely by 1.6%. Three values, 0.010, 0.013, and 0.017 corresponding to the three anodes were obtained for the c parameter. These numbers are in good agreement with 0.01, which has been reported in the previous works. It was also found that the value of n has a decisive impact on the breakdown voltage curve in the high breakdown voltage region. PMID:22128971

  17. Influence of magnetic field on the electric breakdown in penning ion source

    NASA Astrophysics Data System (ADS)

    Mahjour-Shafiei, M.; Noori, H.; Ranjbar, A. H.

    2011-11-01

    A cold-cathode penning-type ion source has been developed in our laboratory to study the electric breakdown in this type of sources. The breakdown voltage was measured as a function of axial magnetic field, in the range of 440-600 G, and anode length, in steps of 14, 20, and 24 mm. The measurement was performed with stainless steel cathodes in argon gas at pressure of 4 × 10-2 mbar. Furthermore, a model was developed to explain the breakdown voltage data. In the construction of the model, the first Townsend coefficient was not directly used to avoid difficulties originating from the non-uniformity of the electric field. The empirical parameters of the model were obtained using the experimental data. The equation γ = c × (Ez/N)n, expressing the effective secondary emission coefficient in terms of reduced electric field, which was needed in the modeling process, was inspired from previous works. The parameters c and n were then calculated from the empirical parameters of the model. The n parameter turned out to be 0.59, which differs from the value reported by other authors merely by 1.6%. Three values, 0.010, 0.013, and 0.017 corresponding to the three anodes were obtained for the c parameter. These numbers are in good agreement with 0.01, which has been reported in the previous works. It was also found that the value of n has a decisive impact on the breakdown voltage curve in the high breakdown voltage region.

  18. Short and long term energy source technologies for electrically-heated catalysts

    SciTech Connect

    Bass, E.A.; Johnston, R.; Hunt, B.; Rodriguez, G.; Gottberg, I.; Ishizuka, A.; Hall, W.

    1996-12-31

    A consortium of six companies formed by Southwest Research Institute conducted an investigation into alternative electric power supplies for electrically heated catalysts (EHCs). Previous studies showed that, due to their high power and energy requirements upon engine start, battery-powered EHCs would cause premature failure of common lead-acid batteries. This project identified and characterized several alternative electric energy sources. Production starting, lighting, and ignition (SLI) batteries were evaluated along with lead-acid electric vehicle batteries, nickel-cadmium aircraft batteries, prototype ultracapacitors, and a modified alternator. Battery Council International and US Advanced Battery Consortium test methods were employed where applicable. Evaluations included ambient and low-temperature ({minus}18 C) constant-current discharge characterization, low-temperature peak-power determination, self-discharge, and passenger car Federal Test Procedure (FTP) emissions and fuel economy. As demonstrated by discharge-energy and peak-power tests, some EV batteries may have potential for the EHC/SLI application. Other appeared to be poorly suited due to low-temperature problems. The best low-temperature performance was observed with ultracapacitors. These units were also the least to be affected by the power versus energy trade-off. The problems with these prototype storage units were high cost and self-discharge rate. Alternator power for EHCs as an alternative to energy storage devices was successfully demonstrated on a vehicle. Power produced was a linear function of engine speed and EHC load. High-voltage switching devices will be necessary for successful use of alternator power on EHCs. A fuel economy penalty was expected, but not observed during the FTP vehicle demonstration.

  19. Experimental verification of isotropic radiation from a coherent dipole source via electric-field-driven LC resonator metamaterials.

    PubMed

    Tichit, Paul-Henri; Burokur, Shah Nawaz; Qiu, Cheng-Wei; de Lustrac, André

    2013-09-27

    It has long been conjectured that isotropic radiation by a simple coherent source is impossible due to changes in polarization. Though hypothetical, the isotropic source is usually taken as the reference for determining a radiator's gain and directivity. Here, we demonstrate both theoretically and experimentally that an isotropic radiator can be made of a simple and finite source surrounded by electric-field-driven LC resonator metamaterials designed by space manipulation. As a proof-of-concept demonstration, we show the first isotropic source with omnidirectional radiation from a dipole source (applicable to all distributed sources), which can open up several possibilities in axion electrodynamics, optical illusion, novel transformation-optic devices, wireless communication, and antenna engineering. Owing to the electric- field-driven LC resonator realization scheme, this principle can be readily applied to higher frequency regimes where magnetism is usually not present. PMID:24116780

  20. Causal Analysis of the Inadvertent Contact with an Uncontrolled Electrical Hazardous Energy Source (120 Volts AC)

    SciTech Connect

    David E. James; Dennis E. Raunig; Sean S. Cunningham

    2014-10-01

    On September 25, 2013, a Health Physics Technician (HPT) was performing preparations to support a pneumatic transfer from the HFEF Decon Cell to the Room 130 Glovebox in HFEF, per HFEF OI 3165 section 3.5, Field Preparations. This activity involves an HPT setting up and climbing a portable ladder to remove the 14-C meter probe from above ball valve HBV-7. The HPT source checks the meter and probe and then replaces the probe above HBV-7, which is located above Hood ID# 130 HP. At approximately 13:20, while reaching past the HBV-7 valve position indicator switches in an attempt to place the 14-C meter probe in the desired location, the HPT’s left forearm came in contact with one of the three sets of exposed terminals on the valve position indication switches for HBV 7. This resulted in the HPT receiving an electrical shock from a 120 Volt AC source. Upon moving the arm, following the electrical shock, the HPT noticed two exposed electrical connections on a switch. The HPT then notified the HFEF HPT Supervisor, who in turn notified the MFC Radiological Controls Manager and HFEF Operations Manager of the situation. Work was stopped in the area and the hazard was roped off and posted to prevent access to the hazard. The HPT was escorted by the HPT Supervisor to the MFC Dispensary and then preceded to CFA medical for further evaluation. The individual was evaluated and released without any medical restrictions. Causal Factor (Root Cause) A3B3C01/A5B2C08: - Knowledge based error/Attention was given to wrong issues - Written Communication content LTA, Incomplete/situation not covered The Causal Factor (root cause) was attention being given to the wrong issues during the creation, reviews, verifications, and actual performance of HFEF OI-3165, which covers the need to perform the weekly source check and ensure placement of the probe prior to performing a “rabbit” transfer. This resulted in the hazard not being identified and mitigated in the procedure. Work activities

  1. Electrically switchable organo-inorganic hybrid for a white-light laser source.

    PubMed

    Huang, Jui-Chieh; Hsiao, Yu-Cheng; Lin, Yu-Ting; Lee, Chia-Rong; Lee, Wei

    2016-01-01

    We demonstrate a spectrally discrete white-light laser device based on a photonic bandgap hybrid, which is composed of a soft photonic crystal; i.e., a layer of dye-doped cholesteric liquid crystal (CLC), sandwiched between two imperfect but identical, inorganic multilayer photonic crystals. With a sole optical pump, a mono-, bi-, or tri-chromatic laser can be obtained and, through the soft photonic crystal regulated by an applied voltage, the hybrid possesses electrical tunability in laser wavelength. The three emitted spectral peaks originate from two bandedges of the CLC reflection band as well as one of the photonic defect modes in dual-mode lasing. Thanks to the optically bistable nature of CLC, such a white-light laser device can operate in quite an energy-saving fashion. This technique has potential to fulfill the present mainstream in the coherent white-light source. PMID:27324219

  2. Focusing Sources on Induced Polarization and Electrical Resistivity Method Applied to Soil Pollution Problems

    NASA Astrophysics Data System (ADS)

    Tejero, A.; Lopez, A.; Induced Polarization Team

    2013-05-01

    In recent years the problems of soil contamination have been increasing and geophysical methods, particularly electrical resistivity tomography (ERT) have struggled to find and monitor cases of contamination. Moreover, Induced Polarization (IP) has shown promise in mapping contaminant plumes, although both techniques (ERT and IP) have problems like noise, inductive coupling, effects of electrodes, etc. limiting the precision and accuracy of the data. To overcome these problems, this paper introduces a novel technique of focusing sources. This technique reduces the effects of adjacent vertical formations and contacts due to the flowing of current in a vertical way at the zone where the electrode potentials have been deployed. This fact allows obtaining cleaner data of ERT and IP. In order to introduce the proposed technique a vertical contact synthetic model is studied and after to a cultivar area in Hidalgo State, México which presents different types of

  3. Electrically switchable organo–inorganic hybrid for a white-light laser source

    NASA Astrophysics Data System (ADS)

    Huang, Jui-Chieh; Hsiao, Yu-Cheng; Lin, Yu-Ting; Lee, Chia-Rong; Lee, Wei

    2016-06-01

    We demonstrate a spectrally discrete white-light laser device based on a photonic bandgap hybrid, which is composed of a soft photonic crystal; i.e., a layer of dye-doped cholesteric liquid crystal (CLC), sandwiched between two imperfect but identical, inorganic multilayer photonic crystals. With a sole optical pump, a mono-, bi-, or tri-chromatic laser can be obtained and, through the soft photonic crystal regulated by an applied voltage, the hybrid possesses electrical tunability in laser wavelength. The three emitted spectral peaks originate from two bandedges of the CLC reflection band as well as one of the photonic defect modes in dual-mode lasing. Thanks to the optically bistable nature of CLC, such a white-light laser device can operate in quite an energy-saving fashion. This technique has potential to fulfill the present mainstream in the coherent white-light source.

  4. Grounded electrical-source airborne transient electromagnetics (GREATEM) survey of Aso Volcano, Japan

    NASA Astrophysics Data System (ADS)

    Ito, Hisatoshi; Kaieda, Hideshi; Mogi, Toru; Jomori, Akira; Yuuki, Youichi

    2014-05-01

    Grounded electrical-source airborne transient electromagnetics (GREATEM), a type of semi-airborne electromagnetics, was used to examine Aso Volcano in south-west Japan, to verify its applicability to surveying deep subsurface resistivity structures. Comparison of the GREATEM resistivity values with those of ground-based transient electromagnetics (TEM) data, repeated GREATEM survey results at the same and different flight heights, and lithologic descriptions indicated that GREATEM can successfully identify underground structures as deep as ~800 m in rugged mountainous areas. An active volcanic region (Naka-Dake crater) was mapped as a low-resistivity zone from the surface to a depth of 100 m. This low-resistivity zone extended to the west-north-west, implying future volcanic activity in this area. Therefore, the GREATEM method is useful for surveying deep structures in large, inaccessible areas, such as volcanic provinces, in a quick, cost-effective way.

  5. Electrically switchable organo–inorganic hybrid for a white-light laser source

    PubMed Central

    Huang, Jui-Chieh; Hsiao, Yu-Cheng; Lin, Yu-Ting; Lee, Chia-Rong; Lee, Wei

    2016-01-01

    We demonstrate a spectrally discrete white-light laser device based on a photonic bandgap hybrid, which is composed of a soft photonic crystal; i.e., a layer of dye-doped cholesteric liquid crystal (CLC), sandwiched between two imperfect but identical, inorganic multilayer photonic crystals. With a sole optical pump, a mono-, bi-, or tri-chromatic laser can be obtained and, through the soft photonic crystal regulated by an applied voltage, the hybrid possesses electrical tunability in laser wavelength. The three emitted spectral peaks originate from two bandedges of the CLC reflection band as well as one of the photonic defect modes in dual-mode lasing. Thanks to the optically bistable nature of CLC, such a white-light laser device can operate in quite an energy-saving fashion. This technique has potential to fulfill the present mainstream in the coherent white-light source. PMID:27324219

  6. Kuiper Belt Object Orbiter Using Advanced Radioisotope Power Sources and Electric Propulsion

    NASA Technical Reports Server (NTRS)

    Oleson, Steven R.; McGuire, Melissa L.; Dankanich, John; Colozza, Anthony; Schmitz, Paul; Khan, Omair; Drexler, Jon; Fittje, James

    2011-01-01

    A joint NASA GRC/JPL design study was performed for the NASA Radioisotope Power Systems Office to explore the use of radioisotope electric propulsion for flagship class missions. The Kuiper Belt Object Orbiter is a flagship class mission concept projected for launch in the 2030 timeframe. Due to the large size of a flagship class science mission larger radioisotope power system building blocks were conceptualized to provide the roughly 4 kW of power needed by the NEXT ion propulsion system and the spacecraft. Using REP the spacecraft is able to rendezvous with and orbit a Kuiper Belt object in 16 years using either eleven (no spare) 420 W advanced RTGs or nine (with a spare) 550 W advanced Stirling Radioisotope systems. The design study evaluated integrating either system and estimated impacts on cost as well as required General Purpose Heat Source requirements.

  7. The impacts of renewable energy policies on renewable energy sources for electricity generating capacity

    NASA Astrophysics Data System (ADS)

    Koo, Bryan Bonsuk

    Electricity generation from non-hydro renewable sources has increased rapidly in the last decade. For example, Renewable Energy Sources for Electricity (RES-E) generating capacity in the U.S. almost doubled for the last three year from 2009 to 2012. Multiple papers point out that RES-E policies implemented by state governments play a crucial role in increasing RES-E generation or capacity. This study examines the effects of state RES-E policies on state RES-E generating capacity, using a fixed effects model. The research employs panel data from the 50 states and the District of Columbia, for the period 1990 to 2011, and uses a two-stage approach to control endogeneity embedded in the policies adopted by state governments, and a Prais-Winsten estimator to fix any autocorrelation in the panel data. The analysis finds that Renewable Portfolio Standards (RPS) and Net-metering are significantly and positively associated with RES-E generating capacity, but neither Public Benefit Funds nor the Mandatory Green Power Option has a statistically significant relation to RES-E generating capacity. Results of the two-stage model are quite different from models which do not employ predicted policy variables. Analysis using non-predicted variables finds that RPS and Net-metering policy are statistically insignificant and negatively associated with RES-E generating capacity. On the other hand, Green Energy Purchasing policy is insignificant in the two-stage model, but significant in the model without predicted values.

  8. OAK RIDGE NATIONAL LABORATORY SPALLATION NEUTRON SOURCE ELECTRICAL SYSTEMS AVAILABILITY AND IMPROVEMENTS

    SciTech Connect

    Cutler, Roy I; Peplov, Vladimir V; Wezensky, Mark W; Norris, Kevin Paul; Barnett, William E; Hicks, Jim; Weaver, Joey T; Moss, John; Rust, Kenneth R; Mize, Jeffery J; Anderson, David E

    2011-01-01

    SNS electrical systems have been operational for 4 years. System availability statistics and improvements are presented for AC electrical systems, DC and pulsed power supplies and klystron modulators.

  9. Germany gets largest ever MRI scanner

    NASA Astrophysics Data System (ADS)

    Stafford, Ned

    2008-07-01

    A 57-tonne cylindrical magnet has arrived at the Jülich Research Centre in Germany, where physicists are putting together the world's largest magnetic resonance imaging (MRI) system. When the machine comes online next year, medical researchers will use it to examine the brain in unprecedented detail, in the hope of gaining new insights into neurodegenerative diseases such as Alzheimer's.

  10. Air pollution ranks as largest health risk

    NASA Astrophysics Data System (ADS)

    Wendel, JoAnna

    2014-04-01

    The World Health Organization (WHO) reports that 7 million people died in 2012 from air-pollution-related sicknesses, marking air pollution as the single largest environmental health risk. This finding, a result of better knowledge and assessment of the diseases, is more than double previous estimates of the risk of death from air pollution.

  11. Preliminary Analysis: Am-241 RHU/TEG Electric Power Source for Nanosatellites

    NASA Technical Reports Server (NTRS)

    Robertson, Glen A.; Young, David; Cunningham, Karen; Kim, Tony; Ambrosi, Richard M.; Williams, Hugo R.

    2014-01-01

    The Februay 2013 Space Works Commercial report indicates a strong increase in nano/microsatellite (1-50 kg) launch demand globally in future years. Nanosatellites (NanoSats) are small spacecraft in the 1-10 kg range, which present a simple, low-cost option for developing quickly-deployable satellites. CubeSats, a special category of NanoSats, are even being considered for interplanetary missions. However, the small dimensions of CubeSats and the limited mass of the NanoSat class in general place limits of capability on their electrical power systems (especially where typical power sources such as solar panels are considered) and stored energy reserves; restricting the power budget and overall functionality. For example, leveraging NanoSat clusters for computationally intensive problems that are solved collectively becomes more challenging with power related restrictions on communication and data-processing. Further, interplanetary missions that would take NanoSats far from the sun, make the use of solar panels less effective as a power source as their required area would become quite large. To overcome these limitations, americium 241 (Am-241) has been suggested as a low power source option. The Idaho National Laboratory, Center for Space Nuclear Research reports that: ? (Production) requires small quantities of isotope - 62.5 g of Pu-238; 250 g Am- 241 (for 5 We); Am-241 is available at around 1 kg/yr commercially; Am-241 produces 59 kev gammas which are stopped readily by tungsten so the radiation field is very low. Whereby, an Am-241 source could be placed in among the instruments and the waste heat used to heat the platform; and ? amounts of isotope are so low that launch approval may be easier, especially with tungsten encapsulation. As further reported, Am-241 has a half-life that is approximately five times greater than that of Pu- 238 and it has been determined that the neutron yield of a 241-AmO(sub 2) source is approximately an order of magnitude lower

  12. SL(2,R) duality-symmetric action for electromagnetic theory with electric and magnetic sources

    SciTech Connect

    Lee, Choonkyu; Min, Hyunsoo

    2013-12-15

    For the SL(2,R) duality-invariant generalization of Maxwell electrodynamics in the presence of both electric and magnetic sources, we formulate a local, manifestly duality-symmetric, Zwanziger-type action by introducing a pair of four-potentials A{sup μ} and B{sup μ} in a judicious way. On the two potentials A{sup μ} and B{sup μ} the SL(2,R) duality transformation acts in a simple linear manner. In quantum theory including charged source fields, this action can be recast as a SL(2,Z)-invariant action. Also given is a Zwanziger-type action for SL(2,R) duality-invariant Born–Infeld electrodynamics which can be important for D-brane dynamics in string theory. -- Highlights: •We formulate a local, manifestly duality-symmetric, Zwanziger-type action. •Maxwell electrodynamics is generalized to include dilaton and axion fields. •SL(2,R) symmetry is manifest. •We formulate a local, manifestly duality-symmetric, nonlinear Born–Infeld action with SL(2,R) symmetry.

  13. Energy-Water Nexus Relevant to Baseload Electricity Source Including Mini/Micro Hydropower Generation

    NASA Astrophysics Data System (ADS)

    Fujii, M.; Tanabe, S.; Yamada, M.

    2014-12-01

    Water, food and energy is three sacred treasures that are necessary for human beings. However, recent factors such as population growth and rapid increase in energy consumption have generated conflicting cases between water and energy. For example, there exist conflicts caused by enhanced energy use, such as between hydropower generation and riverine ecosystems and service water, between shale gas and ground water, between geothermal and hot spring water. This study aims to provide quantitative guidelines necessary for capacity building among various stakeholders to minimize water-energy conflicts in enhancing energy use. Among various kinds of renewable energy sources, we target baseload sources, especially focusing on renewable energy of which installation is required socially not only to reduce CO2 and other greenhouse gas emissions but to stimulate local economy. Such renewable energy sources include micro/mini hydropower and geothermal. Three municipalities in Japan, Beppu City, Obama City and Otsuchi Town are selected as primary sites of this study. Based on the calculated potential supply and demand of micro/mini hydropower generation in Beppu City, for example, we estimate the electricity of tens through hundreds of households is covered by installing new micro/mini hydropower generation plants along each river. However, the result is based on the existing infrastructures such as roads and electric lines. This means that more potentials are expected if the local society chooses options that enhance the infrastructures to increase micro/mini hydropower generation plants. In addition, further capacity building in the local society is necessary. In Japan, for example, regulations by the river law and irrigation right restrict new entry by actors to the river. Possible influences to riverine ecosystems in installing new micro/mini hydropower generation plants should also be well taken into account. Deregulation of the existing laws relevant to rivers and

  14. Eternal triangle: the interaction of light source, electrical control gear, and optics

    NASA Astrophysics Data System (ADS)

    S'heeren, Griet

    1998-04-01

    In this particular 'affair' the participants are less than human but have individual personalities they bring to their relationship with each other. High pressure metal halide lamps such as BriteArc lamps have the highest luminance and radiance of all continuously operating practical light source. Since these lamps have short arcs and are available in power ratings from about 30W to 30kW they have found applications with various optical systems. Besides the lamps, such systems include an electrical control device and an optical system. To fulfil the user's requirements for a specific application, it is not only important to choose the right lamp, but crucial to achieve a harmonious marriage between the light source, electrical control device and the optics. To run a high pressure discharge lamp an ignitor/ballast system is essential This stabilizes the lamp parameters. The chemical components inside the lamp determine the lamp voltage and the gear determines, via the current, the lamp power. These are directly related in the luminance and color temperature of the emitted light. Therefore lamp performance and effective life are dependent on the ignitor, control gear and lamp combination. Since the lamp emits radiation in all directions, collection of the light from a lamp can be improved by using reflectors to deliver the light into a lens system. Since lamps with short arc gaps approach a point source they appear ideal for optical system applications. The shape of the reflector and the focusing of the lamp determine which part of the light is collected out of the light-arc. In the case of an LCD projector, the final light output also depends on the transmission characteristics of the LCD panels. Their nonlinearity causes the color of the emitted light to be different from the lamp color. All these parameters have to be optimized to obtain the highest performance. This leads to the conclusion that a carefully matched combination of lamp, ignitor/ballast and optics

  15. Electrical source imaging of interictal spikes using multiple sparse volumetric priors for presurgical epileptogenic focus localization.

    PubMed

    Strobbe, Gregor; Carrette, Evelien; López, José David; Montes Restrepo, Victoria; Van Roost, Dirk; Meurs, Alfred; Vonck, Kristl; Boon, Paul; Vandenberghe, Stefaan; van Mierlo, Pieter

    2016-01-01

    Electrical source imaging of interictal spikes observed in EEG recordings of patients with refractory epilepsy provides useful information to localize the epileptogenic focus during the presurgical evaluation. However, the selection of the time points or time epochs of the spikes in order to estimate the origin of the activity remains a challenge. In this study, we consider a Bayesian EEG source imaging technique for distributed sources, i.e. the multiple volumetric sparse priors (MSVP) approach. The approach allows to estimate the time courses of the intensity of the sources corresponding with a specific time epoch of the spike. Based on presurgical averaged interictal spikes in six patients who were successfully treated with surgery, we estimated the time courses of the source intensities for three different time epochs: (i) an epoch starting 50 ms before the spike peak and ending at 50% of the spike peak during the rising phase of the spike, (ii) an epoch starting 50 ms before the spike peak and ending at the spike peak and (iii) an epoch containing the full spike time period starting 50 ms before the spike peak and ending 230 ms after the spike peak. To identify the primary source of the spike activity, the source with the maximum energy from 50 ms before the spike peak till 50% of the spike peak was subsequently selected for each of the time windows. For comparison, the activity at the spike peaks and at 50% of the peaks was localized using the LORETA inversion technique and an ECD approach. Both patient-specific spherical forward models and patient-specific 5-layered finite difference models were considered to evaluate the influence of the forward model. Based on the resected zones in each of the patients, extracted from post-operative MR images, we compared the distances to the resection border of the estimated activity. Using the spherical models, the distances to the resection border for the MSVP approach and each of the different time epochs were in

  16. Electrical source imaging of interictal spikes using multiple sparse volumetric priors for presurgical epileptogenic focus localization

    PubMed Central

    Strobbe, Gregor; Carrette, Evelien; López, José David; Montes Restrepo, Victoria; Van Roost, Dirk; Meurs, Alfred; Vonck, Kristl; Boon, Paul; Vandenberghe, Stefaan; van Mierlo, Pieter

    2016-01-01

    Electrical source imaging of interictal spikes observed in EEG recordings of patients with refractory epilepsy provides useful information to localize the epileptogenic focus during the presurgical evaluation. However, the selection of the time points or time epochs of the spikes in order to estimate the origin of the activity remains a challenge. In this study, we consider a Bayesian EEG source imaging technique for distributed sources, i.e. the multiple volumetric sparse priors (MSVP) approach. The approach allows to estimate the time courses of the intensity of the sources corresponding with a specific time epoch of the spike. Based on presurgical averaged interictal spikes in six patients who were successfully treated with surgery, we estimated the time courses of the source intensities for three different time epochs: (i) an epoch starting 50 ms before the spike peak and ending at 50% of the spike peak during the rising phase of the spike, (ii) an epoch starting 50 ms before the spike peak and ending at the spike peak and (iii) an epoch containing the full spike time period starting 50 ms before the spike peak and ending 230 ms after the spike peak. To identify the primary source of the spike activity, the source with the maximum energy from 50 ms before the spike peak till 50% of the spike peak was subsequently selected for each of the time windows. For comparison, the activity at the spike peaks and at 50% of the peaks was localized using the LORETA inversion technique and an ECD approach. Both patient-specific spherical forward models and patient-specific 5-layered finite difference models were considered to evaluate the influence of the forward model. Based on the resected zones in each of the patients, extracted from post-operative MR images, we compared the distances to the resection border of the estimated activity. Using the spherical models, the distances to the resection border for the MSVP approach and each of the different time epochs were in

  17. Experiments and simulations of a large area ECR source as an electric propulsion neutralizer

    NASA Astrophysics Data System (ADS)

    Hidaka, Yoshiteru

    The windowed electron cyclotron resonance (ECR) source, invented by Getty, was modified into a windowless ECR source to investigate the potential use of this device as an electron source for the neutralizer of an ion thruster system. This plasma source utilizes linear arrays of permanent magnets placed at the end of a large S-band microwave horn. These magnets are held inside a grill with alternating rows of open spaces and aluminum cross bars. The metal bars are cross-polarized so that microwave radiation transmits through the grill with low reflection. The peak electron density and electron temperature measured 1 cm from the grill surface were 5 x 1010 cm-3 and 10 eV, respectively, for 200 W input microwave power and 1 mTorr argon gas pressure. At the axial distance of 25 cm from the grill surface, these values were 1 x 1010 cm-3 and 4 eV, respectively. The extracted electron current with pulsed bias increased with collector areas and with input microwave powers, as expected, though the increase was not linear. Unexpectedly, however, the current increased as the distance of the collector from the resonance zone was increased. With microwave circuit optimization, the pulsed electron current achieved 0.77 A with a 30-V bias voltage applied to a graphite collector (7.3 cm x 10.7 cm, located 28.3 cm from the grill surface), 200 W input microwave power, and 1 mTorr argon gas pressure. For DC extraction with the same settings, an electron current of 0.51 A was extracted. The 2D simulations using the MAGIC computer code demonstrated electrons gain energy only near the ECR zone (875 gauss contour). The effectiveness of the steel pole pieces designed for the windowless Getty source was also confirmed. The curvature in either electric or magnetic field profile was verified as a necessary condition for ECR to take place. Electron trajectory plots using the TriComp computer code showed electron trapping by the magnetic mirrors. Both experiments and simulations indicated that

  18. Saga is largest commercial submarine ever

    SciTech Connect

    Not Available

    1985-05-01

    The long-range autonomous submarine, Saga, went nuclear last year with an agreement between the French and two Canadian companies. The agreement to convert the prototype from Swedish Stirling closed-cycle combustion engines to a nuclear power supply will make Saga the first non-defense nuclear submarine. With an external hull displacement of 500 tons, Saga will be the largest commercial submarine ever built.

  19. The World's Largest Photovoltaic Concentrator System.

    ERIC Educational Resources Information Center

    Smith, Harry V.

    1982-01-01

    The Mississippi County Community College large-scale energy experiment, featuring the emerging high technology of solar electricity, is described. The project includes a building designed for solar electricity and a power plant consisting of a total energy photovoltaic system, and features two experimental developments. (MLW)

  20. Electrohydrodynamics of Charge Separation in Droplet-Based Ion Sources with Time-Varying Electrical and Mechanical Actuation

    PubMed Central

    Forbes, Thomas P.; Degertekin, F. Levent; Fedorov, Andrei G.

    2010-01-01

    Charge transport and separation in mechanically-driven, droplet-based ion sources are investigated using computational analysis and supporting experiments. A first-principles model of electrohydrodynamics (EHD) and charge migration is formulated and implemented using FLUENT CFD software for jet/droplet formation. For validation, classical experiments of electrospraying from a thin capillary are simulated, specifically, the transient EHD cone-jet formation of a fluid with finite electrical conductivity, and the Taylor cone formation in a perfectly electrically-conducting fluid. The model is also used to investigate the microscopic physics of droplet charging in mechanically-driven droplet-based ion sources, such as AMUSE (Array of Micromachined UltraSonic Electrospray). Here, AMUSE is subject to DC and AC electric fields of varying amplitude and phase, with respect to a time-varying mechanical force driving the droplet formation. For the DC-charging case, a linear relationship is demonstrated between the charge carried by each droplet and an applied electric field magnitude, in agreement with previously reported experiments. For the AC-charging case, a judiciously-chosen phase-shift in the time-varying mechanical (driving ejection) and electrical (driving charge transport) signals allows for a significantly increased amount of charge, of desired polarity, to be pumped into a droplet upon ejection. Complementary experimental measurements of electrospray electrical current and charge-per-droplet, produced by the AMUSE ion source, are performed and support theoretical predictions for both DC and AC-charging cases. The theoretical model and simulation tools provide a versatile and general analytical framework for fundamental investigations of coupled electrohydrodynamics and charge transport. The model also allows for the exploration of different configurations and operating modes to optimize charge separation in atmospheric pressure electrohydrodynamic ion sources

  1. An interpretation of induced electric currents in long pipelines caused by natural geomagnetic sources of the upper atmosphere

    USGS Publications Warehouse

    Campbell, W.H.

    1986-01-01

    Electric currents in long pipelines can contribute to corrosion effects that limit the pipe's lifetime. One cause of such electric currents is the geomagnetic field variations that have sources in the Earth's upper atmosphere. Knowledge of the general behavior of the sources allows a prediction of the occurrence times, favorable locations for the pipeline effects, and long-term projections of corrosion contributions. The source spectral characteristics, the Earth's conductivity profile, and a corrosion-frequency dependence limit the period range of the natural field changes that affect the pipe. The corrosion contribution by induced currents from geomagnetic sources should be evaluated for pipelines that are located at high and at equatorial latitudes. At midlatitude locations, the times of these natural current maxima should be avoided for the necessary accurate monitoring of the pipe-to-soil potential. ?? 1986 D. Reidel Publishing Company.

  2. What Is the Largest Einstein Radius in the Universe?

    SciTech Connect

    Oguri, Masamune; Blandford, Roger D.

    2008-08-05

    The Einstein radius plays a central role in lens studies as it characterizes the strength of gravitational lensing. In particular, the distribution of Einstein radii near the upper cutoff should probe the probability distribution of the largest mass concentrations in the universe. Adopting a triaxial halo model, we compute expected distributions of large Einstein radii. To assess the cosmic variance, we generate a number of Monte-Carlo realizations of all-sky catalogues of massive clusters. We find that the expected largest Einstein radius in the universe is sensitive to parameters characterizing the cosmological model, especially {sigma}{sub s}: for a source redshift of unity, they are 42{sub -7}{sup +9}, 35{sub -6}{sup +8}, and 54{sub -7}{sup +12} arcseconds (errors denote 1{sigma} cosmic variance), assuming best-fit cosmological parameters of the Wilkinson Microwave Anisotropy Probe five-year (WMAP5), three-year (WMAP3) and one-year (WMAP1) data, respectively. These values are broadly consistent with current observations given their incompleteness. The mass of the largest lens cluster can be as small as {approx} 10{sup 15} M{sub {circle_dot}}. For the same source redshift, we expect in all-sky {approx} 35 (WMAP5), {approx} 15 (WMAP3), and {approx} 150 (WMAP1) clusters that have Einstein radii larger than 2000. For a larger source redshift of 7, the largest Einstein radii grow approximately twice as large. While the values of the largest Einstein radii are almost unaffected by the level of the primordial non-Gaussianity currently of interest, the measurement of the abundance of moderately large lens clusters should probe non-Gaussianity competitively with cosmic microwave background experiments, but only if other cosmological parameters are well-measured. These semi-analytic predictions are based on a rather simple representation of clusters, and hence calibrating them with N-body simulations will help to improve the accuracy. We also find that these 'superlens

  3. Reverse electrodialysis using bipolar ion-exchange membranes as a source of electric energy

    SciTech Connect

    Pivovarov, N.Ya.; Greben`, V.P.; Kovarskii, N.Ya.

    1994-06-01

    It is established that, in the regime of the H{sup +} and OH{sup {minus}} ions recombination, voltage on the bipolar membranes and the efficiency of the latter, as a transformer of chemical energy into electric, increases in the series of ionogen groups contained in the bipolar region. This is due to an increase in the recombination rate constants in the bipolar contact for the H{sup +} and OH{sup {minus}} ions. As the sodium and chlorine ions penetrate the bipolar transition region, they sharply decrease the membrane potential and the voltage drop on the bipolar membranes, because the ionogen groups turn into salt form, which is catalytically inactive in the H{sup +} and OH{sup {minus}} ions recombination reaction. It is shown that the source of current, containing the MB-24 (bipolar), MF-4sk (cation-exchange), and AMV (anion-exchange) ion-exchange membranes, has a specific power of 0.11 W/dm{sup 2} (calculated in terms of one bipolar membrane) and efficiency of 29% for 0.5 M solution of hydrochloric acid and sodium hydroxide, and 0.5 A/dm{sup 2} current density.

  4. Effects of Au source/drain thickness on electrical characteristics of pentacene thin-film transistors

    NASA Astrophysics Data System (ADS)

    Kwon, Jin-Hyuk; Hahn, Joonku; Bae, Jin-Hyuk; Ham, Youngjin; Park, Jaehoon; Baang, Sungkeun

    2015-11-01

    We investigate the electrical characteristics of top-contact pentacene thin-film transistors (TFTs) fabricated with various thicknesses of the Au source and the drain (S/D) electrodes, i.e., 20, 30, 50, 70, and 105 nm. Pentacene TFTs exhibit enhancements in the drain current and the fieldeffect mobility with increasing thickness of Au S/D electrodes up to 50 nm, after which the TFT performance degrades with increasing Au thickness. A transmission line method is used to analyze the contact resistance between the Au electrode and the pentacene layer in the TFTs, and ultraviolet photoemission spectroscopy measurements are performed to determine the work function of the Au films. The lowest contact resistance, 73 kΩ·cm, is obtained for the 50-nm-thick Au case and is ascribed to the high work function (4.67 eV) of the film. Consequently, the effects of the Au S/D thickness on the performance of top-contact pentacene TFTs can be understood through the behavior of the charge injection at the Au electrode/pentacene interface.

  5. Promoting electricity from renewable energy sources -- lessons learned from the EU, U.S. and Japan

    SciTech Connect

    Haas, Reinhard; Meyer, Niels I.; Held, Anne; Finon, Dominique; Lorenzoni, Arturo; Wiser, Ryan; Nishio, Ken-ichiro

    2007-06-01

    The promotion of electricity generated from Renewable Energy Sources (RES) has recently gained high priority in the energy policy strategies of many countries in response to concerns about global climate change, energy security and other reasons. This chapter compares and contrasts the experience of a number of countries in Europe, states in the US as well as Japan in promoting RES, identifying what appear to be the most successful policy measures. Clearly, a wide range of policy instruments have been tried and are in place in different parts of the world to promote renewable energy technologies. The design and performance of these schemes varies from place to place, requiring further research to determine their effectiveness in delivering the desired results. The main conclusions that can be drawn from the present analysis are: (1) Generally speaking, promotional schemes that are properly designed within a stable framework and offer long-term investment continuity produce better results. Credibility and continuity reduce risks thus leading to lower profit requirements by investors. (2) Despite their significant growth in absolute terms in a number of key markets, the near-term prognosis for renewables is one of modest success if measured in terms of the percentage of the total energy provided by renewables on a world-wide basis. This is a significant challenge, suggesting that renewables have to grow at an even faster pace if we expect them to contribute on a significant scale to the world's energy mix.

  6. A system for mapping sources of VHF and electric field pulses from in-cloud lightning at KSC

    NASA Technical Reports Server (NTRS)

    Thomson, Ewen M.; Medelius, Pedro J.

    1991-01-01

    The literature concerning VHF radiation and wideband electric fields from in-cloud lightning is reviewed. VHF location systems give impressive radio images of lightning in clouds with high spatial and temporal resolution. Using systems based on long and short baseline time-or-arrival and interferometry, workers have detected VHF sources that move at speeds of 10(exp 5) to 10(exp 8) m/s. The more slowly moving sources appear to be associated with channel formation but the physical basis for the higher speeds is not clear. In contrast, wideband electric fields are directly related to physical parameters such as current and tortuosity. A long baseline system is described to measure simultaneously VHF radiation and wideband electric fields at five stations at Kennedy Space Center. All signals are detected over remote, isolated ground planes with fiber optics for data transmission. The modification of this system to map rapidly varying dE/dt pulses is discussed.

  7. Flight performance of the largest volant bird

    PubMed Central

    Ksepka, Daniel T.

    2014-01-01

    Pelagornithidae is an extinct clade of birds characterized by bizarre tooth-like bony projections of the jaws. Here, the flight capabilities of pelagornithids are explored based on data from a species with the largest reported wingspan among birds. Pelagornis sandersi sp. nov. is represented by a skull and substantial postcranial material. Conservative wingspan estimates (∼6.4 m) exceed theoretical maximums based on extant soaring birds. Modeled flight properties indicate that lift:drag ratios and glide ratios for P. sandersi were near the upper limit observed in extant birds and suggest that pelagornithids were highly efficient gliders, exploiting a long-range soaring ecology. PMID:25002475

  8. Fiji's largest marine reserve benefits reef sharks

    NASA Astrophysics Data System (ADS)

    Goetze, J. S.; Fullwood, L. A. F.

    2013-03-01

    To provide more information about whether sharks benefit from no-take marine reserves, we quantified the relative abundance and biomass of reef sharks inside and outside of Namena, Fiji's largest reserve (60.6 km2). Using stereo baited remote underwater video systems (stereo-BRUVs), we found that the abundance and biomass of sharks was approximately two and four times greater in shallow and deep locations, respectively, within the Namena reserve compared to adjacent fished areas. The greater abundance and biomass of reef sharks inside Namena is likely a result of greater prey availability rather than protection from fishing. This study demonstrates that marine reserves can benefit sharks.

  9. Novel MSVPWM to Reduce the Inductor Current Ripple for Z-Source Inverter in Electric Vehicle Applications

    PubMed Central

    Zhang, Qianfan; Dong, Shuai; Xue, Ping; Zhou, Chaowei; Cheng, ShuKang

    2014-01-01

    A novel modified space vector pulse width modulation (MSVPWM) strategy for Z-Source inverter is presented. By rearranging the position of shoot-through states, the frequency of inductor current ripple is kept constant. Compared with existing MSVPWM strategies, the proposed approach can reduce the maximum inductor current ripple. So the volume of Z-source network inductor can be designed smaller, which brings the beneficial effect on the miniaturization of the electric vehicle controller. Theoretical findings in the novel MSVPWM for Z-Source inverter have been verified by experiment results. PMID:24883412

  10. Novel MSVPWM to reduce the inductor current ripple for Z-source inverter in electric vehicle applications.

    PubMed

    Zhang, Qianfan; Dong, Shuai; Xue, Ping; Zhou, Chaowei; Cheng, ShuKang

    2014-01-01

    A novel modified space vector pulse width modulation (MSVPWM) strategy for Z-Source inverter is presented. By rearranging the position of shoot-through states, the frequency of inductor current ripple is kept constant. Compared with existing MSVPWM strategies, the proposed approach can reduce the maximum inductor current ripple. So the volume of Z-source network inductor can be designed smaller, which brings the beneficial effect on the miniaturization of the electric vehicle controller. Theoretical findings in the novel MSVPWM for Z-Source inverter have been verified by experiment results. PMID:24883412

  11. A new electrical and mechanically detonatable shear wave source for near surface (0-30 m) seismic acquisition

    NASA Astrophysics Data System (ADS)

    Crane, J. M.; Lorenzo, J. M.; Harris, J. B.

    2013-04-01

    We present a new, impulsive, horizontal shear source capable of performing long shot profiles in a time-efficient and repeatable manner. The new shear source is ground-coupled by eight 1/2″ (1.27 cm) × 2″ (5.08 cm) steel spikes. Blank shotshells (12-gauge) used as energy sources can be either mechanically or electrically detonated. Electrical fuses have a start time repeatability of < 50 μs. This source can be operated by a single individual, and takes only ~ 10 s between shots as opposed to ~ 30 s for six stacked hammer blows. To ensure complete safety, the shotshell holder is surrounded by a protective 6″ (15.24 cm)-thick barrel, a push-and-twist-locked breach, and a safety pin. We conducted field tests at the 17th Street Canal levee breach site in New Orleans, Louisiana (30.017° N 90.121° W) and at an instrumented test borehole at Millsaps College in Jackson, Mississippi (32.325° N 93.182° W) to compare our new source and a traditional hammer impact source. The new shear source produces a broader-band of frequencies (30-100 Hz cf. 30-60 Hz). Signal generated by the new shear source has signal-to-noise ratios equivalent to ~ 3 stacked hammer blows to the hammer impact source. Ideal source signals must be broadband in frequency, have a high SNR, be consistent, and have precise start times; all traits of the new shear source.

  12. Applicability of the single equivalent point dipole model to represent a spatially distributed bio-electrical source

    NASA Technical Reports Server (NTRS)

    Armoundas, A. A.; Feldman, A. B.; Sherman, D. A.; Cohen, R. J.

    2001-01-01

    Although the single equivalent point dipole model has been used to represent well-localised bio-electrical sources, in realistic situations the source is distributed. Consequently, position estimates of point dipoles determined by inverse algorithms suffer from systematic error due to the non-exact applicability of the inverse model. In realistic situations, this systematic error cannot be avoided, a limitation that is independent of the complexity of the torso model used. This study quantitatively investigates the intrinsic limitations in the assignment of a location to the equivalent dipole due to distributed electrical source. To simulate arrhythmic activity in the heart, a model of a wave of depolarisation spreading from a focal source over the surface of a spherical shell is used. The activity is represented by a sequence of concentric belt sources (obtained by slicing the shell with a sequence of parallel plane pairs), with constant dipole moment per unit length (circumferentially) directed parallel to the propagation direction. The distributed source is represented by N dipoles at equal arc lengths along the belt. The sum of the dipole potentials is calculated at predefined electrode locations. The inverse problem involves finding a single equivalent point dipole that best reproduces the electrode potentials due to the distributed source. The inverse problem is implemented by minimising the chi2 per degree of freedom. It is found that the trajectory traced by the equivalent dipole is sensitive to the location of the spherical shell relative to the fixed electrodes. It is shown that this trajectory does not coincide with the sequence of geometrical centres of the consecutive belt sources. For distributed sources within a bounded spherical medium, displaced from the sphere's centre by 40% of the sphere's radius, it is found that the error in the equivalent dipole location varies from 3 to 20% for sources with size between 5 and 50% of the sphere's radius

  13. Electricity use patterns in cotton gins

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Energy costs are the second largest source of variable costs for cotton gins, with electricity accounting for 18% of variable costs. Energy use has typically not been a major consideration in gin design and previous studies of energy use have utilized instantaneous readings or aggregated season-lon...

  14. A wavelet-based baseline drift correction method for grounded electrical source airborne transient electromagnetic signals

    NASA Astrophysics Data System (ADS)

    Wang, Yuan 1Ji, Yanju 2Li, Suyi 13Lin, Jun 12Zhou, Fengdao 1Yang, Guihong

    2013-09-01

    A grounded electrical source airborne transient electromagnetic (GREATEM) system on an airship enjoys high depth of prospecting and spatial resolution, as well as outstanding detection efficiency and easy flight control. However, the movement and swing of the front-fixed receiving coil can cause severe baseline drift, leading to inferior resistivity image formation. Consequently, the reduction of baseline drift of GREATEM is of vital importance to inversion explanation. To correct the baseline drift, a traditional interpolation method estimates the baseline `envelope' using the linear interpolation between the calculated start and end points of all cycles, and obtains the corrected signal by subtracting the envelope from the original signal. However, the effectiveness and efficiency of the removal is found to be low. Considering the characteristics of the baseline drift in GREATEM data, this study proposes a wavelet-based method based on multi-resolution analysis. The optimal wavelet basis and decomposition levels are determined through the iterative comparison of trial and error. This application uses the sym8 wavelet with 10 decomposition levels, and obtains the approximation at level-10 as the baseline drift, then gets the corrected signal by removing the estimated baseline drift from the original signal. To examine the performance of our proposed method, we establish a dipping sheet model and calculate the theoretical response. Through simulations, we compare the signal-to-noise ratio, signal distortion, and processing speed of the wavelet-based method and those of the interpolation method. Simulation results show that the wavelet-based method outperforms the interpolation method. We also use field data to evaluate the methods, compare the depth section images of apparent resistivity using the original signal, the interpolation-corrected signal and the wavelet-corrected signal, respectively. The results confirm that our proposed wavelet-based method is an

  15. Electrical slow waves in the mouse oviduct are dependent on extracellular and intracellular calcium sources

    PubMed Central

    Dixon, Rose Ellen; Britton, Fiona C.; Baker, Salah A.; Hennig, Grant W.; Rollings, Christina M.; Sanders, Kenton M.

    2011-01-01

    Spontaneous contractions of the myosalpinx are critical for oocyte transport along the oviduct. Slow waves, the electrical events that underlie myosalpinx contractions, are generated by a specialized network of pacemaker cells called oviduct interstitial cells of Cajal (ICC-OVI). The ionic basis of oviduct pacemaker activity is unknown. Intracellular recordings and Ca2+ imaging were performed to examine the role of extracellular and intracellular Ca2+ sources in slow wave generation. RT-PCR was performed to determine the transcriptional expression of Ca2+ channels. Molecular studies revealed most isoforms of L- and T-type calcium channels (Cav1.2,1.3,1.4,3.1,3.2,3.3) were expressed in myosalpinx. Reduction of extracellular Ca2+ concentration ([Ca2+]o) resulted in the abolition of slow waves and myosalpinx contractions without significantly affecting resting membrane potential (RMP). Spontaneous Ca2+ waves spread through ICC-OVI cells at a similar frequency to slow waves and were inhibited by reduced [Ca2+]o. Nifedipine depolarized RMP and inhibited slow waves; however, pacemaker activity returned when the membrane was repolarized with reduced extracellular K+ concentration ([K+]o). Ni2+ also depolarized RMP but failed to block slow waves. The importance of ryanodine and inositol 1,4,5 trisphosphate-sensitive stores were examined using ryanodine, tetracaine, caffeine, and 2-aminoethyl diphenylborinate. Results suggest that although both stores are involved in regulation of slow wave frequency, neither are exclusively essential. The sarco/endoplasmic reticulum Ca2+-ATPase (SERCA) pump inhibitor cyclopiazonic acid inhibited pacemaker activity and Ca2+ waves suggesting that a functional SERCA pump is necessary for pacemaker activity. In conclusion, results from this study suggest that slow wave generation in the oviduct is voltage dependent, occurs in a membrane potential window, and is dependent on extracellular calcium and functional SERCA pumps. PMID:21881003

  16. General Electric PETtrace cyclotron as a neutron source for boron neutron capture therapy

    NASA Astrophysics Data System (ADS)

    Bosko, Andrey

    This research investigates the use of a PETtrace cyclotron produced by General Electric (GE) as a neutron source for boron neutron capture therapy (BNCT). The GE PETtrace was chosen for this investigation because this type of cyclotron is popular among nuclear pharmacies and clinics in many countries; it is compact and reliable; it produces protons with energies high enough to produce neutrons with appropriate energy and fluence rate for BNCT and it does not require significant changes in design to provide neutrons. In particular, the standard PETtrace 18O target is considered. The cyclotron efficiency may be significantly increased if unused neutrons produced during radioisotopes production could be utilized for other medical modalities such as BNCT at the same time. The resulting dose from the radiation emitted from the target is evaluated using the Monte Carlo radiation transport code MCNP at several depths in a brain phantom for different scattering geometries. Four different moderating materials of various thicknesses were considered: light water, carbon, heavy water, arid Fluental(TM). The fluence rate tally was used to calculate photon and neutron dose, by applying fluence rate-to-dose conversion factors. Fifteen different geometries were considered and a 30-cm thick heavy water moderator was chosen as the most suitable for BNCT with the GE PETtrace cyclotron. According to the Brookhaven Medical Research Reactor (BMRR) protocol, the maximum dose to the normal brain is set to 12.5 RBEGy, which for the conditions of using a heavy water moderator, assuming a 60 muA beam current, would be reached with a treatment time of 258 min. Results showed that using a PETtrace cyclotron in this configuration provides a therapeutic ratio of about 2.4 for depths up to 4 cm inside a brain phantom. Further increase of beam current proposed by GE should significantly improve the beam quality or the treatment time and allow treating tumors at greater depths.

  17. Wind energy as a significant source of electricity for the United States

    SciTech Connect

    Nix, R.G.

    1996-06-01

    This paper discusses wind energy and its potential to significantly impact the generation of electricity within the US. The principles and the equipment used to convert wind energy to electricity are described, as is the status of current technology. Markets and production projections are given. There is discussion of the advances required to reduce the selling cost of electricity generated from the wind from today`s price of about $0.05 per kilowatt-hour to full cost-competitiveness with gas- and coal-based electricity.

  18. Collapse of the world's largest herbivores.

    PubMed

    Ripple, William J; Newsome, Thomas M; Wolf, Christopher; Dirzo, Rodolfo; Everatt, Kristoffer T; Galetti, Mauro; Hayward, Matt W; Kerley, Graham I H; Levi, Taal; Lindsey, Peter A; Macdonald, David W; Malhi, Yadvinder; Painter, Luke E; Sandom, Christopher J; Terborgh, John; Van Valkenburgh, Blaire

    2015-05-01

    Large wild herbivores are crucial to ecosystems and human societies. We highlight the 74 largest terrestrial herbivore species on Earth (body mass ≥100 kg), the threats they face, their important and often overlooked ecosystem effects, and the conservation efforts needed to save them and their predators from extinction. Large herbivores are generally facing dramatic population declines and range contractions, such that ~60% are threatened with extinction. Nearly all threatened species are in developing countries, where major threats include hunting, land-use change, and resource depression by livestock. Loss of large herbivores can have cascading effects on other species including large carnivores, scavengers, mesoherbivores, small mammals, and ecological processes involving vegetation, hydrology, nutrient cycling, and fire regimes. The rate of large herbivore decline suggests that ever-larger swaths of the world will soon lack many of the vital ecological services these animals provide, resulting in enormous ecological and social costs. PMID:26601172

  19. Coherence properties of the electric field generated by an incoherent source of currents distributed on the surface of a sphere.

    PubMed

    Zurita-Sánchez, Jorge R

    2016-01-01

    We derive analytical expressions of the cross-spectral density of the electric field arising from an incoherent source whose current density is located on the surface of a sphere. Our approach is based on the series expansion in terms of vector spherical harmonics of the electric field generated by the aforementioned current distribution. We analyze in detail the spectrum, the degree of coherence, and the degree of polarization of the electric field for all regions in space (from the near field to the far field). The relationship of the high-order harmonics to the coherence properties is discussed. The spectrum turns out to be isotropic and it is different from that of the source. We found that the degree of coherence and degree of polarization are strongly influenced by the size of the source. We show the appearance of special features: a zone with a high degree of coherence in the near field for a subwavelength source, the radial degree of coherence is nearly constant in an extended region where two radial points belong to the far field, and a particular radial distance for which the degree of polarization vanishes (3D unpolarized light). PMID:26831593

  20. Limited electricity access in health facilities of sub-Saharan Africa: a systematic review of data on electricity access, sources, and reliability

    PubMed Central

    Adair-Rohani, Heather; Zukor, Karen; Bonjour, Sophie; Wilburn, Susan; Kuesel, Annette C; Hebert, Ryan; Fletcher, Elaine R

    2013-01-01

    ABSTRACT Background: Access to electricity is critical to health care delivery and to the overarching goal of universal health coverage. Data on electricity access in health care facilities are rarely collected and have never been reported systematically in a multi-country study. We conducted a systematic review of available national data on electricity access in health care facilities in sub-Saharan Africa. Methods: We identified publicly-available data from nationally representative facility surveys through a systematic review of articles in PubMed, as well as through websites of development agencies, ministries of health, and national statistics bureaus. To be included in our analysis, data sets had to be collected in or after 2000, be nationally representative of a sub-Saharan African country, cover both public and private health facilities, and include a clear definition of electricity access. Results: We identified 13 health facility surveys from 11 sub-Saharan African countries that met our inclusion criteria. On average, 26% of health facilities in the surveyed countries reported no access to electricity. Only 28% of health care facilities, on average, had reliable electricity among the 8 countries reporting data. Among 9 countries, an average of 7% of facilities relied solely on a generator. Electricity access in health care facilities increased by 1.5% annually in Kenya between 2004 and 2010, and by 4% annually in Rwanda between 2001 and 2007. Conclusions: Energy access for health care facilities in sub-Saharan African countries varies considerably. An urgent need exists to improve the geographic coverage, quality, and frequency of data collection on energy access in health care facilities. Standardized tools should be used to collect data on all sources of power and supply reliability. The United Nations Secretary-General's “Sustainable Energy for All” initiative provides an opportunity to comprehensively monitor energy access in health care

  1. Water, Sanitation, and Hygiene at the World's Largest Mass Gathering.

    PubMed

    Vortmann, Michael; Balsari, Satchit; Holman, Susan R; Greenough, P Gregg

    2015-02-01

    The 2013 Kumbh Mela, a Hindu religious festival and the largest human gathering on earth, drew an estimated 120 million pilgrims to bathe at the holy confluence of the Ganga (Ganges) and Yamuna rivers. To accommodate the massive numbers, the Indian government constructed a temporary city on the flood plains of the two rivers and provided it with roads, electricity, water and sanitation facilities, police stations, and a tiered healthcare system. This phenomenal operation and its impacts have gone largely undocumented. To address this gap, the authors undertook an evaluation and systematic monitoring initiative to study preparedness and response to public health emergencies at the event. This paper describes the water, sanitation, and hygiene components, with particular emphasis on preventive and mitigation strategies; the capacity for surveillance and response to diarrheal disease outbreaks; and the implications of lessons learned for other mass gatherings. PMID:25783442

  2. DEVELOPMENTAL CHANGES IN FACT AND SOURCE RECALL: CONTRIBUTIONS FROM EXECUTIVE FUNCTION AND BRAIN ELECTRICAL ACTIVITY

    PubMed Central

    Rajan, Vinaya; Bell, Martha Ann

    2014-01-01

    Source memory involves recollecting the contextual details surrounding a memory episode. When source information is bound together, it makes a memory episodic in nature. Unfortunately, very little is known about the factors that contribute to its formation in early development. This study examined the development of source memory in middle childhood. Measures of executive function were examined as potential sources of variation in fact and source recall. Continuous electroencephalogram (EEG) measures were collected during baseline and fact and source retrieval in order to examine memory-related changes in EEG power. Six and 8-year-old children were taught 10 novel facts from two different sources and recall for fact and source information was later tested. Older children were better on fact recall, but both ages were comparable on source recall. However, source recall performance was poor at both ages, suggesting that this ability continues to develop beyond middle childhood. Regression analyses revealed that executive function uniquely predicted variance in source recall performance. Task-related increases in theta power were observed at frontal, temporal and parietal electrode sites during fact and source retrieval. This investigation contributes to our understanding of age-related differences in source memory processing in middle childhood. PMID:25459873

  3. Evaluating the value of concentrated solar power in electricity systems with fluctuating energy sources

    NASA Astrophysics Data System (ADS)

    Lunz, Benedikt; Stöcker, Philipp; Pitz-Paal, Robert; Sauer, Dirk Uwe

    2016-05-01

    The paper presents a method for evaluating the value of CSP in electricity systems in comparison to other technologies. The low parametrization effort of the presented model allows for conducting studies for different electricity systems and scenarios within a manageable time frame. CSP systems in possible German electricity systems in the year 2050 can be used at its best, when the share of fluctuating renewables (FRES) is low. Under these conditions CSP is a cost-effective solution to meet CO2-reduction goals of 90 % in comparison to 1990. With FRES shares above 70 % the utilization of CSP systems would be too low to be competitive.

  4. Fluctuations of Electrical Conductivity: A New Source for Astrophysical Magnetic Fields

    NASA Astrophysics Data System (ADS)

    Pétrélis, F.; Alexakis, A.; Gissinger, C.

    2016-04-01

    We consider the generation of a magnetic field by the flow of a fluid for which the electrical conductivity is nonuniform. A new amplification mechanism is found which leads to dynamo action for flows much simpler than those considered so far. In particular, the fluctuations of the electrical conductivity provide a way to bypass antidynamo theorems. For astrophysical objects, we show through three-dimensional global numerical simulations that the temperature-driven fluctuations of the electrical conductivity can amplify an otherwise decaying large scale equatorial dipolar field. This effect could play a role for the generation of the unusually tilted magnetic field of the iced giants Neptune and Uranus.

  5. Fluctuations of Electrical Conductivity: A New Source for Astrophysical Magnetic Fields.

    PubMed

    Pétrélis, F; Alexakis, A; Gissinger, C

    2016-04-22

    We consider the generation of a magnetic field by the flow of a fluid for which the electrical conductivity is nonuniform. A new amplification mechanism is found which leads to dynamo action for flows much simpler than those considered so far. In particular, the fluctuations of the electrical conductivity provide a way to bypass antidynamo theorems. For astrophysical objects, we show through three-dimensional global numerical simulations that the temperature-driven fluctuations of the electrical conductivity can amplify an otherwise decaying large scale equatorial dipolar field. This effect could play a role for the generation of the unusually tilted magnetic field of the iced giants Neptune and Uranus. PMID:27152784

  6. REVISED EMISSIONS ESTIMATION METHODOLOGIES FOR INDUSTRIAL, RESIDENTIAL, AND ELECTRIC UTILITY STATIONARY COMBUSTION SOURCES

    EPA Science Inventory

    The report describes the development of improved and streamlined EPA emission estimation methods for stationary combustion area sources by the Joint Emissions Inventory Oversight Group (JEIOG) research program. hese sources include categories traditionally labeled "other stationa...

  7. REVISED EMISSIONS ESTIMATION METHODOLOGIES FOR INDUSTRIAL, RESIDENTIAL, AND ELECTRIC UTILITY STATIONARY COMBUSTION SOURCES

    EPA Science Inventory

    The report describes the development of improved and streamlined EPA emission estimation methods for stationary combustion area sources by the Joint Emissions Inventory Oversight Group (JEIOG) research program. These sources include categories traditionally labeled "other statio...

  8. Hybrid Design of Electric Power Generation Systems Including Renewable Sources of Energy

    ERIC Educational Resources Information Center

    Wang, Lingfeng; Singh, Chanan

    2008-01-01

    With the stricter environmental regulations and diminishing fossil-fuel reserves, there is now higher emphasis on exploiting various renewable sources of energy. These alternative sources of energy are usually environmentally friendly and emit no pollutants. However, the capital investments for those renewable sources of energy are normally high,…

  9. Analysis of renewable energy sources and electric vehicle penetration into energy systems predominantly based on lignite

    NASA Astrophysics Data System (ADS)

    Dedinec, A.; Jovanovski, B.; Gajduk, A.; Markovska, N.; Kocarev, L.

    2016-05-01

    We consider an integration of renewable energy into transport and electricity sectors through vehicle to grid (V2G) technologies for an energy system that is predominantly based on lignite. The national energy system of Macedonia is modeled using EnergyPLAN which integrates energy for electricity, transport and heat, and includes hourly fluctuations in human needs and the environment. We show that electric-vehicles can provide the necessary storage enabling a fully renewable energy profile for Macedonia that can match the country's growing demand for energy. Furthermore, a large penetration of electric vehicles leads to a dramatic reduction of 47% of small particles and other air pollutants generated by car traffic in 2050.

  10. JEA successfully completes world's largest CFB demonstration

    SciTech Connect

    2005-09-30

    JEA (formerly the Jacksonville Electric Authority) has successfully completed an eighth year landmark demonstration project that continues in baseload commercial operation. It scales up atmospheric fluidized-bed technology demonstration to the near-300-MW size, providing important data on a technology that can achieve > 90% SO{sub 2} removal and 60% NOx reduction at relatively high efficiencies and at costs comparable to those of conventional pulverized coal plants. The article recounts the history of the project. Performance tests showed a blend of coal and petcoke were most efficient as a feedstock. 3 figs.

  11. Atmospheric Pressure Ion Source Development: Experimental Validation of Simulated Ion Trajectories within Complex Flow and Electrical Fields

    NASA Astrophysics Data System (ADS)

    Wissdorf, Walter; Lorenz, Matthias; Pöhler, Thorsten; Hönen, Herwart; Benter, Thorsten

    2013-10-01

    Three-dimensionally (3D) resolved ion trajectory calculations within the complex viscous flow field of an atmospheric pressure ion source are presented. The model calculations are validated with spatially resolved measurements of the relative sensitivity distribution within the source enclosure, referred to as the distribution of ion acceptance (DIA) of the mass analyzer. In previous work, we have shown that the DIA shapes as well as the maximum signal strengths strongly depend on ion source operational parameters such as gas flows and temperatures, as well as electrical field gradients established by various source electrode potentials (e.g., capillary inlet port potential and spray shield potential). In all cases studied, distinct, reproducible, and, to some extent, surprising DIA patterns were observed. We have thus attempted to model selected experimental operational source modes (called operational points) using a validated computational flow dynamics derived 3D-velocity field as an input parameter set for SIMION/SDS, along with a suite of custom software for data analysis and parameter set processing. Despite the complexity of the system, the modeling results reproduce the experimentally derived DIA unexpectedly well. It is concluded that SIMION/SDS in combination with accurate computational fluid dynamics (CFD) input data and adequate analysis software is capable of successfully modeling operational points of an atmospheric pressure ion (API) source. This approach should be very useful in the computer-aided design of future API sources.

  12. The largest volcanic eruptions on Earth

    NASA Astrophysics Data System (ADS)

    Bryan, Scott E.; Peate, Ingrid Ukstins; Peate, David W.; Self, Stephen; Jerram, Dougal A.; Mawby, Michael R.; Marsh, J. S. (Goonie); Miller, Jodie A.

    2010-10-01

    Large igneous provinces (LIPs) are sites of the most frequently recurring, largest volume basaltic and silicic eruptions in Earth history. These large-volume (> 1000 km 3 dense rock equivalent) and large-magnitude (> M8) eruptions produce areally extensive (10 4-10 5 km 2) basaltic lava flow fields and silicic ignimbrites that are the main building blocks of LIPs. Available information on the largest eruptive units are primarily from the Columbia River and Deccan provinces for the dimensions of flood basalt eruptions, and the Paraná-Etendeka and Afro-Arabian provinces for the silicic ignimbrite eruptions. In addition, three large-volume (675-2000 km 3) silicic lava flows have also been mapped out in the Proterozoic Gawler Range province (Australia), an interpreted LIP remnant. Magma volumes of > 1000 km 3 have also been emplaced as high-level basaltic and rhyolitic sills in LIPs. The data sets indicate comparable eruption magnitudes between the basaltic and silicic eruptions, but due to considerable volumes residing as co-ignimbrite ash deposits, the current volume constraints for the silicic ignimbrite eruptions may be considerably underestimated. Magma composition thus appears to be no barrier to the volume of magma emitted during an individual eruption. Despite this general similarity in magnitude, flood basaltic and silicic eruptions are very different in terms of eruption style, duration, intensity, vent configuration, and emplacement style. Flood basaltic eruptions are dominantly effusive and Hawaiian-Strombolian in style, with magma discharge rates of ~ 10 6-10 8 kg s -1 and eruption durations estimated at years to tens of years that emplace dominantly compound pahoehoe lava flow fields. Effusive and fissural eruptions have also emplaced some large-volume silicic lavas, but discharge rates are unknown, and may be up to an order of magnitude greater than those of flood basalt lava eruptions for emplacement to be on realistic time scales (< 10 years). Most

  13. The largest volcanic eruptions on Earth

    NASA Astrophysics Data System (ADS)

    Bryan, Scott E.; Peate, Ingrid Ukstins; Peate, David W.; Self, Stephen; Jerram, Dougal A.; Mawby, Michael R.; Marsh, J. S. (Goonie); Miller, Jodie A.

    2010-10-01

    Large igneous provinces (LIPs) are sites of the most frequently recurring, largest volume basaltic and silicic eruptions in Earth history. These large-volume (> 1000 km 3 dense rock equivalent) and large-magnitude (> M8) eruptions produce areally extensive (10 4-10 5 km 2) basaltic lava flow fields and silicic ignimbrites that are the main building blocks of LIPs. Available information on the largest eruptive units are primarily from the Columbia River and Deccan provinces for the dimensions of flood basalt eruptions, and the Paraná-Etendeka and Afro-Arabian provinces for the silicic ignimbrite eruptions. In addition, three large-volume (675-2000 km 3) silicic lava flows have also been mapped out in the Proterozoic Gawler Range province (Australia), an interpreted LIP remnant. Magma volumes of > 1000 km 3 have also been emplaced as high-level basaltic and rhyolitic sills in LIPs. The data sets indicate comparable eruption magnitudes between the basaltic and silicic eruptions, but due to considerable volumes residing as co-ignimbrite ash deposits, the current volume constraints for the silicic ignimbrite eruptions may be considerably underestimated. Magma composition thus appears to be no barrier to the volume of magma emitted during an individual eruption. Despite this general similarity in magnitude, flood basaltic and silicic eruptions are very different in terms of eruption style, duration, intensity, vent configuration, and emplacement style. Flood basaltic eruptions are dominantly effusive and Hawaiian-Strombolian in style, with magma discharge rates of ~ 10 6-10 8 kg s -1 and eruption durations estimated at years to tens of years that emplace dominantly compound pahoehoe lava flow fields. Effusive and fissural eruptions have also emplaced some large-volume silicic lavas, but discharge rates are unknown, and may be up to an order of magnitude greater than those of flood basalt lava eruptions for emplacement to be on realistic time scales (< 10 years). Most

  14. Plasma density estimation of a fusion grade ICP source through electrical parameters of the RF generator circuit

    NASA Astrophysics Data System (ADS)

    Bandyopadhyay, M.; Sudhir, Dass; Chakraborty, A.

    2015-03-01

    An inductively coupled plasma (ICP) based negative hydrogen ion source is chosen for ITER neutral beam (NB) systems. To avoid regular maintenance in a radioactive environment with high flux of 14 MeV neutrons and gamma rays, invasive plasma diagnostics like probes are not included in the ITER NB source design. While, optical or microwave based diagnostics which are normally used in other plasma sources, are to be avoided in the case of ITER sources due to the overall system design and interface issues. In such situation, alternative forms of assessment to characterize ion source plasma become a necessity. In the present situation, the beam current through the extraction system in the ion source is the only measurement which indicates plasma condition inside the ion source. However, beam current not only depends on the plasma condition near the extraction region but also on the perveance condition and negative ion stripping. Apart from that, the ICP production region radio frequency (RF) driver region) is placed far (∼30 cm) from the extraction region. Therefore, there are uncertainties involved in linking the beam current with plasma properties inside the RF driver. To maintain the optimum condition for source operation it is necessary to maintain the optimum conditions in the driver. A method of characterization of the plasma density in the driver without using any invasive or non-invasive probes could be a useful tool to achieve that objective. Such a method, which is exclusively for ICP based ion sources, is presented in this paper. In this technique, plasma density inside the RF driver is estimated through the measurements of the electrical parameters in the RF power supply circuit path. Monitoring RF driver plasma through the described route will be useful during the source commissioning phase and also in the beam operation phase.

  15. Fluctuations of electrical conductivity: a new source for astrophysical magnetic fields

    NASA Astrophysics Data System (ADS)

    Gissinger, Christophe; Petrelis, Francois; Alexakis, Alexandros

    2016-04-01

    We consider the generation of magnetic field by the flow of a fluid for which the electrical conductivity is nonuniform. We calculate the properties of this effect both analytically and numerically, and find a new amplification mechanism leading to dynamo action for flows much simpler than those considered so far. In particular, the fluctuations of the electrical conductivity provide a way to bypass anti-dynamo theorems. For astrophysical objects, we show through three-dimensional global numerical simulations that the temperature-driven fluctuations of the electrical conductivity can amplify an otherwise decaying large scale equatorial dipolar field. This effect could play a role for the generation of the unusually tilted magnetic field of the iced giants Neptune and Uranus.

  16. High-latitude field-aligned current sources and induced electric fields

    NASA Technical Reports Server (NTRS)

    Barbosa, D. D.

    1979-01-01

    Using a simple, planar model of the high latitude ionosphere with an enhanced conductivity auroral ring, the electric potential is computed for a pair of field-aligned current sheets inferred from observations. The relationship of various characteristics of the electric potential pattern to features of the field-aligned current distribution are elucidated in the context of a generalized field-aligned current Fourier analysis. On the basis of the analysis and observations to date, it is concluded that boundary layer dynamo action is the prevalent mechanism in the solar wind/magnetosphere/ionosphere interaction.

  17. Equivalent circuit model including magnetic and thermo sources for the thermo-magneto-electric coupling effect in magnetoelectric laminates

    NASA Astrophysics Data System (ADS)

    Cui, Xiao-Le; Zhou, Hao-Miao

    2015-07-01

    The nonlinear thermo-magneto-mechanical magnetostrictive constitutive and the linear thermo-mechanical-electric piezoelectric constitutive are adopted in this paper. The bias magnetic field and ambient temperature are equivalent to a magnetic source and a thermo source, respectively. An equivalent circuit, which contains a magnetic source and a thermo source at the input, for the thermo-magneto-electric coupling effect in magnetoelectric (ME) laminates, is established. The theoretical models of the output voltage and static ME coefficient for ME laminates can be derived from this equivalent circuit model. The predicted static ME coefficient versus temperature curves are in excellent agreement with the experimental data available both qualitatively and quantitatively. It confirms the validity of the proposed model. Then the models are adopted to predict variations in the output voltages and ME coefficients in the laminates under different ambient temperatures, bias magnetic fields, and the volume ratios of magnetostrictive phases. This shows that the output voltage increases with both increasing temperature and increasing volume ratio of magnetostrictive phases; the ME coefficient decreases with increasing temperature; the ME coefficient shows an initial sharp increase and then decreases slowly with the increase in the bias magnetic field, and there is an optimum volume ratio of magnetostrictive phases that maximize the ME coefficient. This paper can not only provide a new idea for the study of the thermo-magneto-electric coupling characteristics of ME laminates, but also provide a theoretical basis for the design and application of ME laminates, operating under different sensors. Project supported by the National Natural Science Foundation of China (Grant Nos. 11172285 and 11472259) and the Natural Science Foundation of Zhejiang Province, China (Grant No. LR13A020002).

  18. 77 FR 26476 - Standards of Performance for Greenhouse Gas Emissions for New Stationary Sources: Electric...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-05-04

    ... published in the Federal Register on April 13, 2012 (77 FR 22392), and is available at: http://www.epa.gov... AGENCY 40 CFR Part 60 Standards of Performance for Greenhouse Gas Emissions for New Stationary Sources... proposed rule, ``Standards of Performance for Greenhouse Gas Emissions for New Stationary Sources:...

  19. On the macroseismic magnitudes of the largest Italian earthquakes

    NASA Astrophysics Data System (ADS)

    Tinti, S.; Vittori, T.; Mulargia, F.

    1987-07-01

    The macroseismic magnitudes MT of the largest Italian earthquakes ( I0 ⩾ VIII, MCS) have been computed by using the intensity magnitude relationships recently assessed by the authors (1986) for the Italian region. The Progetto Finalizzato Geodinamica (PFG) catalog of the Italian earthquakes, covering the period 1000-1980 (Postpischl, 1985) is the source data base and is reproduced in the Appendix: here the estimated values of MT are given side by side with the catalog macroseismic magnitudes MK i.e. the magnitudes computed according to the Karnik laws (Karnik, 1969). The one-sigma errors Δ MT are also given for each earthquake. The basic aim of the paper is to provide a handy and useful tool to researchers involved in seismicity and seismic-risk studies on Italian territory.

  20. Largest-ever Ozone Hole over Antarctica

    NASA Technical Reports Server (NTRS)

    2002-01-01

    A NASA instrument has detected an Antarctic ozone 'hole' (what scientists call an 'ozone depletion area') that is three times larger than the entire land mass of the United States-the largest such area ever observed. The 'hole' expanded to a record size of approximately 11 million square miles (28.3 million square kilometers) on Sept. 3, 2000. The previous record was approximately 10.5 million square miles (27.2 million square km) on Sept. 19, 1998. The ozone hole's size currently has stabilized, but the low levels in its interior continue to fall. The lowest readings in the ozone hole are typically observed in late September or early October each year. 'These observations reinforce concerns about the frailty of Earth's ozone layer. Although production of ozone-destroying gases has been curtailed under international agreements, concentrations of the gases in the stratosphere are only now reaching their peak. Due to their long persistence in the atmosphere, it will be many decades before the ozone hole is no longer an annual occurrence,' said Dr. Michael J. Kurylo, manager of the Upper Atmosphere Research Program, NASA Headquarters, Washington, DC. Ozone molecules, made up of three atoms of oxygen, comprise a thin layer of the atmosphere that absorbs harmful ultraviolet radiation from the Sun. Most atmospheric ozone is found between approximately six miles (9.5 km) and 18 miles (29 km) above the Earth's surface. Scientists continuing to investigate this enormous hole are somewhat surprised by its size. The reasons behind the dimensions involve both early-spring conditions, and an extremely intense Antarctic vortex. The Antarctic vortex is an upper-altitude stratospheric air current that sweeps around the Antarctic continent, confining the Antarctic ozone hole. 'Variations in the size of the ozone hole and of ozone depletion accompanying it from one year to the next are not unexpected,' said Dr. Jack Kaye, Office of Earth Sciences Research Director, NASA Headquarters

  1. Four corners: The largest US methane anomaly viewed from space

    NASA Astrophysics Data System (ADS)

    Kort, Eric A.; Frankenberg, Christian; Costigan, Keeley R.; Lindenmaier, Rodica; Dubey, Manvendra K.; Wunch, Debra

    2014-10-01

    Methane (CH4) is a potent greenhouse gas and ozone precursor. Quantifying methane emissions is critical for projecting and mitigating changes to climate and air quality. Here we present CH4 observations made from space combined with Earth-based remote sensing column measurements. Results indicate the largest anomalous CH4 levels viewable from space over the conterminous U.S. are located at the Four Corners region in the Southwest U.S. Emissions exceeding inventory estimates, totaling 0.59 Tg CH4/yr [0.50-0.67; 2σ], are necessary to bring high-resolution simulations and observations into agreement. This underestimated source approaches 10% of the EPA estimate of total U.S. CH4 emissions from natural gas. The persistence of this CH4 signal from 2003 onward indicates that the source is likely from established gas, coal, and coalbed methane mining and processing. This work demonstrates that space-based observations can identify anomalous CH4 emission source regions and quantify their emissions with the use of a transport model.

  2. Modeling of surface-dominated plasmas: From electric thruster to negative ion source

    SciTech Connect

    Taccogna, F.; Schneider, R.; Longo, S.; Capitelli, M.

    2008-02-15

    This contribution shows two important applications of the particle-in-cell/monte Carlo technique on ion sources: modeling of the Hall thruster SPT-100 for space propulsion and of the rf negative ion source for ITER neutral beam injection. In the first case translational degrees of freedom are involved, while in the second case inner degrees of freedom (vibrational levels) are excited. Computational results show how in both cases, plasma-wall and gas-wall interactions play a dominant role. These are secondary electron emission from the lateral ceramic wall of SPT-100 and electron capture from caesiated surfaces by positive ions and atoms in the rf negative ion source.

  3. Semiclassical scattering of an electric dipole source inside a spherical particle.

    PubMed

    Lock, J A

    2001-12-01

    Semiclassical scattering phenomena appearing in the far-zone scattered intensity of a point source of electromagnetic radiation inside a spherical particle are examined in the context of both ray theory and wave theory, and the evolution of the phenomena is studied as a function of source position. A number of semiclassical effects that do not occur for plane-wave scattering by the sphere appear prominently for scattering by an interior source. These include a series of scattering resonances and a new family of rainbows in regions of otherwise total internal reflection. Diffractive effects accompanying the semiclassical phenomena are also examined. PMID:11760206

  4. Real-Time Localization of Moving Dipole Sources for Tracking Multiple Free-Swimming Weakly Electric Fish

    PubMed Central

    Jun, James Jaeyoon; Longtin, André; Maler, Leonard

    2013-01-01

    In order to survive, animals must quickly and accurately locate prey, predators, and conspecifics using the signals they generate. The signal source location can be estimated using multiple detectors and the inverse relationship between the received signal intensity (RSI) and the distance, but difficulty of the source localization increases if there is an additional dependence on the orientation of a signal source. In such cases, the signal source could be approximated as an ideal dipole for simplification. Based on a theoretical model, the RSI can be directly predicted from a known dipole location; but estimating a dipole location from RSIs has no direct analytical solution. Here, we propose an efficient solution to the dipole localization problem by using a lookup table (LUT) to store RSIs predicted by our theoretically derived dipole model at many possible dipole positions and orientations. For a given set of RSIs measured at multiple detectors, our algorithm found a dipole location having the closest matching normalized RSIs from the LUT, and further refined the location at higher resolution. Studying the natural behavior of weakly electric fish (WEF) requires efficiently computing their location and the temporal pattern of their electric signals over extended periods. Our dipole localization method was successfully applied to track single or multiple freely swimming WEF in shallow water in real-time, as each fish could be closely approximated by an ideal current dipole in two dimensions. Our optimized search algorithm found the animal’s positions, orientations, and tail-bending angles quickly and accurately under various conditions, without the need for calibrating individual-specific parameters. Our dipole localization method is directly applicable to studying the role of active sensing during spatial navigation, or social interactions between multiple WEF. Furthermore, our method could be extended to other application areas involving dipole source

  5. A Time-Dependent Fluid Model for the Study of the Electrical Properties of GEC Sources

    NASA Astrophysics Data System (ADS)

    Mallios, S. A.; Jansky, J.; Pasko, V. P.

    2014-12-01

    The Global Electric Circuit (GEC) is a circuit that is formed between the Earth's surface, which is a good conductor of electricity, and the ionosphere, a weekly-ionized plasma at around 80 km altitude [e.g., Rycroft et al., Space Sci. Rev., 137(1-4), pp. 83-105, 2008]. It is accepted that thunderstorms are the main generators in the GEC [e.g., Williams, Atmospheric Research, 91, 140, 2009; Mareev, Physics Uspekhi, 53, 504, 2010]. In the current work, we developed a two-dimensional cylindrical time-dependent fluid model that takes into account several atmospheric processes, such as the ionization due to the galactic cosmic rays radiation, the ion-ion recombination, and the attachment of ions to cloud particles. The developed model is able to calculate self consistently the time dynamics of the conductivity, according to the time dynamics of the cloud particle charge density during the formation of thunderstorms/electrified clouds. We calculate the time dynamics of the electric field distribution, the charge density distribution and the current density distribution, and we compare them with the results obtained by a model that assumes constant conductivity distribution over time.

  6. Electricity by intermittent sources: An analysis based on the German situation 2012

    NASA Astrophysics Data System (ADS)

    Wagner, Friedrich

    2014-02-01

    The 2012 data of the German load, the on- and offshore and the photo-voltaic energy production are used and scaled to the limit of supplying the annual demand (100% case). The reference mix of the renewable energy (RE) forms is selected such that the remaining back-up energy is minimised. For the 100% case, the RE power installation has to be about 3 times the present peak load. The back-up system can be reduced by 12% in this case. The surplus energy corresponds to 26% of the demand. The back-up system and more so the grid must be able to cope with large power excursions. All components of the electricity supply system operate at low capacity factors. Large-scale storage can hardly be motivated by the effort to further reduce CO2 emission. Demand-side management will intensify the present periods of high economic activities. Its rigorous implementation will expand the economic activities into the weekends. On the basis of a simple criterion, the increase of periods with negative electricity prices in Germany is assessed. It will be difficult with RE to meet the low CO2 emission factors which characterise those European Countries which produce electricity mostly by nuclear and hydro power.

  7. First Light for World's Largest 'Thermometer Camera'

    NASA Astrophysics Data System (ADS)

    2007-08-01

    LABOCA in Service at APEX The world's largest bolometer camera for submillimetre astronomy is now in service at the 12-m APEX telescope, located on the 5100m high Chajnantor plateau in the Chilean Andes. LABOCA was specifically designed for the study of extremely cold astronomical objects and, with its large field of view and very high sensitivity, will open new vistas in our knowledge of how stars form and how the first galaxies emerged from the Big Bang. ESO PR Photo 35a/07 ESO PR Photo 35a/07 LABOCA on APEX "A large fraction of all the gas in the Universe has extremely cold temperatures of around minus 250 degrees Celsius, a mere 20 degrees above absolute zero," says Karl Menten, director at the Max Planck Institute for Radioastronomy (MPIfR) in Bonn, Germany, that built LABOCA. "Studying these cold clouds requires looking at the light they radiate in the submillimetre range, with very sophisticated detectors." Astronomers use bolometers for this task, which are, in essence, thermometers. They detect incoming radiation by registering the resulting rise in temperature. More specifically, a bolometer detector consists of an extremely thin foil that absorbs the incoming light. Any change of the radiation's intensity results in a slight change in temperature of the foil, which can then be registered by sensitive electronic thermometers. To be able to measure such minute temperature fluctuations requires the bolometers to be cooled down to less than 0.3 degrees above absolute zero, that is below minus 272.85 degrees Celsius. "Cooling to such low temperatures requires using liquid helium, which is no simple feat for an observatory located at 5100m altitude," says Carlos De Breuck, the APEX instrument scientist at ESO. Nor is it simple to measure the weak temperature radiation of astronomical objects. Millimetre and submillimetre radiation opens a window into the enigmatic cold Universe, but the signals from space are heavily absorbed by water vapour in the Earth

  8. Note: An advanced in situ diagnostic system for characterization of electric propulsion thrusters and ion beam sources.

    PubMed

    Bundesmann, C; Tartz, M; Scholze, F; Leiter, H J; Scortecci, F; Gnizdor, R Y; Neumann, H

    2010-04-01

    We present an advanced diagnostic system for in situ characterization of electric propulsion thrusters and ion beam sources. The system uses a high-precision five-axis positioning system with a modular setup and the following diagnostic tools: a telemicroscopy head for optical imaging, a triangular laser head for surface profile scanning, a pyrometer for temperature scanning, a Faraday probe for current density mapping, and an energy-selective mass spectrometer for beam characterization (energy and mass distribution, composition). The capabilities of our diagnostic system are demonstrated with a Hall effect thruster SPT-100D EM1. PMID:20441379

  9. A new approach for optimal VAR sources planning in large scale electric power systems

    SciTech Connect

    Yingtung Hsiao; Chunchang Liu; Yuanlin Chen . Dept. of Electrical Engineering); Hsiodong Chiang )

    1993-08-01

    This paper presents a new approach for contingency-constrained optimal reactive volt amper (VAR) sources planning in large-scale power systems. Features distinguishing the proposed approach from many of the existing methods include that it allows a more realistic problem formulation, and that it can find the (global) optimal solution. The new problem formulation takes into consideration practical aspects of VAR sources; the load constraints and operational constraints at different load levels. This solution methodology based on simulated annealing determines (1) the location to install VAR sources; (2) the types and sizes of VAR sources to be installed; and (3) the settings of VAR sources at different loading conditions. In order to speed up the solution algorithm, this paper makes a slight modification of the fast decoupled load flow and incorporates it into the solution algorithm. This method is suitable for large-scale power systems and has been tested on several power systems with promising results. Simulation results on the IEEE 30 buses system and the Tai-power 358 buses system are presented.

  10. Modeling of surface-dominated plasmas: from electric thruster to negative ion source.

    PubMed

    Taccogna, F; Schneider, R; Longo, S; Capitelli, M

    2008-02-01

    This contribution shows two important applications of the particle-in-cell/monte Carlo technique on ion sources: modeling of the Hall thruster SPT-100 for space propulsion and of the rf negative ion source for ITER neutral beam injection. In the first case translational degrees of freedom are involved, while in the second case inner degrees of freedom (vibrational levels) are excited. Computational results show how in both cases, plasma-wall and gas-wall interactions play a dominant role. These are secondary electron emission from the lateral ceramic wall of SPT-100 and electron capture from caesiated surfaces by positive ions and atoms in the rf negative ion source. PMID:18315218

  11. Global assessment of nutrient loads to the world's largest lakes

    NASA Astrophysics Data System (ADS)

    Fink, Gabriel; Reder, Klara; Malsy, Marcus; Eisner, Stephanie; Flörke, Martina

    2015-04-01

    Lakes are essential resources of drinking water for a large part of mankind. Even so, most of the industrial and domestic waste water is discharged - often untreated - into rivers and streams that are finally the tributaries of these important freshwater bodies. Additionally, diffuse nutrient sources such as fertilizer and atmospheric deposition exacerbate existing algal blooms and low oxygen concentrations in rivers, lakes, and reservoirs. In this tense atmosphere of competing water uses, it is necessary to analyze all sources of pollution as well as their total contributions in order to protect these water bodies against deterioration. Finally, this is a general and urgently needed basis for developing recommendations for involved stakeholders and decision makers. Therefore, the project eartH2Observe, initiated and financed by the European Commission, creates the necessary and underlying quantitative and qualitative hydrological and water use data. In this context, information for global as well as for regional water resource assessments is being prepared based on new earth observations and an ensemble of global hydrological models. As a member of this ensemble, WaterGAP3 provides global estimates of lake water quality relevant parameters on a 5 arc minutes grid, namely total phosphorus and total nitrogen. These nutrient loads to lakes from different sources such as industrial fertilizer, organic fertilizer, domestic loads, atmospheric deposition, and urban surface runoff are estimated for the period 1990 to 2010 in a monthly time step. Whereas nutrient loads and their changes into numerous lakes worldwide are calculated, a special focus is set on nutrient loads into the large and shallow Lake Peipus, which is located between Estonia and Russia and subject to blooms of harmful cyanobacteria. We present estimates, trends, as well as sources of present nutrient loads (TN and TP) to the world's largest lakes with detailed insights to the Lake Peipus situation

  12. Electrical conductivity of the lunar interior - Theory, error sources, and estimates

    NASA Technical Reports Server (NTRS)

    Goldstein, B. E.

    1979-01-01

    Estimates of the electrical conductivity of the lunar interior were previously obtained by comparison of magnetometer data at the lunar surface and in near lunar space. In studies based on solar wind observations, IR was assumed that fields induced in the lunar interior by time-varying external fields are confined by the solar wind within the lunar interior on the dayside and within a cylindrical plasma cavity on the nightside. In the present paper, the induced fields are calculated for a more realistic conical plasma cavity geometry.

  13. Heterogeneous integration of electrically driven microdisk based laser sources for optical interconnects and photonic ICs.

    PubMed

    Rojo Romeo, P; Van Campenhout, J; Regreny, P; Kazmierczak, A; Seassal, C; Letartre, X; Hollinger, G; Van Thourhout, D; Baets, R; Fedeli, J M; Di Cioccio, L

    2006-05-01

    A new approach for an electrically driven microlaser based on a microdisk transferred onto Silicon is proposed. The structure is based on a quaternary InGaAsP p-i-n junction including three InAsP quantum wells, on a thin membrane transferred onto silicon by molecular bonding. A p++/n++ tunnel junction is used as the p-type contact. The technological procedure is described and first experimental results show a laser emission in pulsed regime at room temperature, with a threshold current near 1.5 mA. PMID:19516533

  14. Photon pair sources in AlGaAs: from electrical injection to quantum state engineering

    NASA Astrophysics Data System (ADS)

    Autebert, C.; Boucher, G.; Boitier, F.; Eckstein, A.; Favero, I.; Leo, G.; Ducci, S.

    2015-11-01

    Integrated quantum photonics is a very active field of quantum information, communication, and processing. One of the main challenges to achieve massively parallel systems for complex operations is the generation, manipulation, and detection of many qubits within the same chip. Here, we present our last achievements on AlGaAs quantum photonic devices emitting nonclassical states of light at room temperature by spontaneous parametric down conversion (SPDC). The choice of this platform combines the advantages of a mature fabrication technology, a high nonlinear coefficient, a SPDC wavelength in the C-telecom band and the possibility of electrical injection.

  15. French wind generator systems. [as auxiliary power sources for electrical networks

    NASA Technical Reports Server (NTRS)

    Noel, J. M.

    1973-01-01

    The experimental design of a wind driven generator with a rated power of 800 kilovolt amperes and capable of being connected to the main electrical network is reported. The rotor is a three bladed propeller; each blade is twisted but the fixed pitch is adjustable. The asynchronous 800-kilovolt ampere generator is driven by the propeller through a gearbox. A dissipating resistor regulates the machine under no-load conditions. The first propeller on the machine lasted 18 months; replacement of the rigid propeller with a flexible structure resulted in breakdown due to flutter effects.

  16. Contribution of electric energy to the process of elimination of low emission sources in Cracow

    SciTech Connect

    Lach, J.; Mejer, T.; Wybranski, A.

    1995-12-31

    At present energy supply belongs to the most important global problems. A significant part of energy is consumed for residential heating purposes. Depending on climatic conditions, fuel distribution and the level of technological development, the contribution of these purposes ranges between ca. 50% (Poland) and ca. 12% (Spain). The power engineering structure in Poland is based almost exclusively upon solid fuels, i.e. hard and brown coal. Chemical compounds (carbon dioxide, sulfur dioxide and nitrogen oxides) produced in combustion process influence negatively the natural environment. The contribution of residential heating in this negative effect is rather significant. Because of the fact, that the resources of fossil fuels (the most important source of energy at present) are limited and their influence on natural environment is negative, efforts are made to find out more effective ways of energy consumption and to reduce the pollutant emission from heating sources. This problem is a topical issue in Cracow, especially during the heating season because the coal-fired stoves situated in the central part of the town remain the most important source of pollutant emission. These sources cause serious menace to the health of inhabitants; furthermore the pollutants destroy Cracow monuments entered in the UNESCO world list of human heritage.

  17. Case histories of electrical resistivity and controlled-source magnetotelluric surveys for the site investigation of tunnel construction

    SciTech Connect

    Kwon, H.S.; Song, Y.; Yi, M.J.; Chung, H.J.; Kim, K.S.

    2006-12-15

    In tunnel construction, the information regarding rock mass quality and the distribution of weak zones is crucial for economical tunnel design and to ensure safety. Usually, the rock mass grade is estimated by observing recovered cores obtained by drilling or by physical parameters calculated in a laboratory using core samples. However, the high drilling cost limits the number of boreholes; furthermore, rough terrains can reduce the access of drilling machines to the survey sites. In such situations, surface geophysical methods such as electrical resistivity or controlled-source magnetotelluric (CSMT) can provide a rough estimate of the rock mass condition over the planned tunnel route. These methods can also map weak zones (faults, fractures, coal bearing zones, and cavities), which are characterized by a lower resistivity than the surrounding fresh rock mass. We present two successful applications of the electrical resistivity and CSMT methods to the site investigation of tunnel construction over a rough terrain. The first example demonstrates that the boundary of the bedrock and weak zones related to the distribution of coaly shale and coal seams were estimated to extend beyond a few hundred meters below the rough surface. The second example shows that the developing direction and depth of cavities, which are mainly related to the weak zones in limestone, were successfully interpreted by a three-dimensional (3-D) electrical resistivity survey with the aid of borehole test results.

  18. High yield and ultrafast sources of electrically triggered entangled-photon pairs based on strain-tunable quantum dots

    NASA Astrophysics Data System (ADS)

    Zhang, Jiaxiang; Wildmann, Johannes S.; Ding, Fei; Trotta, Rinaldo; Huo, Yongheng; Zallo, Eugenio; Huber, Daniel; Rastelli, Armando; Schmidt, Oliver G.

    2015-12-01

    Triggered sources of entangled photon pairs are key components in most quantum communication protocols. For practical quantum applications, electrical triggering would allow the realization of compact and deterministic sources of entangled photons. Entangled-light-emitting-diodes based on semiconductor quantum dots are among the most promising sources that can potentially address this task. However, entangled-light-emitting-diodes are plagued by a source of randomness, which results in a very low probability of finding quantum dots with sufficiently small fine structure splitting for entangled-photon generation (~10-2). Here we introduce strain-tunable entangled-light-emitting-diodes that exploit piezoelectric-induced strains to tune quantum dots for entangled-photon generation. We demonstrate that up to 30% of the quantum dots in strain-tunable entangled-light-emitting-diodes emit polarization-entangled photons. An entanglement fidelity as high as 0.83 is achieved with fast temporal post selection. Driven at high speed, that is 400 MHz, strain-tunable entangled-light-emitting-diodes emerge as promising devices for high data-rate quantum applications.

  19. High yield and ultrafast sources of electrically triggered entangled-photon pairs based on strain-tunable quantum dots.

    PubMed

    Zhang, Jiaxiang; Wildmann, Johannes S; Ding, Fei; Trotta, Rinaldo; Huo, Yongheng; Zallo, Eugenio; Huber, Daniel; Rastelli, Armando; Schmidt, Oliver G

    2015-01-01

    Triggered sources of entangled photon pairs are key components in most quantum communication protocols. For practical quantum applications, electrical triggering would allow the realization of compact and deterministic sources of entangled photons. Entangled-light-emitting-diodes based on semiconductor quantum dots are among the most promising sources that can potentially address this task. However, entangled-light-emitting-diodes are plagued by a source of randomness, which results in a very low probability of finding quantum dots with sufficiently small fine structure splitting for entangled-photon generation (∼10(-2)). Here we introduce strain-tunable entangled-light-emitting-diodes that exploit piezoelectric-induced strains to tune quantum dots for entangled-photon generation. We demonstrate that up to 30% of the quantum dots in strain-tunable entangled-light-emitting-diodes emit polarization-entangled photons. An entanglement fidelity as high as 0.83 is achieved with fast temporal post selection. Driven at high speed, that is 400 MHz, strain-tunable entangled-light-emitting-diodes emerge as promising devices for high data-rate quantum applications. PMID:26621073

  20. Property-close source separation of hazardous waste and waste electrical and electronic equipment - A Swedish case study

    SciTech Connect

    Bernstad, Anna; Cour Jansen, Jes la; Aspegren, Henrik

    2011-03-15

    Through an agreement with EEE producers, Swedish municipalities are responsible for collection of hazardous waste and waste electrical and electronic equipment (WEEE). In most Swedish municipalities, collection of these waste fractions is concentrated to waste recycling centres where households can source-separate and deposit hazardous waste and WEEE free of charge. However, the centres are often located on the outskirts of city centres and cars are needed in order to use the facilities in most cases. A full-scale experiment was performed in a residential area in southern Sweden to evaluate effects of a system for property-close source separation of hazardous waste and WEEE. After the system was introduced, results show a clear reduction in the amount of hazardous waste and WEEE disposed of incorrectly amongst residual waste or dry recyclables. The systems resulted in a source separation ratio of 70 wt% for hazardous waste and 76 wt% in the case of WEEE. Results show that households in the study area were willing to increase source separation of hazardous waste and WEEE when accessibility was improved and that this and similar collection systems can play an important role in building up increasingly sustainable solid waste management systems.

  1. High yield and ultrafast sources of electrically triggered entangled-photon pairs based on strain-tunable quantum dots

    PubMed Central

    Zhang, Jiaxiang; Wildmann, Johannes S.; Ding, Fei; Trotta, Rinaldo; Huo, Yongheng; Zallo, Eugenio; Huber, Daniel; Rastelli, Armando; Schmidt, Oliver G.

    2015-01-01

    Triggered sources of entangled photon pairs are key components in most quantum communication protocols. For practical quantum applications, electrical triggering would allow the realization of compact and deterministic sources of entangled photons. Entangled-light-emitting-diodes based on semiconductor quantum dots are among the most promising sources that can potentially address this task. However, entangled-light-emitting-diodes are plagued by a source of randomness, which results in a very low probability of finding quantum dots with sufficiently small fine structure splitting for entangled-photon generation (∼10−2). Here we introduce strain-tunable entangled-light-emitting-diodes that exploit piezoelectric-induced strains to tune quantum dots for entangled-photon generation. We demonstrate that up to 30% of the quantum dots in strain-tunable entangled-light-emitting-diodes emit polarization-entangled photons. An entanglement fidelity as high as 0.83 is achieved with fast temporal post selection. Driven at high speed, that is 400 MHz, strain-tunable entangled-light-emitting-diodes emerge as promising devices for high data-rate quantum applications. PMID:26621073

  2. Ultrafine particles from electric appliances and cooking pans: experiments suggesting desorption/nucleation of sorbed organics as the primary source.

    PubMed

    Wallace, L A; Ott, W R; Weschler, C J

    2015-10-01

    Ultrafine particles are observed when metal surfaces, such as heating elements in electric appliances, or even empty cooking pans, are heated. The source of the particles has not been identified. We present evidence that particles >10 nm are not emitted directly from the heating elements or the metal surfaces. Using repeated heating of an electric burner, several types of cooking pans, and a steam iron, the increase in the number of particles (>10 nm) can be reduced to 0. After the devices are exposed to indoor air for several hours or days, subsequent heating results in renewed particle production, suggesting that organic matter has sorbed on their surfaces. Also, after a pan has been heated to the point that no increase in particles is observed, washing with detergent results in copious production of particles the next time the pan is heated. These observations suggest that detergent residue and organics sorbed from indoor air are the sources of the particles. We hypothesize that organic compounds are thermally desorbed from the hot surface as gaseous molecules; as they diffuse from the hot air near the pan into cooler air, selected compounds exceed their saturation concentration and nucleation occurs. PMID:25250820

  3. Theoretical and measured electric field distributions within an annular phased array: consideration of source antennas.

    PubMed

    Zhang, Y; Joines, W T; Jirtle, R L; Samulski, T V

    1993-08-01

    The magnitude of E-field patterns generated by an annular array prototype device has been calculated and measured. Two models were used to describe the radiating sources: a simple linear dipole and a stripline antenna model. The stripline model includes detailed geometry of the actual antennas used in the prototype and an estimate of the antenna current based on microstrip transmission line theory. This more detailed model yields better agreement with the measured field patterns, reducing the rms discrepancy by a factor of about 6 (from approximately 23 to 4%) in the central region of interest where the SEM is within 25% of the maximum. We conclude that accurate modeling of source current distributions is important for determining SEM distributions associated with such heating devices. PMID:8258444

  4. Electrical transmission lines in Montana: Mitigation of impacts to soil and biological sources

    SciTech Connect

    McCollough, S.A.; Ring, T.W.

    1990-12-31

    In Montana, the routing and construction of large electrical transmission lines are regulated by the Montana Major Facility Siting Act. Under this act, impacts to resources are minimized through avoidance by routing, where possible, and by mitigating remaining impacts. Land disturbed by the construction of transmission lines considered in this paper ranges from 1681 acres for a 500-kV line across 156 miles of mountainous terrain to 11 acres for a 100-kV line across 27 miles of nearly level terrain. Line access accounts for most of the disturbance, especially when graded roads are built in mountainous terrain. Land disturbed by transmission line construction is susceptible to soil erosion and weed infestation. These problems are addressed through revegetation, erosion control, and herbicide application. Transmission lines can displace wildlife from critical habitats by disruptive construction activities or by improving human access to previously secure range. Wildlife impacts can be reduced by restricting construction periods and gating roads.

  5. The magmatic source of the Tristan da Cunha hotspot: Implication from electrical conductivity

    NASA Astrophysics Data System (ADS)

    Chen, Jin; Baba, Kiyoshi; Jegen, Marion; Utada, Hisashi; Geissler, Wolfram; Jokat, Wilfried

    2016-04-01

    Tristan da Cunha Island is one of the classical hot spots in the Atlantic Ocean, situated at the western end of the aseismic Walvis Ridge which forms a connection to the Cretaceous Etendeka flood basalt province in northwestern Namibia. The discussion about its source (in shallow asthenosphere or deeper mantle) have not reached consensus yet because of lack of the geophysical observations in the area. A marine magnetotelluric (MT) experiment was conducted together with seismological observations in the area in 2012-2013 through a German-Japanese collaboration with the goal to constrain the physical state of the mantle beneath the area. A total of 26 MT seafloor stations were deployed around the Tristan da Cunha Islands and available data were retrieved and processed from 24 stations. We applied iterative topographic effect correction and one-dimensional (1-D) conductivity structure inversion to the data. Then, three-dimensional (3-D) inversion analysis incorporating the topographic effect was carried out, using the 1-D model as the initial model. The local small-scale topography and the far continental coast effects are incorporated as the distortion term in the 3-D inversion. The preliminary result of our analysis shows no evidence of a significant conductive anomaly arising from the mantle transition zone, suggesting that the current magmatic source (major place of melting) of the hotspot activity is in the shallow upper mantle. This is in contrast to results from geochemical analysis, in which samples along the Tristan track exhibit an ocean-island-basalt-type incompatible element pattern pointing to a deep mantle source of the melt. Our findings therefore might indicate that the deep mantle up-welling underneath Tristan da Cunha Islands may be almost dead. A conductive anomaly at approx. 100 km depth in our derived conductivity model to the southwest of Tristan da Cunha Islands suggests an interaction between the mid-ocean ridge and/or up-welling further south

  6. A source of electrical energy using an air-aluminum element (AAE)

    SciTech Connect

    Anisin, A.V.; Borisenok, V.A.; Potemkin, G.A.

    1996-04-01

    An air-aluminium element (AAE) is a chemical current source (CCS) with an aluminium anode and an oxygen gas-diffusion cathode. An AAE may be relegated to intermediate types of CCS, occupying a position between primary and fuel cells. The consumable material is aluminium, and the oxidizer is oxygen in the air coming from the external environment. The electrolyte is an aqueous solution of sodium chloride. Sea water may be used in this capacity. The end product of AAE operation is aluminium hydroxide, which can be regenerated into the initial anode aluminium, and is a non-toxic product.

  7. Plug-in hybrid electric vehicles as a source of distributed frequency regulation

    NASA Astrophysics Data System (ADS)

    Mullen, Sara Kathryn

    The movement to transform the North American power grid into a smart grid may be accomplished by expanding integrated sensing, communications, and control technologies to include every part of the grid to the point of end-use. Plug-in hybrid electric vehicles (PHEV) provide an opportunity for small-scale distributed storage while they are plugged-in. With large numbers of PHEV and the communications and sensing associated with the smart grid, PHEV could provide ancillary services for the grid. Frequency regulation is an ideal service for PHEV because the duration of supply is short (order of minutes) and it is the highest priced ancillary service on the market offering greater financial returns for vehicle owners. Using Simulink a power system simulator modeling the IEEE 14 Bus System was combined with a model of PHEV charging and the controllers which facilitate vehicle-to-grid (V2G) regulation supply. The system includes a V2G controller for each vehicle which makes regulation supply decisions based on battery state, user preferences, and the recommended level of supply. A PHEV coordinator controller located higher in the system has access to reliable frequency measurements and can determine a suitable local automatic generation control (AGC) raise/lower signal for participating vehicles. A first step implementation of the V2G supply system where battery charging is modulated to provide regulation was developed. The system was simulated following a step change in loading using three scenarios: (1) Central generating units provide frequency regulation, (2) PHEV contribute to primary regulation analogous to generator speed governor control, and (3) PHEV contribute to primary and secondary regulation using an additional integral term in the PHEV control signal. In both cases the additional regulation provided by PHEV reduced the area control error (ACE) compared to the base case. Unique contributions resulting from this work include: (1) Studied PHEV energy systems

  8. Mapping of electrical potential distribution with charged particle beams. [using an X-ray source

    NASA Technical Reports Server (NTRS)

    Robinson, J. W.

    1979-01-01

    Potentials were measured using a beam of soft X-rays in air at 2 x 10 to the -5 power Torr. Ions were detected by a continuous-dynode electron multiplier after they passed through a retarding field. Ultimate resolution depends upon the diameter of the X-ray beam which was 3 mm. When the fields in the region of interest were such to disperse the ions, only a small fraction were detected and the method of measurement was not very reliable. Yet reasonable data could be collected if the ions traveled in parallel paths toward the detector. Development should concentrate on increasing the aperture of the detector from the pinhole which was used to something measured in centimeters. Also increasing the strength of the source would provide a stronger signal and more reliable data. Measurements were made at an estimated ion current to 10 to the -15 power A from a 10 cm length of the X-ray beam, this current being several orders of magnitude below what would have a perturbing effect on the region to be measured. Consequently, the source strength can be increased and prospects for this method of measurement are good.

  9. Lithium polymer batteries and proton exchange membrane fuel cells as energy sources in hydrogen electric vehicles

    NASA Astrophysics Data System (ADS)

    Corbo, P.; Migliardini, F.; Veneri, O.

    This paper deals with the application of lithium ion polymer batteries as electric energy storage systems for hydrogen fuel cell power trains. The experimental study was firstly effected in steady state conditions, to evidence the basic features of these systems in view of their application in the automotive field, in particular charge-discharge experiments were carried at different rates (varying the current between 8 and 100 A). A comparison with conventional lead acid batteries evidenced the superior features of lithium systems in terms of both higher discharge rate capability and minor resistance in charge mode. Dynamic experiments were carried out on the overall power train equipped with PEM fuel cell stack (2 kW) and lithium batteries (47.5 V, 40 Ah) on the European R47 driving cycle. The usage of lithium ion polymer batteries permitted to follow the high dynamic requirement of this cycle in hard hybrid configuration, with a hydrogen consumption reduction of about 6% with respect to the same power train equipped with lead acid batteries.

  10. Solar-assisted electric clothes dryer using a home attic as a heat source

    SciTech Connect

    Stana, J. M.

    1983-01-01

    This study was undertaken to determine the suitability of using a southeastern home attic as a means of reducing the energy consumption of an electric clothes dryer. An inexpensive duct (duplicable for $25) was constructed to collect hot attic air from the peak of a south facing roof and introduce it into the dryer inlet. Instrumentation was added to measure inlet temperatures and operating time/energy consumption of the dryer. Standardized test loads, in addition to normal laundry, were observed over the period of one year. The heat-on time of the dryer tested was shown to be reduced .16 to .35 minutes per /sup 0/C rise in inlet temperature. Inlet temperatures produced by the attic duct peaked at 56/sup 0/C(133/sup 9/F) in May/June and 40/sup 0/C(104/sup 0/F) in February. Based on peak temperatures available between 2 and 4 pm each month, a potential 20% yearly average savings could be realized. Economic viability of the system, dependant primarily on dryer usage, can be computed using a formula derived from the test results and included in the report.

  11. The magnetospheric disturbance ring current as a source for probing the deep earth electrical conductivity

    USGS Publications Warehouse

    Campbell, W.H.

    1990-01-01

    Two current rings have been observed in the equatorial plane of the earth at times of high geomagnetic activity. An eastward current exists between about 2 and 3.5 earth radii (Re) distant, and a larger, more variable companion current exists between about 4 and 9 Re. These current regions are loaded during geomagnetic substorms. They decay, almost exponentially, after the cessation of the particle influx that attends the solar wind disturbance. This review focuses upon characteristics needed for intelligent use of the ring current as a source for induction probing of the earth's mantle. Considerable difficulties are found with the assumption that Dst is a ring-current index. ?? 1990 Birkha??user Verlag.

  12. Electric Potential Near The Extraction Region In Negative Ion Sources With Surface Produced Negative Ions

    SciTech Connect

    Fukano, A.; Hatayama, A.

    2011-09-26

    The potential distribution near the extraction region in negative ion sources for the plasma with the surface produced negative ions is studied analytically. The potential is derived analytically by using a plasma-sheath equation, where negative ions produced on the Plasma Grid (PG) surface are considered in addition to positive ions and electrons. A negative potential peak is formed in the sheath region near the PG surface for the case of strong surface production of negative ions or for low energy negative ions. Negative ions are reflected by the negative potential peak near the PG and returned to the PG surface. This reflection mechanism by the negative potential peak possibly becomes a factor in negative ion extraction. It is also indicated that the potential difference between the plasma region and the wall decreases by the surface produced negative ions. This also has the possibility to contribute to the negative ion extraction.

  13. Largest US oil and gas fields, August 1993

    SciTech Connect

    Not Available

    1993-08-06

    The Largest US Oil and Gas Fields is a technical report and part of an Energy Information Administration (EIA) series presenting distributions of US crude oil and natural gas resources, developed using field-level data collected by EIA`s annual survey of oil and gas proved reserves. The series` objective is to provide useful information beyond that routinely presented in the EIA annual report on crude oil and natural gas reserves. These special reports also will provide oil and gas resource analysts with a fuller understanding of the nature of US crude oil and natural gas occurrence, both at the macro level and with respect to the specific subjects addressed. The series` approach is to integrate EIA`s crude oil and natural gas survey data with related data obtained from other authoritative sources, and then to present illustrations and analyses of interest to a broad spectrum of energy information users ranging from the general public to oil and gas industry personnel.

  14. Electrical Generation.

    ERIC Educational Resources Information Center

    Science and Children, 1990

    1990-01-01

    Described are two activities designed to help children investigate electrical charges, electric meters, and electromagnets. Included are background information, a list of materials, procedures, and follow-up questions. Sources of additional information are cited. (CW)

  15. Electrically powered hand tool

    DOEpatents

    Myers, Kurt S.; Reed, Teddy R.

    2007-01-16

    An electrically powered hand tool is described and which includes a three phase electrical motor having a plurality of poles; an electrical motor drive electrically coupled with the three phase electrical motor; and a source of electrical power which is converted to greater than about 208 volts three-phase and which is electrically coupled with the electrical motor drive.

  16. The Multivariate Largest Lyapunov Exponent as an Age-Related Metric of Quiet Standing Balance

    PubMed Central

    Liu, Kun; Wang, Hongrui; Xiao, Jinzhuang

    2015-01-01

    The largest Lyapunov exponent has been researched as a metric of the balance ability during human quiet standing. However, the sensitivity and accuracy of this measurement method are not good enough for clinical use. The present research proposes a metric of the human body's standing balance ability based on the multivariate largest Lyapunov exponent which can quantify the human standing balance. The dynamic multivariate time series of ankle, knee, and hip were measured by multiple electrical goniometers. Thirty-six normal people of different ages participated in the test. With acquired data, the multivariate largest Lyapunov exponent was calculated. Finally, the results of the proposed approach were analysed and compared with the traditional method, for which the largest Lyapunov exponent and power spectral density from the centre of pressure were also calculated. The following conclusions can be obtained. The multivariate largest Lyapunov exponent has a higher degree of differentiation in differentiating balance in eyes-closed conditions. The MLLE value reflects the overall coordination between multisegment movements. Individuals of different ages can be distinguished by their MLLE values. The standing stability of human is reduced with the increment of age. PMID:26064182

  17. A study on prevention of an electric discharge at an extraction electrode of an electron cyclotron resonance ion source for cancer therapy

    SciTech Connect

    Kishii, Y. Kawasaki, S.; Kitagawa, A.; Muramatsu, M.; Uchida, T.

    2014-02-15

    A compact ECR ion source has utilized for carbon radiotherapy. In order to increase beam intensity with higher electric field at the extraction electrode and be better ion supply stability for long periods, electric geometry and surface conditions of an extraction electrode have been studied. Focusing attention on black deposited substances on the extraction electrode, which were observed around the extraction electrode after long-term use, the relation between black deposited substances and the electrical insulation property is investigated. The black deposited substances were inspected for the thickness of deposit, surface roughness, structural arrangement examined using Raman spectroscopy, and characteristics of electric discharge in a test bench, which was set up to simulate the ECR ion source.

  18. Application of EM holographic methods to borehole vertical electric source data to map a fuel oil spill

    SciTech Connect

    Bartel, L.C.

    1993-04-01

    The multifrequency, multisource holographic method used in the analysis of seismic data is to extended electromagnetic (EM) data within the audio frequency range. The method is applied to the secondary magnetic fields produced by a borehole, vertical electric source (VES). The holographic method is a numerical reconstruction procedure based on the double focusing principle for both the source array and the receiver array. The approach used here is to Fourier transform the constructed image from frequency space to time space and set time equal to zero. The image is formed when the in-phase part (real part) is a maximum or the out-of-phase (imaginary part) is a minimum; i.e., the EM wave is phase coherent at its origination. In the application here the secondary magnetic fields are treated as scattered fields. In the numerical reconstruction, the seismic analog of the wave vector is used; i.e., the imaginary part of the actual wave vector is ignored. The multifrequency, multisource holographic method is applied to calculated model data and to actual field data acquired to map a diesel fuel oil spill.

  19. Thermal-electric coupled-field finite element modeling and experimental testing of high-temperature ion sources for the production of radioactive ion beams.

    PubMed

    Manzolaro, M; Meneghetti, G; Andrighetto, A; Vivian, G; D'Agostini, F

    2016-02-01

    In isotope separation on line facilities the target system and the related ion source are two of the most critical components. In the context of the selective production of exotic species (SPES) project, a 40 MeV 200 μA proton beam directly impinges a uranium carbide target, generating approximately 10(13) fissions per second. The radioactive isotopes produced in this way are then directed to the ion source, where they can be ionized and finally accelerated to the subsequent areas of the facility. In this work both the surface ion source and the plasma ion source adopted for the SPES facility are presented and studied by means of numerical thermal-electric models. Then, numerical results are compared with temperature and electric potential difference measurements, and finally the main advantages of the proposed simulation approach are discussed. PMID:26932055

  20. Thermal-electric coupled-field finite element modeling and experimental testing of high-temperature ion sources for the production of radioactive ion beams

    NASA Astrophysics Data System (ADS)

    Manzolaro, M.; Meneghetti, G.; Andrighetto, A.; Vivian, G.; D'Agostini, F.

    2016-02-01

    In isotope separation on line facilities the target system and the related ion source are two of the most critical components. In the context of the selective production of exotic species (SPES) project, a 40 MeV 200 μA proton beam directly impinges a uranium carbide target, generating approximately 1013 fissions per second. The radioactive isotopes produced in this way are then directed to the ion source, where they can be ionized and finally accelerated to the subsequent areas of the facility. In this work both the surface ion source and the plasma ion source adopted for the SPES facility are presented and studied by means of numerical thermal-electric models. Then, numerical results are compared with temperature and electric potential difference measurements, and finally the main advantages of the proposed simulation approach are discussed.

  1. Detail of the largest generator, an Enterprise 5000, also known ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Detail of the largest generator, an Enterprise 5000, also known as "Big Bertha", looking southeast - March Air Force Base, Strategic Air Command, Utility Building, 5220 Riverside Drive, Moreno Valley, Riverside County, CA

  2. Approximating the largest eigenvalue of network adjacency matrices

    NASA Astrophysics Data System (ADS)

    Restrepo, Juan G.; Ott, Edward; Hunt, Brian R.

    2007-11-01

    The largest eigenvalue of the adjacency matrix of a network plays an important role in several network processes (e.g., synchronization of oscillators, percolation on directed networks, and linear stability of equilibria of network coupled systems). In this paper we develop approximations to the largest eigenvalue of adjacency matrices and discuss the relationships between these approximations. Numerical experiments on simulated networks are used to test our results.

  3. Largest geomagnetic sudden commencement (SC) and interplanetary shock

    NASA Astrophysics Data System (ADS)

    Araki, Tohru

    2015-04-01

    The long term variation of amplitude of geomagnetic sudden commencements (SCs) is examined by checking old magnetograms at Kakioka (27.5 deg. geomagnetic latitude) and Alibag (10.3 deg.) and SC lists prepared by both stations. We found that the SC occurred on March 24, 1940 was largest since 1868. The amplitude is 310 nT at Alibag and larger than 273 nT at Kakioka. The magnetogram of Cape Town (-33.3 deg) was also available for this event which shows 164 nT amplitude. This SC occurred during the main phase of a large magnetic storm which has been interested as one of space weather events. The statistical analysis shows that the occurrence probability is less than 5 % for SCs with amplitude larger than 50 nT and less than 1 % for SCs larger than 100 nT at both Kakioka and Alibag. Large amplitude SCs tend to occur in the declining phase of the sun spot cycle as is reported for magnetic storms. Siscoe et al. (1968) firstly proposed the relationship for the solar wind dynamic pressure P and SC amplitude, dH as dH = C*d(P^0.5) where d(P^0.5) shows a jump of the square root of P associated with interplanetary shocks. If we take the proportionality constant C as 15 nT/(nPa)^0.5 and the 300 nT SC amplitude (dH) needs pressure jump from 2 nPa (assumed dynamic pressure in front of the shock) to 460 nPa. If the non-linear effect for magnetospheric compression is taken into account, a larger dynamic pressure will be needed for this large amplitude SC. On the other hand, the proportionality constant, C, might become larger for larger amplitude SC because C includes effects of electric currents induced in the earth. Larger amplitude SCs have larger time variation rate by which C becomes larger and the required dynamic pressure increase becomes smaller. We do not know which of the two competing processes is dominant but we consider that the linear estimation of the required dynamic pressure described above may be valid as the first order approximation.

  4. Development of double-pulse lasers ablation system for generating gold ion source under applying an electric field

    NASA Astrophysics Data System (ADS)

    Khalil, A. A. I.

    2015-12-01

    Double-pulse lasers ablation (DPLA) technique was developed to generate gold (Au) ion source and produce high current under applying an electric potential in an argon ambient gas environment. Two Q-switched Nd:YAG lasers operating at 1064 and 266 nm wavelengths are combined in an unconventional orthogonal (crossed-beam) double-pulse configuration with 45° angle to focus on a gold target along with a spectrometer for spectral analysis of gold plasma. The properties of gold plasma produced under double-pulse lasers excitation were studied. The velocity distribution function (VDF) of the emitted plasma was studied using a dedicated Faraday-cup ion probe (FCIP) under argon gas discharge. The experimental parameters were optimized to attain the best signal to noise (S/N) ratio. The results depicted that the VDF and current signals depend on the discharge applied voltage, laser intensity, laser wavelength and ambient argon gas pressure. A seven-fold increases in the current signal by increasing the discharge applied voltage and ion velocity under applying double-pulse lasers field. The plasma parameters (electron temperature and density) were also studied and their dependence on the delay (times between the excitation laser pulse and the opening of camera shutter) was investigated as well. This study could provide significant reference data for the optimization and design of DPLA systems engaged in laser induced plasma deposition thin films and facing components diagnostics.

  5. Multiple-DC-Inputs Direct Electric Power Converter D-EPC with DC Power Sources Connected in Series

    NASA Astrophysics Data System (ADS)

    Yoshimoto, Kantaro; Satou, Shou; Maikawa, Kengo; Takahashi, Kouji

    A series-type multiple-dc-inputs direct electric power converter (D-EPC) has been developed. The D-EPC is a multiple-dc-inputs inverter, and it can eliminate the need for a dc/dc converter that is generally used in conventional converter/inverter systems. The original D-EPC has two positive terminals and a negative terminal in common. Each upper arm between the positive terminal and the ac output is built with a bidirectional switch to prevent short circuit. In the series-type D-EPC, the input power sources are connected in series, thus, the number of bidirectional switches can be reduced and the series voltage can be used in the motor drive system. A new pulse width modulation (PWM) generation technique to drive switching devices in the series-type D-EPC has also been developed. Tests have confirmed that the motor can be operated by controlling the power distribution and that a series voltage can be used.

  6. Electrical-thermal-structural finite element simulation and experimental study of a plasma ion source for the production of radioactive ion beams

    NASA Astrophysics Data System (ADS)

    Manzolaro, M.; Meneghetti, G.; Andrighetto, A.; Vivian, G.

    2016-03-01

    The production target and the ion source constitute the core of the selective production of exotic species (SPES) facility. In this complex experimental apparatus for the production of radioactive ion beams, a 40 MeV, 200 μA proton beam directly impinges a uranium carbide target, generating approximately 1013 fissions per second. The transfer line enables the unstable isotopes generated by the 238U fissions in the target to reach the ion source, where they can be ionized and finally accelerated to the subsequent areas of the facility. In this work, the plasma ion source currently adopted for the SPES facility is analyzed in detail by means of electrical, thermal, and structural numerical models. Next, theoretical results are compared with the electric potential difference, temperature, and displacement measurements. Experimental tests with stable ion beams are also presented and discussed.

  7. Electrical-thermal-structural finite element simulation and experimental study of a plasma ion source for the production of radioactive ion beams.

    PubMed

    Manzolaro, M; Meneghetti, G; Andrighetto, A; Vivian, G

    2016-03-01

    The production target and the ion source constitute the core of the selective production of exotic species (SPES) facility. In this complex experimental apparatus for the production of radioactive ion beams, a 40 MeV, 200 μA proton beam directly impinges a uranium carbide target, generating approximately 10(13) fissions per second. The transfer line enables the unstable isotopes generated by the (238)U fissions in the target to reach the ion source, where they can be ionized and finally accelerated to the subsequent areas of the facility. In this work, the plasma ion source currently adopted for the SPES facility is analyzed in detail by means of electrical, thermal, and structural numerical models. Next, theoretical results are compared with the electric potential difference, temperature, and displacement measurements. Experimental tests with stable ion beams are also presented and discussed. PMID:27036768

  8. Source analysis of median nerve and finger stimulated somatosensory evoked potentials: multichannel simultaneous recording of electric and magnetic fields combined with 3D-MR tomography.

    PubMed

    Buchner, H; Fuchs, M; Wischmann, H A; Dössel, O; Ludwig, I; Knepper, A; Berg, P

    1994-01-01

    At the current state of technology, multichannel simultaneous recording of combined electric potentials and magnetic fields should constitute the most powerful tool for separation and localization of focal brain activity. We performed an explorative study of multichannel simultaneous electric SEPs and magnetically recorded SEFs. MEG only sees tangentially oriented sources, while EEG signals include the entire activity of the brain. These characteristics were found to be very useful in separating multiple sources with overlap of activity in time. The electrically recorded SEPs were adequately modelled by three equivalent dipoles located: (1) in the region of the brainstem, modelling the P14 peak at the scalp, (2) a tangentially oriented dipole, modelling the N20-P20 and N30-P30 peaks, and part of the P45, and (3) a radially oriented dipole, modelling the P22 peak and part of the P45, both located in the region of the somatosensory cortex. Magnetically recorded SEFs were adequately modelled by a single equivalent dipole, modelling the N20-P20 and N30-P30 peaks, located close to the posterior bank of the central sulcus, in area 3b (mean deviation: 3 mm). The tangential sources in the electrical data were located 6 mm on average from the area 3b. MEG and EEG was able to locate the sources of finger stimulated SEFs in accordance with the somatotopic arrangement along the central fissure. A combined analysis demonstrated that MEG can provide constraints to the orientation and location of sources and helps to stabilize the inverse solution in a multiple-source model of the EEG. PMID:7946929

  9. Time scale of the largest imaginable magnetic storm

    NASA Astrophysics Data System (ADS)

    Vasyliūnas, V. M.

    2013-01-01

    The depression of the horizontal magnetic field at Earth's equator for the largest imaginable magnetic storm has been estimated (Vasyliūnas, 2011a) as -Dst ~ 2500 nT, from the assumption that the total pressure in the magnetosphere (plasma plus magnetic field perturbation) is limited, in order of magnitude, by the minimum pressure of Earth's dipole field at the location of each flux tube. The obvious related question is how long it would take the solar wind to supply the energy content of this largest storm. The maximum rate of energy input from the solar wind to the magnetosphere can be evaluated on the basis either of magnetotail stress balance or of polar cap potential saturation, giving an estimate of the time required to build up the largest storm, which (for solar-wind and magnetospheric parameter values typical of observed superstorms) is roughly between ~2 and ~6 h.

  10. Electrical resistivity structure of the Valu Fa Ridge, Lau Basin, from marine controlled-source electromagnetic sounding

    NASA Astrophysics Data System (ADS)

    MacGregor, Lucy; Sinha, Martin; Constable, Steven

    2001-07-01

    In December 1995 we carried out a comprehensive controlled-source electromagnetic survey of the Valu Fa Ridge at 22°25'S in the Lau Basin. The Valu Fa Ridge is a back-arc spreading centre of intermediate spreading rate and is a site of extensive hydrothermal activity. Seismic studies have imaged a melt lens at an average depth of 3.2km below the seafloor, surrounded by a zone of lowered seismic velocity, interpreted as a region of partial melt in the crust. The electromagnetic experiment was part of a multidisciplinary study which included wide-angle and reflection seismics, bathymetry and potential field measurements. Electromagnetic signals at frequencies between 0.25 and 40Hz were transmitted from a horizontal electric dipole towed close to the seafloor and were recorded by an array of 11 sea-bottom receivers at ranges of up to 20km from the source. Over 80 hr of data, consisting of the magnitude of the horizontal electric field at the seafloor, were collected. These data have extremely low scatter compared to similar data from previous surveys. The data were interpreted using a combination of 1- and 2-D forward modelling and inversion. The vertical resistivity gradient in the upper crust at the Valu Fa Ridge is abnormally low, with resistivities of less than 10Ω m observed throughout layer 2 of the crust to a depth of 3km. This is significantly more conductive at depth than the axis of the slow-spreading Reykjanes Ridge at 57°45'N, and the fast-spreading East Pacific Rise at 13°N, where similar data sets have been collected in the past. Although the structure of layer 2 is well constrained by the electromagnetic data, its extremely low resistivity causes rapid attenuation of electromagnetic signals diffusing through it, and hence the data are not sensitive to the structure in layer 3, in particular the structure of the melt lens or surrounding low-velocity zone. The seismic velocity structure of the Valu Fa Ridge, determined from the coincident wide