Science.gov

Sample records for denommee reacteur source

  1. Modelisation de la synthese reactive de poudres ultrafines dans un reacteur a plasma thermique

    NASA Astrophysics Data System (ADS)

    Desilets, Martin

    La presente these s'inscrit dans le cadre de la modelisation mathematique des ecoulements a plasmas thermiques inertes et reactifs. Elle vise plus precisement a combler les lacunes des modeles existants en portant une attention particuliere aux phenomenes de transport multicomposant et a la prediction des transformations chimiques. Pour repondre a ces attentes et ainsi poursuivre le developpement dans ce domaine, un modele global a ete developpe. Il combine la resolution d'equations conservatives pour la masse, l'energie et le momentum. La generation d'un plasma inductif (h.f ) y est traitee au moyen d'equations representant les champs electromagnetiques. La nucleation et la croissance de poudres ultrafines sont incluses dans le modele via l'analyse des principaux moments de la distribution des tailles de particules. Enfin, tous les phenomenes physico-chimiques d'importance dans un milieu comme les plasmas thermiques, de meme que lem interactions, sont consideres. Le modele est applique ici a l'analyse de trois problematiques differentes et complementaires. La premiere concerne l'etude du melange gazeux d'un jet froid (He, N 2 ou O2), injecte au coeur d'une decharge d'argon/hydrogene ou d'argon/oxygene. La comparaison des predictions du modele avec des mesures experimentales obtenues par une sonde enthalpique permet une validation partielle de ce dernier. La deuxieme problematique a trait a l'etude numerique de la pyrolyse du methane en reacteur a plasma h.f. Elle met en evidence les difficultes de convergence de la methode numerique lorsque appliquee a la resolution d'ecoulements reactifs a haute temperature. Finalement, le dernier sujet aborde dans cette these, soit l'analyse systematique des principales conditions d'operation d'un reacteur h.f utilise pour la synthese reactive de poudres ultrafines de silicium, engage tous les elements theoriques du modele. Il implique en effet la decomposition thermique d'un precurseur gazeux, le tetrachlorure de silicium, la

  2. Mise au point d'un reacteur epitaxial CBE

    NASA Astrophysics Data System (ADS)

    Pelletier, Hubert

    Ce projet de maîtrise consiste à l'asservissement et la mise en marche d'un réacteur d'épi-taxie par jets chimiques au Laboratoire d'Épitaxie Avancée de l'Université de Sherbrooke. Le réacteur sert à la croissance dans l'ultravide de matériaux semi-conducteurs tels que l'arséniure de gallium (GaAs) et le phosphure d'indium-gallium (GaInP). La programmation LabVIEW et du matériel informatique de National Instruments sont utilisés pour asservir le réacteur. Le contrôle de la température de l'échantillon et de la pression de contrôle des réactifs de croissance dans le réacteur est assuré par des boucles de rétroaction. Ainsi, la température de l'échantillon est stabilisée à ±0, 4 °C, alors que les pressions de contrôle de gaz peuvent être modulées sur un ordre de grandeur en 2 à 4 secondes, et stabilisées à ±0, 002 Torr. Le système de pompage du réacteur a été amélioré suite à des mesures de vitesse de pompage d'une pompe cryogénique. Ces mesures révèlent une dégradation sur plus d'un ordre de grandeur de son pompage d'hydrogène avec l'opération à long terme. Le remplacement de la pompe cryogénique par une pompe turbo-moléculaire comme pompe principale a permis d'améliorer la fiabilité du système de pompage du système sous vide. D'autre part, la conductance du système d'acheminement de gaz et d'injection a été augmentée afin de réduire un effet mémoire des sources le système et faciliter la croissance de matériaux ternaires. Ainsi, des croissances de GaAs (100) sur substrat de même nature ont été effectuées et ont révélé un matériau de bonne qualité. Sa rugosité moyenne de 0,17 nm, mesurée par microscopie à force atomique, est très faible selon la littérature. De plus, une mobilité élevée des porteurs est obtenue à fort dopage au silicium, au tellure et au carbone, notamment une mobilité de 42 ± 9 cm2V -1s-1 des porteurs majoritaires '(trous) lors du dopage au

  3. Nonpoint Sources.

    ERIC Educational Resources Information Center

    Browne, F. X.

    1978-01-01

    Presented a literature review of nonpoint source effects on water quality and pollution covering: (1) water quality effects; (2) watershed studies; (3) nonpoint source models; and nonpoint source controls. A list of 122 references published in 1976 and 1977 is also presented. (HM)

  4. Ion source

    DOEpatents

    Leung, Ka-Ngo; Ehlers, Kenneth W.

    1984-01-01

    A magnetic filter for an ion source reduces the production of undesired ion species and improves the ion beam quality. High-energy ionizing electrons are confined by the magnetic filter to an ion source region, where the high-energy electrons ionize gas molecules. One embodiment of the magnetic filter uses permanent magnets oriented to establish a magnetic field transverse to the direction of travel of ions from the ion source region to the ion extraction region. In another embodiment, low energy 16 eV electrons are injected into the ion source to dissociate gas molecules and undesired ion species into desired ion species.

  5. ION SOURCE

    DOEpatents

    Martina, E.F.

    1958-04-22

    An improved ion source particularly adapted to provide an intense beam of ions with minimum neutral molecule egress from the source is described. The ion source structure includes means for establishing an oscillating electron discharge, including an apertured cathode at one end of the discharge. The egress of ions from the source is in a pencil like beam. This desirable form of withdrawal of the ions from the plasma created by the discharge is achieved by shaping the field at the aperture of the cathode. A tubular insulator is extended into the plasma from the aperture and in cooperation with the electric fields at the cathode end of the discharge focuses the ions from the source,

  6. Light Source

    NASA Technical Reports Server (NTRS)

    1993-01-01

    Research on food growth for long duration spacecraft has resulted in a light source for growing plants indoors known as Qbeam, a solid state light source consisting of a control unit and lamp. The light source, manufactured by Quantum Devices, Inc., is not very hot, although it generates high intensity radiation. When Ron Ignatius, an industrial partner of WCSAR, realized that terrestrial plant research lighting was not energy efficient enough for space use, he and WCSAR began to experiment with light emitting diodes. A line of LED products was developed, and QDI was formed to market the technology. An LED-based cancer treatment device is currently under development.

  7. NEUTRON SOURCES

    DOEpatents

    Richmond, J.L.; Wells, C.E.

    1963-01-15

    A neutron source is obtained without employing any separate beryllia receptacle, as was formerly required. The new method is safer and faster, and affords a source with both improved yield and symmetry of neutron emission. A Be container is used to hold and react with Pu. This container has a thin isolating layer that does not obstruct the desired Pu--Be reaction and obviates procedures previously employed to disassemble and remove a beryllia receptacle. (AEC)

  8. Crowd Sourcing.

    PubMed

    Baum, Neil

    2016-01-01

    The Internet has contributed new words and slang to our daily vernacular. A few terms, such as tweeting, texting, sexting, blogging, and googling, have become common in most vocabularies and in many languages, and are now included in the dictionary. A new buzzword making the rounds in industry is crowd sourcing, which involves outsourcing an activity, task, or problem by sending it to people or groups outside a business or a practice. Crowd sourcing allows doctors and practices to tap the wisdom of many instead of relying only on the few members of their close-knit group. This article defines "crowd sourcing," offers examples, and explains how to get started with this approach that can increase your ability to finish a task or solve problems that you don't have the time or expertise to accomplish.

  9. ION SOURCE

    DOEpatents

    Leland, W.T.

    1960-01-01

    The ion source described essentially eliminater the problem of deposits of nonconducting materials forming on parts of the ion source by certain corrosive gases. This problem is met by removing both filament and trap from the ion chamber, spacing them apart and outside the chamber end walls, placing a focusing cylinder about the filament tip to form a thin collimated electron stream, aligning the cylinder, slits in the walls, and trap so that the electron stream does not bombard any part in the source, and heating the trap, which is bombarded by electrons, to a temperature hotter than that in the ion chamber, so that the tendency to build up a deposit caused by electron bombardment is offset by the extra heating supplied only to the trap.

  10. Neutron source

    DOEpatents

    Cason, J.L. Jr.; Shaw, C.B.

    1975-10-21

    A neutron source which is particularly useful for neutron radiography consists of a vessel containing a moderating media of relatively low moderating ratio, a flux trap including a moderating media of relatively high moderating ratio at the center of the vessel, a shell of depleted uranium dioxide surrounding the moderating media of relatively high moderating ratio, a plurality of guide tubes each containing a movable source of neutrons surrounding the flux trap, a neutron shield surrounding one part of each guide tube, and at least one collimator extending from the flux trap to the exterior of the neutron source. The shell of depleted uranium dioxide has a window provided with depleted uranium dioxide shutters for each collimator. Reflectors are provided above and below the flux trap and on the guide tubes away from the flux trap.

  11. RADIATION SOURCES

    DOEpatents

    Brucer, M.H.

    1958-04-15

    A novel long-lived source of gamma radiation especially suitable for calibration purposes is described. The source of gamma radiation is denoted mock iodine131, which comprises a naixture of barium-133 and cesium-137. The barium and cesium are present in a barium-cesium ratio of approximately 5.7/1 to 14/1, uniformly dispersed in an ion exchange resin and a filter surrounding the resin comprised of a material of atomic number below approximately 51, and substantially 0.7 to 0.9 millimeter thick.

  12. NEUTRON SOURCE

    DOEpatents

    Reardon, W.A.; Lennox, D.H.; Nobles, R.G.

    1959-01-13

    A neutron source of the antimony--beryllium type is presented. The source is comprised of a solid mass of beryllium having a cylindrical recess extending therein and a cylinder containing antimony-124 slidably disposed within the cylindrical recess. The antimony cylinder is encased in aluminum. A berylliunn plug is removably inserted in the open end of the cylindrical recess to completely enclose the antimony cylinder in bsryllium. The plug and antimony cylinder are each provided with a stud on their upper ends to facilitate handling remotely.

  13. Superluminal Sources

    NASA Astrophysics Data System (ADS)

    Vermeulen, R. C.

    1995-12-01

    Predictions for the apparent velocity statistics under simple beaming models are presented and compared to the observations. The potential applications for tests of unification models and for cosmology (source counts, measurements of the Hubble constant H_0 and the deceleration parameter q_0) are discussed. First results from a large homogeneous survey are presented. The data do not show compelling evidence for the existence of intrinsically different populations of galaxies, BL Lacertae objects, or quasars. Apparent velocities βapp in the range 1-5 h-1, where h = H_0/100 km.s-1.Mpc-1 [1 megaparsec (Mpc) = 3.09 x 1022 m], occur with roughly equal frequency; higher values, up to βapp = 10 h-1, are rather more scarce than appeared to be the case from earlier work, which evidently concentrated on sources that are not representative of the general population. The βapp distribution suggests that there might be a skewed distribution of Lorentz factors over the sample, with a peak at γ_b ≈ 2 h-1 and a tail up to at least γ_b ≈ 10 h-1. There appears to be a clearly rising upper envelope to the βapp distribution when plotted as a function of observed 5-GHz luminosity; a combination of source counts and the apparent velocity statistics in a larger sample could provide much insight into the properties of radio jet sources.

  14. Terahertz sources.

    PubMed

    Shumyatsky, Pavel; Alfano, Robert R

    2011-03-01

    We present an overview and history of terahertz (THz) sources for readers of the biomedical and optical community for applications in physics, biology, chemistry, medicine, imaging, and spectroscopy. THz low-frequency vibrational modes are involved in many biological, chemical, and solid state physical processes.

  15. ION SOURCE

    DOEpatents

    Brobeck, W.M.

    1959-04-14

    This patent deals with calutrons and more particularly to an arrangement therein whereby charged bottles in a calutron source unit may be replaced without admitting atmospheric air to the calutron vacuum chamber. As described, an ion unit is disposed within a vacuum tank and has a reservoir open toward a wall of the tank. A spike projects from thc source into the reservoir. When a charge bottle is placed in the reservoir, the spike breaks a frangible seal on the bottle. After the contents of the bottle are expended the bottle may be withdrawn and replaced with another charge bottle by a varuum lock arrangement in conjunction with an arm for manipulating the bottle.

  16. Ion source

    DOEpatents

    Brobeck, W. M.

    1959-04-14

    This patent deals with calutrons and more particularly to an arrangement therein whereby charged bottles in a calutron source unit may be replaced without admitting atmospheric air to the calutron vacuum chamber. As described, an ion unit is disposed within a vacuum tank and has a reservoir open toward a wall of the tank. A spike projects from the source into the reservoir. When a charge bottle is placed in the reservoir, the spike breaks a frangible seal on the bottle. After the contents of the bottle are expended the bottle may be withdrawn and replaced with another charge bottle by a vacuum lock arrangement in conjunction with an arm for manipulating the bottle.

  17. ION SOURCE

    DOEpatents

    Blue, C.W.; Luce, J.S.

    1960-07-19

    An ion source is described and comprises an arc discharge parallel to the direction of and inside of a magnetic field. an accelerating electrode surrounding substantially all of the discharge except for ion exit apertures, and means for establishing an electric field between that electrode and the arc discharge. the electric field being oriented at an acute angle to the magnetic field. Ions are drawn through the exit apertures in the accelrating electrcde in a direction substantially divergent to the direction of the magnetic field and so will travel in a spiral orbit along the magnetic field such that the ions will not strike the source at any point in their orbit within the magnetic field.

  18. ION SOURCE

    DOEpatents

    Bell, W.A. Jr.; Love, L.O.; Prater, W.K.

    1958-01-28

    An ion source is presented capable of producing ions of elements which vaporize only at exceedingly high temperatures, i.e.,--1500 degrees to 3000 deg C. The ion source utilizes beams of electrons focused into a first chamber housing the material to be ionized to heat the material and thereby cause it to vaporize. An adjacent second chamber receives the vaporized material through an interconnecting passage, and ionization of the vaporized material occurs in this chamber. The ionization action is produced by an arc discharge sustained between a second clectron emitting filament and the walls of the chamber which are at different potentials. The resultant ionized material egresses from a passageway in the second chamber. Using this device, materials which in the past could not be processed in mass spectometers may be satisfactorily ionized for such applications.

  19. RADIATION SOURCE

    DOEpatents

    Gow, J.D.

    1961-06-27

    An improved version of a crossed electric and magnetic field plasma producing and containing device of the general character disclosed in U. S. Patent No. 2,967,943 is described. This device employs an annular magnet encased within an anode and a pair of cathodes respectively coaxially spaced from the opposite ends of the anode to establish crossed field electron trapping regions adjacent the ends of the anode. The trapping regions are communicably connected through the throat of the anode and the electric field negatively increases in opposite axial directions from the center of the throat. Electrons are trapped within the two trapping regions and throat to serve as a source of intense ionization to gas introduced thereto, the ions in copious quantities being attracted to the cathodes to bombard neutron productive targets dlsposed - thereat.

  20. Radiation source

    DOEpatents

    Thode, Lester E.

    1981-01-01

    A device and method for relativistic electron beam heating of a high-density plasma in a small localized region. A relativistic electron beam generator or accelerator produces a high-voltage electron beam which propagates along a vacuum drift tube and is modulated to initiate electron bunching within the beam. The beam is then directed through a low-density gas chamber which provides isolation between the vacuum modulator and the relativistic electron beam target. The relativistic beam is then applied to a high-density target plasma which typically comprises DT, DD, or similar thermonuclear gas at a density of 10.sup.17 to 10.sup.20 electrons per cubic centimeter. The target gas is ionized prior to application of the relativistic electron beam by means of a laser or other preionization source to form a plasma. Utilizing a relativistic electron beam with an individual particle energy exceeding 3 MeV, classical scattering by relativistic electrons passing through isolation foils is negligible. As a result, relativistic streaming instabilities are initiated within the high-density target plasma causing the relativistic electron beam to efficiently deposit its energy into a small localized region of the high-density plasma target.

  1. Conducting Source Water Assessments

    EPA Pesticide Factsheets

    This page presents background information on the source water assessment steps, the four steps of a source wter assessment, and how to use the results of an assessment to protect drinking water sources.

  2. Volume 2 - Point Sources

    EPA Pesticide Factsheets

    Point source emission reference materials from the Emissions Inventory Improvement Program (EIIP). Provides point source guidance on planning, emissions estimation, data collection, inventory documentation and reporting, and quality assurance/quality contr

  3. Nonpoint Source: Forestry

    EPA Pesticide Factsheets

    Sources of nonpoint source (NPS) pollution associated with forestry activities include removal of streamside vegetation, road construction and use, timber harvesting, and mechanical preparation for the planting of trees. Information resources.

  4. European Spallation Source

    NASA Astrophysics Data System (ADS)

    Eshraqi, Mohammad; McGinnis, David; Lindroos, Mats

    The following sections are included: * Neutron usage and historical background * Spallation * History of spallation sources * The ESS facility * The ESS linac * Beam physics * The front-end and the normal conducting linac * Superconducting linac * RF sources * Summary * References

  5. Source Water Quality Monitoring

    EPA Science Inventory

    Presentation will provide background information on continuous source water monitoring using online toxicity monitors and cover various tools available. Conceptual and practical aspects of source water quality monitoring will be discussed.

  6. Familiarity in Source Memory

    PubMed Central

    Mollison, Matthew V.; Curran, Tim

    2012-01-01

    Familiarity and recollection are thought to be separate processes underlying recognition memory. Event-related potentials (ERPs) dissociate these processes, with an early (approximately 300–500 ms) frontal effect relating to familiarity (the FN400) and a later (500–800 ms) parietal old/new effect relating to recollection. It has been debated whether source information for a studied item (i.e., contextual associations from when the item was previously encountered) is only accessible through recollection, or whether familiarity can contribute to successful source recognition. It has been shown that familiarity can assist in perceptual source monitoring when the source attribute is an intrinsic property of the item (e.g., an object’s surface color), but few studies have examined its contribution to recognizing extrinsic source associations. Extrinsic source associations were examined in three experiments involving memory judgments for pictures of common objects. In Experiment 1, source information was spatial and results suggested that familiarity contributed to accurate source recognition: the FN400 ERP component showed a source accuracy effect, and source accuracy was above chance for items judged to only feel familiar. Source information in Experiment 2 was an extrinsic color association; source accuracy was at chance for familiar items and the FN400 did not differ between correct and incorrect source judgments. Experiment 3 replicated the results using a within-subjects manipulation of spatial vs. color source. Overall, the results suggest that familiarity’s contribution to extrinsic source monitoring depends on the type of source information being remembered. PMID:22789677

  7. Investigating Primary Source Literacy

    ERIC Educational Resources Information Center

    Archer, Joanne; Hanlon, Ann M.; Levine, Jennie A.

    2009-01-01

    Primary source research requires students to acquire specialized research skills. This paper presents results from a user study testing the effectiveness of a Web guide designed to convey the concepts behind "primary source literacy". The study also evaluated students' strengths and weaknesses when conducting primary source research. (Contains 3…

  8. Extragalactic Radio Sources

    ERIC Educational Resources Information Center

    Kellerman, Kenneth I.

    1973-01-01

    Discusses new problems arising from the growing observational data through radio telescope arrays, involving the origin of radio sources, apparent superluminal velocities, conversion of radio sources to relativistic particles, and the nature of compact opaque and extended transparent sources. New physics may be needed to answer these cosmological…

  9. 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.

  10. Neuromagnetic source reconstruction

    SciTech Connect

    Lewis, P.S.; Mosher, J.C.; Leahy, R.M.

    1994-12-31

    In neuromagnetic source reconstruction, a functional map of neural activity is constructed from noninvasive magnetoencephalographic (MEG) measurements. The overall reconstruction problem is under-determined, so some form of source modeling must be applied. We review the two main classes of reconstruction techniques-parametric current dipole models and nonparametric distributed source reconstructions. Current dipole reconstructions use a physically plausible source model, but are limited to cases in which the neural currents are expected to be highly sparse and localized. Distributed source reconstructions can be applied to a wider variety of cases, but must incorporate an implicit source, model in order to arrive at a single reconstruction. We examine distributed source reconstruction in a Bayesian framework to highlight the implicit nonphysical Gaussian assumptions of minimum norm based reconstruction algorithms. We conclude with a brief discussion of alternative non-Gaussian approachs.

  11. Microwave ion source

    SciTech Connect

    Leung, Ka-Ngo; Reijonen, Jani; Thomae, Rainer W.

    2005-07-26

    A compact microwave ion source has a permanent magnet dipole field, a microwave launcher, and an extractor parallel to the source axis. The dipole field is in the form of a ring. The microwaves are launched from the middle of the dipole ring using a coaxial waveguide. Electrons are heated using ECR in the magnetic field. The ions are extracted from the side of the source from the middle of the dipole perpendicular to the source axis. The plasma density can be increased by boosting the microwave ion source by the addition of an RF antenna. Higher charge states can be achieved by increasing the microwave frequency. A xenon source with a magnetic pinch can be used to produce intense EUV radiation.

  12. Dynamic radioactive particle source

    DOEpatents

    Moore, Murray E; Gauss, Adam Benjamin; Justus, Alan Lawrence

    2012-06-26

    A method and apparatus for providing a timed, synchronized dynamic alpha or beta particle source for testing the response of continuous air monitors (CAMs) for airborne alpha or beta emitters is provided. The method includes providing a radioactive source; placing the radioactive source inside the detection volume of a CAM; and introducing an alpha or beta-emitting isotope while the CAM is in a normal functioning mode.

  13. Rf power sources

    SciTech Connect

    Allen, M.A.

    1988-05-01

    This paper covers RF power sources for accelerator applications. The approach has been with particular customers in mind. These customers are high energy physicists who use accelerators as experimental tools in the study of the nucleus of the atom, and synchrotron light sources derived from electron or positron storage rings. This paper is confined to electron-positron linear accelerators since the RF sources have always defined what is possible to achieve with these accelerators. 11 refs., 13 figs.

  14. Radioisotopic heat source

    DOEpatents

    Sayell, E.H.

    1973-10-23

    A radioisotopic heat source is described which includes a core of heat productive, radioisotopic material, an impact resistant layer of graphite surrounding said core, and a shell of iridium metal intermediate the core and the impact layer. The source may also include a compliant mat of iridium between the core and the iridium shell, as well as an outer covering of iridium metal about the entire heat source. (Official Gazette)

  15. Sources of atmospheric ammonia

    NASA Technical Reports Server (NTRS)

    Harriss, R. C.; Michaels, J. T.

    1982-01-01

    The information available on factors that influence emissions from the principal societal sources of ammonia to the atmosphere, namely combustion processes, volatilization of farm animal wastes, and volatilization of fertilizers, is reviewed. Emission factors are established for each major source of atmospheric ammonia. The factors are then multiplied by appropriate source characterization descriptors to obtain calculated fluxes of ammonia to the atmosphere on a state-by-state basis for the United States.

  16. Pulsed spallation Neutron Sources

    SciTech Connect

    Carpenter, J.M.

    1994-12-31

    This paper reviews the early history of pulsed spallation neutron source development at Argonne and provides an overview of existing sources world wide. A number of proposals for machines more powerful than currently exist are under development, which are briefly described. The author reviews the status of the Intense Pulsed Neutron Source, its instrumentation, and its user program, and provides a few examples of applications in fundamental condensed matter physics, materials science and technology.

  17. Pulsed spallation neutron sources

    SciTech Connect

    Carpenter, J.M.

    1996-05-01

    This paper reviews the early history of pulsed spallation neutron source development ar Argonne and provides an overview of existing sources world wide. A number of proposals for machines more powerful than currently exist are under development, which are briefly described. The author reviews the status of the Intense Pulsed Neutron Source, its instrumentation, and its user program, and provide a few examples of applications in fundamental condensed matter physics, materials science and technology.

  18. Source and replica calculations

    SciTech Connect

    Whalen, P.P.

    1994-02-01

    The starting point of the Hiroshima-Nagasaki Dose Reevaluation Program is the energy and directional distributions of the prompt neutron and gamma-ray radiation emitted from the exploding bombs. A brief introduction to the neutron source calculations is presented. The development of our current understanding of the source problem is outlined. It is recommended that adjoint calculations be used to modify source spectra to resolve the neutron discrepancy problem.

  19. Temperature compensated current source

    NASA Technical Reports Server (NTRS)

    Breuer, D. R. (Inventor)

    1971-01-01

    A current source was designed which is substantially independent of variations of temperature. The current source may be made either to have a linear dependence upon changes of temperature or, by the simple addition of a resistor, may be made substantially independent of temperature variations. Since the current source consists only of transistors of one conductivity type and resistors, it is ideally suited for manufacture in the form of a monolithic integrated circuit.

  20. Nonpoint Source: Monitoring

    EPA Pesticide Factsheets

    Water quality monitoring for nonpoint sources of pollution includes the important element of relating the physical, chemical, and biological characteristics of receiving waters to land use characteristics.

  1. Improved ion source

    DOEpatents

    Leung, K.N.; Ehlers, K.W.

    1982-05-04

    A magnetic filter for an ion source reduces the production of undesired ion species and improves the ion beam quality. High-energy ionizing electrons are confined by the magnetic filter to an ion source region, where the high-energy electrons ionize gas molecules. One embodiment of the magnetic filter uses permanent magnets oriented to establish a magnetic field transverse to the direction of travel of ions from the ion source region to the ion extraction region. In another embodiment, low energy 16 eV electrons are injected into the ion source to dissociate gas molecules and undesired ion species into desired ion species,

  2. Energy Sources and Development.

    ERIC Educational Resources Information Center

    Crank, Ron

    This instructional unit is one of 10 developed by students on various energy-related areas that deals specifically with energy sources and development. Its objective is for the student to be able to discuss energy sources and development related to the historical perspective, biological development, current aspects, and future expectations…

  3. Open Source Molecular Modeling

    PubMed Central

    Pirhadi, Somayeh; Sunseri, Jocelyn; Koes, David Ryan

    2016-01-01

    The success of molecular modeling and computational chemistry efforts are, by definition, dependent on quality software applications. Open source software development provides many advantages to users of modeling applications, not the least of which is that the software is free and completely extendable. In this review we categorize, enumerate, and describe available open source software packages for molecular modeling and computational chemistry. PMID:27631126

  4. Noncontact Electromagnetic Vibration Source

    NASA Technical Reports Server (NTRS)

    Namkung, Min; Fulton, James P.; Wincheski, Buzz A.

    1994-01-01

    Metal aircraft skins scanned rapidly in vibration tests. Relatively simple combination of permanent magnets and electromagnet serves as noncontact vibration source for nondestructive testing of metal aircraft skins. In test, source excites vibrations, and vibration waveforms measured, then analyzed for changes in resonances signifying cracks and other flaws.

  5. 1972 Microfilm Source Book.

    ERIC Educational Resources Information Center

    1972

    The 1972 Microfilm Source Book has been designed to give sources of supply for important services and equipment related to microfilm. Events in the microfilm industry during 1971 are reviewed first, and a calendar is provided of major meetings and conferences held during 1972. The next section contains an index to products which lists them…

  6. Open Source Vision

    ERIC Educational Resources Information Center

    Villano, Matt

    2006-01-01

    Increasingly, colleges and universities are turning to open source as a way to meet their technology infrastructure and application needs. Open source has changed life for visionary CIOs and their campus communities nationwide. The author discusses what these technologists see as the benefits--and the considerations.

  7. Creating Open Source Conversation

    ERIC Educational Resources Information Center

    Sheehan, Kate

    2009-01-01

    Darien Library, where the author serves as head of knowledge and learning services, launched a new website on September 1, 2008. The website is built with Drupal, an open source content management system (CMS). In this article, the author describes how she and her colleagues overhauled the library's website to provide an open source content…

  8. Using Primary Source Documents.

    ERIC Educational Resources Information Center

    Mintz, Steven

    2003-01-01

    Explores the use of primary sources when teaching about U.S. slavery. Includes primary sources from the Gilder Lehrman Documents Collection (New York Historical Society) to teach about the role of slaves in the Revolutionary War, such as a proclamation from Lord Dunmore offering freedom to slaves who joined his army. (CMK)

  9. Fifth generation light sources

    NASA Astrophysics Data System (ADS)

    Romaniuk, Ryszard S.

    2016-12-01

    Coherent light sources are one of the most fundamental research tools in biology, technology and in other areas. Synchrotron light source consists of a few basic parts: energy source - which is an electron beam accelerator, energy converter between electron and photon beams - which is an undulator, and photon user experimental lines. Each of these parts is separately a complex system, which is currently a subject to fast technological development. Future light sources of the fifth generation are based on completely new solutions of these fundamental parts, in comparison with the sources of the previous generations. Energy source is a new generation laser - plasma accelerator with electrical field in the area of multiple GV/m. A miniature undulator is tested in the MEMS technology from new materials. Classical light beam lines, vacuum, and difficult for management and beam distribution, change their meaning in the case of availability of miniature undulators positioned immediately at or even inside the experimental stations. After an introduction concerning the light sources of the previous generations, the article shows current research efforts on the mentioned key components of the fifth generation light sources. In some cases this is a continuation and modernization of the previous technologies, in the majority it is a brave endeavour to apply completely new technologies, like laser - plasma acceleration.

  10. Nonpoint Source Pollution.

    PubMed

    Ahmad, Zaki Uddin; Sakib, Salman; Gang, Daniel Dianchen

    2016-10-01

    Research advances on non-point source pollution in the year 2015 have been depicted in this review paper. Nonpoint source pollution is mainly caused by agricultural runoff, urban stormwater, and atmospheric deposition. Modeling techniques of NPS with different tools are reviewed in this article.

  11. New Source Performance Standards

    ERIC Educational Resources Information Center

    Jenkins, Richard E.; McCutchen, Gary D.

    1972-01-01

    This feature article outlines the concept and procedures followed in establishing performance standards for new emission sources and summarizes the standards that have been established to date. Five source catagories are enumerated: fossil fuel-fired steam generators, municipal incinerators, Portland cement plants, nitric acid plants, and sulfuric…

  12. Radioisotopic heat source

    DOEpatents

    Jones, G.J.; Selle, J.E.; Teaney, P.E.

    1975-09-30

    Disclosed is a radioisotopic heat source and method for a long life electrical generator. The source includes plutonium dioxide shards and yttrium or hafnium in a container of tantalum-tungsten-hafnium alloy, all being in a nickel alloy outer container, and subjected to heat treatment of from about 1570$sup 0$F to about 1720$sup 0$F for about one h. (auth)

  13. Crystallography: Sources of inspiration

    NASA Astrophysics Data System (ADS)

    McSweeney, Sean; Fromme, Petra

    2014-01-01

    Synchrotrons have long been the preferred X-ray sources for crystallography, but competition has arrived with the advent of X-ray free-electron lasers. A synchrotron expert and an advocate of free-electron lasers discuss the prospects of the respective source types for applications in structural biology.

  14. PORTABLE SOURCE OF RADIOACTIVITY

    DOEpatents

    Goertz, R.C.; Ferguson, K.R.; Rylander, E.W.; Safranski, L.M.

    1959-06-16

    A portable source for radiogiaphy or radiotherapy is described. It consists of a Tl/sup 170/ or Co/sup 60/ source mounted in a rotatable tungsten alloy plug. The plug rotates within a brass body to positions of safety or exposure. Provision is made for reloading and carrying the device safely. (T.R.H.)

  15. Radiation Source Replacement Workshop

    SciTech Connect

    Griffin, Jeffrey W.; Moran, Traci L.; Bond, Leonard J.

    2010-12-01

    This report summarizes a Radiation Source Replacement Workshop in Houston Texas on October 27-28, 2010, which provided a forum for industry and researchers to exchange information and to discuss the issues relating to replacement of AmBe, and potentially other isotope sources used in well logging.

  16. On source radiation

    NASA Technical Reports Server (NTRS)

    Levine, H.

    1980-01-01

    The power output from given sources is usually ascertained via an energy flux integral over the normal directions to a remote (far field) surface; an alternative procedure, which utilizes an integral that specifies the direct rate of working by the source on the resultant field, is described and illustrated for both point and continuous source distribution. A comparison between the respective procedures is made in the analysis of sound radiated from a periodic dipole source whose axis performs a periodic plane angular movement about a fixed direction. Thus, adopting a conventional approach, Sretenskii (1956) characterizes the rotating dipole in terms of an infinite number of stationary ones along a pari of orthogonal directions in the plane, and through the far field representation of the latter, arrives at a series development for the instantaneous radiated power, whereas the local manner of power calculation dispenses with the equivalent infinite aggregate of sources and yields a compact analytical result.

  17. Piezotube borehole seismic source

    DOEpatents

    Daley, Tom M; Solbau, Ray D; Majer, Ernest L

    2014-05-06

    A piezoelectric borehole source capable of permanent or semipermanent insertion into a well for uninterrupted well operations is described. The source itself comprises a series of piezoelectric rings mounted to an insulative mandrel internally sized to fit over a section of well tubing, the rings encased in a protective housing and electrically connected to a power source. Providing an AC voltage to the rings will cause expansion and contraction sufficient to create a sonic pulse. The piezoelectric borehole source fits into a standard well, and allows for uninterrupted pass-through of production tubing, and other tubing and electrical cables. Testing using the source may be done at any time, even concurrent with well operations, during standard production.

  18. Photonic crystal light source

    DOEpatents

    Fleming, James G.; Lin, Shawn-Yu; Bur, James A.

    2004-07-27

    A light source is provided by a photonic crystal having an enhanced photonic density-of-states over a band of frequencies and wherein at least one of the dielectric materials of the photonic crystal has a complex dielectric constant, thereby producing enhanced light emission at the band of frequencies when the photonic crystal is heated. The dielectric material can be a metal, such as tungsten. The spectral properties of the light source can be easily tuned by modification of the photonic crystal structure and materials. The photonic crystal light source can be heated electrically or other heating means. The light source can further include additional photonic crystals that exhibit enhanced light emission at a different band of frequencies to provide for color mixing. The photonic crystal light source may have applications in optical telecommunications, information displays, energy conversion, sensors, and other optical applications.

  19. Industrial ion source technology

    NASA Technical Reports Server (NTRS)

    Kaufman, H. R.

    1976-01-01

    A 30 cm electron bombardment ion source was designed and fabricated for micromachining and sputtering applications. This source has a multipole magnetic field that employs permanent magnets between permeable pole pieces. An average ion current density of 1 ma/sq cm with 500 eV argon ions was selected as a design operating condition. The ion beam at this operating condition was uniform and well collimated, with an average variation of plus or minus 5 percent over the center 20 cm of the beam at distances up to 30 cm from the ion source. A variety of sputtering applications were undertaken with a small 10 cm ion source to better understand the ion source requirements in these applications. The results of these experimental studies are also included.

  20. Neutron sources and applications

    SciTech Connect

    Price, D.L.; Rush, J.J.

    1994-01-01

    Review of Neutron Sources and Applications was held at Oak Brook, Illinois, during September 8--10, 1992. This review involved some 70 national and international experts in different areas of neutron research, sources, and applications. Separate working groups were asked to (1) review the current status of advanced research reactors and spallation sources; and (2) provide an update on scientific, technological, and medical applications, including neutron scattering research in a number of disciplines, isotope production, materials irradiation, and other important uses of neutron sources such as materials analysis and fundamental neutron physics. This report summarizes the findings and conclusions of the different working groups involved in the review, and contains some of the best current expertise on neutron sources and applications.

  1. Pulsed ion beam source

    DOEpatents

    Greenly, John B.

    1997-01-01

    An improved pulsed ion beam source having a new biasing circuit for the fast magnetic field. This circuit provides for an initial negative bias for the field created by the fast coils in the ion beam source which pre-ionize the gas in the source, ionize the gas and deliver the gas to the proper position in the accelerating gap between the anode and cathode assemblies in the ion beam source. The initial negative bias improves the interaction between the location of the nulls in the composite magnetic field in the ion beam source and the position of the gas for pre-ionization and ionization into the plasma as well as final positioning of the plasma in the accelerating gap. Improvements to the construction of the flux excluders in the anode assembly are also accomplished by fabricating them as layered structures with a high melting point, low conductivity material on the outsides with a high conductivity material in the center.

  2. Public Geospatial Data Sources

    NASA Astrophysics Data System (ADS)

    Nering, Konrad

    2013-12-01

    In recent years there has been tremendous progress in the field of software for managing geographic information (GIS - Geographic Information System). Data processing capabilities expand with every new version of GIS applications. Similarly, the processing power of computers to process and manage geographic data. Once we have got such a powerful tool, the question arises: where to get the relevant data from? There are many sources of data (public, paid for), but after closer examination it turns out that they are mostly processed data from other sources. In this article I will present the primary source of data that can be used to suit one's needs. All of these data are publicly available

  3. Pulsed ion beam source

    DOEpatents

    Greenly, John B.

    1996-01-01

    An improved magnetically-confined anode plasma pulsed ion beam source. Beam rotation effects and power efficiency are improved by a magnetic design which places the separatrix between the fast field flux structure and the slow field structure near the anode of the ion beam source, by a gas port design which localizes the gas delivery into the gap between the fast coil and the anode, by a pre-ionizer ringing circuit connected to the fast coil, and by a bias field means which optimally adjusts the plasma formation position in the ion beam source.

  4. CALUTRON ION SOURCE

    DOEpatents

    Lofgren, E.J.

    1959-02-17

    An improvement is described in ion source mechanisms whereby the source structure is better adapted to withstanid the ravages of heat, erosion, and deterioration concomitant with operation of an ion source of the calutron type. A pair of molybdenum plates define the exit opening of the arc chamber and are in thermal contact with the walls of the chamber. These plates are maintained at a reduced temperature by a pair of copper blocks in thermal conducting contact therewith to form subsequent diverging margins for the exit opening.

  5. Microfabricated diffusion source

    DOEpatents

    Oborny, Michael C.; Frye-Mason, Gregory C.; Manginell, Ronald P.

    2008-07-15

    A microfabricated diffusion source to provide for a controlled diffusion rate of a vapor comprises a porous reservoir formed in a substrate that can be filled with a liquid, a headspace cavity for evaporation of the vapor therein, a diffusion channel to provide a controlled diffusion of the vapor, and an outlet to release the vapor into a gas stream. The microfabricated diffusion source can provide a calibration standard for a microanalytical system. The microanalytical system with an integral diffusion source can be fabricated with microelectromechanical systems technologies.

  6. 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.

  7. Nonpoint Source: Agriculture

    EPA Pesticide Factsheets

    Agricultural runoff as a nonpoint source category of pollution. Resouces to learn more a bout conservation practices to reduce water quality impacts from storm water run off and ground water infiltration

  8. Sources of fiber (image)

    MedlinePlus

    ... to avoid constipation. Vegetables, fresh fruits (especially dried fruits) and whole wheat, bran, or oatmeal cereals are excellent sources of fiber. To reap the benefits of fiber, it is very important to drink ...

  9. Alternative fuel information sources

    SciTech Connect

    Not Available

    1994-06-01

    This short document contains a list of more than 200 US sources of information (Name, address, phone number, and sometimes contact) related to the use of alternative fuels in automobiles and trucks. Electric-powered cars are also included.

  10. AQUATOX Data Sources Documents

    EPA Pesticide Factsheets

    Contains the data sources for parameter values of the AQUATOX model including: a bibliography for the AQUATOX data libraries and the compendia of parameter values for US Army Corps of Engineers models.

  11. Air pollution source identification

    NASA Technical Reports Server (NTRS)

    Fordyce, J. S.

    1975-01-01

    The techniques available for source identification are reviewed: remote sensing, injected tracers, and pollutants themselves as tracers. The use of the large number of trace elements in the ambient airborne particulate matter as a practical means of identifying sources is discussed. Trace constituents are determined by sensitive, inexpensive, nondestructive, multielement analytical methods such as instrumental neutron activation and charged particle X-ray fluorescence. The application to a large data set of pairwise correlation, the more advanced pattern recognition-cluster analysis approach with and without training sets, enrichment factors, and pollutant concentration rose displays for each element is described. It is shown that elemental constituents are related to specific source types: earth crustal, automotive, metallurgical, and more specific industries. A field-ready source identification system based on time and wind direction resolved sampling is described.

  12. Air pollution source identification

    NASA Technical Reports Server (NTRS)

    Fordyce, J. S.

    1975-01-01

    Techniques for air pollution source identification are reviewed, and some results obtained with them are evaluated. Described techniques include remote sensing from satellites and aircraft, on-site monitoring, and the use of injected tracers and pollutants themselves as tracers. The use of a large number of trace elements in ambient airborne particulate matter as a practical means of identifying sources is discussed in detail. Sampling and analysis techniques are described, and it is shown that elemental constituents can be related to specific source types such as those found in the earth's crust and those associated with specific industries. Source identification sytems are noted which utilize charged particle X-ray fluorescence analysis of original field data.

  13. National Synchrotron Light Source

    ScienceCinema

    None

    2016-07-12

    A tour of Brookhaven's National Synchrotron Light Source (NSLS). The NSLS is one of the world's most widely used scientific research facilities, hosting more than 2,500 guest researchers each year. The NSLS provides intense beams of infrared, ultraviole

  14. Sodium and Food Sources

    MedlinePlus

    ... Disease Cholesterol High Blood Pressure Million Hearts® WISEWOMAN Sodium and Food Sources Recommend on Facebook Tweet Share ... food [PDF-867K] and how to reduce sodium. Sodium Reduction Is Challenging Types of food matter: More ...

  15. Volume 4 - Mobile Sources

    EPA Pesticide Factsheets

    Mobile source reference material for activity data collection from the Emissions Inventory Improvement Program (EIIP). Provides complete methods for collecting key inputs to onroad mobile and nonroad mobile emissions models.

  16. National Synchrotron Light Source

    SciTech Connect

    2009-03-10

    A tour of Brookhaven's National Synchrotron Light Source (NSLS). The NSLS is one of the world's most widely used scientific research facilities, hosting more than 2,500 guest researchers each year. The NSLS provides intense beams of infrared, ultraviole

  17. METHANE: INDUSTRIAL SOURCES

    EPA Science Inventory

    The chapter provides qualitative information on the magnitude of industrial sources of methane and, where possible, provides information to allow the reader to quantify methane emissions. One difficulty in quantifying methane emissions from industry is the inconsistent treatment ...

  18. National Synchrotron Light Source

    ScienceCinema

    BNL

    2016-07-12

    A tour of Brookhaven's National Synchrotron Light Source (NSLS), hosted by Associate Laboratory Director for Light Sources, Stephen Dierker. The NSLS is one of the world's most widely used scientific research facilities, hosting more than 2,500 guest researchers each year. The NSLS provides intense beams of infrared, ultraviolet, and x-ray light for basic and applied research in physics, chemistry, medicine, geophysics, environmental, and materials sciences.

  19. Diversification of energy sources

    NASA Technical Reports Server (NTRS)

    1975-01-01

    The concept of energy source diversification was introduced as a substitution conservation action. The current status and philosophy behind a diversification program is presented in the context of a national energy policy. Advantages, disadvantages (constraints), and methods of implementation for diversification are discussed. The energy source systems for diversification are listed and an example impact assessment is outlined which deals with the water requirements of the specific energy systems.

  20. Field emission electron source

    DOEpatents

    Zettl, Alexander Karlwalter; Cohen, Marvin Lou

    2000-01-01

    A novel field emitter material, field emission electron source, and commercially feasible fabrication method is described. The inventive field emission electron source produces reliable electron currents of up to 400 mA/cm.sup.2 at 200 volts. The emitter is robust and the current it produces is not sensitive to variability of vacuum or the distance between the emitter tip and the cathode. The novel emitter has a sharp turn-on near 100 volts.

  1. Source Inspection Scheduling Calendar

    NASA Technical Reports Server (NTRS)

    Hollis, Brayden

    2011-01-01

    Quality is an essential component for creating flight hardware travelling through space since the hardware is extremely expensive and cannot be reworked or repaired once launched. An important step in this process is ensuring the quality of hardware procured from Jet Propulsion Laboratory's (JPL) suppliers. An important element of determining supplier quality is source inspection. Source inspections are performed at suppliers' facilities by JPL employeesto ensure that hardware characteristics are acceptable before being covered up and/or delivered to JPL.

  2. Open source molecular modeling.

    PubMed

    Pirhadi, Somayeh; Sunseri, Jocelyn; Koes, David Ryan

    2016-09-01

    The success of molecular modeling and computational chemistry efforts are, by definition, dependent on quality software applications. Open source software development provides many advantages to users of modeling applications, not the least of which is that the software is free and completely extendable. In this review we categorize, enumerate, and describe available open source software packages for molecular modeling and computational chemistry. An updated online version of this catalog can be found at https://opensourcemolecularmodeling.github.io.

  3. Magnetron sputtering source

    DOEpatents

    Makowiecki, D.M.; McKernan, M.A.; Grabner, R.F.; Ramsey, P.B.

    1994-08-02

    A magnetron sputtering source for sputtering coating substrates includes a high thermal conductivity electrically insulating ceramic and magnetically attached sputter target which can eliminate vacuum sealing and direct fluid cooling of the cathode assembly. The magnetron sputtering source design results in greater compactness, improved operating characteristics, greater versatility, and low fabrication cost. The design easily retrofits most sputtering apparatuses and provides for safe, easy, and cost effective target replacement, installation, and removal. 12 figs.

  4. Magnetron sputtering source

    DOEpatents

    Makowiecki, Daniel M.; McKernan, Mark A.; Grabner, R. Fred; Ramsey, Philip B.

    1994-01-01

    A magnetron sputtering source for sputtering coating substrates includes a high thermal conductivity electrically insulating ceramic and magnetically attached sputter target which can eliminate vacuum sealing and direct fluid cooling of the cathode assembly. The magnetron sputtering source design results in greater compactness, improved operating characteristics, greater versatility, and low fabrication cost. The design easily retrofits most sputtering apparatuses and provides for safe, easy, and cost effective target replacement, installation, and removal.

  5. HIGH VOLTAGE ION SOURCE

    DOEpatents

    Luce, J.S.

    1960-04-19

    A device is described for providing a source of molecular ions having a large output current and with an accelerated energy of the order of 600 kv. Ions are produced in an ion source which is provided with a water-cooled source grid of metal to effect maximum recombination of atomic ions to molecular ions. A very high accelerating voltage is applied to withdraw and accelerate the molecular ions from the source, and means are provided for dumping the excess electrons at the lowest possible potentials. An accelerating grid is placed adjacent to the source grid and a slotted, grounded accelerating electrode is placed adjacent to the accelerating grid. A potential of about 35 kv is maintained between the source grid and accelerating grid, and a potential of about 600 kv is maintained between the accelerating grid and accelerating electrode. In order to keep at a minimum the large number of oscillating electrons which are created when such high voltages are employed in the vicinity of a strong magnetic field, a plurality of high voltage cascaded shields are employed with a conventional electron dumping system being employed between each shield so as to dump the electrons at the lowest possible potential rather than at 600 kv.

  6. Light Sources 2007

    NASA Astrophysics Data System (ADS)

    Liu, M. Q.; Devonshire, R.

    2007-04-01

    This volume contains the proceedings of the 11th International Symposium on the Science and Technology of Light Sources (LS:11) held in Fudan University, Shanghai, China in the period May 20th to 24th, 2007. In the 32 years since the first symposium was held in Loughborough, UK, the LS series has established itself as the major international event which brings together on a regular basis the world's leading scientists and engineers involved in the research and development of light source technologies. The participants come from the R&D laboratories of the world’s leading light source manufacturing companies and from research groups in universities, government laboratories and research institutes. The highly multi-disciplinary nature of the field results in a unique mix of physicists, chemists, chemical physicists, materials scientists and electrical, electronic and mechanical engineers attending the symposia. The more than 250 papers in these LS:11 proceedings provide an excellent overview of the current status of light source science and technology. The energy efficiency and light emission characteristics of existing technologies continue to be improved, solid state technologies are advancing rapidly and innovation flourishes generally. Audience Professional scientists and engineers involved in light source related R&D. Postgraduate-level students in the physical sciences, applied mathematics, materials science, and electrical and electronic engineering. The contents will also be of interest to anyone with a background in science and engineering wishing to gain an overview of current activity in this important global industry and research field.

  7. Pulsed ion beam source

    DOEpatents

    Greenly, J.B.

    1997-08-12

    An improved pulsed ion beam source is disclosed having a new biasing circuit for the fast magnetic field. This circuit provides for an initial negative bias for the field created by the fast coils in the ion beam source which pre-ionize the gas in the source, ionize the gas and deliver the gas to the proper position in the accelerating gap between the anode and cathode assemblies in the ion beam source. The initial negative bias improves the interaction between the location of the nulls in the composite magnetic field in the ion beam source and the position of the gas for pre-ionization and ionization into the plasma as well as final positioning of the plasma in the accelerating gap. Improvements to the construction of the flux excluders in the anode assembly are also accomplished by fabricating them as layered structures with a high melting point, low conductivity material on the outsides with a high conductivity material in the center. 12 figs.

  8. COASTING ARC ION SOURCE

    DOEpatents

    Foster, J.S. Jr.

    1957-09-10

    An improved ion source is described and in particular a source in which the ions are efficiently removed. The plasma is generated in a tubular amode structure by the oscillation of electrons in an axial magnetic field, as in the Phillips Ion Gage. The novel aspect of the source is the expansion of the plasma as it leaves the anode structure, so as to reduce the ion density at the axis of the anode and present a uniform area of plasma to an extraction grid. The structure utilized in the present patent to expand the plasma comprises flange members of high permeability at the exitgrid end of the amode to diverge the magnetic field adjacent the exit.

  9. Dual source heat pump

    DOEpatents

    Ecker, Amir L.; Pietsch, Joseph A.

    1982-01-01

    What is disclosed is a heat pump apparatus for conditioning a fluid characterized by a fluid handler and path for circulating the fluid in heat exchange relationship with a refrigerant fluid; at least two refrigerant heat exchangers, one for effecting heat exchange with the fluid and a second for effecting heat exchange between refrigerant and a heat exchange fluid and the ambient air; a compressor for efficiently compressing the refrigerant; at least one throttling valve for throttling liquid refrigerant; a refrigerant circuit; refrigerant; a source of heat exchange fluid; heat exchange fluid circulating device and heat exchange fluid circuit for circulating the heat exchange fluid in heat exchange relationship with the refrigerant; and valves or switches for selecting the heat exchangers and direction of flow of the refrigerant therethrough for selecting a particular mode of operation. The heat exchange fluid provides energy for defrosting the second heat exchanger when operating in the air source mode and also provides a alternate source of heat.

  10. Modulated infrared radiant source

    NASA Technical Reports Server (NTRS)

    Stewart, W. F.; Edwards, S. F.; Vann, D. S.; Mccormick, R. F.

    1981-01-01

    A modulated, infrared radiant energy source was developed to calibrate an airborne nadir-viewing pressure modulated radiometer to be used to detect from Earth orbit trace gases in the troposphere. The technique used an 8 cm long, 0.005 cm diameter platinum-iridium wire as an isothermal, thin line radiant energy source maintained at 1200 K. A + or - 20 K signal, oscillating at controllable frequencies from dc to 20 Hz, was superimposed on it. This periodic variation of the line source energy was used to verify the pressure modulated radiometer's capability to distinguish between the signal variations caused by the Earth's background surface and the signal from the atmospheric gases of interest.

  11. MEMS Incandescent Light Source

    NASA Technical Reports Server (NTRS)

    Tuma, Margaret; King, Kevin; Kim, Lynn; Hansler, Richard; Jones, Eric; George, Thomas

    2001-01-01

    A MEMS-based, low-power, incandescent light source is being developed. This light source is fabricated using three bonded chips. The bottom chip consists of a reflector on Silicon, the middle chip contains a Tungsten filament bonded to silicon and the top layer is a transparent window. A 25-micrometer-thick spiral filament is fabricated in Tungsten using lithography and wet-etching. A proof-of-concept device has been fabricated and tested in a vacuum chamber. Results indicate that the filament is electrically heated to approximately 2650 K. The power required to drive the proof-of-concept spiral filament to incandescence is 1.25 W. The emitted optical power is expected to be approximately 1.0 W with the spectral peak at 1.1 microns. The micromachining techniques used to fabricate this light source can be applied to other MEMS devices.

  12. Italian neutron sources

    NASA Astrophysics Data System (ADS)

    Prata, M.; Alloni, D.; De Felice, P.; Palomba, M.; Pietropaolo, A.; Pillon, M.; Quintieri, L.; Santagata, A.; Valente, P.

    2014-11-01

    Many research activities, instrumental analysis, studies of radiation damage, etc., require neutron sources. The main neutron sources present in Italy are described in three different sections: nuclear research reactors, accelerator driven, and metrology stations. The nuclear research reactors of LENA (University of Pavia) and ENEA Casaccia are described in terms of irradiation facilities available, neutron flux for each of them and the main activities carried out by each research centre. In the second section, the Frascati Neutron Generator (FNG), the Frascati Beam-Test Facility (BTF) and their main features are reported. In the last section there is a detailed description of the institutional role and the main activities carried out in the field of neutron metrology by the National Institute for Metrology of Ionizing Radiation (INMRI) with a brief description of neutron sources of which the institute is endowed.

  13. INEEL Source Water Assessment

    SciTech Connect

    Sehlke, Gerald

    2003-03-01

    The Idaho National Engineering and Environmental Laboratory (INEEL) covers approximately 890 mi2 and includes 12 public water systems that must be evaluated for Source water protection purposes under the Safe Drinking Water Act. Because of its size and location, six watersheds and five aquifers could potentially affect the INEEL’s drinking water sources. Based on a preliminary evaluation of the available information, it was determined that the Big Lost River, Birch Creek, and Little Lost River Watersheds and the eastern Snake River Plain Aquifer needed to be assessed. These watersheds were delineated using the United States Geologic Survey’s Hydrological Unit scheme. Well capture zones were originally estimated using the RESSQC module of the Environmental Protection Agency’s Well Head Protection Area model, and the initial modeling assumptions and results were checked by running several scenarios using Modflow modeling. After a technical review, the resulting capture zones were expanded to account for the uncertainties associated with changing groundwater flow directions, a thick vadose zone, and other data uncertainties. Finally, all well capture zones at a given facility were merged to a single wellhead protection area at each facility. A contaminant source inventory was conducted, and the results were integrated with the well capture zones, watershed and aquifer information, and facility information using geographic information system technology to complete the INEEL’s Source Water Assessment. Of the INEEL’s 12 public water systems, three systems rated as low susceptibility (EBR-I, Main Gate, and Gun Range), and the remainder rated as moderate susceptibility. No INEEL public water system rated as high susceptibility. We are using this information to develop a source water management plan from which we will subsequently implement an INEEL-wide source water management program. The results are a very robust set of wellhead protection areas that will

  14. 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.

  15. Trends in source gases

    NASA Technical Reports Server (NTRS)

    Ehhalt, D. H.; Fraser, P. J.; Albritton, D.; Cicerone, R. J.; Khalil, M. A. K.; Legrand, M.; Makide, Y.; Rowland, F. S.; Steele, L. P.; Zander, R.

    1989-01-01

    Source gases are defined as those gases that, by their breakdown, introduce into the stratosphere halogen, hydrogen, and nitrogen compounds that are important in stratospheric ozone destruction. Given here is an update of the existing concentration time series for chlorocarbons, nitrous oxide, and methane. Also reviewed is information on halogen containing species and the use of these data for establishing trends. Also reviewed is evidence on trends in trace gases that influence tropospheric chemistry and thus the tropospheric lifetimes of source gases, such as carbon dioxide, carbon monoxide, or nitrogen oxides. Much of the information is given in tabular form.

  16. Milliwatt generator heat source

    NASA Astrophysics Data System (ADS)

    Mershad, E. A.

    1984-03-01

    All LANL hardware requirements were met during the reporting period as scheduled. Lot 12 of T-111 alloy sheet and Lot 8 of yttrium platelets were procured to meet future WR production needs. The GEND IP schedule requirements for 49 fueled MC2893 heat sources were met. Pressure burst surveillance activities continued to be conducted in accordance with SNLA document BB328965. Final results of evaluations of two pressure-burst capsules were normal, suggesting that the corresponding heat sources should be in good condition. The hardware production period ended with an overall hardware process yield of 98.4%.

  17. FABRICATION OF NEUTRON SOURCES

    DOEpatents

    Birden, J.H.

    1959-04-21

    A method is presented for preparing a neutron source from polonium-210 and substances, such as beryllium and boron, characterized by emission of neutrons upon exposure to alpha particles from the polonium. According to the invention, a source is prepared by placing powdered beryllium and a platinum foil electroplated with polonium-2;.0 in a beryllium container. The container is sealed and then heated by induction to a temperature of 450 to 1100 deg C to volatilize the polonium off the foil into the powder. The heating step is terminated upon detection of a maximum in the neutron flux level.

  18. OLED area illumination source

    DOEpatents

    Foust, Donald Franklin; Duggal, Anil Raj; Shiang, Joseph John; Nealon, William Francis; Bortscheller, Jacob Charles

    2008-03-25

    The present invention relates to an area illumination light source comprising a plurality of individual OLED panels. The individual OLED panels are configured in a physically modular fashion. Each OLED panel comprising a plurality of OLED devices. Each OLED panel comprises a first electrode and a second electrode such that the power being supplied to each individual OLED panel may be varied independently. A power supply unit capable of delivering varying levels of voltage simultaneously to the first and second electrodes of each of the individual OLED panels is also provided. The area illumination light source also comprises a mount within which the OLED panels are arrayed.

  19. Radially uniform electron source

    NASA Technical Reports Server (NTRS)

    Mccomas, D.; Bame, S. J.

    1982-01-01

    A thermionic electron source capable of producing uniform count rates in a number of channel electron multipliers simultaneously was required for conditioning multipliers for an extended space mission. It was found that a straight tungsten filament in the center of a cylindrically symmetric geometry surrounded by an array of multipliers emits a radially asymmetric distribution of electrons that changes with time. A source was developed which successfully produces a time-independent radially uniform distribution of electrons by moving the filament out of the direct line of sight and replacing it with a centrally located electron 'cloud.'

  20. Open-Source Colorimeter

    PubMed Central

    Anzalone, Gerald C.; Glover, Alexandra G.; Pearce, Joshua M.

    2013-01-01

    The high cost of what have historically been sophisticated research-related sensors and tools has limited their adoption to a relatively small group of well-funded researchers. This paper provides a methodology for applying an open-source approach to design and development of a colorimeter. A 3-D printable, open-source colorimeter utilizing only open-source hardware and software solutions and readily available discrete components is discussed and its performance compared to a commercial portable colorimeter. Performance is evaluated with commercial vials prepared for the closed reflux chemical oxygen demand (COD) method. This approach reduced the cost of reliable closed reflux COD by two orders of magnitude making it an economic alternative for the vast majority of potential users. The open-source colorimeter demonstrated good reproducibility and serves as a platform for further development and derivation of the design for other, similar purposes such as nephelometry. This approach promises unprecedented access to sophisticated instrumentation based on low-cost sensors by those most in need of it, under-developed and developing world laboratories. PMID:23604032

  1. Coaxial microwave plasma source

    SciTech Connect

    Gritsinin, S. I.; Gushchin, P. A.; Davydov, A. M.; Kossyi, I. A.; Kotelev, M. S.

    2011-11-15

    Physical principles underlying the operation of a pulsed coaxial microwave plasma source (micro-wave plasmatron) are considered. The design and parameters of the device are described, and results of experimental studies of the characteristics of the generated plasma are presented. The possibility of application of this type of plasmatron in gas-discharge physics is discussed.

  2. Candlestick rubidium beam source

    NASA Astrophysics Data System (ADS)

    Walkiewicz, M. R.; Fox, P. J.; Scholten, R. E.

    2000-09-01

    We describe a long-lived, bright and intense rubidium atomic beam source based on a previously published recirculating candlestick design for sodium, with several modifications and enhancements. The device operates for thousands of hours without maintenance, with brightness of 1.9×1022 m-2 s-1 sr-1.

  3. Open Source in Education

    ERIC Educational Resources Information Center

    Lakhan, Shaheen E.; Jhunjhunwala, Kavita

    2008-01-01

    Educational institutions have rushed to put their academic resources and services online, beginning the global community onto a common platform and awakening the interest of investors. Despite continuing technical challenges, online education shows great promise. Open source software offers one approach to addressing the technical problems in…

  4. Selective ion source

    DOEpatents

    Leung, K.N.

    1996-05-14

    A ion source is described wherein selected ions maybe extracted to the exclusion of unwanted ion species of higher ionization potential. Also described is a method of producing selected ions from a compound, such as P{sup +} from PH{sub 3}. The invention comprises a plasma chamber, an electron source, a means for introducing a gas to be ionized by electrons from the electron source, means for limiting electron energy from the electron source to a value between the ionization energy of the selected ion species and the greater ionization energy of an unwanted ion specie, and means for extracting the target ion specie from the plasma chamber. In one embodiment, the electrons are generated in a plasma cathode chamber immediately adjacent to the plasma chamber. A small extractor draws the electrons from the plasma cathode chamber into the relatively positive plasma chamber. The energy of the electrons extracted in this manner is easily controlled. The invention is particularly useful for doping silicon with P{sup +}, As{sup +}, and B{sup +} without the problematic presence of hydrogen, helium, water, or carbon oxide ions. Doped silicon is important for manufacture of semiconductors and semiconductor devices. 6 figs.

  5. Detecting Illicit Radioactive Sources

    SciTech Connect

    McDonald, Joseph C.; Coursey, Bert; Carter, Michael

    2004-11-01

    Specialized instruments have been developed to detect the presence of illicit radioactive sources that may be used by terrorists in radiation dispersal devices, so-called ''dirty bombs'' or improvised nuclear devices. This article discusses developments in devices to detect and measure radiation.

  6. Does Source Reduction Work?

    ERIC Educational Resources Information Center

    Allaway, David

    1992-01-01

    Suggests that quantification is essential to establish the cost-effectiveness of source reduction (SR). Presents case studies of monitoring methods for seven different kinds of SR efforts: (1) packaging changes, (2) SR businesses, (3) waste exchanges, (4) individual nonresidential efforts, (5) variable garbage rates, (6) yard waste reduction, and…

  7. MICROBIAL SOURCE TRACKING

    EPA Science Inventory

    Fecal contamination of waters used for recreation, drinking water, and aquaculture is an environmental problem and poses significant human health risks. The problem is often difficult to correct because the source of the contamination cannot be determined with certainty. Run-of...

  8. Custom uniform source system

    NASA Technical Reports Server (NTRS)

    Balcom, John L.

    1994-01-01

    The purpose and scope of this final report is to provide information on the Custom Uniform Source System (CSTM-USS-4000). The report includes documentation and summaries of the results for the work performed under the contract. The Annex contain laboratory test findings, photographs, and drawings of the sphere system.

  9. Poetry: Sources for Criticism.

    ERIC Educational Resources Information Center

    Van Noate, Judith, Comp.

    This handout is a guide to library resources in the J. Murrey Atkins Library at the University of North Carolina-Charlotte for the criticism of poetry. The guide enables the reader to find sources of criticism on poetry, including critical articles and essays about single poems, or writings on the work of a single author. The guide's sections…

  10. Evaluating Open Source Portals

    ERIC Educational Resources Information Center

    Goh, Dion; Luyt, Brendan; Chua, Alton; Yee, See-Yong; Poh, Kia-Ngoh; Ng, How-Yeu

    2008-01-01

    Portals have become indispensable for organizations of all types trying to establish themselves on the Web. Unfortunately, there have only been a few evaluative studies of portal software and even fewer of open source portal software. This study aims to add to the available literature in this important area by proposing and testing a checklist for…

  11. Selective ion source

    DOEpatents

    Leung, Ka-Ngo

    1996-01-01

    A ion source is described wherein selected ions maybe extracted to the exclusion of unwanted ion species of higher ionization potential. Also described is a method of producing selected ions from a compound, such as P.sup.+ from PH.sub.3. The invention comprises a plasma chamber, an electron source, a means for introducing a gas to be ionized by electrons from the electron source, means for limiting electron energy from the electron source to a value between the ionization energy of the selected ion species and the greater ionization energy of an unwanted ion specie, and means for extracting the target ion specie from the plasma chamber. In one embodiment, the electrons are generated in a plasma cathode chamber immediately adjacent to the plasma chamber. A small extractor draws the electrons from the plasma cathode chamber into the relatively positive plasma chamber. The energy of the electrons extracted in this manner is easily controlled. The invention is particularly useful for doping silicon with P.sup.+, AS.sup.+, and B.sup.+ without the problematic presence of hydrogen, helium, water, or carbon oxide ions. Doped silicon is important for manufacture of semiconductors and semiconductor devices.

  12. Sources of Assistance.

    ERIC Educational Resources Information Center

    Wood, Douglas

    This module is one of a set of seven prepared in conjunction with the Title I "Project to Train Volunteer Leaders to Conduct Consumer Education Courses." It is designed to be a basic text for use in making a one-hour presentation on sources of consumer assistance. Topics include consumers' alternatives for self-help, functions of the…

  13. Incoherent Light Sources

    NASA Astrophysics Data System (ADS)

    Bertram, Dietrich; Born, Matthias; Jüstel, Thomas

    Since the invention and industrialization of incandescent lamps at the end radiation of the 19th century electrical lighting has become a commodity in our daily life. Today, incoherent light sources are used for numerous application areas. Major improvements have been achieved over the past decades with respect to lamp efficiency (Fig. 10.1), lifetime and color properties.

  14. Incoherent Light Sources

    NASA Astrophysics Data System (ADS)

    Bertram, Dietrich; Born, Matthias; Jüstel, Thomas

    Since the invention and industrialization of incandescent lamps at the end of the 19th century electrical lighting has become a commodity in our daily life. Today, incoherent light sources are used for numerous application areas. Major improvements have been achieved over the past decades with respect to lamp efficiency Fig. 10.1, lifetime and color properties.

  15. Selected Current Data Sources.

    ERIC Educational Resources Information Center

    DeBrock, Larry M.

    1987-01-01

    Lists 55 free or inexpensive periodicals which may be used to provide current data for undergraduate economics courses. The list is divided into standard sources, federal reserve publications, selected bank newsletters, selected government newsletters, selected not-for-profit institutions, and miscellaneous. (JDH)

  16. Square Source Type Diagram

    NASA Astrophysics Data System (ADS)

    Aso, N.; Ohta, K.; Ide, S.

    2014-12-01

    Deformation in a small volume of earth interior is expressed by a symmetric moment tensor located on a point source. The tensor contains information of characteristic directions, source amplitude, and source types such as isotropic, double-couple, or compensated-linear-vector-dipole (CLVD). Although we often assume a double couple as the source type of an earthquake, significant non-double-couple component including isotropic component is often reported for induced earthquakes and volcanic earthquakes. For discussions on source types including double-couple and non-double-couple components, it is helpful to display them using some visual diagrams. Since the information of source type has two degrees of freedom, it can be displayed onto a two-dimensional flat plane. Although the diagram developed by Hudson et al. [1989] is popular, the trace corresponding to the mechanism combined by two mechanisms is not always a smooth line. To overcome this problem, Chapman and Leaney [2012] developed a new diagram. This diagram has an advantage that a straight line passing through the center corresponds to the mechanism obtained by a combination of an arbitrary mechanism and a double-couple [Tape and Tape, 2012], but this diagram has some difficulties in use. First, it is slightly difficult to produce the diagram because of its curved shape. Second, it is also difficult to read out the ratios among isotropic, double-couple, and CLVD components, which we want to obtain from the estimated moment tensors, because they do not appear directly on the horizontal or vertical axes. In the present study, we developed another new square diagram that overcomes the difficulties of previous diagrams. This diagram is an orthogonal system of isotropic and deviatoric axes, so it is easy to get the ratios among isotropic, double-couple, and CLVD components. Our diagram has another advantage that the probability density is obtained simply from the area within the diagram if the probability density

  17. THz Local Oscillator Sources

    NASA Astrophysics Data System (ADS)

    Mehdi, Imran; Schlecht, Erich; Chattopadhyay, Goutam; Siegel, Peter H.

    Most operational Submillimeter-wave radio telescopes, both space borne and ground based, employ local oscillator sources based on Gunn diodes followed by whisker contacted Schottky multipliers. Enough progress, however, has been made on a number of fronts to conclude that next generation of radio telescopes that become operational in the new Millennium will have a different local oscillator (LO) generation architecture. MMIC power amplifiers with impressive gain in the Ka- to-W band have enabled the use of microwave synthesizers which can then be actively multiplied to provide a frequency agile power source beyond 100 GHz. This medium power millimeter source can then be amplified to enable efficient pumping of follow-on balanced multiplier stages. Input power to the multipliers can be further enhanced by power combining to achieve close to half a Watt at W-band. An 800 GHz three-stage multiplier chain, implemented this way has demonstrated a peak output power of 1 mW. A second advance in LO generation lies in the Schottky diode varactor technology. Planar Schottky diode multipliers have now been demonstrated up to 1500 GHz and it can be assumed that most of the future multiplier chains will be based on these robust devices rather than the whisker contacted diode of the past. The ability to produce planar GaAs diode chips deep into the THz range, with submicron dimensions, has opened up a wide range of circuit design space which can be taken advantage of to improve efficiency, bandwidth, and power handling capability of the multipliers. A third breakthrough has been the demonstration of photonic based LO sources utilizing GaAs photomixers. These sources, though not yet implemented in robust space borne missions, offer a number of advantages over their electronic counterparts, including extremely broad tuning, fiber coupled components, and solid-state implementation. Another development, which holds some promise, is the use of micro-machining technology to implement

  18. Laser Synchrotron Source (LSS)

    NASA Astrophysics Data System (ADS)

    Sprangle, Philip; Ting, Antonio; Esarey, Eric; Fisher, Amon; Mourou, Gerald

    1993-02-01

    The Laser Synchrotron Source (LSS) utilizes a high peak power or high average power laser to generate within a vacuum chamber a laser beam travelling in one direction to interact with an electron beam traveling in an opposite direction in order to generate high-power x-rays. A ring resonator formed by a plurality of mirrors directs the laser beam in a closed loop to impact with the electron beam to produce x-rays. Concave mirrors in the ring resonator focus the laser beam upon the point where the laser beam interacts with the electron beam to intensify the laser energy at that point. When a Radio Frequency Linear Accelerator (RF linac) is used to produce the electron beam, x-rays having a short pulse length are generated. When a betatron is used as an electron source, x-rays having a long pulse length are generated.

  19. Evaluated teletherapy source library

    DOEpatents

    Cox, Lawrence J.; Schach Von Wittenau, Alexis E.

    2000-01-01

    The Evaluated Teletherapy Source Library (ETSL) is a system of hardware and software that provides for maintenance of a library of useful phase space descriptions (PSDs) of teletherapy sources used in radiation therapy for cancer treatment. The PSDs are designed to be used by PEREGRINE, the all-particle Monte Carlo dose calculation system. ETSL also stores other relevant information such as monitor unit factors (MUFs) for use with the PSDs, results of PEREGRINE calculations using the PSDs, clinical calibration measurements, and geometry descriptions sufficient for calculational purposes. Not all of this information is directly needed by PEREGRINE. It also is capable of acting as a repository for the Monte Carlo simulation history files from which the generic PSDs are derived.

  20. Ultraviolet laser excitation source

    NASA Technical Reports Server (NTRS)

    Lee, J. H.; Mcfarland, D. R.; Hohl, F.

    1980-01-01

    A new intense ultraviolet light source has been developed from an array of hypocycloidal pinch (HCP) devices. The basic unit of the array is constructed with three disk electrodes and is capable of producing dense plasmas at temperatures up to 10,000,000 K. Very high input power levels to the array are possible without significantly shortening its useful life, in strong contrast with conventional xenon flashlamps. The new light source, when operated with Ar and Xe gas mixtures at high pressures (approximately 5 x 10 to the 4th Pa), produced a light output of over 100 MW in the near-UV spectral range and successfully pumped an iodine photodissociation laser at 1.315 microns. A xenon recombination laser at 2.027 microns was also pumped in the HCP array.

  1. Mars Spark Source Prototype

    NASA Technical Reports Server (NTRS)

    Eichenberg, Dennis J.; Lindamood, Glenn R.; Weiland, Karen J.; VanderWal, Randall L.

    1999-01-01

    The Mars Spark Source Prototype (MSSP) hardware has been developed as part of a proof of concept system for the detection of trace metals such as lead, cadmium, and arsenic in Martian dusts and soils. A spark discharge produces plasma from a soil sample and detectors measure the optical emission from metals in the plasma that will allow their identification and quantification. Trace metal measurements are vital for the assessment of the potential toxicity of the Martian environment for human exploration. The current method of X-ray fluorescence can yield concentrations only of major species. Other instruments are incompatible with the volume, weight, and power constraints for a Mars mission. The instrument will be developed primarily for use in the Martian environment, but would be adaptable for terrestrial use in environmental monitoring. This paper describes the Mars Spark Source Prototype hardware, the results of the characterization tests, and future plans for hardware development.

  2. Alternative energy sources

    NASA Astrophysics Data System (ADS)

    Todd, R. W.

    1982-04-01

    Renewable energy sources and their potential contribution for solving energy needs are presented. Centralized supply technologies include those alternative fuels derived from biomass using solar energy, (supplying 57% of the energy supply in some countries), and those using directly collected solar energy to manufacture a fuel. Fuel utilization effects can be doubled by using combined heat and power stations, and other major sources include wind, wave, tidal, and solar. In terms of local supply technology, wood burning appliances are becoming more popular, and methane is being used for heating and to fuel spark ignition engines. Geothermal low temperature heating exists worldwide at a capacity of 7.2 GW, supplying heat, particularly in Hungary, parts of the U.S.S.R., and Iceland, and a geothermal research program has been established in the United States. Sweden has a potential hydroelectric capacity of 600 MW, and the United States has a 100 GW capacity. Many of these technologies are already cost effective.

  3. Terahertz sources and detectors

    NASA Astrophysics Data System (ADS)

    Crowe, Thomas W.; Porterfield, David W.; Hesler, Jeffrey L.; Bishop, William L.; Kurtz, David S.; Hui, Kai

    2005-05-01

    Through the support of the US Army Research Office we are developing terahertz sources and detectors suitable for use in the spectroscopy of chemical and biological materials as well as for use in imaging systems to detect concealed weapons. Our technology relies on nonlinear diodes to translate the functionality achieved at microwave frequencies to the terahertz band. Basic building blocks that have been developed for this application include low-noise mixers, frequency multipliers, sideband generators and direct detectors. These components rely on planar Schottky diodes and integrated diode circuits and are therefore easy to assemble and robust. They require no mechanical tuners to achieve high efficiency and broad bandwidth. This paper will review the range of performance that has been achieved with these terahertz components and briefly discuss preliminary results achieved with a spectroscopy system and the development of sources for imaging systems.

  4. Advanced light source

    NASA Astrophysics Data System (ADS)

    Sah, R. C.

    1983-03-01

    The Advanced Light Source (ALS) is a new synchrotron radiation source which was proposed by Lawrence Berkeley Laboratory. The ALS will be a key component in a major new research facility, the National Center for Advanced Materials. The ALS will consist of an electron linear accelerator, a booster synchrotron, a 1.3-GeV electron storage ring, and a number of photon beam lines. Most of all photon beam lines will originate from wiggler and undulator magnets placed in the 12 long straight sections of the ALS. A very low electron beam emittance will provide photon beams of unsurpassed spectral brilliance from specially-designed undulators, and a high radiofrequency will produce very short pulse lengths.

  5. Voltage controlled current source

    DOEpatents

    Casne, Gregory M.

    1992-01-01

    A seven decade, voltage controlled current source is described for use in testing intermediate range nuclear instruments that covers the entire test current range of from 10 picoamperes to 100 microamperes. High accuracy is obtained throughout the entire seven decades of output current with circuitry that includes a coordinated switching scheme responsive to the input signal from a hybrid computer to control the input voltage to an antilog amplifier, and to selectively connect a resistance to the antilog amplifier output to provide a continuous output current source as a function of a preset range of input voltage. An operator controlled switch provides current adjustment for operation in either a real-time simulation test mode or a time response test mode.

  6. The Advanced Photon Source

    SciTech Connect

    Galayda, John N.

    1996-01-01

    The Advanced Photon Source (APS) is a 7-GeV third-generation synchrotron radiation storage ring and full-energy positron injector. Construction project funding began in 1989, and ground breaking took place on 5 May 1990. Construction of all accelerator facilities was completed in January 1995 and storage ring commissioning is underway. First observation of x-rays from a bending magnet source took place on 26 March 1995. Nearly all performance specifications of the injector have been reached, and first observations indicate that the reliability, dynamic aperture, emittance, and orbit stability in the storage ring are satisfactory. Observation of radiation from the first of 20 insertion device beamlines is scheduled for October 1995. Start of regular operations is expected to take place well before the APS Project target date of December 1996.

  7. The advanced photon source

    SciTech Connect

    Galayda, J.N.

    1995-07-01

    The Advanced Photon Source (APS) is a 7-GeV third-generation synchrotron radiation storage ring and full-energy positron injector. Construction project funding began in 1989, and ground breaking took place on 5 May 1990. Construction of all accelerator facilities was completed in January 1995 and storage ring commissioning is underway. First observation of x-rays from a bending magnet source took place on 26 March 1995. Nearly all performance specifications of the injector have been reached, and first observations indicate that the reliability, dynamic aperture, emittance, and orbit stability in the storage ring are satisfactory. Observation of radiation from the first of 20 insertion device beamlines is scheduled for October 1995. Start of regular operations is expected to take place well before the APS Project target date of December 1996.

  8. Calibrated vapor generator source

    DOEpatents

    Davies, J.P.; Larson, R.A.; Goodrich, L.D.; Hall, H.J.; Stoddard, B.D.; Davis, S.G.; Kaser, T.G.; Conrad, F.J.

    1995-09-26

    A portable vapor generator is disclosed that can provide a controlled source of chemical vapors, such as, narcotic or explosive vapors. This source can be used to test and calibrate various types of vapor detection systems by providing a known amount of vapors to the system. The vapor generator is calibrated using a reference ion mobility spectrometer. A method of providing this vapor is described, as follows: explosive or narcotic is deposited on quartz wool, placed in a chamber that can be heated or cooled (depending on the vapor pressure of the material) to control the concentration of vapors in the reservoir. A controlled flow of air is pulsed over the quartz wool releasing a preset quantity of vapors at the outlet. 10 figs.

  9. Calibrated vapor generator source

    DOEpatents

    Davies, John P.; Larson, Ronald A.; Goodrich, Lorenzo D.; Hall, Harold J.; Stoddard, Billy D.; Davis, Sean G.; Kaser, Timothy G.; Conrad, Frank J.

    1995-01-01

    A portable vapor generator is disclosed that can provide a controlled source of chemical vapors, such as, narcotic or explosive vapors. This source can be used to test and calibrate various types of vapor detection systems by providing a known amount of vapors to the system. The vapor generator is calibrated using a reference ion mobility spectrometer. A method of providing this vapor is described, as follows: explosive or narcotic is deposited on quartz wool, placed in a chamber that can be heated or cooled (depending on the vapor pressure of the material) to control the concentration of vapors in the reservoir. A controlled flow of air is pulsed over the quartz wool releasing a preset quantity of vapors at the outlet.

  10. Filtered cathodic arc source

    DOEpatents

    Falabella, S.; Sanders, D.M.

    1994-01-18

    A continuous, cathodic arc ion source coupled to a macro-particle filter capable of separation or elimination of macro-particles from the ion flux produced by cathodic arc discharge is described. The ion source employs an axial magnetic field on a cathode (target) having tapered sides to confine the arc, thereby providing high target material utilization. A bent magnetic field is used to guide the metal ions from the target to the part to be coated. The macro-particle filter consists of two straight solenoids, end to end, but placed at 45[degree] to one another, which prevents line-of-sight from the arc spot on the target to the parts to be coated, yet provides a path for ions and electrons to flow, and includes a series of baffles for trapping the macro-particles. 3 figures.

  11. Filtered cathodic arc source

    DOEpatents

    Falabella, Steven; Sanders, David M.

    1994-01-01

    A continuous, cathodic arc ion source coupled to a macro-particle filter capable of separation or elimination of macro-particles from the ion flux produced by cathodic arc discharge. The ion source employs an axial magnetic field on a cathode (target) having tapered sides to confine the arc, thereby providing high target material utilization. A bent magnetic field is used to guide the metal ions from the target to the part to be coated. The macro-particle filter consists of two straight solenoids, end to end, but placed at 45.degree. to one another, which prevents line-of-sight from the arc spot on the target to the parts to be coated, yet provides a path for ions and electrons to flow, and includes a series of baffles for trapping the macro-particles.

  12. Extended HXR Sources - Albedo Patches or Coronal Sources

    NASA Technical Reports Server (NTRS)

    Dennis, Brian R.

    2011-01-01

    Extended HXR sources in the presence of compact footpoints have been reported based on visibility amplitudes from different detectors. Attempts have been made to determine the location and extent of these sources through direct imaging. Results of this work will be described for simulated sources and for specific flares at different solar longitudes, with a discussion of the possible nature of the extended sources as either albedo patches or coronal sources or a combination of the two.

  13. FABRICATION OF NEUTRON SOURCES

    DOEpatents

    Birden, J.H.

    1959-01-20

    A method is presented for preparing a more efficient neutron source comprising inserting in a container a quantity of Po-210, inserting B powder coated with either Ag, Pt, or Ni. The container is sealed and then slowly heated to about 450 C to volatilize the Po and effect combination of the coated powder with the Po. The neutron flux emitted by the unit is moritored and the heating step is terminated when the flux reaches a maximum or selected level.

  14. The European Spallation Source

    SciTech Connect

    Peggs, S; Eshraqi, M; Hahn, H; Jansson, A; Lindroos, M; Ponton, A; Rathsman, K; Trahern, G; Bousso, S; Calaga, R; Devanz, G; Duperrier, R D; Eguia, J; Gammino, S; Moller, S P; Oyon, C; Ruber, R.J.M.Y.; Satogata, T

    2011-03-01

    The European Spallation Source (ESS) is a 5 MW, 2.5 GeV long pulse proton linac, to be built and commissioned in Lund, Sweden. The Accelerator Design Update (ADU) project phase is under way, to be completed at the end of 2012 by the delivery of a Technical Design Report. Improvements to the 2003 ESS design will be summarised, and the latest design activities will be presented.

  15. The advanced neutron source

    SciTech Connect

    Raman, S.; Hayter, J.B.

    1990-01-01

    The Advanced Neutron Source (ANS) is a new user experimental facility planned to be operational at Oak Ridge in the late 1990's. The centerpiece of the ANS will be a steady-state research reactor of unprecedented thermal neutron flux ({phi}{sub th} {approx} 8 {times} 10{sup 19} m{sup {minus}2} {center dot}s{sup {minus}1}) accompanied by extensive and comprehensive equipment and facilities for neutron-based research.

  16. The Advanced Neutron Source

    SciTech Connect

    Hayter, J.B.

    1989-01-01

    The Advanced Neutron Source (ANS) is a new user experimental facility planned to be operational at Oak Ridge in the late 1990's. The centerpiece of the ANS will be a steady-state research reactor of unprecedented thermal neutron flux ({phi}{sub th} {approx} 9{center dot}10{sup 19} m{sup -2}{center dot}s{sup -1}) accompanied by extensive and comprehensive equipment and facilities for neutron-based research. 5 refs., 5 figs.

  17. High current ion source

    DOEpatents

    Brown, Ian G.; MacGill, Robert A.; Galvin, James E.

    1990-01-01

    An ion source utilizing a cathode and anode for producing an electric arc therebetween. The arc is sufficient to vaporize a portion of the cathode to form a plasma. The plasma leaves the generation region and expands through another regon. The density profile of the plasma may be flattened using a magnetic field formed within a vacuum chamber. Ions are extracted from the plasma to produce a high current broad on beam.

  18. Open Source Software Development

    DTIC Science & Technology

    2011-01-01

    Agency’s XMM-Newton Observatory, the Sloan Digital Sky Survey, and others. These are three highly visible astrophysics research projects whose...In scientific fields like astrophysics that critically depend on software, open source is considered an essential precondition for research to...space are made, this in turn often leads to modification, extension, and new versions of the astronomical software in use that enable astrophysical

  19. Procurement Source Selection Administration

    DTIC Science & Technology

    1987-10-09

    responsible to and will function under the supervison of the Chief, Policy and Systems Review Office, Procurement Office {AP04). 3. RESPONSIBILITY The...continuity and consistency. Their corporate knowledge means more efficient and effective source selections which lead to fewer protests and sustained...available to conduct the evaluation can have an influence on manning. Fifty people may be able to do an evaluation in six months. One hundred people may be

  20. Single-photon sources

    NASA Astrophysics Data System (ADS)

    Lounis, Brahim; Orrit, Michel

    2005-05-01

    The concept of the photon, central to Einstein's explanation of the photoelectric effect, is exactly 100 years old. Yet, while photons have been detected individually for more than 50 years, devices producing individual photons on demand have only appeared in the last few years. New concepts for single-photon sources, or 'photon guns', have originated from recent progress in the optical detection, characterization and manipulation of single quantum objects. Single emitters usually deliver photons one at a time. This so-called antibunching of emitted photons can arise from various mechanisms, but ensures that the probability of obtaining two or more photons at the same time remains negligible. We briefly recall basic concepts in quantum optics and discuss potential applications of single-photon states to optical processing of quantum information: cryptography, computing and communication. A photon gun's properties are significantly improved by coupling it to a resonant cavity mode, either in the Purcell or strong-coupling regimes. We briefly recall early production of single photons with atomic beams, and the operation principles of macroscopic parametric sources, which are used in an overwhelming majority of quantum-optical experiments. We then review the photophysical and spectroscopic properties and compare the advantages and weaknesses of various single nanometre-scale objects used as single-photon sources: atoms or ions in the gas phase and, in condensed matter, organic molecules, defect centres, semiconductor nanocrystals and heterostructures. As new generations of sources are developed, coupling to cavities and nano-fabrication techniques lead to improved characteristics, delivery rates and spectral ranges. Judging from the brisk pace of recent progress, we expect single photons to soon proceed from demonstrations to applications and to bring with them the first practical uses of quantum information.

  1. Background sources at PEP

    SciTech Connect

    Lynch, H.; Schwitters, R.F.; Toner, W.T.

    1988-01-01

    Important sources of background for PEP experiments are studied. Background particles originate from high-energy electrons and positrons which have been lost from stable orbits, ..gamma..-rays emitted by the primary beams through bremsstrahlung in the residual gas, and synchrotron radiation x-rays. The effect of these processes on the beam lifetime are calculated and estimates of background rates at the interaction region are given. Recommendations for the PEP design, aimed at minimizing background are presented. 7 figs., 4 tabs.

  2. A useful infrared source.

    PubMed

    Carlon, H R

    1966-08-01

    Reliable Inconel-sheathed cartridge heaters rated at hundreds or thousands of watts have been in use for many years. Miniature heaters have been manufactured, having axial leads, which when treated with an emissive coating meet or exceed Globar emissivities in the ir. Free-air temperatures approximating 800 degrees C have been obtained for power inputs of 10 W, while temperatures as high as 1150 degrees C are possible for short lifetimes, e.g., 10 h, at power dissipations of 24 W or more. Sources can be designed to operate from d or ac power with higher voltages and lower currents depending upon physical size limitations, resulting in simplified power supply problems. Although voltages from 12 V to 230 V are practical for larger units, the sources described below operated at 1060 degrees C from a nominal 1.07 A at 18.7 V d for apower consumption of 20 W variable continuously about this value. The small dimensions of these sources compare favorably to those of a 0.5-W electronic resistor. The present units are cylindrical, 1 cm long x 4 mm diam. The construction of smaller units is possible bt difficult under present state-of-the-art limitations.

  3. Coded source neutron imaging

    SciTech Connect

    Bingham, Philip R; Santos-Villalobos, Hector J

    2011-01-01

    Coded aperture techniques have been applied to neutron radiography to address limitations in neutron flux and resolution of neutron detectors in a system labeled coded source imaging (CSI). By coding the neutron source, a magnified imaging system is designed with small spot size aperture holes (10 and 100 m) for improved resolution beyond the detector limits and with many holes in the aperture (50% open) to account for flux losses due to the small pinhole size. An introduction to neutron radiography and coded aperture imaging is presented. A system design is developed for a CSI system with a development of equations for limitations on the system based on the coded image requirements and the neutron source characteristics of size and divergence. Simulation has been applied to the design using McStas to provide qualitative measures of performance with simulations of pinhole array objects followed by a quantitative measure through simulation of a tilted edge and calculation of the modulation transfer function (MTF) from the line spread function. MTF results for both 100um and 10um aperture hole diameters show resolutions matching the hole diameters.

  4. Capillary discharge source

    DOEpatents

    Bender, III, Howard Albert

    2003-11-25

    Debris generation from an EUV electric discharge plasma source device can be significantly reduced or essentially eliminated by encasing the electrodes with dielectric or electrically insulating material so that the electrodes are shielded from the plasma, and additionally by providing a path for the radiation to exit wherein the electrodes are not exposed to the area where the radiation is collected. The device includes: (a) a body, which is made of an electrically insulating material, that defines a capillary bore that has a proximal end and a distal end and that defines at least one radiation exit; (b) a first electrode that defines a first channel that has a first inlet end that is connected to a source of gas and a first outlet end that is in communication with the capillary bore, wherein the first electrode is positioned at the distal end of the capillary bore; (c) a second electrode that defines a second channel that has a second inlet end that is in communication with the capillary bore and an outlet end, wherein the second electrode is positioned at the proximal end of the capillary bore; and (d) a source of electric potential that is connected across the first and second electrodes, wherein radiation generated within the capillary bore is emitted through the at least one radiation exit and wherein the first electrode and second electrode are shielded from the emitted radiation.

  5. Intense neutron source

    SciTech Connect

    Walko, R.J.; Bacon, F.M.; Brainard, J.P.; O'Hagan, J.B.; Riedel, A.A.

    1983-04-01

    A ScD/sub 2/ target film 5x10/sup -5/ m thick, tested in a UHV compatible 200 keV deuterium accelerator baked to 470/sup 0/C, maintained a D-D neutron output rate of 1.0-1.2x10/sup 11//s for 80 out of 140 hours of operation. This result demonstrates that a D-T neutron generator capable of a neutron output rate of 1x10/sup 13//s and having a target lifetime suitable for cancer therapy is possible. Contrary to sputter rate data, ErD/sub 2/ target films appear to erode about twice as fast as ScD/sub 2/ films, making ErD/sub 2/ unsuitable as a target material. A low pressure ion source has been developed to replace the high pressure duopigatron. Experiments have verified that the single ring magnetic cusp ion source can deliver 200 mA of deuterium ions (approx. =60% D/sup +/) at 10-15 A of arc current with a background deuterium pressure of 0.27-0.40 Pa. This source will improve the safety of a D-T machine by reducing the tritium inventory by a factor of 6, and by utilizing the Zr-Al getter as the gas reservoir.

  6. Intense neutron source

    SciTech Connect

    Walko, R.J.; Brainard, J.P.; Riedel, A.A.; O'Hagan, J.B.; Bacon, F.M.

    1982-01-01

    A ScD/sub 2/ target film 5 x 10/sup -5/ m thick, tested in a UHV compatible 200 keV deuterium accelerator baked to 470/sup 0/C, maintained a D-D neutron output rate of 1.0-1.2x10'' /s for 80 out of 140 hours of operation. This result demonstrates that a D-T neutron generator capable of a neutron output rate of 1 x 10/sup 13//s and having a target lifetime suitable for cancer therapy is possible. Contrary to sputter rate data, ErD/sub 2/ target films appear to erode about twice as fast as ScD/sub 2/ films, making ErD/sub 2/ unsuitable as a target material. A low pressure ion source has been developed to replace the more complicated duopigatron. Experiments have verified that the single ring magnetic cusp ion source can deliver 200 mA of deuterium ions (approx. = 60% D/sup +/) at 10-15 A of arc current with a background deuterium pressure of 0.27-0.40 Pa. This source will improve the safety of a D-T machine by reducing the tritium inventory by a factor of 6, and by utilizing the Zr-Al getter as the gas reservoir.

  7. Open-Source GIS

    SciTech Connect

    Vatsavai, Raju; Burk, Thomas E; Lime, Steve

    2012-01-01

    The components making up an Open Source GIS are explained in this chapter. A map server (Sect. 30.1) can broadly be defined as a software platform for dynamically generating spatially referenced digital map products. The University of Minnesota MapServer (UMN Map Server) is one such system. Its basic features are visualization, overlay, and query. Section 30.2 names and explains many of the geospatial open source libraries, such as GDAL and OGR. The other libraries are FDO, JTS, GEOS, JCS, MetaCRS, and GPSBabel. The application examples include derived GIS-software and data format conversions. Quantum GIS, its origin and its applications explained in detail in Sect. 30.3. The features include a rich GUI, attribute tables, vector symbols, labeling, editing functions, projections, georeferencing, GPS support, analysis, and Web Map Server functionality. Future developments will address mobile applications, 3-D, and multithreading. The origins of PostgreSQL are outlined and PostGIS discussed in detail in Sect. 30.4. It extends PostgreSQL by implementing the Simple Feature standard. Section 30.5 details the most important open source licenses such as the GPL, the LGPL, the MIT License, and the BSD License, as well as the role of the Creative Commons.

  8. Improved negative ion source

    DOEpatents

    Delmore, J.E.

    1984-05-01

    A method and apparatus for providing a negative ion source accelerates electrons away from a hot filament electron emitter into a region of crossed electric and magnetic fields arranged in a magnetron configuration. During a portion of the resulting cycloidal path, the electron velocity is reduced below its initial value. The electron accelerates as it leaves the surface at a rate of only slightly less than if there were no magnetic field, thereby preventing a charge buildup at the surface of the emitter. As the electron traverses the cycloid, it is decelerated during the second, third, and fourth quadrants, then reaccelerated as it approaches the end of the fourth quadrant to regain its original velocity. The minimum velocity occurs during the fourth quadrant, and corresponds to an electron temperature of 200 to 500/sup 0/C for the electric and magnetic fields commonly encountered in the ion sources of magnetic sector mass spectrometers. An ion source using the above-described thermalized electrons is also disclosed.

  9. Coded source neutron imaging

    NASA Astrophysics Data System (ADS)

    Bingham, Philip; Santos-Villalobos, Hector; Tobin, Ken

    2011-03-01

    Coded aperture techniques have been applied to neutron radiography to address limitations in neutron flux and resolution of neutron detectors in a system labeled coded source imaging (CSI). By coding the neutron source, a magnified imaging system is designed with small spot size aperture holes (10 and 100μm) for improved resolution beyond the detector limits and with many holes in the aperture (50% open) to account for flux losses due to the small pinhole size. An introduction to neutron radiography and coded aperture imaging is presented. A system design is developed for a CSI system with a development of equations for limitations on the system based on the coded image requirements and the neutron source characteristics of size and divergence. Simulation has been applied to the design using McStas to provide qualitative measures of performance with simulations of pinhole array objects followed by a quantitative measure through simulation of a tilted edge and calculation of the modulation transfer function (MTF) from the line spread function. MTF results for both 100μm and 10μm aperture hole diameters show resolutions matching the hole diameters.

  10. EUV source collector

    NASA Astrophysics Data System (ADS)

    Böwering, Norbert R.; Ershov, Alex I.; Marx, William F.; Khodykin, Oleh V.; Hansson, Björn A. M.; Vargas L., Ernesto; Chavez, Juan A.; Fomenkov, Igor V.; Myers, David W.; Brandt, David C.

    2006-03-01

    A collector subsystem has been designed, built, and tested. The subsystem consists of a 320mm diameter ellipsoidal collector coated with a graded multilayer, mounting mechanics, thermal management capability, and a collector protection system. The EUV light emission can be collected with a solid angle of 1.6 sr. Collector substrates have been developed with the goal of offering both optical surface quality to support high multilayer mirror (MLM) reflectivity and material compatibility for long-term operation in the EUV source system. An interface-engineered MLM coating capable of maintaining high normal-incidence peak reflectivity at 13.5 nm during continuous operation at 400 °C has been developed. The thermal management of the system has been engineered and tested to maintain uniform substrate temperature during operation. Lastly, protection techniques have been developed to provide the collector with a long operational lifetime. Performance data for the entire subsystem are presented. The collector was installed in the source chamber of a laser-produced-plasma EUV source during system integration experiments using a tin droplet target. First results of the collected EUV output at the intermediate focus measured with a power meter and a fluorescence-converter-based imaging system are discussed.

  11. Negative ion source

    DOEpatents

    Delmore, James E.

    1987-01-01

    A method and apparatus for providing a negative ion source accelerates electrons away from a hot filament electron emitter into a region of crossed electric and magnetic fields arranged in a magnetron configuration. During a portion of the resulting cycloidal path, the electron velocity is reduced below its initial value. The electron accelerates as it leaves the surface at a rate of only slightly less than if there were no magnetic field, thereby preventing a charge buildup at the surface of the emitter. As the electron traverses the cycloid, it is decelerated during the second, third, and fourth quadrants, then reeccelerated as it approaches the end of the fourth quadrant to regain its original velocity. The minimum velocity occurs during the fourth quadrant, and corresponds to an electron temperature of 200.degree. to 500.degree. for the electric and magnetic fields commonly encountered in the ion sources of magnetic sector mass spectrometers. An ion source using the above-described thermalized electrons is also disclosed.

  12. API Global Sourcing Strategies 2010.

    PubMed

    Bennett, Shannon

    2010-09-01

    The API Global Sourcing Strategies 2010 Conference, held in Berlin, included topics covering new developments in the field of global sourcing of active pharmaceutical ingredients (APIs). This conference report highlights selected presentations on development in Eastern API markets, specifically India and China, factors influencing changes in global API sourcing, and risk mitigation in API sourcing.

  13. Online Sources of Competitive Intelligence.

    ERIC Educational Resources Information Center

    Wagers, Robert

    1986-01-01

    Presents an approach to using online sources of information for competitor intelligence (i.e., monitoring industry and tracking activities of competitors); identifies principal sources; and suggests some ways of making use of online databases. Types and sources of information and sources and database charts are appended. Eight references are…

  14. Source Monitoring in Alzheimer's Disease

    ERIC Educational Resources Information Center

    El Haj, Mohamad; Fasotti, Luciano; Allain, Philippe

    2012-01-01

    Source monitoring is the process of making judgments about the origin of memories. There are three categories of source monitoring: reality monitoring (discrimination between self- versus other-generated sources), external monitoring (discrimination between several external sources), and internal monitoring (discrimination between two types of…

  15. NON-POINT SOURCE POLLUTION

    EPA Science Inventory

    Non-point source pollution is a diffuse source that is difficult to measure and is highly variable due to different rain patterns and other climatic conditions. In many areas, however, non-point source pollution is the greatest source of water quality degradation. Presently, stat...

  16. Integrated Power Source Grant

    NASA Technical Reports Server (NTRS)

    2001-01-01

    Traditional spacecraft power systems incorporate a solar array energy source, an energy storage element (battery), and battery charge control and bus voltage regulation electronics to provide continuous electrical power for spacecraft systems and instruments. Dedicated power conditioning components provide limited fault isolation between systems and instruments, while a centralized power-switching unit provides spacecraft load control. Battery undervoltage conditions are detected by the spacecraft processor, which removes fault conditions and non-critical loads before permanent battery damage can occur. Cost effective operation of a micro-sat constellation requires a fault tolerant spacecraft architecture that minimizes on-orbit operational costs by permitting autonomous reconfiguration in response to unexpected fault conditions. A new micro-sat power system architecture that enhances spacecraft fault tolerance and improves power system survivability by continuously managing the battery charge and discharge processes on a cell-by-cell basis has been developed. This architecture is based on the Integrated Power Source (US patent 5644207), which integrates dual junction solar cells, Lithium Ion battery cells, and processor based charge control electronics into a structural panel that can be deployed or used to form a portion of the outer shell of a micro-spacecraft. The first generation Integrated Power Source is configured as a one inch thick panel in which prismatic Lithium Ion battery cells are arranged in a 3x7 matrix (26VDC) and a 3x1 matrix (3.7VDC) to provide the required output voltages and load currents. A multi-layer structure holds the battery cells, as well as the thermal insulators that are necessary to protect the Lithium Ion battery cells from the extreme temperatures of the solar cell layer. Independent thermal radiators, located on the back of the panel, are dedicated to the solar cell array, the electronics, and the battery cell array. In deployed

  17. Compact ion accelerator source

    DOEpatents

    Schenkel, Thomas; Persaud, Arun; Kapadia, Rehan; Javey, Ali

    2014-04-29

    An ion source includes a conductive substrate, the substrate including a plurality of conductive nanostructures with free-standing tips formed on the substrate. A conductive catalytic coating is formed on the nanostructures and substrate for dissociation of a molecular species into an atomic species, the molecular species being brought in contact with the catalytic coating. A target electrode placed apart from the substrate, the target electrode being biased relative to the substrate with a first bias voltage to ionize the atomic species in proximity to the free-standing tips and attract the ionized atomic species from the substrate in the direction of the target electrode.

  18. Stationary Source Enforcement

    EPA Pesticide Factsheets

    This document may be of assistance in applying the New Source Review (NSR) air permitting regulations including the Prevention of Significant Deterioration (PSD) requirements. This document is part of the NSR Policy and Guidance Database. Some documents in the database are a scanned or retyped version of a paper photocopy of the original. Although we have taken considerable effort to quality assure the documents, some may contain typographical errors. Contact the office that issued the document if you need a copy of the original.

  19. The European Spallation Source

    SciTech Connect

    Lindroos M.; Calaga R.; Bousson S.; Danared H.; Devanz G. et al

    2011-04-20

    In 2003 the joint European effort to design a European Spallation Source (ESS) resulted in a set of reports, and in May 2009 Lund was agreed to be the ESS site. The ESS Scandinavia office has since then worked on setting all the necessary legal and organizational matters in place so that the Design Update and construction can be started in January 2011, in collaboration with European partners. The Design Update phase is expected to end in 2012, to be followed by a construction phase, with first neutrons expected in 2018-2019.

  20. PSD Definition of Source

    EPA Pesticide Factsheets

    This document may be of assistance in applying the New Source Review (NSR) air permitting regulations including the Prevention of Significant Deterioration (PSD) requirements. This document is part of the NSR Policy and Guidance Database. Some documents in the database are a scanned or retyped version of a paper photocopy of the original. Although we have taken considerable effort to quality assure the documents, some may contain typographical errors. Contact the office that issued the document if you need a copy of the original.

  1. Leptospirosis from water sources

    PubMed Central

    Wynwood, Sarah Jane; Graham, Glenn Charles; Weier, Steven Lance; Collet, Trudi Anne; McKay, David Brian; Craig, Scott Benjamin

    2014-01-01

    Leptospirosis outbreaks have been associated with many common water events including water consumption, water sports, environmental disasters, and occupational exposure. The ability of leptospires to survive in moist environments makes them a high-risk agent for infection following contact with any contaminated water source. Water treatment processes reduce the likelihood of leptospirosis or other microbial agents causing infection provided that they do not malfunction and the distribution networks are maintained. Notably, there are many differences in water treatment systems around the world, particularly between developing and developed countries. Detection of leptospirosis in water samples is uncommonly performed by molecular methods. PMID:25348115

  2. Variable leak gas source

    DOEpatents

    Henderson, Timothy M.; Wuttke, Gilbert H.

    1977-01-01

    A variable leak gas source and a method for obtaining the same which includes filling a quantity of hollow glass micro-spheres with a gas, storing said quantity in a confined chamber having a controllable outlet, heating said chamber above room temperature, and controlling the temperature of said chamber to control the quantity of gas passing out of said controllable outlet. Individual gas filled spheres may be utilized for calibration purposes by breaking a sphere having a known quantity of a known gas to calibrate a gas detection apparatus.

  3. ESCO Corp. Source Determination

    EPA Pesticide Factsheets

    This document may be of assistance in applying the New Source Review (NSR) air permitting regulations including the Prevention of Significant Deterioration (PSD) requirements. This document is part of the NSR Policy and Guidance Database. Some documents in the database are a scanned or retyped version of a paper photocopy of the original. Although we have taken considerable effort to quality assure the documents, some may contain typographical errors. Contact the office that issued the document if you need a copy of the original.

  4. Definition of Source

    EPA Pesticide Factsheets

    This document may be of assistance in applying the New Source Review (NSR) air permitting regulations including the Prevention of Significant Deterioration (PSD) requirements. This document is part of the NSR Policy and Guidance Database. Some documents in the database are a scanned or retyped version of a paper photocopy of the original. Although we have taken considerable effort to quality assure the documents, some may contain typographical errors. Contact the office that issued the document if you need a copy of the original.

  5. Sources of tritium

    SciTech Connect

    Phillips, J.E.; Easterly, C.E.

    1980-12-01

    A review of tritium sources is presented. The tritium production and release rates are discussed for light water reactors (LWRs), heavy water reactors (HWRs), high temperature gas cooled reactors (HTGRs), liquid metal fast breeder reactors (LMFBRs), and molten salt breeder reactors (MSBRs). In addition, release rates are discussed for tritium production facilities, fuel reprocessing plants, weapons detonations, and fusion reactors. A discussion of the chemical form of the release is included. The energy producing facilities are ranked in order of increasing tritium production and release. The ranking is: HTGRs, LWRs, LMFBRs, MSBRs, and HWRs. The majority of tritium has been released in the form of tritiated water.

  6. ITRB Spar Domestic Source

    DTIC Science & Technology

    2012-12-14

    6  Figure 4 Cobham Laminate Design...fiber/resin combination was selected for final laminate design and FEA analysis. Table 2 Fiber Candidate Matrix Type E (mpsi) UTS (kpsi) Source...NA NA NA 14.5 11.46 414 5 NA NA NA NA NA 27.8* NA NA NA NA NA NA 7.2* NA NA NA 86* NA NA NA Laminate  made with 7781 glass PR520 One Epoxy 6 0 NA NA

  7. GPC Single Source Letter

    EPA Pesticide Factsheets

    This document may be of assistance in applying the New Source Review (NSR) air permitting regulations including the Prevention of Significant Deterioration (PSD) requirements. This document is part of the NSR Policy and Guidance Database. Some documents in the database are a scanned or retyped version of a paper photocopy of the original. Although we have taken considerable effort to quality assure the documents, some may contain typographical errors. Contact the office that issued the document if you need a copy of the original.

  8. Modeling Magnetospheric Sources

    NASA Technical Reports Server (NTRS)

    Walker, Raymond J.; Ashour-Abdalla, Maha; Ogino, Tatsuki; Peroomian, Vahe; Richard, Robert L.

    2001-01-01

    We have used global magnetohydrodynamic, simulations of the interaction between the solar wind and magnetosphere together with single particle trajectory calculations to investigate the sources of plasma entering the magnetosphere. In all of our calculations solar wind plasma primarily enters the magnetosphere when the field line on which it is convecting reconnects. When the interplanetary magnetic field has a northward component the reconnection is in the polar cusp region. In the simulations plasma in the low latitude boundary layer (LLBL) can be on either open or closed field lines. Open field lines occur when the high latitude reconnection occurs in only one cusp. In the MHD calculations the ionosphere does not contribute significantly to the LLBL for northward IMF. The particle trajectory calculations show that ions preferentially enter in the cusp region where they can be accelerated by non-adiabatic motion across the high latitude electric field. For southward IMF in the MHD simulations the plasma in the middle and inner magnetosphere comes from the inner (ionospheric) boundary of the simulation. Solar wind plasma on open field lines is confined to high latitudes and exits the tailward boundary of the simulation without reaching the plasma sheet. The LLBL is populated by both ionospheric and solar wind plasma. When the particle trajectories are included solar wind ions can enter the middle magnetosphere. We have used both the MHD simulations and the particle calculations to estimate source rates for the magnetosphere which are consistent with those inferred from observations.

  9. Food protein sources.

    PubMed

    Pirie, N W

    1976-07-01

    Work on food, planned by the U.M. (Use and Management) Section of the U.K. committe, was limited to sources of protein because we agreed that more problems calling for research were likely to arise in getting adequate supplies of protein than of other types of food. Deer meat can be produced on land too rough and exposed for sheep; parts of the work on their metabolism and food requirements necessitated building a mobile laboratory. The manner in which the nutritive value of maize is affected by changes in the ratios in which the component proteins are present, stimulated similar studies on barley and groundnut. There is good quality protein in coconuts and leaves but its use in human food is restricted by the presence of fibre. Methods for separating protein from fibre and other deleterious components were improved. In cooperation with scientists in India and Nigeria, the potential yield of protein-deficient foods. e.g. cassava, were 'ennobled' by growing micro-organisms on them with the addition of a cheap source of nitrogen.

  10. Inductive source induced polarization

    NASA Astrophysics Data System (ADS)

    Marchant, David; Haber, Eldad; Oldenburg, Douglas W.

    2013-02-01

    Induced polarization (IP) surveys are commonly performed to map the distribution of electrical chargeability that is a diagnostic physical property in mineral exploration and in many environmental problems. Although these surveys have been successful in the past, the galvanic sources required for traditional IP and magnetic IP (MIP) surveys prevent them from being applied in some geological settings. We develop a new methodology for processing frequency domain EM data to identify the presence of IP effects in observations of the magnetic fields arising from an inductive source. The method makes use of the asymptotic behaviour of the secondary magnetic fields at low frequency. A new quantity, referred to as the ISIP datum, is defined so that it equals zero at low frequencies for any frequency-independent (non-chargeable) conductivity distribution. Thus, any non-zero response in the ISIP data indicates the presence of chargeable material. Numerical simulations demonstrate that the method can be applied even in complicated geological situations. A 3-D inversion algorithm is developed to recover the chargeability from the ISIP data and the inversion is demonstrated on synthetic examples.

  11. Volume 3 - Area Sources and Area Source Method Abstracts

    EPA Pesticide Factsheets

    Nonpoint (area) source emission reference materials from the EIIP. Provides nonpoint source guidance on planning, emissions estimation, data collection, inventory documentation and reporting, and quality assurance/quality control.

  12. Multiple source heat pump

    DOEpatents

    Ecker, Amir L.

    1983-01-01

    A heat pump apparatus for conditioning a fluid characterized by a fluid handler and path for circulating a fluid in heat exchange relationship with a refrigerant fluid, at least three refrigerant heat exchangers, one for effecting heat exchange with the fluid, a second for effecting heat exchange with a heat exchange fluid, and a third for effecting heat exchange with ambient air; a compressor for compressing the refrigerant; at least one throttling valve connected at the inlet side of a heat exchanger in which liquid refrigerant is vaporized; a refrigerant circuit; refrigerant; a source of heat exchange fluid; heat exchange fluid circuit and pump for circulating the heat exchange fluid in heat exchange relationship with the refrigerant; and valves or switches for selecting the heat exchangers and directional flow of refrigerant therethrough for selecting a particular mode of operation. Also disclosed are a variety of embodiments, modes of operation, and schematics therefor.

  13. Perovskite photonic sources

    NASA Astrophysics Data System (ADS)

    Sutherland, Brandon R.; Sargent, Edward H.

    2016-05-01

    The field of solution-processed semiconductors has made great strides; however, it has yet to enable electrically driven lasers. To achieve this goal, improved materials are required that combine efficient (>50% quantum yield) radiative recombination under high injection, large and balanced charge-carrier mobilities in excess of 10 cm2 V-1 s-1, free-carrier densities greater than 1017 cm-3 and gain coefficients exceeding 104 cm-1. Solid-state perovskites are -- in addition to galvanizing the field of solar electricity -- showing great promise in photonic sources, and may be the answer to realizing solution-cast laser diodes. Here, we discuss the properties of perovskites that benefit light emission, review recent progress in perovskite electroluminescent diodes and optically pumped lasers, and examine the remaining challenges in achieving continuous-wave and electrically driven lasing.

  14. Arsenic pollution sources.

    PubMed

    Garelick, Hemda; Jones, Huw; Dybowska, Agnieszka; Valsami-Jones, Eugenia

    2008-01-01

    Arsenic is a widely dispersed element in the Earth's crust and exists at an average concentration of approximately 5 mg/kg. There are many possible routes of human exposure to arsenic from both natural and anthropogenic sources. Arsenic occurs as a constituent in more than 200 minerals, although it primarily exists as arsenopyrite and as a constituent in several other sulfide minerals. The introduction of arsenic into drinking water can occur as a result of its natural geological presence in local bedrock. Arsenic-containing bedrock formations of this sort are known in Bangladesh, West Bengal (India), and regions of China, and many cases of endemic contamination by arsenic with serious consequences to human health are known from these areas. Significant natural contamination of surface waters and soil can arise when arsenic-rich geothermal fluids come into contact with surface waters. When humans are implicated in causing or exacerbating arsenic pollution, the cause can almost always be traced to mining or mining-related activities. Arsenic exists in many oxidation states, with arsenic (III) and (V) being the most common forms. Similar to many metalloids, the prevalence of particular species of arsenic depends greatly on the pH and redox conditions of the matrix in which it exists. Speciation is also important in determining the toxicity of arsenic. Arsenic minerals exist in the environment principally as sulfides, oxides, and phosphates. In igneous rocks, only those of volcanic origin are implicated in high aqueous arsenic concentrations. Sedimentary rocks tend not to bear high arsenic loads, and common matrices such as sands and sandstones contain lower concentrations owing to the dominance of quartz and feldspars. Groundwater contamination by arsenic arises from sources of arsenopyrite, base metal sulfides, realgar and orpiment, arsenic-rich pyrite, and iron oxyhydroxide. Mechanisms by which arsenic is released from minerals are varied and are accounted for by

  15. An intense radiation source

    NASA Astrophysics Data System (ADS)

    Mckeown, J.; Labrie, J.-P.; Funk, L. W.

    1985-05-01

    A 10 MeV linear accelerator operating at 100% duty factor has been designed for large radiation processing applications. A beam intensity of 50 mA has the capacity to irradiate up to 1.3 MGy-Mg/h (130 Mrad-tonne/h) making it suitable for emerging applications in bulk food irradiation and waste treatment. An ability to provide high dose rate makes on-line detoxification of industrial pollutants possible. The source can compete economically with steam-based processes, such as the degradation of cellulosic materials for the production of chemicals and liquid fuels, hence new industrial applications are expected. The paper describes the main machine components, the operating characteristics and a typical application.

  16. Large area plasma source

    NASA Technical Reports Server (NTRS)

    Foster, John (Inventor); Patterson, Michael (Inventor)

    2008-01-01

    An all permanent magnet Electron Cyclotron Resonance, large diameter (e.g., 40 cm) plasma source suitable for ion/plasma processing or electric propulsion, is capable of producing uniform ion current densities at its exit plane at very low power (e.g., below 200 W), and is electrodeless to avoid sputtering or contamination issues. Microwave input power is efficiently coupled with an ionizing gas without using a dielectric microwave window and without developing a throat plasma by providing a ferromagnetic cylindrical chamber wall with a conical end narrowing to an axial entrance hole for microwaves supplied on-axis from an open-ended waveguide. Permanent magnet rings are attached inside the wall with alternating polarities against the wall. An entrance magnet ring surrounding the entrance hole has a ferromagnetic pole piece that extends into the chamber from the entrance hole to a continuing second face that extends radially across an inner pole of the entrance magnet ring.

  17. High brightness electron sources

    SciTech Connect

    Sheffield, R.L.

    1995-07-01

    High energy physics accelerators and free electron lasers put increased demands on the electron beam sources. This paper describes the present research on attaining intense bright electron beams using photoinjectors. Recent results from the experimental programs will be given. The performance advantages and difficulties presently faced by researchers will be discussed, and the following topics will be covered. Progress has been made in photocathode materials, both in lifetime and quantum efficiency. Cesium telluride has demonstrated significantly longer lifetimes than cesium antimonide at 10{sup {minus}8} torr. However, the laser system is more difficult because cesium telluride requires quadrupled YLF instead of the doubled YLF required for cesium antimonide. The difficulty in using photoinjectors is primarily the drive laser, in particular the amplitude stability. Finally, emittance measurements of photoinjector systems can be complicated by the non-thermal nature of the electron beam. An example of the difficulty in measuring beam emittance is given.

  18. Investigating Microvibration Sources Modelling

    NASA Astrophysics Data System (ADS)

    Addari, Daniele; Aglietti, Guglielmo S.; Remedia, Marcello

    2014-06-01

    One of the challenges related to microvibration is investigating the characterisation of the microvibration sources (here emphasis is given to reaction wheel assemblies) on board satellites. This usually involves series of experiments to characterise the hardware and produce representative models. Here we present a methodology that gives good estimates covering a wide frequency range and reduce the complexity of the test campaign.In addition, a practical example of coupling between a reaction wheel assembly and a structural panel where the coupled loads have been estimated using the mathematical model and compared with experimental test results (retrieved using an interface load transducer) will be presented, giving indications of the level of accuracy that can be expected from this type of analyses.

  19. PULSED ION SOURCE

    DOEpatents

    Anderson, C.E.; Ehlers, K.W.

    1958-06-17

    An ion source is described for producing very short high density pulses of ions without bcam scattering. The ions are created by an oscillating electron discharge within a magnetic field. After the ions are drawn from the ionization chamber by an accelerating electrode the ion beam is under the influence of the magnetic field for separation of the ions according to mass and, at the same time, passes between two neutralizing plntes maintained nt equal negative potentials. As the plates are formed of a material having a high ratio of secondary electrons to impinging ions, the ion bombardment of the plntes emits electrons which neutralize the frirge space-charge of the beam and tend to prevent widening of the beam cross section due to the mutual repulsion of the ions.

  20. Space qualified laser sources

    NASA Astrophysics Data System (ADS)

    Heine, Frank; Schwander, Thomas; Lange, Robert; Smutny, Berry

    2006-04-01

    Tesat-Spacecom has developed a series of fiber coupled single frequency lasers for space applications ranging from onboard metrology for space borne FTIR spectrometers to step tunable seed lasers for LIDAR applications. The cw-seed laser developed for the ESA AEOLUS Mission shows a 3* 10 -11 Allen variance from 1 sec time intervals up to 1000 sec. Q-switched lasers with stable beam pointing under space environments are another field of development. One important aspect of a space borne laser system is a reliable fiber coupled laser diode pump source around 808nm. A dedicated development concerning chip design and packaging yielded in a 5*10 6h MTTF (mean time to failure) for the broad area emitters. Qualification and performance test results for the different laser assemblies will be presented and their application in the different space programs.

  1. Infrared source test

    SciTech Connect

    Ott, L.

    1994-11-15

    The purpose of the Infrared Source Test (IRST) is to demonstrate the ability to track a ground target with an infrared sensor from an airplane. The system is being developed within the Advance Technology Program`s Theater Missile Defense/Unmanned Aerial Vehicle (UAV) section. The IRST payload consists of an Amber Radiance 1 infrared camera system, a computer, a gimbaled mirror, and a hard disk. The processor is a custom R3000 CPU board made by Risq Modular Systems, Inc. for LLNL. The board has ethernet, SCSI, parallel I/O, and serial ports, a DMA channel, a video (frame buffer) interface, and eight MBytes of main memory. The real-time operating system VxWorks has been ported to the processor. The application code is written in C on a host SUN 4 UNIX workstation. The IRST is the result of a combined effort by physicists, electrical and mechanical engineers, and computer scientists.

  2. Nitride quantum light sources

    NASA Astrophysics Data System (ADS)

    Zhu, T.; Oliver, R. A.

    2016-02-01

    Prototype nitride quantum light sources, particularly single-photon emitters, have been successfully demonstrated, despite the challenges inherent in this complex materials system. The large band offsets available between different nitride alloys have allowed device operation at easily accessible temperatures. A wide range of approaches has been explored: not only self-assembled quantum dot growth but also lithographic methods for site-controlled nanostructure formation. All these approaches face common challenges, particularly strong background signals which contaminate the single-photon stream and excessive spectral diffusion of the quantum dot emission wavelength. If these challenges can be successfully overcome, then ongoing rapid progress in the conventional III-V semiconductors provides a roadmap for future progress in the nitrides.

  3. Thulium-170 heat source

    DOEpatents

    Walter, Carl E.; Van Konynenburg, Richard; VanSant, James H.

    1992-01-01

    An isotopic heat source is formed using stacks of thin individual layers of a refractory isotopic fuel, preferably thulium oxide, alternating with layers of a low atomic weight diluent, preferably graphite. The graphite serves several functions: to act as a moderator during neutron irradiation, to minimize bremsstrahlung radiation, and to facilitate heat transfer. The fuel stacks are inserted into a heat block, which is encased in a sealed, insulated and shielded structural container. Heat pipes are inserted in the heat block and contain a working fluid. The heat pipe working fluid transfers heat from the heat block to a heat exchanger for power conversion. Single phase gas pressure controls the flow of the working fluid for maximum heat exchange and to provide passive cooling.

  4. Helping Residents Protect Water Sources

    EPA Pesticide Factsheets

    Building on the successful early engagement of the Plain Sect agricultural community, the Eastern Lancaster County Source Water Protection Collaborative is expanding its efforts to involve local residents in the work of protecting drinking water sources.

  5. Mobile Source Observation Database (MSOD)

    EPA Pesticide Factsheets

    The Mobile Source Observation Database (MSOD) is a relational database developed by the Assessment and Standards Division (ASD) of the U.S. EPA Office of Transportation and Air Quality (formerly the Office of Mobile Sources).

  6. CELESTIAL X-RAY SOURCES.

    DTIC Science & Technology

    sources, (4) the physical conditions in the pulsating x-ray source in the Crab Nebula , and (5) miscellaneous related topics. A bibliography of all work performed under the contract is given. (Author)

  7. Sensitivity of source apportionment results to mobile source profiles.

    PubMed

    Cai, Tianqi; Schauer, James J; Huang, Wei; Fang, Dongqing; Shang, Jing; Wang, Yuqin; Zhang, Yuanxun

    2016-12-01

    The sensitivity of a source apportionment model to mobile source profiles was examined to determine the impact of using non-local mobile source profiles in chemical mass balance (CMB) models. We examined the impact of USA and Chinese mobile source profiles on source apportionment results in St. Louis, Missouri, and Beijing. The results showed that the use of non-local mobile source profiles did not impact the model apportionment results for vegetative detritus and biomass burning, but other primary source contributions were influenced by the use of non-local source profiles. Secondary organic carbon (SOC) contributions estimated by the CMB models with local and non-local profiles were compared to estimate of SOC from the EC tracer method and were found to be consistent with little bias. The results also showed that it is feasible to use the USA mobile profiles in China while model results were biased by using Chinese mobile profiles in the USA. Monthly and annual average concentrations of molecular markers in the source apportionment model showed lower sensitivity to source profiles than daily measurements, which has implications to the design of source apportionment studies.

  8. Physical source realization of complex source pulsed beams

    PubMed

    Heyman; Lomakin; Kaiser

    2000-04-01

    Complex source pulsed beams (CSPB) are exact wave-packet solutions of the time-dependent wave equation that are modeled mathematically in terms of radiation from a pulsed point source located at a complex space-time coordinate. In the present paper, the physical source realization of the CSPB is explored. This is done in the framework of the acoustic field, as a concrete physical example, but a similar analysis can be applied for electromagnetic CSPB. The physical realization of the CSPB is addressed by deriving exact expressions for the acoustic source distribution in the real coordinate space that generates the CSPB, and by exploring the power and energy flux near these sources. The exact source distribution is of finite support. Special emphasis is placed on deriving simplified source functions and parametrization for the special case where the CSPB are well collimated.

  9. Low cost uniform heat source

    NASA Technical Reports Server (NTRS)

    Smith, R. B.; Prok, G. M.

    1973-01-01

    Electrically powered heat source was developed for ground simulation of isotope heat-source assembly in Brayton power system. Heat source, which operates on ordinary 110 vac power, consists of tungsten filament heating element wound onto a spirally grooved boron nitride core and inserted in a hollowed-out graphite hexahedron.

  10. Authorship Attribution of Source Code

    ERIC Educational Resources Information Center

    Tennyson, Matthew F.

    2013-01-01

    Authorship attribution of source code is the task of deciding who wrote a program, given its source code. Applications include software forensics, plagiarism detection, and determining software ownership. A number of methods for the authorship attribution of source code have been presented in the past. A review of those existing methods is…

  11. Source-space ICA for MEG source imaging

    NASA Astrophysics Data System (ADS)

    Jonmohamadi, Yaqub; Jones, Richard D.

    2016-02-01

    Objective. One of the most widely used approaches in electroencephalography/magnetoencephalography (MEG) source imaging is application of an inverse technique (such as dipole modelling or sLORETA) on the component extracted by independent component analysis (ICA) (sensor-space ICA + inverse technique). The advantage of this approach over an inverse technique alone is that it can identify and localize multiple concurrent sources. Among inverse techniques, the minimum-variance beamformers offer a high spatial resolution. However, in order to have both high spatial resolution of beamformer and be able to take on multiple concurrent sources, sensor-space ICA + beamformer is not an ideal combination. Approach. We propose source-space ICA for MEG as a powerful alternative approach which can provide the high spatial resolution of the beamformer and handle multiple concurrent sources. The concept of source-space ICA for MEG is to apply the beamformer first and then singular value decomposition + ICA. In this paper we have compared source-space ICA with sensor-space ICA both in simulation and real MEG. The simulations included two challenging scenarios of correlated/concurrent cluster sources. Main Results. Source-space ICA provided superior performance in spatial reconstruction of source maps, even though both techniques performed equally from a temporal perspective. Real MEG from two healthy subjects with visual stimuli were also used to compare performance of sensor-space ICA and source-space ICA. We have also proposed a new variant of minimum-variance beamformer called weight-normalized linearly-constrained minimum-variance with orthonormal lead-field. Significance. As sensor-space ICA-based source reconstruction is popular in EEG and MEG imaging, and given that source-space ICA has superior spatial performance, it is expected that source-space ICA will supersede its predecessor in many applications.

  12. 4X source

    SciTech Connect

    Smith, H.V. Jr.; Allison, P.; Sherman, J.D.

    1985-01-01

    Our Penning surface-plasma source (SPS) discharge chamber was enlarged 4X in two dimensions. To date, three pulsed discharge modes have been studied: two with noisy arc (greater than or equal to 20% H/sup -/ current fluctuations) and one with quiescent arc (less than or equal to 1% H/sup -/ current fluctuations). Lower arc magnetic field and higher H/sub 2/ gas flow allow switching from the noisy to the quiescent mode. The noisy modes yield up to 120 mA of 29-keV H/sup -/ beam; for 110 mA at 29 keV, the two-dimensional normalized rms emittance is 0.017 x 0.018 ..pi...cm.mrad. The quiescent mode yields 75 mA of 29-keV H/sup -/beam; for 67 mA at 24 keV, the emittance is 0.011 x 0.012 ..pi...cm.mrad.

  13. Industrial ion source technology

    NASA Technical Reports Server (NTRS)

    Kaufman, H. R.; Robinson, R. S.

    1978-01-01

    An analytical model was developed to describe the development of a coned surface texture with ion bombardment and simultaneous deposition of an impurity. A mathematical model of sputter deposition rate from a beveled target was developed in conjuction with the texturing models to provide an important input to that model. The establishment of a general procedure that will allow the treatment of manay different sputtering configurations is outlined. Calculation of cross sections for energetic binary collisions was extened to Ar, Kr.. and Xe with total cross sections for viscosity and diffusion calculated for the interaction energy range from leV to 1000eV. Physical sputtering and reactive ion etching experiments provided experimental data on the operating limits of a broad beam ion source using CF4 as a working gas to produce reactive species in a sputtering beam. Magnetic clustering effects are observed when Al is seeded with Fe and sputtered with Ar(?) ions. Silicon was textured at a micron scale by using a substrate temperature of 600 C.

  14. ECR ion source

    SciTech Connect

    Billquist, P.J.; Harkewicz, R.; Pardo, R.C.

    1995-08-01

    The feasibility of using a 30-watt pulsed NdYAG laser to ablate or evaporate material directly into the ECR had some initial exploratory runs and produced two distinctly interesting results. This technique holds the possibility of using small quantities of material, with a high efficiency, and being applicable to all solids. The laser illuminates a sample through one of the radial ports in the ECR main plasma chamber. The off-line tests indicated that our surplus (free) laser is capable of ablating significant quantities of interesting materials. The first tests of the laser ablation idea were carried out using a bismuth sample. The inherent pulsed nature of the technique allowed us to immediately study the time evolution of charge states in the ECR plasma. The results are directly comparable to model calculations and are completely consistent with the sequential stepwise stripping process which was assumed to dominate the high charge state production process. A paper describing our results will be presented at the 1995 International Ion Source Conference.

  15. The heliospheric energy source

    NASA Technical Reports Server (NTRS)

    Parker, E. N.

    1986-01-01

    The solar wind and the heliosphere exist as a consequence of the heat input to the corona, particularly the coronal holes. The necessary energy input to coronal holes has been estimated to be 10 to the 6th erg/sq cm sec, requiring Alfven waves with rms fluid velocities of 100 km/sec. Observational upper limits on coronal fluid velocities are of the order of 25 km/sec, which may not apply to the transparent coronal hole. Alternatively it has been suggested that coronal holes may be heated by agitation from neighboring active regions, suggesting that the vigor of a coronal hole depends upon its location. The Ulysses Mission will provide a direct comparison of the strength of the high speed wind from coronal holes at low latitude and coronal holes at high latitude, from which the nature of the presently unknown energy sources of the coronal holes and the resulting structure of the heliosphere may be better judged. The question is fundamental to the dynamics of the windspheres of all stars.

  16. Eradicating rabies at source.

    PubMed

    Pastoret, P-P; Van Gucht, S; Brochier, B

    2014-08-01

    Along with zoonotic influenza and antimicrobial resistance, rabies has been identified as a key One Health issue by the World Organisation for Animal Health (OIE), World Health Organization (WHO) and Food and Agriculture Organization of the United Nations (FAO). It provides an excellent example of a disease that has an impact on public, animal and environmental health, and therefore benefits from a One Health approach to management. Regrettably, this zoonotic disease is still neglected despite the fact that, annually, it kills as many as 70,000 people worldwide (chiefly children in Asia and Africa), millions of dogs suffer and die, and the disease threatens some populations of endangered wildlife. This is particularly unfortunate, given that effective means of prevention exist. As Her Royal Highness Princess Haya of Jordan pointed out in a video to mark World Rabies Day on 28 September 2013, rabies is a serious world public health problem that is all too often underestimated and even neglected. Yet we know it can be eliminated. By combatting rabies at its source in animals and vaccinating 70% of dogs, we can eradicate it.

  17. [The source of antioxidants].

    PubMed

    Guggenbühl, N

    2006-01-01

    Free radicals are thought to play an important part in the phenomenon of aging, especially as regards the eye. Antioxydants represent an interesting means of limiting the damage due to oxydation, as is shown by a number of studies. Food is an unexpected source of antioxydants, which exist in the form of thousands of different compounds. Colored fruits and vegetables are known to be rich in carotenoids, some of which such as lutein and zeaxanthin tend to accumulate at the level of the macula. But there are plenty of other foodstuffs that supply the antiradical armoury, as has been shown by analytical findings over a number of years. Legumes and whole cereals have a very high antioxydant potential. Other items, from tea to...chocolate, contribute to providing antioxydants through food. Although some specific antioxydants appear so far to be particularly interesting, the results gathered over a number of years in various fields show the advantages of combining several interacting antioxydants. A diet with a strong vegetal component, without being vegetarian, provides a very broad range of antioxydants and thus appears to be an important defense against oxidative stress.

  18. 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.

  19. Radiation sources working group summary

    SciTech Connect

    Fazio, M.V.

    1998-12-31

    The Radiation Sources Working Group addressed advanced concepts for the generation of RF energy to power advanced accelerators. The focus of the working group included advanced sources and technologies above 17 GHz. The topics discussed included RF sources above 17 GHz, pulse compression techniques to achieve extreme peak power levels, components technology, technology limitations and physical limits, and other advanced concepts. RF sources included gyroklystrons, magnicons, free-electron masers, two beam accelerators, and gyroharmonic and traveling wave devices. Technology components discussed included advanced cathodes and electron guns, high temperature superconductors for producing magnetic fields, RF breakdown physics and mitigation, and phenomena that impact source design such as fatigue in resonant structures due to RF heating. New approaches for RF source diagnostics located internal to the source were discussed for detecting plasma and beam phenomena existing in high energy density electrodynamic systems in order to help elucidate the reasons for performance limitations.

  20. Reull Vallis Source Region

    NASA Technical Reports Server (NTRS)

    2002-01-01

    [figure removed for brevity, see original site] (Released 1 July 2002) The jumbled, chaotic terrain in this THEMIS image may represent a source region for the Reull Vallis, one of the larger channel systems in the southern hemisphere of Mars. Such regions of chaos are thought to form by the catastrophic release of groundwater. If this was the case, then the water would have flowed down gradient to the south and may have contributed to the formation of the Reull Vallis. The top of the image shows two short segments of channels that are interrupted by the chaos, demonstrating that there was a channel system in place before the ground foundered to produce the chaos. One of the more intriguing features seen among the jumbled blocks are narrow ledges that vaguely resemble bath tub rings in the way they conform to the topography. Two good examples are seen running roughly left-right across the image about a fourth of the way down. At first they appear to be layers protruding from the cliff faces, but upon closer inspection a more ledge-like character is evident. Note how they appear different between the south-facing and north facing cliffs. The occurrence of one of these features on the south-facing interior rim of the largest crater in the image but nowhere else around the rim argues against the idea that the ledges are due to a layer of rock cropping out throughout the landscape. Instead, they appear more like the edges of a layer of sediment that drapes the topography. It is possible that the sediment is mixed with ice and is best preserved in the shadowed portions of the terrain. There is no easy explanation for these unusual features. They represent one more Martian enigma.

  1. Design calculations for the ANS (Advanced Neutron Source) cold source

    SciTech Connect

    Lillie, R.A.; Alsmiller, R.G. Jr.

    1988-01-01

    The calculation procedure, based on discrete ordinates transport methods, that is being used to carry out design calculations for the Advanced Neutron Source cold source is described. Calculated results on the gain in cold neutron flux produced by a liquid deuterium cold source are compared with experimental data and with calculated data previously obtained by P. Ageron et al., at the Institute Max von Laue-Paul Langevin in Grenoble, France. Calculated results are also presented that indicated how the flux of cold neutrons vary with cold source parameters. 23 refs., 5 figs., 3 tabs.

  2. Retrospective source attribution for source-oriented sampling

    NASA Astrophysics Data System (ADS)

    Bein, K. J.; Zhao, Y.; Wexler, A. S.

    2015-10-01

    Previous work successfully implemented a novel system that uses a single particle mass spectrometer to conditionally sample size-segregated, source-oriented particles from the ambient atmosphere in real-time. The underlying hypothesis is that the composition of individual particles is a metric of particle source and thus sampling particles based on composition should be synonymous with sampling based on source. System operation relies on real-time pattern recognition to control the actuation of different ChemVol samplers, where each ChemVol is associated with a unique composition signature. In the current work, a synthesis of data collected during these studies is used in retrospect to reconcile the actual source combinations contributing to the particles collected by each ChemVol. Source attribution is based on correlations between ChemVol sampling periods and coincident wind direction and temporal emissions patterns, coupled to knowledge of single particle composition and surrounding sources. Residential and commercial cooking, vehicular emissions, residential heating and highly processed regional background PM were identified as the major sources. Results show that real-time patterns in single particle mixing state correctly identified specific sources and that these sources were successfully separated into different ChemVols for both summer and winter seasons.

  3. Disintegrins from Hematophagous Sources

    PubMed Central

    Assumpcao, Teresa C. F.; Ribeiro, José M. C.; Francischetti, Ivo M. B.

    2012-01-01

    Bloodsucking arthropods are a rich source of salivary molecules (sialogenins) which inhibit platelet aggregation, neutrophil function and angiogenesis. Here we review the literature on salivary disintegrins and their targets. Disintegrins were first discovered in snake venoms, and were instrumental in our understanding of integrin function and also for the development of anti-thrombotic drugs. In hematophagous animals, most disintegrins described so far have been discovered in the salivary gland of ticks and leeches. A limited number have also been found in hookworms and horseflies, and none identified in mosquitoes or sand flies. The vast majority of salivary disintegrins reported display a RGD motif and were described as platelet aggregation inhibitors, and few others as negative modulator of neutrophil or endothelial cell functions. This notably low number of reported disintegrins is certainly an underestimation of the actual complexity of this family of proteins in hematophagous secretions. Therefore an algorithm was created in order to identify the tripeptide motifs RGD, KGD, VGD, MLD, KTS, RTS, WGD, or RED (flanked by cysteines) in sialogenins deposited in GenBank database. The search included sequences from various blood-sucking animals such as ticks (e.g., Ixodes sp., Argas sp., Rhipicephalus sp., Amblyommasp.), tabanids (e.g., Tabanus sp.), bugs (e.g., Triatoma sp., Rhodnius prolixus), mosquitoes (e.g., Anopheles sp., Aedes sp., Culex sp.), sand flies (e.g., Lutzomyia sp., Phlebotomus sp.), leeches (e.g., Macrobdella sp., Placobdella sp.) and worms (e.g., Ancylostoma sp.). This approach allowed the identification of a remarkably high number of novel putative sialogenins with tripeptide motifs typical of disintegrins (>450 sequences) whose biological activity remains to be verified. This database is accessible online as a hyperlinked worksheet and displays biochemical, taxonomic, and gene ontology aspects for each putative disintegrin. It is also freely

  4. Constricted glow discharge plasma source

    DOEpatents

    Anders, Andre; Anders, Simone; Dickinson, Michael; Rubin, Michael; Newman, Nathan

    2000-01-01

    A constricted glow discharge chamber and method are disclosed. The polarity and geometry of the constricted glow discharge plasma source is set so that the contamination and energy of the ions discharged from the source are minimized. The several sources can be mounted in parallel and in series to provide a sustained ultra low source of ions in a plasma with contamination below practical detection limits. The source is suitable for applying films of nitrides such as gallium nitride and oxides such as tungsten oxide and for enriching other substances in material surfaces such as oxygen and water vapor, which are difficult process as plasma in any known devices and methods. The source can also be used to assist the deposition of films such as metal films by providing low-energy ions such as argon ions.

  5. Today's ground source heat pumps

    SciTech Connect

    Bose, J.E.

    1993-01-01

    Ground source heat pumps are one of the nation's fastest growing businesses in terms of increased sales of equipment as reported by water source heat pump manufacturers. The success can be attributed in part to these heat pump's reputation as a cost saving system and more recently as an environmentally sound concept. Engineers having an interest in ground source technology come from a large and diverse audience consisting of those who have heard about ground source systems and are contemplating entering the business and those who are experienced and looking to broaden their application base. This article discusses the water source heat pump and its benefits, the commercial Water Loop Heat Pump (WLHP), the ground source heat pump, the commercial Closed Loop/Ground Coupled WLHP, designing a ground heat exchanger, information available for design, and successful systems.

  6. Tunable High Brightness Semiconductor Sources

    DTIC Science & Technology

    2015-05-01

    AFRL-RY-WP-TR-2015-0066 TUNABLE HIGH BRIGHTNESS SEMICONDUCTOR SOURCES Robert Bedford, Saima Husaini, Charles Reyner, and Tuoc Dang...3. DATES COVERED (From - To) May 2015 Final 5 November 2010 – 1 February 2015 4. TITLE AND SUBTITLE TUNABLE HIGH BRIGHTNESS SEMICONDUCTOR SOURCES 5a...included within the Tunable High Brightness Semiconductor Sources work unit includes several technology advancements. First, theoretical advances in mid

  7. Source-circuit design overview

    NASA Technical Reports Server (NTRS)

    Ross, R. G., Jr.

    1983-01-01

    The source circuit is the fundamental electrical building block of a large central-station array; it consists of a series-parallel network of solar cells that develops full system voltage. The array field is generally made up of a large number of parallel source circuits. Source-circuit electrical configuration is driven by a number of design considerations, which must be considered simultaneously. Array fault tolerance and hot spot heating endurance are examined in detail.

  8. Positron sources for Linear Colliders

    SciTech Connect

    Gai Wei; Liu Wanming

    2009-09-02

    Positron beams have many applications and there are many different concepts for positron sources. In this paper, only positron source techniques for linear colliders are covered. In order to achieve high luminosity, a linear collider positron source should have a high beam current, high beam energy, small emittance and, for some applications, a high degree of beam polarization. There are several different schemes presently being developed around the globe. Both the differences between these schemes and their common technical challenges are discussed.

  9. ACCELERATOR BASED CONTINUOUS NEUTRON SOURCE.

    SciTech Connect

    SHAPIRO,S.M.; RUGGIERO,A.G.; LUDEWIG,H.

    2003-03-25

    Until the last decade, most neutron experiments have been performed at steady-state, reactor-based sources. Recently, however, pulsed spallation sources have been shown to be very useful in a wide range of neutron studies. A major review of neutron sources in the US was conducted by a committee chaired by Nobel laureate Prof. W. Kohn: ''Neutron Sources for America's Future-BESAC Panel on Neutron Sources 1/93''. This distinguished panel concluded that steady state and pulsed sources are complementary and that the nation has need for both to maintain a balanced neutron research program. The report recommended that both a new reactor and a spallation source be built. This complementarity is recognized worldwide. The conclusion of this report is that a new continuous neutron source is needed for the second decade of the 20 year plan to replace aging US research reactors and close the US neutron gap. it is based on spallation production of neutrons using a high power continuous superconducting linac to generate protons impinging on a heavy metal target. There do not appear to be any major technical challenges to the building of such a facility since a continuous spallation source has been operating in Switzerland for several years.

  10. Animal models of source memory.

    PubMed

    Crystal, Jonathon D

    2016-01-01

    Source memory is the aspect of episodic memory that encodes the origin (i.e., source) of information acquired in the past. Episodic memory (i.e., our memories for unique personal past events) typically involves source memory because those memories focus on the origin of previous events. Source memory is at work when, for example, someone tells a favorite joke to a person while avoiding retelling the joke to the friend who originally shared the joke. Importantly, source memory permits differentiation of one episodic memory from another because source memory includes features that were present when the different memories were formed. This article reviews recent efforts to develop an animal model of source memory using rats. Experiments are reviewed which suggest that source memory is dissociated from other forms of memory. The review highlights strengths and weaknesses of a number of animal models of episodic memory. Animal models of source memory may be used to probe the biological bases of memory. Moreover, these models can be combined with genetic models of Alzheimer's disease to evaluate pharmacotherapies that ultimately have the potential to improve memory.

  11. Neutron imaging of radioactive sources

    NASA Astrophysics Data System (ADS)

    Hameed, F.; Karimzadeh, S.; Zawisky, M.

    2008-08-01

    Isotopic neutron sources have been available for more than six decades. At the Atomic Institute in Vienna, operating a 250 kW TRIGA reactor, different neutron sources are in use for instrument calibration and fast neutron applications but we have only little information about their construction and densities. The knowledge of source design is essential for a complete MCNP5 modeling of the experiments. Neutron radiography (NR) and neutron tomography (NT) are the best choices for the non-destructive inspection of the source geometry and homogeneity. From the transmission analysis we gain information about the shielding components and the densities of the radio-isotopes in the cores. Three neutron sources, based on (alpha, n) reaction, have been investigated, two 239PuBe sources and one 241AmBe source. In the NR images the internal structure was clearly revealed using high-resolving scintillation and imaging plate detectors. In one source tablet a crack was detected which causes asymmetric neutron emission. The tomography inspection of strong absorbing materials is more challenging due to the low beam intensity of 1.3x105 n/cm2s at our NT instrument, and due to the beam hardening effect which requires an extension of reconstruction software. The tomographic inspection of a PuBe neutron source and appropriate measures for background and beam hardening correction are presented.

  12. ION SOURCE UNIT FOR CALUTRON

    DOEpatents

    Sloan, D.H.; Yockey, H.P.; Schmidt, F.H.

    1959-04-14

    An improvement in the mounting arrangement for an ion source within the vacuum tank of a calutron device is reported. The cathode and arc block of the source are independently supported from a stem passing through the tank wall. The arc block may be pivoted and moved longitudinally with respect to the stem to thereby align the arc chamber in the biock with the cathode and magnetic field in the tank. With this arrangement the elements of the ion source are capable of precise adjustment with respect to one another, promoting increased source efficiency.

  13. SOURCE PARTITIONING USING STABLE ISOTOPES: COPING WITH TOO MANY SOURCES

    EPA Science Inventory

    Stable isotopes are increasingly being used as tracers in environmental studies. One application is to use isotopic ratios to quantitatively determine the proportional contribution of several sources to a mixture, such as the proportion of various pollution sources in a waste st...

  14. A NAIVE BAYES SOURCE CLASSIFIER FOR X-RAY SOURCES

    SciTech Connect

    Broos, Patrick S.; Getman, Konstantin V.; Townsley, Leisa K.; Feigelson, Eric D.; Garmire, Gordon P.; Povich, Matthew S.

    2011-05-01

    The Chandra Carina Complex Project (CCCP) provides a sensitive X-ray survey of a nearby starburst region over >1 deg{sup 2} in extent. Thousands of faint X-ray sources are found, many concentrated into rich young stellar clusters. However, significant contamination from unrelated Galactic and extragalactic sources is present in the X-ray catalog. We describe the use of a naive Bayes classifier to assign membership probabilities to individual sources, based on source location, X-ray properties, and visual/infrared properties. For the particular membership decision rule adopted, 75% of CCCP sources are classified as members, 11% are classified as contaminants, and 14% remain unclassified. The resulting sample of stars likely to be Carina members is used in several other studies, which appear in this special issue devoted to the CCCP.

  15. Hollow electrode plasma excitation source

    DOEpatents

    Ballou, Nathan E.

    1992-01-01

    A plasma source incorporates a furnace as a hollow anode, while a coaxial cathode is disposed therewithin. The source is located in a housing provided with an ionizable gas such that a glow discharge is produced between anode and cathode. Radiation or ionic emission from the glow discharge characterizes a sample placed within the furnace and heated to elevated temperatures.

  16. The Linac Coherent Light Source

    DOE PAGES

    White, William E.; Robert, Aymeric; Dunne, Mike

    2015-05-01

    The Linac Coherent Light Source (LCLS) at the SLAC National Accelerator Laboratory was the first hard X-ray free-electron laser (FEL) to operate as a user facility. After five years of operation, LCLS is now a mature FEL user facility. Our personal views about opportunities and challenges inherent to these unique light sources are discussed.

  17. Cretaceous source rocks in Pakistan

    SciTech Connect

    Kari, I.B. )

    1993-02-01

    Pakistan is located at the converging boundaries of the Indian, Arabian, and Eurasian plates. Evolution of this tectonic setting has provided an array of environmental habitats for deposition of petroleum source rocks and development of structural forms. The potential Cretaceous source rocks in Central and South Indus Basin are spread over an area of about 300,000 km[sup 2]. With 2% cutoff on Total Organic Carbon, the average source rock thickness is 30-50 m, which is estimated to have generated more than 200 billion bbl of oil equivalent. To date, production of more than 30,000 bbl of oil and about 1200 million ft[sup 3] of gas per day can be directly attributed to Cretaceous source. This basin was an area of extensional tectonics during the Lower to Middle Cretaceous associated with slightly restricted circulation of the sea waters at the north-western margin of Indian Plate. Lower Cretaceous source rocks (Sembar Formation) were deposited while the basin was opening up and anoxia was prevailing. Similarly Middle to Upper Cretaceous clastics were deposited in setting favorable for preservation of organic matter. The time and depth of burial of the Cretaceous source material and optimum thermal regime have provided the requisite maturation level for generation of hydrocarbons in the basin. Central Indus basin is characterized by Cretaceous source rocks mature for gas generation. However, in South Indus Basin Cretaceous source rocks lie within the oil window in some parts and have gone past it in others.

  18. The Linac Coherent Light Source

    PubMed Central

    White, William E.; Robert, Aymeric; Dunne, Mike

    2015-01-01

    The Linac Coherent Light Source (LCLS) at the SLAC National Accelerator Laboratory was the first hard X-ray free-electron laser (FEL) to operate as a user facility. After five years of operation, LCLS is now a mature FEL user facility. Our personal views about opportunities and challenges inherent to these unique light sources are discussed. PMID:25931055

  19. 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.

  20. 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

  1. School Principals' Sources of Knowledge

    ERIC Educational Resources Information Center

    Perkins, Arland Early

    2014-01-01

    The purpose of this study was to determine what sources of professional knowledge are available to principals in 1 rural East Tennessee school district. Qualitative research methods were applied to gain an understanding of what sources of knowledge are used by school principals in 1 rural East Tennessee school district and the barriers they face…

  2. Slotted antenna waveguide plasma source

    NASA Technical Reports Server (NTRS)

    Foster, John (Inventor)

    2007-01-01

    A high density plasma generated by microwave injection using a windowless electrodeless rectangular slotted antenna waveguide plasma source has been demonstrated. Plasma probe measurements indicate that the source could be applicable for low power ion thruster applications, ion implantation, and related applications. This slotted antenna plasma source invention operates on the principle of electron cyclotron resonance (ECR). It employs no window and it is completely electrodeless and therefore its operation lifetime is long, being limited only by either the microwave generator itself or charged particle extraction grids if used. The high density plasma source can also be used to extract an electron beam that can be used as a plasma cathode neutralizer for ion source beam neutralization applications.

  3. Testing Earthquake Source Inversion Methodologies

    NASA Astrophysics Data System (ADS)

    Page, Morgan; Mai, P. Martin; Schorlemmer, Danijel

    2011-03-01

    Source Inversion Validation Workshop; Palm Springs, California, 11-12 September 2010; Nowadays earthquake source inversions are routinely performed after large earthquakes and represent a key connection between recorded seismic and geodetic data and the complex rupture process at depth. The resulting earthquake source models quantify the spatiotemporal evolution of ruptures. They are also used to provide a rapid assessment of the severity of an earthquake and to estimate losses. However, because of uncertainties in the data, assumed fault geometry and velocity structure, and chosen rupture parameterization, it is not clear which features of these source models are robust. Improved understanding of the uncertainty and reliability of earthquake source inversions will allow the scientific community to use the robust features of kinematic inversions to more thoroughly investigate the complexity of the rupture process and to better constrain other earthquake-related computations, such as ground motion simulations and static stress change calculations.

  4. Optical power source control system

    NASA Astrophysics Data System (ADS)

    Husbands, C. R.

    1984-05-01

    An optical power source control system having a four port optical coupler, an optical receiver and associated comparator circuits operably connected to the optical transmission line connecting the source to an output connector. When the output connector is mated with another connector, the receiver senses the optical energy reflected from the glass/air and air/glass interfaces of the connectors and provides an appropriate signal. This signal is sufficiently high when compared to a threshold voltage level to permit the power source to operate. When the output connector is in the unmated condition the reflected optical power from the air/glass interface is no longer present and therefore the signal from the receiver falls below the threshold voltage level. With this reduced signal level, power flow to the optical source is removed or reduced thereby controlling the operation of the optical power source.

  5. Testing earthquake source inversion methodologies

    USGS Publications Warehouse

    Page, M.; Mai, P.M.; Schorlemmer, D.

    2011-01-01

    Source Inversion Validation Workshop; Palm Springs, California, 11-12 September 2010; Nowadays earthquake source inversions are routinely performed after large earthquakes and represent a key connection between recorded seismic and geodetic data and the complex rupture process at depth. The resulting earthquake source models quantify the spatiotemporal evolution of ruptures. They are also used to provide a rapid assessment of the severity of an earthquake and to estimate losses. However, because of uncertainties in the data, assumed fault geometry and velocity structure, and chosen rupture parameterization, it is not clear which features of these source models are robust. Improved understanding of the uncertainty and reliability of earthquake source inversions will allow the scientific community to use the robust features of kinematic inversions to more thoroughly investigate the complexity of the rupture process and to better constrain other earthquakerelated computations, such as ground motion simulations and static stress change calculations.

  6. Sealed source peer review plan

    SciTech Connect

    Feldman, Alexander; Leonard, Lee; Burns, Ron

    2009-01-01

    Sealed sources are known quantities of radioactive materials that have been encapsulated in quantities that produce known radiation fields. Sealed sources have multiple uses ranging from instrument calibration sources to sources that produce radiation fields for experimental applications. The Off-Site Source Recovery (OSR) Project at Los Alamos National Laboratory (LANL), created in 1999, under the direction of the Waste Management Division of the U.S. Department of Energy (DOE) Albuquerque has been assigned the responsibility to recover and manage excess and unwanted radioactive sealed sources from the public and private sector. LANL intends to ship drums containing qualified sealed sources to the Waste Isolation Pilot Plant (WIPP) for disposal. Prior to shipping, these drums must be characterized with respect to radiological content and other parameters. The U. S. Environmental Protection Agency (EPA) requires that ten radionulcides be quantified and reported for every container of waste to be disposed in the WIPP. The methods traditionally approved by the EPA include non-destructive assay (NDA) in accordance with Appendix A of the Contact-Handled Transuranic Waste Acceptance Criteria for the Waste Isolation Pilot Plant (DOE, 2002) (CH WAC). However, because of the nature and pedigree of historical records for sealed sources and the technical infeasibility of performing NDA on these sources, LANL proposes to characterize the content of these waste drums using qualified existing radiological data in lieu of direct measurement. This plan describes the process and documentation requirements for the use of the peer review process to qualify existing data for sealed radiological sources in lieu of perfonning radioassay. The peer review process will be performed in accordance with criteria provided in 40 CFR {section} 194.22 which specifies the use of the NUREG 1297 guidelines. The plan defines the management approach, resources, schedule, and technical requirements

  7. CADDIS Volume 2. Sources, Stressors and Responses: Urbanization - Energy Sources

    EPA Pesticide Factsheets

    Introduction to changes in basal energy sources with urbanization, overview of terrestrial leaf litter dynamics in urban streams, overview of how urbanization can affect primary production, respiration, and dissolved organic carbon quantity and quality.

  8. Source and Propagation Characteristics of Explosive and Other Seismic Sources

    SciTech Connect

    Ni, X; Chan, W; Wagner, R; Walter, W R; Matzel, E M

    2005-07-14

    Understanding of the source and propagation characteristics of seismic events of different types including earthquakes, explosions and mining-induced events is essential for successful discrimination of nuclear explosions. We are compiling a data set of mining related seismic events in east Eurasia. Natural earthquake data in the same region are also collected for comparison study between mining related events and earthquakes. The ground-truth data set will provide a unique and valuable resource for monitoring research. We will utilize the data set to investigate the source and propagation characteristics of seismic sources of different types including mine blasts, tremors, collapses and earthquakes. We will use various seismological techniques including spectral analysis, and waveform modeling to conduct the investigation. The research will improve our understanding of the S-wave excitation and propagation characteristics of chemical explosions and other source types.

  9. Reversal ion source - A new source of negative ion beams

    NASA Technical Reports Server (NTRS)

    Orient, O. J.; Chutjian, A.; Alajajian, S. H.

    1985-01-01

    A new type of ion source utilizing beams of electrons and target molecules, rather than a diffuse, volume plasma, is described. The source utilizes an electrostatic electron 'mirror' which reverses trajectories in an electron beam, producing electrons at their turning point having a distribution of velocities centered at zero velocity. A gas which attaches zero-velocity electrons is introduced at this turning point. Negative ions are produced by an attachment or dissociative attachment process. For many of the thermal electron-attaching molecules the cross sections can be quite large, varying as the inverse square root of the electron energy or just the s-wave threshold law. The efficiency and current density of the ion source for production of Cl(-) through the large, thermal energy attachment process is estimated. It is argued that the source can be used for the production of negative ions through attachment resonances located at higher energies as well.

  10. International Data on Radiological Sources

    SciTech Connect

    Martha Finck; Margaret Goldberg

    2010-07-01

    ABSTRACT The mission of radiological dispersal device (RDD) nuclear forensics is to identify the provenance of nuclear and radiological materials used in RDDs and to aid law enforcement in tracking nuclear materials and routes. The application of databases to radiological forensics is to match RDD source material to a source model in the database, provide guidance regarding a possible second device, and aid the FBI by providing a short list of manufacturers and distributors, and ultimately to the last legal owner of the source. The Argonne/Idaho National Laboratory RDD attribution database is a powerful technical tool in radiological forensics. The database (1267 unique vendors) includes all sealed sources and a device registered in the U.S., is complemented by data from the IAEA Catalogue, and is supported by rigorous in-lab characterization of selected sealed sources regarding physical form, radiochemical composition, and age-dating profiles. Close working relationships with global partners in the commercial sealed sources industry provide invaluable technical information and expertise in the development of signature profiles. These profiles are critical to the down-selection of potential candidates in either pre- or post- event RDD attribution. The down-selection process includes a match between an interdicted (or detonated) source and a model in the database linked to one or more manufacturers and distributors.

  11. Chromium-51 calibrating neutrino source

    SciTech Connect

    Demchenko, N.F.; Karasev, V.I.; Karelin, E.A.

    1993-12-31

    The problem for measurement of the sun neutrino flux is resolved at the specially made Baksansk neutrino telescope and calls for calibration of registration system. For this a man made neutrino source is required with the known yield of particles and intensity comparable with the intensity of the measured subject. The most suitable radionuclide for production of this source is chromium-51 the radionuclide decay of which is accompanied with neutrino radiation. At the Research Institute of Atomic Reactors (in Dimitrovgrad) the production technology is developed as well as the closed chromium-51 neutrino source is made of 4 x 10{sup 5} Ci activity. The parts of active source made in the form of core of metallic isotope-enriched chromium were irradiated in the high flux neutron trap of the SM-2 reactor. The sources were subsequently assembled at the shield cells with remote equipment application. The source was certificated as a special form radioactive material. Due to low half-life of chromium-51 (T 1/2 - 27 hours) all the operations on assembly, certification and delivery of source to the Baksansk Laboratory were performed at the earliest possible date (less than 3 days).

  12. Major sources of benzene exposure.

    PubMed Central

    Wallace, L A

    1989-01-01

    Data from EPA's TEAM Study allow us to identify the major sources of exposure to benzene for much of the U.S. population. These sources turn out to be quite different from what had previously been considered the important sources. The most important source of exposure for 50 million smokers is the mainstream smoke from their cigarettes, which accounts for about half of the total population burden of exposure to benzene. Another 20% of nationwide exposure is contributed by various personal activities, such as driving and using attached garages. (Emissions from consumer products, building materials, paints, and adhesives may also be important, although data are largely lacking.) The traditional sources of atmospheric emissions (auto exhaust and industrial emissions) account for only about 20% of total exposure. Environmental tobacco smoke is an important source, accounting for about 5% of total nationwide exposure. A number of sources sometimes considered important, such as petroleum refining operations, petrochemical manufacturing, oil storage tanks, urban-industrial areas, service stations, certain foods, groundwater contamination, and underground gasoline leaks, appear to be unimportant on a nationwide basis. PMID:2477239

  13. Diversity employment and recruitment sources

    SciTech Connect

    Not Available

    1994-08-01

    Effective human resources management has been identified as one of four critical success factors in the Department of Energy Strategic Plan. The Plan states relative to this factor: ``The Department seeks greater alignment of resources with agency priorities and increased diversification of the workforce, including gender, ethnicity, age, and skills. This diversification will bring new thinking and perspectives that heretofore have not had a voice in departmental decision-making.`` This Guide has been developed as a key tool to assist Department of Energy management and administrative staff in achieving Goal 2 of this critical success factor, which is to ``Ensure a diverse and talented workforce.`` There are numerous sources from which to recruit minorities, women and persons with disabilities. Applying creativity and proactive effort, using traditional and non-traditional approaches, and reaching out to various professional, academic and social communities will increase the reservoir of qualified candidates from which to make selections. In addition, outreach initiatives will undoubtedly yield further benefits such as a richer cultural understanding and diversity awareness. The resource listings presented in this Guide are offered to encourage active participation in the diversity recruitment process. This Guide contains resource listings by state for organizations in the following categories: (1) African American Recruitment Sources; (2) Asian American/Pacific Islander Recruitment Sources; (3) Hispanic Recruitment Sources; (4) Native American/Alaskan Native Recruitment Sources; (5) Persons with Disabilities Recruitment Sources; and (6) Women Recruitment Sources.

  14. Source rock potential in Pakistan

    SciTech Connect

    Raza, H.A. )

    1991-03-01

    Pakistan contains two sedimentary basins: Indus in the east and Balochistan in the west. The Indus basin has received sediments from precambrian until Recent, albeit with breaks. It has been producing hydrocarbons since 1914 from three main producing regions, namely, the Potwar, Sulaisman, and Kirthar. In the Potwar, oil has been discovered in Cambrian, Permian, Jurassic, and Tertiary rocks. Potential source rocks are identified in Infra-Cambrian, Permian, Paleocene, and Eocene successions, but Paleocene/Eocene Patala Formation seems to be the main source of most of the oil. In the Sulaiman, gas has been found in Cretaceous and Tertiary; condensate in Cretaceous rocks. Potential source rocks are indicated in Cretaceous, Paleocene, and Eocene successions. The Sembar Formation of Early Cretaceous age appears to be the source of gas. In the Kirthar, oil and gas have been discovered in Cretaceous and gas has been discovered in paleocene and Eocene rocks. Potential source rocks are identified in Kirthar and Ghazij formations of Eocene age in the western part. However, in the easter oil- and gas-producing Badin platform area, Union Texas has recognized the Sembar Formation of Early Cretaceous age as the only source of Cretaceous oil and gas. The Balochistan basin is part of an Early Tertiary arc-trench system. The basin is inadequately explored, and there is no oil or gas discovery so far. However, potential source rocks have been identified in Eocene, Oligocene, Miocene, and Pliocene successions based on geochemical analysis of surface samples. Mud volcanoes are present.

  15. An Accountable Source-to-Source Transformation System.

    DTIC Science & Technology

    1981-06-01

    source transformation system may be analyzed by the pro- grimmer in order to determine what optimizations were performcd. lie is therefore able to un...conceptually operate on tie text of a high-level language source program, internally they typically manipulate a non-textual repre- sentation. similar to (or...from decision number two. Which leads us to the subject of information hiding. 3.1. Information Hiding Information hiding is the separation of data

  16. Spallation neutron source and other high intensity froton sources

    SciTech Connect

    Weiren Chou

    2003-02-06

    This lecture is an introduction to the design of a spallation neutron source and other high intensity proton sources. It discusses two different approaches: linac-based and synchrotron-based. The requirements and design concepts of each approach are presented. The advantages and disadvantages are compared. A brief review of existing machines and those under construction and proposed is also given. An R&D program is included in an appendix.

  17. Three chamber negative ion source

    DOEpatents

    Leung, K.N.; Ehlers, K.W.; Hiskes, J.R.

    1983-11-10

    It is an object of this invention provide a negative ion source which efficiently provides a large flux of negatively ionized particles. This invention provides a volume source of negative ions which has a current density sufficient for magnetic fusion applications and has electrons suppressed from the output. It is still another object of this invention to provide a volume source of negative ions which can be electrostatically accelerated to high energies and subsequently neutralized to form a high energy neutral beam for use with a magnetically confined plasma.

  18. Intense source of slow positrons

    NASA Astrophysics Data System (ADS)

    Perez, P.; Rosowsky, A.

    2004-10-01

    We describe a novel design for an intense source of slow positrons based on pair production with a beam of electrons from a 10 MeV accelerator hitting a thin target at a low incidence angle. The positrons are collected with a set of coils adapted to the large production angle. The collection system is designed to inject the positrons into a Greaves-Surko trap (Phys. Rev. A 46 (1992) 5696). Such a source could be the basis for a series of experiments in fundamental and applied research and would also be a prototype source for industrial applications, which concern the field of defect characterization in the nanometer scale.

  19. 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.

  20. Nonpoint Source Tribal: Award Projects

    EPA Pesticide Factsheets

    Tribal CWA section 319 funding is awarded via base grants and competitive grants. To learn about current nonpoint source funded work in Indian Country, see the project summary descriptions of recent competitive grant awardees.

  1. Cataclysmic Variables as Synchrotron Sources?

    SciTech Connect

    Harrison, Thomas E.

    2008-05-23

    Evidence is mounting that cataclysmic variables are weak sources of synchrotron emission. If true, it demonstrates that accretion powered interacting binaries produce such emission whether their primaries are white dwarfs, neutron stars, or black holes.

  2. Electrolyte salts for power sources

    DOEpatents

    Doddapaneni, N.; Ingersoll, D.

    1995-11-28

    Electrolyte salts are disclosed for power sources comprising salts of phenyl polysulfonic acids and phenyl polyphosphonic acids. The preferred salts are alkali and alkaline earth metal salts, most preferably lithium salts. 2 figs.

  3. Electrolyte salts for power sources

    DOEpatents

    Doddapaneni, Narayan; Ingersoll, David

    1995-01-01

    Electrolyte salts for power sources comprising salts of phenyl polysulfonic acids and phenyl polyphosphonic acids. The preferred salts are alkali and alkaline earth metal salts, most preferably lithium salts.

  4. Synchrotron light source data book

    SciTech Connect

    Murphy, J.

    1989-01-01

    The ''Synchrotron Light Source Data Book'' is as its name implies a collection of data on existing and planned synchrotron light sources. The intention was to provide a compendium of tools for the design of electron storage rings as synchrotron radiation sources. The slant is toward the accelerator physicist as other booklets such as the X-ray Data Booklet, edited by D. Vaughan (LBL PUB-490), address the 'use' of synchrotron radiation. It is hoped that the booklet serves as a pocket sized reference to facilitate back of the envelope type calculations. It contains some useful formulae in 'practical units' and a brief description of many of the existing and planned light source lattices.

  5. Radiation source with shaped emission

    DOEpatents

    Kubiak, Glenn D.; Sweatt, William C.

    2003-05-13

    Employing a source of radiation, such as an electric discharge source, that is equipped with a capillary region configured into some predetermined shape, such as an arc or slit, can significantly improve the amount of flux delivered to the lithographic wafers while maintaining high efficiency. The source is particularly suited for photolithography systems that employs a ringfield camera. The invention permits the condenser which delivers critical illumination to the reticle to be simplified from five or more reflective elements to a total of three or four reflective elements thereby increasing condenser efficiency. It maximizes the flux delivered and maintains a high coupling efficiency. This architecture couples EUV radiation from the discharge source into a ring field lithography camera.

  6. "OZONE SOURCE APPORTIONMENT IN CMAQ'

    EPA Science Inventory

    Ozone source attribution has been used to support various policy purposes including interstate transport (Cross State Air Pollution Rule) by U.S. EPA and ozone nonattainment area designations by State agencies. Common scientific applications include tracking intercontinental tran...

  7. The Sources and Solutions: Wastewater

    EPA Pesticide Factsheets

    Wastewater treatment plants process water from homes and businesses, which contains nitrogen and phosphorus from human waste, food and certain soaps and detergents, and they can be a major source of nutrient pollution.

  8. An Open Source Simulation System

    NASA Technical Reports Server (NTRS)

    Slack, Thomas

    2005-01-01

    An investigation into the current state of the art of open source real time programming practices. This document includes what technologies are available, how easy is it to obtain, configure, and use them, and some performance measures done on the different systems. A matrix of vendors and their products is included as part of this investigation, but this is not an exhaustive list, and represents only a snapshot of time in a field that is changing rapidly. Specifically, there are three approaches investigated: 1. Completely open source on generic hardware, downloaded from the net. 2. Open source packaged by a vender and provided as free evaluation copy. 3. Proprietary hardware with pre-loaded proprietary source available software provided by the vender as for our evaluation.

  9. Nonpoint Source News-Notes

    EPA Pesticide Factsheets

    an occasional bulletin dealing with the condition of the water-related environment, the control of nonpoint sources of water pollution (NPS), and the ecosystem-driven management and restoration of watersheds.

  10. Carotenoids, chemistry, sources and physiology

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This chapter for the Enclyclopedia of Human Nutrition (3rd edition) summarizes the structure, chemical and physiological mechanisms, dietary sources, and metabolism of carotenoids. Carotenoids are a family of phytonutrients which have antioxidant properties under most physiological conditions. Num...

  11. Environmental sources of fecal bacteria

    USGS Publications Warehouse

    Byappanahalli, Muruleedhara N.; Ishii, Satoshi; Sadowsky, Michael J.; Whitman, Richard L.

    2011-01-01

    This chapter provides a review of the research on environmental occurrences of faecal indicator bacteria in a variety of terrestrial and aquatic habitats under different geographic and climatic conditions, and discusses how these external sources may affect surface water quality.

  12. Source Identification and Location Techniques

    NASA Technical Reports Server (NTRS)

    Weir, Donald; Bridges, James; Agboola, Femi; Dougherty, Robert

    2001-01-01

    Mr. Weir presented source location results obtained from an engine test as part of the Engine Validation of Noise Reduction Concepts program. Two types of microphone arrays were used in this program to determine the jet noise source distribution for the exhaust from a 4.3 bypass ratio turbofan engine. One was a linear array of 16 microphones located on a 25 ft. sideline and the other was a 103 microphone 3-D "cage" array in the near field of the jet. Data were obtained from a baseline nozzle and from numerous nozzle configuration using chevrons and/or tabs to reduce the jet noise. Mr. Weir presented data from two configurations: the baseline nozzle and a nozzle configuration with chevrons on both the core and bypass nozzles. This chevron configuration had achieved a jet noise reduction of 4 EPNdB in small scale tests conducted at the Glenn Research Center. IR imaging showed that the chevrons produced significant improvements in mixing and greatly reduced the length of the jet potential core. Comparison of source location data from the 1-D phased array showed a shift of the noise sources towards the nozzle and clear reductions of the sources due to the noise reduction devices. Data from the 3-D array showed a single source at a frequency of 125 Hz. located several diameters downstream from the nozzle exit. At 250 and 400 Hz., multiple sources, periodically spaced, appeared to exist downstream of the nozzle. The trend of source location moving toward the nozzle exit with increasing frequency was also observed. The 3-D array data also showed a reduction in source strength with the addition of chevrons. The overall trend of source location with frequency was compared for the two arrays and with classical experience. Similar trends were observed. Although overall trends with frequency and addition of suppression devices were consistent between the data from the 1-D and the 3-D arrays, a comparison of the details of the inferred source locations did show differences. A

  13. Automated Classification of ROSAT Sources Using Heterogeneous Multiwavelength Source Catalogs

    NASA Technical Reports Server (NTRS)

    McGlynn, Thomas; Suchkov, A. A.; Winter, E. L.; Hanisch, R. J.; White, R. L.; Ochsenbein, F.; Derriere, S.; Voges, W.; Corcoran, M. F.

    2004-01-01

    We describe an on-line system for automated classification of X-ray sources, ClassX, and present preliminary results of classification of the three major catalogs of ROSAT sources, RASS BSC, RASS FSC, and WGACAT, into six class categories: stars, white dwarfs, X-ray binaries, galaxies, AGNs, and clusters of galaxies. ClassX is based on a machine learning technology. It represents a system of classifiers, each classifier consisting of a considerable number of oblique decision trees. These trees are built as the classifier is 'trained' to recognize various classes of objects using a training sample of sources of known object types. Each source is characterized by a preselected set of parameters, or attributes; the same set is then used as the classifier conducts classification of sources of unknown identity. The ClassX pipeline features an automatic search for X-ray source counterparts among heterogeneous data sets in on-line data archives using Virtual Observatory protocols; it retrieves from those archives all the attributes required by the selected classifier and inputs them to the classifier. The user input to ClassX is typically a file with target coordinates, optionally complemented with target IDs. The output contains the class name, attributes, and class probabilities for all classified targets. We discuss ways to characterize and assess the classifier quality and performance and present the respective validation procedures. Based on both internal and external validation, we conclude that the ClassX classifiers yield reasonable and reliable classifications for ROSAT sources and have the potential to broaden class representation significantly for rare object types.

  14. H- radio frequency source development at the Spallation Neutron Source

    SciTech Connect

    Welton, Robert F; Pennisi, Terry R; Roseberry, Ron T; Stockli, Martin P

    2012-01-01

    The Spallation Neutron Source (SNS) now routinely operates nearly 1 MW of beam power on target with a highly persistent {approx}38 mA peak current in the linac and an availability of {approx}90%. H{sup -} beam pulses ({approx}1 ms, 60 Hz) are produced by a Cs-enhanced, multicusp ion source closely coupled with an electrostatic low energy beam transport (LEBT), which focuses the 65 kV beam into a radio frequency quadrupole accelerator. The source plasma is generated by RF excitation (2 MHz, {approx}60 kW) of a copper antenna that has been encased with a thickness of {approx}0.7 mm of porcelain enamel and immersed into the plasma chamber. The ion source and LEBT normally have a combined availability of {approx}99%. Recent increases in duty-factor and RF power have made antenna failures a leading cause of downtime. This report first identifies the physical mechanism of antenna failure from a statistical inspection of {approx}75 antennas which ran at the SNS, scanning electron microscopy studies of antenna surface, and cross sectional cuts and analysis of calorimetric heating measurements. Failure mitigation efforts are then described which include modifying the antenna geometry and our acceptance/installation criteria. Progress and status of the development of the SNS external antenna source, a long-term solution to the internal antenna problem, are then discussed. Currently, this source is capable of delivering comparable beam currents to the baseline source to the SNS and, an earlier version, has briefly demonstrated unanalyzed currents up to {approx}100 mA (1 ms, 60 Hz) on the test stand. In particular, this paper discusses plasma ignition (dc and RF plasma guns), antenna reliability, magnet overheating, and insufficient beam persistence.

  15. H- radio frequency source development at the Spallation Neutron Source.

    PubMed

    Welton, R F; Dudnikov, V G; Gawne, K R; Han, B X; Murray, S N; Pennisi, T R; Roseberry, R T; Santana, M; Stockli, M P; Turvey, M W

    2012-02-01

    The Spallation Neutron Source (SNS) now routinely operates nearly 1 MW of beam power on target with a highly persistent ∼38 mA peak current in the linac and an availability of ∼90%. H(-) beam pulses (∼1 ms, 60 Hz) are produced by a Cs-enhanced, multicusp ion source closely coupled with an electrostatic low energy beam transport (LEBT), which focuses the 65 kV beam into a radio frequency quadrupole accelerator. The source plasma is generated by RF excitation (2 MHz, ∼60 kW) of a copper antenna that has been encased with a thickness of ∼0.7 mm of porcelain enamel and immersed into the plasma chamber. The ion source and LEBT normally have a combined availability of ∼99%. Recent increases in duty-factor and RF power have made antenna failures a leading cause of downtime. This report first identifies the physical mechanism of antenna failure from a statistical inspection of ∼75 antennas which ran at the SNS, scanning electron microscopy studies of antenna surface, and cross sectional cuts and analysis of calorimetric heating measurements. Failure mitigation efforts are then described which include modifying the antenna geometry and our acceptance∕installation criteria. Progress and status of the development of the SNS external antenna source, a long-term solution to the internal antenna problem, are then discussed. Currently, this source is capable of delivering comparable beam currents to the baseline source to the SNS and, an earlier version, has briefly demonstrated unanalyzed currents up to ∼100 mA (1 ms, 60 Hz) on the test stand. In particular, this paper discusses plasma ignition (dc and RF plasma guns), antenna reliability, magnet overheating, and insufficient beam persistence.

  16. Strategic Sourcing in the Army

    DTIC Science & Technology

    2013-09-01

    sector:  Total Cost of Ownership tools are applied to understand the life cycle costs of a product or service  Supplier Scorecards to apply a...sourcing efforts, as well as prioritizing new initiatives. In addition to cost and performance goals, any strategic sourcing plan must be balanced with...article/97687/ 39 INITIAL DISTRIBUTION LIST 1. Defense Technical Information Center Ft. Belvoir, Virginia 2. Dudley Knox Library Naval Postgraduate School Monterey, California

  17. Astrometry of southern radio sources.

    PubMed

    White, G L; Jauncey, D L; Harvey, B R; Savage, A; Gulkis, S; Preston, R A; Peterson, B A; Reynolds, J E; Nicolson, G D; Malin, D F

    1991-01-01

    An overview is presented of a number of astrometry and astrophysics programs based on radio sources from the Parkes 2.7 GHz catalogues. The programs cover the optical identification and spectroscopy of flat-spectrum Parkes sources and the determination of their milliarc-second radio structures and positions. Work is also in progress to tie together the radio and Hipparcos positional reference frames. A parallel program of radio and optical astrometry of southern radio stars is also under way.

  18. Data Sources for Human Behavior

    DTIC Science & Technology

    2009-08-06

    and management." Open sources of data will be discussed, as well as those found in academic settings, federally supported public archives of data, peer... media will be compared, for example the merits of archived footage, laboratory methods, self-report, observation, etc. The utility and limitations of...Std Z39-18 Academic primary sources • Have search done by professional • Search Discipline Databases Social Sciences Citation Index

  19. Unimodular gravity with external sources

    SciTech Connect

    Álvarez, Enrique; Herrero-Valea, Mario E-mail: mario.herrero@estudiante.uam.es

    2013-01-01

    The only allowed source of the gravitational field in the unimodular theory, invariant under area-preserving (transverse) diffeomorphisms as well as Weyl transformations, is just the traceless piece of the energy-momentum tensor. This fact notwithstanding, the free energy produced by arbitrary sources (not only static ones) is identical to the one predicted by general relativity. This encompasses all weak field tests of gravitation.

  20. Microseismic sources during Hurricane Sandy

    NASA Astrophysics Data System (ADS)

    Chen, Xiaohan; Tian, Dongdong; Wen, Lianxing

    2015-09-01

    We find that microseisms generated by Hurricane Sandy exhibit coherent energy within 1 h time windows in the frequency band of 0.1-0.25 Hz, but with signals correlated among seismic stations aligned along close azimuths from the hurricane center. With the identification of this signal property, we show that travel time difference can be measured between the correlated stations. These correlated seismic signals can be attributed to two types of seismic sources, with one group of the seismic signals from the hurricane center and the other from coastal region. The seismic sources in coastal region are diffusive and move northward along the coastline as Sandy moves northward. We further develop a hurricane seismic source model, to quantitatively describe the coupling among sea level pressure fluctuations, ocean waves, and solid Earth in the region of hurricane center and determine the evolution of source's strength and pressure fluctuation in the region of hurricane center using seismic data. Strong seismic sources are also identified near the coastal region in New England after Sandy's dissipation, possibly related to subsequent storm surge in the area. The seismic method may be implemented as another practical means for hurricane monitoring, and seismological estimates of the hurricane seismic source model could be used as in situ proxy measurements of pressure fluctuation in the region of hurricane center for hurricane physics studies.

  1. rf improvements for Spallation Neutron Source H- ion source.

    PubMed

    Kang, Y W; Fuja, R; Goulding, R H; Hardek, T; Lee, S-W; McCarthy, M P; Piller, M C; Shin, K; Stockli, M P; Welton, R F

    2010-02-01

    The Spallation Neutron Source at Oak Ridge National Laboratory is ramping up the accelerated proton beam power to 1.4 MW and just reached 1 MW. The rf-driven multicusp ion source that originates from the Lawrence Berkeley National Laboratory has been delivering approximately 38 mA H(-) beam in the linac at 60 Hz, 0.9 ms. To improve availability, a rf-driven external antenna multicusp ion source with a water-cooled ceramic aluminum nitride (AlN) plasma chamber is developed. Computer modeling and simulations have been made to analyze and optimize the rf performance of the new ion source. Operational statistics and test runs with up to 56 mA medium energy beam transport beam current identify the 2 MHz rf system as a limiting factor in the system availability and beam production. Plasma ignition system is under development by using a separate 13 MHz system. To improve the availability of the rf power system with easier maintenance, we tested a 70 kV isolation transformer for the 80 kW, 6% duty cycle 2 MHz amplifier to power the ion source from a grounded solid-state amplifier.

  2. Multilevel cascade voltage source inverter with separate DC sources

    DOEpatents

    Peng, F.Z.; Lai, J.S.

    1997-06-24

    A multilevel cascade voltage source inverter having separate DC sources is described herein. This inverter is applicable to high voltage, high power applications such as flexible AC transmission systems (FACTS) including static VAR generation (SVG), power line conditioning, series compensation, phase shifting and voltage balancing and fuel cell and photovoltaic utility interface systems. The M-level inverter consists of at least one phase wherein each phase has a plurality of full bridge inverters equipped with an independent DC source. This inverter develops a near sinusoidal approximation voltage waveform with only one switching per cycle as the number of levels, M, is increased. The inverter may have either single-phase or multi-phase embodiments connected in either wye or delta configurations. 15 figs.

  3. Multilevel cascade voltage source inverter with seperate DC sources

    DOEpatents

    Peng, Fang Zheng; Lai, Jih-Sheng

    1997-01-01

    A multilevel cascade voltage source inverter having separate DC sources is described herein. This inverter is applicable to high voltage, high power applications such as flexible AC transmission systems (FACTS) including static VAR generation (SVG), power line conditioning, series compensation, phase shifting and voltage balancing and fuel cell and photovoltaic utility interface systems. The M-level inverter consists of at least one phase wherein each phase has a plurality of full bridge inverters equipped with an independent DC source. This inverter develops a near sinusoidal approximation voltage waveform with only one switching per cycle as the number of levels, M, is increased. The inverter may have either single-phase or multi-phase embodiments connected in either wye or delta configurations.

  4. Multilevel cascade voltage source inverter with seperate DC sources

    DOEpatents

    Peng, Fang Zheng; Lai, Jih-Sheng

    2002-01-01

    A multilevel cascade voltage source inverter having separate DC sources is described herein. This inverter is applicable to high voltage, high power applications such as flexible AC transmission systems (FACTS) including static VAR generation (SVG), power line conditioning, series compensation, phase shifting and voltage balancing and fuel cell and photovoltaic utility interface systems. The M-level inverter consists of at least one phase wherein each phase has a plurality of full bridge inverters equipped with an independent DC source. This inverter develops a near sinusoidal approximation voltage waveform with only one switching per cycle as the number of levels, M, is increased. The inverter may have either single-phase or multi-phase embodiments connected in either wye or delta configurations.

  5. Multilevel cascade voltage source inverter with seperate DC sources

    DOEpatents

    Peng, Fang Zheng; Lai, Jih-Sheng

    2001-04-03

    A multilevel cascade voltage source inverter having separate DC sources is described herein. This inverter is applicable to high voltage, high power applications such as flexible AC transmission systems (FACTS) including static VAR generation (SVG), power line conditioning, series compensation, phase shifting and voltage balancing and fuel cell and photovoltaic utility interface systems. The M-level inverter consists of at least one phase wherein each phase has a plurality of full bridge inverters equipped with an independent DC source. This inverter develops a near sinusoidal approximation voltage waveform with only one switching per cycle as the number of levels, M, is increased. The inverter may have either single-phase or multi-phase embodiments connected in either wye or delta configurations.

  6. Passive acoustic source localization using sources of opportunity.

    PubMed

    Verlinden, Christopher M A; Sarkar, J; Hodgkiss, W S; Kuperman, W A; Sabra, K G

    2015-07-01

    The feasibility of using data derived replicas from ships of opportunity for implementing matched field processing is demonstrated. The Automatic Identification System (AIS) is used to provide the library coordinates for the replica library and a correlation based processing procedure is used to overcome the impediment that the replica library is constructed from sources with different spectra and will further be used to locate another source with its own unique spectral structure. The method is illustrated with simulation and then verified using acoustic data from a 2009 experiment for which AIS information was retrieved from the United States Coast Guard Navigation Center Nationwide AIS database.

  7. Design parameters and source terms: Volume 3, Source terms

    SciTech Connect

    Not Available

    1987-10-01

    The Design Parameters and Source Terms Document was prepared in accordance with DOE request and to provide data for the environmental impact study to be performed in the future for the Deaf Smith County, Texas site for a nuclear waste repository in salt. This document updates a previous unpublished report by Stearns Catalytic Corporation (SCC), entitled ''Design Parameters and Source Terms for a Two-Phase Repository in Salt,'' 1985, to the level of the Site Characterization Plan - Conceptual Design Report. The previous unpublished SCC Study identifies the data needs for the Environmental Assessment effort for seven possible Salt Repository sites. 11 refs., 9 tabs.

  8. Quantitative estimation of source complexity in tsunami-source inversion

    NASA Astrophysics Data System (ADS)

    Dettmer, Jan; Cummins, Phil R.; Hawkins, Rhys; Jakir Hossen, M.

    2016-04-01

    This work analyses tsunami waveforms to infer the spatiotemporal evolution of sea-surface displacement (the tsunami source) caused by earthquakes or other sources. Since the method considers sea-surface displacement directly, no assumptions about the fault or seafloor deformation are required. While this approach has no ability to study seismic aspects of rupture, it greatly simplifies the tsunami source estimation, making it much less dependent on subjective fault and deformation assumptions. This results in a more accurate sea-surface displacement evolution in the source region. The spatial discretization is by wavelet decomposition represented by a trans-D Bayesian tree structure. Wavelet coefficients are sampled by a reversible jump algorithm and additional coefficients are only included when required by the data. Therefore, source complexity is consistent with data information (parsimonious) and the method can adapt locally in both time and space. Since the source complexity is unknown and locally adapts, no regularization is required, resulting in more meaningful displacement magnitudes. By estimating displacement uncertainties in a Bayesian framework we can study the effect of parametrization choice on the source estimate. Uncertainty arises from observation errors and limitations in the parametrization to fully explain the observations. As a result, parametrization choice is closely related to uncertainty estimation and profoundly affects inversion results. Therefore, parametrization selection should be included in the inference process. Our inversion method is based on Bayesian model selection, a process which includes the choice of parametrization in the inference process and makes it data driven. A trans-dimensional (trans-D) model for the spatio-temporal discretization is applied here to include model selection naturally and efficiently in the inference by sampling probabilistically over parameterizations. The trans-D process results in better

  9. Radio outbursts in extragalactic sources

    NASA Astrophysics Data System (ADS)

    Kinzel, Wayne Morris

    Three aspects of the flux density variability of extragalactic radio sources were examined: millimeter wavelength short timescale variability, the spectral evolution of outbursts, and whether the outbursts are periodically spaced. Observations of extragalactic radio sources were conducted using the Five College Radio Astronomy Observatory between January and June 1985 at 88.2 GHz and during June and July 1985 at 40.0 GHz. Many of the sources exhibited significant flux density variations during the observing span. In addition, the most rapid variations observed were comparable with those reported in previous works. Two sources, 0355+50 and OJ287, both exhibited outbursts whose rise and fall timescales were less than a month. An anomalous flux density dropout was observed in 3C446 and was interpreted as an occultation event. Data at five frequencies between 2.7 and 89.6 GHz from the Dent-Balonek monitoring program were used to investigate the spectral evolution of eight outbursts. Outburst profile fitting was used to deconvolve the individual outbursts from one another at each frequency. The fit profiles were used to generate multiple epoch spectra to investigate the evolution of the outbursts. A phase residual minimization method was used to examine four sources for periodic behavior.

  10. Compton Sources of Electromagnetic Radiation

    SciTech Connect

    Geoffrey Krafft,Gerd Priebe

    2011-01-01

    When a relativistic electron beam interacts with a high-field laser beam, intense and highly collimated electromagnetic radiation will be generated through Compton scattering. Through relativistic upshifting and the relativistic Doppler effect, highly energetic polarized photons are radiated along the electron beam motion when the electrons interact with the laser light. For example, X-ray radiation can be obtained when optical lasers are scattered from electrons of tens-of-MeV beam energy. Because of the desirable properties of the radiation produced, many groups around the world have been designing, building, and utilizing Compton sources for a wide variety of purposes. In this review article, we discuss the generation and properties of the scattered radiation, the types of Compton source devices that have been constructed to date, and the prospects of radiation sources of this general type. Due to the possibilities of producing hard electromagnetic radiation in a device that is small compared to the alternative storage ring sources, it is foreseen that large numbers of such sources may be constructed in the future.

  11. Ultraluminous X-ray Sources.

    NASA Astrophysics Data System (ADS)

    Fabrika, S.; Sholukhova, O.; Abolmasov, P.

    2008-12-01

    We discuss a new type of X-ray sources discovered in galaxies -- ultraluminous X-ray sources (ULXs). They are of two order of magnitude brighter in X-rays than the brightest Galactic black holes. Two mod- els of ULXs are discussed: "intermediate mass" black holes, 100 - 10000 solar masses, with standard accretion disks, and "stellar mass" black holes with su- percritical accretion disks like that in the Galactic object SS 433. A study of gas nebulae surrounding these objects gives us a new important information on the central sources. The observed X-ray radiation of ULXs is not enough to power their nebulae. To understand both spectra and power of the nebulae one needs a powerful UV source. The ULXs must be such bright in UV range as they are in X-rays. Spectroscopy of gas filaments surrounding SS 433 proves that the intrinsic face-on luminosity of the supercritical accretion disk in the far UV region to be "sim; 10^40 erg/s. We expect that observations of ULXs with the WSO-UV Observatory, measurements their UV fluxes and spectral slopes solve the problem of ULXs between the two known models of these sources.

  12. Evaluation of cardiac emboli source

    PubMed Central

    Michels, M.; Meijboom, F.J.; ten Cate, F.J.

    2005-01-01

    Background Evaluating the source of cardiac embolism is one of the most frequent reasons for cardiac consultation. Methods In 2003, 99 patients were referred for the evaluation of the source of cardiac emboli. Evaluation included history, physical examination, ECG, transoesophageal echocardiography (TOE) with contrast and 24-hour Holter electrocardiography. Results Altogether, 58 men and 41 women were studied. In 32 patients a possible source of the cardiac emboli was found. Two patients were in atrial fibrillation. Of the patients, 16 had a patent foramen ovale (PFO) and six patients a PFO and atrial septum aneurysm (ASA). Two patients had a thrombus in the left atrial appendage and 14 had severe atherosclerosis in the aortic arch. In eight patients we found two possible cardiac sources of embolism. 24-hour Holter recording did not detect any emboligenic arrhythmias. Conclusion A possible cardiac source of embolism was found in 32% of the patients referred. TOE is the ideal tool to visualise the interatrial septum, left atrial appendage and aortic arch. We advise performing a TOE with contrast in young stroke patients and in older patients with a stroke likely to be caused by an embolism of cardiac origin. 24-hour Holter recording did not detect any emboligenic arrhythmias and should only be done in selected cases. ImagesFigure 1Figure 2 PMID:25696441

  13. Low-pressure ion source

    SciTech Connect

    Bacon, F.M.; Brainard, J.P.; O'Hagan, J.B.; Walko, R.J.

    1982-10-27

    A low pressure ion source for a neutron source comprises a filament cathode and an anode ring. Approximately 150V is applied between the cathode and the anode. Other electrodes, including a heat shield, a reflector and an aperture plate with a focus electrode, are placed at intermediate potentials. Electrons from the filament drawn out by the plasma and eventually removed by the anode are contained in a magnetic field created by a magnet ring. Ions are formed by electron impact with deuterium or tritium and are extracted at the aperture in the focus electrode. The ion source will typically generate a 200 mA beam through a 1.25 cm/sup 2/ aperture for an arc current of 10A. For deuterium gas, the ion beam is over 50 percent D/sup +/ with less than 1% impurity. The current density profile across the aperture will typically be uniform to within 20%.

  14. ANS cold source neutronics analysis

    SciTech Connect

    Lillie, R.A.

    1994-06-01

    This paper describes the calculational procedures employed in the ongoing neutronics analysis of the ANS cold source and presents in chronological order some of the more important results from the one- and two-dimensional discrete calculations performed to date in support of the ANS cold source design. In particular, cold neutron currents from cryostat shapes which can be adequately modeled with two-dimensional geometries are compared with and without reentrant cavities. Also, results are presented from one-dimensional comparative liquid hydrogen vs liquid deuterium calculations in which the density, placement, and para-ortho mixture of liquid hydrogen is investigated. In addition, the evolution of the ANS conceptual design cold source from an initial short cylindrical cryostat with hemispherical upper and lower heads employing a natural convection liquid deuterium circulation system to the final spherical design employing a pumped system is described. Finally, performance data and heating rates are presented for some possible alternate ANS cryostat and vacuum jacket materials.

  15. Negative-ion plasma sources

    NASA Astrophysics Data System (ADS)

    Sheehan, D. P.; Rynn, N.

    1988-08-01

    Three designs for negative-ion plasma sources are described. Two sources utilize metal hexafluorides such as SF6 and WF6 to scavenge electrons from electron-ion plasmas and the third relies upon surface ionization of alkali halide salts on heated alumina and zirconia. SF6 introduced into electron-ion plasmas yielded negative-ion plasma densities of 10 to the 10th/cu cm with low residual electron densities. On alumina, plasma densities of 10 to the 9th/cu cm were obtained for CsCl, CsI, and KI and 10 to the 9th/cu cm for KCl. On zirconia 10 to the 10th/cu cm densities were obtained for CsCl. For alkali halide sources, electron densities of less than about 10 to the -4th have been achieved.

  16. Pulsed reflex ion source studies

    SciTech Connect

    Bickes, Jr., R. W.; O'Hagan, J. B.

    1980-11-01

    Parametric studies of demountable versions of the pulsed ion source used in Controlatron and Zetatron neutron tubes were carried out. The goal of these experiments, a continuation of earlier work by Bacon and O'Hagan, was to investigate the deuteron beam intensity as a function of source geometry, electrode materials, operating conditions and pulse length. Geometric variations produced only modest changes in the ion beam intensity; the most sensitive parameter was the length of the secondary cathode. There is some evidence that the addition of oxygen either in the gas feed or using alumina on the cathode surfaces can increase the atomic ion fraction. The lowest reliable operating source pressure was approximately 1.33 Pa. The longest pulse length was about 1.2 ms. Difficulties in measuring the ion currents are discussed and suggestions for future experiments are briefly outlined.

  17. Stacee Observations of Extragalactic Sources

    NASA Astrophysics Data System (ADS)

    Mukherjee, R.; Boone, L. M.; Bramel, D.; Covault, C. E.; Fortin, P.; Gingrich, D.; Hanna, D.; Hinton, J. A.; Mueller, C.; Ong, R. A.; Ragan, K.; Scalzo, R. A.; Schuette, D. R.; Williams, D. A.

    2002-04-01

    The Solar Tower Atmospheric Cherenkov Effect Experiment (STACEE) is a ground-based gamma-ray telescope employing the atmospheric Cherenkov technique. STACEE uses 64 large heliostats at a solar research facility near Albuquerque NM, USA, to achieve a gamma-ray energy threshold below traditional imaging telescopes. The full STACEE experiment started regular observations in October, 2001. An earlier version of the experiment using 48 heliostats took data between January and June of 2001. Here we report the results from STACEE observations of extragalactic sources in 2001 and 2002. The sources observed include the active galaxies Markarian 421, Markarian 501, 3C 66A, and W Comae. We also summarize our future observing plan in the context of measuring the absorbtion of high energy emission due to radiation fields at the source, or in intergalactic space.

  18. Miniature x-ray source

    DOEpatents

    Trebes, James E.; Stone, Gary F.; Bell, Perry M.; Robinson, Ronald B.; Chornenky, Victor I.

    2002-01-01

    A miniature x-ray source capable of producing broad spectrum x-ray emission over a wide range of x-ray energies. The miniature x-ray source comprises a compact vacuum tube assembly containing a cathode, an anode, a high voltage feedthru for delivering high voltage to the anode, a getter for maintaining high vacuum, a connection for an initial vacuum pump down and crimp-off, and a high voltage connection for attaching a compact high voltage cable to the high voltage feedthru. At least a portion of the vacuum tube wall is highly x-ray transparent and made, for example, from boron nitride. The compact size and potential for remote operation allows the x-ray source, for example, to be placed adjacent to a material sample undergoing analysis or in proximity to the region to be treated for medical applications.

  19. Graphite moderated (252)Cf source.

    PubMed

    Sajo-Bohus, Laszlo; Barros, Haydn; Greaves, Eduardo D; Vega-Carrillo, Hector Rene

    2015-06-01

    The Thorium molten-salt reactor is an attractive and affordable nuclear power option for developing countries with insufficient infrastructure and limited technological capability. In the aim of personnel training and experience gathering at the Universidad Simon Bolivar there is in progress a project of developing a subcritical thorium liquid-fuel reactor. The neutron source to run this subcritical reactor is a (252)Cf source and the reactor will use high-purity graphite as moderator. Using the MCNP5 code the neutron spectra of the (252)Cf in the center of the graphite moderator has been estimated along the channel where the liquid thorium salt will be inserted; also the ambient dose equivalent due to the source has been determined around the moderator.

  20. Miniature x-ray source

    DOEpatents

    Trebes, James E.; Bell, Perry M.; Robinson, Ronald B.

    2000-01-01

    A miniature x-ray source utilizing a hot filament cathode. The source has a millimeter scale size and is capable of producing broad spectrum x-ray emission over a wide range of x-ray energies. The miniature source consists of a compact vacuum tube assembly containing the hot filament cathode, an anode, a high voltage feedthru for delivering high voltage to the cathode, a getter for maintaining high vacuum, a connector for initial vacuum pump down and crimp-off, and a high voltage connection for attaching a compact high voltage cable to the high voltage feedthru. At least a portion of the vacuum tube wall is fabricated from highly x-ray transparent materials, such as sapphire, diamond, or boron nitride.

  1. A review of terahertz sources

    NASA Astrophysics Data System (ADS)

    Lewis, R. A.

    2014-09-01

    Bibliometric data set the scene by illustrating the growth of terahertz work and the present interest in terahertz science and technology. After locating terahertz sources within the broader context of terahertz systems, an overview is given of the range of available sources, emphasizing recent developments. The focus then narrows to terahertz sources that rely on surface phenomena. Three are highlighted. Optical rectification, usually thought of as a bulk process, may in addition exhibit a surface contribution, which, in some cases, predominates. Transient surface currents, for convenience often separated into drift and diffusion currents, are well understood according to Monte Carlo modelling. Finally, terahertz surface emission by mechanical means—in the absence of photoexcitation—is described.

  2. 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.

  3. LIGHT SOURCE: Conceptual design of Hefei advanced light source

    NASA Astrophysics Data System (ADS)

    Li, Wei-Min; Wang, Lin; Feng, Guang-Yao; Zhang, Shan-Cai; Wu, Cong-Feng; Xu, Hong-Liang; Liu, Zu-Ping

    2009-06-01

    The conceptual of Hefei Advanced Light Source, which is an advanced VUV and Soft X-ray source, was developed at NSRL of USTC. According to the synchrotron radiation user requirements and the trends of SR source development, some accelerator-based schemes were considered and compared; furthermore storage ring with ultra low emittance was adopted as the baseline scheme of HALS. To achieve ultra low emittance, some focusing structures were studied and optimized in the lattice design. Compromising of emittance, on-momentum and off-momentum dynamic aperture and ring scale, five bend acromat (FBA) was employed. In the preliminary design of HALS, the emittance was reduced to sub nm · rad, thus the radiation up to water window has full lateral coherence. The brilliance of undulator radiation covering several eVs to keVs range is higher than that of HLS by several orders. The HALS should be one of the most advanced synchrotron radiation light sources in the world.

  4. Microbial source tracking: a forensic technique for microbial source identification?

    PubMed

    Stapleton, Carl M; Wyer, Mark D; Kay, David; Crowther, John; McDonald, Adrian T; Walters, Martin; Gawler, Andrew; Hindle, Terry

    2007-05-01

    As the requirements of the Water Framework Directive (WFD) and the US Clean Water Act (USCWA) for the maintenance of microbiological water quality in 'protected areas' highlight, there is a growing recognition that integrated management of point and diffuse sources of microbial pollution is essential. New information on catchment microbial dynamics and, in particular, the sources of faecal indicator bacteria found in bathing and shellfish harvesting waters is a pre-requisite for the design of any 'programme of measures' at the drainage basin scale to secure and maintain compliance with existing and new health-based microbiological standards. This paper reports on a catchment-scale microbial source tracking (MST) study in the Leven Estuary drainage basin, northwest England, an area for which quantitative faecal indicator source apportionment empirical data and land use information were also collected. Since previous MST studies have been based on laboratory trials using 'manufactured' samples or analyses of spot environmental samples without the contextual microbial flux data (under high and low flow conditions) and source information, such background data are needed to evaluate the utility of MST in USCWA total maximum daily load (TMDL) assessments or WFD 'Programmes of Measures'. Thus, the operational utility of MST remains in some doubt. The results of this investigation, using genotyping of Bacteroidetes using polymerase chain reaction (PCR) and male-specific ribonucleic acid coliphage (F + RNA coliphage) using hybridisation, suggest some discrimination is possible between livestock- and human-derived faecal indicator concentrations but, in inter-grade areas, the degree to which the tracer picture reflected the land use pattern and probable faecal indicator loading were less distinct. Interestingly, the MST data was more reliable on high flow samples when much of the faecal indicator flux from catchment systems occurs. Whilst a useful supplementary tool, the MST

  5. The Herschel Point Source Catalogue

    NASA Astrophysics Data System (ADS)

    Marton, Gabor; Schulz, Bernhard; Altieri, Bruno; Calzoletti, Luca; Kiss, Csaba; Lim, Tanya; Lu, Nanyao; Paladini, Roberta; Papageorgiou, Andreas; Pearson, Chris; Rector, John; Shupe, David; Valtchanov, Ivan; Verebélyi, Erika; Xu, Kevin

    2015-08-01

    The Herschel Space Observatory was the fourth cornerstone mission in the European Space Agency (ESA) science programme with excellent broad band imaging capabilities in the submillimetre and far-infrared part of the spectrum. Although the spacecraft finished its observations in 2013, it left a large legacy dataset that is far from having been fully scrutinized and still has potential for new scientific discoveries. This is specifically true for the photometric observations of the PACS and SPIRE instruments that scanned >10% of the sky at 70, 100, 160, 250, 350 and 500 microns. Some source catalogs have already been produced by individual observing programs, but there are many observations that would never be analyzed for their full source content. To maximize the science return of the SPIRE and PACS data sets, our international team of instrument experts is in the process of building the Herschel Point Source Catalog (HPSC) from all scan map observations. Our homogeneous source extraction enables a systematic and unbiased comparison of sensitivity across the different Herschel fields that single programs will generally not be able to provide. The extracted point sources will contain individual YSOs of our Galaxy, unresolved YSO clusters in resolved nearby galaxies and unresolved galaxies of the local and distant Universe that are related to star formation. Such a huge dataset will help scientists better understand the evolution from interstellar clouds to individual stars. Furthermore the analysis of stellar clusters and the star formation on galactic scales will add more details to the understanding of star formation laws through time.We present our findings on comparison of different source detection and photometric tools. First results of the extractions are shown along with the description of our pipelines and catalogue entries. We also provide an additional science product, the structure noise map, that is used for the quality assessment of the catalogue in

  6. SOURCE PHENOMENOLOGY EXPERIMENTS IN ARIZONA

    SciTech Connect

    Jessie L. Bonner; Brian Stump; Mark Leidig; Heather Hooper; Xiaoning Yang; Rongmao Zhou; Tae Sung Kim; William R. Walter; Aaron Velasco; Chris Hayward; Diane Baker; C. L. Edwards; Steven Harder; Travis Glenn; Cleat Zeiler; James Britton; James F. Lewkowicz

    2005-09-30

    The Arizona Source Phenomenology Experiments (SPE) have resulted in an important dataset for the nuclear monitoring community. The 19 dedicated single-fired explosions and multiple delay-fired mining explosions were recorded by one of the most densely instrumented accelerometer and seismometer arrays ever fielded, and the data have already proven useful in quantifying confinement and excitation effects for the sources. It is very interesting to note that we have observed differences in the phenomenology of these two series of explosions resulting from the differences between the relatively slow (limestone) and fast (granodiorite) media. We observed differences at the two SPE sites in the way the rock failed during the explosions, how the S-waves were generated, and the amplitude behavior as a function of confinement. Our consortium's goal is to use the synergy of the multiple datasets collected during this experiment to unravel the phenomenological differences between the two emplacement media. The data suggest that the main difference between single-fired chemical and delay-fired mining explosion seismograms at regional distances is the increased surface wave energy for the latter source type. The effect of the delay-firing is to decrease the high-frequency P-wave amplitudes while increasing the surface wave energy because of the longer source duration and spall components. The results suggest that the single-fired explosions are surrogates for nuclear explosions in higher frequency bands (e.g., 6-8 Hz Pg/Lg discriminants). We have shown that the SPE shots, together with the mining explosions, are efficient sources of S-wave energy, and our next research stage is to postulate the possible sources contributing to the shear-wave energy.

  7. Source counting in MEG neuroimaging

    NASA Astrophysics Data System (ADS)

    Lei, Tianhu; Dell, John; Magee, Ralphy; Roberts, Timothy P. L.

    2009-02-01

    Magnetoencephalography (MEG) is a multi-channel, functional imaging technique. It measures the magnetic field produced by the primary electric currents inside the brain via a sensor array composed of a large number of superconducting quantum interference devices. The measurements are then used to estimate the locations, strengths, and orientations of these electric currents. This magnetic source imaging technique encompasses a great variety of signal processing and modeling techniques which include Inverse problem, MUltiple SIgnal Classification (MUSIC), Beamforming (BF), and Independent Component Analysis (ICA) method. A key problem with Inverse problem, MUSIC and ICA methods is that the number of sources must be detected a priori. Although BF method scans the source space on a point-to-point basis, the selection of peaks as sources, however, is finally made by subjective thresholding. In practice expert data analysts often select results based on physiological plausibility. This paper presents an eigenstructure approach for the source number detection in MEG neuroimaging. By sorting eigenvalues of the estimated covariance matrix of the acquired MEG data, the measured data space is partitioned into the signal and noise subspaces. The partition is implemented by utilizing information theoretic criteria. The order of the signal subspace gives an estimate of the number of sources. The approach does not refer to any model or hypothesis, hence, is an entirely data-led operation. It possesses clear physical interpretation and efficient computation procedure. The theoretical derivation of this method and the results obtained by using the real MEG data are included to demonstrates their agreement and the promise of the proposed approach.

  8. Development of Radioisotope Micropower Sources

    NASA Astrophysics Data System (ADS)

    Robertson, J. David

    2016-09-01

    Microelectromechanical systems (MEMS) are considered to be one of the discriminating technologies of the 21st century. In order to take full advantage of the MEMS revolution, the power sources for these electromechanical systems must follow a similar trend of increased functionality at decreased size. Because of their high energy density, radioactive micropower sources are an alternative to next generation battery and fuel cell technologies for applications where volume is at a premium. This presentation will focus on our development of liquid-semiconductor nuclear batteries as compact power supplies for MEMS.

  9. Accelerator based epithermal neutron source

    NASA Astrophysics Data System (ADS)

    Taskaev, S. Yu.

    2015-11-01

    We review the current status of the development of accelerator sources of epithermal neutrons for boron neutron capture therapy (BNCT), a promising method of malignant tumor treatment. Particular attention is given to the source of epithermal neutrons on the basis of a new type of charged particle accelerator: tandem accelerator with vacuum insulation and lithium neutron-producing target. It is also shown that the accelerator with specialized targets makes it possible to generate fast and monoenergetic neutrons, resonance and monoenergetic gamma-rays, alpha-particles, and positrons.

  10. The SLAC polarized electron source

    SciTech Connect

    Tang, H.; Alley, R.; Frisch, J.

    1995-06-01

    The SLAC polarized electron source employs a photocathode DC high voltage gun with a loadlock and a YAG pumped Ti:sapphire laser system for colliding beam experiments or a flash lamp pumped Ti:sapphire laser for fixed target experiments. It uses a thin, strained GaAs(100) photocathode, and is capable of producing a pulsed beam with a polarization of {ge}80% and a peak current exceeding 10 A. Its operating efficiency has reached 99%. The physics and technology of producing high polarization electron beams from a GaAs photocathode will be reviewed. The prospects of realizing a polarized electron source for future linear colliders will also be discussed.

  11. Energy source for comet outbursts

    NASA Technical Reports Server (NTRS)

    Patashnick, H.; Schuerman, D. W.; Rupprecht, G.

    1974-01-01

    Development of a mechanism explaining the internal source of energy of comet outbursts. A mechanism is proposed which automatically provides a source of particulate matter which creates a huge surface area which contains a substantial percentage of amorphous ice, so that the phase transition of the amorphous ice to a cubic structure provides a release of energy which may be responsible for the outbursts observed in many comets. In addition, the volume into which the transition can propagate is estimated for a spherical comet with a radius of 5 km.

  12. Online bibliographic sources in hydrology

    USGS Publications Warehouse

    Wild, Emily C.; Havener, W. Michael

    2001-01-01

    Traditional commercial bibliographic databases and indexes provide some access to hydrology materials produced by the government; however, these sources do not provide comprehensive coverage of relevant hydrologic publications. This paper discusses bibliographic information available from the federal government and state geological surveys, water resources agencies, and depositories. In addition to information in these databases, the paper describes the scope, styles of citing, subject terminology, and the ways these information sources are currently being searched, formally and informally, by hydrologists. Information available from the federal and state agencies and from the state depositories might be missed by limiting searches to commercially distributed databases.

  13. Tikal obsidian: sources and typology

    SciTech Connect

    Moholy-Nagy, H.; Asaro, F.; Stross, F.H.

    1984-01-01

    The obsidian industry of Classic period Tikal, Guatemala, is discussed with regard to geological source determinations and behavioral typology. The potential of these two approaches for cultural reconstruction is greatly extended when they can supplement each other. Recent source determinations of obsidian artifacts from Tikal indicate (1) a behavioral link between locally-produced prismatic blades of Highland Guatemalan stone and ceremonial incised obsidians and eccentrics, and (2) a Central Mexican origin for a seemingly large portion of Tikal's obsidian projectile points and knives. 25 references, 3 figures, 5 tables.

  14. 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...

  15. The Source for Asperger's Syndrome.

    ERIC Educational Resources Information Center

    Kowalski, Timothy P.

    This book is intended as a comprehensive source of information on the diagnosis and treatment of Asperger syndrome. Chapter 1 discusses major classification of characteristics and chapter 2 describes prevalence, comorbidity, and causal factors of Asperger syndrome. Chapter 3 examines clinical diagnosis and misdiagnosis and the influence of…

  16. Compact Photon Source Conceptual Design

    SciTech Connect

    Degtyarenko, Pavel V.; Wojtsekhowski, Bogdan B.

    2016-04-01

    We describe options for the production of an intense photon beam at the CEBAF Hall D Tagger facility, needed for creating a high-quality secondary K 0 L delivered to the Hall D detector. The conceptual design for the Compact Photon Source apparatus is presented.

  17. Energy Sources: An Historical Perspective.

    ERIC Educational Resources Information Center

    Perry, Constance M.

    1983-01-01

    Putting the present energy situation into an historical perspective provides meaning to today's energy concerns and demonstrates how important energy has always been to our life style. Primary energy sources of the United States from 1850 to the present are examined. (RM)

  18. National Synchrotron Light Source II

    SciTech Connect

    Hill, John; Dooryhee, Eric; Wilkins, Stuart; Miller, Lisa; Chu, Yong

    2016-04-25

    NSLS-II is a synchrotron light source helping researchers explore solutions to the grand energy challenges faced by the nation, and open up new regimes of scientific discovery that will pave the way to discoveries in physics, chemistry, and biology — advances that will ultimately enhance national security and help drive the development of abundant, safe, and clean energy technologies.

  19. Sources and Types of Software.

    ERIC Educational Resources Information Center

    Trautman, Rodes

    1987-01-01

    Describes possible sources of computer software, including hardware bundles, commercial suppliers, users groups, electronic bulletin boards, as payment for software review services, prototype contracts, and writing the software oneself. Advantages and disadvantages of each, especially in terms of technical support, are discussed. (CLB)

  20. National Synchrotron Light Source II

    ScienceCinema

    Hill, John; Dooryhee, Eric; Wilkins, Stuart; Miller, Lisa; Chu, Yong

    2016-07-12

    NSLS-II is a synchrotron light source helping researchers explore solutions to the grand energy challenges faced by the nation, and open up new regimes of scientific discovery that will pave the way to discoveries in physics, chemistry, and biology — advances that will ultimately enhance national security and help drive the development of abundant, safe, and clean energy technologies.

  1. Sources of Information about Magazines.

    ERIC Educational Resources Information Center

    Magazine Publishers Association, Inc., New York, NY.

    This booklet was prepared by the Magazine Publishers Association as a guide to some of the available sources of information about consumer magazines. Some of the data provided by the services listed in this booklet are based on circulation audits, actual measurements of advertising space, or factual statements of procedure and mechanical details.…

  2. Focused X-ray source

    DOEpatents

    Piestrup, M.A.; Boyers, D.G.; Pincus, C.I.; Maccagno, P.

    1990-08-21

    Disclosed is an intense, relatively inexpensive X-ray source (as compared to a synchrotron emitter) for technological, scientific, and spectroscopic purposes. A conical radiation pattern produced by a single foil or stack of foils is focused by optics to increase the intensity of the radiation at a distance from the conical radiator. 8 figs.

  3. Focused X-ray source

    DOEpatents

    Piestrup, Melvin A.; Boyers, David G.; Pincus, Cary I.; Maccagno, Pierre

    1990-01-01

    An intense, relatively inexpensive X-ray source (as compared to a synchrotron emitter) for technological, scientific, and spectroscopic purposes. A conical radiation pattern produced by a single foil or stack of foils is focused by optics to increase the intensity of the radiation at a distance from the conical radiator.

  4. Govt. Pubs.: NTIS Reference Sources.

    ERIC Educational Resources Information Center

    Korman, Richard; Aluri, Rao

    1980-01-01

    Cites review sources for NTIS (National Technical Information Service) publications and provides an annotated list of 22 reports on child abuse, Chinese language romanization, criminal justice, energy, environment, ethnic data, fire technology, genealogy, health care, local communities and federal assistance, mainstreaming, political leadership in…

  5. Primary Sources and Inquiry Learning

    ERIC Educational Resources Information Center

    Pappas, Marjorie L.

    2006-01-01

    In this article, the author discusses inquiry learning and primary sources. Inquiry learning puts students in the active role of investigators. Questioning, authentic and active learning, and interactivity are a few of the characteristics of inquiry learning that put the teacher and library media specialist in the role of coaches while students…

  6. Laser undulated synchrotron radiation sources

    NASA Astrophysics Data System (ADS)

    Baine, Michael A. J.

    2000-07-01

    This work will address the practicality of using lasers to undulate electron beams for the production of tunable, short pulsed, monochromatic, synchrotron radiation. An x-ray source based on this mechanism, referred to as a Laser Synchrotron Source (LSS), has several attractive features: (1)x-rays can be generated with an electron beam whose energy is a factor of 100 smaller than competing synchrotron sources that use magnetic undulators, (2)the pulse length can be made extremely short (<100fs) by using short pulsed lasers, (3)the polarization can be controlled by changing the polarization of the incident laser, (4)the bandwidth can be quite narrow (<1%), and (5)the resultant x-rays are well collimated (θ < .1 rad for γ > 10) in the direction of the electron beam. These factors combine to produce one of the brightest (>1018 J/s mrad mm2 1%BW) sources of x-rays available. The most attractive feature, however, is its compact size and low cost, which suit it well for applications in Medicine, Biology, and Physics. The problem will be treated in two parts: analysis of nonlinear Thomson scattering for arbitrary interaction geometry of intense lasers and relativistic electron beams, and description of a proof-of-principle experiment carried out at the Naval Research Laboratory.

  7. History Sources on the Internet.

    ERIC Educational Resources Information Center

    Fink, Kenneth D.

    This paper provides descriptions of key online history resources useful to teachers, librarians, and other education professionals. Highlights include: primary sources on the Internet; archives; Online Public Access Catalogs (OPACs); the American Historical Association (AHA) Web site; state and federal government resources; business history…

  8. Primary Sources Enliven Civil War

    ERIC Educational Resources Information Center

    Robelen, Erik W.

    2011-01-01

    Today, a growing number of teachers are moving beyond the textbook in teaching about the war, and U.S. history more broadly. Teachers are digging directly into primary sources and harnessing technology, all in an attempt to help students better understand the past and bring it to life. Doing so may be especially important with the Civil War,…

  9. Finding radiant-energy sources

    NASA Technical Reports Server (NTRS)

    Schaffer, G. J.

    1978-01-01

    Antenna is scanned in orthogonal directions to pinpoint interfering sources. Satellite system locates ground-based microwave transmitter to accuracy of about 100 miles. When data on misalinement of satellite antenna boresight are used to correct antenna pointing, accuracy is improved to better than 70 miles.

  10. National Synchrotron Light Source II

    ScienceCinema

    Steve Dierker

    2016-07-12

    The National Synchrotron Light Source II (NSLS-II) at the U.S. Department of Energy's Brookhaven National Laboratory is a proposed new state-of-the-art medium energy storage ring designed to deliver world-leading brightness and flux with top-off operation

  11. Alternative Sources of Student Financing.

    ERIC Educational Resources Information Center

    Cross, Dolores E.

    Financial barriers to college attendance that affect women, minorities, low-income, and other nontraditional students are identified, along with alternative sources of student financial aid. Research has suggested that financially-independent students are most vulnerable to fluctuations in aid, and tend to have low incomes, be minority members or…

  12. THE OPEN SOURCING OF EPANET

    EPA Science Inventory

    A proposal was made at the 2009 EWRI Congress in Kansas City, MO to establish an Open Source Project (OSP) for the widely used EPANET pipe network analysis program. This would be an ongoing collaborative effort among a group of geographically dispersed advisors and developers, wo...

  13. Image Makers: Reporters or Sources.

    ERIC Educational Resources Information Center

    Petruzzello, Marion C.

    To explore how news sources are used by media to create a social image of women during key suffrage events of 1858, 1920, and 1970, the front page stories of the "New York Times" were reviewed for 1 week prior to and 1 week following each of these events: May 14, 1858, the Eighth National Women's Rights Convention in New York City;…

  14. National Synchrotron Light Source II

    SciTech Connect

    Steve Dierker

    2008-03-12

    The National Synchrotron Light Source II (NSLS-II) at the U.S. Department of Energy's Brookhaven National Laboratory is a proposed new state-of-the-art medium energy storage ring designed to deliver world-leading brightness and flux with top-off operation

  15. Guam and Micronesia Reference Sources.

    ERIC Educational Resources Information Center

    Goetzfridt, Nicholas J.; Goniwiecha, Mark C.

    1993-01-01

    This article lists reference sources for studying Guam and Micronesia. The entries are arranged alphabetically by main entry within each section in the categories of: (1) bibliographical works; (2) travel and guide books; (3) handbooks and surveys; (4) dictionaries; (5) yearbooks; (6) periodical and newspaper publications; and (7) audiovisual…

  16. SOURCE MANAGEMENT AND CONTROL TECHNOLOGIES

    EPA Science Inventory

    The options for pollution abatement in WWF can be implemented at the source by land management and pollution prevention techniques, in the collection system, offline by storage, or in a treatment plant. An integrated system that combines prevention, control, and treatment has of...

  17. Information Sources on Rural Recycling.

    ERIC Educational Resources Information Center

    Notess, Greg; Kuske, Jodee

    1992-01-01

    Provides resources for rural recycling operations with the principle aim of assisting rural government officials, planners, residents, and educators to encourage recycling as an integral part of an individual's or community's solid waste management plan. Sources range from bibliographies, directories, and government documents to case studies. (49…

  18. Alternative nitrogen sources for cotton

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Several alternative nitrogen (N) sources, rates of N, and amendments were evaluated at Prattville, Alabama, on cotton in 2008. Nitrogen rates reported are for sidedress application only. Dry urea produced the highest yield, averaging 1100 pounds lint per acre. Ammonia volatilization was measured fr...

  19. Guide to Sources: Advertising. Revised.

    ERIC Educational Resources Information Center

    White, Lucinda M.

    This guide is designed to introduce the student to some of the major sources of advertising information available in the Fogler Library at the University of Maine. A brief description and exploration of the card catalog, Library of Congress Subject Headings, Library of Congress Classification System, and the Dewey Decimal System are included. In…

  20. MICROBIAL SOURCE TRACKING GUIDE DOCUMENT

    EPA Science Inventory

    Approximately 13% of surface waters in the United States do not meet designated use criteria as determined by high densities of fecal indicator bacteria. Although some of the contamination is attributed to point sources such as confined animal feeding operation (CAFO) and wastew...

  1. The Chandra Source Catalog: User Interface

    NASA Astrophysics Data System (ADS)

    Bonaventura, Nina; Evans, I. N.; Harbo, P. N.; Rots, A. H.; Tibbetts, M. S.; Van Stone, D. W.; Zografou, P.; Anderson, C. S.; Chen, J. C.; Davis, J. E.; Doe, S. M.; Evans, J. D.; Fabbiano, G.; Galle, E.; Gibbs, D. G.; Glotfelty, K. J.; Grier, J. D.; Hain, R.; Hall, D. M.; He, X.; Houck, J. C.; Karovska, M.; Lauer, J.; McCollough, M. L.; McDowell, J. C.; Miller, J. B.; Mitschang, A. W.; Morgan, D. L.; Nichols, J. S.; Nowak, M. A.; Plummer, D. A.; Primini, F. A.; Refsdal, B. L.; Siemiginowska, A. L.; Sundheim, B. A.; Winkelman, S. L.

    2009-01-01

    The Chandra Source Catalog (CSC) is the definitive catalog of all X-ray sources detected by Chandra. The CSC is presented to the user in two tables: the Master Chandra Source Table and the Table of Individual Source Observations. Each distinct X-ray source identified in the CSC is represented by a single master source entry and one or more individual source entries. If a source is unaffected by confusion and pile-up in multiple observations, the individual source observations are merged to produce a master source. In each table, a row represents a source, and each column a quantity that is officially part of the catalog. The CSC contains positions and multi-band fluxes for the sources, as well as derived spatial, spectral, and temporal source properties. The CSC also includes associated source region and full-field data products for each source, including images, photon event lists, light curves, and spectra. The master source properties represent the best estimates of the properties of a source, and are presented in the following categories: Position and Position Errors, Source Flags, Source Extent and Errors, Source Fluxes, Source Significance, Spectral Properties, and Source Variability. The CSC Data Access GUI provides direct access to the source properties and data products contained in the catalog. The user may query the catalog database via a web-style search or an SQL command-line query. Each query returns a table of source properties, along with the option to browse and download associated data products. The GUI is designed to run in a web browser with Java version 1.5 or higher, and may be accessed via a link on the CSC website homepage (http://cxc.harvard.edu/csc/). As an alternative to the GUI, the contents of the CSC may be accessed directly through a URL, using the command-line tool, cURL. Support: NASA contract NAS8-03060 (CXC).

  2. Miniaturized cathodic arc plasma source

    DOEpatents

    Anders, Andre; MacGill, Robert A.

    2003-04-15

    A cathodic arc plasma source has an anode formed of a plurality of spaced baffles which extend beyond the active cathode surface of the cathode. With the open baffle structure of the anode, most macroparticles pass through the gaps between the baffles and reflect off the baffles out of the plasma stream that enters a filter. Thus the anode not only has an electrical function but serves as a prefilter. The cathode has a small diameter, e.g. a rod of about 1/4 inch (6.25 mm) diameter. Thus the plasma source output is well localized, even with cathode spot movement which is limited in area, so that it effectively couples into a miniaturized filter. With a small area cathode, the material eroded from the cathode needs to be replaced to maintain plasma production. Therefore, the source includes a cathode advancement or feed mechanism coupled to cathode rod. The cathode also requires a cooling mechanism. The movable cathode rod is housed in a cooled metal shield or tube which serves as both a current conductor, thus reducing ohmic heat produced in the cathode, and as the heat sink for heat generated at or near the cathode. Cooling of the cathode housing tube is done by contact with coolant at a place remote from the active cathode surface. The source is operated in pulsed mode at relatively high currents, about 1 kA. The high arc current can also be used to operate the magnetic filter. A cathodic arc plasma deposition system using this source can be used for the deposition of ultrathin amorphous hard carbon (a-C) films for the magnetic storage industry.

  3. The Advanced Neutron Source liquid deuterium cold source

    SciTech Connect

    Lucas, A.T.

    1995-08-01

    The Advanced Neutron Source will employ two cold sources to moderate neutrons to low energy (<10 meV). The cold neutrons produced are then passed through beam guides to various experiment stations. Each cold source moderator is a sphere of 410-mm internal diameter. The moderator material is liquid deuterium flowing at a rate of 1 kg/s and maintained at subcooled temperatures at all points of the circuit, to prevent boiling. Nuclear beat deposited within the liquid deuterium and its containment structure totals more than 30 kW. All of this heat is removed by the liquid deuterium, which raises its temperature by 5 K. The liquid prime mover is a cryogenic circulator that is situated in the return leg of the flow loop. This arrangement minimizes the heat added to the liquid between the heat exchanger and the moderator vessel, allowing the moderator to be operated at the minimum practical temperature. This report describes the latest thinking at the time of project termination. It also includes the status of various systems at that time and outlines anticipated directions in which the design would have progressed. In this regard, some detail differences between this report and official design documents reflect ideas that were not approved at the time of closure but are considered noteworthy.

  4. Illinois' nonpoint source management program

    SciTech Connect

    Not Available

    1994-07-01

    The Illinois Nonpoint Source (NPS) Management Program (Program) describes the statewide authorities that give the Illinois Environmental Protection Agency (IEPA) responsibility to develop and implement this Program. It provides a brief summary of the results of the States' NPS assessment as reported in the Illinois Water Quality Report. Included are eleven sections correlated to NPS pollution sources, or to an area of water pollution protection initiatives. These sections outline goals and objectives to be implemented in Illinois to abate NPS pollution, when possible the sections include a descriptive narrative. Included in the Program, is the process or mechanism which Illinois uses to prioritize and fund future projects. Finally, this Program identifies the federal programs that the IEPA currently reviews for consistency with statewide goals and objectives. Revisions to the Program will be made in accordance with state and federal program changes and as needed.

  5. X-ray lithography source

    DOEpatents

    Piestrup, Melvin A.; Boyers, David G.; Pincus, Cary

    1991-01-01

    A high-intensity, inexpensive X-ray source for X-ray lithography for the production of integrated circuits. Foil stacks are bombarded with a high-energy electron beam of 25 to 250 MeV to produce a flux of soft X-rays of 500 eV to 3 keV. Methods of increasing the total X-ray power and making the cross section of the X-ray beam uniform are described. Methods of obtaining the desired X-ray-beam field size, optimum frequency spectrum and elminating the neutron flux are all described. A method of obtaining a plurality of station operation is also described which makes the process more efficient and economical. The satisfying of these issues makes transition radiation an exellent moderate-priced X-ray source for lithography.

  6. HIMAC PIG ion source development

    NASA Astrophysics Data System (ADS)

    Yamada, T.; Sato, Y.; Ogawa, H.; Kimura, T.

    1989-02-01

    The HIMAC (Heavy-Ion Medical Accelerator in Chiba) project is in progress. Necessary characteristics for the HIMAC ion source are high current ( 130-630 μA with a q/A of{1}/{7}) from He to Ar, good stability, long life and easy maintenance. To attain these characteristics, an indirectly heated PIG ion source test bench has been designed and constructed since 1985. A low-energy beam transport line has also been installed in order to test the beam quality and the matching condition with an RFQ linac (8-800 keV/u). For N, Ne and Ar, preliminary experiments have been carried out on the arc characteristics, ion extraction and charge spectra since 1987. The radial emittance has also been measured and is 150 π mm mrad for a 40 μA Ar 3+ beam (0.64 keV/u).

  7. Overview of terahertz radiation sources.

    SciTech Connect

    Gallerano, G. P.; Biedron, S. G.; Energy Systems; ENEA

    2004-01-01

    Although terahertz (THz) radiation was first observed about hundred years ago, the corresponding portion of the electromagnetic spectrum has been for long time considered a rather poorly explored region at the boundary between the microwaves and the infrared. This situation has changed during the past ten years with the rapid development of coherent THz sources, such as solid state oscillators, quantum cascade lasers, optically pumped solid state devices and novel free electron devices, which have in turn stimulated a wide variety of applications from material science to telecommunications, from biology to biomedicine. For a comprehensive review of THz technology the reader is addressed to a recent paper by P. Siegel. In this paper we focus on the development and perspectives of THz radiation sources.

  8. X-ray lithography source

    DOEpatents

    Piestrup, M.A.; Boyers, D.G.; Pincus, C.

    1991-12-31

    A high-intensity, inexpensive X-ray source for X-ray lithography for the production of integrated circuits is disclosed. Foil stacks are bombarded with a high-energy electron beam of 25 to 250 MeV to produce a flux of soft X-rays of 500 eV to 3 keV. Methods of increasing the total X-ray power and making the cross section of the X-ray beam uniform are described. Methods of obtaining the desired X-ray-beam field size, optimum frequency spectrum and eliminating the neutron flux are all described. A method of obtaining a plurality of station operation is also described which makes the process more efficient and economical. The satisfying of these issues makes transition radiation an excellent moderate-priced X-ray source for lithography. 26 figures.

  9. Crowd-Sourced Program Verification

    DTIC Science & Technology

    2012-12-01

    S / ROBERT L. KAMINSKI WARREN H. DEBANY, JR. Work Unit Manager Technical Advisor, Information Exploitation & Operations...Arlington, VA 22202-4302, and to the Office of Management and Budget, Paperwork Reduction Project (0704-0188) Washington, DC 20503. PLEASE DO NOT RETURN...investigation, the contractor constructed a prototype of a crowd-sourced verification system that takes as input a given program and produces as output a

  10. Plasma sources for spacecraft neutralization

    NASA Technical Reports Server (NTRS)

    Davis, V. A.; Katz, I.; Mandell, M. J.

    1990-01-01

    The principles of the operation of plasma sources for the neutralization of the surface of a spacecraft traveling in the presence of hot plasma are discussed with special attention given to the hollow-cathode-based plasma contactors. Techiques are developed that allow the calculation of the potentials and particle densities in the near environment of a hollow cathode plasma contactor in both the test tank and the LEO environment. The techniques and codes were validated by comparison of calculated and measured results.

  11. Multi-Source Image Analysis.

    DTIC Science & Technology

    1979-12-01

    three sensor systems, but at some test sites only one or two types were utilized. Sensor characteristics were evaluated in relationship to the targets...Multi-source image analysis is an evaluation of remote sensor imagery for military geographic information. The imagery is confined to radar, thermal...heating affect a TIR scanner’s recorded temperature, careful image evaluation can be used to extract valuable military geographic information

  12. Compact High Power THz Source

    SciTech Connect

    Geoffrey Krafft

    2003-08-01

    In this paper a new type of THz radiation source, based on recirculating an electron beam through a high gradient superconducting radio frequency cavity, and using this beam to drive a standard electromagnetic undulator, is discussed. Because the beam is recirculated, short bunches may be produced that radiate coherently in the undulator, yielding high average THz power for relatively low average beam power. Deceleration from the coherent emission, and the detuning it causes is discussed.

  13. Bremsstrahlung from cylindrical beta sources.

    NASA Technical Reports Server (NTRS)

    Harris, D. W.; Silverman, J.

    1972-01-01

    Refined experimental measurements of the bremsstrahlung number and energy fluxes from thick cylindrical sources of several nuclides are presented, dose rates calculated from experimental energy fluxes are compared with theoretical results based on Wyard's thick-target approximation, and experiments are correlated with both thick- and thin-target bremsstrahlung theory to obtain accurate values of bremsstrahlung yields. The data presented should prove useful for the design of radioisotope power supplies, particularly those used in spacecraft and in biological applications.

  14. Error Sources in Asteroid Astrometry

    NASA Technical Reports Server (NTRS)

    Owen, William M., Jr.

    2000-01-01

    Asteroid astrometry, like any other scientific measurement process, is subject to both random and systematic errors, not all of which are under the observer's control. To design an astrometric observing program or to improve an existing one requires knowledge of the various sources of error, how different errors affect one's results, and how various errors may be minimized by careful observation or data reduction techniques.

  15. Poverty - A Source of Conflict,

    DTIC Science & Technology

    1980-08-25

    contend that poor coun- tries are likely to attack richer ones for the spoils of war, but rather that poverty is a breeding ground for instability. He...Studies Institute v POVERTY - A SOURCE OF CONFLICT The rich get richer; the poor get poorer. As this rule has applied to individuals, it has apparently...problems. These problems resulting from poverty create a dangerous threat to the stability of the world. This does not mean that poor countries will

  16. The Open Source Hardening Project

    DTIC Science & Technology

    2009-07-01

    code on a recurring basis from more than 250 open popular source projects such as Firefox, Linux, and PHP . This represents 14,238 individual project...gcc) greatly simplifies debugging and error reporting. For exam- ple, all COREUTILS bugs were confirmed and fixed within two days and versions of the...making system calls fail outside of KLEE — we built a simple utility that uses the ptrace debugging interface to skip the system calls that were

  17. Electron sources in Saturn's magnetosphere

    NASA Astrophysics Data System (ADS)

    Rymer, A. M.; Mauk, B. H.; Hill, T. W.; Paranicas, C.; André, N.; Sittler, E. C.; Mitchell, D. G.; Smith, H. T.; Johnson, R. E.; Coates, A. J.; Young, D. T.; Bolton, S. J.; Thomsen, M. F.; Dougherty, M. K.

    2007-02-01

    We investigate the sources of two different electron components in Saturn's inner magnetosphere (5 < L < 12 Rs) by performing phase space density (f(v)) analyses of electron measurements made by the Cassini CAPS instrument (1 eV to 28 keV). Because pitch angle distributions indicate that the traditional single particle invariants of gyration and bounce are not appropriate, we use a formulation of the isotropic invariant derived by Wolf (1983) and Schulz (1998) and show that it is similar in functional form to the first adiabatic invariant. Our f(v) analyses confirm that the cooler electrons (<100 eV) have a source in the inner magnetosphere and are likely products of neutral ionization processes in Saturn's neutral cloud. The mystery is how the electrons are heated to energies comparable to the proton thermal energy (which is approximately equal to the proton pickup energy), a process that reveals itself as a source of electrons at given invariant values in our f(v) analyses. We show that Coulomb collisions provide a viable mechanism to achieve the near equipartition of ion and electron energies in the time available before particles are lost from the region. We find that the source of the hotter electron component (>100 eV) is Saturn's middle or outer magnetosphere, perhaps transported to the inner magnetosphere by radial diffusion regulated by interchange-like injections. Hot electrons undergo heavy losses inside L ~ 6 and the distance to which the hot electron component penetrates into the neutral cloud is energy-dependent, with the coolest fraction of the hot plasma penetrating to the lowest L-shells. This can arise through energy-dependent radial transport during the interchange process and/or loss through the planetary loss cone.

  18. Source Contributions at Regional Distances

    DTIC Science & Technology

    1991-05-14

    turbidity, and source excitation can in some instances be recovered. High frequency RSTN data with bandwidths as high as 7 Hz are analyzed. The coda Q values...observations used in this study are seismograms from Nevada Test Site (NTS) nuclear explosions and earthquakes in the California/Gulf of California region. The...Yield estimates of Nevada Test Site explosions obtained from seismic Lg waves, J.Geophys.Res., 91, 2137-2151 Nuttli, O.W. (1988): Lg magnitudes and yield

  19. Ethanol: A Strategic Energy Source?

    DTIC Science & Technology

    2009-05-04

    REPORT DATE (DD-MM-YYYY) 04-05-2009 2. REPORT TYPE Program Research Paper 3 . DATES COVERED (From - To) 4. TITLE AND SUBTITLE 5a. CONTRACT NUMBER...radical terrorists richer.” 3 This research project examines the viability of ethanol as an alternative fuel source. It will identify whether an ethanol...Japan in 1941 went to war to secure its energy supplies. The United States must 3 prepare for these shortages if we are to maintain our economic

  20. Exploiting dual otoacoustic emission sources

    NASA Astrophysics Data System (ADS)

    Abdala, Carolina; Kalluri, Radha

    2015-12-01

    Two distinct processes generate otoacoustic emissions (OAEs). Reflection-source emissions, here recorded as stimulus frequency OAEs, are optimally informative at low sound levels and are more sensitive to slight hearing loss; they have been linked to cochlear amplifier gain and tuning. Distortion-source emissions are strongest at moderate-high sound levels and persist despite mild hearing loss; they likely originate in the nonlinear process of hair cell transduction. In this preliminary study, we exploit the unique features of each by generating a combined reflection-distortion OAE profile in normal hearing and hearing-impaired ears. Distortion-product (DP) and stimulus-frequency (SF) OAEs were recorded over a broad range of stimulus levels and frequencies. Individual I/O and transfer functions were generated for both emission types in each ear, and OAE peak strength, compression threshold, and rate of compression were calculated. These combined SFOAE and DPOAE features in normal and hearing-impaired ears may provide a potentially informative and novel index of hearing loss. This is an initial step toward utilizing OAE source in characterizing cochlear function and dysfunction.

  1. Dislocation sources in ordered intermetallics

    SciTech Connect

    Yoo, M.H.; Appel, F.; Wagner, R.; Mecking, H.

    1996-09-01

    An overview on the current understanding of dislocation sources and multiplication mechanisms is made for ordered intermetallic alloys of the L1{sub 2}, B2, and D0{sub 19} structures. In L1{sub 2} alloys, a large disparity of edge/screw segments in their relative mobility reduces the efficiency of a Frank-Read Type multiplication mechanism. In Fe-40%Al of the B2 structure, a variety of dislocation sources are available for <111> slip, including ones resulting from condensation of thermal vacancies. In NiAl with the relatively high APB energy, <100> dislocations may result from the dislocation decomposition reactions, the prismatic punching out from inclusion particles, and/or steps and coated layers of the surface. Internal interfaces often provide sites for dislocation multiplication, e.g., grain boundaries, sub-boundaries in Ni{sub 3}Ga, NiAl and Ti{sub 3}Al, and antiphase domain boundaries in Ti{sub 3}Al. As for the crack tip as a dislocation source, extended SISFs trailed by super-Shockley partials emanating form the cracks in Ni{sub 3}Al and Co{sub 3}Ti are discussed in view of a possible toughening mechanism.

  2. Lasers and Coherent Light Sources

    NASA Astrophysics Data System (ADS)

    Svelto, Orazio; Longhi, Stefano; Della Valle, Giuseppe; Huber, Günter; Kück, Stefan; Pollnau, Markus; Hillmer, Hartmut; Kusserow, Thomas; Engelbrecht, Rainer; Rohlfing (deceased), Frank; Kaiser, Jeffrey; Malz, Ralf; Marowsky, Gerd; Mann, Klaus; Simon, Peter; Rhodes, Charles K.; Duarte, Frank J.; Borsutzky, Annette; L'Huillier, Johannes A.; Sigrist, Markus W.; Wächter, Helen; Saldin, Evgeny; Schneidmiller, Evgeny; Yurkov, Mikhail; Sauerbrey, Roland; Hein, Joachim; Gianella, Michele; Helmcke, Jürgen; Midorikawa, Katsumi; Riehle, Fritz; Steinberg, Steffen; Brand, Hans

    This chapter describes lasers and other sources of coherent light that operate in a wide wavelength range. First, the general principles for the generation of coherent continuous-wave and pulsed radiation are treated including the interaction of radiation with matter, the properties of optical resonators and their modes as well as such processes as Q-switching and mode-locking. The general introduction is followed by sections on numerous types of lasers, the emphasis being on today's most important sources of coherent light, in particular on solid-state lasers and several types of gas lasers. An important part of the chapter is devoted to the generation of coherent radiation coherent radiation by nonlinear processes with optical parametric oscillators, difference- and sum-frequency generation, and high-order harmonics. Radiation in the extended ultraviolet (EUV) and x-ray ranges can be generated by free electron lasers (FEL) and advanced x-ray sources. Ultrahigh light intensities up to 1021 W/cm2 open the door to studies of relativistic laser-matter interaction and laser particle acceleration. The chapter closes with a section on laser stabilization.

  3. Lasers and Coherent Light Sources

    NASA Astrophysics Data System (ADS)

    Svelto, Orazio; Longhi, Stefano; Valle, Giuseppe; Kück, Stefan; Huber, Günter; Pollnau, Markus; Hillmer, Hartmut; Hansmann, Stefan; Engelbrecht, Rainer; Brand, Hans; Kaiser, Jeffrey; Peterson, Alan; Malz, Ralf; Steinberg, Steffen; Marowsky, Gerd; Brinkmann, Uwe; Lo, Dennis; Borsutzky, Annette; Wächter, Helen; Sigrist, Markus; Saldin, Evgeny; Schneidmiller, Evgeny; Yurkov, Mikhail; Midorikawa, Katsumi; Hein, Joachim; Sauerbrey, Roland; Helmcke, Jürgen

    This chapter describes lasers and other sources of coherent light that operate in a wide wavelength range. First, the general principles for the generation of coherent continuous-wave and pulsed radiation are treated including the interaction of radiation with matter, the properties of optical resonators and their modes as well as such processes as Q-switching and mode-locking. The general introduction is followed by sections on numerous types of lasers, the emphasis being on today's most important sources of coherent light, in particular on solid-state lasers and several types of gas lasers. An important part of the chapter is devoted to the generation of coherent radiation by nonlinear processes with optical parametric oscillators, difference- and sum-frequency generation, and high-order harmonics. Radiation in the extended ultraviolet (EUV) and X-ray ranges can be generated by free electron lasers (FEL) and advanced X-ray sources. Ultrahigh light intensities up to 1021 W/cm2 open the door to studies of relativistic laser-matter interaction and laser particle acceleration. The chapter closes with a section on laser stabilization.

  4. Kernel current source density method.

    PubMed

    Potworowski, Jan; Jakuczun, Wit; Lȩski, Szymon; Wójcik, Daniel

    2012-02-01

    Local field potentials (LFP), the low-frequency part of extracellular electrical recordings, are a measure of the neural activity reflecting dendritic processing of synaptic inputs to neuronal populations. To localize synaptic dynamics, it is convenient, whenever possible, to estimate the density of transmembrane current sources (CSD) generating the LFP. In this work, we propose a new framework, the kernel current source density method (kCSD), for nonparametric estimation of CSD from LFP recorded from arbitrarily distributed electrodes using kernel methods. We test specific implementations of this framework on model data measured with one-, two-, and three-dimensional multielectrode setups. We compare these methods with the traditional approach through numerical approximation of the Laplacian and with the recently developed inverse current source density methods (iCSD). We show that iCSD is a special case of kCSD. The proposed method opens up new experimental possibilities for CSD analysis from existing or new recordings on arbitrarily distributed electrodes (not necessarily on a grid), which can be obtained in extracellular recordings of single unit activity with multiple electrodes.

  5. ION SOURCE FOR A CALUTRON

    DOEpatents

    Backus, J.G.

    1957-12-24

    This patent relates to ion sources and more particularly describes an ion source for a calutron which has the advantage of efficient production of an ion beam and long operation time without recharging. The source comprises an arc block provided with an arc chamber connected to a plurality of series-connected charge chambers and means for heating the charge within the chambers. A cathode is disposed at one end of the arc chamber and enclosed hy a vapor tight housing to protect the cathode. The arc discharge is set up between the cathode and the block due to a difference in potentials placed on these parts, and a magnetic field is aligned with the arc discharge. Cooling of the arc block is accomplished by passing coolant through a hollow stem secured at one end to the block and rotatably mounted at the other end through the wall of the calutron. The ions are removed through a slit in the arc chamber by accelerating electrodes.

  6. Uncertainty in source partitioning using stable isotopes.

    PubMed

    Phillips, D L; Gregg, J W

    2001-04-01

    Stable isotope analyses are often used to quantify the contribution of multiple sources to a mixture, such as proportions of food sources in an animal's diet, or C3 and C4 plant inputs to soil organic carbon. Linear mixing models can be used to partition two sources with a single isotopic signature (e.g., δ(13)C) or three sources with a second isotopic signature (e.g., δ(15)N). Although variability of source and mixture signatures is often reported, confidence interval calculations for source proportions typically use only the mixture variability. We provide examples showing that omission of source variability can lead to underestimation of the variability of source proportion estimates. For both two- and three-source mixing models, we present formulas for calculating variances, standard errors (SE), and confidence intervals for source proportion estimates that account for the observed variability in the isotopic signatures for the sources as well as the mixture. We then performed sensitivity analyses to assess the relative importance of: (1) the isotopic signature difference between the sources, (2) isotopic signature standard deviations (SD) in the source and mixture populations, (3) sample size, (4) analytical SD, and (5) the evenness of the source proportions, for determining the variability (SE) of source proportion estimates. The proportion SEs varied inversely with the signature difference between sources, so doubling the source difference from 2‰ to 4‰ reduced the SEs by half. Source and mixture signature SDs had a substantial linear effect on source proportion SEs. However, the population variability of the sources and the mixture are fixed and the sampling error component can be changed only by increasing sample size. Source proportion SEs varied inversely with the square root of sample size, so an increase from 1 to 4 samples per population cut the SE in half. Analytical SD had little effect over the range examined since it was generally

  7. 48 CFR 13.102 - Source list.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 48 Federal Acquisition Regulations System 1 2011-10-01 2011-10-01 false Source list. 13.102... AND CONTRACT TYPES SIMPLIFIED ACQUISITION PROCEDURES Procedures 13.102 Source list. (a) Contracting... as their primary sources of vendor information. Offices maintaining additional vendor source files...

  8. 21 CFR 640.60 - Source Plasma.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 7 2010-04-01 2010-04-01 false Source Plasma. 640.60 Section 640.60 Food and... ADDITIONAL STANDARDS FOR HUMAN BLOOD AND BLOOD PRODUCTS Source Plasma § 640.60 Source Plasma. The proper name of the product shall be Source Plasma. The product is defined as the fluid portion of human...

  9. 21 CFR 640.60 - Source Plasma.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 7 2011-04-01 2010-04-01 true Source Plasma. 640.60 Section 640.60 Food and Drugs... STANDARDS FOR HUMAN BLOOD AND BLOOD PRODUCTS Source Plasma § 640.60 Source Plasma. The proper name of the product shall be Source Plasma. The product is defined as the fluid portion of human blood collected...

  10. 21 CFR 640.60 - Source Plasma.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 7 2012-04-01 2012-04-01 false Source Plasma. 640.60 Section 640.60 Food and... ADDITIONAL STANDARDS FOR HUMAN BLOOD AND BLOOD PRODUCTS Source Plasma § 640.60 Source Plasma. The proper name of the product shall be Source Plasma. The product is defined as the fluid portion of human...

  11. 21 CFR 640.60 - Source Plasma.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 7 2013-04-01 2013-04-01 false Source Plasma. 640.60 Section 640.60 Food and... ADDITIONAL STANDARDS FOR HUMAN BLOOD AND BLOOD PRODUCTS Source Plasma § 640.60 Source Plasma. The proper name of the product shall be Source Plasma. The product is defined as the fluid portion of human...

  12. 21 CFR 640.60 - Source Plasma.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 7 2014-04-01 2014-04-01 false Source Plasma. 640.60 Section 640.60 Food and... ADDITIONAL STANDARDS FOR HUMAN BLOOD AND BLOOD PRODUCTS Source Plasma § 640.60 Source Plasma. The proper name of the product shall be Source Plasma. The product is defined as the fluid portion of human...

  13. 48 CFR 13.102 - Source list.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... as their primary sources of vendor information. Offices maintaining additional vendor source files or... 48 Federal Acquisition Regulations System 1 2010-10-01 2010-10-01 false Source list. 13.102... AND CONTRACT TYPES SIMPLIFIED ACQUISITION PROCEDURES Procedures 13.102 Source list. (a)...

  14. S and Ku band frequency source development

    NASA Technical Reports Server (NTRS)

    1980-01-01

    The results of the two part S- and Ku-band source development program are described. The S- and Ku-band sources were designed, fabricated, and evaluated. A high performance S- and Ku-band microwave signal source using state-of-the-art oscillator and microwave source technology was developed.

  15. On the output of acoustical sources

    NASA Technical Reports Server (NTRS)

    Levine, H.

    1979-01-01

    Contents: (1) a theoretical basis for local power calculation; (2) source radiation in the presence of a half-plane; (3) radiation from a line source near an edge at which a Kutta condition holds; (4) radiation by a point source above a plane independence boundary; and (5) power output of a point source in a uniform flow.

  16. Syndrome source coding and its universal generalization

    NASA Technical Reports Server (NTRS)

    Ancheta, T. C., Jr.

    1975-01-01

    A method of using error-correcting codes to obtain data compression, called syndrome-source-coding, is described in which the source sequence is treated as an error pattern whose syndrome forms the compressed data. It is shown that syndrome-source-coding can achieve arbitrarily small distortion with the number of compressed digits per source digit arbitrarily close to the entropy of a binary memoryless source. A universal generalization of syndrome-source-coding is formulated which provides robustly-effective, distortionless, coding of source ensembles.

  17. Polarized Sources, Targets and Polarimetry

    NASA Astrophysics Data System (ADS)

    Ciullo, Guiseppe; Contalbrigo, Marco; Lenisa, P.

    2011-01-01

    Remarks on the history of workshops on "spin tools" / E. Steffens -- Polarized proton beams in RHIC / A. Zelenski -- The COSY/Julich polarized H[symbol] and D[symbol] ion source / O. Felden -- The new source of polarized ions for the JINR accelerator complex / V. V. Fimushkin -- Resonance effects in nuclear dichroism - an inexpensive source of tensor-polarized deuterons / H. Seyfarth -- Polarized electrons and positrons at the MESA accelerator / K. Aulenbacher -- Status report of the Darmstadt polarized electron injector / Y. Poltoratska -- The Mott polarimeter at MAMI / V. Tioukine -- Proton polarimetry at the relativistic heavy ion collider / Y. Makdisi -- Polarisation and polarimetry at HERA / B. Sobloher -- Polarisation measurement at the ILC with a Compton polarimeter / C. Bartels -- Time evolution of ground motion-dependent depolarisation at linear colliders / A. Hartin -- Electron beam polarimetry at low energies and its applications / R. Barday -- Polarized solid targets: recent progress and future prospects / C. D. Keith -- HD gas distillation and analysis for HD frozen spin targets / A. D'Angelo -- Electron spin resonance study of hydrogen and alkyl free radicals trapped in solid hydrogen aimed for dynamic nuclear polarization of solid HD / T. Kumada -- Change of ultrafast nuclear-spin polarization upon photoionization by a short laser pulse / T. Nakajima -- Radiation damage and recovery in polarized [symbol]NH[symbol] ammonia targets at Jefferson lab / J. D. Maxwell.Polarized solid proton target in low magnetic field and at high temperature / T. Uesaka -- Pulse structure dependence of the proton spin polarization rate / T. Kawahara -- Proton NMR in the large COMPASS [symbol]NH[symbol] target / J. Koivuniemi -- DNP with TEMPO and trityl radicals in deuterated polystyrene / L. Wang -- The CLIC electron and positron polarized sources / L. Rinolfi -- Status of high intensity polarized electron gun at MIT-Bates / E. Tsentalovich -- Target section for spin

  18. Sources of Underwater Sound and Their Characterization.

    PubMed

    Ainslie, Michael A; de Jong, Christ A F

    2016-01-01

    Because of the history of sonar and sonar engineering, the concept of "source level" is widely used to characterize anthropogenic sound sources, but is it useful for sources other than sonar transmitters? The concept and applicability of source level are reviewed for sonar, air guns, explosions, ships, and pile drivers. International efforts toward the harmonization of the terminology for underwater sound and measurement procedures for underwater sound sources are summarized, with particular attention to the initiatives of the International Organization for Standardization.

  19. Status of the advanced neutron source. [Advanced Neutron Source Reactor

    SciTech Connect

    Hayter, J.B.

    1990-01-01

    Research reactors in the United States are becoming more and more outdated, at a time when neutron scattering is being recognized as an increasingly important technique in areas vital to the US scientific and technological future. The last US research reactor was constructed over 25 years ago, whereas new facilities have been built or are under construction in Japan, Russia and, especially, Western Europe, which now has a commanding lead in this important field. Concern over this situation in the early 1980's by a number of organizations, including the National Academy of Sciences, led to a recommendation that design work start urgently on an advanced US neutron research facility. This recommendation is realized in the Advanced Neutron Source Project. The centerpiece of the Advanced Neutron Source will be a new research reactor of unprecedented flux (>7.5 {times} 10{sup 19} m{sup {minus}2}{center dot}s{sup {minus}1}), equipped with a wide variety of state-of-the-art spectrometers and diffractometers on hot, thermal, and cold neutron beams. Very cold and ultracold neutron beams will also be provided for specialized experiments. This paper will discuss the current status of the design and the plans for scattering instrumentation. 5 refs.

  20. [Source data management in clinical researches].

    PubMed

    Ho, Effie; Yao, Chen; Zhang, Zi-bao; Liu, Yu-xiu

    2015-11-01

    Source data and its source documents are the foundation of clinical research. Proper source data management plays an essential role for compliance with regulatory and GCP requirements. Both paper and electronic source data co-exist in China. Due to the increasing use of electronic technology in pharmaceutical and health care industry, electronic data source becomes an upcoming trend with clear advantages. To face new opportunities and to ensure data integrity, quality and traceability from source data to regulatory submission, this document demonstrates important concepts, principles and best practices during managing source data. It includes but not limited to: (1) important concepts of source data (e.g., source data originator, source data elements, source data identifier for audit trail, etc.); (2) various modalities of source data collection in paper and electronic methods (e.g., paper CRF, EDC, Patient Report Outcomes/eCOA, etc.); (3) seven main principles recommended in the aspect of data collection, traceability, quality standards, access control, quality control, certified copy and security during source data management; (4) a life cycle from source data creation to obsolete is used as an example to illustrate consideration and implementation of source data management.

  1. Compact x-ray source and panel

    SciTech Connect

    Sampayon, Stephen E.

    2008-02-12

    A compact, self-contained x-ray source, and a compact x-ray source panel having a plurality of such x-ray sources arranged in a preferably broad-area pixelized array. Each x-ray source includes an electron source for producing an electron beam, an x-ray conversion target, and a multilayer insulator separating the electron source and the x-ray conversion target from each other. The multi-layer insulator preferably has a cylindrical configuration with a plurality of alternating insulator and conductor layers surrounding an acceleration channel leading from the electron source to the x-ray conversion target. A power source is connected to each x-ray source of the array to produce an accelerating gradient between the electron source and x-ray conversion target in any one or more of the x-ray sources independent of other x-ray sources in the array, so as to accelerate an electron beam towards the x-ray conversion target. The multilayer insulator enables relatively short separation distances between the electron source and the x-ray conversion target so that a thin panel is possible for compactness. This is due to the ability of the plurality of alternating insulator and conductor layers of the multilayer insulators to resist surface flashover when sufficiently high acceleration energies necessary for x-ray generation are supplied by the power source to the x-ray sources.

  2. The HYPE Open Source Community

    NASA Astrophysics Data System (ADS)

    Strömbäck, L.; Pers, C.; Isberg, K.; Nyström, K.; Arheimer, B.

    2013-12-01

    The Hydrological Predictions for the Environment (HYPE) model is a dynamic, semi-distributed, process-based, integrated catchment model. It uses well-known hydrological and nutrient transport concepts and can be applied for both small and large scale assessments of water resources and status. In the model, the landscape is divided into classes according to soil type, vegetation and altitude. The soil representation is stratified and can be divided in up to three layers. Water and substances are routed through the same flow paths and storages (snow, soil, groundwater, streams, rivers, lakes) considering turn-over and transformation on the way towards the sea. HYPE has been successfully used in many hydrological applications at SMHI. For Europe, we currently have three different models; The S-HYPE model for Sweden; The BALT-HYPE model for the Baltic Sea; and the E-HYPE model for the whole Europe. These models simulate hydrological conditions and nutrients for their respective areas and are used for characterization, forecasts, and scenario analyses. Model data can be downloaded from hypeweb.smhi.se. In addition, we provide models for the Arctic region, the Arab (Middle East and Northern Africa) region, India, the Niger River basin, the La Plata Basin. This demonstrates the applicability of the HYPE model for large scale modeling in different regions of the world. An important goal with our work is to make our data and tools available as open data and services. For this aim we created the HYPE Open Source Community (OSC) that makes the source code of HYPE available for anyone interested in further development of HYPE. The HYPE OSC (hype.sourceforge.net) is an open source initiative under the Lesser GNU Public License taken by SMHI to strengthen international collaboration in hydrological modeling and hydrological data production. The hypothesis is that more brains and more testing will result in better models and better code. The code is transparent and can be changed

  3. High Intensity Polarized Electron Sources

    SciTech Connect

    Poelker, M.; Adderley, P.; Brittian, J.; Clark, J.; Grames, J.; Hansknecht, J.; McCarter, J.; Stutzman, M. L.; Suleiman, R.; Surles-Law, K.

    2008-02-06

    During the 1990s, at numerous facilities world wide, extensive R and D devoted to constructing reliable GaAs photoguns helped ensure successful accelerator-based nuclear and high-energy physics programs using spin polarized electron beams. Today, polarized electron source technology is considered mature, with most GaAs photoguns meeting accelerator and experiment beam specifications in a relatively trouble-free manner. Proposals for new collider facilities however, require electron beams with parameters beyond today's state-of-the-art and serve to renew interest in conducting polarized electron source R and D. And at CEBAF/Jefferson Lab, there is an immediate pressing need to prepare for new experiments that require considerably more beam current than before. One experiment in particular - Q-weak, a parity violation experiment that will look for physics beyond the Standard Model--requires 180 uA average current at polarization >80% for a duration of one year, with run-averaged helicity correlated current asymmetry less than 0.1 ppm. Neighboring halls will continue taking beam during Q-weak, pushing the total average beam current from the gun beyond 300 uA. This workshop contribution describes R and D at Jefferson Lab, dedicated toward extending the operating current of polarized electron sources to meet the requirements of high current experiments at CEBAF and to better appreciate the technological challenges of new accelerators, particularly high average current machines like eRHIC that require at least 25 mA at high polarization.

  4. PERSPECTIVE: Dust, fertilization and sources

    NASA Astrophysics Data System (ADS)

    Remer, Lorraine A.

    2006-11-01

    fraction that arrives at another continent [2]. At the deposition end of the chain, it is still unclear how the limited minerals in the dust such as iron are released for uptake by organisms either on land or in the ocean. Not all dust deposited into oceans results in a phytoplankton bloom. The process requires a chemical pathway that mobilizes a fraction of the iron into soluble form. Meskhidze et al [3] show that phytoplankton blooms following dust transport from the Gobi desert in Asia into the Pacific ocean result in a phytoplankton bloom only if the dust is accompanied by high initial SO2-to-dust ratios, suggesting that sulfuric acid coatings on the dust particle mobilize the embedded iron in the dust for phytoplankton uptake. Quantifying transport, deposition and nutrient availability are the latter ends of a puzzle that must begin by identifying and quantifying dust emission at the sources. The emission process is complex at the microscale requiring the right conditions for saltation and bombardment, which makes identification and inclusion of sources in global transport models very difficult. The result is that estimates of annual global dust emissions range from 1000 to 3000 Tg per year [4]. Even as global estimates of dust emissions are uncertain, localizing the sources brings even greater uncertainty. It has been recognized for several years that dust sources are not uniformly distributed over the arid regions of the Earth, but are regulated to topographic lows associated with dried lake deposits [5]. Using aerosol information from satellites, a comprehensive map of the world's source regions shows sources localized to specific areas of the Earth's arid regions [6]. Still these maps suggest broad emission sources covering several degrees of latitude and longitude. In the paper by Koren and co-authors [7] appearing in this issue, one particular dust source, the Bodélé depression in Chad, is analyzed in detail. They find that the specific topography of the

  5. Populations of extragalactic radio sources

    NASA Astrophysics Data System (ADS)

    Wall, J. V.

    In the late 1950s and early 1960s, radio sky surveys were the center of an intense and public debate -- Big-Bang versus Steady-State cosmology -- the arguments revolving about source counts and statistical interpretations in the face of instrumental complications. The 1965 discovery of the microwave background took the fire from the debate, but left the momentum in place for large-area radio surveys at different frequencies, and for extensive identification/redshift-measurement programs. By the 1970s the data enabled us to start disentangling the different populations of extragalactic radio sources. We could refine our taxonomy, and we could view the possibility of delineating individual cosmic histories and evolutions. We could at least describe a goal to elucidate the birth-life-death cycles of the objects involved 1quasi-stellar objects (QSOs) and radio galaxies: together the 'active galactic nuclei' (AGNs)1 whose unaccountably prodigious energies somehow produce the beautifully aligned radio structures with which we are now familiar. One part of John Bolton's vision was to see how distorted a view of the AGN universe the original long-wavelength surveys provided. One legacy is thus the 'short-wavelength survey' for extragalactic radio sources, which has done so much to balance our picture of the radio sky. And indeed the legacy continues in the form of the immense sky surveys at present under way, complete with their sub-industries of radio-positioning and identification. From these, yet further results are emerging on spatial distribution and the skeleton structure of the universe. It is the purpose of this paper to outline something of this current view of the populations, their differences, similarities and unifying concepts.

  6. Multigamma-ray calibration sources

    SciTech Connect

    Meyer, R.A.; Massey, T.N.

    1983-05-01

    We have calibrated a self-consistent set of multigamma-ray standards using the automated multi-spectrometry ..gamma..-ray counting facility at LLNL's Nuclear Chemistry Division. Pure sources of long-lived activity were produced by mass separation and/or chemical purification. The sources were counted individually and in combination on several different calibrated spectrometer systems. These systems utilize various detectors ranging from small (x-ray) detectors to large volume high-purity Ge detectors. This has allowed the use of the most ideal individual detector-efficiency characteristics for the determination of the relative ..gamma..-ray intensities. Precise energy measurements, reported earlier (Meyer, 1976) have been performed by an independent method. Both the energy and ..gamma..-ray-emission probabilities determined compare well with independently established values such as the recent ICRM intercomparison of /sup 152/Eu. We discuss our investigations aimed at resolving the shape of the efficiency response function up to 10 MeV for large volume Ge(Li) and high-purity Ge detectors. Recent results on the ..gamma..-ray-emission probabilities per decay for /sup 149/Gd and /sup 168/Tm multigamma-ray sources are discussed. For /sup 168/Tm, we deduce a 0.01% ..beta../sup -/ branch to the 87.73-keV level in /sup 168/Yb rather than the previous value which was a factor of 200 greater. In addition, we describe current cooperative efforts aimed at establishing a consistent set of data for short-lived fission products. Included are recent measurements on the bromine fission products with ..gamma.. rays up to 7 MeV.

  7. PSD Requirements for Reactivated Sources

    EPA Pesticide Factsheets

    This document may be of assistance in applying the New Source Review (NSR) air permitting regulations including the Prevention of Significant Deterioration (PSD) requirements. This document is part of the NSR Policy and Guidance Database. Some documents in the database are a scanned or retyped version of a paper photocopy of the original. Although we have taken considerable effort to quality assure the documents, some may contain typographical errors. Contact the office that issued the document if you need a copy of the original.

  8. Antimatter as an Energy Source

    SciTech Connect

    Jackson, Gerald P.

    2009-03-16

    Antiprotons and positrons are constantly generated in space, and periodically manufactured by humans here on Earth. Harvesting of these particles in space and forming stable antimatter atoms and molecules would create a significant energy source for power and propulsion. Though dedicated fabrication of these particles on Earth consumes much more energy than could be liberated upon annihilation, manufactured antimatter represents a high-density energy storage mechanism well suited for spacecraft power and propulsion. In this paper the creation, storage, and utilization of antimatter is introduced. Specific examples of electrical energy generation and deep-space propulsion based on antimatter are also reviewed.

  9. Compact ion source neutron generator

    SciTech Connect

    Schenkel, Thomas; Persaud, Arun; Kapadia, Rehan; Javey, Ali; Chang-Hasnain, Constance; Rangelow, Ivo; Kwan, Joe

    2015-10-13

    A neutron generator includes a conductive substrate comprising a plurality of conductive nanostructures with free-standing tips and a source of an atomic species to introduce the atomic species in proximity to the free-standing tips. A target placed apart from the substrate is voltage biased relative to the substrate to ionize and accelerate the ionized atomic species toward the target. The target includes an element capable of a nuclear fusion reaction with the ionized atomic species to produce a one or more neutrons as a reaction by-product.

  10. Charge exchange molecular ion source

    DOEpatents

    Vella, Michael C.

    2003-06-03

    Ions, particularly molecular ions with multiple dopant nucleons per ion, are produced by charge exchange. An ion source contains a minimum of two regions separated by a physical barrier and utilizes charge exchange to enhance production of a desired ion species. The essential elements are a plasma chamber for production of ions of a first species, a physical separator, and a charge transfer chamber where ions of the first species from the plasma chamber undergo charge exchange or transfer with the reactant atom or molecules to produce ions of a second species. Molecular ions may be produced which are useful for ion implantation.

  11. Relating to monitoring ion sources

    DOEpatents

    Orr, Christopher Henry; Luff, Craig Janson; Dockray, Thomas; Macarthur, Duncan Whittemore; Bounds, John Alan

    2002-01-01

    The apparatus and method provide techniques for monitoring the position on alpha contamination in or on items or locations. The technique is particularly applicable to pipes, conduits and other locations to which access is difficult. The technique uses indirect monitoring of alpha emissions by detecting ions generated by the alpha emissions. The medium containing the ions is moved in a controlled manner frog in proximity with the item or location to the detecting unit and the signals achieved over time are used to generate alpha source position information.

  12. Astrophysics Source Code Library Enhancements

    NASA Astrophysics Data System (ADS)

    Hanisch, R. J.; Allen, A.; Berriman, G. B.; DuPrie, K.; Mink, J.; Nemiroff, R. J.; Schmidt, J.; Shamir, L.; Shortridge, K.; Taylor, M.; Teuben, P. J.; Wallin, J.

    2015-09-01

    The Astrophysics Source Code Library (ASCL)1 is a free online registry of codes used in astronomy research; it currently contains over 900 codes and is indexed by ADS. The ASCL has recently moved a new infrastructure into production. The new site provides a true database for the code entries and integrates the WordPress news and information pages and the discussion forum into one site. Previous capabilities are retained and permalinks to ascl.net continue to work. This improvement offers more functionality and flexibility than the previous site, is easier to maintain, and offers new possibilities for collaboration. This paper covers these recent changes to the ASCL.

  13. Gamma source for active interrogation

    DOEpatents

    Leung, Ka-Ngo; Lou, Tak Pui; Barletta, William A.

    2009-09-29

    A cylindrical gamma generator includes a coaxial RF-driven plasma ion source and target. A hydrogen plasma is produced by RF excitation in a cylindrical plasma ion generator using an RF antenna. A cylindrical gamma generating target is coaxial with the ion generator, separated by plasma and extraction electrodes which has many openings. The plasma generator emanates ions radially over 360.degree. and the cylindrical target is thus irradiated by ions over its entire circumference. The plasma generator and target may be as long as desired.

  14. Space Shuttle Payload Information Source

    NASA Technical Reports Server (NTRS)

    Griswold, Tom

    2000-01-01

    The Space Shuttle Payload Information Source Compact Disk (CD) is a joint NASA and USA project to introduce Space Shuttle capabilities, payload services and accommodations, and the payload integration process. The CD will be given to new payload customers or to organizations outside of NASA considering using the Space Shuttle as a launch vehicle. The information is high-level in a visually attractive format with a voice over. The format is in a presentation style plus 360 degree views, videos, and animation. Hyperlinks are provided to connect to the Internet for updates and more detailed information on how payloads are integrated into the Space Shuttle.

  15. Gamma source for active interrogation

    SciTech Connect

    Leung, Ka-Ngo; Lou, Tak Pui; Barletta, William A.

    2012-10-02

    A cylindrical gamma generator includes a coaxial RF-driven plasma ion source and target. A hydrogen plasma is produced by RF excitation in a cylindrical plasma ion generator using an RF antenna. A cylindrical gamma generating target is coaxial with the ion generator, separated by plasma and extraction electrodes which has many openings. The plasma generator emanates ions radially over 360.degree. and the cylindrical target is thus irradiated by ions over its entire circumference. The plasma generator and target may be as long as desired.

  16. ION SOURCE FOR A CALUTRON

    DOEpatents

    Lofgren, E.J.

    1959-04-14

    This patcnt relates to calutron devices and deals particularly with the mechanism used to produce the beam of ions wherein a charge material which is a vapor at room temperature is used. A charge container located outside the tank is connected through several conduits to various points along the arc chamber of the ion source. In addition, the rate of flow of the vapor to the arc chamber is controlled by a throttle valve in each conduit. By this arrangement the arc can be regulated accurately and without appreciable time lag, inasmuch as the rate of vapor flow is immediately responsive to the manipulation of the throttle valves.

  17. Detecting fission from special nuclear material sources

    DOEpatents

    Rowland, Mark S [Alamo, CA; Snyderman, Neal J [Berkeley, CA

    2012-06-05

    A neutron detector system for discriminating fissile material from non-fissile material wherein a digital data acquisition unit collects data at high rate, and in real-time processes large volumes of data directly into information that a first responder can use to discriminate materials. The system comprises counting neutrons from the unknown source and detecting excess grouped neutrons to identify fission in the unknown source. The system includes a graphing component that displays the plot of the neutron distribution from the unknown source over a Poisson distribution and a plot of neutrons due to background or environmental sources. The system further includes a known neutron source placed in proximity to the unknown source to actively interrogate the unknown source in order to accentuate differences in neutron emission from the unknown source from Poisson distributions and/or environmental sources.

  18. Chromium plating pollution source reduction by plasma source ion implantation

    SciTech Connect

    Chen, A.; Sridharan, K.; Dodd, R.A.; Conrad, J.R.; Qiu, X.; Hamdi, A.H.; Elmoursi, A.A.; Malaczynski, G.W.; Horne, W.G.

    1995-12-31

    There is growing concern over the environmental toxicity and workers` health issues due to the chemical baths and rinse water used in the hard chromium plating process. In this regard the significant hardening response of chromium to nitrogen ion implantation can be environmentally beneficial from the standpoint of decreasing the thickness and the frequency of application of chromium plating. In this paper the results of a study of nitrogen ion implantation of chrome plated test flats using the non-line-of-sight Plasma Source Ion Implantation (PSII) process, are discussed. Surface characterization was performed using Scanning Electron Microscopy (SEM), Auger Electron Spectroscopy (AES), and Electron Spectroscopy for Chemical Analysis (ESCA). The surface properties were evaluated using a microhardness tester, a pin-on-disk wear tester, and a corrosion measurement system. Industrial field testing of nitrogen PSII treated chromium plated parts showed an improvement by a factor of two compared to the unimplanted case.

  19. High Intensity Polarized Electron Sources

    SciTech Connect

    Poelker, Benard; Adderley, Philip; Brittian, Joshua; Clark, J.; Grames, Joseph; Hansknecht, John; McCarter, James; Stutzman, Marcy; Suleiman, Riad; Surles-law, Kenneth

    2008-02-01

    During the 1990s, at numerous facilities world wide, extensive R&D devoted to constructing reliable GaAs photoguns helped ensure successful accelerator-based nuclear and high-energy physics programs using spin polarized electron beams. Today, polarized electron source technology is considered mature, with most GaAs photoguns meeting accelerator and experiment beam specifications in a relatively trouble-free manner. Proposals for new collider facilities however, require electron beams with parameters beyond today's state-of-the-art and serve to renew interest in conducting polarized electron source R&D. And at CEBAF/Jefferson Lab, there is an immediate pressing need to prepare for new experiments that require considerably more beam current than before. One experiment in particular?Q-weak, a parity violation experiment that will look for physics beyond the Standard Model?requires 180 uA average current at polarization >80% for a duration of one year, with run-averaged helicity correlate

  20. Multi-source ion funnel

    DOEpatents

    Tang, Keqi; Belov, Mikhail B.; Tolmachev, Aleksey V.; Udseth, Harold R.; Smith, Richard D.

    2005-12-27

    A method for introducing ions generated in a region of relatively high pressure into a region of relatively low pressure by providing at least two electrospray ion sources, providing at least two capillary inlets configured to direct ions generated by the electrospray sources into and through each of the capillary inlets, providing at least two sets of primary elements having apertures, each set of elements having a receiving end and an emitting end, the primary sets of elements configured to receive a ions from the capillary inlets at the receiving ends, and providing a secondary set of elements having apertures having a receiving end and an emitting end, the secondary set of elements configured to receive said ions from the emitting end of the primary sets of elements and emit said ions from said emitting end of the secondary set of elements. The method may further include the step of providing at least one jet disturber positioned within at least one of the sets of primary elements, providing a voltage, such as a dc voltage, in the jet disturber, thereby adjusting the transmission of ions through at least one of the sets of primary elements.

  1. 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.

  2. Source mechanism of volcanic tremor

    SciTech Connect

    Ferrick, M.G.; Qamar, A.; St. Lawrence, W.F.

    1982-10-10

    Low-frequency (<10 Hz) volcanic earthquakes originate at a wide range of depths and occur before, during, and after magmatic eruptions. The characteristics of these earthquakes suggest that they are not typical tectonic events. Physically analogous processes occur in hydraulic fracturing of rock formations, low-frequency icequakes in temperate glaciers, and autoresonance in hydroelectric power stations. We propose that unsteady fluid flow in volcanic conduits is the common source mechanism of low-frequency volcanic earthquakes (tremor). The fluid dynamic source mechanism explains low-frequency earthquakes of arbitrary duration, magnitude, and depth of origin, as unsteady flow is independent of physical properties of the fluid and conduit. Fluid transients occur in both low-viscosity gases and high-viscosity liquids. A fluid transient analysis can be formulated as generally as is warranted by knowledge of the composition and physical properties of the fluid, material properties, geometry and roughness of the conduit, and boundary conditions. To demonstrate the analytical potential of the fluid dynamic theory, we consider a single-phase fluid, a melt of Mount Hood andesite at 1250/sup 0/C, in which significant pressure and velocity variations occur only in the longitudinal direction. Further simplification of the conservation of mass and momentum equations presents an eigenvalue problem that is solved to determine the natural frequencies and associated damping of flow and pressure oscillations.

  3. Anisotropic universe with anisotropic sources

    SciTech Connect

    Aluri, Pavan K.; Panda, Sukanta; Sharma, Manabendra; Thakur, Snigdha E-mail: sukanta@iiserb.ac.in E-mail: snigdha@iiserb.ac.in

    2013-12-01

    We analyze the state space of a Bianchi-I universe with anisotropic sources. Here we consider an extended state space which includes null geodesics in this background. The evolution equations for all the state observables are derived. Dynamical systems approach is used to study the evolution of these equations. The asymptotic stable fixed points for all the evolution equations are found. We also check our analytic results with numerical analysis of these dynamical equations. The evolution of the state observables are studied both in cosmic time and using a dimensionless time variable. Then we repeat the same analysis with a more realistic scenario, adding the isotropic (dust like dark) matter and a cosmological constant (dark energy) to our anisotropic sources, to study their co-evolution. The universe now approaches a de Sitter space asymptotically dominated by the cosmological constant. The cosmic microwave background anisotropy maps due to shear are also generated in this scenario, assuming that the universe contains anisotropic matter along with the usual (dark) matter and vacuum (dark) energy since decoupling. We find that they contribute dominantly to the CMB quadrupole. We also constrain the current level of anisotropy and also search for any cosmic preferred axis present in the data. We use the Union 2 Supernovae data to this extent. An anisotropy axis close to the mirror symmetry axis seen in the cosmic microwave background data from Planck probe is found.

  4. PHARMACEUTICALS IN SOURCE WATER - OVERVIEW ...

    EPA Pesticide Factsheets

    There is no abstract available for this product. If further information is requested, please refer to the bibliographic citation and contact the person listed under Contact field. The research focused on in the subtasks is the development and application of state-of the-art technologies to meet the needs of the public, Office of Water, and ORD in the area of Water Quality. Located In the subtasks are the various research projects being performed in support of this Task and more in-depth coverage of each project. Briefly, each project's objective is stated below.Subtask 1: To integrate state-of-the-art technologies (polar organic chemical integrative samplers, advanced solid-phase extraction methodologies with liquid chromatography/electrospray/mass spectrometry) and apply them to studying the sources and fate of a select list of PPCPs. Application and improvement of analytical methodologies that can detect non-volatile, polar, water-soluble pharmaceuticals in source waters at levels that could be environmentally significant (at concentrations less than parts per billion, ppb). IAG with USGS ends in FY05. APM 20 due in FY05.Subtask 2: Coordination of interagency research and public outreach activities for PPCPs. Participate on NSTC Health and Environment subcommittee working group on PPCPs. Web site maintenance and expansion, invited technical presentations, invited articles for peer-reviewed journals, interviews for media, responding to public inquiries. S

  5. Sweetening agents from natural sources.

    PubMed

    Morris, J A

    1976-01-01

    Sweetness is an important taste sensation to humans. The absence of suitable sweeteners as alternatives to cyclamates and saccharin has led to a renewed interest in sweeteners form natural sources. A brief review of the history of sweetener usage provides a basis for understanding our present heavy consumption of sweet substances. The structure of naturally-occurring compounds possessing a sweet taste range from simple sugars to complex, intensely sweet proteins. The structural types include monoterpenes, diterpenes, triterpenes, flavonoids, steroid saponins, dipeptides, and proteins. Some of these substances are not, strictly-speaking, natural but are derived from natural sources by relatively minor chemical modification. The properties of two non-sweet substances, miraculin and gymnemic acid, are included because of their close relationship to the subject of sweeteners. Miraculin causes sour substances to taste sweet and gymnemic acid selectively blocks sweet taste perception. The second part of the paper presents some of the work on monellin, the intensely sweet protein from "serendipity berries" (Dioscoreophyllum cumminsii). The physico-chemical studies of monellin provide convincing evidence that it is, indeed, a protein. Structural studies using denaturants and specific chemical modifications have provided a beginning of our understanding of the molecular basis of the sweet taste of monellin.

  6. Environmental source of arsenic exposure.

    PubMed

    Chung, Jin-Yong; Yu, Seung-Do; Hong, Young-Seoub

    2014-09-01

    Arsenic is a ubiquitous, naturally occurring metalloid that may be a significant risk factor for cancer after exposure to contaminated drinking water, cigarettes, foods, industry, occupational environment, and air. Among the various routes of arsenic exposure, drinking water is the largest source of arsenic poisoning worldwide. Arsenic exposure from ingested foods usually comes from food crops grown in arsenic-contaminated soil and/or irrigated with arsenic-contaminated water. According to a recent World Health Organization report, arsenic from contaminated water can be quickly and easily absorbed and depending on its metabolic form, may adversely affect human health. Recently, the US Food and Drug Administration regulations for metals found in cosmetics to protect consumers against contaminations deemed deleterious to health; some cosmetics were found to contain a variety of chemicals including heavy metals, which are sometimes used as preservatives. Moreover, developing countries tend to have a growing number of industrial factories that unfortunately, harm the environment, especially in cities where industrial and vehicle emissions, as well as household activities, cause serious air pollution. Air is also an important source of arsenic exposure in areas with industrial activity. The presence of arsenic in airborne particulate matter is considered a risk for certain diseases. Taken together, various potential pathways of arsenic exposure seem to affect humans adversely, and future efforts to reduce arsenic exposure caused by environmental factors should be made.

  7. Soybean, a promising health source.

    PubMed

    Mateos-Aparicio, I; Redondo Cuenca, A; Villanueva-Suárez, M J; Zapata-Revilla, M A

    2008-01-01

    Health properties and uses of soybean, as well as the different chemical and botanical characteristics of this legume are shown in this review. Soybean represents an excellent source of high quality protein, it has a low content in saturated fat, it contains a great amount of dietary fibre and its isoflavone content makes it singular among other legumes. Many researches have been carried out into the benefits of legumes: chickpeas, beans, lentils and soy, among others, but characterization and positive health effects of soybeans have been recently studied. The interest in this legume has increased because of its functional components. Most of the studies have been focused on soybean protein as a possible source of prevention against cardiovascular disease. This positive effect may be due to a decrease in serum cholesterol concentrations. In addition, there are many studies on isoflavones, non-nutritive substances, associated with prevention and treatment of different chronic diseases. Moreover, some studies have shown the health properties of soy dietary fibre. Therefore, it would be interesting to consider the replacement of animal based foods for soybean foods in order to obtain some nutritional benefits.

  8. Environmental Source of Arsenic Exposure

    PubMed Central

    Chung, Jin-Yong; Yu, Seung-Do; Hong, Young-Seoub

    2014-01-01

    Arsenic is a ubiquitous, naturally occurring metalloid that may be a significant risk factor for cancer after exposure to contaminated drinking water, cigarettes, foods, industry, occupational environment, and air. Among the various routes of arsenic exposure, drinking water is the largest source of arsenic poisoning worldwide. Arsenic exposure from ingested foods usually comes from food crops grown in arsenic-contaminated soil and/or irrigated with arsenic-contaminated water. According to a recent World Health Organization report, arsenic from contaminated water can be quickly and easily absorbed and depending on its metabolic form, may adversely affect human health. Recently, the US Food and Drug Administration regulations for metals found in cosmetics to protect consumers against contaminations deemed deleterious to health; some cosmetics were found to contain a variety of chemicals including heavy metals, which are sometimes used as preservatives. Moreover, developing countries tend to have a growing number of industrial factories that unfortunately, harm the environment, especially in cities where industrial and vehicle emissions, as well as household activities, cause serious air pollution. Air is also an important source of arsenic exposure in areas with industrial activity. The presence of arsenic in airborne particulate matter is considered a risk for certain diseases. Taken together, various potential pathways of arsenic exposure seem to affect humans adversely, and future efforts to reduce arsenic exposure caused by environmental factors should be made. PMID:25284196

  9. PHARMACEUTICALS IN THE ENVIRONMENT: SOURCES ...

    EPA Pesticide Factsheets

    An issue that began to receive more attention by environmental scientists in the late 1990s was the conveyancy of pharmaceuticals in the environment by way of their use in human and veterinary medical practices and personal care The research focused on in the subtasks is the development and application of state-of the-art technologies to meet the needs of the public, Office of Water, and ORD in the area of Water Quality. Located In the subtasks are the various research projects being performed in support of this Task and more in-depth coverage of each project. Briefly, each project's objective is stated below.Subtask 1: To integrate state-of-the-art technologies (polar organic chemical integrative samplers, advanced solid-phase extraction methodologies with liquid chromatography/electrospray/mass spectrometry) and apply them to studying the sources and fate of a select list of PPCPs. Application and improvement of analytical methodologies that can detect non-volatile, polar, water-soluble pharmaceuticals in source waters at levels that could be environmentally significant (at concentrations less than parts per billion, ppb). IAG with USGS ends in FY05. APM 20 due in FY05.Subtask 2: Coordination of interagency research and public outreach activities for PPCPs. Participate on NSTC Health and Environment subcommittee working group on PPCPs. Web site maintenance and expansion, invited technical presentations, invited articles for peer-reviewed journals, intervi

  10. Spallation source materials test program

    SciTech Connect

    Maloy, S.A.; Sommer, W.F.

    1997-12-01

    A spallation source materials program has been developed to irradiate and test candidate materials (Inconel 718, 316L and 304L stainless steel, modified 9Cr-1Mo(T91), Al6061-T6, Al5052-O) for use in the Accelerator Production of Tritium (APT) target and blanket in prototypic proton and neutron fluxes at prototypic temperatures. The study uses the 800 MeV, 1mA proton accelerator at the Los Alamos Neutron Science Center (LANSCE) which produces a Gaussian beam with 2 sigma = 3 cm. The experimental set-up contains prototypic modules of the tungsten neutron source and the lead/aluminum blanket with mechanical testing specimens of candidate APT materials placed in specific locations in the irradiation area. These specimens have been irradiated for greater than 3,600 hours with a maximum proton fluence of 4--5 {times} 10{sup 21} p/cm{sup 2} in the center of the proton beam. Specimens will yield some of the first data on the effect of proton irradiation to high dose on the materials` properties from tensile tests, 3 pt. bend tests, fracture toughness tests, pressurized tubes, U-bend stress corrosion cracking specimens, corrosion measurements and microstructural characterization of transmission electron microscopy specimens.

  11. Light Sources and Lighting Circuits

    NASA Astrophysics Data System (ADS)

    Honda, Hisashi; Suwa, Takumi; Yasuda, Takeo; Ohtani, Yoshihiko; Maehara, Akiyoshi; Okada, Atsunori; Komatsu, Naoki; Mannami, Tomoaki

    According to the Machinery Statistics of the Ministry of Economy, Trade and Industry, the production of incandescent lamps in Japan in 2007 was 990 million units (90.0% of the previous year's total), in which the production of incandescent lamps for general lighting was 110 million units (90.0% of the previous year's total) and of tungsten-halogen lamps was 44 million units (96.6% of the previous year's total). The production of fluorescent lamps was 927 million units (93.9% of the previous year's total), in which general fluorescent lamps, excluding those for LCD back lighting, was 320 million units (87.2% of the previous year's total). Also, the production of HID lamps was 10 million units (101.5% of the previous year's total). On the other hand, when the numbers of sales are compared with the sales of the previous year, incandescent lamps for general use was 99.8%, tungsten-halogen lamps was 96.9%, fluorescent lamps was 95.9%, and HID lamps was 98.9%. Self-ballasted fluorescent lamps alone showed an increase in sales as strong as 29 million units, or 121.7% of the previous year's sales. It is considered that the switchover of incandescent lamps to HID lamps was promoted for energy conservation and carbon dioxide reduction with the problem of global warming in the background. In regard to exhibitions, Lighting Fair 2007 was held in Tokyo in March, and LIGHTFAIR INTERNATIONAL 2007 was held in New York in May. Regarding academic conferences, LS:11 (the 11th International Symposium on the Science & Technology of Light Sources) was held in Shanghai in May, and the First International Conference on White LEDs and Solid State Lighting was held in Tokyo in November. Both conferences suggested that there are strong needs and concerns now about energy conservation, saving natural resources, and restrictions of hazardous materials. In regard to incandescent lamps, the development of products aiming at higher efficacy, electric power savings, and longer life was advanced by

  12. 10 CFR 39.43 - Inspection, maintenance, and opening of a source or source holder.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... holder. (a) Each licensee shall visually check source holders, logging tools, and source handling tools... holders, logging tools, injection tools, source handling tools, storage containers, transport containers... after the defect is found. (c) Removal of a sealed source from a source holder or logging tool,...

  13. Liquid metal ion source and alloy

    DOEpatents

    Clark, Jr., William M.; Utlaut, Mark W.; Behrens, Robert G.; Szklarz, Eugene G.; Storms, Edmund K.; Santandrea, Robert P.; Swanson, Lynwood W.

    1988-10-04

    A liquid metal ion source and alloy, wherein the species to be emitted from the ion source is contained in a congruently vaporizing alloy. In one embodiment, the liquid metal ion source acts as a source of arsenic, and in a source alloy the arsenic is combined with palladium, preferably in a liquid alloy having a range of compositions from about 24 to about 33 atomic percent arsenic. Such an alloy may be readily prepared by a combustion synthesis technique. Liquid metal ion sources thus prepared produce arsenic ions for implantation, have long lifetimes, and are highly stable in operation.

  14. Repatriation of US sources from Brazil

    SciTech Connect

    Tompkins, Andrew J

    2008-01-01

    IAEA's interest in excess and unwanted sealed sources extends back to when radium sources were a problem throughout the world. Sta11ing in 1994, world wide IAEA member states inventoried and consolidated radium (Ra)-226 sources. IAEA then trained Regional Teams in the conditioning of Ra-226 sealed sources for long term storage, which resulted in the Regional Teams conditioning about 14,000 radium sources. These sources remained in their respective IAEA member state locations. Regional teams were seen as a way to encourage member state (local) management of a world wide problem, as well as a more cost effective solution.

  15. A Framework for Characterizing Drug Information Sources

    PubMed Central

    Sharp, Mark; Bodenreider, Olivier; Wacholder, Nina

    2008-01-01

    Drug information is complex, voluminous, heterogeneous, and dynamic. Multiple sources are available, each providing some elements of information about drugs (usually for a given purpose), but there exists no integrated view or directory that could be used to locate sources appropriate to a given purpose. We examined 23 sources that provide drug information in the pharmacy, chemistry, biology, and clinical medicine domains. Their drug information content could be categorized with 39 dimensions. We propose this list of dimensions as a framework for characterizing drug information sources. As an evaluation, we show that this framework is useful for comparing drug information sources and selecting sources most relevant to a given use case. PMID:18999182

  16. Thulium heat sources for space power applications

    SciTech Connect

    Alderman, C.J.

    1992-05-01

    Reliable power supplies for use in transportation and remote systems will be an important part of space exploration terrestrial activities. A potential power source is available in the rare earth metal, thulium. Fuel sources can be produced by activating Tm-169 targets in the space station reactor. The resulting Tm-170 heat sources can be used in thermoelectric generators to power instrumentation and telecommunications located at remote sites such as weather stations. As the heat source in a dynamic Sterling or Brayton cycle system, the heat source can provide a lightweight power source for rovers or other terrestrial transportation systems.

  17. Role of source coherence in atom interferometery

    NASA Astrophysics Data System (ADS)

    Hardman, Kyle S.; Kuhn, Carlos C. N.; McDonald, Gordon D.; Debs, John E.; Bennetts, Shayne; Close, John D.; Robins, Nicholas P.

    2014-02-01

    The role of source cloud spatial coherence in a Mach-Zehnder-type atom interferometer is experimentally investigated. The visibility and contrast of a Bose-Einstein condensate (BEC) and three thermal sources with varying spatial coherence are compared as a function of interferometer time. At short times, the fringe visibility of a BEC source approaches 100% nearly independent of π pulse efficiency, while thermal sources have fringe visibilities limited to the π pulse efficiency. More importantly for precision measurement systems, the BEC source maintains interference at interferometer times significantly beyond the thermal source.

  18. Exemples d’utilisation des techniques d’optimisation en calcul de structures de reacteurs

    DTIC Science & Technology

    2003-03-01

    en c~uvre n~cessite, dans un bureau d𔄀tudes, le couplage automatique d’un logiciel de CAO param~tr~e, d’un logiciel de maillages, d’un solveur...616ment finis et d’un logiciel d’optimisation. Certains logiciels int~grent toutes ces fonctionnalit~s de faqon o’ transparente »> et ont donc des...pourquoi, ces derni~res ann~es, se sont d~velopp~s des logiciels d’optimisation ouverts permettant de g~rer tout type de mod~lisation. Ces logiciels

  19. Optimisation de la gestion du combustible dans les reacteurs CANDU refroidis a l'eau legere

    NASA Astrophysics Data System (ADS)

    Chambon, Richard

    This research has two main goals. First, we wanted to introduce optimization tools in the diffusion code DONJON, mostly for fuel management. The second objective is more practical. The optimization capabilities are applied to the fuel management problem for different CANDU reactors at refueling equilibrium state. Two kinds of approaches are considered and implemented in this study to solve optimization problems in the code DONJON. The first methods are based on gradients and on the quasi-linear mathematical programming. The method initially developed in the code OPTEX is implemented as a reference approach for the gradient based methods. However, this approach has a major drawback. Indeed, the starting point has to be a feasible point. Then, several approaches have been developed to be more general and not limited by the initial point choice. Among the different methods we developed, two were found to be very efficient: the multi-step method and the mixte method. The second kind of approach are the meta-heuristic methods. We implemented the tabu search method. Initially, it was designed to optimize combinatory variable problems. However, we successfully used it for continuous variables. The major advantage of the tabu method over the gradient methods is the capability to exit from local minima. Optimisation of the average exit burnup has been performed for CANDU-6 and ACR-700 reactors. The fresh fuel enrichment has also been optimized for ACR-700. Results match very well what the reactor physics can predict. Moreover, a comparison of the two totally different types of optimization methods validated the results we obtained.

  20. Modelisation et simulation de pyrolyse de pneus usages dans des reacteurs de laboratoire et industriel

    NASA Astrophysics Data System (ADS)

    Lanteigne, Jean-Remi

    The present thesis covers an applied study on tire pyrolysis. The main objective is to develop tools to allow predicting the production and the quality of oil from tire pyrolysis. The first research objective consisted in modelling the kinetics of tires pyrolysis in a reactor, namely an industrial rotary drum operating in batch mode. A literature review performed later demonstrated that almost all kinetics models developed to represent tire pyrolysis could not represent the actual industrial process with enough accuracy. Among the families of kinetics models for pyrolysis, three have been identified: models with one single global reaction, models with multiple combined parallel reactions, and models with multiple parallel and series reactions. It was observed that these models show limitations. In the models with one single global reaction and with multiple parallels reactions, the production of each individual pyrolytic product cannot be predicted, but only for combined volatiles. Morevoer, the mass term in the kinetics refers to the final char weight (Winfinity) that varies with pyrolysis conditions, which yields less robust models. Also, despite the fact that models with multiple parallels and series reactions can predict the rate of production for each pyrolysis product, the selectivities are determined for operating temperatures instead of real mass temperatures, giving models for which parameters tuning is not adequate when used at the industrial scale. A new kinetics model has been developed, allowing predicting the rate of production of noncondensable gas, oil, and char from tire pyrolysis. The novelty of this model is the consideration of intrinsic selectivities for each product as a function of temperature. This hypothesis has been assumed valid considering that in the industrial pyrolysis process, pyrolysis kinetics is limiting. The developed model considers individual kinetics for each of the three pyrolytic products proportional to the global decomposition kinetics of pyrolysables. The simulation with data obtained in industrial operation showed the robustness of the model to predict with accuracy in transient regime, tires pyrolysis, with the help of model parameters obtained at laboratory scale, namely in regards of the trigger of production, the residence time of tires (dynamic production) and the amount of oil produced (cumulative yield). It is a novel way to model pyrolysis that could be extrapolated to new waste materials. The second objective of this doctoral research was to determine the evolution of specific tires specific heat during pyrolysis and the enthalpy of pyrolysis. The origin of this objective comes from a primary contradiction. With few exceptions, it is acknowledged that organic materials pyrolysis is globally an endothermic phenomenon. At the opposite, all experiments led with laboratory apparatuses such as DSC (Differential Scanning Calorimetry) showed exothermic peaks during dynamic experiments (constant heating rate). It has been confirmed by results obtained at the industrial scale, where no sign of exothermicity has been observed. The Hess Law has also confirmed these results, that globally, pyrolysis is indeed a completely endothermic process. An accurate energy balance is required to predict mass temperature during pyrolysis, this parameter being unbindable from kinetics. An advanced investigation of char first allowed demonstrating that specific heat of solids during pyrolysis decreases with increasing temperature until the weight loss peak is reached, around 400°C, and then starts increasing again. This observation, combined with the fact that the sample loses weight during pyrolysis is considered as the major cause of the apparition of an exothermic peak in laboratory scale experiments. That is, the control system of these apparatuses generates a bias and an unavoidable overheat of the samples producing this exothermic behavior. It would thus be an artifact. On the base of new data on the evolution of global specific heat during pyrolysis, a model of the energy balance has be

  1. Methodes d'optimisation des parametres 2D du reflecteur dans un reacteur a eau pressurisee

    NASA Astrophysics Data System (ADS)

    Clerc, Thomas

    With a third of the reactors in activity, the Pressurized Water Reactor (PWR) is today the most used reactor design in the world. This technology equips all the 19 EDF power plants. PWRs fit into the category of thermal reactors, because it is mainly the thermal neutrons that contribute to the fission reaction. The pressurized light water is both used as the moderator of the reaction and as the coolant. The active part of the core is composed of uranium, slightly enriched in uranium 235. The reflector is a region surrounding the active core, and containing mostly water and stainless steel. The purpose of the reflector is to protect the vessel from radiations, and also to slow down the neutrons and reflect them into the core. Given that the neutrons participate to the reaction of fission, the study of their behavior within the core is capital to understand the general functioning of how the reactor works. The neutrons behavior is ruled by the transport equation, which is very complex to solve numerically, and requires very long calculation. This is the reason why the core codes that will be used in this study solve simplified equations to approach the neutrons behavior in the core, in an acceptable calculation time. In particular, we will focus our study on the diffusion equation and approximated transport equations, such as SPN or S N equations. The physical properties of the reflector are radically different from those of the fissile core, and this structural change causes important tilt in the neutron flux at the core/reflector interface. This is why it is very important to accurately design the reflector, in order to precisely recover the neutrons behavior over the whole core. Existing reflector calculation techniques are based on the Lefebvre-Lebigot method. This method is only valid if the energy continuum of the neutrons is discretized in two energy groups, and if the diffusion equation is used. The method leads to the calculation of a homogeneous reflector. The aim of this study is to create a computational scheme able to compute the parameters of heterogeneous, multi-group reflectors, with both diffusion and SPN/SN operators. For this purpose, two computational schemes are designed to perform such a reflector calculation. The strategy used in both schemes is to minimize the discrepancies between a power distribution computed with a core code and a reference distribution, which will be obtained with an APOLLO2 calculation based on the method Method Of Characteristics (MOC). In both computational schemes, the optimization parameters, also called control variables, are the diffusion coefficients in each zone of the reflector, for diffusion calculations, and the P-1 corrected macroscopic total cross-sections in each zone of the reflector, for SPN/SN calculations (or correction factors on these parameters). After a first validation of our computational schemes, the results are computed, always by optimizing the fast diffusion coefficient for each zone of the reflector. All the tools of the data assimilation have been used to reflect the different behavior of the solvers in the different parts of the core. Moreover, the reflector is refined in six separated zones, corresponding to the physical structure of the reflector. There will be then six control variables for the optimization algorithms. [special characters omitted]. Our computational schemes are then able to compute heterogeneous, 2-group or multi-group reflectors, using diffusion or SPN/SN operators. The optimization performed reduces the discrepancies distribution between the power computed with the core codes and the reference power. However, there are two main limitations to this study: first the homogeneous modeling of the reflector assemblies doesn't allow to properly describe its physical structure near the core/reflector interface. Moreover, the fissile assemblies are modeled in infinite medium, and this model reaches its limit at the core/reflector interface. These two problems should be tackled in future studies. (Abstract shortened by UMI.).

  2. The DCU laser ion source.

    PubMed

    Yeates, P; Costello, J T; Kennedy, E T

    2010-04-01

    Laser ion sources are used to generate and deliver highly charged ions of various masses and energies. We present details on the design and basic parameters of the DCU laser ion source (LIS). The theoretical aspects of a high voltage (HV) linear LIS are presented and the main issues surrounding laser-plasma formation, ion extraction and modeling of beam transport in relation to the operation of a LIS are detailed. A range of laser power densities (I approximately 10(8)-10(11) W cm(-2)) and fluences (F=0.1-3.9 kJ cm(-2)) from a Q-switched ruby laser (full-width half-maximum pulse duration approximately 35 ns, lambda=694 nm) were used to generate a copper plasma. In "basic operating mode," laser generated plasma ions are electrostatically accelerated using a dc HV bias (5-18 kV). A traditional einzel electrostatic lens system is utilized to transport and collimate the extracted ion beam for detection via a Faraday cup. Peak currents of up to I approximately 600 microA for Cu(+) to Cu(3+) ions were recorded. The maximum collected charge reached 94 pC (Cu(2+)). Hydrodynamic simulations and ion probe diagnostics were used to study the plasma plume within the extraction gap. The system measured performance and electrodynamic simulations indicated that the use of a short field-free (L=48 mm) region results in rapid expansion of the injected ion beam in the drift tube. This severely limits the efficiency of the electrostatic lens system and consequently the sources performance. Simulations of ion beam dynamics in a "continuous einzel array" were performed and experimentally verified to counter the strong space-charge force present in the ion beam which results from plasma extraction close to the target surface. Ion beam acceleration and injection thus occur at "high pressure." In "enhanced operating mode," peak currents of 3.26 mA (Cu(2+)) were recorded. The collected currents of more highly charged ions (Cu(4+)-Cu(6+)) increased considerably in this mode of operation.

  3. Enhanced Radioactive Material Source Security.

    PubMed

    Klinger, Joseph G

    2016-02-01

    Requirements for additional security measures for sealed radioactive sources have evolved since they were first implemented after the terrorist events of 11 September 2001. This paper will describe the sequence of those measures, commencing with the early orders issued by the U.S. Nuclear Regulatory Commission to the May 2013 adoption of 10 CFR Part 37, Physical Protections of Category 1 and Category 2 Quantities of Radioactive Material. Part 37 requirements will be discussed in detail, as the 37 NRC Agreement States, which regulate approximately 88% of the radioactive material licensees, will be required to enact by 19 March 2016. In addition to the Part 37 requirements, the paper will also highlight some of the other ongoing efforts of the U.S. Department of Energy's National Nuclear Security Administration's Global Threat Reduction Initiative and the Conference of Radiation Control Program Directors.

  4. Solenoid and monocusp ion source

    SciTech Connect

    Brainard, John Paul; Burns, Erskine John Thomas; Draper, Charles Hadley

    1997-01-01

    An ion source which generates hydrogen ions having high atomic purity incorporates a solenoidal permanent magnets to increase the electron path length. In a sealed envelope, electrons emitted from a cathode traverse the magnetic field lines of a solenoid and a monocusp magnet between the cathode and a reflector at the monocusp. As electrons collide with gas, the molecular gas forms a plasma. An anode grazes the outer boundary of the plasma. Molecular ions and high energy electrons remain substantially on the cathode side of the cusp, but as the ions and electrons are scattered to the aperture side of the cusp, additional collisions create atomic ions. The increased electron path length allows for smaller diameters and lower operating pressures.

  5. Solenoid and monocusp ion source

    SciTech Connect

    Brainard, J.P.; Burns, E.J.T.; Draper, C.H.

    1995-12-31

    An ion source which generates ions having high atomic purity incorporates a solenoidal magnetic field to increase the electron path length. In a sealed envelope, electrons emitted from a cathode traverse the magnetic field lines of a solenoid and a monocusp magnet between the cathode and a reflector at the monocusp. As electrons collide with gas, the molecular gas forms a plasma. An anode grazes the outer boundary of the plasma. Molecular ions and high energy electrons remain substantially on the cathode side of the cusp, but as the ions and electrons are scattered to the aperture side of the cusp, additional collisions create atomic ions. The increased electron path length allows for smaller diameters and lower operating pressures.

  6. Laser sources for lidar applications

    NASA Astrophysics Data System (ADS)

    Kilmer, J.; Iadevaia, A.; Yin, Y.

    2012-06-01

    Advanced LIDAR applications such as next gen: Micro Pulse; Time of Flight (e.g., Satellite Laser Ranging); Coherent and Incoherent Doppler (e.g., Wind LIDAR); High Spectral Resolution; Differential Absorption (DIAL); photon counting LIDAR (e.g., 3D LIDAR); are placing more demanding requirements on conventional lasers (e.g., increased rep rates, etc.) and have inspired the development of new types of laser sources. Today, solid state lasers are used for wind sensing, 2D laser Radar, 3D scanning and flash LIDAR. In this paper, we report on the development of compact, highly efficient, high power all-solidstate diode pulsed pumped ns lasers, as well as, high average power/high pulse energy sub nanosecond (<1ns) and picosecond (<100ps) lasers for these next gen LIDAR applications.

  7. Solenoid and monocusp ion source

    DOEpatents

    Brainard, J.P.; Burns, E.J.T.; Draper, C.H.

    1997-10-07

    An ion source which generates hydrogen ions having high atomic purity incorporates a solenoidal permanent magnets to increase the electron path length. In a sealed envelope, electrons emitted from a cathode traverse the magnetic field lines of a solenoid and a monocusp magnet between the cathode and a reflector at the monocusp. As electrons collide with gas, the molecular gas forms a plasma. An anode grazes the outer boundary of the plasma. Molecular ions and high energy electrons remain substantially on the cathode side of the cusp, but as the ions and electrons are scattered to the aperture side of the cusp, additional collisions create atomic ions. The increased electron path length allows for smaller diameters and lower operating pressures. 6 figs.

  8. General Purpose Heat Source Simulator

    NASA Technical Reports Server (NTRS)

    Emrich, William J., Jr.

    2008-01-01

    The General Purpose Heat Source (GPHS) project seeks to combine the development of an electrically heated, single GPHS module simulator with the evaluation of potential nuclear surface power systems. The simulator is designed to match the form, fit, and function of actual GPHS modules which normally generate heat through the radioactive decay of Pu238. The use of electrically heated modules rather than modules containing Pu238 facilitates the testing of the subsystems and systems without sacrificing the quantity and quality of the test data gathered. Current GPHS activities are centered on developing robust heater designs with sizes and weights which closely match those of actual Pu238 fueled GPHS blocks. Designs are being pursued which will allow operation up to 1100 C.

  9. General Purpose Heat Source Simulator

    NASA Technical Reports Server (NTRS)

    Emrich, Bill

    2008-01-01

    The General Purpose Heat Source (GPHS) simulator project is designed to replicate through the use of electrical heaters, the form, fit, and function of actual GPHS modules which generate heat through the radioactive decay of Pu238. The use of electrically heated modules rather than modules containing Pu238 facilitates the testing of spacecraft subsystems and systems without sacrificing the quantity and quality of the test data gathered. Previous GPHS activities are centered around developing robust heater designs with sizes and weights that closely matched those of actual Pu238 fueled GPHS blocks. These efforts were successful, although their maximum temperature capabilities were limited to around 850 C. New designs are being pursued which also replicate the sizes and weights of actual Pu238 fueled GPHS blocks but will allow operation up to 1100 C.

  10. Hydrogen hollow cathode ion source

    NASA Technical Reports Server (NTRS)

    Mirtich, M. J., Jr.; Sovey, J. S.; Roman, R. F. (Inventor)

    1980-01-01

    A source of hydrogen ions is disclosed and includes a chamber having at one end a cathode which provides electrons and through which hydrogen gas flows into the chamber. Screen and accelerator grids are provided at the other end of the chamber. A baffle plate is disposed between the cathode and the grids and a cylindrical baffle is disposed coaxially with the cathode at the one end of the chamber. The cylindrical baffle is of greater diameter than the baffle plate to provide discharge impedance and also to protect the cathode from ion flux. An anode electrode draws the electrons away from the cathode. The hollow cathode includes a tubular insert of tungsten impregnated with a low work function material to provide ample electrons. A heater is provided around the hollow cathode to initiate electron emission from the low work function material.

  11. Gravitational energy sources in Jupiter

    NASA Technical Reports Server (NTRS)

    Flasar, F. M.

    1973-01-01

    Gravitational sources of the intrinsic luminosity of Jupiter are examined in the context of current hydrogen-helium models. When no gravitational separation of matter occurs, the amount of heat which can be released over the remaining lifetime of the planet is necessarily limited by the size of its existing reservoir of thermal energy. This conclusion rests only on the assumption that its interior is relatively cold and degenerate. If gravitational unmixing occurs, the size of the thermal reservoir does not necessarily limit the heat output. If core formation occurs, for example, then the size of the core formed will be a limiting factor. The energy released with the formation of a helium core is computed for Jupiter. A core growth rate, averaged over several billion years, of 20 trillionths of Jupiter's mass per year is required if gravitational separation is to play a significant role in the thermal evolution.

  12. Antiproton source beam position system

    NASA Astrophysics Data System (ADS)

    Bagwell, T.; Holmes, S.; McCarthy, J.; Webber, R.

    1984-05-01

    The TeV I Beam Position Monitor (BPM) system is designed to provide a useful diagnostic tool during both the commissioning and operational phases of the antiproton source. The design goal is to provide single turn beam position information for intensities of 1 x 10 to the 9th particles, and multi-turn (closed orbit) information for beam intensities of 1 x 10 to the 7th particles, both with submillimeter resolution. It is anticipated that the system will be used during commissioning for establishing the first turn through the debuncher and accumulator, for aligning injection orbits, for providing information necessary to correct closed orbits, and for measuring various machine parameters (tunes, dispersion, apertures, and chromaticity). During normal antiproton operation the system will be used to monitor the beam position throughout the accumulation process.

  13. Multiple source ground heat storage

    NASA Astrophysics Data System (ADS)

    Belzile, P.; Lamarche, L.; Rousse, D. R.

    2016-09-01

    Sharing geothermal borefields is usually done with each borehole having the same inlet conditions (flow rate, temperature and fluid). The objective of this research is to improve the energy efficiency of shared and hybrid geothermal borefields by segregating heat transfer sources. Two models are briefly presented: The first model allows the segregation of the inlet conditions for each borefields; the second model allows circuits to be defined independently for each leg of double U-tubes in a borehole. An application couples residential heat pumps and arrays of solar collectors. Independent circuits configuration gave the best energy savings in a symmetric configuration, the largest shank spacing and with solar collectors functioning all year long. The boreholes have been shortened from 300 m to 150 m in this configuration.

  14. Advanced Neutron Source enrichment study

    SciTech Connect

    Bari, R.A.; Ludewig, H.; Weeks, J.R.

    1994-12-31

    A study has been performed of the impact on performance of using low enriched uranium (20% {sup 235}U) or medium enriched uranium (35% {sup 235}U) as an alternative fuel for the Advanced Neutron Source, which is currently designed to use uranium enriched to 93% {sup 235}U. Higher fuel densities and larger volume cores were evaluated at the lower enrichments in terms of impact on neutron flux, safety, safeguards, technical feasibility, and cost. The feasibility of fabricating uranium silicide fuel at increasing material density was specifically addressed by a panel of international experts on research reactor fuels. The most viable alternative designs for the reactor at lower enrichments were identified and discussed. Several sensitivity analyses were performed to gain an understanding of the performance of the reactor at parametric values of power, fuel density, core volume, and enrichment that were interpolations between the boundary values imposed on the study or extrapolations from known technology.

  15. Resonance microwave volume plasma source

    SciTech Connect

    Berezhetskaya, N. K.; Kop'ev, V. A.; Kossyi, I. A.; Malykh, N. I.; Misakyan, M. A.; Taktakishvili, M. I.; Temchin, S. M.; Lee, Young Dong

    2007-07-15

    A conceptual design of a microwave gas-discharge plasma source is described. The possibility is considered of creating conditions under which microwave energy in the plasma resonance region would be efficiently converted into the energy of thermal and accelerated (fast) electrons. Results are presented from interferometric and probe measurements of the plasma density in a coaxial microwave plasmatron, as well as the data from probe measurements of the plasma potential and electron temperature. The dynamics of plasma radiation was recorded using a streak camera and a collimated photomultiplier. The experimental results indicate that, at relatively low pressures of the working gas, the nonlinear interaction between the microwave field and the inhomogeneous plasma in the resonance region of the plasmatron substantially affects the parameters of the ionized gas in the reactor volume.

  16. Microalgae as Sources of Carotenoids

    PubMed Central

    Guedes, Ana Catarina; Amaro, Helena M.; Malcata, Francisco Xavier

    2011-01-01

    Marine microalgae constitute a natural source of a variety of drugs for pharmaceutical, food and cosmetic applications—which encompass carotenoids, among others. A growing body of experimental evidence has confirmed that these compounds can play important roles in prevention (and even treatment) of human diseases and health conditions, e.g., cancer, cardiovascular problems, atherosclerosis, rheumatoid arthritis, muscular dystrophy, cataracts and some neurological disorders. The underlying features that may account for such favorable biological activities are their intrinsic antioxidant, anti-inflammatory and antitumoral features. In this invited review, the most important issues regarding synthesis of carotenoids by microalgae are described and discussed—from both physiological and processing points of view. Current gaps of knowledge, as well as technological opportunities in the near future relating to this growing field of interest, are also put forward in a critical manner. PMID:21731554

  17. Renewable Sources of Energy and Development.

    ERIC Educational Resources Information Center

    Diatta, Christian Sina

    1979-01-01

    Reviewed are the status of conventional sources of energy, prospects for the development of alternative sources of energy, and the consequences of that development on countries that are in the process of industrialization. (BT)

  18. Pesticide Information Sources in the United States.

    ERIC Educational Resources Information Center

    Alston, Patricia Gayle

    1992-01-01

    Presents an overview of electronic and published sources on pesticides. Includes sources such as databases, CD-ROMs, books, journals, brochures, pamphlets, fact sheets, hotlines, courses, electronic mail, and electronic bulletin boards. (MCO)

  19. Driver circuit for solid state light sources

    DOEpatents

    Palmer, Fred; Denvir, Kerry; Allen, Steven

    2016-02-16

    A driver circuit for a light source including one or more solid state light sources, a luminaire including the same, and a method of so driving the solid state light sources are provided. The driver circuit includes a rectifier circuit that receives an alternating current (AC) input voltage and provides a rectified AC voltage. The driver circuit also includes a switching converter circuit coupled to the light source. The switching converter circuit provides a direct current (DC) output to the light source in response to the rectified AC voltage. The driver circuit also includes a mixing circuit, coupled to the light source, to switch current through at least one solid state light source of the light source in response to each of a plurality of consecutive half-waves of the rectified AC voltage.

  20. High power millimeter wave source development program

    NASA Technical Reports Server (NTRS)

    George, T. V.

    1989-01-01

    High power millimeter wave sources for fusion program; ECH source development program strategy; and 1 MW, 140 GHz gyrotron experiment design philosophy are briefly outlined. This presentation is represented by viewgraphs only.

  1. Fluidic, Inc Minor New Source Permit Application

    EPA Pesticide Factsheets

    Documents related to the Minor New Source Review Permit for Fluidic, Inc, Salt River Pima-Maricopa, near Scottsdale, AZ. This is an application for a Tribal Minor New Source Review (NSR) Permit that is currently under review.

  2. THE FUTURE OF MICROBIAL SOURCE TRACKING STUDIES

    EPA Science Inventory

    Microbial source tracking (MST) is differentiated from traditional microbial water quality efforts by the need to identify the host species from which the bacteria originate, rather than necessarily identifying an individual point source. Despite recent advances in the developmen...

  3. 40 CFR 52.234 - Source surveillance.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS California § 52.234 Source surveillance. (a) Except in... stationary source in the State of California, except for those APCD's specified in paragraph (a) of...

  4. 40 CFR 52.234 - Source surveillance.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS California § 52.234 Source surveillance. (a) Except in... stationary source in the State of California, except for those APCD's specified in paragraph (a) of...

  5. Source water monitoring and biomonitoring systems

    EPA Science Inventory

    Presentation will provide background information on continuous source water monitoring using online toxicity monitors and cover various tools available. Conceptual and practical aspects of source water quality monitoring will be discussed.

  6. Problems with packaged sources in foreign countries

    SciTech Connect

    Abeyta, Cristy L; Matzke, James L; Zarling, John; Tompkin, J. Andrew

    2010-01-01

    The Global Threat Reduction Initiative's (GTRI) Off-Site Source Recovery Project (OSRP), which is administered by the Los Alamos National Laboratory (LANL), removes excess, unwanted, abandoned, or orphan radioactive sealed sources that pose a potential threat to national security, public health, and safety. In total, GTRI/OSRP has been able to recover more than 25,000 excess and unwanted sealed sources from over 825 sites. In addition to transuranic sources, the GTRI/OSRP mission now includes recovery of beta/gamma emitting sources, which are of concern to both the U.S. government and the International Atomic Energy Agency (IAEA). This paper provides a synopsis of cooperative efforts in foreign countries to remove excess and unwanted sealed sources by discussing three topical areas: (1) The Regional Partnership with the International Atomic Energy Agency; (2) Challenges in repatriating sealed sources; and (3) Options for repatriating sealed sources.

  7. Management of spent sealed radiation sources.

    PubMed

    Vicente, Roberto; Sordi, Gian-Maria; Hiromoto, Goro

    2004-05-01

    Spent or disused sealed radiation sources--no longer needed sources--may represent a risk of radiological accident or may be a target for criminal acts in countries where final disposal options are unavailable and where an increasing number of sources are being kept in extended storage. In developing countries, thousands of radium needles, teletherapy sources, oil well logging neutron sources, and miscellaneous industrial radioactive gauges are annually collected as waste and stored in research institutes. The objectives of the study described in this paper are to inventory such sources in Brazil, including those presently in use and those already collected as waste, and to design a dedicated repository where spent sources could be disposed of properly. The inventory of sources in Brazil and the concept of the repository are presented and its feasibility is discussed.

  8. Off-Site Source Recovery Project Overview.

    SciTech Connect

    Coel-Roback, Rebecca J.

    2016-09-29

    This report introduces the Off-Site Source Recovery project and gives a summary of domestic and international work. The mission of OSRP is to eliminate excess, unwanted, abandoned, or orphan radioactive sealed sources that pose a potential risk to health, safety, and national security. OSRP identifies and tracks disused sealed sources potentially requiring recovery, and performs special form encapsulation for sealed sources to simplify transportation.

  9. Open-source software: not quite endsville.

    PubMed

    Stahl, Matthew T

    2005-02-01

    Open-source software will never achieve ubiquity. There are environments in which it simply does not flourish. By its nature, open-source development requires free exchange of ideas, community involvement, and the efforts of talented and dedicated individuals. However, pressures can come from several sources that prevent this from happening. In addition, openness and complex licensing issues invite misuse and abuse. Care must be taken to avoid the pitfalls of open-source software.

  10. High-intensity source of extreme ultraviolet

    NASA Technical Reports Server (NTRS)

    Paresce, E.; Kumar, S.; Bowyer, S.

    1972-01-01

    High intensity ultraviolet radiation source was developed which is suitable for emission below 500 A. Source, useful for 100 to 1000 A range, is simple and inexpensive to construct, easy to operate, and very stable. Because of sufficiently intense output spectrum, source can be used with monochromator at wavelengths as low as 160 A.

  11. 46 CFR 120.310 - Power sources.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Power sources. 120.310 Section 120.310 Shipping COAST... PASSENGERS OR WITH OVERNIGHT ACCOMMODATIONS FOR MORE THAN 49 PASSENGERS ELECTRICAL INSTALLATION Power Sources and Distribution Systems § 120.310 Power sources. (a)(1) Each vessel that relies on electricity...

  12. 46 CFR 183.310 - Power sources.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Power sources. 183.310 Section 183.310 Shipping COAST...) ELECTRICAL INSTALLATION Power Sources and Distribution Systems § 183.310 Power sources. (a)(1) Each vessel that relies on electricity to power the following loads must be arranged so that the loads can...

  13. 46 CFR 129.310 - Power sources.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Power sources. 129.310 Section 129.310 Shipping COAST... Power Sources and Distribution Systems § 129.310 Power sources. (a)(1) Each vessel that relies on electricity to power the following loads must be arranged so that the loads can be energized from at least...

  14. 40 CFR 63.73 - Source.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 9 2011-07-01 2011-07-01 false Source. 63.73 Section 63.73 Protection... STANDARDS FOR HAZARDOUS AIR POLLUTANTS FOR SOURCE CATEGORIES Regulations Governing Compliance Extensions for Early Reductions of Hazardous Air Pollutants § 63.73 Source. (a) An alternative emission limitation...

  15. 30 CFR 57.4500 - Heat sources.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Heat sources. 57.4500 Section 57.4500 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND... Installation/construction/maintenance § 57.4500 Heat sources. Heat sources capable of producing...

  16. 40 CFR 52.234 - Source surveillance.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 3 2011-07-01 2011-07-01 false Source surveillance. 52.234 Section 52...) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS California § 52.234 Source surveillance. (a) Except in... emission data by sources. (1) Amador County APCD. (2) Bay Area AQMD. (3) Calaveras County APCD. (4)...

  17. 48 CFR 873.103 - Priority sources.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 48 Federal Acquisition Regulations System 5 2011-10-01 2011-10-01 false Priority sources. 873.103... SUPPLEMENTARY REGULATIONS SIMPLIFIED ACQUISITION PROCEDURES FOR HEALTH-CARE RESOURCES 873.103 Priority sources.... 46-48c) and FAR Subpart 8.7, there are no priority sources for the acquisition of...

  18. 40 CFR 52.2075 - Source surveillance.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 4 2010-07-01 2010-07-01 false Source surveillance. 52.2075 Section 52...) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS (CONTINUED) Rhode Island § 52.2075 Source surveillance... authority to require owners or operators of stationary sources to maintain records of, and...

  19. 40 CFR 52.2075 - Source surveillance.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 4 2011-07-01 2011-07-01 false Source surveillance. 52.2075 Section 52...) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS (CONTINUED) Rhode Island § 52.2075 Source surveillance... authority to require owners or operators of stationary sources to maintain records of, and...

  20. 40 CFR 52.1479 - Source surveillance.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 4 2011-07-01 2011-07-01 false Source surveillance. 52.1479 Section 52...) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS (CONTINUED) Nevada § 52.1479 Source surveillance. (a) The... adequate legally enforceable procedures for requiring owners or operators of stationary sources to...

  1. 40 CFR 52.12 - Source surveillance.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 3 2011-07-01 2011-07-01 false Source surveillance. 52.12 Section 52...) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS General Provisions § 52.12 Source surveillance. (a) Each subpart identifies the plan provisions for source surveillance which are disapproved, and sets forth...

  2. 40 CFR 52.794 - Source surveillance.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 3 2010-07-01 2010-07-01 false Source surveillance. 52.794 Section 52...) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS Indiana § 52.794 Source surveillance. (a) The... County sources specifically listed in Table 2 of 325 IAC 6-1-10.2 (§ 52.770(c)(57)); for pushing...

  3. 30 CFR 56.4500 - Heat sources.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Heat sources. 56.4500 Section 56.4500 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND... Installation/construction/maintenance § 56.4500 Heat sources. Heat sources capable of producing...

  4. 48 CFR 873.103 - Priority sources.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 48 Federal Acquisition Regulations System 5 2010-10-01 2010-10-01 false Priority sources. 873.103... SUPPLEMENTARY REGULATIONS SIMPLIFIED ACQUISITION PROCEDURES FOR HEALTH-CARE RESOURCES 873.103 Priority sources.... 46-48c) and FAR Subpart 8.7, there are no priority sources for the acquisition of...

  5. 40 CFR 52.1479 - Source surveillance.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 4 2010-07-01 2010-07-01 false Source surveillance. 52.1479 Section 52...) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS (CONTINUED) Nevada § 52.1479 Source surveillance. (a) The... adequate legally enforceable procedures for requiring owners or operators of stationary sources to...

  6. 40 CFR 63.73 - Source.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 9 2010-07-01 2010-07-01 false Source. 63.73 Section 63.73 Protection... STANDARDS FOR HAZARDOUS AIR POLLUTANTS FOR SOURCE CATEGORIES Regulations Governing Compliance Extensions for Early Reductions of Hazardous Air Pollutants § 63.73 Source. (a) An alternative emission limitation...

  7. 40 CFR 52.1077 - Source surveillance.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 4 2010-07-01 2010-07-01 false Source surveillance. 52.1077 Section 52...) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS (CONTINUED) Maryland § 52.1077 Source surveillance. (a... procedures for stationary sources to be periodically tested....

  8. 40 CFR 52.794 - Source surveillance.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 3 2011-07-01 2011-07-01 false Source surveillance. 52.794 Section 52...) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS Indiana § 52.794 Source surveillance. (a) The... County sources specifically listed in Table 2 of 325 IAC 6-1-10.2 (§ 52.770(c)(57)); for pushing...

  9. 40 CFR 52.130 - Source surveillance.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 3 2011-07-01 2011-07-01 false Source surveillance. 52.130 Section 52...) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS Arizona § 52.130 Source surveillance. (a) The... procedures for requiring sources in the Northern Arizona, Mohave-Yuma, Central Arizona, and Southeast...

  10. 40 CFR 52.1077 - Source surveillance.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 4 2011-07-01 2011-07-01 false Source surveillance. 52.1077 Section 52...) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS (CONTINUED) Maryland § 52.1077 Source surveillance. (a... procedures for stationary sources to be periodically tested....

  11. Source Region Identification Using Kernel Smoothing

    EPA Science Inventory

    As described in this paper, Nonparametric Wind Regression is a source-to-receptor source apportionment model that can be used to identify and quantify the impact of possible source regions of pollutants as defined by wind direction sectors. It is described in detail with an exam...

  12. Learning the Semantics of Structured Data Sources

    ERIC Educational Resources Information Center

    Taheriyan, Mohsen

    2015-01-01

    Information sources such as relational databases, spreadsheets, XML, JSON, and Web APIs contain a tremendous amount of structured data, however, they rarely provide a semantic model to describe their contents. Semantic models of data sources capture the intended meaning of data sources by mapping them to the concepts and relationships defined by a…

  13. Open Source: Everyone Becomes a Printer.

    ERIC Educational Resources Information Center

    Bruce, Bertram

    2000-01-01

    Discusses "open source": a method of distributing software in which programmers make available to all the actual text of their programs. Notes that this makes possible "open-source" writing in the same way that the printing press made possible "open-source" reading, enabling mass literacy. Examines implications of…

  14. Websites for Primary Sources and Civics Education

    ERIC Educational Resources Information Center

    Rulli, Daniel

    2005-01-01

    This article features a list of websites for primary sources and civics education. The World Wide Web has become an excellent source for facsimiles, images, and transcriptions of primary sources. As it would be impossible to provide a comprehensive list of all the sites, this annotated list highlights selective sites that provide access to…

  15. 30 CFR 57.4500 - Heat sources.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Installation/construction/maintenance § 57.4500 Heat sources. Heat sources capable of producing combustion... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Heat sources. 57.4500 Section 57.4500 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY...

  16. 30 CFR 56.4500 - Heat sources.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Installation/construction/maintenance § 56.4500 Heat sources. Heat sources capable of producing combustion... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Heat sources. 56.4500 Section 56.4500 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY...

  17. Recent progress in understanding QPO sources

    NASA Technical Reports Server (NTRS)

    Brainerd, J.; Lamb, F. K.; Shibazaki, N.

    1987-01-01

    New observational and theoretical results strongly suggest that QPOs in the fast, luminous sources are caused by oscillations in the luminosity of the X-ray star. They also explain why coherent pulsations at the stellar rotation frequency are so weak in these sources. Observations of weak red noise suggest that the luminosity oscillations in some sources are partially coherent.

  18. Recent progress in understanding QPO sources

    NASA Astrophysics Data System (ADS)

    Brainerd, J.; Lamb, F. K.; Shibazaki, N.

    1987-10-01

    New observational and theoretical results strongly suggest that QPOs in the fast, luminous sources are caused by oscillations in the luminosity of the X-ray star. They also explain why coherent pulsations at the stellar rotation frequency are so weak in these sources. Observations of weak red noise suggest that the luminosity oscillations in some sources are partially coherent.

  19. Development of Californium-252 Miniature Source Assemblies

    SciTech Connect

    Notspecified, N. A.

    2007-06-26

    The purpose of this CRADA between ORNL and lsotron, Inc. is to develop miniature californium-252 sources configured for remote handling that can be used in neutron brachytherapy for treatment of cancer. Brachytherapy places the · radioactive source at or near the site of the tumor, using a catheter. The CRADA ran from late 1999 through November 2005. The heart of a Cf-252 source is the radioactive core wire, which is sealed inside a metallic source capsule. Previous Cf-252 medical sources were based on a cermet wire with californium oxide dispersed in palladium, typically >1-mm diameter and <0.1% Cf-252 by weight. Previously, the standard medical source in the U.S. was the Applicator Tube (AT) source. 23-mm long, 2.8-mm diameter, with ~30 {micro}g of Cf-252, and which required manual loading into patients by medical staff. The goal of this work was to develop capabilities and technology to fabricate higher-intensity Cf-252 sources attached to a positioning cable, with overall diameter approaching that of exist ing photon (iridium-192) brachytherapy sources (i.e., ~1.1 mm). This work was successful in developing and demonstrating new technologies and procedures for the fabrication of miniaturized Cf-252 sources. CRADA-designed equipment reduced the wire diameters significantly (patent pending). Short wire segments were cut and successfully welded inside capsules meeting the miniaturization goals. A batch of seven prototype sources was prepared that met fabrication specifications. Although their neutron emissions were not maximized, they were still several times more intense than the previous AT sources. Very robust source-to-cable attachment methods were demonstrated (patent issued). A shipping canister was designed and built to contain the completed source assembly. lsotron designed and built a computer-controlled remote afterloader system to deliver the new sources for treatments.

  20. The HYPE Open Source Community

    NASA Astrophysics Data System (ADS)

    Strömbäck, Lena; Arheimer, Berit; Pers, Charlotta; Isberg, Kristina

    2013-04-01

    The Hydrological Predictions for the Environment (HYPE) model is a dynamic, semi-distributed, process-based, integrated catchment model (Lindström et al., 2010). It uses well-known hydrological and nutrient transport concepts and can be applied for both small and large scale assessments of water resources and status. In the model, the landscape is divided into classes according to soil type, vegetation and altitude. The soil representation is stratified and can be divided in up to three layers. Water and substances are routed through the same flow paths and storages (snow, soil, groundwater, streams, rivers, lakes) considering turn-over and transformation on the way towards the sea. In Sweden, the model is used by water authorities to fulfil the Water Framework Directive and the Marine Strategy Framework Directive. It is used for characterization, forecasts, and scenario analyses. Model data can be downloaded for free from three different HYPE applications: Europe (www.smhi.se/e-hype), Baltic Sea basin (www.smhi.se/balt-hype), and Sweden (vattenweb.smhi.se) The HYPE OSC (hype.sourceforge.net) is an open source initiative under the Lesser GNU Public License taken by SMHI to strengthen international collaboration in hydrological modelling and hydrological data production. The hypothesis is that more brains and more testing will result in better models and better code. The code is transparent and can be changed and learnt from. New versions of the main code will be delivered frequently. The main objective of the HYPE OSC is to provide public access to a state-of-the-art operational hydrological model and to encourage hydrologic expertise from different parts of the world to contribute to model improvement. HYPE OSC is open to everyone interested in hydrology, hydrological modelling and code development - e.g. scientists, authorities, and consultancies. The HYPE Open Source Community was initiated in November 2011 by a kick-off and workshop with 50 eager participants

  1. Source attribution of tropospheric ozone

    NASA Astrophysics Data System (ADS)

    Butler, T. M.

    2015-12-01

    Tropospheric ozone is a harmful pollutant with adverse effects on human health and ecosystems. As well as these effects, tropospheric ozone is also a powerful greenhouse gas, with an anthropogenic radiative forcing one quarter of that of CO2. Along with methane and atmospheric aerosol, tropospheric ozone belongs to the so-called Short Lived Climate forcing Pollutants, or SLCP. Recent work has shown that efforts to reduce concentrations of SLCP in the atmosphere have the potential to slow the rate of near-term climate change, while simultaneously improving public health and reducing crop losses. Unlike many other SLCP, tropospehric ozone is not directly emitted, but is instead influenced by two distinct sources: transport of air from the ozone-rich stratosphere; and photochemical production in the troposphere from the emitted precursors NOx (oxides of nitrogen), CO (Carbon Monoxide), and VOC (volatile organic compounds, including methane). Better understanding of the relationship between ozone production and the emissions of its precursors is essential for the development of targeted emission reduction strategies. Several modeling methods have been employed to relate the production of tropospheric ozone to emissions of its precursors; emissions perturbation, tagging, and adjoint sensitivity methods all deliver complementary information about modelled ozone production. Most studies using tagging methods have focused on attribution of tropospheric ozone production to emissions of NOx, even though perturbation methods have suggested that tropospheric ozone is also sensitive to VOC, particularly methane. In this study we describe the implementation into a global chemistry-climate model of a scheme for tagging emissions of NOx and VOC with an arbitrary number of labels, which are followed through the chemical reactions of tropospheric ozone production in order to perform attribution of tropospehric ozone to its emitted precursors. Attribution is performed to both

  2. Star pinch scalable EUV source

    NASA Astrophysics Data System (ADS)

    McGeoch, Malcolm W.; Pike, Charles T.

    2003-06-01

    A new direct discharge source of 13.5nm radiation addresses the heat load problem by creating the plasma remote from all surfaces. The plasma is initially formed at the intersection of many pulsed xenon beamlets. Further heating is then applied via a high current pulse to induce efficient radiation from Xe10+ ions. The plasma is compact, with a single pulse FWHM diameter of 0.7mm and length of 3mm. It is positionally stable, as illustrated by re-imaging onto a fluorescent screen sensitive to EUV and time-integrating over 250 pulses. In this mode the averaged FWHM is 0.9mm. The conversion efficiency from stored electrical energy to radiation within 2π sterad and 2% bandwidth at 13.5nm is currently 0.55%, using xenon. Power is delivered to the plasma by a solid state-switched modulator operated at a stored energy of 25J of which 10J is dissipated in the plasma plus circuit, and 15J is recovered. The EUV output in 2% bandwidth at 13.5nm is 9mJ/sterad. Repetition rate scaling of the star pinch EUV source to 1kHz there is negligible electrode erosion at 106 pulses. This is possible because the cathode for the main heating discharge is distributed into 24-fold parallel hollow cathodes, with a combined operational surface aera of approximately 20cm2. The anode is similarly distributed. The walls facing the plasma are 22mm distant from it and when scaled to 6kHz will see a heat load of less than 1kWcm-2. The cathode electrode is then expected to receive a heat load of less than 500W cm-2. The plasma is expected to clear between pulses and be reproducible at frequencies up to at least 10kHz, at which rate the usable EUV power available at a second focus, assuming colleciton in 2sterad, is predicted to be more than 80W. The star pinch has properties that favor long life and appears to scale to the 50-100W powers needed for high throughput lithography.

  3. Source detection with the scaling index method.

    NASA Astrophysics Data System (ADS)

    Wiedemann, G.; Scheingraber, H.; Voges, W.

    The purpose of source detection algorithms in general is to distinguish between sources and non-significant background fluctuations. Most algorithms introduce an artificial partition of the event space by use of sliding windows. The procedure proposed here uses a natural partition given by the events themselves. The scaling index formalism assigns a scalar parameter to every event which can be classified by means of distribution theory as belonging to the background or to a source. No assumptions about the source geometry are necessary making the formalism most sensitive to the detection of extended irregular sources.

  4. From reactors to long pulse sources

    SciTech Connect

    Mezei, F. |

    1995-12-31

    We will show, that by using an adapted instrumentation concept, the performance of a continuous source can be emulated by one switch on in long pulses for only about 10% of the total time. This 10 fold gain in neutron economy opens up the way for building reactor like sources with an order of magnitude higher flux than the present technological limits. Linac accelerator driven spallation lends itself favorably for the realization of this kind of long pulse sources, which will be complementary to short pulse spallation sources, the same way continuous reactor sources are.

  5. Low Power Polysilicon Sources for IR Applications

    NASA Technical Reports Server (NTRS)

    Das, N. C.; Jhabvala, M.; Shu, P.

    1998-01-01

    We have designed and fabricated polysilicon thin film infrared (IR) sources by micromachining technology. These sources are made with a lightly doped middle region for light emission and heavy doping of the supporting legs. The sources are fabricated on a 10 mm thick, low temperature process parameters in the fabrication of these silicon dioxide layer. Different doping levels were used to achieve various source resistances. From the power requirement to reach the required light emission versus source resistance curve it is seen that there exists a resistance value which minimizes the necessary input power.

  6. Thulium heat sources for space power application

    NASA Astrophysics Data System (ADS)

    Alderman, C. J.

    1992-10-01

    Reliable electrical power supplies for use in transportation and remote systems will be an important part of space exploration activities on planet surfaces. A potential power source is available through the use of thulium, a rare earth metal. Heat sources can be produced by neutron activation of naturally occurring thulium (Tm-169) targets in the base station nuclear power reactor. The resulting Tm-170 heat sources can be used in thermoelectric generators to power instrumentation and telecommunications systems located at remote sites. Combined with a dynamic Sterling or Brayton cycle conversion system, the heat source can power a lightweight electrical source for rovers or other surface transportation systems.

  7. Ion source based on the cathodic arc

    DOEpatents

    Sanders, D.M.; Falabella, S.

    1994-02-01

    A cylindrically symmetric arc source to produce a ring of ions which leave the surface of the arc target radially and are reflected by electrostatic fields present in the source to a point of use, such as a part to be coated, is described. An array of electrically isolated rings positioned in the source serves the dual purpose of minimizing bouncing of macroparticles and providing electrical insulation to maximize the electric field gradients within the source. The source also includes a series of baffles which function as a filtering or trapping mechanism for any macroparticles. 3 figures.

  8. Ion source based on the cathodic arc

    DOEpatents

    Sanders, David M.; Falabella, Steven

    1994-01-01

    A cylindrically symmetric arc source to produce a ring of ions which leave the surface of the arc target radially and are reflected by electrostatic fields present in the source to a point of use, such as a part to be coated. An array of electrically isolated rings positioned in the source serves the dual purpose of minimizing bouncing of macroparticles and providing electrical insulation to maximize the electric field gradients within the source. The source also includes a series of baffles which function as a filtering or trapping mechanism for any macroparticles.

  9. Optical Characteristics of Astrometric Radio Sources OCARS

    NASA Astrophysics Data System (ADS)

    Malkin, Z.

    2013-04-01

    In this paper, the current status of the catalog of Optical Characteristics of Astrometric Radio Sources OCARS is presented. The catalog includes radio sources observed in various astrometric and geodetic VLBI programs in 1979-2012. For these sources the physical object type, redshift and visual or infrared magnitude is given when available. Detailed comments are provided when some problems with published data were encountered. Since the first version created in December 2007, the catalog is continuously developed and expanded in respect to inclusion of new radio sources and addition of new or correction of old astrophysical data. Several sources of information are used for OCARS. The main of them are the NASA/IPAC Extragalactic Database (NED) and SIMBAD astronomical databases. Besides several astronomical journals and arXiv depository are regularly monitored, so that new data is included in OCARS just after publication. The redshift for about 150 sources have been determined from dedicated optical spectroscopic observations. As of October 2012, OCARS catalog includes 7173 radio sources. 3898 sources have known redshift, and 4860 sources have known magnitude. In 2009, it was used as a supplement material to the ICRF2. The list of radio sources with a good observational history but lacking astrophysical information is provide for planning of optical observations of the most important astrometric sources. The OCARS catalog is updated, in average every several weeks and is available at http://www.gao.spb.ru/english/as/ac_vlbi/ocars.txt.

  10. Nonradiating electromagnetic sources in a nonuniform medium.

    PubMed

    Nikolova, Natalia K; Rickard, Yotka S

    2005-01-01

    Nonradiating electromagnetic sources are sources whose field is identically zero outside of their volume. They are undetectable unless the observation point is in direct contact with them. They are the basis of the theory of source equivalence, which studies the field invariance with respect to source transformations. In this work, we focus on the equivalent source transformations in a nonuniform medium and the implications in the theory of the electromagnetic vector potentials. We identify three types of nonradiating sources. Subsequently, we define the mathematical transformations of the sources, which preserve the field outside of their support (source invariance). We give complimentary expressions, which preserve the field inside the source support as well. We show that the nonuniqueness of the electromagnetic potentials is due to the nonunique solution to the inverse problem. The well known field gauge invariance follows from its source invariance. Also, the gauge-invariant transformation appears to be just one possibility in an infinite set of field-invariant vector-potential representations all related to the respective equivalent source transformations.

  11. SANSPOL at a pulsed source.

    SciTech Connect

    Bleuel, M.; Lang, E.; Krist, T.; Wagner, W.; Lal, J.; Intense Pulsed Neutron Source; Hahn Meitner Inst.; PSI

    2007-07-15

    Neutron polarization has not been implemented successfully on a time-of-flight small angle neutron scattering (TOF-SANS) machine to this date anywhere in the world. Designing a suitable one for the small angle scattering instrument (SASI) at IPNS, and implementing it, is an important first on a pulsed source. To achieve this, the installation of a solid-state supermirror-based polarizer, a gradient field adiabatic spin flipper, and a new collimator package were required. A polarizing solid-state bender without adsorbing layers, designed to transmit one polarized spin state and reflect the other has been purchased from Neutron Optics Berlin (NOB). By placing this package upstream of the collimation only the transmitted spin-state passes through to the sample. The polarization achieved with this technique up to now is 80% for neutrons in a wavelength range of 3-8 Angstroms and 67% for larger wavelengths. The polarizer is placed on a linear translator so it can be easily removed from the beam, when regular SANS measurements are desired. The first experimental results from a two-phase CuNiFe alloy sample are reported here.

  12. Mars Spark Source Prototype Developed

    NASA Technical Reports Server (NTRS)

    Eichenberg, Dennis J.; Lindamood, Glenn R.; VanderWal, Randall L.; Weiland, Karen J.

    2000-01-01

    The Mars Spark Source Prototype (MSSP) hardware was developed as part of a proof of concept system for the detection of trace metals such as lead, cadmium, and arsenic in Martian dusts and soils. A spark discharge produces plasma from a soil sample, and detectors measure the optical emission from metals in the plasma to identify and quantify them. Trace metal measurements are vital in assessing whether or not the Martian environment will be toxic to human explorers. The current method of x-ray fluorescence can yield concentrations of major species only. Other instruments are incompatible with the volume, weight, and power constraints for a Mars mission. The new instrument will be developed primarily for use in the Martian environment, but it would be adaptable for terrestrial use in environmental monitoring. The NASA Glenn Research Center at Lewis Field initiated the development of the MSSP as part of Glenn's Director's Discretionary Fund project for the Spark Analysis Detection of Trace Metal Species in Martian Dusts and Soils. The objective of this project is to develop and demonstrate a compact, sensitive optical instrument for the detection of trace hazardous metals in Martian dusts and soils.

  13. Information sources for noun learning.

    PubMed

    Kako, Edward

    2005-03-04

    Why are some words easier to learn than others? And what enables the eventual learning of the more difficult words? These questions were addressed for nouns using a paradigm in which adults were exposed to naturalistic maternal input that was manipulated to simulate access to several different information sources, both alone and in combination: observation of the extralinguistic contexts in which the target word was used, the words that co-occurred with the target word, and the target word's syntactic context. Words that were not accurately identified from observation alone were both abstract (e.g., music) and concrete (e.g., tail). Whether a noun could be learned from observation depended on whether it labeled a basic-level object category (BLOC). However, the difference between BLOC labels and non-BLOC labels was eliminated when observation was supplemented with linguistic context. Thus, although BLOC labels can be learned from observation alone, non-BLOC labels require richer linguistic context. These findings support a model of vocabulary growth in which an important role is played by changes in the information to which learners have access.

  14. Proposals for synchrotron light sources

    SciTech Connect

    Teng, L.C.

    1985-06-01

    Ever since it was first applied in the 1960's synchrotron radiation from an accelerating electron beam has been gaining popularity as a powerful tool for research and development in a wide variety of fields of science and technology. By now there are some 20 facilities operating either parasitically or dedicatedly for synchrotron radiation research in different parts of the world. In addition there are another 20 facilities either in construction or in various stages of proposal and design. The experiences gained from the operating facilities and the recent development of insertion devices such as wigglers and undulators as radiation sources led to a new set of requirements on the design of synchrotron radiation storage rings for optimum utility. The surprisingly uniform applicability and unanimous acceptance of these criteria give assurance that they are indeed valid criteria derived form mature considerations and experiences. Instead of describing the design of each of these new facilities it is, thus, more effective to discuss these desirable design features and indicate how they are incorporated in the design using machines listed as examples. 9 refs., 7 figs., 2 tabs.

  15. Advanced Light Source elliptical wiggler

    NASA Astrophysics Data System (ADS)

    Hoyer, E.; Akre, J.; Humphries, D.; Marks, S.; Minamihara, Y.; Pipersky, P.; Plate, D.; Schlueter, R.

    1995-02-01

    A 3.5-m-long elliptical wiggler, optimized to produce elliptically polarized light in the 50 eV to 10 keV range, is currently under design and construction at the Advanced Light Source at Lawrence Berkeley Laboratory. Calculations of spectral performance show that the flux of circularly polarized photons exceeds 1013 photons/s over the 50 eV to 10 keV operating range for current of 0.4 A and 1.5 GeV electron energy. This device features vertical and horizontal magnetic structures of 14 and 141/2 periods, respectively. The period length is 20.0 cm. The vertical structure is a hybrid permanent magnet design with tapered pole tips that produce a peak field of 2.0 T. The horizontal structure is an iron core electromagnetic design, shifted longitudinally 1/4 period, that is tucked between the upper and lower vertical magnetic structure sections. A maximum peak oscillating field of 0.095 T at a frequency up to 1 Hz will be achieved by excitation of the horizontal poles with a trapezoidal current waveform. The vacuum chamber is an unconventional design that is removable from the magnetic structure, after magnetic measurements, for UHV processing. The chamber is fabricated from non-magnetic stainless steel to minimize the effects of eddy currents. Device design is presented.

  16. Investigation of serendipitious WFC sources

    NASA Technical Reports Server (NTRS)

    Robinson, Edward L.

    1993-01-01

    The serendipitious WFC sources under investigation, i.e., those which just happened to lie in the field of view while another object was being studied, were disappointing. The integration times were chosen to suit the primary target not the serendipitous targets. UX UMa, CZ Ori, BI Ori, WX Cet and AR And were not detected. A long (approximately 17 ksec) pointed observation of UX Uma (PI Wood) has since been carried out (February 1993) and the data is expected shortly. The other observations were much more successful. V471 Tau was observed with the WFC for 6.5 hrs with the S1 filter and 1.1 hrs with the S2b filter. It was easily detected with a count rate of 0.03 cps in the S1 filter and 0.15 cps in the S2b filter. The oscillations were seen, even before the data was folded, as was expected from preliminary results from the survey (Barstow et al. 1992). The pointed observations provide a much better phase coverage of the oscillations than did the survey data where the coverage was sparse. These data will be presented in a paper with the PSPC data (PI's Robinson and Shipman) and the pulse profiles in the different wavelengths will be compared.

  17. Medical diagnostic applications and sources.

    PubMed

    Whittingham, T A

    2007-01-01

    The ways in which ultrasound is used in medical diagnosis are reviewed, with particular emphasis on the ultrasound source (probe) and implications for acoustic exposure. A brief discussion of the choice of optimum frequency for various target depths is followed by a description of the general features of diagnostic ultrasound probes, including endo-probes. The different modes of diagnostic scanning are then discussed in turn: A-mode, M-mode, B-mode, three-dimensional (3D) and 4D scanning, continuous wave (CW) Doppler, pulse-wave spectral Doppler and Doppler imaging. Under the general heading of B-mode imaging, there are individual descriptions of the principles of chirps and binary codes, B-flow, tissue harmonic imaging and ultrasound contrast agent-specific techniques. Techniques for improving image quality within the constraints of real-time operation are discussed, including write zoom, parallel beam forming, spatial compounding and multiple zone transmission focusing, along with methods for reducing slice thickness. At the end of each section there is a summarising comment on the basic features of the acoustic output and its consequences for patient safety.

  18. 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.

  19. Economics of alternative energy sources.

    PubMed

    Ryle, M

    1977-05-12

    An important part of the oil and natural gas at present consumed in the UK is used for the heating of buildings, a demand which shows large diurnal, day-to-day and annual fluctuations. The replacement of this energy by nuclear-generated electricity, as at present envisaged, would require the construction of some 250 GW of additional capacity by the end of the century, a progamme which does not seem feasible. By incorporating relatively cheap, short term storage in the form of low-grade heat, the generating capacity required to fulfil peak demand could be reduced by more than 50%. As soon as such storage is provided, however, other sources of energy become viable and attractive alternatives, and the UK is well situated to make use of wind, wave, and tidal power. It seems likely that the value of North Sea oil/gas reserves as feedstock to the chemical industry will rise sufficiently to make an early reduction in their consumption as fuel of great economic importance.

  20. CMBACT: CMB from ACTive sources

    NASA Astrophysics Data System (ADS)

    Pogosian, Levon; Vachaspati, Tanmay

    2011-06-01

    This code is based on the cosmic string model described in this paper by Pogosian and Vachaspati, as well as on the CMBFAST code created by Uros Seljak and Matias Zaldarriaga. It contains an integrator for the vector contribution to the CMB temperature and polarization. The code is reconfigured to make it easier to use with or without active sources. To produce inflationary CMB spectra one simply sets the string tension to zero (gmu=0.0d0). For a non-zero value of tension only the string contribution is calculated. An option is added to randomize the directions of velocities of consolidated segments as they evolve in time. In the original segment model, which is still the default version (irandomv=0), each segment is given a random velocity initially, but then continues to move in a straight line for the rest of its life. The new option (irandomv=1) allows to additionally randomize velocities of each segment at roughly each Hubble time. However, the merits of this new option are still under investigation. The default version (irandomv=0) is strongly recommended, since it actually gives reasonable unequal time correlators. For each Fourier mode, k, the string stress-energy components are now evaluated on a time grid sufficiently fine for that k.

  1. Discharge-pumped XUV source

    NASA Astrophysics Data System (ADS)

    Schmidt, Jiri; Kolacek, Karel; Straus, Jaroslav; Frolov, Oleksandr

    2016-09-01

    We have built two experimental devices (CAPEX and CAPEX-U) working as XUV sources, which are based on the fast, pinching capillary discharge. On both these devices we have observed lasing at 46.9 nm (Ne-like Ar line). However, besides lasing at the above mentioned relatively long wavelength, they are also used for testing a possibility of amplification at the wavelengths below 20 nm that have more practical applications. Particularly, at present nitrogen-filled capillary (?4 mm x 90 mm) discharge is studied for the development of XUV (soft X-ray) laser based on recombination pumping scheme: the fully stripped nitrogen nuclei recombine to hydrogen-like atoms, where Balmer-alpha transition (wavelength 13.4 nm) is - according to theoretical predictions - capable of creating population inversion. The modified electrical parameters (peak current 60 kA with quarter period of 45 ns) meet the necessary theoretical conditions. The only question remains, if suitable pre-pulse can suppress the capillary-wall-ablation, which in all presently known cases has quashed the amplification. In this paper the recent results obtained from both these discharge systems (argon-, nitrogen-filled capillaries) will be presented. Acknowledgement: This work was performed under auspices and with the support of the Grant Agency of the Czech Republic (Contract 14-29772S) and of the Ministry of Education, Youth, and Sports of the Czech Republic (INGO contract LG15013).

  2. International workshop on cold neutron sources

    SciTech Connect

    Russell, G.J.; West, C.D. )

    1991-08-01

    The first meeting devoted to cold neutron sources was held at the Los Alamos National Laboratory on March 5--8, 1990. Cosponsored by Los Alamos and Oak Ridge National Laboratories, the meeting was organized as an International Workshop on Cold Neutron Sources and brought together experts in the field of cold-neutron-source design for reactors and spallation sources. Eighty-four people from seven countries attended. Because the meeting was the first of its kind in over forty years, much time was spent acquainting participants with past and planned activities at reactor and spallation facilities worldwide. As a result, the meeting had more of a conference flavor than one of a workshop. The general topics covered at the workshop included: Criteria for cold source design; neutronic predictions and performance; energy deposition and removal; engineering design, fabrication, and operation; material properties; radiation damage; instrumentation; safety; existing cold sources; and future cold sources.

  3. The Commercial Open Source Business Model

    NASA Astrophysics Data System (ADS)

    Riehle, Dirk

    Commercial open source software projects are open source software projects that are owned by a single firm that derives a direct and significant revenue stream from the software. Commercial open source at first glance represents an economic paradox: How can a firm earn money if it is making its product available for free as open source? This paper presents the core properties of com mercial open source business models and discusses how they work. Using a commercial open source approach, firms can get to market faster with a superior product at lower cost than possible for traditional competitors. The paper shows how these benefits accrue from an engaged and self-supporting user community. Lacking any prior comprehensive reference, this paper is based on an analysis of public statements by practitioners of commercial open source. It forges the various anecdotes into a coherent description of revenue generation strategies and relevant business functions.

  4. Source-space ICA for EEG source separation, localization, and time-course reconstruction.

    PubMed

    Jonmohamadi, Yaqub; Poudel, Govinda; Innes, Carrie; Jones, Richard

    2014-11-01

    We propose source-space independent component analysis (ICA) for separation, tomography, and time-course reconstruction of EEG and MEG source signals. Source-space ICA is based on the application of singular value decomposition and ICA on the neuroelectrical signals from all brain voxels obtained post minimum-variance beamforming of sensor-space EEG or MEG. We describe the theoretical background and equations, then evaluate the performance of this technique in several different situations, including weak sources, bilateral correlated sources, multiple sources, and cluster sources. In this approach, tomographic maps of sources are obtained by back-projection of the ICA mixing coefficients into the source-space (3-D brain template). The advantages of source-space ICA over the popular alternative approaches of sensor-space ICA together with dipole fitting and power mapping via minimum-variance beamforming are demonstrated. Simulated EEG data were produced by forward head modeling to project the simulated sources onto scalp sensors, then superimposed on real EEG background. To illustrate the application of source-space ICA to real EEG source reconstruction, we show the localization and time-course reconstruction of visual evoked potentials. Source-space ICA is superior to the minimum-variance beamforming in the reconstruction of multiple weak and strong sources, as ICA allows weak sources to be identified and reconstructed in the presence of stronger sources. Source-space ICA is also superior to sensor-space ICA on accuracy of localization of sources, as source-space ICA applies ICA to the time-courses of voxels reconstructed from minimum-variance beamforming on a 3D scanning grid and these time-courses are optimally unmixed via the beamformer. Each component identified by source-space ICA has its own tomographic map which shows the extent to which each voxel has contributed to that component.

  5. Commentary: Advances in Research on Sourcing-Source Credibility and Reliable Processes for Producing Knowledge Claims

    ERIC Educational Resources Information Center

    Chinn, Clark A.; Rinehart, Ronald W.

    2016-01-01

    In our commentary on this excellent set of articles on "Sourcing in the Reading Process," we endeavor to synthesize the findings from the seven articles and discuss future research. We discuss significant contributions related to source memory, source evaluation, use of sources in action and belief, integration of information from…

  6. Binding an Event to Its Source at Encoding Improves Children's Source Monitoring

    ERIC Educational Resources Information Center

    Roberts, Kim P.; Evans, Angela D.; Duncanson, Sara

    2016-01-01

    Children learn information from a variety of sources and often remember the content but forget the source. Whereas the majority of research has focused on retrieval mechanisms for such difficulties, the present investigation examines whether the way in which sources are "encoded" influences future source monitoring. In Study 1, 86…

  7. 10 CFR 35.67 - Requirements for possession of sealed sources and brachytherapy sources.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 1 2010-01-01 2010-01-01 false Requirements for possession of sealed sources and brachytherapy sources. 35.67 Section 35.67 Energy NUCLEAR REGULATORY COMMISSION MEDICAL USE OF BYPRODUCT... possession of a sealed source shall— (1) Test the source for leakage before its first use unless the...

  8. 10 CFR 35.67 - Requirements for possession of sealed sources and brachytherapy sources.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 10 Energy 1 2012-01-01 2012-01-01 false Requirements for possession of sealed sources and brachytherapy sources. 35.67 Section 35.67 Energy NUCLEAR REGULATORY COMMISSION MEDICAL USE OF BYPRODUCT... possession of a sealed source shall— (1) Test the source for leakage before its first use unless the...

  9. 10 CFR 35.67 - Requirements for possession of sealed sources and brachytherapy sources.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 10 Energy 1 2011-01-01 2011-01-01 false Requirements for possession of sealed sources and brachytherapy sources. 35.67 Section 35.67 Energy NUCLEAR REGULATORY COMMISSION MEDICAL USE OF BYPRODUCT... possession of a sealed source shall— (1) Test the source for leakage before its first use unless the...

  10. 10 CFR 35.67 - Requirements for possession of sealed sources and brachytherapy sources.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 10 Energy 1 2013-01-01 2013-01-01 false Requirements for possession of sealed sources and brachytherapy sources. 35.67 Section 35.67 Energy NUCLEAR REGULATORY COMMISSION MEDICAL USE OF BYPRODUCT... possession of a sealed source shall— (1) Test the source for leakage before its first use unless the...

  11. 10 CFR 35.67 - Requirements for possession of sealed sources and brachytherapy sources.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 10 Energy 1 2014-01-01 2014-01-01 false Requirements for possession of sealed sources and brachytherapy sources. 35.67 Section 35.67 Energy NUCLEAR REGULATORY COMMISSION MEDICAL USE OF BYPRODUCT... possession of a sealed source shall— (1) Test the source for leakage before its first use unless the...

  12. Approaching Source Illiteracy, or How a Source Is Like a Frog

    ERIC Educational Resources Information Center

    Murphy, Nora G.

    2016-01-01

    Just as fluency isn't knowing every word in a language, source literacy isn't knowing every source. It is, instead, the ability to interpret from context, to know what to ask, to read the clues, and to use the understanding brought from knowing about other sources. A person fluent in source literacy is able to do this automatically, the way you…

  13. Light Sources and Ballast Circuits

    NASA Astrophysics Data System (ADS)

    Yorifuji, Takashi; Sakai, Makoto; Yasuda, Takeo; Maehara, Akiyoshi; Okada, Atsunori; Gouriki, Takeshi; Mannami, Tomoaki

    discharge models were reported. Further, studies on ultra high-pressure mercury lamps as light sources for projectors are becoming the mainstream of HID lamp related researches. For high-pressure sodium lamps, many studies on plant growing and pest control utilizing low insect attracting aspects were also reported in 2006. Additionally, for discharge lamps, the minimum sustaining electric power for arc tubes employed in electrode-less compact fluorescent lamps was investigated. For Hg-free rare-gas fluorescent lamps, a luminance of 10,000cd/m2 was attained by a 1 meter-long external duplex spiral electrode prototype using Xe/Ne barrier discharge. As to startup circuits, the commercialization of energy saving and high value added products mainly associated with fluorescent lamps and HID lamps are becoming common. Further, the miniaturization of startup circuits for self electronic-ballasted lamps has advanced. Speaking of the overall light sources and startup circuits in 2006 and with the enforcement of RoHS in Europe in July, the momentum toward hazardous substance-free and energy saving initiatives has been enhanced from the perspective of protecting the global environment. It is anticipated that similar restrictions will be globally enforced in the future.

  14. Neuronal Source of Plasma Dopamine

    PubMed Central

    Goldstein, David S.; Holmes, Courtney

    2008-01-01

    BACKGROUND Determinants of plasma norepinephrine (NE) and epinephrine concentrations are well known; those of the third endogenous catecholamine, dopamine (DA), remain poorly understood. We tested in humans whether DA enters the plasma after corelease with NE during exocytosis from sympathetic noradrenergic nerves. METHODS We reviewed plasma catecholamine data from patients referred for autonomic testing and control subjects under the following experimental conditions: during supine rest and in response to orthostasis; intravenous yohimbine (YOH), isoproterenol (ISO), or glucagon (GLU), which augment exocytotic release of NE from sympathetic nerves; intravenous tri-methaphan (TRI) or pentolinium (PEN), which decrease exocytotic NE release; or intravenous tyramine (TYR), which releases NE by nonexocytotic means. We included groups of patients with pure autonomic failure (PAF), bilateral thoracic sympathectomies (SNS-x), or multiple system atrophy (MSA), since PAF and SNS-x are associated with noradrenergic denervation and MSA is not. RESULTS Orthostasis, YOH, ISO, and TYR increased and TRI/PEN decreased plasma DA concentrations. Individual values for changes in plasma DA concentrations correlated positively with changes in NE in response to orthostasis (r =0.72, P <0.0001), YOH (r = 0.75, P < 0.0001), ISO (r = 0.71, P < 0.0001), GLU (r = 0.47, P = 0.01), and TYR (r = 0.67, P < 0.0001). PAF and SNS-x patients had low plasma DA concentrations. We estimated that DA constitutes 2%– 4% of the catecholamine released by exocytosis from sympathetic nerves and that 50%–90% of plasma DA has a sympathoneural source. CONCLUSIONS Plasma DA is derived substantially from sympathetic noradrenergic nerves. PMID:18801936

  15. A Usual Source of Care

    PubMed Central

    DeVoe, Jennifer E.; Petering, Ryan; Krois, Lisa

    2016-01-01

    Objectives To examine the separate and combined effects of having health insurance and a usual source of care (USC) on access to healthcare for low-income children and to determine if one or the other is superior in ensuring better access to necessary services. Methods We conducted cross-sectional, multivariable analyses of data from a mail-return survey of Oregon’s food stamp program. Results from 2681 completed surveys were weighted back to a population of 84,087 families with adjustments for oversampling techniques and nonresponse. Results Among low-income Oregon children, those with health insurance and a USC reported the best access to healthcare. In multivariable comparisons to this reference group, insured children without a USC had higher rates of unmet medical need [odds ratio (OR) = 2.18; 95% confidence interval (CI): 1.27–3.73]; no doctor visits in 12 months (OR = 6.77; 95% CI: 3.80–12.06); and problems obtaining specialty care (OR = 4.12; 95% CI: 1.59–10.68). Similarly, having a USC but not health insurance was associated with an even higher likelihood of unmet medical needs (OR = 4.33; 95% CI: 2.85–6.57); as well as unmet prescription needs (OR = 2.64, 95% CI: 1.77–3.94), and problems obtaining dental care (OR = 4.83; 95% CI: 3.31–7.06). Conclusions Incremental policy solutions are being proposed that focus on either health insurance coverage for children or expanded access to primary care. However, neither approach displaces the need for the other. The effects of a USC and health insurance, together, are additive predictors of the likelihood that children have optimal access to necessary healthcare services. PMID:18815525

  16. The First Sources of Light

    NASA Astrophysics Data System (ADS)

    Loeb, Avi

    2011-09-01

    Looking deep into the Universe through powerful telescopes, we can see images of the Universe when it was younger because of the finite time it takes light to travel to us from distant sources. Existing data sets include an image of the Universe when it was 0.4 million years old (in the form of the cosmic microwave background), as well as images of individual galaxies when the Universe was older than a billion years. But there is a serious challenge: in between these two epochs was a period when the Universe was dark, stars had not yet formed, and the cosmic microwave background no longer traced the distribution of matter. And this is precisely the most interesting period, when the primordial soup evolved into the rich zoo of objects we now see. The observers are moving ahead along several fronts. The first involves the construction of large infrared telescopes on the ground and in space, that will provide us with new photos of the first galaxies. Current plans include ground-based telescopes which are 24-42 meter in diameter, and NASA's successor to the Hubble Space Telescope, called the James Webb Space Telescope. In addition, several observational groups around the globe are constructing radio arrays that will be capable of mapping the three-dimensional distribution of cosmic hydrogen in the infant Universe. These arrays are aiming to detect the long-wavelength (redshifted 21-cm) radio emission from hydrogen atoms. The images from these antenna arrays will reveal how the non-uniform distribution of neutral hydrogen evolved with cosmic time and eventually was extinguished by the ultra-violet radiation from the first galaxies. Theoretical research has focused in recent years on predicting the expected signals for the above instruments and motivating these ambitious observational projects.

  17. Heat sources for mantle plumes

    NASA Astrophysics Data System (ADS)

    Beier, C.; Rushmer, T.; Turner, S. P.

    2008-06-01

    Melting anomalies in the Earth's upper mantle have often been attributed to the presence of mantle plumes that may originate in the lower mantle, possibly from the core-mantle boundary. Globally, mantle plumes exhibit a large range in buoyancy flux that is proportional to their temperature and volume. Plumes with higher buoyancy fluxes should have higher temperatures and experience higher degrees of partial melting. This excess heat in mantle plumes could reflect either (1) an enrichment of the heat-producing elements (HPE: U, Th, K) in their mantle source leading to an increase of heat production by radioactive decay, (2) material transport from core to mantle (either advective or diffusive), or (3) conductive heat transport across the core-mantle boundary. The advective/diffusive transport of heat may result in a physical contribution of material from the core to the lower mantle. If core material is incorporated into the lower mantle, mantle plumes with a higher buoyancy flux should have higher core tracers, e.g., increased 186Os, 187Os, and Fe concentrations. Geophysical and dynamic modeling indicate that at least Afar, Easter, Hawaii, Louisville, and Samoa may all originate at the core-mantle boundary. These plumes encompass the whole range of known buoyancy fluxes from 0.9 Mg s-1 (Afar) to 8.7 Mg s-1 (Hawaii), providing evidence that the buoyancy flux is largely independent of other geophysical parameters. In an effort to explore whether the heat-producing elements are the cause of excess heat we looked for correlations between fractionation-corrected concentrations of the HPE and buoyancy flux. Our results suggest that there is no correlation between HPE concentrations and buoyancy flux (with and without an additional correction for variable degrees of partial melting). As anticipated, K, Th, and U are positively correlated with each other (e.g., Hawaii, Iceland, and Galapagos have significantly lower concentrations than, e.g., Tristan da Cunha, the Canary

  18. Synchro-Compton emission from superluminal sources

    NASA Technical Reports Server (NTRS)

    Marscher, Alan P.

    1987-01-01

    The application of synchro-Compton theory to real compact radio sources, the question of a self-Compton origin of the X-rays in radio-loud quasars and active galactic nuclei, and the phenomenology of superluminal motion are discussed in a review of research concerning synchro-Compton emission from superluminal sources. After examining the basic synchro-Compton theory of ideal sources, applications of the theory to real sources is discussed. It is concluded that the Compton problem and total energy requirements are not substantially mitigated by considering source structures more complicated than the multiple, uniform-component model used by most investigators. Also, alternatives to the standard model of superluminal motion are discussed, focusing on the assumptions usually made when interpreting superluminal sources.

  19. Waste tank deflagration source generation mechanisms

    SciTech Connect

    Paddleford, D.F.; Thomas, J.K.

    1995-07-01

    This paper describes the models employed and analyses performed to estimate the source terms which would result from deflagrations in waste storage and processing tanks at the Savannah River Site (SRS). It should be noted that SRS waste tank deflagrations are very low probability events. The three main source generation mechanisms associated with waste tank deflagrations are: (1) entrainment from the liquid surface, (2) vaporization from the liquid surface, and (3) solids fire ignited as a result of the deflagration. The results of this work show that entrainment would be the dominant source term generation mode for cases where the liquid waste solution level is near the vent path. Vaporization would be the dominant mode for cases where the liquid level is lower. The maximum vaporization source term is approximately an order of magnitude less than that maximum entrainment source term. The source term associated with a solids fire would be insignificant in comparison.

  20. A compact, coherent light source system architecture

    NASA Astrophysics Data System (ADS)

    Biedron, S. G.; Dattoli, G.; DiPalma, E.; Einstein, J.; Milton, S. V.; Petrillo, V.; Rau, J. V.; Sabia, E.; Spassovsky, I. P.; van der Slot, P. J. M.

    2016-09-01

    Our team has been examining several architectures for short-wavelength, coherent light sources. We are presently exploring the use and role of advanced, high-peak power lasers for both accelerating the electrons and generating a compact light source with the same laser. Our overall goal is to devise light sources that are more accessible by industry and in smaller laboratory settings. Although we cannot and do not want to compete directly with sources such as third-generation light sources or that of national-laboratory-based free-electron lasers, we have several interesting schemes that could bring useful and more coherent, short-wavelength light source to more researchers. Here, we present and discuss several results of recent simulations and our future steps for such dissemination.