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. POWER SOURCES FOR ELECTRIC CARS.

    DTIC Science & Technology

    An extrapolation, based on extensive experience with battery and fuel cell power sources during various Army programs, is made into the future world...of the electric car and speculates on the power sources most suited as the electrical energy source. The conclusion is that both the battery and the

  3. 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)

  4. Stand by electrical supply source

    SciTech Connect

    Mucsy, E.; Hoos, K.

    1985-06-25

    A stand-by electrical energy source for equipment to be operated with substantially continuous current supply, comprising three components one of which is at least one electric rotary machine, another of which is a flywheel and the third of which is an auxiliary energy source. Planetary gearing is provided, comprising a central shaft on which is mounted a sun gear, a planet gear and a ring gear, each of the three components being connected with a respective one of these gears. Two of the three components are interconnected by a drive with an infinitely variable transmission. In one embodiment, the electric rotary machine is connected to the planet gear, the flywheel is connected to the sun gear and the auxiliary energy source is connected with the ring gear. In another embodiment, the electric rotary machine is connected to the sun gear, the flywheel is connected to the ring gear, and the auxiliary energy source is connected to the planet gear.

  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. 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.

  7. Impact of closing Canada's largest point-source of mercury emissions on local atmospheric mercury concentrations.

    PubMed

    Eckley, Chris S; Parsons, Matthew T; Mintz, Rachel; Lapalme, Monique; Mazur, Maxwell; Tordon, Robert; Elleman, Robert; Graydon, Jennifer A; Blanchard, Pierrette; St Louis, Vincent

    2013-09-17

    The Flin Flon, Manitoba copper smelter was Canada's largest point source of mercury emissions until its closure in 2010 after ~80 years of operation. The objective of this study was to understand the variables controlling the local ground-level air mercury concentrations before and after this major point source reduction. Total gaseous mercury (TGM) in air, mercury in precipitation, and other ancillary meteorological and air quality parameters were measured pre- and postsmelter closure, and mercury speciation measurements in air were collected postclosure. The results showed that TGM was significantly elevated during the time period when the smelter operated (4.1 ± 3.7 ng m(-3)), decreased only 20% during the year following its closure, and remained ~2-fold above background levels. Similar trends were observed for mercury concentrations in precipitation. Several lines of evidence indicated that while smelter stack emissions would occasionally mix down to the surface resulting in large spikes in TGM concentrations (up to 61 ng m(-3)), the largest contributor to elevated TGM concentrations before and after smelter closure was from surface-air fluxes from mercury-enriched soils and/or tailings. These findings highlight the ability of legacy mercury, deposited to local landscapes over decades from industrial activities, to significantly affect local air concentrations via emissions/re-emissions.

  8. 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.

  9. Iceland as the largest source of natural air pollution in the Arctic

    NASA Astrophysics Data System (ADS)

    Dagsson Waldhauserova, Pavla; Meinander, Outi; Olafsson, Haraldur; Arnalds, Olafur

    2017-04-01

    Arctic aerosols are often attributed to the Arctic Haze and long-range transport tracers. There is, however, an important dust source in the Arctic/Sub-arctic region which should receive more attention. The largest desert in the Arctic as well as in the Europe is Iceland with > 40,000 km2 of desert areas. The mean dust suspension frequency was 135 dust days annually in 1949-2012 with decreasing numbers in 2013-2015. The annual dust deposition was calculated as 31-40 million tons yr-1 affecting the area of > 500,000 km2. Satelite MODIS pictures have revealed dust plumes traveling > 1000 km at times. The physical properties of Icelandic dust showed differences in mineralogy, geochemical compositions, shapes, sizes, and colour, compared to the crustal mineral dust. Icelandic dust is of volcanic origin, dark in colour with sharp-tipped shards and large bubbles. About 80% of the particulate matter is volcanic glass rich in heavy metals, such as iron and titanium. Suspended dust measured at the glacial dust source consisted of such high number of close-to-ultrafine particles as concentrations during active eruptions. Generally, about 50% of the suspended PM10 are submicron particles in Iceland. Contrarily, suspended grains > 2 mm were captured during severe dust storm after the 2010 Eyjafjallajokull eruption when the aeolian transport exceeded 11 t m-1 of materials and placed this storms among the most extreme wind erosion events recorded on Earth. Our reflectance measurements showed that Icelandic dust deposited on snow lowers the snow albedo and reduces the snow density as much as Black Carbon. Icelandic volcanic dust tends to act as a positive climate forcing agent, both directly and indirectly, which is different to what generally concluded for crustal dust in the 2013 IPCC report. The high frequency, severity and year-round activity of volcanic dust emissions suggest that Icelandic dust may contribute to Arctic warming.

  10. 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.

  11. 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.

  12. Electrically driven and electrically tunable quantum light sources

    NASA Astrophysics Data System (ADS)

    Lee, J. P.; Murray, E.; Bennett, A. J.; Ellis, D. J. P.; Dangel, C.; Farrer, I.; Spencer, P.; Ritchie, D. A.; Shields, A. J.

    2017-02-01

    Compact and electrically controllable on-chip sources of indistinguishable photons are desirable for the development of integrated quantum technologies. We demonstrate that two quantum dot light emitting diodes (LEDs) in close proximity on a single chip can function as a tunable, all-electric quantum light source. Light emitted by an electrically excited driving LED is used to excite quantum dots in the neighbouring diode. The wavelength of the quantum dot emission from the neighbouring driven diode is tuned via the quantum confined Stark effect. We also show that we can electrically tune the fine structure splitting.

  13. Electrical Neuroimaging with Irrotational Sources.

    PubMed

    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.

  14. 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

  15. 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.

  16. Mapping the World's Largest Natural Gas Leak and Other Methane Sources Using High Resolution Spectroscopy

    NASA Astrophysics Data System (ADS)

    Sander, Stanley P.; Wong, Clare; Pongetti, Thomas J.

    2016-06-01

    CH_4 is a potent greenhouse gas with a 100-year Global Warming Potential more than thirty times larger than CO_2 if carbon-climate feedbacks are considered. In urban areas such as Los Angeles, anthropogenic methane emissions are poorly characterized because of the large diversity of sources: landfills, sewage treatment plants, agriculture, leaks in the natural gas distribution system, cattle and dairy farms, thermogenic emissions from oil fields and seeps. The California Laboratory for Atmospheric Remote Sensing (CLARS), operated by the Jet Propulsion Laboratory, is a mountaintop facility overlooking most of the Los Angeles basin, equipped with JPL-built Fourier transform spectrometers for measurements of the slant column abundances of several greenhouse gases including methane with high spatial and temporal resolution. This presentation will cover several topics including the design features of the two FTS instruments, spectroscopic issues associated with the retrieval of slant column abundances, and uncertainty analysis. One FTS has been in continuous operation since 2011, providing sufficient data to identify several CH_4 emission hot spots in the LA basin. On October 23, 2015, a well pipe suffered a failure in a natural gas storage facility in Aliso Canyon, northwest of downtown Los Angeles resulting in a massive CH_4 plume transported by winds throughout the LA basin. The CLARS FTS captured the plume propagation throughout the 4-month duration of the leak. We will show how the emission ratio method may be employed to derive a lower bound to the CH_4 emission rate from the leaking well without the use of complex atmospheric transport models. The CLARS measurement system provides a small-scale example of the data that would be acquired by an imaging FTS on a geostationary space platform. copyright 2016, California Institute of Technology. Government sponsorship acknowledged.

  17. 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.

  18. 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.

  19. Nuclear power source for electric propulsion

    NASA Technical Reports Server (NTRS)

    Mondt, J. F.; Stapfer, G.; Hsieh, T.

    1979-01-01

    A low specific weight (20 to 40 Kg/Kwe), long life (6 to 10 year), 100 to 400 KWe nuclear electric propulsion (NEP) system can deliver 2,000 to 10,000 Kg payloads for intensive study of our solar system. The nuclear power source is about 80% of the NEP system mass, thus the NASA program is focused on developing the power source technology. Because of the long life requirements, direct thermal to electric energy conversion technology (thermionic and thermoelectric) is being pursued. In order to meet the low specific weight it is necessary to develop a 10 to 15% conversion module with a 875 K minimum heat rejection temperature and a 1675 K maximum input temperature. The thermoionic converter is about 9% efficient at these temperatures. The thermoelectric converter is limited to a 1300 K input temperature. So, the thermionic program is focused on improving the efficiency while the thermoelectric program is focused on increasing the temperature.

  20. 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.

  1. 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.

  2. 77 FR 18872 - Availability of Electric Power Sources

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-28

    ... 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 describes actions the NRC staff considers acceptable when available electric power sources are less than the number...

  3. 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 power...

  4. 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 power...

  5. 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)...

  6. 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)...

  7. 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... 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)...

  8. 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.

  9. 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... 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...

  10. 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...

  11. 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...

  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 28.850 - 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...

  14. 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...

  15. 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... 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...

  16. 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 28.870 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...

  17. 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 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...

  18. Spectral studies of the sources of ionospheric electric fields

    NASA Technical Reports Server (NTRS)

    Earle, G. D.; Kelley, M. C.

    1987-01-01

    Spectral analyses (applying the Fourier analysis methods) were performed on three incoherent scatter radar data sets (obtained at Jicamarca, Peru; Chatanika, Alaska; and Arecibo, Puerto Rico) with the aim of investigating the origin of ionospheric electric fields in the frequency range of 0.01-2 cycles/h. In quiet times, atmospheric gravity waves appeared to be the most likely source of the ionospheric electric field. This hypothesis was tested by a direct simultaneous comparison of measurements of gravity waves in the mesosphere and of electric fields in the thermosphere during very quiet conditions. The results indicated that a gravity wave source is a plausible candidate for the electric field fluctuations.

  19. Electric Discharge Excitation and Energy Source Integration.

    DTIC Science & Technology

    1985-01-06

    perfluorinated ester fluid in the Ferrofluidics feedthrough [perfluoro bis (2-ethylhexyl)azelate] and the insulator used in the preionization mount...outcoupler. Maximum gas pressure was limited to 2 atm by the Ferrofluidic seal. Inconsistencies were apparent in some of the data obtained. Upon disassembly...Rate Closed-Cycle Rare Gas Electrical Discharge Laser," Rev. Sci. Instrum. 47, 677 (1976). 31. Ferrofluidic is a registered trademark of Ferrofluidics

  20. 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)

  1. Economic Comparison of Four Electric Power Sources for Forklift Trucks.

    DTIC Science & Technology

    The purpose of this project is twofold. First, it is to provide a general method of comparing electric power sources (EPS). Secondly, it is to...compare two power sources , the lithium chloride storage battery and a hybrid system of a storage battery and a fuel cell, currently under development at...between power sources . The results show that the lithium chloride battery is the most cost effective EPS considered.

  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. Spectral studies of the sources of ionospheric electric fields

    SciTech Connect

    Earle, G.D.; Kelley, M.C. )

    1987-01-01

    Spectral analyses have been performed upon a number of incoherent scatter radar data sets obtained at Jicamarca, Peru; Chatanika, Alaska; and Arecibo, Puerto Rico, with the goal of understanding the sources of electric fields with periods in the range of 1-10 hours. Two distinct sources are identified and studied in some detail. In quiet times, atmospheric gravity waves seem the most likely source of the ionospheric electric field. In fact, both in an average sense and in the single case study available the mesospheric winds measured at Poker Flat, Alaska, in this frequency range are remarkably similar in magnitude to the quiet time thermospheric plasma drifts measured overhead by the nearby Chatanika radar. Such drifts are driven by electric fields which, the authors argue, could easily be generated by the observed wind fields. Comparison with the spectra of electric field measurements at other latitudes suggests that such a source is worldwide and determines the geophysical noise level of low- and mid-latitude electric field measurements. Turning to active times, the authors present a measure of the transfer function for electric field measurements. Turning to active times, they present a measure of the transfer function for electric field penetration between high- and low-altitude L shells. At the very lowest frequencies (periods of {ge} 10 hours) the low-altitude sites are well shielded, presumably by an Alfven layer at the inner edge of the ring current. Higher frequency fluctuations penetrate very easily to low latitudes. A response peak seems to occur in the 3- to 5-hour range of periods, with a lower response occurring at 1 cycle/hour, although this result must be viewed as preliminary for now. Between L = 5.5 and L = 1.4 the zonal electric field component as projected to the equatorial plane of the magnetosphere penetrates with little or no attenuation.

  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. 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. Copyright © 2015 The American Physiological Society.

  6. 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.

  7. Semiconductor light source with electrically tunable emission wavelength

    DOEpatents

    Belenky, Gregory; Bruno, John D.; Kisin, Mikhail V.; Luryi, Serge; Shterengas, Leon; Suchalkin, Sergey; Tober, Richard L.

    2011-01-25

    A semiconductor light source comprises a substrate, lower and upper claddings, a waveguide region with imbedded active area, and electrical contacts to provide voltage necessary for the wavelength tuning. The active region includes single or several heterojunction periods sandwiched between charge accumulation layers. Each of the active region periods comprises higher and lower affinity semiconductor layers with type-II band alignment. The charge carrier accumulation in the charge accumulation layers results in electric field build-up and leads to the formation of generally triangular electron and hole potential wells in the higher and lower affinity layers. Nonequillibrium carriers can be created in the active region by means of electrical injection or optical pumping. The ground state energy in the triangular wells and the radiation wavelength can be tuned by changing the voltage drop across the active region.

  8. The Largest Hydraulic Fracturing - Induced Earthquake in Canada: Source Characteristics and Seismic Hazard Implications of the August 17, 2015, Mw 4.6 Earthquake in Northeast British Columbia

    NASA Astrophysics Data System (ADS)

    Schultz, R.; Kao, H.; Babaie Mahani, A.

    2016-12-01

    The northeast British Columbia (BC) and western Alberta (AB) are major production areas of shale gas in Canada. Historically, the region was characterized by low level of natural seismicity. However, the number of local earthquakes has increased significantly since the development of shale gas, mainly due to the operations of hydraulic fracturing and wastewater injection. On August 17, 2015, an Mw 4.6 earthquake occurred in the northern Montney Play about 115 km NW of Fort St. John, BC. A series of aftershocks were detected in the epicentral area following the mainshock. Both the mainshock and its aftershock sequence were well recorded by the regional broadband seismograph network, but the closest station is located 65 km away. By incorporating industry-provided datasets from dense seismic arrays in the source area, we study the source characteristics of this earthquake sequence by conducting moment-tensor inversion for the mainshock and one of the largest aftershocks. Double difference relocation of the aftershock sequence is performed as well to constrain the source dimension. Our results indicate the mainshock occurred on a reverse fault striking NW-SE at a very shallow depth of 3 km. It is consistent with the distribution of most aftershocks at depths ranging from 1.4 to 2.5 km. Spatial and temporal correlation of seismic activity with the fluid injection in the region revealed that these events are better correlated with hydraulic fracturing (> 99.99% confidence) than disposal. It is somewhat surprising that waveform clipping was observed at broadband seismograph stations at distances up to 40 km from the mainshock's epicenter. Based on the amplitude ratio of unclipped waveforms between the mainshock and a smaller Mw 3.0 aftershock at stations farther away, we estimate that the peak ground acceleration (PGA) from the Mw 4.6 event could have reached 17% g at the epicentral distance of 5 km. Our analysis suggests that level of ground motion from a moderately

  9. 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.

  10. 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.

  11. 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.

  12. Scoping calculations of power sources for nuclear electric propulsion

    NASA Astrophysics Data System (ADS)

    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 make scoping calculations for mission analysis.

  13. 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

  14. Alternative current source based Schottky contact with additional electric field

    NASA Astrophysics Data System (ADS)

    Mamedov, R. K.; Aslanova, A. R.

    2017-07-01

    Additional electric field (AEF) in the Schottky contacts (SC) that covered the peripheral contact region wide and the complete contact region narrow (as TMBS diode) SC. Under the influence of AEF is a redistribution of free electrons produced at certain temperatures of the semiconductor, and is formed the space charge region (SCR). As a result of the superposition of the electric fields SCR and AEF occurs the resulting electric field (REF). The REF is distributed along a straight line perpendicular to the contact surface, so that its intensity (and potential) has a minimum value on the metal surface and the maximum value at a great distance from the metal surface deep into the SCR. Under the influence of AEF as a sided force the metal becomes negative pole and semiconductor - positive pole, therefore, SC with AEF becomes an alternative current source (ACS). The Ni-nSi SC with different diameters (20-1000 μm) under the influence of the AEF as sided force have become ACS with electromotive force in the order of 0.1-1.0 mV, which are generated the electric current in the range of 10-9-10-7 A, flowing through the external resistance 1000 Ohm.

  15. Surplus from and storage of electricity generated by intermittent sources

    NASA Astrophysics Data System (ADS)

    Wagner, Friedrich

    2016-12-01

    Data from the German electricity system for the years 2010, 2012, 2013, and 2015 are used and scaled up to a 100% supply by intermittent renewable energy sources (iRES). In the average, 330GW wind and PV power are required to meet this 100% target. A back-up system is necessary with the power of 89% of peak load. Surplus electricity accrues at high power levels. Curtailing surplus power to a large extent is found to be uneconomic. Demand-side management will suffer from the strong day-to-day variation of available surplus energy. A day storage is ineffective because of the day-night correlation of surplus power during winter. A seasonal storage loses its character when transformation losses are considered because it can contribute only after periods with excessive surplus production. The option of an oversized iRES system to feed the storage is also not effective because, in this case, energy can be taken directly from the large iRES supply, making storage superfluous. The capacities to be installed stress the difficulty to base heat supply and mobility also on iRES generated electricity in the future. As the German energy transition replaces one CO2-free electricity supply system by another one, no major reduction in CO2 emission can be expected till 2022, when the last nuclear reactor will be switched off. By 2022, an extremely oversized power supply system has to be created, which can be expected to continue running down spot-market electricity prices. The continuation of the economic response -to replace expensive gas fuel by cheap lignite- causes an overall increase in CO2 emission. The German GHG emission targets for 2020 and beyond are therefore in jeopardy.

  16. 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.

  17. Nonsingular black hole with a nonlinear electric source

    NASA Astrophysics Data System (ADS)

    Culetu, Hristu

    2015-04-01

    A modified version of the Reissner-Nordstrom (RN) metric is proposed on the grounds of the nonlinear electrodynamics model. The source of curvature is an anisotropic fluid with pr = -ρ which resembles the Maxwell stress tensor at r ≫ q2/2m, where q and m are the mass and charge of the particle, respectively. We found the black hole (BH) horizon entropy obeys the relation S = ∣W∣/2T = AH/4, with W the Komar energy and AH the horizon area. The electric field around the source depends not only on its charge but also on its mass. The corresponding electrostatic potential Φ(r) is finite everywhere, being -m/2q at the origin and nonzero asymptotically, with Φ∞ = m/q.

  18. Interrogation of electrical connector faults using miniaturized UWB sources

    NASA Astrophysics Data System (ADS)

    Tokgöz, Çaǧata; Dardona, Sameh

    2017-01-01

    A diagnostic method for the detection, identification, and characterization of precursors of faults due to partial insertion of pin-socket contacts within electrical connectors commonly used in avionics systems is presented. It is demonstrated that a miniaturized ultrawideband (UWB) source and a minispectrum analyzer can be employed to measure resonant frequency shifts in connector S parameters as a small and low-cost alternative to a large and expensive network analyzer. The transfer function of an electrical connector is represented as a ratio of the spectra measured using the spectrum analyzer with and without the connector. Alternatively, the transfer function is derived in terms of the connector S parameters and the reflection coefficients at both ports of the connector. The transfer function data obtained using this derivation agreed well with its representation as a measured spectral ratio. The derivation enabled the extraction of the connector S parameters from the measured transfer function data as a function of the insertion depth of a pin-socket contact within the connector. In comparison with the S parameters measured directly using a network analyzer at multiple insertion depths, the S parameters extracted from the measured transfer function showed consistent and reliable representation of the electrical connector fault. The results demonstrate the potential of integrating a low-cost miniaturized UWB device into a connector harness for real-time detection of precursors to partially inserted connector faults.

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

    PubMed

    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 100 nm (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.

  20. 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.

  1. 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

  2. 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.

  3. Formation of the lunar crust - An electrical source of heating

    NASA Technical Reports Server (NTRS)

    Sonett, C. P.; Colburn, D. S.; Schwartz, K.

    1975-01-01

    A model for formation of the lunar crust based on heating by electrical induction is explored, while adherence is maintained to certain constraints associated with existing models of the solar system. The heating mechanism is based on eddy current induction from disordered magnetic fields swept outwards by an intense (T Tauri-like) plasma flow from the sun. The electrical theory is an alternative to intense short-period accretion as a source of heat for the evolution of lunar maria and highlands, provided that long-lived radioactives are not swept to the surface from too large a melt volume during the initial thermal episode. This formation of the lunar highlands does not intrinsically require rapid accretion, nor on this basis is the time of formation of the planets generally restricted to a very short time. The threshold temperature for eddy current heating is attained by either a solar nebula at 300-400 C during formation of the moon or a very low energy long-period accumulation of the moon, both leading to melting in ten to the fifth to ten to the seventh power years.

  4. Formation of the lunar crust - An electrical source of heating

    NASA Technical Reports Server (NTRS)

    Sonett, C. P.; Colburn, D. S.; Schwartz, K.

    1975-01-01

    A model for formation of the lunar crust based on heating by electrical induction is explored, while adherence is maintained to certain constraints associated with existing models of the solar system. The heating mechanism is based on eddy current induction from disordered magnetic fields swept outwards by an intense (T Tauri-like) plasma flow from the sun. The electrical theory is an alternative to intense short-period accretion as a source of heat for the evolution of lunar maria and highlands, provided that long-lived radioactives are not swept to the surface from too large a melt volume during the initial thermal episode. This formation of the lunar highlands does not intrinsically require rapid accretion, nor on this basis is the time of formation of the planets generally restricted to a very short time. The threshold temperature for eddy current heating is attained by either a solar nebula at 300-400 C during formation of the moon or a very low energy long-period accumulation of the moon, both leading to melting in ten to the fifth to ten to the seventh power years.

  5. 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... 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...

  6. 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... 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...

  7. 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...

  8. 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... 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...

  9. 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...

  10. 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...

  11. 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...

  12. 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...

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

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 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, 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...

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

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 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. Triton - Neptune Largest Satellite

    NASA Image and Video Library

    1999-07-25

    Intriguing patterns of unknown origin appeared on the surface of Neptune largest satellite, Triton, in this image returned by NASA Voyager 2 on Aug. 22, 1989. Voyager images showed that Triton is one of the brightest objects in the solar system,

  17. 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…

  18. 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…

  19. 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.

  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 Astrophysics Data System (ADS)

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

    1993-12-01

    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. Food contamination with organic materials in perspective: packaging materials as the largest and least controlled source? A view focusing on the European situation.

    PubMed

    Grob, Koni; Biedermann, Maurus; Scherbaum, Ellen; Roth, Maria; Rieger, Karl

    2006-01-01

    The comparison of the various sources of food contamination with organic chemicals suggests that in the public, but also among experts, the perception of risk is often distorted. Firstly, neither pesticides nor environmental pollutants contribute the most; the amount of material migrating from food packaging into food may well be 100 times higher. Secondly, control of these large migrants is often lagging behind the standards set up for other sources, since many of the components (particularly those not being "starting materials") have not been identified and, thus, not toxicologically evaluated. Finally, attitudes towards different types of food contaminants are divergent, also reflected by the legal measures: for most sources of food contamination there are strict rules calling for minimization, whereas the European packaging industry has even requested a further increase in the tolerance to as close as possible to the limit set by the toxicologists. This paper calls for a more realistic perception and more coherent legal measures-and improvements in the control of migration from packaging material.

  3. The largest fossil rodent

    PubMed Central

    Rinderknecht, Andrés; Blanco, R. Ernesto

    2008-01-01

    The discovery of an exceptionally well-preserved skull permits the description of the new South American fossil species of the rodent, Josephoartigasia monesi sp. nov. (family: Dinomyidae; Rodentia: Hystricognathi: Caviomorpha). This species with estimated body mass of nearly 1000 kg is the largest yet recorded. The skull sheds new light on the anatomy of the extinct giant rodents of the Dinomyidae, which are known mostly from isolated teeth and incomplete mandible remains. The fossil derives from San José Formation, Uruguay, usually assigned to the Pliocene–Pleistocene (4–2 Myr ago), and the proposed palaeoenvironment where this rodent lived was characterized as an estuarine or deltaic system with forest communities. PMID:18198140

  4. The largest fossil rodent.

    PubMed

    Rinderknecht, Andrés; Blanco, R Ernesto

    2008-04-22

    The discovery of an exceptionally well-preserved skull permits the description of the new South American fossil species of the rodent, Josephoartigasia monesi sp. nov. (family: Dinomyidae; Rodentia: Hystricognathi: Caviomorpha). This species with estimated body mass of nearly 1000kg is the largest yet recorded. The skull sheds new light on the anatomy of the extinct giant rodents of the Dinomyidae, which are known mostly from isolated teeth and incomplete mandible remains. The fossil derives from San José Formation, Uruguay, usually assigned to the Pliocene-Pleistocene (4-2Myr ago), and the proposed palaeoenvironment where this rodent lived was characterized as an estuarine or deltaic system with forest communities.

  5. Special electrical machines: Sources and converters of energy

    NASA Astrophysics Data System (ADS)

    Bertinov, A. I.; But, D. A.; Miziurin, S. R.; Alievskii, B. L.; Sineva, N. V.

    The principles underlying the operation of electromechanical and dynamic energy converters are discussed, along with those for the direct conversion of solar, thermal, and chemical energy into electrical energy. The theory for electromechanical and dynamic converters is formulated using a generalized model for the electromechanical conversion of energy. Particular attention is given to electrical machinery designed for special purposes. Features of superconductor electrical machines are discussed.

  6. 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

  7. Sources of Low-latitude Ionospheric Electric-field Disturbances

    NASA Astrophysics Data System (ADS)

    Richmond, A. D.; Peymirat, C.

    2001-12-01

    Storm-time ionospheric electric-field disturbances at middle and low latitudes are generated both by direct magnetosphere-ionosphere interactions at high latitudes and by secondary effects of disturbance thermospheric winds. These disturbance electric fields can have a strong influence on the equatorial ionosphere. Using the NCAR Magnetosphere-Thermosphere-Ionosphere-Electrodynamics General Circulation Model (MTIEGCM), we simulate low-latitude electric-field disturbances associated with direct penetration from high latitudes and with secondary generation by disturbed thermospheric winds. The simulations display a number of features observed in equatorial electric fields on time scales of minutes to hours. Models like the MTIEGCM, together with simultaneous global observations of ionospheric electric fields and thermospheric winds, can help clarify the relative importance of the different mechanisms that produce ionospheric disturbances.

  8. Milliwatt Electric Power Sources Would Last For Years

    NASA Technical Reports Server (NTRS)

    Chmielewski, Arthur; Borshchevsky, Alexander; Vining, Cronin

    1994-01-01

    Report discusses design of proposed radioisotope thermoelectric generators, each of which produces about 30 mW of electric power for decades, fits in package about the size of D cell, and would have mass of only 70 g.

  9. 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.

  10. 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.

  11. 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.

  12. Analyzing of economic growth based on electricity consumption from different sources

    NASA Astrophysics Data System (ADS)

    Maksimović, Goran; Milosavljević, Valentina; Ćirković, Bratislav; Milošević, Božidar; Jović, Srđan; Alizamir, Meysam

    2017-10-01

    Economic growth could be influenced by different factors. In this study was analyzed the economic growth based on the electricity consumption form different sources. As economic growth indicator gross domestic product (GDP) was used. ANFIS (adaptive neuro fuzzy inference system) methodology was applied to determine the most important factors from the given set for the GDP growth prediction. Six inputs were used: electricity production from coal, hydroelectric, natural gas, nuclear, oil and renewable sources. Results shown that the electricity consumption from renewable sources has the highest impact on the economic or GDP growth prediction.

  13. 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.

  14. 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.

  15. 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.

  16. An advanced electric propulsion diagnostic (AEPD) platform for in-situ characterization of electric propulsion thrusters and ion beam sources

    NASA Astrophysics Data System (ADS)

    Bundesmann, Carsten; Eichhorn, Christoph; Scholze, Frank; Spemann, Daniel; Neumann, Horst; Pagano, Damiano; Scaranzin, Simone; Scortecci, Fabrizio; Leiter, Hans J.; Gauter, Sven; Wiese, Ruben; Kersten, Holger; Holste, Kristof; Köhler, Peter; Klar, Peter J.; Mazouffre, Stéphane; Blott, Richard; Bulit, Alexandra; Dannenmayer, Käthe

    2016-10-01

    Experimental characterization is an essential task in development, qualification and optimization process of electric propulsion thrusters or ion beam sources for material processing, because it can verify that the thruster or ion beam source fulfills the requested mission or application requirements, and it can provide parameters for thruster and plasma modeling. Moreover, there is a need for standardizing electric propulsion thruster diagnostics in order to make characterization results of different thrusters and also from measurements performed in different vacuum facilities reliable and comparable. Therefore, we have developed an advanced electric propulsion diagnostic (AEPD) platform, which allows a comprehensive in-situ characterization of electric propulsion thrusters (or ion beam sources) and could serve as a standard on-ground tool in the future. The AEPD platform uses a five-axis positioning system and provides the option to use diagnostic tools for beam characterization (Faraday probe, retarding potential analyzer, ExB probe, active thermal probe), for optical inspection (telemicroscope, triangular laser head), and for thermal characterization (pyrometer, thermocamera). Here we describe the capabilities of the diagnostic platform and provide first experimental results of the characterization of a gridded ion thruster RIT- μX.

  17. 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.

  18. 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.

  19. 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.

  20. Comparative source localization of electrically and pressure-stimulated multichannel somatosensory evoked potentials.

    PubMed

    Kawohl, Wolfram; Waberski, Till Dino; Darvas, Felix; Norra, Christine; Gobbelé, René; Buchner, Helmut

    2007-06-01

    The purpose of the study was to determine if there is a difference in the determination of the cortical hand area by dipole source estimation after artificial and natural stimuli. In principle, there are advantages of both methods: pressure stimulation is less invasive and compatible to fMRI, whereas electrical stimulation can be applied with higher stimulus rates and elicits sharper waveforms. Electrical and pressure stimulation was performed simultaneously on the thumb and fifth finger on eight healthy volunteers. The somatosensory evoked potentials after electrical stimulation showed sharper peaks and higher amplitudes than the pressure stimulated potentials. For the two stimulus qualities, cortical source positions of thumb and fifth finger separated significantly in the vertical z-axis. Both methods deliver reliable stimulation and therefore allow separate source localization of thumb and fifth finger. For cortical plasticity studies, peripheral somatosensory stimulation is of great importance. According to these findings, the choice of method, electrical or mechanical stimulation, may depend on practical criteria.

  1. 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.

  2. Electrical potential source mechanisms in microbial induced sulfate reducing environments

    NASA Astrophysics Data System (ADS)

    Zhang, C.; Slater, L.; Ntarlagiannis, D.; Singh, K.; Doherty, R.

    2007-12-01

    In order to compare self-potential (SP) signals resulting from possible 'geobattery' effects with electrodic potential signals based on a known galvanic cell (GC) effect in the presence of sulfide, we designed a column experiment using dual sensor Ag-AgCl electrodes. Water from the Langan River (Belfast, UK), known to contain a sulfate reducing microbial community, was obtained. Two experimental columns were packed with fine-grained glass beads. One column continuously circulated (closed loop) with autoclaved river water as a control, while the other retained biologically active natural river water. Six Ag-AgCl electrodes equally spaced along one side of each column, and three Ag-AgCl self potential electrodes (where the metal is in electrolytic contact with the column via a sterilized 1M KCl agar gel), were placed on the other side of each column. Electrical potential signals were continuously recorded with both sensor types. Induced polarization, electrical resistivity, temperature and aqueous geochemistry measurements (pH, Eh, and conductivity) were taken once daily. Over the 20 day experiment duration, darkening of the circulating fluid, biofilm formation and a sulfurous smell were observed in the biologically active column whereas no such color change (or smell) was observed for the control column. In the active column electrodic potential readings approached 570 mV whereas stable and small electrodic potential values (~8 mV) were detected in the control column.. Self potential signals were consistently only 1-8 mV in both columns. The experiment shows although electrodic potentials (at the electrode) are diagnostic of microbial driven sulfate reduction there is no measurable self potential (geobattery) effect associated with this microbial process.

  3. 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

    ... 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: Electric... for the proposed Standards of Performance for Greenhouse Gas Emissions for New Stationary...

  4. 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,…

  5. 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,…

  6. Wind power as an electrical energy source in Illinois

    NASA Astrophysics Data System (ADS)

    Wendland, W. M.

    1982-03-01

    A preliminary estimate of the total wind power available in Illinois was made using available historical data, and projections of cost savings due to the presence of wind-generated electricity were attempted. Wind data at 10 m height were considered from nine different sites in the state, with three years data nominally being included. Wind-speed frequency histograms were developed for day and night periods, using a power law function to extrapolate the 10 m readings to 20 m. Wind speeds over the whole state were found to average over 8 mph, the cut-in point for most wind turbines, for from 40-63% of the time. A maximum of 75% run-time was determined for daylight hours in April-May. A reference 1.8 kW windpowered generator was used in annual demand projections for a reference one family home, using the frequency histograms. The small generator was projected to fulfill from 25-53% of the annual load, and, based on various cost assumptions, exhibited paybacks taking from 14-27 yr.

  7. Can dependent sources be suppressed in electrical circuit theory?

    NASA Astrophysics Data System (ADS)

    Damper, Robert I.

    2011-04-01

    Can dependent sources be suppressed in circuit theory? The standard answer to this question is an unequivocal 'no'; all the reference texts agree on this point. An unpublished article by Marshall Leach challenges this received wisdom, characterising it as a 'misconception'. I have analysed Leach's work carefully and I find his method - in which dependent sources are suppressed when applying superposition - both correct and well-motivated. However, in my interpretation, the proof on which he bases his method is erroneous in one important way. This article indicates how the proof can be corrected, and improves the presentation of the method relative to Leach's by giving an example more closely related to the proof. The significant implications of this work for the teaching of circuit theory to students are discussed. Finally, a reconciliation of the two positions (which cannot both be completely right) is made, concluding that the standard method leads to correct results (as is well-known) but arguably has less claim to be called 'superposition'.

  8. Power Sources 18: Research and Development in Non-Mechanical Electrical Power Sources

    DTIC Science & Technology

    2001-04-01

    Power Sources 18 is an edited record of the papers and posters submitted for presentation at the 22nd International Power Sources Symposium that was...session concentrating on power sources for communications equipment ranging from military manpack radios to remote telemetry.

  9. 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... October 1, 1958. (b) When a compartment containing the emergency source of electric power, or vital... source of electric power, or vital components thereof, for a period of at least one hour in the event...

  10. 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... October 1, 1958. (b) When a compartment containing the emergency source of electric power, or vital... source of electric power, or vital components thereof, for a period of at least one hour in the event...

  11. 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... October 1, 1958. (b) When a compartment containing the emergency source of electric power, or vital... source of electric power, or vital components thereof, for a period of at least one hour in the event...

  12. 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... October 1, 1958. (b) When a compartment containing the emergency source of electric power, or vital... source of electric power, or vital components thereof, for a period of at least one hour in the event...

  13. 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... October 1, 1958. (b) When a compartment containing the emergency source of electric power, or vital... source of electric power, or vital components thereof, for a period of at least one hour in the event...

  14. Influence of Space Propulsions and Plasma Sources on Electric-Discharge Phenomena on the ISS

    NASA Astrophysics Data System (ADS)

    Tverdokhlebova, E. M.; Korsun, A. G.; Garkusha, V. I.; Strashinsky, V. A.; Gabdullin, F. F.; Tverdokhlebov, S. O.

    2004-10-01

    The electric field generated by the high voltage solar array of the International Space Station (ISS) induces electric discharges between constructions of the Station. The intensity of these discharges is affected by the plasma environment resulting from the activity of space propulsions and other onboard plasma sources. Parameters of the plasma environment are calculated taking into account the effect of the geomagnetic field and ionizing fluxes in space.

  15. 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.

  16. Repetitive Adjustment to Estimate the Electric Current Sources in a Nerve Fiber with Magnetic Field Measurement

    NASA Astrophysics Data System (ADS)

    Hayami, Takehito; Mishima, Yukuo; Hiwaki, Osamu

    Magnetic field measuring equipment provides us the way to examine the active position of a peripheral nerve without contact or invasion. To develop a process to estimate the position precisely, simulation study of the magnetic field induced by a myelinated nerve fiber was executed. The electric current sources around the active position of a nerve fiber can be approximated as a pair of electric current dipoles, which represent depolarization and repolarization respectively. Therefore the current sources to estimate from the detected pattern of the magnetic field were modeled as a pair of electric current dipoles. A repetitive adjustment process was proposed as an effective method to find the appropriate positions of the dipoles as the sources of the magnetic fields.

  17. On the Sourcing of Steam and Electricity for Carbon Capture Retrofits.

    PubMed

    Supekar, Sarang D; Skerlos, Steven J

    2017-10-02

    This paper compares different steam and electricity sources for carbon capture and sequestration (CCS) retrofits of pulverized coal (PC) and natural gas combined cycle (NGCC) power plants. Analytical expressions for the thermal efficiency of these power plants are derived under 16 different CCS retrofit scenarios for the purpose of illustrating their environmental and economic characteristics. The scenarios emerge from combinations of steam and electricity sources, fuel used in each source, steam generation equipment and process details, and the extent of CO2 capture. Comparing these scenarios reveals distinct trade-offs between thermal efficiency, net power output, levelized cost, profit, and net CO2 reduction. Despite causing the highest loss in useful power output, bleeding steam and extracting electric power from the main power plant to meet the CCS plant's electricity and steam demand maximizes plant efficiency and profit while minimizing emissions and levelized cost when wholesale electricity prices are below 4.5 and 5.2 US¢/kWh for PC-CCS and NGCC-CCS plants, respectively. At prices higher than these, higher profits for operating CCS retrofits can be obtained by meeting a 100% of the CCS plant's electric power demand using an auxiliary natural gas turbine-based combined heat and power plant.

  18. A procedure to estimate the electric field induced in human body exposed to unknown magnetic sources.

    PubMed

    Wang, Wencui; Bottauscio, Oriano; Chiampi, Mario; Giordano, Domenico; Zilberti, Luca

    2013-04-01

    The paper proposes and discusses a boundary element procedure able to predict the distribution of the electric field induced in a human body exposed to a low-frequency magnetic field produced by unknown sources. As a first step, the magnetic field on the body surface is reconstructed starting from the magnetic field values detected on a closed surface enclosing the sources. Then, the solution of a boundary value problem provides the electric field distribution inside the human model. The procedure is tested and validated by considering different non-uniform magnetic field distributions generated by a Helmholtz coil system as well as different locations of the human model.

  19. Characteristics of electricity generation with intermittent sources depending on the time resolution of the input data

    NASA Astrophysics Data System (ADS)

    Wagner, F.; Wertz, F.

    2016-08-01

    Data on the electricity supply with intermittent renewable sources are made public by the Transmission System Operators (TSO) and other sources. Data are typically provided in 1h increments. In this paper, we analyse wind and photo-voltaic data from the Czech Republic. The analysis concentrates on major characteristics of a supply situation where the annual demand is formally met by scaled-up wind and photovoltaic power. The original data are supplied in 1min increments and successively averaged up to 1h time resolution. This paper focuses on the dependence of the major supply characteristics on the time resolution of the available electricity data.

  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. 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.

  2. 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.

  3. Electricity production by intermittent renewable sources: a synthesis of French and German studies

    NASA Astrophysics Data System (ADS)

    Grand, D.; Le Brun, Ch.; Vidil, R.; Wagner, F.

    2016-09-01

    Wind and solar electricity is produced without direct CO2 emissions. However, the introduction of this electricity in the grid is delicate due to the intermittent character of its sources. Wind and solar production is characterized by multiple, strong variations in the electric power. These variations put stress on the grid where the total production of electricity must always be equal to the consumption. We present a synthesis of five studies conducted for Germany and France with different assumptions of electricity mixes, all with large shares of wind and solar power. These mixes are subjected to the dynamics of wind and solar production as recorded in 2010 (Germany), 2012 and 2013 (Germany and France). Common structural trends are exhibited when the results of simulations (instantaneous power distributions and average annual values) are expressed as a percentage of the annual reduced load to be produced by these intermittent energies. We focus on the evaluation of these trends and the resulting constraints on the grid. The results obtained make it possible to anticipate the problems brought about by a large share of renewable intermittent energies in the production of electricity. They show the need for backup production in order to complement the intermittent sources. This leads to CO2 emissions unless storage systems of large capacity are available.

  4. The integration of renewable energy sources into electric power distribution systems. Volume 1: National assessment

    SciTech Connect

    Barnes, P.R.; Van Dyke, J.W.; Tesche, F.M.; Zaininger, H.W.

    1994-06-01

    Renewable energy technologies such as photovoltaic, solar thermal electricity, and wind turbine power are environmentally beneficial sources of electric power generation. The integration of renewable energy sources into electric power distribution systems can provide additional economic benefits because of a reduction in the losses associated with transmission and distribution lines. Benefits associated with the deferment of transmission and distribution investment may also be possible for cases where there is a high correlation between peak circuit load and renewable energy electric generation, such as photovoltaic systems in the Southwest. Case studies were conducted with actual power distribution system data for seven electric utilities with the participation of those utilities. Integrating renewable energy systems into electric power distribution systems increased the value of the benefits by about 20 to 55% above central station benefits in the national regional assessment. In the case studies presented in Vol. II, the range was larger: from a few percent to near 80% for a case where costly investments were deferred. In general, additional savings of at least 10 to 20% can be expected by integrating at the distribution level. Wind energy systems were found to be economical in good wind resource regions, whereas photovoltaic systems costs are presently a factor of 2.5 too expensive under the most favorable conditions.

  5. Using an alternate light source to detect electrically singed feathers and hair in a forensic setting.

    PubMed

    Viner, Tabitha C; Kagan, Rebecca A; Johnson, Jennifer L

    2014-01-01

    Mortality due to electrical injury in wildlife may occur in the form of lightning strike or power line contact. Evidence of electrical contact may be grossly obvious, with extensive singeing, curling, and blackening of feathers, fur, or skin. Occasionally, changes may be subtle, owing to lower current or reduced conductivity, making a definitive diagnosis of electrocution more difficult. We describe the use of an alternate light source in the examination of cases of lightning strike and power line contact in wildlife, and the enhanced detection of changes due to electrical currents in the hair and feathers of affected animals. Subtle changes in the wing feathers of 12 snow geese and 1 wolf that were struck by separate lightning events were made obvious by the use of an alternate light source. Similarly, this technique can be used to strengthen the evidence for power line exposure in birds. Published by Elsevier Ireland Ltd.

  6. 46 CFR 190.05-15 - Segregation of spaces containing the emergency source of electric power.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Segregation of spaces containing the emergency source of electric power. 190.05-15 Section 190.05-15 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) OCEANOGRAPHIC RESEARCH VESSELS CONSTRUCTION AND ARRANGEMENT General Fire Protection § 190.05-15 Segregation of spaces containing the...

  7. 46 CFR 92.05-15 - Segregation of spaces containing the emergency source of electric power.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 4 2012-10-01 2012-10-01 false Segregation of spaces containing the emergency source of electric power. 92.05-15 Section 92.05-15 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CARGO AND MISCELLANEOUS VESSELS CONSTRUCTION AND ARRANGEMENT General Fire Protection § 92.05-15 Segregation of spaces containing the...

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

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 7 2013-10-01 2013-10-01 false Segregation of spaces containing the emergency source of electric power. 190.05-15 Section 190.05-15 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) OCEANOGRAPHIC RESEARCH VESSELS CONSTRUCTION AND ARRANGEMENT General Fire Protection § 190.05-15 Segregation of spaces containing the...

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

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 7 2014-10-01 2014-10-01 false Segregation of spaces containing the emergency source of electric power. 190.05-15 Section 190.05-15 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) OCEANOGRAPHIC RESEARCH VESSELS CONSTRUCTION AND ARRANGEMENT General Fire Protection § 190.05-15 Segregation of spaces containing the...

  10. Correlation coefficients between the dioxin levels in mother's milk and the distances to the nearest waste incinerator which was the largest source of dioxins from each mother's place of residence in Tokyo, Japan.

    PubMed

    Tajimi, M; Uehara, R; Watanabe, M; Oki, I; Ojima, T; Nakamura, Y

    2005-12-01

    To observe the relationship between the PCDD/F and Co-PCB levels in samples of human breast milk and nearby waste incinerators in Tokyo, Japan. Breast milk was taken from 240 mothers residing in Tokyo, Japan to measure and analyze the concentrations of polychlorinated dibenzo-p-dioxins (PCDDs; 14 congeners), polychlorinated dibenzofurans (PCDFs; 15 congeners), and coplanar polychlorinated biphenyls (Co-PCBs; 12 congeners) contained in the fat. Individual milk samples (about 50 ml) were obtained from the mothers 30 days after delivery, between the months of June and September in 1999 and 2000. A map of Tokyo was used to measure the distances between each mother's place of residence and the closest public and industrial waste incinerators. The distances to the nearest waste incinerators bore no apparent correlations with the congeners of PCDD/Fs and Co-PCBs. The distances were also uncorrelated with the mean toxic equivalent quantities (TEQs) of PCDD/Fs (the sum of PCDDs and PCDFs), Co-PCBs, and the total PCDD/Fs and Co-PCBs. Although waste incinerators were the largest source of dioxins in Japan at the time of the study, the dioxins levels of mother's milk bore no apparent relationships with the distances between the mothers' domiciles and the nearest waste incinerators. In this study, several meaningful factors were not taken into account, namely, the wind direction, the level of dioxin emitted from each incinerator, the level of environmental pollution of dioxins, and the average time the mothers stayed at home each day. A full understanding of these points awaits future studies.

  11. 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.

  12. Mission Enabling: The Plasma Sources of Electric Propulsion---challenges and prospects for the future

    NASA Astrophysics Data System (ADS)

    Foster, John

    2011-10-01

    Plasma propulsion has literally been mission enabling for a wide array of space applications ranging from satellite operational lifetime extension to multi-destination voyages to the asteroids. The success of plasma propulsion, otherwise known as electric propulsion, in many respects is owed to the development of clever plasma sources that bolster both high efficiency and long life. Incidentally, these attributes are also coveted in the broad area of plasma processing and manufacturing and thus are of general applicability from a technological standpoint. Indeed, there is significant cross-fertilization and application of such plasma sources not only in plasma processing but also in fusion as well. Here, a sampling of the plasma sources that enable the practical application of electric propulsion devices will be discussed with commentary on discharge physics, implementation, and technical challenges levied by mission requirements. Authors acknowlege the support of NASA in this work.

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

    PubMed

    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.

  14. 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.

  15. 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.

  16. Reproducibility and validity of electric source localisation with high-resolution electroencephalography.

    PubMed

    Kristeva-Feige, R; Grimm, C; Huppertz, H J; Otte, M; Schreiber, A; Jäger, D; Feige, B; Büchert, M; Hennig, J; Mergner, T; Lücking, C H

    1997-12-01

    The present study investigates the reproducibility and validity of the EEG source localisation of somatosensory evoked potentials (SEPs) using high-resolution EEG (61 scalp electrodes) and a source reconstruction on the basis of the individual brain morphology as obtained from magnetic resonance images (MRIs). The somatosensory evoked potentials (SEPs) to electrical stimulation of the right median nerve were repeatedly collected from the scalp of one healthy subject in 9 replications run on 9 different days. The source reconstruction for the 19 ms SEP component was performed by using a single moving dipole model as a source model. Two different head models were used: a spherical 3 shell model and a more realistically shaped 3 compartment model computed using the boundary element method (BEM). The source locations of the 19 ms SEP component were found to be highly reproducible using both head models: the mean standard deviation of the dipole locations was found to be 2.6 mm for the 3 shell model and 4 mm for the more realistically shaped head model. By projection into the individual MRI, the dipoles resulting from either head models were found to be located within the postcentral gyrus. The electric source locations were consistent with the maximum of the task-specific changes seen in a functional magnetic resonance imaging (fMRI) experiment when using the same somatosensory stimulation protocol.

  17. 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.

  18. Towards an ankle neuroprosthesis for hybrid robotics: Concepts and current sources for functional electrical stimulation.

    PubMed

    Casco, S; Fuster, I; Galeano, R; Moreno, J C; Pons, J L; Brunetti, F

    2017-07-01

    Hybrid rehabilitation robotics combine neuro-prosthetic devices (close-loop functional electrical stimulation systems) and traditional robotic structures and actuators to explore better therapies and promote a more efficient motor function recovery or compensation. Although hybrid robotics and ankle neuroprostheses (NPs) have been widely developed over the last years, there are just few studies on the use of NPs to electrically control both ankle flexion and extension to promote ankle recovery and improved gait patterns in paretic limbs. The aim of this work is to develop an ankle NP specifically designed to work in the field of hybrid robotics. This article presents early steps towards this goal and makes a brief review about motor NPs and Functional Electrical Stimulation (FES) principles and most common devices used to aid the ankle functioning during the gait cycle. It also shows a current sources analysis done in this framework, in order to choose the best one for this intended application.

  19. 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.

  20. A power-adjustable superconducting terahertz source utilizing electrical triggering phase transitions in vanadium dioxide

    NASA Astrophysics Data System (ADS)

    Hao, L. Y.; Zhou, X. J.; Yang, Z. B.; Zhang, H. L.; Sun, H. C.; Cao, H. X.; Dai, P. H.; Li, J.; Hatano, T.; Wang, H. B.; Wen, Q. Y.; Wu, P. H.

    2016-12-01

    We report a practical superconducting terahertz (THz) source, comprising a stack of Bi2Sr2CaCu2O8 intrinsic Josephson junctions (IJJs) and a vanadium dioxide (VO2) tunable attenuator with coplanar interdigital contacts. The electrical triggering phase transitions are observed not only at room temperature, but also at low temperatures, which provides a proof of the electrical triggering. Applying this, the VO2 attenuator is implemented for the independent regulations on the emission powers from the IJJ THz emitter, remaining frequencies and temperatures unchanged. The attenuation can be tuned smoothly and continuously within a couple of volts among which the maximum is, respectively, -5.6 dB at 20 K or -4.3 dB at 25 K. Such a power-adjustable radiation source, including the VO2 attenuator, can further expand its practicability in cryogenic THz systems, like superconducting THz spectrometers.

  1. Fuel cell/battery passive hybrid power source for electric powertrains

    NASA Astrophysics Data System (ADS)

    Bernard, Jérôme; Hofer, Marcel; Hannesen, Uwe; Toth, Antoine; Tsukada, Akinori; Büchi, Félix N.; Dietrich, Philipp

    The concept of passive hybrid, i.e. the direct electrical coupling between a fuel cell system and a battery without using a power converter, is presented as a feasible solution for powertrain applications. As there are no DC/DC converters, the passive hybrid is a cheap and simple solution and the power losses in the electronic hardware are eliminated. In such a powertrain topology where the two devices always have the same voltage, the active power sharing between the two energy sources can not be done in the conventional way. As an alternative, control of the fuel cell power by adjusting its operating pressure is elaborated. Only pure H 2/O 2 fuel cell systems are considered in this approach. Simulation and hardware in the loop (HIL) results for the powertrain show that this hybrid power source is able to satisfy the power demand of an electric vehicle while sustaining the battery state of charge.

  2. 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.

  3. Current source enhancements in Electrical Impedance Spectroscopy (EIS) to cancel unwanted capacitive effects

    NASA Astrophysics Data System (ADS)

    Zarafshani, Ali; Bach, Thomas; Chatwin, Chris; Xiang, Liangzhong; Zheng, Bin

    2017-03-01

    Electrical Impedance Spectroscopy (EIS) has emerged as a non-invasive imaging modality to detect and quantify functional or electrical properties related to the suspicious tumors in cancer screening, diagnosis and prognosis assessment. A constraint on EIS systems is that the current excitation system suffers from the effects of stray capacitance having a major impact on the hardware subsystem as the EIS is an ill-posed inverse problem which depends on the noise level in EIS measured data and regularization parameter in the reconstruction algorithm. There is high complexity in the design of stable current sources, with stray capacitance reducing the output impedance and bandwidth of the system. To confront this, we have designed an EIS current source which eliminates the effect of stray capacitance and other impacts of the capacitance via a variable inductance. In this paper, we present a combination of operational CCII based on a generalized impedance converter (OCCII-GIC) with a current source. The aim of this study is to use the EIS system as a biomedical imaging technique, which is effective in the early detection of breast cancer. This article begins with the theoretical description of the EIS structure, current source topologies and proposes a current conveyor in application of a Gyrator to eliminate the current source limitations and its development followed by simulation and experimental results. We demonstrated that the new design could achieve a high output impedance over a 3MHz frequency bandwidth when compared to other types of GIC circuits combined with an improved Howland topology.

  4. Effect of an electric field on superfluid helium scintillation produced by α-particle sources

    NASA Astrophysics Data System (ADS)

    Ito, T. M.; Clayton, S. M.; Ramsey, J.; Karcz, M.; Liu, C.-Y.; Long, J. C.; Reddy, T. G.; Seidel, G. M.

    2012-04-01

    We report a study of the intensity and time dependence of scintillation produced by weak α-particle sources in superfluid helium in the presence of an electric field (0-45 kV/cm) in the temperature range of 0.2 to 1.1 K at the saturated vapor pressure. Both the prompt and the delayed components of the scintillation exhibit a reduction in intensity with the application of an electric field. The reduction in the intensity of the prompt component is well approximated by a linear dependence on the electric field strength with a reduction of 15% at 45 kV/cm. When analyzed using the Kramers theory of columnar recombination, this electric field dependence leads to the conclusion that roughly 40% of the scintillation results from species formed from atoms originally promoted to excited states and 60% from excimers created by ionization and subsequent recombination with the charges initially having a cylindrical Gaussian distribution about the α track of 60 nm radius. The intensity of the delayed component of the scintillation has a stronger dependence on the electric field strength and on temperature. The implications of these data on the mechanisms affecting scintillation in liquid helium are discussed.

  5. 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.

  6. 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

  7. 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.

  8. 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.

  9. 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.

  10. Theoretical and computational methods for the noninvasive detection of gastric electrical source coupling

    NASA Astrophysics Data System (ADS)

    Irimia, Andrei; Bradshaw, L. Alan

    2004-05-01

    The ability to study the pathology of the stomach noninvasively from magnetic field measurements is important due to the significant practical advantages offered by noninvasive methods over other techniques of investigation. The inverse biomagnetic problem can play a central role in this process due to the information that inverse solutions can yield concerning the characteristics of the gastric electrical activity (GEA). To analyze gastrointestinal (GI) magnetic fields noninvasively, we have developed a computer implementation of a least-squares minimization algorithm that obtains numerical solutions to the biomagnetic inverse problem for the stomach. In this paper, we show how electric current propagation and the mechanical coupling of gastric smooth muscle cells during electrical control activity can be studied using such solutions. To validate our model, two types of numerical simulations of the GEA were developed and successfully used to demonstrate the ability of our computer algorithm to detect and accurately analyze these two phenomena. We also describe our analysis of experimental, noninvasively acquired gastric biomagnetic data as well as the information of interest that our numerical method can yield in clinical studies. Most importantly, we present experimental evidence that the coupling of gastric electrical sources can be observed using noninvasive techniques of measurement, in our case with the use of a superconducting quantum interference device magnetometer. We discuss the relevance and implications of our achievement to the future of GI research.

  11. 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.

  12. 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.

  13. Meeting China's electricity needs through clean energy sources: A 2030 low-carbon energy roadmap

    NASA Astrophysics Data System (ADS)

    Hu, Zheng

    China is undergoing rapid economic development that generates significant increase in energy demand, primarily for electricity. Energy supply in China is heavily relying on coal, which leads to high carbon emissions. This dissertation explores opportunities for meeting China's growing power demand through clean energy sources. The utilization of China's clean energy sources as well as demand-side management is still at the initial phase. Therefore, development of clean energy sources would require substantial government support in order to be competitive in the market. One of the widely used means to consider clean energy in power sector supplying is Integrated Resource Strategic Planning, which aims to minimize the long term electricity costs while screening various power supply options for the power supply and demand analysis. The IRSP tool tackles the energy problem from the perspective of power sector regulators, and provides different policy scenarios to quantify the impacts of combined incentives. Through three scenario studies, Business as Usual, High Renewable, and Renewable and Demand Side Management, this dissertation identifies the optimized scenario for China to achieve the clean energy target of 2030. The scenarios are assessed through energy, economics, environment, and equity dimensions.

  14. 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.

  15. The direct-current response of electrically conducting fractures excited by a grounded current source

    SciTech Connect

    Weiss, Chester J.; Aldridge, David F.; Knox, Hunter A.; Schramm, Kimberly A.; Bartel, Lewis C.

    2016-05-01

    Hydraulic fracture stimulation of low permeability reservoir rocks is an established and cross–cutting technology for enhancing hydrocarbon production in sedimentary formations and increasing heat exchange in crystalline geothermal systems. Whereas the primary measure of success is the ability to keep the newly generated fractures sufficiently open, long–term reservoir management requires a knowledge of the spatial extent, morphology, and distribution of the fractures — knowledge primarily informed by microseismic and ground deformation monitoring. To minimize the uncertainty associated with interpreting such data, we investigate through numerical simulation the usefulness of direct-current (DC) resistivity data for characterizing subsurface fractures with elevated electrical conductivity by considering a geophysical experiment consisting of a grounded current source deployed in a steel cased borehole. In doing so, the casing efficiently energizes the fractures with steady current. Finite element simulations of this experiment for a horizontal well intersecting a small set of vertical fractures indicate that the fractures manifest electrically in (at least) two ways: (1) a local perturbation in electric potential proximal to the fracture set, with limited farfield expression and (2) an overall reduction in the electric potential along the borehole casing due to enhanced current flow through the fractures into the surrounding formation. The change in casing potential results in a measurable effect that can be observed far from fractures themselves. Under these conditions, our results suggest that farfield, timelapse measurements of DC potentials can be interpreted by simple, linear inversion for a Coulomb charge distribution along the borehole path, including a local charge perturbation due to the fractures. As a result, this approach offers an inexpensive method for detecting and monitoring the time-evolution of electrically conducting fractures while

  16. The direct-current response of electrically conducting fractures excited by a grounded current source

    SciTech Connect

    Weiss, Chester J.; Aldridge, David F.; Knox, Hunter A.; Schramm, Kimberly A.; Bartel, Lewis C.

    2016-05-01

    Hydraulic fracture stimulation of low permeability reservoir rocks is an established and cross–cutting technology for enhancing hydrocarbon production in sedimentary formations and increasing heat exchange in crystalline geothermal systems. Whereas the primary measure of success is the ability to keep the newly generated fractures sufficiently open, long–term reservoir management requires a knowledge of the spatial extent, morphology, and distribution of the fractures — knowledge primarily informed by microseismic and ground deformation monitoring. To minimize the uncertainty associated with interpreting such data, we investigate through numerical simulation the usefulness of direct-current (DC) resistivity data for characterizing subsurface fractures with elevated electrical conductivity by considering a geophysical experiment consisting of a grounded current source deployed in a steel cased borehole. In doing so, the casing efficiently energizes the fractures with steady current. Finite element simulations of this experiment for a horizontal well intersecting a small set of vertical fractures indicate that the fractures manifest electrically in (at least) two ways: (1) a local perturbation in electric potential proximal to the fracture set, with limited farfield expression and (2) an overall reduction in the electric potential along the borehole casing due to enhanced current flow through the fractures into the surrounding formation. The change in casing potential results in a measurable effect that can be observed far from fractures themselves. Under these conditions, our results suggest that farfield, timelapse measurements of DC potentials can be interpreted by simple, linear inversion for a Coulomb charge distribution along the borehole path, including a local charge perturbation due to the fractures. As a result, this approach offers an inexpensive method for detecting and monitoring the time-evolution of electrically conducting fractures while

  17. 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)

  18. Electricity

    SciTech Connect

    Sims, B.

    1983-01-01

    Historical aspects of electricity are reviewed with individual articles on hydroelectric dams, coal-burning power plants, nuclear power plants, electricity distribution, and the energy future. A glossary is included. (PSB)

  19. Fully integrated quantum photonic circuit with an electrically driven light source

    NASA Astrophysics Data System (ADS)

    Khasminskaya, Svetlana; Pyatkov, Felix; Słowik, Karolina; Ferrari, Simone; Kahl, Oliver; Kovalyuk, Vadim; Rath, Patrik; Vetter, Andreas; Hennrich, Frank; Kappes, Manfred M.; Gol'Tsman, G.; Korneev, A.; Rockstuhl, Carsten; Krupke, Ralph; Pernice, Wolfram H. P.

    2016-11-01

    Photonic quantum technologies allow quantum phenomena to be exploited in applications such as quantum cryptography, quantum simulation and quantum computation. A key requirement for practical devices is the scalable integration of single-photon sources, detectors and linear optical elements on a common platform. Nanophotonic circuits enable the realization of complex linear optical systems, while non-classical light can be measured with waveguide-integrated detectors. However, reproducible single-photon sources with high brightness and compatibility with photonic devices remain elusive for fully integrated systems. Here, we report the observation of antibunching in the light emitted from an electrically driven carbon nanotube embedded within a photonic quantum circuit. Non-classical light generated on chip is recorded under cryogenic conditions with waveguide-integrated superconducting single-photon detectors, without requiring optical filtering. Because exclusively scalable fabrication and deposition methods are used, our results establish carbon nanotubes as promising nanoscale single-photon emitters for hybrid quantum photonic devices.

  20. 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.

  1. 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

  2. Anthracite firing -- Largest steam generators

    SciTech Connect

    Brower, P.; Winkin, J.; Changqin, G.

    1998-07-01

    The size and scope of the Hanfeng Power Plant is a large undertaking by any definition. It is progressing very well with good coordination and cooperation of all those involved. Start-up is scheduled for the first unit in the year 2000 with the second unit following by eight months. The boiler island scope covers all equipment and structural steel from the bunkers to the stack. This includes the world's two largest anthracite fired boilers burning a blend of very low volatile Chinese anthracite and lean coal (bituminous). The coal blending is designed to maximize the use of the local anthracite coal. This is done by controlled blending at the entrance to the large FW D12D ball mills. Scaling up from earlier extensive experience with arch fired boilers is reviewed as well as key features of the Hanfeng boilers each of which are capable of generating 563 kg/s of steam at 540.8 C and 175 bar (equivalent to 717 MW of turbine/generator output). The design of the boiler and related equipment for the Hanfeng project has been the subject of in-depth reviews by independent engineers representing the banks to assure reliability of the boiler to support the economic model. It has been shown that FW's extensive experience burning anthracite coals has justified the scaling up of the various components to meet the requirements of the specification. This experience is based on operating similar type anthracite arch fired boilers with fuel blends that are comparable to the coals to be supplied for the Hanfeng project. The materials and equipment for the Hanfeng boiler island are being supplied on a multi-national basis in support of the various requirements of the financing institutions involved. The overall design has been finalized and the detail design is well underway. Most of the large critical components are already in manufacturing.

  3. 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.

  4. 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

  5. Direct mapping of electrical noise sources in molecular wire-based devices

    NASA Astrophysics Data System (ADS)

    Cho, Duckhyung; Lee, Hyungwoo; Shekhar, Shashank; Yang, Myungjae; Park, Jae Yeol; Hong, Seunghun

    2017-02-01

    We report a noise mapping strategy for the reliable identification and analysis of noise sources in molecular wire junctions. Here, different molecular wires were patterned on a gold substrate, and the current-noise map on the pattern was measured and analyzed, enabling the quantitative study of noise sources in the patterned molecular wires. The frequency spectra of the noise from the molecular wire junctions exhibited characteristic 1/f2 behavior, which was used to identify the electrical signals from molecular wires. This method was applied to analyze the molecular junctions comprising various thiol molecules on a gold substrate, revealing that the noise in the junctions mainly came from the fluctuation of the thiol bonds. Furthermore, we quantitatively compared the frequencies of such bond fluctuations in different molecular wire junctions and identified molecular wires with lower electrical noise, which can provide critical information for designing low-noise molecular electronic devices. Our method provides valuable insights regarding noise phenomena in molecular wires and can be a powerful tool for the development of molecular electronic devices.

  6. Direct mapping of electrical noise sources in molecular wire-based devices

    PubMed Central

    Cho, Duckhyung; Lee, Hyungwoo; Shekhar, Shashank; Yang, Myungjae; Park, Jae Yeol; Hong, Seunghun

    2017-01-01

    We report a noise mapping strategy for the reliable identification and analysis of noise sources in molecular wire junctions. Here, different molecular wires were patterned on a gold substrate, and the current-noise map on the pattern was measured and analyzed, enabling the quantitative study of noise sources in the patterned molecular wires. The frequency spectra of the noise from the molecular wire junctions exhibited characteristic 1/f2 behavior, which was used to identify the electrical signals from molecular wires. This method was applied to analyze the molecular junctions comprising various thiol molecules on a gold substrate, revealing that the noise in the junctions mainly came from the fluctuation of the thiol bonds. Furthermore, we quantitatively compared the frequencies of such bond fluctuations in different molecular wire junctions and identified molecular wires with lower electrical noise, which can provide critical information for designing low-noise molecular electronic devices. Our method provides valuable insights regarding noise phenomena in molecular wires and can be a powerful tool for the development of molecular electronic devices. PMID:28233821

  7. Electricity generation from wastewaters with starch as carbon source using a mediatorless microbial fuel cell.

    PubMed

    Herrero-Hernandez, E; Smith, T J; Akid, R

    2013-01-15

    Microbial fuel cells represent a new method for producing electricity from the oxidation of organic matter. A mediatorless microbial fuel cell was developed using Escherichia coli as the active bacterial component with synthetic wastewater of potato extract as the energy source. The two-chamber fuel cell, with a relation of volume between anode and cathode chamber of 8:1, was operated in batch mode. The response was similar to that obtained when glucose was used as the carbon source. The performance characteristics of the fuel cell were evaluated with two different anode and cathode shapes, platinised titanium strip or mesh; the highest maximum power density (502mWm(-2)) was achieved in the microbial fuel cell with mesh electrodes. In addition to electricity generation, the MFC exhibited efficient treatment of wastewater so that significant reduction of initial oxygen demand of wastewater by 61% was observed. These results demonstrate that potato starch can be used for power generation in a mediatorless microbial fuel cell with high removal efficiency of chemical oxygen demand.

  8. 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.

  9. Neutron source strength measurements for Varian, Siemens, Elekta, and General Electric linear accelerators.

    PubMed

    Followill, David S; Stovall, Marilyn S; Kry, Stephen F; Ibbott, Geoffrey S

    2003-01-01

    The shielding calculations for high energy (>10 MV) linear accelerators must include the photoneutron production within the head of the accelerator. Procedures have been described to calculate the treatment room door shielding based on the neutron source strength (Q value) for a specific accelerator and energy combination. Unfortunately, there is currently little data in the literature stating the neutron source strengths for the most widely used linear accelerators. In this study, the neutron fluence for 36 linear accelerators, including models from Varian, Siemens, Elekta/Philips, and General Electric, was measured using gold-foil activation. Several of the models and energy combinations had multiple measurements. The neutron fluence measured in the patient plane was independent of the surface area of the room, suggesting that neutron fluence is more dependent on the direct neutron fluence from the head of the accelerator than from room scatter. Neutron source strength, Q, was determined from the measured neutron fluences. As expected, Q increased with increasing photon energy. The Q values ranged from 0.02 for a 10 MV beam to 1.44(x10(12)) neutrons per photon Gy for a 25 MV beam. The most comprehensive set of neutron source strength values, Q, for the current accelerators in clinical use are presented for use in calculating room shielding.

  10. 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.

  11. The direct-current response of electrically conducting fractures excited by a grounded current source

    DOE PAGES

    Weiss, Chester J.; Aldridge, David F.; Knox, Hunter A.; ...

    2016-05-01

    Hydraulic fracture stimulation of low permeability reservoir rocks is an established and cross–cutting technology for enhancing hydrocarbon production in sedimentary formations and increasing heat exchange in crystalline geothermal systems. Whereas the primary measure of success is the ability to keep the newly generated fractures sufficiently open, long–term reservoir management requires a knowledge of the spatial extent, morphology, and distribution of the fractures — knowledge primarily informed by microseismic and ground deformation monitoring. To minimize the uncertainty associated with interpreting such data, we investigate through numerical simulation the usefulness of direct-current (DC) resistivity data for characterizing subsurface fractures with elevated electricalmore » conductivity by considering a geophysical experiment consisting of a grounded current source deployed in a steel cased borehole. In doing so, the casing efficiently energizes the fractures with steady current. Finite element simulations of this experiment for a horizontal well intersecting a small set of vertical fractures indicate that the fractures manifest electrically in (at least) two ways: (1) a local perturbation in electric potential proximal to the fracture set, with limited farfield expression and (2) an overall reduction in the electric potential along the borehole casing due to enhanced current flow through the fractures into the surrounding formation. The change in casing potential results in a measurable effect that can be observed far from fractures themselves. Under these conditions, our results suggest that farfield, timelapse measurements of DC potentials can be interpreted by simple, linear inversion for a Coulomb charge distribution along the borehole path, including a local charge perturbation due to the fractures. As a result, this approach offers an inexpensive method for detecting and monitoring the time-evolution of electrically conducting fractures while

  12. Experimental Verification of Isotropic Radiation from a Coherent Dipole Source via Electric-Field-Driven LC Resonator Metamaterials

    NASA Astrophysics Data System (ADS)

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

    2013-09-01

    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.

  13. 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.

  14. Three-dimensional forward modeling and inversion of borehole-to-surface electrical imaging with different power sources

    NASA Astrophysics Data System (ADS)

    Bai, Ze; Tan, Mao-Jin; Zhang, Fu-Lai

    2016-09-01

    Borehole-to-surface electrical imaging (BSEI) uses a line source and a point source to generate a stable electric field in the ground. In order to study the surface potential of anomalies, three-dimensional forward modeling of point and line sources was conducted by using the finite-difference method and the incomplete Cholesky conjugate gradient (ICCG) method. Then, the damping least square method was used in the 3D inversion of the formation resistivity data. Several geological models were considered in the forward modeling and inversion. The forward modeling results suggest that the potentials generated by the two sources have different surface signatures. The inversion data suggest that the low-resistivity anomaly is outlined better than the high-resistivity anomaly. Moreover, when the point source is under the anomaly, the resistivity anomaly boundaries are better outlined than when using a line source.

  15. 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.

  16. 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

  17. 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

  18. 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

  19. 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.

  20. 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.

  1. 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.

  2. Evaluating four-dimensional time-lapse electrical resistivity tomography for monitoring DNAPL source zone remediation

    NASA Astrophysics Data System (ADS)

    Power, Christopher; Gerhard, Jason I.; Karaoulis, Marios; Tsourlos, Panagiotis; Giannopoulos, Antonios

    2014-07-01

    Practical, non-invasive tools do not currently exist for mapping the remediation of dense non-aqueous phase liquids (DNAPLs). Electrical resistivity tomography (ERT) exhibits significant potential but has not yet become a practitioner's tool due to challenges in interpreting the survey results at real sites. This study explores the effectiveness of recently developed four-dimensional (4D, i.e., 3D space plus time) time-lapse surface ERT to monitor DNAPL source zone remediation. A laboratory experiment demonstrated the approach for mapping a changing NAPL distribution over time. A recently developed DNAPL-ERT numerical model was then employed to independently simulate the experiment, providing confidence that the DNAPL-ERT model is a reliable tool for simulating real systems. The numerical model was then used to evaluate the potential for this approach at the field scale. Four DNAPL source zones, exhibiting a range of complexity, were initially simulated, followed by modeled time-lapse ERT monitoring of complete DNAPL remediation by enhanced dissolution. 4D ERT inversion provided estimates of the regions of the source zone experiencing mass reduction with time. Results show that 4D time-lapse ERT has significant potential to map both the outline and the center of mass of the evolving treated portion of the source zone to within a few meters in each direction. In addition, the technique can provide a reasonable, albeit conservative, estimate of the DNAPL volume remediated with time: 25% underestimation in the upper 2 m and up to 50% underestimation at late time between 2 and 4 m depth. The technique is less reliable for identifying cleanup of DNAPL stringers outside the main DNAPL body. Overall, this study demonstrates that 4D time-lapse ERT has potential for mapping where and how quickly DNAPL mass changes in real time during site remediation.

  3. Evaluating four-dimensional time-lapse electrical resistivity tomography for monitoring DNAPL source zone remediation.

    PubMed

    Power, Christopher; Gerhard, Jason I; Karaoulis, Marios; Tsourlos, Panagiotis; Giannopoulos, Antonios

    2014-07-01

    Practical, non-invasive tools do not currently exist for mapping the remediation of dense non-aqueous phase liquids (DNAPLs). Electrical resistivity tomography (ERT) exhibits significant potential but has not yet become a practitioner's tool due to challenges in interpreting the survey results at real sites. This study explores the effectiveness of recently developed four-dimensional (4D, i.e., 3D space plus time) time-lapse surface ERT to monitor DNAPL source zone remediation. A laboratory experiment demonstrated the approach for mapping a changing NAPL distribution over time. A recently developed DNAPL-ERT numerical model was then employed to independently simulate the experiment, providing confidence that the DNAPL-ERT model is a reliable tool for simulating real systems. The numerical model was then used to evaluate the potential for this approach at the field scale. Four DNAPL source zones, exhibiting a range of complexity, were initially simulated, followed by modeled time-lapse ERT monitoring of complete DNAPL remediation by enhanced dissolution. 4D ERT inversion provided estimates of the regions of the source zone experiencing mass reduction with time. Results show that 4D time-lapse ERT has significant potential to map both the outline and the center of mass of the evolving treated portion of the source zone to within a few meters in each direction. In addition, the technique can provide a reasonable, albeit conservative, estimate of the DNAPL volume remediated with time: 25% underestimation in the upper 2m and up to 50% underestimation at late time between 2 and 4m depth. The technique is less reliable for identifying cleanup of DNAPL stringers outside the main DNAPL body. Overall, this study demonstrates that 4D time-lapse ERT has potential for mapping where and how quickly DNAPL mass changes in real time during site remediation. Copyright © 2014 Elsevier B.V. All rights reserved.

  4. 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

  5. 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.

  6. 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

  7. 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

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

    PubMed

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

    2013-08-01

    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. 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. 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. 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 facilities. Such evidence about electricity needs and gaps would

  9. 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

  10. 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

  11. Electrically-activated source extension graphene nanoribbon field effect transistor: Novel attributes and design considerations for suppressing short channel effects

    NASA Astrophysics Data System (ADS)

    Naderi, Ali; Keshavarzi, Parviz

    2014-08-01

    In this paper a double gate graphene nanoribbon field effect transistor with electrically-activated source extension is proposed. Source region of the proposed structure includes two sections, an electrically-activated extension and a doped section. The electrically extension, which is located between doped source section and gate region, is biased independent of the gate to form a virtual extension for source. The electrically-activated extension creates a step in potential profile which increases the horizontal distance between conduction and valance bands at channel to source junction. This step reduces the probability of band to band tunneling, lowers the leakage current and improves drain induced barrier lowering. The devices have been simulated based on self consistent solution of Poisson and Schrodinger equations within non-equilibrium Green's function formalism. In addition, the effects of the edge and third nearest neighbor are included for more accurate outcomes. Simulations show that the proposed structure is a more reliable device because of its higher ON/Off current ratio, shorter delay time, and smaller power delay product beside lower subthreshold swing than conventional graphene nanoribbon field effect transistor.

  12. 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

  13. An Electricity Price-Aware Open-Source Smart Socket for the Internet of Energy

    PubMed Central

    Blanco-Novoa, Óscar; Fernández-Caramés, Tiago M.; Fraga-Lamas, Paula; Castedo, Luis

    2017-01-01

    The Internet of Energy (IoE) represents a novel paradigm where electrical power systems work cooperatively with smart devices to increase the visibility of energy consumption and create safer, cleaner and sustainable energy systems. The implementation of IoE services involves the use of multiple components, like embedded systems, power electronics or sensors, which are an essential part of the infrastructure dedicated to the generation and distribution energy and the one required by the final consumer. This article focuses on the latter and presents a smart socket system that collects the information about energy price and makes use of sensors and actuators to optimize home energy consumption according to the user preferences. Specifically, this article provides three main novel contributions. First, what to our knowledge is the first hardware prototype that manages in a practical real-world scenario the price values obtained from a public electricity operator is presented. The second contribution is related to the definition of a novel wireless sensor network communications protocol based on Wi-Fi that allows for creating an easy-to-deploy smart plug system that self-organizes and auto-configures to collect the sensed data, minimizing user intervention. Third, it is provided a thorough description of the design of one of the few open-source smart plug systems, including its communications architecture, the protocols implemented, the main sensing and actuation components and the most relevant pieces of the software. Moreover, with the aim of illustrating the capabilities of the smart plug system, the results of different experiments performed are shown. Such experiments evaluate in real-world scenarios the system’s ease of use, its communications range and its performance when using HTTPS. Finally, the economic savings are estimated for different appliances, concluding that, in the practical situation proposed, the smart plug system allows certain energy

  14. An Electricity Price-Aware Open-Source Smart Socket for the Internet of Energy.

    PubMed

    Blanco-Novoa, Óscar; Fernández-Caramés, Tiago M; Fraga-Lamas, Paula; Castedo, Luis

    2017-03-21

    The Internet of Energy (IoE) represents a novel paradigm where electrical power systems work cooperatively with smart devices to increase the visibility of energy consumption and create safer, cleaner and sustainable energy systems. The implementation of IoE services involves the use of multiple components, like embedded systems, power electronics or sensors, which are an essential part of the infrastructure dedicated to the generation and distribution energy and the one required by the final consumer. This article focuses on the latter and presents a smart socket system that collects the information about energy price and makes use of sensors and actuators to optimize home energy consumption according to the user preferences. Specifically, this article provides three main novel contributions. First, what to our knowledge is the first hardware prototype that manages in a practical real-world scenario the price values obtained from a public electricity operator is presented. The second contribution is related to the definition of a novel wireless sensor network communications protocol based on Wi-Fi that allows for creating an easy-to-deploy smart plug system that self-organizes and auto-configures to collect the sensed data, minimizing user intervention. Third, it is provided a thorough description of the design of one of the few open-source smart plug systems, including its communications architecture, the protocols implemented, the main sensing and actuation components and the most relevant pieces of the software. Moreover, with the aim of illustrating the capabilities of the smart plug system, the results of different experiments performed are shown. Such experiments evaluate in real-world scenarios the system's ease of use, its communications range and its performance when using HTTPS. Finally, the economic savings are estimated for different appliances, concluding that, in the practical situation proposed, the smart plug system allows certain energy

  15. 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.

  16. Spatial correlation of hemodynamic changes related to interictal epileptic discharges with electric and magnetic source imaging.

    PubMed

    Heers, Marcel; Hedrich, Tanguy; An, Dongmei; Dubeau, François; Gotman, Jean; Grova, Christophe; Kobayashi, Eliane

    2014-09-01

    Blood oxygenation level-dependent (BOLD) signal changes at the time of interictal epileptic discharges (IEDs) identify their associated vascular/hemodynamic responses. BOLD activations and deactivations can be found within the epileptogenic zone but also at a distance. Source imaging identifies electric (ESI) and magnetic (MSI) sources of IEDs, with the advantage of a higher temporal resolution. Therefore, the objective of our study was to evaluate the spatial concordance between ESI/MSI and BOLD responses for similar IEDs. Twenty-one patients with similar IEDs in simultaneous electroencephalogram/functional magnetic resonance imaging (EEG/fMRI) and in simultaneous EEG/magnetoencephalogram (MEG) recordings were studied. IEDs in EEG/fMRI acquisition were analyzed in an event-related paradigm within a general linear model (GLM). ESI/MSI of averaged IEDs was performed using the Maximum Entropy on the Mean. We assessed the spatial concordance between ESI/MSI and clusters of BOLD activations/deactivations with surface-based metrics. ESI/MSI were concordant with one BOLD cluster for 20/21 patients (concordance with activation: 14/21 patients, deactivation: 6/21 patients, no concordance: 1/21 patients; concordance with MSI only: 3/21, ESI only: 2/21). These BOLD clusters exhibited in 19/20 cases the most significant voxel. BOLD clusters that were spatially concordant with ESI/MSI were concordant with IEDs from invasive recordings in 8/11 patients (activations: 5/8, deactivations: 3/8). As the results of BOLD, ESI and MSI are often concordant, they reinforce our confidence in all of them. ESI and MSI confirm the most significant BOLD cluster within BOLD maps, emphasizing the importance of these clusters for the definition of the epileptic focus. Copyright © 2014 Wiley Periodicals, Inc.

  17. 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.

  18. The effect of a source-contacted light shield on the electrical characteristics of an LTPS TFT

    NASA Astrophysics Data System (ADS)

    Kim, Miryeon; Sun, Wookyung; Kang, Jongseuk; Shin, Hyungsoon

    2017-08-01

    The electrical characteristics of a low-temperature polycrystalline silicon thin-film transistor (TFT) with a source-contacted light shield (SCLS) are observed and analyzed. Compared with that of a conventional TFT without a light shield (LS), the on-current of the TFT with an SCLS is lower because the SCLS blocks the fringing electric field from the drain to the active layer. Furthermore, the gate-to-source capacitance (C gs) of the TFT with an SCLS in the off and saturation regions is higher than that of a conventional TFT, which is due to the gate-to-LS capacitance (C g-LS). The electrical characteristics of the TFT with an SCLS are thoroughly investigated by two-dimensional device simulations, and a semi-empirical C g-LS model for SPICE simulation is proposed and verified.

  19. Dynamic Electrical Source Imaging (DESI) of Seizures and Interictal Epileptic Discharges Without Ensemble Averaging

    PubMed Central

    Erem, Burak; Hyde, Damon E.; Peters, Jurriaan M.; Duffy, Frank H.; Warfield, Simon K.

    2016-01-01

    We propose an algorithm for electrical source imaging of epileptic discharges that takes a data-driven approach to regularizing the dynamics of solutions. The method is based on linear system identification on short time segments, combined with a classical inverse solution approach. Whereas ensemble averaging of segments or epochs discards inter-segment variations by averaging across them, our approach explicitly models them. Indeed, it may even be possible to avoid the need for the time-consuming process of marking epochs containing discharges altogether. We demonstrate that this approach can produce both stable and accurate inverse solutions in experiments using simulated data and real data from epilepsy patients. In an illustrative example, we show that we are able to image propagation using this approach. We show that when applied to imaging seizure data, our approach reproducibly localized frequent seizure activity to within the margins of surgeries that led to patients’ seizure freedom. The same approach could be used in the planning of epilepsy surgeries, as a way to localize potentially epileptogenic tissue that should be resected. PMID:27479957

  20. 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.

  1. Measurement cells of the Spallation Neutron Source neutron Electric Dipole Moment experiment

    NASA Astrophysics Data System (ADS)

    Leung, Kent; SNS nEDM Collaboration

    2016-09-01

    The Spallation Neutron Source (SNS) neutron Electric Dipole Moment (nEDM) experiment will use 3 L rectangular measurement cells filled with superfluid helium at 0.3 - 0.5 K with a 10-10 fraction of polarized 3He. These cells are made from 0.5 in thick PMMA plates, coated with a mixture of deuterated polystyrene and deuterated tetraphenyl butadiene and then glued together with deuterated acrylic cement. The experiment requires the cells to be: non-magnetic, non-conducting, fluorescent at the inner surface for VUV photons, optically transparent, cryogenic-friendly, polarized 3He friendly, and have long ultracold neutron (UCN) storage times. The successful production of full-sized cells and how these cells address each of the above requirements, will be presented. Focus will be given on recent UCN storage tests of several cells measured between 90 K to 20 K. These results demonstrate the cryogenic robustness of these cells and UCN loss f-factors of 2 ×10-5 , better than beryllium at low temperatures. A previous problem of gaps or uncovered patches exposed on the inside of the cell has been resolved. Exploratory work on new polymer coatings that could improve our cells further will also be presented. DE-FG02-97ER41042.

  2. Risks and psychic costs of alternative energy sources for generating electricity

    SciTech Connect

    Spangler, M.B.

    1981-01-01

    Divisive personal issues will continue to impede the formulation of a coherent national energy policy until we come to grips with the disagreements and anxieties behind the issues. Variations in individual anxiety profiles and limited knowledge are the major sources of conflict. A structured approach for analyzing psychic costs in the risk-cost-benefit analyses of energy options focuses on the electric-utility industry. Coupling psychic costs with economic costs requires an understanding of how social values interact to produce either risk acceptance or risk rejection. A review of the literature shows that people experiencing a continuous anxiety state may come to value the focus of their fear as a policy issue more than on loss of life. Public reaction after the Three Mile Island accident illustrates this condition. Personal bias in risk perception is variable partly because of differences in information. Information and personal values, however, can be mutually incompatible and lead to psychic conflicts. Proponents of soft energy technology, for example, are criticized for their lack of information about the associated risks and not credited for the psychic benefits of their goals. 58 references. (DCK)

  3. Electrical source localization by LORETA in patients with epilepsy: Confirmation by postoperative MRI

    PubMed Central

    Akdeniz, Gülsüm

    2016-01-01

    Background: Few studies have been conducted that have compared electrical source localization (ESL) results obtained by analyzing ictal patterns in scalp electroencephalogram (EEG) with the brain areas that are found to be responsible for seizures using other brain imaging techniques. Additionally, adequate studies have not been performed to confirm the accuracy of ESL methods. Materials and Methods: In this study, ESL was conducted using LORETA (Low Resolution Brain Electromagnetic Tomography) in 9 patients with lesions apparent on magnetic resonance imaging (MRI) and in 6 patients who did not exhibit lesions on their MRIs. EEGs of patients who underwent surgery for epilepsy and had follow-ups for at least 1 year after operations were analyzed for ictal spike, rhythmic, paroxysmal fast, and obscured EEG activities. Epileptogenic zones identified in postoperative MRIs were then compared with localizations obtained by LORETA model we employed. Results: We found that brain areas determined via ESL were in concordance with resected brain areas for 13 of the 15 patients evaluated, and those 13 patients were post-operatively determined as being seizure-free. Conclusion: ESL, which is a noninvasive technique, may contribute to the correct delineation of epileptogenic zones in patients who will eventually undergo surgery to treat epilepsy, (regardless of neuroimaging status). Moreover, ESL may aid in deciding on the number and localization of intracranial electrodes to be used in patients who are candidates for invasive recording. PMID:27011626

  4. 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.

  5. 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

  6. Experimental study on the electric-sweep scanner and ion beam emittance of electron cyclotron resonance ion source

    SciTech Connect

    Cao, Y.; Sun, L.T.; Ma, L.; Ma, B.H.; Wang, H.; Feng, Y.C.; Li, J.Y.; Zhao, H.W.; Zhang, Z.M.; Zhang, X.Z.; He, W.; Zhao, H.Y.; Guo, X.; Li, X.X.

    2006-03-15

    With a latest developed electric-sweep scanner system, we have done a lot of experiments for studying this scanner system and ion beam emittance of electron cyclotron resonance (ECR) ion source. The electric-sweep scanner system was installed on the beam line of Lanzhou electron resonance ion source No. 3 experimental platform of Institute of Modern Physics. The repetition experiments have proven that the system is a relatively dependable and reliable emittance scanner, and its experiment error is about 10%. We have studied the influences of the major parameters of ECR ion source on the extracted ion beam emittance. The typical results of the experiments and the conclusions are presented in this article.

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

    PubMed

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

    2001-09-01

    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

  8. 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

  9. 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.

  10. 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.

  11. 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

  12. 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

  13. Source analysis of auditory steady-state responses in acoustic and electric hearing.

    PubMed

    Luke, Robert; De Vos, Astrid; Wouters, Jan

    2017-02-15

    Speech is a complex signal containing a broad variety of acoustic information. For accurate speech reception, the listener must perceive modulations over a range of envelope frequencies. Perception of these modulations is particularly important for cochlear implant (CI) users, as all commercial devices use envelope coding strategies. Prolonged deafness affects the auditory pathway. However, little is known of how cochlear implantation affects the neural processing of modulated stimuli. This study investigates and contrasts the neural processing of envelope rate modulated signals in acoustic and CI listeners. Auditory steady-state responses (ASSRs) are used to study the neural processing of amplitude modulated (AM) signals. A beamforming technique is applied to determine the increase in neural activity relative to a control condition, with particular attention paid to defining the accuracy and precision of this technique relative to other tomographies. In a cohort of 44 acoustic listeners, the location, activity and hemispheric lateralisation of ASSRs is characterised while systematically varying the modulation rate (4, 10, 20, 40 and 80Hz) and stimulation ear (right, left and bilateral). We demonstrate a complex pattern of laterality depending on both modulation rate and stimulation ear that is consistent with, and extends, existing literature. We present a novel extension to the beamforming method which facilitates source analysis of electrically evoked auditory steady-state responses (EASSRs). In a cohort of 5 right implanted unilateral CI users, the neural activity is determined for the 40Hz rate and compared to the acoustic cohort. Results indicate that CI users activate typical thalamic locations for 40Hz stimuli. However, complementary to studies of transient stimuli, the CI population has atypical hemispheric laterality, preferentially activating the contralateral hemisphere.

  14. 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

  15. Electricity use patterns in cotton gins

    USDA-ARS?s Scientific Manuscript database

    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...

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. 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

  1. Developmental changes in fact and source recall: contributions from executive function and brain electrical activity.

    PubMed

    Rajan, Vinaya; Bell, Martha Ann

    2015-04-01

    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. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

  2. 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...

  3. 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...

  4. 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,…

  5. 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,…

  6. 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.

  7. Accounting Methodology for Source Energy of Non-Combustible Renewable Electricity Generation

    SciTech Connect

    Donohoo-Vallett, Paul

    2016-10-01

    As non-combustible sources of renewable power (wind, solar, hydro, and geothermal) do not consume fuel, the “source” (or “primary”) energy from these sources cannot be accounted for in the same manner as it is for fossil fuel sources. The methodology chosen for these technologies is important as it affects the perception of the relative size of renewable source energy to fossil energy, affects estimates of source-based building energy use, and overall source energy based metrics such as energy productivity. This memo reviews the methodological choices, outlines implications of each choice, summarizes responses to a request for information on this topic, and presents guiding principles for the U.S. Department of Energy, (DOE) Office of Energy Efficiency and Renewable Energy (EERE) to use to determine where modifying the current renewable source energy accounting method used in EERE products and analyses would be appropriate to address the issues raised above.

  8. Uranus - Montage of Uranus' five largest satellites.

    NASA Technical Reports Server (NTRS)

    1986-01-01

    Montage of Uranus' five largest satellites. From top to bottom in order of decreasing distance from Uranus are Oberon, Titania, Umbriel, Ariel, and Miranda. Images are presented to show correct relative sizes and brightness. Coverage is incomplete for Miranda and Ariel; gray circles depict missing areas.

  9. 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.

  10. Digitial detecting method of electric or magnetic field sensing signal based on light source modulation

    NASA Astrophysics Data System (ADS)

    Zhang, Weidong; Cui, Xiangqun; Yao, Ruoya

    1996-09-01

    The advantage and disadvantage of the conventional detecting methods of electric or magnetic field sensing signal in the fiber optical sensing system are discussed. A new digital detecting method of electric or magnetic field sensing signal based on the optical modulation and electrical demodulation is proposed in order to eliminate the power frequency and low frequency noises. The digital detecting circuit is designed and the detecting software is developed. In design of the circuit, because the closed-loop synchronous sampling technique is used, not only the leakage effect is controlled and the detecting accuracy is increased, but also the signal processing is simplified, so it has better real-time characteristics. The experiments show that the test results detected by this method have good linearity.

  11. 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)

  12. 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)

  13. 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).

  14. Optimal integration of a hybrid solar-battery power source into smart home nanogrid with plug-in electric vehicle

    NASA Astrophysics Data System (ADS)

    Wu, Xiaohua; Hu, Xiaosong; Teng, Yanqiong; Qian, Shide; Cheng, Rui

    2017-09-01

    Hybrid solar-battery power source is essential in the nexus of plug-in electric vehicle (PEV), renewables, and smart building. This paper devises an optimization framework for efficient energy management and components sizing of a single smart home with home battery, PEV, and potovoltatic (PV) arrays. We seek to maximize the home economy, while satisfying home power demand and PEV driving. Based on the structure and system models of the smart home nanogrid, a convex programming (CP) problem is formulated to rapidly and efficiently optimize both the control decision and parameters of the home battery energy storage system (BESS). Considering different time horizons of optimization, home BESS prices, types and control modes of PEVs, the parameters of home BESS and electric cost are systematically investigated. Based on the developed CP control law in home to vehicle (H2V) mode and vehicle to home (V2H) mode, the home with BESS does not buy electric energy from the grid during the electric price's peak periods.

  15. Application of an electric field for pretreatment of a seeding source for dark fermentative hydrogen production.

    PubMed

    Jeong, Da-Young; Cho, Si-Kyung; Shin, Hang-Sik; Jung, Kyung-Won

    2013-07-01

    In present study, an electric field was newly adopted as a pretreatment method for inoculum preparation in dark fermentative hydrogen production. Various voltages (5-20 V for 10 min) were applied, and the feasibility and efficiency of this method were compared with those of heat pretreatment (90°C for 20 min). Both the highest H2 yield, 1.43 mol H2/mol hexoseadded, and the highest production rate, 101.4 mL H2/L/h, were observed at 10 V. While RNA concentration of above 100mg/L was maintained up to 10 V, it was decreased at an applied voltage of 20 V, where the worst performance was observed. Microbial analysis results confirmed that only H2 producing bacteria were detected with electric pretreatment, while non-H2 producing bacteria coexist with heat and electric (5 V) pretreatment. The results suggested that application of an electric field has reasonable potential as an alternative method for preparing inoculums for hydrogen production.

  16. PFLOTRAN-E4D: A parallel open source PFLOTRAN module for simulating time-lapse electrical resistivity data

    NASA Astrophysics Data System (ADS)

    Johnson, Timothy C.; Hammond, Glenn E.; Chen, Xingyuan

    2017-02-01

    Time-lapse electrical resistivity tomography (ERT) is finding increased application for remotely monitoring processes occurring in the near subsurface in three-dimensions (i.e. 4D monitoring). However, there are few codes capable of simulating the evolution of subsurface resistivity and corresponding tomographic measurements arising from a particular process, particularly in parallel and with an open source license. Herein we describe and demonstrate an electrical resistivity tomography module for the PFLOTRAN subsurface flow and reactive transport simulation code, named PFLOTRAN-E4D. The PFLOTRAN-E4D module operates in parallel using a dedicated set of compute cores in a master-slave configuration. At each time step, the master processes receives subsurface states from PFLOTRAN, converts those states to bulk electrical conductivity, and instructs the slave processes to simulate a tomographic data set. The resulting multi-physics simulation capability enables accurate feasibility studies for ERT imaging, the identification of the ERT signatures that are unique to a given process, and facilitates the joint inversion of ERT data with hydrogeological data for subsurface characterization. PFLOTRAN-E4D is demonstrated herein using a field study of stage-driven groundwater/river water interaction ERT monitoring along the Columbia River, Washington, USA. Results demonstrate the complex nature of subsurface electrical conductivity changes, in both the saturated and unsaturated zones, arising from river stage fluctuations and associated river water intrusion into the aquifer. The results also demonstrate the sensitivity of surface based ERT measurements to those changes over time. PFLOTRAN-E4D is available with the PFLOTRAN development version with an open-source license at https://bitbucket.org/pflotran/pflotran-dev.

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

    PubMed

    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

  18. 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

  19. 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.

  20. World's largest sapphire for many applications

    NASA Astrophysics Data System (ADS)

    Khattak, Chandra P.; Shetty, Raj; Schwerdtfeger, C. Richard; Ullal, Saurabh

    2016-10-01

    Sapphire has been used for many high technology applications because of its excellent optical, mechanical, high temperature, abrasion resistance and dielectric properties. However, it is expensive and the volume of sapphire used has been limited. The potential sapphire requirements for LED and consumer electronic applications are very high. Emphasis has been on producing larger sapphire boules to achieve significant cost reductions so these applications are realized. World's largest sapphire boules, 500 mm diameter 300+kg, have been grown to address these markets.

  1. INTERACTION OF LASER RADIATION WITH MATTER. LASER PLASMA: Quasi-stationary magnetic and electric waves produced by a pulsed shock-wave source

    NASA Astrophysics Data System (ADS)

    Tishchenko, V. N.; Shaikhislamov, I. F.

    2006-01-01

    A merging mechanism of shock waves in a plasma with a magnetic field is considered. The merging criterion is found at which a point source produces low-frequency waves of magnetic and vortex electric fields in the surroundings.

  2. 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.

  3. Feasibility of Isolating Vulnerable Equipment of the Electric Power System from Sources of EMP

    DTIC Science & Technology

    1978-03-01

    generation of skin currents, surface charge densities, and electromagnetic fields, and in coupling mechanisms to internal circuitry. Chadsey, William L., et al...electromagnetic pulse (Wtt) which propagates to the earth’s surface where it induces currents and voltages on conductors over a wide geographical area. The...produce on an electric power system. When a nuclear device is detonated 50 km or more above the earth’s surface , primary gamma rays are produced

  4. Injectable Sources of Locally Controlled Electrical Fields to Facilitate Tissue Repair

    DTIC Science & Technology

    2001-10-25

    Mentes et al [9] investigated the influence of pulsed electromagnetic fields ( PEMFs ) on the mechanical strength and collagen content of uncomplicated...randomly assigned groups were exposed to 100Hz PEMFs at various field strengths (1 or 2 mT) and duty cycles. Mean bursting pressure and hydroxyproline...associated with multiple reports of clinical benefits [11,12,13,14,15]. Both directly applied electrical fields and PEMFs have been associated with

  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. B1-based SAR reconstruction using contrast source inversion-electric properties tomography (CSI-EPT).

    PubMed

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

    2017-02-01

    Specific absorption rate (SAR) assessment is essential for safety purposes during MR acquisition. Online SAR assessment is not trivial and requires, in addition, knowledge of the electric tissue properties and the electric fields in the human anatomy. In this study, the potential of the recently developed CSI-EPT method to reconstruct SAR distributions is investigated. This method is based on integral representations for the electromagnetic field and attempts to reconstruct the tissue parameters and the electric field strength based on [Formula: see text] field data only. Full three-dimensional FDTD simulations using a female pelvis model are used to validate two-dimensional CSI reconstruction results in the central transverse plane of a 3T body coil. Numerical experiments demonstrate that the reconstructed SAR distributions are in good agreement with the SAR distributions as determined via 3D FDTD simulations and show that these distributions can be computed very efficiently in the central transverse plane of a body coil with the two-dimensional approach of CSI-EPT.

  7. 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.

  8. Radiative and nonradiative spontaneous decay rates for an electric quadrupole source in the vicinity of a spherical particle

    SciTech Connect

    Guzatov, D. V.

    2016-04-15

    Analytic expressions for the radiative and nonradiative decay rates for an electric quadrupole source (atom, molecule) in the vicinity of a spherical particle (dielectric, metal) have been derived and analyzed within the classical electrodynamics. It has been shown that the highest increase in the decay rates appears in the quasi-static case, when the wavelength of the transition in question is much larger than the characteristic size of the system formed by the particle and the quadrupole. Asymptotic expressions for the decay rates have been derived for this case.

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

    NASA Astrophysics Data System (ADS)

    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.

  10. 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.

  11. State of Art in the Science and Technology of Electrical Discharge Light Sources

    NASA Astrophysics Data System (ADS)

    Zissis, Georges; Rouffet, Jean-Baptiste

    Light is vital for life: Light sources play an indispensable role to daily life of any Human being. Our World cannot be conceived without light. Quality of life, health and, somehow, urban security related with traffic and crime prevention measures depend on light and on its quality. The lighting industry is an important economic factor in Europe, USA and many Asiatic Countries. All in all, lighting is an important socio-economic factor and lighting system development should be an integral part of any Sustainable Development and of any program of improvement of Quality of Life. This presentation provides an overview of the present state of research in the science and technology of light sources. Existing technologies and future challenges for the lighting industry will be presented. To better understanding the light source technology an part of this presentation will be devoted to the physics of light sources.

  12. 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

  13. 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.

  14. 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.

  15. Electric discharge in water as a source of UV radiation, ozone and hydrogen peroxide

    NASA Astrophysics Data System (ADS)

    Anpilov, A. M.; Barkhudarov, E. M.; Bark, Yu B.; Zadiraka, Yu V.; Christofi, M.; Kozlov, Yu N.; Kossyi, I. A.; Kop'ev, V. A.; Silakov, V. P.; Taktakishvili, M. I.; Temchin, S. M.

    2001-03-01

    Results are presented from investigations of multispark electric discharge in water excited along multielectrode metal-dielectric systems with gas supply into the interelectrode gaps. The intensity distribution of discharge radiation in the region covering the biologically active soft UV (190≤λ≤430 nm) has been determined and the absolute number of quanta in this wavelength interval has been measured. The potentiality of the slipping surface discharge in water for its disinfection is analysed. The energy expenditure for water cleansing is estimated to be as low as ~10-4 kWh l-1.

  16. 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.

  17. 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.

  18. 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.

  19. 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

  20. Flight performance of the largest volant bird.

    PubMed

    Ksepka, Daniel T

    2014-07-22

    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.

  1. Flight performance of the largest volant bird

    NASA Astrophysics Data System (ADS)

    Ksepka, Daniel T.

    2014-07-01

    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.

  2. 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.

  3. The performance of integrated transconductance amplifiers as variable current sources for bio-electric impedance measurements.

    PubMed

    Smith, D N

    1992-01-01

    Multiple applied current impedance measurement systems require numbers of current sources which operate simultaneously at the same frequency and within the same phase but at variable amplitudes. Investigations into the performance of some integrated operational transconductance amplifiers as variable current sources are described. Measurements of breakthrough, non-linearity and common-mode output levels for LM13600, NE5517 and CA3280 were carried out. The effects of such errors on the overall performance and stability of multiple current systems when driving floating loads are considered.

  4. Note: Temperature effects in the modified Howland current source for electrical bioimpedance spectroscopy

    NASA Astrophysics Data System (ADS)

    Fernandez Santos, S.; Bertemes-Filho, P.

    2017-07-01

    The aim of this study is to show how the modified Howland current source (MHCS) is affected by temperature changes. The source has been tested in a temperature range from 20 to 70 °C and frequency range from 100 Hz to 1 MHz. Parameters like output current, output impedance, total harmonic distortion, and oscillation have been measured. The measurements were made inside a temperature controlled environment. It was showed that the MHCS is stable at temperatures below 70 °C. Operational amplifiers with a low temperature drift and matching resistor should be carefully considered in order to prevent oscillations at high temperatures.

  5. 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.

  6. 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)

  7. 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)

  8. Near-field Electrical Detection of Optical Surface Plasmons and Single Plasmon Sources

    NASA Astrophysics Data System (ADS)

    Koppens, Frank; Falk, A.; Yu, C.; Kang, K.; de Leon, N.; Akimov, A.; Jo, M.; Lukin, M.; Park, H.

    2009-05-01

    Surface plasmon polaritons (SPs) are a promising basis for nanoscale photonic circuits and allow for strong coupling between single photon emitters and propagating plasmon modes. However, there is a general tradeoff between the localization of an SP and the efficiency with which it can be detected with conventional far-field optics. In this talk, I will discus a nanoscale all-electrical SP detection technique based on the near-field coupling between propagating surface plasmons and a nanowire field-effect transistor. The detection scheme consists of an Ag nanowire (NW) crossing a Ge NW field-effect transistor. The Ag NW guides SPs to the Ag/Ge junction, where they are converted to electron-hole (e-h) pairs and detected as current through the Ge NW. We use our detectors to electrically detect the plasmon emission from an individual colloidal quantum dot coupled to a SP waveguide. The detectors are highly efficient (0.1 electrons/plasmon), and a plasmonic gating effect can be used to amplify the signal even higher (up to 50 electrons/plasmon). These results enable new and efficient on-chip optical sensing applications and fulfill a key requirement for 'dark' optical frequency nanocircuits in which SPs can be generated, manipulated, and detected without involving far-field radiation.

  9. Near-field electrical detection of optical plasmons and single-plasmon sources

    NASA Astrophysics Data System (ADS)

    Falk, Abram L.; Koppens, Frank H. L.; Yu, Chun L.; Kang, Kibum; de Leon Snapp, Nathalie; Akimov, Alexey V.; Jo, Moon-Ho; Lukin, Mikhail D.; Park, Hongkun

    2009-07-01

    Photonic circuits can be much faster than their electronic counterparts, but they are difficult to miniaturize below the optical wavelength scale. Nanoscale photonic circuits based on surface plasmon polaritons (SPPs) are a promising solution to this problem because they can localize light below the diffraction limit. However, there is a general trade-off between the localization of an SPP and the efficiency with which it can be detected with conventional far-field optics. Here, we describe a new all-electrical SPP detection technique based on the near-field coupling between guided plasmons and a nanowire field-effect transistor. We use the technique to electrically detect the plasmon emission from an individual colloidal quantum dot coupled to an SPP waveguide. Our detectors are both nanoscale and highly efficient (~0.1electrons per plasmon), and a plasmonic gating effect can be used to amplify the signal even higher (up to 50electrons per plasmon). These results may enable new on-chip optical sensing applications and are a key step towards `dark' optoplasmonic nanocircuits in which SPPs can be generated, manipulated and detected without involving far-field radiation.

  10. Characterization of Electricity Generated by Soil in Microbial Fuel Cells and the Isolation of Soil Source Exoelectrogenic Bacteria

    PubMed Central

    Jiang, Yun-Bin; Zhong, Wen-Hui; Han, Cheng; Deng, Huan

    2016-01-01

    Soil has been used to generate electrical power in microbial fuel cells (MFCs) and exhibited several potential applications. This study aimed to reveal the effect of soil properties on the generated electricity and the diversity of soil source exoelectrogenic bacteria. Seven soil samples were collected across China and packed into air-cathode MFCs to generate electricity over a 270 days period. The Fe(III)-reducing bacteria in soil were enriched and sequenced by Illumina pyrosequencing. Culturable strains of Fe(III)-reducing bacteria were isolated and identified phylogenetically. Their exoelectrogenic ability was evaluated by polarization measurement. The results showed that soils with higher organic carbon (OC) content but lower soil pH generated higher peak voltage and charge. The sequencing of Fe(III)-reducing bacteria showed that Clostridia were dominant in all soil samples. At the family level, Clostridiales Family XI incertae sedis were dominant in soils with lower OC content but higher pH (>8), while Clostridiaceae, Lachnospiraceae, and Planococcaceae were dominant in soils with higher OC content but lower pH. The isolated culturable strains were allied phylogenetically to 15 different species, of which 11 were Clostridium. The others were Robinsoniella peoriensis, Hydrogenoanaerobacterium saccharovorans, Eubacterium contortum, and Oscillibacter ruminantium. The maximum power density generated by the isolates in the MFCs ranged from 16.4 to 28.6 mW m-2. We concluded that soil OC content had the most important effect on power generation and that the Clostridiaceae were the dominant exoelectrogenic bacterial group in soil. This study might lead to the discovery of more soil source exoelectrogenic bacteria species. PMID:27877168

  11. Determining the best source of renewable electricity to power a remote site for the National Park Service

    SciTech Connect

    Azerbegl, R.; Mas, C.; Walker, A.; Morris, R.; Christensen, J.

    1999-07-01

    Renewable energy technologies have economic and environmental advantages in many remote applications. They can provide most of the power to off-grid loads, where batteries and another power source such as a generator or a fuel cell may be required to ensure availability and feasibility. In support of the National Park Service, the Federal Energy Management Program Team at the National Renewable Energy Laboratory has evaluated several methods for providing a renewable source of electricity to a beach campsite at Kirby Cove, Marin County, California. This site requires 2 kWh per day to power a campground host in a motor home five months power year. The existing electricity line to the site is in need of replacement and the NPS is interested in evaluating more cost-effective and environmentally sensitive alternatives. Photovoltaics, tidal current, and wind power systems in combination with a back-up electric system (standard, thermoelectric, and Stirling generator and fuel cell) and an energy storage medium (battery, flywheel, and hydrogen) were analyzed. Multi-objective optimization criteria include initial cost, operating cost, emissions, maintenance requirements, and to be consistent with the NPS requirements, the system must be clean, silent, and sustainable. The best system combination was designed according to these evaluation criteria and a demonstration system is to be constructed. This paper describes the optimization procedure and design. Results indicate that a 800 Watt photovoltaic array with a hydrogen fuel cell best serves the requirements for clean, silent power. Since fuel cells are developmental, a propane generator is recommended as an alternative.

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

    PubMed

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

    2011-03-01

    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. Copyright © 2010 Elsevier Ltd. All rights reserved.

  13. 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.

  14. 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

    2015-12-01

    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.

  15. 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

  16. 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.

  17. PFLOTRAN-E4D: A parallel open source PFLOTRAN module for simulating time-lapse electrical resistivity data

    DOE PAGES

    Johnson, Timothy C.; Hammond, Glenn E.; Chen, Xingyuan

    2016-09-22

    Time-lapse electrical resistivity tomography (ERT) is finding increased application for remotely monitoring processes occurring in the near subsurface in three-dimensions (i.e. 4D monitoring). However, there are few codes capable of simulating the evolution of subsurface resistivity and corresponding tomographic measurements arising from a particular process, particularly in parallel and with an open source license. Herein we describe and demonstrate an electrical resistivity tomography module for the PFLOTRAN subsurface flow and reactive transport simulation code, named PFLOTRAN-E4D. The PFLOTRAN-E4D module operates in parallel using a dedicated set of compute cores in a master-slave configuration. At each time step, the master processesmore » receives subsurface states from PFLOTRAN, converts those states to bulk electrical conductivity, and instructs the slave processes to simulate a tomographic data set. The resulting multi-physics simulation capability enables accurate feasibility studies for ERT imaging, the identification of the ERT signatures that are unique to a given process, and facilitates the joint inversion of ERT data with hydrogeological data for subsurface characterization. PFLOTRAN-E4D is demonstrated herein using a field study of stage-driven groundwater/river water interaction ERT monitoring along the Columbia River, Washington, USA. Results demonstrate the complex nature of subsurface electrical conductivity changes, in both the saturated and unsaturated zones, arising from river stage fluctuations and associated river water intrusion into the aquifer. Furthermore, the results also demonstrate the sensitivity of surface based ERT measurements to those changes over time.« less

  18. PFLOTRAN-E4D: A parallel open source PFLOTRAN module for simulating time-lapse electrical resistivity data

    SciTech Connect

    Johnson, Timothy C.; Hammond, Glenn E.; Chen, Xingyuan

    2016-09-22

    Time-lapse electrical resistivity tomography (ERT) is finding increased application for remotely monitoring processes occurring in the near subsurface in three-dimensions (i.e. 4D monitoring). However, there are few codes capable of simulating the evolution of subsurface resistivity and corresponding tomographic measurements arising from a particular process, particularly in parallel and with an open source license. Herein we describe and demonstrate an electrical resistivity tomography module for the PFLOTRAN subsurface flow and reactive transport simulation code, named PFLOTRAN-E4D. The PFLOTRAN-E4D module operates in parallel using a dedicated set of compute cores in a master-slave configuration. At each time step, the master processes receives subsurface states from PFLOTRAN, converts those states to bulk electrical conductivity, and instructs the slave processes to simulate a tomographic data set. The resulting multi-physics simulation capability enables accurate feasibility studies for ERT imaging, the identification of the ERT signatures that are unique to a given process, and facilitates the joint inversion of ERT data with hydrogeological data for subsurface characterization. PFLOTRAN-E4D is demonstrated herein using a field study of stage-driven groundwater/river water interaction ERT monitoring along the Columbia River, Washington, USA. Results demonstrate the complex nature of subsurface electrical conductivity changes, in both the saturated and unsaturated zones, arising from river stage fluctuations and associated river water intrusion into the aquifer. Furthermore, the results also demonstrate the sensitivity of surface based ERT measurements to those changes over time.

  19. 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.

  20. 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.

  1. Improved thermal and electrical design for an all-Si thermoelectric micropower source

    NASA Astrophysics Data System (ADS)

    Donmez, I.; Salleras, M.; Calaza, C.; Gadea, G.; Morata, A.; Tarancón, A.; Fonseca, L.

    2017-05-01

    This work presents current achievements on the fabrication and characterization of an all-Si based planar thermoelectric microgenerator. Ordered dense arrays of Vapor-Liquid-Solid (VLS) grown p-type Si nanowires (Si NWs) are integrated in predefined thermally isolated microstructures as nanostructured thermoelectric active material. Optimizations in device processing and architecture that improved both thermal and electrical performances of the microgenerator resulted in a 70 fold increase in power output. Furthermore, the performance of microgenerators with Si NWs is compared to that of microgenerators with micron-sized Si beams as active material. Additionally, a 60 fold improvement in power output is observed by placing a cold-finger on top of the thermally isolated microstructure to demonstrate the effect of a heat exchanger, which is currently being implemented on the microgenerator.

  2. 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.

  3. Ultraviolet Electrically Injected Light Sources With Epitaxial ZnO-Based Heterojunctions

    DTIC Science & Technology

    2007-08-01

    lighting, UV spectroscopy, and solar blind detectors and imaging arrays, and transparent electronics for displays. These UV devices can also serve to meet...Air Force objectives in areas covert tactical communications, high-speed information processing, solar blind sensing and imaging, and UV spectroscopy...Zn effusion cell resistant to source oxidation have been installed to facilitate ZnO growth. The existing MBE system has demonstrated the ability to

  4. Neutral Beam Source and Target Plasma for Development of a Local Electric Field Fluctuation Diagnostic

    NASA Astrophysics Data System (ADS)

    Bakken, M. R.; Burke, M. G.; Fonck, R. J.; Lewicki, B. T.; Rhodes, A. T.; Winz, G. R.

    2016-10-01

    A new diagnostic measuring local E-> (r , t) fluctuations is being developed for plasma turbulence studies in tokamaks. This is accomplished by measuring fluctuations in the separation of the π components in the Hα motional Stark spectrum. Fluctuations in this separation are expected to be Ẽ / ẼEMSE 10-3EMSE 10-3 . In addition to a high throughput, high speed spectrometer, the project requires a low divergence (Ω 0 .5°) , 80 keV, 2.5 A H0 beam and a target plasma test stand. The beam employs a washer-stack arc ion source to achieve a high species fraction at full energy. Laboratory tests of the ion source demonstrate repeatable plasmas with Te 10 eV and ne 1.6 ×1017 m-3, sufficient for the beam ion optics requirements. Te and ne scalings of the ion source plasma are presented with respect to operational parameters. A novel three-phase resonant converter power supply will provide 6 mA/cm2 of 80 keV H0 at the focal plane for pulse lengths up to 15 ms, with low ripple δV / 80 keV 0.05 % at 280 kHz. Diagnostic development and validation tests will be performed on a magnetized plasma test stand with 0.5 T field. The test chamber will utilize a washer-stack arc source to produce a target plasma comparable to edge tokamak plasmas. A bias-plate with programmable power supply will be used to impose Ẽ within the target plasma. Work supported by US DOE Grant DE-FG02-89ER53296.

  5. The largest volcanic eruptions on Earth

    NASA Astrophysics Data System (ADS)

    Bryan, Scott; Peate, David; Ukstins Peate, Ingrid; Self, Stephen; Mawby, Michael; Jerram, Dougal; Marsh, Goonie

    2010-05-01

    Large igneous provinces (LIPs) are sites of the most frequently recurring, largest volume basaltic and silicic eruptions in Earth history. The magma volumes, eruptive mechanisms, frequency and associated aerosol emissions of these eruptions are critical for understanding any interpreted climate forcing and environmental change by LIPs. The largest volume (>1000 km3 dense rock equivalent) and magnitude (>M8) eruptions produce areally extensive (104-105 km2) basaltic lava flow fields and silicic ignimbrites and 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- 2,000 km3) silicic lava flows have also been mapped out in the Mesoproterozoic Gawler Range province (Australia), an interpreted LIP remnant. Magma volumes of >1000 km3 have also been emplaced as high-level basaltic and rhyolitic sills in LIPs, and may contribute substantial aerosol emissions through shallow degassing and crystallisation. 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 ~107-108 kg s-1 producing dominantly compound pahoehoe lava flow fields. The major flood basalt eruption durations are most

  6. The largest volcanic eruptions on Earth

    NASA Astrophysics Data System (ADS)

    Ukstins Peate, I.; Bryan, S. E.; Peate, D. W.; Self, S.; Mawby, M.; Jerram, D. A.; Marsh, J.

    2010-12-01

    Large igneous provinces (LIPs) host the most frequently recurring, largest volume basaltic & silicic eruptions on Earth. Understanding magma volumes, eruptive mechanisms, frequency and aerosol emissions are critical to interpret climate forcing and environmental change. The largest volume (>1000 km3 dre) and magnitude (>M8) eruptions produce areally extensive (104-105 km2) basaltic flow fields and silicic ignimbrites that are the main building blocks of LIPs. Magma volumes >1000 km3 are also emplaced as high-level basaltic and rhyolitic sills in LIPs, and may contribute substantial aerosol emissions through shallow degassing and crystallization. Basaltic and silicic eruptions have comparable magnitudes, but silicic ignimbrite volumes may be significantly underestimated due to unrecognized and correlated, but voluminous co-ignimbrite ash deposits. Magma composition appears to be no barrier to individual eruption volume. Despite similar magnitudes, flood basaltic and silicic eruptions are very different in eruption mechanism, duration, intensity, vent configuration, and emplacement style. Flood basalts are dominantly effusive Hawaiian-Strombolian, with magma discharge rates of ~107-108 kg/s, and produce dominantly compound pahoehoe flow fields over eruption durations most likely >10 yrs. Some large-volume silicic lavas were emplaced by effusive and fissure eruptions, but discharge rates are unknown and may be up to an order of magnitude greater than those of flood basalt lavas for emplacement to be on realistic time scales (<10 years). Most silicic eruptions are moderately to highly explosive, producing co-current pyroclastic fountains (rarely Plinian) with discharge rates of 109-1011 kg/s that emplace welded to rheomorphic ignimbrites. Stratospheric ash and aerosol injections may be greater from co-ignimbrite ash clouds than eruption plumes. At present, durations for large-magnitude silicic eruptions are unconstrained. At discharge rates of 109 kg/s, equivalent to

  7. 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.

  8. 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.

  9. Scientists conduct largest coastal experiment on record

    NASA Astrophysics Data System (ADS)

    Wakefield, Julie

    Duck, N.C.—Something out of the ordinary has been happening near this quiet, resort town on the Outer Banks. More than 100 coastal scientists, students, and technicians have descended on the Army Corps of Engineer's Waterways Experiment Station primarily to study movement of sediment in the surf zone. In fact, a large percentage of the U.S. near-shore research community has flooded the Duck area to execute the largest coastal experiment ever undertaken. The researchers have brought with them more than 80 computers and an array of exotic gadgets to carry out “DUCK94,” an unprecedented project that has been three years in the making.

  10. 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

  11. New Global 3D Upper to Mid-mantle Electrical Conductivity Model Based on Observatory Data with Realistic Auroral Sources

    NASA Astrophysics Data System (ADS)

    Kelbert, A.; Egbert, G. D.; Sun, J.

    2011-12-01

    Poleward of 45-50 degrees (geomagnetic) observatory data are influenced significantly by auroral ionospheric current systems, invalidating the simplifying zonal dipole source assumption traditionally used for long period (T > 2 days) geomagnetic induction studies. Previous efforts to use these data to obtain the global electrical conductivity distribution in Earth's mantle have omitted high-latitude sites (further thinning an already sparse dataset) and/or corrected the affected transfer functions using a highly simplified model of auroral source currents. Although these strategies are partly effective, there remain clear suggestions of source contamination in most recent 3D inverse solutions - specifically, bands of conductive features are found near auroral latitudes. We report on a new approach to this problem, based on adjusting both external field structure and 3D Earth conductivity to fit observatory data. As an initial step towards full joint inversion we are using a two step procedure. In the first stage, we adopt a simplified conductivity model, with a thin-sheet of variable conductance (to represent the oceans) overlying a 1D Earth, to invert observed magnetic fields for external source spatial structure. Input data for this inversion are obtained from frequency domain principal components (PC) analysis of geomagnetic observatory hourly mean values. To make this (essentially linear) inverse problem well-posed we regularize using covariances for source field structure that are consistent with well-established properties of auroral ionospheric (and magnetospheric) current systems, and basic physics of the EM fields. In the second stage, we use a 3D finite difference inversion code, with source fields estimated from the first stage, to further fit the observatory PC modes. We incorporate higher latitude data into the inversion, and maximize the amount of available information by directly inverting the magnetic field components of the PC modes, instead of

  12. Slow spindles' cortical generators overlap with the epileptogenic zone in temporal epileptic patients: an electrical source imaging study.

    PubMed

    Del Felice, Alessandra; Arcaro, Chiara; Storti, Silvia Francesca; Fiaschi, Antonio; Manganotti, Paolo

    2013-12-01

    To determine whether temporal epileptic patients and normal volunteers display similar sleep spindles' cortical generators as determined by electrical source imaging (ESI), and whether such generators overlap in epilepsy patients with the epileptogenic zone identified by ESI. Twelve healthy subjects and twelve temporal lobe pharmaco-resistant epileptic patients underwent a 256-channel EEG recording during a daytime nap. Sleep spindles were analyzed off line, distinguishing slow (10-12 Hz) and fast (12-14 Hz) ones, and the final averaged signal was projected onto a MNI (Montreal Neurological Institute) space to localize cortical generators. The same procedure was performed for averaged epileptic spikes, obtaining their cortical source. Intra- and inter-group statistical analyses were conducted. Multiple, concomitant generators were detected in both populations for slow and fast spindles. Slow spindles in epileptics displayed higher source amplitude in comparison to healthy volunteers (Z=0.001), as well as a preferential localization over the affected temporal cortices (p=0.039). Interestingly, at least one of slow spindles' generators overlapped with the epileptogenic zone. Slow spindles, but not fast ones, in temporal epilepsy are mainly generated by the affected temporal lobe. These results point to the strict relation between sleep and epilepsy and to the possible cognitive implications of spikes arising from memory-encoding brain structures. Copyright © 2013 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

  13. Source locations for impulsive electric signals seen in the night ionosphere of Venus

    NASA Technical Reports Server (NTRS)

    Russell, C. T.; Von Dornum, M.; Scarf, F. L.

    1989-01-01

    A mapping of the rate of occurrence of impulsive VLF noise bursts in Venus' dark low altitude ionosphere, which increases rapidly with decreasing altitude, as a function of latitude and longitude indicates enhanced occurrence rates over Atla. In a 30-sec observing period, there are impulsive signals 70 percent of the time at 160 km in the region of maximum occurrence; the occurrence rates, moreover, increase with decreasing latitude, so that the equatorial rate is of the order of 1.6 times that at 30 deg latitude. These phenomena are in keeping with lightning-generated wave sources.

  14. 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.

  15. 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

  16. 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.

  17. 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.

  18. Pre-earthquake signals - Part I: Deviatoric stresses turn rocks into a source of electric currents

    NASA Astrophysics Data System (ADS)

    Freund, F. T.

    2007-09-01

    Earthquakes are feared because they often strike so suddenly. Yet, there are innumerable reports of pre-earthquake signals. Widespread disagreement exists in the geoscience community how these signals can be generated in the Earth's crust and whether they are early warning signs, related to the build-up of tectonic stresses before major seismic events. Progress in understanding and eventually using these signals has been slow because the underlying physical process or processes are basically not understood. This has changed with the discovery that, when igneous or high-grade metamorphic rocks are subjected to deviatoric stress, dormant electronic charge carriers are activated: electrons and defect electrons. The activation increases the number density of mobile charge carriers in the rocks and, hence, their electric conductivity. The defect electrons are associated with the oxygen anion sublattice and are known as positive holes or pholes for short. The boundary between stressed and unstressed rock acts a potential barrier that lets pholes pass but blocks electrons. Therefore, like electrons and ions in an electrochemical battery, the stress-activated electrons and pholes in the "rock battery" have to flow out in different directions. When the circuit is closed, the battery currents can flow. The discovery of such stress-activated currents in crustal rocks has far-reaching implications for understanding pre-earthquake signals.

  19. 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.

  20. Development of integrated fuel cell hybrid power source for electric forklift

    NASA Astrophysics Data System (ADS)

    Keränen, T. M.; Karimäki, H.; Viitakangas, J.; Vallet, J.; Ihonen, J.; Hyötylä, P.; Uusalo, H.; Tingelöf, T.

    A hybrid drivetrain comprising a 16 kW polymer electrolyte membrane fuel cell system, ultracapacitor modules and a lead-acid battery was constructed and experimentally tested in a real counterweight forklift application. A scaled-down version of the hybrid system was assembled and tested in a controlled laboratory environment using a controllable resistive load. The control loops were operating in an in-house developed embedded system. The software is designed for building generic control applications, and the source code has been released as open source and made available on the internet. The hybrid drivetrain supplied the required 50 kW peak power in a typical forklift work cycle consisting of both loaded and unloaded driving, and lifting of a 2.4 tonne load. Load variations seen by the fuel cell were a fraction of the total current drawn by the forklift, with the average fuel cell power being 55% of nominal rating. A simple fuel cell hybrid model was also developed to further study the effects of energy storage dimensioning. Simulation results indicate that while a battery alone significantly reduces the load variations of the fuel cell, an ultracapacitor reduces them even further. Furthermore, a relatively small ultracapacitor is enough to achieve most of the potential benefit.

  1. Fuel Cell/Electric Double Layer Capacitor Hybrid Power Source Using a Multi-port Bidirectional DC-DC Converter

    NASA Astrophysics Data System (ADS)

    Katayama, Noboru; Kogoshi, Sumio

    A fuel cell/electric double layer capacitor hybrid power source using a multi-port bidirectional DC-DC converter has been developed to reduce load variations for the purpose of extending fuel cell life. The proposed converter operates to maintain the fuel cell current, load voltage and bus voltage at constant values with a digital signal processor. The effect of the proposed converter is evaluated. The charging or discharging current of the EDLC rapidly changes along with step loading, and the voltage and current of the fuel cell are maintained at the constant values. Short-time transient responses show that the fuel cell current ripples 0.35 A at 1 A load change in 6 ms.

  2. 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.

  3. 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.

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

    PubMed

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

    2014-02-01

    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.

  5. Largest clinic in the world? (Bogota).

    PubMed

    1971-01-01

    The IPPF member, the Asociacion Pro-Bienestar de la Familia Colombiana (Profamilia), is discussed and its clinic, the Pilot Center in Bogota, reputed to be the largest family clinic in the world, is described. From January 1966 until the end of 1970, the Pilot Center served 59,469 new acceptors. Of the 31 Profamilia clinics in Colombia, the Pilot Center was visited by 22% of all new acceptors during 1970. Profamilia established the first vasectomy clinic in Latin America in February 1970. By the end of 1970, 92 vasectomies had been performed. Profamilia has expanded its family planning program, and part of this expansion is a result of Profamilia's extensive use of mass media in its education campaign. In 1970, there was a 24% increase in new acceptors over 1969 and a 66% increase in follow-up visits. 62,292 radio spots and 7 television programs were broadcast and announcements about family planning were shown in public cinemas in the latter half of 1970. Nearly 300,000 women attended talks, meetings, and film shows on family planning, and approximately 2 million leaflets and information sheets were distributed. To increase community involvement, Profamilia held 26 short courses for various groups including religious and community leaders. Profamilia also conducted a training course for doctors and sociologists from Colombia and other Latin American countries.

  6. Analytical solutions of electric potential and impedance for a multilayered spherical volume conductor excited by time-harmonic electric current source: application in brain EIT

    NASA Astrophysics Data System (ADS)

    Xiao, Chunyan; Lei, Yinzhao

    2005-06-01

    A model of a multilayered spherical volume conductor with four electrodes is built. In this model, a time-harmonic electric current is injected into the sphere through a pair of drive electrodes, and electric potential is measured by the other pair of measurement electrodes. By solving the boundary value problem of the electromagnetic field, the analytical solutions of electric potential and impedance in the whole conduction region are derived. The theoretical values of electric potential on the surface of the sphere are in good accordance with the experimental results. The analytical solutions are then applied to the simulation of the forward problem of brain electrical impedance tomography (EIT). The results show that, for a real human head, the imaginary part of the electric potential is not small enough to be ignored at above 20 kHz, and there exists an approximate linear relationship between the real and imaginary parts of the electric potential when the electromagnetic parameters of the innermost layer keep unchanged. Increase in the conductivity of the innermost layer leads to a decrease of the magnitude of both real and imaginary parts of the electric potential on the scalp. However, the increase of permittivity makes the magnitude of the imaginary part of the electric potential increase while that of the real part decreases, and vice versa.

  7. Electric Eel-Skin-Inspired Mechanically Durable and Super-Stretchable Nanogenerator for Deformable Power Source and Fully Autonomous Conformable Electronic-Skin Applications.

    PubMed

    Lai, Ying-Chih; Deng, Jianan; Niu, Simiao; Peng, Wenbo; Wu, Changsheng; Liu, Ruiyuan; Wen, Zhen; Wang, Zhong Lin

    2016-12-01

    Electric eel-skin-inspired mechanically durable and super-stretchable nanogenerator is demonstrated for the first time by using triboelectric effect. This newly designed nanogenerator can produce electricity by touch or tapping despite under various extreme mechanical deformations or even after experiencing damage. This device can be used not only as deformable and wearable power source but also as fully autonomous and self-sufficient adaptive electronic skin system.

  8. Excitation Method of Linear-Motor-Type Rail Brake without Using Power Sources by Dynamic Braking with Zero Electrical Output

    NASA Astrophysics Data System (ADS)

    Sakamoto, Yasuaki; Kashiwagi, Takayuki; Hasegawa, Hitoshi; Sasakawa, Takashi; Fujii, Nobuo

    The eddy current rail brake is a type of braking system used in railway vehicles. Because of problems such as rail heating and problems associated with ensuring that power is supplied when the feeder malfunctions, this braking system has not been used for practical applications in Japan. Therefore, we proposed the use of linear induction motor (LIM) technology in eddy current rail brake systems. The LIM rail brake driven by dynamic braking can reduce rail heating and generate the energy required for self-excitation. In this paper, we present an excitation system and control method for the LIM rail brake driven by “dynamic braking with zero electrical output”. The proposed system is based on the concept that the LIM rail brake can be energized without using excitation power sources such as a feeder circuit and that high reliability can be realized by providing an independent excitation system. We have studied this system and conducted verification tests using a prototype LIM rail brake on a roller rig. The results show that the system performance is adequate for commercializing the proposed system, in which the LIM rail brake is driven without using any excitation power source.

  9. Development of Grounded Electrical Source Airborne Transient EM (GREATEM) Survey System and Its Application to Investigating a Volcano Structure

    NASA Astrophysics Data System (ADS)

    Mogi, T.; Jomori, A.; Jomori, N.; Azuma, Y.; Fomenko, E. Y.

    2005-12-01

    We have developed an airborne EM system that uses a grounded electrical source and an airborne magnetic field receiver to increase the depth of investigation. Using a grounded source, we can apply a large source moment with a long transmitter-receiver distance, thus we expect to obtain a greater depth of investigation. However, the area of survey is limited with this type of method, but it has some advantages such as little effect of flight level etc. We believe that a repeated survey in active area such as volcano or fault area is effective for monitoring activity in the whole area. By using the airborne survey, we will be able to make repeated survey rapidly in volcano area where it is difficult to enter by a ground survey. The initial stage of the development was reported at Mogi et al. (1998) and the survey system was named as GREATEM (Grounded electrical source airborne transient EM). Time domain data acquisition has an advantage to the deep exploration because it avoids near source field effects that occur in frequency domain measurements. To realize the method, we should overcome mainly two problems: monitoring and filtering the motion noise of the receiver and canceling the natural magnetic field variation and cultural noise without stacking in the time domain data. We prepared high accuracy fiber optic gyros to monitor the pitch and roll of the magnetic sensor in the bird to monitor the motion and also manufactured an electromagnetic receiver that can detect three components of magnetic field and a tilt meter with MI sensor which can detect up to_ 100,000 nT with a sensitivity of 0.04 mV/nT. These receiver and tilt meter are installed on a gimbal in a bird. Data acquisition system is installed in the helicopter cabin with high precision GPS synchronized with the same type GPS set in the transmitter. In this system, we designed to analyze full wave data in time-domain for investigating deep to shallow underground resistivity structure. The measured data of

  10. Rethinking how to address the world's largest infectious killer in the world's largest country.

    PubMed

    Bloom, Barry R

    2016-05-06

    India has the largest number of people suffering from tuberculosis (TB) of any country in the world. Analysis of the increasing Multi-Drug Resistant TB problem has revealed multiple challenges to the health system that must be addressed in order to control the TB epidemic there.Journal of Public Health Policy advance online publication, 6 May 2016 doi:10.1057/jphp.2016.16.

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

    SciTech Connect

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

    2016-02-15

    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{sup 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.

  12. Experimental evidence of edge intrinsic momentum source driven by kinetic ion loss and edge radial electric fields in tokamaks

    NASA Astrophysics Data System (ADS)

    Boedo, J. A.; deGrassie, J. S.; Grierson, B.; Stoltzfus-Dueck, T.; Battaglia, D. J.; Rudakov, D. L.; Belli, E. A.; Groebner, R. J.; Hollmann, E.; Lasnier, C.; Solomon, W. M.; Unterberg, E. A.; Watkins, J.

    2016-09-01

    Bulk ion toroidal velocity profiles, V| | D + , peaking at 40-60 km/s are observed with Mach probes in a narrow edge region of DIII-D discharges without external momentum input. This intrinsic rotation can be well reproduced by a first principle, collisionless kinetic loss model of thermal ion loss that predicts the existence of a loss-cone distribution in velocity space resulting in a co-Ip directed velocity. We consider two kinetic models, one of which includes turbulence-enhanced momentum transport, as well as the Pfirsch-Schluter (P-S) fluid mechanism. We measure a fine structure of the boundary radial electric field, Er, insofar ignored, featuring large (10-20 kV/m) positive peaks in the scrape off layer (SOL) at, or slightly inside, the last closed flux surface of these low power L- and H-mode discharges in DIII-D. The Er structure significantly affects the ion-loss model, extended to account for a non-uniform electric field. We also find that V| | D + is reduced when the magnetic topology is changed from lower single null to upper single null. The kinetic ion loss model containing turbulence-enhanced momentum transport can explain the reduction, as we find that the potential fluctuations decay with radius, while we need to invoke a topology-enhanced collisionality on the simpler kinetic model. The P-S mechanism fails to reproduce the damping. We show a clear correlation between the near core V| | C 6 + velocity and the peak edge V| | D + in discharges with no external torque, further supporting the hypothesis that ion loss is the source for intrinsic torque in the present tokamaks. However, we also show that when external torque is injected in the core, it can complete with, and eventually overwhelm, the edge source, thus determining the near SOL flows. Finally, we show some additional evidence that the ion/electron distribution in the SOL is non-Maxwellian.

  13. Experimental evidence of edge intrinsic momentum source driven by kinetic ion loss and edge radial electric fields in tokamaks

    SciTech Connect

    Boedo, J. A.; deGrassie, J. S.; Grierson, B.; Stoltzfus-Dueck, T.; Battaglia, D. J.; Rudakov, D. L.; Belli, E. A.; Groebner, R. J.; Hollmann, E.; Lasnier, C.; Solomon, W. M.; Unterberg, E. A.; Watkins, J.

    2016-09-21

    Here, bulk ion toroidal velocity profiles, VD+||, peaking at 40–60 km/s are observed with Mach probes in a narrow edge region of DIII-D discharges without external momentum input. This intrinsic rotation can be well reproduced by a first principle, collisionless kinetic loss model of thermal ion loss that predicts the existence of a loss-cone distribution in velocity space resulting in a co-Ip directed velocity. We consider two kinetic models, one of which includes turbulence-enhanced momentum transport, as well as the Pfirsch-Schluter (P-S) fluid mechanism. We measure a fine structure of the boundary radial electric field, Er, insofar ignored, featuring large (10–20 kV/m) positive peaks in the scrape off layer (SOL) at, or slightly inside, the last closed flux surface of these low power L- and H-mode discharges in DIII-D. The Er structure significantly affects the ion-loss model, extended to account for a non-uniform electric field. We also find that VD+|| is reduced when the magnetic topology is changed from lower single null to upper single null. The kinetic ion loss model containing turbulence-enhanced momentum transport can explain the reduction, as we find that the potential fluctuations decay with radius, while we need to invoke a topology-enhanced collisionality on the simpler kinetic model. The P-S mechanism fails to reproduce the damping. We show a clear correlation between the near core VC6+|| velocity and the peak edge VD+|| in discharges with no external torque, further supporting the hypothesis that ion loss is the source for intrinsic torque in the present tokamaks. However, we also show that when external torque is injected in the core, it can complete with, and eventually overwhelm, the edge source, thus determining the near SOL flows. Finally, we show some additional evidence that the ion/electron distribution in the SOL is non-Maxwellian.

  14. Experimental evidence of edge intrinsic momentum source driven by kinetic ion loss and edge radial electric fields in tokamaks

    DOE PAGES

    Boedo, J. A.; deGrassie, J. S.; Grierson, B.; ...

    2016-09-21

    Here, bulk ion toroidal velocity profiles, VD+||, peaking at 40–60 km/s are observed with Mach probes in a narrow edge region of DIII-D discharges without external momentum input. This intrinsic rotation can be well reproduced by a first principle, collisionless kinetic loss model of thermal ion loss that predicts the existence of a loss-cone distribution in velocity space resulting in a co-Ip directed velocity. We consider two kinetic models, one of which includes turbulence-enhanced momentum transport, as well as the Pfirsch-Schluter (P-S) fluid mechanism. We measure a fine structure of the boundary radial electric field, Er, insofar ignored, featuring largemore » (10–20 kV/m) positive peaks in the scrape off layer (SOL) at, or slightly inside, the last closed flux surface of these low power L- and H-mode discharges in DIII-D. The Er structure significantly affects the ion-loss model, extended to account for a non-uniform electric field. We also find that VD+|| is reduced when the magnetic topology is changed from lower single null to upper single null. The kinetic ion loss model containing turbulence-enhanced momentum transport can explain the reduction, as we find that the potential fluctuations decay with radius, while we need to invoke a topology-enhanced collisionality on the simpler kinetic model. The P-S mechanism fails to reproduce the damping. We show a clear correlation between the near core VC6+|| velocity and the peak edge VD+|| in discharges with no external torque, further supporting the hypothesis that ion loss is the source for intrinsic torque in the present tokamaks. However, we also show that when external torque is injected in the core, it can complete with, and eventually overwhelm, the edge source, thus determining the near SOL flows. Finally, we show some additional evidence that the ion/electron distribution in the SOL is non-Maxwellian.« less

  15. Experimental evidence of edge intrinsic momentum source driven by kinetic ion loss and edge radial electric fields in tokamaks

    SciTech Connect

    Boedo, J. A.; deGrassie, J. S.; Grierson, B.; Stoltzfus-Dueck, T.; Battaglia, D. J.; Rudakov, D. L.; Belli, E. A.; Groebner, R. J.; Hollmann, E.; Lasnier, C.; Solomon, W. M.; Unterberg, E. A.; Watkins, J.

    2016-09-01

    Bulk ion toroidal velocity profiles, V|| D+ , peaking at 40-60 km/s are observed with Mach probes in a narrow edge region of DIII-D discharges without external momentum input. This intrinsic rotation can be well reproduced by a first principle, collisionless kinetic loss model of thermal ion loss that predicts the existence of a loss-cone distribution in velocity space resulting in a co-Ip directed velocity. We consider two kinetic models, one of which includes turbulence-enhanced momentum transport, as well as a third, the Pfirsch-Schluter (P-S) fluid mechanism. We measure a fine structure of the boundary radial electric field, Er, previously ignored, featuring large (10–20 kV/m) positive peaks in the scrape off layer (SOL) at, or slightly inside, the last closed flux 2 surface (LCFS) of these low power L- and H-mode discharges in DIII-D. The Er structure significantly affects the ion-loss model, extended to account for a non-uniform electric field. We also find that V|| D+ is reduced when the magnetic topology is changed from lower single null (LSN) to upper single null (USN). The kinetic ion loss model containing turbulence-enhanced momentum transport can explain the reduction, as we find that the potential fluctuation profile differs between USN and LSN discharges, while we need to invoke a topology-enhanced collisionality on the simpler kinetic model. The P-S mechanism fails to reproduce the damping. We show a clear correlation between the near core V|| C6+ velocity and the peak edge V|| D+ in discharges with no external torque, further supporting the hypothesis that ion loss is the source for intrinsic torque in present tokamaks. However, we also show that when external torque is injected in the core, it can compete with, and eventually overwhelm, the edge source. Finally, we show some additional evidence that the ion/electron distribution in the SOL is non-Maxwellian.

  16. Experimental evidence of edge intrinsic momentum source driven by kinetic ion loss and edge radial electric fields in tokamaks

    SciTech Connect

    Boedo, J. A.; deGrassie, J. S.; Grierson, B.; Stoltzfus-Dueck, T.; Battaglia, D. J.; Rudakov, D. L.; Belli, E. A.; Groebner, R. J.; Hollmann, E.; Lasnier, C.; Solomon, W. M.; Unterberg, E. A.; Watkins, J.

    2016-09-21

    Here, bulk ion toroidal velocity profiles, VD+||, peaking at 40–60 km/s are observed with Mach probes in a narrow edge region of DIII-D discharges without external momentum input. This intrinsic rotation can be well reproduced by a first principle, collisionless kinetic loss model of thermal ion loss that predicts the existence of a loss-cone distribution in velocity space resulting in a co-Ip directed velocity. We consider two kinetic models, one of which includes turbulence-enhanced momentum transport, as well as the Pfirsch-Schluter (P-S) fluid mechanism. We measure a fine structure of the boundary radial electric field, Er, insofar ignored, featuring large (10–20 kV/m) positive peaks in the scrape off layer (SOL) at, or slightly inside, the last closed flux surface of these low power L- and H-mode discharges in DIII-D. The Er structure significantly affects the ion-loss model, extended to account for a non-uniform electric field. We also find that VD+|| is reduced when the magnetic topology is changed from lower single null to upper single null. The kinetic ion loss model containing turbulence-enhanced momentum transport can explain the reduction, as we find that the potential fluctuations decay with radius, while we need to invoke a topology-enhanced collisionality on the simpler kinetic model. The P-S mechanism fails to reproduce the damping. We show a clear correlation between the near core VC6+|| velocity and the peak edge VD+|| in discharges with no external torque, further supporting the hypothesis that ion loss is the source for intrinsic torque in the present tokamaks. However, we also show that when external torque is injected in the core, it can complete with, and eventually overwhelm, the edge source, thus determining the near SOL flows. Finally, we show some additional evidence that the ion/electron distribution in the SOL is non-Maxwellian.

  17. Experimental evidence of edge intrinsic momentum source driven by kinetic ion loss and edge radial electric fields in tokamaks

    DOE PAGES

    Boedo, J. A.; deGrassie, J. S.; Grierson, B.; ...

    2016-09-21

    Here, bulk ion toroidal velocity profiles, VD+||, peaking at 40–60 km/s are observed with Mach probes in a narrow edge region of DIII-D discharges without external momentum input. This intrinsic rotation can be well reproduced by a first principle, collisionless kinetic loss model of thermal ion loss that predicts the existence of a loss-cone distribution in velocity space resulting in a co-Ip directed velocity. We consider two kinetic models, one of which includes turbulence-enhanced momentum transport, as well as the Pfirsch-Schluter (P-S) fluid mechanism. We measure a fine structure of the boundary radial electric field, Er, insofar ignored, featuring largemore » (10–20 kV/m) positive peaks in the scrape off layer (SOL) at, or slightly inside, the last closed flux surface of these low power L- and H-mode discharges in DIII-D. The Er structure significantly affects the ion-loss model, extended to account for a non-uniform electric field. We also find that VD+|| is reduced when the magnetic topology is changed from lower single null to upper single null. The kinetic ion loss model containing turbulence-enhanced momentum transport can explain the reduction, as we find that the potential fluctuations decay with radius, while we need to invoke a topology-enhanced collisionality on the simpler kinetic model. The P-S mechanism fails to reproduce the damping. We show a clear correlation between the near core VC6+|| velocity and the peak edge VD+|| in discharges with no external torque, further supporting the hypothesis that ion loss is the source for intrinsic torque in the present tokamaks. However, we also show that when external torque is injected in the core, it can complete with, and eventually overwhelm, the edge source, thus determining the near SOL flows. Finally, we show some additional evidence that the ion/electron distribution in the SOL is non-Maxwellian.« less

  18. Experimental evidence of edge intrinsic momentum source driven by kinetic ion loss and edge radial electric fields in tokamaks

    DOE PAGES

    Boedo, J. A.; deGrassie, J. S.; Grierson, B.; ...

    2016-09-01

    Bulk ion toroidal velocity profiles, V|| D+ , peaking at 40-60 km/s are observed with Mach probes in a narrow edge region of DIII-D discharges without external momentum input. This intrinsic rotation can be well reproduced by a first principle, collisionless kinetic loss model of thermal ion loss that predicts the existence of a loss-cone distribution in velocity space resulting in a co-Ip directed velocity. We consider two kinetic models, one of which includes turbulence-enhanced momentum transport, as well as a third, the Pfirsch-Schluter (P-S) fluid mechanism. We measure a fine structure of the boundary radial electric field, Er, previouslymore » ignored, featuring large (10–20 kV/m) positive peaks in the scrape off layer (SOL) at, or slightly inside, the last closed flux 2 surface (LCFS) of these low power L- and H-mode discharges in DIII-D. The Er structure significantly affects the ion-loss model, extended to account for a non-uniform electric field. We also find that V|| D+ is reduced when the magnetic topology is changed from lower single null (LSN) to upper single null (USN). The kinetic ion loss model containing turbulence-enhanced momentum transport can explain the reduction, as we find that the potential fluctuation profile differs between USN and LSN discharges, while we need to invoke a topology-enhanced collisionality on the simpler kinetic model. The P-S mechanism fails to reproduce the damping. We show a clear correlation between the near core V|| C6+ velocity and the peak edge V|| D+ in discharges with no external torque, further supporting the hypothesis that ion loss is the source for intrinsic torque in present tokamaks. However, we also show that when external torque is injected in the core, it can compete with, and eventually overwhelm, the edge source. Finally, we show some additional evidence that the ion/electron distribution in the SOL is non-Maxwellian.« less

  19. 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.

  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. Multisensory processing of naturalistic objects in motion: a high-density electrical mapping and source estimation study.

    PubMed

    Senkowski, Daniel; Saint-Amour, Dave; Kelly, Simon P; Foxe, John J

    2007-07-01

    In everyday life, we continuously and effortlessly integrate the multiple sensory inputs from objects in motion. For instance, the sound and the visual percept of vehicles in traffic provide us with complementary information about the location and motion of vehicles. Here, we used high-density electrical mapping and local auto-regressive average (LAURA) source estimation to study the integration of multisensory objects in motion as reflected in event-related potentials (ERPs). A randomized stream of naturalistic multisensory-audiovisual (AV), unisensory-auditory (A), and unisensory-visual (V) "splash" clips (i.e., a drop falling and hitting a water surface) was presented among non-naturalistic abstract motion stimuli. The visual clip onset preceded the "splash" onset by 100 ms for multisensory stimuli. For naturalistic objects early multisensory integration effects beginning 120-140 ms after sound onset were observed over posterior scalp, with distributed sources localized to occipital cortex, temporal lobule, insular, and medial frontal gyrus (MFG). These effects, together with longer latency interactions (210-250 and 300-350 ms) found in a widespread network of occipital, temporal, and frontal areas, suggest that naturalistic objects in motion are processed at multiple stages of multisensory integration. The pattern of integration effects differed considerably for non-naturalistic stimuli. Unlike naturalistic objects, no early interactions were found for non-naturalistic objects. The earliest integration effects for non-naturalistic stimuli were observed 210-250 ms after sound onset including large portions of the inferior parietal cortex (IPC). As such, there were clear differences in the cortical networks activated by multisensory motion stimuli as a consequence of the semantic relatedness (or lack thereof) of the constituent sensory elements.

  2. Do Skilled Elementary Teachers Hold Scientific Conceptions and Can They Accurately Predict the Type and Source of Students' Preconceptions of Electric Circuits?

    ERIC Educational Resources Information Center

    Lin, Jing-Wen

    2016-01-01

    Holding scientific conceptions and having the ability to accurately predict students' preconceptions are a prerequisite for science teachers to design appropriate constructivist-oriented learning experiences. This study explored the types and sources of students' preconceptions of electric circuits. First, 438 grade 3 (9 years old) students were…

  3. Do Skilled Elementary Teachers Hold Scientific Conceptions and Can They Accurately Predict the Type and Source of Students' Preconceptions of Electric Circuits?

    ERIC Educational Resources Information Center

    Lin, Jing-Wen

    2016-01-01

    Holding scientific conceptions and having the ability to accurately predict students' preconceptions are a prerequisite for science teachers to design appropriate constructivist-oriented learning experiences. This study explored the types and sources of students' preconceptions of electric circuits. First, 438 grade 3 (9 years old) students were…

  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. A Plan for a Ten-fold Improvement of the Neutron Electric Dipole Moment with the LANL UCN Source

    NASA Astrophysics Data System (ADS)

    Liu, Chen-Yu; Clayton, Steve; Currie, Scott; Ito, Takeyasu; Makela, Mark; Morris, Chris; Pattie, Robert; Ramsey, John; Saunders, Andy; Tang, Zhaowen; Long, Josh; Snow, Mike; Plaster, Brad; Lamoreaux, S. K.; Sharapov, E.; LANL nEDM Collaboration

    2016-09-01

    The Electric Dipole Moment of the neutron is a probe for the violations in the combined Charge-conjugate and Parity-reversal symmetry. Many theories beyond the Standard Model, which aim to unify the fundamental forces and solve the problem of Baryon Asymmetry of the Universe, also predict sizable EDM just lurking around the corner for discovery. However, the low density of UCN limits the worldwide progress of current nEDM experiments; existing facilities have not been able to deliver significantly higher UCN flux. An opportunity exists in the LANL UCN facility: With an order of magnitude increase in the LANL UCN source intensity, one could realize a nEDM search at the 10-27e-cm level of sensitivity soon. An upgrade to the LANL UCN facility is now underway; it will provide the UCN flux needed to meet the demand of this experiment. We will apply the Ramsey's separated oscillatory field method to measure the precession frequency of the neutron under a small, precisely controlled, static magnetic field. We will report the status and plan of the LANL nEDM experiment. The IU group acknowledges the support of NSF Grant #1306942.

  6. Open source software for electric field Monte Carlo simulation of coherent backscattering in biological media containing birefringence.

    PubMed

    Radosevich, Andrew J; Rogers, Jeremy D; Capoğlu, Ilker R; Mutyal, Nikhil N; Pradhan, Prabhakar; Backman, Vadim

    2012-11-01

    ABSTRACT. We present an open source electric field tracking Monte Carlo program to model backscattering in biological media containing birefringence, with computation of the coherent backscattering phenomenon as an example. These simulations enable the modeling of tissue scattering as a statistically homogeneous continuous random media under the Whittle-Matérn model, which includes the Henyey-Greenstein phase function as a special case, or as a composition of discrete spherical scatterers under Mie theory. The calculation of the amplitude scattering matrix for the above two cases as well as the implementation of birefringence using the Jones N-matrix formalism is presented. For ease of operator use and data processing, our simulation incorporates a graphical user interface written in MATLAB to interact with the underlying C code. Additionally, an increase in computational speed is achieved through implementation of message passing interface and the semi-analytical approach. Finally, we provide demonstrations of the results of our simulation for purely scattering media and scattering media containing linear birefringence.

  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. Electric vehicles

    SciTech Connect

    Not Available

    1990-03-01

    Quiet, clean, and efficient, electric vehicles (EVs) may someday become a practical mode of transportation for the general public. Electric vehicles can provide many advantages for the nation's environment and energy supply because they run on electricity, which can be produced from many sources of energy such as coal, natural gas, uranium, and hydropower. These vehicles offer fuel versatility to the transportation sector, which depends almost solely on oil for its energy needs. Electric vehicles are any mode of transportation operated by a motor that receives electricity from a battery or fuel cell. EVs come in all shapes and sizes and may be used for different tasks. Some EVs are small and simple, such as golf carts and electric wheel chairs. Others are larger and more complex, such as automobile and vans. Some EVs, such as fork lifts, are used in industries. In this fact sheet, we will discuss mostly automobiles and vans. There are also variations on electric vehicles, such as hybrid vehicles and solar-powered vehicles. Hybrid vehicles use electricity as their primary source of energy, however, they also use a backup source of energy, such as gasoline, methanol or ethanol. Solar-powered vehicles are electric vehicles that use photovoltaic cells (cells that convert solar energy to electricity) rather than utility-supplied electricity to recharge the batteries. This paper discusses these concepts.

  9. Electric vehicles

    NASA Astrophysics Data System (ADS)

    1990-03-01

    Quiet, clean, and efficient, electric vehicles (EVs) may someday become a practical mode of transportation for the general public. Electric vehicles can provide many advantages for the nation's environment and energy supply because they run on electricity, which can be produced from many sources of energy such as coal, natural gas, uranium, and hydropower. These vehicles offer fuel versatility to the transportation sector, which depends almost solely on oil for its energy needs. Electric vehicles are any mode of transportation operated by a motor that receives electricity from a battery or fuel cell. EVs come in all shapes and sizes and may be used for different tasks. Some EVs are small and simple, such as golf carts and electric wheel chairs. Others are larger and more complex, such as automobile and vans. Some EVs, such as fork lifts, are used in industries. In this fact sheet, we will discuss mostly automobiles and vans. There are also variations on electric vehicles, such as hybrid vehicles and solar-powered vehicles. Hybrid vehicles use electricity as their primary source of energy, however, they also use a backup source of energy, such as gasoline, methanol or ethanol. Solar-powered vehicles are electric vehicles that use photovoltaic cells (cells that convert solar energy to electricity) rather than utility-supplied electricity to recharge the batteries. These concepts are discussed.

  10. 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

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

    SciTech Connect

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

    2016-03-15

    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{sup 13} fissions per second. The transfer line enables the unstable isotopes generated by the {sup 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.

  12. 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.

  13. Combined electroencephalography-functional magnetic resonance imaging and electrical source imaging improves localization of pediatric focal epilepsy.

    PubMed

    Centeno, Maria; Tierney, Tim M; Perani, Suejen; Shamshiri, Elhum A; St Pier, Kelly; Wilkinson, Charlotte; Konn, Daniel; Vulliemoz, Serge; Grouiller, Frédéric; Lemieux, Louis; Pressler, Ronit M; Clark, Christopher A; Cross, J Helen; Carmichael, David W

    2017-08-01

    Surgical treatment in epilepsy is effective if the epileptogenic zone (EZ) can be correctly localized and characterized. Here we use simultaneous electroencephalography-functional magnetic resonance imaging (EEG-fMRI) data to derive EEG-fMRI and electrical source imaging (ESI) maps. Their yield and their individual and combined ability to (1) localize the EZ and (2) predict seizure outcome were then evaluated. Fifty-three children with drug-resistant epilepsy underwent EEG-fMRI. Interictal discharges were mapped using both EEG-fMRI hemodynamic responses and ESI. A single localization was derived from each individual test (EEG-fMRI global maxima [GM]/ESI maximum) and from the combination of both maps (EEG-fMRI/ESI spatial intersection). To determine the localization accuracy and its predictive performance, the individual and combined test localizations were compared to the presumed EZ and to the postsurgical outcome. Fifty-two of 53 patients had significant maps: 47 of 53 for EEG-fMRI, 44 of 53 for ESI, and 34 of 53 for both. The EZ was well characterized in 29 patients; 26 had an EEG-fMRI GM localization that was correct in 11, 22 patients had ESI localization that was correct in 17, and 12 patients had combined EEG-fMRI and ESI that was correct in 11. Seizure outcome following resection was correctly predicted by EEG-fMRI GM in 8 of 20 patients, and by the ESI maximum in 13 of 16. The combined EEG-fMRI/ESI region entirely predicted outcome in 9 of 9 patients, including 3 with no lesion visible on MRI. EEG-fMRI combined with ESI provides a simple unbiased localization that may predict surgery better than each individual test, including in MRI-negative patients. Ann Neurol 2017;82:278-287. © 2017 American Neurological Association.

  14. Computation of surface electrical potentials of plant cell membranes . Correspondence To published zeta potentials from diverse plant sources

    PubMed

    Kinraide; Yermiyahu; Rytwo

    1998-10-01

    A Gouy-Chapman-Stern model has been developed for the computation of surface electrical potential (psi0) of plant cell membranes in response to ionic solutes. The present model is a modification of an earlier version developed to compute the sorption of ions by wheat (Triticum aestivum L. cv Scout 66) root plasma membranes. A single set of model parameters generates values for psi0 that correlate highly with published zeta potentials of protoplasts and plasma membrane vesicles from diverse plant sources. The model assumes ion binding to a negatively charged site (R- = 0.3074 &mgr;mol m-2) and to a neutral site (P0 = 2.4 &mgr;mol m-2) according to the reactions R- + IZ &rlharr; RIZ-1 and P0 + IZ &rlharr; PIZ, where IZ represents an ion of charge Z. Binding constants for the negative site are 21, 500 M-1 for H+, 20,000 M-1 for Al3+, 2,200 M-1 for La3+, 30 M-1 for Ca2+ and Mg2+, and 1 M-1 for Na+ and K+. Binding constants for the neutral site are 1/180 the value for binding to the negative site. Ion activities at the membrane surface, computed on the basis of psi0, appear to determine many aspects of plant-mineral interactions, including mineral nutrition and the induction and alleviation of mineral toxicities, according to previous and ongoing studies. A computer program with instructions for the computation of psi0, ion binding, ion concentrations, and ion activities at membrane surfaces may be requested from the authors.

  15. Electric and hybrid vehicles program

    NASA Astrophysics Data System (ADS)

    1992-05-01

    The Department of Energy's (DOE) Electric and Hybrid Vehicles (EHV) Program is conducting research, development, testing, and evaluation activities to encourage the use of electricity and alternative fuels for transportation. This program supports the expanded DOE involvement as recommended in the National Energy Strategy. The transportation sector is the single largest user of petroleum; it consumed 63 percent of all petroleum used in the United States last year. Only a small fraction (5 percent) of electricity is generated from petroleum. Electric vehicles, which are themselves virtually pollution-free, could play a key role in helping to reduce both urban pollution and our dependence on petroleum imports. The program's goals are to develop, in cooperation with industry, the technology that will lead to the production and introduction of pollution-free electric vehicles into the Nation's transportation fleet and substitute domestic sources of energy for petroleum-based fuels. This report describes progress achieved in developing electric and hybrid vehicle technologies, beginning with highlights of recent accomplishments in FY-91. Detailed descriptions are provided of program activities during FY-91 in the areas of battery, fuel-cell, and propulsion system development, and testing and evaluation of new technology in fleet site operations and in laboratories. In accordance with the reporting requirements of the Act, this annual report contains a status report on incentives and use of foreign components and concludes with a list of publications resulting from the DOE program.

  16. Exact calculation of the angular momentum loss, recoil force, and radiation intensity for an arbitrary source in terms of electric, magnetic, and toroid multipoles.

    PubMed

    Radescu, E E; Vaman, G

    2002-04-01

    An exact calculation of the radiation intensity, angular momentum loss, and the recoil force for the most general type of source, characterized by electric, magnetic, and toroid multipole moments and radii of any multipolarity and an arbitrary time dependence, is presented. The results are expressed in terms of time derivatives of the multipole moments and mean radii of the corresponding distributions. Although quite cumbersome, the formulas found by us represent exact results in the correct multipole analysis of configurations of charges and currents that contain toroidal sources. So the longstanding problem in classical electrodynamics of relating the radiation properties of a system to quantities completely describing its internal electromagnetic structure is thereby exactly solved. By particularizations to the first multipole contributions, corrections to the familiar formulas from books are found, mostly on account of the toroid moments and their interference with the usual electric and magnetic ones.

  17. Earth to space dc to dc power transmission system utilizing a microwave beam as source of energy for electric propelled interorbital vehicles

    NASA Technical Reports Server (NTRS)

    Brown, W. C.

    1985-01-01

    The paper contributes to the credibility of an electric propelled interorbital transportation system by introducing a new low-mass source of continuous dc power for electric propulsion and illustrating how the source can be economically tied to an electric utility on earth by an electronically steered microwave beam. The new thin-film rectenna, which functions as the receiving end of an earth-to-space microwave power transmission system is described. It is easily fabricated, is over 80 percent efficient, has a specific mass of no more than 2 kilograms per kilowatt of continuous dc power output, and is well adapted for deployment in space. The paper then describes a complete system consisting of the interorbital vehicle and the microwave power transmission system that supplies it with power. A design scenario is used to obtain performance data from the system in terms of vehicle transfer times, payload fractions, and costs. Electric energy costs are found to be less than $1000 per kilogram of payload delivered to geosynchronous orbit from low-earth orbit.

  18. 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.

  19. Runaway breakdown in strong electric field as a source of terrestrial gamma flashes and gamma bursts in lightning leader steps

    NASA Astrophysics Data System (ADS)

    Gurevich, A. V.; Zybin, K. P.; Medvedev, Yu. V.

    2007-01-01

    The new model of lightning step leader is proposed. It includes three main processes developing simultaneously in a strong electric field: conventional breakdown, effect of runaway electrons and runaway breakdown (RB). The theory of RB in strong electric field is developed. Comparison with the existing observational data shows that the model can serve as a background for the explanation of gamma bursts in step leader and TGF.

  20. Ultra-wide Field Imaging and Swept Source Optical Coherence Tomography of Ocular Electrical Injury in a Child.

    PubMed

    Takkar, Brijesh; Azad, Shorya; Molla, Kabiruddin; Venkatesh, Pradeep

    2016-12-08

    History of trauma in children may be obscured and physicians often rely on signs for diagnosis. The authors discuss a case of electrical injury where ocular signs led to diagnosis of the cause of macular atrophy. A high index of suspicion must always be maintained in such atypical cases, and the setting of electrical injury to the body requires meticulous ocular examination. [J Pediatr Ophthalmol Strabismus. 2016;53:e69-e71.].

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

    PubMed

    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.

  2. 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

  3. Electric Utility Phase I Acid Rain Compliance Strategies for the Clean Air Act Amendments of 1990

    EIA Publications

    1994-01-01

    The Acid Rain Program is divided into two time periods; Phase I, from 1995 through 1999, and Phase II, starting in 2000. Phase I mostly affects power plants that are the largest sources of SO2 and NOx . Phase II affects virtually all electric power producers, including utilities and nonutilities. This report is a study of the effects of compliance with Phase I regulations on the costs and operations of electric utilities, but does not address any Phase II impacts.

  4. A new method to determine the ratio of electricity production from fossil and biogenic sources in waste-to-Energy plants.

    PubMed

    Fellner, Johann; Cencic, Oliver; Rechberger, Helmut

    2007-04-01

    New directives of the European Union require operators of waste-to-energy (WTE) plants to report the amount of electricity that is produced from renewable sources in the waste feed. Until now, the standard method to determine the portion of renewable electricity is sorting the wastes into defined fractions of fossil organic and biogenic waste components and determining the lower heating value of these fractions. Out of it the amount of electricity production from renewables is calculated. This practice is labor and cost intensive. Therefore, it is usually carried out once a year which provides only a snapshot analysis of limited significance. This paper proposes a method to calculate the portion of electricity produced from renewable materials in waste continuously by solving a set of equations. All data required are either available from literature or from operating data routinely measured in WTE plants. The advantages are statistically derived uncertainty of the result, temporal resolution of the result down to daily mean values, low implementation efforts, and virtually no operational costs. An example of the implementation of the method to a 60 000 tons per year WTE plant is given.

  5. A comparative study on electrical characteristics of crystalline AlN thin films deposited by ICP and HCPA-sourced atomic layer deposition

    NASA Astrophysics Data System (ADS)

    Altuntas, Halit; Bayrak, Turkan

    2016-12-01

    In this work, we aimed to investigate the effects of two different plasma sources on the electrical properties of low-temperature plasma-assisted atomic layer deposited (PA-ALD) AlN thin films. To compare the electrical properties, 50 nm thick AlN films were grown on p-type Si substrates at 200 °C by using an inductively coupled RF-plasma (ICP) and a stainless steel hollow cathode plasma-assisted (HCPA) ALD systems. Al/AlN/p-Si metal-insulator-semiconductor (MIS) capacitor devices were fabricated and capacitance versus voltage (C-V) and current-voltage (I-V) measurements performed to assess the basic important electrical parameters such as dielectric constant, effective charge density, flat-band voltage, breakdown field, and threshold voltage. In addition, structural properties of the films were presented and compared. The results show that although HCPA-ALD deposited AlN thin films has structurally better and has a lower effective charge density (N eff ) value than ICP-ALD deposited AlN films, those films have large leakage current, low dielectric constant, and low breakdown field. This situation was attributed to the involvement of Si atoms into the AlN layers during the HCPA-ALD processing leads to additional current path at AlN/Si interface and might impair the electrical properties.

  6. Label-free biosensor based on an electrical tracing-assisted silicon microring resonator with a low-cost broadband source.

    PubMed

    Kim, Kyung Woo; Song, Junfeng; Kee, Jack Sheng; Liu, Qing; Lo, Guo-Qiang; Park, Mi Kyoung

    2013-08-15

    We present a novel biosensor based on an electrical tracing-assisted silicon dual-microring resonator sensor system. The dual-microring system comprises one microring resonator as a sensing element and the other microring resonator integrated with an electrical controller as a tracing element. The resonance wavelength shift of the sensing microring induced by the refractive index change due to antigen-ligand bindings is traced and determined by direct voltage applied to the electrical tunable tracing microring. The sensor system enables the use of a low-cost broadband light source instead of a bulky and expensive tunable laser, which allows the development of cost-effective point-of-care diagnostic devices by significantly reducing the device cost and increasing its portability. The sensing capability of the developed dual-microring sensor was investigated using biotin-streptavidin binding as a model system. We have demonstrated the quantitative detection of streptavidin over a broad range of concentrations down to 190 pM by monitoring the electrical power applied to the tracing ring. We have also validated the sensing principle of the dual-microring system by a direct comparison between the calculated and measured values for the resonance wavelength shift of the sensing microring. Furthermore, we have shown the quantitative and specific detection of a well-known breast cancer biomarker, human epidermal growth factor receptor 2 (HER2), in a bovine serum albumin solution using the antibody-modified dual-microring sensor system.

  7. A comparative study on electrical characteristics of crystalline AlN thin films deposited by ICP and HCPA-sourced atomic layer deposition

    NASA Astrophysics Data System (ADS)

    Altuntas, Halit; Bayrak, Turkan

    2017-03-01

    In this work, we aimed to investigate the effects of two different plasma sources on the electrical properties of low-temperature plasma-assisted atomic layer deposited (PA-ALD) AlN thin films. To compare the electrical properties, 50 nm thick AlN films were grown on p-type Si substrates at 200 °C by using an inductively coupled RF-plasma (ICP) and a stainless steel hollow cathode plasma-assisted (HCPA) ALD systems. Al/AlN/ p-Si metal-insulator-semiconductor (MIS) capacitor devices were fabricated and capacitance versus voltage ( C- V) and current-voltage ( I- V) measurements performed to assess the basic important electrical parameters such as dielectric constant, effective charge density, flat-band voltage, breakdown field, and threshold voltage. In addition, structural properties of the films were presented and compared. The results show that although HCPA-ALD deposited AlN thin films has structurally better and has a lower effective charge density ( N eff ) value than ICP-ALD deposited AlN films, those films have large leakage current, low dielectric constant, and low breakdown field. This situation was attributed to the involvement of Si atoms into the AlN layers during the HCPA-ALD processing leads to additional current path at AlN/Si interface and might impair the electrical properties.

  8. Sources of Variability in Working Memory in Early Childhood: A Consideration of Age, Temperament, Language, and Brain Electrical Activity

    ERIC Educational Resources Information Center

    Wolfe, Christy D.; Bell, Martha Ann

    2007-01-01

    This study investigated age-related differences in working memory and inhibitory control (WMIC) in 3 1/2-, 4-, and 4 1/2-year-olds and how these differences were associated with differences in regulatory aspects of temperament, language comprehension, and brain electrical activity. A series of cognitive control tasks was administered to measure…

  9. Sources of ionospheric electric field data in SuperDARN and DMSP measurements: Issues of data coverage, integrity, and consistency

    NASA Astrophysics Data System (ADS)

    Ruohoniemi, J. M.; Greenwald, R. A.; Hairston, M. R.

    2003-04-01

    One of the essential inputs for data-based assimilation models of the ITM system is the distribution of convection electric field within the high-latitude regions. This electric field gives rise to an ExB plasma drift in the ionosphere that can be observed directly by radars and satellites. Within the last decade the expansion of the radar-based SuperDARN system in particular has greatly increased the availability of electric field measurements. At times the coverage provided by SuperDARN extends over most of the polar cap. The temporal resolution is typically 1-2 minutes. The satellites of the DMSP program measure the full 2-dimensional convection electric field vector along the satellite trajectories at about 80 min cadence. Often there is sufficient overlap to directly compare the measurements and check on consistency. For the purposes of developing or testing assimilation models it will be important to identify anomalies within the data sets and to reconcile the differences. In this talk we discuss the application of SuperDARN data to the specification of the space environment and the coverage that is possible by combining the two data sets. Using periods of extensive, near-simultaneous measurements between SuperDARN and DMSP we consider issues of consistency between the data sets. We discuss the trade-offs involved with maximizing coverage versus ensuring data reliability.

  10. Sources of Variability in Working Memory in Early Childhood: A Consideration of Age, Temperament, Language, and Brain Electrical Activity

    ERIC Educational Resources Information Center

    Wolfe, Christy D.; Bell, Martha Ann

    2007-01-01

    This study investigated age-related differences in working memory and inhibitory control (WMIC) in 3 1/2-, 4-, and 4 1/2-year-olds and how these differences were associated with differences in regulatory aspects of temperament, language comprehension, and brain electrical activity. A series of cognitive control tasks was administered to measure…

  11. Growth and electrical properties of Pb(Zr,Ti)O 3 thin films by a chemical solution deposition method using zirconyl heptanoate as zirconium source

    NASA Astrophysics Data System (ADS)

    Bao, Dinghua; Yao, Xi; Shinozaki, Kazuo; Mizutani, Nobuyasu

    2003-12-01

    Pb(Zr,Ti)O 3 (PZT) thin films were prepared on (1 1 1) Pt-coated Si substrates by a chemical solution deposition method using zirconyl heptanoate as zirconium source instead of commonly used zirconium alkoxides. The effects of processing conditions on the microstructure and electrical properties of the PZT thin films were investigated. The texture of the PZT thin films could be changed by selecting different heat-treatment methods. Orientation-dependent electrical properties, including dielectric constant, polarization, and coercive field, were examined. The randomly oriented PZT thin films annealed at 600°C for 0.5 h showed a well-defined ferroelectric hysteresis loop with a remanent polarization of 18 μC/cm 2 and a coercive field of 74 kV/cm.

  12. Testing a Parachute for Mars in World Largest Wind Tunnel

    NASA Image and Video Library

    2007-12-20

    The team developing the landing system for NASA Mars Science Laboratory tested the deployment of an early parachute design in mid-October 2007 inside the world largest wind tunnel, at NASA Ames Research Center, Moffett Field, California.

  13. Estimating the power-law distribution of Earth electrical conductivity from low-frequency, controlled-source electromagnetic responses

    SciTech Connect

    Beskardes, G. D.; Weiss, Chester J.; Everett, M. E.

    2016-11-30

    Electromagnetic responses reflect the interaction between applied electromagnetic fields and heterogeneous geoelectrical structures. Here by quantifying the relationship between multi-scale electrical properties and the observed electromagnetic response is therefore important for meaningful geologic interpretation. Furthermore, we present here examples of near-surface electromagnetic responses whose spatial fluctuations appear on all length scales, are repeatable and fractally distributed, suggesting that the spatial fluctuations may be considered as “geologic noise”.

  14. Estimating the power-law distribution of Earth electrical conductivity from low-frequency, controlled-source electromagnetic responses

    DOE PAGES

    Beskardes, G. D.; Weiss, Chester J.; Everett, M. E.

    2016-11-30

    Electromagnetic responses reflect the interaction between applied electromagnetic fields and heterogeneous geoelectrical structures. Here by quantifying the relationship between multi-scale electrical properties and the observed electromagnetic response is therefore important for meaningful geologic interpretation. Furthermore, we present here examples of near-surface electromagnetic responses whose spatial fluctuations appear on all length scales, are repeatable and fractally distributed, suggesting that the spatial fluctuations may be considered as “geologic noise”.

  15. Thermal burn and electrical injuries among electric utility workers, 1995-2004.

    PubMed

    Fordyce, Tiffani A; Kelsh, Michael; Lu, Elizabeth T; Sahl, Jack D; Yager, Janice W

    2007-03-01

    This study describes the occurrence of work-related injuries from thermal-, electrical- and chemical-burns among electric utility workers. We describe injury trends by occupation, body part injured, age, sex, and circumstances surrounding the injury. This analysis includes all thermal, electric, and chemical injuries included in the Electric Power Research Institute (EPRI) Occupational Health and Safety Database (OHSD). There were a total of 872 thermal burn and electric shock injuries representing 3.7% of all injuries, but accounting for nearly 13% of all medical claim costs, second only to the medical costs associated with sprain- and strain-related injuries (38% of all injuries). The majority of burns involved less than 1 day off of work. The head, hands, and other upper extremities were the body parts most frequently injured by burns or electric shocks. For this industry, electric-related burns accounted for the largest percentage of burn injuries, 399 injuries (45.8%), followed by thermal/heat burns, 345 injuries (39.6%), and chemical burns, 51 injuries (5.8%). These injuries also represented a disproportionate number of fatalities; of the 24 deaths recorded in the database, contact with electric current or with temperature extremes was the source of seven of the fatalities. High-risk occupations included welders, line workers, electricians, meter readers, mechanics, maintenance workers, and plant and equipment operators.

  16. Electrical resistivity change in Al:ZnO thin films dynamically deposited by bipolar pulsed direct-current sputtering and a remote plasma source

    SciTech Connect

    Yang, Wonkyun; Joo, Junghoon

    2010-07-15

    The Al-doped ZnO (AZO) thin films for a transparent conducting oxide in solar cell devices were deposited by bipolar pulsed dc magnetron sputtering. This work was performed in an in-line type system and investigated AZO films in a static deposition mode and dynamic one, which is more important in the practical fields. Because of this dynamic deposition process, the zigzagged columnar structure was observed. This resulted in the decreasing electrical property, optical properties, and surface roughness. As a deposition in the dynamic mode, the resistivity increased from 1.64x10{sup -3} to 2.50x10{sup -3} {Omega} cm, as compared to that in the static mode, and the transmittance also decreased from 83.9% to 78.3%. To recover the disadvantage, a remote plasma source (RPS) was supported between the substrate and target for reducing zigzagged formation during the deposition. The deposition rate decreased by using RPS, but the electrical and optical properties of films got better than only dynamic mode. The resistivity and transmittance in the dynamic mode using RPS were 2.1x10{sup -3} {Omega} cm and 85.5%, respectively. In this study, the authors found the possibility to advance the electrical and optical properties of AZO thin films in the industry mode.

  17. Using solar-powered refrigeration for vaccine storage where other sources of reliable electricity are inadequate or costly.

    PubMed

    McCarney, Steve; Robertson, Joanie; Arnaud, Juliette; Lorenson, Kristina; Lloyd, John

    2013-12-09

    Large areas of many developing countries have no grid electricity. This is a serious challenge that threatens the continuity of the vaccine cold chain. The main alternatives to electrically powered refrigerators available for many years--kerosene- and gas-driven refrigerators--are plagued by problems with gas supply interruptions, low efficiency, poor temperature control, and frequent maintenance needs. There are currently no kerosene- or gas-driven refrigerators that qualify under the minimum standards established by the World Health Organization (WHO) Performance, Quality, and Safety (PQS) system. Solar refrigeration was a promising development in the early 1980s, providing an alternative to absorption technology to meet cold chain needs in remote areas. Devices generally had strong laboratory performance data; however, experience in the field over the years has been mixed. Traditional solar refrigerators relied on relatively expensive battery systems, which have demonstrated short lives compared to the refrigerator. There are now alternatives to the battery-based systems and a clear understanding that solar refrigerator systems need to be designed, installed, and maintained by technicians with the necessary knowledge and training. Thus, the technology is now poised to be the refrigeration method of choice for the cold chain in areas with no electricity or extremely unreliable electricity (less than 4h per average day) and sufficient sunlight. This paper highlights some lessons learned with solar-powered refrigeration, and discusses some critical factors for successful introduction of solar units into immunization programs in the future including: •Sustainable financing mechanisms and incentives for health workers and technicians are in place to support long-term maintenance, repair, and replacement parts. •System design is carried out by qualified solar refrigerator professionals taking into account the conditions at installation sites. •Installation and

  18. Electrically conductive properties of Ag/Si composite nanoparticle assembled films prepared with a plasma-gas-condensation cluster source

    NASA Astrophysics Data System (ADS)

    Kurokawa, Yuichiro; Hihara, Takehiko

    2014-11-01

    Ag1-x/Six composite nanoparticle assembled films were prepared using a plasma-gas-condensation cluster beam deposition apparatus. The electrical conductivity σ and Hall coefficient |RH| of Ag1-x/Six nanoparticle assembled films obey a power law of the volume fraction of Ag pAg. The marked change at around pAg = pc indicates that the percolation of Ag nanoparticles takes place at the threshold value pc. Moreover, we found that the |RH| at T = 5 K of the Ag1-x/Six nanoparticle assembled film with the closest pAg to pc is 20 times higher than that of the bulk Ag.

  19. Design of a pulse-triggered four-channel functional electrical stimulator using complementary current source and time division multiplexing output method.

    PubMed

    Wang, Hai-Peng; Wang, Zhi-Gong; Lü, Xiao-Ying; Huang, Zong-Hao; Zhou, Yu-Xuan

    2015-08-01

    In this paper, a four-channel pulse-triggered functional electrical stimulator using complementary current source and time division output method is proposed for the research and application of functional electrical stimulation (FES). The high-voltage compliance and output impedance is increased by adopting the complementary current source, which can also realize the linear voltage-to-current conversion and high channel isolation. A high-voltage analog switch chip MAX14803, combined with a FIFO queue algorithm in the microprocessor, is used to setup the H-bridge and multiplexers for the four-channel time division multiplexing output. With this method, the size and cost of the key components are reduced greatly. The stimulating core circuit area is 30 × 50 mm(2). According to the experiments, the stimulator can achieve the four-channel charge-balanced biphasic stimulation with a current range between 0 and 60 mA and a single-phase pulse amplitude up to 60 V.

  20. Modeling the effects of changes in New Source Review on national SO{sub 2} and NOx emissions from electricity-generating units

    SciTech Connect

    David A. Evans; Benjamin F. Hobbs; Craig Oren; Karen L. Palmer

    2007-03-15

    The Clean Air Act establishes New Source Review (NSR) programs that apply to the construction or modification of major stationary emissions sources. In 2002 and 2003, the U.S. Environmental Protection Agency revised its rules to narrow the applicability of NSR to facility renovations. Congress then mandated a National Research Council study of the effects of the rules. An electricity-sector model - the Integrated Planning Model (IPM) - was used to explore the possible effects of the equipment replacement provision (ERP), the principal NSR change that was to affect the power-generation industry. The studies focused in particular on coal-fired electricity generating units, EGUs, for two reasons. First, coal-fired EGUs are important contributors of these pollutants, accounting for approximately 70 and 20% of nations SO{sub 2} and NOx emissions in 2004, respectively. Second, the shares of total capacity of large coal-fired EGUs that lack flue-gas desulfurization to control SO{sub 2} and selective catalytic reduction to reduce NOx emissions are 62 and 63% respectively. Although the analysis cannot predict effects on local emissions, assuming that the Clean Air Interstate Rule (CAIR) is implemented, we find that stringent enforcement of the previous NSR rules would likely lead to no or limited decreases in national emissions compared to policies such as ERP. Our results indicate that tighter emissions caps could achieve further decreases in national emissions more cost-effectively than NSR programs. 15 refs., 3 figs., 1 tab.

  1. Effect of pulsed electric field (PEF) on structures and antioxidant activity of soybean source peptides-SHCMN.

    PubMed

    Lin, Songyi; Liang, Rong; Li, Xingfang; Xing, Jie; Yuan, Yuan

    2016-12-15

    Recently, high-intensity pulsed electric field (PEF) has successfully used in improvement of antioxidant activity. Ser-His-Cys-Met-Asn (SHCMN) obtained from soybean protein was chosen to investigate the phenomenon of antioxidant activity improvement. Effects of PEF treatment on antioxidant activity of SHCMN were evaluated by DPPH radical inhibition. Nuclear magnetic resonance (NMR), mid-infrared (MIR), circular dichroism (CD) were used to analyze structures of SHCMN. Two-factor-at-a-time results show that DPPH radical inhibition of SHCMN is significantly (P<0.05) increased to 94.35±0.03% at conditions of electric field intensity of 5kV/cm, pulse frequency of 2400Hz, and retention time of 2h. In addition, MIR and NMR spectra show that the basic structure of peptides SHCMN is stable by PEF treatment. But the secondary structures (α-helix, β-turn, and random coil) can be affected and zeta potential of PEF-treated SHCNM was reduced to 0.59±0.03mV. The antioxidant activity improvement of SHCMN might result from the changes of secondary structures and zeta potential. Copyright © 2016 Elsevier Ltd. All rights reserved.

  2. A disposable power source in resource-limited environments: A paper-based biobattery generating electricity from wastewater.

    PubMed

    Fraiwan, Arwa; Kwan, Landen; Choi, Seokheun

    2016-11-15

    We report a novel paper-based biobattery which generates power from microorganism-containing liquid derived from renewable and sustainable wastewater which is readily accessible in the local environment. The device fuses the art of origami and the technology of microbial fuel cells (MFCs) and has the potential to shift the paradigm for flexible and stackable paper-based batteries by enabling exceptional electrical characteristics and functionalities. 3D, modular, and retractable battery stack is created from (i) 2D paper sheets through high degrees of folding and (ii) multifunctional layers sandwiched for MFC device configuration. The stack is based on ninja star-shaped origami design formed by eight MFC modular blades, which is retractable from sharp shuriken (closed) to round frisbee (opened). The microorganism-containing wastewater is added into an inlet of the closed battery stack and it is transported into each MFC module through patterned fluidic pathways in the paper layers. During operation, the battery stack is transformed into the round frisbee to connect eight MFC modules in series for improving the power output and simultaneously expose all air-cathodes to the air for their cathodic reactions. The device generates desired values of electrical current and potential for powering an LED for more than 20min.

  3. Analysis of lightning-ionosphere interaction using simultaneous records of source current and 380 km distant electric field

    NASA Astrophysics Data System (ADS)

    Azadifar, Mohammad; Li, Dongshuai; Rachidi, Farhad; Rubinstein, Marcos; Diendorfer, Gerhard; Schulz, Wolfgang; Pichler, Hannes; Rakov, Vladimir A.; Paolone, Mario; Pavanello, Davide

    2017-06-01

    We present simultaneous current and wideband electric field waveforms at 380 km associated with upward lightning flashes initiated from the Säntis Tower, Switzerland. To the best of our knowledge, the dataset presented in this study includes the first simultaneous records of lightning currents and associated fields featuring ionospheric reflections for natural upward flashes, and the longest distance at which natural upward lightning fields have been measured simultaneously with their causative currents. The intervals between the groundwave and skywave arrival times are used to estimate ionospheric reflection heights during day and night times using the so-called zero-to-zero and peak-to-peak methods. During daytime, the mean ionospheric reflection heights, obtained using the two different delay estimation approaches, are about 78 and 76 km, corresponding to the D layer. The mean reflection height at nighttime is about 90 and 89 km, corresponding to the E layer. We present a full-wave, finite-difference time-domain (FDTD) analysis of the electric field propagation including the effect of the ionospheric reflections. The FDTD simulation results are compared with the measured fields associated with upward flashes initiated from the Säntis Tower. It is found that the model reproduces reasonably well the measured waveforms and the times of arrival of the one-hop and two-hop skywaves relative to the groundwave.

  4. Application of Spatial Data Modeling and Geographical Information Systems (GIS) for Identification of Potential Siting Options for Various Electrical Generation Sources

    SciTech Connect

    Mays, Gary T; Belles, Randy; Blevins, Brandon R; Hadley, Stanton W; Harrison, Thomas J; Jochem, Warren C; Neish, Bradley S; Omitaomu, Olufemi A; Rose, Amy N

    2012-05-01

    Oak Ridge National Laboratory (ORNL) initiated an internal National Electric Generation Siting Study, which is an ongoing multiphase study addressing several key questions related to our national electrical energy supply. This effort has led to the development of a tool, OR-SAGE (Oak Ridge Siting Analysis for power Generation Expansion), to support siting evaluations. The objective in developing OR-SAGE was to use industry-accepted approaches and/or develop appropriate criteria for screening sites and employ an array of Geographic Information Systems (GIS) data sources at ORNL to identify candidate areas for a power generation technology application. The initial phase of the study examined nuclear power generation. These early nuclear phase results were shared with staff from the Electric Power Research Institute (EPRI), which formed the genesis and support for an expansion of the work to several other power generation forms, including advanced coal with carbon capture and storage (CCS), solar, and compressed air energy storage (CAES). Wind generation was not included in this scope of work for EPRI. The OR-SAGE tool is essentially a dynamic visualization database. The results shown in this report represent a single static set of results using a specific set of input parameters. In this case, the GIS input parameters were optimized to support an economic study conducted by EPRI. A single set of individual results should not be construed as an ultimate energy solution, since US energy policy is very complex. However, the strength of the OR-SAGE tool is that numerous alternative scenarios can be quickly generated to provide additional insight into electrical generation or other GIS-based applications. The screening process divides the contiguous United States into 100 x 100 m (1-hectare) squares (cells), applying successive power generation-appropriate site selection and evaluation criteria (SSEC) to each cell. There are just under 700 million cells representing the

  5. Watching the Creation of Southern California's Largest Reservoir

    NASA Technical Reports Server (NTRS)

    2001-01-01

    The new Diamond Valley Lake Reservoir near the city of Hemet in Riverside County is billed as the largest earthworks construction project in U.S.history. Construction began in 1995 and involved 31 million cubic meters of foundation excavation and 84 million cubic meters of embankment construction. This set of MISR images captures the most recent phase in the reservoir's activation. At the upper left is a natural-color view acquired by the instrument's vertical-viewing (nadir) camera on March 14, 2000 (Terra orbit 1273), shortly after the Metropolitan Water District began filling the reservoir with water from the Colorado River and Northern California. Water appears darker than the surrounding land. The image at the upper right was acquired nearly one year later on March 1, 2001 (Terra orbit 6399), and shows a clear increase in the reservoir's water content. When full, the lake will hold nearly a trillion liters of water.

    According to the Metropolitan Water District, the 7 kilometer x 3 kilometer reservoir nearly doubles Southern California's above-groundwater storage capacity. In addition to routine water management, Diamond Valley Lake is designed to provide protection against drought and a six-month emergency supply in the event of earthquake damage to a major aqueduct. In the face of electrical power shortages, it is also expected to reduce dependence on the pumping of water from northern mountains during the high-demand summer months. An unexpected result of site excavation was the uncovering of mastodon and mammoth skeletons along with bones from extinct species not previously thought to have been indigenous to the area, such as the giant long-horned bison and North American lion. A museum and interpretive center is being built to protect these finds.

    The lower MISR image, from May 20, 2001 (Terra orbit 7564), is a false-color view combining data from the instrument's 26-degree forward view (displayed as blue) with data from the 26-degree backward

  6. Drilling the Bushveld Complex- the world's largest layered mafic intrusion

    NASA Astrophysics Data System (ADS)

    Ashwal, L. D.; Webb, S. J.; Trumbull, R. B.

    2013-12-01

    The fact that surprising new discoveries can be made in layered mafic intrusions (e.g., subtle 100-150 m cyclicity in apparently homogeneous cumulates over 1000s of m) means that we are still in the first-order characterization phase of understanding these objects. Accordingly, we have secured funding from ICDP for a planning workshop to be held in Johannesburg in early 2014, aimed at scientific drilling of the Bushveld Complex, the world's largest layered mafic intrusion. Science objectives include, but are not limited to: 1. Magma chamber processes & melt evolution. How many melts/magmas/mushes were involved, what were their compositions and how did they interact? What, if anything, is missing from the Complex, and where did it go? Did Bushveld magmatism have an effect upon Earth's atmosphere at 2 Ga? 2. Crust-mantle interactions & origin of Bushveld granitoids. Are Bushveld granites & rhyolites crustal melts, differentiates from the mafic magmas or products of immiscibility? How can the evolved isotopic signatures in the mafic rocks (e.g., epsilon Nd to -8) be understood? 3. Origin of ore deposits. What were the relative roles of gravity settling, magma mixing, immiscibility and hydrothermal fluid transport in producing the PGE, Cr and V deposits? We have identified 3 potential drilling targets representing a total of ~12 km of drill core. Exact locations of drill sites are to be discussed at the workshop. Target A- East-Central Bushveld Complex. We propose 3 overlapping 3 km boreholes that will provide the first roof-to-floor continuous coverage of the Rustenburg Layered Suite. These boreholes will represent a curated, internationally available reference collection of Bushveld material for present and future research. Target B- Southeastern Bushveld Complex. We propose a single borehole of ~2 km depth, collared in Rooiberg felsite, and positioned to intersect the Roof Zone, Upper Zone, Main Zone and floor of the Complex. Amongst other things, this site will

  7. Watching the Creation of Southern California's Largest Reservoir

    NASA Technical Reports Server (NTRS)

    2001-01-01

    The new Diamond Valley Lake Reservoir near the city of Hemet in Riverside County is billed as the largest earthworks construction project in U.S.history. Construction began in 1995 and involved 31 million cubic meters of foundation excavation and 84 million cubic meters of embankment construction. This set of MISR images captures the most recent phase in the reservoir's activation. At the upper left is a natural-color view acquired by the instrument's vertical-viewing (nadir) camera on March 14, 2000 (Terra orbit 1273), shortly after the Metropolitan Water District began filling the reservoir with water from the Colorado River and Northern California. Water appears darker than the surrounding land. The image at the upper right was acquired nearly one year later on March 1, 2001 (Terra orbit 6399), and shows a clear increase in the reservoir's water content. When full, the lake will hold nearly a trillion liters of water.

    According to the Metropolitan Water District, the 7 kilometer x 3 kilometer reservoir nearly doubles Southern California's above-groundwater storage capacity. In addition to routine water management, Diamond Valley Lake is designed to provide protection against drought and a six-month emergency supply in the event of earthquake damage to a major aqueduct. In the face of electrical power shortages, it is also expected to reduce dependence on the pumping of water from northern mountains during the high-demand summer months. An unexpected result of site excavation was the uncovering of mastodon and mammoth skeletons along with bones from extinct species not previously thought to have been indigenous to the area, such as the giant long-horned bison and North American lion. A museum and interpretive center is being built to protect these finds.

    The lower MISR image, from May 20, 2001 (Terra orbit 7564), is a false-color view combining data from the instrument's 26-degree forward view (displayed as blue) with data from the 26-degree backward

  8. Physics-electrical hybrid model for real time impedance matching and remote plasma characterization in RF plasma sources

    SciTech Connect

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

    2016-02-15

    Plasma characterization and impedance matching are an integral part of any radio frequency (RF) based plasma source. In long pulse operation, particularly in high power operation where plasma load may vary due to different reasons (e.g. pressure and power), online tuning of impedance matching circuit and remote plasma density estimation are very useful. In some cases, due to remote interfaces, radio activation and, due to maintenance issues, power probes are not allowed to be incorporated in the ion source design for plasma characterization. Therefore, for characterization and impedance matching, more remote schemes are envisaged. Two such schemes by the same authors are suggested in these regards, which are based on air core transformer model of inductive coupled plasma (ICP) [M. Bandyopadhyay et al., Nucl. Fusion 55, 033017 (2015); D. Sudhir et al., Rev. Sci. Instrum. 85, 013510 (2014)]. However, the influence of the RF field interaction with the plasma to determine its impedance, a physics code HELIC [D. Arnush, Phys. Plasmas 7, 3042 (2000)] is coupled with the transformer model. This model can be useful for both types of RF sources, i.e., ICP and helicon sources.

  9. Physics-electrical hybrid model for real time impedance matching and remote plasma characterization in RF plasma sources.

    PubMed

    Sudhir, Dass; Bandyopadhyay, M; Chakraborty, A

    2016-02-01

    Plasma characterization and impedance matching are an integral part of any radio frequency (RF) based plasma source. In long pulse operation, particularly in high power operation where plasma load may vary due to different reasons (e.g. pressure and power), online tuning of impedance matching circuit and remote plasma density estimation are very useful. In some cases, due to remote interfaces, radio activation and, due to maintenance issues, power probes are not allowed to be incorporated in the ion source design for plasma characterization. Therefore, for characterization and impedance matching, more remote schemes are envisaged. Two such schemes by the same authors are suggested in these regards, which are based on air core transformer model of inductive coupled plasma (ICP) [M. Bandyopadhyay et al., Nucl. Fusion 55, 033017 (2015); D. Sudhir et al., Rev. Sci. Instrum. 85, 013510 (2014)]. However, the influence of the RF field interaction with the plasma to determine its impedance, a physics code HELIC [D. Arnush, Phys. Plasmas 7, 3042 (2000)] is coupled with the transformer model. This model can be useful for both types of RF sources, i.e., ICP and helicon sources.

  10. Physics-electrical hybrid model for real time impedance matching and remote plasma characterization in RF plasma sources

    NASA Astrophysics Data System (ADS)

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

    2016-02-01

    Plasma characterization and impedance matching are an integral part of any radio frequency (RF) based plasma source. In long pulse operation, particularly in high power operation where plasma load may vary due to different reasons (e.g. pressure and power), online tuning of impedance matching circuit and remote plasma density estimation are very useful. In some cases, due to remote interfaces, radio activation and, due to maintenance issues, power probes are not allowed to be incorporated in the ion source design for plasma characterization. Therefore, for characterization and impedance matching, more remote schemes are envisaged. Two such schemes by the same authors are suggested in these regards, which are based on air core transformer model of inductive coupled plasma (ICP) [M. Bandyopadhyay et al., Nucl. Fusion 55, 033017 (2015); D. Sudhir et al., Rev. Sci. Instrum. 85, 013510 (2014)]. However, the influence of the RF field interaction with the plasma to determine its impedance, a physics code HELIC [D. Arnush, Phys. Plasmas 7, 3042 (2000)] is coupled with the transformer model. This model can be useful for both types of RF sources, i.e., ICP and helicon sources.

  11. An electrically driven quantum dot-in-nanowire visible single photon source operating up to 150 K

    NASA Astrophysics Data System (ADS)

    Deshpande, Saniya; Bhattacharya, Pallab

    2013-12-01

    We demonstrate electrically pumped single photon emission up to 150 K from a single InGaN quantum dot embedded in a GaN nanowire junction diode. The InGaN dot-in-nanowire p-n junctions were grown on silicon by molecular beam epitaxy. The exciton electroluminescence from individual dot-in-nanowires is in the green spectral range (λ ˜ 520 nm) and is detectable up to 150 K. Second order autocorrelation measurements performed at the exciton energy at an ambient temperature of 125 K show a background corrected g(2)(0) equal to 0.35, indicating dominant single photon emission. The steady state nanowire temperature under these conditions is estimated to be 150 K due to Joule heating induced by the large nanowire series resistance. Time resolved photoluminescence measurements yield an exciton radiative lifetime of 1.1 ns.

  12. An electrically driven quantum dot-in-nanowire visible single photon source operating up to 150 K

    SciTech Connect

    Deshpande, Saniya; Bhattacharya, Pallab

    2013-12-09

    We demonstrate electrically pumped single photon emission up to 150 K from a single InGaN quantum dot embedded in a GaN nanowire junction diode. The InGaN dot-in-nanowire p-n junctions were grown on silicon by molecular beam epitaxy. The exciton electroluminescence from individual dot-in-nanowires is in the green spectral range (λ ∼ 520 nm) and is detectable up to 150 K. Second order autocorrelation measurements performed at the exciton energy at an ambient temperature of 125 K show a background corrected g{sup (2)}(0) equal to 0.35, indicating dominant single photon emission. The steady state nanowire temperature under these conditions is estimated to be 150 K due to Joule heating induced by the large nanowire series resistance. Time resolved photoluminescence measurements yield an exciton radiative lifetime of 1.1 ns.

  13. Electrical Burns: First Aid

    MedlinePlus

    ... be caused by a number of sources of electricity, such as lightning, stun guns and contact with ... person who has been injured by contact with electricity should be seen by a doctor. Sometimes an ...

  14. An In-Depth Look at Ground Source Heat Pumps and Other Electric Loads in Two GreenMax Homes

    SciTech Connect

    Puttagunta, Srikanth; Shapiro, Carl

    2012-04-01

    Building America research team Consortium for Advanced Residential Buildings (CARB) partnered with WPPI Energy to answer key research questions on in-field performance of ground-source heat pumps and lighting, appliance, and miscellaneous loads (LAMELs) through extensive field monitoring at two WPPI GreenMax demonstration homes in Wisconsin. These two test home evaluations provided valuable data on the true in-field performance of various building mechanical systems and LAMELs.

  15. Afterglows from the largest explosions in the universe

    PubMed Central

    Hartmann, Dieter H.

    1999-01-01

    The distinction of “largest explosions in the universe” has been bestowed on cosmic gamma-ray bursts. Their afterglows are brighter than supernovae and therefore are called hypernovae. Photometry and spectroscopy of these afterglows have provided major breakthroughs in our understanding of this mysterious phenomenon. PMID:10220364

  16. Animals as Our Companions: World's Largest Math Event 6.

    ERIC Educational Resources Information Center

    National Council of Teachers of Mathematics, Inc., Reston, VA.

    The World's Largest Math Event 6 (WLME 6) is the National Council of Teachers of Mathematics' (NCTM) celebration of mathematics and mathematics education and is the highlight of Mathematics Education Month. This year's event, slated for April 28, 2000, features the theme "Animals as Our Companions". This theme encourages students to…

  17. Building Earth's Largest Library: Driving into the Future.

    ERIC Educational Resources Information Center

    Coffman, Steve

    1999-01-01

    Examines the Amazon.com online bookstore as a blueprint for designing the world's largest library. Topics include selection; accessibility and convenience; quality of Web sites and search tools; personalized service; library collection development, including interlibrary loan; library catalogs and catalog records; a circulation system; costs;…

  18. Analysis of human standing balance by largest lyapunov exponent.

    PubMed

    Liu, Kun; Wang, Hongrui; Xiao, Jinzhuang; Taha, Zahari

    2015-01-01

    The purpose of this research is to analyse the relationship between nonlinear dynamic character and individuals' standing balance by the largest Lyapunov exponent, which is regarded as a metric for assessing standing balance. According to previous study, the largest Lyapunov exponent from centre of pressure time series could not well quantify the human balance ability. In this research, two improvements were made. Firstly, an external stimulus was applied to feet in the form of continuous horizontal sinusoidal motion by a moving platform. Secondly, a multiaccelerometer subsystem was adopted. Twenty healthy volunteers participated in this experiment. A new metric, coordinated largest Lyapunov exponent was proposed, which reflected the relationship of body segments by integrating multidimensional largest Lyapunov exponent values. By using this metric in actual standing performance under sinusoidal stimulus, an obvious relationship between the new metric and the actual balance ability was found in the majority of the subjects. These results show that the sinusoidal stimulus can make human balance characteristics more obvious, which is beneficial to assess balance, and balance is determined by the ability of coordinating all body segments.

  19. Analysis of Human Standing Balance by Largest Lyapunov Exponent

    PubMed Central

    Liu, Kun; Wang, Hongrui; Xiao, Jinzhuang; Taha, Zahari

    2015-01-01

    The purpose of this research is to analyse the relationship between nonlinear dynamic character and individuals' standing balance by the largest Lyapunov exponent, which is regarded as a metric for assessing standing balance. According to previous study, the largest Lyapunov exponent from centre of pressure time series could not well quantify the human balance ability. In this research, two improvements were made. Firstly, an external stimulus was applied to feet in the form of continuous horizontal sinusoidal motion by a moving platform. Secondly, a multiaccelerometer subsystem was adopted. Twenty healthy volunteers participated in this experiment. A new metric, coordinated largest Lyapunov exponent was proposed, which reflected the relationship of body segments by integrating multidimensional largest Lyapunov exponent values. By using this metric in actual standing performance under sinusoidal stimulus, an obvious relationship between the new metric and the actual balance ability was found in the majority of the subjects. These results show that the sinusoidal stimulus can make human balance characteristics more obvious, which is beneficial to assess balance, and balance is determined by the ability of coordinating all body segments. PMID:25866500

  20. NAFTA: The World's Largest Trading Zone Turns 20

    ERIC Educational Resources Information Center

    Ferrarini, Tawni Hunt; Day, Stephen

    2014-01-01

    Everyone under the age of 20 who has grown up in North America has lived in the common market created by NAFTA--the North American Free Trade Agreement. In a zone linking the United States, Canada, and Mexico, most goods and investments flow freely across borders to users, consumers, and investors. In 1994, NAFTA created the largest relatively…

  1. NAFTA: The World's Largest Trading Zone Turns 20

    ERIC Educational Resources Information Center

    Ferrarini, Tawni Hunt; Day, Stephen

    2014-01-01

    Everyone under the age of 20 who has grown up in North America has lived in the common market created by NAFTA--the North American Free Trade Agreement. In a zone linking the United States, Canada, and Mexico, most goods and investments flow freely across borders to users, consumers, and investors. In 1994, NAFTA created the largest relatively…

  2. 360 Video Tour of the World’s Largest Laser

    SciTech Connect

    2016-08-15

    Welcome to the National Ignition Facility at Lawrence Livermore National Laboratory, the world’s largest and most energetic laser system. It draws researchers from around the globe for experiments that can’t be conducted anywhere else on Earth. Let’s take a closer look.

  3. The Single Largest Education Donor Comes with Controversy

    ERIC Educational Resources Information Center

    Finkel, Ed

    2012-01-01

    For the last decade, in districts big and small, the Bill & Melinda Gates Foundation has emerged as the largest private funder of educational efforts. This began with an initiative around small schools in the early to mid-2000s, mostly abandoned now, and has gained traction in the past few years in areas such as teacher evaluation, the Common…

  4. Cassini sheds light on Titan's second largest lake, Ligeia Mare

    NASA Astrophysics Data System (ADS)

    Wendel, JoAnna

    2014-04-01

    Saturn's largest moon, Titan, is known for its dense, planet-like atmosphere and large lakes most likely made of methane and ethane. It has been suggested that Titan's atmosphere and surface are a model of early Earth. Since the early 2000s, NASA's Cassini space probe has been unlocking secrets of the distant moon.

  5. The Single Largest Education Donor Comes with Controversy

    ERIC Educational Resources Information Center

    Finkel, Ed

    2012-01-01

    For the last decade, in districts big and small, the Bill & Melinda Gates Foundation has emerged as the largest private funder of educational efforts. This began with an initiative around small schools in the early to mid-2000s, mostly abandoned now, and has gained traction in the past few years in areas such as teacher evaluation, the Common…

  6. The Power of Nature. World's Largest Math Event 5.

    ERIC Educational Resources Information Center

    National Council of Teachers of Mathematics, Inc., Reston, VA.

    The theme of the fifth annual World's Largest Math Event (WLME 5) is "The Power of Nature." This theme encourages students to explore natural forces that affect humankind, including phenomena such as hurricanes, earthquakes, and snowstorms, and the mathematics that underlies their study. The 15 activities for WLMES have been grouped into five…

  7. Diagnostics of underwater electrical wire explosion through a time- and space-resolved hard x-ray source.

    PubMed

    Sheftman, D; Shafer, D; Efimov, S; Gruzinsky, K; Gleizer, S; Krasik, Ya E

    2012-10-01

    A time- and space-resolved hard x-ray source was developed as a diagnostic tool for imaging underwater exploding wires. A ~4 ns width pulse of hard x-rays with energies of up to 100 keV was obtained from the discharge in a vacuum diode consisting of point-shaped tungsten electrodes. To improve contrast and image quality, an external pulsed magnetic field produced by Helmholtz coils was used. High resolution x-ray images of an underwater exploding wire were obtained using a sensitive x-ray CCD detector, and were compared to optical fast framing images. Future developments and application of this diagnostic technique are discussed.

  8. Electrical characterization of a-InGaZnO thin-film transistors with Cu source/drain electrodes

    NASA Astrophysics Data System (ADS)

    Jeong, Jaewook; Jun Lee, Gwang; Kim, Joonwoo; Choi, Byeongdae

    2012-03-01

    We analyzed the effects of Cu source/drain (S/D) electrodes on the performance of a-InGaZnO (a-IGZO) thin-film transistors (TFTs). Owing to the Cu migration, the parasitic resistance was as low as 10 Ω cm with small current transfer length. Based on the transfer characteristics, we found that VDS dependent Cu migration creates donor-like deep and tail states in the sub-bandgap region. The feasibility of Cu S/D electrodes for a-IGZO TFTs using inverter circuits indicates that fabrication of high performance circuits is possible by controlling the Cu electro-migration.

  9. Estimating the power-law distribution of Earth electrical conductivity from low-frequency, controlled-source electromagnetic responses

    NASA Astrophysics Data System (ADS)

    Beskardes, G. D.; Weiss, C. J.; Everett, M. E.

    2017-02-01

    Electromagnetic responses reflect the interaction between applied electromagnetic fields and heterogeneous geoelectrical structures. Quantifying the relationship between multiscale electrical properties and the observed electromagnetic response is therefore important for meaningful geologic interpretation. We present here examples of near-surface electromagnetic responses whose spatial fluctuations appear on all length scales, are repeatable and fractally distributed, supporting the notion of a `rough geology' exhibiting multiscale hierarchical structure. Bounded by end member cases from homogenized isotropic and anisotropic media, we present numerical modelling results of the electromagnetic responses of textured and spatially correlated, stochastic geologic media, demonstrating that the electromagnetic response is a power law distribution, rather than a smooth response polluted with random, incoherent noise as commonly assumed. Our modelling results show that these electromagnetic responses due to spatially correlated geologic textures are examples of fractional Brownian motion. Furthermore, our results suggest that the fractal behaviour of the electromagnetic responses is correlated with degree of the spatial correlation, the contrasts in ground conductivity, and the preferred orientation of small-scale heterogeneity. In addition, the EM responses acquired across a fault zone comprising different lithological units and varying wavelengths of geologic heterogeneity also support our inferences from numerical modelling.

  10. Estimating the power law distribution of Earth electrical conductivity from low-frequency, controlled-source electromagnetic responses

    NASA Astrophysics Data System (ADS)

    Beskardes, G. D.; Weiss, C. J.; Everett, M. E.

    2016-11-01

    Electromagnetic responses reflect the interaction between applied electromagnetic fields and heterogeneous geoelectrical structures. Quantifying the relationship between multiscale electrical properties and the observed electromagnetic response is therefore important for meaningful geologic interpretation. We present here examples of near-surface electromagnetic responses whose spatial fluctuations appear on all length scales, are repeatable and fractally distributed, supporting the notion of a "rough geology" exhibiting multi-scale hierarchical structure. Bounded by end member cases from homogenized isotropic and anisotropic media, we present numerical modeling results of the electromagnetic responses of textured and spatially-correlated, stochastic geologic media, demonstrating that the electromagnetic response is a power law distribution, rather than a smooth response polluted with random, incoherent noise as commonly assumed. Our modeling results show that these electromagnetic responses due to spatially-correlated geologic textures are examples of fractional Brownian motion. Furthermore, our results suggest that the fractal behavior of the electromagnetic responses is correlated with degree of the spatial correlation, the contrasts in ground conductivity, and the preferred orientation of small-scale heterogeneity. In addition, the EM responses acquired across a fault zone comprising different lithological units and varying wavelengths of geologic heterogeneity also support our inferences from numerical modeling.

  11. Transport of ions in presence of induced electric field and electrostatic turbulence - source of ions injected into ring current

    SciTech Connect

    Cladis, J.B.; Francis, W.E.

    1985-01-01

    The transport of ions from the polar ionosphere to the inner magnetosphere during stormtime conditions has been computed using a Monte Carlo diffusion code. The effect of the electrostatic turbulence assumed to be present during the substorm expansion phase was simulated by a process that accelerated the ions stochastically perpendicular to the magnetic field with a diffusion coefficient proportional to the energization rate of the ions by the induced electric field. This diffusion process was continued as the ions were convected from the plasma sheet boundary layer to the double-spiral injection boundary. Inward of the injection boundary, the ions were convected adiabatically. By using as input an O(+) flux of 2.8 x 10 to the 8th per sq cm per s (w greater than 10 eV) and an H(+) flux of 5.5 x 10 to the 8th per sq cm per s (w greater than 0.63 eV), the computed distribution functions of the ions in the ring current were found to be in good agreement, over a wide range in L (4 to 8), with measurements made with the ISEE-1 satellite during a storm. This O(+) flux and a large part of the H(+) flux are consistent with the DE satellite measurements of the polar ionospheric outflow during disturbed times. 19 references.

  12. Transport of ions in presence of induced electric field and electrostatic turbulence - Source of ions injected into ring current

    NASA Technical Reports Server (NTRS)

    Cladis, J. B.; Francis, W. E.

    1985-01-01

    The transport of ions from the polar ionosphere to the inner magnetosphere during stormtime conditions has been computed using a Monte Carlo diffusion code. The effect of the electrostatic turbulence assumed to be present during the substorm expansion phase was simulated by a process that accelerated the ions stochastically perpendicular to the magnetic field with a diffusion coefficient proportional to the energization rate of the ions by the induced electric field. This diffusion process was continued as the ions were convected from the plasma sheet boundary layer to the double-spiral injection boundary. Inward of the injection boundary, the ions were convected adiabatically. By using as input an O(+) flux of 2.8 x 10 to the 8th per sq cm per s (w greater than 10 eV) and an H(+) flux of 5.5 x 10 to the 8th per sq cm per s (w greater than 0.63 eV), the computed distribution functions of the ions in the ring current were found to be in good agreement, over a wide range in L (4 to 8), with measurements made with the ISEE-1 satellite during a storm. This O(+) flux and a large part of the H(+) flux are consistent with the DE satellite measurements of the polar ionospheric outflow during disturbed times.

  13. Transport of ions in presence of induced electric field and electrostatic turbulence - Source of ions injected into ring current

    NASA Technical Reports Server (NTRS)

    Cladis, J. B.; Francis, W. E.

    1985-01-01

    The transport of ions from the polar ionosphere to the inner magnetosphere during stormtime conditions has been computed using a Monte Carlo diffusion code. The effect of the electrostatic turbulence assumed to be present during the substorm expansion phase was simulated by a process that accelerated the ions stochastically perpendicular to the magnetic field with a diffusion coefficient proportional to the energization rate of the ions by the induced electric field. This diffusion process was continued as the ions were convected from the plasma sheet boundary layer to the double-spiral injection boundary. Inward of the injection boundary, the ions were convected adiabatically. By using as input an O(+) flux of 2.8 x 10 to the 8th per sq cm per s (w greater than 10 eV) and an H(+) flux of 5.5 x 10 to the 8th per sq cm per s (w greater than 0.63 eV), the computed distribution functions of the ions in the ring current were found to be in good agreement, over a wide range in L (4 to 8), with measurements made with the ISEE-1 satellite during a storm. This O(+) flux and a large part of the H(+) flux are consistent with the DE satellite measurements of the polar ionospheric outflow during disturbed times.

  14. Brain electric correlates of strong belief in paranormal phenomena: intracerebral EEG source and regional Omega complexity analyses.

    PubMed

    Pizzagalli, D; Lehmann, D; Gianotti, L; Koenig, T; Tanaka, H; Wackermann, J; Brugger, P

    2000-12-22

    The neurocognitive processes underlying the formation and maintenance of paranormal beliefs are important for understanding schizotypal ideation. Behavioral studies indicated that both schizotypal and paranormal ideation are based on an overreliance on the right hemisphere, whose coarse rather than focussed semantic processing may favor the emergence of 'loose' and 'uncommon' associations. To elucidate the electrophysiological basis of these behavioral observations, 35-channel resting EEG was recorded in pre-screened female strong believers and disbelievers during resting baseline. EEG data were subjected to FFT-Dipole-Approximation analysis, a reference-free frequency-domain dipole source modeling, and Regional (hemispheric) Omega Complexity analysis, a linear approach estimating the complexity of the trajectories of momentary EEG map series in state space. Compared to disbelievers, believers showed: more right-located sources of the beta2 band (18.5-21 Hz, excitatory activity); reduced interhemispheric differences in Omega complexity values; higher scores on the Magical Ideation scale; more general negative affect; and more hypnagogic-like reveries after a 4-min eyes-closed resting period. Thus, subjects differing in their declared paranormal belief displayed different active, cerebral neural populations during resting, task-free conditions. As hypothesized, believers showed relatively higher right hemispheric activation and reduced hemispheric asymmetry of functional complexity. These markers may constitute the neurophysiological basis for paranormal and schizotypal ideation.

  15. Bayesian Predictive Distribution for the Magnitude of the Largest Aftershock

    NASA Astrophysics Data System (ADS)

    Shcherbakov, R.

    2014-12-01

    Aftershock sequences, which follow large earthquakes, last hundreds of days and are characterized by well defined frequency-magnitude and spatio-temporal distributions. The largest aftershocks in a sequence constitute significant hazard and can inflict additional damage to infrastructure. Therefore, the estimation of the magnitude of possible largest aftershocks in a sequence is of high importance. In this work, we propose a statistical model based on Bayesian analysis and extreme value statistics to describe the distribution of magnitudes of the largest aftershocks in a sequence. We derive an analytical expression for a Bayesian predictive distribution function for the magnitude of the largest expected aftershock and compute the corresponding confidence intervals. We assume that the occurrence of aftershocks can be modeled, to a good approximation, by a non-homogeneous Poisson process with a temporal event rate given by the modified Omori law. We also assume that the frequency-magnitude statistics of aftershocks can be approximated by Gutenberg-Richter scaling. We apply our analysis to 19 prominent aftershock sequences, which occurred in the last 30 years, in order to compute the Bayesian predictive distributions and the corresponding confidence intervals. In the analysis, we use the information of the early aftershocks in the sequences (in the first 1, 10, and 30 days after the main shock) to estimate retrospectively the confidence intervals for the magnitude of the expected largest aftershocks. We demonstrate by analysing 19 past sequences that in many cases we are able to constrain the magnitudes of the largest aftershocks. For example, this includes the analysis of the Darfield (Christchurch) aftershock sequence. The proposed analysis can be used for the earthquake hazard assessment and forecasting associated with the occurrence of large aftershocks. The improvement in instrumental data associated with early aftershocks can greatly enhance the analysis and

  16. An analysis of the use of magnetic source tomography to measure the spatial distribution of electric current during vacuum arc remelting

    NASA Astrophysics Data System (ADS)

    Nair, Bindu G.; Ward, R. M.

    2009-04-01

    Magnetic source tomography is explored to analyse the distribution of electric current during vacuum arc remelting (VAR). The goal is to use sensors outside the process to deduce the behaviour within. VAR systems having non-axisymmetric distributions of arc current were modelled using a commercial finite element electromagnetic code (Opera 3d), and a database was created from the resulting patterns of magnetic flux predicted to occur outside the crucible. A reconstruction algorithm was developed using constrained nonlinear optimization to estimate the arc current distribution within the process from the magnetic field data outside. The capabilities of this algorithm were studied, and it was found that given sufficiently low noise in the measurement data it was possible to accurately deduce important features of the spatial distribution of the arc current.

  17. Growth and electrical properties of high-quality InGaAsBi thin films using gas source molecular beam epitaxy

    NASA Astrophysics Data System (ADS)

    Zhou, Shuxing; Qi, Ming; Ai, Likun; Wang, Shumin; Xu, Anhuai; Guo, Qi

    2017-03-01

    The effects of Bi flux and In/Ga ratio on Bi incorporation and electrical properties of InGaAsBi grown by gas source molecular beam epitaxy were systematically studied. It is found that use of a low In/Ga ratio has an enhancement effect on the incorporation of Bi and its content increases linearly with Bi flux until reach a saturation. Incorporation of Bi induces p-type dopant that compensates the background electron concentration but does not degrade the electron mobility for the Bi content up to 6.2%. Up to 7.5% of Bi incorporation has been confirmed by Rutherford backscattering spectroscopy (RBS) and a maximum electron mobility of 5600 cm2·V‑1·s‑1 at room temperature was achieved in InGaAsBi with x Bi = 6.2%, which is the highest value reported in InGaAsBi with x Bi > 5%.

  18. Statistics of largest loops in a random walk

    NASA Astrophysics Data System (ADS)

    Ertas, Deniz; Kantor, Yacov

    1997-01-01

    We report further findings on the size distribution of the largest neutral segments in a sequence of N randomly charged monomers [D. Ertaş and Y. Kantor, Phys. Rev. E 53, 846 (1996)]. Upon mapping to one-dimensional random walks (RW's), this corresponds to finding the probability distribution for the size L of the largest segment that returns to its starting position in an N-step RW. We focus primarily on the large N, l=L/N<<1 limit, which exhibits an essential singularity. We establish analytical upper and lower bounds on the probability distribution, and numerically probe the distribution down to l~0.04 (corresponding to probabilities as low as 10-15) using a recursive Monte Carlo algorithm. We also investigate the possibility of singularities at l=1/k for integer k.

  19. Status and ecological effects of the world's largest carnivores.

    PubMed

    Ripple, William J; Estes, James A; Beschta, Robert L; Wilmers, Christopher C; Ritchie, Euan G; Hebblewhite, Mark; Berger, Joel; Elmhagen, Bodil; Letnic, Mike; Nelson, Michael P; Schmitz, Oswald J; Smith, Douglas W; Wallach, Arian D; Wirsing, Aaron J

    2014-01-10

    Large carnivores face serious threats and are experiencing massive declines in their populations and geographic ranges around the world. We highlight how these threats have affected the conservation status and ecological functioning of the 31 largest mammalian carnivores on Earth. Consistent with theory, empirical studies increasingly show that large carnivores have substantial effects on the structure and function of diverse ecosystems. Significant cascading trophic interactions, mediated by their prey or sympatric mesopredators, arise when some of these carnivores are extirpated from or repatriated to ecosystems. Unexpected effects of trophic cascades on various taxa and processes include changes to bird, mammal, invertebrate, and herpetofauna abundance or richness; subsidies to scavengers; altered disease dynamics; carbon sequestration; modified stream morphology; and crop damage. Promoting tolerance and coexistence with large carnivores is a crucial societal challenge that will ultimately determine the fate of Earth's largest carnivores and all that depends upon them, including humans.

  20. Load insensitive electrical device. [power converters for supplying direct current at one voltage from a source at another voltage

    NASA Technical Reports Server (NTRS)

    Schwarz, F. C. (Inventor)

    1974-01-01

    A class of power converters is described for supplying direct current at one voltage from a source at another voltage. It includes a simple passive circuit arrangement of solid-state switches, inductors, and capacitors by which the output voltage of the converter tends to remain constant in spite of changes in load. The switches are sensitive to the current flowing in the circuit and are employed to permit the charging of capacitance devices in accordance with the load requirements. Because solid-state switches (such as SCR's) may be used with relatively high voltage and because of the inherent efficiency of the invention that permits relatively high switching frequencies, power supplies built in accordance with the invention, together with their associated cabling, can be substantially lighter in weight for a given output power level and efficiency of operation than systems of the prior art.

  1. Rare gas record in the largest Apollo 15 rock.

    NASA Technical Reports Server (NTRS)

    Marti, K.; Lightner, B. D.

    1972-01-01

    The results obtained from mass-spectrometry analyses of the noble gases He, Ne, Ar, Kr, and Xe in a 182-mg chip of the largest Apollo 15 rock 15555 are presented. The spallation krypton data indicate a well-shielded location through most of the time during which the rock was exposed to cosmic rays. Gas retention ages are estimated. No evidence for the presence of products from plutonium-244 or iodine-129 was found.

  2. A local Echo State Property through the largest Lyapunov exponent.

    PubMed

    Wainrib, Gilles; Galtier, Mathieu N

    2016-04-01

    Echo State Networks are efficient time-series predictors, which highly depend on the value of the spectral radius of the reservoir connectivity matrix. Based on recent results on the mean field theory of driven random recurrent neural networks, enabling the computation of the largest Lyapunov exponent of an ESN, we develop a cheap algorithm to establish a local and operational version of the Echo State Property.

  3. World's largest TLP moves onto deepwater Norwegian location

    SciTech Connect

    Vielvoye, R.

    1992-05-04

    This paper reports that the world's largest and most sophisticated tension leg platform (TLP) was floated out to Snorre oil field in the Norwegian North Sea last month. The 78,000 ton unit built by Norwegian independent, Sega Petroleum AS, Oslo, was installed in the southern part of block 34/7 and should produce first oil in August, about a month ahead of schedule.

  4. Blueprint of the world`s largest uranium markets

    SciTech Connect

    Bizal, M.R.

    1996-06-01

    This article is a review of two recently released reports: (1) the EURATOM Supply Agency Annual Report for 1995, and (2) the US Energy Information Administration Uranium Industry Annual for 1995. These reports provide myraid information on uranium production, deliveries, contracts, and prices, as well as enrichment market activity during 1995 in the world`s largest nuclear fuel markets: the European Union and the United States.

  5. Rare gas record in the largest Apollo 15 rock.

    NASA Technical Reports Server (NTRS)

    Marti, K.; Lightner, B. D.

    1972-01-01

    The results obtained from mass-spectrometry analyses of the noble gases He, Ne, Ar, Kr, and Xe in a 182-mg chip of the largest Apollo 15 rock 15555 are presented. The spallation krypton data indicate a well-shielded location through most of the time during which the rock was exposed to cosmic rays. Gas retention ages are estimated. No evidence for the presence of products from plutonium-244 or iodine-129 was found.

  6. THE BRIGHTEST CLUSTER GALAXY IN A85: THE LARGEST CORE KNOWN SO FAR

    SciTech Connect

    López-Cruz, O.; Añorve, C.; Ibarra-Medel, H. J.; Birkinshaw, M.; Worrall, D. M.; Barkhouse, W. A.; Torres-Papaqui, J. P.

    2014-11-10

    We have found that the brightest cluster galaxy (BCG) in A85, Holm 15A, displays the largest core known so far. Its cusp radius, r {sub γ} = 4.57 ± 0.06 kpc (4.''26 ± 0.''06), is more than 18 times larger than the mean for BCGs and ≳ 1 kpc larger than A2261-BCG, hitherto the largest-cored BCG. Holm 15A hosts the luminous amorphous radio source 0039-095B and has the optical signature of a LINER. Scaling laws indicate that this core could host a supermassive black hole (SMBH) of mass M {sub •} ∼ (10{sup 9}-10{sup 11}) M {sub ☉}. We suggest that cores this large represent a relatively short phase in the evolution of BCGs, whereas the masses of their associated SBMH might be set by initial conditions.

  7. Measurement of Fine Particles From Mobile and Stationary Sources, and Reducing the Air Conditioner Power Consumption in Hybrid Electric Vehicles

    NASA Astrophysics Data System (ADS)

    Brewer, Eli Henry

    We study the PM2.5and ultrafine exhaust emissions from a new natural gas-fired turbine power facility to better understand air pollution in California. To characterize the emissions from new natural gas turbines, a series of tests were performed on a GE LMS100 gas turbine. These tests included PM2.5 and wet chemical tests for SO2/SO 3 and NH3, as well as ultrafine (less than 100 nm in diameter) particulate matter measurements. The turbine exhaust had an average particle number concentration that was 2.3x103 times higher than ambient air. The majority of these particles were nanoparticles; at the 100 nm size, stack particle concentrations were about 20 times higher than ambient, and increased to 3.9x104 times higher on average in the 2.5 - 3 nm particle size range. This study also found that ammonia emissions were higher than expected, but in compliance with permit conditions. This was possibly due to an ammonia imbalance entering the catalyst, some flue gas bypassing the catalyst, or not enough catalyst volume. SO3 accounted for an average of 23% of the total sulfur oxides emissions measured. Some of the SO3 is formed in the combustion process, it is likely that the majority formed as the SO2 in the combustion products passed across the oxidizing CO catalyst and SCR catalyst. The 100 MW turbine sampled in this study emitted particle loadings similar to those previously measured from turbines in the SCAQMD area, however, the turbine exhaust contained far more particles than ambient air. The power consumed by an air conditioner accounts for a significant fraction of the total power used by hybrid and electric vehicles especially during summer. This study examined the effect of recirculation of cabin air on power consumption of mobile air conditioners both in-lab and on-road. Real time power consumption and vehicle mileage were recorded by an On Board Diagnostic monitor and carbon balance method. Vehicle mileage improved with increased cabin air recirculation. The

  8. The strongest gravitational lenses. III. The order statistics of the largest Einstein radii

    NASA Astrophysics Data System (ADS)

    Waizmann, J.-C.; Redlich, M.; Meneghetti, M.; Bartelmann, M.

    2014-05-01

    Context. The Einstein radius of a gravitational lens is a key characteristic. It encodes information about decisive quantities such as halo mass, concentration, triaxiality, and orientation with respect to the observer. Therefore, the largest Einstein radii can potentially be utilised to test the predictions of the ΛCDM model. Aims: Hitherto, studies have focussed on the single largest observed Einstein radius. We extend those studies by employing order statistics to formulate exclusion criteria based on the n largest Einstein radii and apply these criteria to the strong lensing analysis of 12 MACS clusters at z> 0.5. Methods: We obtain the order statistics of Einstein radii by a Monte Carlo approach, based on the semi-analytic modelling of the halo population on the past lightcone. After sampling the order statistics, we fit a general extreme value distribution to the first-order distribution, which allows us to derive analytic relations for the order statistics of the Einstein radii. Results: We find that the Einstein radii of the 12 MACS clusters are not in conflict with the ΛCDM expectations. Our exclusion criteria indicate that, in order to exhibit tension with the concordance model, one would need to observe approximately twenty Einstein radii with θeff ≳ 30″, ten with θeff ≳ 35″, five with θeff ≳ 42″, or one with θeff ≳ 74″ in the redshift range 0.5 ≤ z ≤ 1.0 on the full sky (assuming a source redshift of zs = 2). Furthermore, we find that, with increasing order, the haloes with the largest Einstein radii are on average less aligned along the line-of-sight and less triaxial. In general, the cumulative distribution functions steepen for higher orders, giving them better constraining power. Conclusions: A framework that allows the individual and joint order distributions of the n-largest Einstein radii to be derived is presented. From a statistical point of view, we do not see any evidence of an Einstein ring problem even for the

  9. Microstructural and Electrical Characterization of Silicon Carbide and Aluminum Nitride Thin Films Grown by Gas-Source Molecular Beam Epitaxy

    NASA Astrophysics Data System (ADS)

    Kern, Richard Scott

    1996-08-01

    Monocrystalline thin films, multilayered heterostructures and solid solutions of silicon carbide (SiC) and aluminum nitride (AlN) have been grown on alpha(6H) -SiC(0001) substrates by gas-source molecular beam epitaxy. Growth mechanisms, defect formation, donor and acceptor doping, metal-insulator-semiconductor diodes, pseudomorphic heterostructures and solid solutions in these materials have been studied. Monocrystalline films of beta(3C) -SiC(111) and alpha(6H)-SiC(0001) have been controllably deposited on the silicon face of 6H-SiC(0001) substrates. Polytype control was achieved via changes in the substrate orientation, substrate temperature and gas phase chemistry. Step flow growth was achieved on vicinal substrates at growth temperatures of at least 1350^circC using the SiH _4-rm C_2H_4 -H_2 system. Step bunching, cubic SiC nucleation and double positioning boundaries were observed at all temperatures when H_2 was removed from the system or the growth was performed at below 1350^circC. In both cases, growth rate was strongly dependent on temperature. Films doped using either a NH_3/H _2 mixture or pure N_2 were n-type; Al, p-type. Uniform, controllable doping levels between 10^{15} and 10^{19} cm ^{-3} were achieved for both polytypes. The measured mobility in the undoped 6H polytype, 434 cm ^2 V^{-1} s ^{-1}, is the highest reported in this polytype. Monocrystalline AlN was deposited using aluminum evaporated from a modified MBE effusion cell and either activated nitrogen derived from a compact electron cyclotron resonance plasma source or ammonia. Growth using each of the nitrogen sources was optimized with respect to substrate temperature, reactant flux and system pressure. In general, very thin films (<=q50 A) grown on vicinal 6H-SiC had a higher defect density than those grown on nominally on-axis substrates due to defect formation at or near the steps on the SiC surface. Full-width half maximum (FWHM) values of the (0002)_ {AlN} X-ray diffraction Bragg

  10. Electrical system architecture

    DOEpatents

    Algrain, Marcelo C.; Johnson, Kris W.; Akasam, Sivaprasad; Hoff, Brian D.

    2008-07-15

    An electrical system for a vehicle includes a first power source generating a first voltage level, the first power source being in electrical communication with a first bus. A second power source generates a second voltage level greater than the first voltage level, the second power source being in electrical communication with a second bus. A starter generator may be configured to provide power to at least one of the first bus and the second bus, and at least one additional power source may be configured to provide power to at least one of the first bus and the second bus. The electrical system also includes at least one power consumer in electrical communication with the first bus and at least one power consumer in electrical communication with the second bus.

  11. DC source assemblies

    DOEpatents

    Campbell, Jeremy B; Newson, Steve

    2013-02-26

    Embodiments of DC source assemblies of power inverter systems of the type suitable for deployment in a vehicle having an electrically grounded chassis are provided. An embodiment of a DC source assembly comprises a housing, a DC source disposed within the housing, a first terminal, and a second terminal. The DC source also comprises a first capacitor having a first electrode electrically coupled to the housing, and a second electrode electrically coupled to the first terminal. The DC source assembly further comprises a second capacitor having a first electrode electrically coupled to the housing, and a second electrode electrically coupled to the second terminal.

  12. Modeling the effects of changes in new source review on national SO{sub 2} and NOx emissions from electricity-generating units

    SciTech Connect

    David A. Evans; Benjamin F. Hobbs; Craig Oren; Karen L. Palmer

    2008-01-15

    The Clean Air Act establishes New Source Review (NSR) programs that apply to construction or modification of major stationary sources. In 2002 and 2003, EPA revised its rules to narrow NSR's coverage of renovations. Congress mandated a National Research Council study of the revisions' impacts. In that study, we used an electricity-sector model to explore possible effects of the equipment replacement provision (ERP), the principal NSR change directed at power plants. We find that, assuming implementation of the Clean Air Interstate Rule (CAIR), tight enforcement of the prerevision NSR rules would likely lead to no or limited decreases in national emissions compared to policies such as ERP. However, emissions might shift forward in time because the previous NSR rules would depress allowance prices, discouraging banking and encouraging allowance use. Only under the most aggressive prerevision NSR enforcement scenario, in which essentially all coal capacity is compelled to retrofit controls by 2020, do NOx emissions fall below ERP levels. Even then, total 2007-2020 SO{sub 2} emissions are unaffected. Further decreases in national emissions could be accomplished more cheaply by tighter emissions caps than through NSR because caps provide incentives for efficient operating strategies, such as fuel switching, as well as retrofits. 23 refs., 2 figs., 1 tab.

  13. Modeling the effects of changes in new source review on national SO2 and NOx emissions from electricity-generating units.

    PubMed

    Evans, David A; Hobbs, Benjamin F; Oren, Craig; Palmer, Karen L

    2008-01-15

    The Clean Air Act establishes New Source Review (NSR) programs that apply to construction or modification of major stationary sources. In 2002 and 2003, EPA revised its rules to narrow NSR's coverage of renovations. Congress mandated a National Research Council study of the revisions' impacts. In that study, we used an electricity-sector model to explore possible effects of the equipment replacement provision (ERP), the principal NSR change directed at power plants. We find that, assuming implementation of the Clean Air Interstate Rule (CAIR), tight enforcement of the prerevision NSR rules would likely lead to no or limited decreases in national emissions compared to policies such as ERP. However, emissions might shift forward in time because the previous NSR rules would depress allowance prices, discouraging banking and encouraging allowance use. Only under the most aggressive prerevision NSR enforcement scenario, in which essentially all coal capacity is compelled to retrofit controls by 2020, do NOx emissions fall below ERP levels. Even then, total 2007-2020 SO2 emissions are unaffected. Further decreases in national emissions could be accomplished more cheaply by tighter emissions caps than through NSR because caps provide incentives for efficient operating strategies, such as fuel switching, as well as retrofits.

  14. Load Frequency Control by use of a Number of Both Heat Pump Water Heaters and Electric Vehicles in Power System with a Large Integration of Renewable Energy Sources

    NASA Astrophysics Data System (ADS)

    Masuta, Taisuke; Shimizu, Koichiro; Yokoyama, Akihiko

    In Japan, from the viewpoints of global warming countermeasures and energy security, it is expected to establish a smart grid as a power system into which a large amount of generation from renewable energy sources such as wind power generation and photovoltaic generation can be installed. Measures for the power system stability and reliability are necessary because a large integration of these renewable energy sources causes some problems in power systems, e.g. frequency fluctuation and distribution voltage rise, and Battery Energy Storage System (BESS) is one of effective solutions to these problems. Due to a high cost of the BESS, our research group has studied an application of controllable loads such as Heat Pump Water Heater (HPWH) and Electric Vehicle (EV) to the power system control for reduction of the required capacity of BESS. This paper proposes a new coordinated Load Frequency Control (LFC) method for the conventional power plants, the BESS, the HPWHs, and the EVs. The performance of the proposed LFC method is evaluated by the numerical simulations conducted on a power system model with a large integration of wind power generation and photovoltaic generation.

  15. Plasma source for spacecraft potential control

    NASA Technical Reports Server (NTRS)

    Olsen, R. C.

    1983-01-01

    A stable electrical ground which enables the particle spectrometers to measure the low energy particle populations was investigated and the current required to neutralize the spacecraft was measured. In addition, the plasma source for potential control (PSPO C) prevents high charging events which could affect the spacecraft electrical integrity. The plasma source must be able to emit a plasma current large enough to balance the sum of all other currents to the spacecraft. In ion thrusters, hollow cathodes provide several amperes of electron current to the discharge chamber. The PSPO C is capable of balancing the net negative currents found in eclipse charging events producing 10 to 100 microamps of electron current. The largest current required is the ion current necessary to balance the total photoelectric current.

  16. Largest separable balls around the maximally mixed bipartite quantum state

    NASA Astrophysics Data System (ADS)

    Gurvits, Leonid; Barnum, Howard

    2002-12-01

    For finite-dimensional bipartite quantum systems, we find the exact size of the largest balls, in spectral lp norms for 1<=p<=∞, of separable (unentangled) matrices around the identity matrix. This implies a simple and intuitively meaningful geometrical sufficient condition for separability of bipartite density matrices: that their purity tr ρ2 not be too large. Theoretical and experimental applications of these results include algorithmic problems such as computing whether or not a state is entangled, and practical ones such as obtaining information about the existence or nature of entanglement in states reached by nuclear magnetic resonance quantum computation implementations or other experimental situations.

  17. Longevity in Calumma parsonii, the World's largest chameleon.

    PubMed

    Tessa, Giulia; Glaw, Frank; Andreone, Franco

    2017-03-01

    Large body size of ectothermic species can be correlated with high life expectancy. We assessed the longevity of the World's largest chameleon, the Parson's chameleon Calumma parsonii from Madagascar by using skeletochronology of phalanges taken from preserved specimens held in European natural history museums. Due to the high bone resorption we can provide only the minimum age of each specimen. The highest minimum age detected was nine years for a male and eight years for a female, confirming that this species is considerably long living among chameleons. Our data also show a strong correlation between snout-vent length and estimated age.

  18. JET, the largest tokamak on the eve of DT operation

    NASA Astrophysics Data System (ADS)

    Horton, L. D.

    2016-11-01

    The Joint European Torus (JET) is the world's largest operating tokamak and the only such machine capable of operating with the fuel mixture (deuterium-tritium) foreseen for a fusion reactor. Since it came into operation in 1983, JET has explored fusion plasmas "in conditions and dimensions approaching those of a fusion reactor" [1]. JET has demonstrated world-record levels of fusion power and energy production, in conditions where the ratio of the fusion power generated to the input power to the plasma, Q, approaches unity.

  19. Largest Lyapunov Exponent for Many Particle Systems at Low Densities

    NASA Astrophysics Data System (ADS)

    van Zon, R.; van Beijeren, H.; Dellago, Ch.

    1998-03-01

    The largest Lyapunov exponent λ+ for a dilute gas with short range interactions in equilibrium is studied by a mapping to a clock model, in which every particle carries a watch, with a discrete time that is advanced at collisions. This model has a propagating front solution with a speed that determines λ+, for which we find a density dependence as predicted by Krylov, but with a larger prefactor. Simulations for the clock model and for hard sphere and hard disk systems confirm these results and are in excellent mutual agreement. They show a slow convergence of λ+ with increasing particle number, in good agreement with a prediction by Brunet and Derrida.

  20. The Largest Fragment of a Homogeneous Fragmentation Process

    NASA Astrophysics Data System (ADS)

    Kyprianou, Andreas; Lane, Francis; Mörters, Peter

    2017-03-01

    We show that in homogeneous fragmentation processes the largest fragment at time t has size e^{-t Φ '(overline{p})}t^{-3/2 (log Φ )'(overline{p})+o(1)}, where Φ is the Lévy exponent of the fragmentation process, and overline{p} is the unique solution of the equation (log Φ )'(bar{p})=1/1+bar{p}. We argue that this result is in line with predictions arising from the classification of homogeneous fragmentation processes as logarithmically correlated random fields.

  1. The global diversion of pharmaceutical drugs. India: the third largest illicit opium producer?

    PubMed

    Paoli, Letizia; Greenfield, Victoria A; Charles, Molly; Reuter, Peter

    2009-03-01

    This paper explores India's role in the world illicit opiate market, particularly its role as a producer. India, a major illicit opiate consumer, is also the sole licensed exporter of raw opium: this unique status may be enabling substantial diversion to the illicit market. Participant observation and interviews were carried out at eight different sites. Information was also drawn from all standard secondary sources and the analysis of about 180 drug-related criminal proceedings reviewed by Indian High Courts and the Supreme Court from 1985 to 2001. Diversion from licit opium production takes place on such a large scale that India may be the third largest illicit opium producer after Afghanistan and Burma. With the possible exceptions of 2005 and 2006, 200-300 tons of India's opium may be diverted yearly. After estimating India's opiate consumption on the basis of UN-reported prevalence estimates, we find that diversion from licit production might have satisfied a quarter to more than a third of India's illicit opiate demand to 2004. India is not only among the world's largest consumer of illicit opiates but also one of the largest illicit opium producers. In contrast to all other illicit producers, India owes the latter distinction not to blatantly illicit cultivation but to diversion from licit cultivation. India's experience suggests the difficulty of preventing substantial leakage, even in a relatively well-governed nation.

  2. Testing a Parachute for Mars in World's Largest Wind Tunnel

    NASA Technical Reports Server (NTRS)

    2007-01-01

    The team developing the landing system for NASA's Mars Science Laboratory tested the deployment of an early parachute design in mid-October 2007 inside the world's largest wind tunnel, at NASA Ames Research Center, Moffett Field, California.

    In this image, two engineers are dwarfed by the parachute, which holds more air than a 280-square-meter (3,000-square-foot) house and is designed to survive loads in excess of 36,000 kilograms (80,000 pounds).

    The parachute, built by Pioneer Aerospace, South Windsor, Connecticut, has 80 suspension lines, measures more than 50 meters (165 feet) in length, and opens to a diameter of nearly 17 meters (55 feet). It is the largest disk-gap-band parachute ever built and is shown here inflated in the test section with only about 3.8 meters (12.5 feet) of clearance to both the floor and ceiling.

    The wind tunnel, which is 24 meters (80 feet) tall and 37 meters (120 feet) wide and big enough to house a Boeing 737, is part of the National Full-Scale Aerodynamics Complex, operated by the U.S. Air Force, Arnold Engineering Development Center.

    NASA's Jet Propulsion Laboratory, Pasadena, California, is building and testing the Mars Science Laboratory spacecraft for launch in 2009. The mission will land a roving analytical laboratory on the surface of Mars in 2010. JPL is a division of the California Institute of Technology.

  3. Mars Parachute Testing in World Largest Wind Tunnel

    NASA Image and Video Library

    2009-04-22

    The parachute for NASA next mission to Mars passed flight-qualification testing in March and April 2009 inside the world largest wind tunnel, at NASA Ames Research Center, Moffett Field, Calif. NASA's Mars Science Laboratory mission, to be launched in 2011 and land on Mars in 2012, will use the largest parachute ever built to fly on an extraterrestrial mission. This image shows a duplicate qualification-test parachute inflated in an 80-mile-per-hour (36-meter-per-second) wind inside the test facility. The parachute uses a configuration called disk-gap-band. It has 80 suspension lines, measures more than 50 meters (165 feet) in length, and opens to a diameter of nearly 16 meters (51 feet). Most of the orange and white fabric is nylon, though a small disk of heavier polyester is used near the vent in the apex of the canopy due to higher stresses there. It is designed to survive deployment at Mach 2.2 in the Martian atmosphere, where it will generate up to 65,000 pounds of drag force. The wind tunnel is 24 meters (80 feet) tall and 37 meters (120 feet) wide, big enough to house a Boeing 737. It is part of the National Full-Scale Aerodynamics Complex, operated by the Arnold Engineering Development Center of the U.S. Air Force. http://photojournal.jpl.nasa.gov/catalog/PIA11995

  4. Orion: The Largest Infrared Hybrid Focal Plane in Production

    NASA Astrophysics Data System (ADS)

    Fowler, Albert M.; Merrill, Michael; Ball, William J.; Henden, Arne A.; Vrba, Frederick J.; McCreight, Craig R.

    2003-03-01

    Orion is a program to develop a 2048x2048 infrared focal plane using InSb PV detectors. It is the natural follow-on to the successful Aladdin 1024x1024 program, which was the largest IR focal plane of the 90's. Although the pixels are somewhat smaller than Aladdin, the overall focal plane is over 50mm in size and for the present is the largest IR focal plane of the 21st century. The work is being done by Raytheon Infrared Operations (RIO but better known as SBRC) by many of the same people who created the Aladdin focal plane. The design is very similar to the successful Aladdin design with the addition of reference pixels to lower noise and drift effects in long integrations. So far we have made five focal plane modules with hybridized InSb detectors. In this paper we will discuss the unique design features of this device as well as present test data taken from these devices.

  5. The largest molecular cloud complexes in the first galactic quadrant

    NASA Technical Reports Server (NTRS)

    Dame, T. M.; Elmegreen, B. G.; Cohen, R. S.; Thaddeus, P.

    1986-01-01

    The Columbia CO survey of the first Galactic quadrant was used to determine the locations and physical properties of the largest molecular complexes in the inner Galaxy. Within the range of the survey (l = 12-60 deg), 26 complexes were detected with masses greater than 5 x 10 to the 5th solar masses, and roughly several hundred such complexes are deduced to exist throughout the Galaxy within the solar circle. These complexes are the parent objects of much of the Population I in the Galaxy. Distances to most of the complexes were determined kinematically, the distance ambiguity being resolved with the aid of associated H II regions, OB associations, masers, and other early Population I objects. The largest complexes are good tracers of spiral structure, the Sagittarius arm in particular being delineated with unprecedented clarity. A total of 17 large complexes are distributed rather uniformly along a 15 kpc stretch of the arm with a spacing comparable to that of the strings of regularly spaced H Ii regions observed in external galaxies. Power-law relations exist between the line widths and sizes of the complexes and between their densities and sizes. The forms of these relations are in good agreement with those found previously and are extended by roughly an order of magnitude in cloud mass.

  6. Testing a Parachute for Mars in World's Largest Wind Tunnel

    NASA Technical Reports Server (NTRS)

    2007-01-01

    The team developing the landing system for NASA's Mars Science Laboratory tested the deployment of an early parachute design in mid-October 2007 inside the world's largest wind tunnel, at NASA Ames Research Center, Moffett Field, California.

    In this image, two engineers are dwarfed by the parachute, which holds more air than a 280-square-meter (3,000-square-foot) house and is designed to survive loads in excess of 36,000 kilograms (80,000 pounds).

    The parachute, built by Pioneer Aerospace, South Windsor, Connecticut, has 80 suspension lines, measures more than 50 meters (165 feet) in length, and opens to a diameter of nearly 17 meters (55 feet). It is the largest disk-gap-band parachute ever built and is shown here inflated in the test section with only about 3.8 meters (12.5 feet) of clearance to both the floor and ceiling.

    The wind tunnel, which is 24 meters (80 feet) tall and 37 meters (120 feet) wide and big enough to house a Boeing 737, is part of the National Full-Scale Aerodynamics Complex, operated by the U.S. Air Force, Arnold Engineering Development Center.

    NASA's Jet Propulsion Laboratory, Pasadena, California, is building and testing the Mars Science Laboratory spacecraft for launch in 2009. The mission will land a roving analytical laboratory on the surface of Mars in 2010. JPL is a division of the California Institute of Technology.

  7. Fishing down the largest coral reef fish species.

    PubMed

    Fenner, Douglas

    2014-07-15

    Studies on remote, uninhabited, near-pristine reefs have revealed surprisingly large populations of large reef fish. Locations such as the northwestern Hawaiian Islands, northern Marianas Islands, Line Islands, U.S. remote Pacific Islands, Cocos-Keeling Atoll and Chagos archipelago have much higher reef fish biomass than islands and reefs near people. Much of the high biomass of most remote reef fish communities lies in the largest species, such as sharks, bumphead parrots, giant trevally, and humphead wrasse. Some, such as sharks and giant trevally, are apex predators, but others such as bumphead parrots and humphead wrasse, are not. At many locations, decreases in large reef fish species have been attributed to fishing. Fishing is well known to remove the largest fish first, and a quantitative measure of vulnerability to fishing indicates that large reef fish species are much more vulnerable to fishing than small fish. The removal of large reef fish by fishing parallels the extinction of terrestrial megafauna by early humans. However large reef fish have great value for various ecological roles and for reef tourism.

  8. Electrical properties of schist and mylonite from the South Island, New Zealand: Exploring the source of the Southern Alps Anomalous Conductor

    NASA Astrophysics Data System (ADS)

    Kluge, Katherine; Toy, Virginia; Ohneiser, Chrisitan; Lockner, David

    2017-04-01

    The Southern Alps Electrical Conductor (SAC), identified from magnetotelluric surveys of the South Island Geophysical Transect (SIGHT) in the South Island, New Zealand, has high electrical conductivity relative to surrounding lithology (0.1 to 1 S/m between 5 and 25 km depth). This phenomenon is spatially coincident with shear zones of the Alpine Fault transform boundary and a region of anomalously low seismic velocity. It has been suggested these geophysical anomalies indicate dynamically linked fluids or graphite networks at depth, but this is unconfirmed. The convergent component of deformation within the Southern Alps orogen exhumes the lower crust. Because of this, we have been able to examine the relationship between electric properties, porosities, and mineral arrangement of hanging wall rock samples across metamorphic and strain gradients approaching the Alpine Fault. These allow us to constrain the roc properties which yield the source of the Southern Alps Electrical Conductor. We measured the electrical properties of 7 hand samples at the USGS Rock Physics Lab in Menlo Park, California. Complex resistivity of samples under confining pressure was measured up to 200 MPa, with a saturating brine of 0.1 M KCl. Laboratory measurements were then converted to complex conductivity. Mylonite conductivities were also averaged at each confining pressure and extrapolated to Alpine Fault conditions at depth (using fluid conductivity, geothermal gradient and effective confining pressure) to find projected in situ values between 0 and 9.4 km depth. Porosity ranges from 1.2 to 5.4% for hanging wall metamorphic schists and 1.0 to 1.9% for Alpine Fault Zone mylonites. Schist porosity substantially decreases with increasing proximity to the Alpine Fault, but mylonite porosity exhibits no systematic trend. Conductivity at 5 MPa effective confining pressure and 20 Hz ranges from 9.70x10-5 to 2.23x10-3 S/m for schists and 1.48x10-3 to 4.33x10-3 S/m for mylonites. Schist

  9. Lending a Hand: A Report on the Lobbying Expenditures and Political Contributions of the Five Largest Student Loan Corporations.

    ERIC Educational Resources Information Center

    United States Public Interest Research Group, Washington, DC.

    Using data from a variety of sources, including public records and the Web site of the Center for Responsive Politics, this study examined the political spending of the five largest holders of federally subsidized student loans: Sallie Mae, the Student Loan Corporation of Citibank, First Union National Bank, Wells Fargo Education Financial…

  10. Sources and characteristics of carbonaceous aerosol in two largest cities in Pearl River Delta Region, China

    NASA Astrophysics Data System (ADS)

    Duan, Jingchun; Tan, Jihua; Cheng, Dingxi; Bi, Xinhui; Deng, Wenjing; Sheng, Guoying; Fu, Jiamo; Wong, M. H.

    PM 2.5 samples were collected at five sites in Guangzhou and Hong Kong, Pearl River Delta Region (PRDR), China in both summer and winter during 2004-2005. Elemental carbon (EC) and organic carbon (OC) in these samples were measured. The OC and EC concentrations ranked in the order of urban Guangzhou > urban Hong Kong > background Hong Kong. Total carbonaceous aerosol (TCA) contributed less to PM 2.5 in urban Guangzhou (32-35%) than that in urban Hong Kong (43-57%). The reason may be that, as an major industrial city in South China, Guangzhou would receive large amount of inorganic aerosol from all kinds of industries, however, as a trade center and seaport, urban Hong Kong would mainly receive organic aerosol and EC from container vessels and heavy-duty diesel trucks. At Hong Kong background site Hok Tsui, relatively lower contribution of TCA to PM 2.5 may result from contributions of marine inorganic aerosol and inland China pollutant. Strong correlation ( R2=0.76-0.83) between OC and EC indicates minor fluctuation of emission and the secondary organic aerosol (SOA) formation in urban Guangzhou. Weak correlation between OC and EC in Hong Kong can be related to the impact of the long-range transported aerosol from inland China. Averagely, secondary OC (SOC) concentrations were 3.8-5.9 and 10.2-12.8 μg m -3, respectively, accounting for 21-32% and 36-42% of OC in summer and winter in Guangzhou. The average values of 4.2-6.8% for SOA/ PM 2.5 indicate that SOA was minor component in PM 2.5 in Guangzhou.

  11. Characteristics and ship traffic source identification of air pollutants in China's largest port

    NASA Astrophysics Data System (ADS)

    Zhao, Minjiang; Zhang, Yan; Ma, Weichun; Fu, Qingyan; Yang, Xin; Li, Chunlei; Zhou, Bin; Yu, Qi; Chen, Limin

    2013-01-01

    To characterize the air pollutants in Shanghai Port and identify the contribution from ship traffic emission, field measurements have been conducted in 2011. The trace gases SO2, NO2 and O3 were monitored and aerosol samples of TSP, PM2.5 and size-segregated particles were collected in a working area of Shanghai Port. Elements including V, Ni, Al, Fe, Si, Ca, Na, Mg, Mn, Zn, Co, Cr in aerosol samples and heavy fuel oil samples were analyzed. The results revealed that average hourly SO2 and NO2 concentrations in Shanghai Port were respectively 29.4 and 63.7 μg m-3, average daily concentrations of TSP and PM2.5 were 114.39 and 62.60 μg m-3, comparable with the ones in Shanghai land area. Ni and V were found enriched in fine particles with averaged concentrations of 80.0 and 14.8 ng m-3 in PM2.5 respectively. Also ratio of V/Ni in aerosol under summertime airflow was 3.4, very close to the ratio of averaged V and Ni content in international heavy fuel oils used in Shanghai Port. The backward trajectory analysis further revealed that SO2, NO2, and V under coastal airflows were mainly from ship traffic emission. The mean concentration of V was 15.84 ng m-3 under hybrid coastal airflows, much higher than that of 9.84 ng m-3 under continental airflows. Furthermore, V was found to be highly correlated with ship fluxes, and was selected as an indicator of ship traffic emission in Shanghai. The estimated primary PM2.5 contribution from ship traffic ranged from 0.63 to 3.58 μg m-3, with an average of 1.96 μg m-3. This PM2.5 fraction accounted for 4.23% of the total PM2.5 in an average level, and reached to a maximum of 12.8%. Furthermore, there could be 64% of primary PM2.5 contributed by ships in Shanghai Port transported to inland region. Our results suggest that ship traffic has a non-negligible contribution on ambient levels of fine particles and secondary contribution of SO2 and NO2 emitted by ships need to be estimated on local and regional scale in future.

  12. In Search of the Largest Possible Tsunami: An Example Following the 2011 Japan Tsunami

    NASA Astrophysics Data System (ADS)

    Geist, E. L.; Parsons, T.

    2012-12-01

    Many tsunami hazard assessments focus on estimating the largest possible tsunami: i.e., the worst-case scenario. This is typically performed by examining historic and prehistoric tsunami data or by estimating the largest source that can produce a tsunami. We demonstrate that worst-case assessments derived from tsunami and tsunami-source catalogs are greatly affected by sampling bias. Both tsunami and tsunami sources are well represented by a Pareto distribution. It is intuitive to assume that there is some limiting size (i.e., runup or seismic moment) for which a Pareto distribution is truncated or tapered. Likelihood methods are used to determine whether a limiting size can be determined from existing catalogs. Results from synthetic catalogs indicate that several observations near the limiting size are needed for accurate parameter estimation. Accordingly, the catalog length needed to empirically determine the limiting size is dependent on the difference between the limiting size and the observation threshold, with larger catalog lengths needed for larger limiting-threshold size differences. Most, if not all, tsunami catalogs and regional tsunami source catalogs are of insufficient length to determine the upper bound on tsunami runup. As an example, estimates of the empirical tsunami runup distribution are obtained from the Miyako tide gauge station in Japan, which recorded the 2011 Tohoku-oki tsunami as the largest tsunami among 51 other events. Parameter estimation using a tapered Pareto distribution is made both with and without the Tohoku-oki event. The catalog without the 2011 event appears to have a low limiting tsunami runup. However, this is an artifact of undersampling. Including the 2011 event, the catalog conforms more to a pure Pareto distribution with no confidence in estimating a limiting runup. Estimating the size distribution of regional tsunami sources is subject to the same sampling bias. Physical attenuation mechanisms such as wave breaking

  13. Electric fluid pump

    DOEpatents

    Van Dam, Jeremy Daniel; Turnquist, Norman Arnold; Raminosoa, Tsarafidy; Shah, Manoj Ramprasad; Shen, Xiaochun

    2015-09-29

    An electric machine is presented. The electric machine includes a hollow rotor; and a stator disposed within the hollow rotor, the stator defining a flow channel. The hollow rotor includes a first end portion defining a fluid inlet, a second end portion defining a fluid outlet; the fluid inlet, the fluid outlet, and the flow channel of the stator being configured to allow passage of a fluid from the fluid inlet to the fluid outlet via the flow channel; and wherein the hollow rotor is characterized by a largest cross-sectional area of hollow rotor, and wherein the flow channel is characterized by a smallest cross-sectional area of the flow channel, wherein the smallest cross-sectional area of the flow channel is at least about 25% of the largest cross-sectional area of the hollow rotor. An electric fluid pump and a power generation system are also presented.

  14. Hubble Catches Jupiter's Largest Moon Going to the 'Dark Side'

    NASA Image and Video Library

    2017-09-28

    Hubble Catches Jupiter's Largest Moon Going to the 'Dark Side' HST/WFPC2 Image of Jupiter and Ganymede Taken April 9, 2007 NASA's Hubble Space Telescope has caught Jupiter's moon Ganymede playing a game of "peek-a-boo." In this crisp Hubble image, Ganymede is shown just before it ducks behind the giant planet. Ganymede completes an orbit around Jupiter every seven days. Because Ganymede's orbit is tilted nearly edge-on to Earth, it routinely can be seen passing in front of and disappearing behind its giant host, only to reemerge later. Composed of rock and ice, Ganymede is the largest moon in our solar system. It is even larger than the planet Mercury. But Ganymede looks like a dirty snowball next to Jupiter, the largest planet in our solar system. Jupiter is so big that only part of its Southern Hemisphere can be seen in this image. Hubble's view is so sharp that astronomers can see features on Ganymede's surface, most notably the white impact crater, Tros, and its system of rays, bright streaks of material blasted from the crater. Tros and its ray system are roughly the width of Arizona. The image also shows Jupiter's Great Red Spot, the large eye-shaped feature at upper left. A storm the size of two Earths, the Great Red Spot has been raging for more than 300 years. Hubble's sharp view of the gas giant planet also reveals the texture of the clouds in the Jovian atmosphere as well as various other storms and vortices. Astronomers use these images to study Jupiter's upper atmosphere. As Ganymede passes behind the giant planet, it reflects sunlight, which then passes through Jupiter's atmosphere. Imprinted on that light is information about the gas giant's atmosphere, which yields clues about the properties of Jupiter's high-altitude haze above the cloud tops. This color image was made from three images taken on April 9, 2007, with the Wide Field Planetary Camera 2 in red, green, and blue filters. The image shows Jupiter and Ganymede in close to natural colors. For

  15. Earth's Largest Meteorite Impact Craters discovered in South America?

    NASA Astrophysics Data System (ADS)

    Kellndorfer, J. M.; Schmidt-Falkenberg, H.

    2014-12-01

    Novel analysis of high resolution InSAR-based digital elevation data from the year 2001 Shuttle Radar Topography Mission combined with a recently produced dataset of pan-tropical vegetation height from ALOS-1 SAR and IceSAT/GLAS Lidar estimates led to the quasi-bald-Earth discovery of four sizable near-perfect circle arcs in South America under dense tropical forests ranging in length from 216 km to 441 km. Terrain elevation profiles of cross-sections across the arcs show a distinct vertical rising and falling in elevations of hundreds of meters over a horizontal distance of tens of kilometers. It is hypothesized that these sizable arcs and associated rim-like topographic terrain features are remnants of huge meteorite impact craters with diameters ranging from 770 km to 1,310 km, thus forming potentially the largest known impact carter structures discovered on Earth today. The potential impact crater rim structures are located north of the eastern Amazon River, in the coastal region of Recife and Natal, and in the Brazilian, Bolivian and Paraguayan border region encompassing the Pantanal. Elevation profiles, hillshades and gray-shaded elevation maps were produced to support the geomorphologic analysis. It is also speculated whether in three of the four potential impact craters, central uplift domes or peaks, which are typical for complex impact crater structures can be identified. The worlds largest iron ore mining area of Carajás in Para, Brazil, falls exactly in the center of the largest hypothesized circular impact crater showing topographic elevations similar to the rim structure discovered 655 km to the north-north-west. Based on the topographic/geomorphologic driven hypothesis, geologic exploration of these topographic features is needed to test whether indeed meteorite impact craters could be verified, what the more exact ellipsoidal shapes of the potential impact craters might be, and to determine when during geologic times the impacts would have taken

  16. Intense fusion neutron sources

    NASA Astrophysics Data System (ADS)

    Kuteev, B. V.; Goncharov, P. R.; Sergeev, V. Yu.; Khripunov, V. I.

    2010-04-01

    The review describes physical principles underlying efficient production of free neutrons, up-to-date possibilities and prospects of creating fission and fusion neutron sources with intensities of 1015-1021 neutrons/s, and schemes of production and application of neutrons in fusion-fission hybrid systems. The physical processes and parameters of high-temperature plasmas are considered at which optimal conditions for producing the largest number of fusion neutrons in systems with magnetic and inertial plasma confinement are achieved. The proposed plasma methods for neutron production are compared with other methods based on fusion reactions in nonplasma media, fission reactions, spallation, and muon catalysis. At present, intense neutron fluxes are mainly used in nanotechnology, biotechnology, material science, and military and fundamental research. In the near future (10-20 years), it will be possible to apply high-power neutron sources in fusion-fission hybrid systems for producing hydrogen, electric power, and technological heat, as well as for manufacturing synthetic nuclear fuel and closing the nuclear fuel cycle. Neutron sources with intensities approaching 1020 neutrons/s may radically change the structure of power industry and considerably influence the fundamental and applied science and innovation technologies. Along with utilizing the energy produced in fusion reactions, the achievement of such high neutron intensities may stimulate wide application of subcritical fast nuclear reactors controlled by neutron sources. Superpower neutron sources will allow one to solve many problems of neutron diagnostics, monitor nano-and biological objects, and carry out radiation testing and modification of volumetric properties of materials at the industrial level. Such sources will considerably (up to 100 times) improve the accuracy of neutron physics experiments and will provide a better understanding of the structure of matter, including that of the neutron itself.

  17. A Comparison of Independent Component Analysis (ICA) of fMRI and Electrical Source Imaging (ESI) in Focal Epilepsy Reveals Misclassification Using a Classifier.

    PubMed

    Maziero, Danilo; Sturzbecher, Marcio; Velasco, Tonicarlo Rodrigues; Rondinoni, Carlo; Castellanos, Agustin Lage; Carmichael, David William; Salmon, Carlos Ernesto Garrido

    2015-11-01

    Interictal epileptiform discharges (IEDs) can produce haemodynamic responses that can be detected by electroencephalography-functional magnetic resonance imaging (EEG-fMRI) using different analysis methods such as the general linear model (GLM) of IEDs or independent component analysis (ICA). The IEDs can also be mapped by electrical source imaging (ESI) which has been demonstrated to be useful in presurgical evaluation in a high proportion of cases with focal IEDs. ICA advantageously does not require IEDs or a model of haemodynamic responses but its use in EEG-fMRI of epilepsy has been limited by its ability to separate and select epileptic components. Here, we evaluated the performance of a classifier that aims to filter all non-BOLD responses and we compared the spatial and temporal features of the selected independent components (ICs). The components selected by the classifier were compared to those components selected by a strong spatial correlation with ESI maps of IED sources. Both sets of ICs were subsequently compared to a temporal model derived from the convolution of the IEDs (derived from the simultaneously acquired EEG) with a standard haemodynamic response. Selected ICs were compared to the patients' clinical information in 13 patients with focal epilepsy. We found that the misclassified ICs clearly related to IED in 16/25 cases. We also found that the classifier failed predominantly due to the increased spectral range of fMRIs temporal responses to IEDs. In conclusion, we show that ICA can be an efficient approach to separate responses related to epilepsy but that contemporary classifiers need to be retrained for epilepsy data. Our findings indicate that, for ICA to contribute to the analysis of data without IEDs to improve its sensitivity, classification strategies based on data features other than IC time course frequency is required.

  18. Application of the EEMD method for distinction and suppression of motion-induced noise in grounded electrical source airborne TEM system

    NASA Astrophysics Data System (ADS)

    Liu, Fubo; Li, Jutao; Liu, Lihua; Huang, Ling; Fang, Guangyou

    2017-04-01

    Airborne electromagnetic (AEM) detection is an important method for obtaining subsurface conductivity distribution. However, the response of observation system includes not only the underground media response but also a variety of noise components. The motion-induced noise is one of the main noise sources of the airborne electromagnetic data, which has a low frequency, large amplitude, non-periodic and other characteristics. In this paper, we will introduce the principle of the ensemble empirical mode decomposition (EEMD) method and use it for decomposing electromagnetic signal of grounded electrical source airborne transient electromagnetic system. The EEMD method will decompose the electromagnetic signal into multi-stage intrinsic mode function (IMF) components and distinguish the IMF component containing the motion-induced noise. Then we can get the noise-free signal by reconstructing remaining IMF components and residual component. We use the EEMD method for the theoretical signal correction and compared with the cubic spline method, the correction result indicates that the EEMD method can fit the motion-induced noise more accurately with a higher signal-to-noise ratio. To verify the effect of the application of the EEMD method, we went to Weifang city, Shandong province, East China, for the concealed fault investigation. The correction result of the time series shows that the EEMD method can suppress the motion-induced noise more effectively than the cubic spline method. Compared with the uncorrected data and the corrected data using the cubic spline method, the result shows that the fake anomaly can be nearly avoided and a more clear geological structure can be obtained through the corrected data with EEMD method. The results also prove that the EEMD method is a practical as well as effective method for the motion-induced noise suppression.

  19. The depths of the largest impact craters on Venus

    NASA Technical Reports Server (NTRS)

    Ivanov, B. A.; Ford, P. G.

    1993-01-01

    The largest impact craters on Venus may be used as evidence of various geological processes within the Venusian crust. We are continuing to construct a data base for the further investigation of large craters on Venus (LCV). We hope to find evidence of crater relaxation that might constrain the thickness and thermal gradient of the crust, as was proposed in an earlier work. The current work concentrates on 27 impact craters with diameters (d) larger than 70 km, i.e., large enough that the footprint of the Magellan altimeter has a good chance of sampling the true crater bottom. All altimeter echoes from points located within (d/2)+70 km from the crater center have been inspected.

  20. The largest Silurian vertebrate and its palaeoecological implications

    PubMed Central

    Choo, Brian; Zhu, Min; Zhao, Wenjin; Jia, Liaotao; Zhu, You'an

    2014-01-01

    An apparent absence of Silurian fishes more than half-a-metre in length has been viewed as evidence that gnathostomes were restricted in size and diversity prior to the Devonian. Here we describe the largest pre-Devonian vertebrate (Megamastax amblyodus gen. et sp. nov.), a predatory marine osteichthyan from the Silurian Kuanti Formation (late Ludlow, ~423 million years ago) of Yunnan, China, with an estimated length of about 1 meter. The unusual dentition of the new form suggests a durophagous diet which, combined with its large size, indicates a considerable degree of trophic specialisation among early osteichthyans. The lack of large Silurian vertebrates has recently been used as constraint in palaeoatmospheric modelling, with purported lower oxygen levels imposing a physiological size limit. Regardless of the exact causal relationship between oxygen availability and evolutionary success, this finding refutes the assumption that pre-Emsian vertebrates were restricted to small body sizes. PMID:24921626

  1. Correlates of species richness in the largest Neotropical amphibian radiation

    PubMed Central

    Gonzalez-Voyer, A; Padial, J M; Castroviejo-Fisher, S; De La Riva, I; Vilà, C

    2011-01-01

    Although tropical environments are often considered biodiversity hotspots, it is precisely in such environments where least is known about the factors that drive species richness. Here, we use phylogenetic comparative analyses to study correlates of species richness for the largest Neotropical amphibian radiation: New World direct-developing frogs. Clade-age and species richness were nonsignficantly, negatively correlated, suggesting that clade age alone does not explain among-clade variation in species richness. A combination of ecological and morphological traits explained 65% of the variance in species richness. A more vascularized ventral skin, the ability to colonize high-altitude ranges, encompassing a large variety of vegetation types, correlated significantly with species richness, whereas larger body size was marginally correlated with species richness. Hence, whereas high-altitude ranges play a role in shaping clade diversity in the Neotropics, intrinsic factors, such as skin structures and possibly body size, might ultimately determine which clades are more speciose than others. PMID:21401771

  2. Giant fibroepithelial stromal polyp of the vulva: largest case reported

    PubMed Central

    2013-01-01

    Background Fibroepithelial stromal polyps are site-specific mesenchymal lesions that are commonly found in the vulvovaginal region in premenopausal females. These polyps usually are less than 5 cm in diameter and are most commonly identified during routine gynecological examination. Although the stromal polyp is benign, its differential diagnosis includes some malignant vulva lesions making it critical to ensure that an accurate pathologic diagnosis is made. Case We present a case of a 21 year old female with a giant fibroepithelial stromal polyp of the vulva. Upon review of the literature this is the largest reported fibroepithelial stromal polyp to date. Conclusion Fibroepithelial stromal polyps can grow as large as 390 grams and can be 18.5-cm in diameter. Microscopic evaluation of the polyp is critical in the exclusion of malignancy with this diagnosis. PMID:23842282

  3. 1. Photocopy of undated wash drawing. The largest building is ...

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

    1. Photocopy of undated wash drawing. The largest building is the Hotel Williams. Next to it is the Williams House (Williams Hotel Annex), HABS No. MI-258 A. Below them are the log cabins built by the American Fur Company (from left to right): Log Building No. 1 (MI-258 C), Log Building No. 2 (MI-258 D), Log Building No. 3 (not documented), Log Building No. 4 (MI-258 E), and Log Building No. 5 (MI-258 F). (Williams Log House, MI-258 B, and Log Building No. 8, MI-258 G, are not shown). The drawing is in the collection of the Michigan Historical Commission. Although it does not have a date, it was painted in the early 20th century after the main building was constructed. - Hotel Williams, Murray Bay, Munising, Alger County, MI

  4. Opportunities for biodiversity gains under the world's largest reforestation programme

    PubMed Central

    Hua, Fangyuan; Wang, Xiaoyang; Zheng, Xinlei; Fisher, Brendan; Wang, Lin; Zhu, Jianguo; Tang, Ya; Yu, Douglas W.; Wilcove, David S.

    2016-01-01

    Reforestation is a critical means of addressing the environmental and social problems of deforestation. China's Grain-for-Green Program (GFGP) is the world's largest reforestation scheme. Here we provide the first nationwide assessment of the tree composition of GFGP forests and the first combined ecological and economic study aimed at understanding GFGP's biodiversity implications. Across China, GFGP forests are overwhelmingly monocultures or compositionally simple mixed forests. Focusing on birds and bees in Sichuan Province, we find that GFGP reforestation results in modest gains (via mixed forest) and losses (via monocultures) of bird diversity, along with major losses of bee diversity. Moreover, all current modes of GFGP reforestation fall short of restoring biodiversity to levels approximating native forests. However, even within existing modes of reforestation, GFGP can achieve greater biodiversity gains by promoting mixed forests over monocultures; doing so is unlikely to entail major opportunity costs or pose unforeseen economic risks to households. PMID:27598524

  5. The 260: The Largest Solid Rocket Motor Ever Tested

    NASA Technical Reports Server (NTRS)

    Crimmins, P.; Cousineau, M.; Rogers, C.; Shell, V.

    1999-01-01

    Aerojet in the mid 1960s, under contract to NASA, built and static hot fire tested the largest solid rocket motor (SRM) in history for the purpose of demonstrating the feasibility of utilizing large SRMs for space exploration. This program successfully fabricated two high strength steel chambers, loaded each with approximately 1,68 million pounds of propellant, and static test fired these giants with their nozzles up from an underground silo located adjacent to the Florida everglades. Maximum thrust and total impulse in excess of 5,000,000 lbf and 3,470,000,000 lbf-sec were achieved. Flames from the second firing, conducted at night, were seen over eighty miles away. For comparative purposes: the thrust developed was nearly 100 times that of a Minuteman III second stage and the 260 in.-dia cross-section was over 3 times that of the Space Shuttle SRM.

  6. Opportunities for biodiversity gains under the world's largest reforestation programme.

    PubMed

    Hua, Fangyuan; Wang, Xiaoyang; Zheng, Xinlei; Fisher, Brendan; Wang, Lin; Zhu, Jianguo; Tang, Ya; Yu, Douglas W; Wilcove, David S

    2016-09-06

    Reforestation is a critical means of addressing the environmental and social problems of deforestation. China's Grain-for-Green Program (GFGP) is the world's largest reforestation scheme. Here we provide the first nationwide assessment of the tree composition of GFGP forests and the first combined ecological and economic study aimed at understanding GFGP's biodiversity implications. Across China, GFGP forests are overwhelmingly monocultures or compositionally simple mixed forests. Focusing on birds and bees in Sichuan Province, we find that GFGP reforestation results in modest gains (via mixed forest) and losses (via monocultures) of bird diversity, along with major losses of bee diversity. Moreover, all current modes of GFGP reforestation fall short of restoring biodiversity to levels approximating native forests. However, even within existing modes of reforestation, GFGP can achieve greater biodiversity gains by promoting mixed forests over monocultures; doing so is unlikely to entail major opportunity costs or pose unforeseen economic risks to households.

  7. Collapse of the world’s largest herbivores

    PubMed Central

    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

    2015-01-01

    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

  8. Spitzer/IRAC Photometry Of The Four Largest Uranian Satellites

    NASA Astrophysics Data System (ADS)

    Cartwright, Richard; Emery, J.; Rivkin, A.; Trilling, D.

    2012-10-01

    The surfaces of the four largest Uranian satellites are dominated by water ice and a spectrally neutral constituent that is likely carbonaceous in composition. CO2 ice has been detected on Ariel, Umbriel, and Titania, with no detection on the furthest regular Uranian satellite, Oberon (Grundy et al., 2003, 2006). Whether CO2 ice is primordial or is actively produced in the Uranian system is unclear; however, it seems unlikely that primordial CO2 ice would remain exposed on an icy satellite surface over the age of the Solar System. One possible mechanism for producing CO2 ice is bombardment of water ice and carbonaceous material by charged particles caught in Uranus’ magnetic field. Unlike the other large Uranian satellites, Oberon spends part of its orbit outside the confines of Uranus’ magnetic field, which might help explain why CO2 ice has yet to be detected on Oberon. We are using photometric data gathered by the Infrared Array Camera (IRAC), onboard the Spitzer Space Telescope (SST), in order to search for the signature of CO2 ice on Oberon, and confirm its presence on Ariel, Umbriel, and Titania at longer wavelengths than previous studies. IRAC collects data in four different channels, which are centered roughly at 3.6, 4.5, 5.8, and 8.0 µm. Additionally, we are gathering spectroscopic data using SpeX on IRTF, at similar longitudes to the IRAC observations, in order to characterize the distribution of CO2 ice on these icy satellites over a wide range of near-infrared wavelengths. Our preliminary photometry results for Oberon indicate that there is a steep reduction in reflected solar flux from channel 1 to channel 2, suggesting that surface materials are absorbing photons at wavelengths within the bandpass of channel 2. We will present the results of our photometric analysis of the four largest Uranian moons.

  9. Supergranulation as the Sun's largest buoyantly driven mode of convection

    NASA Astrophysics Data System (ADS)

    Cossette, Jean-Francois; Rast, Mark

    2016-05-01

    Solar supergranulation has been characterized as horizontally divergent flow motions having a typical scale of 32 Mm using Doppler imaging, granule tracking and helioseismology. Unlike granules, the size of which is comparable to both the thickness of the radiative boundary layer and local scale height at the photosphere, supergranules do not appear to correspond to any particular length scale of the flow. Possible explanations ranging from convection theories involving Helium ionization to spatial correlation or self-organization of granular flows have been proposed as physical mechanisms to explain solar supergranulation. However, its existence remains largely a mystery. Remarkably, horizontal velocity power spectra obtained from Doppler imaging and correlation tracking of flow features at the solar surface reveal the presence of peaks corresponding to granular and supergranular scales, followed by a monotonic decrease in power at scales larger than supergranulation, which suggests that large-scale modes in the deep layers of the convection zone may be suppressed. Using 3D anelastic simulations of solar convection we investigate whether supergranulation may reflect the largest buoyantly driven mode of convection inside the Sun. Results show that the amount of kinetic energy contained in the largest flow scales relative to that associated with supergranular motions is a function of the depth of the transition from a convectively unstable to convectively stable mean stratification inside the simulation. This suggests that the observed monotonic decrease in power at scales larger than supergranulation may be explained by rapid cooling in the subphotospheric layers and an essentially isentropic solar interior, wherein convective driving is effectively suppressed.

  10. A de-noising algorithm based on wavelet threshold-exponential adaptive window width-fitting for ground electrical source airborne transient electromagnetic signal

    NASA Astrophysics Data System (ADS)

    Ji, Yanju; Li, Dongsheng; Yu, Mingmei; Wang, Yuan; Wu, Qiong; Lin, Jun

    2016-05-01

    The ground electrical source airborne transient electromagnetic system (GREATEM) on an unmanned aircraft enjoys considerable prospecting depth, lateral resolution and detection efficiency, etc. In recent years it has become an important technical means of rapid resources exploration. However, GREATEM data are extremely vulnerable to stationary white noise and non-stationary electromagnetic noise (sferics noise, aircraft engine noise and other human electromagnetic noises). These noises will cause degradation of the imaging quality for data interpretation. Based on the characteristics of the GREATEM data and major noises, we propose a de-noising algorithm utilizing wavelet threshold method and exponential adaptive window width-fitting. Firstly, the white noise is filtered in the measured data using the wavelet threshold method. Then, the data are segmented using data window whose step length is even logarithmic intervals. The data polluted by electromagnetic noise are identified within each window based on the discriminating principle of energy detection, and the attenuation characteristics of the data slope are extracted. Eventually, an exponential fitting algorithm is adopted to fit the attenuation curve of each window, and the data polluted by non-stationary electromagnetic noise are replaced with their fitting results. Thus the non-stationary electromagnetic noise can be effectively removed. The proposed algorithm is verified by the synthetic and real GREATEM signals. The results show that in GREATEM signal, stationary white noise and non-stationary electromagnetic noise can be effectively filtered using the wavelet threshold-exponential adaptive window width-fitting algorithm, which enhances the imaging quality.

  11. Source apportionment of polycyclic aromatic hydrocarbons and their derivatives in indoor air

    SciTech Connect

    Ray, B.; Mitra, S.

    1996-12-31

    The average person spends more than 80% of his time indoors, thus analysis of the sources of airborne pollutants in indoor air is an important issue. In this paper, we use factor analysis and multiple regression to identify and apportion the different sources of select indoor polycyclic aromatic hydrocarbons (PAHs), their derivatives, and nicotine in indoor air, using data gathered in eight homes in Columbus, OH during the winter of 1986/1987. These homes had different indoor PAH sources, namely, environmental tobacco smoke, gas cooking/heating, and electrical cooking stoves. We find that, of all the sources, environmental tobacco smoke appears to have the greatest impact on the total indoor PAH concentrations. In smokers` homes, more than 87% of the total PAH is due to this source. Background sources are the largest contributor to PAHs in nonsmokers` homes. Very little PAH can be attributed to gas or electric appliances in the home. 16 refs., 3 tabs.

  12. Radioisotope Sources of Electric Power

    DTIC Science & Technology

    1973-09-20

    aiozoopye stc~i± 9p.D D C ’ SOUCE:Atomizdat, Moscow 1972, p. Mektricheekay gugerLl W AUTiIOR:qv* pe Fradkin and v .M. Kodyukov Z3, LANGUAGE : Russian...and Plectrical fieldq, chemical comoosition of the material, etc. The values of the half- lives may vary from fr.ctions of :i second to millions of...nucleus (first term), the ene:cLv of the T’ -niianta (tnird term), and the enemyV of the Oel -particles ( second term). W.nen there is soortaneous dec.Vy

  13. Auditory processing in schizophrenia during the middle latency period (10–50 ms): high-density electrical mapping and source analysis reveal subcortical antecedents to early cortical deficits

    PubMed Central

    Leavitt, Victoria M.; Molholm, Sophie; Ritter, Walter; Shpaner, Marina; Foxe, John J.

    2007-01-01

    Introduction Auditory sensory processing dysfunction is a core component of schizophrenia, with deficits occurring at 50 ms post-stimulus firmly established in the literature. Given that the initial afference of primary auditory cortex occurs at least 35 ms earlier, however, an essential question remains: how early in sensory processing do such deficits arise, and do they occur during initial cortical afference or earlier, which would implicate subcortical auditory dysfunction. Objective To establish the onset of the earliest deficits in auditory processing, we examined the time window demarcating the transition from subcortical to cortical processing: 10 ms to 50 ms during the so-called middle latency responses (MLRs). These remain to be adequately characterized in patients with schizophrenia. Methods We recorded auditory evoked potentials (AEPs) to simple tone-pips from 15 control subjects and 21 medicated patients with longer-term schizophrenia or schizoaffective disorder (illness duration 16 yr, standard deviation [SD] 9.4 yr), using high-density electrical scalp recordings. Between-group analyses assessed the integrity of the MLRs across groups. In addition, 2 source-localization models were conducted to address whether a distinction between subcortical and cortical generators of the MLRs can be made and whether evidence for differential dorsal and ventral pathway contributions to auditory processing deficits can be established. Results Robust auditory processing deficits were found for patients as early as 15 ms. Evidence for subcortical generators of the earliest MLR component (P20) was provided by source analysis. Topographical mapping and source localization also pointed to greater decrements in processing in the dorsal auditory pathway of patients, providing support for a theory of pervasive deficits that are organized along the lines of a dorsal–ventral distinction. Conclusions Auditory sensory dysfunction in schizophrenia begins extremely early in

  14. Largest Aftershocks of Megathrust Earthquakes in the World

    NASA Astrophysics Data System (ADS)

    Koyama, J.; Tsuzuki, M.

    2012-12-01

    The 2011 Tohoku-oki megathrust earthquake of Mw9.0 induced the earthquake activity in high level all over Japan. It included not only earthquakes near active faults but also volcanic earthquakes. Although we have observed tens of thousands of aftershocks, yet we do not know which is the largest aftershock of the 2011 megathrust. There occurred several megathrust earthquakes worldwide in the last one hundred years, which are almost the same size or larger than the 2011 megathrust. We have studied their largest aftershocks based on our new hypothesis of along-dip double segmentation (ADDS) and along-strike single segmentation (ASSS). ADDS in the Tohoku-oki region along the Japan trench is characterized by the apparent absence of earthquakes in the trench-ward segments as opposed to the Japan Island-ward segments that have repeated small earthquakes of up to Mw8 class. In contrast, the 1960 Chile and the 2010 Maule megathrusts are characterized by ASSS with the weak seismic activity before the main event everywhere in the subduction zone. The difference between these two types of seismic segmentations would be that strongly coupled areas of trench-ward segments give rise to ADDS, whereas almost 100% coupled areas of shallow-parts of subduction zones give rise to ASSS. In other words, the phenomenon of a seismic gap can be identified for an ASSS megathrust, where as a doughnut pattern of seismic activity appears prior to a main ADDS event. In summary, most of the largest aftershocks of ADDS megathrusts are earthquakes of outer-rise(outer trench-slope) normal faultings, where there occur two types, dip-slip and strike-slip, depending on the structure of subducting oceanic plates. The 1933 Sanriku-oki Mw8.6 (the 1896 Meiji-Sanriku M~8.5) and the 2011 Tohoku-oki Mw7.7 (the 2011 Tohoku-oki Mw9.0) are the former and the 1987 Off Alaska Mw7.8 (the 1964 Alaska Mw9.2) and the 2012 Sumatra Mw8.6 (the 2004 Sumatra-Andaman Mw9.3) are the latter. Those of ASSS megathrusts occurred

  15. Modelling Thermal Emission to Constrain Io's Largest Eruptions

    NASA Astrophysics Data System (ADS)

    Davies, A. G.; De Pater, I.; de Kleer, K.; Head, J. W., III; Wilson, L.

    2016-12-01

    Massive, voluminous, low-silica content basalt lava flows played a major role in shaping the surfaces of the terrestrial planets and the Moon [1] but the mechanisms of eruption, including effusion rate profiles and flow regime, are often obscure. However, eruptions of large volumes of lava and the emplacement of thick, areally extensive silicate lava flows are extant on the volcanic jovian moon Io [2], thus providing a template for understanding how these processes behaved elsewhere in the Solar System. We have modelled data of the largest of these eruptions to constrain eruption processes from the evolution of the wavelength variation of the resulting thermal emission [3]. We continue to refine our models to further constrain eruption parameters. We focus on large "outburst" eruptions, large lava fountains which feed lava flows [4] which have been directly observed on Io from the Galileo spacecraft [5, 6]. Outburst data continue to be collected by large ground-based telescopes [7, 8]. These data have been fitted with a sophisticated thermal emission model to derive eruption parameters such as areal coverage and effusion rates. We have created a number of tools for investigating and constraining effusion rate for Io's largest eruptions. It remains for all of the components to be integrated into a single model with rheological properties dependent on flow regime and the effects of heat loss. The crucial advance on previous estimates of lava flow emplacement on Io [e.g., 5] is that, by keeping track of the temperature distribution on the surface of the lava flows (a function of flow regime and varying effusion rate) the integrated thermal emission spectrum can be synthesized. This work was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under contract to NASA. We thank the NASA OPR Program (NNN13D466T) and NSF (Grant AST-1313485) for supports. Refs: [1] Wilson, L. and J. W. Head (2016), Icarus, doi:10.1016/j.icarus.2015.12.039. [2

  16. Spectral properties of the largest asteroids associated with Taurid Complex

    NASA Astrophysics Data System (ADS)

    Popescu, M.; Birlan, M.; Nedelcu, D. A.; Vaubaillon, J.; Cristescu, C. P.

    2014-12-01

    Context. The Taurid Complex is a massive stream of material in the inner part of the Solar System. It contains objects spanning the range of 10-6-103 m, considered by some authors to have a common cometary origin. The asteroids belonging to Taurid Complex are on Apollo type orbit, with most of them being flagged as potentially hazardous asteroids. In this context, understanding the nature and the origin of this asteroidal population is not only of scientific interest but also of practical importance. Aims: We aim to investigate the surface mineralogy of the asteroids associated with Taurid Complex using visible and near-infrared spectral data. Compositional linking between these asteroids and meteorites can be derived based on the obtained spectra. Methods: We obtained spectra of six of the largest asteroids (2201, 4183, 4486, 5143, 6063, and 269690) associated with Taurid complex. The observations were made with the IRTF telescope equipped with the spectro-imager SpeX. Their taxonomic classification is made using Bus-DeMeo taxonomy. The asteroid spectra are compared with the meteorite spectra from the Relab database. Mineralogical models were applied to determine their surface composition. All the spectral analysis is made in the context of the already published physical data. Results: Five of the objects studied in this paper present spectral characteristics similar to the S taxonomic complex. The spectra of ordinary chondrites (spanning H, L, and LL subtypes) are the best matches for these asteroid spectra. The asteroid (269690) 1996 RG3 presents a flat featureless spectrum which could be associated to a primitive C-type object. The increased reflectance above 2.1 microns constrains its geometrical albedo to a value around 0.03. Conclusions: While there is an important dynamical grouping among the Taurid Complex asteroids, the spectral data of the largest objects do not support a common cometary origin. Furthermore, there are significant variations between the

  17. Diverse Hispanic population to become largest U.S. minority.

    PubMed

    1997-11-01

    High immigration rates and relatively high birth rates have made Hispanics the second fastest growing minority population in the US. Only the Asian population is growing faster. In 1996, 11% of the US's population was Hispanic. However, Hispanic Americans are projected to outnumber African Americans by 2005, and by 2050, the Hispanic population in the US is projected to total approximately 100 million, 25% of the US population and the largest of the country's ethnic minorities. Latinos have the lowest rates of high school and college graduation of any major population group in the US. Since relevant data first became available in 1972 and until 1994, the median income of Latino families has remained below that of White families, but above that of African American families. The Hispanics' median family income of $24,000 in 1995 was below that of African American families. Puerto Rican and Mexican families are most likely to be poor, while Cubans are least likely. There is considerable diversity within the US's Hispanic population. For example, some Hispanics speak only Spanish, while others speak no Spanish at all. Hispanic Americans come from many countries and cultures, making the differences between and within the Hispanic ethnic groups sometimes as great as their similarities. Most Americans do not understand that Hispanics are an ethnic group, not a racial group.

  18. Huge-LQG- the largest structure in the universe

    NASA Astrophysics Data System (ADS)

    Clowes, R. G.; Raghunathan, S.; Harris, K. A.; Campusano, L. E.; Sochting, I. K.; Graham, M. J.

    2014-10-01

    A large quasar group (LQG) of particularly large size and high membership has been identified in the DR7QSO catalogue of the Sloan Digital Sky Survey. It has characteristic size (volume^{1/3}) ˜ 500 Mpc (proper size, present epoch), longest dimension ˜ 1240 Mpc, membership of 73 quasars and mean redshift z=1.27. In terms of both size and membership, it is the most extreme LQG found in the DR7QSO catalog for the redshift range 1.0 < z <1.8 of our current investigation. Its location on the sky is ˜ 8.8 degrees north (˜ 615 Mpc projected) of the Clowes & Campusano LQG at the same redshift, z=1.28, which is itself one of the more extreme examples. This new, Huge-LQG appears to be the largest structure currently known in the early Universe. Its size suggests incompatibility with the Yadav et al. (2010) scale of homogeneity for the concordance cosmology, and thus challenges the assumption of the cosmological principle.

  19. World's Largest Gold Crystal Studied at Los Alamos

    ScienceCinema

    Vogel, Sven; Nakotte, Heinz

    2016-07-12

    When geologist John Rakovan needed better tools to investigate whether a dazzling 217.78-gram piece of gold was in fact the world's largest single-crystal specimen - a distinguishing factor that would not only drastically increase its market value but also provide a unique research opportunity - he traveled to Los Alamos National Laboratory's Lujan Neutron Scattering Center to peer deep inside the mineral using neutron diffractometry. Neutrons, different from other probes such as X-rays and electrons, are able to penetrate many centimeters deep into most materials. Revealing the inner structure of a crystal without destroying the sample - imperative, as this one is worth an estimated $1.5 million - would allow Rakovan and Lujan Center collaborators Sven Vogel and Heinz Nakotte to prove that this exquisite nugget, which seemed almost too perfect and too big to be real, was a single crystal and hence a creation of nature. Its owner, who lives in the United States, provided the samples to Rakovan to assess the crystallinity of four specimens, all of which had been found decades ago in Venezuela.

  20. Developmental origins of the world’s largest flowers, Rafflesiaceae

    PubMed Central

    Nikolov, Lachezar A.; Endress, Peter K.; Sugumaran, M.; Sasirat, Sawitree; Vessabutr, Suyanee; Kramer, Elena M.; Davis, Charles C.

    2013-01-01

    Rafflesiaceae, which produce the world’s largest flowers, have captivated the attention of biologists for nearly two centuries. Despite their fame, however, the developmental nature of the floral organs in these giants has remained a mystery. Most members of the family have a large floral chamber defined by a diaphragm. The diaphragm encloses the reproductive organs where pollination by carrion flies occurs. In lieu of a functional genetic system to investigate floral development in these highly specialized holoparasites, we used comparative studies of structure, development, and gene-expression patterns to investigate the homology of their floral organs. Our results surprisingly demonstrate that the otherwise similar floral chambers in two Rafflesiaceae subclades, Rafflesia and Sapria, are constructed very differently. In Rafflesia, the diaphragm is derived from the petal whorl. In contrast, in Sapria it is derived from elaboration of a unique ring structure located between the perianth and the stamen whorl, which, although developed to varying degrees among the genera, appears to be a synapomorphy of the Rafflesiaceae. Thus, the characteristic features that define the floral chamber in these closely related genera are not homologous. These differences refute the prevailing hypothesis that similarities between Sapria and Rafflesia are ancestral in the family. Instead, our data indicate that Rafflesia-like and Sapria-like floral chambers represent two distinct derivations of this morphology. The developmental repatterning we identified in Rafflesia, in particular, may have provided architectural reinforcement, which permitted the explosive growth in floral diameter that has arisen secondarily within this subclade. PMID:24167265

  1. World's Largest Gold Crystal Studied at Los Alamos

    SciTech Connect

    Vogel, Sven; Nakotte, Heinz

    2014-04-03

    When geologist John Rakovan needed better tools to investigate whether a dazzling 217.78-gram piece of gold was in fact the world's largest single-crystal specimen - a distinguishing factor that would not only drastically increase its market value but also provide a unique research opportunity - he traveled to Los Alamos National Laboratory's Lujan Neutron Scattering Center to peer deep inside the mineral using neutron diffractometry. Neutrons, different from other probes such as X-rays and electrons, are able to penetrate many centimeters deep into most materials. Revealing the inner structure of a crystal without destroying the sample - imperative, as this one is worth an estimated $1.5 million - would allow Rakovan and Lujan Center collaborators Sven Vogel and Heinz Nakotte to prove that this exquisite nugget, which seemed almost too perfect and too big to be real, was a single crystal and hence a creation of nature. Its owner, who lives in the United States, provided the samples to Rakovan to assess the crystallinity of four specimens, all of which had been found decades ago in Venezuela.

  2. [A Standing Balance Evaluation Method Based on Largest Lyapunov Exponent].

    PubMed

    Liu, Kun; Wang, Hongrui; Xiao, Jinzhuang; Zhao, Qing

    2015-12-01

    In order to evaluate the ability of human standing balance scientifically, we in this study proposed a new evaluation method based on the chaos nonlinear analysis theory. In this method, a sinusoidal acceleration stimulus in forward/backward direction was forced under the subjects' feet, which was supplied by a motion platform. In addition, three acceleration sensors, which were fixed to the shoulder, hip and knee of each subject, were applied to capture the balance adjustment dynamic data. Through reconstructing the system phase space, we calculated the largest Lyapunov exponent (LLE) of the dynamic data of subjects' different segments, then used the sum of the squares of the difference between each LLE (SSDLLE) as the balance capabilities evaluation index. Finally, 20 subjects' indexes were calculated, and compared with evaluation results of existing methods. The results showed that the SSDLLE were more in line with the subjects' performance during the experiment, and it could measure the body's balance ability to some extent. Moreover, the results also illustrated that balance level was determined by the coordinate ability of various joints, and there might be more balance control strategy in the process of maintaining balance.

  3. Benchmark Testing of the Largest Titanium Aluminide Sheet Subelement Conducted

    NASA Technical Reports Server (NTRS)

    Bartolotta, Paul A.; Krause, David L.

    2000-01-01

    To evaluate wrought titanium aluminide (gamma TiAl) as a viable candidate material for the High-Speed Civil Transport (HSCT) exhaust nozzle, an international team led by the NASA Glenn Research Center at Lewis Field successfully fabricated and tested the largest gamma TiAl sheet structure ever manufactured. The gamma TiAl sheet structure, a 56-percent subscale divergent flap subelement, was fabricated for benchmark testing in three-point bending. Overall, the subelement was 84-cm (33-in.) long by 13-cm (5-in.) wide by 8-cm (3-in.) deep. Incorporated into the subelement were features that might be used in the fabrication of a full-scale divergent flap. These features include the use of: (1) gamma TiAl shear clips to join together sections of corrugations, (2) multiple gamma TiAl face sheets, (3) double hot-formed gamma TiAl corrugations, and (4) brazed joints. The structural integrity of the gamma TiAl sheet subelement was evaluated by conducting a room-temperature three-point static bend test.

  4. Characterization of the Largest Effector Gene Cluster of Ustilago maydis

    PubMed Central

    Vincon, Volker; Kahmann, Regine

    2014-01-01

    In the genome of the biotrophic plant pathogen Ustilago maydis, many of the genes coding for secreted protein effectors modulating virulence are arranged in gene clusters. The vast majority of these genes encode novel proteins whose expression is coupled to plant colonization. The largest of these gene clusters, cluster 19A, encodes 24 secreted effectors. Deletion of the entire cluster results in severe attenuation of virulence. Here we present the functional analysis of this genomic region. We show that a 19A deletion mutant behaves like an endophyte, i.e. is still able to colonize plants and complete the infection cycle. However, tumors, the most conspicuous symptoms of maize smut disease, are only rarely formed and fungal biomass in infected tissue is significantly reduced. The generation and analysis of strains carrying sub-deletions identified several genes significantly contributing to tumor formation after seedling infection. Another of the effectors could be linked specifically to anthocyanin induction in the infected tissue. As the individual contributions of these genes to tumor formation were small, we studied the response of maize plants to the whole cluster mutant as well as to several individual mutants by array analysis. This revealed distinct plant responses, demonstrating that the respective effectors have discrete plant targets. We propose that the analysis of plant responses to effector mutant strains that lack a strong virulence phenotype may be a general way to visualize differences in effector function. PMID:24992561

  5. Largest meteor since Tunguska event explodes above Russian city

    NASA Astrophysics Data System (ADS)

    Showstack, Randy

    2013-02-01

    The meteor that disintegrated in the atmosphere above Chelyabinsk, Russia, on 15 February, injuring more than 1000 people and causing widespread property damage from the shock wave, is the largest such incident since the 1908 Tunguska event in Siberia, according to Paul Chodas, research scientist in the Near-Earth Object (NEO) program office at NASA's Jet Propulsion Laboratory in Pasadena, Calif. During a 15 February teleconference, Chodas said it was an "incredible coincidence" that asteroid DA14 passed safely by Earth on the same day as the Chelyabinsk meteor; the 45-meter-wide asteroid sped by the planet at a distance of just 27,700 kilometers away on its closest approach. He stressed that the meteor was not related to DA14. The meteor "was coming from the wrong direction and at a completely different velocity," he said, noting that the orbit of the meteor went out to the asteroid belt while the orbit of DA14 "is very Earth-like, it does not go out so far."

  6. Elephants have relatively the largest cerebellum size of mammals.

    PubMed

    Maseko, Busisiwe C; Spocter, Muhammad A; Haagensen, Mark; Manger, Paul R

    2012-04-01

    The current study used MR imaging to determine the volume of the cerebellum and its component parts in the brain of three adult male African elephants (Loxodonta africana) and compared this with published data from Asian elephants and other mammalian species including odontocete cetaceans, primates, chiropterans, insectivores, carnivores, and artiodactyls. The cerebellum of the adult elephant has a volume of ∼925 mL (average of both African and Asian species). Allometric analysis indicates that the elephant has the largest relative cerebellum size of all mammals studied to date. In addition, both odontocete cetaceans and microchiropterans appear to have large relative cerebellar sizes. The vermal and hemispheric components of the African elephant cerebellum are both large relative to other mammals of similar brain size, however, for odontocete cetaceans the vermal component is small and the hemispheric component is large. These volumetric observations are related to life-histories and anatomies of the species investigated. The current study provides context for one aspect of the elephant brain in the broader picture of mammalian brain evolution.

  7. Characterization of the largest effector gene cluster of Ustilago maydis.

    PubMed

    Brefort, Thomas; Tanaka, Shigeyuki; Neidig, Nina; Doehlemann, Gunther; Vincon, Volker; Kahmann, Regine

    2014-07-01

    In the genome of the biotrophic plant pathogen Ustilago maydis, many of the genes coding for secreted protein effectors modulating virulence are arranged in gene clusters. The vast majority of these genes encode novel proteins whose expression is coupled to plant colonization. The largest of these gene clusters, cluster 19A, encodes 24 secreted effectors. Deletion of the entire cluster results in severe attenuation of virulence. Here we present the functional analysis of this genomic region. We show that a 19A deletion mutant behaves like an endophyte, i.e. is still able to colonize plants and complete the infection cycle. However, tumors, the most conspicuous symptoms of maize smut disease, are only rarely formed and fungal biomass in infected tissue is significantly reduced. The generation and analysis of strains carrying sub-deletions identified several genes significantly contributing to tumor formation after seedling infection. Another of the effectors could be linked specifically to anthocyanin induction in the infected tissue. As the individual contributions of these genes to tumor formation were small, we studied the response of maize plants to the whole cluster mutant as well as to several individual mutants by array analysis. This revealed distinct plant responses, demonstrating that the respective effectors have discrete plant targets. We propose that the analysis of plant responses to effector mutant strains that lack a strong virulence phenotype may be a general way to visualize differences in effector function.

  8. Largest known historical eruption in Africa: Dubbi volcano, Eritrea, 1861

    NASA Astrophysics Data System (ADS)

    Wiart, Pierre; Oppenheimer, Clive

    2000-04-01

    Dubbi volcano, located in the northeast part of the Afar triangle, erupted explosively in May 1861, showering maritime traffic in the Red Sea with pumice and plunging coastal settlements into darkness. Earthquakes associated with the opening phase of the eruption were felt in Yemen, and explosions were heard as far as Massawa, 330 km distant. More than 100 local inhabitants were reported killed, possibly as a result of pyroclastic flow emplacement. By October 1861, activity switched to basaltic fire-fountaining focused along a 4-km-long summit fissure that fed several lava flows that traveled as far as 22 km. We present a reconstruction of this unusual explosive and effusive eruption sequence based on interpretation of contemporary accounts, analysis of satellite imagery, field work, and laboratory geochemistry. The volume of lava flows alone, 3.5 km3, makes this the largest reported historical eruption in Africa. An anomalously cold Northern Hemisphere summer in 1862, recorded in tree-ring records, could be the result of Dubbi's sulfate aerosol veil.

  9. LHC World Largest Vacuum Systems Being Commissioned at CERN

    NASA Astrophysics Data System (ADS)

    Jimenez, Jose Miguel

    The CERN Large Hadron Collider (LHC) with its 26.7 km of circumference and three different vacuum systems for the beams and insulation vacuum for magnets and liquid helium transfer lines, will have the world's largest vacuum system operating over a wide range of pressures and employing an impressive array of vacuum technologies. This system is composed by 54 km of UHV vacuum for the circulating beams and 50 km of insulation vacuum. Over the 54 km of UHV beam vacuum, 48 km of this are at cryogenic temperature (1.9 K). The remaining 6 km of beam vacuum containing the insertions for “cleaning” the proton beams, radiofrequency cavities for accelerating the protons as well as beam-monitoring equipment is at ambient temperature and uses non-evaporable getter (NEG) coatings. The noble gases and methane is pumped out by 780 ion pumps. Pressure readings are provided by 170 Bayard-Alpert gauges and 1084 gauges (Pirani and cold cathode Penning). The cryogenic insulation vacuums while technically less demanding, impress by their size (50 km) and volume (15000 m3). Once roughed using mechanical pumps, the vacuum relies on the cryopumping which allows reaching pressure in the 10-4 Pa range.

  10. Holocene dynamics of the Arctic's largest ice shelf.

    PubMed

    Antoniades, Dermot; Francus, Pierre; Pienitz, Reinhard; St-Onge, Guillaume; Vincent, Warwick F

    2011-11-22

    Ice shelves in the Arctic lost more than 90% of their total surface area during the 20th century and are continuing to disintegrate rapidly. The significance of these changes, however, is obscured by the poorly constrained ontogeny of Arctic ice shelves. Here we use the sedimentary record behind the largest remaining ice shelf in the Arctic, the Ward Hunt Ice Shelf (Ellesmere Island, Canada), to establish a long-term context in which to evaluate recent ice-shelf deterioration. Multiproxy analysis of sediment cores revealed pronounced biological and geochemical changes in Disraeli Fiord in response to the formation of the Ward Hunt Ice Shelf and its fluctuations through time. Our results show that the ice shelf was absent during the early Holocene and formed 4,000 years ago in response to climate cooling. Paleoecological data then indicate that the Ward Hunt Ice Shelf remained stable for almost three millennia before a major fracturing event that occurred ∼1,400 years ago. After reformation ∼800 years ago, freshwater was a constant feature of Disraeli Fiord until the catastrophic drainage of its epishelf lake in the early 21st century.

  11. Annual trauma load of the world's largest indoor skiing center.

    PubMed

    Van Laarhoven, S N; Latten, G; de Loos, E; van Hemert, W; Vles, G F

    2017-04-01

    There is limited data on the trauma load caused by indoor skiing centers. Therefore, all patients treated at the accident and emergency department of our level I trauma center who sustained injuries at the world's largest indoor skiing center were analyzed during a 3-year period. Business intelligence was used to identify all patients who sustained injury at SnowWorld, Landgraaf, The Netherlands, and were seen at the accident and emergency department of the Zuyderland Medical Center from January 1, 2012 till December 31, 2014. Data were collected on patient characteristics, trauma mechanism, transportation, admission, diagnostics, injury and its severity, and treatment. Of the 732 patients seen, 305 had a fracture and 80 a dislocation. Most patients were male snowboarders and most injuries were sustained during winter. More than 2000 X-rays and 100 CT scans were required. Seventy-two patients were admitted and immediate surgery was performed in 21 patients. Ten patients had Injury Severity Scores of 10 or higher. Snowboarders differed significantly from skiers on several parameters, e.g., 1 in 4 snowboarders seen had sustained a distal radius fracture compared to 1 in 100 skiers. Acquiring more insight into the characteristics of this specific patient population could benefit clinical care and help clinicians identify and target preventive strategies. IV.

  12. The National Ignition Facility: The World's Largest Laser

    SciTech Connect

    Moses, E I

    2003-10-13

    The National Ignition Facility (NIF), currently under construction at the Lawrence Livermore National Laboratory, is a stadium-sized facility containing a 192-beam, 1.8-Megajoule, 500-Terawatt, ultraviolet laser system together with a 10-meter diameter target chamber with room for nearly 100 experimental diagnostics. When completed, NIF will be the world's largest and most energetic laser experimental system, providing an international center to study inertial confinement fusion and the physics of matter at extreme energy densities and pressures. NIF's 192 energetic laser beams will compress fusion targets to conditions required for thermonuclear burn, liberating more energy than required to initiate the fusion reactions. Other NIF experiments will allow the study of physical processes at temperatures approaching 10{sup 8} K and 10{sup 11} Bars, conditions that exist naturally only in the interior of stars, planets and in nuclear weapons. NIF has now completed the first phases of its laser commissioning program. The first four beams of NIF have generated 106 kilo-joules of infrared light, exceeding design requirements. Operation of single beams at the second harmonic (531 nm) and third harmonic (351 nm) at greater than 10 kilojoules have also exceeded the performance criteria. NIF's target experimental systems are being commissioned and experiments have begun. This paper provides a detailed look the NIF laser systems, laser and optical performance and results from recent laser commissioning shots, and plans for commissioning diagnostics for experiments on NIF.

  13. Holocene dynamics of the Arctic's largest ice shelf

    PubMed Central

    Antoniades, Dermot; Francus, Pierre; Pienitz, Reinhard; St-Onge, Guillaume; Vincent, Warwick F.

    2011-01-01

    Ice shelves in the Arctic lost more than 90% of their total surface area during the 20th century and are continuing to disintegrate rapidly. The significance of these changes, however, is obscured by the poorly constrained ontogeny of Arctic ice shelves. Here we use the sedimentary record behind the largest remaining ice shelf in the Arctic, the Ward Hunt Ice Shelf (Ellesmere Island, Canada), to establish a long-term context in which to evaluate recent ice-shelf deterioration. Multiproxy analysis of sediment cores revealed pronounced biological and geochemical changes in Disraeli Fiord in response to the formation of the Ward Hunt Ice Shelf and its fluctuations through time. Our results show that the ice shelf was absent during the early Holocene and formed 4,000 years ago in response to climate cooling. Paleoecological data then indicate that the Ward Hunt Ice Shelf remained stable for almost three millennia before a major fracturing event that occurred ∼1,400 years ago. After reformation ∼800 years ago, freshwater was a constant feature of Disraeli Fiord until the catastrophic drainage of its epishelf lake in the early 21st century. PMID:22025693

  14. Ultrahigh B doping ({<=}10{sup 22} cm{sup -3}) during Si(001) gas-source molecular-beam epitaxy: B incorporation, electrical activation, and hole transport

    SciTech Connect

    Glass, G.; Kim, H.; Desjardins, P.; Taylor, N.; Spila, T.; Lu, Q.; Greene, J. E.

    2000-03-15

    Si(001) layers doped with B concentrations C{sub B} between 1x10{sup 17} and 1.2x10{sup 22} cm{sup -3} (24 at %) were grown on Si(001)2x1 at temperatures T{sub s}=500-850 degree sign C by gas-source molecular-beam epitaxy from Si{sub 2}H{sub 6} and B{sub 2}H{sub 6}. C{sub B} increases linearly with the incident precursor flux ratio J{sub B{sub 2}}{sub H{sub 6}}/J{sub Si{sub 2}}{sub H{sub 6}} and B is incorporated into substitutional electrically active sites at concentrations up to C{sub B}{sup *}(T{sub s}) which, for T{sub s}=600 degree sign C, is 2.5x10{sup 20} cm{sup -3}. At higher B concentrations, C{sub B} increases faster than J{sub B{sub 2}}{sub H{sub 6}}/J{sub Si{sub 2}}{sub H{sub 6}} and there is a large and discontinuous decrease in the activated fraction of incorporated B. However, the total activated B concentration continues to increase and reaches a value of N{sub B}=1.3x10{sup 21} cm{sup -3} with C{sub B}=1.2x10{sup 22} cm{sup -3}. High-resolution x-ray diffraction (HR-XRD) and reciprocal space mapping measurements show that all films, irrespective of C{sub B} and T{sub s}, are fully strained. No B precipitates or misfit dislocations were detected by HR-XRD or transmission electron microscopy. The lattice constant in the film growth direction a{sub (perpendicular} {sub sign)} decreases linearly with increasing C{sub B} up to the limit of full electrical activation and continues to decrease, but nonlinearly, with C{sub B}>C{sub B}{sup *}. Room-temperature resistivity and conductivity mobility values are in good agreement with theoretical values for B concentrations up to C{sub B}=2.5x10{sup 20} and 2x10{sup 21} cm{sup -3}, respectively. All results can be explained on the basis of a model which accounts for strong B surface segregation to the second-layer with a saturation coverage {theta}{sub B,sat} of 0.5 ML (corresponding to C{sub B}=C{sub B}{sup *}). At higher C{sub B} (i.e., {theta}{sub B}>{theta}{sub B,sat}), B accumulates in the upper layer as

  15. Controlling NOx emission from industrial sources

    SciTech Connect

    Srivastava, R.K.; Nueffer, W.; Grano, D.; Khan, S.; Staudt, J.E.; Jozewicz, W.

    2005-07-01

    A number of regulatory actions focused on reducing NOx emissions from stationary combustion sources have been taken in the United States in the last decade. These actions include the Acid Rain NOx regulations, the Ozone Transport Commission's NOx Budget Program, and the NOx SIP Call rulemakings. In addition to these regulations, the recent Interstate Air Quality Rulemaking proposal and other bills in the Congress are focusing on additional reductions of NOx. Industrial combustion sources accounted for about 18016 of NOx emissions in the United States in 2000 and constituted the second largest emitting source category within stationary sources, only behind electric utility sources. Based on these data, reduction of NOx emissions from industrial combustion sources is an important consideration in efforts undertaken to address the environmental concerns associated with NOx. This paper discusses primary and secondary NOx control technologies applicable to various major categories of industrial sources. The sources considered in this paper include large boilers, furnaces and fired heaters, combustion turbines, large IC engines, and cement kilns. For each source category considered in this paper, primary NOx controls are discussed first, followed by a discussion of secondary NOx controls.

  16. Potential for increased use of anthracite by electric utilities: implications of the exemption from the EPA new source performance standards for power plants

    SciTech Connect

    Not Available

    1982-02-01

    The prospect for expanded utility use of anthracite by the year 2000 appears promising. It has been generally considered that anthracite can meet the ambient SO/sub 2/ standard of 1.2 lbs. SO/sub 2/ per million Btu without the use of scrubbers. In that event, the results of the engineering economic analysis show that an anthracite-based electric generating unit can be competitive with a comparable bituminous coal-fired unit. The logical competitive utility market area for anthracite is the Northeastern United States and the Middle Atlantic States because of the proximity of these areas to the anthracite region. Transport costs would be lower for anthracite (versus western Pennsylvania bituminous coal) to destinations in the areas of states immediately north, east and southeast of the eastern Pennsylvania anthracite region - upstate New York, New Jersey and Delaware, in particular. The analyses of the impact of the New Source Performance Standards (NSPS) exemption, and of future base load plant expansions, indicates that the potential additional utility use of anthracite over the next two decades is within a range of 1.5 to 15 million tons per year. One means of enhancing the competitive posture of anthracite versus bituminous, the analysis concludes, could be a more intense examination of anthracite resources to determine the best locations of large quantities of low sulfur recoverable reserves. Similarly, a more detailed investigation of a stockpile program would be warranted to determine its feasibility as a means of providing reserve potential, primarily during initial expansion, to allay supply reliability concerns.

  17. Cassini RADAR Observes Titan's Kraken Mare, The Largest Extraterrestrial Sea

    NASA Astrophysics Data System (ADS)

    Kirk, R. L.

    2013-12-01

    Synthetic aperture radar (SAR) imaging by Cassini's RADAR instrument beginning in 2006 revealed the presence of hundreds of hydrocarbon lakes and three large seas in Titan's north polar region [1,2]. Kraken Mare appeared to be the largest sea in IR images [3] but only the northern end was imaged by RADAR prior to 2012. High altitude SAR (HiSAR) observations on recent Titan flybys T84, T91, and T92 now provide complete coverage of Kraken and environs to ~50°N, at resolutions of 2-10 km. Backscatter statistics of the sea are 0.002 × 0.04, i.e., any return is substantially less than the noise and much less than typical dry land cross sections of 0.1-1.5. We conclude that Kraken is liquid filled to substantial depth over its entire extent. A surprising result is that the major seas all lie within a 1800 x 900 km 'box' (Fig.1). A third of the area inside this box (0.6 M km2) is sea, whereas the largest lake outside the box is only 0.005 M km2. Kraken's overall shape is complex (lobateness 4.4 vs 2.1 for Ligeia) but its 0.44 M km2 is divided by 20 to 160 km wide straits into 5 sub-basins that are elongated E-W across the box. Numerous straight shoreline segments parallel the edges of the box. Others parallel the 10°, 80°, and 170°W meridians, as do the rectangular drainage patterns mapped by [4]. These alignments suggest a key role for tectonics in creating the depressions occupied by the northern seas. Fensal and Aztlan (the 'lazy H' of dune-filled lows straddling the equator at longitudes 0°-70°W) form a similar pattern of elongated depressions connected by a narrow strait within a rectangular box. In contrast, Titan's small lakes are widely distributed. Multiple depressions with radar-dark floors have been identified near the south pole and hypothesized as former seabeds [5], but though similar in size to the northern seas, they are not aligned with one another or tightly clustered. Thus, the geography of the north and south poles will remain distinct even if

  18. Genome size analyses of Pucciniales reveal the largest fungal genomes.

    PubMed

    Tavares, Sílvia; Ramos, Ana Paula; Pires, Ana Sofia; Azinheira, Helena G; Caldeirinha, Patrícia; Link, Tobias; Abranches, Rita; Silva, Maria do Céu; Voegele, Ralf T; Loureiro, João; Talhinhas, Pedro

    2014-01-01

    Rust fungi (Basidiomycota, Pucciniales) are biotrophic plant pathogens which exhibit diverse complexities in their life cycles and host ranges. The completion of genome sequencing of a few rust fungi has revealed the occurrence of large genomes. Sequencing efforts for other rust fungi have been hampered by uncertainty concerning their genome sizes. Flow cytometry was recently applied to estimate the genome size of a few rust fungi, and confirmed the occurrence of large genomes in this order (averaging 225.3 Mbp, while the average for Basidiomycota was 49.9 Mbp and was 37.7 Mbp for all fungi). In this work, we have used an innovative and simple approach to simultaneously isolate nuclei from the rust and its host plant in order to estimate the genome size of 30 rust species by flow cytometry. Genome sizes varied over 10-fold, from 70 to 893 Mbp, with an average genome size value of 380.2 Mbp. Compared to the genome sizes of over 1800 fungi, Gymnosporangium confusum possesses the largest fungal genome ever reported (893.2 Mbp). Moreover, even the smallest rust genome determined in this study is larger than the vast majority of fungal genomes (94%). The average genome size of the Pucciniales is now of 305.5 Mbp, while the average Basidiomycota genome size has shifted to 70.4 Mbp and the average for all fungi reached 44.2 Mbp. Despite the fact that no correlation could be drawn between the genome sizes, the phylogenomics or the life cycle of rust fungi, it is interesting to note that rusts with Fabaceae hosts present genomes clearly larger than those with Poaceae hosts. Although this study comprises only a small fraction of the more than 7000 rust species described, it seems already evident that the Pucciniales represent a group where genome size expansion could be a common characteristic. This is in sharp contrast to sister taxa, placing this order in a relevant position in fungal genomics research.

  19. Flow mixing at the World's largest river confluence

    NASA Astrophysics Data System (ADS)

    Best, Jim; Ianniruberto, Marco; Gualtieri, Carlo; Paes de Almeida, Renato; Freitas, Bernardo; Nogueira, Pedro; Cisneros, Julia

    2017-04-01

    River confluences form key nodes within all fluvial networks and points of significant, and non-linear, changes in flow discharge, sediment grain size and bed morphology. It is generally acknowledged that the hydrodynamics and morphodynamics within the confluence zone are influenced by the junction planform, the momentum flux ratio between the merging streams, and the level of concordance between channel beds at the confluence entrance. Recent work has also identified the role of density differences between the confluent flows as potentially exerting a significant influence on fluid mixing. Perhaps the most well-known example, which has attracted considerable recent study, is at the world's largest river confluence - the Rio Solimões and Rio Negro (the Encontro das Águas), near Manaus, in the Amazonian basin. This paper sheds new light on the patterns of mixing at the Encontro das Águas as revealed by combined multibeam echo sounder (MBES) and acoustic Doppler current profiling (aDcp) surveys. The MBES survey reveals that the scour and bed morphology at this confluence, that can be up to c. 80m deep, is dominated by the presence of Cretaceous bedrock and that the mobile bedload sediment from the Rio Solimões is confined to a narrow zone of transport. The suspended sediment plume from the Rio Solimões interacts with the bedrock, which can comprise subaqueous roughness up to 20m in height, and is consequently diverted both laterally and vertically by this topography. The aDcp surveys reveal the nature of this topographic interaction and suggest that the routing of sediment-laden fluid within the junction, and the patterns of upwelling on the flow surface, are significantly influenced by these flow-bedrock interactions. Details of the topography and these fluid dynamic interactions will be presented, together with an analysis of satellite imagery that links the longevity of the location of some of the upwellings to the presence of bedrock roughness.

  20. Stratification at the Earth's largest hyperacidic lake and its consequences

    NASA Astrophysics Data System (ADS)

    Caudron, Corentin; Campion, Robin; Rouwet, Dmitri; Lecocq, Thomas; Capaccioni, Bruno; Syahbana, Devy; Suparjan; Purwanto, Bambang Heri; Bernard, Alain

    2017-02-01

    Volcanic lakes provide windows into the interior of volcanoes as they integrate the heat flux discharged by a magma body and condense volcanic gases. Volcanic lake temperatures and geochemical compositions therefore typically serve as warnings for resumed unrest or prior to eruptions. If acidic and hot, these lakes are usually considered to be too convective to allow any stratification within their waters. Kawah Ijen volcano, featuring the largest hyperacidic lake on Earth (volume of 27 million m3), is less homogeneous than previously thought. Hourly temperature measurements reveal the development of a stagnant layer of cold waters (<30 °C), overlying warmer and denser water (generally above 30 °C and density ∼1.083 kg/m3). Examination of 20 yrs of historical records and temporary measurements show a systematic thermal stratification during rainy seasons. The yearly rupture of stratification at the end of the rainy season causes a sudden release of dissolved gases below the cold water layer which appears to generate a lake overturn, i.e. limnic eruption, and a resonance of the lake, i.e. a seiche, highlighting a new hazard for these extreme reservoirs. A minor non-volcanic event, such as a heavy rainfall or an earthquake, may act as a trigger. The density driven overturn requires specific salinity-temperature conditions for the colder and less saline top water layer to sink into the hot saline water. Spectacular degassing occurs when the dissolved gases, progressively stored during the rainy season due to a weakened diffusion of carbon dioxide in the top layer, are suddenly released. These findings challenge the homogenization assumption at acidic lakes and stress the need to develop appropriate monitoring setups.

  1. High feeding costs limit dive time in the largest whales.

    PubMed

    Acevedo-Gutiérrez, A; Croll, D A; Tershy, B R

    2002-06-01

    Large body size usually extends dive duration in air-breathing vertebrates. However, the two largest predators on earth, the blue whale (Balaenoptera musculus) and the fin whale (B. physalus), perform short dives for their size. Here, we test the hypothesis that the foraging behavior of these two species (lunge-feeding) is energetically expensive and limits their dive duration. We estimated the cost of lunge-feeding in both species using an approach that combined attaching time/depth recorders to seven blue whales and eight fin whales and comparing the collected dive information with predictions made by optimality models of dive behavior. We show that the rate at which whales recovered from a foraging dive was twice that of a non-foraging dive and that the cost of foraging relative to the cost of travel to and from the prey patch was 3.15 in blue whales (95 % CI 2.58-3.72) and 3.60 in fin whales (95 % CI 2.35-4.85). Whales foraged in small areas (<1 km(2)) and foraging bouts lasted more than one dive, indicating that prey did not disperse and thus that prey dispersal could not account for the limited dive durations of the whales. Despite the enormous size of blue whales and fin whales, the high energetic costs of lunge-feeding confine them to short durations of submergence and to areas with dense prey aggregations. As a corollary, because of their limited foraging time under water, these whales may be particularly vulnerable to perturbations in prey abundance.

  2. Sequencing of tsunami waves: Why the first wave is not always the largest

    NASA Astrophysics Data System (ADS)

    Okal, Emile; Synolakis, Costas

    2015-04-01

    In many instances, the largest wave to hit a coastline during a tsunami is not the first one. Classical examples include the arrivals of the 1960 Chilean tsunami in Hilo, Hawaii, and of the 1964 Alaskan tsunami in Crescent City, California, where most casualties took place during later arrivals. This situation can be socially treacherous, since residents and civil defense authorities are led to believe that the worst is over after a first, relatively mild arrival, and to give an early "all clear" before the true largest wave, as was the case in Papeete, Tahiti during the 2011 Tohoku tsunami. We research this problem by using a number of simple models for which analytical solutions are available, as well as more realistic simulations of the large earthquake tsunamis of the past decade, and compare their results to a catalog of waveforms obtained at DART buoys spread over the Pacific Basin. Preliminary results indicate a transition from a regime of Maximum First Wave to one of Delayed Maximum when distance is increased, azimuth to receiver is moved away from the normal to fault strike, and/or source size is reduced.

  3. Genome size analyses of Pucciniales reveal the largest fungal genomes

    PubMed Central

    Tavares, Sílvia; Ramos, Ana Paula; Pires, Ana Sofia; Azinheira, Helena G.; Caldeirinha, Patrícia; Link, Tobias; Abranches, Rita; Silva, Maria do Céu; Voegele, Ralf T.; Loureiro, João; Talhinhas, Pedro

    2014-01-01

    Rust fungi (Basidiomycota, Pucciniales) are biotrophic plant pathogens which exhibit diverse complexities in their life cycles and host ranges. The completion of genome sequencing of a few rust fungi has revealed the occurrence of large genomes. Sequencing efforts for other rust fungi have been hampered by uncertainty concerning their genome sizes. Flow cytometry was recently applied to estimate the genome size of a few rust fungi, and confirmed the occurrence of large genomes in this order (averaging 225.3 Mbp, while the average for Basidiomycota was 49.9 Mbp and was 37.7 Mbp for all fungi). In this work, we have used an innovative and simple approach to simultaneously isolate nuclei from the rust and its host plant in order to estimate the genome size of 30 rust species by flow cytometry. Genome sizes varied over 10-fold, from 70 to 893 Mbp, with an average genome size value of 380.2 Mbp. Compared to the genome sizes of over 1800 fungi, Gymnosporangium confusum possesses the largest fungal genome ever reported (893.2 Mbp). Moreover, even the smallest rust genome determined in this study is larger than the vast majority of fungal genomes (94%). The average genome size of the Pucciniales is now of 305.5 Mbp, while the average Basidiomycota genome size has shifted to 70.4 Mbp and the average for all fungi reached 44.2 Mbp. Despite the fact that no correlation could be drawn between the genome sizes, the phylogenomics or the life cycle of rust fungi, it is interesting to note that rusts with Fabaceae hosts present genomes clearly larger than those with Poaceae hosts. Although this study comprises only a small fraction of the more than 7000 rust species described, it seems already evident that the Pucciniales represent a group where genome size expansion could be a common characteristic. This is in sharp contrast to sister taxa, placing this order in a relevant position in fungal genomics research. PMID:25206357

  4. GIS learning tool for world's largest earthquakes and their causes

    NASA Astrophysics Data System (ADS)

    Chatterjee, Moumita

    The objective of this thesis is to increase awareness about earthquakes among people, especially young students by showing the five largest and two most predictable earthquake locations in the world and their plate tectonic settings. This is a geographic based interactive tool which could be used for learning about the cause of great earthquakes in the past and the safest places on the earth in order to avoid direct effect of earthquakes. This approach provides an effective way of learning for the students as it is very user friendly and more aligned to the interests of the younger generation. In this tool the user can click on the various points located on the world map which will open a picture and link to the webpage for that point, showing detailed information of the earthquake history of that place including magnitude of quake, year of past quakes and the plate tectonic settings that made this place earthquake prone. Apart from knowing the earthquake related information students will also be able to customize the tool to suit their needs or interests. Students will be able to add/remove layers, measure distance between any two points on the map, select any place on the map and know more information for that place, create a layer from this set to do a detail analysis, run a query, change display settings, etc. At the end of this tool the user has to go through the earthquake safely guidelines in order to be safe during an earthquake. This tool uses Java as programming language and uses Map Objects Java Edition (MOJO) provided by ESRI. This tool is developed for educational purpose and hence its interface has been kept simple and easy to use so that students can gain maximum knowledge through it instead of having a hard time to install it. There are lots of details to explore which can help more about what a GIS based tool is capable of. Only thing needed to run this tool is latest JAVA edition installed in their machine. This approach makes study more fun and

  5. Development and bottlenecks of renewable electricity generation in China: a critical review.

    PubMed

    Hu, Yuanan; Cheng, Hefa

    2013-04-02

    This review provides an overview on the development and status of electricity generation from renewable energy sources, namely hydropower, wind power, solar power, biomass energy, and geothermal energy, and discusses the technology, policy, and finance bottlenecks limiting growth of the renewable energy industry in China. Renewable energy, dominated by hydropower, currently accounts for more than 25% of the total electricity generation capacity. China is the world's largest generator of both hydropower and wind power, and also the largest manufacturer and exporter of photovoltaic cells. Electricity production from solar and biomass energy is at the early stages of development in China, while geothermal power generation has received little attention recently. The spatial mismatch in renewable energy supply and electricity demand requires construction of long-distance transmission networks, while the intermittence of renewable energy poses significant technical problems for feeding the generated electricity into the power grid. Besides greater investment in research and technology development, effective policies and financial measures should also be developed and improved to better support the healthy and sustained growth of renewable electricity generation. Meanwhile, attention should be paid to the potential impacts on the local environment from renewable energy development, despite the wider benefits for climate change.

  6. Issues in International Energy Consumption Analysis: Electricity Usage in India’s Housing Sector

    EIA Publications

    2014-01-01

    India offers a unique set of features for studying electricity use in the context of a developing country. First, it has a rapidly developing economy with high yearly growth rates in gross domestic product (GDP). Second, it has the second -largest population in the world and is likely to have the largest population in the future. Third, its electric system is maturing—with known difficulties (outages, shortages, issues with reliability and quality) that are characteristic of a developing country. This article focuses on electricity use in the residential sector of India and discusses key trends and provides an overview of available usage estimates from various sources. Indian households are an interesting environment where many of India’s unique features interact. The recent economic gains correlate with rising incomes and possible changes in living standards, which could affect electricity or other energy use within households. Additionally, the maturing electric system and large population in India both offer opportunities to study a range of interactions between electrification and electricity usage in a developing country.

  7. Risk Factors and Prevalence of Helicobacter pylori in Five Largest Islands of Indonesia: A Preliminary Study

    PubMed Central

    Makmun, Dadang; Nusi, Iswan Abbas; Zain, Lukman Hakim; Zulkhairi; Akil, Fardah; Uswan, Willi Brodus; Simanjuntak, David; Uchida, Tomohisa; Adi, Pangestu; Utari, Amanda Pitarini; Rezkitha, Yudith Annisa Ayu; Subsomwong, Phawinee; Nasronudin; Suzuki, Rumiko; Yamaoka, Yoshio

    2015-01-01

    The prevalence of Helicobacter pylori infection in Indonesia is still controversial and mainly investigated in the largest ethnic group, Javanese. We examined the prevalence of H. pylori infection using four different tests including culture, histology confirmed by immunohistochemistry and rapid urease test. We also analyzed risk factors associated with H. pylori infection in five largest islands in Indonesia. From January 2014–February 2015 we consecutively recruited a total of 267 patients with dyspeptic symptoms in Java, Papua, Sulawesi, Borneo and Sumatera Island. Overall, the prevalence of H. pylori infection was 22.1% (59/267). Papuan, Batak and Buginese ethnics had higher risk for H. pylori infection than Javanese, Dayak and Chinese ethnics (OR = 30.57, 6.31, 4.95; OR = 28.39, 5.81, 4.61 and OR = 23.23, 4.76, 3.77, respectively, P <0.05). The sensitivity and specificity for RUT and culture were 90.2%, 92.9% and 80.5%, 98.2%, respectively. The patients aged 50–59 years group had significantly higher H. pylori infection than 30–39 years group (OR 2.98, P = 0.05). Protestant had significantly higher H. pylori infection rate than that among Catholic (OR 4.42, P = 0.008). It was also significantly lower among peoples who used tap water as source of drinking water than from Wells/river (OR 9.67, P = 0.03). However only ethnics as become independent risk factors for H. pylori infection. Although we confirmed low prevalence of H. pylori in Javanese; predominant ethnic in Indonesia, several ethnic groups had higher risk of H. pylori infection. The age, religion and water source may implicate as a risk factor for H. pylori infection in Indonesia. PMID:26599790

  8. Risk Factors and Prevalence of Helicobacter pylori in Five Largest Islands of Indonesia: A Preliminary Study.

    PubMed

    Syam, Ari Fahrial; Miftahussurur, Muhammad; Makmun, Dadang; Nusi, Iswan Abbas; Zain, Lukman Hakim; Zulkhairi; Akil, Fardah; Uswan, Willi Brodus; Simanjuntak, David; Uchida, Tomohisa; Adi, Pangestu; Utari, Amanda Pitarini; Rezkitha, Yudith Annisa Ayu; Subsomwong, Phawinee; Nasronudin; Suzuki, Rumiko; Yamaoka, Yoshio

    2015-01-01

    The prevalence of Helicobacter pylori infection in Indonesia is still controversial and mainly investigated in the largest ethnic group, Javanese. We examined the prevalence of H. pylori infection using four different tests including culture, histology confirmed by immunohistochemistry and rapid urease test. We also analyzed risk factors associated with H. pylori infection in five largest islands in Indonesia. From January 2014-February 2015 we consecutively recruited a total of 267 patients with dyspeptic symptoms in Java, Papua, Sulawesi, Borneo and Sumatera Island. Overall, the prevalence of H. pylori infection was 22.1% (59/267). Papuan, Batak and Buginese ethnics had higher risk for H. pylori infection than Javanese, Dayak and Chinese ethnics (OR = 30.57, 6.31, 4.95; OR = 28.39, 5.81, 4.61 and OR = 23.23, 4.76, 3.77, respectively, P <0.05). The sensitivity and specificity for RUT and culture were 90.2%, 92.9% and 80.5%, 98.2%, respectively. The patients aged 50-59 years group had significantly higher H. pylori infection than 30-39 years group (OR 2.98, P = 0.05). Protestant had significantly higher H. pylori infection rate than that among Catholic (OR 4.42, P = 0.008). It was also significantly lower among peoples who used tap water as source of drinking water than from Wells/river (OR 9.67, P = 0.03). However only ethnics as become independent risk factors for H. pylori infection. Although we confirmed low prevalence of H. pylori in Javanese; predominant ethnic in Indonesia, several ethnic groups had higher risk of H. pylori infection. The age, religion and water source may implicate as a risk factor for H. pylori infection in Indonesia.

  9. Positive fractional linear electrical circuits

    NASA Astrophysics Data System (ADS)

    Kaczorek, Tadeusz

    2013-10-01

    The positive fractional linear systems and electrical circuits are addressed. New classes of fractional asymptotically stable and unstable electrical circuits are introduced. The Caputo and Riemann-Liouville definitions of fractional derivatives are used to analysis of the positive electrical circuits composed of resistors, capacitors, coils and voltage (current) sources. The positive fractional electrical and specially unstable different types electrical circuits are analyzed. Some open problems are formulated.

  10. Normal modes from the 2013 Sea of Okhotsk earthquake, the largest deep event ever recorded

    NASA Astrophysics Data System (ADS)

    Okal, E. A.

    2013-12-01

    With a moment of 4.1 10**28 dyn*cm, the Sea of Okhotsk earthquake of 24 May 2013 is the largest deep event ever recorded. This provides a unique opportunity to study the excitation of low-frequency normal modes, including overtone and radial ones. The principal questions addressed will be the possible existence of a slow component to the source, which is not warranted by preliminary results; and the possible presence of an isotropic component to the moment tensor of its source. The latter was strongly debated in the case of the 1970 Colombian event (Gilbert and Dziewonski, 1973; Okal and Geller, 1979), and clearly found absent from the source of the 1994 Bolivian one (Kikuchi and Kanamori, 1994; Okal, 1996). Critical in this respect will be the investigation of the relative excitation of the the radial modes, and in particular, the fundamental 0s0, for which a sufficiently long (90 days) time series was not available by the submission deadline.

  11. Effect of energy source and xylanase addition on energy metabolism, performance, chemical body composition and total body electrical conductivity (TOBEC) of broilers.

    PubMed

    Dänicke, S; Halle, I; Strobel, E; Franke, E; Jeroch, H

    2001-10-01

    Three diets containing either no supplemented fat (LF), 12% soybean oil (SO) or 12% coconut oil (CO) were fed to broilers to examine energy utilization in two experiments. Heat production and energy retained as fat and protein were measured in the first experiment using a respiration technique in combination with C- and N-balance and controlled (pair-fed) feeding conditions. Growth performance, carcass composition, chemical body composition and total body electrical conductivity (TOBEC) were evaluated in a second experiment under ad libitum feeding conditions (from hatching to day 35). Moreover, each of the three diet types was tested with or without the addition of a xylanase-containing enzyme preparation in the growth experiment. Energy utilization (experiment 1), expressed as the ratio between total retained energy and metabolizable energy intake, amounted to 0.33, 0.36 and 0.39 in LF-, SO- and CO-fed groups, respectively. Applying ad libitum feeding conditions in the second experiment caused a significant reduction in feed intake and weight gain in broilers fed the CO-diet. The feed-to-gain ratio was significantly lower in birds given the fat-supplemented diets. The highest degree of fatness as indicated by the highest percentage of abdominal and visceral fat and by highest total fat content was found in birds fed the CO-diet. The higher the body protein content and the lower the body fat content, the higher the TOBEC value should be. This was confirmed when LF-fed broilers were compared to their CO-fed counterparts. However, fat type seemed to be related to TOBEC values since SO-fed broilers had similar TOBEC values as CO-fed birds, whereas chemical body composition was comparable to LF-fed broilers. Xylanase addition significantly increased weight gain up to 21 days of age and decreased the feed-to-gain ratio slightly, whereas none of the other parameters were influenced by this treatment. An interaction between energy source and enzyme supplementation was

  12. The Largest Holocene Eruption of the Central Andes Found

    NASA Astrophysics Data System (ADS)

    Fernandez-Turiel, J.; Rodriguez-Gonzalez, A.; Saavedra, J.; Perez-Torrado, F.; Carracedo, J.; Osterrieth, M.; Carrizo, J.; Esteban, G.

    2013-12-01

    We present new data and interpretation about a major eruption -spreading ˜110 km3 ashes over 440.000 km2- long thought to have occurred around 4200 years ago in the Cerro Blanco Volcanic Complex (CBVC) in NW Argentina. This eruption may be the biggest during the past five millennia in the Central Volcanic Zone of the Andes, and possibly one of the largest Holocene eruptions in the world. The environmental effects of this voluminous eruption are still noticeable, as evidenced by the high content of arsenic and other trace elements in the groundwaters of the Chacopampean Plain. The recognition of this significant volcanic event may shed new light on interpretations of critical changes observed in the mid-Holocene paleontological and archaeological records, and offers researchers an excellent, extensive regional chronostratigraphic marker for reconstructing mid-Holocene geological history over a wide geographical area of South America. More than 100 ashes were sampled in Argentina, Chile and Uruguay during different field campaigns. Ash samples were characterized by scanning electron microscope (SEM), X-ray diffraction (XRD), grain size distributions laser diffraction, and geochemically by electron microprobe (EMPA) and laser ablation-HR-ICP-MS. New and published 14C ages were calibrated to calendar years BP. The age of the most recent CBVC eruption is 4407-4093 cal y BP, indirectly dated by 14C of associated organic sediment within the lower part of a proximal fall deposit of this event (26°53'16.05"S-67°44'48.68"W). This is the youngest record of a major volcanic event in the Southern Puna. This age is consistent with other radiocarbon dates of organic matter in palaeosols underlying or overlying distal ash fall deposits. Based on their products, all of rhyolitic composition, we have distinguished 8 main episodes during the evolution of the most recent CBVC eruption: 1) the eruption began with a white rhyolite lava dome extrusion; 2) followed by a Plinian

  13. Smart-Geology for the World's largest fossil oyster reef

    NASA Astrophysics Data System (ADS)

    Dorninger, Peter; Nothegger, Clemens; Djuricic, Ana; Rasztovits, Sascha; Harzhauser, Mathias

    2014-05-01

    The geo-edutainment park "Fossilienwelt Weinviertel" at Stetten in Lower Austria exposes the world's largest fossil oyster biostrome. In the past decade, significant progress has been made in 3D digitizing sensor technology. To cope with the high amount of data, processing methods have been automated to a high degree. Consequently, we formulated the hypothesis that appropriate application of state-of-the-art 3D digitizing, data processing, and visualization technologies allows for a significant automation in paleontological prospection, making an evaluation of huge areas commercially feasible in both time and costs. We call the necessary processing steps "Smart Geology", being characterized by automation and large volumes of data. The Smart Geology project (FWF P 25883-N29) investigates three topics, 3D digitizing, automated geological and paleontological analysis and interpretation and finally investigating the applicability of smart devices for on-site accessibility of project data in order to support the two scientific hypotheses concerning the emerging process of the shell bed, i.e. was it formed by a tsunami or a major storm, and does it preserve pre- and post-event features. This contribution concentrates on the innovative and sophisticated 3D documentation and visualization processes being applied to virtualise approximately 15.000 fossil oysters at the approximately 25 by 17 m accessible shell bad. We decided to use a Terrestrial Laserscanner (TLS) for the determination of the geometrical 3D structures. The TLS achieves about 2 mm single point measurement accuracy. The scanning campaign provides a "raw" point cloud of approximately 1 bio. points at the respective area. Due to the scanning configuration used, the occurrence of occluded ares is minimized hence the full 3D structure of this unique site can be modelled. In addition, approximately 300 photos were taken with a nominal resolution of 0.6 mm per pixel. Sophisticated artificial lightning (close to

  14. ALMA Partners Break Ground on World's Largest Millimeter Wavelength Telescope

    NASA Astrophysics Data System (ADS)

    2003-11-01

    Scientists and dignitaries from North America, Europe, and Chile broke ground today (Thursday, November 6, 2003) on what will be the world's largest, most sensitive radio telescope operating at millimeter wavelengths. ALMA - the Atacama Large Millimeter Array - will be a single instrument composed of 64 high-precision antennas located on the Chajnantor plain of the Chilean Andes in the District of San Pedro de Atacama, 16,500 feet (5,000 meters) above sea level. ALMA's primary function will be to observe and image with unprecedented clarity the enigmatic cold regions of the Universe, which are optically dark, yet shine brightly in the millimeter portion of the electromagnetic spectrum. ALMA Array Artist's Conception of ALMA Array in Compact Configuration (Click on Image for Larger Version) Other Images Available: Artist's conception of the antennas for the Atacama Large Millimeter Array Moonrise over ALMA test equipment near Cerro Chajnantor, Chile VertexRSI antenna at the VLA test site The Atacama Large Millimeter Array is an international astronomy facility. ALMA is an equal partnership between Europe and North America, in cooperation with the Republic of Chile, and is funded in North America by the U.S. National Science Foundation (NSF) in cooperation with the National Research Council of Canada (NRC), and in Europe by the European Southern Observatory (ESO) and Spain. ALMA construction and operations are led on behalf of North America by the National Radio Astronomy Observatory (NRAO), which is managed by Associated Universities, Inc. (AUI), and on behalf of Europe by ESO. "The U.S. National Science Foundation joins today with our North American partner, Canada, and with the European Southern Observatory, Spain, and Chile to prepare for a spectacular new instrument," said Dr. Rita Colwell, director of the U.S. National Science Foundation. "The Atacama Large Millimeter Array will expand our vision of the Universe with "eyes" that pierce the shrouded mantles of

  15. 46 CFR 183.310 - Power sources.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...) ELECTRICAL INSTALLATION Power Sources and Distribution Systems § 183.310 Power sources. (a)(1) Each vessel... engine is used as a source of electrical power, a vessel speed change, throttle movement or change...

  16. Electrical Work in Schools.

    ERIC Educational Resources Information Center

    Ontario Dept. of Education, Toronto. School Business and Finance Branch.

    Most buildings rely on electricity for lighting, power, signals, and other communications. Electric energy is also used for heating and year-round thermal conditioning of spaces. Its ease of transmission, simple control and measurement, and relative safety make it a useful source of energy. This publication is intended to provide those persons…

  17. The network of Subterranean Electric Observations: Exploiting Crowd-Sourced Low-Cost Multielectrode System Improving Views of Tectonic Hazards on a Global Scale

    NASA Astrophysics Data System (ADS)

    Bobrovskiy, V.

    2015-12-01

    The key challenge of B.Gutenberg's question "What is the connection between solar activity, cyclones and earthquakes?" is the developing and testing our understanding with proper instrumentation that obtains data characterizing the nonstationary process production. Our ability to validate such connections through nonstationary subterranean electric processes is limited with a technique developing from the end of 19 century. A couple of measuring lines, extended along magnetic meridian and parallel, are used to detect worldwide component of electrotelluric field and to recognize non-stationary processes occurring prior to earthquakes in seismic-hazardous areas. Rather poor attempts have been driven us to investigate results of subterranean electric measurements at the division of atmosphere and tectonosphere. In this talk, we discuss the network of low cost multielectrode systems (operated by Distant School Cosmic-Meteo-Tectonics cosmetecor.org). Active electrical signals in the surface soils have proton nature and provide a unique view into electric networks of currents (circuits) with non-stationary processes production. Exploiting the subterranean electric measurement technique specifically designed to be locally sensitive we had begun to measure the individual characteristics of non-stationary subterranean electric processes those preceded the greatest earthquakes with M≥7 on a global scale. We present and describe the rapid installations of dense sensor network, its operation, data processing and distribution.

  18. Economics of electricity

    NASA Astrophysics Data System (ADS)

    Erdmann, G.

    2015-08-01

    The following text is an introduction into the economic theory of electricity supply and demand. The basic approach of economics has to reflect the physical peculiarities of electric power that is based on the directed movement of electrons from the minus pole to the plus pole of a voltage source. The regular grid supply of electricity is characterized by a largely constant frequency and voltage. Thus, from a physical point of view electricity is a homogeneous product. But from an economic point of view, electricity is not homogeneous. Wholesale electricity prices show significant fluctuations over time and between regions, because this product is not storable (in relevant quantities) and there may be bottlenecks in the transmission and distribution grids. The associated non-homogeneity is the starting point of the economic analysis of electricity markets.

  19. Ownership, financing, and management strategies of the ten largest for-profit nursing home chains in the United States.

    PubMed

    Harrington, Charlene; Hauser, Clarilee; Olney, Brian; Rosenau, Pauline Vaillancourt

    2011-01-01

    This study examined the ownership, financing, and management strategies of the 10 largest for-profit nursing home chains in the United States, including the four largest chains purchased by private equity corporations. Descriptive data were collected from Internet searches, company reports, and other sources for the decade 1998-2008. Since 1998, the largest chains have made many changes in their ownership and structure, and some have converted from publicly traded companies to private ownership. This study shows the increasing complexity of corporate nursing home ownership and the lack of public information about ownership and financial status. The chains have used strategies to maximize shareholder and investor value that include increasing Medicare revenues, occupancy rates, and company diversification, establishing multiple layers of corporate ownership, developing real estate investment trusts, and creating limited liability companies. These strategies enhance shareholder and investor profits, reduce corporate taxes, and reduce liability risk. There is a need for greater transparency in ownership and financial reporting and for more government oversight of the largest for-profit chains, including those owned by private equity companies.

  20. Cassini RADAR Observations of Saturn's Largest Moon, Titan

    NASA Astrophysics Data System (ADS)

    Hayes, A. G., Jr.; Mastrogiuseppe, M.; Lunine, J. I.; Lorenz, R. D.; Wall, S. D.; Stiles, B. W.; Kirk, R. L.; Elachi, C.; Hofgartner, J. D.; Birch, S. P.; Le Gall, A. A.; Poggiali, V.; Zebker, H. A.

    2015-12-01

    The Cassini RADAR is a versatile instrument capable of operating in imaging, altimetry, scatterometry, radiometry, and, most recently, sounding modes. Despite vastly different material properties and environmental conditions, Titan's methane-based hydrologic system drives climatic and geologic processes that result in morphologic features with striking similarity to terrestrial counterparts, including vast equatorial dune fields, well-organized channel networks that route material through erosional and depositional landscapes defining source-to-sink sediment transport systems, and, perhaps most astonishingly, lakes and seas filled with liquid hydrocarbons. Using its various operating modes, the Cassini RADAR has provided a wealth of information regarding Titan's active surface-atmosphere system. In Synthetic Aperture Radar (SAR) mode, the RADAR has unveiled Titan's surface by producing backscatter maps with pixel scales of ~300 m. In altimetry mode, the RADAR has shown the elevation profile of surface features, including the liquid elevation of Titan's lakes and seas, revealed the roughness characteristics of the surface, and constrained the global shape. Most recently, the altimetry mode has doubled as a radar sounder that has successfully probed the depth and absorptivity of the lakes and seas. Data from the scatterometry and radiometry modes have been used to constrain material properties, including dielectric constants and volume scattering fractions, surface texture, and derive seasonal and diurnal temperature variations. Collectively, these datasets have revealed Titan's strange yet familiar nature, and demonstrated that it is one of the most compelling targets in our solar system. During our presentation, we will summarize these capabilities and review some of the most specular discoveries made by the Cassini RADAR.